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FIELD OF THE INVENTION
[0001] The present invention relates to the field of mission management systems of uninhabited air vehicles, and more particularly to a method and system for automatic flight envelope protection to reduce damage and mishap rates of such vehicles.
BACKGROUND OF THE INVENTION
[0002] Flight envelope protection is an extension of an aircraft guidance system that prevents the aircraft from exceeding its designed operating limits while in one of the aircraft's standard guidance modes. Modern flight envelope protection features offer automated or semi-automated safety features. In manned aircraft, flight envelope protection is accomplished by the pilot, together with automated systems, using visual, auditory, tactile warning aids, and pilot controls.
[0003] On-ground sensing, usually provided by squat switches, is used to prevent inadvertent activation of ground spoilers and engine reverse thrust. Stall protection systems are used to warn of stalls and prevent stalls from happening. Digital engine controls provide engine protections such as thrust controls and reverse thrust controls.
[0004] These features are designed for the protection of the vehicle and its passengers and are used to prevent the vehicle from exceeding its structural and aerodynamic limitations. Exceeding a vehicle's limitations may lead to damage or complete destruction of the vehicle, termed a mishap.
[0005] Hard protections prevent the pilot from exceeding the flight envelope. Soft protection systems incorporate soft limits that warn pilots of pending or actual envelope exceedance, but allow the pilot to override the limitations.
[0006] With uninhabited (unmanned) aircraft, protection must be achieved automatically without intervention from a ground controller or other outside agent. Existing flight envelope protection systems for manned aircraft alert the pilot, who then must assess the situation and determine what action to take. In the uninhabited aircraft, to achieve automatic flight envelope protection, the method and system must not only be capable of detecting the conditions for alerting, but also determine appropriate corrective actions. This requires sensor signal logic (to replace the pilot's biosensory cues), and control logic, which are capable of overriding other commands (e.g., waypoint navigation) to the aircraft guidance or navigation systems whenever the aircraft enters a guidance condition which is not maintainable.
[0007] Automatic flight envelope protection may be realized as additional software on an existing guidance and navigation processor, or as a separate mission management processor and/or additional sensors and mechanical actuation devices for the aircraft. The main benefit of such protection is to reduce damage and mishap rates of unmanned vehicles by providing designed-in prevention of unsafe or unstable speeds and attitudes from which the vehicle cannot recover.
[0008] Some manned aircraft have extensions of the navigation system for route planning purposes, or have the mission plan or flight plan data entered and stored before initiation of a mission. However, manned aircraft do not usually have onboard planning. Uninhabited aircraft either have groundbased control stations (which, among other things, might transmit preplanned mission data), or mission planning systems (normally on board) which control the execution of the aircraft's mission.
[0009] Presently available mission planning systems for generating guidance or navigation commands for a vehicle (whether it is a ground-based controller, preprogrammed operating sequence, or mission management system) may at times generate commands which the vehicle cannot safely execute. These subsystems are designed prior to flight, and typically use simplified, fleet-wide models of aircraft performance—hence they will occasionally issue commands that a particular vehicle cannot execute.
[0010] For efficiency reasons, users implement fleet-wide envelope protection protocols. These govern all types of vehicles within a fleet. However, certain vehicles require different commands to remain within their flight envelopes. Each vehicle type usually has its own flight envelope. In addition, under various unanticipated flight conditions, mission planning systems may produce completely erroneous outputs for short periods of time. If these commands are simply executed by the guidance, navigation, or control systems they often result in damage to the vehicle or a mishap.
[0011] Some proposed flight envelope protection systems utilize neural networks that have been trained from large sets of known input values. However, these systems cannot detect or respond properly to extreme flight conditions where neither simulated nor measured flight data are likely to be accurate.
[0012] Existing methods of flight envelope protection, which involve the addition or modification of logic hardware in the mission management, guidance and navigation systems, avionics, or primary flight control systems, are not yet fully developed for uninhabited air vehicles, are not sufficiently adaptable to conditions of actual flight, and do not incorporate an integrated systems approach that is capable of balancing vehicle safety with mission objectives under all circumstances. The prior art suffers from:
[0013] limitations and faults of the mission management system and the software which supports it;
[0014] lack of a consistent definition of the flight envelope;
[0015] not linking the flight envelope parameterization to the guidance modes of the system;
[0016] not detecting when the flight envelope is about to be exceeded;
[0017] inadequately defining a corrective action, due to dependence on the availability of input from a pilot; and,
[0018] poor integration with existing mission management, guidance navigation, and flight control systems.
SUMMARY OF THE INVENTION
[0019] Automatic Flight Envelope Protection (AFEP) is embodied in software and computational hardware which augments existing guidance, navigation and/or control systems of Uninhabited Air Vehicles (UAV's) (also termed Unmanned, or Autonomous Air Vehicles). These include but are not limited to Cruise missiles, Unmanned Reconnaissance Vehicles (URV's), or Remotely Piloted Vehicles (RPV's). The invention automatically prevents UAV's from flying outside of their safe operating limits when they are subject to guidance commands generated by on-board mission planning systems or ground-based control systems.
[0020] The embodiments of the invention involve means of defining the flight envelope that are specifically suited to UAV's, means of anticipating and detecting actual or expected exceedance of the flight envelope and means of generating corrective actions which maintain the vehicle within the envelope, while maintaining vehicle controllability and awareness of UAV mission objectives. In addition, this invention includes new means of integrating these features into a system which is interoperable with conventional aircraft guidance, navigation, control, propulsion, and avionic subsystems.
[0021] The invention is a novel mission execution system that is capable of dynamically switching between levels: mission planner/navigation/guidance/flight control. The approach is “memory-less” in that it detects and corrects problems with immediate operating conditions and guidance commands, but relies on existing “memory” of the status of other subsystems (guidance, flight control) to store state information about the system.
[0022] The flight envelope protection algorithms are the lowest level of the vehicle management system, and their corrective actions are inserted between the navigation system 20 and the guidance or flight control system 30 . When the current operating point of the aircraft approaches the flight envelope too closely, or from the wrong direction, corrective actions will override or modify the navigation system inputs to the guidance system or the normal guidance system 20 inputs to the primary flight control system 30 . The invention retains intact the primary flight control functions, which are usually already designed for safety in the event of equipment failures (but not for other types of mishap prevention).
[0023] The AFEP algorithms accept inputs from air data to determine the current operating point within the flight envelope, from the guidance system 20 primarily the guidance mode and heading command, and from the mission planning system 40 to determine corrective actions which are most compatible with mission parameters, viz., tactical objectives. The flight envelope and current operating point are updated dynamically based on current air and vehicle data.
[0024] The algorithms dynamically determine the most critical distance of the current operating point from the boundary of the flight envelope, and the normal (approach) component of speed, and then compute corrective actions consistent with these parameters. This is preferably done by a “bounding polytope” method.
[0025] The algorithms use the “virtual actuator” (Aerodynamic Control Effector, or ACE) concept to allocate force among available physical actuators. The invention also uses aerodynamic control effectors to simplify the choice of actuators to implement control actions. The advantage of this approach is that ACE systems automatically adopt effective actuator forces and operative limits in the event of equipment failure or battle damage, so that no additional changes are required in the AFEP system. In the event that an ACE system is not available, the AFEP system can be designed to operate with a fixed set of physical actuators.
[0026] The AFEP algorithm contains hybrid logic that selects the corrective action based on the guidance mode of the aircraft, if any.
[0027] AFEP is intended to reduce damage and mishap rates of such vehicles, particularly when they are subject to guidance commands that would otherwise cause the vehicle to become uncontrollable and/or to exceed other operating limits which would cause permanent damage or destruction to the vehicle or its components. The AFEP concept is typically executed onboard the aircraft rather than on the ground. A concomitant benefit is the improvement in mission success rates and UAV availability, since mission success normally requires vehicles to remain operational. Another benefit is to improve the safety of other (manned or unmanned) vehicles which must inter-operate with UAV's in commercial or military airspace.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] [0028]FIG. 1 is a logical representation of UAV Onboard Signal Processing, showing the addition of AFEP blocks.
[0029] [0029]FIG. 2 is a flow chart representing the processing steps within the AFEP block.
[0030] [0030]FIG. 3 is a functional chart representing the processing steps for flight envelope protection for UAVs.
DETAILED DESCRIPTION OF THE INVENTION
[0031] The invention is embodied in the mission management, guidance, navigation, control (GNC) and avionics systems architecture of the unmanned air vehicle. The relationship of the AFEP system to the other existing subsystems is shown in FIG. 1. The invention incorporates executable computer programs, and may also include a separate processor unit (CPU) upon which this code is executed, additional sensor interfaces, and/or interfaces to various aircraft subsystems.
[0032] In some embodiments, these elements might be implemented as separate hardware components or as extensions to existing computing, sensor, or vehicle control subsystems. Otherwise, FIG. 1 may be interpreted as a software process block diagram. How those elements are implemented depends on the particular vehicle. If the vehicle has an adaptable processing unit the invention need only extend its abilities, if the vehicle does not have adequate sensing devices, the invention would incorporate the required sensors. Regardless of how they are implemented, however, the interfaces in FIG. 1 are significant to the invention in the following sense:
[0033] (1) The AFEP unit 10 is logically interposed between the navigation and guidance system 20 and the flight control system 30 .
[0034] (2) The AFEP unit 10 receives inputs from the mission planner 40 , from the vehicle avionics subsystem 23 ; it may receive inputs from additional sensor or payload subsystems 27 .
[0035] (3) The AFEP unit 10 produces outputs to the flight control system 30 or override switch 21 and (if it is present) to the mission management system 40 .
[0036] In varying embodiments, these subsystems may be merged, or may be absent, or may be implemented via a ground data link and pilot-in-the-loop, without affecting the fundamental signal flow shown in FIG. 1.
[0037] The top-level logic of the flight envelope protection software is shown in FIG. 2. The steps in this logic are now described:
[0038] Next Mission Command 100
[0039] A waypoint or mission command is obtained from the mission management system 40 . Without AFEP, this command (possibly after some preliminary calculations) is fed directly to the navigation 20 and/or guidance 25 system to be executed. With AFEP, this command is pre-evaluated to determine whether it is within the flight envelope of the vehicle, and is overridden 21 by an achievable command from the AFEP system if this is not the case. This modification of the data path includes the fact that this system examines one command in advance of the command currently executed.
[0040] Interpolate Next Step 110
[0041] Normally, a mission level command will require path interpolation, which is often done partly or completely by the navigation system 20 . If not, then this function needs to be performed in the AFEP system; if so, then the AFEP system needs to obtain incremental waypoint outputs from the navigation system 20 .
[0042] Exceed Envelope Limits 120 (Decisions)
[0043] The next interpolated step is evaluated to determine whether it exceeds envelope limits. These limits may include the consideration of both vehicle and earth-centered coordinates, and generally require dynamic updates based on vehicle avionics sensor 23 inputs to the AFEP system 10 (as fact that the flight envelope corrections do not require modifications to the normal Flight Control System. In the present case, very short term errors are corrected by the action of the flight control system itself.
[0044] Measure Aircraft State 160
[0045] The aircraft state is measured to determine that the command is being executed as planned. This step is standard, and is often performed within the control system.
[0046] Mission Command Completed 170 (Decision)
[0047] The mission command is evaluated vs. plan to determine whether the plan is being executed correctly. If not, the envelope limiting cycle will be initiated once again.
[0048] The steps “exceed envelope limits”, “calculate corrected command”, and “measure aircraft state” are now described in greater detail.
[0049] Exceed Envelope Limits Logic
[0050] The concept of “flight envelope” is normally applied to situations where some subset of the generalized coordinates of the vehicle (normally, either position or momentum variables) are held at (quasi) static values, and one considers “points” in position momentum space which are operationally feasible. One can consider all possible constant settings of any subset of actuators 70 , and represent all (six) generalized position and (six) generalized momentum (or velocity) coordinates of the vehicle. Normally, a primary flight control system (PFCS) 30 loop is required for these flight conditions to be stable in the sense that the derivatives of some combination of position or momentum variables are constant; normally, the PFCS 30 itself has modes, and one can consider that these might be further employed. Aside from modifying dynamics, the effect of a PFCS 30 is to provide static (as well as dynamic) coupling of certain control variables, which has the effect of constraining the effective flight envelope, so that the new inputs to the PFCS 30 replace the original inputs to individual actuators 73 , 75 . This can be modeled as follows:
{dot over (x)} E =u E cos θ cos ψ+ v E (sin φ sin θ cos ψ−cos φ sin ψ)+ w E (cos φ sin θ cos ψ+sin φ cos ψ)
{dot over (y)} E =u E cos θ sin ψ+ v E (sin φ sin θ cos ψ+cos φ cos ψ)+ w E (cos φ sin θ sin ψ−sin φ cos ψ)
{dot over (z)} E =−u E sin θ+ v E sin φ cos θ+ w E cos φ cos θ
{dot over (φ)}= p +( q sin φ+ r cos φ)tan θ
{dot over (θ)}= q cos φ− r sin φ
{dot over (ψ)}=( q sin φ+ r cos φ) sec θ (1)
[0051] where for wind W,
u
E
=u+W
x
;v
E
=v+W
y
;w
E
=w+W
z
[0052] are the generalized position equations (1), and the generalized momentum equations (2) are:
X−mg sin θ= m ( {dot over (u)} E +qw E −rv E )
Y+mg cos θ sin φ= m ( {dot over (v)} E +ru E −pw E )
Z+mg cos θ cos φ= m ( {dot over (w)} E +pv E −qu E )
L=I x {dot over (p)}−I zx {dot over (r)}+qr ( I z −I y ) −I zx pq+qh′ z −rh′ y
M=I y {dot over (q)}+rp ( I x −I z ) +I zx ( p 2 +r 2 ) +h′ x −ph′ z
N=I z {dot over (r)}−I zx {dot over (p)}+pq ( I y −I x ) +I zx qr+ph′ y −qh′ x (2)
[0053] where h′=[h′ x , h′ y , h′ z ] are the components of the net rotor inertias relative to the body frame of the aircraft and are assumed to be constant or slowly varying with respect to time. In these equations [X, Y, Z] and [L, M, N] are the aerodynamic forces and moments which include the control forces and moments. The net result of the feedback laws in the form (3), where error and measurement noise terms have not been explicitly shown are:
{right arrow over (F)}=[X,Y,Z,L,M,N]′={right arrow over (F)} ( x E ,y E ,z E ,u E ,v E ,w E ,φ,θ,ψ,p,q,r,{overscore (u)},{overscore (v)},{overscore (w)},{overscore (p)},{overscore (q)},{overscore (r)} ) (3)
[0054] In this example, the commanded velocity and angular rates are shown by overbars (in other autopilot configurations, attitude and altitude may also be controlled). One expression of the flight envelope is obtained by setting the time derivatives in (1), (2), subject to (3), equal to zero. The flight envelope can be derived from the vector set of equations (4):
{right arrow over (G)}=[{dot over (u)} E ,{dot over (v)} E ,{dot over (w)} E ,{dot over (p)},{dot over (q)},{dot over (r)}]′= 0 (4)
[0055] by solving for the actual steady rates (u, v, w, p, q, r) in terms of the commanded velocity and angular rates, and then finding the envelope of all solutions of (u, v, w, p, q, r) as the commanded variables are varied (noting that at several extremes of the flight envelope, the actual steady rates will not be equal to the commanded steady rates due to nonlinearities in the aerodynamic terms, and due to the limits in the ranges of the commanded variables).
[0056] For every point on the flight envelope there exists at least one set of extreme PFCS inputs and/or modes which holds that point in steady flight. An alternative view is that if the vehicle is in steady flight at a particular point in the flight envelope, then an inversion of the dynamic map of the aircraft (with the PFCS in place, if appropriate) can be used to evaluate whether a commanded change in position or orientation is within the marginal control authority that is available at the current operating point. In other words, the inversion map shows the changes in controls required in order to achieve a commanded change in position or orientation. The commanded change is within the flight envelope if the changes in all controls are within their admissible ranges of motion (and/or motion rates).
[0057] The V-N envelope is normally derived by assuming that there is a longitudinal axis control system, and that the roll and yaw commands (and actual steady rates) are set to zero. It expresses the relationship of vertical force (m{dot over (w)} E ) and actual forward speed (u), as a function of the implicit variables commanded climb rate ({overscore (W)}) and forward speed ({overscore (u)}). The V-H envelope is also derived for the longitudinal axis control problem, but for the case of an altitude hold condition (commanded z E ). In this mode, the controller controls altitude (z) while holding altitude rate (w) to zero.
[0058] The online computation of an inverse mapping could be demanding, therefore an alternative embodiment, is as follows:
[0059] (a) An inner approximation of the flight envelope (in any number of dimensions, to any specified degree of accuracy) can be obtained as the intersection of half-spaces. Each half-space can be specified by a normal vector and distance from the origin of the envelope coordinates (5).
{right arrow over (n)} i ·{right arrow over (e)}≦d i ,∀i= 1 , . . . N (5)
[0060] where n i is the normal vector to the I-th face of the flight envelope, e is a vector from the origin to a test point in the plane of the flight envelope, and N is the number of faces of the flight envelope (with higher N providing greater accuracy); d i is the distance of the ith face of the approximating region from the origin in the coordinates of the flight envelope.
[0061] (b) The current operating point (which is estimated from air data and other onboard sensors) can be also represented as a vector. By taking the inner product of this vector with each of the normal vectors, and subtracting it from the distance of the envelope, one can tell from the set of signs of all of these quantities whether the operating point is inside or outside of the flight envelope, and in fact can determine the distance to the nearest face of the polytope approximation of the flight envelope, as well as which face it is on.
s i =sgn ( {right arrow over (n)} i ·{right arrow over (e)}−d i );δ i i =|{right arrow over (n)} i ·{right arrow over (e)}−d i | (6)
[0062] (c) The distance from the flight envelope and if appropriate, speed of motion of the operating point toward the nearest boundary can be used to determine to a first approximation whether corrective action is required.
[0063] Calculate Corrected Command Logic
[0064] (d) If corrective action is required, the duration, direction and magnitude of thrust required for envelope avoidance (e.g., within a specified time) can be calculated. Normally, the corrective thrust will be applied in a direction that is normal to the closest face of the flight envelope. Using the Aerodynamic Control Effector (“ACE”) concept, actuators can be chosen in such a way that the desired force can be applied. At this time, the mission management system 40 is notified that the flight envelope boundary is near to the operating point, so that re-planning may occur. The definition of the particular boundary also may include which face of the envelope is being approached.
[0065] (e) Constant offsets are applied to the inputs of the PFCS 30 for the desired period of time. Monitoring of the operating point continues according to (a)-(d). During this time, mission re-planning should occur, so that the envelope is avoided; alternatively, the mission management system 40 may issue an “override” command to disable the flight envelope protection algorithm if an excursion from the flight envelope is considered to be necessary for vehicle survival.
[0066] (f) Control offset action ceases when the operating point is again within safe distance of the flight envelope. This may occur due to the shift of the operating point from the correction applied in (e), from a change in the mission command, or due to vehicle or atmospheric changes. It is possible that the operating point will now exhibit “chattering” or “sliding” in the plane of the (nearest hyperplane inner approximation to the) flight envelope boundary; this is not an error, but should be expected under certain conditions. This sliding motion will continue until the operating point finds a (possibly local) minimum which is least inconsistent with the mission command inputs; in some cases, it is possible that a slowly osculating pattern of motion of the operating point on one or more hyperplanes just inside the flight envelope boundary will be encountered. These should be viewed as normal occurrences which are consistent with, and in fact, required by, the nature of the flight envelope protection problem. During this motion, the mission planning algorithm will be repeatedly notified of the proximity of the operating point to the boundary.
[0067] (g) When flight envelope protection action is no longer required, the offsets to the PFCS 30 are removed by deactivating the override logic 21 , and return to normal flight is automatic. The proposed flight envelope protection algorithm leaves the PFCS 30 inner loop algorithms and limit protections in place, and does not introduce any additional short term dynamics (e.g., delays or integral action) into the system. Therefore, the PFCS 30 continues to operate as designed throughout the flight envelope protection intervention. Since the magnitude of the offset actions is continuously “phased in” near the boundary, the PFCS 30 is not subjected to any large disturbances. Since an “inner” polytope approximation of the flight envelope is used, there remains a small amount of residual control authority available to the PFCS 30 as the boundary is approached; the ACE (equivalent effector) approach will automatically select the most effective combinations of control surfaces to achieve the boundary avoidance. Finally, if the vehicle slightly exceeds the flight envelope (e.g., due to a gust or transient dynamics), the flight envelope protection algorithm will continue to act in a consistent manner to return it to the nearest point inside the boundary.
[0068] [0068]FIG. 3 depicts the data flow of the processing steps for flight envelope protection. The AFEP 10 receives feedback states from a sensor signal system 35 , a mission management system 40 and a guidance and navigation system 24 and sometimes a payload system 27 . The AFEP 10 calculates, a control command signal from these feedback and command signal inputs to determine if the vehicle is approaching its flight envelope. Any control signals that fall outside the flight envelope are modified appropriately to fall within the flight envelope. All signals conforming to the flight envelope are transmitted to the primary flight control system 30 which executes the mission commands.
[0069] Accordingly, it should be readily appreciated that the method and system for automatic flight envelope protection to reduce damage and mishap rates of uninhabited vehicles of the present invention has many practical applications. This invention may be applied to unmanned vehicles, cruise missiles, and remotely piloted vehicles as well as other types of vehicles. Additionally, although the preferred embodiment has been illustrated and described, it will be obvious to those skilled in the art that various modifications can be made without departing from the spirit and scope of this invention. Such modifications are to be considered as included in the following claims unless the claims expressly recite differently. | The present invention is for a method and system for automatic flight envelope protection to reduce damage and mishap rates of vehicles. The method and system generally comprise receiving a mission command from a mission management system that contains a predetermined flight mission; evaluating whether executing the command will maintain the vehicle within a flight envelope; modifying the command to one when executed will maintain the vehicle within the flight envelope, if otherwise; replanning and updating the mission pursuant to the command; sending the command to a flight control center; measuring the vehicle's state to determine if the command was executed as planned, and finally obtaining a next mission command. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to, and is a Divisional of, U.S. patent application Ser. No. 13/162,038, filed on Jun. 16, 2011, now pending, which claims priority from Taiwan Patent Application No. 099140292, filed on Nov. 23, 2010, both of which are hereby incorporated by reference in their entirety.
[0002] Although incorporated by reference in its entirety, no arguments or 16 disclaimers made in the parent application apply to this divisional application.
[0003] Any disclaimer that may have occurred during the prosecution of the above-referenced application(s) is hereby expressly rescinded. Consequently, the Patent Office is asked to review the new set of claims in view of all of the prior art of record and any search that the Office deems appropriate.
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] The present invention relates to a compound used to prevent diseases caused by aquaporin deficiency, and the compound as shown in FIG. 1 is a 18β-glycyrrhetinic acid derivative. The concept of such compound includes any salts, solvates, or pharmacologically-functional derivatives of such compound.
[0006] 2. Description of the Prior Art
[0007] Aquaporins, also called AQPs, are small (˜30 kDa), integrated membrane proteins. Thus far, 13 aquaporins were discovered (AQP-0˜12), and are classified into three groups according to their functions: aquaporins in the first group are responsible for water transport and include AQP-0, 1, 2, 4, 5, 6, and 8 (Verkman, 2005).
[0008] The second group, aquaglyceroporin, includes AQP-3, 7, 9, and 10. In addition to water transport, aquaglyceroporins also transport small molecules, e.g. glycerin and urea, etc. (Verkman, 2005).
[0009] AQP-11 and 12 belong to the third group, superaquaporin (Krane and Goldstein, 2007), and their functions remain unclear.
[0010] It was evidenced that several different aquaporins are expressed in mammalian skin. For example, AQP-1 is expressed at cell plasma membranes in fetal and newborn dermis; AQP5, on the other hand, is expressed in human sweat glands; and AQP-7 is expressed in the adipocytes located in subcutaneous tissue. AQP-3 is the best understood aquaporin and was initially found at the basal membrane in the epidermis in rat skin. In humans, AQP-3 is mainly expressed at the basal membrane in the epidermis (Hara-Chikuma and Verkman, 2008). In addition, Cao et al. demonstrated that AQP-3 is also expressed in the fibroblasts (Cao et al., 2006). AQP-3 facilitates water and glycerol transport in skin. Hence, it is involved in stratum corneum hydration. Literature has indicated that mice lacking AQP-3 manifest reduced stratum corneum hydration, premature aging, and lack of skin elasticity. These mice also exhibit significantly impaired epidermal and stratum corneum hydration (Hara-Chikuma and Verkman, 2008).
[0011] Glycyrrhizin is one of the major compositions of Glycyrrhiza species, and according to previous literature, glycyrrhizin has anti-inflammatory, anti-viral, and anti-allergic effects; and can inhibit prostaglandin secretion from macrophages. Furthermore, glycyrrhetinic acid is a metabolite of glycyrrhizin and an aglycon monomer; it also exhibits the same function as glycyrrhizin. In clinical skin care, glycyrrhetinic acid was used as an herb to treat various skin diseases, e.g. Dermatitis, Eczema, Pruritus, and Cysts, etc. The skin is a very important first line of defense system for the human body and provides protection against pathogen invasion; and stratum corneum plays an important role in the formation of the effective permeability barrier. Stratum corneum hydration is closely related with skin health and its normal physiological functions. Other factors that are involved in skin health are environmental humidity, skin structure, and the concentration of natural moisturizing factors, etc.
[0012] Application of glycyrrhetinic acid in skin care has been widely reported, and previous studies have also demonstrated its bioactivity. The effects of glycyrrhetinic acid on the activity and function of AQP-3 (e.g. wound healing), however, has not yet been clarified.
[0013] Given the above, after years of painstaking research and taking the novel applications of said derivative of 18β-Glycyrrhetinic acid in medicine cosmetology and diseases caused by aquaporin deficiency into consideration, the inventor(s) have developed a compound which can be used to prevent diseases caused by aquaporin deficiency, and said compound is a derivative of 18β-Glycyrrhetinic acid which can promote AQP-3 expression and subsequently enhance the skin function.
SUMMARY OF THE INVENTION
[0014] The present invention features a compound which can be used to prevent diseases caused by aquaporin deficiency. Said compound, as shown in FIG. 1 , is a 18β-Glycyrrhetinic acid derivative, where R could be one of H, CH 3 , CH(CH 3 ) 2 , and CH 2 Ph.
[0015] In one aspect, the present invention provides a compound which can increase the expression of AQP in various cells. Subsequently, such a compound facilitates the transportation of water and glycerol between dermis and epidermis, increases skin moisture, and enhances the moisture retention capacity of the skin, so as to let the skin contain more moisture and be more viable.
[0016] In another aspect, said compound can facilitate migration and proliferation of the keratinocytes and fibroblasts. Consequently, the effect of improving the healing of wounded skins can be achieved.
[0017] In another aspect, the present invention provides a medicinal composition which can be used to prevent diseases caused by aquaporin deficiency. Such medicinal composition comprises an 18β-Glycyrrhetinic acid derivative as shown in FIG. 1 and pharmaceutically-acceptable carriers that include diluents, fillers, binders, disintegrating agents, or lubricants.
[0018] The following detailed description of the invention will be better understood when read in conjunction with the appended drawings. However, the invention is not limited to the preferred embodiments shown.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In the drawings:
[0020] FIG. 1 shows the source and structure of the 18β-glycyrrhetinic acid derivative, where R could be one of H, CH 3 , CH(CH 3 ) 2 , and CH 2 Ph.
[0021] FIG. 2 shows the correlation between the expression of AQP-3 in fibroblasts and the concentration of the 18β-glycyrrhetinic acid derivative.
[0022] FIG. 3 demonstrates the correlation between the proliferation of the fibroblasts, examined by the MTT assay, and the concentration of the 18β-glycyrrhetinic acid derivative.
[0023] FIG. 4 shows the correlation between the proliferation of the fibroblasts, examined by the Trypan blue exclusion assay, and the concentration of the 18β-glycyrrhetinic acid derivative.
[0024] FIG. 5 shows the microscopic examination results under different concentrations of 18β-glycyrrhetinic acid derivative-induced fibroblast proliferation.
[0025] FIG. 6 is the result of in vitro scratch Wound Healing assay and shows the correlation between the cell migration and the increase of time under different concentrations of the 18β-Glycyrrhetinic acid derivative.
[0026] FIG. 7 is the result of Electric Cell-Substrate Impedance Sensing (ECIS) and shows the correlation between the changes of the resistance, expressing the change of cell comparative density and the increase of time under different concentrations of the 18β-glycyrrhetinic acid derivative.
[0027] FIG. 8 shows the expression of AQP-3 in human keratinocytes increases with time under the treatment of 30 μM 18β-glycyrrhetinic acid derivative.
[0028] FIG. 9 shows the correlation between the expression of AQP-3 and different concentrations of the 18β-Glycyrrhetinic acid derivative in human keratinocytes.
[0029] FIG. 10 is the MTT assay results and shows the correlation between the concentration of the 18β-glycyrrhetinic acid derivative and human keratinocytes proliferation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0030] The present invention will now be described more specifically with reference to the following embodiments, which are provided for the purpose of demonstration rather than limitations.
Embodiment 1
Preparation of the 18β-Glycyrrhetinic Acid Derivative
[0031] 18β-glycyrrhetinic acid is a metabolite of glycyrrhizic acid (GL) and an aglycon monomer ( FIG. 1 ). Several animal studies have indicated that 18β-glycyrrhetinic acid exhibits an anti-inflammatory effect (Maitraie et al., 2009). The 18β-glycyrrhetinic acid derivative used in the present invention was obtained by using a glycyrrhizic acid as a backbone and modifying the functional group at the C3 position of such glycyrrhizic acid, which is shown in FIG. 1 . R in the 18β-glycyrrhetinic acid derivative could be one of H, CH 3 , CH(CH 3 ) 2 , and CH 2 Ph.
Embodiment 2
Experiments about the Effects of the 18β-Glycyrrhetinic Acid Derivative on the Expression of AQP-3
[0032] 1. Cell Culture
[0033] The research was operated by using human primary fibroblast and human keratinocyte line (HaCaT), both of which were isolated from human foreskin. The primary fibroblast and HaCaT were put in a Dulbecco's Modified Eagle Medium (DMEM) nutrient mixture that contains 10% fetal bovine serum (FBS) and 1% antibiotics. Put the nutrient mixture in a 75 T-flask. Then, put the T-flask in an incubator at 37° C. and with 5% CO2 for cell culture. When the growth of the cells reached 90% confluence, a cell subculture was performed.
[0034] 2. Primary Dermal Fibroblast Cell Culture
[0035] Place the foreskin, provided by Dr. Wu, Nan-Lin from the Mackay Memorial Hospital in Hsinchu, Taiwan, in a solution of DMEM and 5% gentamycin, and store the solution at 4° C. Separate the foreskin from the solution, and then wash the foreskin by using phosphate-buffer saline (PBS) once and 1% antibiotics once. Place the foreskin in a 6 cm or 10 cm culture tray that contains a HBSS broth. The subcutaneous fat of the foreskin was then removed from the foreskin, and the foreskin was then cut into a 0.5 cm to 0.5 cm square cube. The cut foreskin was placed in a centrifuge tube that contains 0.25% trypsin (GIBCO) and HBSS, and the tube was stored at 4° C. for 24 hours. Next day, place the cut foreskin in a culture tray. The skin was peeled off by two tweezers. The hypoderma in the hypodermis of the cut foreskin was transferred into another culture tray. The hypodermal cells in the hypoderma were removed by using tweezers. Then, cut the processed foreskin into several pieces, and put them in a solution of 0.04% trypsin at 37° C. for 5 minutes. And, add an equal volume of DMEM that contains 10% FBS into the trypsin solution. The small pieces that precipitated in the bottom of the tray were removed. Then, the cell solution was centrifuged at 1100 rpm for 5 minutes. After the centrifuging operation, remove the clean solution, and leave the cells that precipitated in the bottom of the centrifuge tube. Then, the cells were suspended in a broth. Next, diversify the cells. If there are more cells, then use a T-75 culture tray to plate the cells. If there are not a lot of cells, then use a T-25 culture tray. Finally, place the culture tray in an incubator at 37° C. and with 5% CO 2 . The broth was changed after 2 to 3 days. Then, a subculture was performed in the next step.
[0036] 3. Subculture of Dermal Fibroblasts and Human Keratinocytes
[0037] The cells were washed twice by PBS. Mix a 5 ml solution that contains 0.5% Trypsin-EDTA (GIBCO) with the washed cells, and place the solution in an incubator at 37° C. and with 5% CO2 for 5 minutes. Through the microscope, make sure that the cells were separated. Then, add a broth that contains FBS to neutralize the effects of trypsin. The mixture of the cell solution was centrifuged in a centrifuge tube at 1100 rpm for 5 minutes. After the centrifugation, the supernatant was removed. And, leave the cells that precipitated in the bottom of the centrifuge tube. Use a broth to diversify the cells, and implant the cells on a flask. Put the flask in an incubator at 37° C. and with 5% CO 2 . Then, the broth was changed after 2 to 3 days. After that, the broth was changed twice a week.
[0038] 4. Western Blot Assay
[0039] Protein electrophoresis and western blot assay were used to analyze the intracellular AQP-3. 5×10 5 cells were plated onto a 6-cm round culture tray. Add 2 ml DMEM-mixed broth that contains 10% FBS and 1% antibiotics in the culture tray. Place the culture tray in an incubator at 37° C. for 24 hours. After that, a pure DMEM broth that does not contain FBS was used to prohibit cell growth. After another 24 hours, add a mixed broth of 2 ml that contains 0.1% THF and a testing agent (the 18β-glycyrrhetinic acid derivative) of 3 μM, 10 μM, or 30 μM into the round culture tray that was later put in an incubator at 37° C. for 24 hours. After the treatment of the 18β-glycyrrhetinic acid derivative, the cells were transferred and collected on ice of 4° C. Each culture tray was washed twice through the PBS. The cells were dissolved in a radioimmunoprecipitation assay buffer (17 mM Tris-HCl, pH 7.4, 50 mM NaCl, 5 mM EDTA, 1 mM sodium fluoride, 1% Triton X-100, 1% sodium deoxycholate, 0.1% SDS, 1 mM sodium orthovanadate, 1 mM PMSF, and 1 μg/ml aprotinin and leupeptin, freshly prepared). Peel off the cells, and use ultrasonic to pulverize the cells. Then, the cell solution was centrifuged at 13,200 rpm for 10 minutes at 4° C. The supernatant was collected. Use the Pierce protein assay kit (Pierce, Rockford, Ill.) to measure the protein quantity. Use proteins of 20 μg to operate the electrophoresis of 10% SDS-polyacrylamide gel. Then, use a PVDF membrane to perform electroblot. After the electroblot, put the PVDF membranes into a TBS-T (Tris-buffered saline and 0.05% Tween 20) solution that contains 0.5% skim milk. Shake the container of the TBS-T solution for 1 hour to prevent non-specific binding. After that, the membranes were then washed three times by the TBS-T. And, each time took 10 minutes. Next, add primary antibodies (1:500 dilutions) into the membranes, and store the membranes at 4° C. overnight. After that, the membranes were washed three times by the TBS-T, and each time took 10 minutes. Then, add secondary antibodies into the membranes. Wait for 1 hour. Then, wash the membranes through the TBS-T three times, and each time took 10 minutes. Finally, add a developing agent so as to print an image in a film in the dark room.
[0040] Recently, numerous studies have discussed the physiology of AQP-3 and wound healing, and the related molecular mechanisms. Hara Mariko et al. have reported that wound healing process was delayed in AQP-3 knockout mice; and Cong Cao has explored the effects of epidermal growth factor (EGF) on AQP-3 and wound healing. Cong Cao et al. have discovered, from the results of in vitro scratch wound healing assay, that expression of AQP-3 is significantly increased in EGF-treated groups, and wound healing was facilitated when treated with EGF. In summary, increasing the expression of AQP-3 is advantageous for skin wound healing. Therefore, the inventor(s) of the present invention further examined the correlation between the 18β-glycyrrhetinic acid derivative and human fibroblasts to see whether the 18β-glycyrrhetinic acid derivative can enhance the expression of AQP-3 in fibroblasts. The inventor(s) treated the fibroblasts by using an 18β-glycyrrhetinic acid derivative solution of 3 μM, 10 μM, or 30 μM. A tetrahydrofuran (THF) solution, which is used to treat 18β-glycyrrhetinic acid, was used as a control group. The western blot assay was applied for testing. According to the results of the testing, the treatment of 3 μM 18β-glycyrrhetinic acid derivative has no significant effects on AQP-3 expression, whereas the treatment of 10 μM or 30 μM 18β-glycyrrhetinic acid derivative can notably upregulate the expression of AQP-3. As shown in FIG. 2 , 18β-glycyrrhetinic acid derivative can increase the AQP-3 concentration in fibroblasts up to 15-45%.
Embodiment 3
The Effects of 18β-Glycyrrhetinic Acid on Fibroblast Proliferation
[0041] Cell Proliferation Assay
[0042] 1. MTT Assay
[0043] The cells were plated onto a 24-well culture plate, and each well evenly had the same concentration that is 3×10 4 cells per well. Add a 500 μl DMEM-mixed broth that contains 10% FBS and 1% antibiotics. Place the broth in an incubator at 37° C. for 24 hours. When the growth of the cells reached 70-80% confluence, the cells were then washed twice through the PBS. After that, use a pure DMEM solution, which does not contain FBS, to stop the cell growth. Then, after 24 hours, the cells were washed twice through the PBS. Then, add into the 24-well culture plate a 300 μl solution that contains a broth of 0.1% THF or an 18β-glycyrrhetinic acid derivative-mixed broth of 3 μM, 10 μM, or 30 μM. Place the plate in an incubator at 37° C. for 24 hours. After that, take a picture of the sample for observing the situation of cell proliferation. Next, add into each well of the plate a 300 μl solution of MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium]. After 2 to 4 hours, cell proliferation was examined by measuring the light absorbability through an ELISA reader operated at a wave length of 550 nm
[0044] 2. Trypan Blue Exclusion Assay
[0045] 5×10 5 cells were plated onto a 6-cm round culture tray. Add a 2 ml DMEM-mixed broth that contains 10% FBS and 1% antibiotics. Place the tray into an incubator at 37° C. for 24 hours. Wait for the cell growth to reach 70-80% confluence. The cells were then washed twice through the PBS. Use a pure DMEM broth that does not contain FBS to stop the cell growth. After 24 hours, the cells were washed twice through the PBS. Then, add into the 6-cm round culture tray a 2 ml broth that contains 0.1% THF, or a 2 ml 18β-glycyrrhetinic acid derivative-mixed broth that contains 18β-glycyrrhetinic acid derivative of 3 μM, 10 μM, or 30 μM. Place the tray in an incubator at 37° C. for 24 hours. Then, add into the tray a 2 ml solution of 0.5% Trypsin-EDTA. Place the tray in an incubator at 37° C. and with 5% CO 2 for 3-5 min. Use a microscope to see whether the cells are dissociated. After the cells were separated, a broth that contains FBS was added to the tray to neutralize the effects caused by Trypsin. Next, the cell-mixed solution was centrifuged in a centrifuge tube at 1,100 rpm for 5 minutes. After the centrifugation, remove the supernatant and leave the cells that precipitated in the tube bottom. Finally, use a broth to diversify the cells. Then, use a cell counter to count the number of cells in each sample.
[0046] Hara Mariko et al. proposed a theory in their study that upregulation of the AQP-3 expression can facilitate glycerol transport and promote cell proliferation. After it was evidenced that 18β-glycyrrhetinic acid derivative can significantly increase AQP-3 expression, we further tested whether 18β-glycyrrhetinic acid derivative can promote fibroblast proliferation. The effect of 18β-glycyrrhetinic acid derivative on fibroblast was examined using MTT assay. Our results showed that 18β-glycyrrhetinic acid derivative can notably induce fibroblast proliferation at the concentrations of 10 μM and 30 μM ( FIG. 3 ), and that total cell number can increase up to 25˜85%.
[0047] The principle of the MTT assay is measuring the activity of the reductase, which cuts the tetrazolium ring and reduces the yellow MTT dye in solution to insoluble purple formazan. The absorbance of the colored solution can be used to measure relative cell concentration. In order to prevent experimental errors resulted from reduced reductase activity which was caused by 18β-glycyrrhetinic acid derivative, another cell proliferation assay was used to cross examine the cell proliferation: Trypan blue exclusion assay. According to the results ( FIG. 4 ), treatments of 10 μM and 30 μM 18β-glycyrrhetinic acid derivative indeed promote cell proliferation.
[0048] As shown in FIG. 5 , fibroblast proliferation was also observed under a light microscope. Treatment groups of 10 μM and 30 μM 18β-glycyrrhetinic acid derivative have significantly more cells than untreated control groups. Given the results of FIG. 3 , FIG. 4 , and FIG. 5 , 18β-glycyrrhetinic acid derivative at both 10 μM and 30 μM concentrations can promote fibroblast proliferation up to 25-85%.
Embodiment 4
The Effects of 18β-Glycyrrhetinic Acid on Migration of Fibroblasts
[0049] Cell Migration Assay
[0050] 1. In Vitro Scratch Wound Healing Assay
[0051] 5×10 5 cells were plated into a 6-cm round culture tray. Add into the tray a 2 ml DMEM-mixed broth that contains 10% FBS and 1% antibiotics. Place the tray in an incubator at 37° C. for 24 hours. After that, replace the used broth with a pure DMEM broth that contains no FBS to stop the cell growth. After 24 hours, use a 200 μl tip to scratch the tray inside the tray. The scratch was considered a wound. Then, add into the tray a 2 ml broth that contains 0.1% THF, or a 2 ml 18β-glycyrrhetinic acid derivative-mixed broth that contains 18β-glycyrrhetinic acid derivative of 3 μM, 10 μM, or 30 μM. Place the tray in an incubator at 37° C. Take a picture of the wound-healing progress at the 0 hour, 6th hour, 12th hour, and 24th hour.
[0052] 2. Electric Cell-Substrate Impedance Sensing (ECIS)
[0053] ECIS was used to examine the wound healing progress. Plate 7×10 4 cells in an ECIS-specific culture tray. Add into the tray a 400 μl DMEM-mixed broth that contains 10% FBS and 1% antibiotics. Place the tray in an incubator at 37° C. for 24 hours (the culture tray was wetted for 1 hour before the incubation). Then, use an apparatus to examine the growth and homogeneity of the cells that were prepared the night before. After the cells become stable for a period of time (two hours), perform electric shock over the cells to damage them. Then, add into the tray a 400 μl broth that contains 0.1% THF, or a 400 μl 18β-glycyrrhetinic acid derivative-mixed broth that contains 18β-glycyrrhetinic acid derivative of 3 μM, 10 μM, or 30 μM. Place the tray in an incubator at 37° C. During the incubation, the impedance was monitored in real-time and recorded.
[0054] 3. Statistics
[0055] Sigma-plot software was used to calculate mean±standard error (SE) as a representative value. An unpaired, two-tailed Student's t test was used for statistics, and p value less than 0.05 was considered significantly different, with an asterisk (*) as a note.
[0056] In their cell proliferation experiments, Hara Mariko et al. proposed a theory that upregulation of the AQP-3 expression can facilitate glycerol transport and promote cell proliferation. Meanwhile, the idea that activation of AQP-3 expression can facilitate water transport and enhance cell migration was also discussed. Hence, we examined cell migration by in vitro scratch wound healing assay. After the treatment with 3 μM, 10 μM, or 30 μM 18β-glycyrrhetinic acid derivative, under a microscope, cell migration was photographed at the 6th hour, 12th hour and 24th hour. Our results ( FIG. 6 ) indicated that in the 6th-hour post-treatment, no cell migration of fibroblast was observed in either experimental or control groups. However, in the 12th-hour post-treatment, the cells in 10 μM and 30 μM 18β-glycyrrhetinic acid derivative treated groups begin to migrate toward the scratched wound. In the 24th-hour post-treatment, significant cell migration toward the scratched wound was observed in both groups, which suggested that 18β-glycyrrhetinic acid derivative can promote cell migration.
[0057] Following in vitro scratch Wound Healing assay, we further verified cell migration by using electric cell substrate impedance sensing (ECIS). ECIS measures the change in impedance of a small electrode to AC current flow. The resistance (impedance) positively correlates with cell densities. ECIS is different from scratch assay in that in ECIS, cells grow on the electrodes, and current flow damages the cells and cell density can be monitored in real time. Following treatments of 18β-glycyrrhetinic acid derivative, the impedance of 10 μM and 30 μM started and continued to increase, which suggested that the wound heals more rapidly ( FIG. 7 ); and from the results of FIG. 6 and FIG. 7 , 18β-glycyrrhetinic acid derivative can promote fibroblast cell migration.
[0058] HaCaT (Human Keratinocytes Cell Line)
(1) Examination of the effects of 18β-glycyrrhetinic acid derivative on AQP-3 expression
[0060] Following examination the activity and effects of 18β-glycyrrhetinic acid derivative on human fibroblast, we further tested the effects of 18β-Glycyrrhetinic acid derivative on AQP-3 in human keratinocytes. First, the cells that were treated with 30 μM 18β-glycyrrhetinic acid derivative were used as the experimental group, and the control group was treated with THF, the solvent for 18β-glycyrrhetinic acid derivative. The cells, which were collected in the 6th-hour, 12th-hour, and 24th-hour post-treatments, were analyzed by the western blot. According to the results, AQP-3 expression shows no significant increase at the 6th-hour and 12th-hour post-treatments. Yet, at the 24th-hour post-treatment, the increased expression of AQP-3 was observed, and reached the peak at the 48th-hour post-treatment. Subsequently, we examined the effects of various concentrations of 18β-glycyrrhetinic acid derivative on AQP-3. As demonstrated in our results, AQP-3 expression in human keratinocytes increased accordingly with increased concentrations of 18β-glycyrrhetinic acid derivative ( FIG. 9 ).
[0061] Given the above, 18β-glycyrrhetinic acid derivative can indeed increase AQP-3 expression in human keratinocytes up to 45-65%.
(2) The effects of 18β-glycyrrhetinic acid derivative on cell proliferation in human keratinocytes.
[0063] After it was demonstrated that 18β-glycyrrhetinic acid derivative can significantly increase AQP-3 expression in human keratinocytes, we also explored whether 18β-glycyrrhetinic acid derivative can promote cell proliferation. MTT assay was used to examine the effects of 18β-glycyrrhetinic acid derivative on human keratinocyte proliferation. The results indicated that 18β-glycyrrhetinic acid derivative, at the concentrations of 10 μM and 30 μM, can notably promote cell proliferation ( FIG. 10 ), and human keratinocytes increased around 15˜45%.
[0064] The foregoing detailed descriptions are practical examples of the present invention. It should be noted, however, that such examples are provided for the purposes for demonstration rather than limitation. Applications of said compound in medicinal cosmetology are all included in the present invention. Many changes and modifications in the above described embodiments of the invention can, evidently, be carried out without departing from the scope thereof. Accordingly, to promote the progress in science and the useful arts, the invention is disclosed and is intended to be limited only by the scope of the appended claims. | A compound used to prevent diseases caused by aquaporin deficiency, which is 18β-Glycyrrhetinic acid derivative. Said compound can not only prevent diseases caused aquaporin deficiency, but be able to prevent aquaporin (AQP) production and enhance skin function. Since AQPs have many advantages in skin cells, e.g. promoting water and glycerine molecular transportation, increasing skin elasticity and cuticle moisture, increasing the cell proliferation and cell migration, aquaporin can promote skin bather function and wound cicatrization. Therefore, said compound can be applied potentially as a medicinal cosmetic in skin medicine cosmetology, or as a new medical composition to treat diseases caused by AQP abnormality, such as urine concentration defect, wound healing slow down, corneal re-epithelialization slow down and etc. | 2 |
FIELD OF THE INVENTION
This invention relates to dressers that can be converted into dressing tables. The invention is more particularly concerned with dressers having a flippable top surface that can be converted into a dressing table for infants.
BACKGROUND AND SUMMARY OF THE INVENTION
The usefulness of furniture such as dressers, cabinets, or bureaus can be greatly increased by providing a hinged or otherwise attached top which can be configured to provide greater working space or allow access to interior regions of the cabinet. For example, both U.S. Pat. No. 1,369,577 to Townley and U.S. Pat. No. 3,703,324 to Smith describe furniture having hinged tops that open to provide an increased working surface. Townley '577 describes a kitchen cabinet having a hinged top which can be opened to provide increased working space but when closed presents the appearance of a standard cabinet. Smith '324 discloses a cabinet having a top surface that is hingeably mounted to form either a flat dressing table for infants or alternatively to form a recessed shelf with side and top panels.
Both the cabinets described by Townley '577 and Smith '324 have an inherent disadvantage associated with the required cost and additional labor needed to add hinges to the cabinets to swingably support the top panel in an opened position.
It is therefore an object of the present invention to provide a dressing table that can be interchangeably converted into a cabinet.
It is another object of this invention to provide a convertible dresser having a front cabinet door and a flippable board configured to form a cabinet top so that the cabinet can be converted into a dressing table by rotating the front cabinet door into a horizontal position and reversing the orientation of the flippable board to bring flippable board into a horizontal position adjacent to the front cabinet door, forming an extensive level surface for use as a dressing table.
Yet another object of this invention is to provide a convertible dresser having a cabinet with front, back, and side panels, a front cabinet door with an upper portion curved toward the back panel of the cabinet, and a flippable board configured to form a cabinet top so that the cabinet can be converted into a dressing table by rotating the front cabinet door into a horizontal position and reversing the orientation of the flippable board to bring flippable board into a horizontal position adjacent to the front cabinet door, forming an extensive level surface surrounded in part by the back panel, side panels, and curved upper portion of the front cabinet door.
In accordance with the previous objectives, the present invention is a cabinet that can be converted into a dressing table. The cabinet has a cabinet body having first and second side panels that are interconnected in a spaced apart relationship. A front cabinet door is attached to the first and second side panels for swinging movement therebetween. The cabinet also includes a flippable board having a first and second surface that rests upon the cabinet body. The flippable board has first and second supports attached to the first surface and arranged in spaced apart relationship so that the flippable board is capable of assuming two orientations with respect to the cabinet body, respectively oriented in a first arrangement with the second surface of the flippable board positioned to form a cabinet top of the cabinet body and in a second orientation with the first surface positioned in a coplanar, adjacent relationship with the front cabinet door placed in an extended position to project horizontally outward from the first and second side panels.
In preferred embodiments the cabinet body is formed by first and second side panels vertically arranged in parallel spaced apart relationship and connected together with a back panel. In the cavity of the cabinet body defined by the conjunction of the first and second side panels and the back panel are positioned a plurality of drawers that are slidably movable in a horizontal plane outward from the back panel to extend from the cabinet body. A top support board is positioned above the plurality of drawers in a horizontal plane extending between the first and second side panels and the back panel to constitute an uppermost horizontal surface. In preferred embodiments the top support board is situated between the first and second side panels and the back panel so that the side and back panels continue to extend upward from the site of horizontally arranged attachment of the top support board.
The flippable board can be placed to rest upon the top support board in two differing orientations. In one orientation the flippable board is positioned so that it is supported by first and second supports to define a space between the first surface of the flippable board and the top support board. In a second orientation, the flippable board is positioned to rest upon the top support board so that a flat surface suitable for a dressing table is provided.
A useful feature of the present invention is the lack of hinge elements or actively movable support members necessary for converting the dresser into a dressing table. Converting from a configuration suitable for a dresser with a top to a dressing table only requires that the flippable board be inverted so that the flippable board is in direct contact with the top support board. Similarly, converting from a dressing table into a dresser involves reversing the procedure, inverting the flippable board so that it is supported by first and second supports which create a storage space between the flippable board and the top support board.
Yet another advantage of the present invention is realized by the increased area of dressing table made available by extending the front cabinet door. The front cabinet door can be swung forward by rotation about pins that attach the front cabinet door between the first and second side panels. The forward rotation of the front cabinet door forward is blocked in a horizontal position by the action of blocks set on the first and second side panels so that a substantially flat surface located adjacent and coplanar to the flippable board is created. The combination of the properly oriented flippable board and front cabinet door together form a substantially flat surface suitable for use as a dressing table.
Still another advantage of the present invention results from the positioning of the top support board at a predetermined distance below the upper edges of the front, side and back panels. When the flippable board is oriented to act as a dressing table, the predetermined distance of first and second side panels and back panel act as a barrier to better contain the movements of infants or objects placed upon the dressing table. This advantage is also promoted by providing the front cabinet door with an curved portion that upwardly extends in a generally vertical manner when the remaining flat portion of the front cabinet door is in an extended horizontal position.
Additional features and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of a preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived. The detailed description particularly refers to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a dresser that can be converted into a dressing table.
FIG. 2 is a perspective view of a flippable board oriented in a position suitable for defining a storage space when placed to rest upon a cabinet body.
FIG. 3 is a schematic side view broken away to illustrate a front cabinet door in an extended position to form in conjunction with the flippable board a dressing table.
FIG. 4 is a side section illustrating the front cabinet door in a closed position and the flippable board oriented to define a storage space when placed to rest upon the cabinet body.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A convertible dresser 10 in accordance with the present invention is illustrated in whole or in part in FIGS. 1 through 4. The convertible dresser 10 includes a cabinet body 11 formed from a first side panel 12 and a second side panel 14. The first and second side panels 12 and 14 are arranged vertically arranged in a parallel spaced apart relationship. They are connected by a back panel 16 that is vertically arranged in perpendicular attachment to both the first and second side panels 12 and 14.
Disposed between the side panels 12 and 14 are a plurality of drawers 18. Each drawer 18 can be extended outward from the cabinet body 11 to allow access to the interior space (not shown) of the drawers 18. Also situated between the first and second side panels 12 and 14 is a top support board 20. The top support board 20 is arranged to horizontally lie between the first and second side panels 12 and 14.
Resting atop the top support board 20 is a flippable board 22. The flippable board 22 has a first surface 23 and a second surface 24. Attached perpendicularly to the first surface 23 are a first support 25 and a second support 26. The first and second supports 25 and 26 are arranged in parallel spaced apart relationship with respect to each other.
The convertible dresser 10 is shown in FIGS. 1 and 3 with the flippable board 22 oriented so that the second surface 24 contacts and supports the flippable board 22. In this configuration, the complex between the cabinet body 11 and the flippable board 22 forms a dressing table suitable for use with infants. If desired, the orientation of the flippable board 22 can be reversed, so that the first and second support rest upon the top support board 20 of the cabinet body 11, as shown in FIGS. 2 and 4. A storage space (not shown) is defined in part by the first surface 23, the top support board 20, and the first and second supports 25 and 26 of flippable board 22 when the flippable board 22 is oriented in this manner.
The usefulness of the convertible dresser 10 is further augmented by providing the cabinet body 11 with a front cabinet door 28 as shown in FIG. 1 and FIGS. 3 and 4. The front cabinet door 28 can be configured to either extend the horizontal surface suitable for use as as a dressing table, such as shown in FIG. 1 and 3, or can be used to cover the storage space defined by the flippable board 22 and the top board 20, as shown in FIG. 4.
The front cabinet door 28 has a flat portion 30 and a curved portion 32. The front cabinet door 28 is swingably mounted between the first and second side panels 12 and 14 using pins 40 that permit the front cabinet door to swing forward from a substantially vertical position into a horizontal position with the flat portion 30 lying coplanar to flippable board 22. The forward swinging action of the front cabinet door is halted with the aid of blocks 34 attached to the first and second side panels 12 and 14.
When the flippable board 22 is oriented to define a storage sPace, the front cabinet door 28 act to provide a moveable cover for that storage space. The front cabinet door 22 can be swung forward to permit access to that storage space, or can be closed as shown in FIGS. 3 and 4 to block access to the storage space. In operation, closure of the front cabinet door 28 involves swinging the front cabinet door 28 forward until forward motion is halted by stops 36 attached to the first and second side panels 28. In the embodiment illustrated, the stops 36 are positioned so that the front cabinet door 28 is oriented in a substantially vertical position. | A front cabinet door, attached to the first and second side panels for swinging movement therebetween, so that said front cabinet door can assume an open position with a substantially horizontal orientation parallel to the flippable board and a closed position vertically oriented perpendicular to the flippable board. | 0 |
RELATED APPLICATIONS
The present application claims the priority benefit of Japanese Patent Application No. 2004-359224, filed on Dec. 10, 2004, which is hereby incorporated by reference in its entirety.
The present application hereby incorporates by reference the following copending United States Patent Applications: (1) application Ser. No. 11/301,282, filed on even date herewith, which is entitled STRADDLE-TYPE VEHICLE HAVING CLUTCH CONTROL DEVICE AND METHOD OF USING CLUTCH CONTROL DEVICE and which has; (2) application Ser. No. 11/301,646, filed on even date herewith, which is entitled CLUTCH ACTUATOR FOR STRADDLE-TYPE VEHICLE and; which has; (3) application Ser. No. 11/299,720, filed on even date herewith, which is entitled APPARATUS AND METHOD FOR CONTROLLING TRANSMISSION OF STRADDLE-TYPE VEHICLE and which has; and (4) application Ser. No. 11/299,858, filed on even date herewith, which is entitled GEAR CHANGE CONTROL DEVICE AND METHOD and which has. The contents of all of the above-noted copending U.S. patent applications are hereby incorporated by reference in their entireties.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a device and method that control the engagement speed of a clutch. More particularly, the present invention relates to such a device and method as they are employed on a straddle-type vehicle.
2. Description of the Related Art
Vehicles can have any of a number of different transmission types. Three types of shiftable transmissions are a manual transmission, a semi-automatic transmission in which clutch manipulation by a rider is not required for shifting and an automatic transmission. These types of transmissions generally comprise a clutch.
As is known, a clutch generally is used to interrupt the flow of power from an engine output to a transmission input. As such, the clutch typically comprises a drive member on the engine side and a driven member on the output side. When the driven member and the drive member are brought together, the clutch is considered engaged. When the driven member and the drive member are separated, the clutch is considered disengaged. The clutch typically is engaged and disengaged with an engagement device that uses a clutch actuator to bring the drive member and the driven member into engagement.
Some clutch engagement devices feature two or three different speeds at which the clutch is engaged in order to improve the feel of the engagement action while shortening the time for engagement to occur. For example, if the clutch is moving from a disengaged state to a semi-engaged state, engagement may occur rapidly by forcing the drive side and the driven side of the clutch together at a high speed. Once the clutch has become semi-engaged, the clutch engagement proceeds at a low speed from semi-engagement to engagement until a clutch rotating speed difference becomes less than or equal to a predetermined value. The low speed movement from the semi-engaged state to the engaged state reduces an impact between the drive side and the driven side, which reduction results in a more comfortable operation for the rider.
To shorten the time required to achieve engagement, some clutches, once semi-engaged, continue to bring the drive-side and the driven-side together at a high speed once a clutch rotating speed difference becomes less than or equal to the predetermined value. Such configurations can be found, for instance, in JP-A-2001-146930 and JP-A-2001-173685.
While such constructions bring the drive member and the driven member together at different speeds during the range of movement, these speeds do not vary based upon the difference in rotational speeds of the drive member and the driven member (i.e., a clutch rotating speed difference). For instance, while the clutch rotating speed difference gradually varies over time during engagement of the clutch, two or three preset clutch engagement speeds are maintained until a clutch rotating speed difference becomes less than or equal to a predetermined value without adjusting the clutch engagement speed according to the difference in the rotational speeds of the two members.
Therefore, conventional clutch connection devices do not respond in different ways to different operational demands. The drive member and the driven member are brought together at the same two or three speeds regardless of the operating conditions. For example, quick braking and/or quick throttle operation of a vehicle by a rider while engaging the clutch is treated the same as an ordinary clutch engagement.
SUMMARY OF THE INVENTION
Accordingly, one aspect of the present invention involves a clutch connection control device for engagement and disengagement of a clutch. The engagement and disengagement are performed by a clutch actuator. The device comprises a clutch rotating speed difference detecting means that detects a difference in rotating speed between a drive side and a driven side of the clutch. The clutch engagement speed varying means varies a clutch engagement speed according to variation in the clutch rotating speed difference detected by the clutch rotating speed difference detecting means. The clutch connecting means causes the drive side and the driven side of the clutch to approach each other at the clutch engagement speed varied by the clutch engagement speed varying means.
Another aspect of the present invention involves a clutch engagement control method for engagement and disengagement of a clutch using a mechanical clutch actuator. The method comprises detecting a clutch rotating speed difference, which is a difference between a rotating speed of a drive side of the clutch and a rotating speed of a driven side of the clutch, varying a clutch engagement speed according to the detected clutch rotating speed difference, and moving the drive side and the driven side of the clutch toward each other at the varied clutch engagement speed.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, aspects and advantages of the present invention will now be described with reference to the drawings of a preferred embodiment, which embodiment is intended to illustrate and not to limit the invention, and in which figures:
FIG. 1 is a side view of a straddle-type vehicle that is arranged and configured in accordance with certain features, aspects and advantages of the present invention.
FIG. 2 is a schematic overview of a control system that comprises a control device arranged and configured in accordance with certain features, aspects and advantages of present invention.
FIG. 3 is a schematic view representing a sensor/switch group that can be connected to the control device of FIG. 2 .
FIG. 4 is a schematic view of a portion of a main microcomputer that can be used in embodiments arranged and configured in accordance with certain features, aspects and advantages of the present invention.
FIG. 5 is a graphical depiction of a second engagement motion starting clutch position map.
FIG. 6 is a graphical depiction of a second engagement speed map used during an up-shift in some embodiments.
FIG. 7 is a graphical depiction of a second engagement speed map used during a down-shift in some embodiments.
FIG. 8 is a time-based graphical depiction during an up-shift of a clutch position, a turning angle of a shift actuator, and a gear position at the time of up-shift.
FIG. 9 is a time-based graphical depiction during a down-shift of a clutch position, a turning angle of a shift actuator, and a gear position at the time of down-shift.
FIG. 10 is a control flowchart illustrating a clutch connection control device that is arranged and configured in accordance with certain features, aspects and advantages of the present invention.
FIG. 11 is a control flowchart illustrating a clutch connecting motion routine of FIG. 10 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to FIG. 1 , a straddle-type vehicle is illustrated that has been arranged and configured in accordance with certain features, aspects and advantages of the present invention. In the illustrated configuration, the straddle-type vehicle is a motorcycle 100 . In other configurations, the straddle-type vehicles can comprise, for example but without limitation, motorcycles, motorized bicycles, scooters, three-wheeled and four-wheeled buggies such as all terrain vehicles, snowmobiles and the like.
The illustrated motorcycle 100 comprises a front wheel 110 and a rear wheel 112 . A front fork 114 is connected to the front wheel 112 . A handle 116 extends laterally across the motorcycle 100 and is connected to a top of the front fork 114 . The handle 116 comprises a grip 102 and a clutch lever 104 that are mounted at a first end and an accelerator grip and a brake lever (not shown) that are mounted at a second end.
The motorcycle 100 comprises an engine 106 and a fuel tank 108 that is positioned generally vertically above the engine 106 . The motorcycle further comprises a seat 118 that is provided on an upper portion of the motorcycle 100 at a location rearward of the fuel tank 108 in the illustrated configuration. A rider can ride the motorcycle 100 while straddling the seat 118 .
With reference now to FIG. 2 , the motorcycle 100 comprises a control device 10 . The control device 10 preferably comprises a main microcomputer 1 . The main microcomputer 1 can have any suitable configuration. In other words, the main microcomputer 1 can be a specially designed component or can be a standard component that operates specially prepared programs or code to accomplish the features, aspects and advantages of the present invention that are desired in any particular application. Other suitable microprocessors and components can be used in place of or together with the microcomputer 1 .
The main microcomputer, in the illustrated configuration, receives input information from, among other components, a sensor/switch group 99 . With reference now to FIG. 3 , the illustrated sensor/switch group comprises an up-shift sensor 91 and a down-shift sensor 96 . As will be explained, the up-shift sensor 91 and the down-shift sensor 96 can be used to input requests from the rider to adjust the gearing of the transmission.
In addition, the sensor/switch group 99 comprises a gear position sensor 93 . The gear position sensor 93 inputs information to the main microcomputer 1 regarding whether the transmission is in gear and/or the gearing currently used by the transmission. The gear position sensor 93 can be mounted to the transmission. In some embodiments, the gear position sensor 93 can input into the main microcomputer 1 a voltage value corresponding to a turning angle of a shift cam shaft as gear position information. Other suitable configurations also can be used.
The sensor/switch group 99 also preferably comprises two sensors that can be used to determine a clutch rotating speed difference. As can be appreciated, when the clutch is disengaged or semi-engaged, the drive side of the clutch and the driven side of the clutch will be rotating at different speeds. In the illustrated embodiment, the main microcomputer receives input information from a first clutch rotating speed sensor (e.g., an engine-side clutch rotating speed sensor) 94 , which can be mounted to a member on an engine-side of the clutch. The main microcomputer 1 also receives input from a second clutch rotating speed sensor (e.g., a main-shaft/transmission side clutch rotating speed sensor) 95 , which can be mounted to a member on a main-shaft/transmission side of the clutch. The first clutch rotating speed sensor 94 preferably detects the rotating speed of a member on the engine-side of the clutch and the second clutch rotating speed sensor 95 preferably detects a rotating speed of a member on the main-shaft/transmission side of the clutch. A rotating speed of the member on the engine-side of the clutch also may be detected on the basis of, for example, the frequency emitted from a crank pulse sensor mounted to a crank of the engine. A rotating speed of the member on the main-shaft side of the clutch also may be detected by calculation based on a vehicle speed and a gear reduction ratio. Any other suitable configurations also can be used to detect either or both speeds. The detected speeds can be input into the main microcomputer 1 respectively as engine-side clutch rotating speed information and as transmission-side clutch rotating speed information. In some configurations, the detected speeds can be used to calculate the difference in speeds, which is then input into the main microcomputer 1 .
The illustrated sensor/switch group 99 further comprises a key switch 82 . The key switch 82 preferably utilizes a key of the motorcycle and is moved to the ON position by rotation of the key of the motorcycle. Other suitable configurations can be used.
While the above-identified sensors can be used, other sensors also can be used. In addition, while the illustrated sensors preferably directly detect the states of the associated components, the sensors also can comprise so-called pseudo sensors that indirectly detect the states of the components desired to be sensed.
With reference again to FIG. 2 , a battery is connected to the control device 10 . The battery 10 can supply power to the main microcomputer 1 . In the illustrated embodiment, the battery 10 supplies power to the main microcomputer 1 through a power circuit 85 . The power circuit 85 can transform the voltage of the battery 10 into a useable voltage for the main microcomputer 1 .
The power circuit 85 preferably comprises a switch (not shown) that is switched to an ON position when the key switch 82 is moved to the ON position. When the switch is moved to the ON position by actuation of the key switch 82 , a signal (e.g., a switch-ON signal) can be output to the main microcomputer 1 .
The power circuit 85 also preferably comprises a holding circuit 84 . The holding circuit 84 is adapted to briefly continue the supply of power from the battery 98 to the main microcomputer 1 following the key switch 82 being moved to the OFF position. In one configuration, when the key switch 82 is moved to the OFF position, the power circuit switch preferably is temporarily held in the ON position by the holding circuit 84 . The power circuit 84 therefore can continue to supply voltage to the main microcomputer 1 such that the main microcomputer can complete any desired shutdown operations. When the shutdown operations have been completed by the main microcomputer 1 , the supply of electric power to the main microcomputer 1 from the power circuit 85 ceases.
The illustrated control device 10 preferably uses the main microcomputer 1 to control operation of a clutch actuator 41 and operation of a shift actuator 51 . As shown in FIG. 4 , the main microcomputer 1 preferably comprises a clutch actuator control unit 11 and a shift actuator control unit 19 . Thus, the clutch actuator 41 and the shift actuator 51 can be controlled based upon information that indicates the operational state of the vehicle. In one configuration, the information can be input from the sensor/switch groups 99 , the clutch actuator 41 itself (i.e., a clutch potentiometer 44 ), and the shift actuator 51 itself (i.e., a shift potentiometer 54 ). The clutch actuator control unit 11 and the shift actuator control unit 19 output signals respectively to a clutch motor drive circuit 42 and a shift motor drive circuit 52 .
The clutch motor drive circuit 42 supplies electric power that drives a clutch actuator 41 . The illustrated control device also comprises a shift motor drive circuit 52 . The shift motor drive circuit 52 supplies electric power that drives a shift actuator 51 .
In one configuration, the clutch motor drive circuit 42 comprises a known H bridge circuit. The clutch motor drive circuit 42 feeds electric current from the battery 98 to a dc motor of the preferred clutch actuator 41 . The current is delivered to rotate the dc motor in the direction and at the speed corresponding to the clutch actuator drive signal supplied from the main microcomputer 1 .
Similarly, in one configuration, the shift motor drive circuit 52 comprises a known H bridge circuit. The shift motor drive circuit 52 feeds electric current from the battery 98 to a dc motor of the preferred shift actuator 51 . The current is delivered to rotate the dc motor in the direction and at the speed corresponding to the shift actuator drive signal supplied from the main microcomputer 1 .
In the preferred configuration, the motorcycle 100 comprises a single clutch and torque is transferred between the engine 106 and a suitable transmission by the action of the single clutch. The engagement and disengagement of the clutch advantageously are performed by a drive force, such as that supplied by electric power rather than, or in addition to, that provided by human power. Thus, the motorcycle 100 preferably also comprises the clutch actuator 41 , which is controlled by the control device 10 (see FIG. 2 ).
The clutch actuator 41 preferably uses a motor to operate a clutch that is provided in a crankcase of the engine 106 . In one preferred configuration, the clutch actuator 41 comprises a direct current (dc) motor. Other suitable types of motors or linear actuators also can be used. In the preferred configuration, forward rotation of the dc motor can disengage the clutch while reverse rotation of the dc motor can engage the clutch or put the clutch in a desired position between the disengaged state and the engaged state. Other suitable arrangements also can be used.
The clutch actuator 41 can be mounted above the engine 106 . In a preferred configuration, the clutch actuator 41 is mounted in a region above the engine 106 and below the fuel tank 108 . The clutch lever 104 can be connected to the clutch actuator 41 by a length of wire so that engagement and disengagement of the clutch also can be performed by the operator of the vehicle by manipulating the clutch lever 104 .
A clutch potentiometer 44 preferably is mounted to the clutch actuator 41 . The clutch potentiometer 44 can comprise a resistor and other suitable electrical components such that a voltage indicative of an operational state of the clutch actuator 41 (e.g., a voltage indicative of the clutch position) can be supplied to the control device 10 . Any suitable configuration can be used that supplies information regarding the clutch position to the control device 10 .
The motorcycle 100 preferably also comprises the shift actuator 51 . In one configuration, the shift actuator 51 comprises a motor that operates a transmission provided in a transmission casing of the engine 106 . The shift actuator 51 preferably comprises a dc motor (not shown). Other suitable types of motors or linear actuators also can be used.
The shift actuator 51 also can be controlled by the control device 10 . Preferably, the shift actuator 51 is mounted to a shift arm of the transmission. In the illustrated configuration, forward rotation of the motor can cause up-shifting of the transmission and reverse rotation of the motor can cause down-shifting of the transmission. Other configurations are possible. The transmission can feature a shift dog or any other suitable shifting configuration that is connected to the shift arm. In one configuration, the transmission is shiftable among neutral and multiple forward speeds. Preferably, the transmission is shiftable among neutral and five forward speeds.
A shift potentiometer 54 preferably is mounted to the shift actuator 51 . The shift potentiometer 54 can comprise a resistor and other suitable electrical components such that voltage indicative of an operational state of the shift actuator 51 (e.g., a voltage indicative of the shift actuator/shift lever position) can be supplied to the control device 10 . Any suitable configuration can be used that supplies information regarding either or both of the shift actuator position and shift lever position. In the preferred embodiment, the voltage value is indicative of the turning angle or position of the shift arm.
The shift actuator control unit 19 turns the shift actuator 51 from a reference angle to a maximum angle after a predetermined period, described later, when a gear change is instructed by a rider. The shift cam shaft rotates when the shift actuator 51 turns such that the gear engaged by a shift fork is moved. While the shift cam shaft rotates when the shift actuator 51 turns in the course of a shift motion, the shift cam shaft preferably does not remain joined to the shift actuator 51 when the shift actuator 51 returns to the reference angle. The shift cam shaft, therefore, remains in position when the shift actuator 51 is reset and awaiting the next shift command.
As used herein, the reference angle preferably is a neutral position in which the shift actuator 51 is not turned in either an up-shift direction or in a down-shift direction. Also, the maximum angle preferably is a position that is necessary and sufficient to cause a single up-shift or down-shift.
Preferably, the shift actuator control unit 19 receives input from the shift potentiometer 54 . As explained above, the shift potentiometer 54 outputs a voltage that is indicative of the shift actuator/shift lever position. Based upon the output of the shift potentiometer 54 , for instance, the shift actuator control unit 19 can stop the movement of the shift cam shaft when the shift actuator 51 has turned a sufficient amount to shift gears.
With reference again to FIG. 4 , the clutch actuator control unit 11 preferably comprises a clutch disengagement motion unit 18 , a clutch engagement motion unit 16 , a clutch engagement speed varying unit 14 , a clutch rotating speed difference calculating unit 12 , a gear movement completion judging unit 21 , and a second engagement motion starting clutch position acquiring unit 13 .
The clutch disengagement motion unit 18 and the clutch engagement motion unit 16 provide control signals that are used to control the clutch actuator 41 . The clutch disengagement motion unit 18 operates the clutch actuator 41 to cause the clutch to transition from the engaged state to the completely disengaged state (i.e., a clutch disengagement motion). Similarly, the clutch engagement motion unit 16 operates the clutch actuator to cause the clutch to transition from the disengaged state to the semi-engage or fully engaged state or from the semi-engaged state to the fully engaged state.
The clutch disengagement motion unit 18 operates the clutch actuator 41 if, for example, gear change instructing information has been input from the up-shift switch 91 or the down-shift switch 96 . In the course of the clutch disengagement motion, the clutch disengagement motion unit 18 acquires clutch position information from the clutch potentiometer 44 to judge whether the clutch has reached the completely disengaged state. When the clutch reaches the completely disengaged state, the clutch disengagement motion unit 18 stops movement of the clutch actuator 41 .
The gear movement completion judging unit 21 acquires gear position information from the gear position sensor 93 . After the clutch starts the disengagement motion, the gear position is monitored on the basis of the gear position information and it is judged whether the gear shift has been completed. If the selected gear combination is engaged, it is judged that the gear movement has been completed. In the illustrated configuration, once it is judged that the gear movement has been completed, the clutch rotating speed difference calculating unit 12 communicates the clutch rotating speed difference to the clutch engagement speed varying unit 14 and to the second engagement motion starting clutch position acquiring unit 13 .
In one configuration, the clutch rotating speed difference calculating unit 12 acquires the clutch rotating speed difference, which is the difference in rotating speed between the drive side and the driven side of the clutch. Preferably, the clutch rotating speed difference calculating unit 12 acquires clutch rotating speed information from the first clutch rotating speed sensor 94 and from the second clutch rotating speed sensor 95 and calculates a difference between the rotating speeds to arrive at the clutch rotating speed difference information. Other techniques also can be used to arrive at the clutch rotating speed difference or a pseudo-value that indicates output that can be used for the same purpose as the clutch rotating speed difference.
The second engagement motion starting clutch position acquiring unit 13 comprises a pre-stored second engagement motion starting clutch position map, in which a second engagement motion starting clutch position and a clutch rotating speed difference correspond to each other. In the second engagement motion starting clutch position map, a second engagement motion starting clutch position is set between a completely disengaged state and a completely engaged state of the clutch.
FIG. 5 shows an example of a second engagement motion starting clutch position map. In the illustrated configuration, the abscissa indicates a clutch rotating speed difference obtained by subtracting a main-shaft side clutch rotating speed from an engine-side clutch rotating speed. The ordinate indicates a second engagement motion starting clutch position. Any suitable manner of creating a relationship between the speed differences and the clutch positions can be used.
As shown in the figure, a second engagement motion starting clutch position assumes a generally constant value (v 1 in the figure) between about 0 rpm and a predetermined absolute value of a rotating speed difference r 1 . The second engagement motion starting clutch position increases in proportion to the absolute value of the rotating speed difference between r 1 to a predetermined absolute value of a rotating speed difference r 2 , which is larger than r 1 . The second engagement motion starting clutch position assumes a second generally constant value (v 2 in the figure) at absolute values of rotating speed differences that are greater than or equal to a predetermined absolute value of a rotating speed difference r 2 . Thus, in the mid-range between r 1 and r 2 , the starting clutch position increases in proportion to the magnitude of the clutch rotating speed difference. If the clutch rotating speed difference is large, the second engagement motion is started earlier than if the clutch rotating speed difference is small. By doing this, more rapid and smooth clutch engagement can be accomplished.
Thus, the second engagement motion starting clutch position acquiring unit 13 determines from the second engagement motion starting clutch position map the second engagement motion starting clutch position on the basis of the reported clutch rotating speed difference. The second engagement motion starting clutch position is communicated to the clutch engagement speed varying unit 14 by the second engagement motion starting clutch position acquiring unit 13 .
The clutch engagement motion unit 16 operates the clutch actuator 41 on the basis of the engagement speed communicated from the clutch engagement speed varying unit 14 . If the clutch engagement speed varying unit 14 stops communication of the engagement speed, movement of the clutch actuator 41 also is stopped. Acquisition of the second engagement speed is performed on the basis of one or more pre-stored second engagement speed maps, which can be contained in a clutch engagement speed storage unit 15 . The second engagement speed maps preferably correlate the clutch rotating speed and the desired second engagement speed. Any other suitable technique for establishing the correlated values can be used. For instance, the second engagement speed corresponding to the acquired clutch rotating speed difference can be found by pre-storing one or more formulas indicative of the relationship between a clutch rotating speed difference and a second engagement speed. Thus, simple calculations can be conducting using the formulas.
The clutch engagement speed storage unit 15 preferably forms a portion of the clutch engagement speed varying unit 14 . In one embodiment, a first map is provided for up-shifting operations (see FIG. 6 ) and a second map is provided for down-shifting operations (see FIG. 7 ). By providing maps for both operations, it is possible to simplify calculations such that the clutch engagement speed varying unit 14 can acquire the desired second engagement speed in a shorter time. In another embodiment, all of the data for both up-shifting and down-shifting is contained in a single map. More preferably, the maps preferably comprise data for each possible gear change. The data, of course, preferably correlates the clutch rotating speed difference to the desired second engagement speed. Thus, it is possible to more rapidly acquire the desired clutch engagement speed for each gear shift combination.
In one configuration, the second engagement speed maps preferably are constructed such that when the absolute value of the clutch rotating speed difference becomes a value between a predetermined value r 1 and a predetermined value r 2 , which is smaller than r 1 , the second engagement speed varies as the absolute value of the clutch rotating speed difference decreases. Preferably, in this configuration, the second engagement speed assumes a minimum value at the predetermined value r 2 . Where the absolute value of the clutch rotating speed difference in this configuration is smaller than the predetermined value r 2 , the second engagement speed assumes its minimum value irrespective of variation in the absolute value of the clutch rotating speed difference.
During up-shifting, the up-shifting second engagement speed map, such as that shown in FIG. 6 , can be used. Other maps also can be used. As shown, the abscissa indicates the clutch rotating speed difference and the ordinate indicates a rotating speed of the clutch actuator 41 that corresponds to the second engagement speed.
As shown in FIG. 6 , up to eight different clutch engagement speeds can be used. More engagement speeds or less engagement speeds can be used in other configurations. If the clutch rotating speed difference is between the predetermined rotating speed difference r 1 to the predetermined rotating speed difference r 2 , which is smaller than r 1 , the second engagement speed will decrease as the clutch rotating speed difference decreases. The rate at which the clutch engagement speed decreases begins to increase at the predetermined rotating speed difference r 3 , which is between the predetermined rotating speed differences r 1 and r 2 . If the clutch rotating speed difference is between the predetermined rotating speed difference r 2 to another predetermined rotating speed difference r 4 , which is smaller than r 2 , the clutch engagement speed preferably is a generally constant value (V 1 or V 2 or V 4 in the figure). Also, if during an up-shift an abnormality occurs in the operation of the engine or in the driving of the vehicle such that the driven member of the clutch is rotating faster than the drive member of the clutch (i.e., the clutch rotating speed difference becomes equal to or less than the predetermined rotating speed difference r 4 ), then the clutch engagement speed becomes a constant level (V 5 or V 6 or V 8 in the figure) that is higher than when the clutch rotating speed difference is in the range from the predetermined rotating speed difference r 2 to r 4 .
With reference now to FIG. 7 , an example of the second engagement speed map used during downshifting is shown therein. As illustrated, the abscissa comprises the clutch rotating speed difference and the ordinate comprises the rotating speed of the clutch actuator 41 that corresponds to the second engagement speed.
As shown, during a down-shift, if the clutch rotating speed difference is in the range from the predetermined rotating speed difference r 1 to another predetermined rotating speed difference r 2 , the absolute value of which is set to be smaller than the absolute value of r 1 , the second engagement speed decreases as the clutch rotating speed difference moves from r 1 toward r 2 . The curves illustrate that the rate of the clutch engagement speed decreases at a first rate over the range between r 1 and r 3 and at a faster rate over the range between r 3 and r 2 . If the clutch rotating speed difference is in the range between the predetermined rotating speed difference r 2 to another predetermined rotating speed difference r 4 , which is smaller than r 2 , the clutch engagement speed is generally constant (e.g., V 1 , V 3 , V 4 , or V 5 in the figure). If there is an abnormality in the operation of the engine or the driving of the vehicle such that the drive member of the clutch rotates faster than the driven member, and the clutch rotating speed difference becomes less than or equal to the predetermined rotating speed difference r 4 , the speed is set such that engagement of the clutch will be performed at a higher speed than if the clutch rotating speed difference is in the range defined between the predetermined rotating speed differences r 2 and r 4 .
With reference to FIGS. 6 and 7 , the second engagement speed maps preferably are prepared for each gear change, whether it is an up-shift or a down-shift. In making a comparison among clutch engagement speeds for each gear ratio change in terms of the same clutch rotating speed difference, the second engagement speed in the higher gears is greater than or equal to the engagement speed in the lower gears. For example, as shown in FIGS. 6 and 7 , with the same clutch rotating speed difference, the clutch engagement speed when the transmission shifts from 4 th gear to 5 th gear is generally the same as or faster than the clutch engagement speed when the transmission shifts from 3 rd gear to 4 th gear. Similarly, the clutch engagement speed when the transmission shifts from 3 rd gear to 4 th gear is generally the same as or faster than the clutch engagement speed when the transmission shifts from 1 st gear to 2 nd gear. Such an arrangement improves the feel of the gear change in all ratio changes.
The clutch engagement speed varying unit 14 acquires from the map the second engagement speed that corresponds to the clutch rotating speed difference acquired from the clutch rotating speed difference calculating unit 12 . The second engagement speed thus acquired is communicated to the clutch engagement motion unit 16 and the clutch actuator 41 can start the second engagement motion. Over the course of the second engagement motion, the second engagement speed advantageously is repeatedly varied at predetermined intervals. That is, the clutch engagement speed varying unit 14 periodically acquires (e.g., every 1 msec) from the clutch rotating speed difference calculating unit 12 the most current clutch rotating speed difference information.
While the clutch rotating speed difference can be found periodically, such as every 1 msec, other configurations are possible. For instance, it suffices to be performed at other generally short intervals relative to the period of time required for engagement of the clutch. A smooth engagement motion of the clutch is realized even within, for example, a short period of time in the order of several milliseconds. In addition, in some configurations, the clutch rotating speed difference may be detected once every one engine cycle. Moreover, if the clutch rotating speed difference can be detected in the same cycle as that used for the control cycle of the clutch actuator 41 , otherwise wasteful detection of the clutch rotating speed difference can be eliminated. In other words, if the clutch rotating speed difference is detected in a shorter period than the control cycle of the clutch actuator 41 , the clutch rotating speed difference information that is useful for control of the clutch actuator 41 also is generated. Accordingly, by detecting the clutch rotating speed difference in the same cycle as the control cycle of the clutch actuator 41 , it is possible to eliminate the generation of clutch rotating speed difference information that is not used for control of the clutch actuator 41 , thereby simplifying the control device 10 .
With reference now to FIG. 8 , the clutch position at the time of up-shift, the turning angle of the shift actuator 51 , the gear position, and how these vary over time, of an embodiment of the present invention are shown therein. FIG. 8( a ) illustrates the time-variation of the clutch position. FIG. 8( b ) illustrates the time-variation of the turning angle of the shift actuator 51 . FIG. 8( c ) illustrates the time-variation of the gear position.
First, when a rider requests an up-shift by manipulating the up-shift switch 91 , the clutch disengagement motion unit 18 starts moving the clutch actuator 41 . Thus, the clutch disengagement motion is started (see FIG. 8 , t 1 ). In the clutch disengagement motion, the clutch disengagement motion unit 18 judges on the basis of clutch position information when the clutch has reached a completely disengaged state ( FIG. 8 , clutch position C 2 ). When the clutch reaches the completely disengaged state, the clutch actuator 41 is stopped and the clutch is maintained in the completely disengaged state (see FIG. 8 , t 5 ).
After a shift motion lag time (T) has elapsed following the request by the rider, the shift actuator control unit 19 starts moving the shift actuator 51 . The lag time T preferably is sufficient to allow the clutch to move from the fully engaged state to the semi-engaged state, which will reduce the forces on gears. Thus, a shifting action is begun (see FIG. 8 , t 2 ). When a turning angle of the shift actuator reaches the shift maximum turning angle, the clutch actuator 51 is stopped and the clutch actuator 51 is maintained at the shift maximum turning angle (see FIG. 8 , t 4 ). Movement of the clutch actuator 51 causes the shift cam shaft to rotate and a sliding gear begins to move on a spline on a main shaft or a counter shaft (see FIG. 8 , t 3 ). During the gear movement, as is shown by the portion that appears as a brief plateau between t 5 and t 6 , the dogs do not typically engage upon contact but typically may grind together prior to interlocking. After the dogs grind together, the sliding gear or the driven-side gear rotates whereby grinding of the dogs diminishes and movement of the sliding gear is complete (see FIG. 8 , t 6 )
Having detected that the gear shift has been completed, the gear movement completion judging unit 21 communicates such detection to the second engagement motion starting clutch position acquiring unit 13 and the clutch engagement speed varying unit 14 . The second engagement motion starting clutch position acquiring unit 13 acquires a second engagement motion starting clutch position (see FIG. 8 , a clutch position C 3 ) from a clutch rotating speed difference and the second engagement motion starting clutch position is communicated to the clutch engagement speed varying unit 14 .
The clutch engagement speed varying unit 14 communicates a first engagement speed to the clutch engagement motion unit 16 once the gear movement is completed and the first engagement motion is started. The first engagement speed is maintained up to the second engagement motion starting clutch position. The clutch engagement speed varying unit 14 monitors the clutch position in the first engagement motion and stops communication of the first engagement speed to the clutch engagement motion unit 16 once it is determined that the second engagement motion starting clutch position is reached (see FIG. 8 , t 7 ). The first engagement motion then is terminated.
When the clutch reaches the second engagement motion starting clutch position, the clutch engagement speed varying unit 14 begins to acquire a second engagement speed from the second engagement speed map, and the second engagement speed is communicated to the clutch engagement motion unit 16 . Thus, the second engagement motion is started. In the second engagement motion, the second engagement speed is periodically varied on the basis of the second engagement speed map. Hence, the associated line is slightly curved.
Once the clutch position and the clutch rotating speed difference meet the second engagement motion terminating condition, (i.e., the clutch rotating speed difference is less than or equal to the second engagement motion termination enabling rotating speed difference and the clutch position is less than or equal to the second engagement motion termination enabling position—see FIG. 8 , a clutch position C 4 ), the clutch engagement speed varying unit 14 stops acquisition of the second engagement speed and begins to communicate the third engagement speed to the clutch engagement motion unit 16 . Thus, the second engagement motion is terminated and the third engagement speed is started (see FIG. 8 , t 8 ). In the third engagement motion, once it is determined that the clutch has reached the completely engaged state (see FIG. 8 , a clutch position C 1 ), the clutch engagement speed varying unit 14 stops communication of the third engagement speed to the clutch engagement motion unit 16 and stops the movement of the clutch actuator 41 (see FIG. 8 , t 9 ).
When the second engagement motion is terminated, the clutch engagement speed varying unit 14 communicates the termination of the second engagement motion to the shift actuator control unit 19 . After the second engagement motion is terminated, the shift actuator control unit 19 starts a shift return motion to return the shift actuator 51 to the reference angle (see FIG. 8 , t 8 ). Once it is determined that the turning angle of the shift actuator 51 has reached the reference angle, the shift actuator control unit 19 stops the movement of the shift actuator 51 (see FIG. 8 , t 10 ).
Accordingly, the clutch can be connected at the generally constant first engagement speed, which is faster than the second engagement speed, in the course of the engagement motion until the clutch reaches the second engagement motion starting clutch position, which is somewhere between the completely disengaged state and the completely engaged state of the clutch. After the clutch reaches the second engagement motion starting clutch position, it is engaged at the second engagement speed, which is periodically varied in accordance with the variation in the clutch rotating speed difference. When the clutch rotating speed difference and the clutch position meet the second engagement motion terminating conditions, the clutch is engaged at the third engagement speed, which also is generally constant with time.
FIG. 9 presents a graphical depiction of an embodiment undergoing a down-shift and the time-variation of the clutch position, the turning angle of the shift actuator 51 , and the gear position. FIG. 9( a ) illustrates the time-variation of a clutch position. FIG. 9( b ) illustrates the time-variation of the turning angle of the shift actuator 51 . FIG. 9( c ) illustrates the time-variation of the gear position.
As illustrated, at the time of a down-shift, after down-shift instructions have been communicated and after the clutch has been disengaged, engagement and disengagement motions of the clutch are performed generally in the order of the first engagement motion, the second engagement motion, and the third engagement motion. In other words, once the down-shift instructions are communicated to the clutch disengagement motion unit 18 , disengagement movement of the clutch is started (see FIG. 9 , t 1 ). Once the clutch reaches the completely disengaged state and the shifting of the gears has been completed, the engagement motion of the clutch is started (see FIG. 9 , t 6 ). The clutch is engaged at a first engagement speed, which is generally constant with time, until the clutch reaches the second engagement motion starting clutch position between the completely disengaged state and the completely engaged state of the clutch (see FIG. 9 , t 7 ). After the clutch reaches the second engagement motion starting clutch position, the clutch is engaged at that second engagement speed, which is periodically varied according to variation in the clutch rotating speed difference. When the clutch rotating speed difference and the clutch position meet the second engagement motion terminating conditions, the clutch is engaged at the third engagement speed, which is generally constant with time (see FIG. 9 , t 8 ). Once the clutch reaches the completely engaged state, the engagement motion of the clutch is terminated and the clutch is remains in the completely connected state (see FIG. 9 , t 9 ).
During downshifting, after the shift motion lag time (T) has elapsed following the downshift instructions, the shift actuator 51 rotates in the opposite direction relative to the direction associated with the up-shift and the shift motion is started (see FIG. 9 , t 2 ). After the maximum is reached, the turning angle of the shift actuator 51 is maintained. Once the clutch position and the clutch rotating speed difference meet the second engagement motion terminating conditions, the shift return motion is started (see FIG. 9 , t 8 ). Once the turning angle of the shift actuator has reached the reference angle, the shift actuator 51 is stopped (see FIG. 9 , t 10 ).
With respect to gear position, the shift actuator 51 begins the shifting movement whereby the sliding gear is urged into movement (see FIG. 9 , t 3 ). After the sliding gear begins movement, the sliding gear and the driven-side gear engage with each other following possible grinding of the dogs of the sliding gear and the driven-side gear (see FIG. 9 , t 6 ).
With reference now to FIG. 10 and FIG. 11 , the rider can indicate a desire to change gears by actuating (e.g., placing in or toggling into an ON position) either the up-shift switch 91 or the down-shift switch 96 . See S 101 . When the rider actuates the up-shift switch 91 or the down-shift switch 96 , gear shift instructing information indicative of the desired up-shift or down-shift is communicated to the control device 10 (e.g., the main microcomputer 1 ).
The clutch actuator control unit 11 then operates the clutch actuator 41 to disengage the clutch. See S 102 . In one configuration, the clutch actuator control unit 11 outputs a clutch actuator control signal to the motor drive circuit 42 . The clutch actuator control signal thereby operates the clutch actuator 41 and disengagement of the clutch begins. While the clutch is being disengaged, the clutch disengagement motion unit 18 determines, based upon clutch position information, whether the clutch has reached the completely disengaged state. See S 103 . Once the clutch has become disengaged, the clutch actuator 41 is stopped. See S 104 . As used herein, “disengaged” corresponds to a clutch position in which a drive force of an engine generally is not transmitted to the transmission and/or the wheels.
After gear change instructing information is communicated from the up-shift switch 91 or the down-shift switch 96 , the shift actuator control unit 19 preferably tracks the passage of time from the command or communication. The passage of time can be used to accommodate the disengagement of the clutch, for instance.
When it is judged that a predetermined period has elapsed (i.e., a shift motion start lag time), the shift actuator control unit 19 turns the shift actuator 51 in a direction that corresponds to the requested gear change. Preferably, the shift actuator control unit 19 outputs a shift actuator control signal to the motor drive circuit 52 , which effects movement of the shift actuator 51 . While the shift arm turns, the shift cam shaft that is engaged by the shift arm rotates with the shift arm to realize a gear change.
During the shifting motion, the shift actuator control unit 19 monitors the angle that the shift actuator 51 turns with shift-actuator turning angle information acquired from the shift potentiometer 54 . The shift actuator control unit 19 determines whether the shift actuator 51 has reached the maximum angle. The shift actuator control unit 19 stops movement of the shift actuator 51 when the shift actuator 51 reaches the maximum angle. Thus, the shift actuator 51 preferably stops at the maximum angle.
The clutch actuator control unit 11 acquires gear position information from the gear position sensor 93 to evaluate when the gear movement has been completed. Preferably, the gear movement completion judging unit 21 acquires the gear position information from the output voltage of the gear position sensor 93 to judge whether the gear shift has been completed. Until completion of gear movement, acquisition of gear position and the judgment of completion or incompletion preferably repeat. See S 105 . When it is judged that the gears have successfully been shifted, the gear movement completion judging unit 21 communicates such judgment to the second engagement motion starting clutch position acquiring unit 13 and to the clutch engagement speed varying unit 14 .
Clutch engagement motion then is started. See S 106 . In other words, the control unit 10 starts transitioning from the completely disengaged state to the engaged state (i.e., a clutch engagement motion) when it is determined that the gear change has been completed. See FIG. 11 .
The second engagement motion starting clutch position acquiring unit 13 acquires clutch rotating speed difference information from the clutch rotating speed difference calculating unit 12 . See S 201 . On the basis of the clutch rotating speed difference, the second engagement motion starting clutch position acquiring unit 13 determines a second engagement motion starting clutch position from the second engagement motion starting clutch position map. See S 202 . The second engagement motion starting clutch position acquiring unit 13 communicates the acquired second engagement motion starting clutch position to the clutch engagement speed varying unit 14 .
In the course of the clutch engagement motion, the clutch actuator control unit 11 first performs an engagement motion of the clutch at the first engagement speed (i.e., the first engagement motion). Here, the first engagement speed is the engagement speed of the clutch that has been pre-stored in the clutch actuator control unit 11 or an associated memory location. Preferably, the first engagement speed is generally constant with time.
The clutch engagement speed varying unit 14 communicates the first engagement speed to the clutch engagement motion unit 16 whereby the first engagement motion is started. See S 203 . Preferably, the clutch engagement motion unit 16 operates the clutch actuator 41 on the basis of the communicated clutch engagement speed. In some configurations, the first engagement motion can begin before the clutch rotating speed difference information and the corresponding second engagement motion starting clutch position are obtained.
During the first engagement motion, the clutch engagement speed varying unit 14 judges on the basis of clutch position information whether the clutch position has reached the second engagement motion starting clutch position. See S 204 . When the first engagement motion begins, the second engagement motion starting clutch position is communicated to the clutch engagement speed varying unit 14 from the second engagement motion starting clutch position acquiring unit 13 . During the first engagement motion, the clutch engagement speed varying unit 14 monitors the clutch position on the basis of clutch position information acquired from the clutch potentiometer 44 to determine whether the second engagement motion starting clutch position has been attained. When it is determined that the clutch has reached the second engagement motion starting clutch position, communication to the clutch engagement motion unit 16 is stopped. In other words, the first engagement motion continues until the second engagement motion starting clutch position is reached.
When the clutch position reaches the second engagement motion starting clutch position, the clutch engagement speed varying unit 14 acquires clutch rotating speed difference information from the clutch rotating speed difference calculating unit 12 . See S 205 . The clutch engagement speed varying unit also acquires, on the basis of the clutch rotating speed difference information, the second engagement speed from the second engagement speed map stored in the clutch engagement speed storage unit 15 . See S 206 .
While the second engagement motion makes use of mapped data, it is possible to feature a clutch engagement configuration in which a clutch engagement speed may be acquired from a map or equation beginning with the first engagement motion. In such a configuration, the engagement speed map can feature an initial connection speed that is faster than the second engagement speed until the clutch rotating speed difference becomes less than or equal to a predetermined threshold. Other configurations also can be used.
In any event, the second engagement speed is communicated to the clutch engagement motion unit 16 , engagement of the clutch is performed at the second engagement speed, and the second engagement motion is started. See S 207 . The second engagement speed preferably is determined according to a sensed or actual difference in clutch component rotating speeds (i.e., a second engagement speed). In one preferred embodiment, the second engagement speed advantageously is one that is slower than the first engagement speed and the clutch actuator control unit 11 changes the speed over time based upon the sensed or actual difference in clutch component rotating speeds.
During the second engagement motion, the clutch actuator control unit 11 preferably samples the clutch rotating speed difference at predetermined intervals (e.g., every 1 msec). The clutch actuator control unit 11 comprises the second engagement speed map that correlates clutch rotating speed differences with desired second engagement speeds. When the clutch rotating speed difference is acquired, the clutch actuator control unit 11 acquires from the second engagement speed map the second engagement speed that corresponds to the acquired clutch rotating speed difference. Once the second engagement speed is acquired, the clutch actuator 41 is instructed to move the clutch at the acquired second engagement speed. As a result, when a clutch rotating speed difference varies in the course of the second engagement motion, the second engagement speed also varies according to the variation.
In the second engagement motion, the clutch engagement speed varying unit 14 acquires clutch rotating speed difference information and clutch position information to judge whether the clutch rotating speed difference and the clutch position meet the second engagement motion terminating conditions. See S 208 . If the second engagement motion terminating condition is not met, the procedure returns again to the processing of S 205 to perform engagement of the clutch at the second engagement speed, which is varied according to the clutch rotating speed difference. When both the clutch position and the clutch rotating speed difference meet the predetermined conditions (i.e., a second engagement motion terminating condition) during the second engagement motion, the clutch actuator control unit 11 terminates the second engagement motion. The second engagement motion terminating condition preferably requires that the clutch rotating speed difference is less than or equal to a second motion termination enabling rotating speed difference and that the clutch position is less than or equal to a second motion termination enabling position.
When both the clutch position and the clutch rotating speed difference meet the second engagement motion terminating condition (i.e., when the second engagement motion is terminated), the clutch engagement speed varying unit 14 stops communication of the second engagement speed to the clutch engagement motion unit 16 and starts communicating the third engagement speed. In addition, when the clutch position and the clutch rotating speed difference meet the second engagement motion terminating condition, the clutch engagement speed varying unit 14 communicates such judgment to the shift actuator control unit 19 .
Receiving such a communication, the shift actuator control unit 19 turns the shift actuator 51 in the direction that returns the shift actuator to the reference angle. In the course of this shift return motion, the shift actuator control unit 19 judges on the basis of shift-actuator turning angle information when the shift actuator 51 reaches the reference angle. When the shift actuator 51 reaches the reference angle, the shift actuator control unit 19 stops the shift actuator 51 . Thus, after receiving from the clutch actuator control unit 11 a communication to the effect that the clutch meets the second engagement motion terminating condition, the shift actuator control unit 19 performs a motion to return the shift actuator 51 to the reference angle (a shift return motion).
In the second engagement motion, if it is determined that the clutch position and the clutch rotating speed difference meet the second engagement motion terminating condition. See S 208 . The clutch engagement speed varying unit 14 then terminates communication of the second engagement speed to the clutch engagement motion unit 16 and begins to communicate the third engagement speed thereto. See S 209 . The third engagement speed preferably does not vary with time. More preferably, the third engagement speed is one that is slower than the second engagement speed and the clutch actuator control unit 11 does not vary the speed over time. Thus, the third engagement motion is started.
In some configurations, however, the clutch engagement speed for the third engagement motion may be acquired on the basis of an engagement speed map, either the same map as that used for the second engagement motion or another one in which the clutch rotating speed difference and the clutch engagement speed correspond to each other. Formulas also can be used. Movement based upon such maps or formulas can continue until the clutch reaches the completely connected state without setting the second engagement motion terminating condition. An engagement speed map can be set so that the clutch engagement speed increases relative to the second engagement speed when then clutch rotating speed difference becomes less than or equal to a predetermined threshold.
In the third engagement motion, the clutch engagement speed varying unit 14 monitors the clutch position on the basis of clutch position information to judge whether the clutch has reached the completely engaged state. See S 210 . If the clutch has reached the completely engaged state, the clutch engagement speed varying unit 14 terminates communication of the second engagement speed to the clutch engagement motion unit 16 and the clutch engagement motion unit 16 stops the clutch actuator 41 . Thus, the engagement motion of the clutch is terminated. See S 211 .
If the clutch does not reach the completely engaged state, steps S 209 and S 210 are repeated and the third engagement motion is continued, during which the clutch engagement speed varying unit 14 continues to monitor the clutch position to judge when the clutch has reached the completely engaged state. See S 210 .
Although the present invention has been described in terms of a certain embodiment, other embodiments apparent to those of ordinary skill in the art also are within the scope of this invention. Thus, various changes and modifications may be made without departing from the spirit and scope of the invention. For instance, various components may be repositioned as desired. Moreover, not all of the features, aspects and advantages are necessarily required to practice the present invention. Accordingly, the scope of the present invention is intended to be defined only by the claims that follow. | Engagement of a clutch is at least partially controlled based upon the difference in rotational speed between the drive side of the clutch and the driven side of the clutch. As the rotational speed difference varies, the approach rate of the drive side and the driven side also varies for at least part of the total distance defined between the drive side and the driven side when the clutch is disengaged. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is related to the following pending applications being concurrently filed herewith and assigned to the assignee of the present invention:
Our
Title
Docket No.:
Modular Rooftop Air Conditioner for a Bus
210_546
Modular Bus Air Conditioning System
210_545
Supply Air Blower Design in Bus Air Conditioning Units
210_549
Bus Rooftop Condenser Fan
210_550
Method and Apparatus for Refreshing Air in a Bustop Air
210_548
Conditioner
Coil Housing Design for a Bus Air Conditioning Unit
210_547
Integrated Air Conditioning Module for a Bus
210_558
Fresh Air Intake Filter and Multi Function Grill
210_554
Integrated Air Conditioning Module for a Bus
210_557
Modular Air Conditioner for a Bus
210_561
Modular Air Conditioner for a Bus Rooftop
210_562
Evaporator Section for a Modular Bus Air Conditioner
210_564
Wide Evaporator Section for a Modular Bus Air
210_565
Conditioner
Condensate Pump for Rooftop Air Conditioning Unit
210_568
Condensate Removal System Rooftop Air Conditioning
210_551
Modular Rooftop Unit Supply Air Ducting Arrangement
210_577
Configuration for Modular Bus Rooftop Air Conditioning
210_595
System
Unibody Modular Bus Air Conditioner
210_596
BACKGROUND OF THE INVENTION
This invention relates generally to air conditioning systems and, more particularly, to an air conditioning system for the rooftop of a bus.
The most common approach for air conditioning a bus is to locate the air conditioning components on the rooftop thereof. Inasmuch as power is available from the engine that drives the bus, it has become common practice to locate the air conditioning compressor near the drive engine such that the drive engine is drivingly connected to the compressor, with the compressor then being fluidly interconnected to the air conditioning system on a rooftop of a bus. This, of course, requires rather extensive piping between the engine compartment and the air conditioning unit, thereby increasing installation and maintenance costs.
Another problem with such existing systems is that the speed that the compressor is driven is dependent on the speed in which the drive engine is running. Thus, when the drive engine is idling in a parking lot, for example, the compressor is running at a relatively slow speed which may not be sufficient to provide the desired degree of air conditioning. It is therefore generally necessary to oversize the compressor in order to obtain the performance needed under these conditions.
Others problems associated with such a motor driven compressor system is that the open drive compressor needs a shaft seal and a mechanical clutch, both of which are subject to maintenance problems. Further, since DC power is available on a bus, DC motors have been used for the air conditioning system. In general, DC motors are not as reliable as AC motors since they have brushes that wear out, and brushless motors are relatively expensive.
In addition to the problems discussed hereinabove, it is recognized, that because the wide variety of bus types and application requirements, it has been necessary to provide many different types and variations of air conditioning systems in order to meet these different requirements and vehicle interfaces. As a result, the manufacturing and installation costs, and sustaining engineering resources that are necessary in order to properly maintain and service these units, are relatively high.
Conventionally, bus air conditioning systems have relied on the general leakiness of a bus for purposes of replenishing the air therein. That is, because buses generally have many areas where outside air can leak into the bus and inside air can leak out of the bus, there has been no need to deliberately circulate fresh air into the bus and stale return air out of the bus. However, as buses have become tighter in construction, it has been found that the recirculated air can eventually become stale.
It is therefore an object of the present invention to provide an improved bus top air conditioning system.
Another object of the present invention is the provision for a bus air conditioning system which is effective at all operating speeds of the bus, while at the same time does not require an oversized compressor.
Yet another object of the present invention is the provision for reducing the manufacturing, installation, and maintenance costs of a bus air conditioning system.
Still another object of the present invention is the provision in a rooftop air conditioner for a systemic replenishment of air within the bus.
Yet another object of the present invention is the provision for a bus rooftop air conditioning system which is economical to manufacture and effective in use.
These objects and other features and advantages become more readily apparent upon reference to the following descriptions when taken in conjunction with the appended drawings.
SUMMARY OF THE INVENTION
Briefly, in accordance with one aspect of the invention, an air conditioning module is assembled with its condenser coil, evaporator coil and respective blowers located within the module and so situated that a standard module can accommodate various installation interfaces with different types and locations of return air and supply air ducts on a bus.
In accordance with another aspect of the invention, a plurality of modules can be installed on the roof of a bus, with each pair, being in back-to-back relationship near the longitudinal center line of the bus.
By yet another aspect of the invention, the modules may include a compressor, such that all the necessary refrigerant piping is located entirely on the module, with electrical power being provided to the electrical components on the module from a motor driven generator.
By still another aspect of the invention, an air mixing flap is adjustably positioned between the condenser coil and evaporator coil such that fresh air can be introduced into the flow to the evaporator coil, while at the same time, a portion of the return air is routed to the condenser discharge opening by way of the flap.
In the drawings as hereinafter described, a preferred embodiment is depicted; however various other modifications and alternate constructions can be made thereto without departing from the true sprit and scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a module in accordance with a preferred embodiment of the invention.
FIG. 2 is an alternative embodiment of the invention to include a compressor.
FIG. 3 is a schematic illustration of both a refrigeration circuit and an electrical circuit within a module in accordance with the present invention.
FIG. 4 is a cut away perspective view of a module in accordance with a preferred embodiment of the invention.
FIGS. 5A-5C are sectional views of modules as applied to various types of bus installations in accordance with a preferred embodiment of the invention.
FIGS. 6A-6C are sectional views of a module with an air mixing flaps in various positions.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a module 11 with the cover removed to show the various components including an evaporator coil 12 , a condenser coil 13 , an evaporator blower 14 and drive motor 16 , and a condenser fan motor 17 for driving a condenser fan.
Outside the module 11 is a compressor 18 which is driven by a motor drive 19 to pump refrigerant from the compressor 18 through refrigerant line 21 to the condenser coil 13 and eventually to the evaporator coil 12 by way of an expansion valve 22 (not shown). The refrigerant vapor then passes back to the compressor 18 by way of refrigerant line 23 .
Also shown in FIG. 1 is an electrical resistance heater 24 which is downstream of the evaporator coil 12 such that, for periods of heating, the air is drawn by the evaporator blower 14 through the evaporator coil 12 and the heater 24 such that the air being delivered to the passenger compartment of the bus is heated. The electrical power to the heater 24 , as well as to the evaporator blower motor 16 and the condenser fan motor 17 , are provided by way of an electrical line receiving electric power from a generator or the like, which in turn is driven by the drive motor 19 . The heater 24 can be powered by either DC or AC currents with the heat output being independent of the speed of the drive engine.
Referring now to FIG. 2, a modified module 26 is shown to include all of the components as described hereinabove. Further, it includes a horizontal rotary compressor 27 which is operatively interconnected between the evaporator coil 12 and the condenser coil 13 so as to circulate refrigerant in a manner similar as described hereinabove. The difference over the earlier described system, however, is that the compressor 18 is driven by an electric motor 20 , with the power being provided by way of the generator 29 , driven by the main engine 19 , and an invertor/controller 28 as shown in FIG. 3 . The invertor/controller 28 , which includes a rectifier and an invertor, receives AC power from a generator or alternator 29 and provides, by way of the invertor, controlled AC power to the evaporator blower motor 16 , the condenser blower motor 17 , the compressor drive motor 20 and the heater 24 or alternatively, the heater may be powered by the generator shown by the dotted line of FIG. 3 . Since the invertor/controller 28 is capable of providing controlled AC power, each of the motors are AC motors, thereby ensuring a more maintenance free system.
With the inverter/controller providing controlled AC power, a preferred type of heat 24 is a positive temperature coefficient (PIC) heater wherein electrical resistance increases relatively fast as the temperature increases. Whereas this type of heater is relatively expensive in it initial installation, it acts as a self limiter and does not require a thermostat to maintain a safe temperature limit.
Referring now to FIG. 4, the module is shown with the various components as described hereinabove enclosed within a housing 29 and including a condenser fan 31 . Also shown are the various openings in the housing 29 , including a return air opening 32 , a condenser outlet opening 33 and a condenser/fresh air intake opening 34 . A fresh/return/exhaust air flap 36 is provided between the condenser coil 13 and the evaporator coil 12 to control the mix of air passing to the evaporator coil 12 , depending on the particular demands of the system, as well as the existing ambient conditions. The air flow pattern, as indicated by the arrows, is thus controlled by the condenser fan 31 , the evaporator fan 14 and the position of the air flap 36 . As the return air enters the return air opening 32 , it is caused to flow out the condenser outlet air opening and/or through the evaporator coil 12 depending on the position of the air flap 36 . Similarly, the fresh air coming in the intake opening 34 passes through the condenser coil 13 and then out the condenser outlet air opening 33 and/or, depending on the position of the air flap 36 , it is allowed to pass through the evaporator coil 12 . Thus, with the use of the air flap 36 it is possible to have all of the return air pass through the condenser air outlet opening 33 , with all fresh air passing into the air intake opening 34 and then through the evaporator coil 12 , or when the flap 36 is placed in the other extreme position, all of the return air passes through the evaporator coil 12 and all of the fresh air entering the air intake opening 34 passes through the condenser coil 13 and out the condenser outlet air opening 33 . A more likely operating condition, however, is an intermediate position of the air flap 36 wherein a selective mix of return air and fresh air are passed through the evaporator coil 12 .
As will be seen, a filter 37 is positioned in the air flow stream which enters the fresh air intake opening 34 and passes through the evaporator coil 12 . Its purposes is to filter out any debris that may be in the air stream entering the air intake opening 34 . After passing through the evaporator coil 12 , the conditioned air is caused to flow by the evaporator blower 14 out a supply air opening 38 as shown.
Considering now the manner in which the module 11 is positioned on the rooftop in such a way as to interface with the existing air path openings on the rooftop, reference is made to FIGS. 5 a - 5 c . As will be seen, the position of the various openings on a bus can vary substantially from application to application. For example, in a wide bus application as shown in FIG. 5 a , the supply air duct 39 is located near the outer side of the bus, whereas the return air duct 41 is disposed at a substantial distance from the longitudinal center line thereof. In a narrow bus application as shown in FIG. 5 b , the supply air duct 42 is moved a small distance inwardly from the outer side of the bus, and the return air duct is located adjacent the longitudinal centerline as shown. In a curved-roof bus as shown in FIG. 5 c , the supply air duct 44 is moved slightly more inwardly from the outer side of the bus, and the return air duct 46 is located in an intermediate position, somewhat outwardly of the longitudinal centerline, but not as far as for a wide bus application.
Of course, in all of the bus applications, a balanced arrangement is provided wherein each side of the bus is provided with both a supply air duct and a return air duct, in a substantially mirror image arrangement as shown. Thus, the modules may be placed in back-to-back relationship, with the space therebetween being varied to accommodate the individual application requirements. For example, for the wide bus application of FIG. 5 a , there is a substantial space between the two modules wherein for the narrow bus application of FIG. 5 b , they are substantially in an abutting relationship. For the curved roof bus application, they are somewhat angled from a true horizontal position, with the spacing therebetween being at an intermediate degree as shown. It should be understood that the three types of installations shown are presented as a sampling of the possible installation requirements, and there are also others that have heretofore required unique designs in order to meet the particular requirements. The present design, on the other hand, provides a single module which will meet the needs of all of the various applications of rooftop air conditioners.
As will be seen, the supply air opening is relatively small, and in each of the three cases described above, the module 11 is placed in such a position that the supply air opening 38 is located substantially over the individual supply air ducts 39 , 42 and 44 . The return air opening 32 , on the other hand is relatively large and therefore can accommodate the various positions of the return air ducts 41 , 43 and 46 as shown.
Considering the now the need to refresh the air in the air conditioner system by bringing in fresh air from the outside, the various positions of the fresh air/exhaust air flap 36 are shown in FIGS. 6 a - 6 c . The flap 36 is made up of blades 47 and 48 integrally attached to a pivot point 49 , with the angular orientation therebetween, θ, being about 135°. A related structure is a divider 51 with curvilinear portion 52 protrusion portion 53 , which is mounted at its end and extends transversely across (i.e., into the drawing) the opening 54 between the evaporator coil 12 and condenser coil 13 and a baffle portion 55 .
In FIG. 6 a , the flap 36 is placed in such a position that its blade 47 engages the evaporator coil support structure 56 , while its blade 48 engages the condenser coil support structure 57 . In this position, the opening 54 is closed such that no fresh air can flow from the fresh air inlet 34 into the evaporator coil 12 . Thus, all of the return air coming into the return air opening 32 passes through the evaporator coil 12 as shown, and all of the fresh air entering the fresh air intake opening 34 passes through the condenser coil 13 and out the outlet air opening 33 .
In FIG. 6 b , the flap 36 is rotated clockwise until the blade 47 engages protrusion portion 53 and the blade 48 engages the evaporator coil bottom support 60 . In this position, the flap 36 completely blocks off the flow of return air to the evaporator coil 12 , and at the same time, the opening 54 is completely opened such that some of the fresh air passing into the fresh air intake opening 34 passes through the opening 54 and through the evaporator coil 12 .
In FIG. 6 c , the flap 36 is placed in an intermediate position wherein the blade 47 is between the structure 56 and the curvilinear portion 52 and the blade 48 is suspended downwardly and not engaging any surface. In this position, the upper part of the opening 54 , between the structure 56 and the blade 47 , is open to the flow of fresh air from the fresh air opening 34 , through the opening 54 and to the evaporator 12 . At the same time, there is an open area to the left of the blade 48 wherein the return air may also flow through the evaporator coil 12 . However, the blade 48 does offer some blockage to the flow of the return air and it also acts to divert its flow to the right, between the divider 51 and the condenser coil 13 . This air then passes through the coil 13 and is caused by the fan 31 to exhaust through the opening 33 . In this way, as the return air becomes stale, some of it may be exhausted out of the system and replaced with fresh air.
Of course, it will be understood that the flap 36 can be placed in any other desirable position between those described hereinabove so as to obtain the desired mixture of fresh air with the return air.
It is the intermediate positions of the flap 36 wherein the divider 51 comes into play. For example in the FIG. 6 c position, the divider 51 forms a boundary between the flow of fresh air coming into the opening 54 and the return air being exhausted through the opening between the divider and the condenser coil 13 . The protrusion 53 assists in preventing the exhaust air from being drawn into the flow of fresh air passing through the evaporator coil 12 .
While the present invention has been particularly shown and described with reference to a preferred mode as illustrated in the drawings, it will be understood by one skilled in that various changes and detail may be effected therein without departing from the true sprit and scope of the invention as defined by the claims. | A bustop air conditioning module is provided with an evaporator section having a return air opening and a condenser section having a fresh air opening. A mixer opening is provided between the fresh air opening and the evaporator coil, and a flap is selectively positionable to cover or uncover the mixer opening to allow a selective amount of fresh air to be passed to the evaporator coil. Simultaneously, the flap also to selectively block a portion of the return air flowing to the evaporator coil and at the same allow a portion of the return air to be exhausted from the system. | 1 |
BACKGROUND OF THE INVENTION
The invention was made in the course of work under grants from the Department of Health, Education and Welfare.
The invention relates generally to heart assist devices and, more particularly, to an auxiliary ventricle which augments the circulation of the blood through the body. A dynamic aortic patch is a mechanical auxiliary ventricle which is surgically implanted in the descending thoracic aorta and which provides a movable vessel wall at the location of the implantation. The patch is systematically inflated and deflated by the application of fluidic pressure to move the wall of the patch and thus generate pressure waves in the bloodstream. These pressure waves support the heart by augmenting the circulation of blood thus increasing coronary flow.
A dynamic aortic patch is a permanently implanted circulatory assist device intended for use in supporting the circulation of patients whose cardiac action is chronically inadequate and cannot be restored by established medical or surgical techniques. It is designed to support the heart by augmenting the circulation of blood to the coronary vessels and peripheral vasculature.
The original dynamic aortic patch included a flexible bladder to which was cemented a Dacron covering sheet which was non-thrombogenic. The use of the initial dynamic aortic patch was published in "Transactions of the American Society of Artificial Internal Organs," Volume XVIII, Page 159 (1972), and in "Transplant Proceedings," Volume III, p. 1459 (1971).
The dynamic aortic patch as previously published included a flexible hollow tube connected to the bladder. The bladder was systematically inflated and deflated by the introduction of fluid pressure, such as compressed gas, through the tube and into the bladder. During the implantation of the bladder extracorporeal bypass was necessary.
Various problems were noted with the original dynamic aortic patch. At first, since the bladder and cover were cemented together prior to implantation, there was always the inherent danger of damaging the bladder by puncturing it during suturing. This, of course, significantly increased the time necessary to implant the apparatus and hence the time that the patient was on a heart-lung machine.
Second, if it was necessary to later replace the bladder component because of normal wear, the entire apparatus had to be removed and a new patch sutured in place. This, again, required extracorporeal bypass.
Hence, the present invention overcomes these problems by providing an improved dynamic aortic patch having none of these shortcomings.
SUMMARY OF THE INVENTION
The present invention provides an improved dynamic aortic patch including separable bladder and envelope components. The envelope is sutured in place during extracorporeal bypass. Extracorporeal bypass is terminated and the bladder is inserted into the envelope. Hence, there can be no damage by puncturing the bladder during the implantation of the envelope.
By use of distinct, discrete bladder and envelope components, when it is necessary to replace the bladder component at a later time, it is not necessary to utilize extracorporeal bypass. A portion of the envelope is opened and the complete bladder is removed and a new bladder is inserted.
The bladder includes longitudinal reinforcing filaments which prevent the bladder from closing upon itself and entrapping gas therein.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing advantages of the present invention, together with other advantages which may be attained by its use, will become more apparent upon reading the following detailed description taken in conjunction with the drawings. In the drawings, wherein like reference numerals identify corresponding components:
FIG. 1 is a perspective illustration of the inflatable bladder of the present invention;
FIG. 2 is a cross sectional view of the bladder as seen in the plane of arrows 2--2 of FIG. 1;
FIG. 3 is a perspective illustration of the dynamic aortic patch with the bladder inserted within the envelope;
FIG. 4 is a cross sectional view of the dynamic aortic patch as seen in the plane of arrows 4--4 of FIG. 3;
FIG. 5 is a schematic representation of the implantation of the dynamic aortic patch and the operation of the dynamic aortic patch; and
FIG. 6 is a cross section of the implanted patch as seen in the plane of arrows 6--6 of FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
By way of background, it is, of course, understood there are certain primary requirements for a surgically implanted dynamic aortic patch. The bladder itself must be air tight and sufficiently flexible to expand and deflate at the required speeds and pressures. The envelope or covering material presents a surface to the blood and, of course, this surface must be non-thrombogenic. When the envelope is implanted, the implantation contact surface between the envelope and the incised vessel wall must be air tight to prevent leakage of blood into the thoracic cavity. These requirements are well understood by those skilled in the art.
Referring more particularly to the drawings, there is illustrated first the inflatable bladder 10 of the present invention which, in a preferred embodiment, is cylindrically shaped polyurethane film 11 which is 0.18 mm thick. The flexible bladder measures 15.0 cm along its longitudinal axis and 3.0 cm in width and is capable of inflation to a volume of 35 cc. Enclosed interiorly of the bladder 10 are elongated polyurethane filaments 12 which are disposed parallel to the longitudinal axis of the bladder 10. These filaments prevent the inner walls of the bladder from closing together in response to the surrounding blood pressure during deflation of the bladder and thus gas will not be trapped interiorly of the bladder during bladder deflation.
Each end of the bladder includes a tab 13, 14 for suturing the bladder in place with tab 13 being a longitudinal protrusion at the distal end of the bladder and tab 14 being a transverse member at the front end. At the front end of the bladder there is a hollow flexible tube 15 which, in a preferred embodiment, is made of polyurethane reinforced with stainless steel wire. The tube 15 is wrapped with Dacron velour 16 and defines a fluid flow path to the interior of the bladder.
The envelope 20 into which the bladder is removably inserted is fabricated of a Dacron velour. The surface 21 which becomes the blood interface, i.e., the surface which faces the interior or lumen of the descending thoracic aorta is backed with a conductive polyurethane. This promotes the growth of a pseudointima and also provides a low potential for thromboembolism.
The other surface 22 of the envelope, i.e., the surface which faces the thoracic cavity, is also Dacron velour and is cross stitched as at 23. This prevents the surface 22 of the envelope from stretching and thus limits and directs the inflation of the bladder inwardly toward the lumen of the thoracic aorta.
To implant the aortic patch, the descending thoracic aorta 30 is incised along its longitudinal axis preferably starting just below the origin of the subclavian artery. The envelope 20 is sutured to the walls of the incision as at 31 with the surface 21 of the envelope joined to the intima of the vessel in an air tight relationship. The bladder is inserted in the envelope and the tabs 13, 14 sutured in place as at 32.
The supply tube 15 is connected to a valve 34 which is coupled to a source of fluid 35 preferably compressed gas.
In order to activate the patch, a driving unit 36 is utilized. The driving unit controls the application of the compressed gas to inflate and deflate the bladder. Specifically, electrodes are sutured into the myocardium at the time of surgery and the "R" wave of the electrocardiograph triggers the drive unit which provides gas at a pressure of 2-- 3 psi to inflate the bladder to a volume of 35 cc.
As illustrated in FIGS. 3 and 5, the cross stitching 23 limits the ability of the bladder to inflate toward the thoracic cavity and substantially limits and directs the inflation of the bladder inwardly of the thoracic aorta 30. Furthermore, the filaments 12 prevent collapse of the patch and entrapment of gas therein, in response to pressure of the blood against surface 21 of the envelope.
In operation, the use of the "R" wave from the electrocardiograph activates the valve which operates to contract the patch out of phase with the physiologic left ventricle, decreasing systolic heart pressure, and thus reducing the work of the left ventricle. Aortic pressure is increased during diastole, again out of phase, providing normal peripheral perfusion and increasing mean arterial flow. This is called counter pulsation and is well known.
When the dynamic aortic patch is inactive, there is no interference with the physiologic flow of blood through the arterial tree and peripheral circulation.
If the bladder of the present invention should require replacement, it is only necessary to open the upper facing 22 of the envelope 20, remove the bladder 10 and insert a new bladder. To accomplish this, since the lower surface 21 of the envelope remains intimately in contact with the walls of the thoracic aorta, extracorporeal bypass is not necessary. Similarly, since the entire lower surface 21 of the envelope 20 is sutured to the vessel before the bladder is inserted, there is minimal risk of puncturing the bladder. This permits not only quicker, easier, safer initial implantation of the apparatus, but also permits faster replacement of the bladder since only the bladder component is replaced.
The foregoing is a description of the preferred embodiment of the improved dynamic aortic patch of the present invention. It must be appreciated that many changes and modifications can be made without departing from the spirit of the present invention. The invention, therefore, should be limited only by the following claims. | An improved dynamic aortic patch is surgically implanted in the thoracic aorta and is systematically inflated and deflated to generate pressure waves in the bloodstream. The pressure waves assist the heart by augmenting the circulation of the blood through the body. The patch includes a flexible inflatable bladder and an independent envelope. The envelope has a reinforced surface for limiting and directing inflation of the bladder inwardly toward the lumen of the aorta. | 0 |
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to novel molding methods for the manufacture of thin thermoplastic lenses and is particularly adaptable for the manufacture of minus ophthalmic lenses that have thickness of about 1 mm or less.
REFERENCES
The following patents are cited in this application as superscript numbers:
1. Johnson, et al., “Compressor Unit” U.S. Pat. No. 2,443,286, issued Jun. 22, 1948
2. Weber, “Apparatus for Injection Molding Lenses”, U.S. Pat. No. 4,008,031, issued Feb. 15, 1977
3. Weber, “Method for Injection Molding Lenses”, U.S. Pat. No. 4,091,057, issued May 23, 1978
4. Laliberte, “Method for Molding Ophthalmic Lenses”, U.S. Pat. No. 4,364,878, issued Dec. 21, 1982
All of the above patents are herein incorporated by reference in their entirety to the same extent as if each individual patent was specifically and individually indicated to be incorporated by reference in its entirety.
2. State of the Art
Lenses are used for a variety of purposes, for example in optical devices such as microscopes and eye glasses. Over the past few years, the use of thermoplastic material to prepare ophthalmic lenses for such uses as in vision corrective and in prescriptive (R x ) spectacle lenses as opposed to traditional glass lenses has increased dramatically because thermoplastic lenses offer several advantages over glass. For example, plastic is lighter than glass and hence spectacles with plastic lens are more comfortable to wear especially since the nominal lens thickness is typically 2.0-2.2 mm. Other factors for increased demand for thermoplastic lenses are that these lenses can be made scratch and abrasion resistant, they come in a wide range of fashionable colors, and because the production techniques have improved so that they can now be manufactured at higher rates and in a more automated fashion.
Of the thermoplastic lenses, the use of polycarbonate thermoplastic is becoming very attractive as compared to, for example, lenses made from individual casting and thermoset-peroxide curing allylic resins. Factors favoring polycarbonate thermoplastic lenses include lower density and higher refractive index than cast-thermoset plastic. Hence, thinner lenses in the range of 1.5-2.0 mm thickness can be made. In addition, polycarbonate lenses of the same nominal thickness as thermoset-peroxide cured allylic resins will be of lighter weight, due to lower density, and therefore will impart greater wearer comfort. Furthermore, polycarbonate thermoplastic lenses have far greater impact and breakage resistance than any other optical grade polymeric material.
Heretofore, thermoplastic, injection-molded lenses have been manufactured by injection molding with or without any compression. Injection molding without any compression typically involves the use of a mold cavity having fixed surfaces throughout the molding cycle. Such molding processes employ very long molding cycles, high mold-surface temperatures, higher than average plastication and melt temperatures for that given resin, and slow controlled fill rates followed by very high packing pressures which are held until gate freeze-off is complete.
Fixed cavity processes of the type described above, employ larger than normal gating and runner systems to permit maximum packing pressure and delivered material before gate freeze-off occurs, at which time no further transfer of molten polymer occurs between the runner system or plasticating unit and the cavity. Gate freeze-off in a fixed cavity injection machine presents a problem, given that powered lenses have differing front and back radii of curvature, prescription lenses must therefore have differing cross-sectional thicknesses which in turn leads to non-uniform shrinkage during part formation in the mold cavity and cooling-down which can cause poor optics and/or distortion. In addition, the thickest sections of the lens are subject to slight sink marks or depressions which in turn cause a break in the otherwise uniform radius of curvature of the lens surface. This break results in a localized aberration or deviation in the light bending character of the lens at that area of sink.
Thus, although great care is taken to see that the injected polymer mass conforms perfectly to the fixed lens mold cavity surface, contour, and dimensions, once gate freeze-off prevents additional packing pressure and material transfer, differential shrinkage begins to occur within the polymer melt and the polymer skin begins to pull away from the mold surfaces accordingly. This pre-release detrimentally affects optical quality since the molded lens contour and surface no longer can be forced by intimate contact to exactly replicate the precision optical mold surfaces and cure contours. Also, a fixed cavity molding process is limited in how thin the lens center can be. Below about 2 mm, the molten plastic preferentially flows around the thick edge leaving a void and/or knit line which extends into the central zone of the to-be-formed lens.
To address these problems with fixed cavity molding processes, compression molding techniques have been used. The injection/compression molding techniques are divided into two types (i) the clamp-end injection/compression and (ii) the auxiliary component injection/compression. In the clamp-end injection/compression method, the molten polymer is injected into a mold space formed by moving the mold platens and mold halves to a predetermined position. After or during injection, the molten polymer mass is allowed to cool for a predetermined time interval and the injection molding machine commences a closing motion of the movable platen. This clamping-up motion compensates for shrinkage occurring during freezing of the molten polymer. Under this clamp-induced compressive force, the mold cavity's contents continue cooling and solidifying, eventually reaching a temperature sufficiently below the glass-transition temperature, or freezing point, of the injected polymer that the molded article may be safely ejected without risking optical distortion. However, in view of the high clamp pressure, thin centered lenses cannot be used in this process due to crushing of the frozen center portion while the remaining areas of the mold retain molten polymer.
This method however, has severe limitations. First, it is critical to carefully control the injection pressure and fill rate, along with the timing interval. For example, the injected melt must be allowed to form a surface skin and partially solidify to prevent molten polymer from spilling outside the desired runner-mold-cavity configurations, necessitating costly and laborious trimming operations on the molded part. Second, if the melt solidifies to too great an extent, compression at ultimate clamping pressures can cause hobbing or deformation of the mating plats at the parting line, thus damaging the mold set. Third, if compression is delayed too long, too much polymer solidification will have occurred when the compressive force through final clamp-up is initiated, resulting in forceable reorientation of the polymer and cold working of the plastic, which, in turn, produces birefringence and undesirable molded-in stress levels, with resulting localized nonuniform light-bending characteristics.
In the auxiliary component injection/compression method the compressive pressure is applied to the opposing optical surfaces via auxiliary springs, cylinders or the like which are either internal to the mold itself or as peripheral apparatus thereto. Early thermoplastic lens molding of this type employed simple spring-loaded, movable optical dies within the mold set 1 . Such apparatus created a variable volume lens mold cavity thereby, but relied upon high internal polymer melt pressure to spread the movable dies against the resisting spring pressure. In order to apply sufficiently great compressive forces upon the solidifying mold contents, these spring forces were great. However, the greater the spring force, the greater the injection pressure that must be used to compress the springs during variable cavity fill. The greater the injection pressure required, the greater the degree of molded-in stresses and optically unsatisfactory birefringence. The greater the optical power for the molded lens, the greater the dissimilarity between the front and back curves and thus the greater the cross-sectional thickness variation. Therefore, this process is limited to production of weakly powered lenses with minimal diameter and minimal thickness variations.
Another auxiliary component process is represented by Weber 2,3 . Weber teaches a variable-volume cavity formed by injection-melt, pressure induced rearward deflection of at least one movable male or female die which after a certain interval is followed by forward displacement resulting in compression under the driving force of an auxiliary hydraulic cylinder mounted in one-to-one relationship with this movable die. Flow ports are provided through which excess polymer melt is forcibly extruded from the lens cavity under the compressive forces. Weber too relies upon a preset amount of time to elapse between completion of injection fill and commencing compressive pressure. Therefore, this process too suffers from defects caused by premature compression or excessively delayed compression discussed above. Additionally, this process can produce lenses of inconsistent thickness.
Another auxiliary component process is described by Laliberte 4 . This process includes a movable die coupled to an auxiliary hydraulic cylinder. After the mold is closed under clamp pressure, the mating die parts are spread apart by injection of a polymer. A fixed amount of polymer, adequate to fill the fully compressed mold-cavity system is then injected. This process permits greater control of nominal lens thickness and therefore eliminates material scrap waste and trimming operations. However, Laliberte discloses lens thickness control but only with regard to nominal 3.0 mm center thickness which is significantly greater than the desired consumer lens thickness.
Another major short-coming of the injection/compression molding processes described above is that they are unsuitable for manufacturing R x lenses, especially minus thermoplastic lenses having a center thickness of about 1 mm or less and having edge thicknesses greater than the center thickness. This is because the injected thermoplastic melt in the thinner center portion of the minus lens freezes prior to the freezing of the melt in the thicker edge portions. As a result, the compressive pressures generated by the mold halves (optical inserts) at this point of solidification is focused only on the frozen center portion which crushes or otherwise distorts this part of the lens. Such crushing or distorting of the frozen center is particularly problematic at center thicknesses of about 1 mm or less and having molten edge thicknesses substantially larger since the entire compressive force is concentrated on a small diameter, thin column of frozen material at the center. Also, this force exceeds the compressive strength of the solidified material. However, as is apparent, thin centered minus lenses having a thickness of about 1 mm or less are particularly desirable as having still further reduction in weight as compared to conventional minus lenses having a center thickness greater than about 1 mm (e.g., 1.5 mm).
In view of the inability of injection/compression molding processes to prepare thin centered minus lenses, such lenses have been manufactured by abrading and polishing thicker lenses. Such manufacturing techniques employ abrading and polishing elements such as optical curve generating, fining and polishing machines which inevitably leave abrasion/polishing residues on the lens surface and/or leave negative fining marks below the nominal surface.
SUMMARY OF THE INVENTION
This invention is directed to novel molding methods for manufacturing thin thermoplastic lenses, in particular minus lenses having a center portion of about 1 mm or less. In one embodiment, the methods of this invention provide for thin thermoplastic minus lenses that lack any abrasion or polishing artifacts on the surface thereof and also lack any negative fining marks below the nominal surface.
In particular, this invention relates to the molding methods for the preparation of thin lenses which initially involve compression of the lens mold halves prior to freezing of the thermoplastic melt. Subsequently, the mold halves are maintained in place while pressure is increased on the thermoplastic melt to compensate for the shrinkage which occurs during solidification of the melt in the mold. Subsequent cooling of the mold results in formation of the lens.
The methods of this invention are particularly advantageous in that a mold process is employed wherein crushing of the thin lens by the molds during manufacture is avoided.
Accordingly, in one of its method aspects, this invention is directed to a method for manufacturing a thermoplastic lens which comprises:
(a) providing a mold comprising a male mold half and a female mold half wherein said mold halves, when closed, define a mold cavity in the shape of a lens;
(b) introducing into the mold cavity a molten thermoplastic material in a quantity at least sufficient to form a lens;
(c) moving at least one of said male and female mold halves to a pre-determined position prior to freezing of the thermoplastic material at the thinnest point of the to-be-formed lens;
(d) maintaining said mold halves in a stationary position while increasing pressure in the mold cavity; and
(e) permitting the thermoplastic material to freeze thereby forming the thermoplastic lens.
In one embodiment, the increase in mold pressure in the mold cavity is achieved by injection of further melted thermoplastic resin into the mold. In another embodiment, this increase in internal cavity pressure is achieved by an injector, or by use of one or more screws, secondary pistons, pins, or other mechanisms.
In a second of its method aspects, this invention provides a method for manufacturing a thermoplastic lens which comprises:
(a) providing a mold comprising a male and female mold halves wherein said mold halves, when closed, define a mold cavity in the shape of a thermoplastic lens;
(b) introducing into the mold cavity a molten thermoplastic polycarbonate material in a quantity at least sufficient to form the lens wherein said thermoplastic polycarbonate material is maintained at a temperature above about 575° F. which permits the material to flow;
(c) moving at least one of said male and female mold halves to a pre-determined position wherein the mold cavity has a center thickness of about 1 mm or less prior to freezing of the thermoplastic material at the thinnest point of the to-be-formed lens;
(d) maintaining said mold halves in a stationary position while increasing pressure in the mold cavity by use of an injector or injectors to maintain a constant volume within the mold; and
(e) permitting the thermoplastic material to freeze thereby forming the thermoplastic ophthalmic lens.
In one of its article of manufacture aspects, this invention relates to a thermoplastic lens configured to have a minus correction which lens has a minimal thickness of about 1 mm or less wherein said lens is free of abrasion or polishing artifacts on the surface thereof and lacks negative fining marks below its nominal surface.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in greater detail with reference to the preferred embodiments illustrated in the accompanying drawings, in which like elements bear like reference numerals, and wherein:
FIG. 1 is a flow diagram illustrating the methods of the present invention;
FIG. 2 is a schematic side view of a mold in a starting position;
FIG. 3 is a schematic side view of the mold of FIG. 2 in a filling position;
FIG. 4 is a schematic side view of the mold of FIG. 2 during filling;
FIG. 5 is a schematic side view of the mold of FIG. 2 during pressing; and
FIG. 6 is a schematic side view of the mold of FIG. 2 in a final cooling position.
DETAILED DESCRIPTION OF THE INVENTION
As noted above, this invention relates to novel molding methods for the manufacture of thin thermoplastic lenses, as well as to novel thin thermoplastic lenses. However, prior to describing this invention in further detail, the following terms will first be defined.
Definitions
As used herein, the following terms have the following meanings.
“Molten thermoplastic polymer” or “melt” refers to the softened physical state of an amorphous or crystalline thermoplastic polymer which permits the polymer to flow. Preferably, the molten thermoplastic material flows under such pressure when it is heated above its glass transition (T g ) or melting temperature (T m ), respectively.
“Freeze” or “freezing” refers to cooling a molten thermoplastic polymer to a temperature wherein it no longer flows.
“Flows” or “flowable” refers to the ability of a molten thermoplastic polymer to flow at a flow rate of at least 3 mfi (melt flow index) as determined by ASTM Test No. D1238 which measures the flow rate or melt index by extrusion plastometer.
“Thermoplastic” refers to polymers which are capable of reversibly softening or fusing when heated and hardening when cooled. Suitable thermoplastic materials are well known in the art and include, by way of example, polycarbonates, diethylene glycol bis(allylcarbonate), acrylics, polyurethane and other high index materials. Preferably, the thermoplastic material is polycarbonate.
“Stationary position” refers to a mold position wherein the mold halves are substantially fixed in space and each mold half does not move more than about ±0.05 mm. Preferably there is no movement when the mold halves are in the stationary position. While force may be necessary to maintain the stationary position of the mold halves, additional force is not applied to bring the mold halves into closer proximity.
Methodology
The methods of this invention are directed to a molding processes for the preparation of thermoplastic lenses. These methods employ a conventional mold comprising a male mold half and a female mold half wherein said mold halves, when closed, define a mold cavity in the shape of a lens. Any conventional molds can be used and are well known in the art.
The methods of the invention allow the manufacture of thin thermoplastic lenses having a thickness of about 1 mm or less at a thinnest portion without crushing or distorting the thin part of the lens. These thin lenses are achieved by fixing the mold halves after injection of thermoplastic and applying an expansive pressure to compensate for shrinkage of the thermoplastic during cooling.
In the methods of this invention, the mold cavity is formed by closing the male and female mold halves. Initially, the mold is closed to a position where a distance between the mold halves is greater than a final desired lens thickness. The closing process may entail movement of at least one or both of the mold halves to precisely define an enlarged mold cavity. Then, molten thermoplastic material, preferably heated above its T g is injected into the mold cavity. In a preferred embodiment, an injector for delivering the thermoplastic to the mold employs a short/hot runner to ensure that the thermoplastic material remains in a molten form during the injection process. In an alternative preferred embodiment, the thermoplastic material may be delivered via a heated injection port or, still further, a combination of a short/hot runner and a heated injection port can be used.
In another preferred embodiment, the mold halves are heated, preferably above the T g of the thermoplastic material during the injection process to ensure against premature freezing of the polymer melt. More preferably, the mold halves are heated to a temperature of above about 275° F. and even more preferably to a temperature of about 290° F. to about 340° F.
At least a sufficient amount of molten thermoplastic material is then added to the mold cavity to form the lens. In some cases, a slight excess of molten material may be added in order to ensure complete filling of the cavity. Obviously, the specific amount of such material employed corresponds to the dimensions of the to-be-formed lens which is readily ascertainable by the skilled artisan.
Subsequently, at least one of the male and female mold halves is moved toward the other mold half to compress the thermoplastic material and generate contractive pressure within the mold cavity while maintaining the polymer therein in the molten state. The closing of the mold halves continues until a hard stop point between the mold halves is reached. The distance between the male and female mold halves at this hard stop point corresponds to the desired thickness of the to-be-formed lens which is preferably about 1 mm or less, more preferably from about 0.5 mm to 1 mm, and even more preferably from about 0.7 mm to 1 mm. Again, during compression, the thermoplastic material within the mold cavity is maintained in a molten state, including the material at the thinnest point of the to-be-formed lens, when this hard stop point is reached.
At this point, the mold halves are then maintained in a stationary position while increasing pressure within the mold cavity in order to compensate for thermoplastic shrinkage in the mold cavity during freezing thereby maintaining conformity of the thermoplastic material to the mold. The increase in cavity pressure is preferably achieved by expansive pressure. In one preferred embodiment, expansive pressure is created within the cavity by use of one or more injectors which injects additional molten thermoplastic material into the mold cavity as needed. As before, the injector(s) and/or injector port(s) can optionally be heated to ensure that the additional thermoplastic injected material remains in a molten form. The expansive pressure is preferably applied until freezing is complete or substantially complete.
In another preferred embodiment, expansive pressure is created within the mold cavity by use of one or more screws, secondary pistons, pins, flexible compression rings, bellows, or the like. These screws, pins, or pistons, apply a force to the thermoplastic material during freezing to compensate for shrinkage. The force is preferably applied inwardly from the sides of the mold cavity or substantially perpendicular to the direction of mold opening and closing.
Once such expansive force is established within the mold cavity, the thermoplastic material is cooled and, upon freezing, a suitable lens is formed. In one preferred embodiment, cooling and subsequent freezing of the thermoplastic material is achieved by cooling of the molds. As discussed above, the use of expansive force at this point in the manufacturing process inhibits crushing at the thinnest point of the lens which freezes first.
FIG. 1 is a flow diagram illustrating the method according to one embodiment of this invention. FIGS. 2-6 illustrate the steps of the method according to the present invention as it is performed with one exemplary mold system.
The process for forming a thermoplastic lens according to one embodiment of the present invention begins at step 100 with the mold halves in an open position to remove the previously formed part and with the injector filled with a thermoplastic material. In step 200 the mold is closed to a predetermined position in which the mold halves are separated by a space which is greater than the size of the final to be formed lens. During or after mold closing, the mold is preferably heated in a preheating step 300 . In addition to or as an alternative to preheating the mold, the injector may be heated. During or after preheating in step 400 , the thermoplastic material injector is moved forward so that the injector contacts a fill port of the mold in preparation for the injection of the thermoplastic material. In step 500 , the thermoplastic material is injected at a high pressure. Following injection of the thermoplastic material, step 600 involves part press or coining in which the mold halves are moved towards each other to a final part thickness. In step 700 , expansive pressure is applied to the thermoplastic material within the mold. As described above, this expansive pressure may be applied in a variety of ways. For example, expansive pressure may be applied by injection of addition thermoplastic material during cooling. Finally in step 800 , final cooling of the part, opening of the mold, and part removal are performed. Once the part has been removed the process returns to step 100 for formation of another part.
FIG. 2 illustrates a mold 10 in a starting position in which the mold halves are in an open position. The mold 10 includes an upper mold cavity half 12 which is fixed to a bolster plate 14 . The upper mold cavity half 12 has an upper mold member 16 which is also fixed to the bolster plate 14 . Alternatively, the upper mold member 16 may be movable within the upper mold cavity half 12 . The mold 10 also includes a lower mold cavity half 18 with a movable lower mold member 20 . The lower mold cavity half 18 is connected by a plurality of connecting rods 22 to a hydraulic cylinder 24 which is positioned above the upper mold cavity half 12 . The connecting rods 22 extend through the upper mold cavity half 12 to move the lower mold cavity half 18 with respect to the upper mold cavity half. The lower mold member 20 is movable within the lower mold cavity half 18 by a second hydraulic cylinder 26 positioned below the lower mold member. In the starting position illustrated in FIG. 2, both the lower mold cavity half 18 and the lower mold member 20 are lowered to allow the prior part 30 to be removed from the mold 10 .
The mold 10 is also provided with an injection unit or injector 32 having a barrel 40 used to melt thermoplastic pellets to prepare the thermoplastic material 42 for injection into the mold cavity. The upper and lower mold members 16 , 20 are preferably heated by passing heated fluid through channels in the mold members. In another preferred embodiment, electric heat can be generated by electric cartridge heaters thermally coupled to the mold inserts optionally containing heated fluid channels. The heating of the mold members 16 , 20 allows the thermoplastic material 42 to be injected completely before the material begins to cool.
FIG. 3 illustrates the mold 10 in a closed position in preparation for filling the mold cavity with thermoplastic material 42 . As shown in FIG. 3, the lower mold cavity half 18 and lower mold member 20 are moved to the closed position by the upper hydraulic cylinder 24 . The closing of the lower mold cavity half 18 against the upper mold cavity half 12 closes the parting line 46 of the mold. In the position illustrated in FIG. 3, a distance between the upper mold member 16 and the lower mold member 20 is greater than the final desired part thickness. Preferably, the distance between the mold halves is approximately 1 to 5 mm greater than the final part thickness. FIG. 3 also illustrates the injector 32 moved against the fill port 34 of the mold cavity 44 in preparation for filling of the mold. At this time, the mold is in the ready position illustrated in FIG. 3 and the mold and/or the injector unit 32 have been preheated to ensure that the thermoplastic material 42 remains in a molten form during the injection process.
FIG. 4 illustrates the mold 10 during injection of the molten thermoplastic material 42 into the mold cavity 44 . During injection, the space between the upper mold member 16 and the lower mold member 20 is preferably maintained at a distance which is larger than the final part thickness. Preferably, the mold halves are held stationary during the mold cavity filling or injection step. The injector 32 may be operated by advancing a screw 48 within the barrel 40 . Mold cavity filling is performed at a high pressure F 1 , such as 10,000 psi to 20,000 psi.
FIG. 5 illustrates the part-press step in which the mold halves 16 , 20 are moved toward each other after the molten thermoplastic material 42 has been introduced into the mold cavity 44 . In the mold illustrated in FIGS. 2-6 the pressing process is performed by activating the lower hydraulic cylinder 26 to move the lower mold member 20 towards the upper mold member 16 . The process is complete when the two mold halves are in their final position and a distance between the upper and lower mold members 16 , 20 is substantially the desired thickness of the final lens. In the mold illustrated in FIG. 5, the end of the pressing process or the bottom out point is determined by physically limiting the stroke of the lower hydraulic cylinder 26 . Preferably, during the pressing process the injector 32 is optionally shut off so that no additional thermoplastic material 42 is injected. In another optional embodiment, some of the thermoplastic material 42 may be pushed back into the injector 32 . Once the pressing process is finished the mold halves 16 , 20 are held stationary. After the process, cooling air begins to be injected into the mold for cooling of the part. The cooling air is injected through the channels 36 in the upper and lower mold cavity halves 12 , 18 . Although cooling with cooling air or other fluid is preferred, cooling by natural convection may also be used.
The final holding and cooling position of the mold 10 is illustrated in FIG. 6 . In this position, expansive pressure is applied to the thermoplastic material 42 in the mold cavity 44 to compensate for shrinkage of the part during cooling. The expansive pressure is applied, in the embodiment illustrated in FIGS. 2-6, by injecting additional thermoplastic material 42 at a low injection force with the injector 32 as the part solidifies. The upper and lower mold members 16 , 20 are maintained stationary during the application of the expansive pressure. The injection pressures of the injector 32 during the application of expansive pressure are preferably low pressures, such as about 3000 psi to 7000 psi. After a predetermined cooling period the application of the expansive pressure is turned off by turning off the injector 32 , final cooling occurs, and the mold is opened for part removal.
While the invention has been has been described in detail with reference to the preferred embodiments thereof, it will be apparent to one skilled in the art that various changes and modification can be made and equivalents employed, without departing from the present invention. | Disclosed are novel molding methods for manufacturing thin thermoplastic lenses and, in particular, minus ophthalmic lenses that have thickness of about 1 mm or less at the thinnest point thereof. The molding methods disclosed provide for lenses which lack any abrasion or polishing artifacts on the surface and also lack any negative fining marks below the nominal surface. | 1 |
FIELD OF THE INVENTION
This invention relates to a system and methods for interventional medicine, and more specifically to computer assisted navigation and imaging of medical devices within a subject body.
BACKGROUND OF THE INVENTION
Interventional medicine is the collection of medical procedures in which access to the site of treatment is made through one of the subject's blood vessels, body cavities or lumens. For example, angioplasty of a coronary artery is most often performed using a catheter which enters the patient's arterial system through a puncture of the femoral artery in the groin area. Other interventional medical procedures include the assessment and treatment of tissues on the inner surface of the heart (endocardial surfaces) accessed via peripheral veins or arteries, treatment of vascular defects such as cerebral aneurysms, removal of embolic clots and debris from vessels, treatment of tumors via vascular access, endoscopy of the intestinal tract, etc.
Interventional medicine technologies have been applied to manipulation of instruments which contact tissues during surgical procedures, making these procedures more precise, repeatable and less dependent of the device manipulation skills of the physician. Some presently available interventional medical systems for directing the distal tip of a medical device from the proximal end of the medical device use computer-assisted navigation and a display means for providing a visual display of the medical device along with anatomical images obtained from a separate imaging apparatus. Such systems can provide a visual display of blood vessels and tissues, obtained from a Fluoroscopy (X-ray) imaging system for example, and can display a projection of the medical device being navigated to a target destination using a computer that controls the orientation of the distal tip of the medical device.
In some cases, it may be difficult for a physician to become oriented in a three dimensional setting using a display of a single-plane X-ray image projection. Enhancement or augmentation of the single-plane X-ray image may be required to aid the physician in visualizing the orientation of the medical device and blood vessels. A method is therefore desired for enhancing a display image of the anatomical surfaces and the orientation of a medical device in real time to improve navigation through the blood vessels and tissues.
SUMMARY OF THE INVENTION
According to the principles of the present invention, a system and method are provided for control of a navigation system for deploying a medical device within a subject, and for enhancement of a display image of anatomical features for viewing the current location and orientation of a medical device moving through the subject body. The display of the X-ray imaging system information is augmented in a manner such that a physician can more easily become oriented in three dimensions with the use of a single-plane X-ray display. A typical X-ray imaging system comprises a source for emitting a beam through a three dimensional space and onto a plane, where a point within a subject body in the three dimensional space is projected onto the plane. The projection of a point within the subject body onto the imaging plane can be obtained using an orthographic projection matrix derived from the point-to-image plane distance and the source-to-image plane distance. Thus, a point location within the subject body having known coordinates, properly registered to the frame of reference of the X-ray system, can be projected onto the X-ray image plane of the live X-ray image in the same manner.
In accordance with one aspect of the invention, a method of projection can be used to graphically overlay a representation of the actual medical device location and orientation onto the X-ray image. One or more desired target points within the subject can also be projected onto the X-ray image, as well as one or more reference markers on the subject to track patient movement. A graphical representation of a virtual medical device can be overlaid to show a visual reference of a predicted new location and orientation of the actual medical device that corresponds to a desired navigational configuration. A mathematical model of the medical device can be used to define the configuration of the virtual medical device, which can model the behavior of the device corresponding to a change in navigation control variables to predict deflection and rotation of the medical device. A desired direction for steering the medical device within the plane of the X-ray image can be graphically represented, and surface shapes within the subject may also be rendered and graphically represented on the X-ray image display. All the graphically overlaid information is also updated in real time as the X-ray imaging system is rotated or moved, to augment the image display and enhance visualization of the orientation of a medical device in a three dimensional space using a single-plane X-ray image displayed on the control system.
It is thus an object of the invention to provide a system and method for augmenting the displayed anatomical image of a subject with graphically overlaid objects to provide enhanced visualization of medical devices, anatomical locations, shapes, markers, and other objects and annotations in a three dimensional space for aiding in the orientation and navigation of the medical device through the subject body.
It is a further object of the invention to provide a system and method for enabling virtual representation of the medical device, for providing a visual reference of a predicted orientation and location of the medical device corresponding to a desired configuration or movement to a desired target.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of an automated system for navigating a medical device through the lumens and cavities in the operating regions in a patient in accordance with the principles of this invention;
FIG. 2 is an illustration of the projection geometry for projecting a location point onto an imaging plane in accordance with the principles of the present invention;
FIG. 3 is an illustration of an anatomical image display comprising images of the actual medical device, graphically overlaid images of a virtual medical device configuration and a series of target locations according to the principles of the present invention;
FIG. 4A is a schematic diagram of a navigation system and imaging system combination, in which the navigation system determines the where objects in the operating region should appear based upon information from the imaging system;
FIG. 4B is a schematic diagram of a navigation system and imaging system combination, in which the imaging system determines where objects in the operating region should appear based upon position information from the navigation system;
FIG. 5 is a view of the screen of a magnetic navigation system, with imported images from an imaging system in accordance with the principles of this invention;
FIG. 6A is an x-ray image of an anatomic model of a human heart along an axis 26° on the LAO side, showing objects overlaid on the image in accordance with the principles of operation;
FIG. 6B is an x-ray image of the anatomic model of the human heart along an axis 26° on the RAO side;
FIG. 7A is an x-ray image of an anatomic model of a human heart along an axis 25° on the LAO side, showing objects overlaid on the image in accordance with the principles of operation;
FIG. 7B is an x-ray image of the anatomic model of the human heart along an axis 27° on the RAO side;
FIG. 8A is an x-ray image of an anatomic model of a human heart along an axis 25° on the LAO side, showing objects overlaid on the image in accordance with the principles of operation;
FIG. 8B is an x-ray image of the anatomic model of the human heart along an axis 8° on the RAO side;
FIG. 8C is an x-ray image of the anatomic model of the human heart along an axis 27° on the RAO side;
FIG. 9A is an x-ray image of an anatomic model of a human heart along an axis 25° on the LAO side, showing objects overlaid on the image in accordance with the principles of operation;
FIG. 9B is an x-ray image of an anatomic model of a human heart along an axis 16° on the LAO side;
FIG. 9C is an x-ray image of an anatomic model of a human heart along an axis 6° on the LAO side;
FIG. 9D is an x-ray image of an anatomic model of a human heart along an axis 17° on the RAO side;
FIG. 9E is an x-ray image of an anatomic model of a human heart along an axis 27° on the RAO side.
DETAILED DESCRIPTION OF THE INVENTION
An automated system for navigating a medical device through the lumens and cavities in an operating region in a patient in accordance with the principles of this invention is indicated generally as 20 in FIG. 1 . The system 20 comprises an elongate medical device 22 , having a proximal end and a distal end adapted to be introduced into the operating region in a subject. The system 20 also comprises an imaging system 30 for displaying an image of the operating region on a display 32 , including a representation of the distal end of the medical device 22 in the operating region.
The system also includes a navigation system for manipulating the distal end of the medical device 22 . In this preferred embodiment the navigating system is a magnetic navigation system 50 . Of course, the navigation system could alternatively be a piezoelectric or electrostrictive system or a mechanical control system with pull wires or servo motors, or other suitable system for orienting the distal tip of the medical device. The magnetic navigation system 50 orients the distal end of the medical device 22 in a selected direction through the interaction of magnetic fields associated with the medical device 22 inside the operating region and at least one external source magnet outside the subject's body. The catheter may then be advanced in the selected direction, to reach the target destination through the successive reorientation stepwise process and advancement.
A preferred embodiment of the present invention describes a method for a navigation system associated with an elongate flexible catheter or medical device and an X-ray imaging system, for providing a suitable projection of a graphic overlay of the medical device and target locations within the subject body. The control or actuation means used to steer or navigate the medical device with a computer controlled navigation system may be any of a variety of method known to those skilled in the art, such as mechanical, magnetic, electrostrictive, hydraulic, or others. One preferred embodiment is one where an externally applied magnetic field is used to steer the device, while device advancement and retraction is mechanically driven. Such a navigation system is typically used in conjunction with an X-ray system such as a Fluoroscopy Imaging system, with a mutually known registration between the systems. Other anatomical features such as curves, ridge lines, ablation lines, surface portions, landmark locations, marker locations as reference, and so on, possibly including data from preoperative or intraoperative three dimensional images, can be overlaid on the live X-ray display. Past device configurations can also be displayed as a reference so that any changes in configuration such as patient shift can be monitored during the course of the procedure.
Likewise reconstructed features such as blood vessels reconstructed from contrast agent injection and subsequent imaging and image processing, or other path reconstructions as defined by a user to produce a three dimensional path could be overlaid on the live X-ray display.
A typical X-ray imaging system comprises a source for emitting a beam through a three dimensional space and onto an imaging plane, where a point within a subject body in the three dimensional space is projected onto the plane. In a preferred embodiment, the X-ray imaging system is preferably a Fluoroscopy imaging system capable of providing images on at least two separate planes, which together can provide the three dimensional coordinates for a location displayed in the two separate planes. FIG. 2 shows a geometric illustration of an X-ray source point of origin 60 for emitting a beam towards the subject and the imaging plane 62 . The projection of {right arrow over (x)}, a point 64 in a three dimensional space, onto the imaging plane 62 as a perspective projection {right arrow over (x)} p , can be obtained using an orthographic projection matrix. The orthographic projection matrix can be derived from h the point-to-image plane distance 72 , and d the source-to-image plane distance 70 , or distance to the center {right arrow over (x)} c of the plane 62 . A vector {right arrow over (q)} from a point in space {right arrow over (x)} to the center of the plane {right arrow over (x)} c may be defined as {right arrow over (q)}=({right arrow over (x)}−{right arrow over (x)} c ):. The source-to-image distance 70 is defined as d. The orthographic projection of {right arrow over (q)} onto the imaging plane 72 is:
{right arrow over (y)} =( I−nn T ) {right arrow over (q)} or
{right arrow over (y)}=A{right arrow over (q)}=A ( {right arrow over (x)}−{right arrow over (x)} c )
where nn T is the 3×3 outer product constructed from the normal {right arrow over (n)} to the X-ray image plane, I is the 3×3 identity matrix, and (I−nn T ) is the orthographic projection matrix. From FIG. 2 , it can be seen that:
x → P - x → C d = y → ( d - h ) , where h = ( q → · n → ) ( 1 ) Since ( x → P - x → C ) = x → P - x → C · y → y → , ( 2 )
Equation (1) may be rewritten as:
( x → P - x → C ) = ⅆ ( ⅆ - h ) y → = ⅆ ( ⅆ - n → · ( x → - x → C ) ) A ( x → P - x → C ) ( 3 )
Equation (3) above defines the perspective projection {right arrow over (x)} p of point {right arrow over (x)} onto the imaging plane, so {right arrow over (x)} p may be rewritten in the form:
x
→
P
=
x
→
C
+
ⅆ
(
ⅆ
-
n
→
·
(
x
→
-
x
→
C
)
)
A
(
x
→
P
-
x
→
C
)
(
4
)
For any given point {right arrow over (x)} in a three dimensional space, a corresponding perspective projection point {right arrow over (x)} p on the X-ray image plane can be determined using equation (4) above. Thus, for any point location within the imaging volume, a corresponding graphic overlay object may be suitably projected onto the X-ray image display. Such graphic overlay objects that may be suitably projected onto a display as illustrated in FIG. 3 may include objects such as the actual medical device 100 and target locations 102 , 104 , 106 and 108 within the operating region of the subject. Other objects that can be usefully overlaid on the live X-ray display include anatomical features such as curves, ridge lines, ablation lines, surface portions, landmark locations, marker locations used as reference, and so on, possibly including data from preoperative or intraoperative three dimensional images. Likewise, previously marked or identified device configurations can also be displayed as a reference so that any changes in configuration due to factors such as patient shift can be monitored during the course of the procedure. Additionally, reconstructed features such as blood vessels reconstructed from contrast agent injection and subsequent imaging and image processing, or other path reconstructions as defined by a user to produce a three dimensional path, or a variety of path-like or other features extracted from three dimensional image data could be overlaid on the live X-ray display.
As the Fluoroscopic imaging system is moved or rotated about the subject, the graphically overlaid objects may be continuously updated and displayed along with the continuously updated X-ray images to provide projection images in real time to improve visualization of the orientation of the medical device and target locations.
Other graphic overlay objects that can be suitably projected onto the display may include one or more reference markers 110 on the subject body to provide a reference for the movement of the medical device 100 . In the preferred embodiment, the medical device 100 is preferably deployed from the distal end of a relatively stiff sheath inserted within the subject body. The distal end of such a sheath functions as a base for the distal end of a medical device 100 deployed therefrom. One efficient method to mark the pivot or base of the medical device as a reference marker 110 is to position the tip of the medical device 110 at the intended base, for example at the distal tip of a sheath, and then record the current location of the tip as a reference marker, as illustrated in FIG. 3 at 110 . Reference markers could also be used to indicate target locations for the tip of the medical device to access, and text or other graphic annotations could be used to distinguish and identify various locations. A pre-operative anatomical three-dimensional data set, of an endocardial surface for example, could also be graphically rendered and projected onto the display at 118 , after a suitable registration of the coordinates to the frame of reference of the X-ray is performed. Likewise, an intra-operative three-dimensional data set could also be graphically rendered and projected onto the image display.
In the preferred embodiment where a magnetic navigation system is employed for controlling the orientation of the distal tip of the medical device, a graphic annotation of the current magnetic field direction 116 could be projected onto the live Fluoroscopy Image display as a steering reference. Where a localization system for determining the position of the medical device in a frame of reference translatable to the displayed image of the Fluoroscopy system is also included, a graphical rendition of portions of the medical device as determined from the localization information obtained from the localization system can be overlaid on the X-ray image display. Rates of change of control variables such as the magnetic field, or the rate of movement of the medical device may also be determined and displayed on the X-ray image display.
A graphical representation of a virtual medical device 112 can be overlaid to show a visual reference the medical device 100 being rotated or moved before initiating actual movement of the medical device. A mathematical model of the medical device can be used to define the configuration of the virtual medical device 112 , which can model the behavior of the device relative to a desired navigation rotation to predict movement of the medical device 110 . Thus, a desired rotation or re-orientation of the tip of the medical device 110 may be evaluated through a visual representation of a virtual medical device 112 in advance of re-orientation of the actual medical device 110 . The model of the virtual medical device 112 can account for the deflective behavior of the medical device 110 relative to changes in navigation control variables such as the applied magnetic field direction, and can provide a representation of the resulting changes in configuration of the device. A graphic indication 114 of a direction for steering the medical device within the plane of the X-ray image may also be graphically overlaid onto the display for coordination with a joystick that is mapped to the X-ray plane. Likewise, a desired target such as location point 102 may be entered, and the model of the virtual medical device 112 configuration can be used to determine the appropriate change in navigation control variables to steer the tip of the medical device to the desired target destination 102 .
The imaging display of the present invention may be further augmented by the use of gated location data, for example where the gating is performed with respect to ECG (electro cardiograph) data, so that the device location is always measured at the same phase of a periodic cycle of anatomical motion such as the cardiac cycle. In a preferred embodiment, this data is input into the navigation system together with the real-time location data in a manner such that the location data may be projected onto the X-ray image display.
It should be noted that the overlay of the medical device and various objects could be controlled by a user input from an input device such as a joystick, mouse, or hand-held localized stylus, or it could automatically be controlled by a computer. Alternatively, a joystick could also be used to control the direction or steering of the medical device within the subject body. Additional design considerations such as the above modifications may be incorporated without departing from the spirit and scope of the invention. More particularly, the system and method may be adapted to medical device guidance and actuation systems other than magnetic navigation systems, including electrostrictive, mechanical, hydraulic, or other actuation technologies. Likewise, a variety of medical devices such as catheters, cannulas, guidewires, microcatheters, endoscopes and others known to those skilled in the art can be remotely guided according to the principles taught herein. Accordingly, it is not intended that the invention be limited by the particular form described above, but by the appended claims.
Operation
In operation, the imaging system of the various embodiments of the present invention display an image of an operating region together with an overlay of representations of various objects in the operating region to facilitate the user's orientation within the image. For example these objects can include points that the user has identified or marked, or which have been identified or marked for the user. The objects can alternatively or additionally include shapes, for example closed loops identifying openings in the operating region. The objects can also be reconstructions of medical devices in the operating region, based upon mathematical models of the devices or position information from a localization system. The positions and shapes of the representations automatically change as the imaging plane changes when the imaging beam and imaging plate move about the operating region. Thus the user does not lose the points of reference and landmarks that he or she may have been using prior to the reorientation of the imaging system. This reorientation can occur frequently during medical procedures as the imaging system is moved to accommodate other equipment in the procedure room (e.g. a magnetic navigation system), or when the user desires a different imaging angle to better observe the procedure.
In one embodiment the imaging system consists of an imaging beam source, an imaging plate, an imaging processor, for processing the imaging data collected by the imaging plate, and a display for displaying the image from the processed imaging data. This imaging system can be used in conjunction with another system, such as a navigation system for orienting the a medical device in the operating region in the subject, or a medical localization system for determining the location of a medical device in the operating region in the subject. Whether using the navigation system or the localization system, the user can generally identify points of interest, for example anatomical land marks or points of physiological interest. Representations of these points can be displayed on the image of the operating region from the imaging system, to help the user visualize the operating region and the procedure. However, in addition to overlaying the representation on a static image from the imaging system, the overlay can be dynamically adjusted as the imaging plane changes so that the objects not only remain on the display, but the remain in the correct position and orientation relative to the displayed image and the displayed image changes.
The method can be implemented in several ways as illustrated by FIGS. 4A and 4B . In one embodiment, shown schematically in FIG. 4A , the navigation or localization system receives information about the location of the imaging beam source and the imaging receiver, and uses this information to determine where objects of known locations in the operating region should appear on the image generated by the imaging system. More specifically, the imaging system 100 can provide the navigation system (or localization system) 102 with information about the position/orientation of the imaging beam source 104 and the imaging receiver 106 . (This is represented by arrow 108 ). Using this information the navigation system (or localization system) 104 can determine where an object of known position in the operating region should appear in an image generated by the imaging system. This information can be communicated back to the imaging system 100 so that the selected objects can be overlaid in the proper location and orientation on the image generated by the imaging system, and displayed on the display 110 . (This is represented by arrow 112 )
As the imaging beam source 104 and imaging receiver 106 move, the information provided by the imaging system to the navigation system (or the localization system), and the resulting information provided by the navigation system (or the localization system) to the imaging system is updated. (This is represented by arrow 114 ). So that representations of the selected objects can be overlaid on the images from the imaging system are updated as the imaging system moves about the operating region.
As shown in FIG. 4B , the navigation system (or the localization system) 102 can provide the imaging system with the positions of objects in the operating region. The imaging system 100 can use this information to determine where the objects should appear in an image generated by the imaging system, using the known position of the imaging beam source 104 and imaging receiver 106 , and then overlay representations of the objects on the image generated by the imaging system on the display 110 .
As the positions of the imaging beam source and imaging receiver change, the imaging system can redetermine where the objects should appear in an image generated by the system in the new configuration, and overlay the representations of the object on the image generated by the imaging system, so that the representations of the objects are updated as the imaging system moves about the operating region.
An example of a display from a graphical user interface from a magnetic navigation system is shown in FIG. 5 . The interface in FIG. 5 allows the user to import images from an x-ray imaging system, and display them in windows in the display. The magnetic navigation system allows the user to identify points in the operating region and show these points on an overlay on the image from the imaging system. The overlay becomes “persistent” such that as the imaging system is moved about the operating region, and another image is made of the operating region, the overlay is adjusted in position and/or orientation so that it correctly shows the points on the new image. This is illustrated in FIG. 5 in which two images from the operating region in different directions are depicted in side by side panes on the interface, and the overlaid objects are properly positioned and oriented in each,
FIG. 6A shows an x-ray image of an anatomical model of a human heart taken in a direction 26° to the left anterior side. An object, and more specifically a representation of a ring 200 constructed from a plurality of points 202 is overlaid on the x-ray image. FIG. 6B shows an x-ray image of the anatomical model taken in a direction 26° to the right anterior side (i.e., rotated 52° from FIG. 6A ). The representation of the ring 200 and constituent points 202 in FIG. 6B have been rotated from FIG. 6A in accordance with the principles of this invention, to remain in the proper orientation with respect to the image in the new imaging direction.
FIG. 7A shows an x-ray image of an anatomical model of a human heart taken in a direction 25° to the left anterior side. Objects, and more specifically a plurality of annotations including an “E” 204 , an “F” 206 , and a “G” 208 are overlaid on the x-ray image. FIG. 7B shows an x-ray image of the anatomical model taken in a direction 27° to the right anterior side (i.e., rotated 52° from FIG. 7A ). The representation of the annotations “E” 204 , “F” 206 , and “G” 208 in FIG. 7B have been rotated from FIG. 7A in accordance with the principles of this invention, to remain in the proper orientation with respect to the image in the new imaging direction.
FIG. 8A shows an x-ray image of an anatomical model of a human heart taken in a direction 25° to the left anterior side. An object. and more specifically a catheter 210 is overlaid on the x-ray image. The representation of catheter 210 can be generated from localization data of one or more points on the corresponding real catheter in the operating region. Alternatively, the representation of the catheter 210 can be generated from a mathematical model of the actual catheter in the operating region (for example using the control variable from the navigation system).
FIG. 8B shows an x-ray image of the anatomical model taken in a direction 8° to the right anterior side (i.e., rotated 33° from FIG. 8A ). The representation of the catheter 210 in FIG. 8B has been rotated from FIG. 8A in accordance with the principles of this invention, to remain in the proper orientation with respect to the image in the new imaging direction. FIG. 8C shows an x-ray image of the anatomical model taken in a direction 27° to the right anterior side (i.e., rotated 19° from FIG. 8B ). The representation of the catheter 210 in FIG. 8C has been rotated from FIG. 8B in accordance with the principles of this invention, to remain in the proper orientation with respect to the image in the new imaging direction.
FIG. 9A shows an x-ray image of an anatomical model of a human heart taken in a direction 25° to the left anterior side. Objects, and more specifically representations of points 212 , 214 , and 216 in the operating region are overlaid on the x-ray image. FIG. 9B shows an x-ray image of the anatomical model taken in a direction 16° to the right anterior side (i.e., rotated 9° from FIG. 9A ). The representation of the points 212 , 214 and 216 in FIG. 8B have been rotated from FIG. 9A in accordance with the principles of this invention, to remain in the proper orientation with respect to the image in the new imaging direction. FIG. 9C shows an x-ray image of the anatomical model taken in a direction 6° to the left anterior side (i.e., rotated 3° from FIG. 9B ). The representation of the points 212 , 214 , and 216 in FIG. 9C has been rotated from FIG. 9B in accordance with the principles of this invention, to remain in the proper orientation with respect to the image in the new imaging direction. FIG. 9D shows an x-ray image of the anatomical model taken in a direction 17° to the right anterior side (i.e., rotated 23° from FIG. 9C ). The representation of the points 212 , 214 , and 216 in FIG. 9D has been rotated from FIG. 9C in accordance with the principles of this invention, to remain in the proper orientation with respect to the image in the new imaging direction. FIG. 9E shows an x-ray image of the anatomical model taken in a direction 27° to the right anterior side (i.e., rotated 10° from FIG. 9D ). The representation of the points 212 , 214 , and 216 in FIG. 9E has been rotated from FIG. 9D in accordance with the principles of this invention, to remain in the proper orientation with respect to the image in the new imaging direction. | A system and method are provided for control of a navigation system for deploying a medical device within a subject, and for enhancement of a display image of anatomical features for viewing the projected location and movement of medical devices, and projected locations of a variety of anatomical features and other spatial markers in the operating region. The display of the X-ray imaging system information is augmented in a manner such that a physician can more easily become oriented in three dimensions with the use of a single-plane X-ray display. The projection of points and geometrical shapes within the subject body onto a known imaging plane can be obtained using associated imaging parameters and projective geometry. | 0 |
RELATED APPLICATIONS
This application is a continuation application and claims the Paris Convention Priority of U.S. Utility application Ser. No. 11/960,651, entitled “OFF GAS EXTRACTION AND CHEMICAL RECOVERY SYSTEM AND RELATED METHODS,” filed on 19 Dec. 2007 now U.S. Pat. No. 7,658,789, the contents of which are incorporated by reference herein.
SUMMARY
An off gas extraction system provides superior results to other systems for cleaning polluted soil and recovery of chemicals from soil. Off gas is extracted, followed by a compression and condensation. Compression and condensation produce liquid condensates and an off gas that must be further treated to produce pollutant-free exhaust. A regenerative adsorber concentrates polluted off gasses, which are sent to the front of the system. Conventional scrubbers are used on the back end of the system to produce a final exhaust as prescribed by environmental regulation. Methods of accomplishing the same are similarly provided, including business methods for efficiently remediating polluted soil by optimizing target off gas selection and processing of the same to achieve compliance with changing environmental regulations.
According to a feature of the present disclosure, a device is disclosed comprising, in combination: at least one off gas extraction source; a vacuum and compression module; and a vapor elimination module comprising: at least one condensation module to condense fluid from off gas; and a regenerative adsorbing module having a plurality of activated alumina adsorbers. Each adsorber adsorbs pollutants from a high pressure gas and desorbs the pollutants into a low pressure gas. When the low pressure gas holding the desorbed pollutants is returned into the at least one condensation module or the vacuum and compression module.
According to a feature of the present disclosure, a device is disclosed comprising, in combination: at least one off gas extraction source; a vacuum and compression module comprising: (1) a vacuum source; (2) a compressor; and (3) an aftercooler; and a vapor elimination module comprising: (1) at least one condensation module to condense fluid from off gas; and (2) a regenerative adsorbing module having a plurality of activated alumina adsorbers. Each adsorber adsorbs pollutants from a high pressure gas and desorbs the pollutants into a low pressure gas. When the low pressure gas holding the desorbed pollutants is returned into the at least one condensation module or the vacuum and compression module.
According to a feature of the present disclosure, a method is disclosed comprising extracting an off-gas gas comprising contaminants; compressing the off-gas gas to form a high pressure concentrated off-gas; routing the high pressure concentrated off-gas to a condensation module to form a condensate of the contaminants and a high pressure condensed off-gas, wherein condensate is routed to a contaminant recovery tank and the high pressure condensed off-gas is routed to a regenerative adsorbing module; adsorbing any residual contaminants from the high pressure condensed off-gas gas in the regenerative adsorbing module with a plurality of activated alumina adsorbers to produce a substantially contaminant-free exhaust gas; desorbing the adsorbers that contain contaminant with a portion of the contaminant-free exhaust gas at low pressure to form a concentrated contaminated gas that is routed to the condensation module; and scrubbing the substantially contaminant-free exhaust gas with activated carbon to produce a clean exhaust gas.
DRAWINGS
The above-mentioned features and objects of the present disclosure will become more apparent with reference to the following description taken in conjunction with the accompanying drawings wherein like reference numerals denote like elements and in which:
FIG. 1 is a block diagram of an embodiment of an off gas extraction system for removing pollutant from soils;
FIG. 2 is a block diagram of an embodiment of a module for preparing an off gas to have pollutant-laden vapor removed;
FIG. 3 is a block diagram of an embodiment of a compression/condensation system for condensing pollutant-laden vapor from a gas;
FIG. 4 is a block diagram of an embodiment of a regenerative adsorption system;
FIG. 5 is a flow chart of an embodiment of a method for removing pollutant-laden vapor from gas extracted from soil;
FIG. 6 is a flow chart of an embodiment of a process for addressing contaminants at a contaminated site;
FIG. 7 is a graph of an embodiment of experimental data of the system of the present disclosure; and
FIG. 8 is a graph of an embodiment of experimental data of the system of the present disclosure.
DETAILED DESCRIPTION
As used in the present disclosure, the term “off gas” shall be defined as gasses extracted from contaminated sources and includes soil vapors and previously collected soil vapors.
The industrial revolution marked a radical change to many aspects of society. Industrialized nations became increasingly productive and urbanized. Chemical production became centralized. Other industries utilized chemicals in the production process of other goods. Increased pollution was the result. Soil, air, and water carried unprecedented levels of pollutants over the last 200 years.
Nevertheless, during the middle of the 20 th century, social conscience and government sought to eliminate or reduce pollution where possible. The United States government passed strict environmental laws and set aside funds for cleaning polluted natural resources. Similarly, corporations and companies are taking steps to improve the nature and quality of pollutants and to address polluted natural resources.
Traditionally, pollutants trapped in the soil have been very difficult to address. Contaminated soil provides a uniquely difficult problem in that it cannot be filtered like air or water. Rather, pollutants must be drawn out of the soil. Generally, the process of drawing out the pollutant requires air or water and heat to be used to enable extraction of the pollutant as a vapor or liquid, which must then be quarantined or cleansed. Often, pollutants are removed from the soil by off gas extraction processes.
Soil vapor extraction (SVE), also known as “soil venting” or “vacuum extraction,” is an in situ remedial technology that reduces concentrations of volatile pollutants. In this technology, a vacuum is applied to wells near the source of contamination in the soil. Volatile constituents of the contaminant mass “evaporate” and the vapors are drawn toward and extracted through the extraction wells. Extracted vapor is then cleansed. The increased airflow through the subsurface can also stimulate biodegradation of some contaminants, especially those that are less volatile. Wells may be either vertical or horizontal.
SVE has been successfully applied to many petroleum derived volatile organic compounds (VOCs) as well as semi-volatile organic compounds (SVOCs). However, other chemicals present in the soil have been difficult, if not impossible, to remove using technologies prior to the present disclosure. Indeed, prior technologies are unsuited for remediation of halogenated chemicals, chloromethane, and many other volatile chemicals.
Prior technologies often rely on compression and condensation for removal of VOCs. These systems may also be coupled with scrubbing units for residual removals of contaminated vapor prior to release to the atmosphere. Usually, scrubbing units comprise granular activated carbon (GAC) traps. Once each GAC trap becomes saturated with residual contaminant, they must be replaced and new activated carbon used. Certain regenerative systems treat GAC with steam, which removes contaminants from the carbon. For certain chemicals, such as halogenated compounds, the heat and water from steam results in strong hydrohalic acids. These acids are difficult to handle, involve health and safety risks, cause corrosion, and consequently carry with them increased costs of remediation.
Moreover, other VOCs, such as chloromethane and freon are difficult to remove in compression and condensation steps due to their low condensation points. Thus, to remove these types of chemicals from the gas stream, the condensation process must cool the vapor to extremely low temperatures, which increases costs and makes prior SVE methods for dealing with these types of chemicals less attractive. Moreover, remediation sites may often contain these types of chemicals in combination with other VOCs. When contaminated vapors are not removed in the compression/condensation step, the scrubbing units become the primary SVE component for removing these types of VOCs. The result is more frequent replacement of the scrubbing reagents, as well as undesirable side effects previously discussed and many others.
Moreover, regenerative processes that require heat are potentially dangerous with VOCs that have high vapor pressures. Introducing heat in the presence of oxygen in these situations may lead to fires and explosions. In addition to potential destruction of hardware that may occur due to fires and explosions, the VOCs or dangerous byproducts may also be released generally into the atmosphere. Thus, a system is needed to allow SVE remediation for VOCs that are not suited to traditional VOC methods and systems. The present disclosure addresses this need by providing a novel enhanced SVE system and methods capable of remediation of soil containing difficult to remove VOCs.
Turning now to FIG. 1 , there is shown an embodiment of a remediation and chemical recovery system 100 . Remediation and chemical recovery system 100 generally comprises a plurality of extraction wells 110 and SVE system 200 . SVE system 200 comprises a number of subsystems, according to embodiments, including vacuum and compression module 300 , vapor elimination module 400 , and contaminant recovery module 500 . Vacuum and compression module 300 removes off gas from extraction wells 110 , removes liquid constituents recovered in the off gas removal process, and compresses the off gas. Vapor elimination module 400 removes contaminated vapor from the gas, producing a substantially dry gas as an intermediate result. Finally, contaminant elimination module 500 collects chemical vapors and scrubs the substantially dry gas for residual contaminant.
According to an embodiment of vacuum and compression module 300 in FIG. 2 , contaminated vapor is removed from extraction wells 110 and transferred via inlet conduit 302 into vacuum and compression module 300 . According to embodiments, water and gas are separated using gas/water separator 310 to prevent liquid from entering compressor 330 . According to embodiments, gas/water separator 310 may be, for example, a 60 gallon Manchester vertical tank (Manchester Tank, Franklin, Tenn.). Gas/water separator 310 comprises an inlet connected to inlet conduit 302 , a gas outlet, and a liquid out.
The gas outlet is connected to inlet blower, for example a Roots type blower (e.g., frame size 36 powered by 116 cfm at 10″ Hg, 5-10 horsepower, 3 phase, totally enclosed, fan cooled (TEFC) 240/280 volt electric motor). Blower 320 is used to create a vacuum that pulls vapor from extraction wells 110 . Other similar vacuum creation devices may be used depending on the desired gas flow rate, etc. as known and understood by a person of ordinary skill in the art.
As shown in FIG. 1 , the liquid inlet connects to transfer pump 360 , which pumps liquid from gas/water separator 310 into initial contaminant recovery tank 370 . Generally, depending on the well configuration, little water will be extracted from extraction well 110 . However, if the water table is high, slurping may occur necessitating gas/water separator 310 to separate the water from the gas. According to this configuration, holes are inserted into pipes at each extraction well site, some above that water table and some below. The vacuum pulls both vapor and water from the well, which is then separated by gas/water separator 310 .
Transfer pump 360 removes liquid from gas/water separator 310 . Transfer pump 360 may be, for example, a centrifugal, 120/230 volt, ½ horsepower motor pump capable of moving 20 gallons per minute, according to embodiments. Naturally, extraction wells 110 that produce large volumes of water may need transfer pump 360 that is capable of pumping liquid at a more rapid rate. Similarly, extraction wells no producing only nominal amounts of water may be fitted with transfer pump 360 that moves fewer gallons per minute. The exact choice of transfer pump 360 will be known and understood by artisans.
Initial contaminant recovery tank 370 may be any tank suitable for the purpose of collecting contaminated liquids. As described below, a specific gravity separator may be disposed between transfer pump 360 and initial contaminant recovery tank 370 to separate each specific contaminant from the other contaminants, according to embodiments.
Turning back to FIG. 2 , inlet blower 320 moves gas containing contaminated vapor from gas/water separator 310 to compressor 330 . Compressor may be any number of conventional air compressor systems known to artisans, e.g., a Quincy Model Q 5120 reciprocating compressor, 94 scfm at 175 psi, powered by a 25-horsepower TEFC 240/280 volt electric motor. A person of ordinary skill in the art will know and understand the applicable compressors to use based on the relevant parameters in the system. According to embodiments, air compressor 330 will be able to compress gas to at least 175 psi. Compressed gas containing contaminated vapor concentrates the contaminated vapor for later removal in vapor elimination module 400 .
After gas is compressed with gas compressor 330 , gas is routed to aftercooler 350 , which commences a first round of cooling for the compressed gas containing the contaminated vapor. According to embodiments, aftercooler 350 may be comprised of a Arrow model AFC 120-1 air to air cooler system (at 150 psi and 180 scfm). As gas is compressed, temperature of gas increases substantially in compliance with that algorithm defined by or known as the ideal gas law. Aftercooler 350 provides the initial cooling of hot gas prior to full condensation in vapor elimination module 400 . As the hot gas cools, initial condensation may occur and an amount of contaminated vapor may condense. The condensate is transferred from aftercooler 350 via aftercooler conduit 355 to initial contaminant recovery tank 510 .
Exhaust from vacuum and compression module 300 is directed to vapor elimination module 400 via vapor elimination inlet conduit 352 . According to embodiments, vapor elimination module 400 comprises condensation module 410 and regenerative adsorber module 450 . Vapor is initially directed to condensation module 410 . In condensation module 410 , a great majority of contaminated vapor is condensed and caused to be collected by primary contaminant recovery tank 510 . In regenerative adsorber module 450 , residual contaminated vapor is captured and routed to the front on SVE system 200 and rerouted into vapor elimination module 400 ; clean air from regenerative adsorber module 450 is exhausted to activated carbon scrubbers 520 a , 520 b , 520 c.
According to an embodiment shown in FIG. 3 , further differentiation of other systems is schematically illustrated, whereby, for example condensation module 410 comprises a heat exchange system for reducing the temperature of the gas containing contaminated vapor. This module responds to ongoing challenges others have had in dealing with certain volatiles which are not easily converted into the liquid phase. The process causes many chemicals to condense into a liquid, which is subsequently routed to contaminant recovery module 500 .
According to embodiments, condensation module 410 comprises a plurality of heat exchanging mechanisms 412 , 416 . Air/air heat exchanger 412 accomplishes initial cooling of compressed contaminated vapor. Importantly, air/air heat exchanger removes virtually all of the water and water vapor in the compressed gas. After initial cooling has occurred, the compressed contaminated vapor is transferred to air/refrigerant heat exchanger 416 via warm vapor conduit 414 . Further cooling of the compressed contaminated vapor occurs in air/refrigerant heat exchanger 416 , causing condensation of the compressed contaminated vapor as the temperature of the gas containing the contaminated vapor drops below condensation point depending on the chemical being condensed. At this stage the compressed vapor is virtually dry and free of water and water vapor, according to embodiments.
Air/air heat exchanger 412 and air/refrigerant heat exchanger 416 work in tandem to heat and cool their respective input and output gasses. The cold output from air/refrigerant heat exchanger 416 is routed through air/air heat exchanger 412 via cold vapor conduit 418 . Warm gas incoming to air/air heat exchanger 412 from aftercooler 350 via vapor elimination inlet conduit 352 is therefore cooled by the cold gas routed into air/air heat exchanger 412 and the cold gas in cold vapor conduit 418 is likewise warmed by warm gas incoming from aftercooler 350 via vapor elimination inlet conduit 352 .
According to embodiments, air/air heat exchanger 412 and air/refrigerant heat exchanger 416 are disposed in condensation module 410 in pairs. Typically, the pairs of heat exchangers 412 , 416 work in cycles. During the cooling phase in air/refrigerant heat exchanger 416 , condensate of the compression contaminated vapors forms. Condensate will continue to form as long as refrigerant remains in air/refrigerant heat exchanger 416 . To remove the condensate, the air/refrigerant heat exchanger 416 must undergo a thawing cycle to liquefy the condensate and remove it, which requires the refrigerant to be removed. Thus, by using pairs, first air/refrigerant heat exchanger 416 cools while the second air/refrigerant heat exchanger 416 thaws. Once thawing is complete, the respective functions are reversed and the first air/refrigerant heat exchanger 416 thaws while the second air/refrigerant heat exchanger 416 cools. Thawed liquefied contaminant is removed from heat exchangers 412 , 416 as would be known to artisans. The heat exchange process described herein is accomplished, according to embodiments, in cycles to optimize heat exchange and prevents air/refrigerant heat exchanger 416 from freezing up.
According to embodiments, refrigerant and warm gas to be cooled by refrigerant are input at the same location and experiences parallel flow rather than cross flow, as known in the art. Embodiments employing parallel flow are more rapidly cooled, allowing for shorter cycle times and improving the overall efficiency of the system. According to embodiments, cross flow configurations and parallel flow configurations may be chosen on a case by case basis as would be known to a person of ordinary skill in the art.
Air/refrigerant heat exchanger 416 exchanges heat as would be known to a person of ordinary skill in the art. That is, the refrigerant provides the cooling for the gas. The final temperature range of the gas depends on the coolant used, airflow, and other factors. According to embodiments, if a majority of contaminant condenses in air/air heat exchanger 412 , then gas flow may be increased or cycle time may be decreased as a matter of efficiency. Similarly, where contaminated vapor fails to condense at an efficient rate, gas flow may be decreased or cycle time may be increased to expose gas to refrigerant for a longer period.
According to other embodiments where heat exchange occurs in cycles, gas flow rate remains constant, but the duration the gas is exposed to the heat exchangers is varied. Thus, if air/air heat exchanger 412 inefficiently condenses vapor, the duration in the air/refrigerant heat exchanger 416 may be increased in each cycle. Thus, variations in the optimization of gas temperatures may likewise be effected.
According to embodiments, aftercooler 350 monitors the temperature of the compressed contaminated gas to deliver it to condensation module 410 within an optimal temperature range for condensation cycling. Compressed contaminated gas that is too cold will not effectively warm cold exhaust from air/refrigerant heat exchanger 416 and compressed contaminate gas that is too warm will be inefficiently cooled in condensation module 410 requiring cycle times to be increased to remove a substantial portion of contaminated vapors. Thus, tuning aftercooler to provide an optimal compressed contaminated gas temperature prior to delivery to condensation module 410 increases efficiency of the system and serves as an optimization step.
For example, condensed vapor leaves compressor 330 at approximately 250° F. and approximately 180 PSI. Aftercooler 350 reduces the temperature from approximately 250° F. to approximately 85° F. As previously described, an initial condensate will be formed as the gas is initially cooled in aftercooler 350 . The initial condensate is transferred to an initial contaminant recovery tank or, according to embodiments, primary contaminant recovery tank 510 in contaminant recovery module 500 .
Gas is transferred from aftercooler 350 to air/air heat exchanger 412 via vapor elimination inlet conduit 352 . Gas entering air/air heat exchanger is cooled from approximately 85° F. to approximately 20° F., as the heat exchange occurs between the gas from aftercooler 350 and the cold gas from air/refrigerant heat exchanger 416 . Further condensate is formed as the gas further cools to approximately 20° F. It is transferred to primary contaminant recovery tank 510 in contaminant recovery module 500 via contaminant recovery module conduit 420 , according to embodiments. Specific gravity separator 508 may be included to separate contaminants by specific gravity and store separated chemical contaminants in multiple contaminant recovery tanks 510 .
The gas cooled to 20° F. then transfers to air/refrigerant heat exchanger 416 for further cooling to a cold gas from approximately 20° F. to approximately (−30)° F. due to the heat exchange between gas and refrigerant, as known to artisans. As depicted in FIG. 3 , refrigeration unit 430 provides refrigerant via refrigerant inlet conduit 432 to air/refrigerant heat exchanger 416 for cooling of the cold gas. To prevent freezing up problems, gas/gas heat exchanger 412 may be cycled with gas/refrigerant heat exchanger 416 , as would be known to artisans. Thus, prior to freezing up, warmer gas from gas/gas heat exchanger 412 is used to warm the cold gas in gas/refrigerant heat exchanger 416 . After cooling, the refrigerant returns to refrigeration unit 430 via refrigerant outlet conduit 434 , according to embodiments. At this point in the process, virtually all water vapor has been removed from the gas, but chemical vapors may remain due to varying dew points and vapor pressures.
According to an embodiment, the final temperature of the cold gas depends on the length of time the gas is cooled and the refrigerant. In air/refrigerant heat exchanger 416 final condensation occurs and the condensate is collected after thawing and transferred to contaminant recovery module 500 via contaminant recovery module conduit 420 . The dry cold gas is then transferred to air/air heat exchanger to cool incoming warm gas from aftercooler 350 and warm the cold gas. According to embodiments, cold gas is then routed to regenerative adsorber 450 to remove residual chemical vapors via regenerative adsorber inlet conduit 452 .
According to embodiments, multiple condensation modules 410 may be used in parallel or in series to improve efficiency of the condensation process. A person of ordinary skill in the art will understand that each remediation site may require optimization dependant on the particular contaminants at the site, their relative abundance, their vapor pressures, their dew points, and their specific heat of phase conversion.
However, the prior art systems have been unable to be industrially effective for condensation of more challenging contaminants. The present invention's optimizing differentiates it from extant systems, with condensation modules 410 used in parallel to provide for greater gas flow through the system. Conversely, condensation modules 410 may be used in series to expose contaminated vapor to subsequent condensation steps in an attempt to remove greater percentages of total contaminants during the condensation step, according to embodiments.
After the condensation step, residual contaminated vapor typically remains in the gas due to incomplete condensation or chemicals that are not cooled enough or for long enough for condensation to occur. According to an embodiment in FIG. 4 , high-pressure gas containing residual contaminated vapor is routed to regenerative adsorber module 450 via regenerative adsorber inlet conduit 452 . As shown, two adsorption chambers 460 a , 460 b work in tandem to adsorb residual contaminated vapor. During operation, one adsorption chamber 460 a , 460 b adsorbs residual contaminated vapor while the other adsorption chamber 460 b , 460 a deadsorbs contaminated vapor. The process of desorption regenerates adsorption material 462 a , 462 b for re-adsorption of contaminated vapor.
According to an embodiment, an adsorption material 462 a , 462 b is activated alumina. A person of ordinary skill in the art will readily know and appreciate that other, similar materials may be used in adsorption module depending on the nature of the remediation site, the chemicals involved, and goals of each remediation project. Adsorption by adsorption materials, such as activated alumina, carbon, or resins, occurs at high pressure; desorption occurs at low pressure. Other similar materials and materials specifically suited to adsorption of specific chemicals are expressly contemplated as would be known to a person of ordinary skill in the art. Both adsorption and desorption are temperature insensitive processes, which makes the present system superior for many types of remediation, such as with halogenated chemicals due to the lack of necessity to introduce heat and form strongly acidic byproducts as a result in the desorption process.
Contaminated vapor is introduced to regenerative adsorber module 450 via regenerative adsorber inlet conduit 452 . Disposed between regenerative adsorber inlet conduit and each adsorption chamber 460 a , 460 b are inlet valves 454 . Inlet valve 454 control which adsorption chamber 460 a , 460 b is adsorbing residual contaminated vapor and adsorption chamber 460 a , 460 b desorbing contaminated vapor. During the adsorption process, inlet valve 454 is in an open position allowing gas containing residual contaminated vapor to enter adsorption chamber 460 a , 460 b and contact adsorption material 462 a , 462 b . During the desorption process, inlet valve 454 is in a closed position to prevent gas from entering adsorption chamber 460 a , 460 b.
During the adsorption process, gas containing residual contaminated vapor is forced through adsorption material 462 a , 462 b in adsorption chamber 460 a , 460 b . Adsorption material 462 a , 462 b removes vapor from the gas, including contaminated vapor. As vapor is removed from the gas, adsorption material 462 a , 462 b charges with contaminated vapor. Gas leaving adsorption chamber 460 a , 460 b is therefore substantially clean. Artisans will recognize that one of flow rate of the gas containing contaminated vapor or cycle time will vary from remediation site to remediation site.
Depending on the types of chemicals being removed, the concentration of the contaminants, the relative amount of contaminated vapor removed in previous remediation steps, for example compression/condensation, and the efficiency of adsorption material 462 a , 462 b in removing particular vapors from the gas, the parameters within which the system runs will differ. To that end, a person of ordinary skill in the art will know and understand that flow rate or cycle time, adsorption material 462 a , 462 b , surface area of adsorption material 462 a , 462 b , and other similar variables known to artisans will be evaluated and optimized on a per site basis. In some cases, multiple regenerative adsorption modules 450 will be used in series to accomplish a desired reduction in contaminated vapor passing through vapor elimination module 400 .
According to an embodiment where adsorption material 462 a , 462 b is activated alumina or other materials, adsorption of vapor in gas occurs at high pressure. For example and according to an embodiment, cold gas leaving condensation module 410 is at approximately 150 PSI (referring back to FIG. 1 ) having been compressed prior to entering condensation module 410 . After leaving condensation module 410 and entering regenerative adsorber module 450 , gas pressure is still at approximately 150 PSI.
Referring again to FIG. 4 , once gas has been exposed to and caused adsorption material 462 a , 462 b to be charged with contaminated vapor, the exhaust is substantially clean. It escapes through clean exhaust conduit 472 . Disposed on clean exhaust conduit 472 are clean exhaust valves 474 , according to the exemplary embodiment. Generally, at least one clean exhaust valve 474 is disposed along clean exhaust conduit 472 per adsorption chamber 460 a , 460 b , although multiple clean exhaust valves 474 are contemplated as would be known to artisans. Clean exhaust conduit 472 releases substantially clean gas into the ambient air or routes the substantially clean gas to scrubbers 530 , according to embodiments. A back pressure regulator may be disposed prior along clean exhaust conduit 472 to maintain a baseline of pressure in remediation and chemical recovery system 100 .
According to embodiments, clean exhaust valves 474 shunts a portion of substantially clean gas for the purpose of desorption. When clean exhaust valve 474 is “closed,” it allows a small flow of clean exhaust gas to flow to charged adsorption chamber 460 a , 460 b and through charged adsorption material 462 a , 462 b . This low pressure flow causes adsorption material 462 a , 462 b to release the contaminated vapors collected in the charging step. These vapors exit through exhaust conduit 470 as inlet valve 454 is closed for charged adsorption chamber 460 a , 460 b as the desorption step occurs.
To that end, clean exhaust valves 474 are configured to shunt a portion of the substantially clean gas into adsorption chamber 460 a , 460 b that is desorbing contaminated vapor. Because desorption occurs at lower pressure, a small percentage of the total clean exhaust gas is diverted as a low pressure gas to desorbing adsorption chamber 460 a , 460 b , while the remaining substantially clean gas continues through clean exhaust conduit 472 . The process of shunting a small percentage of substantially clean gas may be accomplished by partially opening clean exhaust valve 474 or through the use of a multiple valve system, as would be known to artisans. For example, clean exhaust valve 474 may comprise one valve that allows low-pressure substantially clean gas to pass during adsorption chamber's 460 a , 460 b desorption cycle and a separate valve that may be fully opened to allow high-pressure substantially clean gas to escape during the adsorption cycle. The implementation of such a system will be known and understood by a person of ordinary skill in the art.
Consequently, as one adsorption chamber, e.g., 460 a , of regenerative adsorber module 450 is being charged with contaminated vapors and exhausting substantially clean exhaust gas, adsorption chamber, 460 b is being desorbed of contaminated vapors previously collected and contained in adsorption material 462 b . Desorption occurs as a percentage of the substantially clean gas forming a low pressure flow is shunted into adsorption chamber 460 b . After adsorption chamber 460 a becomes fully charged, the system is reversed and adsorption chamber 460 b is charged with contaminated vapors while adsorption chamber 460 a is desorbed of the previously collected contaminated vapors.
During the desorption cycle of adsorption chamber 460 a , 460 b , adsorption material 462 a , 462 b starts in a state wherein adsorption material 462 a , 462 b is fully charged with contaminated vapor. As low-pressure substantially clean air is shunted into adsorption chamber 460 a , 460 b , vapor contained in adsorption material 462 a , 462 b is released from adsorption material 462 a , 462 b into the low-pressure substantially clean gas. The resultant gas comprises concentrated contaminated vapor. The gas containing the concentrated contaminated vapor is then routed through exhaust conduit 470 to vacuum and compression module 300 for recompression and rerouting through compression/condensation.
Multiple regenerative adsorber modules 450 may be placed in series or in parallel as a matter of efficiency to ensure adequate removal of particularly difficult contaminants. Moreover, efficiencies of the present system may provide for increased gas flow rates, and thus more rapid remediation of a polluted remediation site, due to increased efficiency of remediation and chemical recovery system 100 over conventional SVE systems.
Thus, artisans will appreciate that nearly all contaminated vapor from the ground is eliminated by compression/condensation. Vapor that escapes compression/condensation is captured by adsorption material 462 a , 462 b for reconcentration during the desorption process. The reconcentrated contaminated media will then be more readily condensed out during a second round of compression/condensation owing to the increased concentration of the contaminated vapor, where it would have originally escaped due to the fact that the concentration of contaminated vapor dropped below a critical point where no additional contaminated vapor of a given chemical could be condensed out of the gas. The compression/condensation-adsorption cycle is repeated until the measured volumetric concentration output of contaminant being removed shows the remediation site is substantially clean.
Referring now also to FIG. 1 , scrubbers 520 a , 520 b , 520 c may be introduced into SVE system 200 to remove contaminated vapor that escapes regenerative adsorption module 450 . Scrubbers 520 a , 520 b , 520 c may be conventional GAC traps. As shown in FIG. 1 , scrubbers 520 a , 520 b , 520 c may occur in series to achieve a desired gas concentration of contaminant. Scrubbers 520 a , 520 b , 520 c are connected to vapor elimination module 400 via clean exhaust conduit 472 . The specific acceptable final concentration of each contaminant will be known to a person of ordinary skill in the art and defined by applicable environmental statute. According to embodiments wherein GAC is used as the scrubbing media, scrubbers 520 a , 520 b , 520 c will periodically need to have GAC replaced once it becomes fully charged with contaminant. After gas is scrubbed to the desired contaminant concentration, gas is discharged to the ambient air via discharge conduit 530 .
According to an embodiment of a method for vapor extraction shown in FIG. 5 , vapor is extracted from the soil of a remediation site 1010 . These vapors, as previously discussed contain vapors contaminated with pollutant. After extraction, the off gas is compressed 1020 as previously described. Thereafter, the compressed gas is cooled in a condensation process 1030 , which causes much of the contaminated vapors to condense into a liquid form that may be captured.
Residual contaminated vapors not captured by the compression and condensation process are routed to a regenerative adsorber 1040 . Once gas is treated in regenerative adsorber step, it is substantially clean. It is exposed to scrubbing with activated carbon 1060 to ensure the final exhaust is virtually clean. Prior to scrubbing, a portion of the substantially clean gas is routed through the regenerative adsorber at low pressure. The regenerative adsorber collects and then releases contaminated vapor as a concentrated vapor 1050 which is routed to the compression step 1020 .
Likewise disclosed is a method for optimizing the use of the systems of the present disclosures. The optimization method ensures efficient flow. Initially, plans are generated to do this based on ostensive containments to be addressed. These plans may be directed towards general remediation of a site, to specific contaminants, or according to the directive of a regulatory authority, such as the United States Environmental Protection Agency. Generally, the plan will include use of a remediation system, such as the SVE system disclosed herein. Depending on the particular contaminants to be addressed, optimizations of the remediation will address the particular parameters of the remediation system.
For example, a remediation site may be contaminated with difficult to remove contaminants such as chloromethane or freon that will be removed by compression and condensation inefficiently. In these types of cases, for example, airflow, cycle time, or both may be reduced to optimize performance of the remediation system. In other embodiments, airflow may be increased when compression and condensation is efficient. Additionally, the freeze and thaw cycles of the compression and condensation modules may be varied and optimized based on the plan. Similarly, decisions may be made to use systems with multiple compression and condensation modules and regenerative adsorber modules in series or in parallel, depending on embodiments. Similarly, the adsorption and desorption may be cycled to adjust the system to site conditions, as necessary and according to embodiments.
According to an embodiment of a method for addressing soil remediation as shown in FIG. 6 , the site is first tested and the contaminants for a particular site identified 1100 . After determination of the types, concentrations, and relevant data regarding the contaminants, a remediation plan is developed 1110 . The remediation plan details flow rates, locations for extraction of contaminated vapor, and other similar considerations that would be useful in formation of the remediation plan. Artisans will understand the relevant considerations in the formation of the remediation plan.
Prior to, during, or after formation of the remediation plan, the plan may be optimized 1120 , according to embodiments. The optimization process generally comprises the cross-referencing of the contaminants to be removed with a database of parameters for removal of known contaminants. The database may be computerized or be another collection of data regarding the parameters in which contaminants may be extracted using a particular remediation technology. As contaminants will have varying extraction and chemical properties, a specific set of operating parameters for a remediation system may efficiently address a subset of contaminants while inefficiently addressing others. Optimization of the remediation plan will address the varying properties of the contaminants to create an efficient removal process that addresses all of the contaminants present without the undue waste in energy expenditure and resources associated with brute force and less efficient techniques.
After formation of an optimized remediation plan, the plan is executed 1130 . After and during execution of the plan, the nature and quantities of the contaminants removed may be evaluated 1140 , resulting in a set of data. This set of data then may be used to satisfy regulatory requirements imposed by a regulatory body 1150 , according to embodiments. Moreover these data may be used to evaluate the remediation plan and the progress in overall remediation of the site.
Once the contaminants are known, the preliminary plan may be optimized using a database of recovery parameters as provided by an entity commissioning the site remediation or a regulatory authority. As these parameters tend to vary by the remediation site or over time (e.g., state and Federal environment regulations), optimization remains current, and the execution of the plan occurs such that the applicable parameters are met or exceeded.
Execution occurs as would be known and understood by a person of ordinary skill in the art. For example, if the SVE system of the present disclosure is used, the process occurs as described herein according to the plan and in accordance with the optimization rules.
After or during execution of the plan, the exact nature and quantities of the species recovered and remaining may be measured as a metric for determination of the successful execution of the plan. Moreover, the quality of the exhaust released from the remediation system into the environment may be monitored and measured. These data may then be examined for compliance with the regulations imposed by the regulatory authority. Examples of regulatory authority may be environmental groups, government entities such as legislatures and enforcement agencies (e.g., EPA), and other groups maintaining standards for environmental remediation.
According to embodiments, recovered contaminants may be separated and reused. Recycling of pure or substantially pure contaminants reduces the need to produce the contaminants for use in other useful applications, which further reduces environmental impact by reducing waste associated with the production of the contaminants. Contaminants may be separated and reused as part of a remediation process, such as by installing a specific gravity separator as previously described, or in an after remediation process as would be known and understood by artisans.
Example 1
A site was selected for remediation in southern California, wherein the system optimization was conducted to maximize the efficiency of the soil vapor extraction (SVE) system and expedite site cleanup. The SVE system primarily targeted volatile organic compound (VOC)-impacted soils beneath a former refrigerant plant and the immediate surrounding areas. The results that follow detail the monitoring of well cycling and a description of treatment system performance over a 6-month period.
Pilot testing of the remedial system was initiated 3 years earlier. Full-scale operation began a year prior to the monitoring reported in Example 1. Routine system monitoring was conducted to maximize contaminant removal while complying with South Coast Air Quality Management District (SCAQMD) regulations and permits.
The site was constructed in 1919 to produce sulfuric acid and process spent sulfuric acid generated at an oil refinery, located west of the site. Since that time, chemical manufacturing operations included the following activities: sulfuric acid production from 1920 to 1972, phthalic anhydride manufacturing from 1963 to 1982 (the phthalic anhydride plant was demolished in 1996); and production of refrigerants from 1964 to 2003.
Refrigerants were initially produced in 1964, including chlorofluorocarbons (CFCs) and hydrochiorofluorocarbons (HCFCs) such as trichlorofluoromethane (R-11), dichlorodifluoromethane (R-12), chlorodifluoromethane (R-22), and 1,1-dichloro-1-fluoroethane (R-141b). Raw materials for CFC/HCFC production included hydrofluoric acid, carbon tetrachloride, chloroform, 1,1,1-trichloroethane (1,1,1-TCA), and antimony pentachloride catalyst.
Several blends of the refrigerant 1,1,2-trichlorotrifluorethane (R-113) with organics (used primarily in the electronics industry) were packaged at the site from the early 1980s through January 2003. Additional organic compounds including methyl alcohol, ethyl alcohol, cyclopentane, hexane, methylene chloride, isopropanol, and acetone were used in the different blends. Refrigerant blending and production ceased on Jan. 31, 2003. The site user implemented corrective action in the vicinity of the refrigerant plant to remove VOCs in the zone of greatest impact and to minimize future impacts to groundwater.
Various interruptions to the SVE system operation during the monitoring period occurred for demolition activities over the 6-month monitoring period. The system was shut down at one point to meet the ongoing construction health and safety requirements.
Previous investigations documented the presence of VOCs in soil, soil gas, and groundwater beneath the site. The highest concentrations of VOCs, including CFCs and HCFCs, were located beneath the refrigerant plant.
SVE was selected as the preferred remedial measure after evaluating several different methods and technologies. SVE is a treatment process that is proven effective in remediating coarse-grained soils impacted with VOCs. Physical site constraints, such as the depth of impacted soils and site operations, were also considered in the selection of an appropriate technology.
The SVE system included a network of 12 vapor extraction wells (VEW) screened in multiple depth intervals. The system presented in the present disclosure was used to extract VOCs from the remediation site.
During initial pilot testing of the system, vapors were extracted from only one well and the condensed fluids were collected in half-ton pressure cylinders. A Department of Transportation (DOT) 2.2 classification, 50,000-pound capacity iso-tanker was delivered to the site and connected to the treatment system. This tank provided additional capacity to allow full-scale SVE operation. The SVE system was expanded to extract from multiple wells and from wells with higher contaminant concentrations.
The SVE system operated under a SCAQMD permit. This site-specific permit was issued with the following conditions addressing air emissions at the outlet of the scrubbers:
VOC concentrations shall not exceed 3 parts per million by volume (ppmv). Carbon tetrachloride shall not exceed 1.8 ppmv. Chloroform shall not exceed 0.9 ppmv.
Whenever the VOC concentration reaches 3 ppmv (as hexane), the carbon in the scrubbers shall be replaced with fresh adsorbent.
To ensure compliance with the SCAQMD permit, the system effluent was monitored by organic vapor sensors that were connected to the main system controls. The sensors automatically shut the system down if the effluent concentration exceeded the SCAQMD permit limit.
The initial phase SVE system installation included the installation of the condensation process equipment and piping to an existing well. Based on the radius of influence (ROI) data, it was determined that 12 wells were sufficient to accomplish the remediation goals.
During the monitoring period, the inventor periodically visited the site to conduct system maintenance operations, including adding oil to compressors, emptying drums, changing cylinders, and replacing filters, tubing, gaskets, carbon, and valves.
The delivery of a 50,000-pound capacity iso-tanker to the site immediately prior to the monitoring period provided greater operational flexibility and expanded product storage capacity. The full-scale operation strategy involves the cycling of 12 extraction wells to maximize the system influent concentrations.
The objective was to reduce extraction well concentration to less than 2000 ppmv. The outer wells were cycled periodically since demolition activities prevented use of other wells. FIG. 7 illustrates the system influent VOC concentrations for the remediation site. As indicated, the peaks are indicative of new wells being opened and added to the SEV system. As of the end of the reporting period, all system wells appeared to be near or below 2000 ppmv.
VOC mass removal during the monitoring period is shown in FIG. 8 . Measurements of product removed since the system operations began are listed in Table 5. The mass total does not include dissolved VOCs removed in the condensed aqueous waste stream or vapor-phase VOCs adsorbed to carbon, which are considered negligible in comparison to the pure-phase product removed. The total mass recovered was calculated by weighing the iso-tank before and after each replacement. The combined mass of solvents recovered during the monitoring period was 7,960 pounds. Over the course of the whole experiment, 110,202 pounds of VOCs were removed, as shown in FIG. 8 .
While the apparatus and method have been described in terms of what are presently considered to be the most practical and preferred embodiments, it is to be understood that the disclosure need not be limited to the disclosed embodiments. It is intended to cover various modifications and similar arrangements included within the spirit and scope of the claims, the scope of which should be accorded the broadest interpretation so as to encompass all such modifications and similar structures. The present disclosure includes any and all embodiments of the following claims. | An off gas extraction system provides superior results to other systems for cleaning polluted soil. Off gas is extracted, followed by compression and condensation. Compression and condensation produce an off gas that must be further treated to produce pollutant-free exhaust. A regenerative adsorber cleans the influent gas/air by adsorbing residual chemical vapor and concentrates the removed chemical vapor and reprocesses them. Conventional scrubbers are used on the back end of the system to produce a final exhaust as prescribed by environmental regulation. Methods of accomplishing the same are similarly provided, including unique business methods for conforming extraction plans with current environmental regulations and compliance impact generation based on an evolved knowledge base. | 1 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a process of copper recovery using an ion exchange resin, and more particularly one which will allow 100% recovery of copper from an acid process stream while neither utilizing more than negligible water uptake nor producing any water borne metal laden waste, by stoichiometrically balancing the water between the absorption, elution and wash. The invention also can also be utilized to increase the recovery of copper and other metals such as zinc and nickel in existing process environments.
[0002] In terms of the history of copper recovery generally, in the late 1960s and into the 1970s began the rise of a process called SX-EW (Solvent Extraction Electro-Winning) for the recovery of copper from soluble copper ore leachates. This technique has evolved to permit recovery of copper, of London Metal Exchange grade, from large heap leach operations producing copper pregnant leach solutions (PLS) in the range of 1-6 grams of copper in a liter of PLS. The economics of the SX process, since it is based upon an equilibrium, favor the use of higher solution grades as a copper input stream. When solution copper levels drop below 1 gram per liter SX economics become distinctively less attractive.
[0003] One reason that the investment and operating economics deteriorate with lower PLS grades results from the inherent design of the SX systems. The size of the SX plant is a function of the phase disengagement rates between the solvent and the aqueous liquids. This size is therefore a function of volumetric flow rate and is limited in its efficiency by the liquid contact and mixing, among other factors. In contrast, the size of an IX system is directly related to the kinetics of adsorption and de-sorption of the copper species and therefore is a function of the mass flow of copper production.
[0004] Further, because the SX operation has a system which depends upon a limited number (typically one or two) of equilibrium extraction stages and fails to have the potential to remove 100% of the copper, the scale of SX must tend to be large in order to be economic and the SX operation will always produce loss of copper in a waste stream. Depending upon where the copper recovery operation occurs, hazardous waste necessarily is created. CIX in contrast has many stages in which equivalent equilibrium contact in a short length of resin bed and can be easily configured to reduce copper in the bed effluent to very low levels to obtain high recoveries in a single operation.
[0005] Despite the inherent advantage of CIX in terms of extraction efficiency, conventional continuous ion exchange (CIX) still suffers several major obstacles, and a discussion and illustration of these problems will be aided by a discussion of the state of the art of aspects of the best known CIX system. Although the processes described in the prior art and the invention will be couched in terms of copper generally, the overall process can be used with other metals which are subject to being treated with the same processes. In terms of an overall mine process, crushed ore is contacted with an acidic aqueous solution which causes the copper in the ore to form a soluble copper solution. The soluble, acidic aqueous copper solution is allowed to contact an ion exchange resin, commonly reported in the literature as XFS 4195/4196/43084 which is commercially available from DOW Chemical Company, Liquid Separations, P.O. Box 1206 Midland, Mich. 46842-1206 under the DOWEX trademark. The geometry into which these resin ion exchange materials are placed can vary widely based upon the expected flow rates, regeneration requirements (both timing and flow).
[0006] Details of the operation of the above resins are given in a paper entitled “Copper Selective Ion Exchange Resin with Improved Iron Rejection”, Journal of Metals Vol 31, No 3, 1979, R. R. Grinstead, Dow Chemical USA.
[0007] The performance of the resins are given in an article entitled “Copper Recovery from Leach Liquors using Continuous Ion Exchange”, Randol Conference, Vancouver 1998, Rossiter, Gordon J.; Carey, Kenneth C. As described therein, one of the peculiarities of utilizing a column of the types described above is the column's affinity for trapping iron, if only momentarily, before the column is fully selectively loaded with copper. As a result, the basic column operation includes loading with a copper stream (which may contain iron), while (1) fully loading the bed with a pure copper stream to displace any iron which may have been attracted onto sites not fully saturated with copper, or (2) possibly introducing a dilute acid stream dosed with SO 2 to remove impurities and reduce any Fe 3+ to Fe 2+ , the latter ionic species having a lesser affinity for the resin sites.
[0008] Since the Fe is displaced by the copper during a column's normal activity, any residual Fe buildup is at the downstream flow site and so the scrub process is accomplished with flow in the same direction as that in which copper absorption operation occurred. The scrub reduces the residual Fe on the resin to a lesser percentage of the total Fe which was originally absorbed along with the copper.
[0009] The beginning of the copper stripping step also quickly elutes the remaining Fe (the lesser percentage) still present on the resin after the scrub operation into the first volume of stripping electrolyte used. Only a small amount of copper is lost in this first volume of stripping electrolyte and the remainder of the stripping electrolyte essentially completely removes the remainder of the copper. Stripping uses 70-200 grams per liter H 2 SO 4 , can be done with one bed void volume but is more complete with two.
[0010] The overall process described includes a copper/iron feed inlet stream (PLS), a depleted copper/iron raffinate exit stream, a spent electrolyte inlet stream which is a adequate to absorb copper during stripping, and the strong electrolyte exit stream carrying the copper product from the stripped column.
[0011] However, the Rossiter system proposed in the 1998 paper proposed a continuous scheme yet failed to solve the issue of the water balance, complete copper recovery and closed loop operation clearly.
[0012] In a summary of the state of the art for copper extraction from leach solutions, Alan A. Taylor, in his article entitled “Copper SX/EW Any Rivals in Sight Alta Metallurgical Services”, February 2002”, mentions the potential of IX for the future but only considers IX as a pre-concentration technique to boost the concentration of the process stream.
[0013] Jones and Pyper along with Grinstead of Dow Chemical worked in the 1970s and early 1980s developing resin based materials and IX techniques for copper recovery. A number of publications resulted, including “Recovery of Non-Ferrous Metals from Acidic liquors with a Chelate Exchange Resin in the Presence of Iron(III)”, U.S. Pat. No. 3,998,924, Dec. 21, 1976, Jones, Kenneth C. and Wheaton, Robert M.; “Copper Recovery from Acidic Leach Liquors by Continuous ion-Exchange and Electrowinning”, Journal of Metals, Vol 31. No. 4, April 1979, pp. 19-25, Jones, Kenneth C., Pyper, Randall A.; and “Extraction of Copper, Nickel and Cobalt using Alkyl Aromatic Sulfonic Acids and Chelating Amines”, U.S. Pat. No. 4,254,087, Mar. 3, 1981, Grinstead, Robert R.
[0014] Since then there has been little commercial effort to implement IX as a primary process for concentrating and purifying copper from leach solutions.
[0015] In summary existing technology still faces major obstacles to an effective, economic and environmentally friendly process using CIX (Continuous Ion Exchange) for copper recovery from leach solution. The main problem areas which have yet to be solved include:
[0016] (1) Water availability and consumption associated with resin wash/scrub and rinsing operations. Problems in the water balance drive other problems and include (a) a build-up in water used for the leaching operation causes excess use of acid and a resulting disadvantageous dilution of copper leach concentration (which can be a severe problem in areas where rainfall is an issue in maintaining a volume balance around the leach circuit); (b) the need for extra evaporation equipment to remove the excess water from the leaching operation circuit; (c) excess water in the electrolyte which necessitates an excessive bleed of electrolyte and resulting copper and other electrolyte component losses and (d) the expense involved in generating wash/rinse waters in desert climates and the cost of treating such waters to remove undesirable mineral impurities;
[0000] (2) Inability to hold a constant volume balance in the resin elution electro-winning circuit;
[0000] (3) Maintaining a Cu:Fe ratio of metals (purity) transferred into the electrolyte similar to that obtained by SX processes;
[0000] (4) Overcoming the costs associated with maintaining a large inventory volume of resin; and
[0000] (5) Unfavorable economics associated with the use of other chemicals and chemical systems to reduce feed iron levels.
[0017] What is needed is an invention which can overcome the above limitations and shortcomings to enable control and recovery of all the copper, combined with a more environmentally friendly mode of operation. The needed system should be compatible with a multi-port valve CIX system in order to facilitate automatic operation and monitoring. The needed system should be compatible with commercially available membrane technology (nano-filtration) and iron reduction techniques to solve the above problems.
SUMMARY OF THE INVENTION
[0018] The present invention relates to a method for extracting and concentrating copper values from copper leach liquors that are economically non-viable using conventional SX-EW or known conventional configurations of IX. The invention uses a novel process scheme that is compatible and advantageous for use with a multi-port valve CIX system, a suitable resin of chelating functionality and selective for copper at low pH, a suitable membrane separation system and a novel selective scrubbing technique to control iron.
[0019] A membrane system can be used to produce wash and rinse solutions from the raffinate or feed streams and the product solutions. Suitable membranes for this purpose are described in the paper “Membrane Plant for Preconcentration of PLS”, AIME Spring meeting Cananea 1997, Harrison Western Process Technologies, Denver Colo. These membranes are engineered by Desal Osmonics, a division of GE Water & Process Technologies.
[0020] Resins employable for this invention include all those that selectively load copper (or nickel) under acidic conditions in the range, 0.8<pH<2.5. (Examples of these are Dowex 43084, Dowex 4195, CuWRAM (Purity Systems Inc.), TP 207 (Lanxess) and various solvent impregnated resins.) It is preferred to use adsorbents beads or particles with mean sizes in the range 100 microns to 700 microns.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The invention, its configuration, construction, and operation will be best further described in the following detailed description, taken in conjunction with the accompanying drawings in which:
[0022] FIG. 1 shows an overall diagram showing the general heap leach, extraction, metal recovery process;
[0023] FIG. 2 is a schematic view of a single packed column containing adsorbent ion-exchange resin beads;
[0024] FIG. 3 is a labeled process schematic showing the process stream interrelationship employing a CIX packed bed system wherein a series of packed beds are serviced by a multiple input-output valve device;
DETAILED DESCRIPTION OF THE INVENTION
[0025] The present apparatus and method can be applied to a variety of extractive industries, but is explained in relationship to a method and apparatus of extracting and concentrating copper or nickel from acidic leach liquors.
[0026] Referring to FIG. 1 is a diagram showing the overall heap leaching to copper metal recovery system. Crushed ore 11 is introduced into a heap, dump or agitation leaching operation 13 . Leach liquids contact the ore and produce a “pregnant leach solution” or PLS. The PLS is typically stored in a pond or other containment capacity storage structure, hereinafter storage 15 , prior to processing in the CIX recovery operation.
[0027] From the PLS storage 15 , the mixed solvent is introduced into one side of a CIX recovery system whose boundaries are identified with the numeral 17 . The CIX recovery system 17 physically removes the dissolved copper from the mixed solvent and produces either a copper lean or a copper depleted raffinate stream, typically to a raffinate pond or containment structure 19 . This enables the raffinate to be returned to the leaching operation 13 on an as-needed basis. In this configuration, the heap leaching operation can be performed somewhat independently of the CIX copper recovery system 17 .
[0028] As will be seen, the CIX copper recovery system 17 can be operated to either remove effectively 100% of the copper from the CIX feed stream and/or remove copper selectively from other soluble impurities to produce a pure eluate stream more concentrated in copper (to be discussed). Other economic factors, operating requirements and plant layouts may effect the desired residual copper content of the raffinate.
[0029] On the other side of the copper recovery system 17 a spent electrolyte from an other operation, is introduced to elute or desorb the copper which was removed on the left side of copper recovery system 17 .
[0030] To the right of the CIX copper recovery system 17 , strong electrolyte containing copper metals flows to one such system, known as an electro-winning system 21 . Electro-winning is commonly used in conventional copper hydro metallurgical plants and uses a spent electrolyte to take copper produced in the left side of the CIX copper recovery system 17 .
[0031] From the electro-winning system 21 , copper metal is produced. Once the copper metal is removed from the strong electrolyte, a spent electrolyte stream is supplied back to the CIX recovery system 17 . An alternative recovery system for the copper might include a crystallization step to form copper sulfate pentahydrate crystals. Further, any of the identifiable components seen in any of the Figures can be modularized and used multiply. Modularization will help to reduce cost and will enable a more efficient processing of streams whose values could change over time.
[0032] Referring to FIG. 2 , a schematic view of a column 71 is seen. Column 71 has an impermeable side wall 73 which may be glass, polymer, fiberglass, coated metal or alloy metal which is non reactive to any of the contents or liquids which may be passed through the column 71 . A packed material 75 may be beads and in the description hereafter may be resin beads having an affinity for copper. An arrow illustrates the flow through the column 71 , and the column 71 may have a liquid level 77 such that the packed material 75 may be always immersed in a liquid. The system description to follow may operate with one or a number of the columns 71 seen in FIG. 2 . These columns may be totally enclosed vessels and operate under pressure. Liquids may flow either down through the bed or up through the bed.
[0033] Referring to FIG. 3 , a detailed description of the a configuration of a copper recovery system, the details o which form the inventions contained herein. In terms of physical realizations for the equipment utilized, a multi-port valve CIX system which is highly automated is desirable. A CIX system 17 may sequence a series of packed columns through a complete ion-exchange cycle in which there are columns present which may singly or multiply occupy all stages of the cycle to be described. Typically a system having multiple columns 71 may each contain an equal amount of absorbent resin or other packed material 75 . Columns 71 may be allocated to perform the various steps of a cycle in numbers and with operational times which correspond to an optimum requirement driven by concentrations, mass transfer rates, stage of contact and solution flow rates.
[0034] A more automated system can extract and concentrate copper from acidic leach liquors more efficiently and with less down time. An optimum CIX system 17 may be able to select and utilize an optimization scheme centered upon optimum amounts of adsorbent packed material 75 , minimized total cycle time or other considerations. Cycle time may be defined as the time taken for a single column to complete a whole sequence of liquid contacts; i.e., the time for a column to pass completely through all of a series of contact zones and return to a starting point. As an overview to the actions which occur in the detailed flow schematic, to the copper containing mixed solvent, the overall steps are outlined as follows.
[0035] First, the copper containing feed solution mixed solvent contacts a chelating resin, selective for copper adsorption. Second, the chelating resin is reductively scrubbed with a reducing solution to remove ferric ion. Next, the resin is washed to displace residual scrub liquor from the resin beds. In some cases the wash and scrub operations can be combined into a single operation. Next, in a pre-strip stage a stream of a mixture of stripping rinse effluent solution, strong electrolyte and permeate is introduced, either as a mixture or in sequence from most dilute to least dilute in copper, to flush dilute solution and residual adsorbed Fe before the resin enters the actual elution or copper stripping step.
[0036] The column is then stripped or eluted with spent electrolyte obtained from the electro-winning system 21 seen in FIG. 1 or with strong acid, to cause the copper to be removed from the resin and to produce a strong electrolyte, essentially free of cations which is suitable to be sent directly to the electro-winning system 21 seen in FIG. 1 . After elution, the resin is rinsed with permeate or in metal cation free water to displace residual strong acid eluent from the resin bed and to prepare the resin bed for another adsorption step.
[0037] The aforementioned steps can be generally accomplished using a single packed column of resin or a large rotating series of resin columns (ISEP or Septor), or a series of columns serviced by manifolds and automated valves or a group of stationary columns connected to a multi-port CIX valve (IONEX). When the latter is utilized it is possible to cross connect various streams for real time flow without the necessity of storage in small tanks, containers, or reservoirs. Achieving a multi-column, simultaneous action for a series of columns, each of which are undergoing a different stage of operation can facilitate a more “analog” based optimization which is less dependent upon precise measurements. The stepwise progression of unit operation functions in this application is intended to possibly be utilized in such a device. Common or shared flow stream usage can be had by either stationary columns operated by a slowly rotating valve element, or by a series of moving columns on a carousel which move in front of different valve openings to subject the column to a different stream. Other columns may be connected to accept or transmit flows from any other column. Utilizing this scheme can provide for a reduced need for momentary storage of streams to be used later on. Further, in terms of either timing or flows, multiple columns can experience flow within a zone in sequence to increase their residence time within the zone and to provide for a further reduction in the need for storage, and can provide some advantage in the ability to blend where necessary.
[0038] Further, other connections can be had within a zone of operations for cascading output, and may occur in countercurrent fashion, from one column into an adjacent column in the same zone. For example, where an absorptive (copper loaded) column is being eluted and where a proportion of the elution is to be used by another column, the use of a series of columns connected onto a rotary switching arrangement enables the other column to use that portion of the eluted species as soon as it is eluted and without the need for storage. Further, an external switching valve arrangement can capture the first portion of a column effluent and send it to the input of another column while a second portion can be routed to another destination.
[0039] Next, the resin is conditioned with a rinse liquor to de-acidify the column and recover residual eluted copper still present in the column after it has been moved from an elution zone into a rinse zone, for example. In addition a suitable membrane nano-filter can be used under high pressure to generate metal free scrub, wash and rinse liquors, to produce the rinse and scrub liquors by squeezing water through the membrane. The use of such suitable membrane nano-filter helps to enable a more efficient water balance and assists in eliminating the need for fresh water and the fresh water conditioning which is a pre-requisite for introduction of fresh water into the system to be described.
[0040] A first suitable membrane nano-filter may typically include a membrane system to produce some of the rinse and wash feed solutions from raffinate, or PLS seen in FIG. 1 . The wash and rinse effluents may be further used as scrub liquor and may be treated in a reactor to provide a solution of sufficient reducing power to scrub the ferric ion from the resin, for example. A second suitable membrane nano-filter may typically include a membrane system to produce more rinse liquor from eluate. This second membrane nano-filter is important in maintaining a zero water balance for an electro-winning system 21 or other system, especially between the copper IX elution operation and the electrolysis step.
[0041] A third possible optional enhancement to the overall system to be described is a reactor to treat a mixture of permeate and electrolyte to be used as scrub liquor feed. One such reaction could use fine particles of copper metal in a fixed bed reactor that treats permeate for the scrub step and delivers a copper laden scrub feed at low oxidation-reduction potential.
[0042] FIG. 3 is arranged in a way to contemplate the use of a multiplicity of columns in a continuous, shared cyclic process. Each of the interconnected streams can alternatively be directed to and from a storage reservoir for current and later use, as well as for use in a continuous fashion among a set of timed, switched columns.
[0043] Referring to FIG. 3 , along a horizontal band slightly below the vertical center of the Figure, a series of rectangular blocks are used to illustrate the main steps of the process, which may be a cyclic continuous ion exchange process. They are, in order of discussion ADSORPTION 51 , SCRUB 53 , WASH 55 , PRE-STRIP 57 , ELUTION 59 , and RINSE 61 , column steps. The order has been arranged to permit the more simplistic number and extent of secondary process lines, rather than a left-to-right or right-to-left progression of column steps.
[0044] For a multi-columnar device proceeding to connect the columns with each other in a step wise fashion, the ADSORPTION 51 , SCRUB 53 , WASH 55 , PRE-STRIP 57 , ELUTION 59 , and RINSE 61 , columnar steps of FIG. 3 can be referred to as zones. Further, several columns in parallel may be located within a single zone, especially where columnar progression would benefit from a longer residence time, etc. Additionally, each zone contains a designated number of columns each of which contain an adsorbent resin with chelating functionality. The number of columns in each zone depends on the kinetics of the mass transfer for each step of the process.
[0045] Although not shown on the drawings, each stream in FIG. 3 may be expected to be controlled and timed for tighter optimization. Further, control may be had based upon measuring any characteristic of any stream, including its pressure, temperature, acidity, redox potential, conductivity, pH, and more. A multi-port valve can be used to allocate the correct number of columns to each zone and direct fluids into and out of the resin bed columns. A multi-port valve (not shown) may implement the IX process by directing flows into and out of each step in the IX cycle in a manner whereby the relative resin flow is counter-current to the fluid flows through the resin columns. In terms of an actual realization of any of the column beds, flow through the resin beds can be either upflow or downflow in any specific zone. The choice of upflow and downflow is made with a view toward maintaining the columns free of any suspended solids that may accumulate in the resin beds when operating with flow in a single direction.
[0046] FIG. 3 illustrates a copper recovery system 101 . The main flows into the system 101 include a feed PLS or mixed solvent stream 103 (which was seen in FIG. 1 flowing into the CIX recovery system 17 ). The mixed solvent stream 103 contains dissolved copper. An example of a typical feed may contain soluble copper in the range 100 mg/l to 6,000 mg/l and other (possibly unwanted) cations.
[0047] The mixed solvent feed liquor stream 103 , which contains the copper to be extracted from a mixture of other cations, passes through an ADSORPTION 51 column (or adsorption zone among a number of columns) in which copper is selectively adsorbed onto the resin beds within ADSORPTION 51 column along with some unwanted iron and perhaps other impurities. Depending upon the copper concentration, the ADSORPTION 51 column resin beds may be configured as a single, fractional or multiple columns with possibly several counter-current stages of liquid-resin contact.
[0048] The copper depleted solution, also known as raffinate stream 105 passes out of the ADSORPTION 51 column and may be returned to the leaching process if the system 101 is located within an overall leaching system as was shown in FIG. 1 . The details of the resin in any of the columns can be thought of as “resin flow” and is determined by the mass flow of copper in the mixed solvent feed liquor stream 103 and the capacity of the resin under the specific adsorption conditions. Put another way, if the resin in a given column is insufficient to handle the amount of copper to be adsorbed, the copper will “break through” and be lost into the raffinate stream 105 . Likewise, if the amount of resin in a column is significantly longer than necessary to handle the amount of copper to be absorbed, a large amount of “non working” resin will be aged from being continually exposed to the various working chemicals to which the column is exposed.
[0049] However, where a multi-port valving system having a number of columns is used, such a system effectively move the resin (in the form of a series of columns) through each zone and from zone to zone. In such a system, resin flow can be thought of as being constant through all zones. Resin residence time in each zone depends on the number of resin beds allocated to each zone.
[0050] Next, the copper loaded resin moves out of adsorption zone and into the SCRUB 53 column or zone. In the SCRUB 53 column or zone the copper loaded resin is treated with a solution of sufficient reductive potential to convert iron loaded in the ADSORPTION 51 column step from the ferric form to the ferrous form and to back-extract it into the liquid phase. Again, resin beds in the scrub step are configured in a counter-current fashion and may use multiple stages of contact where several columns are involved in a zone or in a grouping of columns undergoing the same step.
[0051] The scrub feed liquor for input to the SCRUB 53 feed step may comes from several available sources, including in order of preference, effluent stream 107 from the WASH 55 column step (because this is essentially entrained scrub liquor); a portion of effluent stream 109 from the RINSE 61 column step (since this stream contains some acidic copper solution and no Fe); and also may come from the raffinate or the mixed solvent feed liquor stream 103 . Further alternatives include a permeate (water) supply line 111 which is connected into a permeate tank 113 for temporary storage. Permeate water is water from which all minerals have been removed, and can be thought of as cation-free distilled water. Another possible source is diluted electrolyte from stream 115 . These solutions and sources may be collected in a scrub feed tank (not shown) and form a stream 117 feeding the SCRUB 53 column or zone. The scrub feed stream 117 may first pass through a mixing reactor where it is treated with a suitable reducing agent. Shown in FIG. 3 is an SO 2 REDUCTANT TANK 119 which is configured to inject sulfur dioxide as a reducing agent into the feed stream 117 .
[0052] The SCRUB 53 column step liquid effluent stream 121 contains the reduced iron (Fe2+) and is directed preferably to the adsorption zone feed liquor stream 103 or it can be sent directly into stream 105 , with the raffinate. This may depend upon the iron content of the feed stream 103 . Where the iron content is high, it may not be economic to suffer the collection and re-adsorption of iron in the ADSORPTION 51 column step even where it is possible to save more of the copper. Where the iron content is lower, a favorable equilibrium could permit re-introduction of the scrub effluent into the ADSORPTION 51 column step.
[0053] In terms of the SO 2 reducing agent, the system shown in FIG. 3 consumes little reducing agent and only that sufficient to remove the ferric ion loaded on the resin after adsorption. A preferred embodiment may also have some copper content in the SCRUB 53 column feed so that displaced ferric ion is instantly replaced by copper and not replaced by hydrogen ion in the acidic scrub. SCRUB 53 column feed may preferably be in the range of from about 1.0<pH<2.0. A bed of small copper particles can be used to pre-treat the scrub feed stream 117 so that replacement copper ions will be instantly available. This small amount of soluble copper in reduced form would favor the replacement of iron on the resin with copper from solution.
[0054] Next, the resin from the SCRUB 53 step, loaded with copper generally washed free of iron, passes to the WASH 55 column step or zone. The WASH 55 step helps remove any acidic scrub still present from the SCRUB 53 step, but more importantly helps to further remove and isolate any residual iron present from the SCRUB 53 step.
[0055] The resin exiting the SCRUB 53 column or zone enters the WASH 55 column or zone. In a preferred embodiment of this invention the steps performed in the SCRUB 53 column and WASH 55 column zones can be combined to operate as a single step. WASH 55 column feed stream 111 is obtained from the permeate tank 113 and also from diluted electrolyte from stream 115 .
[0056] Keep in mind that the process water or permeate tank 113 receives permeate from a first membrane system RO- 1 through a stream 123 and from a second membrane system RO- 2 through a stream 125 . This recovery of water helps to maintain the water balance in the ELUTION 59 column step and creates suitable quality water for use in the WASH 55 column step and the RINSE 61 column step.
[0057] Generally, the PRE-STRIP 57 column step and the RINSE 61 column step, which occur immediately prior to and immediately after ELUTION 59 column step, require water that does not contain the cations normally present in the mixed solvent feed liquor stream 103 . The membrane system permeates from membranes RO- 1 and RO- 2 already provide cation free solutions. The WASH 55 column or zone displaces residual scrub liquor from the column's resin beds. A wash feed stream 127 may be a combination of permeate from stream 111 and pre-strip effluent from stream 115 .
[0058] Effluent from the WASH 55 column step may be sent to a scrub feed tank (not shown) and eventually into stream 117 . The resin loaded with copper passes onto a PRE-STRIP 57 column water recovery step or zone. In this step, a portion of the eluate seen as a stream 129 from the ELUTION 59 column step, namely stream 131 ; and/or a portion of the effluent from the RINSE 61 column step, seen as stream 109 , is introduced to the resin beds to displace any water entrained from the WASH 55 column step. This PRE-STRIP 57 column water recovery step serves to pre-strip the remaining Fe from the resin and prevent non-adsorbed impurities and dilution from leaking into the electrolyte to be produced in the subsequent ELUTION 59 column step or zone. The liquid effluent stream 115 from the PRE-STRIP 57 column water recovery step is directed to either the second membrane system RO- 2 , recycled to stream 127 , or introduced into stream 117 . The resin loaded with copper passes from the PRE-STRIP 57 column water recovery step to the ELUTION 59 step or zone.
[0059] In the ELUTION 59 column step, also known as the stripping step or zone the copper is desorbed from the solid phase into a liquid phase by a sufficiently strong acid solution seen as supplied by stream 133 which comes from the electro-winning system 21 which was previously seen in FIG. 1 . One such eluent, typically a strongly acidic electrolyte is a stream used in the copper electro-winning system 21 seen in FIG. 1 in which the copper depleted electrolyte contains sulphuric acid and copper sulphate. The stream from the electro-winning system 21 which is depleted of copper is stream 133 , while the stream leading into the electro-winning system 21 is stream 129 , which is copper rich.
[0060] In the de-sorption process, of the ELUTION 59 column step hydrogen ion replaces copper ion on the resin bead chelating sites. The strong acid solution used in the de-sorption step is preferably recycled spent electrolyte from downstream copper electro-winning system 21 so that the complete copper recover operation can proceed in as closed loop form as possible.
[0061] This liquor channeled from the copper electro-winning system 21 contains a minimum pH 7 acidity in order to remove the copper from the adsorbent resin. A typical spent electrolyte stream 129 will contain between 80-200 grams per liter sulphuric acid and up to from about 15 to 30 grams per liter of copper ion.
[0062] The eluate in stream 129 is delivered to the downstream copper recovery step, for example copper electro-winning system 21 . A portion of this eluate flow may be first used as feed to the previously described PRE-STRIP 57 column step as previously described.
[0063] The resin within a column which has been stripped of copper and passes from the ELUTION 59 column step into a RINSE 61 column step, also known as a rinse step. In the RINSE 61 column step, metal cation free water displaces any residual eluent which is present in the columns from the ELUTION 59 column step.
[0064] The feed streams for the RINSE 61 column step are expected to come mainly from the permeate tank, stream 111 . A portion of the rinse may be provided from the ADSORPTION 51 step through a stream 135 which is shown separate and apart from stream 105 , and may be referred to as sweetened raffinate. When the first portion of stream 103 is introduced into the adsorption-ready column during the ADSORPTION 51 step, the first liquid escaping the column is both copper and iron free, and is essentially rinse feed water. It is a high quality stream having characteristics similar to the permeate from permeate tank 113 . Rather than allow this relatively pure stream to simply be dumped into the raffinate stream 105 , if some mechanism were present to draw this initial stream away from the column, and only just enough of it so that it would insure that no copper nor iron had gotten through, such a water or permeate conservation measure would be had.
[0065] Since the volume of the column used will be known, the volume of the sweetened raffinate can be selected so that a constant amount can be drawn during each ADSORPTION 51 step to insure that no contaminants will be delivered to the RINSE 61 column step via stream 135 . A conductivity meter placed in stream 135 can easily be used to detect the point at which column effluent is no longer suitable for use as a rinse material. A signal from such a meter could be employed to automatically control a valve switching arrangement. Any portion of stream 135 supplied during the RINSE 61 column step saves permeate which would otherwise be drawn through stream 111 .
[0066] The effluent from the RINSE 61 column step seen as stream 133 may be supplied as needed to three other locations as seen in FIG. 3 . Stream 109 can be supplied into stream 117 , upstream of the SCRUB 53 column step, or into the column of the PRE-STRIP 57 column step, or to the second membrane system RO- 2 to help create more permeate for stream 125 , or optionally int stream 129 .
[0067] The resin, once RINSE 61 step has been completed, is stripped of copper and rinsed and is ready to pass to the ADSORPTION 51 column step or zone at which point the resin cycle seen in FIG. 3 recommences.
[0068] In the system 101 water recovery steps are employed so as to minimize the load on the membrane systems. These are in evidence in streams 135 , 109 , 131 , and a portion of stream 115 leading to stream 127 and 117 . In addition effluents, including streams 115 , 109 , and 107 can be split on a timed or conductivity basis to further economize on the amount of permeate required for the overall process 101 .
[0069] First membrane system RO- 1 is used to generate permeate, of metal cation free acidic water. The feed to the first membrane system RO- 1 is a fractional portion of the raffinate stream 105 . The permeate created from the first membrane system RO- 1 can be used as make up for the SCRUB 53 column step but is usually sent to the permeate tank 113 for use as feed to the WASH 55 column step & RINSE 61 column step. This first membrane system RO- 1 membrane system is fed with a fraction of the raffinate stream 105 flow. Depending on the raffinate stream 105 ionic strength, the permeate recovery will range 40-60%. Membrane concentrate is returned to the stream of origin, raffinate stream 105 , via a return stream 151 but downstream of the take-off point. In addition, a return stream 153 is provided between the raffinate stream 105 and the feed PLS or mixed solvent stream 103 for any situation in which a recycle stream is needed.
[0070] The second membrane system RO- 2 is employed to remove water of dilution from the ELUTION 59 column step or zone product solution. Second membrane system RO- 2 is fed with effluents from stream 115 and a portion of stream 109 produce an acidic permeate free of metal cations for use as feed into stream 125 . Depending upon the ionic strength of the membrane feed permeate recovery will be between 45-75%. Membrane concentrate ( 17 ) is returned to the stream 129 . In the industrial application of this invention it is anticipated that permeates from the either of the membranes systems may at times be used interchangeably in either solution recovery step.
[0071] Options for use of the SO 2 reductant include the use of either an in-line injection and mixing using liquid SO 2 , or using a packed bed with solid media (such as copper solid particles). Other suitable reducing agents can also be used provided the economic benefit is stall favorable. For the SCRUB 53 column step to be effective the final oxidation-reduction potential of the solution must be less than less than the oxidation-reduction potential for converting Fe 3 + to Fe 2 + . Any excess reductive capacity in the scrub effluent can usefully be used when this effluent is returned to the feed stream. The presence of at least a stoichiometrically equivalent amount of copper (equivalent to Fe on resin) in the SCRUB 53 column step is desirable since Fe displaced from the adsorbent can then be replaced by copper in an exchange of ions.
[0072] Where a multi-column switched valve device is used, the arrangement and timing of columns allocated to adsorption can be made a function of the copper and iron mixed solvent feed liquor stream 103 . Analysis and sampling devices will be appropriately placed into the system 101 and will be based upon the storage capacity, switching controllability and other factors for each stream.
[0073] This process description is illustrative only and is not intended to limit the scope of the invention as defined by the appended claims. It will be apparent to those skilled in the art that various modifications and variations can be made in the methods of the present invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention cover modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. | A method for extracting and concentrating copper values from copper-I leach liquors that are economically non-viable using conventional SX-EW or known conventional configurations of IX. The novel process scheme is compatible and advantageous for use with a multi-port valve CIX system, a suitable membrane separation system and a selective scrubbing technique to control iron. | 8 |
This application claims priority to provisional application Ser. No. 60/047,196 dated May 20, 1997.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed to N LEU -carbamoyl and thiocarbamoyl derivatives of A82846B and N DISACC variations thereof. These derivatives are useful as antibacterials and also as starting materials from which further antibacterial compounds are prepared.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is directed to compounds of the formula ##STR1## wherein R 1 represents O or S; R 2 represents
alkyl of C 1 -C 10 ,
phenyl,
naphthyl, or
phenyl substituted by one or two substituents, each of which is independently halo, loweralkyl of C 1 -C 4 , loweralkoxy of C 1 -C 4 , benzyloxy, nitro, or ##STR2## wherein each R 2a is independently loweralkyl of C 1 -C 4 ; and R 3 represents hydrogen or --CH 2 --R 3a wherein R 3a represents
alkyl of C 1 -C 11 ,
alkyl of C 1 -C 11 --R 4 , or
R 4 -(0.sub.(0 or 1) --R 4 ) 0 or 1,
wherein each R 4 is independently phenyl or phenyl substituted by one or two substituents, each of which is independently halo, loweralkyl of C 1 -C 4 , loweralkoxy of C 1 -C 4 , or loweralkylthio of C 1 -C 4 , and pharmaceutically acceptable salts thereof.
The compounds of the present invention are prepared by reacting a parent glycopeptide of the formula ##STR3## wherein R 3 is as defined above, with an isocyanate or isothiocyanate of the formula R 1 CN--R 2 , wherein R 1 and R 2 are as defined above. This is the first step of the so-called Edman degradation, which is a two-step process for the cleavage of the N-terminal residue of a peptide or protein.
The reaction to prepare the present compounds is carried out in a polar solvent, such as water, in the presence of an organic base, such as pyridine. Generally the reaction is carried out at a temperature of about 15° C. to about 35° C. for one to five hours. The reaction is preferably carried out at a temperature from about 25° C. to 30° C. for one to two hours, in water with pyridine as the base. The reaction consumes equimolar amounts of the reactants but a slight excess of the isocyanate or isothiocyanate is preferred. The product is separated and purified if desired in conventional procedures. When it is desired, a salt can be prepared in standard procedures.
The following examples illustrate the preparation of the compounds of the present invention.
PREPARATION OF COMPOUND OF EXAMPLE 22
N DISACC -(p-(p-Chlorophenyl)benzyl)A82846B trihydrochloride (100.0 mg, 0.0526 mmol) was dissolved in 10 ml H 2 O-pyridine (1:1 v/v) and treated with phenyl isothiocyanate (0.010 ml, 0.083 mmol). The resulting mixture was stirred at room temperature for 1 hour at which time HPLC analysis indicated complete consumption of the starting material. The reaction mixture was concentrated in vacuo and the crude product was purified by preparative HPLC to give 76.6 mg (76% yield) of N LEU -(phenylthiocarbamoyl)-N DISACC -(p-(p-chlorophenyl)benzyl) A82846B. FAB-MS: calc. For C 93 H 102 Cl 3 N 11 O 26 S 1925.5, obtained 1928.5 (M+3).
PREPARATION OF COMPOUND OF EXAMPLE 23
A82846B triacetate (270 mg, 0.157 mmol) was dissolved in 30 ml H 2 O-pyridine (1:1 v/v) and treated with phenyl isocyanate (0.030 ml, 0.277 mmol). The resulting mixture was stirred at room temperature for 1 hour at which time HPLC analysis indicated complete consumption for the starting material. The reaction mixture was concentrated in vacuo and the crude product was purified by preparative HPLC to give 62.5 mg (23% yield) of N LEU -(phenylcarbamoyl)-A82846B. FAB-MS: Calc. For C 80 H 93 Cl 2 N 11 O 27 1709.6, obtained 1712.1 (M+3).
The HPLC procedures reported in these examples were as follows:
Analytical: Reactions were monitored by analytical HPLC using a Waters C 18 μBondapak or Novapak C 18 column (3.9×300 mm) and UV detection at 280 nm. Elution was accomplished with a linear gradient of 5% CH 3 CN-95% buffer to 80% CH 3 CN-20% buffer over 30 minutes. The buffer used was 0.5% triethylamine in water, adjusted to pH 3 with H 3 PO 4 .
Preparative: Crude reaction mixtures were purified by preparative HPLC using a Waters C 18 Nova-Pak column (40×300 mm) and UV detection at 280 nm. Elution was accomplished with a linear gradient of 5% CH 3 CN-95% buffer to 80% CH 3 CN-20% buffer over 30 minutes. The buffer used was 0.5% triethylamine in water, adjusted to pH 3 with H 3 PO 4 . The desired fractions were subsequently desalted with a Waters C 18 Sep-Pak (35 cc) followed by lyophilization.
Compounds were desalted as follows. A Waters Sep-Pak cartridge was pre-wet with methanol (2-3 column volumes) then conditioned with water (2-3 column volumes). The sample, dissolved in a minimum volume of water, was loaded onto the Sep-Pak column which was then washed with water (2-3 column volumes) to remove the unwanted salts. The product was then eluted with an appropriate solvent system, typically 1:1 CH 3 CN/H 2 O, CH 3 CN, and/or methanol. The organic solvent component was removed in vacuo and the resulting aqueous solution lyophilized to give the final product.
Representative compounds of the present invention are listed in the following table:
TABLE I__________________________________________________________________________Ex Analytical# Name FAB-MS M + X HPLC, min__________________________________________________________________________ 1 N.sup.LEU - 1728.5 3 18.2* (PHENYLTHIOCARBAMOYL)A82846B 2 N.sup.LEU -(PHENYLTHIOCARBAMOYL)- 1852.3 3 21.4* N.sup.DISACC -(p-CHLOROBENZYL)A82846B 3 N.sup.LEU -(PHENYLTHIOCARBAMOYL)- 1911.0 3 23.6* N.sup.DISACC -(p-PHENOXYBENZYL)- A82846B 4 N.sup.LEU -(PHENYLTHIOCARBAMOYL)- 1894.5 3 23.2* N.sup.DISACC -(p-PHENYLBENZYL)A82846B 5 N.sup.LEU -(1-NAPHTHYLTHIOCARBAMOYL) 1778.5 3 19.8* A82846B 6 N.sup.LEU -(1- 1902.5 3 15.4* NAPHTHYLTHIOCARBAMOYL)-N.sup.DISACC - (p-CHLOROBENZYL)A82846B 7 N.sup.LEU -(1- 1960.6 3 17.1* NAPHTHYLTHIOCARBAMOYL)-N.sup.DISACC - (p-PHENOXYBENZYL)A82846B 8 N.sup.LEU -((p-CHLOROPHENYL)- 1763.0 4 20.5* THIOCARBAMOYL)A82846B 9 N.sup.LEU -((p-METHOXYPHENYL)- 1757.3 2 21.0* THIOCARBAMOYL)A82846B10 N.sup.LEU -((p-CHLOROPHENYL)- 1944.3 3 26.9* THIOCARBAMOYL)-N.sup.DISACC -(p- PHENOXYBENZYL)A82846B11 N.sup.LEU -((p-METHOXYPHENYL)- 1940.3 3 26.0* THIOCARBAMOYL)-N.sup.DISACC -(p- PHENOXYBENZYL)A82846B12 N.sup.LEU -((p-CHLOROPHENYL)- 1887.5 4 24.8* THIOCARBAMOYL)-N.sup.DISACC -(p- CHLOROBENZYL)A82846B13 N.sup.LEU -((p-METHOXYPHENYL)- 1882.5 3 25.2* THIOCARBAMOYL)-N.sup.DISACC -(p- CHLOROBENZYL)A82846B14 N.sup.LEU -((p-NITROPHENYL)- 1774.0 3 19.1* THIOCARBAMOYL)A82846B15 N.sup.LEU -((p-(DIMETHYLAMINO)- 1771.4 3 17.6* PHENYL)THIOCARBAMOYL)A82846B16 N.sup.LEU -((p-(BENZYLOXY)PHENYL)- 1834.4 3 23.3* THIOCARBAMOYL)A82846B17 N.sup.LEU -((p-n-BUTYLPHENYL)- 1784.4 3 17.0* THIOCARBAMOYL)A82846B18 N.sup.LEU -((p-n-BUTYLPHENYL)- 1966.5 3 21.4** THIOCARBAMOYL)-N.sup.DISACC -(p- PHENOXYBENZYL)A82846B19 N.sup.LEU -((p-(DIMETHYLAMINO)- 1953.3 3 17.1** PHENYL)THIOCARBAMOYL)-N.sup.DISACC - (p-PHENOXYBENZYL)A82846B20 N.sup.LEU -((p-(BENZYLOXY)PHENYL)- 2016.3 3 21.1** THIOCARBAMOYL)-N.sup.DISACC -(p- PHENOXYBENZYL)A82846B21 N.sup.LEU -(PHENYLTHIOCARBAMOYL)- 1874.6 3 19.0** N.sup.DISACC -(p-n-BUTYLBENZYL)- A82846B22 N.sup.LEU -(PHENYLTHIOCARBAMOYL)- 1928.5 3 20.3** N.sup.DISACC -(p-(p-CHLOROPHENYL)- BENZYL)A82846B23 N.sup.LEU -(PHENYLCARBAMOYL)A82846B 1712.1 3 13.8**24 N.sup.LEU -(PHENYLCARBAMOYL)-N.sup.DISACC - 1894.2 3 18.9** (p-PHENOXYBENZYL)A82846B25 N.sup.LEU -(n-DECYLTHIOCARBAMOYL)- 1792.4 3 N.A. A82846B__________________________________________________________________________ *Waters C.sub.18 NovaPak column **Waters C.sub.18 μBondapak
The compounds of the present invention are useful for the treatment of bacterial infections. Therefore, in another embodiment, the present invention is directed to a method for controlling a bacterial infection in a host animal, typically a warm-blooded animal, which comprises administering to the host animal an effective, antibacterial amount of a compound of the present invention. In this embodiment, the compounds can be used to control and treat infections due to various bacteria, but especially gram-positive bacteria. In a preferred embodiment, the compounds are used to control and treat infections due to bacteria resistant to existing antibacterials. For example, certain bacteria are resistant to methicillin, and yet others are resistant to vancomycin and/or teicoplanin. The present compounds provide a technique for controlling and treating infections due to such resistant bacterial species.
In carrying out this embodiment of the invention, the compounds of the present invention can be administered by any of the conventional techniques, including the oral route and parenteral routes such as intravenous and intramuscular. The amount of compound to be employed is not critical and will vary depending on the particular compound employed, the route of administration, the severity of the infection, the interval between dosings, and other factors known to those skilled in the art. In general, a dose of from about 0.5 to about 100 mg/kg will be effective; and in many situations, lesser doses of from about 0.5 to about 50 mg/kg will be effective. A compound of the present invention can be administered in a single dose, but in the known manner of antibacterial therapy, a compound of the present invention is typically administered repeatedly over a period of time, such as a matter of days or weeks, to ensure control of the bacterial infection.
Also in accordance with known antibacterial therapy, a compound of the present invention is typically formulated for convenient delivery of the requisite dose. Therefore, in another embodiment, the present invention is directed to a pharmaceutical formulation comprising a compound of the present invention, in combination with a pharmaceutically-acceptable carrier. Such carriers are well known for both oral and parenteral routes of delivery. In general, a formulation will comprise a compound of the present invention in a concentration of from about 0.1 to about 90% by weight, and often from about 1.0 to about 3%.
The antibacterial efficacy of the present compounds is illustrated by Table II. The minimal inhibitory concentrations (MICs) were determined using a standard broth micro-dilution assay.
TABLE II__________________________________________________________________________Antibacterial Activity, Minimal InhibitoryConcentration (MIC) Against Various Organisms*__________________________________________________________________________Ex SA SA SA SH SH SE SPY SPN# RESISTANT SENSITIVE 446 489 447 105 415 270 C203 P1__________________________________________________________________________ 1 >128 16 8 4 8 64 >64 8 2 2 2 128 3.4 2 2 2 8 16 4 0.125 0.25 3 16 1.7 4 2 1 2 2 1 ≦.06 4 14 4 2 0.125 1 2 1 0.5 ≦0.06 0.125 5 >128 9.5 8 >64 8 64 >64 32 0.5 1 6 128 5 2 16 4 4 8 64 ≦0.06 ≦0.06 7 19 3 4 2 1 4 2 0.5 0.25 ≦0.06 8 >128 8 2 2 4 16 64 8 9 >128 21 8 4 8 32 32 1610 9.5 1.7 4 2 2 1 2 211 38 2.6 4 2 2 1 2 212 128 3.5 4 1 1 2 4 1 ≦0.06 ≦0.0613 >128 3.5 4 2 2 4 8 2 ≦0.06 ≦0.0614 >128 3.5 2 2 4 16 32 4 ≦0.06 0.2515 >128 24 8 4 16 >64 >64 16 0.25 0.2516 >128 7 1 0.5 1 8 64 4 ≦0.06 0.12517 >128 6.1 2 1 1 4 32 2 0.25 ≦0.0618 4.7 1.7 2 2 2 2 2 2 0.25 219 19 2.6 2 2 2 2 4 2 0.25 220 9.5 5.6 4 2 2 2 2 1 ≦0.06 421 32 2.622 6.7 2.6 2 1 1 1 2 0.5 ≦.06 ≦.0623 >128 5.3 4 1 4 0.5 64 424 16 0.87 2 1 1 0.25 1 1__________________________________________________________________________ABBREVIATIONS ORGANISMRESISTANT Enterococcus faecium and faecalis (geometric mean of 4-6 isolates)SENSITIVE Enterococcus faecium and faecalis (geometric mean of 4-6 isolates)SA446 Staphylococcus aureus 446SA489 Staphylococcus aureus 489SA447 Staphylococcus aureus 447SH 105 Staphylococcus haemolyticus 105SH 415 Staphylococcus haemolyticus 415SE 270 Staphylococcus epidermidis 270SPY C203 Streptococcus pyogenes C203SPN P1 Streptococcus pneumoniae P1
The N LEU -thiocarbamoyl compounds of the present invention can also be employed as starting materials to other antibacterial compounds. This use is illustrated by the following reaction sequence: ##STR4## Thus, a present compound is treated with an organic acid, preferably trifluoroacetic acid, in a non-polar solvent, and at a temperature of from about 0° C. to 35° C. This treatment, the second step of an Edman degradation, results in the loss of the leucine group including the thiocarbamoyl substituent. The resulting "hexapeptides" exhibit antibacterial activity and can be employed as described above for the present compounds.
The hexapeptide can thereafter be reductively alkylated to introduce an alkyl group on the amine freed up by the preceding process, the "N 1 " a amine. Alkylation is achieved by reacting the hexapeptide with an aldehyde to form a Schiff's base, which is then reduced to obtain the N 1 -alkylhexapeptide. Both reactions are carried out in a polar solvent, such as DMF, and at temperatures of 0-100° C., preferably 60-70° C. The preferred reducing agent is sodium cyanoborohydride. In one embodiment, the reducing agent is added at the same time as the hexapeptide and aldehyde. The resulting N 1 -alkylated hexapeptides are useful as antibacterials and can be employed as described above for compounds of the present invention. | The present invention is directed to N LEU -carbamoyl and thiocarbamoyl derivatives of A82846B and N DISACC variations thereof. These derivatives are useful as antibacterials and also as starting materials from which further antibacterial compounds are prepared. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application Ser. No. 13/843,289, filed Mar. 15, 2013, now pending, the disclosures of which are hereby incorporated by reference in their entirety.
FIELD OF THE INVENTION
[0002] The invention relates to pharmaceutical compositions, methods of production, analytical methods, and methods of use for secretoglobin proteins, including SCGB1A1 (CC10), SCGB3A1, and SCGB3A2. Novel physiologic roles and therapeutic uses for these secretoglobins have been identified. Specifically, the present invention relates to novel methods of use for rhCC10, rhSCGB3A2, and rhSCGB3A1 in preventing or delaying hospitalizations due to severe respiratory exacerbations up to 10 months after a course of treatment. The present also relates to novel methods of production and pharmaceutical compositions of rhSCGB3A2 that is stable and possesses anti-inflammatory properties. More specifically, the invention further provides a method to prevent severe respiratory exacerbations by administering rhCC10. The invention further provides a method for treating bronchiectasis and preventing exacerbations of bronchiectasis by administering rhSCGB3A2. Even more specifically, the invention provides a method for reversing airway remodeling in chronic lung diseases and preventing airway remodeling in acute lung injuries by administering rhCC10, rhSCGB3A2, or rhSCGB3A1. Even more specifically, these secretoglobins modify airway remodeling indirectly by restoring normal numbers of Clara cells and their associated structures, termed neuro-epithelial bodies (aka NEBs) or neuroendocrine cell clusters (aka NECs) that are identified by their immunoreactivity to anti-CGRP1 antibodies, in the airway epithelium. The Clara cells and other CGRP1+ cells, then secrete these secretoglobins and other components of the normal mucosal milieu, contributing to homeostasis and normal functioning of the respiratory mucosa and epithelium that is then more resistant to inhaled challenges without experiencing severe exacerbations.
BACKGROUND OF THE INVENTION
[0003] Natural human Clara Cell 10 kDa protein (CC10), also known as uteroglobin, Clara cell 16 kDa protein (CC16), Clara cell secretory protein (CCSP), blastokinin, urine protein-1, and secretoglobin 1A1 (SCGB1A1), is one of a family of related proteins called secretoglobins believed to exist in all vertebrate animals. There are two additional secretoglobins that are also expressed at very high levels in the respiratory tract, called SCGB3A1 and SCGB3A2 (Porter, 2002). These three proteins; SCGB1A1, SCGB3A1, and SCGB3A2, are herein referred to as “respiratory secretoglobins.” Table 1 shows Genebank loci and amino acid sequences for each respiratory secretoglobin.
[0000]
TABLE 1
Respiratory secretoglobin proteins
Genebank
Protein
locus
Amino acid sequence
SCGB1A1
BC004481
EICPSFQRVIETLLMDTPSSYEAAMELFSPD
(CC10)
QDMREAGAQLKKLVDTLPQKPRESIIKLMEK
IAQSSLCN
SCGB3A1
NP_443095
AAFLVGSAKPVAQPVAALESAAEAGAGTLAN
PLGTLNPLKLLLSSLGIPVNHLIEGSQKCVA
ELGPQAVGAVKALKALLGALTVFG
SCGB3A2
AAQ89338
ATAFLINKVPLPVDKLAPLPLDNILPFMDPL
KLLLKTLGISVEHLVEGLRKCVNELGPEASE
AVKKLLEALSHLV
[0004] The primary source of respiratory secretoglobins in mammals is the pulmonary and tracheal epithelia, especially the non-ciliated bronchiolar airway epithelial cells (primarily Clara cells), and they are very abundant locally-produced proteins in the extracellular fluids of the adult lung. They are also secreted in the nasal epithelia. Thus, respiratory secretoglobins are highly expressed in both the upper and lower respiratory tracts; the upper respiratory tract includes the nasal passages and sinuses and the lower respiratory tract includes the trachea, bronchi, and alveoli of the lungs. A significant amount of respiratory secretoglobins are also present in serum and urine, which is largely derived from pulmonary sources. SCGB3A1 is also expressed in the stomach, heart, small intestine, uterine and mammary glands, and SCGB3A2 is expressed at a low level in the thyroid (Porter, 2002). CC10 is also produced by reproductive tissues (uterus, seminal vesicles), exocrine glands (prostate, mammary gland, pancreas), endocrine glands (thyroid, pituitary, adrenal, and ovary) and by the thymus and spleen (Mukherjee, 1999; Mukherjee, 2007). The major recoverable form of human CC10 in vivo is a homodimer, comprised of two identical 70 amino acid monomers, with an isoelectric point of 4.8. Its molecular weight is 15.8 kDa, although it migrates on SDS PAGE at an apparent molecular weight of about 10 kDa. The monomers are arranged in an antiparallel configuration, with the N-terminus of one adjacent to the C-terminus of the other, and in the fully-oxidized form of the dimer, the monomers are connected by two disulfide bonds (Mukherjee, 1999). However, the in vivo molecular form (monomer, dimer, or other complex) of SCGB3A2 in human samples has not yet been characterized. All three respiratory secretoglobins may be made by synthetic (Nicolas, 2005) or recombinant methods (Mantile, 1993), although there have been no reports to date describing the successful synthesis of human SCGB3A1 and SCGB3A2 and the biochemical characterization of these proteins in vitro.
[0005] CC10 is an anti-inflammatory and immunomodulatory protein that has been characterized with respect to various interactions with other proteins, receptors and cell types (reviewed in Mukherjee, 2007, Mukherjee, 1999, and Pilon, 2000). Lower levels of CC10 protein or mRNA have been found in various tissue and fluid samples for a number of clinical conditions characterized by some degree of inflammation including asthma (Lensmar, 2000; Shijubo, 1999; Van Vyve, 1995), pneumonia (Nomori, 1995), bronchiolitis obliterans (Nord, 2002), sarcoidosis (Shijubo, 2000), and in patients suffering from chronic rhinitis with recurrent sinusitis and nasal polyposis (Liu, 2004). Pulmonary epithelial cells, the body's primary source for endogenous CC10, are often adversely affected in these conditions, depleted or even ablated (Shijubo, 1999).
[0006] CC10 knockout (KO) mice have been important in characterizing the role of CC10 in pulmonary homeostasis, reproduction, and certain types of renal disease. There are two strains of CC10 KO mice, each with different genetic knockout constructs and different parental mouse strains. One knockout strain exhibits several extreme phenotypes, including systemic inflammation, poor reproductive capability (small litter sizes), and a lethal renal phenotype resembling human IgA nephropathy (Zhang, 1997; Zheng, 1999). The other knockout strain does not possess these extreme phenotypes and is more viable, enabling a greater number of experiments to be performed (Stripp, 1997). Both strains of CC10 KO mice share much greater sensitivity and significantly heightened inflammatory responses to pulmonary challenges in models of asthma, pulmonary fibrosis and carcinogenesis, bacterial and viral infections, and oxygen and ozone exposures (Plopper, 2006; Lee, 2006; Yang, 2004; Wang, 2003; Harrod, 2002; Chen, 2001; Wang, 2001; Hayashida, 2000; Harrod, 1998). Restoration of CC10 function in these knockout mice using recombinant human CC10 (rhCC10) has been shown to mitigate the exaggerated pulmonary inflammatory responses in short term challenge models with endpoints of up to 7 days (Chen, 2001; Wang, 2003). Most relevant to the invention, both strains share an airway epithelial phenotype characterized by significantly decreased numbers of Clara cells and associated structures called neuro-epithelial bodies (NEBs; Castro, 2000) or neuro-endocrine cell clusters (NECs; Hong, 2001; Reynolds, 2000), as identified by positive staining with calcitonin-gene related protein 1 (CGRP1). These 2-10 fold deficiencies in Clara cells and associated structures in the airways arise in the absence of any type of injury in these KO mice.
[0007] Premature infants who experience respiratory distress syndrome (RDS) are deficient in native CC10. In a clinical trial, a single dose of rhCC10 was administered on the day of birth and mediated potent short-term anti-inflammatory effects for 3-7 days in the lungs. Pharmacokinetic analyses showed that surplus CC10 was cleared within 48 hours of the single dose administered. Despite the anti-inflammatory effects, rhCC10 did not prevent development of neonatal bronchopulmonary dysplasia (BPD) (Levine, 2005), as defined by clinical parameters, including 1) opacity of chest X-ray at 28 days after birth or 2) use of supplemental oxygen at 36 weeks of postmenstrual age (PMA). Nor did rhCC10 reduce the time in the hospital or the number of days on the ventilator, despite the significant reductions in indices of pulmonary inflammation observed in tracheal aspirate fluids (TAF). There were no differences between the placebo, low dose and high dose treatment groups the 12 month endpoint, as stated in Levine et al. (2005).
[0008] Premature infants with BPD are predisposed towards experiencing frequent and severe respiratory exacerbations and their re-hospitalization rates in the first 1-2 years of life are high. Severe respiratory exacerbations are characterized by shortness of breath, labored breathing, nasal and chest congestion, overproduction of mucus, and sometimes respiratory distress. Severe respiratory exacerbations occur when patients encounter environmental exposures and infections through inhalation of dust, smoke, allergens, pollutants, chemicals, bacteria, fungi, and viruses.
[0009] Many types of patients with chronic diseases of the respiratory, gastrointestinal, urogenital tracts are susceptible to severe exacerbations when exposed to an environmental trigger. Likewise, patients with immunologic diseases, including autoimmune and allergic diseases, are also susceptible to severe exacerbations when exposed to an environmental trigger. Severe or acute exacerbations are considered frequent when they occur more than 3 times per year in a patient. Even patients who do not have a chronic disease, but who experience acute lung injury (ALI), are susceptible to frequent and severe acute respiratory episodes, resembling severe respiratory exacerbations, following the injury. Environmental irritants that trigger exacerbations include, but are not limited to, dust, particulates, smoke, allergens, pollutants, chemicals, contaminants, bacteria, fungi, and viruses may be inhaled, ingested, swallowed, absorbed through the skin, or otherwise come in contact topically with a wet mucosal surface of the patient's body.
OBJECTS OF THE INVENTION
[0010] The foregoing provides a non-exclusive list of the objectives achieved by the present invention:
[0011] It is a primary object of the invention to administer a secretoglobin to prevent hospitalization due to a severe exacerbation of an underlying or chronic disease for up to 10 months after the secretoglobin is administered.
[0012] It is a further object of the invention to administer a respiratory secretoglobin to prevent hospitalization due to a severe exacerbation of an underlying or chronic respiratory disease for up to 10 months after the secretoglobin is administered.
[0013] It is a further object of the invention to administer rhCC10 to prevent hospitalization due to a severe exacerbation of an underlying or chronic respiratory disease for up to 10 months after the secretoglobin is administered.
[0014] It is a further object of the invention to administer rhSCGB3A2 to prevent hospitalization due to a severe exacerbation of an underlying or chronic respiratory disease for up to 10 months after the secretoglobin is administered.
[0015] It is a further object of the invention to administer rhSCGB3A1 to prevent hospitalization due to a severe exacerbation of an underlying or chronic respiratory disease for up to 10 months after the secretoglobin is administered.
[0016] It is a further object of the invention to administer a secretoglobin to prevent hospitalization due to a severe exacerbation of an underlying or chronic disease for at least one month after the secretoglobin is administered.
[0017] It is a further object of the invention to administer a respiratory secretoglobin to prevent hospitalization due to a severe exacerbation of an underlying or chronic respiratory disease for at least one month after the secretoglobin is administered.
[0018] It is a further object of the invention to administer rhCC10 to prevent hospitalization due to a severe exacerbation of an underlying or chronic respiratory disease for at least one month after the secretoglobin is administered.
[0019] It is a further object of the invention to administer rhSCGB3A2 to prevent hospitalization due to a severe exacerbation of an underlying or chronic respiratory disease for at least one month after the secretoglobin is administered.
[0020] It is a further object of the invention to administer rhSCGB3A1 to prevent hospitalization due to a severe exacerbation of an underlying or chronic respiratory disease for at least month after the secretoglobin is administered.
[0021] It is a further object of the invention to administer a secretoglobin to increase the time interval from one severe exacerbation to the next, in patients who typically experience recurrent exacerbations of chronic diseases.
[0022] It is a further object of the invention to increase the time interval from one severe exacerbation to the next, for up to 10 months after a dose or course of respiratory secretoglobin therapy, in patients who experience recurrent exacerbations of chronic diseases.
[0023] It is a further object of the invention to administer a respiratory secretoglobin to increase the time interval from one severe respiratory exacerbation to the next, in patients who experience recurrent exacerbations of chronic respiratory diseases.
[0024] It is a further object of the invention to administer a respiratory secretoglobin to prevent a severe acute respiratory episode resembling an exacerbation in a patient who experienced an acute lung injury but was not diagnosed with a chronic respiratory disease prior to the injury.
[0025] It is a further object of the invention to administer a respiratory secretoglobin to prevent a severe exacerbation after exposure to an inhaled irritant capable of triggering an exacerbation, in a susceptible patient with a chronic respiratory disease.
[0026] It is a further object of the invention to administer a secretoglobin to increase the time interval from one severe autoimmune exacerbation to the next, in patients who experience recurrent exacerbations of chronic autoimmune diseases.
[0027] It is a further object of the invention to administer a respiratory secretoglobin to increase the time interval from one severe respiratory exacerbation to the next, in patients who experience frequent exacerbations of chronic respiratory diseases.
[0028] It is a further object of the invention to administer a respiratory secretoglobin to increase the time interval from one severe autoimmune exacerbation to the next, in patients who experience frequent exacerbations of chronic autoimmune diseases.
[0029] It is a further object of the invention to administer the secretoglobin during or after the previous exacerbation in order to prevent the next exacerbation.
[0030] It is a further object of the invention to administer the secretoglobin by intravenous injection, intratracheal instillation, inhalation, intranasal instillation, orally, sublingually, or by anal or vaginal cream, gel, or suppository.
[0031] It is a secondary object of the invention to administer a respiratory secretoglobin to increase numbers of non-ciliated secretory epithelial cells and thereby rehabilitate mucosal tissues.
[0032] It is a further object of the invention to administer a respiratory secretoglobin to increase numbers of non-ciliated secretory epithelial cells in the respiratory tract, including the upper and lower respiratory tract, and thereby rehabilitate respiratory mucosal tissues and airways.
[0033] It is a further object of the invention to administer a respiratory secretoglobin to increase numbers of Clara cells in the respiratory tract and thereby rehabilitate respiratory mucosal tissues and airways.
[0034] It is a further object of the invention to administer a respiratory secretoglobin to increase numbers of NEBs and NECs in the respiratory tract and thereby rehabilitate respiratory mucosal tissues and airways.
[0035] It is a further object of the invention to administer a respiratory secretoglobin to increase the amount of one or more native respiratory secretoglobins circulating in the blood.
[0036] It is a further object of the invention to administer a respiratory secretoglobin to increase the amount of one or more native respiratory secretoglobins found in respiratory airway lining fluids (ALF) of the nasal passages, trachea, or lungs and/or sputum or induced sputum.
[0037] It is a further object of the invention to administer a respiratory secretoglobin to increase numbers of secretoglobin-secreting cells in the respiratory tract and thereby rehabilitate respiratory mucosal tissues and airways.
[0038] It is a further object of the invention to administer a respiratory secretoglobin to increase numbers of CC10-secreting cells in the respiratory tract and thereby rehabilitate respiratory mucosal tissues and airways.
[0039] It is a further object of the invention to administer a respiratory secretoglobin to increase numbers of SCGB3A2-secreting cells in the respiratory tract and thereby rehabilitate respiratory mucosal tissues and airways.
[0040] It is a further object of the invention to administer a respiratory secretoglobin to increase numbers of SCGB3A1-secreting cells in the respiratory tract and thereby rehabilitate respiratory mucosal tissues and airways.
[0041] It is a further object of the invention to administer a respiratory secretoglobin to increase numbers of CC10-secreting epithelial cells in the female urogenital tract and thereby rehabilitate vaginal mucosal tissues.
[0042] It is a further object of the invention to administer a respiratory secretoglobin to increase numbers of CC10-secreting epithelial cells in the gastrointestinal tract, including the mouth, throat, esophagus, stomach, pancreas, the bile duct, the upper and lower intestines, and the colon, and thereby rehabilitate gastrointestinal mucosal tissues.
[0043] It is a further object of the invention to provide a pharmaceutical composition of human SCGB3A2 with a non-native N-terminus of ATA.
[0044] It is a further object of the invention to provide a pharmaceutical composition of human SCGB3A2 with an isoelectric point of 6.7.
[0045] It is a further object of the invention to provide a pharmaceutical composition of human SCGB3A2 with an isoelectric point of 6.3.
[0046] It is a further object of the invention to provide a pharmaceutical composition of human SCGB3A2 with a combination of isoforms with isoelectric points of 6.3 and 6.7.
[0047] It is a further object of the invention to provide a pharmaceutical composition of recombinant human SCGB3A2 that is synthesized as a fusion with another protein.
[0048] It is a further object of the invention to provide a pharmaceutical composition of recombinant human SCGB3A2 that is synthesized as a fusion with an ubiquitin-like protein.
[0049] It is a further object of the invention to administer a human respiratory secretoglobin to delay or prevent an exacerbation of bronchiectasis in a patient diagnosed with bronchiectasis.
[0050] It is a further object of the invention to administer a human respiratory secretoglobin to delay or prevent an exacerbation of pulmonary fibrosis in a patient diagnosed with a type of pulmonary fibrosis.
[0051] It is a further object of the invention to administer a human respiratory secretoglobin to delay or prevent an exacerbation of cystic fibrosis in a patient diagnosed with a type of cystic fibrosis.
[0052] It is a further object of the invention to administer a human respiratory secretoglobin to delay or prevent an exacerbation of COPD in a patient diagnosed with COPD.
[0053] It is a further object of the invention to administer a human respiratory secretoglobin to delay or prevent an exacerbation of chronic bronchitis in a patient diagnosed with chronic bronchitis.
[0054] It is a further object of the invention to administer a human respiratory secretoglobin to delay or prevent an exacerbation of emphysema in a patient diagnosed with emphysema.
[0055] It is a further object of the invention to administer a human respiratory secretoglobin to delay or prevent an exacerbation of asthma in a patient diagnosed with asthma.
[0056] It is a further object of the invention to administer a human respiratory secretoglobin to delay or prevent an exacerbation of BPD in a patient diagnosed with BPD.
[0057] It is a further object of the invention to administer a human respiratory secretoglobin to delay or prevent an exacerbation of meconium aspiration syndrome (MAS) in a patient diagnosed with MAS.
[0058] It is a further object of the invention to administer human CC10 to delay or prevent an exacerbation of bronchiectasis in a patient diagnosed with bronchiectasis.
[0059] It is a further object of the invention to administer human CC10 to delay or prevent an exacerbation of pulmonary fibrosis in a patient diagnosed with a type of pulmonary fibrosis.
[0060] It is a further object of the invention to administer human CC10 to delay or prevent an exacerbation of cystic fibrosis in a patient diagnosed with a type of cystic fibrosis.
[0061] It is a further object of the invention to administer human CC10 to delay or prevent an exacerbation of COPD in a patient diagnosed with COPD.
[0062] It is a further object of the invention to administer human CC10 to delay or prevent an exacerbation of chronic bronchitis in a patient diagnosed with chronic bronchitis.
[0063] It is a further object of the invention to administer human CC10 to delay or prevent an exacerbation of emphysema in a patient diagnosed with emphysema.
[0064] It is a further object of the invention to administer human CC10 to delay or prevent an exacerbation of asthma in a patient diagnosed with asthma.
[0065] It is a further object of the invention to administer human CC10 to delay or prevent an exacerbation of BPD in a patient diagnosed with BPD.
[0066] It is a further object of the invention to administer human CC10 to delay or prevent an exacerbation of meconium aspiration syndrome (MAS) in a patient diagnosed with MAS.
[0067] It is a further object of the invention to administer human SCGB3A2 to delay or prevent an exacerbation of bronchiectasis in a patient diagnosed with bronchiectasis.
[0068] It is a further object of the invention to administer human SCGB3A2 to delay or prevent an exacerbation of pulmonary fibrosis in a patient diagnosed with a type of pulmonary fibrosis.
[0069] It is a further object of the invention to administer human SCGB3A2 to delay or prevent an exacerbation of cystic fibrosis in a patient diagnosed with a type of cystic fibrosis.
[0070] It is a further object of the invention to administer human SCGB3A2 to delay or prevent an exacerbation of COPD in a patient diagnosed with COPD.
[0071] It is a further object of the invention to administer human SCGB3A2 to delay or prevent an exacerbation of chronic bronchitis in a patient diagnosed with chronic bronchitis.
[0072] It is a further object of the invention to administer human SCGB3A2 to delay or prevent an exacerbation of emphysema in a patient diagnosed with emphysema.
[0073] It is a further object of the invention to administer human SCGB3A2 to delay or prevent an exacerbation of asthma in a patient diagnosed with asthma.
[0074] It is a further object of the invention to administer human SCGB3A2 to delay or prevent an exacerbation of BPD in a patient diagnosed with BPD.
[0075] It is a further object of the invention to administer human SCGB3A2 to delay or prevent an exacerbation of meconium aspiration syndrome (MAS) in a patient diagnosed with MAS.
[0076] It is a further object of the invention to administer human SCGB3A1 to delay or prevent an exacerbation of bronchiectasis in a patient diagnosed with bronchiectasis.
[0077] It is a further object of the invention to administer human SCGB3A1 to delay or prevent an exacerbation of pulmonary fibrosis in a patient diagnosed with a type of pulmonary fibrosis.
[0078] It is a further object of the invention to administer human SCGB3A1 to delay or prevent an exacerbation of cystic fibrosis in a patient diagnosed with a type of cystic fibrosis.
[0079] It is a further object of the invention to administer human SCGB3A1 to delay or prevent an exacerbation of COPD in a patient diagnosed with COPD.
[0080] It is a further object of the invention to administer human SCGB3A1 to delay or prevent an exacerbation of chronic bronchitis in a patient diagnosed with chronic bronchitis.
[0081] It is a further object of the invention to administer human SCGB3A1 to delay or prevent an exacerbation of emphysema in a patient diagnosed with emphysema.
[0082] It is a further object of the invention to administer human SCGB3A1 to delay or prevent an exacerbation of asthma in a patient diagnosed with asthma.
[0083] It is a further object of the invention to administer human SCGB3A1 to delay or prevent an exacerbation of BPD in a patient diagnosed with BPD.
[0084] It is a further object of the invention to administer human SCGB3A1 to delay or prevent an exacerbation of meconium aspiration syndrome (MAS) in a patient diagnosed with MAS.
SUMMARY OF THE INVENTION
[0085] Secretoglobin proteins that are expressed in the respiratory tract facilitate development of Clara cells and other respiratory epithelial cells and resident immune structures in the functional respiratory epithelium. There are three secretoglobins that are highly expressed in the human respiratory tract, including SCGB1A1 (aka CC10, uteroglobin, CCSP, CC16, etc.), SCGB3A2 (aka UGRP1, HIN-2) and SCGB3A1 (aka UGRP2, HIN-1).
[0086] The invention generally pertains to the use of respiratory secretoglobins to delay and prevent severe exacerbations of chronic diseases caused by environmental exposures, particularly respiratory diseases. At the tissue level, the respiratory secretoglobins mediate an increase in the numbers of secretoglobin-secreting cells and associated structures in respiratory tissues, which may be measured indirectly through increases in the amounts of their secretoglobin secretion products in body fluids. For example, rhCC10 administration mediates an increase in the number of Clara cells, NEBs, and NECs, restoring the respiratory airway epithelia. At present, this is the only hypothesis that is consistent with the airway epithelial phenotype of CC10 KO mice and explains the data in premature infants pertaining to very strong long-term protection from severe respiratory exacerbations, but not prevention of neonatal BPD, which is a type of pulmonary fibrosis.
[0087] Although rhCC10 did not avert the development of neonatal BPD, it did confer long-term protection from severe respiratory exacerbations requiring re-hospitalization was observed at 6 months PMA, which is the time at which the infant would have been 6 months old after 40 weeks gestation. Since the trial enrolled infants between 24-28 weeks PMA, this endpoint is up to 10 months after a single dose of rhCC10.
BRIEF DESCRIPTION OF THE DRAWINGS
[0088] FIG. 1 : Human SCGB3A2 amino acid sequences, alignment of human SCGB3A2 amino acid sequences with comparison of predicted and actual N-termini
[0089] FIG. 2 : SDS-PAGE of purified rhSCGB3A2, SDS-PAGE of purified rhSCGB3A2. Samples containing 5 micrograms each with and without 1 mM DTT were mixed with SDS Sample Buffer, boiled 5 minutes and loaded on a 10-20% tricine gel. The gel was run and stained with Coomassie R250. The gel was de-stained and imaged with a digital camera.
[0090] FIG. 3 : Isoelectric focusing of purified rhSCGB3A2, Isoelectric focusing of purified rhSCGB3A2, compared to rhCC10 and UBL and Den-1. Samples containing 5 micrograms each were loaded on a Novex IEF gel. The gel was run and stained with Coomassie R250. The gel was de-stained and imaged with a digital camera. Arrows represent major and minor isoforms of rhSCGB3A2 with ATA N-terminus.
[0091] FIG. 4 : In vitro inhibition of sPLA 2 -1B with rhSCGB3A2 Panel A: UNIBIPY substrate; no PLA 2 ; no rhSCGB3A2. Panel B: UNIBIPY substrate plus PLA 2 ; no rhSCGB3A2. Panel C: UNIBIPY substrate plus PLA2 plus rhSCGB3A2. Peak #1 is the UNIBIPY phospholipid substrate, peak #2 is the product after cleavage by sPLA 2 .
[0092] FIG. 5 : Western blot of SCGB3A2 in human TAF. Western blot of tracheal aspirate fluids from human infants compared to purified rhSCGB3A2 using anti-rhSCGB3A2 rabbit polyclonal antibody. Samples containing 20 microliters of each TAF were loaded on a Novex 10-20% tricine gel; rhSCGB3A2 is in lane 1 (5 nanograms) and lane 8 (1 nanogram). The gel was de-stained and imaged with a digital camera.
[0093] FIG. 6 : A standard curve of an ELISA for rhSCGB3A2 is depicted.
DETAILED DESCRIPTION
[0094] Three pieces of evidence were combined to conceive the invention; including 1) the long term protection from severe respiratory exacerbations and re-hospitalization by a single dose of rhCC10 observed in premature infants, 2) the airway epithelial phenotypes of CC10 KO mice, and 3) the “growth factor” properties of SCGB3A2 (Guha, 2012; Kurotani, 2008; Kurotani, 2008a; Inoue, 2008; Niimi, 2001). Despite many years of research, there is no public consensus concerning the role of CC10 in the respiratory epithelium, other than that it mediates anti-inflammatory effects. A recent clinical trial failure in a nasal allergen challenge model of allergic rhinitis demonstrated that the even its anti-inflammatory effects in vivo are not consistent against all types of inflammatory disease (Widegren, 2009). And, despite a complete CC10 deficiency, Clara cells are still found in the airways of both strains of CC10 KO mice. Although CC10 and SCGB3A2 are structurally similar, and, therefore, believed to share some functions, there are no reports pertaining to the stimulation of growth or development of airway epithelial cells by CC10, and rhCC10 is, in fact, well-known to suppress the growth of tumor cells of epithelial origin (Kundu, 1996; Leyton, 1994), including an airway epithelial cell line, A549 (Szabo, 1998).
[0095] We nevertheless believe that the rhCC10 administered to premature infants on the day of birth stimulated the development of CC10-secreting cells, which, in turn, produced native CC10, which stimulated development of more CC10-secreting cells, and so on. The end result was a more normal and resilient respiratory epithelium in the rhCC10-treated infants who were more resistant to all environmental challenges (dust, smoke, allergens, RSV infection, influenza infection, etc.) compared to the placebo-treated infants. A single dose of rhCC10 on the day of birth conferred 100% protection from re-hospitalization due to severe respiratory exacerbation, contrasting the 50% re-hospitalization rate observed in the placebo-treated infants.
[0096] We further believe that the use of CC10 to stimulate development of CC10-secreting cells in the respiratory epithelium will also work in adults with chronic respiratory diseases in which airway remodeling has resulted in loss of Clara cells. A course of treatment with rhCC10 may not cure the disease, but, we believe, would restore, to some extent, Clara cells and associated structures, resulting in a more normal epithelium that is then more resistant to subsequent environmental challenges. The clinical outcome of a course of rhCC10 treatment would then be an increase in the time interval to the next severe exacerbation.
[0097] We further believe that the airway epithelial phenotype of Clara cell deficiency in CC10 KO mice suggests that CC10 is an autocrine and paracrine factor required for the development of Clara cells, associated structures, and other normal cell populations of the airway epithelium. We believe that CC10 is an autocrine and paracrine factor required for the development and maintenance of CC10-secreting cells outside of the respiratory tract, including the gastrointestinal tract and urogenital tract. There is much speculation that because secretoglobins share structural similarities that they will also share similar function, however, no biological activity has ever been previously shown to be shared between any two secretoglobins either in vitro or in vivo. Herein, we report that rhSCGB3A2 shares with CC10, the ability to inhibit porcine pancreatic phospholipase A 2 in vitro. This is the first report that any other secretoglobin, besides CC10, actually inhibits any phospholipase A 2 enzyme or possesses any type of anti-inflammatory activity. Based on these results, we infer that other secretoglobins, including respiratory secretoglobins, which share structural similarities with rhCC10, can stimulate the development and maintenance of the cells that secrete them to effect long-term clinical benefits such as increased time to next exacerbation, decreased severity of next exacerbation, and prevention of severe exacerbations following acute injury.
EXAMPLES
Example 1
Long Term Protection by rhCC10 in Premature Infants with RDS
[0098] The safety, pharmacokinetics, and anti-inflammatory properties of rhCC10 were evaluated in a randomized, placebo-controlled, double-blinded, multicenter trial of 22 premature infants with respiratory distress syndrome (RDS) with mean birth weight of 932 g and mean gestational age of 26.9 wks, who received one intratracheal (IT) dose of placebo (n=7), 1.5 mg/kg (n=8) or 5.0 mg/kg (n=7) of rhCC10 following surfactant treatment (Levine, 2005). rhCC10-treated infants showed significant reductions in TAF total cell counts (P<0.001), neutrophil counts (P<0.001), and total protein concentrations (P<0.01) and decreased IL-6 (P<0.07) over the first 3 days of life. The rhCC10 was safe and well tolerated.
[0099] Remarkably, and despite small numbers, follow-up of 17 infants at 6 months corrected gestational age (CGA) found that 0/11 who received rhCC10 were re-admitted to the hospital for respiratory causes compared to 3/6 receiving placebo as shown in Table 2 (P<0.05 Fisher's Exact Test, two tailed).
[0000]
TABLE 1
Re-hospitalizations for severe respiratory exacerbations
6 months CGA
Placebo (7 enrolled)
3/6
1.5 mg/kg (8 enrolled)
0/6
5 mg/kg (7 enrolled)
0/5
[0100] This result is even more remarkable when considering that 6 months CGA, in this context, means a time period corresponding to 6 months after the infant would have been 40 weeks gestation, and that some infants in the study were 24 weeks post-menstrual age (PMA) at birth, so that the 6 month CGA follow up timepoint occurred as many as 10 months after a single dose of rhCC10 administered on the day of birth. From a statistical standpoint, the results demonstrate at least a 57% incidence of re-hospitalization in the placebo group versus at least a 27% in the rhCC10 group. This is a very powerful long-term effect and these data illustrate a significant and unprecedented long-term benefit for administration of rhCC10.
[0101] It is even more remarkable to find such a profound long term benefit when pharmacokinetic analyses showed that the excess CC10 was eliminated within 48 hours of administration, with a serum half-life of 9-11 hours (Levine, 2005). A significant amount of rhCC10 was observed in the tracheal aspirate fluids for nearly 2 days, and reached the serum by 6h, but was then filtered by the kidney and excreted in urine by 12 h. The rhCC10 followed the natural physiological distribution path from lung to blood to urine and demonstrated long-term benefits, despite the rapid elimination.
Example 2
Cloning and Expression of rhSCGB3A2
[0102] FIG. 2 shows the amino acid sequence of rhSCGB3A2 that was made for these studies. The sequence was taken from Genebank locus AAQ89338. As a result of the recombinant product method that utilized an ubiquitin-like (UBL) fusion system and released the rhSCGB3A2 product from the UBL using a UBL-protease, the N-terminus differs from the N-termini predicted for the native protein using consensus single peptide cleavage sites for mammalian secreted proteins. It also differs from the N-termini of actual peptides isolated from human fluid samples. This is the first description of the synthesis of human SCGB3A2 without a histidine purification tag and the effects of the N-terminus on the stability and activity of the protein could not be predicted. The amino acid sequence of rhSCGB3A2 was shown in Table 1 and has predicted molecular weight of 8147.82 Daltons and a predicted isoelectric point of 6.1.
[0103] A synthetic DNA coding sequence for rhSCGB3A2 was designed using jcat (www.jcat.de), with codon usage optimized for expression in E. coli bacteria K12 strain. Once the DNA sequence was generated, restriction sites were added to the ends to facilitate directional cloning of the gene into the bacterial expression vector, pTXB1, already containing the UBL. SCGB3A2 was cloned as a C-terminal extension of the UBL. An AflII site was placed at the 5′ end and a BamHI site was placed at the 3′ end for directional cloning.
[0104] The new gene for rhSCGB3A2 was synthesized from overlapping oligonucleotides using PCR. The DNA sequence for the rhSCGB3A2 gene is SEQ ID NO 1:
[0000]
CTTAAGAGGTGGTGCTACCGCTTTCCTGATCAACAAAGTTCCGCTGCCG
GTTGACAAACTGGCTCCGCTGCCGCTGGACAACATCCTGCCGTTCATGG
ACCCGCTGAAACTGCTGCTGAAAACCCTGGGTATCTCTGTTGAACACCT
GGTTGAAGGTCTGCGTAAATGCGTTAACGAACTGGGTCCGGAAGCTTCT
GAAGCTGTTAAAAAACTGCTGGAAGCTCTGTCTCACCTGGTTTAGTAAG
GATCC
[0105] The pTXB1 plasmid containing the UBL-rhSCGB3A2 fusion was transformed into E. coli strain HMS174/DE3 which contains a DE3 prophage encoding the T7 RNA polymerase that enables inducible expression of the fusion protein. Colonies were screened for expression of the fusion protein and the rhSCGB3A2 gene was reconfirmed by DNA sequencing in high expressers. A four liter fermentation culture containing SuperBroth media with ampicillin was inoculated from a 120 ml overnight culture of the highest-expressing clone and grown at 37° C. The culture was induced to overexpress the UBL-rhSCGB3A2 fusion protein at an OD 600 of 8.75 using 0.3 mM IPTG, then allowed to grow for another 2 hours. Cell paste was harvested by centrifugation and the wet cell paste yield was 67 grams. The cell paste was then used for purification of rhSCGb3A2.
Example 3
Purification of rhSCGB3A2
[0106] The cell paste was resuspended in 20 mM NaH 2 PO 4 , 0.5 M NaCl, pH 7.2, then the cells were ruptured by freeze-thaw to generate a crude lysate. The crude lysate was clarified by centrifugation at 19,800×g for 20′ at 4° C. DNA, endotoxin, and other bacterial contaminants were precipitated out of the clarified lysate supernatant using polyethylimine (PEI) at a concentration of 0.025% and a second centrifugation at 19,800×g for 10′ at 4° C. The PEI supernatant was then filtered through a 0.22 micron filter and 10 mM imidazole was added to the filtrate. Both the UBL and the UBL protease contain a histidine tag so that they bind to an immobilized metal affinity chromatography column. The filtrate containing the UBL-rhSCGB3A2 fusion protein was then passed over an IMAC column (nickel chelating sepharose fast flow) previously equilibrated in 20 mM NaH 2 PO 4 , 0.5 M NaCl, 10 mM imidazole, pH 7.2, the column was washed with the same buffer, then the UBL-rhSCGB3A2 fusion protein was eluted with 20 mM NaH 2 PO 4 , 100 mM NaCl, 300 mM imidazole, pH 7.2. The IMAC eluate was then concentrated and buffer exchanged using tangential flow filtration with a 5 kDa NMWCO filter in 15 mM Tris, 15 mM BisTris, 40 mM NaCl, pH 7.0. The UBL-rhSCGB3A2 was further purified over a Macro Prep High Q column (BioRad) in which contaminants were bound and the UBL-rhSCGB3A2 flowed through. The rhSCGB3A2 was then separated from the UBL by digestion with UBL protease Den-1 (1:100 molar ratio) in 5 mM DTT, with pH adjusted to 6.5 with HCl, at 37° C. for 2 hours. The rhSCGB3A2 was then purified from the digestion mixture using cation exchange chromatography (GE Sepharose SP High Performance). The SP column was equilibrated with 15 mM Tris, 15 mM BisTris, 40 mM NaCl, pH 6.5, the digestion mixture loaded, and contaminants bound to the column while rhSCGB3A2 flowed through. The SP flow through was then extensively dialyzed against 0.9% NaCl using a 3.5 kDa MWCO regenerated cellulose membrane. The sample was concentrated using centrifugal concentrators (3.5 kDa MWCO), then filtered through a 0.22 micron filter. The filtrate was purified rhSCGB3A2. FIG. 2 shows SDS-PAGE analysis of the final purified protein. It is >97% pure by densitometry of SDS-PAGE, and roughly 95% dimer and 5% monomer. As with rhCC10, it is difficult to completely reduce the dimer to monomer with reducing agents.
Example 4
Isoelectric Point of rhSCGB3A2
[0107] The isoelectric point (pI) of a protein is a measure of the total surface charge of that protein. pI is measured using standard isoelectric focusing (IEF) methods. Approximately 5 micrograms of rhSCGB3A2, rhCC10, UBL, and Den-1 were loaded onto an IEF gel (Novex) in order to determine the pI of rhSCGB3A2 as shown in FIG. 3 . When a protein migrates as a single band on SDS-PAGE and multiple bands are observed in the IEF gel, alternate isoforms of the protein are likely present. In contrast to rhCC10, which shows a single band at pI 4.8, rhSCGB3A2 shows two bands at pI 6.7 and 6.3. The predicted pI of our rhSCGB3A2 sequence is 6.1 (www.expasy.edu; Protein tool “Compute MW/pI”), yet the vast majority of the protein migrates at a position corresponding to a pI of 6.7. Not even the minor band at 6.3 corresponds to the predicted pI of 6.1. That there are two rhSCGB3A2 IEF bands means that either alternatively folded isoforms are present or that they represent monomers and dimers, as visualized in non-reducing SDS-PAGE.
[0108] These pIs further show that this preparation is an unknown and unpredicted isoform of rhSCGB3A2 that is unique. The unique folding pattern of a recombinant protein is often determined by the synthetic process, in this case, the selection of N-terminus, expression of the protein as a C-terminal fusion with an ubiquitin-like protein, IMAC purification of the fusion protein, cleavage of the SCGB3A2 from the UBL, and separation of the SCGB3A2 from the UBL and UBL-protease. Thus, the uniqueness of this preparation may be due to the synthetic process, the non-native N-terminus, or a combination of these or other unknown factors.
Example 5
Inhibition of PLA, by rhSCGB3A2
[0109] The biological activity of rhSCGB3A2 was evaluated in a fluorescent and quantitative HPLC assay that evaluates inhibition of porcine pancreatic secretory PLA 2 enzyme (sPLA 2 ) that was developed to evaluate the potency of different batches of rhCC10. Inhibition of PLA 2 enzymes is thought to be a major anti-inflammatory mechanism of action for CC10. Many have speculated that other secretoglobins may also inhibit PLA 2 enzymes, due to their structural similarities with CC10. The rhSCGB3A2 (5.5 micrograms) was mixed with of 100 nanograms porcine sPLA 2 1B (0.1 microgram) and incubated at 37° C. The reaction was started through the addition of the fluorescent phospholipid analogue 2-decanoyl-1-(O-(11-(4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-propionyl)amino)undecyl)-sn-glycero-3-phosphocholine (aka UNIBIPY; 47.6 nanograms). After 15 minutes the reaction was terminated by the addition of 2-propanol/n-hexane. The cleavage product was separated from the substrate on a Waters Spherisorb silica HPLC column. The separation was followed with a G1321A fluorescence detector.
[0110] Results of the assay are shown in FIG. 4 . Panel A shows the UNIBIPY substrate without sPLA 2 or rhSCGB3A2; panel B shows the UNIBIPY substrate plus sPLA 2 , and panel C shows the UNIBIPY substrate plus sPLA 2 plus rhSCGB3A2. The sPLA 2 cleaves the substrate (peak #1), giving rise to a product (peak #2). In the presence of rhSCGB3A2, the product peak is significantly reduced. Each reaction set was run in duplicate. The rhSCGB3A2 showed 83% inhibition of sPLA 2 -1B activity in the assay, which is comparable to rhCC10 protein (data not shown).
[0111] Percent inhibition is calculated as follows:
[0000] % inhibition={1−(average of the cleaved area with rhSCGB3A2/(average of the cleaved area without rhSCGB3A2)}×100
[0112] It was concluded that the rhSCGB3A2 does inhibit porcine pancreatic sPLA 2 and the level of activity is comparable to rhCC10.
Example 6
Comparison of rhSCGB3A2 to Native SCGB3A2 in Human Fluids
[0113] Purified rhSCGB3A2 was used to immunize two New Zealand white rabbits, using a standard immunization protocol. The protein was conjugated to KLH, mixed with Freund's adjuvant, and injected into the animals. Both animals produced excellent antibody responses with very high titers. IgG was purified from each set of animal sera using a Pierce Protein A IgG Purification Kit and the purified IgGs were dialyzed into PBS, pH 7.2, aliquoted and stored at −80° C.
[0114] The antibodies were qualified by Western blot using tracheal aspirate fluids (TAF) obtained from premature human infants. Samples containing 20 microliters of TAF from 6 infants were run on non-reducing SDS-PAGE and compared to rhSCGB3A2 (5 nanograms). The gel was electro-blotted to PVDF membrane, blocked with 4% non-fat milk, then the highest titer rabbit anti-rhSCGB3A2 IgG (1:5000 dilution) was incubated with the blot, followed by a goat anti-rabbit-HRP conjugate (1:20,000 dilution). The blot was developed using enhanced chemiluminescence (4IPBA-ECL-100 mM Tris/HCl pH 8.8, 1.25 mM luminol, 5.3 mM hydrogen peroxide and 2 mM 4IPBA). Immunoreactive bands appeared in 5/6 of the TAF samples. Two of the samples, (lane 3 and lane 6) contained bands that migrated at the same size as the rhSCGB3A2 homodimer, indicating that the rhSCGB3A2 preparation resembled native human SCGB3A2 in some patients. Heterologous expression of recombinant proteins, especially hydrophobic proteins, for use in animal or human studies often yields misfolded, inactive, immunogenic, or otherwise unusable preparations. Given that the actual N-terminus of native SCGB3A2 is not known and that the pI of rhSCGB3A2 was not as predicted, the observation that at least some human samples contained similar proteins validated our synthetic approach and rhSCGB3A2 preparation. All 5 reactive samples contained high molecular weight species, on the order of 200 kDa and all contained multiple discrete bands in the 8-13 kDa size range, some of which may correspond to monomers, dimers, and alternative isoforms. Two samples (lanes 3 and 7) also contained immunoreactive smears below 3.5 kDa, which likely represent SCGB3A2 degradation products. This is the first time that native SCGB3A2 has been visualized by Western blot. The anti-rhSCGB3A2 antibody used in the Western blot was then used to develop an ELISA for human SCGB3A2.
Example 7
Development of ELISA for rhSCGB3A2
[0115] A competitive ELISA was developed using standard methods. In the competitive assay format, the antibody that captures the target is coated onto the wells of the microtiter plate, then an enzyme-conjugated target molecule (labeled target) is used to compete with unconjugated target in the sample for binding to available sites in the well. As the concentration of target in the sample increases, the amount of labeled target that binds to the wells decreases. The rabbit anti-rhSCGB3A2 antibody was coated onto 96 well Maxisorb plates (200 ng/well) then the wells were blocked with 5% sucrose, 2.5% BSA in PBS, then plates are dried and stored at 4° C. A conjugate of horse radish peroxidase (HRP) and rhSCGB3A2 was made (Pierce kit-EZ-Link Maleimide Activated HRP kit, Cat# 31494) and was used in the assay diluted 1:130,000. Calibrators (1-500 ng) were made using rhSCGB3A2 and the standard curve was generated as shown in FIG. 6 . Native SCGB3A2 was then quantitated in human TAF samples as shown in Table 3.
[0000]
TABLE 3
Native SCGB3A2 in human TAF
[SCGB3A2]
Lane
Sample
(ng/ml)*
1
Rh-SCGB3A2 (5 ng)
2
Infant TAF; Pt. 6
774
3
Infant TAF; Pt. 7
804
4
Infant TAF; Pt. 12
ND
5
Infant TAF; Pt. 15
540
6
Infant TAF; Pt. 17
462
7
Infant TAF; Pt. 19
395
8
Rh-SCGB3A2 (1 ng)
[0116] SCGB3A2 was also measured in 3 adult human serum samples; returning values of 0, 29, and 32 ng/ml. SCGB3A2 could not be detected in unconcentrated human urine, or urine concentrated 10×. The limit of detection of the assay was 5 ng/ml.
Example 8
[0000]
a) A method of use of rhCC10 to prevent hospitalization due to a severe respiratory exacerbation in a patient with acute lung injury for a period of up to ten months after administration.
b) A method of use of rhCC10 to prevent a severe respiratory exacerbation in a patient who experiences frequent exacerbations for at least one month after administration.
c) A method of use of rhCC10 to prevent hospitalization due to severe respiratory exacerbations in a patient with a chronic respiratory condition for a period of at least one month after administration.
d) The method of example a-c where in the chronic respiratory condition is COPD.
e) The method of example a-c where in the chronic respiratory condition is asthma.
f) The method of use of rhSCGB3A2 to prevent hospitalization due to a severe respiratory exacerbation in a patient with acute lung injury for a period of up to ten months after administration.
g) The method of use of rhSCGB3A2 to prevent a severe respiratory exacerbation in a patient who experiences frequent exacerbations for at least two months after administration.
h) The method of use of rhSCGB3A2 to prevent hospitalization due to severe respiratory exacerbations in a patient with a chronic respiratory condition for a period of at least one month after administration.
i) The method of use of rhSCGB3A2 to prevent hospitalization due to severe respiratory exacerbations in a patient with a chronic respiratory condition for a period of at least 2 months after administration.
j) The method of examples g-i where in the chronic respiratory condition is pulmonary fibrosis.
k) The method of examples g-i where in the chronic respiratory condition is bronchiectasis. SCGB3A2:
l) A composition of matter for recombinant human SCGB3A2 protein with N-terminus ATA, comprising seq ID 1.
m) A process for synthesizing recombinant human SCGB3A2 using a UBL fusion protein and UBL protease that recognizes the fusion partner and cleaves between the fusion partner and SCGB3A2, to release the intact SCGB3A2 protein according to seq ID 1.
n) A pharmaceutical composition of rhSCGB3A2 that inhibits PLA 2 enzymes.
o) A pharmaceutical composition of rhSCGB3A2 that migrates in an isoelectric focusing gel corresponding to isoelectric point at or between 6.3-6.7.
p) A pharmaceutical composition of rhSCGB3A2 comprising a homodimer.
q) A pharmaceutical composition of rhSCGB3A2 comprising a homodimer with pI of 6.7 that inhibits PLA 2 enzymes.
[0134] While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
ABBREVIATIONS AND DEFINITIONS
[0135] CC10: Clara cell 10 kDa protein,
[0136] CCSP: Clara cell secretory protein
[0137] CC16: Clara cell 16 kDa protein
[0138] SCGB1A1: protein encoded by the SCGB1A1 gene, same as CC10, CCSP, CC16, uteroglobin
[0139] SCGB3A1: protein encoded by the SCGB3A1 gene, same as HIN-1 and UGRP2
[0140] SCGB3A2: protein encoded by the SCGB3A2 gene, same as HIN-2 and UGRP1
[0141] HIN-1: high-in-normal protein 1
[0142] HIN-2: high-in normal protein 2
[0143] UGRP1: uteroglobin gene related protein 1
[0144] UGRP2: uteroglobin gene related protein 2
[0145] Secretoglobin: Protein from the family of structurally related proteins characterized by four helical bundle monomers connected by disulfide bonds.
[0146] Respiratory secretoglobins: Secretoglobins that are highly expressed and abundant in the respiratory tract, including SCGB1A1, SCGB3A1, and SCGB3A2. | Methods of synthetically producing, formulating and using secretoglobins SCGB1A1, SCGB3A2, and SCGB3A1 are provided. Methods of using secretoglobins SCGB1A1, SCGB3A2, and SCGB3A1 as therapeutic agents to affect long term patient outcomes, such as preventing severe respiratory exacerbations of underlying conditions that require medical intervention, including hospitalization are provided. Methods of producing recombinant human secretoglobins, analytical methods, pharmaceutical compositions, and methods of use to prevent the long term sequelae of acute and chronic respiratory conditions are provided. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of and claims priority from non-provisional application Ser. No. 09/952,792 filed Sep. 14, 2001, the contents of which are herein incorporated by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] The present invention relates to the decarboning of the combustion chamber of an internal combustion engine using a liquid cleaner. More specifically, the present invention relates to the cleaning of the compression rings on the piston associated with the combustion chamber.
[0004] The typical internal combustion engine has at least one combustion chamber associated with a piston. On the piston are a pair of compression rings. The compression rings serve to prevent the escape of gases from the chamber around the sides of the piston during the compression stroke of the engine.
[0005] The only known method of effectively cleaning compression rings is to overhaul the engine. Overhauling involves dismantling the engine, cleaning any carbon coated parts, putting in new rings, and then reassembling. It is extremely costly and time consuming. Further, some modern engines (i.e., the Cadillac Northstar®) cannot be overhauled because of the way they are constructed. Because they cannot be overhauled, carbon buildup on the compression rings in these kinds of engines is a major concern. If the buildup on the rings becomes so great that compression within the combustion chamber unacceptable, the engine must be replaced. This has resulted in these modern engines earning the nickname “throw-away engines.”
[0006] Even though overhauling is the only effective prior art method for cleaning the compression rings, liquid cleaners have been used to clean combustion chambers in the past. One such method involves manually pouring an alcohol based cleaner into the combustion chamber after removing the spark plug and leaving the spark plug hole open.
[0007] This method has two disadvantages. First, alcohol based products tend to cause the carbon deposits to break off rather than dissolve. When carbon deposits break off between the piston rings, they become trapped. These trapped particles can cause engine problems.
[0008] Second, the open spark plug hole does not allow the user to activate the pistons during the cleaning to work the cleaner into and between the compression rings in an effective manner. If the user were to activate the pistons under this prior art method, the cleaner would splash out of the open spark plug hole. Splashed engine cleaners can eat away at external parts of the engine causing irreparable damage. Splash can be prevented by capping the spark plug hole after the cleaner has been poured in. However, capping the hole also precludes the mechanic from activating the pistons while cleaner is in the chamber. The cleaner can become trapped when the piston is in the upper range of its motion in the chamber because it cannot escape out the spark plug hole. The trapped fluid is not compressible (as is air), so the back pressure resists the movement of the piston so that the engine will not turn over. This is called “hydrolocking.” Hydrolocking an engine can cause tremendous damage to the engine's pistons and rods.
SUMMARY OF THE INVENTION
[0009] It is therefore an objective of the present invention to provide a clean and simple method of inducing and maintaining cleaner in the combustion chamber during the cleaning process and an apparatus for enabling such.
[0010] It is a further objective of the present invention to provide a way of maintaining cleaning fluid in the combustion chamber at the same time as activating the piston that prevents fluid from being spilled onto other engine components or hydrolocking the engine.
[0011] It is yet another objective of the present invention to provide a pressurized blowout procedure whereby fluid is forced through the exhaust system of the vehicle after cleaning by way of the application of pressurized air.
[0012] These objectives are accomplished using a new device. The device resembles and is hereinafter referred to as a “squid.” The squid has a cylindrical body with sub-cavities into which cleaner is poured. Each sub-cavity is associated with a conduit which is used to deliver the cleaner to a particular combustion chamber in an engine. Each conduit is connected to an adapter that screws into the engine block of the vehicle being serviced. The adapters are easily screwed into the spark plug opening in the combustion chamber after removing the spark plug.
[0013] The squid enables the user to clean the compression rings of the piston without overhauling the engine. Clean piston rings are essential for maintaining ideal compression ratios within the combustion chamber. The loss of compression within the combustion chamber is caused by a principle called blow-by. The build up of carbon deposits on the compression rings can cause these rings to not sit flush against the cylinder walls. This creates small gaps between the compression ring and the cylinder wall. These gaps cause the compressed air in the combustion chamber to inappropriately blow past the compression rings downwardly past the piston. This lowers engine compression ratios. Poor compression ratios can greatly reduce performance, increase harmful emissions and even completely disable an engine. Also, engine oil can enter the combustion chamber where it is burned and consumed, creating more deposits and increasing engine oil consumption.
[0014] The present invention is the only known solution to blow-by problems in a combustion chamber without overhauling the engine.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The accompanying drawings form part of the specification and are to read in conjunction therewith. Reference numerals are used to indicate like parts in the various figures:
[0016] [0016]FIG. 1 is a fragmented perspective view of the squid in use on a vehicle with an eight-cylinder engine;
[0017] [0017]FIG. 2 is a cross-sectional view at section 2 - 2 in FIG. 1 from above;
[0018] [0018]FIG. 3 is an exploded cross-sectional view at section 3 - 3 in FIG. 2 and also depicting the adaptor of the present invention; and
[0019] [0019]FIG. 4 shows a combustion chamber arrangement within a typical internal combustion engine with an adapter attached.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] The present invention solves the prior art problems noted above by creating a cleaning fluid distributing and maintaining squid 10 shown in FIGS. 1 - 3 . The more general aspects of the invention can be observed in FIG. 1. The squid ring decarbonater 10 has four primary components: (i) a screw cap 12 , (ii) a cylindrical body 14 , (iii) a plurality of conduits 16 , and (iv) a plurality of spark plug adaptors 18 . Adaptors 18 are used to deliver cleaning fluid to an internal combustion engine 20 (see FIG. 4).
[0021] A suspension hook 22 is used to hang squid 10 from the open hood of the vehicle being serviced (not pictured) and is connected to body 14 by a bracket 23 .
[0022] Body 14 is sealed at its upper end when screw cap 12 is screwed on. Screw cap 12 is used to seal off the top of body 14 . The specific details of cap 12 can best be seen in FIG. 3. FIG. 3 shows that pressurized air can be delivered through cap 12 into the cylindrical body 14 by way of a cylindrical bore 24 . A snap-on connector 26 is used to connect to a pressurized air hose 28 . When connected, pressurized air travels from the pressurized air hose 28 through the snap on connector 26 through an elbow 30 down through the bore 24 and into body 14 . Cap 12 is secured by engaging a set of male threads 32 on cap 12 with a set of female threads 34 on body 14 .
[0023] As can be seen in FIGS. 2 and 3, body 14 is bored out to create a main cylinder cavity 36 . Bored out below main cylinder cavity 36 are a plurality of sub-cavities 38 which receive and hold cleaning fluid. Also part of body 14 are a plurality of threaded openings 40 which are used to receive mating threads 44 on each of a plurality of conduits 16 .
[0024] These conduits 16 are valved. The valves 42 on each conduit 16 have upper threads 44 and lower threads 46 . Each valve 42 is opened or shut using a valve control lever 48 . The valves themselves 42 may be common ball valves or any other type of valve known in the art capable of optionally opening up or shutting off flow. The upper threads 44 are used to mesh with the threaded openings 40 on the bottom of the cylindrical body 14 to secure the conduit 16 thereto and permit flow into the conduit from the main body. The lower threads 46 on the valve are received by threads on a first threaded connector that is connected to a translucent tubing 52 . Translucent tubing 52 should be constructed of nylon material capable of withstanding the chemicals transmitted through it. At the other end of the translucent tubing 52 is a second threaded connector 54 . The second threaded connector 54 is used to attach the spark plug adaptor 18 .
[0025] The spark plug adaptor 18 has a set of upper end threads 56 which are used to mate with the second threaded connector 54 of the conduit 16 . The adaptor 18 also has a set of header engaging threads 56 which are of the same pitch and size as the threads on an ordinary spark plug. The adaptor 18 is essentially a hollow tube which defines a metered compression rate controlling passageway 60 . Passageway 60 is used to control the compression rate through the adaptor 18 and conduit 16 during back flow of fluid through the system. This is done by boring passageway to a diameter that allows a limited amount of forced flow there through.
[0026] As can be seen in FIG. 4, the spark plug receiving threads 62 on the spark plug holes 70 on the vehicle's header 20 are used to receive header engaging threads 58 on the adaptor 18 . This connects the adaptor 18 to the header 62 allowing the passage of fluid into the engine's combustion chamber 64 . The combustion chamber 64 is sealed at its lower end by a piston head 66 . At the top of the combustion chamber 64 are intake 67 and exhaust 68 valves and spark plug opening 70 . The typical piston head 66 has a pair of compression rings 72 at its upper end which are used to compressibly seal off the combustion chamber 64 from below. A single oil ring 74 is used to seal off the combustion chamber from the seepage up of oil from below during suction stroke of engine 20 .
[0027] The squid decorboning process has four steps. First, squid 10 must be filled with cleaner. Second, squid 10 is used to transmit the cleaner from the squid to fill the combustion chambers on the vehicle being serviced. Third, the engine is “bumped” in order to work the cleaner into the compression rings. Finally, the cleaner is blown out of the combustion chamber under pressure administered by the squid. Before beginning the decarboning process, engine 20 should be brought up to operating temperature (usually 195 to 200 degrees) so that the carbon deposits become softer. This makes them easier to be cleaned. It's also very important to disable the ignition coils to prevent electrical damage to the ignition system.
[0028] With respect to the first step of filling the squid, Cap 12 should be removed from the body 14 to expose main cavity 36 and eight sub-cavities 38 . The user should make sure that all of the valves 42 are closed. Next, each of the spark plugs on the engine 20 should be removed and replaced with adapters 18 . (See FIG. 4). Adapters 18 are attached by screwing header engaging threads 58 into each threaded spark plug opening 70 for combustion chamber 64 on engine 20 . As can be seen in FIG. 3, conduits 16 should then be secured to the conduit end threads 56 on each of the adaptors 18 that have been secured to the engine 20 . It is apparent that with engines with fewer than eight cylinders, some conduits 16 will be left over after all of the adaptors 18 have been hooked up to a conduit 16 . These left over conduits 16 will remain idle during the cleaning process. As can best be seen from FIG. 3, each conduit 16 is associated with a particular sub-cavity 38 . Next, sub-cavities 38 should be filled with cleaner.
[0029] The preferred cleaner of the present invention is a solvent offered by BG Products, Inc. located in Wichita, Kans. and sold under the name BG 211 Induction System Cleaning, BG Part 211. The composition of the solvent is readily ascertainable from the label of the product. This solvent is preferred over the alcohol based solvents used in the prior art methods described above because it dissolves the carbon particles rather than breaking them off. As described in the background section above, carbon particles can be problematic when they are trapped between the compression rings of a piston. While this BG 211 solvent is the preferred solvent of the system, it is to be understood that other solvents capable of dissolving carbon deposits may also be used and are within the scope of the present invention.
[0030] Only the sub-cavities 38 that are associated with attached conduits 16 should be filled. The sub-cavities 38 that are associated with idle conduits 16 should not.
[0031] After filling the appropriate sub-cavities 38 , cap 12 should be screwed on to body 14 . The hood of the vehicle to be serviced (not pictured) should be opened up and suspension hook 22 used to hang the squid 10 from the hood. The underside of a typical car hood has an opening near the hood latch that can be used to receive the hook 22 . Once hung, squid 10 is ready to fill the combustion chambers with cleaner.
[0032] To fill the combustion chambers with cleaner, the valve control levers 48 on each of the hooked up conduits 16 should be turned to open position. This means that for an eight cylinder engines all eight will be opened up. However, for a smaller engine, such as a four-cylinder, only four of the valves would be opened up and the remaining four would remain closed. Once the appropriate valves 42 have been opened up, the cleaning solution will run down the conduits 16 through the metered compression rate controlling passageway 60 into the combustion chamber 64 of the engine 20 . The valves 42 should remain open during the steps that follow.
[0033] The third step involves bumping the engine. Bumping means that the user will briefly turn the ignition starter so that the pistons move up and down only a couple of inches. Since the cleaner is now in the combustion chambers 64 , the cleaner will be massaged into the rings. This bumping process is impossible with any of the prior art methods. As explained in the background section, the prior art methods involved either capping or uncapping opening 70 . Capping opening 70 while bumping the engine 20 results in hydrolocking the engine when the piston is in its up-stroke. Leaving opening 70 uncapped while bumping causes cleaner to spew out chamber 64 onto outside engine components causing them to decompose if they are susceptible to the harsh chemicals in most cleaners.
[0034] These prior art dilemmas have been overcome by the squid 10 . When the piston is in its up-stroke, squid 10 allows the cleaner to be vented up into the metered portion 60 of the adaptor 18 (see FIG. 3) and through the conduit 16 back up into the body 14 . The metered section 60 of the adaptor 18 serves to control the pressurization rate of the fluid such that it can be safely delivered through the conduit 16 up into its respective sub-cavity 38 . The squid acts as a vent releasing the cleaner from the combustion chamber, while at the same time safely containing it. This prevents any damage to the piston or rods that could be caused by hydrolocking the engine.
[0035] On the down-stroke of piston 66 , however, the fluid will be drawn back down out of the sub-cavity 38 through the conduit 16 into adaptor 18 and back into chamber 64 . The cleaner moves in and out of the chamber 64 consonant with piston 66 position during bumping.
[0036] The bumping process works cleaner into the compression rings 72 thoroughly. This causes the carbon deposits on rings 72 to dissolve into the cleaner. The engine 20 should be bumped several times for optimal results. The user should ideally wait 15 minutes between each bumping in order to allow the cleaner to gradually dissolve the carbon deposits on the compression rings 72 . After the bumping process has been repeated every 15 minutes for the desired amount of time (usually 2 hours), it is time to blow out the cleaner.
[0037] The blowing out process is accomplished by attaching a pressurized air source 28 onto snap on connector 26 . Engine 20 should then be turned over continuously for 30 to 60 seconds while user observes the translucent tubes 52 for the presence of cleaner. The pressurized air from the hose 28 forces the cleaner from the sub-cavities 38 down through conduits 16 through adaptors 18 into combustion chambers 64 and then out the exhaust valves 68 of the engine 20 and then out the vehicle's exhaust system. Once tubes 52 are clear of cleaner, the user should continue turning the engine under pressure over for another 15 seconds. The pressure should be turned off. This completes the blow out process.
[0038] The valves 42 that were opened should now be closed, and adaptors 18 unscrewed and removed from spark plug holes 70 . New spark plugs should then be screwed into spark plug holes 70 . The disconnected ignition coils should also be reconnected. It is also important to note that the engine oil system should be chemically flushed within one hour of the completion of the squid service. This is done to remove any chemical and/or carbon deposits that may have reached the oil pan below the cleaned piston. The vehicle should never be allowed to sit overnight before performing such an oil flush because any cleaner within the fluid can damage components of the engine.
[0039] The removal of carbon deposits from the compression rings restores compression to the cylinders lost due to the buildup of carbon deposits. The effectiveness of compression restoration can be determined by performing a compression check on each cylinder after the cleaning. Besides the compression rings, the squid service also removes carbon deposits from the combustion chamber and valves. Oil ring 74 has been cleanable under prior art methods of power flushing oil systems. However, the squid of the present invention enables the cleaning of compression rings 72 without completely overhauling the engine—an impossibility prior to the present invention. The fact that oil ring 74 could be cleaned by prior art methods was of little significance before this invention because such cleaning would not improve engine performance because of the unremovable buildup of carbon deposits on the compression rings. Now that compression rings 72 can be cleaned along with the oil ring 74 , combined cleaning restores overall compression in the combustion chamber 64 with unprecedented effectiveness. This makes squid 10 an important tool in overcoming compression problems caused by carbon deposits on compression rings. This is especially true for modem engines such as the Ford Northstar® that cannot be overhauled. The squid essentially saves the mechanic from having to throw out the engine when carbon deposits cause compression ratios to become unacceptably poor. Now the mechanic can restore compression by merely servicing the engine with cleaner.
[0040] Though the present invention has been described herein with reference to particular embodiments, a latitude of modification, various changes, and substitutions are intended in this disclosure, and it will be appreciated by one skilled in the art that in some instances some features of the invention will be employed without a corresponding use of other features without department from the scope of the invention as set forth in the following claims. | A device for and method of decarboning a combustion chamber and compression rings in an internal combustion engine. The device is a squid shaped container with a cylindrical body, a screw cap, and conduits depending from the body for transmitting cleaner to the combustion chambers on the engine. Once cleaner is transmitted to the combustion chambers, the engine is bumped to work the fluid into the compression rings. When the engine is bumped, the device allows the cleaner to be vented to the device to avoid hydrolocking the engine. The device also contains the cleaner so that it is not splashed outside the engine. | 5 |
TECHNICAL FIELD OF THE INVENTION
This invention relates in general to arrangements for emergency escape from a building and, more particularly, to such an arrangement which includes a window apparatus having a collapsible escape ladder.
BACKGROUND OF THE INVENTION
Multi-story structures are common today. When an emergency occurs in a multi-story structure, the people on the second, third or higher floors may find it difficult to reach the normal exits. When normal exits are unavailable, alternate emergency exits must be found. One such alternate emergency exit is a window. However, exiting through a window two or more stories above the ground may be dangerous.
A ladder may be used to exit from second story or higher windows, but storing a noncollapsible ladder by every window is impractical. Thus, foldable escape ladders were developed to avoid the storage problem. One example is the combination window and escape ladder disclosed in U.S. Pat. No. 5,467,841. While these known systems have been generally adequate for their intended purpose, they have not been entirely satisfactory in all respects. For example, the structural features of the window specific to the emergency escape feature are often complex and expensive, and may interfere with the extent to which the window can be used in a normal manner when there is no emergency. Accordingly, it is an object of this invention to provide a foldable escape ladder that can be located easily and quickly in an emergency, that does not interfere with normal use of an associated window, and that is relatively simple and inexpensive.
SUMMARY OF THE INVENTION
From the foregoing, it may be appreciated that a need has arisen for an apparatus for facilitating emergency exit from multi-story structures, which is integrated into a window in a manner which minimizes interference with normal use of the window, which is easy to locate and deploy, and which is relatively simple and inexpensive.
According to the present invention, an apparatus is provided to address this need, which includes a window frame, the window frame including a lower portion which has thereon an upwardly facing surface and which has therein a recess that opens upwardly through a vertical opening provided in the upwardly facing surface, the window frame further including a sill part movable relative to the lower portion between a first position obstructing the opening and a second position remote from the opening. The apparatus further includes a window part supported in the frame for movement relative thereto between open and closed positions, the window part being movable independently of the sill part, and the window part being in sealing engagement with the sill part when the window part is in the closed position and the sill part is in the first position. Also included in the apparatus is an escape ladder which includes flexible first and second elongate elements each having first and second ends, and which includes a plurality of rung elements extending between the elongate elements at spaced locations therealong, wherein the ladder can be removably received within the recess. The apparatus also includes an arrangement for retentively coupling the first end of each elongate element to the window frame.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the present invention will be realized from the detailed description which follows, taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a diagrammatic perspective view of a two-story structure which has a window escape ladder system embodying the present invention;
FIG. 2 is a diagrammatic perspective view of the window escape ladder system of FIG. 1;
FIG. 3 is a sectional side view of part of a window frame and a deployed escape ladder which are components of the window escape ladder system of FIG. 2;
FIG. 4 is a sectional side view similar to FIG. 3, but with the escape ladder in a stored condition;
FIG. 5 is a sectional side view similar to FIG. 3, but showing an alternative embodiment of the window frame and escape ladder; and
FIG. 6 is a sectional side view similar to FIG. 3, but showing a further alternative embodiment of the window frame and escape ladder.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a diagrammatic perspective view of a two-story structure 10, which in the disclosed embodiment is a house. The structure 10 includes a door 11, a plurality of first story windows 12 and a plurality of second story windows 13. One of the second story windows 13 is equipped with an escape ladder system 16, which is more fully described in association with FIG. 2. The escape ladder system 16 allows a person to safely descend from the second story window 13 to the ground outside of the house, for example in the event of an emergency such as a fire.
FIG. 2 is a diagrammatic perspective view of the window 13 equipped with the escape ladder system 16. The window 13 includes a window frame 21, within which is movably supported a window part 22. The window part 22 can move in a generally vertical manner within the window frame 21 between an open position and a closed position. FIG. 2 shows the window part 22 in the open position. A sill part 23 is pivotally supported at one end within the window frame 21. The sill part 23 is pivotally coupled to the window frame 21 via a hinge 26. The sill part 23 moves by pivoting on the hinge 26 between an open position and a closed position. FIG. 2 shows the sill part 23 in the open position. The window part 22 and the sill part 23 can move independently of each other. The sill part 23 can only be opened when the window part 22 is in the open position. Similarly, the window part 22 can be closed only when the sill part 23 is in the closed position.
Also provided within the window frame 21 is an opening 31 that opens downwardly into a recess 32 provided in the window frame 21, the opening 31 being of a rectangular shape and being provided through an upwardly facing surface 33 on the window frame 21. Extending out of the recess 32 through the opening 31 is an escape ladder 36. The opening 31, recess 32 and escape ladder 36 are more fully described in association with FIG. 3.
A clearer understanding of the escape ladder system 16 is achieved by considering the perspective view of the escape ladder system 16 of FIG. 2 in association with the sectional view of the recess 32 and escape ladder 36 shown in FIG. 3. As shown in FIG. 2, the escape ladder 36 includes a first elongate element 41 and a second elongate element 42. The elongate elements 41 and 42 are flexible and are made of a weight-bearing material such as rope or chain. The elongate elements 41 and 42 support one or more rungs 43. Each rung 43 has a first and second rung end which are respectively fixedly coupled to the first and second elongate elements 41 and 42. Rungs 43 are typically attached to the elongate elements 41 and 42 in such a way that the rungs 43 are regularly spaced therealong with respect to each other. As shown in FIG. 3, each of the elongate elements 41 and 42 has a first end, one of which is indicated by reference number 51. The first ends 51 are coupled to a retaining element 52. The retaining element 52 is a rectangular element of dimensions greater than those of the opening 31. The retaining element 52 can move in a generally vertical manner within the recess 32, but cannot exit through the opening 31 because the retaining element 52 is greater in size than the opening 31. FIG. 3 shows the retaining element 52 at the element's highest vertical travel point. When the retaining element 52 is at the element's highest vertical travel point, the retaining element 52 is engaged with a downwardly facing surface 53. When the retaining element 52 is engaged with the downwardly facing surface 53, the retaining element 52 is prevented from moving further in an upward direction.
FIG. 4 is a sectional side view of the window frame 21 showing the escape ladder 36 stored in the recess 32. When the escape ladder 36 is stored in the recess 32, the elongate elements 41 and 42 and the rungs 43 are preferably arranged in a serpentine manner which facilitates removal of the escape ladder 36 from the recess 32. The retaining element 52 is shown in FIG. 4 in its stored position at the bottom of the recess 32. The elongate elements 41 and 42 each have a second end 57, and FIG. 4 shows the second end 57 of the first elongate element 41. The second end 57 is also shown in its stored position in the recess 32. The second end 57 is coupled to the last or bottom rung 43 which is a part of the escape ladder 36. FIG. 4 further shows the sill part 23 in the closed position. Secured to the upward facing surface of the sill part 23 is a seal element 61, which extends the full length of the sill part 23.
An alternate embodiment of the present invention is shown in FIG. 5, which is a sectional side view of the window frame 21. In this embodiment, the hinged sill part 23 is replaced with a sill part 71. The sill part 71 is not coupled to any part of the window frame 21. The sill part 71 includes a downward projection 73. The projection 73 has dimensions slightly less than those of the opening 31 so that the projection 73 can approximately fill the opening 31. The projection 73 approximately fills the opening in order to substantially prevent horizontal movement of the sill part 71 relative to the window frame 21. The projection 73 of the sill part 71 is coupled to the second ends 57 of the first and second elongate elements 41 and 42. Thus, in this embodiment, the sill part 71 also serves as the bottom rung 43 of the escape ladder 36.
Another alternative embodiment of the present invention is shown in FIG. 6, which is a sectional side view of a modified window frame 121. In this embodiment, a cavity 76 provided in the window frame 121 receives a cartridge 81. The cavity 76 is of dimensions just large enough to admit the cartridge 81. In this embodiment, the escape ladder 36 is loaded into the recess 32 provided inside the cartridge 81. The escape ladder 36 can then be deployed through the opening 31 provided in the top part of the cartridge 81. The cartridge 81 is secured within the cavity 76 by a bolt 87. The bolt 87 can be removed to allow insertion or removal of the cartridge 81 to or from the cavity 76.
FIG. 6 also shows the addition of a spacer 88 to each end of each rung 43. The spacers 88 are of round cross-sectional shape, and project horizontally inwardly from rungs 43. The spacers 88 are preferably integral with the rungs 43. In the operational position of the ladder, the spacers 88 project horizontally toward and engage a wall, to keep the rungs 43 spaced from the wall.
The following is a description of the operation of the embodiment of FIGS. 1-4. In an emergency, a person on the second floor of the two-story structure 10 who is prevented from reaching the door 11 can escape from the structure 10 by going to the second story window 13 equipped with the escape ladder system 16. The person may find that both the window part 22 and the sill part 23 of the second story window 13 are in their closed positions. When both the window part 22 and the sill part 23 are in their closed positions, the bottom edge of the window part 22 is resting on the seal element 61 which is located on an upward facing surface of the sill part 23. Thus, when both the window part 22 and the sill part 23 are in their closed positions, a seal is formed between the two parts 22 and 23 by the seal element 61.
As described previously in association with FIG. 2, the sill part 23 cannot be placed in the open position until the window part 22 is first placed in the open position. As shown in association with FIG. 4, when the sill part 23 is in the closed position, the opening 31 is blocked, which prevents the removal of the escape ladder 36 from the recess 32. Therefore, in order to utilize the escape ladder 36, the person first moves the window part 22 to the open position and then moves the sill part 23 to the open position. As is shown in association with FIG. 2, once both the window part 22 and the sill part 23 are in their open positions, the opening 31 is exposed and the escape ladder 36 can be deployed.
In order to deploy the escape ladder 36, the escaping person will reach, with one or more hands, through the opening 31 into the recess 32 and grasp part of the escape ladder 36. A preferred place to grasp the escape ladder 36 is typically the bottom rung 43, or some part of the first or second elongate elements 41 and 42 near the second ends 57 of the elongate elements 41 and 42. The person will then pull the escape ladder 36 out through the opening 31 and deploy it toward the outside of the second story window 13. As the escape ladder 36 is being deployed, the retaining element 52 moves in a vertical manner toward the top of the recess 32. As the retaining element 52 moves toward the top of the recess 32, the retaining element 52 comes into engagement with the downwardly facing surface 53. Once the retaining element 52 and the downwardly facing surface 53 are engaged, the retaining element 52 has reached its maximum vertical position and is prevented from exiting the recess 32 through the opening 31. Once the retaining element 52 has reached the top of the recess 32 the escape ladder 36 has typically been fully deployed, as is shown in FIG. 3. The person can now exit the structure 10 through the second story window 13 by descending to ground level via the escape ladder system 16.
In the alternate embodiment of FIG. 5, as previously described, the sill part 71 is not pivotally supported. However, the window part 22 must still first be in the open position before the sill part 71 can be moved away from the position of FIG. 5. The seal element 61 still creates a seal between the sill part 71 and window part 22 as previously described. In this embodiment, since the sill part 71 is coupled to the second ends 57 of the first and second elongate elements 41 and 42, the person first deploys the sill part 71 toward the outside of the second story window 13. Deploying the sill part 71 causes the rest of the escape ladder 36 to begin deployment. The person may or may not have to manually assist with the deployment of the escape ladder 36. The sill part 71 may or may not be of sufficient weight to complete the deployment of the escape ladder 36 without further manual assistance. Once the escape ladder 36 is fully deployed, the unattached sill part 71 acts as the bottom rung.
In the alternate embodiment of FIG. 6, the escape ladder 36 is stored in the recess 32 provided within the cartridge 81. The cartridge 81 can be inserted or removed from the cavity 76. Once the cartridge 81 has been inserted into the cavity 76, the cartridge 81 is secured in the cavity 76 using the bolt 87. When the cartridge 81 is secured in the cavity 76 by the bolt 87, the cartridge 81 cannot be removed, thus, in order to remove the cartridge 81 the bolt 87 must be unfastened. The cartridge 81 could be removed and replaced with a replacement cartridge in order to replace a damaged escape ladder. Alternatively, the cartridge 81 could be removed to facilitate repair of the escape ladder 36 after the escape ladder 36 had been damaged.
When an emergency situation arises, the cartridge 81 should already be secured within the cavity 76, and remains secured there throughout the emergency. In response to the emergency, the escape ladder 36 is deployed in substantially the same manner as described for the embodiment of FIGS. 1-4, and a detailed explanation of deployment is therefore not repeated for the embodiment of FIG. 6.
After the escape ladder 36 of FIG. 6 is deployed, the spacers 88 coupled to the rungs 43 ensure that an appropriate amount of space is maintained between the rungs 43 and the vertical building surface. The spacers 88 allow for a more secure footing on the rungs 43 for the person.
The present invention provides a number of technical advantages. One such technical advantage is the ability to store the escape ladder in a location near that of the expected emergency exit point. A further advantage is that the escape ladder can be quickly deployed in the event of an emergency. Yet another advantage is that the escape system is relatively simple and inexpensive, and produces minimal interference with normal use of an associated window.
Although one embodiment has been illustrated and described in detail, it should be understood that various changes, substitutions and alterations can be made therein without departing from the scope of the present invention. For example, although one of the embodiments shows the use of spacers for the rungs, the spacers could be used with any of the described embodiments. Also, the cartridge is secured in place by a bolt, but could be secured by some other release mechanism. As another example, the elongate elements are made of rope, but could be chains or some other flexible material.
It should also be recognized that direct connections disclosed herein could be altered, such that two such disclosed components or elements would be coupled to one another through an intermediate device or devices without being directly connected, while still realizing the present invention. Other changes, substitutions, and alterations are also possible without departing from the spirit and scope of the present invention, as defined by the following claims. | An emergency escape system (16) for a window (13) of a building (10) includes an escape ladder (36) stored within a window frame (21). A sill part (23) covers a recess (32) containing the escape ladder and allows a window part (22) to form a normal seal with the sill as if no escape ladder system were present. In an emergency, the escape ladder can be quickly deployed to allow a person to exit the building safely through the window. Spacers (88) can be used to provide a more stable escape ladder. A removable cartridge (81) can also be used to easily replace the escape ladder system after the escape ladder has been used or damaged. | 4 |
This is a continuation of application Ser. No. 609,747, filed May 14, 1984 now abandoned.
BACKGROUND OF THE INVENTION
It is often necessary to connect or disconnect conductors (or contacts) along one electrical component with corresponding conductors (or contacts) along another electrical component.
Moreover, it is often desired that such connection (or disconnection) be convenient, effective and performable in an area inaccessible by tools.
It is also often desired that connection (or disconnection) be effectuated with a zero insertion (or removal) force. This feature may be required to prevent damage to the components being connected.
In addition, it is typically desired in numerous applications of electrical connectors to provide connection between closely spaced parallel conductors; to provide high strength closure; and high resistance to shock and vibration. Conventional approaches which teach separate coupling elements for each conductor on one component to be connected to a corresponding conductor on a second component have rendered such features difficult to attain.
SUMMARY OF THE INVENTION
In accordance with the invention, an electrical connector is provided which realizes the aforementioned features as objects.
The present invention relates preferably to a multipin electrical connector including (a) male member having a plurality of conductors thereon extending longitudinally in parallel and (b) a female member that includes a split tube to receive the male member. A plurality of parallel conductors on the female member extend along the inside of the split tube which receives the male member. A plurality of parallel conductors on the female member extend along the inside of the split tube are spaced to correspond with the conductors along the male members. The male member has an enlarged edge that is insertable into the split tube so that each conductor along the inside of the split tube faces a corresponding conductor along the enlarged edge of the male member. The split tube comprises Nitinol or some other shape memory material which is biased open (or closed) and which, upon heating to a transition temperature, changes dimensions to disengage (or engage) the inserted male member.
Such a connector features zero insertion force, high strength, close conductor spacing, and high shock resistance. Upon closure, the conductors along the male member contact corresponding conductors along the split tube.
Preferably, the invention pertains to an electrical connector for coupling two strips together. The first strip has a split tube forming one edge thereof, the split of the tube being selectively opened and closed. The second strip is inserted into the split when the tube is open, whereupon the tube may be closed to effect coupling of the two strips.
In accordance with the invention, the second strip may include at least one conductor therealong which is to be coupled to a corresponding conductor along the first strip. Typically, parallel conductors on the upper surface and on the lower surface of the second strip are couplable to corresponding conductors of the first strip by closure of the split tube thereagainst.
In one embodiment, the conductors along the upper surface of the second strip are separate and indpendent from the conductors along the lower surface thereof. Also, conductors along the first strip can similarly be defined with (a) an upper plurality of conductors that can close against conductors along the second strip upper surface and (b) a lower plurality of conductors independent of the upper plurality that can close against conductors along the second strip lower surface. Hence, a double connector is provided wherein a plurality of connections can be effected in an upper plane separately and distinct from connections effected in a lower plane. That is, where x conductors are provided along the upper surface and x conductors are provided along the lower surface of the second strip, 2x connections can be made.
In a second embodiment, conductors along the upper surface of the second strip extend into the conductors along the lower surface. Similarly, the upper plurality of conductors of the first strip may extend into the lower plurality of conductors. This is a single connector embodiment. This arrangement provides an upper area and a lower area of electrical contact for each conductor.
Hybrid embodiments which vary from the above two embodiments--the single connector and double connector--may include maintaining some of the conductors on the upper surface of the second strip independent of the conductors on the lower strip while other conductors on the upper strip extend into conductors on the lower strip.
Also, it is envisioned that all conductors along the upper strip extend into the conductors along the lower strip of the second strip whereas all conductors in the upper plurality of the first strip do not extend into conductors in the lower plurality. Accordingly, two sets of lines connected respectively to the upper plurality of the first strip and to the lower plurality of the first strip may be interconnected upon closure against the second strip, as well as providing connection between the conductors on the first strip and second strip.
In the various embodiments it is contemplated that the split tube include at least a shape memory layer formed, preferably, of a shape memory metal such as a nickel titanium alloy. More specifically, it is preferred that the split tube comprise coaxial layers which include a shape memory layer, a stainless steel layer disposed about the shape memory layer, and a flexible plastic layer--into which conductors are imbedded--enclosing the split tube. Depending on how heat is applied to the shape memory layer, a heater element may be provided adjacent the shape memory layer along the portion of the flexible plastic layer which inscribes the split tube.
To provide a locked coupling, the edge of the second strip inserted into the interior of the split tube is enlarged.
In accordance with the invention, closure of the connector is performed by heating a shape memory layer to a characteristic transition temperature. It is, however, contemplated that opening of the connector may also be performed by heating a shape memory layer to a characteristic transition temperature. It is known that a shape memory metal in its memory shape displays high strength; thus the closure or opening to a memory shape results in a high strength configuration.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is an upper back left perspective view illustrating a connector according to the invention.
FIGS. 2 through 5 are side-view illustrations showing the operation of the connector of FIG. 1.
FIG. 6 is an illustration of one embodiment of an element formable into a first strip shown in FIG. 1.
FIG. 7 is an illustration of one embodiment of an element formable into a second strip shown in FIG. 1.
FIG. 8 is an upper front left perspective view of a double connector formed from the first strip of FIG. 6 and the second strip of FIG. 7.
FIG. 9 is an alternative embodiment of an element formable into a second strip shown in FIG. 1.
FIGS. 10 and 11 are perspective and side view illustration of the invention including a cover.
DESCRIPTION OF THE INVENTION
In FIG. 1, one embodiment of an electrical connector 100 according to the invention is illustrated.
The connector 100 is shown including a first strip 102 which terminates in a split tube 104. The split tube 104 is shown formed of a plurality of coaxial layers. Extending peripherally about the split tube 104 is a flexible plastic layer 106 which serves to inscribe and circumscribe the split tube 104. That is, the flexible plastic layer 106 extends along a flat two-layer portion 107 of the first strip 102, passes circumferentially to an upper lip 108 whereupon the plastic layer 106 traces the inner surface of the split tube 104 to a lower lip 110. From the lower lip 110, the plastic layer 104 follows the lower outer circumference of the split tube 104 back to the flat portion 107 of the first strip 102. The flat portion 107 comprises two plastic layers that lie against each other as a laminate.
The split tube 104 also includes a shape memory layer 112 about which is disposed another layer 114. The layer 114 is preferably stainless steel. The shape memory layer 112 and layer 114 are enclosed by the flexible plastic layer 106.
Provided along the inscribing portion of the flexible plastic layer 106 is a flexible heater 120 of a construction known in the art. The heater 120 is adjacent the shape memory layer 112 to direct heat thereto.
Also provided along the flexible plastic layer 106 are parallel conductors 130, 132, and 134 (the number being variable) along the upper layer 126 of the first strip 102. Along the lower layer 128 of the first strip 102 are parallel conductors 136, 138, and 140. Each conductor 130 through 134 extends along the flat portion 107 to follow an outer circumscribing path toward and around the upper lip 108. Each conductor 136 through 140 follows a similar path along the lower layer 128 of the first strip 102. As discussed below, the conductors 130 through 134 along the upper layer 126 may or may not extend into corresponding conductors 136 through 140 along the lower layer 128 depending on embodiment.
Preferably, the conductors 130 through 140, as well as the heater 120, are embedded in the flexible plastic layer 106 to enhance durability, shock and impact resistance, integrity of structure, and strength and to maintain the relative positions of conductors and heater strips. That is, the conductors 130 through 140 and heater 120 are covered by plastic layer 106. To expose the conductors to permit electrical contact therewith--as by pressing another conductor thereagainst--windows are provided in the plastic layer 106 where contact is to be made. As described below, the windows expose at least those portions of the conductors 130 through 140 along the upper lip 108 and the lower lip 110. The space therebetween, it is noted, defines the split of the tube 104 between which a second strip 150 is insertable.
The second strip 150 includes two flexible plastic layers 152 and 154 lying coextensively against each other. The upper layer 152 has conductors 160 through 164 therealong. The lower layer 154 also has conductors 166 through 170 (not shown) extending therealong. To expose the conductors 160 through 164, a window 174 is provided in the upper layer 152. A similar window is preferably provided in the lower layer 154 also.
The second strip 150 also includes an enlarged edge 176 which is insertable into the interior of the split tube 104. (The edge 176 is enlarged by inserting a rod or the like between the two layers 150 and 152 at the fold therebetween.) By enlarging the edge 176, the two strips 102 and 150 cannot be pulled apart after the split tube 104 is closed with the edge 176 inserted. Specifically, the edge 176 preferably abuts the upper lip 108 and the lower lip 110 upon closure to effectuate the desired locking effect.
The connector 100 in FIG. 1 is shown with the split tube 104 closed. To enable the second strip 150 to be inserted, the split tube 104 is deformed to open the split. In this regard, it is noted that the shape memory layer 112 may serve to either open the tube 104 from a closed position or close the tube 104 from an open position. Whether the shape memory layer 112 acts to open or to close the tube 104 depends on the memory shape imparted to the layer 112. The shape memory layer 112 comprises a material that can be formed to a predefined memory shape or configuration. After the memory shape is defined, the material can be deformed and, by bringing the material to a characteristic transition temperature, returned (or recovered) to the memory shape. Although various plastics feature heat recoverable memory, it is preferred that the shape memory layer 112 be a metal which undergoes transition such as a nickel titanium alloy, or Nitinol.
The operation of Nitinol and other alloys which exhibit such memory or recovery from a heat unstable state is discussed in various references and is not elaborated on here. Reference is made, however, to U.S. Pat. No. 3,606,592 to Madurski et al and to U.S. Pat. No. 4,018,547 to Rogen which describe the shape memory phenomenon and are incorporated herein by reference. In brief, Nitinol has a temperature above which the memory configuration is set. By holding the Nitinol to a given shape at such temperature (e.g. approximately 900° F. for 55-Nitinol), the memory configuration becomes fixed. Nitinol also has a transition temperature range (TTR) below which the alloy is ductile and may be plastically deformed and above which recovery occurs. Raising the alloy to temperatures above the TTR, then, causes atoms of the alloy displaced during deformation to return their predeformed positions. Accordingly, Nitinol and similar alloys characterized with memory shape can be repeatedly deformed and recovered in alternation by applying pressure to the Nitinol when below the TTR and by heating the alloy to recovery temperatures thereafter. As is known in the art, the TTR, or recovery temperatures, may be determined between -60° F. and +300° F. by proper selection of alloy.
In the preferred mode, the shape memory layer 112 acts to open the tube 104. The tube 104 is closed by a spring force provided by the layer 114. The spring force is sufficient to close the tube 104 when the shape memory layer 112 is ductile and soft (below the transition temperature of Nitinol, for example) but is overpowered by the shape memory layer 112 upon recovery thereof. Alternatively, although not preferred, the tube 104 may be deformed closed by means of a tool, if the layer 114 is not desired or provided.
Although the connector 100 may vary greatly in dimensions based on use, sample dimensions include: an outer diameter of 0.120 inches for the tube 104 when closed, a 0.020 inch thickness of layer 112, a 0.015 inch thickness of layer 114, an inner "diameter" of the tube 104 (when open) of 0.022 inch and a plastic layer 106 having dimensions of a conventional flexstrip.
FIGS. 2 through 5 illustrate the operation of the connector 100. In FIG. 2, the connector 100 is closed (by the layer 114) with the upper lip 108 of tube 104 abutting the lower lip 110. In FIG. 3, the tube 104 is opened by heating the shape memory layer 112 to enable the second strip 150 with its enlarged edge 176 to be inserted as shown in FIG. 4. The heating is provided by heater 120. Other sources of heat may also be employed. Discontinuing the heating results in the closure of the upper lip 108 and lower lip 110 with the second strip 150 therebetween. The window 174 (see FIG. 1) of the second strip 150 is aligned with the upper lip 102--and a corresponding window along the lower layer 154 (see FIG. 1) is also aligned with the lower lip 110 following insertion and closure. By providing windows along the upper lip 108, the conductors 130 through 134 are pressed against the conductors 160 through 164, respectively, making electrical contact therewith. Similarly, by providing windows along the lower lip 110, the conductors 136 through 140 are pressed against the conductors 166 through 170, respectively, making electrical contact therewith.
In FIG. 6, one embodiment of a first strip 200 is shown before it is structured as in FIG. 1. FIG. 6 shows two windows 201 and 202 which lie along the upper lip 108 and the lower lip 110, respectively, when formed as FIG. 1. Connectors 204 through 216 are embedded in flexible plastic 218. These conductors 204 through 216 may be considered to lie along the "upper" layer of the first strip as illustrated in FIG. 1. The conductors 204 through 216 end just beyond the window 201. Conductors 224 through 236 similarly end just beyond the window 202. Also embedded in the plastic 218 is a heater element 240 with leads connectable thereto to produce heating.
FIG. 7 shows an embodiment of the second strip 300 formable into a structure like that shown in FIG. 1 by folding along line K. One window 301 is shown exposing conductors 304 through 318 embedded in the "upper" layer 320 of plastic 322. Conductors 324 through 338 are provided in the "lower" layer 340 being exposed through window 302.
FIG. 8 shows a perspective of a connector formed from a first strip 200 as in FIG. 6 and the second strip 300 as in FIG. 7. FIG. 8 shows a double connector wherein conductors 206' through 210' are separate from--i.e. do not extend into--conductors along the lower plane, e.g. conductors 224 through 236 of FIG. 6, and wherein conductors 308' through 312' do not extend into conductors along the lower plane such as conductors 324 through 338 of FIG. 7. Accordingly, six conductors (as illustrated) of the first strip 200' can separately and distinctly connect to six conductors of the second strip 300'. That is, there is an upper plane of connections that can be made (by pairs 206'-326', 208'-328', 210'-330') and a similar lower plane of connections that can be made.
Turning to FIG. 9, a second strip 400 for use in a single connector is shown. Specifically, each conductor 406 through 420 in the upper layer 422 folds back to extend along the lower layer 424 when the second strip 400 is creased along line L--L. In the single connector, each conductor of the first strip (not shown) also extends the length of the plastic--each conductor 406 through 420 being exposed through both windows 430 and 432 to make electrical contact with a corresponding conductor of the first strip.
Hybrid embodiments which vary from the above two embodiments--the single connector and double connector--may include maintaining some of the conductors on the upper surface of the second strip while other conductors on the upper strip extend into conductors on the lower strip.
Also, it is envisioned that all conductors along the upper strip extend into the conductors along the lower strip of the second strip whereas all conductors in the upper plurality of the first strip do not extend into conductors in the lower plurality. Accordingly, two pairs of lines connected respectively, to the upper plurality of the first strip and to the lower plurality of the first strip may be interconnected upon closure against the second strip, as well as providing connection between the conductors on the first strip and second strip.
In FIGS. 10 and 11, a cover 500 is shown enclosing a tube 502 with shape memory layer 504, stainless steel layer 506, heater 508, and plastic layer 510. The cover 500 has a slot 512 for receiving the second strip 514 with a locking edge 516.
According to the invention, conductors along the first strip engaging corresponding conductors along the second strip to make electrical contact therewith. When the conductors are embedded in, or covered by, plastic windows are required to enable the contact. If the conductors lie along or protrude from the plastic rather than being embedded totally within, the windows may not be required. | A common problem in the art of connecting two electrical components is the providing of a convenient and effective zero insertion force coupling therebetween especially where a plurality of parallel conductors along one component are to be connected with a corresponding plurality along the other. The present apparatus and method address this problem by providing a split tube edge along one of the two electrical components, the split tube including a memory shape material therein. When the split tube is opened, the second electrical component is inserted therein whereupon the split tube can be closed. Conductors along the split tube make contact with corresponding conductors along the second component when the tube is closed. The memory shape material in the split tube acts to either open the split tube or close the split tube when the material reaches a characteristic transition temperature. | 7 |
BACKGROUND OF THE INVENTION
This invention relates generally to an ink-on-demand type ink jet printer head in which ink droplets are jetted through a nozzle for printing. A variety of ink-on-demand type ink jet printer heads have been proposed in the prior art. Typical examples of such ink jet printer heads are the Kyser apparatus, described in U.S. Pat. No. 3,946,398, and the Stemme apparatus, described in U.S. Pat. No. 3,747,120.
The Kyser system is briefly described with reference to FIG. 1 wherein the apparatus includes an electromechanical transducer 1 having piezoelectric elements 2,3. The transducer 1 is disposed in a recess 4 formed in a substrate 10 thus forming one side wall of a pressure chamber 7 for holding ink. A substrate 5 includes an ink supply path 6, the pressure chamber 7 and a nozzle 9. In combination, the substrates 5,10 form a ink jet printer head. When an input signal is applied to the input terminals 8, the transducer 1 is displaced inwardly as indicated by the broken line and the arrow to decrease the internal volume of the pressure chamber 7, thereby causing an ink droplet to be ejected from the nozzle 9. These are the fundamental design and operating principles of an ink-on-demand type ink jet printer head.
The Stemme apparatus is discussed briefly with reference to FIG. 2, wherein the ink jet printer head includes a piezoelectric element 14, a first pressure chamber 17 which is connected through a path 11 to a second pressure chamber 19 and to a nozzle 13, and an ink supply path 12 for feeding ink from an ink tank (not shown) to the second pressure chamber 19. When an input signal is applied to the input terminals 18, the piezoelectric element 14 is driven so as to decrease the volume of the first pressure chamber 17 causing ink in the chamber 17 to pass through the opening 11 and the second chamber 19, and then to be jetted in the form of droplets from the nozzle 13. This is the fundamental design and operating principles of the so-called double cavity system.
Ink droplets can be ejected at a high frequency and a plurality of chambers, nozzles, and driving transducers can be arranged in a single compound head to provide a row or several rows of closely spaced dots in the known manner. However, at high printing rates, for example, in excess of 500 Hz, an ink layer forms on the front face of the ink jet printer head in the vicinity of the nozzle openings. The droplets ejected from the nozzles pass through the surface ink layer and are deflected in their path. For this reason these ink jet printer heads suffer a disadvantage in that print quality is degraded. That is, the printing intervals are not regular because the ink droplets are ejected along a slanted or deviant axis from the axis of the nozzle. Furthermore, this makes it necessary that the ink jet printer head, and more particularly, the nozzles, to be set as close to the printing sheet or other recording medium as possible so as to minimize the dot shift due to the slanted trajectory of the droplets.
What is needed is an ink jet printer head which ejects ink droplets at a high frequency without dot shifting so that print quality is high and the nozzle openings need not be very close to the medium being printed upon.
SUMMARY OF THE INVENTION
Generally speaking, in accordance with the invention, an ink jet printer head especially suitable for high speed on-demand printing is provided. The ink jet printer head for printing dots on demand on a recording medium has ink flow paths formed in a substrate. The ink flow paths include a pressure chamber, an ink supply path and a nozzle for discharging ink droplets, the nozzle terminating in an external front face of the printer head. A piezoelectric element acting on the pressure chamber to reduce chamber volume, causes an ink droplet to be ejected. Ink flow in the paths is perpendicular to the displacement of the piezoelectric element. The front face of the printer head is adapted to contour the ink layer which forms on the front face to assure that the droplets are ejected along the line which is a linear, parallel extension of the longitudinal nozzle axis. Generally, speaking the ink droplet must pass through the ink layer perpendicular to the meniscus between the ink layer and the ambient air if a shifting in the trajectory of the ink droplet is to be prevented. This is accomplished by providing a physical symmetry around the nozzle opening. The design principles are applicable to ink jet printer heads having single or double rows of nozzles. In a multi-row nozzle arrangement, a layer which is non-affinitive, that is, non-wetting, relative to the ink, is provided between two rows of nozzles or a recess is provided between the nozzle rows so as to suitably contour the ink layer around the nozzle openings and assure a straight trajectory for the droplets.
Accordingly, it is an object of this invention to provide an improved ink jet printer head discharging ink droplets from a nozzle along a trajectory which is a linear, parallel extension of the longitudinal axis of the nozzle.
Another object of this invention is to provide an improved ink jet printer head which provides a regular printing pattern at high printing speeds by eliminating dot shift.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.
The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts which will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawings, in which:
FIGS. 1 and 2 are sectional views of ink jet printer heads in accordance with the prior art;
FIG. 3 is a sectional view of an ink jet printer head which is an improvement on the prior art of FIGS. 1 and 2;
FIG. 4 is a sectional view of an ink jet printer head in accordance with this invention;
FIG. 5 is a partial view of an alternative embodiment of an ink jet printer head in accordance with this invention;
FIG. 6 is a sectional view of another embodiment of an ink jet printer head in accordance with this invention;
FIG. 7 is a plan view of a multi-nozzle ink jet printer head with vibration plate and transducers omitted;
FIG. 8 is a partial sectional view of the ink jet printer head of FIG. 7;
FIG. 9a is a portion to an enlarged scale of the ink jet printer head of FIG. 8;
FIGS. 9b and 9c are views to a further enlarged scale of the nozzle portion of FIG. 9a;
FIG. 10 is a partial front view to an enlarged scale of an ink jet printer head in accordance with this invention;
FIG. 11 is a sectional view taken along the line 11--11 of FIG. 10;
FIG. 12 is a view similar to FIG. 11 of an alternative embodiment of a multi-nozzle ink jet printer head in accordance with this invention;
FIG. 13 is a partial sectional view of another alternative embodiment of an ink jet printer head in accordance with this invention;
FIG. 14 is another alternative embodiment of an ink jet printer head in accordance with this invention; and
FIG. 15 is a graph showing the effect of particular physical parameters on dot shift in the ink jet printer head of FIG. 14.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The prior art ink jet printer head of FIGS. 1 and 2 demonstrate the fundamental principles of operation. In order to provide a practical apparatus, it is necessary to simplify the mechanism, to increase the effects of mass production and to thereby decrease the manufacturing cost. An ink jet printer head as shown in FIG. 3 is constructed to satisfy these requirements. In the ink jet printer head of FIG. 3, a pressure chamber 23 is formed deeper into a main substrate 21 than are an ink supplying path 22 and a nozzle 24. These elements are formed by a photo etching technique, or the like, preferably by a two-step etching technique. A flat substrate 25, that is, a vibration plate, is joined to the main substrate 21 by welding or bonding to form the ink jet printer head. A piezoelectric element 26 is attached to the flat substrate 25 in alignment with the pressure chamber 23. Input terminals 27 are provided to the electrodes on the piezoelectric element 26 in the known manner.
When an input voltage signal is applied to the piezoelectric element 26, ink droplets are jetted from the nozzle 24 to achieve printing. When the printing response frequency exceeds 500 Hz, that is, there is a capability to eject more than 500 droplets per second, an ink layer 28 forms on the front face 20 of the nozzle 24. As a result of the surface tension of the ink layer 28, an ink droplet 29 which is ejected from the nozzle 24 travels along a path 31 which is inclined downwardly (FIG. 3) from a path 30 which is a parallel linear extension to the longitudinal axis of the ink jet nozzle 24. The inclination of the line 31 from the line 30 is determined from the thickness of the ink layer 28, the velocity of the ink droplet 29 and the characteristics of the ink. Because of these factors, the ink jet printer head suffers from a problem of maintaining print quality in that the printing intervals are not regular when the ink droplets are jetted along a slanted axis. Furthermore, it is necessary with this ink jet printer head for the nozzle 24 to be set as close to the printing sheet as possible in order to minimize the dot shift resulting from the slanted paths of the droplets.
An ink-on-demand type ink jet printer head can be readily constructed in the form of a multi-nozzle type ink jet printer head. Using a simple technique such as photo-etching (FIG. 7-9), three side walls are formed for each flow path on both sides of a main substrate 41. The remaining side wall, not formed in the substrate 41 is formed by connecting a vibrating plate to both sides of the main substrate 41. Addition of the vibrating plate 42 completes a flow path including paths 50 and chamber 43 as well as the nozzle 45. A piezoelectric element 44 is bonded to the vibrating plate 42 in correspondence with each pressure chamber 43 along a flow path 50. Ink droplets are ejected through the group of nozzles 45 by applying a voltage to the selected piezoelectric elements 44 to achieve printing in the known manner.
If the printing response frequency exceeds 500 Hz, an ink layer 46 (FIG. 9a) forms on the front face 47 of the nozzles 45. As a result, ink droplets 52a are ejected along inclined paths 52 which are slanted inwardly from the jet axes 51 due to the surface tension of the ink layer 46. Ideally, droplets 51a travelling along the paths 51 parallel to the longitudinal axis of the nozzles 45 are desired. The angle of inclination between the desired and the actual jet path for the droplets is determined by the thickness of the ink layer 46 at the nozzle, the velocity of the ink droplets, and the characteristics of the ink.
Because the ink droplets travel along the inclined paths 52 rather than the parallel path 51, a conventional multi-nozzle ink jet printer head suffers from the disadvantage that printing at regular printing intervals cannot be achieved. Morover, in this construction, as shown in FIG. 9b, when the volume of the pressure chamber increases after the signal is removed from the piezoelectric element, and the pressure chamber draws in ink from the ink tank (not shown) after an ink droplet has been ejected from the nozzle, the position of the meniscus 100 between the ink and the air at the top end of the nozzle moves inward of the front face 47 of the nozzle 45 and thereafter the meniscus stops in the position where the forces on the meniscus are balanced with atmospheric pressure. However, when there is a large amount of ink in the ink layer 46 the opening at the top end of the nozzle 45 is subsequently covered with the ink of the ink layer 46 and air bubble 101 is formed in the nozzle 45. When this air bubble 101 is present in the nozzle 45 and the volume of the pressure chamber is reduced at the next printing signal which drives the piezoelectric element, no ink droplet is ejected from the nozzle and some dots are missing from the printed product. As a result, proper letters cannot be formed.
An object of this invention is to provide an ink jet printer head wherein the above described problems have been resolved, that is, there is no dot shift and the distance between the nozzle and a printing sheet can be made longer.
In an ink jet printer head in accordance with this invention, an ink flow path including a supply path, a pressure chamber and a nozzle is formed between a plurality of substrates. The substrates are arranged such that the ink flow path extends substantially perpendicularly to the direction of displacement of the pressure chamber wall for the ejection of ink. The flow path is also substantially perpendicular to a front face of the ink jet printer head from which the nozzles discharge the ink droplets when the piezoelectric element is driven.
Further, in an alternative embodiment of an ink jet printer head in accordance with this invention, a plurality of nozzles and flow paths are provided and flow paths and pressure chambers and nozzles are formed on both sides of the main substrate. A front face of the ink jet printer head is substantially perpendicular to the longitudinal axes of the nozzles. The nozzles are arranged on both sides of the main substrate in such a manner that one group of nozzles is formed in a line on one side of the main substrate while another group of nozzles is formed in a second line on the other side of the main substrate. A layer is provided on the front face between the two groups of nozzles. The layer is of a substance which stays free of ink, that is, there is a non-affinity between the ink and the layer. The ink does not wet the layer surface. The width of the ink-free layer on the front face of the ink jet printer head having the nozzle discharge openings thereon, is defined such that the distance between the nozzles and one side edge of the front face substantially equals the distance between the nozzles and the closest edge of the ink free layer.
In an alternative embodiment of an ink jet printer head having two rows of ink jet nozzles, the ink free layer may be omitted and a recess formed in the front face of the ink jet printer head between the two lines of nozzles is provided. In this embodiment, the configuration of the recess is defined such that the distance between the nozzles and the closest side edge of the front face of the ink jet printer head is substantially equal to the distance between the nozzles and the closest edge of the recess.
In another embodiment of an ink jet printer head, in accordance with this invention, the distance between the closest side edge of the front face of the ink jet printer head and the nozzles is at least 0.3 mm. This may be done with auxiliary plates joined to the vibrating plates on the main substrate.
In another alternative embodiment of an ink jet printer head, in accordance with the invention, the objective to eliminate dot shift is met by setting a ratio of the distance between the nozzles and one side of the front face of the ink jet printer head to the thickness of the main substrate, at a value greater than one.
The several above-mentioned embodiments of an ink jet printer head, in accordance with this invention, are explained more fully hereinafter.
Reference is made to FIG. 4, wherein those components which have been previously described with reference to FIG. 3 and perform the same function, are identified with similar reference numerals. In the ink jet printer head of FIG. 4, an auxiliary ring 33 having a small aperture 32 therethrough is coupled to the nozzle 24. The diameter of the aperture 32 is equal to the diameter of the nozzle 24. The auxiliary ring 33 reshapes the ink layer 38 and makes it uniform around the nozzle jet axis. Accordingly, the ink droplet 29 which is ejected when the piezoelectric element 26 is driven, passes only along a path 30, which is a linear parallel extension of the longitudinal axis of the nozzle 24. As a result, there is very little dot shift.
When no auxiliary ring 33 is provided, an ink droplet having a speed of 5 meters per second, after it has moved two millimeters, would have a shift of 80 microns, whereas an ink droplet having a speed of 3 meters per second, after it has moved 2 mm, would have a shift of 400 microns. On the other hand, in an ink jet printer head, in accordance with the invention, where the auxiliary ring 33 is provided, the ink droplets have very little deflection and accordingly, there is very little dot shift which is caused. The inside and outside diameters of the ring differ by at least 0.3 mm.
It should be noted that the layer 28 does not deflect the droplet from its intended course when the droplet passes through the meniscus between the air and the layer 28 at a portion of the meniscus which is perpendicular to the longitudinal axis of the nozzle 24. The concentric positioning of the auxiliary ring 33 around the nozzle causes the liquid layer 28 to take a symmetrical shape due to surface tension concentric with the nozzle 24. In FIG. 4, t1=t2 and the opening 32 is concentric within the auxiliary ring 33.
In the above described embodiment (FIG. 4) the auxiliary ring 33 is employed. However, the invention is not limited to such a ring. That is, the same effect can be obtained by using auxiliary plates with thickness t1 approximately equal to t2. Furthermore, a portion of the main substrate 21 where the nozzle is formed may be cut off as shown in FIG. 5 so that the equality of t1 with t2 is maintained without the use of an auxiliary ring. All that is necessary is to modify the front face of the ink jet printer head where the nozzle discharges so as to maintain t1≈t2.
Another alternative embodiment of an ink jet printer head, in accordance with this invention, is shown in FIG. 6 wherein those components which have been described with reference to FIGS. 3 and 4 are given similar reference numerals. In the ink jet printer head of FIG. 6, the flat substrate 25, that is, the vibration plate to which the piezoelectric element 26 is attached, is extended by a distance t3 from the front face of the main substrate 21. As a result, the ink layer 28 forms with uniform thickness in the vicinity of the nozzle discharge opening. In this embodiment, the ink droplet 29 follows a trajectory 30 which is the linear parallel extension of the longitudinal axis of the nozzle 24. Very little dot shift occurs. The dimension t3, which is related to the thickness of the ink layer 28, the velocity of the ink droplet 29, the characteristics of the ink, and the structure of the head cannot be specifically defined lacking this specific data except on a case-by-case basis. However, the dimension t3 is greater than zero.
The above described embodiments of the ink jet printer head, in accordance with the invention, are readily produced by extruding plastic material although the configuration of the components around the nozzle is somewhat intricate. As is apparent from the above description, the ink jet printer head is so designed that ejected ink droplets pass along a line which is a linear parallel extension of the nozzle longitudinal axis. Thus, an ink jet printer head, in accordance with the invention, prints letters and characters with a high print quality and is free from dot shift.
An alternative embodiment of an ink jet printer head, in accordance with the invention, is shown in FIGS. 10 and 11 wherein the ink jet printer head is of the multi-nozzle type. As seen in FIG. 10, the nozzles 45 are arranged in two vertical lines and are formed into opposite sides of the main substrate 41. The fourth wall for the nozzles 45 is provided by vibration plates 42 which are attached to the sides of the main substrate 41. The nozzles connect to pressure chambers and feed paths as previously described and piezoelectric elements are mounted on the vibration plates 42 in locations corresponding to the pressure chambers formed in the main substrate 41, all as previously described.
The main substrate 41 is glass having a thickness th=1.27 mm and the flow paths 50 are formed in to both sides of the main substrate 41 to a depth of approximately 100 microns using a photo-etching technique. In each flow path, a nozzle 45 and a filter (not shown) of approximately 20 to 30 microns in depth are formed using a 2-step etching technique. The vibrating plates 42, having a thickness t4 of approximately 0.1 to 0.3 mm, are thermally fused to each side of the main substrate 41. The front face 47 is polished at the nozzles. A layer 71 which is non-affinitive to ink, that is, remains free of ink, is provided on the central portion of the front face 47 of the main substrate 41 and is substantially flush with the front face 47 as best seen in FIG. 11.
FIG. 10 is a front view of the ink jet printer head looking at the front face 47, ink repelling layer 71 and the discharge openings of the nozzles 45. The width of the non-affinitive layer 71 is established such that the distance t4 between the nozzle 45 and the outer side edges 80 of the vibrating plates 42 is substantially equal to the distance t5 between the nozzle 45 and the nearest edge of the layer 71 which is non-affinitive to ink. In other words, the nozzles 45 are centered in a region where a layer of ink forms during high frequency printing. Therefore, a plane 82 which is tangent to the interface between the ink layer 46 and the air at the intersection with the longitudinal axis of the nozzle is substantially parallel to the front face 47 as shown in FIG. 11. Accordingly, the ink droplets pass through the meniscus of the ink layer 46 in a substantially perpendicular intersection, and the ink droplet is not deflected from a path which is a linear parallel extension of the longitudinal axis of the nozzle 45. Dot shift does not occur.
As an example, if a water-based ink is used in the ink jet printer head, the layer 71 which does not have an affinity toward the ink, is readily produced by coating, spraying, or vacuum depositing a plastic, such as, Teflon. In FIG. 10, the nozzles are spaced apart laterally by an integer number of times of the spacing between dots in a horizontal row of a character printed by a combination of dots. In the vertical direction, the dots in both rows are equally spaced apart. However, the nozzles 45 are staggered such that the nozzles in one row are aligned to the half pitch distance, that is, the midpoint location of the nozzles in the other row. This staggered arrangement and lateral spacing is not unconventional in an ink jet printer head of the multi-row type.
In the embodiments described above, the vibrating plate 42 forms one sidewall of each nozzle 45. However, at least one sidewall of the nozzle may be formed with a different material. Further, in the described embodiments, the ink flow paths are formed into both sides of the main substrate 41. However, in alternative embodiments of an ink jet printer head in accordance with the invention, the ink flow paths may be formed in the vibrating plates 42 or may be formed in part in both the main substrate 41 and in the vibrating plates 42.
As previously stated, and as is clear from the above descriptions, in an ink jet printer head in accordance with the invention, a plane perpendicular to the longitudinal axis of the ink nozzle and tangent to the meniscus of the ink layer at the point of intersection of said longitudinal axis, is made substantially parallel to the front face 47 where the nozzles discharge. Accordingly, the ink droplets are not deflected from a linear parallel extension of the longitudinal axis of the nozzle. Thus, an ink jet printer head in which no dot shift is caused and in which printing is carried out with a high density and high print quality is provided.
An alternative embodiment of a multi-row ink jet printer head in accordance with the invention is shown in FIG. 12. In this ink jet printer head, a recess 70 is cut into the central portion of the front face 47 of the main substrate 41. The width of the recess 70 is such that the remaining thickness t7 at the nozzle 45 substantially equals the thickness t6 of the vibrating plate 42 which forms the outer wall surface of the nozzle 45. Separate ink layers 46 form at each nozzle 45 with an air/ink meniscus which is symmetrical around the discharge opening of the nozzle 45 as seen in FIG. 12.
When printing is performed and the ink layers 46 are formed, a plane tangent to the meniscus at the intersection of the linear parallel extension of the longitudinal axis of the nozzle 45 with the meniscus, is substantially parallel to the front faces 47 adjacent the nozzles. Accordingly, the surface tension of the ink layer acts uniformly on the ink droplet passing through the ink layer 46. Therefore, the ink droplets are jetted perpendicularly to the meniscus and dot shift is not caused. The depth of the recess 70 is selected such that even when the ink layers 46 flow into the recess 70 as their volumes increase, the ink layers 46 for two rows of nozzles do not connect to each other through the recess.
In an alternative embodiment of an ink jet printer head in accordance with the invention, as shown in FIG. 13, auxiliary plates 72 are thermally fused to the vibrating plates 42 in the region of the discharge openings of the nozzles 45. The auxiliary plates 72 and the front face 47 of the main substrate 41 are polished simultanteously so that a thin ink layer 46 can spread to the outer edges of the auxiliary plates 72. The auxiliary plates 72 extend the width of the front face 47 to such a degree that the ink layer 46 is substantially of one thickness where the discharge openings of the nozzles 45 are located. Tapering in thickness of the ink layer 46 occurs near the outer edges of the auxiliary plates 72. Accordingly, the ink droplets pass in a straight line which is a linear parallel extension of the longitudinal axis of the nozzles 45 and no dot shift is caused.
In the embodiment of FIG. 13, the auxiliary plates 72 are thermally fused with the vibrating plates 42. However, the same result can be achieved by increasing the thickness of an end portion of the vibrating plate 42 which forms the nozzles 45. Then, the thickness of only a portion of the vibrating plate 42 where the piezoelectric element 44 is bonded is decreased. As the width of the nozzle front face 47 is increased, the nozzle openings can readily be made flat by polishing and the nozzles 45 can be easily covered with a lid (not shown).
Another alternative embodiment of an ink jet printer head in accordance with the invention is shown in FIG. 14. Ink flow paths 50, having a pattern similar to that shown in FIG. 1, are formed in both sides of the main substrate 41, which, for example, is glass having a thickness of 0.3 mm, by photo-etching. The flow paths 50 are etched to a depth of approximately 100 microns. In each flow path 50, a nozzle 45 and a filter (not shown) having a depth of about 20 to 30 microns are formed by a two-step etching process. A vibrating plate 42 having a thickness t9, of 0.3 to 1.0 mm is thermally fused to each side of the main substrate 41. The nozzle front face 47 is polished. A piezoelectric element (not shown) is bonded to the vibrating plates 42 in association with each pressure chamber and nozzle, and electrodes are connected to the piezoelectric element in the known manner.
An ink jet printer head was constructed with these dimensions and the thickness t8 of the main substrate 41 and the thickness t9 of the vibrating plate were varied. The ink which was used had a surface tension of 45 dyn/cm and a viscosity of 1.8 c.p. The velocity of the ejected droplets was approximately 3 to 5 meters per second. Results of the tests are indicated graphically in FIG. 15. When the ratio of the vibrating plate thickness t9 to the main substrate thickness t8 exceeds 1, there is very little dot shift as measured at a distance of 2 mm from the discharge opening of the nozzle. When the ratio exceeds 1, the interface between the ink layer 4 and the air (FIG. 14) is substantially perpendicular to the longitudinal axis of the nozzles. Therefore, surface tension in the ink acts substantially uniformly on the ink droplets in both lateral directions. As a result, the ink droplets are ejected along a straight trajectory which is an elongation of the longitudinal axis of the nozzle.
In the ink jet printer head of FIG. 14, the ink flow path have been described as being formed in the main substrate 41 by etching. However, the ink paths may be formed in the vibrating plates 42 be may be formed in both the main substrate 41 and the vibrating plates 42. The thickness of the ink jet printer head may be controlled by using a different material as the vibrating plate 42 which forms one sidewall of the nozzle 45, or one sidewall of the nozzle may be formed using a different material. Thus, an ink jet printer head in which no dot shift is caused and in which printing can be carried out with a high density and a high print quality is provided. Additionally, in an ink jet printer head in accordance with the invention, ink droplets are ejected without producing air bubbles in the nozzles.
It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above constructions without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween. | An ink jet printer head for printing dots on demand on a recording medium has ink flow paths formed in a substrate. The ink paths include a pressure chamber, supply path and nozzle for discharging ink droplets, the nozzle terminating in an external front face of the printer head. A piezoelectric element acting on the pressure chamber to reduce chamber volume, causes an ink droplet to be ejected. Ink flow in the paths is perpendicular to the displacement of the piezoelectric element. The front face of the printer head is adapted to contour the ink layer which forms on the front face at rapid printing rates to assure that the droplets are ejected along a line which is a linear, parallel extension of the longitudinal nozzle axis. The design principles are applicable to printer heads having single or double rows of nozzles. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 08/953,850 filed Oct. 15, 1997, which is a continuation-in-part of U.S. patent application Ser. No. 08/540,255 filed Oct. 6, 1995, now U.S. Pat. No. 5,591,001 issued Jan. 7, 1997, and also a continuation-in-part of PCT Application No. PCT/US96/15336 filed Sep. 24, 1996. All of the above patents and patent applications are hereby incorporated by reference.
FIELD OF THE INVENTION
This invention relates to a centrifugal pump for liquids, and more particularly to a pump which conditions the pumped liquid by introducing and dispersing a second fluid medium into the pumped liquid.
BACKGROUND OF THE INVENTION
Pumps have long been used to introduce and disperse air and other fluid media into a pumped liquid. For instance, pumps have been used for the production of an air and water mixture. The air so introduced facilitates the removal of oil and other pollutants including solid particles which tend to separate out as a surface scum with the introduction of air and liquid to the tank. The aerated liquid produced by the pump of course may be used for other purposes.
It is known in the art that aeration of liquids is a useful procedure relied upon in pollution control operations. A known procedure, by way of example, is the aeration of sewage contained in a holding tank, with such tending to produce separation of pollutants in the liquid in the tank either as a scum or as sediment. A convenient approach for introducing such air would be to introduce air in the desired quantity to the suction or intake side of the pump during a pumping operation, with the pump then tending to produce a mixture of air and liquid which is expelled from the pump. The problem with this approach is that the addition of significant quantities of air to the intake of the pump will cause the pump to lose outlet pressure and stop pumping. Pump performance is also affected. U.S. Pat. No. 3,663,117 to Warren discloses a so-called aeration pump, wherein air is introduced against the front side of a pump impeller in a centrifugal pump, with the impeller vanes therein then producing mixing of the air and liquid pumped to produce aeration of the liquid. Such a system, because of the relatively high pressure condition existing adjacent the periphery of the impeller, requires a source of air at superatmospheric pressure to be supplied to the pump chamber. In another system, the liquid discharged from a pump is supplied to an air saturation tank. This tank is also supplied air from a compressed air source, and the air and liquid are then mixed in the tank. The need for an air compressor and other equipment adds to the complexity and expense of any system requiring a source of pressurized air. All of these methods also only achieve a limited dispersion of the air into the water because of the limited mixing that can occur as they are passed through the pump.
It is also possible to utilize a pump to disperse other fluid, such as gases other than air or another liquid, into the pumpage. U.S. Pat. No. 4,744,722 to Sampi et al., for instance, describes a pump system for introducing liquid or gas into pulp stock. More generally, U.S. Pat. No. 3,948,492 to Hege discloses a system for mixing a second material into a first fluid material by use of a centrifugal impeller.
When introducing a second material into a pumped flow, one of the primary goals is obtaining a good dispersion of the introduced material into the pumped flow. With conventional systems, good dispersion is difficult to achieve because the added material is injected directly into the stream of the pumped liquid and is therefore rapidly carried out of the pump. Prior art systems often attempt to compensate for this deficiency by introducing the second material from a plurality of points. This method of addressing the problem, however, is of limited success and adds significantly to the complexity of the pump and injection system.
It is therefore an object of the present invention to provide a method and apparatus for finely dispersing a fluid material in a pumped liquid.
It is another object of this invention is to provide an improved method and apparatus for conditioning a liquid by the introduction of air into the liquid, with the air on introduction becoming dissolved in the liquid or entrained as a fine dispersion therein.
Another general object is to provide an improved sewage treatment method which utilizes recycled sewage conditioned with air in the treatment process.
Yet a further object is to provide an improved pump operable to produce a mixture of a pumped liquid and a second fluid.
A more specific object is the provision of such a pump, which employs air introduced into a seal chamber in the pump, and structure within the seal chamber producing an air liquid mixture which under the action of the pump impeller moves to the periphery of the impeller and then to the pump discharge.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and advantages are obtained by the invention, which is described herein below in conjunction with the accompanying drawings, wherein:
FIG. 1 is a cross sectional view of a centrifugal pump featuring a construction for a seal chamber in the pump as contemplated by the invention;
FIG. 2 is a schematic drawing illustrating a sewage treatment system utilizing a pump as described and shown in FIGS. 1 and 2;
FIG. 3 is a view of the front of a backplate portion in the pump;
FIG. 4 is similar to FIG. 3 but illustrates a modification of the invention;
FIG. 5 is a cross-sectional view through an alternative embodiment of a pump construction according to the present invention; and
FIGS. 6 and 7 are alternate embodiments of a water treatment system according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, and first of all more particularly to FIG. 1, indicated generally at 10 is a centrifugal pump. The pump has a casing 12. Casing 12 includes a front casing section 14, with an internal pump chamber wall 16 defining a pump chamber having the usual volute configuration. Also part of the casing is a back casing section 18. These two casing sections are secured together in the pump. The back casing section includes a backplate portion 22 and a motor bracket portion 24.
A rotatable impeller 30 located within the pump chamber produces, on rotation, movement of the liquid being pumped or the pumpage. This liquid enters the pump chamber through an inlet opening or intake 32. Pressurized pumpage leaves the pump through pump discharge 34. The impeller has a front 35 and a back 36.
The impeller is detachably mounted, as by a fastener 38, on a forward end of a motor-driven impeller shaft 40. This shaft extends rearwardly, or outwardly from the back of the impeller, to a suitable power means such as an electric motor.
Backplate portion 22 has an inner wall 44, referred to as a seal chamber wall, which in general outline has a conical tapered or flaring shape. This wall and the back of the impeller bound what is referred to as a seal chamber or cavity 46. The seal chamber has a smaller diameter end located directly forwardly of a hub 48. By reason of the taper of the seal chamber wall, the seal chamber enlarges progressing from this end to the opposite or large diameter end of the seal chamber or from left to right in FIG. 1. This is only one type of seal chamber, others are possible.
Hub 48 extends about an opening 50 which receives the impeller shaft. Seal structure exposed to the seal chamber seals the shaft and casing, and this structure comprises a stationary seal 52 and a rotary seal 54 which rotates with the impeller shaft. A compression spring 56 urges the rotary seal against the stationary seal. With the construction described, liquid within the seal chamber is prevented from leaking outwardly past the backplate.
During operation of the pump, part of the liquid being pumped flows into the seal chamber by moving about the periphery of the impeller and across the impeller's outer back margin. It is conventional to utilize this circulating fluid to produce cooling of the seal structure just described.
The back of the impeller may be provided with backvanes indicated at 60. These vanes, when viewed in a direction extending toward the back of the impeller, ordinarily arcuately curve about the axis of the impeller shaft. By the inclusion of these vanes, a swirling action is introduced to the pumpage liquid which circulates in the seal chamber and the pressure in the seal chamber is reduced. Small vanes are often utilized on centrifugal pumps to slightly reduce pressure in the seal chamber to compensate for the axial thrust created on the impeller by the reduced pressure at the inlet to the pump. The backvanes of the present invention, however, are typically substantially larger and/or more numerous than necessary to compensate for the impeller thrust. In particular, the backvanes design should preferably be sufficient to create a subatmospheric pressure in the seal chamber. A number of factors affect the vacuum created in the seal chamber, including the number of backvanes, the backvane diameter and height, the clearance between the backvanes and the casing, the size of the seal chamber, the pump operating speed and the impeller vane outside diameter. Although creation of a sub-atmospheric pressure in the seal chamber is preferred, it is also possible to practice the present invention by introducing air or other fluid at a superatmospheric pressure as well. In this case, back vanes do not need to be designed to create a sub-atmospheric pressure in the seal chamber.
An air- or fluid-introduction passage is provided along the inside of a conduit 72 having one end 72a which opens to the seal chamber and an opposite end 72b which opens to the atmosphere. Indicated at 74 is an adjustable valve which can be adjusted to control the amount of air introduced to the seal chamber by the conduit. Preferably, the opening of the conduit into the seal chamber should be located above the horizontal centerline of the pump to prevent pumpage from leaking back out the conduit. It should be understood that while air is introduced in the preferred embodiment of a dissolved air floatation pump, no limitation should thereby be implied. In particular, it is possible to introduce any fluid substance, including air or other gases, as well as liquids and flowable solids or suspension, into a stream of pumpage utilizing the present invention.
During operation of the pump and rotation of the impeller, pumpage is drawn in through the suction of the pump 32 and discharged at the periphery of the impeller through discharge 34. A negative or subatmospheric pressure is produced in an annular region extending about the impeller shaft adjacent the seal structure for the shaft comprising stationary and rotary seals 52, 54. Spring 56 functions to keep the seal faces in engagement against the action of this negative pressure. The negative pressure is effective to draw atmospheric air into the seal chamber into the negative pressure region through air-introduction conduit 72, with the amount of such air being controllable through controlling the adjustment of valve 74 (or by using a properly sized orifice). As shown in FIG. 5, the air introduction conduit 72 may also be formed in the shape of a bell or venturi 75 to decrease the resistance to air flow and thereby increase the air draw of the pump.
Mixing of this air with the pumpage circulating at the rear of the impeller, and transporting of the mixture outwardly from the seal chamber to the stream of fluid being discharged from the pump at discharge 34, is promoted by agitation structure, which in the preferred embodiment, takes the form of stationary vane structure which is part of back casing section 18.
Further explaining, and referring also to FIG. 3, equally circumferentially distributed about an axis 80 of the impeller shaft are multiple (namely six in the embodiment of the invention illustrated) outer vane segments 86. In frontal outline, as illustrated in FIG. 3, each of these outer vane segments has a shape which roughly may be described as a truncated triangle, and includes a base 86a and opposite sides 86b, 86c. Each vane projects outwardly from the seal chamber wall with its front face 86d extending at only a slight angle relative to a plane perpendicular to the axis of the shaft compared to the slope of the inclined pump seal chamber wall, which extends at a greater angle with respect to this plane. By reason of this incline, each outer vane segment has an increasing height or greater projection from the inclined pump seal chamber wall progressing in a radially inward direction on the seal chamber. Explaining a typical construction, face 86d might extend at an angle of approximately 10° with respect to a plane perpendicular to the axis of the shaft. In comparison, the tapered seal chamber wall might extend at an angle of approximately 35° with respect to this perpendicular plane. These specific values herein are given only as exemplary, and are subject to variation depending upon pump construction.
Distributed circumferentially about the shaft axis are multiple (three in the embodiment shown) inner vane segments 90. These extend inwardly on the seal chamber wall from the inner ends of alternate ones of the outer vane segments. Each inner vane segment has an arcuate, concavely curving base 90a, and opposite sides 90b, 90c, with these sides forming extensions of sides 86b, 86c of an outer vane segment. Sides 90b, 90c diverge from each other progressing in a radially inward direction. A front face 90d of an inner vane segment (refer to FIG. 1) inclines away from the tapered seal chamber wall progressing in a radially outward direction. As a result, these inner vane segments have increasing height increasing radially outwardly on the seal chamber. With the seal chamber wall inclining at an angle of approximately 35° with respect to a plane extending perpendicular to the axis of the impeller shaft, the face of an inner vane segment might incline at a somewhat greater angle with respect to this plane, for example, an angle of 45°.
The sides of the outer vane segments need not join with the faces of these respective vane segments at a sharp angle, but over a slight round, which tends to reduce excessive turbulence in the circulation of pumpage moving over the vanes. As shown in FIG. 5, it is also possible to provide a corrugated ring or washer 98 to further improve mixing in the seal chamber. Washer 98 may have holes, ribs, splits, blades or other structures to increase turbulence and mixing in the seal chamber.
In the pump illustrated, a fluid circulation line or conduit is shown at 102, equipped with a valve 104. The conduit connects at one end with the interior of the pump casing at the periphery of the impeller. The opposite end connects with the seal chamber in the region of the seal chamber having a subatmospheric pressure. By including the circulation line, the amount of pumpage circulated to the seal chamber to be mixed with air may be increased over that which circulates to this seal chamber by moving over the periphery of the impeller. Optionally, liquid may be introduced to the seal chamber by a line connected to a pressurized water source. This is shown in FIG. 4 by the line connecting with the water source labeled "WS." Preferably, the circulation line should enter the seal chamber at the top vertical position to maximize the mixing of air and water. Operation of the circulation line serves to increase the amount of air that can be drawn in through air conduit 72. It is also possible to insert an eductor 105 into circulation line 102 and use the fluid flow to draw air through the eductor to thereby introduce a supply of air into the seal chamber.
Describing the operation of the pump, the vane structure on the back of the impeller together with the normal rotation of the impeller causes pumpage within the seal chamber to swirl about as the impeller rotates. As this pumpage moves over the stationary vane structure projecting from the rear wall of the seal chamber, a vortexing action results tending to move debris, and also mixed pumpage and air, from the region of the seal chamber adjacent the impeller shaft radially outwardly, with this fluid and debris ultimately being expelled from the seal chamber by way of the back vanes 60 to become intermixed with the principal pumpage being pumped by the pump which is being discharged at discharge 34. There is a turbulence in the fluid pumped and a complex mixing arising by reason of vortexing occurring at the periphery of the impeller which enables pump fluid to enter the seal chamber at the same time that fluid mixed with air exits the seal chamber.
As described above, numerous factors affect how much air or other fluid can be drawn into the seal chamber to mix with the pumpage. In general, the outside diameter of the seal chamber should be increased to handle larger volumes of air. Conversely, a smaller seal chamber diameter could be used where less air was to be introduced. However, because the volume of air can be adjusted with other parameters as well, the seal chamber is normally fixed for a given pump casing and the other parameter adjusted because of the complexity of changing the casting for the pump casing. For instance, the outside diameter of the impeller vanes may be reduced to reduce the pumpage flow rate and thereby increase the proportion of air introduced by maintaining all the other parameters constant. Decreasing the impeller vane diameter, because it reduces the pressure around the periphery of the impeller, tends to decrease the pressure in the seal chamber, thereby further increasing the volume of aspiration.
Generally speaking, increasing the number and size of the backvanes, or reducing their clearance, will increase the vacuum generated in the seal chamber. For simplicity of manufacturing, impeller vane and backvane outside diameters are the parameters usually used to control the pressure in the seal chamber. By way of example, for a dissolved air floatation process that required a pump output of 65 psi at 50 gallons per minute of flow rate while aspirating 0.6 scfm, a pump operating at 3525 rpm having a seal chamber outside diameter of 5.06 inches, a backvane height of 0.25 inches and a backvane clearance of 0.03 inches might be used. An impeller diameter of 5.62 inches would generate the required flow rate and a back vane diameter of 8.62 inches would create sufficient vacuum in the seal chamber to aspirated 0.6 scfm of air. If the desired flow rate were to increase to 80 gallons per minute at 65 psi and 0.88 scfm of air, the impeller dimension might be increased to 5.88 inches and backvane diameter increased to 9.0 inches.
Based on empirical testing it is believed that the following equation can be used to facilitate design of a pump which will function according to the present invention:
D.sub.I.sup.2 /(D.sub.O.sup.2 -D.sub.B.sup.2)<(1-C/H)*N.sup.2 /(1+N.sup.2)
where
D I =Diameter of impeller vanes
D O =Outside diameter of backvanes
D B =Diameter of seal chamber
H=Backvane height
C=Backvane clearance
N=Number of backvanes
To first approximation, the right hand is approximately equal to one and therefore it can be generalized that D I 2 /(D O 2 -D B 2 ) should be less than one. More particularly, it is preferred that D I 2 /(D O 2 -D B 2 ) should be between 0.4 and 0.9 and most preferably between 0.7 and 0.9. The above equation may not apply if the material to be mixed in the pumpage stream were supplied under pressure rather than being drawn into the seal chamber.
A sewage system which utilizes the pump as described is illustrated in FIG. 2. Referring to this figure, a tank for containing a volume of sewage is illustrated at 110. Sewage is introduced to the tank from a raw sewage feed 114 introducing the sewage to the tank through a header box 116.
Effluent from the tank is removed through a conduit 120. A portion of this effluent is recycled through a conduit 122 to the intake of pump 10 above described. Fluid discharged from this pump travels through a conduit 124 to be returned to header box 116 and reintroduced to tank 110 through a conduit 126.
Air is introduced to the effluent through conduit 72.
Air introduced into the pump through operation of the impeller is thoroughly mixed with the liquid sewage. Much of the air is mixed to become dissolved in the liquid sewage. Air not actually dissolved is felt to be contained in the liquid in the air bubbles sized below 150 microns.
The introduction to the tank of the recycled stream of sewage containing dissolved air and air dispersed as finely entrained bubbles, has the effect, as earlier discussed, of producing a separation in the tank, with pollutants separating as a sludge which, if floating, can be removed from the tank as a drawoff.
The system in FIG. 2 can be further simplified by introducing the air into the pump supplying the raw feed, thus eliminating the need for a recycle flow, and further reducing the complexity of the system.
FIG. 6 illustrates an alternative recycling treatment system utilizing a pump 10 according to the present invention. In particular, the recycling system includes input line 130 feeding waste to a flocculator 132. Flocculator 132 includes a mixer and a polymer input 134 is provided either directly into the flocculator or just upstream in the input line. After flocculation, a feed pump 136, or in gravity flow in some cases, transfers the waste stream into a settling tank 138. Tank 138 includes upper and lower waste remove ports 140, 142, respectively through which floated and settled solids may be removed. Tank 138 further includes a clean effluent output 144, which branches into a recycle line 146. The recycle line is fed through pump 10 where it is aerated and passed on back to the tank. A valve 148 regulates the return flow from the pump back into the tank. The present system eliminates the need for an air saturation tank that is normally required in the return line.
In some cases it may be desirable or beneficial to add flocculent or other chemicals, such as buffers, enzymes or pH modifiers, to the system in the recycle line rather than or in addition to the flocculator. In this case, the chemical could be introduced directly into DAF pump 10 or upstream or upstream of the pump in the recycle line. For instance, an additional port may be provided to the subatmospheric region behind the impeller to draw in the chemical. By introducing any such chemicals in or upstream from the DAF pump, passage of the chemical and waste stream through the pump enhances the mixing of the chemicals and the waste stream. This is particularly true where the chemical is introduced into the seal chamber.
FIG. 7 illustrates a total pressurization treatment system utilizing a pump 10 constructed according to the present invention. This system includes an input line 160 which connects directly to the input of pump 10. A polymer input 162 is provided either upstream of the pump or into the seal chamber to allow delivery and mixing of polymer into the waste stream. If the polymer input is upstream of the pump, the polymer is mixed with the waste stream as both flow through the impeller. Alternatively, if the polymer is introduced into the seal chamber, it is mixed in with the air and water that are agitated in the seal chamber. This mixture is then introduced into the main flow around the periphery of the impeller. Flow proceeds from the pump through regulating valve 164 and into a settling tank 166. Settling tank 166 includes upper and lower waste removal ports 168, 170, respectively, through which floated and settled solids may be removed. Clean effluent is then discharged through an output port 172.
With the pump construction described, appreciable quantities of air may be introduced into the pumpage with introduction of air in an amount exceeding approximately 15% by volume of the pumpage handled having been attained. It is possible to further increase the amount of air introduced by utilizing a pressurized source of air. Because the power requirements for driving the pump drop somewhat with the introduction of additional air, it may be beneficial under some circumstances to attach a belt-driven compressor to the pump to supply additional air. With this structure, it may be possible to achieve a greater horsepower reduction in the pump than is required to operate the compressor, thereby increasing overall efficiency and the amount of air introduced. It is expected that introducing additional air, as with a compressor, may reduce the fineness of the dispersion achieved, which may not be desired under some circumstances.
More generally, a number of different variables affect efficient operation of a pump constructed according to the present invention. It is generally preferred that the discharge valve between the pump and the tank be located as close as possible to the tank so that the pumpage remains pressurized until entry into the tank. A valve in the suction piping can be used to regulate the pressure at the suction of the pump. Obstructions, such as flow meters or other devices, should be avoided in the discharge piping between the pump and the tank. Likewise, any changes in pipe diameter should occur gradually to avoid sudden transitions that may cause the microbubbles to come out of solution. Preferably, the discharge piping should be level or inclined upwardly toward the tank to avoid formation of an air bubble at the output of the pump. A stand pipe or other type of air collection device should be provided in the discharge piping to bleed of excess air that does not go into solution.
The discharge piping should be sized to provide a flow velocity of one to two feet per second. Moreover, the length of the discharge piping should provide about ten seconds of retention time from the discharge of the pump to the discharge valve. More or less length may be required depending on the process. Likewise, the velocity in the piping can be varied to achieve different results.
While an embodiment of the invention has been described, it is obvious that variations and modifications are possible without departing from the instant invention as claimed herein. | A system for dissolved air floatation treatment of a liquid stream where the system includes a pump having an impeller cavity with input and output ports, and an impeller with an eye disposed adjacent the input port. The impeller draws liquid through the input port and drives the liquid toward the output port and creates a subatmospheric pressure zone in the cavity away from the eye. The pump includes an air introduction port opening into the subatmospheric zone to introduce significant quantities of air into the cavity for mixing with the liquid stream. The system also includes a tank adapted to receive the liquid stream from the pump with dissolved air introduced therein. | 8 |
FIELD OF THE INVENTION
[0001] The present invention relates to new and useful solution-based precursors for use as starting materials in film deposition processes. The present invention particularly relates to solution-based precursors that can be used in atomic layer deposition (ALD), chemical vapor deposition (CVD) and metalorganic chemical vapor deposition (MOCVD) processes for the deposition of thin films for semiconductor devices.
BACKGROUND OF THE INVENTION
[0002] Moore's law describes a long-term trend in the history of computing hardware. In particular, since the invention of the integrated circuit in 1958, the number of transistors that can inexpensively be included in an integrated circuit has increased exponentially, doubling about every two years. This trend was first reported on by Gordon E. Moore in 1965 and has continued to the present. One view is that this scaling trend will continue for another decade. A second view is that additional functionalities will be required and that simple scaling is near an end, “more than the Moore”. In either case, new materials and new device structures are emerging to meet the challenges posed by the technology and economic considerations.
[0003] The capabilities of digital electronic devices, such as processing speed, memory capacity, the number and size of pixels in digital cameras, etc, are strongly linked to Moore's law, with all such capabilities improving at roughly exponential rates as well. This increase in capability has dramatically increased the usefulness of digital electronics in nearly every segment of the world economy.
[0004] In order to continue the trend for semiconductor chip integration in accordance with either Moore's law or the “more than the Moore” viewpoint, it will be necessary to use new materials incorporated with silicon-based IC chips. These new materials will need to provide enhanced chip performance as well as help reduce unit cost.
[0005] Numerous group 2 and transition (group 3 10 12 ) metals have been suggested in recent years as candidates for providing critical functionalities in electronic devices. However, precursors for group 2 and transition metals are generally solid materials that are difficult to use in vapor phase deposition processes, such as ALD, CVD and MOCVD processes. In ALD processes, the requirements for precursor materials are far more stringent than the requirements for precursors used in CVD or MOCVD processes. In particular, any precursor decomposition or self-growth without a co-reactant can result in quality issues, such as higher impurity and non-uniformity in the film. Decomposition occurs at elevated temperatures for some standard amine based liquid precursors. Strong inter-molecular and intra-molecular interactions of and for some thermally stable solid precursors could result in polymerization and self-growth often occurs during the thin film growth. Furthermore, some of those solid precursor materials suffer decomposition or solidification when heated in attempts to sublimate measurable vapors for use in deposition of thin specialty films on a semiconductor wafer.
[0006] Therefore, there is a need in the art for improvements to precursors for use in vapor phase deposition processes.
SUMMARY OF THE INVENTION
[0007] The present invention provides new solution-based precursors for use in vapor phase deposition processes, such as ALD, CVD and MOCVD processes. The solution-based precursors according to the present invention do not decompose or solidify during vaporization and are therefore ideal for use in vapor phase deposition processes. If solution formulations such as those of the present invention are not used, many solid precursors by themselves can not be employed in vapor phase deposition because of decomposition or solidification in a sublimating source at elevated temperatures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a graph showing thermogravimetric analysis results for a solid precursor material.
[0009] FIG. 2 is a graph showing thermogravimetric analysis results for a solution-based precursor material according to the present invention.
[0010] FIG. 3A-3D are graphs showing the changes in vaporization behavior dependent on the use of different solvents according to the present invention.
[0011] FIG. 4 is a graph showing the self-limiting growth characteristics achieved by using precursor material according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0012] The present invention relates to new solution-based precursors for use in vapor phase deposition processes. A number of solid zirconium complexes were studied. In particular, (MeCp) 2 ZrMe 2 , (Me 5 Cp) 2 ZrMe 2 , and (t-BuCp) 2 ZrMe 2 , wherein Me is methyl, t-Bu is t-butyl and Cp is cyclopentadienyl, were investigated. FIG. 1 is a graph showing the thermogravimetric analysis results for solid (t-BuCp) 2 ZrMe 2 . As can be seen in this graph, while there is an initial weight loss upon heating of the solid material, probably because of the gradual removal of methyl or other hydrocarbon groups, there is also a high level of residue indicating decomposition and solidification of the material. In particular, for solid (t-BuCp) 2 ZrMe 2 , the non-volatile residue remains about 65% of the initial weight. This shows that the solid form of this material would not be suitable as a precursor for vapor phase deposition processes.
[0013] In accordance with the present invention, materials that are unsuitable for vaporization in their solid form have been found to be acceptable precursor materials when first dissolved in a suitable solvent. For example, (t-BuCp) 2 ZrMe 2 was dissolved in a purified solvent, such as n-octane, as room temperature. Solubility of the solid is greater than 0.2M and solution concentration for deposition applications such as ALD, is from 0.05M to 0.15M, preferably 0.1M. The solvent is preferably oxygen-free.
[0014] This solution was then studied by thermogravimetric analysis and the results are shown in FIG. 2 . Because of the solvent effect, the dissolved precursor material is vaporized without forming solid residue, and final residue amount is less than 2% of the original solute weight. This solvent effect protects the precursor molecules in both dissolved phase and in vapor form. In the solvent rich environment, the precursor molecules are encapsulated and left together without losing methyl or other hydrocarbon groups at the vaporization temperatures. By further matching of solvent and precursor properties according to the present invention, a continuous vaporization curve can be achieved without any residue formation. FIG. 3 shows the systematic vaporization behavior changes depending on different solvents used. In particular, as solvent and precursor boiling points (as shown in FIG. 3 ) and other physical properties get closer to each other, a single, more uniform weight loss curve can be achieved. FIG. 3A shows that when solvent boiling point is much less than precursor boiling point, the result is an initial weight loss that reaches a minimum level, thus leaving a significant amount of precursor in non-vaporized form. FIGS. 3 b and 3 C show that as solvent boiling point approaches precursor boiling point, the weight loss curve becomes more singular and achieves nearly total vaporization of the precursor. FIG. 3D shows that when precursor boiling point is much higher than solvent boiling point, that almost no vaporization of the precursor occurs. Therefore, by carefully matching precursor and solvent physical properties, precursor vaporization can be optimized, although the acceptable window is relatively wide as shown by FIGS. 3B and 3C . Solvent based precursors of the present invention exhibiting these properties are suitable for any vapor phase deposition process, including ALD, CVD and MOCVD processes.
[0015] The solvent should be inert to the precursor to avoid any reaction between them during the thermal processing. Hydrocarbon based solvents, such as alkanes, alkenes, alkynes and aromatics are preferred.
[0016] Delivery of the solution-based precursors of the present invention can be carried out at room temperature using a direct liquid injection to a point of use vaporizer. The solution may then be vaporized and delivered to the deposition chamber without decomposition or solidification of the precursor. For example, for an ALD process, the hot vapor from the vaporizer is pulsed into the deposition chamber using inert gas pressure switches to achieve an ideal square wave delivery. The vaporizer can be operated at a temperature between 150° C. and 250° C., and preferably about 190° C. By matching the solvent and precursor according to the present invention, the solvent effect allows for complete vaporization of the precursor material at these temperatures with no residue left in the vaporizer. This is important in controlling the dose amount of precursor to the deposition chamber, particularly for ALD processes.
[0017] By alternatively delivering the metal precursor and an oxygen precursor, it is possible to form thin oxide film on a substrate in the deposition chamber. For example, a ZrO 2 film can be formed using a metal precursor such as the solution-based (t-BuCp) 2 ZrMe 2 precursor of the present invention and an oxidant precursor, such as water vapor, ozone or another oxygen containing gas or vapor. In particular, oxidant precursors can be water vapor, H 2 O 2 , O 2 , O 3 , N 2 O, NO, CO, CO 2 , CH 3 OH, C 2 H 5 OH, other alcohols, other acids and other oxidants. In a similar manner metal nitride films can be formed by using a metal precursor according to the present invention together with a nitrogen containing reactant such as NH 3 , N 2 H 4 , amines, etc. Also, the metal precursors of the present invention can be used to form metal films by using hydrogen, hydrogen atoms or other reducing agents as the second precursor.
[0018] In one example according to the present invention, a zirconium oxide film is deposited by ALD using a (t-BuCp) 2 ZrMe 2 precursor dissolved in n-octane and water vapor from a de-ionized water source. Saturation of growth can be observed by increasing either the Zr precursor or water dose, indicating self-limiting ALD growth, as shown in FIG. 4 . No self-growth is observed when the oxidant is absent. Film growth is carried out at a temperature between 180° C. and 280° C., and preferably between 200° C. and 240° C.
[0019] The present invention provides metal-organic precursors that are dissolved in matched inert solvent. Such precursor solutions overcome the decomposition and solidification problems exhibited when using solid precursors directly, e.g. without solvents. Therefore, the solution-based precursors of the present invention represent a significant advance in the art. As discussed above, the solution-based precursors of the present invention are capable of producing high quality ALD film without self growth and solid residues. This is an improvement over the use of some oxygen containing Cp precursor that exhibit self growth. While the studies above concentrate on oxygen-free Cp precursors, the present invention is no so limited. Rather, the precursors of the present invention can have the general formula A x B y M(m) wherein M is a metal, m is the oxidation state of the metal M and can range from 0 to 7, A and B are the same or different (where x+y=m, if m≠0 and A and B are uni-negatively charged groups; otherwise x+y=1 to 8) and can be one of the following chemical classes: (1) cyclopentadienyl (Cp) and its derivatives (R1R2R3R4R5Cp; wherein R1, R2, R3, R4 and R5 are the same or different and can be hydrogen or alkyl [C n H 2n+1 , n=1−6]); (2) primary, secondary or tertiary alkyl groups (C n H 2n+1 , n=1−12); (3) cycloalkyl groups (C n R 2n−1 , n=3−12, wherein R is hydrogen or alkyl groups); (4) cycloalkyldienes (C n R 2n−4 , n=4−12, wherein R is hydrogen or alkyl groups); (5) benzene and its derivatives (R1R2R3R4R5R6C 6 ; wherein R1, R2, R3, R4, R5 and R6 are the same or different and can be hydrogen or alkyl [C n H 2n+1 , n=1−6]); (6) amides (R1R2N, wherein R1 and R2 are the same or different and can be hydrogen or alkyl [C n H 2n+1 , n=1−6]); or (7) bidentate ligands (R1E1=C(R3)−[C(R4)=C(R5)] n −E2R2; wherein E1 and E2 are the same or different and can be nitrogen, oxygen, phosphorus or sulfur; n=0−4; R1, R2, R3, R4 and R5 are the same or different and can be none, hydrogen, any alkyl or any aryl groups). Suitable solvents for the solid precursors according to the present invention have closely matched boiling points and can be alkanes, alkenes, alkynes, or aromatics. As noted above, the concentration of the solution precursors of the present invention is from 0.05M to 1.0M, preferably 0.1M.
[0020] The present invention makes it possible to use metal-organic precursor materials that can leave more than 5% solid residue, which could not previously have been used in vapor phase deposition processes because of the risk of decomposition and solidification. By using the precursors according to the solution-based chemistry of the present invention, it is possible to eliminate self-growth tendencies that have been observed when using neat metal-organic precursors.
[0021] The precursors of the present invention are useful for several applications. In particular, the precursors of the present invention may be used for forming high-k gate dielectric layers for Si, Ge, and C based group IV elemental semiconductors or for forming high-k gate dielectric layers for InGaAs, AlGaAs and other III-V high electron mobility semiconductors. In addition, the precursors of the present invention are useful for forming high-k capacitors for DRAM, flash, phase-change and resistive memory devices. The precursors of the present invention can also be used as metal-based catalysts for gas purification, organic synthesis, fuel cell membranes and chemical detectors, or as metal-based surfaces for electrode materials in fuel cells.
[0022] It will be understood that the embodiments described herein are merely exemplary and that one skilled in the art may make variations and modifications without departing from the spirit and scope of the present invention. All such variations and modifications are intended to be included within the scope of the invention as described above. Further, all embodiments disclosed are not necessarily in the alternative, as various embodiments of the invention may be combined to provide the desired result. | Solution-based precursors for use as starting materials in film deposition processes, such as atomic layer deposition, chemical vapor deposition and metalorganic chemical vapor deposition. The solution-based precursors allow for the use of otherwise solid precursors that would be unsuitable for vapor phase deposition processes because of their tendency to decompose and solidify during vaporization. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
This invention is a continuation-in-part of U.S. patent application Ser. No. 07/948,540, filed Sep. 22, 1992, titled "Treated Apatite Particles for Medical Diagnostic Imaging," which is continuation-in-part of U.S. patent application Ser. No. 07/784,325, filed Oct. 22, 1991,now abandoned, titled "Treated Apatite Particles for Medical Diagnostic Imaging," which applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
This invention relates to the preparation of calcium/oxyanion-containing particles for use in medical diagnostic imaging, such as magnetic resonance imaging ("MRI"), ultrasound, and X-ray. In particular, the present invention is directed to the use of a microfluidizer for the preparation of calcium/oxyanion-containing particles having a uniform small (<5 μm) size distribution. The present invention also includes the use of tangential flow filtration for particle purification.
The use of contrast agents in diagnostic medicine is rapidly growing. In X-ray diagnostics, for example, increased contrast of internal organs, such as the kidneys, the urinary tract, the digestive tract, the vascular system of the heart (angiography), etc., is obtained by administering a contrast agent which is substantially radiopaque. In conventional proton MRI diagnostics, increased contrast of internal organs and tissues may be obtained by administering compositions containing paramagnetic metal species which increase the relaxivity of surrounding protons. In ultrasound diagnostics, improved contrast is obtained by administering compositions having acoustic impedances different than that of blood and other tissues.
Often it is desirable to image or treat a specific organ or tissue. Effective organ- or tissue-specific diagnostic agents accumulate in the organ or tissue of interest. Copending patent application Ser. No. 07/948,540, filed Sept. 22, 1992, titled "Treated Apatite Particles for Medical Diagnostic Imaging," which is incorporated herein by reference, discloses the preparation and use of apatite particles for medical diagnostic imaging. This patent application also describes methods for preparing apatite particles which provide organ- or tissue-specific contrast. By carefully controlling the particle size and route of administration, organ specific imaging of the liver, spleen, gastrointestinal tract, or blood pool is obtained.
In general, the apatite particles are prepared by modifying conventional methods for preparing hydroxyapatite (sometimes referred to as "hydroxylapatite"). For example, stoichiometric hydroxyapatite, Ca 10 (OH) 2 (PO 4 ) 6 , is prepared by adding an ammonium phosphate solution to a solution of calcium/ammonium hydroxide. Useful apatite particles may also be prepared by replacing calcium with paramagnetic metal ions. Other apatite derivatives are prepared by replacing the OH -- with simple anions, including F -- , Br -- , I -- , or 1/2[CO 3 2- ].
Various techniques for controlling the particle size for certain calcium phosphate-containing compounds (apatites) are disclosed in copending application Ser. No. 07/948,540. For example, slower addition rates (introduction of the precipitating anion or cation), faster stirring, higher reaction temperatures, and lower concentrations generally result in smaller particles. In addition, sonication during precipitation, turbulent flow or impingement mixers, homogenization, and pH modification may be used to control particle size. Other means, such as computer controlled autoburets, peristaltic pumps, and syringes, may be used to control the release of precipitating ions to produce smaller particles.
Due to the small size and nature of apatite particles, they tend to aggregate. Particle aggregation may be inhibited by coating the particles with coating agents, while agglomerated particles may be disrupted by mechanical or chemical means and then coated with a coating agent having an affinity for the apatite.
One preferred method of obtaining small, uniformly sized, manganese-doped apatite particles is to dropwise add a degassed solution of (NH 4 ) 2 HPO 4 and NH 4 OH into a rapidly stirring degassed solution of Ca(NO 3 ) 2 ·4H 2 O and Mn(NO 3 ) 2 ·6H 2 O. The resulting apatite particles are then reacted with a solution of 1-hydroxyethane-1,1-diphosphonic acid (HEDP). The smaller particles are separated from larger particles by repeated centrifuging and collection of the supernatant. The particles are then washed to remove base and salts by centrifuging at a higher rpm, discarding the supernatant, resuspending the solid pellet in water, and recentrifuging.
Although the foregoing procedure produces small-sized apatite particles having good size distribution and good medical diagnostic imaging properties, the repeated centrifuging, decanting, and washing causes the process to be tedious and time-consuming. It, therefore, would be a significant advancement in the art to provide an improved method for rapidly preparing calcium/oxyanion-containing particles for medical diagnostic applications having a controlled particle size distribution and good yield.
Such methods for preparing calcium/oxyanion-containing particles are disclosed and claimed herein.
SUMMARY OF THE INVENTION
The present invention provides methods of preparing calcium/oxyanion-containing particles, including apatites and apatite precursors, using a microfluidizer. The particles thus prepared, are for use in medical diagnostic imaging, such as magnetic resonance imaging, X-ray, and ultrasound applications. The desired calcium/oxyanion-containing particles are synthesized, passed through a microfluidizer, and purified to remove excess base, salts, and other materials used to synthesize the particles. The microfluidizer causes two high pressure streams to interact at ultra high velocities in a precisely defined microchannel. Use of the microfluidizer results in significant reduction in the average particle size. Purifying the particles, preferably using tangential flow filtration, as well as coating the particles, improves particle stability.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides methods for preparing calcium/oxyanion-containing particles, including apatites and apatite precursors, especially hydroxyapatite, having uniform, small (<5 μm) particle size and uniform distribution through use of a microfluidizer.
As used herein, calcium/oxyanion-containing particles include calcium phosphate minerals, apatites, and apatite precursors of the general formula Ca n M m X r Y s , where M is a paramagnetic metal ion, radiopaque metal ion, radioactive metal ion, or stoichiometric mixture of metal ions, X is a simple anion, Y is an oxyanion including tetrahedral oxyanions, protonated or unprotonated, carbonate, or mixtures thereof, m is from 0 to 10, n is from 1 to 10, s is ≧1, and r is adjusted as needed to provide charge neutrality.
As used herein, apatite precursors include compounds within the scope of the above general formula having one or more amorphous phases which, when sintered, may become crystalline apatites.
Possible paramagnetic metal ions which can be used in the calcium/oxyanion-containing particles of the present invention include: chromium(III), manganese(II), iron(II), iron (III), praseodymium (III), neodymium (III), samarium(III), ytterbium(III), gadolinium(III), terbium(III), dysprosium(III), holmium(III), erbium(III), or mixtures of these with each other or with alkali or alkaline earth metals.
Certain radiopaque heavy metals, such as bismuth, tungsten, tantalum, hafnium, lanthanum and the lanthanides, barium, molybdenum, niobium, zirconium, and strontium may also be incorporated into particles to provide X-ray contrast.
Typical simple anions which can be used in the calcium/oxyanion-containing particles of the present invention include: OH -- , F -- , Br -- I -- , 1/2]CO 3 2- ], or mixtures thereof. The tetrahedral oxyanions used in the present invention may optionally include radiopaque metals or radioactive metals. Suitable tetrahedral oxyanions are nonoxidizing and stable to hydrolysis. Examples of suitable tetrahedral oxyanions for use in the present invention include: PO 4 3- , AsO 4 3- , WO 4 2- , MoO 4 2- , VO 4 3- , SiO 4 4- , and GeO 4 4- , and when stable, protonated forms of these. Phosphate is a currently preferred tetrahedral oxyanion.
By controlling the particle size, organ specific imaging or therapy of the liver or gastrointestinal tract is obtained. When apatite particles having a size in the range from about 5 nm to about 5 μm are injected into the vascular system, the particles collect in the liver or spleen (the RES system) because a normal function of these organs is to purify the blood of foreign particles. Once the particles have collected in the liver or spleen, these organs may be imaged by the desired medical diagnostic imaging technique.
Depending on the diagnostic imaging technique, calcium/oxyanion containing particles are treated to be paramagnetic, radiopaque, or echogenic. For example, paramagnetic metal species may be incorporated into the particles to improve magnetic resonance contrast, and radiopaque species may be incorporated to provide X-ray contrast. Particle density, and corresponding echogenic characteristics, can be controlled to impart low or high acoustic impedance relative to blood. The calcium/oxyanion-containing particles may also be fluorinated to form stable, nontoxic compositions useful for 19 F imaging. The presence of a paramagnetic metal species in these particles may reduce 19 F and proton relaxivity, thereby enhancing MRI, MRS, or MRSI.
Hydroxyapatite doped with a paramagnetic metal can be prepared by mixing a basic (pH 10-12) phosphate solution with a calcium/paramagnetic metal solution at native pH. It has been found that the paramagnetic ions incorporated into the apatite particle tend to oxidize during particle synthesis. To prevent metal oxidation the amount of oxygen in the aqueous reactant solutions is minimized. Oxygen minimization is obtained by synthesis at high temperature, such as 100° C. or by degassing the aqueous reactant solutions with an inert gas such as argon, nitrogen, or helium.
Antioxidants, such as gentisic acid and ascorbic acid, added during or after apatite particle synthesis may also be used to prevent metal ion oxidation. Reducing agents, such as NaBH 4 , have been found to reduce metal ions that are unintentionally oxidized during apatite particle synthesis.
Paramagnetic particles may also be prepared by adsorbing paramagnetic metal ions onto the particle. For example, manganese can be adsorbed to hydroxyapatite particles by taking a slurry of hydroxyapatite and adding Mn(NO 3 ) 2 with stirring. Applying energy, such as ultrasonic power or heat, to the resulting mixture may also facilitate the reaction. The resulting mixture can be separated by either centrifugation and decantation or by filtration. Any excess manganese may be removed by washing with large amounts of water. The manganese adsorbed particles can then be stabilized against oxidation and particle agglomeration with a suitable coating agent. The same procedure may be used with other paramagnetic cations. The amount of manganese adsorbed onto the particle surface, as a percentage of the total calcium in the particle, is in the range from about 0.1% to about 50%. Such particles exhibit very high relaxivities and rapid liver enhancement in magnetic resonance imaging studies.
Particle Size Reduction and Production of Particles of Uniform Size Using a Microfluidizer
It has been found that passing calcium/oxyanion-containing particles, including apatites and apatite precursors, through a microfluidizer results in dramatic particle size reduction. A microfluidizer, such as those produced by Microfluidics Corporation, Newton, Mass., causes two high pressure fluid streams to interact at ultra high velocity. It is postulated that shear, impact and cavitation forces act on the fluid streams to achieve submicron particle reduction with uniform distribution. Fluid pressures typically range from 2000 psi to 30,000 psi with some production size microfluidizers capable of handling pressures up to 40,000 psi.
Experimental results suggest that particle size reduction using a microfluidizer can be obtained from apatite particles regardless of whether the particles are first stabilized with a coating agent or purified from the base, salts, and other compounds used to prepare the particles. The particles may be purified or unpurified, coated or uncoated when passed through the microfluidizer. However, it appears that the microfluidized apatite particles show better stability with removal of the base, salts, and other compounds in the reaction mixture. The particles tend to become larger when stored in the basic reaction solution, but growth of purified particles is either stopped or inhibited by purification of the particles from the mixture. Particle purification can be obtained by processes such as repeated centrifuging and decanting, passing through a desalting column, and filtration, preferably tangential flow filtration or ultrafiltration.
Particle Coating
Stabilized calcium/oxyanion-containing particles, including apatites and apatite precursors, are desirable for in vivo use as medical diagnostic imaging agents. Such particles tend to aggregate. Although the reasons calcium/oxyanion-containing particles aggregate is not fully understood, it has been found that several different coating agents are able to inhibit particle aggregation. For example, these particles may be stabilized by treatment with coating agents such as di- and polyphosphonate-containing compounds or their salts, such as 1-hydroxyethane-1,1-diphosphonate (HEDP), pyrophosphate, aminophosphonates; carboxylates and polycarboxylate-containing compounds such as oxalates and citrates; alcohols and polyalcohol-containing compounds; compounds containing one or more phosphate, sulfate, or sulfonate moiety; and biomolecules such as peptides, proteins, antibodies, and lipids all have been shown to inhibit particle aggregation. Such coating agents stabilize the small particles by reducing further particle growth and promoting particle suspension.
When used in magnetic resonance imaging, particle relaxivity is enhanced by allowing more water accessible to the particle surface. By limiting particle size and increasing the available surface area, relaxivity may be improved.
In addition to the coating agents identified above, conventional particle coating techniques may also be used in the manufacturing processes of the present invention. Typical coating techniques are identified in International Publication Numbers WO 85/02772, WO 91/02811, and European Publication Number EP 0343934, which are incorporated by reference.
For instance, agglomerated particles may be disrupted by mechanical or chemical means and then coated with polymers such as carbohydrates, proteins, and synthetic polymers. Dextran having a molecular weight in the range from about 10,000 to about 40,000 is one currently preferred coating material. Albumin and surfactants, such as tween 80, have also been used to reduce particle aggregation. One common characteristic of useful apatite coating agents is their ability to modify the particle surface charge, or zeta potential.
It will be appreciated that the calcium phosphate-containing particles within the scope of the present invention may be coated before, during, or after passage through the microfluidizer. When coated during passage through the microfluidizer, one fluid stream is the coating agent, while the other fluid stream is the particulate stream.
The currently preferred mechanical means for reducing particle size is microfluidization, but other means such as heating, sonication, other forms of particle energization, such as irradiation, and chemical means, such as pH modification or combinations of these types of treatment, such as pH modification combined with sonication may be used.
Diagnostic Pharmaceutical Formulations
The calcium/oxyanion-containing particles of this invention may be formulated into diagnostic compositions for parenteral administration. For example, parenteral formulations advantageously contain a sterile aqueous solution or suspension of treated apatite or apatite precursor particles according to this invention. Various techniques for preparing suitable pharmaceutical solutions and suspensions are known in the art. Such solutions also may contain pharmaceutically acceptable buffers and, optionally, electrolytes such as sodium chloride. Parenteral compositions may be injected directly or mixed with a large volume parenteral composition for systemic administration.
The diagnostic compositions of this invention are used in a conventional manner in medical diagnostic imaging procedures such as magnetic resonance, X-ray, and ultrasound imaging. The diagnostic compositions are administered in a sufficient amount to provide adequate visualization, to a warm-blooded animal either systemically or locally to an organ or tissues to be imaged, then the animal is subjected to the medical diagnostic procedure. Such doses may vary widely, depending upon the diagnostic technique employed as well as the organ to be imaged.
The following examples are offered to further illustrate the present invention. These examples are intended to be purely exemplary and should not be viewed as a limitation on any claimed embodiment.
EXAMPLE 1
Preparation of Hydroxyapatite Particles Doped with Mn, Treated with HEDP, Purified and Passed through Microfluidizer
Manganese containing hydroxyapatite particles were prepared by the following general procedure. A procedure is described for particles containing 10% Mn (compared to the total metal content) but other percentages are also applicable.
Into a 1 L erlenmeyer flask were placed 10.5 g of (NH 4 ) 2 HPO 4 , 100 mL of concentrated NH 4 OH and 350 mL of D.I. water. The mixture was stirred for two hours with a continuous heavy argon flow (degassing). In a separate 1 L erlenmeyer flask were placed 28.9 g of Ca(NO 3 ) 2 ·4H 2 O and 2.4 g of Mn(NO 3 ) 2 ·6H 2 O in 400 mL of D.I. water. The metal nitrate solution was degassed with argon for 2 hours. The phosphate solution was then added dropwise to the rapidly stirred metal nitrate mixture over two hours with a peristaltic pump. A continuous argon flow was maintained throughout the course of the reaction. The reaction mixture was stirred for an additional two hours after the addition was complete. A solution of 8.3 mL of a 60% solution HEDP (acid form) in 25 mL of D.I. water was degassed for 30 minutes then added in one aliquot to the hydroxyapatite mixture. The resulting slurry was stirred for 15 minutes.
The entire reaction mixture was centrifuged at one time at 2400 rpm for 15 minutes. The supernatant was discarded and the solid residue in each tube resuspended in water. The slurry was re-centrifuged at 2400 rpm and the milky supernatant was collected. The solid was resuspended twice more and centrifuged at 2400 rpm. The three washes were combined and centrifuged at 7000 rpm for 30 minutes. The resulting solid pellet was separated from the supernarant by decantation, and the pellet was washed (D.I. H 2 O) and centrifuged three times, and the supernatants were discarded. After washing, the solid pellet was suspended in 30 mL of D.I. H 2 O.
The preparation was stored at room temperature for one month. The particle size was analyzed and found to be 280 nm (2.9 chi squared, 0.31 coefficient of variance). The particulate suspension was passed through a microfluidizer at approximately 5000 psi. After one pass through the microfluidizer, the particle size was reduced to 125 nm (0.43 chi squared, 0.35 coefficient of variance). After another pass through the microfluidizer at a pressure of approximately 10,000 psi, the size did not change significantly, 144 nm (0.20 chi squared, 0.28 coefficient of variance). At three hours and 36 hours after passing through the microfluidizer, the particle size remained essentially constant at 159 nm and 148 nm, respectively.
EXAMPLE 2
Preparation of Hydroxyapatite Particles Doped with Mn and Treated with HEDP and Passed through Microfluidizer Unpurified
Manganese containing hydroxyapatite particles were prepared according to the procedure of Example 1, except that the particles were not purified by centrifuging, decanting, and washing, but left in the base and salt solution. The particulate suspension (average size >1 μm, chi squared >20) was passed through a microfluidizer at approximately 5000 psi. After one pass through the microfluidizer, the particle size was 87 nm (2.3 chi squared, 0.41 coefficient of variance). After five passes through the microfluidizer at pressures from 5000 psi to 7000 psi, the particle size was 89 nm (0.88 chi squared, 0.37 coefficient of variance).
The resulting particles were too small to pellet at 2400 rpm and were left in the base and salts. There was no indication that multiple passes through the microfluidizer made smaller particles, but it appears the uniformity was increased. Twenty hours after passing through the microfluidizer the particle size has increased to 713 nm (21.1 chi squared, 0.53 coefficient of variance). Although the chi squared was large, indicating a poor fit to a gaussian distribution, the coefficient of variance was small with 99% of the particles less than 2 μm and 75% less than 825 nm. The relaxivity (R 1 ) of these particles 2 hours after formation was approximately 22 mM -1 s -1 .
EXAMPLE 3
Preparation of Hydroxyapatite Particles Doped with Mn and Passed through Microfluidizer Unpurified with a Simultaneous Coaxial Stream of HEDP
Manganese containing hydroxyapatite particles were prepared according to the procedure of Example 1, except that the particles were not coated with HEDP and were not purified by centrifuging, decanting, and washing, but left in the base and salt solution. The particulate suspension was passed as one stream into a microfluidizer. The other microfluidizer stream consisted of a HEDP solution prepared according to the procedure of Example 1. The two streams passed through the microfluidizer at a pressure of 10,000 psi. The resulting particulate suspension had a particle size of 70 nm (2.4 chi squared, 0.42 coefficient of variance). The particles were not purified from base and salts. Two hours after formation the particle size was 87 nm (1.8 chi squared, 0.41 coefficient of variance). Thirty-six hours after formation the particle size was 903 nm (0.84 chi squared, 0.45 coefficient of variance) indicating the particles had grown uniformly to a large size. The relaxivity (R 1 ) of these particles was 24 mM -1 s -1 .
EXAMPLE 4
Preparation of Hydroxyapatite Particles Doped with Mn and Passed through Microfluidizer Unpurified into Neutral HEDP Solution
Manganese containing hydroxyapatite particles were prepared according to the procedure of Example 1, except that the particles were not coated with HEDP and were not purified by centrifuging, decanting, and washing, but left in the base and salt solution. The particulate suspension was passed through a microfluidizer at 10,000 psi and into a beaker of neutral HEDP. The neutral HEDP solution was prepared from 8.3 mL of a 60% solution HEDP (neutral form) in 25 mL of D.I. water.
The resulting particulate solution had an average particle size of 1333 nm (7.3 chi squared, 0.40 coefficient of variance). Two hours after formation, the particle size was 884 nm (8.3 chi squared, 0.46 coefficient of variance). The results suggest that the use of acidic HEDP is useful in the formation of small particles and the neutral form of HEDP may be used when larger particles are desired.
Examples 1-4 indicate that the particle size of manganese doped hydroxyapatite may be substantially reduced by the shear, impact and cavitation forces present within the microfluidizer.
EXAMPLE 5
Preparation of Hydroxyapatite Particles Doped with Mn, Washed, Coated with Aminotri(methylene Phosphonic acid) (ATMP), and Passed through Microfluidizer
Manganese containing hydroxyapatite particles were prepared according to the procedure of Example 1, except that the particles were not coated with HEDP and the particles were washed free of base and salts by centrifuging three times at 2400 rpm. Degassed water was used to wash the pelleted particles following centrifuging. An ATMP solution was prepared by mixing 0.0027 moles or 1.6 mL of a 50% aqueous solution with 25 mL D.I. H 2 O and degassing for 30 minutes under argon. The ATMP solution was added dropwise to the washed particles resulting in a "white" slurry. The slurry was passed through a microfluidizer at 10,000 psi. After passing through the microfluidizer, the particles had an estimated size of 84 nm (1.3 chi squared, 0.52 coefficient of variance). There was some oxidation of manganese with time as evident from a brown appearance in the particles. After six days there were two populations of particles, 46 nm and >2 μm. The percentages of each component could not be determined due to the limits of the particle analyzer and settling of the larger particles.
EXAMPLE 6
Preparation of Hydroxyapatite Particles Doped with Mn, Coated with HEDP, Passed through Microfluidizer, and Purified
Manganese containing hydroxyapatite particles were prepared according to the procedure of Example 1, except that the particles were not coated with HEDP and were not purifiedby centrifuging, decanting, and washing, but left in the base and salt solution. An HEDP solution prepared according to the procedure of Example 1 was added dropwise to the particles. The particle size before passing through a microfluidizer was 1498 nm (13.4 chi squared, 0.93 coefficient of variance). After passing the particulate suspension through the microfluidizer at 10,000 psi the particle size was 62 nm (0.27 chi squared, 0.47 coefficient of variance). About 2-3 hours after microfluidization, one half of the particulate suspension was passed through a Sephadex 10(S-10) desairing column to remove base, salts, and excess ligand. The remaining particulate suspension was retained as a control. Following S-10 purification, the particle size was 78 nm (3.3 chi squared, 0.44 coefficient of variance). Six days later, the particle size of the S-10 purified sample was 100 nm (0.40 chi squared, 0.38 coefficient of variance). After 12 days, the size of the particles that were passed through the microfluidizer but were not purified and stored in the base solution increased to 744 nm (4.22 chi squared, 0.57 coefficient of variance). In contrast, after 12 days the S-10 purified fraction had a particle size of 77 nm (0.65 chi squared, 0.44 coefficient of variance).
EXAMPLE 7
Preparation of Hydroxyapatite Particles Doped with Mn, Coated with ATMP, Passed through Microfluidizer, and Purified
Manganese containing hydroxyapatite particles were prepared according to the procedure of Example 1, except that the particles were not coated with HEDP and were not purified by centrifuging, decanting, and washing, but left in the base and salt solution. An ATMP solution was prepared by mixing 0.0027 moles or 1.6 mL of a 50% aqueous solution with 25 mL D.I. H 2 O and degassing for 30 minutes under argon. The ATMP solution was added dropwise to the particles. The particle size before passing through a microfluidizer was 1465 nm and difficult to analyze due to settling. After passing the particulate suspension through the microfluidizer at 10,000 psi the particle size was 85 nm (0.58 chi squared, 0.41 coefficient of variance). The particulate suspension was divided into two parts. One part was passed through a Sephadex 10(S-10) desalting column to remove base, salts, and excess ligand. The remaining part of the particulate suspension was retained as a control. Following S-10 purification, the particle size was 67 nm (0.25 chi squared, 0.44 coefficient of variance). Six days later, the particle size of the S-10 purified sample was 131 nm (0.60 chi squared, 0.39 coefficient of variance). There were three populations in the S-10 fraction: 66 nm (45%), 193 nm (38%) and 665 nm (16%). After 12 days, the fraction that was stored in base solution had a particle size of 515 nm (0.50 chi squared, 0.47 coefficient of variance).
From the foregoing Examples, it appears the apatite particles are stabilized better with removal of the base, salts, and excess phosphonate. The particles tend to grow at a fast rate when stored in the reaction solution, but growth of purified particles is either stopped or inhibited. There seems to be a preference for the formation of smaller particles when the microfluidizer experiments are carried out in the base rather than the washed particles.
EXAMPLE 8
Preparation of Hydroxyapatite Particles Doped with Mn, Coated with HEDP, Passed through Microfluidizer, and Purified by Tangential Flow Filtration
Manganese containing hydroxyapatite particles were prepared by the following general procedure. A procedure is described for particles containing 10% Mn but other percentages are also applicable.
Into a 1 L erlenmeyer flask were placed 10.55 g of (NH 4 ) 2 HPO 4 , 100 mL of concentrated NH 4 OH and 300 mL of D.I. water. The mixture was stirred for one hour with a continuous heavy argon flow (degassing). In a separate 1 L erlenmeyer flask were placed 28.9 g of Ca(NO 3 ) 2 ·4H 2 O and 2.42 g (0.01355 moles) of Mn(NO 3 ) 2 ·6H 2 O in 200 mL of D.I. water. The metal nitrate solution was degassed with argon for one hour. The phosphate solution was then added dropwise to the rapidly stirred metal nitrate mixture over 15 minutes with a peristaltic pump. A continuous argon flow was maintained throughout the course of the reaction. The reaction mixture was stirred for an additional one hour after the addition was complete. A solution of 5 g or 8.3 mL of a 60% solution HEDP (acid form) in 20 mL of D.I. water was degassed for 30 minutes then added dropwise to the hydroxyapatite mixture. The resulting slurry was stirred for 1.5 hours.
Two thirds of the reaction mixture was passed through a microfluidizer at 10,000 psi. The particle size before passing through a microfluidizer was 800 nm (27 chi squared, 0.92 coefficient of variance). After passing the particulate suspension through the microfluidizer, the particle size was 53 nm (2.2 chi squared, 0.48 coefficient of variance). The particulate suspension was then purified to remove base, salts, and excess ligand by passing it through a tangential flow filtration (sometimes referred to as "ultrafiltration") system. The tangential flow filtration system was obtained from Koch Membrane Systems, Inc., Wilmington, Mass. After each filtration pass, the osmolality was measured. A total of 10 filtration passes were made followed by a 3-fold concentration step. Following filtration, the particle size was 67 nm (0.43 chi squared, 0.44 coefficient of variance). After 12 days, the size of the particles that were passed through the microfluidizer but were not purified and stored in the base solution increased to 744 nm (4.22 chi squared, 0.57 coefficient of variance). In contrast, after 12 days the filtered fraction had a particle size of 82 nm (2.7 chi squared, 0.41 coefficient of variance).
EXAMPLE 9
Preparation at 100° C. of Hydroxyapatite Particles Modified by Surface-Adsorbed Mn, Coating with HEDP, Passage through Microfluidizer, and Purification
Calcium hydroxyapatite particles are prepared by the following procedure:
A solution containing 6.5 g of (NH 4 ) 2 HPO 4 in 120 mL of D.I. water is treated with 60 mL of concentrated NH 4 OH followed by 90 mL of D.I. water. The resulting solution is stirred for 3 hours at room temperature.
Into a 3-neck 1 L round bottom flask equipped with a water cooled and low temperature condenser sequence (dry ice/isopropanol), mechanical stirrer and rubber septum are placed 19.4 g of Ca(NO 3 ) 2 ·4H 2 O in 468 mL of D.I. water. The solution is heated to reflux. The phosphate mixture is added to the rapidly stirred calcium nitrate solution dropwise with a peristaltic pump over one hour. The heat is removed when the addition is complete and the reaction mixture is cooled to room temperature. The hydroxylapatite slurry is stirred overnight at room temperature.
The pH of the reaction mixture is decreased from 9.53 to 8.50 with 169 ml of 1N HCl. Manganese nitrate, Mn(NO 3 ) 2 ·6H 2 O (2.10 g) is added to the hydroxyapatite mixture and stirred for 1 hour and 15 minutes. The color of the slurry is pale tan. The mixture is passed through a tangential flow filter to remove excess manganese nitrate from the apatite particles. The particulate slurry is then treated with 0.54M HEDP (Ca/HEDP mole ratio=1.2) and stirred for 1.5 hours. The color of the mixture is pale pink/purple.
The HEDP treated hydroxyapatite particulate suspension is passed through a microfluidizer at a pressure of 5000 psi. The particulate suspension is then purified to remove base, salts, and excess ligand by passing it through a tangential flow filtration system.
EXAMPLE 10
Preparation of Mn-Doped Hydroxyapatite Particles Having a Functionalized Coating Agent, Passage Through Microfluidizer and Purification by Filtration
This example describes the general preparation of hydroxyapatite particles having a functionalized coating agent where the functionalized coating agent is defined as one with the ability to bind tightly to the particles and contains a pendant group to which other organic biomolecules or organic may be attached. The particles are prepared by adding 0.1 to 100 mole % of an appropriate coating agent to a slurry of Mn(II) substituted hydroxyapatite with 0.1 to 100 mole % Mn based on the Ca used in the reaction. The mixture is stirred from 1 to 360 minutes at temperatures in the range from 4° C. to 100° C. The particulate suspension is passed through a microfluidizer at a pressure in the range from 2000 to 20,000 psi, and the solid separated from the supernatant and purified from excess ions and coating agent by tangential flow filtration. The solid may be treated with a metal salt (0.01 to 10 mole % based on the total metal in the preparation). This is especially appropriate if the coating agent contains a pendant chelating group designed to capture and hold tightly the metal when subjected to in vitro and/or in vivo solutions. The resultant solid is purified to remove loosely attached coating agent or free metal/coating agent complex by tangential flow filtration.
EXAMPLE 11
Preparation of Hydroxyapatite Particles by Treating with Diethylenetriamine-penta(methylenephosphonic acid), Surface Adsorbing Mn, Passing through Microfluidizer, and Purification
Calcium hydroxyapatite is prepared by the following procedure and treated with the polyphosphonate, diethylenetriaminepenta(methylenephosphonic acid) (abbreviated DETAPMDP) having the following formula: ##STR1##
A basic ammonium phosphate solution is prepared using 6.34 g of (NH 4 ) 2 HPO 4 in 120 mL of D.I. water. Concentrated ammonium hydroxide (60 mL) is added followed by 90 ml of D.I. water. The mixture is stirred for 4 hours at room temperature.
A solution of 19.0 g of Ca(NO 3 ) 2 ·4H 2 O in 468 mL of D.I. water is placed in a 3-neck 1 L round bottom flask. The reaction setup includes a mechanical stirrer, water cooled and low temperature (dry ice/isopropanol) condenser arrangement, and a rubber septum. The solution is heated to reflux with rapid stirring. The basic phosphate solution is added dropwise with a peristaltic pump over one hour. The heat is removed after the addition is complete and the reaction mixture stirred overnight at room temperature.
The hydroxyapatite slurry is treated with a solution of DETAPMDP (Ca/DETAPMDP mole ratio=1.1, pH of DETAPMDP 6.3) and stirred at room temperature for 2.5 hours. The phosphonate treated mixture is then reacted with Mn(NO 3 ) 2 ·6H 2 O (Ca/Mn mole ratio=2.3) and stirred for an additional 3.5 hours. The reaction mixture is passed through a microfluidizer at a pressure of 5000 psi and purified by tangential flow filtration.
From the foregoing, it will be appreciated that the present invention provides an improved method for preparing solid calcium phosphate-containing particles for medical diagnostic applications having a controlled particle size distribution and good yield.
The invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. | Methods of preparing solid apatite particles using a microfluidizer, for use in medical diagnostic imaging such as magnetic resonance imaging, X-ray, and ultrasound. The desired apatite particles are synthesized, passed through a microfluidizer, and purified to remove excess base, salts, and other materials used to synthesize the particles. The microfluidizer causes two high pressure streams to interact at ultra high velocities in a precisely defined microchannel. Microfluidization of preparations causes small (<5 μm) and uniform particles to be formed. Coating and purifying (especially by tangential flow filtration) the particles improves particle stability. | 0 |
The present invention relates generally to a method for improving the recovery of bitumen in an oil sand extraction process by recycling a portion of primary bitumen froth produced in a primary separation vessel to a location upstream of the primary separation vessel. In one embodiment, the portion of primary bitumen froth is deaerated prior to upstream recycling.
BACKGROUND OF THE INVENTION
Oil sand, such as is mined in the Fort McMurray region of Alberta, generally comprises water-wet sand grains held together by a matrix of viscous bitumen. It lends itself to liberation of the sand grains from the bitumen by mixing or slurrying the oil sand in water, allowing the bitumen to move to the aqueous phase.
For many years, the bitumen in the McMurray sand has been commercially removed from oil sand using what is commonly referred to in the industry as the “hot water process”, whereby as-mined oil sand is mixed in a rotating tumbler for a prescribed retention time (generally in the range of 2 to 4 minutes) with hot water (approximately 80-90° C.), steam, caustic (e.g., sodium hydroxide) and naturally entrained air to yield a slurry that has a temperature typically around 80° C. The bitumen matrix is heated and becomes less viscous. Chunks of oil sand are ablated or disintegrated. The released sand grains and separated bitumen flecks are dispersed in the water. To some extent bitumen flecks coalesce and grow in size. They may contact air bubbles and coat them to become aerated bitumen. The term used to describe this overall process in the tumbler is “conditioning”. The slurry is then diluted with additional hot water to produce a diluted slurry having a temperature of about 65° C. to about 80° C. The diluted slurry is introduced into a large, open-topped, conical-bottomed, cylindrical vessel commonly termed a primary separation vessel (PSV) where the more buoyant aerated bitumen rises to the surface and forms a bitumen froth layer. This froth layer overflows the top lip of the PSV and is received in a launder extending around the PSV's rim. The product is commonly called “primary bitumen froth” and typically has a temperature of about 65° C. to about 75° C.
In the early 1990s, there was a major innovation in the oil sand industry, which is commonly referred to as “pipeline conditioning”. This innovation is disclosed in Canadian Patent No. 2,029,795 and U.S. Pat. No. 5,264,118. As-mined oil sand is mixed at the mine site (for example, in a cyclofeeder) with hot water, air and NaOH to produce a slurry. The slurry is pumped through a pipeline at least about 2.5 kilometres in length and is fed directly to a conventional gravity separation vessel such as a PSV. In the course of being pumped through the pipeline, sufficient coalescence and aeration of bitumen occurs so that, when subsequently retained in the vessel under quiescent conditions, a desirable amount of the bitumen floats, forms froth, and is recovered.
In the late 1990s a cold dense slurrying process for extracting bitumen from oil sand was developed, which is disclosed in Canadian patent No. 2,217,623 and U.S. Pat. No. 6,007,708. This process is commonly referred to as the “low energy extraction process” or the “LEE process” and generally comprises mixing as-mined oil sand with water in predetermined proportions near the mine site to produce a slurry containing entrained air and having a controlled density in the range of 1.4 to 1.65 g/cc and preferably a temperature in the range 20-40° C.; pumping the slurry through a pipeline having a plurality of pumps spaced along its length, preferably adding air to the slurry as it moves through the pipeline, to condition the slurry; diluting the slurry with flood water; and introducing the diluted slurry into a conventional gravity separation vessel such as a PSV to float the aerated bitumen. The froth is maintained at a temperature of at least 35° C. in the PSV by use of a warm water underwash, thereby assisting in removing the froth from the PSV and satisfying downstream froth temperature needs. A middlings layer and tailings layer are also formed in the PSV. A stream of middlings may be continuously withdrawn and further bitumen recovered in a secondary recovery circuit, for example, mechanical flotation cells. The secondary bitumen froth so produced may either be combined with the primary bitumen froth or recycled and added to the fresh slurry being introduced to the primary separation to increase bitumen recovery as primary froth, as described in U.S. Pat. No. 4,776,949.
SUMMARY OF THE INVENTION
It was surprisingly discovered that recycling a portion of the primary bitumen froth produced in a conventional gravity separation vessel such as a PSV to a location upstream of the vessel resulted in greater overall bitumen recovery and, more particularly, better recovery of bitumen in the primary froth and higher quality primary froth.
Thus, in one aspect of the present application, a process is provided for extracting bitumen from oil sand, comprising:
mixing oil sand with process water to produce an oil sand slurry containing bitumen, sand, water and entrained air; conditioning the oil sand slurry; optionally flooding the conditioned oil sand slurry with flood water to dilute the slurry if required; introducing the slurry into a primary separation vessel wherein separate layers of primary bitumen froth, middlings and sand tailings are formed; removing a portion of the primary bitumen froth from the primary separation vessel and recycling the portion of primary bitumen froth to that step of the process upstream of the primary separation vessel to join and mix with the feed stream moving to the primary separation vessel; and thereafter retaining said feed stream in said primary separation vessel to produce primary bitumen froth.
In one embodiment, the process further comprises deaerating the portion of primary bitumen froth removed from the primary separation vessel prior to upstream recycling.
By “conditioning” is meant digestion of oil sand lumps, liberation of bitumen from sand-fines-bitumen matrix, coalescence of liberated bitumen flecks into larger bitumen droplets and aeration of bitumen droplets. It is understood that such conditioning can occur by agitating the oil sand slurry in a conventional rotating tumbler or agitation tank for a sufficient period of time or by preparing the oil sand slurry in a slurry preparation unit and then pumping the oil sand slurry through a pipeline of sufficient length (e.g., typically greater than about 2.5 km).
By “deaerating” is meant removing a portion of the air present in the primary bitumen froth by any means known in the art, for example, using deaerator columns or other mechanical deaeration processes and/or heating deaeration processes, to give deaerated primary bitumen froth generally having an air content of less than about 20 volume %.
It is understood the quality of mined oil sand varies greatly in both the bitumen content and the fines content (solids having a size less about 44 μm). For example, a “low grade” oil sand typically will contain between about 6 to 10 wt. % bitumen and greater than about 25 wt. % fines. An “average grade” oil sand will typically contain at least 10 wt. % bitumen to about 12.0 wt. % bitumen with about 15 to 25 wt. % fines and a “high grade” oil sand will typically contain greater than 12.5 wt. % bitumen with less than 15 wt. % fines. The grade of oil sand used in extraction processes has very significant effects on the completeness of bitumen recovery in the PSV and the quality of the bitumen froth.
The temperature of the water used in the present invention for forming oil sand slurry can range from anywhere between about 20° C. (as used in the LEE process) to about 95° C. (as used in the hot water process). It was discovered that improvement in bitumen recovery by bitumen froth recycling was greatest when processing low to average grade oil sand.
In one embodiment, the oil sand slurry is predominantly conditioned in a conditioning pipeline and the portion of the primary bitumen froth from the PSV or deaerated primary bitumen froth is recycled to a mix tank or pump box located upstream of the conditioning pipeline and mixed with the oil sand slurry prior to pipeline conditioning. In another embodiment, the portion of primary bitumen froth from the PSV or deaerated primary bitumen froth can be injected into the conditioning pipeline at one or more points along the conditioning pipeline. In another embodiment, the portion of primary bitumen froth from the PSV or deaerated primary bitumen froth is recycled upstream of the primary separation vessel but downstream of the conditioning pipeline. In another embodiment, the portion of primary bitumen froth from the PSV or deaerated primary bitumen froth is recycled to the slurry preparation unit where the oil sand is first mixed with water to form the oil sand slurry. In one embodiment, where both oil sand and water mixing and slurry conditioning takes place in the slurry preparation unit itself, as is the case when using a rotating tumbler during the hot water extraction process, the portion of primary bitumen froth from the PSV or deaerated primary bitumen froth is added directly to the rotating tumbler.
Flood water may be added after slurry preparation and conditioning if the oil sand slurry is too dense, meaning it is substantially greater than 1.5 g/cc, to give a slurry having a density of about 1.4 g/cc to about 1.5 g/cc.
In one embodiment, the portion of primary bitumen froth recycled either directly from the PSV or after deaeration is at least between about 10% to about 50% of the froth produced in the primary separation vessel.
Other features will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific embodiments, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a is a block diagram setting forth the process in accordance with one aspect of the invention where primary bitumen froth is recycled upstream of the gravity separation step.
FIG. 1 b is a block diagram setting forth the process in accordance with one aspect of the invention where deaerated primary bitumen froth is recycled upstream of the gravity separation step.
FIG. 2 is a schematic of an industrial scale system for practicing the process.
FIGS. 3 a and 3 b are schematics of the pilot plant used in connection with the development of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention is exemplified by the following description and examples.
FIG. 1 a is a block diagram setting forth the process in accordance with one aspect of the invention. Mined oil sand is mixed with process water ranging in temperature from anywhere from about 95° C. to about 20° C., as is known in the art. Optionally, NaOH (caustic) may be added to the process water. The oil sand and process water is mixed in a slurry preparation system to produce oil sand slurry. Oil sand slurry is then conditioned, for example, by pumping it through a pipeline of sufficient length, generally 3 km or longer. The oil sand slurry is generally first contained in a mixing or pump box prior to being pumped through the conditioning pipeline.
The now conditioned oil sand slurry may be further diluted with flood water, if needed, to ensure the proper density of the slurry, e.g., approximately 1.4 g/cc to 1.5 g/cc, and, optionally, further aerated, prior to being fed into a quiescent gravity separation vessel commonly referred to in the industry as a primary separation vessel. In the primary separation vessel, separate layers of primary bitumen froth, middlings and sand tailings are formed.
A portion of the primary bitumen froth produced in the primary separation vessel, said portion in one embodiment ranging anywhere from about 10% to about 50%, is continuously removed and may be recycled upstream of the primary separation vessel, for example, to be mixed with the oil sand slurry prior to pipeline conditioning (bitumen froth stream 200 ). The portion of primary bitumen froth can be added, for example, to a pump box used to feed the oil sand slurry into the conditioning pipeline. It is understood, however, less than 10% of the primary froth can be recycled with less pronounced improvement in overall bitumen recovery. Further, it is understood that greater than 50% of the primary froth can be recycled, however, froth quality may start to decrease.
In another embodiment, the portion of primary bitumen froth can be added at the mixing step (bitumen froth stream 100 ), for example, to a slurry preparation unit such as a mixer circuit in the form of a vertically oriented stack of components, which functions to slurry oil sand with water in preparation for pumping through a conditioning pipeline, as disclosed in Canadian Patent No. 2,195,604. In another embodiment, the oil sand slurry preparation unit may both prepare the oil sand slurry and condition the slurry at the same time. For example, a rotary tumbler could be used as described in U.S. Pat. No. 4,776,949, which tumbler is generally used during the hot water process, and in this case oil sand slurry conditioning may take place entirely in the rotary tumbler so that pipeline conditioning is not needed. In this embodiment, the portion of primary bitumen froth can be added directly to the rotary tumbler (bitumen froth stream 100 ).
In another embodiment, the portion of primary bitumen froth can be added after the conditioning step but prior to the gravity separation step (bitumen froth stream 300 ). In this embodiment, the portion of primary bitumen froth can be added either before or after the addition of flood water and/or air.
In another aspect of the invention, which is shown in block diagram FIG. 1 b , the primary bitumen froth (or a portion thereof) is first deaerated in a deaerator as known in the art prior to being recycled upstream of the primary gravity separation step. One example of a deaeration process which can be used to deaerate the primary bitumen is taught in U.S. Pat. No. 4,116,809, incorporated herein by reference. Another example of a suitable deaeration process, mechanical deaeration, is disclosed in Canadian Patent No. 2,263,858, incorporated herein by reference. Thus, a portion of deaerated bitumen froth can be added at the mixing step (deaerated bitumen froth stream 100 ′), after the mixing step but prior to conditioning (deaerated bitumen froth stream 200 ′) or prior to addition of conditioned slurry into the primary separation vessel for gravity separation (deaerated bitumen froth stream 300 ′).
FIG. 2 shows an example of one possible commercial operation using primary bitumen froth recycle. Crushed oil sand 1 is continuously conveyed via conveyer 3 to an oil sand slurry preparation system 10 . In this embodiment, the oil sand slurry preparation system 10 comprises mix box 11 having a plurality of baffles where the oil sand 1 is mixed with process water 12 and, optionally, NaOH (caustic). The slurry formed in mix box 11 is then dropped through vibrating screen 13 into pump box 14 . Oversize is crushed in crusher 15 and drops through secondary vibrating screen 16 into a second pump box 17 . In the alternative, the oil sand preparation system 10 can be replaced with a compact slurry preparation system as described in Canadian Patent Application No. 2,480,122, incorporated herein by reference, or a cyclofeeder as described in U.S. Pat. No. 5,039,227, incorporated herein by reference. The oil sand slurry in the pump box 14 is then directly pumped to the conditioning pipeline 20 where the oil sand slurry is further conditioned.
Optionally, air and flood (dilution) water 30 is added to the conditioned slurry prior to feeding the slurry to primary separation vessel 40 (“PSV”), where separate layers of primary bitumen froth, middlings and sand tailings are formed. In one embodiment, the PSV may be of the deep cone type (e.g., typically where the angle of cone is about 55° to about 65°). The middlings may be further treated, for example, in a bank of flotation cells 60 , for additional bitumen recovery, or in any other secondary recovery circuit as known in the art such as a secondary separation vessel (“SSV”),
A portion of the primary bitumen froth 45 is continuously withdrawn from the PSV 40 and recycled upstream of the PSV. In one embodiment shown in FIG. 2 , the portion of primary bitumen froth 45 is recycled to the pump box 14 through line 70 to be added to the slurry as it enters pump box. In another embodiment, the portion of primary bitumen froth 45 can be added directly to mix box 11 via line 50 . In yet another embodiment, the portion of primary bitumen froth 45 can be added to one or more points on the conditioning pipeline 20 via line 80 . In yet another embodiment, the portion of primary bitumen froth 45 can be added to the oil sand slurry after pipeline conditioning but prior to dilution with flood water 30 and gravity separation in PSV 40 .
In one embodiment, the primary bitumen froth 55 produced in PSV 40 is steam deaerated in deaerator 42 to produced deaerated primary bitumen froth for further upgrading and the portion of primary bitumen froth to be recycled is taken from deaerator 42 (deaerated primary bitumen froth 95 ) rather than directly from PSV 40 . Thus, deaerated primary bitumen froth 95 is recycled upstream of the PSV to the same steps as the aerated primary bitumen froth.
A schematic of the pilot plant used in Example 1 is shown in FIG. 3 a . Oil sand, process (tumbler) water and, optionally, caustic (NaOH) are added to tumbler 119 where the oil sand is mixed with the water to form a slurry. Residence time of the slurry in the tumbler is generally around 2.0 minutes. The slurry is then screened through reject screen (not shown) having 5/16″ square openings and rejects, i.e. oil sand lumps, greater than 5/16″ are discarded.
The slurry is then transferred to an agitated pump box or mixing tank 114 to keep the slurry in suspension. Residence time of the slurry in the agitated pumpbox or mixing tank 114 is about 5 minutes. Slurry is then pumped via Moyno pump 152 through a coriolis mass flow meter (not shown) to conditioning pipeline loop 120 comprised of 4-inch pipe where the slurry undergoes conditioning. Pipeline loop 120 is approximately 40 meters in length and was designed to provide a mean residence time of approximately 5 minutes. Thus, the total residence time of the oil sand slurry in the tumbler, the agitated pumpbox or mixing tank, and the pipeline is about 12 minutes.
After leaving the pipeline loop 120 , the conditioned slurry is flooded (diluted) with flood water and additional air may be added to the diluted slurry in slurry pipeline 154 which leads to the feedwell (not shown) of primary separation vessel (PSV) 140 . The slurry is then fed into PSV 140 where it separates into separate layers of primary bitumen froth, middlings and sand tailings.
Froth underwash water is added to PSV 140 at a point beneath the layer of bitumen froth that forms. Separated bitumen froth overflows into launder 158 and is removed into a separate froth weigh tank (not shown). This bitumen froth from the PSV is referred to as primary bitumen froth.
Middlings, comprising water, bitumen and solids that collect in the mid-section of the PSV 140 , are removed to one or more secondary flotation cells 160 , each having impellers, to produce lean bitumen flotation froth. This lean froth is then recycled back into PSV 140 for recovery as primary bitumen froth.
For the froth recycle tests discussed below, baffles were installed in the PSV froth launder 158 to split the froth in the desired proportions for recycle. A portion (16% or 33%) of the primary bitumen froth is withdrawn from the PSV froth launder 158 via line 145 and recycled via line 160 or 162 either to the slurry line 154 after the conditioning pipeline loop 120 and flood water addition (but before the pipeline aerator) or the slurry preparation unit mix tank 114 , respectively. In addition, primary bitumen froth could be added directly to the tumbler via line 164 .
A schematic of the pilot plant used in Examples 2 and 3 is shown in FIG. 3 b , which is essentially the same as the schematic in FIG. 3 a except a primary bitumen froth deaeration system 182 has been added. For the froth recycle tests discussed below, baffles were installed in the PSV froth launder 158 to split the froth in the desired proportions for deaeration and recycle.
The primary bitumen froth deaeration system 182 comprises deaerated froth tank 184 , which was cylindrical having a diameter of 43.3 inches and a height of 54 inches. Normal froth level in the tank 184 was 20 inches from the bottom. The tank 184 was equipped with four baffles, each 2 inches wide by 33 inches long and spaced 1 inch away from the wall. The tank 184 was stirred with a 12 inch diameter, three-blade marine impellor located 5 inches off the bottom of the tank. The impellor was on a 1.25 inch diameter shaft, and was stirred with a 3 horsepower motor. Impellor speed was initially investigated, then set at 150 RPM for testing.
The deaerated froth tank 184 was equipped with a heating jacket to maintain froth temperature, and a thermocouple to measure the froth temperature. Recirculation pump 186 on the deaerated froth tank 184 was a Moyno 1L10 model, equipped with a 15 Hp motor. Recirculated froth density was measured with a nuclear density meter. The deaerated froth discharge was pumped from the recycle line 187 through a new 3L2 Moyno pump 188 to the selected discharge destination via line 145 ′.
A portion (16%, 33% or 50%) of the primary bitumen froth is withdrawn from the PSV froth launder 158 , deaerated in primary bitumen froth deaeration system 182 and then the deaerated bitumen froth is recycled via line 145 ′ to the tumbler 119 (line 164 ′) or mix tank 114 (line 162 ′), respectively. The deaerated bitumen froth could also be added to the slurry line 154 via line 160 ′ after the conditioning pipeline loop 120 and flood water addition.
EXAMPLE 1
The following are the data pertaining to a pilot plant run using the pilot plant as shown in FIG. 3 carried out on oil sand sample comprising 10.1 wt % bitumen and 27 wt % fines (<44 μm) using the LEE process where operating temperatures were maintained at about 35° C.:
TABLE 1
Percent PSV Froth Recycle, %
0
16
33
16
33
16
33
Water/Froth Recycle (1:1 Weight
N/A
On
On
Off
Off
On
On
Ratio)
PSV Froth Recycle Location
N/A
Mix
Mix
Mix
Mix
Pipeline
Pipeline
Tank
Tank
Tank
Tank
Bitumen Recovery (Overall), %
72.9*
80.2
90.2
78.2
91.2
83.4
85.2
Bitumen Recovery (Rejects free), %
74.5*
81.9
91.5
79.6
92.4
85.1
87.1
PSV Froth Bitumen, wt %
54.8*
48.0
54.2
54.8
57.8
51.3
50.1
PSV Froth Solids, wt %
15.4*
13.3
13.2
14.3
15.0
14.6
14.9
PSV Middlings Bitumen, wt %
6.6*
6.9
6.1
7.2
1.8
4.9
4.9
PSV Tailings Bitumen, wt %
1.6*
1.5
0.6
1.6
0.6
0.8
0.9
Flotation Unit Bitumen Recovery, %
96.1*
95.7
96.3
96.0
88.0
94.5
94.9
Flotation Underflow Bitumen, wt %
0.31*
0.36
0.27
0.34
0.24
0.32
0.30
*average of three separate runs
The conditions tested included PSV froth recycle to slurry preparation unit (mix tank) with and without water addition, and PSV froth recycle to slurry line, after the pipeline loop and before the aerator with water addition. Recycling 33% of the PSV froth to the slurry preparation unit (mix tank) improved bitumen recovery from approximately 73% to approximately 91% when processing oil sand with 10.1% grade and 27% fines. However, recycling only 16% of the PSV froth to slurry preparation unit only showed a slight improvement in bitumen recovery. Recycle of 16% or 33% of the PSV froth to the flooded slurry in the hydrotransport line (conditioning pipeline) before the PSV also showed slight improvement of bitumen recovery. Addition of process water to the recycled PSV froth did not significantly affect process performance.
EXAMPLE 2
The oil sands used for the following experiments comprised 8.8 wt % bitumen and 51 wt % fines (solids less than 44 μm) and a warm slurry extraction process was used, where operating temperatures were maintained at about 50° C. Table 2 summarizes the results of bitumen recoveries using primary bitumen froth recycle via the deaerated froth tank (DFT) to the tumbler feed (TF).
TABLE 2
Percent PSV Froth Recycle, %
N/A
16
33
50
50
PSV Froth Directed to:
N/A
DFT
DFT
DFT
DFT
DFT Discharge Directed to:
N/A
TF
TF
TF
TF
Bitumen Recovery, %
87.8*
92.7
93.1
95.3
93.4
PSV Froth Bitumen, wt %
51.8*
48.9
48.4
46.5
47.2
PSV Froth Solids, wt %
11.6*
12.7
19.3
22.2
22.4
PSV Middlings Bitumen, wt %
1.90*
0.72
0.43
0.49
0.28
PSV Tailings Bitumen, wt %
0.49*
0.25
0.20
0.09
0.14
Flotation Bitumen Recovery, %
95.2*
88.9
87.5
86.8
75.5
Flotation Underflow Bitumen,
0.11*
0.10
0.07
0.08
0.08
wt %
*average of base case runs
It can be seen from the data in Table 2 that recycling of increasing amounts of deaerated PSV froth to the slurry preparation unit (tumbler feed) of 16%, 33% and 50% resulted in a steady increase in bitumen recovery from 87.8% (base case, with no primary froth recycle) to 92.7%, 93.1% and 95.3% (93.4%), respectively.
EXAMPLE 3
The oil sands used in the following experiments comprised 8.8 wt % bitumen and 51 wt % fines (solids less than 44 μm). A warm slurry extraction process was used where operating temperatures were maintained at about 50° C. Table 3 summarizes the results of bitumen recoveries using primary bitumen froth recycle via the deaerated froth tank (DFT) to the mix tank (MT).
TABLE 3
Percent PSV Froth Recycle,
N/A
16
16
33
33
50
%
PSV Froth Directed to:
N/A
DFT
DFT
DFT
DFT
DFT
DFT Discharge Directed to:
N/A
MT
MT
MT
MT
MT
Bitumen Recovery, %
87.8*
92.5
92.2
94.5
94.4
95.2
PSV Froth Bitumen, wt %
51.8*
58.7
57.3
48.4
46.4
48.5
PSV Froth Solids, wt %
11.6*
14.7
15.8
19.2
19.4
20.5
PSV Middlings Bitumen,
1.90*
0.59
0.41
0.33
0.38
0.26
wt %
PSV Tailings Bitumen,
0.49*
0.25
0.22
0.13
0.07
0.11
wt %
Flotation Bitumen
95.2*
86.3
77.1
89.8
87.2
76.1
Recovery, %
Flotation Underflow
0.11*
0.10
0.12
0.04
0.06
0.08
Bitumen, wt %
*average of base case runs
It can be seen from Table 3 that recycling of increasing amounts of deaerated PSV froth to the slurry preparation unit (mix tank) of 16%, 33% and 50% resulted in a steady increase in bitumen recovery from 87.8% (base case, with no primary froth recycle) to 92.5% (92.2%), 94.5% (94.4%) and 95.2%, respectively.
It is understood that there may be more than one oil sand slurry process line and PSV operating at the same time. Thus, the portion of primary bitumen froth or deaerated primary bitumen froth derived from any PSV can be recycled back to any one or more than one of several process lines that may be operating simultaneously. For example, primary bitumen froth produced from one plant/process line could be added to slurry pump boxes or tumblers in another plant/process line, for example, where lower grade, higher fines oil sand is being mined.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to those embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the full scope consistent with the claims, wherein reference to an element in the singular, such as by use of the article “a” or “an” is not intended to mean “one and only one” unless specifically so stated, but rather “one or more”. All structural and functional equivalents to the elements of the various embodiments described throughout the disclosure that are known or later come to be known to those of ordinary skill in the art are intended to be encompassed by the elements of the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. | A process for extracting bitumen from oil sand, comprising: mixing oil sand with process water to produce an oil sand slurry containing bitumen, sand, water and entrained air; conditioning the oil sand slurry; optionally flooding the conditioned oil sand slurry with flood water to dilute the slurry, if required; introducing the slurry into a primary separation vessel wherein separate layers of primary bitumen froth, middlings and sand tailings are formed; removing a portion of the primary bitumen froth from the primary separation vessel and recycling the portion of primary bitumen froth to that step of the process upstream of the primary separation vessel to join and mix with the feed stream moving to the primary separation vessel; and thereafter retaining said feed stream in said primary separation vessel to produce primary bitumen froth. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. application Ser. No. 10/547,192 filed on May 5, 2006, which is a U.S. national stage application of International Application No. PCT/CH2004/000047 filed on Jan. 29, 2004 and which claims priority to Swiss Application Nos. 341/03 filed on Mar. 5, 2003 and 517/03 filed on Mar. 25, 2003, the entire contents of which are incorporated herein by reference.
BACKGROUND
Containers which were conventional in the past and which made of white or colored sheet metal, glass or also ceramic are being increasingly displaced by plastic containers. Mainly plastic containers are used for packaging of fluid substances, for example beverages, oil, cleaning agents, cosmetics, etc. The low weight and lower costs play a not insignificant part in this substitution. The use of recyclable plastic materials and overall more favorable total energy balance in their production also contribute to promoting the acceptance of plastic containers, especially plastic bottles, among consumers.
The production of plastic containers, especially plastic bottles, for example from polyethylene or polypropylene, takes place in an extrusion blowing process, especially in a process of blowing extruded tubes. In doing so a plastic tube is extruded from an extruder head, placed in blow molding tools, inflated by way of a blowing mandrel by overpressure, and hardened by cooling. The extrusion blowing machines used for this purpose generally have at least one extruder for supply of the plastic material. The output of the extruder is connected to the extruder head and on its discharge nozzle which can preferably be regulated in opening width an extruded tube or one extruded in several layers emerges. The extruded tube is transferred to a blow molding tool and inflated within its cavity with a blowing mandrel. The plastic tube can have one or more layers, it can be extruded as a tube with visual strips, decorative strips, or, relative to the periphery, with several segments for example of different colors.
The blowing station with the blowing mandrel is conventionally located laterally from the extrusion head and the blow molding tool which is supplied with the extruded tube must be moved into the blowing station where then the blowing mandrel is conventionally transported from overhead into the blow molding cavity. For continuous operation in one type of known extrusion blowing machines, there are conventionally two blowing stations. Each blowing station is equipped with one blow molding tool. The blowing stations are located opposite one another on either side of the extruder and have blow molding tables with the blow molding tools which are moved alternately under the extruder head in order to receive the extruded tube. In doing so the blow molding tool is opened for retrieving the tube. After closing the blow molding tool the tube is cut off between the extrusion head and the blow molding tool. Afterwards the blow molding table is moved again into the blowing station, where the blowing mandrel is transported into the cavity of the blow molding tool and the tube is inflated according to the blow molding cavity and afterwards removed. For multiple extrusion heads and multiple blow molding tools each blowing station is equipped with a corresponding number of blowing mandrels which are jointly transported into the blow molding cavities. Altogether the extruder with the extruder head and the two blow molding stations form roughly the shape of a T. The extruder with the extruder head constitutes the long leg of the T, while the two blowing tables can be moved alternately along the short crosspiece halves to under the extruder head.
Extrusion blowing machines of the above described type have been tested and allow high production performance. But there is still a desire for improvements in order to further reduce the required tool investments, i.e. the costs per blow molding cavity. The necessity of moving the blow molding tables with the blow molding tools laterally to the blowing stations leads to dead times which result from the path to be traversed and the speed of motion of the blow molding tables. Due to the relatively great masses which must be accelerated and braked again, the speed of motion can not be selected to be optionally large. Also the paths to be traversed laterally cannot be further shortened for construction reasons. The extruded tube must be cut off after the blow molding tool is filled. This conventionally takes place by a laterally supplied cutting blade. The tube part which continues to be extruded and which projects from the extrusion nozzle swings back and forth after the cutting process. In particular, for very high clock cycles the swinging of the tube can lead to problems in the transfer of the tube to the blow molding cavity.
Extrusion blowing machines are known in which a number of blow molding tools are located on a rotating wheel. The wheel stands roughly vertically and guides the blow molding tools roughly tangentially to the plastic tube which has been continuously extruded by the extrusion head. Shortly before reaching the extruded plastic tube, the guided blow molding tool is opened to retrieve the tube. As the wheel continues to turn, the blow molding tool is closed around the inserted tube and the latter is finally cut off during further turning. The arrangement of the blow molding tools and the speed of rotation of the wheel are chosen such that the tube is only cut off when the following blow molding tool has closed around the next tube piece. The tube which is located in the cavity of the blow molding tool as the wheel continues to turn finally travels into the blowing station where it is inflated by way of a blowing mandrel which is inserted laterally into the mold tool according to the blow molding cavity. Finally, the inflated hollow body is discharged from the blow molding tool by opening. The blow molding tool which is located on the rotating wheel is closed again as motion continues and is moved again to the extrusion head in order to accommodate another extruded tube.
The disadvantage in the wheel blowing machines is the circumstance that due to the large number of separate blow molding tools located on the wheel, they require a relatively high investment cost for preparation of the blow molding tools. In general the blow molding tools are not completely identical. This can lead to quality differences in the manufactured hollow bodies from blow molding tool to blow molding tool. The use of blow molding tools with several blow molding cavities is relatively difficult and expensive. The blow molding tools can only be attached at fixed mounting points on the wheel. They are fixed according to the height of the blown hollow body which can be produced at maximum with the machine. The mounting points, once established, can no longer be changed. This is also a result of the mechanical controls which are conventional in these machines via control cams, cam disks and the like. If containers with a smaller height are to be blown on the wheel blowing machine, the smaller blow molding tools mounted on the periphery of the wheel have a greater angular distance from one another. Since the plastic tube emerges continuously from the extrusion head, this leads to larger amounts of scrap in the areas between the two blow molding tools. The extruded plastic tube is accepted by the blow molding tool which has moved past along a circular shape under the extrusion head. Arc motion is superimposed on the lateral feed motion of the closing blow mold halves. By a radius of the wheel as large as possible, the attempt is made to keep this arc motion of the blow mold halves as small as possible when the plastic tube is being accepted; but it cannot be completely eliminated. The circumstance that the tube between two successive blow molding tools on the one hand is held by the extruder head and on the other hand by the advancing blow molding tool, cannot change anything in the geometrical relationships. Under certain circumstances therefore for more complex container geometries it can occur that the tube is not ideally inserted into the blowing cavity and is partially pinched between the adjoining areas of the closing blow mold halves. This can lead to unwanted scrap.
SUMMARY
A blow molding process and an extrusion blowing machine will be devised which allow reliable processing of different raw plastic products. With respect to the configuration of the container geometries there should be as much free space as possible, and containers with very complex geometry with very narrow specifications will also be producible. In the production of critical container geometries or thin-walled containers production reliability as high as possible is to be ensured. The process and device for extrusion blowing of hollow bodies will be compatible for production of large and small geometries. Unnecessary scrap is to be largely avoided. The process and the device are to be modified such that regardless of the number of cavities per blow molding tool, largely identical container properties and quality parameters will be achieved. The adjustment data determined in the test will be largely applicable unchanged to production plants. The space requirement compared to existing machines should not be greater, it should even be possible to reduce it. Dead times as occur in known machines when the blow molding tools move sideways into the blowing stations will be reduced.
In the process for producing hollow bodies, especially plastic bottles, a segment of a plastic tube is placed in a cavity of a blow molding tool by the extruder head in a definable cycle. Within the blow molding tool the plastic tube is inflated via a blowing mandrel by overpressure according to the blow molding cavity. The finish-blown hollow body is finally removed from the mold. As claimed in the invention the plastic tube is continuously held during the entire extrusion and blowing cycle on the opposing sides of the blow molding tool arrangement.
In the process as claimed in the invention the plastic tube is continuously held during an entire production cycle, i.e. during the entire extrusion and blowing cycle, on opposite sides of the blow molding tool arrangement. In this way the plastic tube is permanently guided and faulty positions can be avoided. This establishes the prerequisite for always placing a tube which has been extruded from an extrusion nozzle in the same blow molding cavity. All the hollow bodies produced with an extrusion nozzle-blow molding cavity arrangement are subject to the same adjustment and tool parameters in this way. Quality differences as a result of blow molding cavity tolerances of different sizes in arrangements with several different blow molding tools are eliminated. Dead times which take place by lateral displacement of the blow molding tool arrangement relative to the extruder head are eliminated, since the blow molding tool arrangement is aligned essentially only to the transport direction of the plastic tube. The plastic tube which is located in the blow molding cavity is inflated immediately after feed of the blow molding cavity with an extruded plastic tube. The plastic tube is kept in a defined position during the entire extrusion and blowing cycle and can no longer swing around its axis. The extruder head and the blow molding tool arrangement during the entire extrusion and blowing process remain in a definable and adjustable, geometrical positional relationship, and the plastic tube can always be optimally accepted. In this way, for complicated geometries of the blow molding cavity the danger of unintentional pinching of the plastic tube is reduced. The process guidance as claimed in the invention makes it possible if necessary to change in a concerted manner the location of the extruded plastic tube with reference to the blow molding cavity in order to take into account special geometrical requirements.
In one advantageous version of the process as claimed in the invention, the plastic tube is cut off only after complete inflation of the hollow body. The cutting-off can take place by controlled squeezing off or shearing off. Preferably a cutting blade or the like is used for this purpose. This process version differs both from the blowing process with the known wheel blowing machines in which the tube is sheared off essentially uncontrolled after acceptance by the blow molding tool as the wheel continues to turn, and also from the continuous and discontinuous blowing process with known extrusion blowing machines in which the plastic tube is cut in a controlled manner before the actual blowing process. The process guidance as claimed in the invention results in that the blowing mandrel must be synchronized for a certain time with the motion of the extruder head and/or the extrusion or transfer speed of the plastic tube to the blow molding tool arrangement. This simple measure however ensures that the tube is held in a controlled manner in each phase of the production cycle.
Separation of the plastic tube takes place advantageously on the side of the blow molding tool arrangement facing way from the extruder head. In this way the guidance of the tube over the finish-inflated hollow body which is located on the blowing mandrel and over the extruder head is ensured before cutting off. The tube material scrap can always be kept as small as possible regardless of the height of the blow molding cavity by the arrangement of the point of separation in the immediate vicinity of the mouth of the blow molding cavity.
With reference to the direction of motion of the plastic tube, the blow molding tool means is located between the extruder head and the blowing mandrel. The blowing mandrel is transported through the mouth of the blow molding cavity which is located on the side of the blow molding tool arrangement facing away from the extrusion nozzle. The output of the extrusion nozzle and the axial extension of the blowing mandrel are arranged such that they are essentially axially flush.
In one version of the invention, to reduce the dead times for each blow molding cavity there are two or more blowing mandrels. The blowing mandrels can be for example located next to one another and can supplied in alternation to the openings. In one alternative version several blowing mandrels are attached to the central blowing mandrel support such that they are used in succession by rotation of the blowing mandrel support. For example, the blowing mandrel support can carrying two blowing mandrels which are opposite one another offset by 180°. In this version, after inflating the tube and opening the blow molding tool arrangement the blowing mandrel support is turned by 180°. The second blowing mandrel is thus already prepared for inflation of another tube section while the hollow body on the first blowing mandrel still waits for its removal. It goes without saying that there can also be rotary blowing mandrel supports with 3, 4 or more blowing, mandrels. The angle by which the blowing mandrel support must continue to be turned derives from the division of 360° by the number of blowing mandrels.
The arrangement on the side of the blow molding tool arrangement facing away from the extrusion nozzle also offers the possibility of providing each blowing mandrel with a calibration means with which the opening of the blown hollow body is calibrated during the blowing process. In this way a separate finishing station in which this process must be repeated is eliminated.
In a continuous extrusion blowing process, the plastic tube is continuously extruded from the extrusion nozzle of the extruder head. After transfer of the extruded plastic tube to the blow molding cavity and during the entire blowing process, the relative distance of the extruder head from the blow molding tool arrangement is increased so that during further extrusion it does not strike the surface of the blow molding tool arrangement and the tube can be kept in a controlled alignment. This takes into account the circumstance that the plastic tube is continuously extruded from the extrusion nozzle while the inflation process in the mold cavity of the blow molding tool arrangement is a discontinuous process.
The relative change in the distance between the extruder head and the blow molding tool arrangement takes place at least with a speed which corresponds to the exit speed of the plastic tube from the extrusion nozzle. This ensures that the extruded tube does not run onto the surface of the blow molding tool arrangement. In the choice of a higher rate of change of the distance than the extrusion speed, the plastic tube which is clamped in areas in the blow molding tool arrangement is pulled therefore out of the nozzle tool. In this way for example the wall thickness of the extruded plastic tube can be changed in a concerted manner. A thin-walled tube can thus be produced with a relatively large nozzle gap. On the one hand this has the advantage that in spite of the high throughput the pressure in the extruder head can be kept comparatively low, and on the other hand the dissipation and thus the temperature increase in the tube become less. Another advantage is that even when processing highly swelling materials a thin-walled tube can be produced, since as a result of the larger nozzle gap and the associated lower shear the danger of a melt rupture is reduced. It can also be provided that the relative speeds between the extruder head and the blowing mandrel or blow mold during continuous tube discharge are changed continuously according to an stretching program in order to influence the tube wall thickness to the desired degree.
To achieve a change in distance between the extruder head and the blow molding tool arrangement, it is possible to move the extruder head or the blow molding tool arrangement away or to carry out a combination of the two movements. The adjustment of only one of the two equipment parts simplifies the construction and the control of the sequences of motion. For considerations of construction it is advantageous if the change in the distance takes place only by moving the extruder head away relative to the blow molding tool arrangement which is stationary with respect to its location. On the one hand, in the area of the extruder head there is more space for mounting of lifting means. On the other hand, it is advantageous for the feed of the blowing mandrel if the blow molding tool arrangement retains its position essentially unchanged during the entire blowing cycle. The blow molding tool arrangement must execute only one opening and closing motion for accommodating the tube section in the blow molding cavity. These processes can be controlled more easily and exactly if the blow molding tool arrangement does not execute any further motion.
In a discontinuous blowing process the plastic tube is extruded discontinuously from the extrusion nozzle of an extruder head which is made as a breaker head into blow molding cavity. During ejection of the plastic tube the distance of the blowing mandrel from the breaker head is increased. The structure of the extrusion blowing machine for the discontinuous process corresponds largely to that of continuous machines. In contrast to the known discontinuous process, however, the tube is permanently held and guided in a controlled manner during the production process. In this way uncontrolled swinging of the tube is prevented. Moreover holding the tube if necessary can also be used for controlled stretching or changing its position.
In the discontinuous process the tube must also be prevented from running onto the surface of the blow molding tool arrangement. To do this, the rate of change of the distance of the blowing mandrel from the breaker head is set to be greater than or equal to the ejection speed of the plastic tube from the extrusion nozzle.
The process as claimed in the invention in which the plastic tube is guided in a controlled manner during the entire production cycle allows process guidance with any direction of motion of the plastic tube. While the known processes are limited essentially to the vertical extrusion direction of the plastic tube, guidance of the tube also enables an oblique, even horizontal orientation. For reasons of compatibility with existing machines however axial alignment is preferred. An axially aligned arrangement of the extruder head, the blow molding tool arrangement and the blowing mandrel allows relatively simple control of the axial components of motion.
Advantageously the discharge rate of the plastic tube, the extruder head motion, the adjustment motion of the width of the extrusion nozzle, the blowing mandrel motion and the opening and closing motion of the blow molding tool arrangement can be adjusted individually and matched to one another. This allows implementation of optimized sequences of motion which are matched to the requirements of the container which is to be blown, without thus needing to undertake changes on the overall concept of the process as claimed in the invention. For example, it can be provided that the plastic tube during the production cycle is tilted in order to be able to optimally use special geometries of blow molding cavities and to produce special container geometries.
In one advantageous version of the invention the blow molding tool arrangement comprises at least two mold parts which can be separated from one another, and which are moved for opening and closing the blow molding tool essentially perpendicular to the extrusion direction out of an open end position into a closed end position and vice versa. For example it can be a blow molding tool which in addition to the mold parts for building up the container body also has a raisable bottom part. For a blow molding tool arrangement fixed in its position the actuating means can likewise be located stationary for the opening and closing process. Omitting an additional component of motion simplifies the mechanical structure and also contributes to reducing the control cost for the controlled movements of the mold parts.
The advantages of the process were explained using the example of an extruder head with only one extrusion nozzle and one blow molding tool arrangement with only one blow molding cavity. The blow molding tool arrangement can also be for example a single tool or an arrangement of tools with one or more blow molding cavities which are coupled to one another. In one advantageous process version an extruder head with a multiple extrusion nozzle tool and a blow molding tool arrangement which is equipped with a corresponding number of blow molding cavities are used. Moreover there is a number of blowing mandrels which is one or more times the number of blow molding cavities and which can be transported into the mouths of the blow molding cavities for inflating the plastic tubes. In this way, in one blowing cycle with the machine and tool parameters remaining the same, a larger number of hollow bodies, for example plastic bottles, can be produced. In this way the throughput is increased and the productivity of a multiple blow molding tool arrangement can be further improved.
An extrusion blowing device which is suited for executing the process as claimed in the invention for producing hollow bodies, especially plastic bottles, has an extruder head which is located in an equipment frame with an extrusion nozzle, a blow molding tool arrangement with at least one blow molding cavity, at least one blowing mandrel and at least one separation means. As claimed in the invention, on the opposing sides of the blow molding tool arrangement there are holding means for the plastic tube. The separating means is provided on the side of the blow molding tool arrangement facing away from the extruder head.
By providing holding means for the plastic tube on either side of the blowing tool arrangement, the tube is continuously held during the entire production cycle of a container. In this way the prerequisites for use of a single blow molding cavity per extrusion nozzle are created. Dead times by lateral movements of the blow molding tool means are avoided. Faulty positions are avoided by the permanent guidance of the plastic tube. If it appears to be necessary, the position of the tube can however also be changed in a concerted manner relative to the extrusion direction. In this way for example the requirements of more complicated container geometries can be taken into account. All the hollow bodies which are produced with an extrusion nozzle-blow molding tool arrangement are subject to the same adjustment and tool parameters. Quality differences as a result of tool tolerances of different sizes in several different blow molding tools are eliminated. Dead times which occur by the lateral displacement of the blow molding tool arrangement relative to the extruder head can be avoided since the blow molding tool arrangement is aligned essentially only to the transport direction of the plastic tube. The inflation of the plastic tube which is located in the blow molding cavity takes place directly after feed of the blow molding cavity with the extruded plastic tube. The plastic tube is fixed during the entire production cycle in a defined position and can no longer swing around its axis. The extruder head and the blow molding tool arrangement during the entire extrusion and blowing process remain essentially in a definable and adjustable, geometrical positional relationship, and the plastic tube can always be optimally accepted. In this way, even for more complicated geometries of the blow molding cavity, the danger of unintentional pinching of the plastic tube is reduced.
The holding devices for the tube on the one hand are formed by the blowing mandrel and on the other by the extruder head. By using already existing machine components for the holding functions the structure can be kept simple and the construction can be kept compact.
In an arrangement which is also advantageous for reasons of space, the blow molding tool arrangement is located between the extruder head and the blowing mandrel. The blow molding cavity has a mouth on the side of the blow molding tool arrangement facing away from the extrusion nozzle in which the blowing mandrel can be transported into the blow molding cavity. In this arrangement the adjustment and feed movements of the hardware components are limited essentially to movements along the direction of motion of the plastic tube or essentially vertically. This leads to lower mechanical stresses and reduces the vibrations and shaking which occur during operation.
One embodiment of the invention calls for two or more blowing mandrels which can be supplied in alternation for the blow molding cavity. In doing so the blowing mandrels can be located for example next to one another and can be moved alternatingly into the correct position. The transport paths of the blowing mandrels are very short. In this way the dead times for the feed of the blowing mandrel can be kept short. One alternative version calls for the blowing mandrels to be mounted on a central blowing mandrel support, and to be brought into use in succession by rotation of the blowing mandrel support. For example, the blowing mandrel support can bear two blowing mandrels which are opposite one another offset by 180°. In this version, after inflating the tube and opening the blow molding tool, the blowing mandrel support is turned by 180°. The second blowing mandrel is thus already prepared for inflation of another tube section, while the hollow body on the first blowing mandrel waits for its removal. It goes without saying that rotary blowing mandrel supports with 3, 4 or more blowing mandrels can also be provided. The angle by which the blowing mandrel support must continue to be turned then results from the division of 360° by the number of blowing mandrels.
Advantageously, on each blowing mandrel there are calibration means with which during the blowing process the opening of the blown hollow body can be calibrated. In this way a time-consuming finishing step can be eliminated.
To prevent the plastic tube from running against hardware components or sagging during the extrusion and blowing cycle, there are actuating means with which the relative distance between the extruder head and the blow molding tool arrangement can be adjusted. One advantageous version calls for the extruder head to be connected to the actuating means and the distance relative to the stationary blow molding tool arrangement to be adjustable. This arrangement has the advantage that on the blow molding tool arrangement precautions need be taken essentially only for the opening and closing of the mold parts. This simplifies the sequences of motion and the control cost.
The extruder head can be made for continuous extrusion of the plastic tube. In this version the change in the distance between the extruder head and the blow molding tool arrangement takes place at least with the extrusion speed of the plastic tube. In one alternative version of the invention the extruder head is made as a breaker head for discontinuous ejection of the plastic tube. In this version, the distance of the blowing mandrel can be adjusted at least with the ejection rate of the plastic tube relative to the blow molding tool arrangement.
Since on both sides of the blow molding tool arrangement there are holding means for the plastic tube, the alignment of the extrusion nozzle, the blow molding tool arrangement and the blowing mandrel or mandrels can be selected at will. For reasons of compatibility with existing devices and system components, however an arrangement is preferred in which the extruder head has an essentially vertically aligned extrusion nozzle and the blow molding tool arrangement and the blowing mandrel or mandrels are arranged vertically under one another. The vertical arrangement also uses the action of gravity on the extruded plastic tube which is stabilizing to a certain extent.
The blow molding tool arrangement comprises at a least two mold parts which can be separated from one another and which can be moved for opening and closing essentially perpendicular to the extrusion direction of the plastic tube out of an open end position into a closed end position and vice versa. For example, it can be a blow molding tool which in addition to the mold parts for building up a container body also has a raisable bottom part. For a blow molding tool arrangement which is fixed in its position the actuating means for the opening and closing process can likewise be located stationary. Omitting an additional movement component simplifies the mechanical structure and also contributes to reducing the control cost for controlled movements of the mold parts.
For reasons of higher throughput, it is advantageous if the extruder head has several extrusion nozzles and the blow molding tool arrangement is equipped with a corresponding number of blow molding cavities. Preferably there are a number of blowing mandrels which is one or more times the number of blow molding cavities. Aside from the higher throughput and the improved productivity of the multiple blow molding tool, in this version a larger number of hollow bodies, for example, plastic bottles, can be produced with uniform machine and tool parameters in one blowing cycle. This has advantages with respect to the uniformity of the quality of the products made.
Other advantages and features of the invention result from the following description with reference to the schematics of one embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic of an extrusion blowing machine of the prior art;
FIG. 2 shows a diagram of an arrangement of an extruder head, a mold tool and a blowing mandrel as claimed in the invention; and
FIGS. 3-11 show schematics for explanation of the process as claimed in the invention.
DETAILED DESCRIPTION
The extrusion blowing machine of the prior art shown only schematically in FIG. 1 is labelled overall with reference number 1 . The structure of these long-stroke extrusion blowing machines has been known for a long time and is described for example in Blow Molding Handbook , edited by Donald V. Rosato and Dominick V. Rosato, 1989, ISBN 1-56990-089-2, Library of Congress Catalog Card Number 88-016270. FIG. 1 is therefore limited to the components of the extrusion blowing machine 1 which are absolutely essential for understanding. This embodiment is a two-station blowing machine, as is also offered by the applicant. It has an extrusion unit 2 and two blowing stations 12 , 13 . The extrusion unit 2 comprises an extruder 3 for the plastic granulate and an extruder head 4 which is connected to it and which has at least one extrusion nozzle 5 . The blowing stations 12 , 13 each have one blowing head with a blowing mandrel. Each blowing station 12 , 13 is equipped with a blow molding table 14 , 15 in which blow molding tools 6 are mounted. The blow molding tools 6 each surround a blow molding cavity 7 which corresponds to the shape of the hollow body which is to be produced, for example a bottle. The blow molding cavities 7 on their top facing the extruder head 4 have a mouth 8 . The blow molding tables 14 , 15 can be moved in alternation out of their side end positions in the blowing stations 12 , 13 into a position in which the mouth 8 of the blow molding tool 6 is axially flush with the output of the extrusion nozzle 5 . The lateral displacement of the blow molding tables 14 , 15 takes place essentially perpendicular to the lengthwise extension of the extruder 3 .
The plastic granulate which is supplied via the extruder 3 is melted in the extruder 3 and/or in the extruder head 4 and is extruded from the extrusion nozzle 5 as a continuous tube. The tube can be extruded in one or more layers. To do this there can also be other extruders which transport the required different plastic materials to the extruder head 4 . The blow molding tables 14 , 15 with the blow molding tools 6 are moved in alternation out of their end positions into the blowing stations 12 , 13 laterally to under the extruder head 4 , the blow molding tools 6 are opened and a piece of the extruded tube is retrieved. Afterwards the respective blow molding table 14 , 15 is moved back again into its end position in the blowing station 12 and 13 . There, the hollow body is inflated using a blowing mandrel which has been transported into the cavity 7 through the mouth 8 . The finished hollow body is ejected and the cycle repeated. While a tube is being inflated in one blow molding station 12 , the blow molding table 15 of the second blowing station 13 is moved laterally to under the extrusion head 4 in order to retrieve another piece of the extruded tube. In this way continuous operation is possible.
FIG. 2 schematically shows an arrangement of the hardware components important to the invention. Here the designations from FIG. 1 were retained in order to enable direct comparison. Reference number 4 in turn labels the extruder head which has the extrusion nozzle 5 . Reference number 6 stands for the single blow molding tool of the extrusion blowing device which in this embodiment comprises two blow mold halves 8 , 9 which are shown in the opened state. The two blow mold halves 8 , 9 border the blow molding cavity 7 with a mouth 10 which is located on the side of the blow molding tool facing away from the extrusion nozzle 5 . Proceeding from a practical arrangement of the hardware components, the mouth 10 of the blow molding cavity 7 is on the bottom of the blow molding tool 6 . A blowing mandrel which is labelled with reference number 11 is mounted on the blowing mandrel support 16 . In this embodiment the blowing mandrel support 16 has two blowing mandrels 16 which can be moved alternately to under the mouth 10 of the blow molding cavity 7 by turning the blowing mandrel support 16 by 180°. The extruder head 4 and the sole blow molding tool 6 are arranged such that the axis of the blow molding cavity 7 and the output of the extrusion nozzle 5 on the extruder head 4 are axially flush with one another. In the embodiment shown, the blowing mandrel pair 11 is also arranged such that it is flush with the axis of the blow molding cavity 7 . This however is not a compelling requirement. It goes without saying that for an eccentrically arranged mouth of the blow molding cavity the blowing mandrel can be accordingly offset laterally. But it is important to the arrangement as claimed in the invention that the extruder head 4 and the blow molding tool 6 are flush with one another in the axial direction. Reference number 17 labels a blade which is used to cut off the individual blown hollow bodies.
The arrows shown in FIG. 2 indicate the adjustability of the individual hardware components. Thus, the extruder head 4 can be adjusted essentially only with respect to its height in order to change the distance to the blow molding tool 6 during the extrusion and blowing process. For the required base setting and fine adjustment however it has all degrees of freedom. The blow mold halves 8 , 9 of the blow molding tool 6 can only be moved laterally out of an open end position into a closed end position and vice versa. In the embodiment shown, the blow molding tool 6 does not have vertical adjustability. The blowing mandrel pair 11 which is mounted on the blowing mandrel support 16 is vertically adjustable in order to be able to be transported into the mouth 10 of the blow molding cavity 7 and withdrawn again. In order to be able to use the blowing mandrels 11 in alternation, the blowing mandrel support 16 can also be turned.
FIGS. 3 to 11 serve to explain the process for production of a plastic hollow body. FIG. 3 shows the automatic cycle beginning with the state in which the blow molding tool 6 is closed. The tube T which has been continuously extruded from the extrusion nozzle 5 of the extruder head 4 is indicated by T. One of the two blowing mandrels 11 is transported into the mouth 10 of the blow molding cavity 7 . Reference number 17 stands for the blade which is inactive in this state. In the state shown in FIG. 3 a tube which is located in the blow molding cavity is inflated according to the blow molding cavity. During the blowing process the extruder head 4 is continuously raised and the vertical distance to the blow molding tool is continuously increased. This is indicated in FIG. 4 by the lengthening of the extruded tube T. If the extruder head is raised with a speed which is greater than the extrusion speed of the plastic tube, the tube is pulled out of the extrusion nozzle and stretched, and its wall thickness decreases. During raising of the extruder head 4 if necessary a wall thickness control program can be run in which the wall thickness of the tube can be changed to the desired extent by varying the gap width of the extrusion nozzle. A finish-blown bottle B hangs on the second blowing mandrel 11 which is located outside the blow molding cavity. In this position it could be subjected for example to an aftercooling process or other finishing which is not detailed.
The end of the blowing process is shown in FIG. 5 . The extruder head 4 is moved still further from the blow molding tool 6 and is raised further. The inflated bottle which is located in the blow molding cavity 7 is vented by the blow molding tool 6 . The bottle B hanging on the lower blowing mandrel 11 is removed. After this process, the blow mold halves 8 , 9 of the blow molding tool 6 are raised; this is indicated in FIG. 6 . The extruder head 4 is still being raised in doing so. After the bottle B which has been inflated in the blow molding cavity has been completely removed from the blow molding cavity 7 , the movement of the extruder head 4 is stopped and vice versa. As is shown in FIG. 7 , the extruder head 4 with the extruded tube piece T and the finish-blown bottle B which is still connected to it is moved down in the direction of the blow molding tool 6 . The blowing mandrel 11 which is mounted on the blowing mandrel support 16 is likewise lowered.
FIGS. 6 and 7 clearly show that the extruded tube T even with the blow molding tool 6 opened is held in a position which is aligned in an axially defined manner. Because the tube is still connected to the finish-blown container B, the tube on the one hand is fixed by the extrusion nozzle 6 and on the other via the blowing mandrel 11 . In this way swinging of the tube T is reliably prevented. The rate of lowering of the extrusion head 4 and of the blowing mandrel 11 takes place advantageously synchronously and corresponds at least to the extrusion speed of the tube T. By a definable difference of lowering speeds the continuously extruded tube T can be stretched to the desired extent. The axially aligned arrangement of the extruder head 4 , of the blow molding tool 6 and of the blowing mandrel 6 also allows relatively simple control of the axial components of motion. Advantageously the exit speed of the plastic tube T, the motion of the blowing mandrel 11 and the adjustment motion of the width of the extrusion nozzle 5 can be adjusted individually and matched to one another. This allows implementation of optimized motion sequences which are matched to the requirements of the container B which is to be blown without in this way needing to undertake changes in the overall concept of the axially aligned motion.
FIG. 8 shows the state in which the blowing mandrel support 16 has reached its lowest position. At this point, the halves of the blow molding tool 6 are closed again in order to inject a new tube section in the mold cavity. Shortly before the blow molding tool 6 is completely closed, the blade 17 is supplied laterally in order to separate the finish-blown bottle B from the scrap piece projecting out of the mouth of the blow molding cavity. This is indicated in FIG. 8 by a double arrow. The extruder head 4 in the meantime has again reversed its direction of motion and is raised again. After separation, the blowing mandrel support 16 is turned in order to align the second blowing mandrel 11 to the mouth of the blow molding cavity. During rotation of the blowing mandrel support 16 it can be supplied to the blow molding tool 6 . The rotation and vertical adjustment of the blowing mandrel support 16 are shown in FIG. 9 by the corresponding arrows. During this process the extruder head 4 is raised again. FIG. 10 shows the state in which the rotation process of the blowing mandrel support 16 has been completed and the blowing mandrel 11 has reached its correct stroke position. Afterwards it is transported into the mouth 10 of the blow molding cavity 7 . In doing so the later opening of the bottle to be inflated is calibrated. Preliminary blowing can be started during transport of the blowing mandrel 11 into the blow molding cavity 7 . The extruder head 4 is raised further in doing so. In FIG. 11 the blowing mandrel 11 is finally transported into the blowing mandrel cavity of the blow molding tool 6 and the production cycle starts again from the front. FIG. 11 corresponds to FIG. 3 here.
The schematics show an extruder head with only one extrusion nozzle and a blow molding tool with only one blow molding cavity. It goes without saying that the described arrangement and the described process can also be used in extrusion blowing devices with multiple nozzle tools and multiple blow molding tools or arrangements of single and/or multiple blow molding tools. The number of blowing mandrels is matched to the number of blow molding cavities here.
The invention has been explained using the example of a continuous extrusion blowing process and a corresponding devised device with a vertical arrangement of the extruder head, of the blow molding tool, and of the blowing mandrels. It goes without saying that the hardware components can also be arranged in a horizontal or any alignment according to the extrusion direction. The process as claimed in the invention can also be used in a discontinuous extrusion blowing process and accordingly a discontinuous extrusion blowing machine can also be produced. The decisive factors in a discontinuous process are likewise providing holding means for the tube on either side of the blow molding tool arrangement and the sequence of the arrangement of the extruder head, the blow molding tool arrangement and the blowing mandrel. It is important to the invention that the extruded tube is held in a controllable position during the entire production cycle and the tube is cut off only after inflation and removal of the container from the mold. The point of separation is located on the side of the blow molding tool arrangement facing away from the extruder head.
It will be appreciated by those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restricted. The scope of the invention is indicated by the appended claims rather than the foregoing description and all changes that come within the meaning and range and equivalence thereof are intended to be embraced therein. | A device and method are disclosed for the production of hollow bodies, especially plastic bottles, wherein a section of a plastic flexible hose is placed in a cavity of a blow mold by an extruder head according to a predefined clocked pulse. The plastic flexible hose is inflated inside the blow mold by a blow mandrel by overpressure according to the blow mold cavity. The manufactured inflated hollow body is subsequently removed from the mold. The plastic hose can be continually held on opposite sides of the blow mold arrangement during the entire extrusion and blow cycle. | 1 |
RELATED APPLICATION
This application is a continuation-in-part of U.S. Ser. No. 07/138,808, filed Dec. 28, 1987, now abandoned and U.S. Ser. No. 07/168,225, filed Mar. 15, 1988, now abandoned.
BACKGROUND OF THE INVENTION
Zidovudine (AZT) is now a marketed product which is approved for the management of humans with symptomatic HIV infections (AIDS and advanced ARC). U.S. Pat. No. 4,724,232 issued Feb. 9, 1988 with claims to the treatment of AIDS and ARC using AZT.
The present invention is to a compound 1-(3-azido-2,3-dideoxy-β-D-erythropentofuranosyl)-5-methyl-2(1H)-pyrimidinone which when systemically administered to a mammal permits the mammal, e.g., a human, to generate (form) zidovudine in vivo to treat the HIV infection or other infection, e.g., a gram-negative bacterial infection.
BRIEF SUMMARY OF THE INVENTION
This invention is directed to a compound 1-(3-azido-2,3-dideoxy-β-D-erythropentofuranosyl)-5-methyl-2(1H)-pyrimidinone which is converted into 3'-azido-3'-deoxythymidine, also known as azidothymidine or AZT (generic name zidovudine), in the body of a mammal, e.g., human, by body enzymes. Such enzymes are believed to include xanthine oxidase/hydrogenase and/or aldehyde oxidase. AZT is a compound approved for sale to treat AIDS and ARC in humans. AZT is also active against gram-negative bacteria, e.g., E. coli, in animals. Thus, the compound of this invention is useful in treating HIV infections--AIDS and ARC in humans, as well as treating animals for gram-negative bacterial infections, e.g., E. coli infections.
The invention is also directed to the 5'-esters of 1-(3-azido-2,3-dideoxy-β-D-erythro-pentofuranosyl)-5-methyl-2(1H)-pyrimidinone and the pharmaceutically acceptable salts thereof as well as the pharmaceutically acceptable salts of 1-(3-azido-2,3-dideoxy-β-D-erythro-pentofuranosyl)-5-methyl-2(1H)-pyrimidinone.
DETAILED DESCRIPTION OF THE INVENTION
It has been found that the compound of formula (I) below is converted into 3'-azido-3'-deoxythymidine (sometimes referred to as azidothymidine or AZT), generic name zidovudine in vivo when given systemically to a mammal, e.g., a human.
It is thus possible to generate zidovudine in the body (i.e., in vivo) by systemically administering the compound of formula (I) to mammals including humans wherein the compound of formula (I) is acted upon by xanthine oxidase/dehydrogenase or aldehyde oxidase in the body and is thereby converted into zidovudine. Also, zidovudine may be synthesized, i.e., manufactured, by the ex vivo (i.e., in vitro) enzymatic oxidation of the compound of formula (I) by the action of xanthine oxidase/dehydrogenase or aldehyde oxidase on the compound of formula (I). Oxygen or other appropriate electron acceptors such as ferricyanide ion or methylene blue may serve as the oxidizing agent. Microorganisms which contain or produce xanthine oxidase/dehydrogenase may be used to effect the conversion of the compound of formula (I) into zidovudine.
Thus, in a first aspect of the present invention, there is provided the compound of formula (I): ##STR1## wherein the azido group is in the erythro configuration, as shown. The chemical name for the compound of formula (I) is 1-(3-azido-2,3-dideoxy-β-D-erythro-pentofuranosyl)-5-methyl-2(1H)-pyrimidinone. Also provided are the 5'-esters of the compound of formula (I) and the pharmaceutically acceptable salts thereof as well as the pharmaceutically acceptable salts of the compound of formula (I), all of which are contemplated by the terms "compound of formula (I)" and "active ingredient" as hereinafter used.
5'-Esters include the mono-, di-, and triphosphate esters as well as carboxylic acid esters. Preferred carboxylic acid esters are those wherein the non-carbonyl moiety of the ester grouping is selected from straight or branched chain C 1-18 , preferably C 1-4 , alkyl or alkoxyalkyl, or phenyl.
Examples of pharmaceutically acceptable salts of the compound of formula (I) as a phosphate ester include base salts, e.g, derived from an appropriate base, such as alkali metal (e.g., sodium), alkaline earth metal (e.g., magnesium), ammonium and NX + 4 (wherein X is C 1-4 alkyl) salts. Examples of pharmaceutically acceptable salts of the compound of formula (I) in its unesterified form or as a carboxylic acid ester include, for example, acid addition salts of carboxylic acids such as acetic, lactic, propionic, benzoic, succinic, pivalic, acids, isethionic and methanesulfonic acids and mineral acids such as hydrochloric and sulfonic acids.
Accordingly, there is provided (a) the compound according to the invention for use in the treatment of retroviral or gram-negative bacterial infections and (b) use of the compound according to the invention in the manufacture of a medicament for the treatment or prophylaxis of a retroviral or gram-negative bacterial infection.
The compound of formula (I) also referred to herein as the active ingredient, may be administered for therapy by any suitable route including oral, rectal, nasal, topical (including transdermal buccal and sublingual), vaginal and parenteral (including subcutaneous, intramuscular, intravenous and intradermal). It will be appreciated that the preferred route will vary with the condition and age of the recipient and the nature of the infection.
In general a suitable systemic dose of the compound of formula (I) will be in the range of 4.0 to 160 mg per kilogram body weight of the recipient per day, preferably in the range of 8 to 120 mg per kilogram body weight per day and most preferably in the range 20 to 80 mg per kilogram body weight per day to generate zidovudine to treat the mammal, e.g., human, who has an HIV infection or gram negative bacterial infection. The desired dose is preferably presented as two, three, four, five, six or more sub-doses administered at appropriate intervals throughout the day. These sub-doses may be administered in unit dosage forms, for example, containing 10 to 1500 mg, preferably 20 to 1000 mg, and most preferably 50 to 700 mg of active ingredient per unit dosage form.
Suitable systemic methods of administering to a mammal, e.g., a human, the compound of formula (I) are orally or parenterally.
While it is possible for the compound of formula (I) to be administered systemically (internally) alone it is preferably to present it as a pharmaceutical formulation. The formulations of the present invention comprise the compound of formula (I) as above defined, together with one or more acceptable carriers thereof and optionally other therapeutic agents. Each carrier must be "acceptable" in the sense of being compatible with the other ingredients of the formulation and not injurious to the patient. Formulations include those suitable for oral, rectal, nasal, topical (including transdermal, buccal and sublingual), vaginal or parenteral (including subcutaneous, intramuscular, intravenous and intradermal) administration. The formulations may conveniently be presented in unit dosage form and may be prepared by any methods well known in the art of pharmacy. Such methods include the step of bringing into association of the compound of formula (I) with the carrier which constitutes one or more accessory ingredients. In general, the formulations are prepared by uniformly and intimately bringing into association the active ingredient with liquid carriers or finely divided solid carriers or both, and then if necessary shaping the product.
Formulations of the present invention suitable for oral administration may be presented as discrete units such as capsules, cachets or tablets each containing a predetermined amount of the compound of formula (I); as a powder or granules; as a solution or a suspension in an aqueous or non-aqueous liquid; or as an oil-in-water liquid emulsion or a water-in-oil liquid emulsion. The active ingredient may also be presented as a bolus, electuary or paste.
A tablet may be made by compression or molding, optionally with one or more accessory ingredients. Compressed tablets may be prepared by compressing in a suitable machine the compound of formula (I) in a free-flowing form such as a powder or granules, optionally mixed with a binder (e.g., povidone, gelatin, hydroxypropylmethylcellulose) lubricant, inert diluent, preservative, disintegrant (e.g., sodium starch glycollate, cross-linked povidone, cross-linked sodium carboxymethylcellulose) surface-active or dispersing agent. Molded tablets may be made by molding in a suitable machine a mixture of the powdered compound moistened with an inert liquid diluent. The tablets may optionally be coated or scored and may be formulated so as to provide slow or controlled release of the compound of formula (I) therein.
Formulations suitable for topical administration in the mouth include lozenges comprising the active ingredient in a flavored basis, usually sucrose and acacia or tragacanth; pastilles comprising the compound of formula (I) in an inert basis such as gelatin and glycerin, or sucrose and acacia; and mouthwashes comprising the active ingredient in a suitable liquid carrier.
Formulations for rectal administration may be presented as a suppository with a suitable base comprising, for example, cocoa butter or a salicylate.
Formulations suitable for vaginal administration may be presented as pessaries, tampons, creams, gels, pastes, foams or spray formulations containing in addition to the compound of formula (I) such carriers as are known in the art to be appropriate.
Formulations suitable for parenteral administration include aqueous and non-aqueous, isotonic, sterile, injection solutions which may contain anti-oxidants, buffers, bacteriostats and solutes which render the formulation isotonic with the blood of the intended recipient; and aqueous and non-aqueous sterile suspensions which may include suspending agents and thickening agents. The formulations may be presented in unit-dose or multi-dose sealed containers, for example, ampules and vials, and may be stored in a freeze-dried (lyophilized) condition requiring only the addition of the sterile liquid carrier, for example water for injections, immediately prior to use. Extemporaneous injection solutions and suspensions may be prepared from sterile powders, granules and tablets of the kind previously described.
Preferred unit dosage formulations are those containing a daily dose or unit, daily sub-dose, as herein above recited, or an appropriate fraction thereof, the compound of formula (I).
The compounds according to the invention may also be presented for use in the form of veterinary formulations, which may be prepared, for example, by methods that are conventional in the art. Examples of such veterinary formulations include those adapted for:
(a) oral administration, for example drenches (e.g., aqueous or non-aqueous solutions and suspensions); tablets or boluses; powders, granules or pellets for admixture with feed stuffs; pastes for application to the tongue;
(b) parenteral administration for example by subcutaneous, intramuscular or intravenous injection, e.g., as a sterile solution or suspension; or (when appropriate) by intrammammary injection where a suspension or solution is introduced into the udder via the teat;
(c) topical application, e.g., as a transdermal patch applied to the skin; or
(d) intravaginally, e.g., as a pessary, cream or foam.
It will be appreciated that such formulations as are described above will also be suitable for the presentation of combinations according to the invention, whether unitary or separate formulations, and may be prepared in a like manner.
It should be understood that in addition to the ingredients particularly mentioned above, the formulations of this invention may include other agents conventional in the art having regard to the type of formulation in question, for example, those suitable for oral administration may include such further agents as sweeteners, thickeners and flavoring agents.
The compound of formula (I), and its pharmaceutically acceptable derivatives, may be prepared in conventional manner using techniques that are well known in the art, e.g., as described in Synthetic Procedures in Nucleic Acid Chemistry (1, 321 (1968)), T. A. Krenitsky et al. (J. Med. Chem. (26, 981 (1983)); Nucleic Acid Chemistry, Improved and New Synthetic Processes, Methods and Techniques (Parts 1 and 2, Ed. L. D. Townsend, R. S. Tipson, (J. Wiley) 1978); J. R. Horwitz et al. (J. Org. Chem 29, (July 1964) 2076-78); M. Imazawa et al. (J. Med. Chem., 45, 3274 (1980)); and R. P. Glinski et al. (J. Chem. Soc. Chem. Commun., 915 (1970)).
The present invention further includes a process for the preparation of the compound of formula (I) which comprises:
(A) reacting a compound of formula (II) ##STR2## (wherein M represents a precursor group for the 3'-azido group) or a derivative (e.g., an ester) thereof, with an agent or under conditions serving to convert the said precursor group into the desired azido group;
(B) reacting a compound of formula (III) ##STR3## (wherein R represents a precursor group for a hydrogen atom) with an agent or under conditions serving to convert the said precursor group into the corresponding desired hydrogen atom; or
(C) reacting a compound of formula (IV) ##STR4## or a functional equivalent thereof, with a compound serving to introduce the desired ribofuranosyl ring at the 1-position of the compound of formula (IV);
and thereafter, or simultaneously therewith, effecting the following conversion:
when a derivative of a compound of formula (I) is formed, converting the said derivative into the parent compound of formula (I).
In the above-described process according to the invention, it will be appreciated that the choice of the precursor compounds in processes (A) to (C) will be dictated largely by the particular compound that it is desired to prepare, the above-mentioned agents and conditions being selected accordingly from those that are known in the art of nucleoside synthetic chemistry. Examples of such conversion procedures are described hereinafter for guidance and it will be understood that they can be modified in conventional manner depending on the desired compound. In particular, for example, where a conversion is described which would otherwise result in the undesired reaction of labile groups then such groups may be protected in conventional manner, with subsequent removal of the protecting groups after completion of the conversion.
Thus, for example, with regard to process (A) the group M in the compound of formula (II) may represent, for example, a halogen (e.g., chlorine), hydroxy or organosulphonyloxy (e.g., trifluoromethylsulphonyloxy, methanesulphonyloxy or p-toluenesulphonyloxy) radical.
For the preparation of the compound of formula (I), a compound of formula (II) in which the group M is a halogen (e.g., chloro) group in the threo configuration (in which the 5'-hydroxy is advantageously protected, e.g., with a trityl group) may be treated for example with lithium or sodium azide. The 3'-threo-halogen (e.g., chlorine) starting material may be obtained, for example, by reaction of the corresponding 3'-erythro-hydroxy compound with, for example, triphenylphosphine and carbon tetrachloride, or alternatively by treatment with organosulphonyl halide (e.g., trifluoromethanesulphonyl chloride) to form a corresponding 3'-erythro-organosulphonyloxy compound which is then halogenated, e.g., as described above. Alternatively a 3'-threo-hydroxy compound of formula (II) may be treated, for example with triphenylphosphine, carbon tetrabromide and lithium azide to form the corresponding 3'-erythro azido compound.
With regard to process (B) the following represents an example of various procedures by which the precursor group R in formula (III) may be converted into the desired H atom:
When R represents a 1,2,4-triazol-1-yl group, such compounds may be converted to the desired compound of formula (I) by treatment with hydrazine hydrate followed by treatment with silver oxide;
With regard to process (C), this may be effected for example by treating the appropriate pyrimidine of formula (IV) or a salt or protected derivative thereof, with a compound of formula ##STR5## (wherein Y represents a leaving group, e.g., an acetoxy or benzoyloxy or halo (e.g., chloro) moiety, and the 5'-hydroxyl group is optionally protected, e.g., by a p-toluyl, tert-butyldimethylsilyl or tert-butyldiphenylsilyl group), and subsequently removing any protecting groups.
The following Examples are intended for illustration only and are not intended to limit the scope of the invention in any way. The term `Active Ingredient` as used in the Examples means the compound of formula (I), i.e., 1-(3-azido-2,3-dideoxy-β-D-erythro-pentofuranosyl)-5-methyl-2(1H)-pyrimidinone.
EXAMPLE 1
Tablet Formulations
The following formulations A and B are prepared by wet granulation of the ingredients with a solution of povidone, followed by addition of magnesium stearate and compression.
______________________________________ mg/tablet mg/tablet______________________________________Formulation A(a) Active Ingredient 250 250(b) Lactose B.P. 210 26(c) Povidone B.P. 15 9(d) Sodium Starch Glycollate 20 12(e) Magnesium Stearate 5 3 500 300Formulation B(a) Active Ingredient 250 250(b) Lactose 150 --(c) Avicel pH 101 60 26(d) Povidone B.P. 15 9(e) Sodium Starch Glycollate 20 12(f) Magnesium Stearate 5 3 500 300Formulation CActive Ingredient 100Lactose 200Starch 50Povidone 5Magnesium stearate 4 359______________________________________
The following formulations, D and E, are prepared by direct compression of the admixed ingredients. The lactose used in formulation E is of the direct compression type (Dairy Crest- "Zeparox").
______________________________________ mg/capsule______________________________________Formulation DActive Ingredient 250Pregelatinized Starch NF15 150 400Formulation EActive Ingredient 250Lactose 150Avicel 100 500______________________________________
EXAMPLE 2
Capsule Formulations
Formulation A
A capsule formulation is prepared by admixing the ingredients of Formulation D in Example 1 above and filling into a two-part hard gelatin capsule. Formulation B (infra) is prepared in a similar manner.
______________________________________ mg/capsule______________________________________Formulation BActive Ingredient 250Lactose B.P. 143Sodium Starch Glycollate 25Magnesium Stearate 2 420Formulation CActive Ingredient 250Macrogol 4000 B.P. 350 600______________________________________
Capsules are prepared by melting the Macrogol 4000 B.P., dispersing the active ingredient in the melt and filling the melt into a two-part hard gelatin capsule.
______________________________________ mg/capsule______________________________________Formulation DActive Ingredient 250Lecithin 100Arachis Oil 100 450______________________________________
Capsules are prepared by dispersing the active ingredient in the lecithin and arachis oil and filling the dispersion into soft, elastic gelatin capsules.
EXAMPLE 3
Injectable Formulation
______________________________________Formulation A______________________________________Active Ingredient 0.200 gHydrochloric acid solution, 0.1M q.s. to pH 4.0 to 7.0Sodium hydroxide solution, 0.1M q.s. to pH 4.0 to 7.0Sterile water q.s. to 10 ml______________________________________
The active ingredient is dissolved in most of the water (35°-40° C.) and the pH adjusted to between 4.0 and 7.0 with the hydrochloric acid or the sodium hydroxide as appropriate. The batch was then made up to volume with the water and filtered through a sterile micropore filter into a sterile 10 ml amber glass vial (type 1) and sealed with sterile closures and overseals.
______________________________________Formulation B______________________________________Active Ingredient 0.125 gSterile, pyrogen-free, pH 7 phosphate buffer, q.s. to 25 ml______________________________________
EXAMPLE 4
Intramuscular injection
______________________________________ Weight (g)______________________________________Active Ingredient 0.20Benzyl alcohol 0.10Glycofurol 75 1.45Water for injection q.s. to 3.00 ml______________________________________
The active ingredient is dissolved in the glycofurol. The benzyl alcohol is then added and dissolved, and water added to 3 ml. The mixture is then filtered through a sterile micropore filter and sealed in sterile 3 ml amber glass vials (type 1).
EXAMPLE 5
Syrup
______________________________________Formula A Weight (g)______________________________________Active Ingredient 0.2500Sorbitol Solution 1.5000Glycerol 2.0000Sodium Benzoate 0.0050Flavor, Peach 17.42.3169 0.0125 mlPurified water q.s. to 5.0000 ml______________________________________
The active ingredient is dissolved in a mixture of the glycerol and most of the purified water. An aqueous solution of the sodium benzoate is then added to the solution, followed by addition of the sorbitol solution and finally the flavor. The volume is made up with purified water and mixed well.
______________________________________Formulation B Weight (g)______________________________________Active Ingredient 0.250Sorbitol Solution 1.500Glycerol 0.005Dispersible Cellulose 0.005Sodium Benzoate 0.010 mlFlavor q.s.Purified water, q.s. to 5.000 ml______________________________________
Mix the sorbitol solution, glycerol and part of the purified water. Dissolve the sodium benzoate in purified water and add the solution to the bulk. Add and disperse the dispersible cellulose and flavor. Add and disperse the active ingredient. Make up to volume with purified water.
EXAMPLE 6
3'-Azido-3'-deoxythymidine (AZT)
a) 2,3'-Anhydrothymidine
Thymidine (85.4 g: 0.353 mol) was dissolved in 500 mL dry DMF and added to N-(2-chloro-1,1,2-trifluoroethyl)diethylamine (100.3 g; 0.529 mol) (prepared according to the method of D.E. Ayer, J. Med. Chem. 6, 608 (1963)). This solution was heated at 70° C. for 30 minutes then poured into 950 mL ethanol (EtOH) with vigorous stirring. The product precipitated from this solution and was filtered. The EtOH supernatant was refrigerated then filtered to yield the title compound. mp. =230° C.
b) 3'-Azido-3'-deoxythymidine
2,3'-O-Anhydrothymidine (25 g: 0.115 mol) and NaN 3 (29 g, 0.446 mol) was suspended in a mixture of 250 mL DMF and 38 mL water. The reaction mixture was refluxed for 5 hours at which time it was poured into 1 liter of water. The aqueous solution was extracted with EtOAc (3×700 mL). The EtOAc extracts were dried over Na 2 SO 4 , filtered and the EtOAc was removed in vacuo to yield a viscous oil. This oil was stirred with 200 mL water providing the title compound as a solid which was collected by filtration. mp =116°-118° C.
EXAMPLE 7
5'-O-Acetyl-3'-azido-3'-deoxythymidine
To a solution of 3'-azido-3'-deoxythymidine (AZT) 20 g) in pyridine (50 mL) at ambient temperature, acetyl chloride (2.1 equivalents) was added. The reaction was stirred for two hours and kept at 0° at 5° C. for 20 hours. It was poured onto ice water with stirring. The aqueous phase was decanted. The oily product was dissolved in ethyl acetate and extracted with water (5 times), 0.5 N hydrochloric acid, water (2x), and dried over magnesium sulphate. The solution was filtered and evaporated in vacuo. The residual oil was dissolved in chloroform, applied to a silica gel column, and flash chromatographed using 2% methanol in chloroform. Fractions with product were evaporated and the oil was chromatographed again using ethyl acetate:hexane (6:4 v/v). Fractions with product were evaporated in vacuo to give 5'-O-acetyl-3'-azido-3'-deoxythymidine as a white solid.
m.p. 96°-98° C.
Calculated: C, 46.60; H, 4.89; N, 22.65.
Found: C, 46.67; H, 4.94; N, 22.59.
EXAMPLE 8
1-(5-O-Acetyl-3-azido-2,3-dideoxy-β-D-erythro-pentofuranosyl)-5-methyl-4-(1,2,4-triazol-1-yl)-2(1H)-pyrimidinone
5'-O-Acetyl-3'-azido-3'-deoxythymidine was reacted with 5 equivalents of 1,2,4-triazole and two equivalents of 4-chlorophenyl dichlorophosphate in dry pyridine at ambient temperature for 10 days. Silica gel chromatography of the crude product using 1:1 EtOAc/hexane (v/v) followed by combination and evaporation of the appropriate fractions yielded an oil. Crystallization from EtOAc afforded the title compound as a solid 2.7 g (7.5 mMol; 60%); m.p.=143°-145° C. UV (nm): at pH 1λ max =324,245,215 (ε=9300, 10000, 20500), λ min =282,233 (ε=2100,8200); at pH 13λ max =276 (ε=6000), λ min =242 (ε=2000), H 1 NMR (DMSO-d 6 ) δ9.34, 8.40(2s,2H, triazolyl), δ8.23(s,1H,H6), δ6.12(t, 1H, H1', J=6.16 Hz), β4.48-4.17(m, 4H, H3', H4', H5'), δ2.35(s, 3H, 5'-acetyl), δ2.07(s, 3H, 5CH3).
Analysis for C 14 H 16 N 8 O 4 .
Calculated: C, 46.67; H, 4.48; N, 31.10.
Found: C, 46.58; H, 4.51; N, 31.02.
EXAMPLE 9
1-(3-Azido-2,3-dideoxy-β-D-erythro-pentofuranosyl)-5-methyl-2-(1H)-pyrimidinone
1-(5-O-Acetyl-3-azido-2,3-dideoxy-β-D-erythro-pentofuranosyl)-5-methyl-4-(1,2,4-triazol-1-yl)-2-(1H)-pyrimidinone (0.5 g, 1.4 mMol) was dissolved in CH 3 CN (10 mL) and treated with 85% hydrazine hydrate (0.105 g, 2.1 mMol) for 30 minutes at ambient temperature, analogous to the procedure described in D. Cech and A. Holy, Coll. Czech. Chem. Comm. 42, 2246 (1977). The solvents were evaporated in vacuo and the residue chromatographed on silica gel with 9:1 CHCl 3 /MeOH (v/v) as the eluting solvent. Collection and evaporation of appropriate fractions yielded a solid. The solid was dissolved in EtOH (50 mL) containing Ag 2 O (0.35 g, 1.5 mMol, 1.5 eq) and refluxed for 90 minutes. Filtration of the hot suspension through a bed of celite followed by removal of solvents in vacuo gave a solid. The solid was chromatographed on silica gel and eluted with 20:1 CHCl 3 /MeOH (v/v). Combination and evaporation of appropriate fractions gave a solid which was dissolved in NH 3 -saturated MeOH (50 mL) for 3 hours. Evaporation of the solvents in vacuo yielded an oil which was chromatographed on silica gel eluted with 20:1 CHCl 3 /MeOH (v/v). The appropriate fractions were combined and solvents evaporated in vacuo to give an oil which slowly solidified upon standing: mp =62°-63° C.; UV (nm): at ph 1λ max =326, 212 (ε=7700, 13000), λ min =263(ε=200); at pH 13λ max 322,218(ε=22700, 10800), λ min =246 (ε=400); H'NMR: (DMSO-d 6 ) δ8.46(d, 1H, H 4 , J=3.28 Hz), 8.28(d, 1H, H 6 , J=3.23 Hz), 6.00(t, 1H, H1', J=5.08 Hz), 5.31(t, 1H, 5'OH, J=5.12 Hz), 4.4-4.3(m, 1H, H 3 '), 3.95-3.89(m, 1H, H 4 '), 3.8-3.6(m, 2H, H 5 '), 2.5-2.3(m, 2H, H 2 '), 2.03(s, 3H, 5-CH 3 ).
Analysis calculated for C 10 H 13 N 5 O 3 .0.25H 2 O: C, 46.96; H, 5.32; N, 27.38.
Found: C, 47.05; H, 5.40; N, 27.14.
EXAMPLE 10
1-(5-O-Acetyl-3-azido-2,3-dideoxy-β-D-erythro-pentofuranosyl)-5-methyl-2-(1H)-pyrimidinone
1-(5-O-Acetyl-3-azido-2,3-dideoxy-β-D-erythro-pentofuranosyl)-5-methyl-4-(1,2,4-triazol-1-yl)-2-(1H)-pyrimidinone (0.5 g, 1.4 mMol) was dissolved in CH 3 CN (10 mL) and treated with 85% hydrazine hydrate (0.105 g, 2.1 mMol) for 30 minutes at ambient temperature, analogous to the procedure described in (1). The solvents were evaporated in vacuo and the residue chromatographed on silica gel with 9:1 CHCl 3 /MeOH (v/v) as the eluting solvent. Collection and evaporation of appropriate fractions yielded a solid. The solid was dissolved in EtOH (50 mL) containing Ag 2 O (0.35 g, 1.5 mMol, 1.5 eq) and refluxed for 90 minutes. Filtration of the hot suspension through a bed of celite followed by removal of solvents in vacuo gave a solid. The solid was chromatographed on silica gel and eluted with 20:1 CHCl 3 /MeOH (v/v). Combination and evaporation of appropriate fractions gave the title compound as a golden oil: UV (nm): at pH 1λ max =327 (ε=6900), λ min =254 (ε=700); at pH 13λ max =322 (ε=17200), λ min =247 (ε=600); 1H NMR: (DMSO-d 6 ) δ8.46(d, J=3.13 Hz, 1H, H 4 ), 7.92(d, J=3.90 Hz, 1H, H 6 ), 6.03(dd, J=5.28 Hz, 6.64 Hz, 1H, H 1 ') 4.46-4.03(m, 4H, H 3 ', H 4 'H 5 '), 2.71-2.32(m, 2H, H 2 '), 2.05, 2.04(2s, 6H, 5-CH 3 , acetyl).
Analysis for C 12 H 15 N 5 O 4 :
Calculated: C, 49.14; H, 5.16, N, 23.88.
Found: C, 49.39; H, 5.22; N, 23.75.
(1) D. Cech and A. Holy, Coll. Czech. Chem. Comm. 42, 2246 (1977).
EXAMPLE 11
1-(3-Azido-2,3-dideoxy-5-O-pivaloyl-β-D-erythro-pentofuranosyl)-5-methyl-2(1H)-pyrimidinone
1-(3-Azido-2,3-dideoxy-β-D-erythro-pentofuranosyl)-5-methyl-2(1H)-pyrimidinone (0.4 g, 1.59 mMol) was dissolved in dry pyridine (10 mL) at 0° C. under a nitrogen atmosphere. Pivaloyl chloride (0.588 mL; 4.78 mMol) was added with stirring and allowed to react for 72 hours. The reaction was quenched with ice then evaporated to dryness. The residue was chromatographed on silica gel eluted with 20:1 CHCl 3 /MeOH (v/v) and the appropriate fractions combined and evaporated to give the title compound: mp =121°-123° C.; UV (nm): at pH 1λ max =327 (ε=5900), λ min =269 (ε=820); at pH 13λ max =322 (ε=17200), λ min =251 (ε=850); 1H NMR: (DMSO-d 6 ) δ8.48(d, J=3.12 Hz, 1H, H 4 ), 7.88(d, J=3.27 Hz, 1H, H 6 ), 6.02(t, J=6.25 Hz, 1H, H 1 '), 4.48-4.39(m, 1H, H 3 '), 4.31-4.28(m, 2H, H 5 '), 4.20-4.14(m, 1H, H 4 '), 2.62-2.50(m, 1H, H 2 '), 2.41-2.27(m, 1H, H 2 '), 2.04(s, 3H, 5-CH 3 ), 1.12(s, 9H, -C(CH 3 ) 3 ).
Analysis for C 15 H 2 1N 5 O 4 .01H 2 O.
Calculated: C, 53.43; H, 6.34, N, 20.77.
Found: C, 53.46, H, 6.36, N, 20.72.
EXAMPLE 12
1-[3-Azido-5-O-(3-chlorobenzoyl)-2,3-dideoxy-β-D-erythropentofuranosyl]-5-methyl-2(1H)-pyrimidinone
The title compound was prepared from 3-chlorobenzoyl chloride in a manner analogous to the pivaloyl ester to yield a clear gum: UV (nm) pH 1λ max =327 (ε=6200), λ min =264 (ε=1700); pH 13λ max =318 (ε=8500), λ min =257 (ε=1600); 1H NMR: (DMSO-d 6 ) δ8.43(d, J=1.27 Hz, 1H, H 4 ), 7.93-7.52(m, 5H, H 6 , benzoyl), 6.06(t, J=5.28 Hz, 1H, H 1 '), 4.67-4.51(m, 3H, H 3 ', H 5 '), 4.30(q, J=4.25 Hz, 1H, H 4 '), 2.59-2.39(m, 2H, H 2 '), 1.85(s, 3H, 5-CH 3 ).
Analysis for C 17 H 16 N 5 O 4 Cl:
Calculated: C, 52.38, H, 4.14, N, 17.97.
Found: C, 52.52, H, 4.19, N, 17.82.
EXAMPLE 13
1-(3-Azido-2,3-dideoxy-5-O-hexadecanoyl-β-D-erythro-pentofuranosyl)-5-methyl-2(1H)-pyrimidinone
1-(3-Azido-2,3-dideoxy-β-D-erythro-pentofuranosyl)-5-methyl-2(1H)-pyrimidinone (0.25 g, 1 mMol) was dissolved in 11 mL anhydrous pyridine at 0° C. under a nitrogen atmosphere. Freshly distilled palmitoyl chloride (2.5 mL) was added all at once and the reaction stirred for 2 hrs. The solvents were evaporated away and the residue applied to a silica gel column eluted with 1:6 EtOAc/hexane (v/v). Appropriate fractions were combined and evaporated to give the title compound 0.14 g (0.29 mMol; 29%); mp =65°-67° C.; UV (nm) EtOH: λ max =228 (ε=13400), λ min =212 (ε=10300); 1H NMR (DMSO-d 6 ) δ7.03(d, J=1.37 Hz, 1H, H 6 ), 5.90(dd, J=1.76 Hz, 6.45 Hz, 1H, H 1 '), 5.34(s, 1H, H 4 ), 4.50(s, 1H, H 3 '), 4.30-4.24(m, 1H, H 4 '), 3.93-3.70(m, 2H, H 5 '), 2.91(t, J=12.7 Hz, 2H, --C(O)CH 2 -- ), 2.57-2.26(m, 2H, H 2 '), 1.73(s, 3H, 5-CH 3 ), 1.54-0.80(m, 29 H, palmitoyl).
Analysis for C 26 H 43 N 5 O 4 .0.05C 16 H 32 O 2 .
Calculated: C, 64.06, H, 8.95, N, 13.94.
Found: C, 64.28, H, 8.92, N, 13.93. | A compound 1-(3-azido-2,3-dideoxy-β-D-erythro-pentofuranoxyl)-5-methyl-2(1H)-pyrimidinone and its use in a method of generating (forming, providing) 3'-azido-3'-deoxythymidine (zidovudine sometimes referred to as AZT) in the body of an animal (a mammal such as human) by systemically administering 1-(3-azido-2,3-dideoxy-β-D-erythro-pentofuranosyl)-5-methyl-2(1H)-pyriminone to said animal (mammal such as a human) is disclosed. AZT is approved and used for treating HIV infections, e.g., AIDS and ARC in humans and also has activity against gram-negative bacteria in animals. | 2 |
FIELD OF THE INVENTION
The present invention is directed toward an electronic assembly with a removable midplane, and more specifically, toward an electronic assembly comprising a chassis for supporting a plurality of electronic components and a modular removable midplane electrically connectable to electronic components supported by the chassis.
BACKGROUND OF THE INVENTION
Assemblies for supporting a plurality of electrical components and connecting them to various power supplies, inputs, outputs and/or to one another are well known. The electrical components are often modular and can be individually connected to and removed from the assembly. Such assemblies may be referred to, for example, as electrical cabinets or racks and generally comprise a structural frame or chassis that supports the electrical components. The assembly may be at least partially surrounded by a housing to protect the electrical components.
The housing, in some instances, may comprise individual panels secured to the chassis. In other cases, a housing may include structural supports integrated therewith and lack a distinct chassis. As used herein, “chassis” will generally refer to structural elements of an electronic assembly and “housing” will refer to elements provided primarily for protecting or covering the electronic modules whether these elements are separately provided or integrally formed.
It is also known to provide such assemblies with a midplane. A midplane is frequently a printed circuit board (PCB) having a plurality of connectors connectable to the electronic modules supported by the assembly. A midplane is generally provided toward the middle of an assembly and often includes electrical connectors on front and rear surfaces thereof so that modules can be connected to both sides.
Typical assemblies include a chassis that is constructed around a midplane, which essentially makes the midplane an integral part of the chassis. This is especially true in the case of “dual bay” or “multi-bay” assemblies which are arranged to support multiple levels of electronic modules stacked vertically and thus have at least two bays on their front and rear sides. If a midplane requires repair or if an upgrade to the midplane is needed, the chassis must be disassembled to a significant degree to access the midplane. This is often difficult to do at a site where the assembly is installed because it may be difficult or impossible to properly realign the midplane with the chassis when it is reinstalled in the assembly. Moreover, employees or contractors skilled in assembling sheet metal chassis may not be adept at handling printed circuit boards, and a printed circuit board may be damaged when a chassis is assembled around it. Electrostatic discharge, for example, can damage the PCB if care is not taken during chassis assembly.
It would therefore be desirable to provide an electrical assembly to which a midplane may be added after chassis assembly is complete and which allows for the easy removal and replacement of a midplane.
BRIEF DESCRIPTION OF THE DRAWINGS
Various aspects of the invention will become apparent after a reading of the following detailed description of the invention in connection with the following drawings wherein:
FIG. 1 is a perspective view of a chassis for an assembly according to an embodiment of the present invention;
FIG. 2 is a partially exploded perspective view of an assembly including the chassis of FIG. 1 , a midplane, and a housing;
FIG. 3 is a perspective view of the assembly of FIG. 2 including a plurality of electronic modules mounted in bays of the assembly;
FIG. 4 is a rear elevational view of the midplane of FIG. 2 ;
FIG. 5 is a side elevational view of the midplane of FIG. 2 ;
FIG. 6 is a side elevational view, partly in section, of the assembly of FIG. 2 ;
FIG. 7 is a sectional view taken along line VII—VII of FIG. 3 illustrating a first midplane mounting arrangement;
FIG. 8 is a sectional front elevational view of an assembly according to an embodiment of the present invention illustrating a first alternate midplane mounting arrangement;
FIG. 9 is a sectional front elevational view of an assembly according to an embodiment of the present invention illustrating a third alternate midplane mounting arrangement;
FIG. 10 is a side elevational view of an assembly according to a second embodiment of the present invention; and
FIG. 11 is a flow chart illustrating a method of assembling an electrical assembly according to an aspect of the present invention.
DETAILED DESCRIPTION
Referring now to the drawings, wherein the showings are for purposes of illustrating preferred embodiments of the invention only and not for the purpose of limiting same, FIG. 1 illustrates a chassis 10 formed from a plurality of vertical framing members 12 and horizontal framing members 14 interconnected to form an enclosure in the shape of a rectangular parallelepiped having a front 16 , a rear 18 , a first side 19 and a second side 20 . Chassis 10 also includes guide plates for guiding and supporting a number of electronics modules 21 (illustrated in FIG. 3 ) including a lower front guide plate 22 having a flange 23 and a lower rear guide plate 24 having a flange 25 and four middle guide plates, namely, a first side front guide plate 26 having a flange 27 , a second side front guide plate 28 having a flange 29 , a first side rear guide plate 30 having a flange 31 and second side rear guide plate 32 having a flange 33 . A first gap 34 extending from first side 19 of chassis 10 to second side 20 of chassis 10 is defined by the pair of middle front guide plates 26 , 28 and middle rear guide plates 30 , 32 for receiving a midplane 36 illustrated, for example in FIG. 2 . A second gap 35 running from front 16 of chassis 10 toward rear 18 of chassis 10 is defined by first side guide plates 26 , 30 and second side guide plates 28 , 32 and may be used to accommodate an added guide plate 43 as illustrated in FIGS. 2 and 3 .
In this embodiment, an end plate 38 is provided on first side 19 of chassis 10 at one end of gap 34 and a frame plate 40 is provided on second side 20 of chassis 10 on the end of gap 34 opposite end plate 38 . A U-shaped channel support 41 is mounted beneath lower guide plates 22 and 24 and helps guide and support midplane 36 as described hereinafter. Upper guide plates 37 , 37 ′ having flanges 39 , 39 ′ further define slot 34 . While guide plates 37 , 37 ′ are illustrated as solid plates, they may alternately be formed with vents such as those formed in lower guide plates 22 , 24 and middle guide plates 26 , 28 , 30 , 32 .
It should be noted that while a multi-bay assembly having two bays, upper and lower bays 72 , on each side is illustrated, an assembly having three or more levels of bays could also be provided. Moreover, the size of the bays is determined by the size of the various electronic modules 21 to be mounted therein, and could differ from what is shown. In addition, while the middle front guide plates 26 , 28 and middle rear guide plates 30 , 32 (and lower front guide plate 22 and lower rear guide plate 24 ) are illustrated as lying in substantially the same plane, they could just as readily lie in different planes.
FIGS. 2 and 3 illustrate a housing 42 attached to chassis 10 . Housing 42 comprises a top panel 44 , a first side panel 46 on first side 19 of chassis 10 , and a second side panel 48 on the second side 20 of chassis 10 . Second side panel 48 includes an opening 50 aligned with frame plate 40 of chassis 10 through which midplane 36 can be inserted into and removed from chassis 10 . Housing 42 provides protection for components 21 and may also contribute to the rigidity of the overall assembly. Various openings are provided in housing 42 for cooling and wiring connections in a well known manner.
Midplane 36 comprises a PCB that includes a front side 52 , illustrated in FIG. 3 , and a rear side 54 illustrated in FIG. 5 . Midplane 36 further comprises an upper edge 56 , a lower edge 58 , a first side edge 60 and a second side edge 62 . A plurality of connectors 64 are provided on front side 52 and rear side 54 , the size, type and wiring of which will depend on the types of electronic modules 21 to be used in the assembly. As illustrated in FIGS. 4 and 5 , midplane 36 further includes first and second braces or stiffeners 66 running between first side edge 60 and second side edge 62 which are formed from a material such as steel, for example, and are designed to increase the rigidity of midplane 36 .
As will be appreciated from FIGS. 1 and 2 , midplane 36 can be inserted into chassis 10 through opening 50 in second side panel 48 of the housing and through frame plate 40 of the chassis 10 through gap 34 between front guide plates 26 , 28 and rear guide plates 30 , 32 until first side edge 60 of midplane 36 abuts end plate 38 of chassis 10 . Lower edge 58 of midplane 36 is supported by support 41 while the middle guide plate flanges 27 , 29 , 31 and 33 and flanges 39 , 39 ′ on upper guide plate 37 help guide the midplane along slot 34 .
With regard to FIGS. 1 and 7 , in this embodiment, end plate 38 includes a plurality of projections 68 which will help to properly align midplane 36 with respect to chassis 10 . These projections 68 may comprise pins secured to end plate 38 or screws or other fasteners inserted through openings formed in end plate 38 . In a presently preferred embodiment, a combination of alignment pins and screws is used. The specific nature of the alignment mechanism is not critical so long as projections are provided that can be received into alignment openings 70 formed at opposite ends of stiffeners 66 .
The alignment openings 70 and projections 68 are arranged and configured so that midplane 36 will assume a predetermined relationship to guide plates 26 , 28 , 30 and 32 , and hence any electrical modules 21 supported by those guide plates, when electrical modules are inserted into the bays 72 defined by the chassis 10 , guide plates 26 , 28 , 30 and 32 , and any auxiliary dividers 74 as illustrated in FIGS. 2 and 6 . Additional fasteners 73 extend through openings 75 in the flange 23 of lower guide plate 22 , though openings 75 in flanges 27 and 29 of middle front guide plates 26 and 28 , and through flange 39 ′ of upper guide plate 37 ′ into openings (not shown) in midplane 36 to further secure midplane 36 to the chassis. Additional fasteners 73 are also provided in the flange 25 of lower rear guide plate 24 and in the flanges 31 , 33 of middle rear guide plates 30 , 32 and in flange 39 of upper guide plate 37 to further align and secure midplane 36 .
To accommodate variations in the thickness of midplane 36 , slot 34 will generally be slightly wider than the nominal thickness of midplane 36 . Therefore, the midplane will be rigidly fastened to only one set of flanges, such as rear flanges 25 , 31 , 33 , 39 . Fasteners 73 extending through front flanges 23 , 27 , 29 and 39 ′ will extend into openings in the midplane to help hold the midplane in proper position, but the midplane will generally be slightly spaced from these front flanges.
With projections 68 inserted into the alignment openings 70 near first side edge 60 of midplane 36 , alignment openings 70 near second side edge 62 of midplane 36 remain exposed through opening 50 in second side panel 48 . An access panel 76 is provided that is sized to cover opening 50 and attach to second side panel 48 and/or frame plate 40 . Access panel 76 includes an EMI gasket 77 to provide an EMI seal around opening 50 , and openings 78 aligned with alignment openings 70 near second side edge 62 of midplane 36 . Suitable fasteners 80 , such as pins or screws are inserted through openings 78 and into alignment openings 70 of midplane 36 . When access panel 76 is then secured to housing 42 , midplane 36 will be secured in a proper orientation with respect to the chassis 10 . Because midplane 36 is locked in place in this manner, it not only maintains a necessary orientation with respect to the chassis 10 and supported electronic elements 21 , but it, together with stiffeners 66 , braces and contributes to the rigidity of chassis 10 . As will appreciated from the foregoing, this arrangement simplifies the removal and repair or replacement of midplane 36 as well.
In a variation of the above embodiment, end plate 38 can be omitted and projections 68 may be supported by first side panel 46 of housing 42 . Likewise, frame plate 40 can be omitted and the access panel 76 may be connected directly to second side panel 48 of housing 42 .
An additional variation of this embodiment of the invention is illustrated in FIG. 8 . Elements identical to those in the first variation are identified with like reference numerals. In this embodiment, a guide channel 80 is provided on end plane 38 (or directly mounted on housing first side panel 46 ), and first side edge 60 of midplane 36 is inserted into this guide channel 80 to hold the midplane 36 in proper orientation with respect to chassis 10 . Access panel 76 is also provided with a guide channel 82 which is placed over second side edge 62 of midplane 36 as access panel 76 is secured to housing 42 . Guide channel 80 and access panel guide channel 82 hold midplane 36 securely in place within chassis 10 this secure interconnection allows midplane 36 to increase the rigidity of chassis 10 .
FIG. 9 illustrates an alternate variation of the invention in which elements common to the earlier variations are identified with the same reference numerals; elements related to previously identified elements are identified with the same reference numeral and a prime. In this embodiment, end plate 38 (or first side panel 46 of housing 42 ) is provided with openings 84 that receive projections 86 of stiffeners 66 ′. Openings 88 on access panel 76 ′ receive projections 86 near the second side edge 62 of midplane 36 . Projections 86 and openings 84 , 88 are arranged such that midplane 36 is properly positioned within chassis 10 when the projections are received within the openings and access panel 76 is secured to housing 42 .
FIG. 10 illustrates a second embodiment of the present invention in which elements common to the earlier embodiments are identified with like reference numerals. In this embodiment, chassis 10 is open and not covered with panels forming a housing as in the first embodiment. A lower bracket 90 is provided on lower guide plate 24 while an upper bracket 92 is provided between two of the horizontal framing members 12 forming chassis 10 . Lower bracket 90 and upper bracket 92 define, with gap 34 , an opening into which a midplane 36 can be inserted into chassis 10 . A first member, such as plate 96 is removably connected between second side front guide plate 28 and second side rear guide plate 32 and a second member, such as plate 98 is removably connected to lower guide plate 24 to hold midplane 36 in place. The end of gap 34 at first side 19 of chassis 10 may be blocked by a portion of one of the horizontal framing members 14 that form chassis 10 or by an additional plate 96 . This arrangement allows the benefits of embodiments of the present invention to be enjoyed even in rack arrangements with an open chassis.
A method of practicing an embodiment of the present invention is illustrated in the flow chart of FIG. 11 . In a first step 100 , a chassis is formed for supporting a plurality of electronic elements. A housing comprising at least one panel having an opening is attached to the chassis at a step 102 . At a step 104 , a midplane is slid through the opening into the chassis, and at a step 106 , a cover is attached over the opening to hold the midplane in a predetermined position with respect to the chassis.
The present invention has been described herein in terms of several embodiments. Numerous modifications and additions to these embodiments will become apparent to those skilled in the relevant arts upon a reading and understanding of the foregoing description. It is intended that all such modifications and additions form a part of the present invention to the extent they fall within the scope of the several claims appended hereto. | A modular electronic assembly includes a chassis, a housing supported by the chassis having an access opening through a first wall of the housing, a removable access panel or releasable member at least partially covering the opening, and a midplane supported by the chassis and slidably removable from the chassis through the opening when the housing is mounted on the chassis. A method of constructing a modular electronic assembly is also disclosed. | 7 |
BACKGROUND AND BRIEF DESCRIPTION OF PRIOR ART
Spread spectrum communications is presently being used for a number of commercial applications and is expected to proliferate as the demand for untethered communications increases.
A number of consortiums have been formed to develop satellite based Personal Communications Systems (PCS) with global coverage. Some examples of these systems include Globalstar (Globalstar System Application before the FCC by Loral Cellular Systems, Corp., Jun. 3, 1991) and Odyssey (Application of TRW Inc. before the FCC to Construct a New Communications Satellite System "Odyssey," May 31, 1991), among others. The intent of these systems is that a subscriber can place telephone calls directly through the satellite network from almost anywhere on the Earth, using a portable handset much like the present cellular telephones. Both of the systems mentioned intend to use spread spectrum CDMA techniques for a number of reasons.
The return link signal, as proposed in the above filings, is direct sequence (DS) CDMA spread spectrum. This type of signaling, while having some desirable characteristics, suffers from a number of disadvantages for satellite PCS application. Among these are the difficulty of rapid acquisition, the sensitivity of system capacity to power control error, and the Eb/No degradation due to access noise (these systems typically require Eb/No>8 dB at BER=0.001 in order to achieve reasonable user capacities).
OBJECTS OF THE INVENTION
The invention serves several functions. These are summarized as:
Provide a robust return link that is readily acquired and synchronized.
Provide a return link signal that is very power efficient.
Provide a return link that is essentially free of access noise.
Provide a return link operation that is very insensitive to power control errors.
Provide a return link that has very high user capacity.
Provide means for readily accessing a CDMA network on a noninterfering basis without prior time and frequency synchronism.
Allows the hub station to detect and synchronize the user before assigning him a traffic channel.
Provides the user with a high link margin in-band channel for net entry requests.
SUMMARY OF THE INVENTION
The hub station of a satellite communication network receives a multiplicity of spread spectrum signals from the subscriber terminals. Each of these signals (on a particular frequency channel) is composed of data symbols which are transmitted via a FH carrier. These signals are synchronized to arrive at the hub station in time and frequency synchronism. The signal carriers employ orthogonal hopping patterns, i.e. none of the signals occupies the same frequency bin at the same time. The orthogonal properties of the signals allow them to be demodulated without access noise from co-channel signals. This is called orthogonal frequency hopping (OFH). Nonsynchronous users on this channel cannot be demodulated by the ground station due to the high level of access noise for a nonorthogonal user. A separate in-band Net Entry Channel (NEC) is provided for initial synchronism of users. Spread spectrum signals on this channel can be received by the hub station free of access noise from the traffic channels. Further, the NEC signals do not interfere with the traffic channel users despite initial timing and frequency errors. The return link signals are maintained in synchronism by transmitting small time and frequency corrections to each user from the GS via the inband control data on the outbound signal. The correction gain and update rate may be different for each user and may even be adaptive if user dynamics vary widely. Efficient data demodulation is performed despite phase discontinuities at the hop transitions by the use of block frequency and phase estimation techniques (i.e. feed-forward estimation is used as opposed to a phase-locked loop which has unpredictable acquisition times due to the loop nonlinearities). The decoder operates efficiently despite phase discontinuities at the hop transitions through a novel arrangement of parallel decoders as described below. The use of slow hopping can result in signals that are received at two different satellites being perceived as orthogonal signal sets although they are synchronized for a single satellite. The ground station GS can determine the necessary time and frequency corrections that the new user must employ in order to enter the network in synchronism. This is performed on the net entry channel NEC and is necessary to establish user-GS communications on the traffic channel. The NEC provides a means for the user to transmit a net entry request with high probability of success using the time and frequency information derived by tracking the outbound signal. The use of a lower hop rate on the NEC (than on the traffic channels) allows rapid acquisition of the PN signal despite timing uncertainties.
DESCRIPTION OF THE DRAWINGS
The above and other objects, advantages, and features of the invention will become more apparent when considered with the following specification and accompanying drawings wherein:
FIG. 1 is a schematic block diagram of the system architecture incorporating the invention,
FIG. 2 is a diagrammatic illustration of the signalling subband showing six network entry channels (NEC) frequency bins,
FIG. 3 is a functional block diagram of the subscriber unit return link transmitter, and
FIG. 4 is a functional block diagram of a ground station return link receiver.
DETAILED DESCRIPTION OF THE INVENTION
In order to describe the invention in detail, the embodiment will be discussed as it applies to the return link of a star configured spread spectrum satellite network. The forward communications link 10 includes user signals transmitted from a hub ground station (GS) 12 through a satellite 11 which transponds them to individual users on the ground. The system will typically employ a multibeam antenna 13 which illuminates contiguous "cells" on earth.
The hub ground station 12 includes antenna means 15 broadcasting the forward link signals 10 (which include the net entry control channel) from a plurality of control channel signal generators 16-1, 16-2 . . . 16-N to the satellite which transponds the signals to a cell on earth where the destination handset 14 is located. Hub ground station 12 also includes a plurality of return link receivers 17-1, 17-2 . . . 17-N (the details of which are shown in FIG. 4), which are coupled to a system controller 18 to provide time, frequency and power correction signals to the control channel generator and the forward link 10. The circuits for providing time, frequency and power correction are illustrated in the functional block diagram of FIG. 4.
Each subscriber station 14 includes a control channel receiver 19 which provides the time, frequency and power correction signal from the hub ground station to the subscriber unit return link transmitter 20) which is shown in detail in the functional block diagram of FIG. 3).
In the disclosed embodiment, the forward link signals 10 are assumed to be spread spectrum orthogonal CDMA (OCDMA) in nature, and occupying approximately 2.5 MHz. It is further assumed, for illustrative purposes, that as many as 256 CDMA signals may occupy one of the 2.5 MHz subbands. One or more of these CDMA signals is used by the GS as a "Control Channel" for communication with subscriber handsets (HS) 14 for call set up and network synchronization purposes. It is further assumed that each outbound signal contains in-band control data by which the GS 12 can send synchronization and power control data to the HS while the HS is in active conversation. The system may employ several of the 2.5 MHz subbands.
The GS 12 transmits in several subbands which are "stacked" into an appropriate bandwidth for transmission on the uplink to the satellite. Groups of subbands are then routed to different antenna beams or antennas 13 on the satellite for transmission to individual users on the ground.
Note that the invention disclosed herein refers primarily to the return link 15 and does not depend on the structure of the outbound link except as regards the presence of a control channel.
RETURN LINK SIGNAL DESCRIPTION
The fundamental purpose of the return link 15 is to transmit data from the user handset HS 14 to the ground station GS 12. The data transmission rate will be taken to be 4800 bps for illustrative purposes. A summary of signal parameters for this illustrative embodiment are shown in Table 1.
TABLE 1______________________________________Summary of example signal parameters for preferred embodiment. PARAMETERITEM VALUE COMMENTS______________________________________Spreading Technique Orthogonal FH No access noiseHop Rate 150 HPS 3 hops per 20 ms frameHop Bandwidth 1.25 MHzHop Bin Spacing 9900 Hz 126 bins in 1.25 MHzData Modulation OQPSK bandwidth efficientData Rate 4800 BPSCoding Rate 1/2Channel Rate 4950 SPS 1 symbol guard time between hopsEb/No for BER = 4 dB At least 4 dB better than.001 nonsynchronous CDMAUsers links in 2.5 228MHz______________________________________
The return link 15 employs Orthogonal FH (OFH) over a 1.25 MHz subband. Hop bins are spaced by 9900 Hz and there are 126 bins in the subband, accommodating a maximum of 126 orthogonal signals.
The hop rate is 150 HPS, giving a hop period of 6.7 ms. All signals in the subband are received in synchronism at the GS. This is achieved by closing "long" time and frequency tracking loops through the GS by way of the outbound signal control channel.
The hop bins to be used for traffic signaling are numbered from 0 to 113 (the 12 additional bins are used for network entry as discussed below). All subscribers in a frequency subband use the same hop code sequence (h1, h2, . . . hk . . . hK). The user is assigned a Traffic Channel Number (TCN) from 0 to 113. The user adds the TCN to the hop code sequence Mod (114) to determine the transmit hop bin sequence.
Modulation is OQPSK which is bandwidth efficient, power efficient, and relatively tolerant of amplifier nonlinearities. The data is encoded with a R=1/2 convolutional encoder. The channel transmission rate is 4950 SPS which allows one symbol guard time between hops. There are 33 symbols per hop of which 32 are data symbols. The data is detected using quasi-coherent block phase and frequency estimation techniques.
The Viterbi decoder is implemented in a novel fashion to operate in the presence of a phase discontinuity at the hop transition. To explain this technique, let us assume that a Viterbi decoder has been successfully decoding the data up to the beginning of the present hop. The 32 bits of this hop are demodulated as soft decision symbols, however with a phase ambiguity of ninety degree multiples due to the phase discontinuity at the hop transition and ambiguity of the carrier phase estimator. We now form three other versions of the demodulated data corresponding to 90, 180, and 270 degree rotations of the carrier phase reference. Each of these sets of data is decoded by an independent decoder (total of four), each of which has been initialized to the state of the decoder which successfully decoded the data from the last hop. After the decoding, the branch metrics of the four decoders are checked to find which decoder is most likely correct. The other three decoders are then set to the same state as the successful decoder and this procedure repeated for the next hop.
At start-up, or after a system outage due to fading, the decoding device will resolve the initial phase ambiguity after a few hops (as long as the hop period is at least a few decoder constraint lengths long). This relationship will then be maintained by the decoder device. This system may be used with either transparent or non-transparent codes.
A second novel way to implement the Viterbi decoder operation in the presence of a phase discontinuity at the hop transition is as follows. Because the signal is OQPSK, the phase transitions on the two signal quadratures occur with a time offset of one half symbol. A device which synchronizes to the phase transitions on the received signal can then identify whether the transitions agree with the prior hop or whether there is a 90° rotation. If there is a 90° rotation, this is accounted for by swapping the data on the two signal quadratures. This leaves either a properly aligned signal in phase, or a 180° error. Similar to the above, multiple decoders are used, but now two rather than four are used. All other discussion of the prior paragraph applies to the two decoders, other than the last step where one (rather than three) decoders is set to the same state as the successful decoder.
Both approaches for implementing the Viterbi decoder operation in the presence of a phase discontinuity at the hop transition are applicable to a broad set of applications for burst signals. These include any communication system using any form of phase-shift-keyed modulation (e.g., OQPSK, QPSK, BPSK, multi-level PSK, QASM) where the signals occur in bursts, for the first approach and OQPSK only for the second approach. These include, but are not limited to, Time Division Multiple Access, pocket switching, polled networks. These systems may or may not be spread spectrum. These communication system include but are not limited to satellite, terrestrial cellular, terrestrial radio local area networks, and in-building local area networks.
Slow Hopping
An important feature of this invention is when multiple satellites are to receive and relay the same signal for multi-satellite diversity, either switched or combining. Then by using a slow hop rate in the vicinity of, but not limited to, 1-20 hops/sec, the signals are, in a practical case, non-interfering. Consider the user links to be synchronized and operating through a satellite. All of the signals arrive at the satellite with the same timing and do not interfere with each other (they are orthogonal). When these same signals are seen at a second satellite, their relative timing is different and they interfere with one another, during the time they overlap due to relative timing offsets resulting from different locations on the earth.
By using a slow hopping rate, say 10 hop/second, the hop dwell time is longer (100 ms vs. 6.7 ms for the 150 HPS example). Thus, the fraction of the hop dwell which is corrupted by a 5 ms overlap, for example, is much smaller. The remaining (central) portion of each dwell, which may be in excess of 90% of each hop dwell time may be used for communications with no interference. During the overlap time, the signals could be left on with a synchronization pattern at each end to provide robust synchronization. The overlap sections at each end will not both totally be interfered with. One or the other or portions of both synchronization sections will always be observable and usable. Alternatively, the signals could be turned off in the overlap sections to conserve power to the transmitter.
Return Link Network Entry Channel (NEC)
The return link described above depends on all user HS signals arriving in time and frequency synchronism to remain orthogonal. Once a HS is in the network, synchronism is maintained by detecting small time and frequency errors for each user signal at the GS and sending corrections by way of the in-band control data on the outbound signal. However, initial entry of a HS into the network to place or answer a call is a problem since the HS does not have adequate information to transmit a signal which will arrive at the GS in synchronism with other traffic signals.
This problem is partially mitigated by assuming that the GS compensates the outbound signal to remove the satellite Doppler for users in the center of the antenna beam. The user HS acquires the outbound signal and monitors the control channel before using the NEC. Thus, the HS can use the outbound signal as a time and frequency reference, however a time and frequency error will occur if the HS is off beam center. This initial uncertainty is taken to be ΔT=±6 ms, ΔF=±8 KHz for the present explanation.
The NEC employs OFH over six frequency hop slots 25-1, 25-2 . . . 256-6 that are uniformly spaced over the 1.25 MHz traffic subband as shown in FIG. 2. Each hop slot 25 is 19.8 KHz wide (two contiguous 9.9 KHz traffic hop bins).
The hop rate is 37.5 Hz (150/4), and the transmit frequency starts at 1 KHz above the nominal bin center frequency and is stepped to 1 KHz below the center frequency at the middle of the hop. This transition is used for time tracking. The NEC signal parameters are summarized in Table 2.
TABLE 2______________________________________NEC signal parameter summary.ITEM VALUE COMMENTS______________________________________Hop Rate 37.5 HPS T.sub.H = 26.7 ms compared to initial ΔT = ± 6 msHop Bin Width 19.8 KHz Initial ΔF = ±8 KHzNumber of 6 Spaced over 1.25 MHzHop BinsModulation 2 KHz frequency Provides a transition for time step at hop center sync______________________________________
The hop code is formed in a similar manner to that for the traffic channels, i.e. six orthogonal hop frequency sequences are generated by adding the NEC number to a hop code sequence.
The NEC is used by the subscriber to place or answer a call. In order to use the NEC, the user HS must have acquired the outbound signal and be monitoring the control channel. Identifiers for unoccupied NEC codes are transmitted to the HS on the control channel. There are a total of 6 codes. The HS selects one of the unoccupied NEC codes and begins to transmit using frequency and time corrections based on the outbound signal.
The GS 14 performs a fast fourier transform FFT (FIG. 4) centered on each of the NEC frequency bins and:
1) Updates the list of unoccupied NEC codes as appropriate.
2) Detects signal collisions and notifies users.
3) Estimates time and frequency offsets on received signals and transmits corrections on the control channel (tagged with the NEC identifier), i.e. the time and frequency pull-in loops are closed through the GS.
4) When the GS 12 determines that the HS 14 is in time and frequency sync, the HS 14 is given a traffic channel assignment.
Transmitter Implementation
A block diagram of the subscriber unit return link transmitter is shown in FIG. 3. The multiplexed input data (control and traffice) is buffered 27 and then covered with a long security code 28 which is synchronized with the system clock 29. The data is coded 30, interleaved 31 and then OQPSK modulated 32 onto the hopped carrier 33, after which it is upconverted 34 and amplified 35 for transmission via antenna 36. In traffic 37 and net entry channel 38 mode, the hop timing is synchronized with the symbol timing.
Receiver Implementation
The return link receiver is implemented in the ground station GS, and a functional block diagram is shown in FIG. 4. The received signal is first down converted 40 and dehopped with the hop sequence synchronized to the station clock as shown. The dehopped signal is converted 41 to baseband using I and Q mixers, where it is then digitized 42.
The sampled signal is passed through a fourth power nonlinearity 43 to remove the data modulation. The frequency error (referenced to zero) of the resulting cw signal, which is four times that of the carrier, is measured with a frequency discriminator 44 (typically a Cross Product Discriminator or an FFT based discriminator) and passed to the system controller which computes a correction to be transmitted to the user HS 14 on the outbound control link.
The frequency error is also averaged and passed to an Number Controlled Oscillator (NCO) 45 and complex multiplier which removes the estimated error in a feed-forward manner. A Block Phase Estimator (BPE) 46 is used to estimate the phase of the corrected output.
The NCO 45 output frequency is also divided 46 by four and mixed 47 with the baseband signal to yield a frequency corrected baseband signal with data modulation. This signal is demodulated 49 using the phase estimate from the BPE. As illustrated, the necessary symbol timing is also derived from the baseband signal.
The symbol synchronizer output is used in conjunction with the hop timing discriminator 63 to calculate a very accurate estimate of the hop timing offset. This estimate is forwarded to the system controller 18 which computes a correction to be transmitted to the user HS on the outbound control link 10.
The soft-decision demodulated data is deinterleaved 60 and decoded on a hop basis using four decoders 61-1 . . . 61-4 to resolve the phase ambiguity after the hop transition as described above. The selected correct output 64 is differentially decoded 65. A security code 66 is mixed with the output and demultiplexed 67 to provide the traffic data and control data.
While preferred embodiments of the invention have been described and illustrated, it will be appreciated that other embodiments of the invention will be readily apparent to those skilled in the art that various other embodiments, adaptations and modifications of the invention are possible. | A satellite network communication system in which a plurality of subscriber handset terminals communicate with a ground hub station on traffic frequency channels using spread spectrum orthogonal CDMA transmissions. The hub station includes a control generator for generating a net entry control channel for communicating synchronization correction signals (timing, frequency and power) to subscriber handset terminals and a return link receiver. Each subscriber handset terminal has a subscriber unit control channel receiver for receiving the control channel synchronization correction signals and a subscriber unit return link transmitter connected to receive the synchronization correction signals so that signals from all subscriber handset terminals arrive at the hub station in time, power and frequency synchronism. The subscriber unit return link transmitter includes frequency hopped spread spectrum carrier such that none of the signals occupies the same frequency bin at the same time. The net entry control channel transmits small time and frequency correction signals to each of the plurality of subscriber handset terminals. | 7 |
BACKGROUND OF THE INVENTION
1 Field of the Invention
The invention relates to treatment of aldehydes for the purpose of complying with waste disposal requirements established by federal and state environmental protection agencies.
2 Description of Related Art
Waste disposal of aldehydes has become increasingly more difficult over the years. Law requires treatment of wastes containing a certain amount of aldehyde prior to placement of the waste into the environment. The extent of such treatment may vary depending upon the location of where the waste is generated and the stringency of the environmental standards in that area. For example, waste containing aldehyde may be classified as a hazardous waste in California under 22 CAL. CODE REGS., TIT. 22, § 66696. Formaldehyde also may be considered a hazardous waste on the federal level under 40 C.F.R. § 261.33(e) if it is a commercial chemical product (e.g., pure technical grade formaldehyde or formaldehyde is the sole active ingredient of the product that is to be disposed). Every state has an environmental regulation that is at least as stringent as this formaldehyde standard. State regulations also may be more stringent than this standard.
Additionally, facilities that discharge waste water to Publicly Owned Treatment Works (“POTW”) or directly into navigable waters may be required to meet standards that are established by a government agency. The standard may vary for each facility depending upon the quality of the receiving water and the concentration of aldehyde found in the waste water that is discharged into the environment by industry in that area.
Waste containing aldehyde may be generated by a variety of processes. For example, aldehydes such as glutaraldehyde and ortho-phthalaldehyde (“OPA”) are used in disinfecting medical devices or instruments. Waste containing aldehydes also may be generated by painting operations, stripping operations related to floors, or other manufacturing operations.
Typically, ammonia and sodium bisulfite (“SBS”) are used to treat many aldehydes. These compounds, however, have not proven to be effective at neutralizing OPA in accordance with environmental regulations.
A waste is classified as a hazardous waste in California if the waste being examined “has an acute aquatic 96-hour LC 50 less than 500 milligrams per liter (mg/L) when measured in soft water (total hardness 40 to 48 milligrams per liter of calcium carbonate) with fathead minnows . . . ” 22 CAL. CODE REGS., TIT. 22, § 66696. LC 50 represents the concentration of a waste that is necessary to kill 50% of a particular animal exposed to a waste.
Note that a nonhazardous waste is generally considered by federal and state environmental agencies as a waste that does not satisfy the criteria set forth in defining a hazardous waste. Therefore, wastes generated in California that have a LC 50 >500 mg/L are nonhazardous wastes and wastes having LC 50 <500 mg/L are classified as hazardous. SBS, for example, in combination with OPA, produces a product that is generally considered hazardous under California environmental law as shown in Table 1 by LC 50 being consistently below 500 mg/L. For this study, CIDEX®OPA (commercially available from Advanced Sterilization Products®, a Johnson & Johnson Company of Irvine, Calif.) was used to supply the OPA.
TABLE 1
Neutralization Of OPA using SBS
Sample Type
OPA Content (%)
LC 50 (mg/l)
Comments
Fresh CIDEX ® OPA at
0.301%
31.1 mg/l
1
0.3% OPA
Fresh CIDEX ® OPA at
0.158%
50.4 mg/l
2
0.15% OPA
Reuse CIDEX ® OPA at
0.295%
31.1 mg/l
3
0.3% OPA
SBS/OPA = 4:1
N/A
68.3 mg/l
4
SBS/OPA = 2:1
N/A
46.3 mg/l
5
1. Fresh CIDEX ® OPA at 0.3% OPA was prepared by diluting the fresh Cidex OPA solution with deionized water.
2. Fresh CIDEX ® OPA at 0.15% OPA was prepared by diluting the fresh Cidex OPA solution with deionized water to the level of 0.15% of OPA.
3. Reuse of CIDEX ® OPA at 0.3% OPA was prepared by diluting the simulated reuse CIDEX ® OPA (14 days) with deionized water.
4. SBS/OPA = 4:1, 10% SBS (10 ml) was combined with 100 ml of the fresh CIDEX ® OPA solution at 0.3% OPA (sample 1 above) at the SBS/OPA molar ratio of 4 to 1 for 30 minutes, and then the combined solution was used in the 22 CAL. CODE REGS., TIT. 22, § 66696 test for California.
5. SBS/OPA = 2:1, 10% SBS (5 ml) was combined with or 100 ml of the fresh CIDEX ® OPA solution at 0.3% OPA (sample 1 above) at the SBS/OPA molar ratio of 2 to 1 for 30 minutes, and then the combined solution was used for the fish test in the 22 CAL. CODE REGS., TIT. 22, § 66696 test for California.
In addition to lacking the ability to effectively neutralize OPA, ammonia and SBS are problematic since they may be harmful to the environment.
FIG. 1 shows that when OPA is combined with SBS at the molar ratio of SBS/OPA=4:0 for 30 minutes, OPA has been neutralized since the OPA concentration is nondetectable in a high performance liquid chromatography (HPLC) analysis method, which has detection limit for OPA at 10 ppm. However, the end product is still classified as a hazardous waste as shown in Table 1. Therefore, even though the aldehyde is neutralized completely by a neutralizer, the end product may still be a hazardous waste.
Although glycine has been shown to neutralize glutaraldehyde (see H. Y. Cheung & M. R. W. Brown, Evaluation of Glycine As An Inactivator of Glutaraldehyde, 34 J. PHARM. 211 (1982)), the toxicity of reaction products of glycine has not been studied. Therefore, it is not known from this article whether the reaction product is nonhazardous. Accordingly, it is desirable to have a neutralizer that effectively neutralizes aldehydes in compliance with environmental standards and is less toxic to the environment.
There are a number of other challenges associated with treatment of aldehydes. One is to find a resulting end product that does not introduce any additional problems over the initial neutralization proposed. For example, it has been reported that treatment of aldehydes with neutralizing amino acids forms Schiff's bases which may have the effect of reverting back to the untreated aldehydes under certain conditions.
A method of solving the reversion problem is disclosed in commonly assigned and co-filed patent application U.S. Ser. No. 09/747,230, (Attorney Docket Number ASP-009), filed Dec. 22, 2000. The present invention offers another solution to treating aldehydes in a manner that does not require additional treating agents.
SUMMARY OF THE INVENTION
A device and method for removing aldehydes from a stream is disclosed. In one aspect, the invention provides a generally nonhazardous means for removing aldehydes in accordance with applicable environmental regulations prior to disposal.
In one embodiment, a method and device are disclosed for removing aldehydes from a waste stream comprising the step of:
a) contacting the waste stream containing the aldehyde with a solid primary amine thereby binding the aldehyde to the solid primary amine.
In other embodiments, the methods and devices include the solid primary amine comprising a compound having primary amine functionality which is chemically bonded to a support, preferably silica.
Advantages of this invention include treatment of aldehyde-containing wastes which will minimize or eliminate discharge of aldehydes and their derivatives to the environment. Also, since the treated waste is immediately disposed after treatment, there is no risk of mistakenly re-using of the treated waste. The invention also avoids the need to add chemicals to neutralize the aldehyde. In preferred embodiments, when support materials are used that involve use of high surface area particles, such as silica, any bio-hazard materials left in the used disinfectant solution are captured. Also, when silica is used, it affords an inexpensive source for support particles and amination of silica is a simple process. Once the invention treatment device has reached its capacity, it may be simply disposed according to solid waste disposal guidelines.
Additional features, embodiments, and benefits will be evident in view of the figures and detailed description presented below.
BRIEF DESCRIPTION OF THE DRAWINGS
The features, aspects, and advantages of the invention will become more thoroughly apparent from the following detailed description, appended claims, and accompanying drawings in which:
FIG. 1 shows the ratio of SBS:OPA and the concentration of OPA remaining in solution after 30 minutes from combining the ingredients.
FIG. 2 shows a schematic diagram of one embodiment for the device of this invention.
DETAILED DESCRIPTION OF THE INVENTION
The invention relates to treatment of waste containing aldehydes generated particularly from sterilizing medical devices (e.g., scalpels, scissors, endoscopes, etc.) or laboratory equipment (e.g., glassware) that have been exposed to microorganisms such as bacteria. Sterilizing includes disinfecting medical devices.
To remove aldehydes, the waste containing the aldehyde is contacted with a device that scavenges or binds the aldehyde before the waste is placed into a sewer system that may discharge to a POTW or into navigable waters.
The device and method of this invention offer an advantage over other typical methods using chemicals such as ammonia, sodium bisulfite, or other chemicals used to neutralize aldehydes since nothing further is required to be added to a waste as the waste is simply passed through the scavenging device which binds the aldehyde and prevents its discharge into the environment.
The operation of this invention may be depicted by the following equation:
R—CHO (aldehyde)+H 2 NR′(solid primary amine) →RHC=N—R′(solid imine)
As used herein, the term solid primary amine is intended to describe materials that have the functionality of a primary amine and is capable of scavenging or binding an aldehyde from a waste stream; thus the solid primary amine does not dissolve in solution but allows for removal of aldehydes from the waste stream through binding with the solid primary amine.
Solid primary amines, R—NH 2 , can be any solid polymer or co-polymer, or any solid chemical comprising primary amino groups. It can also include any support materials that have been aminated, coated, or impregnated to have the functionality of a primary amine. The solid primary amines can have one or more primary amino groups.
Examples of solid primary amines include, but are not limited to, the following chemicals:
(A) Silica Type Systems
(1) Aldehyde scavenger using silica with 3-aminopropyltrimethoxysilane (Amino-Silanes): It is advantageous to use silica as a support material since a very high density of amino groups can be introduced to the high surface area of silica particles (˜500 m 2 /g). Using this aminated polymer as filling material in a filtering cartridge, aldehydes will be caught as the used disinfectant solution passes through the cartridge. The aldehyde scavenger can be produced as below:
The aldehyde scavenger can then react with aldehyde to form the neutralized aldehyde as indicated with the following two equations.
(2) Aldehyde scavenger using silica with 3-aminopropyltriethoxysilane (Amino-Silanes): The trimethoxy group in the above example can be replaced by other similar groups, such as triethoxy group, to produce the same aldehyde scavenger.
(3) Scavenger using silica with N-(2-aminoethyl)-3-aminopropyltriethoxysilane (Amino-Silanes): The amino side-chain in 3-aminopropyltrimethoxysilane can be varied either by the structure feature or by the length of the chain to give aminated silica with similar property.
(4) Scavenger using silica with 3-glycidyloxypropyltrimethoxysilane (epoxy-silane): Using the similar methods, an amino group can be introduced in a separate step. For example, an epoxide group can be introduced to silica particles with the use of 3-glycidyloxypropyltrimethoxysilane, the amino group can then be attached to the intermediate chemical with a diamine, such as hexamethylenediamine (HDA), to form the final solid aldehyde scavenger containing the primary amine. Diamines other than HDA can also be used.
Using other epoxide compounds, such as 2(3,4-epoxycyclohexyl)ethyltrimethoxysilane, can also produce the silica with similar functionality.
The lengthened amino bearing chains, in the above examples, may reduce the steric hindrance on the local silica surface areas where the aldehydes, especially the bulkier aldehydes need to be neutralized.
(5) Scavenger using silica with (3-Isocyanatopropyl)triethoxysilane or (3-Isothiocyanatopropyl)trimethoxysilane (isocyano-silane or isothiocyano-silane): The corresponding isocyanates of the above silanes are another type of extender for aminated silica, such as (3-isocyanatopropyl)triethoxysilane, can bind to silica surface before binding the amino-moiety.
The following isothiocyanates can be also used.
(6) Aldehyde scavenger with multiple amino groups: One of the advantages to make aminated silica using epoxy group-bearing, isocyano group-bearing and isothiocyano group-bearing silica is the possibility to introduce dendrimer amino groups to the silica and thus the active reaction sites for aldehydes can be multiplied. Dendrimer is a type of functional polymer which contains many functional groups on the surface or on the outer-most shell. For example, this functional silica is formed when reacting with amino-rich molecules (small molecules or large polymers) where one of the amino groups is needed for attachment and the rest of the amino groups can be used for aldehyde scavenging. The simplest example is the reaction with tris(2-aminoethyl)amine as shown below where one amino group is used to attach to the silica while the rest of the two free amine groups can be used for aldehyde neutralization. Other amino-rich molecules (small molecules or large polymers) and silica (epoxy group-bearing, isocyano-bearing silica etc.) can also be used to give similar aldehyde scavengers with multiple amino groups.
Other starburst polymeric amines and comb polymers containing multiple amino groups can also be used in the same way to produce solid primary amine scavengers with multiple amino groups.
(B) Polymer-linked Systems
Polymer-linked systems are intended to comprise animated surfaces wherein a base polymer is chemically linked to an amine having primary amine functionality. Examples of this type include tris(2-aminoethyl)amine, polymer linked (Aldrich 4,7210-7), diethylenetriamine, polymer-linked (Aldrich 4,7978-0) (Refs. Booth, R. J.; Hodges, J. C. J. Am. Chem. Soc. 119, 4882, 1997; Parlow, J. J. et al. J. Org. Chem. 62, 5908, 1997; Routledge A. et al. Tetrahedron Lett, 38, 1227, 1997).
Another example is the intercalate formed upon heating of silica with polyallyamine. The intercalate formed is an organic/inorganic polymer which does not separate into their parent polymers due to intermolecular networking formed during heating.
This group may also include other types of amines supported or linked to a polymer system.
(C) Polymeric Amino Group-rich System
Several examples are given below which include some polymers suitable to introduce amino groups and some others already have rich amino groups.
(1) Polysaccharides-derived Polyamines: These are made from starch and cellulose which are “glucose polymers”. Amino groups can be attached to the backbone by selective oxidation, Schiff's base formation and NaBH 4 reduction, as shown below:
This natural polymer has high amine density since each sugar unit has a primary amino group. Chitosan's (1) wide natural source (from crab and shrimp shells) (2) low price and (3) biodegradation property make it attractive for the current application. However, the aldehyde scavenging capacity of this polymer is related to the powder size. Therefore, it's important to grind it to fine powder to be an efficient scavenger.
The device of the invention can be any container, cartridge, or filter with an inlet for receiving an aldehyde-containing stream and an outlet for releasing the treated stream having the neutralized aldehyde removed. The outlet can have an optional valve to control the flow rate of the aldehyde-containing stream.
FIG. 2 depicts a schematic of one embodiment of this invention involving the use of aminated silica particles as the solid primary amine. Referring to FIG. 2, a waste stream containing aldehyde, in this case o-phthalaldehyde, enters the device depicted as a cylinder. At the exit of the device, the treated stream is devoid of aldehyde having been bound to the aminated silica. Also, FIG. 2 depicts the optional control valve.
In practice, the completeness for the removal of aldehyde will be dependent on a number of variables readily apparent to one of skill in the art. Factors such as aldehyde concentration in the waste stream, waste flow rate, type of aldehyde to be removed, type of solid primary amine to be used, safety margin, etc., are some of the criteria needed to properly size the device. It will also be appreciated by those of skill in the art that factors such as support material particle size will be an adjustable parameter in setting an adequate flow rate and contact time to insure that the aldehyde has sufficient opportunity to bind.
The device of this invention will also have benefits in being suitable for use as cartridges that can easily be removed and replaced from a discharge waste line containing aldehydes. Additional filtering aids and/or materials may be added to the device to filter other unwanted material from the waste stream, but in the case when a high surface area particle, such as silica, is used to support the primary amine function, many materials such as proteins, blood residues will be captured by the cartridge via both physical filtration mechanism and hydrogen bonding principles.
After the device has reached the end of its utility for effectively removing the aldehyde, the cartridge will be disconnected from the waste line and be disposed like normal waste solid according to acceptable solid waste guidelines. It will be apparent to those of skill in the art that sensors may be used to detect breakthrough of aldehyde signaling a need for replacement of the cartridge. A convenient control to prevent interruption of waste treatment would be to automatically control flow valves to switch the flow of waste to a parallel cartridge allowing an operator time to change out the spent cartridge.
In the preceding detailed description, the invention is described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. | Methods and a device for removing aldehydes from a waste stream are disclosed. In a preferred embodiment, the device provides for and the method uses a chemical or an aminated surface having primary amine functionality resulting from the amination of a support material such as silica. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Provisional Application Ser. No. 61/058,846, filed Jun. 4. 2008, The disclosure of which is expressly incorporated by reference herein in its entirely.
TECHNICAL FIELD
[0002] This disclosure relates to a device for advertising in public venues. More particularly, this disclosure relates to a device for combining advertising, sales, service transactions, and other communication and a convenience hook in a compact apparatus.
BACKGROUND
[0003] Many venues, such as stadiums and theaters, provide seating consisting of, for example, seats or backed benches. In such venues it is common for food, drink, souvenirs and other products to be offered for sale to a patron (i.e., “user”). Such sales transactions may occur directly on the venue “floor” at or near a user's seal. Such transactions, which may be available from walking vendors offering products, may be limited to what is immediately available on the venue floor at the time. Alternatively, the user must leave the seat and seek out a particular product at fixed vendor locations distributed around the venue, often out of view of the ongoing event, but without the user's foreknowledge of the location of the vendor, afterwards returning to the seat. This is an inconvenience that may deprive the user of a portion of time which could be better devoted to enjoying the event attended, e.g., a spectator sport.
[0004] Furthermore, in public venues there exists a concern for safely in the event of required evacuation. The user is often not conveniently provided with instructions for evacuation or response to a situation of urgency.
[0005] In addition to purchases, users often attend such venues with personal property, such as purses, bags, backpacks, outer garments, and the like. It is well known that many of such items are temporarily stored on the floor near or under the user's seat. Such items may become obstacles that impede egress/ingress for users or vendors and may even contribute to accidents, with consequences for liability and litigation.
[0006] There is a need, therefore, for an apparatus that may simultaneously improve vendor services, provide critical information support in case of matters of urgency, and improve user safely and convenience.
SUMMARY
[0007] A hook apparatus includes a support member with a front side and a back side. A hook extends from the front side of the support member for hanging objects. A shelter structure also extends from the front side of the support member and is positioned partially around but spaced apart from the hook. The shelter structure may also serve as a second hook for hanging objects. A communications device extends from the front side of the support member and has a display positioned above and spaced apart from the shelter structure. The hook and the shelter structure may each have a lip to prevent objects from slipping off. The back side of the support member is adapted to be secured to a mounting surface. An interface adapter plate may be included to enable securing between the back side and the mounting surface.
[0008] The display of the communications device may be either a passive mount for receiving a removable insert with an advertising message or other information, or my be an electronic communication device with an electronic display. Communications may be via secure modes of information transmission that are well know. The apparatus may be operationally coupled to a remote server to provide emergency services, information, and coupled to interactive communications whereby a patron could order and purchase products, services, and the like, from vendors.
DESCRIPTION OF FIGURES
[0009] FIG. 1A is a perspective view of an exemplary advertising apparatus with hook according to an embodiment of the disclosure.
[0010] FIG. 1B is a top view of the apparatus of FIG. 1A .
[0011] FIG. 1C is a from view of the apparatus of FIG. 1A .
[0012] FIG. 1D is a side view of the apparatus of FIG. 1A .
[0013] FIG. 2 is an overhead view of the apparatus of FIG. 1A attached to a seat back.
[0014] FIG. 3 is a perspective view of the apparatus of FIG. 1A with a card holder for display of advertising and/or information.
[0015] FIG. 4 is a perspective view of an embodiment of the apparatus with a display, a data entry keypad, a transceiver, a debit/credit card reader and a printer.
[0016] FIG. 5 is a block diagram of an embodiment of the apparatus configured for interactive communication.
DETAILED DESCRIPTION
[0017] A hook apparatus providing a combination of a hook and information/advertising/communication is disclosed. The hook apparatus may be attached to the back of a seat in front of a patron at a venue, such as, for example, a theater or stadium, or otherwise mounted on any other selected surface. For example, the apparatus may also be placed on doors, walls and in other locations where such apparatus is convenient and beneficial. For example, the hook with advertising may be placed in passenger transportation systems, waiting rooms, and any location where persons may pass through or spend an interval of time, may be in temporary need of safely placing personal property, and would be in a position to receive information, advertising, and the like.
[0018] FIGS. 1A to 1D and 2 illustrate various views of an exemplary hook apparatus 10 with a hook 21 , according to an embodiment of the disclosure. The hook apparatus 10 includes a support member 1 that has a front side 20 and a back side 25 . FIG. 2 is an exemplary illustration of how apparatus 10 is adapted to attach the back side 25 of the hook apparatus 10 to a surface (such as a seat back 27 or a wall) and provides for supporting a parcel hung from the hook 21 while preventing the hook from causing injury or property damage. If the seat back 27 is curved, attachment may be accomplished in a variety of ways, either generically or by customized adaptation to conform to the seal back 27 . For example, the shape of the back side 25 of the hook apparatus 10 may be contoured to conform to the shape of the seat back 27 of a venue chair ( FIG. 2 ). Alternatively, the hook apparatus 10 may include an adaptor plate 31 to interface and attach the back side 25 to the seat back 27 ( FIG. 2 ). Attachment mechanisms to secure the hook apparatus 10 to the interface adaptor plate 31 and/or the seat back 27 , and to attach the interface adaptor plate 31 to the seat back 27 may include screws, nails, bolts, clips, adhesives, flanges, hooks, and the like. The hook apparatus 10 may be placed on the seat back 27 in various locations, as shown in FIG. 2 , for example, where the benefit of placement may include minimizing interference with user comfort, to share the hook apparatus 10 between two users, and the like. In more generic cases, where the surface is flat, for example, the interface adaptor plate 31 may not be needed.
[0019] Referring again to FIGS. 1A-1D , the hook apparatus 10 includes the hook 21 extending from the front side 20 of the support member 1 , on which a purse, parcel, garment, or other articles, may be hung. The hook apparatus further includes a display device portion 16 of a communication device to provide information. The display device portion 16 extends from the support member 1 preferably above and spaced apart from a shelter structure 22 (described below).
[0020] The hook 21 may include a hook protrusion 11 (e.g., a rod) extending from the front side 20 of the hook apparatus 10 of support member 1 , the protrusion also having a distal end 23 . The hook protrusion 11 may have a hook retention lip 12 at the distal end 23 to prevent hanging articles from slipping off the hook 21 . Articles and objects placed on the hook 21 hang downward. A shelter structure 22 “tents” the hook 21 by extending from the front side 20 of the support member 1 as a shelter hook protrusion 13 having a distal end. The shelter structure 22 is in a spaced relationship apart from the hook 21 . In an embodiment, the hook 21 may not extend from the front side 20 beyond the extent of the shelter structure 22 in a manner that can cause injury to a person, or damage, such as hooking, snagging and/or tearing clothing as a person passes by. The shelter structure 22 is placed apart and preferably below the display device portion 16 .
[0021] The shelter structure 22 is preferably curved, having no sharp edges or corners. The shelter structure 22 preferably surrounds the hook 21 on three sides (e.g., above and laterally) to prevent casual or unintended snagging by contact with the hook 21 . The shelter structure 22 is configured so that the bottom side of the hook 21 is exposed, enabling objects hung from the hook 21 to hang down freely. The shelter structure 22 may also be shaped to have a shelter hook retention lip 14 at the shelter hook protrusion 13 distal end to provide an additional second hook capability on which to hang additional articles safely while preventing slippage, as described above.
[0022] Display of information may be passive or electronically active. In one embodiment, referring to FIG. 3 , a passive display 35 of hook apparatus 10 may contain a card holder 37 for holding an information card 39 . The information card 39 may include advertising, safely information, or the like. In an embodiment, multiple instances (e.g., pages) of information may be provided in the passive display 35 , wherein the pages may be changed, as desired, or may be permanent. The passive display may be located in substantially the same location as display device portion 16 of FIG. 1A .
[0023] An active display device portion 16 (e.g., see FIG. 1A ) may be provided having an electro-optically active display screen such as, for example, a liquid crystal display, plasma display or the like, and electronics to drive the display screen and interface to a transceiver 19 for communication with a remote server. Electro-optic display devices are well known in the display arts. The transceiver 19 may be located within the active display device portion 16 or, alternatively, elsewhere in the hook apparatus 10 support member 1 (as shown in FIGS. 1A , 1 D, and 4 ). The active display device portion 16 is preferably located above and spaced apart from the shelter structure 22 . The active display device portion 16 may further include audio output capability, coupled to the transceiver, to present information audibly.
[0024] Referring to FIG. 4 , a hook apparatus 50 may further include a keypad 51 comprising, but not limited to, a “hard” typewriter-like keyboard, and/or a “soft button” or “soft-key” touch screen keyboard. Touch screens are also well known in the art of electronic display. Using the keypad 51 , a patron (e.g., user) may select from a displayed menu any of a plurality of screens providing information. The keypad 51 is coupled to the display device portion 16 and the transceiver 19 .
[0025] In one embodiment, power to operate the hook apparatus 10 may be supplied by directly wired power lines (e.g., low voltage, provided from a grid throughout the venue). In another embodiment, the hook apparatus 10 may be powered by batteries.
[0026] If the user desires, for example, to find the location of a nearest restroom or food vendor, an interactive menu provided on the display device portion 16 can be navigated via the keypad 51 to direct the user to a nearest location, where the direction may be provided by a map, written and/or audio instructions. For direction/location types of information, it is useful for the hook apparatus 10 to be equipped with self-location capability. In one embodiment, this may be, for example, a hard-wired connection that identifies the location of the hook apparatus 10 at the venue. Alternatively, in an embodiment, the transceiver 19 may be wireless and transmitting a unique signal from which the location can be determined. Additionally, in an embodiment, a global positioning system (GPS), or the like, that locates each apparatus within the venue may perform the same function. Thus, a mapping capability to route the user from his/her seat location to a selected destination is enabled. Examples of wireless communication systems include, but are not limited to. Wi-Fi local area networks, wide area networks (WAN), and broadband wireless networks. In a wireless position location system, location identification data transmitted as a coded transmission by the transceiver 19 , and/or triangulation from GPS-type data, or the like, may be used to identify the user location and/or a destination.
[0027] In some embodiments, the user may be able to place a menu order for particular foods, beverages or products, which can be delivered to the user's seat. The transaction may be completed, for example, by cash upon delivery, or by credit card transaction, in which case, such transactions may be transmitted securely. Secure communication is a well known field of art (see, for example “Secure Communication”.” Wikipedia, at http://en.wikipedia.org/wiki/Secure communication).
[0028] A receipt confirmation record of the transaction can be provided, for example, through a credit card transaction, and/or an email. Referring to FIG. 4 , in a hook apparatus 50 , the debit/credit card transaction may be executed via the keypad 51 . Alternatively, the hook apparatus 50 may comprise a debit/credit card reader 53 coupled to the transceiver 19 . In an embodiment, a printer 55 may be coupled to the hook apparatus 50 to provide a hardcopy record 57 to the purchaser. The printer may be included in hook apparatus 50 or may be remotely coupled to the hook apparatus 50 by a communications link via the transceiver 19 .
[0029] FIG. 5 is a block diagram of an embodiment of the hook apparatus 10 engaged in interactive communication. Data entered via the display device portion 16 and the keypad 51 is transmitted from the transceiver 19 to a remote server 61 . A mobile vendor may be equipped with a wireless vendor communications device 63 to be alerted by the server 61 that a user at a particular location desires a product supplied by the vendor. The communications device 63 may be equipped with position location capability. A vendor so equipped (preferably nearest to the user) and carrying (or able to obtain) the product, may then receive the order from the server 61 and advance to the identified hook apparatus 50 location to fulfill the transaction request. This may beneficially reduce the wait time for the user to receive the product or service, enable the user to continue enjoying the venue activity (e.g., a spectator sport) with only minor interruption, and reduce the delays a vendor may encounter to identify and fulfill sales opportunities. Such capability enables vendors to achieve faster response to user requests, thereby improving sales volume and user satisfaction.
[0030] In addition to being menu-driven, advertising or other information may periodically change and be presented on the display to inform the user of the range of services and products available. In the case of an interactive display, emergency response may also be provided to the seat location when the display is suitably operated, or in emergency situations. For example, first-aid, emergency alert, and evacuation procedures may be displayed for contingency benefit to the user.
[0031] Although the present disclosure and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the disclosure as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the present disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present disclosure. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps. | A hook apparatus includes a front side and a back side. A hook extending from the front side is included for hanging objects. A shelter structure extends from the front side positioned around and apart from the hook. The shelter structure may serve as a second hook for hanging objects. A communications device extends from the body, at least a portion of which is above and spaced apart from the shelter structure. The back side of the hook apparatus is adapted to be secured to a surface. An interface adapter plate between the back side and the mounting surface may be provided to enable the securing. The communications device includes a display device that is either passive or capable of interactive communication of information. The apparatus may be operationally coupled to a remote server to alert vendors to deliver purchased products, services, and/or to provide emergency services to the user. | 8 |
RELATED APPLICATIONS
[0001] The disclosure of this application is related to co-pending U.S. application Ser. No. 12/485,684, filed on Jun. 16, 2009; co-pending U.S. application Ser. No. 12/246,295, filed on Oct. 6, 2008; U.S. application Ser. No. 12/069,642 filed on Feb. 11, 2008; U.S. application Ser. No. 12/254,369, filed on Nov. 4, 2008 which is a divisional of Ser. No. 12/069,642; U.S. application Ser. No. 11/849,033, filed on Aug. 31, 2007; U.S. application Ser. No. 11/830,576, filed on Jul. 30, 2007; and U.S. application Ser. No. 11/500,053, filed on Aug. 7, 2006, the contents of which are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present application is directed to a solar cell subassembly for use in a concentrator photovoltaic system, more particularly, to an encapsulated solar cell receiver including a solar cell, metallized ceramic substrate and a concentrator optical element.
BACKGROUND
[0003] Historically, solar power (both in space and terrestrially) has been predominantly provided by silicon solar cells. In the past several years, however, high-volume manufacturing of high-efficiency III-V compound semiconductor multijunction solar cells for space applications has enabled the consideration of this alternative technology for terrestrial power generation. Compared to silicon, III-V compound semiconductor multifunction cells are generally more radiation resistant and have greater energy conversion efficiencies, but they tend to cost more to manufacture. Some current III-V compound semiconductor multijunction cells have energy efficiencies that exceed 27%, whereas silicon technologies generally reach only about 17% efficiency. Under concentration, some current III-V compound semiconductor multijunction cells have energy efficiencies that exceed 37%.
[0004] Generally speaking, the multijunction cells are of n-on-p polarity and are composed of a vertical stack of InGaP/(In)GaAs/Ge semiconductor structures. The III-V compound semiconductor multijunction solar cell layers are typically grown via metal-organic chemical vapor deposition (MOCVD) on germanium (Ge) substrates. The use of the Ge substrate permits a junction to be formed between n- and p-type Ge, thereby utilizing the substrate for forming the bottom or low band gap subcell. The solar cell structures are typically grown on 100-mm diameter Ge wafers with an average mass density of about 86 mg/cm 2 . In some processes, the epitaxial layer uniformity across a platter that holds 12 or 13 Ge substrates during the MOCVD growth process is better than 99.5%. The epitaxial wafers can subsequently be processed into finished solar cell devices through automated robotic photolithography, metallization, chemical cleaning and etching, antireflection (AR) coating, dicing, and testing processes. The n- and p-contact metallization is typically comprised of predominately Ag with a thin Au cap layer to protect the Ag from oxidation. The AR coating is a dual-layer TiO x /Al 2 O 3 dielectric stack, whose spectral reflectivity characteristics are designed to minimize reflection at the coverglass-interconnect-cell (CIC) or solar cell assembly (SCA) level, as well as, maximizing the end-of-life (EOL) performance of the cells.
[0005] In some compound semiconductor multijunction cells, the middle cell is an InGaAs cell as opposed to a GaAs cell. The indium concentration may be in the range of about 1.5% for the InGaAs middle cell. In some implementations, such an arrangement exhibits increased efficiency. The advantage in using InGaAs layers is that such layers are substantially better lattice-matched to the Ge substrate.
SUMMARY
[0006] According to an embodiment, a solar cell subassembly for converting solar energy to electricity includes an optical element defining an optical channel, a solar cell receiver comprising:
[0000] a support; a solar cell mounted on the support adjacent to the optical element and in the optical path of the optical channel, the solar cell comprising one or more III-V compound semiconductor layers and capable of generating in excess of 20 watts of peak DC power; and an encapsulant covering the support, the solar cell, and at least a portion of the exterior sides of the optical element.
[0007] In another aspect, the present invention provides a method of manufacturing a solar cell receiver, comprising: providing a support; mounting a solar cell comprising one or more III-V compound semiconductor layers and capable of generating in excess of 20 watts of peak DC power on the support; mounting an optical element defining an optical channel over the solar cell so that the solar cell is disposed in the optical path of the optical channel; and encapsulating the support, the solar cell, and at least a portion of the exterior sides of the optical element.
[0008] Of course, the present invention is not limited to the above features and advantages. Those skilled in the art will recognize additional features and advantages upon reading the following detailed description, and upon viewing the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a partially exploded perspective view of an embodiment of a solar cell receiver including a solar cell, a metallized ceramic substrate and a heat sink.
[0010] FIG. 2 shows the solar cell and the metallized ceramic substrate of FIG. 1 in more detail.
[0011] FIG. 3 is a cross-sectional view of the solar cell, the metallized ceramic substrate and the heat sink shown in FIG. 1 .
[0012] FIG. 4 is a cross-sectional view of the solar cell, the metallized ceramic substrate and the heat sink shown in FIG. 3 after attaching the concentrator optical element and the encapsulant.
DETAILED DESCRIPTION
[0013] Details of the present invention will now be described including exemplary aspects and embodiments thereof. Referring to the drawings and the following description, like reference numbers are used to identify like or functionally similar elements, and are intended to illustrate major features of exemplary embodiments in a highly simplified diagrammatic manner. Moreover, the drawings are not intended to depict every feature of the actual embodiment nor the relative dimensions of the depicted elements, and are not drawn to scale.
[0014] Solar cell receivers include a solar cell for converting solar energy into electricity. In various implementations described herein, a triple-junction III-V compound semiconductor solar cell is employed, but other types of solar cells could be used depending upon the application. Solar cell receivers often contain additional components, e.g., connectors for coupling to an output device or other solar cell receivers.
[0015] For some applications, a solar cell receiver may be implemented as part of a solar cell module. A solar cell module may include a solar cell receiver and a lens coupled to the solar cell receiver. The lens is used to focus received light onto the solar cell receiver. As a result of the lens, a greater concentration of solar energy can be received by the solar cell receiver. In some implementations, the lens is adapted to concentrate solar energy by a factor of 400 or more. For example, under 500-Sun concentration, 1 cm 2 of solar cell area produces the same amount of electrical power as 500 cm 2 of solar cell area would, without concentration. The use of concentration, therefore, allows substitution of cost-effective materials such as lenses and mirrors for the more costly semiconductor cell material. Two or more solar cell modules may be grouped together into an array. These arrays are sometimes referred to as “panels” or “solar panels.”
[0016] FIG. 1 illustrates an embodiment of a solar cell receiver 100 including a solar cell 102 . In one embodiment, the solar cell 102 is a triple-junction III-V compound semiconductor solar cell which comprises a top cell, a middle cell and a bottom cell arranged in series. In another embodiment, the solar cell 102 is a multifunction solar cell having n-on-p polarity and is composed of InGaP/(In)GaAs III-V compounds on a Ge substrate. In each case, the solar cell 102 is positioned to receive focused solar energy from a secondary optical element 104 .
[0017] The secondary optical element 104 is positioned between the solar cell 102 and a primary focusing element (not shown) such as a lens. The secondary optical element 104 is generally designed to collect solar energy concentrated by the corresponding lens toward the upper surface of the solar cell 102 . The secondary optical element 104 includes an entry aperture 105 that receives light beams from the corresponding lens and an exit aperture 107 that transmits the light beams to the solar cell 102 . The secondary optical element 104 includes an intermediate region 112 between the apertures 105 , 107 . Under ideal conditions, the lens associated with the secondary optical element 104 focuses the light directly to the solar cell 102 without the light hitting against the secondary optical element 104 .
[0018] In most circumstances, the lens does not focus light directly on the solar cell 102 . This may occur due to a variety of causes, including but not limited to chromatic aberration of a refractive lens design, misalignment of the solar cell 102 relative to the lens during construction, misalignment during operation due to tracker error, structural flexing, and wind load. Thus, under most conditions, the lens focuses the light such that it reflects off the secondary optical element 104 . The difference between an ideal setup and a misaligned setup may be a minor variation in the positioning of the lens of less than 1°.
[0019] The secondary optical element 104 therefore acts as a light spill catcher to cause more of the light to reach the solar cell 102 in circumstances when the corresponding lens does not focus light directly on the solar cell 102 . The secondary optical element 104 can include a reflective multi-layer intermediate region such as the kind disclosed in U.S. patent application Ser. No. 12/402,814 filed on Mar. 12, 2009, the content of which is incorporated herein by reference in its entirety. The reflective multi-layer intermediate region can be formed from different materials and have different optical characteristics so that the reflectivity of the light beams off secondary optical element 104 and transmitted to the solar cell 102 optimizes the aggregate irradiance on the surface of the solar cell 102 over the incident solar spectrum. For example, in some implementations, the inner surface of the body 112 of the secondary optical element 104 can be coated with silver or another material for high reflectivity. In some cases, the reflective coating is protected by a passivation coating such as SiO 2 to protect the secondary optical element 104 against oxidation, tarnish or corrosion.
[0020] The body 112 of the secondary optical element 104 has one or more mounting tabs 114 for attaching the body 112 to a bracket 116 via one or more fasteners 118 . The bracket 116 is provided for mounting the secondary optical element 104 to a heat sink 120 via one or more fasteners 122 . The bracket 116 is thermally conductive so that heat energy generated by the secondary optical element 104 during operation can be transferred to the heat sink 120 and dissipated. As shown in this implementation, the secondary optical element 104 has four reflective walls. In other implementations, different shapes (e.g., three-sided to form a triangular cross-section) may be employed. The secondary optical element 104 can be made of metal, plastic, or glass or other materials.
[0021] In one embodiment as shown in FIG. 2 , a concentrator 106 is disposed between the exit aperture 107 of the secondary optical element 104 and the solar cell 102 . The concentrator 106 is preferably glass and has an optical inlet 108 and an optical outlet 110 . In one embodiment, the concentrator 106 is solid glass. The concentrator 106 amplifies the light exiting the secondary optical element 104 and directs the amplified light toward the solar cell 102 . In some implementations, the concentrator 106 has a generally square cross section that tapers from the inlet 108 to the outlet 110 . In some implementations, the optical inlet 108 of the concentrator 106 is square-shaped and is about 2 cm×2 cm and the optical outlet 110 is about 0.9 cm×0.9 cm. The dimensions of the concentrator 106 may vary with the design of the solar cell module and the receiver. For example, in some implementations the dimensions of the optical outlet 110 are approximately the same as the dimensions of the solar cell 102 . In one embodiment, the concentrator 106 is a 2× concentrator. The bottom surface of the concentrator 106 can be directly attached to the upper surface of the solar cell 102 using an adhesive such as a silicone adhesive. The solar cell 102 converts the incoming sunlight directly into electricity by the photovoltaic effect.
[0022] A bypass diode 124 is connected in parallel with the solar cell 102 . In some implementations, the diode 124 is a semiconductor device such as a Schottky bypass diode or an epitaxially grown p-n junction. For purposes of illustration, the bypass diode 124 is a Schottky bypass diode. External connection terminals 125 and 127 are provided for connecting the solar cell 102 and the diode 124 to other devices, e.g., adjacent solar cell receivers (not shown).
[0023] The functionality of the bypass diode 124 can be appreciated by considering multiple solar cells 102 connected in series. Each solar cell 102 can be envisioned as a battery, with the cathode of each of the diodes 124 being connected to the positive terminal of the associated “battery” and the anode of each of the diodes 124 being connected to the negative terminal of the associated “battery.” When one of the serially-connected solar cell receivers 100 becomes damaged or shadowed, its voltage output is reduced or eliminated (e.g., to below a threshold voltage associated with the diode 124 ). Therefore, the associated diode 124 becomes forward-biased, and a bypass current flows only through that diode 124 (and not the solar cell 102 ). In this manner, the non-damaged or non-shadowed solar cell receivers 100 continue to generate electricity from the solar energy received by those solar cells. If not for the bypass diode 124 , substantially all of the electricity produced by the other solar cell receivers would pass through the shadowed or damaged solar cell receiver, destroying it, and creating an open circuit within, e.g., the panel or array. The solar cell receiver 100 also includes a ceramic substrate 126 such as an alumina substrate for mounting of the solar cell 102 and the heat sink 120 for dissipating heat generated by the solar cell 102 during operation.
[0024] FIG. 2 illustrates the solar cell 102 and the ceramic substrate 126 in more detail. The ceramic substrate 126 has metallized upper and lower surfaces 128 and 130 . Both surfaces 128 and 130 of the ceramic substrate 126 are metallized to increase the heat transfer capacity of the ceramic substrate 126 , enabling the solar cell receiver 100 to more adequately handle rapid temperature changes that occur due to abrupt changes in solar cell operating conditions. For example, the solar cell 102 generates heat energy when converting light to electricity. Having both the upper and lower surfaces 128 and 130 of the ceramic substrate 126 metallized provides for a faster transfer of the heat energy from the solar cell 102 to the heat sink 120 for dissipation. The opposite condition occurs when the solar cell 102 becomes suddenly shaded. That is, the solar cell 102 stops producing electricity and rapidly cools as does the secondary optical element 104 . The metallized upper and lower surfaces 128 and 130 of the ceramic substrate 126 prevent the solar cell 102 from cooling too rapidly by transferring heat energy from the heat sink 120 to the solar cell 102 , and depending on the thermal conditions, to the secondary optical element 104 as well. The increased heat transfer capacity of the solar cell receiver 100 reduces the amount of stress imparted to the interface between the solar cell 102 and the ceramic substrate 126 during rapid temperature changes, ensuring a reliable solar cell-to-substrate interface.
[0025] The metallized upper surface 128 of the ceramic substrate 126 is in contact with the solar cell 102 and has separated conductive regions 132 and 134 for providing isolated electrically conductive paths to the solar cell 102 . The first conductive region 132 provides an anode electrical contact point for the solar cell 102 and the second conductive region 134 provides a cathode electrical contact point for the solar cell 102 . The solar cell 102 has a conductive lower surface 136 out-of-view in FIG. 2 , but visible in the cross-section of FIG. 3 that is positioned on and connected to the first conductive region 132 of the metallized upper surface 128 of the ceramic substrate 126 . The opposing upper surface 138 of the solar cell 102 has a conductive contact area 140 connected to the second conductive region 134 of the ceramic substrate 126 .
[0026] In one embodiment, the conductive lower surface 136 of the solar cell 102 forms an anode terminal of the solar cell 102 and the conductive contact area 140 disposed at the upper surface 138 of the solar cell 102 forms a cathode terminal. According to this embodiment, the conductive lower surface 136 of the solar cell 102 is positioned on the first conductive region 132 of the ceramic substrate 126 and electrically isolated from the second conductive region 134 to ensure proper operation of the solar cell 102 . In one embodiment, the first conductive region 132 of the ceramic substrate 126 is at least partly surrounded on three sides by the second conductive region 134 about a periphery region of the ceramic substrate 126 .
[0027] In one embodiment, the conductive contact area 140 disposed at the upper surface 138 of the solar cell 102 occupies the perimeter of the solar cell 102 . In some implementations, the upper conductive contact area 140 can be smaller or larger to accommodate the desired connection type. For example, the upper conductive contact area 140 may touch only one, two or three sides (or portions thereof) of the solar cell 102 . In some implementations, the upper conductive contact area 140 is made as small as possible to maximize the area that converts solar energy into electricity, while still allowing electrical connection. While the particular dimensions of the solar cell 102 will vary depending on the application, standard dimensions are about a 1 cm 2 . For example, a standard set of dimensions can be about 12.58 mm×12.58 mm overall, about 0.160 mm thick, and a total active area of about 108 mm 2 . For example, in a solar cell 102 that is approximately 12.58 mm×12.58 mm, the upper conductive contact area 140 can be about 0.98 mm wide and the active area can be about 10 mm×10 mm.
[0028] The upper conductive contact area 140 of the solar cell 102 may be formed of a variety of conductive materials, e.g., copper, silver, and/or gold-coated silver. In this implementation, it is the n-conductivity cathode (i.e. emitter) side of the solar cell 102 that receives light, and accordingly, the upper conductive contact area 140 is disposed on the cathode side of the solar cell 102 . In one embodiment, the upper conductive contact area 140 of the solar cell 102 is wire bonded to the second conductive region 134 of the metallized upper surface 128 of the ceramic substrate 126 via one or more bonding wires 142 .
[0029] The bypass diode couples the first conductive region 132 of the metallized upper surface 128 of the ceramic substrate 126 to the second conductive region 134 . In one embodiment, a cathode terminal of the bypass diode 124 is connected to the anode terminal of the solar cell 102 via the first conductive region 132 of the ceramic substrate 126 and an anode terminal of the bypass diode 124 is electrically connected to the cathode terminal of the solar cell 102 via the second conductive region 134 of the ceramic substrate 126 . The anode terminal of the solar cell 102 is formed by the lower conductive surface 136 of the solar cell 102 as described above and is out-of-view in FIG. 2 , but visible in the cross-section of FIG. 3 . The cathode terminal of the solar cell 102 is formed by the upper conductive contact area 140 of the solar cell 102 also as described above. The external connection terminals 125 and 127 disposed on the metallized upper surface 128 of the ceramic substrate 126 provide for electrical coupling of a device to the solar cell 102 and the bypass diode 124 . In some implementations, the connector terminals 125 and 127 correspond to anode and cathode terminals, and are designed to accept receptacle plugs (not shown) for connection to adjacent solar cell receivers.
[0030] The upper surface 128 of the ceramic substrate 126 can be metallized by attaching metallization layers 132 and 134 to the substrate. In one embodiment, holes 144 are formed in the metallization layers 132 , 134 . FIG. 2 shows the ceramic substrate 126 having two metallization layers 132 and 134 attached to the upper substrate surface 128 (the lower metallized surface is out of view in FIG. 2 , but visible in the cross-section of FIG. 3 ). The metallization layers 132 and 134 are attached to the upper surface 128 of the ceramic substrate 126 by high temperature reactive bonding or other type of bonding process. The lower surface 130 of the ceramic substrate 126 can be similarly metallized and attached to the heat sink 120 .
[0031] FIG. 3 illustrates a cross-sectional view of the solar cell 102 , ceramic substrate 126 and heat sink 120 of the solar cell receiver 100 along the line labeled X-X′ in FIG. 1 . The secondary optical element 104 , light concentrator 106 and terminals 125 , 127 are not shown in FIG. 3 for ease of illustration. The upper and lower surfaces 128 and 130 of the ceramic substrate 126 are metallized. The upper metallized surface 128 of the substrate 126 has separated conductive regions 132 and 134 for providing electrically isolated anode and cathode connections to the solar cell 102 as described above.
[0032] The solar cell 102 has a conductive lower surface 136 connected to the conductive region 132 of the metallized upper surface 128 of the ceramic substrate 126 . In one embodiment, the conductive lower surface 136 of the solar cell 102 forms the anode terminal of the solar cell 102 and the conductive contact area 140 disposed at the upper surface 138 of the solar cell 102 forms the cathode terminal of the solar cell 102 . The conductive lower surface 136 of the solar cell 102 is positioned on the first conductive region 132 of the metallized upper surface 128 of the ceramic substrate 126 and electrically isolated from the second conductive region 134 to ensure proper operation of the solar cell 102 .
[0033] The lower surface 130 of the ceramic substrate 126 also has a metallization layer 148 that is bonded to the heat sink 120 with a highly thermally conductive attach media 150 , such as a metal-filled epoxy adhesive or solder. Filling an epoxy adhesive with metal increases the thermal conductivity of the interface between the ceramic substrate 126 and the heat sink 120 , further improving the heat transfer characteristics of the solar cell receiver 100 . In one embodiment, the highly thermally conductive attach media 150 is a metal-filled epoxy adhesive having a thickness t epoxy of approximately 1 to 3 mils. The metal-filled epoxy adhesive can be applied to the lower metallized surface 130 of the ceramic substrate 126 , the heat sink 120 or both and then cured to bond the heat sink 120 to the substrate 126 . In one embodiment, the heat sink 120 is a single-piece extruded aluminum heat sink as shown in FIG. 1 .
[0034] The solar cell receiver 100 can be manufactured by providing the metallized ceramic substrate 126 and connecting the conductive lower surface 136 of the solar cell 102 to the first conductive region 132 of the metallized upper surface 128 of the substrate 126 . The conductive contact area 140 disposed at the upper surface 138 of the solar cell 102 is connected to the second conductive region 134 of the metallized upper surface 128 of the ceramic substrate 126 , e.g. via one or more bond wires 142 . The heat sink 120 is bonded to the lower metallized surface 130 of the ceramic substrate 126 with the metal-filled epoxy adhesive 150 .
[0035] FIG. 4 illustrates a cross-sectional view of the solar cell 102 , ceramic substrate 126 and heat sink 120 of the solar cell receiver 100 along the line labeled X-X′ in FIG. 1 after the bonding of the light concentrator 106 to the upper surface 138 of the solar cell 102 by means of a suitable light transparent adhesive 151 . After attachment of the light concentrator 106 , the solar cell 102 is surrounded by an encapsulant 152 , one embodiment of which may be silicone based. The encapsulant is applied over the entire portion of the ceramic substrate 126 surrounding the solar cell 102 , including over the region between the heat sink 120 and the metallized lower surface 130 of the ceramic substrate 126 , as well as optionally over the diode 124 , and then the encapsulant is subsequently cured by heat or other suitable process.
[0036] Spatially relative terms such as “under”, “below”, “lower”, “over”, “upper”, and the like, are used for ease of description to explain the positioning of one element relative to a second element. These terms are intended to encompass different orientations of the device in addition to different orientations than those depicted in the figures. Further, terms such as “first”, “second”, and the like, are also used to describe various elements, regions, sections, etc and are also not intended to be limiting. Like terms refer to like elements throughout the description.
[0037] As used herein, the terms “having”, “containing”, “including”, “comprising” and the like are open ended terms that indicate the presence of stated elements or features, but do not preclude additional elements or features. The articles “a”, “an” and “the” are intended to include the plural as well as the singular, unless the context clearly indicates otherwise.
[0038] The present invention may be carried out in other specific ways than those herein set forth without departing from the scope and essential characteristics of the invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein. | A solar cell receiver subassembly for use in a concentrating solar system which concentrates the solar energy onto a solar cell by a factor of 1000 or more for converting solar energy to electricity, including an optical element defining an optical channel, a solar cell receiver having a support; a solar cell mounted on the support adjacent to the optical element and in the optical path of the optical channel, the solar cell comprising one or more III-V compound semiconductor layers and capable of generating in excess of 20 watts of peak DC power; a diode mounted on the support and coupled in parallel with the solar cell; and first and second electrical contacts mounted on the support and coupled in parallel with the solar cell and the diode; and an encapsulant covering the support, the solar cell, the diode, and at least a portion of the exterior sides of the optical element. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to amplitude modulation (AM) stereo receivers, and particularly to AM stero receivers which are capable of receiving broadcast stereo signals having composite amplitude and angular modulation impressed on a carrier according to different composite modulation standards.
At least five different approaches have been proposed for the implementation of stereophonic broadcasting in connection with the existing AM radio service. See, for example, the article entitled "AM Stereo: Five Competing Options" published in the IEEE "Spectrum" magazine of June 1978, at page 24, and the public file of the Federal Communications Commission's (FCC's) Docket No. 21313, the AM Stereo Broadcasting proceeding. Each of the five systems described therein uses a different modulation technique for providing an add-on stero capability to AM transmitters and suitably equipped receivers. All five proposed systems provide a composite transmitted signal which has a compatible signal format so that existing monophonic AM receivers can detect a monophonic audio signal component from the composite signal which is transmitted in each of the systems. In addition to the monophonic signal component, receivers which are specially equipped for any one of the proposed composite modulation standards will receive a stereophonic signal component, which differentiates left (L) and right (R) audio information and can be decoded and combined with the detected monophonic signal component in order to provide stereophonic sound.
One of the proposed AM stereo systems utilizes amplitude and frequency modulation (AM/FM) to develop a composite signal for transmission. In accordance with this proposed system, a carrier is frequency modulated with information corresponding to the difference between left and right stereo audio signals (L-R). The frequency-modulated carrier is then amplitude modulated with a signal corresponding to the sum of the left and right stereo audio signals (L+R), which is equivalent to standard monophonic amplitude modulation (AM), and the resulting composite signal is broadcast. As a result, a conventional AM receiver, which utilizes an envelope detector, detects the AM or (L+R) component of the composite signal and provides monophonic reception. A specially equipped stereo receiver will also detect the frequency modulation or (L-R) component of the composite signal. The resulting (L-R) representative audio signal can be combined with the (L+R) sgnal in an additive and subtractive matrix to produce separate (L) and (R) output audio signals for stereo listening.
Another of the proposed systems utilizes phase modulation instead of frequency modulation of the carrier (AM/PM) to transmit stereo difference (L-R) information. In this system the phase-modulated carrier is then amplitude modulated with (L+R) information to develop a composite signal which is then transmitted.
Yet another of the proposed systems utilizes a modulation technique known as compatible quadrature amplitude modulation (CQUAM) to provide a modified phase modulation of a carrier with (L-R) information. The phase-modulated carrier is thereafter amplitude modulated with (L+R) information to develop a composite signal. This composite signal may also be viewed as consisting of a pair of carriers at the same frequency but separated in phase by 90 degrees (quadrature carriers), where one carrier is amplitude modulated with left (L) stereo audio information and the other with right (R) stereo information.
Still another of the proposed systems is known as the variable compatible phase multiplex (V-CPM) system and is a modified form of quadrature system. In this system two carriers at the same frequency are separated in phase by an amount which varies between 30 degrees and 90 degrees depending on the content of the audio signals being transmitted. One of these carriers is amplitude modulated with left (L) stereo audio information and the other with right (R) stereo information and the two are linearly combined. The resultant signal can be resolved into an in-phase component representative of (L+R) information and a quadrature-phase component representative of (L-R) information. (L-R) information below 200 Hz. is eliminated to provide room for a frequency-modulated, low frequency (55 to 96 Hz) pilot signal which performs two functions. It indicates the presence of a stereo broadcast, and its modulation communicates to specially equipped stereo receivers the instantaneous phase angle between the two variable-angle carriers in this system so that such receivers can track the resulting variation in phase modulation in the transmitted signal. In a corresponding stereo receiver the composite signal may be envelope detected to provide an (L+R) audio signal and quadrature synchronous detected to derive a signal which represents the (L-R) audio information. The pilot signal is separately detected and its modulation can be used to vary the gain of the (L-R) signal channel to provide the equivalent of a variable-angle receiver which tracks the broadcast signal. The resulting (L+R) and gain-controlled (L-R) signals are then combined in a conventional stereo matrix to develop (L) and (R) signals. In addition, the developer of this system has proposed a simplified receiver in which the gain of the (L-R) channel is not varied. This corresponds to receiving the variable-angle broadcast signal at a compromise fixed angle, instead of tracking the angle variation.
Finally, there is a proposed system known as the independent sideband (ISB) system. This system phase modulates the carrier with a suitably modified (L-R) signal and then amplitude modulates the phase-modulated carrier with an (L+R) signal, where the (L+R) and (L-R) signals have been phase shifted so as to be in a quadrature relationship. As a result, the lower sidebands of the resulting composite signal contain primarily left (L) stereo information whereas the upper sidebands contain primarily right (R) stereo information (hence the name "ISB"). This system is also described in the inventor's U.S. Pat. Nos. 3,218,393, 3,908,090 and 4,018,994.
The composite signal transmitted by each of the proposed systems includes a low-frequency pilot signal component for identifying the presence of a stereo broadcast. Because the pilot signal frequencies are different for each of the above-mentioned systems (AM/FM-20Hz; AM/PM-5Hz; CQUAM-25Hz; V-CPM-55 to 96 Hz; and ISB-15Hz) they also inherently identify the modulation approach used in each composite signal.
More detailed descriptions of these systems appear in the aforementioned IEEE Spectrum article, in the public file of FCC Docket 21313, and in various patents which have been issued to the proponents of these systems.
Despite significant differences in performance of the various proposed systems, the FCC has had difficulty in its attempt to choose one of these systems as the basis for a national standard for AM stereo broadcasting. As a result, the FCC is considering authorizing more than one of these systems. In this case the normal forces of free competition in the marketplace will be allowed to determine whether one of the systems will eventually become the predominant AM stereo system, or whether two or more systems can coexist.
It is, therefore, an object of the present invention to provide a receiver capable of receiving AM stereo signals which have composite modulation according to any one of two or more of the various proposed modulation techniques.
It is a further object of the present invention to provide an AM stereo receiver capable of detecting the pilot signal used in conjunction with any one of the various proposed AM stereo broadcast techniques.
It is a further object of the present invention to provide an AM stereo receiver capable of automatically distinguishing, by reason of the pilot signals, which of the various proposed modulation techniques is being used in a particular received AM stereo broadcast signal.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided in a receiver for stereophonic broadcast signals which include a modulation component comprising a pilot signal having a selected frequency characteristic, apparatus for determining the presence or absence of such pilot signals. In such apparatus there is provided means for detecting received signal components which lie within a first band of frequencies which includes said pilot signal, and for also detecting received signal components which lie within at least one other band of frequencies located above or below the first band. There is also provided means for evaluating the signals detected in such first and other bands, and for developing an output signal which indicates when signals in the first band exceed a first level and signals in the other band do not exceed a second level.
In accordance with another aspect of the present invention there is provided in a receiver for a plurality of different types of AM stereophonic broadcast signals, each of which includes a modulation component comprising a pilot signal having a selected frequency characteristic that is unique to that type of AM stereophonic broadcast signal, apparatus for determining the presence of any one of such pilot signals, thereby indicating which type of AM stereophonic broadcast signal is being received. The apparatus includes means for detecting received signal components which lie within a plurality of narrow frequency bands, each of which includes only one of said pilot signals. There is also included means for evaluating the signals detected in each of such frequency bands, and for developing an output signal which indicates when signals in one of the bands exceed a predetermined level and signals in all other bands do not exceed said level and which also indicates which of the plurality of bands such one band is, thereby indicating which type of AM stereophonic broadcast signal is then being received.
Finally, in accordance with another aspect of the present invention, there is provided a receiver for receiving and demodulating composite amplitude-modulated (AM) stereophonic broadcast signals comprising a carrier having amplitude modulation, representative of stereo sum (L+R) information, and angular modulation, representative of stereo difference (L-R) information, impressed on the carrier according to one of at least two composite modulation techniques, the angular modulation further including a pilot signal component having a selected frequency characteristic representative of such one composite modulation technique. Such a receiver includes means for receiving composite AM stereo signals and for converting such signals to corresponding intermediate frequency (IF) signals. It also includes means for amplitude demodulating said IF signal to derive therefrom a signal representative of the (L+R) information. The system also includes angular demodulating means for demodulating such IF signal according to the requirements of the first and second composite modulation techniques to develop corresponding first and second audio frequency output signals representative of (L-R) information transmitted according to such first and second composite modulation techniques. There is provided means for detecting received signal components which lie within a first narrow band of frequencies which include the pilot signal which is representative of such first composite modulation technique, and for also detecting received signal components which lie within a second narrow band of frequencies which include the pilot signal which is representative of such second composite modulation technique. The receiver also includes means for evaluating the signals detected in the first and second bands and for developing one or more output signals which indicate when signals in only one of the frequency bands exceed a predetermined level and in which of the two bands such signals lie. The receiver further includes means, responsive to the output of the evaluating means and having the first and second audio output signals supplied thereto, for passing such first or second signal only when the output of the evaluating means indicates that the corresponding pilot signal is present in the received signal. The receiver finally includes means for utilizing the (L+R) representative signal and the audio signal passed by such last mentioned means for deriving left (L) and right (R) stereo audio output signals.
For a better understanding of the present invention, together with other and further objects thereof, reference is made to the following description, taken in conjunction with the accompanying drawings, and its scope will be pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially schematic and partially block diagram of an AM stereo receiver in accordance with the present invention.
FIG. 2 is a block diagram of a pilot signal detecting apparatus in accordance with the present invention.
FIG. 3 is a block diagram of an alternative embodiment of a pilot signal detecting apparatus in accordance with the present invention.
FIG. 4 is a block diagram of another alternative embodiment of a pilot signal detecting apparatus in accordance with the present invention.
FIG. 5 is a schematic diagram of a logic circuit usable in the present invention.
FIG. 6 is a schematic diagram of another logic circuit usable in the present invention.
FIG. 7 is a partially schematic and partially block diagram of a control circuit and pilot signal detector in accordance with the present invention.
FIG. 8 is a block diagram of a pilot signal detector using a microprocessor to provide digital filtering.
DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a multi-system AM stereo receiver 10 embodying the present invention in one form. For purposes of example, receiver 10 is capable of receiving AM stereo signals incorporating three of the proposed modulation approaches: (ISB) AM stereo signals, (AM/PM) stereo signals, and (CQUAM) stereo signals. Also shown in receiver 10, indicated by dotted line connections, are additional circuit elements for receiving (AM/FM) stereo signals and (V-CPM) stereo signals, as will be further described. The receiver of FIG. 1 includes a receiving antenna 12, coupled to suitable RF, frequency translation, and IF circuitry 14, which, may be of conventional design. The IF output of unit 14 is coupled to an AM demodulator 16, which may be a conventional envolope detector or other suitable amplitude modulation detector for detecting the AM component of supplied IF signals. The output of demodulator 16 is coupled directly to gate 18 and it also coupled to gate 22 via phase shift network 20, which provides a relative phase shift of approximately 45 degrees for audio frequencies over a reasonably wide band such as 100-5000 Hz. Phase shift network 20 is required for ISB stereo signal decoding in accordance with the phase shift technique which is well understood in the art. Gate 22 is activated by an ISB control signal, designated (B), which is developed when an ISB pilot signal is detected by circuits 94, 96, as will be further described. In the absence of control signal (B), herein designated as a "zero" signal state, inverter 28 provides a signal to maintain gate 18 open, which allows the non phase-shifted output of AM demodulator 16 [representative of (L+R), or stereo sum information] to be applied to stereo matrix 30 over lead 24. When an ISB AM stereo signal is being received, control signal (B) changes to a "one" signal state which opens gate 22. Inverted control signal (B) closes gate 18, and the phase-shifted output signal from AM demodulator 16 is thereby supplied to stereo matrix 30 over lead 24.
Matrix 30 is also provided with an (L-R) stereo difference information signal over lead 32, which is developed by demodulating the IF signal from unit 14 according to the particular stereo modulation technique used in the AM stereo signal then being received, as will be further described hereinafter. Matrix 30 may be a conventional stereo matrix such as is currently used in FM stereo receivers. Matrix 30 adds and substracts the audio (L+R) and (L-R) signals thereby deriving separate (L) and (R) audio output signals which are provided on output leads 34 and 36 and may be coupled to speakers 38 and 40, respectively.
The remaining circuits of the receiver 10 include circuit portion 42 which is provided for phase demodulating received signals which have stereo difference (L-R) modulation components according to the AM/PM or CQUAM modulation techniques. Circuit portion 44 is provided for demodulating received signals which have (L-R) modulation components according to the ISB modulation technique.
Gates 46, 48 and 50 are provided with control signals (A), (C), and (B), respectively, which open the respective gates when logic circuit 96 determines that an AM/PM, CQAM or ISB AM stereo signal, respectively, is being received, based on the detection of the corresponding pilot signal. For example, if logic circuit 96 determines that an AM/PM stereo signal is being received, control signal (A) is outputed, which opens gate 46, thereby to supply a corresponding (L-R) signal to matrix 30. If logic circuit 96 determines that an ISB AM stereo signal is being received, it provides a control signal (B) to open gate 50, thereby allowing the corresponding (L-R) signal to be supplied to matrix 30. As stated previously, control signal (B) also changes the states of gates 18 and 22, thereby allowing the phase-shifted (L+R) sgnal from network 20 to be supplied to matrix 30. In the event that logic circuit 96 determines that a CQUAM stereo signal is being received, it provides a control signal (C) to open gate 48, thereby allowing the corresponding (L-R) signal to be supplied to matrix 30. In the absence of any of the control signals (A), (B) and (C), only gate 18 is open, because of inverter 28, and, therefore, the receiver provides only monophonic performance, since only an (L+R) signal is applied to matrix 30.
The receiver elements 42 for phase demodulating AM/PM stereo signals include a limiter 52, which provides appropriate limiting (for example 40 db) for received AM/PM and CQUAM composite signals. Limiter 52 effectively removes AM from the supplied IF signal and provides the limited signal (containing PM components) to discriminator 54, which performs frequency demodulation of the limited signal. The output signal from discriminator 54 is amplified in amplifier 58 and corresponds to frequency variations of the limited signal. Capacitor 56 is selected to provide an IF bypass for the output of discriminator 54. Resistor 60 and capacitor 62 form an integrating circuit which converts the frequency-demodulated signal, available at the output of amplifier 58, to a phase-demodulated signal representative of (L-R), which is then supplied, via gate 46, to matrix 30 in the event control signal (A) is present to indicate that the received signal is an AM/PM type stereo signal. The phase demodulated signal is also provided to the combination of tangent circuit 66 and multiplier 68, which modifies the phase demodulated signal as required by the CQUAM stereo technique. The reason for this modification, as well as alternative circuitry for achieving the same result, are disclosed in the references cited previously herein and in U.S. Pat. No. 4,172,966. Multiplier 68, in accordance with the teaching of that patent, is provided with an (L+R) signal derived from the output of AM demodulator 16 over lead 70. The output of Multiplier 68 is supplied to matrix 30, via gate 48 if control signal (C) is present to indicate that the received signal is a CQUAM stereo signal.
Circuit portion 44 contains components which are used in connection with the demodulation of ISB stereo signals to produce a corresponding stereo difference (L-R) signal. These components include a carrier tracking circuit 72, which regenerates the original carrier frequency signal, for example by use of one or more phase-locked loops as described more fully in the inventor's U.S. Pat. Nos. 3,973,203 and 4,081,994. The IF signal from unit 14 is coupled to carrier track circuit 72 and is also coupled to multiplier 76 wherein it is combined with a non-linear derivative of the demodulated stereo sum signal supplied from AM demodulator 16 via lead 73. The operation performed by the combination of nonlinear circuit 74 and multiplier 76 is also known as inverse amplitude modulation, or simply inverse modulation, and is more fully described in the inventor's prior U.S. Pat. No. 4,018,994. The output of multiplier 76 is combined with the regenerated carrier in a further multiplier 78, which functions as a synchronous quadrature detector and whose output is a corresponding stereo difference (L-R) signal, which is amplified in amplifier 80 for equalization with respect to the stereo sum signal (L+R) channel. However, in accordance with the phase shift technique for ISB stereo signal detection, the (L-R) signal present at the output of detector 78 must be phase shifted by 45 degrees. This is accomplished in phase shift network 86. The resulting phase shifted (L-R) signal is supplied to matrix 30 via gate 50. Gate 50 opens when provided with a control signal (B) from logic circuit 96, indicating that an ISB stereo signal is being received.
Additional circuits are shown connected by dotted lines in FIG. 1 for implementation of additional AM stereo reception capability. Lead 100 and gate 102 provide a corresponding frequency demodulated (L-R) signal to matrix 30 in the event an (AM/FM) stereo signal is being received, which is indicated when control signal (D) is outputed from logic 96. Lead 104 and quadrature detector 106 are provided for simplified fixed-angle demodulation of the (L-R) component of a V-CPM stereo signal. The output of quadrature detector 106 is supplied to amplifier 108 which provides increased amplification with respect to the stereo sum signal (L+R) channel (AM demodulator 16 and gate 18 in this case) for signal equalization. The output of amplifier 108 is provided to matrix 30 via gate 110 when control signal (E) is provided by logic circuit 96, indicating the reception of a V-CPM stereo signal.
In the foregoing description, reference has been made to the existence of different pilot signal components in the received stereo signals, which are used to determine which type of stereo signal is being received (i.e. AM/PM, CQUAM or ISB) so that appropriate demodulation circuitry may be engaged. As noted previously, each of the different AM stereo modulation techniques proposed uses a low frequency pilot signal (frequency or phase modulated on the carrier) in order to indicate to stereo receivers the presence of a stereo broadcast. Because the frequency of this pilot signal is different for each of the five AM stereo systems considered herein, the pilot signal can be used in an AM stereo receiver to identify which stereo broadcast technique is being received. As noted earlier, the AM/PM stereo system uses a pilot signal of 5 Hz in the stereo difference signal channel. The ISB system uses a 15 Hz. pilot signal, the AM/FM system uses a 20 Hz. pilot signal, and the CQUAM system uses a 25 Hz. pilot signal. Finally, the V-CPM system uses a pilot signal which varies between 55 Hz and 96 Hz. Since the V-CPM pilot signal frequencies are in the audible range, it is necessary to eliminate them from the stereo signal output of the (L-R) channel for V-CPM stereo signal reception. Accordingly, highpass filter 109 is provided in the V-CPM (L-R) signal channel portion of the multiple-system AM stereo receiver shown in FIG. 1 for passing signals above 200 Hz., for example.
The receiver 10 of FIG. 1 makes use of the various pilot signal components in received AM stereo signals to generate control signals (A), (B) and (C) [and also (D) and (E) if the additional dotted line circuitry is incorporated in the receiver]. The control signal generating circuits rely on the fact that different pilot signal frequencies are used in each of the different AM stereo systems. The control signals generated in response to reception of the different pilot signals indicate which, if any, of the AM stereo signal types is being received and activates gates 46, 48, 50, 102 or 110 according to the type of stereo signal received, thereby to couple the corresponding (L-R) stereo difference signal to matrix 30. Gates 18 and 22 are also activated by the control signal (B) to provide appropriate gating of the stereo sum signal (L+R) according to whether an ISB stereo signal, or another type of stereo signal, or a monophonic signal is being received.
The detection of the different pilot signals is performed by pilot signal detector 94 operating in conjunction with logic circuit 96, the latter of which generates the control signals (A) through (C), or (A) through (E), on corresponding separate output leads 98. The input signal for pilot signal detector 94 is taken from the output of frequency detecting circuitry 54, 56, 58, which is integrated by resistor-capacitor combination 60, 62 to provide a phase-demodulated audio signal. Since all five of the proposed AM stereo systems make use of angular modulation techniques to transmit the pilot signals, it is possible to detect the pilot signal for all systems from this phase-demodulated signal. However, the pilot signal component can be detected in any angular demodulated signal, such as the frequency-demodulated signal which exists at the output of discriminator 54 or the output of quadrature detectors 78 and 106. As used herein the term angular modulation includes both frequency modulation and phase modulation. It is recognized that all of the systems make use of slightly different forms of angular modulation for the stereo difference (L-R) signal, but the phase-demodulated signal which appears between resistor 60 and capacitor 62 will contain the pilot signal component for any of these systems, although it may be shifted in phase or amplitude with respect to the stereo difference signal (L-R) component as properly demodulated. The demodulated pilot signals are amplified by transistor 88, which is connected across low resistance load 90, and provided over lead 91 to pilot signal detector 94. This demodulated signal is also provided to start circuit 92 which detects sudden substantial changes in the output of the phase demodulation circuitry. Such changes indicate either that the receiver has initially been turned on and has started to receive a station, or that the receiver has been retuned to a different frequency in the AM broadcast band and a new station has begun to be received by the receiver. Sudden changes in the phase demodulation circuit output trigger an output signal from circuit 92, thereby starting the pilot signal detection process which is carried out by detector 94 and logic circuit 96, as will be further described. As an alternative to detecting changes in the phase demodulation output, the same result could be achieved by detecting directly the operation of the receiver's on/off and tuning controls.
Capacitor 82 comprises an IF bypass capacitor which is connected in the ISB stereo signal receiving circuit portion 44. Switch 84 is used in one embodiment to provide a timing signal for pilot signal detector 94 and makes use of capacitor 82. It will be recognized by those skilled in the art that capacitor 82 could be directly connected to the output of quadrature detector 78, in which case switch 84 could be connected to capacitor 56 or to a separate capacitor provided only for use in connection with the timing of pilot signal detector 94, as will be further described.
Referring to FIG. 2, there is shown in block diagram form a pilot signal detecting circuit 94' which is usable not only in the multiple-system AM stereo receiver of FIG. 1, but also in single system AM stereo receivers as will be described hereinafter. The output of amplifying transistor 88 in FIG. 1 is supplied over lead 91 to bandpass filters 112, 114 and 116. In a single system receiver, where only a single pilot signal must be detected, bandpass filters 112, 114 and 116 are narrowband filters arranged to pass bands of frequencies respectively below, at, and above the desired pilot signal frequency. Thus, if the circuit 94' of FIG. 2 is used to detect only an ISB AM stereo pilot signal, for example, filter 114 would be a narrowband filter which passes 15 Hz. plus and minus approximately 2.5 Hz, for example. In this case, filter 112 would be tuned below the nominal pilot signal frequency and would pass, as an example, 10 Hz. plus and minus 2.5 Hz. and filter 116 would be tuned to a frequency higher than the expected pilot signal, for example, 20 Hz. plus and minus 2.5 Hz. Each of the filters 112, 114 and 116 is coupled to a corresponding one of the detecting circuits 119, 120 and 122 and then to one of the threshold circuits 124, 126 and 128. If only a pilot signal at the nominal pilot signal frequency of 15 Hz. is present on lead 91, with sufficient amplitude, detector 120 will provide a signal which exceeds the threshold set in threshold circuit 126 and thereby sets flip-flop 132. Since it has been assumed that there are substantially no signals within the passbands of filters 112 amd 116, flip-flops 130 and 134 will not be set by the corresponding threshold circuits 124 and 128. In the event substantial noise or other spurious signals are present on lead 91, it is anticipated that the noise will be sufficiently broadband so that detectors 119, 120 and 122 will all develop sufficient output to trigger their corresponding threshold circuits 124, 126, 128, thereby setting all flip-flops 130, 132 and 134. For lower noise levels or noise having a different spectral content, only two of the flip-flops, for example 130 and 132 or 132 and 134, might be set. After a time interval sufficient for the narrowband filters 112, 114, 116 and detectors 119, 120, 122 to respond to a received pilot signal and/or noise, the logic circuit 96' evaluates the outputs of flip-flops 130, 132 and 134 and provides an output signal (B) on lead 142 indicating the existence of the desired 15 Hz pilot signal only if corresponding flip-flop 132 is set and the other flip-flops 130 and 134 are not set. In the event more than one flip-flop is set, logic circuit 96' concludes that the flip-flops were triggered by noise or other spurious signals and does not generate any output signal.
In the configuration shown in FIG. 2, the pilot signal detector 94' and logic circuit 96' also may be used for detecting three pilot signals corresponding to three of the five proposed AM stereo systems. In one embodiment, which is illustrated by the solid lines of the receiver 10 of FIG. 1, the receiver is adapted to receive three types of AM stereo transmissions. The first type, designted by control signal (A), is the AM/PM technique, which has a pilot signal frequency of 5 Hz. The second type, designated by control signal (B), is the ISB technique, which has a pilot signal frequency of 15 Hz. The third type, designated by control signal (C), is the CQUAM technique, which has a pilot signal frequency of 25 Hz. If the circuit 94' shown in FIG. 2 is to be used in connection with the detection of these three pilot signals, filters 112, 114 and 116 would be arranged to each pass only one of the pilot signal frequencies. Accordingly, filter 112 would be arranged to pass 5 Hz. plus and minus 1 Hz., filter 114 would be arranged to pass 15 Hz. plus and minus 1 Hz. and filter 116 would be arranged to pass 25 Hz. plus and minus 1 Hz. Each of the flip-flops 130, 132 and 134 would, therefore, be set by an output of threshold detectors 124, 126 and 128 which indicates the existence of the corresponding pilot signal. Again, logic circuit 96' determines which of flip-flops 130, 132 and 134 have been set and provides a control signal output on one of the control leads 140, 142 and 144 indicating the presence of one of the pilot signals only if its corresponding flip-flop has been set and the other flip-flops have not been set. If any two or more of the flip-flops are set, no output control signal is generated by logic circuit 96'. It is desirable that only by such a clear indication of a received pilot signal should receiver 10 be placed in a stereo reception mode by activation of the gate or gates corresponding to the stereo modulation technique indicated by the received pilot signal.
Logic circuit 96' is reset by the output of start circuit 92 over lead 93 as indicated in FIG. 2 and this signal is also used to reset flip-flops 130, 132 and 134. Logic circuit 96' is also provided with a timing signal T3 which indicates the time at which the outputs of flip-flops 130, 132 and 134 should be evaluated, as will be further explained. Output 136 from logic circuit 96' may be provided to indicate that no clear decision has been made that any of the pilot signals has been received, thereby to cause receiver 10 to operate in its monophonic mode. Logic circuit 96' also includes an output lead 138 which is connected to stereo indicator lamp 139. Circuit 96' provides a signal on lead 138 whenever any one of the control signals (A), (B) or (C) is generated.
FIG. 3 is a block diagram of an alternative embodiment of a pilot signal detector and logic circuit in accordance with the present invention. The pilot signal detecting circuit embodiment 94, shown in FIG. 3, is useful in connection with detecting pilot signals for as many as all five of the AM stereo broadcast systems described previously herein. Referring to FIG. 3, there is shown a control circuit 146 which receives a start signal from start circuit 92 over lead 93. The control unit 146 provides control signals to a voltage-controlled, narrowband bandpass filter 148, to threshold detector 150, to flip-flops 152, 154, 156, 158 and 160, and to logic circuit 96. The control voltage supplied to filter 148 initially sets this filter to the frequency of a first pilot signal, for example the 5 Hz. pilot signal of the AM/PM stereo system. The filter is held at the 5 Hz. frequency for a sufficient period to provide an output to threshold detector circuit 150, for example 300 milliseconds. Circuit 150 detects the signal present at the output of filter 148 and compares the detected signal with an adjustable threshold which is set by the control signal from Unit 146. Flip-flop 152 is conditioned to respond to the output of threshold detector 150 during this initial period, and if the output of filter 148 triggers threshold detector 150 during this initial first sampling period, flip-flop 152 will be set. Control logic 146 provides a control signal to flip-flop 152 to enable it only during this first period.
Subsequent to the 5 Hz. sampling by filter 148 during the first period, control circuit 146 provides a different control signal voltage to controllable bandpass filter 148 to reset it at a second frequency, for example the 15 Hz. pilot signal frequency used in the ISB stereo system. Control circuit 146 may also provide a control signal to threshold detector 150 to adjust its threshold level to correspond to the anticipated strength of the ISB pilot signal. Threshold detector 150, if it detects a 15 Hz signal during this second sampling period, sets flip-flop 154, which is enabled, or conditioned to be set, only during this second sampling period by control circuit 146.
At the end of the second period, control circuit 146 resets bandpass filter 148 to the next pilot signal frequency, for example the 20 Hz. pilot signal of the AM/FM stereo system. Flip-flop 156 is set if a 20 Hz. signal is detected by threshold detector 150 during the third sampling period. Similarly flip-flops 158 and 160 are set if the threshold detector 150 detects signals during the fourth and fifth sampling periods, when the bandpass filter 148 is tuned to the 25 Hz. pilot signal used in the CQUAM stereo system and then to the 55 to 96 Hz. variable frequency signal used in the V-CPM stereo system, respectively. Alternatively, because of the wider bandwidth required it may be necessary to gate in a separate filter to detect the variable frequency pilot signal used in the V-CPM system.
After sequentially sampling the different frequency bands for the five different pilot signals during five consecutive periods and setting of flip-flops 152, 154, 156, 158 and 160 according to whether or not a signal is detected in each of the pilot signal passbands, logic circuit 96 is activated by a timing signal T3 to enable the logic circuit to evaluate the outputs of flip-flops 152, 154, 156, 158 and 160. Logic circuit 96 operates in a manner similar to the logic circuit 96' shown in FIG. 2 and provides output signals (A), (B), (C), (D) and (E) on leads 98 to operate the corresponding gates in receiver 10 of FIG. 1 in the event one, and only one, pilot signal has been detected as being present during the first five sampling periods. In addition, a separate signal is also provided on lead 138 in this case to activate stereo indicator lamp 139. If signals in more than one of the pilot signal bands are detected, the result indicates an ambiguity as to which AM stereo modulation technique is present in the received IF signal or that significant noise or other spurious signals are present. Accordingly, under this condition logic circuit 96 will not provide any output on any of the leads 98 and 138, and stereo indicator lamp 139 will not be lit. Receiver 10 will, therefore, operate in the monophonic mode until such time as a single pilot signal has been detected during a complete sampling cycle.
It will be recognized that the circuit 94 in FIG. 3 operates by sequential sampling of different frequency bands whereas circuit 94' in FIG. 2 operates to simultaneously sample all of the frequency bands of interest. Those skilled in the art will recognize that either sequential or simultaneous sampling can be used for detecting one or more of the different pilot signals. Following the initial sampling by logic circuit 96 of all of the outputs of the flip-flops in FIG. 3, if no single pilot signal has been determined to be present, it may be desirable to reset control circuit 146 and repeat the pilot signal detection process once or a few times. Once only a single pilot signal has been detected during a sampling cycle, the re-cycling can be stopped. This function can be implemented, for example, by feedback to control circuit 146 from logic circuit 96.
FIG. 4 illustrates another pilot signal detecting and logic circuit arrangement which makes use of a programmed microprocessor to perform the logic functions described with respect to FIGS. 2 and 3. Start circuit 92 provides an initiation signal to microprocessor 162, which thereafter controls variable bandpass filter 148 and threshold detector 150 to provide sequential sampling of the various pilot signal frequency bands as described with reference to FIG. 3. The output of threshold detector 150 for each frequency band can be examined by microprocessor 162 and the result stored therein for later analysis to determine whether one and only one pilot signal has been detected during a sampling cycle.
In FIG. 8 there is illustrated another pilot signal detector and logic circuit arrangement which makes use of a microprocessor for the narrowband filtering function as well as for the logic functions. Lead 91 carrying the phase-detected pilot signals is coupled to amplitude detector 280, which may include a low pass filter to remove higher frequency audio modulation components. Detector 280 supplies the detected output to integrator 282, which averages this signal over a suitable time interval (1 to 10 milliseconds, for example), also removing high frequency components. The integrator output is converted to a digital signal for each time interval by analog-to-digital converter 284, and the digitized signal level is provided to microprocessor 286 for analysis. The microprocessor may perform a digital filtering function by taking weighted sums of the digitized detected signal for the various pilot signal frequencies and comparing these weighted sums to preselected threshold values to determine presence or absence of the particular pilot signal or signals of interest. An advantage of this embodiment of the invention is that analog to digital converter 284 need only handle one polarity of signal, thereby simplifying the design of block 284. However, a preferred arrangement would be to delete detector 280 and integrator 282, convert the signal on lead 91 directly into digital form in A-to-D converter 284 and then do all of the signal processing digitally in microprocessor 286. By following this procedure one avoids the generation of undesired nonlinear products which are often introduced by the action of detector 280.
In FIGS. 3 and 4, there is shown a control lead from control circuit 146 or microprocessor 162 to threshold detector 150. This control lead is used to appropriately adjust the threshold level of the threshold detector in order to compensate for expected differences in signal strength among the various pilot signals, resulting from the fact that different amounts of angular modulation are used in developing the various AM stereo broadcast signals. This will become clear to those skilled in the art from an examination of the broadcast signal specifications which have been published for each of the proposed AM stereo systems.
FIG. 5 is a circuit diagram of a logic circuit 96' which is usable in connection with the pilot signal detecting arrangement of FIG. 2 for the purpose of detecting the presence of a single pilot signal and the absence of signals in adjacent frequency bands. As previously described with respect to FIG. 2, for the detection of a single pilot signal, for example the ISB pilot signal, flip-flops 130, 132 and 134 are set according to whether signals have been detected at frequencies below, at, and above the frequency of the expected pilot signal. Assuming that the desired pilot signal has been received, and no signal has been detected in the frequency bands above and below the pilot signal frequency, flip-flop 132 would be in a set condition, while flip-flops 130 and 134 would not be set. The set condition of flip-flop 132 causes a reverse bias on diode 166 which raises the output level on lead 184 to indicate a binary "one", provided that flip-flop 180 is in a set condition and transistor 176 is not conducting as hereinafter will be described. In the event that there is a "one" output from flip-flop 130 or 134, the high output will be conducted through diodes 170 or 172 and through resistor 174, and thereby cause transistor 176 to conduct. This will lower the output on lead 184 to a "zero" signal condition. This condition occurs if there is a signal detected in the frequency band either below or above the frequency band of the pilot signal of interest, and would be indicative that the signal which set flip-flop 132 might have been caused by noise. Flip-flop 180 is cleared by the start signal on lead 93 which is supplied from circuit 92. While cleared, diode 178 conducts, and the output on lead 184 is a "zero". Flip-flop 180 is set by timing signal T3, indicating that the time for sampling the three frequency bands has been completed. When flip-flop 180 is set, diode 178 is reverse biased, and a "one" output on lead 184 is supplied, provided that a "one" is present at the output of flip-flop 132. Amplifier 182 is connected to lead 184 to drive stereo indicating lamp 139. Circuit 164 therefore operates to provide a "one" output on lead 184, indicated by a positive voltage, in the event that flip-flop 132 is set and flip-flops 130 and 34 are not set. The output on lead 184 is enabled after timing signal T3 is provided to flip-flop 180.
FIG. 6 is a more complex logic circuit arrangement for use in connection with the detection of any one of three different pilot signals. For example, this logic circuit can be used in connection with the receiver of FIG. 1 when arranged to receive an AM/PM stereo signal, with a pilot signal of 5 Hz., an ISB stereo signal, with a pilot signal of 15 Hz. or a CQUAM stereo signal, with a pilot signal of 25 Hz. Flip-flops 130, 132 and 134 are controlled by simultaneous or sequential operating bandpass filters and threshold detecting circuits (such as are shown in FIGS. 2 and 3) tuned to the 5 Hz., 15 Hz. and 25 Hz. pilot signal frequencies.
If flip-flop 130 is in a "one" condition, indicating the reception of a pilot signal at 25 Hz., and flip-flops 132 and 134 have a "zero" output, indicating no reception of pilot signals or other signals at 15 and 25 Hz., output lead 140 corresponding to control signal (A) is enabled. The positive output of flip-flop 130 reverse biases diode 186. Diode 202 is reverse biased, provided that one of transistors 198, 216 or 218 are conducting. Each of these transistors is conducting only if two of the flip-flop outputs have a "one". For example, transistor 198 has its base connected through diodes 192 and 194 to the outputs of flip-flops 130 and 132. These diodes are also connected to a positive voltage source through resistor 196. In the event both flip-flops 130 and 132 have a "one" output, both of these diodes will be reverse biased, and transistor 198 will conduct causing diode 202 to conduct and bring the output on lead 140 to the "zero" state. Likewise, transistor 216, which has its base connected to the positive voltage supply by resistor 212 and connected to the outputs of flip-flops 130 and 134 by diodes 204 and 206, will conduct in the event that both flip-flops 130 and 134 have a positive voltage or "one" output. Also transistor 218, which is connected through its base to the positive voltage supply by resistor 214 and to the outputs of flip-flops 132 and 134 through diodes 208 and 210, will conduct if the outputs of both flip-flops 132 and 134 have a positive "one" signal. Thus the combination of transistors 198, 216 and 218 will bring down the voltage through diode 202 in the event that any pair of two flip-flops have a "one" output. This provides the output lead 140 with a "zero" output in the event that any pair of flip-flops have a "one". The output control signals (B) and (C) on leads 142 and 144 are likewise connected to these transistors by diodes 220 and 222, and connected to their respective flip-flops 132 and 134 through diodes 188 and 190. Accordingly, each of the output leads 140, 142 and 144 will be enabled if, and only if, its corresponding flip-flop 130, 132 and 134 has a "one" output, and all other flip-flops have a "zero" output.
The circuit of FIG. 6 also includes circuit elements for providing a stereo indicator output. The outputs of all three flip-flops 130, 132 and 134 are connected over diodes 224, 226 and 228 through resistor 238 to transistor 234. In the event that any of the flip-flops 130, 132 and 134 has a "one" output, and the base of transistor 234 is not brought down by the operation of flip-flop 180, through diode 230, as previously described, transistor 234 will conduct. This applies a low voltage input to transistor 232, which is otherwise in a conducting state by reason of the voltage provided from a positive voltage supply through resistor 236. Transistor 232 therefore shuts off, allowing the voltage on lead 241 to go high. This voltage will go high provided that none of transistors 198, 216 and 218 brings the voltage low, as previously described, and there is provided an output signal on lead 241 in the event that any one of the stereo system pilot signals, and no other pilot signals, have been detected. The output on lead 241 is provided over driver 242 to stereo indicator lamp 139. An inversion circuit 244 may also be provided to give an output signal indicating monophonic reception on lead 136. As previously described, flip-flop 180 operates in conjunction with diode 230 to hold the input to transistor 234 at a low condition until the completion of the pilot signal detection cycle time as indicated by timing signal T3.
As previously mentioned in connection with FIG. 1, capacitor 82, which serves as an IF bypass capacitor for the stereo channel, can also be used in connection with switch 84 to provide timing signals for the operation of pilot signal detector 94 and logic circuit 96. FIG. 7 is a diagram illustrating the operation of this type of timing circuit. Switch 84 has one pole connected to the output of quadrature detector 78 and another pole connected through resistor 246 to a positive voltage supply. The output of switch 84 is connected to bypass capacitor 82. During normal stereo reception, switch 84 is in the left position and connects bypass capacitor 82 to the output of quadrature detector 78 for IF bypass. When start circuit 92 indicates a sudden change in the output from the discriminator 54 and integrator circuit 60, 62, a start signal is provided to switch 84 on lead 93, which operates the switch so as to couple capacitor 82 to resistor 246 and the positive voltage supply. This connection to resistor 246 applies a ramp voltage to lead 248 which is supplied to threshold circuits 250, 252 and 254. The start signal is also applied to tunable bandpass filter 256 at the input designated f1 to reset the bandpass filter to the first frequency band to be sampled. When the voltage ramp on lead 248 reaches a first threshold condition designated (e1), threshold circuit 250 is triggered providing an output (T1) to bandpass filter 256 to change the filter center frequency to (f2) corresponding to a second pilot signal frequency. The signal is also provided over lead 258 to gate 260 which connects resistor 270 into threshold circuit 268, to lower the threshold thereof. For example, in a system for detecting the 5 Hz., 15 Hz. and 25 Hz. pilot signals it is appropriate to lower the threshold value, thereby increasing the threshold circuits sensitivity, for reception of the weaker 15 Hz. and 25 Hz. pilot signals. At some later time, the voltage ramp on lead 248 reaches the second threshold (e2), triggering threshold circuit 252 which provides an output (T2) which changes bandpass filter 256 to the third frequency designated (f3). At still a later point in time, the voltage on lead 248 reaches a value (e3) triggering threshold circuit 254 which provides an output (T3), which causes switch 84 to revert to the IF bypass condition for the detection of stereo difference signals in the ISB channel, and also provides a reset for start circuit 92. An appropriate value for the timing, determined by the voltage ramp on lead 248, is approximately 300 milli-seconds from the occurrence of the start signal to the output of the (T1) signal, another 300 milliseconds to the output of the (T2) signal, and still another 300 milliseconds to the output of the (T3) signal. These time periods should provide an adequate time for the passing of signals through bandpass filter 256, to phase splitter 262, diode detectors 264 and 266, and threshold circuit 268.
As has been previously described, following the output of the (T3) signal, in the event that a single stereo pilot signal has been correctly identified, the stereo indicator signal will reset the operation of start circuit 92. If, however, a stereo pilot signal has not been correctly identified, start circuit 92 may be caused to restart the search cycle for stereo pilot signals. Alternatively, only one or a selected number of search cycles can be made, and the receiver operated in the monophonic mode if a pilot signal has not been detected. The receiver can be left in the monophonic mode until returned to another AM station, or until turned off, or until some selected period of time has elapsed after which another search cycle can be initiated. This is simply a matter of choice for the designer of a specific receiver, and its implementation will be obvious to those skilled in the art in light of the disclosure set forth herein.
In various examples set forth above, there have been described specific embodiments for practicing the present invention by use of both analog ramp voltages and digital timing signals. Those skilled in the art will recognize that these signal formats can be used in varying embodiments of the present invention, and they are presented for example only, and not by way of limitation. Likewise, those skilled in the art will recognize that the specific logic circuits, such as described in FIGS. 5 and 6 are given as examples only and may be replaced with integrated circuits or other logic elements which perform equivalent functions.
It will also be recognized by those skilled in the art, that the preferred embodiments of the receiver shown in solid lines in FIG. 1, which is capable of receiving AM/PM stereo signals, CQUAM stereo signals, and ISB stereo signals, may be arranged to receive any two or more of the five different proposed AM stereo signals described herein, and such modifications and variations are deemed to be within the scope of the present invention as set forth in the claims.
While there have been described what are believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as fall within the true scope of the invention. | A stereo receiver is described which is capable of receiving any two or more of the five currently proposed AM stereo system broadcast signals. The multisystem receiver includes circuitry which is used in various configurations to demodulate the stereo signal components from broadcast signals of any one of two or more of the proposed systems. Selection of appropriate elements of the receiver's circuitry for demodulating any one of the received signals is performed automatically in response to the detection of the presence of a corresponding pilot signal which is unique for each of the five different AM stereo systems that have been proposed. The receiver includes apparatus which detects the presence of such pilot signals and controls the automatic switching of such receiver circuitry. Also described is the application of such apparatus for reliably detecting the presence of the desired pilot signal in a single system stereo receiver. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
The present application represents a divisional application of U.S. patent application Ser. No. 13/469,121 entitled “METHOD FOR DETECTING SATELLIZATION SPEED OF CLOTHES LOAD IN A HORIZONTAL AXIS LAUNDRY TREATING APPLIANCE” filed May 11, 2012, currently allowed. The present application claims the benefit of U.S. Provisional Patent Application No. 61/577,831, filed Dec. 20, 2011, which is incorporated herein by reference in its entirety.
BACKGROUND
Laundry treating appliances, such as clothes washers, may include a perforate rotatable drum or basket positioned within an imperforate tub. The drum may at least partially define a treating chamber in which a laundry load may be received for treatment according to a selected cycle of operation. During at least one phase of the selected cycle, the drum and laundry load may be spun about a rotational axis at a predetermined high speed, sufficient to centrifugally force and hold the laundry load against the perimeter of the treating chamber, causing liquid to be removed from the laundry load. This speed may be referred to as the “satellization” speed.
Known methodologies may provide an estimate of satellization speed based upon a determination of laundry load inertia or mass, or the employment of an iterative process of drum rotation. However, these methods may be inaccurate, or inefficient. It would be advantageous to efficiently determine the satellization speed accurately for a selected laundry load.
BRIEF DESCRIPTION OF THE INVENTION
According to an embodiment of the invention, a method of operating a laundry treating appliance is disclosed. The laundry treating appliance may include a rotatable treating chamber for receiving a laundry load for treatment, and a motor for rotating the treating chamber. The method may include accelerating the rotational speed of the treating chamber from a non-satellizing speed to a satellizing speed by increasing the rotational speed of the motor; generating a first torque signal indicative of the motor torque over time for at least a portion of the accelerating; comparing the shape of the first torque signal to the shape of a second torque signal indicative of rotating the treating chamber when the laundry load is satellized within the treating chamber; and determining the laundry load is satellized when the shape of the first torque signal matches the shape of the second torque signal.
According to another embodiment of the invention, a laundry treating appliance for automatically treating a laundry load according to at least one cycle of operation is disclosed. The laundry treating appliance may include a rotatable treating chamber for receiving the laundry load for treatment; a motor for rotating the treating chamber; a speed sensor outputting a speed signal indicative of the rotational speed of the motor; a torque sensor outputting a torque signal indicative of the torque of the motor; and a controller operably coupled to the motor and receiving the speed signal and torque signal. The controller may provide an acceleration signal to the motor to increase the rotational speed of the motor to accelerate the rotational speed of the treating chamber from a non-satellizing speed to a satellizing speed. The controller may also determine that the treating chamber has reached the satellizing speed by determining when the shape of at least a portion of the torque signal matches a corresponding portion of a reference torque signal, which is indicative of the torque when the laundry load is satellized.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a vertical sectional view of a laundry treating appliance in accordance with an exemplary embodiment of the invention.
FIG. 2 is a schematic view of a control system comprising a part of the laundry treating appliance illustrated in FIG. 1 .
FIGS. 3A-C are schematic views of the rotation of a laundry load in a rotating drum for increasing drum rotation speeds, where the motion of the laundry changes from tumbling ( FIG. 3A ) to satellized ( FIG. 3C ).
FIGS. 4A-B are graphical representations of a sinusoidal reference torque curve and an actual torque curve for a rotating laundry load at an increasing drum rotation speed.
FIGS. 5A-C are graphical representations of a reference torque curve and an actual torque curve in raw form, in reference, scaled, and biased form, and in reference, scaled, biased, and shifted form.
FIGS. 6A-C are graphical representations of a reference torque curve and an actual torque curve in reference, scaled, biased, and shifted form, in reference, scaled, biased, shifted, and frequency adjusted form based upon 100 data samples per cycle, and in reference, scaled, biased, shifted, and frequency adjusted form based upon 200 data samples per cycle.
FIGS. 7A-B are graphical representations of an array of data points representing actual torque and an array of reference torque data points twice the number of the actual torque data points.
FIGS. 8A-C are graphical representations of a reference torque curve and an actual torque curve generated during an exemplary 4 th drum revolution ( FIG. 8A ), an exemplary 5 th drum revolution ( FIG. 8B ), and an exemplary 6 th drum revolution ( FIG. 8C ), illustrating a comparison metric that decreases to a value below a threshold value as the reference torque curve and actual torque curve become coincidental.
DETAILED DESCRIPTION
FIG. 1 is a schematic view of a laundry treating appliance 10 according to an embodiment of the invention. The laundry treating appliance 10 may be any appliance which performs a cycle of operation to clean or otherwise treat items placed therein, non-limiting examples of which include a horizontal or vertical axis clothes washer; a combination washing machine and dryer; a tumbling or stationary refreshing/revitalizing machine; an extractor; a non-aqueous washing apparatus; and a revitalizing machine. Exemplary embodiments of the invention will be described herein in the context of a horizontal axis clothes washing machine.
The laundry treating appliance 10 is illustrated in FIG. 1 as including a structural support system comprising a cabinet 12 defining a housing within which a laundry holding system may reside. The cabinet 12 may be a housing having a chassis and/or a frame, defining an interior enclosing components typically found in a conventional washing machine, such as motors, pumps, fluid lines, valves, controls, sensors, transducers, and the like. Such components will not be described further herein except as necessary for a complete understanding of the invention.
The laundry holding system may comprise a tub 14 supported within the cabinet 12 by a suitable suspension system 16 , and a drum 18 provided within the tub 14 defining at least a portion of a laundry treating chamber 20 . The drum 18 may include a plurality of perforations 22 such that liquid may flow between the tub 14 and the drum 18 through the perforations 22 . A plurality of baffles 24 may be disposed on an inner surface of the drum 18 to lift a laundry load 26 received in the treating chamber 20 while the drum 18 rotates. It is also within the scope of the invention for the laundry holding system to comprise only a tub, with the tub defining the laundry treating chamber.
Other known components may include a door 28 which may be movably mounted to the cabinet 12 to selectively close both the tub 14 and the drum 18 . A bellows 30 may couple an open face of the tub 14 with the cabinet 12 , with the door 28 sealing against the bellows 30 when the door 28 closes the tub 14 .
The suspension system 16 may include one or more suspension elements, such as springs, dampers, lifters, cushions, bumpers, and the like, for dynamically suspending the laundry holding system within the structural support system.
The laundry treating appliance 10 may also include a wash aid dispensing system 32 , a liquid distribution system 34 , a liquid recycling/disposal system 36 , and a drum drive system 40 , which will be described further only as necessary for a complete understanding of the invention.
The drum drive system 40 , for rotating the drum 18 within the tub 14 may include a motor 42 , which may be directly coupled with the drum 18 through a drive shaft 44 to rotate the drum 18 about a rotational axis during a cycle of operation. The motor 42 may be a brushless permanent magnet (BPM) motor. Other motors, such as an induction motor or a permanent split capacitor (PSC) motor, may also be used. The motor 42 may rotate the drum 18 at various speeds in either rotational direction.
The laundry treating appliance 10 may include a control system 50 for controlling the operation of the laundry treating appliance 10 to implement one or more cycles of operation. The control system 50 may include a controller 52 located within the cabinet 12 and a user interface 54 that is operably coupled with the controller 52 . The user interface 54 may include one or more knobs, dials, switches, displays, touch screens and the like for communicating with the user, such as to receive input and provide output. The user may enter different types of information including, without limitation, cycle selection and cycle parameters, such as cycle options. The controller 52 may control the operation of the laundry treating appliance 10 utilizing a selected motor-control process, such as a closed loop speed control process.
As illustrated in FIG. 2 , the controller 52 may be provided with a memory 56 and a central processing unit (CPU) 58 . The memory 56 may be used for storing the control software that is executed by the CPU 58 in completing a cycle of operation using the laundry treating appliance 10 and any additional software, plus motor torque signals and reference torque signals. Examples, without limitation, of cycles of operation include: wash, heavy duty wash, delicate wash, quick wash, pre-wash, refresh, rinse only, and timed wash. The memory 56 may also be used to store information, such as a database or table, and to store data received from one or more components of the laundry treating appliance 10 that may be communicably coupled with the controller 52 . The database or table may be used to store the various operating parameters for the one or more cycles of operation, including factory default values for the operating parameters and any adjustments to them by the control system or by user input.
The controller 52 may be operably coupled with one or more components of the laundry treating appliance 10 for communicating with and controlling the operation of the components to complete a cycle of operation. For example, the controller 52 may be operably coupled with the wash aid dispensing system 32 , the liquid distribution system 34 , the liquid recycling/disposal system 36 , the drum drive system 40 , valves, diverter mechanisms, flow meters, and the like, to control the operation of these and other components to implement one or more of the cycles of operation.
One or more sensors and/or transducers, which are known in the art, may be provided in one or more of the systems of the laundry treating appliance 10 , and coupled with the controller 52 , which may receive input from the sensors/transducers. Non-limiting examples of sensors that may be communicably coupled with the controller 52 include a treating chamber temperature sensor, a moisture sensor, a load sensor 60 , a wash aid sensor, and a position sensor, which may be used to determine a variety of system and laundry characteristics, such as laundry load inertia or mass. Motor speed and motor torque may be represented by outputs provided by the motor 42 , or may be provided by a motor speed sensor 62 and motor torque sensor.
A summary of the disclosed method may be described as follows. During a cycle of operation, the drum 18 may be accelerated one or more times to remove liquid from the laundry load 26 . During the acceleration of the drum 18 , the motor torque may be sampled over each drum revolution and compared to one period of a reference sine wave. A metric may be developed that quantifies a variation in a torque sample buffer relative to the reference sine wave signal. The metric may be devised to be a function of the variation, such that a change in the variation, results in a change in the metric. For simplicity, it is contemplated that an increase in the variation will result in an increase in the metric. The speed at which the laundry load 26 becomes completely satellized may be determined by monitoring the metric for each drum revolution, and comparing it to a preselected threshold metric value. Load satellization may be indicated once the metric drops below the threshold value.
At drum rotational speeds lower than the satellization speed, as illustrated in FIG. 3A , some or all of the laundry load 26 may be tumbling. At this speed, illustrated in FIG. 4A , the motor torque signal 66 may have high-frequency components 68 , 70 , 72 , 74 effectively superimposed on a generally sinusoidal reference drum frequency signal 76 , which may be the result of portions of the laundry load following a trajectory inside the drum 18 that is shorter than one full drum revolution ( FIG. 3A ). As the rotational speed increases, and a larger percentage of the load is forced against the interior of the drum 18 ( FIG. 3B ), the torque signal 66 may trend toward a sinusoid, e.g. between the 4th and 6th time interval or drum revolution of FIG. 4A , having a frequency approaching the drum frequency 76 , and may have fewer high-frequency components. As the drum speed reaches, and then exceeds, the satellization speed ( FIG. 3C ), the torque signal 66 may develop into a sine wave having a frequency matching the drum rotational frequency, the magnitude of which may be proportional to the degree of off-balance of the laundry load in the drum 18 .
This behavior of the torque signal 66 may be attributed to the orientation of a horizontal axis drum 18 , and an interaction between a laundry load 26 and a closed loop speed controller. When the drum 18 is stationary, a wet load may rest on the bottom of the drum 18 . A typical speed profile, illustrated in FIG. 4B , utilized to distribute laundry items about the interior of the drum 18 may be a ramp 80 accelerating at a fixed rate from about 40 RPM to about 100 RPM. As the speed increases, the combination of friction and baffles 24 along the interior perimeter of the drum 18 may catch some of the laundry load 26 and lift it up along the side of the drum 18 until portions of the load separate from the drum 18 and drop back to the bottom.
A mass of laundry along the interior perimeter of the drum wall may change the balance of the drum 18 , which may cause a somewhat reduced drum speed. In order to track a selected speed profile target as closely as possible, the speed controller may increase the motor torque. When a laundry load portion separates from the drum wall, the speed may increase slightly, leading the controller 52 to call for a reduced torque to appropriately regulate the speed. This repeated variation in torque and/or speed may cause a relatively high-frequency torque ripple that may be observed at rotational speeds less than the satellization speed.
As the selected speed profile continues, the drum 18 accelerates, and through the combined effect of the baffles 24 and drum wall friction, the laundry load may accelerate as well. The uncontrolled process of laundry load portions adhering to and separating from the interior of the drum 18 may continue until the laundry load has achieved a high enough rotational speed that centrifugal force overcomes the force of gravity at the top of the drum 18 , and the load remains distributed along the drum wall through a complete revolution of the drum 18 . Centrifugal force (CF) is a function of a mass (m) of an object, e.g. a laundry item, an angular velocity (w) of the object, and a distance, or radius (r) at which the object is located with respect to an axis of rotation (X), or a drum axis. Specifically, the equation for the centrifugal force (CF) acting on a laundry item within the drum 18 is:
CF= m*ω 2 *r
The centrifugal force (CF) acting on any single item in the laundry load may be modeled by the distance the center of gravity of that item is from the axis of rotation (X) of the drum 18 . Thus, when the laundry items are stacked upon each other, which is often the case, those items having a center of gravity closer to the axis of rotation (X) experience a smaller magnitude centrifugal force (CF) than those items having a center of gravity farther away. It is possible to control the speed of rotation of the drum 18 such that the closer items will experience a centrifugal force (CF) less than 1 G, permitting them to tumble, while the farther away items still experience a centrifugal force (CF) equal to or greater than 1 G, retaining them in a fixed position relative to the drum 18 .
Momentum may also urge the laundry load to travel a complete revolution across the top of the drum 18 at slightly lower speeds than the satellization speed. While some portions of the load may remain against the drum wall, the radius of rotation for other, tumbling portions may decrease. Thus, the tumbling portions must be rotated at a higher speed to overcome gravity. For example, if a 4-inch thick layer of laundry load is distributed about the inside perimeter of the drum 18 , the speed required to satellize any tumbling items may be approximately 15 RPMs higher than if the drum 18 were empty.
The following equation may define the torque, T, for a fully satellized laundry load:
T=J{dot over (ω)}+Cω+D+A cos(θ DRUM )+ B sin(θ DRUM ),
where
T: Torque, J: Inertia, C: Viscous damping coefficient, D: Coulomb friction torque, ½√{square root over (A 2 +B 2 )}: Unbalance torque amplitude, and θ DRUM : Drum position.
For a fixed speed, viscous damping coefficient, and coulomb friction coefficient, the torque equation may simplify to the following:
T=K 1 +A cos(θ DRUM )+ B sin(θ DRUM ),
where
K 1 =Cω+D, {dot over (ω)}=0, T=K 1 +√{square root over (A 2 +B 2 )}*sin(θ DRUM +π/4), T=K 1 +K 2 sin (θ DRUM +φ), and K 2 =√{square root over (A 2 +B 2 )}.
The position of the drum may be a function of time:
θ DRUM =ω*t.
Therefore, the torque may be a function of time:
T ( t )= K 1 +K 2 sin(ω* t +φ).
As may be recognized, the torque may be a sinusoid with a DC offset K 1 , amplitude K 2 , and frequency co, which is equal to the drum frequency in radians per second.
For a constant acceleration, the torque equation may include an additional speed dependency as follows:
T=J {dot over (ω)}+ Cω+D+K 2 sin(θ DRUM +φ), and
T=Cω+K 1 +K 2 sin(θ DRUM +φ),
where
K 1 =J {dot over (ω)}+ D.
In the case of constant acceleration, the drum speed and drum position are functions of time as follows:
ω( t )= t *RR+ω(0),
where
RR=ramp rate (rad/sec), ω(0)=speed at t=0, θ DRUM (t)=∫ 0 t ω(τ)dτ, θ DRUM (t)=∫ 0 t (τ*RR+ω(0))dτ, θ DRUM (t)=½t 2 *RR+ω(0)* t , and T(t)=C(t*RR+ω(0))+K 1 +K 2 sin(½t 2 *RR+ω(0)*t+φ).
The objective of the algorithm is to detect the speed at which a particular laundry load may become satellized while the drum is accelerating at a constant ramp rate. The fact that the torque signal becomes a sinusoid with a single frequency matching the drum speed at or above satellization speed may be the basis for the algorithm. The algorithm may be based upon determining how much the torque signal differs from one period of a sinusoid for each drum revolution.
The torque signal may be sampled with a fixed sampling rate and stored in a buffer memory. The length of the buffer memory may be sufficient to hold enough sampling data for one complete drum revolution at a lowest speed of interest. For example, the fixed sampling rate may be 100 Hz, and the lowest drum speed of interest may be 45 RPM. One drum revolution at 45 RPM may take 1.33333 seconds, so sampling every 0.01 second may require 134 samples. Thus, the maximum buffer length required may be 134.
The algorithm may be intended to be implemented in embedded code. Moreover, because the sine function may be unavailable to recall during data sampling, one period of a normalized sine wave may be generated from a fixed number of samples, and stored in memory ahead of time. More sampling data may enable higher resolution, but at the expense of more memory. This array of a fixed number of samples from a normalized sine wave may be referred to as a “reference signal,” and may be expressed as follows:
Ref ( n ) = sin ( 2 π * n L ) ,
where
nε{0, 1, 2, 3, . . . L−1}, and L=length of reference array.
The length of the reference array may be at least twice the length of the torque buffer array to assure sufficiently high resolution when selecting the samples from the reference array to compare to each sample in the torque array.
The torque signal from the equation for T(t), above, may be in continuous time, and the process of sampling with a fixed sampling period, T s , may have the following effect on the equation:
t=k*T s ,
where
kε{0, 1, 2, 3, . . . L−1}, and T ( kT s )= C ( kT s *RR+ω(0))+ K 1 +K 2 sin G (½( kT s ) 2 *RR+ω(0)* kT s +φ).
For low speeds, the viscous damping coefficient may be very small, and over one period of the sine wave, (kT s *RR) may be a small number, so that the expression C(kT s *RR+ω(0)) may be simplified to (C*ω(0)). This term may be grouped with K 1 so that the equation may simplify to the following:
T ( kT s )=δ+ K 2 sin(( kT s *RR+ω(0))* kT s +φ),
where
δ= C *ω(0)+ K 1 .
In order to compare the torque signal to the reference signal there are 3 characteristics of the sampled torque signal that are useful to determine: a constant offset (δ), an amplitude (K 2 ), and a phase (φ). If these 3 parameters are determined, the reference signal may be scaled by K 2 , biased by δ, and shifted by φ. In the following example, δ=1, K 2 =4, and φ=π/4.
FIG. 5A illustrates a raw reference signal 82 and a torque signal 84 . FIG. 5B illustrates a scaled and biased reference signal 86 and a torque signal 88 . FIG. 5C illustrates a scaled, biased, and shifted reference signal 90 and a torque signal 92 .
FIG. 5C illustrates the torque signal 92 initially matching the reference signal 90 well, but as time progresses, the torque signal 92 may lead the reference signal 90 . This is the result of the torque sine wave frequency increasing at a constant rate as the drum speed increases at a constant rate. In this example, the ramp rate is 5 RPM per second (0.0833 Hz/s), and at the end of the cycle, the torque signal frequency is about 8% higher than the reference signal.
To account for an increasing frequency of the torque signal, the sampling data from the reference array may be selected at an increasing time interval. To determine the correct relationship, the expressions for the torque and reference array may be equated, and solved for the reference array sample, n. (For the derivation, the phase, φ, may be set to 0, and the ramp rate, RR, and initial speed, ω(0), may be converted to Hz/s and Hz, respectively.) Thus:
[
Ref
(
n
)
=
δ
+
K
2
sin
(
2
π
*
n
L
)
]
=
[
T
(
kT
s
)
=
δ
+
K
2
sin
(
2
π
*
(
1
2
(
kT
s
)
2
*
RR
+
ω
(
0
)
*
kT
s
)
)
]
,
[
δ
+
K
2
sin
(
2
π
*
n
L
)
]
=
[
δ
+
K
2
sin
(
2
π
*
(
1
2
(
kT
s
)
2
*
RR
+
ω
(
0
)
*
kT
s
)
)
]
,
(
n
L
)
=
(
1
2
(
kT
s
)
2
*
RR
+
ω
(
0
)
*
kT
s
)
,
and
n
=
(
1
2
(
kT
s
)
2
*
RR
+
ω
(
0
)
*
kT
s
)
*
L
.
Finally, by implementing the above equation for n and select sampling data from the reference array, we may observe how the torque and reference signals line up. FIG. 6A illustrates the sampled torque signal 92 and the scaled, biased, and shifted reference signal 90 shown in FIG. 5C . FIG. 6B illustrates the sampled torque signal 96 and the scaled, biased, shifted, and frequency-adjusted reference signal 94 with a 100 point reference sampling array. FIG. 6C illustrates the same signal correlation as illustrated in FIG. 6B , but with a 200 point reference sampling array. The effect of utilizing more samples in the reference array may be observed from FIGS. 6B and 6C .
The above equation for n may enable a comparison of the torque signal to the reference signal for any combination of starting speeds and ramp rates. For example, if the ramp rate were 0, and the starting speed were 60 RPM (1 Hz):
n =(½( kT s ) 2 *RR+ω(0)* kT s )* L,
n =(1* kT s )* L
If the reference array length were 400, and the sampling period, T s were 0.01, then:
n
=
k
(
1
100
)
*
400
,
n
=
4
k
An actual comparison may be accomplished by iterating through the entire torque array buffer, and comparing each sample to the appropriate sample from the reference array using the equation:
n =(½( kT s ) 2 *RR+ω(0)* kT s )* L.
determine the reference sample size. For example, with a torque sampling period=0.1 second, and a length of the reference array=20, then n=2 k. This is illustrated in FIGS. 7A and 7B , wherein values of k and n, respectively, may be correlated. FIG. 7A illustrates that every data point 104 on the torque array 102 may be utilized. FIG. 7B illustrates that every other element 108 from the reference array 106 may be ignored.
As a loop through the array from k=0 to k=N−1 progresses, a magnitude of the difference between the two points, i.e. torque array data point 104 and reference array element 108 , may be calculated:
2 √{square root over (( T ( k )−Ref( n )) 2 )},
where
kε{0, 1, 2, 3, . . . N−1}, n =(½)(kT s ) 2 *RR+ω(0)*kT s )*L, Metric=Σ k=0 N−1 2 √{square root over ((T(k)−Ref(n)) 2 )}, and n=(½(kT s ) 2 *RR+ω(0)*kT s )*L.
The magnitude of the difference at each point may be summed for the entire array, then divided by the length of the torque buffer array. As an example, assuming each point in the array differs by 1, and the length of the torque array is 100, then Metric=1.
FIGS. 8A, 8B, and 8C illustrate additional analyses of the drum revolutions 4 , 5 , and 6 , respectively, illustrated in FIG. 4A . The shaded area 110 , 112 , 114 in each figure may essentially represent the metric. In FIG. 8A , for example, the shaded area 110 , i.e. the degree to which the torque curve 72 deviates from the reference curve 76 , is also represented by a bar graph 116 . An empirical threshold value 122 established for a selected laundry treating appliance running a selected cycle of operation for a selected laundry load is also represented with the bar graph 116 .
As the laundry load becomes satellized, the area 110 , 112 , 114 between the curves may be reduced, and the associated metric 116 , 118 , 120 may reflect this reduction, as illustrated in FIGS. 8A, 8B, and 8C . When the metric 120 , i.e. the difference between the torque curve and the reference curve, decreases to a value less than the empirical threshold value 122 , as illustrated in FIG. 8C , the laundry load may be said to be satellized. For example, in FIG. 8C , after completing revolution 6 , the metric 120 is less than the threshold value 122 , and the laundry load is therefore satellized. FIG. 8C indicates a satellization speed of approximately 60 RPM.
Selected equal-length intervals, or “windows,” of time may be established, and a torque signal may be generated for each selected interval. Data associated with each interval may be collected and evaluated. The intervals may advance forward in time as acceleration proceeds and satellization develops. The metric, or difference between the torque signal and the reference torque signal, may be determined as a difference in the amplitudes of the torque and reference torque signals. Alternatively, the difference between the signals may be the difference between a running average of the amplitudes of the torque signal and the reference signal. The running average may be a moving running average, which may be determined from a window of data points of fixed length advancing in time.
The embodiment of the invention described herein provides a method for readily determining a satellization speed for a selected laundry treating appliance running a selected cycle of operation for a selected laundry load. Thus, the satellization speed can be efficiently reached for effective liquid extraction while minimizing vibration and energy usage.
While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation. Reasonable variation and modification are possible within the scope of the forgoing disclosure and drawings without departing from the spirit of the invention which is defined in the appended claims. | A laundry treating appliance may include a rotatable treating chamber for receiving a laundry load for treatment, and a motor for rotating the treating chamber, and may be operated such that during the acceleration of the laundry load toward a satellizing speed, the satellizing of the laundry load may be detected, whereby subsequent operation of the laundry treating appliance may be controlled based on the detection. | 3 |
BACKGROUND OF THE INVENTION
2. Field of the Invention
This invention relates to bearing shaft seals and more particularly to such a seal including an elastomeric seal body having a lubricant sealing portion and an improved dust sealing portion spaced axially from the lubricant sealing portion.
2. Description of the Prior Art
It is well known to provide lubricant seals between a shaft and a cylindrical housing within which the shaft is supported for rotation relative to the housing, with the seal consisting of a rigid support ring adapted to fit in fluid-tight relation within a cylindrical bore in the housing. The ring supports a resilient rubber-like sealing element in fluid-tight contact with the outer surface of the relatively rotating shaft or a wear ring supported thereon. Examples of such seals are shown in U.S. Pat. Nos. 4,747,603 and 4,278,261. When seals of this type are operated in an environment where foreign matter such as dust, mud or water may contact the outer surface of the resilient sealing element, it is common practice to provide a secondary seal usually referred to as a dust lip or auxiliary lip, in an attempt to prevent the ingress of such foreign material (dust) into the sealed area between the housing and shaft. Seal assemblies including dust seals of this general type are shown, for example, in U.S. Pat. Nos. 4,243,232; 4,278,261; 4,336,945; and 4,721,312.
While the prior art bearing shaft seals incorporating dust lips have generally been satisfactory for most uses, they have not been entirely satisfactory for use in environments containing heavy concentrations of abrasive and corrosive dust, particularly where inspection of the seal and related equipment cannot readily be made during operation. For example, the wheels on railroad cars are supported on the car axles or shafts for rotation by low friction roller bearings, with seals provided at each end of each wheel bearing to prevent the escape of the grease or oil used to lubricate the bearing and to prevent ingress of contaminants. Such seals are subject to constant and severe vibration while the car is being transported and continuously operate in a hostile environment where dust and corrosive materials from the product hauled, as well as dust, mud and water from the roadbed, present a serious problem because of the tendency of abrasive and corrosive materials to find their way past the seal and contaminate the lubricant. Such contaminant materials tend to be very abrasive to the shaft and/or wear ring, causing premature wear and failure, with the consequent danger of accelerated dust penetration or lubrication loss and damage to the sealed bearing structure.
As pointed out in the above-mentioned U.S. Pat. No. 4,336,945, seals of this type generally employ a so-called hydrodynamic or pumping surface contour in the area of the primary lubricant sealing lip, which pumping surface tends to pump or impel escaping oil back into the sealed area. Any dust particles or the like which penetrate past the dust seal portion may actually be entrained in escaping oil adjacent the primary lubrication sealing area and be pumped back into the sealed bearing cavity. The abrasive action of even small amounts of such dust can increase the bearing friction, thereby causing overheating of the lubricant and ultimate failure of the bearing.
Attempts to solve the problem of dust penetration include providing dual dust lips spaced axially from one another, with the lips dimensioned to contact the shaft and to be deflected outwardly away from the lubricant seal portion when the seal is installed. It should be apparent, however, that where a seal is employed at each end of a bearing which is mounted from one end of an axle or shaft, the desired outwardly deflected arrangement of the dual dust seal lips disclosed in this patent cannot always be assured. Further, a double sealing lip continuously contacting the shaft increases the friction load which not only requires additional power or energy, but also results in additional heat which can result in an overheating of the seal and premature or accelerated degeneration of the elastomer. Heat from seals are a known contributing factor or cause of many hot boxes on rail cars. Even where the temperature of the bearing is not elevated to a dangerous condition, the temperature may rise sufficiently to cause a premature warning to be given from a hot box detector causing a railcar to be unnecessarily pulled from service.
In the normal operation of low friction roller bearings such as used to mount a wheel on a rail car axle, some small amount of lubricant will inevitably leak past the primary lubricant seal lip. Some leakage is desirable to wet the primary lip, and such leakage generally is minimized and controlled by a combination of features including the use of compression members such as an endless coil garter spring ring employed to continuously resiliently urge the lubricant sealing lip into contact with the rotating shaft and the use of the above-mentioned hydrodynamic surface contour on the resilient primary lubricant sealing lip.
Any lubricant weepage past the dust lip will quickly become contaminated with dust particles and will tend to build up on the shaft outwardly adjacent the dust lip. Entrainment of substantial dust particles causes the contaminated lubricant to become abrasive and wear the shaft or wear ring and, to a much lesser extent, the resilient sealing element with which it is in rubbing contact. Such seal and/or shaft ring wear reduces the efficiency of the dust shield and increases the likelihood of ingress of contamination through the primary lubricant seal into the sealed bearing area. Also, ingress of dust particles will ultimately increase wear on the primary lubricant sealing surface and clog the hydrodynamic feature referred to above.
It is, therefore, a primary object of the present invention to provide an improved bearing shaft seal assembly.
Another object is to provide a shaft seal element which includes improved dust sealing features.
Another object is to provide such a sealing element including a primary lubricant sealing area and axially spaced dust sealing area, with the dust sealing area including both a shaft contacting and a non-contacting lip to improve the dust sealing qualities of the assembly.
Another object of the invention is to provide an improved wheel bearing seal assembly for heavy duty vehicles having improved sealing qualities and longer service life.
SUMMARY OF THE INVENTION
In the attainment of the foregoing and other objects, an important feature of the invention resides in providing a low friction seal employing a double dust lip seal which is highly effective in preventing the ingress of dust particles into the sealed area. This is accomplished by providing a primary and a secondary dust sealing lip, i.e, a double dust lip, with the primary dust sealing lip and secondary dust sealing lip being located axially outward from the primary or main lubricant sealing lip and with the primary dust sealing lip dimensioned to be in continuous rubbing or sealing contact with the outer surface of the relatively rotating shaft element and the inner or secondary dust sealing lip located axially inward of the primary dust sealing lip and dimensioned to be in closely spaced relation to but not in rubbing contact with the shaft element.
The primary and secondary dust sealing lips are dimensioned such that the outer primary dust lip is relatively flexible while the inner or secondary dust lip provides greater rigidity or stability to thereby maintain the close tolerance spacing with the shaft. The secondary dust sealing lip operating out of contact with the shaft element has been found to substantially reduce the ingress of dust particles into the area outward of and adjacent to the primary lubricant sealing surface of the seal body. As a consequence, the ingress or pumping of contaminated oil into the sealed area of the bearing by the hydrodynamic surface on the seal is substantially reduced. It is believed that dust particles which find their way past the primary dust seal lip tend to become entrained in lubricant used to pack or pre-lube the seal or which has weeped from the sealed area and which has found its way to the area between the primary and secondary dust sealing lips. Thus, the more heavily contaminated lubricants in the cavity area are concentrated between the primary and secondary dust sealing lips. Further, the non-contacting secondary dust sealing lip has less tendency to wear and therefore maintains its enhanced dust sealing effect over a greater period of time.
BRIEF DESCRIPTION OF THE DRAWING
Other features and advantages of the invention will be apparent from the detailed description contained hereinbelow, taken in conjunction with the drawings, in which:
FIG. 1 is an enlarged fragmentary sectional view of a portion of a rail car wheel bearing and shaft embodying the improved seal of the present invention; and
FIG. 2 is a further enlarged view of a portion of the seal structure shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings in detail, an improved seal assembly in accordance with the present invention is designated generally in FIG. 1 by the reference numeral 10 and it is shown installed for use in connection with a low friction rail car wheel bearing assembly indicated generally by the reference numeral 12. The bearing assembly includes an outer housing or cup member 14 having a cylindrical recess 16 formed in its open end for receiving the seal assembly 10, and races for the bearing elements 18 which, in turn, rotate on the bearing surface of inner race ring members 20.
The seal assembly 10 comprises a rigid support ring 22 having mounted on its inner periphery a resilient sealing element indicated generally at 24. Support ring 22 includes a large diameter open ended section 26 adapted to fit in sealing relation within the cylindrical bore 16 to rigidly but releasably retain the seal on the bearing An enlarged retaining lip 28 formed on the end of cylindrical portion 26 is adapted to snap into an undercut groove 30 in the cylindrical bore 16 to retain the seal assembly on the bearing
A smaller diameter cylindrical body portion 32 of the support ring 22 extends outwardly from the bearing 12 and is joined to portion 26 by a radial segment 34. Ring 22 terminates at its end spaced from the bearing assembly 12 in an inwardly directed flange portion 36 having an inturned lip 38 for supporting the resilient seal element 24. Seal element 24 is molded on and is permanently bonded to the rigid metallic ring 22 in a manner well known in the art.
In the embodiment illustrated in the drawings, the bearing and seal assembly is supported on the cylindrical shaft or axle 40 of the rail car, and a wear ring or spacer element 42 engaging the end of the inner race element 20 axially fixes the bearing and seal on the shaft 40. Wear ring 42 preferably is formed from a harder, more wear resistant material than shaft 40, and may be replaced when worn or damaged, as necessary. A retaining cap 44 is rigidly mounted on the end of the shaft by bolt means, not shown, with the cap 44 engaging the end of the wear ring 42 to firmly clamp the wear ring and the bearing inner race on the shaft. Thus, the wear ring 42 becomes, in effect, an integral part of the shaft with inner surface of the wear ring and shaft being in fluid-tight sealing relation. As seen in FIG. 1, the sealing element 24 contacts the outer cylindrical surface 58 of the wear ring 42 to provide the desired seal to maintain the lubricant within the bearing and the sealed spaced indicated generally at 46. It should be apparent, however, that the wear ring may be omitted and the seal formed directly between the sealing element 24 and the outer surface of the shaft 40.
The seal element 24 is preferably integrally molded from a single mass of homogeneous rubber-like material preferably having a durometer hardness within the range of about 73 to 80 and for most applications should not have a hardness exceeding a 90 durometer reading. The seal body 24 is a continuous annular ring having an inner primary lubricant sealing area at its free end, i.e., the end spaced from the support lip 38. As shown in FIG. 2, the primary lubrication sealing area is defined by a lubricant sealing lip 50. A contoured hydrodynamic surface is formed on the outwardly directed surface of the lip 50 with this hydrodynamic or pumping surface being indicated by the surface contours 52. As indicated previously, such hydrodynamic pumping surfaces are known in the art and as such forms no part of the present invention. Preferably, a resilient compression element such as the endless coil spring or garter spring 54 is supported on an outwardly directed groove radially outward from the lip 50 to maintain a continuous, controlled sealing pressure between the sealing lip 50 and the outer sealing surface 58 of the wear ring 42.
At its opposite or outer end, the elastomeric body is provided with a dust seal in the form of a double dust lip including a primary outwardly directed dust lip 60 and an axially inwardly spaced, outwardly directed secondary dust lip 62 at locations generally radially inward from the end flange portion 36 of the metallic support ring. The seal body 24 has a concave inner surface 64 between sealing lips lips 60 and 62 which, together with the outer surface 58 of the wear ring 42, defines an annular cavity or pre-lube chamber 66 when the seal is installed. A second annular chamber or cavity 68 is provided between the adjacent surfaces of dust seal lips 60 and 62 and the wear ring surface 58. In practice, the chambers 66 and 68 will be filled or packed with a lubricant prior to installing the seal on the shaft or wear ring, whereby the seal is prelubricated. The lubricant used to pack the seal may be different than but must be compatible with the lubricant used in the sealed bearing.
The axial spacing between the primary lubrication sealing lip 50 and the secondary dust seal lip 72 is substantially greater than the distance between the first and second dust seal lips 70 and 72, respectively, and similarly the size of the cavity 66 is substantially larger than the volume of cavity 68. The ratio of the distance between lip 50 and lip 62 to the distance between lips 60 and 62 should be at least 4 to 1 and preferably at least 6 to 1.
As indicated by the broken line in FIG. 2, the diameter of the outer surface 58 of wear ring 42 will, when the seal is installed, deflect or deform the inner sealing edge 70 of lip 60 outward to maintain continuous rubbing contact; however, the corresponding inner edge 72 of the secondary dust seal lip 62 will be spaced from the surface 58 In practice, it is desired that the difference between the diameter of the secondary dust seal lip and the diameter of the shaft member be maintained as low as practical to produce an effective seal therebetween without resulting in actual rubbing contact. It has been found that this difference should be within the range of about 0.001 to 0.008 inches, and preferably about 0.002 to 005 inches. In contrast, the primary dust seal should be deflected outward by the shaft member to increase its diameter by about 0.003 to 0.018 inches, and preferably about 0.008 to 0.013 inches.
Tests have been conducted to compare the efficiency of the seal according to the present invention with a similar seal design but without the secondary dust seal lip. These tests have shown that contamination of the lubricant in the sealed area, i.e., inward of the primary lubricant seal, may be reduced by as much as 60% by use of the secondary, non-contacting dust seal lip. At the same time, the non-contact sealing feature of the secondary dust seal lip does not increase the torque load of the seal.
It is not known precisely how the non-contacting secondary dust seal lip functions to reduce the contamination of the bearing lubricant. It is believed however, that dust particles which find their way past the primary dust seal lip into the annular chamber 68 initially become entrained in the lubricant which acts somewhat like a stuffing box to isolate and retain the contaminated lubricant primarily in chamber 68 so that less contamination or dust reaches the area of the primary lubricant seal where it can be pumped back into the bearing by the hydrodynamic seal surface described hereinabove. Regardless of the precise manner in which the seal functions, the unique design is extremely effective in preventing the ingress of dust into the sealed area of the bearing, and this is accomplished without increased friction.
It is known that friction from commercially available lubricant seals employed on rail cars provide substantial rolling resistance. This is particularly true when initially starting a car from the rest position where up to one horsepower may be required to overcome the initial friction of each of the 16 seals employed to seal the 8 wheel bearings of a rail car. Thus, at least in theory, the train locomotive would have to apply 1600 horsepower just to overcome the rolling resistance of the wheel bearing seals to start a 100 car train. Once the train is in motion, a lesser but significant amount of power is still required to continuously overcome the bearing seal friction. Thus, elimination of a continuous rubbing seal surface in accordance with the present invention may result in substantial energy savings over seals employing two dust seal lips in continuous rubbing contact with the shaft.
While a preferred embodiment of the invention has been disclosed and described, it should be understood that the invention is not so limited but that it is intended to include all embodiments which would be apparent to one skilled in the art and which come within the spirit and scope of the invention. | A seal assembly for sealing an annular space between a housing having a cylindrical bore therein and a shaft member extending into and mounted for coaxial rotation relative to the bore, includes a resilient sealing body having an annular lubrication sealing lip and a dust seal including first inwardly directed resilient dust sealing lip having an inside diameter less than the diameter of the shaft member for contacting the shaft member and forming a primary dust seal therewith and a second inwardly extending annular dust seal lip between the first dust seal lip and the second dust seal lip having an inside diameter slightly greater than the diameter of said shaft member to form a non-contacting type seal with the other surface of the shaft member. | 5 |
BACKGROUND
FIELD OF THE INVENTION
[0001] The present invention relates generally to warm air furnaces, and more particularly, to fault detection in a warm air furnace.
BACKGROUND OF THE INVENTION
[0002] Many houses and other buildings use warm air furnaces to provide heat. Generally, these furnaces operate by heating air received through cold air or return ducts and distributing the heated air throughout the building using warm air or supply ducts. A circulation fan, operated by an alternating current (AC) permanent-split-capacitor (PSC) motor, directs the cold air into a heat exchanger, which may be composed of metal. The heat exchanger metal is heated using a burner that burns fossil fuels. The burner is ignited with an ignition device, such as an AC hot surface ignition element. The air is heated as it passes by the hot metal surfaces of the heat exchanger. After the air is heated in the heat exchanger, the fan moves the heated air through the warm air ducts. A combustion air blower, or inducer, is used to remove exhaust gases from the building. The inducer is typically operated using an AC shaded-pole motor.
[0003] Because furnaces play a critical role in the comfort and safety of occupants of the building, it is important that the warm air furnace remains functional and that any problems with furnace operation be quickly diagnosed and corrected. Such diagnosis and repair is often difficult due to the complexity of modern heating, ventilation, and/or cooling systems. Therefore, it is desirable to detect faults in the warm air furnace prior to failure.
[0004] Preventive detection and repair may prevent the occupants of the building from either remaining in an uncomfortably cold building or having to leave the building while waiting for a repair technician to fix the warm air furnace. Therefore, a need exists to detect faults in a warm air furnace while the furnace is operating. Some faults occur even prior to installation, thus it is important for the operation of a furnace that its initial installation in the home or building be done correctly and with an eye toward discovering faults due to installation or shipping. Therefore, a need exists for a system of correctly installing furnaces to correct installation and pre-installation faults.
[0005] The heating system in a building comprises the furnace, duct work, and the building itself. Thus, a particular furnace model may have different optimal operating conditions depending upon its building of residence. In addition, the individual operating conditions of the furnace-home combination may alter the expected life of replaceable components of the furnace. Therefore, a need exists for a system of discovering baseline optimal values for the furnace-home combination and detecting changes in those values.
SUMMARY
[0006] The present invention provides an apparatus for warm air furnace diagnostic enhancements and a method for using those enhancements for baselining and more effective troubleshooting. Generally, various embodiments may meet a number of objectives, including: ensuring a more robust furnace installation at a customer premises; dynamically identifying elements of the furnace that may be subject to future fault; and identifying and/or diagnosing current faults. Of course, some embodiments may meet other objectives or have other uses.
[0007] In an exemplary embodiment, a warm air furnace (“furnace”) is equipped with a Flash based microcontroller or EEPROM memory with a microcontroller to retain data in a non-volatile state. Prior to shipment from a manufacturing facility, factory test values for the furnace are measured to create a factory baseline. The measurement may involve passing the furnace through a predetermined furnace test cycle, and obtaining measures during the test cycle, for instance. As examples of potential measurements taken, key baseline furnace performance indicia to retain includes but is not limited to flame current, hot surface ignition (HSI) current, inducer current, fan current, pressure switch open and close times, and heat exchanger rates of temperature rise. These data are stored in the memory of the furnace and are accessible by a technician at installation.
[0008] During installation, measurements may be taken of the performance indicia and compared to the factory baseline. Variations from the factory baseline may indicate improper installation or damage during shipment. Alternatively, the variations may indicate that a maintenance schedule of the installed furnace should be revised or reconsidered. Thus, according to an embodiment, the furnace may determine that a variation is outside of a predetermined range of acceptable variations and, as a result, modify the maintenance schedule to recommend more immediate maintenance. An indication may be provided to a technician or furnace user of the modified maintenance schedule.
[0009] Even with proper installation, the installation baseline measures may differ from the factory baseline measures—for example, air flow rates may depend upon duct-work configuration and building size, likewise, customized furnace options may also cause installation baseline measures to differ from their factory based counterparts. In a further embodiment, an installation baseline is created during installation by measuring the baseline furnace performance indicia and storing those indicia in the memory of the furnace. The installation baseline is useful for predicting wear-out of key system components and for helping in diagnosis of fault conditions. According to the embodiment, the baseline installation indicia are then compared with later obtained indicia and with the run-time counter. The maintenance schedule of the furnace may then be modified based on the comparison.
[0010] In yet another embodiment, the apparatus compares the stored factory baseline and installation baseline and further compares those figures to later obtained measures to determine the performance of the furnace. In another embodiment, periodic measurements are taken of the performance indicia and of run-time counters to help predict system degradation. Such time-series information is also useful for determining whether a particular problem is due to acute failure or to a gradual decline in performance.
[0011] According to the preferred embodiment, the warm are furnace includes a data storage and a processor. The data storage may be used to store furnace performance data as well as instructions that are executable by a processor. Sensing circuitry is also provided for obtaining furnace performance data during operation of the warm air furnace. These various elements of the furnace may be communicatively linked through a data bus. The instructions stored in data storage may be machine language programs for obtaining readings from the sensing circuitry, storing the readings in data storage, comparing the various readings, and updating a maintenance schedule based upon the comparisons, for instance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Presently preferred embodiments are described below in conjunction with the appended drawing figures, wherein like reference numerals refer to like elements in the various figures, and wherein:
[0013] FIG. 1 is a block diagram of a warm air furnace with diagnostics.
[0014] FIG. 2 is a block diagram of a control system for a warm air furnace with diagnostics.
[0015] FIG. 3 is a flow chart of a method of operation of the warm air furnace.
DETAILED DESCRIPTION
[0000] Exemplary Warm Air Furnace and Control
[0016] FIG. 1 shows a simplified block diagram of a warm air furnace 100 . The warm air furnace 100 includes a controller 102 , a gas valve 104 , a burner 106 , an ignition element 108 , a circulator fan 112 , a heat exchanger 114 , and a combustion air blower 116 , which is also referred to as an inducer. The warm air furnace 100 may include additional components not shown in FIG. 1 , such as sensors for detecting temperature and pressure, and filters for trapping airborne dirt. Furthermore, warm air furnaces have various efficiency ratings. Additional components may be necessary to achieve different levels of efficiency.
[0017] The warm air furnace 100 depicted in FIG. 1 is fueled by natural gas. However, the warm air furnace 100 may be fueled by other fossil fuels, such as oil and propane. Different fuel sources may require different components in the warm air furnace 100 . For example, a warm air furnace fueled by oil may include an oil pump.
[0018] The warm air furnace 100 may be connected to a thermostat, an exhaust vent, warm air or supply ducts, cold air or return ducts, and a gas supply. The warm air furnace 100 may also be connected to an alternating current (AC) power supply. The warm air furnace may have at least one AC load. For example, the ignition element 108 may be an AC hot surface ignition element, the fan 112 may include an AC motor, such as an AC permanent-split-capacitor (PSC) motor, and the inducer 116 may include an AC motor, such as an AC shaded-pole motor.
[0019] Generally, the warm air furnace 100 operates as follows. The thermostat sends a “heat request” signal to the controller 102 when the thermostat is adjusted upwards. The controller 102 may perform a safety check, which may include checking a pressure switch located within the warm air furnace 100 . (The pressure switch is not shown in FIG. 1 .) Once the safety check is completed, the controller 102 may activate the inducer 116 by turning on an inducer motor, such as an AC shaded-pole motor. After turning on the AC shaded-pole motor, the controller 102 may verify that the pressure switch in the warm air furnace 100 closes. If the pressure switch closes properly, the controller 102 may then activate the ignition element 108 .
[0020] The controller 102 may then open the gas valve 104 , which may activate the burner 106 . The burner 106 may mix the natural gas with air and burn the gas mixture. The ignition element 108 may ignite the gas mixture causing a flame 110 to develop. Once the flame 110 has been produced by the ignition element 108 and sensed by a flame sense rod (not shown in FIG. 1 ), the ignition element 108 may be deactivated. The flame 110 may warm metal in the heat exchanger 114 .
[0021] After the heat exchanger 114 warms for a predetermined time, typically 15 to 30 seconds, the fan 112 may be activated. The fan 112 may direct cold air received from the cold air ducts into the heat exchanger 114 . The heat exchanger 114 may separate the warm air from exhaust gases. The fan 112 may cause the warm air to exit the heat exchanger 114 through the warm air ducts, while the inducer 116 may cause the exhaust gases to exit through an exhaust vent connected to the outdoors.
[0022] The controller 102 may close the gas valve 104 when the thermostat setting has been reached. The inducer 116 may be deactivated after a predetermined time period, such as 30 seconds, to ensure that the exhaust gasses have been removed from the heat exchanger 114 . The fan 112 may be deactivated after a predetermined time period, such as 120 seconds, to ensure the heat from the heat exchanger 114 is delivered to the warm air ducts. When the ignition element 108 , the fan 112 , and the inducer 116 are turned off, the warm air furnace 100 may be in an Idle mode.
[0023] During both the Idle mode and heating mode, it would be beneficial to monitor the warm air furnace 100 and potentially detect a fault condition prior to damaging the warm air furnace 100 . In a preferred embodiment, a current sensing circuit may be used to measure current levels at various points during a warm air furnace 100 operating sequence. In an embodiment, the warm air furnace may be adjoined with a cooling system such as an air conditioner or a humidifier for example.
[0024] FIG. 2 is a block diagram of a monitoring and control device 200 according to an exemplary embodiment. Other monitoring and control devices may be used. The monitoring and control device 200 may be located within the controller 102 , although elements of the monitoring and control device 200 may be distributed throughout the furnace 100 . Alternatively, the monitoring and control device 200 may be located separately or within another component of the warm air furnace 100 . According to the embodiment, non-volatile data storage is included in the monitoring and control device 200 for retaining key performance measures. By comparing key performance data recorded during production testing with data gathered at initial installation, installers can be warned about certain installation problems that can lead to premature failure. By monitoring the degradation of key performance measures and recording run time, warnings can be issued on wear-out of key WAF systems. By retaining all fault conditions over time, intermittent problems can be more readily diagnosed.
[0025] As shown in FIG. 2 , the monitoring and control device includes a processor 202 , a set of sensing devices 210 , 212 , 214 , 216 , 220 , 222 , 224 , 226 , 228 , 230 communicatively coupled with the processor 202 , an analog-to-digital converter 208 to convert signals from at one of the sensing devices from an analog signal to a digital signal, data storage 204 , an input/output (I/O) port 206 , and furnace control switches 234 . The various elements of the monitoring and control device 200 are inter-coupled via a data bus 232 . In the exemplary embodiment, the data storage 204 stores program code such as machine readable instructions for execution by the processor 202 , stored parameters that provide guidance and user preferences for execution of the program code, and measured data such as indicia received from the sensing devices or calculated by the processor 202 . The processor 202 may be one or more processing units, such as a general-purpose processor and/or a digital signal processor.
[0026] The plurality of sensing devices are now described. A flame current sensor 210 provides an indication of the presence of flame in the furnace. Several types of flame current sensors may be used including A/C flame ionization sensors and photocell flame sensors. A low flame current at initial installation may indicate poor earth ground connection, flame rod movement due to shipping, low AC voltage, or incorrect AC voltage polarity. High flame current at initial installation may indicate over-fire, high AC line, or flame rod movement during shipping. At later points, variance in flame current may be indicative of other problems such as low flame level, damaged flame current sensor 210 , and/or a need for furnace maintenance.
[0027] An inducer current sensor 212 provides an indication of whether the inducer 116 is operating properly. According to an exemplary embodiment, the inducer current sensor 212 measures the current used by the inducer 116 . Likewise, a fan current sensor 214 provides an indication of whether the fan 112 is operating properly. According to the embodiment, the fan current sensor 213 measures the current used by the inducer 116 . In a preferred embodiment, a single sensor may comprise the fan current sensor 214 , inducer current sensor 212 , etc. This may allow a system to be configured with just one current sensor yet obtain a variety of data.
[0028] In the presently described embodiment, the flame current sensor 210 , inducer current sensor 212 , and fan current sensor 214 each measure current level as an analog signal. The A/D converter 208 is used to convert the analog signals from the three current sensors 210 , 212 , 214 to digital signals for the processor 202 and data storage 204 . In furnaces using a pressure switch, a pressure switch sensor 216 indicates whether the pressure switch is open or closed. The pressure switch is used as a safety feature to automatically sense change in pressure and open or close an electrical switching element when a predetermined pressure point is reached. The pressure switch sensor 216 may further be used to indicate pressure switch open time and pressure switch close time. A heat exchanger temperature sensor 220 measures a temperature in the heat exchanger 114 . The sensor 220 may further be used to obtain a rate of temperature change in the heat exchanger. An increased temperature rise rate can, for instance, indicate a dirty air filter, excessive duct restriction, fan motor failure, or over fire condition.
[0029] Some elements of a furnace tend to wear out according to the run-time of specific portions of the furnace cycle. For example, elements associated with heating will need maintenance much less often if the furnace system is only used as a fan and/or air conditioner. Thus, several devices are provided for determining the run-time of portions of the furnace cycle. For instance, a heating switch 222 indicates whether the furnace is operating in a heating mode, a cooling switch 224 indicates whether the furnace is operating in a cooling (A/C) mode, a fan switch 226 indicates whether the furnace is operating in a fan-only mode, an igniter switch 228 indicates whether the furnace is operating with the igniter on, and a pressure switch indicates whether the motor and/or ductwork is operating properly. A counter 230 provides timing information for each portion of the cycle. Thus, according to an embodiment, the measurement and control device 200 may determine, using the heating switch 222 and counter 230 , that the furnace has been operating in a heating mode for a specified number of hours, such as 3,000 hours, for instance.
[0030] Alternatively/additionally, the counter 230 , may be configured to keep track of the number of run-cycles that have taken place for each portion of the cycle. Thus, according to an embodiment, the measurement and control device 200 may determine, using heating switch 222 and counter 230 , that the furnace has operated in a heating mode for a specified number of cycles, such as 30,000 cycles. As with run-time, the number of cycles can be coupled with other measurements to determine or indicate a rate of degradation of elements of the furnace system, and thus to predict future failure or indicate present failure.
[0031] The I/O port 206 may allow the monitoring and control device 200 to communicate with a user and/or technician by, for instance, warning the user that the furnace is not functioning correctly or by indicating that the maintenance schedule has been updated. As such, the port 206 may include a speaker, display (LCD) or lights to provide a audible or visual output to the user. Further, the I/O port 206 may provide connectivity for a technician to obtain stored data and alter stored parameters. In an alternative embodiment, data storage 204 includes a removable memory device such as a flash memory microcontroller or EEPROM memory with a microcontroller. In that case, the technician may transfer data to and from the monitoring and control device 200 using the removable memory device. Further, the system may be configured so that a technician may obtain data via a hand-held tool, such as a portable data device or personal data assistant (PDA). It is contemplated that the hand-held tool may be connected via a Honeywell EnviroCOM thermostat or via a wireless interface, for instance.
[0032] The furnace control switches 234 allow the processor 202 to control activity of the furnace. For example, in an embodiment, the processor 202 executes a standard test cycle through the furnace control switches 234 . In the test cycle, the furnace may be placed in various modes such as heating and cooling modes. During the test cycle, performance indicia are measured through the various sensing devices and may be further calculated by the processors 202 and stored in data storage 204 .
[0000] Exemplary Operation
[0033] FIG. 3 provides a flow chart illustrating a method of operation that may be used to modify a maintenance schedule of the warm air furnace 100 . The method measures current consumption and other indicia at several points in the warm air furnace 100 operating sequence. The measured indicia are then compared with baseline measures obtained before shipment of the furnace from a factory setting. Depending upon the results of the comparison, a maintenance schedule for the furnace 100 may be modified and/or immediate maintenance recommended.
[0034] Initial installation data can be used to predict wear-out of key system components and to help in diagnosis of fault conditions. For example, increased temperature rate of rise can indicate dirty air filter, excessive duct restriction, over fire condition, or fan motor failure. Decreased HSI current can indicate a failing igniter element. Increased motor currents can indicate bearing wear, winding fault or locked rotor conditions. Pressure switch close or open time increase can indicate increased vent restriction, or inducer motor performance change.
[0035] Before installation, a baseline performance metric for the furnace 100 is obtained 302 . This metric may be obtained in the factory where the furnace is manufactured, for instance. The baseline performance metric is preferably a set of indicia measured by the measurement and control device 200 . These indicia may include, for instance, factory test values for flame current, HSI current, inducer current, fan current, pressure switch open and close times, and heat exchanger rate of temperature rise. The furnace is then installed at a customer premises at 304 . During installation, the measurement and control device 200 is used to determine an installed performance metric at 306 . As with the baseline performance metric, the installed performance metric may include a set of indicia measured by the measurement and control device 200 . In order to obtain the indicia, the measurement and control device 200 may initiate a furnace test cycle. At predetermined portions during the test cycle, the measurement and control device 200 may obtain and record the indicia.
[0036] The test cycle may include passing the current through an idle mode, safety check mode, inducer start mode, inducer run mode, ignition mode, and burn mode for instance. When the warm air furnace 100 is in the idle mode, the ignition element 108 , the fan 112 , and the inducer 116 may be deactivated. During the idle mode 302 , a low current value may be supplied to the warm air furnace 100 due to the lack of current consumption by the ignition element 108 , the fan 112 , and the inducer 116 . The measurement and control device 200 may take an “Idle” current reading during the Idle mode. Alternatively, the current sensing circuit 200 may take periodic Idle current readings during the Idle mode. If the Idle current reading is above a baseline amount, there may be a problem with the warm air furnace 100 . A fault may be caused by shorted or damaged low voltage transformer in the AC power supply 202 . Following the idle mode, the furnace may pass through a safety check mode. In the safety check mode, the pressure switch may be checked to ensure that it is operating properly. If the pressure switch open and close times vary from a baseline measure, then there may be a need for immediate maintenance.
[0037] Next, the furnace may be placed in the inducer start mode, and an inducer current is read during a first period after the inducer motor begins operation. If the inducer start current reading at installation is above a baseline reading, there may be a problem with the warm air furnace 100 . For example, either shorted wiring or motor windings in the inducer 116 may have caused the fault. After a wait period, an inducer run mode may be entered and another inducer current may be read. This second inducer period may be several seconds after the inducer start mode. If the installation inducer run current reading is above or below the corresponding baseline value, there may be a problem with the warm air furnace 100 . For instance, if the inducer run current reading is well above the baseline reading, motor windings may be beginning to short, motor bearings may be beginning to seize, or a rotor in the AC shaded-pole motor may be locked due to an obstruction. If the inducer run current is below the baseline amount, an excessive vent restriction, deteriorating wiring connections, failing or failed motor windings, or a damaged controller 102 may have caused the fault.
[0038] The furnace may then be placed in an ignition mode by activating the ignition element 108 . At that point, an ignition current reading may be taken. If the reading is above or below the baseline amount, there may be a problem with the warm air furnace 100 . If the ignition current reading is above the baseline amount, shorted wiring or ignition element 108 may have caused the fault. If the ignition current reading is below the baseline amount, deteriorating wiring connections or ignition element 108 , an open ignition element 108 , or a damaged controller 102 may have caused the fault.
[0039] The controller 102 may then open the gas valve 104 after a warm-up period following activation of the ignition element 108 . Once ignition element 108 has ignited the flame 110 , the ignition element 108 may be deactivated. A third inducer current reading may be taken at this point. After a delay period to allow the heat exchanger 114 to begin heating, the controller 102 may activate the fan 112 , as depicted in box, and a fan start current reading may be taken soon after the fan motor begins operation. If the fan start current reading is above a baseline amount, there may be a problem with the warm air furnace 100 . For instance, either shorted wiring or motor windings in the fan 112 may have caused a fault.
[0040] After a wait period, the furnace may take a fan run current reading during a second period after the fan motor begins operation. The second period may be substantially 30 seconds after the first fan run current reading. If the second fan run current reading is above or below the corresponding baseline amount, there may be a problem with the warm air furnace 100 . If the fan run current reading is above the baseline amount, motor windings in the fan motor may be beginning to short, motor bearings in the fan motor may be beginning to seize, or a fan cage may be locked or obstructed. If the fan run current reading is below the baseline amount, a duct restriction, deteriorating wiring connections, failing or failed motor windings, or a damaged controller 102 may have caused the fault.
[0041] The controller 102 may close the gas valve 104 when the thermostat setting has been reached. The inducer 116 may be deactivated after a predetermined time period, such as 30 seconds, to ensure that the exhaust gasses have been removed from the heat exchanger 114 . The fan 112 may be deactivated after a predetermined time period, such as 120 seconds, to ensure the heat from the heat exchanger 114 is delivered to the warm air ducts. The warm air furnace 100 may return to the idle mode 302 another idle current reading may be taken.
[0042] In this embodiment, the installed performance metric comprises the set of indicia obtained during the test cycle. Once the installation performance metric is determined, the processor 202 is used to compare the installation performance metric with the baseline performance metric.
[0043] According to the exemplary embodiment, the results of the comparison may fall into three categories: limited variance; significant variance, but within threshold; and variance outside threshold. If there is only a limited variance between the metrics 310 , then there will be no modification of a furnace maintenance schedule. If there is a significant variance, but the variance remains within a threshold (such as within 50% of the baseline) 312 then the processor 202 may modify the maintenance schedule to account for the difference between the baseline metric and the installed metric. If instead, the variance is outside of the threshold, then immediate maintenance should be required. Preferably, an installation technician is notified of the need for immediate maintenance. In a further embodiment, the processor is configured it identify at least one component in the warm air furnace that may have caused the fault.
[0044] In some cases, a factory baseline metric may be unavailable. In those cases, recommended operational values for the furnace may be used in place of a measured baseline.
[0045] Although the method outlined by FIG. 3 uses a comparison between a factory baseline metric and an installed metric. In a further embodiment, a similar test cycle can be performed on a regular basis such as for each operating cycle of the warm air furnace 100 . Alternatively, the testing may be performed on a periodic basis such as daily. In that case, the new readings may be compared to the baseline metric as well as other, previously measured metrics. Further, some tests may be performed more than others based on failure rates of the warm air furnace components. It is also understood that additional current readings may be taken during the operation of the warm air furnace 100 . While the most likely causes of the faults are provided in method 300 , additional warm air furnace components may cause a fault.
[0046] Not every test described in the method 300 needs to be run during every operational cycle of the warm air furnace 100 . For example, some tests may be performed each time the warm air furnace 100 completes an operational cycle, while other tests may be performed less frequently. Additional tests may also be included in the method.
[0047] By maintaining a run-time counter, periodic maintenance intervals can be established. The home-owner can then be notified when a system component has reached a service interval and should be checked. In a further embodiment, the system may be configured to allow a home-owner to trigger a test cycle to diagnose any suspected problems.
[0048] In a further embodiment, error codes that have occurred since a reset of memory are stored in the data storage. Retaining all error code conditions seen by the WAF greatly improves troubleshooting; especially for intermittent faults. The control provides a means to read-out and clear all stored error codes and may have a plug to download data onto handheld device or use wireless communication such as Bluetooth, for instance.
[0049] It should be understood that the illustrated embodiments are exemplary only and should not be taken as limiting the scope of the present invention. For example, the invention may be used to detect faults in other ignition-controlled appliances, such as a water heater. The claims should not be read as limited to the described order or elements unless stated to that effect. Therefore, all embodiments that come within the scope and spirit of the following claims and equivalents thereto are claimed as the invention. | A warm-air furnace is adapted to provide diagnostic enhancements and more robust installation. In an embodiment, sensing equipment aboard the furnace is used to determine a first performance metric during installation of the furnace. That performance metric is then compared with a baseline metric that may have been obtained at a factory in order to obtain a performance variation value. At least partially in response to the performance variation, a notification is provided to a user. The notification may be an indication of poor installation or shipping damage, present failure and/or predicted future failure, for instance. | 5 |
BACKGROUND OF THE INVENTION
[0001] (a) Field of the Invention
[0002] The present invention relates to a poly(ethyleneterephthalate) drawn fiber, which is able to provide a poly(ethylene terephthalate) tire-cord showing superior strength and dimensional stability without a PCI process after tire vulcanization, a poly(ethylene terephthalate) tire-cord, and a manufacturing method thereof.
[0003] (b) Description of the Related Art
[0004] A tire is a complex body of fiber/steel/rubber, and generally has a structure as illustrated in FIG. 1 . Herein, a body ply is, also called carcass, a reinforcing cord layer inside the tire, and supports the entire load of vehicle, maintains the tire shape, and withstands against a shock, and is required to have high fatigue resistance against bending and stretching movement during driving. Therefore, a tire-cord for the body ply is required to have excellent dimensional stability together with superior strength for supporting a large load, and synthetic fiber cords such as polyesters or the like have been used generally.
[0005] The synthetic fiber cord has high tenacity to greatly contribute to the durability improvement of tire. However, it has a disadvantage of reducing elasticity and dimensional stability of the tire after vulcanization due to its high heat shrinkage ratio. In order to make up for this disadvantage, an additional process such PCI (Post Cure Inflation) has been applied to improve the dimensional stability of the tire after vulcanization thereof. However, such PCI process is one of the major factors causing a productivity reduction in the tire manufacturing process, and tire deformation occurs during the PCI process, causing a reduction in quality or occurrence of defects.
[0006] Recently, an ultra high-speed spinning technique was employed in the manufacturing process of tire-cord, and thus it is possible to manufacture a polyester tire-cord having high modulus low shrinkage (HMLS) properties and superior dimensional stability.
[0007] When the ultra high-speed spinning technique is employed, an undrawn fiber having high crystallinity should be used. Since this undrawn fiber has a relatively narrow region to be drawn, non-uniform drawing or breakage due to friction easily occurs when the ultra high-speed spinning technique is employed. Moreover, if the drawing ratio is lowered in order to prevent the non-uniform drawing, it is difficult to achieve sufficient mechanical properties of the drawn fiber and tire-cord, such as strength. For this reason, there is a limitation in the application of the ultra high-speed spinning technique. In particular, it is also difficult to achieve sufficient dimensional stability when the ultra high-speed spinning technique is employed.
[0008] Due to the above described technical limitations, high dimensional stability of the tire-cord has not been sufficiently achieved yet, and thus the PCI process is still required in the tire manufacturing process, which is still a major factor causing a reduction in productivity or quality of tire.
SUMMARY OF THE INVENTION
[0009] The present invention provides a poly(ethyleneterephthalate) drawn fiber, which is able to provide a poly(ethylene terephthalate) tire-cord showing superior strength and dimensional stability even though a PCI process is omitted after tire vulcanization, and a manufacturing method thereof.
[0010] Further, the present invention provides a poly(ethylene terephthalate) tire-cord, which shows superior strength and dimensional stability without a PCI process, thereby being suitably used in the cord for body ply, and a manufacturing method thereof.
[0011] The present invention provides a poly(ethyleneterephthalate) drawn fiber, of which an L/S value defined as the following Equation is 2.0 kg/% or more after heat treatment at a temperature of 180° C. under an initial load of 0.02 g/d for 2 minutes:
[0000] L/S =LASE(kg)/shrinkage rate(%) [Equation 1]
[0012] wherein LASE (kg) represents Load at Specific Elongation when elongation of the drawn fiber is 5%, after heat treatment for 2 minutes, and shrinkage rate (%) represents a dry heat shrinkage rate which is measured while the drawn fiber is maintained at the temperature of 180° C. without the initial load, after heat treatment for 2 minutes.
[0013] Further, the present invention provides a method for manufacturing the poly(ethyleneterephthalate) drawn fiber, including the steps of: melt-spinning a polymer including 90 mol % or more of poly(ethyleneterephthalate) and having a melt viscosity of 3000 to 5000 poise at 290° C. and at a shear rate of 1000 s −1 , through a spinneret having a spinneret hole area of 0.18 to 0.4 mm 2 /De at a speed of 3000 to 4000 m/min so as to produce an undrawn fiber; and drawing the undrawn fiber with a drawing ratio of 1.5 to 1.8 times.
[0014] Further, the present invention provides a poly(ethyleneterephthalate) tire-cord having a PCI index of 1.5% or less, in which the PCI index is defined as a difference between a dry heat shrinkage rate after heat treatment at 180° C. for 2 minutes under a load of 0.01 g/d and a dry heat shrinkage rate after heat treatment at 180° C. for 2 minutes under a load of 0.1 g/d.
[0015] Further, the present invention provides a method for manufacturing the poly(ethyleneterephthalate) tire-cord, including the steps of producing a poly(ethyleneterephthalate) drawn fiber by the above described method; twisting the drawn fibers; and dipping the twisted fibers in an adhesive solution, followed by heat treatment.
[0016] Hereinafter, a poly(ethyleneterephthalate) drawn fiber, a poly(ethyleneterephthalate) tire-cord, and a manufacturing method thereof will be described according to the specific embodiments of the present invention. However, since the embodiments are provided as examples of the present invention, the scope of the right of the present invention is not limited thereto and it is obvious to a person skilled in the related art that various modifications of the embodiments are possible within the scope of the right of the present invention.
[0017] In addition, the term ‘include’ or ‘comprise’ means that it includes a particular component (or particular element) without particular limitations unless otherwise mentioned in the present entire disclosure, and it cannot be interpreted as it excludes the addition of the other components.
[0018] The poly(ethyleneterephthalate) (hereinafter, referred to as ‘PET’) tire-cord may be produced by melt-spinning a polymer PET to produce an undrawn fiber, drawing the undrawn fiber to obtain a PET drawn fiber, twisting the PET drawn fibers, and dipping them into the adhesive to produce the PET tire cord in a dip cord type. Therefore, the properties of the undrawn fiber produced by the melt-spinning of the PET and the drawn fiber produced by drawing the same are directly or indirectly reflected to the properties of the PET tire cord.
[0019] The present inventors have made many studies on the drawn fiber for tire-cord, and they found that the melt-spinning conditions such as melt viscosity of the polymer at the temperature corresponding to the melt-spinning temperature and the spinneret hole area of the spinneret are optimized while an ultra high-speed spinning technique is employed, so as to manufacture a PET drawn fiber and a tire-cord having superior strength and dimensional stability without PCI process, thereby completing the present invention. More specific descriptions thereof are the same as follows.
[0020] Previously, the present inventors revealed that the ultra high-speed spinning technique is applied to the PET polymer having high viscosity to cause an oriented crystallization phenomenon of the PET polymer as described below, thereby manufacturing and providing a PET drawn fiber and a tire-cord having superior dimensional stability or the like, and they applied Korean Patent Application No. 2007-0060370, etc. In this regard, it is assumed that the PET drawn fiber and the tire-cord having superior dimensional stability can be provided through the ultra high-speed spinning technique, because oriented crystallization phenomenon of the PET polymer occurs due to high spinning draft during the melt-spinning process and thus the PET undrawn fiber and the drawn fiber having high crystallinity and low amorphous orientation factor can be obtained.
[0021] However, the results of continuous experiments of the present inventors showed that the melt-spinning conditions such as melt viscosity of the polymer at the melt-spinning temperature and the spinneret hole area of the spinneret as well as the spinning speed applied to the ultra high-speed spinning technique greatly affect the high spinning draft and occurrence of oriented crystallization phenomenon of the optimized PET polymer. More specifically, it was revealed that high spinning draft can be more effectively achieved and oriented crystallization phenomenon of the PET polymer may more preferably occur by using a PET polymer having a melt viscosity of approximately 3000 to 5000 poise at approximately 290° C. corresponding to the melt-spinning conditions and at a shear rate of approximately 1000 s −1 , and employing a spinneret having a spinneret hole area of approximately 0.18 to 0.4 mm 2 /De, while applying a high spinning speed of approximately 3000 to 4000 m/min. Therefore, a PET drawn fiber and a tire-cord having superior dimensional stability and mechanical properties such as strength or the like can be provided by controlling such conditions, and the PCI process can be omitted.
[0022] Further, as the process conditions such as the above described specific ranges of the melt viscosity and the spinneret hole area are applied, advantages of the ultra high-speed spinning technique are brought out as much as possible so as to achieve a PET drawn fiber and a tire-cord having superior dimensional stability and strength, and also to minimize a reduction in physical properties or performances during the manufacturing process, such as non-uniform cooling, a reduction in strength due to smaller diameter of monofilament or deterioration in fatigue performance of the tire-cord.
[0023] Therefore, the present inventors revealed that a PET drawn fiber and a tire-cord having superior strength and dimensional stability can be manufactured and provided through optimization of the above described melt-spinning conditions or the like, even though the PCI process is omitted after tire vulcanization, thereby completing the present invention.
[0024] According to one embodiment of the present invention, a PET drawn fiber having novel physical properties that can be manufactured and provided by application of the above described melt-spinning conditions is finally provided. The PET drawn fiber has an L/S value of approximately 2.0 kg/% or more, defined as the following Equation 1, after heat treatment at a temperature of approximately 180° C. under an initial load of approximately 0.02 g/d for 2 minutes:
[0000] L/S =LASE(kg)/shrinkage rate(%) [Equation 1]
[0025] wherein LASE (kg) represents Load at Specific Elongation when elongation of the drawn fiber is approximately 5%, after heat treatment for 2 minutes, and shrinkage rate (%) represents a dry heat shrinkage rate measured while the drawn fiber is maintained at the temperature of approximately 180° C. without the initial load, after heat treatment for 2 minutes.
[0026] The PET drawn fiber of one embodiment shows property of the US value of approximately 2.0 kg/% or more, or approximately 2.1 to 3.5 kg/% because the shrinkage rate after heat treatment is low and the load applied to the PET drawn fiber is relatively high at an elongation of approximately 5%. The PET drawn fiber has low shrinkage rate and high load for elongation under heat treatment conditions corresponding to tire vulcanization, thereby showing excellent dimensional stability. In particular, the PET drawn fiber and the tire-cord obtained therefrom are able to show excellent dimensional stability after tire vulcanization, without applying an additional process such as PCI process.
[0027] Further, the PET drawn fiber of one embodiment shows properties of a tensile strength of approximately 7.0 g/d or more, or approximately 7.5 to 9.0 g/d, or approximately 7.7 to 8.5 g/d, an intermediate elongation of approximately 4.0 to 6.5%, or approximately 4.5 to 6.0%, a breaking elongation of approximately 10.0 to 20.0%, or approximately 10.5 to 18.0%, or approximately 11.0 to 15.0% under a load of 4.5 g/d, a coefficient of variation(C.V %) of approximately 7% or less, or approximately 4.0 to 6.8%, or approximately 5.5 to 6.7%. Therefore, the PET drawn fiber shows physical properties such as excellent and uniform strength, dimensional stability or the like, and owing to these excellent physical properties of the drawn fiber, a tire-cord showing both excellent strength and dimensional stability can be manufactured.
[0028] Meanwhile, according to another embodiment of the present invention, a method for manufacturing the above described PET drawn fiber is provided. The manufacturing method of the PET drawn fiber may include the steps of melt-spinning a polymer including 90 mol % or more of PET and having a melt viscosity of approximately 3000 to 5000 poise at approximately 290° C. and at a shear rate of approximately 1000 5 −1 , through a spinneret having a spinneret hole area of approximately 0.18 to 0.4 mm 2 /De at a speed of approximately 3000 to 4000 m/min so as to produce an undrawn fiber; and drawing the undrawn fiber with a drawing ratio of approximately 1.5 to 1.8 times.
[0029] In the manufacturing method of another embodiment, the ultra high-speed spinning technique is applied at a high spinning speed of approximately 3000 to 4000 m/min, the PET polymer having a high melt viscosity under melt-spinning conditions is used, and a spinneret having a specific spinneret hole area is used to carry out the melt-spinning process so as to manufacture the PET undrawn fiber, and then the PET drawn fiber is manufactured therefrom.
[0030] As described above, as the melt-spinning process is carried out under such specific conditions, the spinning draft during the melt-spinning can be more effectively increased, and oriented crystallization phenomenon of the PET polymer is optimized to bring out advantages of the ultra high-speed spinning technique as much as possible, and thus a PET drawn fiber and a tire-cord having superior dimensional stability and mechanical properties can be obtained. Further, a reduction in physical properties or performances during the manufacturing process can be minimized by controlling the melt-spinning conditions such as melt viscosity, spinneret hole area or the like within the specific range.
[0031] Therefore, according to the manufacturing method of another embodiment, the PET drawn fiber of one embodiment for providing the PET tire-cord showing superior strength and dimensional stability can be manufactured, although the PCI process is omitted.
[0032] Hereinafter, each step of the manufacturing method of the PET drawn fiber according another embodiment will be described in detail.
[0033] In the method for manufacturing the PET drawn fiber according to another embodiment, melt-spinning of a polymer including PET is first performed so as to produce an undrawn fiber. In this regard, the polymer including PET may include various additives, and according to another embodiment, a polymer having a PET content of 90 mol % or more may be used. This polymer is used to manufacture a drawn fiber and a tire-cord having excellent physical properties described below.
[0034] Further, the PET polymer may have a melt viscosity of approximately 3000 to 5000 poise or approximately 3200 to 4500 poise at approximately 290° C. and at a shear rate of approximately 1000 s −1 . This melt viscosity can be measured using a rheometer of RHEO-TESTER 2000. In the above melt viscosity range, the measurement conditions of the temperature of approximately 290° C. and the shear rate of approximately 1000 s −1 correspond to the conditions under which the melt-spinning process is practically carried out. As the PET polymer having high melt viscosity under such conditions is used, advantages of the ultra high-speed spinning technique can be more effectively achieved. As a result, a PET drawn fiber and a tire-cord having superior mechanical properties such as strength or the like can be obtained by the above manufacturing method.
[0035] However, in order to prevent breakage due to an excessively increased discharge pressure of a pack upon spinning, it is preferable that a polymer having a melt viscosity of approximately 5000 poise or less is used in the melt spinning under the above conditions. That is, if the melt viscosity of the PET polymer is too high, it is difficult to discharge the polymer upon melt-spinning, leading to deterioration in spinnability. In order to solve these problems, the spinning temperature can be increased, but it is difficult to manufacture the drawn fiber and the tire-cord having superior strength and dimensional stability due to thermal degradation. On the contrary, when a polymer having an excessively low melt viscosity is used, sufficient polymer discharge pressure is not secured, and thus it is difficult to bring out the advantages of the ultra high-speed spinning technique and to manufacture the tire-cord having high strength, dimensional stability or the like.
[0036] In the above described manufacturing method, the ultra high-speed spinning technique is applied to the polymer having high melt viscosity so as to obtain an undrawn fiber having high crystallinity or the like, and through a subsequent process, the drawn fiber and the tire-cord having excellent strength and dimensional stability can be manufactured. In order to achieve high crystallinity or the like of the undrawn fiber, melt-spinning of the polymer can be carried out at a spinning speed of approximately 3000 to 4000 m/min, or approximately 3500 to 4000 m/min. That is, in order to achieve physical properties such as high crystallinity or productivity of the undrawn fiber, it is preferable that the spinning speed of 3000 m/min or higher is applied, and in order to provide a minimum cooling time and high strength required for the production of the undrawn fiber, it is preferable that the spinning speed of 4000 m/min or lower is applied under the limited winding speed.
[0037] Further, in the manufacturing method of another embodiment, the above described melt-spinning process can be carried out through a spinneret having a spinneret hole area of approximately 0.18 to 0.4 mm 2 /De or approximately 0.23 to 0.35 mm 2 /De. As the spinneret having such spinneret hole area is used, the discharge speed of the polymer and a speed difference of rolls in the subsequent drawing process are controlled to more effectively control the spinning draft. As a result, the oriented crystallization phenomenon of the PET polymer due to application of the ultra high-speed spinning technique can be more effectively generated, thereby manufacturing the PET drawn fiber and the tire-cord having superior strength, dimensional stability or the like.
[0038] Furthermore, a discharge pressure of a pack upon spinning can be properly controlled by controlling the spinneret hole area so as to greatly reduce the problems due to the increased discharge pressure and to overcome a limitation in the application of the drawing ratio, considerably. Previously, when an undrawn fiber was intended to be obtained from a polymer having high viscosity by the ultra high-speed spinning technique, breakage or hairiness may occur due to increased discharge pressure of a pack upon spinning or elastic properties, and as a result, there was a limitation in the application of the polymer having high viscosity. Furthermore, there is a disadvantage that the strength of the drawn fiber and the tire cord is lowered because the restricted drawing ratio is applied. For this reason, although high viscosity and ultra high-speed spinning technique are applied, it is difficult to obtain a tire-cord having excellent strength and dimensional stability. In contrast, when the spinneret having the particular spinneret hole area described above is applied, a loss in the physical properties or performances can be minimized, and a PET drawn fiber and a tire-cord having superior dimensional stability and strength can be manufactured.
[0039] However, if a spinneret having an excessively large spinneret hole area above approximately 0.4 mm 2 /De is applied, non-uniform cooling, a difference in the strength due to the reduced diameter of monofilaments, or deterioration of fatigue performance upon manufacturing the tire-cord may be caused. In the above described melt-spinning process, the discharge pressure of the polymer passed through the spinneret can be controlled to approximately 1500 to 3000 psi, or approximately 1700 to 2800 psi. Such discharge pressure can be controlled by controlling the spinneret hole area of the spinneret or viscosity of the polymer described above, or scale or design of the spinneret. When the polymer discharge pressure upon melt-spinning is controlled within the above described proper range, the PET polymer is stably discharged upon melt-spinning, and the spinning draft is more effectively increased to further maximize the advantages of ultra high-speed spinning technique. As a result, it is possible to provide a PET drawn fiber and a tire-cord having more improved dimensional stability, strength or the like. However, if the discharge pressure is too high, operation becomes unstable due to leakage of the pack, or an excessive increase in the spinning draft may cause deterioration of physical properties, non-uniformity, furthermore, breakage of the drawn fiber.
[0040] Meanwhile, in the manufacturing method of another embodiment, a drawn fiber can be produced to have a monofilament fineness of 1.8 to 3.5 denier, or 1.8 to 3.0 denier through the spinneret having the above described spinneret hole area. Therefore, the initial discharge speed of the polymer in the spinneret can be reduced, the orientation of the undrawn fiber is further improved, and the spinning draft is more effectively increased to further improve the dimensional stability of the manufactured drawn fiber and tire-cord. In addition, more uniform and efficient cooling is possible due to the high monofilament fineness, and as a result, a reduction in the physical properties of the drawn fiber and the tire-cord can be reduced, and the drawn fiber and the tire-cord having a uniform cross-sectional area and physical properties can be provided. Therefore, according to application of the ultra high-speed spinning technique, excellent physical properties can be optimized and achieved. In particular, for example, when a drawn fiber and a tire-cord having high fineness of approximately 1000 denier or more are manufactured, it is also possible to provide a tire-cord having physical properties such as uniform and excellent strength, dimensional stability or the like.
[0041] If the monofilament fineness becomes 1.8 denier or less during the spinning process, the excessively low monofilament fineness increases the fiber entanglement due to air during spinning, thereby increasing the possibility of hairiness. In addition, breakage of the filament may easily occur due to post-processing which provides a twist and a breakage may easily occur due to repeated fatigue and fatigue resistance may be decreased. In addition, in order to provide the product discharged through the spinneret with the uniform cooling by the cooling air and to improve the dimensional stability due to increased spinning draft by reducing the discharge speed of the polymer, the monofilament fineness is preferably 3.5 denier or less.
[0042] Meanwhile, in the above melting-spinning step, a predetermined PET polymer is discharged through the spinneret as described above, and then passed through a warming section of approximately 60 to 120 mm and a quenching section, and melt-spun with the above described speed of approximately 3000 to 4000 m/min.
[0043] In the process of manufacturing the undrawn fiber by melt-spinning and cooling the PET polymer under the above described conditions, cooling may be carried out by supplying cooling air of approximately 15 to 60° C. The supply of the cooling air is preferably controlled at approximately 0.4 to 1.5 m/s under the cooling air temperature conditions.
[0044] The undrawn fiber manufactured by the above process may show high crystallinity up to approximately 40% and low amorphous orientation factor up to approximately 0.07. As the undrawn fiber having these crystalline properties is obtained through the above described melt-spinning process, and then the drawn fiber and the tire-cord are manufactured, the tire-cord showing superior strength and dimensional stability can be manufactured. The technical principle can be inferred as follows.
[0045] Basically, the PET polymer constituting the undrawn fiber has a partially crystallized structure, and is composed of crystalline regions and amorphous regions. However, the degree of crystallization of the undrawn fiber obtained under the controlled melt-spinning conditions is higher than that of the known undrawn fiber because of the oriented crystallization phenomenon. Due to such high crystallinity, the drawn fiber and the tire cord prepared from the undrawn fiber can show superior mechanical properties and dimensional stability.
[0046] At the same time, the undrawn fiber may show the amorphous orientation factor which is largely lower than that of the known undrawn fiber.
[0047] The amorphous orientation factor means the degree of orientation of the chains included in the amorphous region of the undrawn fiber, and it has low value as the entanglement of the chains of the amorphous region increases. Generally, the drawn fiber and the tire-cord manufactured from the undrawn fiber show low shrinkage stress as well as low shrinkage rate, because the degree of disorder increases as the amorphous orientation factor decreases and the chains of the amorphous region becomes not a strained structure but a relaxed structure. However, the undrawn fiber obtained under the above described melt-spinning conditions includes more cross-linking bonds per a unit volume, because the molecular chains constituting the undrawn fiber slip during the spinning process and form a fine network structure. On this account, the undrawn fiber may become the structure of which the chains of the amorphous region are strained in spite of the lower amorphous orientation factor, and thus it shows developed crystalline structure and superior orientation characteristics due to this. Therefore, the undrawn fiber as well as the drawn fiber and the tire-cord manufactured therefrom are able to show low shrinkage rate and high shrinkage stress and modulus, and as a result, the tire cord showing superior dimensional stability can be manufactured.
[0048] Furthermore, the above physical properties according to application of the ultra high-speed spinning technique can be more effectively achieved and maintained by controlling the spinneret hole area of the spinneret or the melt viscosity of the PET polymer measured under the specific conditions within the predetermined range, as described above. Therefore, according to one embodiment of the present invention, it is possible to provide a drawn fiber and a tire-cord having excellent strength and dimensional stability and uniform physical properties. Therefore, it is possible to manufacture a tire without application of the PCI process. Furthermore, when a drawn fiber and a tire-cord having high fineness are manufactured according to the recent requirements in the related art, excellent and uniform physical properties can be achieved, which greatly contributes to improvement in physical properties of the tire and simplification of the process.
[0049] Meanwhile, after production of the above described undrawn fiber, the undrawn fiber is drawn to produce the PET drawn fiber. The drawing step may be performed by Direct Spinning & Drawing (hereinafter, referred to as ‘DSD’) composed of a single consecutive process of spinning and drawing according to the typical production process of the drawn fiber.
[0050] Further, the drawing step is preferably performed at a drawing ratio of approximately 1.5 to 1.8 times, or approximately 1.55 to 1.75 times. That is, in order to produce the tire-cord having superior strength and dimensional stability, the drawing ratio is preferably approximately 1.5 times or more. However, if a high drawing ratio is applied, it is difficult to manufacture a tire-cord having excellent dimensional stability due to high orientation characteristics of the amorphous region. If the ultra high-speed spinning technique is applied at a spinning speed of approximately 3000 to 4000 m/min, there is a limitation in control of the drawing ratio according to a spinning machine. Further, the drawing ratio is preferably approximately 1.8 or less because the crystallinity of the undrawn fiber may increase due to the fineness decrease of monofilament caused by the application of high-multi filament method.
[0051] The PET drawn fiber obtained by the above described preparation method may have a relatively high fineness of the total fineness of approximately 1000 to 4000 denier and also have the monofilament fineness of approximately 1.8 to 3.5 denier. In particular, when the PET drawn fiber has such high fineness, it is able to exhibit excellent physical properties such as high tensile strength, intermediate elongation, breaking elongation or the like, as described above. Therefore, it meets the requirement in the art for the tire-cord having superior strength and dimensional stability as well as high fineness.
[0052] Meanwhile, according to another embodiment of the present invention, a method for manufacturing a PET tire-cord using the above described PET drawn fiber and the manufacturing thereof, and a manufacturing method thereof are provided. The method for manufacturing the PET tire-cord may include the steps of producing the PET drawn fiber by the above described method; twisting the drawn fibers to produce the twisted fibers; and dipping the twisted fiber in an adhesive solution, followed by heat treatment.
[0053] In the manufacturing method of the tire-cord, the twisting step may be, for example, carried out by ‘Z’ twisting the drawn fiber having a total fineness of approximately 1000 to 4000 denier with a twisting level of approximately 100 to 500 TPM (twist per meter), and ‘S’ twisting 1 to 3 ply of the ‘Z’ twisted fibers with a twisting level of approximately 100 to 500 TPM so as to prepare a twisted yarn having a total fineness of approximately 2000 to 8000 denier.
[0054] Furthermore, an adhesive solution which is conventionally used for manufacturing a tire cord, for example, a resorcinol-formaldehyde-latex (RFL) adhesive solution, may be used as the adhesive solution. Further, the heat treatment process may be carried out at a temperature of approximately 220 to 260° C. for approximately 90 to 360 seconds, preferably at a temperature of approximately 230 to 250° C. for approximately 90 to 240 seconds, and more preferably at a temperature of approximately 235 to 250° C. for approximately 90 to 180 seconds. Further, the heat treatment process may be carried out under a tension of approximately 0.1 kg/cord to 4.0 kg/cord. To provide the effect of Relax in the final heat treatment region, the process may be carried out under a tension of approximately 0.1 kg/cord to 2.0 kg/cord.
[0055] The tire-cord can be manufactured by the above method. However, the individual steps are only an example of the manufacturing method of the tire-cord, and it is apparent that steps typically performed in the art to which the present invention pertains may be further included prior to or after each step.
[0056] Meanwhile, according to another embodiment of the present invention, a PET tire-cord manufactured by the above described method is provided. The tire-cord may have a PCI index of approximately 1.5% or less, or approximately 0.3 to 1.3%, or approximately 0.6 to 1.2%, in which the PCI index is defined as a difference between a dry heat shrinkage rate after heat treatment at approximately 180° C. for 2 minutes under a load of approximately 0.01 g/d and a dry heat shrinkage rate after heat treatment at approximately 180° C. for 2 minutes under a load of approximately 0.1 g/d. Further, its dry heat shrinkage rate after heat treatment at approximately 180° C. for 2 minutes under a load of approximately 0.01 g/d may be approximately 1.5% or less, or approximately 0.2 to 1.5%, or approximately 0.5 to 1.5%, and its dry heat shrinkage rate after heat treatment at approximately 180° C. for 2 minutes under a load of approximately 0.1 g/d may be approximately 1.0% or less, or approximately 0.1 to 1.0%, or approximately 0.2 to 1.0%. In addition, the tire-cord may be a tire-cord which can be used for manufacturing a tire without the PCI process after tire vulcanization.
[0057] In still another embodiment, such low PCI index indicates that a shrinkage rate difference is small although the load or temperature applied to the tire-cord is greatly changed, which reflects that excellent uniformity of the tire is maintained and the tire-cord exhibits excellent dimensional stability, after tire vulcanization performed under the predetermined load and temperature. These physical properties have never been achieved when the tire-cord was not subjected to the PCI process.
[0058] However, according to still another embodiment of the present invention, a tire-cord meeting the above described range of the PCI index can be provided, and therefore, the PCI process can be omitted after tire vulcanization. In other words, dimensional stability of the tire-cord is optimized without the PCI process, and thus the PCI process can be omitted. Therefore, since the tire-cord according to still another embodiment of the present invention is able to show excellent dimensional stability suitable for the body ply, the PCI process can be omitted, and a reduction in tire productivity due to the PCI process or a quality reduction due to omission of the PCI process can be prevented.
[0059] Meanwhile, the above described tire-cord according to still another embodiment may have a total fineness of approximately 2000 to 8000 denier, a tensile strength of approximately 9.0 to 17.0 g/d, or approximately 11.0 to 16.0 g/d, an intermediate elongation of approximately 3.0 to 5.5%, or approximately 3.6 to 5.0%, and a breaking elongation of approximately 10.0% or more, or approximately 14.0 to 20.0% under a load of 2.25 g/d. That is, although the tire-cord has a high fineness of approximately 2000 denier or more, it is able to exhibit the optimized physical properties such as excellent tensile strength and elongation.
[0060] The above described PET tire-cord meets the requirement in the art for the tire-cord having excellent physical properties of high strength and excellent dimensional stability. In particular, the tire-cord can be very preferably used as a body ply cord for a pneumatic tire so as to very effectively support the vehicle's entire load. However, the use of the tire-cord is not limited thereto, and it is obvious that the tire-cord can be used in other applications such as cap ply.
[0061] According to the present invention, a tire-cord having superior dimensional stability and strength, and a manufacturing method thereof can be provided. This tire-cord is preferably used as body ply cord for a pneumatic tire so as to improve uniformity of the tire, and the PCI process can be omitted after tire vulcanization to further improve productivity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0062] FIG. 1 is a partial cut-away perspective view illustrating a structure of a general tire; and
[0063] FIG. 2 is a schematic view illustrating a structure of a shrinkage behavior tester used for measuring dry heat shrinkage rate.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0064] Hereinafter, the preferred Examples are provided for better understanding. However, these Examples are for illustrative purposes only, and the invention is not intended to be limited by these Examples.
[Preparation of Drawn Fiber]
EXAMPLE 1
[0065] A PET polymer having a melt viscosity of 3200 poise at 290° C. and at a shear rate of 1000 s −1 was used. At this time, the melt viscosity of the PET polymer was measured and confirmed using a rheometer of RHEO-TESTER 2000. The PET polymer having the melt viscosity was melt-spun through a spinneret having a spinneret hole area of 0.3 mm 2 /De at a speed of 3500 m/min, and discharged at a discharge pressure of 1800 psi. This discharge pressure was examined by HMI program of Kolon Industries Inc. After the melt-spinning, the polymer was cooled to produce an undrawn fiber. This undrawn fiber was drawn at a drawing ratio of 1.67, followed by heat setting and winding so as to produce a PET drawn fiber having a monofilament fineness of 2.6.
[0066] The PET tire cord of Example 1 having a total fineness of 2000 denier was prepared by Z-twisting the drawn PET fibers of which the total fineness was 1000 denier with the twisting level of 410 TPM, S twisting 2 plies of the Z twisted fibers with the same twisting level, dipping and passing the same through an RFL adhesive solution, and drying and heat-treating the same.
[0067] The composition of the RFL adhesive solution and the conditions of the drying and the heat treatment followed the conventional conditions for treating a PET cord.
EXAMPLES 2 TO 5
[0068] The PET drawn fibers and tire cords of Examples 2 to 5 were prepared substantially according to the same method as in Example 1, except that the melt viscosity of the PET polymer at 290° C. and at a shear rate of 1000 s −1 , the spinneret hole area of the spinneret, the discharge pressure of the PET polymer from the spinneret, the spinning speed, the monofilament fineness, and the drawing ratio were changed in the preparation process of the PET drawn fiber as in the following Table 1.
COMPARATIVE EXAMPLES 1 TO 3
[0069] The PET drawn fibers and tire cords of Comparative Examples 1 to 3 were prepared substantially according to the same method as in Example 1, except that the melt viscosity of the PET polymer at 290° C. and at a shear rate of 1000 s −1 , the spinneret hole area of the spinneret, the discharge pressure of the PET polymer from the spinneret, the spinning speed, the monofilament fineness, and the drawing ratio were changed in the preparation process of the PET drawn fiber as in the following Table 1.
[0070] The conditions for the preparation process of the PET drawn fibers, which were applied to Examples 1 to 5 and Comparative Examples 1 to 3, are shown in the following Table 1.
[0000]
TABLE 1
Spinneret
Melt
Discharge
Spinning
Monofilament
hole area
viscosity
pressure
speed
Drawing
fineness
Conditions
(mm 2 /De)
(poise)
(psi)
(m/min)
ratio
(denier)
Example 1
0.3
3200
1800
3500
1.67
2.6
Example 2
0.3
3500
2300
3550
1.65
2.6
Example 3
0.3
4500
2700
3650
1.6
2.6
Example 4
0.25
3500
2600
3550
1.65
3
Example 5
0.35
3500
2000
3600
1.62
2.3
Comparative
0.15
3500
3300
3400
1.72
4
Example 1
Comparative
0.3
6000
3500
3300
1.71
2.6
Example 2
Comparative
0.3
2000
1400
3500
1.6
2.6
Example 3
[0071] [Measurement of Physical Properties of Drawn Fiber]
[0072] Physical properties of the drawn fibers according to Examples 1˜5 and Comparative Examples 1˜3 were measured by the following methods.
[0073] 1) L/S (kg/%): each drawn fiber was heat treated at a temperature of 180° C. and under an initial load of 0.02 g/d for 2 minutes using a shrinkage behavior tester (also used for measurement of dry heat shrinkage rate; manufacturer: TESTRITE, model: MK-V), and then LASE (kg) was measured using a universal tensile tester in accordance with standard ASTM D885. A dry heat shrinkage rate was also measured while the drawn fiber heat-treated for 2 minutes was maintained in an oven at 180° C. without the initial load. FIG. 2 is a schematic view illustrating a structure of a shrinkage behavior tester used for measuring dry heat shrinkage rate. As a result of the measurement, an L/S value defined as the following Equation 1 was calculated.
[0000] L/S =LASE(kg)/shrinkage rate(%) [Equation 1]
[0074] wherein LASE (kg) represents Load at Specific Elongation when elongation of the drawn fiber is 5%, after heat treatment for 2 minutes, and shrinkage rate (%) represents a dry heat shrinkage rate measured while the drawn fiber is maintained at the temperature of 180° C. without the initial load, after heat treatment for 2 minutes.
[0075] 2) Tensile strength (g/de): the strength of the fiber was measured using a universal strength tester in accordance with standard ASTM D885.
[0076] 3) Intermediate elongation (%) and Breaking elongation (%): the intermediate elongation and breaking elongation were measured under a load of 4.5 g/de using a universal strength tester in accordance with standard ASTM D885.
[0077] 4) Coefficient of variation (C.V %): the coefficient of variation was measured using an AnalySIS TS Auto 5.1 program of Olympus Soft Imaging Solutions.
[0078] The physical properties of the PET drawn fibers according to Examples 1˜5 and Comparative Examples 1˜3, measured as above, are shown in the following Table 2.
[0000]
TABLE 2
Intermediate
Coefficient
elongation@
Breaking
of
L/S
Strength
4.5 g/d
elongation
variation
Conditions
(kg/%)
(g/d)
(%)
(%)
(%)
Example 1
2.2
8.0
5.2
10.7
6.5
Example 2
2.7
8.2
5.4
11.3
6.3
Example 3
2.9
8.3
5.5
11.6
5.8
Example 4
2.8
7.8
5.7
11.8
5.9
Example 5
2.4
8.3
5.4
11.1
6.6
Comparative
1.8
7.5
5.6
12.1
5.5
Example 1
Comparative
1.6
7.8
5.7
12.5
5.4
Example 2
Comparative
1.2
6.7
5.8
13.7
7.3
Example 3
[0079] As shown in Tables 1 and 2, those of Comparative Examples 1 to 3 were prepared under the conditions of the melt viscosity of the PET polymer, the spinneret hole area of the spinneret, the discharge pressure or the monofilament fineness which are different from those of Examples.
[0080] Comparative Examples 1 to 3 did not satisfy the L/S value of 2.0 kg/% or more, and thus their dimensional stability was unsatisfactory and the strength of the drawn fiber was poor or fiber quality was poor, leading to deterioration in processability.
[0081] In Comparative Example 2, the PET polymer having a high melt viscosity was applied and thus the discharge pressure was excessively increased upon spinning, which is likely to cause breakage and a reduction in physical properties. In addition, the high spinning temperature of 300° C. for preventing the pressure increase caused a reduction in dimensional stability due to polymer degradation at high temperature.
[0082] In Comparative Example 3, the PET polymer having a low melt viscosity was applied and spun, resulting in low strength of the PET drawn fiber and poor dimensional stability and coefficient of variation.
[0083] In contrast, the PET drawn fibers of Examples 1 to 5 satisfied the L/S value of 2.0 kg/% or more to exhibit excellent dimensional stability, excellent strength, and proper intermediate elongation and breaking elongation.
[0084] [Measurement of Physical Properties of Tire-Cord]
[0085] Physical properties of the tire-cords according to Examples 1 to 5 and Comparative Examples 1 and 2 were measured by the following methods, and the measured physical properties are shown in the following Table 3.
[0086] 1) Tensile strength (g/de): the strength of the cord was measured using a universal strength tester in accordance with standard ASTM D885.
[0087] 2) Intermediate elongation (%) and Breaking elongation (%): the intermediate elongation and breaking elongation were measured under a load of 2.25 g/de using a universal strength tester in accordance with standard ASTM D885.
[0088] 3) Dry heat shrinkage ratio (%): a dry heat shrinkage rate after 2 minutes at a temperature of 180° C. and under a load of 0.01 g/d and a dry heat shrinkage rate after 2 minutes at a temperature of 180° C. and under a load of 0.1 g/d were measured using a shrinkage behavior tester (manufacturer: TESTRITE, model: MK-V) in accordance with standard ASDM D4974, respectively. In the same manner, a dry heat shrinkage rates after 2 minutes at a temperature of 180° C. and under a load of 0.05 g/d and 0.113 g/d were measured, respectively. FIG. 2 is a schematic view illustrating a structure of a shrinkage behavior tester used for measuring dry heat shrinkage rate.
[0089] 4) PCI Index: PCI index was calculated from a difference between the dry heat shrinkage rate under a load of 0.01 g/d and the dry heat shrinkage rate under a load of 0.1 g/d measured by the above method.
[0000]
TABLE 3
Dry heat
Dry heat
Dry heat
Dry heat
shrinkage
shrinkage
shrinkage
shrinkage
Intermediate
Breaking
rate(%)
rate(%)
rate(%)
rate(%)
PCI
Strength
elongation
elongation
under load
under load
under load
under load
Index
(g/d)
(@4.5 kg, %)
(%)
of 0.01 g/d
of 0.05 g/d
of 0.1 g/d
of 0.113 g/d
(%)
Example 1
13.6
4.6
18.6
1.1
0.8
0.3
0.2
0.8
Example 2
14.2
4.5
19.2
1
0.8
0.3
0.2
0.7
Example 3
15.0
4.3
19.4
1.4
0.8
0.2
0.2
1.2
Example 4
12.8
4.6
18.9
1.2
0.9
0.4
0.3
0.8
Example 5
15.2
4.1
15.3
1.5
1
0.5
0.5
1
Comparative
16.3
4.1
13.6
3.1
1.9
1
0.8
2.1
Example 1
Comparative
15.8
4.5
18.8
2.8
1.6
1
0.7
1.9
Example 2
[0090] Referring to Tables 1 to 3, in Comparative Examples 1 and 2, the tire-cords showed a high dry heat shrinkage rate under a load of 0.01 g/d due to poor dimensional stability and a high PCI Index, which is a difference from the dry heat shrinkage rate under a load of 0.1 g/d. Consequently, if a PCI process after tire vulcanization is omitted, uniformity and quality of the tire could be reduced.
[0091] In contrast, it was found that the tire-cords applied with the drawn fibers according to Examples 1 to 5 showed excellent strength and low PIC Index, and thus its dimensional stability was very excellent and additional PCI process was not required after tire vulcanization. | The present invention relates to a poly(ethyleneterephthalate) drawn fiber, which is able to provide a poly(ethylene terephthalate) tire-cord showing superior strength and dimensional stability without a PCI process after tire vulcanization, a poly(ethylene terephthalate) tire-cord and a manufacturing method thereof. The poly(ethyleneterephthalate) drawn fiber has a predetermined L/S value of 2.0 kg/% or more after heat treatment at a temperature of 180° C. under an initial load of 0.02 g/d for 2 minutes. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to a looper control system for controlling the looper operational angle and the tension between stands in a continuous rolling mill.
In a continuous rolling mill, as the important element for evaluating the quality of products, there are thickness, width, crown, and flatness of strips. Since the value of the tension between stands exerts a large influence on these elements, it is desirable to keep it constant as far as possible. For this reason, in the hot continuous rolling mill, such control is conducted to absorb changes in the tension value by looper mechanisms provided between respective rolling mill stands.
Hitherto, in a looper control system for a continuous rolling mill provided with loopers between stands, the tension between stands, i.e., interstand tension is controlled by allowing the looper drive motor to generate a predetermined torque, and by changing the difference between interstand speeds of the main motor, to adjust the looper operational angle. However, with this system, the length of material between stands is changed by modifying the speeds of the main motor nearby the looper. As a result, the looper operational angle control is carried out following the change in the strip length between stands. Accordingly, this leads to the drawback that the interstand tension fluctuation caused by the looper operational angle control becomes large.
Further, when a control for looper operational angle is carried out in order to reduce such a tension fluctuation, the response in the looper operational angle control must be lowered, resulting in the drawback that the control cannot cope with high frequency disturbances.
On the other hand, in order to solve the above-mentioned problems, as a looper control system to which the optimum control theory is applied, there have been proposed systems, such as, for example, disclosed in the Japanese Patent Publication No. 44129/84, the Japanese Patent Applications Laid Open Nos. 86919/83, 18213/84, 118214/84.
Japanese Patent Publication No. 44129/84 is directed to a system constructed to handle, as the state variable in the optimum control theory, looper operational angular velocity, looper operational angle, tension between stands, and difference between interstand material speeds, thus, to constitute a feedback based on only the proportional operation. However, where there is steadily a relatively large disturbance, or where the target tension changes with time, any offset is produced because there is no integral term, and results in lowered controllability. In an extreme case, a break in the strip results.
The Japanese Patent Laid Open No. 86919/83 is directed to a system constructed to add the integrating operation to the technique disclosed in the Japanese Patent Publication No. 44129/84 to thereby set a reference value by itself and remove the above-mentioned offset.
In these systems disclosed in the Japanese Patent Publication No. 44129/84 and the Japanese Patent Application Laid Open No. 86919/83, the proportional operation for deviation in connection with the reference value of the Taylor expansion used when linearly approximating the controlled system is performed. Accordingly, there remain problems to be solved, such as, for example, it is necessary to input this reference value when actually carrying out a control, working stability is poor because the proportional operational components appear to a great extent at the time of the start of control where the deviation from the reference value is large, and the like.
In the Japanese Patent Laid Open No. 118213/84, with a view to solving this problem, there is proposed a looper control system in a form to reconsider the control model from the standpoint of integral-type optimum regulator theory and perform the integral operation by integrating a deviation from the target value with respect to the variable having a control target value, and to perform the proportional operation with respect to the deviation from a lock-on value (a value at the time of start of control) subject to the proportional operation.
In addition, to Japanese Patent Application Laid Open No. 118214/84 is directed to a system to employ the looper drive motor rotational speed control in place of the looper drive motor current control unit in the configuration of Japanese Patent Application Laid Open No. 118213/84 and thereby provide an improved stability of the looper operational angle.
However, when an attempt is made to apply the above-described four proposed systems constructed from the standpoint of the optimum control of an actual rolling process, there are the problems that the control system is apt to be affected by the influence of noise of the detection signal because there are many feedback loops, that it takes much time for adjustment of the control gain, and that the control with respect to the rolling process characteristic change followed by the rolling speed change must be adjusted.
Further, the conventional looper control system only considers the rotational speed of the main motor in determining the optimum gain. However, because of roll gap correction operation by the automatic gage control (AGC), a sudden change in the tension would occur, resulting in the possibility that an extreme tension may take place. However, any effective action is not taken in the conventional system.
In addition, an effectively functioning angular range exists in the looper. That is, when a looper angle exceeds above a predetermined angle, there is the possibility that the looper may be broken. In contrast, when the looper angle is below the predetermined angle, the looper cannot entirely conduct the adjustment of the tension. Accordingly, it is necessary to operate the looper within a fixed allowable range with respect to the looper angle. However, any effective action is also not taken in this respect in the conventional system.
SUMMARY OF THE INVENTION
Accordingly, an object of this invention is to provide a looper control system for a continuous rolling mill which is simple from the viewpoint of optimum control and has the function of compensating for various rolling process characteristic changes so that the control system conforms with implementation of the actual process.
Another object of this invention is to provide a looper control system for a continuous rolling mill capable of effectively controlling the looper at all times.
In accordance with this invention, there is provided a looper control system for a continuous rolling mill comprising: a section for performing the integral operation of respective deviations between actual measured values and target values with respect to the tension and the looper angle, and the proportional operation of respective deviations between the tension, the looper operation angle, and the rotational speed of the looper motor at the time of start of control and those at the present control period to synthesize values thus obtained to deliver them to the looper current control unit or the looper control unit, a section for performing the integral operation and the proportional operation similar to the above to synthesize the values thus obtained to deliver them to the main motor speed control unit; an optimum gain setting unit for correcting respective proportional gains in dependency upon the speed of the main motor.
In accordance with this invention, there is also provided a looper control system for a continuous rolling mill comprising: a section for performing the integral operation of respective deviations between actual measured values and target values with respect to the tension and the looper angle, and the proportional operation of respective deviations between the tension, the looper operation angle, and the rotational speed of the looper motor at the time of start of control and those at the present control period to synthesize values thus obtained to deliver them to the looper current control unit or the looper control unit, a section for performing the integral operation and the proportional operation similar to the above to synthesize the values thus obtained to deliver them to the main motor speed control unit; an optimum gain setting unit for correcting respective proportional gains in dependency upon the speed of the main motor; and a section for altering the optimum gain by the fact that the tension and/or the looper angle are extreme.
This invention employs a scheme to construct state vectors required for optimum control from only the respective measured signals of the looper operational angle, the tension between stands, and the looper drive motor speed to thereby hold down the number of feedback loops to a small value. Accordingly, the control system has a little possibility of undergoing the influence of noise in the detection signal, and the number of control gains to be adjusted is smaller than that for the prior art. For this reason, the configuration of the control system is simplified and it is sufficient that the time required for adjustment of the control gain be extremely short. Moreover, since the number of feedback loops is small, the control system has a little possibility of undergoing the influence of noise in the detection signals. Further, since the deviation from the lock-on value is used instead of the deviation from the steady state value in carrying out the proportional operation, the stability in control at the time of start of the control is excellent. Furthermore, setting of the optimum control gain for the rolling process characteristic change followed by the rolling speed change is made, thereby permitting the control system to respond at a high speed at all times irrespective of the rolling speed.
Further, since this invention also detects the extreme tension state and the extreme looper angle state to effectively take a measure, the high rolling quality can be maintained.
In addition, since an approach is employed to calculate and store the integral gain and the proportional gain at the two rolling speeds, e.g., at the threading speed and at the time of the rolling maximum speed using rolling information such as rolling schedule, etc. determined in advance before a material to be rolled reaches the continuous rolling mill in order to carry out compensation of the control gain with respect to the rolling process characteristic change followed by the rolling speed change, to thus set a linearly interpolated integral gain and proportional gain using the speed target value and the actual measured value of the main motor during rolling, this control system has little possibility of undergoing the influence of the rolling process characteristic change.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a block diagram showing a first embodiment of a looper control system according to this invention;
FIGS. 2A to 2J are graphs showing the relationships between the rolling speed and control gains, respectively;
FIGS. 3A to 3L are graphs showing the operations of the looper control system according to this invention at the time when the tension is in an extreme state, respectively;
FIGS. 4A to 4L are graphs showing the operations of the looper control system according to this invention at the time when the looper angle is in an extreme state; and
FIG. 5 is a block diagram showing a second embodiment of a looper control system according to this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a block diagram showing an embodiment of this invention. In FIG. 1, a looper current control unit (looper ACR) 1 controls a looper armature current I flowing in a looper drive motor 2 to thereby drive a looper mechanical system 3. Since the arrangement and the function of the looper mechanism itself is well known, the general description thereof is omitted here.
On the other hand, a main speed control unit (main motor ASR) 4 controls the rotational speed of a main motor 5 for driving the rolling roll. An interstand tension generation mechanism 6 generates an interstand tension T on the basis of a rotational speed N of the main motor, in other words, expresses a transfer function from the rotational speed N to the interstand tension T. This transfer function is determined by the mechanical dimensions and the size of a material subject to rolling of the rolling mill. Further, F t in a block 7 represents a coefficient for converting an interstand tension T to a looper motor load current and its value is determined by the size of a material subject to rolling and a looper operational angle θ, etc. In addition, F a in block 8 represents a change in the looper operational angle θ to a rotational speed of the main motor and its value is determined by the mechanical dimensions of the rolling mill and a looper operational angle. These blocks 7 and 8 are blocks indicating the interference between the looper operational angle θ and the interstand tension T.
As seen from the above, the blocks 1 to 8 are blocks that express the equipment condition and the rolling process. With such a configuration, the actual interstand tension value T and the looper operational angle θ are controlled so that they become equal to the interstand tension target value T r and the looper operational angle target value θ r , respectively. In addition to the configuration, a looper control unit 100 is provided on the preceding side of the main motor ASR and the looper ACR.
The interstand tension target value T r is subtracted from the actual interstand tension value T at a subtracter 31. The subtracted result is delivered to an integrator 13 via the block 9 indicative of the integral operation gain K 11 and an adder 33, and is, on the other hand, delivered to the integrator 14 via the block 10 indicative of the integral operation gain K 21 and an adder 34.
The looper operation target value θ r is subtracted from the actual looper operational angle value θ at a subtracter 32. The subtracted result is delivered to the integrator 14 via the block 12 indicative of the integrating operation control gain K 22 and the adder 34, and is, on the other hand, delivered to the integrator 13 via the block 11 indicative of the integral operation control gain K 12 and the adder 33.
The interstand tension lock on value T o is subtracted from the actual interstand tension value T at a subtracter 38. The subtracted result is delivered to an adder 15 via a block 17 having a proportional gain F 1 , and is delivered to an adder 16 via a block 20 having a proportional gain F 4 . It is to be noted that the lock-on value denotes a value stored at the time of start of control. The looper operation angle lock on value θ o is subtracted from the actual looper operation angle value θ at a subtracter 41. The subtracted result is delivered to the adder 15 via a block 18 having proportional gain F 2 , and is delivered to the adder 16 via a block 21 having a proportional gain F 5 . Further, the looper drive motor rotational speed lock-on value N ao is subtracted from the actual rotational speed value N a of the looper drive motor 2 at a subtracter 40. The subtracted result is delivered to an adder 151 via a block 19 having a proportional gain F 3 and is also delivered to the adder 16 via a block 22 having a proportional gain F 6 .
The added result in the adder 15 is further added to the output of the integrator 13 at an adder 35, resulting in a rotational speed target correction value ΔN r . A rotational speed target value N ro of the main motor at the time of start of control is added to the above-mentioned correction quantity ΔN r at an adder 37. The value thus obtained is delivered to the main motor speed control unit 4 as a rotational speed target value.
On the other hand, the added result in the adder 16 is further added to the output from the integrator 14 a an adder 36, resulting in a looper current target correction quantity ΔI r . Further, a looper current target value I ro at the time of start of control is added to the above-mentioned value ΔI r . The value thus obtained is delivered to the looper current control unit I as a looper current target value.
The rotational speed result value of the main motor 5 is taken out and is then inputted to the optimum gain setting unit 23.
This system further comprises an extreme tension state judgement unit 45 for inputting a detected tension T and a looper detected angle θ to compare the detected tension T with an extreme tension state start tension T min , thus to detect an extreme tension state, a control gain alteration instructing unit 46 for instructing alteration of the control gain on the basis of an output from the extreme tension state judgement unit 45, an extreme looper angle state judgement unit 51 for inputting a looper detected angle θ to compare it with the given maximum looper angle θ max and the given minimum looper angle θ min to judge whether or not the looper angle is in an extreme state, and a looper angle upper and lower limit alteration instructing unit 52 for inputting a judged result outputted from the extreme looper angle state judgement unit to alter the upper and lower limits of the looper angle. An output from the looper angle upper and lower limit alteration instructing unit 52 is delivered to the optimum gain setting unit 23, and is added to the looper operation target value θ r .
In the optimum gain setting unit 23, while monitoring the extreme tension state and the extreme looper angle state, modification or correction of the integral constants K 11 , K 21 , K 12 , K 22 and the proportional constants F 1 , F 2 , F 3 , F 4 , F 5 , F 6 is made in dependency upon changes in the rotational speed N of the main motor. Thus, modified results are delivered to integral constant block 9 to 12 and proportional constant blocks 17 to 22, respectively.
Putting the above in order, it will be seen that the looper current target value correction quantity ΔI r delivered to the looper current control unit 1 in the looper control system according to this invention is obtained by adding output values from respective means shown below by the items (a) to (c).
(a) Means for performing the integral operation by the integral gain K 21 (block 10) and the integrator 14 with respect to a deviation between the actual interstand tension value T and the interstand tension target value T r and the proportional operation by the proportional gain F 4 (block 20) with respect to a deviation between the actual interstand tension value T and the interstand tension lock-on value T o ,
(b) Means for performing the integral operation by the integral gain K 22 (block 12) and the integrator 14 with respect to a deviation between the actual looper operation angle value θ and the looper operation angle target value θ r and the proportional operation by the proportional gain F 5 (block 21) with respect to a deviation between the actual looper operation angle value θ and the looper operation angle lock on value θ o , and
(c) Means for performing the proportional operation by the proportional gain F 6 (block 22) with respect to the actual looper drive motor rotational speed value N a and the looper drive motor rotational speed lock-on value N ao .
The looper current target value correction quantity ΔI r thus obtained and the looper current target value I ro at the time of start of control are added. The added result is delivered as a looper current target value to the looper current control unit 1.
On the other hand, a rotational speed target value correction quantity ΔN r delivered to the main speed control unit 4 is provided by adding output values of the respective means indicated by the following items (d) to (f).
(d) Means for performing the integral operation by the integral gain K 11 (block 9) and the integrator 13 With respect to a deviation between the actual interstand tension value T and the interstand tension target value T r and the proportional operation by the proportional gain F 1 (block 17) with respect to a deviation between the actual interstand tension value T and the interstand tension lock on value T o ,
(e) Means for performing the integral operation by the integral gain K 12 (block 11) and the integrator 13 with respect to a deviation between the looper operation angle result value θ and the looper operation angle target value θ r and the proportional operation by the proportional gain F 2 (block 18) with respect to a deviation between the actual looper operation angle value θ the looper operation angle target value θ r and the proportional operation by the proportional gain F 2 (block 18) with respect to a deviation between the actual looper operation angle value θ and the looper operation angle lock on value θ o , and
(f) Means for performing proportional operation by the proportional gain F 3 (block 19) with respect to a deviation between the actual looper drive motor rotational speed value N a and the looper drive motor rotational speed lock on value N ao .
The rotational speed target value correction quantity ΔN r of the main motor thus obtained and the rotational speed target value N ro of the main motor at the time of start of control are added. The added result is delivered as a rotational speed target value to the main speed control unit 4.
The operation of the looper control system constructed as described above will now be described.
The looper characteristic model of the continuous rolling mill is considered a non-linear model. When this is subjected to Taylor expansion in the vicinity of a certain steady state and is expressed in the form of the linear state equation, it is expressed by the following equations (1) and (2)
x=A.x+B.u (1)
y=C.x (2)
where x denotes a time derivative dx/dt, and x, u and y are vectors represented by the following equations (3), (4) and (5), respectively. Further, A, B and C are 3×3, 3×2, 2×3 constant matrices, respectively.
x=[ΔT, Δθ, ΔN.sub.a ].sup.T (state vector)(3)
u=[ΔN.sub.r, ΔI.sub.r ].sup.T (manipulated vector)(4)
y=[ΔT, Δθ].sup.T (output vector) (5)
where symbol T represents transposition of vector, and symbol Δ represents a deviation from the vicinity of the steady state. Further, notation is given as follows:
T: actual interstand tension value,
θ: actual looper operation angle value,
N a : actual looper driving motor rotational speed value,
N r : rotational speed target value of the main motor,
I r : looper current target value.
It is to be noted that the reason why the actual rotational speed value of the main motor and the actual looper current value are not included in the above-described linear state equation is that the models of the main motor speed control unit and the looper current control unit are omitted for realizing simplification of the model to prepare the linear state equation on the assumption that dynamic characteristics of both the main motor speed control and the looper current control can be ignored because of their quick response.
To apply the optimum control theory, vectors x, u as described below are introduced.
x=[(y-y.sub.r).sup.T, x.sup.T ].sup.T (6)
u=u (7)
In the above equation (6), y r is a target value vector with respect to the output vector expressed by the equation (5). Further, the equations (6) and (7) represent changes in time of the state variable and controlled variable, respectively.
As the state equation with respect to x, u, the following equations are obtained.
x=A.x+B.u (8) ##STR1##
The object of the looper control is to suppress to as small as possible, a deviation from the target value of the interstand tension, a deviation from the target value of the looper operation angle, and a change in the rolling process. Such a problem is said to be the integral type optimum regulator problem. This problem is formulated as the problem to minimize the phosphometric function. ##EQU1## where Q, R are weight coefficient matrices of 5×5 and 2×2 matrices, respectively.
The optimum control rule to minimize the equation (10) is given by the following equation:
u=-R.sup.-1.B.sup.T. P.x (11)
where P is 5×5 matrix, and is a semi-correct solution which satisfies the following Riccati equation.
P.A+A.sup.T. P-P.B.R.sup.-1.B.sup.T.P+θ=O (12)
It is assumed that P is split as follows: ##STR2## On this premise, the above-mentioned equation (11) is rewritten as follows.
u=-R.sup.-1.B.sup.T.P.sub.21.(y-y.sub.r)-R.sup.-1.B.sup.T.P.sub.22.x(14)
Since it is seen from the equation (7) that the actual manipulated vector u is obtained by integrating u, this vector is expressed as follows: ##EQU2## where x o and u o are values at the time of start of control of x and u, respectively. Further, K is 2×2 integral gain matrix, and F is 2×3 proportional gain matrix. These matrices are expressed as follows: ##EQU3##
K 11 , K 12 , K 21 , K 22 of the equation (16) represent integral gains in FIG. 1, and F 1 , F 2 , F 3 , F 4 , F 5 , F 6 represent proportional gains in FIG. 1, respectively.
In this case, vectors x, u, y represent vectors indicative of deviations from the steady state values X s , U s , Y s of the set values, respectively. Accordingly, the equation (15) is expressed by the relative value. However, since it is difficult in actual terms to know in advance the steady state value, it is required to rewrite the equation (15) so that this equation is expressed by the absolute value.
Expressing the absolute value vectors corresponding to the vectors x, u, y by x, u, y gives
X=x+X.sub.x, U=u+U.sub.s, Y=y+Y.sub.2, Y.sub.r =y.sub.r +Y.sub.s,(18)
Accordingly, the optimum control rule expressed by the absolute value is given by the following equation: ##EQU4## The correspondence between the equation (19) and FIG. 1 has already expressed by the equations (16) and (17) in regard to the variables K and F. The correspondence relationships with regard to other variables are expressed as follows:
U=[N.sub.ro +ΔN.sub.r, I.sub.ro +ΔI.sub.r ].sup.T(20)
U.sub.o =[N.sub.ro, I.sub.ro ].sup.T (21)
Y=[T, θ].sup.T (22)
Y.sub.r =[T.sub.r, θ.sub.r ].sup.T (23)
X=[T, θ, N.sub.a ].sup.T (24)
X.sub.o =[T.sub.o, θ.sub.o, N.sub.ao ].sup.T (25)
As is clear from the equation (19), in accordance with this invention, since the steady state values X s , U s , Y s are eliminated in actually conducting a control, it is unnecessary to know their values. If lock on values X o , U o and a target value Y r are instead given, this is sufficient for execution of a desired control. Further, since the element of the state vector is limited to three kinds of signals, the configuration of the control system becomes simplified.
The operations of the integral/proportional operation units of this invention have been described above. The operation of the optimum gain setting unit (the optimum gain setting unit 23 in FIG. 1) will now be described.
The optimum gain setting unit 23 takes thereinto as its input an actual rotational speed value N of the main motor, thus to set integral gains K 11 , K 12 , K 21 , K 22 and F 1 to F 6 . This optimum gain setting unit 23 calculates, by using the above-described equations (12), (13), (16) and (17), a gain at an ordinary threading speed and a gain at the rolling maximum speed from rolling information such as a rolling schedule, etc., at the time when the gain before a material subject to rolling reaches the continuous rolling mill, is calculated, e.g., at the time when the material detector provided on the upstream side of the continuous rolling mill detects the material subject to rolling, thus to store them into a memory area (not shown). It is now assumed that the integral gains at the ordinary threading speed to are represented by K 11A , K 12A , K 21A , K 22A and the proportional gains thereat are represented by F 1A to F 6A , respectively. Further, the integral gains at the rolling maximum speed are represented by K 11B , K 12B , K 21B , K 22B and the proportional gains are represented by F 1B to F 6B , respectively.
The integral gain at an arbitrary time when a material to be rolled is subjected to rolling by the continuous rolling mill is provided by the following equation (26). ##EQU5## where
N: actual rotational speed value of the main motor,
N A : rotational speed set value of the main motor at the ordinary threading time, and
N B : rotational speed set value of the main motor at the time of rolling maximum speed.
Further, the proportional gain is provided by the following equation (27) in accordance with the linear interpolation in the same manner as in the case of the equation (26). ##EQU6##
FIG. 2 is graph for explaining the relationship between the roll peripheral speed, i.e., the rolling speed and various control gains. From these examples of gain calculation, it is clear that sufficiently practical approximate values are obtained by linear interpolation in connection with all the gains. For a time period during which a material to be rolled is subjected to rolling, an optimum gain is set in accordance with the equations (26) and (27) in the optimum gain setting unit 23, whereby a rotational target value correction quantity ΔN r and a looper current target value correction quantity ΔI r of the main motor are determined. The rotational speed N of the main motor 5 and the current I of the looper current control unit 1 are modified so that they follow these correction quantities. Thus, the tension T and the looper operatioon angle θ are controlled so that they are in correspondence with their target values.
Further, a rotational speed setting value of the main motor may be taken as the input to the optimum gain setting unit 23 in place of the actual rotational speed value of the main motor as in the above-described embodiment.
The operation at the time when the tension is in an extreme state will now be described. As previously described, the extreme tension state judgement unit 45 sends a signal indicating that the tension is in an extreme, state to the control gain alteration instructing unit 46. The control gain alteration instructing unit 46 outputs a control gain alteration instruction to the optimum gain setting unit 23 on the basis of the signal indicating that the tension is in an extreme state.
The optimum gain setting unit 23 alters the integral gains K 11 , K 12 , K 21 , K 22 of the blocks 9 to 12 and the proportional gains F 1 to F 6 of the blocks 17 to 22 to tension compensation gains set in advance, respectively. If the tension returns to a normal value, the extreme tension state judgement unit 45 stops outputting the signal indicating that the tension is in an extreme state.
The operation at the time when the tension is in an extreme state of the looper control system 100 shown in FIG. 1 will now be described with reference to FIGS. 3A to 3L. FIG. 3A is a graph showing how the tension of a material subject to rolling varies with time where T r represents a target tension and T min represents a tension set in advance where an extreme state of the tension initially appears. FIG. 3B is a graph showing how the looper angle θ varies with time where θ r represents a target angle, and θ end represents a tension compensation end angle set in advance (θ r and θ end are set to the same value in this figure). FIGS. 3C to 3F are graphs how the absolute values of the integral gains K 11 , K 12 , K 21 , K 22 vary with time, respectively, and FIGS. 3G to 3L are graphs how the absolute values of the proportional gains F 1 to F 6 vary with time, respectively. It is to be noted that these FIGS. 3G to 3L are plotted with respect to the same abscissa showing lapse of time. The timing T 1 on the abscissa indicates the time point when a material subject to rolling is chucked into the upstream stand, and the timing T 2 indicates the time point when that material is chucked into the downstream stand. At this timing T 2 , a tension is produced in the material subject to rolling. At times subsequent thereto, the tension and the looper angle are controlled by the looper control system so that there are in correspondence with target values T r , θ r , respectively. The timing T 3 indicates the time point when the tension of a material subject to rolling lowers for any reason and reaches a value lower than the extreme tension T min . At the time point T 3 , a signal indicating that the tension is in an extreme state is transmitted from the extreme tension state judgement unit 45 to the control gain alteration instructing unit 46. Further, a control gain alteration instruction is transmitted to the optimum gain setting unit 23, and the integral gains K 11 , K 12 , K 21 , K 22 and the proportional gains F 1 to F 6 are altered to tension compensation gains set in advance. The time point T 4 indicates the time point when the looper angle becomes equal to a value lower than the extreme tension end angle θ end set in advance. Since the extreme tension state judgement unit 45 stops outputting an extreme tension state signal at the time point T 4 , the control gain alteration instructing output from the control gain alteration instructing unit 46 is also stopped. The optimum gain setting unit 23 returns the gains of the integral operation element and the proportional operation element to original values from the tension compensation gain. Here, the tension compensation gain may be determined by alterating, e.g., weight matrices R, Q of the equation (7) to swing the looper to an extreme extent to calculate such a gain to eliminate a change in the tension. In this case, attention should be drawn to the fact that when such a gain is set in an ordinary rolling state, the looper may be frequently lowered to a level below the pass line, or reach the mechanical upper or lower limits, resulting in a damaged working stability.
The operation of the system according to this invention at the time when the tension is in an extreme state will now be described.
The extreme looper angle state judgement unit 51 judges the looper angle to be extreme for a time period from the time when a detection value θ of the looper angle exceeds above an upper limit angle θ max set in advance until it falls below the upper limit angle to output an extreme angle state signal to the looper angle upper and lower limit alteration instructing unit 52. When the looper angle upper and lower alteration instructing unit 52 receives the extreme angle state signal, it alters the target value θ r of the looper angle to the upper limit angle and outputs a control gain alteration instruction to the optimum gain setting unit 23. Thus, the optimum gain setting unit 23 alters the integral gains K 11 , K 12 , K 21 , K 22 of the blocks 9 to 12 and the proportional gains F 1 to F 6 of the blocks 17 to 22 to the upper limit compensation gains, respectively. When the detection value θ of the looper angle shifts from the state where it is above the upper limit θ max to the state where it is less than the upper limit angle θ max , the extreme looper angle judgement unit 45 stops outputting the extreme angle state signal. Thus, the looper angle upper and lower limit alteration instructing unit 52 returns the target value of the looper angle from the upper limit angle θ max to the original value to turn off the control gain alteration instruction which has been outputted to the optimum gain setting unit 23. Accordingly, the optimum gain setting unit 23 returns the integral gains of the blocks 9 to 12 and the proportional gain of the blocks 17 to 22 from the upper limit angle compensation gains to the original values, respectively.
Similarly, the abnormal looper angle state judgement unit 51 judges the looper angle to be abnormal for a time period from the time when a detection value θ of the looper angle falls below the lower limit θ min until it exceeds above the lower limit angle θ min to output an abnormal angle state signal to the looper upper and lower limit alteration instructing unit 52. Thus, the looper angle upper and lower limit alteration instructing unit 52 alters the target value θ r of the looper angle to the lower limit angle θ min and outputs a control gain alteration instruction to the optimum gain setting unit 23. Thus, the optimum gain setting unit 23 alters the integral gains K 11 , K 12 , K 21 , K 22 of the blocks 9 to 12 and the proportional gains F 1 to F 6 of the blocks 17 to 22 to the limit compensation gains for lower limit angle on the basis of the alteration instruction. When a detection value θ of the looper angle shifts from the state where it is less than the lower limit θ min to the state where it is above the lower limit θ min , the extreme looper angle state judgement unit stops outputting the extreme angle state signal. Thus, the looper angle upper and lower limit alteration instructing unit 52 returns the target value of the looper angle from the lower limit angle θ min to the original value to turn off the control gain alteration instruction which has been outputted to the optimum gain setting unit 23. Accordingly, the optimum gain setting unit 23 returns the integral gains of the blocks 9 to 12 and the proportional gains of the blocks 17 to 22 from the limit angle compensation gain to the original values, respectively.
The operation at the time when the looper angle is in an extreme state of the looper control system 100 shown in FIG. 1 will now be described with reference to FIGS. 4A to 4L. FIG. 4A is a graph showing how the target value θ r of the looper angle varies with time where θ aim represents a target angle in the case of conducting an ordinary control, θ max represents an upper limit set in advance, and θ min represents a lower limit angle set in advance. FIG. 4B is a graph showing how the looper angle θ varies with time. FIGS. 4C to 4F are graphs showing how the absolute values of the integral gains K 11 , K 12 , K 21 , K 22 vary with time, respectively. FIGS. 4G to 4L are graphs showing how the absolute values of the proportional gains F 1 to F 6 vary with time. These FlGS. 4A to 4L are plotted with respect to the same abscissa showing lapse of time. The timing T 1 on the abscissa indicates the time point when a material subject to rolling has been chucked into the upstream stand, and the timing T 2 indicates the time point when that material has been chucked into the downstream stand. At the timing T 2 , a tension is produced in the material subject to rolling. At times subsequent thereto, the tension T and the looper angle θ are controlled by the looper control system 100 so that they are in correspondence with values near the target values T r and θ r , respectively. The timing T 3 indicates the time point when the looper angle θ increases suddenly for any reason to exceed above the upper limit angle θ max . At the timing T 3 , the extreme looper angle state judgement unit 51 outputs an extreme angle state signal to the angle upper and lower limit alteration instructing unit 52. Thus, the angle upper and lower limit alteration instructing unit 52 alters the target value θ r of the looper angle from Θ aim to the upper limit θ max and outputs a control gain alteration instruction to the optimum gain setting unit 23. The optimum gain setting unit 23 alters the integral gains K 11 , K 12 , K 21 , K 22 and the proportional gains F 1 to F.sub. 6 to the respective upper limit angle compensation gains. The timing T 4 indicates the time point when the looper angle shifts from the state where it exceeds above the upper limit angle θ max to the state where it falls below the upper limit angle θ max . Since the extreme looper angle state judgement unit 51 stops an output indicative of extreme angle state at the timing T 4 , the looper angle upper and lower limit alteration instructing unit 52 returns the target value θ r of the looper angle from θ max to θ aim and stops the control gain alteration instructing output which has been outputted to the optimum gain setting unit 23. Thus, the optimum gain setting unit 23 returns the integral gains and the proportional gains from the upper limit angle compensation gains for upper limit to the original values, respectively.
FIG. 5 is a block diagram showing a second embodiment according to this invention. In this figure, the same components as those in FIG. 1 are designated by the same symbols or reference numerals, respectively, and their explanation will be omitted.
In FIG. 5, a looper speed control unit (looper ASR) 1A is used. This embodiment differs from the embodiment in FIG. 1 in that the above portion was constituted by the looper current control unit in the embodiment in FIG. 1. The looper speed control unit controls a rotational speed N a of the looper driving motor 2 to drive the looper mechanical system 3. The rotational speed target value for this looper speed control unit is obtained by adding an output from the integrator 14 and an output from the adder 16 at the adder 36 to provide a looper speed target correction quantity N ar to add it to a looper speed target value N aro at the time of start of control at the adder 39.
Since the flows of other signals are completely the same as those in the case of FIG. 1, the detailed explanation is omitted.
Accordingly, when the configuration of the looper control system according to this embodiment is put in order, it is seen that the speed target value correction quantity ΔN ar delivered to the looper speed control unit 1 is essentially provided by adding output values from the respective means shown in the following items (a) to (c).
(a) Means for performing the integral operation by the integral gain K 12 (block 10) and the integrator 14 with respect to a deviation between the actual interstand tension value T and the interstand tension target value T r , and the proportional operation by the proportional gain F 4 (block 20) with respect to a deviation between the actual interstand tension value T and the interstand tension lock on value T o ,
(b) Means for performing the integral operation by the integral gain K 22 (block 12) and the integrator 14 with respect to a deviation between the actual looper operation angle value θ and the looper operation angle target value θ r and the proportional operation by the proportional gain F 5 (block 21) in connection with a deviation between the actual looper operation angle value θ and the looper operation angle lock-on value θ o , and
(c) Means for performing the proportional operation by the proportional gain F 6 (block 22) with respect to the actual looper drive motor rotational speed value N a and the looper drive motor rotational speed lock on value N ao .
The looper speed target value correction quantity ΔN ar thus obtained and the looper speed target value N aro at the time of start of control are added. The added value thus obtained is delivered as a looper current target value to the looper control unit 1A.
On the other hand, the rotational speed target value correction quantity ΔN r of the main motor delivered to the main speed control unit 4 is provided by adding output values from the respective means shown in the following items (d) to (f).
(d) Means for performing the integral operation by the integral gain K 11 (block 9) and the integrator 13 with respect to a deviation between the actual interstand tension value T and the interstand tension target value T r , and the proportional operation by the proportional gain F 1 (block 17) with respect to a deviation between the actual interstand tension value T and the interstand tension lock on value T o ,
(e) Means for performing the integral operation by the integral gain K 12 (block 11) and the integrator 13 with respect to a deviation between the actual looper operation angle value θ and the looper operation angle target value θ r , and the proportional operation by the proportional gain F 2 (block 18) with respect to a deviation between the actual looper operation angle value θ and the looper operation angle lock-on value θ o ,
(f) Means for performing the proportional operation by the proportional gain F 3 (block 19) with respect to the actual looper drive motor rotational speed value N a and the looper drive motor rotational speed lock on value N ao .
The rotational speed target value correction quantity ΔN r of the main motor thus obtained and the rotational speed target value N ro of the main motor at the time of start of control are added. The added value thus obtained is delivered as a rotational speed target value to the main motor speed control unit 5.
Further, in the same manner as in the case of FIG. 1, modifications of the above-mentioned respective integral gains and the proportional gains will be made in accordance with the state where the tension is extreme by the extreme tension state judgement unit 45 and the control gain alteration instructing unit 46; and in accordance with the state where the looper angle is extreme by the extreme looper angle state judgement unit 51 and the looper angle upper and lower limit alteration instructing unit 52.
The operation of the looper control system constructed as described above will now be described.
The looper characteristic model of the continuous rolling mill is represented by the previously described equations (1) and (2) expressed in the form of the linear state equation.
x=A.x+B.u (1)
y=C.x (2)
where x means a time derivative dx/dt. x and y are vectors expressed by the equations (3) and (5), respectively, but only the manipulation vector u is different from the above and is expressed by the following equation (28). Further, A, B and C are constant matrices of 3×3, 3×2 and 2×3, respectively.
x=[ΔT, Δθ, ΔN.sub.a ].sup.T (state vector(3)
u=[ΔN.sub.r, ΔN.sub.ar ].sup.T (manipulated vector)(28)
y=[ΔT, Δθ].sup.T (output vector) (5)
In the above equation, symbol T represents a transposition of vector and symbol Δ represents a deviation from the vicinity of the steady state. Further, the notations employed are as follows:
T: actual interstand tension value,
θ: actual looper operation angle value,
N a : actual looper drive motor rotational speed value,
N r : rotational speed target value of the main motor,
N ar : looper speed target value.
The optimum control theory is applied to this embodiment in exactly the same manner as in the case of FIG. 1, and therefore the previously described equations (6) to (19) are applied.
The correspondences between variables in the equation (19) and FIG. 5 are expressed by the equations (16) and (17) in connection with K, F, respectively, and are expressed by the equations (22), (23), (24) and (15) in connection with Y, Y r , X and X o , respectively. The above-mentioned correspondence are expressed, in connection with U and U o , as follows:
U=[N.sub.ro +ΔN.sub.r, N.sub.aro +N.sub.ar ].sup.T (29)
U.sub.o =[N.sub.ro, N.sub.aro ].sup.T (30)
Accordingly, also in the embodiment shown in FIG. 5, optimum control can be made by the feedback loop configuration using only three kinds of signals.
It is to be noted that the gain alteration in response to the extreme tension and/or the extreme looper angle can be adopted arbitrarily. | There is disclosed a looper control system for a continuous rolling mill comprising: a section for performing the integral operation of respective deviations between measured values and target values with respect to the tension and the looper angle, and the proportional operation of respective deviations between the tension, the looper operation angle, and the rotational speed of the looper motor at the time of start of the control and those at the present time to synthesize values thus obtained to deliver them to the looper current control unit or the looper control unit, a section for performing the integral operation and the proportional operation similar to the above to synthesize the values thus obtained to deliver them to the main motor speed control unit; and an optimum gain setting unit for correcting respective proportional gains in dependency upon the speed of the main motor. The system may additionally have a section for altering the optimum gain by the fact that the tension is extreme and/or the looper angle is extreme. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a conveying system for removing old roofing material from a roof preparatory to replacement with new roofing material.
2. Prior Art
Roofs of buildings are made with a variety of materials--tar paper, shingles, asphaltic tiles, etc. Because the roof surface is directly exposed to the weather, these coverings degrade so that after a period of time--generally twelve to twenty years, the roof covering must be replaced by new roofing material. The first step in replacing the roof is to tear off and remove the old weathered material ("tearoff"). Present practice is to tear off a portion of the old covering, carry it to the side of the building and drop it off onto the ground below. Use of conventional devices for carrying tearoff to the edge of the roof such as wheel barrows are not practical because of the pitch of the roof which renders the use of such devices awkward and dangerous. Furthermore, because material must be removed from large areas any, apparatus for conveying old material to the edge of the roof must be capable of being moved easily over a wide area, must be strong enough to support heavy loads, and must be constructed so that it can be adapted readily to various roof pitches.
There are many devices that have been built to convey a variety of materials. These devices include conveyor belts such as are used to convey goods and materials in factories and carts on tracks such as are used to haul ore from mines. However these conveying devices are built for use on flat surfaces, such as the floor of a factory (in the case of conveyor belts) or they have been built with permanent scaffolding and trestles (in cases such as cars on tracks used for hauling ore out of mines). Tracks of this type and associated supports have not been constructed so that they could be temporarily yet securely mounted at an arbitrary angle on a roof having a pitch occurring in a wide range.
SUMMARY OF THE INVENTION
It is an objective of this invention to provide means for conveying tearoff over large distances on sloping rooves so that it can be dumped over the side of the building.
It is a further objective that the means for conveying tearoff be easily assembled and dismantled--preferrably light enough for one man.
Still another objective is that the means for conveying may be adaptable to various slopes of the roof.
Yet another objective is that the conveying means can be assembled and operated on any desired angle with the edge of the roof and assembled over several sections of roof in which each section slopes differently or in a different direction from the other sections of the roof.
Briefly, the means for conveying is a cart which runs on a track. The cart is a flat rectangular platform with a wheel attached to the underside of the platform at each of the four corners. The wheels of the cart run in two troughs formed by metal angles held permanently parallel to one another by connecting bars. The entire track is an assembly of short sections of parallel angles (preferably metal) attached end to end. Alternatively, the track could be formed from channel however angles are preferred because an inexpensive method of joining sections is provided, angle is cheaper than channel and rubbing of the sides of the wheel with possible resultant binding as experienced with channel is avoided.
The track is supported on H frames spaced at appropriate distances from one another. Each H frame has a horizontal center bar to which the track is attached by U bolts which pass through the connecting bars so that the track may be positioned by rotation with respect to the center bar of the H-frame. At each end of the center bar a vertical leg is attached at a desired distance from a support end of the leg which rests on the roof. Each leg is a round bar (or pipe) which may be positioned by sliding within a short section of pipe which is secured at its center perpendicular to each end of the center bar. The distance from the support end of each leg to the center bar may be fixed by positioning the leg in the support sleeve and then inserting a pin into one of the holes lying in a row in the leg to fix the position of the leg relative to the center of the bar. Thus the supporting length of each leg of all the H frames is selected so that the track lies straight on the desired slant regardless of the pitch or variation of pitch of the roof and regardless of the angle which the track makes with the edge of the roof.
The supporting end of the each leg rests on a shoe. The shoe is a flat plate with ears on each side so that the shoe may be hinged to the leg by a pin passing through a hole near the support end of the leg and a hole in each ear of the shoe.
By positioning the shoe plate about its hinging pin and rotating the leg in its support sleeve, the shoe plate may be positioned to lie flat on the roof so as to provide a stable resting surface for the support end of each leg. A nail through a small securing hole in the plate and on into the roof prevents sliding of the shoe plate on the sloping surface.
On any of the legs, a brace may be positioned such that a support end of the brace with shoe plate hinged as described above is attached to the roof and the bracing end of the brace is attached to the leg by a universal joint. The universal joint is a bracing sleeve which slides for positioning on the leg and is then secured in position with a pin through the leg but not through the bracing sleeve. A short threaded stem is welded to the sleeve and perpendicular to the sleeve. A U-strap is bolted to the stem passing through a hole in the center of the U strap. A hinging pin, passing through a hole in each leg of the U-strap also passes through a hole through the bracing end. The brace is thereby provided with three axes of rotation--the first concentric with the bracing sleeve, the second perpendicular to the bracing sleeve and coincident with the hinging pin, the third coincident with the stem so that the shoe plate of the brace may be nailed flat to a convenient position on the roof regardless of pitch, proximity to the edge of the roof, etc. and maintain the H frame in its vertical position.
In order to control descent of the loaded cart and to draw the empty cart back to the upper end of the track, one end of a cable is fastened to an end of the cart and the other end is fastened to a winch positioned at the upper end of the track. The winch is a drum supported on its axle so that it can be turned by a crank rigidly attached to the axle of the drum.
The axle of the drum pases through aligned axle holes in the end segments of a yoke. The center segment of the yoke which is attached to the end segments has a short sled angle perpendicularly attached to each end of the center segment and a sled angle is positioned in the trough of each track angle. Therefore the winch may be located at any of the sites of the connecting bars and bolted to any of the connecting bars using holes in the middle segment.
A circular ratchet is also attached to the axle. A ratchet key is pivotally attached on the yoke so that it may be engaged or disengaged with the ratchet and used to lock the winch so that by turning the crank. An operator may place the cart at any position along the track and then secure the cart in position with the ratchet key.
A brake is also provided in order to prevent the cart from rolling independent of the winch such as when it is desired to move the winch to another location on the track. The brake is a short sleeve (pipe) with a longitudinal slot in its side aligned with a hole in the platform and attached perpendicular to the platform of the cart. A braking bar with a handle on one end and a stem on its side is oriented so that the bar may slide in the sleeve so that a second end of the braking bar extends through the hole and engages with a connecting bar thereby preventing the cart from rolling. The bar may be withdrawn and turned so that the stem holds the bar in the retracted position.
A bar across the track at the lower end prevents the cart from running off the end of the track.
Because of the sectional construction of the track and the light weight of all components including the sections of track and the cart, the tearoff conveyor may be easily transported to a jobsite, hoisted to roof top and assembled with appropriate allowance for the slope of the roof. When all of the tearoff has been removed from one area, the tearoff conveyor may be conveniently moved to other areas of the roof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the tearoff conveyor mounted on a roof.
FIG. 2 shows details of the H frames and braces that support the track.
FIG. 3 shows details of the shoe attached to the supporting end of each leg of the H frame and each brace.
FIG. 4 shows details of a track section.
FIG. 5 shows details of the brake mounted on the cart and the winch for controlling motion of the cart.
DETAILED DESCRIPTION OF THE INVENTION
Turning now to a more detailed discussion of the figures, there is shown in FIG. 1 a tearoff conveyor 10 mounted on a roof 12 in accordance with the invention. There is shown tearoff 14 piled on a cart 16 which rides on a track 18. The track is supported on a number of H frames--20, 22, 24, 26. Because the track 18 is not set perpendicular to the edge 28 of the roof, the left side of the track 18L is closer to the roof than the right side 18R so that the axes of the front and rear wheels 29 are horizontal thereby avoiding the tipping of cart 16 off the track. In addition, the distance of the track 18 to the roof 12 is larger at the destination end 30 of the track in order to provide better control of the loaded cart 16 in its descent i.e., the track 18 is not sloped as steeply as the roof 12.
The positioning of the track 18 relative to the roof 12 is accomplished by adjustments on the H frames 20, 22, 24, and 26 as will be discussed with reference to FIG. 2 which shows components of the H frame and FIG. 3 which shows the foot 44 of the H frame and brace. Each H frame includes a horizontal center bar 32 with a supporting sleeve i.e. a short length of vertical pipe, 34 secured at each end. A leg 36 is positioned by sliding in each supporting sleeve 34 and secured by securing pin 38 inserted into positioning hole 40. Hole 40 is selected from the row of positioning holes 41 in legs 36 in accordance with the desired distance from the support ends 42 to the central bar 32 so that the center bar 32 is horizontal regardless of the slope of the roof. Support ends 42 rest on shoes 44. As shown in FIG. 3, each shoe 44 is a plate 46 with ears 48 so that each shoe 44 as shown in FIG. 3 is hinged about each support end 42 by a hinging pin 49. Consequently, by rotating the leg 36 in its supporting sleeve 34 and rotating each shoe 44 about its hinging pin 49, the shoe 44 may lie flat on the roof 12 regardless of the slant of the roof and secured with a nail 50 in a securing hole 52 in the plate 46.
In order that each H frame may be secure in the erect position, a brace 56 shown in FIG. 2 has a resting end 60 attached to the roof with another shoe 44 and a bracing end 58 attached to the leg 36. Attachment to the leg 36 is by means of a universal joint 62 which permits the shoe 44 to lie flat on the roof so that it may be fastened with a nail 51 thereby providing adequate support for the leg 36.
The universal joint 62 has a bracing sleeve 64 positioned by sliding on leg 36 and securing by a securing pin 66 in the appropriate positioning hole in row of holes 41. As shown in FIG. 2, the pin 41 does not pass through the bracing but under the bracing sleeve. A threaded stud 68 is secured to the bracing sleeve 64 perpendicular to the sleeve 64. A U strap 70 with a center leg 72 and two side legs 74 is bolted to the stud 68 which passes through a pivot hole 76. Aligned hinging holes 78 in the side legs provide hinged attachment to the bracing end 58 by a hinging pin 80 through the hinging holes 78 and a second hinging hole 82 near the bracing end 58. Thus when the leg 36 is positioned vertically on the roof 12, the U strap 70 is positioned by rotation and bolted on the threaded stud 68 and the bracing end 58 is positioned by rotation about the U strap 70 and the shoe 44 is positioned by rotation about the resting end 60 then the shoe 44 will lie flat on the roof so that it may be fastened to the roof by a nail 86 passing through a securing hole 84 in the shoe plate 46 regardless of the orientation of the slant of the roof.
Referring to FIG. 4, there is shown a section of track 86 which, with other sections laid end to end, makes up the entire length of track. Each section 86 has two track angles 88 formed by two strips 90 joined along a common edge 92 to form a trough 94 oriented to face the cart whose wheels 96 are confined to roll in the trough 94. The track lengths 88 are secured in their orientation and parallel relation to one another by connecting bars 98. each end of each connecting bar 98 is shown secured to one of the angles 88.
Still referring to FIG. 4, the means for securing the track section 86 to the center bars 32 are U bolts 100, each of which encloses a center bar 32 and having two threaded ends 102 which pass through fastening holes 104 in the connecting bar 98 and is secured by nuts.
The means for joining the track section to its neighbor is a short length of angle 108 positioned so that the end of a track angle 110 and the abutting end of the neighboring track angle 112 both lie in the trough of the short length of angle 108 and are secured by bolts.
Referring to FIG. 1, because the loading location 31 is higher than the destination location 30 gravity is used to pass the cart from the loading end 31 to the destination end 30 where the cart 16 is unloaded. Then it must be hauled back to the loading position 31. In order to control the descent of the cart and then to haul it back to the loading location, a braking and pulling means for the cart is provided wich will now be discussed with refrence to FIG. 5.
As shown in FIG. 5, the cart 16 is a platform 116 with wheels 118 attached to the underside 120. A braking bar 122 slides in a braking sleeve 124 attached perpendicularly to the topside 125 of the cart so that the braking bar 122 may be pushed through the brake sleeve 124 and engage a connecting bar 98 of the track section 86 so as to prevent descent of the cart 16. The braking sleeve 124 has a slot 128 and the braking bar 122 with handle 130 has a key 132 which slides in the slot 128 so that when the braking bar is not in use, it may be partially withdrawn from the sleeve and fixed by turning the handle 130.
In order to control the speed of descent of the cart and to pull the cart toward the loading location, one end of a cable 134 is attached to the cart 16 shown cutaway while the other end of the cable is attached to a winch 136 located toward the loading end of the track. The winch 136 is a drum 138 and ratchet wheel 140 both mounted on an axle 142 to which is attached a winch handle 144 for turning the drum 138. The axle 142 is supported by a yoke 146 being a U shaped strap with aligned axle holes 148 in each of the two end segments 152 and a center segment 154. A short sled angle 156 is attached perpendicularly to each end of the center segment 154 so that it may be positioned in the trough of the track angle 88. The winch 136 is thereby positioned over the track and may be secured by winch bolts 15 through the center segment 154 and any of the connecting bars 98 depending on where it is desired to locate the winch 136.
A ratchet key 153 is attached to the yoke and pivots so that the drum 138 may be locked by engagement of the ratchet key 153 and ratchet wheel 140.
Thus the operator can locate the winch in the middle of the track which becomes his location for controlling the cart, then he may apply the brake and slide the winch to a higher location.
In actual practice, it has been found that the tearoff conveyor, operated in accordance with this invention saves two man days in stripping tearoff from a typical roof of 3200 square feet. Savings are considerably increased with larger rooves and a reduction of required man hours by 50% is typical. | A conveyor for carrying roofing debris to the edge of a roof which may be easily assembled on a roof with any pitch, moved from area to area as the work of tearing off old roofing material progresses and disassembled. A track, an assembly of track sections, is supported on a number of H frames which are braced and adjustable to accommodate any slant to the roof, by legs slidably adjustable in sleeved attachments to horizontal supporting bars. A winch, attached toward the loading end of the track, with cable attached to the winch and cart, controls descent of the cart down the track and may also be used to draw the cart back toward the loading end. | 4 |
This application claims priority of U.S. Provisional Application Ser. No. 60/843,360, filed Sep. 8, 2006, the disclosure of which is incorporated herein by reference.
The U.S. Government has a paid-up license in this invention and the right in limited circumstances to require the patent owner to license others on reasonable terms as provided for by the terms of Grant No. DAAD19-02-D-0002, awarded by the Army Research Office.
BACKGROUND OF THE INVENTION
Over the past decade, the technique of polymer thin film deposition known as “Layer-by-Layer” has proven its versatility in creating very uniform films of precisely controllable thickness, even on the nanometer length scale. This process is commonly used to assemble films of oppositely charged polyelectrolytes electrostatically, but other functionalities such as hydrogen bonding can be the driving force for film assembly. Typically, this deposition process involves the submersion of a substrate having an inherent surface charge into a series of liquid solutions, or baths. Exposure to the first polyion bath, which has charge opposite that of the substrate, results in charged species near the substrate surface adsorbing quickly, establishing a concentration gradient, and drawing more polyelectrolyte from the bulk solution to the surface. Further adsorption occurs until a sufficient layer has developed to mask the underlying charge and reverse the net charge of the substrate surface. In order for mass transfer and adsorption to occur, this exposure time is typically on the order of minutes. The substrate is then removed from the first polyion bath, and is then exposed to a series of water rinse baths to remove any physically entangled or loosely bound polyelectrolyte. Following these rinse baths, the substrate is then exposed to a second polyion bath, which has charge opposite that of the first polyion bath. Once again adsorption occurs, since the surface charge of the substrate is opposite that of the second bath. Continued exposure to the second polyion bath then results in a reversal of the surface charge of the substrate. A subsequent rinsing is then performed to complete the cycle. This sequence of steps is said to build up one ‘layer pair’ of deposition and can be repeated as desired to add further layer pairs to the substrate.
While this procedure as described is able to produce extremely uniform films as thin as one nanometer per layer pair, it is not uncommon that an individual layer pair may require upwards of thirty minutes to deposit. For a twenty-five layer pair film, the deposition process may then require more than twelve hours to complete. As a result, the Layer-by-Layer (LbL) dipping technique is typically carried out by a computer controlled slide-stainer to eliminate the need for human interaction. The choice of polyelectrolyte solvent is thereby typically limited to those solvents with relatively low vapor pressure, such as water, to avoid evaporation and species concentration during extended dipping periods.
Furthermore, since LbL is typically based on an electrostatic phenomenon, the degree of ionization of each polyelectrolyte in solution has a profound effect on the strength of interaction felt with the surface, and thus, the thickness of the adsorbed layer. For weak polyelectrolytes, pH has been most commonly used to vary charge density along the polymer chain and thus control layer thickness. For strong polyelectrolytes, charge shielding by varying ionic strength accomplishes the same function. In the case of an absorbent substrate, such as fabric, the cyclic nature of the dipping process can lead to a degree of carryover from the rinse baths to the subsequent polyelectrolyte solutions. This carryover can induce an observable change in the pH of the polyelectrolyte solutions, which may be unacceptable in certain cases. Additionally, long sample preparation times can allow the pH of the polyelectrolyte solution to drift, as evaporation and concentration of the solution occurs.
In an effort to eliminate rinse water contamination, robotic modifications have been made to dipping systems. One such modification involves spraying the sample with water, which immediately drains away. Since the contaminated water drains away, and is not left in the rinse bath, the likelihood of contamination and swelling of the film between alternating depositions is lessened.
As stated above, the traditional Layer by Layer process is very time consuming. In the dipping method, polymer chains must diffuse to the charged surface once a depletion layer is developed by adsorption of nearby molecules. Thus, there exists a diffusion time scale, which is inversely proportional to the diffusivity of the polyelectrolyte through the solvent, limiting the rate of deposition.
This characteristic time increases with decreasing diffusivity values, commonly seen with larger molecular weight molecules.
A less time consuming method of performing layer by layer deposition is needed. However, such a method cannot reduce the quality or uniformity of the layers that are deposited, since these factors are critical. Additionally, methods performing layer by layer deposition on substrates having large surface areas or three dimensions are also required.
SUMMARY OF THE INVENTION
The problems of the prior art have been overcome by the present invention, which comprises an automated apparatus capable of spray depositing polyelectrolytes layer by layer (LbL) with minimal or no human interaction. In certain embodiments, the apparatus sprays atomized polyelectrolytes onto a vertically oriented substrate. To counteract the effects of irregular spray patterns, the substrate is preferably slowly rotated about a central axis. In certain embodiments, the apparatus also includes a forced pathway for the droplets, such as a pathway created by using a vacuum. In this way, a thicker or three-dimensional substrate can be coated. In certain embodiments, the modular apparatus is designed so as to be scalable. In other words, through the use of multiple instantiations of the apparatus, a large or irregularly shaped substrate can be coated. Rolls of textile can therefore be coated using the apparatus. Additionally, the present invention includes a method to uniformly coat a substrate, such as a hydrophobic textile material, using aqueous solutions of polyelectrolytes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a first embodiment of the apparatus of the present invention;
FIG. 2 illustrates a second embodiment of the apparatus of the present invention used for roll-to-roll processing;
FIG. 3 illustrates a third embodiment of the apparatus of the present invention preferably used for three dimensional substrates;
FIG. 4 illustrates a fourth embodiment of the apparatus of the present invention;
FIG. 5 illustrates a graph showing the growth trend for a (SPS/PDAC) n system using both dipped and sprayed LbL deposition;
FIG. 6 illustrates a graph showing the growth trend for a (PAMAM/PAA) n system using both dipped and sprayed LbL deposition;
FIG. 7 illustrates a graph showing the growth trend for a (PEO/PAA) n system using sprayed LbL deposition;
FIG. 8 illustrates a graph showing the growth trend for a (TiO2/PDAC) system using sprayed LbL deposition; and
FIG. 9 illustrates the diffraction spectrum for the substrate of FIG. 8 .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 represents one embodiment of the present invention. An automated spray system 10 is depicted which can be used to coat substrate 20 using a layer by layer methodology. In the preferred embodiment, at least three atomizing nozzles 30 , 34 , 38 are used to spray the substrate 20 . Each of these nozzles is in communication with a corresponding reservoir 40 , 44 , 48 . These reservoirs are used to hold the materials that are conventionally held in baths for traditional LbL dipping processes. Thus, polyelectrolytes of opposing charge are held in two of the reservoirs 40 , 48 , while the remaining reservoir is used to hold water or other suitable fluid for the rinse cycle. Those skilled in the art will appreciate that although reservoirs 40 , 44 and 48 are shown, other embodiments can be used that provide each nozzle in communication with a suitable supply of appropriate fluid. Preferably, the rinse fluid used is deionized water (DI). The contents of these reservoirs are pressurized, such as by using gas, preferably inert gas, such as nitrogen, argon or other suitable gases not deleterious to the fluids used or to the apparatus. The pressure at which the gas is maintained affects the droplet size and flow rate and preferably is in the range of from about 20 to about 120 psi, most preferably about 50-70 psi. The output from each of these pressurized reservoirs feeds one side of a switching device, preferably a solenoid controlled valve. Thus, when the solenoid is charged, pressurized material flows from the corresponding reservoir through the valve and through the atomizing nozzle. Conversely, when the solenoid is not charged, there is no fluid flow.
Each of these solenoids is preferably controlled by a microcontroller (not shown). A single microcontroller can be used to control each device, or one or more devices can have a dedicated microcontroller. The microcontroller is adapted to generate and output signals used to operate the solenoids. The microcontroller is preferably programmed to activate and deactivate the three solenoids in a fixed sequence, with a specific time duration for each. For example, a cycle can comprise a pulse of fixed duration that charges the polycationic solution solenoid 50 , followed by a pulse of fixed duration for enabling the rinse fluid solenoid 54 , followed by a pulse of fixed duration for enabling the polyanionic solution solenoid 58 , followed by a second pulse of fixed duration for the rinse fluid solenoid 54 . Preferably, the microcontroller is programmed in small time intervals, such as 10 milliseconds, so as to produce pulses ranging in duration from 10 milliseconds to many seconds or minutes. Similarly, the duration between the deactivation of one solenoid to the activation of the next solenoid is also programmable, typically within the same ranges as stated above. While the preferred embodiment enables one nozzle at a time, the invention is not so limited. Through the use of a microcontroller, the sequencing of the solenoids is completely programmable. For example, other scenarios, such as spraying the polyanionic and polycationic material simultaneously by concurrently enabling the corresponding solenoids, are also possible. In the preferred embodiment, these time durations are predetermined and programmed within the microcontroller. The duration of the spraying is sufficiently long so as to create the required layer thickness, such as 3 seconds. Similarly, the duration of the rinse is sufficiently long so as to adequately remove all unattached material, such as 10 seconds.
In the preferred embodiment, the substrate 20 is vertically oriented, so as to allow the sprayed material to naturally drain from it, due to gravitational force. However, the use of multiple nozzles has the potential to create irregular spray patterns. Therefore, to counteract this effect of possible irregularities in the nozzle spray pattern, the substrate 20 is preferably rotated about a horizontal axis 75 , wherein the axis is preferably perpendicular to the nozzle. This rotation is performed by any suitable means, such as a gear motor 70 . The rotational speed of the motor is preferably very low, so as not to introduce significant centrifugal forces onto the substrate. Rotational speeds of less than 20 revolutions per minute are preferred, with speeds of 10 RPM most preferred. As stated above, the purpose of the rotation is to overcome any spray pattern irregularities over the entire surface area of the substrate. Thus, the time duration of the spray, the diameter of the spray pattern and the diameter of the substrate all affect the recommended RPM. In other words, for larger diameter substrates (assuming a constant spray pattern diameter), either the spray duration or the RPM may be increased to insure uniform coating. Alternatively, the substrate may remain stationary, while the nozzles are moved so as to overcome any irregularity of spray pattern. Finally, both the substrate and the nozzle can be moving; the preferred embodiment only requires that there be relative motion between the substrate and the nozzles.
Finally, to avoid contamination, all plumbing, including valve bodies, and hoses 80 , 84 , 88 , 90 is preferably constructed of poly(propylene), although other materials not deleterious to the process such as stainless steel, polyurethane, Delrin, PVC, polypropylene are also suitable.
In operation, the gas supply 60 is enabled, thereby pressurizing all three reservoirs. All of the solenoids 50 , 54 , 58 begin the process in the closed position, so that no material is being spraying toward the substrate 20 . Following activation, the microcontroller begins to perform the programmed cycle. A signal is asserted by the microcontroller which causes cationic solenoid 50 to open. This allows material from the polycationic reservoir 40 to pass through the solenoid and to the corresponding atomizing nozzle 30 . Atomizing nozzles are well known in the art and will not be described in great detail. A suitable nozzle is the M series of nozzles, commercially available from Hago Nozzles. The polycationic material is then sprayed onto the slowly rotating substrate. The duration of time that polycationic solution is sprayed onto the substrate can be predetermined and programmable, and depends on the material and substrate used. As stated earlier, the rotation of gear motor 70 causes the substrate to rotate slowly, allowing the material to more evenly be distributed on the substrate. After the predetermined time interval, the microcontroller deasserts the signal to the solenoid 50 , thereby causing the flow of cationic material to stop. After a second predetermined time has elapsed, the microcontroller asserts the signal enabling the rinse fluid solenoid 54 . This enables rinse fluid from the rinse fluid reservoir 44 to pass through to atomizing nozzle 34 . Rinse fluid is then sprayed onto the rotating substrate to remove residue. The duration of the rinse cycle can be predetermined and is programmable and is an implementation choice. Following the lapse of another predetermined amount of time, the microcontroller asserts a signal enabling the polyanionic solenoid 58 . This enables material from the polyanionic reservoir 48 to pass through to atomizing nozzle 38 and onto rotating substrate 20 . After the polyanionic material has been sprayed for the predetermined period, rinse fluid solenoid 54 is again energized, allowing a second rinse fluid rinse to occur. This completes one cycle of the LbL process.
In one embodiment, the polycation solutions was sprayed for 3 seconds each, followed by a 17 second period in which the substrate was allowed to drain. The rinse fluid was then sprayed for 10 seconds, and allowed to drain for 10 additional seconds. The polyanion solution was then sprayed for 3 seconds, followed by a 17 second draining period. It should be noted that although this example began with polycationic material, the invention is not so limited. The choice of which solution begins the cycle is based on the original substrate surface charge. The completion of one polyanionic spray, one polycationic spray and two rinse sprays constitutes a complete cycle.
The distance between the output of the atomizing nozzles 30 , 34 , 38 and the substrate may be variable. In other words, it may be beneficial, based on the size and shape of the substrate and the ionic materials to be sprayed, to vary the distance between the nozzle and the substrate. In one embodiment, the atomizing nozzles are mounted on a slidable frame, so that their position in the horizontal direction can be modified. In a second embodiment, the gear motor 70 is mounted on a slidable frame so as to vary its position. The use of frames helps to maintain the relative alignment in the other two dimensions, while the distance is varied. Although not limited by any particular distance, distances of less than 10 inches are preferred.
Several modifications are possible to the preferred embodiment shown in FIG. 1 . For example, rather than 3 separate nozzles, a single nozzle may be used. In such an embodiment, hoses 80 , 84 , 88 all converge into a single nozzle or other suitable means is used to provide fluid communication between nozzle and the sources of polyions and rinse fluid. This eliminates possible deviation caused by differences in nozzle spray pattern, or the position of the nozzle.
Although air-assisted atomizing nozzles are described with respect to FIG. 1 , the invention is not so limited. Any device which can be used to atomize the material is suitable. For example, ultrasonic-assisted atomization, ultrasonic-assisted atomization, and piezoelectric-assisted atomization are all known in the art and within scope of the present invention.
The modularity of the present invention readily allows for scalability. For example, for a sufficiently large substrate, two or more instantiations of the apparatus of FIG. 1 can be used. Preferably, a single microcontroller can be used to control the device. For example, a second set of atomizing nozzles can be added and located above, below or adjacent to the existing set, thereby allowing a much larger spraying area.
Alternatively, multiple instantiations of the apparatus can be arranged to readily spray large bolts of material in a roll-to-roll process. FIG. 2 shows one such embodiment. The material used can be of various types, including but not limited to cotton textiles, nylon, polyester, and heavy cotton canvas. In this configuration, material 110 is fed through roller 120 downwards toward roller 130 . Positioned between roller 120 and roller 130 is a plurality of nozzles 140 , preferably arranged in a straight row. These nozzles 140 are adapted to spray polycationic material. The duration of time that the material 110 is subjected to the spray is determined by the speed at which the rollers move the material 110 past the nozzles 140 . In one embodiment, roller 130 is positioned within a bath (not shown) that contains rinse fluid. In an alternate embodiment, a second set of nozzles can be used to spray rinse fluid onto the material 110 . After the material exits the rinse bath, it travels upward toward roller 150 . Positioned between roller 130 and roller 150 is a second set of nozzles 160 , adapted to spray polyanionic material onto the material 110 . Again, the duration of time that the material 110 is subjected to the spray is determined by the speed at which the rollers move the material 110 past the nozzles 160 . The material then passes over roller 150 . Typically, more than one layer is applied. In one embodiment, the configuration of rollers and nozzles shown is replicated multiple times to allow the material to be exposed to the desired number of cycles. In another embodiment, the material is configured as a continuous loop, whereby the material is passed through the configured nozzles and rollers multiple times. Finally, it should be noted that the scalability of the nozzles allows a variety of configurations to be used for performing the spraying of roll-to-roll materials. While the description above described one such embodiment, it should be noted that other configurations of the nozzles and rinse baths are also possible and are within the skill in the art. Therefore, the present invention is not limited to the embodiment shown in FIG. 2 . Also, although the preferred embodiment sprays polycationic fluid first, followed by a rinse fluid bath, and followed by a polyanionic spray, the invention is not so limited. As stated above the order of operations can be varied, and the polycationic and polyanionic sprays can also be applied simultaneously, if desired.
While FIG. 2 illustrates the use of multiple instantiations of the apparatus to spray a larger two-dimensional area, the invention is not so limited. FIG. 3 shows that the multiple instantiations of the apparatus can be placed in other orientations, such as perpendicular to one another, so as to enable the spraying of a three dimensional substrate 200 . The substrate is positioned between the nozzles 210 , and may be held in position of a wire, a guide rail, string or other suitable means. The exact positioning of the nozzles 210 is an implementation design choice. In one embodiment, a sufficient number of nozzles 210 are utilized so as to insure that the entire surface of the substrate 200 can be covered. The nozzles are then positioned so as to achieve this objective. In this case, the substrate may optionally be rotated. However, since the nozzles are able to spray the entire surface of the substrate 200 , rotation of the substrate is not required. In a second embodiment, the substrate can be rotated so as to insure that spraying of the entire surface area of the substrate is achieved. This may be necessary due to the shape of the substrate, or alternatively, the number and position of the nozzles may be such that complete coverage of the surface area of the substrate is not achieved without rotation. This embodiment offers the advantage of fewer nozzles, but requires relative motion between the substrate 200 and nozzles 210 . In a third embodiment, the substrate 200 is held stationary, while the nozzles 210 are moved about the substrate 200 so as to spray the entire substrate. The nozzles may be positioned on rails, or other suitable means to perform this required movement. It should be noted that FIG. 3 shows 5 sets of nozzles, positioned above the substrate, below the substrate and at 120° angles about the center of the substrate in the horizontal plane. This arrangement is not required by the present invention, and either fewer or a greater number of nozzles can be used. In fact, a single set of nozzles can be utilized if the nozzles (or substrate) are moved so as to allow the nozzle to spray the entire surface area of the substrate.
FIG. 4 illustrates another embodiment of the present invention, where a porous substrate 220 , such as a filter, is being sprayed. To insure that the sprayed material penetrates the entire substrate 220 , external means are used to force the sprayed material to pass through the substrate material. In the preferred embodiment, a vacuum is created behind the substrate 220 , so as to force the sprayed material to pass through the substrate. This vacuum can be created using a variety of methods, which are within the skill in the art. In one embodiment, a vacuum pump is used (not shown). Residual sprayed material that passes through vacuum hose 230 is deposited in a suitable storage container, such as a knockout pot 240 . The addition of the vacuum allows thorough penetration of the sprayed material. The vacuum draws the solution through the substrate, such as a filter mesh, conformally coating the interstitial passages of the mesh with alternatively charged species. Alternatively, rather than “pulling” the sprayed material through the porous substrate 220 , it can be “pushed”. In one embodiment, the gas is pressurized at a higher pressure, so as to force the sprayed material to exit the nozzle at an increased velocity. In another embodiment, several sets of nozzles are used, each set at a different distance from the substrate. Possible applications of this technology include passivation of a stainless steel filter mesh toward electrochemical degradation or for use as a porous catalyst support, or reactive functionalization of an air filter to bind or react specific noxious vapors. Thus, this application method is not limited to the 2-dimensional surface of a thin film, but can thoroughly functionalize the vast surface area of a filter while maintaining the rapid, uniform deposition shown by the previous Spray-LbL technique.
Sprayed deposition presents several advantages over traditional dipped deposition. It allows for considerable decrease in process time. As stated earlier, dipped depositions of 25 or more layers can take in excess of 12 hours. In contrast, the apparatus of the present invention can typically produce 25 layers in less than 30 minutes; an improvement of 2500%. Furthermore, atomization of the solution immediately prior to contact with the substrate allows for uniform coating of extremely hydrophobic surfaces, even using aqueous solutions of charged species. This apparatus can be used to spray various materials, including but not limited to traditional weak and strong polyelectrolytes, hydrogen bonded films, dendrimers or hyperbranched compounds, and colloidal metal oxide nanoparticles such as titanium dioxide, aluminum dioxide and cerium dioxide. Furthermore, the present apparatus can be used to coat various substrates, including but not limited to silicon, flexible plastic sheeting, DuPont® Tyvek®, cotton textile, and glass, such as windshields and headlight diffusers.
To demonstrate the effectiveness of the present apparatus, a number of test were performed.
In one test, two pairs of polyelectrolytes were chosen including a pair of strong polyelectrolytes, poly(sodium 4-styrene-sulfonate) (SPS) and poly(dimethyldiallylammonium chloride) (PDAC), as well as a pair of weak polyelectrolytes, poly(amidoamine) (PAMAM) and poly(acrylic acid) (PAA). PAMAM was specifically selected to test the capabilities of spraying a dendritic molecule as well.
Poly(sodium 4-styrene sulfonate) (SPS) of molecular weight 1,000,000, poly(dimethyldiallylammonium chloride) (PDAC) molecular weight 100,000, and sodium chloride were purchased from Aldrich. Poly(ethylene imine) (LPEI) molecular weight 25,000, poly(acrylic acid) (PAA) molecular weight 20,000, and polyethylene oxide (PEO) molecular weight 100,000 were purchased from Polysciences. Poly(amido amine) dendrimer (PAMAM) generation 4, NH 2 surface, 22 wt % in methanol, was purchased from Dendritech. All chemicals were used as received. Polymer solutions were made using DI water at a concentration of 20 mmol with respect to the repeat unit. Solutions were adjusted to the required pH using HCl or NaOH. The ionic strength of the PDAC and SPS solutions was 0.1 mol NaCl. The hydrogen bonded nature of the PEO/PAA films required careful attention to the pH of both solutions which must not vary more than 0.05 from the desired value. Spray-LbL tests were conducted on three and four inch diameter silicon wafers (Silicon Quest International), while dipped LbL tests were conducted on similar wafers which had been broken into 1 cm by 5 cm pieces. All silicon was cleaned with methanol and Milli-Q water, followed by a five minute oxygen plasma etch (Harrick PCD 32G) to clean and hydroxylate the surface. Four inch diameter Tyvek swatches were cut from unused laboratory coats (VWR) and were used as received.
The growth trend of (SPS/PDAC) n films constructed by dipping as well as by spraying can be seen in FIG. 5 .
Dipped film assembly was automated with a Carl Zeiss HMS DS-50 slide stainer. The silicon substrates were first exposed to the polycation solution for 10 minutes followed by three rinse steps in Milli-Q water for a total of 2 minutes. For the PAMAM/PAA and LPEI/PAA depositions, the Milli-Q water was titrated to pH 4.0 using hydrochloric acid, otherwise the Milli-Q water was used at its default pH. The substrate was then exposed to the corresponding polyanion solution and rinsed similarly. The cycle was repeated for the required number of layer pairs requiring approximately 11.5 hours to complete a 25 layer pair film. Sprayed films were deposited using identical solutions and rinse pH values. All solutions were delivered by ultra high purity Argon (AirGas) regulated to 50 psi. The polycation was sprayed for 3 seconds and allowed to drain for 17 sec. before spraying with water for 10 sec. After a 10 second draining period the polyanion was sprayed and rinsed similarly. The cycle was then repeated for the desired number of layer pairs resulting in a 33 minute process to deposit a 25 layer pair film.
One important consideration was the initial period of film growth, such as during the first 5-10 layer pairs. It is common in solution based LbL dipped depositions to observe an initial non-linear growth regime, which typically lasts through the first three to five layer pairs. After this point, a steady-state, linear growth phase is typically achieved. This initial regime is generally explained by roughness or uneven charge distribution of the substrate. Also, current research has shown that LbL dipped deposition is not solely a surface process, but rather that the bulk film participates, resulting in some degree of interdigitation between layer pairs. This phenomenon is particularly true for superlinearly growing LbL systems, in which case during the first few layer pairs there is no bulk film into which adsorbing polyion can penetrate. As a result, research has shown that substantial growth does not appear to commence until several cycle repetitions have been completed.
This non-uniform initial regime phenomenon can be seen in the growth trend of the dipped (PDAC/SPS) n films, which appeared to begin steadily growing by the time the process has completed 5 cycles, as shown in FIG. 5 . Before the fifth cycle, the total film thickness was nearly zero. However, after this initial period the dipped films grew linearly at a rate of 3.8 nm per layer pair. In contrast, the sprayed films did not exhibit any initial non-linear growth regime. Film thickness grew linearly with number of layer pairs, and at the slightly lower rate of 2.7 nm per layer pair (in this case; sprayed layers were 77% of the thickness of dipped layers). Thus, in the case of (PDAC/SPS) n spray deposition can be used to suppress the initial nonlinear growth regime common with dipped deposition.
AFM images of the initial bilayer of PDAC/SPS deposition in the spraying case and dipping case were taken and compared. These thickness measurements for growth curves were performed on a Woolam XLS-100 Spectroscopic Ellipsometer, and checked using a Tencor P10 profilometer by scoring the film and profiling the score. A stylus tip force of 6 mg was used during profilometry to avoid penetrating the polymer film. ESEM analysis was performed on a FEI/Phillips XL30 FEG ESEM. Micrographs were taken at operating pressures between 0.9 and 1.5 mbar with a spot size of 3.0. Atomic Force Microscopy was conducted using a Digital Instruments Dimension 3100 in tapping mode at an amplitude set point of 0.8 V under dry conditions. In order to obtain high-resolution images, supersharp Si probes (Pacific Nanotechnology, SSS-NCH) were used to capture the image. Height and phase images were taken at scanning rates of approximately 1.5 Hz.
During adsorption by dipping, AFM imaging showed that PDAC adsorbs initially in clumps, or “islands”. This in turn influenced the morphology of the following SPS layer. As deposition continued, the islands were eventually bridged and even deposition occurred, reaching the steady-state growth regime. In contrast, during spray deposition no large islands of PDAC or SPS appeared during the first layer pair deposition. Images showed smooth surfaces with little coverage. The roughness of large islands that resulted in the initial growth regime during the dipping process was not a factor here.
As a consequence of the short exposure time of the polyion to the substrate during spraying, equilibrium cannot be reached. Therefore, less material was necessarily deposited. However, the fact that thick films were grown demonstrated that a 3 second spray of polyion was adequate for charge reversal to occur.
(SPS/PDAC) n is known to be one of the most stratified LbL systems. Therefore it is reasonable to assume that uneven charge density on the substrate, and thus roughness of initial layers, has the greatest influence on the initial growth (as opposed to lack of bulk film). In other words, the deposition of each successive layer is most influenced by the topography/charge density of the underlying layers. The AFM images showed that spraying produced thinner and smoother surfaces during the first layer pair, leading to linear growth from the outset. This could be simply due to the shorter deposition time, meaning that “islands” were still formed, but they were much smaller than in the dipped case. Alternatively, this result may be due to the fact that polyelectrolyte was introduced evenly and simultaneously to the entire substrate, before quickly draining away. Thus, the polymer chains were kinetically trapped to the point of contact with the substrate, whereas during dipping the chains were allowed to diffuse and complex with regions of higher charge density on the surface. This could also explain the smoother initial layer pairs measured for the spraying case. The difference in the initial growth suggested that the spray method is preferable for making very thin and uniform layers of strong polyelectrolytes.
While PDAC and SPS were used above, the invention is not limited to only these solutions. Other suitable polycations include, but are not limited to, poly(dimethyldiallylammonium chloride), poly(ethyleneimine), poly(allylamine hydrochloride), polyaniline, polypyrrole and poly(vinylbenzyltriamethylamine). Other suitable polyanions include, but are not limited to, poly(sodium 4-styrenesulfonate), poly(acrylic acid), Nafion, poly(methacrylic acid), poly(sodium styrene sulfonate), and sodium poly(styrene sulfonate).
Additionally, clay platelets, such as montmorillonite and bentonite, may be used.
Similar experiments were conducted using both dipped and sprayed films of (PAMAM/PAA) n assembled at pH 4. The growth trends of both dipped and sprayed films can be seen in FIG. 6 . In this case, an introductory non-linear growth period was observed using either deposition method. Interactions in the case of weak polyelectrolyte are known to be more complicated, and the branched geometry of PAMAM also played a factor. At pH 4, the tertiary amine groups in the dendrimers' interior were only partially protonated and therefore hydrophobic. Due to van der Waals forces between the interiors, PAMAM molecules will tend to aggregate on a weakly charged surface. Once the PAA layer was uniform, the stronger charge density plus the favorable interaction of carboxylic acid groups with primary amines was sufficient for uniform layer deposition. PAA is known to become more charged in the presence of positively charged amine containing polymers, making the interaction between the polyions even more energetically favorable.
In this case, film assembly was similar in both cases, with growth rates of 210 and 224 nm per layer pair for dipping and spraying respectively (sprayed layers are 107% of the thickness of dipped layers). AFM images of the first layer pair of sprayed PAMAM/PAA and of dipped PAMAM/PAA showed similar topologies. The AFM images indicated that in both cases the initial PAMAM layer deposited in aggregates of dendrimer. These aggregates were smaller in the sprayed case, again most likely because of shorter exposure time to the substrate. The surface after the first exposure to PAA in both cases showed more complete coverage. Spraying therefore can be used to create a denser, but still incomplete, monolayer of dendrimer aggregates.
The linearity of the spray deposition in FIG. 5 and FIG. 6 can be attributed to the physical mechanism behind spray-LbL deposition. In certain polyelectrolyte systems, either the polycation or the polyanion, or both, has the ability to diffuse throughout the film. It has been proposed that in these cases during the deposition period not only do polyions adsorb to the polyelectrolyte multilayer (PEM) surface, but chains also diffuse into the previously deposited PEM structure, building up an effective reservoir. During the successive exposure to the oppositely charged polyion, this reservoir is drawn to the PEM surface, creating more available material with which the adsorbing polyion can complex, and leading to a super-linear growth rate. Assuming a similar growth mechanism, the spray method should therefore minimize interlayer diffusion. The film is hydrated throughout the process, so the chains will still have some mobility, but diffusion of long molecules takes time, which is considerably shorter for spraying than it is for dipping. For systems that have been observed to grow super-linearly, it could be expected that spraying would reduce this effect. The highly charged nature of PAMAM molecules would imply the deposition of a tightly ionically crosslinked film composed of very flat layers exhibiting little interpenetration. With very little interpenetration, dipped and sprayed films grew at very similar rates.
Dendrimer encapsulated nanoparticles (DEN) were also used to coat a catalytic metallic nanoparticle onto a substrate. A stainless steel mesh was used as the substrate. To insure adequate coverage of the mesh, the vacuum system described above was used in conjunction with the apparatus. PAMAM dendrimers with Paladium nanoparticles in the center of the molecules were synthesized using techniques known to one of skill in the art. PAA was used as the anionic solution. These solutions were then sprayed in layers onto the mesh using the process described above. Layers of material were therefore added to the mesh. Thus, Paladium was able to be coated onto the mesh. This mesh could later serve as a catalytic support on which to perform reaction requiring a catalyst, such as but not limited to hydrogenation reactions. While this experiment utilized Paladium, the invention is not so limited. Any catalytic metallic nanoparticle, such as but not limited to platinum or silver, can be utilized to achieve this result. Similarly, while PAMAM and PAA were utilized above, any combination of DEN and polyanionic solution would also be suitable.
Other suitable dendrimers include, but are not limited to, poly(propylene imine).
Whereas Coulombic forces drive electrostatic LbL formation, hydrogen bonding can foster multilayer formation when a hydrogen-bond donor and acceptor are used. Deposition of this type is extremely sensitive to variations in solution pH. Thus the closed vessels and short deposition times inherent to the spray-LbL process, which are ideal for minimizing evaporation and controlling solution consistency, make the process well suited for hydrogen bonded systems. As expected, (PEO/PAA) n films deposited via the spray method yielded linear growth as shown in FIG. 7 . Again the presence of an introductory growth period was observed. After eight cycles were completed however, growth occurred at a constant rate of 30 nm per layer pair, uniformly coating the substrate.
Spray-LbL also proved advantageous for the deposition of colloidal nanoparticles. Success was demonstrated by alternating negatively charged titanium dioxide nanoparticles with positively charged PDAC. Particles tested had mean diameter of 7 nm and Zeta-potential of roughly −34 mV. In this case, contact time between sprayed solution and substrate was more than sufficient to adhere particles and develop constant linear growth, detailed in FIG. 8 , at a rate of 9.5 nm per layer pair. X-ray diffraction of a (TiO 2 /PDAC) 50 film, the results of which are shown in FIG. 9 , confirmed that anatase phase nanoparticles were in fact deposited in the film. Atomization immediately prior to contact with the substrate insured deposition of particles instead of agglomerates.
Other suitable colloidal nanoparticles include, but are not limited to, titania, ceria, alumina, and zirconia.
As a challenging test of the spray-LbL technique's ability to coat textile materials, DuPont® Tyvek® was selected as a substrate. Constructed by a proprietary flash-spinning technique, Tyvek® is made from very fine, high-density poly(ethylene) fibers. It is vapor permeable, yet water, chemical and abrasion resistant, making it extremely useful as a garment material for protection against hazardous environments including pesticides and herbicides. Uncoated Tyvek® is quite hydrophobic. The three dimensional texture of uncoated Tyvek® is well known; under magnification of 2000×, individual poly(ethylene fibers) can be observed. The ultra-fine mist generated as the solution exited the atomizing nozzle was capable of delivering charged species uniformly, even to a hydrophobic surface.
Microscope images showed macro scale uniformity of Tyvek when coated with 100 layer pairs of (SPS/PDAC) containing 0.10 M NaCl, typically added to increase deposition thickness. As ionic crosslinks formed between the polymer chains, salt ions were ejected, forming crystals on the surface. The short rinse time was not sufficient to dissolve the crystals, which were visible in the image. The salt was removed by soaking the coated Tyvek (SPS/PDAC) 100 in neutral pH water for a period of 15 minutes. Further magnification of the image showed that the soaking had only removed the salt crystals, leaving individually coated fibers behind. Roughness of the LbL film was seen, which was a result of salt crystals being formed during the deposition process (the salt crystals increase the surface roughness seen by each successive exposure of polyion). Longer rinse cycles (on the order of 1 minute) can be used to immediately rinse away the salt crystals, if surface roughness is not desirable. By soaking to remove the salt after deposition was complete, however, much short cycle times were achieved.
The process conformally coated the fibers even at varying depths within the surface of the material itself. Again, the ultrafine mist allowed very small droplets to transport the charged species, effectively wetting an otherwise hydrophobic material. Thus, this method was able to treat the macroscopic material with a hydrophilic coating. Contact angle can then be used to examine the hydrophobic or hydrophilic nature of the coating's surface, that it is uniform and that the surface properties of the substrate have been changed. In this example, a coating of (LPEI/PAA) 100 reduced the advancing contact angle of a droplet of water from ˜150° on uncoated Tyvek to less than 110°; a change of more than 40° in wetting contact angle. Contact angle measurements were performed by the standard sessile drop technique on an Advanced Surface Technology (AST) device. The contact angles described herein are advancing contact water angles, and were made by moving the substrate vertically until contact was made between a water drop on the tip of a syringe and the sample. The subsequent addition of a small amount of water to the water drop on the surface produced the static advancing angle with the surface in a few seconds.
In summary, the layer-by-layer method can be successfully utilized to deposit thin, uniform multilayered films. Unfortunately, the conventional practice of dipping substrates into solutions and waiting for electrostatic equilibrium to occur requires long process times, on the order of hours to days for a film of 50 layer pairs. Spray-LbL has been developed as a method capable of achieving drastically reduced process times by eliminating diffusion from the mechanism, but still allowing for conformal coating of three-dimensional structures. Furthermore, elimination of mass transfer by diffusion reduces the interpenetration of layer pairs within the film leading to linear, reproducible growth rates. In the case of both strong and weak polyelectrolytes, uniform deposition occured much more quickly than with dipping, making spraying an attractive option for making extremely thin but uniform films. Spray-LbL was capable of depositing several systems in which the driving force of film assembly was not electrostatic. It was also applied to spray deposit inorganic nanoparticles.
Spray-LbL deposition was used to deposit multilayer films on Tyvek, a hydrophobic textile material, from aqueous suspensions of polyelectrolytes. The ultra-fine mist produced from the apparatus was capable of transporting the charged species in such a manner that individual fibers within the material were conformally coated, resulting in a marked change in the material's hydrophilicity.
This technology decreased the process times required by conventional LbL techniques by more the 25-fold, while allowing for conformal coating of three-dimensional substrates with virtually no human interaction. This technology can also be scaled. The technology can be configured as an array capable of coating areas having large or irregular substrate surface areas, thereby making spray-LbL technology attractive on an industrial scale. | The present invention comprises an automated apparatus capable of spray depositing polyelectrolytes via the LbL mechanism with minimal or no human interaction. In certain embodiments, the apparatus sprays atomized polyelectrolytes onto a vertically oriented substrate. To counteract the effects of irregular spray patterns, the substrate is preferably slowly rotated about a central axis. In certain embodiments, the apparatus also includes a forced pathway for the droplets, such as a pathway created by using a vacuum. In this way, a thicker or three-dimensional substrate can be coated. In certain embodiments, the apparatus is designed so as to be scalable. Thus, through the use of multiple instantiations of the apparatus, a large or irregularly shaped substrate can be coated. Rolls of textile can therefore be coated using the apparatus. Additionally, the present invention includes a method to uniformly coat a substrate, such as a hydrophobic textile material, using aqueous solutions of polyelectrolytes. | 1 |
The present invention relates to an electrode package comprising a substantially flat electrode intended for use in an electrochemical cell. The electrode package is particularly usable in a membrane cell in a filter-press type of electrolyser. The invention furthermore relates to a use of the electrode package.
Electro-chemistry has industrially always been dominated by the production of chlorine-alkali and chlorate. These products have been the most economically important and have therefore attracted most interest. A variety of cell types have been developed during the course of time for these applications.
However, the dominating cell types, the mercury cell and diaphragm cell, retained their position for a long time, and the improvements which have occurred have only been marginal. Two great innovations have, however, given new impetus to development during the last decade. These two are the hydraulically stable ion exchange membranes and the dimensionally stable anodes.
As far as cell development is concerned, it has been a question of adapting the devices so that the greatest possible advantage could be taken of the novelties. The electrodes are often formed as permeable electrodes to impart thereto the greatest possible area, and to enable the membrane to be placed as close to the electrode as possible. One has also returned to filter press cells, since these are more suitable together with the two-dimensional membranes. Maintenance, however, has been a problem. There has been a desire to avoid the necessity of closing off a complete row of cells while e.g. a broken membrane or some other deficiency has been attended to. A proposed solution to this is to form each electrode pair as an individually exchangeable pack, e.g. as disclosed in U.S. Pat. No. 4,056,458.
A general characteristic of all these solutions is, however, that they are very strictly adapted to one process, usually a chlorine-alkali production. They are seldom suitable for other electro-chemical processes. This is particularly in evidence when the volumes are small and the products can no longer bear the costs of specially adapted structures. This has been found to be the case in the organic electro-chemical field above all, where many processes which are promising per se have been kept back by the necessity of also constructing suitable electrolysis equipment.
A flexible cell which is versatile in use must meet requirements which are in some respects not the same as those for a chlorine cell. What is common is the requirement of small electrode spacing and the desirability of some kind of construction in packages. The electrodes must be easily exchangeable, however, since different processes require different electrode materials. Furthermore, the cell must be constructed of a material resistant to corrosion in as many conceivable electrolytes as possible. It is also known that many metals disturb the electrode processes and lead to the poisoning of the electrodes. A cell made from an inert plastics material would thus be very desirable. If the components of the cell can be injection moulded, the precision can be achieved which is required for proper sealing and the avoidance of too large potential gradients across the electrode surface, due to varying electrode spacing. It would also be possible to keep the price down, if manufacturing series can be reasonably long. Injection moulding requires, however, that the number of differently shaped parts can be kept low.
All this is enabled by the new electrode package in accordance with the present invention. In turn, this is achieved by the electrode package being given the characterizing features apparent from the appended patent claims.
What is characterizing for the electrode package according to the invention is, thus, that it comprises a substantially flat electrode surrounded and located by two mutually engaging, substantially flat inner frames with inlet and outlet channels for electrolyte, the central opening defined by the inner frames, which admits access of electrolyte to the electrode, being covered by a grid on each inner frame, that both inner frames in turn are surrounded, along their peripheral edges, by a substantially flat outer frame having at least one hole for supplying, and at least one hole for discharging electrolyte, at least one of the respective holes being in communication via a channel with the inlet and outlet channels of the inner frames, the outer frame being locked, at its inner edge, between both inner frames with the aid of locking means preferably arranged solely on the inner frames for directly locking these to each other, that at least one of the inner frames, on the side facing towards the electrode and opposite the inlet channel, is provided with a boss-like projection intended to serve as a striking surface for incoming electrolyte and for distributing it laterally, and at least in its lower portion with a plurality of constriction means for the electrolyte, preferably projections, between which are formed channels in to the electrode, that at least the second of the inner frames in its upper portion is provided with a plurality of said constriction means, preferably projections, and that the grids of the inner frames comprise strips, or ribs, lying in two planes, which form oblique angles with the electrolyte flow supplied to the electrode.
Thus, the electrode is surrounded by and inserted between the inner frames along its circumferential, or peripheral, edge, and it is located preferably by resting in recesses at the inner edges of the inner frames.
As to the grid within each of the inner frames, it is dimensioned so as to cover the central opening defined by each inner frame, and the opening is contiguous to recesses in the inner frame, which recesses form a chamber for incoming electrolyte and a chamber for outgoing electrolyte. Preferably, the electrode as well as the inner frames have substantially rectangular shapes, said chamber for incoming electrolyte and said chamber for outgoing electrolyte being arranged in the bottom and top edges, respectively, of the inner frame.
The term "opposite" in connection with the boss-like projection is to be interpreted in a broad sense. Thus, the boss-like projection is arranged in the chamber for incoming electrolyte so as to prevent the electrolyte from passing directly into the electrode chamber without any lateral distribution thereof.
In accordance with a preferred embodiment of the invention, both inner frames and the outer frame are made from an injection-mouldable polymer and moulded each by itself in two separate moulds. The inner frame and grid, thus, constitute an integral unit and the grid is suitably attached to the inner edge of the central opening of the inner frame.
Thus, the new electrode package structure for the first time enables the manufacture of synthesis cells from injection-moulded frame parts. Thanks to the new construction, the injection moulding technique will be economically feasible as a result of building into only two frame parts surrounding the electrode, a number of technical functions required for a wide range of processes; only two moulds are required.
The present invention, thus, minimizes the number of differently shaped constructional elements crucial for the cell function, which is an economic condition, since the injection moulding tools are expensive. A large number of identical details can, however, be produced in each separate mould at low cost, and not least important is that the detail material can be selected with reference to resistance to process chemicals. For example, materials of the polyvinyl fluoride or polyvinylidene fluoride type can be used (e.g. "Dyflor 2000" or "Kynar"), which materials are almost impossible to machine into structural elements with thin cross sections and severe tolerance requirements. To accomplish a good sealing of the cell, location and sealing of membrane, location of the electrode, small dimensional deviations in electrode spacing, and above all, an electrolyte distribution system and barrier system for controlled and uniform flow distribution, it is absolutely necessary to have high dimensional tolerance requirements for those details in a cell structure which are embraced by these functions. The injection moulding technique is the only manufacturing method which meets these requirements for this type of material.
Although polyvinylidene fluoride has been mentioned above as an especially suitable material, the frames can very well be moulded in other materials, e.g. polypropylene, polystyrene, nylon, etc., i.e. any kind of injection-mouldable plastic material.
By the special electrolyte distribution configuration of the inner frames, which has been made possible by the precision obtainable with injection moulding technique, a well-defined, so-called plug flow through the cell has been obtainable. Thus, in the present case the term electrolyte distribution configuration includes the boss-like projection of the inner frames, which is suitably so high as to engage against the facing inner frame, and the constriction means which preferably are constructed of a plurality of small projections between which there are formed channels in to the electrode. The latter projections should also be high enough to engage against the electrode or the opposing inner frame.
Since the above-mentioned case with two moulds only (for the inner and outer frame, respectively) represents the ideal case, a preferred embodiment of the invention is the case when the two inner frames are identical with each other. This in turn means that the boss-like projections as well as the constriction means are present on both inner frames and are so high as to bear on each other when the electrode package is assembled.
The width of the boss-like projection is adapted to the incoming electrolyte flow, i.e. so that the latter is laterally directed in both directions right up to the outmost channel into the electrode. The electrolyte distribution configuration enables an extremely uniform distribution of electrolyte across the whole electrode, i.e. across the whole width as well as height of the electrode. The plug flow, thus, means that the electrolyte flow over the electrode has a substantially straight front.
The grid of the inner frames, which is preferably a part of the frames themselves, serves several important purposes. Since the grid is comprised of ridges in two planes, turbulence will be generated, since the flow is alternately forced to pass over and under said ridges. The fact that the ridges form oblique angles to the electrolyte flow supplied to the electrode means that gas liberation is facilitated, since gas bubbles do not fasten onto the grid. A specially preferred angle for the ridges relative to the electrolyte flow is between about 30° and 60°, e.g. about 50°. In the case of a membrane cell, the grid furthermore constitutes a support for the membrane that separates cathode and anode electrolytes. The shape of the grid improves the yield of the reaction, by its action on the electrolyte flow, since it gives the condition for an even current load across the whole of the electrode surface, as well as improves the mass transport.
The primary function of the outer frame is to make room for holes for inflow and outflow of electrolyte to and from the cell, respectively. These holes are suitably placed at the bottom and top of the frame, respectively. From said holes at least one distribution channel communicates with the inlet and outlet channels, respectively, of the inner frames.
In synthesis cells of the kind described above, a separation of the electrolyte system by means of a membrane is often required, so as to distribute one electrolyte flow round the anode and another around the cathode. Two separate electrolyte circuits are, thus, involved, which must be fed into and distributed in the cell according to a regular system. In the prior art, this has often required the necessity of a great number of differently shaped constructional elements. In the particularly preferred embodiment of the present invention, which signifies that the outer frame has two holes for supply, and two holes for discharge of the electrolyte and that merely one of the respective holes communicates with the inner frames via a distribution channel, these two functions are executed by one and the same detail. Merely by turning alternate outer frames 180°, the electrolyte can be distributed alternately to the anode and cathode electrolyte departments, respectively. By turning the outer frame in this way, the current supply means of the electrode, which will be described more in detail below, will alternately pass through one or the other side, which to a great extent facilitates interconnection of these for parallel or series connection. A greater number of holes for supply and discharge of the electrolyte are also conceivable in the cases where more than two different electrolytes are to be distributed in the cell, e.g. in electrodialysis.
Another important function that is built into the outer frame is connected with the use of the electrode package in a membrane cell. In this case the outer frame on one side is provided with several, e.g. three, circumferential edges, or ridges, or projections. Hereby, combined clamping and sealing of the membrane is obtained. Thus, the membrane separating the electrolyte chambers is attached to the ridges in a simple way, by simply pressing the membrane against the ridges.
This attachment gives combined ridge and labyrinth sealing, where the ridge seal means an effective utilization of the membrane area, and where the labyrinth seal ensures that the risk of leakage to the outmost groove, after the last ridge, and thus out from the electrolyte department will be extremely small. By the structure proposed, it has thus been possible to minimize the requisite membrane area in relation to the electrode area, which is of great economic importance, since the membrane cost is an expensive item in this connection. The seal can furthermore be provided without using sealing compounds, gaskets or O-rings, which must be regarded as a considerable advance compared with current technique.
The locking means for locking the inner frames to the outer frame suitably comprises at least two male and female parts placed respectively on the inside of either inner frame and integral with the respective frame, since such locking means provide for very simple assembly. Furthermore, the locking means have preferably mutually differing configuration, thus avoiding the frames to be turned wrong in the assembly. Locking is, thus, preferably carried out so that both inner frames are locked directly to each other, the inner frames sinking into grooves on the inner edge of the outer frame and being thus located laterally and vertically. However, the invention is not limited to said locking method, but other alternatives are of course directly to either side of the outer frame with the aid of locking means.
The package principle described above, with one outer and two inner frames about each electrode should be unique, and substantially facilitates handling. The principle furthermore enables handling a whole stack, comprising several electrode packages, as one unit. However, in spite of the package principle, the invention signifies that electrodes and membranes can very easily be removed and exchanged, which must be considered a very essential contribution to the technique in this field.
The use of the outer frame in accordance with the invention means a still further advantage, since it enables leading the current conductors via holes through the edge of the frame. Accordingly, practically all the sealing problems usually encountered in conjunction with current conductors are eliminated.
According to a particularly preferred embodiment of the invention, the current conductors of the electrode are placed on one side edge thereof, the holes in the outer frame and inner frames, respectively, for passage of the current conductors being made in a corresponding way in the side edge of the outer frame and inner frames, respectively. By coupling directly laterally between series-connected electrodes the advantage of a short distance for current transmission is obtained, resulting in small conductor area and good cooling possibilities. The current conductors are furthermore suitably given a circular cross section, which also contributes to their being easier to seal then current conductors previously used, which were usually in the shape of flat tongues arranged on the electrode plate and upstanding from its upper edge. By turning alternate outer frames 180°, there is also obtained the above-mentioned advantage of current conductors alternatingly originating from one or the other side.
The invention also relates to the use of the abovedescribed electrode package in a membrane cell in an electrolyser of the filter-press configuration, where its advantages should be self-evident to a person skilled in the art.
BRIEF DESCRIPTION OF THE DRAWING
The invention will now be further described in connection with the accompanying drawings in which:
FIG. 1A shows a front view of an inner frame, FIG. 1B shows a section seen from above of the same frame, and FIG. 1C shows a section seen from one side of said frame;
FIG. 2A shows a front view of the outer frame, FIG. 2B shows a section of the same frame seen from one side, and FIG. 2C shows part of the rear side of said frame;
FIG. 3 shows an electrode plate;
FIG. 4 shows a front view of an electrode package in accordance with the invention;
FIG. 5 shows a side view of a whole cell package with several electrode packages arranged side-by-side;
FIG. 6 shows the cell package from FIG. 5 seen from above;
FIG. 7 shows a cross section of detail A from FIG. 5;
FIG. 8 shows a cross section of detail B from FIG. 6;
FIG. 9A shows a cross section through a cell with a permeable electrode, and FIGS. 9B and 9C show different flow patterns for cells with permeable electrodes;
FIG. 10A shows a cross section through a bipolar cell, and FIG. 10B shows a current flow pattern for a bipolar cell; and
FIG. 11 schematically shows the electrical connections and the division and forming of two separate electrolyte systems for an entire cell unit.
DETAILED DESCRIPTION
FIG. 1A illustrates an inner frame 1 with a rectangular shape and with a bottom inlet 2 and a top outlet 3 for electrolyte. In the illustrated embodiment, the inlet and outlet are grooves in the frame arranged at the middle of its lower edge 4 and upper edge 5, respectively. The lower edge 4 is so wide as to accomodate a distribution chamber 6 in which the electrolyte flow has time to be distributed into a uniform flow before it is fed into the electrolysis chamber in contact with the electrode. In this distribution chamber 6 directly opposite the inlet 2, there is a boss 7, against which the electrolyte flow is intended to strike and be distributed laterally. The chamber 6 is contiguous to the opening 8 defined by the frame 1, this opening being intended to give the electrolyte access to the electrode, and at the edge of the opening 8 the chamber 6 is provided with a plurality of projections 9, serving as constrictions to increase the pressure drop of the electrolyte. In the illustrated embodiment, these projections are evenly distributed, but the invention is of course not restricted to any special distribution or any special appearance of the projections. Channels 10 are, thus formed between these projections, said channels giving rise to an extremely uniform electrolyte distribution with a plug flow. The illustrated embodiment of the inner frame is also provided at its upper edge 5 with a chamber 11, having a plurality of projections 12, which are preferably uniformly distributed and in register with the projections 9 in the lower chamber 6, so that the flow pattern will be even more homogenous.
The opening 8 of the inner frame is covered by a grid 13 which, in the embodiment shown, is integral with the frame and attached to the inner edge of the central, rectangular opening 8 of the inner frame. As will be seen from the drawing, the grid 13 comprises inclined ribs or ridges 14, 15, where one row of mutually parallel ribs 14 lie in one plane and the other row of mutually parallel ribs 15 is above the first row in a plane parallel to the plane formed by the first row of ribs 14. In the illustrated embodiment of the grid, the angle α is about 50° between the ribs 14 and 15, respectively, and the supplied electrolyte flow, or the longitudinal direction of the frame.
Finally, the inner frame 1 is provided with two locking means 16, 17, each at its lower edge 4 and upper edge 5, respectively. These locking means 16 and 17 are mutually dissimilar, to avoid incorrect orientation of the frames when assembled in the outer frame. Furthermore, 31A shows holes for the passage of the current supply means of the electrode.
FIG. 1B shows a section taken along the line B--B in FIG. 1A, and FIG. 1C shows a section along the line A--A in FIG. 1A. The side of the frame 1 facing away from the electrode is thus, in principle, a smooth frame, the opening 8 of which is covered by the grid 13, which is preferably injection-moulded integral with the rest of the frame.
FIG. 2A illustrates an outer frame 20 which is at the bottom provided with two holes 21 and 22 for the supply of electrolyte, and in a corresponding way it is provided with two holes 23 and 24 for discharge of electrolyte. From these holes there are distribution channels 25 and 26 (in this case illustrated from the holes 22 and 24, respectively) to the opening 27 defined by the outer frame 20, said channels being intended for communication with the inlets 2 and outlets 3, respectively, of the inner frames. The frame 20 is furthermore provided with projections or ridges 28, going all the way round, in this case three such ridges, functioning as a so-called labyrinth seal and as attachment for a membrane in a membrane cell. Grooves 29 and 30 for O-ring seals are also shown in the figure for the holes 21-24 and the frame 20, respectively.
FIG. 2B shows a section along the line A--A in FIG. 2A, and apart from the details shown in FIG. 2A there can be seen two holes 31B going through the side edge of the frame 20, and intended for passage of the electrode current conductors.
FIG. 2C illustrates a portion of the rear side of the outer frame 20 from FIG. 2A with the holes 23 and 24 and the opening 27. It will be seen from the figure that the rear side is smooth, i.e. not provided with the circumferential ridges 28.
FIG. 3 illustrates a homogenous rectangular electrode plate 32, intended for placing between the inner frames 1, it being suitably somewhat larger than the opening 8 in the inner frames so as to be accomodated in a circumferential groove therein. The electrode plate 32 is provided with two current supply conductors 33 in the form of circular rods which are placed at one long side of the rectangular electrode plate, and directly opposite corresponding holes 31 in the outer frame.
FIG. 4 shows a front view of the electrode package in the assembled condition, with the electrode plate 32 disposed between the two inner frames 1, which are in turn locked to each other, and with the outer frame 20 locked therebetween. Furthermore, the figure shows the O-ring grooves 29 around the outer frame holes 21-24 which can also be termed electrolyte main channels, and the O-ring groove 30 outside the peripheral ridges 28 on the outer frame. The current supply conductors 33 project through the long side of the outer frame 20.
In FIG. 5 there is shown a side view of a whole cell package with a plurality of electrode packages 34 according to the invention arranged side-by-side in a filter press configuration, and in FIG. 6 the same cell pack is shown from above. As will be seen from FIG. 6, the current supply conductors 33 are alternately taken out via one or the other of the long sides of the outer frames, the electrode plates thus being alternately positive and negative, which has been marked in FIG. 5.
FIG. 7 shows in cross section that part of FIG. 5 which has been denoted by A, and FIG. 8 shows in cross section part B from FIG. 6.
There is, thus, illustrated in FIG. 7 two electrode packages 34 with intermediate membranes 35 and O-rings 36. The remaining details shown will not be described closer, but are only illustrated by means of the previously used reference numerals.
FIG. 8 shows the outer frame 20 with ridges 28 and O-ring 36, as well as both inner frames 1 with grid 13 and current supply conductor 33.
The structure illustrated in the above figures can be said to relate to a cell embodiment for a mono-polar, separated (with respect to the electrolyte) cell structure with fixed homogeneous electrodes. However, by some simple changes in the frame portions of the structure, or alternatively its electrodes, the cell structure can be modified within the scope of the invention into, inter alia, a monopolar divided cell with porous through-flow electrodes. The bottom electrolyte intake is sealed on one side, the electrolyte being distributed up only on one side of the porous electrode, to pass therethrough and be led off along the opposing electrode side at the top of the cell. Sealing at the top is effected on the opposite side, compared with the bottom. The grid, which also can be termed a support for the membrane, should naturally be included in this embodiment also, and is assumed to be injection moulded together with the inner frame, as mentioned previously.
The through-flow electrode, which can e.g. be made of porous graphite, porous titanium, a mesh electrode, etc., can be used in such processes where it is particularly important that the specific electrode area with which the electrolyte comes into contact, is large.
A cell with a permeable electrode is shown in cross section in FIG. 9A, where the arrows illustrate the electrolyte flow in the cell. For the sake of clarity, the inner frame grids have not been drawn in the Figure, but as mentioned above, it is assumed that they are present. For intake and discharge, respectively, of electrolyte, the outer frame is provided with holes 22 and 24, respectively, as previously, which holes are in communication via channels 25 and 26 with the inner frame inlets and outlets, respectively. The outer frame furthermore has O-ring grooves 29 and 30, as well as ridges 28, against which the membrane 35 is clamped. A porous through-flow electrode 32 is arranged between the inner frames 1. Since the left-hand inner frame is sealed downwards at 37 and the right hand inner frame upwards at 38, the electrolyte will pass into the right-hand electrolyte gap 39, pass through the electrode and into the left-hand electrolyte gap 40 to exit from the electrolyte chamber at the left of the electrode 32.
Different flow patterns are conceivable for cells with through-flow electrodes, and are shown schematically in FIGS. 9B and 9C, where the electrodes are denoted by 32 and the membranes by 35. The electrode charge is denoted by + or - and the electrolyte flow is denoted by arrows.
Another modified cell structure within the scope of the invention is a bipolar divided cell with fixed homogenous electrodes, where the anolyte (electrolyte for the anode side electrode) is alternatingly led in on one side, and the catholyte on the other side of the bipolar electrode. Such a bipolar cell is illustrated in cross section in FIG. 10A, where the reference numerals are the same as previously for details which have been illustrated previously. The differences which are present in relation to previously illustrated embodiments are that the outer frame distribution channels 25 and 26 have been given the appearance shown in FIG. 10A, i.e. with the left-hand electrolyte chamber 41 in communication, for example, with the holes 21 and 23 in the outer frame and with the right-hand electrolyte chamber 42 in communication with the two other holes 22 and 24 in the outer frame. Furthermore, the inner frames in both upper and lower chambers 11 and 6, respectively, are provided with barrier portions 43 and 44 for partitioning off separate chambers on either side of the electrode when the two inner frames are assembled against each other. The inner frame grid is not shown in this case either, but is assumed to be incorporated.
An example of the flow pattern for a bipolar cell is illustrated schematically in FIg. 10B, where the reference numerals and denotations have the same meanings as in FIGS. 9 B and 9C. Accordingly, one electrolyte is distributed to all negative sides of the electrode and the other to the positive sides thereof.
Further cell variations are conceivable. Common for these cell structures is that the same basic structure elements (outer and inner frames) are still used. The only modifications which are required in the injection moulding tools are modified coring for the distribution channels or a simple change of the barrier portions.
Finally, in FIG. 11 there is schematically illustrated the electrical connections as well as the division and forming of the two separate electrolyte systems for a complete cell unit consisting of six cell packages 45 with twenty cells each. The electrode package according to the invention is denoted by the numeral 34, and there are membranes between each package. Current conductors 33 and the respective charges have been denoted. Electrolyte is supplied at 45 to all negative electrodes, and at 46 to all positive electrodes. The reference numeral 47 relates to valves.
The depicted unit, thus, consists of 10-11 positive electrodes connected in parallel, and the corresponding negative electrodes connected in parallel. Six stacks of these are then connected in series.
The electrode packages in accordance with the invention can be used, apart from in conjunction with the processes mentioned in the introduction, in cells, where e.g. the following compounds are produced:
1. Reduction of oxalic acid to glyoxylic acid.
In such a process the catholyte consists of a saturated aqueous solution of oxalic acid and the anolyte of diluted sulphuric acid. The electrodes are suitably manufactured from lead and the cell is provided with a cation exchange membrane. The glyoxylic acid content should not be allowed to exceed 1 mole/dm 3 . At a temperature of 14° C. and a current density of 20 A/dm 2 , a material yield of 98% and a current yield of 75% were obtained.
2. Oxidation of cerium(III) to cerium(IV).
Sulphurous solution of cerium(III)sulphate is oxidized on a lead dioxide anode. The catholyte consists of diluted sulphuric acid, the cathode of steel, while the membrane is of the anion exchange type. With an input concentration of 0.1 mole/dm 3 and a current density of 1 A/dm 2 , a current yield of 83% was obtained. When the oxidization was instead carried out on a cerium nitrate solution (0.4 mole/dm 3 ) with an anode of platinized titanium the current yield rose to 89%.
These processes are solely some examples of the innumerable reactions for which the new cell structure can be utilized.
While the invention has been described above with reference to rectangular shapes of the electrode and frames, at the same time expressions related to the rectangular shape such as side edge, top and bottom edges and chambers, etc., being used, it is of course not limited to said shapes, although they are preferable per se. Thus, the electrode and frames can be given almost any shapes without deviating from the inventive idea. In such cases the terms "side edge" as well as "upper", or "top", and "lower", or "bottom", will be related to the ultimate use of the electrode package in an electrolyser and what can there be considered "sideways" or "upwards" and "downwards". | An electrode package is disclosed which comprises a substantially flat elrode (32) surrounded by two substantially flat inner frames (1) which are surrounded by a substantially flat outer frame (20) with holes (21, 22) for supply of electrolyte to and holes (23, 24) for discharge of electrolyte from the electrode. Each of the inner frames is provided with a grid (13) that improves the electrolyte flow and serves as a support for a membrane when used in membrane cells, and furthermore with flow-distributing projections and possibly barriers, making it possible to achieve varying flow patterns for the electrolyte with the same basic construction. The outer frame is preferably provided with ridges, going all the way round, for the simple fitting and sealing of a membrane against it. The electrode package will, thus, be particularly suitable for use in membrane cells in electrolyzers of the filter-press type, said use also being described herein. The electrode current conductors (33) are suitably arranged in the form of circular rods on the long side of the electrode, which is preferably rectangular, and taken out through holes in the frames. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application Ser. No. 10/377,491, filed on Feb. 28, 2003 now U.S. Pat. No. 7,259,214 and U.S. patent application Ser. No. 10/378,957, filed on Mar. 3, 2003, both of which are incorporated in their entirety by reference herein.
FIELD OF INVENTION
This invention relates generally to co-polymerization of olefins with functionalized monomers; more particularly to the design and synthesis of substituted olefins functionalized with free radical initiators, copolymerization with ethylene and subsequent grafting of commodity monomers from the resultant ethylene copolymers via controlled free radical polymerization.
BACKGROUND OF THE INVENTION
It is of interest to incorporate polar functionalities into polyolefin materials in a controlled manner, unfortunately most polyolefin initiator systems are sensitive to polar groups and as such are deactivated in the presence of functionalized comonomers [1]. Recent advances in polyolefin catalysis have improved functional tolerance, however, few catalysts are able to incorporate large amounts of functionalized comonomer [2, 3] and even fewer can incorporate inexpensive functionalized commodity monomers via a polymerization reaction that can be used to create higher order polymer architectures, such as block-copolymers, tapered copolymers and tetrablock copolymers [4].
BRIEF SUMMARY OF THE INVENTION
The present invention fulfills the need for high incorporation of functionality in polyolefin materials using commercially relevant monomers. In the case when a quasi-living metal mediated copolymerization is used, the control afforded by this and the living free radical technique allow for access to a wide range of polymer architectures that bear predominantly polyethylene backbones with grafted side chains of functionalized commodity monomer.
In one embodiment, a process for producing an initiating monomer is disclosed comprising combining an amount of 5-norbornen-2-ol with an hydride or amine for a predetermined amount of time to form a mixture; and adding an amount of an alkyl or acyl halide to said mixture.
In a more particular embodiment, a process for producing an initiating monomer is disclosed where an amount of 5-norbornen-2-ol is combined with potassium hydride, or triethylamine; and adding an amount of an halide selected from a group consisting of N-(1-(4′-chloromethyl)phenylethoxy)-2,2,6,6-tetramethylpiperidine, 2,2,5-trimethyl-3-(1-(4′-chloromethyl)phenylethoxy)-4-phenyl-3-azahexane, and 2-bromoisobutyric bromide.
In one construction, initiating monomers that can be prepared by the above processes include, but are not limited to, 5-norbornen-2-yl 4-(1-(1-(2,2,6,6-tetramethylpiperidinoxy))ethyl)benzyl ether, 5-Norbornen-2-yl 4-(1-(3-(2,2,5-trimethyl-4-phenyl-3-azahexoxy))ethyl)benzyl ether, and 5-Norbornen-2-yl 2-bromo-2-methylpropionoate.
In one embodiment, a process for the co-polymerization of an olefin, is disclosed comprising polymerizing an olefin with an initiating monomer; and conducting said polymerizing in the presence of an metal compound, said metal compound comprising a Group 10 transition metal complex, where the complex is comprised of any combination of two neutral metal complexes, the combinations having the general formulas (I-IV):
wherein:
M is a Group 10 transition metal; A is π-allyl, substituted π-allyl, π-benzyl, or substituted π-benzyl; X is N or P; Y is O, CH 2 , or S; L is N or P or a structure that is capable of forming a neutral two electron donor ligand; L 1 is a neutral monodentate ligand and L 2 is a monoanionic monodentate ligand, or L 1 and L 2 taken together are a monoanionic bidentate ligand, provided that said monoanionic monodentate ligand or said monoanionic bidentate ligand is capable of adding to said olefin; B is a bridge connecting covalently an unsaturated carbon and L; is a single or double bond; R 1 , R 2 , R 3A and R 3B are the same or different and are each independently hydrogen, hydrocarbyl group, or substituted hydrocarbyl bearing functional group; R 3B is nothing when B is connected to L by a double bond.
In one construction, the olefin is selected from the group consisting of a compound of the formula R 5 CH═CH 2 , wherein R 5 is hydrogen, a hydrocarbyl group, or a substituted hydrocarbyl bearing functional group; cyclopentene; styrene; norbornene; a polar olefin; substituted cyclopentene; substituted styrene; substituted norbornene derivative having a functional group; and a combination thereof. In a more particular construction, R 1 and R 3 are (2,6-diisopropylphenyl); R 2 is methyl; X and L are nitrogen; Y is oxygen; B is carbon; L 1 is CH 2 Ph; and L 2 is PMe 3 .
In yet another construction, the metal complex comprises a combination of [N-(2,6-diisopropylphenyl)-2-(2,6-diisopropylphenylimino)propanamidato-κ 2 N,O](η 1 -benzyl)nickel(trimethyl phosphine) and bis(1,5-cyclooctadienyl)nickel.
The products prepared by the above co-polymerization process are random co-polymers, block co-polymers, or tapered co-polymers.
In yet another construction, the above polymerizing reaction also includes the presence of an unstabilized n-butyl acrylate so as to produce grafted tetrablock copolymers, grafted end functionalized/block copolymers, grafted random copolymers, grafted tapered copolymers, or grafted tapered tetrablock copolymers.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawing in which:
FIG. 1 shows chemical structures of some typical norbornene initiating monomers.
FIG. 2 shows several types of co-polymer structures that can be synthesized using the initiating monomers.
FIG. 3 shows several types of grafted co-polymer structures that can be synthesized using the initiating monomers.
FIG. 4 shows a gel permeation chromatograph overlay graph.
DETAILED DESCRIPTION OF THE INVENTION
Described herein are novel monomers bearing functionalities capable of initiating control free radical reactions (herein “initiating monomers”), and a novel process using these initiating monomers for the formation of well-controlled polyethylene graft polymers where the graft component is derived from controlled free radical polymerization reactions.
All examples were performed under an inert atmosphere using standard glove box and Schlenk techniques. Solvents for syntheses like toluene, THF, hexane and pentane were distilled from benzophenone ketyl as required. All polymerization reactions were carried out in a glass reactor as described previously [5]. Toluene for polymerization runs was distilled from sodium/potassium alloy. Nickel was chosen as the transition metal for the metal complex.
L(′Pr 2 )Ni(CH 2 Ph)(PMe 3 ) [L═N-(2,6-diisopropylphenyl)-2-(2,6-diisopropylphenylimino)propanamide] [5] and Ni(COD) 2 [6] were synthesized as reported and purified by re-crystallization prior to polymerization use. NMR spectra were obtained using a Varian Unity 400 or 500 spectrometers. IH NMR and the 13 C NMR spectra of the polymers were obtained in mixed solvent (C 6 D 6 /1,2,4-trichlorobenzene 1:4 ratio in volume) at about 115° C. and (C 6 D 6 /o-dichlorobenzene about 7% v/v for polyethylene polymer and about 9% v/v for the copolymers) at about 120° C. GPC analyses were done at Mitsubishi Chemical Corporation, Japan, in o-dichlorobenzene in about 135° C.
Initiating monomers can be formed via the nucleophilic addition of 5-norbornen-2-ol to an appropriate alkyl or acyl halide. The structures of typical norbornene monomers are shown in FIG. 1 .
Substituted olefins other than 5-norbornen-2-ol that can be used to synthesize the above initiating monomers include, but are not limited to, enols, hydroxy substituted styrenes, or hydroxy substituted acrylates.
Alkyl or acyl halide that can be used to synthesize the above initiating monomers include, but are not limited to, N-(1-(4′-chloromethyl)phenylethoxy)-2,2,6,6-tetramethylpiperidine, 2,2,5-trimethyl-3-(1-(4′-chloromethyl)phenylethoxy)-4-phenyl-3-azahexane[7], and 2-bromoisobutyric bromide.
The above initiating monomers can be used to form different copolymer architectures including, but not limited to, tetrablock copolymers, end functionalized/block copolymer, random copolymers, tapered copolymers, and tapered tetrablock copolymers (see FIG. 2 ).
In one embodiment, these initiating monomers can be used to form a variety of graft polymer structures including, but not limited, to grafted tetrablock copolymers, grafted end functionalized/block copolymers; grafted random copolymers, grafted tapered copolymers, and grafted tapered tetrablock copolymers (see FIG. 3 ).
The method to produce graft polymers consists first of the incorporation of controlled free radical initiator functionalized norbornenes (inimer) into polyethylene via copolymerization of the inimer with ethylene. This is accomplished by employing a functionality, tolerant and structure controlling Ni initiator system. In a second step, the resulting polymers bearing initiator functionality can then initiate polymerization resulting in graft polymers.
EXAMPLE 1
5-norbornen-2-yl 4-(1-(1-(2,2,6,6-tetramethylpiperidinoxy))ethyl)benzyl ether (Initiating Monomer 1) is synthesized according to the schematic below:
The synthesis was carried out under an inert atmosphere. To a 5-norbornen-2-ol solution (0.500 g, 4.54 mmol in 100 mL of THF) was added potassium hydride (0.188 g, 4.70 mmol) in small portions over 15 minutes with stirring. After 30 min, N-(1-(4′-chloromethyl)phenylethoxy)-2,2,6,6-tetramethylpiperidine [7] (1.27 g, 4.1 mmol in 30 mL THF) was added over 5 minutes. After stirring at room temperature for 24 hrs, the mixture was filtered through a sintered glass filter and the resultant filtrate was evaporated to dryness. The residue was redissolved in ether (250 mL) and washed with water (3×500 mL). The organic layer was then dried and the solvent removed in vacuo to give 1.45 g of crude product. The product was then purified by column chromatography using EMD™ Silica Gel 60 as the stationary phase, eluting with 40:1, then gradually increasing to 20:1 hexane/ethyl acetate to afford 1.15 g (73% yield) of pure product as a viscous pale yellow oil. 1 H-NMR (200 MHz, CDCl 3 , 298 K): endo isomer; δ 7.3-7.1 (m, 4H), 6.30 (m, 1 H), 6.01 (m, 1 H), 4.73 (q, 1 H), 4.43 (s, 2H), 4.18 (m, 1 H), 3.05 (m, 1 H), 2.73 (m, 1 H), 1.95 (m, 1 H), 1.60-0.70 (m, 21 H), 0.60 (br. s, 3H); exo isomer, δ 7.3-7.1 (m, 4H), 6.13 (m, 1 H), 5.86 (m, 1 H), 4.71 (q, 1 H), 4.43 (s, 2H), 3.45 (m, 1 H), 2.88 (m, 1 H), 2.73 (m, 1 H), 1.75-0.75 (m, 22H), 0.63 (br. s, 3H).
EXAMPLE 2
5-Norbornen-2-yl 4-(1-(3-(2,2,5-trimethyl-4-phenyl-3-azahexoxy))ethyl)benzyl ether (Initiating Monomer 2) is synthesized according to the schematic in below.
The synthesis was carried out under an inert atmosphere. To a 5-norbornen-2-ol solution (0.500 g, 4.54 mmol in 100 mL of THF) was added potassium hydride (0.188 g, 4.70 mmol) in small portions over 15 minutes with stirring. After 30 min, 2,2,5-trimethyl-3-(1-(4′-chloromethyl)phenylethoxy)-4-phenyl-3-azahexane [7] solution (1.52 g, 4.06 mmol in 30 mL THF) was added over 5 minutes. After stirring at room temperature for 24 hrs, the mixture was filtered through a sintered glass filter and the resultant filtrate was evaporated to dryness. The residue was redissolved in ether (250 mL) and washed with water (3×500 mL). The organic layer was then dried and the solvent removed in vacuo to give 1.72 g of crude product. The product was then purified by column chromatography using EMD™ Silica Gel 60 as the stationary phase, eluting with 40:1, then gradually increasing to 20:1 hexane/ethyl acetate to afford 1.39 g (76% yield) of pure product as a viscous colorless oil. 1 H-NMR (200 MHz, CDCl3, 298 K): endo isomer, δ 7.5-7.1 (m, 18H, both diastereomers), 6.35 (m, 2H, both diastereomers), 6.04 (m, 2H, both diastereomers), 4.92 (q+q, 2H, both diastereomers), 4.52 (s, 2H, diastereomers A), 4.47 (d, 2H, diastereomers B), 4.22 (m, 2H, both diastereomers), 3.42 (d, 1H, diastereomers B), 3.32 (d, 1H, diastereomers A), 3.09 (m, 2H, both diastereomers), 2.80 (m, 2H, both diastereomers), 2.35 (m, 2H, both diastereomers), 1.98 (m, 2H, both diastereomers), 1.65-0.70 (m, 38H, both diastereomers), 0.55 (d, 3H, diastereomers B), 0.22 (d, 3H, diastereomers A); exo isomer, δ 7.5-7.1 (m, 18H, both diastereomers), 6.17 (m, 2H, both diastereomers), 5.90 (m, 2H, both diastereomers), 4.89 (q+q, 2H, both diastereomers), 4.55 (s, 2H, diastereomers A), 4.49 (d, 2H, diastereomers B), 3.59 (m, 2H, both diastereomers), 3.41 (d, 1H, diastereomers B), 3.29 (d, 1H, diastereomers A), 2.93 (m, 2H, both diastereomers), 2.80 (m, 2H, both diastereomers), 2.33 (m, 2H, both diastereomers), 1.80-0.70 (m, 40H, both diastereomers), 0.53 (d, 3H, diastereomers B), 0.21 (d, 3H, diastereomers A).
EXAMPLE 3
5-Norbornen-2-yl 2-bromo-2-methylpropionoate (Initiating Monomer 3) is synthesized according to the schematic below.
To a degassed solution of 5-norborne-2-ol (7.52 g, 68.2 mmol) and triethylamine (10.25 g, 101.3 mmol) in 400 mL THF a 2-bromoisobutyric bromide solution (20.62 g, 89.7 mmol in 50 mL THF) was added drop wise at 0° C. The reaction was left to warm slowly and stir at room temperature for 12 hrs. The reaction mixture was then filtered, and the solvent was removed in vacuo. The resultant residue was then redissolved in ether (300 mL) and washed with water (3×500 mL), saturated NaHCO 3 (300 mL), followed by water (500 mL). The organic layer was dried over anhydrous magnesium sulfate, and the solvents were evaporated giving 21.03 g of crude product. The product was then purified by column chromatography using EMD™ Silica Gel 60 as the stationary phase, eluting with 10:1 hexane/ethyl acetate to afford 15.9 g (90% yield) of pure product as a viscous, colorless oil. 1 H-NMR (200 MHz, CDCl3, 298 K): endo and exo isomers; δ 6.35 (m, 1H, endo), 6.28 (m, 1H, exo), 6.05-5.95 (m, 2H, endo and exo), 5.32 (m, 1H, endo), 4.73 (m, 1H exo), 3.21 (m, 1H, endo), 2.90 (m, 1H, exo), 2.93-2.83 (m, 2H, endo and exo), 2.16 (m, 1H, endo), 1.97-1.24 (m. 8H endo, 10H exo), −0.01 (m, 1H, endo).
EXAMPLE 4
Random copolymerization of ethylene with Initiating Monomer 2 is shown as a schematic below.
Random copolymerizations were conducted in the following manner. An autoclave reactor (100 mL) was loaded inside a glove box and charged with [N-(2,6-diisopropylphenyl)-2-(2,6-diisopropylphenylimino)propanamidato-κ 2 N,O](η 1 -benzyl)nickel(trimethyl phosphine) (15.8 mg, 25 μmol), bis(1,5-cyclooctadienyl)nickel (27.6 mg 100 μmol), and toluene, such that the final volume of the toluene solution was 30 mL. 2.02 g of a 50 wt % solution of Initiating Monomer 2 in toluene was added to the addition funnel, such that the initial concentration would be 0.075 M upon addition of Initiating Monomer 2. The reactor was sealed inside the glove box. The reactor was attached to an ethylene line and the gas was fed continuously into the reactor through the addition funnel at 50 psi. The pressurized reaction mixture was stirred at 20+/−2° C. After 30 minutes the ethylene was vented and methanol was added to quench the polymerization. The precipitated polymer was collected by filtration and dried overnight under vacuum to yield 1.82 g. Incorporation of Initiating Monomer 2 was found to be 6 mol % by 1H NMR (200 MHz, CDCl 3 , 25° C.) M n =27,402 g/mol, M w =47,508 g/mol, PDI=1.72 as calculated by Refractive Index GPC Analysis (o-dichlorobenzene, 135° C.) relative to polyethylene universal calibration from polystyrene standards.
EXAMPLE 5
Block copolymerizations of ethylene and Initiating Monomer 2 were performed accordingly to the scheme below.
An autoclave reactor (100 mL) was loaded inside a glovebox and charged with [N-(2,6-Diisopropylphenyl)-2-(2,6-diisopropylphenylimino)propanamidato-κ 2 N,O](η 1 -benzyl)nickel(trimethyl phosphine) (15.8 mg, 25 μmol), bis(1,5-cyclooctadienyl)nickel (27.6 mg 100 μmol), and toluene, such that the final volume of the toluene solution was 30 mL. 2.02 9 of a 50 wt % solution of Initiating Monomer 2 in toluene was added to the addition funnel, such that the initial concentration would be 0.075 M upon addition of Initiating Monomer 2. The reactor was sealed inside the glovebox. The reactor was attached to an ethylene line and the gas was fed continuously into the reactor at 100 psi while maintaining a constant temperature of 20+/−2° C. After 13 minutes, the ethylene was line was connected to the addition funnel and the pressure was ramped to 120 psi to begin a block of copolymer. After 2 minutes of copolymerization the ethylene was vented and methanol was added to quench the polymerization. The precipitated polymer was collected by filtration and dried overnight under vacuum to yield 2.50 g. Incorporation of Initiating Monomer 2 was under the detectable limit of 0.2 mol % by 1 H NMR (C 6 D 6 /1,2,4-trichlorobenzene, 115° C.) M n =56,754 g/mol, M w =90,169 g/mol, PDI=1.55 as calculated by Refractive Index GPC Analysis (o-dichlorobenzene, 135° C.) relative to polyethylene universal calibration from polystyrene standards. T m =127° C. as determined by DSC.
EXAMPLE 6
Grafting of poly(n-butylacrylate) chains to poly[ethylene-b-(ethylene-co-2) was performed accordingly to the schematic below.
A round bottom flask was charged with 150 mg of block copolymer, 2 mL unstabilized n-butyl acrylate, 20 mL decalin and degassed with argon for 20 minutes. Under an argon flow the contents of the round bottom were stirred and heated to 125° C. After 36 hours at 125° C. the contents of the flask were poured into a beaker containing 200 mL of methanol to precipitate the polymer. The polymer was collected on a filter paper and dried in vacuo at 50° C. Purification by Soxhlet extraction using dichloromethane as the extracting solvent removes the low molecular weight impurities from the polymer mixture leaving only high molecular weight polymer. T m =127° C. as determined by DSC.
Gel Permeation Chromatograph Overlay of Polymer from Example 5 and Polymer from Example 6 is shown in FIG. 4 . Example 5 (gray), M n =56,754 g/mol, M w =90,169 g/mol, PDI=1.55, and Example 6 (black), M n =77,025 g/mol, M w =138,749 g/mol, PDI=1.80 as calculated by Refractive Index GPC Analysis (o-dichlorobenzene, 135° C.) relative to polyethylene universal calibration from polystyrene standards.
REFERENCES
The following publications are hereby incorporated by reference:
1. Chung, T. C. Prog. Polym. Sci. 2002, 27, 39
2. Ittel, S. D.; Johnson, L. K.; Brookhart, M. Chem. Rev. 2000, 100, 1169
3. Bazan, G. C.; Ghosh, P.; Shimizu, F. U.S. Pat. No. 4,024,149, Feb. 28, 2003
4. Yasuda, H.; Ihara, E.; Morimoto, M.; Yamashita, M.; Nodono, M.; Yoshioka, S. Polymer Preprints 1994, 35, 532
5. Lee, B. Y.; Bazan, G. C.; Vela, J.; Komon, Z. J. A.; Bu, X. J. Am. Chem. Soc. 2001, 123, 5352.
6. Schunn, R. A.; Ittel, S. D.; Cushing, M. A. Inorg. Synth. 1990, 28, 94.
7. Bothe, M.; Schmidt-Naake, G. Macromol. Rapid Commun. 2003, 24, 609
Although the present invention has been described in connection with the preferred embodiments, it is to be understood that modifications and variations may be utilized without departing from the principles and scope of the invention, as those skilled in the art will readily understand. Accordingly, such modifications may be practiced within the scope of the following claims. | Described are novel monomers bearing functionalities capable of initiating control free radical reactions, and a novel process using these initiating monomers in the co-polymerization of an olefin for the formation of well-controlled polyethylene graft polymers where the graft component is derived from controlled free radical polymerization reactions. The initiating monomers are produced by combining an amount of 5-norbornen-2-ol with a hydride or amine for a predetermined amount of time to form a mixture; and adding an amount of an alkyl or acyl halide to said mixture. Polymerization of an olefin with an initiating monomer is conducted in the presence of a metal compound, where the metal compound is comprised of a Group VIII transition metal complex. | 2 |
BACKGROUND
[0001] 1. Field of the Invention
[0002] The invention relates to a shift report generation system. Specifically, the embodiments of the invention relate to a shift reporting system that tracks and corrects late production confirmation data.
[0003] 2. Background
[0004] Shift reports are utilized by shift supervisors to monitor the production of the workers during a particular shift. Unfortunately, employees often do not record their production information in a production tracking system before a shift ends or before a shift report is generated. For example, machine shop operators on a shop floor do not always have time to record their production into a production tracking system prior to the end of their shift. These production information entries, referred to as production confirmation entries, are often created after the end of the shift. This creates problems for supervisors seeking to review worker productivity for a shift.
[0005] The shift supervisor generates a shift report at the end of the shift, which is prior to the entry of these late production confirmation entries into the production tracking system. The shift report will not reflect the production of each of the individual workers on the shift, because this information is not yet available. Further complications in the analysis of productivity occur when later shift reports are generated. These later shift reports incorporate the late filed production confirmation entries and count them towards a following shift. Other issues can include the double inclusion of production confirmation entries in multiple shift reports, because the production confirmation entries indicate that the production occurred in an earlier shift, but the production confirmation entries themselves were not entered into the production tracking system until a later shift. If shift reports for a shift period during which production was completed and a subsequent shift period during which the production confirmation was entered are run at a time after the production confirmation entry is received, then both shift reports may include the production confirmation entries thereby skewing the production analysis in the shift reports. This makes it difficult for shift supervisors to accurately identify and review the productivity of the workers on their shift and can improperly affect the reviews of workers and shift supervisors by misplacing the actual production and productivity of workers into later shifts, thereby giving undue credit to later shifts.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Embodiments of the invention are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that different references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one.
[0007] FIG. 1 is a block diagram of one embodiment of a shift report generation system.
[0008] FIG. 2 is a diagram of an example set of production confirmation entries over the timeline of a set of shifts.
[0009] FIG. 3 is a flowchart of one embodiment of a process for generating a shift report using a simple listing.
[0010] FIG. 4 is a flowchart of one embodiment of a process for generating a shift report with a listing that avoids redundant listing of confirmations.
DETAILED DESCRIPTION
[0011] FIG. 1 is a diagram of one embodiment of a shift report generation system. In one embodiment, the shift report generation system can be incorporated into an enterprise resource planning (ERP) system 101 and/or a production planning system 103 . In another embodiment, a shift report generation module 105 is a stand-alone module or a module that is incorporated into other types of software applications. These and other components together create a production tracking system for tracking worker production and for creating shift reports to review worker production.
[0012] The shift report module 105 interacts with a production confirmation module 107 . The production confirmation module 107 gathers production confirmation entries or similar data structures from a set of input sources, such as manufacturing execution systems 111 , manual input sources 115 , automated sources 117 , and similar production confirmation sources. A ‘set,’ as used herein, refers to any positive whole number of items including one item. Production confirmation entries are data structures that store product production information such as the time that production completes (i.e. the time that a worker completes the last product for the shift, referred to herein as the ‘production endpoint’), the time that execution completes (i.e., the time that a worker completes all activities for a shift, referred to herein as the ‘execution endpoint’), the confirmation completion time (i.e., the time that a worker enters the production information into the production tracking system, referred to herein as the ‘creation point’), numbers of products produced, types of products produced and similar information. The products that are tracked can be any type of manufactured products, produced documents, or similar work product.
[0013] The shift report generation module 105 , as well as, the production planning module 103 and ERP system 101 can be executed by a computer system, such as a desktop computer system, laptop computer system, server or similar computing device. In another embodiment, the execution of these systems and modules is distributed over a set of computing devices. Production confirmation entries can be stored in a database that is connected to the production planning system 103 or ERP system 101 . The production confirmation database can be provided by a database management system that is executed by the same computing device that executes the shift report generation module 105 or other components of the product tracking system.
[0014] In one embodiment, production confirmation entries can be received from an automated source 117 . Automated sources 117 can include computing devices or simple sensor devices that monitor the condition of production machines, other computing devices, and similar resources to monitor the progress of a worker in the production of a product without the worker having to specifically input information about the progress of the production of the product. The automation of production confirmation entry generation can be partial or whole. Any field or aspect of production confirmation entries can be provided by a single sensor or automated source or a set of sensors or similar automated sources.
[0015] Production confirmation entries can also come from manual input sources 115 . Manual input sources 115 can be computer devices, worksheets, punch cards or other forms of data collection that are filled out or utilized by a worker to record product production. If these manual input sources 115 are forms or worksheets or similar sources, then they can be entered into the product tracking system to be provided to the production confirmation module 107 by manual data entry, scanning or similar processes.
[0016] In one embodiment, production confirmation entries come from a manufacturing execution system 111 . Manufacturing execution systems 111 are the production tracking systems of other entities, such as other warehouses, production facilities, or similar locations. These manufacturing cites may receive production orders 109 that they then complete. These manufacturing cites then provide these products to the local site where the shift report generation module 105 is being utilized or the location associated with the shift report generation module 105 . The production input from these manufacturing execution system 111 sources can be incorporated into shift reports. For example, using production information received from manufacturing execution system 111 sources may allow the supervisor to compare the amount of incoming product to the output of the workers on his shift. Manufacturing executing systems 111 may also incorporate other production information sources 113 further up the chain of production in a supply chain or from similar sources.
[0017] FIG. 2 is a diagram of one embodiment of a timeline of a shift schedule with a set of production confirmation entries that have been entered over a set of shifts. The shifts are delineated with a shift number appearing at the beginning of the shift. Specifically, shift one is S 1 , shift two is S 2 , shift three is S 3 , and shift four is S 4 . Each shift defines a data entry period (DEP) 201 . Shift one has a data entry period DEP 1 , while shifts two, three, and four have data entry periods DEP 2 , DEP 3 , and DEP 4 , respectively. The data entry periods are the periods during which a production confirmation entry can be received and counted into the shift such that it will be ensured of being included in the shift report. The correspondence of a production confirmation entry to a data entry period or a shift can be based on different data fields in the production confirmation entry. Production confirmation entries can include a processing finish date or time (i.e., the production endpoint), an execution finish date and time (i.e., the execution endpoint), and a production confirmation entry date and time (i.e., the creation point), amongst other data fields. These are represented in the diagrams by P, E and C, respectively.
[0018] The diagram of FIG. 2 shows an example set of production confirmation entries. The first production confirmation 203 defines a production endpoint (P) that occurs during data entry period DEP 2 , but an execution endpoint (E) and creation point (C) that occurred during data entry period DEP 3 . Thus, a shift report that is generated to include each production confirmation entry based on production endpoints falling within a data entry period of a selected shift would count this production confirmation entry 203 only in shift 2 . However, a shift report generation module that pulled all production confirmation entries with any value (P, E or C) that occurred during a shift would generate a shift report for shift 2 and a shift report for shift 3 that would both include this production confirmation entry 203 .
[0019] The next production confirmation entry 205 includes an execution endpoint (E) that occurs in shift 2 , but the creation point (C) is entered in shift 3 . In some instances, the production endpoint (P) is not entered. Production endpoint (P) denotes the time at which the actual production process in which a worker is engaged ends. In contrast, the execution endpoint (E) may include additional time that the worker spends on his job, but does not result in any additional production. For example, often machines need to be cleaned or otherwise maintained at the end of a production operation, prior to the next production operation beginning. This time is included in the time leading up to the execution endpoint, but during this time no additional production has been generated.
[0020] Production confirmation entry 207 falls entirely within shift 2 . Production confirmation entry 209 is similar to that of production confirmation entry 203 in that the production endpoint (P) occurs in a proceeding shift, in this case shift 1 , while the creation point (C) is actually within shift 2 . The final example production confirmation entry 211 spans three shifts where the production endpoint (P) occurs during shift 1 , execution endpoint (E) occurs during shift 2 , and the creation point (C) is not entered until shift 3 . These varying production confirmation entry timelines give a sense of the complexity of the task of generating accurate shift reports.
[0021] FIG. 3 is a flowchart of one embodiment of a process for generating a shift report using a simple listing. The process is initiated in response to a shift supervisor or similar user requesting that a shift report for a designated shift be generated using the shift report generation module. The shift report generation module filters the received or stored production confirmation data entries for those that fall within the selected shift period (block 301 ). The filtering can be based on any of the dates or fields of the production confirmation entry, including the production endpoint, execution endpoint, or the production confirmation entry creation point. The process then begins iterating through those production confirmation entries that remain after the filtering process has completed (block 303 ). The production confirmation entries are compiled into a list or similar data structure. A first entry in the list is selected for analysis. The process iterates through each production confirmation entry in the list.
[0022] The production endpoint is then checked for the currently selected entry (block 305 ). If the production endpoint is defined (e.g., it is not null or zero), then this date/time will be utilized for determining the proper shift report in which to place the corresponding production confirmation entry. If the production endpoint has been defined, then a temporary value is set equal to that production endpoint value (block 309 ). If the production endpoint value has not been defined, then the execution endpoint date/time will be utilized to place the production confirmation entry into the appropriate shift report. In this case the temporary value is set to be equal to the execution endpoint value.
[0023] The temporary value is compared to the shift period (block 311 ). If the temporary value falls within the shift period, then the currently selected production confirmation entry is added to the shift report for the selected shift period that is being generated (block 319 ). However, if the temporary value does not fall within the selected shift period, then a check is made to determine whether the production confirmation entry was completed (i.e., entered into the production tracking system) within the selected shift period (block 313 ). If the production confirmation entry was completed during the shift period, this would indicate that it was not part of a previous shift report or, if it was, it would be redundant to place it into both shift reports. Thus, the production confirmation entry is added to the shift report that is currently being generated, but the entry is flagged to indicate that it has been incorporated into a shift report. In subsequently generated shift reports, the flagging can help the reviewer to recognize that the data may be redundant or misplaced (block 317 ). If the production confirmation entry was not generated within the selected shift period, then this production confirmation entry is discarded for purposes of creating the current shift report (block 315 ).
[0024] After the decision regarding the addition of the production confirmation entry to the shift report has been completed (blocks 315 , 317 , and 319 ), then the next production confirmation entry in the list is selected for analysis. This process continues until all the production confirmation entries in the list generated after the filtering have been exhausted.
[0025] FIG. 4 is a flowchart of one embodiment of a process for generating a shift report using a listing that avoids redundant listing of confirmations. In one embodiment, the process is initiated in response to the user selecting a specific shift period for a shift report to be generated. The process then begins by filtering the production confirmation data entries to find those that are related to the shift report period that has been selected (block 401 ). The filtering may find all of the production confirmation data entries that have a production endpoint, execution endpoint or creation point that falls within the shift report.
[0026] The process continues by selecting a first production confirmation entry from the list of filtered entries (block 403 ). This production confirmation entry is analyzed to determine whether the production endpoint value has been defined (i.e., it is not a null or zero value) (block 405 ). The production endpoint value, if defined, is utilized for the sorting of the production confirmation entry into the proper shift report. If the production endpoint value has been defined, then a temporary value is set to that production endpoint value (block 407 ). However, if this production endpoint value has not been defined, then the temporary value that is utilized for sorting the production confirmation entry is the execution endpoint value (block 409 ). In this scenario, the execution endpoint date/time is utilized in place of the production endpoint date/time. The temporary value is set to the execution endpoint value in this scenario.
[0027] After the temporary value has been set, the temporary value is checked to see whether it falls within the selected shift period (block 413 ). If the temporary value is within the selected shift period, then the currently selected production confirmation entry is added to the shift report (block 417 ). The process then continues on to analyze the next production confirmation entry in the list (block 403 ).
[0028] If the temporary value does not fall within the shift period, then the creation point is checked to determine whether it falls within the shift period that is currently selected (block 411 ). If the creation point does not fall within the selected shift period, then this production confirmation entry is discarded (block 415 ). The process then continues on to analyze the next production confirmation entry in the list (block 403 ).
[0029] If the creation point does fall within the shift period, then the shift report that covers the shift period for the temporary value is determined (block 419 ). This would be a shift report period that proceeds the currently selected period either immediately or any number of shift periods earlier. A check is then made to determine whether the shift report for the period that is determined to correspond to the temporary value was created before the confirmation of the currently selected production confirmation entry (block 421 ). If the shift report that corresponds to the temporary value was created after the production confirmation entry date, then presumably the production confirmation entry is already a part of that shift report and nothing needs to be done with it at this time and it is discarded for purposes of generating the current shift report (block 425 ). The process then continues on to analyze the next production confirmation entry in the list (block 403 ). However, if the shift report had been created before the confirmation date, then the production confirmation entry is added to the current shift report and flagged to indicate that it does not properly belong in the current shift report, but that it had not been included in the proper shift report (block 423 ). This ensures that every production confirmation entry is placed into a report and guarantees that there are not redundancies in the shift reports that are not, at the very least, flagged to provide notice to the reviewer.
[0030] In one embodiment, the production tracking system including the shift report generation module may be implemented as hardware devices. In another embodiment, these components may be implemented in software (e.g., microcode, assembly language or higher level languages). These software implementations may be stored on a computer-readable medium. A “computer-readable” medium may include any medium that can store or transfer information. Examples of a computer-readable medium include a ROM, a floppy diskette, a CD-ROM, a DVD, flash memory, hard drive, an optical disk or similar medium.
[0031] In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes can be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. | The embodiments of the present invention provide a shift report module that improves the accuracy of the information within the shift report by flagging or avoiding redundant entries between shift reports and ensuring that entries are not lost between shift reports based on the time that they were entered and the time that the shift reports were generated. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to hydraulic systems for vehicles and, more particularly, to a combination braking and traction control system adapted for use in motor vehicle driveline applications.
BACKGROUND OF THE INVENTION
[0002] In view of an increased demand for vehicles having anti-lock braking systems and traction control systems, many controls are currently being incorporated in vehicular driveline applications for transferring braking torque and/or drive torque to the wheels. A modern trend in vehicle design includes equipping a driveline with a transfer case having an electronically controlled transfer clutch. The transfer clutch is operable to automatically direct drive torque to the primary and/or secondary drivelines without any input or action on the part of the vehicle operator. The transfer clutch is typically actuated by a power-operated clutch actuator which responds to control signals sent from a traction control module. The control signals are typically based on current operating conditions of the vehicle (i.e., vehicle speed, interaxle speed difference, acceleration, steering angle, etc.) as detected by various sensors. For example, if traction is lost at the primary wheels, the transfer clutch can be engaged to establish an “on-demand” four-wheel drive mode. Thus, such “on-demand” transfer cases can utilize adaptive control schemes for automatically controlling torque distribution during all types of driving and road conditions.
[0003] To assure vehicle stability is maintained during braking, many vehicles are also now equipped with an anti-lock braking system. The anti-lock braking system includes a hydraulic pressure source which supplies pressurized fluid to hydraulically-powered brake actuators for actuating the brakes located at each wheel end. The anti-lock braking system typically uses some or all of the sensor signals to control operation of the brake actuators. Specifically, a brake control mode receives sensor signals and functions to control coordinated actuation of the brakes. Typically, little to no interaction occurs between the control modules for the anti-lock braking system and the traction control system. However, some systems provide minimal communication to disable the traction control system so as to assure that the vehicle is not placed in a four-wheel drive mode when the anti-lock braking system is functioning.
[0004] While the present anti-lock braking systems and traction control systems have operated sufficiently in the past, a need exists to reduce the complexity and cost of implementing such systems on a motor vehicle. For example, the size, weight and electrical power requirements of electrical motors needed to provide the described clutch engagement loads may make such systems cost prohibitive.
SUMMARY OF THE INVENTION
[0005] Thus, it is an object of the present invention to provide a combination braking and traction control system having a source of pressurized fluid and an actuator adapted to selectively supply pressurized fluid to the vehicle wheel brakes and at least one transfer clutch. The transfer clutch is operable to selectively transfer drive torque from a first rotary member to a second rotary member. The anti-lock braking and traction control system also includes a controller in communication with the actuator to control the duration and magnitude of fluid pressure supplied to the wheel brakes and the transfer clutch.
[0006] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0008] FIG. 1 is a schematic illustration of a vehicle equipped with a combination braking and traction control system of the present invention;
[0009] FIG. 2 is a schematic illustration of a brake and AWD system of the present invention;
[0010] FIG. 3 is a cross-sectional side view of an exemplary transfer case selectively operable by the braking and traction control system of the present invention; and
[0011] FIG. 4 is a schematic illustration of a vehicle equipped with an alternate braking and traction control system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] The present invention is directed to a combination braking and traction control system for adaptively controlling the brakes of the vehicle as well as a mechanism that modulates the torque transferred from a first rotary member to a second rotary member. The torque transfer mechanism finds particular application in power transmission devices for use in motor vehicle drivelines such as, for example, an on-demand clutch in a transfer case or in-line torque coupling, a biasing clutch associated with a differential assembly in a transfer case or a drive axle assembly, or as a shift clutch in a multi-speed automatic transmission. Thus, while the present invention is hereinafter described in association with particular arrangements for use in specific driveline applications, it will be understood that the arrangements shown and described are merely intended to illustrate embodiments of the present invention.
[0013] With particular reference to FIG. 1 of the drawings, a drivetrain 10 for a four-wheel drive vehicle is shown. Drivetrain 10 includes a primary driveline 12 , a secondary driveline 14 , and a powertrain 16 for delivering rotary tractive power (i.e., drive torque) to the drivelines. In the particular arrangement shown, primary driveline 12 is the rear driveline while secondary driveline 14 is the front driveline. Powertrain 16 includes an engine 18 , a multi-speed transmission 20 , and a power transmission device, hereinafter referred to as transfer case 22 . Rear driveline 12 includes a pair of rear wheels 24 and 25 connected at opposite ends of a rear axle assembly 26 having a rear differential 28 coupled to one end of a rear prop shaft 30 , the opposite end of which is coupled to a rear output shaft 32 of transfer case 22 . Likewise, front driveline 14 includes a pair of front wheels 34 and 35 connected at opposite ends of a front axle assembly 36 having a front differential 38 coupled to one end of a front prop shaft 40 , the opposite end of which is coupled to a front output shaft 42 of transfer case 22 .
[0014] With continued reference to the drawings, drivetrain 10 is shown to further include an electronically-controlled brake and all wheel drive (AWD) system 44 for providing anti-locking braking functions as well as traction control functions. In this regard, driveline 10 is equipped with a pair of front brakes 46 and 48 for decelerating front wheels 34 and 35 as well as a pair of rear brakes 50 and 52 for decelerating rear wheels 24 and 25 . Each brake includes a hydraulically-powered brake operator for applying the brakes. Additionally, brake and AWD system 44 includes one or more clutches that may be selectively actuated for transferring drive torque from engine 18 to one or more of the wheels. In one example, a transfer clutch 66 is positioned within transfer case 22 and may be selectively operated to transfer drive torque from rear output shaft 32 to front output shaft 42 for establishing part-time and on-demand four-wheel drive modes. Furthermore, front axle assembly 36 may be equipped with a front axle biasing clutch 68 for selectively varying the torque distribution delivered from front prop shaft 40 to front wheels 34 and 35 . Similarly, rear axle assembly 26 may include a rear axle biasing clutch 70 for selectively varying the torque distribution delivered from rear prop shaft 30 to rear wheels 24 and 25 . It should be appreciated that a vehicle may be equipped with one or more of these torque transfer clutches without departing from the scope of the present invention. Preferably, each of these torque transfer clutches includes at least one multi-plate friction clutch assembly and, as will be detailed, a hydraulically-powered actuator for controlling engagement of the friction clutch assemblies.
[0015] Brake and AWD system 44 preferably includes a common brake/AWD system actuator assembly 54 . Pressurized hydraulic fluid is selectively supplied to each of the brake operators and/or the clutches by actuator assembly 54 . In operation, a hydraulic pump 56 is driven by a motor 58 to supply fluid to actuator assembly 54 and an accumulator 60 . Accumulator 60 stores pressurized fluid for use during peak demand situations. In addition vehicle sensors 62 detect certain dynamic and operational characteristics of the motor vehicle. Finally, a controller 64 controls the operation of components associated with actuator assembly 54 in response to signals provided by vehicle sensors 62 .
[0016] With reference to FIG. 2 , brake and AWD system actuator assembly 54 is shown to include a plurality of electro-hydraulic pressure modulators 72 that are each plumbed in fluid communication with pump 56 and accumulator 60 . Actuator assembly 54 also includes a plurality of pressure sensors 74 . Each pressure sensor 74 provides a signal to controller 64 that is indicative of the fluid pressure being supplied to the particular brake and/or clutch. Each brake and clutch may be individually controlled based on the current vehicle characteristics.
[0017] In the example depicted in FIG. 2 , a first fluid passageway 76 A interconnects the hydraulic brake operator 46 A associated with left front brake 46 to the high pressure fluid generated by pump 56 . A first pressure modulator 72 A is operable to controllably vary the fluid pressure supplied to brake operator 46 A for controlling engagement of left front brake 46 . Likewise, pressure sensor 74 A provides a signal to controller 64 that is indicative of the fluid pressure within passageway 76 A. Controller 64 is in communication with pressure modulator 78 and functions to controllably vary the fluid pressure within passageway 76 A. Preferably, first pressure modulator 72 A is an electro-hydraulic control valve capable of controlling the fluid pressure delivered to brake operator 46 A based on the value of an electric command signal generated by controller 64 .
[0018] Similarly, a second fluid passageway 76 B interconnects brake operator 48 A associated with right front brake 48 to the high fluid pressure generated by pump 56 . A second electro-hydraulic pressure modulator 72 B provides metered pressurized fluid to hydraulic brake operator 46 B for controlling engagement of right front brake 48 . A pressure sensor 74 B outputs a signal indicative of the fluid pressure within passageway 78 to controller 64 . With continued reference to FIG. 2 , a third passageway 76 C and a fourth passageway 76 D provide fluid communication between pump 56 and respective left and right rear brake operators 46 C and 46 D. Third and fourth electro-hydraulic pressure modulators 72 C and 72 D are provided to control the fluid pressure supplied to brake operators 46 C and 46 D, respectively. As seen, pressure sensors 74 C and 74 D are provided downstream of pressure modulators 72 C and 72 D to provide pressure signals to controller 64 . Finally, fifth passageway 76 E, sixth passageway 76 F and seventh passageway 76 G provide fluid communication between pump 56 and corresponding ones of clutch operators 66 A, 68 A and 70 A associated with transfer clutch 66 and axle biasing clutches 68 and 70 , respectively. Corresponding electro-hydraulic pressure modulators 72 E, 72 F ad 72 G and pressure sensors 74 E, 74 F and 74 G are provided in these passageways. Variable control of the hydraulic pressure supplied to each of the clutch operators function to control variable or “adaptive” engagement of each clutch.
[0019] The brake/AWD system depicted in FIG. 2 provides the greatest amount of vehicle control because each brake or clutch is equipped with a pressure modulator and sensor. One skilled in the art will appreciate that a simplified system having a reduced number of pressure modulators and sensors is also contemplated as being within the scope of the present invention. Specifically, left front brake 46 and right front brake 48 may be controlled with a single pressure modulator and pressure sensor.
[0020] FIG. 3 depicts an exemplary transfer case 22 equipped with transfer clutch 66 . Transfer case 22 is shown to include a multi-piece housing 85 from which rear output shaft 32 is rotatably supported. Rear output shaft 32 includes an internally-splined first end segment 86 adapted for connection to the output shaft of transmission 20 and a second end segment 87 to which a yoke 88 is secured for connection to rear prop shaft 30 . Front output shaft 42 is likewise rotatably supported in housing 85 and includes an integral yoke segment 89 adapted for connection to front prop shaft 40 .
[0021] Transfer clutch 66 is operably arranged to transfer rotary power (i.e., drive torque) from rear output shaft 32 to front output shaft 42 through a transfer assembly 90 . Transfer assembly 90 includes a first gear 92 , a second gear 94 , and a third gear 96 that is in meshed engagement with first gear 92 and second gear 94 . First gear 92 is shown to be rotatably supported on rear output shaft 32 via a bearing assembly 98 and likewise be rotatably supported from housing 85 via a pair of laterally spaced bearing assemblies 100 . Second gear 94 is coupled via a spline connection 102 to front output shaft 42 and is rotatably supported from housing 85 by a pair of laterally spaced bearing assemblies 104 . Finally, third gear 96 is rotatably supported by bearing assemblies 106 on a stub shaft 108 that is non-rotatably secured to housing 85 . It is contemplated that geared transfer assembly 90 could be replaced with a well-known chain and sprocket type transfer system if desired.
[0022] Transfer clutch 66 includes a multi-plate friction clutch assembly 110 and clutch operator 66 A, hereinafter referred to as clutch actuator assembly 112 . Clutch assembly 110 is shown to include a clutch drum 114 fixed via a spline connection 116 to a tubular segment 118 of first gear 92 , a clutch hub 120 fixed via a spline connection 122 to rear output shaft 32 , and a multi-plate clutch pack 124 operably disposed between drum 114 and hub 120 . Clutch pack 124 includes a set of outer clutch plates that are splined for rotation with and axial movement on an outer cylindrical rim segment 126 of drum 114 . Clutch pack 124 also includes a set of inner clutch plates that are splined for rotation with and axial movement on clutch hub 120 . Clutch assembly 110 further includes an apply plate 128 splined for rotation with rim segment 126 of drum 114 , and a pressure plate 132 splined to a fixed support 134 . A thrust bearing 135 is provided between apply plate 128 and pressure plate 132 to accommodate relative rotation therebetween during concurrent axial movement. Clutch actuator assembly 112 includes a piston 136 positioned within a pressure chamber 138 formed in support 134 . A passageway 140 extends through support 134 and housing 85 to allow pressurized fluid supplied from pressure modulator 72 E to enter chamber 138 and act on piston 136 . Apply plate 128 is arranged to exert a compressive clutch engagement force on clutch pack 124 in response to translational movement of pressure plate 132 and piston 136 .
[0023] Apply plate 128 is axially moveable relative to clutch pack 124 between a first or “released” position and a second or “locked” position. With apply plate 128 in its released position, a minimum clutch engagement force is exerted on clutch pack 124 such that virtually no drive torque is transferred from rear output shaft 32 through clutch assembly 110 and transfer assembly 90 to front output shaft 42 so as to establish the two-wheel drive mode. In contrast, location of apply plate 128 in its locked position causes a maximum clutch engagement force to be applied to clutch pack 124 such that front output shaft 42 is, in effect, coupled for common rotation with rear output shaft 32 so as to establish the part-time four-wheel drive mode. Therefore, accurate control of the position of apply plate 128 between its released and locked positions permits adaptive regulation of the amount of drive torque transferred from rear output shaft 32 to front output shaft 42 , thereby establishing the on-demand four-wheel drive mode.
[0024] FIG. 1 illustrates vehicle sensors 62 grouped together in a block format. However, it is contemplated that the sensors required for controlling the combination brake and traction control system includes individual wheel speed sensors 62 A through 62 D, engine speed sensor 62 E and transmission gear sensor 62 F. Obviously, such sensors are used in virtually all conventional vehicles such that the present invention can be easily incorporated into vehicles utilizing an ABS arrangement.
[0025] FIG. 4 depicts an alternate embodiment brake and AWD system 200 . System 200 is substantially similar to system 44 except that system 200 includes a brake system actuator 202 that is plumbed to a brake supply circuit 204 and an AWD actuator 206 that is plumbed to a separate AWD supply circuit 208 . Due to the substantial similarity between brake and AWD system 44 and system 200 , common elements will retain their previously introduced reference numerals.
[0026] One skilled in the art will appreciate that brake system actuator 202 and AWD actuator 206 are both controlled by controller 64 . Preferably, controller 64 is the main vehicle controller. However, controller 64 may be separate from and in addition to a main vehicle controller.
[0027] Brake supply circuit 204 includes a motor 210 drive a pump 212 . The output from pump 212 supplies an accumulator 214 and brake system actuator 202 . Accumulator 214 functions to provide pressurized fluid to brake system actuator 202 if pump 212 is unable to provide the requested demand. Brake system actuator 202 is substantially similar to the brake and AWD actuator previously described. As such, brake system actuator 202 selectively supplies pressurized fluid to each of the hydraulically-powered brake operators to control engagement of the wheel brakes based on signals provided by controller 64 .
[0028] AWD supply circuit 208 includes a motor 216 driving a pump 218 . The output from pump 218 supplies an accumulator 220 as well as AWD actuator 206 . AWD actuator 206 selectively provides pressurized fluid to transfer clutch 66 , front axle clutch 68 and/or rear axle clutch 70 . As previously mentioned, the number and location of clutches implemented within the vehicle at FIG. 4 is merely exemplary and that virtually any number of clutches may be selectively controlled by AWD actuator 206 .
[0029] Based on the description of brake and AWD system 200 previously provided, one skilled in the art will appreciate that brake system actuator 202 and AWD actuator 206 may be controlled to operate simultaneously, alternately or entirely independently from one another. Separate supply circuits 204 and 208 provide further support for independent control of brake system actuator 202 and AWD actuator 206 . However, a single supply circuit may be used to provide fluid to both brake system actuator 202 and AWD actuator 206 without departing from the scope of the present invention. Depending on the volume requirements of brake system actuator and AWD actuator 206 , it may be more efficient to construct a single slightly larger supply circuit than two individual smaller supply circuits.
[0030] Furthermore, the foregoing discussion discloses and describes merely exemplary embodiments of the present invention. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims, that various changes, modifications and variations may be made therein without department from the spirit and scope of the invention as defined in the following claims. | An anti-lock braking and traction control system includes a sources of pressurized fluid, an actuator adapted to selectively supply the pressurized fluid to wheel brakes and a clutch. A controller communicates with the actuator to control the duration of magnitude of pressure supplied to the wheel brakes and the clutch. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 12/434,688 filed May 4, 2009.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to semiconductor technology and, more particularly, to a semiconductor structure, e.g. a metal gate or a word line of a vertical-channel transistor, and a method for making the same.
2. Description of the Prior Art
As circuit integration increases, the need for greater uniformity and process control regarding layer thickness rises. Various technologies have been developed to deposit layers on substrates in a cost-effective manner, while maintaining control over the characteristics of the layer.
Selective deposition methods such as selective chemical vapor deposition (CVD) processes are known in the art. Selective deposition may be used to deposit materials on selected surfaces of structures in the manufacture of integrated circuits, and thus obviates the need for associated lithography, etching, and resist removal steps. Selective CVD processes are advantageous because they allow for self-alignment with respect to various structures, thus allowing for relatively tight design rules.
However, the prior art selective deposition methods still have some drawbacks. For example, the prior art selective deposition methods are often used to grow tungsten layer in a contact hole. Prior to the deposition or growth of the tungsten in the contact hole, a series of cleaning steps are required to ensure the silicon surface cleanness. If Reactive Ion Etching (RIE) damage layer exists on the bottom of the contact hole, the metal film formed by the selective CVD process does not grow because the RIE damage layer may work as an insulating film. Therefore, the RIE damage layer needs to be removed before growth of the metal film.
In addition, the prior art selective deposition methods are apparently not able to provide a selectively deposited layer such as tungsten layer, which is not only a conformal, ultra-thin (below 15 nm) film but structurally continuous, on a metallic, non-silicon base layer. Also, it is difficult to maintain sufficiently high selectivity between dielectric layer and metal base layer and to deposit such conformal, ultra-thin film at the same time.
In light of the above, there is a need in this industry to provide an improved semiconductor structure and method for making the same, where a conformal, ultra-thin film is desired and the conformal, ultra-thin film can be selectively deposited on a metallic, non-silicon base layer with high selectivity between dielectric layer and metal base layer. It is also desirable to provide a method for making such conformal, ultra-thin film with higher throughput.
SUMMARY OF THE INVENTION
It is one objective of this invention to provide an improved semiconductor structure, e.g. a metal gate or a word line of a vertical-channel transistor, and a method for making the same in order to solve the above-mentioned prior art problems.
According to one aspect of this invention, a semiconductor structure is provided. The semiconductor structure includes a substrate; a dielectric layer overlying the substrate; a conductor pattern on a main surface of the dielectric layer, the conductor pattern having a top surface and sidewalls; and a conformal metal layer selectively deposited on the top surface and sidewalls, but without deposited on the main surface of the dielectric layer substantially.
According to another aspect of this invention, a method for forming a semiconductor structure is provided. The method includes providing a substrate; forming a dielectric layer on the substrate; forming a conductor pattern on a main surface of the dielectric layer, the conductor pattern having a top surface and sidewalls; and performing a selective atomic layer deposition (ALD) process to selectively deposit a conformal metal layer onto the top surface and sidewalls of the conductor pattern, but without depositing onto the main surface of the dielectric layer substantially.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic, cross-sectional diagram illustrating a semiconductor structure of an integrated circuit in accordance with one preferred embodiment of this invention.
FIG. 2 is a flow diagram of a method for making a semiconductor structure of FIG. 1 in accordance with the preferred embodiment of this invention.
DETAILED DESCRIPTION
FIG. 1 is a schematic, cross-sectional diagram illustrating a semiconductor structure of an integrated circuit in accordance with one preferred embodiment of this invention. As shown in FIG. 1 , the semiconductor structure 1 comprises a semiconductor substrate 10 such as silicon substrate, a dielectric layer 12 on the semiconductor substrate 10 , a conductor pattern 14 formed on a main surface 12 a of the dielectric layer 12 , and an ultra-thin metal layer 16 selectively deposited on a top surface 14 a and sidewalls 14 b of the conductor pattern 14 . Substantially, the metal layer 16 is not deposited or grown directly on the main surface 12 a of the dielectric layer 12 .
According to this invention, the semiconductor structure 1 may be a metal-gated transistor device and the dielectric layer 12 is a gate dielectric layer or gate oxide layer of the metal-gated transistor device. This invention is particularly suited for a metal-gated vertical-channel transistor device. Such vertical-channel transistor device may be used in advanced dynamic random access memory (DRAM) technology, wherein the metal layer 16 is capable of reducing the resistance of the word lines. Further, it is often required that the metal layer 16 is ultra thin (below 15 nm) and is a continuous and conformal layer for the concern of work function of the metal-gated transistor device.
In accordance with the preferred embodiment of this invention, the dielectric layer 12 comprises silicon oxide, silicon nitride or silicon oxy-nitride. The conductor pattern 14 comprises titanium, titanium nitride, tantalum, tantalum nitride, aluminum, copper, gold, tungsten, silicide or any combination thereof. Preferably, the conductor pattern 14 is made of titanium nitride and the metal layer 16 is an atomic layer deposited tungsten layer having a thickness of less than 15 nanometers. Preferably, the conductor pattern 14 , which may be part of a metal gate or word line, has a thickness of less than 15 nanometers, more preferably, in a range of about 6-8 nanometers.
Please refer to FIG. 2 . FIG. 2 is a flow diagram of a method 20 for making a semiconductor structure of FIG. 1 in accordance with the preferred embodiment of this invention. As shown in FIG. 2 , in Step 21 , a semiconductor substrate such as the substrate 10 depicted in FIG. 1 is provided. In Step 22 , a dielectric layer such as the dielectric layer 12 depicted in FIG. 1 is thermally grown on the semiconductor substrate. The dielectric layer comprises silicon oxide, silicon nitride or silicon oxy-nitride.
In Step 23 , a metal pattern such as the conductor pattern 14 depicted in FIG. 1 is formed on the main surface of the dielectric layer. The metal pattern comprises titanium, titanium nitride, tantalum, tantalum nitride, aluminum, copper, gold, tungsten, silicide or any combination thereof. Preferably, the metal pattern is titanium nitride and the metal pattern is defined by wet etching methods. For example, a metal layer such as a titanium nitride layer is capped with a mask layer such as a polysilicon layer. The mask layer only mask a top surface of the metal layer but exposes sidewalls of the metal layer. A wet etching process is then carried out to etch the sidewalls of the metal layer to define the metal pattern. The mask layer is then removed to expose the top surface of the metal pattern.
After the formation of the metal pattern, a selective tungsten atomic layer deposition process is carried out to grow a conformal, ultra-thin tungsten layer such as the metal layer 16 depicted in FIG. 1 on the metal pattern. According to this invention, the conformal, ultra-thin tungsten layer has a thickness of less than 15 nm and has good step coverage characteristic. The selective tungsten atomic layer deposition process may involve a plurality of ALD cycles to achieve a desired thickness of the tungsten layer on the metal pattern. For the sake of simplicity, merely one of the ALD cycles (Steps 24 - 27 ) is illustrated in the flow diagram in FIG. 2 .
According to the preferred embodiment of this invention, the ALD cycle includes: (1) flowing hydrogen-containing substance such as silane or hydrogen gas into a chamber for a period of time to adsorb hydrogen radicals on the main surface of the dielectric layer and on the metal pattern (Step 24 ); (2) pumping down the chamber while stopping all gas flow to selectively remove the hydrogen radicals merely from the main surface of the dielectric layer (Step 25 ); (3) flowing tungsten precursor such as tungsten hexafluoride (WF 6 ) into the chamber at a low pressure (below 5 torr) and low temperature (below 300° C.) to react with the remanent hydrogen radicals adsorbed merely on the metal pattern, thereby selectively depositing a tungsten layer thereto (Step 26 ); and (4) purging the chamber with inert gas such as argon to remove by-products (Step 27 ). It is understood that the desired thickness of the tungsten layer can be achieved by repeating the ALD cycle (Step 28 ).
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims. | A method for forming a semiconductor structure is provided. The method includes providing a substrate; forming a dielectric layer on the substrate; forming a conductor pattern on a main surface of the dielectric layer, the conductor pattern having a top surface and sidewalls; and performing a selective atomic layer deposition (ALD) process to selectively deposit a conformal metal layer onto the top surface and sidewalls of the conductor pattern, but without depositing onto the main surface of the dielectric layer substantially. | 7 |
RELATED APPLICATION
[0001] The invention claims priority from Provisional Application Serial No. 60/281,531, filed on Apr. 3, 2001.
BACKGROUND OF INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to carboline derivatives. In particular the present invention relates to 1-substituted 1,2,3,4-tetrahydro-β-carboline and 3,4-dihydro-β-carboline derivatives which may have useful therapeutic activity, particularly anti-mitotic activity. The present invention also relates to the use of these compounds in therapy and to compositions containing them.
[0004] 2. Background Art
[0005] Despite the increasing research efforts directed towards their treatment and cure, cancerous conditions remain one of the major causes of human mortality. Current clinical treatments include radiation or chemotherapy, or combinations of both. However, in many cases chemotherapy plays a vital role in cancer treatment. The development of various chemotherapeutic drugs which are presently in clinical use has generally been on the characterization of the proliferative cancer cells. The effect of these drugs is to inhibit proliferation of the cancer cells. The chemotherapeutic drugs which are currently used in clinics can be classified into five groups according to their mechanisms of action. They are: (1) alkylating agents, (2) antimetabolites, (3) antibiotics, (4) steroids, and (5) plant alkaloids. The effect of first four groups is considered to occur at the DNA level. The effect of the last group, plant alkaloids, is considered to occur at protein level. During cell proliferation, the chromosome segregation is towed by the mitotic spindle. Therefore, disrupting the formation of the mitotic spindle, can inhibit cell proliferation. Compounds which inhibit cell proliferation by disrupting the formation of the mitotic spindle are called antimitotic agents.
[0006] The mitotic spindle is a microtubule-based structure and a cytoskeleton protein. In addition to forming the spindle fibre at mitosis, the mitotic spindle is also involved in intracellular transport, motility architecture (Dumontet, C. et al, J. Clin. Oncol., 17(3), 1061-1070, 1999 and Alberts, B., et al, Molecular Biology of the Cell, 3 rd “Edition, 807-813, 1994). Microtubules are composed of α, β, tubulin dimer and microtubule associated proteins. The microtubule structure is a dynamic structure with a rapid turnover rate, its half-life being only about 10 minutes. The polymer and tubulin dimer are always in an unstable equilibrium with polymerisation and depolymerisation of microtubules continually and dynamically taking place. The process must go through a course of nucleation, when the tubulin dimer polymerises into a microtubule. In most cells the centrosome is the center of microtubule organizations. After nucleation, polymerisation (lengthening) starts along the cellular periphery. Depolymerisation (shortening) will then occur shortly after polymerisation (it shrinkages back to centrosome). This can result in partial depolymerisation of microtubules that revert to a polymerisation status or the disappearance and replacement with a new microtubule. The process of alternate polymerisation and depolymerisation is called dynamic instability, and this plays an important role in microtubule function. For instance, some proteins inhibit dynamic instability of microtubules thereby inhibiting depolymerisation when cells differentiate into certain morphologies. Mitosis and cytokinesis of normal cells also depend on dynamic instability. Both of rates of polymerisation and depolymerisation of microtubules accelerate at M phase. During mitosis, microtubules rapidly assemble the mitotic spindle. The mitotic spindles subsequently disassembles along the pores of spindle to complete mitosis. Thus, disruption of the dynamic instability of the microtubules, call prevent mitosis and cellular proliferation. The new direction for cancer treatment research is to find new drugs that disrupt the dynamic instability of microtubules.
[0007] At present, the antimitotic agents used in the clinic include colchicine, vinca alkaloids and taxol. All of these are natural products. Colchicine and vinca alkaloids can stimulate microtubule depolymerisation. However, the cytotoxicity of colchicine towards healthy cells restricted its development as a widespread therapeutic and its current use is in the treatment of gout. Taxol also disrupts the dynamic instability of the microtubular structure but acts in an opposite manner to colchicine by stimulating tubulin polymerisation and stabilizing microtubules. Many of the antimitotic agents currently under investigation, such as combratastatins, curacins, dolastatin 10, 15, cryptophycins, exhibit antiproliferative mechanisms similar to colchicine or vinca alkaloids. A few, such as discodermolide, epothilones, eleutherobin and laulimalides, exhibit taxol-like effects.
[0008] Marine natural products which contain a β-carboline skeleton are widely distributed in marine invertebrates (Blackman, A. J., et al, J Nat. Prod., 1987, 50, 494; Kearns, P. S., et al, J Nat. Prod., 1995, 58, 1075; Kobatashi, J., J Nat. Prod., 1994, 57, 1737). A number of these have been shown to exhibit antitumor and antiviral activity. Particularly interesting compounds include the eudistomins (Badre, A., et al, J Nat. Prod., 1994, 57, 528 and Rinehart Jr, K. L., et al, J Am., Chem. Soc., 1987, 109, 3378) and manzamines (Crews, P., et al, Tetrahedron, 1994, 50, 13567 and Sakai, R., et al Tetrahedron, 1987, 28, 5493) which were isolated from marine tunicates and sponges, respectively. As a class, the oxathiazepine containing eudistomines exhibited potent inhibitory activity toward DNA virus HSV-1. In addition, the antiviral eudistomines C (1) and E (2) were also found active against HSV-2, the Vaccinia virus and RNA viruses. The novel structures of manzamines, however, were reported to possess potent antitumor activity (Ichiba, T., et al, Tetrahedron Lett., 1988, 29, 3083 and Higa, T., Studies in Natural Product Chemistry , Vol. 5, Part B, Elsevier Co., New York, 1989, pp346-353). The most active was manzamine A (3), a principal metabolite from several species of sponges, which showed cytotoxicity against murine P-388 cells at 0.07 μg/ml (Sakai, R., et al, J Am. Chem., Soc., 1986, 108, 6404).
[0009] 1-Substituted 1,2,3,4-tetrahydro-β-carboline and 3,4-dlhydro-β-carboline derivatives have now been prepared and have been shown to exhibit biological activity.
[0010] These compounds may, therefore, be useful in the treatment of cancerous conditions.
SUMMARY OF INVENTION
[0011] Throughout the specification and the claims which follow, the word “comprise,” and variations such as “comprises” and “comprising,” will be understood to imply the inclusion of a stated integer, element, or step, or group of integers, elements, or steps, but not the exclusion of any other integer, element, or step, or group of integers, elements, or steps.
[0012] In a first aspect, the present invention provides a compound of formula (I).
[0013] wherein is an optional double bond, Y comprises one selected from hydroxy, C 1-6 alkoxy, benzyloxy, C 1-6 acyloxy, amino, C 1-6 alkyl, C 1-6 dialkylamino, halogen and carboxy, and n is 0, 1, 2, 3, or 4, and R comprises one selected from the group consisting of an optionally substituted carbocyclyl (“carbocyclic”) group or an optionally substituted heterocyclyl (“heterocyclic”) group; or a salt or prodrug thereof.
[0014] In another aspect, the invention relates to a composition comprising a compound according to formula (I), or a salt or prodrug thereof, together with a pharmaceutically acceptable carrier, diluent or excipient.
[0015] In yet another aspect, the invention relates to a method for the treatment of a cancerous condition comprising the administration of a treatment effective amount of a compound of formula (I) or a pharmaceutically acceptable salt or prodrug thereof, to a subject in need of said treatment.
[0016] The invention further provides for the use of a compound of formula (I), or a salt or prodrug thereof, in the manufacture of a medicament for the treatment of a cancerous condition.
[0017] The invention also provides an antitumor agent comprising a compound of formula (I) or a pharmaceutically acceptable salt or prodrug thereof.
[0018] Other aspects and advantages of the invention will be apparent from the following description and the appended claims.
BRIEF DESCRIPTION OF DRAWINGS
[0019] [0019]FIG. 1 graphically depicts the long term effect of Compound (29) on the growth of HepG2/A2 cells which were treated with various concentrations of (29).
[0020] [0020]FIG. 2 graphically depicts the growth inhibition effects of 0.825 μM (29) or 200 nM TPA (12-O-tetradecanoyl-phorbol-13-acetate) in serum free medium for 2, 4, and 6 days.
[0021] [0021]FIG. 3 graphically depicts the growth of HepG2/A2 cells cultured in the absence or presence of 0.8 μM (29) in serum free medium for 24 hours, followed by changing to fresh medium and incubating for another 4 days.
[0022] [0022]FIG. 4 graphically depicts the effects of (29) on cell cycle distribution. HepG2/A2 cells were cultured in the absence or presence of 0.825 μM (29) for 24, 48, and 72 hours.
[0023] [0023]FIG. 5 depicts the effects of (29) on cell cycle distribution for HeLa cells treated in the absence or presence of 4 μM (29) for 4, 8, 12, and 16 hours.
[0024] [0024]FIG. 6 depicts the cell cycle progression for HeLa cells which had been synchronised at the G1/S boundary phase by treatment with 2 mM hydroxyurea for 14-16 hours. After release, the cells were incubated with 4 μM (29) containing medium or drug free medium for 4, 8, 12, and 16 hours.
[0025] [0025]FIG. 7 depicts the cell cycle progression of HeLa cells which were synchronised at the M phase by treatment with 0.7 μM nocodazole for 16 hours. After release, the cells were incubated in 4 μm (29) containing medium or drug-free medium for 4, 8, 12, and 16 hours.
[0026] [0026]FIG. 8 depicts the effect of (29) on SCM-1 cells.
[0027] [0027]FIG. 9 graphically depicts the effects of (29) on HeLa and H1299 cell lines.
DETAILED DESCRIPTION
[0028] As used herein, the term “carbocyclyl,” “carbocyclic,” or “carbocyclo” refers to single, polynuclear, conjugated, or fused cyclic hydrocarbon residues, optionally having one or more double bonds. A carbocyclic group may be non-aromatic or aromatic. Aromatic carbocyclic groups may also be referred to herein as “aryl.” Aromatic heterocyclyl groups may be referred to as “heteroaryl.”
[0029] Examples of carbocyclyl include mono-, bi- and tri-cyclic carbocyclyl residues such as: C 5 -C 8 mono-carbocyclyl (e.g. phenyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclopentenyl, cyclohexenyl, cycloheptenyl, cyclopentadienyl, cyclohexadienyl, cycloheptadienyl, cycloheptatrienyl); C 8 -C 12 bi-carbocyclyl (e.g., biphenyl, naphthyl, indenyl, isoindenyl, tetrahydronaphthyl, dihydroindenyl, tetralinyl, decalinyl, pentalenyl, azulenyl) and C 12 -C 14 tri-carbocyclyl (e.g., anthracenyl, fluorenyl, phenanthrenyl, dihydroanthracenyl, biphenylene, indacenyl). Particularly preferred carbocyclyl are aryl, such as phenyl, and fluorenyl preferably attached at the 2-position).
[0030] The term “heterocyclyl,” heterocyclic,”” or “heterocyclo” refers to single, fused, conjugated or polynuclear cyclic hydrocarbon residues, optionally having one or more double bonds, wherein a carbon atom is replaced with a heteroatom. Examples of heteroatoms include O, N and S. A heterocyclyl group may be non-aromatic, or aromatic (“heteroaryl”). Exemplary heterocyclyl groups include: unsaturated 3 to 6 membered heteromonocyclic groups containing 1 to 4 nitrogen atoms, for example, pyrrolyl, pyrrolinyl, imidazolyl, imidazolinyl, pyrazolyl, pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazolyl or tetrazolyl; saturated 3 to 6-membered heteromonocyclic groups containing 1 to 4 nitrogen atoms, such as, pyrrolidinyl, imidazolidinyl, piperidyl, pyrazolidinyl or piperazinyl; condensed saturated or unsaturated heterocyclic groups containing 1 to 5 nitrogen atoms, such as, indolyl, isoindolyl, indolinyl, isoindolinyl, indolizinyl, isoindolizinyl, benzimidazolyl, quinolyl, isoquinolyl, indazolyl, benzotriazolyl, purinyl, quinazolinyl, quinoxalinyl, phenanthradinyl, phenathrolinyl, phthalazinyl, naphthyridinyl, cinnolinyl, pteridinyl, perimidinyl, carbazolyl, acridinyl or tetrazolopyridazinyl; saturated 3 to 6-membered heteromonocyclic groups containing 1 to 3 oxygen atoms, such as tetrahydrofuranyl, tetrahydropyranyl, tetrahydrodioxinyl, unsaturated 3 to 6-membered hetermonocyclic group containing an oxygen atom, such as, pyranyl, dioxinyl or furyl; condensed saturated or unsaturated heterocyclic groups containing 1 to 3 oxygen atoms, such as benzofuranyl, chromenyl or xanthenyl; unsaturated 3 to 6-membered heteromonocyclic group containing 1 to 2 sulphur atoms, such as, thienyl or dithiolyl; unsaturated 3 to 6-membered heteromonocyclic group containing 1 to 2 oxygen atoms and 1 to 3 nitrogen atoms, such as, oxazolyl, oxazolinyl, isoxazolyl, furazanyl or oxadiazolyl; saturated 3 to 6-membered heteromonocyclic group containing 1 to 2 oxygen atoms and 1 to 3 nitrogen atoms, such as, morpholinyl; unsaturated condensed heterocyclic group containing 1 to 2 oxygen atoms and 1 to 3 nitrogen atoms, such as, benzoxazolyl or benzoxadiazolyl; unsaturated 3 to 6-membered heterormonocyclic group containing 1 to 2 sulphur atoms and 1 to 3 nitrogen atoms, such as, thiazolyl, thiazolinyl or thiadiazoyl; saturated 3 to 6-membered heteromonocyclic group containing 1 to 2 sulphur atoms and 1 to 3 nitrogen atoms, such as, thiazolidinyl, thiomorphinyl; and unsaturated condensed heterocyclic group containing 1 to 2 sulphur atoms and 1 to 3 nitrogen atoms, such as, benzothiazolyl or benzothiadiazolyl.
[0031] A preferred heterocyclyl group is heteroaryl, such as carbazolyl, preferably attached at the 3-position.
[0032] A carbocyclyl or heterocyclyl group may be optionally substituted, at a carbon or, where appropriate, nitrogen atom by one or more optional substituents. Suitable optional substituents may include halo (fluoro, chloro, bromo, iodo), hydroxy, C 1-8 straight or branched alkyl (e.g., methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, t-butyl, n-pentyl, isopentyl, etc), C 1-8 alkoxy (e.g., methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, sec-butoxy, t-butoxy, etc), amino, C 1-8 alkylamino (e.g., methylamino, ethylamino, n-propylamino, isopropylamino), C 1-8 dialkylamino (e.g., dimethylamino, diethylamino, dipropylamino, diisopropylamino), C(O)C 1-6 alkyl (“carbonyl,” e.g., acetyl, C(O)ethyl, C(O)propyl), OC(O)C 1-8 alkyl (“carbonyloxy,” e.g., acetoxy), carboxylic acid, CO 2 C 1-8 alkyl (“ester,” e.g., methyl ester, ethyl ester), benzyl (wherein the CH 2 or phenyl group thereof may be further optionally substituted), phenyl (which itself may be further optionally substituted), CONH 2 , CONHC 1-8 alkyl (e.g., methylamide, ethylamide), acetyl, benzoyl (wherein the phenyl group may be further optionally substituted), keto (where a CH 2 group is replaced with C═O), hydro (where a HC═CH— group is replaced by —CH 2 —CH 2 —), nitro, dimethyleneoxy, mercapto, C 1-8 alkylthio (e.g., SMe, SEt etc).
[0033] Thus, in a preferred embodiments of the invention, R is a phenyl group optionally substituted by one or more of: chloro, bromo, nitro, dialkylamine (e.g., dimethy-, diethyl-, or dipropyl (n-or iso-) amine), methoxy, ethoxy, n-propoxy, iso-propoxy, butoxy (n-, sec-, or t-), dimethyleneoxy, hydroxy, acetoxy.
[0034] Where a heterocyclyl group contains an sp3 nitrogen atom, preferably this may be optionally substituted by C 1-6 alkyl (e.g., methyl, ethyl, propyl) or C(O)C 1-6 alkyl (e.g., acetyl, C(O)ethyl, C(O)propyl).
[0035] A preferred R group is carbazolyl N-substituted by methyl, ethyl or propyl, butyl, pentyl, octyl, (preferably ethyl) or acetyl.
[0036] In a preferred form, the compounds of Formula (I) are presented in the form of a salt or prodrug, which may enhance solubility or bioavailability of the compound. The term “salt or prodrug” includes any pharmaceutically acceptable salt, ester, solvate, hydrate or any other compound which, upon administration to the recipient is capable of providing (directly or indirectly) a compound as described herein. However, it will be appreciated that non-pharmaceutically acceptable salts also fall within the scope of the invention since these may be useful in the preparation of pharmaceutically acceptable salts.
[0037] Suitable pharmaceutically acceptable salts include, but are not limited to salts of pharmaceutically acceptable inorganic acids such as hydrochloric, sulphuric, phosphoric nitric, carbonic, boric, sulfamic, and hydrobromic acids, or salts of pharmaceutically acceptable organic acids such as acetic, propionic, butyric, tartaric, maleic, hydroxymaleic, fumaric, maleic, citric, lactic, mucic, gluconic, benzoic, succinic, oxalic, phenylacetic, methanesulphonic, toluenesulphonic, benezenesulphonic, salicyclic sulphanilic, aspartic, glutamic, edetic, stearic, palmitic, oleic, lauric, pantothenic, tannic, ascorbic and valeric acids.
[0038] Base salts include, but are not limited to, those formed with pharmaceutically acceptable cations, such as sodium, potassium, lithium, calcium, magnesium, aminonium and alkylammonium.
[0039] Basic nitrogen-containing groups may be quarternised with such agents as lower alkyl halide, such as methyl, ethyl, propyl, and butyl chlorides, bromides and iodides; dialkyl sulfates like dimethyl and diethyl sulfate; and others.
[0040] The compounds of the invention may be in crystalline form either as the free compounds or as solvates (e.g. hydrates) and it is intended that both forms are within the scope of the present invention. Methods of salvation are generally known within the art.
[0041] Any compound that is a prodrug of a compound of formula (I) is within the scope and spirit of the invention. The term “pro-drug” is used in its broadest sense and encompasses those derivatives that are converted in vivo to the compounds of the invention. Such derivatives would readily occur to those skilled in the art, and include, for example, compounds where a free hydroxy group is converted into an ester, such as an acetate, or where a free amino group is converted into an amide (for example by acylation). Procedures for acylating the compounds of the invention are well known in the art and may include treatment of the compound with an appropriate carboxylic acid, anhydride or chloride in the presence of a suitable catalyst or base.
[0042] In yet another aspect, the invention relates to a method for the treatment of a cancerous condition comprising the administration of a treatment effective amount of a compound of the invention or a pharmaceutically acceptable salt or prodrug thereof, to a subject in need of said treatment.
[0043] The invention also provides a method of inducing apoptosis in a cell, particularly a cancerous cell, comprising contacting said cell with an effective amount of a compound of the invention for a time and under conditions sufficient to induce cell death.
[0044] The term “cancer” as used in “cancerous condition” is used in its broadest sense and includes benign and malignant leukemia, sarcomas and carcinomas as well as other neoplasia. Cancerous or tumorous conditions which may be treated by the compounds of the invention may be simple (monoclonal, i.e., composed of a single neoplastic cell type), mixed (polyclonal, i.e., composed of more than one neoplastic cell type and derived from more than one germ layer). Some examples of cancerous conditions which may be treated include breast, colon, uterus, prostate, lung, ovarian, skin, mouth, throat, liver, and stomach cancers, tumors and melanomas. As used herein, “cancerous condition” is also intended to refer to conditions which are precursors to a cancerous conditions, i.e., precancerous conditions.
[0045] The compounds of the invention may be used to treat humans or other mammalian subjects. The compounds of the invention are considered to be particularly suitable for the treatment of human subjects. Non-human subjects may include primates, livestock animals (e.g., sheep, cows, horses, goats, pigs) domestic companion animals (e.g., cats, dogs) laboratory test animals (e.g., mice, rats, guinea pigs, rabbits) or captive wild animals.
[0046] The compounds of the invention are administered to the subject in a treatment effective amount. As used herein, a treatment effective amount is intended to include at least partially attaining the desired effect, or delaying the onset of, or inhibiting the progression of, or halting or reversing altogether the onset or progression of the particular cancerous condition or pre-cancerous condition being treated, according to a desired dosing regimen.
[0047] As used herein, the term “effective amount” relates to an amount of compound which, when administered according to a desired dosing regimen, provides the desired therapeutic activity. Dosing may occur at intervals of minutes, hours, days, weeks, months or years or continuously over any one of these periods. Suitable dosages lie within the range of about 0.1 ng per kg of body weight to 1 g per kg of body weight per dosage. The dosage is preferably in the range of 1 μg to 1 g per kg of body weight per dosage, such as is in the range of 1 mg to 1 g per kg of body weight per dosage. In one embodiment, the dosage is in the range of 1 mg to 500 mg per kg of body weight per dosage. In another embodiment, the dosage is in the range of 1 mg to 250 mg per kg of body weight per dosage. In yet another preferred embodiment, the dosage is in the range of 1 mg to 100 mg per kg of body weight per dosage, such as up to 50 mg per kg of body weight per dosage.
[0048] One skilled in the art would appreciate that suitable dosage amounts and dosing regimens may be determined by the attending physician and may depend on the particular condition being treated, the severity of the condition, as well as the general health, age and weight of the subject.
[0049] The active ingredient may be administered in a single dose or a series of doses.
[0050] While it is possible for the active ingredient to be administered alone, it is preferable to present it as a composition, preferably as a pharmaceutical composition. The formulation of such compositions is well known to those skilled in the art. The composition may contain any suitable carriers, diluents or excipients. These include all conventional solvents, dispersion media, fillers, solid carriers, coatings, antifungal and antibacterial agents, dermal penetration agents, surfactants, isotonic and absorption agents and the like. It will be understood that the compositions of the invention may also include other supplementary physiologically active agents
[0051] The carrier must be pharmaceutically “acceptable” in the sense of being compatible with the other ingredients of the composition and not injurious to the subject. Compositions include those suitable for oral, rectal, nasal, topical (including buccal and sublingual), vaginal or parenteral (including subcutaneous, intramuscular, intravenous and intradermal) administration. The compositions may conveniently be presented in unit dosage form and may be prepared by any methods well known in the art of pharmacy. Such methods include the step of bringing into association the active ingredient with the carrier which constitutes one or more accessory ingredients. In general, the compositions are prepared by uniformly and intimately bringing into association the active ingredient with liquid carriers or finely divided solid carriers or both, and then if necessary shaping the product.
[0052] Compositions of the present invention suitable for oral administration may be presented as discrete units such as capsules, sachets or tablets each containing a predetermined amount of the active ingredient; as a powder or granules; as a solution or a suspension in an aqueous or non-aqueous liquid; or as an oil-in-water liquid emulsion or a water-in-oil liquid emulsion. The active ingredient may also be presented as a bolus, electuary or paste.
[0053] A tablet may be made by compression or moulding, optionally with one or more accessory ingredients. Compressed tablets may be prepared by compressing in a suitable machine the active ingredient in a free-flowing form such as a powder or granules, optionally mixed with a binder (e.g., inert diluent, preservative disintegrant (e.g. sodium starch glycolate, cross-linked polyvinyl pyrrolidone, cross-linked sodium carboxymethyl cellulose) surface-active or dispersing agent. Moulded tablets may be made by moulding in a suitable machine a mixture of the powdered compound moistened with an inert liquid diluent. The tablets may optionally be coated or scored and may be formulated so as to provide slow or controlled release of the active ingredient therein using, for example, hydroxypropylmethyl cellulose in varying proportions to provide the desired release profile. Tablets may optionally be provided with an enteric coating, to provide release in parts of the gut other than the stomach.
[0054] Compositions suitable for topical administration in the mouth include lozenges comprising the active ingredient in a flavoured base, usually sucrose and acacia or tragacanth gum; pastilles comprising the active ingredient in an inert basis such as gelatin and glycerin, or sucrose and acacia gum; and mouthwashes comprising the active ingredient in a suitable liquid carrier.
[0055] Compositions for topical administration, for example, to the skin, may be in the form of ointments, pastes, creams, gels, lotions, powders and the like and may include additional agents such as dermal penetration enhancers.
[0056] Compositions for rectal administration may be presented as a suppository with a suitable base comprising, for example, cocoa butter, glycerin, polyethylene glycol or gelatin.
[0057] Compositions suitable for vaginal administration may be presented as pessaries, tampons, creams, gels, pastes, foams or spray formulations containing in addition to the active ingredient such carriers as are known in the art to be appropriate.
[0058] Compositions suitable for parenteral administration include aqueous and non-aqueous isotonic sterile injection solutions which may contain anti-oxidants, buffers, bactericides and solutes which render the composition isotonic with the blood of the intended recipient; and aqueous and non-aqueous sterile suspensions which may include suspending agents and thickening agents. The compositions may be presented in unit-dose or multi-dose sealed containers, for example, ampoules and vials, and may be stored in a freeze-dried (lyophilised) condition requiring only the addition of the sterile liquid carrier, for example water for injections, immediately prior to use. Extemporaneous injection solutions and suspensions may be prepared from sterile powders, granules and tablets of the kind previously described.
[0059] Preferred unit dosage compositions are those containing a daily dose or unit, daily sub-dose, as herein above described, or an appropriate fraction thereof, of the active ingredient.
[0060] It should be understood that in addition to the active ingredients particularly mentioned above, the compositions of this invention may include other agents conventional in the art having regard to the type of composition in question. For example, those suitable for oral administration may include such further agents as binders, sweeteners, thickeners, flavouring agents disintegrating agents, coating agents, preservatives, lubricants and/or time delay agents. Suitable sweeteners include sucrose, lactose, glucose, aspartame or saccharine. Suitable disintegrating agents include corn starch, methylcellulose, polyvinylpyrrolidone, xanthan gum, bentonite, alginic acid or agar. Suitable flavouring agents include peppermint oil, oil of wintergreen, cherry, orange or raspberry flavouring. Suitable coating agents include polymers or copolymers of acrylic acid and/or methacrylic acid and/or their esters, waxes, fatty alcohols, zein, shellac or gluten. Suitable preservatives include sodium benzoate, vitamin E, alpha-tocopherol, ascorbic acid, methyl paraben, propyl paraben or sodium bisulphite. Suitable lubricants include magnesium stearate, stearic acid, sodium oleate, sodium chloride or talc. Suitable time delay agents include glyceryl monostearate or glyceryl distearate.
[0061] The compounds of the invention can be prepared in accordance with the -procedure outlined in Scheme I.
[0062] Thus, for example, Pictet-Spongler reaction (Valentine Jr D., et al, Synthesis, 1978, 329 and Kawashima, Y., et al, Chem. Pharm. Bull., 1995, 43, 329) by treatment of tryptamine with an appropriate aldehyde in the presence of trifluroacetic acid or acetic acid affords access to compounds of formula (IA). Subsequent oxidation, such as by treatment with DDQ (Kondo, K., et al, J Org. Chem., 1992, 57, 2460), affords access to the compounds of formula (IB).
[0063] It will be understood that the aromatic benzene ring of the starting tryptamine compound may be optionally substituted at one or more of the 4-, 5-, 6-, and 7-positions by a substituent. Suitable substituents may include hydroxy, C 1-6 alkoxy (e.g.,. methoxy, ethoxy, propoxy), benzyloxy C 1-6 acyloxy (e.g., OC(O)Me, OC(O)Et), amino, C 1-6 alkyl, C 1-6 dialkylamino, halogen (i.e., Br, Cl, I or F) or carboxy. A preferred substitution position is the 5- or 6-position, for example a 5- or 6-oxy substituted tryptamine such as 5- or 6-hydroxytryptamine (which may be alkylated or acetylated using known procedures) or 5- or 6-methoxy tryptamine. Some substituted starting tryptamines are commercially available (e.g., 5- and 6-hydroxy and 5- and 6-methoxy tryptamine). In a particularly preferred form, such substituted compounds of formula (1) also include compounds of the formula:
[0064] Wherein and R are as herein described and R′ is H, C 1-6 alkyl, C 1-6 acyl or benzyl.
[0065] Other compounds bearing a substituted aromatic ring may be prepared by the synthesis of suitably substituted indoles, for example, by Fischer indole synthesis using an appropriately substituted phenyl hydrazone or by electrophillic aromatic substitution of a suitably protected form of (IA) or (IB).
[0066] Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is to be understood that the invention includes all such variations and modifications which fall within the spirit and scope. The invention also includes all of the steps, features, compositions and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations of any two or more of said steps or features.
[0067] The invention will now be described with reference to the following examples which are included for the purpose of illustrating the invention and are not to be construed as limiting the generality hereinbefore described.
EXAMPLES
Example 1
[0068] General Methods for the Preparation of Compounds of Formula (I)
[0069] All melting points were taken on a Buchi mp B-540 apparatus and were uncorrected. UV and IR spectra were taken on a Hitachi V-3210 and JASCO A-100 IR spectrophotometers, respectively. EIMS spectra were obtained on a MAT 112S-JMS D300 spectrometer, using direct inlet systems. 1 H- and 13 C-NMR spectra were recorded on a Varian FT-300 spectrometer. Analytical thin-layer chromatography (TLC) was carried out on Kiesel gel GF 254 coated plates and detection was made under UV light.
[0070] EM Kieselgel 60 (230-400 mesh ASTM) was used for column chromatography.
[0071] General Procedure for the Synthesis of Compounds 4-16 (Formula IA)
[0072] To a stirred solution of tryptamine (1.6 g, 1 mmol) and the appropriate substituted aldehyde (1 mmol) in toluene (30 ml) at room temperature was slowly added trifluoroacetic acid (TFA, 2 ml). The reaction mixture was stirred at room temperature for two days. After evaporation of the solvent under vacuum, the residue was chromatographed on a silica gel column (60 g) and eluted with solvent mixture of CHCl 3 /MeOH by the following ratios and volumes (99:1, 98:2, 97:3, 96:4 and 95:5; each 100 ml), to afford compounds 4-16 with yields which varied in a range of 30-50%.
[0073] A mixture of tryptamine (1.6 g, 1 mmol) and the appropriate substituted aldehyde (1 mmol) in acetic acid (50 ml) was reacted at 100° C. overnight. The reaction product was added H 2 O (200 ml) and the H 2 O suspension was extracted with CHCl 3 soluble layer. After evapouration of the solvent under vacuum, the residue was chromatographed on a Si gel column (150 g) and eluted with solvent mixture of CHCl 3 /MeOH (15:1, 600 ml), to afford compounds 4-16 with yields in the range of 60-90%.
[0074] In a similar manner, 5-methoxy and 6-methoxy tryptamine may be used. Thus, to a stirred solution of 5-methoxy or 6-methoxy tryptamine (0.17 g, 0.1 mmol) and the appropriate aldehyde (1 mmol) in toluene (5 ml) is added TFA (0.3 ml), slowly at room temperature. The mixture is stirred at room temperature for two days. Following evaporation of the solvent under vacuum, the residue can be chromatographed as above.
[0075] General Procedure for the Synthesis of Compounds 17-29 (Formula IB)
[0076] To a stirred solution of compound of Formula 1A (4-16, 0.03 mmol) in ETOH (1 ml) and CHCl 3 (3 ml) at room temperature was added 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ, 40 mg). The reaction mixture was stirred for 30 minutes.
[0077] After concentration, the residue was applied on a preparative TLC plate and developed with CHCl 3 /MeOH (10:1) to yield compound 17-29.
Example 1a
1-(4′-Chlorophenyl)-1,2,3,4-tetrahydro-β-carboline (4)
[0078] White solid; C 17 H 15 N 2 Cl; 1 H-NMR (CDCl 3 ) δ 5.09 (1H, s, H-1), 3.11 (1H, m, H-3a), 3.28 (1H, m, H-3b), 2.85 (2H, m, H-4), 7.17 (3H, overlap, H-5, 6, 7), 7.57 (1H, d, J=8.4 Hz, H-8), 7.87 (1H, s, NH-9), 7.20 (2H, d, J=7.8 Hz, H-2′, 6′), 7.31 (2H, d, J=7.8 Hz, H-3′, 5′); 13 C-NMR (CDCl 3 ) δ 57.1 (d, C-1), 42.2 (t, C-3), 22.3 (t, C-4), 110.2 (s, C-4a), 133.7 (s, C-4b), 121.8 (d, C-5), 119.4 (d, C-6), 118.2 (d, C-7), 110.8 (d, C-8), 140.3 (s, C-8a), 135.9 (s, C-9a), 127.2 (s, C-1′), 129.8 (d, C-2′, 6′), 128.9 (d, C-3′, 5′), 133.9 (s, C-4′); EIMS m/z 285 (6), 284 (34), 283 (100, M + ), 281 (72), 255 (13), 254 (17), 253 (39), 252 (30), 219 (25), 218 (92), 217 (80), 189 (9), 171 (81), 169 (18), 154 (9), 144 (21), 143 (20), 130 (10), 123 (15), 115 (22), 109 (51).
Example 1b
1-(4′-Bromophenyl)-1,2,3,4-tetrahydro-β-carboline (5)
[0079] C 17 H 15 N 2 Br; 1 H-NMR (CDCl 3 ) δ 5.10 (1H, s, H-1), 3.12 (1H, m, H-3a), 3.30 (1H, m, H-3b), 2.87 (2H, m, H-4), 7.18 (3H, overlap, H-5, 6, 7), 7.65 (1H, d, J=6.9 Hz, H-8), 7.74 (1H, s, NH-9), 7.17 (2H, d, J=8.4 Hz, H-2′, 6′), 7.47 (2H, d, J=8.4 Hz, H-3′, 5′); 13 C-NMR (CDCl 3 ) δ 57.3 (d, C-1), 42.5 (t, C-3), 22.4 (t, C-4), 110.3 (s, C-4a), 133.6 (s, C-4b), 121.9 (d, C-5), 119.4 (d, C-6), 118.2 (d, C-7), 110.8 (d, C-8), 140.8 (s, C-8a), 135.9 (s, C-9a), 127.2 (s, C-1′), 130.2 (d, C-2′, 6′), 131.8 (d, C-3′,5′), 122.0 (s, C-4′); EIMS m/z 328 (43), 327 (37, M + ), 326 (48), 325 (34), 299 (17), 297 (18), 219 (28), 218 (100), 217 (93), 216 (30), 189 (9), 171 (64), 169 (17), 144 (19), 143 (21), 130 (15), 123 (27), 109 (55).
Example 1c
1-(4′-Nitrophenyl)-1,2,3,4-tetrahydro-β-carboline (6)
[0080] C 17 H 15 N 3 O 2 ; 1 H-NMR (CDCl 3 ) δ 5.28 (1H, s, H-1), 3.17 (1H, m, H-3a), 3.28 (1H, m, H-3b), 2.87 (2H, m, H-4), 7.27 (1H, d, J=7.5 Hz, H-5), 7.17 (2H, t, J=7.5 Hz, H-6,7), 7.57 (1H, d, J=7.5 Hz, H-8), 7.87 (1H, s, NH-9), 7.50 (2H, d, J=8.7 Hz, H-2′, 6′), 8.18 (2H, d, J=8.7 Hz, H-3′, 5′); 13 C-NMR (CDCl 3 ) δ 57.1 (d, C-1), 42.2 (t, C-3), 22.4 (t, C-4), 110.8 (s, C-4a), 127.1 (s, C-4b), 122.2 (d, C-5), 119.7 (d, C-6), 118.4 (d, C-7), 110.9 (d, C-8), 147.6 (s, C-8a), 135.6 (s, C-9a), 136.0 (s, C-1′), 129.4 (d, C-2′, 6′), 123.9 (d, C-3′, 5′), 149.3 (s, C-4′); EIMS m/z 293 (82, M + ), 292 (45), 264 (31), 247 (20), 218 (80), 217 (100), 216 (38), 204 (11), 189 (10), 171 (68), 169 (13), 154 (8), 144 (17), 143 (20), 130 (11), 115 (21), 109 (23).
Example 1d
1-(4′-Dimethylaminophenyl)-1,2,3,4-tetrahydro-β-carboline (7)
[0081] [0081] 1 H-NMR (CDCl 3 ) δ 5.11 (1H, s, H-1), 3.14 (1H, m, H-3a), 3.44 (1H, m, H-3b), 2.84 (2H, m, H-4), 7.56 (1H, d, J=7.0 Hz, H-5), 7.14 (2H, overlap, H-6,7), 7.75 (1H, d, J=7.5 Hz, H-8), 7.17 (2H, d, J=8.4 Hz, H-2′, 6′), 6.69 (2H, d, J=8.4 Hz, H-3′, 5′), 2.95 (6H, s, NMe 2 ); 13 C-NMR (CDCl 3 ) δ 53.0 (d, C-1), 41.2 (t, C-3), 25.9 (t, C-4), 113.2 (s, C-4a), 127.2 (s, C-4b), 122.1 (d, C-5), 119.5 (d, C-6), 118.8 (d, C-7), 112.0 (d, C-8), 136.4 (s, C-8a), 132.9 (s, C-9a), 122.1 (s, C-1′), 127.4 (d, C-2′, 6′), 112.9 (d, C-3′, 5′), 149.4 (s, C-4′), 40.7 (q, NMe 2 ).
Example 1e
1-(4′-N-Diethylaminophenyl)-1,2,3,4-tetrahydro-β-carboline (8)
[0082] C 21 H 25 N 3 ; 1 H-NMR (CDCl 3 ) δ 5.04 (1H, s, H-1), 3.12 (1H, m, H-3a), 3.40 (1H, m, H-3b), 2.83 (2H, m, H-4), 7.15 (3H, overlap, H-5,6,7), 7.55 (1H, d, J=8.4 Hz, H-8), 8.05 (1H, s, H-9), 7.15 (2H, d, J=9 Hz, H-2′, 6′), 6.63 (2H, d, J=9 Hz, H-3′, 5′), 1.17 (6H, t, J=7.1 Hz, CH 2 CH 3 ), 3.35 (4H, q, J=7.1 Hz, CH 2 CH 3 ); 13 C-NMR (CDCl 3 ) δ 57.3 (d, C-1), 42.7 (t, C-3), 22.4 (t, C-4), 109.3 (s, C-4a), 127.8 (s, C-4b), 122.3 (d, C-5), 119.0 (d, C-6), 118.0 (d, C-7), 110.8 (d, C-8), 135.7 (s, C-8a), 135.2 (s, C-9a), 127.4 (s, C-1′), 129.5 (d, C-2′, 6′), 111.6 (d, C-3′, 5′), 147.6 (s, C-4′), 12.5 (t, CH2 CH 3 ), 44.3 (q, CH 2 CH 3 ); EIMS m/z 319 (96, M + ), 318 (100), 290 (28), 289 (29), 276 (19), 275 (17), 274 (12), 260 (5), 245 (9), 219 (11), 218 (39), 217 (41), 216 (12), 204 (5), 189 (5), 171 (28), 169 (14), 160 (10), 144 (13), 143 (21), 137 (18), 130 (15), 123 (14), 109 (14).
Example 1f
1-(2′,4′-Dimethoxyphenyl)-1,2,3,4-tetrahydro-β-carboline (9)
[0083] Pale yellow solid; C 19 H 20 N 2 O 2 ; IR (KBr) v max 3410, 2950, 1615, 1505, 1465, 1300, 1160, 1040, 835, 715 cm −1 ; 1 H-NMR (CDCl 3 ) δ 5.54 (1H, s, H-1), 3.11 (1H, m, H-3a), 3.27 (1H, m, H-3b), 2.84 (2H, m, H-4), 7.23 (1H, d, J=6.8 Hz, H-5), 7.13 (2H, overlap, H-6,7), 7.53 (1H, d, J=6.8 Hz, H-8), 7.78 (1H, s, H-9), 6.53 (1H, d, J=2.4 Hz, H-3′), 6.37 (1H, d, J=8.7, 2.4 Hz, H-5′), 6.93 (1H, d, J=8.7 Hz, H-6′), 3.79, 3.87 (6H, s, OMe); 13 C-NMR (CDCl 3 ) δ 50.6 (d, C-1), 42.0 (t, C-3), 22.5 (t, C-4), 110.1 (s, C-4a), 127.4 (s, C-4b), 121.4 (d, C-5), 119.2 (d, C-6), 118.0 (d, C-7), 110.7 (d, C-8), 135.7 (s, C-8a), 134.6 (s, C-9a), 122.3 (s, C-1′), 98.8 (d, C-3′), 104.0 (d, C-5′), 110.7 (d, C-6′), 55.4, 55.6 (q, OMe); EIMS m/z 308 (100, M + ), 307 (73), 279 (31), 278 (43), 264 (12), 249 (13), 248 (30), 233 (9), 217 (7), 204 (18), 191 (8.4), 171 (38), 154 (17), 143 (21), 130 (13), 115 (15), 102 (13), 95 (9), 77 (13), 69 (22).
Example 1g
1-(3′,4′-Dimethoxyphenyl)-1,2,3,4-tetrahydro-β-carboline (10)
[0084] Pale yellow solid; C 19 H 20 N 2 O 2 ; IR (KBr) v max cm −1 ; 1 H-NMR (CDCl 3 ) δ 5.04 (1H, s, H-1), 3.10 (1H, m, H-3a), 3.32 (1H, m, H-3b), 2.89 (2H, m, H-4), 7.12 (3H, overlap, H-5,6,7), 7.56 (1H, d, J=5.7 Hz, H-8), 8.32 (1H, s, H-9), 6.80 (1H, s, H-2′), 6.75 (1H, d, J=8.1 Hz, H-5′), 6.78 (1H, d, J=8.1 Hz, H-6′), 3.70 (3H, s, 3′-OMe), 3.84 (3H, s, 4′-OMe); 13 C-NMR (CDCl 3 ) δ 57.9 (d, C-1), 42.9 (t, C-3), 22.3 (t, C-4), 109.7 (s, C-4a), 134.2 (s, C-4b), 121.4 (d, C-5), 120.5 (d, C-6), 119.0 (d, C-7), 111.2 (d, C-8), 135.8 (s, C-8a), 134.5 (s, C-9a), 127.2 (s, C-1′), 110.8 (d, C-2′), 148.6 (d, C-3′), 149.0 (s, C-4′), 110.8 (d, C-5′), 118.0 (d, C-6′), 55.7, 55.6 (q, OMe); EIMS m/z 308 (100, M + ), 307 (82), 291 (9.4), 279 (19), 264 (8), 249 (15), 248 (43), 233 (9), 217 (9), 204 (20), 191 (11), 171 (64), 154 (20), 143 (16), 130 (9), 115 (12), 102 (14), 95 (9), 77 (8).
Example 1h
1-(2′,5′-Dimethoxyphenyl)-1,2,3,4-tetrahydro-β-carboline (11)
[0085] Pale yellow solid; C 19 H 20 N 2 O 2 ; IR (KBr) v max 3410, 2950, 1680, 1505, 1465, 1135, 1045, 750 cm −1 ; 1 H-NMR (CDCl 3 ) δ 5.64 (1H, s, H-1), 3.20 (1H, m, H-3a), 3.32 (1H, m, H-3b), 2.88 (2H, m, H-4), 7.23 (1H, d, J=6.8 Hz, H-5), 7.12 (2H, overlap, H-6,7), 7.52 (1H, d, J=6.8 Hz, H-8), 7.85 (1H, s, H-9), 6.90 (1H, d, J=8 Hz, H-3′), 6.83 (1H, dd, J=8, 2 Hz, H-4′), 6.71 (1H, d, J=2 Hz, H-6′), 3.67, 3.81 (6H, s, OMe); 13 C-NMR (CDCl 3 ) δ 51.2 (d, C-1), 42.0 (t, C-3), 21.8 (t, C-4), 109.8 (s, C-4a), 129.7 (s, C-4b), 121.7 (d, C-5), 119.3 (d, C-6), 118.1 (d, C-7), 110.8 (d, C-8), 127.1 (s, C-1′), 111.8 (d, C-3′), 113.6 (d, C-4′), 115.5 (d, C-6′), 55.7, 56.2 (q, OMe); EIMS m/z 308 (100, M + ), 307 (56), 292 (4), 279 (21), 264 (6), 249 (2), 248 (67), 233 (15), 217 (12), 204 (24), 191 (7.7), 171 (79), 169 (20), 154 (17), 144 (30), 143 (27), 130 (18), 115 (18), 102 (15), 69 (39).
Example 1i
1-(3′,5′-Dimethoxyphenyl)-1,2,3,4-tetrahydro-β-carboline (12)
[0086] Pale yellow solid; C 19 H 20 N 2 O 2 ; IR (KBr) v max 3420, 2910, 1605, 1465, 1350, 1305, 1155, 1065, 845, 785 cm −1 ; 1 H-NMR (CDCl 3 ) δ 5.03 (1H, s, H-1), 3.11(1H, m, H-3a), 3.35 (1H, m, H-3b), 2.91 (2H, m, H-4), 7.15 (3H, overlap, H-5,6,7), 7.56 (1H, d, J=7 Hz, H-8), 8.13 (1H, s, H-9), 6.47 (2H, d, J=2.1 Hz, H-2′,6′), 6.44 (1H, d, J=2.1 Hz, H-4′), 3.71 (6H, s, OMe); 13 C-NMR (CDCl 3 ) δ 58.3 (d, C-1), 43.0 (t, C-3), 22.3 (t, C-4), 109.8 (s, C-4a), 127.3 (s, C-4b), 121.6 (d, C-5), 119.2 (d, C-6), 118.1 (d, C-7), 110.8 (d, C-8), 144.1 (s, C-8a), 135.8 (s, C-9a), 134.2 (s, C-1′), 106.5 (d, C-2′,6′), 161.1 (s, C-3′,5′), 100.0 (d, C-4′), 55.3 (q, OMe); EIMS m/z 308 (100, M + ), 307 (64), 279 (38), 278 (37), 264 (11), 249 (17), 248 (30), 233 (10), 220 (9), 217 (9), 204 (21), 191 (10), 171 (85), 154 (13), 144 (17), 130 (10), 115 (16), 102 (13), 95 (9), 77 (10).
Example 1j
1-(3′,4′,5′-Trimethoxyphenyl)-1,2,3,4-tetrahydro-β-carboline (13)
[0087] C 20 H 22 N 2 O 3 ; 1 H-NMR (CDCl 3 ) δ 5.85 (1H, s, H-1), 3.59 (1H, m, H-3a), 3.68 (1H, m, H-3b), 3.29 (2H, m, H-4), 7.32 (1H, d, J=8 Hz, H-5), 7.16 (1H, t, J=8 Hz, H-6), 7.11 (1H, J=8 Hz, H-7), 7.55 (1H, d, J=8 Hz, H-8), 6.73 (2H, s, H-2′,6′), 3.71 (9H, s, OMe); 13 C-NMR (CDCl 3 ) δ 56.1 (d, C-1), 41.7 (t, C-3), 51.5 (t, C-4), 109.4 (s, C-4a), 126.7 (s, C-4b), 122.4 (d, C-5), 119.7 (d, C-6), 118.4 (d, C-7), 111.1 (d, C-8), 136.2 (s, C-8a), 133.3 (s, C-9a), 128.6 (s, C-1′), 106.1 (d, C-2′,6′), 153.4 (s, C-3′,5′), 153.8 (s, C-4′), 56.1 (q, 3′,5′-OMe), 60.7 (q, 4′-OMe); EIMS m/z 338 (100, M + ), 337 (73), 309 (17), 279 (14), 278 (39), 262 (6.7), 247 (9), 234 (7.8), 219 (6.9), 204 (6.7), 191 (10), 180 (12), 171 (69), 169 (24), 154 (13), 144 (20), 130 (11), 115 (15), 109 (12), 77 (11), 69 (54).
Example 1k: 1-(6′-Nitro-1′-piperoyl)-1,2,3,4-tetrahydro-β-carboline (14)
[0088] C 18 H 15 N 3 O 4 ; 1 H-NMR (CDCl 3 ) δ 5.66 (1H, s, H-1), 3.17 (1H, m, H-3a), 3.25 (1H, m, H-3b), 2.89 (2H, m, H-4), 7.23 (1H, d, J=7.6 Hz, H-5), 7.16 (2H, overlap, H-6,7), 7.56 (1H, d, J=7.6 Hz, H-8), 8.04 (1H, s, H-9), 6.77 (1H, s, H-2′), 7.39 (1H, s, H-5′), 6.01 (2H, d, J=4.2 Hz, O—CH 2 —O); 13 C-NMR (CDCl 3 ) δ 52.4 (d, C-1), 42.0 (t, C-3), 22.1 (t, C-4), 111.1 (s, C-4a), 127.0 (s, C-4b), 122.0 (d, C-5), 119.5 (d, C-6), 118.3 (d, C-7), 110.9 (d, C-8), 136.0 (s, C-8a), 134.1 (s, C-9a), 132.6 (s, C-1′), 109.9 (d, C-2′), 151.7 (s, C-3′), 147.3 (s, C-4′), 104.9 (s, C-5′), 143.7 (s, C-6′), 102.9 (t, O—CH 2 —O); EIMS m/z 337 (6, M + ), 335 (6.7), 320 (9), 319 (70), 303 (56), 290 (93), 289 (100), 275 (6), 261 (24), 244 (11), 232 (13), 216 (9), 204 (33), 203 (19), 191 (18), 171 (20), 151 (18), 144 (32), 130 (53), 115 (50), 102 (52), 101 (22), 89 (20), 77 (25).
Example 1l
1 -(2′-Fluorenyl)-1,2,3,4-tetrahydro-β-carboline (15)
[0089] Yellow solid; C 24 H 20 N 2 ; IR (KBr) v max 3540, 2990, 1680, 1710, 1465, 745 cm −1 ; 1 H-NMR (CDCl 3 ) δ 5.23 (1H, s, H-1), 3.17 (1H, m, H-3a), 3.41 (1H, m, H-3b), 2.94 (2H, m, H-4); 13 C-NMR (CDCl 3 ) δ 58.3 (d, C-1), 43.0 (t, C-3), 22.6 (t, C-4), 110.2 (s, C-4a), 127.5 (s, C-4b), 121.7 (d, C-5), 119.4 (d, C-6), 118.3 (d, C-7), 110.9 (d, C-8), 143.9 (s, C-8a), 134.8 (s, C-9a), 125.1 (s, C-1′), 135.9 (s, C-2′), 125.1 (d, C-3′), 120.0 (d, C-4′), 141.2 (s, C-4′a), 141.8 (s, C-4′b), 120 (d, C-5′), 126.9 (d, C-6′), 126.8 (d, C-7′), 125.1 (d, C-8′), 143.5 (s, C-8′a), 36.9 (t, C-9′); EIMS m/z 336 (100, M + ), 335 (87), 334 (60), 307 (73), 306 (86), 304 (50), 292 (14), 171 (52), 152 (55), 143 (26), 115 (28).
Example 1m
1-(9′-Ethyl-3′-carbazole)-1,2,3,4-tetrahydro-β-carboline (16)
[0090] Yellow solid; C 25 H 23 N 3 ; IR (KBr) v max 3470, 2930, 1465, 1390, 750 cm −1 ; 1 H-NMR (CDCl 3 ) δ 6.04 (1H, s, H-1), 3.56 (1H, m, H-3a), 3.66 (1H, m, H-3b), 3.18 (1H, m, H-4a), 3.28 (1H, m, H-4b); 13 C-NMR (CDCl 3 ) δ 59.2 (d, C-1), 42.3 (t, C-3), 19.8 (t, C-4), 110.2 (s, C-4a), 127.5 (s, C-4b), 121.7 (d, C-5), 119.4 (d, C-6), 118.3 (d, C-7), 110.9 (d, C-8), 143.9 (s, C-8a), 134.8 (s, C-9a), 125.1 (s, C-1′), 135.9 (s, C-2′), 125.1 (d, C-3′), 120.0 (d, C-4′), 141.2 (s, C-4′a), 141.8 (s, C-4′b), 120 (d, C-5′), 126.9 (d, C-6′), 126.8 (d, C-7′), 125.1 (d, C-8′), 143.5 (s, C-8′a), 36.9 (t, C-9′); EIMS m/z 365 (100, M + ), 364 (8), 336 (46), 335 (45), 319 (8), 306 (18), 223 (5.7), 208 (7.3),183 (18), 171 (39), 160 (51), 153 (18), 144 (15), 130 (5), 115 (11).
Example 1n
1-(4′-Chlorophenyl)-1,2,3,4-tetrahydro-β-carboline (17)
[0091] [0091] 1 H-NMR (CDCl 3 ) δ 4.06 (2H, t, J=8.3 Hz, H-3), 2.99 (2H, t, J=8.3 Hz, H-4), 7.39 (1H, d, J=7.7 Hz, H-5), 7.32 (1H, dd, J=7.7, 7.2 Hz, H-6), 7.20 (1H, dd, J=7.8, 7.1 Hz, H-7), 7.67 (1H, d J=7.8 Hz, H-8), 8.04 (1H, s, NH-9), 7.49 (2H, d, J=8.6 Hz, H-2′,6′), 7.71 (2H, d, J=8.6 Hz, H-3′,5′).
Example 1o
1-(4′-Bromophenyl)-1,2,3,4-tetrahydro-β-carboline (18)
[0092] C 17 H 13 N 2 Br; 1 H-NMR (CDCl 3 ) δ 4.05 (2H, t, J=7.6 Hz, H-3), 2.98 (2H, t, J=7.6 Hz, H-4), 7.39 (1H, d, J=8.0 Hz, H-5), 7.31 (1H, d, J=8.0 Hz, H-6), 7.20 (1H, t, J=7.2 Hz, H-7), 7.60 (1H, d, J=7.2 Hz, H-8), 8.00(1H, s, NH-9), 7.47 (4H, s, H-2′,3′,5′,6′).
Example 1p
1-(4′-Dimethylaminophenyl)-3,4-dihydro-β-carboline (20)
[0093] [0093] 1 H-NMR (CD 3 OD) δ 3.94 (2H, t, J=7.8 Hz, H-3), 3.31 (2H, overlap, H-4), 7.55 (1H, d, J=8.4 Hz, H-5), 7.21 (1H, t, J=7.5 Hz, H-6), 7.40 (1H, t, J=7.5 Hz, H-7), 7.75 (1H, d, J=8.1 Hz, H-8), 7.81 (2H, d, J=9.0 Hz, H-2′,6′), 6.94 (2H, d, J=9.0 Hz, H-3′,5′), 3.16 (6H, s, NMe 2 ).
Example 1q
1-(4′-Diethylaminophenyl)-3,4-dihydro-β-carboline (21)
[0094] [0094] 1 H-NMR (CDCl 3 ) δ 3.08 (2H, dd, J=7.8, 15.3 Hz, H-3), 3.09 (2H, t, J=7.2 Hz, 1H-4), 7.62 (1H, d, J=8.4 Hz, H-5), 7.20 (1H, t, J=7.8 Hz, H-6), 7.38 (1H, t, J=7.8 Hz, 1H-7), 7.68 (1H, d, J=7.8 Hz, H-8), 10.6 (1H, brs, NH-9), 7.94 (2H, d, J=9.0 Hz, H-2′,6′), 6.55 (2H, d, J=9.0 Hz, H-3′,5′), 1.08 (6H, t, J=6.9 Hz, CH2 CH 3 ), 3.23 (4H, q, J=6.9 Hz, CH 2 CH 3 ).
Example 1r
1-(2′,4′-Dimethoxyphenyl)-3,4-dihydro-β-carboline (22)
[0095] [0095] 1 H-NMR (CDCl 3 ) δ 4.07 (2H, t, J=8.4 Hz, H-3), 3.10 (2H, t, J=8.4 Hz, H-4), 7.54 (1H, d, J=8.4 Hz, H-5), 7.41 (1H, d, J=8.4 Hz, H-6), 7.34 (1H, t, J=8.4 Hz, H-7), 7.63 (1H, d, J=8.4 Hz, H-8), 6.53 (1H, d, J=1.8 Hz, H-3′), 6.57 (1H, d, J=7.2, 1.8 Hz, H-5′), 7.19 (1H, d, J=7.2 Hz, H-6′), 3.82, 3.84 (6H, s, OMe).
Example 1s
1-(3′,4′-Dimethoxyphenyl)-3,4-dihydro-β-carboline (23)
[0096] [0096] 1 H-NMR (CDCl 3 ) δ 3.98 (2H, t, J=7.8 Hz, H-3), 2.96 (2H, t, J=7.8 Hz, H-4), 7.40 (1H, d, J=8.4 Hz, H-5), 7.20 (1H, d, J=8.4 Hz, H-6), 7.66 (1H, d, J=8.4 Hz, H-8), 7.30 (1H, d, J=1.8 Hz, H-2′), 6.86 (1H, d, J=7.8 Hz, H-5′), 7.15 (1H, d, J=7.8 Hz, H-6′), 3.77, 3.82, 3.84 (6H, s, OMe).
Example 1t
1-(2′,5′-Dimethoxyphenyl)-3,4-dihydro-β-carboline (24)
[0097] [0097] 1 H-NMR (CDCl 3 ) δ 4.11 (2H, t, J=8.6 Hz, H-3), 2.99 (2H, t, J=8.6 Hz, H-4), 7.34 (1H, d, J=8.1 Hz, H-5), 7.27 (1H, d, J=7.4 Hz, H-6), 7.15 (1H, t, J=7.4 Hz, H-7), 7.63 (1H, d, J=8.1 Hz, H-8), 8.50 (1H, brs, H-9), 7.00 (2H, s, H-3′,4′), 7.06 (1H, s, H-6′), 3.81 (6H, s, OMe).
Example 1u
1-(3′,5′-Dimethoxyphenyl)-3,4-dihydro-β-carboline (25)
[0098] [0098] 1 H-NMR (CDCl 3 ) δ 4.05 (2H, t, J=8.4 Hz, H-3), 2.98 (2H, t, J=8.4 Hz, H-4), 7.37 (1H, d, J=8.1 Hz, H-5), 7.18 (1H, t, J=7.5 Hz, H-6), 7.31 (1H, t, J=7.5 Hz, H-7), 7.66 (1H, d, J=8.1 Hz, H-8), 8.38)1H, s, H-9), 6.88 (2H, d, J=2.1 Hz, H-2′,6′), 6.58 (1H, dd, J=2.4, 2.1 Hz, H-4′), 3.83 (6H, s, OMe).
Example 1v
1-(3′,4′,5′-Trimethoxyphenyl)-3,4-dihydro-β-carboline (26)
[0099] [0099] 1 H-NMR (CDCl 3 ) δ 4.06 (2H, dd, J=8.1, 16.5 Hz, H-3), 3.01 (2H, dd, J=8.1, 16.5 Hz, H-4), 7.43 (1H, d, J=8.1 Hz, H-5), 7.22 (1H, dd, J=8.1, 7.8 Hz, H-6), 7.36 (1H, t, J=7.8 Hz, H-7), 7.69 (1H, d, J=7.8 Hz, H-8), 8.28 (1H, brs, H-9), 6.99 (2H, s, H-2′,6′), 3.92 (6H, s, OMe).
Example 1w
1-(6′-Nitro-1′-piperoyl)-3,4-dihydro-β-carboline (27)
[0100] [0100] 1 H-NMR (CDCl 3 ) δ 4.08 (2H, t, J=8.6 Hz, H-3), 3.06 (2H, t, J=8.6 Hz, H-4), 7.30 (1H, overlap, H-5), 7.20 (2H, overlap, H-6,7), 7.65 (1H, d, J=7.8 Hz, H-8), 8.11 (1H, s, H-9), 6.94 (1H, s, H-2′), 7.63 (1H, s, H-5′), 6.19 (2H, s, OCH 2 O).
Example 1x
1-(2′-Fluorenyl)-3,4-dihydro-β-carboline (28)
[0101] [0101] 1 H-NMR (CDCl 3 ) δ 3.03 (2H, t, J=7.8 Hz, H-3), 4.09 (2H, t, J=7.8 Hz, H-4), 3.99 (2H, s, H-9′), 7.20 (1H, t), 7.35 (1H, t), 7.40 (3-4H, m), 7.58 (1H, d), 7.66 (1H, d, J=7.8 Hz), 7.80 (1H, d), 7.83 (1H, d), 7.88 (1H, d, J=7.8 Hz), 8.00 (1H, s).
Example 1y
1-(9′-Ethyl-3′-carbazole)-3,4-dihydro-β-carboline (29)
[0102] [0102] 1 H-NMR (CDCl 3 ) δ 3.01 (2H, m, H-3), 2.60 (2H, m, H-4), 1.41 (3H, t, J=7.2 Hz, CH 2 CH 3 ), 4.32 (2H, q, J=7.2 Hz, CH 2 CH 3 ), 7.0-7.6 (m), 8.00 (1H, d), 8.11 (1H, s).
Example 2
[0103] Table 1 shows the IC 50 values for compounds 4-29, pacitaxel (taxol), and manzamine A (3) as tested against murine P-388 (leukemia) and human tumor cells including KB-16 (nasopharyngeal carcinoma), A-549 (lung adenocarcinoma), and HT-29 (colon adenocarcinoma) in vivo.
TABLE 1 Biological Evaluation of 1-Substituted 1,2,3,4-Tetrahydro-β-Carboline and 3,4-Dihydro-β-Carbolines. P-388 KB-16 A-549 HT-29 Compound R A B A B A B A B 4 0.2 0.7 0.6 0.9 17 0.5 0.9 1.2 1.3 5 1.0 2.1 3.0 1.1 18 1.1 2.4 3.0 1.2 6 0.8 1.1 0.9 1.5 7 2.2 1.7 1.6 0.7 20 2.9 4.8 50 3.0 8 0.07 0.2 1.1 1.1 21 0.7 0.3 1.8 1.3 9 0.6 0.7 1.1 1.1 22 0.6 2.7 0.5 0.5 10 2.8 >50 >50 >50 23 2.7 15 12 2.7 11 2.6 3.7 2.0 2.2 24 1.1 0.7 0.2 0.4 12 0.2 1.4 0.6 0.4 25 0.4 1.0 0.6 0.6 13 1.2 8.3 2.0 1.6 26 1.2 1.4 0.5 0.7 14 0.3 6.0 1.7 1.4 27 0.3 0.8 0.6 1.0 15 0.1 0.4 0.6 0.5 28 0.1 1.4 0.6 0.7 16 0.7 0.8 0.8 0.5 29 <0.001 <0.001 <0.001 <0.001 30 (paclitaxel) <0.001 <0.001 <0.001 <0.001 3 (manzamine A) 0.07 <0.001 0.03 0.1
Example 3
[0104] Compound (29) was shown in Example 2 to exhibit potent activity against the tested cell lines. Accordingly, compound (29) was screened in the HepG2/A2, HeLa, H1299, SCM-1, and normal skin fibroblast cell lines.
[0105] HepG2/A2 is a human hepatocellular carcinoma cell line, and it carries hepatitis B virus (HBV) intact genome and secretes HBV surface antigen (HbsAg). The cell growth is serum-independent so HepG2/A2 has been used as model system for screening anti-HBV and anticancer drugs.
[0106] Hep G2/A2 cells were treated with various concentrations of (29) for 2, 4 and 6 days. Cells were harvested and viable cells were determined by trypan blue exclusion, and cells were counted with hemocytometer. Data are expressed as mean±S.D. (n=3).
[0107] The results are depicted in FIG. 1.
[0108] Hep G2/A2 cells were cultured in the absence or presence of 200 nM TPA (12-0-tetradecnoyl-phorbol-13-acetate, a tumour promoter) or 0.825 μM (29) in serum-free medium for 2, 4 and 6 days. Viable cells were determined by trypan blue exclusion and cells were counted in a hemocytometer. Data are expressed as mean±S.D. (n=3). The results are depicted in FIG. 2.
[0109] Hep G2/A2 cells were cultured in the absence or presence of 0.8 μM (29) in serum free medium for 24 hr. The cells were then changed to a fresh medium without (29) and incubated for another 4 days. Viable cells were determined by trypan blue exclusion, and cells were counted with a hemocytometer every two days. Data are expressed as mean ±S.D. (n=3). The results are depicted in FIG. 3.
[0110] Log phase growth cultures of Hep G2/A2 cells were treated with or without 0.8 μM (29) in serum-free medium for 24, 48, 72 hr. After treatment, cells were fixed, and stained with propidium iodide. Their DNA contents were analysed using FACScan. The results are depicted in FIG. 4.
[0111] Log phase growth cultures of HeLa cells were treated with or without 4 μM (29) for 4, 8, 12, and 16, hrs. After treatment, cells were fixed, and stained with propidium iodide. Their DNA contents were analysed using FACSean. The results are depicted in FIG. 5.
[0112] HeLa were cells were synchronized at G1/S boundary by treating cells with 2 mM hydroxyurea for 14-16 hr. After release, cells were incubated in 4 μM (29) containing medium or drug-free medium for 4, 8, 12, and 16 hr. After treatment, cells were fixed, and stained with propidium iodide. Their DNA contents were analyzed using FACScan.
[0113] The results are depicted in FIG. 6.
[0114] HeLa cells were synchronized at M phase by treating cells with 0.7 μM nocodazole for 16 hr. After release, cells were incubated in 4 μM (29) containing medium or drug free medium for 4, 8, 12, 16 hr. After treatment, cells were fixed, and stained with 10 propidium iodide. Their DNA contents were analysed using FACScan.
[0115] The results are depicted in FIG. 7.
[0116] SCM-1 cells (stomach carcinoma cell line) were seeded on 24-wells plate at 5×10 5 cells/well. After 24 hr, medium were changed to fresh DMEM containing 10% serum and treated with various concentrations of (29) for 2 days. Viable cells were determined by trypan blue exclusion, and cells were counted in hemocytometer. Data are expressed as mean±SEM (n=3). The results are depicted in FIG. 8.
[0117] HeLa cells were seeded on 24-wells plate at 2×10 5 cells/well. After 24 hr, medium were changed to fresh DMEM containing 10% serum and treated with various concentrations of (29) for 2 days. Viable cells were determined by trypan blue exclusion, and cells were counted in hemocytometer. Data are expressed as mean±SEM (n—3). In H1299 cells (small cell lung cancer cell line), cells were incubated with RPMI containing 10% serum. The results are depicted in FIG. 9.
Example 4
[0118] The growth effects of compound 29 was tested on 8 different human tumour cell lines. Changes in cell proliferation based on the ability of viable cells to cause alamar Blue to change from its oxidized (non-fluorescent, blue) to a reduced (fluorescent, red) form were evaluated. With the results obtained from the alamarBlue reaction, cell proliferation was quantified and metabolic activity of viable cells examined. Test compound, (29), was tested for its effect on the proliferation of 8 different human tumor cell lines at five final assay concentrations from 100 to 0.01 μM through serial 10-fold dilutions, respectively.
[0119] Test Substance and Concentration
[0120] Compound 29 was dissolved in 100% ethanol and then diluted with Phosphate Buffer Saline (PBS, pH=7.4) to obtain initial working solutions of 10000, 1000, 100, 10 and 1 μM in 40% ethanol. In testing, 100-fold dilution was made in culture media to get final assay concentrations of 100, 10, 1, 0.1 and 0.01 μM in 0.4% of ethanol.
Cell Culture Media Cell Lines Culture Medium T47D RPMI 1640, 80%; Fetal Bovine Serum, 20%, supplemented with 0.2 I.U. bovine insulin per ml PC-6, U937 RPMI 1640, 90%; Fetal Bovine Serum, 10% PC-3 F-12 Nutrient Mixture (Ham), 90%: Fetal Bovine Serum, 10% MCF-7, Hep G2 Minimum Essential Medium, 90%; Fetal Bovine Serum, 10% HT-29 McCoy's Medium, 90%; Fetal Bovine Senim, 10% HL-60 RPMI 1640, 80%; Fetal Bovine Serum, 20%
[0121] All of media were supplemented with 1% Antibiotic-Antimycotic.
Cell Lines Cell Name Source Type of Cell Line MCF-7 ATCC HTB-22 Breast adenocarcinoma. Pleural effusion, human. T47D ATCC HTB-133 Breast, ductal carcinoma, pleural effusion, human. HT-29 ATCC HTB-38 Colon, adenocarcinoma, moderately well-differentiated grade II, human. HL-60 ATCC CCL-240 Promyelocytic leukemia, human. HepG2 ATCC HB-8065 Hepatoblastoma, liver, human. PC-6 Hokkaido Univ., Japan Lung, carcinoma, human. U-937 ATCC CRL-1593 Histiocytic lymphoma, human. PC-3 ATCC CRL-1435 Prostate, adenocarcinoma, human.
[0122] All of the human tumor cell lines were obtained from American Type Culture Collection (ATCC) except PC-6 (lung) from Hokkaido University, Japan and the tumor cells were all incubated at 37° C. with 5% CO 2 in air atmosphere.
[0123] Chemicals
[0124] Minimum Essential medium (GIBCO BRL, U.S.A.), Fetal Bovine Serum (GIBCO BRL, U.S.A.), Antibiotics-Antimycotic (GIBCO BRL, U.S.A.), McCoy's Medium (G1)3C0 BRL, U.S.A.), F-12 Nutrient Mixture (Ham) (GIBCO BRL, U.S.A.), RPMI 1640 (HyClone, U.S.A.), Mitomycin (Sigma, U.S.A.), Dimethylsulfoxide (Merck, Germany) and AlamarBlue (Biosource, U.S.A.).
[0125] Equipment
[0126] CO 2 Incubator (Forma Scientific Inc., U.S.A.), Inverted Microscope CK-4015 (Olympus, Japan), System Microscope BX-40 (Olympus, Japan), Centrifuge CT6D (Hitachi, Japan), Vertical Laminar Flow (High-Ten, Taiwan), Hemacytometer (Hausser Scientific Horsham, U.S.A.) and Spectrafluor Plus (Tecan, Austria).
[0127] Evaluation of Anti-Proliferation for Test Substance
[0128] Aliquots of 100 μl of cell suspension (about 2.5-5×10 3 /well) were placed in 96well microtiter plates in an atmosphere of 5% CO 2 at 37° C. After 24 hours, 100 μl of growth medium, 2 μL of test solution or vehicle (40% DMSO), was added respectively per well in duplicate for an additional 72 hour incubation. Thus, the final concentration of DMSO was 0.4%. The test compound was evaluated at concentrations of 100, 10, 1, 0.1 and 0.01 μM. At the end of the incubation, 20 μL of alamarBlue 75% reagent was added to each well for another 6-hour incubation before detection of cell viability by fluorescent intensity. Fluorescent intensity was measured using a Spectrafluor Plus plate reader with excitation at 530 nm and emission at 590 nm.
[0129] Determination of IC 50 , TGI and LC 50
[0130] The measured results were calculated according to the following formula:
PG (%)=100×(Mean F test −Mean F time0 )/(Mean F ctrl −Mean F time0 ).
If (Mean F test −Mean F time0 )<0, then
PG (%)=100×(Mean F test −Mean F time0 )/(Mean F time0 −Mean F blank )
[0131] Where
[0132] PG stands for percent growth.
[0133] Mean F time0 =The average of 2 measured fluorescent intensities of reduced alamarBlue at the time just before exposure of cells to the test substance.
[0134] Mean F test =The average of 2 measured fluorescent intensities of alamarBlue after 72-hour exposure of cells to the test substance.
[0135] Mean F ctrl =The average of 2 measured fluorescent intensities of alamarBlue after 72-hour incubation without the test substance.
[0136] Mean F blank =The average of 2 measured fluorescent intensities of alamarblue in medium without cells after 72-hour incubations.
[0137] A decrease of 50% or more (≧50%) in fluorescent intensity relative to vehicle-treated control indicated significant cytostatic or cytotoxic activity, and a semi-quantitative IC 50 , TGI and LC 50 were then determined by nonlinear regression using GraphPad Prism (GraphPad Software, U.S.A.).
[0138] IC 50 (50% Inhibition Concentration): Test Compound concentration at which the increase from time 0 in the number or mass of treated cells was only 50% as much as the corresponding increase in the vehicle-control at the end of experiment.
[0139] TGI (Total Growth Inhibition): Test compound concentration at which the number or mass of treated cells at the end of the experiment was equal to that at time 0 .
[0140] LC 50 (50% Lethal Concentration): Test compound concentration at which the number of mass of treated cells at the end of the experiment was half that at time 0 .
TABLE 1-1 The Percent Growth in Variable Concentrations of Test Compound (29) for Human Tumor Cells Percent Growth (Mean ± SEM, n = 2) Assay Concentration (μM) Name Blank Time 0 Vehicle 100 10 1 0.1 0.01 Breast −100 0 100 −100 ± 0 −48 ± 11 85 ± 8 94 ± 7 97 ± 1 MCF-7 Breast −100 0 100 −100 ± 4 25 ± 3 89 ± 3 88 ± 6 92 ± 2 T47D Colon −100 0 100 −94 ± 3 −30 ± 15 85 ± 3 101 ± 8 97 ± 4 HT-29 Leukemia −100 0 100 −100 ± 2 9 ± 3 73 ± 5 90 ± 6 99 ± 2 HL-60 Liver −100 0 100 −100 ± 3 −27 ± 7 81 ± 4 96 ± 11 106 ± 2 HepG2 Lung −100 0 100 −79 ± 11 24 ± 2 95 ± 5 97 ± 5 101 ± 1 PC-6 Lymphoma −100 0 100 −93 ± 0 −3 ± 4 90 ± 2 97 ± 6 103 ± 3 U-937 Prostate −100 0 100 −93 ± 1 −17 ± 9 82 ± 4 94 ± 3 100 ± 1 PC-3
[0141] [0141] TABLE 2-1 The Estimated IC 50 , TGI and LC 50 Test Compound Assay Name a IC 50 b TGI c IC 50 29 Breast, MCF-7 2.0 μM 4.2 μM 8.3 μM 29 Breast, T47D 6.0 μM 10.8 μM 19.2 μM 29 Colon, HT-29 2.3 μM 5.2 μM 11.7 μM 29 Leukemia, HL-60 3.2 μM 8.3 μM 22.0 μM 29 Liver, HepG2 2.2 μM 5.2 μM 12.5 μM 29 Lung, PC-6 5.0 μM 12.5 μM 32.5 μM 29 Lymphoma, U-937 3.5 μM 7.9 μM 18.3 μM 29 Prostate, PC-3 2.5 μM 6.2 μM 15.0 μM
[0142] While the invention has been described with respect to a limited number of examples, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised without departing from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims. | A composition includes a substituted dihydro- or tetrahydro-β-carboline of formula (II) or (III), wherein the aromatic ring of the carboline may include one or more substituents selected from the group consisting of hydroxy, C 1-6 alkoxy, benzyloxy, C 1-6 acyloxy, amino, C 1-6 alkyl, C 1-6 dialkylamino, halogen, and carboxy, and the C-1 position of the carboline may include a substitutent selected from the group consisting of a carbocyclic group and a heterocyclic group. The composition may include a salt or a prodrug of the substituted dihydro- or tetrahydro-β-carboline. The composition may further includes a pharmaceutically acceptable carrier, diluent, or excipient. | 2 |
TECHNICAL FIELD
[0001] The present invention relates generally to the structure of contacts of a sliding switch and, in particular, to the structure and configuration of stationary and movable contacts.
BACKGROUND OF THE INVENTION
[0002] There is a growing demand for sliding switches that use printed circuit boards, wire frames, and the like as stationary contacts. Such switches are used in vehicles (e.g., to control lights, turn signals, etc.), in household devices (e.g., as program switches for washers and dryers, etc.), and many other applications.
[0003] A conventional arrangement and structure of contacts of a sliding step switch is shown in FIGS. 12-14 . The arrangement depicts a three function configuration 510 for a sliding switch. A circuit board substrate 512 is formed of a synthetic resin made of an insulating material. A first conductive stationary contact pad 514 connected to a positive terminal of a power source is disposed on substrate 512 . Second, third, and fourth conductive stationary contact pads 516 , 518 , 520 connected to a negative terminal of a power source via a ground connection are disposed on substrate 12 . An insulating material 522 such as a solder mask is disposed between contact pads 514 , 516 , 518 , 520 .
[0004] A movable contact assembly 524 is mounted to an unillustrated holder which permits movement in the directions indicated by arrows A and B. Movable contact 524 includes first and second cylindrically shaped movable conductive contact heads 526 , 528 , mounted to respective conductive contact springs 530 , 532 . Contact springs 530 , 532 are connected together by a conductive metal strip 534 .
[0005] As shown on FIG. 12 , movable contact assembly 524 is in a first steady state position enabling current to flow from first contact pad 514 through movable contact 524 into second contact pad 516 to activate the function controlled by second contact pad 516 . As movable contact assembly 524 moves along a path in parallel with the direction of arrow B movable contact heads 526 , 528 moves to other positions where various functions are activated or deactivated. Likewise, movable contact assembly 524 can also move along a path in parallel with arrow A.
[0006] Electrical contact is made between a cylindrically shaped movable contact head and a flat stationary contact pad by pressing the contact head onto the stationary contact pad creating a line of electrical contact points. Upon operation of the switch, contact is broken by movement of the movable contact head past the edge of the stationary contact pad, a line of electrical contact points being maintained until just before breaking the contact.
[0007] Under specific voltage and current conditions, an arc is initiated at the last point of electrical contact as the electrical contacts are moved apart from each other and the electric potential between them causes electrons to bridge the interconnect space region. A current is maintained in the arc until the spacing between the contacts, and thus the resistance, increases enough to prevent electrons from bridging the gap. The current flowing through the gap generates heat, resulting in temperatures high enough to cause arc erosion as some of the contact material and nearby insulation is burned away.
[0008] FIG. 13 illustrates an electrical schematic of the switch configuration shown on FIG. 12 . FIG. 14 shows a sectional view of the switch configuration shown on FIG. 12 .
[0009] FIG. 15 illustrates the area 546 on a conventional contact pad where arcing occurs. This area is known as an arcing zone. During the life of the switch, debris fields 548 including both conductive and insulating material build up on the stationary contact pads and insulating regions as a result of arc erosion.
[0010] Consequently, during the life of the switch as the contact head passes across a debris field in a stationary contact pad, contact resistance between the contact head and contact pad increases across the line of contact points so that arcing occurs before the contact head reaches the edge of the switching pad. This occurrence adds to the size and density of the debris field. Sliding movement of the contact head through the debris field also causes debris particles to be dragged into a main or steady state area of contact, known as a contacting zone 542 , on the stationary contact pad 520 resulting in increased contact resistance when the contact head electrically contacts the contacting zone on the stationary contact pad during steady state use of the switch. The switch fails when debris causes the resistance between contacts to increase to a level whereby the contacts can no longer effectively complete a circuit or resistance becomes unacceptably high. FIG. 16 illustrates a graph showing voltage drop across contacts as a function of switching cycles of a conventional switch. In the illustrated example, voltage begins to increase and become unstable after about 25 arcing cycles.
[0011] During switch operation, debris particles are also dragged onto insulating material disposed between stationary contact pads as the contact head is moved from one contact pad to another. Debris on the insulation material reduces the dielectric strength of the insulation. The switch fails when the isolation resistance between the contact pads is reduced to a point where a circuit is established between contact pads. Lubrication of the contacts generally increases the rate at which debris is deposited onto the insulation.
[0012] As electrical performance requirements for sliding switches continue to increase, improvement in sliding switch performance is needed to satisfy increasingly stringent requirements.
SUMMARY OF THE INVENTION
[0013] The present invention provides contact structures for a sliding switch capable of extending the service life of the switch while maintaining voltage stability as compared with a conventional contact structure.
[0014] In accordance with a first aspect of the present invention, an improved contact structure is provided for a sliding switch having a stationary contact pad and a movable contact that is capable of directing accumulation of arcing debris away from a portion of a steady state contacting zone on the stationary contact pad. Consequently, a portion of the contacting area between stationary and movable contacts remains generally free of arcing erosion debris for an extended portion of the service life of the switch, thus extending the service life and improving voltage stability as compared to a conventional configuration.
[0015] In accordance with the first aspect of the present invention, a contact structure for a sliding switch includes a stationary contact pad and a movable contact which moves along a path extending between a non-contact position where the movable contact is electrically isolated from the stationary contact pad and a make-contact position where the movable contact maintains a primary electrical interface with the stationary contact pad, the stationary contact pad including a contacting zone that electrically makes contact with the movable contact when the movable contact is in the make-contact position, the stationary contact including an arcing zone that electrically breaks from or makes the movable contact when the movable contact moves from the make-contact position to the non-contact position and vice versa, the arcing zone providing an area where arcing occurs between the stationary contact and the movable contact, the stationary contact and the movable contact are shaped and configured such that when the contacting zone is projected in parallel with respect to the path onto the arcing zone, at least a portion of a projection of the contacting zone lies outside the arcing zone to provide a region within the contacting zone which is generally outside of an arcing erosion debris path created by the movable contact as it slides across the stationary contact.
[0016] In a preferred embodiment of a sliding switch including a movable contact and a flat stationary contact pad, a contact edge defined on the stationary contact pad such that the contact edge electrically contacts the movable contact as the movable contact moves between a non-contact position and a steady state contact position, the movable contact has a cylindrically shaped contact head and the flat stationary contact pad has a V-shaped contact edge configured to partially define a concave region on the stationary contact pad. Consequently, two arcing zones are provided and a substantially arc free region is provided in between. Thus a portion of a contacting zone projected along a path of movement of the movable contact head falls on the substantially arc free region. A portion of the contacting zone, therefore, lies generally outside of an arcing erosion debris path created by the movable contact as it slides across the stationary contact. Other contact configurations may be used so that at least a portion of a projection of the contacting zone lies outside the arcing zone to provide a region within the contacting zone which is generally outside of an arcing erosion debris path created by the movable contact as it slides across the stationary contact.
[0017] In accordance with a second aspect of the present invention, a contact configuration is provided which is capable of directing arcing toward the contact pad connected to the positive terminal of a power source and away from contact pads connected to a negative terminal. This configuration is advantageous because accumulation of conductive arcing debris between adjacent stationary contact pads is reduced compared with configurations known in the art. Thus, dielectric strength between adjacent contact pads is maintained over an extended portion of the service life of a switch.
[0018] Further in accordance with the second aspect of the present invention, a contact configuration for a sliding switch includes a first stationary contact pad connected to a positive terminal of a power source, a second stationary contact pad connected to a negative terminal, and a movable contact, an insulating region electrically isolating each of the contact pads, the movable contact is configured to be movable between a contact position where the movable contact electrically connects the first and second stationary contact pads and a non-contact position where movable contact is electrically isolated from the second stationary contact pad, the first stationary contact pad and movable contact being configured so that as the movable contact moves from the contact position to the non-contact position the movable contact breaks from second stationary contact pad before it breaks from the first stationary contact pad and as the movable contact moves from the non-contact position to the make contact position, the movable contact makes contact with the first stationary contact pad before it makes contact with the second stationary contact pad.
[0019] In accordance with a third aspect of the present invention, a contact configuration is provided which is capable of directing arcing to occur simultaneously at a contact pad connected to a negative terminal and a contact pad connected to a positive terminal. Consequently, arcing energy is split between each contact pad. This configuration results in a decreased formation of arcing erosion debris at the contact pad connected to the negative terminal as compared to the amount generated by configurations known in the prior art.
[0020] Further in accordance with the third aspect of the present invention, a contact configuration for a sliding switch includes a first stationary contact pad connected to a positive terminal of a power source, a second stationary contact pad connected to a negative terminal, and a movable contact, an insulating region electrically isolating each of the contact pads, the movable contact is configured to be movable between a contact position where the movable contact electrically connects the first and second stationary contact pads and a non-contact position where movable contact is electrically isolated from the second stationary contact pad, the first stationary contact pad and movable contact being configured so that as the movable contact moves from the contact position to the non-contact position the movable contact breaks from second stationary contact pad at the same time that it breaks from the first stationary contact pad and as the movable contact moves from the non-contact position to the make contact position, the movable contact makes contact with the first stationary contact pad at the same time that it makes contact with the second stationary contact pad.
[0021] These and other features and advantages of the present invention will become apparent from the following brief description of the drawings, detailed description, and appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The above-mentioned features of the present invention can be more clearly understood from the following detailed description considered in conjunction with the following drawings, in which like numerals represent like elements and in which:
[0023] FIG. 1 is a plan view of a first exemplary embodiment of a contact structure in accordance with the present invention;
[0024] FIG. 2 is a sectional view of the contact structure shown on FIG. 2 ;
[0025] FIG. 3 is a plan view of a second exemplary embodiment of a contact structure in accordance with the present invention;
[0026] FIG. 4 is a plan view of a third exemplary embodiment of a contact structure in accordance with the present invention;
[0027] FIG. 5 is a plan view illustrating an aspect of the present invention;
[0028] FIG. 6 is a graph depicting contact voltage between a movable contact head and stationary contact as a function of switching cycles for an exemplary embodiment of a contact configuration of the present invention;
[0029] FIG. 7 is a plan view illustrating an aspect of an alternate embodiment of the present invention;
[0030] FIG. 8 is a plan view illustrating an aspect of a second alternate embodiment of the present invention;
[0031] FIG. 9 is a plan view illustrating an aspect of a third alternate embodiment of the present invention;
[0032] FIG. 10 is a plan view illustrating an aspect of a fourth alternate embodiment of the present invention;
[0033] FIG. 11 is a section view of the an aspect of the fourth alternate embodiment of the present invention; and
[0034] FIG. 12 is a plan view of a contact structure known in the prior art;
[0035] FIG. 13 is an electrical schematic of the contact structure shown on FIG. 12 ;
[0036] FIG. 14 is a sectional view of a prior art contact structure;
[0037] FIG. 15 is a plan view illustrating an aspect of a prior art contact structure; and
[0038] FIG. 16 is a graph depicting an aspect of a prior art contact structure.
DETAILED DESCRIPTION OF THE INVENTION
[0039] As discussed above, contact configurations in accordance with the present invention are capable of providing an increased number of switching cycles while providing a more stable resistance across contacts than achieved by known contact configurations.
[0040] Referring to the figures, FIGS. 1-2 illustrate a first exemplary embodiment of a contact configuration 110 for a sliding switch.
[0041] A circuit board substrate 112 is formed of a synthetic resin made of an insulating material. A first conductive stationary contact pad 114 connected to a positive terminal of a power source is disposed on substrate 112 . Second, third, and fourth conductive stationary contact pads 116 , 118 , 120 connected to a negative terminal of a power source via a ground connection are disposed on substrate 112 . An insulating material 122 such as a solder mask is disposed between contact pads 114 , 116 , 118 , 120 .
[0042] A conductive movable contact assembly 124 is mounted to an unillustrated holder which permits movement in the directions indicated by arrows A and B. Movable contact assembly 124 includes first and second cylindrically shaped conductive movable contacts 126 , 128 , mounted to respective conductive contact springs 130 , 132 . Contact springs 130 , 132 are connected together by a conductive metal strip 134 . As shown on FIG. 1 , second movable contact 128 maintains electrical contact with respective stationary contact pads 116 , 118 , 120 generally at a contact line 128 a where the cylindrically shaped second movable contact 128 contacts a respective contact pad 116 , 118 , 120 .
[0043] As shown on FIG. 1 , movable contact assembly 124 is in a first steady state position enabling current to flow from first contact pad 114 through movable contact assembly 124 into second contact pad 116 to activate the function controlled by second contact pad 116 . As movable contact assembly 124 moves along a path in parallel with the direction of arrow B movable contacts 126 , 128 move to a second steady state position illustrated in phantom at 136 a, 136 b, respectively that represents a first OFF position. Movable contact assembly 124 can continue to move in the direction of arrow B to a third steady position illustrated by contacting zones shown in phantom at 138 a, 138 b where the function controlled by third contact pad 118 is activated, to a fourth steady position illustrated in phantom at 140 a, 140 b respectively, that represents a second OFF position, and to a fifth steady state position illustrated by contacting zones shown in phantom at 142 a, 142 b respectively, where the function controlled by fourth contact pad 120 is activated. Likewise, movable contact assembly 124 can move from fifth steady position illustrated by contacting zones shown in phantom at 142 a, 142 b respectively along a path in parallel with arrow A to other steady state positions.
[0044] As shown on FIG. 1 , fourth contact pad 120 has first and second protruding portions 144 a, 144 b that provide an electrical interface for discharge of arcing as second movable contact 128 moves between fourth and fifth positions in a direction parallel with respect to arrows A and B thereby making contact with or breaking contact from fourth contact pad 120 . Protruding portions 144 a, 144 b are each at least partially defined by a peripheral edge 146 that is in non-parallel relation with respect to contact line 128 a. As shown on FIG. 1 , first and second protruding portions 144 a, 144 b in combination form a “V” shape. The top of the “V” functioning as first and second arcing zones 148 a, 148 b, respectively, which provide an electrical interface for discharge of arcing.
[0045] As illustrated on FIG. 1 , when contacting zone 142 b is projected along movement path (indicated by arrows A and B) onto first and second arcing zones 148 a, 148 b, at least a portion of a projection 150 of contacting zone 142 b lies outside arcing zones 148 a, 148 b thereby providing a region 152 within contacting zone 142 b which is generally outside of an arcing erosion debris path ( 648 a, 648 b as shown on FIG. 5 ) created by second movable contact 128 as it slides across fourth contact pad 120 .
[0046] Likewise, second and third contact pads 116 , 118 have protruding portions that provide an electrical interface for discharge of arcing.
[0047] FIG. 5 shows a movable contact 628 and a stationary contact pad 620 similar to second movable contact 128 and fourth stationary contact pad 120 as shown on FIGS. 1 and 2 . FIG. 5 illustrates two areas, known as arcing zones 646 a, 646 b, that provide an electrical interface where arcing occurs on stationary contact pad 620 as movable contact head 628 moves between fourth and fifth steady state positions 640 a, 642 a as depicted on FIG. 1 . Arcing erosion debris fields including both conductive and insulating material that build up on stationary contact pad 620 and insulating material 622 during the service life of switch are generally shown at 648 a, 648 b. Debris fields 648 a, 648 b generally spread from arcing zones 646 a, 646 b in parallel with respect to a path of movement of contact head 628 in the direction of arrows A and B. Consequently, there is a portion 650 of contacting zone 642 a that generally remains outside of arcing erosion debris fields 648 a, 648 b over an extended portion of the service life of switch. As a result, as shown on FIG. 6 , contact voltage between movable contact 628 and stationary contact pad 620 remains low and stable over an extended portion of the service life of switch. This is a significant improvement over the performance, as shown by graph 702 on FIG. 16 , of contact configurations of switches known in the prior art.
[0048] FIG. 3 illustrates a second contact arrangement 310 for a sliding switch. Second contact arrangement 310 is similar to arrangement 110 depicted in FIG. 1 in that it includes second, third, and fourth conductive stationary contact pads 316 , 318 , 320 connected to a negative terminal of a power source via a ground connection are disposed on substrate 312 . Second contact arrangement 310 further includes a conductive movable contact assembly 324 including first and second cylindrically shaped conductive movable contacts 326 , 328 . Second contact arrangement 310 varies from first contact arrangement 110 in that a first stationary contact pad 314 which is connected to a positive terminal of a power source includes first, second, and third conductive pad portions 360 , 362 , 364 with a first insulating region 366 being disposed between first and second pad portions 360 , 362 and a second insulation region 368 being disposed between second and third pad portions 362 , 364 .
[0049] Second contact arrangement 310 is configured such that as the switch moves from an ON position to an OFF position, first movable contact 126 breaks contact first from first stationary contact pad 314 before breaking from one of second, third, or fourth contact pads 316 , 318 , 320 . Second contact arrangement 310 is also configured such that as the switch moves from an OFF position to an ON position, second movable contact 128 makes contact with one of second, third, or fourth contact pads 316 , 318 , 320 before first movable contact 326 makes contact with makes contact with first stationary contact pad 314 . Consequently, arcing occurs between first movable contact 326 and first stationary contact pad 314 and does not occur for a significant portion of the service life of switch between second movable contact 328 and second, third, and fourth stationary contacts pads 316 , 318 , 320 . This is advantageous in that conductive arc debris does not form between second, third, and fourth stationary contact pads 316 , 318 , 320 that reduces the dielectric strength between adjacent pads or which could cause a conductive circuit to form between pads. Protruding portions 344 a, 344 b are illustrated on second portion 362 of first stationary contact pad 314 . Arcing generally occurs at the protruding portions 344 a, 344 b generally within path 370 .
[0050] FIG. 4 illustrates a third contact arrangement 410 for a sliding switch. Third contact arrangement 410 is similar to arrangement 310 depicted in FIG. 3 and includes a first stationary contact power pad 414 which is connected to a positive terminal of a power source includes first, second, and third conductive pad portions 460 , 462 , 464 with a first insulating region 466 being disposed between first and second pad portions 460 , 462 and a second insulation region 468 being disposed between second and third pad portions 462 , 464 . A third insulating region 480 exists between first and second stationary contact pads 416 , 418 and a fourth insulation arrangement 482 exists between second and third stationary contact pads 418 , 420 .
[0051] Third contact arrangement 410 is configured such that as the switch moves from an ON position to an OFF position, a first movable contact 426 breaks contact from first stationary contact pad 414 simultaneously with second movable contact 428 breaking contact with one of second, third, or fourth contact pads 416 , 418 , 420 . Second contact arrangement 410 is also configured such that as the switch moves from an OFF position to an ON position, second movable contact 428 makes contact with one of second, third, or fourth contact pads 416 , 418 , 420 at the same time first movable contact 426 makes contact with first stationary contact pad 414 . Consequently, arcing occurs with both the first and second movable contacts 426 , 428 . This configuration is capable decreasing formation of arcing erosion debris at the contact pads connected to the negative terminal as compared to the amount generated by configurations known in the prior art.
[0052] FIG. 7 depicts a first alternate contact pad configuration 710 of many possible configurations in accordance with the present invention where a stationary contact pad 720 and a movable contact 728 are mutually shaped and configured such that at least a portion 750 of a contacting zone 742 a lies outside an arcing zone 746 a when contacting zone 742 a is projected along a path of movement of contact head 728 as depicted by arrows A and B. Therefore, a region 750 is provided within contacting zone 742 a which is generally outside arcing erosion debris path 748 a created by movable contact 728 as it slides across stationary contact pad 720 . FIG. 7 illustrates a protruding portion 744 a, a receiving edge 760 , and a line of contact 762 of movable contact 728 . The line of contact 762 and the receiving edge 760 are in nonparallel relation with respect to each other.
[0053] FIG. 8 depicts a second alternate contact pad configuration 810 of many possible configurations in accordance with the present invention where a stationary contact pad 820 and a movable contact 828 are mutually shaped and configured such that at least a portion 850 of a contacting zone 842 a lies outside an arcing zone 846 a when contacting zone 842 a is projected along a path of movement of contact head 828 as depicted by arrows A and B. Therefore, a region 850 is provided within contacting zone 842 a which is generally outside arcing erosion debris path 848 a created by movable contact 828 as it slides across stationary contact pad 820 . A receiving edge 860 is shown in nonparallel relation to movable contact 862 .
[0054] FIG. 9 depicts a third alternate contact configuration 910 of many possible configurations in accordance with the present invention. A conventional stationary contact pad 920 is rectangular shaped and movable contact 928 has first and second projecting portions 928 a, 928 b. Stationary contact pad 920 and movable contact 928 are mutually shaped and configured such that at least a portion 950 a contacting zone 942 a lies outside an arcing zone 946 a, 946 b when contacting zone 942 a is projected along a path of movement of movable contact 928 as depicted by arrows A and B. Therefore, a region 950 is provided within contacting zone 942 a which is generally outside arcing erosion debris path 948 a, 948 b created by movable contact 928 as it slides across stationary contact pad 920 .
[0055] FIGS. 10 and 11 depict a fourth alternate contact configuration 1010 of many possible configurations in accordance with the present invention. A stationary contact pad 1020 is rectangular shaped and movable contact 1028 includes first, second, and third furcations 1028 a,b,c. Stationary contact pad 1020 and movable contact head 1028 are mutually shaped and configured such that at least a portion 1052 b,c of contacting zone 1052 a,b,c lies outside an arcing zone 1048 when contacting zone 1052 a,b,c is projected along a path of movement of movable contact 1028 as depicted by arrows A and B.
[0056] The preferred embodiments shown and described herein are provided merely by way of example and are not intended to limit the scope of the invention in any way. Preferred dimensions, ratios, materials and construction techniques are illustrative only and are not necessarily required to practice the invention. It is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments herein. Further modifications and alterations may occur to others upon reading and understanding the specification. | A contact structure for a sliding switch includes a conductive stationary contact disposed on a base and a conductive movable contact for electrically contacting the stationary contact. The movable contact is movable along a path between a non-contact position and a make-contact position with respect to the stationary contact, and at least one of the contacts has a protruding portion that provides an electrical interface for discharge of arcing as the movable contact breaks from the stationary contact. As a result, the invention prevents or substantially reduces degradation in switch performance which might otherwise be caused by debris accumulation associated with arcing. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority from U.S. Provisional Patent Application Ser. No. 60/782,282, entitled “Onboard Regasification of LNG” and filed Mar. 15, 2006. The disclosure of the above-identified patent application is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates to a method and apparatus for regasification of liquefied natural gas (“LNG”) which relies on ambient air as the primary source of heat for vaporization and which is capable of being operated on a substantially continuous basis.
BACKGROUND TO THE INVENTION
Natural gas is the cleanest burning fossil fuel as it produces less emissions and pollutants than either coal or oil. Natural gas (“NG”) is routinely transported from one location to another location in its liquid state as “Liquefied Natural Gas (“LNG”). Liquefaction of the natural gas makes it more economical to transport as LNG occupies only about 1/600th of the volume that the same amount of natural gas does in its gaseous state. Transportation of LNG from one location to another is most commonly achieved using double-hulled ocean-going vessels with cryogenic storage capability referred to as “LNGCs”. LNG is typically stored in cryogenic storage tanks onboard the LNGC, the storage tanks being operated either at or slightly above atmospheric pressure. The majority of existing LNGCs have an LNG cargo storage capacity in the size range of 120,000 m 3 to 150,000 m 3 , with some LNGCs having a storage capacity of up to 264,000 m 3 .
LNG is normally regasified to natural gas before distribution to end users through a pipeline or other distribution network at a temperature and pressure that meets the delivery requirements of the end users. Regasification of the LNG is most commonly achieved by raising the temperature of the LNG above the LNG boiling point for a given pressure. It is common for an LNGC to receive its cargo of LNG at an “export terminal” located in one country and then sail across the ocean to deliver its cargo at an “import terminal” located in another country. Upon arrival at the import terminal, the LNGC traditionally berths at a pier or jetty and offloads the LNG as a liquid to an onshore storage and regasification facility located at the import terminal. The onshore regasification facility typically comprises a plurality of heaters or vaporizers, pumps and compressors. Such onshore storage and regasification facilities are typically large and the costs associated with building and operating such facilities are significant.
Recently, public concern over the costs and sovereign risk associated with construction of onshore regasification facilities has led to the building of offshore regasification terminals which are removed from populated areas and onshore activities. Various offshore terminals with different configurations and combinations have been proposed. For example, U.S. Pat. No. 6,089,022 describes a system and a method for regasifying LNG aboard a carrier vessel before the re-vaporized natural gas is transferred to shore for delivery to an onshore facility. The LNG is regasified using seawater taken from the body of water surrounding the carrier vessel which is flowed through a regasification facility that is fitted to and thus travels with the carrier vessel all of the way from the export terminal to the import terminal. The seawater exchanges heat with the LNG to vaporize the LNG to natural gas and the cooled seawater is returned to the body of water surrounding the carrier vessel. Seawater is an inexpensive source of intermediate fluid for LNG vaporisation but has become less attractive due to environmental concerns, in particular, the environmental impact of returning cooled seawater to a marine environment.
Regasification of LNG is generally conducted using one of the following three types of vaporizers: an open rack type, an intermediate fluid type or a submerged combustion type.
Open rack type vaporizers typically use sea water as a heat source for the vaporization of LNG. These vaporizers use once-through seawater flow on the outside of a heater as the source of heat for the vaporization. They do not block up from freezing water, are easy to operate and maintain, but they are expensive to build. They are widely used in Japan. Their use in the USA and Europe is limited and economically difficult to justify for several reasons. First the present permitting environment does not allow returning the seawater to the sea at a very cold temperature because of environmental concerns for marine life. Also coastal waters like those of the southern USA are often not clean and contain a lot of suspended solids, which could require filtration. With these restraints the use of open rack type vaporizers in the USA is environmentally and economically not feasible.
Instead of vaporizing liquefied natural gas by direct heating with water or steam, vaporizers of the intermediate fluid type use propane, fluorinated hydrocarbons or like refrigerant having a low freezing point. The refrigerant is heated with hot water or steam first to utilize the evaporation and condensation of the refrigerant for the vaporization of liquefied natural gas. Vaporizers of this type are less expensive to build than those of the open rack-type but require heating means, such as a burner, for the preparation of hot water or steam and are therefore costly to operate due to fuel consumption.
Vaporizers of the submerged combustion type comprise a tube immersed in water which is heated with a combustion gas injected thereinto from a burner. Like the intermediate fluid type, the vaporizers of the submerged combustion type involve a fuel cost and are expensive to operate. Evaporators of the submerged combustion type comprise a water bath in which the flue gas tube of a gas burner is installed as well as the exchanger tube bundle for the vaporization of the liquefied natural gas. The gas burner discharges the combustion flue gases into the water bath, which heat the water and provide the heat for the vaporization of the liquefied natural gas. The liquefied natural gas flows through the tube bundle. Evaporators of this type are reliable and of compact size, but they involve the use of fuel gas and thus are expensive to operate.
It is known to use ambient air or “atmospheric” vaporizers to vaporize a cryogenic liquid into gaseous form for certain downstream operations.
For example, U.S. Pat. No. 4,399,660, issued on Aug. 23, 1983 to Vogler, Jr. et al., describes an ambient air vaporizer suitable for vaporizing cryogenic liquids on a continuous basis. This device employs heat absorbed from the ambient air. At least three substantially vertical passes are piped together. Each pass includes a center tube with a plurality of fins substantially equally spaced around the tube.
U.S. Pat. No. 5,251,452, issued on Oct. 12, 1993 to L. Z. Widder, discloses an ambient air vaporizer and heater for cryogenic liquids. This apparatus utilizes a plurality of vertically mounted and parallelly connected heat exchange tubes. Each tube has a plurality of external fins and a plurality of internal peripheral passageways symmetrically arranged in fluid communication with a central opening. A solid bar extends within the central opening for a predetermined length of each tube to increase the rate of heat transfer between the cryogenic fluid in its vapor phase and the ambient air. The fluid is raised from its boiling point at the bottom of the tubes to a temperature at the top suitable for manufacturing and other operations.
U.S. Pat. No. 6,622,492, issued Sep. 23, 2003, to Eyermann, discloses apparatus and process for vaporizing liquefied natural gas including the extraction of heat from ambient air to heat circulating water. The heat exchange process includes a heater for the vaporization of liquefied natural gas, a circulating water system, and a water tower extracting heat from the ambient air to heat the circulating water.
U.S. Pat. No. 6,644,041, issued Nov. 11, 2003 to Eyermann, discloses a process for vaporizing liquefied natural gas including passing water into a water tower so as to elevate a temperature of the water, pumping the elevated temperature water through a first heater, passing a circulating fluid through the first heater so as to transfer heat from the elevated temperature water into the circulating fluid, passing the liquefied natural gas into a second heater, pumping the heated circulating fluid from the first heater into the second heater so as to transfer heat from the circulating fluid to the liquefied natural gas, and discharging vaporized natural gas from the second heater.
Atmospheric vaporizers are not generally used for continuous service because ice and frost build up on the outside surfaces of the atmospheric vaporizer, rendering the unit inefficient after a sustained period of use. The rate of accumulation of ice on the external fins depends in part on the differential in temperature between ambient temperature and the temperature of the cryogenic liquid inside of the tube. Typically the largest portion of the ice packs tends to form on the tubes closest to the inlet, with little, if any, ice accumulating on the tubes near the outlet unless the ambient temperature is near or below freezing. It is therefore not uncommon for an ambient air vaporizer to have an uneven distribution of ice over the tubes which can shift the centre of gravity of the unit and which result in differential thermal gradients between the tubes.
In spite of the advancements of the prior art, there is still a need in the art for improved apparatus and methods for regasification of LNG using ambient air as the primary source of heat.
SUMMARY OF THE INVENTION
According to a first aspect of the present invention there is provided a process for regasification of LNG to form natural gas, said process comprising the steps of:
(a) circulating an intermediate fluid between a vaporizer and an ambient air heater, the intermediate fluid being warmed by exchanging heat with the ambient air as the intermediate fluid passes through the ambient air heater, the intermediate fluid being cooled by exchanging heat with LNG as the intermediate fluid passes through the vaporizer; and, (b) subjecting the ambient air heater to a defrosting cycle by intermittently regulating the temperature of the intermediate fluid fed to the ambient air heater to a temperature greater than zero degrees Celsius using a source of supplemental heat.
In one embodiment, step (b) is conducted downstream of the ambient air heater.
The source of supplemental heat may be selected from the group consisting of: an exhaust gas heater; an electric water or fluid heater; a propulsion unit of a ship; a diesel engine; or a gas turbine propulsion plant; or an exhaust gas stream from a power generation plant.
In one embodiment, regasification of the LNG is conducted onboard an LNG carrier and the source of supplementary heat is heat recovered from the engines of the LNG carrier.
Heat exchange between the ambient air and the intermediate fluid in the ambient air heater may be encouraged through use of forced draft fans.
The intermediate fluid may be selected from the group consisting of: a glycol, a glycol-water mixture, methanol, propanol, propane, butane, ammonia, a formate, fresh water or tempered water. Preferably, the intermediate fluid may comprise a solution containing an alkali metal formate or an alkali metal acetate. More specifically, the alkali metal formate may be potassium formate, sodium formate or an aqueous solution of ammonium formate or the alkali metal acetate is potassium acetate or ammonium acetate.
In one embodiment, the ambient air heater is one of a plurality of ambient air heaters and step (b) is performed on each of the plurality of ambient air heaters sequentially. Alternatively or additionally, the ambient air heater comprises a horizontal tube bundle for exchanging heat with the intermediate fluid when the temperature of the ambient air is above 0° C. and a vertical tube bundle for exchanging heat with ambient air when the temperature of the ambient temperature falls below 0° C. Heat exchange between the ambient air and the intermediate fluid in the ambient air heater may be encouraged through use of forced draft fans with the horizontal tube bundle lies above the vertical tube bundle in closer proximity to forced draft fans.
According to a second aspect of the present invention there is provided a regasification facility for regasification of LNG to form natural gas, said apparatus comprising:
a vaporizer for regasifying LNG to natural gas; an ambient air heater for heating an intermediate fluid using ambient air as the primary source of heat; a circulating pump for circulating the intermediate fluid between the vaporizer and the ambient air heater, the intermediate fluid being warmed by exchanging heat with the ambient air as the intermediate fluid passes through the ambient air heater, the intermediate fluid being cooled by exchanging heat with LNG as the intermediate fluid passes through the vaporizer; and, a control device for regulating the temperature of the intermediate fluid fed to the ambient air heater to a temperature greater than zero degrees Celsius using a source of supplemental heat to subject the ambient air heater to a defrosting cycle.
In one embodiment, the source of supplemental heat is located downstream of the ambient air heater. The source of supplemental heat may be selected from the group consisting of: an exhaust gas heater; an electric water or fluid heater; a propulsion unit of a ship; a diesel engine; or a gas turbine propulsion plant; or an exhaust gas stream from a power generation plant.
In one embodiment, the regasification facility is provided onboard an LNG carrier and the source of supplementary heat is heat recovered from the engines of the LNG carrier. Alternatively or additionally, the apparatus further comprises a forced draft fan for encouraging heat exchange between the ambient air and the intermediate fluid in the ambient air heater.
In one embodiment, the ambient air heater is one of a plurality of ambient air heaters and the control device is arranged to subject each of the plurality of ambient air heaters sequentially to a defrosting cycle. Preferably, the ambient air heater comprises a horizontal tube bundle for exchanging heat with the intermediate fluid when the temperature of the ambient air is above 0° C. and a vertical tube bundle for exchanging heat with ambient air when the temperature of the ambient temperature falls below 0° C. Heat exchange between the ambient air and the intermediate fluid in the ambient air heater may be encouraged through use of forced draft fans and the horizontal tube bundle lies above the vertical tube bundle in closer proximity to forced draft fans.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to facilitate a more detailed understanding of the nature of the invention several embodiments of the present invention will now be described in detail, by way of example only, with reference to the accompanying drawings, in which:
FIG. 1 is a schematic side view of the RLNGC moored at a turret mooring buoy through which the natural gas is from the onboard regasification facility is transferred via a marine riser associated with a sub-sea pipeline to shore;
FIG. 2 is a flow chart illustrating a first embodiment of the regasification facility suitable for tropical climates where the minimum ambient temperature is about 10 to 15° C.;
FIG. 3 illustrates one embodiment of the ambient air heater of FIG. 2 provided with a horizontal tube bundle and a vertical tube bundle;
FIG. 4 is a flow chart illustrating a second embodiment of the regasification facility suitable for mildly cold climates; and,
FIG. 5 is a flow chart illustrating a third embodiment of the regasification facility suitable for much colder climates using supplemental heat provided by heat recovery and also from a back-up heater operating using a closed loop system in which a water-glycol mixture or other auxiliary fluid is heated using heat from a fired heater.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Particular embodiments of the method and apparatus for regasification of LNG using ambient air as the primary source of heat for vaporization are now described, with particular reference to the offshore regasification of LNG aboard an LNG Carrier, by way of example only. The present invention is equally applicable to use for an onshore regasification facility or for use on a fixed offshore platform or barge. The terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this invention belongs. In the drawings, it should be understood that like reference numbers refer to like members.
Throughout this specification the term “RLNGC” refers to a self-propelled vessel, ship or LNG carrier provided an onboard regasification facility which is used to convert LNG to natural gas. The RLNGC can be a modified ocean-going LNG vessel or a vessel that is custom or purpose built to include the onboard regasification facility.
The term “vaporizer” refers to a device which is used to convert a liquid into a gas.
A first embodiment of the system of the present invention is now described with reference to FIGS. 1 and 2 . In this first embodiment, a regasification facility 14 is provided onboard an RLNGC 12 and is used to regasify LNG that is stored aboard the RLNGC in one or more cryogenic storage tanks 16 . The onboard regasification facility 14 uses ambient air as the primary source of heat for regasification of the LNG and relies on circulating intermediate heat transfer fluid to transfer the heat from the ambient air to the LNG. The natural gas produced using the onboard regasification facility 14 is transferred to a sub-sea pipeline 18 for delivery of the natural gas to an onshore gas distribution facility (not shown).
In one embodiment of the present invention, LNG is stored aboard the RLNGC in 4 to 7 prismatic self-supporting cryogenic storage tanks, each storage tank 16 having a gross storage capacity in the range of 30,000 to 50,000 m 3 . The RLNGC 12 has a supporting hull structure capable of withstanding the loads imposed from intermediate filling levels in the storage tanks 16 when the RLNGC 12 is subject to harsh, multi-directional environmental conditions. The storage tank(s) 16 onboard the RLNGC 12 are robust to or reduce sloshing of the LNG when the storage tanks are partly filled or when the RLNGC is riding out a storm whilst moored. To reduce the effects of sloshing, the storage tank(s) 16 are provided with a plurality of internal baffles or a reinforced membrane. The use of membrane tanks allows more space on the deck 22 of the RLNGC 12 for the regasification facility 14 . Self supporting spherical cryogenic storage tanks, for example Moss type tanks, are not considered to be suitable if the RLNGC 12 is fitted with an onboard regasification facility 14 , as Moss tanks reduce the deck area available to position the regasification facility 14 on the deck of the RLNGC 12 .
A high pressure onboard piping system 24 is used to convey LNG from the storage tanks 16 to the regasification facility 14 via at least one cryogenic send-out pump 26 . Examples of suitable cryogenic send-out pumps include a centrifugal pump, a positive-displacement pumps, a screw pump, a velocity-head pump, a rotary pump, a gear pump, a plunger pump, a piston pump, a vane pump, a radial-plunger pumps, a swash-plate pump, a smooth flow pump, a pulsating flow pump, or other pumps that meet the discharge head and flow rate requirements of the vaporizers. The capacity of the pump is selected based upon the type and quantity of vaporizers installed, the surface area and efficiency of the vaporizers and the degree of redundancy desired. They are also sized such that the RLNGC 12 can discharge its cargo at a conventional import terminal at a rate of 10,000 m 3 /hr (nominal) with a peak in the range of 12,000 to 16,000 m 3 /hr.
A first embodiment of the regasification facility 14 is illustrated in FIGS. 2 and 3 , which embodiment is particularly suitable for tropical climates where the minimum ambient temperature is about 10 to 15° C. The regasification facility 14 includes at least one vaporizer 30 for regasifying LNG to natural gas and at least one ambient air heater 42 for heating a circulating intermediate fluid. To provide sufficient surface area for heat exchange, the vaporizer 30 may be one of a plurality of vaporizers arranged in a variety of configurations, for example in series, in parallel or in banks. The vaporizer 30 can be a shell and tube heater, a finned tube heater, a bent-tube fixed-tube-sheet exchanger, a spiral tube exchanger, a plate-type heater, or any other heater commonly known by those skilled in the art that meets the temperature, volumetric and heat absorption requirements for quantity of LNG to be regasified.
In this embodiment, LNG from the storage tank 16 is pumped to the required send-out pressure through a high pressure onboard piping system 24 by send-out pump 26 to the tube-side inlet 32 of the vaporizer 30 . In the vaporizer 30 , the LNG is regasified to natural gas through heat exchange with a circulating intermediate heat transfer fluid. Warm intermediate fluid is directed to the shell-side inlet 38 of the vaporizer 30 using a circulating pump 36 . The warm intermediate fluid transfers heat to the LNG to vaporize it to natural gas, and, in the process, the intermediate fluid is cooled. After the LNG has been vaporized in the tubes, it leaves the tube-side outlet 34 of the vaporizer 30 as natural gas. If the natural gas which exits the tube-side outlet 34 of the vaporizer 30 is not already at a temperature suitable for distribution into the sub-sea pipeline 18 , its temperature and pressure can be boosted using, for example a trim heater (not shown).
The cold intermediate fluid which leaves the shell-side outlet 40 of the vaporizer 30 is directed via a surge tank 28 to one or more ambient air heater(s) 42 which warm the circulating intermediate fluid as a function of the temperature differential between the ambient air and the temperature of the cold intermediate fluid entering the heater 42 . The cold intermediate fluid passes through the tubes of the ambient air heater 42 , with ambient air acting on the external surfaces thereof. Heat transfer between the ambient air and the intermediate fluid can be assisted through the use of forced draft fans 44 arranged to direct the flow of air towards the ambient air heater 42 , preferably in a downward direction.
The warm intermediate fluid which exits the ambient air heater 42 is returned to the vaporizer 30 to regasify the LNG. In this way, ambient air is used as the primary source of heat for regasification of the LNG. Ambient air is used (instead of heat from burning of fuel gas) as the primary source of heat for regasification of the LNG to keep emissions of nitrous oxide, sulphur dioxide, carbon dioxide, volatile organic compounds and particulate matter to a minimum. Heat is transferred to the intermediate fluid from the ambient air by virtue of the temperature differential between the ambient air and the cold intermediate fluid. As a result, the warm air is cooled, moisture in the air condenses and the latent heat of condensation provides an additional source of heat to be transferred to the circulating intermediate fluid in addition to the sensible heat from the air.
If the ambient temperature drops below a predetermined design average ambient temperature, a source of supplemental heat 50 is used to boost the temperature of the intermediate fluid to a required return temperature before the intermediate fluid enters the shell-side inlet 38 of the vaporizer 30 . When the temperature of the ambient air is sufficiently high (for example during the summer months) such that the ambient air is able to supply sufficient heat for regasification of the LNG, the source of supplemental heat 50 can be shut down. Controlling the return temperature of the intermediate fluid in this way is advantageous as it allows the vaporizer 30 to be operated under substantially stead-state conditions which are independent of changes in the ambient air temperature.
The source of supplemental heat 50 is from engine cooling, waste heat recovery from power generation facilities and/or electrical heating from excess power from the power generation facilities, an exhaust gas heater; an electric water or fluid heater; a propulsion unit of the ship (when the regasification facility is onboard an RLNGC); a diesel engine; or a gas turbine propulsion plant.
When the ambient temperature drops to close to 0° C., the temperature of the cold intermediate fluid which enters the tube-side inlet 41 of the ambient air heater 42 will be much lower than 0° C. As a consequence, the moisture which condenses out of the ambient air freezes on the external surfaces of the ambient air heater 42 and ice is formed. The rate and degree of icing which occurs depends on a number of relevant factors including but not limited to the temperature and relative humidity of the ambient air, the flow rate of the intermediate fluid through the ambient air heater 42 , and the heat transfer characteristics of the intermediate fluid and the materials of construction of the ambient air heater. The temperature and relative humidity of the ambient air can vary according to the seasons or the type of climate in the location at which regasification is conducted.
In tropical climates where the ambient temperature is significantly above 0° C. all year round, but drops below 0° C. during the night, ice is allowed to form on the external surfaces of the ambient air heater 42 during the night and the ambient air heater 42 is subjected to a defrosting cycle during daylight operations. As the ambient air temperature rises during daylight operations, a control device 53 , in the form of a temperature sensor 55 cooperatively associated with a flow control valve 57 , is used to ensure that the temperature of the cold intermediate fluid which enters the tube-side inlet 41 of the ambient air heater 42 is boosted and maintained above 0° C. By boosting and maintaining the temperature of the intermediate fluid which enters the tube-side inlet above 0° C., the ice which has accumulated on the external surfaces of the ambient air heater 42 overnight is caused to melt during the day. In this way, the ambient air heater 42 undergoes routine defrosting each day to improve efficiency, allowing the regasification facility 14 to operate on a continuous basis.
In the embodiment illustrated in FIG. 2 , the temperature sensor 55 measures the temperature of the intermediate fluid in the surge tank 28 and generates a signal to the flow control valve 57 which regulates the percentage flow of a bypass stream 58 of intermediate fluid through the source of supplemental heat 50 . In the event that the day-time ambient air temperature is so low that defrosting cannot be achieved even when all of the circulating intermediate fluid is directed to flow through the source of supplemental heat 50 , the control device 53 can be used instead to reduce the flow rate of the LNG through the send-out pumps 26 using flow control valve 59 . By reducing the flow rate of the LNG to the vaporizer 30 , the temperature of the cold intermediate fluid which leaves the shell-side outlet 40 of the vaporizer 30 rises. The control device 53 is used in this way to boost and maintain the temperature of the cold intermediate fluid which enters the tube inlet side 41 of the ambient air heaters above 0° C. to achieve defrosting.
To facilitate use of the process and apparatus of FIG. 2 in any climate, one specific embodiment of the ambient air heater 42 is illustrated in FIG. 3 , for which like reference numerals refer to like parts. With reference to FIG. 3 , the ambient air heater 42 comprises a horizontal tube bundle 43 (with the tubes arranged in an analogous manner to the tubes of a convention fin fan heater) and a vertical tube bundle 45 . The cold intermediate fluid which exits the shell-side outlet 40 of the vaporizer 30 is directed to a first surge tank 28 ′ and the temperature of the cold intermediate fluid is measured using a control device 53 , in the form of a temperature sensor 55 positioned at the first surge tank 28 ′ cooperatively associated with flow control valve 57 . The control device 53 is used to regulate the proportion of intermediate fluid which allowed to flow through each of the horizontal and vertical tube bundles, 43 and 45 respectively, as a function of the temperature of the cold intermediate fluid measured by the temperature sensor 55 .
The horizontal tube bundle 43 is ill-adapted for operation under conditions under which icing occurs. Therefore, the control device 53 allows the cold intermediate fluid to flow through the horizontal tube bundle 43 only if the temperature of the cold intermediate fluid measured by the temperature sensor 55 is greater than 0° C. The vertical tube bundle 45 is able to tolerate icing conditions due to the vertical arrangement of the tube bundle. Therefore, the control device 53 directs the cold intermediate fluid to flow through the vertical tube bundle 45 when the temperature of the cold intermediate fluid measured by the temperature sensor 55 is less than or equal to 0° C.
The cold intermediate fluid enters the vertical tube bundle 45 at the lowermost end of the vertical tube bundle 45 and is caused to flow upwardly therethrough. The partially warmed stream of intermediate fluid 67 which exits the vertical tube bundle 45 is directed to a second surge tank 28 ″. The temperature of the intermediate fluid which enters the surge tank 28 ″ has been raised above 0° C. and this partially warmed stream of intermediate fluid 67 is allowed to flow through the horizontal tube bundle 43 to further boost the temperature of the intermediate fluid before it is returned to the vaporizer 30 .
In the embodiment of FIG. 3 , the horizontal tube bundle 43 is physically arranged to lie above the vertical tube bundle 45 and in closer proximity to forced draft fans 44 which direct the flow of ambient air across the horizontal tube bundle 43 . This arrangement is adopted to reduce the overall footprint of the regasification facility 14 and to provide optimum heat transfer efficiency.
A second non-limiting embodiment of the present invention is illustrated with reference to FIG. 4 for which like reference numerals refer to like parts. This embodiment is particularly suitable for mildly cold climates. In this embodiment, LNG is pumped from the storage tank 16 at a nominal rate to the vaporizer 30 using send-out pumps 26 as described above. The cold intermediate fluid which exits the shell to a plurality of ambient air heaters 42 , each heater being arranged to exchange heat with ambient air.
With reference to FIG. 4 , the first ambient air heater 42 ′ is arranged to receive cold intermediate fluid from the vaporizer 30 . The second ambient air heater 42 ″ is arranged to receive a bypass stream 61 of the intermediate fluid which has been directed to flow through a source of supplemental heat 50 upstream of the second ambient air heater 42 ″. The temperature of the cold intermediate fluid which exits the shell-side outlet 40 of the vaporizer 30 is measured using the control device 53 , in the form of a temperature sensor 55 cooperatively associated with a flow control valve 57 . The control valve 57 is used to regulate the proportion of intermediate fluid which allowed to flow through each of the ambient heaters 42 ′ and 42 ″ by controlling the percentage flow rate of the bypass stream 61 . The source of supplemental heat 50 ′ is used to boost the temperature of the bypass stream 61 above 0° C. before the intermediate fluid enters the second ambient air heater 42 ″ and this is done so as to subject the second ambient air heater 42 ″ to a defrost cycle to remove ice which has formed on the external surfaces of the second ambient air heater 42 ″. The remaining cold circulating intermediate fluid enters directly into the tubes of the first ambient air heater 42 ′ and exchanges heat with ambient air in the manner described above in relation to the first embodiment.
It is to be clearly understood that whilst FIG. 4 illustrates the flow diagram used to arrange defrosting of the second ambient air heater 42 ″, the control device 53 is arranged to allow defrosting of each and all of the plurality of ambient air heaters 42 ′ and 42 ″ in turn. Whilst only two such ambient air heaters 42 are illustrated in FIG. 4 , it is to be understood that the regasification facility 14 can equally comprise a larger number of heaters to suit the capacity of natural gas to be delivered from the regasification facility. These ambient air heaters 42 can be arranged in a variety of configurations, for example in series, in parallel or in banks. It is preferable that the ambient air heaters are capable of withstanding the forces generated when ice is allowed to form on the external surfaces of the heater and in this regard, vertical tube bundles are preferred to horizontal tube bundles.
Using this arrangement, at least one of the plurality of heaters 42 is operating at maximum heat transfer capacity (in that the temperature differential between the cold intermediate fluid and the ambient air is kept to a maximum), so as to use the ambient air as the primary source of heat for regasification of the LNG to form natural gas. At the same time, at least one of the plurality of heaters is being subject to a defrost cycle to overcome any reduction in efficiency due to icing. If desired, the temperature of the circulating intermediate fluid downstream of the plurality of heaters 42 can be boosted before returning the warm intermediate fluid to the shell-side inlet 38 of the vaporizer 30 using a second source of supplemental heat 50 ″ in the manner described above for the first embodiment.
A third non-limiting embodiment of the present invention is illustrated with reference to FIG. 5 for which like reference numerals refer to like parts. This embodiment is particularly suitable for use in much colder climates. This embodiment is similar to the embodiment illustrated in FIG. 4 , the main difference being that the source of supplemental heat 50 used to boost the temperature of bypass stream 61 is in the form of a closed loop supplemental heat exchanger 52 . The bypass stream 61 passes through the tubes of the supplemental heat exchanger 52 and exchanges heat with an auxiliary intermediate heat transfer fluid (such as fresh water, tempered water, glycol or a mixture thereof which is heated by fired heater 62 .
With reference to the embodiment illustrated in FIG. 1 , the RLNGC 12 is designed or retrofitted to include a recess or “moonpool” 74 to facilitate docking of the RLNGC 12 with an internal turret mooring buoy 64 . The RLNGC 12 connects to the mooring buoy 64 in a manner that permits the RLNGC 12 to weathervane around the turret mooring buoy 64 . The mooring buoy 64 is moored by anchor lines 76 to the seabed 78 . The mooring buoy 64 is provided with one or more marine risers 66 which serve as conduits for the delivery of regasified natural gas through the mooring buoy 64 to the sub-sea pipeline 18 . Fluid-tight connections are made between the inlet of the marine risers 66 and a gas delivery line 72 to allow the transfer of natural gas from the regasification facility 14 onboard the RLNGC 12 to the marine riser 66 . A rigid arm connection over the bow 88 of the RLNGC to a single point or a riser turret mooring could equally be used, but is not preferred.
To allow the RLNGC 12 to pick up the mooring buoy 64 without assistance, the RLNGC 12 is highly maneuverable. In one embodiment, the RLNGC 12 is provided with directionally controlled propellers 48 which are capable of 360 degree rotation. The propulsion plant of the RLNGC 12 comprises twin screw, fixed pitch propellers 80 with transverse thrusters located both forward and aft that provide the RLNGC 12 with mooring and position capability. A key advantage of the use of a RLNGC 12 over a permanently moored offshore storage structure such as a gravity-based structure or a barge, is that the RLNGC 12 is capable of travelling under its own power offshore or up and down a coastline to avoid extreme weather conditions or to avoid a threat of terrorism or to transit to a dockyard or to transit to another LNG import or export terminal. In this event, the RLNGC 12 may do so with or without LNG stored onboard during this journey. Similarly, if demand for gas no longer exists at a particular location, the RLNGC 12 can sail under its own power to another location where demand is higher.
The RLNGC 12 is provided with an engine 20 , preferably a dual fuelled engine, for providing mechanical drive to the propellers of the RLNGC 12 so as to move the ship from one location to another. Advantageously, during regasification, the RLNGC is moored to a mooring buoy, at which time the engine 20 can be used to provide electricity to generate heat and/or to run the pumps 26 and 36 and other equipment associated with the regasification facility 14 . Thus, in the embodiment illustrated in FIG. 5 , the bypass stream 61 which flows through the supplemental heater 50 exchanges heat with an auxiliary heat transfer fluid such as fresh or tempered water, which in turn has been heated using waste heat from the engine 20 of the RLNGC 12 . In the process, the intermediate fluid is warmed and the engine 20 of the RLNGC 12 is cooled. This arrangement has the advantage of eliminating the use of large quantities of sea water which would otherwise be utilized for cooling the engines of a traditional LNG Carrier.
Suitable intermediate fluids for use in the process and apparatus of the present invention include: glycol (such as ethylene glycol, diethylene glycol, triethylene glycol, or a mixture of them), glycol-water mixtures, methanol, propanol, propane, butane, ammonia, formate, tempered water or fresh water or any other fluid with an acceptable heat capacity, freezing and boiling points that is commonly known to a person skilled in the art. It is desirable to use an environmentally more acceptable material than glycol for the intermediate fluid. In this regard, it is preferable to use an intermediate fluid which comprises a solution containing an alkali metal formate, such as potassium formate or sodium formate in water or an aqueous solution of ammonium formate. Alternatively or additionally, an alkali metal acetate such as potassium acetate, or ammonium acetate may be used. The solutions may include amounts of alkali metal halides calculated to improve the freeze resistance of the combination, that is, to lower the freeze point beyond the level of a solution of potassium formate alone. For example, potassium formate can be used to operate at temperatures as low as −70° C. during cold weather conditions in North America, Europe, Canada and anywhere else where ambient temperatures can fall below 0° C.
The advantage of using an intermediate fluid with a low freezing point is that the cold intermediate fluid which exits the shell-side outlet 40 of the vaporizer 30 can be allowed to drop to a temperature in the range of −20 to −70° C., depending on the freezing point of the particular type of intermediate fluid selected. This allows the ambient air heater 42 to operate efficiently even if the ambient air temperature falls to 0° C. Under such conditions, the natural gas which exits the tube-side outlet 34 may require heating to meet pipeline specifications.
Now that several embodiments of the invention have been described in detail, it will be apparent to persons skilled in the relevant art that numerous variations and modifications can be made without departing from the basic inventive concepts. For example, whilst only one vaporizer 30 and only one ambient air heater 42 are shown in FIG. 2 for illustrative purposes, it is to be understood that the onboard regasification facility may comprise any number of vaporizers and heaters arranged in parallel or series depending on the capacity of each vaporizer and the quantity of LNG being regasified. The vaporizers, heaters and fans (if used) are designed to withstand the structural loads associated with being disposed on the deck of the RLNGC during transit of the vessel at sea including the loads associated with motions and possibly green water loads as well as the loads experienced whilst the RLNGC is moored offshore during regasification. All such modifications and variations are considered to be within the scope of the present invention, the nature of which is to be determined from the foregoing description and the appended claims.
All of the patents cited in this specification, are herein incorporated by reference. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents forms part of the common general knowledge in the art, in Australia or in any other country. In the summary of the invention, the description and claims which follow, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention. | Liquefied natural gas is regasified to form natural gas, including circulation of an intermediate fluid between a vaporizer and an ambient air heater, where the intermediate fluid is warmed by exchanging heat with the ambient air as the intermediate fluid passes through the ambient air heater, and the intermediate fluid is cooled by exchanging heat with LNG as the intermediate fluid passes through the vaporizer. The ambient air heater is subjected to a defrosting cycle by intermittently regulating the temperature of the intermediate fluid fed to the ambient air heater to a temperature greater than zero degrees Celsius using a source of supplemental heat. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to U.S. Provisional Application Ser. No. 60/840,762, filed on Aug. 29, 2006, which is herein incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to image processing, and more particularly to a system and method for seeded image segmentation using l ∞ minimization.
2. Discussion of Related Art
Image segmentation is an important problem in computer vision. Traditionally, segmentation methods have focused on unsupervised segmentation, grouping elements of the image according to a criterion such as homogeneity. Recently, supervised image segmentation methods have gained popularity, giving the user (or preprocessor) the ability to affect the segmentation as needed for a particular application.
Supervised segmentation methods typically come in three types: 1) The user is asked to provide pieces (e.g., points) of the desired boundary which are then completed by the method, 2) The user is asked to specify an initial boundary that is “close” to the desired boundary which evolves to the desired boundary or 3) The user is asked to provide an initial labeling of some pixels as belonging to the desired object to be segmented or to the background, after which the method completes the labeling for all pixels.
For supervised segmentation methods taking user provided initial labeling as input, the user provides a partial labeling of the image, known as seeds, after which a complete labeling is constructed. Correction of an erroneous segmentation is accomplished by specifying additional labels for the initializing partial labeling. Two exemplary seeded segmentation methods are the Graph Cuts and Random Walker methods. These methods treat the image as a graph and minimize certain energy functionals on this graph to produce a segmentation. Since these energy functionals are convex, it is possible to find the global optimum. Moreover, due to the method definitions on general graphs, they may be applied without modification to an image of arbitrary dimension.
In both of the Graph Cuts and Random Walker methods, a weighted graph representation of the image is constructed. Nodes of this graph correspond to pixels in the image and edges are placed between nearby pixels. The edge weights are determined by a similarity measure on these pixels such that an edge connecting two pixels with a high similarity should have a large weight and vice versa.
In the Graph Cuts method, the foreground/background seeds are treated as source/sink nodes for a max-flow/min-cut operation. Using a maxflow/min-cut method, a set of edges with the minimum total weight is found and then returned as the object boundary. A problem with the Graph Cut method is the “small cut” behavior. Since this method tries to minimize the total edge weights in the cut, it may return very small segmentations as a result of low contrast, a small number of seeds or noise. The minimum-cut criterion may also cause problems by returning solutions in which the boundary takes a “shortcut” over a protruded section of the object in an attempt to minimize boundary length.
In the Random Walker method, the edge weights are treated as probabilities (when normalized by node degree) of a particle at one node traveling to a neighboring node. Given seeds, one may then compare the probability that a particle initiating at any node (pixel) travels first to the foreground or background seeds and assign that pixel to the corresponding label. It is possible to determine these probabilities for each pixel analytically without any simulation of random walks. While the Random Walker achieves good segmentation in the presence of weak boundaries and is insensitive to seed point selection, it is subject to loose segmentation, for example, in the presence of image noise.
Therefore a need exists for an improved seeded segmentation method.
SUMMARY OF THE INVENTION
A computer readable medium embodying instructions executable by a processor to perform a method for seeded image segmentation using to minimization, the method including providing an image comprising a set of pixels, wherein a foreground seed label is given for at least one pixel of the image and a background seed label is given for at least another pixel of the image, determining an affinity function for every pair of neighbor pixels, solving the l ∞ minimization, which assigns a probability to each pixel, labeling each pixel as foreground pixel or background pixel according to a threshold of the probability, and outputting the image including the segmentation labels.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the present invention will be described below in more detail, with reference to the accompanying drawings:
FIG. 1 is an illustration of a seeded image segmentation framework from which Graph Cuts (q=1), Random Walker (q=2) and l ∞ minimization are special cases;
FIG. 2 is a comparison of the Graph cuts, Random walker and l ∞ minimization methods;
FIG. 3 is a diagram illustrating that solutions to the q=1 and q=∞ cases may be achieved using different methods;
FIGS. 4A-C a segmentation boundary within a certain ambiguous regions;
FIGS. 5A-D illustrate comparisons of three choices of q on a weak boundary problem;
FIGS. 6A-D illustrate different choices of q reflecting different sensitivities to the seed locations;
FIGS. 7A-D illustrate different choices of q reflect different sensitivities to image noise;
FIGS. 8 Ai-v illustrate segmentation results for a Graph Cuts method on real images using an 8-connected lattice;
FIGS. 8 Bi-v illustrate segmentation results for a Random Walker method on real images using an 8-connected lattice;
FIGS. 8 Ci-v illustrate segmentation results for a regularized l ∞ method on real images using an 8-connected lattice according to an embodiment of the present disclosure;
FIG. 9 is a flow chart of a method according to an embodiment of the present disclosure; and
FIG. 10 is a system according to an embodiment of the present disclosure for performing seeded image segmentation using l ∞ minimization.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
According to an embodiment of the present disclosure, a method for seeded image segmentation uses an l ∞ norm. The method for the l ∞ optimization produces a segmentation that overcomes difficulties associated with the Graph Cuts or Random Walker methods.
Herein, a method for seeded image segmentation using l ∞ minimization is described.
Referring now to the method for seeded image segmentation using l ∞ minimization and concepts thereof; A graph includes of a pair G=(V, E) with vertices (nodes) v ε V and edges e ε E ⊂ V×V, with n=|V| and m=|E|. An edge, e, spanning two vertices, v i and v j , is denoted by e ij . A weighted graph assigns a value to each edge called a weight. The weight of an edge, e ij , is denoted by w(e ij ) or w ij and is assumed here to be nonnegative. The following will also assume that the graph is connected and undirected (i.e., w ij =w ji ). Herein, an 8-connected lattice is employed as a neighborhood structure. Each node may be identified with a pixel (2D) or voxel (3D), although nodes could be otherwise identified with groups of pixels/voxels.
Referring to FIG. 9 , consider a seeded image segmentation using l ∞ minimization on an image domain, V, written as A: assume that a set of pixels, F, labeled foreground and a set of pixels, B, and labeled background, such that F, B ⊂ V, F∩B=0 are given (e.g., interactively or via a preprocessor) 901 ; find a solution to
min s . t . C 1 2 Ax q q = [ ∑ e ij ∈ E ( w ij x i - x j ) q ] 1 q ,
x F = 1 ,
x B = 0. ( 1 )
[for q=∞] (s.t. (“such that”)) where A is the m×n node-edge incidence matrix defined as
A e ij υ k = { + 1 if i = k , - 1 if j = k , 0 otherwise , ( 2 )
and the m×m matrix C is the constitutive matrix, which is a diagonal matrix with the square weights of each edge along the diagonal 902 ; assign a set of segmentation labels 904 / 903 / 905 , s: V {0,1} such that
s i = { 1 if x i ≥ 1 2 , 0 if x i < 1 2 . ( 3 )
; and output the image including the segmentation labels 906 , for example, the output may be a display of a segmented image, an output to a computer readable media, etc.
An example of the method is summarized in FIG. 1 . Note that the above formulation could be interpreted from a continuous perspective in which (1) is replaced by
min∥∇ψ∥ q q (4)
where the sets F and B represent internal Dirichlet boundary conditions and the gradient operator is modified by an inhomogeneous metric tensor that changes spatially in response to intensity changes.
For graph based segmentation methods the edge weights may encode image intensity changes. A weighting function in these methods can be given as
w ij =exp(−√{square root over (β| g i −g j | 2 +|h i −h j | 2 )}), (5)
where g i indicates the image intensity at pixel i, h i indicates the spatial position of pixel i and β is a free parameter. In the context of (4), these weights would be equivalent to a spatially varying metric. Note that pixel affinity could equally be derived from changes in color, texture, etc.
The method given by FIG. 1 leaves only one remaining choice: the value of q (parameter q is the p—norm of the gradients). Herein, it is shown that the choice of q=1 leads to the Graph Cuts method and the choice of q=2 leads to the Random Walker method. This situation is summarized in FIG. 2 . Following the justification of the above statements, the choice q=∞ is described.
Referring to the q=1 case—Graph Cuts; If q=1 is substituted into (1), and the method given by FIG. 1 gives the solution of:
min
s
.
t
.
C
1
2
Ax
=
∑
e
ij
∈
E
w
ij
x
i
-
x
j
,
x
F
=
1
,
x
B
=
0.
(
6
)
The dual formulation of (6) is
max y B , s.t. A T y=δ F y F +δ B y B , 0 ≦y ij ≦w ij ∀e ij ε E, (7)
where δ F,B are vectors of length n with 1's in entries corresponding to foreground and background seeds respectively, and zeros elsewhere.
Upon closer inspection, it can be seen that (7) is the maximum-flow problem, where y B is the total flow, subject to the flow conservation principle. Therefore, formulation (1) gives rise to the min-cut/max-flow problem for q=1. The primal problem (6) also demonstrates the minimum cut problem—Minimize a weighted cut, represented by x, between terminals F and B. The solution of (6) will be a binary solution, x i ε {0,1}, due to the totally unimodular property of the min-cut problem. Since the solution of (6) will be binary, the thresholding given by FIG. 1 (see also FIG. 9 , block 905 ) will have no consequence, and the labeling (see FIG. 9 , block 905 ) will be equal to the optimal solution of (6). As a result, the Graph Cuts image segmentation method gives the same solution as the method given by FIG. 1 when q=1.
Referring to the q=2 case—Random Walker; The q=2 case corresponds to the Random Walker segmentation method. For q=2, (1) becomes
min s . t . C 1 2 Ax 2 2 = ∑ e ij ∈ E w ij 2 ( x i - x j ) 2 = x T A T CAx ,
x F = 1 ,
x B = 0. ( 8 )
A minimization of this form is described in the Random Walker formulation for a case of two labels. Solution of (8) yields the desired Random Walker probabilities, which are then thresholded to produce the foreground/background labeling 905 . Therefore, the Random Walker image segmentation method with two labels gives exactly the same solution as the method given by FIG. 1 when q=2.
Hence, the method given by FIG. 1 is shown to produce the Graph Cuts and Random Walker segmentation solutions when q=1 and q=2, respectively.
Turning now to the q=∞ case; If q→∞, (1) becomes
lim q → ∞ ∑ e ij ∈ E w ij q x i - x j q q = max e ij ∈ E w ij x i - x j ︸ ρ lim q → ∞ ∑ e ij ∈ E ( w ij x i - x j ρ ) q q ︸ 1 = ρ . ( 9 )
Consequently, the overall optimization problem 904 may be written as
min max e ij ε E w ij |x i −x j |, st x F =1, x B =0. (10)
This form is a combinatorial formulation of a minimal Lipschitz extension.
In the following description, let u v denote a path in G from node u ε V to v ε V. Also, let ρ=max e ij E w ij |x i −x j | for a solution x to (10).
For any path π: F v, we have the inequalities:
∑
e
ij
∈
π
x
i
-
x
j
≥
x
F
-
x
B
=
1
,
(
11
)
∑
e
ij
∈
π
x
i
-
x
j
≤
∑
e
ij
∈
π
w
ij
-
1
ρ
.
(
12
)
Combining these two inequalities yields
ρ
≥
(
∑
e
ij
∈
π
w
ij
-
1
)
-
1
,
∀
π
:
F
B
.
(
13
)
A maximum lower bound for ρ is attained with the shortest path between a foreground and background seed over the reciprocal weights (w ij −1 ).
Let d i F and d i B denote the shortest path length from node v i ε V to a foreground and background node using reciprocal weights respectively.
Theorem 1. Let x be defined as
x i =min{ρ d i B , 1}. (14)
This potential vector is an optimal solution for (10).
Proof. Begin by checking the boundary conditions given in (10).
x i =1, i ε F. Since ρ −1 ≦d i B for all i ε F, ρd i B ≦1, which implies x i =1.
x i =0, i ε B. For all i ε B, d i B =0, therefore x i =0.
w ij |x i −x j |≦ρ. Without loss of generality, assume x i ≧x j , which implies that d i B ≧d j B .
If x j =1, then x i =1. Therefore, this property is readily satisfied. Assume otherwise. It is known that d i B −d j B ≦w ij −1 by the shortest path property. So, we have
w ij ( x i −x j )≦ w ij (ρ d i B −ρd j B )≦ρ.
A practical consequence of Theorem 1 is that the potential vector x may be determined in O(m+n log n) time by finding d i B for each node, which needs a single source (treating all nodes in F as a single node) all shortest paths computation. Although the above discussion offers a simple, efficient method of finding an optimal solution to (10), it should be noted that this solution may be achieved using different methods.
FIG. 3 illustrates to the relationship between the q=1 and q=∞ cases. F is the foreground node (set to unity), B is the background node (set to zero). The remaining node, u, may take any value ranging between [0, 1] without affecting the objective function in (1). For this reason, regularizing the q=∞ case with an l 1 term does not remove the degeneracy and therefore an l 2 regularizer is used. Each edge has unity weight.
Additionally, the situation in FIG. 3 illustrates the degeneracy of the l 1 minimization of (6) 904 , as well. In this graph, the value of x u can take any value between 0 and 1 without affecting the optimum of (10) or (6). Specifically, for any x u ε [0,1], l 1 (x)=2 and l ∞ (x)=1. Hence, there exists an infinite number of solutions for these problems and some regularization 903 is needed to obtain a unique solution. Regardless of the regularization method employed, a surprising aspect of the solution in the l ∞ case (with regards to the segmentation) is that some pixels are guaranteed to take the foreground label (have solution greater than ½) while others are guaranteed to take the background label (have solution less than ½). However, there remains an “ambiguous region” in which the method of regularization 903 determines the labeling 905 . These regions may be determined for the l ∞ method.
Theorem 2. Let ρ be the minimum value of l 1 (x). Then, for any potential vector x satisfying the boundary conditions in (10), with w ij |x i −x j |≦ρ, we have
1 −ρd u F 23 x u ≦ρd u B , ∀u ε V. (15)
Proof For each node u ε V, let π F and π B denote the shortest paths from F and B to u i respectively. Then
∑
e
ij
∈
π
F
(
x
i
-
x
j
)
=
1
-
x
u
,
(
16
)
∑
e
ij
∈
π
F
(
x
i
-
x
j
)
≤
∑
e
ij
∈
π
F
x
i
-
x
j
≤
ρ
d
u
F
.
(
17
)
Combining these inequalities yields
ρ d u F ≧1 −x u x u ≧1−ρ d u F . (18)
The same mechanism allows for derivation of the other inequality.
These inequalities allow for finding lower and upper bounds on the segmentation areas. In any optimal solution to (10), x, a node u will always be classified as background if
ρ d u B ≤ 1 2
and as foreground if
ρ d u F ≤ 1 2 .
This property allows one to put bounds on the possible segmentations in an efficient way. Additionally, these bounds demonstrate that the l 1 method avoids the shrinking problem associated with Graph Cuts.
The above analysis also provides another property of the solution to (10). This property is that the solution for any nodes along the shortest path from F to B is fixed, regardless of the regularization method employed. Formally, if d u F +d u B =ρ −1 , meaning that node u lies on a shortest path between F and B then ρd u B =ρ(ρ −1 −d u F )=1−ρd u F , which implies that x u is fixed. The ambiguous region is illustrated in FIG. 4 for three images: A blank (uniform)
image, a weak boundary image and a natural image. Note that an 8-connected lattice was employed.
Various methods may be implemented for regularizing (10) to yield a unique solution, for example, the use of the other two norms (l 1 and l 2 ) as regularizers 903 for solving the degeneracy problem 904 . Employing the other two norms as regularizers offers one avenue for combining the l ∞ method with Graph Cuts or Random Walker.
l 1 Regularization 903 : one choice for regularization finds a solution which, among all solutions with l ∞ (x) minimum, also minimizes l 1 (x). This approach does not solve the degeneracy problem 904 , as illustrated with FIG. 3 . Here, it can be seen that all solutions minimizing l 1 (x) have l ∞ (x)=1 (the minimum), which means this solution may be obtained by other methods.
l 2 Regularization 903 : A second exemplary approach to solving the degeneracy problem of (10) 904 can be found by searching for the solution which has the minimum l ∞ value and minimizes l 2 , if this is rewritten as an optimization problem:
min x T A T C Ax, s.t. x F =1, x B= 0, w ij |x i −x j |≦ρ, ∀e ij ε E, (19)
which is a quadratic programming problem. Note that since it is assumed that the graph G is connected, the addition of boundary conditions x F =1 and x B =0 cause A T CA to be positive definite. If it is further assumed that there exists two different optimal solutions, x 1 and x 2 , then this implies that every x=θx 1 +(1−θx 2 ), ∀θε (0,1), ∀θε (0,1) is also an optimal solution. Such a situation would imply that A T CA is still singular with the foreground and background constraints, which is a contradiction. Therefore the solution obtained by l 2 regularization is unique. This l 2 regularization is used to generate segmentation results for the l ∞ method.
In order to solve the quadratic programming problem of (19), a conjugate gradient may be used based active set method. Results for l 2 regularized l ∞ minimization problems are obtained using this solver.
Exemplary results for all three seeded image segmentation methods discussed in this paper: Graph Cuts (l 1 minimization), Random Walker (l 2 minimization), and l ∞ minimization with l 2 regularization were determined. In all images, β is taken as 50 2 for the edge weight computation given in (5). The behavior of these methods on synthetic images has been investigated as well as results with real images.
Turning to the study the behavior of these methods on weak boundary images. The weak boundary images are known to be solvable by both the Random Walker and Graph Cuts methods. Here, it is shown that the regularized l ∞ minimization method shares this property. The segmentation results for a broken line are shown in FIGS. 5A-D . It can be seen that all three methods are able to complete the weak boundary. The minimum foreground and background segmentations allowed by l ∞ minimization for this image are also shown in FIG. 4( b ).
Referring to the dependency of segmentations on the seed locations; By its formulation, the Graph Cuts method is expected to be the least sensitive to seed placement, while the Random Walker method is expected to exhibit slightly more sensitivity to seed location. Since the l ∞ minimization method depends on the shortest path between the foreground and background seeds, a greater sensitivity to seed location might be expected. The experiment in FIG. 6 confirms that this is indeed the case. Although the segmentation from the l ∞ minimization is more affected by the seed placement, the segmentation is still qualitatively similar.
The effects of noise on the three methods has been compared. Uniform noise was added in the range [0, ¼] to the weak boundary image presented in FIGS. 5A-D . The results for this segmentation are given in FIGS. 7A-D . The l 1 method (Graph Cuts) is driven toward a small (minimal) cut as noise increases, while the l 2 method (Random Walker) is driven toward a segmentation resembling Voronoi cells. In contrast, the l ∞ method maintains its solution.
For real images, it can be seen from the results in FIGS. 8 Ai-Cv that the l ∞ minimization method (FIGS. 8 Ci-v) is able to give “tighter” segmentations than the Random Walker method (FIGS. 8 Bi-v) without suffering from the shrinking property of Graph Cuts (FIGS. 8 Ai-v). In order to shed more light on this case, FIG. 4C shows the ambiguous region in the l ∞ method for the image in FIG. 8 Ci. As shown in FIG. 4C , the minimum segmentation property of the l ∞ minimization places minimal foreground segmentation in some areas declared as background by the Graph Cut method, thus avoiding the shrinking problem.
Referring to FIGS. 4A-C , although the l ∞ algorithm produces a solution that may be achieved used other methods, the segmentation boundary must lie within a certain “ambiguous region” that is simple to compute. In these fig ures, the red region illustrates this “ambiguous region” in which the segmentation may take either a foreground or background label. Regardless of the regularizer, pixels inside the blue region must take a foreground label and pixels inside the green region must take a background label. Note that the blue and green regions always touch at a point that is halfway along the (weighted) shortest path between the foreground and background seeds. The saturated blue and green pixels indicate the foreground/background seed locations.
It is to be understood that the present invention may be implemented in various forms of hardware, software, firmware, special purpose processors, or a combination thereof. In one embodiment, the present invention may be implemented in software as an application program tangibly embodied on a program storage device. The application program may be uploaded to, and executed by, a machine comprising any suitable architecture.
Referring to FIG. 10 , according to an embodiment of the present invention, a computer system 1001 for seeded image segmentation using l ∞ minimization can comprise, inter alia, a central processing unit (CPU) 1002 , a memory 1003 and an input/output (I/O) interface 1004 . The computer system 1001 is generally coupled through the I/O interface 1004 to a display 1005 and various input devices 1006 such as a mouse and keyboard. The support circuits can include circuits such as cache, power supplies, clock circuits, and a communications bus. The memory 1003 can include random access memory (RAM), read only memory (ROM), disk drive, tape drive, etc., or a combination thereof. The present invention can be implemented as a routine 1007 that is stored in memory 1003 and executed by the CPU 1002 to process the signal from the signal source 1008 . As such, the computer system 1001 is a general purpose computer system that becomes a specific purpose computer system when executing the routine 1007 of the present invention.
The computer platform 1001 also includes an operating system and micro instruction code. The various processes and functions described herein may either be part of the micro instruction code or part of the application program (or a combination thereof) which is executed via the operating system. In addition, various other peripheral devices may be connected to the computer platform such as an additional data storage device and a printing device.
It is to be further understood that, because some of the constituent system components and method steps depicted in the accompanying figures may be implemented in software, the actual connections between the system components (or the process steps) may differ depending upon the manner in which the present invention is programmed. Given the teachings of the present invention provided herein, one of ordinary skill in the related art will be able to contemplate these and similar implementations or configurations of the present invention.
The seeded image segmentation given by the method given by FIG. 1 has been described which is based on the minimization of l q norms. It has been shown that two seeded image segmentation methods, Graph Cuts and Random Walker, correspond to the parameter choices of q=1 and q=2 in FIG. 1 . Another case of q→∞ proved to be segmentation based on a minimal Lipschitz extension. Although the solution of this problem is degenerate, it has been shown that it is possible to produce a minimal and maximal segmentation, depending on the choice of regularization. In order to solve the associated degeneracy problem, regularization with l 2 may be used. The general method is able to find “tighter” segmentations than the Random Walker method while not suffering from the “small cuts” problem associated with the Graph Cuts method.
Having described embodiments for a system and method for seeded image segmentation using l ∞ minimization, it is noted that modifications and variations can be made by persons skilled in the art in light of the above teachings. It is therefore to be understood that changes may be made in the particular embodiments of the invention disclosed which are within the scope and spirit of the invention as defined by the appended claims. Having thus described the invention with the details and particularity required by the patent laws, what is claimed and desired protected by Letters Patent is set forth in the appended claims. | A computer readable medium embodying instructions executable by a processor to perform a method for seeded image segmentation using l ∞ minimization, the method including providing an image comprising a set of pixels, wherein a foreground seed label is given for at least one pixel of the image and a background seed label is given for at least another pixel of the image, determining an affinity function for every pair of neighbor pixels, solving the l ∞ minimization, which assigns a probability to each pixel, labeling each pixel as foreground pixel or background pixel according to a threshold of the probability, and outputting the image including the segmentation labels. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The following U.S. Patent applications are hereby incorporated by reference in their entirety for their teachings:
[0002] U.S. Application No. 60/591,018 for Foundation module for anti-ram devices where subsurface clearances are minimal, by Richard Steven Adler and John Crawford, filed Jul. 26, 2004.
[0003] U.S. Application No. 60/600,955 for Anti-ram foundation pad, by Richard Steven Adler and John Crawford, filed Aug. 12, 2004.
[0004] U.S. Application No. 60/605,959 for RSA/K&C anti-ram foundation pad, by Richard Steven Adler and John Crawford, filed Aug. 30, 2004.
[0005] U.S. Application No.60/622,385 for RSA/K&C anti-ram foundation pad with attached surface elements, by Richard Steven Adler and John Crawford, filed Oct. 26, 2004.
[0006] U.S. Application No. 60/674,965 for RSA/K&C anti ram bollards and RSA/K&C anti-ram headknocker, by Richard Steven Adler and John Crawford, filed Apr. 25, 2005.
[0007] U.S. Application No. 60/679,547 for RSA/K&C anti-ram bollard pad extension sleeves with integral structural integrity, by Richard Steven Adler, John Crawford and George Heyward, filed May 9, 2005.
FIELD OF THE INVENTION
[0008] The present invention relates to the assembly and installation of bollard systems for use in protecting building and other structures from being rammed by vehicles. It also relates to the adaption of bollard systems to varying installation requirements, and the disguising of the bollards to make them appear to be part of a normal landscape around a building or structure.
BACKGROUND OF THE INVENTION
[0009] A well know activity of terrorists is to crash a vehicle loaded with explosives or incendiary material into a building or other structure, so as to inflict damage to the building or other structure, and to harm the people in the building or structure. Various bollard constructions and methods of installation have been proposed and utilized in the past. Typically these bollard installations required rather deep excavations, several feet or more, to receive the base for a group of bollards. Alternatively, individual bollards were anchored by boring deep holes to receive the lower end of the bollard.
[0010] With the increased threat of terrorism, it has become desirable, and to some extend even necessary, to provide bollard protection to existing buildings in a well developed urban or commercial area. Typically it is desirable to locate the bollards between the building or other structure and the adjacent streets or roadways. Quite often buried below the surface of the space between a building or other structure and the street are utilities such as gas, water, electric, and telephone or other communication lines and related components. Thus, to provide a deep excavation for the base of a bollard system is difficult if not impossible. While the underground utilities, could be moved to make way for the deep excavation for the base of a bollard system, to do so would be quite costly, and considerable construction time would be required. Such construction would not only most likely result in disruption of the utility services, but more so disrupts travel on the street and pedestrian traffic on the sidewalk between the building and the street.
[0011] It would therefor be desirable to provide a bollard system which would require very little or no excavation for the base of the bollard system, and which bollard system could be partially or completely preassembled and readily delivered to the installation site for placement and final assembly. It would be further desirable that the bollard system be readily adaptable to different terrain and installation requirements. For instance, it should be adaptable to installation on slopes, around corners, and in other none straight line applications. Further, it should meet installation requirements such as allowing for vents and access to underground vaults, and accommodating fire hydrants and street lighting poles. Further, it should provide for ramps for handicap access to the building or structure, and even for removal of one or more bollards to provide vehicle access to the building when occasionally needed.
SUMMARY OF THE INVENTION
[0012] In accordance with this invention, a bollard system is provided which requires very little or no excavation for the base of the bollard system, and which can be partially or fully assembled prior to bringing it to the installation site. The bollard system of this invention includes one or more bollards secured to a shallow mounting pad or base. The shallow mounting pad or base of the bollard system of this invention may be formed or constructed in various ways and of various materials. In all cases, the shallow mounting pad or base is designed to made of heavy materials, so as to have considerable mass.
[0013] The major benefit in the physics of the bollard system of this invention, is that the striking forces from the crash vehicle are transmitted from the bollard down to the shallow mount pad (5″ to 14″ in depth) in a way that is different from standard deep trench foundations (4′ to 6′). The shallow mount pad is pushed down onto the soil (horizontal force backwards) instead of into the soil (vertical force downwards) as in the case of deep trench foundations.
[0014] The shallow base system makes for a much more effective and efficient load transfer into the soil which reduces the overall volume of displacement of soil by the base, as compared to the standard deep trench foundation systems. The shallow base system of this invention also provides a more efficient foundational system.
[0015] One of the issues with the deep trench system is that the lateral compliance at the top of the trench is quite low: If there is no strong resistive force at the top of the trench, then there is a greater chance of more rotation of the bollard which would permit the crash vehicle to breach the system, thereby obviating the crash control device. In the shallow mount bollard system of this invention, the resistive forces are all at the base of the bollard (at the top of the trench) and therefore reduce the likelihood of the bollard rotating and vehicle breaching the security system.
[0016] The bollard system of this invention works as the crash vehicle strikes the bollard near its top edge translating the forces from that impact to the base of the bollard. The forces at the base of the bollard are transmitted to the foundation pad or base, and from there into the soil or concrete depending on what the unit is seated on. The resistance force is of the reverse order stated above.
[0017] The bollard system of this invention is able to become more shallow (14″ to 6.5″ to 3″) by controlling the compliance supplied by the foundation to resist the rotation at the base of the bollard. Specifically the bollard system of this invention can utilize a more shallow trench by more efficiently transmitting the loads to the support media (soil or concrete). The more efficient transfer of the impact load is also accomplished by the addition of either one, a group or all of the following enhancements: 1) a wider base; 2) a heavier base; 3) longer base (laterally and tying adjacent units together); 4) increasing the efficiency of the grillage; 5) stiffer base; 6) ability to place bollard in different locations in the base (for example placing the bollard at the back of the base makes the system weaker), 7) the addition of internal stiffeners both inside the tubes forming the base and inside the pipe forming the bollard, and 8) others.
[0018] While in the preferred embodiment of this invention the base or pad is rectangular, other shapes can be used, such as angled and curved bases, zigzags, and indented, so as to go around an appurtenance.
[0019] In the preferred embodiment of this invention the frame or grill of the base and the bollards are formed of structural steel members. The amount of weldment required to assemble the frame or grill of the base and the bollards is dependant upon the availability of stock or over the counter materials. If more stock or over the counter materials are usable and available then less weldment is required to connect pieces and create a stronger base grillage.
[0020] Another major benefit of the shallow trench system of this invention is realized in its accommodation of site constraints (such as not interfering with underground utilities, able to install at sites where there is limited access to underground excavation (presence of vaults, basements), not interfering with vegetation, etc.
[0021] The base or pad in a preferred embodiment or the bollard system of this invention is constructed using a series of structural tubes to form a grillage (ie. pipes, tubes, channels and sometimes angles) to produce rigidity of the pad or base against upheaval and torsion forces. The grillage is a framework for supporting the load imparted by the bollard. The framework means the tubes (or other structural steel elements) tied together to form the grillage. The base or pad is completed on site, by filling the shallow excavation and grillage with concrete to form a finished foundation unit. It is preferred that the concrete be in contact with the soil or existing concrete at the base of the excavation in order to improve the resistance of the lateral motion of the pad. The top surface of the pad is to be formed in such a way to support the materials forming the final finished appearance (non-structural stone pavers or tiles, etc.)
[0022] The shallow base or pad concept of this invention differs from the standard deep trench system because it only requires a simple replacement of area near the surface, thereby significantly reducing the interference with any existing underground objects at the site. Unlike a deep trench footing, detailed inspection of pre-existing underground conditions, are not required. With the standard trench, personnel inspectors and multiple tools are required to hold the trench open, issues also arise with rain water or other media spilling into the trench.
[0023] The physics of the interaction of the base or pad of the bollard system of this invention with supporting media (soil or concrete) is different than that of the deep trench system, in that the forces imparted by the pad or base are much less than the forces imparted by the deep trench foundation. This is partly due to the large support area of the pad as compared to the deep trench foundation—the vertical forces being carried by the bottom edge of the trench foundation and the horizontal forces being carried by the top few inches of the trench foundation in a deep trench foundation, as compared to the horizontal forces being provided by the frictional forces being between the pad and media over the entire area of the pad and the vertical forces between the pad and media being carried over the entire area of the pad. The area of the pad or base in the bollard system of this invention may be reduced by the addition of engineered stiffeners, tying adjacent pads together, larger section modulus parts, larger welds, etc.
[0024] Restated, the area of a deep trench foundation interacting with the media is significantly smaller than the area of the pad interaction with the media in the system of this invention, thus the forces transferred to the media are far less than the forces transferred by the trench footing to the media. The pad or base of this invention spreads the forces out while the deep trench footing concentrates the forces which require the trench footing to be massive and deep. The deep trench footing for comparable performance will always have to be more massive than the pad or base of this invention.
[0025] The pad or base of the bollard system of this invention is superior in design because it transmits the load more efficiently to the foundation (ground) than a deep trench design. Thus allowing a smaller device to absorb the same or greater amount of energy than a more onerous design.
[0026] The shallow pad or base of the bollard system of this invention supports the development of corner units with inherent advantages over a deep trench foundation. The shallow base of the system of this invention allows for complex geometry at corners, thereby facilitating ADA access and foot traffic by allowing bollards to be placed in an optimal pattern for pedestrian traffic without regard to the excavation needed to support the bollards. This is achieved by taking advantage of the flexibility in bollard placement offered by the grillage concept that allows the bollards to be placed anywhere in the grillage. Whereas with deep trench footing, the bollards necessarily need to be lined up with the trench itself. In order for the deep trench to support out of line placement of bollards, it would have to be the full width of the bollard pattern whereas only an excavation of the shape of that pad needs to be made in accordance with this invention.
[0027] The flexibility of the bollard system of this invention permits the extension of a pad in any one direction for any unique situation for the bollard to be supported by the pad, but not beyond the pad. This is achieved by extending a tube connected to the grillage in any desired direction and placing (anchoring) a bollard in the tube.
[0028] In certain situations, site encumbrances may not allow a pad or base to be used where it is desirable to place one or more bollards. Extending one or more horizontal connector tubes between spaced pads achieves the necessary anti-ram capability without requiring additional excavation for the pad itself. In a specific embodiment, a connector tube, either above or below ground, can be secured at its ends to the grillage of two adjacent pads with the ends of one or more bollards placed in vertical holes formed in the connector tube. The physics behind this inventive concept is that the torsional rigidity of the connector tube is being used to resist the motion of the bollard, instead of upheaval or moment resistance of the tube used in the standard pad design. That is, when a vehicle strikes the bollard in the conventional design the tube supporting the bollard on axis with the impact is the tube that resists the motion of the bollard using its moment capacity, while in this alternate construction, the tube resists the motion of the bollard with its torsional capacity, bending not twisting.
[0029] Another variation of this invention provides removable units in which the bollard is temporarily removed for access through the on-center spacing and then replaced for its anti-ram purpose. The method to achieve this without a fixed bottom weld is the addition of an extra thick steel sleeve connected to the base of the grillage, with the bollard being slipped into and out of the sleeve. Additional bolts or a variation of locking mechanisms provide security to prevent unauthorized personnel from removing the removable bollard.
[0030] When using the shallow base of pad system of this invention, it may be necessary to place the pad over an air vent or access open to a underground space. To accommodate this need, the grillage is formed to provide an open space located over the air vent or access opening. A form is provided around the open space, such that when concrete is introduced into the grillage, it does not enter the open space. Once the base of the pad system is completed, the usual grate or grill can be placed over the opening.
[0031] While it is desirable in accordance with this invention to have the pad extend further in the direction of expected impact, that is on the opposite side of the bollard from the side of impact, than on the side of impact, some applications may require a reversal of the extension. For instance, if it becomes necessary to move the bollards farther away from the road, that is closer to the building being protected, a bollard unit in accordance with this invention may be lifted, rotated 180 degrees and replaced. This rotation will place the bollards closer to the building and farther away from the road. The bollard system of this invention also makes possible the temporary removal of the bollards and the supporting base. For instance, if it becomes desirable to access something under the bollards, the bollards and connected base may be lifted and temporarily removed. This would not be feasible with a deep trench bollard system.
[0032] The bollard system of this invention does not lend itself to the installation of a single bollard, since without an extended base or pad, there is not sufficient resistance to stop the rotation of the pipe bollard. However, a feature of this invention is to provide a single bollard with a supporting pad, such that if a single bollard is damaged in a row of bollards, the damaged bollard and its supporting pad may be cut out of the row of bollards and the supporting pad of the single replacement bollard secured to supporting pads of the adjacent bollards.
[0033] In its most basic form the bollard system of this invention would have its base or pad formed of a continuous flat piece of steel with holes cut out for the bollards. The plate would need a minimum depth 5″ to qualify as a DOS rated system. The cross pieces are inherent in the continuous plate. Still another basic configuration of the bollard system of this invention is to bolt separate thick pieces of steel to continuous cross plates, and to have the bollard set inside that construction. Again, 5″ thick steel would be required to have two plates 5″ apart.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] FIG. 1 is a perspective view of the anti-ram system of this invention installed alongside the edge of a sidewalk, prior to the pad being covered with a landscaping surface;
[0035] FIG. 2 is a perspective view of the anti-ram system of this invention as shown in FIG. 1 , with a landscaping surface applied over the pad, and with the bollards covered by ornamental and functional items;
[0036] FIG. 3 shows an embodiment of this invention with four bollards mounted on the framework for the pad or base of the anti-ram system;
[0037] FIG. 4 , shows the embodiment of this invention shown in FIG. 3 , with a rebar cage surrounding the framework for the pad or base;
[0038] FIG. 5 is a top plan view of the steel layout for the base of a set of three bollards in accordance with a preferred embodiment of this invention;
[0039] FIG. 6 is a side elevation view of the steel layout of FIG. 5 ;
[0040] FIG. 7 is a top plan view of the steel layout shown in FIG. 5 , showing in addition the layout of rebars forming a grill or cage around the rebars;
[0041] FIG. 8 is a side elevation view of the steel and rebar layout shown in FIG. 7 ;
[0042] FIG. 9 is an end elevation view of the steel and rebar layout shown in FIG. 7 ;
[0043] FIG. 10 is an end elevation view of the steel layout of FIG. 5 ;
[0044] FIG. 11 is an end plate detail of the steel layout of FIG. 5 ;
[0045] FIG. 12 is a cover strip shown encircling the bollards in FIGS. 6 and 8 - 10 ;
[0046] FIG. 13 is a top plan view of the steel layout for the base of a set of three bollards in accordance with a second preferred embodiment of this invention;
[0047] FIG. 14 is a detailed top plan view of the steel layout encircled by the line A-A in FIG. 13 ;
[0048] FIG. 15 is a typical section view of the steel layout shown in FIG. 12 ;
[0049] FIG. 16 is a top elevation view similar to FIG. 13 . Showing the steel and rebar layout;
[0050] FIG. 17 is a typical elevation view of the steel and rebar layout shown in FIG. 16 ;
[0051] FIG. 18 is a cross-sectional view of the longitudinal tubular member located adjacent to the bollards in FIG. 13 ;
[0052] FIG. 19 is a cross-sectional view of the longitudinal channel member located at the rear end of the transversely extending members in FIG. 13 ;
[0053] FIG. 20 is a detail of a front stiffener as used in the transversely extending member shown in FIG. 13 ;
[0054] FIG. 21 is a detail of a rear stiffener as used in the transversely extending member shown in FIG. 13 ;
[0055] FIG. 22 is a cross-sectional view of the support arrangement for the bollard tube, including a solid circular steel bar in the center of the tube;
[0056] FIG. 23 is a top elevation view showing the layout of the steel members for forming the framework for a pad designed to support bollards at a corner:
[0057] FIG. 24 is a side elevation view of the corner pad and bollards shown in FIG. 23 ;
[0058] FIG. 25 is a top elevation similar to FIG. 23 showing the location of rebars used in the corner;
[0059] FIG. 26 is a side elevation view of the corner pad and rebars as shown in FIG. 25 ;
[0060] FIG. 27 is a cross-section view showing a stiffener place in the end of the transversely extending members shown in FIG. 23 ;
[0061] FIG. 28 is a cross-sectional view of the support arrangement for a bollard in the framework shown in FIG. 23 ;
[0062] FIG. 29 is a detailed top plan view of the steel frame layout for a pad in accordance with this invention wherein the bollards are removable so as to provide access to the protected structure;
[0063] FIG. 30 is a side elevation view of the steel frame shown in FIG. 29 , showing the reinforced steel socket provided for receiving the lower end of a bollard;
[0064] FIG. 31 is a detailed top plan view similar to FIG. 29 showing the placement of the rebars on the steel frame;
[0065] FIG. 32 is side sectional view of the steel frame and bollard shown in FIG. 29 ;
[0066] FIG. 33 is an end view of the steel frame and bollard shown in FIG. 29 ;
[0067] FIG. 34 is an end sectional view of the frame reinforce steel socket and bollard as shown in FIG. 29 :
[0068] FIG. 35 is a cross-section view showing a stiffener place in the end of the transversely extending members shown in FIG. 29 ;
[0069] FIG. 36 show an arrangement including a bolt for securing a bollard in a socket as shown in FIG. 29 ;
[0070] FIG. 37 is a cross-sectional view of a typical end section of the steel frame shown in FIG. 29 ;
[0071] FIG. 38 is an detailed cross-sectional view of the socket and locking or securing arrangement for a bollard mounted in the steel frame shown in FIG. 29 ;
[0072] FIG. 39 is a cross-sectional view shown the enclosure provide for the locking or securing arrangement shown in FIG. 36 ;
[0073] FIG. 40 is a perspective view of still another embodiment of this invention;
[0074] FIG. 41 shows still another embodiment of this invention, wherein the pad or base is surface mounted;
[0075] FIG. 42 is a perspective view of a corner or curved bollard system in accordance with this invention wherein the base is formed with a ramp for handicap access;
[0076] FIG. 43 is a perspective view of a steel frame formed for the base of a bollard system of this invention which is intended for placement on a slope; and
[0077] FIG. 44 is a perspective view of an embodiment of this invention wherein an opening is left is the base of the bollard system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0078] Referring to FIG. 1 , shows an embodiment of the anti-ram system of this invention installed in a shallow trench alongside a sidewalk. The top surface 10 of the base or pad of the anti-ram system is shown recessed below the desired grade level. As shown in FIG. 2 , a landscaping surface, such as grass 12 is placed over the top surface 10 of the base or pad. As further shown in FIG. 2 , ornamental or functional objects are placed over the bollards 14 shown in FIG. 1 . Such objects include lamp posts 16 , waste container 18 , ornaments 20 , and a seat and shelter 22 . The ornamental and functional items disguise the presence of the bollards of the anti-ram system.
[0079] FIG. 3 shows an embodiment of this invention with four bollards 14 , mounted on the steel framework 23 for the pad of the anti-ram system. The framework 23 includes transversely extending tubular members 24 , longitudinally extending tubular members 26 , and longitudinally extending angle members 28 . In a preferred embodiment of this invention, the tubular members 24 and 26 have a rectangular cross-section, such that they form a generally planar upper and lower surface for the pad. The longitudinally extending tubular members 26 are welded to the sides of the transversely extending tubular members 24 . Depending on the strength requirements of a particular anti-ram system, the welds can be fillet welds or full penetration welds on all four sides of the tubular members 26 . Similarly, the longitudinally extending angle members 28 are welded to the sides of the tubular members 24 by either full penetration or fillet welds. Alternatively, angular notches can be cut in the transversely extending tubular members 24 for the longitudinally extending angle member to pass through, in which case the angle member may be formed as one continuous piece. Holes are provided in the transversely extending tubular members 24 to receive the cylindrical bollards 14 . Again, the cylindrical bollards are secured to the tubular members 24 by fillet or full penetrations welds are both the upper and lower surfaces of the tubular members 24 . Apertures 30 are provided in both tubular members 24 and 26 , such that they may be filled with a material such as concrete, to add strength and weight to the base or pad.
[0080] FIG. 4 , which is similar to FIG. 3 , shows a rebar cage, or grillage 30 placed around the steel framework 23 . The rebar cage includes an upper portion on top of the tubular members 24 and 26 and a lower portion under the tubular members 24 and 26 . The rebars forming the cage 30 , are welded to the tubular member 24 and 26 .
[0081] FIG. 5 shows a top plan view of a framework for a typical set of three bollards, and FIG. 6 shows a side elevation of the same framework constructed in accordance with this invention. FIG. 7 shows an elevation view of a rebar cage or grillage secured to the framework shown in FIG. 5 . FIG. 8 is a typical side section view of the rebar cage and framework shown in FIG. 7 , and FIG. 9 is a typical front end section view, while FIG. 10 is a typical rear end section view. FIG. 11 is a cross-sectional detailed view of an end plate secure in the tubular member 24 . A gap is provided in the end plate to provide for the filing of th tubular member with a material such as concrete. FIG. 12 is a detailed cross-section of one of the cover strips 32 provided on the bollards 14 . FIGS./ 5 - 12 are representative of a base or pad system in accordance with this invention which requires the provision of a excavation approximately 14 inches deep. The steel framework have a height of approximately 10 inches, the rebar cage adding approximately ½ inch to the height, and the encapsulating concrete adding another 1 and ½ inch, for a total of 12 inches.
[0082] FIGS. 13-22 are similar to FIGS. 5-12 in showing details of a second preferred embodiment of this invention. In this embodiment the base or pad is considerable thinner than that shown in FIGS. 5-12 . In this embodiment the overall height of the pad could be only 6 and ½ inches, the steel frame having a height of 5 inches, with the rebar being located mid-height in the steel frame, rather that on the top and the bottom. The Concrete adds 1 and ½ inches to the height of the pad.
[0083] Referring to FIGS. 23-28 , it can be seen that by forming triangles with the transversely and longitudinally extending tubular members, it is possible to form a curved line of bollards.
[0084] Referring to FIG. 40 , two sets of five bollard pads 32 , are shown spaced apart by a gap 34 . Before the pads are filed with concrete, a pair of pipes are placed within the pads, such that post tensioning members can be passed through the pipes to secure the two sets of bollard pads 32 to each other. Of course, any number of pads could be placed in alignment and secure by the post tensioning members.
[0085] Referring to FIG. 41 , the bollard system of this invention may be formed as a unit to be place on a surface for temporary bollard protection. The bottom surface is formed as a high friction surface, so as to resist sliding when an impact is received by the bollards.
[0086] Referring to FIG. 43 a perspective view of a steel frame formed for the base of a bollard system of this invention is shown, which is intended for placement on a slope: The bollards are secured to the base at an angle, such that when the base is place on a slope, the bollards will be vertical.
[0087] FIG. 44 shows an embodiment of this invention wherein an opening is left is the base of the bollard system to provide for an opening, such that when a grate is installed over the opening, an open space below the base is ventilated through the opening.
[0088] While only one embodiment of the invention has been shown, it should be apparent to those skilled in the art that what has been described is considered at present to be a preferred embodiment of the anti-ram system and method of installation of this invention. In accordance with the Patent Statute, changes may be made in the anti-ram system and method of installation of this invention without actually departing from the true spirit and scope of this invention. The appended claims are intended to cover all such changes and modifications which fall in the true spirit and scope of this invention. | An anti-ram system and method of construction having a shallow mounted base pad from which extend a plurality of bollards. Very little or only a shallow excavation is required for the base of the bollard system, which can be partially or fully assembled prior to bringing it to the installation site. The shallow mounting pad or base of the bollard system of this invention may be formed or constructed in various ways and of various materials, and in various configurations. The shallow mounting pad or base is constructed so as to have considerable mass. | 4 |
PRIORITY CLAIM
This application claims priority to U.S. Provisional Patent Application Ser. No. 60/450,804, filed on Feb. 28, 2003, entitled “TI MAC Sublayer Proposal for IEEE 802.15 Task Group 3a In Support of Frequency Hopping PHY,” incorporated herein by reference.
BACKGROUND
A network is a system that allows communication between members of the network. Wireless networks allow such communications without the physical constraints of cables and connectors. Recently, wireless local area networks (a local area network is a computer network covering a local area such as an office or a home) with ranges of about 100 meters or so have become popular. Wireless local area networks are generally tailored for use by computers, and as a consequence such networks provide fairly sophisticated protocols for establishing and maintaining communication links. Such networks, while useful, may be unsuitably complex and too power-hungry for electronic devices of the future.
A wireless personal area network is a network with a more limited range of about 10 meters or so. With the more limited range, such networks may have fewer members and require less power than local area networks. The IEEE (Institute of Electrical and Electronics Engineers) is developing a standard for wireless personal area networks. The IEEE 802.15.3 standard specifies a wireless personal area medium access control (MAC) protocol and a physical (PHY) layer that may offer low-power and low-cost communications with a data rate comparable to that of a wireless local area network. The standard coins the term “piconet” for a wireless personal area network having an ad hoc topology of devices coordinated by a piconet coordinator (PNC). Piconets form, reform, and abate spontaneously as various electronic devices enter and leave each other's proximity. Piconets may be characterized by their limited temporal and spatial extent. Physically adjacent devices may group themselves into multiple piconets running simultaneously.
The IEEE 802.15.3a task group is developing a new PHY layer operating in an ultra wide band (UWB) and providing very high data rates (in the order of 100 Mbps). Currently this PHY layer is based on frequency hopping (FH) orthogonal frequency division multiplexing (OFDM), whereby the OFDM symbols of a data packet are successively sent in a pre-ordered sequence of frequency bands comprising all or part of the UWB frequency range. There may be a variety of such sequences, which are referred to as frequency hopping (FH) sequences herein but may be given other terms in the final standard or the technical literature. The frequency hopping nature of the PHY makes simultaneously operating piconets susceptible to mutual interference. The draft IEEE standard proposes that each PNC selects an FH sequence for use by the devices in its piconet for data transmission. However, this creates a significant likelihood of repeated collisions between adjacent piconets that happened to have chosen the same FH sequence. Accordingly, a randomization mechanism for avoiding persistent interference and hence improving network performance (in terms of user throughput and delay) is desired for the robust operation of ad hoc piconets and other wireless personal area networks in general.
SUMMARY
Accordingly, there is disclosed herein wireless personal area networks with frequency hopping and rotation sequences. A rotation sequence is a sequence of frequency hopping sequences. Just as there are a variety of frequency hopping sequences, there are a variety of rotation sequences. A rotation sequence is identified by a rotation index while a frequency hopping sequence is identified by a hopping index. In one embodiment, a method of wireless communication is provided, the method including: transmitting a beacon frame by a piconet coordinator that specifies a rotation index and hopping index; receiving the beacon frame by a device associated with or to be associated with the piconet coordinator; extracting the rotation index and hopping index by the MAC of the recipient device and communicating them to the PHY for transmission and reception in a current superframe; missing a subsequent beacon frame by a recipient device; and using the rotation index and hopping index previously received to determine a current frequency hopping sequence for a current superframe following the missed beacon frame. Each beacon frame includes a field that specifies a rotation sequence of frequency hopping sequences, and further includes a field that indicates a frequency hopping sequence to be used in the current superframe. The inclusion of the frequency hopping sequence enables devices to find out the frequency hopping sequence in use for the current superframe in case they have not received previous beacons.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the present invention can be obtained when the following detailed description is considered in conjunction with the following drawings, in which:
FIG. 1 shows two overlapping piconets;
FIGS. 2A-2E show a framing structure for piconet communications;
FIG. 3 shows an information element for communicating rotation and frequency hopping information in a beacon; and
FIG. 4 shows a block diagram of an illustrative piconet member device.
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.
DETAILED DESCRIPTION
FIG. 1 shows a number of electronic devices that have cooperated to form two piconets 102 , 114 . Piconets have an ad hoc topology that results from the spontaneous combinations of devices that are in close proximity. Devices 104 - 112 are members of piconet 102 , and devices 116 - 120 are members of piconet 114 . Some or all of the devices that can participate in piconet communications can also operate as the piconet coordinator (“PNC”). In FIG. 1 , device 108 is operating as the PNC for piconet 102 , while device 118 is operating as the PNC for piconet 118 . PNC devices 108 , 118 broadcast beacon frames to facilitate the communications of their respective piconet members. The effective range of the beacons (and hence the effective boundary of the piconets) is shown by broken lines 102 and 114 . Note that devices in one piconet (e.g., device 106 ) may be subject to radio interference in the other piconet.
In the configuration of FIG. 1 , it is assumed that the piconets are operating independently. Nevertheless, such piconets may frequently synchronize with each other in starting a frame transmission. This is because the contention access method, referred to as carrier sense multiple access with collision avoidance (CSMA/CA), tends to force devices in overlapping piconets to start their transmissions after the end of a current transmission that they can hear. Such synchronization leads to mutual interference and hence repeated collisions between overlapping piconets operating on the same frequency hopping sequence, which in turn causes serious degradation in data throughput and access delay performance.
To combat interference, the piconets 102 , 114 ( FIG. 1 ) may employ different frequency hopping sequences so that they do not use the same frequency bands most of the time. To this end, a given piconet will not use the same hopping sequence indefinitely, but will employ different hopping sequences for different superframes. The hopping sequence to be used for a particular superframe by the devices in that piconet is provided in the beacon sent by the PNC of the piconet. To enable devices that miss one or more beacons to continue their transmission and reception without interruption, as is important for audio/video streaming, the hopping sequences to be used in successive superframes are pre-ordered into a rotation sequence which is also identified in each beacon. More details are given below in connection with FIG. 3 .
FIGS. 2A-2E show an illustrative framing structure. In each of these figures, the time axis increases from right to left, so that the rightmost portion of the figure corresponds to the earliest portion of the communications sequence, and the leftmost portion corresponds to the latest portion of the sequence. The figures are not to scale.
FIG. 2A shows a sequence of superframes that includes superframes 202 , 204 , and 206 , which occur in order from right to left. As shown in FIG. 2B , each superframe begins with a beacon frame 210 , which is transmitted by the PNC. The beacon 210 is followed by an optional contention access period (“CAP”) 212 . During the CAP, the piconet member devices may attempt communications using a CSMA/CA protocol. The optional CAP 212 is followed by a channel time allocation period (“CTAP”) 214 , which is composed of channel time allocations (“CTAs”) 216 - 226 . Any of the CTAs in the channel time allocation period 214 may be management CTAs (“MCTAs”) (e.g., MCTAs 216 , 218 ). CTAs are allocated for communications from a specified source device to a specified destination device or a group of destination devices. The length of the CAP and the allocations of the CTAs are specified in the beacon frame.
The member devices may request channel time allocations by sending management frames to the PNC. Depending on parameters specified by the beacon, the management frames may be sent during the CAP or during MCTAs. Similarly, data frames may be exchanged by member devices during the CAP or CTAs.
FIG. 2C shows the frame format for each frame sent during the superframe (including the beacon frame, any management frames, data frames, and acknowledgment frames). Each frame includes a medium access control (“MAC”) header 230 , and a MAC frame body 232 . Each is described in turn below.
The MAC header 230 includes a frame control field 234 , a piconet identifier field 236 , a destination identifier field 238 , a source identifier field 240 , a fragmentation control field 242 , and a stream index field 244 . The frame control field 234 may include a field that specifies the protocol version, a field that specifies the frame type (e.g., beacon, data, acknowledgment), a field that specifies whether the frame is security protected, a field that indicates the acknowledgment policy (e.g., none, immediate, delayed), a field that indicates whether the frame is a “retry” (i.e., a re-transmission of an earlier frame), and a field that indicates whether additional frames from the source will follow in the current CTA. The piconet identifier field 236 specifies a unique 16-bit identifier for the piconet. The destination identifier field 238 specifies an 8-bit piconet member device identifier for the device to which the frame is directed (special values may be used for broadcast or multicast frames). Similarly, the source identifier field 240 specifies the 8-bit piconet member device identifier for the device which is transmitting the frame. The fragmentation control field 242 includes fields that are used for reconstructing large data units that have been split into fragments small enough to be sent in MAC frames. The fragmentation control field 242 may include a field specifying a data unit number, a field specifying the current fragment number, and a field specifying the total number of fragments in the data unit. The stream index field 244 may specify a stream identifier for isochronous streams (which produces data in a periodic fashion) and asynchronous traffic (which may arrive for transfer any time).
The MAC frame body 232 includes a payload field 246 , and a frame check sum field 248 . The payload field 246 is a variable length field that carries the information that is to be transferred. Finally, the frame check sum field 248 contains a 32-bit cyclic redundancy code (“CRC”) value that is calculated over the entire payload field 246 . Corruption of the payload may be detected by comparing the frame check sum field value to a CRC value calculated over the received payload field by the MAC functionality of the receiver.
FIG. 2D shows the payload field 246 for a beacon frame. The beacon frame payload field 246 includes a piconet synchronization parameters field 250 , and one or more information element fields 252 , 254 . The piconet synchronization parameters field 250 may include a field that specifies a time token (a 48-bit rollover counter that increments for each beacon), a field that specifies the duration of the superframe, a field that specifies the end of the contention access period, a field that specifies a maximum transmit power for piconet member devices, a field that specifies the piconet mode, a field that specifies the PNC response time, and a field that specifies the 8-byte device address for the PNC.
The information element fields 252 - 254 may be used to provide various piconet events and parameters including: PNC capabilities, a list of piconet member devices and their capabilities, a list of channel time allocations, CTA properties, device wake-up requests, shutdown notifications, piconet parameter changes, PNC handovers, transmit power control values, and identifiers of overlapping piconets. FIG. 2E shows the structure of a generic information element 260 . Every information element includes an element identifier field 262 that specifies the information element type (e.g., a list of channel time allocations), a length field 264 that specifies the length of the information element payload field in bytes, and an information element payload field 268 that contains information in a format specific to the information element type.
Before reaching FIG. 3 , a further discussion of the rotation of frequency hopping sequences is appropriate. Each frame sent during the superframe may be divided into channel symbols. Channel symbols are specific to the modulated signal and are only indirectly related to the fields in the frame structures described above. Each channel symbol carries some amount of digital data that is determined by the capacity of the channel and the specific modulation scheme employed. In one embodiment, the devices employ orthogonal frequency division multiplexing (OFDM) modulation to communicate data bits on each of multiple frequencies during a channel symbol period. Thus, the OFDM channel symbols are at least N sample periods long, where N is the number of frequency bins used to carry one OFDM symbol data. In other modulation schemes, the channel symbols may also be of a predetermined length or one or more sample periods.
A frequency hopping sequence is a sequence of frequencies bands (“channels”) to be used by devices communicating during a superframe. Starting with the beginning of each frame (or with the beginning of the frame preamble if there is one) in the superframe, the devices transmit each channel symbol in a different channel as specified by the hopping sequence. The first channel symbol will be sent in the channel specified by the first element of the hopping sequence, the second channel symbol will be sent in the channel specified by the second element of the hopping sequence, and so on. The sequence of channels may be selected from a pool of possible hopping sequences. In one embodiment, the following pool of hopping sequences is employed:
HS — 1={Channel — 1, Channel — 2, Channel — 3, Channel — 1, Channel — 2, Channel — 3, . . . (repeats)} HS — 2={Channel — 3, Channel — 1, Channel — 2, Channel — 2, Channel — 1, Channel — 3, . . . (repeats)} HS — 3={Channel — 2, Channel — 3, Channel — 1, Channel — 3, Channel — 2, Channel — 1, . . . (repeats)} HS — 4={Channel — 3, Channel — 2, Channel — 1, Channel — 1, Channel — 3, Channel — 2, . . . (repeats)}
The frequency hopping sequence may change from superframe-to-superframe. Each superframe uses one hopping sequence. A rotation sequence is used to specify the order in which the hopping sequences are employed. The rotation sequence may be selected from a pool of possible rotation sequences. In one embodiment, the following pool of rotation sequences is employed:
RS — 1={HS — 1, HS — 1, HS — 1, HS — 3, HS — 3, HS — 3, . . . (repeats)} RS — 2={HS — 2, HS — 1, HS — 1, HS — 3, HS — 3, HS — 4, . . . (repeats)} RS — 3={HS — 3, HS — 1, HS — 1, HS — 3, HS — 3, HS — 1, . . . (repeats)} RS — 4={HS — 4, HS — 1, HS — 1, HS — 3, HS — 3, HS — 2, . . . (repeats)} RS — 5={HS — 1, HS — 2, HS — 1, HS — 3, HS — 4, HS — 3, . . . (repeats)} RS — 6={HS — 2, HS — 2, HS — 1, HS — 3, HS — 4, HS — 4, . . . (repeats)} RS — 7={HS — 3, HS — 2, HS — 1, HS — 3, HS — 4, HS — 1, . . . (repeats)} RS — 8={HS — 4, HS — 2, HS — 1, HS — 3, HS — 4, HS — 2, . . . (repeats)} RS — 9={HS — 1, HS — 3, HS — 1, HS — 3, HS — 1, HS — 3, . . . (repeats)} RS — 10={HS — 2, HS — 3, HS — 1, HS — 3, HS — 1, HS — 4, . . . (repeats)} RS — 11={HS — 3, HS — 3, HS — 1, HS — 3, HS — 1, HS — 1, . . . (repeats)} RS — 12={HS — 4, HS — 3, HS — 1, HS — 3, HS — 1, HS — 2, . . . (repeats)} RS — 13={HS — 1, HS — 4, HS — 1, HS — 3, HS — 2, HS — 3, . . . (repeats)} RS — 14={HS — 2, HS — 4, HS — 1, HS — 3, HS — 2, HS — 4, . . . (repeats)} RS — 15={HS — 3, HS — 4, HS — 1, HS — 3, HS — 2, HS — 1, . . . (repeats)} RS — 16={HS — 4, HS — 4, HS — 1, HS — 3, HS — 2, HS — 2, . . . (repeats)} RS — 17={HS — 1, HS — 1, HS — 2, HS — 4, HS — 3, HS — 3, . . . (repeats)} RS — 18={HS — 2, HS — 1, HS — 2, HS — 4, HS — 3, HS — 4, . . . (repeats)} RS — 19={HS — 3, HS — 1, HS — 2, HS — 4, HS — 3, HS — 1, . . . (repeats)} RS — 20={HS — 4, HS — 1, HS — 2, HS — 4, HS — 3, HS — 2, . . . (repeats)} RS — 21={HS — 1, HS — 2, HS — 2, HS — 4, HS — 4, HS — 3, . . . (repeats)} RS — 22={HS — 2, HS — 2, HS — 2, HS — 4, HS — 4, HS — 4, . . . (repeats)} RS — 23={HS — 3, HS — 2, HS — 2, HS — 4, HS — 4, HS — 1, . . . (repeats)} RS — 24={HS — 4, HS — 2, HS — 2, HS — 4, HS — 4, HS — 2, . . . (repeats)} RS — 25={HS — 1, HS — 3, HS — 2, HS — 4, HS — 1, HS — 3, . . . (repeats)} RS — 26={HS — 2, HS — 3, HS — 2, HS — 4, HS — 1, HS — 4, . . . (repeats)} RS — 27={HS — 3, HS — 3, HS — 2, HS — 4, HS — 1, HS — 1, . . . (repeats)} RS — 28={HS — 4, HS — 3, HS — 2, HS — 4, HS — 1, HS — 2, . . . (repeats)} RS — 29={HS — 1, HS — 4, HS — 2, HS — 4, HS — 2, HS — 3, . . . (repeats)} RS — 30={HS — 2, HS — 4, HS — 2, HS — 4, HS — 2, HS — 4, . . . (repeats)} RS — 31={HS — 3, HS — 4, HS — 2, HS — 4, HS — 2, HS — 1, . . . (repeats)} RS — 32={HS — 4, HS — 4, HS — 2, HS — 4, HS — 2, HS — 2, . . . (repeats)}
Piconets employing different rotation sequences will not collide repeatedly with one another on the same hopping sequence even if they become synchronized, and hence their mutual interference is greatly reduced. Even if overlapping piconets happen to use the same rotation sequence, they are not likely to be operating on the same hopping sequence for a prolonged period because the lengths and boundaries of their superframes are usually not identical. Both the hopping sequence pool and the rotation sequence pool may be designed to provide a minimum cross-correlation with other pool members given the size of the pool and the non-repeating length of the sequences as constraints.
The use of frequency hopping sequence rotation may offer other benefits specific to the piconet communications protocol. For example, it is expected that piconet member devices will occasionally miss beacons. Without the use of a specified rotation sequence, the loss of even a single beacon could cause a member device to lose track of the hopping sequence and have to drop out of the piconet. However, with knowledge of the specified rotation's sequence the piconet member devices are aware of the hopping sequence and may be able to participate in the superframe communications without having received the beacon.
FIG. 3 shows one embodiment of a frequency hopping sequence rotation information element 302 . The information element includes an element identifier field 262 that specifies that the information element contains frequency hopping sequence rotation information. Also included is the length field 264 which may indicate that a payload of two bytes long follows. This payload is the information element payload and includes a hopping index field 304 and a rotation index field 306 . The hopping index field 304 specifies the hopping sequence to be used during the current superframe, i.e., the current position in the rotation sequence. The rotation index field 306 specifies the rotation sequence currently being used by the piconet. Each of the fields 304 and 306 may be one byte long. The hopping index field 304 may be incremented in each beacon, rolling over to the initial value after the end of the rotation sequence is reached.
Each beacon may be required to include a frequency hopping sequence rotation information element immediately after the channel time allocation information element(s). By monitoring the frequency hopping sequence rotation information element, the piconet member devices can determine not only the hopping sequence for the current superframe, but also the hopping sequences for future superframes.
The rotation sequence may be changed by the PNC using the piconet parameter change procedure provided in the IEEE 802.15.3 standard. One embodiment is to treat a rotation sequence as a channel defined in that standard, and hence use the piconet parameter change procedure to change the channel to change the rotation sequence. Generally speaking, the parameter change procedure involves the inclusion of the piconet parameter change information element in a predetermined number of beacons before the change takes effect. This procedure ensures enough notice for all member devices to be alerted to the change even if a tolerable number of beacons are missed.
FIG. 4 shows a block diagram of an illustrative piconet member device. Piconet frames are transmitted and received via an antenna 402 . (At the frequencies of interest, the antenna may be implemented as a trace on a printed-circuit card.) A switch 404 couples the antenna 402 to an amplifier 406 during receive periods. The amplifier 406 may be followed by filter and frequency down-conversion circuitry (not specifically shown). An analog to digital converter 408 converts the receive signal into digital form for processing by a digital processor 410 . The digital processor 410 may be implemented by hardware, firmware, or a combination of them. It performs demodulation and decoding of the receive signal to obtain receive data, and may further perform modulation and encoding of transmit data to produce a digital transmit signal. There may be another digital processor (not shown in FIG. 4 ) to handle MAC layer functions. A digital to analog converter 412 converts the digital transmit signal to an analog transmit signal, which is amplified by driver 414 and provided by switch 404 to antenna 402 during transmit periods. Frequency up-conversion and filter circuitry may be provided between the digital-to-analog converter 412 and the driver 414 .
The operation of digital processor 410 may be partly controlled by software stored in memory 416 . (The term “software” is intended to include firmware and processor instructions of any other type.) The software may include device drivers 418 to facilitate the communications between applications 420 and the digital processor 410 . The digital processor 410 may include, or interact with, support hardware (not specifically shown) such as a keyboard, keypad, buttons, dials, a pointing device, a touch sensitive screen, an alphanumeric or graphics display, lights, a printer, speakers, a microphone, a camera, and/or other mechanisms for interfacing with a device user. Alternatively, or in addition, the support hardware may include nonvolatile information storage, a network interface, a modem, a sound card, a radio/television tuner, a cable/satellite receiver, or other electronic modules helpful to the device's purpose.
Numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. For example, different pools of hopping sequences and rotation sequences may be used. The pools may be significantly larger than the examples provided herein. It is intended that the following claims be interpreted to embrace all such variations and modifications. | Wireless personal area networks with frequency hopping and rotation of the frequency hopping sequences. In one embodiment, a method of wireless communication is provided, the method including: transmitting a beacon frame by a piconet coordinator that specifies a rotation index and hopping index; receiving a beacon frame by a device associated with or to be associated with the piconet coordinator; extracting the rotation index and hopping index by the MAC of the recipient device and communicating them to the PHY for transmission and reception in a current superframe; missing a subsequent beacon frame by a recipient device; and using the rotation index and hopping index previously received to determine a current frequency hopping sequence for a current superframe following the missed beacon frame. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
The application claims priority of U.S. provisional application No. 60/908,359 filed Mar. 27, 2007.
BACKGROUND OF THE INVENTION
The present invention relates to aircraft interior equipment and, more particularly, to equipment supports for seats, tables and the like.
Aircraft manufacturers often require business class passenger seats in their aircraft that can translate in the fore/aft and lateral directions for occupant comfort and convenience. The tracking mechanism that provides this function must be robust enough to withstand various use/abuse loads, in-flight gust loads, and crash loads without mechanical failure. Conventional state of the art tracking mechanisms commonly employ two sets of linear tracks consisting of parallel tubes or rails arranged in a rectangular array, two rails for lateral movements and the other two rails for fore/aft movement. The rails used in these conventional orthogonal linear track systems are typically spaced far apart for structural stability. Because of this, it is almost always necessary when locking the position of the seat after a move, that all four rails be locked. If not, the resultant unbalanced moment loads exerted by the occupant can create an undesirable “spongy” feel. This characteristic can be mitigated by employing increasingly heavier and larger elements (e.g., larger rails, larger bearings, etc.). Large and heavy, however, are always undesirable in aircraft seat design where space and weight are at a premium.
Having to lock all four rails of conventional orthogonal linear track arrangements also complicates the control mechanism because of the need to simultaneously lock four separate locations with, typically, a single-hand control. Lateral motion in an orthogonal linear track design is also limited by the width of the seat and the internal real estate required to lock the lateral rails. To increase the lateral range of motion, it is necessary to increase the width of the seat to accommodate the longer rails. Accordingly, what is needed is a support mechanism for aircraft seats and other equipment that provides orthogonal axes of motion without the large footprint and the weight problems associated with conventional orthogonal linear track designs.
SUMMARY OF THE INVENTION
The present invention solves the foregoing problem by providing a support that moves angularly rather than linearly for at least one of the axes of motion. According to an illustrative embodiment, the equipment support has a sturdy lower support link that sweeps out a lateral arc. The lower support link supports a platform that has a conventional linear track. The linear track provides for fore/aft movement substantially orthogonal to a line tangent to the center of the lateral arc. A lightweight pilot link is attached to the platform to form a parallelogram linkage that maintains the platform in a rotationally fixed attitude as the lower support link sweeps out its lateral arc. This gives the lateral movement a quasi-linear feel even if the fore/aft linear track is locked. If the fore/aft linear track is unlocked, the lateral movement can be purely linear.
BRIEF DESCRIPTION OF THE DRAWING
The present invention will be better understood from a reading of the following detailed description, taken in conjunction with the accompanying drawing figures in which like references designate like elements and, in which:
FIG. 1 is an exploded perspective view of a first embodiment of an equipment support incorporating features of the present invention;
FIG. 2 is a bottom view of the embodiment of FIG. 1 in its extreme left forward position;
FIG. 3 is a bottom view of the embodiment of FIG. 1 in its extreme right forward position;
FIG. 4 is a bottom view of the embodiment of FIG. 1 in its extreme left rear position;
FIG. 5 is a bottom view of the embodiment of FIG. 1 in its extreme right rear position;
FIG. 6 is an exploded perspective view of a second embodiment of an equipment support including a rotating sub-base member; and
FIG. 7 is a third embodiment of an equipment support including a linear track attaching the equipment support to the airframe.
DETAILED DESCRIPTION
The drawing figures are intended to illustrate to the general manner of construction and are not necessarily to scale. In the detailed description and in the drawing figures, specific illustrative examples are shown and herein described in detail. It should be understood, however, that the drawing figures and detailed description are not intended to limit the invention to the particular form disclosed, but are merely illustrative and intended to teach one of ordinary skill how to make and/or use the invention claimed herein and for setting forth the best mode for carrying out the invention.
With reference to FIGS. 1-5 , equipment support 10 comprises a base member 12 , which is adapted to be rigidly affixed to a frame 14 . Frame 14 is provided with a plurality of devises 16 which allow frame 14 to be rigidly mounted to an aircraft floor or other surface. Frame 14 may also be attached to the aircraft by means of conventional floor tracking or other means and therefore is not limited to the pin and clevis attachment of the illustrative embodiment. A support link 18 is mounted to base 12 by means of a rotating joint 20 comprising a shaft 22 supported by a thrust bearing 24 fitted to a corresponding recess in base 12 so that support link 18 is free to rotate about a vertical axis 26 defined by thrust bearing 24 .
An equipment platform 28 is mounted to support link 18 by a means of a second rotating joint 30 consisting of shaft 32 and a corresponding thrust bearing (not shown) fitted to a corresponding recess in equipment platform 28 so that equipment platform is free to rotate about a second vertical axis 36 defined by shaft 32 .
As can be determined from the foregoing, the two rotational axes about shafts 22 and 32 enable equipment platform 28 to sweep through an arc having a radius equal to the offset between the first vertical axis 26 and the second vertical axis 36 . In order to maintain equipment platform 28 in a fixed rotational attitude relative to base 12 , a pilot link 38 is attached between equipment platform 28 and base 12 by means of a third rotating joint 40 and a fourth rotating joint 42 , so that pilot link 38 rotates about a third vertical axis 44 that is parallel to and offset from first vertical axis 26 while equipment platform 28 rotates about a fourth vertical axis 46 that is offset from and parallel to second vertical axis 36 . Because the pilot link 38 need only resist rotational loads, it can be of much lighter construction than support link 18 . Accordingly, rotating joints 40 and 42 may be conventional light duty ball or even sleeve bearings.
With particular reference to FIGS. 2-4 , which depict the full range of motion of the illustrative embodiment, the length of pilot link 38 (defined as the distance between third vertical axis 44 and fourth vertical axis 46 ) is selected to be the same as the length of support link 18 (defined as the distance between first vertical axis 26 and second vertical axis 36 ). The offset between first vertical axis 26 and third vertical axis 44 is also selected to be the same as the offset between second vertical axis 36 and fourth vertical axis 46 . Accordingly when assembled, the longitudinal axis 50 of support link 18 (defined as the line of axis through first vertical axis 26 and second vertical axis 36 ) is parallel to the longitudinal axis 52 of pilot link 38 (defined as a line of action passing through third vertical axis 44 and fourth vertical axis 46 ). Similarly, the longitudinal axis 54 of base 12 (defined as a line of action passing through first vertical axis 26 and third vertical axis 44 ) is parallel to the effective longitudinal axis 56 of equipment support 28 (defined as a line of action passing through second vertical axis 36 and fourth vertical axis 46 ).
As can be determined from the foregoing, the geometry of the linkage ensures that longitudinal axes 50 and 52 are parallel at all times irrespective of the rotational position of support link 18 and pilot link 38 . Accordingly, the effective longitudinal axis of equipment support 28 , and with it support 28 itself, is always maintained in a fixed rotational attitude relative to longitudinal axis 54 of base 12 . Although in the illustrative embodiment the geometry of the linkage is selected to produce a parallelogram linkage, for other applications (e.g., conference tables in larger business aircraft) a trapezoidal or other unequal arm linkages may be incorporated to produce predetermined angular and/or translational motion of equipment platform 28 as a function of lateral movement without departing from the scope of the present invention.
As can be determined from the foregoing, support link 18 and pilot link 38 cooperate to permit equipment platform 28 to move left and right relative to base 12 through an arc that approximates the left to right movement enabled by much heavier and more complex linear seat tracks of the prior art. To provide fore and aft movement, equipment platform 28 is provided with a plurality of rollers 58 that engage corresponding tracks 60 formed in seat frame 62 . Because seat frame 62 is necessarily longer than it is wide, there is sufficient room within the confines of seat frame 62 to incorporate full fore/aft movement without track 60 or rollers 58 extending beyond the footprint of the seat frame itself. The combination, however, of the linear track comprising rollers 58 and track 60 with the support linkage comprising support link 18 and pilot link 38 considerably simplifies the release mechanism. This is because the lateral movement of equipment platform 28 may be controlled by locking support link 18 rotationally, for example by means of a pin engaging one of a plurality of holes 66 formed in metering plate 68 attached to base 12 or by other means that lock the single support link 18 rotationally, rather than locking two parallel rails simultaneously as in the prior art.
With Reference now to FIG. 6 , the ability of seat frame 62 to swivel may be provided by substitution of a sub-base 612 in place of the rigidly mounted base 12 of the embodiment of FIG. 1 . As with base 12 , sub-base 612 includes a thrust bearing 24 for supporting support link 18 as well as an attachment point for third rotating joint 40 of pivot link 38 . Additionally, however, the lower surface of sub-base 612 includes a thrust bearing (not shown) coaxial with thrust bearing 24 . The thrust bearing of sub-base 612 rides on the upper surface 614 of frame 14 thus enabling the entirety of equipment support 10 to rotate as a unit about frame 14 . A distinct advantage of this arrangement is the fore/aft and lateral adjustment axes of equipment support 10 rotate with seat frame 62 rather than remaining fixed with respect to the floor of the aircraft. This allows for much more intuitive movement of the seat frame by the user than would otherwise be possible. Once adjusted, the rotational movement of sub-base 612 may be locked by moving lock pin 615 through guide hole 616 to engage one of a plurality of holes 618 in metering plate 620 attached to frame 14 .
Although certain illustrative embodiments and methods have been disclosed herein, it will be apparent from the foregoing disclosure to those skilled in the art that variations and modifications of such embodiments and methods may be made without departing from the spirit and scope of the invention. For example, although the illustrative embodiments of FIGS. 1-6 contemplate an equipment support in which the linear track is supported by a rotating support link (track over pivot), as shown in FIG. 7 an embodiment in which the base 712 supporting the support link is itself mounted on a linear track 760 (pivot over track) is considered within the scope of the present invention. Accordingly, it is intended that the invention shall be limited only to the extent required by the appended claims and the rules and principles of applicable law. | A support for aircraft seats and other equipment has a lower support link that sweeps out a lateral arc. The lower support link supports a platform that may have a conventional linear track. The linear track provides fore/aft movement substantially orthogonal to a line tangent to the center of the lateral arc. A pilot link is attached to the platform to form a parallelogram linkage that maintains the equipment platform in a rotationally fixed attitude as the lower support link sweeps out its lateral arc. | 8 |
This application claims the benefit of U.S. Provisional Application No. 60/240,284, filed Oct. 13, 2000 and U.S. Provisional Application No. 60/284,655, filed Apr. 17, 2001.
FIELD OF THE INVENTION
The present invention relates, in general, to an improved surgical biopsy device and, more particularly, to an improved transmission assembly for use in a surgical biopsy device.
BACKGROUND OF THE INVENTION
The diagnosis and treatment of patients with cancerous tumors, pre-malignant conditions, and other disorders has long been an area of intense interest in the medical community. Non-invasive methods for examining tissue and, more particularly, breast tissue include palpation, X-ray imaging, MRI imaging, CT imaging, and ultrasound imaging. When a physician suspects that tissue may contain cancerous cells, a biopsy may be done using either an open procedure or in a percutaneous procedure. In an open procedure, a scalpel is used by the surgeon to create an incision to provide direct viewing and access to the tissue mass of interest. The biopsy may then be done by removal of the entire mass (excisional biopsy) or a part of the mass (incisional biopsy). In a percutaneous biopsy, a needle-like instrument is inserted through a very small incision to access the tissue mass of interest and to obtain a tissue sample for examination and analysis. The advantages of the percutaneous method as compared to the open method are significant: less recovery time for the patient, less pain, less surgical time, lower cost, less disruption of associated tissue and nerves and less disfigurement. Percutaneous methods are generally used in combination with imaging devices such as X-ray and ultrasound to allow the surgeon to locate the tissue mass and accurately position the biopsy instrument.
Generally there are two ways to percutaneously obtain a tissue sample from within the body, aspiration or core sampling. Aspiration of the tissue through a fine needle requires the tissue to be fragmented into small enough pieces to be withdrawn in a fluid medium. Application is less intrusive than other known sampling techniques, but one can only examine cells in the liquid (cytology) and not the cells and the structure (pathology). In core biopsy, a core or fragment of tissue is obtained for histologic examination which may be done via a frozen or paraffin section. The type of biopsy used depends mainly on various factors and no single procedure is ideal for all cases.
A number of core biopsy instruments which may be used in combination with imaging devices are known. Spring powered core biopsy devices are described and illustrated in U.S. Pat. Nos. 4,699,154, 4,944,308, and Re. 34,056. Aspiration devices are described and illustrated in U.S. Pat. Nos. 5,492,130; 5,526,821; 5,429,138 and 5,027,827.
U.S. Pat. No. 5,526,822 describes and illustrates an image-guided, vacuum-assisted, percutaneous, coring, breast biopsy instrument which takes multiple tissue samples without having to re-puncture the tissue for each sample. The physician uses this biopsy instrument to “actively” capture (using the vacuum) the tissue prior to severing it from the body. This allows the physician to sample tissues of varying hardness. The instrument described in U.S. Pat. No. 5,526,822 may also be used to collect multiple samples in numerous positions about its longitudinal axis without removing the instrument from the body. A further image-guided, vacuum-assisted, percutaneous, coring, breast biopsy instrument is described in commonly assigned U.S. application Ser. No. 08/825,899, filed on Apr. 2, 1997 and in U.S. Pat. No. 6,007,497. A handheld image-guided, vacuum-assisted, percutaneous, coring, breast biopsy instrument is described in U.S. Pat. No. 6,086,544 and in U.S. Pat. No. 6,120,462. Several image-guided, vacuum-assisted, percutaneous, coring, breast biopsy instruments are currently sold by Ethicon Endo-Surgery, Inc. under the Trademark MAMMOTOME™.
Many breast biopsies done today utilizing image-guided, vacuum-assisted, percutaneous, coring, breast biopsy instruments are still done utilizing x-ray machine. In actual clinical use the biopsy instrument (probe and driver assembly) is mounted to the three axis positioning head of the x-ray imaging machine. The three axis positioning head is located in the area between the x-ray source and the image plate. The stereotactic x-ray machines are outfitted with a computerized system which utilizes two x-ray images, of the breast taken at two different positions to calculate the x, y and z axis location of a suspect abnormality. In order to take the stereo x-ray images the x-ray source must be movable. The x-ray source is, therefore, typically mounted to an arm which, at the end opposite the x-ray source, is pivotally mounted to the frame in the region of the x-ray image plate. In a breast biopsy the breast is placed between the x-ray source and the image plate. In order to take the necessary stereo images, the clinician manually positions the x-ray source on one side and then the other of the center axis of the machine (typically 15-20 degrees to each side of the center axis), obtaining an x-ray image on each side of the breast. The computer will then, calculate the precise x, y and z location of the suspect abnormality in the breast and automatically communicate to the clinician or directly to the positioning head the targeting coordinates for the biopsy device. The clinician can then manually, or automatically, position the biopsy probe into the breast at the precise location of the abnormality.
There are generally two styles of stereotactic x-ray machines in wide spread use for breast imaging. One style is a prone stereotactic x-ray machine, because the patient lies face down on a table during the x-ray and biopsy procedures. The other style, in more wide spread use, is an upright stereotatic x-ray machine. The center axis of the upright imaging machine is vertical to the floor and the patient sits in front of the machine during the x-ray and biopsy procedures.
As described earlier in a stereotactic x-ray machine, the biopsy instrument mounts to a three axis positioning head located between the x-ray source and image plate. The distance between the x-ray source and imaging plate is known in the industry as the SID (Source to Image Distance). There is no standard SID in the industry and, in fact, the SID varies greatly from one x-ray machine manufacturer to another.
It would, therefore, be advantageous to design an image-guided, vacuum-assisted, percutaneous, coring, breast biopsy instrument which may be conveniently be mounted between the x-ray source and image plate of a stereotactic x-ray imaging machine utilizing a minimal amount of space in order to use the breast biopsy instrument with many different types of x-ray machines. It would further be advantageous to design an image-guided, vacuum-assisted, percutaneous, coring, breast biopsy instrument in which the length from the distal tip of the biopsy probe to the most proximal portion of the driver is reduced to less than approximately twenty-nine centimeters. It would further be advantageous to design a remotely driven image-guided, vacuum-assisted, percutaneous, coring, breast biopsy instrument wherein the drive cables for the instrument exit the proximal end of the biopsy instrument driver at an angle which is substantially perpendicular to the central axis of the biopsy instrument in order to minimize the length from the distal tip of the biopsy probe to the most proximal portion of the driver. It would further be advantageous to design a transmission for a remotely driven image-guided, vacuum-assisted, percutaneous, coring, breast biopsy instrument wherein the drive cables for the proximal end of the biopsy instrument driver exit the instrument driver at an angle which is substantially perpendicular to the central axis of the driver in order to minimize the length from the distal tip of the biopsy probe to the most proximal portion of the driver, the transmission converting the motion of the cables to drive the biopsy instrument cutter.
SUMMARY OF THE INVENTION
The present invention is directed to a biopsy instrument which includes a base assembly including a firing mechanism, a probe assembly detachably mounted to the base assembly and a drive assembly detachably mounted to the cutter assembly. The probe assembly includes a cutter assembly and a piercer assembly. The cutter assembly includes a cutter and a gear mechanism adapted to move the cutter. The Piercer assembly includes a piercer and a probe mount. The drive assembly includes a flexible drive shaft and a transmission. The transmission includes a first bevel gear operatively connected to a distal end of the flexible drive shaft and a second bevel gear intermeshed with the first bevel gear and operatively connected to the gear mechanism. A medical instrument according to the present invention may further include a coupling alignment sleeve operatively connected to the releasable drive mechanism.
The present invention is further directed to a transmission assembly for a medical instrument wherein the transmission assembly includes a mounting bracket, a transmission plate, a rotation coupling assembly, a translation coupling assembly, a thumbwheel rotation assembly an electrical cable strain relief, a clamping plate assembly, an encoder assembly and a flex relief. The rotation coupling assembly includes a rotation gear and a rotation drive coupling. The translation coupling assembly includes a translation gear and a translation drive coupling. The thumbwheel rotation assembly including a port drive coupling, a first port gear, a second port gear and a knob post. The clamping plate assembly including a rotational bevel gear a translational bevel gear, a rotation shaft and a translation shaft. The encoder assembly including a first bearing assembly which includes a bearing and an encoder. A transmission assembly according to the present invention my further include a gear adapter with and elongated adapter slot operatively connected to the rotation bevel gear.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to organization and methods of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in conjunction with the accompanying drawings in which:
FIG. 1 is an isometric view of a surgical biopsy system of the present invention comprising a biopsy device, control unit, and remote.
FIG. 2 is an isometric view of the biopsy probe assembly and base assembly, shown separated, with the upper base housing shown removed.
FIG. 3 is an isometric view of the biopsy probe assembly with the top shell and bottom shell shown separated to expose internal components.
FIG. 4 is an exploded isometric view of the internal components of the biopsy probe assembly of the present invention.
FIG. 5 is a longitudinal section view of the distal end of the biopsy probe assembly.
FIG. 6 is an exploded isometric view of the lower transmission assembly of the present invention.
FIG. 7 is an isometric view of the transmission showing the upper transmission assembly exploded.
FIG. 8 is an isometric view of the biopsy probe assembly and base assembly, separated, with the upper base housing not shown, as viewed from the proximal end.
FIG. 9 is an exploded isometric view of the firing mechanism of the present invention.
FIG. 10 is an exploded isometric view of an embodiment of the firing fork assembly.
FIG. 11 is an exploded isometric view of the triggering mechanism of the present invention.
FIG. 12 is an isometric view of a safety latch according to the present invention.
FIG. 13 is an isometric view of a safety button according to the present invention.
FIG. 14 is a top view of the firing mechanism of the present invention showing the mechanism in the post-fired position.
FIG. 15 is a partial, plan sectional view of the firing mechanism in the post-fired position showing the firing latch and firing rod.
FIG. 16 is a top view of the firing mechanism of the present invention showing the mechanism in the pre-fired position.
FIG. 17 is a partial, plan sectional view of the firing mechanism in the pre-fired position showing the firing latch and firing rod.
FIG. 18 is a top view of the firing mechanism of the present invention showing the arming mechanism in the relaxed position.
FIG. 19 is a partial, plan sectional view of the firing mechanism in the relaxed position showing the firing latch and firing rod.
FIG. 20 is an isometric view of the safety latch and safety button shown in the locked position.
FIG. 21 is an isometric view of the safety latch and safety button shown in the firing position.
FIG. 22 is an exploded isometric view of an alternate embodiment of the firing fork assembly.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is an isometric view showing a surgical biopsy system 10 comprising biopsy device 40 , a control unit 100 , and remote 20 . Biopsy device 40 comprises probe assembly 42 operatively and removably attached to base 44 . Base 44 may be removably attached to a moveable table 12 such as a stereotactic guidance system as may be found on mammographic x-ray machines, an example of which is Model MAMMOTEST PLUS/S available from Fischer Imaging, Inc., Denver, Colo.
Probe assembly 42 includes an elongated piercer 70 having a piercer tip 72 for penetrating soft tissue of a surgical patent. Piercer 70 comprises a piercer tube 74 and vacuum chamber tube 76 . Vacuum chamber tube 76 of piercer 70 may be fluidly connected to control unit 100 . Similarly, axial vacuum to probe assembly 42 may be obtained by fluid connection to control unit 100 . MAMMOTOME™ system tubing set Model No. MVAC1 available from Ethicon Endo-Surgery Inc., Cincinnati, Ohio is suitable for use to permit detachable fluid connection of lateral vacuum line 32 and axial vacuum line 34 to control unit 100 . Lateral vacuum line 32 and axial vacuum line 34 are made from a flexible, transparent or translucent material, such as silicone tubing, allowing for visualization of the material flowing through them. Lateral connector 33 and axial connector 35 are female and male luer connectors, respectively, commonly known and used in the medical industry. Base 44 is operatively connected to control unit 100 by control cord 26 , translation shaft 22 , and rotation shaft 24 . Translation shaft 22 and rotation shaft 24 are preferably flexible so as to permit for ease of mounting of biopsy device 40 to moveable table 12 .
Control unit 100 is used to control the sequence of actions performed by biopsy device 40 in order to obtain a biopsy sample from a surgical patient. Control unit 100 includes motors and a vacuum pump, and controls the activation of vacuum to probe assembly 42 and the translation and rotation of the cutter (not visible) in probe assembly 42 . A suitable Control unit 100 is a MAMMOTOME™ system control module Model No. SCM12 with software Model No. SCMS1 available from Ethicon Endo-Surgery Inc., Cincinnati, Ohio.
Remote 20 is operatively and removably connected to control unit 100 . Remote 20 may be used by the surgical biopsy system operator to control the sequence of actions performed by biopsy device 40 . Remote 20 may be a hand operated or foot operated device. A suitable remote 20 is MAMMOTOME™ Remote Key-pad Model No. MKEY1 available from Ethicon Endo-Surgery Inc., Cincinnati, Ohio.
FIG. 2 is an isometric view showing probe assembly 42 and base 44 separated. Upper base housing 50 is normally fixedly attached to base 44 , but has been shown removed from base 44 to provide a view of transmission 301 . Top shell tab 46 is located on the distal end of cantilever beam 41 and projects above the top surface of gear shell 18 . Top shell tab 46 inserts into tab window 48 in upper base housing 50 upon assembly of probe assembly 42 to base 44 . Once probe assembly 42 and base 44 are properly assembled, top shell tab 46 must be pushed down through tab window 48 by the user before probe assembly 42 and base 44 can be separated. A plurality of raised ribs 58 are provided on gear shell 18 to improve the user's grip on the instrument. Post 14 extends above the top surface of base shell 38 and inserts into keyhole 16 (not visible) located on the underside of gear shell 18 . Tube slot 68 in upper base housing 50 provides clearance for axial vacuum line 34 . First tang 54 and second tang 56 protrude from opposite sides of probe housing 52 and insert into first recess 64 and second recess 66 , respectively, in firing fork 62 . The proximal end of probe housing 52 fits slidably within gear shell 18 and firing fork 62 fits slidably within base shell 38 . Thus, once probe assembly 42 and base 44 are operatively assembled, probe housing 52 and firing fork 62 are able to move a fixed linear distance in a distal and proximal direction in front of gear shell 18 and base shell 38 . FIGS. 1 and 2 show probe housing 52 and firing fork 62 in their most distal position.
FIGS. 3 and 4 are views of probe assembly 42 . FIG. 3 is an isometric view of probe assembly 42 with the top shell 17 and bottom shell 19 shown separated, the top shell 17 rotated ninety degrees, to expose internal components. FIG. 4 is an exploded isometric view of the same probe assembly 42 without top shell 17 or bottom shell 19 . Gear shell 18 is formed from top shell 17 and bottom shell 19 , each injection molded from a rigid, biocompatible thermoplastic material such as polycarbonate. Upon final assembly of probe assembly 42 , top shell 17 and bottom shell 19 are joined together by ultrasonic welding along joining edge 15 , or joined by other methods well known in the art. Probe assembly 42 comprises piercer 70 having an elongated, metallic piercer tube 74 and a piercer lumen 80 (see FIGS. 4 and 5 ). On the side of the distal end of piercer tube 74 is port 78 for receiving tissue to be extracted from the surgical patient. Joined along side piercer tube 74 is an elongated, tubular, metallic vacuum chamber tube 76 having a vacuum lumen 82 (see FIGS. 4 and 5 ). Piercer lumen 80 is in fluid connection with vacuum lumen 82 via a plurality of vacuum holes 77 (See FIG. 5) located in the bottom of the “bowl” defined by port 78 . Vacuum holes 77 are small enough to remove the fluids but not large enough to allow excised tissue portions to be removed through lateral vacuum line 32 , which is fluidly connected to vacuum lumen 82 . A metallic, sharpened piercer tip 72 is fixedly attached to the distal end of piercer 70 . It is designed to penetrate soft tissue, such as the breast tissue of a female surgical patient. In the present embodiment piercer tip 72 is a three sided, pyramidal shaped point, although the tip configuration may also have other shapes.
Refer now, momentarily, to FIG. 5 . FIG. 5 is a section view of the distal end of probe assembly 42 , illustrating primarily probe housing 52 , piercer 70 , and union sleeve 90 . The proximal end of piercer 70 is fixedly attached to union sleeve 90 having a longitudinal bore 84 through it. Union sleeve 90 contains a first o-ring groove 27 and second o-ring groove 28 , spaced apart so as to allow for a traverse opening 37 between them in fluid communication with longitudinal bore 84 . First o-ring 29 and second o-ring 30 mount in first o-ring groove 27 and second o-ring groove 28 , respectively. Sleeve gear 36 is integral to union sleeve 90 and is located at its most proximal end. Lead-in cone 25 is a conical shaped metallic structure that attaches to the proximal end of union sleeve 90 . Union sleeve 90 is inserted into housing bore 57 located in the distal end of probe housing 52 , and rotatably supports the proximal end of piercer 70 . Positioning wheel 31 slides over piercer 70 and the distal end of union sleeve 90 and rotatably attaches to probe housing 52 , hence trapping lead-in cone 25 and union sleeve 90 within housing bore 57 in the distal end of probe housing 52 . Locating projection 11 on the distal end of union sleeve 90 functionally engages alignment notch 13 in positioning wheel 31 . Thus, rotating positioning wheel 31 likewise causes the rotation of piercer 70 . This allows port 78 to be readily positioned anywhere within the 360° axis of rotation of piercer 70 .
Referring again to FIGS. 3 and 4, housing extension 47 is located at the proximal end of probe housing 52 . Housing flange 53 is located at the most proximal end of housing extension 47 on probe housing 52 and is assembled just inside of top shell front slot 55 in top shell 17 . Shell insert 39 is assembled into top shell front slot 55 . First insert tab 59 and second insert tab 60 , both located on shell insert 39 , engage first shell recess 61 and second shell recess 63 , located within top shell front slot 55 , respectively. Thus, upon complete assembly of probe assembly 42 , the most proximal end of probe housing 52 containing housing flange 53 is trapped within gear shell 18 , yet slideable along housing extension 47 distal and proximal within top shell front slot 55 . Tissue sampling surface 65 is a recessed surface within probe housing 52 which provides a surface where each tissue sample will be deposited during the operation of the present invention, prior to retrieval by the clinician.
An elongated, metallic, tubular cutter 96 (see FIG. 5) is axially aligned within cutter bore 51 of probe housing 52 , longitudinal bore 84 of union sleeve 90 , and piercer lumen 80 of piercer 70 so that cutter 96 may slide easily in both the distal and proximal directions. Cutter 96 has a cutter lumen 95 through the entire length of cutter 96 . The distal end of cutter 96 is sharpened to form a cutter blade 97 for cutting tissue held against cutter blade 97 as cutter 96 is rotated. The proximal end of cutter 96 is fixedly attached to the inside of cutter gear bore 102 of cutter gear 98 . Cutter gear 98 may be metal or thermoplastic, and has a plurality of cutter gear teeth 99 , each tooth having a typical spur gear tooth configuration. Cutter seal 79 is a lip type seal and is fixedly attached to the proximal end of cutter gear 98 , and is made of a flexible material such as silicone. Tissue remover 132 fits rotatably and slidably through cutter seal 79 . Probe seal 81 is also a lip type seal made of a flexible material such as silicone rubber and is fixedly inserted into the proximal end of cutter bore 51 at the proximal end of probe housing 52 . Cutter 96 fits rotatably and slidably through cutter seal 79 . Cutter seal 79 and probe seal 81 operate to prevent fluids from entering the space within gear shell 18 during a surgical biopsy procedure.
Still in FIGS. 3 and 4, cutter gear 98 is driven by elongated drive gear 104 having a plurality of drive gear teeth 106 designed to mesh with cutter gear teeth 99 . The function of elongated drive gear 104 is to rotate cutter gear 98 and cutter 96 as they translate in both longitudinal directions. Elongated drive gear 104 is preferably made of a thermoplastic material, such as liquid crystal polymer. Distal drive axle 108 projects from the distal end of elongated drive gear 104 and mounts rotatably into an axle support rib (not visible) molded on the inside of top shell 17 and held in place by first gear support rib located on bottom shell 19 . Gear shaft 110 projects from the proximal end of drive gear 104 and is rotatably supported by a gear shaft slot 69 located in the proximal end of top shell 17 and by second gear support rib 137 located on bottom shell 19 . Drive gear slot 101 is located on the most proximal end of gear shaft 110 as a means for rotationally engaging drive gear 104 .
Still referring to FIGS. 3 and 4, cutter carriage 124 is provided to hold cutter gear 98 and to carry cutter gear 98 as it is rotated and translated in the distal and proximal directions. Cutter carriage 124 is preferably molded from a thermoplastic material and is generally cylindrically shaped with a threaded bore 126 through it and with carriage foot 130 extending from its side. Carriage foot 130 has a foot recess 128 formed into it and foot slot 127 for rotatably holding cutter gear 98 in the proper orientation for cutter gear teeth 99 to mesh properly with drive gear teeth 106 . Lower carriage guide 103 projects down from cutter carriage 124 and slidably engages lower guide slot 107 molded on the inside surface of bottom shell 19 . Upper carriage guide 105 projects up from carriage foot 130 and slidably engages a upper guide slot 109 molded on the inside of top shell 17 . Cutter carriage 124 is attached via threaded bore 126 to elongated screw 114 , which is parallel to drive gear 104 . Screw 114 has a plurality of conventional lead screw threads 116 and is preferably made of a thermoplastic material. The rotation of elongated screw 114 in one direction causes cutter carriage 124 to move distally, while the reverse rotation of elongated screw 114 causes cutter carriage 124 to move proximally. As a result, cutter gear 98 moves distally and proximally according to the direction of the screw rotation, which in turn advances cutter 96 distally or retracts it proximally. In the present embodiment, elongated screw 114 is shown with a right hand thread so that clockwise rotation (looking from the proximal to distal direction) causes cutter carriage 124 to translate in the proximal direction. Distal screw axle 118 projects from the distal end of elongated screw 114 and mounts rotatably into an axle support rib (not visible) molded on the inside of top shell 17 and held in place by first screw support rib 111 located on bottom shell 19 . Screw shaft 120 projects from the proximal end of elongated screw 114 and is rotatably supported by a screw shaft slot 71 located in the proximal end of top shell 17 and by second screw support rib 112 located on bottom shell 19 . Lead screw slot 122 is located on the most proximal end of screw shaft 120 as a means for rotationally engaging elongated screw 114 .
At this point in the detailed description it should be pointed out that during the operation of the biopsy instrument cutter 96 translates in either direction between a fully retracted position, just proximal to tissue sampling surface 65 as referenced by cutter blade 97 , and a fully deployed position wherein cutter blade 97 is located just distal to port 78 . As cutter 96 translates between these end points there are a number of intermediate positions wherein adjustments may be made to the cutter rotational and translational speed as commanded by control unit 100 . These intermediate positions and the adjustments made to the cutter depend on the programming of control unit 100 .
Referring now to FIG. 5, the distal end of lateral vacuum line 32 is attached to lateral fitting 92 located on the distal end of probe housing 52 . Lateral fitting 92 has lateral hole 117 through it along its axis in fluid communication with housing bore 57 . Lateral hole 117 in lateral fitting 92 is positioned within housing bore 57 such that when union sleeve 90 is inserted into housing bore 57 lateral hole 117 is located in the space created between first and second o-rings, 29 and 30 respectively. Locating lateral hole 117 in the space between first and second o-rings 29 and 30 , respectively, allows for the communication of fluids between vacuum lumen 82 and control unit 100 .
Referring again to FIGS. 3 and 4, axial vacuum line 34 is fluidly attached to tissue remover support 129 which is in turn fluidly attached to the proximal end of an elongated, metallic, tubular tissue remover 132 . Axial vacuum line 34 allows for the communication of fluids between piercer lumen 80 , cutter lumen 95 , and control unit 100 . Tissue remover support 129 fits into axial support slot 73 located in the proximal end of top shell 17 . Strainer 134 is located on the distal end of tissue remover 132 and functions to prevent passage of fragmented tissue portions through it and into control unit 100 . Tissue remover 132 inserts slidably into cutter lumen 95 of cutter 96 . During the operation of the biopsy instrument, tissue remover 132 is always stationary, being fixedly attached at its proximal end to tissue remover support 129 which is fixed within axial support slot 73 located in the proximal end of top shell 17 . When cutter 96 is fully retracted to its most proximal position, the distal end of tissue remover 132 is approximately even with the distal end of cutter 96 (see FIG. 5 ). The distal end of cutter 96 , when at its most proximal position, and probe housing 52 at its most distal position, is slightly distal to housing wall 67 which is proximal and perpendicular to tissue sampling surface 65 .
Probe rotation rod 85 is an elongated, solid metal rod. Rotation rod gear 86 is a spur gear fixedly attached to the distal end of probe rotation rod 85 . Rotation rod flat 87 is located at the proximal end of probe rotation rod 85 . Rotation rod flat 87 is approximately one-third to one-half the rod diameter in depth and extending from its proximal end approximately one inch in length. Rotation rod flat 87 thus creates a “D” shaped geometry at the proximal end of probe rotation rod 85 . Rod bushing 88 is made of molded thermoplastic and is cylindrical in shape. At its distal end is bushing bore 89 which is a “D” shaped hole approximately one inch in depth, designed to slidably receive the proximal end of probe rotation rod 85 . Rod bushing 88 fits rotatably into axial support slot 73 below tissue remover support 129 at the proximal end of top shell 17 . The longitudinal position of rod bushing 88 is fixed by the raised sections on both sides of bushing groove 93 , upon assembly into the proximal end of top shell 17 . Rod bushing drive slot 91 is located on the most proximal end of rod bushing 88 as a means for rotationally engaging rod bushing 88 . Rotation gear 86 is rotatably fixed into gear cavity 115 on the underside of probe housing 52 , the opening being in communication with housing bore 57 (see FIG. 5 ). Rotation rod gear 86 operably engages sleeve gear 36 located at the proximal end of union sleeve 90 . The distal end of probe rotation rod 85 with rotation rod gear 86 attached is rotatably fixed to the underside of probe housing 52 by rotation gear cover 94 . Rotation gear cover 94 is molded from a thermoplastic material and is fixedly attached to probe housing 52 by four raised cylindrical pins which press fit into four holes (not visible) in probe housing 52 . Probe rotation rod 85 inserts rotatably and slidably through rod hole 43 in shell insert 39 . The proximal end of probe rotation rod 85 slidably engages bushing bore 89 in rod bushing 88 . Thus, rotation of rod bushing 88 causes rotation of probe rotation rod 85 which is fixedly attached to rotation rod gear 86 causing rotation of union sleeve 90 which is fixedly attached to piercer 70 , which contains port 78 .
It is important for the user of the surgical biopsy system of the present invention to be able to “fire” the piercer 70 into the tissue of a surgical patient. It is also important that the user be able to rotate piercer 70 about its axis so as to properly position port 78 , regardless of linear position of piercer 70 pre-fired vs. post-fired (positions discussed later). The slidable interface between probe rotation rod 85 and rod bushing 88 plays an important role in providing this capability. Probe rotation rod 85 follows the linear movement of piercer 70 , while the linear movement of rod bushing 88 is restricted by the fact that it is rotatably attached to top shell 17 . Thus the “D” shaped geometry on the proximal end of rotation rod 85 and the “D” shaped hole in the distal end of rod bushing 88 , designed to slidably receive the proximal end of rotation rod 85 , permit the user to turn port rotation knob 45 , which is operably connected to rod bushing 88 through a chain of elements described later, and effect the rotation of piercer 70 , irrelevant of the linear position of piercer 70 .
Bottom shell 19 fixedly attaches to top shell 17 as described earlier. Its function is to hold in place and contain the elements previously described, which have been assembled into top shell 17 . Keyhole 16 is centered at the distal end of bottom shell 19 . It slidably and removably engages post 14 (See FIG. 2 ), permitting probe assembly 42 to be operatively and removably connected to base 44 . First screw support rib 111 and second screw support rib 112 are each integrally molded to bottom shell 19 and support the distal and proximal ends, respectively, of elongated screw 114 . First gear support rib 136 and second gear support rib 137 likewise are each integrally molded to bottom shell 19 and support the distal and proximal ends, respectively, of elongated drive gear 104 . Rod bushing support rib 139 integrally molded to bottom shell 19 supports the distal end of rod bushing 88 .
FIG. 6 is an exploded isometric view of lower transmission assembly 302 . Translation shaft 22 and rotation shaft 24 is each a flexible coaxial cable comprising a flexible rotatable center core surrounded by a flexible tubular casing,. At their most proximal ends is provided a coupling means for removably and operatively connecting translation shaft 22 and rotation shaft 24 to control unit 100 . The distal ends of translation shaft 22 and rotation shaft 24 each insert through first boot bore 309 and second boot bore 311 , respectively. Flex boot 303 is molded from a thermoplastic elastomer such as, for example, polyurethane, and functions as a “flex relief” for translation shaft 22 , rotation shaft 24 , and control cord 26 . Rotation shaft ferrule 305 is a metallic tubular structure comprising a through bore with a counter bore at its proximal end for fixedly attaching, via crimping or swaging as is well known in the art, to the outer tubular casing of rotation shaft 24 . At the distal end of rotation shaft ferrule 305 is a flared, counter bored section for receiving first bearing assembly 315 . A suitable example of first bearing assembly 315 is Model No. S9912Y-E1531PSO, available from Stock Drive Products, New Hyde Park, N.Y. Rotation shaft adapter 319 is made of stainless steel and has a proximal end with a counter bore. Its proximal end inserts through the bore of first bearing assembly 315 and the counter bore slips over the distal end of the rotatable center core of rotation shaft 24 and is fixedly attached by crimping or swaging. The distal end of rotation shaft adapter 319 is inserted through the bore in first bevel gear 321 and is fixedly attached by a slotted spring pin. Similarly, translation shaft ferrule 307 is a metallic tubular structure comprising a through bore with a counter bore at its proximal end for fixedly attaching, via crimping or swaging, to the outer tubular casing of translation shaft 22 . At the distal end of translation shaft ferrule 307 is a flared, counter bored section for receiving thrust washer 317 . Translation shaft adapter 323 is made of stainless steel and has a proximal end with a counter bore. Its proximal end inserts through the bore of thrust washer 317 and the counter bore slips over the distal end of the rotatable center core of translation shaft 22 and is fixedly attached by crimping or swaging. The distal end of translation shaft adapter 323 is slotted as a means to engage the proximal end of encoder shaft 312 , which extends through encoder 310 . Encoder 310 communicates information to control unit 100 about the translation position and translation speed of cutter 96 . Encoder 310 includes an electrical cord containing a plurality of electrical conductors, which has an electrical connector affixed at its most distal end for removable electrical connection to printed circuit board 262 (See FIG. 9 ). A suitable miniature encoder 310 is commercially available as Model sed10-300-eth2 from CUI Stack, Inc. Encoder shaft 312 has two opposing flats on its proximal end, which engage translation shaft adapter 323 , and a cylindrical distal end which is inserted into a counter bore in the proximal end of gear adapter 316 and is fixedly attached by a slotted spring pin. The distal end of gear adapter 316 is inserted through the bore of second bearing assembly 318 , through the bore of shaft spacer 322 , and finally through the bore in second bevel gear 325 which is attached to gear adapter 316 by a slotted spring pin. Adapter slot 320 in gear adapter 316 is a through slot that is slightly longer along the center axis of gear adapter 316 than it is wide. When second bevel gear 325 is pinned to gear adapter 316 , adapter slot 320 allows for a slight amount of distal to proximal movement of second bevel gear 325 relative to gear adapter 316 . This movement is helpful in compensating for “run-out” in the gear teeth of second bevel gear 325 and is important for eliminating vibration and noise as a result of this run-out as the teeth of second bevel gear 325 mesh with third bevel gear 350 .
Encoder housing assembly 329 comprises left encoder housing half 326 and right encoder housing half 328 , which are molded thermoplastic shells. When assembled, left encoder housing half 326 and right encoder housing half 328 encase encoder 310 and capture the distal end of translation shaft 22 and rotation shaft 24 . Left encoder housing half is attached to transmission plate 330 (see FIG. 7) using a cap screw. Encoder 310 is placed in first shell cavity 332 , preventing rotational or lateral movement of the outer housing of encoder 310 . The distal end of rotation shaft ferrule 305 rests in second shell cavity 334 , which prevents lateral movement of rotation shaft 24 . The distal end of translation shaft ferrule 307 rests in third shell cavity 336 , which again prevents lateral movement of translation shaft 22 . Second bearing assembly 318 rests in fourth shell cavity 338 . Right encoder housing half 328 , containing essentially a mirror image of the cavities found inside left encoder housing half 326 , assembles to left encoder housing half 326 and transmission plate 330 via two cap screws.
Still referring to FIG. 6, control cord 26 is flexible and contains a plurality of electrical conductors for communication information between biopsy device 40 and control unit 100 (see FIG. 1 ). At the proximal end of control cord 26 is provided a means of removable electrical connection to control unit 100 . The distal end of control cord 26 inserts through third boot bore 313 located in flex boot 303 . Control cord strain relief 369 is a flexible thermoplastic material and is over molded to the distal end of control cord 26 and is fixedly attached to transmission plate 330 in a recessed area at strain relief bore 371 (see FIG. 7 ), to restrict linear and rotational movement of the distal end of the cord. The most distal end of control cord 26 contains a connector for removably and electrically affixing control cord 26 to printed circuit board 262 (see FIG. 9 ).
FIG. 7 is an isometric view of transmission 301 . Upper transmission assembly 304 is shown exploded. Translation coupling assembly 337 consists of translation coupling alignment sleeve 373 , translation drive coupling 340 , third bearing assembly 344 , first coupling spacer 348 , and third bevel gear 350 . Third bearing assembly 344 is press fit into first counter bore 345 in transmission plate 330 . Translation drive coupling 340 has a flat bladed distal end which will operatively couple with lead screw slot 122 (see FIG. 8) located at the proximal end of elongated screw 114 . Translation coupling alignment sleeve 373 is a tubular structure which is fixedly attached to the distal end of translation drive coupling 340 via first sleeve pin 375 so that the most distal end of translation coupling alignment sleeve 373 is flush with the most distal end of translation drive coupling 340 . The cylindrical proximal end of translation drive coupling 340 inserts through first counter bore 345 , through the bore of third bearing assembly 344 , through the bore of first coupling spacer 348 , and finally through the bore in third bevel gear 350 which is fixedly attached to translation drive coupling 340 by a slotted spring pin. The gear teeth of third bevel gear 350 mesh with the gear teeth of second bevel gear 325 . Thus, rotation of the center core of translation shaft 22 results in the rotation of translation drive coupling 340 . When translation drive coupling 340 is operatively coupled to elongated screw 114 via lead screw slot 122 in screw shaft 120 , rotation of translation shaft 22 causes rotation of elongated screw 114 which results, as discussed earlier, in the distal or proximal translation of cutter 96 , depending on the direction of translation shaft 22 rotation. The inside diameter of translation coupling alignment sleeve 373 is only slightly larger than the outside diameter of screw shaft 120 . Translation coupling alignment sleeve 373 functions to assure axial alignment of screw shaft 120 and translation drive coupling 340 to minimize vibration and noise.
In a similar manner, rotation coupling assembly 339 consists of rotation coupling alignment sleeve 374 , rotation drive coupling 342 , fourth bearing assembly 346 , second coupling spacer 349 , and fourth bevel gear 351 . Fourth bearing assembly 346 is press fit into second counter bore 347 in transmission plate 330 . A suitable example of fourth bearing assembly 346 , as well as second and third bearing assemblies 318 and 344 , respectively, is available as Model No. S9912Y-E1837PSO, available from Stock Drive Products, New Hyde Park, N.Y. Rotation drive coupling 342 has a flat bladed distal end which will operatively couple with drive gear slot 101 (see FIG. 8) located at the proximal end of elongated drive gear 104 . Rotation coupling alignment sleeve 374 is a tubular structure which is fixedly attached to the distal end of rotation drive coupling 342 via second sleeve pin 376 so that the most distal end of rotation coupling alignment sleeve 374 is flush with the most distal end of rotation drive coupling 342 . The cylindrical proximal end of rotation drive coupling 342 inserts through second counter bore 347 , through the bore of fourth bearing assembly 346 , through the bore of second coupling spacer 349 , and finally through the bore in fourth bevel gear 351 , which is fixedly attached to rotation drive coupling 342 by a slotted spring pin. The gear teeth of fourth bevel gear 351 mesh with the gear teeth of first bevel gear 321 . Thus, rotation of the center core of rotation shaft 24 results in the rotation of rotation drive coupling 342 . When rotation drive coupling 342 is operatively coupled to elongated drive gear 104 via drive gear slot 101 located in gear shaft 110 , rotation of rotation shaft 24 causes rotation of elongated drive gear 104 , which results in the rotation of cutter 96 . The inside diameter of rotation coupling alignment sleeve 374 is only slightly larger than the outside diameter of gear shaft 110 . Rotation coupling alignment sleeve 374 functions to assure axial alignment of gear shaft 110 and rotation drive coupling 342 to minimize vibration and noise.
A suitable example of first, second, third, and fourth bevel gears 321 , 325 , 350 , and 351 , respectively, is Model No. A1M-4-Y32016-M available from Stock Drive Products, New Hyde Park, N.Y.
Continuing in FIG. 7, port drive coupling 353 has a flat bladed distal end which will operatively couple with rod bushing drive slot 91 (see FIG. 8) located at the proximal end of rod bushing 88 . The cylindrical proximal end of port drive coupling 353 inserts through the bore in first port gear 355 , which is fixedly attached by a slotted spring pin, then inserted through first port coupling bore 359 . First coupling washer 362 slips over the proximal end of drive port coupling 353 and first coupling o-ring 364 snaps into a groove at the most proximal end of drive port coupling 353 , which now rotatably secures the assembly to transmission plate 330 . Knob post 367 is made of stainless steel, is generally cylindrical, and has a flange on its most distal end and a flat approximately one-third to one-half its diameter in depth and extending from its proximal end one half inch in length. Knob post 367 inserts through the bore of second port gear 357 , which is fixedly attached by a slotted spring pin to the distal end of knob post 367 . Suitable examples of first and second port gears 355 and 357 , respectively, are available as Model No. A1N1-N32012, available from Stock Drive Products, New Hyde Park, N.Y. The proximal end of knob post 367 is inserted through second port coupling bore 360 until second port gear 357 aligns and meshes with first port gear 355 . Second coupling washer 363 slips over the proximal end of knob post 367 and second coupling o-ring 365 snaps into a groove located adjacent to the distal end of knob post 367 , thus rotatably securing the assembly to transmission plate 330 . Port rotation knob 45 fixedly attaches to the proximal end of knob post 367 . A suitable port rotation knob 45 is Model No. PT-3-P-S available from Rogan Corp., Northbrook, Ill. Thus, when port drive coupling 353 is operatively coupled to rod bushing 88 via rod bushing drive slot 91 , user rotation of port rotation knob 45 causes rotation of rod bushing 88 which results in the rotation of piercer 70 . This allows port 78 to be readily positioned anywhere within the 360° axis of rotation of piercer 70 . Transmission plate 330 attaches to the proximal end of upper base shell 161 via two screws.
There is an important benefit derived from the design of transmission 301 as described. The fact that the translation shaft 22 , rotation shaft 24 , and control cord 26 enter the biopsy device 40 at a right angle to the device's center axis permits for a short overall length for the biopsy device. This allows the device to fit into a smaller area than would accommodate a device with the shafts protruding directly out the back (proximal end) parallel to the center axis.
FIG. 8 is an isometric view of probe assembly 42 and base 44 , as viewed from their proximal ends. Upper base housing 50 is not shown so as to permit a clear view of transmission 301 fully assembled. Also clearly visible are lead screw slot 122 , drive gear slot 101 , and rod bushing drive slot 91 , which operably connect to transmission 301 as previously described.
FIG. 9 is an exploded isometric view of firing mechanism 160 . Upper base shell 161 is shown exploded and lower base shell 204 is shown exploded and rotated 90 degrees clockwise. Also exploded and rotated 90 degrees clockwise for clarity is printed circuit board 262 and frame screw 163 .
Firing mechanism 160 , shown in FIG. 9, operates to fire the distal end of probe assembly 42 into tissue. Base shell 38 (see FIG. 2) supports and houses firing mechanism 160 , and is assembled from upper base shell 161 and lower base shell 204 . Base hooks 165 on lower base shell 204 insert into base slots 162 in upper base shell 161 to enable assembly of the components to create base shell 38 . Frame screw 163 inserts through a clearance hole in frame bottom 204 and fastens into firing latch block 242 to tie upper base shell 161 and lower base shell 204 together.
Firing fork 62 extends from firing mechanism 160 through to the exterior of base shell 38 to accept probe housing 52 of probe assembly 42 (see FIG. 2 ). FIG. 9 shows firing fork 62 in its most distal allowable position and shows other components of firing mechanism 160 in appropriate positions for firing fork 62 to be at its most distal allowable position.
Upon mating of the probe assembly 42 with the base 44 , first tang 54 and second tang 56 insert into first recess 64 and second recess 66 , respectively, in firing fork 62 at the distal end of firing fork assembly 164 . Features on firing fork 62 also include probe slot 167 , which is approximately “U” shaped to accept probe assembly 42 , and clearance slot 169 , allowing clearance for probe rotation rod 85 .
Firing fork assembly 164 , shown exploded in FIG. 10, is a unique assembly detachable from the rest of firing mechanism 160 without the use of tools. Firing fork 62 slides over the outer diameter of firing spade 178 while firing fork keys 181 insert into firing spade slots 180 . Firing spade slots 180 prevent rotation of firing fork 62 relative to firing spade 178 . Firing spade 178 possesses a threaded internal diameter at its distal end and a proximal spade end 196 at its proximal end. Proximal spade end 196 can comprise a flattened section, resembling, for example, the working end of a flathead screwdriver. The threaded diameter at the distal end of firing spade 178 receives screw 182 to hold firing fork 62 to firing spade 178 . The head 184 of screw 182 abuts the distal end of firing spade 178 upon tightening. Abutting the head 184 of screw 182 against the distal end of firing spade 178 prevents tightening of the screw against the firing fork 62 . The head 184 of screw 182 and the proximal end 186 of firing spade slot 180 provide proximal and distal stops for firing fork 62 while allowing slight axial play.
Firing spacer 188 attaches at the proximal end of firing spade 178 with the aid of dowel pins 190 . Firing spacer 188 slips onto and is rotatable relative to firing spade 178 . It should be noted that minimizing the clearance between the inside diameter of firing spacer 188 and the outside diameter of firing spade 178 improves the stability of firing fork assembly 164 , an important attribute.
Near the proximal end of firing spacer 188 , easily visible depth marker line 189 is inscribed. Dowel pins 190 press into receiving holes 192 on firing spacer 188 and ride within firing spade groove 194 to allow rotation of firing spacer 188 relative to firing spade 178 while preventing axial movement of firing spacer 188 relative to firing spade 178 . A threaded internal diameter at the proximal end of firing spacer 188 facilitates assembly and removal of the firing fork assembly 164 for cleaning.
FIG. 9 shows that firing fork assembly 164 threads onto end fitting 166 , pinned at the distal end of firing fork shaft 168 . End fitting 166 can be made of a soft stainless steel for easy machining of slot and threads while firing fork shaft 168 can be made of a hardenable stainless to accommodate induced stress. Proximal spade end 196 fits into spade slot 198 of end fitting 166 to prevent rotation of firing fork assembly 164 relative to firing fork shaft 168 . The threaded internal diameter of the proximal end of firing spacer 188 screws onto the threaded outer diameter of end fitting 166 to removably attach firing fork assembly 164 . Small firing bushings 170 , fashioned from a plastic such as acetal, support firing fork shaft 168 and allow it to move proximally and distally. Proximal saddle support 172 and distal saddle support 173 , machined into upper base shell 161 , support small firing bushings 170 while long clamp plate 174 and short clamp plate 175 capture and retain small firing bushings 170 into proximal and distal saddle supports 172 and 173 , respectively. Long clamp plate 174 and short clamp plate 175 can attach to proximal saddle support 172 and distal saddle support 173 using fasteners, such as, for example, clamp plate mounting screws 176 . Flanges at each end of the small firing bushings 170 bear against the proximal and distal sides of saddle supports 172 and clamp plates 174 to restrain small firing bushings 170 from moving proximally and distally with the movement of firing fork shaft 168 . Additional support is gained by the large firing bushing 200 surrounding firing spacer 188 . Large firing bushing 200 , split for easy assembly, resides in firing bushing housing 202 machined into upper base shell 161 and lower base shell 204 .
Firing fork shaft 168 carries other parts that facilitate the operation of firing mechanism 160 . Spring collar roll pin 212 fixedly attaches spring collar 214 to firing fork shaft 168 . Shock pad 216 adheres to the distal side of spring collar 214 and contacts distal interior wall 218 of base shell 38 when firing fork shaft 168 is in its distal position. Shock pad 216 can be made from many shock-absorbing materials, such as, for example, rubber. Main spring 217 surrounds firing fork shaft 168 and bears against the distal side of distal saddle support 173 and the proximal side of spring collar 214 to force firing fork shaft 168 distally. Magnet holder roll pin 208 fixedly attaches magnet holder 206 to firing fork shaft 168 . Magnet 210 is crimped into magnet holder 206 . Nearer the proximal end of firing fork shaft 168 , firing main link pin 224 passes through firing fork shaft slot 225 to hold firing fork shaft 168 to carriage 220 . Firing main link pin 224 also captures curved firing levers 222 retaining them to the carriage 220 . Firing main link pin 224 is flanged on one end. The other end of firing main link pin 224 extends through carriage 220 to retain carriage 220 , firing fork shaft 168 , and curved firing levers 222 , where it is retained by welding to the lower curved firing lever.
Curved firing levers 222 and firing linkages 226 drive the arming of firing mechanism 160 . Curved firing levers 222 pin to firing linkages 226 using firing link pins 228 which are welded to firing levers 222 . Firing linkages 226 in turn pin to upper base shell 161 using frame link dowel pins 230 pressed into upper base shell 161 . Long clamp plate 174 retains firing linkages 226 using clamp plate mounting screws 176 . Each pinned joint of curved firing levers 222 , firing linkages 226 , and carriage 220 is rotatably movable about the axis of the pin.
Each curved firing lever 222 has a portion that extends laterally outwards through a slot located on either side of base shell 38 (See FIG. 2 ). A curved firing lever end 232 is attached to each curved firing lever 222 on the extension of curved firing lever 222 external to base shell 38 . Curved firing lever end 232 provides a convenient user interface for arming the firing mechanism. Arming the mechanism will be described later. The coil of torsion spring 234 surrounds each pinned joint of curved firing levers 222 and firing linkages 226 . The legs of link torsion springs 234 extend outwardly to hook into curved firing levers 222 and firing linkages 226 , applying a torque rotating them relative to each other.
Locating firing linkages 226 and curved firing levers 222 at different distances from upper base shell 161 allows them clearance to pass by each other upon operation. Curved firing levers 222 have bends to offset them in a direction perpendicular to upper base shell 161 . The offset bends let them move within planes at different distances from upper base shell 161 while having the curved firing lever ends emerge from the slot created for that purpose in upper base shell 161 . Spacer 223 separates the links on the pin 230 . Having a curved firing lever 222 and firing linkage 226 on each side of the longitudinal centerline allows access by the user to operate firing mechanism 160 from either side of base shell 38 .
Fasteners secure a printed circuit board 262 to lower base shell 204 and latch block 242 . Printed circuit board 262 contains Hall-effect switch 264 for sensing the proximity of magnet 210 . A suitable Hall-effect switch 264 is Model No. A3142ELT available from Allegro Microsystems, Inc., Worcester, Mass. When firing fork 168 and associated magnet 210 are in the most proximal position (pre-fired position, as described later), magnet 210 is held in a position near Hall-effect switch 264 .
FIG. 11 is an exploded isometric view of triggering mechanism 235 , seen in FIG. 9 . Triggering mechanism 235 safely latches and fires firing fork shaft 168 . Triggering mechanism 235 comprises firing latch 236 , firing latch block 242 , firing button shaft 244 and roller 241 , firing latch spring 246 , firing button shaft spring 247 , safety block 248 , safety latch 250 , safety latch torsion spring 251 , safety latch cover 252 , and firing button 254 .
Firing latch block 242 encloses the proximal portion of firing latch 236 and serves as a mounting platform for components of triggering mechanism 235 . Firing latch pin 237 and firing block pin 239 rigidly retain firing latch block 242 to upper base shell 161 . Firing latch pin 237 rotatably pins firing latch 236 to upper base shell 161 while passing through firing latch block 242 . Firing latch 236 pivots within a slot in upper base shell 161 . Firing latch spring 246 is compressed between firing latch block 242 and firing latch 236 , thereby forcing the distal end of firing latch 236 towards firing fork shaft 168 . Firing latch 236 possesses a firing latch hook 238 at its distal end, which removably latches into a firing fork shaft retainer 240 located at the proximal end of firing fork shaft 168 . Firing button shaft 244 slidably moves proximally and distally within a bore in firing latch block 242 and has roller 241 rotatably pinned to its distal portion to engage firing latch 236 to cause rotation of firing latch 236 . Firing button shaft spring 247 forces firing button shaft 244 proximally. Firing button shaft 244 is retained by safety block 248 , which is mounted to the proximal side of firing latch block 242 . Safety latch 250 resides within a counter bore on the proximal side of safety block 248 and is retained by safety latch cover 252 . Fasteners such as screws hold safety latch cover 252 in place.
Safety latch 250 is designed to facilitate locking and unlocking of the firing mechanism. Safety latch 250 can be rotated within the counter bore on safety block 248 through a rotation angle, while safety latch torsion spring 251 has extending legs hooked into safety block 248 and safety latch 250 to apply torque to safety latch 250 . Safety block 248 defines a locked position safety latch stop 245 and an unlocked position safety latch stop 243 separated by the rotation angle. Safety latch handle 249 extends radially from safety latch 250 to facilitate grasping and rotating of safety latch 250 by the user. Safety latch handle 249 also forms surfaces to abut safety latch stops 245 and 243 to limit the rotation angle. In the locked position, safety latch torsion spring 251 forces safety latch handle 249 against the locked position safety latch stop 245 , while in the unlocked position, the user forces safety latch handle 249 against unlocked position safety latch stop 243 . In the illustrated embodiment of the invention, the rotation angle through which safety latch 250 can be rotated is about thirty-five degrees. FIG. 12 shows that safety latch 250 contains two firing button stops 256 with one firing button stop 256 on each side of the longitudinal axis of firing button 254 at assembly. The firing button stops 256 interact with firing button 254 to effect locking (preventing lateral movement) and unlocking (allowing lateral movement) of firing button 254 .
FIG. 13 shows an isometric view of firing button 254 . Firing button 254 fixedly attaches to firing button shaft 244 (see FIG. 11 ), extends proximally through the center of safety latch 250 (see FIG. 12 ), and presents a proximal, flattened, cylindrical thumb pad 257 located at its most proximal end to the user. Firing button 254 comprises a smaller firing button outer diameter 258 having narrow flats 259 and wide flats 261 angularly offset from each other by the rotation angle traveled by safety latch 250 . Larger firing button outer diameter 260 is free of flats. A distal contact surface 255 exists proximally of narrow flats 259 and is substantially perpendicular to the longitudinal axis of firing button 254 . Firing button stops 256 , located on safety latch 250 , are separated by a distance slightly larger than the distance between wide flats 261 and less than the smaller firing button outer diameter 258 . Firing button stops 256 can flex in the radial direction, but resist flexing in the axial direction. The difference in stiffness in different directions can be accomplished by, for example, different thicknesses of the firing button stops 256 in the axial direction and in the radial direction.
When safety latch 250 is in the locked position, pushing firing button 254 will force distal contact surface 255 against firing button stops 256 . Firing button stops 256 prevent further proximal axial movement of firing button 254 because of rigidity in the axial direction.
Following is a functional description of the operation of the firing mechanism of the present invention:
A user arms and fires the firing mechanism during use of the probe assembly 42 in a surgical procedure. The user begins in the fired position depicted in FIGS. 14 and 15, grasps one of the curved firing lever ends 232 , and moves outboard end of curved firing lever 222 proximally. This begins action wherein each grasped curved firing lever 222 , each firing linkage 226 , carriage 220 , and upper base shell 161 act as four-bar linkage systems with upper base shell 161 being the stationary link and carriage 220 being a translational link. Motion can be described of all three movable links relative to the upper base shell 161 . Either curved firing lever end 232 can be moved by the user. Duplicity exists in the illustrated embodiment of the invention to facilitate user access from either side of base 44 .
Rotating either curved firing lever 222 in a direction that moves the curved firing lever end 232 proximally effects motion of the two members pinned to curved firing member 222 . Curved firing member 222 transfers motion through one pinned joint to carriage 220 to move it proximally along firing fork shaft 168 . Curved firing member 222 also transfers motion through a second pinned joint to firing linkage 226 , rotating the pinned joint towards firing fork shaft 168 . Firing linkage 226 is pinned to stationary upper base shell 161 and rotates about the pinned joint located on upper base shell 161 .
Carriage 220 , driven by curved firing member 222 , translates proximally along firing fork shaft 168 carrying main link pin 224 within firing fork shaft slot 225 until firing main link pin 224 reaches the proximal end of firing fork shaft slot 225 . Further proximal motion of carriage 220 and firing main link pin 224 begins to drive proximal motion of firing fork shaft 168 . Firing fork shaft 168 translates proximally through small firing bushings 170 .
As firing fork shaft 168 translates proximally, it carries with it attached firing fork assembly 164 . Firing fork shaft 168 also carries proximally attached spring collar 214 , decreasing the distance between spring collar 214 and distal saddle support 173 . Main spring 217 , located between spring collar 214 and distal saddle support 173 , becomes more compressed exerting more force against spring collar 214 . Firing fork shaft 168 continues to move proximally and continues to compress main spring 217 until the proximal end of firing fork shaft 168 reaches firing latch 236 (see FIG. 15 ). The proximal end of firing fork shaft 168 contacts firing latch 236 and exerts a force rotating it out of the path of proximally advancing firing fork shaft 168 . The proximal end of firing fork shaft 168 and the distal end of firing latch 236 have contoured surfaces to act as cams to assist in lifting firing latch 236 . Rotating firing latch 236 compresses firing latch spring 246 , exerting a force to hold firing latch 236 onto the proximal end of firing fork shaft 168 . Once the firing fork shaft retainer 240 has proceeded proximally to a position under firing latch hook 238 , firing latch spring 246 urges firing latch hook 238 into firing fork shaft retainer 240 by rotating firing latch 236 towards firing fork 168 . Firing assembly 160 is now in the pre-fire position shown in FIGS. 16 and 17.
The user can now release curved firing lever end 232 . Once the user releases curved firing lever end 232 , main spring 217 applies force urging firing fork 168 distally along its axis. The distal force moves firing fork shaft retainer 240 towards firing latch hook 238 extending down into firing fork shaft retainer 240 (see FIG. 19 ). The proximal wall of firing fork shaft retainer 240 is angled so that the reactive force of the proximal wall of firing fork shaft retainer 240 against firing latch hook 238 rotates firing latch hook 238 further into the firing fork shaft retainer 240 , preventing inadvertent release. The proximal wall of firing latch hook 238 is angled to mate with the angle of the proximal wall of firing fork shaft retainer 240 . After the user has released curved firing lever end 232 , link torsion springs 234 apply torque to curved firing levers 222 and firing linkages 226 rotating them towards each other. Rotating curved firing levers 222 and firing linkages 226 towards each other initiates motion that returns carriage 220 to its distal position. With firing fork 168 held by firing latch 236 while firing levers 222 and firing linkages 226 are in the most distal position, firing mechanism 160 is in the relaxed position shown in FIGS. 18 and 19. When carriage 220 returns to its distal position, curved firing levers 222 contact stops on the sides of raised bosses on upper base shell 161 .
Firing fork shaft 168 has now carried magnet 210 (see FIG. 9) which is located within magnet holder 206 proximally into a position near Hall-effect switch 264 on printed circuit board 262 . Hall-effect switch 264 senses the presence of magnet 210 and communicates with control unit 100 that firing fork 168 is in a proximal position and ready to fire.
Safety latch 250 “guards” firing button 254 . In the locked position shown in FIG. 20, firing button stops 256 on the safety latch 250 are located distally of distal contact surface 255 on firing button 254 . Firing button stops 256 on safety latch 250 are also located on either side of narrow flats 259 (see FIG. 13 ). Smaller firing button outer diameter 258 is larger than the distance between firing button stops 256 . Attempting to push firing button 254 distally will cause distal contact surface 255 to contact firing button stops 256 . The rigidity of the firing button stops 256 in the axial direction prevents further distal movement of the firing button and prevents inadvertent firing of the mechanism.
After the user has determined the proper location in which to insert the piercer 70 of biopsy device 40 into a surgical patient, the user can now unlock and fire firing mechanism 160 . Unlocking and firing the mechanism requires two separate actions, rotating the safety latch 250 and pressing the firing button 254 . The operator first grasps safety latch handle 249 to rotate safety latch 250 against the torque applied to it by safety latch torsion spring 251 (not visible). FIG. 21 shows rotating safety latch 250 so that safety latch handle 249 travels from locked position safety latch stop 245 to unlocked position safety latch stop 243 which aligns firing button stops 256 with wide flats 261 on smaller firing button outer diameter 258 . Since the distance between firing button stops 256 is larger than the distance between wide flats 261 , clearance now exists for wide flats 261 to pass between firing button stops 256 . Safety latch 250 is now in the “firing” position.
In the next step, the operator presses firing button 254 by placing force on cylindrical thumb pad 257 to urge firing button 254 distally. When firing button 254 is pressed, wide flats 261 move between firing button stops 256 allowing firing button 254 to proceed distally. Firing button 254 , attached to firing button shaft 244 , pushes firing button shaft 244 distally. The roller 241 on firing button shaft 244 contacts the cam surface on firing latch 236 to rotate firing latch 236 so that firing latch hook 238 lifts out of firing fork shaft retainer 240 (see FIG. 19 ). Once firing latch hook 238 is clear of firing fork shaft retainer 240 , main spring 217 drives firing fork shaft 168 distally carrying firing fork assembly 164 and piercer 70 of probe assembly 42 towards the target. Distal motion of firing fork shaft 168 continues until shock pad 216 contacts distal interior wall 218 of base shell 38 (see FIG. 14 ). Hall-effect switch 264 senses the departure of magnet 210 distally and communicates the departure to control unit 100 .
After firing the firing mechanism 160 the user releases firing button 254 , then releases safety latch handle 249 . When the user releases firing button 254 , firing button shaft spring 247 forces firing button shaft 244 proximally. Firing button 254 moves proximally as well, returning distal contact surface 255 and firing button smaller diameter 258 proximal of firing button stops 256 . The proximal movement of firing button 254 also places narrow flats 259 between firing button stops 256 . Releasing safety latch handle 249 allows safety latch torsion spring 251 to rotate safety latch 250 back towards the locked position with safety latch handle 249 forced against locked position safety latch stop 245 . With only narrow flats 259 and wide flats 261 between firing button stops 256 , safety latch 250 can freely rotate without interference from firing button stops 256 .
When firing button shaft 244 travels proximally, the roller 241 of firing button shaft 244 and cammed surface of firing latch 236 separate (see FIG. 15 ). Firing latch spring 246 then rotates firing latch 236 into a position where firing latch hook 238 is moved towards firing fork shaft 168 . An arming and firing cycle is now complete. Firing assembly 160 has returned to the post-fired position depicted in FIGS. 14 and 15.
It should be noted that if, after firing, the user of the firing mechanism 160 does not release firing button 254 before releasing safety latch handle 249 , the mechanism still operates properly because of incorporated unique design features. When firing button 254 is in the distal, pressed position, smaller firing button outer diameter 258 is between firing button stops 256 . Clearance for firing button stops 256 is made by alignment of firing button stops 256 with wide flats 261 . Releasing safety latch handle 249 before releasing firing button 254 causes safety latch torsion spring 251 to rotate safety latch 250 back towards the locked position and causes firing button stops 256 to rotate out of alignment with wide flats 261 . When the firing button stops 256 rotate out of alignment with wide flats 261 smaller firing button outer diameter 258 comes between firing button stops 256 . Smaller firing button outer diameter 258 is larger than the distance between firing button stops 256 . However, firing button stops 256 , designed to flex in the radial direction, separate by bending away from each other in the center when forced apart by smaller firing button outer diameter 258 . Because of the radial flexibility of firing stops 256 , firing button stops 256 apply little force to smaller firing button outer diameter 258 . With little force applied, firing button 254 slides easily through firing button stops 256 while returning to the proximal position. Firing button 254 returning to its proximal position brings smaller firing button outer diameter 258 between firing button stops 256 to allow safety latch 250 to continue to rotate back to the locked position. The difference in flexibility of the firing button stops radially and axially allows latching and release of triggering mechanism 235 regardless of order of operation of the components. Rigidity in the axial direction stops inadvertent operation of firing button 254 and flexibility in the radial direction allows interference with smaller firing button outer diameter 258 while still maintaining smooth release operation.
If desired, firing fork assembly 164 can be disassembled without tools from the rest of firing mechanism 160 and cleaned. Before a subsequent firing, an operator can attach a clean firing fork assembly 164 by mating proximal spade end 196 with spade slot 198 and threading firing spacer 188 onto end fitting 166 . When assembling firing fork assembly 164 with the firing mechanism in the post-fired position, an assembler can use depth marker line 189 to ensure proper assembly. The assembler can check alignment of depth marker line 189 with the outside surface of base shell 38 . A depth marker line 189 aligned with base shell 38 denotes a proper assembly. A depth marker line 189 that is misaligned with base shell 38 could indicate an improper assembly such as cross threading of firing spacer 188 or incomplete tightening of firing spacer 188 .
FIG. 22 shows an alternate embodiment of firing fork assembly 164 . Thumbscrew 191 threads into a threaded hole 187 on firing fork 62 . Threaded hole 187 on firing fork 62 passes through to a larger counter bore hole with flats on either side, commonly called a double-D hole 213 . Firing fork assembly 164 comprises thumbscrew 191 threaded onto firing fork 62 . Undercut 195 has an outer diameter less than the minor diameter of threaded hole 187 on firing fork 62 and thus maintains clearance between threaded hole 187 and undercut 195 . Thumbscrew 191 , after assembly to firing fork 62 , can thus turn freely on firing fork 62 utilizing the clearance between threaded hole 187 and undercut 195 . An alternate embodiment of firing fork shaft end fitting 166 , shown in FIG. 22, has end fitting flats 211 machined on either side of the second embodiment of end fitting 166 . End fitting 166 is welded to the distal end of firing fork shaft 168 . The configuration of end fitting 166 with end fitting flats 211 will accept double-D hole 213 of the alternate embodiment of firing fork 62 . Use of end fitting flats 211 with double-d hole 213 prevents rotation of firing fork 62 relative to end fitting 166 and firing fork shaft 168 . The alternate embodiment of firing fork assembly 164 threads into alternate embodiment of end fitting 166 which is welded onto firing fork shaft 168 . The alternate embodiment end fitting 166 has a threaded internal diameter 193 to accept the threaded proximal end of thumbscrew 191 . Thumbscrew 191 has a knurled, easily grasped surface so that the alternate embodiment of firing fork assembly 164 can be assembled and disassembled without the use of tools.
Dual four-bar mechanisms have been utilized in the present embodiment of the invention to facilitate ease of use by providing access by the user from either side of base 44 . A variation that would become evident to one skilled in the art after reading the description would be a single four-bar mechanism to create the firing mechanism.
While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended claims. | The present invention is directed to an improved cable driven surgical biopsy device wherein a transmission assembly is disposed at a proximal end of the biopsy device. The transmission assembly being adapted to convert rotational motion of a cable entering the biopsy device of a substantially right angle into rotational energy to drive the axial cutter in the biopsy device. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of Norwegian patent application Ser. No. NO 20031305, filed Mar. 21, 2003, which is herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention concerns a device and a method to enable disconnection of a tool and a pipe string. More particularly, it concerns a disconnection device to be used especially in connection with coiled tubing operations, in which the connection part attached to the pipe string is of an external transverse dimension that may be equal or smaller than that of the pipe string. The invention also comprises a method of effecting the disconnection.
[0004] During coiled tubing operations, and especially when using a coiled tubing in for example a borehole, a tool attached to the pipe string may become solidly stuck in the borehole to a degree rendering the pipe string useless for pulling it loose.
[0005] Pipe strings are commonly provided with a disconnection device enabling disconnection of the tool and the pipe string, after which the pipe string and the disconnected part of the tool may be retrieved from the borehole. The tool may subsequently be pulled up using fishing tools.
[0006] Known disconnection devices are generally formed with a transverse dimensions larger than that of the pipe strings onto which they are attached. Due to this situation, there can be a problem pulling the part of the connection device connected to the pipe string through restrictions located close to the surface. In the past, this problem as been solved for instance through the use of an explosive charge that is introduced into the pipe string immediately above the connection, after which the connection device part is disengaged through blasting from the pipe string. The pipe string then may be pulled up to the surface.
[0007] Prior to the positioning of the charge, any hydraulic lines and cables present in the pipe string have to be disconnected and retracted to the surface.
[0008] 2. Description of the Related Art
[0009] The object of the invention is to remedy the disadvantages associated with the prior art.
[0010] The object of the invention is achieved through features disclosed in the specification below and in the subsequent claims.
[0011] In accordance with one aspect of the present invention there is provided a disconnection device for disconnecting a tool and a pipe string, the device comprising a first connection part releasably connected to a second connection part by means of a locking device and a release object, wherein at least a section of the release object is soluble.
[0012] At least in preferred embodiments, a first connection part having an outer transverse dimension equal to or less that that of the pipe string is connected, possible via intermediate parts, to the lower end section of the pipe string. By means of an axially split connector ring of known type, the first connection part is releasably connected to a second connection part. The second connection part is connected, possible via intermediate parts, to a tool.
[0013] The split connector ring is maintained in its locking position by means of a pre-stressed locking object aimed in the direction of opening, a release object preventing the locking object from shifting away form its locking position.
[0014] The release object is formed of a material that is soluble by means of, for example, an acid, a base or a solvent.
[0015] During pipe string operations of the stated type, at least one hydraulic pipe is commonly introduced down to the tool inside the pipe string. By connecting this hydraulic pipe to the release object, the object may be dissolved for instance upon pumping acid down through the hydraulic pipe.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] A preferred embodiment of the invention will now be described by way of example only and with reference to the accompanying drawings, in which:
[0017] [0017]FIG. 1 shows a connector placed between a pipe string and a tool, the assembly being located in a borehole;
[0018] [0018]FIG. 2 shows an enlarged view of the connector of FIG. 1, the connector being in its locking position;
[0019] [0019]FIG. 3 shows the connector of FIG. 2 when the release object is weakened, thereby causing a spring to displace the locking object away from its locking position;
[0020] [0020]FIG. 4 shows the connector of FIG. 3 when the split connector ring is displaced away from its locking position, and the first connection part of the connector is being displaced away from the second connection part of the connector; and
[0021] [0021]FIG. 5 shows a smaller scale view of the connector in a released position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] In the figures reference numeral 1 denotes a connector that connects a pipe string 2 with a tool 4 , all of which are placed in a borehole 5 .
[0023] The connector 1 consists of a first connection part 6 which is fixedly attached to the pipe string 2 , and which is of a design enabling it to be displaced into a second connection part 8 in a releasable and locking manner. The second connection part 8 is fixedly attached to the tool 4 .
[0024] The first connection part 6 is provided with a through-going bore 10 , as shown in FIG. 2. The bore 10 is of a relatively large diameter extending from the lower end section of the first connection part 6 and onwards to a shoulder 14 located between the two end sections of the first connection part 6 . The exterior of the first connection part 6 is provided with three encircling grooves 16 matching in a complementary manner an axially split locking ring 18 .
[0025] Axially the locking ring 18 is positioned against a ledge 20 within the second connection part 8 and is held radially in its locking position by means of a locking sleeve 22 displaced inward and over the locking ring 18 . The locking sleeve 22 is displaceably located within a bore 24 of the second connection part 8 .
[0026] A spring 26 for displacing the locking sleeve 22 out of its locking position is placed between the locking sleeve 22 and the first connection part 6 .
[0027] A first hydraulic pipe 28 running through the pipe string 2 is connected to a first coupling nipple 30 . The first coupling nipple 30 is positioned against the shoulder 14 and is connected to a tubular release object 34 via threads 32 . The releasable object 34 forms a portion of a hydraulic circuit.
[0028] A second hydraulic pipe 36 attached to the tool 4 is connected to a second coupling nipple 38 . The second coupling nipple 38 is positioned against the end portion 40 of the locking sleeve 22 and is connected to the tubular release object 34 via threads 42 .
[0029] The release object 34 together with the first coupling nipple 30 and the second coupling nipple 38 thereby prevent the locking sleeve 22 from being displaced out of its locking position.
[0030] Upon disengaging the tool 4 from the pipe string 2 , acid is pumped down through the first hydraulic pipe 28 and down to the release object 34 . Being of a material that is relatively easy to dissolve, for example an aluminium alloy, the release object 34 is partially dissolved after being affected by acid for a period of time. Preferably the release object 34 is provided with a section 44 having reduced wall thickness. The coupling nipples 30 , 38 are provided with seals 46 that prevent acid from flowing out of the bore 10 as the acid is pervasively corroding the release object 34 .
[0031] Having consumed a transverse section of the release object 34 , thereby dividing it into at least two parts, the spring 26 displaces the locking sleeve 22 axially and out of its locking position, as shown in FIG. 3.
[0032] Then the axially split locking ring 18 is displaced radially out of the grooves 16 in the first connection part 6 and outwards into the bore 24 , as shown in FIG. 4. Thereby the first connection part 6 is released from the second connection part 8 , and the connection parts 6 , 8 then may be displaced axially and away from one another, as shown in FIG. 5.
[0033] It will be appreciated that variations in the above described embodiments may still fall within the scope of the invention, which is set out in the accompanying claims. | A disconnection device for disconnecting a tool and a pipe string comprises a first connection part releasably connected to a second connection part by means of a locking device and a release object. The release object is soluble by means of, for example, acid. | 4 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based upon and claims the benefit of prior German Application No. 10 2014 112 825.7, filed on Sep. 5, 2014, the entire contents of which are incorporated herein by reference.
TECHNICAL FIELD
[0002] The present disclosure relates to a radiating element comprising an antenna, which may be separated from an antenna edge by a corrugation, and may be for antenna systems that support bidirectional satellite communication operated in the Ka, Ku or X band for mobile and aeronautical applications.
BACKGROUND OF THE DISCLOSURE
[0003] Demand from passengers on airplanes for multimedia services is on the rise, requiring airplanes to be wirelessly connected to terrestrial data sources or communication networks. Wireless broadband channels for transmitting data at very high data rates may be needed to connect airplanes to a satellite network for the transmission of multimedia data. For this purpose, antennas having small dimensions may be installed on airplanes so as to be installed beneath a radome, but nonetheless satisfy extreme requirements in regard to the sending characteristics for directional wireless data communication with the satellite (such as in the Ku, Ka or X band) because interference from neighboring satellites must be reliably precluded.
[0004] The antenna may be movable beneath the radome so as to track the orientation at the satellite when the airplane is moving. The antenna may be be lightweight so as to cause only little additional fuel consumption of the airplane.
[0005] The regulatory requirements in regard to sending operations are derived from international standards. These regulatory guidelines are intended to ensure that no interference of neighboring satellites can take place in the directional sending operation of a mobile antenna that is mounted on the airplane and sending to a satellite.
[0006] Approaches for compact antennas for aeronautical satellite communication are shown in WO 2014005693, for example, describing ridged horn antennas as single radiating elements. These single radiating elements are arranged in an antenna array and fed high-frequency signals via suitable feed networks. According to WO 2014005693, steps within the ridged horn antenna are used to improve matching of the ridged horn antenna to the free space. However, these steps may result in an increased height.
[0007] Alternative designs of single radiating elements are described in DE 3146273, DE 2152817 and U.S. Pat. No. 4,040,060, with corrugations being introduced into walls of a horn antenna so as to increase the bandwidth of the horn antenna. The corrugations are introduced successively in concentric rings into an edge of the horn antenna for this purpose. U.S. Pat. No. 4,897,663A shows a horn antenna comprising multiple corrugations (chokes), which may be suitable for optimizing the directivity of the single radiating elements for multiple frequencies. These measures may not reduce height.
SUMMARY
[0008] Embodiments of the present disclosure may provide a single radiating element that supports a broad frequency range and has a small height and good matching.
[0009] Embodiments may include a single radiating element and may include an antenna. Other embodiments are disclosed throughout the disclosure.
[0010] A radiating element according to the present disclosure may comprise an antenna element, which may be a ridged horn antenna. The antenna element may have an aperture side, and an aperture that extends into the antenna element. The aperture side may define an aperture area of the antenna element. The antenna element may be surrounded by a radiating element edge, and may be surrounded on the aperture side by the radiating edge. A corrugation may be configured to separate, at least on the aperture side, the antenna element and the surrounding radiating element edge. The radiating element edge may be connected to the antenna element of the radiating element at a distance greater than zero from the aperture side. Multiple such radiating elements may be suitable for forming an antenna if they are arranged next to each other, wherein neighboring radiating elements then have a shared single radiating element edge.
[0011] The single radiating element according to the present disclosure may comprise a ridged horn antenna, which on aperture side may be surrounded by a single radiating element edge separated from the ridged horn antenna by a corrugation. The single radiating element edge may be connected to the single radiating element at a distance from the aperture area. Multiple such single radiating elements may be suitable for forming an antenna if they are arranged next to each other, wherein neighboring single radiating elements then have a shared single radiating element edge.
[0012] Ridges (constrictions) of the ridged horn antenna may lower the cut-off frequency so that size can be reduced for signals having wavelengths that are predefined by the satellite communication. The corrugation may improve matching and may reduce undesirable cross polarization. This arrangement can result in a superimposition of a wave from the ridged horn antenna and the wave from the corrugation, with the corrugation being dimensioned so that an incoming wave into the corrugation which is reflected at a corrugation end structurally superimposes on a wave emerging from the ridged horn antenna.
[0013] In antennas composed of many single radiating elements for satellite communication on vehicles, the installation space for the single radiating element may be automatically limited in the plane of the aperture, and also in the depth. The single radiating elements may therefore be as small as possible. In certain embodiments, the introduction of corrugations may be a disadvantage because installation space for the single radiating element apertures may be lost due to the corrugations in the aperture plane, and the single radiating element aperture may become smaller. Smaller single radiating element apertures, in turn, can mean a higher cut-off frequency, which can cause lower bandwidth. Embodiments of the ridged horn antennas according to the present disclosure are advantageous to remedy this situation because the bandwidth may be broadened again. The corrugations can be used according to the present disclosure to reduce the installation space for particular matching, making the antenna flatter, or to improve matching for a particular installation depth.
[0014] In certain embodiments, the single radiating element edge may advantageously have a rectangular contour, in the center of which the ridged horn antenna is arranged. In this way, multiple such single radiating elements can be easily combined without loss of space. A square contour of the single radiating element edge simplifies this combination in both directions. With a centered arrangement of the ridged horn antenna, the radiation pattern may be oriented toward the center of the single radiating element. When considering that a slight inclination of the radiation pattern to the side of electric field incoupling may be compensated for in the case of electric field incoupling, the arrangement of the ridged horn antenna may also be slightly offset from the center.
[0015] According to a further embodiments, the corrugation may have substantially perpendicular walls in relation to the aperture area, where corrugations open directly to the aperture area and avoid an inclination, which would otherwise result in increased space requirement parallel to the aperture area.
[0016] The number of required ridges may be dependent on the number of polarizations that are supported. The ridged horn antenna may comprise at least two ridges (four in the case of two polarizations), which are each oriented to the ridged horn antenna center and arranged crosswise. The arrangement may be generally symmetrical, so that an angular distance between two ridges is 180° or 90°.
[0017] So as to shift undesirable resonances of the radiated emission of the corrugation with the radiated emission of the ridged horn antenna into a frequency range that is not used, according to embodiments of the present disclosure, a contour of the ridged horn antenna may comprise on the groove side ridges (in the direction of the corrugation, for example) which may influence a volume and a peripheral edge length of the corrugation. These groove-side ridges may be easy to create. The wider the corrugation is dimensioned, the larger may be the supported bandwidth; however, the risk of parasitic modes can increase. An overall width of the ridged horn antenna and the corrugation may be limited by the wavelength of the highest supported frequency that is to be supported.
[0018] If the corrugation of the single radiating element is not sufficient to bring about the desired matching, the ridged horn antenna may be provided with a matching step. However, the number of matching steps may be reduced over a comparable ridged horn antenna having no corrugation.
[0019] Good matching may be achieved when the distance between the aperture area and the connection of the single radiating element edge and the ridged horn antenna is approximately ¼λ, wherein λ refers to a center frequency in a used frequency band.
[0020] When two polarizations are used, they can be frequency-selectively separated from each other when a stepped corrugation is used. For each polarization, the corrugation can be set to the respective optimal λ/4 of the particular center frequency. This means that the distance between the short circuit of the corrugation and the aperture area can vary along the corrugation. This distance may be the same on opposing sides of the single radiating element edge.
[0021] The matching step of the ridged horn antenna may be formed at approximately the same distance from the aperture area as the connection of the single radiating element edge and the ridged horn antenna by way of, for example, milling into a profiled aluminum section. This may simplify production when a matching step is used. This distance may therefore correspond to a thickness of a profiled aluminum section to which a separately produced profiled aluminum section having additional structures of the single radiating element connects.
[0022] A microstrip may be used to couple signals into the ridged horn antenna, where two microstrips may be used when two polarizations are supported. Said microstrips may be coupling signal components that are vertically polarized with respect to each other into the ridged horn antenna. The location of the microstrips may in turn predefine the transition between two profiled aluminum sections.
[0023] Incoupling may furthermore be facilitated in a space-saving manner in that the short-circuited end of the ridged horn antenna may have a ridge that is aligned with a polarization and may have a predefined ridge length. In this way, different short-circuited ends can be created for the two polarizations, wherein the distance of the two microstrips perpendicularly to the aperture area may correspond to the ridge length, and the distance between the one microstrip and the short-circuited end of the ridged horn antenna, and the distance between the other microstrip and the ridge, each may correspond to λ/4.
[0024] The cut-off frequency or the height can be additionally lowered. However, losses may be tolerated when the ridged horn antenna is filled with a dielectric. The corrugation can additionally also be filled with a dielectric.
[0025] By combining multiple such single radiating elements arranged next to each other, an antenna according to the present disclosure comprising multiple single radiating elements may be created, wherein the single radiating elements can be fed via a microstrip network.
[0026] The antenna may therefore be suitable for a bidirectional operation in vehicle-based satellite communication in a frequency band from 7.25 to 8.4 GHz (X band), 12 to 18 GHz (Ku band), and 27 to 40 GHz (Ka band).
[0027] Further advantages and features of the present disclosure will be apparent from the following description of embodiments. The features described in the present disclosure can be implemented alone or in combination. The following description of the embodiments is made with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
[0028] FIG. 1 shows a top view onto a single radiating element according to an embodiment of the present disclosure;
[0029] FIG. 2 shows a sectional view of a single radiating element according to an embodiment of the present disclosure;
[0030] FIG. 3 shows an electric field distribution of a single radiating element in an antenna comprising periodically arranged single radiating elements;
[0031] FIG. 4 shows a top view onto an alternative single radiating element according to an embodiment of the present disclosure; and
[0032] FIG. 5 shows an antenna comprising multiple single radiating elements and a feed network.
DETAILED DESCRIPTION
[0033] FIG. 1 shows a single radiating element having a square contour, which may be formed by a horn antenna edge R, according to an embodiment of the present disclosure. A ridged horn antenna A 1 may be arranged centrally within the contour of the single radiating element. The ridged horn antenna A 1 itself may have a substantially square shape with slightly rounded corners and curvatures, which will be described hereafter in the embodiment according to FIG. 4 . The ridged horn antenna A 1 may be separated from the horn antenna edge R by a corrugation N, which itself can have a substantially square shape and, like the ridged horn antenna A 1 , can be filled with air. Surfaces of the ridged horn antenna A 1 , the corrugation N, and the horn antenna edge R may form the aperture area a.
[0034] The ridged horn antenna A 1 can be characterized by four ridges S 1 to S 4 , which may be arranged crosswise and in the direction of a ridged horn antenna center M. The single radiating element may therefore be able to support two polarizations located perpendicularly on each other. Each of the two ridge pairs S 1 and S 3 , and S 2 and S 4 , formed from two opposing ridges, can support one polarization. As is additionally described in FIG. 2 , two microstrips MS 1 and MS 2 may be located in the interior of the ridged horn antenna A 1 , may couple high-frequency signals into the ridged horn antenna A 1 when sending takes place, and may couple the signals out of the ridged horn antenna A 1 when receiving takes place.
[0035] A radiation pattern of the single radiating element may be formed by the superimposition of signals of the ridged horn antenna A 1 and the corrugation N, as described hereafter. A portion of the signal leaving the ridged horn antenna A 1 can be coupled into the corrugation N. At a corrugation depth of λ/4, with λ being the wavelength of the signal (in the case of broadband signals, approximately the center frequency of the bandwidth), the signal in the corrugation N can traverse 90° to the end of the corrugation N, can be rotated 180° at the end of the corrugation N by a short circuit (zero point), and can traverse the 90° back again to the aperture area a, where the signal may be added at 360° in phase to the signal from the ridged horn antenna A 1 . This may create a standing wave in the corrugation N.
[0036] An embodiment of the single radiating element according to the present disclosure is shown in 3D form in FIG. 2 , with the structures of the ridged horn antenna A 1 , corrugation N, and horn antenna edge R located perpendicularly on the aperture area. There may be a distance I between the connection of the ridged horn antenna A 1 and horn antenna edge R forming the termination (short circuit) of the corrugation N and the aperture area a. The distance 1 may correspond approximately to λ/4. A matching step AP may be arranged within the ridged horn antenna A 1 at approximately the same height as the depth (termination) of the corrugation N, with said ridged horn antenna A 1 being further constricted in this step. Only one matching step AP may be provided in this ridged horn antenna.
[0037] Lateral openings, through which the microstrips MS 1 , MS 2 may be guided, may be introduced into the horn antenna edge R. The microstrips MS 1 , MS 2 may be arranged parallel to the aperture area and perpendicularly to each other, and may be spaced from each other in the direction of the aperture area. The distance 1s' between the microstrips MS 1 , MS 2 may correspond to a length Is of an additional ridge S, which may be arranged at a short-circuited end AB of the ridged horn antenna A 1 and may extend from there into the ridged horn antenna A 1 . The ridge S may be oriented so that it serves as a ridged horn antenna termination for the one of the polarizations. The microstrips MS 1 , MS 2 may therefore each be arranged λ/4 from the ridge S or the short-circuited end AB of the ridged horn antenna A 1 .
[0038] The microstrips MS 1 , MS 2 may be composed of a suspended stripline (SSL), which may be made of a printed circuit board to which a copper strip (copper layer) is applied. The printed circuit board itself may be made of a dielectric having a thickness of 0.1 to 1 millimeters (mm), for example 0.127 mm. The copper strip located thereon may have a width of 0.3 to 1 mm, for example 0.5 mm, and may have a thickness of 15 to 20 micrometers (μm), for example 17.5 μm. The openings at the level of the incoupling may be shaped as narrow slots and may be adapted to the shape of the microstrip MS 1 , MS 2 to allow the microstrips MS 1 , MS 2 to protrude into the ridged horn antenna A 1 . The SSL may be surrounded by metal; therefore, there may be no power losses due to radiated emission out of the structure and as a result of the feedthrough at the slots. By appropriately dimensioning the slots, an interference effect on a field in the ridged horn antenna A 1 may also remain negligible.
[0039] FIG. 3 shows a simulated electric field distribution of the single radiating element of an antenna according to embodiments of the present disclosure, which may be composed of multiple single radiating elements in a periodic arrangement. The signals may be coupled into the ridged horn antenna A 1 by the microstrip MS 1 and reflected at the short-circuited end AB of the ridged horn antenna A 1 . The corrugation N may act as a reflector for the signal from the ridged horn antenna A 1 . Both the fields from the radiating ridged horn antenna A 1 , and the reflected components from the corrugation N, may be added to form a plane wavefront.
[0040] FIG. 4 shows an alternative single radiating element according to embodiments of the present disclosure. This single radiating element may be used for antennas having circular polarization (using a meander-line polarizer) in the X band. For example, Rx may be 7.25 GHz to 7.75 GHz (LHCP), and Tx may be 7.90 GHz to 8.40 GHz (RHCP).
[0041] The corrugation depth I 1 , I 2 may vary. Opposing sections of the corrugation N may have the same depth I 1 or I 2 . Depth I 1 or I 2 may be dimensioned as a function of the polarization supported by the neighboring sections of the horn antenna edge R. The stepped corrugation N may allow the two polarizations to be optimally matched frequency-selectively separate from each other. For each polarization, the corrugation N may be set to the different optimal λ/4. The single radiating element according to FIG. 4 moreover may comprise groove-side ridges s 1 to s 4 , which may protrude from the ridged horn antenna in the direction of the corrugation N and may result in changes of the width of the corrugation N. In this way, undesirable resonances between modes of the waves from the ridged horn antenna and corrugation N may be shifted into frequency ranges in which the antenna is not operated.
[0042] The single radiating element according to embodiments of the present disclosure may be used in antennas comprising multiple single radiating elements, which may be arranged in a shared aperture area. FIG. 5 shows an antenna comprising 16 single radiating elements. A feed network may be composed of microstrips MS 1 and MS 2 , which can feed 8 single radiating elements A 1 to A 8 . A waveguide HL may be arranged centrally within eight single radiating elements A 1 to A 8 , and the signals may be coupled out in two microstrips MS 1 and MS 2 at the two narrow sides of the waveguide HL. These microstrips MS 1 and MS 2 in turn may form microstrip networks, which may connect 4 single radiating elements A 1 to A 4 , or AS to A 8 , to the waveguide HL. The waveguide HL, in turn, may form the terminal of a waveguide network. Waveguide power splitters may be provided. The waveguide network, in turn, may be connected to a transceiver device Tx/Rx, which may receive corresponding signals from the antenna, or send signals to the antenna.
[0043] The feed network having dual magnetic field incoupling may allow a large number of antenna elements to be fed with a minimum of power splitters in the waveguide network.
[0044] By way of such feeding and using single radiating elements according to the present disclosure, light-weight compact antennas can be implemented.
LIST OF REFERENCE NUMERALS
[0045] Aperture area a
[0046] Microstrip MS 1 , MS 2
[0047] Ridged horn antenna A 1 , A 2 to Ax
[0048] Short-circuited end of ridged horn antenna AB
[0049] Transceiver devices Tx/Rx
[0050] Horn antenna edge R
[0051] Corrugation N
[0052] Depth of the corrugation I,I 1 ,I 2
[0053] Ridges of ridged horn antenna S 1 to S 4
[0054] Ridged horn antenna center M
[0055] Matching step AP
[0056] Waveguide HL
[0057] Ridge at ridged horn antenna end S
[0058] Ridge length Is
[0059] Distance of the microstrips Is′
[0060] Groove-side ridges s 1 to s 4 | A radiating element may comprise an antenna element, a radiating element edge, and a corrugation. The antenna element may have an aperture that extends into the antenna element, and an aperture side defining an aperture area of the antenna element. The radiating element edge may surround the antenna element on the aperture side. The corrugation may be configured to separate, at least on the aperture side, the antenna element and the surrounding radiating element edge. The radiating element edge may be connected to the antenna element at a distance greater than zero from the aperture side of the antenna element. | 7 |
This application claims the benefit of provisional application No. 60/304,449, filed Jul. 12, 2001.
FIELD OF THE INVENTION
This invention relates to swimming pool construction and more particularly to a coping structure which is used to cap the upper edge of the wall of the swimming pool.
BACKGROUND OF THE INVENTION
Conventionally swimming pool copings may be made of extruded materials, such as aluminum or plastic. They are positioned usually at the juncture of the vertical swimming pool walls and the horizontal deck which circumscribes the swimming pool and forms the transition piece there between. Copings may be used to retain in place the upper peripheral bead of a swimming pool liner.
The coping is one of the most important elements in a swimming pool structure, particularly in inground or onground swimming pool construction. It is essential to have a reliable and durable coping and important also that the coping be easily secured and useful for a variety of functions including a reliable attachment means for the vinyl liner in pools that use a liner and to attach other accessories such as pool covers and lighting. The coping is subject to much use and frequent abuse because it is invariably stepped on, jumped on and often abused by equipment carried in or near the pool by those using the pool and often bumped by equipment used in servicing the pool. Because of its prominent position just above and surrounding the pool surface, the coping is alway in view by those in the vicinity of the pool and therefore, should present a neat and undistorted appearance.
THE PRIOR ART
It is known that a wide variety of swimming pool copings are in use, including stone, tile, concrete, metal and plastic, each of which is secured to the deck and/or the wall of the pool by a variety of mechanisms, including mechanical attachment, adhesive or being retained with poured concrete. Illustrated prior art copings for example, are those disclosed in U.S. Pat. Nos. 4,901,492, 5,680,730, 5,170,517.
While prior art copings including those disclosed in the above patents have been available in rigid, semi-rigid and flexible materials such copings have been either too cumbersome and have required substantial work to install on the pool on the one hand or in the case of the lighter weight construction copings of the prior and had a tendency to distort and present an unsightly appearance. In addition, all of the prior art coping systems, require installation in sections with seams along the coping. There is no system currently available which can be formed out of one uniform continuous piece of coping around the entire periphery of the pool. In addition, there are currently demands for installing lighting around the coping of the pool in the form of fibre optic lighting which normally is housed within a groove within the coping. The difficulty with lighting is that some pools are installed with lighting and other pools are installed without lighting, thereby giving rise to the need for coping systems which incorporate both options.
There is accordingly a need for coping which is readily installed which affords definite advantageous of versatility which presents an undistorted appearance and promotes maintenance of the swimming pool and which supplies a convenient means for the attachment of a plurality of protective and functional accessories for the pool.
SUMMARY OF THE INVENTION
The present invention a coping for use in a swimming pool, said coping oriented along a longitudinal direction, said coping comprises:
(a) a web disposed along said longitudinal direction, including a means for attaching said web to a side wall of a pool;
(b) wherein said web including a strip section integrally part of said web; and,
(c) a means for irreversibly removing said strip section from a facia of said web to expose an accessory slot defined behind said removed strip section, wherein said accessory slot adapted for attaching accessories to said coping.
Preferably wherein said strip section preferably irreversibly removable by shearing off a longitudinal strip section from said web.
Preferably wherein said facia and strip section preferably made from a flexible plastic material.
Preferably said web including a base including a means for connecting said coping to a sidewall of a pool.
Preferably wherein said web including a first slot oriented along said longitudinal direction and for receiving and retaining a pool liner bead therein.
Preferably wherein said web including a second slot oriented along said longitudinal direction, and for receiving and retaining other pool accessories therein.
An alternate embodiment to the present invention includes a cap for a coping having a longitudinal direction for use in a swimming pool, said cap of the type for co-operatively attaching to a backer, said cap comprises;
(a) a flexible cap web being flexible enough to be installed in one continuous piece onto a backer and around a periphery of a pool.
Preferably wherein:
(a) said cap web including a strip section integrally part of said cap web and a means for irreversibly removing said strip section from a facia of said cap web to expose an accessory slot defined behind said removed strip section, wherein said accessory slot adapted for attaching accessories to said coping.
Preferably wherein said strip section being preferably irreversibly removable by shearing off a longitudinal strip section from said cap web.
Preferably wherein said cap and strip section preferably made from a flexible plastic material.
An alternate embodiment to the present invention includes in combination a coping for use with a swimming pool including a cap and a backer, said coping comprising:
(a) a cap for co-operatively attaching to a backer for supporting and retaining said cap in place; and
(b) a flexible cap web being flexible enough to be installed in one continuous piece onto said backer and around a periphery of a pool.
Preferably wherein:
a) said cap web including a strip section integrally part of said cap web and a means for irreversibly removing said strip section from a facia of said cap web to expose an accessory slot defined behind said removed strip section, wherein said accessory slot adapted for attaching accessories to said coping.
Preferably wherein said strip section being preferably irreversibly removable by shearing off a longitudinal strip section from said cap web.
Preferably wherein said cap and strip section preferably made from a flexible plastic material.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described by way of example only, with references to the following drawings in which:
FIG. 1 is a cross-sectional view of a cap.
FIG. 2 is a front plan elevational schematic view of the cap.
FIG. 3 is a cross-sectional view of the cap.
FIG. 4 is a back plan elevational schematic view of the cap.
FIG. 5 is a top perspective schematic view of the cap.
FIG. 6 is a bottom schematic perspective view of the cap.
FIG. 7 is a top perspective view of the backer.
FIG. 8 is a bottom perspective view of the backer.
FIG. 9 is a cross-sectional view of the cap together with the backer.
FIG. 10 is a back plan elevational view of the backer.
FIG. 11 is a top perspective schematic view of the cap and backer.
FIG. 12 is a cross-sectional view of the cap and backer showing the strip section irreversibly sheared away exposing the accessory slot.
FIG. 13 is a top plan view showing the strip section partially sheared away.
FIG. 14 is a schematic side perspective view showing in schematic fashion the shearing away of the strip portion, by pulling off the strip section.
FIG. 15 is a schematic view of an in ground swimming pool showing in schematic fashion how the coping is installed together with the cap and the backer around the outer periphery of a pool.
FIG. 16 is a schematic perspective front view of a fibre optic lighting strip.
FIG. 17 is a cross-sectional view of the cap and the backer together with the fibre optic strip located in the slot.
FIG. 18 is a front side schematic view of the cap and the backer together with the fibre optic strip located in the slot.
FIG. 19 is an enlarged cross-section view of the cap together with the backer with the strip section in place.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention a coping which is shown generally as 30 to be used at the juncture of a vertical swimming pool wall and a horizontal deck circumscribes the swimming pool and forms the transition piece there between. Coping 30 includes the following major components, namely backer 32 , upon which cap 34 is mounted wherein preferably backer 32 is manufactured from a metallic ductile material such as aluminum and cap 34 is preferably manufactured from a flexible plastic material such as PVC. It should be understood from the outset that it is possible to produce coping 30 as a single unit, wherein backer 32 and cap 34 are integrally the part of one piece having one integral web 98 , either extruded in plastic or in aluminum, having a different cross-sectional profile as shown in FIG. 19 .
Backer 32 includes a base 40 having a base bottom surface 86 , base flange 82 , an anchor aperture 84 , which initially is an indentation 83 for guiding a self taping screw wherein in a fastener 80 preferably a self taping screw fastener passes there through for anchoring said backer 32 onto a swimming pool vertical wall. Backer 32 includes a wall section 42 integrally connected to base 40 defining backer web 102 including a first slot 50 a second slot 52 , lower support 44 , slot support 48 , an anchor flange 54 , an upper support 46 , all of which are integrally connected and normally made of ductile extruded aluminum alloys. The front side of wall section 42 of backer 32 defines a wall facia 43 for receiving of backside 91 of cap 34 thereon.
In the case that coping 30 is made one integral piece, meaning backer 32 and cap 34 are cohesively made from one extruded section, then coping 30 is defined by a single web 98 and as previously described above can be extruded out of metal or plastic materials, and or be made of a composite extension.
Preferably coping 30 is constructed in two pieces, namely backer 32 which is made out of a stiffer metallic and/or plastic material and cap 34 which is mounted onto backer 32 made of a more flexible, preferably plastic and/or PVC material. In this manner, backer 32 provides the structural, strength and retaining support for the more flexible cap 34 which is mounted onto backer 32 .
Cap 34 includes cap web 100 including a hook bottom end 70 , a lower section 60 , a strip section 64 , with a lower shear section 68 and an upper shear section 66 , an upper section 62 and a hooked top end 72 . A backside 91 of cap 34 comes into contact with wall fascia 43 of wall section 42 , of backer 32 .
The front side or exposed portion of cap 34 is shown as fascia 90 which is the visible portion of cap 34 once the construction of the pool has been completed.
Cap 34 includes strip section 64 integrally part of cap web 100 which can be left in situ as shown in FIG. 19 and/or can be sheared along upper shear section 66 and lower shear section 68 by pulling away on one end of strip section 64 , thereby shearing off strip section 64 from cab web 100 and exposing a accessory slot 47 defined by cap 34 once strip section 64 has been removed as shown in FIG. 12, 13 and 14 .
First slot 50 is usually used for fastening the bead of pool liner to coping 30 and second slot 52 is often used for fastening a pool cover in a releasable fashion, or other pool accessories.
With strip section 64 removed, accessory slot 47 is exposed and normally is used to house fibre optic lighting within accessory slot 47 which extends around the outer periphery of the swimming pool.
As already mentioned, cap 34 is normally made of a flexible material such as PVC having an approximate durometer of 93 and being flexible enough such that hook top end 72 can be installed around a rigid upper support 46 as shown in FIG. 19 and hook bottom end 70 can be installed around rigid lower support 44 as shown in FIG. 19 and tabs 71 of cap 34 snap into position in behind upper support 46 and lower support 44 of backer 32 . Cap 34 is flexible enough to install onto backer 30 without special tools and without damaging or breaking hooked ends 70 and 72 . Wherein cap 34 is preferably and normally produced from an extrusion process forming indefinitely long continuous lengths of capping 34 .
In Use
Referring now to all the Figures and in particular referring to FIGS. 15 to 19 , base 40 of backer 32 is mounted onto vertical wall 120 of a swimming pool 118 . Fasteners 80 tap through indentation 83 thereby creating anchor aperture 84 which fastens backer 32 onto vertical wall 120 . Vertical wall 120 can be of various construction, including metal frame work, concrete and/or other materials. Backer 32 being relatively inflexible is normally cut and installed in sections along pool periphery 122 . Backer 32 is ductile and enough to be able to be bent around corners which may exist around the outside pool periphery 122 of a swimming pool 118 . Prior to installing decking 124 which often is poured concrete around the outer periphery 122 of swimming pool 118 , cap 34 is installed onto backer 32 as shown in FIG. 15 . It is possible to use one continuous piece of capping 34 around the entire pool periphery 122 thereby ensuring a seamless installation of one continues piece of capping 34 around the entire pool periphery 122 which butt up on each side to stairs 126 as shown in FIG. 15 . With backer 32 and cap 34 in place, decking 124 is normally installed by pouring concrete around the outer pool periphery 122 as shown in FIG. 15 .
Cap 34 has strip section 64 in situ and one can select whether or not to remove strip section 64 by shearing and removing it from cap 34 . Shearing strip section 64 along upper shear section 66 and lower shear section 68 exposes accessory slot 47 in behind strip section 64 . Strip section 64 is irreversibly removed in this matter since the material from cap 34 is sheared away from itself, thereby leaving an open accessory slot 47 . There is no reason why accessory slot 47 could not later on be covered with some other material other than strip section 64 which has been removed.
Referring now to FIGS. 16, 17 and 18 , preferably with strip section 64 removed from cap 34 , fibre optic lighting 130 having optic fibres 134 housed with in a fibre optic sheath 132 are fed into accessory slot 47 and extends around the entire periphery 122 of swimming pool 118 . In this manner, the user can decide whether or not to install fibre optic lighting and should the user not wish to have fibre optic lighting, strip section 64 remains in place integrally part of cap 34 providing a water proof, water tight seal. Should the user decide to install a fibre optic lighting or some other accessory at any time, strip section 64 could be removed shearably and fibre optic lighting thereafter installed in the exposed accessory slot 47 .
It should be apparent to persons skilled in the arts that various modifications and adaptation of this structure described above are possible without departure from the spirit of the invention the scope of which defined in the appended claim. | The present invention is coping for use in a swimming pool, said coping oriented along a longitudinal direction, and comprises a web disposed along said longitudinal direction, including a means for attaching said web to a side wall of a pool; wherein said web including a strip section integrally part of said web; a strip section being preferably irreversibly removable by shearing off a longitudinal strip section from said cap web for irreversibly removing said strip section from a facia of said web to expose an accessory slot defined behind said removed strip section, wherein said accessory slot adapted for attaching accessories to said coping. | 4 |
[0001] The present invention relates to wound dressings, in particular to an antibacterial wound dressing based on silvered gel-forming fabric and to a process for the manufacture of such a wound dressing.
BACKGROUND OF THE INVENTION
[0002] It has been known for many years that silver is a useful antibacterial agent with broad-spectrum activity together with compatibility with mammalian tissue, and there have been many proposals to incorporate silver into wound dressings to obtain the advantage of the bactericidal properties of silver in a wound dressing. In addition, silver has been applied to fibrous material previously for non-wound dressing purposes, usually for the purpose of enhancing electrical conductivity. Silver has been applied to such fibers, which are generally not gel-forming, in a variety of ways some of which involve immersing the fibers into a silver solution but detail of the procedures used is often lacking.
[0003] Carboxymethyl cellulose, in particular carboxymethylated lyocell, has the ability to absorb a great deal of exudates or wound fluid and to form a gel on its surface. This property of the material has been found to be particularly advantageous in the formation of wound dressings that are both absorbent and gel-forming. The carboxymethylation of cellulose is described in WO93/12275 and the use of carboxymethyl cellulose for wound dressings is described in WO94/16746. Calcium (or sodium/calcium) alginate is another material useful in the formation of wound dressings, because of its absorbency and gelling capability. Gel-forming fibers for use in wound dressings are water-absorbent fibers which become moist and slippery or gelatinous upon the uptake of wound exudate and thus reduce the tendency for the fibers to adhere to the wound. The gel-forming fibers may also swell. Gel-forming fibers can be of the type which retain their structural integrity on absorption of exudate or can be of the type which lose their fibrous form and become a structureless gel or solution on absorption of exudate.
[0004] There have, however been particular problems with the use of silver in wound dressings because of the fact that silver compounds are light-sensitive and darken on exposure to light. This can result in the production of products which have an unattractive visual aspect, even if they are technically suitable for use as wound dressings.
[0005] There are three particular aspects of the darkening of silver compounds in light which need to be addressed when seeking to produce a commercially acceptable silvered wound dressing. One aspect is the actual color of the product, namely the desire to have a product having a color acceptable to the consumer. The second aspect is the desire to produce a product having a uniform appearance. The third aspect is the stability (shelf life) of the color of the dressing within its packaging.
[0006] In the past it has been proposed to apply silver to fibers by a process including the step of contacting the fibers with a solution containing silver ions under conditions which do not cause irreversible gelling of the fibers by contacting the fibers essentially simultaneously with an entire solution containing silver ions. Rapid immersion of the fibers in this way is said to provide a very uniform uptake of silver ions. Such a process is described in U.S. Publication No. 20040241213. However, the immersion takes place in an organic solvent to prevent irreversible gelling of the fibers. Not only might this limit the solvents that can be used, the use of organic solvents might raise environmental and cost issues. The production of fabric from silvered fibers limits the product forms available for use as wound dressings to certain types of fabrics.
[0007] In order to treat certain types of wounds, for example burns or surgical wounds, it is desirable to use a fabric, either woven or non-woven, in order to provide improved properties to the resulting dressing. Such properties can include wet tensile strength, flexibility, reduced brittleness and reduced shrinkage.
[0008] It would be advantageous to have available a process for applying silver to a fabric comprising gel-forming fibers rather than the prior art process for producing silvered fibers and then forming a fabric from them. The process would enable wound dressings with improved properties to be produced which would bring the benefits of silver to more types of wound. It would also be advantageous to have available a process that eliminates the use of an organic solvent in the application of silver.
[0009] Moreover, it would be advantageous to have available a process for producing a hydroentanged non-woven silvered fabric for use as a wound dressing and in particular one comprising hydroentanged carboxymethylcellulose fibers. One possible route to producing such a fabric would be to hydroentangle a cellulosic fabric which is then carboxymethylated and reacted with silver to give it antibacterial properties. Because the fabric is preformed it is not possible to randomize the fibers post treatment with silver. The process for reacting the fabric with silver therefore needs to give a uniform application of silver to the fabric.
[0010] Surprisingly, we have found that silver may be applied to a fabric made of gel-forming fibers by spraying the fabric with a silver solution.
[0011] The processes of the prior art shy away from spraying as the silver solution used to deliver silver ions to the fibers is an aqueous organic solution, especially an aqueous alcoholic solution such as a mixture of ethyl alcohol and water. The solvent is considered necessary to avoid irreversible gelling of the fibers. Generally, the spraying of alcoholic solutions is avoided because of flammability and toxicity issues and the problems they raise in ensuring the safety of the operatives engaged in the process.
[0012] Surprisingly, we have found that it is possible to reduce the level of solvent in the silver solution and even to eliminate it by spraying the fabric with an aqueous silver solution.
SUMMARY OF THE INVENTION
[0013] Accordingly the invention provides a process for producing a silvered wound dressing including the steps of:
(i) forming a fabric comprising gel forming fibers and (ii) contacting the fabric with an aqueous solution containing silver ions by spraying the solution onto the fabric.
[0016] The invention also provides an antibacterial wound dressing derived from gel-forming fibers having silver ions linked thereto, the wound dressing comprising nitrate.
[0017] It is important that the volume of the solution applied to the fabric is adjusted so that essentially the correct dosage of silver is applied to each unit area of the fabric. It is also important not to overwet the fabric otherwise the fibers gel and fuse. It is particularly preferred for the volume of solution with which the fabric is contacted to be adjusted such that essentially all the liquid that is sprayed is taken up by the fabric leaving no free liquid on the surface of the fabric.
[0018] The desired dosage of silver present in a final product is from 0.5% to 8% based on the total weight of the finished product, more preferably 0.5% to 2%, most preferably 0.75 to 1.5%.
[0019] The fabric is preferably sprayed with a solution comprising silver ions and with a separate solution containing sodium chloride. More preferably, the fabric is first sprayed with the silver solution. The sodium chloride solution reduces discoloration of the fabric.
[0020] Preferably, the fabric is in the form of a roll, the spray is applied to both sides of the fabric in a reel to reel process. The two-sided application gives the advantage that the resulting product is not sided and may be used on the patient either way up.
[0021] In conventional liquid spray systems a stream of liquid is made to break up due to the turbulence of the flow pattern within the stream. The liquid breaks up into droplets. This break up is assisted and directed by a compressed air stream and the droplets have velocities in the region of 10 to 20 m per second. Because the process of the invention preferably sprays salt solutions the liquid flow rate must be fast enough to prevent the salt caking on the spray head and blocking it. However, there is a constraint on the amount of fluid that can be sprayed on to the fabric as too much and it will gel and lose integrity. Hence, to use a conventional spray system would require a fast line speed.
[0022] Ultrasonic atomization occurs when a thin film of liquid passes over a surface which is vibrating in a direction which is perpendicular to the surface. The liquid film absorbs some of the energy and starts to vibrate forming standing waves on the surface. These waves are known as capillary waves. If the amplitude of the capillary wave is increased then an amplitude is reached where the wave becomes unstable and collapses. As it does so droplets of liquid are ejected from the surface. These droplets have a velocity in the region of 0.24 to 0.37 m per second. The low velocity of the droplets means that they can be readily entrained in an air stream and deposited on a surface.
[0023] We have found that to give a uniformity of application or coating of the solution on the fabric in order to ideally achieve a uniform dosage of silver on the fabric, the jets used to spray the fabric are preferably of the type which produce a stream of droplets with low forward velocity. By low forward velocity is meant that the droplet falls close to the nozzle and has no appreciable trajectory from the nozzle. The spray droplets are urged downwards onto the fabric by a forced air curtain which directs the spray pattern across the width of the fabric. An ultrasonic spray head has been found to give minimal forward velocity. Preferably, the flow rate of solution applied to each spray head is from 10 ml per minute to 100 ml per minute depending on the line speed of the roll.
[0024] Preferably, the solution containing silver ions is a silver nitrate solution which comprises from 1 % w/w to 10% w/w of silver nitrate in water, more preferably 2% to 7% w/w and most preferably 3% to 5% w/w. Preferably, the sodium chloride solution comprises from 3% to 15% w/w of sodium chloride in water, more preferably 5% to 10% w/w and most preferably 5% to 7% w/w.
[0025] After spraying, the fabric is preferably wound on to a roll and left to react so that exchange can occur with the chloride ions. Typically, the rest time is approximately 5 minutes to one hour at ambient temperature. Following this the wet fabric is preferably unwound and passed through a forced air drier to reduce the fabric water content from 120% to 80% w/w, down to 5% to 15% w/w. Optionally, the fabric can then be treated with UV light so that a uniform color is developed. The energy dissipated by the UV tubes is 3.6 KJm −2 approximately.
[0026] The fabric to be treated is preferably a carboxymethylated hydro entangled non woven fabric since these fabrics provide a compromise between the high strength but low absorbency of woven fabrics and the high absorbency but low strength of needle punched non wovens. More preferably, the fabric is a non-woven, hydroentangled, cellulosic with a basis weight of approximately 55 gsm.
[0027] Preferably, the line speed at which the process operates is from 1 m per minute to 10 m per minute.
[0028] The wound dressing of the invention preferably has a weight to weight ratio of silver to nitrate in the dressing of from 0.5 to 4, more preferably of from 1 to 2 and most preferably of from 1.5 to 1.8.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 is a flow chart of the steps used in one embodiment of the process of the invention.
[0030] FIG. 2 is a flow chart of the spray step used in one embodiment of the process of the invention.
[0031] FIG. 3 shows a flow chart of the dwell step used in one embodiment of the process of the invention.
[0032] FIG. 4 shows a flow chart of the drying/light fixing step used in one embodiment of the process of the invention; and
[0033] FIG. 5 shows a possible machine configuration used in the spray step of one embodiment of the process of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] The invention will now be illustrated by the following examples which show particularly preferred embodiments of the invention.
Example 1
[0035] The process of the invention was carried out using the process steps shown in FIG. 1 .
[0036] The spray coating process was carried out on the machinery arranged as shown in FIG. 5 using the process steps shown in the flow chart of FIG. 2 . The fabric roll (weight up to 8 kg for 300 mm wide rolls and 16 kg for 600 mm wide rolls) was mounted on an unwind unit. The fabric passed from the unwind unit into a booth which contained the spray heads which were used to coat the fabric with a uniform coat weight of silver nitrate solution on both sides of the fabric. The fabric then passed into a second spray booth where it was sprayed with a sodium chloride solution to coat the fabric with a uniform coat weight on both sides of the fabric. The coating process roughly doubled the weight of the processed rolls.
[0037] Once the fabric had been coated, the wet roll of fabric was placed in a plastic bag and kept in the dark for a specified period of time to allow a “curing” process to take place. Once this dwell period had elapsed, the wet roll of fabric was passed to the drying/UV treatment stage. The steps of this process are shown in the flow chart of FIG. 3 . The fabric was held in the dwell stage for a period between 30 minutes and one hour.
[0038] Once the fabric had been allowed to cure for the required time it was passed through a drying stage where the water was removed in an air stream from the fabric and it was dried to a constant water content. Dry fabric was then passed through a UV light treatment where it was exposed to UV light to generate a uniform grey appearance. Once the fabric had been allowed to develop a color it was wound on to package. These process steps are shown in the flow chart of FIG. 4 .
[0039] The process above was carried out on a fabric of 55 to 80 grams per square meter basis weight using the process conditions of Table 1 resulting in the samples of Table 2.
[0000]
TABLE 1
Condition
Value
Line Speed
2 m · min −1
Fabric width
23 cm
Silver nitrate solution feed rate
11 ml · min −1
Sodium chloride feed rate
11 ml · min −1
[0000]
TABLE 2
Aqueous Silver nitrate
Aqueous sodium chloride
Sample
solution concentration % w/w
solution concentration % w/w
US 1
3%
6%
US 2
3%
6%
Example 2
[0040] The samples made in this example where manufactured by a similar process as that outlined in Example 1 except that the ultrasonic spray heads where replaced by conventional spray heads. The process conditions used are shown in Table 3 and the resulting samples in Table 4.
[0000]
TABLE 3
Condition
Value
Fabric width
20 cm
Silver nitrate spray
55.2 kPa
Compressed air feed
Sodium chloride spray
55.2 kPa
Compressed air feed
[0000]
TABLE 4
Sample
CS 1
CS 2
CS 3
CS 4
CS 5
CS 6
Line speed in
1
2
3
1
1
1
m · min −1
Aqueous silver
1.8
1.8
1.8
1.8
2.3
2.6
nitrate solution
concentration
% w/w
Aqueous sodium
6
6
6
7
7
7
chloride solution
concentration
% w/w
Silver nitrate
8.5
17.5
30
8.5
8.5
8.5
solution feed rate
ml · min −1
Sodium chloride
8.5
17.5
30
8.5
8.5
8.5
feed rate in
ml · min −1
[0041] This process could only be operated for a short period of time before the heads blocked.
Example 3
[0042] The ratio of silver to nitrate on a weight to weight basis found in the fabric produced by the process of the invention will be the same as that in the silver nitrate compound sprayed onto the precursor fabric as there are no other sources for either the silver or the nitrate ion and the sprayed fabric is not washed.
[0043] Silver nitrate is AgNO 3 . The relative molecular mass of silver nitrate is 170 g/mol. The relative atomic mass of silver is 108 g/mol. The relative molecular mass of the nitrate ion is 62 g/mol. Hence, the w/w ratio of Silver to nitrate is 108/62=1.74.
[0044] The observed ratios for a fabric of the invention and Aquacel Ag (a carboxymethyl cellulose dressing that has been treated with a silver solution by rapid immersion) are given below. For each sample, the silver concentration present in the sample was measured by breaking down the sample in an acid digest. The resulting solution was measured against known silver standard solutions using atomic absorption spectroscopy. The nitrate concentration was measured by initially washing the samples in de-ionized water. The washings were diluted using de-ionized water. The samples were analyzed by ion chromatography using an ion exchange column in conjunction with an electrochemical detector against standard solutions of nitrate.
[0000]
TABLE 5
Material
% Ag w/w
% NO 3 w/w
Ag/NO 3
Theoretical ratio on a
1.20
0.69
1.74
dressing according to
the invention
US2
1.28
0.84
1.53
US2
1.00
0.30
3.34
CS1
0.58
0.42
1.38
CS2
0.51
0.38
1.33
CS3
0.31
0.36
0.85
CS4
1.30
0.80
1.63
CS5
1.70
1.10
1.55
CS6
2.20
1.10
2.00
Average
1.70
Standard Deviation
0.74
[0045] The theoretical ratio is calculated assuming that silver nitrate is sprayed onto the fabric and hence the ratio of silver to nitrate measured on the fabric is the same as that observed for the pure silver nitrate compound.
[0046] Samples of Aquacel Ag were analyzed as described above to determine the ratio of silver to nitrate in the dressing. The results are shown in Table 6.
[0000]
TABLE 6
Material
Aquacel Ag Material
lot number
% Ag w/w
% NO 3 w/w
Ag/NO 3
21756c
1.24
0.14
8.72
3G65374
1.01
0.10
10.10
4A78987
0.96
0.10
9.60
4E85872
0.93
0.10
9.30
4E85880
1.00
0.10
10.00
A4592
1.11
0.05
22.20
3E70203
0.97
0.10
9.70
Average
11.37
Standard Deviation
4.80
[0047] The theoretical ratio of silver to nitrate for a fabric according to the invention, sprayed with silver nitrate only is 1.74. The observed average ratio of silver to nitrate for the spray process as shown in the table above is 1.70 standard deviation 0.74.
[0048] The observed average ratio for a silvering process involving washing as used in the manufacture of Aquacel Ag is 11.37 standard deviation 4.8. The large difference is not due to the quantity of silver in the fabric according to the invention compared with Aquacel Ag, it is due to the nitrate level which in the fabrics according to the invention is higher because the fabrics are not washed. As illustrated in the following Example, the difference in nitrate content does not affect the essential antibacterial properties of the dressing according to the invention when compared to known antibacterial dressings.
Example 4
[0049] Laboratory testing has shown the dissolution rate for silver from a fabric made by the process of the invention according to Example 1, but reinforced with nylon filaments, is similar to that for AQUACEL Ag (a carboxymethyl cellulose non-woven fabric with silver applied in a non-spray process) using the following method; 2 g of sample was placed in 200 ml of 0.9% (w/v) sodium chloride stirred at 37° C. Testing was carried out on three clinical trial batches of the dressing according to the invention. At selected time points (3 hrs, 24 hrs, etc), 10 ml was sampled and replaced with 10 ml of fresh dissolution medium. The samples were analyzed with an AA Spectrophotometer. A 1000 ppm silver standard was used. Figures show the rate of release (into saline) at each time point. Release is consistent over 160 hrs at approximately 0.4 ppm. Table 7 shows the rate of silver release from Aquacel Ag and the silver dressing of Example 1 reinforced with nylon.
[0000]
TABLE 7
Time (Hours)
Cell
3
24
48
72
96
160
Aquacel Ag-1
0.40
0.35
0.34
0.34
0.35
0.37
Aquacel Ag-2
0.37
0.35
0.35
0.35
0.35
0.37
Aquacel Ag-3
0.39
0.36
0.35
0.35
0.36
0.37
Mean Aquacel Ag 1-3
0.39
0.35
0.35
0.35
0.35
0.37
Ex 1 with nylon Cell-4
0.42
0.43
0.42
0.42
0.42
0.43
Ex 1 with nylon Cell 5
0.42
0.42
0.41
0.42
0.42
0.43
Ex 1 with nylon Cell-6
0.42
0.43
0.42
0.41
0.42
0.44
Mean SHDRwN (Cell-4-6)
0.42
0.43
0.42
0.42
0.42
0.43
Ex 1 with nylon Cell-7
0.42
0.42
0.42
0.41
0.44
0.45
Ex 1 with nylon Cell-8
0.41
0.42
0.42
0.42
0.42
0.45
Ex 1 with nylon Cell-9
0.42
0.42
0.42
0.41
0.41
0.44
Mean SHDRwN (Cell-7-9)
0.42
0.42
0.42
0.41
0.42
0.45 | The present invention relates to wound dressings, in particular to an antibacterial wound dressing based on silvered gel-forming fabric and to a process for the manufacture of such a wound dressing. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is the national stage filing of international application PCT/US2007/081194 filed on Oct. 12, 2007, which claims the benefit of U.S. provisional application 60/829,227 filed on Oct. 12, 2006, both of which are hereby incorporated herewith by reference.
FIELD OF THE INVENTION
This invention is related to wrapped cylindrical bodies and in particular catamenial devices useful in absorbing bodily fluids.
BACKGROUND OF THE INVENTION
Overwrappers for cylindrical bodies and in particular overwrappers for products which can be easily opened but at the same time should be protected from dirt, dust, moisture or other contamination while wrapped such as, for example, catamenial tampons are popular ways to provide individual, portable articles. While the invention will be discussed specifically in terms of catamenial tampons, it will be understood that the problems toward which this invention is directed and their solution applies to many similar products, including, for example, foods, tobacco products and the like.
One method and apparatus for closing a packing tube is disclosed in WO 01/36272 (Buzot et al). In this publication, a packing tube is closed around an essentially cylindrical packaged product. The packing tube is projected beyond a free forward end of the product is pressed together and joined by heated clamping jaws to form a first film sheet. The formed first film sheet portion is then folded over and laid onto the outer surface of packing tube at the forward end. Sealing of the folded sheet is accomplished by application of heated dome shaped pressing head. The inner walls surrounding the recess of the heated pressing head melts the folded sheet with the film of the outer surface of the packing tube. Sufficient heat needs to be applied to melt the three layers of film together. Additionally, the heated jaws need to conform to the geometry or curvature of the insertion end of the tampon in order for the melted film to provide a tight fit of the overwrap.
New development in catamenial tampons now include those that have covers or fluid transport plates such as those disclosed in US 20050256511, US 20050283128 and WO 2005/112860. In these new types of tampons, by-pass leakage is reduced as the fluid transport plates serve to direct fluid to a fluid storage element. One example of such a tampon is one that includes as fluid transport plates a sheet of apertured film, which covers the insertion portion of the fluid storage element and is attached to the fluid storage element by a longitudinal heat seal. This differs from previous tampons in many ways, including the fact that an apertured film covers the insertion portion of the tampon, which typically has been left uncovered. WO 01/01909 discloses a domed tampon having an absorbent structure substantially enclosed by an apertured film cover that has a nonionic surfactant at least partially applied to the cover. The cover overlaps the domed-shaped introduction end but does not completely cover it. One problem encountered in the type of tampon that has a meltable material at the insertion portion of the tampon relates to providing and heat sealing an overwrap. The heat sealing of the overwrap generally occurs at the insertion end and withdrawal end. When heat is supplied to the overwrap material, the apertured film covering the insertion portion of the tampon is also subjected to the heat. The film may melt, the apertures may close and the film may become attached to the overwrap.
What is needed therefore, is a way to seal the overwrap without melting the apertured film covering the insertion portion of the tampon. In particular what is needed is a way to seal a cover or fluid transport element made of a material having a melting point equal to or less than the melting point of the overwrap. One difficulty in overcoming this problem is the geometry of the insertion end of the tampon. This invention solves this problem and provides an overwrapped catamenial device, a method for overwrapping a catamenial device and an apparatus useful for providing this overwrapped catamenial device.
SUMMARY OF THE INVENTION
The process for overwrapping a catamenial device such as a tampon includes:
Providing a cylindrical overwrapper having a length greater than the object it will be overwrapping inserting a catamenial device within the overwrapper such that the overwrapper extends outward from the catamenial device at the insertion end, the cylindrical body having an domed insertion end; heat sealing the overwrapper at the withdrawal end of the cylindrical body contacting the extending overwrapper at the domed insertion end with at least three concave clamping jaws, each clamping jaw heated to a temperature minutes; removing the at least three clamping jaws
wherein the overwrap forms a seam over the insertion end such that the overwrap fins are capable of being folded over to conform to the insertion end of the overwrap.
In one aspect of the present invention, an overwrapped catamenial device for absorbing bodily fluids has a cylindrical body having an insertion end and withdrawal end, the insertion end having a dome shape; and a generally cylindrical overwrapper having a first open end and a second closed end. The ends of the overwrap corresponding to the insertion end and the withdrawal end respectively, and the cylindrical body is contained within the cylindrical overwrap. The first open end of cylindrical overwrap extends beyond the dome and forms at least three radial sections extending from a longitudinal axis, which when sealed together form a flat seam which has a curvilinear arc about said dome and a portion extending away from the dome. This may also include folding the seam toward the dome.
In another aspect of the invention, an apparatus includes a clamping device, and a finishing former. The clamping device has a plurality of sealing jaws, each jaw having a first end and a second end. The first end is heated to a temperature that causes the overwrap to soften, and it is adapted to receive the cylindrical article such that when the first end of the jaws contacts the cylindrical article the overwrap is molded about the cylindrical article and seals to form a plurality of fins having at least 3 radial sections. The finishing former folds the fins over onto the molded overwrap about the cylindrical article.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a perspective view of an overwrapped tampon of the present invention.
FIG. 2 shows a perspective view of a tampon having an insertion end which has a secondary cover.
FIG. 3 shows a perspective view of a tubular overwrap before insertion of a tampon.
FIG. 4 shows a perspective view of a tubular overwrap sealed at the withdrawal end containing a tampon.
FIGS. 5 and 6 show perspective views of tampon having an overwrap sealed by a known method of the prior art.
FIG. 7 shows four views of a single jaw of the present invention:
FIG. 7A shows a plan view of the inner face of the jaw from the longitudinal central axis of the apparatus;
FIG. 7B shows a perspective view of the inner face of the jaw;
FIG. 7C shows a side elevation of the jaw;
FIG. 7D shows a perspective view of the side and outer face of the jaw.
FIG. 8 shows four views of four jaws forming the apparatus:
FIG. 8A shows a side elevation of two opposed jaws of the apparatus with a tampon disposed in the recess of the apparatus;
FIG. 8B shows a perspective view of the two jaws of FIG. 8B in the closed position; and
FIG. 8C shows a perspective view of four jaws in the closed position.
FIG. 9 shows five views of four jaws forming an alternative embodiment of the apparatus:
FIG. 9A shows a side elevation of two opposed jaws of the apparatus with a tampon disposed in the recess of the apparatus;
FIG. 9B shows an end elevation of the two jaws of FIG. 9A from the view of line B-B;
FIG. 9C shows a perspective view of the two jaws of FIG. 9B in the closed position;
FIG. 9D shows a perspective view of four jaws in the closed position; and
FIG. 9E shows an end elevation of the four jaws of FIG. 9D from the view of line E-E.
FIG. 10 shows a perspective view of tampon after sealing by the clamping jaws of the present invention.
FIG. 11 shows a schematic view of a sealed tampon wrapper in a finishing station.
FIG. 12 shows a top plan view of one embodiment of the present invention.
FIG. 13 shows a top plan view of an alternate embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, illustrated in FIG. 1 is an example of a wrapped cylindrical body 10 of this invention. The wrapped cylindrical body 10 has an overwrap 20 and specifically a catamenial tampon 30 , which is shown in greater detail in FIG. 2 . The overwrap 20 is a flexible, tearable, generally moisture and vapor resistant material for the purpose of cleanliness and also to preserve its shape. For the sake of clarity, tear strip 26 is shown only in FIG. 3 .
The tampon 30 has an insertion end 32 and a withdrawal end 34 . The withdrawal end may include a removal string 40 . In FIG. 2 , the withdrawal string is shown in a wound configuration. During use, the user would unwind the removal string and have it extending away from the tampon. In one embodiment, the insertion end is domed. By domed it is meant that the end of the tampon is not flat and has a rounded or hemispherical shape. In another embodiment, the insertion end has a more flattened geometry. This invention can be adapted to any type of geometry that the insertion end of a tampon may have.
As previously stated, uncontrolled sealing of the excess end 22 of the overwrap 20 about the insertion end 32 of the tampon 30 can result in overwrap 20 sticking or being joined to the insertion end 32 of tampon 30 . FIGS. 5 and 6 illustrate two stages commonly known in the prior art for sealing commercially available tampons, and described, e.g., in Simon et al., U.S. Pat. No. 3,856,143. In this process, a tampon is inserted into an overwrap tube that has one end 24 ′ corresponding to the withdrawal end of the tampon sealed. The excess wrapper 22 ′ at the insertion end is twisted causing the overwrap to conform to the surface of the tampon insertion end and forming a rope-like twisted structure 21 ′. Additional material extends beyond the twist 23 ′ (See FIG. 5 ). The twisted 21 ′ and excess 23 ′ material is then folded over and conformed to the insertion end 32 ′ of the tampon 30 ′ ( FIG. 6 ). Sufficient heat is applied to the now-closed end 22 ′ of the overwrap 20 ′ to conform it to the introduction end 32 ′ of the tampon 30 ′. In the event that the overwrap material is not heat-sealable, e.g., cellophane, the heat may be necessary to set the excess material 23 ′ in place. In the event that the overwrap material is heat-sealable, it may be necessary to provide sufficient heat to seal the excess material 23 ′ to the rest of the overwrap material at the introduction end 32 ′ of the tampon 30 ′. The result is an uneven surface having multiple melted layers on the insertion portion of the finished wrapped tampon. Too much heat would melt the layers and be conducted into the fibers of the tampon below the layers. In the tampons of the prior art, this was not an issue as the tampons did not have material such as meltable film covering the insertion end. With the new tampons shown in FIG. 2 and other tampons such as disclosed in Lochte et al. WO 2001/01909, a thermally sensitive material extends further to the introduction end 32 of the tampon 30 . This thermally sensitive material is susceptible to thermal damage during the heat treatment of the overwrap end 22 .
The present invention discloses a process, method and apparatus for sealing the overwrap about a tampon that does not result in the overwrap sticking to the tampon or tampon cover. The process also uses less material than the previous processes, which twist or otherwise form a rope-like structure before folding over and sealing to the outer surface.
In the present invention, multiple clamping jaws are spring mounted onto a fixed hub. The tampon is moved into position and the clamping jaws close about the insertion end of the tampon, pressing the overwrap toward the central longitudinal axis of the tampon (shown FIG. 9 ). Each jaw tip contains a heating element, which is used to preheat the jaw. The jaw momentarily contacts the overwrap, causing the overwrap to surround the insertion end of the tampon and be sealed together. The overwrap may extend beyond the insertion end if excess material is used. The jaws are then released, allowing the tampon to move to the folding station where the excess overwrap is folded and sealed back onto the overwrap covering the insertion end. In this invention the required time or temperature to accomplish the sealing and folding is less than the previous methods as there are fewer and more uniform layers or bulk for the heat to penetrate. For example, in one commercial example (O.b.® tampons, available from Personal Products Company, Skillman, N.J., USA) in which the overwrap was twisted into a rope and then folded over, the excess overwrap required was at least ⅝″ of material. The temperature required to finish the insertion end of the overwrap was about 150 to 200° C. for about 0.2 seconds. In the present invention, the length of the excess material may be decreased by at least about 40% (to about ⅜″). The finishing temperature is decreased to about 1250 to 160° C. with substantially the same dwell time.
Turning to FIGS. 7 and 8 , an example of a jaw of the present invention is shown. As shown, jaw 80 includes contacting end 90 and pivoting end 100 . Contacting end 90 includes a sealing surface 92 and heating element (insertable through bore 94 ), which penetrates into the contacting end 90 such that the contacting surface 92 is capable of being heated to a predetermined temperature. Sealing surface 92 is the edge that extends from a concave recess or receiving area region 98 that is of complementary shape to the insertion end of the tampon and includes leading edge 96 . The overwrap is sealed together by the heat and pressure of sealing surface 92 of a first jaw contacting the sealing surface 92 of a second jaw. Leading edge 96 urges the overwrap toward the central axis A-A of the tampon while sealing surface 92 and concave recess 98 form the base of the overwrap seal such that the tubular overwrap conforms to the surface of the insertion end of the tampon. During the process, the excess overwrap material that protrudes beyond the insertion end of the tampon is held in the concave recess 98 .
In the present invention, there are at least three clamping jaws and may include more. In one embodiment, it has been found that four clamping jaws form an efficient apparatus that seal the excess overwrap, nicely conforming the overwrap about the insertion end of a tampon. The overwrap that protrudes beyond the tampon is sealed in four quadrants about the central longitudinal axis. As more jaws are used, less overwrap material may be required resulting in less waste.
Since sealing surface 92 of the jaw may be preheated before use, the contact time for sealing may be short. In one embodiment, the overwrap material is a polypropylene sheet with a temperature range of about 125° C. to 150° C., for about 0.15 to about 0.3 seconds, preferably about 0.23 seconds. Other materials may have different melting points, so the jaws may be maintained at a temperature appropriate to quickly seal the material used for the overwrap. As the material covering the insertion end of the tampon may have a similar melting point, it is important that the jaws not remain in contact with the overwrap for a long period of time in order to prevent the transfer of heat through the overwrap material.
In one embodiment, the overwrap is sealed using four jaws. The sealing surface 92 and the concave recess area 98 of jaw 80 are uniformly aligned at 0° to the longitudinal axis A-A. This allows the overwrap to be sealed symmetrically into radial sections about the longitudinal axis of the tampon and has the excess material 70 extending along the axis. The sealed radial sections (fins 99 as shown in FIG. 10 ) are then folded to conform to the end surfaces of the overwrap end 22 in a separate finishing station 110 that has a substantially domed recess 112 . Again, the inner sealing surface 114 of this finishing recess 112 may be provided with heating elements to allow the surface to expose the fins 99 to a temperature of about 130-160° C. In this embodiment with substantially longitudinal fins 99 , the finishing may result in squashing of the fins 99 so the material lies close to the surface of the insertion end overwrap (See FIG. 11 ).
In another embodiment, contact surface 92 is positioned at an angle to the longitudinal axis A-A. For example, the angle may be offset sufficient to urge the fins 99 into a pinwheel configuration as shown in FIG. 12 . Preferably, the offset is at least about 5°, and more preferably at least about 10°, e.g., about 12°. A preferred range is about 10° to about 30°, more preferably about 12° to about 24°.
The offset sealing surface 92 ′ forms fins 99 ′ that are at an angle to the longitudinal axis as shown in FIG. 9 . As can be seen in FIG. 9E , the parting lines 101 between the sealing surfaces no longer form an “x” as is the case in the straight structure of FIG. 8 . Instead the inner vertex 103 of the sealing surfaces is offset. This permits them to be folded over in a flatter manner. By using clamping jaws set in an offset angle to the longitudinal axis of the tampon, it is possible to use less heat for finishing the insertion end overwrap as the ultimate thickness of the overwrap is reduced and more uniformly distributed about the insertion end of the package device.
Tampon 30 has a compressed, elongated absorbent structure 36 . The absorbent structure may include a fluid storage element having a longitudinal axis. The absorbent structure may also include ribs and grooves such as those described in EP 0 422 660. In one embodiment shown in FIG. 2 , the absorbent structure is substantially surrounded by a primary cover 50 , which is attached to the sliver prior to compression and a secondary cover 60 , which overlays the primary cover 50 . The secondary cover 60 may form at least one fluid transport element as disclosed in Chase et al., U.S. Ser. No. 10/847,952, published as US 2005-0256511 A1, the disclosure of which is herein incorporated by reference.
In one preferred embodiment, the absorbent structure 36 is an absorbent catamenial tampon 30 . Absorbent tampons are usually substantially cylindrical masses of compressed absorbent material having a central axis and a radius that defines the outer circumferential surface of the tampon. Such tampons are disclosed in e.g., Haas, U.S. Pat. No. 1,926,900; Dostal, U.S. Pat. No. 3,811,445; Wolff, U.S. Pat. No. 3,422,496; Friese et al., U.S. Pat. No. 6,310,296; Leutwyler et al., U.S. Pat. No. 5,911,712, Truman, U.S. Pat. No. 3,983,875; Agyapong et al., U.S. Pat. No. 6,554,814; and Chase et al., US 2005-0256511 A1. Tampons also usually include a fluid-permeable cover (which may include or be replaced by another surface treatment) and a withdrawal string or other removal mechanism. The primary cover 50 is fluid-permeable.
The absorbent structure can be made of any composition known in the art, such as compressed fibrous webs, rolled goods, foam etc. The storage element can be made of any material known in the art such as cotton, rayon, polyester, superabsorbent material, etc.
Fibers may be selected from cellulosic fiber, including natural fibers (such as cotton, wood pulp, jute, and the like) and synthetic fibers (such as regenerated cellulose, cellulose nitrate, cellulose acetate, rayon, polyester, polyvinyl alcohol, polyolefin, polyamine, polyamide, polyacrylonitrile, and the like).
Absorbent materials useful in the formation of the absorbent body include fiber, foam, superabsorbent, hydrogels, and the like. Preferred absorbent material for the present invention includes foam and fiber. Absorbent foams may include hydrophilic foams, foams that are readily wetted by aqueous fluids as well as foams in which the cell walls that form the foam themselves absorb fluid.
A withdrawal mechanism, such as withdrawal string 40 , is preferably joined to the tampon 30 for removal after use. The withdrawal mechanism is preferably joined to at least the tampon 30 and extends beyond at least its withdrawal end 34 . Any of the withdrawal strings currently known in the art may be used as a suitable withdrawal mechanism, including without limitation, braided (or twisted) cord, yarn, etc. In addition, the withdrawal mechanism can take on other forms such as a ribbon, loop, tab, or the like (including combinations of currently used mechanisms and these other forms). For example, several ribbons may be twisted or braided to provide parallel plates structures.
In particular, materials useful for forming the secondary cover 60 (or fluid transport element) may have properties such as thermobondability to provide means to incorporate it into the intravaginal device. A representative, non-limiting list of useful materials includes polyolefins, such as polypropylene and polyethylene; polyolefin copolymers, such as ethylenevinyl acetate (“EVA”), ethylene-propylene, ethyleneacrylates, and ethylene-acrylic acid and salts thereof; halogenated polymers; polyesters and polyester copolymers; polyamides and polyamide copolymers; polyurethanes and polyurethane copolymers; polystyrenes and polystyrene copolymers; and the like. The secondary cover 60 may also be micro-embossed or apertured. Examples of films having apertures include for example, three-dimensional apertured films, as disclosed in Thompson, U.S. Pat. No. 3,929,135, and Turi et al, U.S. Pat. No. 5,567,376, as well as two-dimensional reticulated film, such as that described in Kelly, U.S. Pat. No. 4,381,326. The material used for the secondary cover 60 may have a melting point of less than or equal to the melting point of the overwrap.
The compressed tampon 30 is packaged in an overwrap 20 comprising a polymeric film in contact with the secondary cover 60 and containing the tampon 30 under compression. The overwrap 20 is removable from the compressed tampon 30 during use.
The overwrap 20 may be chosen from a wide variety of commonly used wrapper materials such as polymeric films or metal foils or even treated papers. The overwrap 20 is rolled about the cylindrical tampon and the end 24 is sealed closed by means of heat sealing, by the use of adhesives or by simply twisting, folding or crimping closed. The transverse edge 28 is sealed closed. The wrapper is to be removed from the tampon by pulling up tab 29 located in the transverse edge 28 of the wrapper to tear the wrapper and free the tampon.
EXAMPLE
Example 1
Tampons were made according to US 2005-0256511 A1 and prepared for packaging according to the present invention. The length of excess overwrap material before sealing was measured to be ¼ inch. After sealing to form fins, the overwrap had an excess length of ⅛ inch. The excess was sealed and folded over at a temperature of about 135° C. for 0.23 seconds without damage to the secondary cover of the packaged tampon. | A process for overwrapping a catamenial device such as a tampon includes the steps of providing a substantially cylindrical overwrapper material, inserting a catamenial device into the overwrap material, and closing the open end of the overwrapper material. The overwrapper material has an open end, a closed end, and a first length. The catamenial device has a tapered insertion end, a longitudinal axis, and a length less than the first length, such that the open end of the overwrapper material extends beyond the insertion end of the inserted catamenial device. Concave clamping jaws are applied to the open end of the overwrapper material to urge it toward the longitudinal axis of the catamenial device; to conform portions of the overwrapper material to the insertion end of the catamenial device; and to fold overwrapper material between adjacent clamping jaws to form fins extending outwardly from the conformed portions. | 8 |
FIELD
The present invention relates to detection systems, and more particularly to liquid fuel detection systems.
BACKGROUND
Internal combustion engines combust an air/fuel (A/F) mixture within cylinders to drive pistons and to provide drive torque. Air is delivered to the cylinders and an intake manifold via a throttle. A fuel injection system supplies fuel from a fuel tank to provide fuel from a desired A/F mixture to the cylinders. To prevent release of fuel vapor, vehicles also typically include an evaporative emissions system, which includes a canister that absorbs fuel vapor from a fuel tank, a canister vent valve and a purge valve. The canister vent valve allows air to flow into the canister. The purge valve supplies a combination of air and vaporized fuel from the canister to the intake system.
Closed-loop control systems adjust inputs of a system based on feedback from outputs of the system. By monitoring the amount of oxygen in the exhaust, closed-loop fuel control systems manage fuel delivery to an engine. Based on the output of oxygen sensors, the engine control module adjusts the fuel delivery to match the ideal A/F ratio (14.7 to 1). By monitoring the engine speed variation at idle, closed-loop speed control systems manage engine intake airflows and spark advance.
Under some circumstances, liquid fuel rather than fuel vapor can be present in the canister. Controlling the fuel system when liquid fuel is present in the canister can be a difficult task. Liquid fuel in the canister can produce high engine emissions, undesirable idle surge, steady throttle surge, or engine stall. If this problem occurs, a vehicle may also fail evaporative emissions requirements.
SUMMARY
Accordingly, a liquid fuel detection system for a fuel vapor system of a vehicle providing fuel vapor to an engine operating in closed loop includes an oxygen sensor that generates an oxygen signal based on an oxygen level in engine exhaust. An engine speed sensor generates a speed signal based on a speed of the engine. And a control module receives the oxygen signal and the speed signal, determines a fuel control factor based on the oxygen signal, determines a long term modifier based on long term changes of the fuel control factor, and detects the presence of liquid fuel in the fuel vapor system based on the fuel control factor, the speed signal, and the long term modifier.
In another feature, the control module detects the presence of liquid fuel when the fuel control modifier drops below a minimum for a selectable period of time.
In another feature, the control module detects the presence of liquid fuel in the fuel vapor system when the speed signal and the fuel control factor indicate engine instability.
In other features, the control module detects the presence of liquid fuel in the fuel vapor system when engine idle conditions are met. Engine idle conditions are met if throttle position is less than a minimum throttle position value and vehicle speed is less than a minimum vehicle speed value.
In still other features, the control module sets a liquid fuel notification code when the presence of liquid fuel is detected a selectable number of times and the control module sends an off-board communication signal when the presence of liquid fuel is detected a selectable number of times.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is a functional block diagram of an engine control system and a fuel system according to the present invention;
FIG. 2 is a flowchart illustrating a method of detecting the presence of liquid fuel in the fuel vapor system;
FIG. 3 is a flowchart illustrating a method of checking engine idle conditions;
FIG. 4 is a flowchart illustrating a method of checking engine stability conditions; and
FIG. 5 is a flowchart illustrating a method of checking long term modifier low conditions.
DETAILED DESCRIPTION
The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements. As used herein, the term module refers to an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that executes one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality.
Referring to FIG. 1 , a vehicle 10 includes an engine system 12 and a fuel system 14 . One or more control modules 16 communicate with the engine and fuel systems 12 , 14 . The fuel system 14 selectively supplies liquid and/or fuel vapor to the engine system 12 , as will be described in further detail below.
The engine system 12 includes an engine 18 , a fuel injection system 20 , an intake manifold 22 , and an exhaust manifold 24 . Air is drawn into the intake manifold 22 through a throttle 26 . The throttle 26 regulates mass air flow into the intake manifold 22 . Air within the intake manifold 22 is distributed into cylinders 28 . The air is mixed with fuel and the air/fuel mixture is combusted within cylinders 28 of the engine 18 . Although two cylinders 28 are illustrated, it can be appreciated that the engine 18 can include more or fewer cylinders 28 including, but not limited to 1, 3, 4, 5, 6, 8, 10 and 12 cylinders. The fuel injection system 20 includes liquid injectors that inject liquid into the cylinders 28 .
Exhaust flows through the exhaust manifold 24 and is treated in a catalytic converter 30 . First and second exhaust oxygen sensors 32 and 34 (e.g., wide-range A/F ratio sensors) communicate exhaust A/F ratio signals to the control module 16 . A mass air flow (MAF) sensor 36 is located within an air inlet and communicates to the control module 16 a MAF signal based on the mass of air flowing into the engine system 12 . An engine speed sensor 38 senses the speed of the engine and communicates an engine speed signal to the control module 16 . A throttle position sensor 40 senses the position of the throttle 26 and communicates a throttle position signal to the control module 16 .
The control module 16 controls the fuel and air provided to the engine based on oxygen sensor signals and throttle valve position. This form of fuel control is also referred to as closed loop fuel control. Closed loop fuel control is used to maintain the air/fuel mixture at or close to an ideal stoichiometric air/fuel ratio by commanding a desired fuel delivery to match the airflow. Stoichiometry is defined as an ideal air/fuel ratio, which is 14.7 to 1 for gasoline. The engine control may command different airflow to compensate the engine speed changes during engine idle operation.
The engine system 12 operates in a lean condition (i.e. reduced fuel) when the A/F ratio is higher than a stoichiometric A/F ratio. The engine system 12 operates in a rich condition when the A/F ratio is less than the stoichiometric A/F ratio. A fuel control factor helps determine whether the A/F ratio is within an ideal range, i.e., greater than a minimum value and less than a maximum value. An exemplary fuel control factor includes a short term integrator (STI) that provides a rapid indication of fuel enrichment based on input from the oxygen sensor signals. For example, if the signals indicate an air/fuel ratio greater than a specified reference, STI is increased a step and if the signals indicate an air/fuel ratio less than the specified reference, STI is decreased a step. A fuel control modifier monitors changes in the fuel control factor over a long term. An exemplary fuel control modifier includes a long term modifier (LTM). LTM monitors STI and uses integration to produce its output.
The fuel system 14 includes a fuel tank 42 that contains liquid fuel and fuel vapor. A fuel inlet 44 extends from the fuel tank 42 to enable fuel filling. A fuel cap 46 closes the fuel inlet 44 and may include a bleed hole (not shown). A modular reservoir assembly (MRA) 48 is disposed within the fuel tank 42 and includes a fuel pump 50 . The MRA 48 includes a liquid fuel line 52 and a fuel vapor line 54 .
The fuel pump 50 pumps liquid fuel through the liquid fuel line 52 to the fuel injection system 20 of the engine 18 . A fuel vapor system includes the fuel vapor line 54 and a canister 56 . Fuel vapor flows through the fuel vapor line 54 into the canister 56 . A fuel vapor line 58 connects a purge valve 60 to the canister 56 . The control module 16 modulates the purge valve 60 to selectively enable fuel vapor flow to the intake system of the engine 18 . The control module 16 modulates a canister vent valve 62 to selectively enable air flow from atmosphere into the canister 56 .
Referring to FIGS. 1 and 2 , the steps performed by the control module to detect liquid fuel in the fuel vapor system will be described in more detail. The following method is performed continually when the engine system 12 is operating under closed loop fuel control. Control checks idle conditions to determine if the vehicle 10 is operating at idle at 100 . Control checks engine operating characteristics to determine instability at 110 . If idle conditions are met and the engine operating conditions indicate instability at 120 , control checks LTM low conditions at 130 . LTM low conditions occur when LTM value remains low for a selectable period of time. If idle conditions are not met or engine operating conditions indicate stability at 120 , control returns to checking idle conditions at 100 . If LTM low conditions are met at 140 , liquid fuel is deemed present in the fuel vapor system at 150 . If the LTM low conditions are not met, control returns to check idle conditions at 100 .
Once control detects liquid fuel in the fuel vapor system, control may set a notification code at 160 and a notification signal is sent at 170 . The signal can be in the form of a diagnostic code that can be retrieved by a service tool connected to the vehicle, in the form of a signal that illuminates an indicator light viewable by an operator and/or in the form of a diagnostic code that is broadcast to a remote service technician. Alternatively (flow not shown), control may wait until fuel has been detected in the vapor system a consecutive number of times or a selected number of times within a specified time period before setting a notification signal or sending the notification signal.
Referring now to FIG. 3 , a method of checking idle operating conditions referred to at process box 100 in FIG. 2 will be discussed in more detail. Control evaluates whether the throttle position signal is less than a minimum value at 200 . The minimum value can be selectable. If the throttle position is less than the minimum at 200 , control evaluates the vehicle speed at 210 . If the vehicle speed is less than a minimum speed value at 210 , idle conditions are deemed met at 220 and an idle conditions met flag is set to TRUE. If the throttle position is greater than or equal to the minimum at 200 or the vehicle speed is greater than or equal to the maximum at 210 , idle conditions are deemed not met and the idle conditions met flag is set to FALSE at 230 .
Referring now to FIG. 4 , a method of checking engine stability referred to at process box 110 of FIG. 2 will be discussed in more detail. Control evaluates engine speed at 300 . If engine speed deviates from a desired engine speed a selectable number of times at 300 , control evaluates STI in step 310 . If STI deviates from a selected value (i.e. 100 percent) by a selectable amount and for a selectable number of times, engine is deemed unstable and an engine unstable flag is set to TRUE at 320 . If the engine is stable at 300 and the STI is stable at 310 , the engine unstable flag is set to FALSE at 330 .
Referring now to FIG. 5 , a method of checking LTM low conditions referred to at process box 130 of FIG. 2 will be discussed in more detail. A counter is initialized to zero at 390 . If the LTM is less than or equal to a selectable minimum at 400 , a counter is incremented at 410 . If the counter is greater than a threshold at 420 , a LTM low condition is set to TRUE at 430 . If the counter is less than or equal to the threshold at 420 , control returns to evaluate LTM at 400 . If the LTM is greater than the selectable minimum at 400 , the LTM low condition flag is set to FALSE at 440 .
Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the present invention can be implemented in a variety of forms. Therefore, while this invention has been described in connection with particular examples thereof, the true scope of the invention should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, specification, and the following claims. | A liquid fuel detection system for a fuel vapor system of a vehicle providing fuel vapor to an engine operating in closed loop includes an oxygen sensor that generates an oxygen signal based on an oxygen level in engine exhaust. An engine speed sensor generates a speed signal based on a speed of the engine. And a control module receives the oxygen signal and the speed signal, determines a fuel control factor based on the oxygen signal, determines a long term modifier based on long term changes of the fuel control factor, and detects the presence of liquid fuel in the fuel vapor system based on the fuel control factor, the speed signal, and the long term modifier. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is a Continuation of International Patent Application No. PCT/EP2007/005798 filed on Jun. 29, 2007, entitled, “METHOD AND DEVICE FOR MELT SPINNING AND DEPOSITING SYNTHETIC FILAMENTS INTO A NON-WOVEN MATERIAL”, the contents and teachings of which are hereby incorporated by reference in their entirety.
FIELD OF INVENTION
[0002] Embodiments of the invention relate to methods and apparatus for melt spinning and depositing synthetic filaments into a non-woven material.
BACKGROUND
[0003] In order to produce non-woven materials, it is known that a plurality of synthetic filaments are extruded from a polymer melt, which are deposited into the non-woven material on a deposit belt after cooling by means of a drawing means. For this purpose the filaments are created by means of extrusion means substantially containing an arrangement of nozzle bores in a row such that the filaments are produced as a curtain, and are deposited on the deposit belt.
[0004] It is further known to produce the non-woven material in a non-woven web that is as wide as possible in order to obtain a high production output. A method and a device for melt spinning and depositing synthetic filaments is known, for example, from DE 25 32 900 A1, wherein the synthetic filaments are simultaneously extruded and pulled off next to each other in multiple filament groups by mean of multiple extrusion means that are arranged next to each other. A spreading of the individual filaments of the filament groups is carried out before depositing such that a wide non-woven web is obtained on the deposit belt. In this manner the non-woven material can the produced in a web at a production width of up to 10 m.
SUMMARY
[0005] However, such large production widths require respective treatment units for after-treatment, such as calenders or winding units, in which the non-woven web must be treated in the entire production width thereof. The treatment units must therefore be stabilized accordingly at a greater expense with regard to technical equipment in order to, for example, counteract a bending of the roller extending across the entire production width. Furthermore, the spreading of the filament groups leads to more or less pronounced differences in thickness in the non-woven web. Irregularities in the deposit are unavoidable, particularly in the overlapping regions of adjoining filament groups. When reinforcing the non-woven material, irregularities in the non-woven web cannot be excluded due to the differences in thickness.
[0006] Accordingly, an object is to further improve a method for melt spinning and depositing synthetic filaments into a non-woven material and a device for carrying out the method such that the non-woven material can be produced at a production output that is as large as possible, and such that the same can be uniformly treated in the after-treatment step.
[0007] Another aim is to configure the method for melt spinning and depositing synthetic filaments into a non-woven material and the device for carrying out the method such that a production of the non-woven material that is as flexible as possible, even at high a production output, is possible.
[0008] Certain embodiments are based on the knowledge that the non-woven webs produced are largely cut into so-called usables before final processing. The width of the usables is usually substantially below the production width of the non-woven web. Non-woven webs can be produced by means of the method according to certain embodiments of the invention and by means of the device according to certain embodiments of the invention, which have a production width that is coordinated with the future usables width. For this purpose the filaments of the filament groups are deposited next to each other in separate non-woven webs, and the non-woven webs are guided parallel next to each other. The non-woven material is therefore advantageously formed by multiple non-woven webs that are received and guided parallel next to each other on the deposit belt. As a function of the extrusion means, non-woven webs can be produced at equal production widths, or each having different production widths. For this purpose, two, three, or even more non-woven webs can be deposited and guided parallel next to each other on the deposit belt, wherein a total production width of the system of 10 m or more can be utilized.
[0009] In order to avoid that the edge zones of the individual non-woven webs, and particularly the protruding fibers, get tangled with adjoining non-woven webs, a distance between the non-woven webs is maintained according to an advantageous further improvement of the method such that a gap is created between the non-woven webs on the surface of the deposit belt.
[0010] It has been shown that the productivity during the production of a non-woven material is most favorable, if the production width of the individual non-woven webs exceeds a minimum size. According to an advantageous further improvement the deposit of the filaments is adjusted such that the non-woven web placed through a filament group on the deposit belt takes up a production width in the range of 2 m to a maximum of 6 m.
[0011] The after-treatment of the non-woven web can be carried out collectively or separately as a function of the number of non-woven webs, and as a function of the entire production width on the deposit belt. In a case of a collective after-treatment, the non-woven webs are discharged from the deposit belt parallel next to each other and collectively further treated in one or more treatment steps. For this purpose the same non-woven properties can be created in each of the non-woven webs.
[0012] In a separate after-treatment of the non-woven web it is possible to produce non-woven materials having different properties in one production system. For this purpose the non-woven webs are discharged from the deposit belt, and separately after-treated in one or more treatment steps. Each of the treatment steps of the non-woven web can be individually adjusted to the respectively desired properties of the finished non-woven material.
[0013] For the after-treatment, the non-woven webs preferably are initially reinforced after leaving the deposit belt, and then wound to a sleeve. However, it is also possible to carry out further treatment steps between the reinforcing and winding.
[0014] In order to obtain a filament structure within the non-woven web that is as uniform as possible, the method variation is particularly advantageous, in which the filaments are extruded through multiple nozzle plates arranged next to each other, having a plurality of nozzle bores, wherein the filaments extruded through a nozzle plate form one of the filament groups. In this manner the nozzle plates are substantially adjusted to the production widths of the non-woven webs in order to facilitate the handling of the nozzle plates.
[0015] The nozzle plates may also be held by a spinning beam, or by means of multiple spinning beams arranged next to each other. In an arrangement of the nozzle plates of multiple spinning beams it is also possible to partially maintain the production of the non-woven webs at least during maintenance work. For this purpose, for example, one of the spinning beams, the nozzle plate of which is to be serviced, can be locked from the melt supply such that the production of the non-woven material can be continued using the adjacent spinning beam.
[0016] For the production of a non-woven material, the spinning beams are preferably connected to a melt source supplying one type of a polymer melt each. However, the flexibility during the production of the non-woven material can also be expanded in that the spinning beams are supplied with polymer melts by means of multiple melt sources so that non-woven webs can be produced using different types of polymer.
[0017] In order to carry out the method according to certain embodiments of the invention, the device includes extrusion means and pull-off means in such an arrangement above the deposit belt so that the filaments of the filament groups are deposited next to each other into separate non-woven webs, and that the non-woven webs are guided parallel next to each other.
[0018] The distance between adjacent non-woven webs is within a range of 0.1 m to 0.4 m such that a reciprocal influencing of the non-woven webs on the deposit belt, or on the filament guide, respectively, is impossible.
[0019] The extrusion means preferably have an elongated extension in order to place each of the filament groups allocated by the extruded filaments into a non-woven web on the deposit belt, taking up a production width within a range of 2 m to 6 m. In this manner the distribution of the filaments predetermined by the extrusion means is evenly distributed across the production width of the non-woven web.
[0020] According to an advantageous further improvement of the device, multiple treatment units are connected downstream of the deposit belt going to a collective or separate after-treatment of the non-woven web.
[0021] The treatment units include at least one reinforcement unit and one winding unit, wherein the non-woven webs are reinforced and collectively wound depending on the requirements. However, it is also possible to embody the treatment units such that the non-woven webs are each separately reinforced, and separately wound. In this manner different non-woven qualities can be produced in the non-woven webs.
[0022] According to a particularly preferred embodiment of the device, the extrusion means are formed by means of multiple nozzle plates held next to each other, each having a plurality of nozzle bores, wherein the nozzle bores are preferably held in an arrangement in a row in the nozzle plate. In this manner a high density and uniformity can be produced across a production width defining the non-woven web.
[0023] For this purpose the nozzle plates can be held by a spinning beam in the manner of rows, or by means of separate spinning beams arranged next to each other. In the arrangement in one spinning beam, the nozzle plates are preferably used in order to extrude the extruded filaments of the filament groups from one polymer melt. In the arrangement of the nozzle plates in multiple separate spinning beams, however, it is also possible to produce the filaments associated with the nozzle plates from different polymer melts. For this purpose the spinning beams are preferably supplied by multiple melt sources.
[0024] In order to obtain a uniform distribution of the polymer melt in nozzle plates that are as long as possible, while maintaining retention times that are as constant as possible, multiple dosing pumps are associated with one of the spinning beams each for the melt supply, wherein the spinning beam has a segment-like distribution direction connected upstream of the nozzle plate. For this purpose the production width of the non-woven web can be varied within the filament group via dosing pumps by means of switching individual segments on and off. The same provides further flexibility during the production of non-woven materials and non-woven webs having different production widths.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The techniques according to the invention are explained in further detail based on some example embodiments of devices for carrying out methods, making reference to the attached figures, as follows.
[0000] They show:
[0026] FIG. 1 a schematic view of a first example embodiment of the device according to the invention
[0027] FIG. 2 a schematic top view of a further example embodiment of the device according to the invention
[0028] FIG. 3 a schematic top view of a further example embodiment of the device according to the invention
[0029] FIG. 4 a schematic cross-section of a further example embodiment of a device according to the invention
[0030] FIG. 5 a schematic cross-section of a further example embodiment of the device according to the invention
[0031] FIG. 6 a schematic side view of a further example embodiment of the device according to the invention
[0032] FIG. 7 a schematic top view of the example embodiment of FIG. 6
DETAILED DESCRIPTION
[0033] FIG. 1 shows a schematic view of a first example embodiment of a device for carrying out a method.
[0034] The example embodiment of the device according to the invention includes a deposit belt 1 , being formed of a gas impermeable material, and which is driven in the direction of the arrow at a uniform guide speed. The extrusion means 2 and the pull-off means 3 are arranged above the deposit belt 1 such that a plurality of filaments are guided in filament groups 4 . 1 and 4 . 2 being embodied next to each other in rows to a non-woven web 5 . 1 and 5 . 2 onto the deposit belt 1 . The extrusion means 2 are also formed by two spinning beams 7 . 1 and 7 . 2 , each being connected to a melt source (not illustrated) via a melt supply 6 . The spinning beams 7 . 1 and 7 . 2 have a plurality of nozzle bores at the bases thereof in order to extrude the filaments of the filament groups 4 . 1 and 4 . 2 from one polymer melt.
[0035] The pull-off means 3 is formed by means of two pull-off nozzles 17 . 1 and 17 . 2 arranged next to each other in rows at a distance to the extrusion means 2 . A cooling section is provided between the spinning beams 7 . 1 and 7 . 2 and the pull-off nozzles 17 . 1 ad 17 . 2 for cooling the freshly extruded filaments. The pull-off nozzles 17 . 1 and 17 . 2 are each connected to a compressed air source (not illustrated) in order to pull off the filaments of the filament groups 4 . 1 and 4 . 2 from the spinning area and to convey the same in the direction of the deposit belt 1 . For this purpose the filament group 4 . 1 is guided through the pull-off nozzle 17 . 1 . The filament group 4 . 2 is guided through the pull-off nozzle 17 . 2 to the non-woven web 5 . 2 .
[0036] The non-woven webs 5 . 1 and 5 . 2 are formed next to each other on the deposit belt 1 and discharged in the direction of the arrow by the deposit belt 1 . A distance A is formed between the non-woven webs 5 . 1 and 5 . 2 , which is preferably within a region of 0.1 m to 0.4 m, particularly between 0.2 m and 0.3 m. A gap is formed on the deposit belt 1 by means of the distance A between the non-woven webs 5 . 1 and 5 . 2 such that any contact between the non-woven webs 5 . 1 and 5 . 2 is excluded. The non-woven webs 5 . 1 and 5 . 2 each have a production width denoted in FIG. 1 by the code letters P 1 and P 2 . The non-woven web 5 . 1 has the production width P 1 , and the non-woven web 5 . 2 has the production width P 2 . The production widths P 1 and P 2 of the non-woven webs 5 . 1 and 5 . 2 are preferably embodied equally. However, it is also possible to embody the production width of the non-woven webs 5 . 1 and 5 . 2 with different widths.
[0037] Accordingly, a total production width denoted by the code letter G in FIG. 1 is obtained for the production of the non-woven material. The total production width G is therefore the product of the sum of the production widths of the non-woven webs 5 . 1 and 5 . 2 , P 1 and P 2 , and the distance A.
[0038] The extrusion means 2 and the pull-off means 3 are operated in parallel under preferably the same operating conditions such that each of the non-woven webs 5 . 1 and 5 . 2 has the same non-woven properties.
[0039] A further example embodiment of the device according to the invention for carrying out the method is schematically illustrated in FIG. 2 .
[0040] For this purpose a schematic top view is shown, in which the non-woven deposit and the after-treatment of the non-woven material is illustrated.
[0041] The non-woven deposit is substantially identical to the example embodiment according to FIG. 1 such that reference is made to the previously mentioned description at this point, and only the differences are explained. The non-woven webs 5 . 1 and 5 . 2 guided on the deposit belt 1 are collectively discharged by means of the drive of the deposit belt, and are subsequently guided to multiple treatment units. For this purpose two successively provided treatment units 8 . 1 and 8 . 2 are shown by way of example. After leaving the deposit belt 1 the non-woven webs 5 . 1 and 5 . 2 are successively and collectively guided to the treatment units 8 . 1 and 8 . 2 in order to be treated collectively and simultaneously. For this purpose the treatment may be, for example, the reinforcing of the fiber bond within the non-woven web. A distance is maintained between the non-woven webs 5 . 1 and 5 . 2 during the after-treatment such that a substantially parallel run of the non-woven webs 5 . 1 and 5 . 2 is ensured.
[0042] A further example embodiment of the device according to the invention for carrying out the method is illustrated in FIG. 3 . The example embodiment according to FIG. 3 is substantially identical to the example embodiment according to FIG. 2 such that reference is made to the previously mentioned description at this point, and only the differences are explained.
[0043] In the example embodiment shown in FIG. 3 the non-woven webs 5 . 1 and 5 . 2 are extruded by means of one spinning beam 7 having extrusion means embodied in the form of two nozzle plates. For this purpose the nozzle plates 10 . 1 and 10 . 2 are held at the base of the spinning beam 7 . Such an extrusion means is described in further detail below so that no further explanations are provided at this point.
[0044] For the after-treatment of the non-woven webs 5 . 1 and 5 . 2 separate treatment units are associated with each of the non-woven webs 5 . 1 and 5 . 2 . In this manner the non-woven web 5 . 1 is treated in the successively arranged treatment units 8 . 1 and 8 . 2 . The non-woven web 5 . 2 is treated by the treatment units 8 . 3 and 8 . 4 . For this purpose the treatment units 8 . 1 and 8 . 3 and the treatment units 8 . 2 and 8 . 4 may be embodied identically such that, for example, reinforcement is carried out in one of the first treatment steps, and winding is carried out in a second treatment step. However, it is also possible that the treatments in the treatment units 8 . 1 and 8 . 3 and in the treatment units 8 . 2 and 8 . 4 are embodied and carried out differently on the non-woven webs 5 . 1 and 5 . 2 . In this manner each of the non-woven webs 5 . 1 and 5 . 2 can be treated individually such that a non-woven material can be produced having different properties.
[0045] An extrusion means is schematically illustrated in FIG. 4 , such as the same could be used, for example, for extruding the filament groups in the example embodiment according to FIG. 3 . The extrusion means is formed by a spinning beam 7 . Two nozzle sets 9 . 1 and 9 . 2 arranged next to each other are held within the spinning beam 7 at the base thereof. Each of the nozzle sets 9 . 1 and 9 . 2 is connected to a melt source 14 via a plurality of dosing pumps 12 and multiple melt distributors 13 . By way of example an extruder is shown as the melt source 14 , wherein a plastic granulate is melted into a polymer melt.
[0046] The nozzle sets 9 . 1 and 9 . 2 are each held at the base of the heated spinning beam 7 and are formed by multiple plates. The nozzle sets 9 . 1 and 9 . 2 each have a nozzle plate 10 . 1 and 10 . 2 at the base, including a plurality of nozzle bores 23 , from which the filaments of the filament groups 4 . 1 and 4 . 2 are extruded. The nozzle bores 23 are held in the nozzle plates 10 . 1 and 10 . 2 in a row-like arrangement such that the extruded filaments form a filament curtain. A distribution plate system 11 . 1 and 11 . 2 is connected upstream of each of the nozzle plates 10 . 1 and 10 . 2 , which has a plurality of melt inlets 23 connected to the nozzle bores of the nozzle plate 10 . 1 and 10 . 2 by means of segmented distribution spaces.
[0047] The example embodiment of the extrusion means illustrated in FIG. 4 is particularly suited to uniformly extrude a plurality of filaments within a large production width. A melt supply across all nozzle bores is achieved via the plurality of the dosing pumps and the segmented distribution of the melt such that each of the filaments is extruded at high consistency within the filament groups 4 . 1 and 4 . 2 .
[0048] FIG. 5 illustrates a further example embodiment of an extrusion means, such as could be utilized in the embodiments according to FIG. 1 or 2 , for example.
[0049] The example embodiment illustrated in FIG. 5 is substantially identical to the example embodiment according to FIG. 4 so that reference is made to the previously mentioned description at this point, and only the differences are explained below.
[0050] In the arrangement of the extrusion means illustrated in FIG. 5 the nozzle sets 9 . 1 and 9 . 2 are each held by separate spinning beams 7 . 1 and 7 . 2 . The dosing pumps 12 and the melt distributors 13 . 1 and 13 . 2 associated with the nozzle sets 9 . 1 and 9 . 2 are arranged within the spinning beams 7 . 1 and 7 . 2 . For this purpose the spinning beam 7 . 1 is connected to the melt source 14 . 1 via the melt distributor 13 . 1 and the melt line 15 . 1 . The dosing pumps 12 in the spinning beam 7 . 2 are supplied with a polymer melt by the melt source 14 . 2 via the melt distributor 13 . 2 and the melt line 15 . 2 . In this regard two filament groups 4 . 1 and 4 . 2 differing in the polymer composition thereof can be produced by means of the spinning beams 7 . 1 and 7 . 2 . A high degree of flexibility during the production of non-woven materials, particularly in large-scale systems, can be achieved in this manner.
[0051] However, it is generally also possible to supply the dosing pumps 12 within both spinning beams 7 . 1 and 7 . 2 with a single melt source—as shown in FIG. 4 —such that both filament groups 4 . 1 and 4 . 2 are extruded by filaments of the same composition.
[0052] A further example embodiment of a device according to the invention for carrying out the method is illustrated in FIGS. 6 and 7 , wherein the non-woven webs 5 . 1 and 5 . 2 are wound to sleeves during the final step of an after-treatment. The example embodiment is shown in FIG. 6 in a schematic side view, and in a top view in FIG. 7 . The following description applies to both figures insofar as no reference is made to any one of the figures.
[0053] For the extrusion of the filament groups 4 . 1 and 4 . 2 , two spinning beams 7 . 1 and 7 . 2 arranged in a row are provided, as have been described above, for example. The spinning beams 7 . 1 and 7 . 2 are connected to a melt source via melt supplies 6 . A blowing device 16 is provided below the spinning beams 7 . 1 and 7 . 2 , by means of which a cool air flow directed transversely onto the filament strands is created. For this purpose the blowing device 16 extends across the entire width of the filament groups 4 . 1 and 4 . 2 . Two pull-off nozzles 17 . 1 and 17 . 2 are provided below the blowing device 16 as pull-off means, by means of which the filaments of the filament groups 4 . 1 and 4 . 2 are pulled off and conveyed onto the deposit belt 1 . The non-woven webs 5 . 1 and 5 . 2 are formed on the surface of the deposit belt 1 by means of depositing the filament groups 4 . 1 and 4 . 2 . The non-woven webs 5 . 1 and 5 . 2 are uniformly guided in the direction of the arrow by the deposit belt 1 for after-treatment.
[0054] A reinforcement unit 18 is associated with the deposit belt 1 on the discharge side. The reinforcement unit 18 has two calender rollers 19 . 1 and 19 . 2 substantially extending across the entire production width. The non-woven webs 5 . 1 and 5 . 2 are guided by the nip formed between the calender rollers 19 . 1 and 19 . 2 for reinforcement.
[0055] The guide rollers 10 . 1 and 10 . 2 are provided on the discharge side of the calender rollers 19 . 1 and 19 . 2 in order to feed the non-woven webs 5 . 1 and 5 . 2 to the winding unit 21 at a preferably uniform tension. The non-woven webs 5 . 1 and 5 . 2 are each wound into separate sleeves 22 . 1 and 22 . 2 in the winding unit 21 . For this purpose the sleeves 22 . 1 and 22 . 2 are collectively driven via a spindle. For this purpose the sleeves 22 . 1 and 22 . 2 can be wound both on separate winding carriers and on a mutual winding carrier. The example embodiment shown in FIGS. 6 and 7 is therefore suitable in order to produce, for example, two non-woven webs parallel next to each other, wherein each of the non-woven webs has a production width of, for example, five meters.
[0056] In the previously shown example embodiments the amount of the simultaneously and parallel produced non-woven webs is illustrated by way of example. However, the method and the device according to certain embodiments of the invention are generally not limited to a certain amount of simultaneously produced non-woven webs. For example, three, four, or even more non-woven webs can be produced parallel next to each other on one deposit. Furthermore, certain embodiments also include such solutions, in which the deposit belt is embodied by a deposit drum or other continuous deposit means. The method and the device according to certain embodiments of the invention are particularly suited in order to be able to produce non-woven materials at a high production output. In this manner total production widths of up to 10 m and more are possible, wherein one non-woven material can be produced within the entire production width at a high degree of uniformity. However, the entire production width can also be utilized in order to simultaneously produce non-woven materials with different properties within the total production width.
LIST OF REFERENCE SYMBOLS
[0000]
1 deposit belt
2 extrusion means
3 pull-off means
4 . 1 , 4 . 2 filament groups
5 . 1 , 5 . 2 non-woven web
6 melt supply
7 , 7 . 1 , 7 . 2 spinning beam
8 . 1 , 8 . 2 , 8 . 3 , 8 . 4 treatment unit
9 . 1 , 9 . 2 nozzle set
10 . 1 , 10 . 2 nozzle plate
11 . 1 , 11 . 2 distributor plate system
12 dosing pump
13 , 13 . 1 , 13 . 2 melt distributor
14 , 14 . 1 , 14 . 2 melt source
15 . 1 , 15 . 2 melt line
16 blowing device
17 , 17 . 1 , 17 . 2 pull-off nozzle
18 reinforcement unit
19 . 1 , 19 . 2 calender rollers
20 . 1 , 20 . 2 guide roller
21 winding unit
22 . 1 , 22 . 2 sleeve
23 nozzle bore | A method and a device for melt spinning and depositing synthetic filaments into a nonwoven material are described. The synthetic filaments are extruded and pulled off here simultaneously next to one another in several filament groups and deposited jointly on a belt. Taking into consideration a later final processing of the nonwoven material, the filaments of the filament groups are deposited next to one another to form separate filament webs which are guided next to and parallel to one another. Narrower nonwoven webs can be produced even from very large production widths. For this purpose, the extrusion means and the pull-off means are disposed above the belt in such a manner that the filaments of the filament groups can be laid to form separate nonwoven webs. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 12/146,281, filed Jun. 25, 2008, which claims priority to U.S. Provisional Application Ser. No. 60/946,699, filed Jun. 27, 2007, the entire disclosure of which is incorporated by reference.
TECHNICAL FIELD
This document relates to systems and methods for providing cooling and power to an area containing electronic equipment, such as a computer data center containing server racks.
BACKGROUND
Higher speed computers come with a cost—higher electrical consumption. For a small number of home PCs this extra power may be negligible when compared to the cost of running other electrical appliances in a household. However, in data center applications, where thousands or tens of thousands of microprocessors may be operated, electrical power consumption becomes important.
In addition, the power consumed by a microprocessor is transformed into heat. A pair of microprocessors mounted on a single motherboard can draw 200-400 watts or more of power. If that power draw is multiplied by several thousand (or tens of thousands) to account for the computers in a data center, the potential for heat generation can be appreciated. Thus, not only must a data center operator pay for electricity to operate the computers, it must also pay to cool the computers. The cost of removing heat may be a major cost of operating large data centers.
A typical approach to removing heat in a data center uses air conditioning, e.g., cold air is blown through the room containing the computers. For example, a current common practice is to construct a data center on a raised floor, and use a computer room air conditioner to force cold air through ducts below the floor and up through holes in the floor beneath or between the server racks. The cold air flows over the microprocessors and is heated, and the heated air can be drawn through ceiling ducts back to the computer room air conditioner.
SUMMARY
In one aspect, a facility is described that includes one or more enclosures defining an interior space, a plurality of power taps distributed with a substantially regular spacing in the interior space, a plurality of coolant supply taps distributed with a substantially regular spacing in the interior space, and a plurality of coolant return taps distributed with a substantially regular spacing in the interior space. A flow capacity of the supply taps and a flow capacity of the return taps are approximately equal over a local area of the interior space.
Implementations of the invention may include one or more of the following features. The supply taps and return taps may be connected to a heat exchanger or cooling plant. There need not be local storage or buffering of the coolant in the interior space. The plurality of power taps may be distributed with a substantially regular first spacing in a first direction and with a substantially regular second spacing in a second direction perpendicular to the first direction, the plurality of supply taps may be distributed with a substantially regular third spacing in the first direction and with a substantially regular fourth spacing in the second direction, and the plurality of return taps may be distributed with a substantially regular fifth spacing in the first direction and with a substantially regular sixth spacing in the second direction. The third spacing may be approximately equal to the fifth spacing and the fourth spacing is approximately equal to the sixth spacing. The first spacing may be a ratio N/M of the third spacing, where N and M are both whole numbers less than 5. The second spacing may be an integer N multiple (N) or fraction (1/N) of the fourth spacing, where N is less than five. The first spacing may be approximately equal to the third spacing and the second spacing may be approximately equal to the fourth spacing. The plurality of power taps may be laid along a plurality of first paths, the supply taps may be laid along a plurality of second paths, and the return taps may be laid along a plurality of third paths. The power taps may be disposed with substantially uniform spacing along the first paths, the supply taps may be disposed with substantially uniform spacing along the second paths, and the return taps may be disposed with substantially uniform spacing along the third paths. A spacing of the power taps along the first paths may be less than a spacing between adjacent first paths, a spacing of the supply taps along the second paths may be less than a spacing between adjacent second paths, and a spacing of the return taps along the third paths may be less than spacing between adjacent third paths. The first paths, second paths and third paths may be substantially are substantially linear. A plurality of power delivery busbars may provide power to the plurality of power taps, and the busbars may define the first paths. A plurality of coolant supply manifolds may provide coolant to the plurality of supply taps, and the coolant supply manifolds may define the second paths. A plurality of coolant return manifolds may return coolant from the return taps, and the coolant return manifolds may define the third paths. Each first path of the plurality of first paths may have an associated proximate second path of the plurality of second paths and an associated proximate third path from the plurality of third paths, and each first path may be spaced from the associated proximate second path by a substantially uniform first distance along a substantial length of the first path and each first path may be spaced from the associated proximate third path by a substantially uniform second distance along a substantial length of the first path. There may be a plurality of zones, each zone including a different set of two or more power taps from the plurality of power taps, a different set of two or more supply taps from the plurality of supply taps, and a different set of two or more return taps from the plurality of return taps. The two or more power taps of each zone may be configured to be controllably electrically coupled to a power source independently of the power taps of other zones. The two or more supply taps of each zone may be configured to be controllably fluidly coupled to a coolant source independently of the supply taps of other zones, and the two or more return taps of each zone may be configured to be controllably fluidly coupled to a coolant return independently of the return taps of other zones. The power taps may be spaced at a substantially uniform first density across the interior space, the coolant supply taps may be spaced at a substantially uniform second density across the interior space, and the coolant return taps may be spaced at spaced at a substantially uniform third density across the interior space. The second density may be approximately equal to the third density. Each supply tap may include a spigot, and each spigot may include a valve and a faucet. Each power tap may include a plurality of outlets.
In another aspect, a facility is described that includes one or more enclosures defining an interior space, a plurality of power taps distributed with a substantially regular spacing in the interior space, a plurality of coolant supply taps distributed with a substantially regular spacing in the interior space, and a plurality of coolant return taps distributed with a substantially regular spacing in the interior space. The plurality of power taps, the plurality of supply taps, and the plurality of return taps are divided into a plurality of zones, each zone including a different set of two or more power taps from the plurality of power taps, a different set of two or more supply taps from the plurality of supply taps, and a different set of two or more return taps from the plurality of return taps. The two or more power taps of each zone are configured to be controllably electrically coupled to a power source independently of the power taps of other zones and the two or more supply taps of each zone are configured to be controllably fluidly coupled to a coolant source independently of the supply taps of other zones, and wherein the two or more return taps of each zone are configured to be controllably fluidly coupled to a coolant return independently of the return taps of other zones.
Each zone may be a spatially contiguous area separate from other zones.
In another aspect, a facility is described that includes one or more enclosures defining an interior space, a plurality of power taps positioned along a plurality of first paths in the interior space, a plurality of coolant supply taps positioned along a plurality of second paths in the interior space, and a plurality of coolant return taps positioned along a plurality of third paths in the interior space. Each first path of the plurality of first paths has an associated proximate second path of the plurality of second paths and an associated proximate third path from the plurality of third paths, and wherein each first path is spaced from the associated proximate second path by a substantially uniform first distance along a substantial length of the first path and wherein each first path is spaced from the associated proximate third path by a substantially uniform second distance along a substantial length of the first path.
Implementations of the invention may include one or more of the following features. The power taps may be distributed with a substantially regular spacing, the supply taps may be distributed with a substantially regular spacing, and the return taps may be distributed with a substantially regular spacing. The supply taps and return taps may have the same spacing. A plurality of data taps may be distributed with a substantially regular spacing in the interior space. A plurality of data taps may be positioned along a plurality of fourth paths in the interior space, each first path of the plurality of first paths may have an associated proximate fourth path of the plurality of second paths, and each first path may be spaced from the associated proximate fourth path by a substantially uniform fourth distance along a substantial length of the first path. The power taps may be disposed with substantially uniform first spacing along the first paths, the supply taps may be disposed with substantially uniform second spacing along the second paths, and the return taps may be disposed with substantially uniform third spacing along the third paths. A spacing of the power taps along the first paths may be less than a spacing between adjacent first paths, a spacing of the supply taps along the second paths may be less than a spacing between adjacent second paths, and a spacing of the return taps along the third paths may be less than spacing between adjacent third paths. The first paths, second paths and third paths may be substantially linear. The second paths and the third paths may be uniformly spaced with a first pitch. The second paths may be immediately adjacent to the third paths. Adjacent second paths and third paths may be separated by one-half of the first pitch. The first paths may be uniformly spaced with a second pitch. The second pitch may be an integer N multiple (N) or fraction (1/N) of the first pitch, where N is less than five. The second pitch may be equal to the first pitch. The second paths and third paths may be arranged substantially parallel to the first paths. The first spacing may be a ratio N/M of the second spacing, where N and M are both whole numbers less than 5. The second spacing may be approximately equal to the third spacing. A plurality of power delivery busbars may provide power to the plurality of power taps and the busbars may define the first paths, a plurality of coolant supply manifolds may provide coolant to the plurality of supply taps and the coolant supply manifolds may define the second paths, and a plurality of coolant return manifolds may return coolant from the return taps and the coolant return manifolds may define the third paths. Each supply tap may include a spigot, and each spigot may include a valve and a faucet. Each power tap may include a plurality of power outlets. A flow capacity of the supply taps and a flow capacity of the return taps may be approximately equal over a local area of the interior space. There may be no local storage or buffering of the coolant. The plurality of supply taps and the plurality of return taps may be connected to a heat exchanger or cooling plant. A plurality of cooling coils may remove heat from air near the rack-mounted computers, and the cooling coils may be fluidly connected between the supply taps and the return taps.
Each facility may have an associated method of building the facility including building one or more enclosures, placing power taps, placing coolant supply taps and placing coolant return taps.
In another aspect, a data center is described. The data center includes one or more enclosures defining an interior space, a plurality of power taps distributed with a substantially regular spacing in the interior space, a plurality of coolant supply taps distributed with a substantially regular spacing in the interior space, a plurality of coolant return taps distributed with a substantially regular spacing in the interior space, and a plurality of modules. Each module includes a plurality of rack-mounted computers connected to a power tap adjacent the module and a cooling coil to remove heat from air near the rack-mounted computers, the cooling coil fluidly connected between a supply tap and a return tap adjacent the module.
Implementations can include one or more of the following. A plurality of power lines may have the plurality of power taps, a plurality of coolant supply lines may have the plurality of coolant supply taps, and a plurality of coolant return lines may have the plurality of coolant return taps. The power lines, coolant supply lines and coolant return lines may be substantially linear. The modules may be arranged in substantially linear rows. The linear rows of module may be perpendicular or parallel to the power lines. There may be a power line for each module in a row of the modules or for each row of modules. The linear rows of modules may be perpendicular or parallel to the coolant supply lines and the coolant return lines. There may be a coolant supply line and a coolant return line for each row or every two rows of modules. The power lines may be positioned above of the modules, and the coolant supply lines and the coolant return lines may be positioned below the modules. Each module may be connected to a coolant supply tap on one side of the module and to a coolant return tap on an opposite side of the module, or each module may be connected to a coolant supply tap and to a coolant return tap on the same side of the module. A flow capacity of the supply taps and a flow capacity of the return taps may be approximately equal over a local area of the interior space. The plurality of power taps may be distributed with a substantially regular first spacing in a first direction and with a substantially regular second spacing in a second direction perpendicular to the first direction, the plurality of supply taps may be distributed with a substantially regular third spacing in the first direction and with a substantially regular fourth spacing in the second direction, and the plurality of return taps may be distributed with a substantially regular fifth spacing in the first direction and with a substantially regular sixth spacing in the second direction. The third spacing may be approximately equal to the fifth spacing and the fourth spacing may be approximately equal to the sixth spacing.
In another aspect, a data center is described. The data center includes one or more enclosures defining an interior space, a plurality of power lines, a plurality of coolant supply lines, a plurality of coolant return lines, and a plurality of clusters of modules in the interior space. Each of the power lines includes a plurality of power taps in the interior space, each of the coolant supply lines includes a plurality of coolant supply taps in the interior space, and each of the coolant return lines includes a plurality of coolant return taps in the interior space. Each cluster is located in a spatially contiguous area separate from other clusters, each module includes a plurality of rack-mounted computers connected to a power tap adjacent the module and a cooling coil to remove heat from air near the rack-mounted computers, the cooling coil fluidly connected between a supply tap and a return tap adjacent the module. Each cluster includes two or more modules, and each of the two or more modules is connected to different ones of the plurality of power lines or different ones of the plurality of coolant supply lines and the plurality of coolant return lines.
Implementations may include one or more of the following. Each of the two or more modules may be connected to different ones of the plurality of power lines. Each of the two or more modules may be connected to different ones of the plurality of coolant supply lines and the plurality of coolant return lines. Each of the two or more modules may be connected to different ones of the plurality of power lines and different ones of the plurality of coolant supply lines and the plurality of coolant return lines. Substantially all of the rack-mounted computers of a particular cluster may be dedicated to the same application. The rack-mounted computers of at least two different clusters of the plurality of clusters may be dedicated to different applications. The plurality of power taps may be distributed with a substantially regular spacing in the interior space, the plurality of coolant supply taps may be distributed with a substantially regular spacing in the interior space, and the plurality of coolant return taps may be distributed with a substantially regular spacing in the interior space. The power lines, coolant supply lines and coolant return lines may be substantially linear. The modules may be arranged in substantially linear rows. The linear rows of the modules may be perpendicular to the power lines. The linear rows of the modules may be parallel to the coolant supply lines and the coolant return lines. The power lines may be uniformly spaced. The power lines may be spaced with a pitch approximately equal to a spacing between modules in the rows. The linear rows of the modules may be perpendicular to the coolant supply lines and the coolant return lines. The linear rows of the modules may be parallel to the power lines. The linear rows of the modules may be perpendicular to the power lines, the coolant supply lines and the coolant return lines. The rows of modules may be separated by access aisles. At least two of the coolant supply lines and at least two of the coolant return lines may be connected to different cooling plants. The power taps may be disposed with substantially uniform first spacing along the power lines, the supply taps may be disposed with substantially uniform second spacing along the coolant supply lines, and the return taps may be disposed with substantially uniform third spacing along the coolant return lines. The second spacing may be approximately equal to the third spacing. The coolant supply lines and the coolant return lines may be uniformly spaced with a first pitch. The modules may be distributed with a substantially regular spacing in the interior space.
In another aspect, a method of operating a data center is described. The method includes supplying power to rack-mounted computers in a row of racks from a plurality of power taps extending along the row, supplying coolant to coolant coils in a space adjacent the racks from a plurality of supply taps of a coolant supply manifold extending along the row, and directing warmed coolant from the coolant coils through a plurality of return taps of a coolant return manifold extending along the row.
Implementations of the invention may include one or more of the following. Heat may be removed from the warmed coolant and returning the coolant to the coolant supply manifold. The servers may be located in an interior space, the power taps may be spaced at a substantially uniform first density across the interior space, the supply taps may be spaced at a substantially uniform second density across the interior space, and the return taps may be spaced at spaced at a substantially uniform third density across the interior space.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
FIGS. 1A and 1B are sectional and plan views, respectively, of a facility with cooling and power grids.
FIGS. 2A and 2B are sectional and plan views of the facility of FIGS. 1A-1B operating as a data center.
FIGS. 3A and 3B are sectional and top views of an exemplary computing module.
FIGS. 4-13 are plan views of other implementations of a facility with cooling and power grids operating as a data center.
Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
One issue with using computer room air conditioners for cooling a data center is efficiency. Since air has a low heat capacity, it would be more efficient to place the coolant (e.g., water) closer to the microprocessors. One example of such a technique is to place cooling coils on the sides of a server rack or group of server racks. Such a technique is described by U.S. Patent Application Ser. No. 60/810,452, filed Jun. 1, 2006, the entire disclosure of which is incorporated by reference.
Another issue with any data center is time in bringing a data center into operation; the faster a data center can begin operating the sooner it can generate revenue. Moreover, if a portion of a data center, e.g., one or more server racks, could be brought into operation while other server racks in the data center are still being installed, this would provide significant flexibility in construction and operation while permitting the portion that is operating to meet data processing needs. This issue is exasperated with computer room air conditioners; not only is a facility generally not suitable for installation of server racks until the entire air conditioning system is installed, but if only a portion of the data center is operating then the air conditioning unit must cool the entire room rather than just the operating portion.
FIG. 1A shows a side sectional view of a facility 10 with a power grid 30 , a cooling grid 50 and a “data grid” 70 , before installation of the computers and other components of the data center. FIG. 1B shows a plan view of the facility 10 with the power grid 30 , cooling grid 50 and “data grid” 70 . The facility 10 is an enclosed space and can occupy essentially an entire building, or be one or more rooms within a building. The facility 10 can include a floor 12 (e.g., a concrete slab or a metal sheeting laid over steel beams), a raised floor 14 supported on the floor 12 , a ceiling 16 (which could be the floor of another level of the building) and a suspended ceiling 18 hung from support beams or the ceiling 16 . Doors 19 can be formed in the walls of the facility. Between the raised floor 14 and the suspended ceiling 18 is an enclosed space 20 sufficiently large for installation of numerous (dozens or hundreds or thousands of) server racks.
As shown in FIGS. 1A and 1B , the power grid 30 includes a distributed set of power “taps” 34 , e.g., outlets or receptacles, e.g., sockets. The power taps can be distributed in a line or array of regularly spaced power taps. In operation, the power grid 30 is connected to a power supply, e.g., a generator or an electric utility, and supplies conventional commercial AC electrical power, e.g., 120 or 208 Volt, 60 Hz (for the United States). The receptacles can be conventional commercial power recepticles, e.g., Type B (American 3-pin) (again, for the United States). The outlets can be flush or recessed in the suspended ceiling 18 , or the outlets can hang below the suspended ceiling 18 . The amperage capacity of the busbar 32 can be selected during installation to exceed the expected draw, which can be calculated based on the maximum number of server cabinets that could draw power from that busbar.
As shown in FIG. 1B , the power grid can include power distribution “lines” 32 , such as busbars 32 suspended on or from the ceiling 18 . Each busbar 32 includes the power taps 34 , e.g., the outlets or receptacles. Alternatively, busbars could be replaced by groups of outlets independently wired back to the power supply, e.g., elongated plug strips or receptacles connected to the power supply by electrical whips. Optionally, a group of taps, e.g., the taps along a particular line 32 , can be connected by a common switch or circuit breaker to the power supply so that power can be shut off to the line of taps as a group.
The power taps 34 have a regular spacing, e.g., a regularly repeating pattern of spacing, such as at regular intervals with a spacing D 1 , along the busbar 32 . Each power tap 34 can include a cluster of electrical outlets, e.g., six to twelve outlets, held in an single frame. The power tap 34 can include more than twelve outlets, or as few as a single outlet.
As shown in FIG. 1B , the power grid 30 can include multiple power supply lines, e.g., busbars 32 , spaced evenly across the facility area with a pitch P 1 . Thus, the power “taps” 34 can be distributed uniformly across the space of the facility. The busbars 32 can be connected to a common electrical supply line 36 , which in turn can be connected to the power supply.
FIGS. 2A and 2B show sectional and plan views of the facility 10 with several modules 100 of rack-mounted computers installed. The modules 100 are arranged in rows 102 separated by access aisles 104 . Each module 100 can include multiple racks, and each rack can include multiple trays. The busbars 32 can extend parallel to the row of modules.
As shown, each module 100 is connected to an adjacent power tap 34 , e.g., by power cabling 38 . Assuming that the busbars 32 do run parallel to a row of modules, the spacing D 1 can be equal to or less than the width of a module that is expected to be installed. For example, the spacing D 1 can be about two to six feet. Alternatively, the spacing can be greater than the width W of the module (although probably not more than two or three times the width of a module), in which case the number of outlets can be increased proportionally. The pitch P 1 can be about equal to the pitch between the rows of modules, e.g., six to twelve feet.
Although FIGS. 2A and 2B illustrate the rows of modules 100 as adjacent the busbars 32 , the rows of modules could be directly beneath the busbars. In addition, the busbars 32 need not be suspended from the ceiling, but can run through the plenum 22 between the floor 12 and the raised floor 14 .
Returning to FIG. 1A , the cooling grid 50 includes a coolant, e.g., water, supply manifold 52 and a coolant return manifold 62 which run through the plenum 22 between the floor 12 and the raised floor 14 . Although this specification describes water supply and return manifolds, other cooling fluids or refrigerants could be used. The water supply manifold 52 includes supply “taps” 54 , e.g., water spigots, each having a valve 56 and an outlet 58 that is threaded or otherwise configured, e.g., with a threadless quick-disconnect type fitting, for fastening a hose or pipe. The water supply taps 54 have a regular spacing, e.g., a regularly repeating pattern of spacing, such as at regular intervals with a distance D 2 , along the supply manifold 52 . Similarly, the water return manifold 62 includes return “taps” 64 , each having a valve 66 and an inlet 68 that is threaded or otherwise configured for fastening a hose or pipe (these water inlets can be constructed similarly to conventional spigots, but are for water return rather than supply). The water return taps have a regular spacing, e.g., a regularly repeating pattern of spacing, such as at regular intervals with a distance D 3 , along the return manifold 62 . Each supply “tap” 54 can include a single spigot or a cluster of spigots, and similarly each return tap 64 can include a single inlet or a cluster of inlets. The spigots and inlets can project above the raised floor 14 , or be flush with or recessed in the floor 14 . In some implementations, the spacing D 2 of the water supply taps 54 is the same as the spacing D 3 of the water return taps 64 .
The flow capacity of the supply and return manifolds 52 / 62 can be selected during installation to exceed the expected draw, which can be calculated based on the maximum power available for server cabinets that could draw water from or return water to that manifold. The manifold can be 4-inch or 6-inch diameter piping, e.g., PVC or steel pipe.
The water supply and return manifolds 52 and 62 are connected by a pump 40 and a heat exchanger or cooling plant 42 , which can be located outside the space that actually holds the rack-mounted computers but within or adjacent the same building. The flow capacity of the supply and return manifolds 52 and 62 , the flow capacity of the pump 40 and the capacity of the heat exchanger 42 can be selected before installation for the expected heat based on the power available in the associated busbars.
As shown in FIG. 1B , the cooling grid 50 can include multiple water supply and return manifolds 52 and 62 , spaced evenly across the facility area with a pitch P 2 and P 3 respectively. Thus, the water supply and return “taps” 54 and 64 can be distributed uniformly across the space of the facility. The supply manifolds 52 can be connected to a common water supply line 59 , and the return manifolds 62 can be connected to a common water return line 69 , and the water supply line 59 and water return line 69 can in turn can be connected to the pump 40 and a heat exchanger or cooling plant 42 . A valve can couple each supply manifold 52 and return manifold 62 to the water supply line 59 and water return line 69 so that coolant flow can be shut off to a line of taps (and the associated line of server racks) as a group.
In some implementations, the pitch P 2 of the water supply manifolds 52 can be the same as the pitch P 3 of the water return manifolds 62 . In some implementations, the density of the water return taps 64 (e.g., per unit length of the water return manifold) times the flow capacity per water return tap can be equal to the density of the water supply taps 54 (e.g., per unit length of the water supply manifold) times the flow capacity per water supply tap. The flow capacity per water tap can be adjusted by modulating valves, selecting the number spigots or inlets per tap. In general, the supply and return flow is matched on a local basis (e.g., over several modules) so that there is no local storage or buffering of the water. In some implementations, each water supply tap 54 can be located adjacent a water return tap 64 .
Although FIGS. 2A and 2B illustrate the rows of modules 100 as adjacent the water supply and water return manifolds 52 and 62 , the rows of modules 100 could be directly above the manifolds. In addition, the manifolds need not run through the plenum 22 , but could be suspended from the ceiling.
As shown, each module 100 is connected to an adjacent water supply tap 54 and water return tap 64 , e.g., by flexible hoses 44 and 46 , respectively. Assuming that the manifolds run parallel to a row of modules, the spacing D 2 and D 3 can be equal to or less than the width of a module that is expected to be installed. For example, the spacings D 2 and D 3 can be about four to six feet. If the spacing D 2 or D 3 is greater than the width of the modules, then the number of spigots or inlets would need to be increased. The pitch P 2 and P 3 can be about equal to the pitch between the lines of server racks, e.g., four to twelve feet.
Generally, the spacing D 1 is related to the spacing D 2 and D 3 , and the pitch P 1 is related to the pitch P 2 and P 3 . In a simple implementation as shown in FIGS. 1A-2B , the pitches P 2 and P 3 of the manifolds of the cooling grid are equal the pitch P 1 of the busbars of the power grid. In addition, the spacings D 2 and D 3 of the cooling grid taps are equal to the spacing D 1 of the power taps. For example, the cooling grid taps can be spaced 2 feet apart, whereas the power grid taps can have a spacing of 600 millimeters.
Returning to FIG. 1A , the “data grid” 70 (the data grid is not shown in FIG. 1B due to lack of space) includes data cabling 72 and data “taps” 74 , e.g., data outlets, for connection to the rack-mounted computers. The cabling can be conventional Cat-5 or Cat-6 or CX-4 or optical cabling, and the data outlets can be conventional modular receptacles. Each data tap 74 can include a cluster of data outlets, e.g., 180 outlets. The data taps 74 have a regular spacing, e.g., a regularly repeating pattern of spacing, such as at regular intervals with a distance D 4 , along the string of cabling 72 . The data cabling 72 can be suspended from the ceiling as shown or run through the plenum 22 between the floor 12 and the raised floor 14 . Alternatively, data cabling could run directly to the rack-mounted computers without an intervening receptacle. Groups of cables, e.g., the data cables from a rack of rack-mounted computers, a row of racks, or a line of computer modules, can be connected to an intervening switch or patch board.
The data grid 70 can include multiple cabling bundles 72 , spaced evenly across the facility area with a pitch P 4 (not shown). Thus, the data “taps” 74 can be distributed uniformly across the space of the facility.
As shown in FIG. 2A , each rack-mount module 100 is connected to an adjacent data tap 74 by data cabling 78 , e.g., by additional Cat-5 or Cat-6 cabling. The data cabling 72 can extend parallel to the row of modules. Assuming that the data cables 72 run parallel to a row of modules, the spacing D 4 can be equal to or less than the width of a module that is expected to be installed. For example, the spacing D 4 can be about four to six feet. Alternatively, the spacing can be greater than the width of the module, in which case the number of data receptacles can be increased proportionally.
The spacing D 4 can be related to the spacing D 1 , D 2 and D 3 , and the pitch P 4 can be related to the pitch P 1 , P 2 and P 3 . In a simple implementation as shown in FIGS. 1A-2B , the pitches P 4 of the data cabling 72 is equal to the pitch P 1 of the busbars of the power grid and the spacing D 4 of the data taps is equal to the spacing D 1 of the power taps.
In general, the rows of modules 100 extend along the same path, e.g., are linear and parallel to, the busbars 32 , water supply manifolds 52 and water return manifolds 62 . In the implementation illustrated in FIGS. 1A-2B , there is one row of modules 100 per busbar 32 , water supply manifold 52 and water return manifold 62 . However, as discussed below, many other layouts are possible.
In some implementations, the rack-mounted computers are grouped (e.g., a group can be the computers in the modules along a particular path, such as a row of modules), and the power and coolant flow can be independently shut on and off for each group, e.g., power and coolant can be shut off for one row of modules so that the computers in that group are disabled, while power and coolant continue to flow and the computers continue to operate in another row of modules. However, in some layouts, it may be possible to shut off coolant to a group of modules (e.g., multiple rows), whereas power can be shut off independently to sub-groups within the group (e.g., individual rows).
FIGS. 3A and 3B are side and top views of a rack-mount computer module 100 that can be installed in the facility. The module 100 includes two parallel rows 110 of racks 120 separated by a space 112 . Each row 110 in the module 100 can include several, for example, two to five, e.g., three, racks 120 placed side-by side. Each rack 120 can include several dozen vertically stacked trays 122 , with approximately several inches between each tray. The term “tray” is not intended to refer to a particular form factor, but refers to any arrangement of computer-related components coupled together so as to be removable from the rack as a unit. Moreover, the term “computer module” or “rack-mounted computer” includes not just rack-mounted computers, e.g., servers, but also racks of other communications and data processing equipment, such as network gear, e.g., switches and routers.
In general, each tray 122 can include a circuit board, such as a motherboard, on which a variety of computer-related components are mounted. Trays can be implemented for particular functional purposes, such as computer servers (whether for electronic mail, search requests, or other purposes), network gear (such as switches or routers), data storage (with a drive or group of drives). A given rack can include trays dedicated to a single function, or a rack can include a mix of trays with different functions. In general, trays in a data center have a standardized physical and power-coupling form so as to be easily interchangeable from one location in the data center to another (e.g., from one slot on a rack to another slot or from one rack to another rack). Trays for a given functional purpose can also have a standardized form for the physical layer of their input/output interface. For operation, each circuit board will be connected both to the power grid, e.g., by wiring that first runs through the rack itself and which is further connected by power cabling to a nearby power tap 34 , and to the data grid, e.g., by data cabling that is connected to a nearby data tap 74 .
Cooling coils 130 are located in the space 112 between the rows 110 of racks 120 . For operation, one end of the cooling coil 130 is connected, e.g., by a flexible hose 44 , to a nearby water supply tap 54 and the other end of the cooling coil 130 is connected, e.g., by a flexible hose 46 , to a nearby water return tap 56 . In addition, fans 132 can be placed on the walls of the racks and above the space and be powered by the busbar.
In operation, cool water will be pumped through the supply manifolds and into the cooling coil 130 via the taps 54 . The fans 132 will draw air across the trays 122 into the space 112 , thereby removing heat from the microprocessors in the trays. This warmed air is drawn through the cooling coils 130 and directed up through the top of the space 112 . The cooling coils 130 transfer heat from the air passing through the space 112 to the water in the coils, and the warmed water is drawn through the return taps 56 and return manifolds back to the heat exchanger or cooling plant 42 .
FIG. 4 is a plan view of an implementation of a facility with a cooling and power grids and operating as a data center with two rows of modules 100 per busbar 32 , water supply manifold 52 and water return manifold 62 . Each module 100 is connected to an immediately adjacent grid. Thus, at least some of the busbars 32 , water supply manifolds 52 and water return manifolds 62 are connected to rows of modules 100 on opposite sides. This permits the water supply and return manifolds 52 and 62 to be placed beneath the flooring of the aisles 104 separating the modules 100 where the manifolds can be more easily serviced. Although some of the modules are illustrated as adjacent, if the modules have racks on opposite sides, then the modules would need to be spaced apart to provide an aisle for personnel access.
The implementation shown in FIG. 5 is similar to FIG. 4 , but a power busbar 32 is disposed over each row of modules 100 . Thus, in this layout, the pitches P 2 and P 3 are two times greater than pitch P 1 and are offset from pitch P 1 by about P 1 /2.
FIG. 6 is a plan view of another implementation of a facility with cooling and power grids and operating as a data center. As shown, the spacings D 1 , D 2 and D 3 are equal and the pitches P 1 , P 2 and P 3 are equal, but the power busbars 32 are spaced a half-pitch P 1 or P 2 from the water supply and return manifolds 52 and 62 . In addition, each module 100 can be connected to a supply manifold 52 and a return manifold 62 that are located on opposite sides of the module. Thus, in this layout, the supply manifold 52 and return manifolds are offset by substantially an entire pitch P 1 or P 2 . This configuration permits the busbars 32 to run directly over the modules 100 , but water supply and return manifolds 52 and 62 can be placed beneath the flooring of the aisles 104 separating the modules 100 where the manifolds can be more easily serviced. In addition, if any manifold has to be shut down, then only the single row of computers components serviced by that manifold would also need to be shut down.
FIG. 7 is a plan view of another implementation of a facility with cooling and power grids and operating as a data center. As shown, rather than having immediately adjacent water supply and return manifolds 52 and 62 , each water supply manifold 52 is separated from the nearest water return manifold 62 by a row of modules 100 . Thus, the pitches P 2 and P 3 are two times greater than pitch P 1 . The spacings D 1 , D 2 and D 3 can be equal, but the minimum number of spigots and inlets at each tap (excepting those along the edges of the room) would be twice the minimum number for the implementations shown in FIG. 5 . This reduces the amount of installed pipe and thus can reduce construction cost and time, but if any manifold has to be shut down then two rows of modules will be also need to be shut down.
FIG. 8 is a plan view of another implementation of a facility with a cooling and power grids operating as a data center. In this implementation, each pair of water supply and return manifolds 52 and 62 is separated by multiple rows, e.g., four or fewer rows, of modules 100 . Thus, the pitches P 2 and P 3 are two or more times greater than pitch P 1 (only one supply manifold is shown in FIG. 8 due to space limitations, and thus pitch P 2 is not illustrated). The spacings D 1 , D 2 and D 3 can be equal, but the minimum number of spigots and inlets at each tap would be two or more the minimum number for the implementations shown in FIG. 7 . Although this uses longer hoses than the implementation shown in FIG. 7 , it reduces the amount of installed pipe and thus reduces construction cost and time. Of course, the features of FIGS. 4 and 5 could be combined with each water supply manifold 52 separated from the nearest water return manifold 62 by multiple rows of modules 100 . In addition to or instead of the water supply and return manifolds being separated by multiple rows of modules, the electrical busbars 32 could be separated by multiple rows, e.g., four or fewer rows, of modules 100 .
As shown in FIG. 9 , the water supply and return taps can be arranged in a simple repeating pattern (e.g., no more than two or three different distances). For example, the distance between adjacent taps 54 can alternate between first distance 51 and second distance S 2 . The average distance (S 1 +S 2 )/2 can be two to ten feet. For example, the first distance 51 can be four feet, and the second distance be six feet. The distances 51 and S 2 can be a simple ratio, e.g., S 1 =(N/M)*S 2 where N and M are both less than 5. N/M can be less than 3. This permits tap spacing to be coordinated with raised floor tile/stanchion pitch (2 ft in US) while accommodating module 100 spacings that are not integer multiples of 2 ft.
As shown in FIG. 10 , as a more general case, rather than having the power taps 34 and water taps 54 / 64 have the same spacing, the distances D 1 and D 2 can be a ratio of small integers, e.g., D 1 =(N/M)*D 2 where N and M are both less than 5. Similarly, the distances D 4 between adjacent data taps can be a simple ratio of the distances D 1 or D 2 and D 3 . Having the distances be a ratio of small integers can simplify planning of data center layout. However, other ratios are possible. The power taps can be more closely spaced than the water taps 54 / 64 .
The spacing of the coolant taps 54 / 64 (and number of spigots per tap) can be selected such that when a full complement of modules 100 has been installed and connected to an associated cooling line, substantially all, e.g., more than 90%, of the coolant taps on the line are used.
In general, since power taps are less costly than coolant taps, and because power taps may be needed for other purposes, the data center can be installed with more power taps than would otherwise be required by the modules. This also permits greater flexibility in electrical connection to the modules 100 . The spacing of the power taps 34 (and number of receptacles per tap) can be selected such that when a full complement of modules 100 has been installed and connected to an associated power line, the modules use a plurality or majority but significantly less than all of the taps. For example, the modules can use more than 30%, e.g., more than 40%, e.g., more than 50%, of the power taps on the line. On the other hand, the modules can use less than 90%, e.g., less than 80%, e.g., less than 70%, of the power taps on the line. In one implementation, the modules use about 50% of the power taps on the line.
In addition, each pair of adjacent busbars or manifolds need not have the same spacing, but can be arranged in a simple repeating pattern (e.g., no more than two or three different distances). For example, the spacing between busbars can be closer for two busbars over modules that are disposed back-to-back (e.g., as shown in FIG. 5 ) than for two busbars over modules that are disposed across an aisle.
In general, the density of power taps 34 , water taps 54 / 64 and data taps 74 can be such that no hose or cabling need be longer than about ten feet to connect the components of a module to the nearest taps. The density of power taps 34 , water taps 54 / 64 and data taps 74 can each be substantially uniform across the area of the facility to be used for the modules (non-uniformity is more likely to arise along the walls of the building). Assuming that the ratio of water supply manifolds to power supply busbars is greater than 1:1, then each power supply busbar 32 can have a limited number of associated water supply and return manifolds (e.g., four or less each) that serve the same group of modules. Similarly, assuming that the ratio water supply manifolds to power supply busbars is less than 1:1, then each pair of water supply and return manifolds can have a limited number of associated power supply busbars 32 (e.g., four or less each) that serve the same group of modules.
FIG. 11 is a plan view of another implementation of a facility with cooling and power grids operating as a data center. As shown, the lines of power taps 34 and water taps 54 / 64 can be arranged perpendicular to the rows 102 of modules 100 . For example, the coolant supply manifolds 52 and coolant return manifolds 62 can extend under the raised flooring perpendicular to the rows 102 of modules 100 with taps 54 and 64 placed in the aisles 104 between the rows 102 . The busbars 32 can run perpendicular to the rows 102 , with taps 34 over the modules 100 . In general, in this implementation, the spacing of the taps along the lines can be about equal to the pitch between the rows of modules, and the pitch of the lines of taps can be about equal to the spacing of modules within a row. However, the various modifications to tap layout described above with respect to FIGS. 4-10 , e.g., modifications to pitch, spacing, staggering of the taps and lines, etc., can also be applied to the perpendicular arrangement. For example, coolant taps can be located every other aisle and service the modules on both sides of the aisle, or the supply and return taps for a given module can be located in aisles on opposite sides of a module.
A potential advantage to running the lines perpendicular to the row of modules is distribution of cooling and power load across different applications. Assuming that the rack-mounted computers in a given row 102 of modules 100 have similar applications, but that different rows of modules have different applications, then the perpendicular arrangement allows rack-mounted computers for different applications to be cooled by a common cooling plant. This can create an averaging effect on the cooling plant loads, so that spikes in activity for particular applications can be less likely to overwhelm the cooling capacity of a particular cooling plant. Similarly, the perpendicular arrangement allows rack-mounted computers for different applications to be powered by a common power supply. This can create an averaging effect on the power loads, so that spikes in activity for particular applications can be less likely to overwhelm the power capacity of a particular upstream piece of power distribution infrastructure, e.g., the capacity of a particular power distribution unit (PDU). This averaging effect and reduction in the spikes, can allow the deployment of an increased number of servers while still maintaining the appropriate equipment safety margins.
Although FIG. 11 illustrates both the lines of power taps 34 and water taps 54 / 64 arranged perpendicular to the rows 102 of modules 100 , in other implementations only the lines 21 of power taps 34 (see FIG. 12 ) or only the lines 52 / 62 of water taps 54 / 64 (see FIG. 12 ) are arranged perpendicular to the rows 102 of modules 100 . In particular, in one implementation, the lines 32 of power taps 34 are perpendicular to the rows 102 of modules and the lines of water taps 54 / 64 are parallel to the rows 102 of modules 100 . It can be more advantageous to provision the power perpendicularly than the cooling because insufficient cooling is a soft failure (a slight to modest increase in temperature) while for power provisioning, the failure mode is the tripping of a breaker or burning of a fuse. Thus, in the case of the failure of a line of power taps that is arranged perpendicular to the row of modules, the failure can be spread across multiple applications. As a result, for service provisioning, it is more likely that service for each application will be slightly impacted rather than having a catastrophic failure of service for one particular application.
Assuming that the rack-mounted computers in a row of modules has similar functionality, e.g., the rack-mounted computers function as search request servers, then the data lines can run parallel to the rows 102 . However, this is not required, i.e., the data lines could also run perpendicular to the rows 102 of modules.
In general, any portion of the power, cooling or data grids could be supported from either the floor or ceiling. The raised floor 14 (and associated plenum 22 ) could be absent, and portions of grids described as running through the plenum could simply run along floor. Similarly, the suspended ceiling could be absent, and portions of grid described as in the suspended ceiling could be supported by or from the ceiling 16 . There can be additional pumps or flow control devices; for example, there can be a pump for each manifold, or a pump at each tap. The power busbar 32 , manifolds 52 / 62 and data cabling 72 are shown as linear, but could include turns; the path of the data cabling 72 and manifolds 52 / 62 can be substantially similar to the path of the busbar 32 (e.g., if the busbar includes a right-turn, the manifolds 52 / 62 will also include a right-turn, although the location of the turn relative to the busbar could be offset to maintain spacing for the module or provide uniform spacing between busbar and manifolds (as in the embodiment of FIG. 4 )). A coolant other than water could be used.
There are several potential advantages of the facility 10 . Since a computer module can be moved into place and then connected to nearby taps with flexible hoses, power cables and data cables, installation of the computer module is very simple and can be accomplished by the personnel of the operator of the data center without further need for contractors (specifically plumbing or electrical contractors). In addition, once a computer module is connected, it can begin operation essentially immediately. Thus, the data center can begin operating even if only part of the available space is used. Furthermore, in the event of maintenance or malfunction, the system of parallel power busbars and cooling manifolds enables the rack-mounted computers attached to one power and cooling line to be taken off-line while rack-mounted computers in other portions of the data center continue functioning.
A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims. | A facility is described that includes one or more enclosures defining an interior space, a plurality of power taps, a plurality of coolant supply taps, and a plurality of coolant return taps. A flow capacity of the supply taps and a flow capacity of the return taps can be approximately equal over a local area of the interior space. The plurality of power taps, the plurality of supply taps, and the plurality of return taps can be divided into a plurality of zones, with taps of each zone are configured to be controllably coupled to a power source or a coolant source independently of the taps of other zones. The taps can be positioned along paths, and paths of the power taps can be spaced from associated proximate paths of supply and return taps by a substantially uniform distance along a substantial length of the first path. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to new and useful improvements in board game apparatus, and, more particularly, to board games utilizing to the maximum elements of skill and chance.
2. Brief Description of the Prior Art
Board games have been known for many years in which playing pieces are moved along a path of playing spaces to reach a given destination in accordance with chance moves. The game of Pachisi is a game of that type having its origins in antiquity. There are board games of various types that have been known from the middle ages or earlier to the present time. In this century, numerous board games have been developed having various objectives for the moves of the pieces.
Darrow U.S. Pat. No. 2,026,082 discloses one of the most popular board games in the United States, viz. the game called Monopoly. In this game, real estate is sold, purchased, developed and rented in accordance with the rules of the game and a movement of the various playing pieces.
Strehlow, U.S. Pat. No. 2,666,644 discloses a board game involving the movement of playing pieces around the path and utilizing transactions and stock or other securities markets as the premise on which the game is based.
Copending U.S. Pat. No. 2,976,044 discloses a board game involving transactions in property.
Breslow U.S. Pat. No. 3,679,210 discloses a board game involving movement of pieces around a playing path and involving transactions in works of art.
Henley U.S. Pat. No. 3,807,739 discloses a board game involving movement of pieces around a playing board and involving financial transactions of various types.
Magiera U.S Pat. No. 4,032,154 discloses a board game involving movement of playing pieces around a path of progression on a board and simulating the activities of a mail order business.
The prior art as exemplified by the above-noted patents, discloses a variety of interesting board games, but each of these games requires a maximum element of luck and does not involve skillful utilization of playing position or playing cards against the other players.
SUMMARY OF THE INVENTION
One of the objects of this invention is to provide a novel board game apparatus.
Another object of this invention is to provide an improved board game apparatus utilizing maximum elements of skill and chance in the course of the play.
Another object is to provide a new and improved game board apparatus which involves a simulation of casino or gambling house activities in movement of playing pieces around a board.
Another object of this invention is to provide a new and improved game board apparatus involving a substantial level of skill and finesse in the play of card holdings of one player against another.
Other objects of this invention will become apparent from time to time throughout the specification and claims as hereinafter related.
The above-mentioned objectives are attained in this board game apparatus, which comprises a board having marked spaces or areas constituting a path of progression around the board. The apparatus includes token money as a medium or indicia of payment. Movement of playing pieces is by chance, viz. a spinner indicating spaces to be moved. Spaces or areas on the board provide further instructions for further movement or for the mode of exchange of token money between or among the players or between the players and the house. Cards are provided having selected values and are used by the players to challenge and to play competitively with each other. Strategy of play depends upon position on the board and the cards available to the player to challenge other players. Payments from one player to another may result in winning or losing a challenge situation or by chance as dictated by the indicia on the players' position on the board. The board is also provided with structural features for varying the amount of payment due from a player to the house or from one player to another according to the desires of the players. The game involves a combination of chance or luck and skill in managing the cards drawn and the position occupied on the board.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B of the drawings disclose the right half and left half, respectively, of the playing board for a preferred embodiment of the board game comprising this invention.
FIG. 2 is a plan view of a spinner for indicating chance moves of playing pieces.
FIG. 3 is a side view or an elevation of the spinner shown in FIG. 2.
FIG. 4 is an isometric view of the support for the spinner shown in FIGS. 2 and 3.
FIG. 5 is an isometric view of the pointer for the spinner shown in FIGS. 2 and 3.
FIG. 6 is a view of two of the playing pieces or gamies.
FIG. 7 is a plan view of two representative value chips used in recesses on the playing board.
FIG. 8 is a plan view of two larger special value chips used at certain selected positions on the playing board.
FIG. 9 is a plan view of two of the ordinary playing chips.
FIG. 10 is a plan view of a loan or credit chip.
FIGS. 11A and 11B are opposite sides of a marker or IOU document used in the game.
FIG. 12 is a plan view of a player evaluation chart.
FIG. 13 is a plan view of two representative player number cards.
FIG. 14 is a view of one side of a card entitled, "KOOL OFF LOSE TURN".
FIGS. 15A and 15B are opposite sides of a credit note issued to players in the game.
FIG. 16A is the cover or back of playing cards called FINESSE CARDS used in the game.
FIG. 16B is the reverse side of a FINESSE CARD having a playing hand.
FIG. 16C is the reverse side of a FINESSE CARD called a KILLER CARD.
FIG. 16D is the reverse side of a FINESSE CARD called a BUST CARD.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, and, more particularly, to FIGS. 1A and 1B, there is shown a playing board 200 for a board game entitled, FORTUNE FINESSE. The playing board 200 has a plurality of marked playing spaces numbered 1 to 139 and individually labeled with playing instructions. The individual playing spaces will be referred to where necessary by either the space number of the indicia or identification of the playing space.
Playing board 200 is a folding board of substantial thickness and is provided with recesses 201 and 202 in the surface of the board.
Game board 200 is provided with a spinner 203 having a center aperture or hub portion 204 and having a radially extending flanges 205 dividing the surface of the spinner into discreet indicia marked areas. A support 206 is provided for spinner 203 and has a circular boss 207 extending from the underside thereof, and a supporting pin or axle 208 extending from the upper side. Boss 207 is of a size designed to fit snuggly into recess 201 on the surface of playing board 200. Supporting pin or axle 208 is of a size to fit smoothly in hub or aperture 204 for spinner 203 and allows for free rotary movement of spinner 203 thereon. The spinner is provided with a cooperating pointer member 209 having a main support 210 a pointer 211 and a cylindrical boss 212 extending from the base thereof. Boss 212 is of a size and shape to fit snuggly in recess 202 on playing board 200. When pointer member 209 is supported in position, pointer 211 extends over the surface of spinner member 203 and interferes with the free rotation of the spinner. Pointer 211 is quite flexible so that spinner 203 may be spun and pointer 211 will gradually slow down the rotation of the spinner and, finally, indicate the point at which the spinner has stopped.
The moving pieces used by the players in the game are the gamies 213 shown in FIG. 6. The gamies are provided in a plurality of different colors and are in a number sufficient to accomodate up to ten or more players. Players are also provided with player number cards 214, shown in FIG. 13, which are of the same size and shape, with each card having a different number and a different color. These cards are assigned to the players on a random basis as will be described in connection with the description of play. Each of the playing spaces is provided with a recess 215 which is of a size to receive disc-shaped chips having indicia indicating values to be assigned to each playing space. Spaces 1, 19, and 32 have special significance in the game and have slightly enlarged recesses 216. The other playing spaces having these recesses have the smaller recesses 215. The game is provided with a plurality of board value chips 217, shown in FIG. 7. These chips are, preferably 1/2" O.D.×1/16" thick and made of plastic. The chips have different values on opposite sides. There are nine different chips having the following indicia on opposite sides (1) 5¢-60¢ (2) 10¢-70¢ (3) 15¢-75¢ (4) 20¢-80¢ (5) 25¢-90¢ (6) 30¢-$1.00 (7) 40¢-$2.00 (8) 50¢-$5.00 (9) 50¢-$1.00 on one side and $1.00-$2.00 on the other side. These gray plastic tokens fit the recesses 215 and are placed around the playing board in a selected manner as set forth in the game description or as modified by the desires of the players. Special value tokens or chips 218 are shown in FIG. 8. These chips are slightly larger in size, e.g. 5/8" O.D. and are designed to fit the recesses 216 in playing spaces 1, 19, 32 and 139. The special value chips 218 are of gray plastic and of a size 5/8" inch O. .×1/16" thick. There are three sets of the chips 218 having different values on opposite sides, viz. (1) 25¢-$1.00 (2) 50¢-$2.00 (3) 75¢-$5.00. The players are also provided with somewhat larger playing chips which are 1/8"×11/8" O.D. of red plastic. There are eight different chips in the denominations 5¢, 10¢, 25¢, 50¢, $1.00, $5.00, $10.00 and $20.00. These chips, numbered 219, are shown in FIG. 9. In addition, there is still another type of playing chip, the credit chip or loan chip 220, shown in FIG. 10. This is a chip of distinctive color, bearing indicia on its face of a certain amount, e.g. $5.00 (credit chip). The chip is preferably 1/8"×11/2 O.D. This chip is oversized and distinctive in color and bears the credit indicia so that it can be easily distinguished in play.
There are several types of cards used in the play of the game. There are individual slips or markers 221, shown in FIGS. 11A and 11B (which are opposite sides of the same slip) which are used for handling loan transactions in the course of the game. In FIG. 14, there is shown a card 222 marked KOOL OFF LOSE TURN. The use of this card will be described later. In FIGS. 15A and 15B, there are shown opposite sides of a credit note card 223 which is used in credit transactions and will be described more fully hereinafter. In FIG. 16A, there is shown the back of the FINESSE PLAYING CARDS 224. Certain of the cards 224 bear playing hand indicia 225 which indicate different poker hands. These cards are called "FINESSE CARDS". Certain of the cards 224 have the death's head indicia 226 thereon and are called "KILLER CARDS". Still others of the cards 224 bear the indicia "YOU BUST" 227 thereon. These are called "BUST" cards. The manner of use of the FINESSE cards, the KILLER cards and BUST cards will be described more fully in connection with the description of play of the game. Finally, there an evaluation 228, shown in FIG. 12 which is used in player evaluation at the end of the game.
Before describing the sequence of play in detail, it is necessary to understand the terminology used in this game and also the rules of the game. Consequently, this explanation begins with a series of definitions and a set of rules of the game and is addressed to the reader as an individual who is learning to play the game.
VOCABULARY AND DOCUMENT DEFINITIONS
Alphabetically Ordered
Aces
One space on the Spinning Wheel 203 marked 1 or 11. Before one crosses the Margin Line, and Ace will count as 1. After crossing the Margin Line, Aces will count 1 or 11. This means one can move 1 or 11 spaces. Also, the Ace will be used in Black Jack and Long Shot as 1 or 11.
Ante
Each player will pay the full value of the Ante to the Ante Tray before they will be allowed to spin again and move forward. Each player must spin any number 1 to 10 to move their Gamie 213 off Ante for their official play of the game to start. It is possible a player could be Scratched and moved back to Ante. If this happens, he will not have to Re-Ante, but will have to spin a 1 to 10 to start his play again.
Ante Tray
The container where every player pays the Ante Value.
Arrows
1. The Big Arrows are on all the Strips. They direct each player how to move their Gamie 213 from the Start to the Finish.
2. The Small Arrows are pointed from the Document Spaces showing their Values.
Black Jack
1. When a player occupies this Space, he will try to spin 21 in two spins of the Wheel 203. This is Black Jack, and the player will win the Highest Value of the Space from all players.
2. When a player spins the Wheel five times without busting 21, he will win the Lowest Value of the Space from all players.
3. When a player spins over 21, he busts, and may pay the Kitty the Lowest Value of the Space.
Bust Card
There are six Bust Cards 227 in the Finesse Cards. Refer to Rule 3, below.
Cashier of the House
The Judge and Coordinator of the game. Refer to Rule 1, Below.
Challenge
One player competing against the other players, using his Finesse Card 225 against the other players' cards to win money.
Challenge Table
Challenger to play one Finesse Card 225 against all the opponent players' cards that are occupying a Value Space. The Challenger cannot tie or lose to one player or he loses the Challenge. While the Wheel is spinning the Challenger must speak outloud for all to hear: "I Challenge the Table."
Challenge Table Use Finesse Card--Win or Lose Document
When a player occupies this Document Space, he must Challenge the Table. He must defeat all the players of The Table that are occupying a Value Space. If only one player of The Table ties or has a better Finesse Card, then the Challenger will have to pay all the players and Kitty the same per player the Value of the Space he occupies. If the player that had to Challenge has the winning Finesse Card, he will collect Double from each player their Value Space. If none of the opponents occupy a Value Space, the play is dead. There is only one of these Documents in the game, and it is located on the Royal Strip, (Space #110). A Document Challenge will over rule a Vocal Challenge. The Vocal Challenge will be off.
Collect Or Win Spaces
If the Document does not determine the number of players to collect from, then one will collect from all the players.
Collect or Win (Spin) Spaces
If the Document does not determine the number of players to collect from, then one will collect from all the players.
Cool Off Lose Turn
The player that lands on this Document will lose his next turn. If a player is Scratched on this Document he will move back ten spaces and will not be liable for the play or what the Document reads, but he will be able to play his next turn. The player that takes over his Space will lose his next turn. Anytime a player occupies this Document, the Cashier will issue him a (KOOL) OFF LOSE TURN CARD, 222.
Credit Chips
When a player needs to borrow money, they will be issued these Chips 220 by the Cashier. The Cashier will be able to keep track of the money loaned out by the number of Chips 220 given to each player. Refer to Rule 10, below.
Credit Note
A Note 223 given to a player when he is loaned money by the Cashier. On the back of this Note, 223, is a Chart detailing Interest Rates to be paid back before and after game, and which also has the amounts player can be loaned. Refer to Rule 10, below.
Daily Double
This document has two Value Spaces, therefore, it pays Double.
Detour Space
Anytime a player occupies the Detour Space, he must detour. A player can choose which Strip he wants to play, as long as he does not land on Detour.
Documents
The readings of all the Play Spaces on the Board Strips that determine what each of the players are to do.
Evaluation Chart
Quotes exactly how good a player is by the amount of money he wins. If a player owes the House money after the game is over, and does not pay the money back, he will be rated as a Poor Risk for next game. Cashier is responsible for reading the Chart after game is over.
Finesse
Clever execution, witty play, intelligent and smart tactics.
Finesse Cards
The Cards 225 used to Challenge.
Fortune
Total amount of money won. The Pot of Gold under the Rainbow.
Game Chips
The colorful Chips 219 used for money.
Gamie
The given name of the Objects 213 the players use to move from one space to another.
High/Low
When a player occupies this Space, he will have a chance to spin the Wheel one time. While Wheel 203 is spinning, the player will speak out loud "High" or "Low".
1. If a player declares "High" and the Wheel stops on 8, 9, or 10, he will win the Value of the Space from all the players.
2. If a player declares "Low" and the Wheel stops on 1, 2 or 3, he will win the Value of the Space from all the players.
3. If the Wheel lands on 4, 5, 6, or 7, the player will pay the Kitty the full Value of the Space.
Joker
The Clown on the Spinning Wheel 203. The joker is not wild. If a Joker is spun on the Spinning Wheel, after a player is off the Start, that player will draw one Finesse Card 224 and stay on the Space he occupies. Refer to Rule 8.
Joker Take Card
Anytime one occupies one of these Sapces, he will be entitled to draw one Finesse Card 224.
Killer Card
The Finesse Card with the Skeleton Head and Crossbones, 226.
Kitty
The penalty money
Ladies Luck
If the Ladies land on this Document Space, they will win the Value of the Space from all Gents.
Liable
A term that makes all the players responsible for their Documents, Spins, Challenges and Plays.
Long Shot
When a player occupies this Document Space, he will have a chance to spin the Wheel three times. If the player spins the Total number of 20 by adding all the spins together, he will win the amount the Document reads. If not, he wins nothing. A player cannot be Scratched on this Space. More than one Player can occupy this Space Aces count 1 or 11, King counts 10, Queen counts 10, Jack counts 10, and all the other Numbers their amount. Joker counts as a spin only.
Lucky Gents
If the Gents land on this Space, they will win the Value of this Space from all Ladies.
Margin Line
The Line between the 10th and 11th Spaces at the beginning of the game. All players must cross this Line before they can be Scratched, Busted, Challenge or be Challenged, play the Royal Court, spin his own Number or 11 to count 11 on the Spinning Wheel.
Markers
These are the I.O.U. Pads 221. Refer to Rule 10, below.
Occupied Document
At no time can two players occupy the same Document Except: Start, Ante, Triple Crown, Long Shot, Stop and Staircase.
Playing Partners
All players will play as if they are playing by themselves. At the end of the game, the partners will add their winnings together.
Player Numbers (Pointer Cards)
The Player Numbers 1 to 10 are printed on these Cards 214. Each player will own one number before the game starts. There are five Odd Numbers: 1, 3, 5, 7, 9 and five Even Numbers: 2, 4, 6, 8, 10. These Numbers are also on the Playing Board Refer to Rule 2, below.
Re-Ante (After Finish)
After the first player crosses the Finish, all the other players can voluntarily Re-Ante the present Value of the Ante. Each time a player crosses the Finish, this can be repeated. Each time a player crosses the Finish, he will win the amount of Chips in the Ante and the Kitty.
Royal Court
Consists of three Faces: King, Queen and Jack, on the Spinning Wheel. A Royal Court play is not in effect until a player crosses the Margin Line. Refer to Rule 7, below.
Royal Flush
There are four Royal Flushes in the Finesse Cards 225. A Royal Flush is: Ace, King, Queen, Jack and 10, all of one suit in sequence. This is the Highest hand in the game. Refer to Rule 6.
Safe Pass
This Space has no value. A player cannot be Scratched, Busted, or Challenged while occupying this Space. If a player draws a Bust Card, he will return it to the Cashier to be reshuffled and draw another Finesse Card 224.
Scratched
When one player moves forward to a Space which is already occupied the player that occupied this Space, will be penalized to move backwards 10 spaces. All players must be over the Margin Line before they can be Scratched. Refer to Rule 9, below.
7 Come 11
When a player occupies this Space, he will spin the wheel one time. If the player spins a 7 or 11 he will win the Value of the Space from all players.
Show Down
The last time every player can use their Finesse Cards 224, against each other after crossing the Finish Refer to Rule 12.
Slide
Slide does not count as a Space for moving Gamie 213.
Spinning Wheel
The Wheel 203 in the center of the Playing Board 200 that each player spins when it is their turn. The Wheel is composed of 14 separate sections in a clockwise order: 1 or 11 Aces, 2, 3, Jack, 4, 5, Queen, 6, 7, King, 8, 9, Joker and 10. Everything on this Wheel will determine how you will play the game.
Staircase
When a player reaches this point, he is ready to Finish the game. If he has an Odd or Even Player Number, he will have to spin the Wheel on his turn to determine if he can move a Step closer to the Finish. The first player to the Finish will win the money in the Kitty and the Ante. If a player has an Even Player Number, he must spin an Even Number on the Spinning Wheel in order to move one Step on the Staircase. Same goes for Odd Player Numbers. The Joker, Jack, Queen and King will count as spins if spun on the Spinning Wheel. They have no value for moving Gamie. If a Joker is spun while occupying the Staircase, that player will draw one Finesse Card. All players can be Challenged or they can Challenge while occupying the Staircase, because each Step has a Value. All players can be Busted on these Steps.
Standard Numbers
The Standard Numbers are the small numbers printed on each Value Space on the Playing Board from the Start to the Finish numbered in sequence 1 thru 139. These Numbers will guide the players in setting up the Playing Board Value Spaces in sequence to the Standard Playing Board Value Chart.
Stop
The last Space on the Playing Board that all the players will Stop at before proceeding down the Staircase. No matter what number is spun, the player will Stop on this Space. This Space has no Value; one cannot Challenge, be Challenged, or Scratched on this Space. One can Bust on this Space.
Strips
All the Documents added together to form six sections on the Playing Board. These sections are called Strips. There are six strips called: Copper, Nickel, Silver, Diamond, Golden and Royal.
"Sweat" Use Finesse Card
Anytime a player occupies this Document Space he must use one Finesse Card 224 against all the opponent players. All the players occupying a Value Space will have to use one Finesse Card. The player that has to play against all the other players can win from one, two or three players, or lose to one. Either way, he will pay only to the players he loses to, plus pay the Kitty the same per player, or collect from the players he beats in the same play. If there are no players occupying a Value Space, the player that had to play against all the other players will pay the Kitty the Value of the Space he occupies, then play is over. This Document Play will over rule a vocal Challenge. The vocal Challenge will be off.
The Table
All the players involved in the game.
Token Pick
A solid piece of plastic used to remove the Value Chips from the Value Spaces on the Playing Board.
Triple Crown
The players occupying this Space will immediately do what the Document reads. A player can be Challenged while he occupies this Space. A player cannot be Scratched on this Space. More than one player can occupy this Space.
Value Chips
These chips 217 are all the same color gray and can be interchanged in and out of the Playing Board Value Spaces to change the Value of the game from Low to High.
Value Spaces
These are the counter sunk holes 215 on the Playing Board above the Documents, where the Value Chips are placed.
The Rules of the Game are set forth as follows:
RULES OF THE GAME
Rule 1: Cashier of the House
Before the game can start:
The first procedure will be to appoint the Cashier of the House. This will be accomplished by the player placing all the Pointer Player Number Cards (214) 1 through 10 face down on the Playing Board, shuffled. Each player will draw one Player Number and this will be his Number and Title through the entire game. The player that draws the Highest Player Number 214 will be appointed the Cashier of the House. He may relinquish this Title to the next player with the Highest Player Number if desired.
The Cashier's job is to be the Judge and Coordinator of the game, controlling the play of the game according to the rules. He has the right to dismiss any player of the game with just cause. The Cashier will issue at this time only: Gamies 213, Finesse Cards 224, and Chips 219. He will be responsible for issuing the correct amount of Playing Chips 219 in accordance to the number of players in the game. Refer to How To Play Game Step By Step, 7th Paragraph for this information. The Cashier will be responsible for controlling the Playing Chips 219, Credit Notes 223, Credit Chips 220, Markers 221, Kool Off Lose Turn Cards 222, and all loaning and collecting procedures with Interest before or after the game is over. The Cashier will receive that amount of Interest on the back of the Credit Note Cards 223, the Markers 221 and also 10% of the original Kitty, only after the game is finished.
The Cashier will start the game off by spinning the wheel first and seeing that all the players spin the wheel in a clockwise order on their turn. He will see that all the players spin the wheel correctly. The wheel must rotate at least five revolutions to be a correct spin, or that player will have to spin over. He will be responsible to see that all the players pay the Ante and the Kitty, abide by all the Document Readings, make their Challenges clear and correct and use their Finesse Cards according to the rules. The Cashier will always collect the amount of the Ante from any player that fails to draw or exposes a Finesse Card 224. The Cashier has a big job and may depend on the other players for help. The Cashier will not settle up on the Ante or Kitty until the game is completely over so as to keep from interfering with the other player' play of the game.
After the game is over, the Cashier will read the Evaluation Chart 228 describing each players' Game Status and Ranking.
Rule 2: Players Numbers
There are 10 separate numbers printed on individual Pointer Cards, 1 through 10, consisting of 5 Odd Numbers, 1, 3, 5, 7, 9 and 5 Even Numbers 2, 4, 6, 8, 10. These Numbers (214) will be shuffled and placed on the Playing Board face down. Each player will draw one Number and that Number will determine if a player is Odd or Even. Once a player has established this Title of being Odd or Even, it will be his for the entire game. Each players' Number must be placed in front of him at all times, with the Number facing up, pointing toward the Playing Board visible for all the players to observe. All these Numbers are very important as will become apparent while playing the game.
A player may Challenge the opponent players by simply speaking out loud the Players' Numbers. Refer to Rule 5 for "How to Challenge" procedure.
The Highest Player Number drawn will be appointed the Cashier of the House and he will spin the Spinning Wheel first to start the play of the game. After the Cashier has issued all the game Pieces, and all the players' Gamies 213 are on Start, each player will have their chance to spin an Odd or Even Number on the Spinning Wheel 203. If you own an Odd Title, you must spin an Odd Number on the Spinning Wheel 203 to be eligible to advance to the Ante. Same procedure for Even Title. Each player will have three different turns to spin the Wheel, trying to advance from the Start to the Ante. If a player fails to spin an Odd or Even Number, one of which pertains to his own Title, on his third turn, that player will automatically advance to Ante, pay Ante and immediately spin again to start his play of the game. Once a player is off the Start, he will follow the rules of the game and will be able to spin and move his Gamie 213 on any number spun on the Spinning Wheel. The only other time a player will have to worry about his Odd or Even Title is when he tries to move his Gamie Step by Step on the Staircase to the Finish. If a player has an Even Title, he will have to spin an Even Number in order to move his Gamie one step close to the Finish. Each player must move his Gamie on all three of the Steps of the Staircase in order to Finish. Same procedure is used for Odd Title.
There are six Strips on the Playing Board, and on these Strips there are 1 through 10 Player Numbers identical to the Number each player drew before the game started. Each player has one Player Number on the Playing Board Strips, and at no time can a player that is occupying his own Number be Scratched or Challenged.
1. If a player makes the mistake of Challenging a player that is presently occupying his own Player Number an the Strip, the player that Challenged will pay the owner of the Number the Highest value of the Space.
2. If a player occupies his own Number on the Strip, he can Challenge the opponent players if he desires.
3. Anytime a player occupies his own Number on the Strip, he will collect the Highest value of the Space from all the players in the game.
4. If a player is occupying his own Number on the Strip and an opponent player happens to land on this Number, the player that landed on the Number will pay the owner of the Number the Highest value of the Space, and then move back ten Spaces and play the Document he lands on.
5. Anytime a player lands on a Player Number on the Strips, he will pay the owner of that Number the Highest Value of the Space.
6. Anytime a player lands on a Player Number on any of the Strips and no one owns that Player Number, the player that landed on the Number will have to pay the Kitty the Lowest Value of the Space.
7. After a player crosses the Margin Line and spins his own Player Number on the Spinning Wheel, he will be entitled to collect from one player of his choice the Highest value of the Player Number Value Space on the Playing Board.
Rule 3: Finesse Cards
There are 100 Finesse Cards 224. These Cards are made up of different Poker Hands 225. Four Royal Flushes 225, 20 Killer Cards 226 and 76 other different types of Finesse Cards bearing symbols of various poker hands. The Finesse Cards, when produced on a Challenge, will determine the outcome of the play. Before the game starts, every player will receive from the Cashier one Finesse Card. After the game is started, it will be up to each player to draw his own Finesse Card. At anytime a player is caught without a Finesse Card, they will be penalized. The penalty for forgetting to draw a Finesse Card after your turn is over, is paying the present Value of the Ante to the Kitty, Cashier and to the player that will spin the Wheel next. Once the wheel stops, the penalty can be exercised by the Cashier. Any player can call this to the attention of the Cashier. As soon as the penalty is paid, that player will be entitled to draw a Finesse Card. After a Finesse Card has been used, it must be returned to the bottom of the original stack. If it was the only Finesse Card the player had at that time, he will draw another Card before the next player spins. If a player has more than one Card and uses one, he will not be entitled to another Card as long as he has one left in his hand. Anytime a player lands on a Joker Take Card Space, he will draw one Card. After a player is off the Start and that player spins the Joker on the Spinning Wheel, he will draw one Card. A player will not be penalized for forgetting to draw a Finesse Card on these two plays, for his penalty will be no Card. If a Finesse Card is exposed by mistake, etc., the player that owned that Card will pay all the players the Value of the Ante, plus return the Finesse Card to the bottom of the stack and immediately draw another Card, if it was the only Card he had at that time.
Bust Card
There are six Bust Cards 227 in the game. If a player is issued a Bust Card by the Cashier of the House before the game starts, that player will immediately turn the card face up on the Playing Board and at that time the Cashier will issue him another Finesse Card. At no time can the game be played until the Bust Card play is settled. All players must cross the Margin Line before a Bust Card will be in effect. If a player draws a Bust Card before he crosses the Margin Line, that player will turn the card over for all the players to view. The Cashier will return the card to the original stack and reshuffle the cards in the stack. Once a player crosses the Margin Line and draws a Bust Card, he will pay each player in the game the value of the Ante, and move backward to the first open Joker Take Card Space; this will entitle the player to draw another Finesse Card. If the first Joker Take Card Space is occupied, the player will continue backward until he lands on a Joker Take Card Space that is open. If a player has just crossed the Margin Line, and he draws a Bust Card, that player will move backward to the Joker Take Card Space. If the Joker Take Card Space is occupied, the player that Busted will continue backward to the Ante Space. He will not be required to Ante again, and is still entitled to draw another Finesse Card.
If a player draws a Bust Card and fails to show it immediately to the players in the game, he will be penalized by paying each player double the Ante, and then move backwards to the Joker Take Card Space that is open. All players must turn their Finesse Cards 224 over at the end of the game. If a player is caught with a Bust Card in his possession after the game is finished, that player will forfeit the Kitty and Ante. All players can be Busted while occupying the Staircase. A player cannot be Busted while occupying the Safe Pass Document. He will return the Bust Card to the Cashier to be reshuffled and draw another Finesse Card
Rule 4: Killer Card
These Finesse Cards 226 can be used to make a Challenge or to counter a Challenge. All Killer Cards 226 are equal, and when used against each other will nullify the play between the players involved. Two Killer Cards when produced will defeat a Royal Flush. This is the only time a player can produce another Finesse Card.
One Killer Card when used by a player on a Challenge or to counter a Challenge, will beat all 76 of the other Finesse Cards hands listed below:
Straight Flush
Full House
Straight
Two Pair
Four of a King
Flush
Three of a King
Killer Card Document Play
If a player occupies a Document which reads or entitled him to win money from the other players, and he chooses the players he wants to collect from, at that time the opponent player may produce a Killer Card to avoid paying him. This does not pertain to: Pay Kitty, Cashier, Ante, Craps, Players Numbers or Penalties. Once a player has chosen the players he wants to collect money from, he cannot retract his choice.
Rule 5: Object of Challenge
The purpose of making a Challenge would be to wait until the opponent players are on a large Value Space so the Challenger can play his Finesse Card to win more money. This is "FINESSE"
Challenge;
The only time a player can Challenge is when it is his turn to spin the wheel 203. The Challenger can Challenge the Table or any number of players he prefers, providing they occupy a Value Space. The Challenger will also have to occupy a Value Space after his play. The Challenger will not have to declare who he Challenges until the present play is played or Gamie is moved. Once a Challenge is made, it cannot be retracted. If one Challenges and moves to a Document that requires one to Challenge or Sweat Use Finesse Card, he will play the Document only and the vocal Challenge is off. A player must be across the Margin Line before he can Challenge or be Challenged.
How to Challenge: Step by Step
[A] One can Challenge only on his turn, after he crosses the Margin Line.
[B] Spin the Wheel. While wheel is spinning, one should speak out loud for all players to hear, "I Challenge" or "I Challenge the Table."
[C] After the wheel has stopped, you will execute the play the Spinning Wheel has determined first.
[D] The Challenger must occupy a Value Space after his present play for the Challenge to stand.
[E] The present play will determine if one stays or moves to a different space. Either way, the Challenge is good if you still occupy a Value Space.
[F] If present play places one on a space of no value, the Challenge is off.
[G] If one Challenges by accident and no opponent player occupies a Value Space, he will pay the Kitty the amount of the game Ante Value.
[H] If the present play is good for Challenge to stand, then one will declare which players (one, two or all players) he wants to Challenge.
[I] One will play one Finesse Card against the opponent players Finesse Cards. All players involved in the Challenge will place one Finesse Card face down on the Playing Board and all the players will turn their cards over at the same time. Once a Finesse Card has been exposed, it cannot be retracted.
[J] On a Challenge, all the players are against the Challenger. Their Finesse Cards are no good against each other. Their play is strictly to defeat the Challenger.
[K] The best Finesse Card wins the Challenge.
Example: Regular Challenge
If one Challenges, he could win from two players and lose to one player, depending on how many players he has Challenged.
Challenge Table
[A] As defined in the Vocabulary, the Challenger must defeat all the players occupying a Value Space. If he ties or loses to just one player, he loses the Table Challenge and will have to pay all the players his Value Space plus pay the Kitty the same per player.
[B] If the Challenger defeats all the players on a Table Challenge, he will collect from each player double their Value Space.
[C] If a Royal Flush Finesse Card is used on a Table Challenge by the Challenger he will win Triple from all players involved. Refer to Rule 6, below.
Rule 6: Royal Flush Challenge
If the Highest Finesse Card in the game is used on one particular play, it will be placed on the game board face down. At that time, all the players that were Challenged will do the same. All the players involved in the Challenge will turn their Finesse Cards over at the same time. The only time one player can produce one more Finesse Card to make a total of two in the Challenge play will be to defeat a Royal Flush Finesse Card. It takes Two Killer Cards to defeat a Royal Flush Card. At no time can the opponent players Finesse Cards be combined to defeat a Royal Flush Finesse Card. Whenever a player Wins a Challenge with a Royal Flush Finesse Card, he will Collect Double from each player involved in the Challenge, the Value of the Space they presently occupy. If a player that Challenges Loses with a Royal Flush Finesse Card, he will pay only to the players he loses to, the Value of the Space he now occupies and will also pay the Kitty the same per player, Not Double. Whenever a Royal Flush Finesse Card is used in a regular Challenge the Challenger will always Collect Double. A Royal Flush Finesse Card Cancels out another Royal Flush Finesse Card between the players involved.
Royal Flush Table Challenge Play
Whenever a Royal Flush Finesse Card is used on a Table Challenge by the Challenger and he wins the Challenge, he will Collect Three times the Value of the Space the losers presently occupy. If the Challenger loses to just one player on the Table Challenge, he will pay all the players the Value of the Space he occupies, plus pay the Kitty the same per player involved. The Challenger will not pay Triple to any opponent players on a Table Challenge. If there is a tie, the Challenger loses.
Rule 7: Royal Court
The Royal Court is Jack, Queen, and King on the Spinning Wheel. At no time will a player move their Gamie to another Space when one of these are spun on the Spinning Wheel. Before you can play the Royal Court, you must cross the Margin Line. If you spin a Jack, Queen, or King while occupying the Start, Ante or any of the other Documents before crossing the Margin Line, your play will be dead until your next turn.
The Royal Court: Jack, Queen and King each have a value of 10, only for playing Long Shot or Black Jack.
How to Play the Royal Court
The Jack always Collects Double
The Queen always Collects Triple
The King always Collects Quadruple
If one spins a Jack, Queen or King on the Spinning Wheel after crossing the Margin Line, he will receive Double, Triple, or Quadruple the value from the first Collect Space forward, not Win Space, but Collect Space from all the players or the number of players the Document reads.
It is easy to find the Collect Spaces, for all their Values are circled in Red.
Rule 8: Joker [On the Spinning Wheel]
The Joker is not wild. If a player is on Start and spins a Joker, it will count as one spin only. That player will not be entitled to draw a Finesse Card. If a Joker is spun on the Spinning Wheel after a player is off Start, that player will draw one Finesse Card and stay on the space he presently occupies. If playing Black Jack or Long Shot and a Joker is spun, it will count as one spin only. At no time, when a Joker is spun on the Spinning wheel will one move his Gamie.
Rule 9: Scratched
When a player moves his Gamie forward on his turn and lands on a Space that is already occupied by another player, the player occupying the Space will be penalized, (Scratched), and will have to move backwards ten spaces. The player who took over the Space that was already occupied, will then be liable to do what the Documents reads. Anytime a player is moved backwards, (Scratched), by another player, he will not have to play the Document, because it was not his play that moved him backwards. A player must have his Gamie over the Margin Line before he can Scratch another player. No player can be Scratched before crossing the Margin Line. If a player lands on a Space already occupied before the Margin Line, that player will move his Gamie forward to the first open space, and play the Document. If a player moves his Gamie one Space past the Margin Line and Scratches a player occupying this Space, that player Scratched will move backwards ten spaces; in case he lands on a Space already occupied, he will continue backwards to the first open Space and, if necessary, to the Ante. If this happens, the player that moved backwards will not have to Re-Ante. At no time will two players occupy the same Document except: Start, Ante, Triple Crown, Long Shot, Stop and the Staircase Steps, and at no time can a player be Scratched on these Documents. A player at no time can be Scratched on his own Player Number. If a player is occupying his own Player Number on the Playing Board, and and another player lands on this Space, that player will pay the owner of the Number the Highest Value of the Space. He will then move backwards ten Spaces and do what the Document reads, because he moved himself backwards. A player cannot be Scratched or Challenged whenever he is occupying the Safe Pass Document. If a player is occupying the Safe Pass Document and another player lands on this Document, the latter will be Scratched, (moved back ten spaces) and be liable to play the Document.
Anytime a Document on the Playing Board moves a player backwards, he will be liable for the Document he lands on. There are eight of these Documents in the game.
Rule 10: Credit Chips--Credit Notes--Markers--Kool Off Lose Turn Cards
CREDIT CHIPS:
The Cashier will issue a $5.00 Credit Chip 220 to a player when needed, only $20.00 worth of these Chips can be loaned per player. This will help him keep track of the amount of money. Each player will return his Credit Chips as he repays his loans plus interest.
CREDIT NOTES:
At the time a player borrows money and receives his first Credit Chip 220 the Cashier will issue him one Credit Note 223. The backside of the Credit Note describes the amounts of interest to be paid back before and after the game is over to the Cashier. If a player pays his loans, plus interest, that player will return his Credit Note Card and his Credit Chips back to the Cashier, to show that his loan has been paid off.
MARKERS:
If a player has borrowed his limit in Credit Chips 220 and needs more money, the Cashier will issue him a Marker 221. A player may loan another player money if they both agree to do so. All signatures will be required from all the parties involved. The Markers 221 have the amounts that may be loaned and the percentage of interest to be repayed listed on the back.
KOOL OFF LOSE TURN CARDS:
There are six of these Cards 222 in the game. If a player occupies one of the Kool Off Lose Turn Spaces on the Playing Board, the Cashier will issue that player one of these Cards to be turned face up in front of the player, for all the players to view. This Card is to remind a player and all players that he loses his next turn to spin the Wheel. On that player's next turn, he will at that time, give the Kool Off Lose Turn Card 222 back to the Cashier. If he fails to return the Card to the Cashier, he will lose his following turn. He, alone, is responsible for returning his card.
Rule 11: Staircase and Finish
All the players of the game will Stop on the last Document on the Playing Board, which is the Stop Document, and there he will wait until his next turn to spin the Spinning Wheel. When a player reaches this point of the game, he is ready to proceed Step by Step on the Staircase to the Finish.
If a player has an Even Player Number, he must spin an Even Number on the Spinning Wheel in order to move his Gamie one Step on the Staircase. Same goes for Odd Players Numbers. This will be repeated by all the players on their turns until all of the players have completed moving their Gamies on each of the three Steps on the Staircase to the Finish. All players can Challenge or be Challenged on the Staircase Steps, because each Step has a value.
The first player to cross the Finish will win 90% of the money in the Kitty and all of the money in the Ante. At this time, the player that finishes first will take possession of the Kitty and Ante, and then wait until the rest of the players have finished the game. This will keep from interfering with the rest of the players still playing the game. As soon as the first player crosses the Finish, and collects the Kitty and Ante, at that time, the rest of the players in the game may Re-Ante and then continue on with the game. This procedure can be repeated until the last player crosses the Finish. If agreed among the players, the game can end after the first player crosses the Finish.
Anytime a player spins a Joker, Jack, Queen or King on the Spinning Wheel, it will count as a turn spin only. Player will never move his Gamie if any of these are spun on the Wheel. If a Joker is spun, that player will be entitled to draw one Finesse Card.
REMEMBER: The Cashier only collects 10% of the Kitty from the first player that crosses the Finish.
After all the players have crossed the Finish, they can play "Show Down," if they desire. Refer to Rule 12, below.
Rule 12: How to Play Show Down
After all the players have crossed the Finish, they will have one last chance to win money, and this play is called, "Show Down." All players who desire to play will put up four times the present Ante Value. Each player will place one Finesse Card face down on the Playing Board, then at the same time, all the players will turn their Cards over. The player with the Highest Finesse Card will win "Show Down." All the rules of the game will apply to the Show Down play, with one exception: if a Royal Flush Finesse Card is used, you will not win Double, (only four times the Ante Value per player.) Now all the players in the game will turn their remaining Finesse Cards face up in front of them for all players to view. In case of ties, the Cashier will divide the Chips equally between the winners.
Now the game is officially over. The cashier will settle up the House, (Interest owed, etc.), and write down all the players' winnings or losses to determine who won "FORTUNE FINESSE." The Cashier will then read the Evaluation Chart, in accordance to the number of players in the game, and give each player their Status and Ranking.
On the playing board 200, there are small numbers printed on each Value Space on the playing board from the start to the finish. These are the "Standard Numbers" for the Value Spaces and range in sequence from 1 through 139. These numbers are used by the players in setting up the playing board Value Spaces in sequence according to the standard playing board Value Chart below.
______________________________________STANDARD PLAYING BOARD VALUE CHART______________________________________1. .50 Ante 48. .25 94. .402. .50 49. .75 95. .503. .25 50. .50 96. .50/$1.004. .20 51. .50 97. .50/$1.005. .50 52. .50 98. .256. .25 53. .50 99. .307. .20 54. .25 100. .758. .50 55. .90 101. .209. .30 56. .40 102. .2010. .10 57. .25 103. .5011. .25 58. .25 104. .5012. .50 59. .25 105. .9013. .30 60. .50 106. .3014. .20 61. .25 107. .2015. .50 62. .40 108. .2016. .50 63. .50/$1.00 109. .2517. .50 64. .25 110. .5018. .75 65. .25 111. $1.0019. $2.00 Triple Crown 66. .50 112 .5020. $2.00 67. .50 113. .7021. .25 68. .50 114. .2522. .25 69. .50 115. .3023. .50/$1.00 70. 1.00 116. .50/$1.0024. .75 71. .25 117. .5025. .50 72. .25 118. .2026. .30 73. .50/$1.00 119 $1.0027. .50 74. .50 120 .2528. .50/$1.00 75. .50 121. $1.0029. .20 76. .50 122. .2530. .50 77. .25 123. .3031. $1.00 78. .75 124. .5032. $2.00 Long Shot 79. .80 125. .6033. $1.00 80. .80 126. .50/$1.0034. .30 81. .25 127. .5035. .25 82. .50/$1.00 128. .2536. .50/$1.00 83. .50 129 .5037. .70 84. .40 130 .2038. .25 85. .60 131 .5039. .40 86. .50 132. .4040. .50 87. .80 133. .2041. .50/$1.00 88. .40 134. .2542. .50 89. .70 135. .4043. .25 90. .25 136. .7044. .30 91. .80 137. .5045. .50 92. .70 138. .2546. .90 93. .50 139. $1.0047. .50/$1.00______________________________________
Fortune Finesse is a Versatile Game many can play for Fun or Serious entertainment. Designed with equal balance, for all the players to Compete against each other to Win the most Fortune by using Finesse Tactics, on playing the Documents and Challenging from the Start to the Climactic Finish. A Game in which all the players can converse. Outloud with each other, while Competing, by pointing out the Mistakes and the Wealth of the other players.
To find a Fortune is Luck, but to have a chance to Win a Fortune is exciting and rewarding. The Game of Fortune Finesse will give a player this chance to show his knowledge and skill in active competition, just to see who is the smartest and best in using Finesse. From the Start to the End one will enjoy travelling around the colorful Playing Board while playing the Documents to his advantage. One will always use Finesse in choosing the players with the most Fortune to Collect from; never giving a player the opportunity to build his Wealth where he can Challenge at will, without a second thought or feeling pressure. One should be alert and use his Finesse Cards wisely at all times, sometimes, Challenging just to rid oneself of a Finesse Card so he can draw another one, or to Challenge the other players to keep them from accumulating too many Finesse Cards so they can protect their best Finesse Cards to use later, on their terms. For each player Finesse can pay off. One should be patient and try to accumulate as many Finesse Cards as possible; this will give good Finesse Card protection and will keep the other players from drawing the best Finesse Cards out of one's hand before he has had a chance to use them for his benefit. Always try to be prepared for being Challenged, surely be prepared with one's own best Finesse Card to make a Challenge on your terms when the opportunity exists. For example, one should wait until he sees the other players occupying a Space of High Value and on his turn this will be the time he will use Finesse and Challenge those players. If one plays his Cards right, he will come out on Top. Remember, while one is making his Fortune by playing the Documents and Challenging, the Kitty and Ante are growing into a Fortune. The first player that Finishes on the Staircase will be rewarded the Kitty and the Ante. Remember, the player that uses Finesse with the most Success will be the best in Fortune Finesse.
You are now ready to play the game following the Step-by-Step sequence of instructions given below:
HOW TO PLAY GAME STEP-BY-STEP
1. Read and understand the Rules
2. Understand the Vocabulary and the Document Definitions.
3. Place all ten Pointer Cards, which are the Player Numbers, face down on the Playing Board, after being shuffled.
4. Each player will draw one Player Number. Any players can play partners.
5. Highest Player Number drawn is appointed the "Cashier of the House."
6. Cashier will ask all the players if they want to play on the Standard Board Values or change the Values.
7. If Standard Board is used, the Cashier will issue:
(a) $10.00 worth of Chips to each player for 2-3 players in game.
(b) $15.00 worth of Chips for 4 players
(c) $20.00 worth of Chips for 5 players
(d) $25.00 worth of Chips for 6-10 players
(e) One Gamie to each player
(f) One Finesse Card to each player
8. When Gamies are all on Start, Cashier will spin first.
9. Each player will try to spin on Odd or Even Number on the Spinning Wheel on three different turns. If a Joker, Jack, Queen or King is spun, on any of these turns, they will count as one of the turns spun only. If a player fails to spin an Odd or Even Number, whichever one that pertains to him on his third turn, he will automatically to to Ante, pay Ante and immediately spin again to try to move his Gamie off of the Ante Space.
10. If a player has satisfied spinning an Odd or Even Number, depending on what type Number he owns, he will pay to the Ante Tray the Value of the Ante. At this time, the player will be entitled to move his Gamie to the Ante Space. Immediately, he will spin again, attempting to spin any number 1 to 10 on the Spinning Wheel. If the player spins a number 1 to 10, his official play of the game is started and entitles the player to move his Gamie off the Ante Space.
11. Anytime a player has to return to the Ante Space for any reason, that player will have to repeat the process of spinning any number 1 to 10 again. He will not have to pay the Ante unless directed to by the Document.
12. Now, each player will begin playing the Documents before the Margin Line.
13. After crossing the Margin Line, these plays will go into effect:
(a) Aces will count as 1 or 11.
(b) A player can spin his own Player Number and win money.
(c) A player may Challenge or be Challenged.
(d) A player will play the Royal Court
(e) Scratched or be Scratched or Busted
14. Now, all the players will follow the Big Arrows on the 6 Strips from the Start to the Finish.
The play is officially started, so Players "GOOD LUCK." One should use Finesse on Challenges and play his Documents and make a Fortune, do his best on the spins and travel around the colorful board. Each should be sure to refer to the Rules of the game and Vocabulary until he has learned the game.
A few final pointers about the game are set forth here to improve your understanding of the game. Remember, always use Finesse when making your Challenges and wait until the right time for the opponent players to occupy a large Value Space so that you can increase your Fortune.
Study the rules and vocabulary of the game and understand, particularly, the different types of Challenges. The Simple Challenge, the Table Challenge or the Royal Flush Table Challenge. the Document Play Challenge Spaces on the Playing Board, i.e., Spaces 110 and 127. Remember, anytime you win a Challenge, you will collect the Value of the Space the opponent occupies. Anytime you lose a Challenge, you will pay the Value of the Space you occupy plus you will pay the Kitty the same amount per player. If a Vocal Challenge is made by a player, or a playing board Document makes the player challenge the other players, and one of the opponent players is occupying his own Player Number on the playing board, the player who had to Challenge is the automatic loser. One cannot win a Vocal Challenge or a Document Challenge when the opposing player is occupying his own Player Number. One final point to remember is that when playing partners, one should play as if playing by oneself and at the end of the game, the partners will add up their total winnings.
While this invention has been described fully and completely with special emphasis upon a single preferred embodiment, it should be understood that within the scope of the appended claims, the invention may be practiced otherwise than is specifically described herein. | A board game apparatus is disclosed having a board with marked spaces or areas constituting a path of progression around the board. The apparatus includes token money as a medium or indicia of payment. Movement of playing pieces is by chance. Spaces or areas on the board provide instructions for further movement or the mode of exchange of tokens between or among the players. Cards are provided having selected values and are used by the players to challenge and to play competitively with each other. Strategy of play depends upon position on the board and the cards available to the players. Payments from one player to another may result from winning or losing a challenge situation or by chance as dictated by the indicia on a player's position on the board. The game involves a combination of chance or luck and skill in managing the cards drawn. | 0 |
[0001] This application is a continuation of U.S. application Ser. No. 10/688,173, filed on Oct. 17, 2003, which is a continuation of U.S. application Ser. No. 09/933,312, filed on Aug. 20, 2001. The disclosures of U.S. application Ser. Nos. 10/688,173 and 09/933,312 are hereby incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates generally to threaded fasteners. It relates particularly to locking fasteners of the type employing a threaded nut and a locking washer.
BACKGROUND OF THE INVENTION
[0003] A locking fastener or locking fastener assembly is employed to prevent loosening of a threaded fastener element in a fastener joint. There are numerous types of joints in which locking fasteners or fastener assemblies are not only desirable but necessary to prevent a nut from loosening. One such application is in the axle and wheel nut assembly of a motor vehicle or the like.
[0004] In a typical axle and wheel nut assembly, the hub is supported on a spindle by axle bearings which permit the hub, and thus a vehicle wheel, to rotate on the spindle. An axle bearing nut is threaded onto the free end of the spindle and holds the axle bearings and bearing races together in a predetermined relationship. The axle bearing nut must be set in precisely the proper position on the spindle to apply end loading on the bearing races sufficient to avoid excessive play in the bearings but insufficient to overload them, the result of either being possible bearing failure or even loss of a wheel.
[0005] Numerous types of nuts with positive locking components are well known. One of the oldest and most common of these is the conventional castellated nut and cotter pin assembly. The disadvantages of these assemblies are numerous. They include the necessity of carefully locating a hole through the axle spindle, of using an extra component, of reduced nut strength, of relatively long installation time and of the difficulties encountered in fine tuning the preload on the bearing races.
[0006] Newer developments in locking fastener assemblies include those found in the Anderson, Jr. U.S. Pat. No. 3,762,455, the Grube U.S. Pat. No. 4,812,094, the Burdick U.S. Pat. No. 5,533,849, and the Peterkort U.S. Pat. No. 5,597,278, for example. Of these, the Grube and Peterkort patents are assigned to the same assignee as the present invention, as will be noted.
[0007] The Peterkort patent discloses a locking fastener assembly consisting of a flanged nut and a retainer washer loosely seated on the nut's flange. The retainer washer includes a radially inwardly extending tab which is designed to slide axially along a slot in a threaded spindle while preventing the washer from rotating relative to the spindle. A releasable locking clip is positioned to lock the nut to the washer. The locking clip is released by engagement of a wrench socket with a hex-head on the nut so that the nut can be threaded to a desired bearing loading position. When the wrench is removed, the clip interlocks the washer and nut to prevent the nut from rotating.
[0008] The aforedescribed Peterkort locking fastener assembly is a highly effective device for use in vehicle wheel assemblies. It is simple and relatively inexpensive. However, its design focuses on limiting end play, not maintaining a constant preload.
[0009] Other known locking fastener designs include prevailing-torque locking fasteners. Locking action is achieved with frictional resistance induced between mating threads. There is positive resistance to assembly, which maintains throughout fastener seating and tightening. A high residual resistance to loosening remains even if fastener preload is lost. Disassembly is even difficult. Complete disengagement in service is highly unlikely. Prevailing-torque fasteners are generally all-metal fasteners with modified threads or fasteners with a separate non-metallic element or one fused to the threads. The former have fewer temperature and environmental limitations than the latter, but the latter do not encounter thread galling and other problems characteristic of the former.
SUMMARY OF THE INVENTION
[0010] It is an object of the present invention to provide an improved locking fastener assembly.
[0011] It is another object to provide a locking fastener assembly comprising only two components, a nut and a washer.
[0012] It is yet another object to provide a locking fastener assembly in which secure locking is achieved between a rotatable nut and a non-rotatable washer without the use of separate locking elements.
[0013] It is still another object to provide a locking fastener assembly including a new and improved locking mechanism.
[0014] It is a further object to provide a new and improved locking mechanism for a locking fastener assembly wherein a locking relationship is established directly between nut and washer.
[0015] It is yet a further object to provide a locking mechanism for a locking fastener assembly wherein a washer and nut interlock is established and a constant bearing load resiliently maintained when the assembly is employed to mount a vehicle wheel.
[0016] The foregoing and other objects of the invention are realized in a locking fastener assembly which comprises only a nut and a washer. Each is formed from medium carbon steel.
[0017] The washer includes a generally cylindrical washer body and a flange extending radially outward from the base of the body. A clamping surface is formed on the bottom of the flange and washer body base.
[0018] The top of the washer body has an annular, generally spherically concave load bearing surface formed on it. The load bearing surface includes an annularly extending series of inclined bearing faces forming a uniform undulation around the entire surface. A series of plateau surfaces between the inclined bearing faces form the upper peaks of the undulation. A series of valley surfaces between the inclined bearing faces form the valleys of the undulation. Each of the plateau and valley surfaces are spherically concave. Each of the inclined bearing faces is also spherically concave. The height of the plateau surface above the valley surface is slightly greater than the clearance between the threads in the nut and those on a vehicle axle spindle, for example, when the locking fastener assembly is in place.
[0019] The slightly concave washer body clamping surface on the bottom of the washer forms what approximates a shallow frustum of a cone. This surface is inclined upwardly from the outer periphery of the washer flange of its bottom toward the washer body axis.
[0020] The washer flange has a plurality of slots formed inwardly from its outer edge, at regular intervals around the flange. These slots permit intervening flange sections to resiliently flex, albeit only slightly, when the washer clamping surface is forced against an outer bearing race and is under the desired load.
[0021] An ear is formed inwardly of the base of the washer body, opposite the flange. The ear is designed to slide axially through a suitably formed slot in the threaded end section of an axle spindle to prevent the washer from rotating relative to the spindle as the nut is threaded onto this end section. In the alternative, a flat may be formed on the spindle and a corresponding flat formed inwardly of the washer body.
[0022] The nut includes a generally cylindrical nut body which is internally threaded. A hexagonal surface is formed around the periphery of the nut body to permit gripping the nut with a wrench.
[0023] Depending from the nut body is a unitarily formed annular skirt. The skirt is adapted to extend axially into the generally cylindrical body of the washer and then be formed outwardly under an undercut shoulder within the washer body to loosely, but securely, hold the washer and nut together.
[0024] The bottom of the nut body, above the skirt, has an annular, generally spherically convex load bearing surface formed on it. The load bearing surface includes an annularly extending series of inclined bearing faces forming a uniform undulation around the entire surface. A series of plateau surfaces between the inclined bearing faces form the lower peaks of the undulation. These plateau surfaces are spherically convex, with the same radius as the valley surfaces on the washer's load bearing surface. Each of the inclined bearing faces is also spherically convex, with the same radius as the bearing faces on the washer's nut bearing surface.
[0025] When the nut is threaded onto the axle spindle, the washer is pushed freely in front of it without rotating, until the slightly concave, frusto-conical clamping surfaces engage on the ends of the flange sections the inner bearing race of the outer bearing assembly supporting the wheel hub. Further axial travel of the washer is then resisted by the bearing race, first relatively lightly while the bearing races move closer together and then relatively firmly as the bearing races reach their operating positions.
[0026] Meanwhile, the peaks on the opposed undulating load bearing surfaces ride over each other with greater and greater difficulty as the load increases. Finally, they can slip past each other only when the flange sections on the washer begin to resiliently flex. The nut is then securely prevented from counter-rotating and loosening by the interlocking bearing faces and the resilient pressure of the washer.
[0027] In locked relationship, the spherically convex plateau surfaces in the load bearing surface of the nut seat flush against corresponding spherically concave valley surfaces in the load bearing surface of the washer. Also, the convex inclined leading bearing faces on the nut seat flush against the concave inclined trailing bearing faces of the washer and prevent the nut from backing off.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The invention, including its construction and operation, is illustrated more or less diagrammatically in the drawings, in which:
[0029] FIG. 1 is an end view of a vehicle axle and wheel hub incorporating a locking fastener assembly embodying features of the present invention;
[0030] FIG. 2 is a sectional view taken along line 2 - 2 of FIG. 1 ;
[0031] FIG. 3 is an exploded perspective view of a nut and washer in position to be assembled;
[0032] FIG. 4 is a bottom plan view of a locking washer assembly, partially in section;
[0033] FIG. 5 is a top plan view of a locking washer assembly, partially in section;
[0034] FIG. 6 is a side elevational view of a locking washer assembly, partially in section;
[0035] FIG. 7 is a plan view of a quarter segment of overlying opposed bearing surfaces on a nut and washer, showing their relationship to each other circumferentially;
[0036] FIG. 8 is an enlarged sectional view of an arcuate portion (on an 18° arc in the present illustration) of the mating bearing surfaces in the assembly, the view depicting curved bearing faces and surfaces as straight because of this;
[0037] FIG. 9 is a side elevational view of the nut, showing the convex curvature of its inclined bearing faces; and
[0038] FIG. 10 is a side sectional view through the washer, showing the concave curvature of its inclined bearing faces.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0039] Referring to the drawings, and particularly to FIGS. 1 and 2 , an axle assembly for an automotive vehicle is shown generally at 10 . The axle assembly 10 includes a spindle 12 which extends horizontally from a vertically oriented plate 14 . The plate 14 forms the outer face of a fitting 16 which is mounted in a conventional manner on the frame (not shown) of a vehicle.
[0040] Seated for rotation on the spindle 12 is a wheel hub 20 . The wheel hub 20 includes a generally cylindrical body 22 formed unitarily with a radially extending flange 24 . A plurality of studs 26 extend axially from the flange 24 near its periphery. The studs 26 are employed in a conventional manner to mount a wheel (not shown) on the wheel hub 20 .
[0041] The wheel hub 20 is seated on the spindle 12 on an inner roller bearing assembly 28 and an outer roller bearing assembly 29 . The inner bearing assembly 28 is located on a cylindrical inner section 31 of the spindle 12 and is retained between a shoulder 33 on the spindle and an opposing shoulder 35 inside the body 22 of the wheel hub 20 . The outer bearing assembly 29 is located on a cylindrical outer section 37 of the spindle 12 and is seated against a shoulder 39 inside the hub body 22 and against a frusto-conical spacer 41 encircling the tapered mid-section 43 of the spindle on the inner end of the bearing assembly.
[0042] The outer bearing assembly 29 is held in operating relationship against the shoulder 39 and spacer 41 by a locking fastener assembly 50 embodying features of the present invention. In this regard, the locking fastener assembly 50 is threaded onto the threaded outer end section 45 of the spindle 12 and seats against the inner bearing race 47 of the bearing assembly 29 .
[0043] The locking fastener assembly 50 is threaded onto the end section 45 of the spindle 12 to take up undesired play in the bearing assemblies 28 and 29 and, accordingly, hold them both in proper operating position and relationship. If the fastener assembly 50 is threaded too snugly against the bearing race 47 , the bearing assemblies 28 and 29 will both be over-loaded and their operating life shortened. If the fastener assembly 50 is not threaded sufficiently far onto the end section 45 , the bearing assemblies 28 and 29 will have too much play and their operating life will be shortened. The locking fastener assembly 50 is designed to be turned onto the threaded end section 45 of the spindle 12 to a desired position and then held securely in that position by locking forces exerted internally of the assembly according to the invention.
[0044] Referring now to FIGS. 3-10 , the locking fastener assembly 50 comprises only two components, a nut 52 and a retainer washer 54 . Both are forged steel elements. In the preferred embodiment shown here, the nut 52 is formed from medium carbon steel and then heat treated to an average hardness of 33 on the Rockwell C scale. The washer is also formed from medium carbon steel and then heat treated to an average hardness of 39 on the Rockwell C scale.
[0045] The nut 52 comprises a nut body 62 which is internally threaded at 64 for receipt of the threaded end section 45 of the spindle 12 . Externally, the nut body has a hexagonal shape surface 66 which is adapted to mate with a standard socket wrench for tightening and loosening the nut 52 .
[0046] Extending generally axially away from the nut body 62 at the inner end of the internal threads 64 is a skirt 68 . The skirt 68 extends away from the generally spherically convex load bearing surface 72 of the nut body 62 and through the retainer washer 54 . The skirt 68 is formed outwardly in a manner hereinafter discussed so that it retains the washer 54 on the nut 52 in loose relationship.
[0047] According to the invention, the generally spherically convex load bearing surface 72 on the nut body 62 is, in fact, an annularly undulating surface extending entirely around the nut body, as best seen in FIG. 9 . The surface 72 , which will hereinafter be described in greater detail, may be formed using any desired technique but, in the present instance, is formed by cold forging using a die insert which is machined to the desired complex curvature shape using conventional ball end mill techniques.
[0048] The washer 54 comprises an annular washer body 82 having a generally spherically concave load bearing surface 84 at its inner end and a clamp surface 86 for engaging the aforedescribed inner bearing race 47 at its outer end. The clamp surface 86 is formed on the outer end face 88 of the body 82 and a washer flange 92 which encircles it.
[0049] The generally spherically concave load bearing surface 84 on the inner end of the washer body 82 is also an angularly undulating surface extending entirely around the washer body, as best seen in FIG. 10 . The surface 84 , which will hereinafter be described in greater detail, is also formed by cold forging using a die pin which is machined on one end to the desired complex shape using conventional ball end mill techniques.
[0050] The outer end face 88 of the body 82 and flange 92 on the washer body 82 is slightly frusto-conical in shape. The end face 88 is inclined upwardly at an angle of approximately 3″ from the outer periphery 94 of the flange to the inner periphery 96 of the body 82 .
[0051] The flange 92 , which is approximately 0.12 inches (3.0 mm) thick in the washer 54 illustrated, is segmented by six cut-outs 98 around its circumference so as to define six radially extending flange sections 102 . The end face 88 is also interrupted by six Vee-shaped, depressions 104 extending radially inwardly from corresponding cut-outs 98 . This effectively separates the annular clamp surface 86 into six arcuate clamp surface segments 106 , the arcuate outer extremities of which, between cut-outs 98 , are able to resiliently flex axially of the washer 54 . Although the flange 92 is shown here separated into six flange sections 102 , however, it should be understood that the invention contemplates using a greater or lesser number depending upon the size of the washer and thickness of the flange.
[0052] Extending radially inwardly from the end face 88 is an ear 108 . The ear 108 is of a size and shape suitable to slide loosely in an axially elongated slot 49 formed on one side of the threaded end sections 45 of the spindle 12 . As will hereinafter be further discussed, when the fastener assembly 50 is installed, the ear 108 and slot 49 cooperate to prevent rotation of the washer 54 relative to the spindle 12 . Although the use of ear 108 and slot 49 cooperating to prevent washer 54 rotation is shown here in the context of vehicle hub 20 mounting, it should also be understood that the invention contemplates the use of other conventional means for preventing washer rotation.
[0053] Referring now in greater detail to the generally spherically convex load bearing surface 72 on the nut body 62 , it comprises a series of oppositely inclined side bearing faces, 73 with peaks in the form of plateau surface segments 74 and with narrow valley bottoms at lines 75 . Each pair of side bearing faces 73 with a valley floor line 75 between them forms what approximates an inverted Vee shape.
[0054] The plateau surface segments 74 are formed in the cold forging process so that they are all convex and lie on the surface of an imaginary sphere whose center is on the axis of the nut body 62 . In the nut 52 which is illustrated, and which has an outside diameter between flats of the hexagon of approximately 2.125 inches (54 mm) and a nut body 62 thickness of approximately 0.50 inches (12.7 mm), the radius of that sphere is 2.00 inches (50.8 mm).
[0055] Each inclined side bearing face 73 is also formed so that it is convex and is curved both radially and circumferentially of the nut body 62 . As will hereinafter be described, these convex surfaces 73 are formed so as to be complementary with corresponding concave side bearing faces in the generally spherically concave load bearing surface 84 on the washer body 82 .
[0056] In the nut body 62 illustrated, the height of each plateau surface segment 74 formed by adjacent side bearing faces 73 , i.e., the vertical height from the valley floor lines 75 , is 0.015 inches (0.38 mm). According to the invention, and for reasons hereinafter discussed, this height is slightly greater than the clearance between the threads on the end section 45 of the spindle 12 and the threads 64 in the nut body 62 when they are assembled.
[0057] Referring now in greater detail to the generally spherically concave load bearing surface 84 on the washer body 82 , the surface comprises a uniform series of inclined side bearing faces 116 with peaks in the form of plateau surfaces 118 and with wider valley floors in the form of valley surfaces 122 . Each pair of inclined bearing faces 116 with a valley surface 122 forms what approximates a Vee shape.
[0058] The valley floor surfaces 122 are formed in the forging process so that they are all concave and lie on the surface of an imaginary sphere whose center is on the axis of the washer body 82 . The radius of that sphere is 2.00 inches (50.8 mm). As such, it will be seen that the plateau surface segments 74 on the nut body 62 are perfectly complementary in shape to the valley floors 122 on the washer body 82 .
[0059] In the washer body 82 illustrated, the height of each plateau surface segment 118 , i.e., the vertical height from the valley floor 122 , is slightly less than 0.015 inches (0.38 mm). As a result, when nut 52 and washer 54 are seated against each other in nested relationship, each plateau surface segment 74 will seat uniformly on a corresponding valley floor 122 while opposed inclined bearing faces 73 and 116 will be slightly separated.
[0060] When the opposed bearing surfaces, surface 72 on the nut body 62 and surface 84 on the washer body 82 , are nested in locking relationship, however, the trailing inclined bearing faces 116 of the washer body 82 seat against the leading inclined bearing faces 73 on the nut body 62 . Because these opposed inclined bearing faces 73 and 116 are formed so as to be complementarily convex and concave, respectively, and all their radii of curvature axially of the assembly 50 and from its axis equal those of the aforementioned valley floor surfaces 122 , locking surface contact is maintained between them even if the nut 52 and washer 54 are not precisely parallel to each other because the nut does not thread perfectly squarely onto the spindle.
[0061] The nut 52 and washer 54 are assembled to create the locking fastener assembly 50 by inserting the skirt 68 of the nut through the washer in the manner best seen in FIG. 6 . The skirt 69 is then dimpled outwardly by forming at six evenly spaced locations 69 around its periphery so as to underlie an annular inward projection 83 in the washer body and, accordingly, loosely but securely connect the nut 52 and washer 54 while permitting the nut to rotate freely relative to the washer.
[0062] In use for securing a wheel hub 20 on the spindle 12 in an axle assembly 10 for a truck or some other vehicle, for example, after a wheel hub 20 has been seated on its supporting bearing assemblies 28 and 29 , a fastener assembly 50 is slipped over the threaded end section 45 of the spindle 12 so that the ear 108 in the washer 54 slides along the slot 49 in the spindle until the internal threads 64 in the nut body 62 engage the external threads on the spindle. The nut 52 is then threaded onto the spindle 12 by hand until the clamp surface 86 on the washer body 82 engages the inner bearing race 47 . As the nut 52 rotates while being threaded onto the spindle 12 in this way, the washer 54 moves axially with it but is prevented from rotating because its ear 108 is axially slidable in, but rotationally fixed by, the slot 49 in the spindle.
[0063] As the nut 52 rotates, its undulating bearing surface 72 slips easily over the opposed undulating bearing surface 84 on the washer 54 as the nut pushes the washer before it. When the clamp surface 86 engages the inner bearing race 47 , however, further rotation of the nut is resisted with greater and greater effect by the interlocking effect of the opposed inclined side bearing faces on the nut 52 and washer 54 , respectively, as the nut turns and axial pressure builds up in the bearing assemblies 28 and 29 . As this pressure builds up, the flange sections 102 begin to flex, creating a resilient force tending to keep the inclined bearing faces of opposed side bearing surfaces 72 and 84 in interlocked relationship.
[0064] The flange sections 102 are designed to resiliently flex through an axial distance which is slightly greater than the clearance between the spindle 12 threads and nut body 62 threads. Because the flange sections 102 are able to flex slightly more than this clearance, the washer 54 can move axially under load to some degree without degradation of the lock between washer 54 and nut 52 . At the same time, because the height of the plateau surface 118 above the valley surface 122 in the washer body 82 is slightly greater than the clearance also, once a locking relationship is established with the proper preload the nut 52 and washer 54 can move slightly relative to each other without loosening the fastener assembly 50 .
[0065] When a predetermined torque setting is reached in turning the nut 52 of the locking assembly 50 onto the spindle 12 , the bearing assemblies 28 and 29 are properly preloaded. The locking assembly 50 can then be relied upon to resist all axial forces tending to cause the nut 52 to back off. Increased axial load from the wheel hub 20 merely causes the nut 52 and washer 54 to become more securely locked together against relatively rotation. Only by applying loosening torque to the nut 52 again, as with a hex wrench, can the locking assembly 50 be removed.
[0066] Although the invention in a locking fastener assembly has been described in the context of a vehicle wheel hub mounting arrangement, it should be understood that it might be otherwise employed. Its two-part simplicity, rugged construction, virtually fail-proof action and low manufacturing cost may make it very attractive in many applications.
[0067] While a preferred embodiment of the invention has been described, it should be understood that the invention is not so limited, and modifications may be made without departing from the invention. The scope of the invention is defined by the appended claims, and all devices that come within the meaning of the claims, either literally or by equivalence, are intended to be embraced therein. | A locking fastener assembly comprising a nut and a washer. The nut and washer each have opposed load bearing surfaces which include a series of annularly extending, slightly inclined faces forming shallow undulations around each surface. The load bearing surface on the nut is generally spherically convex and the load bearing surface on the washer is generally spherically concave. The nut rotates as it is installed while the washer is prevented from rotating so that the undulating bearing surface on the nut slides over the undulating bearing surface on the washer against ever increasing resistance until the assembly is properly seated and the nut is effectively prevented from counter-rotating by interference between opposed, inclined faces. A concave clamping surface is formed on the outer end of the washer on a radially extending flange. The flange flexes when the assembly is installed and resiliently urges the washer against the nut. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to building safety and, more specifically, to a building evacuation system designed for the occupants of a building to escape pursuit or peril, such as fire, violence, natural catastrophe, or other emergency utilizing a deployable emergency exit incorporated into a building's exterior wall, such as a deployable hatch or window having an emergency exit deployment actuator mounted near the emergency exit that will simultaneously deploy the emergency exit, activate an internal audio and/or visual indicator to a central location that the emergency exit has been deployed, and initiate an automated text or voice message to the appropriate authorities, such as police and/or fire department, that the stated location's emergency exit has been deployed.
It should be noted that the building evacuation system of the present invention also provides for buildings having a plurality of deployable emergency exit stations and that a respective emergency exit actuator can be engaged by school aged children if need be.
2. Description of the Prior Art
While there are other building escape systems suitable for the purposes for which they were designed, they would not be as suitable for the purposes of the present invention, as hereinafter described.
It is thus desirable to provide a building emergency evacuation system providing a plurality of
SUMMARY OF THE PRESENT INVENTION
A primary object of the present invention is to provide an alternate emergency means for exiting a building other than the typical stairwell, elevator and exterior doors, which may be blocked, impassible or imperil the well being of the occupants to use.
Another object of the present invention is to provide a building with an emergency exit within a building's exterior wall having an actuator releasable hinged window.
Yet another object of the present invention is to provide at least one emergency exit for a building incorporating a chute that when deployed extends from the building's hinged window to the ground.
Still yet another object of the present invention is to provide a building emergency exit wherein said chute is contained within and deployable from a weatherproof housing.
An additional object of the present invention is to provide a building emergency exit wherein said chute's weatherproof housing is positioned approximately below the hinged window sill.
A further object of the present invention is to provide a building emergency exit wherein said chute is inflatable.
A yet further object of the present invention is to provide a building emergency exit wherein said chute is in fluid communication with a gas for inflating said chute.
A still yet further object of the present invention is to provide a building emergency exit having a breachable emergency exit actuator box having mechanical linkage for releasing said hinged window.
Another object of the present invention is to provide a building emergency exit wherein said mechanical linkage is in electrical communication with an annunciator circuit comprising audio and/or visual indicator that is energized when the mechanical linkage is engaged to release said hinged window.
Yet another object of the present invention is to provide a building emergency exit wherein said annunciator circuit further incorporates a civil authorities notification, such as police and fire department, comprising a text message or recorded message of the location and that one or more of the building's emergency exits have been deployed.
Still yet another object of the present invention is to provide a building emergency exit actuator box having a cover and tether tool that is used to breach the actuator box cover there by providing access to the mechanical linkage that will deploy the chute, release the window, energize the emergency exit actuated annunciator and transmit the civil authority notification of the deployment.
An additional object of the present invention is to provide a building emergency exit actuator box having a tethered tool for breaching the actuator box cover.
A further object of the present invention is to provide a building emergency exit that is easily deployed by an adult or child.
A yet further object of the present invention is to provide a system for escape from buildings whereby access to the window is made easier by providing fold out stairs for easier escape through said hatch.
Additional objects of the present invention will appear as the description proceeds.
The present invention overcomes the shortcomings of the prior art by providing a system for escape from public buildings and schools utilizing an inflatable slide for escape through hinged window(s) that deploys when an actuator box cover is breached providing access to mechanical linkage having a handle that when pulled inflates a chute, unlatches a hinged window, energizes a building annunciator indicating that the emergency exit has been deployed and initiates an automatic notification, either text or recorded message, sent to civil authorities, such as police and fire department, that an emergency exit has been deployed for a stated location.
The foregoing and other objects and advantages will appear from the description to follow. In the description reference is made to the accompanying drawing, which forms a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of the invention. In the accompanying drawing, like reference characters designate the same or similar parts throughout the several views.
The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is best defined by the appended claims.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
In order that the invention may be more fully understood, it will now be described, by way of example, with reference to the accompanying drawing in which:
FIG. 1 is an illustrative view of prior art.
FIG. 2 is an illustrative view of the emergency building exit of the present invention in use.
FIG. 3 is an illustrative view of the emergency building exit of the present invention.
FIG. 4 is a perspective view of the present invention.
FIG. 5 , shown is a perspective view of the present invention.
FIG. 6 is a perspective view of the exit actuator box and latched window.
FIG. 7 is an illustrative view of the emergency exit actuator box before deployment.
FIG. 8 is illustrative view of the means for inflating and deploying the inflatable chute of the present invention.
FIG. 9 is a sectional view of the present invention.
FIG. 10 is an illustrative view of the present invention.
DESCRIPTION OF THE REFERENCED NUMERALS
Turning now descriptively to the drawings, in which similar reference characters denote similar elements throughout the several views, the Figures illustrate the emergency escape system of the present invention. With regard to the reference numerals used, the following numbering is used throughout the various drawing figures.
10 emergency escape system of the present invention 12 school/public building 14 intruder 16 occupant 18 exterior wall of 10 30 window of 10 32 frame of 30 34 hinge of 30 36 latch of 30 38 chute housing 40 chute 42 propellant canister 44 emergency exit actuator housing 46 actuator housing breachable cover 48 tethered breach tool 50 emergency exit actuator 52 alarm switch 54 spring bob 56 spring 58 gas release actuator 60 steps of 18 62 emergency exit actuator indicator 64 exit portal
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The following discussion describes in detail one embodiment of the invention (and several variations of that embodiment). This discussion should not be construed, however, as limiting the invention to those particular embodiments, practitioners skilled in the art will recognize numerous other embodiments as well. For definition of the complete scope of the invention, the reader is directed to appended claims.
Referring to FIG. 1 , shown is an illustrative view of prior art. Secure schools and public buildings 12 are vulnerable to violent intruders 14 set on melee and destruction of facilities and people's lives. This violence has become a big problem nationwide. When an intruder 14 enters a facility, the people 16 inside are basically trapped with little or no escape. The present invention over comes this problem by providing an emergency escape system by one or more inflatable chutes that preferably extend from inside an office or schoolroom having an exterior wall incorporating a breachable actuator that will release a latched portal, deploy a chute, that extends to the ground and notifies building occupants and civil authorities of the chute deployment at the specified location.
Referring to FIG. 2 , shown is an illustrative view of the emergency building exit of the present invention. As aforementioned, the latched hinged window 30 forms the emergency exit 64 preferably within exterior wall 18 providing access to the chute 40 that is automatically inflated from within the waterproof housing, when the emergency exit actuator housing 44 is breached using the tethered breaching tool 48 and the emergency exit actuator (shown in FIG. 3 ) is moved from the closed position to the open position, whereby window 30 is unlatched wherethen the chute is inflated causing deployment. Simultaneously, an alarm switch is activated when the emergency exit actuator 50 is moved to its open position energizing emergency exit actuator indicator 62 informing the building occupants that an emergency exit has been activated and telephonically transmits either wired or wirelessly to civil authorities that the emergency escape system for a stated location has been activated.
Referring to FIG. 3 , shown is a perspective view of the present invention. Shown is the emergency escape system 10 in its closed position. The window and emergency actuation housing depicted mounted on the interior side of the wall is for illustrative purposes and is not intended as the only possible mounting for the emergency exit. It is also envisioned by the present invention that the window and actuator housing may be recessed into the wall. It should be noted that the chute housing may also be embedded within the exterior wall or attached to the exterior wall. To activate the emergency exit a user breaches the actuator housing breachable cover 46 using the breach tool 48 thereby gaining access to the emergency exit actuator 50 , which is in mechanical linkage with window 30 so that even if there is a power failure the emergency exit will still operate. The user moves the emergency exit actuator 50 from a closed or latched state to an open or unlatched state thereby engaging an alarm switch 52 to activate the internal building audible and/or visual alarm circuit 62 that will also notify the civil authorities. It should be noted that the present invention envisions the use of rechargeable batteries that can power the alarm circuit and telephonic communication with the civil authorities if needed. As aforementioned, the emergency exit actuator is mechanically linked to the window latching mechanism so that when the emergency exit actuator is moved to an open position it disengages from a spring bob having a mechanically linkage with a propellant canister that when disengaged inflates the chute providing means for occupants to quickly exit the building.
Referring to FIG. 4 , shown is a perspective view of the emergency exit actuator housing and latched window. The emergency exit actuator housing 44 is a sealed unit incorporating mechanical linkage 50 for releasing a window 30 from a closed state to an open state and inflating and deploying a chute; and alarm circuit switch means 52 for informing building occupants and civil authorities that an emergency exit has been deployed for a specified location.
Referring to FIG. 5 , shown is a perspective view of the emergency building exit in a closed state. The emergency escape system 10 provides means for a building's occupants to exit a building from any of a plurality of emergency escape exits incorporated into the exterior walls 18 of said building with each exit having an inflatable chute 40 that extends from a window 30 in an office or schoolroom to the ground and a wall mounted emergency exit actuator housing 44 having a breachable cover providing access to an emergency exit actuator 50 that will release the window from a latched state, inflate a chute 40 positioned under the window and energize an alarm system 52 that will audibly and/or visually 62 alert the building occupants that an emergency exit has been activated and alert civil authorities that an emergency exit for a designated location has been deployed.
Referring to FIG. 6 , shown is an illustrative view of the means for inflating and deploying the inflatable chute of the present invention. Shown is the emergency escape system being deployed. Once the cover has been breached, the emergency exit actuator 50 would be moved to disengage the spring bob 54 that would rise by virtue of spring 56 thereby disengaging the spring bob linkage from propellant canister 42 opening valve 58 releasing propellant 42 A thereby inflating the chute 40 with chute housing 38 . The set of steps can be pivoted from within the wall 18 below the window 30 to assist people up to the window 30 .
Referring to FIG. 7 , shown is a sectional view of the present invention. Shown is a sectional view of the components of the emergency escape system of the present invention. By releasing the emergency exit actuator from the spring bob 54 located within the window frame 32 , the spring bob 54 is lifted by the spring 56 disengaging the spring bob mechanical linkage from the gas propellant valve 58 thereby activating the inflatable chute's gas canister 64 . The inflatable chute 40 within housing 38 positioned below the window 30 is deployed thereby providing an emergency exit.
Referring to FIG. 8 , shown is an illustrative view of the emergency exit actuator box before deployment. The emergency escape system 10 provides means for a building's occupants to exit a building from any of a plurality of emergency escape exits incorporated into the exterior walls 18 of said building with each exit having an inflatable chute 40 that extends from a window 30 in an office or schoolroom to the ground and a wall mounted emergency exit actuator housing 44 having a breachable cover providing access to an emergency exit actuator 50 that will release the window from a latched state, inflate a chute 40 positioned under the window and energize an alarm system 52 that will audibly and/or visually 62 alert the building occupants that an emergency exit has been activated and alert civil authorities that an emergency exit for a designated location has been deployed.
Referring to FIG. 9 , shown is an illustrative view of the present invention. Shown is an exterior view of the emergency escape system deployed. The emergency exit provides an escape for occupants that leads directly to the exterior building ground. The system provides a latched window that can be unlatched through breaching an emergency exit actuator housing, moving the emergency exit actuator away from the window thereby releasing the window and further disengages linkage that will cause the propellant canister to inflate the chute positioned under the window within a housing 36 , which then deploys the chute 40 into engagement with the ground.
Referring to FIG. 10 , shown is an illustrative view of the emergency building exit of the present invention in use. The present invention is an emergency escape system 10 for schools and buildings comprising a latched hinged window 30 forming an emergency exit 64 providing access to a chute 40 that is automatically inflated from within a waterproof housing 38 and deploys when an emergency exit actuator housing 44 is breached and the emergency exit actuator moved to an open position. | A building evacuation system designed for the occupants of a building to escape pursuit or peril, such as fire, violence, natural catastrophe, or other emergency utilizing a deployed emergency exit incorporated into a building's exterior wall, such as a hinged latched window having an emergency exit deployment actuator mounted near the emergency exit that will simultaneously deploy an inflatable chute at the emergency exit, activate an internal audio and/or visual indicator to a central location that the emergency exit has been deployed, and initiate an automated text or voice message to the appropriate authorities, such as police and/or fire department, that the stated location's emergency exit has been deployed. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This continuation in part application claims the benefit of continuation in part patent application Ser. No. 13/455,046 filed on Apr. 24, 2012, which claims benefit of patent application Ser. No. 13/433,247 filed on Mar. 28, 2012, all of which are herein incorporated by reference.
FIELD OF THE INVENTION
[0002] This invention relates to lath furring strips. In particular, this invention relates to lath furring strips with improved water resistance and for accommodating insulation layers.
BACKGROUND OF THE INVENTION
[0003] The present invention is directed to overcoming problems associated with securing a lath to a sheathing (or a wall structure). In wall construction, plaster is generally applied to a flexible lath material instead of directly attaching the lath to a rigid structure, such as sheathing, because the current means of attaching a lath directly to a rigid structure can cause cracks. By applying plaster to a metal lath (which include structures such as welded wire, woven wire, and expanded metal lath), the plaster cracks less frequently than if compared to applying the plaster directly to the sheathing. The current method of fastening laths to sheathing is either with staples, nails or screws. Although a moisture barrier, such as building paper, can be placed between the lath and the sheathing, the moisture barrier must be penetrated by fasteners to secure the lath. This penetration creates holes which diminish the waterproofing features of the moisture barrier. When fasteners are driven into the sheathing, not only is the moisture barrier penetrated by the fastener, but often times the moisture barrier is torn by the lath, creating more possible water intrusion. Screw that press metal lath tear and cut the moisture barrier as they press the metal lath into the moisture barrier and sheathing. Since plaster is water absorbent, it can transmit water to more expensive and structurally important components of the building, such as the sheathing or the framing.
[0004] Lath furring strips are one way to reduce the number of penetrations into the moisture barrier because the lath is attached and secured to a furring strip, and not the sheathing or framing directly. An example of a lath furring strip is disclosed in U.S. Pat. No. 1,405,579 to Graham. This patent discloses placing a metal lath on a furring strip, which provides permanent spaces between the lath and the framing, which permits the ready application and attachment of continuous mesh reinforcements on a vertical stud. By using lath furring strips, fewer fasteners are needed to attach the furring strip to the sheathing, thus fewer penetrations are made into the moisture barrier. Furring strips have the added function of creating an air space between the sheathing and the lath, which serves the purpose of allowing the finishing material to key better, and creates insulation.
[0005] However, there are still problems with current lath furring strips. Although the use of furring strips reduces the number of holes in the moisture barrier compared to securing the lath to the moisture barrier directly, water can still seep into the sheathing and framing via the holes that were created by the furring strip fasteners. A problem with adding additional waterproofing layers to the furring strip is that any additional waterproofing on the furring strip would increase the profile height of the lath furring strip. For proper plastering of walls, the plaster thickness is commonly ⅞ of an inch, and the total height from the bottom of the furring strip cannot exceed ⅜ of an inch. However, one drawback of using a lath furring strip with a profile of less than ⅜ of an inch is that it may reduce the attachment strength on the furring strip where the lath is secured. This is due to the fact that an attachment hole, where a wire tie or clamp secures the lath to the furring strip, is situated on the mounting leg of a lath furring strip. The mounting leg is what gives most of the height to the lath furring strip. The attachment hole cannot be too large because the larger the attachment hole, the less metal there is between the outer edge of the attachment hole and the outer edge of the mounting leg. The less metal there is on this mounting leg, the more easily the lath can break off of the furring strip due to the small amount of metal holding the tie, lath, and mounting leg together. Although one might consider reducing the side of the attachment hole on the mounting leg, it takes skill insert wire ties through a lath and attachment hole, and reducing the size of the hole to leave more metal in between the attachment hole and the edge of the mounting leg would make it much more difficult for the practitioner to secure the lath to the mounting leg.
[0006] Additionally, some structures require increased insulation, and foam insulation on the outside of homes and buildings seems to be the current acceptable industry solution to the problems of new energy codes calling for higher R-values (a measure of thermal resistance used in the building and construction industry). Thermal bridging can be a major problem when structures are framed with metal studs because thermal bridging allows heat to pass through an insulating material via a conductive material that penetrates it. However, when lath is attached directly to foam insulation, there may be a lack of support because of the weight of the lath on the foam. Current methods use long fasteners, such as screws. These can be over three and one half inches long and puncture directly the thick foam insulation to secure the insulation to the framing. This attachment mechanism creates a potentially dangerous shear weight on the foam due to the weight of the plaster. Additionally, by using this method, there are as numerous penetrations in the weather resistant barriers behind the foam. Those penetrations have the potential for moisture intrusion into the building. When insulation is used as part of the furring strip assemblage, the height of the furring strip itself can be greater than ⅜ of an inches, but the distance from the lath to the insulation itself should be less than ⅜ of an inch for proper plastering of the wall. Currently there are no standardized three coat plaster systems that resolve the issues of thermal bridging, safe lath attachment, and penetration holes that reduce water resistance.
[0007] Therefore, there is a need for lath furring strips with properties that increase waterproofing without increasing the profile of the plaster thickness beyond ⅞ of an inch, and maintain mounting leg strength at the attachment site of the lath. Additionally, there is a need to integrally combine lath furring strips with other building structures to simplify construction and increase water proofing qualities of devices meant for the use plastering of walls. Finally, there is a need for lath furring strips that can resolve simultaneously the issues of thermal bridging, safe lath attachment, and problems relating to water resistive barrier penetrations.
SUMMARY OF THE INVENTION
[0008] In view of the foregoing, the present invention is directed to a lath furring strip and assembly of a lath furring system on a wall that allows for better waterproofing while maintaining mounting leg strength near a lath attachment hole and provide an area between the lath and furring strip for an insulating layer in some embodiments.
[0009] It is a purpose of the present invention to provide a low-profile lath furring strip that is more water resistant than currently available lath furring strips. The furring strip can be mounted onto the sheathing, framing or studding with a water resistive backing to reduce water seepage from the plaster to the wall, while maintaining a low height profile for proper plaster coating wall construction.
[0010] The present invention introduces such refinements. In a preferred embodiment, the invention comprises a lath furring strip that has a flexible elastic water resistive backing, such as a rubber sheet, on the bottom of the lath furring strip, which adheres or is secured to a moisture barrier such as building paper. The furring strip further comprises a mounting leg used to attach lath to furring strip. The total height from the top of the mounting leg to the bottom of the mounting plate (including all attachments to the base of the furring strip) is 0.365 inches or less. The mounting leg is hemmed such that there is additional metal between the edge of an attachment hole for a lath and the edge of the mounting leg. The fastener that attaches the wire lath to the furring strip can be a wire clip, a C ring, a wire tie, or other means to fasten a lath to a furring strip. The lath furring strip can also be incorporated into termination points, channel screeds, drips screeds and weep screeds to increase waterproofing material between a wall and plaster.
[0011] The rubber sheet can be fixed to the lath furring strip and has an adhesive coating, which may have a peelable layer, to temporarily secure the mounting plate on the furring strip to a solid barrier. A mounting device, such as a nail or screw, is inserted through the lath furring strip, to secure the furring strip to the sheathing or framing, and penetrates the moisture barrier. The furring strip may have pre-cut holes for mounting, or may have no mounting holes in its prefabrication embodiment, whereby the mounting holes are created with self-tapping screws or other mounting devices. The rubber backing on the furring strip aids in waterproofing because when the nail or screw that secures the furring strip to the sheathing applies pressure to the rubber backing, the rubber backing is squeezed such that it at least partially fills in any gaps that would normally allow water to seep through the mounting hole and building paper to the other side of the lath furring strip. This prevents water from seeping through any holes that were in the building paper and damaging more expensive structures such as sheathing, framing, or studding.
[0012] Incorporating a thick rubber sheet to the bottom of a lath furring strip increases waterproofing, but if a rubber sheet is too thick, such as 1/32, 1/16 or ⅛ of an inch, it would significantly raise the lath furring strip. This presents a problem because, the thicker the rubber sheet, the greater the height of the furring strip mounting leg. Preferably, the attachment hole is 5/16 of an inch for ease of a practitioner inserting an attachment device such as a wire tie. As the height of the lath furring strip increases with added layers such as rubber strips, the mounting legs must decrease to keep the overall height of the lath furring strip at or below 0.365 inches since the entire plastering thickness cannot exceed ⅞ of an inch. The lath furring strip can preferably be made from steel or other metals such as Galvanized steel or stainless steel.
[0013] In one embodiment of the present invention, the lath furring strip can be of different shapes, such as a shape that fits an inside corner, or a shape that fits an outside corner. The lath furring strip that fits an inside corner comprises two sides that mount against the solid barrier, such as sheathing, framing, wall, studding, or moisture barrier. Extending from each mounting plate is a mounting leg that is bent inward relative to the mounting plates of the lath furring strip. The lath is attached via attachment holes on the mounting legs. In the embodiment where the lath furring strip fits an outside corner, the furring strip has two plates that mount against the solid barrier or moisture barrier on sheathing. Extending from each mounting plate is a mounting leg that is bent outward relative to the mounting plates of the lath furring strip. The height of the furring strip from the base of the furring strip or the moisture barrier to the tip of the mounting leg, where the lath is attached, cannot exceed 0.365 inches. In the corner lath furring strip embodiments, the furring strip comprises a flexible elastic water resistant barrier, a first mounting plate for mounting said furring strip onto a solid barrier, a second mounting plate adjacent to, and substantially perpendicular to the first mounting plate, a mounting leg extending substantially perpendicular from the first mounting plate, a second mounting leg adjacent to, and substantially perpendicular to the second mounting plate, a first attachment hole for attaching lath to the furring strip to the first mounting leg, and a second attachment hole for attaching the lath to the second mounting leg. The first mounting plate is substantially parallel to the second mounting leg. The second mounting plate is substantially parallel to said first mounting leg. The first mounting plate is substantially perpendicular to said first mounting leg. The second mounting plate is substantially perpendicular to said second mounting leg. The mounting legs can either be bent inward (for use as an inside corner lath furring strip) or outward (for use as an outside corner lath furring strip) with respect to the mounting plates of the lath furring strip.
[0014] In another embodiment of the present invention, the lath furring strip can have a mounting leg of different shapes. By bending or curving the mounting leg, the height of the overall lath furring strip (including all flexible elastic water resistive barriers) can still remain at or under 0.365 inches. The advantage of a bent leg is that more metal can be between the attachment hole where the lath attaches to the lath furring strip, and the lengthwise edge of the mounting leg. In one embodiment with a bent mounting leg, the mounting leg can have a hairpin loop such that the leg is hemmed. In another embodiment of a bent mounting leg, the mounting leg can be bent such that the mounting leg has an additional extension leg that protrudes perpendicularly form the mounting leg. Preferably, the mounting leg and the extended part of the mounting leg are each equal to or less than 0.365 inches, and does not increase the total profile height of the lath furring strip to greater than 0.365 inches. Preferably, the size of the attachment hole for the lath is 5/16 of an inch. When a rubber backing is added to these furring strips, it raises the height of the furring strip. Since the height of the furring strip cannot exceed 0.365 inches, the height of the mounting leg must be reduced. Reducing the height of the mounting leg by bending the mounting leg in various configurations solves the problem increasing the amount of metal between the edge of the attachment hole and the edge of the mounting leg.
[0015] In another embodiment of the present invention, the flexible elastic water resistive barrier fits within a recessed area around the mounting hole, or if the mounting hole is not pre-punched, in an area that will become the mounting hole. This recessed area may be a continuous recessed area that runs substantially along the length of the furring strip, or the recessed area may be localized to just around where the mounting hole is or will be. The flexible elastic water resistive barrier can be a rubber gasket that is a long strip, which runs across a continuous recessed groove on the furring strip, or the flexible elastic water resistive barrier can be a small rubber gasket that fits within a punched-out area localized to the mounting hole area. The punched-out area can be circular or another shape where the gasket fits snugly within the recessed punched-out cavity. The gasket can have a pre-punched hole for a nail or screw to enter, or can be solid, and a hole will be made when a nail or screw pierces the gasket when it attached to the solid barrier. The advantage of a flexible elastic water resistive barrier in the recessed groove or cavity is that when these gaskets are squeezed due to the pressure caused by a nail or screw securing the lath furring to the sheathing or framing, the rubber fills in spaces in the mounting hole where water might have seeped into or out of, had there been no gasket. Preferably, the lath furring strip can have attachment holes on the mounting leg to attach the lath to the furring strip, as previously described. The mounting legs can have the same hemmed mounting legs as previously described to increase the strength of the mounting leg near the attachment holes.
[0016] In another embodiment of the present invention, the lath furring strips in the previously mentioned embodiments can be assembled with the lath and attached to sheathing and framing with termination points such as channel screeds or termination stops to form a lath and furring attachment system. The lath furring strip can be of the shape of any of the aspects previously mentioned aspects, and can have the flexible elastic water resistive barrier of any of the previously mentioned embodiments. In one embodiment, the lath and furring attachment system is comprised of a furring, a lath, and attachment device for securing the lath to the furring strip, a moisture barrier such as building paper, and another attachment device for securing the furring strip to a solid barrier such as sheathing or framing. The attachment device to attach the lath to the furring can be a tie (such as a wire tie, preferably 18 gauge), a clip, or C ring. A C ring may have the advantage of reducing the height profile of the assembled lath and furring system because wire ties have extensions that may protrude up through the plaster, while a C rings do not.
[0017] To apply plaster, an important aspect is the termination point. An effective method of achieving this termination is through a termination stop such as J-Moulding or Milcor, which is commonly used around windows or doors. J-Moulding provides a clean transition from stucco to an alternative surface. A channel screed can also be used in a lath furring system which creates a recessed reveal that offers an architectural accent while providing a control joint to help minimize cracking. A moisture barrier such as building paper can be placed in between the J-Moulding termination stop or channel screed and the sheathing. When termination points are added, this allows water to migrate through the furring system when installed at termination points above doors and windows. Preferably, in one embodiment, the moisture barrier can be layered such it lays on top of the termination stop but behind the furring strip. The channel screed or termination stop can also have the previously mentioned embodiments of the flexible elastic water resistive barrier incorporated into it. The termination stop and channel screed can be attached to the solid barrier via attachment devices such as screws or nails. The height of the furring strip from the tip of the mounting leg to the bottom of the furring strip used in this embodiment still is a maximum of 0.365 inches. Lath is attached to the furring strip via attachment holes on the mounting leg. The lath furring strips of this embodiment can be of any of the shape, and can have the waterproofing embodiments waterproofing embodiments previously described, or other embodiment with a flexible elastic water resistant barrier and bent mounting leg on a lath furring strip.
[0018] In another embodiment of the invention, a lath mounting device for mounting to a wall is comprised of a mounting leg, a first mounting plate and a second mounting plate. The first mounting plate has a front side and back side. The first mounting leg is formed at a substantially right angle to the front side of the first mounting plate and has at least one hole formed in the mounting leg for attaching lath. The second mounting plate is connected to the first mounting plate in a manner to permit the second mounting plate to be substantially parallel to the back side of the first mounting plate, the second mounting plate has a length greater than the first mounting plate. The second mounting plate has a terminal end that includes an angled leg that crosses the plane of the first mounting plate. The lath mounting device provides a unitary structure that creates two layers of plates to inhibit water penetration to the wall and also provides an angled leg formed with the device to channel water away at the bottom of the wall.
[0019] In another embodiment, the terminal end of the second mounting plate that includes an angled leg that crosses the plane of the first mounting plate creates weep screed that will prevent water from wicking up into the exterior plaster walls and also will allow water that may get into the walls to migrate out. This type of furring strip allows water to drip from the plaster on the outside of a wall by a window to drip down and away from the wall from an extension leg from the drip screed which is part of the lath furring strip. The weep screed has a longitudinal backing which is a second mounting plate that lies against a wall or sheathing, which is adjacent to the first mounting plate of the furring strip, forming a double layer of protection made from the furring strip material. A moisture barrier, such as building paper, adds another layer of protection by lying over the lath furring strip drip screed and over the mounting device, such as a screw, which secures the lath furring strip weep screed to the wall or sheathing. This moisture barrier adheres though an adhesive to the mounting plate of the lath furring strip such that water cannot seep up the furring strip to the holes creating by the mounting device, such as a screw. The maximum height from the backing of the lath furring strip weep screed mounting plate to the top of the mounting leg, which attaches the lath, is 0.365 inches, and to reduce the height of this mounting leg, embodiments, such as the ones previously described, may be employed.
[0020] In another embodiment, the terminal end of the second mounting plate that includes an angled leg that crosses the plane of the first mounting plate creates a drip screed that will prevent water from wicking up into the exterior plaster walls and also will allow water that may get into the walls to migrate out. This type of furring strip allows water to drip from the plaster on the outside of a wall by a window to drip down and away from the wall from an extension leg from the drip screed which is part of the lath furring strip. The drip screed has a longitudinal backing that lies against a wall or sheathing, which is adjacent to the first mounting plate of the furring strip, forming a double layer of protection made from the furring strip material. A moisture barrier, such as building paper, adds another layer of protection by lying over the lath furring strip drip screed and over the mounting device, such as a screw, which secures the lath furring strip drip screed to the wall or sheathing. This moisture barrier adheres though an adhesive to the first mounting plate of the lath furring strip such that water cannot seep up the furring strip to the holes creating by the mounting device, such as a screw. The maximum height from the backing of the lath furring strip drip screed mounting plate to the top of the mounting leg, which attaches the lath, is 0.365 inches, and to reduce the height of this mounting leg, embodiments, such as the ones previously described, may be employed.
[0021] In another embodiment, the terminal end of the second mounting plate that includes an angled leg that crosses the plane of the first mounting plate. The angled leg is substantially at a 90 degree angle from the second mounting plate and extends beyond the mounting leg. This angled leg has an additional bend that is substantially parallel to both the first and second mounting plates, which creates a termination stop. The two mounting plates provide an additional layer of furring material between the lath and the wall or sheathing. A screw, nail, or other mounting device secures the lath furring strip termination stop to the wall. Preferably, a moisture barrier, such as building paper is placed on top of the first mounting plate of the furring strip closest to the lath, and covers the mounting device such that water cannot enter the a hole created by the mounting device into the wall or sheathing. The moisture barrier preferably has an adhesive that secures the moisture barrier to the top of first mounting plate nearest the mounting leg to prevent any water from the lath to get in between the moisture barrier and the hole created by the mounting device. The maximum height from the back of the second mounting plate to the top of the mounting leg, which attaches the lath, is 0.365 inches, and to reduce the height of this mounting leg, embodiments that reduce the height of the mounting leg, such as the ones previously described, may be employed. The termination stop furring strip preferably has a total profile height of ⅞ of an inch from the mounting plate against the wall to the end of the termination stop leg.
[0022] In another embodiment of the invention, the lath furring strip is integral with a decorative metal trim, commonly referred to as a “reveal” that is used in construction of structures that will have a plaster exterior finish. Architects may specify that at various points on a wall that a reveal should be incorporated with lath furring strip to change the aesthetics of the plaster finish. In this unique embodiment, the lath furring strip will preferably incorporate lath furring at a consistent three eights of an inch and may provide openings every three and one quarter inches on the lath mounting leg for the wire tie method of lath attachment. The lath furring strip is installed to the wall or framing by fasteners, such as self-tapping screws, that secure mounting plates to a wall or framing covered by a moisture barrier, such as waterproof building paper. This embodiment has bottom mounting plates on each side of the reveal. The bottom side of the mounting plates attach to the wall or framing and form a bottom mounting plane against the wall. On top of each bottom mounting plate is a parallel top mounting plate, connected through a bend between the top and bottom mounting plates, forming a dual layer mounting plate on each side of the reveal. The reveal can preferably have triangular shaped protrusions, extending beyond the plane formed by the attached lath. Between the two triangular shaped protrusions is a recessed region that acts as part of the decorative trim. The embodiment may further have the flexible elastic water resistive backing on the furring strip to prevent moisture from seeping through holes created by the fastening device previously described, which can preferably be 1/32, 1/16, or ⅛ of an inch. This embodiment can also have the hemmed mounting legs to increase the amount of metal between the attachment holes on the mounting leg and the edge of the mounting leg to increase the stability of the structure between the attachment hole and the mounting leg edge. The lath furring strip has mounting legs with holes such that lath can be attached to this embodiment via a wire tie or other attachment device. The height of the lath furring strip from the bottom mounting planes of the furring strip to the top of the mounting legs is preferably 0.365 inches or less so that the lath can be at a consistent ⅜ of an inch from the wall or framing.
[0023] In still a further embodiment of the lath furring strip reveal, a moisture barrier can preferably be installed over the fasteners, and over the top mounting plates. This process will eliminate all of the penetrations in the moisture barrier secured by the lath. This process will eliminate the need for additional layers of moisture barriers that would be required around other types of decorative metal trim.
[0024] In another embodiment, the lath furring strip is a two-piece expansion joint used in construction of structures that will have a plaster finish on the exterior. Since construction codes call for plaster-finished exteriors to have expansion joints at specific intervals, this embodiment allows for the expansion and contraction of materials due to temperature changes. In this unique embodiment, each expansion joint is integral with a lath furring strip. This embodiment has two separate pieces, each piece can secure lath via an attachment device such as a wire tie, through holes on mounting legs. Each of the expansion joints can be secured to a wall or framing through via mounting devices such as screws, self-tapping screws, or nails. The two-piece expansion joint can be installed to provide a variable size to the expansion joint width depending on the width the architect would specify in the plans. In the first expansion joint, there are a is a bottom mounting plate and a top mounting plate, forming a dual layer mounting plate where the plates are substantially parallel to each other. The bottom side of the mounting plates attach to the wall or framing and form a bottom mounting plane against the wall. The dual layer mounting plates can be secured to a wall or framing by the use of a screw or nail. Extending substantially perpendicular from the top mounting plate is a mounting leg, which has holes for securing lath to the first expansion joint. The bottom mounting plate extends past the mounting leg to a distance such that the second expansion joint can overlap the first expansion joint. As the bottom mounting plate extends past the mounting leg, it bends to form a horizontal termination leg, which is parallel to the bottom mounting plate, forming a dual layered bottom mounting plate and horizontal termination leg. Extending substantially perpendicular from the horizontal termination leg is a vertical termination leg, extending preferably seven eights of an inch. Extending substantially perpendicular from the vertical termination leg is a termination flange.
[0025] A second expansion joint can be placed over the first expansion joint such that the horizontal termination leg of the second expansion joint is on top of the horizontal termination leg of the first expansion joint. The second expansion joint is able to sit flush with the first expansion joint because the second horizontal termination leg is raised compared to the horizontal termination leg on the first expansion joint. This raised horizontal termination leg is achieved through a flared region on the bottom mounting plate on the second expansion joint. The bottom side of the mounting plate attaches to the wall or framing and form a bottom mounting plane against the wall. The flare extends away from the plane of the wall when the furring strip secured, creating a space for the first expansion joint to fit under the second expansion joint. This design is unique in that it provides a pre-tensioned bend in the metal to allow for a tight seal when the expansion joints are secured to a wall or framing with a lath furring strip. This greatly improves moisture intrusion protection. Parallel and on top of the bottom mounting plate on the second expansion joint is a top mounting plate formed by a bend between the top and bottom mounting plates. Extending substantially perpendicular from the top mounting plate is a mounting leg for attaching lath. The second expansion joint is secured to a wall or framing via a mounting device such as a screw, self-tapping screw, or nail. Preferably, between the wall and the two-piece expansion joint is a moisture barrier. Preferably, a water barrier will be installed over the fasteners that secure the expansion joints to the wall to eliminate all of the penetrations in the moisture barrier around the expansion joints. Preferably, the distance from the bottom mounting planes to the top of each mounting leg that secures the lath through attachment holes is 0.365 inches or less so that lath can be incorporated a consistent ⅜ of an inch from the wall or framing. This embodiment may further have the flexible elastic water resistive backing on the expansion joints, which can preferably be 1/32, 1/16, or ⅛ of an inch, to prevent moisture from seeping through holes created by the fastening device previously described. This embodiment may also have the hemmed mounting legs to increase the amount of metal between the attachment holes on the mounting legs and the edge of the mounting leg to increase the stability of the structure between the attachment holes and the mounting leg edges.
[0026] In another embodiment of the invention, a lath furring strip is incorporated with a window furring strip. This embodiment is for use around windows constructed with plaster depth grounds incorporated in the window design from the manufacturer. The furring strip has a bottom mounting plate which is parallel and integral with a top mounting plate, formed by a bend between the two mounting plates. Extending substantially perpendicular is a mounting leg for securing lath to the mounting leg via a hole on the mounting leg. Preferably, the distance from the plane formed by the bottom of the bottom mounting plate and the top of the mounting leg is not greater than 0.365 inches so that lath can be secured at a uniform ⅜ of an inch from the wall or framing. This embodiment is unique in that it designed to have a pre-tensioned shape in the metal or the strip to allow the embodiment to seal tightly against the window flange and also has a water resistant lath furring strip, which prevents water from penetrating the wall or framing. Preferably, a moisture barrier is placed on top of the top mounting plate and on top of the fastening device, which eliminates any moisture barrier penetration around the window and the need for additional water barrier product, such as Biuthane or rubber to be layered into the window flashing. Extending from the bottom mounting plate is a flared region that angles away form the plane of the bottom mounting plate. Extending from this flared region is a flashing plate. The combination of the flare and the flashing plate creates a space such that the flashing plate can lay on top of the window flange. When the furring strip is secured to the wall or framing, the flashing plate of the furring strip is pressed against the window flashing, creating a more waterproof barrier between the two. Preferably, the bottom mounting plate can have a flexible elastic barrier to improve water resistance, which can preferably be 1/32, 1/16, or ⅛ of an inch, and can prevent water from seeping from the plaster into the wall or framing. Preferably, a moisture barrier may be placed on top the top mounting plate such that any hold created by the screw or other mounting device the secured the furring strip to the wall is covered. Preferably, the mounting leg can be a hemmed mounting leg such that more metal is between any attachment hole on the mounting leg and the edge of the mounting leg.
[0027] In another embodiment of the invention, there is provided a space on the furring strip such that an insulation layer such as foam can be placed between the lath and the furring strip. Only the furring strip, and not the insulation is penetrated to secure it to a wall. This feature decreases the number of holes that penetrates into a wall, thus improving water resistance, as well as eliminates excessive sheer weight on the insulation, since the lath is attached to the furring strip and not the insulation directly. In this embodiment, the furring strip has a bottom mounting plate having an interior side that is substantially planar and the interior side is used for placement substantially flush against the wall. The lath furring strip also has a bottom mounting plate having an exterior side that is substantially planer. The top bottom mounting plate and the top mounting plate are substantially parallel to each other and secured together in a manner that maintains a gap between them. The insulation is positioned against the exterior side of the top mounting plate. A mounting leg is secured to, and extends substantially perpendicular from the stop mounting plate and also passes though the insulation. The mounting leg has at least one attachment hole for securing the lath the furring strip. This positioning of the insulation layer between the lath and the mounting plates allows only the penetration of the furring strip and not the insulation later. This protects against water intrusion between the insulation layer is not penetrated and also protects against thermal bridging. In one embodiment, the distance from the top vertical edge of the mounting leg to the attachment hole is not greater than 0.365 inches such that when the insulation is placed between lath and the furring strip, the distance from the top of the insulation to the lath does not exceed 0.365 inches. This distance ensures proper keying of the plaster.
[0028] In one embodiment of a lath furring strip for use with an insulation layer, the lath furring strip is designed to be placed over a window flange to better protect against water intrusion from around window. There is provided a flared extension extending angularly from the bottom mounting plate to accommodate the thickness of the window flange. From this flared extension is provided a flashing plate that is substantially planar and is placed substantially flush against a window flange. The flashing plate extends from the flare extension. This design allows for the furring strip to seal tightly against a window flange providing superior moisture protection.
[0029] In another embodiment of a lath furring strip for use with an insulation layer, the lath furring strip is integrated with a drip screed. The drip screed has a drip screed leg extending obtusely and contiguous with the lath furring strip bottom mounting plate. In this embodiment, any water from the plaster would drip down and drip away from the wall since the drip screed leg protrudes away from the wall.
[0030] In another embodiment of a lath furring strip for use with an insulation layer, the lath furring strip is integrated with a weep screed leg. The weep screed has a first weep screed leg extending away from the bottom mounting plate at an obtuse angle. There is provided a second weep screed leg which is contiguous with the first weep screed leg, which extends acutely from the first weep screed leg. The weep screed forms an open triangular-like shape, with the open part facing toward the wall when the furring strip is installed substantially flush against the wall. There may be provided an extension plate extending angularly from the second weep screed leg for placement of the extension plate substantially flush against the wall. This embodiment prevents water from wicking up into the exterior plaster wall, and also allows water that may get into the walls to migrate out, and has the additional features of allowing enough space to place an insulation layer between the lath and the to mounting plate of the furring strip.
[0031] In another embodiment of a lath furring strip for use with an insulation layer, the lath furring strip is integrated with a termination stop. The termination stop has a termination stop leg which extends substantially perpendicular to the bottom mounting plate, and substantially parallel to the mounting leg. The termination stop leg has a greater length than the mounting leg. There may be provided a termination stop leg extension which is substantially perpendicular to the termination stop leg. This provides an effective method of achieving stop points commonly used around windows or doors.
[0032] In another embodiment, the lath furring strip for use with an insulation layer can be designed for use around an outside corner of a wall. There is provided a first mounting plate having an interior side that is substantially planar, for placement substantially flush against the wall and an exterior side for placement of the insulation layer. There is also a second mounting plate having an interior side that is substantially planar, which has an interior side for placement substantially flush against the wall and a second exterior side for placement of the insulation layer. The second mounting plate is substantially perpendicular to the first mounting plate. This lath furring strip also has a first mounting leg extending angularly from the first mounting plate which has a first attachment hole for attaching lath. There is provided a second mounting leg extending angularly from the second mounting plate, which has a second attachment hole for attaching lath. The first and second mounting leg and second mounting leg are secured to each other. The insulation layer is positioned against the first and second exterior sides of the first and second mounting plates. There may be provided a top edge connecting the first and second mounting legs and the distance between the first and second attachment holes to the top edge is not greater than 0.365 inches. The first mounting leg may be obtusely angled from the first mounting plate and the second mounting leg may be angled obtusely from the second mounting plate. This arrangement for superior insulation and moisture protection when the insulation layer is placed between the mounting plates the lath because the only penetration into a wall is a screw or other attachment device that penetrates the furring strip and not the insulation layer itself.
[0033] In another embodiment of a lath furring strip for use with an insulation layer, a flexible elastic water resistive barrier fits within a recessed area on a mounting plate. There is provided a mounting plate having an interior side that is substantially planer, and the interior side has a recessed groove for placement of a flexible elastic barrier. The mounting plate also has an exterior side. A mounting leg is secured to and extends substantially perpendicular form the mounting plate. An insulation layer is positioned against the exterior side of the mounting plate and the mounting leg passes through the insulation. The recessed groove may run substantially across the length of the mounting plate. The mounting leg may have a top vertical edge and the distance between the attachment hole and the top vertical edge is not greater than 0.365 inches. The advantage of a flexible elastic water resistive barrier in the recessed groove is that when gaskets (i.e. the flexible elastic water resistive barrier) are squeezed due to the pressure caused by a nail or screw securing a furring strip to the wall, the elastic fills in spaces in the mounting hole where water might have seeped into or out of, had there been no gasket.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The above and various other objects and advantages of the invention will be described and understood from the following description of the preferred embodiments of the invention, the same being illustrated in the accompanying drawing.
[0035] FIG. 1 a is a side elevation view of a lath furring strip with a rubber backing, and a single mounting leg.
[0036] FIG. 1 b is a perspective view of a lath furring strip having a rubber backing.
[0037] FIG. 2 a is a side elevation view an inside corner lath furring strip having a rubber backing.
[0038] FIG. 2 b is a perspective view of an outside corner lath furring strip.
[0039] FIG. 3 a is a side elevation view of outside corner lath furring strip.
[0040] FIG. 3 b is a perspective view of an outside corner lath furring strip.
[0041] FIG. 4 a is a side elevation view of a lath furring strip having a hemmed mounting leg.
[0042] FIG. 4 b is a perspective view of a lath furring strip having a hemmed mounting leg.
[0043] FIG. 4 c is a side elevation view of a lath furring strip having a bent mounting leg.
[0044] FIG. 4 d is a perspective view of a lath furring strip having a bent mounting leg.
[0045] FIG. 5 a is a side elevation view of a lath furring strip having a continuous recess for a rubber gasket.
[0046] FIG. 5 b is a perspective view of a lath furring strip having a continuous recess for a rubber gasket.
[0047] FIG. 6 a is a sectional view of a lath furring strip having punched holes with rubber gasket inserts.
[0048] FIG. 6 b is a side elevation view of a lath furring strip having punched holes with rubber gasket inserts.
[0049] FIG. 6 c is a perspective view of a lath furring strip having punched holes with rubber gasket inserts.
[0050] FIG. 7 is a side elevation view of an assembled lath and lath furring strip mounted to a sheathing and framing.
[0051] FIG. 8 is a side elevation view of an assembled lath and lath furring strip mounted to a sheathing and framing with overlapping waterproof paper.
[0052] FIG. 9 a is a side elevation view of a furring strip integrated with a weep screed.
[0053] FIG. 9 b is a side elevation view of a furring strip integrated with a weep screed and with an assembled lath and mounting screw.
[0054] FIG. 10 a is a side elevation view furring strip integrated with a termination stop.
[0055] FIG. 10 b is a side elevation view of a furring strip integrated with a termination stop and assembled lath and mounting screw.
[0056] FIG. 11 a is a side elevation view of a furring strip integrated with a drip screed.
[0057] FIG. 11 b is a side elevation view of a furring strip integrated with a drip screed and assembled lath and mounting screw.
[0058] FIG. 12 a is a side elevation view of a reveal furring strip.
[0059] FIG. 12 b is a side elevation view of a reveal furring strip assembled with a lath and moisture barrier.
[0060] FIG. 13 a is a side elevation view of a two-piece expansion joint furring strip.
[0061] FIG. 13 b is a side elevation view of a two-piece expansion joint furring strip assembled with a lath and moisture barrier.
[0062] FIG. 14 a is a side elevation view of a window furring strip.
[0063] FIG. 14 b is a side elevation view of a window furring strip assembled with a lath and moisture barrier.
[0064] FIG. 15 a is a side elevation view of a furring strip integrated with a weep screed for foam installation.
[0065] FIG. 15 b is a side elevation view of a furring strip integrated with a weep screed and with an assembled lath and mounting screw for foam insulation.
[0066] FIG. 16 a is a side elevation view of a furring strip integrated with a drip screed for foam insulation.
[0067] FIG. 16 b is a side elevation view of a furring strip integrated with a drip screed and assembled lath and mounting screw for foam insulation.
[0068] FIG. 17 a is a side elevation view furring strip integrated with a termination stop for foam insulation.
[0069] FIG. 17 b is a side elevation view of a furring strip integrated with a termination stop and assembled lath and mounting screw for foam insulation.
[0070] FIG. 18 a is a side elevation view of a lath furring strip having a continuous recess for a rubber gasket for foam insulation.
[0071] FIG. 18 b is a perspective view of a lath furring strip having a continuous recess for a rubber gasket for foam insulation.
[0072] FIG. 18 c is a side elevation view of a lath furring strip having a continuous recess for a rubber gasket assembled with a lath and mounting screw for foam insulation.
[0073] FIG. 19 a is a side elevation view of an outside corner lath furring strip.
[0074] FIG. 19 b is a side elevation view of an outside corner lath furring strip assembled with a lath and mounting screw for foam insulation.
[0075] FIG. 20 a is a side elevation view of a window furring strip for foam insulation.
[0076] FIG. 20 b is a side elevation view of a window furring strip assembled with a lath and moisture barrier for foam insulation.
DETAILED DESCRIPTION OF THE INVENTION
[0077] The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims. Preferable embodiments of the present invention are described with reference to the FIGS. 1-20 . FIG. 1 , FIG. 5 , and FIG. 6 show various embodiments of increasing the waterproofing characteristics of the lath furring strip. FIG. 2 , FIG. 3 , and FIG. 4 show various embodiments of the shape of the lath furring strip without any waterproofing elements, but can incorporate the waterproofing elements of the embodiments in any other figure. FIG. 7 and FIG. 8 show various embodiments of how the lath furring strip and lath are assembled, and may incorporate any of the waterproofing or lath shapes in any of other figures. FIG. 9 , FIG. 10 , FIG. 11 , FIG. 12 , FIG. 13 , and FIG. 14 show various embodiments of integrating a lath furring strip with termination stops, screeds, such as weep screed and drip screed, window furring, reveal trims, and two-piece expansion joints. FIG. 15 , FIG. 16 , FIG. 17 , FIG. 18 , FIG. 19 , and FIG. 20 show various embodiments of integrating a lath furring strip in weep screeds, window heads, window stops, and O/S corners when insulation, such as foam insulation needs to be placed between the sheathing and the lath. These embodiments can be combined with other embodiments described below.
[0078] FIG. 1 a and FIG. 1 b depict a lath furring strip 10 which has a mounting plate 20 and a mounting leg 2 , which is substantially perpendicular to the mounting plate 20 . On the bottom 22 of the mounting plate 20 is a flexible elastic water resistive barrier 6 such as a rubber sheet, fixed to the bottom side 22 of the furring strip 10 . The height of the lath furring strip 10 from the bottom of the flexible elastic resistive barrier 6 to the top of the mounting leg 12 does not exceed 0.365 inches. The mounting side 20 has a top side 16 and a bottom side 22 . A mounting hole 8 traverses the mounting plate 20 and goes through the top side 16 to the bottom side 22 . A nail or screw can be inserted into the mounting hole 8 to secure the lath furring strip 10 to the solid barrier, such as sheathing, framing, studding, or wall, and may attach to a solid barrier through an intermediary moisture barrier, such as a building paper. The mounting hole can also be created by the use of self tapping screws. The mounting leg 2 , where the lath is attached, may attach attaches via a clip, wire tie, C ring, or other means of securing a lath to the attachment hole 14 . The attachment hole may span both the mounting plate 20 and mounting leg 2 . The mounting leg 2 is integral with lath furring strip 10 and created by a bend 4 that forms a substantially perpendicular mounting leg 2 relative to the mounting plate 20 . The flexible elastic water resistive barrier 6 may have an adhesive coating on the bottom of the flexible elastic water resistive barrier 6 such that the furring strip 10 can adhere to a solid barrier or moisture barrier.
[0079] FIG. 2 a and FIG. 2 b show two views of an example of a furring strip 30 used for an inside corner of a wall. A first side 32 of the furring strip 30 has a mounting hole 36 . A screw or nail can be used to secure the first mounting plate 32 to a solid barrier such as a wall, sheathing, or framing, which has corner, and may attach to the solid barrier through an intermediary moisture barrier, such as building paper. A second mounting plate 34 of the furring strip 30 also has a second mounting hole 38 and is secured to a solid barrier. The corner 58 of the furring strip 30 nestles into the corner of the structure which the furring strip 30 attaches to. The furring strip 30 has a first mounting leg 40 and a second mounting leg 54 , which are each equal or less than 0.365 inches from the top of the mounting leg 46 to the bottom of the first mounting plate 32 or second mounting plate 34 of furring strip 30 . An attachment hole 60 on the first mounting plate 32 and an attachment hole 52 on the second mounting plate are used to attach a lath to the furring strip via a wire tie, clip or C ring. The attachment hole 60 may span both the first mounting plate 32 and the first mounting leg 40 through the corner 44 of the first mounting plate 32 and first mounting leg 40 . Similarly, the attachment hole 52 on the second mounting plate 34 may span the corner 56 of the second mounting plate 34 to the second mounting leg 54 . In a cross sectional view of the furring strip 30 , the furring strip 30 forms an open square-like structure as shown in FIG. 2 a , where the first mounting plate 32 and the second mounting plate 34 are two sides of the open square, with the corner 58 between these two mounting plates 32 , 34 . The first mounting side 32 and the first mounting leg 40 are at substantially a right angle to each other, and meet via a corner 42 . The second mounting plate 34 and second mounting leg 54 are substantially at a right angle to each other and meet via a corner 56 . A lath can take the cornering shape of the furring strip 30 by attaching a lath that is perpendicular to the mounting legs 40 , 54 , and parallel to the two mounting plates 32 , 34 via attachment devices that connect the lath to the attachment holes 52 , 60 . The furring strip 30 can have a flexible elastic waterproof barrier as shown in FIG. 1 , FIG. 5 , FIG. 6 , or other type of flexible elastic water resistive barrier.
[0080] FIG. 3 a and FIG. 3 b show two views of an example of a furring strip 70 meant for use on an outside corner of a wall. A first mounting plate 76 of the furring strip 70 has a mounting hole 80 where a screw or nail can be inserted and secures the furring strip 70 to a solid barrier such as a sheathing, framing, or wall. A mounting hole 82 on a second mounting plate 74 secures the furring strip 70 to a solid barrier on an outside corner. The corner 88 of the furring strip 70 nestles in the corner of a wall for attachment. Extending from the first mounting plate 74 and the second mounting plate 76 are a first mounting leg 78 and a second mounting leg 72 , respectively. The first mounting leg 78 is substantially perpendicular to the first mounting plate 76 and meet at a corner 98 . The second mounting leg 72 is substantially perpendicular to the second mounting plate 74 and meet at a corner 96 . The height of furring strip 70 from the tip 92 of the first mounting leg 78 to the base of the first mounting plate 76 is equal to or less than 0.365 inches. Likewise, height from the tip 94 of the second mounting leg 72 to the base of the second mounting plate 74 is also equal to or less than 0.365 inches. An attachment hole 86 secures a lath to the furring strip 70 , and this attachment hole 86 may span both the first mounting side 76 and first mounting leg 78 . Another attachment hole 84 secures a lath the furring strip 70 , and this attachment hole 84 may span both the second mounting plate 74 and second mounting leg 72 . The first and second mounting plates 74 , 76 can have the flexible elastic waterproof barriers as depicted in FIG. 1 , FIG. 5 , FIG. 6 , or other embodiments of a flexible elastic waterproof barrier.
[0081] FIG. 4 a and FIG. 4 b are two views of another embodiment of a furring strip 100 . In this embodiment, the mounting leg 122 is hemmed, such that it is bent on an edge 102 . The height from the bottom 114 of the furring strip 100 to the top of the bent edge 102 is no greater than 0.365 inches. This bend forms a hairpin loop 104 with an opening 106 , which increases the amount of total furring strip material from the attachment hole 124 to the edge of the mounting leg 122 . The furring strip 100 has a mounting hole 188 within the mounting plate 120 . A screw, nail, or other attachment device secures the furring strip 100 to a solid barrier, such as sheathing, framing, or wall. On top of this solid barrier there may be a moisture barrier such as building paper. The mounting plate 120 can have a flexible elastic water resistive barrier 116 on the bottom 114 of the mounting plate 120 , or can have flexible elastic water resistive barriers of other embodiments as depicted in FIG. 1 , FIG. 5 , FIG. 6 , or other embodiments. The feature of a hemmed mounting leg 122 in FIG. 4 b increases the strength of the mounting leg 122 because of additional furring strip material between the attachment hole 124 and the edge of the mounting leg 122 . The furring strip 100 has an attachment hole 124 for attaching a lath to the furring strip 100 .
[0082] FIG. 4 c and FIG. 4 d depict another embodiment of a furring strip 110 that increases the total amount of furring strip 110 material (such as steel or stainless steel) that is on the mounting leg 142 . The mounting leg 142 can be bent perpendicularly to make an edge 140 , such that the extension leg 138 of the mounting leg 142 is no longer than 0.365 inches, and the mounting leg 142 with the attachment hole 126 is also no longer than 0.365 inches. The attachment hole 126 may span the mounting plate 144 through a corner 134 that is formed between the mounting leg 142 and the mounting plate 144 . The total height from bottom 130 of the mounting plate 144 to the top of the extension leg 138 is no greater than 0.365 inches. The furring strip 110 may incorporate various embodiments of a flexible elastic water resistive barrier such as the embodiments depicted in FIG. 1 , FIG. 5 , FIG. 6 or other embodiment of a flexible elastic waterproof barrier on a furring strip.
[0083] FIG. 5 a and FIG. 5 b illustrate two views of a furring strip 150 with a recessed groove 154 for a rubber gasket 152 . The recessed groove 154 allows flexible elastic water resistive barrier, such as a rubber gasket 152 to line a mounting hole 168 without increasing the overall height of the furring strip 150 , such that the distance from the bottom side 172 of the mounting plate 164 to the tip 174 of the mounting leg 170 does not exceed 0.365 inches. The recessed groove 154 can be within the bottom side 172 of mounting plate 164 of the furring strip 150 . The top surface 178 of the mounting plate 164 , which has a mounting hole 168 can be raised out to provide a thickness of the recessed area of the furring strip 150 material equal to the thickness of the furring strip 150 material through the rest of the mounting plate 164 . The recessed groove 154 can be implemented in other designs of furring strips, such as the ones illustrated in FIG. 2 , FIG. 3 , or FIG. 4 . The recessed groove 154 can have a variety of shapes that enable it to fit a rubber gasket 152 . A first side 156 of the recessed groove 154 can be angled towards a mounting hole 168 , forming an obtuse angle from the bottom side 172 of the furring strip 150 towards the mounting hole 168 , and a second side 158 of the recessed groove 154 , which is closer to the mounting leg 170 also forms an obtuse angle from the bottom side 172 of the mounting plate 164 towards the mounting hole 168 . The top surface of the recessed groove 154 can be flat with no angles such that it fits a rubber gasket 152 with a flat top side. The recessed groove 154 can also be of other shapes that fit differently shaped gaskets.
[0084] In another embodiment, the recessed groove can be angled from the bottom side 172 of the mounting plate 164 such that a first side of the flare 160 closest to the mounting leg 170 , and the recessed groove closest to the non-raised portion 162 of the furring strip 150 , both recess in a perpendicular fashion in relation to the bottom side 172 of the mounting plate 164 before being angled in toward each other. A nail or screw attaches the furring strip 150 to a solid barrier such as a sheathing, wall, or framing by securing the furring strip 150 through via the mounting device through the mounting hole 168 . The furring strip 150 also has an attachment hole 173 to secure the lath to the furring strip 150 .
[0085] FIG. 6 a , FIG. 6 b , and FIG. 6 c illustrate three views of a furring strip 180 with punched holes 196 for a rubber gasket 198 . This feature enables the furring strip 180 to have an flexible elastic water resistive barrier nestled within the furring strip 180 , but does not add any height to the furring strip 180 , such that the height from the tip 182 of the mounting leg 184 to the bottom of the bottom of the mounting plate 188 does not exceed 0.365 inches. The furring strip 180 is secured to a solid barrier such as sheathing, framing, or a wall via a screw or nail that goes through the mounting hole 196 and rubber gasket 198 . The rubber gasket 198 can have a hole 200 within it, such that the nail or screw can pass through the mounting side 190 more easily. The top of the mounting plate 192 can have a raised region 194 on top of the recessed cavity 202 which contains the mounting hole 196 , such that the thickness of mounting plate 190 around the recessed cavity 202 is equal to the thickness of mounting plate 190 in the raised regions. The mounting leg 184 is substantially perpendicular to the mounting plate 190 and meet at a corner 186 . The rubber gasket 198 can have circular shape, or other shape that can fit sit inside the recessed cavity 202 . The furring strip 180 has an attachment hole 203 to secure a lath to the furring may be on the mounting leg 184 . The recessed cavity 202 embodiments can be utilized in other furring shapes, such as the ones depicted in FIG. 1 , FIG. 2 , FIG. 3 , and FIG. 4 .
[0086] FIG. 7 shows an illustration of a lath furring strip system 210 attached to a wall, which is comprised of sheathing 220 and framing 222 . The lath furring strip 214 is secured to the sheathing 220 and framing 222 via a screw 218 . In this embodiment, there is a channel screed 230 also secured to the sheathing 220 and framing 222 , via two screws 224 . A metal lath 212 is attached to the mounting leg 228 via a wire tie 226 . Between the furring strip 214 and the sheathing 220 is a moisture barrier 216 , such as building paper. This barrier runs the entire length under the furring strip 214 and channel screed 230 . The screws 218 , 224 pierce the moisture barrier 216 . The furring strip 214 can have the flexible elastic water resistive barrier embodiments of FIG. 1 , FIG. 5 , and FIG. 6 to protect water from seeping from the pierced moisture barrier 216 to the sheathing 220 and framing 222 . By securing the furring strip 214 with the screw 218 or other mounting device, the flexible elastic water resistive barrier squeezes into a shape where it fills in gaps in a mounting and prevents water from seeping to the sheathing 220 or framing 222 . In this embodiment of a lath and lath furring strip system, 210 a channel screed 230 creates a recessed reveal which offers an architectural accent while providing a control joint to help minimize cracking.
[0087] FIG. 8 is an illustration of a lath and lath furring strip system 240 where a furring strip 256 is secured to sheathing 246 and framing 248 via a mounting screw 260 .
[0088] This embodiment also has a termination stop called a J-channel stop 242 , such as Milcor, which provides for better water drainage. A lath 258 is attached to a mounting leg 254 of the furring strip 256 . The termination stop 242 is attached to the sheathing 246 and framing 248 via a mounting screw 244 . A moisture barrier 252 sits on the top side 242 of a termination stop 242 . The moisture barrier 252 is also situated between the lath furring strip 256 and the sheathing 246 and is penetrated by the screw 260 of the lath furring strip 256 . To prevent moisture from passing from the lath furring strip system 240 into the sheathing 246 or framing 248 , the bottom of the lath furring strip 256 can have a flexible elastic water resistive barrier, such as the ones described in the embodiments of FIG. 1 , FIG. 5 , and FIG. 6 .
[0089] FIG. 9 a and FIG. 9 b depict embodiments of an integrated lath furring strip weep screed 270 , and a lath furring strip weep screed 270 with an assembled lath and mounting device 290 . The lath furring strip weep screed 270 has a mounting leg 272 that has a profile height from the bottom of a second mounting plate 278 to the top of the mounting leg 272 of 0.365 inches or less. The mounting leg 272 has an attachment hole for attaching a lath 292 to the mounting leg 272 via an attachment device such as a wire tie 298 . The mounting leg 272 is substantially at a right angle to a first mounting plate 274 . A hairpin loop 276 bends the furring strip material substantially 180 degrees such that there is an extra layer of furring strip 270 material creating a second mounting plate 278 behind the first mounting plate 274 . A screw 288 or other mounting device secures the lath furring strip weep screed 270 into a wall or sheathing through both the first mounting plate 274 and second mounting plate 278 . A moisture barrier 294 , such as building paper, is placed between the lath and the furring strip mounting side 274 , which covers a hole created by the screw 288 or other mounting device, which secures the lath furring strip weep screed 270 to the wall. A moisture barrier 294 adheres to the top side of the first mounting plate 274 , which covers the screw 288 and top side of the first mounting plate 274 through an adhesive layer 296 which prevents water from seeping in between the lath 292 and the top side of the first mounting plate 274 . The second mounting plate 278 extends past the mounting leg 272 and angles toward the lath 292 and forms a first weep leg 280 . The first weep leg 280 is bent back at a point 284 to form a second weep screed leg 282 which also is angled to form a side 286 that sits flush with the wall. This allows water to drip from the plaster on the lath 292 away from the wall.
[0090] FIG. 10 a and FIG. 10 b depict embodiments of an integrated lath furring strip termination stop 300 , and a lath furring strip termination stop assembly 330 with a mounting device 316 and lath 322 . The lath furring strip termination stop 300 has a mounting leg 306 that has a profile height from the bottom of the second mounting plate 308 to the top of the mounting leg 306 of 0.365 inches or less. The mounting leg 306 has an attachment hole for attaching a lath 322 to the mounting leg 306 via an attachment device such as a wire tie 324 . The mounting leg 306 is substantially at a right angle to a first mounting plate 304 . A hairpin loop 302 bends the furring strip material substantially 180 degrees such that there is an extra layer of furring strip material which make the first mounting plate 304 and the second mounting plate 308 parallel to each other. A screw 316 or other mounting device secures the lath furring strip termination stop 300 into a wall or sheathing through both the furring strip mounting side 304 and termination stop mounting side 308 . A moisture barrier 320 adheres to the top side of the first mounting plate 304 , which covers the screw 288 and top side of the first mounting plate 304 through an adhesive layer 318 which prevents water from seeping in between the lath 322 and the top side of the first mounting plate 304 . The second mounting plate 278 extends past the mounting leg 272 and turns at substantially a right angle angles toward the lath 322 and forms a termination stop leg 310 . The termination stop leg 310 is bent at substantially a 90 degree angle to become parallel to the second mounting plate 308 . This allows water to drip from the plaster on the lath 292 away from the wall. This termination stop structure is used where the plastering of a wall ends and other material begins, and prevents water from seeping into a wall.
[0091] FIG. 11 a and FIG. 11 b depict embodiments of an integrated lath furring strip with a drip screed 340 , and a lath furring strip drip screed assembly 360 with a mounting device 362 and lath 358 . The lath furring strip drip screed 340 has a mounting leg 350 that has a profile height from the bottom of the second mounting plate 344 to the top of the mounting leg 350 of 0.365 inches or less. The mounting leg 350 has an attachment hole for attaching a lath 358 to the mounting leg 350 via an attachment device such as a wire tie 353 . The mounting leg 350 is substantially at a right angle to first mounting plate 352 . A hairpin loop 342 bends the furring strip material substantially 180 degrees such that there is an extra layer of furring strip material creating the second mounting plate 344 behind the first mounting plate 352 . A screw 362 or other mounting device secures the lath furring strip drip screed 340 into a wall or sheathing through both the first mounting plate 352 and second mounting plate 344 . A moisture barrier 356 , such as building paper, is placed between the lath 358 and the first mounting plate 352 , which covers a hole created by the screw 362 or other mounting device, which secures the lath furring strip 340 to the wall. The moisture barrier 356 adheres to the first mounting plate 352 by having an adhesive layer 354 . The second mounting plate 344 extends past the mounting leg 350 and angles toward the lath 358 and away from a wall, such that any water would fall down the drip screed leg 346 or off of an extension of that leg 348 away from the wall or window.
[0092] FIG. 12 a and FIG. 12 b depict an embodiment of a lath furring strip with a reveal 370 and an assembled lath furring strip with a reveal 390 . The assembled lath furring strip with a reveal includes an attached lath 386 and a moisture barrier 384 . The embodiment of the lath furring strip with a reveal 370 and assembled lath furring strip with a reveal 390 is integrated with decorative metal trim. It is this decorative metal trim which is commonly referred to as a reveal 383 . The lath furring strip with a reveal 370 , 390 , has two inner side protrusions 380 , 318 and two outer protrusions 378 , 379 which form two triangular-like shapes that form the reveal 383 and two furring strip sections 385 , 387 on each side of the reveal 383 . The outer protrusions 378 , 379 extend and form an obtuse angle with bottom mounting plates 376 , 377 (forming bottom mounting planes at the base of the bottom mounting plates 376 , 377 ) that may be placed against a wall framing that has a moisture barrier 384 . The bottom mounting plates 376 , 377 are bent into second mounting plates 374 , 375 on top of the bottom mounting plates 376 , 377 . Extending perpendicular from the top mounting plates 374 , 375 are mounting legs 372 , 373 which has attachment holes for securing lath 386 by way of a wire tie 388 or other mechanism that can attach lath 386 to a furring strip 370 , 390 . The height of the furring strip with a reveal 370 , 390 from the base of the furring strip 370 , 390 to the top of the mounting leg 388 is 0.365 inches or less so that the lath 386 can be consistently laid at ⅜ of an inch away from the framing. The furring strip with a reveal 370 , 390 is secured to the framing by fasteners that penetrate both the first mounting plate 376 , second mounting plate 374 , and moisture barrier 384 . The bottom mounting plates 376 , 377 are pressed against the moisture barrier 384 when secured to the framing via the screw or other mounting device. This pressure prevents moisture from seeping in from the plaster to through holes in the moisture 384 . The lath furring strip with a reveal 370 , 390 can have the added strength of a hemmed mounting leg 122 as shown in FIG. 4 b . Additionally, other embodiments featuring a furring strip with a reveal 370 , 390 can have the flexible water resistive barrier 6 as shown in FIG. 1 a , or 166 in FIG. 4 b , to further prevent seepage of water from plaster through holes created through the moisture barrier 384 by nails or screws that penetrate the moistures barrier 384 that hold the lath furring strip with a reveal 370 , 390 in place.
[0093] FIG. 13 a and FIG. 13 b depict a two-piece expansion joint 400 and an assembled two-piece expansion joint 440 with lath 416 , wire ties 432 , screws 418 , and moisture barrier 420 . Construction codes call for plaster-finished exteriors to have expansion joints at specific intervals allowing for the expansion and contraction of materials that occur during temperature changes throughout the day. In a first piece 411 , there is a bottom mounting plate 428 and a top mounting plate 430 . The top mounting plate 430 has a mounting leg 434 for attaching lath 416 to the mounting leg 434 with a wire tie 432 or other means for attachment. The top mounting plate 430 is substantially parallel to the bottom mounting plate 428 . The bottom mounting plate 428 , which at its base forms a bottom mounting plane, extends past the mounting leg 434 . The bottom mounting plate 428 is bent to then form an integral first overlapping plate 426 on top of the first mounting plate 428 . Extending perpendicular from the first overlapping plate 426 is a first joint-termination leg 424 , which extends beyond the plane of the top of the mounting leg 434 and beyond the lath 416 when assembled. Extending perpendicular to the first joint-termination leg 424 is a first overhanging leg 422 . The first expansion joint 411 can be placed at various distances from a second expansion joint 413 and the second expansion joint 413 is capable of sliding over the first expansion joint 411 . The second expansion joint 413 has a bottom mounting plate 410 , which at its base forms a bottom mounting plane. One on end of the bottom mounting plate 410 is a flashing 408 that rises and then forms the second expansion joint overlapping plate 406 . The flashing 408 provides a pre-tensioned bend in the metal to allow for a tighter seal against the first expansion joint 411 when a screw 418 secures the second expansion joint 413 to a wall or framing through a moisture barrier 420 . The second expansion joint 413 has a second overlapping plate 406 , which is substantially parallel to the first expansion joint overlapping plate 426 , such that the second expansion joint overlapping plate 406 lays on top of the first expansion joint overlapping plate 426 when assembled together to form the two-piece expansion joint 400 , 440 . Extending substantially perpendicular from the second expansion joint overlapping plate 406 is a second expansion joint termination leg 404 . Extending substantially perpendicular from the second expansion joint termination leg 404 is a second overhanging leg 402 . The first overhanging leg 422 and second overhanging leg 402 are substantially in the same plane as each other. The space between the first termination leg 424 and second termination leg 404 can expand or contract when the temperature changes. The second overlapping plate 406 can slide back and forth over the first overlapping plate 426 when the temperature changes. The second expansion joint 410 has an top mounting plate 412 on of its bottom mounting plate 12 . Extending perpendicular from the top mounting plate 412 is a second mounting leg 432 , where lath 416 is attached through a hole on the mounting leg 414 . Both the first expansion joint 411 and second expansion joint 413 secured to a wall or framing by penetrating the top and bottom mounting plates 430 , 428 , 412 , 413 of each expansion joint 411 , 410 to a wall of framing via a screw 418 or other mounting device. The first expansion joint 411 and the second expansion joint 413 can have the added strength of a hemmed mounting leg 122 as shown in FIG. 4 b . Additionally, other embodiments featuring a two piece expansion joint 400 , 440 can have the flexible water resistive barrier 6 as shown in FIG. 1 a , or 166 in FIG. 4 b , to further prevent seepage of water from plaster through holes created through the moisture barrier 420 by the screws 418 that penetrate the moisture barrier 420 that hold two-piece expansion joint 400 , 440 to the wall or framing. The height of the first expansion joint 411 and the second expansion joint 413 from the base of each expansion joint 411 , 413 to the top of each mounting leg 434 , 414 is 0.365 inches or less so that the lath 416 can be consistently laid at ⅜ of an inch away from the framing.
[0094] FIG. 14 a and FIG. 14 b depict a window lath furring strip 450 and an assembled window lath furring strip 470 assembled with a lath 468 , wire tie 466 , moisture barrier 464 , over a window flange 463 of a window 462 . The lath furring strip 450 , 470 has a bottom mounting plate 456 and an integral top mounting plate 458 . A bottom mounting plane is formed at the base of the bottom mounting plate 456 . Extending from the top mounting plate 458 is a mounting leg 460 where lath 468 attaches to the mounting leg 460 via a wire tie 466 . Extending from the bottom mounting plate 456 , beyond the mounting leg 460 is a flare 454 designed to have a pre-tensioned shape in the metal to allow the furring strip 450 to seal tightly against the window flange 463 when a screw 472 penetrates through the top mounting plate 458 and the bottom mounting plate 456 into a wall or framing. This creates a tight seal between the lath furring strip 450 and the window flange 463 , which prevents moisture that may gather around the window 462 from seeping from the plaster on the lath 668 into the wall. A moisture barrier 464 is installed on top of the head of the screw 474 , on the top mounting plate 458 to eliminate any moisture barrier penetration from plaster to the wall created by the penetration of the screw 472 into the top mounting plate 458 , and bottom mounting plate 456 into the wall. The furring strip 450 , 470 can have the added strength of a hemmed mounting leg 122 as shown in FIG. 4 b . Additionally, other embodiments featuring a window furring strip 400 can have the flexible water resistive barrier 6 as shown in FIG. 1 a , or 166 in FIG. 4 b , to further prevent seepage of water from plaster through holes created by a screw 472 . The height of the window furring strip 450 , 470 from the bottom mounting plate 456 to the plane formed by the top of the mounting leg 460 is 0.365 inches or less so that the lath 468 can be consistently laid at ⅜ of an inch away from the framing.
[0095] FIG. 15 a and FIG. 15 b depict embodiments of an integrated lath furring strip weep screed 480 , and a lath furring strip weep screed 480 with an assembled lath and mounting device 500 and foam insulation 502 . The lath furring strip weep screed 480 has a mounting leg 488 . The mounting leg 272 has an attachment hole (see FIG. 18 for location of an attachment hole 636 on a mounting leg 638 ). The attachment hole is used for attaching a lath 508 to the mounting leg 488 via an attachment device such as a wire tie 504 . The mounting leg 488 is substantially perpendicular to a top mounting plate 486 having an exterior side 487 . A loop 484 bends the furring strip material substantially 180 degrees such that there is a bottom mounting plate 482 having an interior side 483 that sites flush against the wall 512 and is parallel to the top mounting plate 486 leaving a gap 489 between the top mounting plate 486 and bottom mounting plate 482 . A screw 510 or other mounting device secures the lath furring strip weep screed 480 into a wall or sheathing 512 through both the bottom mounting plate 482 and the top mounting plate 486 . A moisture barrier 498 , such as building paper, is placed between the foam 502 and the exterior side 487 of top mounting plate 486 , which covers a hole created by the screw 510 or other mounting device, which secures the lath furring strip 480 to the wall 512 . The moisture barrier 498 is placed on top of the head of a screw 510 and the exterior side 487 of the top mounting plate 482 to eliminate any moisture penetration from the plaster to the wall 512 . The moisture barrier 498 adheres to the top mop mounting plate 486 via an adhesive layer 506 to the exterior side 487 of the top mounting plate 486 . The bottom mounting plate 482 extends past the mounting leg 488 and is angled to form a first weep screed leg 490 . The first weep screed leg 490 is bent at a point 492 to form a second weep screed leg 494 , which is angled to form a weep screed extension 496 that sits flush with the wall 512 . This allows water to drip from the plaster on the lath 508 away from the wall that has penetrations. When the assembled, the lath furring strip weep screed 500 has a layer of insulation 502 in between the lath furring strip 480 and the lath 508 . The insulation layer 502 sits on the exterior side 487 of the top mounting plate 486 , which has a moisture barrier 498 between the insulation layer 502 and the exterior side 487 . From the top of the insulation layer 502 (where the attachment hole is located on the mounting leg 488 ), to the top of the mounting leg 491 may be 0.365 inches for less, so that the distance from the plaster on the lath 508 to the insulation layer 502 is not greater than 0.365 inches, for proper keying of the plaster.
[0096] FIG. 16 a and FIG. 16 b depict embodiments of an integrated lath furring strip with a drip screed 520 , and an assembled lath furring strip 550 integrated with a mounting device 542 , lath 544 , and insulation layer 540 , on a wall 536 . The lath furring strip drip screed 520 has a mounting leg 528 , a top mounting plate 526 with an exterior side 527 , a bottom mounting plate 522 with an interior side 523 that lays flush against a wall 536 . There is a gap 529 between the bottom mounting plate 522 and top mounting plate 526 . The mounting leg 528 has an attachment hole (see FIG. 18 for location of an attachment hole 636 on a mounting leg 638 ). The lath 544 is secured to the mounting leg 528 via a wire tie 546 or other attachment device. An insulation layer 540 is placed between the lath 546 and the lath furring strip 520 . The mounting leg 528 is substantially at a right angle to the top mounting plate 526 . A loop 524 bends the furring strip material substantially 180 degrees such that there is a second layer of furring strip material creating the bottom mounting plate 522 . A screw 542 or other mounting device secures the lath furring strip drip screed 520 , 550 into a wall or sheathing 536 through both the top mounting plate 526 and the bottom mounting plate 522 . A moisture barrier 538 , such as building paper, is placed between the foam insulation 540 and the top mounting plate 526 . The moisture barrier 538 is installed on top of the head of the screw 542 or other mounting device, which secures the lath furring strip 520 to the wall 536 . This placement eliminates any moisture barrier penetration from plaster to the wall 536 created by the penetration of the screw 542 into the top mounting plate 526 . The moisture barrier 538 adheres to the top mounting plate 526 by having an adhesive layer 529 . The bottom mounting plate 522 extends past the mounting leg 528 at an obtuse angle from the bottom mounting plate 522 , such that any water would fall down the drip screed leg 530 . From the top of the insulation layer 540 (where the attachment hole is located on the mounting leg 528 ) to the top edge 531 of the mounting leg 528 is 0.365 inches so there is proper keying of plaster. The drip screed leg 530 may have a drip screed leg extension 532 or an additional angled extension 534 to further allow water to drip away from a wall 536 .
[0097] FIG. 17 a and FIG. 17 b depict embodiments of an integrated lath furring strip termination stop 560 , and a lath furring strip termination stop assembly 590 with a mounting device 581 and lath 580 . The lath furring strip termination stop 560 has a bottom mounting plate 562 having an interior side 663 that is positioned flush against a wall 576 , a top mounting plate 578 having an exterior side 567 where a moisture barrier 575 and insulation layer 574 can be positioned, and mounting leg 568 having a top edge 571 , and a gap 569 between the top mounting plate 566 and bottom mounting plate 562 . The mounting leg 568 has an attachment hole for attaching a lath 580 to the mounting leg 568 via an attachment device such as a wire tie 582 (see FIG. 18 for location of an attachment hole 636 on a mounting leg 638 ). The mounting leg 568 is substantially at a right angle to a bottom mounting plate 562 . The distance from the top of the insulation layer 574 to the top edge 571 of the mounting leg 568 not greater than 0.365 inches in ensure proper keying of the plaster. theA loop 564 bends the furring strip material substantially 180 degrees such that there is a second layer of furring strip material which forms the top mounting plate 566 , which is substantially parallel to a bottom mounting plate 562 . A screw 581 or other mounting device secures the lath furring strip termination stop 560 onto a wall or sheathing 576 through both the furring top mounting plate 566 and bottom mounting plate 562 . A moisture barrier 576 is installed such that it is placed on top of the head of the screw 581 and the top mounting plate 566 to eliminate any moisture barrier penetration from plaster to the wall 576 created by the penetration of the screw 581 into the top mounting plate 566 , and bottom mounting plate 562 into the wall 576 . The moisture barrier 576 adheres to the exterior of the top mounting plate 566 via an adhesive layer 578 , which prevents water from seeping in between the lath 580 or insulation layer 574 and the top mounting plate 566 . The bottom mounting plate 562 extends past the mounting leg 568 and forms a termination leg 570 substantially perpendicular to the bottom mounting plate 562 and parallel to the mounting leg 568 . The termination leg 570 has a termination leg extension 572 substantially perpendicular to the termination leg 570 . This allows water to drip from the plaster on the lath 580 away from the wall 576 . This termination stop structure is used where the plastering of a wall ends and other material begins, and prevents water from seeping into a wall 576 . An insulation layer 574 is positioned on top of the exterior side of the top mounting plate 566 , and has a moisture barrier 575 between the insulation layer 574 and the top mounting plate 566 .
[0098] FIG. 18 a and FIG. 18 b and FIG. 18 c illustrate three views of a furring strip 600 having a recessed groove 616 for a rubber gasket 618 , and an assembled lath furring strip 640 secured to a wall 620 and frame 624 having an insulation layer 628 . The recessed groove 616 allows a flexible elastic water resistive barrier, such as a rubber gasket 618 to line a mounting hole 614 without increasing the overall height of the furring strip 600 . The recessed groove 616 is within the interior side 612 of the mounting plate 610 . A raised region 606 on the exterior side 608 of the mounting plate 610 has a mounting hole 614 . The lath furring strip 600 can be secured to the wall via a screw 622 . The recessed groove 616 can have a variety of shapes that enable it to fit a rubber gasket 618 . A mounting leg 604 having a top vertical edge 602 is substantially perpendicular to the mounting plate 610 and has an attachment hole 636 for attaching lath 630 via a tie 632 or other attachment device. When assembled, there is a water resistive barrier 626 , such as building paper, contacting the interior side of the mounting plate 612 and the wall 620 . A screw 622 or other securing device penetrates the rubber basket 618 , wall 620 , and framing 624 . An insulation layer 628 is layered between the lath 630 and the exterior side of the mounting plate 610 . In order to achieve the proper spacing between the insulation layer 628 and lath 630 , the distance from the top of the insulation layer 628 (where the attachment hole 636 on the mounting leg 604 is located) to the top vertical edge 602 of the mounting leg 602 is not greater than 0.365 inches. However the height of the mounting leg 604 height can vary in size in different embodiments to accommodate different thicknesses of insulation layers 628 .
[0099] FIG. 19 a and FIG. 19 b depict an embodiment of an outside corner lath furring strip 650 and an assembled outside corner lath furring strip 680 with insulation 662 secured to a wall 664 and framing 666 via a screw 668 . The furring strip 650 has a first mounting plate 658 with an interior side 661 and an exterior side 663 , and a second mounting plate 660 with an interior side 665 and exterior side 667 . The first mounting plate 658 and second mounting plate 660 are substantially perpendicular to each other and fit around an outside corner of a wall 664 and lay substantially flush against the wall 664 . Integral with the first mounting plate 658 and second mounting plate 660 are a first mounting leg 652 and a second mounting leg 656 that are parallel to each other and connected through a top edge bend 654 in the furring strip 650 . Each mounting leg 652 , 656 has an attachment hole (see FIG. 18 for location of an attachment hole 636 on a mounting leg 638 ), where lath 663 is attached to the furring strip via a wire tie 674 . Between the lath 663 and the mounting plates 658 , 660 and insulation layer 662 is placed. A moisture barrier 670 is placed on the exterior sides 663 , 667 each mounting plate 658 , 660 covering of the head of the screw 668 to eliminate any moisture barrier penetration from plaster to the wall 664 created by the penetration of the screw 668 into the mounting plate 658 into the wall 664 . The moisture barrier 670 attaches to the mounting plates 658 , 660 via an adhesive layer 672 . In order to achieve the proper spacing between the insulating layer 665 and the plaster or lath 663 , the distance from the top of the insulation layer 662 (where the attachment hole on the mounting legs 652 , 656 are located) to the top edge bend 654 connecting the two mounting legs 652 , 656 is not greater than 0.365 inches, however the height of the mounting legs 652 , 656 can vary in length in order accommodate different thicknesses of insulation layers 662 .
[0100] FIG. 20 a and FIG. 20 b depict embodiments of a window furring strip 690 and an assembled furring strip 720 with a lath 706 , mounting device 714 , and an insulation layer 710 . The window furring strip 690 has a bottom mounting plate 696 having and interior side 703 that sites flush against a wall, a top mounting plate 698 having an exterior side 699 where a moisture barrier 712 and insulation layer 710 can be placed, and mounting leg 700 having a top vertical edge 705 . The mounting leg 700 has an attachment hole (see FIG. 18 for location of an attachment hole 636 on a mounting leg 638 ). The attachment hole is used for attaching a lath 706 to the mounting leg 700 via an attachment device such as a wire tie 708 . The mounting leg 700 is substantially at a right angle to a bottom mounting plate 696 . A top mounting plate 698 is integral and substantially parallel to the bottom mounting plate 696 and has a gap 701 between the two plates 696 , 698 . A screw 714 or other mounting device secures the window furring strip 690 a wall or sheathing through both the bottom mounting plate 696 and the top mounting plate 698 . A moisture barrier 712 , such as building paper, is placed between the insulation layer 710 and the top mounting plate 698 , which covers a hole created by the screw 510 or other mounting device. The moisture barrier 712 adheres to the exterior side 699 of the top mounting plate 698 , which covers the screw 510 and exterior side 698 of the top mounting plate 486 via an adhesive layer 627 . The moisture barrier 712 prevents water from seeping in from between the insulation layer 710 and the top mounting plate 698 . Extending from the top mounting plate 698 is a mounting leg 700 where lath 706 attaches to the mounting leg 702 via a wire tie 708 . Extending from the bottom mounting plate 696 is a flared plate 694 designed to have a pre-tensioned shape in the metal to allow the furring strip 690 to seal tightly against the window flange 702 on a window frame 704 when a screw 714 penetrates through the top mounting plate 698 and the bottom mounting plate 696 . This assembly creates a tight seal between the lath furring strip 690 and the window flange 702 , which prevents moisture that may gather around the window 704 from seeping from the plaster on the lath 706 into the wall. In order to achieve the proper spacing between the insulating layer 710 and the plaster or lath 706 , the distance from the top of the insulation layer 710 (where the attachment hole of the mounting leg 700 is located) to the top edge 705 of the mounting leg 700 is not greater than 0.365 inches to ensure proper keying of the plaster, however the height of the mounting leg 700 can vary in size in different embodiments in order accommodate different thicknesses of insulation layers 710 .
[0101] The invention has been described in terms of preferred embodiments thereof, but is more broadly applicable as will be understood by those skilled in the art. The scope of the invention is only limited by the scope of the following claims and equivalents thereof. | The present invention provides a lath furring strip having improved water-resistant and insulation features. The lath furring strip has portions of the mounting leg height not exceeding 0.365 inches for proper plastering of a wall. The lath furring strip is integrated into other architectural structures such as reveals, expansion joints and window flange coverings. By integrating these structures with a lath furring strip having water proofing features, there is increased water proofing of the entire architectural structure. One or more moisture barriers can easily be applied to the wall or furring strips that prevents seepage of moisture from the stucco on the lath to a wall or framing. By using an improved lath furring strip, fewer penetrations are needed to secure the furring strip to a wall compared to securing a lath directly to a wall. | 4 |
FIELD OF THE INVENTION
The present invention relates generally to fluid handling apparatus and, more particularly, to direct response valves of reciprocating type.
BACKGROUND OF THE INVENTION
It is not uncommon for subterranean reservoir rocks to be fully saturated with oil and gas yet be of such low permeability that they are not feasible to develop in an economic manner. In such cases, production rates are often boosted by resorting to hydraulic fracturing, a technique that increases rock permeability by opening channels through which reservoir fluids can flow to recovery wells. During hydraulic fracturing, a fluid such as water is pumped into the earth under extremely high pressure where it enters a reservoir rock and fractures it. Sand grains, aluminum pellets, glass beads, or other proppants are carried in suspension by the fluid into the fractures. When the pressure is released at the surface, the fractures partially close on the proppants, leaving channels for oil and gas to flow to recovery wells.
Specialized pumps are used to develop the pressures necessary to complete a hydraulic fracturing procedure or “frac job.” These pumps are usually provided with so-called fluid ends within which reciprocating plungers place fluids under pressure. Suction and discharge valves control fluid flow to and from the plungers. Improperly locating a valve in the fluid end at the time of manufacture can greatly weaken the fluid end, leading to a catastrophic pump failure. Similarly, a valve that has too many projections can capture or “knock out” enough proppant to block the flow of fluid through a pump requiring, at a minimum, that time and effort be invested to clear the blockage—a costly undertaking in an oilfield environment.
Commonly used discharge valves possess a plurality of guides or “wings” that protrude into a valve seat to hold a piston in place. These wings are known to capture proppant from a fracture fluid under certain operating conditions. Such conditions should, however, be virtually nonexistent.
SUMMARY OF THE INVENTION
In light of the problems associated with fluid ends of pumps used for hydraulic fracturing, it is a principal object of the invention to provide a discharge valve that reduces the likelihood of proppant being knocked out of suspension to create a blockage. The discharge valve of the present invention, thus, offers few impediments (none whatsoever in a pumping chamber of a fluid end) to flow through a fluid end when open so that fracturing fluids can flow smoothly through it. As a result, fracturing fluids with higher than normal concentrations of suspended proppants can be pumped with substantial cost savings to the user.
It is an additional object of the invention to provide a discharge valve of the type described that, because of its compact size, can be positioned close to the suction valve that it may be paired with permitting faster transit times for a fluid through a pumping chamber and greater efficiencies in the operation of a pump.
It is another object of the invention to provide a discharge valve of the type described that can be seated in a relatively shallow pocket in a fluid end. As is well known, a valve pocket of shallow depth requires that less load-bearing material be removed from the body of a fluid end thereby enhancing the strength and durability of a fluid end. It is less likely, then, that a fluid end configured to receive the discharge valve of the present invention will fail from the development of excessive internal loads and stresses.
It is a further object of the invention to provide a discharge valve of the type described that utilizes a valve seat that abuts its supporting surface, i.e., a seat deck, at a shallow incline rather than at right angles as is common. A slope of about 30° has been found to significantly reduce zones of stress transmitted through a fluid end. It is along such stress zones that fluid ends have been known to crack and fail under load.
Still another object of the invention is to provide a discharge valve of the type described that includes special porting to reduce the likelihood that the valve will become stuck in either an open position or a closed position during use. Therefore, the valve is virtually failsafe.
It is an object of the invention to provide improved elements and arrangements thereof in a discharge valve for the purposes described which is lightweight in construction, inexpensive to manufacture, and dependable in use.
Briefly, the discharge valve in accordance with this invention achieves the intended objects by featuring a valve seat and a piston with a bottom surface that is convex across its entirety for engaging the valve seat. The piston has a stem that extends upwardly from the head away from the valve seat and into a socket in a valve guide. The socket is formed in a conical prop projecting downwardly from a disc-like plug. A number of apertures traverse the plug and intersect the socket to providing pressure relief to the socket. A compressed spring is disposed between the valve guide and the head for normally retaining the head in engagement with the valve seat.
The foregoing and other objects, features and advantages of the present invention will become readily apparent upon further review of the following detailed description of the preferred embodiment as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention may be more readily described with reference to the accompanying drawings, in which:
FIG. 1 is a side elevational view of a discharge valve in accordance with the present invention with portions broken away to reveal details thereof.
FIG. 2 is a cross-sectional view taken along line 2 — 2 of FIG. 1 .
Similar reference characters denote corresponding features consistently throughout the accompanying drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the FIGS., a discharge valve in accordance with the present invention is shown at 10 . Valve 10 includes a valve seat 12 for positioning in a discharge passage 14 of a fluid end 16 and a reciprocating piston 18 for controlling the flow of fluid through passage 14 . Piston 18 has a head 20 for engaging the top surface 22 of seat 12 and a stem 24 extending upwardly from head 20 . Stem 24 is slidably positioned in a close-fitting socket 26 in a valve guide 28 positioned above valve seat 12 in passage 14 . A number of apertures 30 connect the inner end of socket 26 with passage 14 to prevent piston 18 from becoming stuck in a raised or open position. A compressed spring 32 is disposed between the valve guide 28 and head 20 to normally retain head 20 in engagement with valve seat 12 .
Valve seat 12 is a hollow cylinder or tube with top and bottom surfaces 22 and 34 that are shaped to reduce turbulence. As shown, top surface 22 is beveled such that it slopes downwardly and inwardly toward the center of seat 12 at an angle of about 30°. Bottom surface 34 , however, slopes upwardly and inwardly at an incline that increases evenly from the outer wall 36 of seat 12 to the inner wall 38 thereof. Thus, bottom surface 34 is rounded.
Extending outwardly from the top of outer wall 36 of valve seat 12 is a peripheral flange 40 . The bottom of flange 40 slopes downwardly and inwardly toward outer wall 36 at an angle of approximately 30°. This angle corresponds with that of a seat deck 42 in fluid end 16 that surrounds passage 14 thereby ensuring the formation of a strong platform for seat 12 capable of reducing the transmission of stresses to fluid end 16 . To ensure against fluid leaks around seat 12 , outer wall 36 is provided with a pair of peripheral grooves beneath flange 40 within which are positioned O-ring seals 44 and 46 for engaging fluid end 16 .
Head 20 of piston 18 has a convex, bottom surface 48 that curves downward like the surface of a sphere, a planar top surface 50 and a circular, peripheral surface 52 that joins bottom and top surfaces 48 and 50 together. Bottom surface 48 is adapted to snugly engage top surface 22 of seat 12 . About the periphery of bottom surface 48 is a band or insert 54 formed of hard plastic that may also engage top surface 50 and serve as seal. Insert 54 has a cross-section resembling an inverted “L” with an upper, horizontal leg 56 from which a vertical leg 58 extends downwardly. A peripheral channel 60 with a corresponding, inverted “L” shape is provided in surface 52 to receive and retain insert 54 .
Top surface 50 of head 20 includes a shallow recess 62 about the base of stem 24 Recess 62 is provided to reduce the weight of piston 18 so that it can rapidly respond to fluid pressure changes in passage 14 . Also, recess 62 serves as an abutment for the bottom of spring 32 . A step or shoulder 64 rising from the bottom of recess 62 around step 24 insures that the bottom of spring 32 cannot shift in position and become lodged against the bottom of valve guide 28 .
Valve guide 28 includes a disc-shaped plug 66 having a circular, side wall 68 and a circumferential flange 70 projecting outwardly from the top of side wall 68 . Flange 70 engages a seat deck 72 in fluid end 16 surrounding passage 14 . Since guide 28 transmits significantly smaller loads to fluid end 16 , it is not necessary that seat deck 72 be sloped like seat deck 42 . To prevent fluid leaks around plug 66 , side wall 68 is provided with a pair of peripheral grooves beneath flange 70 within which are positioned O-ring seals 74 and 76 for engaging fluid end 16 .
A conical prop 78 is integrally formed with plug 66 and has an exterior diameter that decreases gradually from its top, at plug 66 , to its bottom, remote from plug 66 . As shown, prop 78 extends downwardly from the center of plug 66 to provide an abutment for head 20 of piston 18 . Socket 26 extends upwardly through the center of prop 78 and partially through plug 66 . The base of prop 78 is provided with a peripheral ledge or step 80 that provides a surface through which apertures 30 may penetrate to access to the inner end of socket 26 and, in acting as an abutment for spring 32 , keeps the top of spring 32 from blocking apertures 30 . Preferably, guide 28 is provided with six apertures 30 that extend radially outward from socket 26 at even intervals of 60° so that if one aperture 30 happens to become blocked the others can serve as backups.
Projecting from the top of plug 66 is a sleeve 82 with interiorly threaded socket 84 . Sleeve 82 is used in a conventional manner to lift guide 28 from passage 14 when it is desired to service valve 10 .
From the foregoing, it should be appreciated that use of valve 10 is straightforward. After installation of valve 10 in fluid end 16 , a plunger (not shown) is reciprocated beneath seat 12 . As the plunger moves forward to drive fluid through seat 12 , the compressive force of spring 32 is overcome and piston 18 is elevated to the position shown in FIG. 1 . With head 20 being disengaged from seat 12 , fluid flows smoothly through valve 10 and out port 86 in fluid communication with passage 14 . When the plunger travels back to its starting point, a partial vacuum is created within seat 12 that permits the compressive force of spring 32 to drive concave bottom surface 48 and insert 54 into the top surface 22 of seat 12 thereby preventing fluid in port 86 or passage 14 to travel back through valve 10 toward the plunger.
The process of opening and closing valve 10 is entirely automatic and requires mere fractions of a second to accomplish. Since the valve 10 minimizes turbulent flow, there is little likelihood that proppant will be captured by valve 10 to block flow through passage 14 under normal conditions of use. It has been found that the resistance of valve 10 to knocking out proppant is so great that fluids containing greater proppant loads than those normally pumped can be delivered through valve 10 providing great cost savings.
While the invention has been described with a high degree of particularity, it will be appreciated by those skilled in the art that modifications may be made thereto. Therefore, it is to be understood that the present invention is not limited to the sole embodiment described above, but encompasses any and all embodiments within the scope of the following claims. | A discharge valve including a valve seat and a piston having a head with a bottom surface that is convex across its entirety for engaging the valve seat. The piston has a stem extending upwardly from the head away from the valve seat. A valve guide has a socket for slidably receiving the stem of the piston and a number of apertures intersecting the socket for providing pressure relief thereto. A compressed spring is disposed between the valve guide and the head for normally retaining the piston in engagement with the valve seat. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2007-338047, filed on Dec. 27, 2007, the entire contents of which are incorporated herein by reference.
BACKGROUND
Enhancement of carrier (electron and hole) mobility is an important factor for high performance of a transistor. Since an impurity present in a channel causes deterioration of the carrier mobility, it is necessary to form a channel region while preventing impurity diffusion into a surface of a silicon substrate. It is thus well known that a channel structure having a steep impurity concentration gradient is desirable to improve transistor characteristics.
Accordingly, there is a method in which a channel structure having a steep impurity concentration gradient is formed by forming a non-doped silicon epitaxial layer after forming an impurity channel layer by ion implantation.
In this structure, an impurity in the impurity channel layer is diffused from the impurity channel layer into the non-doped silicon epitaxial layer, which causes that a channel profile is moderated. Therefore, since a SiC layer suppresses the diffusion of the impurity (e.g., disclosed in JP-A-2000-77654), it is suggested that, after forming an impurity channel layer by ion implantation, an SiC layer is epitaxially grown on the impurity channel layer and a non-doped silicon epitaxial layer is formed thereon (e.g., disclosed in a non-patent literary document of T. Ernst et al. “2003 Symposium on VLSI Technology Digest of Technical Papers” pp. 51-52).
However, in this structure, there is a problem in that junction capacitance and junction leakage are increased since an impurity diffuses downwards from the impurity channel layer and an impurity concentration at an interface between a well region and a high concentration diffusion layer region and an interface between a channel region and the high concentration diffusion layer region is increased.
BRIEF SUMMARY
A semiconductor device according to one embodiment includes: a semiconductor substrate; a first impurity diffusion suppression layer formed on the semiconductor substrate for suppressing diffusion of a channel impurity; an impurity channel layer formed on the first impurity diffusion suppression layer and containing the channel impurity; a second impurity diffusion suppression layer formed on the impurity channel layer for suppressing diffusion of the channel impurity; a channel layer formed on the second impurity diffusion suppression layer; a gate insulating film formed on the channel layer; and a gate electrode formed on the gate insulating film.
A semiconductor device according to another embodiment includes: a semiconductor substrate having an nMOS region and a pMOS region; a lower impurity diffusion suppression layer formed on the semiconductor substrate in the nMOS region for suppressing diffusion of a p-type channel impurity; a first impurity channel layer formed on the lower impurity diffusion suppression layer and containing the p-type channel impurity; a second impurity channel layer formed on the semiconductor substrate in the pMOS region and containing an n-type channel impurity; an upper impurity diffusion suppression layer formed on the first impurity channel layer and comprising a crystal that suppresses diffusion of the p-type channel impurity; a first channel layer formed on the upper impurity diffusion suppression layer; a second channel layer formed on the second impurity channel layer and comprising the crystal; and gate electrodes each formed on the first and second channel layers via gate insulating films.
A method of fabricating a semiconductor device according to another embodiment includes: forming a lower impurity diffusion suppression layer on an nMOS region of a semiconductor substrate for suppressing diffusion of a p-type channel impurity; forming a first impurity channel layer on the lower impurity diffusion suppression layer, the first impurity channel layer containing the p-type channel impurity; forming a second impurity channel layer on a pMOS region of the semiconductor substrate, the second impurity channel layer containing an n-type channel impurity; simultaneously epitaxially growing first and second SiGe crystals on the first and second impurity channel layers, the first and second SiGe crystals suppressing diffusion of the p-type channel impurity; simultaneously epitaxially growing first and second Si crystals on the first and second SiGe crystals; diffusing Ge in the second SiGe crystal into the second Si crystal by heat treatment for forming a third SiGe crystal comprising the Ge-diffused second Si crystal and the second SiGe crystal; and forming gate electrodes each on the first Si crystal and third SiGe crystal via gate insulating films.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross sectional view showing a semiconductor device in a first embodiment;
FIGS. 2A to 2E are cross sectional views schematically showing a portion of a method of fabricating the semiconductor device in the first embodiment;
FIGS. 3A and 3B are graphs showing impurity concentrations in the first embodiment;
FIG. 4 is a cross sectional view showing a semiconductor device in a second embodiment; and
FIGS. 5A to 5E are cross sectional views schematically showing a portion of a method of fabricating the semiconductor device in the second embodiment.
DETAILED DESCRIPTION
First to third embodiments will be described in detail hereinafter with reference to the accompany drawings.
First Embodiment
FIG. 1 is a cross sectional view in a channel length direction showing a semiconductor device in a first embodiment.
An element isolation portion 2 having a depth of 200-350 nm is formed on a p-type or n-type silicon substrate 1 . A p-type well region (not shown) is formed in an active element portion that is a region on the silicon substrate 1 divided by the element isolation portion 2 . In case that the p-type well region is formed by implanting B ion into the silicon substrate 1 , a typical implantation condition of B ion for forming the p-type well region is about 260 keV of acceleration voltage and 2×10 13 cm −2 of dosage.
A SiC layer as a first impurity diffusion suppression layer 3 is provided 5-20 nm in thickness in a nMOS region on the silicon substrate 1 , and a B-doped or In-doped Si layer as an impurity channel layer 5 are formed 10-30 nm in thickness on the SiC layer 3 .
A SiC layer as a second impurity diffusion suppression layer 4 is provided 5-20 nm in thickness on the impurity channel layer 5 and a non-doped silicon epitaxial layer 6 is formed 5-20 nm in thickness on the second impurity diffusion suppression layer 4 . By forming the SiC layers as the first impurity diffusion suppression layer 3 and the second impurity diffusion suppression layer 4 so that a carbon atom concentration is 1×10 17 cm −3 or more, it is possible to effectively suppress diffusion of an impurity such as B or In, etc., from the impurity channel layer 5 into the silicon substrate 1 and the silicon epitaxial layer 6 . And then, a shallow diffusion layer 9 and a deep diffusion layer 11 are formed spanning any of the silicon epitaxial layer 6 , the first impurity diffusion suppression layer 3 , the second impurity diffusion suppression layer 4 , the impurity channel layer 5 and the silicon substrate 1 , or plural layers thereof.
A gate electrode 8 is formed on the silicon epitaxial layer 6 via a gate insulating film 7 and a gate sidewall film 10 is formed on a side surface of a laminate structure composed of the gate insulating film 7 and the gate electrode 8 . Then, a silicide layer 12 is formed on the gate electrode 8 and the silicon epitaxial layer 6 .
Besides a silicon dioxide film, a silicon oxynitride film or a silicon nitride film, etc., the gate insulating film 7 is formed of, e.g., a hafnium silicon oxynitride film (HfSiON) or a hafnium silicate film (HfSiO), etc., having a permittivity higher than that of the silicon dioxide film or the silicon oxynitride film, or a laminated structure thereof. The gate electrode 8 is composed of, e.g., a conductor such as polysilicon, etc., or a metal electrode such as tungsten (W) or titanium nitride (TiN), etc. The silicide layer 12 may be formed of, e.g., Ni-silicide, Co-silicide, Er-silicide, Pt-silicide or Pd-silicide, etc.
FIGS. 2A to 2E are cross sectional views showing processes for forming the semiconductor device in the first embodiment.
Firstly, the element isolation portion 2 is formed on a main surface of the silicon substrate 1 using, e.g., a hard mask such as SiN, etc.
Next, as shown in FIG. 2A , after forming a well region (not shown) in the active element portion divided by the element isolation portion 2 on the main surface of the silicon substrate 1 , a SiC layer as the first impurity diffusion suppression layer 3 is formed on the silicon substrate 1 by epitaxially growing a SiC crystal to a thickness of 5-20 nm.
Silicon is epitaxially grown by heating the silicon substrate 1 in a hydrogen atmosphere at a high temperature of 700° C. or more and supplying reaction gas such as SiH 4 , SiH 2 Cl 2 , SiHCl 3 or HCl, etc., on the silicon substrate 1 together with hydrogen, and the SiC layer 3 is formed by supplying the above-mentioned reaction gas mixed with SiH 3 CH 3 . It is possible to effectively suppress diffusion of an impurity from the impurity channel layer 5 into the silicon substrate 1 by forming the SiC layer 3 so that an atomic percentage (Atomic %) of carbon is 0.05-3.0%.
Next, as shown in FIG. 2B , a B-doped or In-doped Si layer, that becomes the impurity channel layer 5 , is formed on the SiC layer 3 by epitaxially growing a Si crystal to a thickness of 10-30 nm. It is possible to form the B-doped Si layer 5 by mixing B 2 H 6 with the above-mentioned reaction gas and growing the silicon. After this, a SiC layer as the second impurity diffusion suppression layer 4 is formed on the Si layer 5 by epitaxially growing a SiC crystal.
Following this, as shown in FIG. 2C , after a non-doped Si layer used as the silicon epitaxial layer 6 , which is a channel layer, is formed 5-20 nm in thickness, RTA (Rapid Thermal Annealing) is conducted for channel activation.
Next, as shown in FIG. 2D , the gate insulating film 7 is formed about 0.5-6 nm in thickness on the silicon epitaxial layer 6 by a thermal oxidation method or a LPCVD (Low Pressure Chemical Vapor Deposition) method. On the gate insulating film 7 , an about 50-200 nm thick gate electrode 8 is formed of, e.g., polysilicon or polysilicon germanium. After forming the gate electrode 8 , the gate electrode 8 and the gate insulating film 7 are patterned using a lithographic method and a reactive ion etching method, etc.
Next, the shallow diffusion layer 9 is formed by ion implantation. After conducting B ion implantation under the condition of, e.g., 20 keV of acceleration voltage and 1×10 13 -3×10 13 cm −2 of dosage (30-60 degrees of tilt) as a HALO implantation condition, an As ion is implanted under the condition of 1-5 keV of acceleration voltage and 5×10 14 -1.5×10 15 cm −2 of dosage, and then, the RTA is conducted for activation.
Following this, the deep diffusion layer 11 is formed by the ion implantation, after forming, e.g., a silicon nitride film as the gate sidewall film 10 on a sidewall of the gate electrode 8 and the gate insulating film 7 using the LPCVD method, etc. The forming condition of the deep diffusion layer 11 is, e.g., the As ion implantation at 5-25 keV of acceleration voltage and 1×10 5 -5×10 15 cm −2 of dosage for the n-type diffusion layer.
Next, as shown in FIG. 2E , a Ni film is deposited on the silicon substrate 1 and the gate electrode 8 using, e.g., a sputtering method, and the silicon substrate 1 and the gate electrode 8 are silicided by the RTA, which results in that the silicide layer 12 is formed. After forming the silicide layer 12 , an unreacted Ni film is removed by etching using a mixed solution of sulfuric acid and hydrogen peroxide water.
Note that, resistance may be further lowered by using a process in which a low-temperature RTA is conducted once at 250-400° C. followed by etching using the mixed solution of sulfuric acid and hydrogen peroxide water, and then, the RTA is conducted once again at 400-500° C. for lowering sheet resistance, or by depositing a TiN film having electrical resistance lower than that of Ni silicide on the Ni film after Ni sputtering.
FIG. 3B is a graph showing an impurity concentration at A-A′ line of FIG. 1 . FIG. 3A is a graph as a comparative example showing an impurity concentration in case that a SiC layer 3 is not formed. As shown in FIGS. 3A and 3B , it was confirmed that an impurity concentration at an interface between the well region and the high concentration diffusion layer region and an interface between the channel region and the high concentration diffusion layer region is suppressed to be low by forming a SiC layer 3 compared with the case in which the SiC layer 3 is not formed.
According to the above embodiment, following effects can be obtained. Namely, by forming impurity diffusion suppression layers 3 and 4 composed of a SiC layer above and below the impurity channel layer 5 , it is possible to suppress impurity diffusion in a vertical direction from the impurity channel layer 5 and thus to form a channel structure with a steep impurity concentration profile. In detail, by adjusting the Impurity concentration of the silicon substrate 1 to be 1×10 17 cm −3 or less, it is possible to more effectively form a transistor of which junction capacitance and junction leakage are suppressed.
Second Embodiment
FIG. 4 is a cross sectional view in a channel length direction showing a semiconductor device in a second embodiment.
An element isolation portion 14 having a depth of 200-350 nm is formed on an n-type silicon substrate 13 . An n-type well region (not shown) as a pMOSFET forming region (hereinafter referred to as simply “a pMOS region”) and a p-type well region (not shown) as an nMOSFET forming region (hereinafter referred to as simply “an nMOS region”) are formed in the active element portion that is a region divided by the element isolation portions 14 . A typical ion implantation condition for forming the well region is about 500 keV of acceleration voltage and 3×10 13 cm −2 of dosage for an n-type well into which a P ion is implanted, and about 260 keV of acceleration voltage and 2×10 12 cm −3 of dosage for a p-type well into which a B ion is implanted.
A SiGe layer as a first impurity diffusion suppression layer 15 is provided 5-20 nm in thickness on the silicon substrate 13 in the nMOS region, and an impurity channel layer 17 is formed on the SiGe 15 layer. Meanwhile, the impurity channel layer 17 is formed on the silicon substrate 13 in the pMOS region. An As-doped Si layer in the pMOS region and a B-doped or In-doped Si layer in the nMOS region are each formed 10-30 nm in thickness as the impurity channel layer 17 .
A SiGe channel layer 19 is formed on the impurity channel layer 17 in the pMOS region. On the other hand, a SiGe layer as a second impurity diffusion suppression layer 16 is formed on the impurity channel layer 17 in the nMOS region, and a silicon epitaxial layer 18 formed of a non-doped Si crystal formed by an epitaxial growth method is formed on the SiGe layer 16 . Gate insulating films 20 are each formed on the SiGe channel layer 19 and the silicon epitaxial layer 18 .
By forming the SiGe layers as the first impurity diffusion suppression layer 15 and the second impurity diffusion suppression layer 16 so that a germanium atom concentration is 1×10 17 cm −3 or more, it is possible to effectively suppress diffusion of an impurity from the impurity channel layer 17 into the silicon substrate 13 and the silicon epitaxial layer 18 . And then, in the pMOS region, a shallow diffusion layer 22 and a deep diffusion layer 24 are formed spanning any of the SiGe channel layer 19 , the impurity channel layer 17 and the silicon substrate 13 , or plural layers thereof. In the nMOS region, a shallow diffusion layer 22 and a deep diffusion layer 24 are formed spanning any of the silicon epitaxial layer 18 , the first and second impurity diffusion suppression layers 15 and 16 , the impurity channel layer 17 and the silicon substrate 13 , or plural layers thereof.
Then, gate electrodes 21 are formed on the gate insulating films 20 in the pMOS region and the nMOS region, and gate sidewall films 23 are formed on side surfaces of laminate structures of the gate insulating film 20 and the gate electrode 21 in the pMOS region and the nMOS region. And then, silicide layers 25 are formed on the silicon epitaxial layer 18 and the gate electrode 21 in the nMOS region and on the SiGe channel layer 19 and the gate electrode 21 in the pMOS region.
The gate insulating film 20 may be formed of, e.g., a silicon dioxide film, a silicon oxynitride film or a silicon nitride film, etc. The gate electrode 21 is composed of, e.g., a conductor such as polysilicon, etc., or a metal electrode such as tungsten (W) or titanium nitride (TiN), etc. The silicide layer 25 may be formed of, e.g., Ni-silicide, Co-silicide, Er-silicide, Pt-silicide or Pd-silicide, etc.
FIGS. 5A to 5E are cross sectional views showing processes for forming the semiconductor device in the second embodiment.
Firstly, the element isolation portion 14 is formed on a main surface of the silicon substrate 13 by a known method using, e.g., a hard mask such as SiN, etc.
Next, as shown in FIG. 5A , a p-type well (not shown) is formed in the nMOS region portions 14 and an n-type well (not shown) is formed in the pMOS region isolated from the nMOS region by the element isolation. Following this, a SiGe layer as the first impurity diffusion suppression layer 15 is formed in the nMOS region by epitaxially growing a SiGe crystal to a thickness of 5-20 nm. It is possible to effectively suppress diffusion of B or In atoms by forming the SiGe layer 15 so that an atomic percentage (Atomic %) of germanium is 1.0-30.0%. The epitaxial growth method is same as that of the first embodiment, hence, the explanation for the overlapped points is omitted in this embodiment.
Next, as shown in FIG. 5B , an As-doped Si layer and a B-doped or In-doped Si layers are each formed 10-30 nm in thickness as the impurity channel layer 17 on the silicon substrate 13 in the pMOS region and on the first impurity diffusion suppression layer 15 in the nMOS region. After that, SiGe layers as the second impurity diffusion suppression layer 16 to suppress the diffusion of B or In, etc., are formed on the impurity channel layers 17 in the pMOS region and the nMOS region by epitaxially growing a SiGe crystal.
Following this, as shown in FIG. 5C , non-doped Si layers used as the silicon epitaxial layer 18 , that is a channel layer, are each formed about 1-5 nm in thickness on the second impurity diffusion suppression layer 16 in the pMOS region and about 10-15 nm in thickness on the second impurity diffusion suppression layer 16 in the nMOS region. Although the SiGe layer can suppress diffusion of B or In in the impurity channel layer 17 in the nMOS region, the effect to suppress the diffusion of As in the impurity channel layer 17 in the pMOS region cannot be expected. However, by using the second impurity diffusion suppression layer 16 in the pMOS region as a channel layer of a pMOSFET, it is possible to improve characteristics of the pMOSFET and to simplify the processes. A process in which the second impurity diffusion suppression layer 16 in the pMOS region is used as a channel layer of a pMOSFET, is shown below.
Ge in the second impurity diffusion suppression layer 16 is diffused into the silicon epitaxial layer 18 by heat, etc., which is applied after forming the channel region. Since the silicon epitaxial layer 18 in the pMOS region is shallower than the silicon epitaxial layer 18 in the nMOS region, the entire silicon epitaxial layer 18 in the pMOS region becomes a SiGe layer due to the diffusion of the Ge from the second impurity diffusion suppression layer 16 , and the SiGe channel layer 19 composed of the second impurity diffusion suppression layer 16 and the Ge-diffused silicon epitaxial layer 18 is obtained.
As shown in FIG. 5D , a surface of the silicon epitaxial layer 18 is oxidized by a thermal oxidation method or a radical oxidation method, which results in that the gate insulating film 20 is formed.
Following this, on the gate insulating films 20 in the pMOS region and the nMOS region, the about 50-200 nm thick gate electrodes 21 are each formed of, e.g., polysilicon or polysilicon germanium. After forming the gate electrodes 21 , the gate insulating films 20 and the gate electrodes 21 are patterned using a lithographic method or a reactive ion etching method, etc.
Next, the shallow diffusion layers 22 are each formed in the nMOS region and in the pMOS region by ion implantation. When the shallow diffusion layers 22 is an n-type diffusion layer, after conducting B ion implantation under the condition of, e.g., 20 keV of acceleration voltage and 1×10 13 -3×10 13 cm −2 of dosage (30-60 degrees of tilt) as a HALO implantation condition, an As ion is implanted under the condition of 1-5 keV of acceleration voltage and 5×10 14 -1.5×10 15 cm −2 of dosage. On the other hand, when the shallow diffusion layers 22 is a p-type diffusion layer, after conducting As ion implantation under the condition of, e.g., 40 keV of acceleration voltage and 1×10 13 -3×10 13 cm −2 of dosage (30-60 degrees of tilt) as a HALO implantation condition, a B ion is implanted under the condition of 1-3 keV of acceleration voltage and 5×10 14 -1.5×10 15 cm −2 of dosage, and then, the RTA is conducted for activation.
Note that, resistance may be further lowered by using a process in which a low-temperature RTA is conducted once at 250-400° C. followed by etching using the mixed solution of sulfuric acid and hydrogen peroxide water, and then, the RTA is conducted once again at 400-500° C. for lowering sheet resistance, or by depositing a TiN film having electrical resistance lower than that of Ni silicide on the Ni film after Ni sputtering.
Following this, as shown in FIG. 5E , as the gate sidewall film 23 , for example, silicon dioxide films are each formed on sidewalls of the gate electrode 21 and the gate insulating film 20 in the nMOS region and in the pMOS region using the LPCVD method, etc. After forming the gate sidewall film 23 , the deep diffusion layer 24 is formed by, e.g., a B ion implantation at 1-5 keV of acceleration voltage and 5×10 14 -5×10 15 cm −2 of dosage in the pMOS region, and by an As ion implantation at 5-25 keV of acceleration voltage and 1×10 15 -5×10 15 cm −2 of dosage in the nMOS region.
Next, Ni films are each deposited on the silicon substrate 13 and the gate electrode 21 in the nMOS region and in the pMOS region using, e.g., a sputtering method, and the silicon substrate 13 and the gate electrode 21 are silicided by the RTA, which results in that the silicide layer 25 is formed. After forming the silicide layer 25 , an unreacted Ni film is removed by etching using a mixed solution of sulfuric acid and hydrogen peroxide water.
According to the above embodiment, following effects can be obtained. Namely, by forming impurity diffusion suppression layers composed of a SiGe layer above and below the impurity channel layer 17 in the nMOS region, it is possible to form a steep channel structure in which impurity diffusion in a vertical direction from the impurity channel layer is suppressed. In detail, by adjusting the impurity concentration of the silicon substrate 1 to be 1×10 17 cm −3 or less, it is possible to more effectively form a transistor of which junction capacitance and junction leakage are suppressed. In addition, it is possible to simplify the processes by simultaneously forming the impurity diffusion suppression layer in the nMOS region and a SiGe channel layer in the pMOS region.
Third Embodiment
Next, a method of fabricating a semiconductor device in the third embodiment will be explained. In this embodiment, when an impurity channel layer is formed, instead of an impurity doped epitaxial growth in the first or second embodiment, a method, in which a non-doped silicon epitaxial layer is grown and an impurity is introduced into the non-doped silicon epitaxial layer by the ion implantation, is used. Note that, RTA for activation is conducted after the ion implantation. Since the other fabrication processes and a material and a structure of the film are same as the first and second embodiment, the explanation for the overlapped points is omitted here.
When an impurity is introduced into the silicon epitaxial layer of the impurity channel layer by using the ion implantation in the embodiment, it is desirable to adjust an impurity ion range by controlling an acceleration energy so that the impurity ion reaches the impurity channel layer.
According to the above embodiment, following effects can be obtained. Namely, it is possible to form a steep channel structure similar to that of the first and second embodiments, in which the impurity diffusion in a downward direction from the impurity channel layer is suppressed. In detail, by adjusting the impurity concentration of the silicon substrate 1 to be 1×10 17 cm −3 or less, it is possible to more effectively form a transistor of which junction capacitance and junction leakage are suppressed. | A semiconductor device according to one embodiment includes: a semiconductor substrate; a first impurity diffusion suppression layer formed on the semiconductor substrate for suppressing diffusion of a channel impurity; an impurity channel layer formed on the first impurity diffusion suppression layer and containing the channel impurity; a second impurity diffusion suppression layer formed on the impurity channel layer for suppressing diffusion of the channel impurity; a channel layer formed on the second impurity diffusion suppression layer; a gate insulating film formed on the channel layer; and a gate electrode formed on the gate insulating film. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to industrial controllers and in particular to industrial controllers having a modular construction that permits upgrading of the modules during operation of the industrial controller.
Industrial controllers are special purpose computers used for controlling factory automation and the like. Under the direction of a stored program, a processor of the industrial controller examines a series of inputs reflecting the status of a controlled process and changes outputs affecting control of the controlled process.
Typically, the stored program will be unique to the particular control application. Perfecting this control program will frequently require testing of the control program with the actual equipment being controlled.
The circuitry, or hardware configuration of the industrial controller may also be unique to the particular application. Different applications will generally require different numbers and types of I/O circuits depending on the inputs and outputs needed for the controlled process. Some applications will require circuitry to handle specialized control or communication tasks.
For this reason, it is typical to construct the industrial controller in a modular fashion, having one or more functional modules connected together through a common backplane in a rack or the like. The modular construction allows the circuitry of the industrial controller to be customized to some degree for each application and simplifies maintenance and repair of the industrial controller in the event that one or more modules fail.
Normally, the controlled process and the technology of the industrial controller will evolve over time. As a result it may be necessary to modify the control program and upgrade the functional modules of the industrial controller. The functional modules may also need to be changed as part of normal maintenance and repair.
In such cases, the control system may be stopped, the old functional modules removed from the backplane, and the new modules replaced. Similarly, the control system may be stopped to add a new program to the industrial controller or to modify its existing program.
The economics of certain controlled processes, for example manufacturing facilities, make shutting down the controlled process for upgrading of the control system prohibitively expensive. In some batch-type processes, shutting down the process for unscheduled maintenance may cause damage to equipment and spoilage of processed items.
Accordingly, it is desirable that such upgrading and changes of the control system be performed without stopping the controlled process or with only minimal disruption.
To minimize process disruption in changing the control program, it is known to provide for a conditional editing of the control program. Here, two versions of the control program are effectively held on the controller. The controller is then configured to toggle between the versions depending on the state of an internal edit flag. This toggling may occur while the controller is operating.
Upgrading functional modules is more difficult. Removing a functional module while the controlled process is under way may cause unexpected changes in the controller's outputs. Even if the particular functional module were not critical, its loss might provoke a fault condition in the controller, stopping the controlled process entirely. A new functional module replaced in the controller will require some time to re-establish communication with the remainder of the industrial controller.
If the upgrading of the functional module is unsuccessful in some way, additional disruption of the controlled process upon reinsertion of the old module would be inevitable.
BRIEF SUMMARY OF THE INVENTION
The present invention permits the upgrading of the hardware or software of an industrial controller during the control process with minimal down time, and importantly, with the ability to effectively undo the upgrading rapidly if its process or application is unsuccessful.
Generally, the controller includes a redundant primary and secondary controller coordinated with each other so that the secondary controller may take over the control from the primary controller on the occurrence of a switch-over signal. The coordination between controllers is provided by a process termed `qualification` in which the program and data memories and program state of the primary and secondary processors are made to match. In the present invention this qualification process may be suspended, by the setting of a flag, without preventing switch-over. By suspending the qualification process (and subsequent synchronization), the upgrading of one controller does not contaminate the back-up controller which may then be used to recover from unsuccessful upgrading.
Specifically, the present invention provides a secondary industrial controller used for backup for a primary industrial controller, the primary industrial controller having primary functional modules and having a primary memory containing a user program executed to control an industrial process. The secondary industrial controller similarly includes secondary functional modules and a secondary memory which has a version of the user program and a state flag which may be set by user command. The secondary industrial controller also includes a backup circuit communicating with the memory and the functional modules and operating to detect a lack of coherence between the primary functional modules and the secondary functional modules and between the user program and the version of the user program. When a lack of coherence is detected by the back-up circuit, and only when the state flag is not set, the secondary controller copies the user program from the primary controller to the secondary memory.
Thus it is one object of the invention to expand the function of a secondary controller in a redundant control system to include facilitating the upgrading of control software. Normally, a secondary controller will qualify itself so that it is coherent with the primary controller. The qualification process ensures that during switchover, there will be no disruption to the control process, but can cause the secondary controller to be loaded with a possibly unsuccessful software upgrade of the primary controller. This limits the usefulness of the secondary controller as a back-up system.
The present invention, by allowing a temporary disabling of the qualification process, permits one controller to be used as a test platform for software upgrades while the other controller is held in its previous configuration in case the upgrade is unsuccessful.
The blocking of the qualification process may occur in either the original primary or original secondary controller to cover situations where qualification is triggered after a switchover. Either the primary or secondary controllers may serve as the repository of the unchanged software.
The backup circuit may further operate to execute the program in the secondary memory to control the industrial process upon receipt of a switchover signal unless a lack of coherence is detected and the state flag is not set.
Thus it is another object of the invention to permit a switchover between controllers even though coherence has not been maintained if that intent is manifest in the flag setting, and otherwise to prevent such switchover if there is lack of coherence.
The backup circuit may receive as the switchover signal, a signal from the primary controller indicating a condition consisting of the group of failure of a primary functional module or a removal of or insertion of a primary functional module.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a simplified perspective view of an industrial controller having a primary and secondary controller, each composed of functional modules connected by a backplane and contained in separate racks;
FIG. 2 is a block diagram of the functional modules of the primary controllers of FIG. 1 showing connection of the functional modules to the backplane including a fault status line and the removal of one functional module;
FIG. 3 is a block diagram of a functional module of FIG. 2 showing the allocation of memory to a control program, I/O data, configuration flags and an operating system;
FIG. 4 is a figure similar to FIG. 2 showing the functional modules on both a primary and secondary controller and depicting the flow of data when a functional module is removed;
FIG. 5 is a flow chart describing the steps of the operating system program of FIG. 3 as executed by a functional module to cause the switch-over of control from the primary controller, and an attempted auto-qualification of the primary controller when a functional module is removed from the primary controller;
FIG. 6 is a figure similar to FIG. 5 showing the steps executed when a primary module is inserted into the primary controller; and
FIG. 7 is a figure similar to FIGS. 5 and 6 of steps executed by the operating system of a secondary controller in response to removal or insertion of a functional module of the secondary controller.
DETAILED DESCRIPTION OF THE INVENTION
Controller Hardware
Referring now to FIG. 1, an industrial control system 10 of the present invention includes a primary controller 12a and a secondary controller 12b housed in separate racks 14. Each of the racks 14 include multiple functional modules 16 electrically communicating via a backplane 18 comprised of multiple conductors running along the back of the racks 14.
Included among the functional modules 16 may be a communication module permitting communication between the controller 12a and controller 12b, as well as the remote I/O rack 22 along common high-speed link 24. The remote I/O rack 22 includes multiple I/O modules communicating with the controlled process also through lines 20. The I/O modules, communications modules and I/O rack operate generally according to methods well understood in the art with exceptions to be described below.
Controller 12a and controller 12b may also be connected via the same or a separate communication channel to a programming terminal 30 being of a conventional desktop computer design.
Referring now to FIGS. 1 and 2, the backplane 18 includes a parallel bus 32 for high-speed connected messaging between the functional modules 16. The backplane 18 also includes a system failure line 34 which is pulled to a high state in the absence of failure by a pull-up resistor 36.
Spaced along the backplane 18 within the racks 14 are multi-pin connector halves 38 receiving corresponding connector halves 40 attached to the functional modules 16. When a functional module 16 is connected to the backplane 18, the multi-channel bus 32 and the system failure line 34 are electrically connected to the electronics on the functional modules 16 for the exchange of information.
On each functional module 16, the system failure line 34 is received by a card input 42 so that the functional modules 16 may monitor the status of the system failure line 34. On each functional module 16, the system failure line 34 is also connected into a pull-down transistor 44 for asserting the system failure line by pulling it to a low voltage.
As will be understood from this description, the system failure line 34 provides an effective logical OR of failure signals from the individual functional modules 16. Thus, the system failure line 34 signals a failure of at least one functional module 16, but does not distinguish which modules 16 have failed, or how many modules 16 have failed. Importantly, it will be understood that if the functional module 16 is removed from connector half 38, as would be the case in an upgrading of the module 16 during operation of the controller, then the system failure line 34 cannot be asserted and normally no failure is indicated.
Referring now to FIG. 3, a typical functional module 16 will include a processor 46 connected via an internal bus 50 to a link buffer 52 communicating with the connector 40 and ultimately with the bus 32. The bus 50 may also communicate with the card input 42 and pull-down transistor 44 (described above and shown in FIG. 2) collected as I/O 54 in FIG. 3. Bus 50 may also connect to various front panel displays 66 including status lights and the like.
An electronic memory 56, including volatile and non-volatile memory components well understood in the art, is also connected to bus 50 to communicate with the processor 46. Memory 56 holds a user program 60 written to control the particular industrial application at hand. An I/O table 62, of a type understood in the art, is also contained in memory 56 and stores the input and output values exchanged with the controlled process over lines 20, either directly by the functional module 16 or via other functional modules as transferred through the link 24 or the backplane 18. Generally, as is understood in the art, the I/O table 62 is asynchronously updated by special purpose hardware, and the processor 46 accesses the I/O table 62 as updated in the manner of conventional memory.
An operating system program 64 is also contained in memory 56 to provide a number of features related to the present invention as will be described.
Also included in memory 56 are configuration flags 65 recording the state of the module 16 generally, and in the system back-up modules 26 indicating whether the particular controller 12a or 12b is a primary controller or secondary controller, and if a secondary controller whether it is in a standby, disqualified or qualified mode, as will be described below. The flags also indicate whether auto-qualification shall be performed as will be described. The configuration flags 65 in memory 56 may be set by user command or by execution of the operating system 64 as will be described.
Referring now to FIGS. 1 and 3, the controllers 12a and 12b also each include a system back-up module 26 coordinating back-up operation between the primary controller 12a and secondary controller 12b. The system back-up modules 26 communicate via a special-purpose, interchassis data link 28.
The system back-up module 26 is similar to the other functional modules 16, however, in the system back-up modules, the memory 56 does not store the user program 60 or the I/O table 62. In addition, the system back-up modules 26, storing a different operating system 64, operate to coordinate back-up activities as will be described.
Like other functional modules 16, the system back-up modules include the connector 40 to connect them to the bus 32 and to the system failure line 34. In addition, the system back-up modules 26 include a special buffer 68 communicating with the inter-chassis data link 28 described above. This link allows the system back-up modules 26 to coordinate activities between the primary and secondary controllers in providing back-up for one another without need for or interference with the link 24 (which is independently susceptible to failure).
Referring now to FIGS. 2 and 4, in the present invention the functional modules 16 may be freely removed from their racks 14 during operation of the controllers 12a and 12b. For this reason, special provisions must be made to detect such removal and to coordinate a transfer of control between the primary controller 12a and secondary controller 12b when a module is removed.
Operation of the System Back-up Modules
Referring now to FIG. 4, first controller 12a may include a system back-up module 26a and two functional modules 16a and 16a', the latter of which will be removed. Second controller 12b includes a back-up module 26b and two functional modules 16b (only one of which is shown). In the following discussion, it will be understood that the primary and secondary controller are perfectly symmetric and that the term "primary" and "secondary" refer only to which controller was most recently controlling the process. It will be assumed that first controller 12a is initially the primary controller.
Qualification
During normal operation of the controllers 12a and 12b, first controller 12a will act as a primary controller, actively controlling an industrial process in the manner of a conventional industrial controller. In order that the second controller 12b be prepared to undertake control of that process if controller 12a is incapacitated, it is necessary that controller 12b have the same user program 60 and I/O table 62 as that present in primary controller 12a.
This coordination of the controllers 12a and 12b is provided by a process termed "qualification" in which there is a cross-loading of the memories 56 of the first controller 12a and the second controller 12b. Qualification is followed by a constant updating of the I/O tables as they change (synchronism).
Periodically, auto-qualification (if enabled) will occur if there is an indication that the `coherence` between the primary controller 12a and secondary controller 12b has been lost. Coherence indicates that the program 60 in the primary controller 12a and secondary controller 12b are identical, and that the hardware configurations as reflected in the functional module 16 are the same. Events indicating a lack of coherence, detected by either system back-up module 26, will trigger an auto-qualification of the then secondary controller. Such events include start up of the industrial controller, removal or replacement of functional modules 16.
More specifically, two autoqualification flags 65 are stored in memory 56. The first is user setable and has three possible values: Never Autoqualify, Always Autoqualify, and Conditionally Autoqualify. The second flag (termed the state flag) holds the current state of autoqualification : enabled or disabled. The state flag is set to enabled when the user selects Always Autoqualify and set to disabled when the user selects Never Autoqualify. When the user selects Conditionally Autoqualify, the state is left unchanged but will change when any of the following occur:
______________________________________Occurrence Effect on Flag______________________________________Qualification command received EnabledDisqualify Secondary command received DisabledEnter Standby command received DisabledSwap to Standby Command received Disabled______________________________________
Qualification is performed under the operating systems of the system back-up modules 26 and includes three stages. In a first stage, it is verified through the system back-up modules 26a and 26b, that each functional module 16 in the primary controller has a corresponding module 16 with similar configuration in the other controller 12. In the second stage, the memory 56 of each module 16 of the primary controller 12 is cross-loaded to the memory of the secondary controller 12. This cross loading includes the user program 60 and the I/O table 62. In the third stage, changes to the configuration flags 65 and programs 60 which have been locked out in stage one are released. After qualification is successfully completed, the system back-up modules 26a and 26b check to see if a switch-over should occur.
Detecting Module Removal
During operation of the controllers 12, the circuitry of the link buffer 52 (shown in FIG. 3) of the system back-up modules 26 monitors activity on the backplane 18 by the other modules 16. The system back-up module 26a then polls the functional modules 16a and 16a' not having recent activity with polling message 70. In this polling process, system back-up module 26a sends a message to functional module 16a which then responds indicating receipt of the message. System back-up module 26a then sends a similar polling message 70 to functional module 16a' and so forth for each functional module, whereupon the process is repeated as frequently as once every 5 milliseconds. Importantly, this polling process does not require processor 46 to be diverted from its tasks and because only `quiet` modules 16 are polled, bandwidth of the backplane 18 is preserved.
When functional module 16a' is removed from the backplane 18 over which these messages are sent and received, it will either be unable to receive the polling message or unable to respond. This indicates to system back-up module 26a that module 16a' has been removed from the backplane 12. At this time, system back-up module 26a, according to instructions from its operating system, sends a switch-over signal 72 to its companion back-up module 26b in secondary controller 12b. Simultaneously, system back-up module 26a sends a shut-down message 73 to the remaining connected modules 16a to cease operation. System back-up module 26b in turn sends start-up messages 74 to its modules 16b, activating them for control.
In the event that the system back-up module 26a is removed, the switching to the secondary chassis must be accomplished by the remaining back-up module 26b detecting a loss of communication with module 26a. In this case, it is important that functional modules 16a stop functioning as if they had received shut-down message 73 from the system back-up module 26a.
To accomplish this purpose, the system back-up module 26a designates one of the functional modules 16a to periodically send a reverse polling message 75 to the system back-up module 26a. In the event that the designated module 16a detects a removal of the module 26a, it provides the necessary shut-down message 73 to the other modules 16a as indicated by phantom line 73'. The selection of this module 16a as the designated functional module is performed at the time of power-up or if no suitable modules are available at power-up, when a suitable module is inserted.
Alternatively, all modules may detect removal of the system back-up module by sending polling messages when no activity has been detected. In this way, no communication between remaining modules is required but they may shut down independently.
Responding to Module Removal
Referring now to FIG. 5 and FIG. 6, if any module 16 is removed from or inserted into a primary controller 12, the system back-up modules 26 will respond in different ways depending on whether the secondary controller 12 is in a standby, qualified or disqualified mode.
The standby state is set by the user; the qualified and disqualified modes are determined by whether the controllers have coherence. Generally, but as will be defined further below, a qualified secondary controller 12 has had the qualification process completed and is ready to assume control if a switch-over signal is received from the system back-up module 26. Similarly, a disqualified secondary controller 12 has not been qualified or has failed qualification and is not ready to assume control of the controlled process and will refuse such control. In the standby state, the secondary controller 12 has been qualified once and is now locked against further qualification regardless of changes in the primary controller. The purpose of this standby state is to provide a known stable environment that may be returned to when upgrades being tested on the other controller are unsuccessful. A secondary controller 12 in standby mode will assume control, even though it is not necessarily coherent as described above with the primary controller 12.
Referring to FIGS. 4 and 5, when the primary module 16a' is removed from a primary controller 12a at process block 80, then at succeeding decision block 82, the status of the secondary controller 12b as recorded in the configuration flags 65 of the primary controller 12a is determined. If the secondary controller 12b is in a standby mode, then as indicated by process block 84, a switch-over signal 72 is sent from system back-up module 26a to system back-up module 26b. In addition signals 73 and 74 are sent to their respective modules 16 to cause a switch-over of control from the primary controller 12a to the secondary controller 12b. The primary controller 12a then moves to a disqualification state by setting its configuration flags 65 appropriately.
Disqualification of the controller 12a, now the secondary controller, triggers an auto-qualification inquiry indicated by process block 86. The present invention provides for conditional auto-qualification depending on the setting of a configuration flag 65. If that auto-qualification state flag is set to disabled, no qualification is initiated and the new secondary controller 12a remains disqualified with its same user program.
If the conditional auto-qualification flag is set to enabled, the new secondary (former primary) controller 12a is qualified as indicated by process block 88 using the steps described above, thus bringing it into coherence with the user program of controller 12b.
If the status of the secondary controller 12b at the time a primary module is removed per process block 80 is qualified, then per process block 90, there is simply a switch-over from controller 12a to controller 12b, as described with respect to process block 84 in FIG. 5.
Finally, if the secondary controller 12b is disqualified as determined by decision block 82 and the removed module is required by the remaining module 16a as indicated by decision block 91, then the program proceeds to a fault state 92 similar to that provided in normal industrial controllers without back-up provision. Typically, the fault state will return all outputs of the industrial controller to a predetermined "safe" state and provide fault indications to the operator.
Referring now to FIG. 6, a slightly different procedure is followed if a primary module 16a is inserted into the primary controller 12a as detected by the system back-up module 26a, as indicated by process block 96. In this case, the status of the secondary controller 12b is again investigated as indicated by decision block 98 through a query of the appropriate configuration flags 65.
If the secondary controller 12b is in a standby or qualified mode, a switch-over of control to the secondary controller 12b is performed and the primary controller 12a is disqualified per process block 100. Next the status of auto-qualification state is checked in process block 102, and depending on that check, a qualification of the former primary processor 12a (new secondary) is performed in process block 104. Process blocks 100, 102, and 104 correspond in function to process blocks 84, 86 and 88 of FIG. 5.
If at decision block 98 the status of the secondary controller 12b is disqualified, the program proceeds to process block 106 where the secondary controller 12b is instructed to perform a qualification to bring it back into coherence with the primary controller 12a.
For both the situations of FIG. 5 and FIG. 6, modules 16a are inserted or removed from the primary controller 12a, i.e., the controller performing the control at the time of the removal or insertion. Referring now to FIG. 7, if a module 16b is inserted or removed from the secondary controller 12b (or the controller 12a after it has switched control functions over to the controller 12b) as indicated by process block 108, then the system back-up modules 26b again determine the status of its own secondary controller 12b as indicated by decision block 110. If the secondary controller is in standby or qualified mode, then the secondary controller 12b is disqualified as indicated by process block 112. The program then proceeds to decision block 114 described below.
Alternatively, if the secondary controller is disqualified, then after decision block 110, the program proceeds to decision block 114 and the autoqualification state flag is checked as was described at process blocks 86 and 102 of FIGS. 5 and 6. If qualification is to occur, then the program proceeds to process block 116 and an auto-qualification of the secondary controller is performed as described above. Otherwise, no qualification is performed.
Generally, as module 16 is removed from the backplane 18, it does not create a system failure on the system failure line described with respect to FIGS. 2 and 3. If a controller 12a has a qualified secondary 12b, the system back-up module 26a, upon receiving a system fail signal from the module 16a, ceases the user program, causes a switch-over of control to the secondary controller 12b and enters a disqualified secondary state. The modules themselves await instructions from the system back-up module for the purpose of an orderly shutdown and start-up of communications, but if no instructions are received, enter a disqualified secondary state, assuming that the system back-up module is the module that has failed.
It will be understood from the above discussion of FIGS. 5, 6 and 7 that the combination of standby mode as described by those figures, and the conditional auto-qualification, both of which may be programmed by flags in the configuration register, are such as to permit the simple upgrading of an industrial controller 12a by removal and insertion of modules therein. The following examples will describe the steps by which upgrading may be performed.
Example 1
The following steps may be taken to upgrade a functional module 16a of primary controller 12a with a qualified secondary controller 12b when qualification is possible between modules of different revisions. Qualification is enabled.
1. The module 16a is removed from the rack 14 of processor 12a. Result: Per the flow chart of FIG. 5, removal is detected by system back-up module 26a (at process block 80), which causes a switch-over to a qualified secondary processor 12b (per process block 90).
2. Module 16a is upgraded in hardware or firmware while control continues in controller 12b with the controller 12a disqualified.
3. Module 16a is re-installed in controller 12a. Result: Per the flow chart of FIG. 7, insertion is detected at process block 108 and disqualified controller 12a performs a qualification per process block 116, becoming a qualified secondary to controller 12b.
4. Corresponding module 16b to the one upgraded in the controller 12a is removed from controller 12b. Result: Per the flow chart of FIG. 5, removal is detected by system back-up module 26a (at process block 80), which causes a switch-over to a qualified secondary processor 12a (per process block 90).
5. Module 16b is upgraded in hardware or firmware while control continues in controller 12a with the controller 12b disqualified.
6. Module 16b is re-installed in controller 12b. Result: Per the flow chart of FIG. 7, insertion is detected at process block 108 and disqualified controller 12b performs a qualification per process block 116, becoming a qualified secondary to controller 12b.
Example 2
Similar steps may be used to upgrade both controllers 12a and 12b by installing an additional module 16 to those already present. Again controller 12a is initially a primary controller with a qualified secondary controller 12b. Qualification is enabled.
1. New module 16a is added to primary controller 12a. Result: Per FIG. 6, the added module is detected by system back-up module 26a (at process block 96), which causes switchover. Qualification is successfully performed per process block 106.
2. Corresponding new module 16b is added to controller 12b. Result: Per FIG. 6, the added module is detected at process block 96, switchover performed at block 100 and qualification is performed successfully per process block 104 as both controllers now have the same modules.
Example 3
Alternatively, the new module may be added first to the secondary chassis 12b in the following steps.
1. New module 16b is added to secondary chassis 12b. Result: Per FIG. 7, the added module is detected by system back-up module 26a (at process block 108), which causes secondary controller 12b to become disqualified. Qualification is successfully completed at process block 116.
2. Corresponding new module 16a is added to primary controller 12a. Result: Per FIG. 6 the added module is detected at process block 96 and causes switchover at block 100 and qualifying at block 104.
Example 4
In the following examples, it is assumed that controller 12a is initially the primary controller and controller 12b the secondary controller in a qualified state. In these examples, however, the conditional auto-qualification is disabled. Generally, this permits upgrading of the control program or module firmware, while locking out qualification so as to ensure that a copy of the unchanged program is preserved in the event of a failure of the upgrades. The following steps may be performed.
1. The qualified secondary controller 12b is placed in standby (this disables auto-qualification) and its control program is upgraded The actual sequence may be a disqualification of the secondary controller, and editing of its program (for example) and a placing of the secondary controller in standby or simply placing the controller in standby originally. If the controller is first disqualified, then a switchover cannot occur during the upgrading process. If the controller is first placed in standby, a switchover can occur during the upgrading process.
Result: Because secondary controller 12b is in standby, the primary's program will not cause a qualification that might overwrite the upgrade.
Updating of the I/O table 62 in the primary continues and the secondary controller 12b will accept a switch-over.
2. By user command, a switch-over from controller 12a to standby secondary controller 12b ("swap to standby" command) is initiated.
Result: The primary controller 12a becomes a secondary controller in standby mode. Qualification of new secondary controller 12a to the upgraded program of the new primary controller 12b is prevented by the previous deactivation of the auto-qualify mode of controller 12a.
3. If the upgrade results in a system fault, an automatic switchover will return control to the original processor.
4. If the upgrade does not result in a fault but is unacceptable, processor 12a is returned to control with the original program by user commanded switch-over. The user can then attempt further edits to the program in processor 12b or initiate qualification which will cross load the original program from 12a to 12b.
5. If the upgrade is acceptable, the user can initiate qualification which will crossload the upgraded program from 12b to 12a.
The standby mode may also be used to allow a new program to be developed off-line and loaded into the secondary controller 12b by:
(1) disqualifying the secondary
(2) loading the new program, and
(3) placing the controller in standby
Example 5
Conversely, editing of the program on the primary controller 12a may be accomplished while holding the secondary controller in standby (loaded with the original program) with the following steps.
1. The secondary controller 12b is placed in standby state, this disables the auto-qualification.
2. The program 60 in one or more functional modules 16a of primary controller 12a is upgraded while controller 12b is in standby.
Result: Controller 12b does not qualify itself because it is in standby, thereby preserving the original version of the program 60.
3. If the upgraded program results in a fault condition, an automatic switchover will return control to the original program in controller 12b.
4. If the upgraded program does not result in a fault but is unacceptable, the user can return control to the original program by initiating a user commanded switchover.
Result: The original program is executed again, while the upgrades are protected against overwriting by the process of qualification.
5. If the upgrade is acceptable, the standby secondary can be qualified by user command.
The above description has been that of a preferred embodiment of the present invention. It will occur to those that practice the art that many modifications may be made without departing from the spirit and scope of the invention. For example, in a computing system where components communicate freely with each other, particular hardware or operating programs may be distributed among different components and hence, for example, the back-up functions of the back-up module need not be performed in a particular unit but may be spread out among units. In order to apprise the public of the various embodiments that may fall within the scope of the invention, the following claims are made. | An industrial controller provides a primary controller and a redundant secondary controller and allows switchover between the controllers in the event of a failure in the primary controller. The process of qualification of the secondary controller in which its programming is made to match the primary controller may be inhibited to permit the secondary controller to maintain a clean version of an upgraded program executing on the primary controller. The clean program may be reverted to in the event an upgrading of the program in the primary controller is unsuccessful. Switchover is permitted even though the qualification of the secondary controller is not enabled. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of priority to U.S. Provisional Patent Application No. 61/935,830, titled MULTI-FUNCTION ELECTRIC BRUSH APPARATUS AND SYSTEMS USEFUL FOR CLEANING TEETH AND INTERDENTAL SPACES, filed Feb. 4, 2014, the disclosure of which is hereby incorporated by reference herein in its entirety.
FIELD
[0002] The disclosure generally relates to oral hygiene tools. In particular, the disclosure relates to electric cleaning tools having a brush for cleaning teeth.
BACKGROUND
[0003] As is known, a toothbrush is an oral hygiene instrument that is useful for cleaning teeth and gums. Conventional toothbrushes may include one or more heads of bristles that are arranged for cleaning the oral cavity—particularly, the teeth, tongue, and gums. Toothpaste is typically an abrasive fluid, paste, or gel dentifrice, and is used with toothbrushes to enhance cleaning by mechanical action. The cleaning effectiveness of toothbrushes has also been enhanced by using different bristle textures, sizes, and forms. In the past century, conventional toothbrushes have been modified to include soft bristles to protect tooth enamel and minimize gum damage and/or irritation, and may be formed of nylon or other materials that have desirable hardness and durability.
[0004] Some conventional toothbrushes are powered by electricity. An electric toothbrush includes a brush that is driven by a motor and oscillates or rotates the brush. Electric toothbrushes have been found to be easier to use than brushes that require completely manual brushing action. Moreover, electric toothbrushes have been clinically proven to generally be more effective for cleaning teeth than unpowered toothbrushes.
[0005] Other types of conventional toothbrushes include interdental or interproximal brushes and end-tufted brushes. Interdental cleaning instruments such as interdental brushes are designed for cleaning between teeth, and between braces and teeth. An interdental cleaning instrument may have a cleaning head that has a tapered surface profile. For example, a head of an interdental cleaning instrument may have a conical shape for cleaning the narrow spaces between teeth. An interdental cleaning instrument may alternatively include a brush having bristles located about a slender rod that is suitable for sliding between teeth to clean interdental spaces.
[0006] End-tufted toothbrushes are designed for cleaning along gumlines adjacent to teeth. End-tufted toothbrushes typically include a bristle head that is shaped to form an angled cleaning surface that conforms to interdental spaces.
[0007] Dental instruments are conventionally required to perform specific dedicated cleaning functions for which they are narrowly suitable. Thus, an improved multi-functional electric toothbrush configured for easier, more effective, and more comprehensive tooth and interdental space cleaning may be beneficial.
SUMMARY
[0008] Certain embodiments of the present invention may provide solutions to the problems and needs in the art that have not yet been fully identified, appreciated, or solved by current dental cleaning technologies. For example, in some embodiments of the present invention, a powered multi-function brush advantageously enables simultaneous cleaning of flat tooth surfaces and interdental spaces. Further, the multi-function brush of some embodiments may be useful for orthodontic, pedodontal, and periodontal applications, and may enable enhanced subgingival cleaning.
[0009] In an embodiment, a powered dental and interdental cleaning apparatus includes a body having a first end and a second end. The apparatus has an interdental cleaning member, a drive member, and a neck. The drive member extends from the first end of the body at an angle to a longitudinal axis of the body. The drive member is connected to the interdental cleaning member. The neck has a first end and a second end, and the neck extends from the first end of the body at the first end of the neck. The neck is configured to define or contain a drive member shaft that contains the drive member.
[0010] In another embodiment, a brush assembly includes an outer brush forming a ring that defines a central opening. The brush assembly also includes an interdental cleaning member surrounded by the outer brush. The outer brush and the interdental cleaning member are configured and arranged to enable the interdental cleaning member to reciprocate axially through the opening.
[0011] In yet another embodiment, a powered dental and interdental cleaning apparatus includes an outer brush forming a ring that defines a central opening. The apparatus also includes an interdental cleaning member surrounded by the outer brush. The outer brush and the interdental cleaning member are configured and arranged to enable the interdental cleaning member to pulse or reciprocate axially through the opening. The apparatus further includes a drive assembly configured to rotate the outer brush and cause pulsing movement of the interdental cleaning member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] In order that the advantages of certain embodiments of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. While it should be understood that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:
[0013] FIG. 1 is a perspective view of a drive system for a multi-functional electric brush, according to an embodiment of the present invention.
[0014] FIG. 2 is a top view of a drive system for a multi-functional electric brush, according to an embodiment of the present invention.
[0015] FIG. 3 is a cross-sectional view of a drive system, according to an embodiment of the present invention.
[0016] FIG. 4 is another cross-sectional view of a drive system, according to an embodiment of the present invention.
[0017] FIG. 5 is an exploded view of a drive system, according to an embodiment of the present invention.
[0018] FIG. 6 is a perspective view of a multi-functional electric brush, according to an embodiment of the present invention.
[0019] FIG. 7 is a perspective cutaway view of a multi-functional electric brush showing a drive system, according to an embodiment of the present invention.
[0020] FIG. 8 is a side view of a multi-functional electric brush, according to an embodiment of the present invention.
[0021] FIG. 9 is a top view of a multi-functional electric brush, according to an embodiment of the present invention.
[0022] FIG. 10 is a perspective view of a multi-functional electric brush, according to an embodiment of the present invention.
[0023] FIG. 11 is an end view of a multi-functional electric brush, according to an embodiment of the present invention.
[0024] FIG. 12 is a cross-sectional view of a multi-functional electric brush, according to an embodiment of the present invention.
[0025] FIG. 13 is a exploded view of a brush assembly, according to an embodiment of the present invention.
[0026] FIG. 14 is a top view of a brush assembly for a multi-functional electric brush according to an embodiment of the present invention.
[0027] FIG. 15 is a cross-sectional end view of a head of a multi-functional electric brush, according to an embodiment of the present invention.
[0028] FIG. 16A is a perspective view of a head of a multi-functional electric brush, according to an embodiment of the present invention.
[0029] FIG. 16B is another perspective view of the head of the multi-functional electric brush, according to an embodiment of the present invention.
[0030] FIG. 16C is yet another perspective view of the head of the multi-functional electric brush, according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0031] Some embodiments of the present invention pertain to a powered multi-function brush that enables simultaneous cleaning of flat tooth surfaces and interdental spaces. The multi-function brush may be useful for orthodontic, pedodontal, and periodontal applications, and may enable enhanced subgingival cleaning under the gumline. For example, the multi-function brush in some embodiments may include an interdental cleaning member that is configured to reach approximately 3 to 5 millimeters below the gumline, and preferably is configured for cleaning at about 5 millimeters below the gumline. The interdental cleaning member may reach further, however, as a matter of design choice.
[0032] FIG. 1 is perspective view of a drive system 100 for a multi-functional electric brush, according to an embodiment of the present invention. Drive system 100 includes a body 101 . Body 101 contains or supports a drive assembly 103 .
[0033] Drive assembly 103 includes a drive member 107 . Drive member 107 may be a shaft or any other suitable extension that would be appreciated by one of ordinary skill in the art. Drive member 107 may be connected to a brush head assembly (not shown). Drive assembly 103 includes a worm 111 that is configured to interlock with a worm gear or worm wheel 115 .
[0034] Drive assembly 103 may be configured to cause rotation and pulsing of drive member 107 . In particular, worm wheel 115 may be rotated, driving worm 111 , which, in turn, may cause drive member 107 to rotate. Conversely, worm 111 may drive worm wheel 115 . Worm wheel 115 may be configured and arranged to cause a portion of drive member 107 to reciprocate and pulse back and forth axially, in a direction perpendicular to a direction of rotation of drive member 107 . For example, an arm 117 may be attached at a first end of arm 117 to worm wheel 115 at an eccentric location, as shown. A second end of arm 117 may be connected to drive member 107 and configured such that movement of arm 117 causes axial movement of drive member 107 .
[0035] As shown, worm wheel 115 is attached to arm 117 , which is attached to a movable portion 119 of drive system 100 . Movable portion 119 may be configured to contact and move drive member 107 . Movable portion 119 may be arranged on tracks that enable movement of movable portion 119 caused by worm wheel 115 . Movable portion 119 is connected to drive member 107 for moving drive member 107 as a result of rotation of worm wheel 115 . As such, the rotation of worm wheel 115 may cause a combination of rotation and axial movement or pulsing of drive member 107 .
[0036] FIG. 2 is a top view of a drive system 200 for a multi-functional electric brush, according to an embodiment of the present invention. Drive system 200 has a body 201 . Body 201 contains or supports a drive assembly 203 .
[0037] Drive assembly 203 includes a drive member 207 . Drive member 207 may be connected to a brush head assembly (not shown). Drive assembly 203 includes a worm 211 that is configured to interlock with a worm gear or worm wheel 215 .
[0038] Drive assembly 203 may be configured to cause rotation and pulsing of drive member 207 . In particular, worm wheel 215 may be caused to rotate, driving worm 211 , which, in turn, may cause shaft 207 to rotate. Conversely, worm 211 may drive worm wheel 215 . Worm wheel 215 may be configured and arranged to cause a portion of drive member 207 to reticulate back and forth axially, in a direction perpendicular to a direction of rotation of drive member 207 . For example, an arm 217 may be attached at a first end of arm 217 to worm wheel 215 at an eccentric location, as shown. A second end of arm 217 may be connected to drive member 207 and configured such that movement of arm 217 causes axial movement of drive member 207 .
[0039] As shown, worm wheel 215 is attached to arm 217 , which is attached to a movable portion 219 of drive system 200 . Movable portion 219 may be configured to contact and move drive member 207 . Movable portion 219 may be arranged on tracks that enable movement of movable portion 219 caused by worm wheel 215 . Movable portion 219 is connected to drive member 207 for moving drive member 207 as a result of rotation of worm wheel 215 . As such, the rotation of worm wheel 215 may cause a combination of rotation of drive member 207 and axial movement or pulsing of drive member 207 .
[0040] FIG. 3 is a cross-sectional view of a drive system 300 , according to an embodiment of the present invention. Drive system 300 has a body 301 . Body 301 contains or supports a drive assembly 303 .
[0041] Drive assembly 303 includes a drive member 307 . Drive member 307 may be connected to a brush head assembly (not shown). Drive system 303 may include a worm (not shown) that is configured to interlock with a worm gear or worm wheel (not shown). For example, the worm gear and the worm may be selected to be at a 4:1 ratio. Accordingly, for every four rotations of drive member 307 , drive member 307 would pulse in and out in one movement. Drive system 303 may be configured to cause rotation and pulsing of drive member 307 .
[0042] FIG. 4 is a cross-sectional view of a drive system 400 , according to an embodiment of the present invention. Drive system 400 includes a body 401 . Body 401 contains or supports a drive assembly 403 .
[0043] Drive assembly 403 includes a drive member 407 . Drive member 407 may be connected to a brush head assembly (not shown). Drive system 403 may include a worm (not shown) that is configured to interlock with a worm gear or worm wheel (not shown). Drive system 403 may be configured to cause rotation and pulsing of drive member 407 .
[0044] FIG. 5 is a cross-sectional view of a drive system 500 , according to an embodiment of the present invention. Drive system 500 includes a drive member 507 . Drive member 507 may be connected to a brush head assembly (not shown). Drive system 500 includes a worm 511 that is configured to interlock with a worm gear or worm wheel 515 . Drive system 500 may be configured to cause rotation and pulsing of drive member 507 . As shown in FIG. 5 , worm 511 is fixed to the drive member 507 and configured to interlock with worm wheel or worm gear 515 . Worm gear 515 may be caused to move and thus rotate worm 511 to cause rotation of drive member 507 . Conversely, worm 511 may be caused to rotate, and thus rotate worm gear 515 .
[0045] FIG. 6 is a perspective view of a multi-functional electric brush 600 , according to an embodiment of the present invention. Multi-functional electric brush 600 includes a body 601 . Body 601 contains or supports a drive system (not shown).
[0046] Body 601 is connected to a neck 621 at a first end of neck 621 . A brush assembly head 631 may extend from or be connected to a second end of neck 621 . Body 601 may define an opening for access to the drive system. A button, switch, or other now known or later developed actuating mechanism 625 may be connected to the drive system and accessible through the opening of body 601 . Actuating mechanism 625 may be configured to enable and cause an adjustment of the drive system. For example, actuating mechanism 625 may facilitate turning on and off the device, and adjusting a speed of the drive system of multi-functional electric brush 600 . In some embodiments, the drive system may be connected to a variable speed motor (not shown). The motor and actuating mechanism 625 may be configured for variable speed adjustment of the motor, and thus variable speed adjustment of the drive system.
[0047] Drive member 607 may be flexible to accommodate angled extension from body 601 to a brush assembly 631 . In some embodiments, the angle may be about 20 degrees. As shown in FIG. 6 , body 601 and neck 621 may have a unitary construction where body 601 , neck 621 , and brush assembly 631 form a substantially unitary construction. For example, portions of body 601 , neck 621 , and brush assembly 631 may be formed from a single material.
[0048] The brush assembly includes interdental cleaning member 635 and an outer brush member 637 . Outer brush member 637 may be configured to form a ring defining a central opening, and interdental cleaning member 635 may be disposed for movement inside the ring in a direction substantially perpendicular to a direction of rotation of brush member 637 . Outer brush member 637 is supported by a brush support member 639 . Multi-functional electric brush 600 is advantageously suitable for cleaning tooth surfaces, and particularly for cleaning tooth surfaces in areas of the mouth that are difficult to reach, including interdental regions and spaces.
[0049] FIG. 7 is a perspective view of a multi-functional electric brush 700 , according to an embodiment of the present invention. Multi-functional electric brush 700 has a body 701 . Body 701 contains or supports a drive system. The drive system shown in FIG. 7 is in accordance with a different embodiment than that shown in FIG. 1 . The drive system includes a drive member 707 . Drive member 707 may be a flexible shaft in some embodiments.
[0050] Body 701 is connected to a neck 721 at a first end of neck 721 . Neck 721 may include support structures that support drive member 707 . Drive member 707 may include a cable, wire, flexible shaft or rod, or any other suitable structure. Drive member 707 may be formed of metal, an alloy, a polymer, a composite, or any other suitable material that is now known or later developed. A head assembly 731 is connected to a second end of neck 721 . A button, switch, or other now known or later developed actuating mechanism 725 is connected to the drive system and through an opening of body 701 . Actuating mechanism 725 may be configured to enable and cause an adjustment of the drive system. For example, actuating mechanism 725 may facilitate turning multi-functional electric brush 700 on and off and adjusting a speed of the drive system. In some embodiments, the drive system may be connected to a variable speed motor (not shown). The motor and actuating mechanism 725 may be configured for variable speed adjustment of the motor, and thus variable speed adjustment of the drive system.
[0051] Drive member 707 is connected to a motor 727 at a first end of drive member 707 . Motor 727 may be powered by a power source. The power source may be a battery power source, power from an outlet, or any other suitable AC or DC source, for example. Motor 727 may be connected to actuating mechanism 725 to enable variable speed control. Motor 727 may be anchored for rotation inside body 701 .
[0052] Drive member 707 may be flexible to accommodate angled extension from body 701 to a brush assembly 731 . In some embodiments, the angle may be about 20 degrees. Brush assembly 731 may include an interdental cleaning member 735 and an outer brush member 737 . Outer brush member 737 may be configured to form a ring defining a central opening, and interdental cleaning member 735 may be disposed for movement inside the ring in a direction substantially perpendicular to a direction of rotation of brush member 737 .
[0053] Outer brush member 737 may be supported by a brush support member 739 . Drive member 707 may be contained or supported within a drive shaft defined by neck 721 . Support structures formed in or defined by the interior of neck 721 may be useful for supporting an angled, flexible drive member. Drive member 707 may be connected at a second end to a crankshaft assembly having a brush assembly support gear 741 and a drive member gear 745 . Drive member gear 745 may be attached to and rotated by drive member 707 . Drive member gear 745 may be configured to interlock with and cause rotation of brush assembly support gear 741 .
[0054] The second end of drive member 707 may be attached to an offset connecting rod (not shown). The connecting rod may be associated with a ball and socket assembly (not shown). The ball and socket assembly may connected to interdental cleaning member 735 and may be configured to cause interdental cleaning member 735 to move up and down in a direction perpendicular to the direction of rotation of drive member 707 as drive member 707 rotates.
[0055] Brush support member 739 may be connected to brush assembly gear 741 . When drive member 707 is rotated by motor 727 , drive member gear 745 is caused to rotate brush assembly gear 741 , thus rotating outer brush 737 attached to brush support 739 . Meanwhile, rotating drive member 707 moves the connecting rod to cause pulsing movement of interdental cleaning member 735 through the central opening of outer brush 737 . In some embodiments, interdental cleaning member 735 may also be connected to brush assembly gear 741 to enable rotation of cleaning member 735 during the pulsing. For example, when a gear ratio of brush assembly gear 741 and drive member gear 745 is 1:2, interdental cleaning member 735 may rotate at a same speed as outer brush 737 , and pulse in a direction perpendicular to a direction of rotation at a speed of about twice the speed of rotation of interdental cleaning member 735 . Accordingly, multi-function brush 700 advantageously enables simultaneous cleaning of flat tooth surfaces and interdental spaces.
[0056] FIG. 8 is a side view of a multi-functional electric brush 800 , according to an embodiment of the present invention. Multi-functional electric brush 800 includes a body 801 . Body 801 contains or supports a drive system (not shown).
[0057] Body 801 is connected to a neck 821 at a first end of neck 821 . A head 831 is connected to a second end of neck 821 . Body 801 may define an opening for access to the drive system. A button, switch, or other now known or later developed actuating mechanism 825 may be connected to the drive system and accessible through the opening of body 801 . Actuating mechanism 825 may be configured to enable and cause an adjustment of the drive system. For example, actuating mechanism 825 may facilitate turning multi-functional electric brush 800 on and off and adjusting a speed of the drive system. In some embodiments, the drive system may be connected to a variable speed motor (not shown). The motor and actuating mechanism 825 may be configured for variable speed adjustment of the motor, and thus variable speed adjustment of the drive system.
[0058] Drive member 807 may be flexible to accommodate angled extension from body 801 to a brush assembly 831 . In some embodiments, the angle may be about 20 degrees. Brush assembly 831 may include the interdental cleaning member (not shown) and an outer brush member 837 . Outer brush member 837 may be configured to form a ring defining a central opening, and the interdental cleaning member may be disposed for movement inside the ring in a direction substantially perpendicular to a direction of rotation of brush member 837 . Outer brush member 837 may be supported by a brush support member 839 . Multi-functional electric brush 800 shown in FIG. 8 is advantageously suitable for cleaning tooth surfaces, and particularly for cleaning tooth surfaces in areas of the mouth that are difficult to reach, including interdental regions and spaces.
[0059] FIG. 9 a top view of a multi-functional electric brush 900 , according to an embodiment of the present invention. Multi-functional electric brush 900 includes a body 901 . Body 901 contains or supports a drive system.
[0060] Body 901 is connected to a neck 921 at a first end of neck 921 . A head 931 is connected to a second end of neck 921 . Body 901 may define an opening for access to the drive system. A button, switch, or other now known or later developed actuating mechanism 925 may be connected to the drive system and accessible through the opening of body 901 . Actuating mechanism 925 may be configured to enable and cause an adjustment of the drive system. For example, actuating mechanism 925 may facilitate turning multi-functional electric brush 900 on and off, and adjusting a speed of the drive system.
[0061] Drive member 907 may be flexible to accommodate angled extension from body 901 to a brush assembly 931 . In some embodiments, the angle may be about 20 degrees. The brush assembly may include an interdental cleaning member 935 and an outer brush member 937 . Outer brush member 937 may be configured to form a ring defining a central opening, and interdental cleaning member 935 may be configured and arranged for movement inside the ring in a direction substantially perpendicular to a direction of rotation of outer brush member 937 . Outer brush member 937 may be supported by a brush support member 939 . Multi-functional electric brush 900 is advantageously suitable for cleaning tooth surfaces, and particularly for cleaning tooth surfaces in areas of the mouth that are difficult to reach, including interdental regions and spaces.
[0062] FIG. 10 is a perspective view of a multi-functional electric brush 1000 , according to an embodiment of the present invention. Multi-functional electric brush 1000 has a body 1001 . Body 1001 contains or supports a drive system (not shown).
[0063] Body 1001 is connected to a neck 1021 at a first end of neck 1021 . A head 1031 is connected to a second end of neck 1021 . Body 1001 may define an opening for access to the drive system. A first button, switch, or other now known or later developed actuating mechanism 1023 may be included at an end of body 1001 as shown in FIG. 10 . Switch 1023 may be configured to power a drive system of multi-functional electric brush 1000 on and off. A second button, switch, or other now known or later developed actuating mechanism 1025 may be connected to the drive system and accessible through the opening of body 1001 . Actuating mechanism 1025 may be configured to enable and cause an adjustment of the drive system. For example, actuating mechanism 1025 may facilitate turning multi-functional electric brush 1000 on and off and adjusting a speed of the drive system.
[0064] Drive member 1007 may be flexible to accommodate angled extension from body 1001 to a brush assembly 1031 . In some embodiments, the angle may be about 20 degrees. The brush assembly may include an interdental cleaning member 1035 and an outer brush member 1037 . Outer brush member 1037 may be configured to form a ring defining a central opening, and interdental cleaning member 1035 may be disposed for movement inside the ring in a direction substantially perpendicular to a direction of rotation of outer brush member 1037 . Outer brush member 1037 is supported by a brush support member 1039 . Multi-functional electric brush 1000 is advantageously suitable for cleaning tooth surfaces, and particularly for cleaning tooth surfaces in areas of the mouth that are difficult to reach, including interdental regions and spaces.
[0065] FIG. 11 is an end view of a multi-functional electric brush 1100 , according to an embodiment of the present invention. Multi-functional electric brush 1100 includes a body 1101 . Body 1101 contains or supports a drive system (not shown).
[0066] Body 1101 is connected to a neck 1121 at a first end of neck 1121 . A head 1131 may be connected to a second end of neck 1121 . As shown in FIG. 11 , body 1101 and neck 1121 may have a unitary construction where body 1101 , neck 1121 , and brush assembly 1131 form a substantially unitary construction. For example, portions of body 1101 , neck 1121 , and brush assembly 1131 may be formed from a single material.
[0067] A first button, switch, or other now known or later developed actuating mechanism 1123 may be included at an end of body 1101 as shown in FIG. 11 . Switch 1123 may be configured to power a drive system of multi-functional electric brush 1100 on and off. A second button, switch, or other now known or later developed actuating mechanism 1125 may be connected to the drive system and accessible from an outer portion of body 1101 .
[0068] Actuating mechanism 1125 may be configured to enable and cause an adjustment of the drive system. For example, actuating mechanism 1125 may facilitate turning multi-functional electric brush 1100 on and off and adjusting a speed of the drive system. In some embodiments, the drive system may be connected to a variable speed motor (not shown). The motor and actuating mechanism 1125 may be configured for variable speed adjustment of the motor, and thus variable speed adjustment of the drive system.
[0069] Drive member 1107 may be flexible to accommodate angled extension from body 1101 to a brush assembly 1131 . In some embodiments, the angle may be about 20 degrees. The brush assembly may include an interdental cleaning member (not visible) and an outer brush member 1137 . Outer brush member 1137 may be configured to form a ring defining a central opening, and the interdental cleaning member may be disposed for movement inside the ring in a direction substantially perpendicular to a direction of rotation of brush member 1137 . Outer brush member 1137 may be supported by a brush support member 1139 . Multi-functional electric brush 1100 is advantageously suitable for cleaning tooth surfaces, and particularly for cleaning tooth surfaces in areas of the mouth that are difficult to reach, including interdental regions and spaces.
[0070] FIG. 12 is a side view of a multi-functional electric brush 1200 , according to an embodiment of the present invention. Multi-functional electric brush 1200 has a body 1201 . Body 1201 contains or supports a drive system. The drive system includes a drive member 1207 . The drive member 1207 may be a flexible shaft, for example.
[0071] Body 1201 is connected to a neck 1221 at a first end of neck 1221 . A brush assembly is connected to a second end of neck 1221 . Body 1201 may define an opening for access to the drive system. A first button, switch, or other now known or later developed actuating mechanism 1223 may be connected to the drive system and accessible through the opening of body 1201 . A second button, switch, or other now known or later developed actuating mechanism 1225 may be connected to the drive system and accessible through the opening of body 1201 . Actuating mechanism 1225 may be configured to enable and cause an adjustment of the drive system. For example, actuating mechanism 1225 may facilitate turning multi-functional electric brush 1200 on and off and adjusting a speed of the drive system. Drive member 1221 may be flexible to accommodate angled extension from body 1201 to the brush assembly. In some embodiments, the angle may be about 20 degrees.
[0072] FIG. 13 is an exploded view of a brush assembly 1300 , according to an embodiment of the present invention. Brush assembly 1331 includes an interdental cleaning member 1335 and an outer brush member 1337 . Outer brush member 1337 may be configured to form a ring defining a central opening, and interdental cleaning member 1335 may be disposed for movement inside the ring in a direction substantially perpendicular to a direction of rotation of outer brush member 1337 .
[0073] Outer brush member 1337 may be supported by a brush support member 1339 . The drive member may be contained or supported within a drive shaft defined by the neck. The drive member may be connected at a second end to a crankshaft assembly having a brush assembly support gear 1341 and a drive member gear 1345 . Drive member gear 1345 may be attached to and rotated by the drive member. Drive member gear 1345 may be configured to interlock with and cause rotation of brush assembly support gear 1341 .
[0074] The second end of the drive member may be attached to an offset connecting rod. The connecting rod may be associated with a ball and socket assembly 1347 . The ball and socket assembly may connected to an interdental cleaning member 1335 , and may be configured to cause the interdental cleaning member to move up and down in a direction perpendicular to direction of rotation of the drive member as the drive member rotates.
[0075] Brush support member 1339 may be connected to brush assembly gear 1341 . When the drive member is rotated, drive member gear 1345 rotates brush assembly gear 1341 , thus rotating outer brush 1337 attached to brush support 1339 . Meanwhile, the rotating drive member moves the connecting rod and ball and socket assembly to cause pulsing movement of interdental cleaning member 1335 through the central opening of outer brush 1337 . In some embodiments, interdental cleaning member 1335 may also be connected to brush assembly gear 1341 to enable rotation of cleaning member 1335 during the pulsing. For example, when a gear ratio of brush assembly gear 1341 and drive member gear 1345 is 1:2, the interdental brush may rotate at the same speed as outer brush 1337 , and pulse in a direction perpendicular to a direction of rotation at a speed of about twice that of the speed of rotation of interdental brush 1335 . Accordingly, such a multi-function brush advantageously enables simultaneous cleaning of flat tooth surfaces and interdental spaces.
[0076] FIG. 14 is a top view of a brush assembly 1400 , according to an embodiment of the present invention. Brush assembly 1400 includes a centrally disposed interdental cleaning member 1435 . Interdental cleaning member 1435 is configured to rotate and pulse within the opening defined by an outer brush 1437 . Outer brush 1437 may be attached to and supported by a brush support 1439 . Interdental cleaning member 1435 may be configured to meet support member 1439 to cause rotation of interdental cleaning member 1435 as support member 1439 rotates.
[0077] FIG. 15 is a cross-sectional end view of a head 1500 of a multi-functional electric brush, according to an embodiment of the present invention. Head 1500 includes an interdental cleaning member 1535 and an outer brush member 1537 . Outer brush member 1537 may be configured to form a ring defining a central opening, and interdental cleaning member 1535 may be disposed for movement inside the ring in a direction substantially perpendicular to a direction of rotation of brush member 1537 .
[0078] Outer brush member 1537 may be supported by a brush support member 1539 . The drive member may be contained or supported within a drive shaft defined by the neck. The drive member may be connected at a second end to a crankshaft assembly having a brush assembly support gear 1541 and a drive member gear 1545 . Drive member gear 1545 may be attached to and rotated by the drive member. Drive member gear 1545 may be configured to interlock with and cause rotation of brush assembly support gear 1541 .
[0079] The second end of the drive member may be attached to an offset connecting rod. The connecting rod may be associated with a ball and socket assembly 1547 . The ball and socket assembly may connected to an interdental cleaning member 1535 , and may be configured to cause the interdental cleaning member to move up and down in a direction perpendicular to direction of rotation of the drive member as the drive member rotates.
[0080] Brush support member 1539 may be connected to brush assembly gear 1541 . When the drive member is rotated, drive member gear 1545 rotates brush assembly gear 1541 , thus rotating outer brush 1537 attached to brush support 1539 . Meanwhile, the rotating drive member moves the connecting rod and ball and socket assembly to cause pulsing movement of interdental cleaning member 1535 through the central opening of outer brush 1537 . In some embodiments, interdental cleaning member 1535 may also be connected to brush assembly gear 1541 to enable rotation of cleaning member 1535 during the pulsing. For example, when a gear ratio of brush assembly gear 1541 and drive member gear 1545 is 1:2, the interdental brush may rotate at a same speed as outer brush 1537 , and pulse in a direction perpendicular to a direction of rotation at a speed of about twice that of the speed of rotation of interdental brush 1535 . Accordingly, such a multi-function brush advantageously enables simultaneous cleaning of flat tooth surfaces and interdental spaces.
[0081] FIGS. 16A-C are perspective views of a head 1600 of a multi-functional electric brush with an interdental member in different positions, according to an embodiment of the present invention. Head 1600 includes an interdental cleaning member 1635 and an outer brush member 1637 . Outer brush member 1637 may be configured to form a ring defining a central opening, and interdental cleaning member 1635 may be disposed for movement inside the ring in a direction substantially perpendicular to a direction of rotation of outer brush member 1637 .
[0082] Outer brush member 1637 may be supported by a brush support member 1639 . The drive member may be contained or supported within a drive shaft defined by the neck. The drive member may be connected at a second end to a crankshaft assembly having a brush assembly support gear 1641 and a drive member gear 1645 . Drive member gear 1645 may be attached to and rotated by the drive member. Drive member gear 1645 may be configured to interlock with and cause rotation of brush assembly support gear 1641 .
[0083] The second end of the drive member may be attached to an offset connecting rod. The connecting rod may be associated with a ball and socket assembly 1647 . The ball and socket assembly may connected to interdental cleaning member 1635 , and may be configured to cause interdental cleaning member 1635 to move up and down in a direction perpendicular to direction of rotation of the drive member as the drive member rotates. In FIG. 16A , interdental cleaning member 1635 is obscured by outer brush 1637 . Interdental cleaning member 1635 is in a first position where ball and socket assembly 1647 supports interdental cleaning member 1635 in a position that is lower than a top operating surface of outer brush 1637 . In FIG. 16B , interdental cleaning member 1635 is located at a second position that is about midway between the first non-extended position shown in FIG. 16A and a third position shown in FIG. 16C , where interdental cleaning member 1635 is substantially fully extended and is positioned beyond an operating surface of outer brush 1637 .
[0084] Brush support member 1639 may be connected to a brush assembly gear 1641 . When the drive member is rotated, the drive member gear is caused to rotate brush assembly gear 1641 , thus rotating the outer brush 1637 attached to brush support 1639 . Meanwhile, the rotating drive member moves the connecting rod and ball and socket assembly to cause pulsing movement of interdental cleaning member 1635 through the central opening of the outer brush 1637 . In some embodiments, interdental cleaning member 1635 may also be connected to brush assembly gear 1641 to enable rotation of the cleaning member during the pulsing. For example, when a gear ratio of brush assembly gear 1641 and drive member gear 1645 is 1:2, interdental cleaning member 1635 may rotate at a same speed as outer brush 1637 , and pulse in a direction perpendicular to a direction of rotation at a speed of about twice that of the speed of rotation of interdental cleaning member 1635 . Accordingly, such a multi-function brush advantageously enables simultaneous cleaning of flat tooth surfaces and interdental spaces.
[0085] Accordingly, the multi-function brush in accordance with some embodiments advantageously enables simultaneous cleaning of flat tooth surfaces and interdental spaces. The combined operable surface area of the interdental cleaning member and the outer brush may enhance cleaning of tooth surfaces. For example, the combination of the interdental cleaning member and the outer brush may form a total operable surface area that is 50% larger than an operable surface area of the outer brush alone. Further, the multi-function brush in accordance with some embodiments may be useful for many applications, including pedodontal, and orthodontic applications.
[0086] The multi-function brush in accordance with some embodiments may be useful for periodontal applications, and may enable enhanced cleaning under the gumline. For example, the multi-function brush in accordance with some embodiments may include an interdental cleaning member that is configured to reach about 3 to 5 millimeters below the gumline for cleaning. The multifunction brush in accordance with some embodiments may enable cleaning at about 5 millimeters below the gumline. The interdental cleaning member and the outer brush may combine to form a top operable cleaning surface that enables enhanced cleaning functionality.
[0087] It will be readily understood that the components of various embodiments of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the detailed description of the embodiments of the systems, apparatus, and methods of the present invention, as represented in the attached figures, is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention.
[0088] The features, structures, or characteristics of the invention described throughout this specification may be combined in any suitable manner in one or more embodiments. For example, reference throughout this specification to “certain embodiments,” “some embodiments,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in certain embodiments,” “in some embodiment,” “in other embodiments,” or similar language throughout this specification do not necessarily all refer to the same group of embodiments and the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
[0089] The modifiers “about” and “approximately” used in connection with a quantity are inclusive of the stated value and have the meaning dictated by the context. For example, it includes at least the degree of error associated with the measurement of the particular quantity. When used with a specific value, they also disclose that value.
[0090] It should be noted that reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present invention should be or are in any single embodiment of the invention. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, discussion of the features and advantages, and similar language, throughout this specification may, but do not necessarily, refer to the same embodiment.
[0091] Furthermore, the described features, advantages, and characteristics of the invention may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the invention can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention.
[0092] One having ordinary skill in the art will readily understand that the invention as discussed above may be practiced with steps in a different order, and/or with hardware elements in configurations which are different than those which are disclosed. Therefore, although the invention has been described based upon these preferred embodiments, it would be apparent to those of skill in the art that certain modifications, variations, and alternative constructions would be apparent, while remaining within the spirit and scope of the invention. In order to determine the metes and bounds of the invention, therefore, reference should be made to the appended claims. | A powered dental and interdental cleaning tool may include a body, an interdental cleaning member, and a drive member. The drive member may extend from the body at an angle to a longitudinal axis of the body. The drive member may be connected to the interdental cleaning member. A neck may extend from the body and define a drive member shaft for containing and supporting the drive member. | 0 |
FIELD OF THE INVENTION
[0001] The invention relates to the field of lighting devices and more specifically to configurable lighting devices.
SUMMARY OF THE INVENTION
[0002] It would be advantageous to provide a lighting device that has a variable configuration, it would also be desirable to enable a user to adjust the variable configuration of the lighting device. To better address one or more of these concerns, in a first aspect of the invention a lighting device is presented that comprises;
a first part, a second part which is flexibly connected to the first part so that the lighting device can be in at least two configurations, a sensor for detecting the configuration of the lighting device, each of the first and second parts comprises a first and a second light source, the first light source is for emitting light in a first direction and the second light source is for emitting light in a second direction different to the first direction, and a controller for controlling the light sources, and wherein the sensor output is fed to the controller, and based on the sensor output the controller selectively powers either the first light sources, second light sources or a combination of the first and second light sources.
[0009] A method of controlling the lighting device is also provided.
[0010] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Examples of the invention will now be described in detail with reference to the accompanying drawings, in which;
[0012] FIG. 1 shows an embodiment of a lighting device in a minimally curved configuration,
[0013] FIG. 2 shows an embodiment of a lighting device in a curved configuration,
[0014] FIG. 3 shows an embodiment of a lighting device in a linear configuration,
[0015] FIG. 4 shows an embodiment of a tube that may be used in a lighting device,
[0016] FIG. 5 shows a visualisation of a ray trace of light emitted by a first light source located within a tube that may be used in a lighting device.
DETAILED DESCRIPTION OF EMBODIMENTS
[0017] FIG. 1 shows an embodiment of a lighting device 1 . In this embodiment the first and second parts comprise tubes 2 . The lighting device 1 has an inner surface 3 for emitting light and an outer surface 4 for emitting light. A light source (not shown), a sensor (not shown), and a controller (not shown) are provided to emit light of a desired color, color temperature or intensity based on the sensor output which in turn is based on the configuration of the lighting device 1 .
[0018] FIG. 2 shows an embodiment of a lighting device 1 in a curved configuration. This curvature may be configured by the user of the lamp. It can be seen from the figure that the lighting device 1 has been curved around so that the ends of the lighting device overlap. The intensity, color or color temperature of the light emitted by the first light sources through the inner surface 3 may be adjusted by the controller based on the configuration of the lighting device 1 that the user has configured. The intensity, color or color temperature of the light emitted by the second light sources through the outer surface 4 of the lighting device 1 may also be adjusted by the controller based on the configuration of the lighting device 1 that the user has configured. This adjustment of the light emitted by the second light sources through the outer surface 4 may be carried out simultaneously with an adjustment of the light emitted by the first light sources through the inner surface 3 , it may be separate or the adjustments may overlap. The first light sources and the second light sources may emit light in a pattern controlled by the controller.
[0019] FIG. 3 shows an embodiment of a lighting device 1 in a linear configuration. The inner surface 3 may emit light of a desired intensity, color or colour temperature. A sensor 7 detects the configuration of the lighting device 1 . A sensor that may be suitable for detecting the configuration of the lighting device 1 is a strain gauge.
[0020] A common type of strain gauge consists of an insulated backing which supports a metallic foil pattern. The gauge is attached between the first part and the second part of the lighting device 1 by a suitable adhesive, such as cyanoacrylate. As the parts are configured, the foil is deformed, causing its electrical resistance to change.
[0021] A strain gauge takes advantage of the physical property of electrical conductance and its dependence on the conductor's geometry. When an electrical conductor is stretched within the limits of its elasticity such that it does not break or permanently deform, it will become narrower and longer, these are changes that increase its electrical resistance end-to-end. Conversely, when a conductor is compressed such that it does not buckle, it will broaden and shorten; these are changes that decrease its electrical resistance end-to-end. From the measured electrical resistance of the strain gauge, the amount of applied stress may be inferred.
[0022] A typical strain gauge arranges a long, thin conductive strip in a zig-zag pattern of parallel lines such that a small amount of stress in the direction of the orientation of the parallel lines results in a magnified strain measurement over the effective length of the conductor surfaces in the array of conductive lines; and thus a magnified change in resistance, than would be observed with a single straight-line conductive wire.
[0023] An excitation voltage is applied to input leads of the gauge network, This voltage can be provided by the controller within the lighting device 1 or it may be a separate internal or external voltage source, such as for example a battery. Once the voltage is applied to the input, a voltage reading is taken from the output leads. Typical input voltages are 5 V or 12 V and typical output readings are in millivolts.
[0024] Foil strain gauges are used in many situations. Different applications place different requirements on the gauge. In most cases the orientation of the strain gauge is significant.
[0025] Gauges attached to a load cell would normally be expected to remain stable over a period of years, if not decades; while those used to measure response in a dynamic experiment may only need to remain attached to the object for a few days, be energized for less than an hour, and operate for less than a second. The lifetime of the strain gauge within the lighting device 1 should be comparable to the lifetime of the first and second light sources.
[0026] Strain gauges are attached to the substrate with glue. The type of glue depends on the required lifetime of the measurement system. For short term measurements (up to some weeks) cyanoacrylic glue is appropriate, for long lasting installation epoxy glue is required. Usually epoxy glue requires high temperature curing (at about 80-100° C.). The preparation of the surface where the strain gauge is to be glued is of the utmost importance. The surface must be smoothed (e.g. with very fine sand paper), de-oiled with solvents, the solvent traces must then be removed and the strain gauge must be glued immediately after this to avoid oxidation or pollution of the prepared area. If these steps are not followed the strain gauge binding to the surface may be unreliable and unpredictable measurement errors may be generated.
[0027] Capacitive strain gauges use a variable capacitor to indicate the level of mechanical deformation
[0028] For measurements of small strain, semiconductor strain gauges, so called piezoresistors, are often preferred over foil gauges. A semiconductor gauge usually has a larger gauge factor than a foil gauge. Semiconductor gauges tend to be more expensive, more sensitive to temperature changes, and are more fragile than foil gauges.
[0029] Nanoparticle-based strain gauges are emerging as a new promising technology. These resistive sensors whose active area is made by an assembly of conductive gold nanoparticles combine a high gauge factor, a large deformation range and a small electrical consumption due to their high impedance.
[0030] Another way of detecting the curvature of the lighting device is 1 to use optical sensors 7 utilising time of flight measurements. If at least three sensors 7 are used, one at each end of the lighting device 1 and the third in the centre, it is possible to calculate the relative positions of the ends of the lighting device 1 compared with the centre using the principle of triangulation. This is possible because the positions of the sensors 7 are known when the lighting device 1 is manufactured and so if calibrated correctly, i.e. when the lighting device 1 is in a known position and the distances between the sensors 7 can be accurately measured the system can prove to be robust.
[0031] An embodiment of the first and second light sources utilizes LED strips. An LED Strip Light (also known as an LED tape or ribbon light) is a flexible strip of surface mounted light-emitting diodes that usually comes with an adhesive backing. This allows for swift and secure location during manufacturing, obviously other fixing methods as known to the person skilled in the art may be employed instead.
[0032] The LED strip may be produced with different characteristics, i.e, intensity, color temperature or indeed full RGB color changing. The LED strip may be provided with an individual control chip located next to each LED, or one chip is provided per strip in each of the plurality of parts within the multi-part luminaire, or it may be that the control of the LEDs is provided solely by the main controller within the multi-part luminaire. Any combination that proves advantageous may be utilised too.
[0033] The most simple type of LED strip is a single color, non-addressable LED strip. Every LED in the strip is a single white colour, typically ranging from 2700K to 6500K in colour temperature.
[0034] A single chip address all of the LEDs in the strand at once so each setting is applied to every LED.
[0035] A RGB, non-addressable LED strip is more complex, the RGB LEDS can output multiple colors but the entire strand uses the same address so all LEDs within that strip show the same color.
[0036] Addressable LED strips have an individual chip per LED, these allow tuning of intensity and/or color temperature per LED in the case of white LEDs or full color control and/or intensity per RGB LED. Further light effects such as chasing or strobing etc are possible as each LED is controlled by a dedicated chip.
[0037] The lighting device 1 may be suitable for use in an external environment such as, for example, a garden. This can be achieved by using a water resistant LED light strip.
[0038] Water resistant LED strips are covered in a heat conducting epoxy to protect the circuitry from direct contact with water.
[0039] The LED strips typically operate on 12 or 24 volts of direct current provided in this case by the controller. USB strip lights operate on the standard 5-volt direct current used by USB devices.
[0040] The user may configure the curvature of the lighting device 1 in order to fulfil aesthetic requirements or the tailoring of the light output. When the lighting device 1 has a minimum curvature, i.e. when it is substantially linear, the inner surface 3 of the lighting device 1 may transmit light with a higher intensity than when the curvature is more pronounced. The controller within the lighting device 1 may be configured to adjust a property of the light emitted by the first light sources and/or the second light sources based on the output from the sensor 7 . The sensor 7 detects the configuration of the lighting device 1 and outputs a sensor signal, for example, a voltage based on the amount of curvature sensed.
[0041] The controller receives this sensor signal and then calculates the required light properties based on a predetermined algorithm. The controller may increase the intensity of the light emitted by the first light sources as the lighting device 1 is uncurled by the user. The controller may alternatively decrease the intensity of the light emitted by the first light sources as the user uncurls the lighting device 1 .
[0042] In a further embodiment, the first light sources may comprise RGB LEDs, the color may be changed by the controller based on the configuration of the lighting device 1 . For example, the RGB LEDs may emit a red light once a predetermined curvature has been exceeded, that is to say, if the user straightens the lighting device, once a certain minimum curvature threshold has been reached, the RGB LEDs may be controlled to emit red light.
[0043] In a further embodiment, the RGB LEDs may be controlled to start producing a light effect, for example a rolling change of color when a predetermined minimum curvature threshold has been exceeded. The RGB light sources up until this minimum curvature may have been emitting white light. Alternatively, the colour effect may be emitted until the minimum curvature threshold has been reached and then, when exceeded, the first light sources may emit white light.
[0044] In a yet further embodiment, the second light sources may be controlled to change the light intensity and/or light color emitted by the second light source. This may be based, as for the first light sources, on a change in the configuration of the lighting device 1 , for example, a curvature of the lighting device 1 that has been adjusted by the user.
[0045] In a further embodiment the controller may be configured to reduce the intensity of the light emitted by the second light sources and to simultaneously control the first light sources to emit white light once a predetermined minimum curvature threshold has been exceeded. This may prove advantageous in both reducing the electrical load drawn by the lighting device 1 or in decreasing the thermal load generated by the combination of the first light sources and the second light sources. This may be an advantage when the plurality of parts within the lighting device 1 reduce in size, or it may bring economic benefits as smaller heat sinks for the LEDs may be required.
[0000] In a further embodiment, the controller may progressively increase the intensity of the white light emitted by the first light sources based on a decrease in the curvature of the luminaire once a predetermined minimum curvature threshold has been reached.
[0046] FIG. 4 shows an embodiment of a tube 2 that may be used in a lighting device 1 . The first and second parts comprise of tubes 2 . These tubes 2 may comprise at least a portion of their surface area being diffusely transmissive. The tubes 2 may be arranged in a vertical orientation with first light sources and second light sources being housed inside each tube 2 .
[0047] The tubes 2 may be flexibly joined along their length to one another to enable a user configurable lighting device 1 to be manufactured. The tubes 2 may be all the same length or they may vary in length. A variation of length of tubes 2 may prove to be an aesthetic advantage. The variation may be symmetrical around the vertical axis located at the midpoint of the lighting device 1 , it may be asymmetric or it may be random or any other pattern that is desired.
[0048] FIG. 5 shows a visualisation of a ray trace 6 of light emitted by a first light source 5 located within a tube 2 that may be used in a lighting device 1 . The first light source 5 emits light along an optical axis towards the wall 8 of the tube 2 opposite the first light source. The ray trace of the second light source and the second light source itself are not shown in the interests of clarity.
[0049] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. | A lighting device (1) is provided. The light device ( 1 ) comprises a first part ( 2 ) and a second part ( 2 ) which is flexibly connected to the first part ( 2 ) so that the lighting device ( 1 ) can be in at least two configurations. There is a sensor ( 7 ) which detects the configuration of the lighting device ( 1 ) and a controller for receiving the sensor signal from the sensor ( 7 ) and for providing an output to first light sources and second light sources. | 5 |
BACKGROUND
[0001] 1. Technical Field
[0002] This invention relates in general to shopping carts, and more particularly it relates to antitheft devices for use with shopping carts.
[0003] 2. Background of the Invention
[0004] Most individuals use shopping carts in a variety of commercial applications, including grocery stores, drug stores, discount stores, wholesale stores, home and garden stores, or any other environment that requires a conventional shopping cart. A substantial majority of all shopping carts typically contain a pivoting rear wall which, when extended, provides an upper shelf near the handle that allows items such as handbags to be stored while shopping.
[0005] For women shoppers, conventional shopping carts present a theft hazard because a handbag or other valuable item might be stolen while the shopper is distracted looking at inventory items on shelves, counters, etc. It would be desirable to have a method of protecting customer valuables while the customer's attention is directed away from their valuables to items on shelves, etc.
[0006] Further, it would be desirable to have a device that could not only be provided to a new shopping cart during the manufacturing process, but also can be provided as an add-on feature for pre-existing shopping carts. In either case, whether the device is factory pre-installed, or an after market device, it would be desirable that the device not interfere or prevent the stacking of shopping carts at the merchant's place of business.
[0007] Another advantage on the consumer would be to have a detachable antitheft device that the customer could own and attach to a variety of shopping cart sizes and configurations.
[0008] While the prior art has provided a basic raised platform for holding valuable or personal items, it has failed to provide a secure antitheft mechanism that can be attached to a shopping cart such that the shopping cart is provided with secure storage for valuables while the customer is shopping.
SUMMARY OF THE INVENTION
[0009] This invention provides a permanently attached, or detachable security lid that converts the upper shopping cart storage area into an enclosed secure storage area for valuables. The lid can be rigid, and besides to fit one or more shopping cart types, and alternatively, it can be fabricated from foldable or flexible materials that allow it to be carried in the handbag of a customer. It has a variety of optional attachment devices that secure it to a conventional shopping cart.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a perspective view of a prior art shopping cart.
[0011] FIG. 2A is a top plan view of a preferred embodiment of the security lid.
[0012] FIG. 2B is an end view of the security lid that illustrates the outer bracket with a rod that has an attachment hook extending from it.
[0013] FIG. 2C illustrates an end view of the security lid that shows the bracket and the rotatable hook.
[0014] FIG. 3 shows a perspective view of a preferred embodiment of a security lid secured to a conventional shopping cart in the closed position.
[0015] FIG. 4 shows a perspective view of a preferred embodiment of a security lid secured to a conventional shopping cart in the open position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0016] Prior to a discussion of the figures, an overview of the invention will be presented. The invention provides a security lid for an upper shopping cart storage area that can be fabricated as part of the shopping cart, or alternatively, fabricated as an independent add-on device that a business can attach to its shopping carts, or fabricated as a detachable security lid that a customer can attach to a shopping cart. The detachable embodiment of the security lid can be provided by the merchant or be a security lid owned by the customer who brings it to the merchant's location in the event that the merchant does not provide a security lid.
[0017] The security lid can be fabricated from any suitable material, such as metal, wire, cloth, wood, synthetic material (e.g., nylon, polyethylene, etc.). Likewise, it can be fabricated as a rigid or flexible/foldable security lid.
[0018] The security lid transforms the upper shopping cart storage area into a secure enclosed area and allows the customer to divert their attention to items on the shelf without worrying about potential theft.
[0019] An advantage of the invention is that it is inexpensive to manufacture, it can be made as an integral part of the shopping cart or as an add-on, and it a) enhances the customer's enjoyment of the shopping experience by reducing anxiety over potential theft, and b) may prevent actual theft.
[0020] Having discussed the invention in general, we turn now to a detailed discussion of the drawings.
[0021] Regarding FIG. 1 , this figure is a perspective view of a conventional shopping cart 1 . This view also shows the fixed rear wall 4 and the pivoting rear wall 2 in the open position. When the pivoting rear wall 2 is moved to the open position, an upper shopping cart storage area 3 is made available for use by the customer. Typically, a shopper would place her purse, or perhaps other valuable items, in the upper shopping cart storage area 3 while shopping. Unfortunately, purses or other valuable items in the upper shopping cart storage area 3 are left exposed. As the shopper selects or examines merchandise, her attention is frequently diverted from the shopping cart to items on the merchant's shelf. When this happens, a thief is provided an opportunity to steal the handbag, or something within it, such as a wallet.
[0022] Also shown in this figure is attachment bar 10 . A typical shopping cart will have one or more horizontal bars across the fixed rear wall 4 . Any of these horizontal bars can be used as the attachment bar 10 that will be used to secure the security lid 9 in place (security lid 9 is discussed in more detail below in regard to FIGS. 2-3 ). The actual attachment bar 10 that is used will be selected based on how suitably it aligns with the security lid 9 to form the enclosed area formed by the security lid 9 .
[0023] FIG. 2A is a top plan view of a preferred embodiment of the security lid 9 . This can be seen in this figure, there is an outer bracket 5 that supports a plurality of rods 6 . In the preferred embodiment, the distance between the rods 6 can vary so long as the distance is not so great as to allow a thief to slip a hand between the rods 6 or to allow an item such as a wallet to be slipped out between the rods 6 .
[0024] Also shown in this figure are rods 6 that have attachment hooks 7 formed at one end. Attachment hooks 7 are sized such that they can engage any conveniently located attachment point on a shopping cart 1 . Finally, rotatable hooks 8 are illustrated. In practice, the security lid 9 is stored in an open position when not in use such that the upper shopping cart storage area 3 can be accessed to remove or insert any item, such as a handbag. Typically, while the security lid 9 will preferably lay flat against the pivoting rear wall 2 when in the open position, those skilled in the art will recognize that the security lid 9 can alternatively be configured such that it can be secured to the fixed rear wall 4 of the shopping cart 1 .
[0025] In the preferred embodiment, the rotatable hooks 8 are attached to the pivoting rear wall 2 . In the open position, the security lid 9 will preferably rest flat against the pivoting rear wall 2 . When in the closed position, the rotatable hooks 8 attach the security lid 9 to the pivoting rear wall 2 and the attachment hooks 7 are secured to the fixed rear wall 4 of the shopping cart 1 such that items in the upper shopping cart storage area 3 are securely enclosed. When securing the upper shopping cart storage area 3 , the security lid 9 is held up by the customer and the pivoting rear wall 2 is moved toward the fixed rear wall 4 a sufficient distance to allow attachment hooks 7 to slide over a preselected rod in the fixed rear wall 4 . Then the pivoting rear wall 2 is released and gravity pulls the pivoting rear wall 2 back such that the attachment hooks 7 engage the preselected rod in the fixed rear wall 4 .
[0026] Prior art shopping carts typically have plastic seats in the upper shopping cart storage area 3 that flip down to allow a comfortable seat for children. When the security lid 9 is used, the plastic seats would preferably be flipped up to block the child's leg openings in the fixed rear wall 4 of the shopping cart 1 , then the purse or other item would be placed in the secure compartment. After that, the security lid 9 is attached to fixed rear wall 4 and the purse is safely secured inside the shopping cart 1 .
[0027] FIG. 2B is an end view of the security lid 9 that illustrates the outer bracket 5 with a rod 6 with an attachment hook 7 attached thereto. Those skilled in the art will recognize that any suitable materials may be used to fabricate the security lid 9 . For example, metal, plastics, etc. In the case of metals, the outer bracket 5 and the rods 6 may be welded together. Further, fabrication from plastics or other materials will allow the bracket 5 and rods 6 to be fashioned as a single piece via a molding process.
[0028] FIG. 2C illustrates an end view of the security lid 9 that shows the bracket 5 and a rotatable hook 8 . The rotatable hook 8 can be fabricated such that it can be removably or permanently attached to the pivoting rear wall 2 of the shopping cart 1 .
[0029] For ease of discussion, the security lid 9 was discussed in terms of a rigid device. However, those skilled in the art will recognize that security lid 9 can also be implemented as a flexible device. For example, it can be fabricated from canvas, cloth, netting, etc. An alternative embodiment envisions a flexible security lid 9 that can be permanently attached to a shopping cart 1 , or detachably attached to the shopping cart 1 . A security lid 9 fabricated from flexible material provides an additional advantage in that a consumer can fold it up and carry it in a purse, a car glove compartment, etc. When the consumer visits a merchant location, the consumer's security lid 9 can be used with the merchant's shopping cart 1 , even though the merchant's business may not provide security lids 9 on their shopping carts. This gives the consumer the independence to use the security lid 9 anywhere that uses shopping carts 1 .
[0030] Another example of using a flexible security lid 9 is that it can be fabricated from stretchable material. This allows the consumer to attach the security lid 9 to shopping carts 1 that have different sizes.
[0031] FIG. 3 shows a perspective view of the security lid 9 secured to a conventional shopping cart 1 . This figure illustrates the closed position in which a valuable such as a purse can be safely secured within the upper shopping cart storage area 3 . As illustrated, security lid 9 is attached to pivoting rear wall 2 via rotatable hooks 8 and secured to fixed rear wall 4 via attachment hooks 7 .
[0032] FIG. 4 shows a perspective view of the security lid 9 secured to a conventional shopping cart 1 . This figure illustrates the open position in which the upper shopping cart storage area 3 is accessible. As illustrated, security lid 9 is attached to pivoting rear wall 2 via rotatable hooks 8 . Attachment hooks 7 are unattached to fixed rear wall 4 in the open position. Also, the security lid 9 rests flat against pivoting rear wall 2 in this position. As a result, this allows a child to comfortably sit in the upper shopping cart storage area 3 . Further, this allows multiple shopping carts 1 to be stacked together in the conventional manner.
[0033] For ease of illustration, this figure shows the security lid 9 positioned such that it extends upward from the shopping cart 1 in the open position. However, those skilled in the art will recognize that the security lid 9 can just as easily hang downward such that it rests substantially flat against the pivoting rear wall 4 of the shopping cart 1 .
[0034] While specific embodiments have been discussed to illustrate the invention, it will be understood by those skilled in the art that variations in the embodiments can be made without departing from the spirit of the invention. For example, changes in material can be made, the dimensions of the security lid can change, the method used to secure the security lid to the shopping cart can change, etc. Therefore, the invention shall be limited solely to the scope of the claims. | A security lid that converts the upper shopping cart storage area into an enclosed secure storage area for valuables. The lid can be rigid, and sized to fit one or more shopping cart types, and alternatively, it can be fabricated from foldable or flexible materials that allow it to be carried in the handbag of a customer. It has a variety of optional attachment devices that secure it to a conventional shopping cart. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of PCT International Application No. PCT/US01/27659, filed Sep. 7, 2001 and U.S. patent application Ser. No. 09/658,539, filed Sep. 9, 2000.
BACKGROUND OF THE INVENTION
The present invention relates in general to improving the determination of wheel speed for electronically-controlled vehicular braking systems, and, more specifically, to using suspension system information and a suspension system model to determine instantaneous wheel rolling radius for improved wheel speed calculation.
Electronically-controlled active vehicular braking systems include anti-lock braking (ABS), traction control (TC), and yaw stability control (YSC) functions. In such braking systems, sensors deliver input signals to an electronic control unit (ECU). The ECU sends output signals to electrically activated devices to apply, hold, and dump (relieve) pressure at wheel brakes of a vehicle. Electrically activated valves and pumps are used to control fluid pressure at the wheel brakes. Such valves and pumps can be mounted in a hydraulic control unit (HCU). The valves typically include two-state (on/off or off/on) solenoid valves and proportional valves.
A basic function of these braking systems is to detect wheel slip (e.g., skidding or loss of traction) and actuate the brakes (or reduce torque from the engine) in a manner to reduce or control wheel slip. An individual wheel speed is measured and wheel slip is detected by 1) comparing the individual wheel speed to the overall speed of the vehicle, and/or 2) monitoring the rate of change in the measured wheel speed. An angular rotation sensor mounted at the wheel produces pulses at a frequency proportional to the velocity at which the wheel spins. Using a predetermined nominal rolling radius of the particular wheel/tire combination, prior art systems convert the angular velocity of the wheel into a longitudinal speed for the particular wheel.
During actual driving conditions, the instantaneous rolling radius at a particular wheel will vary from the predetermined nominal rolling radius due to various forces acting on the tire, such as road undulations and load variations. The changes in rolling radius introduce error or noise into prior art wheel speed determinations. In order to avoid false activations of the braking system, the wheel speed needs to be filtered to remove this noise and/or the activation thresholds desensitized. Therefore, performance could be improved if a more accurate measurement of individual instantaneous wheel speed could be obtained.
Electronically-controlled suspension systems typically include semi-active suspension systems and active suspension systems to provide active damping for a vehicle. In such suspension systems, sensors deliver input signals to an electronic control unit (ECU). The ECU sends output signals to electrically activated devices to control the damping rate of the vehicle. Such devices include actuators to control fluid flow and pressure. The actuators typically include electrically activated valves such as two-state (digital) valves and proportional valves.
SUMMARY OF THE INVENTION
The present invention employs information from a suspension sensor to determine an instantaneous rolling radius for a particular wheel to improve a wheel speed measurement for that wheel.
According to one aspect of the invention, a method is provided for determining longitudinal speed of a vehicle wheel for use in a vehicle slip control system. An instantaneous angular rate of a vehicle wheel is measured via an individual wheel speed sensor. At least one operating characteristic of a portion of a vehicle suspension system associated with the vehicle wheel is measured, the suspension operating characteristic at least in part representative of an instantaneous rolling radius of the vehicle wheel. An instantaneous rolling radius deviation corresponding to the vehicle wheel is determined in response to the suspension operating characteristic. A longitudinal wheel speed signal is generated in response to the instantaneous angular rate and the instantaneous rolling radius deviation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic drawing showing a wheel, tire, and suspension components together with a wheel angular rate sensor and the calculations to determine longitudinal speed.
FIG. 2 is a block diagram showing a prior art braking system.
FIG. 3 is a block diagram showing a preferred embodiment of the wheel speed determination of the present invention.
FIG. 4 is a block diagram showing another preferred embodiment of the wheel speed determination of the present invention.
FIG. 5 is a plot showing an unfiltered wheel speed signal and a comparison of filtered signals between the invention and the prior art.
FIG. 6 is a schematic diagram showing a suspension model used in a preferred embodiment.
FIG. 7 is a block diagram showing another preferred embodiment of the invention.
FIG. 8 is a schematic diagram of an integrated vehicular control system useful in practicing the present invention.
FIG. 9 is a schematic diagram of another embodiment of an integrated vehicular control system.
FIG. 10 is a schematic diagram of yet another embodiment of an integrated vehicular control system.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Turning to FIG. 1. a wheel for one particular corner of a vehicle is shown. A wheel assembly 10 includes a rim 11 and a tire 12 . During smooth, steady state operation at specified conditions (such as specified tire pressure), tire 12 has a certain shape so that the rolling radius of wheel assembly 10 has a nominal radius R 0 . During dynamic driving conditions, however, forces on tire 12 cause it to deform or deflect from its nominal shape resulting in variability of rolling radius. An instantaneous rolling radius R i varies from nominal radius R 0 by a radial deviation ΔR, which may be positive or negative.
Wheel assembly 10 is connected to a suspension system 13 . Associated with wheel assembly 10 are a strut 14 and a spring 15 connected to the vehicle by a strut retainer 16 . A shock absorber 17 is coupled between strut 14 and strut retainer 16 to provide damping. Suspension system 13 may preferably is include an electronic suspension control system (not shown) for adjusting suspension performance (e.g., damping characteristics) in response to various operating characteristics of the suspension, such as strut displacement. A suspension sensor 18 (such as a displacement sensor mounted to a fixed part of the vehicle body or frame) measures at least one such operating characteristic, and may be part of an active suspension control system or may be dedicated for use with the active braking control system.
A toothed-wheel 20 is mounted for rotation with wheel assembly 10 . A sensor 21 is mounted in a fixed location adjacent toothed-wheel 20 and may be a variable reluctance sensor or an optical sensor for generating an electrical pulse signal as known in the art. The resulting pulse signal has a pulse rate determined by the angular rotation rate of toothed-wheel 20 . The period between leading pulse edges corresponds to the difference between times t 1 and t 2 . The pulse frequency can be determined in a frequency calculator 22 as the inverse of the time difference t 2 minus t 1 , or by counting a number of pulse edges detected during a fixed time window, for example. The pulse repetition frequency is multiplied in a multiplier 23 by a conversion factor to produce a longitudinal speed of the wheel. The conversion factor is a constant that relates the angular rotation frequency to a desired speed format (e.g., meters per second, miles per hour, etc.) and assumes a nominal rolling radius R 0 . To the extent that the instantaneous rolling radius R i varies from R 0 , the instantaneous longitudinal speed will be in error.
FIG. 2 shows further details of a prior art slip control system, such as an anti-lock brake (ABS) system, traction control (TC) system, or vehicle stability control (VSC) system, including a physical portion 25 and a control portion 26 . Physical portion 25 includes tire and suspension system 27 which is subjected to road interaction and other forces as the vehicle moves. Based on wheel rim size and nominal tire shape, the rolling radius for any particular vehicle wheel is approximately a nominal rolling radius R 0 . Tire deflection in response to the various forces acting on the tire causes a rolling radius deviation ΔR to be superimposed on the nominal value in a summation 28 . Wheel 29 then spins with an instantaneous rolling radius R i in direct response to the vehicle speed v. Thus, even though the physical wheel 29 is spinning at a rate dependent upon instantaneous rolling radius R i , prior art systems determine wheel speed as though it depended on R 0 .
Control portion 26 includes an angular rotation sensor and calculation block 30 to produce a longitudinal wheel speed signal which is filtered in a lowpass filter 31 . The filtered longitudinal speed is input to a slip detection and correction controller 32 , a vehicle speed estimator 33 , and an acceleration estimator 34 . Estimators 33 and 34 have their outputs coupled to controller 32 . The output of slip detection and correction controller 32 is coupled to brake actuators 35 which are actuated as needed to limit wheel slip.
The variation in rolling radius results in an additive noise in the output of sensor 30 . To avoid false detection of wheel slip and false activation of brake actuators 35 , the sensor output is filtered in lowpass filter 31 to at least partially remove the noise. This technique is partially effective since tire deflections occur with some of their frequencies above the frequencies of interest for slip detection. A cutoff frequency of about 20 Hz is typical for the lowpass filter in the prior art. However, the lowpass filtering also reduces performance when a false detection is not occurring by increasing the time required to detect the slippage.
An improved system is shown in FIG. 3. A sensor and rate calculator 40 provides an instantaneous angular rate signal to one input of a multiplier 41 .
A suspension sensor 43 measures a suspension system operating characteristic and provides a signal to a suspension model 44 . The suspension operating characteristic is at least in part representative of an instantaneous rolling radius of the vehicle wheel. Based on the suspension model, an instantaneous rolling radius deviation ΔR is determined. ΔR is added to the nominal rolling radius R 0 in a summer 45 to produce an instantaneous rolling radius R i . If any particular units are desired for the longitudinal speed signal, a conversion factor can be applied in a conversion block 46 , otherwise, the instantaneous rolling radius signal R i is applied directly to the second input of multiplier 41 . By multiplying the instantaneous angular rate signal and the instantaneous rolling radius, the output of multiplier 41 provides an improved longitudinal speed signal. The output of multiplier 41 is lowpass filtered in a filter 42 and then provided to the slip controller.
An alternative embodiment is shown in FIG. 4 as an add-on to existing systems. While the embodiment of FIG. 3 modifies the initial calculation of longitudinal wheel speed itself, for existing products it may be more convenient to instead apply a correction factor to an existing calculation of wheel speed based on the nominal rolling radius. Since existing products typically implement the filtering and speed calculations digitally in software, it may sometimes be desirable to retain existing software code and to insert a patch that applies a correction factor to the prior art speed signal. Thus, FIG. 4 shows that an angular rate signal from sensor/rate calculator 40 is applied to one input of a multiplier 47 . The nominal rolling radius R 0 is applied to the second input of multiplier 47 , and a speed signal including any error from variation in the instantaneous rolling radius is coupled to a first input of a multiplier 48 . Instantaneous rolling radius deviation ΔR from suspension model 44 is coupled to a correction factor calculator 49 . A correction factor is calculated as the ratio of the actual instantaneous rolling radius R i (determined as the sum of nominal rolling radius R 0 and the instantaneous rolling radius deviation ΔR) to the nominal rolling radius R 0 . Thus, for decreases in instantaneous rolling radius (i.e., ΔR is negative), the correction factor is less than one and a properly reduced longitudinal speed determination is made. For increases in instantaneous rolling radius (i.e., ΔR is positive), the correction factor is greater than one and a properly increased longitudinal speed determination is made. Calculator 49 may include a summer for adding R 0 and ΔR followed by a gain equal to 1/R 0 , for example. The correction factor is coupled to a second input of multiplier 48 and a corrected longitudinal wheel is speed signal at the output of multiplier 48 is coupled to the slip controller through filter 42 .
As a result of the improved accuracy of the longitudinal wheel speed determination, the need for filtering of the speed signal to avoid false activations is greatly reduced. While prior art filters used a typical cutoff frequency of about 20 Hz, the present invention can avoid false activation from remaining sources of random signal error while raising the cutoff frequency to 50 Hz. FIG. 5 shows a raw, unfiltered signal 50 from the angular rate sensor during a deceleration. A filtered signal 51 resulting from the prior art cutoff frequency shows a significant time lag before the deceleration can be detected. In contrast, the higher value of the cutoff frequency for a filtered signal 52 as enabled by the present invention more quickly follows the deceleration. Since the deceleration is more quickly detected, overall performance of the slip control system is greatly improved.
The suspension system model for determining deviation of the rolling radius will be discussed with reference to FIG. 6 . Block 55 represents the sprung mass M s of a vehicle and block 56 the unsprung mass M u . There is a spring constant K s between block 55 and block 56 and a spring constant K t between block 56 and the ground 57 . There is also a damning constant C d between blocks 55 and 56 . The model further includes height Z s of the sprung mass, height Z u of the unsprung mass, and height Z r above terrain.
In a preferred embodiment, the suspension system model is implemented using a Kalman filter. The Kalman filter is designed using the constant coefficient linear time-invariant plant model of FIG. 6 . This assumption potentially reduces the accuracy of the estimation to a small operating region about an equilibrium point. The range of the operating region is dependent on the nonlinear nature of the system. To increase the accuracy over a larger range of the operating region, the extended Kalman filter implementation could be used. However, such design would be computation intensive and not as well suited for RAM/ROM and loop time constrained systems. A Kalman filter is useful is reducing the effects of process disturbances and measurement noise on the estimation process. The fact that the plant model used in the preferred embodiment contains constant coefficients means that the robustness of the estimation is limited to a certain variance in the constants. Therefore, changes in the actual plant versus the initial model will cause error in the estimation process. The variance allowed in each of the model parameters can be defined based on the accuracy requirement of the estimation.
The design of the Kalman filter assumes the following state definitions:
x
1
=Z
s
−Z
u
x
2
={dot over (Z)}
s
x
3
=Z
u
−Z
r
x
4
={dot over (Z)}
u
The following state equations are derived from the free body diagram of FIG. 6 :
{dot over (x)} 1 =x 2 −x 4 x . 2 = 1 M s ( - K s x 1 + F d + 0.4 K s ) {dot over (x)} 3 =x 4 −{dot over (Z)} r x . 4 = 1 M u ( K s x 1 - K t x 3 - F d + ( 0.075 K t - 0.4 K s ) )
Assuming the input u=F d , the process disturbance v={dot over (Z)} r , and the acceleration offset 0.4 K s /M s and (0.075 K t -0.4 K s )/M u , the following state space representation is defined: x . = [ 0 1 0 - 1 - K s M s 0 0 0 0 0 0 1 K s M s 0 - K t M u 0 ] x + [ 0 1 M s 0 - 1 M u ] u + [ 0 0 - 1 0 ] v + [ 0 0.4 K s M u 0 ( 0.075 K t - 0.4 K s ) M u ] y=[ 1 0 0 0] x+w
{dot over (x)}=Ax+Bu+Gv+Λ
y=Cx+w
x 0 =[x s0 −x u0 0 x u0 0]
The process disturbance v(t) and the measurement noise w(t) are stationary, zero mean, Gaussian white processes with covariance kernels of
E{v ( t ) v T (τ)}= V δ( t −τ)
E{w ( t ) w T (τ)}= W δ( t −τ).
Note that V≧0 because it is a covariance matrix. Also assume that W>0. This assumption states that the noise affects all the measured outputs of the system, i.e., there are “no clean measurements.”
Assume that the initial state has mean and covariance given by
Mean:
E{x ( t 0 )}= {overscore (x)} 0
Covariance:
E{[x ( t 0 )− {overscore (x)} 0 ][x ( t 0 )− {overscore (x)} 0 ] T }=Σ 0
and that v, w, and x(t 0 ) are mutually uncorrelated.
Consider {circumflex over (x)}(t) an estimate of the state of the system at time t≧t 0 . Define the estimation error: e(t)=x(t)−{circumflex over (x)}(t) and the mean square estimation error: E{e(t)e(t) T }. Suppose that the input and (measured) output of the system for all prior times: u(t), y(t), t≧t 0 are known. The problem is then to use this information to construct an estimate {circumflex over (x)}(t) such that the mean square estimation error is minimized.
It turns out that the estimate {circumflex over (x)}(t) that minimizes the mean square error may be generated as the state of a dynamical system with the structure of an observer with a time-varying gain, L(t). The assumption is made that the estimation process is done for an arbitrarily long time, i.e., that t 0 →−∞. This assumption allows a constant estimator gain, L, to be designed by solving the dual Algebraic Riccatti equation:
{overscore (Σ)} A T +A{overscore (Σ)}+V−{overscore (Σ)}C T W −1 C{overscore (Σ)}
L={overscore (Σ)}C
T
W
−1
Assuming (A,C) is detectable, then the primary design step is to choose the appropriate V and W such that the estimator has the appropriate properties, e.g., accuracy, bandwidth, and noise rejection. There exist some tactics in the literature for approaching the selection of V and W. Using the design of L, the Kalman filter implementation becomes
{circumflex over ({dot over (x)})}=A{circumflex over (x)}+Bu+L ( y−C{circumflex over (x)} )+Λ
z=[0 0 1 0 ]x
where z is the state output of interest.
Using this filter design to model the suspension system, a filter output equal to instantaneous rolling radius deviation from nominal, ΔR, is obtained.
While the model shown employs sprung mass height or strut position as a measured input to derive ΔR, the model could alternatively be designed to employ other suspension system operating characteristics such as strut velocity, strut force, strut internal pressures, bushing deflections, hub acceleration, body acceleration, tire stress, tire deflection, road position, and suspension member strain. Derivation of such models is within the skill of one normally skilled in the art.
Further improvements to the slip control system are shown in FIG. 7 . As a result of having a more accurate longitudinal wheel speed, other ameliorative actions taken in system design to avoid false activations can be reduced. For example, activation thresholds were previously set to produce a slower response to slip due to the possibility of signal error. Since signal error is reduced with the present invention, the activation thresholds can be tightened up to improve performance. Thus, FIG. 7 shows a difference block 60 which compares the improved longitudinal wheel speed signal to a reference signal. The reference signal represents the expected longitudinal wheel speed based on a determination of the overall vehicle speed. The difference signal represents any slip that is occurring at the particular wheel. The difference signal is coupled to a threshold block 61 . When slip exceeds the thresholds, then an activation signal is sent to an activation and control algorithm block 62 . Other than a tightening or reduction of thresholds, threshold block 61 and algorithm block 62 perform in a conventional manner.
Known slip control systems also monitor individual wheel speed accelerations to detect slip. Due to the greater mass of the whole vehicle, vehicle acceleration is much more constrained than is wheel acceleration. Thus, a measured wheel acceleration outside the range of the overall vehicle is also an indication of wheel slip. Wheel and overall vehicle acceleration estimates are determined in an acceleration estimate block 63 and are coupled to a threshold block 64 . Since the acceleration calculations are more accurate using the present invention, the thresholds used in block 64 can be more aggressive that those of the prior art.
In yet another improvement, the present invention employs a suspension and vehicle model 65 with an additional output representative of the contact patch of the individual tire at any given moment. Contact patch is the footprint of the portion of the tire actually in contact with the road. This can be determined by model 65 in response to the instantaneous rolling radius, for example. The contact patch signal is coupled to activation and control algorithm 62 which modifies its operation (e.g., braking force) based on the likelihood of slip at various amounts of contact patch.
The suspension modeling of the present invention can be implemented within a control module for a slip control system, such as ABS, TC, or VSC, since these modules typically already contain the necessary hardware. However, when an active suspension control system is present which also performs modeling, it may be desirable to perform portions of the invention in a suspension module. Therefore, integration of a suspension control system with a braking control system is discussed below.
A first embodiment of an integrated vehicular control system is indicated generally at 100 in FIG. 8 . The control system 100 is particularly adapted to control fluid pressure in an electronically-controlled vehicular braking system and an electronically-controlled vehicular suspension system. The braking system can include anti-lock braking, traction control, and vehicle stability control functions. The suspension system can include active damping functions.
The control system 100 includes a first electronic control unit (ECU) 102 . The first ECU 102 includes a signal processor 104 and a braking algorithm 106 . Various sensors 108 strategically placed in a vehicle deliver input signals 110 to the signal processor 104 . Specifically, a lateral acceleration sensor 112 delivers an input signal 114 to the signal processor 104 . A longitudinal acceleration sensor 115 delivers an input signal 116 to the signal processor 104 . A steering wheel sensor 117 delivers an input signal 118 to the signal processor 104 . A yaw rate sensor 120 delivers an input signal 122 to the signal processor 104 . Depending upon the braking functions of the braking system, some of the above-listed sensors and their associated input signals may be deleted and others may be added. For example, a braking system that provides only ABS and TC functions may not require some of the above-listed sensors.
The signal processor 104 delivers transfer signals 124 to the braking algorithm 106 . The braking algorithm 106 delivers output signals 126 to a hydraulic control unit (HCU) 128 . The HCU 128 can include electromechanical components such as digital and/or proportional valves and pumps (not illustrated). The HCU 128 is hydraulically connected to wheel brakes and a source of brake fluid, neither of which is illustrated.
The control system 100 also includes a second ECU 130 . The second ECU 130 includes a signal processor 132 and a suspension algorithm 134 . Various sensors 135 strategically placed in a vehicle deliver input signals 136 to the signal processor 132 . Specifically, a suspension state sensor 137 delivers an input signal 138 to the signal processor 132 . A suspension displacement sensor 139 delivers an input signal 140 to the signal processor 132 . A relative velocity sensor 141 delivers an input signal 142 to the signal processor 132 . An unsprung mass acceleration sensor 143 delivers an input signal 144 to the signal processor 132 . Depending upon the performance requirements of the suspension system, some of the above-listed sensors may be deleted and others may be included.
The second signal processor 132 delivers transfer signals 145 to the suspension algorithm 134 . The first signal processor 104 delivers transfer signals 146 to the suspension algorithm 134 . The suspension algorithm 134 delivers output signals 148 to suspension actuators 150 , only one of which is illustrated. The actuators 150 are electrically controlled devices such as dampers that vary and control a damping rate of a vehicle. An actuator 150 can include electromechanical components such as digital and proportional valves.
Information from the vehicular braking system can be shared with the vehicular suspension system. For example, ECU 102 can direct information to ECU 130 . One example of transferred information from the braking system to the suspension system is the transfer signal 146 from signal processor 104 to suspension algorithm 134 . A second example of transferred information from the braking system to the suspension system is indicated by transfer signal 152 , wherein information from the braking algorithm 106 is directed to the suspension algorithm 134 .
Information from the suspension system can also be shared with the braking system. For example, ECU 130 can direct information to ECU 102 . One example of transferred information from the suspension system to the braking system is a transfer signal 154 to a load and load transfer detector 155 . Another example is a transfer signal 156 to a turning detector 157 . Yet another example is a transfer signal 158 for surface and mismatch tire detector 159 .
The control system 100 can be configured in various manners to share information from ECU 102 to ECU 130 , and vice versa. In one example, an ECU 102 for the braking system that receives inputs signals 114 , 116 , 118 and 122 , for lateral acceleration, longitudinal acceleration, steering wheel angle, and yaw rate, respectively, can transfer these input signals to ECU 130 for the suspension system. The signal processor 104 of ECU 102 can send transfer signal 146 to the suspension algorithm 134 .
In another example, if lateral acceleration and steering wheel angle signals 114 and 122 are not available to the braking system, a turning detector signal can be generated by ECU 130 and transmitted to ECU 102 to improve braking performance. If an electronically controlled suspension system is integrated with an electronically controlled ABS/TC braking system, turning of the vehicle can be detected by the suspension system, thereby generating a turning detector signal that is transmitted to a braking system that does not receive signals from lateral acceleration and steering wheel angle sensors. A turn detection signal to the braking system via ECU 102 can enhance braking performance, particularly during braking-in-turn and accelerating-in-turn.
A second embodiment of an integrated control system for controlling vehicular braking and suspension functions is indicated generally at 200 in FIG. 9 . Elements of control system 200 that are similar to elements of control system 100 are labeled with like reference numerals in the 200 series.
Control system 200 also includes an ABS/TC algorithm 206 A and a VSC algorithm 206 B in place of the braking algorithm 106 of control system 100 . Signal processors 204 and 232 may be placed separately from their respective algorithms 206 A, 206 B, and 230 , or they may be located in common ECU's (not illustrated in FIG. 9 ). Transfer signal 270 between ABS/TC algorithm 206 A and VSC algorithm 206 B is provided. Transfer signal 272 for load and load transfer is provided to the VSC algorithm 206 B. Transfer signal 273 from the signal processor 204 is provided to the VSC algorithm 206 B. Transfer signal 274 for the surface and mismatch tire detector is provided to the VSC algorithm 206 B. Transfer signal 275 is provided from the VSC algorithm 206 B to the suspension algorithm 234 . Output signal 276 is sent from the VSC algorithm 206 B to the HCU 228 .
Various calculations can be made for the suspension system. For example, relative velocity can be calculated from suspension displacement if it is not directly measured. A vehicle load and load transfer signal 154 , 254 can also be calculated or enhanced from a lateral acceleration signal 114 , a longitudinal acceleration signal 118 , and a steering wheel angle signal 122 when these are available.
A load and load transfer signal 154 , 254 is used by the braking algorithms to enhance braking torque proportioning and apply and dump pulse calculations.
A turning detector signal 156 , 256 (roll moment distribution) can be used to optimize vehicle handling before VSC activation and enhance brake torque distribution calculation during VSC activation.
A road surface roughness and tire mismatching signal 158 , 258 can be detected from suspension states and used by ABS/TC and VSC systems.
Braking/traction status information from the wheels can also be used to enhance braking algorithms by predicting pitch and roll motion in advance.
Suspension algorithms and braking algorithms can be embodied in separate ECU's 102 and 130 as illustrated in FIG. 8 . In other embodiments, the suspension and braking algorithms can be integrated into a single electronic control unit.
If steering wheel angle signal 122 , 222 and/or a lateral acceleration signal 114 , 214 are available, then split mu detection in ABS and TC algorithms (for stand alone ABS and TC systems) can be improved.
In other examples, ECU 102 can only receive information from ECU 130 . Thus, various input signals from the suspension system can be transferred to the braking system, but no signals are transferred from the braking system to the suspension system.
In yet other examples, ECU 130 can only receive information from ECU 102 . Thus, various input signals from the braking system can be transferred to the suspension system, but no signals are transferred from the suspension system to the braking system.
A third embodiment of an integrated control system for controlling vehicular braking and suspension functions is indicated generally at 300 in FIG. 10 . In control system 300 , a single ECU 302 receives inputs signals 304 from various sensors 306 strategically placed in a vehicle. A signal processor 308 may be incorporated in the ECU 302 that delivers transfer signals 310 to an algorithm 312 . The algorithm 312 delivers output signals 314 to a HCU 328 to provide a desired brake response. The algorithm 312 also delivers output signals 316 to actuators 350 to provide a desired suspension response. Control system 300 may be referred to as a totally integrated system for controlling vehicular braking and suspension. | The present invention determines a longitudinal wheel speed of an individual wheel from an angular rate signal from a wheel rotation sensor. Vehicle suspension information or operating characteristics are input to a suspension system mathematical model to determine instantaneous rolling radius, taking into account changes in tire rolling radius resulting from vertical motion of the road surface. Improved accuracy of wheel speed permits less severe filtering of wheel speeds in detecting wheel slip and/or modified speed and acceleration thresholds in slip control. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 61/109,936, filed on Oct. 31, 2008 and entitled “METHOD OF HANDLING AN RA PROCEDURE RELATED TO TIME ALIGNMENT TIMER IN WIRELESS COMMUNICATIONS SYSTEM AND RELATED COMMUNICATION DEVICE” the contents of which are incorporated herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method utilized in a wireless communication scheme and related communication device, and more particularly, to a method and related communication device utilized in a wireless communication system for improving a random access procedure associated with a time alignment timer.
2. Description of the Prior Art
A long-term evolution (LTE) system, initiated by the third generation partnership project (3GPP), is now being regarded as a new radio interface and radio network architecture that provides a high data rate, low latency, packet optimization, and improved system capacity and coverage. In the LTE system, an evolved universal terrestrial radio access network (E-UTRAN) includes a plurality of evolved Node-Bs (eNBs) and communicates with a plurality of mobile devices, also referred as user equipments (UEs).
Architecture of the radio interface protocol of the LTE system includes three layers: the Physical Layer (L1), the Data Link Layer (L2), and the Network Layer (L3), wherein a control plane of L3 is a Radio Resource Control (RRC) layer, and L2 is further divided into a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer and a Medium Access Control (MAC) layer.
In the LTE system, if a mobile device such as a mobile phone desires to connect to the Internet or communicate with other mobile phones via the LTE system, the mobile device firstly needs to be synchronized with a base station that serves the mobile device on uplink (UL) timing. The purpose of being synchronized with the base station is to prevent signals transmitted from the mobile device from colliding with other signals sent from other mobile devices under the coverage of the base station. In general, a time alignment timer of the mobile device is utilized for indicating whether the mobile device is synchronized with the base station on uplink timing. When the time alignment timer is running, uplink timing synchronization is still established. If the time alignment timer expires, then this indicates that the mobile device is not synchronized with the base station on uplink timing.
FIG. 1 is a diagram showing a Random Access (RA) procedure of the LTE system according to the prior art. As can be seen from FIG. 1 , when a user equipment (UE) 210 initials an RA procedure, an RA preamble is transmitted from the UE 210 to the Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) 220 . The E-UTRAN 220 needs to transmit an RA response (RAR) corresponding to the RA preamble to the UE 210 . After that, the UE 210 transmits a media access control protocol data unit (MAC PDU) for contention resolution to the E-UTRAN 220 , wherein the MAC PDU usually consists of a MAC header and zero, one or more MAC Control Elements (CE). A MAC RAR usually consists of three fields: TA (Timing Advance)/UL Grant/Temporary C-RNTI.
However, it is not clear how to handle an ongoing RA procedure when a Time Alignment Timer expires. More specifically, when a Time Alignment Timer expires during an ongoing RA procedure, how to handle the unfinished ongoing RA procedure is not specified in the 3GPP specification. In addition, the 3GPP specification defines that when a Time Alignment Timer expires in a UE, the UE flushes all HARQ buffers. This makes a failure of a retransmission for a MAC PDU transmission for contention resolution when there is a HARQ NACK from the eNB, and the failure of the MAC PDU retransmission can even hang the UE, as shown in FIG. 2 . In FIG. 2 , a UE under RRC-CONNECTED mode with UL sync but without a UL grant is trying to initiate a UL data transmission by sending a RA preamble first to an eNB.
When a downlink (DL) data arrival occurs, the eNB can use a PDCCH (physical downlink control channel) order to request the UE to perform a RA procedure if the eNB considers that the UE no longer has uplink synchronization. Please refer to FIG. 3 , where a PDCCH order for downlink data arrival is received by a UE under RRC_CONNECTED mode and an uplink transmission is initiated by the UE whose uplink timing is still synchronized. When the uplink timing of the UE is still synchronized, a time alignment timer is in a running state. Since the time alignment timer is running, PUCCH (physical uplink control channel) resource is considered available. In one case, the UE sends a scheduling request (SR) on PUCCH, but the eNB discards the SR and does not send a RAR to the UE since the uplink synchronization of the UE is considered lost. As a result, sending a SR is useless and it is wasteful of UE power in such case. After this, the UE may transmit a SRS (Sounding Reference Symbol) or a CQI (Channel Quality Indicator) according to RRC configuration. In another case, the UE fails to receive the RAR sent from the eNB and consequently triggers a SRS or a CQI to the eNB. However, without the timing advance information from the RAR, the eNB may fail to receive the SRS and CQI in both cases since the timing advance is not updated to an accurate value.
A NDI (New Data Indicator) is used for indicating whether the corresponding transmission is a new transmission or a retransmission. Each NDI is compared with the previous NDI. Please refer to FIG. 4 , whereas UE under RRC_CONNECTED mode with a running time alignment timer handles a UL transmission after receiving a PDCCH order for DL data arrival. Since the time alignment timer keeps running through the steps of FIG. 4 , the UE does not flush HARQ buffers and does not consider the next transmission for each process as the very first transmission. The very first transmission is a transmission with no available previous NDI. However, the NDI on PDCCH is randomly selected by the eNB. This impacts the following uplink transmission because the UE may find that the NDI on PDCCH is identical to the previous NDI and thereby performs a retransmission of data in one HARQ buffer. Any transmission after such retransmission should be a new transmission instead of a retransmission.
SUMMARY OF THE INVENTION
Therefore, the present invention provides a method for improving a random access procedure corresponding to a time alignment timer in a wireless communication system and related communication device that can avoid transmission errors.
According to an embodiment of the present invention, a method for improving a random access procedure for a mobile device of a wireless communication system is disclosed. The method includes controlling the random access procedure according to expiry of a time alignment timer used for determining a synchronization state between the mobile device and the base station.
According to an embodiment of the present invention, a communication device of a wireless communication system for improving a random access procedure is further disclosed and includes a computer readable recording medium, a processor, a communication interfacing unit and a control unit. The computer readable recording medium is used for storing program code corresponding to a process. The processor is coupled to the computer readable recording medium, and used for processing the program code to execute the process. The communication interfacing unit is used for exchanging signals with a peer communication device of the wireless communication system. The control unit is coupled to the processor and communication interfacing unit, and used for controlling the communication interfacing unit and the communication device according to processing results of the processor. The process includes controlling the random access procedure according to expiry of a time alignment timer used for determining a synchronization state between the mobile device and the base station and the time alignment message is utilized by the base station to update a timing advance for the communication device.
According to an embodiment of the present invention, a method for improving a random access procedure for a mobile device of a wireless communication system is further disclosed. The method includes mobile device configuring a time alignment timer of the mobile device to an expiry state when downlink signaling for triggering the random access procedure is received and the time alignment timer is in a running state, and according to expiry of the time alignment timer, performing a resetting process corresponding to a HARQ function and uplink resources of the mobile device.
According to an embodiment of the present invention, a communication device of a wireless communication system for improving a random access procedure is further disclosed and includes a computer readable recording medium, a processor, a communication interfacing unit and a control unit. The computer readable recording medium is used for storing program code corresponding to a process. The processor is coupled to the computer readable recording medium, and used for processing the program code to execute the process. The communication interfacing unit is used for exchanging signals with a peer communication device of the wireless communication system. The control unit is coupled to the processor and communication interfacing unit, and used for controlling the communication interfacing unit and the communication device according to processing results of the processor. The process includes configuring a time alignment timer of the communication device to an expiry state when downlink signaling for triggering the random access procedure is received and the time alignment timer is in a running state, and according to expiry of the time alignment timer, performing a resetting process corresponding to a HARQ function and uplink resources of the communication device.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram illustrating a RA procedure of the LTE system according to the prior art.
FIG. 2 is a flowchart illustrating a problem of a RA procedure when a time alignment timer expires according to the prior art.
FIG. 3 is a flowchart illustrating a problem of a UE handling a UL transmission after receiving a PDCCH order for DL data arrival while a time alignment timer is in a running state according to the prior art.
FIG. 4 is a flowchart illustrating another problem of a UE handling a UL transmission after receiving a PDCCH order for DL data arrival while a time alignment timer is in a running state according to the prior art.
FIG. 5 is a schematic diagram of a wireless communication system.
FIG. 6 is a schematic diagram of a communication device according to an embodiment of the present invention.
FIG. 7 is a schematic diagram of the multiple communications protocol layers of the LTE system applied by the program code of an embodiment of the present invention.
FIG. 8 is a flowchart of a process according to an embodiment of the present invention.
FIG. 9 is a flowchart of a process for the LTE system according to an embodiment of the present invention.
FIG. 10 is a flowchart of a process according to an embodiment of the present invention.
FIG. 11 is a flowchart of a process for the LTE system according to an embodiment of the present invention.
FIG. 12 is a flowchart of a process according to an embodiment of the present invention.
FIG. 13 is a flowchart of a process for the LTE system according to an embodiment of the present invention.
FIG. 14 is a flowchart of a process for the LTE system according to an embodiment of the present invention.
DETAILED DESCRIPTION
Please refer to FIG. 5 , which illustrates a schematic diagram of a wireless communication system 50 according to an embodiment of the present invention. Briefly, the wireless communication system 50 is composed of a network and a plurality of mobile devices. In FIG. 5 , the network and the mobile devices are simply utilized for illustrating the structure of the wireless communication system 50 . Preferably, the wireless communication system 50 is an LTE (long-term evolution) system. In the LTE system, the network is referred as an EUTRAN (evolved-UTRAN) comprising a plurality of eNBs, whereas the mobile devices are referred as user equipments (UEs). The UEs can be devices such as mobile phones, computer systems, etc. Besides, the network and the UE can be seen as a transmitter or receiver according to transmission direction, e.g., for uplink (UL), the UE is the transmitter and the network is the receiver, and for downlink (DL), the network is the transmitter and the UE is the receiver.
Please refer to FIG. 6 , which illustrates a schematic diagram of a communication device 60 according to an embodiment of the present invention. The communication device 60 can be the mobile devices shown in FIG. 5 and includes a processor 600 , a computer readable recording medium 610 , a communication interfacing unit 620 and a control unit 630 . The computer readable recording medium 610 is any data storage device that includes HARQ (Hybrid Automatic Repeat Request) buffers BF( 1 )-BF(n), a data buffer 650 , and program code 614 , thereafter read and processed by the processor 600 . Examples of the computer readable recording medium 610 include a subscriber identity module (SIM), read-only memory (ROM), random-access memory (RAM), CD-ROMs, magnetic tapes, hard disks, optical data storage devices, and carrier waves (such as data transmission through the Internet). The control unit 630 controls the communication interfacing unit 620 and related operations and states of the communication device 60 according to processing results of the processor 600 . The communication interfacing unit 620 is preferably a radio transceiver and accordingly exchanges wireless signals with the eNB.
Please refer to FIG. 7 , which illustrates a schematic diagram of the multiple communications protocol layers of the LTE system applied by the program code 614 according to an embodiment of the present invention. The program code 614 includes program code of multiple communications protocol layers, which from top to bottom are a radio resource control (RRC) layer 700 , a packet data convergence protocol (PDCP) layer 710 , a radio link control (RLC) layer 720 , a medium access control (MAC) layer 730 and a physical (PHY) layer 740 .
The MAC layer 730 functions for performing a random access (RA) procedure and HARQ processes HAP( 1 )-HAP(n) for transmission of MAC packets, i.e. MAC protocol data units (MAC PDUs). The HARQ buffers BF( 1 )-BF(n) are used for packet data storage of the HARQ processes HAP( 1 )-HAP(n), respectively. A transmission of MAC PDUs, other than a very first transmission, is determined to be a new transmission or a retransmission according to a comparison between a received new data indicator (NDI) and a previous NDI stored in corresponding HARQ buffer. The very first transmission is a transmission with no available previous NDI. In addition, the MAC layer 730 uses a time alignment timer for determining a synchronization state between the communication device 60 and the eNB on uplink timing. That is, the time alignment timer in a running state indicates that the communication device 60 is synchronized with the eNB, whereas the time alignment timer in an expiry or stop state indicates that the communication device 60 is not synchronized with the eNB. The RA procedure includes transmission of an RA preamble, reception of an RAR (random access response), and transmission of a MAC PDU for contention resolution in order. The MAC PDU for contention resolution is generated and stored in a data buffer 650 also known as a [Message3] buffer in the art. Assume that the HARQ process HAP( 1 ) is used for transmission of the MAC PDU for contention resolution in one embodiment.
The PHY layer 740 includes a physical downlink control channel (PDCCH) for reception of downlink signaling and a physical uplink control channel (PUCCH) for transmission of uplink signaling. A SR (scheduling Request) for requesting the eNB for an uplink grant can be sent on the PUCCH. The eNB can send a PDCCH order to request the UE to perform the RA procedure.
A regular buffer status report (BSR) can be triggered in the MAC layer 730 for reporting volume of uplink packets in the PDCP layer 710 or the RLC layer 720 available to be sent to the eNB. In addition, the regular BSR can trigger a SR when the UE has no uplink resources in certain transmission opportunity. When a SR sent on PUCCH is configured, the SR is sent on PUCCH. When the SR sent on PUCCH is not configured, the MAC layer 730 needs to initiate a RA procedure for the SR.
The time alignment timer of the mobile device is used for determining whether the communication device 60 is synchronized with the eNB on uplink timing. If the time alignment timer is in a running state, the communication device 60 is determined to be synchronized with the eNB on uplink timing. If the time alignment timer is in an expiry or stop state, the communication device 60 is determined to be asynchronous with the eNB on uplink timing. In addition, a time alignment message is utilized by the eNB to update a timing advance for the communication device 60 . The timing advance is well known in the art and thus description about usage of the timing advance is omitted herein. In this situation, the following processes are provided for the communication device 60 to control an on-going RA procedure according to expiry of the time alignment timer.
Please refer to FIG. 8 , which illustrates a flowchart of a process 800 according to an embodiment of the present invention. The process 800 is utilized for improving a random access procedure for a UE of a wireless communication system. The process 800 can be compiled into the program code 614 and includes the following steps:
Step 800 : Start.
Step 810 : Initiate a RA procedure.
Step 820 : Start or restart a time alignment timer of the UE when a time alignment message is received.
Step 830 : Abort the RA procedure after the time alignment timer expires.
Step 840 : End.
According to the process 800 , the UE initiates the RA procedure and starts or restarts a time alignment timer when the time alignment message is received from the eNB. When the time alignment timer expires, this means that the UE is no longer synchronized with the eNB. However the RA procedure is still on-going and the UE may transmit packets to the eNB. Therefore, according to one embodiment of the present invention, the UE aborts the on-going RA procedure after the time alignment timer expires to avoid transmission error due to asynchronous uplink timing.
Preferably, the UE does not abort the RA procedure until a packet for contention resolution in the RA procedure is transmitted after the time alignment timer expires. The packet for contention resolution is a MAC protocol data unit (PDU) stored in the [Message3] buffer. In addition, the UE can re-initiate the RA procedure after the RA procedure is aborted.
Please refer to FIG. 9 , which is a flowchart of a process 900 for the LTE system according to an embodiment of the present invention. The process 900 applies the concept of the process 800 . The UE, initially in a RRC_CONNECTED mode, under uplink synchronization with an eNB, has no UL grant. Since no UL grant is allocated for the UE, the UE needs to perform a RA procedure for a SR when UL data transmission is initiated. Meanwhile, a time alignment timer of the UE is assumed to have been in a running state. The UE performs steps A 1 -A 3 during the RA procedure, and a MAC PDU for contention resolution is transmitted in step A 3 . Functions of the steps A 1 -A 2 are well known in the art. In the step A 4 , the UE aborts the RA procedure after the time alignment timer expires. In step A 5 , the eNB feedbacks a negative acknowledgement (NACK) associated with the MAC PDU for contention resolution (i.e. Message 3 ). Since the RA procedure is aborted, the NACK is consequently discarded in step A 6 according to the embodiment of the present invention. Therefore, the transmission error of the UE is avoided.
Please refer to FIG. 14 , which is a flowchart of a process 910 for the LTE system according to an embodiment of the present invention. The process 910 applies the concept of the process 800 . The UE, initially in an RRC_CONNECTED mode, under uplink synchronization with an eNB, has no UL grant. Since no UL grant is allocated for the UE, the UE needs to perform a RA procedure for a SR when UL data transmission is initiated. Meanwhile, a time alignment timer of the UE is assumed to have been in a running state. The UE performs steps D 1 -D 3 during the RA procedure, and a MAC PDU for contention resolution is transmitted in step D 3 . the steps D 1 -D 3 are the same as the steps A 1 -A 3 of the process 900 . In the step A 4 , the UE aborts the RA procedure after the time alignment timer expires and stops receiving any HARQ feedbacks, e.g. an HARQ NACK. In step A 5 , the eNB feedbacks an HARQ NACK associated with the MAC PDU for contention resolution (i.e. Message 3 ). Since the RA procedure is aborted and the HARQ feedback is stopped in step A 4 , the transmission error of the UE is avoided.
Please refer to FIG. 10 , which illustrates a flowchart of a process 1005 according to an embodiment of the present invention. The process 1005 is utilized for improving a random access procedure for a UE of a wireless communication system. The process 1005 can be compiled into the program code 614 and includes the following steps:
Step 1000 : Start.
Step 1010 : Initiate a RA procedure.
Step 1020 : Start a time alignment timer of the UE when a time alignment message is received.
Step 1030 : Continue the RA procedure when the time alignment timer expires.
Step 1040 : Flush all HARQ buffers of the UE except the HARQ buffer used for transmission of a packet for contention resolution.
Step 1050 : Regard a transmission of each of HARQ processes as a very first transmission for corresponding HARQ process.
Step 1060 : End.
According to the process 1005 , the UE initiates the RA procedure and starts a time alignment timer when the time alignment message is received from the eNB. When the time alignment timer expires, this means that the UE is no longer synchronized with the eNB, and the UE continues the RA procedure. That is, the RA procedure is not interrupted by the UE. Then, the UE flushes all HARQ buffers except the HARQ buffer for transmission of a packet for contention resolution. After flushing the HARQ buffer, the UE regards the first transmission of each HARQ process as a very first transmission for corresponding HARQ process. For example, the UE flushes the HARQ buffers BF( 2 )-BF(n) except the HARQ buffers BF( 1 ). After flushing the HARQ buffers BF( 2 )-BF(n), the UE regards the first transmission of HARQ processes HAP( 2 )-HAP(n) as the very first transmission. Through the process 1005 , since no previous NDI is needed in the very first transmission, the retransmission failure corresponding to the RA procedure is avoided.
Preferably, when a random access response (RAR) of the RA procedure is received, the UE further applies a time alignment command contained in the RAR to re-start the time alignment timer. When the UE discovers that the contention resolution is unsuccessful, the UE stops the time alignment timer.
Please refer to FIG. 11 , which is a flowchart of a process 1100 for the LTE system according to an embodiment of the present invention. The process 1100 applies the concept of the process 1005 . The initial state of the UE and steps B 1 -B 3 in FIG. 11 are the same as the initial state of the UE and steps A 1 -A 3 in FIG. 9 . In step B 4 , when the time alignment timer expires, the UE continues the RA procedure and flushes all HARQ buffers except the HARQ buffer for contention resolution. In step B 5 , the eNB feedbacks a NACK associated with the MAC PDU for contention resolution. In this situation, the UE is able to retransmit the MACK PDU for contention resolution since the corresponding HARQ buffer is not flushed. Thus the retransmission failure due to empty HARQ buffer is avoided.
Instead of Steps 1040 and 1050 , the UE can acquire the packet for contension resolution from a data buffer used for contension resolution (e.g. the [Message3] buffer) for retransmission when the HARQ buffer responsible for transmission of the packet for contension resolution, e.g. the BF( 1 ), is empty and a HARQ NACK associated with the packet for contension resolution or downlink signaling used for adaptive retransmission is received. The downlink signaling used for adaptive retransmission is preferable adaptive retransmission signaling sent on the PDCCH. Through the abovementioned actions, the UE is able to retransmit the packet for contension resolution by retrieving the packet from the corresponding data buffer.
Please refer to FIG. 12 , which illustrates a flowchart of a process 1200 according to an embodiment of the present invention. The process 1200 is utilized for improving a random access procedure for a UE of a wireless communication system. The process 1200 can be compiled into the program code 614 and includes the following steps:
Step 1205 : Start.
Step 1210 : Configure a time alignment timer of the UE to an expiry state when downlink signaling for triggering a RA procedure is received and the time alignment timer is in a running state.
Step 1220 : Perform a resetting process corresponding to a HARQ function and uplink resources according to the expiry of the time alignment timer.
Step 1230 : End.
According to the process 1200 , the UE configures the time alignment timer to an expiry state when the downlink signaling for triggering a RA procedure is received and time alignment timer is in a running state. According to the expiry of the time alignment timer, the UE performs the resetting process corresponding to the HARQ function and the uplink resources, so as to avoid the following transmissions being mistakenly performed. For example, a mistaken transmission scenario, where a next transmission shall be a new transmission but the UE mistakenly performs the transmission as a retransmission, can be avoided.
Furthermore, the UE can initiate the RA procedure after the resetting process is performed. Alternatively, the UE can initiate the RA procedure when the downlink signaling is received and the time alignment timer is in the running state. In this situation, the UE further applies a time alignment command contained in a RAR of the RA procedure, and re-starts the time alignment timer according to the time alignment command.
Preferably, the downlink signaling for triggering the random access procedure is a PDCCH order and is generated due to downlink data arrival.
In the resetting process corresponding to the HARQ function, the UE flushes all the HARQ buffers when the RA procedure has not been performed, or flushes all the HARQ buffers except the HARQ buffer for transmission of a packet for contention resolution when the RA procedure is on-going. In addition, the first transmission of each HARQ process, which follows HARQ buffer flush, is regarded as a very first transmission for corresponding HARQ process. The NDIs (New Data Indicators) for the UE to determine the current transmission type of HARQ processes are reset.
In the resetting process corresponding to the uplink resources, the UE releases resources corresponding to uplink signaling and sounding reference symbols.
Please refer to FIG. 13 , which is a flowchart of a process 1300 for the LTE system according to an embodiment of the present invention. The process 1300 applies the concept of the process 1200 . Initially, the UE stays in an RRC_CONNECTED mode, and the time alignment timer is in the running state. In step C 1 , the UE receives downlink signaling indicating DL data arrival from the PDCCH, where the downlink signaling indicating DL data arrival is used for triggering the UE to initiate a RA procedure. In step C 2 , the time alignment timer expires and accordingly the UE performs the abovementioned resetting process. In this situation, the UE does not mistakenly determine an expected retransmission to be a new transmission or an expected retransmission to be a new transmission, since the NDIs are all reset. As a result, transmission errors possibly occurred in the RA procedure performed in steps C 3 and C 4 are avoided.
In conclusion, the above embodiments are provided for handling an ongoing RA procedure when a time alignment timer expires, and a RA procedure triggered by a PDCCH order with a running time alignment timer to avoid transmission errors in the RA procedure.
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims. | A method for improving a random access procedure for a mobile device of a wireless communication system is disclosed. The method includes initiating the random access procedure, starting a time alignment timer of the mobile device when receiving a time alignment message transmitted by a base station of the wireless communication system, and controlling the random access procedure according to expiry of the time alignment timer, wherein the time alignment timer of the mobile device is used for determining a synchronization state between the mobile device and the base station and the time alignment message is utilized by the base station to update a timing advance for the mobile device. | 7 |
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to a high security cylinder lock having an alarm circuitry for indicating attempts of lock snapping. The proposed cylinder lock is able to generate at least an audible alarm signal in result of a lock snapping attempt and also is able to withstand the lock snapping attempt.
BACKGROUND OF THE INVENTION
[0002] Lock snapping is a frequently used technique for breaking in a locked place. Typically a burglar obtains a device for snapping the outer end of a double cylinder lock and then applies a torque, usually in the vertical direction if not in combination to both vertical and horizontal directions. The weakest point in a double cylinder lock is the hole usually in the middle of the two cylinder halves, said hole drilled right below the plug for securing the cylinder lock to the door. Once the burglar applies torque to the snap device, the cylinder lock breaks apart and the two broken cylinder halves separate from each other. The cylinder half on the outer side of the door remains on the snap device whereas the cylinder part on the inner side is pushed by the burglar to fall towards the inside of the door. The burglar then inserts a new cylinder lock into the hole and easily opens the lock with his own key. An alternative is to force the deadbolts be received in the body of the lock through use of an L-shaped tool.
[0003] EP 2 208 839 relates to a high security lock cylinder with a pre-determined breaking line intended for breaking during a lock snapping attempt. Said line is mechanically weakened to be ruptured in response to a breaking force applied by a snapping tool. When the cylinder lock is broken as a result of an attack, the bridge between the two cylinder halves remains intact and malicious removal of the lock cylinder is prevented. The remaining part of the attacked cylinder is still able to receive the key thus allowing the original key holder still able to lock and unlock the cylinder lock.
[0004] DE 10 325 731 relates to an alarm trigger for lock cylinders against unauthorized break-in attempts. The cylinder lock has non-conductive means between two electrically conductive means in a casing which only produces trigger contact when broken or deformed. When the lock cylinder is broken at the bridging part in between the two cylinder halves or it is removed from its dedicated location, the conductive means of the assembly instantly get in contact and thus an alarm signal is triggered.
[0005] Said assembly does still not prevent the unauthorized person from entering the building, nor does it allow the subsequent use of the original key of the authorized person in order to unlock and lock the door even after the lock snapping attack. Hence, it is a must that the cylinder lock shall be replaced by a new cylinder lock after each and every lock snapping attack. A further disadvantage is the fact that the unauthorized person may enter the building after lock snapping attack and then destroy, deactivate or de-energize the alarm arrangement. Additionally, this device requires an uninterrupted power supply and montage of conductive cables and specifically trained montage personnel. More important than all, the functionality of this assembly seriously relies on a metal part which is subject to metal fatigue in time.
[0006] DE 3 913 204 relates to a cylinder lock core protection device which has an outer drilling protection shield for detection of an unauthorized attempt. The unauthorized person may still enter the building after a lock snapping attack, and may then deactivate or destroy the alarm arrangement.
[0007] DE 83 08 613 relates to a lock with electrical tapping-alarm signaling device, its housing and a bolt member. The assembly comprises a cover for the alarm triggering mechanism, which is naturally bigger than the lock cylinder itself. Thus said assembly requires an off-size montage space in the door body.
[0008] WO 2009/093 090 relates to a signaling device for burglary prevention system with electrical body lock sensors placed on the cylinder lock insert joining an alarm system through wires. This assembly requires an uninterrupted power supply and montage of conductive cables and is not suitable for use in existing doors.
[0009] DE 4 104 042 relates to a core protector for a cylinder lock, incorporating a blade directed towards cylinder core for cutting a conducting foil in order to trigger an alarm mechanism. Attempted entry drilling forces push the rosette backwards along bars and the blade cuts the foil, thereby triggering an alarm.
OBJECTS OF THE INVENTION
[0010] An object of the present invention is to provide a cylinder lock which comprises an alarm circuitry located inside the cylinder body for facilitating installation to existing doors.
[0011] Another object of the present invention is to provide an alarm incorporated cylinder lock which triggers during a lock snapping attempt.
[0012] Another object of the present invention is to provide an alarm incorporated cylinder-lock which is operational even after a successful lock snapping attempt.
SUMMARY OF THE INVENTION
[0013] A cylinder lock having a first cylinder half, which in use, is mounted on the indoor side and a second cylinder half, which in use, is mounted on the outdoor side of a door, is disclosed. The cylinder lock further comprises a notch cut out on the outdoor end of the second cylinder half for forming a breakable tip portion on said second cylinder half. A rod extends along the second cylinder half and enters, partly at its first end, in the first cylinder half. The rod is secured, at its second end, to the tip portion of the second cylinder half. The cylinder lock further comprises a volume formed on said first cylinder half for accommodating an alarm circuitry including at least an electronic circuit board, a magnetic switch and a magnet. The first end of the rod is interposed between the magnetic switch and the magnet of the alarm circuitry such that when the tip portion of the second cylinder half breaks apart, the rod slides out of the first cylinder half for detection of a break-in attempt.
[0014] The cylinder lock according to the invention may further comprise, within the second cylinder half, a spring loaded block pin for blocking the gap of said rod once the rod slides out of said second cylinder half such that re-insertion of said rod is eliminated. If the gap of the rod remains vacant, it may be possible that the alarm may be de-activated by inserting a thin metal object, or back inserting the rod itself, into the gap and filling the volume in between the magnet and the magnetic switch.
BRIEF DESCRIPTION OF THE FIGURES
[0015] Accompanying drawings are given solely for the purpose of exemplifying a cylinder-lock whose advantages over prior art will be explained in detail hereinafter:
[0016] FIG. 1 demonstrates a side view (a) and cross-section A-A (b) of an embodiment of the cylinder lock according to the present invention.
[0017] FIG. 2 demonstrates a rear perspective view (a) and front view (b) of the first embodiment of the cylinder lock according to the present invention.
[0018] FIG. 3 demonstrates a bottom view (a), a side view (b) and cross-section A-A (c) of the first embodiment of the cylinder lock according to the present invention.
[0019] FIG. 4 demonstrates a rear perspective view (a) and front view (b) of a second embodiment of the cylinder lock according to the present invention.
[0020] FIG. 5 demonstrates a bottom view (a), a side view (b) and cross-section A-A (c) of the second embodiment of the cylinder lock according to the present invention.
[0021] FIG. 6 demonstrates a rear perspective view of a variation of the second embodiment of the cylinder lock according to the present invention.
[0022] FIG. 7 demonstrates a bottom view (a), a side view (b) and cross-section A-A (c) of the variation of the second embodiment of the cylinder lock according to the present invention.
[0023] FIG. 8 demonstrates a rear perspective view (a) and a front view (b) of a third embodiment of the cylinder lock according to the present invention.
[0024] FIG. 9 demonstrates a bottom view (a), a side view (b) and cross-section A-A (c) of the third embodiment of the cylinder lock according to the present invention.
[0025] FIGS. 10 a and 10 b demonstrates respectively, the bottom and side views of a cylinder lock according to the present invention.
[0026] FIG. 10 c demonstrates the A-A cross section view of the cylinder lock of FIG. 10 a.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The present invention overcomes the above-mentioned shortcomings of the prior art by way of incorporating an alarm circuitry inside the body of a cylinder lock where said cylinder lock has a pre-determined breaking line for installation on the outer part of a door. The present invention therefore provides an alarm triggering cylinder lock which remains operational even after a successful lock snapping attack. The core idea underlying the present invention is to provide a cylinder lock;
which will withstand a lock snapping attack, which will scare the unauthorized person during and after said attack and thereby force him to cease the attack, and which will remain intact and operational even if the attack turns out to be successful and part of the cylinder is broken apart.
[0031] The cylinder lock according to the present invention therefore eliminates the need for an additional locksmith work after a lock snapping attack. A new cylinder lock may be installed easily by way of unscrewing the securing bolt, replacing a new cylinder lock and then screwing the securing bolt back in place.
[0032] The present invention additionally provides an alarm signaling device which can be installed inside the body of a cylinder lock, thus preventing necessities of extra space to be opened or drilled in the door body and of additional alarm indication means, such as an audio source, a buzzer etc.. The present invention may further provide a cylinder lock which is suitable for communicating with other alarm systems which may suitably be found in place. Even though the well-known motion detectors or magnetic contact sensors of existing alarm systems may not alert during a lock snapping attack, the cylinder lock of the present invention allows, in real time, dissemination of attack information with the surrounding alarm systems.
[0033] The following reference numerals have used in the appended drawings;
( 1 ) cylinder lock body ( 2 ) rod ( 3 ) magnetic switch ( 4 ) battery ( 5 ) electronic circuit board ( 6 ) buzzer ( 7 ) anchor pin ( 8 ) tip portion ( 9 ) cover ( 10 ) notch ( 11 ) sonic outlet channel ( 12 ) echo surface ( 13 ) magnet ( 14 ) connector ( 15 ) cable ( 16 ) external connection apparatus ( 17 ) external buzzer box ( 18 ) bridge ( 21 ) first cylinder half ( 22 ) second cylinder half ( 23 ) block pin
[0055] In a first embodiment shown in FIGS. 1 , 2 and 3 ; the cylinder lock body ( 1 ) comprises an alarm circuitry located in the first cylinder half half. The cylinder lock body ( 1 ) comprises two plugs connected by a cam. The cylinder lock body ( 1 ) has a first cylinder half ( 21 ) for mounting on the indoor part of a door and a second cylinder half ( 22 ) for mounting on the outdoor part of a door. In all drawings attached to this specification, the first cylinder half intended for indoor part has alarm circuitry and no tumbler pins whereas the second cylinder half intended for outdoor side has a plurality of tumbler pins. The cylinder ( 1 ) in the appended drawings is a Euro profile whereas the invention may be applied to other types of cylinders as well.
[0056] The second cylinder half ( 22 ) according to the present invention has a notch ( 10 ) in the form of a partial cut out which is intended to break during a snapping attempt. The purpose for cutting a notch ( 10 ) is to prevent breaking of the bridge ( 18 ) and to prevent breaking apart of the first and second cylinder halves. Once the cylinder is snapped from the second part, the snapping tool would snap the tip portion ( 8 ) of the second cylinder half ( 22 ) and break it apart without jeopardizing the bridging portion in between the first and second cylinder halves.
[0057] A rod ( 2 ) made of a metallic material is fixed by an anchor pin ( 7 ) in the tip portion ( 8 ) of the second cylinder half ( 22 ) in order to obtain a firm attachment between the rod ( 2 ) and tip portion ( 8 ). The metallic rod ( 2 ) extends along the body of the second cylinder half ( 22 ) and enters partly in the first cylinder half ( 21 ) where the alarm circuitry is located. It is important however that the metallic rod is secured to the tip portion ( 8 ) of the second cylinder half ( 22 ) since it has to slide out of the cylinder body if or when the tip portion breaks apart in result of a snapping attempt. Part of the rod ( 2 ) which extends inside the first cylinder half ( 21 ) remains in between a magnetic switch ( 3 ) and a magnet ( 13 ) located in said first part. Under normal operating conditions, part of said rod ( 2 ) is always interposed between the magnet ( 13 ) and the magnetic switch ( 3 ) such that the magnetic switch ( 3 ) cannot sense the magnet ( 13 ) located opposite said magnetic switch ( 3 ). The existence of the rod ( 2 ) between the magnet ( 13 ) and the magnetic switch ( 3 ) ensures that the alarm is not triggered.
[0058] The first cylinder half ( 21 ) has a volume for containing various components of the alarm circuitry. These include at least an electronic circuit board ( 5 ), a buzzer ( 6 ), a battery ( 4 ), a magnetic switch ( 3 ) and a magnet ( 13 ). This volume is depicted like a rectangular prism in the appended drawings. Conveniently, the volume is closed by a cover ( 9 ) in order to protect the electronic circuitry contained therein.
[0059] The magnetic switch ( 3 ) may be a reed switch located suitably for sensing the motion of the metallic rod ( 2 ) during a lock snapping attack. As the metallic rod ( 2 ) is secured to the tip portion ( 8 ) of the second cylinder half ( 22 ), the rod slides initially out of the first cylinder half ( 21 ) when the tip portion ( 8 ) breaks apart. As the position of the rod ( 2 ) between the switch ( 3 ) and magnet ( 13 ) changes and eventually the rod completely slides out of the interspace, this is sensed by the switch and an alarm is triggered. An audible signal is then released by a buzzer ( 6 ).
[0060] In order to increase the intensity of the sound generated by the buzzer ( 6 ), an echo surface ( 12 ) is formed on the cover ( 9 ). The echo surface is concave arc form such that the sound generated by the buzzer ( 6 ) is directed towards to the second cylinder half ( 22 ) whose tip portion ( 8 ) is detached. Additionally, a sonic outlet channel ( 11 ) is formed on the second cylinder half ( 22 ) for conveying the sound waves from the buzzer to the outlet of the second cylinder half. The person making the lock snapping attack hears the sound more intensely since the sound waves are localized in the sonic outlet channel ( 11 ).
[0061] A second embodiment shown in FIGS. 4 and 5 varies from the first embodiment by the fact that the first cylinder half ( 21 ) is equipped with a connector ( 14 ) for transmitting data from the electronic circuit board ( 5 ) to the periphery, such as an alarm system found in the building or the flat. In this case, the cylinder need not to have a buzzer ( 6 ) and/or a battery ( 4 ), as these two components may conveniently be placed outside the cylinder, e.g. on the inner surface of the door. The connector ( 14 ) may be used to transmit not only data but also energy.
[0062] A third embodiment further comprises an external connection apparatus ( 16 ) for mounting to the inner face of the door. As is shown in FIGS. 6 and 7 the external connection apparatus ( 16 ) connects through a cable ( 15 ) to the connector ( 14 ). Data from the electronic circuit board ( 5 ) can be transferred to the external elements via cables or wireless means; so that the alarm incorporated cylinder lock can be used in communication with various other peripheral devices such as loudspeakers, fire alarms and closed circuit camera systems etc. Once the alarm is triggered, this data may be conveyed to external peripherals e.g. for the purpose of notifying the police or the house keeper of the lock snapping attempt. This data may be conveyed in many ways through use of wired or wireless communication devices. The connector ( 14 ) may additionally be used for establishing connection with an external buzzer who may generate a much higher level of audible noise for alerting the neighborhood. The energy consumed by the external connection apparatus ( 16 ) may be supplied either by an external battery or by the mains line.
[0063] The alarm incorporated cylinder lock may be equipped with an external buzzer box ( 17 ) as shown in FIGS. 8 and 9 . The buzzer box ( 17 ) may also contain additional battery for energizing a second buzzer or, precautionary, also the electronic circuit board ( 5 ) contained in the first cylinder half.
[0064] The cylinder lock according to the invention may further comprise, within the second cylinder half ( 22 ), a spring loaded block pin ( 23 ) for blocking the gap of said rod ( 2 ) once the rod ( 2 ) slides out of said second cylinder half ( 22 ) such that re-insertion of said rod is eliminated. If the gap of the rod remains vacant, it may be possible that the alarm may be de-activated by inserting a thin metal object, or back inserting the same rod ( 2 ) itself, into the gap and by filling the gap in between the magnet ( 13 ) and the magnetic switch ( 3 ). If an object is inserted in between the magnet ( 13 ) and the magnetic switch ( 3 ), the alarm circuitry may cease to indicate the break-in attempt as the alarm circuitry may be deceived by the inserted object pretending as part of the rod interposed in between the magnet ( 13 ) and the magnetic switch ( 3 ). Therefore, a spring loaded block pin ( 23 ) may conveniently be used for blocking the gap of the rod ( 2 ) within the second cylinder half ( 22 ) and thereby preventing insertion of an object in between the magnet ( 13 ) and the magnetic switch ( 3 ). The block pin ( 23 ) may be employed in any of the embodiments outlined so far in this text. | A cylinder lock having a first cylinder half, which in use, is mounted on the indoor side and a second cylinder half, which in use, is mounted on the outdoor side of a door, is disclosed. The cylinder lock further comprises a notch cut out on the outdoor end of the second cylinder half for forming a breakable tip portion on said second cylinder half. A rod extends along the second cylinder half and enters, partly at its first end, in the first cylinder half. The rod is secured, at its second end, to the tip portion of the second cylinder half. The cylinder lock further comprises a volume formed on said first cylinder half for accommodating an alarm circuitry including at least an electronic circuit board, a magnetic switch and a magnet. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to light spot scanning, and more particularly to scanning with a spot of light generated holographically.
The primary function of a scanning system is the controlled sampling, or restoration, of information. In an optical scanning system, the information is processed either in parallel by a light beam which can simultaneoulsy illuminate many data sites, or sequentially by a beam which, due to its size, illuminates only a single data site at a time. Interest in sequential optical scanning has expanded in recent years, primarily because of new capabilities provided by laser light. Laser scanners are capable of generating high resolution images at high scan rates. Most of the scanning systems devised to manipulate a laser beam include a galvanometer, rotating mirror, acousto-optic element, or electro-optic element as the light deflector. It was first demonstrated in 1967 that a rotating hologram can also serve as a deflector element in an image scanning system.
Laser line scanners used for imaging applications are generally required to generate a repetitive single scan line. A problem which has been encountered with multi-faceted rotating mirror line scanners is that due to the facet-to-facet nonuniformities and spinner wobble, noncollinear multiple scan lines are formed. An obvious solution to this problem is to fabricate the spinner assembly to such precise mechanical and optical tolerances that the residual error does not detract from the desired level of image quality. The expense of this approach, however, is a decided disadvantage. Holographic scanning provides an alternative by which this problem can be minimized.
In a typical arrangement for making a flat holographic spinner, a point light source serves as the object and a normally incident plane light wave as the reference beam. When a hologram thus constructed is illuminated with a plane light wave which is the inverse of the original reference beam, the hologram functions to reconstruct the original propagating wavefront which converges to form an image of the original point light source. When the holographic spinner is then rotated about the axis of the reference beam, the reconstructed image spot scans a circle in space.
It is an object of this invention to provide a holographic scanner which is insensitive to mechanical wobble during rotation.
Another object is to provide a general method of fabricating a holographic scanner which is essentially insensitive or invariant with respect to mechanical wobble.
Other objects, advantages, and features of this invention may become apparent from the following more detailed description given in connection with the accompanying drawing.
DRAWING
FIG. 1 is a schematic illustration of a scanning system in which a holographic spinner is used to generate a scanning spot of light.
FIG. 2 is an enlarged representation of the spatial geometry of a hologram relative to incident and diffracted light rays.
FIG. 3 shows a part of the system of FIG. 1, somewhat enlarged, representing the holographic reconstruction process.
FIG. 4 is a curve showing angular deviation of the reconstructed image as a function of angular deviation of the hologram.
FIG. 5 is a schematic illustration of an alternate embodiment of this invention.
DESCRIPTION
Referring now to FIG. 1, a holographic spinner is shown at 2 mounted for rotation on a shaft 4. The holographic spinner 2 is a transmission-type hologram and disposed in the path of a reconstruction light beam 6 which, after transmission through the hologram, is a reconstruction of the original interfering light wave front to which the hologram was originally exposed. The hologram was originally exposed to interfering object and reference beams, the object beam emanating from a point source of light. Thus, the hologram contains information for the reconstruction of the point source and the locus of this reconstructed point source as the holographic spinner is spun on the axis 4 is a circle in space. The spinner 2 can be sectioned into a plurality of holographic facets which are analogous to the several facets of a polygon mirror scanner. It is known in the art of holography that repeated exposures can increase the density of information contained in the hologram. This is not material to the present invention but is mentioned here since it may be preferred to generate simultaneously a plurality of scanning light spots.
Holographic spinner 2 is driven by a suitable motor, not shown but indicated by the arrow 8.
Reconstruction light beam 6 emanates from a laser or other source of coherent light 10. A modulator 12 is disposed in the path of light beam 6 to provide the desired modulation to the light beam for the purpose of "writing" with the scanning light spot. A lens 14 and reflector 16 are provided to control the light beam 6 and direct it as desired onto the holographic spinner. Light beam 6 is represented only by its principal ray, incident upon the holographic spinner at an angle φ i . The holographic spinner diffracts the light beam 6 at an angle of diffraction φ d . A reflector 18 directs the light from hologram 2 and the light spot generated by the hologram to a scan surface 20 which may be a Xerographic plate or some other photosensitive surface. Surface 20 is represented as moving in a direction normal to the direction of scan by the light spot to effect raster scanning over the two-dimensional surface.
In order to evaluate how the angular direction of a diffracted ray from a hologram is affected by tilting the hologram, the directions of both refracted and diffracted light rays traversing the hologram are to be considered. Illustrated in FIG. 2 is an enlarged cross section of a hologram which is tilted by an angle θ with respect to fixed X-Y coordinates in space. It will be assumed that the hologram was originally formed so that the normal to its surfaces (shown as a dashed line in FIG. 2) was parallel to the X axis and, therefore, φ i and φ d are respectively the angles that the reference and object light waves made with the hologram during its exposure or recording process.
It is worthwhile at this point to define how the different angles which will be used in the following derivation are measured. The notation conventions which will be observed here are: The subscripts i and d refer to incident and diffracted light waves respectively; the subscript R means that the parameter to which it is connected is measured within the holographic medium; the index n 1 is the assumed refractive index of the medium, such as air in which the hologram is disposed; the index n 2 is the assumed refractive index of the holographic medium; variables noted with a prime superscript (eg. φ') mean that they are measured with respect to the hologram normal, whereas unprimed variables are measured with respect to the fixed X-Y coordinates.
Two basic equations are now the starting points of this derivation: Snell's Law
n.sub.1 Sin φ.sub.1 =n.sub.2 Sin φ.sub.2 (1)
and the grating equation
Sin φ.sub.i +Sin φ.sub.d =λ/d (2)
where λ is the light wavelength and d the grating period. For the first input surface we have:
n.sub.1 Sin φ.sub.i '=n.sub.2 Sin φ.sub.iR.sup.' (3)
and since φ i '=φ i +θ, this equation can be rewritten as:
n.sub.1 Sin (φ.sub.i +θ)=n.sub.2 Sin φ.sub.iR.sup.'(4)
The change in φ iR ' due to the tilt angle θ is calculated by differentiating Equation (4) with respect to θ: ##EQU1## At the grating plane interface we have: ##EQU2## φ dR 40 is not indicated in FIG. 2 but is the diffraction angle measured in the holographic medium with respect to the hologram normal.
The change in φ dR ' to the tilt angle is: ##EQU3## Substituting from Equation (5) gives: ##EQU4## At the last surface we have:
n.sub.2 Sin φ.sub.dR.sup.' =n.sub.1 Sin φ.sub.R.sup.'(9)
Differentiating this equation with respect to θ gives: ##EQU5## Substituting from Equation (8) gives: ##EQU6## The change in the angular direction of the diffracted beam with respect to the fixed X-Y coordinates is obtained with the following coordinate transfer:
φ.sub.d.sup.' =φ.sub.d -θ (12)
Utilizing this equation, the desired result is obtained: ##EQU7##
It is apparent from Equation 13 that when φ i =φ d , φ d does not change for small values of θ. A holographic spinner, therefore, fabricated with φ i =φ d will reconstruct an image whose position is invariant with respect to small tilt angles of the spinner.
To verify the validity of equation 13, two holograms were fabricated and the relative angular sensitivity of their reconstructed real image measured as a function of the tilt angle of the hologram. The first was fabricated to satisfy the invariant condition of equation 13, φ i =φ d . The second hologram was formed with φ i =0° and φ d =60°, ie. a reference beam normally incident on the hologram.
Theoretical and experimental data for the two holograms investigated are given in the graph of FIG. 4. The horizontal axis of this graph represents the tilt angle θ of the hologram. The vertical axis is the relative change, dφ d , in the angular orientation of the reconstructed image or light spot. The experimental data points for the hologram with φ i =φ d =45° are represented by the triangles, while the data for the hologram with φ i =0° and φ d =60° are represented by circles. The theoretical curves are respectively labeled. The close correspondence between the theoretical and experimental data attests to the validity of equation 13. Briefly, the graph points out that the deviation of the reconstructed image or light spot is practically nil through a tilt of the hologram of plus or minus 4° when φ i =φ d . By comparison, there is a one-to-one relationship between hologram tilt and image deviation where φ i =0° and φ d =60°.
The principle of the invariant holographic image, demonstrated above, finds practical application in a holographic scanner as represented in FIG. 1. The holographic spinner which reconstructs a light spot that will stay in its desired scan locus despite a small wobble or tilt in the spinner will have decided advantages.
As has been developed above, the first constraint on the reconstruction wavefront 6 is that it be directed so that φ i =φ d . The other major constraint upon the reconstruction wavefront 6 is that it be essentially radially symmetrical relative to the axis of rotation of the holographic spinner 2. This constraint arises as a requirement to minimize aberrations at every point in the scan field of interest. A collimated reconstruction beam which is normally incident on a flat holographic spinner clearly satisfies the symmetry requirement since it has a spatial phase variation at the spinner which is independent of rotation of the spinner. By the same reasoning, a reconstrucion wavefront which originated from a point on the axis of rotation of the spinner would also have a spatial phase variation on the spinner which is invariant with respect to its rotation. FIG. 3 schematically illustrates a reconstruction wavefront equivalent to one which originated on the axis of rotation of the spinner 2. In FIG. 3, the reconstruction wave 6 is depicted as converging to a point on the axis 4, which from a symmetry standpoint is equivalent to a wave which originates from that axial point. The incident convergent wavefront 6i of FIG. 3 is the same light beam 6i shown in FIG. 1, having been caused to converge by lens 14.
In the system shown in FIG. 3, only the principal ray exactly satisfies the invariant condition. A tilting of the hologram does not change the angular direction of the diffracted beam from the scanner of FIG. 3, but does introduce a degree of astigmatic aberration into the beam. For positive tilt angles, the tangential rays come to focus behind the sagittal rays while for negative tilt angles, the tangential rays come to focus before the sagittal rays.
An alternative embodiment of this invention is represented in FIG. 5 in which a conically shaped holographic spinner 22 is disposed for rotation on the shaft 4 and in the path of a reconstruction light beam 6. A plurality of holographic facets are shown at 24. A feature of this arrangement is that the reconstruction beam 6 can be a collimated beam, and parallel to the axis of the system as shown, whereas in the arrangements of FIGS. 1 and 3, it is necessary to take the additional measures to make the reconstruction beam the equivalent of one having originated on the axis of the system.
The present invention can be summarized by the following two properties. First is a hologram providing an invariant condition, in which a holographically reconstructed light spot is not subject to perturbations despite mechanical wobble of the hologram. This results when φ i =φ d . Second the radially symmetrical illumination of such a hologram by a reconstruction wavefront, while spinning, produces a desired substantially aberration-free spot scan of the reconstructed light spot.
The present invention permits construction of holographic spinner-scanners that are less sensitive to mechanical wobble in the spinner by over a factor of 10 as compared to typical flat spinner designs in which the reference and reconstruction light beams are normally incident on the hologram, φ i =0° and φ d =some other angle. The practical result of this is that a spinner constructed according to this invention, even if it should experience some small amount of wobble, will produce a satisfactory line image for most imaging applications without the use of additional corrector optics.
The foregoing description of this invention is given by way of illustration and not of limitation. The concept and scope of the invention are limited only by the following claims and equivalents thereof which may occur to others skilled in the art. | A holographic spinner reconstructs a light spot to rapidly scan a narrow line on a suitable "write" surface to generate an image. The geometry of the holographic spinner with respect to the holographic reconstruction light beam is such that the position of the regenerated light spot is insensitive to mechanical wobble which might be present in the spinner mechanism. | 6 |
BACKGROUND OF THE INVENTION
German Published Patent Application 23 39 896 shows a circuit including an element having a specific breakdown voltage coupled to the control electrode of the switching transistor in the primary circuit between the primary winding and the contact-break distance of the ignition transistor. If the voltage exceeds a permissible value when the contact-break distance of the ignition transistor makes the transition to the nonconducting state, then the voltage at the element having a specific breakdown voltage breaks through, and a control current begins to flow across the control path of the ignition transistor, which control current again makes the emitter-collector path of the ignition transistor somewhat permeable to current. As a result, the voltage at the contact-break distance of the ignition transistor drops again, and, in fact, continues to drop until the voltage at the switching element having a specific breakdown voltage falls below this breakdown voltage. This configuration comprising the element having a fixed breakdown voltage (Zener diode) cannot ensure overvoltage protection for all operating ranges. For example, if one designs the ignition system and, thus, the element having a specific breakdown voltage, so as to allow an adequate secondary voltage to still be provided for all operating states, given a large secondary load, then larger values can occur on the parts energized with high voltage, given a low secondary load. Such an overloading can lead to their destruction, when, for example, a spark plug connector drops out and a breakdown occurs across the high-voltage insulation.
As such, conventional systems work with a fixed primary Zener-type characteristic as a voltage bracketing of the ignition transistor and, thus, do not provide a satisfactory compromise between a sufficient secondary voltage supply and high-voltage strength of the parts that are energized with high voltage.
SUMMARY OF THE INVENTION
In accordance with the present invention, an ignition system for an internal combustion engine includes an ignition coil and an ignition output stage in the primary circuit of the ignition coil. Current through the primary circuit, and as a result a voltage at the secondary winding at the ignition spark, is dependent upon a bracketing voltage of a bracketed circuit arrangement. The bracketing voltage is dependent upon a primary voltage and an output of an evaluation unit which are coupled to the bracketing circuit arrangement. The evaluation unit monitors the primary voltage to determine whether the ignition coil has a high secondary load or a low secondary load. The evaluation circuit then induces a high bracketing voltage on the bracket circuit arrangement if it determines that there is a high secondary load and induces a low bracketing voltage on the bracket circuit arrangement if it determines that there is a low secondary load.
It is particularly advantageous that an optimal voltage value is made available in each case for an ignition spark by evaluating the rise time of the primary voltage. Furthermore, it is especially advantageous that the voltage reached in the primary winding after expiration of a specifiable time is able to be evaluated as a measure for the secondary load. Thus, one can react immediately to altered operational conditions.
Finally, the advantage of detecting the load acting on the secondary side is that this provides an indication of the available ignition voltage supply. Thus, for example, the rise time of the primary voltage or the attainment of a predetermined primary voltage value within a specifiable time can be evaluated as a measure for the ignition-voltage supply. Another advantage of this primary-side acquisition of the ignition-voltage supply on the secondary side of the ignition coil is that it can be drawn upon during normal operation of the engine for diagnostic evaluation, to recognize possible errors in the ignition system. Thus, a flat rise in the secondary voltage is an indication that a spark plug connector is exhibiting shunt firing. If, on the other hand, the detected spark duration is less than a limiting value, or rather if the spark voltage characteristic typical of combustion is absent, then an ignitable mixture is lacking, for example, or an ignition spark is possibly lacking at the spark plug due to a spark plug connector that has dropped out.
It is possible to detect the actual high voltage being provided, for example, by removing a spark plug connector and making appropriate measurements, however this is not practical during operation of the internal combustion engine. In this case, the evaluation as described above offers a simple solution for detecting ignition voltage.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the basic structure of a variable output-stage Zener-type characteristic in accordance with the present invention;
FIG. 2 illustrates the relationship between the secondary load and the rise characteristic of the primary voltage; and
FIG. 3 shows a flow-chart for detecting and evaluating the primary voltage.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 depicts an ignition device in accordance with the present invention for an internal combustion engine (not shown). The primary winding 1 of the ignition coil 2 is connected, on the one hand, to the supply voltage U B and, on the other hand, via the collector-emitter path of the ignition transistor 3 and a resistor 4 to ground. A load, represented here in the equivalent circuit diagram by the parallel connection of a capacitor 6 and a resistor 7, acts upon the secondary winding 5 of the ignition coil 2. To detect the primary voltage, a tap 8 is provided between the primary winding 1 and the ignition transistor 3, so that the primary voltage U P is evaluated in an evaluation unit 9, the rise characteristic of the primary voltage U P being a measure for the secondary load when an ignition pulse is triggered. An additional tap 14 between the primary winding and the ignition transistor 3 is run via a resistor 10 and a Zener diode 11 to the control input of a transistor 12. The collector of the transistor 12 is run via a resistor 15 to a 5 -volt supply voltage, while the emitter of the transistor 12 is run to a connection between a control terminal 13 for the ignition signal and the control input of the ignition transistor 3. A third transistor 16 is run on the collector side to the connection between the resistor 10 and the Zener diode 11 and is connected to ground on the emitter side. The control input of this third transistor 16 is connected to the evaluation unit 9.
The above-described ignition system has the following mode of operation. The ignition transistor 3 is initially forced by the control terminal 13 into the conducting state, so that the primary winding 1 of the ignition coil 2 is traversed by current flow. At the end of the signal at the control terminal 13, the ignition transistor 3 attains the non-conducting state, which results in an interruption of the current flow in the primary winding 1 of the ignition coil 2 and, in dependence upon this, in a high-voltage surge in the secondary winding 5. This would then lead on the secondary side to an ignition spark on a spark plug (not shown). Now, if the voltage exceeds the permissible value when the ignition transistor makes the transition into the non-conducting state, then the voltage at the Zener diode 11 breaks through, and a control current is applied to the control input of the transistor 12, so that a control current at the ignition transistor 3 again makes this transistor somewhat permeable to current. As a result, the voltage across the contact-break distance of the ignition transistor 3 drops again immediately and, in fact, continues to drop until the voltage at the Zener diode 11 falls below the breakdown voltage of this Zener diode. This is a generally known voltage bracketing of the ignition transistor 3, the primary voltage U P , which the Zener diode 11 functions in response to, being described as bracketing voltage. At the tap 8, the primary voltage U P is acquired in the evaluation unit 9 and evaluated such that the voltage building up at the Zener diode 11 can be varied by triggering the transistor 16, i.e., the transistor 16, together with the resistor 10, forms an adjustable voltage divider, the voltage being applied to the middle of the adjustable voltage divider corresponding to the voltage that is applied to the Zener diode 11. The electric potential being applied to the Zener diode is varied in dependence upon the triggering of the transistor 16. For this purpose, primarily the rise time tr of the primary voltage U P is evaluated up to a specified value in the evaluation unit 9. Thus, a large capacitive load on the secondary side results in a longer rise time tr than in the case of a small capacitive load. When there is a long rise time tr, thus in the case of a high capacitive load, the transistor 16 is powered up with a correspondingly large voltage, and the electric potential acting on the Zener diode 11 is reduced. Contrary to this, in the case of a low load of the transistor 16, it is powered up to a correspondingly lesser extent, so that the Zener diode 11 reaches the breakdown voltage considerably earlier than in the case of a high capacitive load.
FIG. 2 depicts the relationship between the secondary load and the rise time tr of the primary voltage. The table in FIG. 2 is divided into two sections; part a) for larger loads in the secondary electric circuit and part b) for smaller loads. These sections are distinguished in that in each case two different loads were used for the measurement. The table illustrates the rise time tr, which corresponds to the time of the rise of the primary voltage from 0 to 200 V, the voltage change dU 1 (during 25 μs), and the voltage change dU 2 (during 50 μs). It can clearly be inferred from this table in FIG. 2 that in the case of the load illustrated in part a) of the table (compare the values at C-6 and R-7), a substantially longer rise time tr elapses until 200 volts primary voltage are reached than elapses in the case of the load illustrated in part b) of the table. Thus, one can clearly recognize that a direct correlation exists between the rise time and the secondary load. This correlation is evaluated in the evaluation unit 9, and the transistor 16 is triggered accordingly.
Another possibility for detecting the secondary load is given in that after a specifiable time (for example 25 μs or 50 μs), the voltage change dU P is detected by the evaluation unit 9. It is also apparent here from FIG. 2 that the electric potential in part b) of the table is substantially greater after the same time, given a smaller load, than the electric potential in part a) of the table.
FIG. 3 shows one possible way to evaluate the detected primary voltage U P . Thus, the primary voltage U P is detected in one work step 20, as already described for FIG. 1, either the rise time tr until 200 V primary voltage U P are reached or the attained primary voltage U P being capable of being evaluated after a specifiable time. In the subsequent work step 21, the detected primary voltage U P is evaluated as a measure for the acting secondary load, in that, for example, the rise time until 200 V are reached is analyzed, and in the work step 22, the bracket voltage as described for FIG. 1, is established through an appropriate triggering of the transistor 16.
In the work step 23, the detected primary voltage is compared to reference values U REF of the spark duration and/or of the spark voltage characteristic. At this point, it is checked in the query 24 whether the detected quantities lie within the range of the specifiable limiting values U REF . If this is the case, then the evaluated ignition is recognized as being correct in work step 25. A no in response to question 24 leads to the work step 26, in which the ignition that has taken place is evaluated as being faulty, it being possible at the same time, to subdivide the faults into different types of faults on the basis of the evaluated spark voltage. Thus, from the lack of an overshoot when the voltage breaks through, or rather from a flat voltage rise, one can infer shunt firings on the spark plug. At this point, an error-indication signal is output in work step 27, and the combustion that follows is evaluated in the work step 28. Given too small a rise in the primary voltage and the inference that possible shunt firings exist, for example, the evaluation unit 9 of FIG. 1 enables the secondary voltage supply to be increased through an appropriate bracketing U KL , in order to thus effect a self-cleaning of the spark plug. | An ignition system for internal combustion engines serves as a bracket circuit arrangement (10, 11, 12, 16) to limit the primary voltage, in order to protect parts energized with high voltage from being destroyed. The ignition system comprises a voltage bracketing of the ignition transistor (3), the bracketing voltage being variable in dependence upon a secondary-side load. The primary voltage (U P ) is acquired by an evaluation unit (9) and, given a high secondary load, a high bracketing voltage is used and, given a low secondary load, a low bracketing voltage is used. | 5 |
BACKGROUND OF THE INVENTION
The present invention is directed to a branch component comprising light waveguides in particular for distributing light from an incoming light waveguide between outgoing light waveguides or for collecting light from a plurality of incoming light waveguides into a single outgoing waveguide.
A branch component of this type represents a fundamental requirement for an optical communication technology. For example, these branching components are required for wavelength multiplexers or demultiplexers. For this reason, a branch component should be produced as easily as possible and with a process which is largely standardizable with regard to the technology required.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a branch component which can be produced particularly easily with available technology and which can be used as an optical collector, as a wavelength multiplexer, or as a demultiplexer, or which component can be used to construct these devices.
The object of the present invention is realized by a branch component comprising a carrier body having seven light waveguides and at least three partially transmissive reflective layers disposed thereon. The waveguides are arranged with the first, second and third waveguides being arranged in a longitudinally extending first series and a fourth and fifth waveguides being arranged in a longitudinally extending second series, each of the said adjacent waveguides in said series having a longitudinal axis being displaced less than a minimum displacement and inclined at less than a maximum permissible angle to insure light transfer therebetween. A first reflective layer is disposed between the first and second waveguides of the first series, a second reflective layer is disposed between the second and third waveguides, and a third reflective layer is disposed between the fourth and fifth waveguides of the second series with each of said second reflective layers being arranged to extend obliquely to the longitudinal axis of each of said waveguides. The second series of waveguides is arranged relative to the first series with the fourth waveguide engaging the first waveguide and being disposed on the same side of the first reflective layer. A sixth waveguide is arranged relative to the second waveguide to extend substantially parallel to the fourth waveguide and to be disposed on the same side as the second waveguide from the second reflective layer and a seventh waveguide extends substantially parallel to the first waveguide and is disposed relative to the fourth waveguide to be disposed on the same side as the third reflective layer. The oblique angles of each of the reflective layers are arranged so that the beam traveling in the first waveguide is partially reflected by the first layer into the fourth waveguide with the remaining portion passing into the second waveguide, the remaining portion in the second waveguide is partially reflected into the sixth waveguide by the second layer with the second layer passing a portion into the third waveguide and the portion reflected by the first layer into the fourth waveguide is partially reflected into the seventh waveguide by the third layer which will pass a portion into the fifth waveguide.
The term "maximum permissable displacement" signifies the amount of lateral displacement which is dependent upon the spacing between the two end surfaces of the waveguides that face each other and allow the transmission of the light between the two waveguides with the light intensity which is being transmitted between the two light waveguides being predetermined. The term "maximum permissable angle" is the maximum angle between the axes of the two waveguides, which angle still allows transmission of light therebetween. The acceptance angle of the light waveguides can be taken as a guide for the maximum permissable angle.
A particularly effective process for the production of the proposed component comprises providing a carrier body, forming a main groove in a flat surface of the carrier body, forming first and second branch grooves extending from opposite sides of the main groove at an angle thereto, forming a third branch groove from one of said first and second branch grooves at a distance from the main groove, placing a light waveguide in the main groove, placing light waveguides in the first and second groove abutting against the waveguide in the main groove and placing a waveguide in the third branch groove abutting the waveguide in the one groove which is intersected by the third branch, splitting the body into a plurality of parts by a plurality of cuts extending at a right angle to the flat surface of the body with a cut being positioned at each intersection of grooves and the cut forming an acute angle with the two grooves in such a manner that only one of the two light waveguides in the grooves is fully separated, polishing each of the cut surfaces to a desired finish to produce a pair of polished surfaces, applying a partially transmissive reflective layer to one of each pair of polished surfaces, said reflective layer covering a polished cut surface of one of the waveguides, and then reassembling and fixing the parts together so that each pair of polished surfaces lay opposite each other and are separated by the respective reflective layer.
While the above method will produce the device, it is preferred that it be further modified so that the first and second branch grooves extend parallel to one another with the spacing between their axes equal to the spacing betwen the main groove and the third branch groove which also extend parallel to each other. Said first and second branch grooves are at right angles to the main groove and each of the cuts is made at a 45° angle to each of the intersecting grooves. A branch component as proposed can be particularly advantageously used to construct wavelength multiplexer or demultiplexer systems which have a tree-like branching system.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a carrier body provided with grooves in accordance with the method of the present invention; and
FIG. 2 is a plan view of a branch component of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The principles of the present invention are particularly useful when incorporated into a branch component generally indicated at 4 in FIG. 2. To produce the component, the process provides a carrier body or substrate such as a silicon plate 4', which as illustrated has a squared configuration in FIG. 1.
A main groove 50 is formed into a flat surface of the carrier body 4' with first and second branch grooves 60 and 80 being formed to extend from opposite sides of the main groove 50. A third branch groove 70 is formed to extend from one of the branch grooves such as the branch groove 60. It is noted that the formation of each of the branch grooves 60, 70 and 80 as well as the main groove 50 can be accomplished by means of anisotropic etching. It is also possible to form the grooves by cutting or milling the grooves into the surface which will result in the branch grooves having the extended portions illustrated in dashed lines. The main groove and the groove 70 are parallel to each other and are also parallel to a pair of edges of the carrier plate or body 4'. As illustrated, the grooves 50 and 70 are spaced inward from each of the edges the same distance. The branch grooves 60 and 80 are also parallel to each other and extend perpendicular to the axis of the groove 50 and thus are parallel to the other pair of edges of the body 4'. The grooves 80 and 60 are also displaced inward from the parallel edges a distance equal to the distance of displacement for the grooves 50 and 70. Thus the grooves 50 and 70 are the same distance apart as the grooves 60 and 80 are apart.
After forming the groove, the next step includes assembling the light waveguides into the grooves and an example of a desired light waveguide is a multimode glass fiber having a core surrounded by a cladding layer. It is desirable that the light waveguide or fiber that is to be in the main groove 50 is first assembled in the main groove. The light waveguides such as the optical fibers for the first and second branch grooves 60 and 80 are then inserted with their ends abutting against the light waveguide in the main groove 50. Finally, the light waveguide for the groove 70 is inserted with its end abutting the waveguide in the groove 60.
After each of the light waveguides has been inserted, they may be secured in their respective grooves by using an appropriate adhesive such as an optical cement. It is also expedient to fix the light waveguides in the grooves by means of a covering plate consisting, for example, of glass which will serve to cover the light waveguides and which plate is firmly connected to the flat surface of the plate 4'.
After assembling and securing the waveguides in their respective grooves, the body formed in this manner is then split up into four parts by a cutting or dividing disc or the like. Since the distance between the grooves 70 and 50 is equal to the distance between the grooves 60 and 80, the distance between the longitudinal axes of the waveguides in the groove 70 and the groove 50 is equal to the distance between the longitudinal axes of the waveguides inserted into the grooves 60 and 80. The cuts, which are at right angles to the flat surface of the carrier body 4', can be made along the lines I--I and the lines II--II as illustrated in FIG. 1, and in the present example these two lines I--I and II--II are identical to the diagonals of the square flat surface of the carrier body 4'.
The pair of cut surfaces formed by a cut are then polished to provide a pair of polished surfaces of the desired optical quality. It is noted that this polishing step is a conventional polishing step. A partially transmissive reflective layer is then applied to one of each pair of polished surfaces and will cover the polished cut surface of the fully separated light waveguide. Then the divided components or parts are reassembled and fixed so that the polished surfaces of each pair lie on opposite sides of a reflective layer and a longitudinal axis of the fully separated light waveguides are realigned as far as possible. It should be ensured that at each branching point, the branching light waveguide is not effected by the cutting and polishing steps.
As best illustrated in FIG. 2, the cutting along the diagonals will cut the waveguide in the groove 50 into three waveguides 51, 52 and 53. In a similar manner, a cutting of the waveguide in the branch groove 60 will form waveguides 61 and 62. It is also noted that the cutting did not effect either of the waveguides 7 or 8 which were in the grooves 70 and 80.
After the steps of polishing, reassembling of the parts and the securing and fixing of them together, the branch component 4 of FIG. 2 is formed. The component 4 is composed of four parts 41, 42, 43, and 44 and the partially transmissive reflective layer such as F 1 , F 2 and F 3 .
As illustrated, the partially transmissive layer F 1 separates the waveguide 51 from the waveguide 52 and the partially transmissive layer F 3 separates the second waveguide 52 from the third waveguide 53. It is noted that a fourth waveguide 61 branches from the first waveguide 51 and lies on the same side therewith from the layer F 1 . It is also noted that the longitudinal axes A 1 and B 1 of these two waveguides 51 and 61 extend at right angles to each other and intersect on the surface of the reflective layer F 1 facing these two waveguides. A light waveguide 8 is adjacent the reflective layer F 3 , extends to the left of the second waveguide 52 at right angles therewith. The longitudinal axes C 1 and A 2 of these waveguides 8 and 52 intersect on the surface of layer F 3 which faces towards these waveguides. The reflecting layer F 2 separates the fourth waveguide 61 from the fifth waveguide 62. It is noted that a seventh waveguide 7 has an axis C 2 that extends perpendicular to the axis B.sub. 1 and the waveguide 7 is on the same side as the waveguide 61 from the layer F 2 . The axes B 1 and C 2 intersect on a surface of the layer F 2 .
It is also noted that due to the fact that the waveguides 51, 52 and 53 were formed from the single waveguide during the cutting step, their axes A 1 , A 2 and A 3 are substantially in alignment in a longitudinally extending direction. Also the axes B 1 and B 2 of the fourth waveguide 61 and the fifth waveguide 62 are also in alignment and extend at right angles to the axes A 1 , A 2 and A 3 . It is noted that the reflective layers F 1 , F 2 and F 3 are inclined to each axis by 45° and that the plane formed by the layer F 1 is perpendicular to the common plane formed by the layers F 2 and F 3 .
The production of the body having the grooves can be done by taking a large silicon disc. A flat surface of the disc is etched to form a first group of parallel equidistant grooves and at right angles to this first group of grooves, a second group of parallel equidistant grooves are etched. It is also possible to use a square plate such as illustrated in FIG. 1 in which case the grooves 60, 70 and 80 can be extended as illustrated in broken lines.
The partially transmissive reflective layers F 1 , F 2 and F 3 , which are applied to the polished surfaces of each pair of polished surfaces can consist of metallic reflective layers composed, for example, of aluminum and can have equal or differing transmissive capabilities. However, they can also consist of dielectric multiple layers of arbitrary design with regard to the spectral curve of the transmission/relection capacity. These multiple layers can be formed, for example, of SiO 2 /TiO 2 alternating layers.
The provision of a part such as 41, 42, 43 and 44, with a reflective layer is already described in a copending U.S. patent application Ser. No. 093,519, filed Nov. 13, 1979 and based on German application No. P 28 51 679. In this application, the cementing of cut surfaces after shaping or polishing ensures that the fiber axis of the two portions joined together such as the portion 42-44 or 41-44 will have the fiber aligned as disclosed in the prior application. This is particularly true if an assembly device having positioned stop means is used. The double diagonal division for the two cutting planes of the present invention serves to compensate for cutting losses.
The described arrangement can be constructed as either a simple light branching element or component which is provided with one input at the first waveguide 51 and four outputs at the third waveguide 53, the fifth waveguide 62, the sixth waveguide 8, and the seventh waveguide 7 or the four inputs formed by the waveguides 8, 53, 7, 62 and one output formed by the first waveguide 51. In addition, a wavelength multiplexer or demultiplexer for four different light wavelengths can be formed by this component. If the component is used as a multiplexer or demultiplexer, the polished diagonal cut surfaces are expediently vaporized with the dielectric multilayer cut out filters, which transmit long waves or short waves. In the case of a demultiplexer, the filter formed in the reflective layer F 1 between the first and second waveguides 51 and 52 is provided to transmit a group of two of the four wavelengths into the waveguide 52 while reflecting the other two wavelengths into the fourth waveguide 61. The filter arranged between the second waveguide 52 and the third waveguide 53 is constructed to reflect one of the two wavelengths or a subgroup into the sixth waveguide 8 while passing the other wavelength as a subgroup into the third waveguide 53. In a similar manner, the filter in the layer F 2 is constructed to reflect one subgroup or wavelength of the two wavelengths in the fourth waveguide 61 into the seventh waveguide 7 while passing the other wavelength or subgroup into the fifth waveguide 62. When the device is used as a multiplexer, the radiation of the four different wavelengths which are fed in from the exterior at the waveguides 7, 8, 62 and 53 are fed in the reversed direction to the first fiber 51. In the case of a demultiplexer, in order to increase the cross-talk attenuation, it is advantageous to apply narrow band filters which transmit only the desired wavelength to the respective output fibers 7, 8, 53 and 62.
Although various minor modifications may be suggested by those versed in the art, it should be understood that we wish to embody within the scope of the patent granted hereon, all such modifications as reasonably and properly come within the scope of our contribution to the art. | A branch component and method of making the component which can be used either to distribute light from a single waveguide into four outgoing waveguides or to collect light from four incoming waveguides into a single outgoing waveguide. The component includes seven waveguides and at least three partially transmissive reflective layers disposed on the surface of a carrier with the first, second and third waveguides being arranged in a longitudinally extending first series, the fourth and fifth waveguides being arranged in a longitudinally extending second series extending perpendicular to the first series and a first reflective layer separating the first and fourth waveguides from the second waveguide, a second reflective layer separating the second and a sixth waveguide from a third waveguide and a third reflective layer separating the fourth and seventh waveguides from the fifth waveguide and the second and third reflective layer lying on a plane which extends perpendicular to a plane formed by the first reflective layer. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a toroidal-type continuously variable transmission which is used, for example, as a transmission for a vehicle.
2. Description of the Related Art
A toroidal-type continuously variable transmission of a double cavity type used, for example, as a transmission for a vehicle is structured as shown in FIGS. 16 and 17 .
As shown in FIG. 16 , inside a casing 50 , an input shaft (center shaft) 1 is rotatably supported and, on the outer periphery of the input shaft 1 , two input disks 2 , 2 and two output disks 3 , 3 are mounted. Also, on the outer periphery of the middle portion of the input shaft 1 , an output gear 4 is rotatably supported. In the central portion of the output gear 4 , cylindrical-shaped flange portions 4 a , 4 a are formed; and, the output disks 3 , 3 are connected by splint connection to the flange portions 4 a , 4 a respectively.
The input shaft 1 can be driven and rotated by a drive shaft 22 through a loading-cam-type pressing device 12 disposed between the input disk 2 situated on the left in FIG. 16 and a cam plate 7 . Also, the output gear 4 is supported within the casing 50 through a partition wall 13 composed of two members connected together, whereby the output gear 4 can be rotated about the axis O of the input shaft 1 but is prevented from shifting in the direction of the axis O.
The output disks 3 , 3 are supported by needle roller bearings 5 , 5 each interposed between the input shaft 1 and themselves in such a manner that they can be rotated about the axis O of the input shaft 1 .
Also, the input disk 2 situated on the left side in FIG. 16 is supported on the input shaft 1 through a ball spline 6 , while the input disk 2 on the right side in FIG. 16 is spline connected to the input shaft 1 ; and, the two input disks 2 can be rotated together with the input shaft 1 . And, between the inner surfaces 2 a , 2 a (concave-shaped surfaces) of the input disks 2 , 2 and the inner surfaces 3 a , 3 a (concave-shaped surfaces) of the output disks 3 , 3 , power rollers 11 (see FIG. 17 ) are held in such a manner that they can be rotated.
In the inner peripheral surface 2 c of the input disk 2 situated on the right side in FIG. 16 , there is formed a stepped portion 2 b ; and, a stepped portion 1 b formed in the outer peripheral surface 1 a of the input shaft 1 is butted against the stepped portion 2 b , while the back surface (in FIG. 16 , the right surface) of the input disk 2 is butted against a loading nut 9 . Due to this, the input disk 2 is substantially prevented from shifting in the axis O direction with respect to the input shaft 1 . Also, between the cam plate 7 and the flange portion 1 b of the input shaft 1 , a countersunk spring 8 is interposed; and, the countersunk spring 8 applies a pressing force to the respective contact portions between the concave-shaped surfaces 2 a , 2 a , 3 a , 3 a of each disks 2 , 2 , 3 , 3 and the peripheral surfaces 11 a , 11 a of the power rollers 11 , 11 .
Now, FIG. 17 is a section view taken along the line A-A shown in FIG. 16 . As shown in FIG. 17 , inside the casing 50 , there are disposed a pair of trunnions 15 , 15 each of which can be swung about a pair of pivot shafts 14 , 14 disposed at positions twisted with respect to the input shaft 1 . By the way, in FIG. 17 , illustration of the input shaft 1 is omitted.
The two trunnions 15 , 15 respectively include, in their respective two end portions which are situated in the longitudinal-direction (in FIG. 17 , vertical-direction) of a support plate portion 16 , a pair of bent wall portions 20 , 20 which are formed to be bent on the inner surface side of the support plate portion 16 . And, these bent wall portions 20 , 20 form recess-shaped pocket portions P respectively for storing their associated power rollers 11 therein. Also, on the outer surfaces of the bent wall portions 20 , 20 , the pivot shafts 14 , 14 are disposed in such a manner that they are concentric with each other.
A circular hole 21 is formed in the central portion of each of the support plate portions 16 and the base end portion 23 a of a displacement shaft 23 is supported in the circular hole 21 . And, in case where the trunnions 15 , 15 are respectively swung about their associated pivot shafts 14 , 14 , the inclination angles of the displacement shafts 23 supported on the central portions of the trunnions 15 , 15 can be adjusted. Also, on the peripheries of the leading end portions 23 b of the displacement shafts 23 projecting from the inner surfaces of the trunnions 15 , 15 , there are rotatably supported the power rollers 11 ; and, the power rollers 11 , 11 are interposed between the input disks 2 , 2 and output disks 3 , 3 . By the way, the base end portions 23 a and leading end portions 23 b of the respective displacement shafts 23 , 23 are eccentric to each other.
Also, the pivot shafts 14 , 14 of the trunnions 15 , 15 are respectively supported in such a manner that they can be swung and shifted in the axial direction thereof (in FIG. 16 , in the front and back direction; and, in FIG. 17 , in the vertical direction) with respect to a pair of yokes 23 A, 23 B; and, the yokes 23 A, 23 B prevent the trunnions 15 , 15 from moving in the horizontal direction thereof.
As shown in FIG. 18 , each of the yokes 23 A, 23 B is formed into a rectangular shape by press working or forging a blank member made of metal such as steel. In the four corners of the respective yokes 23 A, 23 B, there are formed four circular-shaped support holes 18 , while the pivot shafts 14 disposed on the two end portions of the trunnion 15 are swingably supported on the support holes 18 through radial needle roller bearings 30 .
Also, in the width-direction (in FIGS. 17 and 18 , the right-and-left direction) central portion of each of the yokes 23 A, 23 B, there are formed circular-shaped engaging holes 19 , while the inner peripheral surfaces of the engaging holes 19 are formed as spherical-shaped concave surfaces; and, spherical-shaped surface posts 64 , 68 are respectively fitted into the engaging holes 19 . That is, the yoke 23 A situated on the upper side is swingably supported by the spherical-shaped surface post 64 which is supported on the casing 50 through a fixing member 52 , while the lower-side yoke 23 B is swingably supported by the spherical-shaped surface post 68 and the upper valve body 61 of a cylinder 31 supporting the spherical-shaped surface post 68 .
By the way, the displacement shafts 23 , 23 disposed on the trunnions 15 , 15 are disposed at positions which are opposite by 180° to each other with respect to the input shaft 1 . Also, the direction, in which the leading end portions 23 b of the respective displacement shafts 23 , 23 are eccentric to the base end portions 23 a thereof, is the same direction (in FIG. 17 , the reversed upward and downward direction) to the rotation direction of the two kinds of disks 2 , 2 , 3 , 3 . Also, the eccentric direction is a direction which is substantially perpendicular to the mounting direction of the input shaft 1 . Therefore, the power rollers 11 , 11 are supported in such a manner that they can be shifted slightly in the longitudinal direction of the input shaft 1 . As a result of this, due to elastic deformation of each components based on thrust load generated by the pressing device 12 , even when the power rollers 11 , 11 tend to shift in the axial direction of the input shaft 1 , an unreasonable force can be prevented from being applied to the respective composing parts of the toroidal-type continuously variable transmission and thus the shifting movements of the power rollers 11 , 11 can be absorbed.
Also, between the outer surface of the power roller 11 and the inner surface of the support plate portion 16 so the trunnion 15 , there are interposed a thrust ball bearing 24 and a thrust needle roller bearing 25 , in this order, starting from the outer surface of the power roller 11 which are both thrust rolling bearings. Of these bearings, each of the thrust ball bearings 24 is structured such that, while supporting a thrust-direction load applied to the power roller 11 , it allows the power roller 11 to rotate. Each of the thrust ball bearings 24 comprises a plurality of balls 26 , 26 , a circular-ring-shaped retainer 27 for holding the balls 26 , 26 in such a manner that the balls 26 are allowed to roll, and a circular-ring-shaped outer race 28 . Also, the inner race raceway of each thrust ball bearing 24 is formed in the outer surface of the power roller 11 , whereas the outer race raceway thereof is formed in the inner surface of the outer race 28 .
Also, the thrust needle roller bearing 25 is held by and between the inner surface of the support plate portion 16 of the trunnion 15 and the outer surface of the outer race 28 . And, the thrust needle roller bearing 25 is structured such that, while supporting a thrust load applied to the outer race 28 from the power roller 11 , it allows the power roller 11 and outer race 28 to swing about the base end portion 23 a of their associated displacement shaft 23 .
Further, on the one-end portions (in FIG. 17 , the lower end portions) of the trunnions 15 , 15 , there are disposed drive rods (trunnion shafts) 29 , 29 and, on the outer peripheral surfaces of the middle portions of the drive rods 29 , 29 , there are fixedly mounted drive pistons (oil-pressure pistons) 33 , 33 . And, these drive pistons 33 , 33 are respectively oil-tight fitted into the drive cylinder 31 composed of the upper and lower valve bodies 61 , 62 . The drive pistons 33 , 33 and drive cylinder 31 cooperate together in constituting a drive device 32 which can shift the trunnions 15 , 15 in the axial directions of the pivot shafts 14 , 14 of the trunnions 15 , 15 .
In the case of the thus-structured toroidal-type continuously variable transmission, the rotational movement of the input shaft 1 is transmitted through the pressing device 12 to the respective input disks 2 , 2 . And, the rotational movements of the input disks 2 , 2 are transmitted through the pair of power rollers 11 , 11 to the output disks 3 , 3 and further the rotational movements of the output disks 3 , 3 are taken out from the output gear 4 .
To change a rotation speed ratio between the input shaft 1 and output gear 4 , the pair of drive pistons 33 , 33 may be shifted in the mutually opposite directions. With the shifting movements of the drive pistons 33 , 33 , the pair of trunnions 15 , 15 are shifted in the mutually opposite directions, For example, the power roller 11 on the left side in FIG. 17 is shifted downwardly, whereas the power roller 11 on the right side is shifted upwardly. This changes the directions of tangential-direction forces acting on the contact portions between the peripheral surfaces 11 a , 11 a of the power rollers 11 , 11 and the inner surfaces 2 a , 2 a , 3 a , 3 a of the input and output disks 2 , 2 , 3 , 3 . And, due to such change in the directions of these forces, the trunnions 15 , 15 are swung in the mutually opposite directions about the pivot shafts 14 , 14 pivotally supported on the yokes 23 A, 23 B.
This changes the contact positions between the peripheral surfaces 11 a , 11 a of the power rollers 11 , 11 and the inner surfaces 2 a , 3 a of the input and output disks 2 , 3 to thereby change a rotation speed ratio between the input shaft 1 and output gear 4 . Also, in case where a torque to be transmitted between the input shaft 1 and output gear 4 varies and the elastic deformation quantities of the respective composing parts vary, the power rollers 11 , 11 and outer races 28 , 28 belonging to these power rollers 11 , 11 are slightly rotated about the base end portions 23 a , 23 a of the displacement shafts 23 , 23 . Since the thrust needle roller bearings 25 , 25 are interposed between the outer surfaces of the outer races 28 , 28 and the inner surfaces of the support plate portions 16 respectively constituting their associated trunnions 15 , 15 , the slight rotational movements of the power rollers 11 and outer races 28 can be carried out smoothly. Therefore, the force necessary to change the inclination angles of the displacement shafts 23 , 23 in the above-mentioned manner can be reduced down to a small level.
By the way, the yokes 23 A, 23 B, which support the pivot shafts 14 , 14 of the trunnions 15 , 15 swingably and shiftably in the axial direction, are structured such that, as described above, they can be swung about the spherical-shaped surface posts 64 , 68 (for example, see U.S. Pat. No. 6,117,043). However, conventionally, there has been desired the development of a structure that can swing the yokes 23 A, 23 B more smoothly.
In attaining this desire, in JP-A-9-291997, there is disclosed a technique which can swing the yokes 23 A, 23 B about pins inserted into pin holes formed in the yokes 23 A, 23 B.
However, in this technique, when forming the pin holes in the yokes 23 A, 23 B, the formation positions of the pin holes must be set with high accuracy. This not only makes it difficult to manufacture the yokes 23 A, 23 B but also makes it necessary to provide the pins specially, which results in the increased number of parts used in the toroidal-type continuously variable transmission and in the increased manufacturing cost thereof.
SUMMARY OF THE INVENTION
The present invention aims at eliminating the above drawbacks found in the conventional toroidal-type continuously variable transmission. Accordingly, it is an object of the present invention to provide a toroidal-type continuously variable transmission which not only can facilitate the manufacturing of the yokes but also can reduce the manufacturing cost of the yokes and thus the toroidal-type continuously variable transmission.
In attaining the above object, according to a first aspect to the present invention, there is provided a toroidal-type continuously variable transmission, having a casing; an input disk and an output disk having inner surfaces respectively and rotatably supported concentrically with each other in the casing in such a manner that the inner surfaces are opposed to each other; a plurality of power rollers each held between the input and output disks; a plurality of trunnions each having a pair of pivot shafts disposed at positions twisted with respect to a center axis of the input and output disks and concentric with each other, the trunnion supporting the associated power roller so as to be rotated; a drive device for shifting the trunnions in the axial directions of the pivot shafts; a pair of yokes for supporting the pivot shafts of each of the trunnions so as to be swung and shifted in the axial direction thereof, the yokes being swingable according to the shifting movement of the associated trunnion; and, a pair of opposing members each disposed to he opposed to the associated yoke, wherein the yokes each includes projection portion contacted with the associated opposing member, the projection portion being the fulcrum of the swinging movements of the yokes.
According to the present invention, the projection portions of the yokes are contacted with their associated opposing members (such as a casing or a cylinder for storing therein a piston for shifting the trunnion), whereby the yokes can be swung about these projection portions to thereby synchronize the shifting movements of the trunnions supported on the yokes.
In this manner, since the yokes swing about the projection portions contacted with the opposing members, the yokes are allowed to swing smoothly. Therefore, the shifting movements of the trunnions supported on the yokes can be synchronized stably, thereby being able to stabilize the transmission performance of the toroidal-type continuously variable transmission.
Also, because the structure can be obtained by forming the projection portions in the yokes, the manufacture of the yokes is easy and also there is eliminated the need for special provision of pins, thereby being able to reduce the manufacturing cost of the toroidal-type continuously variable transmission.
According to a second aspect of the present invention, there is provided a toroidal-type continuously variable transmission, having a casing; an input disk and an output disk having inner surfaces respectively and rotatably supported concentrically with each other in the casing in such a manner that the inner surfaces are opposed to each other; a plurality of power rollers each held between the input and output disks; a plurality of trunnions each having a pair of pivot shafts disposed at positions twisted with respect to a center axis of the input and output disks and concentric with each other, the trunnion supporting the associated power roller so as to be rotated; a drive device for shifting the trunnions in the axial directions of the pivot shafts; a pair of yokes for supporting the pivot shafts of each of the trunnions so as to be swung and shifted in the axial direction thereof, the yokes being swingable according to the shifting movement of the associated trunnion; and, a pair of opposing members each disposed to be opposed to the associated yoke, wherein the opposing members each includes projection portion contacted with the associated yoke, the projection portion being the fulcrum of the swinging movements of the yokes.
According to the second aspect of the present invention, the projection portions of the opposing members are contacted with their associated yokes, whereby the yokes can be swung about these projection portions to thereby synchronize the shifting movements of the trunnions supported on the yokes.
In this manner, since the yokes are structured so as to swing about the projection portions formed in the opposing members and contacted with the yokes, the yokes are allowed to swing smoothly. Therefore, the shifting movements of the trunnions supported on the yokes can be synchronized stably, thereby being able to stabilize the transmission performance of the toroidal-type continuously variable transmission.
Also, because the structure can be obtained by forming the projection portions in the opposing members, the manufacture of the yokes is easy and also there is eliminated the need for special provision of pins, thereby being able to reduce the manufacturing cost of the yokes and thus the toroidal-type continuously variable transmission.
According to the present invention, the toroidal-type continuously variable transmission as set forth in the first or second aspect, wherein each of the yokes forms a penetration hole therein, the toroidal-type continuously variable transmission further includes a restricting member inserted into the penetration hole of the yoke and restricting the movement of the yoke in the horizontal direction, and a clearance is formed between the restricting member and the penetration hole.
According to the present structure, since there is formed a clearance between the restricting member and the penetration hole of the yoke, the yoke is allowed to move in the horizontal direction only by the amount corresponding to this clearance. Therefore, even in case where the positions of the contact portions between the peripheral surfaces of the power rollers and the inner surfaces of the input and output disks are caused to vary in the respective power rollers due to the shifted position of the yokes within the casing or due to variations in the assembling positions of the power rollers with respect to the trunnions. The yokes are allowed to move in the horizontal direction to thereby correct the variations in the positions of the contact portions between the peripheral surfaces of the power rollers and the inner surfaces of the input and output disks. Thanks to this, loads to be applied to the respective power rollers can be made uniform, so that the durability of the power rollers is not lowered but the lives of the power rollers can be extended.
Also, because there is eliminated the need to set the positions of the yokes within the casing and the assembling positions of the power rollers with respect the trunnions with accuracy so as to be able to prevent the durability of the power rollers from being lowered, the operation for assembling these composing parts is easy.
Further, according to the present invention, the toroidal-type continuously variable transmission as set forth in the first aspect of the present invention, wherein, in each of the opposing members, a recess portion into which a leading end portion of the projection portion of each of the yoke is inserted is formed.
That is, according to the present structure, by inserting the leading end portions of the projection portions of the yokes into the recess portions formed in the opposing members, the yokes can be swingably supported in the recess portions of the opposing members. Thanks to this, the centers of the swinging movements of the yokes can be made always constant, which makes it possible to stabilize the swinging movements of the yokes.
Also, since there is eliminated the need for provision of posts and pins which are used to support the yokes swingably, there can be avoided not only the operation to form holes in the yokes for insertion of the posts and pins but also the operation to assemble the pins to the yokes, which makes it further easier to manufacture the yokes. Further, no need for provision of the posts and pins can reduce the number or parts and the manufacturing cost of the toroidal-type continuously variable transmission.
In addition, according to the present invention, the toroidal-type continuously variable transmission as set forth in the second aspect of the present invention, wherein, in each of the yokes, a recess portion into which a leading end portion of the projection portion of each of the opposing members is inserted is formed.
That is, by inserting the leading end portions of the projection portions of the opposing members into the recess portions formed in the yokes, the yokes can be swingably supported on the projection portions of the yokes. Thanks to this, the centers of the swinging movements of the yokes can be made always constant, which can stabilize the swinging movements of the yokes.
Also, since there is eliminated the need for provision of posts and pins which are used to support the yokes swingably, there can be avoided not only the operation to form holes in the yokes for insertion of the posts and pins but also the operation to assemble the pins to the yokes, which makes it further easier to manufacture the yokes. Further, no need for provision of the posts and pins can reduce the number of parts and the manufacturing cost of the toroidal-type continuously variable transmission.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a section view of a toroidal-type continuously variable transmission according to a first embodiment of the present invention;
FIG. 2 is a section view taken along the line A-A shown in FIG. 1 ;
FIGS. 3A and 3B each shows a yoke shown in FIG. 1 ; specifically, FIG. 3A is a plan view of the yoke, and FIG. 3B is a side view of the yoke;
FIGS. 4A and 4B are explanatory views of the yoke, showing how the yoke swings in varying the speed ratio;
FIG. 5 is a section view of a toroidal-type continuously variable transmission according to a second embodiment of the present invention;
FIGS. 6A and 6B each shows the yoke shown in FIG. 5 ; specifically, FIG. 6A is a plan view of the yoke, and FIG. 6B is a side view of the yoke;
FIGS. 7A and 7B are explanatory views of the yoke, showing how the yoke swings in varying the speed ratio;
FIG. 8 is a section view of a toroidal-type continuously variable transmission according to a third embodiment of the present invention;
FIG. 9 is a section view taken along the line A-A shown in FIG. 8 ;
FIG. 10 is a plan view of the yoke shown in FIG. 8 ;
FIGS. 11A and 11B are explanatory views of the yoke, showing how the yoke swings in varying the speed ratio;
FIG. 12 is a section view of a toroidal-type continuously variable transmission according to a fourth embodiment of the present invention;
FIG. 13 is a section view taken along the line A-A shown in FIG. 12 ;
FIGS. 14A and 14B each shows the yoke shown in FIG. 12 ; specifically, FIG. 14A is a plan view of the yoke, and FIG. 14B is a side view of the yoke;
FIGS. 15A and 15B are explanatory views of the yoke, showing how the yoke swings in varying the speed ratio;
FIG. 16 is a section view of an example of a concrete structure of a conventional toroidal-type continuously variable transmission;
FIG. 17 is a section view taken along the line A-A shown in FIG. 16 ; and,
FIG. 18 is a plan view of the yoke shown in FIG. 16 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now, description will be given below of the mode for carrying out the present invention with reference to the accompanying drawings. By the way, in the following drawings, like composing elements as in FIGS. 16 to 18 , the same designations are given and thus the description thereof is simplified.
FIGS. 1 to 3 show a first embodiment of a toroidal-type continuously variable transmission according to the present invention. As shown in FIGS. 1 to 3 , in the width-direction (in FIG. 1 , in the front and back direction; and, in FIGS. 2 and 3 , in the right and left direction) middle portions of each of yokes 23 A, 23 B that exist between support holes 18 , 18 , there are formed elongated-hole-shaped penetration holes 69 , 69 through which spherical-shaped surface posts (restricting elements) 64 , 68 can be inserted. The penetration holes 69 , 69 are formed larger than the outside diameter of the spherical-shaped surface post 64 , 68 in the width direction of the yokes 23 A, 23 B and, therefore, as shown in FIG. 2 , between the penetration holes 69 , 69 and spherical-shaped surface posts 64 , 68 , there are formed given clearances S, so that the yokes 23 A, 23 B can play in the width direction. That is, the width-direction movements of the yokes 23 A, 23 B are restricted by the spherical-shaped surface posts 64 , 68 and the yokes 23 A, 23 B can be moved by an amount corresponding to the clearance S.
As shown in FIGS. 1 and 3 , in the longitudinal-direction (in FIG. 1 , in the right and left direction; and, in FIG. 3A , in the vertical direction) outer portions of the penetration holes 69 , 69 of the yoke 23 A, there are formed bow-shaped-plate-like projection portions 70 , 70 projecting toward the fixing member 52 of a casing 50 , that is an opposing member to the yoke 23 A; and, the projection portions 70 , 70 provide the fulcrums of the swinging movement of the yoke 23 A.
Similarly, in the longitudinal-direction outer portions of the penetration holes 69 , 69 of the yoke 23 B as well, there are formed bow-shaped-plate-like projection portions 71 , 71 projecting toward the upper valve body 61 of the cylinder 31 , that is the opposing member of the yoke 23 B, while the projection portions 71 , 71 provide the fulcrums of the swinging movement of the yoke 23 B.
Also, as shown in FIG. 1 , the projection portions 70 , 70 of the yoke 23 A are contacted with the fixing member 52 of the casing 50 and the projection portions 71 , 71 of the yoke 23 B are contacted with the upper valve body 61 , so that the yokes 23 A, 23 B can be respectively swung about their associated projection portions 70 , 70 , 71 , 71 .
In the above-structured toroidal-type continuously variable transmission, when the contact positions between the disks and the power rollers are changed, for example, a drive piston 33 situated on the left side in FIG. 2 is shifted downwardly in FIG. 2 , while a drive piston 33 on the right side is shifted upwardly in FIG. 2 . With the shifting movements of the drive pistons 33 , 33 , the trunnions 15 , 15 connected to the drive pistons 33 , 33 are shifted in the mutually opposite directions: that is, the left trunnion 15 is shifted upwardly in FIG. 2 , while the right trunnion 15 is shifted downwardly in FIG. 2 .
Due to this, as shown in FIG. 4A , the yoke 23 A is inclined in a direction, where the right side of the yoke 23 A in FIG. 4A is situated on the upper side, about the projection portions 70 , 70 contacted with the fixing member 52 of the casing 50 . Similarly, the yoke 23 B is also inclined in the same direction of the yoke 23 A about the projection portions 71 , 71 contacted with the upper valve body 61 of the cylinder 31 .
Also, in case where the left drive piston 33 shifts upwardly in FIG. 2 and the right drive piston 33 shifts downwardly in FIG. 2 , as shown in FIG. 4B , the yoke 23 A is inclined in a direction where the left side of the yoke 23 A in FIG. 4B is situated on the upper side; and, the yoke 23 B is also inclined in the same direction of the yoke 23 A.
And, due to the swinging movements of the yokes 23 A, 23 B, the shifting movements of the trunnions 15 , 15 supported by the yokes 23 A, 23 B can be synchronized with each other.
As described above, since the yokes 23 A, 23 B are swung about the bow-shaped-plate-like projection portions 70 , 70 , 71 , 71 contacted with the fixing member 52 of the casing 50 and upper valve body 61 , the swinging movements of the yokes 23 A, 23 B can be made smooth. This can synchronize the shifting movements of the trunnions 15 , 15 supported on the yokes 23 A, 23 B with each other stably, which in turn can stabilize the transmission performance of the toroidal-type continuously variable transmission.
Also, because the present structure can be obtained by forming the projection portions 70 , 70 , 71 , 71 in the yokes 23 A, 23 B, the manufacture of the yokes can be facilitated. Also, since there is eliminated the need for special provision of a pin or the like, the manufacturing cost of the yokes and thus the toroidal-type continuously variable transmission can be reduced.
And, because the clearance s are formed between the yokes 23 A, 23 B and spherical-shaped surface posts 64 , 68 , the yokes 23 A, 23 B can be moved by an amount corresponding to the clearance S. Thanks to this, even in case where the positions of the yokes 23 A, 23 B inside the casing 50 vary, or even in case where the positions of the contact portions between the peripheral surface 11 a of the power roller 11 and disks 2 , 3 vary according to the power rollers 11 due to variations in the assembling positions of the power rollers 11 with respect to the trunnions 15 , the yokes 23 A, 23 B are allowed to move in the horizontal direction, thereby being able to correct the variations in the positions Of the contact portions.
Therefore, loads applied to the respective power rollers 11 can be made substantially uniform, which makes it possible to prevent the durability of the power rollers 11 from lowering, thereby being able to extend the lives of the power rollers 11 .
Also, in order not to descend the durability of the power roller 11 , since it is not necessary to set the positions of the yokes 23 A, 23 B inside the casing 50 and the assembling positions of the power rollers 11 with respect to the trunnions 15 with high accuracy, the assembling operations of these parts can be facilitated.
Now, FIGS. 5 to 7 show a second embodiment of a toroidal-type continuously variable transmission according to the present invention. By the way, in the present embodiment, the composing elements thereof similar to those of the first embodiment are given the same designations and thus the description thereof is simplified here.
As shown in FIG. 5 , in the fixing member 52 of the casing 50 that is an opposing member to the yoke 23 A, there are formed bow-shaped-plate-like projection portions 72 , 72 which project toward the yoke 23 A; and, in the upper valve body 61 of the cylinder 31 that is an opposing member to the yoke 23 B, there are formed bow-shaped-plate-like projection portions 73 , 73 which project toward the yoke 23 B.
As shown in FIGS. 6A and 6B , the projection portions 72 , 72 of the fixing member 52 of the casing 50 are contacted with the middle portions A of the yoke 23 A that are situated between the two end portions of the yoke 23 A crossing each other in the width direction of the yoke 23 A; and, the projection portions 73 , 73 of the upper valve body 61 are contacted with the middle portions B of the yoke 23 B that are situated between the two end portions of the yoke 23 B crossing each other in the width direction of the yoke 23 B. Thus, the yokes 23 A, 23 B can be respectively swung about their associated projection portions 72 , 72 , 73 , 73 .
In the above-structured toroidal-type continuously variable transmission, as shown in FIG. 7A and FIG. 7B , when the contact positions between the disks and the power rollers are changed, the yoke 23 A contacted with the projection portions 72 , 72 formed in the fixing member 52 of the casing 50 is swung about these projection portions 72 , 72 . Similarly, the yoke 23 B contacted with the projection portions 73 , 73 formed in the upper valve body 61 of the cylinder 31 is also swung about these projection portions 73 , 73 . Therefore, in the present embodiment, there can be obtained similar effects to the first embodiment.
Now, FIGS. 8 to 11 show a third embodiment of a toroidal-type continuously variable transmission according to the present invention. By the way, in the present embodiment, the same composing elements thereof as the first embodiment are given the same designations and thus the description thereof is simplified here.
As shown in FIGS. 8 and 9 , in the fixing member 52 of the casing 50 , there are formed bow-shaped-plate-like recess portions 74 , 74 with which the leading end portions of the projection portions 70 , 70 of the yoke 23 A can be fitted respectively. In case where the leading end portions of the projection portions 70 , 70 of the yoke 23 A are respectively fitted with the recess portions 74 , 74 of the fixing member 52 of the casing 50 , the yoke 23 A is swingably supported by the recess portions 74 , 74 .
Also, in the upper valve body 61 of the cylinder 31 , there are formed bow-shaped-plate-like recess portions 75 , 75 with which the leading end portions of the projection portions 71 , 71 of the yoke 23 B can be fitted respectively. In case where the leading end portions of the projection portions 71 , 71 of the yoke 23 B are respectively fitted with the recess portions 75 , 75 of the upper valve body 61 , the yoke 23 B is swingably supported by the recess portions 75 , 75 .
That is, according to the present embodiment, as shown in FIGS. 8 end 9 , there are omitted the spherical-shaped surface posts 64 , 68 (see FIGS. 1 and 2 ) which are used to support the yokes 23 A, 23 B in a swingable manner. Therefore, as shown in FIG. 10 , in the yokes 23 A, 23 B, there are not formed penetration holes through which the spherical-shaped surface posts 64 , 68 are inserted.
In the above-structured toroidal-type continuously variable transmission, as shown in FIGS. 11A and 11B , when the contact positions between the disks and the power rollers are changed, the yoke 23 A is swung about the projection portions 70 , 70 that are fitted with the recess portions 74 , 74 formed in the fixing member 52 of the casing 50 . Similarly, the yoke 23 B is also swung about the projection portions 71 , 71 fitted with the recess portions 75 , 75 formed in the upper valve body 61 of the cylinder 31 .
Therefore, according to the present embodiment, not only there can be obtained similar effects to the first embodiment but also the swinging centers of the yokes 23 A, 23 B are always constant to thereby be able to stabilize the swinging movements of the yokes 23 A, 23 B.
Also, because there is eliminated the need for provision of spherical-shaped surface posts and pins which are used to support the yokes 23 A, 23 B in a swingable manner, there can be eliminated not only the operation to form holes in the yokes 23 A, 23 B for insertion of the spherical-shaped surface posts and pins but also the operation to assemble the pins to the yokes 23 A, 23 B, thereby being able to facilitate further the manufacture of the yokes 23 A, 23 B. And, since it is not necessary to use the spherical-shaped surface posts and pins, the number of parts can be reduced and thus the manufacturing cost of the toroidal-type continuously variable transmission can be reduced further.
Now, FIGS. 12 to 15 show a fourth embodiment of a toroidal-type continuously variable transmission according to the present invention. By the way, in the present embodiment, the similar composing elements thereof to the first embodiment are given the same designations and thus the description thereof is simplified here.
As shown in FIGS. 12 and 13 , in the fixing member 52 of the casing 50 , there formed integrally therewith bow-shaped-plate-like projection portions 76 , 76 which project toward the yoke 23 A. Also, in the upper valve body 61 of the cylinder 31 , there are formed bow-shaped-plate-like projection portions 77 , 77 which project toward the yoke 23 B.
Also, as shown in FIGS. 14A and 14B , in the middle portions of the longitudinal-direction two end portions of the yokes 23 A, 23 B, there are formed bow-shaped-plate-like recess portions 78 , 78 , 79 , 79 with which the leading end portions of the projection portions 76 , 76 , 77 , 77 can be fitted respectively.
In case where the leading end portions of the projection portions 76 , 76 , 77 , 77 are respectively fitted with the recess portions 78 , 78 , 79 , 79 , the yokes 23 A, 23 B are swingably supported by the projection portions 76 , 76 , 77 , 77 .
That is, according to the present embodiment, as shown in FIGS. 12 and 13 , there are not formed the spherical-shaped surface posts 64 , 68 (see FIGS. 1 and 2 ) which are used to support the yokes 23 A, 23 B in a swingable manner. Therefore, as shown in FIGS. 14A and 14B , in the yokes 23 A, 23 D, there are not formed penetration holes through which the spherical-shaped surface posts 64 , 66 are inserted.
In the above-structured toroidal-type continuously variable transmission, as shown in FIGS. 15A and 15B , when the contact positions between the disks and the power rollers are changed, the yoke 23 A is swung about the recess portions 78 , 78 fitted with the leading end portions of the projection portions 76 , 76 formed in the fixing member 52 of the casing 50 . Similarly, the yoke 23 B is also swung about the recess portions 78 , 78 fitted with the leading end portions of the projection portions 77 , 77 formed in the upper valve body 61 or the cylinder 31 .
Therefore, according to the present embodiment, not only there can be obtained similar effects to the first embodiment but also the swinging centers of the yokes 23 A, 23 B can be always kept constant to thereby be able to stabilize the swinging movements of the yokes 23 A, 23 B.
Also, since there is eliminated the need for provision of the spherical-shaped surface posts and pins which are used to support the yokes 23 A, 23 B in a swingable manner, there can be eliminated not only the operation to form holes through which the spherical-shaped surface posts and pins are inserted but also the operation to assemble the pins to the yokes 23 A, 23 B, which makes it possible to facilitate further the manufacture of the yokes 23 A, 23 B. Further, because it is not necessary to use the spherical-shaped surface posts and pins, the number of parts can be reduced and thus the manufacturing cost of the toroidal-type continuously variable transmission can be reduced further.
By the way, the present invention is not limited to the above-described embodiments but various modifications are possible without departing from the gist of the present invention.
For example, in the first and third embodiments, in the yokes 23 A, 23 B, there are formed the projection portions 70 , 70 , 71 , 71 integrally with them. However, the projection portions 70 , 70 , 71 , 71 may also be formed separately from the yokes 23 A, 23 B.
Similarly, in the second embodiment as well, the projection portions 72 , 72 of the fixing member 52 of the casing 50 and the projection portions 73 , 73 of the upper valve body 61 of the cylinder 31 may also be formed separately from the fixing member 52 of the casing 50 and the upper valve body 61 of the cylinder 31 .
Further, in the fourth embodiment as well, the projection portions 76 , 76 of the fixing member 52 of the casing 50 and the projection portions 77 , 77 of the upper valve body 61 of the cylinder 31 may also be formed separately from the fixing member 52 of the casing 50 and the upper valve body 61 of the cylinder 31 .
Also, in the first and third embodiments, the projection portions 70 , 71 of the yokes 23 A, 23 B are formed in a bow-shaped-plate-like shape. However, the shape of the projection portions 70 , 71 is not limited to this but, for example, they may have a shape the leading end portion of which is rounded like a semi-spherical shape or a substantially triangular shape. This applies similarly to the projection portions 72 , 73 in the second embodiment as well as to the projection portions 76 , 77 in the fourth embodiment.
By the way, in case where the leading end portions of the projection portions 70 , 71 , 72 , 73 , 76 , 77 are rounded, the swinging movements of the yokes 23 A, 23 B can be made further smoother.
Also, in the above-mentioned respective embodiments, as the opposing members to the yokes, there are used the fixing member 52 of the casing 50 and the upper valve body 61 of the cylinder 31 ; however, instead of them, the casing 50 may be used as the opposing member.
As has been described heretofore, according to the toroidal-type continuously variable transmission of the present invention, not only the manufacture of a yoke can be facilitated but also the manufacturing cost of the yoke and thus the toroidal-type continuously variable transmission can be reduced. | A toroidal-type continuously variable transmission has a casing; an input disk and an output disk rotatably supported concentrically with each other; a plurality of power rollers each held between the input and output disks; a plurality of trunnions disposed at position twisted with respect to a center axis; a drive device for shifting the trunnions in the axial directions or the pivot shafts; a pair of yokes for supporting the pivot shafts of each of the trunnions so as to be swung and shifted in the axial direction thereof, the yokes being swingable according to the shifting movement of the associated trunnion; and, a pair of opposing members each disposed to be opposed to the associated yoke, wherein the yokes each includes projection portion contacted with the associated opposing member, the projection portion being the fulcrum of the swinging movements of the yokes. | 5 |
FIELD OF THE INVENTION
[0001] This invention relates generally to swim wear and, more particularly, to swim wear and method which allows individuals to self decorate the swim wear to have a unique appearance.
BACKGROUND OF THE INVENTION
[0002] Children and adult swimsuits are available in a variety of styles. These styles may range from conservative and conventional looks for children looks to more exotic and risqué fashions for adults. Generally, each style swimsuit has a particular cut which fits differently on each person's body, depending on the person's overall physique. In many instances, a person will buy a swimsuit, after trying it on briefly in the store, because they are attracted to the particular style of the suit or the designs on the swim suit.
[0003] Unfortunately, unlike other types of clothing, most stores will not allow a swimsuit to be returned once it has been purchased. Thus, if a person changes his/her mind after purchase and does not like the look/appearance of the swimsuit, the person is generally stuck with the purchase. Further, it is usually not possible to alter the appearance of the swim suit.
[0004] A need therefore exists for a swim suit and method to overcome the above problems.
[0005] The present invention satisfies these needs and provides other, related advantages.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Embodiments of the disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0007] FIG. 1 is a perspective view of one embodiment of the present invention;
[0008] FIG. 2 is a perspective view of another embodiment of the present invention; and
[0009] FIG. 3 is a method of the present invention.
DETAILED DESCRIPTION
[0010] Referring to FIGS. 1 , one embodiment of a swimsuit of the present invention is shown. In the present embodiment, the swimsuit 10 is a bikini style swimsuit. However, this is shown as one embodiment and should not be seen in a limiting manner. The swimsuit 10 may be a one piece swimsuit, a male swimsuit, a children's swimsuit, or the like.
[0011] In the embodiment shown in FIG. 1 , the swimsuit 10 is provided in the form of a bikini having a top 20 and a bottom 22 . The top 20 may be provided in various styles such as a triangular cup style, a bando style, or the like. The top 20 generally includes a means for securing the top 20 to the wearer. In the embodiment shown in FIG. 1 , the top 20 includes a string 23 for securing the top 20 around a torso and or neck of the wearer.
[0012] The bottom 22 may have front 24 and rear 25 ( FIG. 2 ) panels. An upper, outer ends of the front 24 and rear 25 panels of the bikini bottom may be attached together to allow the bottom 22 to be worn by the wearer.
[0013] The swimsuit 10 may be of a solid print. If the swimsuit 10 is a solid print, a lighter color print is generally used. Alternatively, the swimsuit 10 may have one or more designs. FIG. 2 shows that the bottom 22 may have a plurality of symbols 26 formed thereon. The symbols 26 may be different shapes and or sizes or the symbols 26 may all be the same shape and or size. The symbols 26 may be stars, flowers, geometric shapes, and the like. The listing of the above is given as an example and should not be seen in a limiting manner.
[0014] The symbols 26 may be pre-printed on the swimsuit 10 . However, in the preferred embodiment, the swimsuit may come with a plurality of decals. The decals may be different types of symbols 26 as described above. The decals may then be arranged on the swimsuit 10 and permanently attached thereto.
[0015] The swimsuit 10 may come with a plurality of writing instruments 27 . In accordance with one embodiment, the writing instruments 27 may come in a plurality of different colors. The writing instruments 27 may further be permanent markers. The writing instruments 27 may allow individuals to decorate the swimsuit 10 by drawing on the swimsuit. The individual may color in the symbols 26 , draw a picture on the swimsuit 10 or the like. After decorating the swimsuit 10 , the swimsuit 10 is allowed to dry for a predetermined amount of time so that the ink from the writing instruments is allowed to set in the fabric of the swimsuit 10 . Thus, the decorations drawn on the swimsuit 10 are permanent.
[0016] Referring to FIG. 3 , in operation, a person would buy the swimsuit 10 . The swimsuit 10 would come with writing instruments 27 . The swimsuit 10 may further come with a plurality of decals. The decals may be different types of symbols 26 as described above. The decals may then be arranged on the swimsuit 10 and permanently attached thereto.
[0017] An individual may use the writing instruments 27 to decorate the swimsuit 10 by drawing on the swimsuit. The individual may color in the symbols 26 , draw a picture on the swimsuit 10 or the like. After decorating the swimsuit 10 , the swimsuit 10 is allowed to dry for a predetermined amount of time so that the ink from the writing instruments is allowed to set in the fabric of the swimsuit 10 . Thus, the decorations drawn on the swimsuit 10 are permanent.
[0018] While embodiments of the disclosure have been described in terms of various specific embodiments, those skilled in the art will recognize that the embodiments of the disclosure can be practiced with modifications within the spirit and scope of the claims. | The present Invention is a method of coloring in decals and symbols that are pre-printed on swim suit with permanent non toxic colored markers provided to the user for coloring. | 3 |
BACKGROUND OF THE INVENTION
The present invention relates to a self-propelling machine for processing bituminous or concrete pavement material. The self-propelling machine may be a road finisher.
Road finishers are known e.g. from the following publications: DE 20 2007 003 326 U1, DE 20 2004 016 489 U1, DE 10 2004 002 658 A1, DE 299 23 118 U1, DE 299 20 556 U1, DE 299 15 875 U1, DE 296 12 035 U1, DE 296 12 034 U1 or DE 196 34 503 B4. Such road finishers can be driven by a wheel-type running gear, as described in DE 299 20 556 U1, or by a tracked running gear, as described in DE 299 23 118 U1. They are normally provided with a material bunker for accommodating the pavement mix which will form the road surface. With the aid of conveying means, e.g. scraper belts, the pavement mix is conveyed from the material bunker to the area of the road finisher located at the rear when seen in the direction of travel. In this rear area, the pavement mix supplied is distributed across the whole laying width, normally by means of a lateral distributor, e.g. an auger. Finally, the road finisher also carries a so-called screed, which is arranged behind the lateral distributor when seen in the direction of travel. It is used for smoothing and compacting the paving material applied, and, to this end, it may be provided with tampers, vibrating screed plates and/or pressure bars, by way of example.
Road finishers are driven by means of an engine, which is normally an internal combustion engine. In most cases, diesel engines are used. In addition to the driving power, the engine also provides power for operating a generator by means of which current is generated for operating a large number of components of the finisher. The current can, for example, be used for operating the lighting, the control, pumps for hydraulic components and, in particular, electric heating units. Such heating units are normally provided at all the components which come into contact with the pavement mix so as to prevent the latter from cooling down and solidifying on the components of the road finisher. Electric heating elements are especially provided on the screed, since this is the location of the road finisher where the strongest decrease in the temperature of the pavement mix has already occurred.
Due to its weight and the large number of driven components, and also due to the necessity of operating the heating elements, the amount of fuel consumed by a road finisher is comparatively large. In view of the rising energy prices, there is a significant rise in the contribution of the energy costs to the total operational costs of a road finisher. A 10 to 20% reduction of the amount of fuel consumed would already save, per year, several thousand liters of the fuel required for operating a road finisher. This would not only be beneficial to the environment but it would also reduce the operational costs of a road finisher to a significant extent.
BRIEF SUMMARY OF THE INVENTION
It is therefore the object of the present invention to reduce the amount of fuel consumed by a road finisher with the aid of means having the simplest possible structural design.
According to the present invention, this object is achieved by a self-propelling machine, e.g. a road finisher for processing bituminous or concrete pavement material including an internal combustion engine as a primary drive source, a controller for the engine, the controller receiving control signals, at least one pump drive unit, hydraulic-motor drive unit or hydrostatic drive unit for functional and operational components of the machine, and at least one hydraulic circuit comprising a hydraulic medium reservoir. Advantageous further developments of the invention are also disclosed below.
According to the present invention, the controller of the road finisher is configured for automatically causing starting and/or stopping of the engine in response to receipt of at least one specific control signal. According to the present invention, the controller of the road finisher is thus provided with an automatic start device, an automatic stop device or even an automatic start/stop device. This allows the engine to be stopped when specific operating conditions of the road finisher occur and/or it allows the engine to be restarted when other specific operating conditions occur. The fact that the engine is stopped during specific operating phases leads to a substantial reduction in the overall amount of fuel consumed. The automatic starting and/or stopping of the engine offers two additional advantages in comparison with manual starting or stopping: on the one hand, the operating phases allowing a deactivation of the engine are utilized in the best possible manner for accomplishing also a maximum reduction in the amount of fuel consumed. On the other hand, it is not necessary that the operator of the road finisher constantly checks the operating conditions allowing a deactivation of the engine. It follows that the handling of the road finisher will not be impaired in comparison with conventional road finishers.
According to a preferred embodiment, the road finisher is provided with a pushbutton for generating a start-control signal and a stop-control signal, so as to allow the road finisher to be operated in a conventional way. In addition, it is provided with at least one sensor for generating a control signal. This allows an automatic recognition of specific operating conditions of the road finisher, and the subsequent automatic starting and/or stopping of the engine. It is not necessary that the sensor itself is directly configured for generating a control signal, but it may also be configured such that it only transmits a measured variable to an evaluation circuit or an evaluation logic unit, which, in turn, generates the control signal for the engine controller.
It will be expedient when the sensor is a temperature sensor. This means that, depending on the temperature of specific components of the road finisher, the engine can be started and/or stopped. This is of interest especially for operating conditions in which the engine power is used exclusively or almost exclusively for the purpose of heating specific components of the road finisher. When it is recognized in such an operating condition that further heating is not necessary, the engine can be stopped according to the present invention. It is thus possible to save a substantial amount of fuel in comparison with the conventional deactivation of only the heating elements and the continued operation of the engine at the idling speed.
Such a temperature sensor may in particular be configured for measuring the temperature of a screed of the road finisher, or of a part of said screed (e.g. a basic screed, an extendible screed, etc.). Most of the heating power of the road finisher is normally required for the screed. It is, however, not necessary to heat the screed continuously, but heating is only required if the screed temperature dropped below a predetermined threshold. In conventional road finishers only the heating elements were deactivated, whereas the diesel engine continued to operate, as soon as a higher temperature threshold was exceeded. Making use of the present invention, it is now possible that the temperature sensor of the screed transmits a control signal (where appropriate, via a suitable evaluation circuit), in response to receipt of which the controller will cause a deactivation of the engine. Only when the temperature of the screed drops below a predetermined threshold, the engine will automatically be restarted so as to drive the generator and provide thus the electric power for operating the electric heating elements.
According to one variant of the present invention, a timer is provided for generating a control signal for the engine controller. Making use of this timer, it is possible to automatically start and/or stop the road finisher when predetermined time intervals have expired after specific events.
According to an extremely advantageous variant of the present invention, the road finisher comprises a localization and/or navigation system. This localization and/or navigation system can improve the operation of the road finisher in many ways. When the localization measurement is carried out with adequate precision, said localization and/or navigation system may perhaps allow a fully automatic operation of the road finisher.
According to a preferred embodiment, the localization and/or navigation system is so conceived that it is infrared-transmitter-, radio- or satellite-based. All these variants allow a precise, wireless localization and navigation of the road finisher.
It will be particularly advantageous when the localization and/or navigation system is configured for generating a control signal for the controller. In this way, the localization and/or navigation system of the road finisher according to the present invention will not only be able to allow localization and orientation of the road finisher, but it will also be able to cause, through the controller, starting and/or stopping of the engine, when specific operating conditions and ambient conditions exist.
The localization and/or navigation system may, for example, communicate with means for ascertaining the current distance to and/or an expected time of arrival of some other road works vehicle. This other road works vehicle may e.g. be a truck delivering pavement mix which is to be fed to the road finisher. When the road finisher and the other road works vehicle are each provided with a suitable, compatible localization and/or navigation system, the controller of the road finisher will be able to query the current position of the other road works vehicle and calculate from the current distance the expected time of arrival of the approaching road works vehicle. When the engine controller is additionally provided with a clock or a timer, the engine of the road finisher can be started at a suitable moment, so that the screed and the other heated components of the road finisher will have reached the necessary operating temperature precisely when the other road works vehicle arrives. Prior to the heating phase, which is rendered as short as possible in this way, the engine of the road finisher according to the present invention can remain deactivated and substantial amounts of fuel can be saved in this way. Against this background, it will be expedient when the means for ascertaining the current distance to and/or an expected time of arrival of some other road works vehicle is configured for generating a control signal for the engine controller.
According to a preferred embodiment, the road finisher according to the present invention comprises a starting device for starting the engine in response to receipt of a respective control signal, said starting device being e.g. a starter motor, an engine-generator unit (whereby it will no longer be necessary to use a starter motor and a dynamo), a hydraulic starter making use of an accumulator or the like. In this way, the engine controller can start the engine automatically by transmitting the control signal to the starting device.
In this respect, it will be advantageous when a battery is additionally provided so as to be able to supply the starting device with energy also in the deactivated condition of the engine.
BRIEF DESCRIPTION OF THE DRAWING
In the following, an advantageous embodiment of the present invention will be described in more detail making reference to a drawing.
FIG. 1 shows a side view of a road finisher 1 according to the present invention as an example of a self-propelling machine according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
The road finisher 1 is provided with a chassis 2 having arranged thereon the control station 3 of the road finisher 1 . The road finisher 1 is movable by means of a running gear 4 , which is in the present case a wheel-type running gear 4 with wheels 5 . The running gear 4 is driven by means of a diesel engine 6 mounted on the chassis 2 and connected to a generator (not shown) so as to produce electric voltage.
The road finisher 1 additionally comprises a material bunker 7 for accommodating pavement mix, a conveying device (not shown) for conveying the pavement mix from the material bunker 7 , underneath the control station 3 , to the rear area of the road finisher, and a lateral distributor 8 , e.g. an auger, for distributing the pavement mix across the whole laying width in a direction at right angles to the direction of travel of the road finisher 1 . The screed 10 is supported on the road finisher 1 on a beam 9 which is adapted to be hydraulically pivoted up and down. It is used for compacting and smoothing the pavement mix discharged.
The road finisher 1 is additionally provided with at least one pump, hydraulic-motor or hydrostatic drive unit (not shown) for functional and operational components of the machine, and with at least one hydraulic circuit comprising a hydraulic medium reservoir.
The road finisher 1 additionally comprises a controller 11 which is configured for automatically causing starting and/or stopping of the engine 6 in response to receipt of at least one control signal. For starting the engine 6 , a starting device 12 , e.g. a starter motor, is provided, which is supplied with electric power via a an energy store, e.g. a battery 13 , independently of the operating condition of the diesel engine 6 and of the generator (not shown). The energy store, e.g. the battery 13 , can be charged when the generator is in operation.
Alternatively, the starting device 12 could be a motor-generator unit or a hydraulic starter comprising an accumulator as an energy store.
The controller 11 communicates with a temperature sensor 14 on the screed 10 in a wireless or wire-bound fashion. The temperature sensor 14 measures the temperature of the screed 10 . It can transmit a control signal to the controller 11 , if the temperature of the screed should exceed or fall below predetermined temperature thresholds.
The engine controller 11 is additionally provided with a localization and navigation system 15 . This localization and navigation system 15 is satellite-based (e.g. via GPS) and serves to identify the current position of the road finisher 1 . In the present case, it is also configured for communication with a compatible localization and navigation system of some other road works vehicle, e.g. a truck for delivering the pavement mix. The localization and navigation system 15 of the road finisher 1 is able to ascertain the current position of and the distance to the other road works vehicle and, by means of suitable processes, it is able to calculate the expected time of arrival of the other road works vehicle at the road finisher 1 . This calculation of the expected time of arrival can be executed in the controller 11 .
Operation of the road finisher 1 according to the present invention can take place as described in the following.
In a stand-by mode, the road finisher 1 is stationary at some site and waits for the pavement mix and/or for a signal that the laying operation should begin. In order to be able to start the laying operation as soon as possible, all the heated parts, in particular the screed 10 , are maintained at the temperature required for pavement laying by operating the heating elements provided for this purpose. As soon as the temperature sensor 14 provided on the screed 10 (or a further temperature sensor provided on other heated components of the road finisher 1 ) recognizes that a predetermined temperature threshold, which makes further heating superfluous, has been exceeded, the sensor 14 will report this through a respective control signal to the engine controller 11 . The engine controller 11 will then take care that the diesel engine 6 is stopped, since the power of the latter is neither required as a driving power for propelling the road finisher nor is it required for operating the heating elements.
The temperature of the screed 10 will then decrease slowly. When the temperature sensor 14 recognizes that the temperature has fallen below a predetermined threshold, it will report this to the engine controller 11 through another control signal. The engine controller 11 will then cause automatic starting of the engine 6 by means of the starting device 12 , e.g. the starter motor, so that the engine 6 can operate the generator and provide thus the electric power for the heating elements. The automatic starting and stopping of the engine 6 during the cooling phases of the screed 10 will save a substantial amount of fuel.
In another situation, the road finisher 1 waits for the arrival of a truck carrying the pavement mix. In this condition, the diesel engine 6 remains deactivated so that no fuel will be consumed. The laying operation should, however, begin as immediately as possible after delivery of the pavement mix.
By means of the localization and navigation system 15 , the road finisher 1 is able to identify the current position of the approaching truck so as to determine therefrom the expected time of arrival of the pavement mix. The controller 11 has stored therein information indicating how much time will be necessary for heating the screed 10 to its operating temperature. This enables the controller 11 to start the diesel engine 6 at a suitable moment so that the necessary operating temperature will precisely be reached when the truck arrives. Unnecessarily long heating phases are avoided in this way, and it is also possible to start the laying operation immediately after receipt of the pavement mix.
Taking as a basis the embodiment shown, the road finisher 1 according to the present invention can be modified in many ways. For example, additional sensors may be provided for monitoring specific operating conditions of various components of the road finisher 1 , which make it appear advisable to start and/or stop the engine 6 . | A self-propelling machine for processing bituminous or concrete pavement material, in particular a road finisher or a feeder. The machine comprises an internal combustion engine as a primary drive source, a controller for the engine, said controller receiving control signals, at least one additional drive unit for functional and operational components of the machine as well as at least one hydraulic circuit comprising a hydraulic medium reservoir. The controller is configured for automatically causing starting and/or stopping of the engine in response to receipt of at least one specific control signal. | 4 |
FIELD OF THE INVENTION
The present invention is related to fiber optic cables and more particularly to racks for cable routing management at interconnection sites.
BACKGROUND OF THE INVENTION
In premise wiring, pluralities of fiber optic cables are interconnected to others at interconnection sites where the connectors for individual optical fiber interconnection are provided in pluralities of enclosures in an optical interconnection bay of an office premises. Cables extending to the interconnection site from outside the office premises, and the cables extending from various locations within the premises, must be arranged for cable ends to extend to appropriate ones of the plurality of enclosures for interconnection to associated cables. Additionally, lengths of cables commonly are required to interconnect between enclosures at the site. All of the great plurality of cables must be routed in an orderly manner that permits easy installation and also in a manner that maintains the cables accessible for later servicing and repair. Further, the cables must be routed around bends in a manner preventing sharp bending of the cables and damaging the individual fragile optical fibers or undesirably attenuating the optical signals during transmission.
SUMMARY OF THE INVENTION
The present invention is a rack system adapted to route pluralities of fiber optic cables to selected ones of many enclosures having connectors for optical fiber interconnection. An open framework provides for holding enclosures of various types and sizes at known positions in columnar fashion, with narrow vertical end frame members defining ends of the framework and if used alone define an enclosure stack therebetween. Usually, one or more wider vertical intermediate frame members are positioned between and spaced from the end frame members to define openings for stacks of enclosures. The fiber optic cables are generally routed vertically along both types of frame members. Several types of brackets are provided all extending forwardly from a vertical frame member, preferably a common distance at least as far forwardly as ends of interconnection enclosures affixed to the framework.
Orthogonal brackets are regularly spaced vertically along at least the end frame members and affixed thereto, and enable conventional securing thereto of vertically oriented cable bundles such as by cable ties. The orthogonal brackets may further define at forwardmost ends thereof mounting flanges defining fastener sites providing for mounting of rack cover panels thereto upon completion of cable routing, in a manner permitting easy cover removal for cable servicing and repair. Optional relay brackets each form a continuous oval cable support surface and are fixedly mounted on intermediate ones of the vertical frame members between enclosure stacks, enabling take-up storage of lengths of cable looped therearound if desired, and also may further define at forwardmost ends thereof mounting flanges for enabling rack cover panel mounting.
Radius limiting brackets are mountable to, and removable from, end frame members and intermediate frame members at selected fastening sites to provide support for directing end portions of cables into a horizontal orientation for entry into associated enclosures for fiber interconnection. One type of radius limiting bracket includes an arcuate cable support surface extending for less than a quarter-turn for supporting a cable about a 90° turn, and preferably two variations are provided to permit radius limiting support for cables descending from above or for cables ascending from below to be directed to the left or to the right, as desired. A second type of radius limiting bracket may be provided having two arcuate cable support surfaces to provide for a 180° cable turn, such as for directing cables from one enclosure to another adjacent thereto, with the two support surfaces spaced to complement the distance between enclosure levels and may be joined therebetween by a planar surface tangential to the two arcuate support surfaces.
Columnar arrays of fastening sites are provided on the vertical frame members allowing for positioning of the radius limiting brackets essentially at any desired vertical location adjacent the enclosure columns, with one such fastening site array on each end frame member and two such arrays provided along side edges of each of the wider intermediate frame members outwardly of the relay brackets. The frame members may provide opposed spaced apart mounting surfaces enabling brackets to be mounted thereto for cable management along both mounting surfaces, where one thereof may be dedicated to cables from interior premise locations and the other to exterior premise locations.
It is an objective of the present invention to provide a system for securing and appropriately routing within an optical interconnection bay, end portions of fiber optic cables extending from the bay to other locations within an office premises or outwardly from the office premises.
It is another objective for the system to be modular to enable selectively positioning and routing the cables to interconnection enclosures.
It is a further objective for the system to facilitate access to the cables for servicing.
It is also an objective for the system to provide radius limiting brackets that are easily assembled to the framework at selected locations to program the rack as desired, and that are easily removed and relocated if desired.
An embodiment of the present invention will now be described by way of example with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a cable management rack containing the present invention, with an end frame member and an intermediate frame member having therebetween two representative interconnection enclosures, and a pair of representative cable bundles secured to brackets of the end frame member and routed around respective radius limiting brackets, and with a representative rack cover panel exploded from the end frame member;
FIGS. 2 and 3 are isometric views of one type of radius limiter bracket and a rack portion illustrating its use with representative cables and also showing an orthogonal bracket all mounted to an end frame member; and
FIGS. 4 and 5 are isometric views another type of radius limiter bracket and a rack portion illustrating its use with representative cables.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates the cable management rack 10 of the present invention. Framework 12 of the rack includes one of a pair of end frame members 14 and one of an indefinite number of intermediate frame members 16 utilized between the end frame members. A removable rack cover member 18 is shown exploded from end frame member 14 and is fastenable thereto upon routing and fastening of all cables to rack 10. Shown between end frame member 14 and intermediate frame member 16 is a vertical space defined by a pair of vertical rails 140,142 beside both frame members 14,16 and upper and lower horizontal crosspieces 144, comprising a conventional enclosure rack portion complying with Electronics Industry Association standards. The enclosure rack portion contains a plurality of enclosure sites 20 at which are mounted interconnection enclosures 22 to form an enclosure stack, with two such enclosures shown with their front panels removed.
Representative fiber optic cables 24 are shown extending upwardly from an opening through the flooring and ascending along end frame member 14 forwardly of mounting surface 26 thereof. End portions 28 of cables 24 extend through cable exits 30 of enclosures 22, for ends of optical fibers thereof to be interconnected to other associated fibers within the enclosures. Other cables may similarly be routed from above rack 10 to descend along end frame member 14 or along mounting surface 32 intermediate frame member 16 to be similarly routed to interconnection sites within enclosures such as enclosures 22. End frame member 14 includes a columnar array of fastening sites 34 adjacent the inner edge 36 thereof and thus proximate cable exits 30 of the enclosures 22 of the enclosure stack. Intermediate frame member 16 includes columnar arrays of fastening sites 34 adjacent both edges 38 thereof, also proximate cable exits of the enclosures.
First or orthogonal brackets 40 are seen in FIGS. 1, 3 and 5 affixed to mounting surface 26 of end frame member 14 along outer edge 42 thereof at regularly spaced intervals, and cables 24 are seen to be secured to several thereof by conventional cable ties 44 secured to brackets 40 through apertures 46 through body sections 48 thereof joined to mounting sections 50 and extending orthogonally from mounting surface 26 of end frame member 14. At ends of body sections 48 are seen mounting flanges 52 extending parallel to frame mounting surface 26 and having apertures 54 therethrough, with apertures 54 cooperable with fasteners 56 preferably self-retainably secured to rack cover panel 18 enabling the rack cover panel to be mounted to the rack to enclose the routed cables. Mounting flanges 52 serve as cable retainer sections assuring the maintenance of the cables proximate the framework of rack 10 prior to securing the rack cover panels to the rack.
Second or radius limiter brackets 70,70A are seen mounted to end frame member 14 and to intermediate frame member 16. Each radius limiter bracket 70,70A includes an arcuate cable support surface 72 oriented perpendicular to the mounting surfaces 26,32 of frame members 14,16. Each arcuate cable support surface 72 has a selected radius large enough to protect an optical fiber extending about a bend of like radius, such that the fibers within a fiber optic cable 24 are protected as the cables are routed about the arcuate cable support surface to change direction such as from a vertical to a horizontal orientation, or a bend angle of 90°. Cable retainer sections 74 are also provided to assure the maintenance of the cables proximate the framework of rack 10 prior to securing the rack cover panels to the rack.
Referring to FIG. 2, radius limiter bracket 70 includes a mounting section 76 oriented parallel to the mounting surfaces 26,32 of frame members 14,16. Mounting section 76 is seen to provide two fastener locations 78 comprising apertures, with fasteners 80 preferably self-retainably mounted thereat. It can be seen that the pair of fastener locations corresponds to the pair of corresponding fastener locations 82 of each fastening site 34 defined in the single columnar array on end frame member 14 and the two columnar arrays on intermediate frame member 16. Preferably radius limiter brackets are of a "left-handed" type and a "right-handed" type, with the left-handed type 70 being displayed in FIG. 2 and the right-handed type 70A in FIG. 3; the two types may be utilized as desired to direct descending cables to the left or right or to direct ascending cables (such as cables 24 in FIGS. 1 and 3) to the left or right. An appropriate bracket can be selected once it has been determined that the cables will either be descending or ascending along a particular columnar array of fastening sites, and the cables thus being associated with an enclosure stack to the left or to the right; the bracket should be positioned such that the leading edge of the arcuate cable support surface precedes the nearest portion of the enclosure's cable exit, with the cables continuing on a gentle arc beyond the support surface and into the cable exit and not urged against the leading edge.
With reference to FIG. 3, radius limiter bracket 70A is shown utilized to support fiber optic cables 24 about a bend of 90° while maintaining a desired minimum radius to the bend of the cables for protecting the optical fibers therewithin against damage or undesirable signal transmission attenuation from sharp bends. The arcuate cable support surface 72 may extend an arcuate distance of 90° or it may be somewhat less than that and still easily fulfill the desired purpose without protruding extensively in a horizontal direction, thus enabling a slight reduction in the horizontal dimension of the cable management rack 10 while allowing sufficient cable management access forwardly of mounting surfaces 26,32 of the frame members. Also seen is a flange 146 that enables fastening of frame member 14 to rail 140 of the enclosure rack portion of FIG. 1, while the enclosures would be fastened to rail 142 thereof using brackets of the enclosures (not shown).
In FIG. 4 is shown another type of radius limiter bracket 90 having a pair of arcuate cable support surfaces 92,94 with a planar bracket section 96 extending therebetween and that is tangential thereto. Similarly to radius limiter bracket 70, bracket 90 includes a mounting section 98 having fastener locations for two fasteners 100, and also preferably including a cable retaining section 102.
With reference to FIG. 5, radius limiter bracket 90 may be utilized when it is desired at a selected location on either an end frame member 14 or intermediate frame member 16 to provide for jumper cables 104 to extend from one enclosure 22 to an adjacent enclosure in the stack, thus requiring a cable or bundle thereof to extend about a bend of 180°, and each arcuate cable support surface 92,94 may be 90° or less.
With reference again to FIG. 1, another type of bracket 110 is seen mounted to mounting surface 32 of intermediate frame member 16 between the columnar arrays of fastening sites 34. Relay bracket 110 provides a continuous cable support surface 112 oval in shape, around which may be looped coils 114 of excess length of fiber optic cable 116 that is utilized to extend from stack to stack of the enclosures 22, such as for jumping or interconnecting selected connector sites of the enclosures. Semicylindrical cable support surfaces 118 at ends of the oval shape maintain a desired minimum radius for the optical fibers of cables 116. Relay bracket 110 is also seen to have mounting flanges 120 extending parallel to mounting surface 32 of intermediate frame member 16 and include apertures 122 enabling mounting thereto of rack cover panel members similar to rack cover panel 18 for enclosing the rack between the enclosure stacks. Also seen are cable retainer sections 124 at the ends of the oval.
Orthogonal brackets 40 and relay brackets 110 may be affixed to the frame members more or less permanently such as by screws or bolts or rivets (not shown) and may be made from rugged, durable material such as 14-gauge aluminum. Radius limiter brackets 70,90 may be made from rugged, durable material such as 14-gauge aluminum. Frame members 14,16 are preferably made from rugged, durable material such as 14-gauge aluminum while rack cover panels may be made from 16-gauge aluminum. Fasteners 56,80,100 may all be alike and may be of a type permitting easy and quick mounting with conventional tools, or manually, for permitting assembly in the field at an interconnection bay, and preferably also permit easy and quick unmounting, facilitating rack cover panel removal and also removal or relocation of the radius limiter brackets.
One type of fastener especially suitable for use with the present invention is a quarter turn one-piece fastener sold by The Hartwell Corporation of Placentia, Calif. under the product identification NYLATCH, disclosed in U.S. Pat. No. 3,964,364. Fastener 56,80,100 is self-retainably mounted to a fastener site of either a cover panel 18 or a radius limiter bracket 70,90 such that a locking portion 130 extends through an aperture thereof to be inserted through a corresponding aperture of either the orthogonal bracket 40 or a frame member 14,16. An accessible actuator section 132 is tool-actuatable to be rotated through a quarter turn from a first or unlocked state to a second or locked state, camming the legs 134 of the locking section apart and thus expanding the locking section 130 to lock behind the periphery of the aperture of the bracket 40 or frame member 14,16 and securing the cover panel or radius limiter bracket thereto. Thereafter, the actuator section 132 is again tool-actuatable from the second or locked state to the first or unlocked state to facilitate removal of the cover panel or the radius limiter bracket.
It is seen that the present invention can utilize any number of intermediate frame members and associated rack cover panels, to define a cable management rack of any desired size, providing for the interconnection of any number of stacked enclosures that may be mountable to an enclosure rack portion of framework 12 between the vertical frame members. It may also be desirable to modify the vertical frame members of the present invention to be fastened directly to horizontal crosspieces and to the enclosures. Variations in the particular shapes of the brackets may be devised, or in the manner of fastening them to the framework. Other variations and modifications may occur that are within the spirit of the invention and the scope of the claims. | A cable management rack (10) for supporting and routing pluralities of fiber optic cables (24) to and from optical interconnection sites of stacks of interconnection enclosures (22). First brackets (40) along end frame members (14) enable securing of the cables routed vertically, and also support removable rack cover panels (18). Second brackets (70,70A, 90) include arcuate cable support surfaces (72) for routing selected cables 90° (or 180°) about bends having radiuses great enough to protect the optical fibers of the cables. The second brackets (70,70A, 90) are removably affixable to the end frame members (14) or to intermediate frame members (16) at any location along a columnar array of fastening sites (34) beside the enclosure stacks, to correspond to any desired location of a cable bend, with the rack thus being modular. Relay brackets (110) provide for excess cable take-up. | 7 |
This application is a division of application Ser. No. 200,676, filed May 31, 1988, U.S. Pat. No. 5,002,851.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to selected methylol-substituted trihydroxybenzophenones as novel compositions of matter. The present invention relates to selected phenolic resins containing at least one unit which is a condensation product of the selected methylol-substituted trihydroxbenzophenones and selected phenolic monomers. Furthermore, the present invention relates to light-sensitive compositions useful as positive-working photoresist compositions, particularly, those containing these phenolic resins and o-quinonediazide photosensitizers. Still further, the present invention also relates to substrates coated with these light-sensitive compositions as well as the process of coating, imaging and developing these light-sensitive mixtures on these substrates.
2. Description of Related Art
Photoresist compositions are used in microlithographic processes for making miniaturized electronic components such as in the fabrication of integrated circuits and printed wiring board circuitry. Generally, in these processes, a thin coating or film of a photoresist composition is first applied to a substrate material, such as silicon wafers used for making integrated circuits or aluminum or copper plates of printed wiring boards. The coated substrate is then baked to evaporate any solvent in the photoresist composition and to fix the coating onto the substrate. The baked coated surface of the substrate is next subjected to an image-wise exposure of radiation. This radiation exposure causes a chemical transformation in the exposed areas of the coated surface. Visible light, ultraviolet (UV) light, electron beam and X-ray radiant energy are radiation types commonly used today in microlithographic processes. After this image-wise exposure, the coated substrate is treated with a developer solution to dissolve and remove either the radiation-exposed or the unexposed areas of the coated surface of the substrate.
There are two types of photoresist compositions--negative-working and positive-working. When negative-working photoresist compositions are exposed image-wise to radiation, the areas of the resist composition exposed to the radiation become less soluble to a developer solution (e.g. a cross-linking reaction occurs) while the unexposed areas of the photoresist coating remain relatively soluble to a developing solution. Thus, treatment of an exposed negative-working resist with a developer solution causes removal of the non-exposed areas of the resist coating and the creation of a negative image in the photoresist coating, and thereby uncovering a desired portion of the underlying substrate surface on which the photoresist composition was deposited. On the other hand, when positive-working photoresist compositions are exposed image-wise to radiation, those areas of the resist composition exposed to the radiation become more soluble to the developer solution (e.g. a rearrangement reaction occurs) while those areas not exposed remain relatively insoluble to the developer solution. Thus, treatment of an exposed positive-working resist with the developer solution causes removal of the exposed areas of the resist coating and the creation of a positive image in the photoresist coating. Again, a desired portion of the underlying substrate surface is uncovered.
After this development operation, the now partially unprotected substrate may be treated with a substrate-etchant solution or plasma gases and the like. This etchant solution or plasma gases etch the portion of the substrate where the photoresist coating was removed during development. The areas of the substrate where the photoresist coating still remains are protected and, thus, an etched pattern is created in the substrate material which corresponds to the photomask used for the image-wise exposure of the radiation. Later, the remaining areas of the photoresist coating may be removed during a stripping operation, leaving a clean etched substrate surface. In some instances, it is desirable to heat treat the remaining resist layer after the development step and before the etching step to increase its adhesion to the underlying substrate and its resistance to etching solutions.
Positive-working photoresist compositions are currently favored over negative-working resists because the former generally have better resolution capabilities and pattern transfer characteristics.
Photoresist resolution is defined as the smallest feature which the resist composition can transfer from the photomask to the substrate with a high degree of image edge acuity after exposure and development. In many manufacturing applications today, resist resolution on the order of one micron or less are necessary.
In addition, it is generally desirable that the developed photoresist wall profiles be near vertical relative to the substrate. Such demarcations between developed and undeveloped areas of the resist coating translate into accurate pattern transfer of the mask image onto the substrate.
One drawback with positive-working photoresists known heretofore is their limited resistance to thermal image deformation. This limitation is becoming an increasing problem because modern processing techniques in semiconductor manufacture (e.g. plasma etching, ion bombardment) require photoresist images which have higher image deformation temperatures (e.g. 150° C.-200° C.) Past efforts to increase thermal stability (e.g. increased molecular weight of the resin) generally caused significant decrease in other desirable properties (e.g. decreased photospeed, diminished adhesion, or reduced contrast, poorer developer dissolution rates), or combinations thereof].
Accordingly, there is a need for improved positive-working photoresist formulations which produce images that are resistant to thermal deformation at temperatures of about 150° to 200° C. while maintaining the other desired properties (e.g. developer dissolution rates) at suitable levels. The present invention is believed to be an answer to that need.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to selected methylol-substituted trihydroxybenzophenones of the formula (I): ##STR3##
Moreover the present invention is directed to a phenolic novolak resin comprising at least one unit of formula (II): ##STR4## wherein R and R 1 are individually selected from hydrogen, a lower alkyl group having 1 to 4 carbon atoms and a lower alkoxy having 1 to 4 carbon atoms and said unit or units of formula (II) are made by condensing the methylol-substituted trihydroxybenzophenone of formula (I) with selected phenolic monomer units of formula (III): ##STR5## wherein R and R 1 are defined above.
Moreover, the present invention is directed to a light-sensitive composition useful as a positive photoresist comprising an admixture of o-quinonediazide compound and binder resin comprising at least one unit of the formula (II), above; the amount of said o-quinonediazide compound or compounds being about 5% to about 40% by weight and the amount of said binder resin being about 60% to 95% by weight, based on the total solid content of said light-sensitive composition.
Still further, the present invention also encompasses the process of coating substrates with these light-sensitive compositions and then imaging and developing these coated substrates.
Also further, the present invention encompasses said coated substrates (both before and after imaging) as novel articles of manufacture.
DETAILED DESCRIPTION
The selected methylol-substituted trihydroxybenzophenones of formula (I) are made by reacting the corresponding trihydroxybenzophenone with formaldehyde under alkaline pH conditions. This reaction is illustrated below in reaction equation (A) wherein the trihydroxybenzophenone is 2,3,4-trihydroxybenzophenone and the alkali employed is NaOH and 5-methylol-2,3,4-trihydroxybenzophenone is made: ##STR6## It should be noted that when 2,3,4-trihydroxybenzophenone is employed as the reactant, the reaction occurs almost completely at the 5-position of the trihydroxyphenyl ring. Other isomeric reactions are insignificant. The reason for the selectivity of this particular reaction is the relative electronic activation of the 5-position by the hydroxyl groups on the ring; however, the present invention is not to be limited to any particular reactants or process limitation for this particular type of reaction.
In making the class of compounds of the present invention, the precursors are preferably reacted at about a 1:1 mole ratio. The preferred reaction temperature is about 40°-50° C. for about 2.5 hours or less at atmospheric pressure. Excess reaction time may cause undesirable polymerization of the intended product. This reaction preferably occurs at an alkaline pH of greater than 7. The pH may be controlled by the addition of specific amounts of alkaline compounds (e.g. NaOH, KOH, Na 2 CO 3 and the like). The intended product may be recovered from the reaction mixture by mixing the reaction mixture with acidified water and thus precipitating the product in solid form.
The phenolic resins containing one or more units of formula (II) above are preferably made by reacting the methylol-substituted trihydroxybenzophenone of formula (I), above, and the selected phenolic monomers having units of formula (III) with formaldehyde under usual novolak-making conditions. Generally, this reaction occurs in the presence of an acid catalyst. Suitable acid catalysts include those commonly employed in acid condensation-type reactions such as HCl, H 3 PO 4 , H 2 SO 4 , oxalic acid, maleic acid, maleic anhydride and organic sulfonic acids (e.g. p-toluene sulfonic acid). The most preferred acid catalyst is oxalic acid. Generally, it is also preferred to carry out the condensation reaction of compounds of formulae (I) with (III) either simultaneously or after the novolak polymerization in the presence of an aqueous medium or an organic solvent. Suitable organic solvents include ethanol, tetrahydrofuran, cellosolve acetate, 1-methoxy-2-propanol and 2-ethoxy ethanol. Preferred solvents are water-soluble solvents such as ethanol, 1-methoxy-2-propanol and 2-ethoxy ethanol.
The mole ratio of the methylol-substituted trihydroxybenzophenone to the total of the other phenolic compounds (preferably, a combination of meta- and para-cresols) is generally from about 0.1:99.9 to 20:80; more preferably, about 5:95 to about 10:90.
The methylolated trihydroxybenzophenone of formula (I) predominantly reacts in the para-position on the phenolic molecules as illustrated in formula (III), above. For example, this trihydroxybenzophenone compound will predominantly react with phenol or ortho- or meta-cresol, but less favorably with para-substituted phenolic molecules. The thus prepared novolaks containing the units of formula (II), above, have showed greater dissolution rates in aqueous alkaline developers than corresponding novolaks prepared without these units. Furthermore, light-sensitive compositions prepared with novolaks containing these units of formula (II) also showed good thermal stability due to their higher molecular weight and high resolution images. It is also believed that the presence of the units of formula (II) in the novolak resin significantly reduce the degree of branching of the novolak and provide unhindered hydroxyl (OH) groups for improved solubility properties and chemical reactivity.
In making the present class of resins, the precursors, namely, the trihydroxybenzophenones of formula (I) and the phenolic monomers (most preferably, a mixture of meta- and para-cresols) are preferably placed in a reaction vessel with formaldehyde. The reaction mixture usually also contains an acid catalyst and solvent as noted above. The mixture is then preferably heated to a temperature in the range from about 60° C. to about 120° C., more preferably from about 65° C. to about 95° C., for both the novolak-forming condensation polymerization reaction and the separate phenolic resin-trihydroxybenzophenone condensation reaction to occur. If an aqueous medium is used instead of an organic solvent, the reaction temperature is usually maintained at reflux, e.g. about 95° C. to 110° C. The reaction time will depend on the specific reactants used and the ratio of formaldehyde to phenolic monomers. The mole ratio of formaldehyde to total phenolic moieties is generally less than about 1:1. Reaction times from 3 to 20 hours are generally suitable. Alternatively, the trihydroxybenzophenones of formula (I) may be first reacted to the phenolic monomers of formula (III) without the presence of formaldehyde. In such cases, the condensation product of formula (II) is made and such condensation products may then be reacted with formaldehyde along with other phenolic monomers to make the novolak resins of the present invention.
The most preferred methylol-substituted trihydroxybenzophenone is 5-methylol-2,3,4-trihydroxybenzophenone as shown above in formula (A). The most preferred phenolic monomers is a mixture of meta-cresol and para-cresol having a mole ratio ranging from about 70:30 to about 30:70, respectively.
Branched and unbranched novolak resins made from this mixture of meta- and para-cresols will thus include the following types of repeated phenolic units: (1) units of formula (II) above; (2) meta-cresol units of the formula (IV), (IVA) and (IVB): ##STR7## and para-cresol units of formula (V): ##STR8##
Regardless of the presence or absence of the further units of formulae (IV) and (V), the resins of the present invention preferably have a molecular weight of from about 500 to about 25,000, more preferably from about 750 to about 20,000. The preferred resins have from about 0.1% to about 30%, more preferably about 5% to 10% by moles of the units of formula (II).
The above-discussed resins of the present invention may be mixed with photoactive compounds to make light-sensitive mixtures which are useful as positive acting photoresists. The preferred class of photoactive compounds (sometimes called light sensitizers) is o-quinonediazide compounds particularly esters derived from polyhydric phenols, alkylpolyhydroxyphenones, aryl-polyhydroxyphenones, and the like which can contain up to six or more sites for esterification. The most preferred o-quinonediazide esters are derived from 2-diazo-1,2-dihydro-1-oxo-naphthlene-4-sulfonic acid and 2-diazo-1,2-dihydro-1-oxo-naphthalene-5-sulfonic acid.
Specific examples include resorcinol 1,2-naphthoquinonediazide-4-sulfonic acid esters; pyrogallol 1,2-naphthoquinonediazide-5-sulfonic acid esters, 1,2-quinonediazidesulfonic acid esters of (poly)hydroxyphenyl alkyl ketones or (poly)hydroxyphenyl aryl ketones such as 2,4-dihydroxyphenyl propyl ketone 1,2-benzoquinonediazide-4-sulfonic acid esters, 2,4,dihydroxyphenyl hexyl ketone 1,2-naphthoquinonediazide-4-sulfonic acid esters, 2,4-dihydroxybenzophenone 1,2-naphthoquinonediazide-5-sulfonic acid esters, 2,3,4-trihydroxyphenyl hexyl ketone, 1,2-naphthoquinonediazide-4-sulfonic acid esters, 2,3,4-trihydroxybenzophenone 1,2-naphthoquinonediazide-4-sulfonic acid esters, 2,3,4-trihydroxybenzophenone 1,2-naphthoquinonediazide-5-sulfonic acid esters, 2,4,6-trihydroxybenzophenone 1,2-naphthoquinonediazide-4-sulfonic acid esters, 2,4,6-trihydroxybenzophenone 1,2-naphthoquinonediazide-5-sulfonic acid esters, 2,2',4,4'-tetrahydroxybenzophenone 1,2-naphthoquinonediazide-5-sulfonic acid esters, 2,3,4,4'-tetrahydroxy-benzophenone 1,2-naphthoquinonediazide-5-sulfonic acid esters, 2,3,4,4'-tetrahydroxybenzophenone 1,2-naphthoquinonediazide-4-sulfonic acid esters, 2,2',3,4',6'-pentahydroxybenzophenone 1,2-naphthoquinonediazide-5-sulfonic acid esters and 2,3,3',4,4',5'-hexahydroxybenzophenone 1,2-naphthoquinonediazide-5-sulfonic acid esters; 1,2-quinonediazidesulfonic acid esters of bis[(poly)hydroxyphenyl]alkanes such as bis(p-hydroxyphenyl)methane 1,2-naphthoquinonediazide-4-sulfonic acid esters, bis(2,4-dihydroxyphenyl)methane 1,2-naphthoquinone-diazide-5-sulfonic acid esters, bis(2,3,4-trihydroxy-phenyl)methane 1,2-naphthoquinonediazide-5-sulfonic acid esters, 2,2-bis(p-hydroxyphenyl)propane 1,2-naphthoquinonediazide-4-sulfonic acid esters, 2,2-bis(2,4-dihydroxyphenyl)propane 1,2-naphthoquinonediazide-5-sulfonic acid esters and 2,2-bis(2,3,4-trihydroxyphenyl)propane 1,2-naphthoquinonediazide-5-sulfonic acid esters. Besides the 1,2-quinonediazide compounds exemplified above, there can also be used the 1,2-quinonediazide compounds described in J. Kosar, "Light-Sensitive Systems", 339-352 (1965), John Wiley & Sons (New York) or in S. DeForest, "Photoresist", 50, (1975), MacGraw-Hill, Inc. (New York). In addition, these materials may be used in combinations of two or more. Further, mixtures of substances formed when less than all esterification sites present on a particular polyhydric phenol, alkyl-polyhydroxyphenone, aryl-polyhydroxyphenone and the like have combined with o-quinonediazides may be effectively utilized in positive acting photoresists.
Of all the 1,2-quinonediazide compounds mentioned above, 1,2-naphthoquinonediazide-5-sulfonic acid di-, tri-, tetra-, penta- and hexa-esters of polyhydroxy compounds having at least 2 hydroxyl groups, i.e. about 2 to 6 hydroxyl groups, are most preferred.
Among these most preferred 1,2-naphthoquinone-5-diazide compounds are 2,3,4-trihydroxybenzophenone 1,2-naphthoquinonediazide-5-sulfonic acid esters, 2,3,4,4'-tetrahydroxybenzophenone 1,2-naphthoquinonediazide-5-sulfonic acid esters, and 2,2',4,4'-tetrahydroxybenzophenone 1,2-naphthoquinonediazide-5-sulfonic acid esters. These 1,2-quinonediazide compounds may be used alone or in combination of two or more.
The proportion of the light sensitizer compound in the light-sensitive mixture may preferably range from about 5 to about 40%, more preferably from about 10 to about 25% by weight of the non-volatile (e.g. non-solvent) content of the light-sensitive mixture. The proportion of total binder resin of this present invention in the light-sensitive mixture may preferably range from about 60 to about 95%, more preferably, from about 75 to 90% of the non-volatile (e.g. excluding solvents) content of the light-sensitive mixture.
These light-sensitive mixtures may also contain conventional photoresist composition ingredients such as other resins, solvents, actinic and contrast dyes, anti-striation agents, plasticizers, speed enhancers, and the like. These additional ingredients may be added to the binder resin and sensitizer solution before the solution is coated onto the substrate.
Other binder resins may also be added beside the resins of the present invention mentioned above. Examples include phenolic-formaldehyde resins, cresol-formaldehyde resins, phenol-cresol-formaldehyde resins and polyvinylphenol resins commonly used in the photoresist art. If other binder resins are present, they will replace a portion of the binder resins of the present invention. Thus, the total amount of the binder resin in the light-sensitive composition will be from about 60% to about 95% by weight of the total non-volatile solids content of the light-sensitive composition.
The resins and sensitizers may be dissolved in a solvent or solvents to facilitate their application to the substrate. Examples of suitable solvents include methoxyacetoxy propane, ethyl cellosolve acetate, n-butyl acetate, xylene, ethyl lactate, propylene glycol alkyl ether acetates, or mixtures thereof and the like. The preferred amount of solvent may be from about 50% to about 500%, or higher, by weight, more preferably, from about 100% to about 400% by weight, based on combined resin and sensitizer weight.
Actinic dyes help provide increase resolution on highly reflective surfaces by inhibiting back scattering of light off the substrate. This back scattering causes the undesirable effect of optical notching, especially on a substrate topography. Examples of actinic dyes include those that absorb light energy at approximately 400-460 nm [e.g. Fat Brown B (C.I. No. 12010); Fat Brown RR (C.I. No. 11285); 2-hydroxy-1,4-naphthoquinone (C.I. No. 75480) and Quinoline Yellow A (C.I. No. 47000)] and those that absorb light energy at approximately 300-340 nm [e.g. 2,5-diphenyloxazole (PPO-Chem. Abs. Reg. No. 92-71-7) and 2-(4-biphenyl)-6-phenyl-benzoxazole (PBBO-Chem. Abs. Reg. No. 17064-47-0)]. The amount of actinic dyes may be up to ten percent weight levels, based on the combined weight of resin and sensitizer.
Contrast dyes enhance the visibility of the developed images and facilitate pattern alignment during manufacturing. Examples of contrast dye additives that may be used together with the light-sensitive mixtures of the present invention include Solvent Red 24 (C.I. No. 26105), Basic Fuchsin (C.I. 42514), Oil Blue N (C.I. No. 61555) and Calco Red A (C.I. No. 26125) up to ten percent weight levels, based on the combined weight of resin and sensitizer.
Anti-striation agents level out the photoresist coating or film to a uniform thickness. Anti-striation agents may be used up to five percent weight levels, based on the combined weight of resin and sensitizer. One suitable class of anti-striation agents is non-ionic silicon-modified polymers. Non-ionic surfactants may also be used for this purpose, including, for example, nonylphenoxy poly(ethyleneoxy) ethanol; octylphenoxy (ethyleneoxy) ethanol; and dinonyl phenoxy poly(ethyleneoxy) ethanol.
Plasticizers improve the coating and adhesion properties of the photoresist composition and better allow for the application of a thin coating or film of photoresist which is smooth and of uniform thickness onto the substrate. Plasticizers which may be used include, for example, phosphoric acid tri-(B-chloroethyl)-ester; stearic acid; dicamphor; polypropylene; acetal resins; phenoxy resins; and alkyl resins up to ten percent weight levels, based on the combined weight of resin and sensitizer.
Speed enhancers tend to increase the solubility of the photoresist coating in both the exposed and unexposed areas, and thus, they are used in applications where speed of development is the overriding consideration even though some degree of contrast may be sacrificed, i.e. in positive resists while the exposed areas of the photoresist coating will be dissolved more quickly by the developer, the speed enhancers will also cause a larger loss of photoresist coating from the unexposed areas. Speed enhancers that may be used include, for example, picric acid, nicotinic acid or nitrocinnamic acid at weight levels of up to 20 percent, based on the combined weight of resin and sensitizer.
The prepared light-sensitive resist mixture, can be applied to a substrate by any conventional method used in the photoresist art, including dipping, spraying, whirling and spin coating. When spin coating, for example, the resist mixture can be adjusted as to the percentage of solids content in order to provide a coating of the desired thickness given the type of spinning equipment and spin speed utilized and the amount of time allowed for the spinning process. Suitable substrates include silicon, aluminum or polymeric resins, silicon dioxide, doped silicon dioxide, silicon resins, gallium arsenide, silicon nitride, tantalum, copper, polysilicon, ceramics and aluminum/copper mixtures.
The photoresist coatings produced by the above described procedure are particularly suitable for application to thermally grown silicon/silicon dioxide-coated wafers such as are utilized in the production of microprocessors and other miniaturized integrated circuit components. An aluminum/aluminum oxide wafer can be used as well. The substrate may also comprise various polymeric resins especially transparent polymers such as polyesters and polyolefins.
After the resist solution is coated onto the substrate, the coated substrate is baked at approximately 70° C. to 125° C. until substantially all the solvent has evaporated and only a uniform light-sensitive coating remains on the substrate.
The coated substrate can then be exposed to radiation, especially ultraviolet radiation, in any desired exposure pattern, produced by use of suitable masks, negatives, stencils, templates, and the like. Conventional imaging process or apparatus currently used in processing photoresist-coated substrates may be employed with the present invention. In some instances, a post-exposure bake at a temperature about 10° C. higher than the soft bake temperature is used to enhance image quality and resolution.
The exposed resist-coated substrates are next developed in an aqueous alkaline developing solution. This solution is preferably agitated, for example, by nitrogen gas agitation. Examples of aqueous alkaline developers include aqueous solutions of tetramethylammonium hydroxide, sodium hydroxide, potassium hydroxide, ethanolamine, choline, sodium phosphates, sodium carbonate, sodium metasilicate, and the like. The preferred developers for this invention are aqueous solutions of either alkali metal hydroxides, phosphates or silicates, or mixtures thereof, or tetramethylammonium hydroxide.
Alternative development techniques such as spray development or puddle development, or combinations thereof, may also be used.
The substrates are allowed to remain in the developer until all of the resist coating has dissolved from the exposed areas. Normally, development times from about 10 seconds to about 3 minutes are employed.
After selective dissolution of the coated wafers in the developing solution, they are preferably subjected to a deionized water rinse to fully remove the developer or any remaining undesired portions of the coating and to stop further development. This rinsing operation (which is part of the development process) may be followed by blow drying with filtered air to remove excess water. A post-development heat treatment or bake may then be employed to increase the coating's adhesion and chemical resistance to etching solutions and other substances. The post-development heat treatment can comprise the baking of the coating and substrate below the coating's thermal deformation temperature.
In industrial applications, particularly in the manufacture of microcircuitry units on silicon/silicon dioxide-type substrates, the developed substrates may then be treated with a buffered, hydrofluoric acid etching solution or plasma gas etch. The resist compositions of the present invention are believed to be resistant to a wide variety of acid etching solutions or plasma gases and provide effective protection for the resist-coated areas of the substrate.
Later, the remaining areas of the photoresist coating may be removed from the etched substrate surface by conventional photoresist stripping operations.
The present invention is further described in detail by means of the following Examples. All parts and percentages are by weight unless explicitly stated otherwise.
EXAMPLE 1
Synthesis of 5-Methylol-2,3,4-trihydroxybenzophenone Employing 2.5 Hours Reaction Time at 40°-47° C.
2,3,4-Trihydroxybenzophenone [300 gm (1.3 moles)] was added to a 3 liter, three neck flask equipped with mechanical agitation, a thermometer, a condenser and an addition funnel. An aqueous solution of sodium hydroxide [208 gm 98% by weight NaOH dissolved in 1 liter of distilled water (5.1 moles NaOH)] was added slowly to the flask. A dark aqueous solution of the trihydroxybenzophenone was formed rapidly. A slight exotherm was observed causing the solution temperature to rise to ˜48° C.
An aqueous 36.5% by weight formaldehyde solution [123.3 gm (1.5 moles)] was then added dropwise through the addition funnel at a controlled rate so not to cause the reaction temperature to exceed 50° C. Half the formaldehyde solution was added rapidly in five minutes and the second half over a total of 80 minutes. After addition, the reaction was allowed to proceed for an additional 80 minutes before it was acidified with a dilute 37% aqueous hydrochloric acid solution by weight [513 gm (5.2 moles HCl)]. The change in the pH of the solution to a neutral or slightly acidic was associated with a change in its color to a yellowish orange.
The reaction solution was transferred to a larger container filled with 3 liters of distilled water under vigorous agitation. The reaction solution was dripped slowly into the agitated water over 30 minutes duration. A light solid precipitate was formed. The solid product was filtered out and dried in a vacuum oven at 50° C. for about 20 hours to remove substantially all water in the product.
The dried product weighed 306.5 gm which represented a 90.7% yield based on a theoretical yield of 338 gm.
The structure of the above titled compound was confirmed by infrared spectral analysis and by proton NMR. The observed NMR ratio of the aliphatic hydrogens to the aromatic hydrogens was 0.296. Compared with the theoretical ratio value of 0.33 for this compound the product purity is 87.99 by moles. High pressure liquid chromatography detected the presence of approximately 7% by weight of trihydroxybenzophenone starting material indicating that this was the major impurity.
EXAMPLE 2
Synthesis of 5-Methylol-2,3,4-trihydroxybenzophenone Employing 2 Hours Reaction Time at 40°-45° C.
2,3,4-Trihydroxybenzophenone [300 gm (1.3 moles)] was added to a 3 liter, three neck flask equipped with mechanical agitation, thermometer, a condenser and an addition funnel. An aqueous solution of sodium hydroxide [208 gm 98% by weight NaOH dissolved in 1 liter of distilled water (5.1 moles NaOH)] was added slowly to the flask. A dark aqueous solution of the trihydroxybenzophenone was formed rapidly.
A slight exotherm was observed causing the solution temperature to rise to ˜45° C.
An aqueous 36.5% by weight formaldehyde solution [123.3 gm (1.5 moles)] was then added dropwise through the addition funnel at a controlled rate so not to cause the reaction temperature to exceed 50° C. Half the formaldehyde solution was added over a period of 70 minutes and the second half over a period of 110 minutes. The reaction solution was poured into a larger container filled with 3 liters of distilled water under vigorous agitation. The reaction mixture was acidified with a dilute 37% aqueous hydrochloric acid solution by weight [513 gm (5.2 moles HCl)]. The change in the pH of the solution to a neutral or slightly acidic was associated with the precipitation of the product in the form of a yellowish orange solid particle. The product was filtered out of solution and reslurried in fresh distilled water three times to wash off trace acid as detected by the neutral pH of the last water wash.
The product was dried in a vacuum oven at 50° C. for 24 hours to remove substantially all water.
The dried product weighed 320 gm which represented a 94.7% yield based on a theoretical yield of 338 gm.
The structure of the above titled compound was confirmed by infrared spectral analysis and by proton NMR. The observed NMR ratio of the aliphatic hydrogens to the aromatic hydrogens was 0.265. Compared with the theoretical ratio value of 0.33 for this compound the product purity is 80.3 moles. High pressure liquid chromatography detected the presence of 8.8% by weight of the trihydroxybenzophenone starting material indicating that this was the major impurity.
COMPARISON 1
Synthesis of 5-Methylol-2,3,4-Trihydroxybenzophenone Employing 26 Hours Reaction Time And An Excess Of Formaldehyde
2,3,4-Trihydroxybenzophenone [200 gm (1.3 moles)] was added to a 3 liter, three neck flask equipped with mechanical agitation, thermometer, a condenser and an addition funnel. An aqueous solution of sodium hydroxide [106.5 gm 98% by weight NaOH dissolved in 690 gm of distilled water (2.6 moles NaOH)] was added slowly to the flask. A dark aqueous solution of the trihydroxybenzophenone was formed rapidly. A slight exotherm was observed causing the solution temperature to raise to ˜42° C.
An aqueous 36.5% by weight formaldehyde solution [147 gm (1.79 moles)] was added dropwise through the addition funnel in two parts. The first portion of the formaldehyde solution [86 gm (1.05 moles)] was added over a period of 85 minutes. The reaction was then allowed to continue for 22 hours at 40°-42° C. before adding the section portion of the remaining formaldehyde solution [61 gm (0.74 moles)] over a period of 70 minutes. Approximately 70 minutes later the reaction solution was poured into a larger container filled with 3.3 liters of distilled water under vigorous agitation.
The reaction mixture was acidified with glacial acetic acid solution (156 gm) added over a 2 hour period at 28° C. The change in the solution acidity to a pH of 4 associated with the precipitation of the product in the form of a yellowish orange solid particle. The product was filtered out of solution and dried in a vacuum oven at 50° C. for 24 hours to remove substantially all water.
The dried product weighed 199.4 gm which represented a 88.25% yield based on a theoretical yield of 226 gm.
The structure of the above titled compound was not confirmed by proton NMR analysis. The theoretical NMR ratio of the aliphatic hydrogens to the aromatic hydrogens for this compound is 0.33. The observed NMR ratio of the product of this reaction was 0.08 suggesting a low purity mixture.
It is postulated that further condensation of the desired product into higher oligmers may have formed under this extended reaction time and at this higher formaldehyde level.
EXAMPLE 3
Mixed Cresol Novolak Synthesis Containing 10 Mole Percent Of 5-Methylol-2,3,4-Trihydroxybenzophenone
A mixture of m-cresol [248.28 gm (2.3 moles)], p-cresol [165.5 gm (1.53 moles)], a 37.8% aqueous solution of formaldehyde [228 gm (2.86 moles)] and oxalic acid dihydrate [1 gm (0.0081 moles)] was charged into a resin flask. The 1000 ml capacity resin flask used for this reaction was equipped with a mechanical strirrer, a water cooled condenser, a thermometer, an addition funnel, a nitrogen inlet valve and an adequate heating/cooling capacity. The reaction solution was heated up to 60° C. before the addition of the 5-methylol-2,3,4-trihydroxybenzophenone product of Example 1 was started [100 gm dissolved in 285 ml methanol/methoxy-acetoxypropane (about 0.38 moles). This solution was added to the reaction mixture through the addition funnel over a period of 1.5 hours at a temperature range of 100°-83° C. The reaction was allowed to continue at reflux temperature for another 1.5 hours before starting atmospheric distillation. The condenser was adjusted from the reflux vertical position to the horizontal distillation tilted position and a receiving flask was installed at its end. The reaction temperature was raised up to 190° C. as the water and formaldehyde were removed. At this point 335.5 gm of aqueous distillate was collected in the receiving flask. The duration of the atmospheric distillation was about 2 hours. Vacuum was applied gradually to remove unreacted cresols. The maximum temperature allowed during the vacuum distillation was 235° C. at 2 mm/Hg of pressure. Most of the residual unreacted cresols were removed rapidly before applying full vacuum. It was necessary to hold full vacuum for one hour and 40 minutes to insure the removal of essentially all unreacted cresol monomers. Nitrogen gas was used to equalize the pressure inside the flask and to avoid the oxidation of the molten novolak. The novolak was poured into an aluminum tray under an atmosphere of nitrogen and was cooled to room temperature.
420 gm of solid novolak was collected containing less than 0.5% cresol monomers by weight. The softening point of the novolak was 142.5°-143° C. determined by the ring and ball method, ASTM No. 06.03.
EXAMPLE 4
Mixed Cresol Novolak Synthesis Containing 5 Mole Percent Of 5-Methylol-2,3,4-Trihydroxybenzophenone
A mixture of m-cresol [135.6 gm (1.25 moles)], p-cresol [90.6 gm (0.84 moles)], a 37.7% aqueous solution of formaldehyde [46.6 gm (0.586 moles)], oxalic acid dihydrate [1 gm (0.0081 moles)] and the 5-methylol-2,3,4-trihydroxybenzophenone product of Example 1 [30 gm (about 0.13 moles)] were charged into a resin flask. The 1000 ml capacity resin flask used for this reaction was equipped with a mechanical stirrer, a water cooled condenser, a thermometer, a nitrogen inlet valve and an adequate heating/cooling capacity. The reaction solution was heated up to reflux (99°-100° C.) and was allowed to react for three hours before starting atmospheric distillation. The condenser was adjusted from the reflux vertical position to the horizontal distillation tilted position and a receiving flask was installed at its end. The reaction temperature was raised up to 175° C. as the water and formaldehyde were removed. At this point 93 gm of aqueous distillate was collected in the receiving flask. The duration of the atmospheric distillation was about 50 minutes.
Vacuum was applied gradually to remove unreacted cresols. The maximum temperature allowed during the vacuum distillation was 215° C. at 2 mm/Hg of pressure. Most of the residual unreacted cresols were removed rapidly before applying full vacuum, however, it was necessary to hold full vacuum for 25 minutes to insure the removal of essentially all unreacted cresol monomers. Nitrogen gas was used to equalize the pressure inside the flask and to avoid the oxidation of the molten novolak. The novolak was poured into an aluminum tray under an atmosphere of nitrogen and was cooled to room temperature. A total of 65 gm of unreacted cresols was collected in the receiving flask at the end of the vacuum distillation. 216 gm of solid novolak was collected containing less than 0.5% cresol monomers by weight. The softening point of the novolak was 156° C. determined by the ring and ball method, ASTM No. 06.03.
EXAMPLE 5
Mixed Cresol Novolak Synthesis Containing 7 Mole Percent Of 5-Methylol-2,3,4-Trihydroxybenzophenone
A mixture of m-cresol [126 gm (1.17 moles)], p-cresol [84 gm (0.78 moles)], a 36.5% aqueous solution of formaldehyde [121.5 gm (1.483 moles)], oxalic acid dihydrate [1 gm (0.0081 moles)] and the 5-methylol-2,3,4-trihydroxybenzophenone product of Example 1 [40 gm (about 0.13 moles)] were charged into a resin flask. The 1000 ml capacity resin flask used for this reaction was equipped with a mechanical stirrer, a water cooled condenser, a thermometer, a nitrogen inlet valve and an adequate heating/cooling capacity. The reaction solution was heated up to reflux (98° C.) and was allowed to react for three hours before starting atmospheric distillation. The condenser was adjusted from the reflux vertical position to the horizontal distillation tilted position and a receiving flask was installed at its end. The reaction temperature was raised up to 200° C. as the water and formaldehyde were removed. The duration of the atmospheric distillation was 1.5 hours. Vacuum was applied gradually to remove unreacted cresols. The maximum temperature allowed during the vacuum distillation was 227° C. at 2 mm/Hg of pressure. Most of the residual unreacted cresols were removed rapidly before applying full vacuum. It was necessary to hold full vacuum for 45 minutes to insure the removal of essentially all unreacted cresol monomers. Nitrogen gas was used to equalize the pressure inside the flask and to avoid the oxidation of the molten novolak. The novolak was poured into an aluminum tray under an atmosphere of nitrogen and was cooled to room temperature. 218 gm of solid novolak was collected containing less than 0.5% cresol monomers by weight. The softening point of the novolak was 160° C. determined by the ring and ball method, ASTM No. 06.03.
COMPARISON 2
Mixed Cresol Novolak Synthesis With No 5-Methylol-2,3,4-Trihydroxybenzophenone Added
A mixture of m-cresol [607.2 gm (5.62 moles)], p-cresol [404.8 gm (3.75 moles)], a 37.75% aqueous solution of formaldehyde [557 gm (7.03 moles)] and oxalic acid dihydrate 2 gm (0.016Z moles)] was charged into a resin flask. The 2000 ml capacity resin flask used for this reaction was equipped with a mechanical stirrer, a water cooled condenser, a thermometer, an addition funnel, a nitrogen inlet valve and an adequate heating/cooling capacity. The reaction solution was heated up to (100° C.) and was allowed to react at this reflux temperature for four hours before starting the atmospheric distillation. The condenser was adjusted from the reflux vertical position to the horizontal distillation tilted position and a receiving flask was installed at its end. The reaction temperature was raised up to 180° C. as the water and unreacted formaldehyde were removed. At this point 448.5 gm of aqueous distillate was collected in the receiving flask. The duration of the atmospheric distillation was about 2.5 hours. Vacuum was applied gradually to remove unreacted cresols. The maximum temperature allowed during the vacuum distillation was 235° C. at 2 mm/Hg of pressure. Most of the residual unreacted cresols were removed rapidly before applying full vacuum. It was necessary to hold full vacuum for 1.5 hours to insure the removal of essentially all unreacted cresol monomers. Nitrogen gas was used to equalize the pressure inside the flask and to avoid the oxidation of the molten novolak. The novolak was poured into an aluminum tray under an atmosphere of nitrogen and was cooled to room temperature.
838 gm of solid novolak was collected containing less than 0.5% cresol monomers by weight. The softening point of the novolak was 157.5°-157° C. determined by the ring and ball method, ASTM No. 06.03.
COMPARISON 3
Mixed Cresol Novolak Synthesis With No 5-Methylol-2,3,4-Trihydroxybenzophenone Added
This reaction was carried out in a 500 gallon reactor using a similar cresol mixture as in the above examples (60% m-cresol:40% p-cresol). The formaldehyde molar ratio to cresols was 0.62. The total reaction time employed in this process was 18 hours. In addition, the total duration of the atmospheric distillation was approximately six hours and the vacuum distillation about four hours. The novolak was dissolved in ethyl cellosolve acetate to form a 31.88% solution.
This novolak was isolated in the dry solid form by distilling off the solvent from the solution (1887 gm solution) under vacuum at temperatures not exceeding 160° C. in a similar manner to that described above. 710 gm of solid novolak was collected containing less than 0.5% cresol monomers by weight. The softening point of the novolak was 135°-138° C. determined by the ring and ball method, ASTM No. 06.03.
Table I below provides dissolution times, softening points and relative average molecular weight data of the novolaks prepared in Examples 3, 4, 5 and Comparisons 2 and 3. The data in Table I shows that 5-methylol-2,3,4-trihydroxybenzophenone-containing novolaks exhibit greater solubilities in aqueous alkaline solutions than the comparison mixed cresol novolaks having similar average molecular weights and softening points. In particular, Example 3 has a faster dissolution time than Comparison 3 and Examples 4 and 5 have a faster dissolution times than Comparison 2. The dissolution times were measured for dry one micron thick novolak coatings required to completely dissolve in an aqueous alkaline solution (HPRD-419 developer sold by Olin Hunt Specialty Products, Inc. of West Paterson, N.J.). Such coatings were prepared from novolak solutions in ethyl cellosolve acetate at approximately 25% solids content by means of spin coating. Silicon or silicon dioxide wafers were used as the coating substrates. The spin speeds employed using a Headway spinner were adjusted between 3000 to 6000 RPM to provide equal one micron coatings for all the novolak solutions according to variations in their solution viscosity as a function of their average molecular weights. The coatings were dried in a Blue M hot air circulating oven at 100°-105° C. for thirty minutes. The average molecular weights (MW) and average molecular number (MN) of these novolaks were measured by gel permination chromatography (GPC) under the following conditions:
Column Set: 500, 100, 10,000, 100 and 40 Angstroms
Solvent: Tetrahydrofuran
Detector: Refractive Index
Flow Rate: 1.5 ml/min.
Injection Volume: 300 ml
Calibration: Polystyrene standards
TABLE I______________________________________NovolakExample Molecularor Dissolution Softening WeightComparison Time, Sec. Point MW MN______________________________________Example 3 5 143 3163 342Example 4 68 156 19949 738Example 5 20 160 16252 922Comparison 2 260 157 16630 478Comparison 3 10 138 not determined______________________________________
EXAMPLE 6
Preparation of Resist Solution
Novolak prepared according to Example 3 (56 gm) was dissolved in an appropriate solvent (144 gm methoxyacetoxypropane) in a 400 ml cylindrical bottle rolled on a high-speed roller for approximately 20 hours.
A portion of this solution (158.6 gm) was transferred into a 400 ml size cylindrical amber-colored glass bottle. To this solution 11.375 gm of the photoactive compound and an additional solvent (27.9 gm methoxyacetoxypropane) were added. The bottle was rolled on a high-speed roller for 12 hours at room temperature to dissolve all solids.
The photoactive sensitizer was prepared by reacting 2,3,4-trihydroxybenzophenone with naphthoquinone (1,2)-diazide-5-sulphonyl chloride in a 1:2 molar ratio. The sensitizer resulting from this reaction is a mixture of the sulphono mono-, di- and triesters with trihydroxybenzophenone as well as some unesterified trihydroxybenzophenone.
The resulting resist solution was subsequently filtered through a 0.2 um pore-size filter using a millipore microfiltration system (100 ml barrel and a 47 mm disk were used). The filtration was conducted in a nitrogen environment under a pressure of 30 pounds per square inch. Approximately 180 ml resist solution was obtained.
EXAMPLE 7
Preparation of Resist Solution
Novolak prepared according to Example 4 (56 gm) was dissolved in an appropriate solvent (144 gm methoxyacetoxypropane) in a 400 ml cylindrical bottle rolled on a high-speed roller for approximately 20 hours.
A portion of this solution (150 gm) was transferred into a 400 ml size cylindrical amber-colored glass bottle. To this solution 10.65 gm of the photoactive compound and an additional solvent (33.7 gm methoxyacetoxypropane) were added. The bottle was rolled on a high-speed roller for 12 hours at room temperature to dissolve all solids.
The photoactive sensitizer was prepared by reacting 2,3,4-trihydroxybenzophenone with naphthoquinone (1,2)-diazide-5-sulphonyl chloride in a 1:2 molar ratio. The sensitizer resulting from this reaction is a mixture of the sulphono mono-, di- and triesters with trihydroxybenzophenone as well as some unesterified trihydroxybenzophenone.
The resulting resist solution was subsequently filtered through a 0.2 um pore-size filter using a millipore microfiltration system (100 ml barrel and a 47 mm disk were used). The filtration was conducted in a nitrogen environment under a pressure of 30 pounds per square inch. Approximately 175 ml resist solution was obtained.
EXAMPLE 8
Preparation of Resist Solution
Novolak prepared according to Example 5 (30 gm) was dissolved in an appropriate solvent (70 gm ethyl lactate) in a 200 ml cylindrical bottle rolled on a high-speed roller for approximately 20 hours.
A portion of this solution (85 gm) was transferred into a 200 ml size cylindrical amber-colored glass bottle. To this solution 6.375 gm of the photoactive compound and an additional solvent (26.68 gm ethyl lactate) were added. The bottle was rolled on a high-speed roller for 12 hours at room temperature to dissolve all solids.
The photoactive sensitizer was prepared by reacting 2,3,4-trihydroxybenzophenone with naphthoquinone (1,2)-diazide-5-sulphonyl chloride in a 1:2 molar ratio. The sensitizer resulting from this reaction is a mixture of the sulphono mono-, di- and triesters with trihydroxybenzophenone as well as some unesterified trihydroxybenzophenone.
The resulting resist solution was subsequently filtered through a 0.2 um pore-size filter using a millipore microfiltration system (100 ml barrel and a 47 mm disk were used). The filtration was conducted in a nitrogen environment under a pressure of 30 pounds per square inch. Approximately 100 ml resist solution was obtained.
COMPARISON 4
Preparation of Resist Solution
Novolak prepared according to Comparison 2 (98 gm) was dissolved in an appropriate solvent (252 gm methoxyacetoxypropane) in a 400 ml cylindrical bottle rolled on a high-speed roller for approximately 20 hours.
A portion of this solution (300 gm) was transferred into a 400 ml size cylindrical amber-colored glass bottle. To this solution 21.52 gm of the photoactive compound and an additional solvent (67.37 gm methoxyacetoxypropane) were added. The bottle was rolled on a high-speed roller for 12 hours at room temperature to dissolve all solids.
The photoactive sensitizer was prepared by reacting 2,3,4-trihydroxybenzophenone with naphthoquinone (1,2)-diazide-5-sulphonyl chloride in a 1:2 molar ratio. The sensitizer resulting from this reaction is a mixture of the sulphono mono-, di- and triesters with trihydroxybenzophenone as well as some unesterified trihydroxybenzophenone.
The resulting resist solution was subsequently filtered through a 0.2 um pore-size filter using a millipore microfiltration system (100 ml barrel and a 47 mm disk were used). The filtration was conducted in a nitrogen environment under a pressure of 30 pounds per square inch. Approximately 380 ml resist solution was obtained.
COMPARISON 5
Preparation of Resist Solution
Novolak prepared according to Comparison 3 (98 gm) was dissolved in an appropriate solvent (252 gm methoxyacetoxypropane) in a 400 ml cylindrical bottle rolled on a high-speed roller for approximately 20 hours.
A portion of this solution (300 gm) was transferred into a 400 ml size cylindrical amber-colored glass bottle. To this solution 21.52 gm of the photoactive compound and an additional solvent (46.9 gm methoxyacetoxypropane) were added. The bottle was rolled on a high-speed roller for 12 hours at room temperature to dissolve all solids.
The photoactive sensitizer was prepared by reacting 2,3,4-trihydroxybenzophenone with naphthoquinone (1,2)-diazide-5-sulphonyl chloride in a 1:2 molar ratio. The sensitizer resulting from this reaction is a mixture of the sulphono mono-, di- and triesters with trihydroxybenzophenone as well as some unesterified trihydroxybenzophenone.
The resulting resist solution was subsequently filtered through a 0.2 um pore-size filter using a millipore microfiltration system (100 ml barrel and a 47 mm disk were used). The filtration was conducted in a nitrogen environment under a pressure of 30 pounds per square inch. Approximately 350 ml resist solution was obtained.
PHOTORESIST PROCESSING
Coating of Photoresist Composition onto a Substrate
Photoresist solutions prepared in Examples 6, 7, 8 and Comparison 4 and 5 were spin-coated with a spinner manufactured by Headway Research Inc. (Garland, Tex.) onto a thermally grown silicon/silicon dioxide-coated wafers of 10 cm (four inches) in diameter and 5000 angstroms in oxide thickness. Uniform coatings, after drying, of approximately 1.2 micron in thickness were obtained at spinning velocities ranging from 4,000 to 7,000 RPM for 30 seconds. In order to obtain approximately identical film thicknesses with all resist solutions, adjustments in the employed spin speed were necessary because of the variations in resist viscosities. Table II below provides the relationship between coating film thickness and spin speed for all the resist samples.
TABLE II______________________________________Resin Spin Speed Film DryingComposition × 1000 RPM Thickness Condition______________________________________Example 6 4.0 1.23 100/105° C. 5.0 1.08 30' ovenExample 7 6.5 1.21 100/105° C. 30' ovenExample 8 4.0 1.35 100/105° C. 5.0 1.21 30' oven 7.0 1.02 30' oven 4.0 1.44 110/118° C. 5.0 1.31 50" Hot PlateComparison 4 7.0 1.22 100/105° C. 30' ovenComparison 5 5.0 1.21 100/105° C. 30' oven______________________________________
The coated wafers were baked either in an air circulating convection Blue M oven for 30 minutes at 100°-105° C. or on a hot plate for 50 seconds at a temperature range from 110° to 118° C. The dry film thicknesses were measured with a Sloan Dektak II surface profilometer unit.
EXPOSURE OF COATED SUBSTRATES
A Perkin-Elmer projection aligner model 340 Micralign was used to provide adequate UV exposures of the above photoresist coated substrates. The spectral output of this instrument covers the range from 310 to 436 nanometers. The light intensity is monitored internally in the instrument. The scan time was varied in order to provide different exposure energies from which the resist sensitivity was determined. A Hunt resolution chromium mask containing groups of lines and spaces, isolated lines and isolated spaces varying in dimensions with minimum features of 1.25 microns.
The developed resist features were equal in their dimensions to mask features at the optimum exposure energy.
An Ultratech step and repeat 1:1 projection unit, model Ultratech 1000 with a 0.31 numerical aperture was used. This exposure tool provides a narrow spectral output of the G and H Hg lines (436-405 nm). The instrument produces high light intensity and short exposure times measured in milliseconds and controlled accurately by the instrument sensors and the shutter mechanism. Variable exposure energies were used to determine optimum resist exposure energies required to reproduce mask features. The mask used contained groups of lines and spaces, isolated lines and spaces varying in their dimensions with a minimum feature size of 0.75 microns.
At optimum exposures the exposed resist image is completely removed by an optimum developer and the image dimension is equal to the corresponding mask image dimension. Optimum developers can be different for each resist formulation. Such developers were determined by obtaining the maximum development contrast between the exposed and the unexposed resist areas where no resist film loss was detected in the unexposed resist areas.
Using the above noted mask featuring a group of equal lines and spaces allowed a quick determination of optimum resist exposure energy by microscopic examination of the developed resist images. The accuracy of determining the optimum exposure by this method is within ±5 mJ/Cm 2 .
DEVELOPMENT OF EXPOSED RESIST COATED SUBSTRATES
A one minute immersion development process was used to develop exposed resist coatings. Two types of developers were employed, a metal containing sodium based developer and a tetramethylammonium hydroxide based, metal ion free developer at different concentrations adjusted for each resist system. The optimum developer concentration selected for each resist provided the minimum unexposed film thickness loss of the resist coating while maximizing its development rate in the exposed areas, thus obtaining the highest development contrast for each system. The developers used and resist sensitivities are presented in Table III.
IMMERSION DEVELOPMENT PROCESS
The resist coated wafers produced and exposed according to the preceding discussions were placed on circular Teflon boats and immersed in two liter Teflon containers filled with the appropriate developer (shown in Table III) for the duration of one minute. Agitation during the development was provided by means of nitrogen bubbling distributed evenly throughout the tank. Upon removal the wafers were rinsed in distilled water for one minute and blown dry under a stream of nitrogen gas.
Table III below provides the developers employed in processing resist samples of Examples 6, 7, 8 and Comparisons 4 and 5 as well as the resulting resist sensitivities. Waycoat Positive LSI Developer ("LSI") sold by Olin Hunt Specialty Products is a metal ion containing developer and was used diluted with distilled water as indicated in Table III. The metal ion free developer Waycoat MIF Developer ("MIF") is also sold by Olin Hunt Specialty Products, was used diluted with distilled water at the concentrations indicated in Table III below.
TABLE III______________________________________ Developer Resist Concentration SensitivityResist % LSI % MIF mJ/Cm.sup.2______________________________________Example 6 20 87-94Example 7 28 260 39.5 155 50 117 62 78 70 47-60Example 8 42 150 30 230 32 170Comparison 4 70 93 39 155Comparison 5 33 58 25.5 71______________________________________
RESIST IMAGE QUALITY & THERMAL DEFORMATION MEASUREMENTS
A. Image Quality
The quality of resist images were examined after development and prior to the hard baking step. Optical microscopic examination as well as electron scan microscopy were used. The qualitative evaluation of resist images was based on the sharpness of the upper edges of resist lines and spaces, the steepness of their profiles and the smoothness of the resist image surfaces. The slope of the vertical line connecting the top edge of the resist image with its bottom edge was used to quantitatively describe the steepness of the side wall profile.
In general, low molecular weight novolaks produce better quality resist images. This was also true for the resist systems of this invention. However, resist image quality compared at both low and high molecular weight based novolaks showed better results with novolak systems of this invention over those made with corresponding comparison novolak. This comparison is provided in Tables IV and V below.
TABLE 1V______________________________________Low Molecular Weight Novolak Based Resist Systems IMAGE QUALITY Slope Definition ofResist Angle Top Edge Surface______________________________________Example 6 89-90° Very Sharp SmoothComparison 5 85-89° Sharp Smooth______________________________________
TABLE V______________________________________High Molecular Weight Novolak Based Resist Systems IMAGE QUALITY Slope Definition ofResist Angle Top Edge Surface______________________________________Example 7Mild developers 85° Sharp Smooth(39.5%, 50%and 62% LSI)Aggresive 85° Poor Roughdeveloper poor(70% LSI)Example 8Mild developers 85-89° Very Sharp Smooth(42% LSI and30% MIF)Comparison 4Mild developers 85° Poor Smooth(39.5%, 50% poorand 62% LSI)Aggressive 85° Poor Roughdeveloper poor(70% LSI)______________________________________
B. THERMAL DEFORMATION
The developed resist images were hard baked in a convection, air circulating Blue M oven at 130° C. for 30 minutes after which the resist images were examined for distortion and thermal flow. This examination was carried out by means of optical microscopy and scan electron microscopy. An additional 30 minutes hard bake at 150° C. was applied only to resist images showing no thermal deformation or flow after the first 130° C. hard bake.
The resist thermal image deformation was described by the rounding of the image top edges and the decrease in its profile steepness. These observations were more pronounced at the edges of large resist areas than small lines.
Resist systems based on the novolaks of this invention exhibited better resistance to thermal flow than the comparison system as shown in Table VI below.
TABLE VI______________________________________ Thermal Image Deformation 130° C. 150° C. Edge Decreased Edge DecreasedRESIST Rounding Slope Rounding Slope______________________________________Example 7 No Slight Yes YesExample 8 No No No YesComparison 4 Yes Yes Yes Yes______________________________________ | A methylol-substituted trihydroxybenzophenone of the formula (I): ##STR1## This methylol-substituted trihydroxybenzophenone may be reacted with selected phenolic monomers during or after the formation of a phenolic novolak resin thereby said resin having at least one unit of formula (II): ##STR2## wherein R and R 1 are individually selected from hydrogen, a lower alkyl group having 1 to 4 carbon atoms or a lower alkoxy group having 1 to 4 carbon atoms. | 6 |
CROSS-REFERENCE TO RELATED PATENT APPLICATION
This application claims the benefit of Korean Patent Application Nos. 10-2006-0028056 and 10-2006-0028057, both filed on Mar. 28, 2006, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present embodiments relate to a plasma display panel (PDP), and more particularly, to a PDP that can prevent neon discharge in non-discharge regions around a display region of the PDP that does not have transparent electrodes (ITOless).
2. Description of the Related Art
A PDP is a flat panel display device that displays images using plasma discharge of a gas in discharge cells constituting pixels. Recently, PDPs have received much attention as large flat panel display apparatuses since they can be manufactured to be thin, have a wide viewing angle, and can display high quality images.
A conventional alternating current (AC) three-electrode surface discharge type PDP includes a front panel and a rear panel. The front panel includes a front substrate, a plurality of sustain electrode pairs that are formed on the front substrate and generate sustain discharge, an upper dielectric layer that covers the sustain electrode pairs, and a passivation film coated on the upper dielectric layer. The rear panel includes a rear substrate, a plurality of address electrodes which are formed on the rear substrate and generate address discharge together with the sustain electrode pairs, a lower dielectric layer that covers the address electrodes, and a plurality of barrier ribs that define a plurality of discharge cells constituting pixels. A sealing layer is formed using frit glass on edges of the front panel and the rear panel. After aligning the front and rear panels, the sealing layer formed of frit glass is annealed to combine the front and rear panels by melting the sealing layer. Afterwards, air in each of the discharge cells and non-discharge regions is exhausted and a discharge gas is filled in the discharge cells. The discharge gas can be a gas mixture containing Ne gas mixed with Xe gas.
When a pulse voltage greater than a discharge breakdown voltage is alternately applied to the sustain electrode pairs of each of the discharge cells, plasma discharge is generated. Xe gas atoms are excited by colliding with electrons, and the Xe gas atoms generate ultraviolet rays when the excited Xe gas atoms are stabilized. The ultraviolet rays excite red, green, and blue color phosphor layers formed on the barrier ribs, and visible light is emitted from the phosphor layers and is transmitted through the front panel forming an image. However, the neon gas atoms emit orange visible light when the excited neon gas atoms are stabilized. The orange visible light reduces color purity and contrast of the image, thereby reducing display quality. In the prior art, to avoid the color purity and contrast reducing problem, a red color filter, a green color filter, and a blue color filter are formed corresponding to the red, green, and blue color discharge cells on a side of a panel through which the visible light passes, or dielectric color filters in which color filters respectively formed one unit in a dielectric layer are used to block the orange visible light emitted from the neon gas atoms. In this way, the affect of the neon discharge in the discharge cells is reduced.
Non-discharge regions defined by an outermost barrier rib and the frit glass sealing layer are located around a display region which consists of discharge cells, and the non-discharge regions are also filled with the discharge gas that contains neon gas. End terminals of the sustain electrode pairs that generate sustain discharge pass through the non-discharge regions located on left and right sides of the PDP. During a sustain discharge, a neon discharge can occur between the sustain electrodes and scan electrodes.
In particular, in the case of ITOless PDPs that do not use transparent electrodes to reduce material costs, at least two sustain electrodes and scan electrodes respectively are used instead of using one sustain electrode and scan electrode, to achieve stable discharge and to increase light emission efficiency. Also, to prevent crosstalk between adjacent discharge cells and to increase brightness, the sustain electrodes and the scan electrodes can be modified in various ways including the numbers thereof, location arrangement, and methods of driving. In this case, neon discharge is more likely to occur in the non-discharge regions.
When neon discharge occurs in the non-discharge regions located around the discharge region, orange visible light generated from the neon discharge is transmitted through the front panel, thereby reducing display quality of images of the PDP.
SUMMARY OF THE INVENTION
The present embodiments provide a plasma display panel (PDP) that can increase bright room contrast and luminous efficiency.
According to an aspect of the present embodiments, there is provided a plasma display panel comprising: a first substrate; a second substrate which is separated from the first substrate and faces the first substrate; a plurality of barrier ribs formed between the first and second substrates and defining a plurality of discharge cells; a plurality of sustain electrodes formed between the first and second substrates, comprising inner sustain electrodes and outer sustain electrodes; a plurality of scan electrodes formed in parallel to the sustain electrodes and comprising inner scan electrodes and outer scan electrodes; a plurality of address electrodes formed between the first and second substrates and extending in a direction crossing an extending direction of the sustain electrodes and the scan electrodes; an inner sustain connection electrode that electrically connects the inner sustain electrodes formed in adjacent discharge cells arranged in an extending direction of the address electrodes; and a discharge prevention element that prevents the generation of discharge in a non-discharge region around the inner sustain connection electrode, wherein the sustain electrodes and the scan electrodes are repeatedly and alternately disposed in each of the discharge cells, and adjacent electrodes of the outer sustain and outer scan electrodes formed in the two adjacent discharge cells arranged in an extending direction of the address electrodes are electrically connected to each other.
The discharge prevention element may be a dummy barrier rib formed on the second substrate.
Some embodiments relate to a display panel wherein each of a plurality of voltages applied to the inner sustain electrodes and the outer sustain electrodes is independently controlled, and each of a plurality of voltages applied to the inner scan electrodes and the outer scan electrodes is independently controlled.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features and advantages of the present embodiments will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:
FIG. 1 is a plan view illustrating a plasma display panel (PDP) according to an embodiment;
FIG. 2 is a cross-sectional view taken along a line II-II of FIG. 1 , according to an embodiment;
FIG. 3 is a plan view illustrating a modified version of the PDP of FIG. 1 , according to an embodiment;
FIG. 4 is a diagram for explaining a method of driving a PDP according to an embodiment;
FIG. 5 is a first example timing diagram for explaining a driving signal of a PDP according to an embodiment;
FIG. 6 is a second example timing diagram for explaining a driving signal of a PDP according to an embodiment;
FIG. 7 is a plan view illustrating a plasma display panel according to another embodiment;
FIG. 8 is a plan view illustrating a modified version of the PDP of FIG. 7 , according to an embodiment;
FIG. 9 a plan view illustrating a plasma display panel according to another embodiment; and
FIG. 10 is a plan view illustrating a modified version of the PDP of FIG. 9 , according to an embodiment.
DETAILED DESCRIPTION OF THE INVENTION
The present embodiments will now be described more fully with reference to the accompanying drawings in which exemplary embodiments are shown. FIG. 1 is a plan view illustrating a plasma display panel (PDP) according to an embodiment, and FIG. 2 is a cross-sectional view taken along a line II-II of FIG. 1 .
Referring to FIGS. 1 and 2 , the PDP according to the embodiment includes a front panel and a rear panel. The front panel includes a front substrate 10 and the rear panel includes a rear substrate 30 . The rear panel includes a reflective layer (not shown) for reflecting visible light, and the front substrate 10 is formed of a transparent material such as glass so that visible light can be transmitted through the front substrate 10 . Accordingly, visible light generated from phosphor layers, which will be described later, is not transmitted through the rear panel but is transmitted through the front panel. However, the present embodiments are not limited thereto, and can also be applied to a transmission type PDP through which visible light is transmitted without reflection. A sustain electrode pair 20 that generates sustain discharge is formed on the front substrate 10 .
Sustain electrode pairs 20 that include sustain electrodes and scan electrodes are disposed parallel to each other in a discharge space of each of discharge cells 114 a and 114 b . The sustain electrodes include a plurality of outer sustain electrodes 115 and a plurality of inner sustain electrodes 111 , and the scan electrodes include a plurality of inner scan electrodes 121 and a plurality of outer scan electrodes 125 . The inner sustain electrodes 111 and the inner scan electrodes 121 are formed in parallel to each other with respect to the center of the discharge space of each of the discharge cells 114 a and 114 b , and the outer sustain electrode 115 and the outer scan electrodes 125 are respectively formed on outside the inner sustain electrodes 111 and the inner scan electrodes 121 .
The sustain electrodes and the scan electrodes are repeatedly and alternately disposed in the discharge cells 114 a and 114 b . That is, the sustain electrodes and the scan electrodes are arranged in an order such that the outer sustain electrodes 115 , the inner sustain electrodes 111 , the inner scan electrodes 121 , and the outer scan electrodes 125 are formed in parallel to each other parallel to each other in each discharge cell 114 a . In the discharge cell 114 b adjacent to the discharge cell 114 a in a vertical direction (in an extending direction of address electrodes 32 ), the outer scan electrodes 125 , the inner scan electrodes 121 , the inner sustain electrodes 111 , and the outer sustain electrodes 115 are sequentially disposed parallel to each other. In another discharge cell below the discharge cell 114 b (adjacent to the discharge cell 114 b in the extending direction of the address electrodes 32 ), the sustain electrodes and the scan electrodes are formed in parallel to each other.
The inner sustain electrodes 111 of the two adjacent discharge cells 114 a and 114 b extending in the direction in which the barrier ribs 33 extend (in the extending direction of the address electrodes 32 ), are electrically connected to each other by an inner sustain connection electrode 112 . An inner sustain terminal electrode 113 is connected to the inner sustain connection electrode 112 , and although not shown, the inner sustain terminal electrode 113 is electrically connected to a signal transmission element (not shown) such as a tape carrier package or a chip on film that transmits electrical signals for driving the inner and outer sustain electrodes 111 and 115 .
The outer sustain electrodes 115 of the two adjacent discharge cells 114 a and 114 b extending in the direction in which the barrier ribs 33 extend, are electrically connected to each other by an outer sustain connection electrode 116 . The inner sustain terminal electrode 113 is connected to the outer sustain connection electrode 116 , and is electrically connected to a signal transmission element (not shown). The outer scan electrodes 125 of the two adjacent discharge cells 114 a and 114 b extending in a direction in which the barrier ribs 33 extend are electrically connected to each other by an outer scan connection electrode 126 . An outer scan terminal electrode 127 is connected to the outer scan connection electrode 126 , and is also electrically connected to a signal transmission element (not shown) that transmits electrical signals for driving the inner and outer scan electrodes 121 and 125 .
The outer sustain electrodes 115 , the inner sustain electrodes 111 , the outer scan electrodes 125 , and the inner scan electrode 121 respectively, are closed loop type electrodes, and formed of an opaque metal that contains, for example, Cr—Cu—Cr, Ag or another material having high electrical conductivity. An upper electrode and a lower electrode of each of the outer sustain electrodes 115 , the inner sustain electrodes 111 , the outer scan electrodes 125 , and the inner scan electrodes 121 are connected by short bars 115 a , 111 a , 125 a , and 121 a , respectively. That is, the upper and lower electrodes of the outer sustain electrodes 115 are electrically connected by the short bar 115 a , and the upper and lower electrodes of the inner sustain electrodes 111 are electrically connected by the short bar 111 a . Also, the upper and lower electrodes of the outer scan electrodes 125 are electrically connected by the short bar 125 a , and the upper and lower electrodes of the inner scan electrodes 121 are electrically connected by the short bar 121 a . The short bars 115 a , 111 a , 125 a , and 121 a are formed in a direction substantially perpendicular to the extending direction of the outer sustain electrodes 115 , the inner sustain electrodes 111 , the outer scan electrodes 125 , and the inner scan electrodes 121 , and may be formed at locations corresponding to the barrier ribs 33 to prevent visible light from being blocked by the outer sustain electrodes 115 , the inner sustain electrodes 111 , the outer scan electrodes 125 , and the inner scan electrodes 121 . However, the scope of the present embodiments are not limited thereto, that is, short bars can be formed on locations corresponding to discharge spaces and not to the barrier ribs 33 . The short bars 115 a , 111 a , 125 a , and 121 a ensure the flow of current in the loops of the outer sustain electrodes 115 , the inner sustain electrodes 111 , the outer scan electrodes 125 , and the inner scan electrode 121 even though there is a loss of connection in each of the loops of the outer sustain electrodes 115 , the inner sustain electrodes 111 , the outer scan electrodes 125 , and the inner scan electrode 121 .
A front dielectric layer 11 is formed on the front substrate 10 to protect the sustain electrodes and scan electrodes by covering the sustain electrodes and scan electrodes. A passivation film 12 is formed on a surface of the front dielectric layer 11 to protect the front dielectric layer 11 and to facilitate discharge by increasing the emission of secondary electrons during discharge. The passivation film 12 can be formed of MgO, for example.
The rear substrate 30 includes address electrodes 32 formed in a direction substantially perpendicular to the direction in which the sustain electrodes and scan electrodes extend. A rear dielectric layer 31 is further formed on the rear substrate 30 to protect the address electrodes 32 by covering the address electrodes 32 . The barrier ribs 33 , are stripe-shaped in the shown embodiment, however the present embodiments are not limited thereto. The barrier ribs 33 are formed on the rear substrate 30 to define the plurality of discharge cells 114 a and 114 b in which discharge for generating visible light for displaying images occurs. The barrier ribs 33 prevent crosstalk between the discharge cells 114 a . The barrier ribs 33 according to the present embodiments are not limited to the stripe shape, and can have various polygonal horizontal cross-sections such as rectangular, hexagonal, or octagonal cross-sections; or can have circular or oval cross-sections. Red, green, and blue phosphor layers 13 are formed in the discharge cells 114 a defined by the barrier ribs 33 .
The front panel and the rear panel may be combined by a combining member such as a sealing frit (not shown). A discharge gas including Xe gas and at least one of Ne gas, He gas, and Ar gas is filled in the discharge cells 114 a.
Non-discharge cells 114 c are present in non-discharge regions on outer left and right sides of each of the discharge cells 114 a in which visible light for displaying images is generated. The non-discharge cells 114 c can be defined by the barrier ribs 33 and the sealing frit, or by the barrier ribs 33 and other barrier ribs (not shown). The discharge gas is also filled in the non-discharge cell 114 c . The inner sustain connection electrode 112 , the outer scan connection electrode 126 , and the inner scan connection electrode 122 are disposed in the non-discharge cell 114 c located on a left sided non-discharge region.
A portion of the inner sustain connection electrode 112 that generates sustain discharge and portions of the inner scan connection electrode 122 and the outer scan connection electrode 126 are disposed to face each other in the non-discharge region of the non-discharge cells 114 c . The inner sustain connection electrode 112 and the inner and outer scan connection electrodes 122 and 126 that face the inner sustain connection electrode 112 can cause unwanted neon discharge during address discharge and sustain discharge. Neon discharge will be described in brief as follows. A plasma discharge occurs by excitation energy emitted from Xe atoms while the Xe atoms are stabilized, and is accelerated through a penning effect. Penning is a reaction that accelerates an ionization reaction of an element through the formation of another element in a metastable state. Here, the metastable state atoms are neon gas atoms, and the neon discharge firstly occurs since the neon atoms emit energy ahead of the Xe atoms.
Accordingly, in order to prevent the occurrence of neon discharge, a dummy barrier rib 134 is formed on the rear substrate 30 . The dummy barrier rib 134 is formed on a location between the inner sustain connection electrode 112 and the inner and outer scan connection electrodes 122 and 126 . That is, the occurrence of the neon discharge in the non-discharge region can be prevented by blocking the discharge space between the inner sustain connection electrode 112 and the inner and outer scan connection electrodes 122 and 126 .
The dummy barrier rib 134 can be simultaneously formed when the barrier ribs 33 that define the discharge cells 114 a are formed or can be formed after the discharge cells 114 a are formed. The barrier ribs 33 can be formed using various methods such as screen printing, sand blast, lift-off, photolithography, or etching.
FIG. 3 is a plan view illustrating a modified version of the PDP of FIG. 1 . In order to prevent the occurrence of neon discharge, as depicted in FIG. 3 , additionally, a distance g between the inner sustain connection electrode 112 and the outer scan connection electrode 126 , and between the inner sustain connection electrode 112 and the inner scan connection electrode 122 can be formed greater than a distance h between the inner sustain electrode 111 and the inner scan electrode 121 .
The separated distance g between the inner sustain connection electrode 112 and the outer scan connection electrode 126 , and between the inner sustain connection electrode 112 and the inner scan connection electrode 122 can be more than twice the distance h between the inner sustain electrode 111 and the inner scan electrode 121 . The distance g may vary according to the composition of the discharge gas or the magnitude of the voltage applied. Therefore, it is understood by those of ordinary skill in the art that various changes in form and details may be made without departing from the spirit and scope of the present embodiments.
Although not shown, neon discharge can be prevented by forming the distance g between the inner sustain connection electrode 112 and the outer scan connection electrode 126 , and between the inner sustain connection electrode 112 and the inner scan connection electrode 122 to be greater than the distance h between the inner sustain electrode 111 and the inner scan electrode 121 . In this case, the distance g between the inner sustain connection electrode 112 and the outer scan connection electrode 126 , and between the inner sustain connection electrode 112 and the inner scan connection electrode 122 can be twice or greater than the distance h between the inner sustain electrode 111 and the inner scan electrode 121 .
An operation and function of a PDP according to an embodiment will now be described. FIG. 4 is a diagram for explaining a method of driving a PDP according to an embodiment. An address display separation (ADS) driving method, which is an example of a method of driving a PDP, will be described with reference to FIG. 4 .
In order to display an image on a PDP in response to external image signals, each of sixty unit image frames must be able to display 256 grey scales per second. Each of the image frames must be completely timely separated. That is, a motion image for one second can be displayed by the sixty unit image frames, which are independently displayed. To display an image, one unit image frame time is divided into eight subfield SF times, that is, from a first subfield SF 1 to an eighth subfield SF 8 , and each subfield SF consists of a series of reset discharges R 1 , R 2 , . . . R 8 , address discharges A 1 , A 2 , . . . A 8 , and sustain discharges S 1 , S 2 , . . . S 8 . Sixty unit image frames having the above configuration consecutively display images for one second to display a motion image, thereby displaying an image using the ADS driving method.
However, the PDP illustrated in FIGS. 1 and 2 employs a light emitting structure in which wall charges are accumulated in the discharge cells 114 a , and visible light is emitted due to sustain discharge generated with the aid of the wall charges. In general, to display an image, discharge is generated in the discharge cells 114 a and 114 b included in the PDP. Due to the discharge, the state of the wall charges or the amount of charged particles differ between the discharge cells 114 a and 114 b , and accordingly, the discharge generated in the discharge cells 114 a and 114 b cannot be uniformly controlled.
To uniformly control the discharge, a discharge is simultaneously generated in the entire discharge cells 114 a and 114 b by applying a voltage higher than a predetermined level. In this way, uniform states of wall charges and charged particles in the discharge cells 114 a and 114 b can be achieved. This discharge is called reset discharge.
After the reset discharge is generated, address discharge is generated. The address discharge generally denotes that, to select discharge cells 114 a and 114 b in which an image is displayed by generating visible light from the discharge cells 114 a and 114 b that are selected by the inner scan electrodes 121 , the outer scan electrodes 125 and the address electrodes 32 crossing each other, discharge is generated by applying a pulse voltage to the inner scan electrodes 121 , the outer scan electrodes 125 and the address electrodes 32 , and, as a result, wall charges are generated on inner walls of the discharge cells 114 a due to the accumulation of charged particles generated during the discharge. In this way, as described above, the address discharge is used to select the discharge cells 114 a and 114 b by accumulating wall charges on the inner walls of the discharge cells 114 a , and to cause sustain discharge, which will be described later, with the aid of the wall charges.
After the address discharge, sustain discharge is generated to display an image. The sustain discharge is generated to emit a predetermined amount of visible light from the discharge cells 114 a and 114 b selected by the address discharge by predetermined times alternately forming potential differences between the sustain electrodes and scan electrodes. The sustain discharge is substantially an operation for displaying an image.
Since wall charges are accumulated in the discharge cells 114 a where the address discharge is generated, when a voltage lower than the discharge breakdown voltage is alternately applied to the plurality of electrode pairs 111 and 121 disposed in all of the discharge cells 114 a and 114 b , a potential formed by adding a potential formed by the wall charges and a potential formed between the sustain electrodes and scan electrodes exceeds the discharge breakdown voltage. Thus, the sustain discharge is generated only in the discharge cells 114 a in which the address discharge is generated, and visible light is emitted from the discharge cells 114 a and 114 b in which the address discharge is generated.
Each of the unit image frames consists of eight sequential subfields, and the unit image frame can display a predetermined grey scale by controlling the generation of sustain discharge in each subfield. The sixty unit image frames each having a predetermined grey scale display an image for one second in one of the pixels. The images displaying for one second in each of the pixels constitute an entire image.
FIG. 5 is a first example timing diagram for explaining a driving signal of the PDP illustrated in FIGS. 1 and 2 , according to an embodiment. Referring to FIG. 5 , a unit image frame for driving the PDP is divided into a plurality of subfields, each of the subfields consisting of a reset period PR, an address period PA, and a sustain period PS.
In the reset period PR, a reset discharge is generated by applying a reset pulse composed of a rising pulse and a falling pulse to the inner and outer scan electrodes 121 and 125 , and by applying a voltage Ve to the sustain electrodes 111 and 115 from the point when the falling pulse of the reset pulse is applied to the inner and outer scan electrodes 121 and 125 . The rising pulse applied to the inner and outer scan electrodes 121 and 125 gradually increases from a voltage Vs and reaches a maximum voltage Vw. Due to applying a rising lamp signal having a gentle slope to the inner and outer scan electrodes 121 and 125 , weak discharge is generated and negative charges begin to accumulate near the inner scan electrode 121 (t 5 to t 10 ). The falling pulse applied to the inner and outer scan electrodes 121 and 125 gradually reduces from the voltage Vs, and finally reaches a voltage Vrf. A portion of the negative charges accumulated on the inner scan electrode 121 is released while discharge is generated (t 20 ).
As a result of the reset discharge, all of the discharge cells 114 a are initialized with an identical state by accumulating negative charges on the inner scan electrode 121 and positive charges on the address electrode 32 in each of the discharge cells 114 a . Thus, the discharge cells 114 a are in a state that can readily generate next address discharge. In the reset period PR t 5 to t 20 , a voltage having an identical waveform is applied to the inner scan electrode 121 and the outer scan electrode 125 .
In the address period PA, address discharge is generated by sequentially applying a scan pulse Vg to the inner scan electrodes 121 in each row and a display data signal voltage Vx to the address electrodes 32 in each column in step with the scan pulse Vg. That is, the address discharge is sequentially performed row by row in such a manner that the display data signal voltage Vx is applied to the address electrodes 32 corresponding to the discharge cells 114 a to be lighted in a row, and the display data signal voltage Vx is applied to the address electrodes 32 corresponding to the discharge cells 114 a to be lighted in the next row. Due to the address discharge, discharge cells 114 a in which sustain discharge is generated in the sustain period PS are selected. During the address period PA, a ground voltage Vg is applied to the inner scan electrode 121 , and a positive scan voltage Vsc is applied to the address electrode 32 . Also, in the address period PA, a positive voltage Ve is continuously applied to the inner sustain electrode 111 . Address discharge is generated by a wall voltage caused by negative charges near the scan electrodes 121 and a wall voltage caused by positive charges near the address electrodes 32 together with the display data signal voltage Vx. As a result, positive charges are accumulated on the inner scan electrode 121 and negative charges are accumulated on the sustain electrode 111 (t 30 ).
Since a voltage higher than a voltage applied to the inner scan electrode 121 is applied to the outer scan electrode 125 , the address discharge does not progress toward the outer scan electrode 125 . Similarly, since a voltage higher than a voltage applied to the outer sustain electrode 115 is applied to the inner sustain electrode 111 , the address discharge does not progress toward the outer sustain electrode 115 . An address discharge current is greatly reduced since the address discharge is limited in a region between the address electrodes 32 and the inner scan electrode 121 and the inner sustain electrode 111 . Here, waveforms of the voltages applied to the outer scan electrode 125 and the inner scan electrode 121 are different from each other in the period when the address discharge is generated (t 25 to t 30 ), and waveforms of the voltages applied to the inner sustain electrode 111 and the outer sustain electrode 115 are different from each other during the address period (t 20 to t 40 ).
During the address discharge, neon discharge can occur between the inner sustain connection electrode 112 formed in the non-discharge region of the non-discharge cells 114 c located on a left side of the display region and the inner scan electrode 121 and the outer scan connection electrode 126 . This is because the neon discharge has a lower breakdown voltage than that of the Xe discharge. However, a dummy barrier rib 134 according to an embodiment formed between the inner sustain connection electrode 112 and the inner scan electrode 121 and the outer scan connection electrode 126 prevents the generation of neon discharge. Also, neon discharge can be prevented since the distance g between the inner sustain connection electrode 112 and the outer scan connection electrode 126 and between the inner sustain connection electrode 112 and the inner scan connection electrode 122 is greater than the distance h between the inner sustain electrode 111 and the inner scan electrode 121 .
Accordingly, image quality of the PDP illustrated in FIGS. 1 and 2 according to an embodiment can be increased by preventing the generation of orange visible light in the non-display regions around the display region.
In the sustain period PS after the address period PA, a sustain pulse is alternately applied to the inner and outer sustain electrodes 111 and 115 and the inner and outer scan electrodes 121 and 125 . Sustain discharge is generated due to collision between the discharge gas and positive charges accumulated near the inner scan electrode 121 migrating to the inner sustain electrode 111 by applying a straight voltage Vs 1 to the inner scan electrode 121 , and negative charges accumulated near the inner sustain electrode 111 migrating to the inner scan electrode 121 by applying a ground voltage Vg. Next, another sustain discharge is generated by diffusing again the negative charges accumulated on the inner scan electrode 121 to the inner sustain electrode 111 by applying the ground voltage Vg to the inner scan electrode 121 , and migrating the positive charges accumulated on the inner sustain electrode 111 to the inner scan electrode 121 by applying the straight voltage Vs to the inner sustain electrode 111 .
The sustain discharge is performed in the discharge cells 114 a selected by the address discharge as described above. The control of brightness in the unit image frame consisting of the plurality of subfields is performed according to the number of times of sustain discharge based on a weighted grey scale allocated to each of the subfields. As a result, a grey scale brightness is displayed in each unit image frame.
The sustain pulse alternately has the straight voltage Vs and the ground voltage Vg. Waveforms applied to the inner sustain electrode 111 and the outer sustain electrode 115 during the sustain period PS is identical. Accordingly, the sustain discharge initiated between the inner sustain electrode 111 and the inner scan electrode 121 is diffused towards the outer sustain electrode 115 and the outer scan electrode 125 . As a result, the region of the sustain discharge increases, thereby increasing luminous efficiency.
During the sustain discharge, neon discharge can be generated between the inner sustain connection electrode 112 formed in the non-discharge region of the non-discharge discharge cells 114 c located on a left side of the display region and the inner scan electrode 121 and the outer scan connection electrode 126 . This is because gaps between the inner sustain connection electrode 112 and the inner scan electrode 121 and between the inner sustain connection electrode 112 and the outer scan connection electrode 126 are not large, and because the neon discharge has a lower discharge breakdown voltage than the Xe discharge. However, in the present embodiment, the dummy barrier rib 134 formed between the inner sustain connection electrode 112 and the inner scan electrode 121 and the outer scan connection electrode 126 prevents the generation of neon discharge. Also, neon discharge is prevented since the distance g between the inner sustain connection electrode 112 and the outer scan connection electrode 126 , and between the inner sustain connection electrode 112 and the inner scan connection electrode 122 is greater than the distance h between the inner sustain electrode 111 and the inner scan electrode 121 . Therefore, image quality of the PDP illustrated in FIGS. 1 and 2 according to an embodiment can be increased by preventing the generation of orange visible light in the non-display discharge cells 114 c around the display region.
FIG. 6 is a second example timing diagram for explaining a driving signal of the PDP illustrated in FIGS. 1 and 2 , according to an embodiment. Referring to FIG. 6 , during a reset period PR and a address period PA, the driving signal has the same waveforms as the waveforms of FIG. 5 . Accordingly, the functions and operations of the PDP in the reset period PR and the address period PA are identical to those described with reference to FIG. 5 .
During a sustain period PS, a sustain voltage Vs 2 applied to the outer sustain electrode 115 is higher than a sustain voltage Vs applied to the inner sustain electrode 111 , and the sustain voltage Vs 2 applied to the outer scan electrode 125 is higher than the sustain voltage Vs applied to the inner scan electrode 121 . Accordingly, a sustain discharge generated between the inner sustain electrode 111 and the inner scan electrode 121 is readily diffused towards the outer sustain electrode 115 and the outer scan electrode 125 . That is, a gap between the inner and outer scan electrodes 121 and 125 can be increased as the larger the voltage differences between the outer sustain electrode 115 and the inner sustain electrode 111 and between the outer scan electrode 125 and the inner scan electrode 121 . As a result, the discharge region increases, thereby increasing luminous efficiency of the PDP.
FIG. 7 is a plan view illustrating a PDP according to another embodiment. In explaining the present embodiment, differences between FIGS. 1 through 3 and FIG. 7 will be described.
Sustain electrodes and scan electrodes are disposed parallel to each other in a discharge space of each of a plurality of discharge cells 214 a . Each of the sustain electrodes includes an outer sustain electrode 215 and an inner sustain electrode 211 , and each of the scan electrodes includes an inner scan electrode 221 and an outer scan electrode 225 . That is, the inner sustain electrode 211 and the inner scan electrode 221 are formed parallel to each other on both sides of the center of a discharge space of each of discharge cells 214 a 214 b , and the outer sustain electrode 215 and the outer scan electrode 225 are respectively located on outsides of the inner sustain electrode 211 and the inner scan electrode 221 .
The sustain electrodes and the scan electrodes are repeatedly and alternately disposed in each of the discharge cells 114 c . That is, the sustain electrodes and the scan electrodes are formed in an order in which the sustain electrodes and the scan electrodes are formed in parallel with other in one of the discharge cells 214 a , in another discharge cell 214 b adjacent to a lower side of the discharge cell 214 a in a vertical direction (in an extending direction of address electrodes 32 ) to the discharge cells 214 a , a scan electrode and a sustain electrode are formed in parallel to each other, and, in another discharge cell (not shown) located below the discharge cell 214 b , a sustain electrode and a scan electrode are formed parallel to each other.
The outer sustain electrode 215 is a closed loop shaped electrode, and an upper electrode and a lower electrode of the outer sustain electrode 215 are respectively disposed in two adjacent discharge cells 214 a and 214 b extending in a vertical direction. Accordingly, a sustain electrode 215 b and the inner sustain electrode 211 in one discharge cell 214 a are split electrodes. The outer scan electrode 225 is also a closed loop shaped electrode, and an upper electrode and a lower electrode of the outer scan electrode 225 are respectively disposed in two adjacent discharge cells 214 a and 214 b extending in a vertical direction. Accordingly, the scan electrodes 221 and 225 in one discharge cell 214 a are split electrodes. However, the inner scan electrode 221 and the inner sustain electrode 211 are not loop shaped electrodes.
The inner sustain electrodes 211 in the two adjacent discharge cells 214 a and 214 b arranged in an extending direction of barrier ribs 33 (in an extending direction of address electrodes 32 ) are electrically connected by an inner sustain connection electrode 212 . An outer sustain terminal electrode 217 is connected to an outer sustain connection electrode 216 , and an inner sustain terminal electrode 213 is connected to the inner sustain connection electrode 212 . Thus, the outer sustain terminal electrode 217 and the inner sustain terminal electrode 213 are disposed in a left side of the PDP, and are electrically connected to each of a plurality of signal transmission elements (not shown). Also, an inner scan terminal electrode 223 and an outer scan terminal electrode 227 are disposed in a right side of the PDP, and are electrically connected to each of a plurality of signal transmission elements (not shown).
To drive the PDP according to the present embodiment, the voltage waveforms described above with reference to FIGS. 5 and 6 are applied. Neon discharge can occur in a discharge cell 214 c corresponding to a non-discharge space outside the PDP between the inner sustain connection electrode 212 and the outer scan electrode 225 . To prevent neon discharge, a dummy barrier rib 234 is formed in a location between the inner sustain connection electrode 212 of a rear substrate 30 and the outer scan electrode 225 . Due to the formation of the dummy barrier rib 234 , the generation of neon discharge between the inner sustain connection electrode 212 and the outer scan electrode 225 can be prevented, and thus, the generation of orange visible light from the non-discharge cell 214 c around a display region can be prevented.
FIG. 8 is a plan view illustrating a modified version of the PDP of FIG. 7 , according to an embodiment. Also, as depicted in FIG. 8 , neon discharge can be prevented since a distance g between an inner sustain connection electrode 212 and an outer scan connection electrode 226 , and between the inner sustain connection electrode 212 and an inner scan connection electrode 222 is greater than a distance h between an inner sustain electrode 211 and an inner scan electrode 221 . Accordingly, the degradation of image quality of the PDP according to the current embodiment can be prevented.
FIG. 9 a plan view illustrating a PDP according to another embodiment. Here, the differences between the present embodiment and the previous embodiments will be mainly described.
Sustain electrodes and scan electrodes are formed in parallel to each other in discharge spaces of each of discharge cells 314 a and 314 b . Each of the sustain electrodes includes an outer sustain electrode 315 and an inner sustain electrode 311 , and each of the scan electrodes includes an inner scan electrode 321 and an outer scan electrode 325 . The inner sustain electrode 311 and the inner scan electrode 321 are formed in parallel to each other on both sides of the center of a discharge space of each of the discharge cells 314 a and 314 b , and the outer sustain electrode 315 and the outer scan electrode 325 are respectively formed on outer sides of the inner sustain electrode 311 and the inner scan electrode 321 .
The sustain electrodes and the scan electrodes are repeatedly and alternately formed in each of the discharge cells 314 a and 314 b . That is, the sustain electrodes and the scan electrodes are formed in an order in which the sustain electrodes and the scan electrodes are formed in parallel to each other in one of the discharge cells 314 a , in another discharge cell 314 b adjacent to the discharge cells 314 a in a vertical direction (in an extending direction of address electrodes 32 ) to the discharge cells 314 a , a scan electrode and a sustain electrode are formed parallel to each other, and, in another discharge cell (not shown) located below the discharge cell 314 b , a sustain electrode and a scan electrode are formed parallel to each other.
The outer sustain electrode 315 is a closed loop shaped electrode, and an upper electrode and a lower electrode of the outer sustain electrode 315 are respectively disposed in two adjacent discharge cells 314 a and 314 b extending in a vertical direction. Accordingly, the outer sustain electrode 315 and the inner sustain electrode 311 in one discharge cell 314 a are split electrodes. The outer scan electrode 325 is also a closed loop shaped electrode, and an upper electrode and a lower electrode of the outer scan electrode 325 are respectively disposed in two adjacent discharge cells 314 a and 314 b extending in a vertical direction. Accordingly, the outer scan electrode 325 in one discharge cell 314 a is a split electrode. However, the inner scan electrode 321 and the inner sustain electrode 311 are not loop shaped electrodes.
Transparent electrodes 318 , 314 , 328 , and 324 are further formed on each of the outer sustain electrode 315 , the inner sustain electrode 311 , the outer scan electrode 325 , and the inner scan electrode 321 . That is, the outer sustain electrode 315 , the inner sustain electrode 311 , the outer scan electrode 325 , and the inner scan electrode 321 are opaque metal electrodes, and overlap the transparent electrodes 318 , 314 , 328 , and 324 which have a width greater than that of the opaque metal electrodes 315 , 311 , 325 , and 321 . Due to the formation of the transparent electrodes 318 , 314 , 328 , and 324 , the widths of the opaque metal electrodes 315 , 311 , 325 , and 321 can be reduced. As a result, the opening rate of the discharge cells 314 a and 314 b can be increased and a discharge gap can be reduced, thereby readily generating discharge.
The inner sustain electrodes 311 in the two adjacent discharge cells 314 a and 314 b arranged in an extending direction of barrier ribs 33 (in an extending direction of the address electrodes 32 ) are electrically connected to each other by an inner sustain connection electrode 312 . An outer sustain terminal electrode 317 is connected to an outer sustain connection electrode 316 , an inner sustain terminal electrode 313 is connected to an inner sustain connection electrode 312 , and the outer sustain terminal electrode 317 and the inner sustain terminal electrode 313 are disposed on a left side of the PDP and are respectively electrically connected to a plurality of signal transmission elements. Also, an inner scan terminal electrode 323 and an outer scan terminal electrode 327 are disposed on a right side of the PDP and are respectively electrically connected to a plurality of signal transmission elements.
In order to drive the PDP according to the present embodiment, the waveforms described with reference to FIGS. 5 and 6 can be applied. Neon discharge can occur in a non-discharge cell 314 c corresponding to a space between the inner sustain connection electrode 312 and the outer scan electrode 325 in a non-discharge region outside a discharge region. To prevent neon discharge, a dummy barrier rib 334 is formed in a location between the inner sustain connection electrode 312 and the outer scan electrode 325 . Due to the formation of the dummy barrier rib 334 , the generation of neon discharge between the inner sustain connection electrode 312 and the outer scan electrode 325 can be prevented, and thus, the generation of orange visible light from the non-discharge cell 314 c around a display region can be prevented.
FIG. 10 is a plan view illustrating a modified version of the PDP of FIG. 9 , according to an embodiment. Referring to FIG. 10 , neon discharge can be prevented since a distance g between the inner sustain connection electrode 312 and the outer scan connection electrode 326 and between the inner sustain connection electrode 312 and the inner scan connection electrode 322 is greater than a distance h between the inner sustain electrode 311 and the inner scan electrode 321 . Therefore, the degradation of image quality of the PDP according to the current embodiment can be prevented.
While the present embodiments have been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present embodiments as defined by the following claims. | Provided is a plasma display panel that can increase bright room contrast and luminous efficiency. The plasma display panel includes a first substrate; a second substrate which is separated from the first substrate and faces the first substrate; a plurality of barrier ribs formed between the first and second substrates and defining a plurality of discharge cells; a plurality of sustain electrodes formed between the first and second substrates, comprising inner sustain electrodes and outer sustain electrodes; a plurality of scan electrodes formed in parallel to the sustain electrodes and comprising inner scan electrodes and outer scan electrodes; a plurality of address electrodes formed between the first and second substrates and extending in a direction crossing an extending direction of the sustain electrodes and the scan electrodes; an inner sustain connection electrode that electrically connects the inner sustain electrodes formed in adjacent discharge cells arranged in an extending direction of the address electrodes; and a discharge prevention element that prevents the generation of discharge in a non-discharge region around the inner sustain connection electrode, wherein the sustain electrodes and the scan electrodes are repeatedly and alternately disposed in each of the discharge cells, and adjacent electrodes of the outer sustain and outer scan electrodes formed in the two adjacent discharge cells arranged in an extending direction of the address electrodes are electrically connected to each other. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 11/423599, filed Jun. 12, 2006, the contents of which are hereby incorporated herein by reference.
FIELD OF THE DISCLOSURE
[0002] The present disclosure relates to a multiple-compartment insulated food tray for storage and service, and more particularly an insulated food tray and method of manufacture using a durable polymer matrix wherein each main compartment is insulated.
BACKGROUND
[0003] Meals served to humans generally include multiple courses served at different temperatures. Normally, each courses is served on a different plate, often at different temperatures, and at different time intervals. In some circumstances, large groups of people must be fed where special requirements are imposed. In some environments, such as school cafeterias, incarceration facilities, hospitals, military bases, summer camps, airplanes, nursing homes, etc., food service must be provided to large groups without generating excessive dirty dishes or utensils, and those dishes and utensils must limit manipulation problems at service, provide ease in storage, be easily cleaned, protect the user from sharp objects, and even respect strict logistical restraints.
[0004] The use of food serving systems based on trays is known in the art. The first generation of trays was made of disposable structures with removable inserts. More robust trays include a light-weight frame with vertical separators designed to segregate the courses, but these trays offered little or no thermal insulation between the courses. A common example of these trays include the familiar TV dinner tray, which is able to hold frozen food for long periods of time and later be placed in a conventional oven. Trays may include compartments to separate cold foods from hot foods, wet courses from dry courses, and prevent mixing of the courses. Trays may also include compartments in which small items such as condiments can be served.
[0005] Thin-walled metallic trays are light and disposable but offer little temperature control of the food. If heated courses are placed in these trays, the trays themselves can become hot, the hands of users can be burned, and food courses can reach thermal equilibrium within minutes. Newer versions of trays include insulation placed within a shell made by the tray, but these shells are often bulky, require numerous and expensive manufacturing steps, result in very small compartment sizes, and are still vulnerable to thermal equilibrium unless they are covered by a second tray or a lid. For this reason, a thin-walled robust food tray capable of insulating the food is needed.
[0006] Another problem with existing trays is the incapacity to provide for an efficient and safe way to supply of utensils without resulting to a dedicated compartment in the tray, or an independent and external supply of utensils. Placing utensils within a compartment often results in the utensil being in contact with the food. What is needed is a food tray able to provide for utensil delivery system without negatively affecting the other functions of the food tray, such as the capacity.
[0007] Yet another problem of existing food tray technology is partial insulation resulting from stacking trays. Food place within a recessed portion of a first insulated food tray is insulated from the environment, but if the courses include hot and cold portions located in different compartments, both courses reach an intermediate thermal equilibrium quickly within the food tray. What is needed is a compartment-specific insulated food tray. The use of compartment-specific insulation may also offer odor control in order to better preserve the aroma of each course.
SUMMARY
[0008] It is an object of the present disclosure to provide an insulated, multiple-compartment food tray and lid for storage and service. The insulated food tray and lid is equipped with a circumferential, weight-activated lip and a series of female U-shaped lips located on the tops of the internal and external walls of the insulated food tray. If a lid or a second insulated food tray acting as a lid is placed on top of the first insulated food tray, an L-shaped circumferential lip and male U-shaped lip located on the bottom portion of the second tray seals the compartments from each other resulting in thermal and aromatic segregation among the compartments. The use of a long, L-shaped lip on the circumference of the insulated food trays allows for two stacked strays to be mechanically unified using the weight of the top tray on the bottom tray in any orientation where the weight of the second tray remains on the first tray.
[0009] In another embodiment of the present disclosure, a polymer with foam and blowing agents is used during the molding process to create in a first phase a hard shell in contact with the mold. In a second phase, insulation is created in the hard shell by thermal treatment and expansion of the residual polymer inserted in the mold. This two-step formation process allows for a light, robust insulated food tray with better capacity and improved properties over existing food tray technologies. In a third embodiment of the present disclosure, the insulated food trays can be stacked in a nondiscriminatory arrangement by rotating one tray in relationship with the next by a fixed angle depending on the geometry of the insulated trays.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is an exploded view of a stack of two insulated food trays and a top lid in accordance with an embodiment of this disclosure.
[0011] FIG. 2 is a side view along cut-line 2 - 2 of the exploded view of the stack of two insulated food trays and the top lid of FIG. 1 .
[0012] FIG. 3 is a top view of an insulated food tray in accordance with an embodiment of this disclosure.
[0013] FIG. 4 is a bottom view of the insulated food tray of FIG. 4 .
[0014] FIG. 5 is a detail cut view of the L-shaped lip of an assembled stack of insulated food trays and a top lid in accordance with an embodiment of the present disclosure.
[0015] FIG. 6 is a detail cut view of the U-shaped lip in the assembled stack of insulated food trays and top lid in accordance with the embodiment of FIG. 5 .
[0016] FIG. 7 is a functional diagram in accordance with a method of manufacturing an insulated food tray in accordance with an embodiment of this disclosure.
DETAILED DESCRIPTION
[0017] Referring to FIG. 1 , a stack 16 of insulated food trays 1 and lid 2 is shown. In this possible embodiment, two insulated food trays 1 are shown stacked vertically, and a lid 2 is placed on top of the upper insulated food tray 1 . It is understood by one of ordinary skill in the art that while only two insulated food trays 1 are illustrated, a stack can include a greater plurality of insulated food trays 1 .
[0018] The bottom insulated food tray 1 as shown on FIG. 1 is arranged nondiscriminatorily in relation to the top insulated food tray 1 and can be rotated in the horizontal plane by 180 degrees. While a single nondiscriminatorily arranged configuration is illustrated in FIG. 1 , it is understood by one of ordinary skill in the art that many different configurations and nondiscriminatory arrangements are possible based on a plurality of factors, including the geometry of the insulated food tray 1 and the arrangement of the different inner compartments. An illustrative but nonlimiting example includes an octagonal insulated food tray with eight compartments located circumferentially around a single center compartment. In this example, a top insulated food tray 1 could be placed nondiscriminatorily in eight orientations in relation to a bottom insulated food tray 1 by rotating the top or bottom tray by any factor of 45 degrees.
[0019] FIG. 2 shows an insulated food tray 1 of FIG. 1 comprising an upper surface member 3 of a first height 51 and a lower surface member 4 of a second height 53 connected to the upper surface member 3 to form an outer shell 21 with an inner volume 20 . An insulated material is released in the inner volume 20 in a phase of the formation process of the insulated food tray 1 .
[0020] The inner volume 20 is filled with an insulating medium as a result of the formation process of the outer shell 21 . An injection molding method for manufacturing an insulated food tray is shown in FIG. 7 . In a first step 101 , a series of agents are blended into a polymer in order to create a durable polymer matrix. A quantity of blowing agent is added to the mix. In a preferred embodiment, a range of 1% to 5% of weight is added. It is understood by one of ordinary skill in the art that while a preferred range is disclosed, the determination of the quantity and proportion of blowing agent to be added to a mix is a function of the chemical nature of the blowing agent and the chemical stability of the base polymer as processed during molding by the injection mold and associated molding apparatus. A quantity of structural foam is also added to the polymer mix. In a preferred embodiment, the range is 5% to 20%. It is also understood by one of ordinary skill in the art that as for any other agent added to the polymer mix, the determination of the quantity and proportion of structural foam needed are a function of the chemical nature of the foaming agent and the chemical stability of the base polymer in combination with any other agent as used during the process of molding by injection. In a second step 102 , the durable polymer matrix is injected into the mold using conventional injection molding techniques. It is understood by one of ordinary skill in the art that the precise amount of durable polymer to be injected is a function of the actual geometry of the insulated food tray and the expansion volume of the insulation 20 within the inner shell 21 and must be calibrated upon injection based on the parameters of the injection molding device.
[0021] In a third step 103 also shown in FIG. 7 , the polymer matrix is solidified on the outer surface of the insulated food tray in order to form an outer shell 21 in contact with the cold, inside surface of the injection mold. It is understood by one of ordinary skill in the art of injection molding that the thickness of the shell and the injection locations in the mold needed to form the plurality of ribs and structures of the insulated food tray 1 are calibrated using classical injection molding techniques. In a fourth step 104 , a fraction of the polymer matrix remaining inside the shell is heated to allow the endothermic or exothermic durable polymer matrix to generate gas to form a solid insulation material with small gas bubbles. In a preferred embodiment, nitrogen gas is released during an endothermic reaction, but it is understood by one of ordinary skill in the art that any type of release gas chemically activated during the heating phase may be used, as well as any other neutral gas or expansion solid. It is understood that activation of the foam agent and the blowing agent by heat or other activation source is a very broad technology. What is contemplated is any activation means including but not limited to heat, cold, friction, time, chemical by-products, electrical current, magnetic excitation, irradiation, vibration, and any other potential energy source able to activate an agent found within a polymer matrix and create an insulation phase. In a preferred embodiment, the heating phase is conducted during approximately six minutes and at a temperature of approximately 140 degrees F. It is understood by one of ordinary skill in the art of heating injection molded pieces that the temperature and duration of the heating phase are a function of a plurality of parameters needed to activate agents within the polymer matrix and correspond to the current best mode.
[0022] The next step of the method of manufacturing relates to cooling the insulated food tray within the injection mold 105 . In a preferred embodiment, water is used to cool the mold to facilitate stabilization of the agents and the insulation 20 within the outer shell 21 . It is understood by one of ordinary skill in the art that the insulated food tray 1 within the injection mold can be cooled using a plurality of conventional means including but not limited to air cooling, mold cooling, time cooling, and compressed gas cooling. In a next step, the insulated tray 1 is stabilized 106 before removal from the injection mold using classical techniques including but not limited to hand removal or mechanical removal.
[0023] Returning to the embodiment shown as FIGS. 1 and 2 , the upper surface 3 of a first height 51 and the lower surface 4 of a second height 53 are shown to be the same height corresponding to roughly half of the total height of the insulated food tray 1 . It is understood by one of ordinary skill in the art that while first and second heights 51 , 53 are shown in this proportion in a preferred embodiment, the respective heights can correspond to any proportion of the total height of the insulated food tray 1 as long as the functional limitations associated with stacking the insulated food trays 1 is made possible.
[0024] The upper surface member 3 is relieved to define a plurality of inner compartments 5 of at least a third height 50 of a first top lip 57 and an outer rim 7 [not shown] with a second top lip 55 of the first height 51 . The lower surface member 4 is relieved to define inner ribs 58 of a fourth height 52 with a first bottom lip 56 and a second outer rim 14 [not shown] with a second bottom lip 54 of the second height 53 . While the surface member 3 is described with the help of elements of two heights called a first height 51 and a third height 50 , respectively, it is understood by one of ordinary skill in the art that both heights may be of the same height or that any of the two heights may be higher from the bottom surface of the compartments 5 without any influence on this disclosure. The same may be said for the second height 53 and the fourth height 52 on the bottom member 4 . The use of the terms “second” and “fourth” are not indicative of the necessity of a difference in height or any indication that the second height 53 is more important than the fourth height 52 .
[0025] The contents of an inner compartment 5 in a first insulated food tray 1 , as shown in FIG. 3 , is insulated by another inner compartment 5 in the first insulated food tray 1 by placing a second insulated food tray 1 on the top of the first insulated food tray 1 so the first bottom lip 56 and the second bottom lip 54 of the second insulated food tray 1 connects with the first top lip 57 and the second top lip 55 of the first insulated food tray 1 , respectively. FIGS. 5 and 6 show two detail of the embodiment of FIGS. 1 and 2 where both bottom lips 56 , 54 of the second insulated food tray 1 connect with both top lips 57 , 55 of the first insulated food tray 1 . It is understood that while the present disclosure relates to an embodiment where the combined height of the first and second heights 51 , 53 must be approximately the same as the combined height of the third and fourth heights 50 , 52 in order to seal the compartments 5 , other heights may be contemplated that are sufficient to seal the compartments 5 . It is be understood by one of ordinary skill in the art that while the best mode of a preferred embodiment disclosed is made of a single molded element, the art of injection molding allows contemplation of the use of the merger of more than a single molded element in order to create the preferred embodiment. A nonlimiting example includes the use of a first upper surface member 3 of a first height 51 wherein a series of smaller containers would be connected to the inside portion of the relieved portion of the upper surface member in order to recreate containers 5 . The present disclosure contemplates the use of any combination of elements in order to create the essential properties of the insulated food tray disclosed herein.
[0026] In another embodiment, the seal between the first top lip 57 is made of a female U-shaped lip, and the first bottom lip 56 is made of a male U-shaped lip in order to allow for the compartment 5 to be sealed when the upper surface member 3 of a first insulating food tray 1 is placed under the lower surface member 4 of a second insulated food tray 1 . In another preferred embodiment, the second top lip 55 is made of a male U-shaped and the second bottom lip 54 is a recessed L-shaped lip. In the preferred embodiment shown as FIGS. 1-6 , the L-shaped lip is inverted and the top portion of the L-shaped lip is located inside of the volume formed by the second top lip 55 of the first insulated food tray 1 . It is understood by one of ordinary skill in the art that while U-shaped and L-shaped lips are disclosed and shown, these shapes may be made of a series of flat or curved sections assembled to recreate these shapes. It is understood that the maximum angular radius of any connecting angle is determined by the manufacturing process and molding tolerances associated with the molding process. In a preferred embodiment, the lips 56 , 54 are approximately ⅛th inch in lateral thickness and the U-shaped lip and L-shaped lip have a quasicircular head radius and a very thick wall.
[0027] As shown on FIG. 4 , support corner tabs 11 are placed on the bottom section of the L-shaped lip 54 . These tabs serve a plurality of functions including but not limited to improving locally the coverage section between both insulated food trays in a stack 16 , and protecting the first bottom lip 56 from friction and wear when the insulated food tray 1 is placed on a table or other surface. In a preferred embodiment, the support corner tabs are about 1/16th inch in height. It is understood by one of ordinary skill in the art that a plurality of support mechanisms can be used to protect the first bottom lip 56 from wear.
[0028] One of the compartments 5 includes a notch holder 12 able to receive a utensil 60 as shown using phantom lines in FIG. 1 . The notch holder is designed to hold a utensil 60 specifically designed to be used in conjunction with food courses served within one or more of the compartments 5 . In a preferred embodiment, the handle of the utensil is inserted in the notch 12 in order to protect the apprehension section of the utensil 60 from coming in substantial contact with food placed in the compartment 5 where the utensil 60 is situated.
[0029] In yet another embodiment as shown in FIGS. 1-2 , the upper surface 3 of the insulated food tray 1 is further relieved to create two side-by-side volume separators 13 . In a preferred embodiment, the volume separators 13 define condiment holders to be used in association with one of the courses placed in the containers 5 . It is understood by one of ordinary skill in the art what while two volumes are shown, different quantities or types of volumes may be contemplated. In addition, in the preferred embodiment shown, the third height 50 of the condiment sections 13 does not include a first top lip 57 to be associated with a first bottom lip 56 of an associated fourth height 52 of a second insulated food tray 1 . This configuration contemplates use where the condiment compartments 13 are not completely insulated from the surrounding immediate compartment 5 . It is understood by one of ordinary skill that any combination of sealed or unsealed first bottom lip 56 may be used in association with this disclosure depending on the desired level of insulation to be obtained.
[0030] FIG. 1-2 illustrates a situation where a first insulated food tray 1 is insulated by placing a second insulated food tray 1 on top. The figures also show the situation where the second insulated food tray 1 is insulated by placing a lid 2 on top. The lid comprises a second upper surface member 17 and a second lower surface member 18 . The lower surface member 18 is relieved to create a series of ribs 22 to mimic the lower surface 4 of the insulated food tray 1 . In the preferred embodiment, the second upper surface member 17 is flat, but it is understood by one of ordinary skill in the art that the lid may be made of a wide variety of geometries and include numerous functional features to serve any additional purpose.
[0031] FIGS. 1-2 show an exploded view of the tray stack shown in FIGS. 5-6 . When trays and/or a lid are stacked, the weight of the top trays, along with the weight of the food courses placed in the compartments 5 , serve to seal the bottom insulated food tray 1 with the top insulated food tray 1 or lid 2 . It is understood that if an insulated food tray is insulated and sealed by gravitational force, the seal may be broken if the stack 16 is rotated to a significantly vertical configuration. The disclosure provides for a stack of trays able to remain sealed as long as the weight of the top insulated food tray 1 or lid 2 pushes on the bottom insulated food trays 1 .
[0032] FIG. 3 is a top view of an insulated food tray in accordance with an embodiment of this disclosure. FIG. 4 is a bottom view of the insulated food tray of FIG. 4 . FIG. 5 is a detail cut view of the L-shaped lip of an assembled stack and top lid of insulated food trays in accordance with an embodiment of the present disclosure. FIG. 6 is a detail cut view of the U-shaped lip in the assembled stack and top lid of insulated food trays in accordance with the embodiment of FIG. 5 .
[0033] Persons of ordinary skill in the art appreciate that although the teachings of the disclosure have been illustrated in connection with certain embodiments, there is no intent to limit the invention to such embodiments. On the contrary, the intention of this disclosure is to cover all modifications and embodiments falling fairly within the scope of the teachings of the disclosure. | The present disclosure provides a multiple-compartment insulated food tray and lid for storage and service. The insulated food trays allow for two or more stacked strays to be mechanically unified using the weight of the top tray on the bottom tray in any orientation where the weight of the second tray remains on the first tray. In another embodiment of the present disclosure, a polymer with foam and blowing agents are used during the molding process to create in a first phase a hard shell in contact with the mold. In a second phase, insulation is created in the hard shell by thermal treatment and expansion of the residual polymer inserted in the mold. In a third embodiment of the present disclosure, the insulated food trays, when stacked, can be placed in a nondiscriminatory arrangement. | 0 |
BACKGROUND OF THE INVENTION
The present invention generally relates to an electric lighting circuit and, more particularly, to a headlight lighting circuit for an automobile having at least one headlight of a type capable of being selectively exposed and concealed when the headlight is turned on and off, respectively.
Automobile headlights of a type capable of being selectively exposed and concealed when the headlights are turned on and off, respectively, which headlights will be hereinafter referred to as "concealable headlights", are currently employed in fairly recently developed fascinating models of automobile. In general, the concealable headlights now in use can possibly be classified into two types, namely, cover-up type and retractable type, depending upon how the headlight is concealed. The cover-up type is the one wherein the headlight, fixed in position in the front end of the body of the automobile, is concealed by a pivotally supported or foldable cover plate when the latter is moved to a closed position to cover the headlight whereas the retractable type is the one wherein the headlight is concealed or retracted into a lamp room in the front end of the automobile body.
In both types, the movement of the cover plate or the headlight selectively between exposed and concealed positions is effected by an electric motor operatively coupled thereto by means of a link mechanism. A conventional electric circuit for this drive motor includes a motor switch so ganged together with a headlight switch for the headlight that the switching on and off of the headlight switch to turn the headlight on and off can result in the movement of the cover plate or the headlight from the concealed position towards the exposed position and from the exposed position towards the concealed position, respectively.
The conventional circuit arrangement wherein the motor switch and the headlight switch are ganged together as hereinbefore described is very convenient in that there is no possibility that an automobile driver, after having turned one of the motor and headlight switches on, fails to turn the other of the motor and headlight switches on and vice versa. In other words, no separate manipulation of the motor and headlight switches is required.
While the conventional circuit arrangement has such an advantage in particular situations, it suffers from certain disadvantages which impair its utility in actual automobiles. By way of example, where the cover plate or the headlight is required to be held in the exposed position for the purpose of, for example, cleaning of the car or prevention of freezing of the cover plate in the concealed position, the headlight is simultaneously turned on even in those cases where no light is required.
In view of the above, it has long been considered desirable if the electric circuit is so designed as to enable the motor switch to be manipulatable independently of the headlight switch so that the cover plate or the headlight can be brought to the exposed position without the headlight being turned on and, simultaneously therewith, to enable the cover plate or the headlight to be brought to the exposed position when the headlight switch is turned on.
SUMMARY OF THE INVENTION
Accordingly, the present invention has for its essential object to provide an improved electric lighting circuit for the concealable headlight for an automobile, which is effective not only to enable the cover plate or the headlight to be brought to the exposed position without the headlight being turned on, but also to enable the switching on of the headlight to result in the movement of the cover plate or the headlight to the exposed position.
Another object of the present invention is to provide an improved lighting circuit of the type referred to above, which is applicable to any one of the cover-up and retractable types of headlight without requiring any complicated wiring system.
A further object of the present invention is to provide an improved lighting circuit of the type referred to above, wherein there is no interference in operation between a circuit component for driving the cover plate or the headlight and a circuit component for lighting the headlight.
A still further object of the present invention is to provide an improved lighting circuit of the type referred to above, which can be manufactured with a minimum number of component parts and is reliable in operation.
According to the present invention, it is possible to keep the cover plate or the headlight in the exposed position irrespective of whether or not the headlight is turned on. This is particularly advantageous in avoiding the possibility that the cover plate or the headlight which has been held in the concealed position may fail to move to the exposed position by some reason, for example, by the freezing of the cover plate or the headlight to the automobile body or by the jamming of a foreign matter into a path of movement of the cover plate or the headlight. Moreover, replacement of a broken lamp element with a fresh one can readily be carried out without the electric circuit for the headlight lamp kept energized.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and features of the present invention will become apparent from the following description taken in conjunction with preferred embodiments thereof with reference to the accompanying drawings, in which:
FIG. 1 is a schematic side elevational view of a concealable headlight assembly of a retractable type shown with a drive unit;
FIG. 2 is a circuit diagram of a headlight lighting system according to one preferred embodiment of the present invention;
FIG. 3 is a diagram similar to FIG. 2, showing another preferred embodiment of the present invention;
FIG. 4(a) is a schematic perspective view of a switch element employable in any one of the circuits of FIGS. 2 and 3; and
FIGS. 4(a) and 4(b) are schematic end views of the switch element of FIG. 4(a) shown in different operative positions, respectively.
DETAILED DESCRIPTION OF THE INVENTION
Before the description of the present invention proceeds, it is to be noted that like parts are designated by like reference numerals throughout the accompanying drawings. It is also to be noted that, although the concept of the present invention is equally applicable to the concealable headlight of cover-up type, the retractable type will be described for the purpose of illustration of the present invention.
Referring first to FIG. 1, an automobile body 10, schematically shown by 10a, has at least one opening 10a defined therein and through which a concealable headlight 11 can be selectively concealed and exposed. This concealable headlight 11 comprises a substantially conical lamp housing 12 having an apex portion connected to a portion of the automobile body 10 for pivotal movement between an exposed position, shown by the solid line, and a retracted position shown by the chain line, it being to be understood that, when the lamp housing 12 is in the exposed position, the headlight 11 is exposed outside the automobile body 10 and, when the lamp housing is in the retracted position, the headlight 11 is concealed within the automobile body 10. A cover plate 13 is rigidly mounted on the lamp housing 12 for pivotal movement together with the lamp housing 12 and serves to close the opening 10a when the lamp housing 12 is held in the retracted position.
For effecting the pivotal movement of the lamp housing 12 in the manner described above, either the lamp housing 12 or the cover plate 13, for example, the lamp housing 12 so far illustrated, is operatively coupled to an electric motor Mo through a transmission system. The transmission system includes a reduction gear unit 14 of any known construction, which may be rigidly mounted on a housing for the motor Mo and which has an output shaft 14a rotatable at a reduced speed with respect to the speed of rotation of the motor Mo, a crank arm 15 rigidly mounted on the output shaft 14a of the reduction gear unit 14 for rotation together with the shaft 14a, and a connecting link 16 having one end rotatably connected to the crank arm 15 and the other end pivotally connected to the lamp housing 12.
So far illustrated, the transmission system is so designed that one complete rotation of the crank arm 15 together with the output shaft 14a of the reduction gear unit 14 can result in a reciprocal movement of the lamp housing 12 between the exposed and retracted positions. However, any other suitable transmission system known to those skilled in the art may be employed in the present invention.
It is to be noted that, although in FIG. 1 the lamp housing 12 has been shown and described as pivotally connected to the automobile body 10, such an alternative is possible that the cover plate 13 be pivotally connected to the automobile body 10 while the lamp housing 12 is supported by the cover plate 13.
The motor Mo is, according to the present invention, electrically associated with a switch for the headlight 11 in the manner which will now be described with reference to FIGS. 2 and 3 showing respective embodiments of the present invention.
Referring now to FIG. 2, the automobile lighting circuit shown therein comprises a light switch 17 of a type having a movable contact 17a, electrically connected to a battery power source E, and first, second and third fixed contacts 17b, 17c and 17d. While the movable contact 17a is engaged to the first fixed contact 17b when the light switch 17 is turned off, the second and third fixed contacts 17c and 17d are electrically connected to the ground respectively through an auxiliary lamp 18 and a headlight lamp 19. The auxiliary lamp 18 may be a fog lamp or any other warning lamp well known to those skilled in the art whereas the headlight lamp 19 is housed within the lamp housing 12 and is of any known construction.
Operatively associated with the light switch 17 is a slave switch 20 of a type having a movable contact 20a electrically connected to the battery power source E, and first, second and third fixed contacts 20b, 20c and 20d. The movable contact 20a of the slave switch 20 is so manipulatable so movable together with the movable contact 17a of the light switch 17 as to engage the first to third fixed contacts 20b, 20c and 20d one at a time when the movable contact 17a of the light switch 17 is engaged to the first to third fixed contacts 17b, 17c and 17d, respectively.
The lighting circuit further comprises a motor drive circuit including a relay coil 21 having one end connected to a selector switch 22 and the other end grounded, and a relay switch 23 having a movable contact 23a, grounded through the motor Mo, and a pair of fixed contacts 23b and 23c respectively connected to the ground and the battery power source E. The relay switch 23 is of a type having its movable contact 23a normally biased to engage the first fixed contact 23b when and so long as the relay coil 21 is deenergized, but engageable to the second fixed contact 23c when the relay coil 21 is energized.
The selector switch 22, which may be a limit switch, has a movable contact 22a, electrically connected to the relay coil 21, and first and second fixed contacts 22b and 22c which are respectively connected through a first manipulatable switch 24 to the power source E and through a second manipulatable switch 25 to both of the first and second fixed contacts 20b and 20c of the slave switch 20, said first and second manipulatable switches being so operatively associated with each other that the switching off of one of the first and second manipulatable switches 24 and 25 can results in switching on of the other of the first and second manipulatable switches 24 and 25. The selector switch 22 is so designed that the movable contact 22a is engaged to the first fixed contact 22b when the lamp housing 12 is held in the retracted position as shown by the chain line in FIG. 1 and to the second fixed contact 22c when the same lamp housing 12 is held in the exposed position as shown by the solid line in FIG. 1. For this purpose, the movable contact 22a of the selector switch 22 is responsive to a parameter representative of the movement of the lamp housing 12 between the exposed and retracted positions in such a manner that it can be engaged to the first fixed contact 22b in response to or upon arrivabl of the lamp housing 12 at the retracted position and to the second fixed contact 22c in response to or upon arrival of the lamp housing 12 at the exposed position.
In one form of the selector switch 22, a switch assembly of a construction shown in FIGS. 4(a) to 4(c) may be employed, which will now be described.
The switch assembly comprises a rotor 30, rigidly mounted on, or otherwise supported in position in any suitable manner for rotation at a speed equal to the speed of rotation of, the output shaft 14a of the reduction gear unit 14, and first, second and third contact brushes 31, 32 and 33. The rotor 30 is made of an electroconductive material and has a first cutout 30a defined on a portion of the peripheral face thereof and a central recess 30b defined therein in coaxial relation to the axis of rotation of the rotor 30, said recess 30b being communicated to a second cutout 30c which extends radially outwardly from the wall defining the recess 30b. In this construction, the first contact brush 31 is always engaged to an annular face of the rotor 30 by the effect of its own resiliency and, therefore, constitutes the movable contact 22a of the selector switch 22 together with the rotor 30, while the contact brushes 32 and 33 constitute the respective first and second fixed contacts 22b and 22c of the selector switch 22.
When the switch assembly of the construction shown in FIGS. 4(a) to 4(c) is practically employed, it will readily be understood that the contact brush 32 is electrically connected to the contact brush 31 through the rotor 30 with the tip of the contact brush 33 accommodated within the cutout 30a is electrically insulated relation to the rotor 30, as best shown in FIG. 4(b) when the lamp housing 12 is held in the retracted position while, when the lamp housing 12 is held in the exposed position, the contact brush 33 is electrically connected to the contact brush 31 through the rotor 30 with the tip of the contact brush 32 accommodated within the cutout 30c in electrically insulated relation to the rotor 30 as best shown in FIG. 4(c). However, during the movement of the lamp housing 12 from the retracted position towards the exposed position or from the exposed position towards the retracted position, all of the contact brushes 31 to 33 are electrically connected to each other and this does not involve any problem in practical application as will readily be understood from the subsequent description. It is to be noted that, although the rotor 30 has been described as made of an electroconductive material, it may be made of any electrically insulating material provided that an electroconductive coating be appied to the annular face of the rotor 30.
Referring back to FIG. 2, for the purpose of indicating an operating condition of the motor Mo to an automobile driver, an indicator lamp 26 is employed. This indicator lamp 26 is electrically connected to the movable contact 23a of the relay switch 23 through a diode 27 so that, during the rotation of the motor Mo resulting from the engagement of the movable contact 23a to the second fixed contact 23c as will be described later, the indicator lamp 26 can be turned on to show that the motor Mo is in operation, that is, the lamp housing 12 is being moved from the exposed position towards the retracted position or from the retracted position towards the exposed position.
The lighting circuit of the construction described above with particular reference to FIG. 2 operates in the following manner.
Under the condition as shown in FIG. 2 wherein the movable contacts 17a and 20a of the associated switches 17 and 20 are respectively engaged to the first fixed contacts 17b and 20b and the first and second manipulatable switches 24 and 25 are respectively turned off and on, the lamp housing 12 is held in the retracted position as shown by the chain line in FIG. 1 and the movable contact 22a of the selector switch 22 is engaged to the first fixed contact 22b.
Starting from the condition shown in FIG. 2, assuming that the movable contact 17a of the light switch 17 is engaged to the third fixed contact 17d to energize the headlight lamp 19 after having moved past the position of the second fixed contact 17c, the movable contact 20a of the slave switch 20 is also engaged to the third fixed contact 20d. Upon engagement of the movable contact 20a to the third fixed contact 20d, an electric current flows from the power source E to the ground through the slave switch 20, then through the selector switch 22 and finally through the relay coil 21 thereby energizing the relay coil 21. The energization of the relay coil 21 results in engagement of the movable contact 23a to the second fixed contact 23c of the relay switch 23 and, therefore, the motor Mo is supplied with an electric power from the power source E through the relay switch 23.
When the motor Mo is energized in the manner described above, the lamp housing 12 is moved from the retracted positon towards the exposed position with the headlight lamp 19 within the lamp housing 12 being turned on. Simultaneously with the rotation of the motor Mo, the indicator lamp 26 is turned on to show to the automobile driver that the motor Mo is in operation.
Subsequent arrival of the lamp housing 12 at the exposed position causes the movable contact 22a of the selector switch 22 to engage the second fixed contact 22c, thereby interrupting the supply of the electric power through the relay coil 21. Accordingly, the relay coil 21 is deenergized and the movable contact 23a of the relay switch 23 is engaged to the first fixed contact 23b to connect the motor Mo to the ground through the relay switch 23, the consequence of which is that the motor Mo is braked by the dynamic braking effect with the lamp housing 12 held in the exposed position.
When the movable contact 17a of the light switch 17, which has been engaged to the third fixed contact 17d, is subsequently engaged to the second fixed contact 17c or the first fixed contact 17c, the movable contact 20a of the slave switch 20 is also engaged to the second fixed contact 20c or the first fixed contact 20b, repectively. Whenever the movable contact 20a of the slave switch 20 is engaged to the second fixed contact 20c or the first fixed contact 20b, the electric power from the power source E can be supplied to the selector switch 22 through the slave switch 20 because the first and second fixed contacts 20b and 20c are connected to each other. In this condition, since the second manipulatable switch 25 is switched on, the electric current from the power source E flows through the relay coil 21 through the second manipulatable switch 25 and then through the selector switch 22 having its movable contact 22a then engaged to the second fixed contact 22c. Accordingly, the movable contact 23a of the relay switch 23 is again engaged to the second fixed contact 23c to enable the motor Mo to rotate to complete the latter half of 360° rotation. Consequently, the lamp housing 12 in the exposed position is returned back towards the retracted position with the headlight lamp 19 within the lamp housing 12 turned off. The arrival of the lamp housing 12 at the retracted position causes the movable contact 22a of the selector switch 22 to engage the first fixed contact 22b and, therefore, the relay coil 21 is deenergized with the movable contact 23a of the relay switch 23 consequently engaged to the first fixed contact 23b. As is the case with the movement of the lamp housing 12 from the retracted position to the exposed position, the engagement of the movable contact 23a of the relay switch 23 to the first fixed contact 23b results in electrical connection of the motor Mo to the ground and, therefore, the motor Mo is braked by the dynamic braking effect to halt the lamp housing 12 at the retracted position.
Where the lamp housing 12 held, for example, in the retracted position is desired to be moved to the exposed position independently of the switching on and off of the headlight lamp 19, what is necessary is to turn the first manipulatable switch 24 on. The switching on of the first manipulatable switch 24 results in switching off of the second manipulatable switch 25 on one hand and the electric current is supplied from the power source E to the relay coil 21 through the first manipulatable switch 24 and then through the selector switch 22 having its movable contact 22a engaged to the first fixed contact 22b. Therefore, the motor Mo is rotated to move the lamp housing 12 from the retracted position towards the exposed position in a similar manner as is the case with the supply of the electric current to the relay coil 21 through the slave switch 20.
However, the return of the lamp housing 12 from the exposed position back to the retracted position can be effected by switching the first and second manipulatable switches 24 and 25 off and on, respectively, only when the movable contact 20a of the slave switch 20 is engaged any one of the first and second fixed contacts 20b and 20c. In any event, the first and second manipulatable switches 24 and 25 are inoperative when the headlight lamp 19 is turned on, that is, the movable contacts 17a and 20a of the associated switches 17 and 20 are respectively engaged to the third fixed contacts 17d and 20d.
Where the switch assembly of the construction shown in and described with reference to FIGS. 4(a) to 4(b) is employed for the selector switch 22, it will readily be seen that, during the first half of one complete rotation of the motor Mo in which the lamp housing 12 is moved from the retracted position towards the exposed position, the contact brush 31 is kept in electrical contact with the contact brush 32 through the rotor 30 being rotated and, during the latter half of the complete rotation of the motor Mo in which the lamp housing 12 is moved from the exposed position towards the retracted position, the contact brush 31 is kept in electrical contact with the contact brush 33 through the same rotor 30 being rotated. In practice, during the electrical connection achieved between the contact brushes 31 and 32 through the rotor 30 being rotated, the contact brush 33 is also electrically connected to any one of the contact brushes 31 and 32 through the rotor 30, but no electric power is supplied to the contact brush 33. Similarly, during the electrical connection achieved between the contact brushes 31 and 33 through the rotor 30 being rotated, the contact brush 32 is also electrically connected to any one of the contact brushes 31 and 33 through the rotor 30, but no electric power is supplied to the contact brush 32.
In the foregoing description, one motor Mo has been described as used for moving one lamp housing 12 between the retracted and exposed position. However, the number of the lamp housings to be moved by one motor may not be limited to one such as shown, but may be two or more, in which case a more complicated transmission system as compared with that shown in FIG. 1 will be required. Alternatively, a plurality of motors one for each lamp housing may be employed, the example of which is shown in FIG. 3.
Referring now to FIG. 3, the circuit shown therein is advantageously employable in most automobiles having left-hand and right-hand headlights spaced apart from each other with an engine room positioned therebetween. In the circuit shown in FIG. 3, since an additional motor drive circuit identical in construction with the motor drive circuit which has been described as including the relay coil 21 and its associated relay switch 23, the selector switch 22 and the motor Mo, is employed in association with an additional headlight lamp 19' and is electrically connected in parallel to the motor drive circuit shown and described with reference to FIG. 2, the operation of the circuit shown in FIG. 3 is believed to be self-explanatory and can readily be understood by those skilled in the art. It is, however, to be noted that like components of the additional motor drive circuit similar to that employed in the motor drive circuit shown and described with reference to FIG. 2 are shown by like reference numerals and characters with respective primes given thereto.
However, in the circuit shown in FIG. 3, for avoiding any possible interference between the motor drive circuits respectively designated by MDC and MDC' in FIG. 3, diodes 28, 29, 28' and 29' are employed. Unless these diodes 28, 29, 28' and 29' are employed, there will arise a possible interference between the motor drive circuits MDC and MDC', for example, when there is a delay in operation between the motors Mo and Mo'. By way of example, where the switch assembly of the construction shown in FIGS. 4(a) to 4(c) is employed for each of the selector switches 23 and 23', there is the possibility that the contact brushes 31, 32 and 33 are still electrically connected to each other through the rotor of the switch assembly in one motor drive circuit MDC even when the contact brush 32 of the switch assembly in the other motor drive circuit MDC', which has been engaged to the contact brush 32 through the rotor is completely switched over to the contact brush 33. In this case, the electric current fed to the relay coil 21 through the switch assembly in the motor drive circuit MDC will also be fed to the relay coil 21' through the switch assembly in the motor drive circuit MDC', resulting in an erroneous operation of the circuit. Accordingly, the use of the diodes 28, 29, 28' and 29' is recommended for avoiding such an interference as described above.
In addition, where an additional auxiliary lamp 18' is employed together with the auxiliary lamp 18, these lamps 18 and 18' may be used as indicator lamps for showing the width of the automobile body in the night.
Although the present invention has fully been described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparent to those skilled in the art. By way of example, the or each motor Mo and Mo' may be of a reversible type. Moreover, instead of the use of a single motor for driving the cover plate or the headlight between the concealed and exposed positions, separate motors one for driving the cover plate or the headlight from the concealed position towards the exposed position and the other for driving the cover plate or the headlight from the exposed position back towards the concealed position may be employed. In this case of the use of the separate motors, the relay coil 21 and its associated switch 23 and the selector switch 22, so far as the embodiment shown in FIG. 2 is involved, may be omitted and, instead, the separate motors may be electrically connected respectively to the power supply lines which have been described as respectively connected to the fixed contacts 22b and 22c. However, in this possible circuit arrangement wherein the separate motors are employed, additional switch means are required for alternately bringing these separate motors into operation, as can readily be understood by those skilled in the art.
In addition, the use of the auxiliary lamp 18 is not always essential and, therefore, each of the switches 17 and 20 may be of a type having at least two switching positions.
Furthermore, although the present invention has been described as applied to the retractable type wherein the lamp housing 12 is supported by the pivotally supported cover plate 13, the concept of the present invention can equally be applicable not only to the cover-up type, but also to another form of the retractable type wherein the lamp housing is pivotally supported at its front so that, when the lamp housing is concealed, the lamp housing can be held in the lamp room with the lamp element therein substantially facing the sky.
Accordingly, such changes and modifications are to be understood as included within the true scope of the present invention unless they depart therefrom. | An automobile headlight lighting apparatus which has a light unit, including a headlight lamp, adapted to be selectively concealed and exposed relative to a light chamber, and further has a light switch for energizing the headlight lamp with electric power supplied thereto. The apparatus further has a drive unit operable to cause the light unit to be selectively concealed and exposed. The drive unit is operated in response to the switching on of the light switch. For enabling the drive unit to be operated independently of the light switch, an additional electric circuit is provided for operating the drive unit to cause the light unit to be selectively concealed and exposed. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates to a boat latch. The latch of the present invention is of assistance in the retrieval of boats onto a trailer.
BACKGROUND OF THE INVENTION
[0002] Boats carried on trailers are used for both recreational and commercial purposes in significant numbers. Typically boats would be launched from and retrieved from an inclined boat-launching ramp or similar. The boat is secured to the trailer by a latch attaching to the bow of the boat. The boat is released by lowering the boat and trailer into the water to a sufficient depth to allow the boat to float and then releasing the latch. The procedure is reversed when the boat is retrieved: thus, the boat is manoeuvred onto the trailer and then secured by the latch.
[0003] The operation is not always easily achieved and, recovery of the boat from the water onto the trailer, in particular, can be difficult to achieve. The present invention offers an alternative to existing boat trailer latches. The boat trailer latch of the invention is particularly suited to new skid bed/roller bed trailer design, which allows the boat to be driven up on to the trailer to its resting position.
SUMMARY OF THE INVENTION
[0004] Therefore according to a first aspect of the present invention there is provided a boat latch for securing a boat or the like having a bow ring to a trailer including,
a roller mount assembly having a roller adapted to guide the bow of a boat into position said roller being attached to an upper end of a kicker arm, said kicker arm being pivotally mounted in a housing; a locking pin assembly movable between a cocked and a free position; whereby as a boat is guided into position against the roller mount assembly a rotation of said kicker arm may be induced by pressure exerted against the roller by a boat to thereby activate the locking pin at a position wherein the locking pin engages the bow ring to thereby secure the boat to the trailer.
[0008] Preferably, the kicker arm is biased into a disengaged position. More preferably, the kicker arm is biased into position by a compression spring acting against a rear upper side of the kicker arm.
[0009] Preferably, the locking pin is biased into an engaged position and may be secured in the cocked position against a stop
DESCRIPTION OF DRAWINGS
[0010] The above and other objects, features, and advantages of the present invention will be apparent from the following detailed description of a preferred embodiment in conjunction with the accompanying drawings. In the drawings:
[0011] FIG. 1 shows a boat located on a boat trailer incorporating a latch in accordance with the present invention;
[0012] FIG. 2 illustrates in cross-sectional side view the latch of the present invention in a detached position;
[0013] FIG. 3 illustrates in cross-sectional side view the latch of the present invention in an attached position;
[0014] FIG. 4 represents in a first perspective view the latch of the present invention removed from a trailer as viewed from below;
[0015] FIG. 5 represents in a second perspective view the latch of the present invention removed from a trailer as viewed from above; and
[0016] FIG. 6 shows an alternate side view of the latch showing a boat secured by a locking pin; and
[0017] FIG. 7 illustrates in schematic side view an alternative embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] The following detailed description of the invention refers to the accompanying drawings. Although the description includes exemplary embodiments, other embodiments are possible, and changes may be made to the embodiments described without departing from the spirit and scope of the invention. Wherever possible, the same reference numbers will be used throughout the drawings and the following description to refer to the same and like parts.
[0019] Shown in FIG. 1 is a boat trailer latch 10 in accordance with a first aspect of the present invention. The latch 10 is attached to, and forms a part of a conventional boat trailer 12 . A boat 14 is shown in the secured position in the drawing.
[0020] The boat latch 10 can be seen in greater detail in FIGS. 2-5 .
[0021] The latch 10 includes a mounting roller 16 located in a roller-mount assembly 18 . As can be seen from the drawings the mounting roller 16 is held generally horizontally in use and is adapted to contact the bow of the boat 14 during retrieval. The mounting roller 16 is freely rotatable about a horizontal axis. The roller mount assembly 18 serves to hold the roller 16 in position and consists of a pair of side arms 22 attached to the roller at ends thereof through an axis 24 of the roller 16 , each of the side arms 22 projecting from a base member 26 to thereby complete the roller-mount assembly 18 . The roller 16 is of a type conventionally used in boat trailers and is manufactured of nylon or other suitable material.
[0022] Extending generally downwardly from the base member 26 is a kicker arm 28 . The kicker arm 28 is seen to advantage in FIGS. 2 and 3 . The kicker arm 28 consists of a flat plate having a generally central transverse pivot point 30 . The pivot 30 is, in turn, secured in within and against the walls of a channel member 32 . The channel member 32 is approximately L shaped having a longer limb 34 and a shorter limb 36 . The longer limb 34 is attached, through a mounting plate 37 , to an upright 38 extending from the boat trailer 12 . The shorter 36 limb of the channel member 32 is open-ended to allow the kicker arm 28 to extend upwardly through the open end to the base member 26 .
[0023] It can be seen from the drawings that the kicker arm 28 occupies most of the length of the shorter limb 36 . As has been noted the kicker arm 28 is secured to the channel 32 by a pivot point 30 . The kicker arm 28 is generally freely rotatable about the pivot 30 within the confines of the channel member 32 . Nylon bushes and washers and a split pin are used to secure this arrangement and facilitate the free movement of the kicker arm 28 .
[0024] The kicker arm 28 is, however subject to influences beyond the mere shape of the channel 32 .
[0025] An uppermost part of the kicker arm 28 has a rearmost projecting tang 40 . The tang 40 is received in a cylindrical housing 42 positioned on an inner wall of the located within the shorter limb 36 of the channel member 32 . The housing 42 also serves to hold a kicker arm compression spring 44 . The outer edge of the kicker arm 28 is profiled and cut so as to allow a close fit between the kicker arm 28 and the housing 42 . The kicker arm compression spring 44 acts on the upper end of the kicker arm 28 to bias the kicker arm into a resting position.
[0026] Thus, in the orientation shown in the drawings the kicker arm 28 is biased by the compression spring 44 so that it maintains an upright position, and more specifically, the kicker arm 28 is biased in a clockwise direction. However, the kicker arm is attached at its upper end the roller 16 . Force acting on the roller 16 is therefore able to counteract the effect of the compression spring 44 as indicated in FIG. 2 .
[0027] At a lowermost end of the kicker arm 28 there is a lower tang 46 that is forwardly projecting. An aperture 49 is cut into the channel member 32 to allow the tang 46 to extend therethrough. Counter clockwise rotation of the kicker arm 28 about the pivot point 30 allows the tang 46 to contact a locking pin 48 . As will be described the movement of the locking pin 48 activates the locking mechanism.
[0028] The locking pin mechanism is positioned forwardly of the kicker arm 28 and is, in use, closer to the boat 14 . A pair of parallel, outermost forwardly extending flanges 50 is attached one to each side of the shorter limb of the channel member 32 . The flanges 50 can be seen most clearly in FIG. 4 .
[0029] The flanges 50 terminate in outwardly directed guide wings 52 . The guide wings 52 serve to avoid damage to the boat as the boat 14 is guided onto the trailer 12 . The guide wings 52 are covered in a nylon material. The guide wings 52 , in use, rest below the roller 16 and act in concert with the roller 16 to position the boat during retrieval.
[0030] The locking pin 48 is a U shaped member that passes through, and is secured in, the flanges 50 and then turns through 180° to pass below the flanges 50 . The locking pin 48 also passes through a barrel 54 positioned adjacent a flange 50 . Within the barrel 54 is a locking pin spring and associated washer. The locking pin spring ensures that the locking pin 48 is maintained in position with the lower arm passing below the guide wings 52 and flanges 50 . By pulling on the locking pin 48 it is possible to act against the locking pin spring and to withdraw the locking pin 48 .
[0031] The locking pin 48 can be withdrawn against the action of the locking pin spring to a cocked position. The locking pin 48 is maintained in this position by the lower arm of the U-shape bearing against a locking pin stop plate 56 attached to an outer surface of the channel member 32 .
[0032] As the boat 14 is driven forward on to the trailer 12 the guide wings 52 locate the D-shackle or U-bolt on the bow of the boat to its final resting position. The bow of the boat 14 then encounters the roller 16 , which then rotates on its horizontal axis 24 . At the same time the movement of the boat against the roller 16 exerts a pressure thereon that results in a rotation of the roller 16 backwards, that is in a counter clockwise direction as viewed from FIG. 2 around the pivot point 30 and against the action of the compression spring 44 . This of course rotates the whole of the kicker arm 28 and the lowermost point of the kicker arm 28 and the tang 46 are also rotated counter clockwise and the tang 46 emerges through the aperture 48 to strike the lower arm of the locking pin 48 . The locking pin 48 is thereby moved forwardly and released from the locking pin stop plate 56 . The spring in the barrel 54 shoots the locking pint 48 across the bow of the boat passing through the locking pin 48 through the D-shackle or U-bolt on the bow of the boat thereby securing the boat to the trailer.
[0033] Thus then, as the boat is driven, winched or otherwise hauled onto the trailer the operator is in a position to monitor the gradual movement of the boat and, at a point when the locating the D-shackle or U-bolt on the bow of the boat in line with the desired resting position. On the trailer, the action of the boat moving against the roller 16 activates the locking pin 48 out of the cocked position, that is, engagement with the stop plate 56 and the locking pin moves to collect the boat through the shackle.
[0034] To facilitate this process the end of the locking pin that passes through the shackle on the boat is tapered to allow easy entry through the shackle. Once the boat has been secured an R clip 58 can be used to lock the locking pin 48 against inadvertent release. In addition, a washer 60 is fixed to the rear side of the locking pin 48 to thereby prevent excess travel of the pin.
[0035] The latch 10 of the invention may incorporate additional features including a safety catch 62 that loops over the lower arm of the locking pin 48 an prevents inadvertent firing of the pin.
[0036] Shown in FIG. 7 is an alternative form of the present invention. The boat latch 100 shown in FIG. 7 is in many respects similar to the latch 10 shown in FIGS. 1-6 and like numerals have been used to indicate like parts.
[0037] In the latch 100 , the roller mount assembly 18 is attached to the channel member 32 through adjustable side flanges 61 . The side flanges 61 are attached to a winch plate 64 and are pivotally movable about a pivot pin 63 located at the end of the winch plate 64 . The winch plate 64 is welded to the mounting plate 37 and is further supported in position by means of support 65 . The degree of movement of the adjustable side flanges 61 is constrained by arcuate slots that receive pins 66 .
[0038] The relative angle at which the roller mount assembly 18 is presented to a boat hull is variable thereby allowing the latch 100 to be used with a variety of boat hull angles.
[0039] Further advantages and improvements may be made to the present invention without deviating from its scope. In particular the angle and position at which the latch assembly is mounted and the dimensions of the channel member are able to varies to accommodate differing boat geometries. Thus, although the invention has been shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope and spirit of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus.
[0040] In any claims that follow and in the summary of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprising” is used in the sense of “including”, i.e. the features specified may be associated with further features in various embodiments of the invention. | A boat latch for securing a boat or the like having a bow ring to a trailer including,
a roller mount assembly having a roller adapted to guide the bow of a boat into position said roller being attached to an upper end of a kicker arm, said kicker arm being pivotally mounted in a housing; a locking pin assembly movable between a cocked and a free position; whereby as a boat is guided into position against the roller mount assembly a rotation of said kicker arm may be induced by pressure exerted against the roller by a boat to thereby activate the locking pin at a position wherein the locking pin engages the bow ring to thereby secure the boat to the trailer. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/185,802, filed on Jun. 10, 2010, and entitled “Method for Assessing Vascular Disease by Quantitatively Measuring Vaso Vasorum.”
BACKGROUND OF THE INVENTION
[0002] The field of the invention is ultrasound imaging methods and systems. More particularly, the invention relates to employing ultrasound to assess cardiac disease by quantitatively measuring vaso vasorum.
[0003] There are a number of modes in which ultrasound can be used to produce images of objects. The ultrasound transmitter may be placed on one side of the object and the sound transmitted through the object to the ultrasound receiver placed on the other side (“transmission” mode). With transmission mode methods, an image may be produced in which the brightness of each pixel is a function of the amplitude of the ultrasound that reaches the receiver (“attenuation” mode), or the brightness of each pixel is a function of the time required for the sound to reach the receiver (“time-of-flight”, or “speed of sound” mode). In the alternative, the receiver may be positioned on the same side of the object as the transmitter and an image may be produced in which the brightness of each pixel is a function of the amplitude or time-of-flight of the ultrasound reflected from the object back to the receiver (“refraction”, “backscatter”, or “echo” mode).
[0004] There are a number of well known backscatter methods for acquiring ultrasound data. In the so-called “A-scan” method, an ultrasound pulse is directed into the object by the transducer and the amplitude of the reflected sound is recorded over a period of time. The amplitude of the echo signal is proportional to the scattering strength of the refractors in the object and the time delay is proportional to the range of the refractors from the transducer. In the so-called “B-scan” method, the transducer transmits a series of ultrasonic pulses as it is scanned across the object along a single axis of motion. The resulting echo signals are recorded as with the A-scan method and their amplitude is used to modulate the brightness of pixels on a display. The location of the transducer and the time delay of the received echo signals locates the pixels to be illuminated. With the B-scan method, enough data are acquired from which a two-dimensional image of the refractors can be reconstructed. Rather than physically moving the transducer over the subject to perform a scan it is more common to employ an array of transducer elements and electronically move an ultrasonic beam over a region in the subject.
[0005] Ultrasonic transducers for medical applications are constructed from one or more piezoelectric elements sandwiched between a pair of electrodes. Such piezoelectric elements are typically constructed of lead zirconate titanate (“PZT”), polyvinylidene diflouride (“PVDF”), or PZT ceramic/polymer composite. The electrodes are connected to a voltage source, and when a voltage is applied, the piezoelectric elements change in size at a frequency corresponding to that of the applied voltage. When a voltage pulse is applied, the piezoelectric element emits an ultrasonic wave into the media to which it is coupled at the frequencies contained in the excitation pulse. Conversely, when an ultrasonic wave strikes the piezoelectric element, the element produces a corresponding voltage across its electrodes. Typically, the front of the element is covered with an acoustic matching layer that improves the coupling with the media in which the ultrasonic waves propagate. In addition, a backing material is disposed to the rear of the piezoelectric element to absorb ultrasonic waves that emerge from the back side of the element so that they do not interfere.
[0006] When used for ultrasound imaging, the transducer typically has a number of piezoelectric elements arranged in an array and driven with separate voltages (“apodizing”). By controlling the time delay (or phase) and amplitude of the applied voltages, the ultrasonic waves produced by the piezoelectric elements (“transmission mode”) combine to produce a net ultrasonic wave focused at a selected point. By controlling the time delay and amplitude of the applied voltages, this focal point can be moved in a plane to scan the subject.
[0007] The same principles apply when the transducer is employed to receive the reflected sound (“receiver mode”). That is, the voltages produced at the transducer elements in the array are summed together such that the net signal is indicative of the sound reflected from a single focal point in the subject. As with the transmission mode, this focused reception of the ultrasonic energy is achieved by imparting separate time delay (and/or phase shifts) and gains to the echo signal received by each transducer array element.
[0008] Doppler systems employ an ultrasonic beam to measure the velocity of moving reflectors, such as flowing blood cells. Blood velocity is detected by measuring the Doppler shifts in frequency imparted to ultrasound by reflection from moving red blood cells. Accuracy in detecting the Doppler shift at a particular point in the bloodstream depends on defining a small sample volume at the required location and then processing the echoes to extract the Doppler shifted frequencies.
[0009] A Doppler system is incorporated in a real time scanning imaging system. The system provides electronic steering and focusing of a single acoustic beam and enables small volumes to be illuminated anywhere in the field of view of the instrument, whose locations can be visually identified on a two-dimensional B-scan image. A Fourier transform processor faithfully computes the Doppler spectrum backscattered from the sampled volumes, and by averaging the spectral components the mean frequency shift can be obtained. Typically the calculated blood velocity is used to color code pixels in the B-scan image.
[0010] In areas of injured endothelial lining, tiny blood vessels referred to as vaso vasorum are formed to supply these areas. These inflamed areas are vulnerable to form plaque. It would therefore be desirable to have a method for not only visualizing the presence of vaso vasorum, but to quantify their presence and effect.
SUMMARY OF THE INVENTION
[0011] The present invention is directed to a method for measuring the risk a tissue of interest has for developing vascular disease. More particularly, the present invention is a method for quantifying the extent of vaso vasorum with contrast enhanced ultrasound and correlating that quantitative value to the risk for vascular disease. An ultrasound contrast agent is administered to a subject and images are obtained using an imaging method that identifies the uptake of the contrast agent by tissues. The amount of uptake is measured and the corresponding signal intensity change correlated with the amount of vaso vasorum present. Additionally, deformations of the vasculature are measured from the series of ultrasound images and this information is coupled with the quantification of the vaso vasorum to determine a risk index indicative of a subject's risk to vascular disease.
[0012] The foregoing and other aspects and advantages of the invention will appear from the following description. In the description, reference is made to the accompanying drawings which form a part hereof, and in which there is shown by way of illustration a preferred embodiment of the invention. Such embodiment does not necessarily represent the full scope of the invention, however, and reference is made therefore to the claims and herein for interpreting the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a block diagram of an ultrasonic imaging system that employs the present invention;
[0014] FIG. 2 is a block diagram of a transmitter which forms part of the ultrasonic imaging system of FIG. 1 ;
[0015] FIG. 3 is a block diagram of a receiver which forms part of the ultrasonic imaging system of FIG. 1 ; and
[0016] FIG. 4 is a flowchart setting forth the steps of an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Referring particularly to FIG. 1 , an ultrasonic imaging system includes a transducer array 100 comprised of a plurality of separately driven elements 102 which each produce a burst of ultrasonic energy when energized by a pulse produced by a transmitter 104 . The ultrasonic energy reflected back to the transducer array 100 from the subject under study is converted to an electrical signal by each transducer element 102 and applied separately to a receiver 106 through a set of switches 108 . The transmitter 104 , receiver 106 , and the switches 108 are operated under the control of a digital controller 110 responsive to the commands input by the human operator. A complete scan is performed by acquiring a series of echoes in which the switches 108 are set to their transmit position, the transmitter 104 is gated on momentarily to energize each transducer element 102 , the switches 108 are then set to their receive position, and the subsequent echo signals produced by each transducer element 102 are applied to the receiver 106 . The separate echo signals from each transducer element 102 are combined in the receiver 106 to produce a single echo signal which is employed to produce a line in an image on a display system 112 .
[0018] The transmitter 104 drives the transducer array 100 such that the ultrasonic energy produced is directed, or steered, in a beam. A B-scan can therefore be performed by moving this beam through a set of angles from point-to-point rather than physically moving the transducer array 100 . To accomplish this the transmitter 104 imparts a time delay, T, to the respective pulses 116 that are applied to successive transducer elements 102 . If the time delay is zero T i =0, all the transducer elements 102 are energized simultaneously and the resulting ultrasonic beam is directed along an axis 118 normal to the transducer face and originating from the center of the transducer array 100 . As the time delay, T i , is increased, the ultrasonic beam is directed downward from the central axis 118 by an angle, θ. The relationship between the time delay increment, T i , added successively to each i th signal from one end of the transducer array (i=1) to the other end (i=n) is given by the following relationship:
[0000]
T
i
=
(
i
-
(
n
-
1
)
2
)
(
S
sin
(
θ
)
c
)
+
(
i
-
(
n
-
1
)
2
)
2
(
S
2
cos
(
2
θ
)
2
Rc
)
+
T
0
;
Eqn
.
(
1
)
[0019] where S is an equal spacing between centers of adjacent transducer elements 102 , c is the velocity of sound in the object under study, R is a range at which the transmit beam is to be focused, and T 0 is a delay offset that insures that all calculated values, T i , are positive values.
[0020] The first term in this expression steers the beam in the desired angle, θ, and the second is employed when the transmitted beam is to be focused at a fixed range. A sector scan is performed by progressively changing the time delays, T i , in successive excitations. The angle, θ, is thus changed in increments to steer the transmitted beam in a succession of directions. When the direction of the beam is above the central axis 118 , the timing of the pulses 116 is reversed, but the above formula still applies.
[0021] Referring still to FIG. 1 , the echo signals produced by each burst of ultrasonic energy emanate from reflecting objects located at successive positions, R, along the ultrasonic beam. These are sensed separately by each segment 102 of the transducer array 100 and a sample of the magnitude of the echo signal at a particular point in time represents the amount of reflection occurring at a specific range, R. Due to the differences in the propagation paths between a focal point, P, and each transducer element 102 , however, these echo signals will not occur simultaneously and their amplitudes will not be equal. The function of the receiver 106 is to amplify and demodulate these separate echo signals, impart the proper time delay to each and sum them together to provide a single echo signal which accurately indicates the total ultrasonic energy reflected from each focal point, P, located at successive ranges, R, along the ultrasonic beam oriented at the angle, θ.
[0022] Under the direction of the digital controller 110 , the receiver 106 provides delays during the scan such that the steering of the receiver 106 tracks with the direction of the beam steered by the transmitter 104 and it samples the echo signals at a succession of ranges and provides the proper delays to dynamically focus at points, P, along the beam. Thus, each emission of an ultrasonic pulse results in the acquisition of a series of data points which represent the amount of reflected sound from a corresponding series of points, P, located along the ultrasonic beam.
[0023] Referring particularly to FIG. 2 , the transmitter 104 includes a set of channel pulse code memories which are indicated collectively at 200 . Each pulse code memory 200 stores a bit pattern 202 that determines the frequency of the ultrasonic pulse 204 that is to be produced. This bit pattern is read out of each pulse code memory 200 by a master clock and applied to a driver 206 which amplifies the signal to a power level suitable for driving the transducer 100 . In the example shown in FIG. 2 , the bit pattern is a sequence of four “1” bits alternated with four “0” bits to produce a 5 megahertz (“MHz”) ultrasonic pulse 204 . The transducer elements 102 to which these ultrasonic pulses 204 are applied respond by producing ultrasonic energy.
[0024] As indicated above, to steer the transmitted beam of the ultrasonic energy in the desired manner, the pulses 204 for each of the N channels must be produced and delayed by the proper amount. These delays are provided by a transmit control 208 which receives control signals from the digital controller 110 . When the control signal is received, the transmit control 208 gates a clock signal through to the first transmit channel 200 . At each successive delay time interval thereafter, the clock signal is gated through to the next channel pulse code memory 200 until all the channels to be energized are producing their ultrasonic pulses 204 . Each transmit channel 200 is reset after its entire bit pattern 202 has been transmitted and the transmitter 104 then waits for the next control signal from the digital controller 110 . By operating the transmitter 104 in this manner, ultrasonic energy can be focused on a focal point, P, when practicing the herein described method. This focal point can be steered electronically with the appropriate changes to the timing delays provided by the transmit control 208 . The term “focal point,” as referred to herein, includes not only a single point object in the usual sense, but also a general region-of-interest to which ultrasound energy is delivered in a substantially focused manner.
[0025] Referring particularly to FIG. 3 , the receiver 106 is comprised of three sections: a time-gain control (“TGC”) section 300 , a beam forming section 302 , and a mid processor 304 . The time-gain control section 300 includes an amplifier 306 for each of the N receiver channels and a time-gain control circuit 308 . The input of each amplifier 306 is connected to a respective one of the transducer elements 102 to receive and amplify the echo signal which it receives. The amount of amplification provided by the amplifiers 306 is controlled through a control line 310 that is driven by the time-gain control circuit 308 . As is well known in the art, as the range of the echo signal increases, its amplitude is diminished. As a result, unless the echo signal emanating from more distant reflectors is amplified more than the echo signal from nearby reflectors, the brightness of the image diminishes rapidly as a function of range, R. This amplification is controlled by the operator who manually sets TGC linear potentiometers 312 to values which provide a relatively uniform brightness over the entire range of the scan. The time interval over which the echo signal is acquired determines the range from which it emanates, and this time interval is divided into segments by the TGC control circuit 308 . The settings of the potentiometers are employed to set the gain of the amplifiers 306 during each of the respective time intervals so that the echo signal is amplified in ever increasing amounts over the acquisition time interval.
[0026] The beam forming section 302 of the receiver 106 includes N separate receiver channels 314 . Each receiver channel 314 receives the analog echo signal from one of the TGC amplifiers 306 at an input 316 , and it produces a stream of digitized output values on an I bus 318 and a Q bus 320 . Each of these I and Q values represents a sample of the echo signal envelope at a specific range, R. These samples have been delayed in the manner described above such that when they are summed at summing points 322 and 324 with the I and Q samples from each of the other receiver channels 314 , they indicate the magnitude and phase of the echo signal reflected from a point, P, located at range, R, on the ultrasonic beam.
[0027] Referring still to FIG. 3 , the mid processor section 304 receives the beam samples from the summing points 322 and 324 . The I and Q values of each beam sample is a digital number which represents the in-phase and quadrature components of the magnitude of the reflected sound from a point, P. The mid processor 304 can perform a variety of calculations on these beam samples, where choice is determined by the type of image to be reconstructed. For example, if a conventional magnitude image is to be produced, a detection processor indicated at 326 is implemented in which a digital magnitude, M, is calculated from each beam sample according to:
[0000] M =√{square root over (I 2 +Q 2 )} Eqn. (2);
[0028] and output at 120 ( FIGS. 1 and 3 ).
[0029] The detection processor 326 may also implement correction methods that, for example, examine the received beam samples and calculate corrective values that can be used in subsequent measurements by the transmitter 104 and receiver 106 to improve beam focusing and steering. Such corrections are necessary, for example, to account for the non-homogeneity of the media through which the sound from each transducer element travels during a scan.
[0030] The mid processor may also include a Doppler processor 328 . Such Doppler processors 328 often employ the phase information, φ, contained in each beam sample to determine the velocity of reflecting objects along the direction of the beam (i.e., direction from the transducer 100 ), where:
[0000]
ϕ
=
tan
-
1
(
I
Q
)
.
Eqn
.
(
3
)
[0031] The mid processor 304 may also include a correlation flow processor 330 that, for example, measures the motion of reflectors by following the shift in their position between successive ultrasonic pulse measurements.
[0032] Referring particularly now to FIG. 4 , a method for quantitatively measuring vaso vasorum, and thereby assessing vascular disease, in accordance with the present invention begins with the administration of an ultrasound contrast agent to a subject, as indicated at step 400 . Exemplary ultrasound contrast agents include those with the trade names SonoVue® (Bracco Diagnostics, Princeton, N.J.), Definity® (Lantheus Medical Imaging, North Billerica, Mass.), Optison (GE Healthcare, Waukesha, Wis.), and Imagent® (IMCOR Pharmaceutical Co., San Diego, Calif.). After the contrast agent has been administered to the subject, a series of image frames are acquired, as indicated at step 402 . The images acquired discriminate between the contrast agent and the background tissues. For example, a contrast pulse sequencing method is employed in which background tissue is separable from the contrast agent by way of simultaneously processing received signals from a plurality of transmitted pulses. The phase and amplitude modulation of each pulse is varied so that the interaction of the pulses with the contrast agent results in a response that is separable from background tissues. An exemplary imaging method of this kind is available under the trade name Cadence™ contrast pulse sequencing (Siemens Medical Solutions USA, Inc., Mountain View, Calif.).
[0033] From the acquired series of image frames, a perfusion rate of the contrast agent into the surrounding vasculature is determined at step 404 . The rate of perfusion of the contrast agent into the surrounding tissues provides a quantitative measure of the presence of vaso vasorum in the vessel. Where an increase in the perfusion of the contrast agent into the vascular wall occurs, an increase in signal intensity is present in the resulting images. The degree of perfusion of the contrast agent into the vascular wall is representative of the presence of vaso vasorum. To calculate the perfusion rate, the change in image intensity over the series of acquired images is analyzed. The signal intensity change in a selected region of interest is fit on a voxel-by-voxel basis to the following signal model:
[0000] A+B(1−e −kt ) Eqn. (4);
[0034] where A is constant indicative of the peak image intensity of contrast agent uptake, B is a constant indicative of the perfusion rate, k is a constant, and t is the time at which a given image frame was acquired. The constant B is calculated from the logarithm of the measured signal intensity change. It is contemplated that values of the constant, B, greater than 0.50 indicate the presence of vaso vasorum in the blood vessel of interest. It is also contemplated that the peak image intensity value, A, can be utilized to determine the presence of vaso vasorum, in as much as larger peak values are likely representative of the presence of more vaso vasorum in the vessel wall, which in turn provide a larger uptake of the contrast agent.
[0035] The acquired series of image frames are then also analyzed using a tracking technique that measures deformations in the vessel wall, as indicated at step 406 . An exemplary method of this kind is available under the trade name Velocity Vector Imaging™ (Siemens Medical Solutions USA, Inc., Mountain View, Calif.). Using a motion tracking method, such as the one provided by Velocity Vector Imaging™, radial deformations and rotations in a vessel wall are determined. Additionally, longitudinal and cross-sectional blood flow velocities through the blood vessel of interest can be calculated and utilized to assess the risk for vascular disease. This information, along with the perfusion rate calculated previously, is utilized to produce an index value, as indicated at step 408 . The index value indicates those tissues of interest that are at risk for a particular vascular disease.
[0036] After the index value has been produced, it is reported to the system operator, ultrasound technologist, clinician, or other healthcare professional, as indicated at step 410 . For example, an index map is produced, in which voxel values in the index map correspond to the index value calculated for the corresponding voxel location in the acquired series of image frames. An exemplary index map includes a discontinuous color coding scheme that indicates those regions where vaso vasorum are present and the degree of vulnerability for those regions to develop vascular disease. For example, an index value in the 75-100 percentile range is coded as red, 50-75 percentile range is coded as orange, 25-50 percentile range is coded as yellow, and 0-25 percentile range is coded as blue. By way of this example, those regions coded as red indicate areas at very high risk for vascular disease, while those coded as orange are at high risk, those coded as yellow are areas at moderate risk, and those coded as blue are at low risk. Alternatively, when the index values include values in the range identified as “risk”, a report can be produced indicating that the subject is at risk for particular a vascular disease.
[0037] Additionally, the quantified presence of vaso vasorum provided by the calculated perfusion rate in the lumen of the blood vessel can be utilized alone to assess the risk of the patient to developing vascular disease. For example, different threshold values of perfusion rate can be used to identify different risk groups. By way of example, the following ranges of values for the constant, B, can be used: 0-0.50, low risk; 0.50-5.0, higher risk; and greater than 5.0, even higher risk. Furthermore, this risk assessment can be supplemented with information regarding the deformation of the blood vessel wall. For instance, it is contemplated that the more cross-sectional rotational or radial deformation present in the vessel wall, the more likely the patient is at risk for developing vascular disease. The peak uptake of the contrast agent into the lumen of the blood vessel can also be utilized to assess the risk of the patient. For example, it is contemplated that a patient having a large uptake in contrast agent is more likely to have vaso vasorum present than a patient with less uptake.
[0038] The present invention has been described in terms of one or more preferred embodiments, and it should be appreciated that many equivalents, alternatives, variations, and modifications, aside from those expressly stated, are possible and within the scope of the invention. | A method and system for quantifying the extent of vaso vasorum with contrast enhanced ultrasound and correlating that quantitative value to the risk for vascular disease is provided. An ultrasound contrast agent is administered to a subject and images are obtained using an imaging method that identifies the uptake of the contrast agent by tissues. The amount of uptake is measured and the corresponding signal intensity change correlated with the amount of vaso vasorum present. Additionally, deformations of the vasculature are measured from the series of ultrasound images and this information is coupled with the quantification of the vaso vasorum to determine a risk index indicative of a subject's risk to vascular disease. | 0 |
FIELD OF THE INVENTION
The present invention relates to a swimming toy. More specifically, this invention concerns a battery-powered toy in the form of a turtle for use in water such as in a swimming pool.
BACKGROUND AND OBJECTS OF THE INVENTION
Toys, which resemble animals and are capable of moving themselves along the land or in water, are well known. Such toys of the prior art tend to be either very limited in their function, or include complicated mechanisms and circuits for providing a variety of functions. For instance, the speed at which the toy propels itself is generally fixed or may require an expensive multi-speed motor. Such toys of the prior art tend to move in a straight line, which limits their usefulness in a defined area such as a swimming pool. Some toys are adapted to move in a circular pattern, but those which are adjustable to move in either a straight line or a circular pattern use either a complicated steering mechanism or a steering rudder to accomplish this function. Such mechanisms tend to be expensive and prone to fail, while such rudders are unnatural appendages when integrated into an animal shape such as a turtle. Thus, either the toy is more expensive to manufacture than the marketplace will tolerate, or the toy performance is impaired and, after a very short time, a child becomes bored with his or her toy and abandons it.
It is therefore an object of the present invention to provide an improved toy, which is inexpensive to manufacture, yet which is more useful and less complicated than those of the prior art.
It is a further object to provide a more natural appearance and movement, according to the animal being simulated.
It is a further object to provide a toy turtle, whose naturally shaped and proportioned flippers move as do a real turtle's, while being adjustable for simultaneously allowing the turtles swimming speed and direction to be controlled according to the environment in which it is used.
These objects are attained according to the present invention in a toy comprising a sea turtle shape whose front flippers are driven in a natural motion by a battery-operated motor to propel the turtle through the water, and whose rear flippers are manually positionable to steer the turtle and/or to regulate the turtle's swimming speed by increasing or reducing drag as the turtle swims through the water.
SUMMARY OF THE INVENTION
In accordance with the present invention, a toy turtle is provided which has upper and lower shell portions, which form a body. A head, a tail, front right and left flippers, and rear right and left flippers extend from the body. A battery driven gear motor within the body causes linkage in the body to drive the front flippers back and forth, propelling the turtle through the water, as do a real sea turtle's, for swimming. The rear flippers are positionable by the user to act either as a rudder, controlling the direction in which the turtle swims when the flippers are positioned asymmetrically, or to control the turtle's swimming speed by increasing or reducing drag when the flippers are positioned symmetrically.
According to another feature of the invention, a blow-molded float is contoured to extend into voids within the body and provide buoyancy so that the turtle floats as it swims.
It is anticipated by the inventor that the mechanism and system employed herein could alternatively be adapted for use in other animal shapes, such as say a crocodilian shape, a salamander, or such.
Besides flippers, other such appendages may be used within the spirit of the invention, such as fins, wings, or limbs, provided that the appendages serve to propel the animal through the water when driven by the motor.
The toy according to the present invention is expected to have a long-lasting appeal for a youngster, as it does more than simply paddle along in the water. Furthermore, such a toy can be produced at relatively low cost and should have a long service life, due to its simplicity and minimal number of components.
The features which are considered novel and most vital to the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, will be best understood from the following description of the preferred embodiment, when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top perspective view of a toy turtle according to the preferred embodiment of the invention;
FIG. 2 is a top view of the toy turtle of FIG. 1;
FIG. 3 is a bottom view of the toy turtle of FIG. 1;
FIG. 4 is a bottom view of the toy turtle of FIG. 1, with the bottom shell portion and float removed and the front flippers in their most forward position;
FIG. 5 is a bottom view of the toy turtle of FIG. 1, with the bottom shell portion and float removed and the front flippers in their most rearward position;
FIG. 6 is a partial bottom view of the rear end of the toy turtle of FIG. 1, with the rear flippers asymmetrically positioned for rightward turning while swimming;
FIG. 7 is a partial bottom view of the rear end of the toy turtle of FIG. 1, with the rear flippers asymmetrically positioned for leftward turning while swimming; and
FIG. 8 is a partial exploded view of the front end of the toy turtle of FIG. 1, showing the swimming mechanism and front flippers in the top shell portion.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1-8 show the preferred embodiment of the present invention wherein a toy in the form of sea turtle 100 is provided, having upper shell portion 102 , lower shell portion 104 , and appendages including head 106 , tail 108 , front right flipper 112 , front left flipper 114 , rear right flipper 116 , and rear left flipper 118 . It should be noted, especially since several of the drawings are bottom views, that the terms “left” and “right” refer to the turtle's left and right sides, not necessarily to the left and right sides of the drawings.
The upper and lower shell portions are held together by fasteners, glue, and or any other such method, to form hollow body 122 and to capture the appendages therebetween.
Also captured with the hollow body 122 are gear motor 124 , battery housing 126 , switch 128 , and blow-molded float 130 . A typical household battery (not shown) is positioned with the hollow interior of battery housing 126 through opening 132 in lower shell portion 104 , and then sealingly encased by battery cover 134 , which is removably secured to lower shell portion 104 by fasteners 136 . Wiring 138 connects gear motor 124 to the battery through switch 128 , such that the motor is energized when the switch is in its “on” position and is de-energized when the switch is in its “off” position. All electrical components, including the battery and its related connectors, switch 128 , gear motor 124 , and wiring 138 , are sufficiently protected with appropriate sealants and gaskets to prevent wetting when turtle 100 is submerged in water.
All of the afore-listed flippers are loosely captured by the shell portions 102 and 104 in a fashion that allows some fore/aft pivoting relative to body 122 . Front right flipper 112 includes vertical hole 142 that loosely surrounds vertical pin 144 of upper shell portion 102 to allow the flipper to pivot horizontally in forward and rearward directions about the axis of the pin. Front left flipper 114 includes vertical hole 146 that loosely surrounds vertical pin 148 of upper shell portion 102 to allow this flipper to pivot horizontally in forward and rearward directions about the axis of this pin. Rear right flipper 116 includes vertical hole 152 that loosely surrounds vertical pin 154 of upper shell portion 102 to allow this flipper to pivot horizontally in forward and rearward directions about the axis of this pin. And rear left flipper 118 includes vertical hole 156 which loosely surrounds vertical pin 158 of upper shell portion 102 to allow this flipper to pivot horizontally in forward and rearward directions about the axis of this pin.
When motor 124 is energized, eccentric 162 rotates such that vertical pin 164 revolves in a circular and clockwise motion.
Front left flipper 144 includes longitudinal extension 166 , having vertical pin 168 extending downwardly there-from.
Front right flipper 122 includes longitudinal extension 172 , having there-through slot 174 for loosely receiving pin 164 and also having there-through slot 176 for loosely receiving pin 168 .
As should be best appreciated from FIGS. 4, 5 , and 8 , the revolution of pin 164 within slot 174 forces extension 172 to move in a cyclic fore/aft motion, thereby causing front right flipper 112 to pivot cyclically in a fore/aft motion about pin 144 . This cyclic fore/aft motion of extension 172 , and therefore of its slot 174 , additionally forces pin 168 , and therefore longitudinal extension 166 of front left flipper 114 , to move in a similar cyclic fore/aft motion, thereby causing front left flipper 114 to pivot cyclically in a fore/aft motion about pin 148 , in phase with the motion of front right flipper 112 . The front flippers are both hydro-dynamically shaped to provide less drag when moving forward in the water than when moving backward in the water. This fore/aft motion of the flippers, combined with such a forward drag advantage, efficiently propels the turtle forward in the water.
Hollow blow-molded float 130 is filled with air to offset the weight density of the other components and thereby provide buoyancy to allow the turtle to swim at the water surface. Alternatively, some or all of the components of the toy could be made of material that is less dense than water, or air could be trapped be the assembling together of the upper and lower shell portions, to provide the same buoyancy.
Each of rear flippers 116 and 118 includes extension 178 R and 178 L, including ratcheting indentations 182 R and 182 L for being selectively engaged by vertical pins 184 R or 182 L that extend from upper shell portion 102 . This allows the flippers to be pivoted into a plurality of distinct for/aft positions. As rear right flipper 116 is forcibly pivoted about pin 154 by the user, pin 184 R firmly engages one of ratcheting indentations 182 R to hold the flipper in the selected position. As rear left flipper 118 is forcibly pivoted about pin 158 by the user, pin 184 L firmly engages one of ratcheting indentations 182 L to hold this flipper in the selected position.
Pivoting of both rear flippers 116 and 118 fully backward minimizes drag as the turtle swims through the water, and thereby allows the turtle to swim fastest. As the flippers are incrementally and symmetrically forced into more forward positions, the swimming is slowed by increasing drag as the turtle moves through the water.
Swimming direction can also be controlled by the asymmetrical positioning of the rear flippers. This is best appreciated by viewing FIGS. 6 and 7. For the sharpest rightward turning, rear right flipper 116 is pivoted into its most forward position for maximum drag on the turtle's right side, while rear left flipper 118 is pivoted into its most rearward position for minimum drag on the turtle's left side, as shown in FIG. 6 . This will cause the turtle's swimming pattern to be clockwise in the tightest circle. Clockwise patterns in incrementally larger circles at incrementally faster speeds can be accomplished by pivoting only the rear right flipper 116 incrementally rearward, or clockwise patterns in incrementally larger circles at incrementally slower speeds can be accomplished by pivoting only the rear left flipper 118 incrementally forward.
Alternatively, For the sharpest leftward turning, rear left flipper 118 is pivoted into its most forward position for maximum drag on the turtle's left side, while rear right flipper 116 is pivoted into its most rearward position for minimum drag on the turtle's right side, as shown in FIG. 7 . This will cause the turtle's swimming pattern to be counter-clockwise in the tightest circle. Counter-clockwise patterns in incrementally larger circles at incrementally faster speeds can be accomplished by pivoting only the rear left flipper 118 incrementally rearward, or counter-clockwise patterns in incrementally larger circles at incrementally slower speeds can be accomplished by pivoting only the rear right flipper 116 incrementally forward.
As can be appreciated, twenty-five distinct swimming speeds and swimming patterns can hereby be realized through the repositioning of only two components and without the need for an expensive multi-speed motor and multi-position switch.
The foregoing description and drawings provide only the preferred of many possible embodiments of the inventions, and are not intended to limit the invention. Many obvious alterations could be made without departing in any way from the spirit of the present invention. It is therefore intended that only the following claims should limit the invention. | A toy turtle is provided with a head, a tail, front right and left flippers, and rear right and left flippers extending from a body. A battery driven gear motor within the body causes linkage in the body to drive the front flippers back and forth, propelling the turtle through the water. The rear flippers are selectively positionable by the user to act in combination either as a rudder, controlling the direction in which the turtle swims when the flippers are positioned asymmetrically, or to control the turtle's swimming speed by increasing or reducing drag when the flippers are positioned symmetrically. | 0 |
BACKGROUND OF THE INVENTION
This invention relates to a control valve for hydraulic fluid. The control valve may be for directly controlling a hydraulic device (e.g. a piston and cylinder unit) or for indirectly controlling a hydraulic device, and hence functioning as a so called command control valve, by controlling flow of hydraulic fluid in a pilot hydraulic circuit which in turn effects operation of a main valve controlling a main hydraulic circuit connected to the hydraulic device.
Such control valves--for direct or indirect control--are used extensively for instance in hydraulically powered, self-advancing mine roof supports, which are located side-by-side along the goaf side of an armoured, scraper chain conveyor extending along a mineral face, the conveyor being built up to its desired length by a plurality of line pans of unit length, secured together end-to-end, in articulated manner.
A commonly employed command control valve is of a rotary kind. However, after the manual actuation of a rotary command control valve, by the operator rotating the hand lever to achieve the mode of operation required e.g. retraction of a roof beam from the mine roof, extension of the advancing ram(s), retraction of the advancing ram(s), or setting of the roof beam against the mine roof, it is necessary for the operator to remember to rotate the hand lever to a neutral position, if the valve is to be made ineffective. Understandably, return of the hand lever to its neutral position cannot be guaranteed and on occasion movement of hydraulic hoses, falling of debris etc., has inadvertently actuated a rotary command control valve, with consequent operation of the main valve and hence unexpected movement of the mine roof support(s) in question, which is usually extremely hazardous to any personnel in the vicinity. Furthermore, a rotary valve can only be made to effect one command at any one time. For direct control of a mine roof support, the valve is used for the so called "in-chock" operations, such as advancing or retracting a face sprag mechanism and/or a forepoling beam (as are commonly provided on roof supports) of the roof support in which the valve is located.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a control valve particularly for effecting control of a hydraulic circuit comprising:
at least one valve arrangement located in a first valve body which is provided with a hydraulic fluid supply port, a hydraulic fluid exhaust port, and a hydraulic fluid delivery port, the valve arrangement normally being biassed to a position in which fluid flow connection is made between the delivery port and the exhaust port, and the supply port is closed; and the valve arrangement being manually displaceable in a first direction, to cause firstly closure of the connection between the delivery port and the exhaust port and secondly, upon further displacement, opening of a fluid flow connection between the delivery port and the supply port; and
a valve arrangement located in a second valve body which is provided with an inlet port connectable to a source of hydraulic fluid, a hydraulic fluid exhaust port, and a hydraulic fluid delivery port to deliver fluid to the supply port of the or each first valve body, the valve arrangement normally being biassed to a position in which fluid flow connection is made between the delivery port and the exhaust port, and the inlet port is closed, and manually displaceable in a second direction, which is opposite to said first direction, to cause firstly closure of the connection between the delivery port and the exhaust port, and secondly, upon further displacement, opening a fluid flow connection between the inlet port and the delivery port, to make fluid available to the supply port of the or each first valve body, whereby a hydraulic pressure is only transmitted from the control valve when there is activated not only the first valve body, or a selected one or more of the first valve bodies but also the second valve body.
Thus, the control valve in accordance with the invention does not require the operator to remember to put the valve into a safe, neutral mode after actuation, for the activated first valve body or bodies and/or second valve body automatically achieve(s) this upon being released from the manual displacement effected by the operator, due to this biassing, and furthermore, by either a first or the second valve body automatically achieving this neutral mode, the valve is doubly protected. Thus, even if a first valve body is activated, then unless the second valve body is also activated whilst the first valve body is still being activated, no pressure fluid is made available to the fluid supply port of the first valve body. Thus, whilst it is conceivable that movement of hydraulic hoses, falling of debris etc. might inadvertently activate the first valve body or bodies, or the second valve body, it is highly improbable that hoses or debris could activate both the first valve body or bodies and the second valve body simultaneously and in opposite directions, for as indicated above activation of both, and in opposite directions, is necessary in order to neutralise the double connection to exhaust before delivery of hydraulic pressure can be effected.
The valve arrangement of the or each first valve body may be manually displaceable via an individual piano key type, "function" lever, which conveniently depend(s) downwardly from the valve body, while the valve arrangement of the second valve body may be manually displaceable via a lever or bar of length approximately to that of the control valve, and also downwardly depending if the function lever(s) of first valve body or bodies is or are so arranged. Although the first valve body or bodies and the second valve body may form part of a common valve block, preferably, the or each first valve body, and the second valve body, are each constituted by a standard, self-contained valve body to provide a modular construction, the required number of valve body modules being assembled together on a manifold, to constitute a multi-module valve body, the the second valve body module being mounted in the reverse direction to the module(s) of the first valve body or bodies. Similarly, the manifold itself may be a one piece element, or alternatively each valve body module may be attached to its own manifold module to form a valve/manifold unit, the required number of units being sandwiched together to provide a control valve having the required number of functions. With either a one piece manifold or modular manifold, delivery of fluid from the delivery port of the second valve member is into a port extending along the manifold and connectable to the supply port of the supply port of the or each first valve body module. In detail, the modules of the valve body or manifold may be bolted together, with interposed gaskets. Conveniently, biassing of the valve arrangements is by spring means.
In principle, the control valve may incorporate any number of first valve body modules, say six or eight, (and hence six or eight piano key type function levers) mounted in a first direction and a single, second valve body module, mounted in the reverse direction. Thus, the embodiment with six first valve modules would--in the case of controlling hydraulically powered, self-advancing mine roof supports--function as a command control valve, would be located in a first roof support, and would control pilot circuits in turn controlling a main control valve in roof supports adjacent each side of the one in which the command control valve is was located, and would thus provide the so called "adjacent control" whereby the operator, from the safety of a support set to the roof, in which the particular command control valve is located, is able to control three functions of a selected adjacent support, by actuation of a selected set of three function levers, the functions being (1) the retraction (from the mine roof) of the roof support, (2) the advance of the roof support, and (3) the re-setting of the roof support (to the mine roof).
In certain circumstances, particularly when the control valve is functioning as a command control valve, it is desireable to maintain pilot pressure in the pilot circuit after release of the selected function lever and/or the lever or bar of the second valve body, such a circumstance being where the conventionally provided advancing ram of the roof support is required to advance a line pan of the conveyor to which it is mechanically connected. Therefore, in accordance with a modified version of the embodiment of the invention comprising a plurality of modules and a manifold, a pressure retaining block, incorporating a valve, is interposed between the modules and the manifold, the block incorporating a spring-loaded, mechanically displaceable valve member, together with an actuator having a nose projecting from the block and adapted to engage an extension of a function lever. This arrangement may provide for manual cancellation of the locked-in pilot pressure signal, by manually returning the actuator lever to its non-active position, whereby the function lever extension displaces the actuator nose, the latter unseating the valve member to release the locked-in pilot pressure signal, or alternatively it may be arranged for automatic cancellation of the locked-in pilot pressure signal to be effected upon advance of the support.
Furthermore, with piano key type levers, it is quite possible for the operator to actuate more than one of these simultaneously, together with the lever or bar of the second valve body and hence to achieve output from the command control valve of multiple pilo pressure signals.
DESCRIPTION OF THE DRAWINGS
The invention will now be described in greater detail, by way of example with reference to the accompanying drawing, in which:
FIG. 1 is a front elevation of a control valve, of the command type, in accordance with the present invention;
FIG. 2 is a plan view of FIG. 1;
FIG. 3 is an end elevation of FIG. 1 in the direction of arrow A;
FIG. 4 is a section on the line IV--IV of FIG. 1;
FIG. 5 is a section on the line V--V of FIG. 2 showing the valve member in a non-activated position;
FIG. 6 is a sectional view through a known main control valve assembly controlled by pilot pressure signals from the command control valve of FIGS. 1 to 5; and
FIG. 7 is a sectional view through a second embodiment of control valve in accordance with the invention showing the valve member in a partially activated position.
DETAILED DESCRIPTION
Both the example of command control valve 1 illustrated in FIGS. 1 to 5 of the drawings and the example of control valve 1A illustrated in FIG. 7 of the drawings, are for installation in a mine roof support of the well known hydraulically powered, self-advancing kind. A plurality of such supports are located, in the well known manner, side-by-side along the goaf side of an armoured, scraper chain conveyor extending along the mineral face, the roof supports serving not only for their prime, roof supporting function, but also for advancing the individual, unit length line pans from which the conveyor is built up. The command control valve 1 in accordance with FIGS. 1 to 5 is intended for actuating, by pilot pressure signals, valve members of a main control valve assembly 2 exemplified in FIG. 6. A main control valve 2 assembly is likewise associated with each roof support and is connected to a mains pressure line, and a mains exhaust line, for activating the various hydraulic components, e.g. rams, chock legs etc., conventionally provided on a hydraulically powered mine roof support.
The example of command control valve 1 illustrated in FIGS. 1 to 5 of the drawings is intended for controlling, via the associated main control valve assembly 2, three functions of a roof support viz. "lower" (from the mine roof), "advance" (of the roof support towards a previously advanced line pan), and "re-set" (against the mine roof), and consequently the command control valve 1 comprises a one piece manifold block 3 provided, inter alia, with a fluid supply bore 4 connectable to a hydraulic pressure line (not shown) from a hydraulic pump, and an exhaust bore 5 connectable to a hydraulic exhaust line (not shown), a pilot pressure supply bore 6, an "advance" bore 7, a "lower" bore 8, and a "re-set" bore 9. The manifold block 3 carries six first valve body modules 10 each housing a first valve arrangement (to be described in detail later), and one second valve body module 11, identical to the modules 10 but disposed in the reverse direction to the valve modules 10, and housing a second valve arrangement (to be described in detail later), the valve modules 10 and 11 being bolted together, and to the manifold block 3, with interposed gaskets.
The command control valve 1 incorporates as many first modules 10 as are required for actuating the functions--three in the example illustrated--to be controlled by a main valve assemblies 2 which the command control valve 1 is hydraulically connected, with one set of three modules 10 being for controlling the function of an adjacent support located to one side of that support in which the command control valve 1 is located, and the other set of three modules 10 being for controlling the functions of the adjacent support to the other side.
With each module 10, the valve arrangement, comprises a valve spindle 12, having a first valve member 13 associated with a first valve seat 14 of a first valve chamber 15 in communication via a hydraulic fluid supply port 16 with the pilot pressure supply bore 6. The valve spindle 12 has an enlarged head 17 slidably located in an elongate aperture 18 extending coaxially with the longitudinal axis of the valve spindle 12 and provided in a closure plug 19 screwed into the module 10 with appropriate fluid seals 20 to close one end of the valve chamber 15. Also located in the aperture 18, between a closed end thereof, and the opposite face of the enlarged head 17, is a coil compression spring 21 by which the valve member 13 is normally biassed into engagement with its seat 14. Beyond the first valve member 13, the valve spindle 12 incorporates a reduced diameter portion 22 which terminates in a second, conical valve member 23 in a second valve chamber 24 which is in communication via a hydraulic fluid delivery port 25 with either one of bores 7, 8 or 9, and in FIG. 5, the delivery port 25 is illustrated as in communication with the "advance" bore 7. It follows that while ever the first valve member 13 is in engagement with its valve seat 14, no pilot pressure from bore 6, via port 16, the first valve chamber 15, the second valve chamber 24 and port 25 is available to achieve the selected function e.g. to provide a pilot pressure signal to the "advance" bore 7. Also located within the second valve chamber 24 is a second valve seat 26 provided at one end of a rod 27, the latter extending into a third valve chamber 28, and being hollow from the second valve seat 26 as far as a cross bore 29 in communication with the third valve chamber 28. The third valve chamber 28 is in communication via a hydraulic fluid exhaust port 30 with the exhaust bore 5. Hence in the non-activated valve position illustrated in FIG. 5, a fluid flow connection is made between the "advance" bore 7 and the "exhaust" bore 5 via the delivery port 25, the second valve chamber 24, the third valve chamber 28 and the exhaust port 30. The end of the rod 27 remote from the valve seat 26 is connected to a plunger 31 slidably housed within a plug 32, which also serves to close the third valve chamber 28, one end of the plunger 31 projecting from the plug 32. In the case of the modules 10, the plunger 31 is displaceable by a piano key type, "function" lever 33, pivotally attached to the module on a pivot pin 34, and urged away from its module by a wire spring 35. The function lever 33 also carries a legend plate 36 identifying the function associated with that module, while in the case of the module 11, there is provided a similar operating lever 37 which carries a longitudinal bar 38 approximating in length to that of the valve 1.
The module 11 is identical to the modules 10, but is mounted on the manifold 3 is a reverse direction, the module 11, as indicated in FIG. 4, having an inlet port 16A connected to the fluid supply bore 4, a delivery port 25A connected to the pilot pressure supply bore 6, and an exhaust port 30A connected to exhaust bore 5. Thus with pressure fluid supplied to the bore 4 of the manifold 3, pressure fluid cannot progress beyond the module 11 until the latter is activated. Thus, to provide hydraulic pressure to the pilot delivery bore 6, from the supply bore 4 via the module 11, the pilot delivery bore 6 being common to all fluid support ports 16 of the six modules 10, one of the six function levers 33 is depressed, but no pressure can be generated until the bar 38 is depressed, to actuate the module 11, to achieve again closure of the normally open connection of this module to its exhaust port and subsequent fluid connection between bore 4 and pilot delivery bore 6. It follows that upon release of either the selected function lever 33 or the bar 38, the module returns to a neutral position, with no pressure signal present in the pilot bore 6, because the latter is automatically connected to exhaust.
The known, main control valve assembly 2 illustrated in FIG. 6, requires no detailed description, but comprises basically spring loaded, hydraulically balanced, pilot pressure actuated, pressure and exhaust poppet valves 39 and 40 respectively. The valve assembly 2 further comprises a bore 41 connected to a left hand rear leg (of a three leg mine roof support), a bore 42 connected to a right hand rear leg, bore 43 connected to one of the left hand side set of three modules 10, a bore 44 connected to one of the right hand side set of three modules 10, and a yield valve 45.
The second embodiment of control valve 1A, which is illustrated in FIG. 7, would, if its presence were required for line pan advancing functions, be attached to one end of the valve 1 of FIGS. 1 to 5, with the manifold 3 thereof suitably extended. The control valve 1A incorporates a module 10 identical to that of FIGS. 1 to 5, but having an extension 46 on its function lever 33, while interposed between the module 10 and the manifold is a block 47 incorporating a spring loaded, check valve 48, which is mechanically displaceable against the action of its spring by a slidable actuator 49 having a nose 50 projecting from the block 47 and engaging the extension 46 of the function lever 33. Thus, after pressure delivery has been effected through port 25 and check valve 48 to pilot supply bore 6, pressure is held in the bore 6 by closure of the valve 48, after release of the function lever 33 and the bar 38, with pressure being released from the bore 6 by the check valve 48 becoming unseated, by displacement of the slidable actuator 49, either manually by operation of the function lever 33, whereby the extension 46 displaces the nose 49, or alternatively automatic release may be arranged, upon the support being advanced. | A control valve arrangement includes at least one first supply and exhaust valve, and a second supply and exhaust valve. The first and second valves are arranged in series and are manually operated with a single hand. The first valve is manually displaced in one direction, and the second valve is displaced in the opposite direction. | 8 |
RELATED APPLICATION
[0001] This application claims the benefit of priority from provisional patent application No. 61/750,994 filed on Jan. 10, 2013, the entirety of which is incorporated by reference,
FIELD OF INVENTION
[0002] The present arrangement provides for a system and method for exchanging advertisements and bids for rental properties between renters/buyers and property owners. More particularly, the present arrangement provides a system and method to support a binding arrangement for renter/buyers to issue a request and for property owners to bid on such request.
DESCRIPTION OF RELATED ART
[0003] Currently, the primary method for property owners seeking to rent one or more properties is to set up an advertisement or offer to rent one or more properties and then disseminate the advertisement through any one of several traditional avenues, including newspapers, brokers, and web-based advertising. Potential renters can then seek such properties and offer either the asking rent or make a lower counter offer as depicted in FIG. 1 .
[0004] However, with this arrangement there is no clear indication to a property owner how a particular potential renter is interacting with other properties they are seeking making it difficult to negotiate with the potential renter. For example, a property owner may receive a request to rent one of their properties for 10% less than their asking price. However, in existing systems, this same property owner does not know if the same bidder is also making offers to other property owners in the same neighborhood and how much those offers are for, particularly relative to the asking prices of those other owners. This makes it difficult for the property owner who received the 10% lower request to determine the existing market for theirs and other properties in the same geographic vicinity.
OBJECTS AND SUMMARY
[0005] The present arrangement is a unique and innovative “reverse-auction” arrangement, implemented for example through a website, where buyers can list their properties for rent as in the prior art systems. However, unlike the prior art, renters can select multiple properties, such as vacation or full time rentals, and issue a bid/price they want to pay (which may or may not be lower than the asking price) and then initiate a 24-hour binding reverse auction whereby the first of the several property owners that accepts the renter's offer ends the reverse auction and simultaneously accepts the contract as a binding rental contract.
[0006] In this context, the present arrangement acts as an intermediary in the otherwise fragmented real estate market for vacation and full time rentals by creating a live, real-time marketplace whereby multiple property owners selected by the renter (supply) compete for a fixed price set by the renter (demand). Such an overall dynamic is shown for example in FIG. 2 . This platform serves to eliminate the current inefficiencies that exist in the $400 B domestic market for vacation and full time rentals and allows the natural forces of supply and demand to better and more effectively drive any given transaction (vs. brokers or one-on-one discussions between owners and renters).
[0007] Furthermore, the present arrangement may be implemented as part of a collaborative consumption movement in the hospitality market, and may be used in other similar transactions beyond rental properties that currently utilizes a broker or middleman, including, but not limited to, travel offers, real estate sales, ticket sales, car rentals, etc . . .
[0008] The present arrangement benefits consumers by shifting the leverage that currently favors property owners who often play one prospective renter against the other to that of a more level playing field between one renter and multiple property owners.
[0009] In addition, the present arrangement incorporates multiple social networking tools to make the experience more transparent, i.e., viewing property owners and prospective renters' profiles on Facebook™ and Linkedin™ or other similar social media services.
[0010] In one embodiment, the present arrangement may be implemented for free to post and search, and charges the property owner and renter a service fee (e.g. 3% and 6%, respectively) only on successfully consummated transactions. This is a savings for example to vacation property owners who currently pay broker commissions of 10% or, in some cases, monthly fees to post on various websites and to full time rental property owners who pay broker commissions of one or two month's rent (8% or 16%).
[0011] The present arrangement also contemplates providing a savings to renters who currently pay service fees up to 50% higher to rent vacation properties on other websites and, depending on the market, are required to pay broker commissions of one or two month's rent for full time rentals.
[0012] To this end the present arrangement provides for a system for the storage and exchange of contracts and payments for an item. The system includes an interface for receiving inputs from a plurality of owners, each including information about at least one item and proposed contracting price for the item. A first database stores the received inputs and a processor manages the first interface and the database and is configured to store the received inputs.
[0013] A graphic user interface module, coupled to the processor, presents a plurality of item listings based on at least a portion of the inputs from the owners, where the interface is configured to receive at least one communication from a user seeking to contract with at least two items. The communication includes a proposed contract price for the items, and at least enough financial data of the user to complete a financial transaction with the owners for the items.
[0014] The processor is configured to receive the at least one communication and to present it to each of the owners associated with the at least two items in a manner such that each of the owners are informed of every other of the items included in the at least one communication. The processor is further configured to receive an acceptance from any of the owners associated with the at least two items from the communication from the user. Upon acceptance the processor is configured to conduct a financial transaction between the user and the owner and communicating the same to the user and the owner.
DESCRIPTION OF DRAWINGS
[0015] FIG. 1 is a rough schematic of the the prior art systems;
[0016] FIG. 2 is a rough schematic of the present invention, according to one embodiment;
[0017] FIG. 3 is a system diagram, according to one embodiment;
[0018] FIG. 4 is a flow chart for owners, according to one embodiment;
[0019] FIG. 5 is a screen shot of the system, according to one embodiment;
[0020] FIG. 6 is a screen shot of the system, according to one embodiment;
[0021] FIG. 7 is a screen shot of the system, according to one embodiment;
[0022] FIG. 8 is a screen shot of the system, according to one embodiment;
[0023] FIG. 9 is a screen shot of the system, according to one embodiment;
[0024] FIG. 10 is a screen shot of the system, according to one embodiment; and
[0025] FIG. 11 is a flow chart depicting the method of the present invention according to one embodiment.
DETAILED DESCRIPTION
[0026] The present arrangement provides a system and method for accepting, storing and presenting rental offers from a plurality of property owners and further allowing a renter to make a binding offer at their own price to one or more of the listed properties. Thereafter, the system and method supports displaying the offer to each of the property owners so that they not only know that they have received an offer, but the same offer has been extended to other properties, allowing the owners to gain a better perspective on the offer. Once an offer is accepted by one of the owners, assuming the offer does not expire for time, a binding contract is automatically generated between the owner and renter and the fees to renter and buyer are charged by the system.
[0027] For the purpose of illustrating each of the salient features of the present arrangement this application will be discussed in the context of vacation rentals and bids/offers between vacation home owners and prospective renters. However, this is intended only to be one example of the implementation of the invention and is not intended to be limiting. The features of the present invention may be equally applied to other situations, including but not limited to travel offers, real estate sales, ticket sales, car rentals, etc . . .
[0028] To this end, FIG. 3 shows a basic arrangement for the present system 10 having servers 12 for communicating with a plurality of renters 14 and property owners 16 . Servers 12 of system 10 are coupled to database storage 18 configured to store the various data required for accepting and storing the property details for the rental properties. Database 18 and servers 12 are further configured to store the various software and user interface modules for allowing and facilitating the offer/acceptance and transaction protocols. It is noted that in one embodiment, renters 14 and owners 16 communicate with system 10 via a mobile application on a portable electronic device. Such mobile application may be generic to the system or different versions may be available for owners 16 versus renters 14 .
[0029] Turning to the implementation of the rental offer services and bid/completion process, FIG. 4 is a brief flow chart explaining the account set up and submission process for property owners 16 . The following is a summary of one embodiment of the present arrangement.
[0030] In a first step 50 , system 10 enables an interface to receive a request for an account set up for property owner 16 . At step 52 , property owner 16 enters various identification information to generate an account, including, but not limited to user name, password and other security and banking information required to complete the transaction discussed herein. An optional step 54 may includes system 10 performing verification on property owner to verify banking information and to prevent fraudulent accounts. Once an account is set up, property owner 16 may log out, However, assuming property owner 16 is likewise ready to list a rental property, at step 56 property owner 16 begins a new listing operation and provides system 10 with the relevant information for the listing. Such information may include but is not limited to, the name and location of the property listing (e.g. rental) the available times for rental, the cost for rental, the dates on which property owner 16 will offer such a deal, additional notes on the property, photographs, contact information for additional questions from prospective renters etc . . . . As noted above, the rental example is exemplary only and any addition steps or modification, such as for property sales, commercial properties, travel etc . . . may be included.
[0031] Once this information is saved, at step 58 , the listing is generated in system 10 associated with property owner 16 and made available in the pool of listings according to its various searchable characteristics as discussed in more detail below. Other steps or information required to fulfill the requirements of the system may be added or supplemented as needed.
[0032] Turning to the renter side, the following description explains the process from a renter side, showing various screen shots for assisting in explaining the process. Such screen shots and descriptions of the renter bidding process are exemplary. It is understood, that different screen arrangements and other manners for progressing through the offer/acceptance processing are within the contemplation of the present invention.
[0033] Upon arriving at a system 10 homepage 200 , renters 14 can choose to either “Plan your next vacation” 210 or “Rent your next home” 212 as illustrated in screen shot FIG. 5 . As shown in FIG. 6 , in order to provide an example, of the function of system 10 , the present description uses an assumption of a potential renter 14 looking to rent a vacation property from owners 16 in East Hampton, N.Y. from November 11 th -16 th and wants to pay $1,000/night. After entering that information on homepage 200 above, search results 214 appear as depicted in FIG. 6 .
[0034] As shown in FIG. 7 , renter 14 can click on any of the results properties to find out more details, view pictures, learn more about owner/host 16 (i.e. through their Facebook™ or Linkedin™ profile), read previous renter's reviews, etc . . .
[0035] Next, the user can select from list 214 , various properties from owners 16 to add to their auction/offer cart 218 . As an example, referring to FIG. 8 , renter 14 has added six (6) properties 220 a - 220 f to cart 218 , Prior to submitting a binding offer and initiating a reverse auction, potential renter 14 is able to review their ‘Auction Cart’ 218 and compare/contrast their selections.
[0036] Referring to FIG. 9 , after the renter engages the offer, such as a “Launch My Auction” icon, a 24-hour (or other set duration) live reverse auction begins whereby all property owners 16 from offer cart 218 are notified via email and system 10 mobile app that their property has been selected for a reverse auction and the binding offer from renter 14 . The first property owner 16 to accept the offer, e.g. by hitting an “Accept offer now” tab 220 ends the reverse auction and closes/accepts the binding offer.
[0037] Upon the successful completion of the reverse auction, the credit card of renter 14 is debited and payment is made to property owner 16 less any service fees accepted by system 10 . Renter's 14 and owner's 16 contact information is shared with each other through system 10 to arrange details of their trip. A closing page screen shot 222 is shown in FIG. 10 .
[0038] Further to the above summary and screen shot walk through of an auction via system 10 , please see the following steps corresponding to the flow chart in FIG. 11 . As an initial phase, renters 14 come to the home page and have a choice to either “Plan your next vacation” or “Rent your next home” as shown in FIG. 5 . Similar to other prior art websites, renters 14 can search for properties by selecting various criteria, i.e., location, dates, # of guests, amenities, etc . . . using a detailed, customized searchable database. See e.g. FIG. 5-9 .
[0039] At a first step 100 , unlike other prior art websites, renters 14 enter the price they are willing to “offer” for either their vacation or full time rental. (E.g. only one offer per auction). See for example screen shot FIG. 9 and offer box 220 . In step 102 , renters 14 select as many properties that fit their criteria (regardless of the property owner's asking price) and add them to their “Auction Cart” 218 .
[0040] Prior to initiating the reverse auction, renters 14 may be required to register at the web site which includes electronically signing either a pre-approved lease or vacation rental agreement in addition to providing credit card information to secure their offer.
[0041] At step 104 - 106 from FIG. 11 , if renter 14 is satisfied with the cart contents, he receives an auction summary and can edit the auction if they desire. At steps 108 - 112 , once renter 14 has fulfilled the requirements to start the auction, they authorize payment and submit a binding offer that starts the auction. After renter 14 hits a “Launch My Auction” icon, a 24-hour live reverse auction begins whereby all property owners 16 in auction bin 218 are notified (via email and the system's mobile app) that theft property has been selected for a reverse auction and of the binding offer of renter 14 .
[0042] Property owners 16 are able to see all the other properties selected by renter 14 as part of the reverse auction, i.e., their “competition.” Property owners 16 are provided with a detailed profile of the prospective renter 14 and links to their Facebook™, Linkedin™ or other social media site accounts.
[0043] In step 114 , the first property owner to hit the “Accept offer now” tab (see 220 in FIG. 9 ) ends the reverse auction. Upon the successful completion of the reverse auction, the credit card of renter 14 is debited. Vacation renters 14 are charged the full amount of their rental and full time renters 14 are charged two months rent in addition to a security deposit or some other agreed upon amount. In step 116 , booking details may be generated to produce records of the transaction for renters 14 , owners 16 , and system 10 .
[0044] After the rental or vacation or, otherwise after the term of the agreement, renters 14 are able to post reviews after their stay and rate their experience enabling property owners 16 to establish a social profile within system 10 itself. Similarly, property owners 16 are encouraged to post reviews of renters 14 enabling renters 14 to establish a positive social profile on system 10 potentially making it easier for them to secure accepted offers from other owners 16 in future transactions.
[0045] In addition to the above described features, additional features and embodiments may be applied to the structure and steps outlined above. For example, in a first embodiment, the present arrangement may offer renters 14 the ability to join the network whereby prospective renters 14 can partner with each other and jointly submit a binding offer for a property. This feature expands the universe of properties for renters 14 and tenants for property owners 16 . For example, a vacation property owner 16 may be looking to rent their house only for the entire month of August and a renter 14 may only be interested in two weeks in August. By joining the present system 10 , renter 14 can learn of other likeminded renters 14 looking to rent for two weeks in August and they may be able to jointly offer a price for the entire month of August (possibly with each renter 14 signing separate rental agreements and being responsible for their respective times spent in the house).
[0046] Similarly, if a renter 14 is looking to lease an apartment for six months and a landlord 16 is only willing to accept a one year lease, that renter 14 can identify another renter 14 looking to lease the apartment for the other six months. By renters 14 combining theft respective demand curves to accommodate certain restrictions on landlords 16 supply, the present system 10 can further enhance the overall efficiencies of the marketplace.
[0047] In another embodiment, prospective renters 14 who are interested in a particular house and believe it is fairly priced may be able to bypass the above described reverse auction process and offer owner 16 their asking price by clicking on an “Instant Booking” tab next to each property listing.
[0048] In other embodiments, system 10 may include a mobile application, where vacation renters 14 are able to take pictures and videos of their trip and by the evening of their check out date, they automatically receive a fully edited picture/video montage set to music in their inbox courtesy of the system 10 .
[0049] While only certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes or equivalents will now occur to those skilled in the art. It is therefore, to be understood that this application is intended to cover all such modifications and changes that fall within the true spirit of the invention. | A system is provided for the storage and exchange of contracts and payments for an item. The processor of the system is configured to receive at least one communication and to present it to each of the owners associated with at least two items in a manner such that each of the owners are informed of every other of the items included in at least one communication from a potential purchaser/renter/user. The processor is further configured to receive an acceptance from any of the owners associated with the at least two items from the communication from the user. Upon acceptance the processor is configured to conduct a financial transaction between the user and the owner and communicating the same to the user and the owner. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to enzymatic denture adhesive compositions and, more particulary, to stabilized, aqueous, enzymatic denture adhesives, which, upon oral application, produce an anti-bacterial and bacteriostatic effect in the oral cavity by activation of the enzyme system within the adhesive.
[0003] Denture adhesives are used by denture wearers to secure loose fitting dentures. When a denture is first made, it fits tightly in the mouth. However, with the passage of time, the mouth changes and the denture often becomes less secure, with loss of the initial tight fit.
[0004] When this occurs, the patient has three choices: (a) obtain a new denture, (b) reline the old denture, or (c) use a denture adhesive. For those who choose denture adhesives, there are diverse products from which a selection can be made. These include powders, gels, pastes, and sheets. The adhesives are based on water soluble gums and polymers such as carboxymethyl cellulose, gum arcacia, gum tragacanth, poly(ethylene oxide), polyvinylpyrrolidone, vinyl methyl ether maleic anhydride, polyacrylamides, acetic polyvinyl compounds, polyacrylic acid derivates and the like.
[0005] The most common denture adhesives are those sold as pastes. The pastes are usually a combination of gums and powders combined with oil and/or other vehicle. The denture wearer squeezes the paste from a dispensing tube onto the denture which is then fitted into the mouth. Denture powders based on gums and/or polymers are also widely used by sprinkling the powder onto the denture which is then positioned in the mouth. Denture adhesives are also sold as sheets or films prepared from gums or polymers.
[0006] Regardless of the physical form of these adhesives, they all require contact with water to become effective. It is only when the gums and polymers become wet that they develop their adhesive properties. Normally, these adhesives work very well in the mouth. However, for denture wearers who suffer from dry mouth (xerostomia), dentures adesives work poorly or not at all because there is insufficient saliva to activate these adhesives, Also, because saliva is naturally antibacterial, people who suffer from dry mouth have an increased risk of periodontal disease, cavities and mouth odors.
[0007] The invention herein is directed to water-based denture adhesive compositions which incorporate (a) a hydro-activated anti-bacterial enzyme system and (b) a thickener so as to provide the composition with an enzyme immobilizing visvosity to inhibit enzymatic action during processing and in the denture adhesive package prior to oral application. The aqueous denture adhesive, with its anti-bacterial system, is particularly well suited for denture wearers who suffer from impaired saliva flow and provides those denture users with oral protection that would otherwise be present with normal saliva flow.
[0008] 2. Related Art
[0009] 2A. Enzyme Systems
[0010] It is disclosed in the prior art that enzymatic anti-bacterial systems, predicated on oxidoreductase enzymes such as glucose oxidase, can be incorporated into oral care products and other products such as powder milk (U.S. Pat. No. 4,617,190) and bandages (U.S. Pat. No. 4,576,817) for producing an anti-bacterial effect in a defined environment.
[0011] U.S. Pat. No. 4,150,113 (Hoogendoorn et al., 1979) and U.S. Pat. No. 4,178,362 (Hoogendorn et al., 1979) disclose, respectively, an enzymatic toothpaste and an enzymatic chewable dentifrice containing glucose oxidase which acts on glucose present in saliva and tooth plaque to produce hydrogen peroxide. The patentees note that oral bacteria, through enzyme systems having SH-Groups, effect glycolysis of food products containing sugars and point out that lactoperoxidase, which is present in saliva, provides the means for transferring oxygen from hydrogen peroxide to oral bacteria resulting in the oxidation of the SH-containing enzymes into inactive disulfide enzymes. It is further disclosed that the dentifrice may be formulated with potassium thiocyanate.
[0012] U.S. Pat. No. 4,269,822 (Pellico et al., 1981) discloses an antiseptic dentifrice containing an oxidizable amino acid substrate and an oxidoreductase enzyme specific to such substrate for producing hydrogen peroxide and ammonia upon oral application of the dentifrice, with pre-application stability being maintained by limiting the quantity of any water present in the dentifrice.
[0013] U.S. Pat. No. 4,537,764 (Pellico et al., 1985) discloses an enzymatic dentifrice containing Beta-D-glucose and glucose oxidase for producing hydrogen peroxide upon oral application of the dentifrice, with pre-application stability being maintained by limiting any water in the dentifrice to not more than about 10 wt. % based on the weight of the dentifrice.
[0014] U.S. Pat. No. 4,564,519 (Pellico et al., 1986) discloses a di-enzymatic chewable dentifrice which contains, for example, glucose and glucose oxidase for producing hydrogen peroxide upon chewing the dentifrice and further contains a thiocyanate salt and lactoperoxidase for interacting with hydrogen peroxide to produce a hypothiocyanate (sic) bacterial inhibitor, with pre-application stability being maintained by limiting any unbound water in the chewable dentifrice to an amount not more than about 1.0 wt. % and limiting the total water, bound and unbound, to not more than about 10 wt. %.
[0015] U.S. Pat. No. 4,578,365 (Pellico et al., 1986) discloses a di-enzymatic dentifrice which contains, for example, glucose and glucose oxidase for producing hydrogen peroxide upon oral application of the dentifrice and further contains a thiocyanate salt and lactoperoxidase for interacting with hydrogen peroxide to produce a hypothiocyanate (sic) with pre-application stability being maintained by limiting any water in the dentifrice to not more than about 10 wt. % based on the weight of the dentifrice.
[0016] U.S. Pat. No. 5,176,899 (Montgomery, 1993) discloses an aqueous enzymatic dentifrice which contains, for example, Beta-D-Glucose and glucose oxidase for producing hydrogen peroxide upon oral application of the dentifrice and, optionally, contains a thiocyanate salt and lactoperoxidase for interacting with hydrogen peroxide to produce a hypothiocyanite (OSCN—) bacteriostatic agent, with pre-application stability being maintained by processing and packaging the dentifrice under vacuum conditions so as to limit the level of dissolved oxygen in the dentifrice.
[0017] U.S. Pat. No. 5,336,494 (Pellico, 1994) discloses an orally chewable, enzymatically coated pet product which contains, for example, Beta-D-glucose and glucose oxidase for producing hydrogen peroxide upon oral chewing of the product and may further contain a peroxidase and an alkali metal salt of an oxygen accepting anion such as potassium iodide for interacting with hydrogen peroxide to produce hypoiodite, an anionic bacterial inhibitor.
[0018] U.S. Pat. No. 5,453,284 (Pellico, 1995) discloses an aqueous enzymatic dentifrice having a water content in excess of 10 wt. % and which contains, for example, Beta-D-glucose and glucose oxidase for producing hydrogen peroxide upon oral application of the dentifrice and may further contain a peroxidase and an oxidizable alkali metal salt such as the thiocyanate, chloride or iodide salt of sodium or potassium for interacting with hydrogen peroxide to produce an anionic bacterial inhibitor, with pre-application stability being maintained by the addition of a water soluble thickener in an amount to provide the dentifrice with a viscosity from about 800 to about 75,000 centipoises.
[0019] 2B. Denture Adhesives
[0020] U.S. Pat. No. 4,518,721 (Dhabhar et al., 1985) discloses a hydrophillic denture adhesive containing sodium carboxymethylcellulose, poly(ethylene oxide), polyethylene glycol and glycerin.
[0021] U.S. Pat. No. 4,804,412 (Komiyama, 1989) discloses a denture adhesive containing polyvinyl acetate and polypropylene oxide and which may further include other ingredients such as enzymes, as for example, dextranase, mutanase, levanase and in(s)ulinase.
[0022] U.S. Pat. No. 5,760,102 (Hall et al., 1998) discloses an aqueous denture adhesive containing aloe extract, polyvinylpyrrolidone, hydroxyethylcellulose, hydrogen peroxide and water.
[0023] U.S. Pat. No. 6,294,594 (Borja, 2001) discloses a denture cream formulation containing polyvinylpyrrolidone, poly(ethylene oxide), carboxymethylcellulose, mineral oil, petrolatum, polyacrylic acid derivative, silicon dioxide, flavor and dye.
[0024] Each of the foregoing patent references is incorporated herein by reference thereto.
SUMMARY OF THE INVENTION
[0025] In accordance with this invention, there is provided an aqueous enzymatic denture adhesive having a water content of at least about 10 wt. % and containing, per gram of adhesive, from about 0.015 to about 0.6 millimole of oxidizable substrate and from about 0.5 to about 5,000 International Units of oxidoreductase enzyme specific to such substrate for producing hydrogen peroxide upon oral application of the adhesive, and further containing non-toxic, ambient, water soluble thickener in an amount to provide the adhesive with a viscosity from about 300,000 to about 1,900,000 to therby stabilize the adhesive against the production of hydrogen peroxide prior to oral application of the adhesive.
DETAILED DESCRIPTION
[0026] The invention described herein is directed to the use of thickener in aqueous denture adhesive compositions containing hydro-activated and/or oxygen activated anti-bacterial enzyme system to thereby provide a viscosity which inhibits the enzymatic reaction prior to oral application of the adhesive.
[0027] The thickeners which can be used in the practice of this invention comprise non-toxic, water soluble hydrocolloids and synthetic polymers as, for example, (a) water soluble gums such as gum arabic, gum tragacanth, gum karaya or gum guar; (b) microbial fermentation hydrocolloids such as xanthan gum; (c) starch derivatives such as high viscosity starch or hydrogenated starch; (d) cellulose derivatives such as sodium carboxymethylcellulose or hydroxymethylcellulose; and (e) synthetic polymers/gums including (i) vinyl polymers such as polyvinylpyrrolidone, polyviny lalcohol and carboxyvinyl polymer, (ii) acrylic polymers such as polyacrylic acid and polyacrylamide, and (iii) ethylene oxide polymers. A particular effective thickener is a combination of polyacrylic acid and polyvinylpyrrolidone which may be further enhanced by the presence of hydrogenated starch.
[0028] The thickener is generally present in an amount to provide the enzymatic denture adhesive with a viscosity from about 300,000 to about 1,900,000 centipoises, with an intermediate amount being so selected as to provide the adhesive with a viscosity from about 400,000 to about 1,750,000 centipoises, and a preferred amount being so selected as to provide the adhesive with a viscosity from about 600,000 to about 1,600,000 centipoises. Viscosity determinations can be made by utilizing a suitable viscometer in accordance with applicable procedures well known in the art.
[0029] The enzymatic component of the therapeutic composition comprises a first enzyme system containing an oxidizable substrate and an oxidoreductase enzyme specific to such substrate for producing hydrogen peroxide upon oral application of the adhesive, with the chemical environment of the oral cavity providing the source of additional reactant (oxygen) or reactants (oxygen, water) to effect the enzymatic reaction. Illustrative examples of oxidoreductase enzymes and their corresponding oxidizable substrates are set forth in the following table:
TABLE A OXIDOREDUCTASE OXIDIZABLE ENZYME SUBSTRATE Glucose oxidase B-D-glucose Hexose Oxidase Hexose Galactose Oxidase D-galactose Pyranose Oxidase Pyranose Pyruvate Oxidase Pyruvate Oxalate Oxidase Oxalate DL-Aminoacid Oxidase DL-Aminoacid
[0030] In an illustrative reaction, glucose oxidase catalyzes the interaction of Beta-D-glucose, water and oxygen during oral application of the adhesive to produce hydrogen peroxide and gluconic acid.
[0031] Glucose oxidase is characterized in the literature as a glycoprotein containing two molecules of flavine-adenine dinucleotide which has a molecular weight of approximately 150,000, an isoelectric point at pH 4.2 and an optimum pH at 5.5 with a broad pH range from 4 through 7.
[0032] The oxidizable substrate is generally present in the adhesive composition in an amount from about 0.015 to about 0.6 millimole per gram of adhesive composition and, preferably, in an amount from about 0.025 to about 0.1 millimole per gram of adhesive composition while the oxidoreductase enzyme specific to the substrate is generally present in the composition in an amount from about 0.5 to about 500 International Units (herein sometimes abbreviated IU) per gram of composition, and, preferably, in an amount from about 10 to about 40 IU per gram of composition. The term millimole identifies that quantity in grams corresponding to the molecular weight of the composition divided by one thousand. The term International Unit(s) identifies that amount of enzyme that will effect catalysis of 1.0 micromole of substrate per unit at pH 7.0 and 25 C. Oxidoreductase enzymes are supplied in dry or liquid form with the label specifying the concentration in International Units on a per gram or per milliliter, as appropriate.
[0033] In addition to the first enzyme system comprising oxidizable substrate and oxidoreductase enzyme specific to such substrate for producing hydrogen peroxide, the enzymatic adhesive composition of this invention is provided with a second enzyme system containing a peroxidatic peroxidase and an alkali metal salt of an oxygen accepting anion for interacting with hydrogen peroxide to produce an oxidized anionic bacterial inhibitor.
[0034] Peroxidases which can be used in the practice of this invention include lactoperoxidase, horseradish peroxidase, iodide peroxidase, and myeloperoxidase. Oxidizable salts which can be used in the practice of this invention include, for example, the thiocyanate, chloride or iodide salt of sodium, potassium, ammonium, calcium or magnesium or mixtures of such salts. In the presence of hydrogen peroxide, the oxygen accepting anion of the aforesaid salts, namely, thiocyanate, chloride or iodide, are oxidized to hypothiocyanite, hypochlorite and hypoiodite, respetively.
[0035] Lactoperoxidase is a glycoprotein which, in one commercial embodiment, is a lyophilized powder derived from milk. This commercial peroxidase has an activity of 80 IU/mg and a projected molecular weight of 93,000 for L-Tyrosine lodination. The physical-chemical properties reported for lactoperoxidase include: molecular weight 78,000; partial specific volume 0.74; and heme/mole 1.0.
[0036] The peroxidase is generally present in the adhesive composition in an amount from about 0.05 to about 20 International Units per gram of composition and, preferably, in an amount from about 0.1 to about 1.0 International Units per gram of composition while the oxidizable salt is generally present in the composition in an amount from about 0.0001 to about 0.01 millimole per gram of composition and, preferably, in an amount from about 0.001 to about 0.006 millimole per gram of composition.
[0037] The operable integrity of the enzymatic system can be affected by catalase which is present in commercial glucose oxidase as well as mucous membrane tissue. Catalase, which is extraneous to the enzymatic system of this invention, competes with peroxidatic peroxidase for hydrogen peroxide. In order to reduce loss of hydrogen peroxide through the presence of catalase, an effective amount of enzymatic inhibitor specific to catalase can be advavtagelously incorporated into the enzymatic adhesive. An ascorbic salt such as sodium ascorbate, potassium ascorbate, ascorbyl palmitate, or mixtures thereof can be used as an enzymatic inhibitor which is specific to catalase. An effective amount of ascorbate salt for catalase inhibition is from about 0.000001 to about 0.0001 millimole per gram of adhesive composition. Iron salts such as ferrous sulfate can be incorporated the enzymatic composition as a potentiator for ascorbate salt in its role as catalase inhibitor.
[0038] The enzymatic adhesive compositions of this invention may advantageously be formulated with an aminohexose as, for example, an aminoglucose such as glucosamine, N-actyl glucosamine or mixtures thereof in order to increase the yield or accumulation of oxidized anionic bacterial inhibitor. The aminoglucose is generally present in the enzymatic composition in an amount from about 0.0001 to about 0.002 millimole per gram of adhesive and, preferably, in amount from about 0.003 to about 0.001 millimole per gram of adhesive.
[0039] As As a result of the high viscosity of the enzymatic adhesives provided by the thickeners, the adhesives can be formulated with water in excess of 10 wt. % without initiating an enzymatic reaction prior to oral application of the adhesive. Water is generally present in the enzymatic adhesive in an amount from about 10 wt. % to about 60 wt. %, with an intermediate amount being from about 10 wt. % to about 50 wt. % and a preferred amount being from about 15 wt. % to about 35 wt. %.
[0040] In addition to the thickeners, enzyme system and water, the adhesive compositions of this invention may contain typical formulating ingredients such as humectants, buffering agents, fluorides, flavors, colors and sweeteners as well as a variety of auxiliary adhesive components as described in the above identified patents, the disclosures of which are incorporated by reference, together with the limitations as specified therein.
[0041] The enzymztic adhesives, in the form of a paste or gel, can be prepared in any suitable manner as, for example, by blending the dry ingredients into the liquid ingredients, with agitation, until a smooth mixture is obtained, with the proviso that shear sensitive ingredients, which include the enzymes, are added last to minize shear impact on such ingredients.
[0042] In accordance with this invention, it has now been found that oxidoreductase enzyme stability can be maintained in an aqueous denture adhesive that contains in excess of 10 wt. % water, as shown by the examples hereinafter set forth, when a thickener is used in the aqueous adhesive so as to provide a viscosity of at least about 300,000 centipoises.
EXAMPLE 1
[0043] This example illustrates an aqueous, enzymatic denture adhesive containing 10 wt. % water together with an enzyme system containing Beta-D-glucose, glucose oxidase, lactoperoxidase and potassium thiocyanate.
Composition Weight, grams Glycerine 77.0000 D.I. Water 10.0000 Xanthan gum 4.0000 Carboxymethylcellulose 8.0000 Lactoperoxidase (100 IU/mg) 0.0005 (50 IU) Beta-D-glucose 1.0000 Glucose oxidase (100 IU) 0.0010 (100 IU) Potassium thiocyanate 0.1500 100.1515
EXAMPLE 2
[0044] This example illustrates an aqueous, enzymatic denture adhesive containing 15 wt. % water together with an enzyme system containing Beta-D-glucose, glucose oxidase, lactoperoxidase and potassium thiocyanate wherein the thickener is a combination of polyacrylic acid (Carbopol 980) and hydroxymethyl cellulose.
Composition Weight, grams Glycerine 42.0000 Sorbitol (70% solids, 30% water) 50.0000 Carbopol 980 3.0000 Hydroxymethylcellulose 3.0000 Beta-D-glucose 1.0000 Lactoperoxidase (100 IU/mg) 0.0005 (50 IU) Glucose oxidase (100 IU) 0.0010 (100 IU) Potassium thiocyanate 0.1500 Sodium hydroxide 1.0000 100.1515
EXAMPLE 3
[0045] This example illustrates an aqueous, enzymatic denture adhesive containing 10 wt. % water together with an enzyme system containing hexose, hexose oxidase, myeloperoxidase and potassium thiocyanate wherein the thickener is a combination of polyacrylic acid (Carbopol 980) and hydrogenated starch.
Composition Weight, grams Glycerine 10.0000 D.I. Water 10.0000 Hydrogenated starch 67.0000 Carbopol 980 4.0000 Hexose (100 IU/mg) 7.0000 Hexose oxidase (100 IU/mg) 0.0001 (10 IU) Myeloperoxidase (100 IUmg) 0.0002 (100 IU) Potassium thiocyanate 0.1500 Sodium hydroxide 2.0000 100.1503
EXAMPLE 4
[0046] This example illustrates an aqueous, enzymatic denture adhesive containing 57 wt. % water together with an enzyme system containing Beta-D-glucose, glucose oxidase, myeloperoxidase and potassium thiocyanate wherein the thickener is a combination of polyacrylic acid (Carbopol 980) and hydrogenated starch.
Composition Weight, grams D.I. Water 57.000 Hydrogenated starch 27.000 Carbopol 980 2.000 Polyvinylpyrrolidone 8.000 Beta-D-glucose 5.000 Glucose oxidase (100/IU/mg) 0.005 (500 IU) Myeloperoxidase (100/IUmg) 0.001 (100 IU) Potassium thiocyanate 0.150 Sodium hydroxide 1.000 100.150
EXAMPLE 5
[0047] This example illustrates an aqueous, enzymatic denture adhesive containing 14 wt. % water together with an enzyme system containing Beta-D-glucose, glucose oxidase, lactoperoxidase and potassium iodide wherein the thickener is a combination of hydrogenated starch, polyacrylic acid (Carbopol 980), and polyvinylpyrrolidone.
Composition Weight, grams D.I. Water 14.000 Glycerine 14.000 Hydrogenated starch 62.500 Carbopol 980 1.000 Polyvinylpyrollidone 8.000 Sodium hydroxide 0.050 Beta-D-glucose 0.050 Glucose oxidase (100 IU/mg) 0.008 Lactoperoxidase (100 IU/gm) 0.010 Potassium iodide 0.004 99.6184
[0048] Adjunct antibacterial agents such as the enzyme lysozyme and the protein lactoferrin can also be added to the enzymatic formulations of this invention.
[0049] In view of the foregoing description and examples, it will become apparent to those of ordinary skill in the art that equivalent modifications thereof may be made without departing from the spirit and scope of this invention. | Hydro-activated and/or oxygen activated aqueous, enzymatic, antimicrobials denture adhesive compositions are stabilized against enzymatic action prior to oral application of the adhesive by incorporating a thickener into the adhesive formulation so as to provide the forrmulation with an enzyme immobilizing viscosity which inhibits enzymatic action during processing and in the adhesive package. An illustrative, thickened, enzymatic adhesive with this enhancement contains glucose oxidase, glucose, lactoperoxidase and potassium thiocyanate together with a mixture of polyacrylic acid and polyvinylpyrrolidone in an amount to provide the adhesive with a viscosity of at least about 300,000 centipoises. | 0 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to reconfigurable computing.
[0003] 2. State of the Art
[0004] Traditionally, an integrated circuit must be designed by describing its structure with circuit primitives such as Boolean gates and registers. The circuit designer must begin with a specific application in mind, e.g. a video compression algorithm, and the resulting integrated circuit can only be used for the targeted application.
[0005] Alternatively, an integrated circuit may be designed as a general purpose microprocessor with a fixed instruction set, e.g. the Intel ×86 processors. This allows flexibility in writing computer programs which can invoke arbitrary sequences of the microprocessor instructions. While this approach increases the flexibility, it decreases the performance since the circuitry cannot be optimized for any specific application.
[0006] It would be desirable for high level programmers to be able to write arbitrary computer programs and have them automatically translated into fast application specific integrated circuits. However, currently there is no bridge between the computer programmers, who have expertise in programming languages for microprocessors, and the application specific integrated circuits, which require expertise in circuit design.
[0007] Research and development in integrated circuit design is attempting to push the level of circuit description to increasingly higher levels of abstraction. The current state of the art is the “behavioral synthesizer” whose input is a behavioral language description of the circuit's register/transfer behavior and whose output is a structural description of the circuit elements required to implement that behavior. The input description must have targeted a specific application and must describe its behavior in high level circuit primitives, but the behavioral compiler will automatically determine how many low level circuit primitives are required, how these primitives will be shared between different blocks of logic, and how the use of these primitives will be scheduled. The output description of these circuit primitives is then passed down to a “logic synthesizer” which maps the circuit primitives onto a library of available “cells”, where each cell is the complete implementation of a circuit primitive on an integrated circuit. The output of the logic synthesizer is a description of all the required cells and their interconnections. This description is then passed down to a “placer and router” which determines the detailed layout of all the cells and interconnections on the integrated circuit.
[0008] On the other hand, research and development in computer programming is also attempting to push down a level of abstraction by matching the specific application programs with custom targeted hardware. One such attempt is the Intel MMX instruction set. This instruction set was designed specifically to accelerate applications with digital signal processing algorithms. Such applications may be written generically and an MMX aware compiler will automatically accelerate the compiled code by using the special instructions. Another attempt to match the application with appropriate hardware is the work on parallelizing compilers. These compilers will take a computer program written in a sequential programming language and automatically extract the implicit parallelism which can then be targeted for execution on a variable number of processors. Thus different applications may execute on a different number of processors, depending on their particular needs.
[0009] Despite the above efforts by both the hardware and software communities, the gap has not yet been bridged between high level programming languages and integrated circuit behavioral descriptions.
SUMMARY OF THE INVENTION
[0010] A computer program, written in a high level programming language, is compiled into an intermediate data structure which represents its control and data flow. This data structure is analyzed to identify critical blocks of logic which can be implemented as an application specific integrated circuit to improve the overall performance. The critical blocks of logic are first transformed into new equivalent logic with maximal data parallelism. The new parallelized logic is then translated into a Boolean gate representation which is suitable for implementation on an application specific integrated circuit. The application specific integrated circuit is coupled with a generic microprocessor via custom instructions for the microprocessor. The original computer program is then compiled into object code with the new expanded target instruction set.
[0011] In accordance with one embodiment of the invention, a computer implemented method automatically compiles a computer program written in a high level programming language into a program for execution by one or more application specific integrated circuits coupled with a microprocessor. Code blocks the functions of which are to be performed by circuitry within the one or more application specific integrated circuits are selected, and the code blocks are grouped into groups based on at least one of an area constraint and an execution timing constraint. Loading and activation of the functions are scheduled; and code is produced for execution by the microprocessor, including instructions for loading and activating the functions.
[0012] In accordance another aspect of the invention, a computer implemented method automatically compiles a computer program written in a high level programming language into one or more application specific integrated circuits. In accordance with yet another aspect of the invention, a computer implemented method automatically compiles a computer program written in a high level programming language into one or more application specific integrated circuits coupled with a standard microprocessor. In accordance with still another aspect of the invention, a reconfigurable logic block is locked by compiled instructions, wherein an activate configuration instruction locks the block from any subsequent activation and a release configuration instruction unlocks the block. In accordance with a further aspect of the invention, a high level programming language compiler automatically determines a set of one or more special instructions to extend the standard instruction set of a microprocessor which will result in a relative performance improvement for a given input computer program. In accordance with yet a further aspect of the invention, a method is provided for transforming the execution of more than one microprocessor standard instruction into the execution of a single special instruction. In accordance with still a further aspect of the invention, a high level programming language compiler is coupled with a behavioral synthesizer via a data flow graph intermediate representation.
BRIEF DESCRIPTION OF THE DRAWING
[0013] The present invention may be further understood from the following description in conjunction with the appended drawing. In the drawing:
[0014] [0014]FIG. 1 shows the design methodology flow diagram of the preferred embodiment of a compiler.
[0015] [0015]FIG. 2 shows the control flow for the operation of the preferred embodiment of an application specific integrated circuit.
[0016] [0016]FIG. 3 shows a fragment of a high level source code example which can be input into the compiler.
[0017] [0017]FIG. 4 shows the microprocessor object code for the code example of FIG. 3 which would be output by a standard compiler.
[0018] [0018]FIG. 5 shows an example of the application specific circuitry which is output by the compiler for the code example of FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] In accordance with the preferred embodiment of the present invention, a method is presented for automatically compiling high level programming languages into application specific integrated circuits (ASIC).
[0020] Referring to FIG. 1, the computer program source code 101 is parsed with standard compiler technology 103 into a language independent intermediate format 105 . The intermediate format 105 is a standard control and data flow graph, but with the addition of constructs to capture loops, conditional statements, and array accesses. The format's operators are language independent simple RISC-like instructions, but with additional operators for array accesses and procedure calls. These constructs capture all the high level information necessary for parallelization of the code. For further description of a compiled intermediate format see for example S. P. Amarasinghe, J. M. Anderson, C. S. Wilson, S. -W. Liao, B. M. Murphy, R. S. French, M. S. Lam and M. W. Hall; Multiprocessors from a Software Perspective; IEEE Micro, June 1996; pages 52-61.
[0021] Because standard compiler technology is used, the input computer program can be any legal source code for a supported high level programming language. The methodology does not require a special language with constructs specifically for describing hardware implementation elements. Front end parsers currently exist for ANSI C and FORTRAN 77 and other languages can be supported simply by adding new front end parsers. For further information on front end parsers see for example C. W. Fraser and D. R. Hanson; A Retargetable Compiler for ANSI C; SIGPLAN Notices, 26(10); October 1991.
[0022] From the intermediate format 105 , the present methodology uniquely supports code generation for two different types of target hardware: standard microprocessor and ASIC. Both targets are needed because while the ASIC is much faster than the microprocessor, it is also much larger and more expensive and therefore needs to be treated as a scarce resource. The compiler will estimate the performance versus area tradeoffs and automatically determine which code blocks should be targeted for a given available ASIC area.
[0023] Code generation for the microprocessor is handled by standard compiler technology 107 . A code generator for the MIPS microprocessor currently exists and other microprocessors can be supported by simply adding new back end generators. In the generated object code 109 , custom instructions are inserted which invoke the ASIC-implemented logic as special instructions.
[0024] The special instructions are in four general categories: load_configuration, activate_configuration, invoke_configuration, release_configuration. The load_configuration instruction identifies the address of a fixed bit stream which can configure the logic and interconnect for a single block of reconfigurable logic on the ASIC. Referring to FIG. 2, the ASIC 200 may have one or more such blocks 201 a , 201 b on a single chip, possibly together with an embedded microprocessor 205 and control logic 207 for the reconfigurable logic. The identified bit stream may reside in, for example, random access memory (RAM) or read-only-memory (PROM or EEPROM) 203 . The bit stream is downloaded to a cache of possible block configurations on the ASIC. The activate_configuration instruction identifies a previously downloaded configuration, restructures the reconfigurable logic on the ASIC block according to that configuration, and locks the block from any subsequent activate instructions. The invoke_configuration instruction loads the input operand registers, locks the output registers, and invokes the configured logic on the ASIC. After the ASIC loads the results into the instruction's output registers, it unlocks the registers and the microprocessor can take the results and continue execution. The release_configuration instruction unlocks the ASIC block and makes it available for subsequent activate_configuration instructions. For further description of an embedded microprocessor with reconfigurable logic see U.S. patent application Ser. No. 08/884,380 of L. Cooke, C. Phillips, and D. Wong for An Integrated Processor and Programmable Data Path Chip for Reconfigurable Computing, incorporated herein by reference.
[0025] Code generation for the ASIC logic can be implemented by several methods. One implementation passes the intermediate control and data flow graphs to a behavioral synthesis program. This interface could be accomplished either by passing the data structures directly or by generating an intermediate behavioral language description. For further discussion of behavioral synthesis see for example D. Knapp; Behavioral Synthesis; Prentice Hall PTR; 1996. An alternative implementation generates one-to-one mappings of the intermediate format primitives onto a library of circuit implementations. For example: scalar variables and arrays are implemented as registers and register files with appropriate bit widths; arithmetic and Boolean operators such as add, multiply, accumulate, and compare are implemented as single cells with appropriate bit widths; conditional branch implementations and loops are implemented as state machines. In general, as illustrated in FIG. 1, a silicon compiler 113 receives as inputs compiled code in the intermediate format 105 and circuit primitives from a circuit primitive library 115 and produces layout or configuration information for an ASIC 117 . For further discussion of techniques for state machine synthesis see for example G. De Micheli, A. Sangiovanni-Vincentelli, and P. Antognetti; Design Systems for VLSI Circuits; Martinus Nijhoff Publishers; 1987; pp. 327-364.
[0026] After the synthesis or mapping step is completed, an equivalent list of cells and their interconnections is generated. This list is commonly referred to as a netlist. This netlist is then passed to a placer and router which determines the actual layout of the cells and their interconnections on an ASIC. The complete layout is then encoded and compressed in a bit stream format which can be stored and loaded as a single unit to configure the ASIC. A step-by-step example of the foregoing process is illustrated in FIG. 3, FIG. 4, and FIG. 5. For a general discussion of place and route algorithms see T. Ohtsuki; Layout Design and Verification; North-Holland; 1986; pp. 55-198.
[0027] The basic unit of code that would be targeted for an ASIC is a loop. A single loop in the input source code may be transformed in the intermediate format into multiple constructs for runtime optimization and parallelization by optimizer and parallelizer 111 in FIG. 1. The degree of loop transformation for parallel execution is a key factor in improving the performance of the ASIC versus a microprocessor. These transformations are handled by standard parallelizing compiler technology which includes constant propagation, forward propagation, induction variable detection, constant folding, scalar privatization analysis, loop interchange, skewing, and reversal. For a general discussion of parallel compiler loop transformations see Michael Wolfe; High Performance Compilers for Parallel Computing; Addison-Wesley Publishing Company; 1996; pp. 307-363.
[0028] To determine which source code loops will yield the most relative performance improvement, the results of a standard source code profiler are input to the compiler. The profiler analysis indicates the percentage of runtime spent in each block of code. By combining these percentages with the amount of possible parallelization for each loop, a figure of merit can be estimated for the possible gain of each loop. For example:
Gain = (profilePercent) * (1 − 1 / parallelPaths) where profilePercent = percent of runtime spent in this loop parallelPaths = number of paths which can be executed in parallel
[0029] The amount of ASIC area required to implement a source code loop is determined by summing the individual areas of all its mapped cells and estimating the additional area required to interconnect the cells. The size of the cells and their interconnect depends on the number bits needed to implement the required data precision. The ASIC area can serve as a figure of merit for the cost of each loop. For example:
Cost = cellArea + MAX(0, (interconnectArea − overTheCellArea)) where cellArea = sum of all component cell areas overTheCellArea = cellArea * (per cell area available for interconnects) interconnectArea = (number of interconnects) * (interconnectLength) * (interconnect width) interconnectLength = (square root of the number of cells) / 3
[0030] For further information on estimating interconnect area see B. Preas, M. Lorenzetti; Physical Design Automation of VLSI Systems; Benjamin/Cummings Publishing Company; 1988; pp. 31-64.
[0031] The method does not actually calculate the figures of merit for all the loops in the source code. The compiler is given two runtime parameters: the maximum area for a single ASIC block, and the maximum total ASIC area available, depending on the targeted runtime system. It first sorts the loops in descending order of their percentage of runtime, and then estimates the figures of merit for each loop until it reaches a predetermined limit in the total amount of area estimated. The predetermined limit is a constant times the maximum total ASIC area available. Loops that require an area larger than a single ASIC block may be skipped for a simpler implementation. Finally, with all the loops for which figures of merit have been calculated, a knapsack algorithm is applied to select the loops. This procedure can be trivially extended to handle the case of targeting multiple ASICs if there is no gain or cost associated with being in different ASICs. For a general discussion of knapsack algorithms see Syslo, Deo, Kowalik; Discrete Optimization Algorithms; Prentice-Hall; 1983; pp. 118-176.
[0032] The various source code loops which are packed onto a single ASIC are generally independent of each other. With certain types of ASICs, namely a field programmable gate array (FPGA), it is possible to change at runtime some or all of the functions on the FPGA. The FPGA has one or more independent blocks of reconfigurable logic. Each block may be reconfigured without affecting any other block. Changing which functions are currently implemented may be desirable as the computer program executes different areas of code, or when an entirely different computer program is loaded, or when the amount of available FPGA logic changes.
[0033] A reconfigurable FPGA environment presents the following problems for the compiler to solve: selecting the total set of functions to be implemented, partitioning the functions across multiple FPGA blocks, and scheduling the loading and activation of FPGA blocks during the program execution. These problems cannot be solved optimally in polynomial time. The following paragraphs describe some heuristics which can be successfully applied to these problems.
[0034] The set of configurations simultaneously coexisting on an FPGA at a single instant of time will be referred to as a snapshot. The various functions comprising a snapshot are partitioned into the separate blocks by the compiler in order to minimize the block's stall time and therefore minimize the overall execution schedule. A block will be stalled if the microprocessor has issued a new activate_configuration instruction, but all the functions of the previous configuration have not yet completed. The partitioning will group together functions that finish at close to the same time. All the functions which have been selected by the knapsack algorithm are sorted according to their ideal scheduled finish times (the ideal finish times assume that the blocks have been downloaded and activated without delay so that the functions can be invoked at their scheduled start times). Traversing the list by increasing finish times, each function is assigned to the same FPGA block until the FPGA block's area capacity is reached. When an FPGA block is filled, the next FPGA block is opened. After all functions have been assigned to FPGA blocks, the difference between the earliest and the latest finish times is calculated for each FPGA block. Then each function is revisited in reverse (decreasing) order. If reassigning the function to the next FPGA block does not exceed its area capacity and reduces the maximum of the two differences for the two FPGA blocks, then the function is reassigned to the next FPGA block.
[0035] After the functions are partitioned, each configuration of an FPGA block may be viewed as a single task. Its data and control dependencies are the union of its assigned function's dependencies, and its required time is the difference between the latest finish time and the earliest start time of its assigned functions. The set of all such configuration tasks across all snapshots may be scheduled with standard multiprocessor scheduling algorithms, treating each physical FPGA block as a processor. This will schedule all the activate_configuration instructions.
[0036] A common scheduling algorithm is called list scheduling. In list scheduling, the following steps are a typical implementation:
[0037] 1. Each node in the task graph is assigned a priority. The priority is defined as the length of the longest path from the starting point of the task graph to the node. A priority queue is initialized for ready tasks by inserting every task that has no immediate predecessors. Tasks are sorted in decreasing order of task priorities.
[0038] 2. As long as the priority queue is not empty do the following:
[0039] a. A task is obtained from the front of the queue.
[0040] b. An idle processor is selected to run the task.
[0041] c. When all the immediate predecessors of a particular task are executed, that successor is now ready and can be inserted into the priority queue.
[0042] For further information on multiprocessor scheduling algorithms see A. Zomaya; Parallel and Distributed Computing Handbook; McGraw-Hill; 1996; pp. 239-273.
[0043] All the load_configuration instructions may be issued at the beginning of the program if the total number of configurations for any FPGA block does not exceed the capacity of the FPGA block's configuration cache. Similarly, the program may be divided into more than one section, where the total number of configurations for any FPGA block does not exceed the capacity of the FPGA block's configuration cache. Alternatively, the load_configuration instructions may be scheduled at the lowest preceding branch point in the program's control flow graph which covers all the block's activat_configuration instructions. This will be referred to as a covering load instruction. This is a preliminary schedule for the load instructions, but will lead to stalls if the actual load time exceeds the time the microprocessor requires to go from the load_configuration instruction to the first activate_configuration instruction. In addition, the number of configurations for an FPGA block may still exceed the capacity of its configuration cache. This will again lead to stalls in the schedule. In such a case, the compiler will compare the length of the stall versus the estimated gains for each of the configurations in contention. The gain of a configuration is estimated as the sum of the gains of its assigned functions. Among all the configurations in contention, the one with the minimum estimated gain is found. If the stall is greater than the minimum gain, the configuration with the minimum gain will not be used at that point in the schedule.
[0044] When a covering load instruction is de-scheduled as above, tentative load_configuration tasks will be created just before each activate_configuration instruction. These will be created at the lowest branch point immediately preceding the activate instruction. These will be referred to as single load instructions. A new attempt will be made to schedule the single load command without exceeding the FPGA block's configuration cache capacity at that point in the schedule. Similarly to the previous scheduling attempt, if the number of configurations again exceeds the configuration cache capacity, the length of the stall will be compared to the estimated gains. In this case, however, the estimated gain of the configuration is just the gain of the single function which will be invoked down this branch. Again, if the stall is greater than the minimum gain, the configuration with the minimum gain will not be used at that point in the schedule.
[0045] If a de-scheduled load instruction is a covering load instruction, the process will recourse; otherwise if it is a single load instruction, the process terminates. This process can be generalized to shifting the load instructions down the control flow graph one step at a time and decreasing the number of invocations it must support. For a single step, partition each of the contending configurations into two new tasks. For the configurations which have already been scheduled, split the assigned functions into those which finish by the current time and those that don't. For the configuration which has not been scheduled yet, split the assigned functions into those which start after the stall time and those that don't.
[0046] Branch prediction may be used to predict the likely outcome of a branch and to load in advance of the branch a configuration likely to be needed as a result of the branch. Inevitably, branch prediction will sometimes be unsuccessful, with the result that a configuration will have been loaded that is not actually needed. To provide for these instances, instructions may be inserted after the branch instruction to clear the configuration loaded prior to the branch and to load a different configuration needed following the branch, provided that a net execution-time savings results.
[0047] It will be appreciated by those of ordinary skill in the art that the invention can be embodied in other specific forms without departing from the spirit or essential character thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the appended claims rather than the foregoing description, and all changes which come within the meaning and range of equivalents thereof are intended to be embraced therein. | A computer program (item 101 ), written in a high level programming language, is compiled (item 103 ) into an intermediate data structure ( 105 ) which represents its control and data flow. This data structure is analyzed (item 111 ) to identify critical blocks of logic which can be implemented as an application specific integrated circuit (item 117 ) to improve the overall performance. The critical blocks of logic are first transformed into new equivalent logic with maximum data parallelism. The new parallelized logic is then translated into a Boolean gate representation which is suitable for implementation on an application specific integrated circuit (item 117 ). The application specific integrated circuit (item 117 ) is coupled with a generic microprocessor via custom instructions for the microprocessor (item 107 ). The original computer program is then compiled into object code (item 109 ) with the new expanded target instruction set. | 6 |
BACKGROUND OF THE INVENTION
The quick freezing of meat process is aided by the disclosed device. Presently, most meat processing plants are using either a wooden spacer or a stainless steel spacer. Several disadvantages are encountered in these present methods:
1. The cleaning of a wooden spacer is both a difficult and time-consuming job;
2. Wood has a tendency to splinter and absorb water; and
3. The cost of stainless steel is much greater than the disclosed and instantly claimed invention.
BRIEF SUMMARY OF THE INVENTION
A meat spacer tray of molded plastic for freezing and storing meat is disclosed wherein an open array of holes, ribs, and connectors permit free circulation of air around meats placed thereon and also will hold odd-shaped cuts of meat such as hams.
It is an object of this device to be easily cleanable.
It is an object of this device to be nestable for ease of storage when not in use.
It is an object of this device to avoid crevices which will afford sites for the undesirable growth of bacteria.
It is an object of this device to have both a one piece construction and a non-porous surface.
It is an object of this device to be steam cleanable and also withstand low temperatures of about -60°F.
It is an object of this device to promote efficient air flow to aid rapid and uniform freezing.
Other objects and advantages of our invention will be apparent to those skilled in the art upon reading this specification.
BRIEF DESCRIPTION OF THE INVENTION
The meat freezing spacer and tray of molded plastic is disclosed in FIGS. 1-4.
FIG. 1 is a top perspective view of the meat spacer tray of molded plastic.
FIG. 2 is an enlarged top plan view of the bottom corner section of the meat spacer tray of molded plastic as shown in FIG. 1.
FIG. 3 is an enlarged cross-section side elevation view of the meat spacer tray of molded plastic along the line 3--3 as shown in FIG. 1.
FIG. 4 is a front elevation view of the meat spacer tray of molded plastic along line 4--4 in the direction of the arrow as shown in FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
Our invention consists of a meat spacer tray of molded plastic. The tray has been specifically designed to facilitate uniform and rapid freezing of meat by permitting the passage of air around meat placed between two meat spacer trays. In its simplest form our meat spacer tray consists of the following basic elements: top planar rectangular members [FIG. 1, 1-6], bottom rectangular planar members [FIG. 1, 7-11], and connecting means [FIG. 1, 12-22] to hold the top and bottom planar rectangular members in fixed positions with respect to one another. To the previously described basic structure are added the following elements which impart additional strength and stability to the meat spacer tray, i.e., flanges [FIG. 3, 23] and ribs [FIG. 1, 24-25]. The top rectangular planar members [FIG. 3, 1-2] have their longer sides extending in the longitudinal direction of the spacer and each of said members top and bottom rectangular planar surfaces are coplanar to one and another, respectively. The top [FIG. 3, 37] and bottom [FIG. 3, 53] surfaces of one said member [FIG. 3, 1] being coplanar to the corresponding surfaces [FIG. 3, 38 and 30] of other said members [FIG. 3, 2]. There are two types of top planar members. The first said top type [FIG. 1, 2-5] has two rows of square holes [FIG. 1, 26] extending between said types' top and bottom surfaces wherein said square holes have rounded corners [FIG. 2, 27], the top edges of said square holes being rounded [FIG. 3, 28] and the side surfaces [FIG. 3, 29] of said square holes are normal to the bottom surfaces [FIG. 3, 30] of said top members. The second said top type has a single row of rectangular holes [FIG. 2, 31] extending between said types' top and bottom surfaces wherein the longer sides of the said rectangular holes are parallel to said longitudinal direction of the spacer. The two top outside rectangular planar members [FIG. 1, 1 and 6] having their longer sides in the longitudinal direction of said spacer each have a single row of said rectangular holes [FIG. 2, 31]. The remaining top planar rectangular members, all have at least one row of square holes. It is to be noted that the invention is not intended to be limited to any particular kind of holes in either the top or bottom planar members, nor should the invention be limited to holes which have particular rounded surfaces or normal sides to the surfaces of either the top or bottom planar rectangular members.
There are two flanges [FIG. 3, 23] attached to the bottom horizontal rectangular surface [FIG. 3, 30] along both longitudinal edges of all top rectangular planar members. The sides of said flanges [FIG. 3, 32] extend downward from the top planar member so that the bottom surface [FIG. 3, 33] of each said flange is spaced above the top planar surface [FIG. 3, 34] of the hereinafter recited adjacent bottom rectangular members [FIG. 1, 7-11]. These flanges are intended as structural pieces to strengthen the overall meat spacer tray. One vertical surface [FIG. 3, 36] of said flange and the bottom said surface [FIG. 3, 35] of the top planar member forms a right angle and the other vertical surface [FIG. 3, 32] of said flange is continuous with and coplanar to a vertical longitudinal side [FIG. 3, 32] of said top rectangular member. Said other vertical surface of said flange forms a right angle between said vertical longitudinal side [FIG. 3, 32] and the top rectangular planar surface [FIG. 3, 37] of said top planar member [FIG. 3, 1].
There are bottom rectangular members [FIG. 1, 7-11] which have their longer sides extending longitudinally and each of said members top [FIG. 3, 34 and 40] and bottom rectangular planar surfaces [FIG. 3, 39 and 41] are coplanar to one another respectively. That is, the top [FIG. 3, 40] and bottom [FIG. 3, 39] surfaces of one said member [FIG. 3, 7] are coplanar to the corresponding surfaces [FIG. 3, 34 and 41] of other said members [FIG. 3, 8]. These said members are of two types. The first said type [FIG. 1, 7 and 11] of bottom rectangular planar members has a single row of square holes [FIG. 3, 42] extending between the top [FIG. 3, 40] and bottom [FIG. 3, 39] horizontal rectangular surfaces of said member [FIG. 3, 7]. These holes have rounded [FIG. 2, 43] corners. The side surfaces [FIG. 3, 44] of said holes are normal to the top surfaces [FIG. 3, 40] of said members. The bottom edges [FIG. 3, 45] of said holes are rounded. The second said type [FIG. 1, 8-10] of bottom rectangular planar member has two rows of square holes extending between the top and bottom horizontal rectangular surfaces of said member. The said square holes have rounded corners. The side surfaces of said square holes are at right angles to the top surfaces of said members. The bottom edges of said square holes are rounded. It should be noted that the particular arrangement of holes previously described is but one claimed example in a more general meat spacer tray wherein the exact nature of the holes generally in a vertical direction to the top and bottom surfaces of the planar rectangular members are less defined.
In one embodiment of our meat spacer tray said bottom members have two sloping longitudinally extending sides [FIG. 3, 46 and 47] wherein said sloping longitudinally extending sides are along the two longer edges of said member. They form an angle ranging from 90° to 170° as measured within said member between one said sloping side [FIG. 3, 46] and the bottom rectangular planar surface of a bottom planar member [FIG. 3, 39].
The top and bottom planar rectangular members are positionally related to one another in two ways. The first way is that the outer planar rectangular members [FIG. 1, 1 and 6] are top planar rectangular members having a single row of rectangular holes and positionally adjacent (hereinafter defined) to these said members are two bottom planar rectangular members [FIG. 1, 7 and 11] each having a single row of square holes. The second said way is that positionally adjacent to the two said bottom planar rectangular members [FIG. 1, 7 and 11], wherein each said member has a single row of holes, are two top rectangular [FIG. 1, 2 and 5] members each having two rows of square holes. Positionally adjacent to said top planar members [FIG. 1, 2 and 5] are two bottom planar members [FIG. 1, 8 and 10]. Said top [FIG. 1, 2-5] and said bottom [FIG. 1, 8-10] planar members alternate with one another so that between each bottom planar member is a top planar member except for the two outside top planar members [FIG. 1, 1 and 6]. The top planar members on the outside have at least one row of rectangular holes [FIG. 3, 31]. The direction of the longer sides of said rectangular holes is in the longitudinal direction. The overall arrangement of top and bottom rectangular planar members is such that between two top planar rectangular members there will always be a bottom planar rectangular member. Again it is noted for emphasis that the invention should not and is not intended to be limited to the particular type and arrangement of holes penetrating the top and bottom surfaces of the planar rectangular members.
Positions of planar members adjacent to one another mean the two positions occupied by a top planar member [FIG. 1, 2] and one of its nearest neighbors, a bottom planar member [FIG. 1, 7 or 8] and vice versa, wherein if one were to imagine that a top planar member [FIG. 1, 2] were to be moved down vertically and then moved horizontally in a direction perpendicular to said members longer side, then said "moved" member would occupy the same position as said member's nearest neighbor, a bottom planar member [FIG. 1, 7 or 8] and similarly if one were to imagine a bottom planar member [FIG. 1, 7] moved upward vertically and then horizontally in a direction perpendicular to said members longer edge then said "moved" member would occupy the same position as said members nearest neighbor, a top planar member [FIG. 1, 1 or 2].
Connecting means are provided to hold the top and bottom planar rectangular members in a fixed position with respect to one another. Examples of said connecting means are connectors [FIG. 1, 12-22] and/or transverse ribs [FIG. 1, 25]. One suitable shape of these connectors is a frustum. For purposes of illustration the connectors will be referred to as frustum connectors. A plurality of spaced apart frustum connectors [FIG. 1, 12-22] extend between bottom rectangular planar members and top planar rectangular members. In one specific embodiment of our invention, there are three types of frustum connectors. However, it is to be noted that in a more general structure, the type and shape of particular connectors need not be so limited. The first said type of frustum connector [FIG. 1, 12 and 22] is at each end of every bottom rectangular planar member. The second said type [FIG. 1, 13, 15, 17, 19 and 21] is spaced inward toward the center of the meat spacer tray in the longitudinal direction from the first said type and is connected along the longitudinal edge of said bottom planar rectangular member. The third type [FIG. 1, 14, 16, 18, and 20] is spaced inward toward the center of the meat spacer tray in the longitudinal direction from the said second type and this third said type alternates with the second said type along both longitudinal top edges of the bottom planar member. All frustum connectors of types one, two or three connect the top surface [FIG. 3, 40] of said bottom planar members to the side [FIG. 3, 32] and flange [FIG. 3, 23] of the nearest (adjacent) top planar member [FIG. 3, 1 or 2]. The frustum connectors have one side [FIG. 1, 48, 49, and 50] sloping in such a manner as to form an angle between said sloping side of the frustum connector and the top planar surface of the top rectangular planar members. An angle of between 90° and 170° as measured internally is formed between said sloping planar side [FIG. 1, 48, 49 and 50] of said frustum connectors and the top planar surface of the top planar rectangular member. The side [FIG. 3, 51] of said frustum connector opposite the previously described sloping planar side [FIG. 3, 50] is continuous with and coplanar to the sloping sides [FIG. 3, 46] of said bottom rectangular planar member [FIG. 3, 7].
A plurality of rectangular holes are defined by the sides of frustum connectors [FIG. 1, 12-22], the top of the bottom rectangular members and the bottom [FIG. 3, 33] of the downwardly extending flanges. It is to be noted that in the more general structure for this invention there are no flange pieces.
In order to impart strength and stability to our meat spacer or as connecting means to hold top and bottom planar members in fixed positions with respect to one another, there are included a plurality of ribs [FIG. 1, 24 and 25]. Said ribs traverse the longitudinal direction of the bottom planar members. These ribs are of two types. The first type [FIG. 1, 24 and 25] is attached to the top surfaces of bottom planar members wherein said first type forms inner [FIG. 1, 25] and outer [FIG. 1, 24] ribs. The outer said ribs [FIG. 1, 24] have three fused surfaces. The first said fused surface is between the bottom surface of each said rib and the top surface of each bottom planar member and the second and third fused surfaces are between the ends of each rib and two frustum connectors [FIG. 1, 12 and 22] of the first type. In one of the specific embodiments, the first type of rib [FIG. 1, 24] used as an outer wall is connected through two fused surfaces to two frustum connectors of the first type [FIG. 1, 12 and 22]. A right angle is formed between the top surface of said bottom planar member and the inner surface of the vertical side of said rib and the outer surface of said rib forms a right angle with the bottom surface of said bottom planar member. The inner ribs [FIG. 1, 25] of this first type have three fused surfaces, the first said fused surface is between the bottom surface of each said rib and the top surface of each said bottom planar member. The second and third fused surface are between the ends of each said rib and frustum connectors [ FIG. 1, 13, 15, 17, 19, and 21] of the second type. In one embodiment of our invention, two right angles are formed between the top surface of the bottom planar member and both vertical wall-like sides of said inner ribs.
The second said type is connected to the bottom surfaces of top planar members wherein said second type forms inner [FIG. 3, 56] and outer [FIG. 3, 57] ribs. Said outer ribs have three fused surfaces: The first said fused surface is between the top surface of each said rib and the bottom surface of the top planar member. The second and third said fused surfaces are between the ends of each said rib and a combination of frustum connectors of the first type and flanges. A right angle is formed between the bottom surface of the said top planar member and the inner surface of the vertical side of said rib. The outer surface of said rib forms a right angle with the top surface of the top planar member so that a continuous coplanar outer surface [FIG. 1, 52] is formed consisting of the surfaces of alternating outer ribs of said first and second types. Said inner ribs [FIG. 3, 56] have three fused surfaces: The first said fused surface is between the top surface of said rib and the bottom surface of the top planar member and the second and third said fused surfaces are between the ends of each said rib and a combination of flange pieces and frustum connectors of the second type. Right angles are formed between the bottom surface of said planar member and the two vertical wall-like surfaces of the said rib so that said vertical surfaces of said rib are coplanar with vertical surfaces of the first type of inner rib. It is to be noted that flange [FIG. 3, 23] described previously can be omitted. Further the overall appearance of the transverse inner ribs of the first and second type when aligned with one another is a continuous wall-like member divided into equal segments by frustum connectors. Said equal segments are inner ribs alternately of the first and second kind.
It should be noted that by having the longitudinal dimension of all frustum connectors (hereinbefore discussed) equal to the longitudinal dimension of all ribs will result in the embodiment that uses only ribs as connecting means. Note that this effect is approached by connectors [FIG. 1, 12 and 22] of the first type because the longitudinal dimension of said connectors are almost the same as the outer ribs [FIG. 1, 24] of the first type.
Our invention of a meat spacer tray also includes a more general embodiment to be described briefly. In the more general form, our meat spacer tray comprises a plurality of top rectangular planar members, a plurality of bottom rectangular planar members and a plurality of connecting means.
The top planar members have the longer sides extending longitudinally and have said members' top and bottom planar surfaces coplanar to one another, respectively. i.e. the top and bottom surfaces of one said member is coplanar to the corresponding surfaces of all other said members.
The bottom rectangular planar members have their longer sides extending longitudinally and have each of their corresponding top and bottom rectangular planar surfaces coplanar to one another respectively the top and bottom surfaces of one said member being coplanar to the corresponding surfaces of other said bottom members. The top and bottom planar members are adjacent to [as hereinbefore defined] one another. The arrangement of top and bottom planar members is such that they alternate with one another so that the next nearest member for top planar members is always one or more bottom planar members and vice versa. Also, in our more general invention, are a plurality of connectors extending between bottom planar members and top planar members to secure the relative positions of each top member with respect to said top member's nearest neighbor, at least one bottom planar member. The width of these connectors may be all of uniform size or they may vary. For example, if the connectors extended the whole length of the longitudinal side of the planar rectangular members then there would be no vertical holes [hereinafter described] but rather a solid wall-like structure. It is to be noted that the advantage of the present invention arises from its ability to permit free circulation of air so that it is a significant feature of our invention to have connectors running along the longitudinal edge of the bottom planar members whose width along the longitudinal edge is smaller than the total width of the longitudinal direction.
A plurality of top and bottom holes which have sides defining an axis in a horizontal direction and in a transverse direction to the longitudinal arise from having connectors which do not totally extend the longitudinal width. A plurality of holes having the following structural members for said holes sides: Sides of connectors transverse to the longitudinal direction, top surfaces and longitudinal side surfaces of the bottom planar members, and the bottom surfaces and longitudinal side surfaces of the top planar members.
In this more general structure, it is possible to incorporate ribs of the first and second type as described earlier to traverse the longitudinal direction of top and bottom planar members and thereby add structural strength to our invention.
The following use and method of manufacture is but one example and should not be unduly limiting. There are many variations on the invention herein disclosed which will be readily apparent to one skilled in the art.
EXAMPLE OF USE
Said meat spacer tray is currently being used in the quick freezing of meats wherein meat either packaged or not is placed upon one meat spacer, followed by a second spacer, which is placed upon said first layer of meat. Several layers of meat are thereby achieved.
It should be noted that the arrangement of meat is such that the meat spacer placed thereon is level.
The temperatures range that a meat spacer would be subject to in freezing varies 10° above 0°F to as much as 60°F below.
EXAMPLE OF METHOD OF MANUFACTURE
One method of manufacturing our meat spacer is given in U.S. Pat. No. 3,268,636 invented by Richard G. Angelli, Jr., filed July 1, 1963. There are a variety of foamable polymeric material indicated such as polyethylene, polypropylene, polystyrene, etc. which may be employed in the fabrication of our meat spacer tray. | A meat spacer tray of molded plastic for freezing and storing meat is disclosed wherein an open array of holes, ribs, and connectors permit free circulation of air around meats placed thereon and, also, will hold odd-shaped cuts of meat such as hams. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an electric gearshift mechanism for a change-speed gearbox of a motor vehicle.
2. Description of the Prior Art
An electric gearshift mechanism for change-speed gearboxes of motor vehicles is shown in German Patent 1 139 758 ('758). In the electric gearshift mechanism of the '758 patent, two separate electrical devices are required to accommodate two substantially mutually transverse shifting movements (R=rotation and L=linear) that are necessary. An electromagnet is provided for the rotary movement (R) engaging a lever arm. For the linear movement (L), an electric motor is provided. The motor has a threaded spindle which carries a nut. The nut is held fast against rotation and axially guided.
In the electric gearshift mechanism of the '758 patent, the rotary movement required for the preselection is furnished by an electromagnet, and the linear movement required for engagement is furnished by an electric motor. The preselection movement of the electromagnet enables one of three shift gates to be selected. The movement of the electric motor, the threaded spindle, and the nut make a controlled engagement movement possible through control of the speed of rotation of the electric motor. Two separate control devices are therefore required for these two electric gearshift mechanisms. The mechanism from the '758 patent meets the requirements of the change-speed gearbox, since the gearbox requires a rotary movement for the preselection of the shift gates, and a linear movement for the engagement of the gears.
When a linear movement is required for the preselection in the gearbox, and a rotary movement is required for the engagement, difficulties arise with regard to the desired controlled engagement movement of the different gears. This is particularly true when synchronizing devices are used in an automatic change-speed gearbox, in which case precise control of the variation of the force applied in the engaging movement during upshifts and downshifts is extremely desirable. The present invention endeavors to overcome these difficulties.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an improved electric gearshift mechanism in which both of the required shifting movements (R and L) are derived from the rotary movement of a threaded spindle. In such a gearshift mechanism, the force applied during the execution of both a rotary movement and a linear movement can be effected through a corresponding single control device for the electric motor driving the threaded spindle. Rotary movement (R) is derived from the threaded spindle by producing, through a clutch, a temporary, controlled non-rotatable connection between the threaded spindle and a linear guide means of a nut driven by the spindle. When the electric motor is correspondingly controlled, this temporary connection enables a desired variation in the applied force provided during the rotary movement.
The linear guide means for the nut may be in the form of a sliding sleeve mounted on the threaded spindle for limited axial and rotary movement. The sliding sleeve has radial clutch surfaces at its ends whereby the sliding sleeve can: Be held stationary by radial clutch surfaces provided on the reduction gearbox; or, Be connected non-rotatably to the threaded spindle by radial clutch surfaces provided on a clutch flange which is connected non-rotatably to the threaded spindle.
In one embodiment of the invention, the clutch surfaces are disposed immediately adjacent to magnet coils. In a second embodiment, the sliding sleeve has an annular groove at one end, engaging into which is a selector fork which can be actuated directly by the armature of an electromagnet. In a third embodiment of the invention, the linear guide means for the nut is in the form of a sliding sleeve mounted on the threaded spindle which is capable of limited axial and rotary movement. This sliding sleeve has clutch tooth systems at its ends through which said sleeve can alternately: (1) Be held stationary by a clutch tooth system provided on projecting sleeve fixed on the reduction gearbox; or, (2) Be connected non-rotatably to the threaded spindle by a clutch tooth system formed in the manner of a synchronizer cone. Furthermore, the clutch tooth system of the third alternative is provided on a clutch flange connected non-rotatably to the threaded spindle, and a portion of the sliding sleeve directly forms the armature of an electromagnet.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an embodiment of an electric gearshift mechanism according to the invention.
FIG. 2 shows a further embodiment of an electric gearshift mechanism according to the invention.
FIG. 3 shows a third embodiment of an electric gearshift mechanism according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An electric gearshift mechanism for a change-speed gearbox of a motor vehicle consists of a direct current motor 1 having a reduction gearbox 2 flanged directly onto it an output shaft 3. Associated with the reduction gearbox 2 is a position or angle sensor 4 which, in combination with an appropriate electronic control device, monitors the control of the electric motor 1. The output shaft 3 is connected to a threaded spindle 5 in a manner not shown. Alternatively, output shaft 3 is integral with threaded spindle 5. A nut 6 is mounted on the threaded spindle 5. The nut 6 carries a radially projecting selector finger 7. Further, nut 6 is held fast against rotation but axially movable within a linear guide 8. The linear guide 8 may be formed in a particularly simple manner by providing an elongate slot 9 in a tubular sliding sleeve 10. Sleeve 10 then receives nut 6 in its interior.
A magnet coil 11 is provided adjacent the end of the threaded spindle 5, connected to the reduction gearbox 2. Coil 11 is provided with a radial clutch surface 12 which can cooperate with a correspondingly formed counter clutch surface 13 provided on the end face of the sliding sleeve 10. On the two clutch surfaces 12 and 13, radial flat tooth systems are provided, which, with a minimal stroke of the sliding sleeve 10, form a positive connection to the magnet coil 11 and consequently to the fixed reduction gearbox 2. At the other, free end 14 of the threaded spindle 5, a clutch flange 15 is connected non-rotatably to the threaded spindle 5 by means of a key 16 and a screw 17. A second magnet coil 18 is fitted non-rotatably on the clutch flange 15 and is provided with a radial clutch surface 19. The clutch surface 19 can cooperate with a correspondingly formed radial clutch surface 20 on the opposing end of the sliding sleeve 10.
In the embodiment shown in FIG. 1 the sliding sleeve 10 is supported at one end by the end of the threaded spindle 5 and at the other end by the outer periphery of the nut 6. For the sake of clarity, sleeve 10 is shown in a middle position where it resides only for a short time in each changeover phase. The sliding sleeve 10 is displaced to the right by switching on magnet coil 18. In this way, radial clutch surfaces 19 and 20 produce a non-rotatable connection between the threaded spindle 5 and the sliding sleeve 10 via the clutch flange 15. The longitudinal slit 9 guides the selector finger 7 along in a rotary movement R whereby the selector finger 7 preselects one of several selector gates of the change-speed gearbox.
Immediately after the rotary movement to preselect a gate, magnet coil 18 is switched off and magnet coil 11 is turned on. Thus, the sliding sleeve 10 is moved to the left, whereby the radial clutch surfaces 13 and 12 produce a non-rotatable connection with the fixed housing of the reduction gearbox 2. When the threaded spindle 5 is turned in a controlled manner, an axial, linear movement L is effected in the nut 6. This moves the selector finger 7 in the longitudinal slit 9, thus allowing the engagement of a gear.
It can readily be seen that, by appropriate switching over between the two magnet coils 11 and 18 and appropriate control of the electric motor 1, controlled angular movements R and corresponding controlled linear movements L of the selector finger 7 can be obtained. By means of an electronic controller for the electric motor as is well known in the art, the variation in the force applied during the movements being carried out can be very precisely controlled and monitored.
In the embodiment shown in FIG. 2, the same components are given the same reference numerals, and components which are functionally the same but structurally modified are given reference numerals with an added prime notation. Differences between the first and second embodiments include sliding sleeve 10', clutch flange 15' and the arrangement of the magnet coils. More specifically, sliding sleeve 10' is provided with an annular groove 21 on its end adjacent the reduction gearbox 2, in which a shifter fork 22 engages the sleeve 10'. The shifter fork 22 carries the armature 23 of a solenoid 24, which is urged out of its coil by means of a spring 25. Similarly, armature 23 is drawn back into the solenoid 24, to the left as seen in FIG. 2, when the coil is energized. Thus, when the solenoid 24 is not activated, the spring 25 moves the sliding sleeve 10' towards the clutch flange 15', thereby forming a non-rotatable connection via the radial clutch surfaces 19 and 20. Thus, by rotating the threaded spindle 5, a rotary movement R of sleeve 10' can be effected.
When the solenoid 24 is activated, the armature 23 is drawn into the coil and the shifter fork 22 slides the sliding sleeve 10' to the left, as seen in FIG. 2. This action forms a non-rotatable connection with the fixed housing of the reduction gearbox 2 by way of the radial clutch surfaces 12 and 13. Thus, when the threaded spindle 5 rotates, the sliding sleeve 10' is restrained from rotation and the rotation of the threaded spindle 5 leads to a linear movement of the nut 6. Consequently, the selector finger 7 carries out a desired linear movement L for engagement of a gear speed.
In the embodiment shown in FIG. 3, corresponding components are again similarly designated, and components which are functionally the same but structurally modified are given reference numerals with an added double prime notation. A flange 26 with a projecting sleeve 27 is arranged concentrically with the end of threaded spindle 5. Projecting sleeve 27 carries a magnet coil 28. The sliding sleeve 10" is provided at its left hand end with an extension 29 which extends into the projecting sleeve 27. A coil spring 30 inside the projecting sleeve 27 urges the sliding sleeve 10" to the right so that a non-rotatable connection between the sleeve 10" and the clutch flange 15" is again produced. In this embodiment, however, the radial clutch surfaces 19" and 20" are provided with a tooth system like those in a synchronizer cone clutch. When the sliding sleeve 10" is pushed to the right by the spring 30, a non-rotatable connection between the threaded spindle 5 and the sliding sleeve 10" again results, and a rotary movement R of sleeve 10" is again performed.
A sleeve extension 29 is provided at the second end of the sliding sleeve 10". Adjacent this sleeve extension 29, and on an annular shoulder 31 of the sliding sleeve 10", a clutch tooth system 13" is formed in a manner similar to a known synchronizer cone clutch. In a similar manner, a clutch tooth system 12" is formed on the projecting sleeve 27. When the magnet coil 28 is energized, the sleeve extension 29 of the sliding sleeve 10" acts as the armature of this solenoid arrangement and draws the sliding sleeve 10" to the left, as seen in FIG. 3. This action forms a non-rotatable connection between the flange 26 fixed to the reduction gearbox 2 and the projecting sleeve 27 and the sliding sleeve 10". Consequently, a rotation of the threaded spindle 5 again leads to a linear movement of the nut 6 and the selector finger 7 in the linear direction L.
The embodiments of an electric gearshift mechanism according to the invention shown in FIGS. 1, 2, and 3 only constitute examples of advantageous embodiments. The form of the linear guide means for the nut and the form of the radial clutch surfaces and their positively engaging clutch tooth systems can be varied in many suitable ways by one skilled in the art without departing from the spirit and scope of the present invention. Although a preselection movement for shifting a change-speed gearbox is always described herein with a radial movement and an engaging movement with a linear movement, it is wholly within the spirit and scope of the present invention for the preselection movement to take place by a linear movement and the engaging movement of the change-speed gearbox be performed with a radial movement. The essence and particular advantage of the present invention are that the two movements, i.e. both the rotary movement and the linear movement, can be controlled very precisely and variably. That is, the movements can be controlled with respect to the variation of the force they apply by deriving them directly from the threaded spindle driven by a single electric motor. Thus, the corresponding operation of synchronizing devices in a change-speed gearbox can take place with correspondingly adapted forces.
Although the preferred embodiments of the present invention have been disclosed, various changes and modifications may be made without departing from the scope of the invention as set forth in the appended claims. | An electric gearshift mechanism for a change-speed gearbox of a motor vehicle with selector gates has an electric motor and a gear shifting member. The gear shifting member can be moved in two substantially mutually transverse shifting movements. The gear shifting member includes a threaded spindle having an axis of rotation drivably connected to the motor carrying a nut having a finger for preselecting selector gates. A linear guide conducts the nut along the axis and a clutch rotatably connects the nut and the spindle. | 8 |
BACKGROUND OF THE INVENTION
[0001] This invention relates generally to control systems for appliances, and more particularly, to a control system for a refrigerator.
[0002] Known household appliances are available in various platforms having different structural features, operational features, and controls. For example, known refrigerator platforms include side-by-side single and double fresh food and freezer compartments, and vertically oriented fresh food and freezer compartments including top mounted freezer compartments, and bottom mounted freezer compartments. Conventionally, a different control system may be used in each refrigerator platform. For example, a control system for a side-by-side refrigerator typically controls the freezer temperature by controlling operation of a compressor and controls the fresh food compartment through the operation of a mullion damper located between the fresh food compartment and the freezer compartment, a fresh food fan and a variable or multi-speed fan-speed evaporator fan. Top mount refrigerators and bottom mount refrigerators however, are available with and without a mullion damper, the absence or presence of which consequently affects the refrigerator controls.
[0003] Other major appliances, including dishwashers, washing machines, dryers and ranges, are available in various platforms and employ different control schemes.
[0004] Known electronically controlled appliances typically employ a dedicated connection between a controller and a plurality of peripheral devices, including but not limited to sensors to monitor various operating conditions of the appliance. Typically, analog signals are transmitted between the sensors and the controller. These analog signals, however, are vulnerable to electrical interference, which can compromise performance of the appliance. To reduce electrical interference, additional electronic circuitry may be employed, but only at increased complexity and cost of the control scheme. Further, ever-expanding appliance features entail relatively sophisticated control schemes and many electrical connections to place all the peripheral devices in communication with the controller. A large number of electrical connections not only increases assembly costs, but presents a possible defect in manufacturing or possibility of failure in use.
BRIEF SUMMARY OF THE INVENTION
[0005] According to an aspect of the present invention a control system for an appliance includes a plurality of peripheral devices, a plurality of sensors and a controller. A first communications/DC power bus is coupled to the plurality of sensors and peripheral devices and coupled to the controller. A second communications/AC power bus is coupled to the plurality of sensors and peripheral devices and coupled to the controller. Wherein the controller is configured to receive data from the sensors over either communications bus and transmit control operations to the peripheral devices based on the data.
[0006] According to another aspect of the present invention a refrigerator comprises a control system for an appliance which includes a plurality of peripheral devices, a plurality of sensors and a controller. A first communications bus provides DC power to peripheral devices and is coupled to the plurality of sensors and coupled to the controller. A second communications bus provides AC power to peripheral devices and is coupled to the plurality of of sensors and peripheral devices and coupled to the controller. Wherein the controller is configured to receive data from the sensors over a communications bus and transmit control operations to the peripheral devices based on the data.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a perspective view of a refrigerator.
[0008] FIG. 2 is a perspective view of the refrigerator of FIG. 1 with the doors in a open position.
[0009] FIG. 3 is a block diagram of a distributed low voltage bus system of the refrigerator of FIG. 1 according to an aspect of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0010] It is contemplated that the teaching of the description set forth below is applicable to all types of appliances, including but not limited to refrigerators but include a standalone refrigeration unit or may be connected to ranges, microwaves, and other appliances. The present invention is therefore not intended to be limited to any particular refrigeration device or configuration of cooling circuit 100 for the temperature controlled medium.
[0011] FIGS. 1 and 2 illustrate a side-by-side refrigerator 100 including a fresh food compartment 102 and freezer compartment 104 . Freezer compartment 104 and fresh food compartment 102 are arranged in a bottom mount configuration where the freezer compartment 104 is below the fresh food compartment 102 . The fresh food compartment is shown with French opening doors 134 and 135 . However, a single door may be used. Door or drawer 132 closes freezer compartment 104 .
[0012] The fresh food compartment 102 and freezer compartment 104 are contained within an outer case 106 . As shown in FIG. 2 , Mullion 114 separates the fresh food compartment 102 and the freezer compartment 104 .
[0013] Door 132 and doors 134 , 135 close access openings to freezer and fresh food compartments 104 , 102 , respectively. Each door 134 and 135 is mounted by a top hinge 136 and a bottom hinge 137 to rotate about its outer vertically oriented edge between an open position, as shown in FIG. 2 , and a closed position shown in FIG. 1 closing the associated storage compartment.
[0014] In accordance with known refrigerators, refrigerator 100 also includes a machinery compartment (not shown) that at least partially contains components for executing a known vapor compression cycle for cooling air in the compartments. The components include a compressor, a condenser (not shown), an expansion device (not shown), and an evaporator (not shown) connected in series and charged with a refrigerant. The evaporator is a type of heat exchanger that transfers heat from air passing over the evaporator to a refrigerant flowing through the evaporator, thereby causing the refrigerant to vaporize. The cooled air is used to refrigerate one or more fresh food or freezer compartments via fans (shown schematically in FIG. 3 as 534 ). Collectively, the vapor compression cycle components in a refrigeration circuit, associated fans, and associated compartments are referred to herein as a sealed system. The construction of the sealed system is well known and therefore not described in detail herein, and the sealed system is operable to force cold air through the refrigerator 100 .
[0015] FIG. 3 illustrates an exemplary low voltage bus system 500 with controller 502 in accordance with one embodiment of the present invention. Controller 502 can be used, for example, in refrigerators, freezers and combinations thereof, including but not limited to refrigerator 100 (shown in FIGS. 1 and 2 ). It is recognized, however, that controller 502 is easily adaptable to control other types of appliances, including but not limited to dishwashers, washing machines, dryers and ranges in light of the principles set forth below.
[0016] Controller 502 includes a diagnostic port 562 and a human machine interface (HMI) board 564 coupled to a main control board 566 by an interprocessor communications bus 568 . HMI board 564 is coupled to a HMI display device 200 , which may include a touch screen or other input as well as a liquid crystal display for outputting features and parameters to a user. It should be realized that HMI display device may be any user input such as buttons, switches, keyboard or mouse as well as the above mentioned touch screen or any other input means. Additionally, the output feature may be any output means including the above referenced LCD screen as well as, light emitting diode signals, or any other known display means.
[0017] Main control board 566 , human machine interface (HMI) board 564 are coupled to a power supply 632 which receives an AC power from a protection unit 634 . Protection unit 634 may sense and protect the unit from current leakage or arcing using ground fault or arc fault technology. The protection unit may communicate with and/or be controlled by the main control board 566 . The input voltage may be 90-265 Volts AC, 50/60 Hz signal.
[0018] Main control board 566 monitors and manages the DC input and output bus 520 and the AC input and output bus 540 as well as power supply current and voltage, brownout detection, compressor cycle adjustment, analog time and delay inputs where the analog input is coupled to an auxiliary device such as a clock or finger pressure activated switch, analog pressure sensing of the compressor sealed system for diagnostics and power/energy optimization. Further input functions include external communication via power line, infrared detectors or sound detectors, human machine interface display dimming based on ambient light, adjustment of the refrigerator to react to food loading and changing the air flow/pressure accordingly to ensure food load cooling or heating as desired, and altitude adjustment to ensure even food load cooling and enhance pull-down rate of various altitudes by changing fan speed and varying air flow.
[0019] A plurality of digital inputs 522 , 524 , 526 , 528 , 530 , 532 , 534 , 536 and 538 (collectively 522 - 538 ) are disclosed in FIG. 3 . Digital devices 522 - 538 correspond to, but are not limited to, a condenser fan speed, an evaporator fan speed, a door detector 198 , dispenser ice chute obstruction detection, light emitting diodes and various thermisters. These devices may function as inputs or outputs to the microprocessor and may draw DC power from the bus 520 .
[0020] Main control board 566 also is coupled to an AC input/output bus 540 for managing various AC peripheral devices 542 - 548 . AC input/output bus 540 may be separately wired (not shown) or sent over the conditioned power supply wires, as shown. AC peripheral devices 542 - 548 may include but are not limited to a crusher solenoid, an auger motor, a water dispenser valve, a compressor control, a defrost heater, the operating speed of a variable speed condenser fan, a fresh food compartment fan, an evaporator fan, and a quick chill system feature pan fan.
[0021] Each of the DC peripheral devices 522 - 538 and AC peripheral device outputs 542 - 548 are assigned a unique address by the main control board 566 . By utilizing information from each of the inputs 522 - 538 the main control board 566 may manipulate the various peripheral devices 542 - 548 or 522 - 538 . Manipulation may include safety shutoff of various features, energy efficient operation, and lighting or other human interface programming and control or other features or controls required by the particular application.
[0022] While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims. | According to an aspect of the present invention a control system for an appliance includes a plurality of peripheral devices and a plurality of sensors and a controller. A first communications/DC power bus is coupled to the plurality of sensors and peripheral devices and coupled to the controller. A second communications/ac power bus is coupled to the plurality of sensors and peripheral devices and coupled to the controller. Wherein the controller is configured to receive data from the sensors over the either communications bus and transmit control operations to the peripheral devices based on the data. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
The present application is a national phase entry under 35 U.S.C. §371 of International Application No. PCT/SE2012/000099 filed Jun. 28, 2012, published in English, which claims priority from SE 1150621-9, filed Jul. 1, 2011, all of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a feed screw for feeding lignocellulose material to a rotary grinder. Specifically, the present invention relates to a feed screw arrangement for feeding lignocellulose material to a grinding zone of a rotary grinder.
BACKGROUND OF THE INVENTION
A rotary grinder may be used for grinding lignocellulose material, such as wood chips, into pulp. Such a grinder comprises two opposed grinding discs, which both include a peripheral ring-formed grinding surface between which the chips are to be ground. Normally, one of these discs is stationary, i.e., the stator disc, and the other is rotary, i.e., the rotor disc. It is, however, also possible to use two counter-rotating grinding discs. In a conventional grinder, where one disc is stationary, an inlet is arranged through the axial center of the stator disc.
Conventionally the chips are conveyed towards the peripheral grinding zone, i.e., the gap between the opposed surfaces of the discs, by means of a feed screw. The feed screw of the feed screw arrangement is normally arranged in the axial direction of the grinder, such that the chips are conveyed in the axial direction through the center of the stator disc and towards the center of the rotor disc. Hence, because the chips are ground in the peripheral grinding zone between the grinding discs, the chips will have to be directed in the radial direction towards the peripheral grinding zone. This redirecting of the chips is normally accomplished by means of plates that are arranged crosswise on the central part of the rotor. The plates may be arranged such that they form a star or a cross which is centered on the rotor disc. The idea is that when the chips hit one of the plates they will be struck in the radial direction towards the peripheral grinding zone.
In reality, it has been proven difficult to control the direction of the chips, which are just as often thrown back into the feed screw as they are thrown in the radial direction towards the grinding zone. Normally, the path of a chip is completely unpredictable and often it bounces back and forth several times before it reaches the grinding zone.
Hence, there is a need for a new arrangement for feeding the chips towards the peripheral grinding zone. Specifically, the arrangement should provide a more predictable feeding of the chips, without the disadvantages of the prior art.
One object of the present invention is to provide an alternative feeding arrangement for feeding lignocellulose material such as wood chips to a grinder. Another object of the present invention is to improve the feeding of lignocellulose material in such a way that it is fed to the peripheral grinding zone of the grinder in a more predictable manner.
SUMMARY OF THE INVENTION
In accordance with the present invention, these and other objects have now been realized by the invention of a feed screw for feeding lignocellulosic material to a rotary disc refiner comprising a pair of opposed grinding surfaces, the feed screw comprising at least one peripheral thread for feeding the lignocellulosic material axially along the feed screw towards the rotary disc refiner, the at least one peripheral thread including an upstream end and a downstream end corresponding to the pair of opposed grinding surfaces whereby the feed screw feeds the lignocellulosic material from the upstream end towards the downstream end through the center of one of said pair of opposed grinding surfaces, the downstream end of the at least one peripheral thread including an angled end member disposed at an angle with respect to the at least one peripheral thread whereby the lignocellulosic material is redirected in a radial direction as it leaves the at least one peripheral thread. In a preferred embodiment, the at least one peripheral thread includes a predetermined pitch angle upstream of the angled end member, and the angled end member includes an increased pitch angle compared to said predetermined pitch angle.
In accordance with one embodiment of the feed screw of the present invention, the angled end member comprises a straight plate fixed to the at least one peripheral thread at an abrupt angle with respect thereto.
In accordance with another embodiment of the feed screw of the present invention, the at least one peripheral thread includes a predetermined pitch angle upstream of the angled end member, and the angled end member includes a smoothly curved surface providing a smoothly increasing pitch angle compared to said predetermined pitch angle.
In accordance with another embodiment of the feed screw of the present invention, the angled end member comprises a continuation of the at least one peripheral thread.
In accordance with another embodiment of the feed screw of the present invention, the angled end member is disposed on a feeding side of the at least one peripheral thread.
In accordance with another embodiment of the feed screw of the present invention, the angled end member includes at least one lateral rim preventing the lignocellulosic material from slipping sideways with respect to the angled end member.
In accordance with another embodiment of the feed screw of the present invention, the feed screw comprises a pair of peripheral threads, each of the pair of peripheral threads include an angled member.
In accordance with another embodiment of the feed screw of the present invention, the feed screw includes an outer cylindrical pipe, the feed screw being disposed within the outer cylindrical pipe.
In accordance with the present invention, a grinder has also been provided comprising a pair of opposed grinding discs and including a feed screw for feeding lignocellulosic material to the grinder, the feed screw including an outer cylindrical pipe whereby the feed screw is disposed within the outer cylindrical pipe, the feed screw including the outer cylindrical pipe disposed extending through the center of the pair of opposed grinding surfaces and into a feed zone between the pair of opposed grinding surfaces, the feed screw including at least one peripheral thread for feeding the lignocellulosic material axially along said feed screw towards the feeding zone between the pair of opposed grinding surfaces, the at least one peripheral thread including an upstream end and a downstream end corresponding to the feeding zone between the pair of opposed grinding surfaces, the downstream end of the at least one peripheral thread including an angled end member disposed at an angle with respect to the at least one peripheral thread whereby the lignocellulosic material is redirected in a radial direction into the feeding zone. In a preferred embodiment, one of the pair of opposed grinding surfaces comprises a stator disc and the other the pair of opposed grinding surfaces comprises a rotor disc, the feed screw and the cylindrical pipe being disposed through the center of the stator disc.
The present invention relates to a feed screw for feeding lignocellulose material to a rotary disc grinder comprising two opposed grinding discs, the feed screw comprising at least one peripheral thread for feeding the lignocellulose material in an axial feeding direction, the peripheral thread having an upstream end from which lignocellulose material is to be fed towards a downstream end, which is to be arranged through the center of one of the grinding discs such that it reaches into a feeding zone between the two opposed grinding discs, wherein the downstream end of the peripheral thread comprises an angled end part, which is arranged at an angle with respect to the peripheral thread so as to re-direct the lignocellulose material in the radial direction as it leaves the peripheral thread.
The feed screw can be a separate machine or mounted on the rotary grinder. Specifically, the present invention also relates to a feed screw arrangement including such a feed screw and to a grinder including such a feed screw arrangement.
With the feed screw according to the present invention an improved feeding of the lignocellulose material is achieved in that the lignocellulose material is fed to the peripheral grinding zone of the grinder in a more predictable manner and with a reduced risk of being rejected from the grinding zone.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention, and further objects and advantages of it, is best understood from the following detailed description with reference to the appended drawings, of which:
FIG. 1 is a side, elevational, sectional view of a feeding zone of a grinder with a feed screw arrangement according to one embodiment of the present invention;
FIG. 2 is a side, perspective view of the feed screw shown in FIG. 1 ; and
FIG. 3 is a side, evelational, parital sectional view of a feed screw according to another embodiment of the present invention.
DETAILED DESCRIPTION
The arrangement shown in FIG. 1 includes a grinder 10 with a stator disc 11 and an opposed rotor disc 12 . The stator disc 11 and the rotor disc 12 define a peripheral grinding zone between them. The peripheral grinding zone includes a pre-grinding zone and a main grinding zone. The pre-grinding zone is formed between two inner opposed grinding segments 13 and 14 of the stator 11 and rotor 12 , respectively. Outside this pre-grinding area, in the radial direction, the main grinding zone is formed between two outer opposed grinding segments 15 and 16 of the stator 11 and rotor 12 , respectively.
Chips or any other lignocellulose material such as pulp, fibers, straws are arranged to be conveyed in a feeding direction to the peripheral grinding zone by means of a feed screw arrangement 17 comprising a feed screw 18 that is axially arranged inside a cylindrical pipe 19 and rotates around an axial shaft 20 . In this description the term chips is used to denote all possible lignocellulose materials that may be fed by the feed screw. The present invention is, however, not limited to the feeding of a specific material.
In the shown embodiments the feed screw 18 comprises a peripheral thread 23 or a spiral (helix) with a hollow inner section. The peripheral thread 23 is connected to the axial shaft 20 by means of connectors 21 , which in the shown embodiment is constituted of spoke-like arms. Another possible design of the connectors is to use plates that may be arranged alongside the shaft. The arrangement with a partly hollow interior between the axial shaft 20 and the peripheral thread 23 allows fluid, such as gas or steam, to pass opposite the feeding direction in which the lignocellulose material is conveyed.
The feed screw 18 is arranged to rotate at about 300-2000 rotations per minute. This relatively high rotational speed contributes to the formation of centrifugal forces that assures that the chips will be kept close to the inside wall of the cylindrical pipe 19 , such they will not end up inside of the width of the peripheral thread 23 . Hence, the chips will be conveyed into the grinding zone by the feed screw 18 in close contact with both the peripheral thread 23 and the inside of the cylindrical pipe 19 .
The peripheral thread 23 of the feed screw 18 may have the same pitch or pitch angle throughout the whole extension of the cylindrical pipe 19 . The pitch angle is in this application defined as the angle of peripheral thread 23 with respect to the normal plane of the axial shaft 20 . Hence, the pitch angle may theoretically be between 0° and 90°, where a pitch angle of 0° results in no axial feeding at all, and where the feeding velocity will increase with an increasing pitch angle.
The optimal pitch angle is, however, dependent of the rotational speed of the feed screw 18 . Further, it is dependent from the diameter of the feed screw 18 and the cylindrical pipe 19 . The higher the pitch angle of the peripheral thread 23 , the higher the feeding velocity of the chips. The chips are pushed in the axial direction by the action of the peripheral thread 23 . The rotation of the peripheral thread 23 also gives the chips a push in the angular direction, due to the friction between the peripheral thread 23 and the chips. Further, as indicated above, due to the relatively high rotating speed of the peripheral thread 23 the chips will be exposed to centrifugal forces that will keep them in close contact with the inside of the cylindrical pipe 19 .
In accordance with the present invention, the feed screw 18 includes an angled end part 22 for releasing the chips in the radial direction towards the peripheral grinding zone. The angled end part 22 is angled so as to redirect the chips, which are conveyed in a mainly axial direction inside the cylindrical pipe 19 , to a partly radial direction towards the grinding zone as they exit the cylindrical pipe. This is achieved in that the angled end part 22 is arranged at an angle with respect to the peripheral thread 23 .
The re-directing of the chips is not such that the chips will be re-directed so as to be conveyed in the radial direction only. Namely, the chips have an inherent kinetic energy in both the axial and the angular direction as they reach the angled end part 22 and this kinetic energy will not be totally lost. Part of the axial/angular kinetic energy will, however, be transferred into kinetic energy in the radial direction. The actual re-direction of the chips, or their kinetic energy, is dependent on the shape and parameters of the actual feed screw arrangement 17 . The aim of the re-direction of the chips is to give them enough kinetic energy in the radial direction so as to direct them towards the gap between the discs 11 and 12 .
Further, the angled end part 22 may be arranged so as to re-direct the chips radially inwards, such that the chips will be directed towards the gap between the discs 11 and 12 at the radial opposite side, or radially outwards, such that the chips will be directed towards the same gap at the same radial side from which they are released. The chips will, however, also be conveyed in a direction that has both an angular and an axial component.
The angle of the angled end part 22 should, however, be such that the chips will receive a push in the radial direction. This may be achieved in many different manners, whereof the shown embodiments represent two examples. Generally, the angled part 22 contributes to giving the peripheral thread 23 a momentary increased pitch angle, such that the chips will be redirected from the feeding direction they have inside the cylindrical pipe 19 .
In the first embodiment shown in FIGS. 1 and 2 the angled end part 22 consists of a straight plate that is fixed to the peripheral thread 23 at an abrupt angle with respect to the feed screw. In this context an abrupt angle indicates that the angle of the end part 22 with respect to the peripheral thread 23 is achieved in one single point, such that pitch angle of the peripheral thread 23 gets a sudden increase by means of the angled end part 22 . The pitch angle thus has one value upstream of the point of the abrupt angle and another, higher value, downstream of the same point. Due to the abrupt angle the chips will bounce on the angled end part 22 towards the peripheral grinding zone.
A second embodiment of the angled end part 22 is shown in FIG. 3 . In this embodiment the end part 22 has a smoothly curved surface arranged to provide a smooth transition for the chips, such that the chips will be swung towards the grinding zone. In this embodiment the increase of the pitch angle with respect to the peripheral thread 23 is smoothly increasing, instead of having an abrupt angle. An advantage of this embodiment is that the release angle of the chips will be easier to control, due to the fact that a more predictable trajectory of the chips may be achieved.
Both embodiments of the inventive angled end part may be easily implemented in an existing feeding arrangement, e.g., by welding a plate to the peripheral thread or by attaching it by means of an angle bar 26 on the peripheral thread 23 . The peripheral thread 23 has a feeding side 27 which is in contact with the chips as they are fed through the cylindrical pipe 19 . Naturally, the angled end part 22 is attached to this feeding side 27 of the peripheral thread 23 .
Another possible way of implementing the angled end part 22 , regardless of the embodiment, is to attach it as a continuation of the end of the peripheral thread 23 , e.g., downstream with respect to the peripheral thread 23 .
Regardless of which type of angled end part 22 is used, the end part 22 may be furnished with lateral rims 24 or edges in order to direct the chips in a more predictable way and to prevent the chips from sliding laterally on the end part 22 such that some part of the effect provided by it may be lost. The edges may be either rounded or straight. The lateral rims 24 may be arranged at both lateral sides of the angled end part 22 or at just one lateral side of it, depending on the forces acting in the specific embodiment. In the embodiments shown in FIGS. 1 and 3 the lateral rims 24 are arranged at a straight angle of about 90° with respect to the main part of the angled end part 22 . Other angles are however possible.
Above, specific embodiments of the invention have been described with reference to the schematic drawings. The invention is however not limited to either of these. Instead, the invention is only limited by the scope of the following claims. | A feed screw for feeding lignocellulosic material to a rotary disc refiner is disclosed. The feed screw includes at least one peripheral thread for feeding the lignocellulosic material axially towards the disc refiner and the feed screw feeds the lignocellulosic material from its upstream end towards its downstream end through the center of the opposed grinding surfaces of the disc refiner, the downstream end of the peripheral thread including an angled end part disposed at an angle with respect to the peripheral thread such that the lignocellulosic material is redirected in a radial direction as it leaves the end of the peripheral thread. | 3 |
BACKGROUND OF THE INVENTION
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
Not Applicable
1. Field of the Invention
The present invention relates to ocarinas and other vessel flutes.
2. Prior Art
Prized for their simplicity, portability, and pure tone, the musical instruments that developed into modern ocarinas have existed for ages. Since their earliest significant modern improvement, the utilization of a modern tuning in conjunction with a linear fingering pattern, the ocarina has been considered suitable for performing western music. Another notable improvement to the ocarina was the development of a four-hole tuning system, commonly called and hereinafter referred to as crossed-fingering. See, for example, U.S. Pat. No. 3,815,466. This tuning allows the user to perform the notes of a one octave major scale using only four tone holes. However, even with the addition of thumbholes, these ocarinas have been limited to the range of eleven notes of a major scale and cannot accurately perform all accidentals within the range. This inability to perform all accidentals was partially overcome by dividing the smallest tone hole into two substantially equal-sized holes, such holes hereinafter referred to as a split hole. This split hole functioned differently than subholes common on ocarinas with linear fingerings in that they are stopped together to function as one hole and using them does not lower the pitch below the tonic of the scale. Stopping only one of theses two holes would allow performance of one semitone above the tonic. However, one could still not accurately perform three semitones above the tonic. In U.S. Pat. Application Publication # US 2007/0157792 A1, the disclosure of which is incorporated herein by reference, is disclosed an ocarina that utilizes two subholes and an additional finger hole to allow a cross-fingered ocarina to perform all accidentals and a range of thirteen notes of a major scale. A subhole is a tonehole that is typically left open, but is stopped when the performer desires to play below the tonic note. However, this prior art mentions and depicts only an ocarina that utilizes subholes that specifically are adjacent to the first two standard toneholes. Since this requires the subholes to be operated with the same fingers that must also operate the adjacent toneholes, this arrangement would likely prove difficult for many performers.
Despite many improvements, the physical properties of ocarinas generally limit them to a range of thirteen notes of a major scale. That range was eventually expanded by adding a second chamber, making two ocarinas with differing fundamental pitches into one instrument. The range of a two-chambered ocarina has been limited to two octaves plus two notes. A two-chambered cross-fingered ocarina has been limited to a range of two octaves.
There is in existence two separate two chambered transverse ocarinas wherein the higher chamber utilizes a thumbhole. However, in both cases, the use of the thumbhole does not extend the range of the instrument beyond the common range, and the thumbhole does not raise the pitch more than one tone. The thumbholes of these ocarinas do nothing unexpected, as they function like any other tonehole.
While the addition of a third chamber has increased the range of ocarinas to one note less than three octaves, this has also increased costs of production, size, weight, and difficulty of use.
SUMMARY
The present invention includes ocarinas that have their musical ranges expanded by novel methods of construction and tuning. The present invention also includes ocarinas that permit more accurate performance of accidentals.
The present invention comprises ocarinas with one or more chambers utilizing an enhanced cross-fingering having subholes and/or split holes, and multi-chambered ocarinas having a higher chamber or chambers utilizing an enhanced linear fingering pattern. The present invention allows greater possibilities of musical expression to the performer and a lessened level of difficulty in performing.
A further advantage of the invention is that it enables a performer to use a single chamber of a cross-fingered ocarina to perform thirteen notes of a major scale, including all accidentals, in a simplified manner.
Advantages of multi-chamber ocarinas constructed according to the invention are that they utilize more fully the range of each chamber, which renders the use of a third chamber unnecessary to achieve a comparable note range. A further advantage of the invention is that it allows for the construction of ocarinas that are lighter, smaller, more portable, and less costly to produce than other ocarinas with comparable note ranges.
DRAWING FIGURES
FIG. 1A is an elevation view of a cross-fingered ocarina according to the invention.
FIG. 1B is a fingering chart of the ocarina depicted in FIG. 1A .
FIG. 2A is an elevation view of a cross-fingered ocarina according to the invention.
FIG. 2B is a fingering chart of the ocarina depicted in FIG. 2A .
FIG. 3A is an elevation view of a two-chambered cross-fingered ocarina according to the invention.
FIG. 3B is a fingering chart of the lower chamber of the ocarina depicted in FIG. 3A .
FIG. 3C is a fingering chart of the higher chamber of the ocarina depicted in FIG. 3A .
FIG. 4A is an elevation view of a two-chambered linear-patterned ocarina according to the invention.
FIG. 4B is a fingering chart of the higher chamber of the ocarina depicted in FIG. 4A .
FIG. 5A is an elevation view of a two-chambered linear-patterned ocarina according to the invention.
FIG. 5B is a fingering chart of the higher chamber of the ocarina depicted in FIG. 5A .
FIG. 6A is an elevation view of a three-chambered linear-patterned ocarina according to the invention.
FIG. 6B is a fingering chart of the middle chamber of the ocarina depicted in FIG. 6A
FIG. 7A is an elevation view of a three-chambered linear-patterned ocarina according to the invention.
FIG. 7B is a fingering chart of the middle chamber of the ocarina depicted in FIG. 7A
FIG. 7C is a fingering chart of the middle chamber of a variation of the ocarina depicted in FIG. 7A .
DESCRIPTION
In order that the above-recited advantages and features of the invention may be thoroughly understood, a more specific and detailed description of the invention summarized above will be rendered by reference to the accompanying drawings. It is to be understood that these drawings provide only selected embodiments of the invention and are not therefore to be considered limiting of its scope. Also, the skilled artisan would understand that the invention can be practiced without employing these specific details. Indeed, the spirit of the invention can still be practiced while modifying the illustrated instruments. With reference to FIG. 1A , an ocarina 1 comprises a hollow body 10 which includes an airway 11 for directing an air stream against a voicing 12 , thereby generating the sound of the instrument. The ocarina 1 includes a plurality of toneholes 100 that are stopped or unstopped to alter the pitches the instrument produces. The embodiment of a cross-fingered ocarina depicted includes a split tonehole 101 that, when stopped, performs the normal function of the second smallest tonehole of typical cross-fingered ocarinas. The second smallest tonehole common in prior art must be replaced with the split tonehole 101 to achieve the improvement found in the embodiment. The smaller of the holes that make up the split tonehole 101 is sized to alter the pitch of the instrument by one semitone when performing any pitch within four semitones above the tonic. Thereby the user may perform the pitch one semitone above the tonic by unstopping the smaller hole of the split tonehole 101 , and also may perform the pitch three semitones above the tonic by unstopping the smaller hole of the split tonehole 101 and the smallest of the standard toneholes 100 . In this manner the performer overcomes the inability of cross-fingered ocarinas of the prior art using a split tonehole to provide an accurate means of performing three semitones above the tonic.
As depicted, a cross-fingered ocarina may also feature thumbholes 102 which may include an enlarged thumbhole 102 b that is used to raise the pitch by three semitones, as opposed to the customary two semitones. The fingering pattern is altered accordingly.
By reference to FIG. 1B , a fingering chart, a clear understanding of the use of toneholes of an ocarina of the embodiment is rendered. On each representation of the ocarina 1 are representations of toneholes 100 . Stopped toneholes 100 are shown filled in black and unstopped toneholes 100 are shown unfilled. Representations of thumbholes 102 , 102 b are depicted adjacent to each representation of the ocarina 1 . Below each representation of the ocarina is printed the pitch 13 produced according to which toneholes 100 are stopped or unstopped if the tonic note is the note “C”. The tonic may actually be any note.
Referring to FIG. 2A , an ocarina 2 according an embodiment of the invention adds at least one, but preferably two, subholes 103 to an otherwise standard cross-fingering. The subholes 103 are not adjacent to the other toneholes 100 , but are arranged to be stopped by fingers other than those used to operate the other toneholes 100 , preferably the ring fingers. This allows for performance of all accidentals with greater ease than the prior art and as well as additional advantages. Since the subholes 103 are not adjacent to other toneholes 100 as they are in all prior art, they may more easily be utilized to perform trills, aid in performing crescendos, or change the key of a small passage. The subholes 103 are similar to subholes common in linear-fingered ocarinas of the prior art in that they may be used to expand the range of the instrument and lower the pitch below the tonic note. However, the subholes 103 are different from all prior art in that the fingers dedicated to the subholes are not needed to operate other toneholes and are thus unencumbered. FIG. 2B is a fingering chart depicting how the subholes 103 and other toneholes 100 of an ocarina 2 of the embodiment may be used to perform its range of pitches 13 . The tonic note may be any note, but in this example is the note “C”.
FIG. 3A depicts a two-chambered cross-fingered ocarina 3 according to an embodiment of the invention. It includes a body 10 , two airways 11 a and 11 b, and two voicings 12 a and 12 b, with the voicing 12 a on the underside for a lower chamber 14 a, meaning lower-pitched chamber, and the voicing 12 b on the top for a higher chamber 14 b, meaning higher-pitched chamber. The chambers 14 a and 14 b are both enclosed by the body 10 . A wall or partition 15 that separates the two chambers 14 a and 14 b is visible in cross-section in a broken portion of the ocarina 3 and is represented by hidden lines where the partition 15 lies hidden beneath the body 10 . In each chamber, the standard toneholes 100 of a cross-fingering are adjacent to the corresponding toneholes 100 of the other chamber. The two chambers 14 a and 14 b are used independently or simultaneously. The standard toneholes 100 can be used simultaneously to perform two corresponding notes at a one octave interval, or they may be fingered independently. Thumbholes 102 on the lower chamber 14 a are optional but desirable. These aforementioned features of the embodiment depicted in FIG. 3A are common in the prior art. Novel features according to the embodiment are the addition of at least one, but preferably two, subholes 103 to the lower chamber 14 a and two additional toneholes 104 to the higher chamber 14 b. The subholes 103 function in like manner to those described in the embodiment according to FIG. 2A , and overcome the limitation of the prior art to permit accurate performance of accidentals in the lower range or notes below the tonic. The additional toneholes 104 to the higher chamber 14 b function similarly to thumb-operated toneholes common in the prior art and overcome the limited range of one octave of the higher chamber of the prior art, such limitation being due to the impossibility of accessing the higher chamber with the thumbs. As an optional enhancement, the artisan may widen one of the additional toneholes 104 to increase the range by an additional semitone, in like manner to the enlarged thumbhole 102 b described according to FIG. 1A .
The artisan is required to form the shape of the higher chamber 14 b such that it can accommodate toneholes 100 , 104 that may easily accommodate the performer's fingers. Typically, the shape is like a widened one half of a peanut shell or a dome roughly in the shape of the number eight. The higher chamber 14 b may also include a split tonehole 101 as the second largest tonehole, like that described according to FIG. 1A , to allow the ocarina 3 to accurately perform all accidentals within the entire range.
Reference to FIG. 3B will make clear the fingering of the toneholes 100 of the lower chamber 14 a. Reference to FIG. 3C will make clear the fingering of the toneholes 100 of the higher chamber 14 b. The tonic of an ocarina according to the embodiment of the invention depicted here is “C”, but it may be any pitch.
Referring to FIG. 4A , a two-chambered linear-fingered ocarina 4 according to an embodiment of the invention is depicted. It includes two airways 11 a and 11 b, two voicings 12 a and 12 b, a lower chamber 14 a, a higher chamber 14 b, and a body 10 that encloses the chambers 14 a and 14 b. A wall or partition 15 separating the two chambers is also visible in cross-section in a broken portion of the ocarina 4 and is represented by hidden lines where the partition 15 is hidden beneath the body 10 . The toneholes 100 of the lower chamber 14 a are the same that are common in the prior art. However, the higher chamber 14 b and its accompanying toneholes 100 have novel functions that enhance the range of the chamber 14 b. A large thumbhole 105 is added to what would otherwise be a typical fingering pattern for a higher chamber of a two chambered ocarina. After the toneholes 100 of the top of the ocarina 4 are all unstopped, the performer unstops the large thumbhole 105 , and then uses the other toneholes 100 in a novel pattern to perform at least five additional semitones, these pitches all being above the highest pitch of a typical two-chambered ocarina.
A fingering pattern like the one according to the embodiment is not possible to add to ocarinas of the prior art. All linear-patterned two-chambered ocarinas of the prior art have higher chambers that are substantially tube-like in shape. Accordingly, not only is there insufficient space to accommodate a large thumbhole, but also a tonehole, whether for the thumb or another finger, large enough to expand the range would adversely affect the properties of the chamber to the extent that it would nullify the correct operation of the entire chamber, or, in other words, the notes would not play after the thumbhole is unstopped. Furthermore, a tube-like chamber is so lengthy that the fundamental pitch of the chamber must be well below the desired lowest-pitched note for the chamber. In compensation for this, and to compensate for weak volume or blowing strength of such chambers, a hole or holes are added to raise the pitch and let air escape. Since each chamber is limited in range, especially a higher chamber that requires greater blowing strength, a chamber whose fundamental pitch is many semitones below the desired lowest-pitched note cannot adequately perform above what is standard in the prior art.
The higher chamber 14 b according to the embodiment depicted is not tube-like. It preferably has a shape similar to a shelled brazil nut, with the widest portion thereof positioned toward the airway 11 b. The higher chamber's 14 b rounder shape has several advantages. The shortened length raises the fundamental pitch to the desired lowest pitch to be performed or near to it. Furthermore, the vessel-like shape typically results in a stronger, more sonorous sound. These two advantages may remove the need for additional tuning holes to allow air to escape for tuning or dynamic purposes. However, a small tuning hole or holes, not depicted, may be included if desired. A further advantage of the shape of the higher chamber 14 b is that it is sufficiently wide and tall that the presence of a large tonehole, for example, a large thumbhole 105 that raises the pitch by several tones, does not adversely affect the operation of the chamber 14 b and the other toneholes 100 . Accordingly, a higher chamber 14 b according to the embodiment in conjunction with an improved fingering enables the higher chamber 14 b to equal or exceed capabilities of both a second and third chamber of ocarinas of the prior art.
In order to achieve the improved shape of the higher chamber 14 b, the pinky finger tonehole 100 p typically must be angled toward the higher chamber 14 b from its outlet on the surface of the body 10 of the ocarina 4 . This method of angling the tonehole 100 p is depicted by hidden lines. Also, placing the pinky finger tonehole 100 p substantially near the side surface of the ocarina 4 as opposed to the top will allow the user to partially tuck the pinky finger under the ring finger in an ergonomic manner to cover the pinky finger tonehole 100 p. It is usually important to make a depression or indentation where the pinky is to be placed, both for comfort and so that the pinky finger tonehole 100 p may properly be sealed. The artisan should take into account the need to give the user's fingers sufficient space and to distance toneholes 100 from the voicing 12 as much as possible.
The fingering method for the lower chamber 14 a of the embodiment is common in the prior art and is therefore not depicted. The manner of performing the pitches of the higher chamber 14 b of the embodiment is depicted in FIG. 4B . The large thumbhole 105 is depicted adjacent to each representation of the chamber 14 b. The toneholes 100 are depicted within each representation of the chamber 14 b.
Referring to FIG. 5A , the two-chambered linear-patterned ocarina 5 depicted is identical to the ocarina depicted in FIG. 4A , with one exception. In FIG. 5A , an additional tonehole 106 has been added to the chamber to achieve a highest note two semitones above the highest note capable with the ocarina of FIG. 4A . FIG. 5B depicts the fingering pattern the performer would use to ascend the pitches 13 of the higher chamber 14 b of the embodiment to the highest possible pitch. With practice and skill the artisan, by using a large thumbhole in the higher chamber of a two-chambered linear-patterned ocarina, may possibly achieve a range even beyond that of the ocarina of FIG. 5A .
Referring to FIG. 6A , a three-chambered linear-patterned ocarina 6 according to the embodiment is depicted. The lowest chamber 14 a preferably has a layout and fingering pattern very similar to the lower chamber of a typical two-chambered ocarina with the exception that the notes to be performed are typically one octave below the normal range. The highest chamber 14 b of the embodiment is typically identical to the higher chamber of the ocarinas depicted in FIG. 4A or 5 A, here depicted identical to the higher chamber of the ocarina of FIG. 5A . The middle chamber 14 c of the embodiment preferably is pitched near the upper range of the lowest chamber 14 a of the embodiment, the middle chamber's 14 c lowest performable note being tuned to one semitone above the highest performable note of the lowest chamber 14 a. An optional tuning hole 107 helps balance the strength of air required by the performer to properly perform the lowest-pitched note, that the blowing strength required may be very similar to that required to properly perform the highest note of the lowest chamber 14 a. The performer utilizes a modified linear fingering pattern for the middle chamber, like that depicted in FIG. 6B , to perform the pitches of the chamber 14 c up to the highest. The highest performable pitch of the middle chamber 14 c is the lowest performable pitch of the highest chamber 14 b.
Constructing an ocarina 6 according to the embodiment enables the skilled artisan to provide an instrument capable of performing four octaves of notes, which is about one octave greater than three-chambered ocarinas of the prior art.
Referring to FIG. 7A , the three-chambered linear-patterned ocarina 7 depicted is identical to the ocarina depicted in FIG. 6A , with two exceptions: In FIG. 7A , one of the toneholes 100 on top of the instrument has been removed and has been replaced with a large thumbhole 105 on the bottom of the ocarina 7 and the tuning hole has been moved. Since a performer's thumb is able to seal a larger hole than the performer's other fingers, a large thumbhole 105 can be made large enough to allow the performance of additional pitches. Depending on the size of the large thumbhole 105 and the fingering pattern desired, the tuning hole 107 may also be incorporated into the fingering pattern. Providing additional notes in the middle chamber adds the benefit of allowing the performer to optionally perform some of the same notes on both the middle chamber and the higher chamber, which will reduce the need to switch between chambers. FIG. 7B depicts a fingering pattern of the middle chamber 14 c where the toneholes 100 , tuning hole 107 , and the large thumbhole 105 are used to perform pitches as labled. FIG. 7C depicts a fingering pattern of the middle chamber 14 c where only the toneholes 100 and large thumbhole 105 are used to perform pitches as labled.
While the above description contains many specificities, these should not be construed as limitations on the scope of the invention, but as exemplifications of the selected embodiments thereof. Many other ramifications and variations are possible within the teachings of the invention. Thus the scope of the invention should be determined by the appended claims and their legal equivalents, and not by the examples given. | Improved methods for tuning ocarinas to extend their capabilities, musical ranges, and ease of use. Ocarinas having enhanced fingering patterns using subholes, split toneholes, additional tonehole(s), and/or an additional thumbhole. Enhancements to cross-fingered ocarinas with one or two chambers and linear-fingered ocarinas with two or more chambers. | 6 |
RELATED APPLICATIONS
This is a continuation of, and claims the benefit of the filing date of, U.S. patent application Ser. No. 10/336,633, filed on Jan. 3, 2003, which issued as U.S. Pat. No. 6,849,826, and is a continuation of, and claims the benefit of the filing date of, U.S. patent application Ser. No. 09/956,405, filed Sep. 19, 2001, entitled Welding-Type Power Supply With Boot Loader, which issued on Jan. 7, 2003 as U.S. Pat. No. 6,504,131.
FIELD OF THE INVENTION
The present invention relates generally to the art of welding-type power supplies. More specifically, it relates to welding-type power supplies having a network, such as a controller area network (CAN).
BACKGROUND OF THE INVENTION
Welding power supplies or systems are available for a wide variety of processes, and with a wide variety of sophistication. Welding-type power supply or system, as used herein, includes power supplies or systems that provide welding, cutting or heating power, and may include a controller, switches, etc. Traditionally, a good weld required an experienced welder, not only to properly execute the weld, but to properly select operating parameters (such as output voltage, current, power, pulse width, wire feed speed, etc.)
Now, robots are available that execute the weld. Also, pre-determined welding programs that set operating parameters are available. These may be input to a welding-type system by a user using a user-interface such as a keypad, touch screen, control knobs, etc. Also, programs can be stored as application software and transferred to the welding-type system (where they are usually stored in non-volatile memory that is part of a controller). Application software, as used herein, includes software and data that controls a welding system before, during or after a weld, such as setting operating parameters, setpoints, etc.
It may be desirable to change application data because of improvements in the program, or improvements in the data, or because the welding-type system is used for a new or different application. Also, it may be desirable to change application software for multiple components of a welding-type system, such as the power supply, wire feeder, and robot interface.
The process of updating application software can be tedious—either entering the information through a serial interface board-by-board, or replacing a component such as an eprom (by removing the eprom and reprogramming it). Both of these procedures require removing the housing, which can be difficult.
Accordingly, a method and apparatus for updating software in a welding-type system that is easy, fast and economical. Additionally, the method and apparatus would preferably be useful over a network, so multiple components could be updated.
SUMMARY OF THE PRESENT INVENTION
According to a first aspect of the invention a welding-type power supply includes a source of welding-type power and at least one welding system peripheral. Each includes a network module that has boot loader software. A network is connected to the two network modules, and the network has connection for updates that is capable of receiving software updates.
In various embodiments the network connection for updating is on a user interface module, disposed in a housing with the source of welding-type power, disposed outside the housing, disposed on a pendant, on a network controller module, and/or includes an RS232 connection.
The network modules include application software in another alternative.
The peripheral is a wire feeder, a robot interface, or any other peripheral in various embodiments.
A second peripheral, such as a robot interface, is included, and has a network module, connected to the network, with boot loader software, in another embodiment.
According to a second aspect of the invention a method of providing welding-type power includes connecting a source of welding-type power to a network and controlling the connection by executing software that includes boot loader software. Also, at least one welding system peripheral is connected to the network, and the connection to the network is controlled by executing software that includes boot loader software. Software updates are received on the network through a network connection.
Application software that controls the source and the peripheral is also executed in other embodiments.
According to a third aspect of the invention a method of updating software used to control a welding-type system includes executing boot loader software and determining if a software update over a network is available. The boot loader software continues and a software update is executed if a software update is available, and then the execution of the boot loader software is ended after the software update has been completed. If no software update is available, then the boot loader software completes it program and is terminated.
The method is performed when the system is powered up in one embodiment.
The software update is an application software update in another embodiment.
In other embodiments, before ending the execution of the boot loader software, an error check and/or keyword check is performed, and/or application software is executed after the boot loader finishes.
The software update is obtained from a personal computer, a personal digital assistant, or over the internet in various embodiments.
According to yet another aspect of the invention, a software subroutine (a subset of software capable of controlling a welding-type power supply and a welding system peripheral) is capable of transmission through a network connection to overwrite at least a portion of the software which controls the welding-type power supply and the welding system peripheral upon prompting.
Other principal features and advantages of the invention will become apparent to those skilled in the art upon review of the following drawings, the detailed description and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram of a welding-type system in accordance with the present invention;
FIG. 2 is flow chart of a CAN boot loader routine; and
FIG. 3 is flow chart of a routine to transfer software to a CAN.
Before explaining at least one embodiment of the invention in detail it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting. Like reference numerals are used to indicate like components.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
While the present invention will be illustrated with reference to a particular welding system and particular components, it should be understood at the outset that other welding-type system, peripherals and components could be used, and the invention could be used in other applications. Welding system peripheral, as used herein, includes wire feeders, robot interfaces, gas supplies, user interface, or other devices that work with a welding-type system.
Generally, the invention includes a controller area network (CAN), or other network, with a plurality of components in a welding-type system attached thereto. The network allows for communication between and control of (instructions, feedback, etc.) components in a welding-type system. Each component or module includes a controller and software that controls that module. Each component also includes a network module, for connecting to and communicating through, the network. Network module, as used herein, includes a module, hardware and/or software, that effects connection to and/or communication via a network, and/or includes control software for a component or module.
Each network module (or component controller) also includes application software that controls the component, such as a motor control commands, switch inputs, etc., for a wire feeder, and display language, the information being displayed, etc., for a user interface module. Along with the application software, the network module has boot loader software that runs when the system or component boots up. Boot loader software, as used herein, includes software that loads during the booting of a software controlled system, network or module.
The invention generally provides that, at power up, the boot loader software for each component checks to see if a software update for that component is present on the network. If it isn't, the boot loader software continues to execute, including performing error check such as CRC, and key word checks. If the checks pass, control is handed off to the application software for that module or component.
If a software update is present on the network, the boot loader software updates the application software. After the software is updated, the boot loader continues to error check, key word check, and then hands off to the application software. Software updates, as used herein, includes changes to, replacements for, or additions to, software used in a welding-type system.
Thus, the boot loader software is executed at power up, the software update is executed if needed, and the application software is executed to operate the system. Executing software, as used herein, includes carrying out a program or series of instructions.
More specifically, a welding system 100 , with an update network connection, includes a power control module 102 or source of welding-type power, a wire feeder module 104 , a robot interface module 106 , a user interface module 108 and a connection 110 .
Source of welding-type power, as used herein, is the power and associated circuitry that can produce welding-type power when power is applied thereto. Update network connection, as used herein, includes a network connection on which updates may be received. It may be an internal or external network connection. External network connection, as used herein, includes a connection from a network to a device that is not previously on the network, or is not continuously on the network. Internal network connection, as used herein, includes a connection from a network to a device that is continuously or routinely on the network.
The invention may be used with a wide variety of types of power modules or types of robot interfaces. Examples of a particularly suitable power module is found in the Miller Alt304® or Miller MaxStar® welding systems, and described in U.S. patent application Ser. No. 09/540,567, filed Mar. 31, 2000, entitled Method And Apparatus For Receiving A Universal Input Voltage In A Welding, Plasma Or Heating Power Source. Another power module is described in U.S. Pat. No. 6,115,273, entitled Power Converter With Low Loss Switching, issued Sep. 5, 2000, which is hereby incorporated by reference.
Preferably, each component or module includes its own network module, such as DeviceNet hardware and software. The network connections between modules are preferably DeviceNet compatible.
The network is connected through connector 110 to a network controller module or a CAN 112 . Network controller module, as used herein, includes a module that controls all or part of a network, including a CAN. A converter 114 converts the CAN (or DeviceNet) connection to an RS232 connection. An RS232 connection is made to a PC 116 , which has the software update.
When welding-type system 100 is powered up, the software in each network module boots up. It checks the network for software updates, and if an update is present on PC 116 , the boot loader software updates the application software for that module. Each module may simultaneously begin the boot process, and the network protocol determines data flow on the network so that each module is updated as necessary.
Alternative connections may be made, and include as using IR or other wireless, connecting converter 114 to the internet (using perhaps an EtherNet connection), and/or using a modem. Other alternatives (which are shown with dashed connections) include connecting directly from user interface module 108 (which may be a front panel display) to PC 116 . User interface module, as used herein, includes a module, software or hardware, that allows communication between a welding-type system and the user, either directly or through a network.
Another alternative includes using a pendant 118 as the user interface. Pendant, as used herein, includes a device external to a welding-type system that may be connected to or communicate with the system. In this alternative, pendant 118 is connected to PC 116 . Yet another alternative is to provide a PDA as pendant 118 , and the software could be provided by the PDA. The various alternatives are not intended to be exhaustive, and may be used alone or in combination.
FIGS. 2 and 3 are flow charts showing the CAN boot loader software and the RS232 to CAN software. Other software may be readily used, and the flow charts are meant to be exemplary.
Referring now to FIG. 2 , CAN boot loader software representative of that found in any of the modules, begins with power up at 201 . The system initializes at 202 and checks for a CAN connection message at 203 . The check is performed four times, at 500 ms intervals.
At 205 it is determined if a valid CAN connection message was received. If a valid CAN connection message wasn't received, then the CAN bootloader ends, and the RS232 boot loader software begins.
If a valid CAN connection message was received the program delays one second and then flushes any remaining incoming CAN messages at 207 , and waits for a new CAN message at 209 .
At 211 it is determined if the message received is a CAN connection message. If it is, the program checks if this module has been flagged as selected for updating at 212 . If the module isn't to be updated, the routine returns to 209 . If the module is to be updated, a CAN response message is sent to the controller at 213 , and the routine returns to 209 .
If, at 211 , the message was not a CAN connection message, then at 215 it is determined if the message is a start update message for this module. If it is not, the program returns to 209 .
If the message was a start update message for this module then, at 216 , the flash is erased. Also, at 216 , it is determined of the erasure was error free. If it was not error free, an error CAN message is sent to the controller at 217 and the program returns to 209 (and waits to start the file transfer over).
If the erasure was error free at 216 , then at 220 one line of the hex file (the update) is received through CAN messages. It is determined if the hex file is done being sent at 221 . If the hex file is not done it is determined if there was an error during the hex file line transfer at 222 . If there is an error the routine returns an error message at 217 and then waits, at 209 , to start the file transfer over.
If there was not an error during the line transfer the hex line is written to flash memory at 223 . The writing is checked for errors at 224 . If there was an error writing the line to flash the routine returns an error message at 217 , and then waits, at 209 , to start the file transfer over. If the line was properly written to flash the routine returns to 220 to get another line of the file.
If, at 221 , it is determined that the file is completely transferred, then at 226 the CRC value (an error check value) is calculated and stored in flash. At 227 the CRC value is checked to see if it is OK (indicating error free transfer). If it is not OK the routine returns an error message at 217 and then waits, at 209 , to start the file transfer over. If the CRC value is OK, the CRC value is sent at 228 (instead of the error message) in the next block, and the routine returns to 209 .
Referring now to FIG. 3 , a flow chart showing an example of the RS232 to CAN software begins with power up at 301 . The system initializes at 302 and at 303 the software sends a connection message. It is sent six times at 500 ms intervals. The message is intended for five modules (one, two, three, four, or any number of modules could be present). The software causes a display sign-on message to be seen on PC 116 and requests the user to input checksums for the modules at 304 . The checksums are for verification.
Next it waits for the user input through PC 116 at 306 . If a “U”, indicating update is received at 303 , it allows, through user input commands, the user to select which modules need updating. Preferably yes or no user prompts such as “Update PCM flash? (Y/N), Update UIM flash? (Y/N) Update WFCM flash? (Y/N) Update RIO flash? (Y/N)” are provided to the PC. Then the software issues another connection message intended for the modules that require updating. A message is sent to the user to indicate whether all the modules to be updated responded at 308 , and then the program returns to 306 .
At 310 it checks to see if the user inputs a ‘P’, for the program command. If a P is entered, it checks at 311 if there are modules to update at 311 . If there aren't modules to update the program returns to 306 .
If there are modules to update, at 313 an “erasing flash” message is displayed (for next module that needs updating), and a CAN message is sent to the appropriate module that starts erasing the flash memory in that module at 314 . The program waits 3 seconds for the erasing to be completed, and then prompts the user to send the proper hex file from the PC (which was to replace the old application software) at 315 .
The hex file is sent line by line to the appropriate module at 316 . Each line includes a CRC value for error checking. After the file is sent, a terminate message is sent to the module being updated, and after a 4.5 second delay, it receives a message from the module at 317 .
At 318 the program determines if the message is a checksum message, and does it agree with the value entered on startup. If it is and does, then it displays an appropriate message to the user. If the message is an error message, it displays an appropriate error message to the user. Then, the program returns to 311 .
These routines may be implemented using different commands, or other routines, and other hardware, may be used to implement the CAN boot loader.
Numerous modifications may be made to the present invention which still fall within the intended scope hereof. Thus, it should be apparent that there has been provided in accordance with the present invention a method and apparatus for a welding-type system with software updates that fully satisfies the objectives and advantages set forth above. Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. | A method and apparatus for providing welding-type power are disclosed. They include a source of welding-type power and at least one welding system peripheral. Each includes a network module that has boot loader software. A network is connected to the two network modules, and the network has connection for updates that is capable of receiving software updates. The network connection for updating may be on a user interface module, disposed inside or outside of a housing of the source of welding-type power and may include an RS232 connection. The network modules may include application software. The peripheral may be a wire feeder, a robot interface, or any other peripheral. A second peripheral, with a network module and boot loader software, may also be connected to the network. The updating can occur when the system is powered up. The software update is obtained from a personal computer, a personal digital assistant, or over the internet. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of prior application Ser. No. 09/920,874, filed on Aug. 2, 2001 now U.S. Pat. No. 6,484,165, which is a continuation of prior application Ser. No. 09/514,524 filed on Feb. 28, 2000 now U.S. Pat. No. 6,321,224, which is a continuation of prior application Ser. No. 09/058,553 filed on Apr. 10, 1998 and issued Feb. 29, 2000 as U.S. Pat. No. 6,032,145.
FIELD OF THE INVENTION
The present invention relates to software for database interrogation and manipulation and, more particularly, to a method and system for retrieving database records using predefined classifications, and further coupled with search refinement options based on parametrics and classification.
BACKGROUND OF THE INVENTION
Searchable electronic catalogs are commonly used in support of various electronic commerce and purchasing functions. These catalogs must have a user interface for selectively retrieving data records. Software engineers desire to make the user interfaces as simple as possible to operate, because complexity of the user interface can be a detriment to sales from the catalog. Simplicity becomes particularly important when the catalog is intended to be accessed by users with varying levels of skill or training.
User interfaces that are simple to operate should have the capability to handle almost any type of user input. In the case of an electronic catalog, if the user knows the exact part number of the desired product and enters the part number correctly into the user interface, then the database search engine will quickly identify the desired record from the database based on an exact match with the search string. In a more general case, the user may have only partial information about the desired product, or may incorrectly type the search string.
Danish et al. in U.S. Pat. No. 5,715,444 disclose a process for identifying a single item from a family of items in a database. A feature screen and search process present the user with a guided nonhierarchical parametric search to identify matching items based upon user specified criteria and priorities. Also disclosed are a method and system appropriate in an Internet environment.
Cochran et al. in U.S. Pat. Nos. 4,879,648 and 5,206,949 disclose a method of variably displaying search terms in which two control inputs are used to select a plurality of terms for a plurality of categories. A term in a visible position on the screen becomes a search term or a qualifier for other records in the database. The search results are dynamically formed on the basis of selected search terms. The search results can also be grouped in fixed or static lists.
Blutinger et al. in U.S. Pat. No. 5,231,566 disclose a method and apparatus for producing a catalog. The catalog has the characteristic that all like items in the database have the same catalog item number, whereas different items have different catalog item numbers.
Geier et al. in U.S. Pat. No. 4,984,155 disclose a system for enabling a customer to operate a data terminal for placing an order for goods or services. The customer is permitted to enter an invalid catalog number that is used as a key to display a series of products having catalog numbers similar to the catalog number entered by the customer.
Prior catalog search algorithms typically employ one of two search strategies. The first strategy is a keyword search for selecting database records based on matching text strings. The second strategy is a hierarchical search for selecting database records based on lists of classifications from which to narrow and select the database records. Each of the two search strategies has disadvantages that can make it difficult for users to find their desired database records.
The keyword search strategy has the disadvantage that users must be familiar with the appropriate key word terms that are likely to yield the desired data records. In addition, it is not always possible to quickly collect groups of logically related data records. If a close match is found, but it is not the desired exact match, it is not always possible to utilize the information in the close match to quickly identify all similar data records. A keyword search engine does not typically have a “more-like-this” function that operates on close matches to identify similar items within the database.
The hierarchical search strategy can take advantage of a logical grouping of data records. This search strategy is best suited for finding data that break down logically into successively greater levels of detail. This search strategy is most effective when the data have been carefully edited and structured within a database. Finding a single relevant record can quickly lead to all other relevant records, as long as the grouping logic relates to the way in which the data are used.
Thus, a “more-like-this” function can quickly identify all similarly classified records in the database.
The disadvantage of the hierarchical search strategy is that users may not always anticipate the proper classification of certain records, and may search the wrong categories for their desired database record. The user is tied to the logical structure of the data, and must learn to navigate the predefined structure of the database in order to locate particular data records.
It would be desirable to allow free-form text searching, with no prerequisites for format or content. Thus, it would be desirable to have a system capable of identifying the database records most likely to be the desired choice of the user, even when the user inputs a search string having misspelled terms, word fragments, or other characteristics of the item being sought. It would further be desirable to take advantage of natural relationships and logical groupings within the data records to compile lists of similarly classified data records. The prior art has not disclosed a system that provides a simple and convenient user interface coupled with a search engine that has the architecture and advantages of the present invention.
SUMMARY OF THE INVENTION
The present invention provides a simple user interface that combines the ease of keyword searching with the advantages of search refinement through classification or parametric selections. The text searching is improved through the use of sequential search algorithms that are designed to maximize the chances of identifying the desired data records. The search refinement is presented as a simple selection from a list of classifications that is dynamically compiled based on the results of the keyword search. The output to the user reports on both generic and category-specific product characteristics.
According to the present invention, a method of selecting data records in a catalog database comprises the following steps: inputting search terms to a user interface; testing the search terms against the catalog using a sequence of search algorithms, wherein each search algorithm is applied against the database to identify matching catalog records comprising a set; terminating the sequence of search algorithms when at least one record becomes a member of the set; compiling a unique list of classifications from each member of the set, said list comprising at least a first classification; displaying at least a portion of the set along with the list of classifications; creating a subset of the set by selecting members having the first classification; and displaying the subset.
The invention comprises a database along with a search engine. The database typically consists of category descriptions, manufacturer's name, manufacturer part number, short text description, and parametrically composed descriptions. Product categories and characteristics are represented directly by tables and columns respectively.
The search engine executes a series of text string matching algorithms, in sequence, until at least one match is identified from the catalog. The sequence comprises proximity searching, string matching, stemming, fuzz logic, and soundex matching. For example, if an exact match is found, the search halts when all exact matches have been identified, and there is no further recourse to other search algorithms. If no exact match is found, then the search terms are manipulated to identify strings with similar roots. If, again, no match is found, the search terms are tested further according to other algorithms, such as fuzzy logic and soundex, until a match is found or the search engine reaches its logical termination.
One of the important aspects of the search strategy is that the searchable terms include the predefined classification terms as well other attributes and parameters of each catalog entry. This means that the freeform text input will show text string matches against any classification name or parametric name. This feature enhances the possibility of finding the desired data record based on the keyword search engine.
Each catalog entry has an associated classification according to type, and a list of unified classifications is compiled dynamically from the identified matches. Dynamic compilation refers to the process of continuously updating the list of classifications whenever new matches are identified. This insures that the list continuously and accurately reflects the range of classifications of the identified matches. The list is unified in the sense that each classification is listed only once, even when the identified matches have multiple records with the same classification. The classification list is presented to the user along with the list of matches as an aid to the user for further refining the search methodology.
Those skilled in the art will recognize the benefits and objects of this invention, which include but are not limited to the following: providing a database search engine that can quickly and easily lead users to a desired database record; combining the benefits of key word searching with the benefits of hierarchical searching; providing an interface that will process any type of user entry, including misspelled words and word fragments; displaying a list of product categories that can be used to narrow the database search criteria; providing a search engine and database structure that maximizes the likelihood of finding the desired database records based on a simple user interface.
BRIEF DESCRIPTION OF THE DRAWINGS
The subject matter which is regarded as the invention, together with further objects and advantages thereof, may best be understood by reference to the description herein, taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a block diagram representation of an electronic catalog requisition system employing the present invention.
FIG. 2 a is a logic diagram of a search engine according to the present invention.
FIG. 2 b is a display and refinement of search query results.
FIG. 3 is a representative display of the results of a search at the user interface.
FIG. 4 is a representative display of the results shown in FIG. 3, and further narrowed by, selection of a single classification from the user interface.
FIG. 5 is another block diagram representation of an electronic catalog requisition system employing the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a functional block diagram representation of an electronic catalog and automated purchase requisition system. An application server 12 is connected to interact with a database 14 which resides in a computer memory storage device 16 . Users of the system have workstations 18 that are connected to the application server 12 through a wide area network such as the Internet. Commands entered into web browser software cause information to be extracted from the database 14 and displayed at the workstation 18 .
The database 14 is an electronic catalog of products. The database 14 is preferably constructed in a manner known as a “universal” catalog, in which like products from different suppliers have a single database record. Constructing a universal catalog typically requires an editor to ensure that each unique product has a unique database record. This database architecture has the advantage that users will be able to recognize identical products from different suppliers. In contrast to a universal catalog, an aggregated catalog is merely an aggregate of product information from multiple suppliers. The same item may be listed several times in an aggregated catalog, though not usually in a consistent manner, with the undesirable result that users may not recognize that different database records actually refer to the same product.
In one embodiment of the invention, the software 10 is configured to access one of several electronic catalogs. The selection of a catalog is based on the likelihood that the catalog will have the desired item. As such, there must be a standard query format for each of the catalogs so that the same search string can be used to determine possible matches against each catalog. The match results can then be used by the software 10 to select among the catalogs. The type or format of the catalog is irrelevant as long as the catalog will respond appropriately to a text query from the software 10 . For example, the catalog may reside within a relational database or may reside within an object-oriented database.
Referring back to FIG. 1, the storage device 16 may be a disk drive, a tape drive RAM, or any of the known computer data storage devices. The application server 12 may reside in a computer attached directly to the storage device 16 , or alternatively may be connected to the storage device 16 through a network. In each case, the application server 12 queries the database 14 and directs the results to the workstation 18 .
Software 10 is executed within the application server 12 . The software 10 follows an algorithm as shown in the logic block diagram of FIG. 2 . The user inputs a search string, as shown in block 100 . The search string is free form, meaning that the string may be any combination of alphanumeric characters or search terms. No particular syntax is required for the search string. The search string may comprise search terms in any order. For example, the search string could include the name of an item, a part number for an item, or any descriptive attribute of the item.
The software 10 is designed to handle misspellings, word fragments, or any other string that may lead a user to find the desired product within the database 14 .
The software 10 preferably has a single text box for search strings, shown as box 300 of FIG. 3 . The example search string in box 300 is “bic pen red” which represents a combination of manufacturer name, classification, and attribute. It has been found that users desire the simplicity of typing strings at a single location, without differentiating whether the string represents a product name, a product manufacturer, or a product attribute. Alternatively, there may be separate text boxes for different types of search strings.
The software 10 performs a proximity query which will try to find an exact match of the search string within the database 14 . Each record within the database is tested against the search string to find records that contain all of the search terms in proximity to each other. The highest quality match will be a record in which all terms appear in the same order as the search string. A lower quality match will have the terms in a different order, or may have the terms separated by other strings. The proximity query is a well-known procedure in the art of computer science, and certain commercial databases offer a proximity query function. An example of a database software package having the aforementioned function is Oracle 8 and the associated context cartridge, supplied by Oracle Corporation of El Segundo, Calif.
At the conclusion of the proximity query, the software 10 checks to see if any matches were found, as shown in block 102 . An exact match will lead the software to test whether price and vendor information need to be provided to the user, as shown in block 112 . If no exact. match is found, the software 10 sequences to the next type of search strategy.
Block 104 in FIG. 2 a shows the preferred second sequential search algorithm. Since no exact match has been found, the software performs a word count query in which individual words or search terms within the search string are checked against the products in the database 14 . The strategy at this point to find products within the database 14 that may match some of the descriptive terms in the search string. The word count query may also apply a stemming function to search terms to identify similar root words.
Block 106 test the results of the word count query to determine if any matches have been identified. If at least one item from the database 14 has been returned by the search algorithm, the software 10 proceeds to block 112 . Otherwise, the software 10 executes the next algorithm in the sequence of search algorithms.
As shown in block 108 , the next search algorithm in the sequence is preferably a fuzzy logic query. In this context, a fuzz logic algorithm may also be known in the art as a “word wheel” or other name associated with an algorithm for testing combinations and permutations of the alphanumeric characters in the search string. The intent in block 108 is to identify products in the database 14 having any descriptive similarity to the search string. For example, a user who enters a search string having a typographical error will not generally find an exact match within the database 14 , but a fuzzy logic algorithm may select the desired product on the basis of similarity with the search string.
The software 10 may also rank the degree of similarity between each matched database record with the search string. For example, records with a larger number of alphanumeric character matches against the search term will be ranked higher than records with only a few matching characters. Ranking algorithms are found in several commercially available software packages including Oracle 8 .
There are other possible sequences of search algorithms, but in general it is desirable to execute the narrowest, or most specific, search first. The sequence should proceed with search algorithms according to the scope of each algorithm. For example, a search for the specific search string is the narrowest in scope, whereas a search for related search strings will be broader in scope because it will likely return a wider range of matches.
An additional type of search algorithm not specifically shown in FIG. 2 a is a “soundex” or “sounds-like” search, in which the search string is tested against database records for similarity in sound.
If any match is found as a result of a search algorithm, the successive search algorithms will be skipped and the software 10 will proceed to display the results. If the software 10 has been configured to add price and vendor information, that will also be added to the display as shown in block 116 . In the unlikely event that no matches were found after completion of the entire sequence of search algorithms, the software 10 will proceed to the display block 114 with a message indicating that no products were found.
The display will have several areas of information, as shown in FIG. 3 . The search string is shown in a text box 300 , preferably located in the upper-left corner of the display. The list of matching items is shown in a display list 302 . The display list 3702 includes the category, the manufacturer name, the manufacturer part number, and descriptive attributes.
A compilation of each unique category of product, compiled from the list of the matching items, is shown in a category display area 304 . If several different categories of products were found during the search, then each category will be displayed along with a corresponding radio button 306 .
Returning to the logic of the software 10 , FIG. 3 is representative of the logic contained in block 118 of FIG. 2 b . If the desired item from the catalog is not immediately visible in the display, the user has the option of paging through the remaining items in the list by clicking on button 308 in FIG. 3, which is shown as logic block 120 in FIG. 2 b . If the desired item is found, no further searching is required, and the logic of the algorithm drops to block 134 .
As an alternative to paging though a lengthy list of products, the user can narrow the list by selecting one of the categories. For example, FIG. 3 shows that two different categories of items were found: pens and pea refills. Since there are 29 matching items (only the first 10 are shown), the selection of radio button 306 will narrow the list to include only pens and not pen refills. A new display will be generated, shown in FIG. 4, wherein the updated display list 402 has 27 items which do not include pen refills. In this embodiment, selecting a category will be restrictive in terms of the items in the display list 302 . This procedure is shown as logic block 124 in FIG. 2 b.
In an alternative embodiment of the invention, selecting a category will generate a new display list 302 containing every item in the catalog associated with the selected category. In this alternative embodiment, selecting a display list may be expansive in terms of the number of items shown on the display list 302 .
A further alternative is to select only items having a particular manufacturer. For example, FIG. 3 has a button 310 which invokes a screen containing a list of all manufacturers of the products shown in the display list 302 . Selecting one of the manufacturers will cause the software 10 to narrow. the display list 302 to include only items from the selected manufacturer.
In general, items within the catalog will have parameters that can be selected to restrict the display list 302 . For example, a parameter for pens may be “ink color” and has values of blue, black, or red. In the event that pens are selected as a category, the display list 302 may be further restricted to pens of a single color. This process is referred to herein as parametric refinement.
In the preferred embodiment of the invention, the algorithm will have a list of synonyms for each attribute. The search algorithms can replace individual search terms with appropriate synonyms for purposes of matching data records. The attributes are normally used as part of an algorithm for finding matches, and the use of synonyms for the attributes gives additional flexibility to the range of search strings that will produce meaningful matches.
Another way to increase the flexibility of the search algorithms is to allow natural adjectives in the search string to help select certain attributes. For example, if there is a category for computers, and the category has an attribute for processor speed, then the adjective “fastest” in the search string could be used to select the fastest computer. Slower computers would be eliminated from the display list 302 .
Yet another way to increase the flexibility of the search algorithms is to assign categories alternative roles such as, but not limited to, problem spaces and applications. In this embodiment, the items found by the query are actually predefined queries that generate lists of actual data records from the database. Thus, selecting a category becomes equivalent to submitting a predefined query to the database.
If the search did not reveal the desired products from the database 14 within the list, the user is prompted to try a new search string, as shown in block 128 of FIG. 2 b . Alternatively, the user may select an item, and a predefined query within the database record for that item will be input to the software 10 as a new search string, resulting in a new and updated list of categories being displayed to the user.
FIG. 5 is an alternative simplified diagram that explains the logic of the software 10 . Block 501 is representative of web-browser software that executes on a user's local computer. The text box, such as shown as 300 in FIG. 3, is presented to the user. The user enters the text description, as shown logically by block 502 . The sequence of search algorithms is performed on the text description, as shown logically by block 503 . The user picks an item for a display list, such as the list shown as 302 in FIG. 3 . The user further refines the search with one of several options as shown in logical block 504 in FIG. 5 . The user may enter more text, less text, or better (more descriptive) text and thereby generate a new display list 302 . Alternatively, the user may select a category, and further may select a parametric value (also called an attribute). Once a desired item is identified, the user is presented with supplier and pricing information, as shown in logical block 505 .
The electronic requisition system can provide links to further information about items within the database. The further information can be stored within the database 14 , or alternatively may be stored at a remote computer accessible through the Internet. For example, buttons on the display screen can invoke links to web sites that contain relevant information.
Items within the catalog are preferably cross-referenced so that related items can be quickly located. For example, if the user selects a printer from the catalog, the appropriate toner cartridge can be immediately located by pressing a button on the display list.
Once a user identifies the desired product from the database 14 , the software 10 can generate a purchase requisition having preformatted price, vendor, and user information. Individual contract terms and pricing information can be accessed by the software 10 to be reflected in the requisition. The requisition can be sent electronically to the vendor for processing.
It will be apparent to those of skill in the appertaining arts that various modifications can be made within the scope of the above invention. Accordingly, this invention is not to be considered limited to the specific examples chosen for purposes of disclosure, but rather to cover all changes and modifications which do not constitute departures from the permissible scope of the present invention. Having thus described our invention, what is desired to be secured and covered by Letters Patent is presented in the appended claims. | A method and apparatus are described to perform cascading search methodologies records in a database. In one embodiment, the method comprises receiving a free-form search string, comprising one or more search terms, from a user, searching a database to identify records in the database containing the search string, if no data records are identified, searching the database by applying an ordered sequence of search algorithms to identify data records containing strings similar to the search string, and to display the identified records. | 8 |
FIELD OF THE INVENTION
[0001] The present invention relates to sealing conduits, and in particular to an expanding conduit sealer.
BACKGROUND OF THE INVENTION
[0002] Electrical conduit is used to mechanically protect electrical conductors. The U.S. National Electrical Code and Canadian Electrical Code require that explosion-proof enclosures housing arcing and sparking devices be sealed off to prevent propagation of flames or gases through the conduit system, and to minimize the explosion pressures. Such seals minimize the effects of pressure piling by acting as a barrier to stop burning gases from traveling through the conduit to other parts of the system.
[0003] When sealing conduit fittings, past methods utilize a fiber material that is weaved around each electrical conductor in the conduit to separate them. The fiber material is also packed in to form a dam at each end of a horizontal fitting, and at the bottom of a vertical fitting. A Portland type cement is then mixed with water and poured in through a funnel, puddled with a stick to remove air bubbles and left to cure for at least 24 hours.
[0004] The past methods were fairly labor intensive and error prone. Errors resulted when electrical conductors were not separated or fittings were not filled completely full with sealing compound. Further labor included obtaining clean water and mixing containers and the use of a stick to remove air bubbles.
SUMMARY OF THE INVENTION
[0005] An expanding compound is used to seal conduit fittings. The compound is injected into the fitting, and expands to separate conductors within the fitting. In one embodiment, the compound expands to four times its size, and hardens within approximately one hour. In a further embodiment, the compound is a two-part product that is mixed in a self contained applicator and injected into the fitting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] [0006]FIG. 1 is a cross section of a horizontal mount sealing fitting illustrating use of a sealing compound.
[0007] [0007]FIG. 2 is a cross section of the sealing fitting of FIG. 1 with expanded sealing compound.
[0008] [0008]FIG. 3 is a cross section of a vertical mount sealing fitting illustrating use of a sealing compound
[0009] [0009]FIG. 4 is a cross section of the sealing fitting of FIG. 2 with expanded sealing compound.
DETAILED DESCRIPTION OF THE INVENTION
[0010] In the following description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural, logical and electrical changes may be made without departing from the scope of the present invention. The following description is, therefore, not to be taken in a limited sense, and the scope of the present invention is defined by the appended claims.
[0011] [0011]FIG. 1 shows a horizontal fitting 110 for joining two horizontally disposed conduits via mating sets of threads 115 and 120 at each end of fitting 110 . The length of the fitting is approximately the distance between the two sets of thread, and the width of the fitting is approximately equal to the outside diameter of the fitting.
[0012] Multiple conductors 123 are disposed within the fitting. Two openings 125 and 130 are provided in the fitting 110 . Removable plugs are used to plug the openings. Opening 125 is shown without the plug installed, and a plug 135 is shown installed in opening 130 . Opening 130 is larger than opening 125 in one embodiment. An expanding sealing compound 133 is provided in a liquid state inside the fitting 110 . One of the plugs may be removed to allow injection of the sealing compound. In this example embodiment, the sealing compound is injected through opening 125 .
[0013] In one embodiment, the sealing compound 133 is a two-part mixture that starts to expand once the two parts are mixed. When expanded, it fills the fitting 110 as shown at 210 in FIG. 2. The expanding compound works its way between conductors so that as it expands, the conductors are separated from each other. In one embodiment, the expanding compound expands four times its size immediately after being mixed. It is desired that when the compound is expanded, none of the conductors are touching either themselves, or sides of the fitting 110 , and the compound expands to fill the fitting 110 over at least a portion of the length of the fitting 110 referred to as a sealing chamber 137 which extends between the two ends of the fitting 110 . In one embodiment, the sealing chamber 137 extends approximately about and partly past the hub stops 140 and 145 on each end of the fitting. In a further embodiment, the sealing compound forms an explosion proof seal.
[0014] In one embodiment, the expanding compound is provided in a cartridge with the two parts or materials separated by a barrier, such as a foil barrier partway between a top and bottom of the cartridge. The cartridge is squeezed to deform the foil barrier, and a mixing rod is coupled to a plunger in the cartridge. The plunger is then pushed to the bottom of the cartridge by the rod. The rod is then pushed and pulled between the top and bottom of the cartridge for approximately 40 to 50 strokes, where a stroke is one complete in and out cycle. The cartridge is rotated while the rod is pushed and pulled to ensure that the plunger is swiping all material in the cartridge.
[0015] In one embodiment, mixing is done within 30 seconds of starting the mixing process, as pressure builds up on the inside of the cartridge as the material starts to expand. At the last stroke, the mixing rod is pushed all the way to the bottom of the cartridge. The rod is then pulled out, while the cartridge is squeezed to hold the plunger at the bottom. A nozzle is then attached to the top of the cartridge where the rod was removed, and then the rod is used at the bottom of the cartridge to push the plunger. This causes mixed liquid material, the expanding compound, to be injected through the nozzle. In one embodiment, the cartridge is marked with volumetric increments corresponding to one-ounce segments for measuring the amount of compound injected. The sealing fitting plug is promptly replaced and tightened to prevent the sealing compound from expanding outside the fitting and/or gelling around the threads in the fitting that mate with corresponding threads on the plugs.
[0016] The term “compound” in one embodiment comprises the use of two or more materials that are mixed and start expanding. In further embodiments, the compound is a single material that may start expanding at a controlled time, such as by exposure to air or other gases or by electrical stimulation, heat, or any other controllable event.
[0017] Typical applications are for sealing fittings in the ½ inch to 6 inch trade sizes. The temperature of the compound should be between 4° C. and 29° C. The compound in one embodiment will expand approximately 4 times its size following injection. The amount of compound for different size fittings may be established empirically, but is approximately one fourth of the volume of the sealing chamber. Some hazardous areas that the seals may be used in include, but are not limited to Class I, Division 1 & 2 Groups A, B, C, D and Class I, Zones 0, 1 & 2.
[0018] In one embodiment, the compound used is Chem-Cast 637 sealing foam c/o Chem-Cast 637 isocyanate and Chem Cast 637 Polyol. Isocyanate is a dark brown liquid, insoluble in water with a boiling point of 392 degrees F (200 degrees C.), a vapor density of 0.00016 (mm Hg) and a specific gravity of 1.2 g/ml. Polyol is a gray liquid, partially soluble in water with a specific gravity of 1.05 g/ml. When mixed together the resultant material is gray in color. It has a rise time of 1.5-2.5 minutes and a gel time of 4-5 minutes. When fully cured the foam density is 15-20 lbs./ft 3 The compression strength is >60 psi, porosity is >90% closed cell and has a water absorption of <1%. Chem-cast 637 is a fire resistant two-part rigid, polyurethane foam. It expands to fill voids inside of the sealing fitting and forms a dense, high strength foam. It has excellent adhesion to many surfaces without the use of primers.
[0019] [0019]FIG. 3 shows a vertical fitting 310 for connecting two vertically disposed conduits via threads 315 and 320 . Multiple conductors 323 are disposed within the fitting. One or more openings 325 and 327 provide access to the inside of the fitting. Threaded plugs are used to plug the openings. One plug 328 is shown installed in opening 327 , which is a lower opening. In one embodiment, opening 325 is a top opening that provides access to the inside of the fitting 315 to inject the liquid compound. Opening 327 provides access to create a fiber dam 330 at a bottom of the fitting, referred to as a hub. In one embodiment, the fiber is a mineral fiber, such as Chico X® sealing compound provided by Crouse-Hinds and it is packed using a hardwood stick of other tool that will not damage the conductors. Hub sizes range from ½ inch to 6 inches.
[0020] The fiber is first packed while the conductors are forced away from the hub opening and forced apart. The fiber is then packed between and around conductors in the hub to form the dam 330 . An area above the dam 330 is referred to as a sealing chamber 340 . The dam provides a means of blocking the un-gelled expanding compound 342 from leaking out of the sealing chamber. Care should be taken to ensure no shreds of fiber are left clinging to the side wall of the sealing chamber or to the conductors. Such shreds when imbedded in the sealing compound may form leakage channels. The completed dam should be even with an internal bushing 350 , also referred to as a conduit stop. For the horizontal fitting, no dams are required, but may be used if desired.
[0021] [0021]FIG. 4 shows vertical fitting 310 with a plug 410 installed quickly after the compound is inserted, and it shows the compound in a fully expanded state at 420 . The compound works its way between conductors as it expands to ensure that none are touching each other when the compound is fully expanded. An explosion proof seal is formed. The term “explosion proof” refers to normally encountered explosive environments. It is not meant to cover environments not normally anticipated in environments where such fittings are utilized. | An expanding compound is used to seal conduit fittings. The compound is injected into the fitting, and expands to separate conductors within the fitting. In one embodiment, the compound expands to four times its size, and hardens within approximately one hour. In a further embodiment, the compound is a two-part product that is mixed in a self contained applicator and injected into the fitting. | 5 |
This application is a continuation application of application Ser. No. 346,225, filed May 2, 1989 which is now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a burner for a chemical reactor more particularly for the manufacture of synthetic gas i.e. synthesis gas.
This burner may convey several fluids separately into the reaction zone.
The burner of the present invention may be used more particularly in the method of partial flame oxidation of hydrocarbons, for manufacturing synthetic gas. It may be mentioned that methods of this type are already applied by Texaco, Shell, . . . By synthetic gas is meant here a mixture of H 2 , CO, as well as N 2 , CO 2 , water vapor . . .
The reactor for this use is formed of a burner and a combustion chamber. The device for quenching the gas may also be an integral part of the reactor. After the combustion, a filling, catalyst or other, may also be placed in the reactor.
The burner of the present invention may be supplied by gaseous or liquid fuel or solid fuel in suspension and by a combustion sustaining means or an oxidizer, air, oxygen or enriched air. Steam may be added in variable proportions to the oxidizer or more generally to the fuel. The gases introduced may be preheated to a greater or lesser degree. The preheating increases the yield of the reactor. By way of example, optimum yield is obtained with natural gas, air and steam, for an O 2 /C ratio between 0.60 and 0.65 for pressurized operations. With preheating greater than 500° C., the H 2 O/C ratio has little influence between 0.05 and 3. It is optimum towards 1. The steam reduces the formation of soot.
For special uses, the O 2 /C ratio may go below 0.6 and beyond 0.65 (up to 1 for example).
Modern methods operate at pressures which may reach 80 bars.
Combustion is as a whole adiabatic.
It must provide the theoretic reaction :
CxHy+x/2 O.sub.2 →x CO+y/2 H.sub.2
but is always accompanied by the formation of CO 2 and H 2 O in variable proportions. Thus, the adiabatic balance temperatures may be locally exceeded. Thus, with pure oxygen, temperatures may be met locally very much greater than 1500° C.
The burners proposed are in general tubular or more complex. The simplest technology is represented by two concentric tubes. In this case, the tubes have dimensions (several tens of millimeters) very much greater than the flame front thicknesses. It is then indispensable to let an appreciably residence time elapse (about a second and more) in order to reach the thermodynamic balance. The reactor then comprises zones of high heterogeneity with recirculation of combusting gases.
The multiplicity of tubes would provide a better homogeneity but the number of tubes remains limited for industrial applications. In addition, industrial construction from ceramic remains delicate with tubes. The metal tubes receive the impacts of the hot gas recirculation nuclei and their resistance is affected thereby if there is no cooling.
SUMMARY OF THE INVENTION
The present invention provides a burner with holes which overcome these drawbacks.
The burner comprises orifices or passages opening at different depths or levels depending on the nature of the fluid which it is desired to introduce therein.
The burner may be formed in a single piece or by the juxtapositioning or superpositioning of several elements.
These elements may be made from metal, ceramic or any other refractory material.
In addition, the present invention makes it possible to readily form a large number of holes or passages whereas the use of tubes (in comparable number) is delicate.
With the present invention, a large sized burner may be formed. It also makes it possible to convey, to the reaction zone and without complication, more than two fluids to the burner nose.
This gives an additional regulation flexibility in the case of synthetic gas but may also be used for other purposes : the intake of fuel and oxidizer through two types of passages so as to better control the flames in so far as their form, nature or composition are concerned.
Thus, the present invention makes it possible to convey a third product through the passages of a third type, this product being intended to react in the flame.
The present invention makes it possible to readily maintain hot sealing of the burner.
In addition, the burner of the present invention is easy to machine when it comprises several blocks or solid elements and it has good resistance to high temperatures for ceramic material elements.
The burner of the present invention may be used for directly preheating the fluids.
The burner of the present invention may be readily cooled in the case of metal parts.
The burner of the invention is perfectly suited to the manufacture of synthetic gases from oxygen and methane.
The burner of the invention may be advantageously applied to the method and device described in the European patent application no. 87 402 929.1 filed on 18 Dec. 1987.
Thus, the present invention relates to a burner of a synthesis gas producing reactor for conveying at least two fluids separately to a reaction zone of the reactor, one serving as fuel and the other as combustive gas. This burner is characterized in that it comprises at least one solid element in which holes or passages are provided penetrating to different depths, these holes opening at one of their ends into the reaction zone of the reactor and at the other either into fuel feed means or into oxidizer feed means depending on the fluid conveyed through the hole considered.
At least one group or assembly of passages for feeding the same fluid may open at the same depth in the feed means concerned.
One of the feed means may comprise a chamber partially defined by one of the faces of the solid element.
One of the feed means may comprise a network of channels, joining together, through the solid element, at least some of the holes conveying the same fluid.
The network of channels may comprise passages which communicate together substantially in the vicinity of the central part of the solid element.
The solid element portion of the burner may comprise several superimposed solid blocks or elements fitted together.
At least one of the solid elements may comprise grooves or notches for feeding at least some of the fluid conveying passages.
The solid element may comprise a circuit for the circulation of a heat-carrying fluid or coolant, e.g., A heat transfer medium.
Some at least of the passages may be formed by bores.
The burner may comprise a ceramic material.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be better understood and these advantages will be clearer from the following description of particular examples, which are in no wise limitative, illustrated by the accompanying figures in which :
FIG. 1 shows schematically a burner conveying two fluids separately to the reaction zone,
FIG. 2 concerns the case where three fluids are conveyed,
FIG. 3 illustrates schematically a case where the burner conveys two fluids to the reaction zone and where it comprises a circuit for the circulation of a cooling fluid,
FIGS. 4 and 5 show the case of a burner comprising at least two blocks and grooves,
FIGS. 6, 7 and 8 show the case of a burner comprising at least two blocks assembled together by studs,
FIGS. 9, 10, 11 and 12 show a burner with three blocks for conveying three different fluids to the reaction zone,
FIG. 13 illustrates a one piece burner for conveying three fluids to the reaction zone,
FIG. 14 represents a one piece burner of a relatively simple construction.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The reference 1 in FIG. 1 designates a burner in its entirety.
This burner comprises a housing 2 in which is placed a solid element 3 which in which there are formed different gas passages or holes.
In FIG. 1, the solid element comprises holes 4 for conveying a first fluid and holes 5 for conveying a second fluid. These holes convey the gases towards a reaction zone 10.
In the case of FIG. 1, housing 2 comprises at its lower part a truncated cone shape 6 which defines with the solid element 3 a chamber 7 which may serve as chamber for feeding holes 4 with a first fluid. Conduit 8 feeds chamber 8 with a first fluid.
Of course, this chamber 7 may have other forms than the truncated cone shape.
The solid element 3 rests, in the case of FIG. 1, on an abutment surface 9 which may be formed, still in the case of FIG. 1, by the upper peripheral zone of the truncated cone shape chamber 7.
Holes 4 conveying the first fluid pass through the solid element 3 from one side to the other thus allowing the transfer of the fluid between the truncated cone shaped chamber and the reaction zone 10.
Holes 5 for conveying the second fluid extend from the reaction zone 10 to an intermediate level 11. In the case of FIG. 1, all the holes 5 stop more or less at the intermediate level.
These holes 5 communicate together through transverse channels or holes 12.
Of course, these transverse holes 12 do not pass through the holes 4 conveying the first fluid.
In the case of FIG. 1, the transverse holes 12 communicate with a chamber 13 which may be annular particularly in the case where housing 2 advantageously has a cylindrical shape.
This chamber 13 is fed with a second fluid through conduit 14.
Sealing between the first fluid supply circuit and the second fluid supply circuit may be provided by the precision of fitting the solid element 3 in housing 2 or by the use of seals, or even by welding.
FIG. 2 shows another example which differs from the preceding example in that it comprises holes 15 for conveying a third fluid.
Holes 15 are fed by a chamber 17 of the same type as chamber 13 but situated at another level.
Holes 15 stop at an intermediate level 16 different from level 11 of the intermediate chamber 13.
This chamber 17 communicates with holes 15 through transverse channels or holes 18.
Of course, the circuits of the first, second and third fluids do not intersect but all three open into the reaction zone 10.
Reference 19 designates the conduit feeding chamber 17 with the third fluid.
As has already been mentioned, sealing between the different circuits is provided either by precise fitting of element 3 in housing 2 or by the use of seals or even by welding.
Reference 20 designates a flange for holding the solid element 3 in position.
FIG. 3 concerns a burner which differs from the example corresponding to FIG. 1 by the presence of a cooling circuit.
In FIGS. 1, 2 and 3 the identical parts bear the same references.
The channels or holes 21 are transverse passages which do not communicate with the reaction zone 10.
These channels serve for the circulation of a heat-carrying fluid or coolant.
Such circulation allows the solid element to be cooled or heated.
These channels 21 are fed with heat-carrying fluid from a duct 22. Conduit 23 designates the discharge conduit for the heat-carrying fluid circulating through holes 21.
The heat-carrying fluid holes may be fed from a supply chamber and be emptied by another chamber, these two chambers being separate so that there is effectively circulation of the heat-carrying fluid in the solid element 3.
Of course, the heat-carrying fluid circuit does not communicate with the other circulation circuits.
The solid element 3 may be formed as a single block or by using several superimposed blocks.
In the case where the solid element 3 is made using a single block, the holes conveying the different fluids as well as the transverse holes or channels may be formed by bores.
FIG. 5 illustrates the case of a solid element 3 comprising two superimposed blocks 24 and 25.
FIG. 4 is a partial top view of FIG. 5 which itself is a partial section A--A of FIG. 4.
Holes 26 serve for conveying the first fluid to the reaction zone and holes 27 for conveying the second fluid to this same reaction zone.
Block 24 or upper block comprises holes 27 substantially over the whole of their length and holes 26 over only a part of their length whereas block 25 or lower block comprises only a part of the length of holes 26.
Thus, in this embodiment (FIGS. 4 and 5), when blocks 24 and 25 are assembled together holes 26 appear over their whole length. Of course, blocks 24 and 25 must be assembled together so that there is correspondence between the hole portions 26 contained in the upper block 24 and the portions of these same holes contained in the lower block 25.
Grooves or notches 28 are formed in the upper block 24 at the level of its bearing face 29 with the lower block 25.
In the case of FIGS. 4 and 5, these grooves are perpendicular with each other and provide communication between the different holes 27 conveying the second fluid.
Of course, the form of the grooves and their arrangement may be different from those shown in FIGS. 4 and 5 as long as they allow the different holes conveying the second fluid to be fed from the supply chamber.
Grooves 28 are provided so as not to penetrate into holes 26 conveying the first fluid. Thus, holes 26 are surrounded by a sufficient thickness of material 29.
Of course, the grooves may be formed in the lower block or partially in both blocks without departing from the scope of the present invention.
FIGS. 6 and 7 shows another embodiment.
Reference 30 designates the holes conveying the first fluid and reference 31 the holes conveying the second fluid.
The solid element 32 which comprises these holes 30 and 31 is formed of two blocks 33 and 34, one 34 being placed above the other 33, see FIG. 6.
FIG. 7 shows the upper block 34 in a partial bottom view and FIG. 8 a partial top view of the lower block 33.
The upper block comprises bosses 35 or studs which surround the holes conveying the first fluid over a portion of their length.
When the upper block 34 is placed on the lower block 33, the free zones 36 between bosses 35 define a network of holes 31 conveying the second fluid.
The two blocks 34 and 33 are superimposed so that the portion of the length of the holes conveying the first fluid which are situated in the upper block 34 are opposite the portion of the length of this same hole situated in the lower block 33.
One way of guaranteeing the coincidence of the length portions of the holes conveying the first fluid is to provide, in the lower block 33, recesses 37 into which a part only of bosses 35 penetrates so as to form a sufficient space for the circulation of the second fluid feeding the holes 31 conveying the second fluid.
The supply network defined by the free spaces 36 may be fed from chambers, which may be annular, in the same way as in the case of the example of FIG. 1.
FIGS. 10 and 12 illustrate one embodiment of a burner in which fuels are conveyed separately from three different intakes 38, 39 and 40 and which comprises three blocks 41, 42 and 43 forming the solid element 44. The parts common to FIGS. 10 and 1 to 3 bear the same numerical references. Thus, reference 6 designates the truncated cone shape 7, reference 9 designates the abutment surface for the solid element 44, and reference the holding flange.
The fluids coming through intakes 38, 39 and 40 are designated respectively by first fluid, second fluid and third fluid.
FIG. 9 shows a top view of the burner of FIG. 10 which is itself a sectional view through line BB of FIG. 9.
FIG. 11 is a bottom view of the upper block 43 and FIG. 12 a view of the intermediate block 43.
References 45, 46 and 47 designate respectively the holes conveying the first, second and third fluids.
The upper block 43 comprises the holes 47 conveying the third fluid as well as grooves 48 for feeding these holes 47 from chamber 49. Considering the shape of grooves 48 shown in FIG. 11, chamber 49 must supply all the grooves, which may be obtained by an annular shape of this chamber 49.
In another variant, the upper block 43 may have a shoulder on its lower face into which an intake 49 emerges and defines an annular chamber with a portion of the upper face of the intermediate block and housing 2.
The upper block 43 comprises, over a part 46a of their length, the holes 46 conveying the second fluid. The other part 46b of these holes is placed in the intermediate block 42. Holes 46 are fed through grooves 50 situated on the lower face of the intermediate block 42, see FIG. 12. These grooves form a network for supplying holes 46 from the intake 39 of the second fluid.
In FIG. 12, it can be seen that grooves 50 converge towards the central part 51 of the intermediate block 42.
Thus, the supply chamber 52 may be reduced if required.
The holes 45 conveying the first fluid pass through the solid element 44 from one side to the other. They pass over a part of their length 45a, 45b and 45c respectively through the upper, intermediate and lower blocks and open into chamber7.
Of course, blocks 41, 42 and 43 are located and judiciously positioned during assembly so that holes 45 and 46 are correctly supplied with fluid.
FIG. 13 shows an embodiment corresponding to that of FIG. 10 but only comprising a single block 53 forming the solid element 54. This element comprises bores 55 forming the holes conveying the third fluid which intersect radial bores 56 supplying these bores 55.
The radial bores open into a groove 57 which is in relation with the intake 40 of the third fluid.
Holes 58 for feeding the second fluid are formed by axial bores which open into radial bores 59 forming the channels supplying holes 58 which they intersect.
The radial bores 59 communicate together either by opening into the central part 60 or through a groove 61 which communicates with the intake 39 of the second fluid.
It is obvious that bores 56 may also be convergent and communicate with each other at the central part of the solid element.
The same goes for grooves 48 in FIG. 10.
Finally, the single block of the solid element 44 shown in FIG. 13 comprises bores 62 which pass completely therethrough and serve as holes conveying the first fluid.
In the embodiments shown in FIGS. 10 and 13, the solid element has a cylindrical shape and the feed holes are generally placed on radial half axes offset with respect to each other so as to avoid interconnection of the holes serving for conveying fluids which should not be mixed before arriving in the reaction zone 10.
It is obvious that without departing from the scope of the present invention, the feed holes may be distributed differently, as long as the fluid supply networks do not communicate with each other. This may be obtained by appropriate lay-outs of the channels supplying the conveying holes, such lay-outs may be readily formed when the solid element is made from a stack of several blocks.
FIG. 14 shows a simple embodiment of the device of the present invention.
The burner comprises two parts which are a housing 63 and a solid element 64 with a collar 65 which bears on the upper edge 66 of housing 63.
Furthermore, housing 63 comprises an abutment surface 67 formed by a recess.
The depth to which the recess is provided with respect to the upper edge 66 of housing 63 is such that it corresponds substantially to the height separating the lower face 68 of the solid element from the lower face 69 of collar 65 of this same solid element, with the interpositioning of seals 70 and 71 placed at the contact zones.
The solid element 63 comprises a second recess 72 placed at a level higher than the preceding one so as to form an annular chamber 73 fed through orifice 75 by a duct 74 feeding the second fluid.
The solid element 64 comprises bores 76 which may be radial and which communicate with chamber 73 and with bores 77, which may be substantially axial and form the holes conveying the second fluid.
The solid element 64 comprises axial bores 78 which form the holes conveying the first fluid, this fluid coming from chamber 79 placed under the solid element 64.
This burner is of a particularly simple construction.
Tests have been carried out with a burner corresponding to that of FIG. 14 made from refractory steel, they gave good results and the soot rate was divided by a factor of 10 with respect to a burner comprising tubes and operating under the same conditions. | The present invention provides a burner for a reactor producing synthetic gas for conveying at least two fluids separately to a reaction zone, one serving as fuel and the other as combustive. It comprises a solid element in which are provided holes penetrating to different depths, these holes opening at one of their ends into the reactor and at the other either into fuel supply means or into combustive supply means depending on the fluid conveyed by the hole considered. | 2 |
BACKGROUND OF THE INVENTION
[0001] The present invention is generally in the field of enhancing an immune response, and particularly relates to the removal of TNF inhibitors in a patient, such as a cancer patient, to promote inflammation and thereby induce remission of the cancer.
[0002] This application claims priority to U.S. Ser. No. 60/164,695, filed Nov. 10, 1999.
[0003] Conventional cancer therapy is based on the use of drugs and/or radiation which kills replicating cells, hopefully faster than the agents kill the patient's normal cells. Surgery is used to reduce tumor bulk, but has little impact once the cancer has metastasized. Radiation is effective only in a localized area.
[0004] The treatments can in themselves kill the patient, in the absence of maintenance therapy. For example, for some types of cancer, bone marrow transplants have been used to maintain the patient following treatment with otherwise fatal amounts of chemotherapy. Efficacy has not been proven for treatment of solid tumors, however. “Cocktails” of different chemotherapeutic agents and combinations of very high doses of chemotherapy with restorative agents, for example, granulocyte macrophage colony stimulating factor (“GM-CSF”), erythropoietin, thrombopoetin granulocyte stimulating factor, (“G-CSF”), macrophage colony stimulating factor (“M-CSF”) and stem cell factor (“SCF”) to restore platelet and white cell levels, have been used to treat aggressive cancers. Even with the supportive or restrictive therapy, side effects are severe.
[0005] Other treatments have been tried in an attempt to improve mortality and morbidity. Vaccines to stimulate the patient's immune system have been attempted, but not with great success. Various cytokines, alone or in combination, such as tumor necrosis factor, interferon gamma, and interleukin-2 (“IL-2”) have been used to kill cancers, but have not produced cures. More recently, anti-angiogenic compounds such as thalidomide have been tried in compassionate use cases and shown to cause tumor remission. In animal studies, compounds inducing a procoagulant state, such as an inhibitor of protein C, have been used to cause tumor remission. New studies have shown that soluble cytokine receptors, such as tumor necrosis factor receptors (“TNF-Rs”) which are released in a soluble form from tumor cells, in high concentrations relative to normal cells, may restore the immune system's attack on the tumor cells (Jablonska and Peitruska, Arch. Immunol. Ther. Exp. (Warsz) 1997, 45(5-6), 449-453; Chen, et al., J. Neuropathol. Exp. Neurol. 1997, 56(5), 541-550).
[0006] U.S. Pat. No. 4,708,713 to Lentz describes an alternative method for treating cancer, involving ultrapheresis to remove compounds based on molecular weight, which promotes an immune attack on the tumors by the patient's own white cells.
[0007] Despite all of these efforts, many patients die from cancer; others are terribly mutilated. It is unlikely that any one therapy will be effective to cure all types of cancer.
[0008] It is therefore an object of the present invention to provide a method and system for treatment of solid tumors.
[0009] It is a further object of the present invention to provide a method and compositions that does not involve non-selective, extremely toxic, systemic chemotherapy.
SUMMARY OF THE INVENTION
[0010] A method to treat disorders characterized by production of soluble TNF receptors, such as many types of cancer, and certain diseases such as HIV, where the disease immunosuppresses the patient, has been developed. Antibodies which bind to TNF receptor, including the soluble TNF receptor, are administered to the patient in an amount effective to neutralize the molecules which block binding of TNF to the receptor, thereby inducing inflammation. In the preferred embodiment, the patient's blood is passed through a column having antibodies immobilized thereon, which bind to and remove the soluble TNF receptor molecules. The process can be performed alone or in combination with other therapies, including radiation, chemotherapy (local or systemic, for example, treatments using alkylating agents, doxyrubicin, carboplatinum, cisplatinum, and taxol, and other drugs which may be synergistic in effect with “unblocked” cytokines: or anti-angiogenic factors. Antibodies may be utilized which are immunoreactive with one or more of the following:
[0011] tissue necrosis factor receptor-1 (“TNFR-1”), tissue necrosis factor receptor-2 (“TNFR-2”), interleukin-2 receptor (“IL-2R”), interleukin-1 receptor (“IL-1R”), interleukin-6 receptor (“IL-6R”), or interferon-gamma receptor (“sIFN-gammaR”). The patient is preferably treated daily for at least three weeks, diagnostic tests conducted to verify that there has been shrinkage of the tumors, then the treatment regime is repeated as needed.
DETAILED DESCRIPTION OF THE INVENTION
[0012] Innate, natural and antigen specific killer mechanisms represent the best arsenal for dealing with melanoma cells in vitro and in vivo. Central to these cellular destructive mechanisms is tumor necrosis factor (TNF-), an inflammatory cytokine produced by macrophages and earlier mononuclear cells and TNF-, a related cytokine produced and secreted by killer T-lymphocytes with highly selective antigen specific receptors, Old L. J., Antitumor activity of microbial products and tumor necrosis factor, and Bonavida B, et al., (eds): Tumor Necrosis Factor/Cachecin and Related Cytokines, Basell, Karger, 1988. p7; Haranaka K., et al, Cytotoxic activity of tumor necrosis factor (TNF) on human cancer cells in vitro, Jpn J Exp Med 1981; 51:191; Urban J. L. II, et al., Tumor necrosis factor: A potent effector molecule for tumor cell killing by activated macrophages, Proc Natl Acad Sce USA 1986; 83-5233; Philip R., et al., Tumor necrosis factor as immunomodulator and mediator of monocyte cytotoxicity induced by itself, Gamma-interferon and Interleukin-1 , Nature 1986; 323:86; Ziegler-Heitbrock H. W., et al., Tumor necrosis factor as effector molecule in monocyte-mediated cytotoxicity, Cancer Res 1986; 46:5947; and Feinman R., et al., Tumor necrosis factor is a important mediator of tumor cell killing by human monocytes, J Immunol 1987; 138:635. They derive from billions of clones, each with its own specificity. Thus, one clone of these thymus derived lymphocytes gives rise to T-killer (cytotoxic lymphocytes), or other functional classes each with the one specificity of the parent clone. Their mechanisms are related to both antibody dependent and antibody independent cellular tumor toxicity. Receptors for TNF on neoplastic, viral infected, aged cells or those otherwise targeted for destruction can be both a blessing and a curse. In a positive role, they allow binding of TNF to the surface for internalization and destruction of the cell. Unfortunately this receptor hypothesis has a double edge. Certain neoplastic cells such as active melanomas secrete large amounts of these receptors (sTNF-R1 and sTNF-R2) that promptly bind TNF before it can get within the vicinity of the cell, Haranaka K., et al, Cytotoxic activity of tumor necrosis factor (TNF) on human cancer cells in vitro, Jpn J Exp Med 1981; 51:191; Urban J. L. II, et al., Tumor necrosis factor: A potent effector molecule for tumor cell killing by activated macrophages, Proc Natl Acad Sce USA 1986; 83-5233; Philip R., et al., Tumor necrosis factor as immunomodulator and mediator of monocyte cytotoxicity induced by itself, Gamma-interferon and Interleukin-1 , Nature 1986; 323:86; Ziegler-Heitbrock H. W., et al., Tumor necrosis factor as effector molecule in monocyte-mediated cytotoxicity, Cancer Res 1986; 46:5947; and Feinman R., et al., Tumor necrosis factor is a important mediator of tumor cell killing by human monocytes, J Immunol 1987; 138:635. This serves as a defense mechanism on the part of the targeted cell rendering the host immune system ineffective. TNF-R1 and R2 have been characterized with respect to molecular weights (55 and 75 kD respectively), Old L. J., Antitumor activity of microbial products and tumor necrosis factor, and Bonavida B, et al., (eds): Tumor Necrosis Factor/Cachecin and Related Cytokines, Basell, Karger, 1988. p7, Langkopf F., et al., Soluble tumor necrosis factor receptors as prognostic factors in cancer patients, Lancet 1994; 344:57-58; Howard S. T., et al., Vaccinia virus homologues of the Shope fibroma virus inverted terminal repeat proteins and a discontinuous ORF related to the tumor necrosis factor receptor family, Virology 1991; 180:633-664; Mathias S, et al., Activation of the Sphingomyelin signaling pathway intact EL4 cells and in a cell-free system by IL-1b, Science 1993; 259-519-522; and Andrews J. S., et al., Characterization of the receptor for tumor necrosis factor (TNF) and lymphotoxin LT) on human T lymphocytes: TNF and LT differ in their receptor binding properties and the induction of MHC class I proteins on a human CD4+ T cell hybridoma, J Immunol 1990; 144:2582-2591. They serve to both down regulate the immune response in a normal fashion and overly suppress the immune response as stated above with respect to certain malignancies. They are particularly abundant, and at high level, in patients with melanoma.
[0000] I. Anti-Cytokine Receptor Molecules.
[0013] Selective removal or neutralization of the soluble cytokine receptors (which function as inhibitors of the cytokine) can be used to promote a selective, safe inflammatory response against a tumor or cells infected with a pathogen such as a virus like HIV or parasite. The neutralizing agent is typically an antibody reactive with the receptor. the antibodies will typically be reactive with both the soluble and immobilized forms of the receptor. These include soluble tumor necrosis factor receptor (“sRNF-R”), soluble interleukin-2 receptor (“sIL-2R”), soluble interleukin-1 receptor (“sIL-1R”), soluble interleukin-6 receptor (“sIL-6R”), or soluble interferon-gamma receptor (“sIFN-gammaR”). The advantage of selective removal or neutralization is that the same beneficial effect is obtained in treatment of the disorder but the treatment is much less expensive and safer since exogenous plasma or albumin does not have to be administered to the patient when there is selective removal, as in the case of ultrapheresis and the cytotoxic effects of radiation and chemotherapy are avoided.
[0014] The receptors can be removed by binding to the cytokine, an epitope thereof, or an antibody to the receptor. The antibodies to the receptors can be immobilized in a filter, in a column, or using other standard techniques for binding reactions to remove proteins from the blood or plasma of a patient, or administered directly to the patient in a suitable pharmaceutically acceptable carrier such as saline. As used herein, antibody refers to antibody, or antibody fragments (single chain, recombinant, or humanized), immunoreactive against the receptor molecules. In the most preferred embodiment, the antibody is reactive with the carboxy-terminus of the shed receptor molecules, thereby avoid concerns with signal transduction by the receptor is still present on the cell surface.
[0015] Antibodies can be obtained from various commercial sources such as Genzyme Pharmaceuticals. These are preferably humanized for direct administration to a human, but may be of animal origin if immobilized in an extracorporeal device. Antibodies may be monoclonal or polyclonal. The antibodies and device should be sterilized and treated to remove endotoxin and other materials not acceptable for administration to a patient.
[0016] Antibodies to the receptor proteins can be generated by standard techniques, using human receptor proteins. Antibodies are typically generated by immunization of an animal using an adjuvant such as Freund's adjuvant in combination with an immunogenic amount of the protein administered over a period of weeks in two to three week intervals, then isolated from the serum, or used to make hybridomas which express the antibodies in culture. Because the methods for immunizing animals yield antibody which is not of human origin, the antibodies could elicit an adverse effect if administered to humans. Methods for “humanizing” antibodies, or generating less immunogenic fragments of non-human antibodies, are well known. A humanized antibody is one in which only the antigen-recognized sites, or complementarily-determining hypervariable regions (CDRs) are of non-human origin, whereas all framework regions (FR) of variable domains are products of human genes. These “humanized” antibodies present a lesser xenographic rejection stimulus when introduced to a human recipient.
[0017] To accomplish humanization of a selected mouse monoclonal antibody, the CDR grafting method described by Daugherty, et al., (1991) Nucl. Acids Res., 19:2471-2476, incorporated herein by reference, may be used. Briefly, the variable region DNA of a selected animal recombinant anti-idiotypic ScFv is sequenced by the method of Clackson, T., et al., (1991) Nature, 352:624-688, incorporated herein by reference. Using this sequence, animal CDRs are distinguished from animal framework regions (FR) based on locations of the CDRs in known sequences of animal variable genes. Kabat, H. A., et al., Sequences of Proteins of Immunological Interest, 4 th Ed. (U.S. Dept. Health and Human Services, Bethesda, Md., 1987). Once the animal CDRs and FR are identified, the CDRs are grafted onto human heavy chain variable region framework by the use of synthetic oligonucleotides and polymerase chain reaction (PCR) recombination. Codons for the animal heavy chain CDRs, as well as the available human heavy chain variable region framework, are built in four (each 100 bases long) oligonucleotides. Using PCR, a grated DNA sequence of 400 bases is formed that encodes for the recombinant animal CDR/human heavy chain FR protection.
[0018] The immunogenic stimulus presented by the monoclonal antibodies so produced may be further decreased by the use of Pharmacia's (Pharmacia LKB Biotechnology, Sweden) “Recombinant Phage Antibody System” (RPAS), which generated a single-chain Fv fragment (ScFv) which incorporates the complete antigen-binding domain of the antibody. In the RPAS, antibody variable heavy and light chain genes are separately amplified from the hybridoma mRNA and cloned into an expression vector. The heavy and light chain domains are co-expressed on the same polypeptide chain after joining with a short linker DNA which codes for a flexible peptide. This assembly generated a single-chain Fv fragment (ScFv) which incorporates the complete antigen-binding domain of the antibody. Compared to the intact monoclonal antibody, the recombinant ScFv includes a considerably lower number of epitopes, and thereby presents a much weaker immunogenic stimulus when injected into humans.
[0019] The antibodies can be formulated in standard pharmaceutical carriers for administration to patients in need thereof. These include saline, phosphate buffered saline, and other aqueous carriers, and liposomes, polymeric microspheres and other controlled release deliver devices, as are well known in the art. The antibodies can also be administered with adjuvant, such as muramyl dipeptide or other materials approved for use in humans (Freund's adjuvant can be used for administration of antibody to animals). In the preferred embodiment, antibodies are immobilized to a solid support, such as the SEPHAROSE™ column in the examples, using standard techniques such as cyanogen bromide or commercially available kits for coupling of proteins to membranes formed of materials such as nitrocellulose or polycarbonate.
[0020] Treatment is conducted over a period of time until a positive indication is observed. This is typically based on diagnostic tests which show that there has been some reduction in tumor size or which suggests tumor inflammation. The patient is preferably treated daily for three weeks, diagnostic tests conducted to verity that there has been shrinkage of the tumors and/or inflammation, then the treatment regime is repeated.
[0021] Surgical (or vacuum) removal of necrotic material may be required prior to or during treatment to avoid toxicity associated with high tumor burden.
[0000] II. Treatment with Adjuvant Therapies
[0022] It would clearly be advantageous to cause complete remissions. Based on the presumed mechanism that the process is removing immune inhibitors produced by the tumors, especially inhibitors of cytokines and other immune mediators, it is possible to treat the patients with adjuvant or combination therapies, that enhance the results achieved with the ant6ibodies to TNF receptors. These include anti-angiogenic compounds, such as thalidomide, procoagulant compounds, cytokines and other immunostimulants. Standard chemotherapeutic agents and/or radiation can also be used with the ultrapheresis with the antibody treatment.
[0023] A. Anti-Angiogenic Compounds
[0024] Any anti-angiogenic compound can be used. Exemplary anti-angiogenic compounds include O-substituted fumagillol and derivatives thereof, such as TNP-470, described in U.S. Pat. Nos. 5,135,919, 5,698,586, and 5,290,807 to Kishimoto, et al.; angiostatin and endostatin, described in U.S. Pat. No. 5,290,807, 5,639,725 and 5,733,876 to O'Reilly; thalidomide, as described in U.S. Pat. Nos. 5,629,327 and 5,712,291 to D'Amato; and other compounds, such as the anti-invasive factor, retinoic acid, and paclitaxel, described in U.S. Pat. No. 5,716,981 to Hunter, et al., and the metalloproteinase inhibitors described in U.S. Pat. No. 5,713,491 to Murphy, et al. Thalidomide is administered once daily, 200 mg orally.
[0000] B. Procoagulant Compounds
[0025] Protein C is a vitamin K-dependent plasma protein zymogen to a serine protease. Upon activation it becomes a potent anticoagulant. Activated protein C acts through the specific proteolysis of the procoagulant cofactors, factor VIIIa and factor Va. This activity requires the presence of another vitamin K-dependent protein, protein S, calcium and a phospholipid (presumably cellular) surface. As described in Hemostasis and Thrombosis: Basic Principles and Clinical Practice 2nd Ed., Colman, R. W., et al., p. 263 (J. B. Lippincott, Philadelphia, Pa. 1987), protein C circulates in a two-chain form, with the larger, heavy chain bound to the smaller light chain through a single disulfide link. Protein C is activated to activated protein C (APC). Thrombin is capable of activating protein C by the specific cleavage of the Arg 12 -Leu 13 bond in the heavy chain. In vivo, in the presence of physiological concentrations of calcium, the rate of this activation is enhanced dramatically when thrombin is bound to the endothelial cell cofactor, thrombomodulin. Matschiner, et al., Current Advances in Vitamin K Research , pp. 135-140, John W. Suttie, ed. (Elsevier Science Publishing Co., Inc. 1988) have further reviewed the role of the Vitamin K dependent proteins in coagulation.
[0026] Blockage of the natural anticoagulant pathways, in particular the protein C pathway, uses the natural procoagulant properties of the tumor to target the tumor capillaries for microvascular thrombosis, leading to hemorrhagic necrosis of the tumor, as described in U.S. Pat. No. 5,147,638 to Esmon, et al. Examples of such compounds include anti-protein C and anti-protein S.
[0027] C. Cytokines
[0028] The biologic activity and clinical effectiveness of pro-inflammatory cytokines is augmented by ultrapheresis in the patient with cancer and other states of acquired immune tolerance Specifically, both TNF alpha and TNF beta, in doses of between approximately 100 to 500 micrograms per meter squared body surface area (M2BSA), can enhance the immune reaction in aggressive tumors. Monocyte and lymphocyte activation is augmented by INF-alpha, INF-beta and gamma. The IL-1 and IL-2 receptor antagonists are removed by ultrapheresis and thereby upregulate the in vivo activity of these cytokines. An 80 kD glycoprotein, which is responsible for inhibiting blastoid transformation in advanced malignancy, chronic infectious disease and pregnancy, has recently been found, and appears to be responsible for the loss of delayed hypersensitivity reactions in these diseases, which is removed by this process. This is significant because in removing this type of suppression, vaccines of all types will work better. Dosage regimes for IFN-alpha and beta are 3 M units subcutaneous three times a week up to 20 M units/M2 BSA daily. Interferon-gamma is administered in a dosage of between 100 to 1000 micgms per day.
[0029] D. Chemotherapeutic Agents
[0030] Preferred chemotherapeutic agents are those which are synergistic with TNF, for example, alkylating agents, doxyrubicin, carboplatinum, cisplatinum, and tomoxifen. Tamoxifen plays a role not only in blocking of estrogen receptors but also certain growth factor receptors such as epidermal derived growth factor (“EDGF”), fibroblast derived growth factor (“FDGF”), tumor derived growth factor (“TDGF”), TDGF-β and platelet derived growth factor (“PDGF”) and therefore may be complementary to inflammation against cancers provoked by ultrapheresis.
[0031] E. Radiation
[0032] Radiation therapy is destructive of normal tissue, causing tumors to die partially by an inflammatory attack. Ultrapheresis allows the use of lower doses of radiation to kill residual tumor cells and spare normal tissue. In a preferred method, ultrapheresis is used as the initial therapy, followed by radiation at approximately one-half of the normal dosages. It is well established that TNF kills tumor cells by generating free oxygen radicals, hydroxyl radicals and halide ions, and that radiation therapy generates carbonium ions in tissue. Therefore the combination of the two is more effective in killing cancer cells than either alone.
III. EXAMPLES
Example 1
Treatment of a Patient with Ultrapheresis having Antibodies Immobilized on the Filter
[0033] Materials and Methods
[0034] Monoclonal antibody was obtained from R&D Systems, Minneapolis, Minn., and purified for administration to a patient. This antibody is reactive with TNF R1 and R2 inhibitors.
[0035] A filtration system was assembled using an Eva Flux 4 A filter as the primary filter to remove ultrafiltrate containing these inhibitors from the cancer patient's blood. Monoclonal antibody in a dose of 1 mg per liter of normal ultrafiltrate of the monoclonal antibody and 1 mg of the $2 monoclonal antibody were added to that replacement solution. In this circuit the ultrafiltrate of the initial 4 A filter was delivered by a separate blood pump to a Kuraray 3 A filter. The retentate of the 3A filter was then discarded and the ultrafiltrate of the 3A filter was metered back into the filtered blood from the 4 A filter as replacement solution. To make the discard; i.e., the retentate of the 3 A filter, normal ultrafiltrate with monoclonal antibody added to it was metered into the intra circuit between the 4 A and 3 A filters.
[0036] Results
[0037] Addition of the monoclonal antibodies to ultrafiltrated cancer sera that possess elevated levels of the inhibitors decreases the level of detectable inhibitor by Elias Assay to zero.
[0038] Addition of the monoclonal antibodies to the replacement fluid following ultrapheresis led to an increased reduction of both the soluble receptor to TNF R1 and R2 in the ultrafiltrate of the second filter.
[0039] The purpose of this was to test whether or not this murine monoclonal antibody could capture the inhibitor and aid in its removal from blood since the complex of antibody and antigen could not pass through the pores of the 3 A filter and thus be discarded in the retentate of the 3A filter. This was considerably more effective than the single separation technique and replacement with normal ultrafiltrate. There was also a heightened tumor specific inflammatory response by doing this and an increased rate of tumor destruction. These experiments strongly indicate that the monoclonal antibody, preferably humanized to 97% to 99% human form by substituting human constant regions for human constant regions on the antibody, preserve its capturing and neutralizing capability with the murine variable regions of the antibody and use the antibody as the therapeutic drug in clinical trials with a very high expectation that it would neutralize soluble receptors to TNF and cause tumor destruction in a human.
Example 2
Treatment of a Patient with mAb to TNF Receptors
[0040] A patient with vaginal metastasis of colon cancer was treated for one week with a three hour infusion of monoclonal antibody to TNF receptor 1 and TNF receptor 2. This led to a 75% reduction in the tumor size within one week.
Example 3
Treatment of Melanoma Patient
[0041] A procedure is described in case report form, that utilizes apheresis and immunological affinity chromatography to treat a melanoma patient with short term need and weakening long term prognosis.
[0042] Previous studies utilizing ultrafiltration, with selective pore sieving by passing patient's plasma through cartridges, have been shown to reduce sTNF-R1 and R2 levels. The period of this procedure seems to be of sufficient length to allow TNF to rebound and selectively produce apoptosis or membrane disarray of melanoma cells, Gatanaga T., et al., Identification of TNF-LT blocking factor(s) in the serum and ultrafiltrates of human cancer patients, Lymphokine Res 1990; 9:225-9. Instead of using ultrafiltrate cartridges, this apheresis system was coupled to Sepharose® gel columns in parallel, one of which contained monoclonal human anti TNF-R1 and the second anti TNF-R2. The concept of affinity chromatography preparations has been technically available for protein separation and purification, and improved upon over the past 30 years, Ey, P. L., et al., Isolation of pure IgG 1 , IgG 2a , and IgG 2b . immunoglobulins from mouse serum using protein A-Sepharose, Immunochemistry 1978; 15:429-436. This type of device represents one of the few examples of linking in vivo production of TNF inhibitors to in vitro removal and return of the purified extracted plasma to the patient to prevent fluid reduction.
[0043] The patient is a 55 year old Russian gentleman with metastatic melanoma. The patient smoked 2-3 packs of cigarettes a day for some 20 years. He quit this habit several years ago. He was also a heavy alcohol user in years past but had decreased his intake to 1-2 glasses of wine a day. Review of his medications on this date revealed methylprednisolone 4 mg in AM and 4 mg in PM. Apparently this was being taken as replacement therapy for adrenal cortical suppression that was graded iatrogenically at the time of the treatment of his alveolitis (see below). He was additionally taking narcotic analgesics. As a child he suffered the usual childhood diseases, denies rheumatic fever, scarlet fever or diphtheria. As an adult he has had no major medical illnesses save those described above. He has had no other major surgeries in the past and has no known allergies.
[0044] His history of present illness began in November of 1995 when he noted growth of a right facial naevus which bled and enlarged over the period of one year. This was treated initially by cryotherapy. It regrew within two months and was excised. Histology was that of a malignant melanoma (Clark's level unknown). Staging work up at the time was negative and included CT scans of the head, neck, chest and abdomen. He remained disease free until March of 1996 when he developed right cervical and right submental adenopathy. Preoperative CT scan of the head, neck, chest and abdomen confirmed the right cervical adenopathy but revealed no other sites of metastases. In June of 1996 he underwent re-excision with a right radical neck dissection. In this material, one lymph node was histologically confirmed to involve melanoma. The patient was treated with a course of Vindesine 3 mg/m 2 every three weeks, Dacarbazine 100 mg/m 2 every three weeks for four cycles. He subsequently developed cutaneous metastases in the skin of his left shoulder, multiple metastases to the scars within the left anterolateral neck and multiple axillary metastases treated with fifteen subsequent excisions of recurrent metastases. In March of 1999 he was offered a trial of Interleukin-2 but on this developed severe pulmonary toxicity that had a protracted course and was diagnosed as idiopathic fibrosing alveolitis. Interleukin-2 was discontinued and he received radiation therapy to his right neck and axilla for six weeks beginning in the month of May 1999. He developed low back pain in August of 1999. Work up in October of 1999 revealed bone metastasis of the vertebral body of T-11 and subsequent MRI revealed a lytic destructive process in the right transverse process and pedicle of the 11 th thoracic vertebra, as well as complete replacement of the vertebral body at T-11. Additional metastases were appreciated in the vertebral body of the 9 th thoracic vertebral as well as the 10th. Also there was involvement of L-1 and L-2 vertebral bodies. Tumor seen again on the Mar. 16, 2000 MRI revealed growth posteriorly from the mid body of the 11 th thoracic vertebral into the spinal canal by 7.4 to 7.8 mm with posterior displacement of the spinal cord. CT scan of the chest, abdomen and pelvis revealed possible multiple liver metastases but no other suggestion of visceral metastases.
[0045] The patient was then considered for a trial of UltraPheresis™ in an effort to reduce solubilized receptors to tumor necrosis factor, both sTNF-R1 and sTNF-R2. As facilities for the application of this form of semi-selective plasma exchange did not exist in Moscow at this time, affinity column separation of inhibitors was explored. Monoclonal antibodies against sTNF-R1 and R2 delivered to the Cardiology Research Center in Moscow for Dr. Sergei N. Petrovsky, PhD, head of the group for Affinity Sorbents for Medicine, Pocard, Ltd,. 3-rd Cherepkovskaya str., 15a, Moscow, 121552, Russia. Ninety milligrams of anti sTNF-R1 monoclonal antibody and 180 mg of anti sTNF-R2 monoclonal antibody were then bound with sterile Sepharose® using cyanogen bromide in a glass column previously described for use in the lipopack cholesterol absorbent column technology. The particular methodology used is well described and is commercially available in Russia for the development of these LDL absorbent columns. The columns were prepared under sterile conditions in a GSIO 9,001 facility. They were subjected to endotoxin testing, viral, fungal and bacterial cultures, and prepared for human use under written Informed Consent and under approval of the Kremlin President's Hospital Medical Center.
[0046] On May 2, 2000 the patient's physical examination was that of a well-developed, well-nourished male who appeared his stated years. Examination of his head revealed a normal hair distribution and texture. His tympanic membranes and external auditory canals were clear. The sclerae and conjunctivae were clear. The pupils were round, reactive to light and accommodation. EOM intact. Funduscopic examination was normal. He had a healed graft over his right inferior cheek and extensive scarring over the right anterolateral neck consistent with his history of prior right radical neck dissection. There were no demonstrable pathologic masses within the skin, the scar, or pathologic nodes appreciated either in the cervical nodes or the supraclavicular fossae bilaterally. His lungs were clear to ausculation and percussion. His precordium demonstrated a non-displaced PMI, a normal S1 and S2 without gallop, murmur or rub. With the right arm exhibited there was 3+lymphedema. The right axilla was poorly examined due to extensive scarring in that area but no palpable nodes were appreciated. His abdomen was mildly obese. His liver and spleen were normal to physical examination. His axillary lymphatics were unremarkable. The genitalia was that of a normal mature male without pathologic mass. The lower extremities revealed no edema, cyanosis or clubbing and exhibited full ROM. His neurologic examination included a normal mental status. Cranial nerves 2-12 were intact. His DTR's were 2+ and symmetric. Motor and sensory testing was normal. His cerebellar examination revealed no dysmetria, dysarthria or dysdiadochokinesia. He was essentially confined to bed due to back pain only, but was able to roll from left to right without assistance. He had been confined to a wheelchair for the antecedent two months due to back pain and was wearing a back brace which was removed for physical exam.
[0047] His laboratory parameters included a hemoglobin of 8.8 gms, WBC 2,800 with normal differential. His platelet count was 121,000. The comprehensive metabolic panel was unremarkable and alkaline phosphatase was normal.
[0048] An MRI scan of the patient's 11th thoracic vertebral body revealed a mass placing pressure on the spinal cord. This was taken during the week prior to intensive therapy started in April of 2000 and continuing through May.
[0049] On the first day an 18 gauge plastic cannula was inserted in the left antecubital vein. A second was established in the right greater saphenous vein of the leg. The patient was connected to a standard Cobe Spectra centrifically based plasma separator. Six hundred cc's of plasma was then harvested and replaced with 5% albumin in saline. The patient's plasma was then pumped over column one which contained 45 mg of anti sTNF-R1 monoclonal antibody and then passed to column two which contained 90 mg of anti sTNF-R2 monoclonal antibody. The material eluted from the column was then analyzed for the level of each inhibitor still in the plasma and 50 cc's of that plasma was then injected into the patient at the end of pheresis to look for any febrile reactions or allergic reactions. He tolerated this with no apparent clinical adverse effect.
[0050] Subsequent analyses of the patient's plasma and the eluate of the column revealed that the column was able to capture essentially all of the inhibitor presented to it in this 600 ml plasma volume. The patient was maintained in the hospital over night and on the morning of the 4th of May, he was brought from hospital room back to the apheresis suite. He had a comfortable evening and ate a normal dinner and breakfast. The IV's were re-established in the same sites. The patient was re-attached to the Cobe Spectra machine and on this date, 3 liters of plasma was harvested and delivered to the columns as described above in a continuous fashion until 3 liters of plasma was treated.
[0051] His R1 level before treatment was 1500 and after treatment was 1450. His R2 level before treatment was 5000 and after treatment was 3800 on this date. Again he tolerated the procedure well with no clinical adverse effect and no increase in pain in his back.
[0052] On the third day the 6th of May, the treatment was repeated. Three liters of plasma were again pheresed over the columns in an identical fashion as described above. His pretreatment R1 was 2300, post treatment R1 was 1600. Pretreatment R2 was 5200, post treatment R2 was 3200. At the end of each treatment the columns were washed with glycine buffer at a pH of 2.5 to elute the bound inhibitor from them and measure them quantitatively. It was determined that at these amounts of treated plasma the columns were not saturated and significant quantities of inhibitor removed.
[0053] His fourth treatment was on the 7th of May. He was increased to 4 liters of treated plasma. The procedures were repeated each day with gradual escalations in amount of plasma treated to a maximum treated plasma of 8 liters on the May 10th, 11th, 12th, 13th, and 14th. On May 16 th , two columns were used in parallel, thus increasing the amount of plasma delivered to each column remained at 30 mls per minute, for a total of 60 mls of plasma per minute. This resulted in a pretreatment R1 of 2600 and a post treatment of 1700. R2 pretreatment was 4250 and went to post treatment of 2700.
[0054] He was subsequently treated with 8 liters of plasma a day using the double column method. On the 21st of May he had a repeat CAT scan of his spine which revealed complete resolution of tumor. Three days after that, May 24th, he had a repeat MRI which was compared to the pretreatment MRI and confirmed a complete response. The patient was followed carefully in the hospital by his attending physicians as well as attending neurosurgeons, who followed him on a daily basis concerned about tumor bleeding or tumor swelling in his tight and anatomically dangerous places but fortunately the patient enjoyed a complete response with no apparent adverse effect.
[0055] For the details of daily treatment in terms of volumes, columns, blood flow rates and plasma flow rates see Table 1.
[0056] The patient has enjoyed an apparent complete response without any significant adverse effect. He was able to get up and walk after the fourth procedure. Two additional courses were planned in an endeavor to consolidate this response. This case is consistent with the observations that a salutatory tumor response can be achieved in melanoma by removing solubilized receptors to TNF. This column is so specific that it removes only sTNF-R1 and R2 and that is the only explanation for the response that this man has had from an oncologic point of view. A profound column yield was observed on the third treatment day for sTNF-R2 with modulation for the remaining treatment days throughout this fifteen day course. R1 peaked on treatment day 7 with the total amount removed of 6 million pg. This also modulated throughout the course of treatments but never approached the 16 million mark set by sTNF-R2.
[0057] Radiographic examination on the day following his first fifteen day course of apheresis with anti R1 and anti R2 affinity column extraction revealed no melanoma and considerable reduction of the lesion at the 4th lumbar vertebral body. Currently the patient remains active, with good appetite, is walking normally and his back pain is much improved. He has positive anticipation for his second course of apheretic treatments.
Example 4
Production of Polyclonal Antibodies to STNF R1 and R2 Preparation of Column for Treatment of Patients
[0058] Polyclonal antibodies were produced in New Zealand white rabbits injected with recombinant antigen, soluble tumor necrosis factor receptor (“STNF”) R1 and R, injected into the rabbit on a standard immunization protocol, then boosted. 200 mg of polyclonal antibody may be produced against STNF R1 and R2, per liter. The animals will be bled monthly. 200 mg of antibody can be bound safely to 200 mg of AH SEPHAROSE™ beads. The binding is done with ethanolamine and periodate. Binding is therefore excellent. This matrix is then placed in a 200 mg polycarbonate column. Each step is done in an aseptic fashion and the final product is then terminally sterilized with standard radiation protocols and subjected to USDA standard testing for pyrogen and infectious agents.
[0059] This amount of antibody is enough to remove STNF R1 and STNF R2 in human extracellular water sufficient to reduce the level of 10,000 pg per ml to under 1,000 pg per ml in two to three hours of plasma exchange.
[0060] The use of the columns to reduce inhibitor levels to less than 1000 pg/ml over a period of at least three weeks has resulted in remissions of between 40 and 90% in non-small cell lung cancer, breast cancer and melanoma patients. It is therefore predictable that the treatment results in a rather consistent tumor specific inflammatory response and the majority of patients having the most common tumor types, including breast, small cell lung, colon, ovarian, hepatic, melanoma, and renal cell carcinoma as well as ovarian and endometrial cancers should respond to the treatment. In combination with antibodies against vascular endothelial growth factor receptor and/or epidermal growth factor receptor and/or antibodies against fibroblast derived growth factor and transforming growth factor receptor, either singularly or in combination, the treatment is expected to produce excellent responses in these tumor types and may play a role in the clinical management of hematopoietic disorders as well.
[0061] The methods and systems disclosed herein are useful for treatment of patients with cancer, immune-mediated disorders, chronic parasitism, some viral diseases especially viral diseases such as HIV which cause immunosuppresion, and other disorders characterized by elevated levels of TNF receptors or inhibitors to IL-2, IL-6, gamma interferon, or other pro-inflammatory signals as well as white cell activation. An example demonstrates efficacy in treating a cancer patient.
[0062] Modifications and variations of the method and compositions described herein will be obvious to those skilled in the art. Such modifications and variations are intended to come within the scope of the appended claims. | A method to treat cancer uses ultrapheresis, refined to remove compounds of less than 120,000 daltons molecular weight, followed by administration of replacement fluid, to stimulate the patient's immune system to attack solid tumors. In the preferred embodiment, the patient is ultrapheresed using a capillary tube ultrafilter having a pore size of 0.02 to 0.05 microns, with a molecular weight cutoff of 120,000 daltons, sufficient to filter one blood volume. The preferred replacement fluid is ultrapheresed normal plasma. The patient is preferably treated daily for three weeks, diagnostic tests conducted to verify that there has been shrinkage of the tumors, then the treatment regime is repeated. The treatment is preferably combined with an alternative therapy, for example, treatment with an anti-angiogenic compound, one or more cytokines such as TNF, gamma interferon, or IL-2, or a procoagulant compound. The treatment increases endogenous, local levels of cytokines, such as TNF. This provides a basis for an improved effect when combined with any treatment that enhances cytokine activity against the tumors, for example, treatments using alkylating agents, doxyrubicin, carboplatinum, cisplatinum, and taxol. Alternatively, the ultrapheresis treatment can be combined with local chemotherapy, systemic chemotherapy, and/or radiation. | 0 |
This application is a continuation-in-part application of U.S. patent application Ser. No. 08/153,406, filed Nov. 16, 1993, (now abandoned) which claims priority to German patent application P 43 32 825.3, filed Sep. 27, 1993 and German patent application P 43 33 376.1, filed Sep. 30, 1993.
The present invention relates to immunological techniques and, more specifically to the art of enhancing the natural immune response in animals and humans by combining the injected antigens with improved adjuvant formulations.
BACKGROUND OF THE INVENTION
If proteins or infectious material, called antigens, enter the humoral system of an animal or a human, an immune response occurs which culminates in the formation of antibodies. In many cases the antibody levels generated in the blood are too low for protecting animals or humans against disease, for use in the manufacture of commercial vaccines and for preparing antibodies in scientific research.
Finding methods that assist an organism to make more antibodies is therefore a field of endeavour which has been active for over a century.
DESCRIPTION OF PRIOR ART
Adjuvants for human use consist almost exclusively of a suspension of aluminium hydroxide, a polycationic, insoluble, protein adsorbing colloid.
Adjuvants for use with animals have frequently been developed by building on the very important contribution made by Jules Freund almost half a century ago. Jules Freund namely introduced an adjuvant formulation useful with animals consisting of a cream-like emulsion of a mineral oil (paraffin), synergistically combined with bacterial cell walls from dead mycobacteria such as M. tuberculosis. This became widely known and used as Freund's complete adjuvant (FCA). It is capable of elevating the antibody concentrations in the blood by several orders of magnitude over the natural" response with merely aqueous solutions of the antigen. For a comprehensive review see J. Freund, "The mode of Action of Immunologic Adjuvants" in Advances of Tuberculosis Research 7, 130-48 (1956). Freund's adjuvant is still commonly used in spite of severe drawbacks. The injected mineral oil can, namely, cause heavy and unsightly granulomas leading to the loss of animals. The bacterial material also contributes to undesirable side effects such as fever, granulomas, inflammations and arthritic symptoms H. S. Warren & L. A. Chedid (1988) CRC Critical Reviews in Immunology 8, 83-101!. It is these effects which give rise to ethical reservations against the use of this adjuvant.
Many efforts have been made to emulate Freund's adjuvant in its efficacy and at the same time to avoid the damage evoked by this agent. In the intensive search for a replacement of the bacterial components (Mycobacterium tuberculosis or M. butyricum) it was found that low molecular weight glycopeptide subunits of the bacterial cell wall were about as effective as the native bacteria when applied in the same way as the parent mycobacteria, namely along with oil emulsions. N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP) was the first of the compounds described. F. Ellouz, A. Adam, R. Ciorbaru & E. Lederer (1974) Biochem. Biophys. Res. Commun 59, 1317-25!. More recently a glucosamine homolog of MDP, the N-acetylglucosaminyl-N-acetylmuramyl-L-alanyl-D-isoglutamine (GMDP), has been isolated from Lactobacillus bulgaricus and an efficient method of synthesis has been developed which makes this compound generally accessible. V. Ivanov & T. Andronova (1991) Sovjet Medical Reviews, D. Immunology 4, 1-63 (R. V. Petrov, ed.), Harwood Academic Publishers; USSR Pat 2,543,268; U.S. Pat. No. 4,395,399!. GMDP has found considerable interest as a tumor inhibiting substance and has undergone extensive clinical and toxicological testing for this application.
Thus the cell wall of the mycobacteria that are used in Freund's adjuvant contain glycopeptide subunits such as N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP) and N-acetylglucosaminyl-N-acetylmuramyl-L-alanyl-D-isoglutamine (GMDP), These subunits, i.e. MDP and GMDP, as well as a large number of chemically modified analogs and derivatives, have been investigated for use as adjuvants.
A study of the immunostimulating effect of MDP leads to the statement that 'MDP in saline does not induce DTH' (delayed time hypersensitivity, an indication for immunoresponse) to antigens. Carelli, F. M. Audibert & L. A. Chedid (1981) Infection and Immunity 33, 312-14; Likewise, a lysozymic, cell-wall lysate containing MDP and GMDP amongst others was found to yield no significant increase in antibody count. L. A. Chedid & F. M. Audibert, U.S. Pat. No. 4,094,971! and it has been demonstrated that doses of 100 μm per mouse given in aqueous solution are inactive.
It has been reported that in even more elevated doses (e.g. 500 μg/mouse) MDP acts as an immune suppressor. C. Leclerc, D. Juy, E. Bourgeois & L. Chedid (1979) Cellular Immunology 45, 199-206!.
The use of lipophilic MDP analogs to augment the levels antibody to β-human chorion gonadotropin in rabbits has been studied. Strong local lesions were reported. In doses of 250 μg per rabbit, combined with peanut oil emulsions, antibody yields were obtained, 2,5-7 times higher than those achieved with antigen in water alone. Unmodified MDP was less effective. No comparison was made with Freund's adjuvant H. A. Nash, C. C. Chang & Y. Y. Tsong, (1985) J. of Reproductive Immunology 7, 151-62!.
A study of the adjuvant effect of stearoyl-MDP found that it did not significantly stimulate antibody production, but that it did prime the animals so that when they were boosted two months later, an antibody response was seen which was about 0.3 that produced by Freund's adjuvant. Underivatised MDP in water was not used. P. Sharma et al. (1988) Technological Advances in Vaccine Development, 107, 107-16, Alan Liss Publishers!.
An adjuvant formulation consisting of a threonine analog of MDP in an oil emulsion carrier has been described which is presumably more biocompatible than Freund's adjuvant formulation. A. C. Allison & N. E. Byars (1986) Journal of Immunological Methods 95, 157-68; A. C. Allison & N. E. Byars (1988) Technological Advances in Vaccine Development, 401-9, Alan Liss publishers; The antibody response however is considerably lower than with Freund's adjuvant J. S. Kenney, B. W. Hughes, M. P. Masada & A. C. Allison (1989) Journal of Immunological Methods 121, 157-66!.
The majority of the cited research has concentrated on the use of adjuvant formulations which are related to Freund's formula, consisting of relatively massive doses of thick oil emulsions, and containing MDP or its modifications at doses equivalent to the mycobacteria doses used in Freund's formulations.
The consensus is therefore R. Bomford, (1992) Reviews in Medical Virology 2, 169-74! that as adjuvants they only work together with oil emulsions and in the doses which are similar to the ones which are deemed necessary for the mycobacteria in Freund's adjuvant, and that only chemical modification of the native glycopeptides will make better immunoadjuvants out of them.
FURTHER TECHNOLOGICAL BACKGROUND NOT BELONGING TO THE PRIOR ART
My copending U.S. patent application Ser. No. 08/130,645, corresponding to German patent number 4 231 675 describes work concerned with the use of MDP and GMPD to achieve improved immunoresponse without severe side effects. I have demonstrated that the doses of MDP and GMDP that were used in the cited research and in many other studies were, surprisingly, much too high to be optimally useful. Improved stimulation was shown to occur at doses 100 times lower. Moreover, it was discovered that at these lower doses the oil emulsion was not necessary and that simple aqueous solutions worked just as well or better. The extremely important discovery that simple aqueous solutions can be used is particularly important with regard to the avoidance of side effects.
When going to larger animals the low optimum doses of MDP and GMDP were confirmed, however the absolute antibody yields could not compete with those obtained with Freund's adjuvant, as shown in Table 2. The effect of those glycoppeptides must therefore be improved by some means to be of practical use as components of an adjuvant formulation in livestock and humans.
OBJECTS OF THE INVENTION
It is a first object of the present invention to provide new adjuvant formulations containing MDP and/or GMDP and other components as well as new methods for the use that dramatically enhance the safety, convenience and effectiveness of the glycopeptides as immunostimulants.
A further object of the invention is to achieve a synergistic interaction of the components which rapidly yields high antibody titers without boosting by repeated injections. This object is particularly important where one single injection is most desirable such as in the vaccination of humans and pets. Another object of the invention is to provide adjuvant formulations for veterinary and human medicines which are novel and oil-free and which consist of immunostimulants of very low oral and parenteral toxicity which are applied in low doses, whereby the clinical and industrial safety data of said ingredients are already well established, thus facilitating approval of such formulations for veterinary and human use.
BEST MODE FOR CARRYING OUT THE INVENTION
The invention is based on immunisation experiments performed mainly with rabbits using bovine serum albumin as antigen, and it is centered on the concept of the synergism of two or three different immunomodulators with the notion that true synergism should be a potentiating and not merely an additive effect. Confirmatory tests have been run with other species and antigens in order to examine biocompatibility and to establish more efficient immunisation routines.
In my researches I recognised a guideline for the search of synergists in the fact that GMDP has been found to disappear from an organism very rapidly, being completely metabolised after only eight hours. This short life span is sufficient to trigger the release of various immunostimulating factors such as interleukins and macrophage stimulating polypeptides which influence the events in the immune response. I concluded that enzymes must play a crucial role in all these processes. I decided to focus my attention on substances which could function as coenzymes.
The trace elements copper, manganese, zinc, cobalt and selenium were incorporated in this study. The most pronounced adjuvant effect was found with zinc, and a lesser effect with copper and selenium. Manganese and cobalt had negligible effects.
Furthermore, as already mentioned, the efficiency of Freund's adjuvant also depends on the cream-like oil emulsion prepared from the lipid "Bayol F" or more recently from "Marcol 52", a paraffine fraction essentially consisting of n-dodecane. By a mechanism not yet well understood the parafin oil acts as an immunoadjuvant.
D. Gall (1966) Immunology 11, 669-86 has investigated a considerable number of lipidic substances, mostly amines with varying chain length, from primary to quaternary and has found dimethyl dioctadecyl ammonium bromide (DDA) among the most active ones. In the following two decades DDA has found widespread interest for its potential as an immunoadjuvant and even was applied in humans (cf. Stanfield, Gall, D. & Bracke, P. M. (1973) Lancet 1973, 215-19). However DDA has the same disadvantages as Freund's paraffin oil: it is not biodegradable and therefore upon injection makes long-lasting granulomas (aking nods) and it is cumbersome to use because like paraffin oil it must be sonicated or otherwise homogenized to be distributed in the solution of the antigen. Despite this drawback I decided to first investigate DDA as a model substance and as will be explained in the following found a new way of incorporataing it which overcomes this disadvantage.
The most important result, and the actual core of the present invention, is the finding that the combination of glycopeptides with zinc in the form of an aminoacid complex and with a lipid substance under proper conditions and dosage are able to provoke antibody titers that far exceed the mere additive affect of each individual component and also that of Freund's adjuvant.
Another important aspect is the ease of use of the adjuvant formulation by presenting it as a sterile, solid substance obtained by coevaporating the components from an ethanol solution in the presence of a large excess of amino acids both soluble in ethanol and water, such as L-proline or 5-oxo-L-proline. Upon reconstitution with the aqueous antigen solution, the lipid as a homogenous mixture with the amino acids forms a submicroscopically fine dispersion which readily associates with the protein, thus circumventing the need of input of mechanical energy to form an emulsion with all its disadvantages.
Another aspect is the biocompatibility of the new adjuvant formula achieved by using only minute quantities of the individual components. In the case of Freund's adjuvant one customarily uses 0.5 ml of paraffin oil per rabbit. In the present invention one usses 20 μl lipid per rabbit, i.e. 25000 times less| Without the need to use an emulsion it is possible, with the present invention, to give intravenous adjuvanted immunisations. By frequent repetition of adjuvanted antigen injections, a technique made possible because of the good biocompatibility and the low doses required in the method according to this invention, antibody titers could be reached that were hitherto considered to be unattainable so rapidly and intensely. An analog of DDA was tested which instead of the dioctadecyl residues contained the stearoylhydroxyethyl groups attached to the quaternary nitrogen (Hoe 4243 from Farbwerke Hoechst, 2× recrystallised from ethyl acetate. This is the biodegradable analog of DDA, a so-called esterquat.
Another lipid quaternary ammonium compound was highly purified injectable grade lecithin. The overall immunostimulatory effect was lower than with DDA but is offset by the tremendous advantage that lecithin is a pharmaceutical material suitable and already licenced for parenteral use in other human applications.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram which illustrates the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the work which led to the invention described in U.S. patent application Ser. No. 08/130,645 and in the corresponding German patent 42 331 675, it was established that the optimum dose of GMDP, for a rabbit is 10 μg. It has now been found that to date the optimum immunological adjuvant formulation for one injection for a rabbit comprises the combination of 10 μg GMDP+20 μg DDA+100 μg Zn as a complex with 1,4 mg L-proline for one rabbit injection (Experiment 18 of Table 1). This has been confirmed in a large number of rabbit experiments. The optimum dose of 10 μg GMDP per rabbit has been reconfirmed regardless of the nature of the supplementing synergists. There is indication however, that larger doses of DDA are required with antigens other than BSA and with larger species.
The zinc-L-proline complex was chosen because of the low toxicity of zinc-amino acid complexes as compared to simple salts, because of the high proline content of the new complex (apparently 8 mol proline to 1 atom zinc, but maybe ZnPro 2 solubilised in excess proline) which provides excellent dispersing action of this complex for the DDA which is virtually insoluble in water. The L-proline complex is moreover, as I have found, soluble in alcohol so that it can be coevaporated with the lipid and excess proline to form the solid body of the adjuvant formulation ready for reconstitution with aqueous antigen solution. In the case of lipids insoluble in 65% ethanol such as the Esterquat and cholesteryl stearate, the proline is replaced by 5-oxo-L-proline (pyroglutamic acid) which is well soluble in absolute ethanol. In thiscase the lipid can be dissolved in ethyl acetate and will not precipitate upon addition of the ethanol solution of the 5-oxoproline prior to the coevaporation.
A number of other combinations of immunostimulators have also been investigated, some with good success such as CHAPS, a steroid lipid with a strongly hydrophilic zwitterionic site that might be useful with vey sparesely soluble antigens, or cholestyeryl stearate and α-tocopherol as examples for neutral immunostimulating lipids. However, the potential that becomes available by combining glycopeptides in the right proportion and composition with synergists such as claimed is nearly inexhaustible. The present invention opens the door to further progress in synergistic adjuvant combinations.
EXAMPLE 1
In extended tests with rabbits, the temporal evolution of the anti-BSA titer under the influence of immunostimulants has been investigated and part of the results are shown in Table 1.
In this Table "A relative 28" signifies the antibody titer with adjuvants divided by the antibody titer with Freund's adjuvant after 28 days. The relative antibody titers quoted show three different values for each experiment, namely the A relative 28 values after 28 days, after 42 days and after 56 days, in each case relative to the value with Freund's adjuvant after 28 days. The A rel 28data of day 42 in the experiments 1,3,6-14 and 21 are used in the drawing of FIG. 1. The progress obtained by the present invention is thus illustrated in this drawing which reflects the results shown in Table 1 below. The synergistic action of the individual components in three different adjuvant formulations is clearly demonstrated.
TABLE 1__________________________________________________________________________The time course of the anti-BSA titer in rabbits with various adjuvantformulationsExpt Component of Adjuvant Formulation A.sub.rel 28Nr Glycopeptide Amino acid complex Adjuvant/lipid Day 28 Day 42* Day 56__________________________________________________________________________ 1* 10 μg GMDP 0.1 0.3 0.72 10 μg GMDP + 10 μg Zn + 150 μg Pro 0.5 0.9 1.1 3* 10 μg GMDP + 100 μg Zn + 1.5 mg Pro 0.3 0.5 1.14 10 μg GMDP + 10 μg Cu + 150 μg Pro 0.4 0.9 0.85 10 μg GMDP + 100 μg Zn + 10 μg Cu + 1.7 mg Pro 0.5 1.2 1.1 6* 10 μg Lecithin 0.3 0.6 0.8 7* 20 μg CHAPS 0.5 0.8 0.9 8* 20 μg DDA 0.7 1.8 0.9 9* 10 μg GMDP + 10 μg Lecithin 0.7 1.0 1.110* 10 μg GMDP + 20 μg CHAPS 0.8 0.9 1.011* 10 μg GMDP + 20 μg DDA 1.0 1.3 1.212* 10 μg GMDP + 100 μg Zn + 1.5 mg Pro 10 μg Lecithin 0.8 3.2 3.513* 10 μg GMDP + 100 μg Zn + 1.5 mg Pro 20 μg CHAPS 1.5 4.3 4.414* 10 μg GMDP + 100 μg Zn + 1.5 mg Pro 20 μg DDA 1.3 5.2 4.315 10 μg MDP + 100 μg Zn + 1.5 mg Pro 20 μg DDA 1.1 2.9 3.116 10 μg GMDP + 100 μg Zn + 1.5 mg Pro 20 μg Hoe 4243 esterquat 1.0 4.4 5.217 10 μg GMDP + 100 μg Zn + 1.5 mg Pro 20 μg Cholesteryl stearate 1.1 4.3 4.818 30 μg GMDP + 100 μg Zn + 1.5 mg Pro 20 μg DDA 1.3 5.4 5.819 10 μg GMDP + 100 μg Zn + 1.5 mg Pro 20 μg α-Tocopherol 0.7 2.9 2.920 10 μg GMDP + 100 μg Zn + 1.5 mg Pro 100 μg Dextrane 40 000 0.8 1.0 1.121* Freund's Complete Adjuvant 1.00 0.8 1.8__________________________________________________________________________
It is noted that the zinc proline complex used is that described in Examples 3 (or in Example 4 when using DDA as the lipid), prepared using zinc oxide of pharmaceutical quality, and that when the amino acid complex is an amino acid complex of copper the copper is used in the form of copper carbonate in the place of the zinc oxide. formation of the amino acid complex.
It is now interesting to analyse the information presented in Table 1. Experiment No. 21 gives the antibody titer for rabbits injected with Freund's complete adjuvant after 28 days, 42 days and 56 days. This titer is defined as 1 at 28 days and the relative value at day 42 is found to 0.8, i.e. a reduction relative to the value of 28 days but after 56 days the relative antibody titer has arisen to 1.8
Experiment 1 relates to the use of the optimum dose of GMDP on its own as established from my research and as claimed in the abovementioned U.S. patent application Ser. No. 07/130,645. It will be seen that with 10 μg of GMDP alone the relative antibody titer is 0.1 at day 28, 0.3 at day 42 and 0.7 at day 56. Although the 0.7 value at day 56 is still noticibly below the result obtained by Freund's complete adjuvant it is still a substantial improvement because the animals are not subjected to any particular stress and the mortality rate of the animals is substantially reduced. Experiments 2 to 5 show the results of using the same dose of GMDP with different amounts of divalent metals (in the form of zinc and/or Cu together with L-proline. It will be noted that using these adjuvant formulations better results are obtained than when using GMDP alone, with the best result being the 1.2 value of experiment 5 obtained using 10 μg of GMDP plus 100 μg of zinc plus 10 μg of copper plus 1.7 mg of L-proline. This value is already notably higher than the comparative value using Freund's adjuvant and is also particularly favourable because the mortality rate of the rabbits has significantly reduced and the rabbits are not subjected to the side effects and inherently stress which arises when using Freund's complete adjuvant.
Experiments 6, 7 and 8 show the effect of lecithin, CHAPS and DDA respectively when used alone as an adjuvant. When compared with the previous experiments these results are quite respectable, in particular the result of experiment No. 8 using 20 μg of DDA shows a favourable antibody titer of 1.8 at day 42 which compares very favourably with the value obtained with Freund's complete adjuvant.
Experiments 9, 10 and 11 show the antibody titers which are achieved when using using 10 μg of GMDP in combination with lecithin CHAPS and DDA. It will be seen that the combination of GMDP with lecithin and CHAPS results in slightly improved values over the use of lecithin and CHAPS alone. The combination of GMDP and DDA leads to improvement of the relative antibody titers at days 28 and 56, when compared to lecithin alone, but the value at day 42 is not so favourable as for DDA alone.
Particularly interesting are now the values for the relative antibody titers which are achieved with the experiments 12, 13 and 14 which clearly establish the synergistic effect underlying the present invention. Thus experiment 12 shows the combination of 10 μg of GMDP as glycopeptide plus 100 μg of zinc in the form of the zinc proline complex with 1.5 μg of proline in combination with 10 μg of lecithin. It is noted that the relative antibody titers at days 26, 42 and 56 of 0.8, 3.2 and 3.5 respectively are substantially higher than with a combination of 10 μg of GMDP and 10 μg of lecithin alone, at least with respect to titers at days 42 and 56. The values of 3.2 and 3.5 for days 42 and 56 are substantially better than with Freund's complete adjuvant, are surprisingly high and are obtained without the problematic side effects associated with Freund's complete adjuvant and without any unusual increase in animal mortality.
Since the substances involved can all be considered for human use there is a reasonable prospect that the same adjuvant could be used for human beings and that a substantial boost in a immune response will be achieved here.
The same general comments apply to the combination of 10 μg of GMDP with 100 μg of zinc in the form of zinc proline with 1.5 mg of proline and 20 μg CHAPS as used in experiment 13, and also for the similar formulation used for experiment 14 with the CHAPS substituted by DDA. Here it will be noted that at day 28 there is already a very significant increase over the antibody titer obtained with Freund's complete adjuvant and the values at 42 and 56 days are massively higher than the values obtained with Freund's adjuvant. Again formulations of this kind could be entertained for human use and the commercial value of such combinations and commercial products for use with animals is beyond dispute.
Experiment 15 corresponds closely to experiment 14 but uses 10 μg of MDP instead of 10 μg of GMDP. Although the results with MDP are not quite as good as with GMDP, they are still very respectable when compared with Freund's complete adjuvant and again do not result in the unwanted side effects or increased mortality rate associated with the use of Freund's complete adjuvant.
Experiments 16 and 17 involve the use of two other lipid substances in the same dose as was used for the CHAPS and DDA of experiments 13 and 14, i.e. 20 μg. It will be noted that the results obtained with 20 μg Hoe 4243 esterquat of experiment 16 and of cholesteryl stearate of experiment 17 also result in extremely high relative antibody titers after 42 and 56 days.
Experiment 18 resembles experiment 14 but involves three times the dose of GMDP which also results in a slightly higher value at 42 and a better value at day 56, however GMDP is relatively expensive and the benefit gained by adding GMDP is outweighed by the cost consideration. Thus 10 μg GMDP is still considered to be the ideal dose for a rabbit.
Experiments 19 and 20 use two further substances in the form of α-tocopherol (which is a lipid) and dextrane (a sugar) in place of the lipid substances used in experiments 12 to 14, α-tocopherol is clearly useful but not as efficient as any of lecithin, CHAPS or DDA. Dextrane is also feasible but does not produce much improvement over Freund's complete adjuvant, although it does not have undesired side effects and higher mortality rates associated with Freund's complete adjuvant.
In any event the experiments 12 and 19 clearly show the synertistic effect of the three-part adjuvant formulation of the present invention comprising a glycopeptide, an aminoacid complex of a divalent biological trace metal and a lipid substance, and, when compared with the relevant experiments of 1 to 11, show that the three-part formulation is substantially better than the results obtained using just one or two of the components.
Thus Table 1 clearly shows that two different glycopeptides (GMDP and MDP) in combination with a proline compound of a divalent metal and any one of at least six different lipid substances leads to a synergistic effect and a substantially enhanced immune response.
Experimental:
The following are the experimental conditions for determining the temporal evolution of the antibody titers with the various immunostimulants.
Animals:
Rabbits inbred b+Kap Immunological Institute of the Latvian Academy of Science Wilnius. One experiment uses four animals.
Antigen:
100 μg bovine serum albumin (BSA) per injection. Adjuvanted antigen solution: The solution to be injected is prepared by injecting 1 ml of antigen solution into the vial with the dry adjuvant containing 100 μg GMDP plus the synergists in proportion and dispersing the solid in the antigen solution. The resulting liquid is turbid from finely dispersed DDA.
Injection:
100 μl of the antigen+adjuvant solution are injected into the hind flank of the rabbit at one single site by subcutaneous route.
Serum Collection:
Heparinised plasma was collected by ear vein bleeding. Antibody determination: Anti BSA-IgG titers were measured using a microplate sandwich ELISA assay for antibody to BSA. 96 well flat bottom microtiter plates were coated with 100 μl BSA coating solution (4 μg/ml) in a humid chamber over night at 4° C. Plates were then washed with phosphate buffered saline (PBS) and blocked with 200 μl PBS-gelatine blocking solution for 1 hour at 37° C. followed by three washes with PBS. Dilutions from serum 1/10-1/100 000 were added to the washed plates in 100 μg aliquots. Plates were incubated at 37° C. for two hours. Plates were washed three times and 100 μl peroxide in citrate buffer pH 5) was added for 15 minutes at room temperature. 100 μl of 2,5M phosphoric acid stop solution was added and the light absorbance at 450 nm was read using a microplate reader. Titers were calculated from raw absorbance data within the linear range using a linear regression program present in the plate reading machine. The reciprocal dilution of serum which shows a colour of 0.75 was defined at the "titer".
EXAMPLE 2
As part of the efforts to find the most efficient immunisation routine, a number of immunisations were done with rabbits, mice and hens as test animals using BSA, DNP-BSA and human lambda light chain /HILC) as antigens in order to check the general adjuvant effect of GMDP and synergists. A more efficient immunisation routine was applied here, consisting in more frequent adjuvanted antigen injections (multiple boosting) that was possible because of the good biotolerance of the new adjuvants and which lead to significantly higher antibody yields.
TABLE 2______________________________________Relative Antibody Titer A.sub.rel 28 various Animals and Antigens Antigen A.sub.rel 28Animal BSA DNP-BSA Human LC Human IgG______________________________________Rabbit 10.8 7.6 8.9Hen 3.7 4.2 5.0 2.2Mouse 3.7 4.2 5.0Hamster 1.4Goat 0.3______________________________________
Relative Antibody titers are the titers obtained with adjuvants as described under experimental, divided by the antibody titers with Freund's adjuvant after 28 days with the same animal under the experimental conditions described below.
Table 2 thus shows the enhanced immune response achieved by the present invention is not restricted to just one antigen in the form of BSA but rather also applies to three further antigens, namely DNP-BSA, human λ light chain and human IgG.
These results thus make it clear that the method and formulation of the invention is applicable to a variaty of animal species and to a variety of antigens. Experience with immune response using other adjuvant formulations permits the clear conclusion that the results presented here are strongly indicative that the same immune response will be obtained with other antigens and using other lipids and other lipids in the adjuvant formulation. Moreover, the research we have conducted indicates that proline compounds in general can be used in the adjuvant formulation in addition to the zinc L-proline and L5 oxoproline.
Experimental conditions for the results of Table 2:
Rabbits:
Groups of three. BSA 100 μg, DNP-BSA 50 μg, HILC 20 μg. Adjuvant formulation 10 μg GMDP, 20 μg DDA, 100 μg Zn. Immunise/boost: day 0.7, 14, 21, bleed at day 28
Hens:
Group of five. BSA 50 μg, DNP-BSA 20 μg, HILC 10 μg. Adjuvant formulation 5 μg GMDP, 10 μg DDA, 50 μg Zn 0.7 mg proline. Immunise/boost: day 0, day 21. Pool eggs from day 26-30. Important: subcutaneous route is much superior to i/m route. The IgY contained in the yolk of the eggs was enriched for ELISA test by the method of J. Wallmann, C. Staak & E. Luge (1990) J.Vet. Med. B37, 317-20.
Mice:
Group of five. BSA 20 μg, DNP-BSA 10 μg, HILC 10 μg. Adjuvant formulation 1 μg GMDP, 4 μg DDA, 10 μg Zn 150 μg proline. Immunise/boost: day 0, day 14, bleed at day 28. Blood was collected by tail vein bleeding. Animals were anaesthetisised prior to blood collection using metofane.
Hamsters:
Group of five. Human IgG 100 μg,. Adjuvant formulation 2 μg GMDP, 4 μg DDA, 20 μg Zn 300 μg proline. Immunise/boost: day 0, 14, 28, bleed day.
Goats:
Group of two. 200 μg Human IgG. Adjuvant formulation 300 μg GMDP, 3 mg zinc 450 mg proline, 20 mg ESTERQUAT Hoe 3242. Immunise/boost: day 0, 14, 28, bleed day 35.
ELISA testing as described sub Example 1. The results listed in Table 2 show that the efficiency of the new adjuvant formulation is a phenomenon that apparently is not limited to one particular animal species and to one single antigen. A further indication of this fact is that the individual components of the claimed adjuvant formulation have been observed to function as immunostimulants in a great variety of antigens, animals and experimental conditions at correspondingly lower levels.
EXAMPLE 3
Preparation of Zinc-L-proline Stock Solution
Into a 500 ml beaker on a magnetic hot plate place magnetic stirrer, 2.07 g Zinc oxide DAB 6 and 25.36 g L-proline DAB 6 (1:9 molecular ratio) and 200 ml 65% ethanol. Heat to gentle boiling under stirring. After a few minutes the ZnO has dissolved. Allow the solution to cool, transfer into a 250 ml volumetric flask and fill to the mark with 65% ethanol. Filter into a bottle for storage. 150 μl of this stock solution contain 1 mg zinc and 16.1 mg L-proline.
EXAMPLE 4
Preparation of the zinc-L-proline complex. 5 ml of the Zn-L-proline stock solution is diluted with isopropanol and cooled to +4° C. Large crystals form over night which are collected and washed with isopropanol, recrystallised from 65% EtOH-isopropanol and dried. The material is evidently zinc-L-proline salt Cotton, F. A. & Hanson, H. P. (1959) J. Chem. Physics 28. 83-6! found; % C 42.23 H 5,76 N 9,40 Zn (as ZnO residue) 23.90. Calculated for Zn.Pro 2 ; C 10 H 16 N 2 O 2 Zn % C 45.94 H 6,17 N 10.71 Zn 24.94. The excess L-proline apparently serves to solubilise the material in ethanol.
EXAMPLE 5
Adjuvant Formulation, Standard Dose DDA
When preparing the zinc L-proline solution per Example 3, put 167 mg GMDP (produced by Peptech Ltd., Cirencester U.K. unter U.S. Pat. No. 4,395,399, USSR Priority Nov. 2nd 1977) and 333 mg DDA (dimethyldioctadecylammonium chloride, GenaminSC) produced by Farbwerke Hochst AG recristallized from acetone) into the volumetric flask before adding the zinc-proline solution.
150 μl of this stock solution contains 100 μg GMDP, 200μ DDA, 1 mg zinc and 16.1 mg L-proline. Before dispensing the solution into the individual vials it is passed through a 0.2 μm-Poretics polycarbonate membrane filter. A standard volume of this solution is 150 μl to give a solid deposit containing 100 μg GMDP. If only a few vials are required for experiments a desiccator with sulfuric acid will dry the contents within some hours. For production of larger numbers of vials a vacuum dryer with 5 mbar and 37° C. temperature is suitable. The residue is a white substance which readily dissolves in the antigen solution to a slightly turbid dispersion.
EXAMPLE 6
Adjuvant formulation with very lipophilic compound. Into the vial is first pipetted 200 μl water containing 4 mg of the water soluble zinc L-proline salt (ZnPro 2 ) and lyophilized in place. After this, a solution containing 100 μg GMDP, 15 μg L-5 oxoproline (pyroglutamic acid) in 200 μl isopropanol+20 μg cholesteryl stearate in 100 μl ethyl acetate, total 300 μl of a clear solution is pipetted into the same vial which is then placed in the vacuum dryer at 30° C. and evacuated to 5 mbar, maintained for 3 hours. The residue readily dissolves in 1 ml water to slightly turbid solution, no particles can be seen in the microscope at 1:1000.
EXAMPLE 7
Dosage of ADJUVANT
Convenient portions of solid ADJUVANT for practical use in immunisations are 100 μg GMDP or 10 μg GMDP and corresponding synergists in a serum vial suitable for 10 immunisations of rabbits or mice respectively, obtained by pipetting 100 μl of ADJUVANT solution prepared according to example 6 into vials and drying them over sulfuric acid, experimental lots in a desiccator, production lots in a specially designed drying chamber.
EXAMPLE 8
Immunisation experiments with ADJUVANT
The purpose of these experiments was to establish faster immunisation routes by multiple boosting and to check the biotolerance of the ADJUVANT (10 μg GMDP, 20 μg DDA, 100 μg zinc+1,4 mg L-proline) with rabbits. The results are summarised in Table 3. The numerical data represent antibody titers expressed in reciprocal dilutions as described in Example 1.
No animal damage could be observed even with severely challenging daily doses of ADJUVANT. (cf. expt. 47). Antibody expression with very feeble antigen levels could be forced by daily immunisation with antigen and ADJUVANT (expt. 43,44). Adjuvant or GMDP alone injected separately from antigen is not effective (expt. 45-49).
TABLE 3__________________________________________________________________________Efficiency and Tolerance TestsExpt. Events on given day, for explanation see footnotesNr. 0 7 14 21 28 35 42 Purpose of Experiment Comments__________________________________________________________________________33 I I Standard ADJUVANT check run -- 4385 26800 d70: 32000, d84:1253241 I I I Biweekly ADJUVANT check -- 2440 8324 9273 basis for all tests Table 342 I I I I I Weekly boosting 100 μg BSA -- 000 4376 20996 19460 8976 body temperature weight43 i i i i i Weekly boosting 25 μg BSA -- 000 140 228 88 observe body temp DTH44 iiiiiii iiiiiii iiiiiii iiiiii Hyperboosting 25 μg BSA daily + -- 000 6379 18944 27136 5440 ADJUVANT body temperature ok45 I aaaaaa aaaaaa I aaaaaa aaaaaa I Imitation of an ADJUVANT depot -- 1104 8512 8520 compare with #4146 I gggggg gggggg I gggggg gggggg I Imitation of pure GMDP depot-- 28 68 156 without synergists: inhibition47 I AAAAA AAAAA I AAAAA AAAAA I Tolerance test with 10-fold dose -- 420 2244 of ADJUVANT animals ok48 BSA BSA BSA Check the effect of ADJUVANT -a + 8 a - 8 a - 8 injection 8 hours before the injection -- 592 184 288 of antigen 100 μg BSA49 BSA BSA BSA Check the effect of ADJUVANT -a + 1 a + 1 a + 1 injection 1 hour after the injection -- 34 88 324 of antigen 100 μg BSA55 FCA FCA FCA Check standard routine with -- 1028 1796 8964 Freund's adjuvant__________________________________________________________________________ Explanation of symbols for events in Table 3: A ADJUVANT reconstituted in water to 10 fold concentration (100 μg GMDP + synergists a ADJUVANT reconstituted in water standard concentration 100 μl injection I Immunize with ADJUVANT and 100 μg BSA i Immunize with ADJUVANT and 25 μg BSA a - 8 Inject Adjuvant 8 hours prior to BSA of BSA a + 1 inject ADJUVANT 100 μl 1 hour after injection FCA Immunize with 100 μg BSA + 100 μl Freund's complete adjuvant | The improved method uses N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP) or N-acetylglucosaminyl-N-acetyl-muramyl-L-alanyl-D-isoglutamine (GMDP) in low dose ranges in a combination with zinc-L-proline complex and with immunostimulating lipid in doses which synergistically potentiate the effect of each single component whereby the zinc-L-proline complex contains an excess of L-proline or 5-oxo-L-proline which serves as a solubiliser and dispersing agent for the lipid component. | 0 |
BACKGROUND TO THE INVENTION
1. Field of the Invention
The present invention relates to a positioning servomechanism. More particularly, the present invention relates to a positioning servomechanism operating between endstops, where a high speed collision with the endstops would damage the servomechanism itself or the equipment being positioned. Still more particularly, the present invention relates to the style of servomechanism which is used to position a radially mobile transducer over data storage tracks in a disc file. In greatest particularity, the present invention relates to an externally controlled servomechanism in a disc file where provision is made to avoid damage in the event of the external controller, or the servomechanism itself, developing a fault condition.
2. The Prior Art
The use of servomechanisms to position radially mobile read/write heads over data storage tracks, on discs in disc files is a well known art. The head is moved between endstops representing the least and greatest radii of its range. The read/write head is generally fragile, and is mounted on flimsy flexures. In the event of the servomechanism causing the head to collide violently with either of its endstop positions, the resultant short stopping distance, with attendantly high deceleration forces, may cause damage to the head, the head flexures, or the servomechanism actuator itself. In addition, there is usually provided a head unloading ramp, up which the head is parked when removed from the surface of the disc. Collision of the head with this ramp at high speed places the head in extreme risk of sustaining damage.
The trend towards higher performance disc files has resulted in the abandoning of relatively safe but slow stepping motor head positioning servomechanisms in favour of faster magnetic linear or rotary actuators, where a force proportional to current positions the head under the control of positional feedback information and externally applied demand and control signals. Should any fault develop in the servomechanism or the equipment providing demand and control signals, then there is a risk that the actuator will be accelerated uncontrolably towards one or other of its endstops. The relatively high cost of heads renders an original fault, most probably the result of a low cost failure, an unexpectedly costly fault to repair by necessitating the replacement of heads.
It is also the trend that microprocessors are used to command and control head positioning servomechanisms. Should malfunction or external influence disrupt the operation of the microprocessor, it is quite capable of entering a series of random, uncontrolled states in which commands may be sent to the servomechanism which, if obeyed, would result in damage and destruction.
It is therefore desirable that a method and apparatus be provided whereby the drive signals resulting from a fault condition in either the servomechanism itself or the external controller thereto may be overridden in the event of their being likely to cause damage, and the action of the servomechanism rendered harmless.
SUMMARY OF THE INVENTION
1. Object of the Invention
It is an object of the present invention to provide a servomechanism with protecting apparatus whereby the output of the servomechanism drive to the actuator is monitored for saturation, and when that saturation is detected as lasting for more than a predetermined period, drive is inhibited to the actuator.
2. Description of the Preferred Embodiment
In a preferred embodiment of the present invention, a power amplifier, part of a positioning servomechanism, has its outputs monitored for positive and negative saturation levels, and if either of these levels persists for longer than a predetermined period, the power amplifier is disabled, and kept disabled until externally re-enabled.
The operation of the present invention, together with further aims and objectives thereon, will be further understood by consideration of the following description in conjunction with the appended drawing.
DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the system of the preferred embodiment of the present invention.
FIG. 2 shows the coil acutated by the servo-mechanism.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
An inhibitable power amplifier 10, being part of a positioning servomechanism is provided with an inhibiting input on its inhibiting connector 28 which, when logically true, allows the amplifier 10 to function normally, but when logically false, disables and shuts down the amplifier 10 bringing and holding its output to zero.
The amplifier 10 delivers its output, within its function as part of a positioning servomechanism, to the coil of the servomechanism actuator 12. The servomechanism, shown in FIG. 2, also includes a positional feedback transducer, and compensation and control elements, all well known in the art and constituting no part of the instant invention.
The output of the power amplifier 10 is also delivered as an input to a positive saturation comparator 14 and a negative saturation comparator 16. The positive saturation comparator 14 is provided, on its inverting input 18 with a positive reference voltage, just a little less in magnitude than the output voltage of the power amplifier 10 when it is saturated in the positive direction. The output of the positive saturation comparator 14 is logically false if the output of the power amplifier 10 is less positive than the positive reference voltage, and logically true, indicatively of positive saturation, if the output of the power amplifier 10 is more positive than the positive reference voltage.
In a precisely similar manner, the output of the power amplifier 10 is monitored for negative saturation by the negative saturation comparator 16. This comparator 16 is provided, on its non-invertin input 20, with a negative reference voltage which is a little less in magnitude than the output of the power amplifier 10 when it is saturated in the negative direction. The negative saturation comparator 16 provides an output, indicatively of negative saturation of the power amplifier 10, which is logically true if and only if the output of the power amplifier 10 is more negative than the negative reference voltage.
The outputs of the positive and negative saturation comparators 14 & 16 are coupled as simultaneous inputs to an OR gate 22, whose output is true if either of its inputs is logically true. The output of the OR gate 22 being logically true is thus indicative of the output of the power amplifier 10 being in either positive or negative saturation.
The output of the OR gate 22 is coupled simultaneously as the triggering input and the resetting input to a positive edge triggered monostable timer 24, which is reset by a logically false level being presented at its resetting input 23. Whenever the output of the OR gate 22 is logically false, the monostable timer 24 is pre-emptively reset, so that its inverted output 25 assumes a true level. Whenever the output of the OR gate is logically true, the monostable timer 24 ceases to be reset, and is triggered into its timeout operation by the rising edge of the logically false to logically true transition of the output of the OR gate 22, presented at the triggering input 21. Whenever the timing cycle is in progress, the output 25 of the monostable 24 assumes a logically false condition. At the end of a timing period, the output 25 of the monostable 24 reverts to a logically true condition. A timing cycle is terminated by the act of resetting the monostable 24.
The output 25 of the monostable 24 is provided as the clocking input to a positive edge triggered, D-type flipflop 26 the output of the OR gate 22 is also provided as the data input to the D-type flipflop 26. Whenever a logically false to logically true transition occurs on its clocking input, the D-type flipflop 26 provides and holds, as its output 27 the logical inverse of the signal provided at its data input at the instant of the clocking transition.
The output 27 of the D-type 26 is provided as the resetting input to a set/reset flipflop 32. An externally provided setting input connector 30 is coupled to the setting input of the set/reset flipflop 32. The output of the set/reset flipflop 32 assumes and retains a logically false value whenever its resetting input is taken logically false, and assumes and retains a logically true value whenever its setting input is taken logically false.
The output of the set/reset flipflop 32 is coupled to the inhibiting input of the power amplifier 10.
In the operation of the preferred embodiment, the output of the set/reset flipflop 32 is firstly made logically true by the application of a resetting signal on the external connector 30 in the logically false condition. This signal is thereafter returned to the logically true condition, the output of the set/reset flipflop 32 remaining in a logically true condition, thus enabling the operation of the power amplifier 10. At any time thereafter, should the output of the power amplifier 10 become more positive or negative than either of its limits, these being the positive and negative reference voltages, the monostable 24 is triggered into its timeout.
The output 25 of the monostable 24, in triggering, goes from logically true to logically false. Should the output of the OR gate 22 return to a false condition before the end of the timeout, the output 25 of the monostable 24 is instantly reset, going from logically false to logically true. The true to false transition triggers the D-type flipflop 26 which presents, as its output, the inverse of the output of the OR gate 22. Since the output of the OR gate 22 is logically false, having just reset the monostable 24, the clocked output of the D-type flipflop 26 is logically true. The true level at the output 27 of the D-type flipflop 26 does not set the set/reset flipflop 32, and the action of the power amplifier is thus maintained if the power amplifier 10 comes out of saturation before the end of the timeout period.
The output 25 of the monostable 24 also goes automatically from logically false to logically true at the end of the timeout cycle. If the amplifier 10 remains in saturation for more than the timeout period, the output of the OR gate 22 is still logically true at the instant the output of the monostable changes. The D-type flipflop 26 is triggered by the change, and in clocking through the inverse of the output of the OR gate 22, provides a logically false output. The logically false output of the D-type flipflop 26 causes the set/reset flipflop 32 to be reset, and so provide and retain a logically false output.
The logically false output of the set/reset flipflop 32 disables the power amplifier 10 beginning and holding the power amplifier 10 output to zero, and thus removing all drive to the actuator 12. The power amplifier 10 remains thus shutdown until an external resetting signal of a logically false value is applied to the setting input of the set/reset flipflop 32.
The value of the timeout of the monostable 24 is selected to be longer than any period of saturation anticipated in the normal operation of the servomechanism, and is thus related to the unity gain frequency and damping factor of the servomechanism.
FIG. 2 shows the load 12 of FIG. 1. The load 12 comprises a voicecoil actuator 34 in receipt of energy from the power amplifier 10 of FIG. 1. The actuator 34 comprises a moving coil assembly 36 in a magnet assembly 38. When current flows in the coil 36 it experiences a displacement force proportional in magnitude and direction to the size and sense of the current flow.
An arm 40 couples the coil 36 to a magnetic data recording head 42 to position the head 42 at selectable radii on a data storage disc 44 rotatable as indicated by the arrow 46 so that the head 42 can be used to record or recover useful data signals on the disc 44 at any selectable one of a plurality of concentric data-storage tracks.
A position transducer 48 is coupled via a mechanical coupling 50 to the arm 40 to provide an output indicative of the radius of the head 42 on the disc 44. In the operation of the overall servomechanism and in a manner well-known in the art of servomechanism design the output of the transducer 48 is subtracted from the externally provided demand signal and the result of that subtraction coupled as the input to the power amplifier 10 to control the radius of the head 42 in sympathy with the external demand signal. The transducer can be of any kind. As an example of use, the invention can be employed in the Burroughs B-9480 disc drive where the transducer 48 is an optical grating detente transducer. The described use of the invention in positioning a magnetic disc drive's head 42 over the disc 44 is illustrative of and not restrictive to the invention, and is provided for the better understanding thereof.
It is to be appreciated that many variant embodiments exist. In particular the comparators 14 & 16 are replaceable by numerous other types of devices, and the voltage levels for comparison are selectable as being other than saturation levels. The externally provided setting signal may originate from a manual switch or some monitoring device. The logically false condition of the output of the set/reset flipflop 32 may be used to activate indication of a shutdown. The set/reset flipflop 32 may be omitted, and the output 27 of the D-type flipflop 26 taken directly to the inhibiting input of the amplifier. The D-type flipflop may be replaced by a sequential logic network. | A positioning servomechanism, which is liable to damage, or positions other equipment which is liable to damage if extremeties in its positioning locus are encountered at speed, is protected against uncontrolled and catastrophic acceleration towards these extremeties by the provision of apparatus which shuts off power to the servomechanism in the event of its drive output exceeding a predetermined limit, indicative of saturation, for more than a predetermined time period, power being restored by the application of an external signal. | 6 |
The present application is a divisional of U.S. patent application Ser. No. 09/876,715, filed Jun. 6, 2001 now U.S. Pat. No. 6,882,766.
FIELD OF THE INVENTION
The present invention relates to the field of optical switches for fiberoptic networks. More particularly, the present invention relates to multistage optical switch architectures with input/output switch modules and redundant switches, and to methods for upgrading switch fabrics.
BACKGROUND
The use of fiberoptic networks is increasing due to the high bandwidth provided by such networks for transporting data, voice, and video traffic. Large switches would help to accommodate the switching needs of many of the larger fiberoptic networks, especially the high-capacity fiber backbones.
One disadvantage of certain prior art optical switches is that although optical signals can propagate almost losslessly while confined in optical fiber, the size of certain prior art optical switches is typically limited by diffraction of optical beams as they propagate through free space inside the switches. Moreover, large optical switching devices can be difficult to construct given the large number of optical cables and beams and complex associated electrical connection issues. In short, large optical switches can be costly and unwieldy.
Various types of non-optical electrical switch fabrics have been used in the prior art for telephony and network applications. One of the simplest structures has been the crossbar switch. One problem with the crossbar switch is the quadratic growth of crosspoints as the switch gets larger, which can result in far more cross-points than necessary to create all possible permutation connections. For a permutation switch, connections between input and output ports are point to point—neither one-to-many nor many-to-one connections are permitted.
To avoid the problem of excess crosspoints found in a single large switch, techniques have been developed for cascading small electrical switches into a multistage switch fabric in order to make large electrical permutation switches.
Permutation switches can be classified in terms of their blocking characteristics. On a switch, requests for connection establishment and termination can occur at random points in time. A permutation switch is rearrangeable or rearrangeably nonblocking if there exists a set of paths through the switch fabric that realizes each of any possible connection states. The rearrangeable aspect means that it may be necessary to rearrange currently active connections to support a request for a new connection between a pair of idle input and output ports. Problems with rearrangeable nonblocking switches include the fact that the required device settings to route connections through the switch are not determined easily and that connections in progress may have to be interrupted momentarily while rerouting takes place to handle the new connections.
Wide-sense nonblocking networks or switches are those that can realize any connection pattern without rearranging active connections provided that the correct rule is used for routing each new connection through the switch fabric.
Strict-sense nonblocking networks or switches require no rearrangement of active connections and no complex routing algorithms. New connection requests are allowed to use any free path in the switch. Strict-sense nonblocking switching fabrics (also referred to as strictly nonblocking switches) typically require more hardware than wide-sense nonblocking and rearrangable switching fabrics, but avoid connection disruption and provide simplicity of routing.
One type of cascaded permutation switch topology is a Clos switch fabric, also referred to as a Clos network, a Clos switch matrix, or a Clos switch. Various Clos switch configurations can constructed. For example, some Clos switch fabrics can be strict-sense nonblocking, other Clos switch fabrics can be wide-sense nonblocking, and others can be blocking. The blocking configurations are less useful, given that some combinations of input and output connections cannot be made.
FIG. 1 shows a three-stage Clos switch fabric that is strict-sense nonblocking, meaning that any input can be routed to any output at any time. The Clos switch fabric of FIG. 1 has N inputs, N outputs, K input stage switches, 2p−1 center stage switches, and K output stage switches. Each input stage switch has p inputs and 2p−1 outputs. Each center stage switch has K inputs and K outputs. Each output stage switch has 2p−1 inputs and p outputs.
One disadvantage of the strict-sense nonblocking Clos switch fabric of FIG. 1 is the lack of redundancy in switch connections. Redundancy is a desirable characteristic in a switch fabric because redundancy helps to permit rerouting in the event of a failure, the use of extra paths for test purposes during switch operation, and switch reconfiguration during switch operation.
SUMMARY OF THE INVENTION
An optical switch fabric is described that has an input stage, an output stage, and a center stage coupled in a cascaded manner. The center stage includes (1) a minimum number of center switches greater than one that cause the optical switch fabric to be strict-sense nonblocking and (2) at least one additional center switch to provide redundancy for the optical switch fabric.
A module is described that includes an optical input switch of an input stage of an optical switch fabric, an optical output switch of an output stage of the optical switch fabric, and an interior cavity. The input and output stages are coupled to a center stage of the optical switch fabric. The interior cavity contains free space beams from both the optical input switch and the optical output switch.
A method is described for reconfiguring an optical switch without interrupting working optical signals.
Other features and advantages of the present invention will be apparent from the accompanying drawings and from the detailed description that follows below.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements and in which:
FIG. 1 shows a prior art multistage switching fabric with a Clos architecture.
FIG. 2 shows a multistage Clos switching fabric with external 1×2 switches and 2×1 switches for redundancy.
FIG. 3 shows a Clos switch fabric with redundancy input and output stage switches.
FIG. 4 illustrates a redundant Clos switch fabric that includes an additional center stage switch.
FIG. 5 shows an 8,000-port optical redundant Clos switch fabric that has 8-port input stage switches and 8-port output stage switches.
FIG. 6 illustrates the architecture of an optical Clos input/output module for a redundant Clos optical switch fabric.
FIG. 7 shows a redundant Clos switch fabric with relatively small center stage switches.
FIG. 8 shows a redundant Clos switch fabric with partially populated center switches.
FIG. 9 illustrates a switch fabric that uses 125 Clos input/output modules and two 1,000-port switches.
FIG. 10 is a simplified schematic of the switch fabric of FIG. 9 with the 8×16 input stage switches shown as a single box and the 16×8 output stage switches shown as a single box.
FIG. 11 shows a partial upgrade from a switch fabric that uses Clos input/output modules and two 1,000-port center switches to a redundant Clos switch fabric.
FIG. 12 shows a completed upgrade to a redundant Clos 1,000 port switch fabric.
FIG. 13 shows a redundant Clos 2,000-port switch fabric configured by the addition of fiber interconnections.
FIG. 14 shows a redundant Clos 4,000-port switch fabric configured by repositioning fiber cables.
FIG. 15 shows a redundant Clos 8,000-port switch fabric.
FIG. 16 shows a redundant 16,000 port Clos switch fabric configured by upgrading center stage switches from 1,000-ports to 2,000-ports.
DETAILED DESCRIPTION
A high availability optical switch fabric or matrix is described that uses a Clos multistage architecture.
As will be described in more detail below, for one embodiment an additional center stage switch is added to a strict-sense nonblocking optical Clos switch fabric to provide redundancy. An intended advantage of the embodiment is to provide a large capacity optical switch that is easier to construct given that is comprised of a number of smaller optical switches. Another intended advantage is the capability of providing both working and protection (i.e., test) connections and yet have the working connections be strict-sense nonblocking. A further intended advantage includes an enhanced ability to reroute connections during failure. Another intended advantage of the redundant Clos switch fabric is that it is amendable to switch fabric reconfiguration and upgrades while live traffic is being carried, thereby helping to minimize service disruptions.
An embodiment is described wherein input stage switches and output stage switches are combined to form Clos input/output modules (“CIO modules”). An intended advantage of this embodiment is to minimize switch granularity as compared with separate input stage switch modules and output stage switch modules. Other intended advantages include cost minimization and modularity to help to facilitate switch fabric upgrades.
Methods are also described for upgrading switch fabrics into large redundant Clos switch fabrics while those switch fabrics carry live traffic. Intended advantages of the methods include minimizing service disruption, providing various flexible upgrade paths, and providing the ability to reuse at least some existing equipment, thereby helping to minimize costs.
One way to add redundancy to a strict-sense nonblocking Clos switch fabric is shown in FIG. 2 . In FIG. 2 , optical protection switches (1×2 and 2×1) are placed at the respective input 2 and output 3 optical switch stages and an identical redundant three-stage optical Clos switch 12 is added to the original three-stage optical Clos switch 8 .
FIG. 3 shows a simplified version of the redundant Clos network of FIG. 2 . In the redundant Clos optical switch fabric 10 of FIG. 3 , each 1×2 protection switch and each of two corresponding p×(2p−1) switches of the switch fabric of FIG. 2 are combined into one p×(4p−2) switch. The output stage (2p−1)×p switches and the 2×1 protection switches are similarly combined into (4p−2)×p switches. This allows the optical switch fabric 10 of FIG. 3 to eliminate the protection switches (1×2 and 2×1) of FIG. 2 , even though the switch fabric of FIG. 3 maintains a redundancy similar to that of the switch fabric of FIG. 2 . The switch configurations of FIGS. 2 and 3 achieve redundancy through the use of a large number of components and, accordingly, there is an increase in complexity.
FIG. 4 illustrates an optical Clos switch fabric 20 that is strict sense nonblocking and is fully redundant. Redundancy is achieved in the switch fabric 20 by the inclusion of an additional center stage switch 46 . Switch fabric 20 is also referred to as switch matrix 20 , network 20 , multilevel switch 20 , multistage switch 20 , or simply switch 20 .
The Clos switch fabric 20 has an input stage 30 , a center stage 40 , and an output stage 50 . The input stage 30 is coupled to the center stage 40 via fiber optic interconnect lines 38 . The center stage 40 is coupled to the output stage 50 via fiber optic interconnect lines 48 .
The input stage 30 comprises K optical input switches 36 . K is an integer. Each of the input switches 36 has P inputs and 2p outputs. P is an integer. There are N inputs 34 to the input stage 30 . N is an integer. The inputs 34 are divided evenly between the switches 36 so each switch has N divided by K number of inputs. Therefore, P equals N divided by K.
The 2P outputs of each input stage switch 36 are coupled to the center stage optical switches 46 . Each output of each of the input stage switches 36 is coupled to one of the center stage switches 46 such that each switch 36 is coupled to each of the center stage switches 46 .
For one embodiment, the number of center stage switches 46 is 2P, which equals the number of outputs of each input stage switch 36 . Each of the center stage switches 46 has K inputs and K outputs. K equals the number of input stage switches 36 .
The K outputs of center switches 46 are coupled to output optical switches 56 of output stage 50 . Each of the output switches 56 has 2P inputs and P outputs. There are K switches 56 in output stage 50 . There are N outputs 54 of output stage 50 . Each of the outputs K of each center stage switch 46 is coupled to one of the switches 56 of output stage 50 .
Redundancy is obtained in switch fabric 20 by adding an additional center stage switch 46 beyond the number of center stages switches required for the switch fabric to be strict-sense nonblocking. Thus, switch fabric 20 has 2P center stage switches 46 . This differs from the prior art switch fabric shown in FIG. 1 , which only has 2P−1 center stage switches. For the switch fabric 20 shown in FIG. 4 , each of the input stage switches 36 has an extra output as compared to the input stage switches of the prior art switch fabric shown in FIG. 1 . In addition, each of the output stage switches 56 shown in FIG. 4 has an additional input as compared to the output stage switches of the prior art switch fabric shown in FIG. 1 .
The switch fabric 20 shown in FIG. 4 is more reliable than the prior art switch shown in FIG. 1 because the switch fabric 20 is fully redundant. Moreover, switch fabric 20 has fewer center stage switches and fewer fiber interconnects between the center stage switches and the input and output switches than the switches shown in FIGS. 2 and 3 and thus is more efficient. In particular, switch fabric 20 has 2P center stage switches, which contrasts with the 4P−2 center stage switches of the switch fabrics of FIGS. 2 and 3 . In addition, each input stage switch of the switch fabric shown in FIG. 3 has 4P−2 outputs and each output stage switch of that prior art switch fabric has 4P−2 inputs. In contrast, each of the input stage switches 36 of FIG. 4 has 2P outputs and each of the output stage switches 56 has 2P inputs.
The switch fabric 20 of FIG. 4 has one additional center stage switch 46 added for redundancy. For alternative embodiments, however, additional center stage switches 46 could be added for more redundancy. There need only be P center switches 46 to make switch fabric 20 rearrangeably nonblocking.
The center stage 40 of Clos switch fabric 20 of FIG. 4 has the capability of establishing two times the number of total possible connections in order for the switch fabric 20 to still be strict-sense nonblocking. Nevertheless, if switch fabric 20 is configured to be only rearrangeably nonblocking, then the center stage 40 need only have capacity for the total possible connections, rather than two times the number of total possible connections.
A protection path can be set up for every working path. If the working connections through the Clos switch fabric 20 must be strict-sense nonblocking, but the protection connections are allowed to be rearrangeably nonblocking, then it is possible to only require two times the number of total possible working connections (strictly K equals 2 times N) and yet have the capability of providing both working and protection connections. The establishment of any working connection must be able to preempt any protection connection. The establishment of any protection connection may require rearrangement of all of the other protection connections.
FIG. 5 shows an optical redundant Clos switch fabric 60 that has an input stage 70 , a center stage 80 , and an output stage 90 . The switch fabric 60 has 8,000 input ports 74 and 8,000 output ports 498 . The input stage 70 includes 1,000 optical input stage switches 76 . The center stage 80 includes 16 optical center stage switches 86 . The output stage 90 includes 1,000 optical output stage switches 96 .
Each input stage switch 76 has eight inputs for working signals. In addition, each input stage switch 76 has two inputs 71 for the outputs of test source 73 . Thus, each of the input stage switches 76 has ten inputs—i.e., eight working inputs IN 1 - 1 through IN 1 - 8 . for example, and 2 test inputs 71 . Lasers 73 provide the test light for the test signals. The test signals can be used for setting up protection paths.
The outputs of the test sources 73 can be routed to unused paths of the Clos switch fabric 60 to verify operation of all of the optical paths and to preconfigure the redundant center switch of center stage 80 with all the settings needed to replace any of the other center switches 86 should one of them fail. The test sources 73 may also be used to set up protection paths through unused ports in working switches.
Detectors 95 , each of which contains two detectors, are coupled to each of the output switches 96 in order to allow monitoring of the test signals through the unused Clos switch paths.
The optical Clos switch fabric 60 of FIG. 5 differs from the prior art. One prior art Clos electrical switch fabric would have input switches with 15 outputs, 15 center switches with 1,000 inputs and 1,000 outputs, and output stages with 15 inputs. In contrast, Clos optical switch fabric 60 of FIG. 5 has redundancy by the addition of another switch output to each input stage switch 76 , by the addition of another center stage switch 86 , and by the addition of another input to each output stage switch 96 .
Each of the center stage switches 86 of switch fabric 60 includes an internal optical tap 87 that allows substantially noninvasive real-time monitoring of any of the optical signals. The internal optical taps 87 in center stage switches 86 have the ability to provide high speed samples of the optical signals passing through switches 86 .
The input stage 70 of input switch fabric 60 includes detectors 72 for monitoring optical signals provided as inputs to switch fabric 60 . The input stage 70 also includes detectors 74 for monitoring optical signals from the outputs of input stage switches 76 . Output stage 90 of switch fabric 60 includes detectors 92 for monitoring optical signals that are sent as inputs to output stage switches 96 . Output stage 90 also includes detectors 94 for monitoring the output optical signals from output stage switches 96 .
For alternative embodiments of the invention, switch fabric 60 of FIG. 5 could be larger or smaller, but still meet the relationships among K, P, and N of Clos switch fabric 20 of FIG. 4 . For example, binary sequences can be used, such as K=1,024, P=8, and N=8,192. Alternatively, larger and smaller numbers can be used for K, P, and N.
For switch fabric 60 shown in FIG. 5 , the input stage switches 76 and the output stage switches 96 are grouped together to form Clos input/output (“CIO”) modules, which minimizes the switch granularity compared to having separate modules for input stage switches and separate modules for output stage switches. The functionality of the 10×16 optical input switches and the 16×10 optical output switches can be combined into one 26×26 optical switch
FIG. 6 illustrates Clos input/output module 110 , which is a 26×26 optical port switch that combines the functionality one of the 10×16 optical input stage switches 76 and one of the 16×10 optical output stage switches 96 of the switch fabric 60 of FIG. 5 .
Clos I/O module 110 includes a housing 119 that encloses an array 139 of microelectromechanical (“MEMs”) mirrors that includes an input beam mirror array 145 and an output beam mirror array 147 . For one embodiment, the MEMs array 139 includes 52 working mirrors for the 26 input optical beams and the 26 output optical beams. For an alternative embodiment, the MEMS array 139 includes 64 mirrors, which includes 12 mirrors for redundancy. Also enclosed within housing 119 is a fixed mirror 137 . Light beams 141 within housing 119 are reflected by input mirror array 145 , then reflected by fixed mirror 137 then reflected by output mirror array 147 to form output optical beams 143 .
Collimator array 131 holds the 26 input fiber lines and the 26 output fiber lines within housing 119 . For an alternative embodiment, collimator array 131 also holds 12 fiber lines for redundancy, for a total of 64 fiber lines. Monolithic lens array 132 focuses or collimates the optical outputs of the fiber lines of collimator array 131 into beams 141 . Lens array 132 also receives beams 143 and focuses them into the fiber lines that are carrying optical signals out of Clos I/O module 110 .
Tap 135 is also enclosed within housing 119 . Tap 135 permits substantially noninvasive optical power monitoring of optical beams 141 . Tap 135 sends optical signals to 26 photodetectors 133 within housing 119 for optical input signal detection and monitoring.
Clos input/output module 110 is a 26×26 port optical switch, so there are twenty-six inputs and twenty-six outputs. The eight Clos module inputs 114 are the same as the inputs to an individual input stage switch 76 shown in FIG. 5 , and thus are part of the inputs 74 to switch matrix 60 .
Inputs 128 to Clos input/output module 110 are 16 outputs from one of the 1,000×1,000 port center stage switches 86 shown in FIG. 5 . Thus, the optical signals on lines 128 are part of the signals carried by fiber lines 88 shown in FIG. 5 .
Inputs 111 to the Clos I/O module 110 of FIG. 6 are two optical fibers for two test lasers 113 . Test lasers 113 send optical test signals through inactive optical channels within Clos input/output module 110 .
Two corresponding optical output detectors 125 are provided on the output side of Clos input/output module 110 . Switch outputs not used for working signals send optical signals to the detectors 125 over two fiber lines 121 to allow detectors 125 to monitor inactive optical channels of Clos input/output module 110 . These detectors 125 correspond to detectors 95 of FIG. 5 .
Outputs 134 comprise eight optical Clos outputs from Clos input/output module 110 . Outputs 134 correspond to the outputs of one of the output stage switches 96 shown in FIG. 5 and are part of the outputs 498 from switch fabric 60 .
Further outputs from Clos input/output module 110 of FIG. 6 are the optical signals of fiber lines 118 , which are 16 signals to be sent to the center stage switches 86 shown in FIG. 5 . The sixteen signals on fiber lines 118 are part of the signals carried on connections 78 shown on FIG. 5 .
Clos input/output module 110 also includes twenty-four optical detectors 124 for monitoring the output optical signals from Clos input/output module 110 . Optical fiber power splitters 146 send optical signals to detectors 124 . Detectors 124 comprise a combination of a detector 74 and a detector 94 of FIG. 5 .
Thus, eight optical inputs 114 are switched among sixteen optical outputs 118 , which in turn go to the center switches 86 . Sixteen optical inputs 128 to Clos I/O module 110 coming from center switches 86 are switched among optical outputs 134 .
For alternative embodiments, more than twenty-six input and output ports would be fabricated for the Clos input/output optics module 110 to allow for production yield. For the alternative embodiments, other parts of the module 110 would be larger, such as the mirror array. For other alternative embodiments, the Clos I/O module 110 could be smaller, with fewer than 26 respective input and output ports.
For an alternative embodiment of the invention, the twenty-four photo detectors 124 sampling the output signals and the two photo detectors 125 used to monitor inactive channels may be placed inside the housing 119 of the optics module by routing the coupled output fibers 144 back into the collimator array 131 .
The cost of a large capacity optical switch with a Clos architecture like the switch fabric 60 of FIG. 5 can be dominated by a large number of small switches, which in this case are the 1,000 Clos input/output modules needed for an 8,000 port Clos switch, assuming the input and output stage switches 76 and 96 are combined into Clos input/output modules 110 . The total cost of the sixteen center stage switches 86 is lower than the total cost of the 1,000 Clos input/output modules 110 formed by switches 76 and 96 , even though the cost per switch is higher for the center stage switches 86 . The reduced cost is due to the fact that there are only sixteen center stage switches 86 versus 1,000 Clos I/O modules 110 .
For one embodiment of the invention, customers would be able to purchase expandable switch fabrics, where initially a small number of ports are purchased, but additional ports could be added as required.
One approach to an upgrade path for a switch fabric is to initially install the full set of center stage switches and install the Clos input/output modules (that form the input and output switch stages) as needed. For example, the 8,000 port switch fabric 60 shown in FIG. 5 initially could be used as a 2,000 port switch fabric by installing one fourth of the Clos input/output modules 110 that combine input switches 76 and output switches 96 . Such a 2,000 port switch would retain all sixteen center stage switches 86 . For this approach, however, the cost of the center stage switches 86 becomes a larger fraction of the initial cost of the switch fabric 60 because there are fewer Clos input/output modules 110 than with having 1,000 Clos input/output modules 110 . For alternative embodiments, this approach could be used for smaller or larger switch fabrics.
For yet other alternative embodiments, a reverse approach can be used to downgrade capacity of a switch fabric. Clos input/output modules could be removed to lower switch capacity in a manner opposite to the upgrade approach.
Another way to reduce the initial cost of installing a portion of a large capacity optical switch is to initially install smaller center stage switches, which is shown by the switch fabric 200 in FIG. 7 . Switch fabric 200 is a Clos multistage switch fabric containing input stage 210 , center stage 220 , and output stage 230 . Instead of being configured as an 8,000 port switch fabric such as switch fabric 60 shown in FIG. 5 , the switch fabric 200 is instead initially configured as a 2,000 port Clos switch fabric with one fourth of the Clos input/output modules as switch fabric 60 . For switch fabric 200 , the total number of inputs 214 is 2,000 and the total number of outputs 234 is 2,000. The switch fabric 200 of FIG. 7 has 16 center stage switches 26 that need only 250 input ports and 250 output ports. Therefore, each center stage switch 226 is a 250 by 250 port switch. Input stage 210 has 250 input stage switches 216 and output stage 230 includes 250 output stage switches 236 .
For the sake of simplicity, the test and monitoring functions are not shown in the switch fabric 200 of FIG. 7 . Each of the input stage switches 216 has eight inputs and sixteen outputs. Each of the output stage switches 236 has sixteen inputs and eight outputs. If the testing and monitoring functions were shown, then each of the input stage switches 216 would have ten inputs and each of the output stage switches 236 would have ten outputs.
For switch fabric 200 , the input stage switches 216 and the output stage switches 236 are combined as Clos input/output modules.
The fiber routing between modules is unchanged when the switch fabric 200 is upgraded by upgrading the center switches 226 to 1,000 port by 1,000 port switches and by adding more Clos input/output modules. In other words, the center switches 226 are replaced by sixteen 1,000 port by 1,000 port center stage switches. Additional Clos I/O modules are added so that there are 1,000 input switches 216 and 1,000 output switches 236 .
This upgrade approach has the disadvantage that the 250 port center stage switches 226 need to be replaced. Nevertheless, the center stage switches 226 may be reused in some other smaller capacity optical switch somewhere in the optical network.
For alternative embodiments, this upgrade approach could be used for smaller or larger switch fabrics.
For yet other alternatives embodiments, the upgrade approach can operate in reverse to downgrade switch fabric capacity. This downgrade path would be accomplished by replacing large center stage switches (such as 1,000 port×1,000 port center stage switches) with smaller center stage switches (such as 250 port by 250 port center stage switches).
Another upgrade approach is to use 1,000 port by 1,000 port center stage switches, but to install only a portion of them. FIG. 8 illustrates switch fabric 250 that uses this upgrade approach. For switch fabric 250 , the fiber routing is unchanged as the switch fabric 250 is upgraded. Switch fabric 250 includes input stage 260 , center stage 270 , and output stage 280 . Input stage 260 has 500 input stage switches 266 . Center stage 270 has eight center stage switches 276 . Output stage 280 has 500 output stage switches 286 . For the initial configuration of switch fabric 250 , there are 2,000 inputs 264 and 2,000 outputs 284 .
The approach shown in FIG. 8 starts with partially populated center switches 276 . For switch fabric 250 , only one half of the 1,000 port by 1,000 port center switches 276 are loaded so there are only 8 center stage switches 270 in FIG. 8 . Therefore, center stage switches 276 are only acting functionally as 500 port by 500 port switches. The eight port by sixteen port input stage switches 266 are only operating functionally as four inputs by eight outputs switches because only half of the center stage switches 256 are loaded as compared to switch fabric 60 shown in FIG. 5 . Likewise, the sixteen port by eight port output stage switches 286 are only operating functionally as eight inputs by four outputs stage switches.
For the sake of simplicity, the test and monitoring functions are not shown for switch fabric 250 . Therefore, the two additional inputs for each input stage switch 266 for test and monitoring functions are not shown. Likewise, the two additional output ports for test and monitoring for each of the output stage switches 286 are not shown.
The input stage switches 266 and the output stage switches 286 are combined into Clos input/output modules. One half of the Clos input/output modules need to be installed to realize a 2,000 port switch fabric, so this approach is most useful for small initial implementations where the benefit of not needing to replace the center stage switches 276 outweighs the inefficient utilization of the Clos input/output modules that comprise the input 266 and output 286 switches. The approach shown in FIG. 8 has the advantage that the switch fabric capability is doubled when the center stage switches 276 are fully installed without installing any additional Clos input/output modules. In other words, if eight additional 1,000 port center stage switches 276 are added to switch fabric 250 , the capacity of switch fabric 250 doubles, and switch fabric 250 becomes a 4,000 port Clos switch. Once the eight additional center stage switches are added (resulting in sixteen center stage switches 276 ), then the input stage switches 266 begin to operate as eight inputs by sixteen outputs switches and the output stage switches 286 begin to operate as sixteen inputs by eight outputs switches. This results in the number of inputs 264 becoming 4,000 and the number of outputs 286 becoming 4,000. To further upgrade the switch fabric 250 to a 8,000 port Clos redundant strict sense nonblocking switch, 500 additional eight by sixteen port input stage switches 266 can be added and 500 additional sixteen by eight port output stage switches 286 can be added. The number of center stage 1,000 port by 1,000 port switches 276 remains at sixteen. Given that input stage switches 266 and output stages switches 286 are combined into Clos input/output modules, this means that only five hundred Clos input/output modules need to be added to make the switch fabric go from 2,000 ports to 8,000.
For alternative embodiments, this upgrade approach could be used for smaller or larger switch fabrics.
For yet other alternative embodiments, this upgrade approach can operate in reverse to downgrade switch fabric capacity. In other words, center stage switches and Clos input/output modules can be removed to lower capacity of the switch fabric in a manner that is the reverse of the upgrade path.
Another switch fabric upgrade path is shown with respect to FIGS. 9 through 16 . This upgrade path is referred to as a fiber backplane upgrade. For the fiber backplane upgrade shown in FIGS. 9 through 16 , the fiber routing is changed as the switch fabric is upgraded.
This fiber backplane upgrade starts with switch fabric 300 shown in FIG. 9 . Switch fabric 300 is a 1,000 port switch fabric using Clos components and Clos backplane wiring.
Switch fabric 300 includes input stage 310 , center stage 320 , and output stage 330 . Input stage 310 includes 125 stage switches 316 . Each input stage switch 316 is an eight port by sixteen port switch. Center stage 320 is made up of two center stage switches 325 and 326 . Switches 325 and 326 are each a 1,000 port by 1,000 port switch. Output stage 330 comprises 125 output stage switches 336 . Each of the output stages switches 336 is a sixteen port by eight port switch. There are 125 output stage switches 336 . There are 1,000 optical inputs 314 applied to switch fabric 300 . There are 1,000 optical outputs 334 from switch fabric 300 .
For one embodiment, the input stage switches 316 and the output stage switches 336 are combined to form 125 Clos input/output modules.
For the sake of simplicity, the test and monitoring functions are not shown for switch fabric 300 . If the test and monitoring functions were shown, then input stage switches 316 would have ten inputs each instead of eight, and output stage switches 336 would have ten outputs instead of eight.
The switch fabric 300 of FIG. 9 is generally not considered a Clos architecture given that the Clos input/output modules formed by input and output stage switches 316 and 336 are only functioning as respective one-by-two protection switches and two-by-one protection switches. Therefore, the second center stage switch 326 is redundant.
Switch fabric 300 shown in FIG. 9 depicts a fully loaded 1,000 port center switch configuration. For an alternative embodiment, however, center stage switches 325 and 326 initially could be smaller than 1,000 ports. For that alternative embodiment, the center stage switches 325 and 326 could be upgraded as Clos input/output modules (comprising input switches 316 and output 336 ) are added to switch fabric 300 , while the same fiber backplane is maintained.
Switch fabric 300 has an optical backplane comprising sixteen fiber bundles or fiber cables, each with 250 fibers. There are 250 fibers in each bundle because the Clos input/output modules combine the 125 input stage switches 316 and the 125 output stage switches 336 . Accordingly, one end of each fiber cable contains one output fiber and one input fiber with respect to each Clos input/output module in the switch fabric 300 . These fibers are connected to different Clos input/output module fiber connectors. For one embodiment, there could be a single 32-fiber connector for each Clos input/output module. If test and monitoring functions are included in the switch fabric then the fiber connector for each Clos input/output module would be bigger than 32 fibers because it would include additional overhead fibers.
At the other end of each of the sixteen fiber cables, all 250 fibers terminate in a single fiber connector that goes to 125 input ports and 125 output ports of the corresponding center stage 320 switch—i.e., either center switch 325 or center switch 326 . For the switch fiber 300 shown in FIG. 9 , which has 1,000 port by 1,000 port center stage switches 325 and 326 , all of the sixteen fiber cables terminate in the center stage 320 .
FIG. 10 illustrates switch fabric 350 , which is a simplified schematic representation of the same 1,000 port switch configuration 300 shown in FIG. 9 . Switch fabric 350 of FIG. 10 is also referred to as switch fabric subsystem 350 , switch subsystem 350 , or subsystem 350 . For switch fabric 350 , all of the 8 port by 16 port input stage switches 316 are shown as single switchbox 366 of input stage 360 . Likewise, all of the 16 port by 8 port output stage switches 336 of FIG. 9 are shown in FIG. 10 as switchbox 386 of output stage 380 . In addition, the center stage switches 325 and 326 of FIG. 9 are combined in FIG. 10 to form center stage switchbox 376 , which comprises 1,000 port by 1,000 port switch 375 and 1,000 port by 1,000 port center stage switch 377 of center stage 370 .
FIG. 10 shows eight fiber cables 368 connecting input stage switches 366 with center stage switch 375 . FIG. 10 also shows eight fiber cables 369 connecting input stage switches 366 with center stage switch 377 . Each of the eight fiber cables 368 has 125 fibers. Likewise, each of the fiber cables 369 has 125 fibers.
Fiber cables 378 comprise eight fiber cables connecting center stage switch 375 with output stage switches 386 . Fiber cables 379 comprise eight fiber cables connecting center stage switch 377 with output stage switches 386 . Each fiber cable of the eight fiber cables 378 has 125 fibers. Likewise, each of the eight fiber cables 379 has 125 fibers.
For one embodiment, the input stage switches 366 and output stage switches 386 are combined into Clos input/output modules. The fiber cables 368 , 369 , 378 , and 379 are thus coupled to the Clos input/output modules as well as being coupled to the center stage switches 376 . For Clos I/O modules, the fiber cables 368 and 378 would be combined and have 250 fibers, and the fiber cables 369 and 379 would be combined and have 250 fibers.
The switch fabric 350 thus represents a switch subsystem with 1,000 inputs 364 and 1,000 outputs 384 . Fiber connectors may be moved by disconnecting a fiber connector from a 1,000 port switch subsystem such as subsystem 350 and moving the fiber connector to another 1,000 port switch subsystem. The fiber backplanes of these switch subsystems may be configured at the factory to connect to all of the Clos input/output modules. For one embodiment, only the large 250 port fiber connectors are reconfigured to change the overall switch fabric size.
FIG. 11 shows a upgrade path for transitioning from the 1,000 port switch fabric 350 (of FIG. 10 ) with one-to-one protection to a 2,000 port Clos switch fabric while live traffic is being carried.
FIG. 11 shows switch fabric subsystems 350 and 400 . Switch fabric subsystem 350 includes an input stage 360 , a center stage 370 , and an output stage 380 . For subsystem 350 , there are 1,000 inputs 364 and 1,000 outputs 384 . Switch fabric 350 includes 125 eight port by sixteen port input stage switches 366 and 125 sixteen port by eight port output stage switches 386 . For the sake of simplicity, test and monitoring functions are not shown for switch fabrics 350 and 400 . Switch fabric 350 also includes center stage switches 376 , which comprise 1,000 port by 1,000 port switch 375 and 1,000 port by 1,000 port switch 377 .
Fiber bundle 368 is comprised of four fiber cables 391 and four fiber cables 392 . Fiber bundle 369 is comprised of four fiber cables 393 and four fiber cables 394 . Fiber bundle 378 is comprised of four fiber cables 395 and four fiber cables 396 . Fiber bundle 379 is comprised of four fiber cables 397 and four fiber cables 398 . For one embodiment, each fiber cable of fiber cables 391 through 398 is comprised of 125 optical fibers.
Switch fabric subsystem 400 includes input stage 410 , center stage 420 , and output stage 430 . Subsystem 400 has 1,000 optical inputs 414 and 1,000 optical outputs 434 . Input stage 410 is comprised of 125 eight port by sixteen port optical switches 416 . Output stage 430 is comprised of 125 sixteen port by eight port optical output stage switches 436 . Center stage 420 is comprised of center stage switches 426 , which comprise 1,000 port by 1,000 port center stage switch 425 and 1,000 port by 1,000 port center stage switch 427 .
Initially, switch fabric subsystem 350 is configured as shown in FIG. 10 , with eight fiber bundles going to each center switch. Thus, eight fiber bundles 368 go to center stage switch 375 , eight fiber bundles 369 go to center stage switch 377 , eight fiber bundles 378 leave center switch 375 , and eight fiber bundles 379 leave center stage switch 377 .
In order to switch the fiber cables over to another subsystem while live traffic is being carried, all connections first are routed to one center stage switch. Therefore, for one embodiment, all connections are first routed to center stage switch 375 . Four of the cables 394 from switch fabric subsystem 350 are routed to the second switch fabric subsystem 400 that has been added, as shown in FIG. 11 . This moving of the cables 394 to subsystem 400 is done while fiber cables 391 , 392 , 395 , and 396 continue to carry live traffic.
As shown in FIG. 11 , fiber cables 394 are routed from input stage switches 366 of switch fabric 350 to center stage switch 425 of switch fabric 400 . Likewise, fiber cables 398 are routed from center stage switch 425 of switch fabric 400 to output stage switches 386 of switch fabric 350 . The switch fabric 350 is not fully redundant during this fiber reconfiguration given that there is not a backup to the 1,000 port by 1,000 port center stage switch 375 while the fiber cables are being rerouted. During this rerouting, all live traffic is carried through center stage switch 375 .
The fiber bundles 391 , 393 , 394 , 395 , 397 , and 398 can be used to form a 1,000 port Clos switch shown in FIG. 11 that includes subsystems 350 and 400 . The input stage switches 366 and output stage switches 386 are combined to form Clos input/output modules. In addition, the input stage switches 416 and output stage switches 436 are combined into Clos input/output modules. For Clos I/O modules, each fiber cable pair 391 / 395 , 392 / 396 , 393 / 397 , and 394 / 398 would be combined to form a fiber cable with 250 fibers.
After the rerouting of fiber cables 394 and 398 to center switch 425 , the Clos input/output module switches of FIG. 11 can be partitioned into two port by four port input stage Clos switches and four port by two port output stage Clos switches instead of one port by two port protection switches and two port by one port protection switches. Consequently, all live traffic can then be shifted off of the fiber bundles 392 and 396 shown in FIG. 11 . Live traffic would then be carried by fiber bundles 391 , 393 , 394 , 395 , 397 , and 398 . That transition of live traffic represents a transition from an unprotected 1,000 port switch fabric to an unprotected Clos 1,000 port switch fabric made up of subsystems 350 and 400 .
Redundancy of the center stage switches 376 and 426 can be added by moving the extra sets of fiber bundles 392 and 396 to the 1,000 port by 1,000 port center stage switch 427 as shown in FIG. 12 . Fiber cables 392 are coupled between input stage switches 366 and center stage switch 427 . Fiber cables 396 are coupled between center stage switch 427 and output stage switches 386 .
The upgrade to a redundant Clos 2,000 port switch fabric 480 by the connection of fiber cables 461 , 462 , 463 , 464 , 471 , 472 , 473 , and 474 is shown in FIG. 13 . Each of the fiber cables contain 125 fibers. For Clos I/O modules, each fiber cable pair 461 / 463 , 462 / 464 , 471 / 473 , and 472 / 474 would be combined to form a fiber cable with 250 fibers. Switch fabric 480 has 2,000 optical inputs 444 and 2,000 optical outputs 454 . Four fiber cables 461 are coupled between input stage switches 416 and center stage switch 375 . Four fiber cables 463 are coupled between center stage switch 375 and output stage switches 436 . Four fiber cables 462 are coupled between input stage switches 416 and center stage switch 377 . Four fiber cables 464 are coupled between center stage switch 377 and output stage switches 436 . Four fiber cables 471 are coupled between input stage switches 416 and center stage switch 425 . Four fiber cables 473 are coupled between center stage switch 425 and output stage switches 436 . Four fiber cables 472 are coupled between input stage switches 416 and center stage switch 427 . Four fiber cables 474 are coupled between center stage switch 427 and output stage switches 436 . Switch traffic is routed through the fiber cables 391 – 398 , 461 – 464 , and 471 – 474 .
The configuration of switch fabric subsystems into a 4,000 port optical switch fabric 500 is shown in FIG. 14 . The upgrade method starts with 1,000 port optical switch fabric 350 that has been discussed above in connection with FIGS. 10 through 13 .
In FIG. 14 , additional switch fabric subsystems 520 , 521 , and 522 (i.e., respective subsystems numbers 2 , 3 , and 4 ) are added to subsystem 350 (subsystem number 1 ) to form switch fabric 500 . Switch fabric 500 has 4,000 optical inputs 504 and 4,000 optical outputs 514 . Each of the switch fabrics subsystems 350 , 520 , 521 , and 522 has 1,000 optical inputs and 1,000 optical outputs. For the sake of simplicity, subsystems 521 – 522 are shown in block diagram form as residing within block 501 .
FIG. 15 shows the configuration of switch fabric subsystems into an 8,000 port switch fabric 600 . The starting point is switch fabric 350 , discussed above in connection with FIGS. 10–14 . Switch fabric subsystems 620 through 626 (i.e., respective subsystems numbers 2 through 8 ) are added to switch fabric subsystem 350 (subsystem number one) to form switch fabric 600 , which has 8,000 optical inputs 604 and 8,000 optical outputs 614 .
Switch fabric subsystems 620 through 626 are shown in block diagram form as part of block 601 .
For the sake of simplicity, ports for test and monitoring functions are not shown in FIGS. 14 and 15 with respect to switch fabrics 500 and 600 .
The methods for upgrading to the higher capacity switch fabrics 500 and 600 of FIGS. 14 and 15 by reconfiguring the fiber backplane are analogous to the method for upgrading from a 1,000 port optical switch to a 2,000 port optical switch shown in FIGS. 10–13 . For switch fabrics 500 and 600 , one of the center stage switches is redundant. The fiber cables to this redundant switch can be disconnected and rerouted to additional subsystems.
Traffic can be switched from one of the active center stage switches into these additional subsystems, allowing fiber cables going to the previously active switch to be rerouted into additional switch fabric subsystems. This method is repeated until the active switch fabric subsystems have been completed reconfigured. Afterward, new fiber cables are added to the new switch fabric subsystems.
The fully configured 4,000 port switch fabric 500 of FIG. 14 has four switch fabric subsystems 350 , 520 , 521 , and 522 . The 8,000 port fully configured switch fabric 600 of FIG. 15 has eight switch fabric subsystems 350 , 620 – 626 . Each of the subsystems has 1,000 optical input ports and 1,000 optical output ports.
As shown in FIG. 14 , for switch fabric 500 , two fiber cables 551 are coupled between input stage switches 366 and center stage switch 375 . Two fiber cables 561 are coupled between center stage switch 375 and output stage switches 386 . Two fiber cables 553 are coupled between input stage switches 366 and center stage switch 377 . Two fiber cables 563 are coupled between center stage switch 377 and output stage switches 386 .
Twelve fiber cables 555 are coupled between input stage switches 366 of switch subsystem 350 and the center stage switches of switch fabric subsystems 520 through 522 .
Six fiber cables 552 are coupled between the input stage switches of subsystems 520 – 522 and the center stage switch 375 of subsystem 350 . Six fiber cables 554 are coupled between the input stage switches of switch fabric subsystems 520 – 522 and center stage switch 377 .
Six fiber cables 562 are coupled between center stage switch 375 and the output stage switches of switch fabric subsystems 520 – 522 . Six fiber cables 564 are coupled between center stage switch 377 and the output stage switches of subsystems of 520 – 522 .
Twelve fiber cables 565 are coupled between the center stage switches of subsystems 520 – 522 and the output stage switches 386 .
Each of the fiber cables 551 – 555 and 561 – 565 contains 125 fibers. For an embodiment with Clos I/O modules, the combined fiber pairs 551 / 561 , 552 / 562 , 553 / 563 , 554 / 564 , and 555 / 565 have 250 fibers.
For the switch fabric 600 of FIG. 15 , fiber cable 701 is coupled between input stage switches 366 and center stage switch 375 . Fiber cable 703 is coupled between input stage switches 366 and center stage switch 377 . Fiber cable 711 is coupled between center stage switch 375 and output stage switches 386 . Fiber cable 713 is coupled between center stage switch 377 and output stage switches 386 .
Fourteen fiber cables 704 are coupled between input stage switches 366 of switch fabric 350 and the center stage switches of subsystem 620 and the center stage switches of switch fabric subsystems 620 through 626 . Seven fiber cables 702 are coupled between the input stage switches of subsystems 620 – 626 and center stage switch 375 . Seven fiber cables 705 are coupled between the input stage switches of subsystems 620 through 626 and center stage switch 377 .
Seven fiber cables 712 are coupled between center stage switch 375 and the output stage switches of subsystems 620 through 626 . Seven fiber cables 715 are coupled between center stage switch 377 and the output stage switches of subsystems 620 through 626 .
Fourteen fiber cables 714 are coupled between the center stage switches of subsystems 620 through 626 and output stage switches 386 .
Each of the fiber cables 701 – 705 and 711 – 715 contains 125 fibers. For an embodiment with Clos I/O modules, each combined fiber cable pair 701 / 711 , 702 / 712 , 703 / 713 , 704 / 714 , and 705 / 715 has 250 fibers.
The 8,000 port Clos switch fabric 600 of FIG. 15 can be upgraded to the 16,000 port switch fabric 800 of FIG. 16 . Switch fabric 800 has 16,000 optical input ports 804 and 16,000 optical output ports 814 . Switch fabric 800 has sixteen switch fabric subsystems. The starting point is switch fabric subsystem 810 , which is subsystem number one. Subsystem 810 has an input stage 970 , a center stage 980 , and an output stage 990 . Switch fabric subsystem 810 includes 125 eight port by sixteen port input stage switches 976 and 125 sixteen port by eight port output stage switches 996 . An additional fifteen switch fabric subsystems 820 through 835 (i.e., subsystems numbers 2 – 16 ) are coupled to subsystem 810 . The switch fabric subsystems 820 through 835 are shown in block diagram form as part of block 801 .
For the sake of simplicity, the ports for test and monitoring functions are not shown as part of switch fabric 800 in FIG. 16 .
The 8,000 port switch fabric 600 shown in FIG. 15 is upgraded to 16,000 port switch fabric 800 by replacing each pair of 1,000 port center stage switches of switch fabric 600 with a single 2,000 port center stage switch. Thus, subsystem 810 of FIG. 16 includes a 2,000 port by 2,000 port center stage switch 986 . Each of the additional subsystems 820 through 835 also contains a 2,000 port by 2,000 port center stage switch. Each of the 2,000 port by 2,000 port center stage switches (including center stage switch 986 ) has a total of sixteen fiber input connectors and sixteen fiber output connectors, each of the fiber connectors having 250 fibers.
For fully configured switch fabric 800 , fiber cable 802 couples input stage switches 976 to center stage switch 986 . Fiber cable 808 couples center stage switch 986 with output stage switches 996 .
Fifteen fiber cables 805 couple input stage switches 976 to the center stage switches of switch fabric subsystems of 820 through 835 . Fifteen fiber cables 806 couple the center stage switches of switch fabric subsystems 820 through 835 to center stage switch 986 .
Fifteen fiber cables 812 couple center stage switch 986 to the center stage switches of switch fabric subsystems 820 through 835 . The fifteen fiber cables 815 couple the center stage switches of switch fabric subsystems 820 through 835 to the output stage switches 996 .
Fiber cables 802 and 808 have 125 fibers. Each of fiber cables 805 , 806 , 812 , and 815 consist of 15 cables each with 125 fibers. Each of the fiber cables 805 , 806 , 812 , and 815 consist of 15 cables each with 125 fibers. For an embodiment with Clos input/output modules, input cable 802 and output cable 808 can be combined into one cable with 250 fibers. Similarly, input and output cables 805 and 815 or input and output cables 806 and 812 can be combined into 15 groups each with 250 fibers.
The upgrade methods described above in connection with FIGS. 9–15 do not interrupt working optical signals. For alternative embodiments, the switch capacity upgrades could still be employed even if working optical signals were interrupted or switched off.
For alternative embodiments, the fiber backplane upgrade approaches of FIGS. 9–16 could be used for smaller or larger switch fabrics.
For yet other alternative embodiments, the fiber backplane approaches of FIGS. 9–16 could operate in reverse in order to downgrade switch fabric capacity. For example, with respect to FIGS. 9–13 , a fiber backplane downgrade would entail rerouting traffic to fiber cables 391 – 397 , removing fiber cables 461 – 464 and 471 – 474 , rerouting traffic away from fiber cables 392 and 396 , moving fiber cables 392 and 396 from center stage switch 427 to center stage switch 375 , rerouting traffic away from fiber cables 394 and 398 , moving fiber cables 394 and 398 from center stage switch 425 to center stage switch 377 , and rerouting traffic through fiber cables 391 – 398 . The switch fabric would thereby be downgraded from a redundant Clos 2,000 port switch fabric with two switch subsystems to a 1,000 port switch fabric with one switch subsystem. Similar approaches could be used to downgrade the 4,000 port, 8,000 port, and 16,000 port switch fabrics shown in respective FIGS. 14–16 .
Although embodiments of the invention have been described that specify, for example, the number of optical inputs, optical outputs, the number of fiber cables and fibers, the number of switch stages, and the number of switch subsystems, it is to be appreciated that other embodiments are contemplated that include different numbers of inputs, outputs, fiber cables, fibers, subsystems, and stages, etc. Although for some embodiments, ports for testing and monitoring functions were not shown for the sake of simplicity, it is to be appreciated that for various embodiments the ports for the testing and monitoring functions can be included and can have various numbers of lasers, detectors, and fiber inputs and outputs. Furthermore, although particular upgrade methods have been described with respect to specific number of ports, input switches, output switches, center stage switches, and subsystems, other upgrade methods are contemplated that involve different numbers of input switches, center stage switches, output stage switches, input ports, output ports, and subsystems. Although particular Clos input/output modules have been discussed, Clos input/output modules of different sizes with different numbers of inputs and outputs, different numbers of mirror arrays, and different number of fibers, detectors, taps, and lasers are contemplated.
In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. | An optical switch fabric with an input stage, an output stage, and a center stage coupled in a cascaded manner. The center stage includes (1) a minimum number of center switches greater than one that cause the optical switch fabric to be strict-sense nonblocking and (2) at least one additional center switch to provide redundancy for the optical switch fabric. A module is described that includes optical input and output switches coupled to an optical center stage of an optical switch fabric. The module includes an interior cavity that contains free space beams from both the optical input switch and the optical output switch. A method is described for reconfiguring a redundant optical switch into a multilevel optical switch without interrupting operation of the signals carried by the optical switch by adding additional switch components and reconfiguring the fiber interconnection between switch elements. | 7 |
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