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[0001] The present invention relates to a chair for supporting rebars in spaced relationship above a surface over which poured concrete is formed. It is particularly concerned with a unitary chair fabricated of polymeric material wherein the legs of the chair present smooth outer surfaces and are internally formed with reinforcing webs which terminate in distal feet. In its more specific aspects, the invention is concerned with such a chair which may be injection molded and is of a very strong and stable construction. The invention also provides a bearing plate to support the chair against tipping or penetration relative to a soft earthen bed upon which the chair is supported.
[0002] The rebar chair of the invention may also be referred to as a pedestal. While the invention is described with reference to rebar, it may also be used to support other internal reinforcements for poured concrete, such as post tensioned cables or welded wire mesh.
BACKGROUND OF THE INVENTION
[0003] Chairs or pedestals for supporting rebar in spaced relationship to a surface over which poured concrete is formed are well known in the prior art. Some comprise no more than small concrete blocks provided with wire to secure the blocks to the rebar. Others are fabricated of bent wire. More recently, a number have been made of polymeric material. The devices of U.S. Pat. Nos. 4,682,461; 4,756,641; and 5,555,693 are typical of the later type.
[0004] While polymeric chairs have the advantage that they are relatively inexpensive and do not corrode, they have been problematic insofar as their strength and stability is concerned. Also, they have met with resistance in the trade because of the difficulty of securing the chairs to the rebar being supported. The later problem has been exacerbated by the provision of internal structure between the legs of the chairs, which structure has restricted free access between the legs. Such restricted access makes it difficult to extend ties through the chairs and also impedes stackability of the chairs during storage and transport.
[0005] Another problem with prior art polymeric chairs is that their relatively complicated construction has made it difficult and expensive to manufacture the chairs by injection molding.
SUMMARY OF THE INVENTION
[0006] The principal elements of the chair of the present invention comprise a cradle for supporting engagement with a rebar and legs fixed to and extending downwardly from the cradle at annularly spaced locations. The legs diverge outwardly from the cradle and are formed with arcuate outer surface portions which define a smooth interrupted cone. Web portions extend inwardly of the outer portions over the length of the legs and terminate in distal ends which provide feet to the interior of the outer portions. The feet are formed with irregular bottom surfaces to enhance traction. The cradle is provided by a table having diametrically opposed ears extending upwardly therefrom; which ears may be located so as to be intermediate the legs, or in alignment with the legs.
[0007] In one embodiment, a ring is integrally formed with and extends between the legs to reinforce the legs against spreading. The ring is located at a level between the cradle and the distal ends of the legs and is of an arcuate configuration which merges with the outer portions of the legs to continue the interrupted conical surface defined by the legs.
[0008] Another embodiment has a strap integrally formed with the chair for select extension over the cradle to secure a rebar within the cradle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a perspective view of a first embodiment of the inventive chair wherein a ring is formed integrally with the legs;
[0010] FIG. 2 is a elevational view of the first embodiment chair, with a part thereof broken away to show the internal construction of the chair;
[0011] FIG. 3 is a plan view of the first embodiment chair;
[0012] FIG. 4 is a bottom view of the first embodiment chair;
[0013] FIGS. 5 and 6 are cross-sectional views taken on the planes designated by lines 5 - 5 and 6 - 6 , respectively, of FIG. 1 ;
[0014] FIG. 7 is a perspective view of a second embodiment of the inventive chair, wherein no ring is provided between the legs of the chair;
[0015] FIG. 8 is an elevational view of the second embodiment chair;
[0016] FIG. 9 is a plan view of the second embodiment chair;
[0017] FIG. 10 is a bottom view of the second embodiment chair;
[0018] FIG. 11 is a cross-sectional view taken on the plane designated by line 11 - 11 of FIG. 7 ;
[0019] FIG. 12 is a plan view of the bearing plate of the present invention;
[0020] FIG. 13 is a cross-sectional view of the bearing plate, taken on the plane designated by line 13 - 13 of FIG. 12 ;
[0021] FIG. 14 is a perspective view of the FIG. 12 bearing plate;
[0022] FIG. 15 is a perspective view of the first embodiment chair of FIG. 1 , shown supported on the bearing plate of FIG. 12 ;
[0023] FIG. 16 is a cross-sectional elevational view taken on the plane designated by line 16 - 16 of FIG. 15 ;
[0024] FIG. 17 is an elevational view of a third embodiment of the inventive chair, similar to that of FIGS. 1 to 6 , except that it is additionally provided with an integrally formed strap and securing means therefore;
[0025] FIG. 18 is a perspective view of a fourth embodiment of the inventive chair, viewed from toward the top, wherein no ring is provided between the legs of the chair and the table of the chair of a generally X-shaped configuration;
[0026] FIG. 19 is a plan view of the fourth embodiment chair;
[0027] FIG. 20 is a bottom view of the fourth embodiment chair;
[0028] FIG. 21 is an elevational view of the fourth embodiment chair; and
[0029] FIG. 22 is a perspective view of the fourth embodiment chair, viewed toward the bottom.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] All embodiments of the inventive chair are injection molded from polymeric material. A preferred material has been found to be a derivative of recycled polypropylene known as “PRE-TUF” by PrePlastics of Auburn, Calif. Other suitable materials are polycarbonate/ABS alloy, polypropylene, polyethylene, polystyrene, glass filled polystyrene, glass filled nylon, and polyvinyl chloride.
[0031] The dimensions of the chair may vary, depending on the thickness of the concrete slab being formed. Typical chair heights range from one and one-quarter inch to ten inches, in one-quarter inch increments. The angle at which the legs diverge from the supporting table of the chair is chosen for optimum strength and stability, with the preferred range being 94° to 104°.
First Embodiment Chair
[0032] The chair of this embodiment is shown in FIGS. 1 to 6 and designated in its entirety by the letter C 1 . It comprises a horizontal table 10 of a generally circular configuration having ears 12 extending upwardly from diametrically opposite sides thereof to define a rebar receiving cradle 14 ; legs 16 integrally formed with the table 10 and diverging downwardly and outwardly therefrom; and a ring 18 formed integrally with the legs 16 at a location intermediate the table 10 and distal ends of the legs 16 . As shown, four legs 16 are provided and extend downwardly from the table 10 at equally spaced annular locations around the table. The ears are located so as to be between the legs, thus providing a stable arrangement where two legs are disposed to either side of a rebar received in the cradle between the ears.
[0033] As viewed in cross-section (see FIG. 6 ), the legs are of a generally T-shaped cross-section and each comprise an outer surface portion 20 and an inwardly extending reinforcing web portion 22 . The outer surface portions define as interrupted frusto conical cone diverging downwardly from the table 10 . The web portions 22 taper from either end of the legs so as to have an increased depth portion approximately mid-length of the legs (see FIG. 2 ). The later construction provides a truss-like reinforcement for the legs which renders them very rigid. From FIG. 2 it will also be seen that the web portions of oppositely disposed legs include a central portion 24 integrally formed with and extending beneath the table 10 . The merger between the reinforcing web portions 22 and central portion 24 has a relatively large radius, thus adding to the overall rigidity of the chair. The central portions 24 meet at the center of the table 10 (see FIG. 4 ) to add even more to this rigidity.
[0034] The ring 18 merges with the outer surface portions 20 of the legs so as to form a smooth outer surface continuing the interrupted conical configuration defined by the outer surface portions. At the lower edge of the merger between the ring 18 and the outer surface portions 16 , the ring is arched so as to provide radius portions 26 which increase the area of merger between the ring and the legs and serve to expand the reinforcement to the legs provided by the ring. As viewed in cross-section, the ring 18 tapers in thickness from its upper edge 28 to its lower edge 29 (see FIG. 5 ). This configuration ideally suits the chair for injection molding with a core of simple construction which may be readily removed.
[0035] The distal ends of the legs 16 are formed by extensions 30 of the web portions 22 (see FIG. 2 ). These extensions are disposed inwardly on the outer surfaces of the portions 20 and provide a foot including, traction means in the form of serrations 32 , formed on the under-surface of the extensions. The serrations 32 , as may be seen from FIG. 4 , extend transversely of the web portions 22 . The outer surface portions 20 converge towards the extensions 30 through inclined surfaces 34 proximal to the distal ends of the legs. These inclined surfaces provide space proximal to the distal ends of the legs 16 into which fluid concrete formed around the legs may flow, thus avoiding the creation of voids in the concrete. Such voids are also avoided through the use of rounded radiuses 36 at the merger of the web portions 22 and the extensions 32 .
[0036] The cradle defined between the ears 12 extends transversely across the table 10 so that a rebar R (see FIG. 2 ) supported on the table is disposed between the legs 16 . As the result of this arrangement, with a four-legged chair, two legs are disposed symmetrically to either side of the rebar.
Second Embodiment Chair
[0037] This embodiment is shown in FIGS. 7 to 11 and designated, in its entirety, by the reference C 2 . It differs from the first embodiment primarily in that it is not provided with a ring, such as the ring 18 , and in that the web portions converge uniformly towards the distal ends of the legs. Parts of the second embodiment corresponding to those of the first embodiment are designated by like numerals, followed by the reference “a”, as follows:
Table 10 a Ears 12 a Cradle 14 a Legs 16 a Outer surface portions 20 a Reinforcing web portions 22 a Central portion 24 a Extensions 30 a Serrations 32 a Inclined surfaces 34 a
[0048] As may be seen from FIG. 8 , the web portions 22 a converge uniformly in a generally straight line from the central portion 24 a to the extensions 30 a . Another difference between the first and second embodiments is that in the second embodiment a shoulder 38 is formed between the inclined surfaces 34 a and the extensions 30 a.
[0049] The second embodiment operates in the same manner as the first embodiment in that the cradle 14 a extends transversely of the table 10 a between a pair of legs 20 a to either side thereof.
[0050] While the first and second embodiments function in the same way, the first embodiment is especially designed for relatively high chairs where the legs 16 are quite long and the added reinforcement provided by the ring 18 and the truss-like reinforcing of portions 22 greatly enhances the rigidity of the chair structure. The second embodiment is a simplified construction ideally suited for use in relatively short chairs.
Bearing Plate
[0051] The bearing plate shown in FIGS. 12 to 16 is designated in its entirety by the reference B and is for purposes of supporting the chair of the invention against uneven penetration into soft soil. Such plates are also known in the trade as “sand plates.”
[0052] In the illustrated embodiment, the body of plate B is fabricated of a polymer material similar to that of the chair. It is designed to universally accommodate chairs of different heights and may be used to support any of the embodiment of the chairs herein disclosed. A typical plate would measure 4½ by 4½ inches and have a thickness of one-quarter inch.
[0053] The plate B is formed with generally triangular lightening holes 40 and a central hole 42 . These holes are intended primarily to conserve material and lighten the weight of the plate. Diagonally extending slots 44 extend radially relative to the central hole 42 for alignment with and complimental receipt of the extensions 30 , 30 a , and 30 b of the chairs. These slots have a transverse dimension slightly less than that of the extensions, so that the opposed side surfaces of the slots, designated 46 , 48 (see FIG. 13 ) snuggly receive and frictionally engage opposite sides of the extensions.
[0054] FIGS. 15 and 16 show the chair C 1 of the first embodiment with the extensions 30 thereof snuggly received within the slots 44 . As there seen, it will be appreciated that the extensions 30 are disposed intermediate the radially spaced inner and outer extremities of the slots 44 . This demonstrates how a particular bearing plate B may accommodate chairs of different sizes. For smaller chairs, the extensions 30 , 30 a would be closer to the center of the plate.
[0055] The flat planar top surface of the plate B facilitates the formation of concrete around the assembled plate and chair, without creating voids. This contrasts to prior art plates wherein upperwardly extending structure on the plates may create such voids.
Third Embodiment Chair
[0056] The chair of this embodiment is shown in FIG. 17 . It differs from the first embodiment chair in that it is provided with a strap S and retaining tab T therefor. The strap S is integrally formed with the chair C 1 to the outside of an in alignment with one of the ears 12 . The tab T is integrally formed with the chair C 1 in alignment with and extending downwardly from the other of the ears 12 . The thickness of the strap S is such that the strap is relatively flexible. Generally rectangular openings 50 are formed through the strap S at spaced intervals for select engagement over the tab T. The phantom line illustration in FIG. 17 illustrates the condition which the strap would assume when engaged over the tab T. As so engaged, the strap would extend over and retain a rebar supported on the cradle of the chair. The alignment of the strap S with the ears 12 assures that such engagement is secure.
Fourth Embodiment Chair
[0057] The chair of this embodiment is shown in FIGS. 18 to 22 and is designated, in its entirety, by reference C 4 . It differs from the second embodiment primarily in that:
1) the table is of a cross-shaped planar configuration; 2) additional reinforcements are provided beneath the table; and 3) the ears are aligned with oppositely disposed legs of the chair. Parts of the fourth embodiment corresponding to those of the second embodiment are designated by like numerals, followed by the reference “b,” as follows: Table 10 b Ears 12 b Cradle 14 b Legs 16 b Outer surface portions 20 b Reinforcing web portions 22 b Central portion 24 b Extensions 30 b Serrations 32 b Inclined surfaces 34 b Shoulder 38 b
[0072] The fourth embodiment also differs from the second embodiment in that it is provided with additional reinforcing webs 52 integrally formed with the table 10 b and merging with the reinforcing web portions 22 b (see FIG. 20 ). The reinforcing webs 52 function to further rigidify the legs 16 b and to provide additional support for the table 10 b.
[0073] The crossed-shaped configuration of the table 10 b also differs from that of the tables 10 and 10 a in that it is not of a planar configuration. Rather, it is of a generally concave configuration at the portion thereof defining the cradle 14 b . The ears 12 b are of a concave arcuate configuration which merge with the cradle 14 b , as may best be seen from FIG. 21 .
[0074] The cross-shaped table 10 b has inwardly scalloped edges between the legs 16 b (see FIG. 18 ). As compared to the circular tables of the first, second and third embodiments, the scalloped configuration has the advantage that it provides open space between the legs which facilitates extending a tie element beneath the table and over a rebar supported thereon.
CONCLUSION
[0075] From the foregoing description and accompanying drawings, it is believed apparent that the present invention enables the attainment of the objects initially set forth herein. In particular, it provides an improved rebar chair and sand plate of a strong and stable construction which is ideally suited for fabrication by injection molding. It should be appreciated, however, that the invention is not intended to be limited to the details of the illustrated embodiments, but rather is defined by the accompanying claims.
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A polymeric chair having a rebar cradle and legs of a T-shaped cross-section diverging downwardly from the cradle. The outer surface portions of the legs are arcuate and define segments of a cone. Inwardly extending web portions reinforce the legs and provide feet at the distal ends of the legs disposed to the inside of the outer surface portions. A flat sand plate for the chair has radially extending slots formed therethrough which are proportioned for snug engagement with side surfaces of the feet. The slots are elongate to accommodate different sized chairs having feet spaced at varying radial dimensions. The web portions taper to optimize their reinforcing function and conserve material. In one embodiment, a ring is formed integrally with the legs intermediate the table and the distal ends of the legs. The chair is of a unitary construction and may have an integrally formed strap for extension over the cradle to secure a rebar in place.
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TECHNICAL FIELD
The invention relates to gas turbine engines with variable exhaust nozzles, and in particular, to accommodation of compressor fan damage.
BACKGROUND OF THE INVENTION
Gas turbine engines for aircraft often use variable area exhaust nozzles. Such engines may operate at low power in a base control mode, wherein the nozzle area is fixed. Throttle action by the pilot sets either a fuel flow rate or a engine RPM to be achieved, with pressure distribution through the engine settling out at a new value. It is known, however, that the thrust may be increased and the overall efficacy of engine operation improved by changing the area of the nozzle to an optimum condition for the new operating mode. If the nozzle closes too much, it may cause a compressor stall, while if it opens more than is necessary, over expansion within the discharge nozzle occurs.
It is accordingly known to measure the engine pressure ratio, which is the ratio of pressure leaving the gas turbine to the pressure entering the compressor and to operate nozzle to maintain this parameter. Essentially, the pressure ratio is known for the engine design which will, for any particular RPM, provide reasonable tolerance from stall with optimum thrust.
The fan, or first stage of the compressor, of an engine, is susceptible to fan damage in various situations such as the ingestion of birds, ice or other foreign objects. The initial damage may result in a stall event. In accordance with normal procedures the nozzle is opened to an increased area until recovery from the stall, and then closed down to its normal operating position. Since fan damage has occurred, it is quite possible for the engine to continue to repeatedly stall, producing unstable operation. This is possible with a fixed nozzle condition, but even more so when the engine is operating in the engine pressure ratio mode to achieve optimum thrust.
It is an object of the invention to detect and accommodate compressor fan damage, thereby effecting a proper choice of stall recovery action.
SUMMARY OF THE INVENTION
The gas turbine engine of the invention is a turbofan, with low and high pressure compressor, a turbine, an augmentor or afterburner and a variable area exhaust nozzle. A portion of the fan flow passes through bypass ducts to the exit of the turbines. There is a known anticipated engine pressure ratio for any operating air flow and nozzle area condition which represents an undamaged compressor. It operates in the engine pressure ratio control mode with the nozzle being adjusted to maintain a preselected engine pressure ratio at each high load operating condition. It is also capable of operating in a base control mode with a fixed nozzle area.
In accordance with the objective to detect and accommodate fan damage, an enable logic disables the rest of the logic in certain situations where input data would be unreliable.
The relationship between engine airflow, exhaust nozzle area and engine pressure ratio is unique for a turbofan that is undamaged. Damage due to ingestion of foreign objects results in reduced airflow rate of the fan and stall limit for a given rotor speed. Therefore, detection of fan damage is possible by comparing the actual engine pressure ratio for the damaged fan to the predefined engine pressure ratio (EPR), airflow and exhaust nozzle area relationship for the undamaged fan. A percent EPR error is thereby established based on that comparison.
In a fan damage and sensor error detection means, this error is compared to tolerable errors. A relatively low sensor error detect is established where all potential sensor tolerances are on one side. A fan damage detect is set at a higher level. Various responses occur depending on whether the percent error signal is above the fan detect level, below the sensor error detect level, or in the band between the two. Each of these is combined with the signal indicating an immediately preceding stall and the action taken varies depending on whether or not there has been an immediately preceding stall. Action other than stall recovery is not taken until a quasi steady state operation is a achieved. Therefore, the phrase "in the presence of a stall" is the equivalent of "after an immediately preceding stall".
If the error signal obtained is above the fan damage detect level and a stall has also occurred, the action taken depends on whether damage has previously been declared, this in turn being established by the setting of a fan damage flag. In the first instance, with no earlier fan damage detected, a fan damage flag is set. A minimum area of the nozzle is set with this area being selected as a function of the percent EPR error. EPR control is also stopped and after burning or augmentation is inhibited.
Should the EPR error be above the fan damage detect level in the presence of a flag which represents early detected fan damage, the nozzle area is ratcheted to increase the previously selected minimum area or the area measured at stall, whichever is larger, by an additional percentage.
Should the percent error be above the fan damage detect level in the absence of a stall, with no earlier damage detected, a sensor error flag is set and the nozzle area is set at a scheduled minimum area. EPR control requests for exhaust nozzle areas less than the scheduled minimum are ignored, but augmentation is not inhibited.
Should the percent EPR level be above the fan damage detect level in the absence of a stall, but with either the sensor error or the fan damage flag being set, no additional action is taken.
Should the percent EPR error be below the sensor error detect level, regardless of whether or not there was an immediately preceding stall, the sensor error and fan damage flags, if set, are reset. The system is returned to EPR control and afterburning is permitted.
Should the percent EPR error be in the band between the sensor error detect level and the fan damage detect level in the presence of a stall, operation is continued unchanged unless a sensor error or fan damage flag was set previously.
If the percent EPR error is in the band between the sensor error and the fan detect level in the presence of a stall and a flag has been set indicating either sensor error or fan damage error in the past, the nozzle area is increased a preselected amount with afterburner availability being left where ever it was based on the earlier operation.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a gas turbine engine with the prior art control scheme illustrated thereon;
FIG. 2 is a logic diagram of the fan damage detection scheme;
FIG. 3 is additional detail of the enable logic;
FIG. 4 is additional detail of the EPR error calculation;
FIG. 5 is additional detail of the fan damage detection logic; and
FIG. 6 is additional detail of a portion of the fan damage accommodation logic.
FIG. 7 is a modification of FIG. 1 showing application of the fan damage accommodation logic.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a gas turbine engine, shown generally as 10, has a fan or low pressure compressor 12 and high pressure compressor 14. Burners 16 are located upstream of turbine 18 with augmentor flameholders 20 followed by augmentor 22. Variable area exhaust nozzle 24 discharges gas through nozzle area 26.
The known control system of FIG. 1 includes static pressure sensor 28, sensing static pressure at the low pressure compressor inlet. In the designation PS2 represents static pressure and the numeral 2 refers to the location within the engine. A signal representing this pressure passes through control line 30 to total pressure (PT2) calculator 32. It is here combined with a corrected fan speed signal 34 producing a corrected total pressure signal passing through line 36 to a division point 38.
Pressure sensor 40 senses the pressure in the afterburner after the turbine exhaust, passing a total pressure signal through control line 42 to division point 38.
At the division point, the signals are divided thereby obtaining a pressure ratio signal by dividing the pressure PT6 by the pressure PT2. The signal is passed through control line 44 to comparison point 46 where it is compared to an EPR set point signal 48. This set point signal is a preselected characteristic which is a function of the corrected engine speed and the total inlet pressure PT2, corrected. Any difference here results in a control error signal through line 50 which with appropriate proportional and integral action 52 passes to multiplier 54 where AJ scheduling as a function of the base schedule is performed. This signal then acts through actuator 56 to adjust nozzle area 26 to achieve the set point EPR request.
The above described control loop which modifies the nozzle area to obtain a desired EPR is operative at high loads, for instance, greater than 90% power. At lower power, a base mode of operation is used wherein a control signal 58 representing a desired nozzle area passes through multiplier 54 to actuator 56 to set the nozzle at the desired area. In this case, proportional and integral trim request for AJ less than the base schedule are ignored such that the signal from 52 to multiplier 54 will be 1 or greater. The base area schedule is a function of inlet total temperature and inlet total pressure under normal operating conditions with an additional increase for augmentation operation.
The above described control schemes are based on known engine aerodynamics and are established to maintain a reasonable tolerance from a compressor stall condition. When a stall does occur, the nozzle is opened for stall recovery and then returned to the preexisting control position. In the event of damage to fan 12, the aerodynamics of the engine change, increasing the probability of a stall. With such an operating scheme, once recovery from a stall is accomplished, the engine reverts to its initial mode and if fan damage caused the stall, the engine would continue to stall and recycle resulting in unstable operation.
Normal stall recovery procedures involving the opening of nozzle 24 are unimpeded by my invention. The fan damage detection processing unit 59 (FIG. 7) incorporating the scheme shown generally in FIG. 2 operates to detect fan damage or sensor error which may cause stalling and to take appropriate action. After normal stall recovery techniques are used, the engine operates with the large area nozzle until the fan damage detection scheme described below performs its function. Operation then goes to the mode as determined by the fan damage detection scheme.
Enable logic means 60 (shown in more detail in FIG. 3) disables the detection scheme under conditions which would produce erroneous results. Typical inputs to enable the logic are shown in FIG. 3, wherein input 62 represents that the appropriate pressure and speed sensors have not failed. This is differentiated from the sensor error which produces erroneous readings which are accommodated later in the scheme. Signal 63 requires a quasi-steady state operation to enable the system. Signal 64 requires that operation be nonaugmented. Signal 65 requires that the operation be within predetermined limits. For instance, the engine must be above a selected speed with the nozzle area below a selected size. The inlet pressure must be above a preselected value, such as, 0.4 atmospheres to assure that the sensor is operating in a range where its tolerance would not adversely affect the system.
If all of the enablement conditions are met, an enabling signal passes through line 66 to EPR calculation means 70.
Input to the EPR error calculation means 70 includes the measured EPR 71, the airflow 72 and the nozzle area 73. As indicated in more detail in FIG. 4, an undamaged engine has a known relationship 74 for any particular nozzle area with the anticipated engine pressure ratio being known as a function of airflow. Accordingly, from the input airflow and nozzle area an anticipated EPR is determinable. This is compared to the measured EPR to obtain a percent error signal in accordance with the formula EPR anticipated minus EPR measured divided by EPR measured times 100. A percent error signal accordingly is sent through control lines 76. The signal also passes through control line 77 for purposes which will be described hereinafter, but for current purposes it passes to fan damage and sensor error detect means 80.
The fan damage and sensor error detection means 80 also has as input a total pressure signal 82 representing the total pressure at the compressor inlet. As shown in more detail in FIG. 5, the logic defines a sensor error detect relationship 84 where the percent EPR error is shown as a function of the inlet pressure. This substantially represents the error which would occur if the tolerance of all sensing apparatus was off the ideal in a single direction. A fan damage detect relationship 86 is also established including some tolerance above the sensor error detect curve, for instance, 5% greater. A dead band 87 occurs between these two curves.
Within this detection means a percent error signal is compared to the detect curves producing one of three signals depending on whether the error is greater than the fan detect level 88, less than the sensor error level 90, or between the sensor error and the fan detect levels 92. As these control signals pass to the fan damage accommodation means, different actions are taken, not only with the three different signals, but in combination with each one of them as a function of whether or not there has been an immediately preceding stall, and also whether or not fan damage or sensor error has previously been declared.
Looking first at a situation where the error is greater than the fan damage detect level, an immediately preceding stall exists, and damage has not already been declared, the signal through line 88 passes to AND box 102 (FIG. 2). Stall detector 104 has passed a signal indicating a stall through line 106 to memory 108 which retains information indicating an immediately preceding stall. The YES signal for the preceding stall passes through line 110 to AND box 102. The signal passes to query box 112 questioning whether previous fan damage or sensor error has been declared. This would be noted by the establishment of flags, but at this point we are assuming that no damage has earlier been declared.
Accordingly, a signal passes through control line 113 to set FD flag box 114. This sets the flag for fan damage so that the logic later knows that fan damage was early declared. The signal then passes on to control line 115 to fan damage accommodation area set logic 116, shown in more detail in FIG. 6.
The early described percent EPR error signal passing through line 77 from EPR error calculation means 70 is used at this point and herein enters into the logic. Within the logic are three relationships representing the area with respect to the percent EPR error signal.
Curve 118 represents the nozzle area to be set based on the percent EPR error which is expected to avoid subsequent stalls. Curve 120 represents the area in relationship to the percent EPR error which will produce 75% thrust. Curve 122 represents the area for EPR error calculation after a stall and also the open limit for base mode operation.
The fan damage accommodation area set selects, based on the percent EPR error established, a minimum area to be established for the nozzle. This is preferably the no stall line 118 for the lower errors and the 75% thrust lines at the higher errors where it produces a lower nozzle area. This provides an increased nozzle area attempting to prevent further stalls while producing 75% thrust or greater, but as will be seen hereinafter, if this area is not sufficient, further corrective action will be taken.
Since an EPR error of this magnitude would invalidate the EPR control apparatus, EPR control is stopped and base mode control is established based on the selected nozzle area. Afterburning is also inhibited. In summary, in response to the high fan damage signal and an immediately preceding stall, a fan damage flag is set in the first instance, EPR control is stopped and afterburning is inhibited.
Returning now to the detect means 80 with a greater than fan damage detect signal 88, functions will be considered in response to a preceding fan damage determination. The presence of an immediately preceding stall is assumed so that the signals pass through AND box 102 to the previous declaration box 112. In this case, the flag has been set previously and accordingly control signal passes through control line 119 to increase area logic box 121. In accordance with the logic of that box, the nozzle area is increased a preselected amount, for instance 5%. No other change is made. If desired, a limit could be placed on the maximum area to be set.
In response to the above described logic the engine is operating on a base mode control scheme with a minimum nozzle area being established and for all practical purposes, maintained. The nozzle area may be increased during transient conditions, for instance, an impending or actual stall recovery condition.
Returning again to detection logic 80, it will be assumed that an error greater than a fan detect level exists in the absence of a stall, and further in the absence of a previously set fan damage or sensor error flag. The error signal 88 is combined with a no stall signal 123 in the AND box 124. This condition should be maintained for some time period, approximately 20 seconds, to further validate the detection accuracy. Since we are assuming that damage has not early been declared, the signal passes through declaration box 126 and line 127 to set sensor error flag 128. The sensor error flag is a record of the prior existence of the present described operation. The signal continues through line 129 to a nozzle area box 130.
Since the apparatus has indicated a high level of error, but no stall has occurred, it is assumed that a sensor error exists. Accordingly, control logic 130 sets the minimum nozzle area to the base value of 0.28 meter squared and stops EPR control. Afterburning is not inhibited.
Returning once more to detection logic 80, the greater than fan detect level signal, in conjunction with no stall, will be considered in light of a previously set flag. The signals again pass through the AND box 124 to the previous declaration box 126. If fan damage or sensor area has previously been declared, no action is taken.
The signal through line 90 of detect logic 80 represents a percent error signals which is lower than the sensor error detect level. If such a low signal is determined, nothing need be done where damage has never been declared. However, should damage have been previously declared, this low error level provides justification for resetting operation to avoid the inhibitions earlier placed on the system. Accordingly, the control signal from 90 passes through declaration box 132 to reset action box 134 where any previously set fan damage or sensor error flag is reset. The signal further passes through control line 135 to logic box 136 which releases the minimum nozzle area restriction, returns the system to EPR control and permits afterburning.
As described herein, a control signal through line 92 is produced by detect logic 80 when the error is in the band between the sensor error detect level and fan damage detect level. It is intended that in this area, if there is no stall, that no action be taken. If a stall of first occurrence happens, it is desirable to continue the control as is since the fan damage detect level has not been exceeded. However, if the previous damage was declared, as established by setting either the fan damage flag or the sensor error flag, it is desired to ratchet the nozzle area by increasing it 5%.
In order to achieve this, the control signal line 92 passes to AND box 140 which requires the presence of a immediately preceding stall signal 110 to send a control signal through control line 141. Previous damage query box 142 operates such that in the event of no previous damage declaration, control signal through line 144 permits operation to continue as before.
If damage had previously been declared a signal through line 146 passes to increase nozzle area box 120 to increase the minimum nozzle area by 5%.
FIG. 7 illustrates the incorporation of the logic into the gasic EPR control system. The central processing unit 59 permits the control signal in line 50 to pass through until modification of the signal is imposed by the unit 59.
Burner pressure sensor 150 sends a signal to stall detector 152. In the event of a stall a signal is sent through line 154 to the CPU 59.
The fan speed signal 34 is indicative of air flow and is sent as signal 72 to the CPU 59. Total pressure signal passing through line 36 is also sent to the CPU through line 82. A position signal 73 representing nozzle area is sent to the CPU. Also, the actual pressure ratio signal in line 44 is sent though line 71 to the CPU 59.
Steady state signal 63 and nonaugmentation signal 64 enter the CPU. Signal 62 entering the CPU indicates that the appropriate sensors have no failure indication, while signal 64 indicates that operation is within preselected limits.
In response to logic 116, a signal for inhibiting augmentor or after-burner operation is sent through control line 156 to block valve 158.
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Normal high load operation automatically varies nozzle area to maintain an optimum engine pressure ratio (EPR). An error signal representing fan damage is established by comparing the actual EPR to the predicted EPR. Compressor stalls are also monitored. In response to these signals a minimum nozzle area is set and modified. Automatic operation to hold EPR and afterburning is inhibited. Further signals representing satisfactory operation may reset the inhibiting action.
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PURPOSE OF THE INVENTION
The present invention relates to a device and a method that allow adjusting a surgical Instrument position more accurately and faster than with a conventional method. The scope of the invention is any surgical Instrument where the Instrument position is adjustable by screws, and tracked in real-time by a navigation system. The invention is an intraoperative surgical Device.
BACKGROUND OF THE INVENTION
It is known that some navigation systems are tracking instrument position during their position adjustment.
It is known that some instruments are adjusted by screws, such as cutting planes of cutting blocks for total knee replacement procedures.
Many devices use screws to adjust and finely tune the position of a surgical instrument. For instance, in U.S. Pat. No. 6,712,824, Millar uses a mechanism with three screws to adjust the plane position of a cutting guide for knee surgery, but the screws must be adjusted manually which takes time. Similar principles can be found in EP 1 444 957 by Cusick, or US 2006/0235290 by Gabriel. Moreover the mechanical architecture in those inventions is serial and it does not lock automatically to a given position when the screws are not turned, it is therefore necessary to lock the screws to a given position with an additional locking screw mechanism or to use additional pins in the bone to fix the cutting guide.
More complex architectures are using more than three screws in order to adjust cutting blocks. For instance, in EP 1 669 033, Lavallee uses a navigation system to adjust the position of several screws of a femoral cutting block but this process is not easy and it takes a long time.
The tracking technology of trackers and navigation systems is independent of the invention, provided that the trackers are tracked in real-time by the navigation system. It includes, but is not limited to optical active technology, with active infrared Light Emitting Diodes (LEDs) on trackers, optical passive technology (with passive retro-reflective markers on trackers), mechanical passive arms with encoders, accelerometers and gyrometers, or magnetic technology. Those tracking technologies are known as prior art of navigation systems for surgery.
Referring to FIG. 1 , the instrument 1 is any surgical instrument that has the following characteristics:
[A] The instrument 1 has a tracker 10 attached thereon so that it is tracked by the navigation system 2 . The navigation system 2 comprises a camera 20 and a computer 21 with a screen. [B] The instrument 1 is rigidly fixed to a solid 3 that is also tracked by the navigation system 2 . [C] The instrument has a fixed part 11 which is fixed to the solid 3 and a mobile part 12 which is mobile with respect to the fixed part 11 . [D] The position of the fixed part 11 with respect to the mobile part 12 can be adjusted by screws 13 . The number of screws is independent of the invention.
A screwdriver 7 is used to adjust the instrument position with respect to the solid 3 in a target position. The target position of the instrument is supposed to be selected by the surgeon or set to default values with respect to anatomical landmarks digitized with the navigation system. The target position is represented by a geometric relationship between the fixed part 11 of the instrument and its mobile part 12 . By trivial calibration, the target position can be represented equivalently to a geometric relationship between a tracker attached to the mobile part and a tracker attached to the fixed part or to the solid.
The problem is for the user to move several screws 13 independently to move the mobile part 12 until the geometric relationship between the mobile part tracker 10 and the solid tracker 30 matches within a very low tolerance limit such as for instance 0.5 mm and 0.2°.
The manual adjustment of individual screws 13 takes a long time and it is difficult to converge towards a solution.
To help this process, for any initial position of the screws 13 and mobile part 12 , the computer 21 of the navigation system 2 can calculate the necessary screw differential adjustments DSi, for each screw 13 i (where i is from 1 to N and N is the number of screws), which is necessary to bring the mobile part 12 in the target position. This is an easy calculation that only requires knowing the geometry of the screw placements with respect to the mobile and fixed parts and that is specific to each geometry. In a first step, the display of the navigation system can simply show the adjustments necessary DSi on each screw to the user such that the user follows the indications on the screen. While the screws 13 are manually adjusted, the values DSi are recalculated in real-time and the user can adjust the various screws accordingly.
However, this process remains long and complicated.
The present invention thus aims at providing an adjustment process that is short and simple in order to save intraoperative time.
BRIEF DESCRIPTION OF THE INVENTION
In order to make this process really fast and simple, the invention proposes to use a device which communicates with the computer such that placing the device in contact with the screws and using one of the automatic screw detection methods described below can generate an automated motion of the device to match the desired adjustment DSi.
One object of the invention is a device for adjusting the position of a surgical instrument with respect to a solid tracked by a navigation system, wherein the instrument comprises a fixed part that is rigidly fixed to the solid and a mobile part that is attached to the fixed part by screws, said device comprising:
a stem comprising a tip suited to the head of the screws, a motorized system for driving said stem in rotation, communication means with the navigation system, such that the navigation systems transmits to the motorized system the number of turns to apply to the stem to reach the target position of each screw.
For each adjustment screws of the instrument, the navigation system computes the number of turns and the rotation direction that needs to be applied. Then, by inserting the tip of the device in the screw's head and by pressing a button to activate the device, the motorized device turns automatically the screw until the screw reaches the target position. By applying this process for each adjustment screw, the instrument is adjusted more precisely and faster than with the conventional mechanical ancillaries or with existing navigation systems.
Advantageously, the device further comprises detection means for identifying which screw the tip of the device is in contact with, and the communication means of the device are able to transmit said identification information to the navigation system.
According to an embodiment of the invention, said detection means comprise a sliding stem able to slide inside the stem and a position sensor adapted to measure the displacement of the sliding stem with respect to the tip of the device.
According to another embodiment, the detection means comprise electrical connectors arranged at the tip of the device and an ohmmeter.
According to another embodiment, the detection means comprise a “Hall effect” sensor arranged in the tip of the device.
According to another embodiment, the detection means comprise an optical sensor, a first optical fiber and a second optical fiber, the first and second optical fibers being arranged inside the stem so as to respectively light the cavity of the screw head and bring the reflected light to said optical sensor.
According to another embodiment, the detection means comprise a tracker rigidly attached to the device.
Another object of the invention is a method of adjusting the position of a surgical instrument with respect to a solid tracked by a navigation system, wherein the instrument comprises a fixed part that is rigidly fixed to the solid and a mobile part that is attached to the fixed part by screws, comprising the following steps:
determining the position of the mobile part of the instrument with respect to the solid, comparing said determined position with respect to a target position, if said determined position is different from the target position, computing, for each screw of the instrument, the number of turns to apply in order to reach said target position, positioning the tip of the device as described above in each screw head, operating the motorized system of the device such that it applies to the stem the computed number of turns.
Another object of the invention is the device described above for use in a method comprising the steps of
determining the position of the mobile part of the instrument with respect to the solid, comparing said determined position with respect to a target position, if said determined position is different from the target position, computing, for each screw of the instrument, the number of turns to apply in order to reach said target position, positioning the tip of the device as described above in each screw head, operating the motorized system of the device such that it applies to the stem the computed number of turns.
Another object of the invention is a computer assisted surgical navigation system for adjusting the position of a surgical instrument computer assisted surgical navigation system for adjusting the position of a surgical instrument with respect to a solid, wherein the instrument comprises a fixed part that is rigidly fixed to the solid and a mobile part that is attached to the fixed parts by screws, the system comprising:
a first reference element applied to the solid that generates a first three-dimensional dynamic reference tracker, which is independently registered in the navigation system
a second reference element applied to mobile part of the surgical instrument that needs to be adjusted, that generates a second three-dimensional dynamic reference tracker, which is independently registered in the navigation system
the device as described above
wherein the number of turns and the rotation direction are determined for each screw by the navigation system, taking into account the current mobile part position, the target mobile part position, the design of the screws and the design of the instrument, and transmitted to the device by the communication means.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sequential view showing a conventional screwdriver positioned into the screws of the instrument.
FIG. 2 is an elevational view of the device according to the invention.
FIG. 3 is a partial sectional view of the device stem, device tip, and instrument screws, where the auto-detection of the screw is done by a mechanical solution.
FIG. 4 is a partial sectional view of the Device stem, Device tip, and Instrument Screws, where the auto-detection of the screw is done by an electrical solution.
FIG. 5 is a partial sectional view of the Device stem, Device tip, and Instrument Screws, where the auto-detection of the screw is done by a magnetic solution.
FIG. 6 is a partial sectional view of the Device stem, Device tip, and Instrument Screws, where the auto-detection of the screw is done by an optical solution.
FIG. 7 is a sequential view of the Device, the navigation system, and the Instrument, where the auto-detection of the screw is done by a tracking solution.
FIG. 8 illustrates a cutting slot which is adjusted by three screws assembled in a parallel architecture with respect with the basis fixed to the tibial bone.
FIG. 9 is a surgical procedure flow diagram, showing how the surgeon is supposed to interact with the navigation system to adjust the desired instrument position.
DESCRIPTION
The invention can be used for adjusting one planar instrument with three screws, or a linear guide with four screws, or a cutting block sliding on a planar surface with 2 screws, or a complete solid with at least six screws. Those numbers of screws relate to the number of degrees of freedom for each geometrical type of adjustable Instrument or guide.
The device and navigation system used in the present invention are similar to those presented in FIG. 1 . However, the device according to the invention is different from the conventional screwdriver and is illustrated on FIGS. 2 to 8 .
In one preferred embodiment, the surgical application is the total replacement of the knee joint; the solid 3 is the patient's tibia or the basis of the instrument fixed to the tibia, and the tracker 30 , rigidly fixed to the bone, allows the navigation system 2 to track the tibia; the instrument 1 is a cutting block on which a cutting plane 14 must be aligned with the desired target plane selected by the surgeon; the instrument mobile part position is adjustable by three screws; the position of the three screws determine a unique position of the cutting block with respect to the fixed part 11 . The cutting plane position is defined by a slope angle, a varus/valgus angle, and a cut thickness with respect to the tibia. The target position is entered into the navigation system by the surgeon or set to default values with respect to anatomical landmarks digitized by the surgeon with the navigation system. The goal of the device is then to adjust the position of the cutting block in the target position.
In one preferred embodiment, the surgical application is the total replacement of the knee joint; the solid 3 is the patient's femur or the basis of the instrument fixed to the femur, and the solid tracker 30 , rigidly fixed to the bone, allows the navigation system 2 to track the femur; the instrument 1 is a cutting block on which a cutting plane 14 must be aligned with the desired target plane selected by the surgeon; the Instrument Mobile Part position is adjustable by three screws; the position of the three screws determine a unique position of the cutting block with respect to the fixed part 11 . The plane position is defined by a slope angle, a varus/valgus angle, and a cut thickness with respect to the femur. The target position is entered into the navigation system by the surgeon or set to default values with respect to anatomical landmarks digitized by the surgeon with the navigation system. The goal of the device is then to adjust the position of the cutting block in the target position.
Device
As represented on FIG. 2 , the device 4 according to the invention is a motorized screwdriver that comprises a body or handle 40 , a stem 41 , a tip 42 , an optional button 43 that is activated by the user, and an encapsulated battery that brings enough power to rotate the screwdriver.
As better seen on FIG. 3 , the stem 41 is rotating with respect to the device body 40 thanks to a rolling system 44 . The rotation is controlled by a motorized system 45 . It must be noted that the devices illustrated on FIGS. 4 to 7 also comprise said rolling and motorized systems, although these features are not shown on these figures. Usually, a reduction ratio is used between the motor and the stem using standard gears so that one turn of the motor makes only 1/50 turn of the stem, which improves the stability and accuracy of the system.
The device is controlled by the computer 21 of the navigation system. The controlled parameters are: turn direction, number of turns, turn speed and turn acceleration. The number of turns and the direction are parameters given by the computer and transmitted through the wireless protocol to the device.
The device communicates with the computer through a wireless protocol, such as WIFI® or BLUETOOTH® or ZIGBEE®. In one preferred embodiment, the wireless communication is based on the Bluetooth communication protocol. Optionally, the communication can be also performed by standard wires with a standard wire and communication protocol such as USB®, ETHERNET®, IEEE 1394, RS232, or a proprietary wire and communication protocol, and in that case the power supply is also brought by a cable.
In a simple embodiment of the invention, the computer display indicates to the user the screw in which the screwdriver must be placed. When the user has placed the screwdriver in the head of the screw indicated on the screen, the user presses a button and the screwdriver moves the screw to the target position. The operation is repeated for each screw. If the user misses one screw the computer display shows which screw must be readjusted until the final position of the guide matches the target. For instance, the screw that has the most important number of turns to be accomplished is suggested to the user. Or the screw are always adjusted in the same order, starting by screw 1 , then 2 , until screw N and the process is iterated by skipping screws that already reached the target position with a predefined limit.
Automatic Detection of the Screw ID
Advantageously, the device comprises detection means for determining the identification of the screw the tip is in contact with. Depending on the various embodiments disclosed below, each screw possesses within the navigation system identification (ID) means to distinguish it from the others.
In one preferred embodiment, illustrated on FIG. 3 , the device detects which screw the tip is in contact with by a mechanical solution. To that end, a thin rigid mechanical stem 50 is sliding inside the device stem 41 . By using the rigid mechanical link between the stem 50 , the body 54 , and the position cursor 51 , the contact between the sliding stem 50 and the screw's head cavity 131 determines the value of the position sensor 52 . When the tip is not inserted into the screw's head 130 , a spring 53 places the position sensor 52 at its default position. When the tip is in the screw's head 130 , the position sensor 52 measures the depth d of the screw's head cavity 131 . This depth is measured and transmitted to the navigation system 2 by the wireless communication. Each screw's head cavity 131 has a different depth d, so that the position sensor delivers a different value for each screw, allowing the navigation system to know which screw the device is about to activate.
In another embodiment, illustrated on FIG. 4 , the device detects which screw the tip is in contact with by an electrical solution. In this case, a resistance 60 is inserted into the screw's head 130 linked by two electrical wires 61 , 62 respectively to two connectors 63 , 64 that are on the bottom surface of the screw's head. In the device stem and tip are inserted two electrical wires 65 , 66 that are respectively connected to two connectors 67 and 68 that are on the extremity of the device tip. When the tip is in the screw's head 130 , the connectors 63 and 67 are in contact, as well as the connectors 64 and 68 . It allows the device to measure the tension thanks to an ohmmeter 69 . This tension is measured and transmitted to the navigation system by the wireless communication. Each screw's head has a different resistance value r, so that the ohmmeter 69 delivers a different value for each screw, allowing the navigation system to know which screw the device is about to activate.
In another embodiment, shown on FIG. 5 , the device detects which screw the tip is in contact with by a magnetic solution. A magnet 70 is inserted into the screw's head 130 . A “Hall effect” sensor 71 is inserted into the device tip that delivers a tension that is dependent of the distance between the magnet 70 and the sensor 71 . This tension is measured and transmitted to the navigation system by the wireless communication. Each screw's head has the same magnet but inserted at a different depth d, so that the sensor 71 delivers a different tension for each screw, allowing the navigation system to know which screw the device is about to activate.
In another embodiment, illustrated on FIG. 6 , the device detects which screw the tip is in contact with by an optical solution. To that end, a cavity 131 is inserted into the screw's head 130 . The bottom 132 of the cavity 131 is painted with a uniform color or with a pattern such as a bar code. A first optical fiber 80 carries light 81 from the device stem to the cavity 131 , in order to light the cavity 131 . A second optical fiber 82 carries the light 83 from the cavity to the device stem and then to an optical sensor such as a micro camera (not shown). The image delivered by the second optical fiber 82 is transmitted to the navigation system by the wireless communication. Each bottom 132 of screw's head cavity 131 has a different color or different pattern, allowing the navigation system to know which screw the device is about to activate.
In another embodiment, shown on FIG. 7 , the device detects which screw the tip is in contact with by a tracking solution. A tracker 90 is rigidly fixed to the device 4 . One knows by design the device tip position in the device tracker 90 coordinates system. One knows by design the screw's head position in the instrument tracker 10 coordinates system. Then, once the device tip is inserted into a screw's head, the navigation system 2 can determine which screw's head the device tip is inserted in, allowing the navigation system to know which screw the device is about to activate. If the accuracy of the navigation system is not sufficient, it can be compensated by adding a simple mechanical contact sensor that detects that the tip is in contact with the screw head.
In another embodiment (not illustrated here), the device detects which screw the tip is in contact with by a software solution: before the device activation, the navigation system records the position of the Instrument, called the initial position. When the user presses the activation button, the device turns as first step the stem in a constant known direction (e.g. clockwise). The navigation system then tracks the movement of the mobile part of the Instrument. By taking into account the design of the screw, the design of the Instrument, the given rotation direction and the number of turns that were applied, one can determine the unique screw that brought the instrument to this current position. Then, once the screw ID is determined by this first stem actuation, the device can then rotate the stem in the correct rotation direction with the correct number of turns to reach the target position.
Parallel Architecture
In one preferred embodiment, illustrated on FIG. 8 , the device is an adjustable cutting block for bone cuts with a parallel mechanical architecture made of three screws 13 between the fixed part 11 and the mobile part 12 . To allow for various orientations of the cutting plane 14 , at least two screws 13 have some small translational degrees of freedom parallel to the cutting plane at the level of their insertion in the block 12 . It is also possible to add small ball-and-socket joints to add more flexibility to the device. This architecture is not reversible since a normal force applied to the mobile part does not move it. Therefore, with well manufactured mechanical components with high level of tolerance, the device is very stable except small motions in the plane which do not affect the accuracy of eth plane itself. In most cases, it is not necessary to fix the mobile part to the bone before making a cut using cutting plane 14 .
Surgical Procedure Flow Diagram
The surgical procedure flow diagram is composed of steps [A], [B], [C], [D] and [E] that are described in FIG. 9 .
[A] The computer 21 computes the current position of the instrument mobile part 12 with respect to the solid 3 thanks to the instrument tracker 10 , the solid tracker 30 , and the localizer system ( 14 ) [B] If the current position is the target position then the procedure exits. [C] If the target position is not reached, then for each screw 13 i , where i is equal to 1, 2 or 3, the computer computes the unique number of turns Ti that needs to be applied on 13 i , so that the mobile part 12 reaches the target position. Ti is positive if the rotation direction is clockwise and negative if the rotation direction is counter-clockwise. For that computation, the computers needs to know the target position of the instrument, which is selected by the surgeon, the screws parameters (diameter, thread length, thread thickness), which are known by design, the screws positions on the Instrument, which are known by design. [D] The navigation system instructs the user which screw needs to be activated:
i. In one preferred embodiment, the user is instructed to place the device tip 42 on a given screw's head. The computer displays on the screen which screw's head the device tip 42 must be placed on. In one preferred embodiment, each screw's head has a unique color, and the computer displays the color of the screw on the screen. In another embodiment, each screw's head is labeled with a unique number (such as 1, 2, 3), and the computer displays the number of the screw on the screen. In another embodiment, each screw's head is labeled with a unique letter (such as A, B, C), and the computer displays the letter of the screw on the screen. Screws can be also differentiated simply by their position on the instrument or by their shape. The user needs to follow the screws order displayed by the computer. ii. In another preferred embodiment, the user is instructed to place the device tip 42 on a given screw's head. Each screw's head has a unique characteristic such as color, or number, or letter as detailed in (i). The computer computes on which screw's head the device tip 42 must be placed on. The information is then transferred from the computer to the device by the wireless communication protocol. The device then instructs the user by displaying the information on itself, preferably on the top of the handle of the screwdriver. It can be by lighting some colored LEDs if screws are identified by a color, by lighting a letter if screws are identified by a letter, or by lighting a number if screws are identified by a number. The user needs to follow the screws order displayed by the computer or displayed on the handle of the screwdriver. iii. In another preferred embodiment, the user is not instructed to place the device tip 42 on a particular screw's head. The user can independently choose any screw's head, whatever the order is. The device detects when the tip is in contact or not of the screw's head, and detects which screw it is in contact with, and communicates the screw ID to the navigation system by the wireless communication protocol such that the adjustment necessary for that particular screw is known.
[E] Then the user presses the button 43 to activate the device. If the device is used with automated detection of contact and identification of screw head, pressing a button is not necessary and the device is activated automatically. The device stem 41 then turns the given number of turns Ti that was determined by the computer to reach the target position of the instrument. Once the device stem 41 has turned the desired number of turns Ti, the stem rotation stops, instructing the user that the target position for the screw 13 i has been reached. Optionally, the navigation system 2 can check that the mobile part 12 has reached the desired position for that particular screw and if it is not the case, send an updated command to the screwdriver to add more portions of turn in order to adjust it accordingly and this process can be repeated until the position of the mobile part 12 has reached the desired position within a given arbitrary accuracy such as 0.2 mm for instance, which is done like a standard servoing mechanism. Then the instrument position is updated and the process goes to step [A] for setting other screws to the desired positions. The global process is iterated until all screws have reached their desired position such that the mobile part is now in its final target position for all desired degrees of freedom.
To reach a target screw position, there exists many possible methods to control the motors to optimize the speed of the process:
A first method consists in measuring the position of the mobile part before the screw has reached its final position using the navigation system and iterating the command on the motors that takes into account the measured position and the target position. Standard control commands can be used to optimize the speed and convergence of such process, for instance using well known Proportional Integral Derivative (PID) commands. Another method consists in turning the motor in the right direction with an increasing speed and then decreasing speed when the motors come close to the expected position and finally stopping the motor when it has a very low speed so that the measurement taken with the navigation system can be done with averaging to reinforce accuracy and the time delay to stop the device is compliant because of low speed. There exists many additional ways of optimizing the command by using the measurements of the final position of the mobile part using navigation system or by using the measurements of the motor controller that often provide the number of turns performed by the motor, with a division of such number by mechanical reduction. It is also possible to combine both measurements in real time in order to optimize and stabilize the convergence towards the target position.
ADVANTAGES OF THE INVENTION
The main advantage of the invention is to save intraoperative time. In a preferred embodiment the application is the adjustment of femoral distal cutting block and tibial cutting block for total knee replacement procedures. The conventional method with or without the use of a navigation system for aligning a cutting block is to use a set of several mechanical instruments, and to follow many steps that involve a lot of different mechanical instruments, which requires several minutes. The use of the invention reduces this operative time to a few seconds.
A second advantage is that the adjustment of the cutting block is automated and the user does not need to manage and think to complex iterations of several adjustments.
The advantage of the parallel architecture with 3 screws according to the present invention is that it continuously locks to its position in a non reversible way. The drawback of this architecture could be that the screws are not easy to adjust to their target value. However, the use of a motorized screwdriver to adjust the screws to their final position makes it possible to get the maximal benefit from the parallel architecture.
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The present invention relates to a device for adjusting the position of a surgical instrument ( 1 ) with respect to a solid ( 3 ) tracked by a navigation system ( 2 ), wherein the instrument ( 1 ) comprises a fixed part ( 11 ) that is rigidly fixed to the solid ( 3 ) and a mobile part ( 12 ) that is attached to the fixed part by screws ( 13 ), the device ( 4 ) comprising:
a stem ( 41 ) comprising a tip ( 42 ) suited to the head ( 130 ) of the screws ( 13 ), a motorized system ( 45 ) for driving the stem ( 41 ) in rotation, a communication device with the navigation system ( 2 ), such that the navigation systems ( 2 ) transmits to the motorized system ( 45 ) the number of turns to apply to the stem ( 41 ) to reach the target position of each screw ( 13 ).
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the field of archery.
More particularly, the present invention relates to an item of archery equipment generally referred to as a compound bow.
In a further and more specific aspect, the present invention concerns improvements to materially reduce the effects of induced torsion in a compound bow limb.
2. Description of the Prior Art
Archery, the art of shooting with bows and arrows, is an anchient practice which has been continued to the present time. The traditional bow was merely a strip of flexible wood having a string or cord extending between the tips. Evolution over the centuries has resulted in the compound bow, familiar to modern archers.
Originally, archery equipment was exceedingly simple 2nd highly ineffective. The bow limbs, the portions of the bow extending in either direction from the handle section to the respective tips, were not torsionally balanced. Accordingly, in a condition referred to as "system torque", the tips of the bow pulled unequally upon the string, imparting erratic flight to the arrow.
Another pronounced problem with early equipment was the phenomenon known as "archers' paradox" which concerned the attempt of the arrow to have both ends travel in the same straight line to the target. The problem arose as a result of the rear tip of the arrow being propelled directly toward the target by the string which moves in a plane bisecting the center line of the bow and perpendicular to the target. The forward tip of the arrow, however, extends laterally from the plane of the string as a result of the width of the bow around which the arrow must pass.
Over the years, bows remained relatively unchanged. With the advent of modern materials and laminating technology, bow limbs were greatly improved. The new laminated structures, usually wood between layers of fiberglass, were of improved strength and balance. Grip sections incorporating relatively shallow "sight windows" also appeared. "Archers' paradox", though not eliminated, was reduced and made more reliably predictable.
In very recent times, there emerged the present-day "compound bow" consisting of extremely stout bow limbs secured to a central section or "handle riser". Generally fabricated of metal, the central section was of sufficient strength to accommodate a "sight window" of ample depth to eliminate the anchient "archers' paradox". A system of string, now more appropriately called cable, extending over pulleys at the ends of bow limbs allowed the average archer to draw a bow approximately twice as powerful as had previously been the case.
While providing numerous advantages and correcting various previous problems, the compound bow did not represent perfection. Especially notable was the twist or torsion introduced into the bow limbs as a result of the unbalanced loading of the pulleys. Characterized as "limb/pulley torque", it has remained a major cause of inferior arrow flight.
Typically, the compound bow limb is of comparatively uniform width terminating with a relatively broad tip which is bifurcated to form a pair of tip sections. A two-groove pulley and a single-groove roller are carried upon an axle extending between each of the tip sections. The roller, usually substantially smaller than the pulley, functions as a "tieoff buss". Three segments of a single cable extend between the tips of the bow.
A first segment of the cable extends between outboard grooves of the pulley. The other two segments extend between the inboard groove of the pulley and the roller at the opposite tip. Termed the "bow string", the first section is generally parallel to and spaced from the longitudinal axis of the bow. The other two sections are oblique to the longitudinal axis, crossing at the approximate midpoint of the bow. The ends of the latter two segments are terminated or tied off at the roller.
A primary recommendation of the compound bow is the mechanical advantage provided by the arrangement of cables and pulleys. The force with which the archer is required to hold when the bow is fully drawn is substantially less than the force by which the arrow is propelled. The advantage to the archer is further enhanced by the use of eccentric or off-center mounted pulleys. A usual arrangement provides approximately a 2:1 mechanical advantage.
There are, however, counteracting disadvantages. As the bow is drawn, the force on the bow string is approximately one-half the force on the other strings or cable segments. A force of corresponding magnitude is applied to each of the corresponding pulley grooves. In a bow capable of propelling an arrow with sixty pounds thrust, for example, thirty pounds of pressure is applied to the outboard groove of each of the eccentric pulleys. Correspondingly, sixty pounds of pressure is applied to the roller or "tieoff buss" and to each of the inboard grooves of each of the eccentric pulleys.
The placement of the pulley is rather rigidly defined. Ample strength must be maintained in the long tip sections to support the load transmitted through the pulleys to the axles and ultimately to the tip sections. It has been conventional procedure since the advent of the compound bow to align the pulleys in juxtaposition on the longitudinal axis of the limb between tip sections of substantially equal proportions. The forces absorbed by the limb, however, are asymmetrical or unbalanced relative to the longitudinal axis of the bow.
Consider, for purposes of illustration, a system in which the inboard groove of the eccentric pulley is in approximate alignment with the longitudinal axis of the bow limb. The outboard groove of the eccentric pulley and the groove of the smaller roller are substantially equally spaced on opposite sides thereof. Accordingly, unequal force is applied to the tip sections of the bow limb.
As the bow is drawn the tips move rearwardly, deflecting the limbs along the plane of movement of the bow string. Concurrently, the tip sections supporting the greater force move laterally, introducing twist or torsion into the bow limbs. Both movements store energy within the bow limbs.
Upon release of the bow string, the energy previously stored in the bow limbs is unleashed as the limbs straighten and return to normal or unstressed configuration. The energy, transmitted through the bow string, is the propelling force for the arrow. In the conventional compound bow, the propelling force includes a linear component directed toward the target as a result of the rearward deflection of the limbs and a torque component as a result of the twisting motion of the tips. The speed and direction of the arrow is the resultant of the components of the force.
It is well recognized by those skilled in the art that the arrow is whipped sideways, and therefore inaccurately, in response to the torque. It can be demonstrated that one-eighth of one inch, a realistic measurement depending upon the weight of the arrow, of twist of the pulleys can result in as much as ten inches of lateral dispersion of the arrow at forty yards.
Limb/pulley torque is responsible for additional undesirable results. Frequent longitudinal twisting accelerates fatigue and breakage of bow limbs. Also, the cable can slip from the grooves of the pulley which is tilted, thereby unstringing the bow. Further, arrow efficiency during downrange flight is adversly affected, reducing speed and penetration.
The prior art has proposed various solutions to the foregoing problems, including altered arrow design and various attachments and paraphernalia for bows. None of the suggested remedies has provided a satisfactory resolution. It would be highly advantageous, therefore, to remedy the foregoing and other inherent problems in the prior art.
Accordingly, it is an object of the present invention to provide improvements in archery equipment.
Another object of the invention is the provision of an improved compound bow.
And another object of the invention is to provide an improved bow limb of the type used in connection with compound bows.
Still another object of this invention is the provision of means which materially reduce the effects of limb/pulley torque.
Yet another object of the immediate invention is to provide means whereby the resultant propelling force of the bow string is substantially directed toward the target or point of aim.
Still another object of the invention is the provision of means to eliminate twist in a bow limb.
A further object of the instant invention is to provide a balanced bow/limb system.
And a further object of the invention is the provision of an inherently balanced system without requiring attachments or encumbrances.
Still a further object of this invention is to provide an improved bow limb which is less susceptible to fatiguing and breaking.
And still a further object of the instant invention is the provision of improvements of the foregoing character which are relatively simple and inexpensive to effect.
SUMMARY OF THE INVENTION
Briefly, to achieve the desired objects of the instant invention in accordance with a preferred embodiment thereof, there is provided in a compound bow employing a two-adjacent element pulley/cam structure and a tieoff element at each bow end in connection with the cable which extends from a first tieoff element at each bow end to a first element of the pulley/cam structure at the second end, are improvements which the restoring force stored in each end of the compound bow, when drawn, is comprised of unequal components contributed by the deflected bow material the respective two sides about the bow axis and the difference between the unequal components being predetermined to exert a torsional force on the bow end which balances a torsional force imparted to the bow by the summation of forces applied to the pulley/cam structure and the tieoff element by the cable, thereby eliminating limb/pulley torque.
In accordance with a more specific embodiment, the unequal components are obtained by employing unequal cross sectional areas in the material of the respective two sides about the bow longitudinal axis along at least a portional length of the compound bow. In accordance with an embodiment of the invention, this is achieved by providing a bow limb which is generally trapezoidal in cross-section.
In accordance with another embodiment of the invention, there is provided a unitary pulley and tieoff element which is supported between equal components. The spacing between the grooves and the unitary pulley is such that the resultant of the unequal components is along the approximate lateral center of the unitary pulley structure.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and further and more specific objects and advantages of the instant invention will become readily apparent to those skilled in the art from the following detailed description of preferred embodiments thereof taken in conjuction with the drawings in which:
FIG. 1 is a broken rear elevational view of the upper portion of a conventional prior art compound bow herein chosen for purposes of representative illustration;
FIG. 2 is a horizontal sectional view taken along the line 2--2 of FIG. 1;
FIG. 3 is a horizontal sectional view taken along the line 3--3 of FIG. 1;
FIG. 4 is a view generally corresponding to the view of FIG. 1 and illustrating another typical prior art device;
FIG. 5 is a horizontal sectional view taken along the line 5--5 of FIG. 4;
FIG. 6 is a view generally corresponding to the views of FIGS. 3 and 5 but illustrating an improved bow limb constructed in accordance with the teachings of the instant invention;
FIG. 7 is an elevational view of the tip and terminal portion of another bow limb embodying the improvements of the instant invention;
FIG. 8 is a vertical section view taken along the line 9--9 of FIG. 7;
FIG. 9 is a view generally corresponding to the view of FIG. 7 and showing yet another embodiment of the instant invention;
FIG. 10 is a top plan view of the embodiment of FIG. 9;
FIG. 11 is a view generally corresponding to the view of FIG. 5 and showing yet another means of providing an improved bow limb in accordance with the teachings of the instant invention; and
FIG. 12 is a horizontal sectional view, generally corresponding to the view of FIG. 2, and showing yet another improved bow limb of the instant invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to the drawings, in which like reference characters indicate corresponding elements throughout the several views, attention is first directed to FIG. 1 which illustrates a typical prior art compound bow, generally designated by the reference character 20, including central section or handle riser 22 and oppositely extending bow limbs 23. Each bow limb 23 (only the upper one being illustrated herein) includes a fixed end 24 coupled to handle riser 22 and a tip end 25. In the immediate embodiment chosen for purposes of illustration, each bow limb 23 has a tip end 25 which is narrower than the fixed end 24 as evidenced by edges 27 and 28 which tend to converge in a direction toward tip end 25. As seen in FIG. 2, however, each bow limb 23 has a rectangular cross-section of relatively constant proportions. It is noted that the edges 27 and 28 are parallel as are the front side 29 and the rear side 30.
The longitudinal axis or center line of bow 20 is represented by the broken line A. Hand grip 32, that portion of handle riser 22 held by the hand of the archer, is generally aligned along axis A. Cut-out 33, the sight window through which the arrow passes, resides above hand grip 32. Bow limbs 23 are symmetrical about axis A.
Slot 34, defined by substantially parallel sides 35 and 37, is formed into bow limb 23 from tip end 25. Slot 34 bifurcates the terminal tip portion of bow limb 23 creating tip sections 38 and 39 of correspondingly uniform cross-section. Slot 34 functions as a housing for the pulley assembly.
Axle 40 supported by tip sections 38 and 39 extends through slot 34. Axle 40 extends beyond edges 27 and 28 and is retained by keepers 42. An eccentric pulley 43 having inboard groove 44 and outboard groove 45 is rotatably supported upon axle 40. A smaller tieoff roller 47 having groove 48 is also rotatably supported upon axle 40 adjacent the inboard groove side of larger pulley 43. The pulleys 43 and 47, variously referred to as cams, reside in juxtaposition having a total width approximating the distance between sides 35 and 37 of slot 34. Accordingly, there is no appreciable lateral movement of the pulleys upon the axle.
As will be appreciated by those skilled in the art, a mirror image arrangement of pulleys and associated grooves is carried by the bow limb not illustrated but extending in the opposite direction from handle riser 22. A single cable 49 continuously embraces the several grooves. A first segment 50 of cable 49 extends between corresponding outboard grooves 45. A second segment 52 extends between groove 44 at the tip of one bow limb to the groove 48 at the other bow limb. Similarly, a third segment 53 extends between the remaining groove 44 and the groove 48 at the first end. The cable is usually transferred between the grooves 44 and 45 by an opening, such as a slot or aperture, extending laterally of pulley 43. Segment 50, referred to as the bow string, is generally parallel to the longitudinal axis A of bow 20. Segment 52 and 53 are oblique to longitudinal axis A, normally crossing at the approximate midpoint of the bow. The arrow is propelled by the bow string segment 50. To provide substantial clearance for the fletchings at the rear of the arrow, segments 52 and 53 are pulled laterally and retained in the spaced relationship from segment 50 by cable guard 54 which projects rearwardly from handle riser 22, as further viewed in FIG. 3, a distance sufficient to accommodate the maximum displacement of cable segment 52 and 53.
As bow string 50 is drawn rearwardly by the archer, the force induced into cable 49, acting through the pulley or cam assemblies at the opposite ends of the bow, tend to move the tip ends 25 together. Resultingly, each bow limb 23 is flexed and stressed in a rearwardly directed curve storing the energy which will subsequently supply a component of the propelling force for the arrow. As will be readily understood by those skilled in the art and consistant with the primary advantage of a compound bow, the tension in cable 49 is not equalized throughout the several segments. Correspondingly, the several pulley grooves are subjected to unequal force.
A force of given magnitude is applied to outboard groove 45 of pulley 43. A force of approximately twice the given magnitude is applied to the inboard groove 44 of the pulley 43 with an approximately equal force being applied to groove 48 of the smaller pulley 47. In a sixty pound bow, for example, sixty pounds of force is applied to the grooves 48 and 44 while thirty pounds of force is applied to the groove 45.
In the illustrative typical bow 20, groove 44 is aligned along the longitudinal axis A. As seen with further clarity in FIG. 3, grooves 48 and 45 are laterally displaced from the longitudinal axis A. Groove 45 is offset to the right a distance designated B. Groove 48 is offset to the left a distance designated C. For purposes of explanation, the force transmitted to groove 45 can be given the value F. The force exerted upon grooves 44 and 48 is, correspondingly, 2F.
Torque, as is well-known, is a function of distance and force. Since groove 44 is aligned upon the longitudinal axis, the distance component is zero (0) resulting in a torque calculation of (0)×(2F). The torque exerted upon bow limb 23 through groove 45 is given by the notation (F)×(B). Similarly, the force exerted upon bow limb 23 through groove 48 is given by the notation (2F)×(C). In the immediate case, the distance B is equal to the distance C. Therefore, twice as much torque is applied to tip section 39 as to tip section 38.
Ideally, bow string 50 moves through a plane which is parallel to the longitudinal axis of the bow and perpendicular to the target or point of aim. This assumes a balanced load upon the bow limb 23 as the edges 27 and 28 move in unison through congruent curves. In actual practice, however, due to the greater force transmitted through tip section 39, the curve of edge 28 is more severe than the curve of edge 27. Accordingly, torsion is induced into bow limb 23 in the general direction of the arrowed line D. In response thereto, bow string 50 moves through a plane which is oblique to the line of sight or the previously described plane perpendicular to the target.
The arrow is subject to the resultant force stored in bow limb 23. It is apparent from the foregoing explanation that the arrow propelling force includes a first component directed along the plane perpendicular to the target and a second torsional force which is oblique to the plane perpendicular to the target. Empirical observation has shown that, in a conventional sixty pound compound bow, the limb may twist as much as one-eighth of one inch as a result of the torsional forces. This can be responsible for as much as ten inches of lateral dispersion of the arrow at forty yards.
FIG. 4 illustrates another configuration of conventional prior art compound bows generally designated by the reference character 60. In general similarity to bow 20, bow 60 includes handle riser 62 having hand grip 63, a sight window 64 and oppositely extending bow limbs 65 each having fixed ends 67 and tip ends 68. Slot 69 extending inwardly from tip end 68 divides the terminal portion of bow limb 65 into tip sections 70 and 72. In order to accommodate a wider slot 69, the edges 73 and 74 of bow limb 65 are substantially parallel.
Analogous to the previously described prior art bow, the immediate embodiment includes a pulley assembly including eccentric pulley 75 and smaller tieoff roller 77 rotatably carried upon axle 78 supported by the equal strength tip sections 70 and 72. Pulley 75, like the previously described counterpart 43, includes outboard groove 79 and inboard groove 80. Groove 82 is formed in roller 77. A greater distance, however, exists between the grooves of the larger pulley. A similar bow limb carrying a mirror image pulley assembly (not herein specifically illustrated) extends in the opposite direction from handle riser 62.
Cable 83 communicates between the two pulley assemblies. Bow string 84 extends between corresponding grooves 79. Cable segment 85 extends between a groove 80 and the groove 82 at the opposite end thereof. Segment 87 extends between the remaining grooves 80 and 82. The greater distance between grooves 79 and 78 is for the express purpose of providing sufficient lateral separation between bow string 84 and segments 85 and 87 to accommodate the fletching of the arrow without resorting to extraneous means such as cable guard 54.
The longitudinal axis or center line of bow 60 is represented by broken line F. As seen with greater clarity in FIG. 5, grooves 79, 80, and 82 are offset from longitudinal axis F by the distances G, H, and I respectively. Grooves 80 and 82 are offset to the same side which is opposite the side to which groove 79 is offset. As previously described, the force of given magnitude is applied to groove 79. A force of twice the given magnitude is applied to each of the grooves 80 and 82.
It is apparent from the foregoing that torsional forces are applied directly to the tip sections 70 and 72 which are transmitted to bow limb 65. The torsional force supported by tip section section 70 is equal to (F)×(G). A torsional force absorbed by tip section 72 is equal to the sum of (2F)×(H) and (2F)×(I). It is noted that the distance H is less than the distance G and that the distance I is greater than the distance G. Accordingly, torsional force in the direction of the previously described arrowed line D with corresponding results is applied to each of the bow limbs 65.
Attention is now directed to FIG. 6 which illustrates an improved bow limb constructed in accordance with the teachings of the instant invention and generally designated by the reference character 90. In general similarity to conventional prior art bow limbs, bow limb 90 includes front face 92, rear face 93, and edges 94 and 95. Slot 97 having lateral sides 98 and 99 bifurcates the terminal portion of the tip end into tip sections 100 and 102. A pulley assembly including pulley 103 and tieoff roller 104 is rotatably supported upon axle 105 within slot 98. The terminal portions of axle 105 are supported by tip sections 100 and 102. Larger pulley 103 carries outboard groove 107 and inboard groove 108 while groove 109 is carried by tieoff roller 104.
The longitudinal axis or center line of bow limb 90 is represented by the broken line J. For arbitrary purposes of illustration and direct comparison to previously described prior art bow limb 20, inboard groove 108 of larger pulley 103 is considered to be aligned along the longitudinal axis J. As previously set forth, the center line of groove 107 resides a distance B from the longitudinal axis while groove 109 resides a distance C from the center line. The distances B and C extend on opposite sides of the center line. Also as previously noted groove 109 is subjected to a force having twice the magnitude of the force acting upon groove 107. Assuming the distances B and C to be equal, the force upon that portion of the bow residing between the longitudinal axis and the edge 94, the left hand side in the immediate illustration, is twice the load imposed upon the right hand side of the illustration, or that portion of bow limb 90 residing between the longitudinal axis and edge 95. The resultant is a twisting or torsional force in the direction of arrowed line D.
To nullify the effects of the non-uniform or unbalanced loading between edges 94 and 95, bow limb 90 is configured to have greater cross sectional area between the longitudinal axis and edge 94 than between the longitudinal axis and edge 95. While this configuration may assume various specific shapes bounded by a selected combination of straight and curved lines, as will be appreciated by those skilled in the art, a cross-section defined by four substantially straight lines, such as a truncated triangle, a trapezium or a trapesoid, are prefaced for purposes of manufacture. For purposes of clarity of illustration and ease of understanding, the form of a trapezoid has been chosen. Edges 94 and 95 are substantially parallel. Front face 92 and rear face 93 are convergent in a direction toward edge 95 away from the heavier loaded left side of the bow limb. Accordingly, tip section 102 and a portion of bow limb 90 adjacent edge 94 is more resistant to bending. The greater resistance to bending is directly proportional to the unbalanced load. Assuming bow limb 90 to be fabricated of material of uniform strength, the angle between front face 92 and rear face 93 is calculated to yield a configuration whereby the force applied to a first side of the bow limb times the cross-sectional area of the second side equals the force applied to the second side times the cross-sectional area of the first side.
In the embodiment of the invention illustrated in FIG. 6, the bow string is sufficiently close to the other cable segments as to require means, such as cable guard 54, to provide sufficient room for clearance of the arrow fletchings. An alternate bow limb, constructed in accordance with the teachings of the instant invention generally designated by the reference character 110 as illustrated in FIGS. 7 and 8 provides ample clearance between the bow string and the other cable segments. In general similarity to the previously described embodiment, bow limb 110 is generally trapezoidal in cross-section having parallel edges 112 and 113 and angularly disposed front face 114 and rear face 115 which converge in a direction toward edge 113. Axle 117 extends through bow limb 110 proximate tip end 118. Eccentric pulley 119 having an outboard groove 120 and inboard groove 122 is rotatably supported upon axle 117 outboard of edge 112. Smaller tieoff roller 123 having groove 124 is carried upon axle 117 outboard of edge 113. Since the clearance for the arrow fletchings does not require a separation of the pulleys equal to the full width of the bow limb, the terminal portion of bow limb 110 adjacent tip end 118 may be narrowed by recesses 125 and 127 along edges 112 and 113, respectively.
The center line or longitudinal axis of bow limb 110 is represented by the broken line L. Grooves 120 and 122 are offset to one side of axis L by distances represented as M and N, respectively. Groove 124 is offset to the other side by a distance represented as O. An equal force is applied to groove 122 and to groove 124, which force is of twice the magnitude of the force applied to groove 120. The angle between front face 114 and rear face 115 necessary to nullify the torsional effects and ensure uniform bending across bow limb 110 is calculated as previously described in connection with FIG. 6. Similarly, the trapezoidal cross-section tapers to a rectangular cross-section at an intermediate point of the bow limb.
The foregoing embodiments of the instant invention assume that the loading upon a bow limb is inherently unbalanced as a result of conventional pulley configuration. Remedy is provided in the form of improved bow limbs 90 and 110. Also provided by the instant invention is an improved bow limb which is inherently balanced as a result of redistribution of the forces acting upon the bow limb.
Referring now to FIGS. 9 and 10 there is seen an improved bow limb embodying the teachings of the instant invention and generally designated by the reference character 130. Bow limb 130, which is generally rectangular in cross-section, includes front face 132, rear face 133, edges 134 and 135, and tip end 137. The terminal portion of bow limb 130 is narrowed by recess 138 extending inwardly from tip end 137 and edge 134.
Axle 139 extends laterally through bow limb 130 proximate tip end 137. Eccentric pulley 140 having outboard groove 142 and inboard groove 143 is supported upon axle 139 to substantially reside within recess 138. Smaller tieoff roller 144 having groove 145 is carried by axle 139 adjacent edge 135.
The longitudinal axis or central line of bow limb 130 is represented by the broken line designated by the reference character P. As previously described, the bow limb is subjected to various forces which are applied to the several pulley grooves. A force of magnitute X is applied to the groove 142. A force having a magnitude 2X is applied to groove 143 and groove 145. The resultant of the forces applied to grooves 142 and 143 is a force of 3X at a distance Q from longitudinal axis P in a direction toward edge 134. The force 2X applied to groove 145 is at a distance R from axis P in a direction toward edge 135. Balance of the bow limb, i.e., equalization of potential torque on either side of the longitudinal axis P, is achieved in accordance with the equation (2F)×(R)=(3F)×(Q). The formula becomes an equation when the distance R is one and one-half times the distance Q. Similarly, bow limb 130 achieves inherent balance when the recess 138 is of sufficient depth that the pulley 140 may be mounted upon axle 139 to achieve the relative ratio between distance Q and R. The remaining component of the terminal portion of bow limb 130, after being narrowed by recess 138, functions as spacer means between pulley 140 and roller 144 to insure or maintain the desired distance.
It is also a teaching of the instant invention that the terminal portion of bow limb 130 not be narrowed by recess 138 and pulley 140 reside outboard of edge 134. Accordingly, the length of axle 139 is extended and the spacer means be expanded to include an element residing intermediate roller 144 and edge 135.
FIG. 11 illustrates another embodiment of the invention generally designated by the reference character 150 incorporating a pulley arrangement specially devised to provide inherent balance. Bow limb 150 which includes front face 152, rear face 153 and edges 154 and 155, has a terminal portion adjacent the tip end which is bifurcated by slot 157 to create tip sections 158 and 159 of equal cross-section and comparative strength and rigidity.
Unitary pulley assembly 160 is supported by axle 162 to reside within slot 157. Pulley assembly 160 includes eccentric pulley 163 and tieoff roller 164 integrally carried at opposite ends of hub 165. Hub 165, which functions as spacer means may be affixed to pulley 163 and roller 164 by various well known mechanical or adhesive expediencies. Alternatively, the assembly 160 may be cast or molded as an integral unit.
Consistant with the previously described pulley assemblies, pulley 163 includes outboard groove 167 and inboard groove 168 while tieoff roller 164 carries groove 169. The forces acting upon grooves 167, 168, and 169 are analogous to the previously described forces acting upon groove 142, 143, and 145, respectively, of the embodiment in FIGS. 9 and 10, The relative distances from the center line of bow limb 150 to achieve inherent balance are calculated as previously described in connection with the embodiment generally designated by reference character 130.
Turning now to FIG. 12 there is seen yet another improved bow limb of the instant invention, generally designated by the reference character 170 which, being generally rectangular in cross-section, includes front face 172, rear face 173, and edges 174 and 175. A plurality of longitudinally extending alternating grooves 177 and ribs 178 are formed in rear face 173. Empirical observation, utilizing a bow limb so constructed, indicates that the immediate configuration serves to reduce undesirable torsion. It has been determined that in a bow limb having a width of two inches, a plurality of grooves each apporximately sixty thousandths of an inch wide by ten thousandths of an inch deep and spaced sixty thousandths of an inch apart, yields satisfactory results. Preferably, the grooves and ribs commence proximate the tip of the limb and extend for a predetermined distance. In accordance with an embodiment of the invention, the grooves become progessively shallow, finally diminishing at the point near the handle riser.
Bow limb 170, and the previously described embodiments of the instant invention, may be fabricated in accordance with conventional techniques to produce such structures as laminated or fiber-reinforced plastic. Laminated structures generally include layers of wood and fiberglass while fiber-reinforced plastic structures generally include either glass fibers or graphite imbedded in epoxy resin. The grooves 177, as will be appreciated by those skilled in the art, can be machined subsequent to fabrication of the bow limb. Alternately, the grooves and ribs can be molded in place during fabrication. Preferably, the grooves take the form of flutes having a cross-section which is a portion of a circle or an ellipse. It is also apparent that bow limb 170 may be fabricated with a trapezoidal, or other selected cross-section, to be utilized in combination with the previously described embodiments of the instant invention.
Various changes and modifications to the embodiments herein chosen for purposes of illustration will readily occur to those skilled in the art. For example, while the ribs 177 have been shown as having a planar face, the ribs could be fabricated with a rounded or elliptical cross-section. Similarly, while the several embodiments of the invention have been independently illustrated and described, it is understood that the several embodiments are not mutually exclusive. That is, the features of one embodiment, as will be appreciated by those skilled in the art, may be combined with the features of another embodiment. For example, unitary pulley assembly 160, as viewed in FIG. 11, may be utilized with a bow limb of varying cross-section. It is also understood that the terminal portion of the bow limb actually supporting the pulley and the roller may be a bracket, such as can be fabricated of metal, which is attached to the limb proper. To the extent that such modifications and variations do not depart from the spirit of the invention, they are intended to be included within the scope thereof which is limited only by a fair assessment of the following claims.
Having fully described and disclosed the present invention and alternatively preferred embodiments thereof in such clear and concise terms as to enable those skilled in the art to understand and practice the same.
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Limb/pulley torque in a compound bow is negated by providing a restoring force, as a result of the deflected bow when drawn, comprised of unequal components which balance the torsional force imparted to the bow end by the summation of forces applied by the cable. In accordance with one embodiment, the unequal components are achieved by employing unequal cross sectional areas in the material of the respective two sides about the longitudinal axis of the bow. In another embodiment, the pulley/cam structure and the tieoff element which support the cable are spaced at predetermined distances from the longitudinal axis of the bow to yield respective torque having equal magnitude and opposite direction.
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FIELD OF THE INVENTION
The present invention relates to aqueous, heat-curable amino resin mixtures based on etherified amino resins and formaldehyde-binding auxiliaries and to their use for impregnating papers and cardboard.
BACKGROUND OF THE INVENTION
Surfaces and narrow faces of woodbase materials are coated using coated foils (finished foils) and, respectively, impregnated cardboard (Kunststoff-Handbuch Vol. 10 Duroplaste [Thermosets], Hanser-Verlag, 2nd Ed. 1988, p. 462 f., pp. 477 to 479). For the production of finished foils (to coat surfaces) and finished edgings (to coat narrow faces, of boards in particular), absorbent papers are impregnated with solutions or dispersions of (thermosetting) amino resins such as urea-formaldehyde and/or melamine-formaldehyde resins, for example, alone or in combination with dispersions of thermoplastics such as acrylic dispersions or styrene-acrylic dispersions, dried in a stream of hot air and simultaneously cured, and then coated.
In order to ensure adequate penetration of the impregnation liquors into the paper or cardboard, the resin solutions must be processed from aqueous or alcohol dilution. Owing to the high level of cellulose swelling in aqueous systems, the foils and edgings produced from high aqueous dilution are brittle, exhibit a high level of water absorption, and even in the coated state have a surface whose visual appeal is low. The procedure described in DE-A 23 09 334, comprising impregnating liquors diluted with C 1 to C 4 alcohols, does give foils and edgings having good performance properties but requires complex measures for reprocessing the waste gas. The route to a solution that is described in DE-A 44 39 156, modifying melamine resins with guanamines, makes it possible to carry out impregnation from purely aqueous impregnating liquors. A disadvantage, however, is the significantly higher cost of the amino resin, resulting from the use of the guanamines.
The formaldehyde emissions of finished foils and edgings after manufacturing are determined following storage under standard climatic conditions (23° C., 50% relative atmospheric humidity) in accordance with the standard EN 717-2 (FESYP method, gas analysis). Foils and edgings with values of less than 3.6 mg/(h·m 2 ) by the FESYP method meet the limit of the standard (“E 1”). The rates of emission found remain more or less constant even after several weeks of storage under standard climatic conditions. Formaldehyde emissions observed on the films and edgings arise due to the use of urea-formaldehyde and/or melamine-formaldehyde resins in the impregnating liquors for impregnating the paper or cardboard sheets and/or in the coating formulations for coating the films and edgings. By using particularly low-formaldehyde urea-formaldehyde and/or melamine-formaldehyde resins (with low formaldehyde clearage) it is possible to reduce the formaldehyde emissions as measured by the FESYP method (standard climatic conditions) to values around 2 mg/(h·m 2 ).
It has surprisingly now been found that when edgings produced in accordance with the prior art and originally (before the commencement of storage) satisfying the classification E1 (“E1 edgings”), with initial formaldehyde emission values of from 1.0 to 3.5 mg/(h·m 2 ), are stored under nonstandardized climatic conditions, at customary summer temperatures and atmospheric humidities, the formaldehyde emissions rise in the course of a few weeks to values of in some cases much higher than 3.5 mg/(h·m 2 ), and so the edgings no longer meet the E1 criterion. This unexpectedly high increase in the formaldehyde emissions was confirmed by storage under defined conditions in a tropical climate (35° C., 90% relative atmospheric humidity), with measurement being carried out only after 3-day reconditioning under standard climatic conditions following storage under the tropical climatic conditions.
From the prior art it is known that the amount of free formaldehyde and also the formaldehyde emissions may be reduced by adding formaldehyde scavengers such as urea and urea derivatives, for example. For instance, according to DE-A 38 37 965, finished foils and edgings with formaldehyde emissions that are negligible as determined in accordance with DIN 52368 may be produced by adding urea to the melamine-formaldehyde condensation product. Regarding the behavior during and after storage under tropical climatic conditions, however, no information is given. According to DE-A 34 03 136, mixtures of organic hydroxy compounds and an amide are suitable for use as formaldehyde-binding agents in boards made from wood cellulose materials. The use of these mixtures as formaldehyde scavengers in finished foils and edgings is not described. The addition of the mixtures described in DE-A 34 03 136 to amino resins that are used to produce finished foils and edgings leads to a marked deterioration in the flexibility of the finished foils and edgings produced with them. The use of formaldehyde scavengers known from the literature, such as urea, ethyleneurea and propyleneurea, resulted in finished foils and edgings which met the E1 criterion under standard climatic conditions but which markedly exceed the E1 limit of 3.5 mg/(h·m 2 ) under tropical climatic conditions.
It is therefore an object of the present invention to develop amino resin mixtures for producing films and edgings, which can be used to produce, relative to the prior art, finished foils and furniture edgings with significantly reduced formaldehyde emission when stored under tropical climatic conditions, while retaining the required performance properties.
SUMMARY OF THE INVENTION
The invention provides aqueous amino resin compositions comprising amino resins A, formaldehyde-binding additives (auxiliaries) B, which may comprise hydroxyl group-containing polyurethanes B13, and, if desired, acrylic resins C in the form of aqueous dispersions, and water.
DETAILED DESCRIPTION OF THE INVENTION
Where the component B consists only of at least one organic hydroxyl compound which is soluble in water or a monohydric alcohol having 1 to 4 carbon atoms and is selected from dihydric, trihydric and pentahydric alcohols containing up to 6 carbon atoms, pentaerythritol and sorbitol, monosaccharides containing up to 6 carbon atoms, disaccharides containing up to 12 carbon atoms, polysaccharides having an Ostwald viscosity of up to 200 mPa·s at 25° C. and a concentration corresponding to 37% refraction, monohydric and polyhydric aromatic alcohols containing only one benzene ring, and monohydric and polyhydric phenols, and of at least one amide which is soluble in water or a monohydric alcohol having 1 to 4 carbon atoms and is selected from aliphatic amides containing up to 6 carbon atoms and aromatic amides containing only one benzene ring, the presence of at least one of the components B13 and C in the composition is mandatory.
The amino resins A are water-soluble melamine resins, urea resins or mixed melamine-urea condensates which are etherified with C 1 to C 4 alcohols. In the compositions of the invention it is also possible to use those melamine resins in which a fraction (up to 20% of its mass) of the melamine has been replaced by other triazines such as acetoguanamine, caprino-guanamine or benzoguanamine. Preferred resins, however, contain less than 10%, in particular less than 5%, of other triazines, measured on the same scale. Particular preference is given to straight melamine resins or to their cocondensates with urea. The resins are etherified at least partially with the abovementioned alcohols, especially methanol, n-butanol and isobutanol. Particular preference is given to methanol-etherified amino resins.
Particular preference is given above all to melamine resins having an amount-of-substance ratio (molar ratio) of melamine to urea to formaldehyde to methanol of 1 mol: (0 to 2 mol):(1.8 to 5.8 mol):(0.8 to 5.5 mol).
The preparation of the amino resins A is widely known. First of all, methylolation and condensation are carried out by adding formaldehyde to the amino resin formers at pH values from 7 to 10 and temperatures from 40 to 110° C., after which the etherifying alcohol is added and reaction is continued at pH values from 1 to 7 and temperatures from 30 to 80° C. The condensation conditions and etherification conditions are guided by the water dilutability desired for the resin, which amounts to at least 1 part by weight of resin to 5 parts by weight of deionized water, and by the required penetration properties.
As component B, formaldehyde-binding auxiliaries are added. These auxiliaries are selected from mixtures B1 of organic amides B11 having up to 10 carbon atoms and from one to four nitrogen atoms attached in amidelike or imidelike manner, such as urea and/or urea derivatives such as thiourea, ethyleneurea (2-imidazolidinone), propyleneurea, acetyleneurea (glycoluril), and also formamide, acetamide, benzamide, oxalamide, succinimide, malonamide and dicyandiamide, and polyhydroxyl compounds B12 selected from aliphatic linear and branched compounds B121 having from 2 to 6 hydroxyl groups and 1 to 10 carbon atoms, such as glycol, 1,2- and 1,3-propylene glycol, neopentyl glycol, glycerol, trimethylolpropane, ditrimethylolpropane, erythritol, pentaerythritol, dipentaerythritol, sorbitol and mannitol, monosaccharides B122 having up to 6 carbon atoms, and disaccharides B123 having up to 12 carbon atoms, and, if desired, water-soluble or water-dispersible, hydroxyl-containing urethane compounds B13. These urethane compounds are of low mol mass (number-average molar mass M n from 150 to 5000 g/mol, preferably from 300 to 4000 g/mol) and contain hydrophilic groups which are preferably nonionic, especially building blocks derived from glycol or from oligoethylene or polyethylene glycol. Examples of suitable compounds are adducts of aliphatic linear or cyclic diisocyanates, such as 1,2-diisocyanatoethane and 1,6-diisocyanatohexane, with ethylene glycol, diethylene glycol or mixtures thereof with 1,2- or 1,3-propylene glycol, these latter hydrophobic diols being used only in fractions (e.g., less than 25% of the mass of diols overall) such that the adduct remains soluble or dispersible, respectively, in water.
Likewise suitable as formaldehyde-binding component B2 are reaction products containing urethane groups, said products being obtained by reacting polyhydroxyl compounds B21, including the compounds mentioned under B12 and also aliphatic polyhydroxy amines B211 having from 2 to 6 hydroxyl groups and 1 to 4 nitrogen atoms, attached in an aminelike manner, per molecule and containing no free amine-type hydrogen atoms, such as N-methyldiethanolamine, N,N,N′,N′-tetrakis(2-hydroxyethyl) ethylenediamine and triethanolamine with monofunctional or polyfunctional aliphatic, cycloaliphatic or aromatic isocyanates B22, such as hexamethylene diisocyanate, for example.
The addition of formaldehyde-binding auxiliary B (calculated by mass without solvents or diluents, i.e., on a 100% basis) amounts to from 2 to 50 parts by weight per 100 parts by weight of amino resin (likewise on a 100% basis). In addition to the reduction in formaldehyde, it is also found when using a reaction product of hydroxy amines and diisocyanate, such as the reaction product of triethanolamine with hexamethylene diisocyanate in Example 11, that the pot life is extended significantly.
The acrylic resin dispersion C is a dispersion of an acrylic copolymer in water, preparable for example by emulsion copolymerization of olefinically unsaturated monomers, the monomer mixture used for its preparation comprising a predominant fraction (more than 50% of its mass) of what are known as acrylic monomers, i.e., acrylic or methacrylic acid and derivatives thereof, especially esters with aliphatic alcohols having 1 to 10 carbon atoms, esters with aliphatic polyhydroxy compounds having 2 to 10 carbon atoms and at least two hydroxyl groups per molecule, and the nitriles of said acids. Preferred acrylic monomers among the esters are methyl, ethyl, n-butyl, t-butyl, hexyl and 2-ethylhexyl (meth)acrylate, hydroxyethyl and hydroxypropyl (meth)acrylate. It is additionally possible for copolymerizable monomers such as styrene and other aromatic vinyl compounds, esters or monoesters of olefinically unsaturated dicarboxylic acids such as, in particular, maleic acid, vinyl esters such as vinyl acetate or vinyl Versatate, vinyl halides or vinyl ethers to be copolymerized. The synthetic resin dispersions usually have mass fractions of solids of from 25 to 85%; they are added to the amino resin or else to the impregnating liquor itself. The ratio of the mass of the acrylic copolymer in the acrylic dispersion to the mass of the amino resin in its aqueous solution or dispersion may within the composition be from 0 to 150:100, preferably from 20 to 140:100.
The amino resin compositions are used to impregnate absorbent papers or cardboards. The amount of amino resin composition introduced is usually such that the mass per unit area of the paper or cardboard following impregnation and subsequent drying increases by a factor of from 1.3 to 2.5, preferably from 1.4 to 1.8.
The use of the mixtures of the invention leads to a significant reduction in the formaldehyde emissions from the foils and edgings stored under tropical climatic conditions.
EXAMPLES
Preparation of a Partially Etherified Melamine-Formaldehyde (MF) Resin
A 30 l laboratory vessel with stirrer, reflux condenser and thermometer was charged with 6717 g (87.2 mol) of 39% strength aqueous formaldehyde and this initial charge was heated to 68° C. Then 31.5 ml of 2 N sodium hydroxide solution were added followed immediately by 3450 g (27.4 mol) of melamine. Because of the exothermic reaction of melamine and formaldehyde, the mixture rose in temperature to about 83° C. and was held at this temperature until all of the melamine had dissolved. It was then cooled to 55° C. and 16560 g (517 mol) of methanol and 30 ml of 53% strength nitric acid were added. The reaction mixture was heated to 59° C. and stirred at this temperature until a clear solution was formed. After a further 30 minutes, the reaction was terminated by adding about 140 ml of 2 N NaOH. The pH was adjusted to 10. Excess methanol was removed by distillation under reduced pressure (generated by a water jet pump) and the mass fraction of solids of the resin was adjusted to 75% (measured on a 2 g sample, dried at 120° C. for 1 h in a glass dish). The resin had the following characteristics: content (mass fraction of solids): 75%; viscosity at 23° C.: 480 mPa·s, mass fraction of free formaldehyde: 0.17%; water dilutability: unlimited.
Auxiliary BA: Mixture of Glycerol and Urea
100 g of urea were introduced with stirring into 100 g of glycerol and the mixture was heated to 90° C. After the urea had dissolved, it was cooled to 20° C. This gave a mixture with a pastelike consistency.
Auxiliary BB: Mixture of Glycerol, Urea and Polyurethanediol
100 g of urea and 67 g of 88% strength solution of urethanediol (number-average molar mass M n 320 g/mol, OH number 350 mg/g, urethane group content 37 cg/g) were introduced with stirring into 100 g of glycerol and the mixture was heated to 90° C. Following dissolution, the mixture was cooled to 20° C. This gave a mixture with a pastelike consistency.
Auxiliary BC: Reaction Product of Trimethylolpropane (TMP) and Hexamethylene Diisocyanate (HDI)
In a suitable reaction vessel with water separator, 100 g of TMP were melted, after which nitrogen was passed over the material at 140° C. with stirring for 3 hours in order to eliminate traces of water. The system was then cooled to 60° C. and 8 g of HDI was added slowly dropwise with vigorous stirring. The temperature was maintained until the mass fraction of isocyanate groups in the reaction product (NCO value) had fallen below 0.1%. Then the mass fraction of solids was adjusted to 85% using water. The reaction mixture was a colorless solution of low viscosity.
Auxiliary BD: Reaction Product of Tripropylene Glycol and Hexamethylene Diisocyanate
In a suitable reaction vessel with water separator, 100 g of tripropylene glycol were introduced, after which nitrogen was passed over the material at 140° C. with stirring for 3 hours in order to eliminate traces of water. The system was then cooled to 40° C. and 5 g of HDI were added slowly dropwise with vigorous stirring. The temperature was maintained until the NCO value had fallen below 0.1%. Then the mass fraction of solids was adjusted to 85% using water. The reaction mixture was a pale yellow solution of low viscosity.
Auxiliary BE: Reaction Product of Glycerol and Hexamethylene Diisocyanate
In a suitable reaction vessel with water separator, 100 g of glycerol were introduced, after which the water was removed azeotropically at 140° C. for 5 hours using special boiling-point spirit 80/120 as azeotrope former. Following the removal of the azeotrope former (by distillation), the system was then cooled to 60° C. and 5 g of HDI were added slowly dropwise with vigorous stirring. The temperature was maintained until the NCO value had fallen below 0.1%. The reaction mixture was a yellow solution of medium viscosity.
Auxiliary BF: Reaction Product of Triethanolamine and Hexamethylene Diisocyanate
In a suitable reaction vessel with water separator, 100 g of triethanolamine were introduced, after which the water was removed azeotropically at 140° C. for 5 hours using special boiling-point spirit 80/120 as azeotrope former. Following the removal of the azeotrope former, the system was then cooled to 40° C. and 15 g of HDI were added slowly dropwise with vigorous stirring. The temperature was maintained until the NCO value had fallen below 0.1%. The reaction mixture was a yellow solution of medium viscosity.
Performance Testing
The MF resin described above was used in each of the examples. The acrylic dispersion used was a dispersion based on a copolymer of methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, acrylic acid and styrene, having a hydroxyl number of about 120 mg/g and a mass fraction of solids of about 50%, which was diluted if necessary to the lower specified value (45%).
Inventive Examples 1-4 and Comparative Examples 1-4
130 g of 50% acrylic dispersion and 1.7 g of p-toluenesulfonic acid were added in each case to 100 g of the above-described MF resin, along with the auxiliaries indicated in Table 1 for the individual application examples. Following dilution to a liquor concentration of 50%, each of these liquors was used to impregnate papers having a mass per unit area of 200 g/m 2 (typical edgebanding cardboard) and the impregnated edgings were dried at 160° C. to a residual moisture content of about 2%. Following impregnation and drying, the basis weight was about 330 g/m 2 . The impregnated edgings obtained in this way were coated with an aqueous acid-curing varnish (plasticized urea resin; combination of a urea resin with a short- to medium-oil alkyd resin, with p-toluenesulfonic acid as curing agent) and dried at a temperature of 160° C. to a residual moisture content of 1.5%. The varnish addon was about 20 g/m 2 . With regard to their performance properties, each of the edgings obtained met the requirements.
To determine the formaldehyde emissions, the edging samples were conditioned for 3 days under standard climatic conditions (23° C., 50% relative atmospheric humidity) prior to each measurement. To determine the formaldehyde emissions under tropical climatic conditions, the edgings were stored for 1 to 4 weeks at 35° C. and 90% relative atmospheric humidity, after which they were reconditioned for 3 days under standard climatic conditions, prior to the actual measurement. The formaldehyde emissions were measured in accordance with EN 717-2. Table 1 lists the resulting formaldehyde emissions in mg/(h·m 2 ) as averages of the 1- to 4-hour values:
TABLE 1
Directly
after
After
After
After
After
Auxiliary
prep.
1 wk
2 wks
4 wks
6 wks
Inventive
4 g BA
1.7
4.5
3.8
3.6
3.3
Example 1
Inventive
12 g BA
0.8
3.6
3.2
2.8
2.1
Example 2
Inventive
4 g BB
1.4
3.9
3.4
2.5
2.3
Example 3
Inventive
12 g BB
1.1
3.5
3.0
2.3
2.2
Example 4
Comp. Ex. 1
—
2.0
5.2
4.4
3.7
4.2
Comp. Ex. 2
5 g urea
1.9
5.1
4.2
4.1
4.0
Comp. Ex. 3
12 g urea
1.4
5.4
3.8
3.2
2.6
Comp. Ex. 4
12 g glycerol
1.6
4.6
3.7
3.4
2.5
The edgings produced in accordance with Inventive Examples 2 and 4 meet the E1 criterion (i.e., 3.6 mg/h/m 2 ) even after one week of storage under tropical climate conditions.
Inventive Example 5 and Comparative Example 5
1.5 g of p-toluenesulfonic acid were added to 100 g of the above-described MF resin, along with the auxiliaries indicated in Table 2 for the individual application examples. These undiluted liquors were used to impregnate papers (typical edgebanding cardboard; 200 g/m 2 ) by means of knife application from the decorative side, and the impregnated edgings were dried at 160° C. to a residual moisture content of about 1.5%. Thereafter, the basis weight was about 305 g/m 2 . The impregnated edgings thus obtained were coated with an aqueous acid-curing varnish (see above) and dried at a temperature of 160° C. to a residual moisture content of 1.5%. The varnish addon was about 20 g/m 2 . With regard to their performance properties, the edgings obtained in each case met the requirements.
The formaldehyde emissions (reported in mg/(h·m 2 ) were determined as in Example 1.
TABLE 2
Directly
after
After
After
After
After
Auxiliary
prep.
1 wk
2 wks
4 wks
6 wks
Inventive
12 g BB
1.0
2.2
2.1
1.8
1.8
Example 5
Comp. Ex. 5
—
1.0
3.3
2.4
2.9
2.9
Inventive Examples 6 and 7 and Comparative Examples 6 and 7
200 g of 50% acrylic dispersion and 1.7 g of p-toluenesulfonic acid were added to 100 g of the above-described MF resin, along with the amounts of auxiliaries indicated in Table 3 for the individual application examples and also PEG 400 (polyethylene glycol having a number-average molar mass M n of about 400 g/mol). Following dilution to a liquor concentration of 47% (mass fraction of the resins in the aqueous liquor), these resins were used to impregnate papers (typical edgebanding cardboard; mass per unit area about 200 g/m 2 ) and the impregnated edgings were dried at 170° C. to a residual moisture content of about 1.6%. Following impregnation, the final weight was about 330 g/m 2 . The impregnated edgings obtained in this way were coated with an aqueous acid-curing varnish (see above) and dried at a temperature of 160° C. for 60 seconds. The varnish addon was about 16 g/m 2 . With regard to their performance properties, each of the edgings obtained met the requirements.
To determine the formaldehyde emissions, the edging samples were conditioned for 3 days under standard climatic conditions (23° C., 50% relative atmospheric humidity) prior to each measurement. To determine the formaldehyde emissions under tropical climatic conditions, the edgings were stored for 1 week at 35° C. and 90% relative atmospheric humidity, after which they were reconditioned for 3 days under standard climatic conditions, prior to the actual measurement. The formaldehyde emissions were measured in accordance with EN 717-2. Table 3 lists the resulting formaldehyde emissions in mg/(h·m 2 ) as averages of the 1- to 4-hour values:
TABLE 3
Auxiliary as 100%
Directly
After
substance
PEG 400
after prep.
1 week
Inventive
20 g BC
20 g
0.97
2.61
Example 6
Inventive
20 g BD
20 g
1.28
2.63
Example 7
Comp. Ex. 6
—
40 g
1.52
3.49
Comp. Ex. 7
20 g polypropylene
20 g
1.82
2.93
glycol (M n < 400
g/mol)
Inventive Examples 8 and 9 and Comparative Examples 8 and 9
1.6 g of 45% acrylic dispersion and 1.0 g of p-toluenesulfonic acid were added to 100 g of the above-described MF resin, along with the auxiliaries indicated in Table 4 for the individual application examples. Following dilution to a liquor concentration of 75%, these liquors were used to impregnate papers (typical edgebanding cardboard; 200 g/m 2 ) and the impregnated edgings were dried at 180° C. for 90 seconds. The final weight was about 335 g/m 2 . With regard to their performance properties, the uncoated edgings obtained met the requirements.
To determine the formaldehyde emissions, the edging samples were conditioned for 3 days under standard climatic conditions (23° C., 50% relative atmospheric humidity) prior to each measurement. To determine the formaldehyde emissions under tropical climatic conditions, the edgings were stored for 1 week at 35° C. and 90% relative atmospheric humidity, after which they are reconditioned for 3 days under standard climatic conditions, prior to the actual measurement. The formaldehyde emissions were measured in accordance with EN 717-2. Table 4 lists the resulting formaldehyde emissions as averages of the 1- to 4-hour values. The flexibility of the edgings was assessed at room temperature with the aid of the flexural test. The parameter reported was the band radius at which the edging still just did not fracture. As is evident from Table 4, the formaldehyde emissions can be reduced significantly relative to Comparative Example 8 while retaining a very low band radius. The desired formaldehyde reduction cannot be achieved by adding small amounts of urea and sorbitol. Added at higher levels (Comparative Example 9a), there is a deterioration in the flexibility of the edging (larger band radius).
The table indicates the formaldehyde emission in mg/(h·m 2 ) and the band radius in mm.
TABLE 4
Auxiliaxy
Directly
Band
as 100%
PEG
after
After
radi-
substance
400
Sorbitol
Urea
prep.
1 wk
us
Inventive
9 g BC
27 g
—
—
0.64
1.57
5
Example 8
Inventive
9 g BC
27 g
1.1 g
1.1 g
0.49
1.51
5
Example 9
Comp. Ex. 8
—
36 g
—
—
0.97
2.51
6
Comp. Ex. 9
—
36 g
1.1 g
1.1 g
0.80
2.22
5
Comp. Ex.
—
36 g
3.8 g
3.8 g
—
—
8
9a
Inventive Examples 10 and 11 and Comparative Examples 10 and 11
1.7 g of 45% acrylic dispersion and 1.3 g of p-toluenesulfonic acid were added to 100 g of the above-described MF resin, along with the auxiliaries indicated in Table 5 for the individual application examples. Following dilution to a liquor concentration of 75%, these liquors were used to impregnate papers (typical edgebanding cardboard; 200 g/m 2 ) and the impregnated edgings were dried at 180° C. for 90 seconds. The final weight was about 335 g/m 2 . With regard to their performance properties, the uncoated edgings obtained met the requirements.
To determine the formaldehyde emissions, the edging samples were conditioned for 3 days under standard climatic conditions (23° C., 50% relative atmospheric humidity) prior to each measurement. To determine the formaldehyde emissions under tropical climatic conditions, the edgings were stored for 1 week at 35° C. and 90% relative atmospheric humidity, after which they were reconditioned for 3 days under standard climatic conditions, prior to the actual measurement. The formaldehyde emissions were measured in accordance with EN 717-2. Table 5 lists the resulting formaldehyde emissions as averages of the 1- to 4-hour values. The flexibility of the edgings was assessed at room temperature with the aid of the flexural test. The parameter reported was the band radius at which the edging still just did not fracture. As is evident from Table 5, the formaldehyde emissions can be reduced significantly relative to Comparative Example 10 while retaining a very low band radius. The desired formaldehyde reduction cannot be achieved by adding small amounts of urea and sorbitol (Comparative Example 11). The pot life is the time taken for the impregnating liquor, stored at 30° C., to obtain a viscosity (measured as the efflux time in accordance with DIN 53211 at 23° C.) of more than 60 seconds or for the penetration time with a defined test paper to rise to more than 70 seconds. The auxiliary BF has a considerable advantage as compared with the prior art, with regard to formaldehyde emissions and pot life.
TABLE 5
Pot
Directly
life at
Band
after
After
30° C.
radius
Auxiliary 100%
PEG 400
Sorbitol
Urea
prep.
1 wk
in h
in mm
Inventive
9g BE
27 g
1.1 g
1.1 g
0.46
1.47
8
6 to
Example 10
8
Inventive
9g BF
27 g
1.1 g
1.1 g
0.17
0.46
>30
5 to
Example 11
6
Comp. Ex. 10
—
36 g
—
—
0.75
1.98
6
5 to
6
Comp. Ex. 11
—
36 g
1.1 g
1.1 g
0.58
1.82
7
5 to
6
|
Aqueous amino resin compositions comprising amino resins A, formaldehyde-binding additives (auxiliaries) B, which may include hydroxyl-containing polyurethanes B13, acrylic resins C, if desired, in the form of aqueous dispersions, and water, and their use as impregnating compositions for paper for the purpose of producing finished foils and edgings.
| 2
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FIELD OF THE INVENTION
The present invention relates to an adjustable door security system, specifically to a mounting system for reinforcement, repair and improved security of non-standard door assemblies including but not limited to those with sidelights, wooden enclosures and non-standard jamb member thicknesses.
BACKGROUND OF THE INVENTION
There is an ever increasing need and demand for improving the security and structural integrity of entry doors. This demand is being driven by the repeated occurrences of unauthorized and forced entry through entry doors.
Typically such improvements have focused on pick resistant locks, longer and stronger dead bolts, and guard plates. Generally the strengthening and protecting of the locks and bolts have proven to be ill fated attempts at increasing the security of entry doors. The fact is these locks and bolts are mounted and anchor into very soft wooden door slabs and jambs, making their overall effectiveness minimal for security purposes when utilized without overall reinforcement. Traditionally the lock bolt is located in the door slab close to and passing through the doors edge. With this arrangement any significant force applied to the door assembly will cause it to yield and thereby allowing the dead bolt to rip through the door slab. As well the bolt extends into the door jamb through a strike plate that is held in place by short screws. These screws only extend a short distance into the door jamb to secure the strike plate around the receiving opening that is located very close to the inner edge of the jamb. The resulting orientation of the lock bolt, strike plate, and receiving opening is that a thin section of the wooden door jamb is all that remains to resist inward motion of the door slab when the lock bolt is engaged. With this arrangement a person may cause the bolt to rip through the retaining section of the door assembly or jamb merely by applying sufficient force to the door slab itself. Consequently forced entry may be gained without any disturbance or defeat of the security offered by the locking device. Furthermore, due to the construction of doors with sidelights, the jamb stanchions are only secured to the upper jamb and sill plate with minimal hardware that is easily defeated as well.
Historically one point of forced entry has been the door jamb specifically in the region where the free swinging edge of the door slab interfaces with the strike plate area of the door jamb. On doors assemblies with deadbolt locks and wooden door slabs or steel door slabs with wooden cores, the wooden jambs particularly in the area where the bolt of the locking mechanism is common to both, the door jamb is considerable inadequate. Consequently prior devices are designed for strengthening and reinforcing this area. These devices did further the structural support of the door assembly, yet overall these devices have considerable shortcomings. To begin with these devices did nothing to strengthen the overall door assembly, so any applied force was merely transferred to another point of weakness. As well these devices were frequently aesthetically unacceptable and designed for only type of application. Their design features also made installation difficult for a traditional layperson. In some cases the visibility of the device made it more easily defeated. It should also be noted that in many instances such reinforcement devices are sought after the occurrence of forced entry and damage to the doorjamb. The presence of this damage on the existing door assembly will prohibit use of the current devices and prohibit proper application of the strike plate. Furthermore none of the prior art was designed to be adjustable to accommodate jambs of varying width and height with a singular device.
Yet other prior art consists of a door shield or cover plate that wraps around the door from the interior side through the lock area to the exterior. These U-shaped door shields position on the free swinging edge of the door slab with the side panels overlying and extending along opposite sides of the door slab and are typically secured in position by the locking mechanism. Door shielding devices will offer some degree of protection to the door slab, however due to their construction are limited in security they offer. These devices are either outdated, made of material that is more decorative than strength oriented, or are only designed for one lock. As well they offer minimal security when singularly applied.
Still other devices were developed to support and strengthen the door jamb in the area of corresponding to the mounting of the hinges on vertical hung doors. Again these devices are difficult to install in the afforded space of existing doors or require significant detailed finish carpentry to properly complete application. As previously stated these devices are also not designed to be adjustable.
Though these prior art devices were realized with the best intent, the need still exists for a door security device that focuses on the overall structural inadequacy of doors mounted in wooden assemblies and their repair. The current art fails to produce a system that equally and complementary addresses the conventional points of forced entry and structural vulnerability of vertically hung door assemblies for new and existing structures. Though much of the available prior art will afford greater strength, stability and support of vertically hung hinged doors, they nevertheless suffer from a number of disadvantages:
1. The design of the current art does not permit repair of non-standard broken doorjambs while the door and jamb are still hung in place. Thus the door must be replaced or removed to allow the jamb to be repaired prior to deploying these devices.
2. In many instances the current devices cannot be used on non-standard jambs that are damaged.
3. The current devices often have visible parts that are often unsightly. This takes away from the overall aesthetics of the door.
4. The current devices that are installed on the backside of the jamb are difficult to hold in place and align while being attached. These devices will further prove their inadequacy on non-standard assemblies.
5. Due to the material thickness of these jamb reinforcement devices or the method of installation several of them require considerable finish carpentry skill to install. These requirements would make installation difficult for a layperson and prove to be impossible on non-standard jamb assemblies.
6. Many of the components are ineffective due to their singular nature and individual deployment. Using components separately limits the security they can offer.
7. Construction and materials make current devices unsightly. Their finish can also limit there application due to inability to be painted easily or at all.
8. The devices in current use are made from relatively soft material or materials that limit their application as practical security products by design.
9. Many hinge and jamb reinforcement and protectors in current use do not wrap around the jamb. Thus their overall effectiveness for securing and reinforcing the doorjamb is limited by design.
10. The current devices do not offer adjustability for door components outside the realm of modern day industry standard.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to overcome the foregoing drawbacks and shortcomings of the current state of art with door security assemblies that focus on the overall structural inadequacy of doors mounted in and supported by wooden door jambs. The components of the present system can be used alone or in combination to equally and complimentarily address the conventional points of forced entry and structural vulnerability of vertically hung hinged doors with non-standard assemblies, for new and existing structures by utilizing adjustable wrapping technology. Component parts of the system are generally obscured from view by design. The present invention affords greater strength, stability, and adjustable support to vertically hung hinged door assemblies that have not been heretofore achieved, in such a manner. As well the object of the present invention is to provide a structurally sound means of repair for previously damaged said door assemblies. After installation, the component parts alone or in combination cooperate to substantially benefit and enhance the structural integrity of entry door assembly.
As previously disclosed the present invention is for vertically hung hinged entry door assemblies and particularly suited for doors with wooden door jambs. The door assemblies comprise a four sided wooden door jamb with three hinges on one side to hingedly fix the door slab to the door assembly. The assembly components shall also include a door sealing surface that will be situated in the offset surface of the doorjamb and rests against the exterior face of the door slab when in the closed position. Typically there will be a latch bolt lock situated below a dead bolt lock, installed in typical fashion. The door jamb adjacent to the free swinging edge of the door will have openings positioned so as to allow the plunger portion of the dead bolt to engage a strike plate and be received into the door jamb upon closure and lock activation.
The door security system presented here will serve to substantially improve the strength and reliability of the entire door assembly. This system will typically comprise up to four to six main components all suitably manufactured of rugged material, preferably steel, and all necessary securing hardware. Securing hardware will depend upon the door application and will be sized to pass through the doorjamb immediately surrounding the door and penetrate a sufficient depth into the rough frame of the main structure. This system can be incorporated into the manufacturing process of door assemblies, applied cooperatively to new assemblies, or installed on previously hung doors assemblies as functions of the overall system benefit. The latter application can be done by the average layperson with basic hand tools and minimal carpentry experience. Thus significant features of the present invention include allowing for application of the system on previously installed door assemblies and the repairing of damaged assemblies while originally placed, in simple and uncomplicated fashion. The lack of complexity is achieved by the thin three-sided wrapping construction of the components, which allows them to easily slide onto position in the applicable areas.
Installation is accomplished by removing the interior doorjamb decorative trim molding and cutting or removing the fasteners that fix the door jamb to the underlying rough frame. Additionally, at least two screws are removed from each hinge to be modified. The system components are installed in their corresponding locations and the frame is verified to still be square. The finished frame is secured to the rough frame with the proper hardware while at the same time securing all system components. Once installed, the jamb portions of the system are totally concealed on a closed door that has been properly hung and finished in normal fashion (i.e., not visible from the opposite side of the door).
With this system, as previously stated, the components can work together to ensure greater strength, stability and support of vertically hung hinged doors. The components that can be combined to make up this system and their function will follow.
1. The door jamb shielding component corresponding to the door slab free swinging edge and coinciding doorjamb comprise two elongated, substantially equal length members, each having basically “L” shaped cross sections and constructed of about 16-24 gauge steel sheet metal. The two members fit together to form a slide-on sleeve. The sleeve serves to wrap around the door jamb from the facing (i.e., medial) surface of the door jamb adjacent the free swinging edge of the door slab, around to the interior edge of the door jamb (the sleeve is adjustable to accommodate door jambs of varying thicknesses), and finally extending along the backside (i.e., lateral surface) of the door jamb from the interior to the exterior edge. The sleeve mounts with the common adjustable center section of the sleeve positioned to flushly contact and engage the interior edge of the door jamb; while the side panels extend in parallel, flushly contacting the door jamb on both sides, towards the exterior edge. In the region of the free-swinging edge of the door slab and bolt receiving holes of the door jamb, there will be holes in the sleeve to accommodate upper and lower lock bolts. Typically this door assembly arrangement comprises a dead bolt lock oriented above a latch bolt lock. The suitably sized dead bolt lock when manipulated will pass through a first side panel of the sleeve and proceed through the original wooden door jamb. The length of the jamb shield and its the wrapping feature serve to spread any force applied to the doorjamb while transferring such load to the door assembly surrounding structure, thereby preventing the splitting of the door jamb. After installation of the doorjamb component, on a typical door assembly, only a relatively small portion of the jamb member is left exposed above and below the device. Notably this limits the force applied to the doorjamb in the unprotected areas and ensures that this force will be a shear-type force. These shear forces are applied to the entire cross section of the doorjamb in this region instead of the minimal strike plate area of the doorjamb in an unprotected door assembly. This wrapping feature of the sleeve is a major factor in the uniqueness of this component and the present system of invention. The technology allows the doorjamb to be wrapped and, once secured with screws, the rigidity of the jamb is significantly increased. Furthermore the jamb-shielding component allows for universal application by accommodating various lock spacing between the previously mentioned traditional locking mechanisms. The doorjamb shield has considerations for new manufactured door assemblies and may be incorporated into the doorjamb prior to application of the door assembly weather seal at the factory.
2. The hinge side jamb shield comprises two elongated, substantially unequal length members, each having basically “L” shaped cross sections and constructed of about 16-24 gauge steel sheet metal. The two members fit together to form a slide-on sleeve. The sleeve serves to wrap around the doorjamb from the facing (i.e., medial) surface of the doorjamb adjacent the fixed edge the door slab, around to the interior edge of the doorjamb (the sleeve is adjustable to accommodate door jambs of varying thicknesses), and finally extending along the backside (i.e., lateral surface) of the doorjamb from the interior to the exterior edge. The sleeve mounts with the common adjustable center section of the sleeve positioned to flushly contact and engage the interior edge of the doorjamb; while the side panels extending in parallel, flushly contacting the door jamb on both sides, towards the exterior edge. The leading edge of the facing surface portion will come to rest underneath the weather-sealing component of the doorjamb. This adjustable wrapping of the sleeve is a major factor in the uniqueness of this component as well. The present component allows the doorjamb to be wrapped in steel along three sides in the area of the hinge assembly and, once secured with suitable screws, the rigidity of the hinge assembly mounting area of the doorjamb is greatly benefited with improved ability to resist force applied against the jamb. The portion of the component contacting the inside area of the jamb and fitting behind the weather stripping (this portion may be termed the medial panel) will be substantially shorter that the back section of the component (i.e., the portion of the component contacting the lateral surface of the jamb—this portion may be termed the lateral panel) to allow for positioning between the hinge assembly mounting areas. The medial panel of the component is positioned so as to be generally centered between two of the hinges (e.g., the middle hinge and the bottom hinge) on the inside panel, while the lateral panel extends above and below these two hinges. Units installed on new manufactured doors will be incorporated into the frame prior to installation of the door seal at the factory. The primary function of the hinge side jamb shield is to prevent forced entry that occurs by defeating the conventional hinges and mounting hardware of vertically hung hinged steel doors with wooden frames; while at the same time talking advantage of the adjustable nature of said component to maximize the number of different door assemblies to which the device can be applied. Secondly, this component will stabilize the door in the event of attempted forced entry on the lock side of the entryway.
3. The door-shielding component is an elongated section of about 16-24 gauge steel sheet metal that has a generally U-shaped cross section. The door-shielding component serves to wrap around the free-swinging edge of the door slab in the region corresponding to the lock bolts exiting the door. The door-shielding component mounts with the bottom of the “U” flushly contacting the free swinging edge of the door slab and the elongated side panels extending in parallel, flushly contacting the door on both sides, along the interior and exterior faces of the door slab, towards the hinge side of the door. There is an opening in the bottom of the “U” positioned to allow the lock bolt mechanisms to operate without interference. The bolts of the upper and lower locks, when manipulated accordingly, will pass through the door shield component and into the facing surface of the jamb shield component before continuing as detailed in the jamb component description. Another hole with coinciding orientation to the hole in the bottom of the “U” will pass through door shield component perpendicular to the aforementioned holes. These holes will serve as the lock mounting space. The primary function of the door shield component as applied to the present invention is to prevent force on the lock bolts from splitting the free-swinging edge of the door slab. The door-shielding component subsequently serves to prevent tampering with the locking mechanism. Finally this component can be effective in preventing foreign objects from being forced between the door slab free swing edge and the door jamb interface by creating a much closer tolerance in this region. There are at least two versions of this component. A standard version allows for typical lock spacing between the dead bolt and latch bolt. Furthermore a universal application accommodates various lock spacing between the previously mentioned traditional locking mechanisms. The door-shielding component may have considerations for new manufactured door assemblies and may be incorporated into the frame prior to installation of the door assembly weather seal at the factory.
4. The mounting hardware for each alternative component of the present invention will consist of appropriately sized screws. These screws should be sized to allow a minimum one-inch penetration into the rough wood frame of an entryway. When mounting into masonry structures, comparable screws will be required. The mounting hardware component of the present invention be will suitable for this application and ensure that the door jamb portion of the door assembly is substantially secured to the rough frame of the surrounding structure, further assuring proper deployment of the system. As well the mounting hardware of the featured invention will need to be of a sort suited to inhibiting weather related deteriorating and corrosion.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
FIG. 1 is a front elevation view of an entry door assembly incorporating shield components described herein. FIGS. 1A and 1B are top, cross-sectional views of the door shown in FIG. 1 taken along lines A-A and B-B respectively.
FIG. 2 is a front elevation view of an entry door assembly without any trim molding mounted around the doorway.
FIGS. 3 , 3 A, 3 B and 3 C are front elevation, perspective, and side views of the medial half of a door jamb shield for use on the free swinging door side of an entry door assembly.
FIGS. 4 , 4 A, 4 B and 4 C are front elevation, perspective, and side views of the lateral half a door jamb shield for use on the free swinging door side of an entry door assembly.
FIGS. 5 , 5 A and 5 B are perspective views of a portion of a door jamb and door jamb shield corresponding to the free swinging door edge of an entry door assembly.
FIGS. 6 , 6 A, 6 B and 6 C are front elevation, perspective and side views of the medial half of a door jamb shield for use on the hinged door side of an entry door assembly.
FIGS. 7 , 7 A, 7 B and 7 C are front elevation, perspective, and side views of the lateral half a door jamb shield for use on the hinged door side of an entry door assembly.
FIGS. 8 , 8 A and 8 B are perspective views of the portion of a door jamb and a door jamb shield corresponding to the hinged door edge of an entry door assembly.
FIGS. 9 , 9 A-C are front elevation, perspective and side views of alternative examples of a door slab reinforcement plate.
FIGS. 10A and 10B are perspective views of a door slab and door slab shield.
FIG. 11 is a front elevation view of an entry door assembly incorporating alternative shield components described herein. FIG. 11A is a top, cross-sectional view of the door shown in FIG. 1 taken along lines A-A.
FIG. 12 is a front elevation view of an entry door assembly without any trim molding mounted around the doorway, featuring alternative shield components.
FIGS. 13 , 13 A, 13 B and 13 C are front elevation, perspective, and side views of the medial section of a door jamb shield for use on the free swinging door side of an entry door assembly.
FIGS. 14 , 14 A, 14 B and 14 C are front elevation, perspective, and side views of the lateral half a door jamb shield for use on the free swinging door side of an entry door assembly.
FIGS. 15 , 15 A, 15 B and 15 C are perspective views of a portion of a door jamb and door jamb shield corresponding to the free swinging door edge of an entry door assembly.
DETAILED DESCRIPTION OF THE INVENTION
The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.
The present invention described and further detailed herein is particularly useful as a security device for the reinforcement of new door assemblies and, because of the ability to be adjustable, is equally suited for the repair of entry door assemblies with non-standard dimensions, while the door assembly remains in place. In place refers to the door assembly as mounted in an existing structure with means having been taken to ensure fixation to the structure in the current location. Accordingly a door assembly, as shown in FIGS. 1 , 1 A and 1 B and FIG. 2 , shall be an assembly including a door slab ( 10 ) that is hingedly affixed (using hinges ( 24 )) along one vertically elongated edge to the hinge-side vertical jamb member ( 12 ), thereby allowing the door slab to swing and thus accommodate opening and closure. As well the door slab ( 10 ) shall have locking hardware ( 30 )( 50 ) mounted near the vertical free swinging edge ( 11 ) so that the locking hardware may interface closely with the adjacent free-swinging side vertical door jamb member ( 14 ) upon door closure and lock actuation. Lock hardware shall typically involve a dead bolt ( 30 ) that has the locking mechanism ( 32 ) ( 34 ) ( 52 ) ( 54 ), as seen in FIGS. 10A and B, mounted both on the interior face ( 13 ) and exterior face ( 15 ) of the door and is manually manipulated by a key to lawfully unlock the door from the exterior side. A knob or key may be used to control the operation of the dead bolt lock bolt ( 36 ) from the interior side to engage and disengage lock bolt plunger ( 38 ) from the receiving opening ( 72 of FIG. 5A ) of the free-swinging side vertical door jamb member ( 14 ). The lock bolt assembly ( 36 ) will extend perpendicularly, internal to the door slab, from the union of locking mechanisms ( 32 )( 34 ) on the door slab facing to the free swinging edge ( 11 ) where it is typically secured. A similarly arranged and actuated latch bolt assembly ( 50 ) shall be positioned some distance below the dead bolt ( 30 ) allowing the bolt plunger ( 58 ), of the latch bolt ( 56 ), to catch and remain engaged in the receiving opening ( 74 of FIG. 5A ) of the free-swinging side vertical door jamb member ( 14 ), while the door is closed. The bolt plunger ( 58 ) of the latch bolt ( 56 ) can be retracted by manipulation of the door knobs ( 52 )( 54 ) that will be positioned on the interior and exterior faces of the door ( 13 ) ( 15 ), according to typical placement. The latch bolt locking assembly ( 50 ) is typically designed to accept a key, for lawful entry, in the exterior locking mechanism ( 53 ) positioned in the center in the door knob. The interior door knob ( 54 ) will be assembled with a manually operated knob (not illustrated), centrally located, that can be fingered to lock and unlock the latch bolt; thereby allowing for turning of the door knobs ( 52 ) ( 54 ) to disengage the latch bolt plunger ( 58 ) from the corresponding strike plate ( 26 ) and receiving ( 74 ) opening in the door jamb member ( 14 ).
The door jamb members shall ordinarily comprise opposing vertical jamb members ( 12 )( 14 ) that will be joined together by upper and lower common horizontal jamb members ( 22 ) ( 28 ). Each jamb member on its facing surface will include an offset surface ( 70 ) along its length which will cause the member to recess and have two distinct planes along the facing surface ( 71 ) into which a weather barrier is mounted. The offset surface ( 70 ) shall serve as a sealing surface for the exterior door slab face ( 15 ) as well it will be a stop for the free swinging edge ( 11 ), in the closed position. The vertical and upper jamb members ( 12 )( 14 ) ( 22 ) are typically of wooden composition, while the lower member ( 28 ) may be similarly created or of variable materials more resistant to weather related long term damage.
A pair of wooden vertical stud members ( 60 ) shall be immediately adjacent and parallel to the vertical jamb members ( 12 ) ( 14 ), separated only by positioning shims ( 64 ). These studs ( 60 ) will be interposed between the walls of the structure ( 66 ) and joined together above and below the door jamb by a common header ( 62 ) and common floor ( 68 ) respectively to form the rough frame ( 60 ) ( 62 ) ( 68 ). The door assembly detail in FIG. 2 including the door enclosure ( 12 )( 14 )( 22 )( 28 ) is securely affixed in the rough frame ( 60 ) ( 62 )( 68 ), positioned true with shims ( 64 ) to ensure proper alignment, and secured with suitable attaching hardware. Decorative molding (not illustrated) shall conceal the area immediately around the door jamb ( 12 )( 14 )( 22 )( 28 ) on the inner, outer walls ( 60 ) and extends along floor ( 68 ) of the structure.
Subsequently the door slab ( 10 ), on the affixed edge ( 17 ), is attached to the doorjamb stanchion with common hinge assemblies ( 24 ) secured by relatively short screws that are ordinarily shallowly set in the soft wood substrate of the hinge-side vertical doorjamb member ( 12 ). The plunger portion of both lock bolts ( 38 )( 58 ) pass through a strike plate (not illustrated) of conventional construction and similarly mounted on the free-swinging side vertical jamb member ( 14 ), then engage the free-swinging side vertical doorjamb member ( 14 ) and engaging the bolt receiving openings ( 72 ) ( 74 ), very near the interior edge of engage the free-swinging side vertical doorjamb member ( 14 ). Typically the bolt plunger of the dead bolt ( 38 ) will penetrate more deeply into the vertical door jamb member than the bolt plunger of the latch bolt ( 58 ) and consequently requires the receiving opening to be suitably sized.
Embodiments of the present invention provide a means for providing an adjustable door assembly security device that secures, reinforces and repairs a door assembly. The embodiment of FIG. 2 will demonstrate a security system including door jamb stanchion, door jamb member and door slab improvement shields suitably situated on a door assembly. The attached figures are examples of the mounting components in accordance with the current invention.
As seen in FIGS. 3A-C , 4 A-C and FIGS. 5A and B, the jamb shielding component corresponding to the free swinging side of the door comprises two vertically elongated, substantially equal length members having basically “L” shaped cross sections. The members are constructed of about 16-24 gauge steel sheet metal, and fit together to form a slide-on sleeve. When positioned together, the members ( 80 )( 130 ) form a metal elongated sleeve shaped in a manner so as to generally present a J shaped cross section. The first or medial member ( 80 ) comprises a medial side panel ( 86 ) and an interior side panel ( 89 ). The medial side panel ( 86 ) of the medial member ( 80 ) of the free-swinging side jamb shielding component extends, in close proximity, along the offset plane ( 76 ) of the facing surface ( 71 ) of the vertical jamb member ( 14 ). The interior side panel ( 89 ) of the medial member ( 80 ) of the shielding component is then contoured to advance perpendicular to the medial side panel ( 86 ), flushly contacting the interior surface ( 78 ) of the doorjamb member ( 14 ). The interior side panel ( 89 ) of the medial member ( 80 ) has a plurality of slots ( 83 ) positioned side by side in groups, with the groups of slots being spaced vertically along the length (while FIG. 3 illustrates seven groups of four slots each, the number and spacing of the slots may vary). The second or lateral member ( 130 ) comprises an interior side panel ( 139 ) and a lateral side panel ( 136 ). The interior side panel ( 139 ) of the lateral member ( 130 ) partially overlaps and engages with (in a manner described in more detail below) the interior side panel ( 89 ) of the medial member ( 80 ), thereby forming a unified common center section that flushly contacts and covers the interior surface ( 78 ) of the vertical jamb member ( 14 ). The lateral side panel ( 136 ) of the lateral member ( 130 ) bends perpendicular to the interior side panel ( 139 ) to be positioned along and flushly contacting the lateral surface of the vertical door jamb member ( 14 ) immediately adjacent the corresponding vertical stud of the rough frame ( 60 ). The lateral member ( 130 ) has tabs ( 132 ) positioned along the length of the interior side panel ( 136 ). The tabs are on the edge of the interior side panel ( 139 ) that is opposite the edge that meets the lateral side panel ( 136 ). The tabs extend substantially perpendicular to the interior side panel ( 139 ), such that the tabs are substantially parallel to the lateral side panel ( 136 ). The spacing of the tabs along the edge of the interior side panel of the lateral member ( 130 ) corresponds to the spacing of the groups of slots along the length of the interior side panel of the medial member ( 80 ), such that each tab will extend through a slot in the corresponding group of slots when the two sections are mounted on the door jamb member and engage the interior edge ( 78 ) of the vertical jamb section ( 14 ). The tabs may be pointed, as illustrated in FIG. 4 , to enable the tabs to easily penetrate the wooden jamb member. Which slot in each group that a tab extends through depends on the thickness of the jamb member. Having multiple slots in each group enables the device to mount to jamb members of different thicknesses. The medial member ( 80 ) will have multiple countersunk openings ( 81 ) along the medial side panel ( 86 ) into which the mounting hardware ( 100 ) is secured. As well there will be a plurality of substantially identically sized cutouts or knockouts ( 82 ) approximately centered and aligned vertically along the length of the medial side panel. A number of the knockouts or cutouts are provided, such that at least some will directly coincide with the lock bolt plunger receiving openings ( 72 ) ( 74 ) of the corresponding vertical door jamb stanchion ( 14 ).
The free-swinging side jamb shielding component ( 80 )( 130 ), once assembled, will be incorporated onto the vertical doorjamb member in the area of the narrowed offset plane ( 76 ) specific to the central region of the vertical jamb member. The component will be arranged such that the common center section (i.e., the engaged and partially overlapping interior side panels ( 89 )( 139 )) of the elongated metal sleeve ( 80 )( 130 ), created by the engagement of the tabs of the lateral member ( 130 ) into the slots of the medial member ( 80 ) and the coinciding perpendicular bends of the sections, will be facing the interior edge of the vertical door jamb member ( 14 ) previously detailed. The medial side panel ( 86 ) of the medial member ( 80 ) of the metal sleeve will extend onto the offset plane ( 76 ) of the vertical door jamb member facing surface ( 71 ) with its extreme edge (i.e., the edge opposite the edge that is shared with the interior side panel ( 89 )) coming to rest flush against the offset surface ( 71 ) while maintaining a close parallel orientation to the offset plane ( 76 ). The lateral member ( 130 ) will extend along closely and be parallel to the same vertical doorjamb member's posterior or lateral region. The common center section, created by the engagement and partial overlapping of the interior side panels of the lateral and medial members, connects the lateral and medial members after engaging the tabs of one into the slots of the other so that the medial side panel of the medial member and the lateral side panel of the lateral member are substantially parallel to each other. The distance between the medial side panel of the medial member and the lateral side panel of the lateral member is adjustable as described above (based on which slots the tabs go into) such that the distance is substantially the same as the thickness of the doorjamb when applied.
Accordingly when the free-swinging side jamb shielding component is arranged as previously mentioned the position is adjusted such that the medial member ( 80 ) generally aligns with the vertical center of the corresponding vertical doorjamb member ( 14 ) (as seen in FIG. 5A ). The lateral member ( 130 ) is then arranged as previously mentioned and is engaged with the medial member. When thusly positioned the component is secured with suitable mounting hardware. Accordingly when the jamb shielding component is arranged as previously mentioned, the position is adjusted such that the knockouts ( 82 ) in the medial member ( 80 ) correspond, with specific alignment, to the bolt plunger receiving holes ( 72 ) ( 74 ) in the corresponding vertical door jamb member ( 14 ). When correctly positioned, the knockouts that align with the bolt plunger receiving holes ( 72 ) ( 74 ) are removed and the component is secured with suitable mounting hardware. This mounting hardware will comprise screws ( 100 ) that are placed in the countersunk openings ( 81 ) along the medial side panel of the jamb shielding component ( 80 ). Additionally, the tabs ( 132 ) of the lateral member ( 130 ) also help to secure the medial member ( 80 ) in position. After properly preparing the material immediately beneath the countersunk opening ( 81 ), by means of pre-drilling (taking care to drill deep enough to create corresponding holes in the lateral side panel of the lateral member, as the lateral member does not comprise preexisting holes to receive the screws), the screws are received in the opening such that they pass through the medial member ( 80 ) of the jamb shield component, through the door jamb member ( 14 ), through the lateral member ( 130 ), through the shim material ( 64 ), and extend substantially into the rough frame ( 60 ) of the structure. When sufficiently engaged, the screw heads will come to rest in the countersunk opening ( 81 ) of the component and appear to be in the same plane.
As mentioned above, the medial member ( 80 ) and the lateral member ( 130 ) of this embodiment are of substantially equal length. The length of these members is typically selected to be long enough to cover a substantial portion of the vertical jamb member ( 114 ) but short enough to be mountable on many different height door assemblies.
The featured embodiment of FIGS. 6A-C , 7 A-C and FIGS. 8A and B relate to a hinge side jamb shield that comprises two elongated, substantially unequal length members ( 90 )( 130 ) having basically “L” shaped cross sections. The members are constructed of about 16-24 gauge steel sheet metal, and fit together to form a slide on-sleeve. When positioned together the members form a metal elongated sleeve shaped in a manner so as to generally present a J shaped cross section. The first or medial member ( 90 ) comprises a medial side panel ( 96 ) and an interior side panel ( 99 ). The medial side panel ( 96 ) of the medial member ( 90 ) extends, in close proximity, along the offset plane ( 76 ) of the facing surface ( 71 ) of the vertical jamb member ( 12 ). The medial member ( 90 ) will be formed with a substantially shorter length than the lateral member ( 130 ) and be centrally located when attached to the lateral member ( 130 ), to accommodate being positioned between the fixed portion of two of the hinges ( 24 ) attached to the vertical jamb section ( 12 ). The interior side panel ( 99 ) of the medial member ( 90 ) is then contoured to advance perpendicular to the medial side panel ( 96 ), flushly contacting the interior surface ( 78 ) of the doorjamb member ( 12 ). The interior side panel ( 99 ) of the medial member ( 90 ) has a plurality of slots ( 93 ) positioned side by side in groups, with the groups being spaced vertically along the length (while FIG. 6 illustrates three groups of four slots each, the number and spacing of the slots may vary). The second or lateral member ( 130 ) comprises an interior side panel ( 139 ) and a lateral side panel ( 136 ). The interior side panel ( 139 ) comprises two hinge cutouts ( 138 ) to enable the lateral member to be mounted on the jamb member without interfering with the hinges. The interior side panel ( 139 ) of the lateral member ( 130 ) partially overlaps and engages with (in a manner described in more detail below) the interior side panel ( 99 ) of the medial member ( 90 ), thereby forming a unified common center section that flushly contacts and covers the interior surface ( 78 ) of the vertical jamb member ( 12 ). The lateral side panel ( 136 ) of the lateral member ( 130 ) bends perpendicular to the interior side panel ( 139 ) to be positioned along and flushly contacting the lateral surface of the vertical door jamb member ( 12 ) immediately adjacent the corresponding vertical stud of the rough frame ( 60 ). The lateral member ( 130 ) has tabs ( 132 ) positioned along the length of the interior side panel ( 136 ). The tabs are on the edge of the interior side panel ( 139 ) that is opposite the edge that meets the lateral side panel ( 136 ). The tabs extend substantially perpendicular to the interior side panel ( 139 ), such that the tabs are substantially parallel to the lateral side panel ( 136 ). The spacing of the tabs along the edge of the interior side panel of the lateral member ( 130 ) corresponds to the spacing of the groups of slots along the length of the interior side panel of the medial member ( 90 ), such that each tab will extend through a slot in the corresponding group of slots when the two sections are mounted on the door jamb member and engage the interior edge ( 78 ) of the vertical jamb section ( 12 ). The tabs may be pointed, as illustrated in FIG. 7 , to enable the tabs to easily penetrate the wooden jamb member. Which slot in each group that a tab extends through depends on the thickness of the jamb member. Having multiple slots in each group enables the device to mount to jamb members of different thicknesses. The medial member ( 90 ) will have multiple countersunk openings ( 91 ) along the medial side panel ( 96 ) into which the mounting hardware ( 100 ) is secured.
The hinge-side jamb-shielding component ( 90 )( 130 ) will be incorporated onto the vertical doorjamb member ( 12 ) in the area of the narrowed offset plane ( 76 ) specific to the central region of the vertical jamb member. The component will be arranged such that the common center section (i.e., the engaged and partially overlapping interior side panels ( 99 )( 139 )) of the elongated metal sleeve ( 90 )( 130 ) created by the engagement of the tabs of the lateral member ( 130 ) into the slots of the medial member ( 90 ) and the coinciding perpendicular bends of the sections, will be facing the interior edge ( 78 ) of the vertical door jamb member ( 12 ) previously detailed. The medial side panel ( 96 ) of the medial member ( 90 ) of the metal sleeve ( 90 )( 130 ) will extend onto the offset plane ( 76 ) of the vertical door jamb member facing surface ( 71 ) with its extreme edge (i.e., the edge opposite the edge that is shared with the interior side panel ( 99 )) coming to rest flush against the offset surface ( 71 ) while maintaining a close parallel orientation to the offset plane ( 76 ). The lateral member ( 130 ) will extend along closely and be parallel to the same vertical doorjamb member's posterior or lateral region. The common center section ( 99 )( 139 ), created by the engagement and partial overlapping of the interior side panels of the lateral and medial members, connects the lateral and medial members after engaging the tabs of one into the slots of the other so that the medial side panel of the medial member and the lateral side panel of the lateral member are substantially parallel to each other. The distance between the medial side panel of the medial member and the lateral side panel of the lateral member is adjustable as described above (based on which slots the tabs go into) such that the distance is substantially the same as the thickness of the doorjamb when applied.
Accordingly when the hinge-side jamb shielding component is arranged as previously mentioned the position is determined such that the medial member ( 90 ) is generally positioned between the middle and bottom hinges on the vertical doorjamb member ( 12 ) (as seen in FIGS. 8A and B). The hinge-side jamb shielding component could be positioned with the medial member positioned between the middle and top hinges, but the lower portion of the door is more likely to receive a kicking force from an intruder and therefore is more desirable to strengthen. The lateral member ( 130 ) is then arranged as previously mentioned and is engaged with the medial member. When thusly positioned the component is secured with suitable mounting hardware. This mounting hardware will comprise screws ( 100 ) that are placed in the countersunk openings ( 91 ) along the medial side panel of the jamb shielding component ( 90 ). Additionally, the tabs ( 132 ) of the lateral member ( 130 ) also help to secure the medial member ( 90 ) in position. After properly preparing the material immediately beneath the countersunk opening ( 91 ), by means of pre-drilling (taking care to drill deep enough to create corresponding holes in the lateral side panel of the lateral member, as the lateral member does not comprise preexisting holes to receive the screws), the screws are received in the opening such that they pass through the medial member ( 90 ), through the door jamb member ( 14 ), through the lateral member ( 130 ), through the shim material ( 64 ), and extend substantially into the rough frame ( 60 ) of the structure. When sufficiently engaged the screw heads will come to rest in the countersunk opening ( 81 ) of the component and appear to be in the same plane.
In an alternative embodiment of the invention, lateral member ( 130 ) is long enough to span all three hinges and has three hinge cutouts (rather than two as in the embodiment illustrated in FIG. 7 ). In this embodiment, two medial members ( 90 ) will be used to engage with the longer lateral member—one medial member being positioned between the middle and bottom hinges and one medial member being positioned between the middle and top hinges.
Note that, in the illustrated embodiment of the invention, the lateral member of the free-swinging side shield and the lateral member of the hinge-side shield are identical. This enables one stock keeping unit (SKU) to be used for two different purposes, thereby reducing manufacturing and inventory costs. The hinge cutouts ( 138 ), which are necessary on the hinge-side shield, are included on the free-swinging side shield (even though they are not necessary) to enable this identicalness.
As represented in FIGS. 9A-C and FIGS. 10A and B, the door shielding component of the present invention is an elongated steel sleeve ( 120 ) that is shaped in a manner to have a common center section closely abutted to the free swinging edge ( 11 ) of the door slab. The sleeve will be constructed with openings ( 126 ) in this common center section that are positioned to coincide with specific alignment and accommodate the lock bolt plunger ( 38 ) ( 58 ) operation as it is manipulated to extend and retract from the door slab edge ( 11 ) while respectively engaging and disengaging the corresponding vertical jamb member ( 14 ). The door shield component is further contoured to have perpendicular side panels ( 122 paralleling and in close proximity to the large facing surfaces of the door slab ( 13 ) ( 15 ). The panel ( 122 ) have openings ( 124 ) of sufficiently sized for installation of typical locking devices ( 30 ) ( 50 ) as previously detailed. The component will be arranged such that the open section of the elongated metal sleeve created by the fore mentioned coinciding perpendicular bends of the sleeve will be immediately against the free swinging edge of the door slab ( 11 ). In this position the openings ( 126 ) in this portion will coincide with specific alignment of the lock bolt plungers ( 38 ) ( 58 ), thereby permitting it to be manipulated to extend and retract from the door slab edge ( 11 ) while respectively engaging and disengaging the corresponding vertical jamb member ( 14 ). The side panels ( 122 ) extend, snugly against the interior and exterior facing surfaces ( 13 ) ( 15 ), towards the fixed edge of the door slab ( 17 ). Openings 127 in the common center section receive fasteners to secure the door shielding component to the door slab edge ( 11 ).
FIGS. 1 through 15 are representative of alternate configurations of the jamb and hinge shielding components. Basically the major variation being represented in these drawing involves how the medial and lateral members engage. As in the above described embodiment, this configuration allows the two-part sleeve to be mechanically and slidably adjustable to accommodate substantial variations in jamb thickness and still be arranged on the door assembly as previously detailed. This feature will allow for positional or slidable adjustment of said components with respect to a given jamb thickness. Alternative construction in this manner permits use of the jamb shielding components in cooperation with the alternate embodiments of the door assemblies.
FIGS. 11 through 15 depict a jamb shielding component corresponding to the free swinging side of the door that comprises two vertically elongated, substantially equal length members having basically “L” shaped cross sections. The members are constructed of about 16-24 gauge steel sheet metal, and fit together to form a slide-on sleeve. When positioned together the members ( 150 )( 160 ) form a metal elongated sleeve shaped in a manner so as to generally present a J shaped cross section. The first or medial member ( 150 ) comprises a medial side panel ( 156 ) and an interior side panel ( 159 ). The interior side panel ( 159 ) comprises tabs ( 155 ) at either end. The tabs are planar and contiguous with the interior side panel and extend outward (i.e., away from the edge shared with the medial side panel ( 156 )) perpendicular to the longitudinal axis of the interior side panel. The second or lateral member ( 160 ) comprises a lateral side panel ( 166 ) and an interior side panel ( 169 ). The interior side panel ( 169 ) of the lateral member ( 160 ) comprises slots ( 165 ) at either end for receiving corresponding tabs of the medial member. The opposite ends of interior side panel ( 169 ) extend beyond the corresponding ends of the lateral side panel ( 166 ). Both of these two extended portions are folded into a J shape to form the slots.
The medial side panel ( 156 ) of the medial member ( 150 ) of the free-swinging side jamb shielding component of this alternative embodiment extends, in close proximity, along the offset plane ( 76 ) of the facing surface ( 71 ) of the vertical jamb member ( 14 ). The interior side panel ( 159 ) of the medial member ( 150 ) is then contoured to advance perpendicular to the medial side panel ( 156 ), flushly contacting the interior surface ( 78 ) of the doorjamb member ( 14 ). The interior side panel ( 169 ) of the lateral member ( 160 ) engages with (by receiving the tabs of the medial member in its slots ( 165 )) the interior side panel ( 159 ) of the medial member ( 150 ), thereby forming a unified common center section that flushly contacts and covers the interior surface ( 78 ) of the vertical jamb member ( 14 ). The lateral side panel ( 166 ) of the lateral member ( 160 ) bends perpendicular to the interior side panel ( 169 ) to be positioned along and flushly contacting the lateral surface of the vertical door jamb member ( 14 ) immediately adjacent the corresponding vertical stud of the rough frame ( 60 ). The tabs ( 155 ) slide through the slots ( 165 ) and then fold in to flushly contact the lateral surface of the door jamb member (as illustrated in FIG. 11A and in the inset of FIG. 15C ). The component will have multiple countersunk openings ( 151 ) along the medial side panel ( 156 ) of the medial member ( 150 ) into which the mounting hardware ( 100 ) is secured. Multiple (non-countersunk) openings ( 161 ) are positioned along the lateral side panel ( 166 ) of the lateral member ( 160 ) to correspond to the multiple countersunk openings ( 151 ) along the medial side panel ( 156 ) of the medial member ( 150 ). Openings ( 161 ) are larger than openings ( 151 ), because openings ( 161 ) are designed to merely enable the fasteners to pass unimpeded through the lateral member ( 160 ) into the underlying structure as discussed in more detail below. The larger size of openings ( 161 ) provides sufficient tolerance for this unimpeded passage without requiring precise mounting alignment of the lateral and medial members. As well there will be a plurality of substantially identically sized cutouts or knockouts ( 152 ) approximately centered (relative to the longitudinal axis) and aligned vertically along the length of the medial side panel ( 156 ). A number of the knockouts or cutouts are provided, such that at least some will directly coincide with the lock bolt plunger receiving openings ( 72 ) ( 74 ) of the corresponding vertical door jamb stanchion ( 14 ).
The jamb shielding component ( 150 )( 160 ), once assembled, will be incorporated onto the vertical doorjamb member in the area of the narrowed offset plane ( 76 ) specific to the central region of the vertical jamb member. The component will be arranged such that the common center section ( 159 )( 169 ) of the elongated metal sleeve ( 150 )( 160 ), created by slidably engaging the tabs of the medial member into the slots of the lateral member and the coinciding perpendicular bends of the sections, will be facing the interior edge ( 78 ) of the vertical door jamb member ( 14 ) previously detailed. The medial member ( 150 ) of the metal sleeve will extend onto the offset plane ( 76 ) of the vertical door jamb member facing surface ( 71 ) with its extreme edge (i.e., the edge opposite the edge that is shared with the interior side panel ( 159 )) coming to rest flush against the offset surface ( 71 ) while maintaining a close parallel orientation to the offset plane ( 76 ). The lateral member ( 160 ) will extend along closely and be parallel to the same vertical doorjamb member's lateral surface. The common center section ( 159 ) ( 169 ), created by the engagement of the interior side panels of the medial and lateral members, connects the medial and lateral members after engaging the tabs of one into the slots of the other so that the medial side panel of the medial member and the lateral side panel of the lateral member are substantially parallel to each other. The distance between the medial side panel of the medial member and the lateral side panel of the lateral member is adjustable (based on how far the tabs slide into the slots) such that the distance is substantially the same as the thickness of the doorjamb. Accordingly when the jamb shielding component is arranged as previously mentioned the position is adjusted such that the medial member ( 150 ) generally aligns with the vertical center of the corresponding vertical doorjamb member ( 14 ). When the jamb shielding component is arranged, the position is adjusted such that the knockouts ( 152 ) in the medial member ( 150 ) correspond, with specific alignment, to the bolt plunger receiving holes ( 72 ) ( 74 ) in the corresponding vertical door jamb member ( 14 ). When correctly positioned, the knockouts that align with the bolt plunger receiving holes ( 72 ) ( 74 ) are removed and the component is secured with suitable mounting hardware. Elongated rectangular cutouts ( 162 ) of the lateral side panel ( 166 ) of the lateral member ( 160 ) enable the lock bolts (where necessary and/or desirable) to pass through the lateral member ( 160 ) into the underlying frame structure, thereby providing even further installation flexibility, strength and security. When thusly positioned the component is secured with suitable mounting hardware. This mounting hardware will comprise screws ( 100 ) that are placed in the countersunk openings ( 151 ) along the medial side panel ( 150 ). Additionally, the subsequent bending of the tabs ( 155 ) around the lateral surface of the door jamb member also help to secure the medial member ( 150 ) in position. After properly preparing the material immediately beneath the countersunk opening ( 151 ), by means of pre-drilling, taking care to drill straight and deep enough to pass through the corresponding pre-existing holes ( 162 ) in the lateral side panel of the lateral member, the screws are received in the opening such that they pass through the medial side panel ( 156 ) of the medial member ( 150 ), through the door jamb member ( 14 ), through the pre-existing holes ( 162 ) in the lateral side panel ( 166 ) of the lateral member ( 160 ), through the shim material ( 64 ), and extend substantially into the rough frame ( 60 ) of the structure. When sufficiently engaged, the screw heads will come to rest in the countersunk opening ( 151 ) of the component and appear to be in the same plane.
In use, the present system of invention can be characterized by its ease of installation, adaptability, superior design and simplicity. Briefly the steps for installation follow: Remove interior trim modeling and strike plates. Assemble the jamb shielding components so they are appropriately sized for the particular jamb member. Position the jamb shielding components ( 80 ) ( 130 ) ( 90 ) ( 130 ) or ( 150 ) ( 160 ), ensuring the line up with the lock bolt plungers openings ( 72 ) ( 74 ). Form holes in the corresponding door jamb member for reception of screws at locations ( 81 ). Secure the jamb shielding components in place with suitable screws ( 100 ). Position the hinge side jamb shielding components ( 90 )( 130 ) and form holes in the corresponding door jamb ( 12 )( 14 ), as detailed, for the reception of screws. Secure the hinge side jamb shield in place as detailed with suitable screws. Remove the locking devices ( 30 ) ( 50 ) from the door slab surfaces ( 13 ) ( 15 ). Position the door shield component on the door slab free swinging edge so as to allow the lock bolt plungers ( 38 ) ( 58 ) to pass through the corresponding openings in it ( 116 ). Secure the component in place with suitable screws and re-install the locking devices ( 30 ) ( 50 ) over the door shield component side panels ( 112 ), securing it in place.
The different shield components described herein are made of steel for strength reasons. Other metals or strong materials may alternatively be used to form the shields. Also, the actual dimensions of the various shield components may vary. The door jamb shield sleeve used for the door slab free swinging edge is from about six inches to about five feet long, or alternatively about one foot to three feet long, or in one example about twenty inches long. The corresponding side panels have widths of from about a half inch to about six inches. In one example, one side panel is about an inch wide, and the second side panel is about three inches wide. For a door jamb shield sleeve used on the door hinge side of the jamb, the sleeve is about four inches to two feet long, and in one example about six inches long. The side panels may have widths of from about a half inch to about six inches. In one example, one side panel is about an inch wide, and the second side panel is about three inches wide and are adjustable from about one half inch to about but not limited to three inches. The size and shape of the cutouts or knockouts are designed to correspond to the dimensions of the lock bolt receiving holes or hinge plate and are typically rectangular.
In applications involving repair of a door assembly, using the present invention, as much of the remaining door jamb member or door slab material as possible should be positioned to accept the appropriate components. When these door assemblies are severely damaged additional alignment maybe necessary to properly install the present system.
When the components of the present door security system are deployed alone or in combination as previously detailed they form a cohesive system that improves the security offered by a door assembly. The components reinforce and retrofit existing doors assemblies and as well repairs damaged assemblies of varied jamb thickness. These means are achieved by the components wrapping key elements of a door assembly in metal and securing them to the surrounding structure. The adjustable wrapping design reinforces these elements by placing metal along three sides of each piece and particularly along the typical load bearing surfaces exposed to a forced entry attempt, thereby preventing the splintering of the door assembly. The repair function allows for the door assembly elements to be easily repaired by sliding the door security components into place thereby wrapping the previously damaged areas even doors with non-standard component dimensions. This will also serve to conceal the prior damage. On a typical door assembly this means the door jamb members on either side of the assembly, and the door slab are wrapped in steel, while remaining in place, to repair or prevent further damage when substantial force is applied.
Having thus described and detailed the present invention, it is to be understood that many obvious and apparent variations in construction and arrangement may be made without departing from the overall scope and spirit thereof as defined by the appended claims. Furthermore, it is intended that the foregoing specifications and accompanying drawings be interpreted as illustrative rather than in a limiting sense.
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A door security system serves to substantially improve the reliability of the entire door assemblies with non-standard door jamb thicknesses. The system may comprise up to four or more components. An adjustable door jamb shield may be mounted around a door jamb on the side of the door jamb corresponding to the door slab free swinging edge. Another adjustable door jamb shield may also be mounted on a door jamb on the hinge side of the door jamb. The adjustable shields comprise attachable sleeves that wrap on three sides around the door jamb to reinforce and stabilize the door system.
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BACKGROUND OF THE INVENTION
The invention relates to an open-end spinning machine including a spinning rotor and a pair of draw-off rollers, equipped with a thread tube adjacent the spinning chamber. The thread tube is constructed as an ejector nozzle which is capable of transporting the end of the thread back into the opening of the spinning chamber for reattachment to the fibers located therein.
In open-end spinning machines, a thread breakage is repaired by transporting the end of the thread into the fiber collection groove of the spinning rotor in the spinning chamber so that the end of the thread reattaches to the fibers located in the collection groove and the new thread is then pulled out of the spinning rotor. Whenever the spinning machine is stopped, thread breakage takes place, so that, when an open-end spinning machine is restarted, all the broken threads at a, sometimes, large number of individual spinning stations within the machine must be repaired prior to start-up. Until the present time, a requirement for automatic thread reattachment was that the end of the thread to be reattached had to be within the suction region of the spinning chamber and, more particularly, in the thread draw-off channel of the spinning chamber, at the time when spinning is resumed. It had been proposed to fulfill this condition by providing that the draw-off mechanism for the thread is arrested so rapidly when a thread breakage occurs during normal spinning that the end of the thread will still be within the effective suction region of the spinning chamber which includes the spinning rotor. However, the customary high thread delivery speeds make such a condition very difficult to fulfill because they require very rapidly-acting sensors, clutches and brakes for arresting the rotating spools and rollers and thus can be met only with very considerable technical expense. The thread breakages which occur naturally when the spinning machine is stopped make it possible to reduce the speed slowly, so that it is not difficult to have the ends of the threads remain within the suction region of the spinning chamber but, when the chamber is opened for cleaning of the rotor or for any other reason, the ends of the threads still generally slide out of the thread draw-off channel and thus prevent an automatic reattachment.
For this reason, it has been proposed in Czech Pat. No. 120,497 to provide a movable tube having an ejector nozzle located between a pair of draw-off rollers and a wind-up mechanism of the spinning machine. However, this mechanism is complicated and still does not guarantee the certain repair of the thread breakage. Furthermore, even if the thread repair is successful, there is the possibility of an undesirable change in the local thickness of the thread or excessive twisting thereof.
OBJECT AND SUMMARY OF THE INVENTION
It is a principal object of the invention to provide an open-end spinning machine of the general type described above in which automatic thread attachment is more likely to succeed than in previously known apparatus. The apparatus according to the invention attains this object by providing, among other things, a thread-severing mechanism in association with a thread ejector nozzle.
By cutting off the broken threads, the end of the thread is placed in a predetermined relative position with respect to the ejector nozzle and with respect to the thread exit orifice from the spinning chamber so that the ejector nozzle is capable of blowing this new thread end into the suction region of the spinning chamber while the thread is beinng transported in the reverse direction by the pair of draw-off rollers or in some other way.
For this reason, it is no longer necessary for the ejector nozzle to be movable in the direction of the thread exit orifice of the spinning chamber but, on the contrary, it may be locally fixed and may be attached, for example, to the machine frame or to the spinning chamber itself. If the spinning chamber is movable, for example to permit lifting the rotor shaft from the device belt, as is customary in some open-end spinning machines, then it is suitable to mount the ejector nozzle fixedly on the spinning chamber and thereby maintain its relative position in the spinning chamber constant. In other cases, the ejector nozzle could be attached to the machine frame, in which case its relative position with respect to the draw-off rollers would remain constant.
The apparatus according to the invention is simple in construction and reliable in operation and has many other advantages. The novel construction of the spinning stations according to the present invention permits a particularly simple and reliable simultaneous automatic reattachment of all the threads when the machine has been stopped. It is also possible to provide that, during the normal operation, any thread breakage occurring at a single open-end spinning location can be rapidly and automatically relieved without interrupting the spinning operation at the other locations. This may be done by providing that the processes intended to repair the thread breakage take place independently at each location. Thus the apparatus according to the invention is usable for thread repair independently of its cause and also permits constructional simplifications in the control method and the other details of the spinning location or the spinning machine which uses them.
Since the relative distance of the end of the thread obtained by the thread cutter according to the invention with respect to the fiber collection groove of the rotor is exactly known, the cut thread may be transported backwardly by a predetermined distance which is such that the end of the thread precisely locates with respect to the fibers in the fiber collection groove of the rotor so as to obtain an optimum thread repair which does not introduce any changes in the thickness of the thread produced or any excessive twisting.
It is particularly advantageous if the severing motion of the cutter in the thread cutting mechanism extends over the air outlet orifice of the ejector nozzle. In this manner, the position of the severed thread is particularly favorable because its free end is in an optimum location within the thread channel of the ejector nozzle without extending therefrom and thus is not exposed to the hazard of any displacement which might change the predetermined length and would jeopardize the success of the reattachment process.
It may be preferably provided that the opening of the thread channel in the ejector nozzle remote from the spinning rotor is flared so as to permit engaging a thread end even after it has traversed the thread channel in the ejector nozzle in the direction of the draw-off rollers.
It is also advantageous if the ejector nozzle is embodied as an annular nozzle. Such an embodiment is especially favorable if the mechanism is intended to repair thread breakages occurring from a machine shut-off. For, in that case, all of the ejector nozzles on the machine will be used simultaneously and will therefore require a substantial amount of air flow. Inasmuch as annular nozzles are more efficient than nozzles having a unilateral air supply, the total required air flow is thereby reduced.
The invention will be better understood as well as further objects and advantages thereof become more apparent from the ensuing detailed specification of two preferred embodiments taken in conjunction with the drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a partial, sectional, longitudinal cross section through an open-end spinning mechanism including an apparatus for reversing the thread into the spinning chamber; and
FIG. 2 illustrates a second embodiment of the ejector nozzle for transporting the thread back into the spinning chamber.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to FIG. 1, there is shown a single spinning chamber 1 of an open-end spinning machine which may include a multitude of such spinning chambers. The spinning chamber 1 includes a housing 2 with a removable cover 3. In known manner, not further illustrated, the spinning chamber includes a resolver and supply device which supplies fibers removed from the roving to the spinning rotor 5 in which they are collected by centrifugal force in a collection groove 9 and are pulled off as threads 32 while the spinning rotor rotates. The spinning rotor 5 is driven by a motor, not shown, via a drive shaft 7. A source of vacuum of known type, not shown, constantly aspirates air from the interior 6 of the spinning rotor 5 through the tube 8. Thus, air is constantly aspirated into the thread exit orifice 11 and flows into the interior 6 of the rotor through the thread draw-off channel 10. The channel 10 is formed by a thread draw-off tube fixedly attached to the cover 3 and being part of the spining chamber 1.
During the spinning process, the spun thread is pulled out through the thread channel 10 and the flared opening 11 by a pair of draw-off rollers 12. A tranverse bore 22 in the draw-off tube permits monitoring the presence of a thread in the channel 10 by means of a light sensor 23. Located in the space between the draw-off roller pair 12 and the thread exit orifice 11 of the thread channel 10 is a tube embodied as an ejector nozzle 14 and attached to the housing 2 of the spinning chamber 1 by means of an arm 13. The ejector nozzle 14 has an axial bore 15 which is flared at the side facing the pair of rollers 12. Disposed obliquely with respect to the long axis of the bore 15 is an injection bore 17 which terminates in the bore 15 just below the flared opening 16. A valve 18 permits the admission of compessed air through the bore 17 from a source of air including, substantially, a motor 19 and a pump 20. The ejector nozzle 14 is so located above the thread draw-off channel 10 that its bore passage 15 is aligned with the thread exit orifice 11 and that the air which it expels in normal operation is capable of transporting a thread 32 in the opposite direction of its travel during normal operation of the machine.
Disposed at the end of the ejector nozzle 14 nearest the opening 11 is a thread-severing device 24 which includes a movable cutter 25 and an anvil 26. The cutter 25 is actuated by a piston 28 moving in a cylinder which is provided with compressed air from the air source 19, 20 through a line 29 including a valve 30.
When an open-end spinning machine is stopped, a thread breakage occurs at every one of the individual open-end spinning locations. In order to repair these breakages, the torn ends of the thread must be returned to the interiors of the spinning rotors 5. This may be performed in the following manner. The run-down of the spinning machine to the stopped condition is so controlled that the ends of the threads which are traveling toward the draw-off rollers 12 have not yet reached them when the machine is at a standstill. Rather, each of the threads is located in some, relatively undefined, location between the thread exit orifice 11 and the draw-off rollers 12. In order to prepare the open-end spinning machine for a restarting, the first operation performed is to actuate the vacuum supply of all of the locations through the various tubes 8 and to cause the introduction of compressed air into the bore 17 by actuation of the valves 18. Subsequently, the draw-off rollers 12 are rotated in the reverse direction with respect to normal operation by reversing transmissions or clutches or the like, not shown. Thus, the returned ends of the threads are blown by the ejector nozzles 14 into the thread orifices 11 of the thread draw-off channels 10 and are subject to the prevailing vacuum which pulls them further into the interiors of the spinning chamber. The draw-off rollers 12 are reversed at least far enough so that the ends of the threads 32 at all of the spinning locations are definitely located between the thread severing device 24 and the thread orifices 11. It is advantageous to return the threads even further, so that, when the machine is stopped, any defective pieces of thread near the end which are due to irregular run-down of various machine parts still pass the thread severing mechanism 24. At that time, the draw-off rollers 12 are stopped everywhere and the valves 30 are actuated, thereby causing the thread severing devices 24 to operate. The cutters 25 impinge on their respective anvils 26 and sever the threads 32. The bits of thread cut from each thread are aspirated through the channels 10 and are removed pneumatically.
In order to restart the open-end spinning machine, the draw-off rollers 12 at each location are again moved backwardly so that the reversed threads can be blasted by the ejector nozzles 14 back into the thread exit orifices 11. The draw-off rollers 12 at every location are reversed by the exact amount necessary that the ends of the threads at all locations extend exactly to the fiber collection grooves 9 of the spinning rotors 5 where they combine with the fibers located there and thus repair the thread breakage. At this time, the draw-off rollers 12 may be switched back to normal, forward operation and the ejector nozzles 14 are deactivated by operating the valves 18. The preparation of the machine for restarting and the restarting itself may follow one another without delay. However, it is possible to prepare the machine after a shut-down and to permit it to remain in that condition for an extended period of time although the vacuum and the ejector nozzles 14 would then be made inoperative and only activated again when the machine is to be restarted.
The method for thread repair at an individual spinning station after a thread breakage proceeds in the same manner, although the whole machine would remain operational and the light sensor 23 would sense the breakage and thus initiate only those processes required for repairing the thread breakage at that particular location. It is particularly suitable if, in that event, the thread 32 is transported by a device such as described in the German Offenlegungsschrift No. 20 39 473, especially as illustrated in FIG. 2 therein.
Instead of fastening the ejector nozzle 14 to the spinning chamber 1 as shown, it may also be fastened to the machine frame, which is particularly suitable if the spinning chamber 1 is itself movable within limits.
It will be understood that any other sensor operating under a different principle may be used instead of the light sensor 23 for monitoring the presence of a thread and such a sensor could preferably be a thread tension sensor located between the roller 12 and the ejector nozzle 14.
FIG. 2 illustrates an embodiment of the invention in which the ejector nozzle 14 is an annular nozzle 14' in which the access bore 17 terminates in an annular channel 34 which is continued conically into the bore 15.
The foregoing represents preferred embodiments of the invention, it being understood that many variants thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims.
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An open end spinning machine is provided with individual thread guides for each station. The thread guides direct compressed air along an axial channel in which the thread travels. The air expels the thread in the direction reverse to normal thread travel whenever it is desired to return a broken thread to the spinning chamber and rotor. The apparatus includes a thread cutting mechanism, disposed between the pneumatic thread guide and the spinning chamber, for cutting the thread to a fixed length so that it may be reattached to the fibers in the rotor without discontinuities.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of pending International Application No. PCT/EP03/10463 filed Sep. 19, 2003, which designated the United States and claims priority from pending German Application No. 102 45 449.3 filed Sep. 27, 2002.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to rotating data transmission devices for transmitting digital signals between a plurality of units which are rotatable with respect to each other.
[0004] For the sake of clarity no distinction will be made in this document between a transmission between units that are movable relative to each other, and a transmission between a fixed unit and units movable with respect thereto, because this is only a matter of reference to location and does not affect the manner of operation of the invention. In the same way, no distinction is made between a transmission of signals and energy, because here the mechanisms of operation are the same.
[0005] 2. Prior Art
[0006] With rotatable units such as radar installations or computer tomographs, and also with linearly movable units such as crane and conveyor systems, it is necessary to transmit electrical signals or energy between units movable relative to each other. For this, usually a conductor structure is provided in a first unit, and a corresponding tap in a second unit. In the following exposition the term conductor structures relates to all conceivable forms of conductor structures which are suitable for carrying electrical signals. It also relates to known contacting sliding tracks or slip rings. Of importance to a transmission by means of rotating data transmission devices or linear “slide contact lines” that may also be designed to be non-contacting, is the small distance of the transmission between the units that are movable relative to each other. Thus, a signal may be coupled out optionally by electrical contact, or within a near field of the conductor structures.
[0007] A device corresponding to this is described in the German Laid Open Print DE 44 12 958 A1. Here a signal to be transmitted is fed into a strip line on the first unit, that is disposed alongside a path of movement of the units which are movable relative to each other. The signal is tapped off from the second unit by means of capacitive or inductive coupling.
[0008] The coupling factor of a signal between the two units depends substantially on the distance of the two units from each other. Particularly for spatially extended transmission systems and especially at high speeds of movement, the distances between the movable units cannot be ascertained with any desired accuracy owing to mechanical tolerances. In practice the distances may vary in a range from direct contact up to a few centimeters, preferably between 0.01 mm and 10 mm. Therefore the coupling factor will frequently vary with the position of the two units with respect to each other, the speed (e.g. by causing vibrations), and other parameters of influence. At the same time the signal amplitude at the input of the receiver varies. This results in changes of the signal with conventionally constructed receivers, which will appear, for example, as an increased jitter, or even bit errors. Similarly, changes of the resistance to interference result.
[0009] An improvement of the transmission properties is provided by a device published in DE 197 00 110 A1, which has a conductor structure with filter properties, instead of a strip transmission line. Basically, however, the problems remain.
[0010] In U.S. Pat. No. 6,433,631 B2 a device for regulating the input level at a receiver is disclosed. For this, the signal amplitude outputted by a preamplifier is measured, and an attenuating member provided to precede the preamplifier is controlled according to this signal amplitude. The disadvantage of this arrangement is that with it only a signal having a constant amplitude is placed at the disposal of the receiver.
[0011] The disadvantage of the devices corresponding to prior art resides in an as yet inadequate resistance to interference. Thus, the transmitted signal levels in the line can be increased in order to improve the resistance to interference. With this, however, an undesired radiation of high-frequency signals increases. With a reduction of the transmitted signal levels, the radiation becomes less, but the immunity to interference scattered in from the outside also becomes less.
BRIEF SUMMARY OF THE INVENTION
[0012] The problem arises of designing a rotating data transmission device for electrical signals which avoids the above drawbacks and, in particular, has a high resistance to interference and therefore a high transmission quality of the signals.
[0013] Another problem of the invention is that of providing a method for electrically transmitting broadband digital signals using the rotating data transmission device.
[0014] In accordance with the invention the first of the above problems is solved with a rotating data transmission device for electrical transmission of broadband digital signals between at least one first unit and at least one second unit disposed to be rotatable relative to the first unit, the at least one first unit comprising:
a data source for generating a serial data stream; a transmitter for generating electrical signals from the serial data stream of the data source; and a transmission conductor structure for carrying the electrical signals generated by the transmitter;
and the at least one second unit comprising:
a receiving antenna for tapping-off electrical signals in a near field of the transmission conductor structure; a receiver for receiving signals tapped-off by the receiving antenna; and a data sink for further processing the signals received by the receiver;
wherein the first unit further comprises:
an encoder provided between the data source and the transmitter for digitally encoding the data stream and converting the digitally encoded data stream so that a power of electrical signals generated by the transmitter in given spectral ranges is optionally increased or lowered; and
the second unit further comprises:
a decoder provided between the receiver and the data sink for restoring, from signals of data encoded by the encoder and received by the receiver, data in an original form as issued by the data source.
[0023] In accordance with the invention the first of the above problems is also solved with a rotating data transmission device for electrical transmission of broadband digital signals between at least one first unit and at least one second unit disposed to be rotatable relative to the first unit, the at least one first unit comprising:
a data source for generating a serial data stream; a transmitter for generating electrical signals from the serial data stream of the data source; and a transmission conductor structure for carrying the electrical signals generated by the transmitter;
and the at least one second unit comprising:
a receiving antenna for tapping-off electrical signals in a near field of the transmission conductor structure; a receiver for receiving signals tapped-off by the receiving antenna; and a data sink for further processing the signals received by the receiver;
wherein at least one filter, assigned optionally to the transmitter or the receiver, is provided to effect matching to transmission characteristics of a data path between the transmitter and the receiver.
[0030] In accordance with the invention the second of the above problems is solved with a method for electrically transmitting broadband digital signals between at least one first unit and at least one second unit disposed to be rotatable relative to the first unit in a rotating data transmission device, comprising the steps of:
generating a serial data stream from a data source on the at least one first unit; generating electrical signals from the serial data stream with a transmitter on the at least one first unit; and carrying the electrical signals generated by the transmitter in a transmission conductor structure on the at least one first unit; and tapping-off electrical signals in a near field of the transmission conductor structure with a receiving antenna on the at least one second unit; receiving signals tapped-off by the receiving antenna with a receiver on the at least one second unit; and further processing the signals received by the receiver in a data sink on the at least one second unit;
the method comprising the further steps of:
encoding the signals to be transmitted on the at least one first unit so that a spectral power density of the signals is optionally increased or decreased in given spectral ranges; and decoding the signals received on the at least one second unit to restore data in an original form as issued by the data source.
[0039] A device in accordance with the invention serves for transmitting digital signals between at least two units that are rotatable relative to each other, preferably as a rotating data transmission device, as employed for example in computer tomographs. Of course, one or a plurality of units may be disposed on each side of the movement. For simplification of the representation, reference is here made exclusively to a second unit that is rotationally movable relative to a first unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] In the following the invention will be described by way of example, without limitation of the general inventive concept, on examples of embodiment with reference to the drawings.
[0041] FIG. 1 schematically shows in general form a rotating data transmission device in accordance with the invention.
[0042] FIG. 2 schematically shows in general form a device for linear transmission in accordance with the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0043] In FIG. 1 a particularly advantageous embodiment of a rotating data transmission device in accordance with the invention is illustrated. Data of a data source 1 are transmitted via an encoder 7 and a transmitter 2 to a transmission conductor structure 3 of circular configuration. The transmission conductor structure is disposed along a path of movement indicated by a directional arrow 9 , and carries the signals fed in from the transmitter. A receiving antenna 4 makes it possible to tap-off signals of a near field of the transmission conductor structure. The signals tapped-off by the antenna are conducted via a receiver 5 and a decoder 8 to a data sink 6 .
[0044] FIG. 2 shows a device for linear transmission. As the geometry of the transmission means or of the track of movement basically does not affect the configuration used in the invention, the reference symbols correspond to those of FIG. 1 .
[0045] A data source 1 for generating a serial data stream, such as, for example, a prior art parallel/series converter is assigned to the first unit. Furthermore, a transmitter 2 is provided for generating electrical signals from the serial data stream of the data source for transmission via a transmission conductor structure 3 . A receiving antenna 4 for tapping off electrical signals in the near field of the transmission conductor structure is assigned to the second unit. The electrical signals of the receiving antenna are supplied to a data sink 6 via a receiver 5 for further processing of the signals.
[0046] Now, according to the invention an encoder 7 is provided between the data source 1 and the transmitter 2 . This encoder is adapted to convert the digital encoding of the data stream so that the data can be transmitted via the transmitter 2 , the transmission conductor structure 3 , the receiving antenna 4 and also the receiver 5 with a minimum of errors.
[0047] According to the nature of the invention, the encoder is provided in the electrical signal path between the data source 1 and the transmitter 2 . Of course, this encoder may also be disposed in the transmitter 2 .
[0048] Furthermore, a decoder 8 for decoding the signals encoded by the encoder 7 is assigned to the second unit between the receiver 5 and the data sink 6 . With this decoder the encoding operation of the encoder is reversed, so that the signals supplied to the data sink correspond to the data stream of the data source 1 . Of course, the decoder can also be disposed in the receiver 5 . Thus, for optimum transport of the data along the data path, the coding is completely transparent for the data source or the data sink.
[0049] According to the invention, a conversion of the spectral properties of the data stream is effected by the encoding of the data stream by means of the encoder 7 . Thus, the encoding is effected in such manner that the power of the signal in given spectral ranges is optionally increased or decreased. By a conformation of the spectral properties of the signals, the transmission quality can be conformed to the frequency response of the remaining transmission path, and also to any interference sources or components susceptible to interference that may be present.
[0050] If the data path between the transmitter and the receiver has a particularly high attenuation, for example in one or a plurality of known frequency ranges, then the encoding can now be designed advantageously so that this frequency range is not used for transmission. In the opposite case of frequency ranges having a particularly low attenuation, a maximum can be placed within these frequency ranges by suitable encoding.
[0051] If external interference sources impairing the transmission of the signals are present, then the encoding is effected in advantageous manner so that optionally these frequency ranges are not used. As an alternative to this, an especially high amplitude could be emitted within these frequency ranges.
[0052] If components particularly susceptible to interference are present outside the data path, then the spectrum of the transmitted signal can be conformed by the encoding so that only signals of low levels are emitted in the frequency ranges of high susceptibility to interference. Basically, it is here also possible to broaden the known line spectrum of digital signals with a suitable encoding, in order to meet the limiting values measured in accordance with valid EMC Standards.
[0053] The encoding is effected in advantageous manner so that the transmitted signal is free from d.c.
[0054] In another embodiment of the invention the kind of encoding can be set dynamically, so that in advantageous manner it can adapt to changes caused by the movement. For this, advantageously a control unit with means for determining the current operational condition and correspondingly presetting the coding for the encoder is provided. Thus, for example, the coding may be preset in dependence upon position. A position sensor could signal the relative position of the units rotatable with respect to each other and preset a suitable coding. Similarly, a time-dependent coding can be preset. This is of particular advantage with a constant speed of rotation, because here again an assignment to the position is possible.
[0055] Another embodiment of the invention provides for the encoding function of the encoder to be varied in dependence upon time, in order to compensate for the effects of time-dependent interference sources. Thus, for example, encoding may be adapted according to the interference peaks of a current supply, an X-ray tube or an electric motor.
[0056] Another embodiment of the invention provides for the coding operation of the encoder to be adapted in dependence upon electrical measurement parameters. Thus, for example, a measurement parameter may be determined according to an interference level of the transmission means. This measurement parameter can now optionally be utilized, analogously to conforming particular spectral components, so that amplitudes of spectral components of a wanted signal transmitted in frequency ranges subject to interference are increased. Similarly, this measurement parameter may be utilized for signaling a shift of spectral components of the wanted signal into ranges not subject to interference. Furthermore, the measurement parameter may be also utilized for effecting a switch-over to a different spectral amplitude distribution of the wanted signal.
[0057] According to the invention a dynamic adaptation may be effected at the beginning of a transmission, the adaptation or settings performed at the beginning being maintained for the duration of the transmission. Similarly, dynamic adaptation during the entire duration of the transmission is also possible.
[0058] In another embodiment of the invention the encoder is adapted to introduce additional redundancy into the data stream. In the case of transmission errors, further corrections of the information of the data stream are made possible by this additional redundancy. These corrections may now be performed optionally by the data sink, but preferably by a decoder.
[0059] In another embodiment of the invention the encoder is adapted to increase the data rate of the serial data stream and therewith create space for additional redundant information. In an advantageous manner this conversion of the data rate, or optionally a previously described conversion of the coding or the packet information, is effected by converting the serial data stream of the data sources to parallel data words that may be modified easily, and also by a subsequent conversion to a changed serial data stream for transmission.
[0060] Another device according to the invention comprises an encoder which encodes or enciphers signals to be transmitted in order to increase security. For this, in accordance with the security requirements, a shorter or longer key can be used. Suitable means for deciphering can then be provided optionally in the data sink or in the decoder.
[0061] Another embodiment of the invention provides that means for timing recovery be provided optionally in the encoder 7 or the decoder 8 . Furthermore, means for timing recovery may be provided at an optional place along the data path. By means of the timing recovery of a signal a synchronization of the signal with a timing of constant frequency is effected, which is usually obtained from the data stream with the aid of a PLL. The profile of the signal can be substantially improved thereby. Thus, the regenerated signal will again have clear slopes with reduced jitter, and thus an increased opening of eye pattern.
[0062] In another embodiment of the invention at least one filter is assigned optionally to the transmitter 2 or the receiver 5 . This filter serves to effect matching to the transmission characteristics of the data path between the transmitter and the receiver. Thus, frequency-dependent amplitude and phase responses can be corrected, particularly on the receiver side. In addition, external interference can be reduced with filters of this kind.
[0063] Another advantageous embodiment of the invention consists in the filter being dynamically adjustable. Particularly with movable units, the transmission characteristic changes dynamically during a movement. This can be compensated by dynamic filter adjustment. A filter of this kind can be controlled, for example, by a microcontroller or by a simple automatic control circuit.
[0064] In another advantageous embodiment the device is designed to be self-learning or adaptive. This means that it adapts to operating states dynamically, in particular during movement. This can be effected, for example, by determining certain operating parameters such as bit error rate, signal amplitude etc., and subsequently adjusting the encoder, or the decoder, or the filters. It is therefore particularly expedient to use a fuzzy logic controller here. Thus, for example, the redundancy or the data rate can be set as a function of the transmission errors. This means that with a large number of transmission errors, a higher redundancy, for example, is provided. Particularly with rotating movements, and especially at constant speed, it is of advantage to store the transmission function via the rotation, and to perform an adjustment of the encoder, or the decoder, or the filters in suitable dependence on time or position. Of course, this is possible also for linear movements, provided that information on the position is available.
[0065] A method of the invention for broadband transmission of digital signals using a device according to the invention provides for the signals to be digitally encoded so that the spectral power density of the signals in given spectral regions is optionally raised or lowered.
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A device for transmission of digital signals between two units movable relative to each other, particularly with non-contacting rotating data transmission devices, comprises an encoder on a transmitter side along a signal path for conforming a coding of the digital signals to transmission characteristic of a transmission path, so that a given spectral distribution of signals is attained. An optional decoder on a receiver side restores original signals, so that the coding remains concealed, but a substantially more reliable transmission is achieved.
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PRIORITY APPLICATION
[0001] This application claims priority benefit of U.S. Provisional Patent Application No. 61/458,070, filed Nov. 17, 2010, titled “HAND GRIP FOR FOREARM STOCK OF RIFLES, MUZZLELOADERS, AND CROSSBOWS” having Douglas Sweet named as the inventor and which is incorporated herein by references as, if set forth in full below.
[0002] A portion of the disclosure of this patent document and its figures contain material subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, but otherwise reserves all copyrights whatsoever.
BACKGROUND
[0003] The invention relates to a firearm. More specifically, it pertains to a secondary grip for a rifle or for another shoulder firearm, such as a muzzleloader. This secondary grip is permanently or temporarily attached or affixed to the firearm to improve stability or control when aiming the firearm.
[0004] The accuracy of firing a conventional firearm depends upon the ability of a user holding the firearm to maintain his or, her hand and/or wrist in a steady position while aiming.
DESCRIPTION OF THE DRAWINGS
[0005] The exemplary embodiments, objects, uses, advantages, and novel features are more clearly understood by reference to the following description taken in connection with the accompanying figures wherein:
[0006] FIG. 1 illustrates a rifle with an attached secondary grip attached at a 90-degree angle in accordance with some of the exemplary embodiments of the present invention.
[0007] FIG. 1 a illustrates an exploded perspective side view of the secondary grip of FIG. 1 showing details of a slide-and-lock mechanism according to some of the exemplary embodiments of the present invention.
[0008] FIG. 2 shows a perspective side view of secondary grip affixed beneath the barrel of a rifle according to exemplary embodiments of the present invention.
[0009] FIG. 2 a illustrates an exploded perspective side view of the secondary grip of FIG. 2 showing details of an alternate attachment to the barrel of the rifle according to exemplary embodiments of the present invention.
[0010] FIG. 3 illustrates a perspective side view of a stacked back secondary grip according to some of the embodiments of the present invention.
[0011] FIG. 4 shows a perspective side view of a secondary vertical grip according to some of the exemplary embodiments of the present invention.
[0012] FIG. 5 is a perspective side view illustrating three positioning points of a rifle that includes the secondary grip according to some of the embodiments of the present invention.
DESCRIPTION
[0013] The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any configuration or design described herein as “exemplary” is not necessarily construed as preferred or advantageous over other configurations or designs. This invention is described more fully hereinafter with reference to the accompanying drawings and two included prototypes that depict some of the exemplary embodiments. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Moreover, all statements herein reciting embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future (i.e., any elements developed that perform the same function, regardless of structure).
[0014] Referring now to FIGS. 3 and 4 , two exemplary secondary grips 300 and 400 are shown from a perspective side view. Each of these secondary grips 300 and 400 are adaptable for a first or thumbs up hand position. According to FIG. 3 , the secondary. grip 300 can have a flat top ledge 310 that provides an upper lip that may be helpful in positioning one's grip of secondary grip 300 . Alternatively, as shown in FIG. 4 , the secondary grip may include a sloped or slightly indented top ledge 410 to provide what might feel like a seamless grip. Secondary grip 300 comprises a stacked-back design indicated by a degree of angle x relative to the axes shown on FIG. 3 . Secondary grip 300 includes three ledges 321 , 323 , and 324 separating two internal cavities 322 and 324 for finger or digit placement. The first ledge 321 is farther forward than the second 323 and third 324 ledges. Furthermore, secondary grip 300 includes a bottom portion 325 that allows for an-optional, additional surface for a user to place his or her pinky finger, thus allowing'for one's hand to squeeze the grip 300 by pressing one's pinky (not shown) into the grip 300 in opposition to one's palm (not shown); or by allowing pinky finger and bottom of hand furthest from thumb to rest on ground, shooting table, or barrel mount, as not to transfer shock to said object beneath firearm and secondary grip.
[0015] Secondary grip 400 of FIG. 4 includes a body portion at angle y that is complimentary to a 90-degree angle. All three ledges 422 , 424 , 426 separating internal cavities 421 , 423 , and 425 are nearly vertically aligned in. relation to one another. Accordingly, the configuration of these nearly, vertically aligned ledges 422 , 424 , 426 and cavities 421 , 423 , 425 may provide an improved grip for a user having smaller hands (not shown). Both secondary grips 300 and 400 may comprise a smooth surface, a riveted, textured or rough surface or combinations thereof. The grips may be made out of natural materials (e.g., wood, metals, etc.), man-made materials (e.g., plastic components) and combinations thereof.
[0016] FIGS. 1 , 1 a , 2 and 2 a illustrate two different secondary grips 110 and 210 that depict two different mounting options as well as two different angles for mounting the secondary grips 110 and 210 . Referring now to FIG. 1 , a secondary grip 110 is from a perspective side view mounted on a firearm 100 . Firearm 100 represents a rifle. FIG. 1 displays the grip 110 mounted at a 90-degree angle.
[0017] Firearm 100 includes a barrel 150 and a barrel gunstock forearm 140 . The shroud 140 is for protection from any heat transferred from the barrel 150 , as well as for hand placement to stabilize and control the firearm.
[0018] Rifle 100 includes secondary grip 110 positioned along the barrel shroud 140 from a point where the barrel 140 meets the shroud 150 and where the barrel 140 reaches the trigger 160 . The reference line 130 shows the surface range where the secondary grip 110 may be mounted.
[0019] The secondary grip 110 in FIG. 1 a mounts by a slide-and-lock mechanism 120 that includes a groove 122 along the barrel shroud 140 that mates with a slide portion 124 of the secondary grip 110 and includes a lock mechanism 126 to securely position the mated hardware.
[0020] In considering the manner of orientation depicted in FIGS. 1 , 1 a , 2 and 2 a , the invention grip has two different mounting options as well as two different possible mounted angles. FIG. 1 displays the grip 110 mounted at a 90-degree angle. FIG. 2 illustrates a secondary grip 210 positioned directly underneath the barrel shroud 220 . FIG. 2 a depicts an alternate means for attaching secondary grip 210 than the slide and lock embodiment shown in FIG. 1 a . According to FIG. 2 a , the barrel shroud 220 has apertures 224 to secure screws 222 from which to affix the secondary grip 210 . The barrel shroud 220 includes apertures 224 to secure the screws 222 . These apertures along a surface of the barrel shroud 220 are in the approximate range indicated by reference line 230 . Still further, the top surface area of the secondary grip 210 may also have an epoxy or glue (not shown) that is used in conjunction with the screws 222 and apertures 224 . Either of the mounting options shown in. FIG. 1 or FIG. 2 may be selected by a user. The choices provide for greater range of options for the individual and his or her preferences.
[0021] Referring now to FIG. 5 , a user is positioning a firearm with a secondary grip 510 according to some of the embodiments. As shown, there are three points of contact that include a forward hand 570 on the secondary grip 510 , a rear hand shown on a trigger portion 560 , and a complimentary should 550 , thus aiding the user to better secure and stabilize the firearm in use. By placing the secondary grip 510 on the ground for single arm operation all three points of contact are maintained and thus still able to keep increased stability.
[0022] According to some of the embodiments, the grips described herein may be manufactured from man-made materials, natural materials and combinations thereof. For example, the grips may include rubber, wood, and synthetic material. Still further, the grips may be solid, hollowed, or semi-hollowed components. The grips provide an additional position to secure the firearm. Having a forward secondary grip may provide improved stabilization, control, and/or increased, accuracy. A forward secondary grip might also aid in aiming the firearm and maintain improved rear arm stability. The method of attaching or affixing the secondary grip may include, but is not limited to, gluing, apertures and screws, molding technologies, using a slide and locking mechanism, combinations thereof, as well as other equivalent means. The different means of attachment enable the location of the secondary grip at a custom placement that is best suited for each individual user taking into account that user's arm length, grips, and other considerations. An adjustable secondary grip location could allow for several different hand placements both rotationally and longitudinally. The placement of the secondary grip can be directly underneath the barrel of the firearm or alternatively tilted at an angle relative to the barrel shroud of the firearm.
[0023] While the description of the invention is particular to material, shape, and method of affixing to a firearm, it should be. understood that this detailed description is by way of example only, and the protection granted is to be limited only within the spirit of the invention. For example, the secondary grip is applicable to both right-handed and left-handed users. Alternatively, if a user only has one arm or if the user opts to use one arm and the secondary grip, then the secondary grip may be mounted or rested on the earth or in barrel mounts for aiming.
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The invention includes a secondary grip for a rifle or for another shoulder firearm, such as a muzzleloader. This secondary grip is permanently or temporarily attached or affixed to the firearm to improve stability or control when aiming the firearm. Some embodiments disclose a stacked back secondary grip that attaches in vertical alignment with the barrel. Alternate embodiments disclose a secondary grip at a 90 degree angle.
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This application is based on and claims priority of provisional application Ser. No. 60/512,633, filed Oct. 20, 2003
U.S. Pat. No. 5,024,031 hereby incorporated by reference as if fully disclosed herein teaches methods for constructing transformable truss-structures in a variety of shapes. The teachings therein have been used to build structures for diverse applications including architectural uses, public exhibits and unique folding toys.
One basic embodiment disclosed in U.S. Pat. No. 5,024,031 are loop-assemblies comprised of scissor-pairs which are in turn comprised of angulated strut elements. Such loop-assembles are foldable in the sense that they expand and contract in a synchronized fashion when a relative motion is imposed between any two links.
BACKGROUND OF THE INVENTION
SUMMARY OF THE INVENTION
In accordance with the present invention, a new way to create loop assemblies comprised of links pivotally joined end to end such that the motion of the assembly is provided. The synchronization may be accomplished in a variety of methods such as gears, belts or pulleys. All methods have in common the linking of every second link in the loop assembly such that the relative rotation of every second link is synchronized.
One key benefit of the invention is a reduction in the number of individual elements as compared with those structures disclosed in U.S. Pat. No. 5,024,031. Rather than all links being “doubled” in the form of scissor-pairs, a single loop of links suffices. The addition of gears or pulleys represents only minor additional material.
The invention has a second useful feature as well. For structures disclosed in '031, they move between a contracted state and expanded state. As the structure expands, its members rotate approximately ninety degrees. When the structure is fully expanded, the members are prevented from rotating further because the hub elements contact each other.
According to the current invention, structures are disclosed such that its members rotate approximately one hundred and eighty degrees. Thus, the structure starts in a contracted state, where its members are in a radial configuration, to an expanded state where its members form an extended loop, and then it can be continuously folded again so that it reaches a second, unique contracted state.
This unusual ability to “flip” between two unique folded states allow for structures to be built that display a pleasing visual transformation.
A third useful feature of the current invention is that it provides a mechanism whereby a circular ring that has flight on characteristics can transform into a boomerang.
It is thus an object of the invention to provide an improved ring linkage system.
Another object of the invention is to provide a linkage system whose motion is synchronized.
Yet a further object of the invention is to provide an improved linkage having a plurality of links in geared contact with one another.
Other objects and advantages of the invention will, in part, be obvious and will, in part, be apparent from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the invention, reference is made to the following description, taken in connection with the accompanying drawings in which:
FIG. 1 is a perspective view of three links pivotally connected to each other and made in accordance with the invention;
FIG. 2 is a plan view of the three links of FIG. 1 in a partially folded condition;
FIG. 3 is a plan view of the three links of FIG. 1 in a partially extended condition;
FIG. 4 is a plan view of the three links of FIG. 1 in a third angled condition;
FIG. 5 is a perspective view of a first embodiment of the linkage assembly of the invention;
FIG. 6 is a plan view of the linkage of FIG. 5 ;
FIG. 7 is also a plan view of the linkage assembly of FIG. 5 and similar to FIG. 6 ;
FIG. 8 is a plan view of the linkage assembly of FIG. 5 shown in a different position;
FIG. 9 is a plan view of the linkage assembly of FIG. 5 in a folded condition;
FIG. 10 is a plan view of the linkage assembly of FIG. 5 and similar to FIG. 9 ;
FIG. 11 is an exploded perspective view of a second embodiment of the linkage assembly of the invention;
FIG. 12 is a perspective view of the linkage assembly of FIG. 1 in a closed position;
FIG. 13 is a perspective view of the assembly of FIG. 11 in a partially open condition;
FIG. 14 is a perspective view of the linkage assembly of FIG. 11 in a fully open condition;
FIG. 15 is a plan view of the linkage assembly of FIG. 11 ;
FIG. 16 is a plan view of the linkage assembly of FIG. 11 in a partially open condition;
FIG. 17 is a plan view of the linkage assembly of FIG. 11 in a fully open condition;
FIG. 18 is a plan view of the linkage assembly of FIG. 11 in a second partially open condition;
FIG. 19 is a plan view of the linkage assembly of FIG. 11 in a second closed condition;
FIG. 20 is a plan view of a third embodiment of a linkage assembly in accordance with the invention;
FIG. 21 is a plan view of the linkage assembly of FIG. 20 in a partially open condition;
FIG. 22 is a plan view of the linkage assembly of FIG. 20 in a fully open condition;
FIG. 23 is an exploded perspective view of covering panels suitable for attaching to the linkage assembly of FIG. 20 ;
FIG. 24 is a perspective view showing the covering panels of FIG. 23 forming a ring;
FIG. 25 is a perspective view showing the covering panels of FIG. 23 in a partially open condition;
FIG. 26 shows the covering panels of FIG. 23 in a fully closed condition;
FIG. 27 is a perspective view of another linkage assembly made in accordance with the invention:
FIG. 28 is a plan view of the linkage assembly of FIG. 27 in an extended condition;
FIG. 29 is a plan view of the linkage assembly of FIG. 27 in a partially angled condition;
FIG. 30 is a plan view of the linkage assembly of FIG. 27 in a folded condition;
FIG. 31 is a plan view of still another embodiment of the linkage assembly made in accordance with the invention;
FIG. 32 is a plan view of the linkage assembly of FIG. 31 in a partially open condition;
FIG. 33 is a plan view of the linkage assembly of FIG. 31 in a fully open condition;
FIG. 34 is a perspective view of yet a further embodiment of the linkage assembly of the invention;
FIG. 35 is a plan view of the linkage assembly of FIG. 34 ;
FIG. 36 is a plan view of the linkage assembly of FIG. 34 in a partially folded condition;
FIG. 37 is a plan view of the linkage assembly of FIG. 34 in an alternative folded condition;
FIG. 38 is a plan view of yet another embodiment of a linkage assembly of the invention;
FIG. 39 is a plan view of a linkage assembly of FIG. 38 in a partially closed condition;
FIG. 40 is a top plan view of a further embodiment of a linkage assembly of the invention;
FIG. 41 is a top plan view showing the linkage assembly of FIG. 40 in a different position; and
FIG. 42 is a top plan view showing the linkage assembly of FIG. 40 in yet another position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a perspective view of mechanical assembly 10 consisting of three links 12 , 14 and 16 which are pivotally connected to each other end-to-end. Link 12 has two ends 11 and 13 each of which has a geared profile. Similarly the ends of link 16 has two ends 15 and 17 ends each of which have a geared profile.
Gear 18 is pivotally connected to link 14 . Gear end 13 engages with gear 18 ; likewise gear end 15 engages with gear 18 .
FIG. 2 shows a plan view of assembly 10 . The two dashed lines shown passing through the end pivots of links 12 and 16 form an angle 15 between them.
FIG. 3 shows assembly 10 in a different position, links 12 and 16 having been rotated relative to link 14 . Links 12 and 16 form an angle 15 between them, said angle being unchanged from the angle shown in FIG. 2 . The reason that this angle remains unchanged is because gear 18 synchronizes the relative motion of links 12 and 16 .
FIG. 4 shows assembly 10 in a third position. The relative angle between links 12 and 16 remains unchanged.
FIG. 5 shows a perspective view of linkage 30 which is comprised of eight links 31 , 32 , 33 , 34 , 35 , 36 , 37 and 38 which are pivotally connected end to end. Each link terminates with two gear ends. Gear 41 is pivotally attached to link 31 . Likewise gears 42 , 43 , 44 , 45 , 46 , 47 and 48 are respectively pivotally attached to links 32 , 33 , 34 , 35 , 36 , 37 and 38 .
The gear ends of link 31 engage with gears 48 and 42 . Likewise the gear ends of all the links engage with the gears which are pivotally attached to their neighboring links.
FIG. 6 shows linkage 30 in plan view. Links 31 and 33 are pivotally connected to link 32 and their respective gear ends are engaged with gear 42 . The dashed lines passing through the end pivots of links 31 and 33 form an angle 51 between them. Similarly the dashed lines passing through link pairs 33 - 35 , 35 - 37 and 37 - 31 form angles 52 , 53 and 54 respectively.
FIG. 7 shows linkage 30 in the same view as FIG. 6 , with angles 55 , 56 , 57 , 58 being formed by the dashed lines passing through link pairs 32 - 34 , 34 - 36 , 36 - 38 and 38 - 32 respectively.
FIG. 8 shows linkage 30 in a different position. The angle 51 formed by the dashed lines passing through links 31 and 33 is unchanged from FIG. 6 . Likewise, the similarly formed angles 52 , 53 and 54 are unchanged from those formed in FIG. 6 .
FIG. 9 shows linkage 30 in a folded position. The four angles 51 , 52 , 53 and 54 respectively formed between link pairs 31 - 33 , 33 - 35 , 35 - 37 and 37 - 31 are unchanged from those formed in FIGS. 6 and 7 .
FIG. 10 shows linkage 30 in the same view as FIG. 9 . The four angles 51 , 52 , 53 and 54 respectively formed between link pairs 32 - 34 , 34 - 36 , 36 - 38 and 38 - 32 are unchanged from those formed in FIGS. 6 and 7 .
Thus linkage 30 demonstrates a key feature of the invention: the relative angle between two links that are each connected to a common link between them, and that are synchronized by a gear that is connected to said common link, will form a constant and unchanging angle for any given position of the linkage.
In FIG. 11 , an assembly 80 is shown in exploded view. Assembly 80 is comprised of eight links having a polygonal profile, one layer comprised of links 61 , 63 65 and 67 ; a second layer comprised of links 62 , 64 , 66 and 68 . Additionally eight gears 71 , 72 , 73 , 74 , 75 , 76 , 77 and 78 are pivotally connected respectively to the eight links.
FIG. 12 shows assembly 80 in a closed position whereby links 61 , 63 , 65 and 67 form a continuous surface. FIG. 13 shows assembly 80 in a partially open position and FIG. 14 shows 80 in its fully opened position.
FIG. 15 shows a assembly 80 in plan view. An image of a triangle 81 has been printed on links 61 , 63 , 65 and 67 . FIG. 16 and FIG. 17 show assembly 80 in a partially opened and fully opened position respectively.
FIG. 18 shows assembly 80 in a second partially opened position whereby the links have been rotated past their fully opened position. FIG. 19 shows assembly 80 in its second closed position. A second image of a square 82 has been printed on links 61 , 63 , 65 and 67 . Thus, assembly 80 is shown to have the capability to “flip” between two separate images.
FIG. 20 shows an assembly 100 comprised of six links 101 , 102 , 103 , 104 , 105 and 106 which are pivotally connected end to end. Three gears 112 , 114 and 116 are pivotally attached to links 102 , 104 and 106 respectively. Angles 91 , 92 and 93 are shown formed between link-pairs 105 - 101 , 101 - 103 and 103 - 105 respectively.
FIG. 21 shows assembly 100 in a partially opened position. The angles between link pairs 105 - 101 , 101 - 103 and 103 - 105 are respectively 91 , 92 and 93 being unchanged from FIG. 20 .
FIG. 22 shows assembly 100 in a fully opened position. The angles between link pairs 105 - 101 , 101 - 103 and 103 - 105 are respectively 91 , 92 and 93 being unchanged from FIGS. 20 and 21 .
FIG. 23 shows assembly 100 in exploded view with three covering panels 122 , 124 and 126 shown. FIG. 24 shows these covering panels attached to links 102 , 104 and 106 respectively such that a ring is formed when 100 is in its fully opened position. Said ring has certain flying characteristics for straight sustained flight when thrown in a spinning motion.
FIG. 25 shows assembly 100 with its attached covering panels shown in a partially opened position. FIG. 26 shows assembly 100 in its fully closed position such that it forms the profile of a three pronged shape. Said shape has certain flying characteristics similar to a boomerang when thrown with a spin such that it flies in a loop returning to the thrower.
FIG. 27 shows a perspective view of mechanical assembly 120 consisting of three links 122 , 124 and 126 which are pivotally connected to each other end-to-end. Link 122 has two ends 121 and 123 each of which have an attached pulley. Similarly, the ends of link 126 has two ends 125 and 127 ends each of which have an attached pulley.
Belt 130 engages pulley ends 123 and 125 . FIG. 28 shows a plan view of assembly 120 . The two dashed lines shown passing through the end pivots of links 122 and 126 form an angle 128 between them.
FIG. 29 shows assembly 120 in a different position, links 122 and 126 having been rotated relative to link 124 . Links 122 and 126 form an angle 128 between them, said angle being unchanged from the angle shown in FIG. 28 . The reason that this angle remains unchanged is because belt 130 synchronizes the relative motion of links 122 and 126 .
FIG. 30 shows assembly 120 in a third position. The relative angle 128 between links 122 and 126 remains unchanged.
FIG. 31 shows a loop assembly 200 comprised of sixteen links, each having two pulley ends, every other link being connected via a belt such that a constant angle 210 is formed between every other link. FIG. 32 shows assembly 200 in a different position where the angle 210 between every second link is unchanged.
FIG. 33 shows assembly 200 in its fully opened position, the angle 210 between every second link remaining unchanged.
FIG. 34 shows a perspective view of mechanical linkage assembly 320 consisting of three links 322 , 324 and 326 which are pivotally connected to each other end-to-end. Link 322 has two ends 321 and 323 each of which have an attached bevel gear. Similarly the ends of link 326 has two ends 325 and 327 ends each of which have a geared an attached bevel gear.
Gear assembly 330 comprised of two bevel gears fixed to a common shaft is pivotally connected to link 324 and engages bevel gear ends 323 and 325 . FIG. 35 shows a plan view of assembly 320 . The two dashed lines shown passing through the end pivots of links 322 and 326 form an angle 328 between them.
FIG. 36 shows assembly 320 in a different position, links 322 and 326 having been rotated relative to link 324 . Links 322 and 326 form an angle 328 between them, said angle being unchanged from the angle shown in FIG. 35 . The reason that this angle remains unchanged is because gear assembly 330 synchronizes the relative motion of links 322 and 326 .
FIG. 37 shows assembly 320 in a third position. The relative angle 328 between links 322 and 326 remains unchanged.
FIG. 38 shows a linkage or loop assembly 400 comprised of six links, each having two bevel gear ends, every other link being connected via a bevel gear assembly such that a constant angle 410 is formed between every other link.
FIG. 39 shows assembly 200 in a different position where the angle 410 between every second link is unchanged.
FIG. 40 shows an assembly 500 which is comprised of four links 515 , 525 , 535 and 545 each having two gear ends, four links 510 , 520 , 530 and 540 having a triangular profile and three pivots each. Four gears 512 , 522 , 532 and 542 are pivotally attached to links 510 , 520 , 530 and 540 respectively. Assembly 500 further includes a central link 505 which is pivotally connected to the third pivot each of links 510 , 520 , 530 and 540 . Central link 505 serves to assist in the synchronization of assembly 500 .
An angle 550 is formed between links 515 and 525 . Similarly, angles 560 , 570 and 580 are formed between link-pairs 525 , 535 ; 535 , 545 ; and 545 , 515 respectively.
FIG. 41 shows assembly 500 in a different position. The angle 550 formed between links 515 and 525 is unchanged from FIG. 40 . Similarly, angles 560 , 570 and 580 are formed between link-pairs 525 , 535 ; 535 , 545 ; and 545 , 515 , and are unchanged from FIG. 40 .
FIG. 42 shows assembly 500 in another position. Angles 550 , 560 , 570 and 580 are formed between link-pairs 515 , 525 ; 525 , 535 , 535 , 545 ; and 545 , 515 , and are unchanged from FIGS. 40 and 41 .
It will thus be seen that the objects set forth above, among those made apparent from the proceeding description, are efficiently attained, and, in since certain changes may be made in the construction of the inventive structure without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description and 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 general and specific features of the invention described herein and all statements of the scope of the invention which, as a matter of language, might be said to fall there between.
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A ring linkage is hereby disclosed that is comprised of at least six links, each link having at least two pivots located proximate to their ends, said links being arranged in a loop whereby each link is pivotally attached via its end pivots to two neighboring links.
The motion of the linkage is synchronized by a multiplicity of mechanical elements that serve to synchronize the relative rotation of the links in the assembly such that when a given link rotates by an angle, every second link rotates by the same angle. These synchronizing elements may be either gears, cables or belts, thus the relative angle between the every second link in the ring linkage (as defined by lines passing through their respective end pivots) remains constant and unchanging even as the position of the linkage is changed.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to Japanese Patent Application No. 2012-023272, filed Feb. 6, 2012, the content of which is hereby incorporated herein by reference in its entirety.
BACKGROUND
The present disclosure relates to an apparatus that can generate data that may be used for forming a cut in a work cloth along a line that indicates a shape of a designated pattern, and to a non-transitory computer-readable medium.
A sewing machine is known in which a cutting blade, instead of a sewing needle, can be mounted on the lower end of a needle bar. The cutting blade is provided with a sharp cutting edge at its tip. The sewing machine may cause the cutting blade to move up and down by moving the needle bar up and down in the same manner as when performing sewing. By repeatedly inserting the cutting blade into a work cloth, the sewing machine may form a cut in the work cloth along a line that indicates a shape of a pattern.
A sewing machine is also known in which two cutting blades can be mounted on the lower ends of separate needle bars in a state in which the directions of the cutting edges at the tips are orthogonal to one another. One of the cutting blades may be attached to the needle bar in a state in which the direction of the cutting edge is orthogonal to a direction in which warp threads of the work cloth extend. The other one of the cutting blades may be attached to the needle bar in a state in which the direction of the cutting edge is orthogonal to a direction in which weft threads of the work cloth extend. The sewing machine may move the work cloth in specified directions, and move the cutting blades up and down by driving respective needle bars. The sewing machine may form a cut in the work cloth by sequentially cutting the warp and the weft threads.
SUMMARY
The length of the cut that is formed in the work cloth by the sewing machines described above is equal to the width of the cutting edge of the cutting blade. Therefore, in a case where a cutting blade with a large cutting edge width is used, the length of the cut that is formed in the work cloth is large. Accordingly, in a case where the sewing machine forms a straight-line cut in the work cloth by using a cutting blade with a large cutting edge width, it becomes possible to reduce the number of times that the cutting blade moves up and down. In other words, the time that is required in order to form the cut can be decreased. However, in a case where the sewing machine forms a curved-line cut in the work cloth by using a cutting blade with a large cutting edge width, a precise cut may not be formed along the curved line, depending on the degree of curvature of the curved line. In contrast, in a case where the sewing machine uses a cutting blade with a small cutting edge width, it is possible to form a precise cut along the curved line. However, in a case where the cutting width is small, the number of times that the cutting blade moves up and down becomes greater. Therefore, the time that is required in order to form the cut in the work cloth along the line that indicates the shape of the pattern may increase.
Various embodiments of the broad principles derived herein provide an apparatus that may generate cut data for cutting a curved line precisely, as well as for cutting a straight-line portion in a short time, and also provide a non-transitory computer-readable medium that stores computer-readable instructions that cause an apparatus to generate the cut data.
Various embodiments provide an apparatus that includes a processor and a memory. The memory is configured to store a plurality of cut length data items and computer-readable instructions. The plurality of cut length data items indicate lengths of a plurality of cuts configured to be formed by a plurality of cutting blades. Each of the plurality of cutting blades is configured to be attachable to one of a plurality of needle bars of a sewing machine. The computer-readable instructions instruct the apparatus to execute steps including acquiring pattern data, wherein the pattern data represent a position of a point on a pattern line and the pattern line indicates a shape of a pattern to be cut along the pattern line, setting, as a plurality of first needle drop points, a plurality of points on the pattern line at predetermined intervals, wherein each of the plurality of first needle drop points is a position at which one of the plurality of cutting blades is to be inserted, setting a cut angle corresponding to each of the plurality of first needle drop points, wherein the cut angle is an angle that is determined based on a direction in which the pattern line extends at a position of each of the plurality of first needle drop points, determining a plurality of second needle drop points among the plurality of first needle drop points, wherein the second needle drop points are arranged consecutively along the pattern line, and the cut angles of the plurality of the second needle drop points are same, consolidating, based on the plurality of cut length data items, at least some of a plurality of second needle drop points into at least one third needle drop point, identifying a cutting blade corresponding to each of a plurality of fourth needle drop points among the plurality of cutting blades based on the plurality of cut length data items, wherein the plurality of fourth needle drop points include at least one first needle drop point which is unconsolidated among the plurality of first needle drop points and at least one third needle drop point which is consolidated, and generating cut data for the sewing machine, wherein the cut data are configured to cause the sewing machine to sequentially insert the identified cutting blades at the plurality of fourth needle drop points along the pattern line.
Embodiments also provide a non-transitory computer-readable medium storing computer-readable instructions. The computer-readable instructions instruct an apparatus to execute steps including acquiring pattern data, wherein the pattern data represent a position of a point on a pattern line and the pattern line indicates a shape of a pattern to be cut along the pattern line, setting, as a plurality of first needle drop points, a plurality of points on the pattern line at predetermined intervals, wherein each of the plurality of first needle drop points is a position at which one of a plurality of cutting blades is to be inserted, setting a cut angle corresponding to each of the plurality of first needle drop points, wherein the cut angle is an angle that is determined based on a direction in which the pattern line extends at a position of each of the plurality of first needle drop points, determining a plurality of second needle drop points among the plurality of first needle drop points, wherein the second needle drop points are arranged consecutively along the pattern line, and the cut angles of the plurality of the second needle drop points are same, consolidating, based on a plurality of cut length data items, at least some of a plurality of second needle drop points into at least one third needle drop point, wherein the plurality of cut length data items indicate lengths of a plurality of cuts configured to be formed by the plurality of cutting blades, identifying a cutting blade corresponding to each of a plurality of fourth needle drop points among the plurality of cutting blades based on the plurality of cut length data items, wherein the plurality of fourth needle drop points include at least one first needle drop point which is unconsolidated among the plurality of first needle drop points and at least one third needle drop point which is consolidated, and generating cut data for the sewing machine, wherein the cut data are configured to cause the sewing machine to sequentially insert the identified cutting blades at the plurality of fourth needle drop points along the pattern line.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments will be described below in detail with reference to the accompanying drawings in which:
FIG. 1 is a perspective view of a sewing machine;
FIG. 2 is a partial front view of a lower end portion of a needle bar case;
FIG. 3 is a plan view of a movement mechanism on which an embroidery frame is mounted;
FIG. 4 is an explanatory figure of a cutting blade data table;
FIG. 5 is a block diagram showing an electrical configuration of the sewing machine;
FIG. 6 is a flowchart of first main processing;
FIG. 7 is an explanatory figure of a pattern;
FIG. 8 is an explanatory figure of a cutting blade data table in which cut lengths are listed;
FIG. 9 is an explanatory figure of needle drop points on a pattern line;
FIG. 10 is an explanatory figure of a cut data table;
FIG. 11 is an explanatory figure of a method for specifying a cut angle;
FIG. 12 is an explanatory figure of a cut data table in which cut angles have been registered;
FIG. 13 is an explanatory figure of a cut data table in which some of needle drop points have been consolidated;
FIG. 14 is an explanatory figure of the needle drop points on the pattern line after some of the needle drop points have been consolidated;
FIG. 15 is an explanatory figure of a cut data table in which needle bars have been registered;
FIG. 16 is an explanatory figure of a rearranged cut data table;
FIG. 17 is an exploded oblique view of a rotatable embroidery frame according to a second embodiment;
FIG. 18 is a plan view that shows the rotatable embroidery frame being held in the movement mechanism;
FIG. 19 is an explanatory figure of a cutting blade data table according to the second embodiment;
FIG. 20 is a flowchart of second main processing;
FIG. 21 is a figure in which cut lengths have been registered in the cutting blade data table that is shown in FIG. 19 ;
FIG. 22 is an explanatory figure of a cut data table according to the second embodiment;
FIG. 23 is an explanatory figure of a cut data table in which the cut angles have been registered;
FIG. 24 is an explanatory figure of a cut data table in a state in which the needle drop point coordinates have been corrected;
FIG. 25 is an explanatory figure of a cut data table in which some of the needle drop points have been consolidated;
FIG. 26 is an explanatory figure of the needle drop points on the pattern line after some of the needle drop points have been consolidated; and
FIG. 27 is an explanatory figure of a cut data table in which data that indicate the needle bars have been registered.
DETAILED DESCRIPTION
Hereinafter, an embodiment will be explained with reference to the drawings. A configuration of a multi-needle sewing machine (hereinafter simply referred to as the sewing machine) 1 according to the present embodiment will be explained with reference to FIGS. 1 to 3 . The upper side, the lower side, the lower left side, the upper right side, the upper left side, and the lower right side in FIG. 1 respectively correspond to the upper side, the lower side, the front side, the rear side, the left side, and the right side of the sewing machine 1 .
As shown in FIG. 1 , a body 20 of the sewing machine 1 includes a support portion 2 , a pillar 3 , and an arm 4 . The support portion 2 is a base portion that is formed in an inverted U shape in a plan view. A left-right pair of guide slots 25 that extend in the front-rear direction are provided in the top face of the support portion 2 . The pillar 3 extends upward from the rear end portion of the support portion 2 . The arm 4 extends toward the front from the upper end portion of the pillar 3 . A needle bar case 21 is attached to the front end of the arm 4 such that the needle bar case 21 can move in the left-right direction. Ten needle bars 7 (needle bars 71 to 80 ; refer to FIG. 2 ) that extend in the up-down direction are disposed at equal intervals in the left-right direction inside the needle bar case 21 . One of the needle bars 7 that is in a sewing position may be moved in the up-down direction by a needle bar drive mechanism 32 (refer to FIG. 5 ) that is provided inside the needle bar case 21 . One of a sewing needle 51 and a cutting blade 52 (refer to FIG. 2 ) can be attached to the lower end of each of the needle bars 7 . That is, the needle bars 7 are configured to receive the cutting blades 52 .
In the example that is shown in FIG. 2 , the sewing needles 51 (a sewing needle 511 and a sewing needle 512 ) are attached to the two of the ten needle bars 7 that are farthest to the left (the needle bar 79 and the needle bar 80 ). The sewing machine 1 may move the sewing needle 51 reciprocally up and down repeatedly by moving the needle bar 7 to which the sewing needle 51 is attached up and down. The sewing machine 1 can thus perform sewing on a work cloth 100 (refer to FIG. 3 ).
The cutting blades 52 (cutting blades 521 to 528 ) can be attached to the eight of the ten needle bars 7 that are on the right side (the needle bars 71 to 78 ). Each of the cutting blades 52 has a cutting edge to form a cut in the work cloth 100 on its lower end. A shaft portion of the upper portion of the cutting blade 52 (refer to FIG. 2 ) has a partially circular cylindrical shape with a flat surface on one side. A positional relationship between the direction of the cutting edge and the flat surface that is formed on the shaft portion is different for each of the cutting blades 521 to 528 . The cutting blade 52 can be attached to the needle bar 7 in a state in which the flat surface on the shaft portion faces toward the rear of the sewing machine 1 . Therefore, the plurality of cutting blades 52 can be attached to the sewing machine 1 in a state in which directions of the cutting edges are different from each other. Note that, the direction of the cutting edge is the direction of the cutting edge when the cutting blade 52 forms a cut in the work cloth 100 . In other words, the direction of the cutting edge is the direction of the cut to be formed in the work cloth 100 . As will be described later, the direction in which the cut that is formed in the work cloth 100 extends, and the length of the cut, is set for each of the cutting blades 521 to 528 . The sewing machine 1 may move the cutting blade 52 reciprocally up and down repeatedly by moving the needle bar 7 to which the cutting blade 52 is attached up and down. The sewing machine 1 can thus form the cuts in the work cloth 100 . As described later, the sewing machine 1 may sequentially form the cuts in the work cloth 100 while switching the cutting blades 521 to 528 .
As shown in FIG. 1 , an operation portion 6 is provided to the right of the central portion of the arm 4 in the front-rear direction. The operation portion 6 includes a liquid crystal display 15 , a touch panel 8 , and a start/stop switch 41 . For example an image including various types of items, such as commands, illustrations, a setting value, a message, and the like may be displayed on the liquid crystal display 15 based on image data. The touch panel 8 is provided on the front face of the liquid crystal display 15 . A user can perform a pressing operation on the touch panel 8 , using a finger or a touch pen. Hereinafter, this operation will be referred to as a panel operation. The touch panel 8 may detect a position pressed by the finger or the touch pen, and the sewing machine 1 (more specifically, a CPU 61 to be described later) may recognize the item that corresponds to the detected position. Thus the sewing machine 1 may recognize the selected item. The user can select a pattern of cuts to be formed in the work cloth 100 , a cutting condition, a command to be executed, or the like, by performing a panel operation. The start/stop switch 41 is a switch for inputting commands that cause the sewing machine 1 to start and stop the sewing and the forming of the cuts.
A cylindrical cylinder bed 10 that extends toward the front from the lower end portion of the pillar 3 is provided below the arm 4 . A shuttle (not shown in the drawings) is provided inside the front end portion of the cylinder bed 10 . The shuttle can house a bobbin (not shown in the drawings), on which a bobbin thread (not shown in the drawings) is wound. A shuttle drive mechanism (not shown in the drawings) is provided inside the cylinder bed 10 . The shuttle drive mechanism (not shown in the drawings) may rotationally drive the shuttle. A needle plate, having a rectangular shape in a plan view, is provided in the upper face of the cylinder bed 10 . The needle plate 16 is provided with a needle hole 36 , through which the sewing needle 51 can pass.
A left-right pair of thread spool holders 12 are provided on the rear portion of an upper face of the arm 4 . Ten thread spools 13 , the same number as the number of the needle bars 7 , can be mounted on the pair of the thread spool holders 12 . Needle thread 38 may be supplied from the thread spools 13 mounted on the thread spool holders 12 . The needle thread 38 may be supplied via a thread guide 17 , a tensioner 18 , a thread take-up lever 39 , and the like to an eye (not shown in the drawings) of one of the sewing needles 51 that is attached to the lower end of the needle bars 7 .
A Y carriage 23 of a movement mechanism 11 (refer to FIGS. 3 and 5 ) is provided below the arm 4 . Various types of embroidery frames 84 (refer to FIG. 3 ) can be mounted on the movement mechanism 11 . That is, the sewing machine 1 is configured to receive the embroidery frame 84 . The embroidery frame 84 is configured to hold the work cloth 100 . The movement mechanism 11 may cause the embroidery frame 84 to move in the front-rear and left-right directions using an X axis motor 132 (refer to FIG. 5 ) and a Y axis motor 134 (refer to FIG. 5 ) as drive sources.
The embroidery frame 84 and the movement mechanism 11 will be explained with reference to FIG. 3 . The embroidery frame 84 includes an outer frame 81 , an inner frame 82 , and a left-right pair of coupling portions 89 . The outer frame 81 and the inner frame 82 of the embroidery frame 84 may clamp the work cloth 100 . Each of the coupling portions 89 is a plate-shaped member having a rectangular shape in a plan view and having a rectangular cut-out in the central portion. One of the coupling portions 89 is fixed to the right portion of the inner frame 82 by screws 86 . The other of the coupling portions 89 is fixed to the left portion of the inner frame 82 by screws 85 .
The movement mechanism 11 includes a holder 24 , an X carriage 22 , an X axis drive mechanism (not shown in the drawings), the Y carriage 23 , and a Y axis drive mechanism (not shown in the drawings). The holder 24 is configured to detachably support the embroidery frame 84 . The holder 24 includes a mounting portion 90 , a right arm portion 97 , and a left arm portion 98 . The mounting portion 90 is a plate member having a rectangular shape in a plan view, and is longer in the left-right direction. The right arm portion 97 extends in the front-rear direction, and a rear end portion of the right arm portion 97 is fixed to the right end of the mounting portion 90 . The left arm portion 98 extends in the front-rear direction. The rear end portion of the left arm portion 98 is fixed to a left portion of the mounting portion 90 such that the position in the left-right direction with respect to the mounting portion 90 can be adjusted. The right arm portion 97 may be engaged with one of the coupling portions 89 , and the left arm portion 98 may be engaged with the other of the coupling portions 89 .
The X carriage 22 is a plate member, and is longer in the left-right direction. A part of the X carriage 22 projects forward from the front face of the Y carriage 23 . The mounting portion 90 of the holder 24 may be attached to the X carriage 22 . The X axis drive mechanism (not shown in the drawings) includes a linear movement mechanism (not shown in the drawings). The linear movement mechanism includes a timing pulley (not shown in the drawings) and a timing belt (not shown in the drawings), and the linear movement mechanism may cause the X carriage 22 to move in the left-right direction (the X axis direction) using the X axis motor 132 as a drive source.
The Y carriage 23 is a box-shaped member that is longer in the left-right direction. The Y carriage 23 supports the X carriage 22 such that the X carriage 22 can move in the left-right direction. The Y axis drive mechanism (not shown in the drawings) includes a pair of left and right movable members (not shown in the drawings) and a linear movement mechanism (not shown in the drawings). The movable members are connected to the lower portions of the left and right ends of the Y carriage 23 and vertically pass through the guide slots 25 (refer to FIG. 1 ). The linear movement mechanism includes a timing pulley (not shown in the drawings) and a timing belt (not shown in the drawings). The linear movement mechanism may cause the movable members to move in the front-rear direction (the Y axis direction) along the guide slots 25 using the Y axis motor 134 as a drive source. The Y carriage 23 that is connected to the movable members, and the X carriage 22 that is supported by the Y carriage 23 may move in the front-rear direction (the Y axis direction) in accordance with the movement of the movable members. In a state in which the embroidery frame 84 that holds the work cloth 100 is attached to the X carriage 22 , the work cloth 100 is disposed between the needle bars 7 and the needle plate 16 (refer to FIG. 1 ).
The directions and the lengths of the cuts that may be formed in the work cloth 100 by the cutting blades 521 to 528 that are attached to the needle bars 71 to 78 will be explained with reference to a cutting blade data table 46 shown in FIG. 4 . A cut direction is a direction in which a cut extends. A cut length is a length of a cut. The cutting blade data table 46 is stored in an EEPROM 64 (refer to FIG. 5 ). The cut directions and the cut lengths that correspond to the cutting blades 521 to 528 that are respectively attached to the needle bars 71 to 78 are listed in the cutting blade data table 46 shown in FIG. 4 . The cut directions and the cut lengths that are listed in the cutting blade data table 46 are data input by panel operations by the user.
The cut directions respectively correspond to the directions in which the cutting edges of the cutting blades 52 that are attached to the needle bars 7 extend. The cut lengths are the same as the cutting edge widths of the cutting blades 52 . For example, the cutting edge of the cutting blade 521 attached to the needle bar 71 extends in the left-right direction of the sewing machine 1 (refer to FIG. 2 ). Therefore, the direction of the cut that is formed in the work cloth 100 by the cutting blade 521 is in the left-right direction. In the present embodiment, the left-right direction of the sewing machine 1 corresponds to a cut direction of zero degrees. A direction from the left front toward the right rear corresponds to a cut direction of 45 degrees. The front-rear direction corresponds to a cut direction of 90 degrees. A direction from the right front toward the left rear corresponds to a cut direction of 135 degrees. The cut direction of zero degrees is listed in the cutting blade data table 46 in association with the cutting blade 521 . A cut length of 1.5 millimeters is also listed in association with the cutting blade 521 .
The cut length for each of the cutting blades 521 to 524 is 1.5 millimeters. The cut length for each of the cutting blades 525 to 528 is 3 millimeters, which is twice of 1.5 millimeters. The cut directions for the cutting blade 521 and the cutting blade 525 are the same at zero degrees. The cut directions for the cutting blade 522 and the cutting blade 526 are the same at 45 degrees. The cut directions for the cutting blade 523 and the cutting blade 527 are the same at 90 degrees. The cut directions for the cutting blade 524 and the cutting blade 528 are the same at 135 degrees. That is, the cutting blades 525 to 528 have respectively the same cut directions as the cutting blades 521 to 524 and have cut lengths that are twice as long.
An electrical configuration of the sewing machine 1 will be explained with reference to FIG. 5 . As shown in FIG. 5 , the sewing machine 1 includes a sewing needle drive portion 120 , a sewn object drive portion 130 , the operation portion 6 , and a control portion 60 . The sewing needle drive portion 120 includes a drive circuit 121 , a drive shaft motor 122 , a drive circuit 123 , and a needle bar case motor 45 . The drive circuit 121 may drive the drive shaft motor 122 in accordance with a control signal from the control portion 60 . The drive shaft motor 122 may drive the needle bar drive mechanism 32 by rotationally driving a drive shaft (not shown in the drawings), and cause the needle bar 7 to reciprocate up and down. The drive circuit 123 may drive the needle bar case motor 45 in accordance with a control signal from the control portion 60 . The needle bar case motor 45 may drive a movement mechanism that is not shown in the drawings and thereby cause the needle bar case 21 to move in the left-right direction.
The sewn object drive portion 130 includes a drive circuit 131 , the X axis motor 132 , a drive circuit 133 , and the Y axis motor 134 . The drive circuit 131 may drive the X axis motor 132 in accordance with a control signal from the control portion 60 . The X axis motor 132 may drive the movement mechanism 11 and thereby cause the embroidery frame 84 (refer to FIG. 3 ) to move in the left-right direction by driving the movement mechanism 11 . The drive circuit 133 may drive the Y axis motor 134 in accordance with a control signal from the control portion 60 . The Y axis motor 134 may drive the movement mechanism 11 and thereby cause the embroidery frame 84 to move in the front-rear direction.
The operation portion 6 includes the touch panel 8 , a drive circuit 135 , the liquid crystal display 15 , and the start/stop switch 41 . The drive circuit 135 may drive the liquid crystal display 15 in accordance with a control signal from the control portion 60 .
The control portion 60 includes the CPU 61 , a ROM 62 , a RAM 63 , the EEPROM 64 , and an input/output interface (I/O) 66 , which are mutually connected by a signal line 65 . The sewing needle drive portion 120 , the sewn object drive portion 130 , and the operation portion 6 are each connected to the I/O 66 .
The CPU 61 is configured to perform main control of the sewing machine 1 . The CPU 61 may perform various operations and processing that relate to sewing, in accordance with various programs stored in a program storage area (not shown in the drawings) of the ROM 62 . Although these are not shown in the drawings, the ROM 62 includes a plurality of storage areas that include the program storage area. Various programs for operating the sewing machine 1 , including a main program, may be stored in the program storage area. The main program is a program for performing first main processing that will be described later. The RAM 63 includes, as necessary, storage areas to store data such as operation results and the like processed by the CPU 61 . In addition to the cutting blade data table 46 (refer to FIG. 4 ), various parameters for the sewing machine 1 to perform various processing may be stored in the EEPROM 64 .
The first main processing will be explained with reference to FIG. 6 . In the first main processing, cut data (for example, data that are stored in a cut data table 47 that is shown in FIG. 16 ) are generated. The cut data are control data that is necessary to cause the sewing machine 1 to perform operations to form cuts in the work cloth 100 along a line that indicates a shape of a pattern. A line that indicates a shape of a pattern will be hereinafter referred to as a pattern line. The sewing machine 1 may form the cuts in the work cloth 100 along the pattern line based on the generated cut data.
The first main processing that is shown in FIG. 6 is performed in a case where the user inputs a command to start the first main processing. The command to start the first main processing may be input by a panel operation, for example. The program for performing the first main processing is stored in the ROM 62 (refer to FIG. 5 ) and is performed by the CPU 61 .
As shown in FIG. 6 , first, the CPU 61 determines whether pattern data have been acquired (Step S 11 ). The pattern data are data for a pattern line along which cuts are to be formed. For example, the pattern data are data that represent a position of a given point on the pattern line with respect to the work cloth 100 , in a case where cuts are formed along the pattern line on the work cloth 100 . The pattern data may be vector data, for example. The user may input a shape of the pattern line by a panel operation. The CPU 61 may then acquire the data indicating the input pattern line as the pattern data. In a case where the pattern data have not been acquired (NO at Step S 11 ), the CPU 61 repeats the processing at Step S 11 .
In a case where a pattern line 101 for a ring-like pattern 102 , as shown in FIG. 7 , has been input, the CPU 61 acquires the pattern data indicating the pattern line 101 . In a case where the pattern data for the pattern line 101 have been acquired (YES at Step S 11 ), the CPU 61 stores the acquired pattern data in the RAM 63 (Step S 12 ).
The CPU 61 may also acquire the pattern data by another method. For example, the user may input a plurality of points as the pattern line by a panel operation. The CPU 61 may acquire data representing line segments that connect the plurality of input points as the pattern data. The sewing machine 1 may be provided with a card slot not shown in the drawings, for example. The user may insert into the card slot a memory card in which the pattern data are stored. The CPU 61 may acquire the pattern data by reading out the pattern data stored in the memory card inserted into the card slot.
Next, the CPU 61 identifies a minimum cut length by referring to the cutting blade data table 46 (refer to FIG. 4 ) (Step S 13 ). The minimum cut length is the shortest cut length among the cut lengths for the cutting blades 52 (the cutting blades 521 to 528 ) that are attached to the needle bars 7 . The CPU 61 identifies the minimum cut length as L that was identified at Step S 13 and stores the minimum cut length L in the cutting blade data table 46 (Step S 14 ). For the cutting blades 52 that are associated with cut lengths other than the minimum cut length, the CPU 61 computes multiples of the minimum cut length L. Based on the computed multiples, the CPU 61 stores the cut lengths that respectively correspond to the cutting blades 52 in the cutting blade data table 46 (Step S 15 ).
For example, in the case of the cutting blade data table 46 that is shown in FIG. 4 , the needle bars 71 to 74 are each associated with the minimum cut length of 1.5 millimeters. Therefore, the CPU 61 identifies 1.5 millimeters as the minimum cut length (Step S 13 ) and identifies 1.5 millimeters as L (Step S 14 ). For the needle bars 75 to 78 , with which cut lengths other than the minimum cut length are associated, the CPU 61 computes multiples of the minimum cut length L. The CPU 61 registers the computation results in the cutting blade data table 46 (Step S 15 ). In this manner, the minimum cut length L is associated with each of the needle bars 71 to 74 , and the cut length 2L is associated with each of the needle bars 75 to 78 as shown in FIG. 8 .
The CPU 61 sets needle drop points consecutively at predetermined intervals along the pattern line 101 that is indicated by the pattern data stored in the RAM 63 (Step S 16 ). In the present embodiment, the predetermined interval is equal to the minimum cut length L. The positions (the coordinates) of the set needle drop points are stored in the cut data table 47 (refer to FIG. 10 and the like) stored in the RAM 63 . For example, in a case where the pattern line 101 shown in FIG. 7 has been input, the CPU 61 sets the needle drop points such that the needle drop points are arranged at the predetermined intervals along the pattern line 101 . In this case, needle drop points QX (X=1, 2, . . . 73) are set consecutively along the pattern line 101 as shown in FIG. 9 . Note that QX is the number of the needle drop point. The numerical values for X are assigned consecutively to the set needle drop points along the pattern line 101 , such that the numerical value of a particular needle drop point on the pattern line 101 is taken as 1 (the point at the lower left in the example in FIG. 9 ). Then the data for the (X, Y) coordinates for the set needle drop points Q 1 to Q 73 are registered in the cut data table 47 , as shown in FIG. 10 . Note that, hereinafter, the coordinate data for the needle drop points QX are sometimes simply referred to as the needle drop points QX. At this time, cutting sequence numbers from 1 to 73 are also assigned consecutively to the needle drop points Q 1 to Q 73 .
The CPU 61 sets a cut angle for each of the needle drop points QX that was set by the processing at Step S 16 (Step S 17 ). The cut angle is an angle of a cut along the pattern line. More specifically, the cut angle is an angle that is set based on the direction in which the pattern line extends at each of the needle drop points. For example, in the processing at Step S 17 , among the cut directions that are stored in the cutting blade data table 46 for the plurality of cutting blades 521 to 528 , the cut direction that is the closest to the direction in which the pattern line 101 extends at the needle drop point QX is set as the cut angle. The setting process will hereinafter be described in detail.
The method for setting the cut angle will be explained in detail with reference to FIG. 11 . First, as shown in FIG. 11 , line segments 111 , 112 , 113 that respectively connect two adjacent needle drop points QX (Q 4 to Q 5 , Q 5 to Q 6 , and Q 6 to Q 7 ) are defined. Then, with the needle drop point Q 4 serving as a reference point, the positive direction of the X axis indicating zero degrees and the positive direction of the Y axis indicating 90 degrees, the CPU 61 identifies the angle that is formed between the line segment 111 and the X axis as the direction in which the line segment 111 extends. The CPU 61 identifies the directions in which the line segments 112 , 113 extend in the same manner. Among the cut directions of zero degrees, 45 degrees, 90 degrees, and 135 degrees that are registered in the cutting blade data table 46 (refer to FIG. 8 ), the cut direction that is the closest to the direction in which the line segment 111 extends is set as the cut angle of the line segment 111 . The CPU 61 sets the cut angles of the line segments 112 and 113 in the same manner. For example, the CPU 61 subtracts each of the cut directions that have been registered in the cutting blade data table 46 from the direction in which the line segment 111 extends. The CPU 61 then identifies, as the cut direction that is the closest to the line segment 111 , the cut direction for which the result of the subtraction is closest to zero. For example, in a case where it is determined that the direction in which the line segment 111 extends is closest to the cut direction of 90 degrees, the cut angle for each of the needle drop points Q 4 and Q 5 positioned at both ends of the line segment 111 is set to 90 degrees. In the same manner, in a case where it is determined that the direction in which the line segment 112 extends is closest to the cut direction of 90 degrees, the cut angle for each of the needle drop points Q 5 and Q 6 positioned at both ends of the line segment 112 is set to 90 degrees. In a case where it is determined that the direction in which the line segment 113 extends is closest to the cut direction of 45 degrees, the cut angle for each of the needle drop points Q 6 and Q 7 positioned at both ends of the line segment 113 is set to 45 degrees.
In a case where the cut angles are set for all of the needle drop points QX, the data for the cut angles are registered in the cut data table 47 shown in FIG. 10 , and the cut angle column of the cut data table 47 is filled, as shown in FIG. 12 . The directions in which the line segment 111 and the line segment 112 extend are both closest to the cut direction of 90 degrees (refer to FIG. 11 ). Therefore, the CPU 61 sets the cut angle for the needle drop point Q 5 , which is at one end of each of the line segments 111 and 112 , to 90 degrees, as shown in FIG. 12 . The direction in which the line segment 112 extends is closest to 90 degrees, and the direction in which the line segment 113 extends is closest to 45 degrees (refer to FIG. 11 ). Therefore, for the cut angle of the needle drop point Q 6 , which is at one end of each of the line segments 112 and 113 , the CPU 61 sets the two cut angles to 90 degrees and 45 degrees. Note that in a case where two cut angles such as 90 degrees and 45 degrees are set for a single needle drop point QX, each of the two cutting blades 52 that have the corresponding cut directions forms one cut at the single needle drop point QX. Furthermore, for the needle drop point Q 1 , which is the first needle drop point, the cut angles are set based on the directions in which the line segment from Q 1 to Q 2 and the line segment from Q 73 (the final needle drop point) to Q 1 respectively extend. For the needle drop point Q 73 , which is the final needle drop point, the cut angles are set based on the directions in which the line segment from Q 72 to Q 73 and the line segment from Q 73 to Q 1 respectively extend.
Next, the CPU 61 sets a variable N to zero (Step S 18 ). The variable N is a variable that indicates the cutting sequence number in the cut data table 47 (refer to FIG. 12 ). The CPU 61 sets a variable P to 1 (Step S 19 ). The variable P is a variable that the CPU 61 uses to count the number of the consecutive needle drop points QX for which the cut angles are the same. The CPU 61 increments the variable N by increasing the value of the variable N by 1 (Step S 20 ). By referring to the cut data table 47 , the CPU 61 determines whether data exist for the cutting sequence number that corresponds to the variable N (Step S 21 ). Note that a case in which the data do not exist for the cutting sequence number that corresponds to the variable N is a case in which the processing at Steps S 22 to S 27 , which is described later, has been performed for all of the needle drop points QX.
In a case where the data exist for the cutting sequence number that corresponds to the variable N (YES at Step S 21 ), the CPU 61 refers to the cut data table 47 and acquires the cut angle for the needle drop point QX with the cutting sequence number that corresponds to the variable N (Step S 22 ). The CPU 61 determines whether the cut angle for the needle drop point QX that was acquired by the processing at Step S 22 is the same as the cut angle for the needle drop point QX that corresponds to the variable N minus 1 (Step S 23 ). In other words, the CPU 61 determines whether the cut angles for the consecutive needle drop points QX are the same. In a case where the cut angles are the same (YES at Step S 23 ), the CPU 61 increments the variable P by increasing the value of the variable P by 1 (Step S 24 ). In this manner, the number of the consecutive needle drop points QX for which the cut angles are the same is counted. The CPU 61 returns the processing to the processing at Step S 20 .
In a case where the CPU 61 has determined that the cut angles are not the same (NO at Step S 23 ), the CPU 61 determines whether the variable P is 2 or more (Step S 25 ). In other words, the CPU 61 determines whether consecutive needle drop points QX exist for which the cut angles are the same. In a case where the successive cut angles are not the same and the variable P is 1 (NO at Step S 25 ), the CPU 61 advances the processing to the processing at Step S 27 , which will be described later.
In a case where the variable P is 2 or more (YES at Step S 25 ), the CPU 61 , based on the cut lengths that are stored in the cutting blade data table 46 , consolidates at least a part of the at least two consecutive needle drop points QX for which the cut angles are the same into a single needle drop point (Step S 26 ). In the explanation that follows, the needle drop point into which the other needle drop points have been consolidated by the processing at Step S 26 is referred to as the needle drop point QX′. Specifically, first, the cut angles for the consecutive needle drop points QX for which the cut angles are the same are identified. For example, in the cut data table 47 (refer to FIG. 12 ), the cut angle 45 degrees is associated with each of the needle drop points Q 17 to Q 28 . Therefore, 45 degrees is identified as the consecutively identical cut angle. Next, the cutting blade data table 46 is referenced, and from among the cut lengths that are associated with the specified cut angle of 45 degrees, the cut length 2L is identified as the cut length for which the multiple is closest to the variable P while not exceeding the value of the variable P. The needle drop points Q 17 to Q 28 are set consecutively at intervals of the minimum cut length L. The CPU 61 consolidates two of the consecutive needle drop points QX that are each associated with the cut length L into the single needle drop point QX′, which is associated with the cut length 2L. The CPU 61 computes an intermediate point between the two needle drop points QX and then consolidates the two needle drop points QX into the single needle drop point QX′ at the computed intermediate point. For example, coordinates for Q 17 are (X 17 , Y 17 ), and coordinates for Q 18 are (X 18 , Y 18 ). Accordingly, the X coordinate for the intermediate point is {(X 17 +X 18 )/2}, and the Y coordinate for the intermediate point is {(Y 17 +Y 18 )/2}. Thus the two needle drop points Q 17 , Q 18 that are shown in FIG. 12 are consolidated into a needle drop point Q 17 ′((X 17 +X 18 )/2, (Y 17 +Y 18 )/2), as shown in FIG. 13 . Note that the cutting sequence numbers are changed in the order of the X values of the needle drop points QX and QX′. Some of the other needle drop points QX may also be consolidated in the same manner.
FIG. 14 is a figure that shows the needle drop points QX′ that have been consolidated by the processing at Step S 26 , and the unconsolidated needle drop points QX, on the pattern line 101 . In the present embodiment, the sets of two consecutive needle drop points QX for which the cut angles are the same are each consolidated into the needle drop points QX′. Therefore, as shown in FIG. 14 , the total number of the needle drop points QX and the needle drop points QX′ is less than the number of the needle drop points before the processing at Step S 26 was performed (refer to FIG. 9 ).
Next, based on the cut lengths and the cut directions stored in the cutting blade data table 46 , the CPU 61 sets for each of the needle drop points QX′, the needle drop points QX′ and QX, or the needle drop points QX, as the case may be, from among the plurality of needle bars 71 to 78 , one of the needle bars 7 to which one of the cutting blades 52 is attached. That is, the CPU 61 identifies for each of the needle drop points QX′, the needle drop points QX′ and QX, or the needle drop points QX, as the case may be, from among the plurality of needle bars 71 to 78 , one of the needle bars 7 to which one of the cutting blades 52 is attached. The CPU 61 registers the data that indicate the needle bars 7 that have been set in the cut data table 47 in association with the corresponding needle drop points QX and needle drop points QX′ (Step S 27 ). For example, the needle drop point Q 7 has not been consolidated by the processing at Step S 26 (the position (coordinates) has not been changed). The cut angle 45 degrees has been associated with the needle drop point Q 7 by the processing at Step S 17 . The needle drop point Q 7 is also a needle drop point for which the intervals between the needle drop point Q 7 and the adjacent needle drop points Q 6 and Q 8 have both been set to the same interval, the cut length L. Accordingly, the CPU 61 refers to the cutting blade data table 46 (refer to FIG. 8 ) and sets the needle bar 72 , to which the cutting blade 522 , which is associated with the cut angle 45 degrees and the cut length L, has been attached. Then the data that indicate the needle bar 72 are registered in the cut data table 47 in association with the needle drop point Q 7 , as shown in FIG. 15 . The needle drop point Q 17 and the needle drop point Q 18 have been consolidated into the needle drop point Q 17 ′ by the processing at Step S 26 (the position (coordinates) has been changed). The cut angle 45 degrees is associated with the needle drop point Q 17 ′. The needle drop point Q 17 ′ is the needle drop point QX′, generated by consolidating the two needle drop points Q 17 and Q 18 , for which the intervals are set to the cut length L, into a single needle drop point. Therefore, in a case where the cutting blade 52 is inserted at the needle drop point Q 17 ′, it is necessary for the cut length that is formed to be 2L. Accordingly, the CPU 61 refers to the cutting blade data table 46 (refer to FIG. 8 ) and sets the needle bar 76 , to which the cutting blade 526 , which is associated with the cut angle 45 degrees and the cut length 2L, is attached. Then the data indicating the needle bar 76 are registered in the cut data table 47 in association with the needle drop point Q 17 ′, as shown in FIG. 15 . After the CPU 61 has set one of the needle bars 7 to which one of the cutting blades 52 is attached in the processing at Step S 27 , the CPU 61 returns the processing to the processing at Step S 19 , and sets the variable P to 1.
In a case where the CPU 61 has performed the processing at Steps S 22 to S 27 for all of the needle drop points QX, the CPU 61 determines that the data do not exist for the cutting sequence number that corresponds to the variable N (NO at Step S 21 ). The CPU 61 changes the cutting order for the needle drop points QX and the needle drop points QX′ such that the same cutting blade 52 is to be used consecutively when the sewing machine 1 is operated (Step S 28 ). In the processing at Step S 28 , the data that are registered in the cut data table 47 are rearranged such that all of the data that are associated with the same needle bar 7 (the same cutting blade 52 ) are grouped together consecutively into a single series. For example, in FIG. 15 , the needle bar 76 (the cutting blade 526 ) is associated with the needle drop points Q 17 ′ to Q 27 ′ and the needle drop points Q 47 ′ to Q 53 ′. Accordingly, as shown in FIG. 16 , the cutting order for the needle drop points is rearranged such that the needle drop points Q 17 ′ to Q 27 ′ and the needle drop points Q 47 ′ to Q 53 ′ are grouped together consecutively into a single series. The cutting order is rearranged in the same manner for the other needle bars 71 , 72 , 73 , 74 , 75 , 77 , 78 . Note, for example, the needle bar 71 and the needle bar 73 are associated with the needle drop point Q 1 (refer to FIG. 15 ). In this case, the cutting order is rearranged such that the needle drop point Q 1 is associated separately with both the needle bar 71 and the needle bar 73 . Therefore, as shown in FIG. 16 , for example, the needle drop point Q 1 is associated separately with both the needle bar 71 and the needle bar 73 . The cutting order is arranged for all of the needle drop points QX, QX′ such that the cutting blades 52 that are respectively attached to the needle bars 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 are to be used in this order when the sewing machine 1 is operated. After the cutting order has been rearranged, the cutting sequence numbers are reassigned in order, starting from the beginning. The data that are registered in the cut data table 47 after being rearranged in this manner are referred to as the cut data.
The CPU 61 causes the sewing machine 1 to form the cuts along the pattern line 101 in accordance with the cut data (Step S 29 ). More specifically, the CPU 61 reads in order the data that correspond to the cutting sequence numbers in the cut data table 47 and moves the needle bar case 21 such that the needle bar 7 that is specified for the current cutting sequence number is disposed in the sewing position. By moving the embroidery frame 84 , the CPU 61 also changes the position in which the work cloth 100 is held in relation to the cutting blade 52 , such that the cutting blade 52 is disposed directly above the position that is specified by the coordinates of the needle drop point. The CPU 61 then moves the needle bar 7 , to the lower end of which the cutting blade 52 is attached, up and down. The cutting blade 52 thus moves reciprocally up and down, repeatedly piercing the work cloth 100 to cut the threads of the work cloth 100 along the pattern line 101 . The cut is thus formed in the work cloth 100 along the pattern line 101 . In a case where the CPU 61 has finished forming the cut using the needle bar 7 specified for the last cutting sequence number, the CPU 61 terminates the first main processing.
The CPU 61 performs the processing in the present embodiment as described above. The cut angles that are set at Step S 17 for the consecutive needle drop points QX along a straight-line portion of the pattern line 101 are all the same angle. In this case, at least some of the consecutive needle drop points QX that have the same cut angle are consolidated into the single needle drop point QX′, based on the cut lengths that are stored in the cutting blade data table 46 (Step S 26 ). The needle bar 7 to which is attached the cutting blade 52 that is to be inserted at the consolidated needle drop point QX′ is set from among the plurality of needle bars 71 to 78 and is registered in the cut data table 47 (Step S 27 ). Because some of needle drop points QX are consolidated into the single needle drop point QX′, the number of the needle drop points is reduced. Consequently, when the cuts are formed along the pattern line 101 by the processing at Step S 29 , the number of times that the needle bar 7 moves up and down in order to cut along the straight-line portion of the pattern line 101 is reduced. The sewing machine 1 can cut along the straight-line portion of the pattern line 101 in a shorter time, making it possible to cut the work cloth 100 more efficiently.
The cut angles for the consecutive needle drop points QX along a curved-line portion of the pattern line 101 are not the same angle. Therefore, the processing at Step S 26 is not performed, and none of the needle drop points QX are consolidated into the needle drop point QX′. The interval between two adjacent needle drop points QX that have not been consolidated is a predetermined interval (in the present embodiment, the minimum cut length L). Therefore, the interval between the two adjacent needle drop points QX that have not been consolidated is less than the interval between the consolidated needle drop point QX′ and the adjacent needle drop point QX. Then the needle bar 7 to which the cutting blade 52 is attached that is to be inserted at the needle drop point QX is set based on the cut length (Step S 27 ). In this case, the cutting blade 52 that is attached to the needle bar 7 that has been set is one of the cutting blades 521 to 524 , for which the cut length is L. In other words, the sewing machine 1 can specify, as the cutting blade 52 that is to be inserted at the needle drop point QX, one of the cutting blades 521 to 524 (cut length L), for which the cut length is shorter than the cut length for the cutting blades 525 to 528 (cut length 2L). Therefore, it is possible to form the cuts in the curved-line portion by using the cutting blades 521 to 524 , for which the cut length is shorter than the cut length for the cutting blades 525 to 528 . In this manner, the sewing machine 1 can generate the cut data for forming precise cuts along the curved-line portion of the pattern line 101 , as well as for cutting along the straight-line portion of the pattern line 101 in a shorter time.
Furthermore, in the present embodiment, the predetermined interval that is used in the setting of the needle drop points QX by the processing at Step S 16 is equal to the minimum cut length L. In this case, in a case where the cutting blades 52 to be inserted at the needle drop points QX are set by the processing at Step S 27 based on the cut length, the needle bars 7 to which the cutting blades 521 to 524 are attached can be set, having the minimum cut length L that is the same as the predetermined interval. Accordingly, the sewing machine 1 can form the cuts in the work cloth 100 using the cutting blades 521 to 524 with the cut length L, which is the same as the interval between the two adjacent needle drop points QX and thereby form precise cuts in the work cloth 100 . Note that the predetermined interval may also be other than the minimum cut length L. For example, in a case where a plurality of cutting blades having different cut lengths (for example, L, 2L, 3L) are attached to a plurality of needle bars 7 , respectively, the predetermined interval may be set to the same length as any one of the plurality of different cut lengths. In that case as well, the sewing machine 1 can form the cuts in the work cloth 100 using the cutting blades with the cut length that is the same as the interval between the two adjacent needle drop points QX and thereby form precise cuts in the work cloth 100 along the pattern line 101 .
In the present embodiment, the cut length is the same as the cutting edge width of the cutting blade 52 . Because the cut length and the cutting edge width are the same, the external appearance of the cutting blade 52 matches the cut length. Therefore, for example, in a case where the user registers the cut length in the cutting blade data table 46 , the user can register the cut length based on the external appearance of the cutting blade 52 .
In the present embodiment, the cut lengths of the plurality of cutting blades 52 are set to integer multiples of the minimum cut length L (in the present embodiment, L and 2L). The predetermined interval when the needle drop points QX are set by the processing at Step S 16 is the same as the minimum cut length L. Furthermore, in a case where at least some of the consecutive needle drop points QX for which the cut angles are the same are consolidated into the needle drop points QX′ by the processing at Step S 26 , the interval between two of the consolidated needle drop points QX′ that are adjacent to one another is an integer multiple of the minimum cut length L. In the processing at Step S 27 , for each of the needle drop points QX that were not consolidated by the processing at Step S 26 , one of the needle bars 71 to 74 , to which the cutting blades 521 to 524 that have the minimum cut length L are attached, is set as the needle bar 7 to which is attached the cutting blade 52 that is to be inserted at the needle drop point QX. In addition, one of the needle bars 75 to 78 that have cut lengths of 2L, which is an integer multiple of the minimum cut length L, is set as the needle bar 7 to which is attached the cutting blade 52 that is to be inserted at the consolidated needle drop point QX. The cut lengths of the cutting blades 52 correspond to the intervals between the pairs of adjacent needle drop points. Therefore, in a case where the CPU 61 sets the needle bars 7 in the processing at Step S 27 , the CPU 61 can set the needle bars 7 to which are attached the appropriate cutting blades 52 for inserting at the respective needle drop points QX, QX′.
In the present embodiment, in the processing at Step S 28 , the cutting order for the needle drop points QX and the needle drop points QX′ is changed such that cuts are formed consecutively by the same cutting blade 52 . When the sewing machine 1 switches the cutting blade 52 , stopping the rotation of the drive shaft motor 122 and moving the needle bar case 21 in the left-right direction are necessary. Therefore, in a case where the cutting blade 52 is switched frequently, the sewing machine 1 takes more time to finish forming the cuts along the pattern line 101 in the work cloth 100 than in a case where the same cutting blade 52 is used continuously. In the present embodiment, the cutting order for the needle drop points QX and the needle drop points QX′ is changed such that the same cutting blade 52 is used consecutively. Therefore, when the sewing machine 1 performs the cutting at Step S 29 , the cuts can be formed consecutively by the same cutting blade 52 . Therefore, the number of times that the cutting blade 52 is switched (the needle bar 7 is switched) is less than in a case where the cutting order is not changed. Accordingly, the time that the sewing machine 1 requires in order to form the cuts along the pattern line 101 can be shortened, and the cuts can be formed in the work cloth 100 more efficiently.
Next, a second embodiment will be explained. The second embodiment is an example in which a rotatable embroidery frame 9 is used as the embroidery frame. First, the embroidery frame 9 will be explained with reference to FIGS. 17 and 18 . In the explanation that follows, the up-down direction in the FIG. 17 is defined as the up-down direction of an outer frame 94 . As shown in FIGS. 17 and 18 , the embroidery frame 9 includes an inner frame 91 , a middle frame 92 , and the outer frame 94 , each of which has a circular frame shape. As shown in FIG. 18 , the embroidery frame 9 is formed by disposing the middle frame 92 to the outside of the inner frame 91 in the radial direction and by disposing the outer frame 94 to the outside of the middle frame 92 in the radial direction. The embroidery frame 9 is configured to clamp the work cloth 100 between the inner frame 91 and the middle frame 92 . The middle frame 92 is configured to be rotatable in relation to the outer frame 94 . The inner frame 91 and the middle frame 92 are rotatable in relation to the outer frame 94 around an axis of rotation R shown in FIG. 17 . Note that in the embroidery frame 9 of the present embodiment, the rotation axis R passes through the center of each circle formed by each of the inner frame 91 , the middle frame 92 , and the outer frame 94 (specifically, frame portions 911 , 921 , 941 , which will be described later). Hereinafter, the direction of the rotation axis R is simply referred to as an axial direction.
As shown in FIGS. 17 and 18 , the inner frame 91 includes the circular frame portion 911 . The frame portion 911 has thicknesses in the axial direction and in the radial direction. The inner frame 91 includes an adjustment portion 915 that is configured to adjust the diameter of the inner frame 91 . The diameter of the inner frame can be adjusted according to the thickness of the work cloth 100 that is clamped between the inner frame 91 and the middle frame 92 . The adjustment portion 915 includes a parting portion 916 , a pair of screw mounting portions 917 , and an adjusting screw 918 . The parting portion 916 is a location where a portion in the circumferential direction of the frame portion 911 of the inner frame 91 is discontinuous through the axial direction. The pair of the screw mounting portions 917 are provided on upper portions on both sides of the parting portion 916 in the frame portion 911 . The pair of the screw mounting portions 917 project to the outside in the radial direction and are positioned opposite one another. The pair of the screw mounting portions 917 have holes 9171 , 9172 , respectively, that respectively pass through the screw mounting portions 917 in a direction that is orthogonal to the faces of the screw mounting portions 917 that are opposite each other. Of the two holes 9171 , 9172 , a nut (not shown in the drawings), in which a threaded hole is formed, is embedded in the one hole 9172 (the hole on the lower right side in FIG. 17 ).
As shown in FIG. 17 , the adjusting screw 918 is a screw member that includes a head portion 9181 and a shaft portion 9183 . The head portion 9181 is a large-diameter component that the user may rotate by gripping the head portion 9181 with the fingers. The shaft portion 9183 is a small-diameter component that extends as a single piece from the head portion 9181 . A male threaded portion 9182 is formed from approximately the center of the axial direction of the shaft portion 9183 to the tip. A narrow groove 9184 , into which a retaining ring 9185 is fitted, is formed in the shaft portion 9183 in a location that is close to the head portion 9181 . The adjusting screw 918 may be mounted in the pair of the screw mounting portions 917 by passing the shaft portion 9183 through the hole 9171 and screwing the male threaded portion 9182 into the threaded hole in the nut that is embedded in the hole 9172 . In this state, the retaining ring 9185 may be fitted into the narrow groove 9184 of the shaft portion 9183 . The adjusting screw 918 is thus held such that the adjusting screw 918 can rotate in the screw mounting portion 917 on the side where the hole 9171 is located and cannot move in the axial direction.
In a case where the user grips the head portion 9181 with the fingers and rotates the adjusting screw 918 , the screw mounting portion 917 on the side where the hole 9172 is formed moves in the axial direction of the shaft portion 9183 , via the nut. The movement direction is determined by the rotation direction of the adjusting screw 918 . Thus the adjusting screw 918 can couple together the pair of the screw mounting portions 917 and can perform adjustment to increase or reduce the gap between the pair of the screw mounting portions 917 . By adjusting the gap between the pair of the screw mounting portions 917 , the diameter of the inner frame 91 can be adjusted in accordance with the thickness of the work cloth 100 . For example, by narrowing the gap between pair of the screw mounting portions 917 , the diameter of the inner frame 91 becomes smaller. As a result, the embroidery frame 9 can clamp the work cloth 100 having a greater thickness between the middle frame 92 and the inner frame 91 . Note that, for ease of explanation, the retaining ring 9185 has been omitted from FIG. 18 .
A mark 110 is provided on an upper face of the inner frame 91 . As shown in FIGS. 17 and 18 , the middle frame 92 includes the circular frame portion 921 , which has an inside diameter that is larger than the outside diameter of the frame portion 911 of the inner frame 91 . The middle frame 92 can be removably attached to the inner frame 91 by removably attaching the frame portion 921 of the middle frame 92 on the outer side of the frame portion 911 of the inner frame 91 in the radial direction. A large gear 934 is formed on the outer circumferential side face of the lower portion of the frame portion 921 of the middle frame 92 and is a gear that is formed around the entire circumference of the frame portion 921 . The large gear 934 can mesh with a small gear 948 (described later; refer to FIG. 18 ).
As shown in FIG. 17 , a flange portion 929 that projects to the outside in the radial direction around the entire circumference of the frame portion 921 is provided in a central portion in the axial direction of the outer circumferential side face of the frame portion 921 , on the upper side of the large gear 934 . A support portion 936 that projects to the inside in the radial direction around the entire circumference of the frame portion 921 is provided on the inner circumferential side face of the lower end of the frame portion 921 . The support portion 936 is a component that supports a lower end face of the inner frame 91 .
As shown in FIGS. 17 and 18 , the outer frame 94 includes the circular frame portion 941 . A support portion 946 that projects to the inside in the radial direction around the entire circumference of the frame portion 941 is provided on the inner circumferential side face of the lower edge of the frame portion 941 (refer to FIG. 17 ). The support portion 946 supports a lower end surface of the middle frame 92 and thus the frame portion 941 supports the middle frame 92 .
An attachment portion 942 and an attachment portion 950 are provided on the outer side of the frame portion 941 in the radial direction. The attachment portion 942 is configured to be detachably mounted on the right arm portion 97 of the movement mechanism 11 . The attachment portion 950 is configured to be detachably mounted on the left arm portion 98 of the movement mechanism 11 . A plate 951 that extends from the frame portion 941 to the attachment portion 950 is provided between the frame portion 941 and the attachment portion 950 . The plate 951 and the attachment portion 950 are joined by screws 952 .
A box-shaped housing portion 943 that joins the frame portion 941 and the attachment portion 942 is provided between the frame portion 941 and the attachment portion 942 . The housing portion 943 includes a projecting portion 954 that projects toward the outside in the radial direction of the frame portion 941 at the bottom end on the side of the attachment portion 942 of the housing portion 943 . The attachment portion 942 is disposed on the upper surface of the projecting portion 954 , and the attachment portion 942 and the housing portion 943 are joined by screws 953 .
A frame-side connector 944 is provided on one end (the end portion on the lower right side in FIG. 17 ) of the projecting portion 954 . The frame-side connector 944 is a convex connector. As shown in FIG. 18 , a sewing machine-side connector 352 , which is a concave connector to which the frame-side connector 944 can be coupled, is provided on the right arm portion 97 of the movement mechanism 11 of the sewing machine 1 . When the embroidery frame 9 is attached to the right arm portion 97 and the left arm portion 98 of the movement mechanism 11 , the frame-side connector 944 is coupled and electrically connected to the sewing machine-side connector 352 . The frame-side connector 944 is electrically connected to a motor 947 through a conductor wire 945 . The sewing machine-side connector 352 is connected to the CPU 61 through the I/O 66 (refer to FIG. 5 ) and a drive circuit (not shown in the drawings) that drives the motor 947 . When the frame-side connector 944 is connected to the sewing machine-side connector 352 , the CPU 61 can control the motor 947 .
As shown in FIG. 18 , the motor 947 is disposed in the housing portion 943 . The motor 947 is disposed in the housing portion 943 such that a rotating shaft of the motor 947 faces downward. The small gear 948 , which has a diameter that is smaller than that of the large gear 934 of the middle frame 92 , is fixed to the lower end of the rotating shaft of the motor 947 . The small gear 948 meshes with the large gear 934 . When the motor 947 is driven and the small gear 948 is rotated, the large gear 934 rotates. The middle frame 92 thus rotates in relation to the outer frame 94 .
A mode in which the inner frame 91 , the middle frame 92 , and the outer frame 94 are combined, and a mode in which the embroidery frame 9 is attached to the sewing machine 1 (the movement mechanism 11 ) will be explained. For example, the user may place the middle frame 92 on a work bench (not shown in the drawings) such that the large gear 934 is on the lower side. Then the user may place the work cloth 100 on the middle frame 92 . The user may insert the inner frame 91 into the inner side of the middle frame 92 while pressing the work cloth 100 downward with the bottom end of the inner frame 91 . The work cloth 100 may be thus clamped between the inner frame 91 and the middle frame 92 . At this time, the user may rotate the adjusting screw 918 as appropriate and adjust the diameter of the inner frame 91 in accordance with the thickness of the work cloth 100 . The face of the work cloth 100 on which the sewing will be performed may enter a state of being stretched taut on the inner side of the inner frame 91 at the bottom end of the inner frame 91 . In the explanation that follows, the frame that is formed by combining of the inner frame 91 and the middle frame 92 is referred to as an assembled unit 95 (refer to FIG. 18 ).
Next, the user may place the assembled unit 95 into the outer frame 94 from the top side of the outer frame 94 . At this time, the user may place the assembled unit 95 in the frame portion 941 such that the large gear 934 and the small gear 948 mesh with each other. Thus the large gear 934 and the small gear 948 may be meshed with each other, and the middle frame 92 (the assembled unit 95 ) may be locked with the outer frame 94 . The inner frame 91 , the middle frame 92 , and the outer frame 94 can be thus combined to produce the completed form of the embroidery frame 9 .
The user may attach the completed form of the embroidery frame 9 to the sewing machine 1 by attaching the attachment portions 942 , 950 of the embroidery frame 9 to the right arm portion 97 and the left arm portion 98 of the movement mechanism 11 . In the process, the sewing machine-side connector 352 that is provided in the right arm portion 97 and the frame-side connector 944 that is provided in the attachment portion 942 are connected electrically (refer to FIG. 18 ). Thus the CPU 61 can control the drive circuits and control the motor 947 through the sewing machine-side connector 352 , the frame-side connector 944 , and the conductor wire 945 . By controlling the motor 947 , the CPU 61 can rotate and lock the middle frame 92 (the assembled unit 95 ) in relation to the outer frame 94 .
A cutting blade data table 48 shown in FIG. 19 will be explained. The cut lengths that can be formed in the work cloth 100 by the cutting blades 52 ( 531 to 533 ) that, among the needle bars 71 to 78 , are attached to the needle bars 71 to 73 are registered in the cutting blade data table 48 . The registered cut lengths are values that the user has input by panel operations. In the second embodiment, the cutting blade 531 , with a cut length of 1.5 millimeters, is attached to the needle bar 71 of the sewing machine 1 . The cutting blade 532 , with a cut length of 3 millimeters, is attached to the needle bar 72 . The cutting blade 533 , with a cut length of 4.5 millimeters, is attached to the needle bar 73 . The cutting blades 52 are not attached to the needle bars 74 to 78 . As shown in FIG. 19 , in the cutting blade data table 48 , the cut lengths of 1.5 millimeters, 3 millimeters, and 4.5 millimeters are associated with the needle bars 71 to 73 , respectively. In FIG. 19 , a “−” indicates that data have not been registered in the cutting blade data table 48 . Note that the cut angles for the cutting blades 531 to 533 described above are all zero degrees.
Second main processing in the second embodiment will be explained with reference to FIG. 20 . In the second main processing, processing steps that are the same as in the first main processing in the first embodiment are indicated by the same step numbers, and detailed explanations will be omitted. In the second main processing, in the same manner as in the first main processing, the CPU 61 determines whether the pattern data have been acquired (Step S 11 ). In a case where the pattern data have been acquired (YES at Step S 11 ), the CPU 61 stores the acquired pattern data in the RAM 63 (Step S 12 ). In the explanation that follows, the example in which the pattern data for the pattern line 101 shown in FIG. 7 are acquired will be used, in the same manner as in the first embodiment.
The CPU 61 determines whether a minimum rotation angle has been input (Step S 31 ). The minimum rotation angle is input by the user through a panel operation, for example. The minimum rotation angle is the smallest rotation angle by which the embroidery frame 9 can rotate. In the present embodiment, the sewing machine 1 can control the rotation of the embroidery frame 9 as desired by using the motor 947 . Therefore, the minimum rotation angle is 1 degree. Note that, for example, in a case where a rotation angle of 45 degrees is input by the user as the minimum rotation angle, the minimum rotation angle is 45 degrees.
In a case where the minimum rotation angle has not been input (NO at Step S 31 ), the CPU 61 repeats the processing at Step S 31 . In a case where the minimum rotation angle has been input (YES at Step S 31 ), the CPU 61 stores the acquired minimum rotation angle in the RAM 63 (Step S 32 ). In the present embodiment, an example is used in which 1 degree has been input as the minimum rotation angle.
The CPU 61 identifies the minimum cut length in the same manner as in the first embodiment (Step S 13 ). The CPU 61 identifies the identified minimum cut length as the cut length L and stores the identified cut length L in the cutting blade data table 48 (Step S 14 ). The cut lengths that are associated with the needle bars 7 in the cutting blade data table 48 are computed as multiples of the minimum cut length L. Based on the computed multiples, the CPU 61 stores the cut lengths that are different from the minimum cut length L in the cutting blade data table 48 (Step S 15 ). In this manner, the cut lengths L, 2L, 3L are respectively associated with the needle bars 71 , 72 , 73 , as shown in FIG. 21 .
The CPU 61 sets the needle drop points consecutively at the predetermined intervals (the minimum cut length L) along the pattern line 101 (Step S 16 ). Thus the needle drop points QX (X=1, 2, 3 . . . 73) shown in FIG. 9 are set. In the second embodiment, the coordinates of the set needle drop points Q 1 to Q 73 are registered in a cut data table 49 (refer to FIG. 22 ) and stored in the RAM 63 .
The CPU 61 sets the cut angle for each of the needle drop points QX that were set by the processing at Step S 16 (Step S 33 ). In the processing at Step S 33 , the rotation angle that is the closest to the direction in which the pattern line 101 extends at the needle drop point QX is selected from among the rotation angles to which the embroidery frame 9 can be rotated and set as the cut angle. In other words, the rotation angle of the embroidery frame 9 is set. Specifically, first, as shown in FIG. 11 , the line segments 111 , 112 , 113 are defined that connect two adjacent needle drop points QX (Q 4 to Q 5 , Q 5 to Q 6 , and Q 6 to Q 7 ). In the present embodiment, the minimum rotation angle that was stored by the processing at Step S 32 is 1 degree. Therefore, the embroidery frame 9 can be rotated by 1 degree at a time. For example, in a case where the direction in which the line segment 111 extends is 88 degrees, the cut angles for the needle drop points Q 4 , Q 5 positioned at both ends of the line segment 111 are each set to 88 degrees. In the same manner, in a case where the direction in which the line segment 112 extends is 75 degrees, the cut angles for the needle drop points Q 5 , Q 6 positioned at both ends of the line segment 112 are each set to 75 degrees. In a case where the direction in which the line segment 113 extends is 62 degrees, the cut angles for the needle drop points Q 6 , Q 7 positioned at both ends of the line segment 113 are each set to 62 degrees. The cut angles are set in the same manner for all of the other needle drop points QX. The cut angles that have been set are registered in the cut data table 49 , as shown in FIG. 23 . Note that in a case where the minimum rotation angle is 5 degrees and the direction in which a line segment extends in 13 degrees, for example, the cut angles for the needle drop points QX positioned at both ends of the line segment may be set to 15 degrees, which is the closest possible rotation angle to 13 degrees.
The CPU 61 sets (adjusts) the positions (the coordinates) of the needle drop points QX to match the cut angles (the rotation angles) (Step S 34 ). The coordinates of the needle drop points QX were set by the processing at Step S 16 (refer to FIG. 23 ) without taking into account the fact that the embroidery frame 9 (the assembled unit 95 ) may be rotated. Therefore, in a case where the embroidery frame 9 is rotated, the coordinates of the needle drop points QX in the cut data table 49 and the actual positions of the needle drop points QX may be different. Therefore, at Step S 34 , the post-rotation coordinates of the needle drop points QX are set. The coordinates of the needle drop points QX in the cut data table 49 shown in FIG. 23 are adjusted as shown in FIG. 24 by the processing at Step S 34 . For example, as shown in FIG. 23 , the cut angle (the rotation angle) for the needle drop point Q 17 (X 17 , Y 17 ) is 45 degrees. Therefore, the coordinates for the needle drop point Q 17 are set to (X 17 cos 45°−Y 17 sin 45°, X 17 sin 45°+Y 17 cos 45°), as shown in FIG. 24 . Note that in a case where two cut angles are associated with one needle drop point, as 90 degrees and zero degrees are associated with the needle drop point Q 1 , the coordinates of the needle drop point Q 1 are set separately for each of the two cut angles (refer to FIG. 24 ).
The CPU 61 performs the processing at Steps S 18 to S 27 in the same manner as in the first embodiment. In the processing at Step S 26 , at least a part of the consecutive needle drop points QX for which the cut angles are the same are consolidated into the single needle drop point QX′, based on the cut lengths that are registered in the cutting blade data table 48 . For example, in the cut data table 49 (refer to FIG. 24 ), the cut angle 45 degrees is acquired for each of the needle drop points Q 17 to Q 28 (Step S 22 ). Next, the cutting blade data table 48 is referenced, and from among the cut lengths that are associated with the acquired cut angle of 45 degrees, the cut length 3L is identified as the cut length for which the multiple is closest to the variable P while not exceeding the value of the variable P. The needle drop points Q 17 to Q 28 are set consecutively at intervals of the minimum cut length L. Therefore, the CPU 61 consolidates three of the consecutive needle drop points QX that are associated with the cut length L into the single needle drop point QX′ with the cut length 3L. That is, the CPU 61 computes the intermediate point among the three needle drop points QX and then consolidates the three needle drop points QX into the one needle drop point QX′ at the computed intermediate point. The intermediate point among the three needle drop points QX is specifically the intermediate point between the needle drop point QX with the lowest number QX among the three needle drop points QX and the needle drop point QX with the highest number QX.
For example, in the case of the needle drop points Q 17 to Q 19 , the coordinates for the needle drop point Q 17 are (X 17 cos 45°−Y 17 sin 45°, X 17 sin 45°+Y 17 cos 45°), and the coordinates for the needle drop point Q 19 are (X 19 cos 45°−Y 19 sin 45°), X 19 sin 45°+Y 19 cos 45°). A needle drop point Q 17 ′ is computed as the intermediate point among the needle drop points Q 17 to Q 19 . Accordingly, the three needle drop points Q 17 to Q 19 shown in FIG. 24 are consolidated into the needle drop point Q 17 ′, as shown in FIG. 25 . For the needle drop point Q 17 ′, the X coordinate is {(X 17 +X 19 )cos 45°−(Y 17 +Y 19 )sin 45°}/2, and the Y coordinate is {(X 17 +X 19 )sin 45°+(Y 17 +Y 19 )cos 45°}/2. Note that, for example, in a case where two consecutive needle drop points QX with the same cut angle remain after three of the needle drop points QX have been consolidated into a single needle drop point QX′, the intermediate point between those remaining two needle drop points QX is computed. Based on the cut length 2L, the two adjacent needle drop points QX are consolidated into a needle drop point QX′ at the computed intermediate point. The cutting sequence number is changed in the order of the X values of the needle drop points QX and QX′. The other needle drop points QX are also consolidated into the needle drop points QX′ in the same manner.
FIG. 26 is a figure that shows the needle drop points QX′ that have been consolidated by the processing at Step S 26 , as well as the unconsolidated needle drop points QX, on the pattern line 101 . As shown in FIG. 26 , the groups of three consecutive needle drop points QX and two consecutive needle drop points QX for which the cut angles are the same are each consolidated into the single needle drop points QX′. Therefore, the total number of the needle drop points QX and the needle drop points QX′ is less than the number of the needle drop points before the processing at Step S 26 was performed (refer to FIG. 9 ). Note that in FIG. 26 , the needle drop point Q 44 ′ and the needle drop point Q 72 ′ are needle drop points into each of which two of the needle drop points QX have been consolidated.
In the processing at Step S 27 , for each of the needle drop points QX′ that were consolidated and at the needle drop points QX that were not consolidated by the processing at Step S 26 , one of the needle bars 7 to which one of the cutting blades 52 is attached is set from among the plurality of needle bars 71 to 78 and is registered in the cut data table 47 . For example, the needle drop point Q 17 ′, which was consolidated (the position (coordinates) was changed) by the processing at Step S 26 , is the needle drop point QX′ into which the three needle drop points Q 17 to Q 19 were consolidated. That is, the three needle drop points corresponding to a cut length 3L as a whole was consolidated into the single needle drop point Q 17 ′. Accordingly, the cutting blade data table 48 (refer to FIG. 21 ) is referenced, and the needle bar 73 , to which the cutting blade 533 with the cut length 3L is attached, is set for the needle drop point Q 17 ′. Then the needle bar 73 is registered in the cut data table 49 in association with the needle drop point Q 17 ′, as shown in FIG. 27 . Note that each of the needle drop point Q 44 ′ and the needle drop point Q 72 ′ is the needle drop point QX′ into which two of the needle drop points QX were consolidated, although this is not shown in the drawings. Therefore, the needle bar 72 , to which the cutting blade 532 with the cut length 2L is attached, is registered in association with the needle drop point Q 44 ′ and the needle drop point Q 72 ′.
When the CPU 61 has performed the processing at Steps S 22 to S 27 for all of the needle drop points QX, the CPU 61 determines that the data do not exist for the cutting sequence number that corresponds to the variable N (NO at Step S 21 ) and, in the same manner as in the first embodiment, changes the cutting order for the needle drop points QX and the needle drop points QX′ such that the same cutting blade 52 is to be used consecutively when the sewing machine 1 is operated (Step S 28 ). The cut data table 49 after the cutting order changed is omitted from the drawings. In the same manner as in the first embodiment, the CPU 61 causes the sewing machine 1 to perform the forming of the cuts along the pattern line 101 in accordance with the cutting order in the cut data table 49 (Step S 29 ). In the second embodiment, the motor 947 is controlled, and the embroidery frame 9 (the assembled unit 95 ) is rotated to the cut angle (the rotation angle). The movement mechanism 11 is driven, and the embroidery frame 9 is moved such that the needle bar 7 (the cutting blade 52 ) is positioned directly above the position indicated by the coordinates of the needle drop point QX or QX′. Then, the work cloth 100 is pierced by the cutting blade 52 at the needle drop point QX or QX′, and the cut is formed in the work cloth 100 . In a case where the operating of the needle bar 7 that corresponds to the last cutting sequence number has been finished, the CPU 61 terminates the second main processing.
The processing in the second embodiment is performed as described above. In the present embodiment, the same effects as those achieved in the first embodiment can be produced using the rotatable embroidery frame 9 .
Note that the present disclosure is not limited to the embodiments that are described above, and various types of modifications can be made. For example, the cut data may be generated by an external device instead of by the sewing machine 1 . For example, a device such as a portable terminal, a personal computer, or the like, may be used as the external device. A CPU that is provided in the device may perform the processing that generates the cut data tables 47 , 49 in the first main processing and the second main processing. In that case, the device may, for example, transmit the generated cut data tables 47 , 49 to the sewing machine 1 , and the sewing machine 1 may perform the sewing.
It is also acceptable, for example, for the cut length not to be the same as the cutting edge width of the cutting blade 52 . For example, the user may attach a blade that has a V-shaped cutting edge to a tip of the needle bar. The sewing machine 1 may then cause the needle bar to move up and down such that the work cloth 100 is pierced up to the midpoint of the blade. In that case, the cut length that is formed in the work cloth 100 is shorter than the cutting edge width. The needle bar may also be structured such that the mounting position (the mounting height) of the cutting blade can be changed. In that case, the user can change the amount by which the cutting blade pierces the work cloth 100 . Therefore, the user can change the cut length, as desired.
It is also not necessary for the cutting order for the needle drop points QX and the needle drop points QX′ to be changed such that the same cutting blade 52 is consecutively used. For example, the sewing machine 1 may also form the cuts in the work cloth 100 using the cut data tables 47 , 49 that are generated by the processing at Step S 27 , without performing any processing that is equivalent to the processing at Step S 28 .
The embroidery frame 9 (the assembled unit 95 ) in the second embodiment is configured to be rotated by the rotation of the motor 947 . However, same sort of processing as the second main processing may be performed with an embroidery frame that is rotated by hand of the user, for example. In that case, in a case where the CPU 61 of the sewing machine 1 performs the cutting processing in the processing at Step S 29 of the second main processing (refer to FIG. 20 ), the angle to which the embroidery frame to be rotated may be displayed on the liquid crystal display 15 , prompting the user to perform the rotation operation. The sewing machine 1 may also be provided with a camera. The sewing machine 1 may use the camera to capture an image of the mark 110 , then detect the rotation angle of the embroidery frame 9 based on the position of the mark 110 in the captured image. Based on the detected rotation angle, the sewing machine 1 may then display the current rotation angle and the target rotation angle on the liquid crystal display 15 , thus prompting the user to perform the rotation operation for the embroidery frame 9 .
The apparatus and methods described above with reference to the various embodiments are merely examples. It goes without saying that they are not confined to the depicted embodiments. While various features have been described in conjunction with the examples outlined above, various alternatives, modifications, variations, and/or improvements of those features and/or examples may be possible. Accordingly, the examples, as set forth above, are intended to be illustrative. Various changes may be made without departing from the broad spirit and scope of the underlying principles.
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An apparatus includes a processor and a memory configured to store a plurality of cut length data items and a computer-readable instructions that instruct the apparatus to execute steps comprising acquiring pattern data, setting, as a plurality of first needle drop points, a plurality of points on the pattern line at predetermined intervals, setting a cut angle corresponding to each of the plurality of first needle drop points, determining a plurality of second needle drop points among the plurality of first needle drop points, consolidating, based on the plurality of cut length data items, at least some of the plurality of second needle drop points into at least one third needle drop point, identifying a cutting blade corresponding to each of a plurality of fourth needle drop points among the plurality of cutting blades based on the plurality of cut length data items, and generating cut data.
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This application claims priority from U.S. Provisional Application No. 60/220,576, filed Jul. 25, 2000, which is hereby incorporated by reference.
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates to drill bits used in oil and gas drilling, and especially to the use of inserts and hardfacings thereon.
BACKGROUND
Rotary Drilling
Oil wells and gas wells are drilled by a process of rotary drilling, using a drill rig such as is shown in FIG. 4 . In conventional vertical drilling, a drill bit 410 is mounted on the end of a drill string 412 (drill pipe plus drill collars), which may be miles long, while surface equipment 414 turns the drill string, including the bit at the bottom of the hole.
Two main types of drill bits are in use, one being the roller cone bit, an example of which is seen in FIG. 6 . In this bit a set of cones 616 (two are visible) are arranged on rugged bearings such that when the drill string to which they are connected is rotated, each cone will separately rotate about its separate axis along the bottom of the borehole. The cones will generally have either milled teeth cut out of the same steel of which the cones are made or inserts 12 of a harder material than the steel cone. The teeth generally work in a gouging, scraping motion to remove softer formations, while inserts are generally preferred for harder formations, where their hardness, combined with the weight on the bit, acts to fracture the rock, which is then swept by the circulating mud.
The second type of drill bit is a drag bit, having no moving parts, seen in FIG. 5 . These bits are increasingly popular, especially in softer formations. Like rotary cone bits, they can also carry either milled teeth or harder inserts.
During drilling operations, drilling fluid, commonly referred to as “mud”, is pumped down through the drill string and out nozzles 628 in the drill bit. The flow of the mud is one of the most important factors in the operation of the drill bit, serving to remove the cuttings which are sheared from rock formations by the drill bit, to cool the drill bit and teeth, and to wash away accumulations of soft material which can clog the bit.
When the bit wears out or breaks during drilling, it must be brought up out of the hole. This requires a process called “tripping”: a heavy hoist pulls the entire drill string out of the hole, in stages of (for example) about ninety feet at a time. After each stage of lifting, one “stand” of pipe is unscrewed and laid aside for reassembly (while the weight of the drill string is temporarily supported by another mechanism). Since the total weight of the drill string may be hundreds of tons, and the length of the drill string may be tens of thousands of feet, this is not a trivial job. One trip can require tens of hours and is a significant expense in the drilling budget. To resume drilling the entire process must be reversed. Thus the bit's durability is very important, to minimize round trips for bit replacement during drilling.
Tungsten Carbide Inserts
The inserts or compacts used in drill bits are made of a super-hard material and a softer binder material which are formed into the desired shape at very high temperatures and pressures. The normal composition is tungsten carbide and from 5 to 17% cobalt in a sintered condition. The inserts are press-fitted into holes drilled into the drill bit. In recent years inserts have been added to areas of steel tooth roller cone bits. A common problem associated with the placement of these inserts and those on other bits is that the steel holding the insert in place erodes and leaves the insert in peril of damage or simply falling out from its pocket. FIG. 7 gives an example of how erosion weakens the area around an insert. In this drawing, body areas 710 adjacent the insert 12 have been washed away by the scouring action of abrasives carried in the drilling mud. If the insert does come out, it does more than simply leave the bit with one less cutting element. The inserts tend to be very dense and is not easily carried away by the drilling mud. Rather, it tends to stay near the bottom of the hole, where its hard nature causes it to knock out following teeth and to quickly destroy the bit. Often, not only must the bit be replaced, but fishing tools can be necessary to remove broken teeth from the hole prior to the resumption of drilling.
Hardfacings
It has become common to coat areas of a bit which are subject to erosion with a layer of hardfacing. An exemplary hardfacing comprises tungsten carbide in a matrix of steel, which is applied to the finished bit by welding. While hardfacings are being used in many high-wear areas of the bit, it has been difficult to apply hardfacings near inserts. This is because the inserts, which are press-fitted into their holes, are often loosened by the heating used in the application of the hardfacing, a counter-productive activity. To prevent this, a margin has generally been left around the inserts when hardfacing is applied.
Thermal spray coatings, such as that shown in U.S. Pat. No. 5,535,838, have been applied over the cutting structure but because of the relative thin layer (0.005″ to 0.020″) there is minimum protection of the insert and no contribution to the metallurgical bonding of the insert. Thermal spray coatings are not appropriate for steel tooth roller cone rock bits or areas of high wear such as the gage area of a fixed cutter bit or the surf or backface area of a roller cone.
Improved Wear Protection on Rock Bits
The present inventor has realized that wear protection on rock bits can be enhanced by combining features of superhard inserts and deposited hardfacing layers. In order to combine the two, the inserts are welded into place. They may be welded using a hardfacing or weld material or a combination of both. The compacts used can be ordinary compacts or they can be specifically modified to improve their weldability. After the inserts are welded into place, additional hardfacing material is applied to the bit, including the areas immediately adjacent to and even over the inserts. This method produces parts with inserts which are not destroyed during hardfacing and heat treat, as opposed to present methods in which either hardfacings OR pressed inserts alone are used in these high wear areas.
The disclosed innovations, in various embodiments, provide one or more of at least the following advantages:
ability to intimately combine inserts and hardfacings;
metal supporting the insert is protected from erosion;
inserts are less likely to come out of socket;
savings in time/money from retention of inserts.
BRIEF DESCRIPTION OF THE DRAWING
The disclosed inventions will be described with reference to the accompanying drawings, which show important sample embodiments of the invention and which are incorporated in the specification hereof by reference, wherein:
FIG. 1 shows an embodiment of a rotary cone from a drill bit, showing how the teeth both contain inserts and are covered by hardfacing.
FIG. 2A shows one embodiment of a tooth containing an insert which is covered by the hardfacing.
FIG. 2B shows an alternate embodiment of a tooth containing two inserts which are covered by the hardfacing.
FIG. 3A shows an example of the disclosed combination of inserts and hardfacing being used in a stabilizer pad on a rotary cone drill bit or in a gauge pad on a fixed head drill bit.
FIG. 3B shows an example of the disclosed combination of inserts and hardfacing being used on the backface (surf row) on a roller cone bit.
FIG. 4 shows an exemplary drill rig.
FIG. 5 shows an exemplary fixed cutter drill bit.
FIG. 6 shows an exemplary rotary cone drill bit.
FIG. 7 shows how erosion weakens the area around an insert.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The numerous innovative teachings of the present application will be described with particular reference to the presently preferred embodiment (by way of example, and not of limitation).
This invention specifically addresses the need to enhance the performance of all types of rock drilling bits by allowing the placement of super-hard wear-resistant inserts or segments in areas of high wear, while at the same time, protecting the surrounding area from erosion and providing a metallurgical bond between the insert and the steel body. The intention is to provide maximum wear protection to the high wear areas, such as cutting structures and gage areas on a rock bit, where the wear slows down the penetration rate of the bit and reduces bit life. This is accomplished by welding the highly wear-resistant inserts or segments in these critical wear areas so that one can bring the hardfacing all the way up to the insert or even over it. By bringing the hardfacing into direct contact with the insert, the wear resistance is improved over the current solution of putting the maximum amount of hardfacing in the same area. The insert or segment, because of its composition, can be metallurgically bonded to the hardfacing material and through it to the material of the bit. The insert is more wear resistant than the surrounding hardfacing, thus extending the life of these high wear areas. By encapsulating the insert with hardfacing, the insert and its surrounding area is also protected from erosive wear, which is not the case for a standard pressed insert.
Weldable Insert
The compacts used can be ordinary compacts or they can be specifically modified to improve their weldability. For instance, they can have a weldable coating or sleeve. They can be higher in the matrix material (cobalt, nickel, etc.) than ordinary compacts. They can have ceramic materials (diamonds, etc.) in the carbide substrate with varying matrix materials and matrix percentages.
In the presently preferred embodiment, the insert is composed of tungsten carbide and diamond particles in a cobalt matrix, such as those disclosed in U.S. Pat. No. 6,102,140, which is owned by the assignee of this application and which is hereby incorporated by reference.
For the wear-resistant materials, other acceptable materials include carbides, nitrides, borides, carbonitrides, suicides of tungsten, niobium, vanadium, hafnium, zirconium, chromium, boron, diamond composites, carbon nitride, and mixtures there of. Alternate matrix materials can be cobalt, nickel, copper, iron, or an alloy of any of these. The percent of matrix material in the insert can range from 3% to 50%, with the presently preferred range of 15% to 30%.
The insert (or compact) can be coated or sleeved with a Co, Ni, Cu or Fe based material to protect and aid in the metallurgical bonding process of the insert to the hard metal or weld material and to the base material. This coating or sleeve can be applied by pressing and/or sintering, powder metallurgy, plating, thermal spray, etc., according to known methods. Depending on the method of forming the coating or sleeve, this step can be done while the compact is being formed or afterwards.
The shape of the insert can be rectangular, round, square, triangular or any combination of shape (e.g., a round dowel shaft with an angular flat top). The thickness or diameter of the insert can range from 0.10-1.0 inches. The insert size and location can cover from 1% to 100% of the rock bit cutting structure and gage dimensional areas.
The preferred location of the insert is at the point of contact with the formation. The insert may sit on the leading face, be recessed on the leading face, or in a slot or hole. Inserts can be welded within all teeth or blades or on only some of the teeth or blades on the bit.
Welding/Hardfacing of Insert
The preferred method for welding the insert to the gage tooth is the oxyfuel process using a tube material containing tungsten carbide and diamond particles in an iron matrix. In the presently preferred embodiment of the weld material, tungsten carbide comprises 65-75% and diamond particles comprise 5-10%; the rest of the weld material will be the iron matrix.
Alternate processes and techniques for the application of the hardfacing or weld material are well known to the art. Using these processes and techniques can create a metallurgical bond between the hardfacing or weld material, the insert, and the base material. It is also possible, although not necessary to the practice of the invention, to alter either the composition of the insert or of the weld/hardfacing material to improve the metallurgical bonds.
One alternate technique of hardfacing uses the oxyfuel or atomic hydrogen process with a tube material containing ceramic or carbide particles in a Co, Ni, Cu or Fe based matrix. A second technique is the Thermal Spray Fuse or Plasma Transfer Arc process using powders containing ceramic or carbide particles in a Co, Ni, Cu, or Fe based matrix. A third technique is an arc welding process, such as shielded metal arc welding (SMAW), gas tungsten arc welding (GTAW), gas metal arc welding (GMAW), flux core arc welding (FCAW), and pulse gas metal arc welding (pulse GMAW), using a welding consumable containing ceramic or carbide particles in a Co, Ni, Cu or Fe based matrix. All techniques and processes can also be used with a welding consumable composed of a Co, Ni, Cu, or Fe based alloy without ceramic or carbide particles in their composition.
FIG. 3A shows an example of the disclosed combination of inserts and hardfacing being used in a stabilizer pad on a rotary cone drill bit or in a gauge pad on a fixed head drill bit.
Sample Embodiment: Roller-Cone Bit
In an exemplary embodiment for a roller cone, shown in FIG. 1, the teeth 10 both contain inserts 12 and are covered by hardfacing 14 . Inserts 12 placed in the inner row teeth will extend to the surface of the hardfacing 14 or slightly below the surface of the hardfacing. In several test bits, the inserts 12 A in the inner rows were placed slightly below the hardfacing 14 surface for appearance reasons, and for ease of application of the hardfacing (it was easier for hardfacing operators to weld over the inserts than weld up to them). However, it is preferred to have the inserts as close to the surface as possible. FIG. 2A shows an embodiment of a tooth containing a single insert which is covered by the hardfacing. FIG. 2B shows an alternate embodiment of a tooth containing two inserts covered by the hardfacing.
The compacts or inserts 12 B placed at the heel area of the gage teeth and in the gage surfaces are ground after the hardfacing application to ensure that the gage will not be oversize. Therefore, these inserts are placed in their slots or holes so they will be exposed to the surface after gage grind. These inserts can be seen in FIG. 1, or in FIG. 3B, which shows the back side (surf row) on a roller cone bit.
Sample Embodiment: Fixed-Cutter Bit
FIG. 3A shows an exemplary gage pad for a fixed-cutter bit. Gage inserts 12 B, like their roller cone counterparts, are ground after hardfacing, and are placed to be exposed after gage grind.
According to a disclosed class of innovative embodiments, there is provided: A drill bit comprising: a body having an first end configured for attachment to a drill string and a second end, opposite said first end, for removing material from a borehole; a plurality of inserts embedded in said second end of said body, said inserts comprising a material which is harder than said body; hardfacing which covers at least a portion of said body, said hardfacing being immediately adjacent said plurality of inserts.
According to another disclosed class of innovative embodiments, there is provided: A downhole component for use in drilled boreholes in rock, comprising: a body which carries one or more functional components; a mechanical connection for supporting said body within the borehole; and abrasion-resistant surfaces on said body, at points where said body can contact said borehole, comprising at least one insert of a material which is harder than said body, and encapsulation material which is softer than said insert and which laterally surrounds said insert wherever said insert protrudes from a surface of said body.
According to another disclosed class of innovative embodiments, there is provided: A rotary drilling system, comprising: a drill string which is connected to conduct drilling fluid to a bit from a surface location; and a rotary drive which rotates at least part of said drill string together with said bit; a drill bit which is attached to said drill string for removing rock when rotating; a plurality of inserts welded in said drill bit, said inserts comprising a material which is harder than said drill bit; hardfacing which covers at least a portion of said drill bit which is intimately attached to one of said plurality of inserts.
According to another disclosed class of innovative embodiments, there is provided: A method for fabricating a drill bit, said method comprising the steps of: forming a body of said drill bit; forming a plurality of holes in portions of said body to receive inserts which are harder than said body; fastening a plurality of inserts in said holes; coating portions of said drill bit with a hardfacing material, wherein at least one of said inserts is in intimate contact with said hardfacing material.
Modifications and Variations
As will be recognized by those skilled in the art, the innovative concepts described in the present application can be modified and varied over a tremendous range of applications, and accordingly the scope of patented subject matter is not limited by any of the specific exemplary teachings given.
It is also specifically contemplated that the disclosed inventions are not limited to drill bits, but can be used in core bits, reamers, and hole openers, and similar equipment.
It is also specifically contemplated that the disclosed inventions are not limited to components which themselves remove rock, but can be used in downhole motors, bent subs, workover tools, or wherever else great abrasion resistance is needed. This is particularly advantageous at maximum-diameter points of drill string components where contact with rock can be expected.
Additional general background, which helps to show the knowledge of those skilled in the art regarding implementation options and the predictability of variations, may be found in the following publications, all of which are hereby incorporated by reference: Baker, A Primer of Oilwell Drilling (5.ed. 1996); Bourgoyne et al., Applied Drilling Engineering (1991); Davenport, Handbook of Drilling Practices (1984); Drilling (Australian Drilling Industry Training Committee 1997); Fundamentals of Rotary Drilling (ed. W. W. Moore 1981); Harris, Deepwater Floating Drilling Operations (1972); Maurer: Advanced Drilling Techniques (1980); Nguyen, OIL AND GAS FIELD DEVELOPMENT TECHNIQUES: DRILLING, (1996 translation of 1993 French original); Rabia, Oilwell Drilling Engineering/Principles and Practice (1985); Short, Introduction to Directional and Horizontal Drilling (1993); Short, Prevention, Fishing & Repair (1995); Underbalanced Drilling Manual (Gas Research Institute 1997); the entire PetEx Rotary Drilling Series edited by Charles Kirkley, especially the volumes entitled MAKING HOLE (1983), DRILLING MUD (1984), and THE BIT (by Kate Van Dyke, 4.ed. 1995); the SPE reprint volumes entitled “Drilling,” “Horizontal Drilling,” and “Coiled-Tubing Technology”; and the Proceedings of the annual IADC/SPE Drilling Conferences from 1990 to date; all of which are hereby incorporated by reference.
None of the description in the present application should be read as implying that any particular element, step, or function is an essential element which must be included in the claim scope: THE SCOPE OF PATENTED SUBJECT MATTER IS DEFINED ONLY BY THE ALLOWED CLAIMS. Moreover, none of these claims are intended to invoke paragraph six of 35 USC section 112 unless the exact words “means for” are followed by a participle.
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Using inserts which are welded in place allows the use of hardfacing in the immediate vicinity of the inserts. Areas of high wear, such as cutting structures and gage areas, can use a combination of ultra-hard inserts with hardfacing for protection against wear. The inserts slows wear, while the hardfacing prevents erosion around the inserts.
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FIELD OF THE INVENTION
The present invention relates to a web-based application for developing structured query language to configure a relational data base without changing the source code and while the web-based application is running.
BACKGROUND OF THE INVENTION
A relational database stores information in tables consisting of rows and columns of data. When an application requests information from a relational database, the relational data base matches information from a field in one table with information in a corresponding field of another table to produce a third table that combines requested data from both tables. A problem arises when it is desired to make a change in a running web based application searching a relational data base. In order to make a change, the application searching the relational data base must be stopped so that the application property files can be accessed and structured query language (SQL) code written. What is needed is a way to reconfigure the running application without stopping it.
SUMMARY OF THE INVENTION
The invention which meets the needs identified above is a Configuration Application running on a server that responds to a web client. The Configuration Application has a Bean Configuration Utility, a Program Bean and one or more SectionBeans within the Program Bean. The Configuration Application has a graphical user interface for the user to select tables, join tables, select columns, review a conditional SQL statement at the graphical user interface, and save the SQL statement. The SQL statement is generated by the Bean Configuration Utility and the Program Bean. The SectionBean stores components needed to create a valid SQL statement. The components stored in the SectionBean includes without limitation columns, tables, filters, and table joining information. The SectionBean contains methods to generate the statement using stored components in the SectionBean. The Bean stores one or more SectionBeans. The Program Bean contains methods to get a SectionBean and to call that SectionBean's generate SQL method to return a valid SQL statement to the calling program. The Bean Configuration Utility is a program application that is used to create new SectionBeans or to configure existing SectionBeans. The Bean Configuration Utility can configure a SectionBean running on a server or configure and save a SectionBean that is stored to the file system. The Configuration Application, running on a server, loads the Program Bean and uses the Program Bean to process requests coming from web clients. The Configuration Application is programmed to read the information stored in the bean to generate SQL statements, and thus avoids hard coding SQL statements in the code or in a property file. Configuration to the Program Bean is made only by the Bean Configuration Utility. Using the graphical user interface, the user at the client computer can manipulate tho Program Bean to return custom fields from the database without a change to the running application itself. The Program Bean is serialized and can be saved to a file, database, or it can be sent through a network socket (TCP/IP).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a distributed data processing system in which the invention may be implemented;
FIG. 2 depicts a server computer in which the software to implement the server portion of the invention may be stored;
FIG. 3 depicts a computer in which the software to implement the user portion of the invention may be stored;
FIG. 4 is a flowchart of the user program;
FIG. 5A depicts an exemplary graphical user interface showing available tables;
FIG. 5B depicts an exemplary graphical user interface showing joining of tables;
FIG. 5C depicts an exemplary graphical user interface showing selection of columns;
FIG. 5D depicts an exemplary graphical user interface showing SQL generation;
FIG. 5E depicts an exemplary SQL statement generated by the invention; and
FIG. 6 is a flowchart showing the server program.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As used herein, the term “back end storage” means a relational data base accessed by a server computer and that contains the data for a particular web-based application.
As used herein, the term “bean” means a reusable independent code segment of an application according to Java component architecture defined by Sun Microsystems.
As used herein, the term “section bean” means a bean that has been configured for a specific data request. Multiple section beans can be contained in a “program bean.” For example, one section bean will contain one section of data for one program and another section bean will contain another section of data for another program
As used herein, the term “program bean” means a bean containing one or more section beans for storing information on the database columns and conditions.
As used herein, the term “serialize” means saving a bean object's instance variables which define the bean's current state and saving the bean's current state as a sequence of bytes that can be sent over a network or saved to a file. As used herein the term “serialized bean” means a serialized bean object that can be saved to a file, sent to a data base, or e-mailed.
FIG. 1 depicts a pictorial representation of a distributed data processing system in which the present invention may be implemented and is intended as an example, and not as an architectural limitation, for the processes of the present invention. Distributed data processing system 100 is a network of computers which contains a network 102 , which is the medium used to provide communication links between the various devices and computers connected together within distributed data processing system 100 . Network 102 may include permanent connections, such as wire or fiber optic cables, or temporary connections made through telephone connections. In the depicted example, a server 104 is connected to network 102 along with back end storage unit 106 and Direct Access Storage Device (DASD) 114 . In addition, clients 108 , 110 , and 112 also are connected to a network 102 . Clients 108 , 110 , and 112 may be, for example, personal computers or network computers.
For purposes of this application, a network computer is any computer, coupled to a network, which receives a program or other application from another computer coupled to the network. In the depicted example, server 104 provides Web based applications to clients 108 , 110 , and 112 . Clients 108 , 110 , and 112 are clients to server 104 . Distributed data processing system 100 may include additional servers, clients, and other devices not shown. In the depicted example, distributed data processing system 100 is the Internet with network 102 representing a worldwide collection of networks and gateways that use the TCP/IP suite of protocols to communicate with one another. Distributed data processing system 100 may also be implemented as a number of different types of networks, such as, an intranet, a local area network (LAN), or a wide area network (WAN).
Referring to FIG. 2 , a block diagram depicts a data processing system, which may be implemented as a server, such as server 104 in FIG. 1 in accordance with the present invention. Data processing system 200 may be a symmetric multiprocessor (SMP) system including a plurality of processors such as first processor 202 and second processor 204 connected to system bus 206 . Alternatively, a single processor system may be employed. Also connected to system bus 206 is memory controller/cache 208 , which provides an interface to local memory 209 . I/O bus bridge 210 is connected to system bus 206 and provides an interface to I/O bus 212 . Memory controller/cache 208 and I/O bus bridge 210 may be integrated as depicted. Peripheral component interconnect (PCI) bus bridge 214 connected to I/O bus 212 provides an interface to first PCI local bus 216 . Modem 218 may be connected to first PCI local bus 216 . Typical PCI bus implementations will support four PCI expansion slots or add-in connectors. Communications links to clients 108 , 110 and 112 in FIG. 1 may be provided through modem 218 and network adapter 220 connected to first PCI local bus 216 through add-in boards. Additional PCI bus bridges such as second PCI bus bridge 222 and third PCI bus bridge 224 provide interfaces for additional PCI local buses such as second PCI local bus 226 and third PCI local bus 228 , from which additional modems or network adapters may be supported. In this manner, data processing system 200 allows connections to multiple network computers. A memory-mapped graphics adapter 230 and hard disk 232 may also be connected to I/O bus 212 as depicted, either directly or indirectly. Those of ordinary skill in the art will appreciate that the hardware depicted in FIG. 2 may vary. For example, other peripheral devices, such as an optical disk drive and the like also may be used in addition or in place of the hardware depicted. The depicted example is not meant to imply architectural limitations with respect to the present invention. The data processing system depicted in FIG. 2 may be, for example, an IBM RISC/System 6000 system, a product of International Business Machines Corporation in Armonk, N.Y., running the Advanced Interactive Executive (AIX) operating system.
With reference now to FIG. 3 , a block diagram illustrates a data processing system in which the invention may be implemented. Data processing system 300 is an example of either a stand-alone computer, if not connected to distributed data processing system 100 , or a client computer, if connected to distributed data processing system 100 . Data processing system 300 employs a peripheral component interconnect (PCI) local bus architecture. Although the depicted example employs a PCI bus, other bus architectures such as Micro Channel and ISA may be used. Processor 302 and main memory 304 are connected to PCI local bus 306 through PCI bridge 303 . PCI bridge 303 also may include an integrated memory controller and cache memory for Processor 302 . Additional connections to PCI local bus 306 may be made through direct component interconnection or through add-in boards. In the depicted example, local area network (LAN) adapter 310 , SCSI host bus adapter 312 , and expansion bus interface 314 are connected to PCI local bus 306 by direct component connection. In contrast, audio adapter 316 , graphics adapter 318 , and audio/video adapter (A/V) 319 are connected to PCI local bus 306 by add-in boards inserted into expansion slots. Expansion bus interface 314 provides a connection for a keyboard and mouse adapter 320 , modem 322 , and additional memory 324 . SCSI host bus adapter 312 provides a connection for hard disk drive 326 , tape drive 328 , and CD-ROM 330 in the depicted example. Typical PCI local bus implementations will support three or four PCI expansion slots or add-in connectors. An operating system runs on processor 302 and is used to coordinate and provide control of various components within data processing system 300 in FIG. 3 . The operating system may be a commercially available operating system such as OS/2, which is available from International Business Machines Corporation. “OS/2” is a trademark of International Business Machines Corporation. An object oriented programming system, such as Java, may run in conjunction with the operating system and provides calls to the operating system from Java programs or applications executing on data processing system 300 . “Java” is a trademark of Sun Microsystems, Incorporated. Instructions for the operating system, the object-oriented operating system, and applications or programs may be located on storage devices, such as hard disk drive 326 , and they may be loaded into main memory 304 for execution by processor 302 .
Those of ordinary skill in the art will appreciate that the hardware in FIG. 3 may vary depending on the implementation. Other internal hardware or peripheral devices, such as flash ROM (or equivalent nonvolatile memory) or optical disk drives and the like, may be used in addition to or in place of the hardware depicted in FIG. 3 . Also, the processes of the present invention may be applied to a multiprocessor data processing system. For example, data processing system 300 , if configured as a network computer, may not include SCSI host bus adapter 312 , hard disk drive 326 , tape drive 328 , and CD-ROM 330 , as noted by the box with the dotted line in FIG. 3 denoting optional inclusion. In that case, the computer, to be properly called a client computer, must include some type of network communication interface, such as LAN adapter 310 , modem 322 , or the like. As another example, data processing system 300 may be a stand-alone system configured to be bootable without relying on some type of network communication interface, whether or not data processing system 300 comprises some type of network communication interface. As a further example, data processing system 300 may be a Personal Digital Assistant (PDA) device which is configured with ROM and/or flash ROM in order to provide non-volatile memory for storing operating system files and/or student-generated data. The depicted example in FIG. 3 and above-described examples are not meant to imply architectural limitations with respect to the present invention. It is important to note that while the present invention has been described in the context of a fully functioning data processing system, those of ordinary skill in the art will appreciate that the processes of the present invention are capable of being distributed in a form of a computer readable medium of instructions and a variety of forms and that the present invention applies equally regardless of the particular type of signal bearing media actually used to carry out the distribution. Examples of computer readable media include recordable-type media, such a floppy disc, a hard disk drive, a RAM, and CD-ROMs, and transmission-type media, such as digital and analog communications links.
FIG. 4 is a flow chart of user actions 400 at the client computer. User action process 400 begins ( 402 ) and the user selcets a source ( 410 ). Using the graphical user interface (See FIGS. 5-7 ) the user requests available tables ( 420 ). The user selects tabels ( 430 ). The user joins the selected tables ( 440 ). The user then selects columns from the joined tables ( 450 ). The user reviews the SQL statement ( 460 ). The user determines whether the SQL statement is valid ( 470 ). If the SQL statement is not valid, user goes to step 430 . If the SQL statement is valid, the user then saves the new SQL statement ( 480 ). If the user wants to configure another application, then the user goes to step 410 . If the user does not want to configure another application, then user action process 400 ends. ( 498 ).
FIG. 5A depicts the graphical user interface (GUI) 500 for implementing client program 400 . GUI 500 is provided by way of example and is not intended to limit the application of the invention to any other graphical user interface. The user has placed cursor arrow ( 502 ) onto “Problem Detail Section” 504 and upon clicking on the “Problem Detail Section” has received a display in table display 510 showing an alphabetical listing of available tables.
FIG. 5B depicts GUI 500 showing the user selection of two tables. The user has selected the “Problems” table ( 512 ) and the “People” table ( 514 ) from table display (See FIG. 5 A). Table links section ( 530 ) of (GUI 500 shows the “Problems” table selected in Table 1 window ( 532 ) and the “People” table selected in Table 2 window ( 534 ). Key 1 window ( 510 ) shows FIRST_PEOPLE_ID ( 536 ). Key 2 window ( 544 ) shows PEOPLE_ID ( 538 ). Type_of_Join window ( 560 ) shows 1:1 ( 562 ). The user has placed cursor arrow 502 onto the ADD button and clicked the ADD button. Table links display section 580 shows FIRST_PEOPLE_ID=PEOPLE_ID ( 582 ). The user may also select update button 522 or remove button 524 .
FIG. 5C depicts GUI 500 where the user has selected Problem Details Section 524 . Problem Details display area 560 shows all of the columns in the joined “People” and “Problems” tables. The user has placed cursor arrow 502 on the PEOPLE_ID Column and clicked the selection so that PEOPLE_ID 562 appears in Column Window 564 .
FIG. 5D depicts GUI 500 where the user has placed cursor 502 onto BEAN DETAIL tab 580 and clicked on BEAN DETAIL tab 580 . The SQL statement ( 586 ) generated by the program bean is shown in bean detail window ( 584 ).
FIG. 5E depicts SQL statement 592 having first common element SELECT 588 , second common element FROM 592 and third common element WHERE 590 . First information element 594 , second information element 596 and third information element 598 are supplied from the previous selections made by the user.
FIG. 6 is a flow chart of the Configuration Application at the server computer. Configuration Utility 600 starts ( 602 ). Configuration Utility 600 receives a source selection from the user ( 610 ). Configuration Utility 600 calls for the Program Bean for the selected source to be loaded ( 614 ). A determination is made as to whether the Program Bean is loaded ( 616 ). If the program bean is not loaded an error message is sent to the client ( 618 ) and Configuration Utility 600 returns to step 614 . If the Program Bean is loaded, Configuration Utility 600 connects to Back End Storage (BES) ( 620 ). A determination is made as to whether the connection to BES is made ( 622 ). If the connection to BES is not made, Configuration Application 600 returns to step 620 . If the connection to BES is made, Configuration Application 600 interrogates BES for table definitions ( 624 ). The SectionBean for the running application is loaded with table, column and join information. ( 626 ). Configuration Application 600 displays the available table of the BES for the user ( 628 ). Configuration Application 600 receives user table selections ( 630 ). The selected tables are interrogated for available columns ( 632 ). Join information is received from the user ( 634 ). Configuration Application 600 verifies valid SQL generation ( 636 ). A determination is made as to whether the user has made valid selections ( 638 ). If the user has not made valid selections, an error message is displayed ( 640 ) and Configuration Application 600 returns to step 624 . If the user has made valid selections, the SectionBean is serialized ( 642 ) and Configuration Application 600 ends ( 650 ).
With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.
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A Configuration Application running on a server that responds to a web client is disclosed. The Configuration Application has a Bean Configuration Utility, a Program Bean and one or more SectionBeans within the Program Bean. The Configuration Application has a graphical user interface for the user to select tables, join tables, select columns, review a conditional SQL statement at the graphical user interface, and save the SQL statement. Using the graphical user interface, the user at the client computer can manipulate the Program Bean to return custom fields from the database without a change to the running application itself. The Program Bean is serializable and can be saved to a file, database, or it can be sent through a network socket (TCP/IP).
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to a clock recovery system for synchronizing color graphic image display. More particularly, this invention relates to an intelligent and independent analog signal interface controller provided with self-alignment to analogy signals and intelligent and dynamic phase tracking for continuous periodical clock recovery.
2. Description of the Prior Art
Several technical difficulties are faced by those who apply state of art technology in providing a LCD control card to display color images on a liquid crystal display (LCD) panel. These technical difficulties are caused by many uncharacterized factors now exist in current technology for analog-digital signal interfaces. Specifically, these uncharacterized factors are resulting from 1) the frequency f 1 of the analog signals from the graphic card is not available to the LCD control card; 2) the jitters of the phase shift between frequency f 1 of the graph card and the LCD control card f 2 , especially the long term jitters generated by phase shifts in two separate systems; 3) analog signal distortions in transmitting from the graphic card to the LCD control card; 4) HSYNC (n f 1 ) received from graphic control card is non-integral clock cycles of local clock (f 2 ) since f 2 is not exactly equal to f 1 ; 5) relative frequency shift; and 6) the uncharacterized timing relationship between a horizontal synchronization signal (HSYNC) and the analog RGB signals. These technical difficulties lead to several design and image display problems, which are not resolved by those of ordinary skill in the art.
A first problem encountered by a LCD control card designer is the difficulties in dealing with the sampling of the analog signals. Due to these uncharacterized factors, sampling of analog signals becomes very sensitive to clock phase, clock jitter, and clock accuracy. However, jitters generated by relative frequency and relative phase shifts prevent accurate sampling of the analog signals. This leads to poor display image quality and degraded performance in processing the analog signals by an LCD control card. Image distortions in space, time and gray scale are produced due to sampling errors. Uneven and blurred edges are shown on vertical lines in displaying the images. Loss of edge sharpness of the graphic images is produced. Uneven sampling from frame to frame is also a problem caused by variations of the analog RGB data received from the graphic controller. Several systems are now available in the market in attempt to resolve these problems by a method of manually make an on-screen selection (OSD). But an OSD manual adjustment cannot handle the more dynamic variations and cannot optimize the phase margins due to the limitations that human eyes cannot identify 180 phase of the RGB signals. The phase margin selected by the OSD method cannot assure sufficient margins are provided to cover different conditions that may cause the frequency and phase to shift.
In an A/D converter provided by Genlock, for video application, the incoming video stream signals are tracked to detect the SYNC signals. As the SYNC signals are in synchronization with the phase of the incoming video signals, the detected SYNC signals are employed to generate a new clock phase to line-up with the video signal phase. Since the SYNC signals must be generated separately, standard output signals provided by regular CRT graphic cards cannot be included in by a LCD control card implemented with Genlock converter.
In a system provided by Read/Write Channel, the digital data are coded. Transitions of digital data can be easily detected. A pulse can be generated in alignment with a transition of digital data. The pulse can be employed as a reference phase for aligning the clock phase. The frequency is then determined by applying the elapsed time between the pulses generated according to the digital data transitions. Again, as that incurred in Genlock system, the coded digital data must be generated separately, standard output signals provided by regular CRT graphic cards cannot be employed directly by an LCD control card implemented with Read/Write clock recovery system.
Therefore, a need still exists in the art of digital flat-panel image display to provide a clock recovery system and method to resolve the problems discussed above. Specifically, it is desirable to provide a novel method and an intelligent clock recovery system to achieve self-alignment between the clock and the RGB image data. It is further desirable that the self-alignment with the RGB data can be achieved by employing a standard RGB DIN connector used for conventional CRT display. Connectors for regular CRT can be directly employed for connecting to a LCD graphic control card for a digital LCD monitor without requiring a separate signal processor and data transceiver as that required in Genlock and Read/Write Channel such that simple and low cost implementation can be achieved.
SUMMARY OF THE PRESENT INVENTION
It is therefore an object of the present invention to provide a new clock recovery system without relying on clock signals provided from a RAMDAC card. Therefore, the aforementioned difficulties and limitations caused by uncharacterized parameters in the prior art can be overcome.
Specifically, it is an object of the present invention to provide a new configuration and method for a clock recovery system where the phase and frequency are determined by employing the real time image data. The uncertainties and distortions caused by phase and frequency drifts and deviations caused by random phase, jitters over a period of time between real-time analog data and local generated clock for A/D converter are eliminated.
Another object of the present invention is to provide a new clock-recovery system implemented with novel configuration and method where an automatic phase alignment to the incoming RGB signals and HSYNC are performed dynamically and automatically. The technical difficulties leading to poor quality of video images caused by the uncharacterized parameters as discussed above are therefore eliminated.
Another object of the present invention is to provide new clock-recovery system implemented with novel configuration and method where an automatic phase alignment to the incoming RGB signals and HSYNC is performed at 180Υ of the RGB signals to allow more phase variations due to inaccurate frequency from the RAMDAC clock Greater tolerances for RAMDAC frequency inaccuracies are provided without causing additional deviations of phase alignment within the greater tolerance limits.
Another object of the present invention is to provide a new clock-recovery system implemented with novel configuration and method where an automatic phase alignment to the incoming RGB signals and HSYNC are performed dynamically and automatically. Conventional on-screen-selection (OSD) to align the phase by a manual tuning is no longer necessary and can be provided only as an option. The manual phase tuning can be provided to override the automatically phase alignment according to a user's preference if an OSD option is selected.
Briefly, in a preferred embodiment, the present invention discloses a clock recovery system for aligning a clock-phase with RGB signals. The clock recovery system includes a voltage transition detector for detecting consecutive voltage transitions from receiving the RGB signals. The clock recovery system further includes a phase-selection means for applying the times detected for the voltage transitions for latching the clock-phase of the A/D converter to a phase angle of the RGB signals. In a preferred embodiment, the clock-phase of the A/D converter is latched to a half-cycle phase, i.e., 180Υ phase-angle, according to the detected times of the voltage transitions from receiving the RGB signals. The time recovery system further includes a RGB analog signal sensor tracking with an preamplifier of an A/D converter. It further includes a digital phase lock loop (PLL) for carrying out a dynamic RGB phase-segment selection update for adjusting the A/D clock by making a left-or-right phase-shift operation to dynamically and continuously correct random phase jitters.
In a specific embodiment, this invention discloses a clock recovery system for aligning a clock-phase with RGB signals. The clock recovery system includes a frequency-synthesizing loop for receiving a reference clock signal (CKREF) to generate a synthesized frequency. The clock recovery system further includes a fine-tuned frequency synthesizing loop for receiving a horizontal synchronization signal (HSYNC) to fine tune the synthesized frequency into a fine-tuned synthesized frequency. The clock recovery system further includes a phase divider for subdividing the fine-tuned synthesized frequency into a multiple phase segments for inputting to the multiplex controller. The clock recovery system further includes a multiplex controller for receiving the multiple phase-segments subdivided. The clock recovery system further includes an analog sensor for receiving and sensing the RGB signals for generating encoded sensing data corresponding to voltage transitions of the RGB signals. The clock recovery system further includes a transition detection means for applying the encoded sensing data for generating transition-detection data. The clock recovery system further includes a threshold triggering circuit for comparing the transition-detection data with a threshold data and triggering a RGB-phase data upon detecting the threshold data is exceeded by the transition detection data. The clock recovery system further includes a phase sampling means for applying the RGB-phase data for selecting a clock-alignment phase-segment from one of the multiple phase segments received from the multiplex controller for aligning the clock-phase. The clock recovery system further includes a digital phase-lock loop (PLL) includes a phase shift-direction detector (PD) for receiving the RGB-phase data from the threshold triggering circuit and the clock-alignment phase-segment from the multiplex controller for generating a dynamic phase-shift difference. The digital PLL further includes a digital filter for receiving the dynamic phase-shift difference from the PD for generating a phase-segment-shift signal for outputting to the multiplex controller for shifting the clock-alignment phase-segment to dynamically align the clock-phase. This invention also discloses a method of processing red-green-blue (RGB) analog signals for converting said RGB analog signals to corresponding digital signals for image display. The method includes the steps of a) receiving a reference clock (CKREF) signal as a digital signal; b) generating a synthesized frequency (f 2 ) by applying a phase-locking operation for locking a phase of the synthesized frequency with the reference clock (CKREF) signal; c) receiving horizontal synchronization (HSYN) signals as digital signals and generating a fine-tuned synthesized frequency (f 2 ′) by performing a phase locking operation to lock a phase of the fine tuned synthesized frequency with the HSYN signals; d) dividing the fine-tuned synthesized frequency (f 2 ′) into N′-equal phase-segments where N′ is a positive integer; e) detecting at least two voltage transitions from receiving a series of the RGB analog signals and generating a clock-phase select signal for automatically selecting an auto-selected phase-segment among the N′-equal phase-segments for latching the fine-tuned synthesized frequency (f 2 ′); and f) periodically detecting voltage transitions from receiving a series of the RGB analog signals after a predefined elapsed-time and generating a dynamic clock-phase select signal for periodically selecting an auto-selected phase-segment among the N-equal phase-segments to for latching the fine-tuned synthesized frequency (f 2 ′). In a preferred embodiment, the method further includes a step of g) providing a static phase adjusting means to allow a user to select a user-selected phase segment among the N′-equal phase-segments to for latching the fine-tuned synthesized frequency (f 2 ′).
These and other objects and advantages of the present invention will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiment which is illustrated in the various drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a functional block diagram of a clock recovery system of this invention;
FIG. 2 is a flow chart for illustrating the functional steps performed by the clock recovery system of FIG. 1; and
FIG. 3 is a diagram for illustrating dynamic phase adjustment performed by the time recovery system of this invention to continuously monitor and periodically adjust the phase of the clock to achieve f 2 convergence.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Please refer to FIG. 1 for a functional block diagram of an improved phase alignment and clock recovery system 100 of this invention. Digital input signals of horizontal synchronization HSYN and a reference clock CKREF are first received by a multiplex controller 105 . A one-bit I 2 C bus signal is applied to the multiplex controller 105 . The horizontal synchronization signal HSYN is passed to a phase-frequency difference detector 110 when the I 2 C bus bit is one to perform a phase difference (PD) detection operation. And, the reference clock signal CKREF signal is passed to the phase-frequency difference detector when the I 2 C bus bit is zero to perform a frequency and phase difference (PFD) detection operation. The phase-frequency difference detector 110 generates a phase difference represented by Δt. The phase difference Δt generated by the phase-frequency difference detector 110 is charge-pumped by a pump circuit 115 to produce a voltage difference ΔV. The voltage difference ΔV is filtered by a loop filter 120 to eliminate the AC components of the voltage difference ΔV. The DC component of the voltage difference is inputted to a voltage controlled oscillator 125 to generate a frequency signal representing the phase-frequency discrepancy between the frequency of a synthesized frequency f 2 with the frequency reference clock signal CKREF or between f 2 and the horizontal synchronization signal HSYN. The output frequency from the voltage control oscillator VCO 125 is divided by an M-parameter received from the I 2 C bus by a dividing circuit 130 . The output generated by the dividing circuit 130 is applied as a feedback signal for inputting to the phase-frequency difference detector 110 to complete a phase-lock loop (PLL) operation. The voltage-controlled oscillator 125 therefore generates a synthesized frequency, which is subdivided into thirty-two equally divided phase-segments. The synthesized frequency, now subdivided into a plurality of segments, is provided as input to a three-way multiplex controller 135 . One of these thirty-two segments will be selected according to three selection-input received by the multiplex controller 135 , which will be further described below.
One of the selection-input signals received by the three-way multiplex controller 135 is an on-screen-selection (OSD) input signal of five bits from the I 2 C bus. If this OSD user-selection input signal is a non-zero value, then a phase segment according to this non-zero value is selected. This user selection is an overriding signal to override two other user-selection input signals generated by automatic phase alignment processes to be further described below. If this OSD user-selection input is zero then the phase segment selection input generated from the automatic phase alignment processes is applied.
The automatic phase alignment processes start from receiving the RGB signals into an analog sensor 142 A/D converter 140 where the RGB signals are amplified and then converted to a differential complimentary output functioning as coded data providing signal transition information. A transition detector 145 detects the reception of the RGB signals where the voltage transitions from receiving the RGB image signals are detected. After detecting two consecutive voltage transitions, the detected signals are transmitted to a phase sampler 150 employed to select a phase-segment among the thirty-two phase segments aligned with the phase determined from the transitions as the results of receiving the RGB signals) The phase-segment number for the selected phase-segment is then transmitted to the three-way multiplex controller 135 as a phase-sampler selection input to the three-way multiplex controller 135 . This selected phase-segment as one segment among thirty-two phase segments is then passed from the three-way multiplex controller 135 as a clock output signal (CKOUT) to a latch circuit 155 . The digital signals generated from the A/D converter 140 are latched to this selected phase segment provided by the phase sampler 150 to provide the digitized RGB signals with precisely aligned phase for display on a digital image display panel. It is to be noted that the signals generated by the clock of the A/D converter 140 is not employed for RGB sampling as that commonly implemented in a conventional graphic control card. The clock of the A/D converter may not have a correct phase according to the incoming RGB signals. The clock of the A/D converter is then latched to the half-cycle, i.e., a phase angle of 180Υ of the RGB signal cycles based on the timings detected for voltage transitions by the transition detector 145 . The methodology of sensing the voltage transitions during the reception of RGB signals and latching the clock to the phase angle from the detected transitions is not obvious for a conventional A/D converter because the A/D clock is commonly used for RGB signal sampling and holding operations.
The method of applying RGB analog signal sensing for clock recovery is not obvious for the reason that a personal computer (PC) does not provide a test bit. The “pulses” of RGB signals must be detected to carry out to determine the phase of the analog RGB signals for static phase adjustment. However since the RGB swings can be random variations including the signal variations representing the least significant bits (LSB), the most significant bits (MSB), etc., furthermore, the delay time of an analog to digital conversion can also vary when there is no clock employed. The task for detecting the RGB signals for phase determination is quite difficult. Implementation of RGB sensing as the integrated circuits (ICs) requires higher level of signal processing algorithms and more sophisticate design skills. Therefore, the clock recovery system as disclosed in this invention is not obvious to those of ordinary skill in the art.
Furthermore, a phase shift-direction detector 160 also receives the CKOUT signal and the voltage transition detected by the transition detector 145 . The phase shift-direction detector 160 compares and determines the phase deviation between the CKOUT and the phase detected by the transition detector 145 directly from the digitized of analog RGB signals generated by the RGB analog sensor 142 . The phase difference is then inputted to a digital loop filter 165 to generate a phase segment selection input signal. The phase segment selection is inputted to the three-way multiplex controller 135 as an updated CKOUT output signal. The updated CKOUT signal is provided to the latch circuit 155 . Again, the CKOUT signal is employed by the A/D converter to adjust the phase of its clock such that the image signals can be displayed with continuously updated phase alignment.
In summary, the present invention discloses a clock recovery system for aligning a clock-phase with RGB signals. The clock recovery system includes a voltage transition detector 145 for detecting consecutive voltage transitions from receiving the RGB signals. The clock recovery system further includes a phase sampler 150 , for applying the voltage transitions for aligning the clock-phase with the RGB signals. In a preferred embodiment, the clock-phase is aligned to a phase angle of 180Υ of a RGB signal cycles. In another preferred embodiment, the clock recovery system further includes a phase shift-direction detector 160 . The phase shift-direction detector 160 receives the CKOUT signal and the voltage transition detected by the transition detector 145 . The phase shift-direction detector 160 compares and determines the phase deviation between the CKOUT and the phase detected by the transition detector 145 directly from the digitized RGB signals. The clock recovery system further includes a digital digital phase lock loop (PLL) including the digital loop filter 165 , the phase shift shift-direction detector 160 and the three-way multiplex controller 135 . The phase difference detected by the phase shift-direction detector (PD) is inputted to the digital loop filter 165 to generate a phase segment selection input signal.
FIG. 2 is a flow chart for illustrating the processing steps of the clock recovery system 100 . The process begins with the reception of an eleven-bit input of (M, N, R) from the I 2 C bus (step 300 ) where M, N, and R are integer parameters. A determination is then made of a one-bit I 2 C bus input of a fine-tuning bit to evaluate if that one-bit input is zero or one (step 305 ). If the one-bit input is zero, then an input of reference clock frequency CKREF is read (step 310 ) and a phase-frequency difference (PFD) detection (step 315 ) employed to perform a frequency synthesis by applying a frequency synthesizer (step 320 ). On the other hand, if the one-bit I 2 C bus input is one, then an input of horizontal synchronization signal (HSYNC) is read (step 325 ). And, a phase difference (PD) detection is performed (step 330 ) to generate a fine tune the phase and produce a fine-tuned synthesized frequency (step 335 ) with phase aligned with the HSYNC. In carrying out the frequency synthesis applying the CKREF (step 320 ) or fine-tuning the frequency-phase to align with the HYSNC (step 335 ), the each cycle is subdivided into a plurality of phase-segments, e.g., 32 phase-segments. These thirty-two phase-segments are inputted to a three-way multiplex controller (step 340 ) where further processes are carried out by the clock recovery system 100 to select one among these thirty-two phase segments.
For selection of one of these thirty-two phase segments to align the phase of the system clock, an option is provided for a user to make an on-screen-selection (OSD) input through a five-bit I 2 Cinput. A determination is made first to evaluate if the five-bit input is a non-zero value (step 345 ). If the five-bit input is a non-zero OSD value, then the three-way multiplex controller employs the OSD non-zero value for aligning the system clock to the selected OSD phase-segment This selected OSD phase-segment becomes an overriding output value CKOUT for inputting to a latch-circuit for latching to the selected phase segment.
If there an OSD selection is not made, then the OSD value is zero and the clock recovery system 100 carries out an automatic phase alignment by checking the number of pulses generated from RGB signals (see step 360 below). Making use of the digitized RGB signals generated from an analog sensor 142 (step 350 ), the clock system recovery system performs the automatic phase alignment. A transition detector receives the digitized RGB signals to detect a signal pulse generated from the RGB signals (step 355 ). A determination is made to check number of pulses generated by the transition detector (step 360 ). When there is no pulse generated or when there is only one-pulse received from the transition detector, the process of checking the number of pulses (step 360 ) is re-iterated. When two pulses are generated from the transition detector, the times of these two pulses are inputted to a clock phase selection circuit for selecting a RGB phase. After the RGB phase is generated the clock phase selection circuit is shutdown. The selected phase is provided to the three-way multiplex controller to provide a selected phase-segment as the CKOUT for latching and aligning the RGB signals to that phase segment (step 370 ). It is to be specially noted that the phase alignment of the RGB signal is carried out at the center, i.e., at 180Υ phase angle, of the RGB signal cycle to allow greater tolerance of phase margins when there is a phase shift of the RGB signals. Phase margins are necessary because the RGB signals can be LSB, MSB, or full scale signals, error tolerance must be provided for not detecting the signal transitions representing a RGB signal cycle. Phase shifts of RGB signals often occur due to small random variations in frequency and phase accumulated over time during continuous long-time signal processing and transmission.
In addition to the automatic phase alignment by directly detecting the timing of the RGB signals, a continuous monitoring of the phase drift under various conditions under long-term operation is also carried out. The selected phase segment CKOUT and the detected RGB pulses are also inputted to a phase detector for determining the phase deviations of the CKOUT with the RGB pulses (step 375 ). The phase difference is then processed by a digital loop filter (step 380 ) to produce an updated phase segment selection for inputting to the three-way multiplex controller to shift the CKOUT signal at one left or right phase segment as a dynamically updated phase alignment signal. In addition to the phase alignment to the RGB pulses, the shift of frequency is also continuously monitored and adjusted by applying the HSYNC signals through the steps of steps 325 and 330 as described above.
The clock recovery system of this invention is provided to first generate a synthesized frequency (f 2 ) based on the CKREF signals provided from the I 2 C bus and f 2 is not equal to f 1 . The synthesized frequency is then tuned (f 2 ′) to be phase aligned with the HYSNC signal where f 2 ′ is approximately equal to f 1 . However, it is recognized that there is a phase difference between the HYSNC data and the RGB signals (f 1 ). The transitions from receiving the RGB signals are then detected and a phase signal is generated based on the transitions detected according to the transmission and reception of the RGB data. Continuous alignment of the phase and frequency of the A/D converter to the detected RGB phase signal, i.e., making Δf 2 ′ approximately equal to Δf 1 , are carried out by the clock recovery system through the left or right phase-segment shift by changing the ΔCKOOUT. The timing and frequency of video RGB signal receptions for performing the LCD image display can therefore be precisely controlled. The uncharacterized phase and frequency shifts due to random variations and deviations of signal transmission, reception, and jitters as that encountered in the prior art can therefore be eliminated.
According to FIG. 2 and above description, this invention also discloses a method of processing red-green-blue (RGB) analog signals for converting said RGB analog signals to corresponding digital signals for image display. The method includes the steps of a) receiving a reference clock (CKREF) signal as a digital signal (step 310 ); b) generating a synthesized frequency (f 2 ) by applying a phase-locking operation for locking a phase of the synthesized frequency with the reference clock (CKREF) signal (step 320 ); c) receiving horizontal synchronization (HSYN) signals as digital signals (step 325 ) and generating a fine-tuned synthesized frequency (f 2 ′) by performing a phase locking operation to lock a phase of the fine tuned synthesized frequency with the HSYN signals (step 335 ); d) dividing the fine-tuned synthesized frequency (f 2 ′) into N′-equal phase-segments where N′ is a positive integer; e) detecting at least two voltage transitions from receiving a series of the RGB analog signals (step 355 ) and generating a clock-phase select signal (step 365 ) for automatically selecting an auto-selected phase-segment among the N′-equal phase-segments for align the fine-tuned synthesized frequency (f 2 ′) to the phase-segment (step 370 ); and f) periodically detecting at least two voltage transitions from receiving a series of the RGB analog signals after a predefined elapsed-time (step 355 ) and generating a dynamic clock-phase select signal (step 380 ) for periodically selecting an auto-selected phase-segment among the N-equal phase-segments for align the fine-tuned synthesized frequency (f 2 ′) to the phase-segment (step 370 ). In a preferred embodiment, the method further includes a step of g) providing a static phase adjusting means to allow a user to latch the fine-tuned synthesized frequency (f 2 ′) to a selected phase segment among the N′-equal phase-segments.
FIG. 3 illustrates the adjustment and convergence of the clock frequency f 2 of the A/D converter to the frequency f 1 of the graphic card of a personal computer continuously sending the RGB analog signals for image display. The main curve shows the variation of the jitter amplitude Δf 1 of the frequency f 1 . In the mean time, as the frequency f 1 fluctuates and jitters, the frequency f 2 is adjusted accordingly through the process of dynamic phase alignment process performed by the digital phase lock loop (PLL). Along the time line represented by the X-axis, there are thousands of f 1 clock cycles and an RGB signal is transmitted in each clock cycle. In some periods of time, e.g., busy periods, there are great number of RGB signals transmitted while in other periods of time, e.g., quite periods, there are only few RGB signals being transmitted. There is tendency that faster convergence of frequency f 2 to frequency f 1 is achievable because more data are available. Through several frames of RGB transmissions, e.g., n frames, the frequency f 2 is gradually adjusted and converged to the frequency f 1 .
Therefore, this invention provides a new clock recovery system without relying on clock signals provided from a RAMDAC card such that difficulties and limitations caused by uncharacterized parameters in the prior art are resolved. Specifically, the present invention provides a new configuration and method for a clock recovery system where the phase and frequency are determined by employing the real time image data. The uncertainties and distortions caused by phase and frequency drifts and deviations caused by phase-difference between real-time analog data and local generated clock for A/D converter are eliminated. An automatic phase alignment to the incoming RGB signals are performed dynamically and automatically. The technical difficulties leading to poor quality of video images caused by the uncharacterized parameters are therefore eliminated. The automatic phase alignment to the incoming RGB signals and HSYNC is performed at 180-degree to allow more phase variation due to inaccurate frequency from the RAMDAC clock and the variations of RGB signals provided by different types of A/D converters . Greater tolerances for RAMDAC frequency inaccuracies are provided without causing additional deviations of phase alignment within the greater tolerance limits. Furthermore, the automatic phase alignment to the incoming RGB signals and HSYNC are continuously performed dynamically and automatically. Conventional on-screen-selection (OSD) to align the phase by a manual tuning is no longer necessary and can be provided only as an option. The manual phase tuning can be provided to override the automatically phase alignment according to a user's preference if an OSD option is selected.
Although the present invention has been described in terms of the presently preferred embodiment, it is to be understood that such disclosure is not to be interpreted as limiting. Various alternations and integrated circuit (IC) implementations for each functional block and modifications will no doubt become apparent to those skilled in the art after reading the above disclosure. Accordingly, it is intended that the appended claims be interpreted as covering all alternations, modifications and algorithms and circuit implementations as fall within the true spirit and scope of the invention.
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A clock-recovery system is used to align a clock-phase with the RGB-signals. A frequency-synthesizing loop is applied for receiving a reference clock signal (CKREF) to generate a synthesized frequency. A fine-tuned frequency-synthesizing loop then receives a horizontal synchronization signal (HSYNC) to fine-tune the synthesized frequency into a fine-tuned synthesized frequency. A phase divider subdivides the fine-tuned synthesized frequency into a multiple phase segments for inputting to a multiplex controller. An analog sensor, receives and senses the RGB signals for generating encoded sensing data corresponding to voltage transitions of the RGB signals. A transition detector then applies the encoded sensing data for generating transition-detection data. A threshold triggering circuit compares the transition-detection data with a threshold data and triggering a RGB-phase data upon detecting the threshold data is exceeded by the transition detection data. A phase sampling detector applies the RGB-phase data for selecting a clock-alignment phase-segment from one of the multiple phase segments received from the multiplex controller for aligning the clock-phase. A digital phase-lock loop (PLL) includes a phase shift-direction detector (PD) receives the RGB-phase data from the threshold triggering circuit and the clock-alignment phase-segment from the multiplex controller for generating a dynamic phase-shift difference. The digital PLL further includes a digital filter to receive the dynamic phase-shift difference from the PD for generating a phase-segment-shift signal for outputting to the multiplex controller for shifting the clock-alignment phase-segment to dynamically align the clock-phase.
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FIELD OF THE INVENTION
The present invention relates to improving the quality of extruded annular products, particularly products produced by plastic resin extrusion lines and most particularly blown plastic film.
BACKGROUND OF THE INVENTION
In making such cylindrical products, the material from which the product is formed is extruded from an annular extrusion die and pulled along the die axis. In the case of blown film, plastic resin is extruded from a heated extruder having an annular die and the molten polymer is pulled away along the die axis in the form of an expanded bubble. After the resin cools to a set diameter as a result of application of cooling air, the bubble is collapsed and passes into nip rolls for further manufacturing steps.
As the film is extruded, thickness variations occur about the circumference of the bubble. The presence of thickness variations creates problems for downstream conversion equipment such as printing presses, laminators, or bag machines. In processes where the film is not converted in-line, but is wound onto a roll prior to converting, the thicker and thinner areas of many layers on the roll create hills and valleys on the roll surface which deform the film and magnify the subsequent converting problems especially with larger diameter rolls. It is therefore desirable to minimize such thickness variations, not only in blown film but in other extruded cylindrical products as well. To achieve this goal, processors use expensive equipment designed to randomize the position of these thick and thin areas over time or to automatically reduce the magnitude of these variations so that the finished roll is suitable for later converting steps.
It is recognized that thickness variations are caused by a variety of factors such as circumferential nonuniformity in flow distribution channels (ports and spirals) within the die, melt viscosity nonuniformity, and inconsistent annular die gaps through which the polymer exits the die. Flow distribution problems inside the die are of particular concern because they typically take the form of relatively sharp, closely spaced high and low spots which are commonly referred to as “port lines”. Additionally, variability of the cooling air and non-uniformity of air aspirated into the cooling air stream from the atmosphere surrounding the extrusion line are major contributors to film thickness variation. Many film processors rely on conventional blown film equipment to determine the film thickness. This approach typically yields an average variation of +/− 10 to 20% in film thickness overall, with the largest contributor typically being that of port lines.
It is desired to make improvements in the die to obtain higher quality film and other products so that the downstream equipment can be run faster and longer and so that the end use products will have more consistent thickness.
One major difficulty to overcome in designing a die is how to uniformly convert a typically non-uniform flow of molten polymer or other material that is conveyed to the die via a “melt” pipe into a relatively thin annular flow. Annular flow implies that there is an inner and outer forming wall as opposed to just an outer enclosing wall such as exists with the melt pipe. To introduce this inner forming wall into the molten stream requires that this new inner forming wall be rigidly fixed within the cavity of the outer enclosing wall of the die. To do this, connecting structures must be placed within the flow path of the molten material that temporarily disrupt the flow forming multiple, separate flows which then pass by the connecting structures and must be recombined in some way. Unfortunately, molten polymer exhibits non-uniform melt viscosity due mainly to variations in molecular level properties as well as local polymer temperature. These viscosity effects are collectively referred to as the rheology. One such property of major concern is that polymers exhibit “non-Newtonian” flow behavior. This means that the viscosity of the polymer changes depending on how fast it is moving through a given channel. The net effect when all viscosity effects are combined is that the polymer tends to segregate by viscosity making uniform recombination of multiple polymer flows very difficult. Additionally, molten polymer remembers its previous flow history and instead of seamlessly recombining, the multiple polymer flows tend to form unwanted “weld lines” where adjacent flows are recombined. The problem of weld lines intensifies when degradation of the polymer occurs due to low polymer flow rates.
Several approaches are presently employed to provide for connecting structure between the outer and inner forming walls of the die. One approach feeds from the centerline axis, a small distribution chamber in the die. This chamber separates and directs the polymer into several smaller, equally spaced pipes called ports, which diverge radially at some angle to the flow axis of the incoming melt. These ports convey the polymer out to a diameter appropriate for recombining into the annular flow which will exit the die. Another approach creates a mushroom shaped distribution chamber out of which relatively small, highly streamlined, spider-like connecting structures diverge radially at an angle to the flow axis that allow for quick recombination before forming the generally axial annular flow that exits the die. Yet another approach feeds the die radially from the side of the die and divides the flow one or more times through a network of flow channels similar to the branches of a tree which ultimately convey the separate polymer streams to a diameter appropriate for recombining into the annular flow which will exit the die. Generally, one or more of the methods of flow separation must be employed in a blown film die, but each causes problems with segregation and potential for weld lines to form. Special recombination techniques must be employed to limit these effects.
Several techniques are used to recombine individual molten material flows into the annular flow that exits from the die. Some are designed to overlap the separate flows creating an onion-like layering effect while others simply butt opposed flows up against each other and allow time, temperature and pressure to force recombination to occur.
In blown film production, the most common recombination technique commercially available employs channels which spiral around the axis of the die. These so-called spirals, overlap one another and allow molten polymer to gradually bleed out of the channel over a “land”, eventually to flow toward the annular exit of the die forming a layered, almost onion-like recombination flow. This annular flow of polymer exits the die at what is commonly referred to as the die lip. The major problem with this approach is that the flow channels and lands must be made non-uniform to compensate for Non-Newtonian flow and other non-uniformities exhibited by the polymer. Unfortunately, major differences exist in the flow characteristics of various polymer materials that are processed. For a given die design, it may be possible to obtain even distribution around the flow annulus for one material, however, it will not be even for others. Instead, other materials tend to form somewhat sinusoidal high and low flow spots in locations which depend on the material properties being processed. Thus the spiral design approach is limited in its capability to process a broad range of materials while simultaneously holding thickness variations to a consistent, predictable minimum.
A further problem is that the polymer or other material must necessarily take a long period of time to flow through the passages, i.e., a high residence time, which can lead to degradation of the material. Additionally, as the material flows through each passage, significant backpressure is created.
In “pancake” designs which incorporate distribution channels and the spirals substantially into the face of a plate that is coaxial with the flow axis of the die, the wetted surface area is quite large so that, when combined with higher pressures, resulting separation forces between adjacent plates can grow to be so large that the die cannot be held together. This forces the designer of such dies to limit the pressure magnitude which tends to degrade even distribution. Further, in many cases, lower pressure is attained by enlarging the flow passages; however this leads to higher residence time causing degradation of polymer properties. In practice, pressure and distribution effectiveness must be balanced which can lead to limitations on how large the die can be.
A less commonly used recombination approach does not overlap the flows but instead joins them at one or more discrete locations. In these locations where two opposed flows join together, the flow is very low causing the material to have very long residence times which degrades the polymer. This degraded polymer forms a distinct weld line that exhibits poor optical properties and reduced strength which have tended to limit the use of these designs. On the other hand, since there is no overlap, the flow channels are shorter than in overlap designs. This provides benefits in lower pressure and residence time which limits degradation and allows for larger designs. Non-overlapping designs also benefit from the clearly defined flow paths which force the polymer through the same geometry regardless of melt flow characteristics as opposed to the shifting around of the flow path associated with overlapping designs. This simplifies the die design process since non-Newtonian flow is well understood through defined geometries. Unfortunately, non-uniformities in distribution still occur as the melt flow characteristics change from those that were used to design the die. As a wider range of polymer choices are made available, this becomes more of a problem.
Processors are presented with a growing number of choices of extrusion materials, each with their own special properties. For example, some polymers resist water vapor, others resist oxygen penetration, still others provide high strength or resist puncture. Increasingly, processors are finding innovative uses for these materials, oftentimes finding it desirable to combine different polymers together in a layered or “coextruded” structure to yield property benefits in several areas. To do this, dies are designed with multiple entry points which distribute the polymer flow into separate annular flows and subsequently layer these flows one inside the other while still inside the die. Although non-overlapping designs have been used, most prevalent are overlapping designs either in a concentric or pancake configuration. Pancake designs are better suited to larger number of layers because the individual layers can be stacked one on top of each other. Concentric designs are limited to about 5 to 7 layers simply because the die grows so large in diameter as to become impracticable.
It has long been recognized that having multiple layers can provide a secondary benefit in that thickness variations present in each layer can somewhat offset one another. This has a drawback; since each layer's variation depends on associated melt flow properties, throughput rate, temperature etc., the variations typically will not always average out. In fact, they can even align one on top of each other yielding no thickness averaging whatever. This is especially true of overlapping designs since the melt variations shift significantly in position and magnitude with even subtle changes in a given layer. Commercial coextrusion dies are designed with adjacent layer spirals that typically wrap in opposed directions in an effort to capitalize on this averaging effect. In the case of concentric die designs, the spirals for each layer are necessarily different in design because they do not spiral around at the same distance from the flow axis of the die. Pancake designs can be designed with the same mechanical geometry, however the path length to the die lip is necessarily different for each layer because they are stacked one on top of each other. This causes differences in the flow behavior since each layer operates at a different pressure. It has been observed that commercially available dies designed to capitalize on averaging effects exhibit both very good and very bad variation in total thickness as the throughput rate is raised through its full operating range. This occurs as resultant layer variations first oppose (good) then align (bad) with one another. An additional problem with these designs is that even if thickness variations are opposed, yielding good overall variation, the individual layer distribution can still be bad. This has a negative effect, especially when each layer is designed to take advantage of different film properties—the layers responsible for providing a barrier to oxygen and separately to water vapor can individually be highly variable even though the total thickness is uniform. It is highly desirable to achieve uniform distribution for each individual layer as well as for the combination of multiple layers.
SUMMARY OF THE INVENTION
The present invention features a regular division (RD) die which provides uniform distribution of molten extrusion material to each individual layer and exhibits a high degree of insensitivity to melt flow properties and a pressure resistive distribution system that does not limit the size of the die. This die design has particular application to the extrusion of polymeric blown film, but also applies to other forms of extrusion requiring an annular die. Blown film extrusion lines typically include a heated extruder for melting and pressurizing a flow of molten plastic resin, an annular die through which the molten resin extrudes and from which it is pulled away along an axis in the form of an expanding bubble, and an air cooling device constructed to direct cooling air into cooling contact with the bubble, to flow along the bubble and cause the molten resin to cool as the film expands until a substantially fixed maximum bubble diameter is achieved at a frost line spaced from the annular die.
The RD design may be included as an integral part of one or more individual die layers within the complete die. According to one preferred embodiment, the RD design is integrated separately in each layer of a pancake style stackable die. Each layer includes a series of concentric rings one inside of the other that performs the functions of feeding, distribution, and recombination. These rings surround and contact one another to allow the polymer to pass between them unimpeded through passages cut into the surfaces of and/or through them. The rings are bolted together forming a single unitized layer that is stacked face to face with the other layers of the complete die, each layer with its central geometrical axis being coaxial with the flow axis of the die. Polymer is separately fed into the outside diameter of the outer feed ring of each layer, the polymer passing straight radially through the feed ring wall to the radially interior associated distribution ring. For purposes of the ensuing discussion, the location of the input through the feed ring is at location 0°.
The distribution ring has flow channels machined into its radially outwardly-facing surface which act to divide the flow one or more times. Cutting the channels into the outside surface (or alternatively, the radially inwardly-facing surface or both) eliminates the detrimental effects of separation forces caused by polymer pressure; the forces produced by the polymer act against the surrounding feed ring instead of on the bolts which hold the layer(s) together.
In the distribution ring, the polymer flow input from the feed ring is divided into an even number (2 n ) of separate and equal flows. In the preferred embodiment, the input flow is divided into eight (2 3 ) flows, in three stages. The first division of flow occurs at 0°, at which point the polymer flow is divided in two and each half is directed into one of two channels, each of which wraps 90 degrees around the circumference of the ring, one clockwise from 0 degrees to 90 degrees and the other counter-clockwise from 0 degrees to 270 degrees. At the 90 and 270 degree points, each flow (half of the original) turns and travels axially for a short distance prior to being divided a second time. The second divisions occur separately at the 90° and 270° points; at each of which the flow is again divided in half and the resulting portion of the flow (one quarter of the total input flow) directed into one of a pair of channels which wrap 45° in opposite directions from, respectively, the 90° and 270° points, around the outside of the ring. These four flows end up at, 45°, 135°, 225° and 315°; at which points the flow is divided again, this time into opposite wrap angles of 22.5. The end result of these three divisions is eight separate flows which end at 45 degree intervals at, respectively, at 22.5°, 67.5°, 112.5°, . . . , 337.5. It will be noted that, after each division, equal opposite wrap angles ensure that there is equal path length and thus equal pressure drop for any path through which the polymer might flow.
Each of these eight divided flows then passes radially inwardly through the first distribution ring, either directly to the recombination rings or, if further division is desired, to a second distribution ring. It will be recognized that, by using more than one distribution ring, a larger number “n” of divisions can be accomplished without pressure penalties. In any event, after the desired number of divisions are made in the distribution rings, the resulting flows are conveyed radially inwardly to the recombination rings through a divider plate that forms an integral part of the final (e.g., the most radially inward) distribution ring.
The divider plate is relatively thin (measured axially of the die) compared to the main body of the distribution ring of which it is a part. The divider plate extends inwardly from the portion of the final radially inward distribution ring that forms the 2 n polymer flows and tapers to a thin edge at its inner circumference. Within the divider plate, and generally prior to the taper, the 2radial flows are alternately diverted to one side of the plate or the other. This provides two separate but identical flow patterns, each of which includes 2( n−1 ) recombination flows, issuing from ports located in either the upper or the lower face of the divider plate. These flows in turn are fed to a pair of recombination plates that abut the upper and lower faces of the divider plate.
One recombination plate is mounted on either side of the tapered portion of the divider plate. The recombination flow ports on one side of the divider plate are offset in such a way as to be centered between ports on the opposite side of the divider plate. This allows for precise, mirror image recombination to take place, “split” on opposite sides of the divider plate. These split, mirror-imaged flows join together at the inner edge of the divider plate. The recombination flow channels on each side of the divider plate are designed to create a flow distribution that, when added to its mirror image, results in a flat flow profile.
Insensitivity to melt rheology is attained by forcing the recombination plate flow to distribute in a non-overlapping manner, thus yielding predictable, non-shifting resultant polymer flow. Weld lines are avoided by placing an interceding land area directly in front of each port with the main flow channel passing on a diameter behind the land. Thus some of the flow from each port passes over the land and, of what remains, half flows down the channel one way and the other half flows in the opposite direction. Eventually the channel flow from one port meets opposite direction flow from the adjacent port. At this point, the main flow channel passes radially inward between the ends of adjacent lands. This creates a weld area, but because the weld area is in a high flow region the problem of polymer degradation is substantially eliminated. The main flow channel then splits again and passes on a diameter in front of each of the associated lands such that half flows down the channel one way and the other half goes the opposite direction. Thus the flow which originally was diverted around the land via the main flow channels is recombined with the land flow in a way which is predictably stable but yields a layered effect, similar to that produced in a spiral design but without shifts in position. The now annular and radially inwardly directed recombination flow passes over a final land to the tip of the divider plate where its mirror imaged split flow from the opposite side of the divider plate is added. The final channel and land are cut in such a way as to insure a smaller flow where the high flow weld line occurs and a larger flow centered on the interceding land. Upon addition of its mirror image, the deleterious effects of the weld area is minimized by the addition of the mirror images larger (non-weld) flow area.
The shape of the flow issuing from the recombination area on each side of the divider plate prior to the flows being recombined is important to achieving a combined uniform flow from opposite sides of the divider plate. Although for a given material, the individual flows from each half may also be uniform, they do not necessarily have to be. Rather, there is a wide diversity of curves which can be programmed into the design of the flow channels which after addition yield a uniformly flat combined profile. The mathematical study of “regular divisions of the plane” such as used in the study of crystallography or as can be found in graphical representations by M. C. Escher depict many suitable examples of both simple and complex profiles. A preferred profile for each split flow, is a straight line “triangle” profile which linearly increases from a minimum flow at the high flow weld to a maximum in line with the port. This profile repeats itself without discontinuity around the diameter of the layer. A second preferred split flow profile is a “sinusoidal” profile which also has its minimum at the high flow weld and maximum in line with the port.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side view showing a blown film extrusion apparatus which includes a multi-layer regular division die according to the present invention.
FIG. 2 is a schematic cross section (taken at A—A of FIG. 3) side view on an enlarged scale of the blown film extrusion regular division die of FIG. 1 .
FIG. 3 is a plan view of the general arrangement for a typical multi-layer blown film extrusion die.
FIG. 4 is a partial cross sectional side view (taken at B—B of FIG. 4 a ) of one layer for the regular division die showing the general locations of the feed inlet, dividing channels, recombination ports and channels.
FIG. 4 a is a plan view of one layer of the regular division die of FIG. 1, showing the general locations of the feed inlet, dividing channels, recombination ports and channels.
FIG. 4 b is a schematic illustration, centered on the bore of the feed inlet of one layer of the regular division die of FIG. 1, showing the general locations of the feed inlet, dividing channels, recombination ports and channels on the exterior surface of the layer, as viewed looking radially inwardly.
FIG. 5 is a schematic illustration of an upper recombination channel and associated land area, as viewed looking upwardly from the upper surface of the tapered portion of the distribution plate.
FIG. 5 a is a schematic illustration of a lower recombination channel and land area as positioned relative to FIG. 5, viewed looking downwardly from the lower surface of the tapered portion of the divider plate.
FIGS. 6 and 6 a are schematics cross sections of typically desirable flow proportions from upper and lower recombination rings.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a blown film extrusion system in which molten plastic resin is extruded to form blown film. Except for the die 10 , the system of FIG. 1 and its operation are generally conventional. In general, plastic pellets are fed into a feed hopper 2 a and are transferred into an extruder 4 a where they are melted, mixed and pressurized by the action of an extruder screw. The melt exits extruder 4 a and is conveyed through melt pipe 6 a where it is directed into blown film die 10 . Die 10 is designed to form the melt into an annular, cylindrical plastic melt flow 14 which is then extruded from an annular orifice die lip 16 at the top of die 10 . This annular melt flow is continually drawn away from the annular die lip 16 in a manner generally concentric with a process centerline 18 . The annular diameter of the melt flow enlarges as it progresses from the die until it reaches frost line 20 (indicated diagrammatically by a saw-tooth line) to form a cooled, solidified plastic tubular film bubble 22 .
Primary cooling air for the process is supplied to external air ring 24 from a conventional air source (not shown). The air is applied to contact the extruding plastic melt adjacent the base portion of the bubble by air ring lips 26 . The air flows in annular air streams 28 along the outside expanding surface of the bubble. On some blown film processes, other forms of cooling are also employed. One such system (not shown) applies cooling air to the inside surface of the bubble, according to known techniques, and is commonly referred to as internal bubble cooling, or just “IBC”. The plastic melt is cooled sufficiently to solidify into tubular bubble 22 at frost line 20 .
Also according to known techniques, tubular bubble 22 is continually drawn upward through collapsing frame 150 , 150 a where it is compressed into a flat sheet of film 22 a , also known as “layflat,” as it passes through a nipping point between nip rolls 152 and 152 a . These nip rolls are driven to continually pull the film through the extrusion process. Layflat film sheet 22 a is then converted and/or wound into finished product by downstream processing equipment such as winder 156 .
FIG. 2 shows a schematic cross section side view of the blown film extrusion die 10 of the regular division type with multiple die layers 30 a , 30 b and 30 c .Die layers 30 a , 30 b and 30 c are essentially identical, and inputs 6 a , 6 b , and 6 c from input to respective die layers 30 a , 30 b , and 30 c are positioned at an angle relative to each other as indicated in FIG. 3 . Each layer converts melt feeding in from a respective melt pipe 6 a - 6 c to cylindrical plastic melt flow 14 which is conveyed toward die lip 16 around a cylindrical inner mandrel 12 . Thus, layer 30 a converts melt flow from melt pipe 6 a to melt flow 14 a , layer 30 b forms a second cylindrical plastic melt flow 14 b which is conveyed toward die lip 16 around cylindrical plastic melt flow 14 a and inner mandrel 12 , and layer 30 c forms a third cylindrical plastic melt flow 14 c which is conveyed toward die lip 16 around cylindrical plastic melt flows 14 b and 14 a , and inner mandrel 12 . The three cylindrical plastic melt flows 14 a , 14 b and 14 c layer adjacent to each other, and thus make up the total cylindrical plastic melt flow 14 which flows between inner mandrel 12 and outer mandrel 15 until it exits through annular die lip 16 . Layer 30 a is held to die base 11 by multiple bolts 34 a . Layer 30 b is stacked on top of and held to layer 30 a by multiple bolts 34 b . Layer 30 c is stacked on top of and held to layer 30 b by multiple bolts 34 c . At the top of the stack, outer mandrel 15 is stacked on top of and held to layer 30 c by a multiple bolts 34 d . O-ring seals in annular seal areas 32 , 32 a , 32 b , and 32 c prevent plastic melt from flowing outward between the respective flat, axially-facing, abutting surfaces formed by die base 11 , layers 30 a , 30 b , 30 c and mandrel lip 15 .
FIG. 3 shows a plan view of the general arrangement for a typical blown film extrusion die 10 of the regular division type with multiple layers such as 30 a , 30 b and 30 c of FIG. 2 . As shown in FIG. 3, layer 30 a is fed from extruder 4 a by melt pipe 6 a . Layer 30 b and associated extruder 4 b and melt pipe 6 b are positioned at an angle to layer 30 a and associated extruder 4 a and melt pipe 6 a . Similarly, layer 30 c and associated extruder 4 c and melt pipe 6 c are positioned at an angle to layer 30 b and associated extruder 4 b and melt pipe 6 b . This angle, e.g., about 60 degrees, is chosen to be large enough to provide clearance between adjacent extruders and melt pipes. Annular die lip 16 is formed by the outside surface of inner mandrel 12 and the inside surface of outer mandrel 15 . Multiple bolts 34 d are arranged to hold outer mandrel in place. Multiple bolts 34 b , shown on FIG. 2, are directly beneath multiple bolts 34 d . Multiple bolts 34 a and 34 c , also shown on FIG. 2, are one above each other and positioned in between stacked multiple bolts 34 b and 34 d so as not to interfere with one another. Any number of layers can be accommodated by this approach simply by stacking and bolting them in place as demonstrated in FIGS. 2 and 3.
FIG. 4 is an enlarged cross-sectional view of a portion of the die 10 of FIG. 1 that includes layer 30 a , and FIG. 4 a is a top plan view. Layer 30 a is composed of a series of concentric rings (feed ring 40 , distribution ring 42 and recombination rings 45 , 46 ) one inside of the other, that perform the functions of feeding, distribution, and then recombining the flow of molten extruded material. In the illustrated embodiment, plastic and polymer flow passes radially through feed passage 50 to the outside diameter of distribution ring 42 .
Feed ring 40 , as shown most clearly in FIGS. 4 and 4 a is annular and has a generally vertical surface to which melt pipe 6 a is attached, and a feed passage extending radially through it to a stepped inner surface that engages the outer radially directed surface of annular distribution ring 42 .
Distribution ring 42 , in turn, defines an outer radially-facing surface that forms series of annular steps 42 a , 42 b , 42 c , each of which has a generally vertical (but slightly sloped) radially-facing wall, and which in this embodiment are separated by flat, parallel (to each other and perpendicular to the axis of the die and layer) annular surfaces. The inner surface of the feed ring and the outer surface of the distribution ring are conical and form an angle of less than 30° with the axis of the die. The underside of the top, largest diameter wall portion 42 a and the underside of the middle diameter wall portion 42 b , seal against corresponding surfaces formed at the inner radial diameter of feed ring 40 . The O-rings 43 a and 43 b provide seals at the abutting surfaces, and bolts 44 (see FIG. 2) hold the distribution ring and feed ring tightly together.
At its interior side, distribution ring 42 includes an annular divider plate portion 42 d , centered on the overall height of the distribution ring but itself having a vertical height (measured along the axis of the distribution ring and die) that is not more than about 20% that of the overall distribution ring 42 . As shown most clearly in FIG. 4, in the illustrated embodiment, the top and bottom surfaces of divider plate portion 42 d are flat and parallel to each other throughout most of the radial width of the divider plate portion, but taper towards each other adjacent the divider plate portion's inner edge.
Recombination rings 45 and 46 overlie the top and bottom of divider plate portion 42 d , and are bolted together by bolts 34 a . Adjacent their radially inner edges, recombination rings extend radially inwardly of the inner radial edge of divider plate portion, are closely adajcent to each other, and terminate close to the outer surface of inner mandrel 12 .
The principal function of distribution ring 42 is to divide the single flow from feed ring 40 into a number (i.e., 2 n in the preferred embodiment 2 3 , i.e., 8) of identical flow portions. To accomplish this, a series of flow division channels 52 , 54 and 58 are machined into the outer, generally vertical radially facing surface of step 42 b . The size and/or quantity of division channels (channels 52 , 54 and 58 are shown in the illustrated embodiment) are limited only by the vertical dimension of the outside diameter of distribution ring 42 . Flow division channels 52 , 54 and 58 divide the melt from feed passage 50 of feed ring 40 into eight separate radial port flows 59 . Because most of the flow is between the radially-facing surfaces of the feed ring 40 and distribution ring 42 , it will be evident that the forces 41 a and 41 b , along the die axis, which tend to move the distribution ring 42 and feed ring 40 apart are relatively small since they act only on the projected area (from a plan view) between seals 43 a and 43 b.
The arrangement of the division channels is shown most clearly in FIG. 4 b , which is a fold out (or unwrapped) schematic illustrating the radially-outward facing surface of wall portion 42 b of division ring 42 . As shown, division channels 52 , 54 and 58 all extend circumferentially around the outward facing surface of the division ring, and lie generally perpendicular to the axis of the die. Flow from inlet feed passage 50 passes downwardly (through a short channel 51 extending parallel to the die axis and generally perpendicular to division channel 52 , into the center of division channel. Channel 52 wraps a total of 180 degrees around the exterior of distribution ring 42 , 90 degrees in opposite directions from the point at which the flow from inlet 50 is introduced into channel 52 , and separates the melt flow from inlet 50 into two oppositely directed flows. At each of the ends of channel 52 , a short vertical channel. 53 a , 53 b directs the flow in the respective half of channel 52 (axially of the die layer) into the center of a respective one of flow channels 54 a , 54 b . Division channels 54 a , 54 b each wrap a total of 90 degrees (45 degrees in each direction from the point at which flow from a channel 53 a , 53 b is directed into the respective channel 54 a , 54 b ) around the exterior of distribution ring 42 , and divides the melt flow from channels 53 a , 53 b into a total of four flows. At each end of each division channel 54 a , 54 b , each respective flow portion is again directed vertically a short distance, through a short channel 55 a , 55 b , into the center of a respective one of division channels 58 a - 58 d . Division channels 58 a - 58 d each wrap 45 degrees (22.5 degrees in opposite directions from the point at which flow from channel 55 a - 55 d is directed into the respective division channel 58 a - 58 d ) around the outside of distribution ring 42 ) and again divide the flow, this time into a total of eight equal flow portions. At each end of each of distribution channels, the respective flow portion is directed into one of eight radial channels 59 a - 59 d and 59 a ′- 59 d ′, which convey the flow portion radially through distribution ring 42 to (as shown in FIGS. 2 and 4) either the upper (in the case of channels 59 a, b, c, d ) or the lower (in the case of channels) 59 a′, b′, c′, d ′) surface of divider plate portion of the distribution ring. As shown, each radial channel 59 a - 59 d and 59 a ′- 59 d ′, extends radially inwardly from a respective one of division channels 58 a - 58 d to the respective surface of divider plate portion 42 d , at a point just radially outwardly of the tapered portion of the divider plate portion. The polymer melt flow from division channels 58 a - 58 d is equally split to the top and bottom of the divider plate portion; half goes to upper ports 56 a , 56 b , 56 c and 56 d and the other half to lower ports 57 a , 57 b , 57 c and 57 d.
It will be noted that all of flow passages 50 , 52 , 54 a - 54 b , 58 a - 58 d , 59 a - 59 d and 59 a ′- 59 d ′ of distribution plate 42 are symmetrical such that the path length that melt must travel to reach each port is equal, ensuring even distribution.
At recombination ring 46 upper ports 56 a , 56 b , 56 c and 56 d on the upper side of divider plate 42 d evenly distribute their associated melt flow to four equally spaced positions between the upper side of the divider plate and upper recombination ring 46 . At ring 45 lower ports 57 a , 57 b , 57 c and 57 d evenly distribute their melt flow to four equally spaced positions between the lower side of the divider plate and lower recombination ring 45 . The positions at the upper side of the divider plate are midway between those positions at the lower side of the divider plate.
As most clearly shown in FIGS. 4 and 5, a pair of radially-spaced circular channels 60 , 64 are cut into the lower surface of recombination plate 46 and a similar pair of radially spaced circular channels 70 , 74 are cut into the upper surface of recombination plate 45 . A plurality of arcuate recombination lands 62 a - 62 d are provided in the lower surface of recombination plate 46 between channels 60 , 64 , and a similar plurality of arcuate recombination lands 72 a - 72 d ( 72 b and 72 c are not shown) are provided in the tipper surface of recombination plate 45 between channels 70 , 74 . Final lands 66 , 76 are provided in, respectively, the lower surface of recombination plate 46 between channel 64 and the inner radial edge of divider plate of distribution ring 42 , and the upper surface of recombination plate 45 between channel 74 and the inner radial edge of the divider plate. In this embodiment each arcuate land subtends an area of slightly less than 90°.
In general, melt flows from radial channels 59 a - 59 d and 59 a ′ 59 d ′ either into channel 60 through ports 56 a - 56 d or into channel 70 through ports 57 a - 57 d . From the outer channels 60 , 70 of the recombination rings, the melt flows inwardly, over respective recombination lands 62 a - 62 d , 72 a - 72 d or through recombination channels 61 a - 61 d , 71 a - 71 d ( 61 c , 61 d , 71 b , 71 c , and 71 d are not shown) between adjacent ends of portions of the lands, to inner recombination channels 64 , 74 . The upper melt then flows out of inner recombination channel 64 between final land 66 and divider plate 42 d ; while the lower melt flows out of inner recombination channel 74 between final land 76 and divider plate 42 d . Recombination seals 47 and 49 prevent melt from leaking outward from outer recombination channels 60 and 70 respectively. The upper and lower melt flows join at the inner tip of divider plate 42 d forming combined flow 68 that is conveyed inward to the outside wall of inner mandrel 12 where it forms cylindrical plastic melt flow 14 a.
In the illustrated embodiment, the recombination channels, recombination lands, and final land are cut into the surfaces of recombination rings 45 , 46 and the facing upper and lower surfaces of divider plate 42 d of distribution ring 42 are generally flat. In other embodiments some or all of these may be cut into the divider plate.
The arrangement of the recombination channels and lands at the lower surface on upper recombination ring 46 is shown most clearly in FIG. 5, which is a schematic, straightened out plan view of the recombination areas symmetrical about port 56 a , viewed from above. Flow enters outer recombination channel 60 through upper port 56 a ; as viewed in FIG. 4 a , one half flows clockwise down outer recombination channel 60 toward upper port 56 d and the other half flows counterclockwise toward upper port 56 b . As the melt flows in opposite directions down (i.e., circumferentially of the die) the channel, some of the polymer melt flows radially inwardly across recombination land 62 a to inner channel 64 . The rest of the melt flows circumferentially in channel 60 until it reaches the ends of recombination land 62 a (which is centered on port 56 a and subtends an arc of slightly less than 90 degrees), at which point it meets the similar but opposing melt flow originating from upper ports 56 d and 56 b . Here the opposing flows join or “weld”, forming high flow weld lines 80 a and 80 b respectively. These joined flows turn and flow inward through the respective radial recombination channels 61 a and 61 b at the opposite ends of land 62 a into inner recombination channel 64 .
In inner recombination channel land 64 , the melt flows both radially inwardly across final land 66 as well as in opposite circumferential directions down inner recombination channel 64 . The flow down the inner recombination channel 64 is layered on top of flow coming across recombination land 62 a , and also flows radially inwardly across final land 66 . The profile (i.e., configuration) of the flow radially inwardly of final land 66 depends largely on the design of the final land, which as discussed hereinafter may be designed with variable lengths and/or gaps to program a desired melt flow profile.
FIG. 5 a is similar to FIG. 5, except that FIG. 5 a shows the arrangement of the recombination channels and lands at the lower recombination area between the lower surface of divider plate portion and lower recombination ring 45 , viewed from above. Although the flow into the lower recombination area is from ports 57 a - 57 d , FIG. 5 a illustrates the arrangement symmetrical about upper port 56 a to the upper recombination area so that the relationship between the upper recombination area (of FIG. 5) and lower recombination area (of FIG. 5 a ) is most easily appreciated.
In the lower recombination area, flow enters outer recombination channel 70 through lower ports 57 d and 57 a (shown, and also through lower ports 57 b and 57 c although not shown in FIG. 5 a ). As in the upper recombination area, the flow from each port flows down outer recombination channel, one half of the flow from each port flowing clockwise and the other half counterclockwise. As described in connection with FIG. 5 a , part of the flow in channel 70 flows radially inwardly over one of recombination lands 72 d and 72 a , and the melt flow remaining at the ends of the lands welds together to form a high flow weld line 90 a , and flows inwardly through radial recombination channels 71 a into inner recombination channel 74 . In the inner recombination the melt flows radially inwardly across final land 76 , as well as in opposite directions down inner recombination channel 74 where it is layered under flow coming across recombination lands 72 d and 72 a . As in the upper recombination area, final land 76 is designed with variable lengths and/or gaps to program a desired melt flow profile.
It will be recognized that the recombination lands 62 a - 62 d and land channels 61 a - 61 d of the upper recombination area are offset at 45 degrees from the lands 72 a - 72 d and channels 71 a - 71 d in the lower recombination area. This arrangement places high flow weld lines from one recombination ring radially in line with ports from the opposing recombination ring.
FIGS. 6 and 6 a show two preferred melt flow profiles that exhibit regular division, i.e., the cross-sections of the flows from the upper and lower recombination areas are identical and fit together with no intervening space. High flow weld lines 80 a and 80 b (also 80 c and 80 d , not shown) occur in the low flow areas of final land 66 . High flow weld lines 90 a (also 90 b , 90 c and 90 d , not shown) occur in the low flow areas of final land 76 . When the upper and lower melt flows join at the inner tip of divider plate 42 d forming combined flow 68 , the opposite recombination rings high final land flow area is added and washes the effects of the weld lines out. By choosing the shape of the flow profiles 82 a - 82 d and 92 a - 92 d to be regularly divided, they all interlock to form a evenly distributed combined flow 68 .
The present invention has been described in connection with certain structural embodiments and it will be understood that various modifications can be made to the above-described embodiments without departing from the spirit and scope of the invention as defined in the appended claims.
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An extrusion die with a plurality of die layers stacked one upon the other in a direction generally parallel to the central axis. Each of the layers has an annular flow distribution ring having an outer generally cylindrical surface and an annular feed ring surrounding and engaging the outer surface of the distribution ring. At the engaged surfaces of the feed and distribution ring, the flow from the feed ring is divided into a number of substantially equal flow portions. Seals between adjacent engaged surfaces confine the flow to between the circumferential surfaces of the feed and distribution ring. Half of the flow portions are directed to a recombination region on one side of the distribution ring, and half are directed to a recombination region on the other side of the ring. In recombining, weld lines are formed in high flow areas to minimize the deleterious effect of polymer degredation. Subsequently, the flows on opposite sides of the distribution ring are recombined such that the weld lines from one half are first modified to exhibit lower flow and then are layered with non-weld line portions modified to exhibit higher flow from the other half. This further minimizes the negative effect of weld-line areas. Flow from the two sides are regularly divided to yield even distribution of the combined flows.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to the treatment of night sight problems like halos, coma and glare to which are exposed a percentage of patients who underwent refractive surgery or lensectomy with intra ocular lens (IOL: monofocal, multifocal, etc) implant in aphakic patients or intra ocular lens implant in phakic patients (“phakic IOL” like intra chamber lens ICL; Artisan, NuVita etc.). The treatment generally relates to the ophthalmic use of a pharmaceutical composition, in particular ophthalmic composition, containing aceclidine (3-acetoxyquinuclidine, R. Paoletti et al., 1998), at very low concentrations.
[0003] A highly preferred concentration range of aceclidine in total weight percent is from 0.002% to 0.040%, more preferably from 0.016 to 0.032% (of total weight percent of composition).
[0004] After refractive surgery to reduce ametropy (like for example myopia, astigmatism or hypermetropia), an average percentage of patients between 15.8% after PRK (Photo Refractive Keratectomy) and 33% after LASIK (Laser in Situ Keratomileusis) suffers of severe night sight problems due to light ray aberrations and diffraction (Rossetti et al, 2001). A comparable disorder is present in a percentage of patients that underwent lensectomy with intra ocular lens (IOL) implant (cataract or refractive lensectomy) (Martin L et al 1999; Schmitz S et al 2000; Pieh S et al 2001; Hwang IP et al 2001; Walkow L et al 2001) or with intra ocular lens implants in phakic patients to reduce ametropy (Maroccos R et al 2001).
[0005] Nowadays PRK and LASIK are the most important surgery techniques to reduce ametropy (Pop et al, 1999; Clinch et al, 1999; El-Maghraby et al, 1999; El Danasoury et al, 1999; Hersh et al, 1997). PRK consists in the laser ablation of the cornea stroma surface by use of Excimer Laser after epithelial cell removal. LASIK uses the same procedure of PRK after having created a corneal flap with a microkeratom. Radial keratotomy (RK) is an older procedure used to treat myopia. This procedure involves making radial incisions in the cornea with a diamond blade. The number and depth of radial incisions corresponds with the amount of desired correction.
[0006] These techniques do not treat the whole anterior corneal surface but they concentrate on a central optical zone with different diameters depending on corneal thickness and starting ametropy. For this reason, after surgery the “useful” portion of the cornea for a good sight is the most central one (O'Brart et al, 1995). Thus, the transition area between the treated and not treated zones may cause diffraction and aberration phenomena during night hours when pupil is typically midriatic (Martinez et al, 1998; Hersh et al, 2000). During daylight hours, since the pupil diameter is smaller than or equal to the treated optical zone, diffractions and aberrations are generally absent.
[0007] Comparable problems of light ray aberrations and diffraction are typically present in lensectomized patients with IOL implants of small diameter, because of difference between IOL diameter and mesopic pupillary diameter. Therefore, lensectomized patients may also have poor night sight due to the presence of halos, glare and coma as well.
[0008] Recently a new surgery technique has been developed for the treatment of high level ametropy that keeps the patient's lens. It consists in the insertion of a IOL in front of patient's lens either in the anterior or in the posterior chamber through a small incision (“phakic IOL” like ICL; Artisan, NuVita etc). This surgical technique may cause night vision problems as well.
[0009] Alteration of night sight causes difficulties in normal night activities (i.e. driving).
SUMMARY OF THE INVENTION
[0010] The present invention solves the problem of light ray diffraction and aberration during night hours. Very surprisingly we found that the administration of an ophthalmic composition containing aceclidine, in very low concentrations, may effectively reduce the pupillary diameter for a period of up to six hours. A sufficient fluid amount of an ophthalmic composition in accordance with the present invention may be instilled in order to cause pupil diameter reduction of more than 2-3 mm for a time period of four to six hours. This is an important feature of the present invention and enables the treatment of halos, coma and glare following refractive surgery (i.e. RK, PRK, LASIK). It may further provide means for holding and supporting IOL implants in phakic or aphakic patients following lensectomy or IOL refractive implants.
[0011] For decades parasympathomimetic compounds (like for example aceclidine, pilocarpine or carbachol) have been used at concentration of 2 or more percent by weight to reduce intra ocular pressure in glaucoma patients. These compounds enhance the aqueous humour outflow by contracting the ciliary muscle that makes traction on scleral spur widening the trabecular meshwork. They induce myosis stimulating iris muscles, contract the ciliary muscle causing forward movements of the lens with increasing myopia, lens thickening and decreasing depth of the anterior chamber. These compounds have however several serious side effects such as:
[0012] 1) drug dosage dependent myosis, with narrowing of peripheral isopter of the visual field;
[0013] 2) ciliary muscle contraction, which may cause headache;
[0014] 3) myopia enhancement lasting about 60-90 minutes after instillation, strictly related to the concentration;
[0015] 4) decreasing depth of the anterior chamber with possible retina breaks due to peripheral traction, dosage dependent and/or in case of patient predisposition;
[0016] 5) loss of accommodative ocular reaction of the treated eye.
[0017] For the reasons stated above, parasympathomimetic compounds (e.g. aceclidine, pilocarpine, carbachol) have not been suggested nor used in their original commercial concentration to reduce night sight problems after refractive surgery. The present invention provides now aceclidine in very low concentration for the treatment of the addressed problem. Surprisingly, it is found that such very low concentrations of aceclidine can provide fairly specifically the possibility to exploit iris sphincter muscle contractions inducing the natural nocturnal mydriasis and eliminating light ray aberrations and diffraction, namely halos, coma and glare, without the undesired side effects of the drugs as indicated above.
[0018] Aceclidine was found to be in particular useful to increase pupillary myosis and act on intra ocular pressure and ciliary body less than other compounds, reducing sight adaptation problems and retina breaks due to peripheral traction (R. Paoletti et al., 1998).
[0019] The effective dilution range is in particular from 0.016% to 0.040% of total weight percent of an ophthalmic composition. The diluted compound may be instilled in the eye typically 10-20 minutes before need and it acts for about 4-6 hours. In the above aceclidine concentration range no relevant side effects are detectable Aceclidine may also be useful in even lower concentrations such as 0.002% weight (of total weight of an ophthalmic composition). Accordingly aceclidine may typically be used from 0.002%-0.016%, preferably from 0.016-0.032%, also preferably from 0.032-0.040%. Aceclidine is typically formulated in an aqueous solution being adapted to ophthalmic administration. Accordingly, such an ophthalmic composition may also comprise tonicity enhancers, such as sodium chloride, glycerol, boric acid, sorbitol, mannitol and the like. It may also comprise a pH-adjusting agent to adjust the pH of the final ophthalmic composition to a physiological pH. Such pH-adjusting agents are typically a buffer such as a phosphate buffer, sodium acetate, boric acid, ammonium chloride, and the like. Such excipients are known in the art and may be used as appropriate.
[0020] The above ophthalmic compositions comprising aceclidine in very low concentrations were tested on patients treated with refractive surgery who reported a statistically significant improvement (sometimes also total regression) of halos, coma and glare and a good night sight improvement after instillation of the ophthalmic composition. Reported side effects are light, transitory (5-10 minutes) conjunctival hyperemia, while no headache or sight reduction are present.
[0021] Another surprising finding is the high selectivity of aceclidine as compared to other parasympathomimetic drugs. This selectivity addresses the effective reduction/prevention of halos, coma and glares in patient who had refractive surgery, as described above, wherein virtually no side effects (as described above) are detectable. Accordingly, aceclidine is strongly preferred over pilocarpine and carbachol.
BRIEF DESCRIPTION OF THE FIGURES
[0022] [0022]FIG. 1 shows the four graduated images used for the objective determination of the coma grading by the patients.
[0023] [0023]FIG. 2 shows the four graduated images used for the objective determination of the halos grading by the patients.
[0024] [0024]FIG. 3 shows the pupillary diameter variations average of a healthy people group treated with two aceclidine ophthalmic compositions at two different concentrations; the determination of the pupillary diameter has been performed after 30 minutes, 1, 2, 3, 4, 5 and 6 hours following the instillation of the I (4 IU, 0.016%) and II (8 IU, 0.032%) dilution of the aceclidine ophthalmic compositions.
DETAILED DESCRIPTION
[0025] The following clinical trail has been performed in order to demonstrate the activity of aceclidine at different concentrations on patients who underwent refractive surgery.
[0026] A double-masked randomized clinical trial with 14 patients (27 eyes) has been organized by dividing the patients in three different groups: 8 patients were treated with placebo, 10 patients were treated with a first ophthalmic composition (I dilution), 9 patients were treated with a second ophthalmic composition (II dilution).
[0027] The patients belonging to this trial had to go through an ophthalmic examination: of the haze grading and of natural and corrected visual acuity, intra ocular pressure (IOP), pupillometry in mesopic conditions with split lamp and examination of corneal maps. The anamnestic data about the surgical operation were collected: the refractive surgery technique employed (PRK/LASIK), the date of the surgical operation, data about the corrected optical zone and the ametropy kind. The night sight problems had to be stable for at least three months after the surgical operation for the patient to be included in the trial.
[0028] In order to render the clinical trial as much as possible objective and reproducible, the values of halos and coma perceived by the patients were graduated using eight images got from the web site www.surgical.com and elaborated with the Photoshop program; a value of halos and coma (on a scale from 1 to 4) was assigned to each image, as showed in FIGS. 1 and 2.
[0029] The patients had to identify the image they perceived before and during the pharmacological treatment, with follow-up examinations fixed every 15-30 days. At the end of the clinical trial the patients had to provide information about the efficacy and duration (in terms of hours) of the treatment, onset time of the effect, changes of the visual capabilities and side effects, if any.
[0030] The ophthalmic compositions were prepared according to the following procedure:
[0031] I dilution, 4 IU of aceclidine 2% were diluted in 5 mL of hyaluronic acid (0.200 g/100 mL)
[0032] II dilution, 8 IU of aceclidine 2% were diluted in 5 mL of hyaluronic acid (0.200 g/100 mL)
[0033] Placebo consisted in 5 mL of hyaluronic acid (0.200 g/100 mL).
[0034] The two ophthalmic compositions, I and II dilution, were administered firstly to a group of healthy people: one eye was treated with the I dilution composition (0.016%), the second eye with the II dilution composition (0.032%), measuring the pupillary diameter in the same light conditions at 30 minutes, 1-2-3-4-5-6 hours after the first instillation. FIG. 3 shows the behavior of the pupillary diameter. A mean reduction of the pupillary diameter of 2.5 mm is showed within the first 30 minutes following the instillation and with a trend to disappear after 5-6 hours.
[0035] The three ophthalmic compositions (I dilution, II dilution and placebo) were administered to the 14 patients belonging to the clinical trial in a blind way.
[0036] The results showed that 18 out of 19 eyes treated with diluted aceclidine ophthalmic compositions (I and II dilution) versus 2 out of 8 treated with placebo showed an improvement in night vision problems (95% vs 25%; p=0.04).
[0037] The efficacy in terms of hours has been reported to 6 hours with the onset after 15-20 minutes following the instillation. Mean improvement was 1.4 (±0.6) for coma and 1.14 (±0.4) for halos; 61% of patients reported a night vision acuity improvement.
[0038] The reported side effect is a modest and transient conjunctival hyperemia lasting for about 10-15 minutes. None reported headache, myopia enhancement or other alterations. Moreover no differences have been reported on the IOP or the pupillary kinetics during the follow-up examinations.
BIBLIOGRAPHY
[0039] 1. Paoletti R., Nicosia S., Clementi F., Fumagalli G., in Farmacologia oculare, a cura di: Filippo Drago e Nicola Orzatesi, ed. UTET, 1998.
[0040] 2. Rossetti L., Randazzo A., Fogagnolo P., Orzalesi N., Comparison of PRK vs LASIK for correction of myopia. The results of meta - analysis of published literature, ARVO 2001.
[0041] 3. Martin L. Computerized method to measure glare and contrast sensitivity in cataract patients, J. Cataract Refract. Surg. 1999 Mar; 25(3):411-5.
[0042] 4. Schmitz S, Dick H B, Krummenauer F, Schwenn O, Krist R. Contrast sensitivity and glare disability by halogen light after monofocal and multifocal lens implantation. Br. J. Ophthalmol. 2000 October; 84(10):1109-12.
[0043] 5. Pieh S, Lackner B, Hanselmayer G. Zohrer R, Sticker M, Weghaupt H, Fercher A, Skorpik C. Halo size under distance and near conditions in refractive multifocal intraocular lenses. Br. J. Ophthalmol. 2001 July;85(7):816-21.
[0044] 6. Hwang I P, Olson R J. Patient satisfaction after uneventful cataract surgery with implantation of a silicone or acrylic foldable intraocular lens. Comparative study. J. Cataract Refract. Surg. 2001 October; 27(10):1607-10.
[0045] 7. Walkow L, Klemen U M. Patient satisfaction after implantation of diffractive designed multifocal intraocular lenses in dependence on objective parameters. Graefes Arch Clin. Exp. Ophthalmol. 2001 September;239(9):683-7.
[0046] 8. Maroccos R, Vaz F, Marinho A, Guell J, Lohmann C P., Glare and halos after “phakic IOL”. Surgery for the correction of high myopia Ophthalmologe 2001 November; 98(11):1055-9.
[0047] 9. Pop M, Payette Y. Multipass versus single pass photorefractive keratectomy for high myopia using a scanning laser. J. Refract. Surg. 1999 July-August;15(4):444-50.
[0048] 10. Clinch T E, Moshirfar M, Weis J R, Ahn C S, Hutchinson C B, Jeffrey J H. Comparison of mechanical and transepithelial debridement during photorefractive keratectomy. Ophthalmology 1999 March;106(3):483-9.
[0049] 11. El-Maghraby A, Salah T, Waring GO 3rd, Klyce S, Ibrahim O. Randomized bilateral comparison of excimer laser in situ keratomileusis and photorefractive keratectomy for 2.50 to 8.00 diopters of myopia. Ophthalmology 1999 March;106(3):447-5.
[0050] 12. El Danasoury Mass., El-Maghraby A, Klyce S D, Mehrez K. Comparison of photorefractive keratectomy with excimer laser in situ keratomileusis in correcting low myopia ( from − 2.00 to − 5.50 diopters ). A randomized study. Ophthalmology 1999 February 106(2):411-20; discussion 420-1.
[0051] 13. Hersh P S, Stulting R D, Steinert R F, Waring G O 3 rd , Thompson K P, O'Connell M, Doney K, Schein O D. Result of phase III excimer laser photorefractive keratectomy for myopia. The Summit PRK Study Group. Ophthalmology 1997 October; 104(10):1535-53.
[0052] 14. O'Brart D P, Corbett M C, Lohmann C P, Kerr Muir M G, Marshall J. The effects of ablation diameter on the outcome of excimer laser photorefractive keratectomy. A prospective, randomized, double - blind study. Archives of Ophthalmology 1995 April 113(4):438-43.
[0053] 15. Martinez, Carlos E. M S, M D; Applegate, Raymond A. O D, Ph D et al. Effect of pupillary dilatation on corneal optical aberration after photorefractive keratectomy. Arch. Ophthalmology, Vol 116(8) August 1998; 1053-1062.
[0054] 16. Hersh P S, Steinert R F, Brint S F. Photorefractive keratectomy versus laser in situ keratomileusis: comparison of optical side effects. Ophthalmology 2000 May;107(5):925-33.
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After refractive surgery to reduce ametropy (i.e. myopia, astigmatism or hypermetropia) an average percentage of patients between 15.8% after PRK (Photo Refractive Keratectomy) and 33% after LASIK (Laser in situ Keratomileusis) shows a poor night sight due to the presence of halos, glare and coma. A comparable disorder is present in a percentage of patients that underwent lensectomy (cataract or refractive lensectomy) with intra ocular lens (IOL) implant and IOL implants in phakic patients to reduce ametropy. Thanks to the effect on pupillary kinetics, diluted low concentrations (from 0.002% to 0.040%) of Aceclidine were surprisingly found to effectively reduce and/or eliminate night sight problems for about 6 hours.
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BACKGROUND OF THE INVENTION
This invention relates work supporting beds for sewing machines, and more particularly, to a sewing machine bed structure which can be converted quickly to accommodate either flat or tubular shaped work pieces.
In a prior convertible bed construction for sewing machines as disclosed in U.S. Pat. No. 3,863,582, a hinged work supporting panel is provided which may selectively be lowered into a retracted position exposing a sewing machine cylinder bed for accommodation of tubular shaped articles or raised to a position providing a substantially coplanar extension of the work supporting surface of the cylinder bed for the accommodation of flat work pieces. In this patented construction, one set of cooperating elements is provided on one edge of the hinged work supporting panel and on the sewing machine bed for selectively retaining the panel in the raised position, while a separate set of cooperating elements is provided on another edge of the hinged work supporting panel and on the sewing machine bed for separating the panel from the sewing machine bed to prevent marring of the finish when the panel is lowered.
SUMMARY OF THE INVENTION
This invention has for an object the provision of a convertible bed construction for a sewing machine employing a hinged work supporting panel in which the problems of providing a latch device for retaining the panel in a selected position and that of providing cooperating cam elements to effect a separation of the parts to prevent damage to the finish is solved by the provision of one set of cooperating elements on the hinged panel and on the sewing machine. This object of the invention is attained by arranging a single latch detent along an edge of the hinged work supporting panel which extends radially from the axis of the hinge and a cooperating latch seat on the sewing machine bed so that the single set of cooperating elements provided by the latch seat and detent will influence not only the angular position of the work supporting panel but also a shift of the panel in the direction of the hinge axis to prevent marring of the finish.
DESCRIPTION OF THE DRAWINGS
The accompanying drawing illustrates a preferred form of this invention in which:
FIG. 1 is an end view of a sewing machine having the convertible bed of this invention applied thereto;
FIG. 2 is a top plan view of the convertible sewing machine bed of FIG. 1 partly in cross section and showing the work supporting panel in work supporting position,
FIG. 3 is an enlarged cross-sectional view of the locking detent taken substantially along line 3--3 of FIG. 2 and showing the work supporting panel in work supporting position,
FIG. 4 is an enlarged cross-sectional view of the locking detent taken substantially along line 3--3 of FIG. 2 but showing the work supporting panel moved slightly out of work supporting position, and
FIG. 5 is an enlarged cross-sectional view taken substantially along line 5--5 of FIG. 2 showing the work supporting panel in the extreme lowered position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the accompanying drawing, a bed portion of a sewing machine frame is indicated generally at 11. The sewing machine bed portion preferably comprises a base 12 from which a stabilizing strut 13 projects. The base 12 and stabilizing strut 13 define a plane of support for the sewing machine when it is placed on a table top cabinet or the like. Extending from the base 12 preferably parallel to the stabilizing strut 13 is a cylinder bed 14 extending in cantilever fashion above the plane of support for the sewing machines. The cantilever arrangement of the cylinder bed 14 provides for the accommodation thereon of tubular fabric pieces to be stitched. In FIG. 1 a fragment of a bracket arm portion 15 is shown rising from the bed portion 11. A needle bar 16 carrying a needle 17 is supported with the bracket arm portion and is shown in FIG. 1 in the relationship which it bears to the cylinder bed. Similarly a presser device 18 is carried by the bracket arm 15 in the position shown in FIG. 1 for holding work fabrics on the work supporting surface 19 of the cylinder bed during stitching operations thereon.
The stabilizing strut 13 of the sewing machine bed portion 11 is formed with a boss 20 and carries spaced therefrom a bearing boss 20' to support a hinge pin 21 pivotally engaging hinge bosses 22 formed on a work supporting panel 23. The hinge pin 21 defines an axis of turning movement for the work supporting panel 23 to be swung selectively into a raised position shown in solid lines in FIG. 1 in which a work supporting surface 24 occupies a position contiguous and coplanar with the work supporting surface 18 of the cylinder bed for accommodating flat shaped work pieces, or lowered to a position shown in dotted lines in FIG. 1 in which the work supporting panel 23 occupies a position in spaced relation to the cylinder bed and in which manipulation of tubular shaped fabric articles on the cylinder bed will not be impeded.
As shown in FIG. 2, the hinged work supporting panel 23 is preferably formed with a shape which is complemental to that of the sewing machine bed portion base 12 and cylinder bed 14 considered in plan view so that when the work supporting panel is raised it will occupy a position contiguous to these sewing machine bed portions thus to provide a continuous substantially flat work supporting surface. To this end, the work supporting panel 23 includes a side 30 which extends perpendicularly from the axis defined by the hinge pin 21, which side 30 is adjacent to the edge 31 of the base 12. The work supporting panel 23 is also formed with a side 32 which extends substantially parallel to the hinge pin 21 and is adjacent to the upper rear edge 33 of the cylinder bed 14.
The cylinder bed 14 is formed adjacent the free extremity of the upper rear edge 33 with a downwardly extending recess 34 of which the upper extremity defines an abutment 35 which is engaged by a stop projection 36 protruding from the edge 32 of the work supporting panel 23 for the purpose of limiting the raised position of the work supporting panel to that in which the work supporting surface 24 is in substantial parallelism with the work supporting surface 19 of the cylinder bed as shown in solid lines in FIG. 1.
The work supporting panel 23 adjacent the edge 30 thereof is formed with a boss 40 formed with an aperture 41 in which a sleeve 42 may be adjustably secured by a set screw 43. Accommodated in the sleeve 42 is the shank portion 44 of a latch detent having an enlarged conical head 45 which protrudes beyond the edge 30 of the work supporting panel 33. The base 12 of the sewing machine bed portion 11 is formed with a latch seat 46 which is positioned so as to accommodate the conical head 45 of the latch detent when the work supporting panel 23 is swung into the raised position.
The work supporting panel 23 is preferably biased in a direction axially of the hinge pin 21 toward the base 12 of the sewing machine bed. Preferably, this bias is provided by a coil spring 50 arranged on the hinge pin 21 between one pair of the respective bosses 20, 20' and 22 which carry the hinge pin. When the work supporting panel 23 is turned into the raised position, therefore, the spring 50 will urge the latch detent into the latch seat and this will releasably lock the work supporting panel into the position shown in solid lines in FIG. 1 in a position effective to support flat shaped work pieces. As shown in FIG. 3, the coil spring 50 will urge the edge 30 of the work supporting panel into closely spaced relationship with the edge 31 of the sewing machine frame base 12 in this position of parts so that a minimum space will be provided therebetween preventing small articles such as pins and the like from dropping therein and an unsightly gap will be obviated.
When the work supporting panel 23 is depressed by the application of a downward force on the work supporting surface 24, movement of the latch detent head 45 out of the latch seat 46 will cam the work supporting panel 23 axially thus to shift the edge 30 of the work supporting panel laterally away from the edge 31 of the sewing machine base 12. The increased space between the edges 30 and 31 as clearly shown in FIG. 4, will insure that marring of the finish of these sewing machine parts will be minimized.
The cooperating latch detent and latch seat described hereinabove can serve without more to releasably lock the work supporting panel 23 in raised position and to shift the work supporting panel axially away from the bed portion base 12 of the sewing machine whenever the panel is depressed so as to minimize marring of the finish.
If for any reason, an additional space is desired between the edge 31 of the bed portion base 12, and the edge 30 of the work supporting panel 23 in the depressed position of the work supporting panel, a vertically arranged cam strip 60 may be secured as by adhesives or the like to the edge 31 of the bed portion 12. The cam strip 60 is positioned for engagement with the edge 30 of the work supporting panel after an initial increment of depression of the work supporting panel and the cam strip is preferably wedged shaped as shown in FIG. 5 to influence a gradual further axial shift of the panel away from the edge 31 of the bed portion base 12 as the panel is depressed.
It is well known to provide a cover which may be placed over a sewing machine and which has a handle by which the sewing machine may be carried. These covers have catches which must engage beneath the work supporting panel 23 to prevent the sewing machine from accidentally falling out of the cover while being carried. The cover catches can only engage properly when the work supporting panel occupies the raised position.
The camming strip 60 provides a safety feature by urging the work supporting panel 23 axially in an augmented distance as shown in dotted lines in FIG. 2 so that a cover will be prevented from being accommodated over the sewing machine when the work supporting panel is depressed.
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A convertible sewing machine bed which includes a base having a longitudinally extending cylinder bed and a spring biased work supporting panel that is movable in one direction with respect to the arm and simultaneously shiftable in another direction with respect to the cylinder bed. The shifting movement is effected by the camming action of a single latch detent being moved into and out of a latch seat. The single latch detent and the latch seat, when in engaging relation, also serve to hold the support member in a work supporting position contiguous to the cylinder bed.
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BACKGROUND OF THE INVENTION
The present invention relates to the use of subatmospheric pressure to expedite refining of molten glass or the like. More particularly, the invention relates to a selected rate and extent of foaming in such a refining technique that yields improved refining performance.
In the melting of glass, substantial quantities of gas are produced as a result of decomposition of batch materials. Other gases are physically entrained by the batch materials or are introduced into the melting glass from combustion heat sources. Most of the gas escapes during the initial phase of melting, but some becomes entrapped in the melt. Some of the trapped gas dissolves in the glass, but other portions form discrete gaseous inclusions known as bubbles or "seeds" which would be objectionable if permitted to remain in unduly high concentrations in the product glass. The gas inclusions will rise to the surface and escape from the melt if given sufficient time in the stage of a melting operation known as "refining" or "fining." High temperatures are conventionally provided in the refining zone to expedite the rise and escape of the gaseous inclusions by reducing the viscosity of the melt and by enlarging the bubble diameters. The energy required for the high temperatures employed in the refining stage and the large melting vessel required to provide sufficient residence time for the gaseous inclusions to escape from the melt are major expenses of a glassmaking operation. Accordingly, it would be desirable to assist the refining process to reduce these costs.
It has been known that reduced pressure could assist the refining process by reducing the partial pressure of the included gaseous species and by increasing the volume of bubbles within the melt so as to speed their rise to the surface. The impracticality of providing a gas-tight vessel on the scale of a conventional refining chamber so as to draw a vacuum therein has limited the use of vacuum refining to relatively small scale batch operations such as disclosed in U.S. Pat. Nos. 1,564,235; 2,781,411; 2,877,280; 3,338,694; and 3,442,622.
Continuous vacuum refining processes have been proposed but have not found acceptable for large scale, continuous manufacture of glass due to various drawbacks. In the continuous vacuum refining arrangements shown in U.S. Pat. Nos. 805,139; 1,509,308; and 3,519,412 a disadvantage is the requirement for relatively narrow vertical passageways leading into and out of the vacuum zone necessitated by the pressure difference. Also, the molten glass is not fully exposed to the vacuum since the incoming glass enters from below a pool of glass.
A different arrangement is shown in U.S. Pat. No. 3,429,684, wherein batch materials are fed through a vacuum lock and melted at the top of a vertically elongated vacuum chamber. Melting raw materials within the vacuum chamber is a disadvantage of that arrangement for three reasons. First, large volumes of foam would be created by carrying out the initial decomposition of the raw materials under vacuum, which would require a vessel large enough to contain the foam. Second, there is a danger that raw materials may follow a short circulation path to the output stream, thus avoiding adequate melting and refining. Third, carrying out the initial stages of melting and heating the melt to a refining temperature within the vacuum vessel require large amounts of heat to be supplied to the melt within the vessel. Such a major heat input to the vessel inherently induces convection currents within the melt that increase erosion of the walls, which leads to contamination of the refined product stream.
U.S. Pat. No. 4,195,982 discloses initially melting glass under elevated pressure and then refining the glass in a separate chamber at a lower pressure. Both chambers are heated.
A preferred technique for vacuum refining glass is disclosed in U.S. Pat. No. 4,738,938 (Kunkle et al.) wherein the creation of foam is deliberately enhanced by introducing the molten glass into the vacuum chamber above the level of the molten glass held therein. Excessive foam was indicated in that patent as being a problem to be avoided. A large space above the liquid container must be provided to accommodate the foam if a large throughput is desired. Since this headspace must also be maintained gas-tight, its construction can be a significant economic drawback, particularly on a large scale process. As a result, the volume of foam acts as a limiting factor to the throughput rate and/or the degree of vacuum that can be utilized.
One measure for maintaining reasonable foam volume that is disclosed in U.S. Pat. No. 4,738,938 is to minimize and, preferably, to eliminate the presence of sulfur, generally present in the form of SO 3 , in the molten glass entering the vacuum chamber. The use of sulfur compounds is common in the glassmaking art as melting and refining aids. But in the vacuum refining technique of the aforesaid patent, the inclusion of sulfur compounds was disclosed to be unnecessary and to be a major source of unwanted foam. Following the teachings of the patent, the deliberate addition of refining aids such as sulfur compounds has been eliminated, and refining has generally been adequate. However, on some occasions, for reasons that were previously not understood, periods of inadequate removal of gaseous seeds from the glass occurred, even though the glass entering the vacuum refiner was very low in gas content and low pressures were used.
SUMMARY OF THE INVENTION
The present invention is based on the surprising discovery that when refining glass or the like by vacuum, glass having a low concentration of gases when entering the vacuum chamber may be refined less adequately by the vacuum than glass having a higher gas content. This finding is contrary to expectations since it would seen that removal of gases would be easiest with the glass having the lowest gas content. But it is now theorized that the thoroughness of the refining is dependent upon the degree of volume expansion produced by the foaming of the melt as it enters the vacuum chamber. The volume expansion of the foam is, in turn, a function of the concentration of relatively volatile substances in the molten glass which enter the gas phase with the reduced pressure of the vacuum chamber. Therefore, even though removal of volatile substances is the overall objective of refining, it appears that the presence of certain amounts of these substances is beneficial to act as foaming agents. At the same time, accumulation of undue amounts of foam within the chamber remains a problem.
The expansion of dissolved and entrained gases as the melt encounters the reduced pressure of the vacuum chamber is advantageously of such a magnitude to render substantially all of the liquid into the membrane walls of the foam structure. Stretching of the membrane walls by further expansion is also desirable because it reduces the thickness of the membranes, which is believed to reduce the size of the largest gaseous seed that can exist within the membranes. Additionally, the more the foam membranes have been stretched, the more readily the foam subsequently collapses. It is an object of the present invention to provide sufficient volume expansion so as to adequately refine the glass and to rapidly collapse the foam while avoiding impractically large accumulation of foam.
It has been found that these objectives can be met by providing in the molten glass entering the vacuum chamber sufficient quantities of materials that will volatilize at the reduced pressure conditions of the vacuum chamber so as to produce a foam having at least eight times the volume of the molten glass liquid. Preferably the foam volume is at least ten times the molten glass volume, and most preferably at least fourteen times. Depending upon the space available in the vessel, foam expansion ratios on the order of twenty or more may require auxiliary means to expedite collapse of the foam in order to limit the height of the foam layer that gathers within the refining chamber.
The expansion ratio is also dependent on the pressure within the vacuum chamber and the vapor pressure of the volatile material at the particular temperature of the melt. Knowing these factors permits the concentration of volatile species required to be present in the glass to yield a desired volume expansion upon foaming to be estimated by using the ideal gas laws.
Substances that may serve as the foaming agent of the present invention are characterized by high vapor pressure at the temperature and pressure conditions within the vacuum refining chamber. Compounds that have been used as refining aids in conventional melting and refining processes are volatile at atmospheric pressure and melting temperatures and, thus, are excellent candidates for actively forming a gas phas when entering the vacuum chamber in accordance with the present invention. These include sulfur and its compounds (e.g., sodium sulfate, calcium sulfate) and halogens and their compounds (e.g., alkali halides such as sodium chloride and calcium fluoride). The specific amounts of these foaming agents that should be present in the molten glass about to be refined will depend upon the particular operating conditions, but typically when sulfur is the primary agent satisfactory results have been obtained when the concentration of sulfur (measured as SO 3 ) in the molten glass entering the vacuum chamber is in the range of 0.010 to 0.040 percent by weight, preferably at least 0.025 percent. In the case of chlorine, the molten glass entering the vacuum chamber may include about 0.01 weight percent chlorine (measured as NaCl) as an example. Since volatilization of the foaming agents is essential to their purpose, the concentration of the foaming agent is substantially reduced in the vacuum refining chamber typically by at least forty percent. Due to their volatility, the concentration of sulfur or halogens is reduced by about 75 percent, and sometimes by as much as 90 percent or more.
The use of typical glass refining aids as foaming agents also yields benefits in initially decreasing viscosity and surface tension of the melt. As a result, foam bubbles an grow more easily so that the bubble membranes are reduced in thickness, thereby making it more difficult for small gaseous inclusions to remain undisturbed within the membrane walls. After the volatile substances are removed from the foam by vacuum, viscosity and surface tension are believed to increase, thereby expiditing collapse of the foam.
THE DRAWING
The FIGURE is a vertical cross-section through a vacuum refining vessel in accordance with a preferred embodiment of the present invention.
DETAILED DESCRIPTION
The detailed description will be set forth in conjunction with a method and apparatus specifically adapted for melting glass and similar glassy materials, but it should be understood that the invention is applicable to the processing of other materials as well.
Although not limited thereto, the present invention is advantageously used in conjunction with a vacuum refining system disclosed in U.S. Pat. No. 4,738,938. In that application an arrangement is disclosed whereby vacuum refining may be employed in a commercial scale, continuous glass melting process in a manner that advantageously and economically overcomes the drawbacks of the prior art. Molten glass is admitted to the vacuum refining chamber only after the majority of the thermal energy required for melting has been imparted to the melt so that little or no thermal energy need by supplied to the molten material contained within the vacuum chamber. Any known arrangement may be used to melt the glass prior to the refining step, but in preferred embodiments, batch materials are first liquefied at a stage specifically adapted for that step of the process such shown in U.S. Pat. No. 4,381,934, and the liquefied material is transferred to a second stage 10, a portion of which is shown in the FIGURE, where dissolution of solid particles is essentially completed and the temperature of the material may be raised to a temperature suitable for refining. Subsequently, the molten material is passed to the vacuum chamber 12. In that arrangement, a large portion of the gaseous by-products of melting are driven off before the material is subjected to vacuum, and the region of greatest gas evolution is separated from the refining zone, whereby materials undergoing the early stages of melting cannot become mixed with portions of the melt undergoing refining. Because most or all of the thermal requirement for melting has been satisfied before the material enters the vacuum refining stage, and heating of the refining stage can therefore be substantially avoided, excessive convection of the melt in the refining zone can be avoided. As a result, vessel erosion is reduced, and the probability of imcompletely refined portions of the melt becoming mixed with more refined portions is reduced. The short residence time of the melting material in the heated area of this arrangement is also advantageous for the sake of retaining volatile refining aids dissolved in the melt so that they can be utilized at the downstream refining zone.
It is preferred to heat the material in the final stage of the melting process (e.g., vessel 10) so as to raise its temperature in preparation for the refining stage to follow. Maximizing the temperature for refining is advantageous for the sake of reducing glass viscosity and increasing vapor pressure of included gases. Typically a temperature of about 2800° F. (1520° C.) is considered desirable for refining soda-lime-silica glass, but when vacuum is employed to assist refining, lower peak refining temperatures may be used without sacrificing product quality. The amount by which temperatures can be reduced depends upon the degree of vacuum. Therefore, when refining is to be performed under vacuum in accordance with the present invention, the glass temperature need be raised to no more than 2700° F. (1480° C.), for example, preferably no more than 2600° F. (1430° C.), and optimally no more than 2500° F. (1370° C.) prior to refining. Peak temperature reductions on this order result in significantly longer life for refractory vessels as well as energy savings. Combustion heat sources could be used in the vessel 10, but it has been found that this stage lends itself well to electric heating, whereby a plurality of electrodes 11 may be provided as shown in the FIGURE extending horizontally through the sidewalls. Heat is generated by the resistance of the melt itself to electric current passing between electrodes in the technique conventionally employed to electrically melt glass. The electrode 11 may be carbon or molybdenum of a type well known to those of skill in the art.
The valve controlling the flow of material from the melting vessel 10 to the refining stage 12 is comprised of a plunger 15 axially aligned with a drain tube 16. The shaft 17 of the plunger extends through the roof of the vessel 10 so as to permit control over the gap between the plunger 15 and the tube 16 to thereby modulate the rate of flow of material into the refining stage. The valve tube 16 may be fabricated of a refractory metal such as platinum and is fitted into an orifice at the upper end of the refining vessel, preferably in the roof 18 of the refiner, but a side wall location may also be feasible.
The refining stage 12 preferably consists of a vertically upright vessel that may be generally cylindrical in configuration, preferably with an enlarged upper portion to provide additional volume to contain the foam, and having an interior ceramic refractory lining 20 shrouded in a gas-tight water-cooled casing. The casing may include a double walled, cylindrical sidewall members 21 and 22 having annular water passageways, and circular end coolers 23 and 24. The roof 18 may be slightly domed for structural integrity and may also be provided with a fitted cooler 25. Any suitable cooling arrangement may be employed. A layer of insulation (not shown) may be provided between the lining 20 and the cooling jackets.
As the molten material passes through the tube 16 and encounters the reduced pressure within the refining vessel, gases included in the melt expand in volume, creating a foam layer 30 resting on a body of liquid 31. As form collapses it is incorporated into the liquid body 31. Subatmospheric pressure may be established within the refining vessel through a vacuum conduit 32 extending through the upper portion of the vessel. Optionally, a burner 33 may be provided to heat the upper portion of the vessel interior. Introducing the melt at or near the top of the vacuum vessel is preferred because it places the incoming, actively foaming material having the greatest gas content above the other material in the vessel, where the thin foam membranes are exposed to the lowest pressure and the gases escaping from bursting bubbles are most free to escape into the headspace.
Refined molten material is drained from the bottom of the refining vessel 12 by way of a drain tube 35 of a refractory metal such as platinum. The drain tube 35 preferably extends above the surface of the refractory bottom within which it is mounted to prevent any debris from entering the output stream. Leakage around the tube may be prevented by a water cooler 37 affixed to the bottom cooling jacket 24. The flow rate of molten material from the drain tube 35 may be controlled by a conical throttle member 38 carried at the end of a stem 39. The stem 39 is associated with mechanical means (not shown) to adjust the elevation of the throttle member 38 and thus adjust the gap between the throttle member an the tube 35 so as to control the flow rate therefrom. A molten stream 40 of refined material falls freely from the bottom of the refining vessel and may be passed to a forming station (not shown) where it may be shaped to the desired product. Refined glass, for example, may be passed to a float glass forming chamber where the molten glass floats on a pool of molten metal to form a flat sheet of glass.
The height of molten material 31 retained in the refiner 12 is dictated by the level of vacuum imposed in the chamber. The pressure head due to the height of the liquid must be sufficient to establish a pressure equal to or greater than atmospheric at the output to permit the material to drain freely from the vessel. The height will depend upon the specific gravity of the molten material, which for soda-lime-silica glass at the temperatures involved is about 2.3. A height in excess of the minimum required to offset the vacuum may be desired to account for fluctuations in atmospheric pressure, to permit variation of the vacuum, and to assure steady flow through the outlet. In the preferred embodiments of the present invention, a substantial excess height is provided so that the outlet flow rate is not determined by the vacuum pressure, but rather by mechanical valve means. Such an arrangement permits the throughput rate and the vacuum pressure to be varied independently of each other. Alternatively, the pressure at the output could be below atmospheric if the output is provided with pump means to overcome the pressure differential. An example of a pump that is intended for use with molten glass is disclosed in U.S. Pat. No. 4,083,711.
The benefits of vacuum on the refining process are attained by degrees; the lower the pressure, the greater the benefit. Small reductions in pressure below atmospheric may yield small improvements, but to economically justify the vacuum chamber the use of substantially reduced pressure is preferred. Thus, a pressure of no more than one-half atmosphere is preferred for appreciable refining improvements to be imparted to soda-lime-silica glass. Flat glass quality standards generally require absolute pressure less than 100 torr. To optimize the foam enhancement of the present invention, absolute pressure less than 50 torr are preferred. A typical range for float glass quality is 20 to 40 torr. A measure of the degrees of refining is the number and size of gaseous seeds remaining in the product glass. The maximum number of seeds allowed varies according to the intended use of the product, but an example of a high quality level sometimes required for commercial float glass is about one seed per 1,000 to 10,000 cubic centimeters. Seeds less than 0.01 millimeter in diameter are considered imperceptible and are not included in the seed counts. Other glass products such as container glass may permit ten times as many seeds or more.
Table I shows the correlation between the SO 3 concentration of the molten glass immediately prior to entering the vacuum chamber and the seed count of the product glass in an arrangement essentially as shown in the drawing. Examples 1 through 4 represent operation using only raw batch materials as the feed to the process. The SO 3 in examples 1 through 4 was derived from sulfur impurities in the batch materials; no sulfur source was deliberately added to the feed mixture. Examples 5 through 10 represent the initial use of 25% by weight cullet including less than 0.005% by weight SO 3 in the batch mixture. The SO 3 content of the cullet was very low due to its having been subjected to vacuum refining. As a result, the sulfur content of the batch and cullet mixture was significantly reduced, and the SO 3 content of the glass entering the vacuum refiner was reduced, as shown in the table. Although the gas content of the incoming glass was less, the seed counts of the glass after vacuum refining were found to be surprisingly increased. Examples 11, 12 and 13 involve the continued use of low sulfur cullet in the feed mixture, but also include the addition of sodium sulfate to the mixture to increase the amount of SO 3 in the molten glass entering the vacuum refiner, with the result that the seed counts improved. The seed counts reported herein were calculated to a standard thickness of 0.121 inch.
TABLE I______________________________________SO.sub.3 Pressure Output Seed Count(Weight %) (torr) (tons/day) (per square foot)______________________________________1. 0.035 37 15 0.52. 0.024 37 12 0.53. 0.021 37 24 184. 0.025 37 24 115. 0.022 25 24 356. 0.016 37 24 287. 0.014 37 24 468. 0.012 25 24 709. 0.004 37 24 5410. 0.003 37 24 5611. 0.008 37 24 3612. 0.015 37 24 3113. 0.027 37 24 5______________________________________
The examples in Table I represent operations at different periods of time and may involve uncontrolled variables to which may be attributed some of the irregularities in the results. A more carefully controlled series of experiments is set forth in Table II, all of the data being taken from an operating period of a few days in which all conditions were maintained as constant as practical. The pressure was 37 torr and the output was 24 tons per day in all of the examples of Table II.
TABLE II______________________________________ Seed CountSO.sub.3 (weight %) (per square foot)______________________________________1. 0.002 75, 752. 0.010 40, 303. 0.019 25, 154. 0.029 10, 10, 10, 5______________________________________
Table III shows the empirically derived, approximate relationship between the amount of sodium sulfate added to the batch mixture and the resulting SO 3 concentration in the molten glass immediately prior to entering the vacuum chamber. The relationship depends upon the temperature and residence time in the liquefying and intermediate stages upstream from the refining chamber, and therefore may vary somewhat from one installation to another.
TABLE III______________________________________Na.sub.2 SO.sub.4 Added(Parts by weightper 1000 parts by SO.sub.3 in Molten Glassweight of sand) (Weight %)______________________________________0.00 0.0040.138 0.0070.270 0.0100.50 0.0191.00 0.032______________________________________
Instead of adding sodium sulfate or other sulfur-containing material (e.g., calcium sulfate) to the batch mixture, the SO 3 content of the glass may be increased by bubbling a sulfur-containing gas such as SO 2 into the melt upstream from the vacuum chamber. A technique for bubbling SO 2 gas into molten glass is disclosed in U.S. Pat. No. 3,375,095 (Poole).
It is the primary objective of this invention to increase the volume expansion of the material upon foaming. Extending the expansion of the foam has also been found to expedite its collapse, which is desirable for the sake of maintaining a manageable height of foam within the refining vessel. However, it may be preferred to use auxiliary foam breaking means to suppress accumulation of foam, particularly at the higher volume expansion ratios. To this end, it may optionally be desirable to use the techniques disclosed in U.S. Pat. No. 4,794,860. In the preferred embodiment, a conduit may extend into the vacuum vessel for introducing foam-breaking agents such as water into contact with the foam. In the drawing, there is shown an arrangement for injecting the water or other foam-breaking liquid into the refining vessel 12 wherein a tube 41 carrying the liquid terminates within the foam layer 30. The tube 41 may extend into the foam from above or may extend substantially horizontally from an opening in the side wall of the vessel 12 at an appropriate elevation as shown in the FIGURE. The tube 41 may be provided with a water-cooled jacket to enhance its preservation. The pressure difference between the interior and exterior of the vessel will draw the liquid into the vessel.
Another foam-breaking technique that may optionally be employed in conjunction with the present invention is to periodically impose a sudden pressure change on the refining vessel interior. This may take the form of a pulse of reduced pressure from an auxiliary vacuum source. Alternatively, pulses of higher pressure may be provided by periodically opening the refining vessel interior to atmospheric pressure.
The foaming of the molten material as it enters the vacuum refining vessel is caused by enlargement of bubbles and gaseous seeds present in the melt and by relatively volatile substances coming out of solution. Any substance in the molten glass that is in the gas phase or comes out of solution under the conditions of the vacuum refining chamber will contribute to the expansion upon foaming. The bubbles and seeds that refining is intended to eliminate usually include nitrogen and carbon dioxide in addition to SO 3 , but the foaming effects of the nitrogen and carbon dioxide appear to be far less significant than the SO 3 . Water is also present in solution in molten glass, and its foaming effect can be significant. Commercial soda-lime-silica glass typically contains about 0.02 to 0.04 percent by weight later. This is insufficient for water to serve as the major foaming agent, but the amount of water present may be taken into account when calculating by the ideal gas law the amount of SO 3 needed to yield a desired foam expansion ratio. Some of the gas-producing constituents will remain dissolved or will become redissolved in the product glass, and this must also be taken into consideration when calculating the volume expansion during foaming. About 75 to 90 percent of the SO 3 will be extracted from the melt under the preferred vacuum refining conditions, but only about 40 to 50 percent of the water will be removed under the same conditions. For the foaming agents that remain in the glass after refining, solubility is an important consideration to assure that any residual seeds are reabsorbed into the glass and that a gaseous phase is not formed subsequently. The sulfur and halide foaming agents disclosed herein are characterized by high solubility in molten glass, so their small residues in the glass would not be expected to cause downstream bubble problems, nor would the presence of residual water since it is also relatively soluble.
Other variations as would be known to those of skill in the art may be resorted to within the scope of the present invention as defined by the claims that follow.
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In a method of vacuum refining molten glass or the like, sufficient concentrations of volatilizable substances are provided in the molten material. prior to entering the vacuum refiner so as to cause at least an eight-fold volume increase during foaming and thereby increase removal of gases from the molten material.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims priority to German Patent Application No. DE 102 24 549.5, filed May 31, 2002, which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
This invention relates to a steam iron having a steam chamber and a liquid reservoir.
BACKGROUND
In the case of a steam iron with a drip valve, water is introduced drop by drop from the water tank or liquid reservoir into a heated steam chamber. The steam generated in the steam chamber passes out of the sole plate through steam-outlet openings and comes into contact with the article which is to be ironed. The steam pressure in the steam chamber here usually corresponds merely to the atmospheric pressure or is increased by the value made up by the height of the water column in the water tank and the atmospheric pressure exerted thereon.
The steam-outlet openings are usually enclosed by a sole-plate surface, with the result that, in the case of particularly dense articles for ironing, such as denim, and/or an ironing board which is not particularly permeable to steam (e.g., made of wood), the steam pressure which can be generated by a steam iron with a drip valve is insufficient for discharging sufficient steam from the steam-outlet openings. In this case, on account of the articles for ironing not being particular permeable to steam, an elevated steam pressure builds up in the steam chamber, which is in pressure-equalizing connection with the steam outlet openings. The elevated steam pressure of the steam chamber is thus present on one side of the drip valve, said steam pressure opposing the atmospheric and water column pressure on the other side of the drip valve. The quantity of steam applied to the articles for ironing thus further decreases to a considerable extent.
In order to tackle this problem, it has been known for some time flow to connect the steam chamber to a liquid-free region of the water tank (the water tank is not completely filled) by means of a pressure-equalizing tube. By means of this solution, a steam pressure of the steam chamber, once elevated for example by the type of articles for ironing, no longer opposes the atmospheric pressure on the other side of the drip valve.
In practice, the hitherto used detailed solutions for a steam iron with pressure-equalizing device, although achieving an improved result, have not produced a sufficiently satisfactory result. In the case of portable steam irons according to DE 33 28 453, U.S. Pat. No. 2,387,281, U.S. Pat. No. 2,892,272 or GB 1,234,856, problems can arise if the water in the tank of the steam iron is moved back and forth by a normal ironing movement. As a result, for example, the steam directed into the water tank from the steam chamber is condensed on the tank wall by the water waves. With a water vapor to water volume ratio of approximately 1000 to 1, the condensation results in an undesirable drop in pressure and/or negative pressure in the water tank. The pressure fluctuations in the water tank which are generated by the wave movement of the water likewise have a disadvantageous effect on the pressure equilibrium between the steam chamber and water tank and on the pressure present at the drip valve.
It is thus an object of the present invention to provide a steam iron with pressure-equalizing device of the abovementioned type which eliminates the disadvantages of the prior art, which discharges a sufficient quantity of steam in particular even during movement of the steam iron and which manages without modifications which would result in higher production outlay in comparison with conventional technical solutions.
SUMMARY
Various aspects of the invention feature a steam iron of the drip-valve type in which a pressure-equalizing device, such as a connecting tube, is arranged between a liquid reservoir and a steam chamber. The liquid reservoir and the liquid-filling region are preferably each not just liquid-tight, but also gas-tight, at least in a region of a pressure-equalizing passage between the liquid reservoir and steam chamber, such that it is possible to build up a gas pressure in the liquid reservoir. Provided in the region of the wall of the liquid reservoir of the liquid-filling region is a first one-way gas valve, through which ambient air can enter into the liquid reservoir.
Preferably, the first one-way gas valve opens automatically, such as in response to a certain threshold pressure value. It is preferable that the threshold pressure value be at or below atmospheric pressure. Accordingly, under negative gage pressure in the liquid reservoir, ambient air can be introduced into the liquid reservoir through the first one-way gas valve. The inherently disruptive wave movement of the water in the liquid reservoir, as described above, is thus advantageously exploited. The water moving back and forth in the liquid reservoir, usually to a pronounced extent as a result of the movement of the iron, functions effectively as a reciprocating pump or “thermal pump” with the water acting as a moving piston. In the case of the water moving in the liquid reservoir, it is usually the case that one end region of the liquid reservoir is loaded with water to a considerably greater extent than an opposite region. A negative pressure is thus produced in the region of the liquid reservoir with the lower water content. A one-way gas valve arranged in a wall of the liquid reservoir in this negative-pressure region thus allows ambient air to enter, with the result that the movement of the water back and forth in the liquid reservoir leads to continuous replenishing with ambient air through the one-way gas valve.
In a further advantageous embodiment of the steam iron, a second one-way gas valve is provided on a wall of the liquid reservoir or of the liquid-filling region, the second valve allowing gas to pass out of the liquid reservoir in the opposite direction to the first one-way gas valve. This second one-way gas valve is preferably designed such that it opens automatically, such as in response to a positive threshold pressure value in the liquid reservoir, with the result that, in the case of a certain positive pressure in the liquid reservoir, gas is discharged from the liquid reservoir through the second one-way gas valve.
The threshold pressure value of the second one-way gas valve is preferably set at a positive gage pressure of greater than about 50 mbar (in some cases, greater than about 100 mbar), preferably at a level that does not occur during normal use of the steam iron. The second valve has a safety function in that it helps to avoid more extreme pressures in the liquid reservoir or steam chamber when the steam outlet openings are closed.
In some embodiments, the second one-way gas valve is designed as a closure of the liquid-filling region. The closure may latch into the housing or the wall of the liquid reservoir, for example, by means of a snap-in connection. The force which is necessary to release this snap-in connection is defined such that it corresponds to the positive threshold pressure value of the second one-way gas valve.
In some advantageous embodiments of the invention, there is no need for a second connection, requiring insulation and/or sealing, for the pressure-equalizing device between the liquid reservoir and steam chamber. For example, the drip valve may be provided with an inner tube, the cavity of which serves as a pressure-equalizing device.
According to one aspect of the invention, a steam iron has a sole plate with steam outlet openings in steam connection with a steam chamber, a heater that heats the sole plate and the steam chamber for the purpose of generating steam, and a liquid reservoir with a drip valve for supplying the steam chamber with liquid from the liquid reservoir. A pressure-equalizing passage extends between a first opening in the steam chamber and a second opening in a gas-tight region of the liquid reservoir. A first one-way gas valve is arranged between the liquid reservoir and ambient air to permit air to enter the liquid reservoir through the valve while impeding fluid flow from the liquid reservoir to the ambient air.
In some embodiments the one-way gas valve is arranged with respect to the liquid reservoir to cause air to enter the reservoir through the valve in response to motion of reservoir contents during motion of the iron during use. Preferably, the valve repetitively operates in response to normal reciprocating motion of the iron.
The one-way gas valve preferably opens automatically to permit air to enter the reservoir in response to pressure within the reservoir falling to below a predetermined threshold pressure. The predetermined threshold pressure is preferably less than or substantially equal to ambient atmospheric pressure.
In some cases, the drip valve is in the form of a channel defined between a movable rod and a wall separating the liquid reservoir and steam chamber. The rod may be operably connected to a knob exposed on the iron for manual manipulation by an operator, for example. In some embodiments, the rod also defines an internal cavity forming the pressure-equalizing passage between the liquid reservoir and steam chamber, advantageously reducing the number of holes necessarily formed in a lower wall of the reservoir.
The one-way gas valve is preferably located at one longitudinal end region of the liquid reservoir, Such as at a forward end.
In some embodiments, the iron has two such one-way gas valves arranged between the liquid reservoir and ambient air, the gas valves being disposed at opposite ends of the liquid reservoir.
In some instances, the gas valve is in the form of a ball check valve.
Some examples have a second one-way gas valve arranged between the liquid reservoir and ambient air, to permit air to leave the liquid reservoir through the valve. The second one-way gas valve preferably opens automatically to permit air to leave the reservoir in response to pressure within the reservoir rising to above a predetermined maximum threshold pressure. The predetermined maximum threshold pressure is preferably greater than normal reservoir operating pressure.
In some embodiments, the second one-way gas valve is manually openable for filling the liquid reservoir. In this way, the valve also serves as a closure of a liquid filling region.
Another aspect of the invention features a method of controlling, pressure in a liquid reservoir of a portable steam iron, incorporating many of the above-described features.
Another aspect of the invention features ironing clothes with the above-described steam iron.
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
FIG. 1 shows a schematic sectional illustration through a steam iron with pressure-equalizing device, with the water in the liquid reservoir moved to the rear.
FIG. 2 shows the iron of FIG. 1, with the water in the liquid reservoir moved forward.
FIG. 3 shows a schematic sectional illustration of a steam iron with a pressure-equalizing device integrated into the drip valve.
FIGS. 4 and 5 are time-based charts of pressure in the liquid reservoir of a portable steam iron not having a one-way gas valve, at rest and during movement of the iron, respectively.
FIG. 6 is a time-based chart of reservoir pressure in a portable steam iron with a one-way gas valve, during movement of the iron.
Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
FIG. 1 shows, schematically, a longitudinal section through a steam iron 1 with a housing 2 which comprises a handle 3 , a liquid reservoir 4 and a bottom skirt 5 . The liquid reservoir 4 has an essentially longitudinal extent, with a section of lesser height 4 a and a section of greater height 4 b . As is customary, the liquid reservoir is never completely filled with water, with the result that the section of lesser height is readily filled up with water and the section of greater height 4 b retains a water-free region with air remaining therein. A closure 6 is formed in a front region of the liquid reservoir and can be opened by sliding or pivoting, with the result that water can be filled into the liquid reservoir. The closure preferably has a snap-in connection, with the result that it can be closed by snap-in action on the wall adjacent to the liquid reservoir or housing 2 . Sealing means 7 are provided about the closure 6 adjacent to the wall of the housing 2 . The water-enclosing wall of the liquid reservoir and of the liquid-filling region 17 with closure 6 and sealing 7 is not just liquid-tight, but is also gas-tight, such that it is possible to build up a gas pressure in the liquid reservoir.
A die-cast body 8 is provided in a bottom region of the steam iron 1 . A heating device 9 is cast in the die-cast body 8 . The die-cast body has a cavity or a recess which serves as a steam chamber 10 . The steam chamber 10 , along with the adjacent die-cast body 8 , is closed at the top by a steam-chamber cover 11 . A sole plate 12 with an ironing surface is formed in a bottom region of the die-cast body. The sole plate 12 may be fastened, as a sheet-metal part, in a composite arrangement on the cast body 8 , or may be formed directly by the underside of the cast body 8 . The sole plate 12 defines a plurality of steam-outlet openings 13 which are in steam connection with the steam chamber 10 .
The steam iron 1 also has a drip valve 14 , which may be designed, for example, as a recessed channel in a longitudinal rod. Through the lateral recessed channel in the rod, water from the liquid reservoir 4 passes drop by drop into the steam chamber 10 . The water droplets come into contact with the hot inner side of the steam chamber and evaporate. At the other end of the rod-like drip valve 14 , a steam regulator 15 is provided on the top outer side of the housing. The steam regulator 15 allows adjustment of the quantity of water let into the steam chamber 10 and/or the quantity of steam generated.
Also provided is a pressure-equalizing device 16 which is designed as a tube, The first opening 16 a of the pressure-equalizing device 16 projects into the steam chamber 10 . The second opening 16 b , or the other end of the tube of the pressure-equalizing device 16 , projects into the higher region 4 b of the liquid reservoir 4 . The second opening 16 b thus terminates in a region of the liquid reservoir 4 which is not wetted by the watch of the liquid reservoir 4 when the steam iron is either horizontal (e.g., during use) or vertical (e.g., when standing). The pressure-equalizing device 16 ensures pressure equalization between the steam chamber pressure and the pressure in the liquid reservoir. This is important, in particular, when, as a result of particularly dense articles being ironed, for example, it is barely possible for steam to pass out of the steam-outlet openings.
A first one-way gas valve 18 is arranged at one end section of the liquid reservoir, preferably in the longitudinal direction, preferably in the closure of the liquid-filling region 17 . The first one-way gas valve is purely a gas valve, that is to say it is liquid-tight. It is designed, for example, as a ball valve and opens in response to a predetermined threshold pressure value. This threshold pressure value is preferably negative (i.e., below atmospheric pressure) or zero (i.e., substantially equal to atmospheric pressure), such that when pressure in the liquid reservoir 4 is negative, ambient air passes into the liquid reservoir through the first one-way gas valve 18 , immediately reducing or equalizing the negative pressure in the reservoir. In some cases, a further first one-way gas valve 19 is arranged it the other end region of the liquid reservoir, more or less opposite the first one-way gas valve 18 , and also allowing air to pass into the reservoir in response to locally negative reservoir pressure.
Also provided in the region of the liquid-filling region 17 is a second one-way gas valve, which opens automatically in the case of a predetermined positive pressure value in the liquid reservoir, for dissipating excess positive pressure in the reservoir.
The second one-way gas valve 20 may be designed in a manner, analogous to the first one-way gas valve 18 , for example as a ball valve, although in this case it is spring-loaded and acts in the opposite direction to the first one-way gas valve. The spring pressure to which the ball is loaded in this case defines the threshold pressure value from which the second one-way gas valve 20 opens. Alternatively, the second one-way gas valve may be formed integrally with closure 6 without conventional valve devices such as a ball valve. For example, closure 6 has a snap-in connection in relation to the housing 2 which opens in response to a predetermined force applied from within the liquid reservoir. This opening of the closure 6 thus corresponds to an opening of a second one-way gas valve 20 .
FIG. 1 shows the steam iron being moved forward in the longitudinal direction, towards the tip of the sole plate. The water 21 located in the liquid reservoir 4 has collected predominantly in a rear region of the liquid reservoir. The front region of the liquid reservoir in this case has rather a low liquid content, a negative pressure being generated in the front region by the movement of the water. This negative pressure, however, is immediately dissipated by the first one-way gas valve 18 , with the result that it is not transmitted from the liquid reservoir 4 to 15 the steam chamber 10 via the pressure-equalizing device 16 . Without the first one-way gas valve, in the case of a negative pressure in the liquid reservoir, steam is taken into the liquid reservoir from the steam chamber, with the result that a smaller fraction of the steam passes out of the steam outlet openings 13 .
FIG. 2 shows the same steam iron as in FIG. 1, the difference being that the steam iron is being moved in the rearward direction, as a result of which more of the water 21 in the liquid reservoir 4 is collected in the front region of the liquid reservoir 4 . The water and more of a positive pressure are thus present at the first one-way gas valve 18 , with the result that the latter remains closed. The optional additional one-way gas valve 19 operates analogously to the first one-way gas valve 18 and, in the case of the movement of FIG. 2, releases the opening in order to equalize the negative pressure adjacent to the one-way gas valve 19 . The one-way gas valve 19 is arranged, in FIGS. 1 and 2, in a rearmost region of the wall of the liquid reservoir 4 . It is also possible, however, for it to be arranged adjacent to the handle, and level with the first one-way gas valve 18 , on the wall of the liquid reservoir.
The water moving back and forth in the liquid reservoir 4 thus acts in a manner similar to a reciprocating pump and draws ambient air into the liquid reservoir 4 through the one-way gas valve 18 (and, if included, also through valve 19 ). In order that the one-way gas valves 18 and 19 act in optimum fashion relative to the pressure in the pressure chamber 10 , it is advantageous if they are arranged adjacent to the second opening 16 b (or 22 b for the embodiment of FIG. 3) of the pressure-equalizing tube 16 . In addition, the one-way gas valve(s) 18 and 19 are ideally arranged for it to be possible for a significant negative pressure to be produced adjacent the valve(s) by the movement of the water in the liquid reservoir 4 .
FIG. 3 shows a steam iron 1 which is designed analogously to the steam iron according to FIGS. 1 and 2, the difference being that the rod-like drip valve 14 has an internal cavity 22 which serves as the pressure-equalizing device. In the same way, the first opening 22 a of the pressure-equalizing device 22 terminates in the steam chamber 10 and the second opening 22 b of the pressure-equalizing device 22 terminates, in the vicinity of the steam-regulating knob 15 , at a lateral opening of the drip-valve rod 14 within the liquid reservoir 4 . The drip valve 14 , in the same way, is recessed laterally as a lateral channel in the wall of the rod or tube, with the result that the quantity of water fed to the steam chamber can be adjusted by way of this channel. This design provides just a single through-passage or a single opening in the base of the liquid reservoir and in the steam-chamber cover 11 , with the result that it is also the case that sealing 23 is only necessary around this one opening.
FIG. 4 shows a chart of reservoir pressure with time plotted on the horizontal axis and a pressure in mbar is plotted on the vertical axis. The curve illustrated shows the pressure in the liquid reservoir in the case of a steam iron with a pressure-equalizing device but without a first one-way gas valve as described above, with the iron at rest. Accordingly, there is no wave movement in the liquid reservoir or sloshing of the water back and forth, with the result that no serious pressure fluctuations occur.
FIG. 5 shows the same pressure measurement as in FIG. 4, with the steam iron being moved back and forth. The wave movement of the water results in negative pressures which, on account of the connection to the steam chamber, affect the passage of the steam out of the steam outlet openings.
FIG. 6 shows a chart of reservoir pressure with, once again, reservoir pressure in mbar illustrated on the vertical axis and elapsed time illustrated on the horizontal axis. Once again, the pressure in the liquid reservoir is measured during simultaneous movement of the steam iron and the contents of its liquid reservoir. In this case, however, a steam iron 1 according to FIGS. 1 to 3 has been used, a first one-way gas valve 18 being provided in the steam iron. It is thus possible overall to build up a somewhat higher pressure in the liquid reservoir, in which case negative pressures occur less often and to a lesser extent. Thus, despite the movement of the steam iron, a largely constantly high steam output at the steam outlet openings is possible. It is possible to achieve a constantly high quantity of steam irrespective of the nature of the articles being ironed and irrespective of the movement of the steam iron.
The steam iron is operated as follows: liquid drips into a steam chamber via a liquid reservoir, with the result that steam is generated in the steam chamber. The steam leaves a sole plate of the steam iron through steam outlet openings connected to the steam chamber. During normal movement of the iron back and forth, ambient air is let into the liquid reservoir via a one-way gas valve and an otherwise gas-tight design of the liquid reservoir, since the movement of the iron back and forth also moves the water located in the liquid reservoir back and forth, with the result that, in the manner of a piston of a reciprocating pump or a thermal pump, it generates a local negative pressure in the region of the liquid reservoir with a lower water content. A one-way gas valve arranged in this region thus allows ambient air into the liquid reservoir. The disruptive wave movement of the water in the liquid reservoir in the case of a steam iron that also has a pressure-equalizing device between the steam chamber and the liquid reservoir is thus exploited because pressure fluctuations in the liquid reservoir are compensated for by the movement of the water back and forth, with the result that it is possible to build up an overall higher pressure via the pressure-equalizing device.
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.
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Steam iron having a sole plate with a steam chamber, and a sealed liquid reservoir. A drip valve supplies the steam chamber with liquid from the liquid reservoir. One or more one-way gas valves between the liquid reservoir and ambient air let air enter the reservoir in response to local negative pressures within the reservoir caused by movement of water within the reservoir, such as during reciprocal ironing motion. A pressure-equalizing passage is formed within a manually operable rod of the drip valve, such that only one opening is required in the lower wall of the liquid reservoir.
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TECHNICAL FIELD
[0001] The field of the invention is that of semiconductor substrate and integrated circuit manufacturing, in particular semiconductor substrate and device having a deuterated buried layer.
BACKGROUND OF THE INVENTION
[0002] Hydrogen passivation has become a well-known and established practice in the fabrication of semiconductor devices. In the hydrogen passivation process, defects which affect the operation of semiconductor devices are removed. For example, such defects have been described as recombination/generation centers on active components of semiconductor devices. These centers are thought to be caused by dangling bonds which introduce states in the energy gap which remove charged carriers or add unwanted charge carriers in the device, depending in part on the applied bias. While dangling bonds occur primarily at surfaces or interfaces in the device, they also are thought to occur at vacancies, micro pores, dislocations, and also to be associated with impurities.
[0003] Another problem which has arisen in the semiconductor industry is the degradation of device performance by hot carrier effects. This is particularly of concern with respect to smaller devices in which proportionally larger voltages are used. When such high voltages are used, channel carriers can be sufficiently energetic to enter an insulating layer and degrade device behavior. For example, in silicon-based P-channel MOSFETs, channel strength can be reduced by trapped holes in the oxide which lead to a positive oxide charge near the drain. On the other hand, in N-channel MOSFETs, gate-to-drain shorts may be caused by electrons entering the oxide and creating interface traps and oxide wear-out.
[0004] It is known in the art of integrated circuit fabrication that passivation of defects at the interface of the gate insulator and the semiconductor substrate of an in insulated gate field effect transistor (IGFET, including MOSFET) by deuterium offers advantages in improving device reliability compared with passivation by hydrogen or other methods.
[0005] It is also known that there are significant problems in implementing such passivation. Deuteration of the interface is conventionally done by annealing the wafer in deuterium before, during, and/or in the back end of line (BEOL) process.
[0006] If the deuteration of the interface is performed before the back end of line (BEOL) processing steps, the subsequent elevated temperatures will cause the deuterium to diffuse away from the interface and thus degrade the benefits of the deuterium. It has been proposed that the deuterium could be preserved by adding a diffusion barrier cap (e.g. a nitride cap) above the gate after the deuterium anneal, but this cap layer adds process complexity and cost.
[0007] When the deuterium anneal is done during or after the BEOL process, the anneal temperature must be less than 450° C. in order to avoid damage to the metallization. This low temperature means that the anneal time must be much greater than a corresponding anneal at a higher temperature in order to assure that the deuterium diffuses through the multiple interconnect layers in the back end to reach and passivate the gate oxide interface defects.
[0008] In addition, performing the deuterium anneal after BEOL process results in low deuteration efficiency because most interface defects may have already been passivated by hydrogen, since hydrogen is present in the BEOL processes such as film deposition, etching, ion implantation and cleaning, etc.
[0009] The art could benefit from a method of deuterium passivation that is economical to perform and a structure having a reservoir that supplies deuterium in the entire processing.
SUMMARY OF THE INVENTION
[0010] The invention relates to a method of supplying deuterium for defect passivation in silicon-on-insulator (SOI), or similar, a semiconductor substrate and integrated circuits by adding deuterium to the buried insulator (BOX) in the wafer, so that deuterium in the buried insulator diffuses upward to the semiconductor device layer to passivate defects in the entire processing.
[0011] Another feature of the invention is a semiconductor substrate having a deuterated buried insulator.
[0012] Yet another feature of the invention is the formation of a semiconductor device having a deuterated buried insulator.
[0013] Yet another feature of the invention is formation of semiconductor substrate and device having a deuterated buried insulator so that deuterium in the buried insulator diffuses upward to passivate defects in the gate insulator and at the interface between the gate insulator and semiconductor body.
[0014] Yet another feature of the invention is formation of semiconductor substrate and device having a deuterated buried insulator so that deuterium in the buried insulator diffuses upward to the gate insulator interface to replace deuterium that has diffused away from the interface.
[0015] Yet another feature of the invention is semiconductor substrate having a deuterated buried insulator so that deuterium in the buried insulator diffuses upward to the gate insulator interface to passivate the interface defects in the entire processing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 shows a step in the wafer bonding process.
[0017] FIG. 2 shows a bonded wafer with a deuterated buried oxide.
[0018] FIG. 3 shows schematically the process of forming a deuterated SIMOX wafer.
[0019] FIG. 4 shows a cross section of a FET on a deuterated wafer.
[0020] FIG. 5 shows schematically the process of adding deuterium to a wafer before bonding.
DETAILED DESCRIPTION
[0021] FIG. 1 and FIG. 2 show in simplified form the wafer bonding process according to the invention. Bonded wafers are commercially available and have reached an advanced stage of development. Typically, two wafers each have a layer of oxide formed on one surface, referred to as a bonding surface, the two oxide layers being pressed together at an elevated temperature to bond the wafers and to form the buried oxide (BOX), also referred to as a separation layer or a layer of bonding insulator, that isolates the device layer from the substrate.
[0022] FIG. 1 shows wafer substrate 10 has a layer of oxide 5 formed on it, preferably by a wet oxidation process. Deuterium, denoted by the letters D, has been incorporated in the oxide by any of a number of methods (illustrated in FIG. 5 ). A counterpart wafer 20 has a layer of oxide 25 formed on it.
[0023] For example, at least one chemical species containing deuterium may be used to form the oxide. The oxide can be formed by oxidation or deposition process such as chemical vapor deposition (CVD). For example, D2, D2O, and/or ND3 can be used in the oxidation process and SiD4 and/or deuterated tetra-ethyl-ortho-silicate (TEOS) can be used in the deposition process. Alternatively, the oxide (or the substrate before oxidation) may be exposed to a deuterium plasma. As another alternative, deuterium may be implanted in the oxide (or the substrate before oxidation). It is an advantageous feature of the invention that the depth of penetration of the deuterium is not important, since the normal diffusion process will even out the distribution. FIG. 5 illustrates schematically the deuteration process, in which box 30 represents the gas source in the oxidation process or the starting materials in the deposition process, the plasma and its source is the plasma process, or the implanter and the ions in the ion implantation process.
[0024] FIG. 2 shows the two layers of oxide bonded together in a conventional process, well known to those skilled in the art, to form the combined wafer having substrate 10 , BOX 15 , and device layer 20 ′ that has been formed by thinning the substrate 20 in a conventional process such as cleaving, lapping, chemical-mechanical polishing and/or etching to a thickness appropriate to the then-current technology. At present, device layers are about 50 to 100 nanometers thick.
[0025] The quantity of deuterium incorporated in the BOX (referred to as a reserve concentration) is not critical and need only be sufficient to supply deuterium to passivate the defects in the interface between the device layer and the gate insulator and replace the amount that diffuses away from the interface sites in the interface between the device layer and the gate insulator or that is dislodged by hot electrons in the course of transistor operation, so that a stable concentration of deuterium is maintained in the device layer. The term “stable” as used herein does not necessarily mean uniform and a slowly-varying distribution of deuterium having a peak in the BOX and a gradient extending to a lower value at the interface between the device layer and the gate insulator. Since the diffusion rate at normal operating temperature of an integrated circuit is much lower than the rate during processing, the concentration of deuterium at the interface will vary so slowly during operation of the finished device that the device characteristics will not noticeably change.
[0026] As indicated above, the location and distribution of the deuterium is not important, since the hot processes in transistor formation will diffuse the initial concentration. Thus, the deuterium may be deposited on the top surface of substrate 10 before oxidation, combined with the oxide during the oxidation process, or implanted in the oxide after the oxidation.
[0027] FIG. 3 indicates an alternative method of forming the BOX, referred to as the Separation by Implantation of Oxygen (SIMOX) process, in which oxygen ions are implanted into the wafer to form the BOX. In this process, base 10 is the same as before in FIG. 1 , but BOX 15 is formed by the distribution of oxygen ions 50 that have an energy sufficient to penetrate to the depth of device layer 20 ′ followed by a high temperature anneal. Deuterium species may be added to the ion stream or implanted before or after the oxygen ions. Alternatively, deuterium species may be implanted into the BOX layer after the high temperature anneal.
[0028] Whether wafers with a deuterated buried insulator are produced by bonding or by implantation does not matter for the practice of the invention.
[0029] FIG. 4 shows in cross section a completed planar field effect transistor on a substrate according to the invention. The transistor, denoted generally with numeral 100 , and representing schematically the set of transistors in an integrated circuit, has silicon body 110 formed in device layer 120 , adjacent to deuterated BOX 15 and bracketed by source and drain 112 . Gate oxide 115 is disposed above silicon body 110 and below gate electrode 130 . Conventional sidewall spacers 122 separate the gate electrode from the source and drain. Shallow trench isolation (STI) 140 isolates the transistor from neighboring devices.
[0030] In the course of the transistor formation process, deuterium in BOX 15 will diffuse vertically upward and passivate defects such as dangling bonds at interface 117 between the top surface of device layer 120 and gate oxide 115 .
[0031] Furthermore, since the concentration of deuterium in BOX 15 (referred to as a reserve concentration) is higher than the concentration at the interface 117 , BOX 15 acts as a reserve source of deuterium and supplies additional deuterium to diffuse upward to replace deuterium that diffuses into the gate electrode. Alternatively, deuterium can diffuse through STI 140 to the device layer 120 and other layers above the layer 120 . The magnitude of the deuterium concentration will be set empirically to supply enough deuterium to perform the passivation and supply replacement deuterium. Diffusion in the horizontal direction is not a concern because the concentration of deuterium is substantially constant to the left and right of the transistor body, so that lateral diffusion out of the transistor is balanced by diffusion in.
[0032] A vertical diffusion path from the BOX to the interface 117 is denoted by the vertical arrows 114 extending across body 110 .
[0033] Preferably, the deuterium is added to the BOX such that the concentration peaks at or near the top surface of the BOX, so that the diffusion path to the interface is as short as possible, thereby encouraging the deuterium to diffuse upward rather than downward. Those skilled in the art will appreciate that the gate insulator may be oxide, nitride, a mixture of oxide and nitride, and/or other suitable dielectric materials such as hafnium-based high-k dielectric materials; the buried insulator may also contain nitride; the device layer may be a silicon-germanium alloy, germanium or other semiconductor; and the device layer may be strained in a conventional process, well known to those skilled in the art.
[0034] While the invention has been described in terms of a single preferred embodiment, those skilled in the art will recognize that the invention can be practiced in various versions within the spirit and scope of the following claims.
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A method and structure for forming an SOI substrate and integrated circuit built on the SOI substrate contain deuterium in the buried insulator layer of the substrate. Deuterium in the buried insulator layer acts as a reservoir to supply deuterium in the entire device manufacturing process. It is in a quantity sufficient to diffuse out of the buried insulator layer to reach and passivate defects in the gate insulator and at the interface between the transistor body and the gate insulator and to replace deuterium that has diffused away from the interface.
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FIELD OF THE INVENTION
This invention relates to alloys for use in the manufacture of jewelry, and more particularly, to a gold based alloy containing primarily gold, copper, silver and zinc, generally in the 10 to 18 karat range composed in a formula creating a unique peach or orangish color gold alloy.
BACKGROUND OF THE INVENTION
The basic elements of the gold based alloy of the present invention, primarily gold, copper, zinc and silver are well known and frequently used in the jewelry industry. This invention uses these elements (other than the gold component for standard karat contents, 10-18K) in amounts and ratios believed undisclosed in the art to create a gold alloy with an entirely new color and character. In examination of the known prior art, what is found reveals no attempts to create a gold jewelry alloy of a very unusual, and separate color, having an improved aesthetic relationship between typical skin tones and jewelry related materials such as gemstones.
Prior work has mainly shown improvements on existing "standard" colors as it would relate to specific metallurgic properties, or the maintenance of standard colored alloys while lowering or altering gold content for an economic advantage.
Other prior art alloys have disclosed ideas that relate to very broad ranges of gold content, but formulate very small amounts of a variety of elements that perhaps create a characteristic (reversible hardness, a spring effect, or deoxidant, etc.) that is generally applicable only to a very small segment of jewelry manufacturing. This invention targets a specific karat span, and a relatively small variable range for the acceptable formula.
Standard colors of gold known to the manufacturing of jewelry are yellow, white, green and rose or pink and are generally alloyed to form a 10 karat to 18 karat gold product. The jewelry industry as a whole is believed lacking an alloy of any kind that has a complimenting color to the skin tones it is typically worn against. From an aesthetic point of view, the problems prior art metals have had are the yellows were very cool tones, while the pink or rose alloys were very warm tones, offering only metals of high contrast to most skin tones. The present invention addresses this problem with an alloy that is very much a mid-tone in terms of color and "temperature" but still maintains the important metallurgic characteristics of known quality karat golds, e.g., high degree of lustre and shine, tarnish and corrosion resistance, resistance to cracking, surface smoothness and very good wear and durability properties.
Other requirements for an alloy to be practically utilized in the jewelry industry are that it can readily be cast, soldered or cold worked, such as forging and rolling. Preferable metallurgic and physical properties for a gold jewelry alloy include a moderate level of hardness to extend the jewelry pieces wear and polish life without adversely affecting malleability and ductility. Hardness is also a concern in the area of surface finishing jewelry, i.e., sawing, shearing, filing, tumbling, sanding, and polishing. A high level of malleability and ductility becomes important to an alloy when the manufacturing process includes forging and/or machine forming, or is required to be made into various forms of sheet and wire. A jewelry alloy should also have a level of fluidity that allows smooth, detailed castings. The goods made from the alloy, whether cast or formed should be easily joinable with solders. An ideal alloy would have these properties as well as having excellent memory (ability to hold form) and annealability (a resoftening process using heat).
SUMMARY OF THE INVENTION
A very unique peach or orangish color gold alloy for jewelry is created by the invention. Another object of the present invention is an alloy that has an improved aesthetic and complimentary relationship towards many skin tones and gem stones. It provides for an unusual middle tone, middle temperature (visually) alloy unlike the cool tones of a yellow gold alloy or warm tones of a rose or pink gold alloy.
The main constituents are known elements in the jewelry industry formulated in very unusual amounts and ratios. It is believed there is no prior art in this area of unique colored, copper based gold alloys. The main constituents are familiar elements which allows the production of the alloy through finished jewelry manufacturing with conventional techniques and equipment.
The alloy has an increased hardness over standard yellow alloys for extended wear and polish holding properties, yet remains malleable. The alloy maintains an excellent level of castability and formability and polishes to a very lustrous, smooth and durable finish. This alloy and its characteristics may be obtained by the following composition by weight:
______________________________________Gold: about 40% to about 76%Copper: about 20% to about 52%Zinc: about 1% to about 6%Silver: about 1% to about 6%______________________________________
Optional elements which may be present in the alloy by weight are: palladium up to about 3%, platinum up to about 3%, cadmium up to about 12%, lead up to 2.5%, aluminum up to about 3%, iron up to about 2%, nickel up to about 4%, silicon up to about 1%, boron up to about 1%, indium up to about 2%, phosphorous up to about 0.25%.
A presently acceptable general range of percentages of the alloy by weight is as follows:
______________________________________General Range10K 14K 18K______________________________________Gold 41.67-41.67% 58.33-58.33% 75.0-75.0%Copper 47.0-52.0% 33.5-37.5% 20.0-22.3%Zinc 6.1-2.7% 4.3-1.5% 2.5-1.1%Silver 5.4-3.7% 3.8-2.4% 2.3-1.5%______________________________________
A preferred acceptable range of percentages of the alloy by weight is as follows:
______________________________________Preferred Range10K 14K 18K______________________________________Gold 41.67-41.67% 58.33-58.33% 75.0-75.0%Copper 49.5-50.1% 35.0-35.3% 21.16-21.42%Zinc 4.4-3.9% 3.2-2.9% 1.94-1.83%Silver 4.5-4.3% 3.3-3.1% 1.86-1.68%______________________________________
Remaining percentages consist of trace amounts of silicon, nickel, indium, magnesium and iron.
These and various other advantages and features of novelty which characterize the present invention are pointed out with particularlity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages, and the object obtained by its use, reference should be made to the accompanying descriptive matter in which there are illustrated and described preferred embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Detailed embodiments of the present invention are disclosed herein. However, it is to be understood that the disclosed embodiments are merely exemplary of the present invention which may be embodied in various systems. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one of skill in the art to variously practice the invention.
The gold alloy of the present invention is best characterized by its unmistakable peachish or orange coloration. The alloy is visually easily distinguished between other known standard colors, being yellow gold, white gold, green gold and rose or pink gold alloys. The present alloy is more closely compatible with a wider range of skin tones than any of the above "standards."
It is not the intention of the invention to match any particular skin tonality but to reduce total contrast, while offering a new color that has important aesthetic qualities in and of itself. In general, the perception of the alloy is one of a very soft and warm feel as compared to a yellow gold or green gold alloy, yet being much fresher and cooler in color and hue than a rose or pink gold alloy.
The alloy exhibits an excellent level of wearability and can be formed into usual manufacturing stocks such as casting grains, rolled goods such as sheet and wire, and with the addition of cadmium of up to 12%, a solder to match the present invention may be made. Known and usual methods and processes for the casting, fabrication and finishing of jewelry are effective with this alloy.
The constituents melt and create a homogenous mixture easily and within usual melt temperatures of other gold alloys. The preferred metallurgical qualities and preferred qualities are achieved within a relatively narrow composition range. The constituents by weight are:
______________________________________ Range______________________________________Gold: about 40% to about 76%Copper: about 20% to about 52%Zinc: about 1% to about 6%Silver: about 1% to about 6%______________________________________
This composition is based on the use of pure metals (99.9% or better) the alloy is made in a standard crucible melt (gas or electric) and may be fluxed with usual industry flux formulas and technique.
When the melt has evenly mixed, in its molten state, it may be cast into articles of jewelry by the use of either vacuum casting equipment or centrifugal equipment. Usual cooling times and quenching techniques are used to recover castings. A prepared melt in its molten stage, homogeneously mixed, may also be poured into ingots, bars, or grain later to be used as a stock to create rolled sheet, dimensional wires, round wire, solders and castings for the manufacture of jewelry.
Depending upon the exact intended use of the alloy, it may contain lesser amounts of optional elements. Silicon may be included up to about 1%. Silicon acts as a deoxidizer and works especially well in casting but is not recommended for rolling or drawing wire since the silicon may cause cracking when the alloy is worked at room temperature. The addition of phosphorus of up to about 0.25% as a deoxidizer is known in the art to minimize cracking of the alloy during rolling, wire drawing or cold working. Indium may be added up to about 2%, and/or boron, up to about 1% to increase flow properties important to intricate casting. Nickel up to about 4% hardens the alloy and its resistance to corrosion without impairing ductility. Iron up to about 2% can be employed as a color stabilizer but in larger amounts degenerates tarnish resistiveness. Aluminum may be present up to about 3% as a deoxidation agent but can cause brittleness.
To lower melting temperature, lead may be used up to about 2.5%. The present invention may have cadmium added in an amount up to about 12% to produce a solder for the alloy. For tarnish resistance palladium up to about 3% or platinum up to about 3% may be mixed with the alloy.
A preferred combination of optional elements recommended for a casting grain would contain about 0.1% to 0.5% silicon to deoxidize the castings, and indium from about 0.2% to 0.8% to improve fluidity while casting. A preferred addition to produce a produce a product that will respond well to cold working, rolling and drawing of wire is phosphorus in an amount of about 0.05% to 0.15%.
In describing the present invention, it is noted that a key factor in the formulation of the color of the alloy is the percentage relationship by weight between pure gold (a yellow metal), copper (a red metal), and zinc and silver (a white metal). Other white metals may be substituted for the zinc and silver content in an attempt to create the present invention through a varied formula. However, most provide short comings found in either color, metallurgic properties, or both.
It is believed acceptable results can be obtained by substituting the white metal portion of the formula (silver and zinc) with nickel, palladium and indium in part, in combination, or wholly when within the disclosed range of the composition. Though a more narrowly useable range of characteristics generally results these three optional elements may be used: nickel 0% to 12% palladium 0% to 12% and indium 0% to 12% but not to exceed disclosed formula total percentages for silver and zinc.
A presently acceptable general range of percentages by weight in terms of commonly used karats, is as follows:
______________________________________General Range10K 14K 18K______________________________________Gold 41.67-41.67% 58.33-58.33% 75.0-75.0%Copper 47.0-52.0% 33.5-37.5% 20.0-22.3%Zinc 6.1-2.7% 4.3-1.5% 2.5-1.1%Silver 5.4-3.7% 3.8-2.4% 2.3-1.5%______________________________________
A most preferred composition of the alloy by weight in terms of commonly used karats, is as follows:
______________________________________Preferred Range10K 14K 18K______________________________________Gold 41.67-41.67% 58.33-58.33% 75.0-75.0%Copper 49.5-50.1% 35.0-35.3% 21.16-21.42%Zinc 4.4-3.9% 3.2-2.9% 1.94-1.83%Silver 4.5-4.3% 3.3-3.1% 1.86-1.68%______________________________________
Remaining percentages consist of trace amounts of silicon, nickel, indium, and iron.
Currently, the most preferred composition to produce the invention in its most commonly used karats is as follows: 10 karat contains 41.67% gold, 49.67% copper, 4.41% silver, and 4.12% zinc. A 14 karat alloy contains 58.33% gold, 35.26% copper, 3.22% silver, and 3.1% zinc. An 18 karat alloy contains 75.0% gold, 21.28% copper, 1.89% silver and 1.76% zinc.
The optional and trace elements discussed thus far are elements known to the art of alloy development and jewelry manufacturing. The body of these percentages and descriptions are made known with this invention as a means to tune an already well engineered alloy. The main constituents of the invention alloy stand well on their own merits.
Copper is the largest percentage constituent in the alloy (aside from gold). It has a relatively high melting temperature but has good malleability and ductility and tensile strength second only to iron. Copper also works to harden the alloy and provide the red component of the color formula. The zinc content in this invention is important to lower melting temperatures, act as a deoxidizer, harden the alloy, and participate as a whitener in composing alloy color. Zinc, however, does not display a high degree of malleability or ductility. The alloy's silver content is close to that of zinc and is the other participant in the whitening percentage of the alloy to form color. Silver is also chosen for its effect on malleability.
These three constituents alloyed within the general and preferred guidelines of this invention as described, and, additionally alloyed with gold (having superior qualities of malleability and ductility) will produce the present invention.
New characteristics and advantages of the invention covered by this document have been set forth in the foregoing description. It will be understood, however, that this disclosure is, in many respects, only illustrative. Changes may be made in details, particularly in matters of shape, size, and arrangement of parts, without exceeding the scope of the invention. The scope of the invention is, of course, defined in the language in which the appended claims are expressed.
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A gold based jewelry alloy is disclosed of preferably the 10 to 18 karat range containing primarily gold, copper, zinc and silver. This alloy is formulated to create a unique color, a mid-range hue with a fresh, soft appearance that is very complimenting to a variety of skin tones and gem stones. Aside from characteristics of appearance, the alloy disclosed has an increased hardness over standard yellow alloys for longer wear and improved polish holding characteristics. The alloy disclosed has excellent castability and formability and responds well to typical jewelry manufacturing processes (i.e., tooling, stone setting, soldering, remelting, forging and plating). The alloy contains about 40% to about 76% gold, about 20% to about 52% copper, about 0% to about 12% zinc and about 0% to about 12% silver.
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FIELD OF THE INVENTION
The present invention relates to a conduit elbow having a replaceable wear element.
DESCRIPTION OF THE PRIOR ART
Pumping slurries or aggregates of abrasive material has long been practiced, and apparatus particular to this art has long since been available. One of the most persistent problems is wear of those conduit surfaces lying in the path of flow and being bombarded under velocity by abrasive material. Notably affecting bends or elbows, this leads to localized failure of the conduit, even though the greater part of the conduit system remains unaffected.
The problem of failure of a slurry or abrasive conduit elbow has lead to development of replaceable wear elements. A rebuildable slurry conduit elbow having a split outer housing may be see in U.S. Pat. No.4,461 498, issued to Donald R. Kunsman on Jul. 24, 1984. However, this housing is split longitudinally.
It is well know that hardened metal has superior abrasion resistance, and that a wrought metal housing has desirable strength properties. U.S. Pat. No. 5,044,670,issued to Alexander Esser on Sep.3, 1991, exemplifies the use of hardened metal wear surfaces and a wrought steel outer member.
U.S. Pat. No. 3,768,840, issued to Keith Allan Upton et al. on Oct. 30, 1973discloses a passage disposed within a pipe coupling for fluid leakage, this leakage being indicative of component failure.
The use of a fully annular bushing to reinforce an elbow connection to a tube is illustrated in U.S. Pat. No. 1,601,093, issued to Charles E. Widmeyer on Sep. 28, 1926.
One major failing of a conduit system having replaceable wear elements is that, for lack of indication of impending failure, the failure typically occurs during operation. This frequently necessitates shutdown at inopportune times, may cause economic loss due to lost material, and further risks creating unsafe conditions and attendant liability.
Even if the failure is sensed, as by periodically tapping on the conduit system, the sensing procedure may aggravate a component weak spot, unnecessarily reducing the useful life of the component.
Frequently, parts and procedures used to replace the conduit member are time consuming and expensive. A need exists for a rebuildable elbow system indicating impending failure, and which is inexpensive and practical to rebuild.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.
SUMMARY OF THE INVENTION
The conduit elbow assembly of the present invention comprises an outer housing, split radially, and one ore more replaceable inner wear elements or liners. The liner comprises a fully annular conduit, loosely fitting the outer housing, thereby defining a void. Looseness of the fit permits material flowing in the conduit to lodge in the void. This material accumulates, and, particularly if cementitious, hardens, filling the void and supporting the wall of the liner.
The liner, made from heat hardened metal, would normally experience wear to the inner heat hardened surface, followed by eventual failure when pressure of fluent material overcomes the strength of the liner. This usually occurs when the center of the liner, typically strong mild steel, erodes following erosion of the inner, hardened surface, leaving only the hardened outer surface of the liner. The outer surface has the same wear resistant qualities as the inner surface, but being brittle as a result of hardening, fails for lack of support, as had been provided to the inner hardened surface by the mild steel center of the liner.
Material buildup in the void provides the erstwhile lacking support. The value of the outer hardened surface as a wear resistant element may thus be realized.
Holes drilled in the outside of the conduit elbow assembly weep grout or other fluent material upon failure of the liner. This weepage is visible, and provides indication of this failure. Structural integrity of the assembly is unaffected, so that immediate shutdown and repair are not necessary.
Spacers separating the outer housing shells are readily removable to expose the liner for cutting. This speeds disassembly and removal of the liner.
The outer housing has internal taper resulting in a greater internal diameter at the split between housing members further facilitating removal of the liner and subsequent cleaning prior to the rebuilding operation.
The liner may be made in three sections. The center section is the thickest, being subject to abrasive attack. The outer sections may be thinners, and are manipulable to accommodate connected piping of varying dimensions. The conduit elbow assembly thus enables piping outer radius change within the conduit system.
The housing is designed to permit standard, mass produced piping components to be used for liner components. This greatly lowers the cost and improves availability of those components which are intended to be replaced.
An adapter ring is provided to mate outer housing shells of different sizes. The adapter ring is particularly intended to make shells used with metric sized piping compatible with shells used with English sized piping.
Accordingly, an object of the present invention is to provide a conduit elbow assembly having a replaceable wear element that is readily disassembled.
A second object is to provide a conduit elbow assembly having a replaceable wear element using readily available replacement components.
A third object is to provide a conduit elbow assembly having a replaceable wear element and providing visual indication of impending wear element failure.
Another object is to provide a conduit elbow assembly which can connect to an inlet pipe and an outlet pipe of differing dimensions.
A further object is to provide a conduit elbow assembly having a replaceable wear element which wear element contributes to the strength of the assembly.
A still further object is to provide a conduit elbow assembly having a replaceable wear element having an outer housing split radially in the bend of the elbow.
Yet another object is to provide a conduit elbow assembly which traps and accumulates some of the material flowing therein, thus reinforcing the replaceable wear element.
Still another object is to provide a conduit elbow assembly having a replaceable wear element wherein two hardened surfaces of the wear element provide service without dismantling the elbow assembly.
With these and other objects in view which will more readily appear as the nature of the invention is better understood, the invention consists in the novel construction, combination and assembly of parts hereinafter more fully described, illustrated and claimed with reference being made to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partly exploded perspective view of the conduit elbow assembly.
FIG. 2 is a longitudinal cross sectional view of the conduit elbow assembly.
FIG. 3 is a partial longitudinal cross sectional detail view of the conduit elbow assembly, draw to enlarged scale.
FIG. 4 is a fragmentary cross sectional detail view taken from the top center of FIG. 2, showing an alternate embodiment.
FIG. 5 is a fragmentary cross sectional detail view of the conduit elbow assembly, taken from the top right center of FIG. 2, and draw to enlarged scale.
FIG. 6 is a fragmentary cross sectional detail view of piping, taken from the prior art.
FIG. 7 is a fragmentary cross sectional detail view of the present invention connected to piping manufactured to U. S. dimensional standards.
FIG. 8 is a fragmentary cross sectional detail view of the present invention connected to piping manufactured to metric dimensional standards.
FIG. 9 is a side elevational view of a preferred adapter.
Similar reference characters denote corresponding features consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As seen in FIG. 1, the present invention 10 comprises an outer housing 12 having right and left mirror image sections 14, and, preferably, a three part interior tubular replaceable wear elements 16. Dividing the outer housing 12 radially in the center rather than longitudinally results in a generally tubular member, this configuration having greater strength than the almost planar component show in the patent to Kunsman ('498). The center portion 18 of the wear element 16 may be made from a commercially available plumber's elbow, machined to have beveled ends. The outer portions 20 are sections of straight tubing, having a cooperating bevel. These outer portions 20 will hereinafter be referred to as bushings 20.
It would be possible to employ wear element components in configurations other than tubular, provided that such elements were continuous around the periphery thereof, thus defining a conduit therein. Similarly, the term "diameter"will encompass all possible diameters, pertinent to situations in which the conduit is not tubular.
In a second embodiment, the wear element 16 may be made in a single piece equivalent to uniting the three components 18, 20, 20. This would expedite assembly and repair, but would require manufacture of stock specifically for this purpose. The cost would be much greater, and thus availability would be considerably limited.
The outer housing 12 further includes a spacer 22 comprising identical halves 22A, 22B separating right and left housing sections 14, 14. These four components 14, 14, 22A, 22B are clamped together in tight abutment. Commonly available plumbing clamps 24 which surround flanges 26, 26 on adjacent housing sections 14, 14, as for example, manufactured by the Victaulic Corporation, may be used.
Better seen in FIG. 2, the wear element center portion 18 fits loosely within the outer housing 12, defining a void 28 between the outer housing 12 and the wear element 16. Ports 30 are provided in both housing sections 14, 14 to communicate between this void 28 and the exterior of the elbow assembly 10. The wear element 16 is heat treated to impart hardness to the surfaces of the center portion 18 and bushings 20.
During assembly of the invention 10, the inner surfaces 32 of the housing sections 14 are coated with a resilient material, shown in FIG.5, thus providing a permanent release coating 34. The wear element bushings 20 may be manipulated to abut piping P of varying dimensions and angle of connection. A conduit system comprising piping P to which the present invention 10 is connected and another plumbing clamp 24 are shown in phantom lines in FIG. 2. Of course, piping P is continued on the other side of the elbow assembly 10.
The bushing 20 are first inserted through the large, inside ends 36 of one housing sections 14, and moved through the passageway 38 defined therein to the relatively narrow outside end 40 of the housing section 14. The bushing beveled end 42 is oriented to the center of the outer housing 12. The bushings 20 advance until a shoulder 44 abuts an interfering shoulder 46 formed in the housing section 14. The exterior end 48 of the bushing 20 and the end 40 of the housing section 14 are now flush. This arrangement prevents flow of material in the elbow assembly 10 from dislodging the bushing 20 from its proper location within the outer housing 12.
The wear element center portion 18 is then inserted into one of the housing sections 14 until its beveled end 50 contacts the installed bushing 20. The cooperating believed ends 42,50 maintain the wear element components 18,20 in concentric relation, further facilitate separation of two adjacent wear element components 18,20 during disassembly, and provide a partial seal, thus preventing excessive escape of flowing material into the void 28. The remaining housing section 14 is installed over the protruding wear element center portion 18, and the two piece spacer 22 is placed between the housing sections 14, 14. The clamp 24 is then placed over the flanges 26 formed in the large, inside ends 36 of the housing sections 14, and is locked down. The elbow assembly 10 is ready for attachment to the piping P of the rest of the conduit system.
The conduit system for which this elbow assembly 10 is intended is used to transport aggregate particulate material. This material in most cases will be concrete or mortar, although sand, ash, coal slurry, or other materials may be transported therein. Since it is anticipated that the invention will find its most widespread use in pumping concrete, the fluent material being transported will be referred to either as material or as concrete.
As concrete flows through the elbow assembly 10, the innermost wall surface 52 on the outer side of the bend described by the elbow assembly 10 is immediately subjected to abrasive attack. An area of this wall surface 52, always occurring on the discharge or egress side of the elbow assembly 10, starts to wear. The precise size and location of this area may vary, depending upon the nature and velocity of the fluent material.
When concrete flows through the elbow assembly 10, some very fine particles of that concrete, or grout 54, will lodge and accumulate in the void 28, as seen in FIG. 2. Grout 54 hardens in the void 28 and strongly resists radial stresses to the wear element 16, thus reinforcing the wear element 16.
This reinforcement doubles the useful life of the wear element 16. If there were no such reinforcement, the hardened inner surface 52 of the wear element 16 would provide almost all the utility which could be realized.
Referring now to FIG. 3, the wear element 16 is seen to have inner and outer hardened surfaces 52, 58, and a core 60. Hardening treatment penetrates typically no more than 0.06 inches (1.5 mm) into metal, leaving the core 60 untreated. The inner hardened surface 52 has excellent abrasion resistance, but is highly brittle. The untreated core 60, which has little resistance to abrasion, provides strength to support the inner hardened surface 52, without which the inner hardened surface 52 would soon break under abrasive attack. Thus, when the inner hardened surface 52 is worn through, the core 60 quickly erodes, and the outer hardened surface 58 soon breaks for lack of support.
Again referring to FIG. 2, where grout 54 from concrete or mortar has filled the void 28, necessary support is provided. The outer hardened surface 58 now provides a second wear surface, and the full utility of the wear element 16 can be realized.
The rate of wear of the hardened surfaces 52, 58 is slow, so that the elbow assembly 10 may last in daily use for a period of time measurable in months. During a first use, and long before the inner hardened surface 52 is eroded, the void 28 will be filled with grout 54. Prior to a subsequent use on the second day following the first use, this grout 54 will set up, and the outer hardened surface 58 will become serviceable in the capacity of a second wear surface.
When the wear element 16 is worn through, concrete attacks the grout 54 which has filled the void 28. When this grout 54 has been eroded, fluent concrete has access to the ports 30 communicating with the exterior. Concrete then leaks to the outside of the elbow assembly 10, where it is visible to an observer. The observer may then schedule repairs. Since the outer housing 12 has some resistance to wear, immediate shutdown is not necessary, and operations may continue.
Repair requires dismantling of the elbow assembly 10 and replacement of the wear element 16. The clamp 24 is released, and the spacer 22 is removed, thus exposing the wear element center portion 18. This is shown in FIG. 1, although the space between the housing sections 14, 14 is exaggerated. The actual space would be equal to the width W of the spacer 22. The exposed wear element center portion 18 is cut with a torch (not shown), access thereto being provided upon removal of the spacer 22. The housing sections 14 may be separated from one another. The remnant of the center portion 18 and the bushing 20 are removed from each housing section 14. Hardened grout 54 may be removed mechanically or by chemical action. A new wear element 16 is then installed, and assembly may be completed as described above.
A problem frequently encountered is that piping P employed in concrete pumping is manufactured to either U.S. or metric standards, the piping outer diameter being unequal. Two sizes of outer housings 12 of the present invention 10 would therefore be required for any one nominal pipe size, one size for each industrial standard. It is desirable to adapt piping P from both industrial standards to work within one conduit system. Toward this end, an adapter ring 64 is provided enabling a smaller housing section 14A, seen in FIG. 4, to be clamped to a larger housing section 14B, whereby the elbow assembly 10 provides a transition between piping P of two different dimensional standards.
As seen in FIG. 1, the adapter ring 64 is slipped over the housing outer section flange 26. Although the adapter ring 64 is illustrated as a solid annulus, a preferred ring comprises a section of flattened, spiralled wire, seen in side elevation in FIG. 9. A retaining ring as manufactured by the Spirolox Division of Kaydon Ring and Seal, Inc., of St. Louis, Mo., may be used in this capacity. As may be seen in FIG. 4, a gasket 66 forming part of the clamp 24 now seats on a surface even with respect to a corresponding surface 68 of the larger of the two mating flanges 26A, 26B.
It is further possible to provide a housing section 14 capable of mating to piping P of either industrial standard. FIG. 6 illustrates abutment of one pipe P against a second pipe P in the U.S. standard and also illustrates abutment of corresponding metric standard pipes PM, PM. Outer flange diameters A, AA (respectively) of U.S. and metric piping standards are unequal. Similarly, flange thickness B, BB (respectively) are also unequal.
Referring now to FIG. 7, the flange 26 of a preferred embodiment elbow assembly 10A is made to the diameter of the outer flange diameter A of FIG. 6, and of thickness equal to or less than the thickness of a single pipe flange F of the metric standard. The elbow assembly 10 may therefore be mated to piping P adding an adapter 64A selected for this particular combination. This adapter 64A increases flange width to the same dimension B shown in FIG. 6. Therefore, a standard clamp 24 (FIG. 4) may be used to hold piping P from the U.S. industrial standard to the elbow assembly 10A.
The same elbow assembly 10A may also be used with metric piping PM. As shown in FIG. 8, an adapter 64C is used to increase the flange diameter to the same dimension A occurring in the U.S. piping standard. An additional adapter 64B is then installed, thus bringing the combined flange thickness to the same dimension B attained in the union of two pipes P of the U.S. standard. Since the same flange diameter A and the same flange thickness B result from uniting an elbow assembly 10A to piping of either industrial standard, only one size clamp and one size elbow assembly 10A are needed regardless of the piping dimensional standard being used.
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.
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A conduit elbow assembly has a radially split outer housing and a replaceable liner. The liner fits loosely within the housing so that material flowing in the elbow accumulates in the void formed in the housing. The hardened liner is thus reinforced, rendering both inner and outer liner hardened surfaces usable in resisting abrasive attack prior to liner failure. A removable housing member exposes the liner for cutting during replacement. Holes in the outer housing permit leakage of fluent material upon liner failure, thus indicating the need for repair prior to conduit rupture. The assembly is adaptable to accommodate varying pipe dimensions within a particular nominal pipe size.
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CROSS REFERENCES TO RELATED APPLICATIONS
[0001] THIS NON-PROVISIONAL APPLICATION CLAIMS THE BENEFIT OF PROVISIONAL PATENT APPLICATION SERIAL No. 60/408,194, FILED Sep. 3, 2002.
STATEMENTS AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
[0002] NONE
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The invention relates to a large format, plotter-style automated laser engraver which can be used to engrave various materials. It is an object of the present invention to engrave at high speeds with minimal maintenance requirements and increased engraving productivity.
[0005] 2. Description of the Prior Art
[0006] Prior to the introduction of automated engraving machines, human engravers were required to have particular knowledge of workpiece selection, cutting speeds, and related matters. Engravers were also required to have some level of manual dexterity in order to physically engrave a workpiece. Development of automated engraving machines has resolved a number of these problems and reduces the overall skill level required of an operator.
[0007] One common type of automated engraving machine is the laser engraver. Apparatuses utilizing a laser for engraving, or at least writing on, a suitable surface are relatively well known. For example, one such apparatus functions by moving a laser relative to a workpiece which is supported on a work surface and by periodically aiming pulses of collimated coherent light at the workpiece to affect therein an image-wise surface alteration, by a plurality of indentations or pixels selectively placed so that together they form an image. The movement of the laser may be responsive to signals, either directly or by way of a storage, derived from a device which mechanically or optically scans the pattern. The workpiece may consist of any material which is susceptible to the formation of indicia therein as a result of laser beam treatment.
[0008] Basically, laser printing or engraving is carried out by aiming a laser beam at a workpiece, the laser beam being switched on at every image point (pixel) or off at every blank position, as the case may be, to form an image in the workpiece. Gray-scale images are typically generated by changes in the intensity of the laser beam by modulating its pulse width. An encoder connected to the drive of the laser tool head provides position signals (pulses per angular unit) to a processor which in turn energizes the laser as a function of the pulses.
[0009] Such automated laser engraving machines have greatly improved the overall quality and efficiency of the engraving process. Notwithstanding this fact, existing automated engraving machines still have certain limitations. Generally, such engraving processes are less than ideal because pixels are directionally displaced; that is, such pixels are typically not aligned in precise columns and/or rows. The difficulties inherent in energizing a laser render it difficult to provide high-speed engraving processes of acceptable precision with cost-efficient x-y plotters. For example, current large format laser engraving machines are limited to engraving speeds of under 100 inches per second, require frequent maintenance, and require multiple operation steps to engrave; such limitations reduce productivity and increase operating costs. Furthermore, currently available automatic engraving machines are frequently very large, and unnecessarily complex with respect to the number of parts required.
[0010] In light of the foregoing, there is a need for an automated engraving machine that is simple to construct, easy to maintain, and relatively compact in size. The automated laser engraving machine should be able to engrave at high speeds, without requiring frequent maintenance and multiple operation steps.
SUMMARY OF THE INVENTION
[0011] The present invention is an engraving apparatus that substantially obviates limitations and disadvantages associated with prior art engraving machines. The advantages and purposes of the invention will be realized and attained by the elements and combinations particularly pointed out in the appended claims.
[0012] In the preferred embodiment, the automated laser engraver of the present invention has a substantially flat work surface which is protected by a hinged cover. Said substantially flat work surface effectively defines an x-axis and a y-axis. An automated gantry assembly is mounted in general proximity to said substantially flat work surface. Said gantry assembly comprises first and second elongate rails, oriented parallel to one another, along the y-axis of said work surface. A third rail, oriented perpendicular to said first and second rails along the x-axis of said work surface, is movably mounted to said first and second rails using traveling bracket members. Said third rail can be moved to various positions along said parallel first and second rails and, thus, along the y-axis of the work surface. A carriage assembly, which is movably received on said third rail, can travel along the length of said third rail between said parallel first and second rails.
[0013] In the preferred embodiment of the present invention, said traveling bracket members utilize non-recirculating polymer bearings that ride on said first and second rails. Similarly, said carriage assembly also utilizes such non-recirculating polymer bearings that ride on said third rail. Said first, second and third rails are hard coated, anodized rails. Said bearings act to push debris (such as from the engraving process, for example) from said rails, thereby reducing cleaning and maintenance requirements for said gantry assembly. Said non-recirculating polymer bearings riding on said hard coated, anodized rails within the gantry assembly permit the machine to achieve high acceleration and engraving speeds of 120 inches per second and greater with low maintenance requirements.
[0014] A first drive mechanism is used to move said first and second traveling brackets (and, accordingly, the third rail) along the length of said first and second rails, respectively. In the preferred embodiment of the present invention, said drive mechanism comprises at least one stepper servo motor and at least one drive belt. Similarly, a second drive mechanism is used to move said carriage assembly along said third rail. In the preferred embodiment, said second drive mechanism comprises at least one stepper servo motor and at least one drive belt. At least one encoder compensates for drive belt flex and maintains the speed of said first and second traveling brackets, as well as said carriage assembly, at desired levels which improves overall quality of the engraving process. Said at least one encoder provides information for motion adjustments and belt flex compensation to the applicable stepper servo motor(s).
[0015] A beam from an engraving laser is aimed at a workpiece being engraved using an optical assembly mounted on said carriage assembly. As said carriage assembly moves to desired locations relative to a workpiece being engraved, said laser beam engraves the surface of said workpiece. In the preferred embodiment, optics (mirrors and lens) utilized to aim and focus said laser beam are removable for easy cleaning and can be replaced in position without requiring re-alignment.
[0016] Air is conveyed onto the engraving work surface to cool the workpiece and reduce the possibility of fire. In the preferred embodiment, said air flow is supplied through a tube which is mounted at or near said carriage assembly. Air travels through said tube and passes through a plurality of holes along the length of the tube in the general direction of the area where the laser beam strikes the workpiece. Said tube can be rotated to direct such air flow as desired.
[0017] In the preferred embodiment, the redirecting and focusing of a laser beam via the gantry assembly and, thus, the engraving on the surface of a workpiece, is controlled via electronics and a computer. A desired design is scanned or otherwise input into the memory of such computer, and this information is supplied to system electronics. Said computer controls aiming of the laser beam relative to said workpiece via the gantry assembly. Said computer also controls laser pulses directed at the workpiece in order to create a surface alteration on the workpiece which is consistent with the desired image.
[0018] In the preferred embodiment, a computer touch screen, mounted in a convenient location relative to the laser engraver, permits easy data input for management of engraving job(s). Said touch screen can control functions such as focus point determination, job setup, job positioning, speed adjustments, job performance data and job preview zoom. Said computer touch screen also allows an operator to select engraving specifications directly from a host computer's hard drive and run such jobs on the laser engraving machine. Additionally, in the preferred embodiment, said computer touch screen also allows an operator to determine focus points on a laser table work surface, change operating parameters of the system, position a job on the engraving table work surface and adjust engraving speeds.
[0019] A wireless focus mechanism controls the distance, or focal length, between the laser and the workpiece being engraved. In the preferred embodiment, said wireless focus mechanism comprises a diode beam and plunger. Said laser diode beam extends horizontally above the work surface along the length of the x-axis. In the event that the plunger, which is attached to the carriage, touches the workpiece, upward movement of the plunger will cause the diode beam to be broken. When this occurs, the substantially flat work surface is automatically set to a position corresponding to the proper engraving focal length for the object to be engraved.
[0020] In the preferred embodiment, the present invention utilizes two primary focus modes: “auto focus” mode and “bull's eye focus” mode. When the auto focus mode is initiated, a location on a workpiece (text character, logo, etc.) is targeted as the initial focus point. When the job is sent to the laser, the focus mechanism plunger will move over the designated x,y coordinate of the initial focus point and the substantially flat work surface of the engraving table will move upward to meet said plunger. Once the plunger is engaged, a diode beam is broken sending a signal to the controller to stop the table's movement. The controller then sends a signal to move the table down reaching the distance of the programmed focal length, thus bringing the object in focus. As soon as the table is focused in this manner, the subject job can begin engraving.
[0021] The bull's-eye focus mode allows a user to move a pointer to any point on a workpiece situated on said substantially flat work surface. To set the focus point, a user selects the desired point. In the preferred embodiment, the user will then hear an audible alarm, indicating that the desired point has been set. The auto focus plunger will then move over the selected x,y coordinate point, and the engraving table work surface will move upward to meet the plunger. When the table engages the plunger, a diode beam is broken sending a signal to the controller to stop the table's movement. The controller then sends a signal to move the table down reaching the distance of the programmed focal length, thus brining the point on the plate to be engraved in focus. Thereafter, the engraving process can start.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] [0022]FIG. 1 depicts a side perspective view of the laser engraver of the present invention.
[0023] [0023]FIG. 2 depicts a side, partial cut-away view of the laser engraver of the present invention.
[0024] [0024]FIG. 3 depicts an overhead view of the work surface and gantry assembly of the present invention.
[0025] [0025]FIG. 4 depicts a side perspective view of the work surface and gantry assembly of the present invention.
[0026] [0026]FIG. 5 depicts a detailed side view of a second traveling bracket and encoder of the present invention.
[0027] [0027]FIG. 6 depicts a side view of a first traveling bracket and carriage assembly of the present invention.
[0028] [0028]FIG. 7 depicts an end view of a carriage mechanism of the present invention with optical components installed.
[0029] [0029]FIG. 8 depicts a side perspective view of a carriage mechanism of the present invention with an optical component removed.
[0030] [0030]FIG. 9 depicts a detailed view of the plunger of the wireless focus mechanism of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0031] Referring to FIG. 1, the automated laser engraver 100 of the present invention has cabinet body 101 and cover 102 . In the preferred embodiment, cover 102 is hinged and can be opened to provide access to engraving table work surface 200 (not shown in FIG. 1), or closed to protect said work surface. Said cover 102 can be supported by gas-charged struts for easy opening and closing of said cover and, in the preferred embodiment, has see-through window 102 a included therein. Laser engraver 100 also has removable panels 103 with ventilation ports 104 to permit access to the inside of cabinet body 101 . Castors 105 permit laser engraver 100 to be easily moved as desired. Panel face 106 and computer touch screen 107 are presented along the front surface of cabinet body 101 for easy access by an operator.
[0032] Referring to FIG. 2, cabinet body 101 defines a support frame for shelves 108 and 109 , as well as fixed upper surface 120 . Removable panels 103 are also installed along the rear of cabinet body 101 to provide access to the inside of said cabinet body 101 from the rear of laser engraver 100 . Substantially planar engraving table 220 having upper work surface 200 is disposed below cover 102 . Automated elevation mechanism 110 can be used to raise or lower said engraving table 220 , and thus work surface 200 , to a desired level within cabinet body 101 . Computer unit 111 is situated within cabinet body 101 , and is used to control the various functions of laser engraver 100 via electronics. In the preferred embodiment, laser tube 112 is situated on shelf 109 within cabinet body 101 . Laser tube 112 emits a laser beam which is used to engrave a workpiece supported on work surface 200 .
[0033] Referring to FIG. 3, an automated gantry assembly is mounted on fixed upper surface 120 of cabinet body 101 . Said gantry assembly is situated in a fixed position in general proximity to movable engraving table 220 and work surface 200 . Said gantry assembly comprises first elongate rail member 201 and second elongate rail member 202 . First and second elongate rail members are oriented parallel to one another, and together define a y-axis component of work surface 200 . Third elongate rail member 203 is oriented perpendicular to said first elongate rail member 201 and second elongate rail member 202 , thereby defining an x-axis component of work surface 200 . Entire third elongate rail member 203 is movably mounted to said first and second rail members using traveling bracket members 204 and 205 . Said third elongate rail member 203 can be moved to various positions along the length of said parallel first and second elongate rail members 201 and 202 and, thus, along the y-axis of work surface 200 . Carriage assembly 206 , which is slidably disposed on said third elongate rail member 203 , can travel along the length of said third elongate rail member 203 between said traveling bracket members 204 and 205 .
[0034] In the preferred embodiment of the present invention, said first and second elongate rail members 201 and 202 comprise single cylindrical rods. Said third elongate rail member 203 comprises tandem cylindrical rods. Each of said first and second elongate rail members are supported by horizontal support members 218 which are attached to upper surface 120 . Third elongate rail member 203 is supported by horizontal support member 219 , which is affixed to traveling bracket members 204 and 205 . Traveling bracket members 204 and 205 are slidably received on first and second elongate rail members 201 and 202 , respectively. In the preferred embodiment, said traveling bracket members 204 and 205 utilize non-recirculating polymer bearings that ride on the external surface of said first and second elongate rail members 201 and 202 , respectively.
[0035] Carriage assembly 206 is slidably received on third elongate rail member 203 . Said carriage assembly 206 also contains non-recirculating polymer bearings that ride on the external surface of said third elongate rail member 203 . In the preferred embodiment, first, second and third elongate rail members are constructed of hard coated, dual anodized rails. Said bearings act to push debris (such as from the engraving process, for example) from said elongate rail members, thereby reducing cleaning and maintenance requirements associated with laser engraver 100 , generally, and work surface 200 , in particular. Said non-recirculating polymer bearings riding on said hard coated, anodized rail members within the gantry assembly of the present invention permit laser engraver 100 to achieve high acceleration and engraving speeds of 120 inches per second and greater with low maintenance requirements.
[0036] Referring to FIG. 4, a first drive mechanism is used to move said first and second traveling brackets 204 and 205 (and, accordingly, entire third elongate rail member 203 ) along the length of said first and second elongate rail members 201 and 202 , respectively. In the preferred embodiment of the present invention, said drive mechanism comprises at least one electric stepper or servo motor 210 and drive belts 208 and 209 . Said drive belts 208 and 209 advance along pulleys mounted within hubs 214 , 215 , 216 and 217 (obscured from view in FIG. 4). In FIG. 4, pulleys 214 a and 216 a are deployed within hubs 214 and 216 , respectively. Although not shown in FIG. 4, similar pulleys are mounted within hubs 215 and 217 . Similarly, a second drive mechanism is used to move said carriage assembly 206 substantially along the length of said third elongate rail member 203 . In the preferred embodiment, said second drive mechanism comprises at least one stepper or servo motor 207 and at least one drive belt 211 . At least one servo motor encoder 212 compensates for drive belt flex and maintains the accuracy of said carriage assembly 206 at desired levels. Said encoder provides information for motion adjustments and belt flex compensation to the applicable stepper or servo motor 207 .
[0037] Referring to FIG. 5, horizontal support members 218 are mounted to upper surface 120 of cabinet body 101 and provide support for elongate rail member 202 . Traveling bracket 205 is slidably mounted on elongate rail member 202 . Encoder 212 is situated on traveling bracket 205 opposite drive motor 207 . Due to the high-g acceleration and speed of carriage assembly 206 , drive belt 211 could flex and stretch during motion. Encoder 212 , attached to shaft 213 a of carriage assembly pulley 213 , reads directly off of drive belt 211 and compensates for unwanted movement of carriage assembly 206 , thereby increasing overall engraving quality.
[0038] Referring to FIG. 6, horizontal support member 218 is mounted to upper surface 120 of cabinet body 101 and provides support for elongate rail member 201 . FIG. 6 depicts a detailed view of traveling bracket 204 and carriage assembly 206 . Carriage assembly 206 has a lightweight design, and drive belt 211 is attached to the carriage assembly 206 at the center of moment, thus enabling high-g accelerations. Said drive belt 211 is vertically mounted to said carriage assembly 206 , which reduces debris collection on the teeth of said belt. Belt tension is adjustable utilizing a setscrew.
[0039] Still referring to FIG. 6, carriage optical assembly 300 is mounted to said carriage assembly 206 . As said carriage assembly 206 moves to desired locations relative to work surface 200 , and any workpiece situated thereon, said carriage optical assembly 300 directs and focuses a laser beam to engrave the surface of such workpiece. In the preferred embodiment, optics 301 and 302 (a reflector and lens, respectively, obscured from view in FIG. 6) for said carriage optical assembly are removable for easy cleaning and can be snapped back into place without requiring re-alignment. Reflector 301 is mounted within optic casing 301 a, while lens 302 is mounted within optic casing 302 a.
[0040] [0040]FIG. 7 depicts an end view of carriage assembly 206 of the present invention. Referring to FIG. 7, carriage optical assembly 300 is attached to said carriage assembly 206 . Bearings 221 are used to slidably mount carriage assembly 206 to third elongate rail member 203 . Although not shown in this drawing, such bearings are likewise used to movably mount traveling brackets 204 and 205 to first and second elongate rail members 201 and 202 , respectively. Optic casing 301 a , and thus reflector 301 , is mounted within mounting bracket 303 on carriage optical assembly 300 . Similarly, lens casing 302 a , and thus lens 302 (obscured from view in FIG. 7) is mounted within mounting bracket 304 of carriage optical assembly 300 . Spring loaded, nylon tipped set screw 305 can be employed to firmly hold said reflector casing 301 a and lens casing 302 a in place within their respective mounting brackets.
[0041] Mounting brackets 303 and 304 allow optic placement and removal for cleaning and inspection. When casing 301 a and 302 a are installed into said mounting brackets, the optics within said casings can be automatically returned to a position that does not require realignment. Said casings 301 a and 302 a are ideally constructed of aluminum and utilize an anodized color code to instruct proper placement within mounting brackets 303 and 304 .
[0042] [0042]FIG. 8 depicts a side view of carriage assembly 206 and carriage optical assembly 300 , with reflector 301 and associated casing 301 a , removed. Lens 302 , and associated casing 302 a , are installed within lens mounting bracket 304 . A wireless focus mechanism controls the vertical distance, or focal length, between the carriage optical assembly 300 and a workpiece being engraved on work surface 200 of engraving table 220 . In the preferred embodiment, said wireless focus mechanism comprises a diode beam which works in conjunction with plunger 306 . A diode laser beam is directed from port 305 on traveling bracket member 204 shown on FIG. 6. Said diode laser beam is directed across work surface 200 along the length of third elongate rail member 203 . Said diode beam is focused through a port 307 extending through plunger 306 and towards detector 330 on traveling bracket member 205 (shown on FIG. 5).
[0043] [0043]FIG. 9 depicts a see-through view of plunger 306 of the wireless focus mechanism of the present invention. Plunger 306 consists of outer body 308 , internal shaft 309 and port 307 . Although not depicted in FIG. 9, an optional spring can be used to bias internal shaft 309 downward away from port 307 . In the event that internal shaft 309 comes in contact with a workpiece situated on work surface 200 , internal shaft 309 is directed upward within outer body 308 . Internal shaft 309 blocks port 307 , thereby interrupting said diode beam and preventing said diode beam from reaching detection sensor 330 on traveling bracket member 205 . The computer controller recognizes this as the “pre-set” focus point and automatically adjusts the engraving table 220 and work surface 200 to the correct focal distance relative to carriage optical assembly 300 . The process can be directed by an operator through software or through the touch screen keypad.
[0044] A laser beam from laser tube 112 is aimed and focused at a workpiece to be engraved on work surface 200 using a series of reflectors and/or lens. Referring to FIG. 2, a beam from laser tube 112 is emitted from port 112 a . Said beam is redirected upward toward upper surface 120 using at least one aimed reflector (not shown in FIG. 2). In the preferred embodiment, said beam is thereafter aimed at reflector 340 , shown on FIG. 3 which is situated at or near upper surface 120 . Said beam is re-directed by reflector 340 , and aimed at reflector 350 , positioned on traveling bracket 205 . Said beam is again reflected using reflector 350 , and redirected through port 351 towards carriage optical assembly 300 mounted on carriage 206 . Referring to FIG. 6, said beam passes through port 352 , towards reflector 301 . The beam is reflected by reflector 301 and aimed downward through lens 302 at work surface 200 (and any workpiece situated thereon). As can be seen from the various drawings, in this manner said beam can be re-directed (reflected) and focused as desired at different positions on said work surface 200 .
[0045] Air is conveyed onto work surface 200 to cool a workpiece being engraved. In the preferred embodiment, said air flow is supplied through a tube which is mounted at or near carriage assembly 206 , such as tube 400 on FIGS. 5 and 6. Air travels through said tube and passes through a plurality of holes 401 extending through the tube 400 in the general direction of the area where a focused laser beam strikes the workpiece.
[0046] Forced air is used to minimize unwanted flame from engraving certain materials, and pushes debris to a vacuum plenum. In the preferred embodiment, said tube 400 allows for full air flooding onto the material, also helping to cool the engraving material, thereby reducing adverse impact to the material. By rotating the tube, a user can direct the airflow in the desired direction.
[0047] In the preferred embodiment, the movement of the carriage via the gantry assembly and, thus, the engraving on the surface of a workpiece, is controlled via electronics and a computer. A desired design is scanned or otherwise input into the memory of such computer, and this information is supplied to system electronics. Said computer controls movement of a laser beam relative to said workpiece via the gantry assembly described herein. Said computer also controls laser pulses directed at the workpiece in order to create a surface alteration on the workpiece which is consistent with the desired image.
[0048] In the preferred embodiment, a computer touch screen 107 , mounted in a convenient location relative to the laser engraver 100 , permits management of an engraving job. Said touch screen can control functions such as focus point determination, job setup, job positioning, speed adjustments, and job performance data. Said computer touch screen allows an operator to select engraving jobs directly from a host computer's hard drive and run such jobs on the laser engraving machine. Additionally, in the preferred embodiment, said computer touch screen also allows an operator to determine focus points on a workpiece situated on work surface 200 , change operating parameters of the system, position a workpiece for engraving, and adjust engraving speed.
[0049] Referring back to FIG. 1, computer touch control screen 107 is mounted to the front upper panel of the cabinet body 101 and acts as the control interface for the laser engraver of the present invention. Jogging of the gantry assembly, setting home positions, setting job offsets, job preview with zoom, determining focus points, turning on and off air assist, setting blower delay, controlling the audible notifications, turning on the diode laser pointer, toggling between metric and imperial units, using the mottle function, enabling HPGL use, setting the focus offset, accessing test engraving jobs, selecting display languages, pausing, changing power, changing speed, and performing maintenance functions can all be performed by using computer control touch screen 107 .
[0050] It will be apparent to those skilled in the art that various modifications and variations can be made in the construction of this engraving apparatus without departing from the scope or spirit of the invention. Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
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The invention pertains to a large format, plotter-style automated laser engraver which can be used to engrave various materials. A cabinet body supports a substantially flat work surface which can be raised or lowered as desired. A gantry assembly is mounted in close proximity to such work surface, and facilitates movement of a focused laser assembly to any x/y coordinate along the work surface. A computer controlled wireless focus mechanism is used to regulate the vertical distance between the focused laser assembly and the work surface. Air is provided to cool the work surface during the engraving process.
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This is a division application of application Ser. No. 09/523,312, filed Mar. 10, 2000 now U.S. Pat. No. 6,657,181.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an interference measuring apparatus and a grating interference-type encoder for generating a phase difference signal and highly accurately measuring a length and an angle in an industrial apparatus such as FA (factory automation).
2. Related Background Art
A laser interferometer or an incremental encoder has heretofore been utilized as a highly accurate positioning apparatus such as FA. These apparatuses convert positional deviation into a pulse train, and count the pulse number at this time to thereby detect relative positional deviation. At this time, it is also necessary to detect a direction of movement and therefore, usually two or more phase difference signals A phase and B phase are outputted and phase shift of 90° is given with a sine wave signal of a cycle being 360°.
In such a high resolving power incremental encoder and laser interferometer, there is known a method of disposing two detecting optical systems with their spatial positions deviated from each other to thereby generate phase difference signals of A phase and B phase. There is also known a method of causing polarized light beams orthogonal to each other to interfere with each other through a quarter wavelength plate, converting them into a linearly polarized light beam of which the polarization direction rotates correspondingly to the phase difference between the wave fronts of the two light beams, and then further dividing it into a plurality of light beams. Those light beams are caused to be transmitted through polarizing plates disposed with their polarization axes deviated in different directions to thereby generate a phase difference signal light beam.
FIG. 1 of the accompanying drawings shows a perspective view of a non-contact distance sensor of the conventional laser interference-type, and a laser beam L from a coherent light source 1 passes through a collimator lens 2 and a non-polarizing beam splitter 3 and is polarized on the polarizing surface 4 a of a probe-like polarizing prism 4 . S-polarized light reflected by the polarizing surface 4 a emerges from the probe-like polarizing prism 4 toward a slider 5 , is reflected by the surface 5 a to be measured by the slider 5 , and again returns along the original optical path to the polarizing surface 4 a of the probe-like polarizing prism 4 .
On the other hand, P-polarized light transmitted through the polarizing surface 4 a is reflected by the upper reference mirror surface 4 b of the probe-like polarizing prism 4 and likewise returns to the polarizing surface 4 a . These two polarized lights are re-combined on the polarizing surface 4 a , travel through the probe-like polarizing prism 4 , are reflected by a non-polarizing beam splitter 3 , pass through a quarter wavelength plate 6 and an aperture in an aperture plate 7 , and are amplitude-divided by a four-division diffraction grating 8 . These amplitude-divided light beams pass through polarizing plates 9 a – 9 d , and are received by the four areas 10 a – 10 d of a light-receiving element 10 . The minute displacement of the slider 5 is measured by an interference signal at this time.
However, in the above-described example of the prior art, the phase shift is given by arrangement or the like of the polarizing plates 9 a – 9 d and therefore, there is a possibility that if there are an alignment error and manufacturing errors of the polarizing plates 9 a – 9 d , the phase difference signal is not stable. On the other hand, in the case of the interference between linearly polarized lights orthogonal to each other, a space is required for arrangement of optical parts such as the quarter wavelength plate 6 and the four polarizing plates 9 a – 9 d and therefore, the apparatus becomes bulky and the assembly adjustment of all these is necessary.
SUMMARY OF THE INVENTION
In view of the above-described example of the prior art, it is an object of the present invention to provide a compact interference measuring apparatus easy to assemble for collectively detecting a plurality of stable phase difference signals.
It is another object of the present invention to provide an interference measuring apparatus such as a compact and highly accurate grating interference-type encoder.
Other objects of the present invention will become apparent from the following description of some embodiments of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an interference measuring apparatus according to the prior art.
FIG. 2 is a perspective view of an interference measuring apparatus according to a first embodiment of the present invention.
FIG. 3A is an illustration of the phase shift of a wave front by a phase difference rock crystal plate.
FIG. 3B is a perspective view of a push-pull optical system.
FIG. 4 is a perspective view of a push-pull optical system according to a second embodiment of the present invention.
FIG. 5 is a perspective view of an interference measuring apparatus according to a third embodiment of the present invention.
FIG. 6 is a view for explaining production of 90° phase difference bright and dark signal of four phases.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will hereinafter be described in detail with respect to some embodiments thereof shown in FIGS. 2 to 6 .
FIG. 2 shows a perspective view of a first embodiment, and in a non-contact distance sensor 20 , a coherent light source 21 such as a laser diode, a collimator lens 22 , a non-polarizing beam splitter 23 and an optical type probe-like polarizing prism 24 are arranged in succession. The probe-like polarizing prism 24 has a polarizing beam splitter surface 24 a and a reference mirror surface 24 b , and a slider side 25 which is a region to be measured is disposed on the front surface of the probe-like polarizing prism 24 in the direction of reflection of the polarizing surface 24 a.
An aperture plate 26 , a four-division diffraction grating plate 27 such as a hounds-tooth-checkered phase diffraction grating, a phase difference rock crystal plate 28 having four areas 28 a – 28 d of different thicknesses on a substrate, a 45° azimuth polarizing plate 29 having an optic axis in an azimuth of 45° and a four-division light receiving element 30 having four light receiving areas 30 a – 30 d are arranged in succession in the direction of reflection of the non-polarizing beam splitter 23 .
During measurement, a divergent light L from the coherent light source 21 is made into a substantially condensed light by the collimator lens 22 , passes through the non-polarizing beam splitter 23 , and is divided into a transmitted light and a reflected light on the polarizing beam splitter surface 24 a of the probe-like polarizing prism 24 . S-polarized light reflected by the polarizing surface 24 a emerges from the probe-like polarizing prism 24 toward the slider side 25 , and is reflected by the slider side 25 , and the reflected light passes along the original optical path and is returned to the polarizing surface 24 a of the probe-like polarizing prism 24 . On the other hand, P-polarized light transmitted through the polarizing surface 24 a is reflected by the reference mirror surface 24 b in the probe-like polarizing prism 24 , and is likewise returned to the polarizing surface 24 a.
These two polarized lights are combined together on the polarizing surface 24 a of the probe-like polarizing prism 24 , and become a bright-dark signal of an interference light beam by a polarizing interference optical system which will be described later. When the distance between the probe-like polarization prism 24 and the slider side 25 changes, each time the difference between the lengths of the forward and backward optical paths of the two light beams separated by the polarization surface 24 a becomes integer times as great as the wavelength of the coherent light source 21 , the bright and dark thereof changes. That is, if a laser diode of a wavelength 0.78 μm is used as the coherent light source 21 , when the distance between it and the slider side 25 deviates by 0.39 μm, the light and shade change into a sine waveform by a cycle.
This change in the bright and dark is converted into an electrical signal by the light receiving element 30 , and if the distance between the prism 24 and the slider side 25 is preset to such a distance as will be the middle of the bright and dark, when the distance between the prism 24 and the slider side 25 changes minutely, the level of the electrical signal will change sensitively. Accordingly, by the utilization of this sine wave-like change in the level of the electrical signal and by the use of a conventional electric circuit of resolving power capable of dividing a sine wave of a wavelength 0.39 μm into several tens of phases, the change in the distance can be detected with resolving power of the order of 0.01 μm. Also, if there is a 90° phase difference bright-dark signal of two phases, a sine wave can be divided into several tens to several hundreds of phases by the use of a conventional electrical interpolation circuit and therefore, the change in the distance can be detected with higher resolving power of 0.001 μm.
FIG. 3A shows a method of generating a 90° phase difference bright-dark signal of four phases, and at the stage whereat the light emerges from the probe-like polarizing prism 24 , the wave fronts of the two light beams overlap each other, but the light beams are linearly polarized light beams of wave fronts orthogonal to each other and do not interfere with each other to become a bright-dark signal. These light beams are reflected by the non-polarizing beam splitter 23 , pass through the aperture in the aperture plate 26 and are amplitude-divided into four equivalent light beams including two linearly polarized light beams orthogonal to each other by the four-division diffraction grating plate 27 . At this time, these four light beams travel and separate with only their intensities reduced by the division, and enter the rock crystal plate 28 disposed in an appropriate space.
This rock crystal plate 28 is used as an optical phase plate, and has two optic axes, i.e., f-axis and s-axis, and since there is a difference in refractive index between these axes, a linearly polarized wave component in which an electric field component in the electromagnetic wave of light has entered in parallelism to the f-axis emerges with its phase advanced as compared with a linearly polarized wave component in which the electric field component has entered in parallelism to the s-axis. The phase difference Γ (deg) at this time is represented by the following expression when the wavelength of the coherent light source 21 is defined as λ, the refractive index of the rock crystal for an abnormal ray of light is defined as ne, the refractive index of the rock crystal for a normal ray of light is defined as no, and the thickness of the rock crystal plate 28 is fined as t.
Γ=(360/λ)·( ne−no ) t
The refractive index ne for an extraordinary ray of light corresponds to the linear polarized wave substantially parallel to the s-axis, and the refractive index no for an ordinary ray of light corresponds to the linearly polarized light beam parallel to the f-axis. The typical values of the refractive index of rock crystal are ne =1.5477 and no =1.5387 and therefore, t satisfying the phase difference Γ=90 (deg) can be found as follows by substantially λ=0.78 μm, ne=1.5477 and no=1.5387.
t=λ/{ 4( ne−no )}=21.67 μm
In the present embodiment, the rock crystal plate 28 , as shown in FIG. 3B , is disposed so that the f-axis which is an optic axis may be the direction of the S-polarized wave, and is provided with level differences by the etching process so as to assume four different thicknesses of four-square configuration, and the four divided light beams enter respective areas 28 a – 28 d and emerge from the back surfaces thereof. The area 28 a is a portion which is not worked so as to have a level difference and has the original thickness of the rock crystal substrate, and the area 28 b has its portion corresponding to Δt=21.67 μm etching-processed by hydrofluoric acid so that the phase of the wave front of only the S-polarized component may be delayed by 90° as compared with the area 28 a.
The area 28 c has its portion corresponding to 2·Δt etching-processed so that the phase of the wave front of only the S-polarized component may be delayed by 180° as compared with the area 28 a , and the area 28 d has its portion corresponding to 3·Δt etching-processed so that the phase of the wave front of only the S-polarized component may be delayed by 270° as compared with the area 28 a . These three level differences are achieved by effecting the etching of the level difference of 2·Δt once in the areas 28 c and 28 d , and effecting the etching of the level difference of Δt once in the areas 28 a and 28 d.
Light beams (P, S) transmitted through the area 28 a are relatively advanced in the phase of the wave front of the S-polarized wave among the P- and S-polarized waves by the original thickness of the rock crystal plate 28 and the disposition of the optic axis thereof, and the amount of this advance is defined as ΔΦ. As regards the light beams (P, S) transmitted through the area 28 b , the advance of the phase of the wave front of the S-polarized wave is returned by 90° and the amount of phase advance is ΔΦ−90° because the rock crystal plate 28 has become thinner by Δt than the original thickness thereof by etching.
As regards the light beams (P, S) transmitted through the area 28 c , the advance of the phase of the wave front of the S-polarized wave is returned by 180° and the amount of phase advance is ΔΦ−180° because the rock crystal plate 28 has become thinner by 2·Δt than the original thickness thereof by etching. As regards the light beams (P, S) transmitted through the area 28 d , the advance of the phase of the wave front of the S-polarized wave is returned by 270° and the amount of phase advance is ΔΦ−270° because the rock crystal plate 28 has become thinner by 3·Δt than the original thickness thereof by etching.
The light beams (P, S) transmitted through these four areas 28 a – 28 d has its 45° polarized component extracted by the polarizing plate 29 having its optic axis in the azimuth of 45°, and these P- and S-polarized waves are converted into 45° linearly polarized waves while having phase information and, therefore, cause interference therebetween and become bright-dark signal light beams. At this time, the phase-difference between the light beams P and S which have emerged from the respective areas 28 a – 28 d deviates each integer times λ/4 and therefore, the timing (phase) of the bright and dark of the interference light deviates each quarter cycle. Accordingly, these interference light beams enter the four light receiving elements 30 a – 30 d , whereby four phase difference signals are obtained at a time. These four interference light beams have a phase shift at each quarter cycle and, therefore, have the A+ phase, B+ phase, A− phase and B− phase of the 90° phase difference signals, which are four-phase push-pull signals.
In the present embodiment, the four-division diffraction grating 27 , the phase difference rock crystal plate 28 , the 45° azimuth polarizing plate 29 and the four-division light receiving elements 30 a – 30 d are simply disposed in an orderly way and therefore, the work of disposing a plurality of minute polarizing plates or the like becomes unnecessary, and a very simple and compact apparatus can be realized. Particularly, it can be easily realized by processing the diffraction grating 27 , the rock crystal plate 28 and the polarizing plate 29 for each large substrate by a method similar to the semiconductor process, and finally cutting them.
FIG. 4 shows a perspective view of a push-pull optical system according to a second embodiment, and a rock crystal plate 31 in this embodiment is formed with a level difference by the etching process so as to have two different thicknesses in a horizontal direction, and is disposed so that the f-axis which is an optic axis may be the direction of S-polarized wave. This rock crystal plate 31 is designed such that each two of four divided light beams enter areas 31 a and 31 b , respectively, and are transmitted from the back surface thereof, and the area 31 a is a portion which is not worked into a level difference, and has the original thickness of a rock crystal substrate. Also, the area 31 b , as compared with the area 31 a , is worked into a level difference so that only the S-polarized component may be delayed in the phase of a λ/4 wave front, and this level difference is achieved by effecting the etching of a level difference corresponding to λ/2 once in the area 31 b . Also, a polarizing plate 32 in the present embodiment comprises a polarizing plate 32 a having an optic axis in the azimuth of 45° and a polarizing plate 32 b having an optical axis in the azimuth of 135°, the polarizing plates 32 a and 32 b being disposed in a vertical direction.
Of the light beams (P, S) divided in the four-division diffraction grating plate 27 , the left light beam passes through the area 31 a of the rock crystal plate 31 and the right light beam passes through the area 31 b of the rock crystal plate 31 . At this time, the light beams (P, S) transmitted through the area 31 a are relatively advanced in the phase of the wave front of the S-polarized wave between P- and S-polarized waves by the original thickness of the rock crystal plate 31 and the disposition of the optical axis thereof, and this amount of advance is defined as ΔΦ. As regards the light beams (P, S) transmitted through the area 31 b , the advance of the phase of the wave front of the S-polarized wave is returned by λ/4 and the amount of phase advance is ΔΦ−λ/4 because the rock crystal plate 31 has become thinner by Δt than the original thickness thereof by etching.
Of the light beams (P, S) transmitted through these two areas 31 a and 31 b , the upper two light beams pass through the polarizing plate 32 a in the azimuth of 45°, and the lower two light beams pass through the polarizing plate 32 b in the azimuth of 135°, and a 45° polarized component or a 135° polarized component is extracted, but at this tune, the P- and S-polarized waves are converted into 45° or 135° linearly polarized waves while having phase information, and cause interference and become a bright-dark signal light beam.
The wave front phase between the light beams P and S which have emerged from the two areas 31 a and 31 b deviates by λ/4 and therefore, the timing (phase) of the bright and dark of the interference light beam of the light beam transmitted through the polarizing plate 32 a is such that the light beam transmitted through the area 31 b advances by a quarter cycle as compared with the light beam transmitted through the area 31 a. Also, the timing (phase) of the bright and dark of the interference light beam of the light beam transmitted through the polarizing plate 32 b is such that the light beam transmitted through the area 31 b advances by a quarter cycle as compared with the light beam passed through the area 31 a . Here, the bright and dark phase of the light beam transmitted through the polarizing plate 32 a and the bright and dark phase of the light beam transmitted through the polarizing plate 32 b deviate by 180° from each other and, therefore, the phase of the four bright and dark light beams become 0°, 90°, 180° and 270°, and become a four-phase push-pull signal as in the first embodiment.
In the present embodiment, the four-division diffraction grating 27 , the phase difference rock crystal plate 31 , the 45° azimuth polarizing plate 32 a , the 135° azimuth polarizing plate 32 b and the four-division light receiving elements 30 a – 30 d are simply disposed in an orderly way, whereby a very simple and compact construction can be realized. Particularly, the rock crystal plate 31 can be worked by an etching process, and the polarizing plate 32 a and the polarizing plate 32 b are stuck together adjacent to each other, whereby assembly adjustment can be effected relatively simply.
The present embodiment can be applied to a grating interference-type encoder in which coherent light beams divided into two are applied to diffraction gratings moved relative to each other, and diffracted lights of different order numbers are taken out to thereby generate an interference phase signal. It can also be applied to other popular grating interference-type encoders and interference measuring apparatuses.
FIG. 5 shows a perspective view of a third embodiment. In a non-contact sensor 20 , as in the case of FIG. 2 , a coherent light source 21 such as a laser diode, a collimator lens 22 , a non-polarizing beam splitter 23 and an optical-type probe-like polarizing prism 24 are disposed in succession, and the probe-like polarizing prism 24 has a polarizing beam splitter surface 24 a and a reference mirror surface 24 b, and a slider side 25 which is a non-measuring region is disposed on the front surface of the probe-like polarizing prism 24 in the direction of reflection of the polarizing surface 24 a.
A quarter wavelength plate 41 , an aperture plate 42 , a four-division diffraction grating plate 43 such as a hounds-tooth-checkered phase diffraction grating, a polarizing plate mask 44 having four gratings 44 a – 44 d formed on a substrate with their arrangement azimuths shifted by 45°, and a four-division light receiving element 45 having four areas 45 a – 45 d are arranged in succession in the direction of reflection of the non-polarizing beam splitter 23 .
During measurement, a divergent light L from the coherent light source 21 , as in the case of FIG. 2 , is divided into a transmitted light and a reflected light on the polarizing beam splitter surface 24 a of the probe-like polarizing prism 24 . S-polarized light reflected by the polarizing surface 24 a emerges from the probe-like polarizing prism 24 toward the slider side 25 , is reflected by the slider side 25 , and is returned to the polarizing surface 24 a of the probe-like polarizing prism 24 . On the other hand, P-polarized light transmitted through the polarizing surface 24 a is likewise returned to the polarizing surface 24 a.
These two polarized lights are combined together on the polarizing surface 24 a of the probe-like polarizing prism 24 , and become the bright-dark signal of an interference light beam by a polarizing interference optical system which will be described later. When the distance between the probe-like polarizing prism 24 and the slider side 25 changes, the difference between the lengths of the forward and backward optical paths of the two light beams separated by the polarizing surface 24 a becomes integer times as great as the wavelength of the coherent light source 21 , whereafter the bright and dark thereof change.
This change in the bright and dark is converted into an electrical signal by the light receiving element 45 , and as in the case of FIG. 2 , any change in the distance can be detected with high resolving power.
FIG. 6 shows a method of producing the 90° phase difference bright-dark signal of four phases described above, and at the stage whereat the two light beams emerge from the probe-like polarizing prism 24 , the two light beams are linearly polarized light beams of which the wave fronts overlap each other, but are orthogonal to each other, and do not interfere with each other to become a bright-dark signal. These are reflected by the non-polarizing beam splitter 23 , are transmitted through the quarter wavelength plate 41 and are converted into oppositely directed circularly polarized lights, and their vector-combined wave fronts become a linearly polarized light. Also, the direction of the polarized wave front of the linearly polarized light depends on the phase difference between the two light beams, and when the phase shifts by 360° between the two light beams, the polarized wave front rotates by 180°.
This linearly polarized light beam of which the polarized wave front rotates passes through an aperture in the aperture plate 42 and is amplitude divided into equivalent linearly polarized light beams by the four-division diffraction grating plate 43 . At this time, these four light beams separate from one another with the signal in a state in which only the intensities thereof are reduced by the division, and enter the polarizing plate mask 44 disposed in an appropriate space.
This polarizing plate mask 44 functions as an optical polarizing plate and can therefore be freely designed when it is formed in advance on a glass plate by the photolithographic process or the like. In the present embodiment, in order to obtain a four-phase bright-dark signal, there is required an interference signal of which the bright and dark phases shift by 90° each and therefore, metal grating lines are formed with their arrangement azimuths shifted by 45° from one another in each of areas through which the four light beams are transmitted. Also, the pitch of the grating lines is made sufficiently smaller than the wavelength of the coherent light source.
When the rotating linearly polarized light is orthogonal to the grating lines and when it coincides with the grating lines, the transmitted light becomes maximum and becomes minimum, respectively, and therefore, phase difference signals differing in the timing of bright and dark from one another are obtained in the four areas.
In the present embodiment, the quarter wavelength plate 41 , the aperture plate 42 , the four-division diffraction grating plate 43 , the polarizing plate mask 44 and the four-division light receiving elements 45 a – 45 d are simply disposed in an orderly way and therefore, the apparatus can be very simply and compactly constructed and the phase difference is settled highly accurately.
The present embodiment can be applied to a grating interference-type encoder in which a coherent light beam divided into two is applied to diffraction gratings moved relative to each other and diffracted lights of different orders are taken out to thereby produce an interference signal. It can also be applied to other popular grating interference-type encoders and interference measuring apparatuses.
As described above, the above-described interference-type measuring apparatus and grating interference-type encoder can realize an optical system very simply and compactly, and can collectively detect a plurality of stable phase difference signals and can effect highly accurate measurement.
Also, the above-described optical apparatus can realize such a measuring apparatus.
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Interference measuring apparatus for detecting a plurality of different interference phase signals. The apparatus has a light dividing member for dividing linearly polarized light beams superposed one upon another into a plurality of light beams. The apparatus also includes a light transmitting member with a plurality of light passing portions having different light transmitting properties in conformity with the incidence positions of the plurality of light beams divided by the light dividing member. In addition, the apparatus has a polarizing plate to receive the plurality of light beams that passed through the light transmitting member.
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FIELD OF THE INVENTION
[0001] The present invention relates generally to optical networking, and more particularly, to devices, systems and methods to improving the assignment of colors (wavelengths) on individual optical routes. This is accomplished by the use of an Integer Linear Programming model with the main objective of minimizing color change-over in mid route, thus reducing the need for costly Optical-Electrical-Optical devices which execute color change-over.
BACKGROUND OF THE INVENTION
[0002] The use of telecommunications networks and associated Network Access Devices (NADs) has increased dramatically over the last 20 years. We increasingly rely on network accessibility for voice, data and video communication, now integral to personal, government, business, education, health and safety communications.
[0003] In communication networks, a node is an active electronic device that is attached to a network, and is capable of sending, receiving, or forwarding information over a communications channel. A node is a connection point, either a redistribution point or a communication endpoint. In network theory, the term node may refer a point in a network topology where data links may intersect or branch.
[0004] A data link is the means of connecting one location to another for the purpose of transmitting and receiving digital information. It can also refer to a set of electronic assemblies, consisting of a transmitter and a receiver and the interconnecting data telecommunication circuit. Links are governed by a link protocol enabling digital data to be transferred from a data source to a data destination.
[0005] Network topology is the study of the arrangement or mapping of the network elements (links, nodes, etc.) of a network, comprised of the physical (real) and logical (virtual) interconnections between nodes. Local Area Networks (LANs) and Wide Area Networks (WANs) are examples of networks that exhibit both a physical topology and a logical topology. Any given node in a network will have one or more links to one or more other nodes in the network. Mapping of the links and nodes onto a graph results in a geometrical shape that determines the physical topology of the network. Similarly, the mapping of the flow of data between the nodes in the network determines the logical topology of the network. The physical and logical topologies may be identical in any particular network but they also may be different.
[0006] High performance and feature-rich communications in a “converged Internet Protocol” environment may in a single service include private intranet, voice, video, Internet, and business partner services. Rapid advances in optical communications technology and devices in terms of performance, reliability and cost over the last decade have enabled the deployment of optically routed Wavelength Division Multiplexing (WDM) networks which can be used to create high capacity nationwide and global broadband networks. In these networks, optical signals can flow end-to-end between users, many times without being converted to electrical signals at the network switches. They can offer large bandwidth, simple cross-connecting of high bit-rate streams, signal format and bit rate independent clear channels, equipment and operational savings, as well as maximum flexibility.
[0007] Optical networking provides the inter- and intra-transport capabilities for Access, Metropolitan and Global networks. These networks are composed of nodes and links, as described above. The links correspond to DWDM (Dense Wave Division Multiplexing) systems with multiple optical signals, also called Colors, Wavelengths or Channels. As used herein, color may be used to refer to wavelengths of visible, infrared or ultraviolet light. Multiplexing technology continues to evolve while current methods allow up to 80 discrete colors on a single pair of fibers. Nodes may be equipped with Optical Cross Connect devices where de-multiplexed optical signals are converted from the optical domain to the electronic domain, switched, converted back to the optical domain and multiplexed optically. This Optical-Electrical-Optical (OEO) function serves two purposes: switching and regeneration of the attenuated optical signals. In contrast Optical Switches operate optically so that the OEO function needed for regeneration of the signal and possibly for changing wavelength is performed before and/or after the optical switching function. Essentially, the optical switch serves as an automated optical patch panel. Also at a node, a Reconfigurable Optical Add/Drop Multiplexer (ROADM) in conjunction with transponders may be used to add/drop/switch channels optically.
[0008] Links equipped with DWDM systems require optical signal amplification every 100-150 kilometers and optical signal regeneration every 1000-1500 kilometers. With DWDM systems, all the optical signals can be amplified simultaneously, without de-multiplexing, while regeneration must be performed on the de-multiplexed optical signals individually.
[0009] It would therefore be desirable to develop a system, device and method to improve the assignment of colors (wavelengths) on individual optical routes. By utilizing an Integer Linear Programming model with the main objective of minimizing color change-over in mid route, the need for costly. Optical Cross Connect devices known as Optical-Electrical-Optical devices can be significantly reduced. To the inventors' knowledge, no such system or method currently exists.
SUMMARY OF THE INVENTION
[0010] In accordance with a first aspect of the present invention, a method is provided for assigning colors to WL demands for transmitting multiple optical signals in an optical network between originating nodes and terminating nodes. The optical network comprises a plurality of nodes interconnected by a plurality of links, the links each being capable of transmitting a respective predetermined maximum number of separate optical signals using separate colors.
[0011] In the method, a mathematical model is formulated representing the optical network and the WL demands. An objective function of the model is minimized, the objective function representing a total cost of the optical network as a function of the assignment of colors. The objective function includes a sum of at least the following quantities: a weighted summation of distances transmitted in each color in the network; a weighted count of each color in each link in each route, and a weighted count of each color in each route, whereby color changeovers on routes are penalized; and a weighted count of nodes traversed by each route, whereby routes with larger numbers of nodes are penalized. Colors are assigned to the WL demands whereby the objective function is minimized.
[0012] Another embodiment of the invention is a computer-usable medium having computer readable instructions stored thereon for execution by a processor to perform a method for identifying color channels for assignment to multiple optical signals in an optical network. The signals are transmitted over required routes between originating nodes and terminating nodes. The optical network comprises a plurality of nodes interconnected by a plurality of links, the links each being capable of transmitting a respective predetermined maximum number of separate optical signals on separate color channels.
[0013] The method comprises formulating a mathematical model representing the optical network and the required routes; and minimizing an objective function of the model, the objective function representing a total cost of the optical network as a function of the assignment of color channels, the objective function including a sum of at least the following quantities: a weighted summation of distances transmitted in each color channel in the network; a weighted count of each color in each link in each route, and a weighted count of each color in each route, whereby color changeovers on routes are penalized; and a weighted count of nodes traversed by each route, whereby routes with larger numbers of nodes are penalized. Color channels are identified for assignment to the multiple optical signals such that the objective function is minimized.
[0014] In yet another embodiment of the invention, a method is provided for transmitting multiple optical signals over separate color channels in an optical network to satisfy transmission demands between originating nodes and terminating nodes. The optical network comprises a plurality of nodes interconnected by a plurality of links, each of the links being capable of transmitting a respective predetermined maximum number of separate color channels.
[0015] The method comprises the steps of partitioning the nodes into geographic clusters whereby all inter-cluster routes have a length less than a maximum regeneration distance; selecting at least one node in each cluster to contain optical cross connect devices having optical-electric-optical converters (OEOs); and routing longer intra-cluster demands via the selected OEO nodes, while ignoring the predetermined maximum number of separate color channels. For each cluster, a mathematical model is formulated representing the optical network, the model further representing all intra-cluster demands and those portions of inter-cluster demands from their source nodes to an OEO node.
[0016] An objective function of the model is minimized, the objective function representing a total cost of the optical network as a function of the assignment of color channels. Color channels are assigned according to the minimized objective function; and color channels are assigned to all leftover inter-cluster portions of the demands between their respective OEO nodes.
[0017] These aspects of the invention and further advantages thereof will become apparent to those skilled in the art as the present invention is described with particular reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a schematic of a network including nodes and links in accordance with an aspect of the present invention;
[0019] FIG. 2 shows an exemplary AMPL model, Lambda.mod, to optimize the network of FIG. 1 in accordance with the present invention;
[0020] FIG. 3 shows the data, Lambda.dat, and demands for the exemplary AMPL model of FIG. 1 in accordance with the present invention;
[0021] FIG. 4 shows the run script, Lambda.run, for the exemplary AMPL model of FIG. 1 in accordance with the present invention;
[0022] FIG. 5 shows an output file, Lambda.out, for the exemplary AMPL model of FIG. 1 in accordance with the present invention;
[0023] FIG. 6 shows a partial solution set for color assignment and routes for the exemplary AMPL model of FIG. 1 in accordance with the present invention;
[0024] FIG. 7 shows the full solution set for routes only, without color assignment details, and unused links for the exemplary AMPL model of FIG. 1 in accordance with the present invention;
[0025] FIG. 8 shows an exemplary network to illustrate forced color change-over in mid route in accordance with an aspect of the present invention;
[0026] FIG. 9 shows the output of the AMPL model to optimize the network of FIG. 8 in accordance with the present invention; and
[0027] FIG. 10 is a flow diagram of an exemplary method in accordance with an aspect of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0028] Embodiments of the invention will be described with reference to the accompanying drawing figures wherein like numbers represent like elements throughout. Before embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of the examples set forth in the following description or illustrated in the figures. The invention is capable of other embodiments and of being practiced or carried out in a variety of applications and in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein are meant to encompass the items listed thereafter and equivalents thereof as well as additional items.
[0029] The present invention describes an optical communications network optimization model to assign colors to routes carrying optical signal demands (traffic) in order to minimize the need to change colors in mid-route. There are several variants of the model, a ‘static’ one in which all demands are given input, a ‘dynamic’ one in which additional demands need assignments without (or minimally) rearranging current assignments, and a ‘restoration’ one in which a link or some colors on a link fail and the disrupted demands need to be reassigned routes and colors, again without (or minimally) rearranging existing functional assignments. The model provides a basic construct which may be modified by removing irrelevant variables or constraint sets, or extended by building upon the basic model, as needed.
[0030] The present invention pertains mainly to modeling optical communications network traffic in an optical mesh network, and has much in common with the problem of finding diverse routes in a network. In this regard, finding link-disjoint routes for demands are considered. These routes are assigned colors but they may cross at nodes where routes intersect, a function provided by an Optical Switch.
[0031] A route ‘r’ is defined by binary variables x[l, r] where the ‘l’-s identify the links that the route ‘r’ traverses. To solve for the values of x[l, r], a special case of the standard single-commodity capacitated network-flow approach in an arc-node formulation is used. A directed link ‘l’ is represented on a graph as an arc from node ‘i’ to node ‘j’. Associated with a link is a cost per unit flow c[l], (say distance or latency) and a flow variable x[r, l]. Associated with every route ‘r’, is a source node ‘a’ with an in-flow of one unit and destination node ‘z’ with out-flow of one unit. Nodes that are neither a source nor a destination conserve flows. A Linear Programming model that minimizes Σx[l,r]*c[l] subject to conservation of flow equations in an arc-node formulation will result in x[l, r]={0, 1} defining the shortest path for ‘r’ from ‘a’ to ‘z’. Additionally, constraints will be added to the formulation to accommodate the need to assign colors to each route. Furthermore, variables and constraint sets are added to solve several closely related problems. Finally, weights are then used in the objective function to direct the solution.
[0032] FIG. 1 is a schematic 100 of a network comprising nodes and links in accordance with an aspect of the present invention. The network 100 consists of 10 nodes, denoted by numbers within boxes and 24 links, denoted by numbers on bi-directional arrows. The links connect the nodes. For example, bi-directional link number 13 connects node 4 with node 6 , and bi-directional link number 5 connects node 2 with node 4 .
[0033] For modeling purposes each link of FIG. 1 is represented as two uni-directional links, thus the 24 bi-directional links end up represented as 48 unidirectional ones. Bi-directional link 13 is associated with the unidirectional link 13 (and ordered node-pair 4 - 6 ) and with the unidirectional link 37 (=13+24) and with the ordered node-pair 6 - 4 . Similarly, unidirectional link 2 is associated with node pair 1 - 10 and unidirectional link 26 (=2+24) with node pair 10 - 1 . A link corresponds to a DWDM system connecting the pair of nodes.
[0034] DWDM systems typically consist of two directional streams of bits on two fibers; however, some systems may use only one fiber for both directions. As related to the model, the two directions associated with each link are required to help determine routes and they do not correspond to the directions of the bits.
[0035] The model of the present invention as described with reference to FIG. 1 assumes that all DWDM systems are identical and have identical channel capacity (i.e. have the same number of colors). The model can be extended without departing from the present invention to accommodate DWDMs with a varying number of colors and can accommodate parallel systems between pairs of nodes. Demands are given in units of wavelength between pairs of nodes. The model will determine a route for each demand and assign colors one per unit of demand, subject to availability of colors while minimizing color changeover mid route.
[0036] In what follows, the model will be defined using the syntax of AMPL (A Mathematical Programming Language), as is known by those skilled in the art. Other programming languages may be used. First the input data will be defined, followed by the variables, then the set of constraints and finally the objective function.
[0037] Data
[0038] The number of nodes in the network is defined, together with the set of nodes and their numerical identities.
[0000]
=======
param NUMNODES ;
# number of nodes
set NN := 1..NUMNODES ;
# set of nodes
param NODES {n in NN};
# node IDs
=======
[0039] The data associated with the links are defined in the uni-directional manner described earlier. The first set from 1 to NUMLINKS have a forward direction and the ones from NUMLINKS+1 to 2*NUMLINKS the associated backwards direction. Whenever referring to bidirectional links, the first set only will be used. Thus, link 1 and link 1 +NUMLINKS represent the two directions of link 1 . Note that the links and their associated data may have the same end-nodes provided they have distinct link numbers; that is, multiple DWDM systems between same pairs of end-nodes must have distinct link numbers in the set L.
[0000]
=======
param NUMLINKS ;
param NUMLINKS2 := 2*NUMLINKS;
set L := 1..NUMLINKS;
# set of links a to z
set L2 := 1..NUMLINKS2;
# set of links a to z and z to a
=======
[0040] The next set of data is associated with each directed link. That data includes the identities of its originating node, terminating node and its distance.
[0041] The number of allowed colors per link is then defined in L (DWDM) and their identity in the set CC.
[0000]
=======
param LO {l in L2};
# links' originating nodes
param LD {l in L2};
# links' destination nodes
param DIST {l in L2};
# distance of each link
param NUMCOLORS;
# number of colors (wavelengths) assumed the same for each link
set CC := 1..NUMCOLORS;
# set of colors
========
[0042] Data for the requested routes is then specified, including the number of routes, their end-nodes and associated wavelength requirement (in units of wavelength). The model attempts to assign a color to each unit and all colors will follow the same route for a specific demand requirement. Note that one could request several routes with the same end node-pairs. In this case the model will attempt to generate several routes possibly distinct, while minimizing the total distance.
[0043] For each node, the minimum number of via routes the node should accommodate and the maximum number of total wavelengths (WLs) the node can accommodate as via capacity are specified. These parameters, as used in the following constraints, provide a way to designate some nodes as OEO nodes.
[0044] The MAXHOP parameters can be used to constrain the number of hops on a route and the Wx parameters are used as weights for different terms in the objective function.
[0000]
==============
param NUMR ;
# number of demand requirements
set R := 1..NUMR;
param RO {r in R};
# set of a requirements’ originating
end point
param RD {r in R};
# set of a requirements’ destination
end points
param WL {r in R};
# number of wavelength demand
requirement (in lambda units)
param NUMVIA {n in NN};
# forcing routes via a switch for OEO
functionality
param NUMVIACAP {n in NN};
# constraining total WLs via a switch
param MAXHOP ;
# max number of hops allowed on
route
param W1;
# weights for terms in the objective
function
param W2;
param W3;
param W4;
param W5;
==========
[0045] Variables
[0046] The x variables, when set to 1 by the program for route r and link 1 , define the links that make the route. The auxiliary variables uu and vv will be used to force consistency of color along a route. The variable zz indicates the use of a color in the network. The variable via when set to 1 indicates that route r traverses node n. This will be explained later when describing the constraint sets and how it is being used.
[0000]
==========
var x{l in L2, r in R}, binary;
# =1 if route r uses link l, 0
otherwise
var uu{ r in R, l in L2, c in CC}, binary;
# color assignment variable
var vv{ r in R, c in CC}, binary;
# upper bound variable to
force color consistency
Var zz{c in CC) >=0, integer;
# color use indicator
var via{n in NN, r in R} >=0;
# computed variable if =1
then # route r traverses node n
==========
[0047] Constraints
[0048] The first three sets of constraints are structured to define routes. For each requested route r, the traditional set node flow-conservation equations with a balance of {+1, −1, 0} depending on whether the node is an originating one, terminating one or either flow-thru node or non-participating one for the route. This formulation alleviates the need to pre calculate large sets of potential routes.
[0049] The 4 th set of constraints is based on the third set. The variable via[n,r] is computed and it takes a value of 1 if route r passes via node n, or is 0 otherwise. This variable can be used to force a route to use or avoid a set of particular nodes to be defined in the input data file.
[0050] The 5 th and 6 th sets of constraints force a minimum of NUMVIA[n] routes to pass thru node n not to exceed a total of NUMVIACAP[n} units of WLs.
[0051] An optional 7 th set of constraints limits the total number of hops on each route, for example to no more than MAXHOP. Slight modifications of the 7 th set of constraints can accommodate limits on route miles or maximum permitted latency for each demand (route). This constraint may be used to reflect technological limitations in the network.
[0000]
================
subject to node_conserve1 {n in NN, r in R : n=RD[r]}:
sum {l in L2, m in NN : n=LO[l] && m=LD[l]} x[l,r]
− sum {l in L2, m in NN : n=LD[l] && m=LO[l]} x[l,r] = −1;
subject to node_conserve2 {n in NN, r in R : n=RO[r]}:
sum {l in L2, m in NN : n=LO[l] && m=LD[l]} x[l,r]
− sum {l in L2, m in NN : n=LD[l] && m=LO[l]} x[l,r] = 1;
subject to node_conserve3 {n in NN, r in R : n <> RO[r] && n <>
RD[r]}:
sum {l in L2, m in NN : n=LO[l] && m=LD[l]} x[l,r]
− sum {l in L2, m in NN : n=LD[l] && m=LO[l]} x[l,r] = 0 ;
subject to flowthru {n in NN, r in R : n <> RO[r] && n <> RD[r]}:
sum {l in L2, m in NN : n=LO[l] && m=LD[l]} x[l,r]
+ sum {l in L2, m in NN : n=LD[l] && m=LO[l]} x[l,r] =
2*via[n,r] ;
subject to total_via{n in NN}:
sum {r in R} via[n,r] >= NUMVIA[n];
subject to node_via_cap{n in NN}:
sum {r in R} via[n,r] * WL[r] <= NUMVIACAP[n];
subject to maxhop {r in R}:
sum {l in L2} x[l,r] <= MAXHOP;
=================
[0052] The following set of equations assures that capacity of each link is not exceeded. Notice that each demand is associated with a route and does not get split across routes. If splitting is allowed then each wavelength request is for one unit (WL[r]=1) and the model still applies.
[0000]
========================
# defined for nondirectional links
subject to capacity_cons {l in L}:
sum {r in R} (x[l,r] +x[l+NUMLINKS,r])*WL[r] <= NUMCOLORS
========================
[0053] The set of inequalities that force contiguities of colors along the routes follows. The variable uu[r,l,c] is binary and assigns a specific color ‘c’ on link ‘l’ when used by route ‘r’. The first set of constraints, ‘uu_color’, assures proper distribution of colors for each channel in the demand set of route ‘r’. The second set of constraints, ‘vv_color’, counts the number of colors that has been used up by different links on the same route. These variables uu[r,l,c] and vv[r,c] will be used in the objective function to force, if possible, an assignment of one color per route by associating a weight with vv[r,c]. Notice that when vv[r,c]=1, route ‘r’ is assigned color ‘c’. When vv[r,c]=2, two colors are associated with route ‘r’, but the number of color changeovers at nodes on the route could be ≧1. For example, a route with 5 links that have been assigned 2 colors (1 and 2) could have at most 4 changeovers (1, 2, 1, 2, 1).
[0000]
========================
# forcing contiguous color
# distinct colors are assigned by uu[r,l,c]
# maintaining continuity of colors using vv[r,c]
# only one color can be assigned per link (forward and backwards
direction
# counting the number of colors used in the network
subject to uu_color {l in L2, r in R}:
x[l,r]*WL[r] = sum {c in CC} uu[r,l,c];
subject to vv_color { r in R, l in L2, c in CC}:
uu[r,l,c] <= vv[r,c];
subject to wl_color { l in L , c in CC}:
sum {r in R} (uu[r,l,c]+uu[r,l+NUMLINKS,c]) <=1;
subject to zz_color ( r in R, l in L, c in CC }:
uu[r,l,c] <= zz[c];
========================
[0054] The last set of constraints indicates the use of a color ‘c’ and the variable zz[c] and its weight W 5 may be used in the objective function to force a solution with a minimum number of colors in the network.
[0055] Objective Function
[0056] In the following objective function, the first summation represents the total wavelength miles. The second and third terms use penalties to minimize color changeovers on routes. The fourth term minimizes the number of nodes passed by the routes. The fifth term may be used to minimize color use in the network.
[0057] minimize color_cost:
[0000]
sum
{
r
in
R
,
1
in
L
}
W
1
*
WL
[
r
]
*
DIST
[
l
]
*
(
x
[
1
,
r
]
+
x
[
1
+
NUMLINKS
,
r
]
)
+
sum
{
r
in
R
,
l
in
L
2
,
c
in
CC
}
W
2
*
uu
[
r
,
l
,
c
]
+
sum
{
r
in
R
,
c
in
CC
}
W
3
*
vv
[
r
,
c
]
+
sum
{
n
in
NN
,
r
in
R
}
W
4
*
via
[
n
,
r
]
+
sum
(
c
in
CC
}
W
5
*
zz
[
c
]
;
[0058] Scalability
[0059] The model can grow very large in terms of the number of variables and constraints.
[0060] Number of variables:
[0000]
x[l,r]
2*L*R
uu[r,l,c]
R*2*L*C
vv[l,c]
2*L*C
zz[c]
C
via[n,r]
N*R
[0061] Number of constraints:
[0000]
node_conserve
N*R
flowthru
N*R
total_via
N
total_via_cap
N
max_hop
R
uu_color
2*L*R
vv_color
R*2*L*C
wl_color
L*C
zz_color
R*L*C
color_cost
1
[0062] The model produced results quickly for a small sample network (such as the example of FIG. 1 , where N=10, L=24, R=8 and C=4), with larger and more complex networks having longer run times.
[0063] Some additional measures may be required if the underlying network gets to be orders of magnitude larger, such as:
a) use of a faster multi-processing machine; b) processing routing requests only off-line for planning purposes; c) terminating a program run before optimality is proven by the branch and bound method; and d) reverting to pure LP and integerize fractional variables with a post-processing heuristics.
[0068] The following describes two scenarios to improving the assignment of colors (wavelengths) on individual optical routes in accordance with aspects of the present invention.
Example 1
Optimization of the FIG. 1 Network
[0069] One example of optimization of color use in the network of FIG. 1 is presented in FIGS. 2-5 . A listing of the AMPL model, Lambda.mod 200 , is shown in FIG. 2 . A listing of the data for the network of FIG. 1 , Lambda.dat 300 , including the demands for 8 routes, is shown in FIG. 3 . A listing of a run script, Lambda.run 400 , is shown in FIG. 4 . An output file, Lambda.out 500 , is shown in FIG. 5 . This optimization was solved with virtually no delay in 1938 Mixed Integer Program (MIP) simplex iterations and 0 branch-and-bound nodes.
[0070] The following is the output of a previous run that had no zz variables and no fifth term in the objective function. That run was solved with virtually no delay in 2075 MIP simplex iterations and 10 branch-and-bound nodes. FIG. 6 shows a partial color assignment solution set 600 for the exemplary AMPL model run.
[0071] For this optimization solution shown in FIG. 6 , the demands are as follows:
[0000]
param:
RO
RD
WL :=
1
1
10
4
2
10
1
3
3
6
3
4
4
2
8
4
5
9
4
1
6
10
1
3
7
6
3
2
8
2
8
1
;
[0072] From the above table, demand number 1 from node 1 to node 10 is for 4 units and demand number 2 from node 10 to node 1 is for 3 units. Demand number 6 from node 10 to node 1 is for 3 units. These demands will follow 3 routes, link-capacities permitting.
[0073] For this optimization solution, the output matrix is as follows:
[0000]
vv[r,c]
[*,*]
:
1
2
3
4
:=
1
1
1
1
1
2
.
1
1
1
3
1
1
1
1
4
1
1
1
1
5
1
.
.
.
6
1
1
.
1
7
1
1
.
.
8
.
.
1
.
;
[0074] The output matrix indicates that demand number 1 for 4 units was assigned colors 1 , 2 , 3 and 4 on its route (no splitting assumption), and demand number 2 for 3 units was assigned colors 2 , 3 and 4 on a separate route. Since no entry in this matrix is greater than 1, it is concluded that a solution was found without a need to switch colors in mid-route.
[0075] The following matrices indicate the assignment of colors on the links for each unit of WL by route.
[0000]
uu[r,l,c]
[*,*,1]
(tr)
:
1
3
4
5
6
7
:=
2
1
.
.
.
.
.
6
.
.
1
.
.
.
15
.
.
1
.
.
.
17
.
1
.
.
.
.
18
.
.
.
.
.
1
23
.
.
.
.
.
1
27
.
.
.
.
1
.
29
.
.
.
.
1
.
34
.
1
.
.
.
.
35
.
.
.
1
.
.
37
.
.
.
.
1
.
40
.
1
.
.
.
.
44
.
.
.
.
.
1
48
.
.
.
.
1
.
[*,*,2]
(tr)
:
1
2
3
4
6
7
:=
2
1
.
.
.
.
.
6
.
.
.
1
.
.
15
.
.
.
1
.
.
17
.
.
1
.
.
.
18
.
.
.
.
.
1
21
.
1
.
.
.
.
23
.
.
.
.
.
1
25
.
1
.
.
.
.
27
.
.
.
.
1
.
29
.
.
.
.
1
.
34
.
.
1
.
.
.
35
.
1
.
.
.
.
37
.
.
.
.
1
.
40
.
.
1
.
.
.
44
.
.
.
.
.
1
48
.
.
.
.
1
.
[*,*,3]
(tr)
:
1
2
3
4
8
:=
2
1
.
.
.
.
5
.
.
.
.
1
6
.
.
.
1
.
13
.
.
.
.
1
15
.
.
.
1
.
17
.
.
1
.
.
18
.
.
.
.
1
21
.
1
.
.
.
25
.
1
.
.
.
34
.
.
1
.
.
35
.
1
.
.
.
40
.
.
1
.
.
[*,*,4]
(tr)
:
1
2
3
4
6
:=
2
1
.
.
.
.
6
.
.
.
1
.
15
.
.
.
1
.
17
.
.
1
.
.
21
.
1
.
.
.
25
.
1
.
.
.
27
.
.
.
.
1
29
.
.
.
.
1
34
.
.
1
.
.
35
.
1
.
.
.
37
.
.
.
.
1
40
.
.
1
.
.
48
.
.
.
.
1
;
[0076] Routes satisfying four of the eight demands are shown in FIG. 6 . Link 2 was used for the first route and consumed all 4 colors for demand number 1 from node 1 to node 10 . Colors 2 , 3 and 4 were used for demand number 2 (of three units) on the route composed of links 21 , 35 and 25 (that is 21 , 11 and 1 ) from node 10 to node 1 . Demand number 7 from node 6 to node 3 for two units was assigned colors 1 and 2 on the route composed of links 18 , 44 and 23 (that is 18 , 20 and 23 ). Demand number 6 again from node 10 to node 1 consumes colors 1 , 2 and 4 on links 48 , 37 , 29 , and 27 ( 24 , 13 , 5 and 3 ).
[0077] FIG. 7 shows the full solution set 700 for all eight demands for the exemplary AMPL model. The lines correspond to the routes only and not to the assignment of colors to WL's. The diagram of FIG. 7 explains what seems to be inefficient routing of demands 2 , 6 and 7 . Each route (demand) represents several WL's. There is clearly a mismatch between the demands and the link capacities. Longer routes may result from either lack of capacities or from the requirement for color contiguity of WL.
[0078] The matrix via[n,r]:
[0000]
via[n,r]
[*,*]
:
1
2
3
4
5
6
7
8
:=
1
0
0
0
0
0
0
0
0
2
0
0
0
0
0
1
0
0
3
0
0
0
0
0
0
0
0
4
0
1
0
0
0
1
0
1
5
0
0
1
1
0
0
0
0
6
0
0
0
0
0
1
0
1
7
0
0
1
0
0
0
0
0
8
0
0
0
0
0
0
1
0
9
0
1
0
0
0
0
1
0
10
0
0
0
0
0
0
0
0
;
[0079] From the above matrix, demand number 1 is routed directly without via nodes. Demand number 2 passes via nodes 4 and 9 ; demand number 6 via nodes 2 , 4 and 6 ; and demand number 7 passes via nodes 8 and 9 . These four demands and corresponding individually assigned colors were illustrated in detail in FIG. 6 .
Example 2
Forced Color Change-Over in Mid Route
[0080] To illustrate forced color changes on a route, a small example is presented in FIGS. 8 and 9 . FIG. 8 shows an exemplary network 800 to illustrate forced color change-over in mid route in accordance with an aspect of the present invention. The exemplary network consists of 4 nodes, 6 bi-directional links, 3 demands for 1 unit of wavelength each, with every link able to accommodate 2 colors, as follows:
[0000]
=======
param NUMNODES :=4;
param NUMLINKS :=3;
param :LO LD DIST:=
1
1
2
100
2
1
3
100
3
1
4
100
4
2
3
140
{close oversize brace}
Forward
5
2
4
140
6
3
4
140
7
2
1
100
8
3
1
100
9
4
1
100
10
3
2
140
{close oversize brace}
Backward
11
4
2
140
12
4
3
140
param NUMCOLORS :=2;
param NUMR :=3
param : RO RD WL :=
1
2
3
1
2
2
4
1
3
3
4
1;
param: NUMVIA NUMVIACAP:=
1
3
3
2
0
3
3
0
3
4
0
3
=======
[0081] The output of the model for example 2 is shown in FIG. 9 , and shown below are matrices uu[r,l,c] and via[n,r].
[0000]
uu[r,l,c] :=
1
2
2
1
1
7
2
1
2
3
2
1
2
7
1
1
3
3
1
1
3
8
1
1
via[n,r] :=
1
1
1
1
2
1
1
3
1
2
1
0
2
2
0
2
3
0
3
1
0
3
2
0
3
3
0
4
1
0
4
2
0
4
3
0
[0082] The matrix uu[r,l,c] shows that demand route number 1 (element 910 of FIG. 9 ) was assigned color 2 on both link 2 920 and link 1 930 . Demand route number 3 (element 940 ) was assigned color 1 on both link 2 950 and link 3 960 . Lastly, demand route 2 970 was assigned color 2 on link 3 980 and color 1 on link 1 990 . A color changeover was executed in node 1 for demand route 2 970 . The output matrix via[n,r] shows that all three demands were forced via node 1 and nodes 2 , 3 and 4 have no via routes.
[0083] FIG. 10 is a flow diagram of an exemplary method 1000 in accordance with one aspect of the present invention. In step 1010 a mathematical model is formulated representing the optical network and the WL demands;
[0084] An objective function of the model is then minimized (step 1020 ). The objective function represents a total cost of the optical network as a function of the assignment of color channels. In a preferred embodiment, the objective function includes a sum of at least the following quantities: a weighted summation of distances transmitted in each color channel in the network; a weighted count of each color in each link in each route, and a weighted count of each color in each route, whereby color changeovers on routes are penalized; and a weighted count of nodes traversed by each route, whereby routes with larger numbers of nodes are penalized.
[0085] Colors are assigned (step 1030 ) to the WL demands whereby the objective function is minimized.
[0086] Variants and Extensions
[0087] As mentioned earlier, the model is basic but may be extended in several directions. Assumptions are made, for example, that the channel units are fixed (e.g. OC48) but the model can be extended to DWDMs having link-dependent numbers of channels.
[0088] If a change in color is required, the model assumes it can take place in any node. With added complexity one can define two types of nodes: one type can provide changing of colors functionality and the other does not. The structure of the set of hop constraints can be used to set bounds on route mileage and a bound on latency.
[0089] Extensions already discussed include requirements that force routes to traverse designated OEO nodes or minimize total color usage in the network.
[0090] One benefit of the present invention is that the model minimizes the requirement for costly OEO devices when amplification suffices (within the limitation of distance). Furthermore, it provides for a structure so that additional extensions and enhancements could be added as needed or technology changes make possible or feasible. For example, one could 1 ) partition the nodes of a network into geographical clusters that assure that all intra-cluster routes satisfy the regeneration distance constraints, 2) select say 2 nodes (for reliability) from each such cluster as OEO nodes, 3) route all intra-cluster ‘long’ demands via the OEO nodes ignoring temporarily the color constraints 4 ) use the current model, a cluster at a time, to route the intra-cluster demands and the partial demands of the inter-cluster demands from their source nodes to the cluster's OEO node identified in (3), and 5) assign colors to all the leftover inter-cluster portions of the demands between their respective OEOs.
[0091] In the model of the present invention, all demands are given as input data while the output presents an optimal assignment of colors. This is a ‘static’ greenfield problem, as known by those skilled in the art. A “dynamic” version of the problem assumes that an assignment is already in place and there are new requests for some additional demands. In a ‘restoration’ version of the problem a link or some WL's on a link fail, thus the routes fail. In the content of the model of the present invention, for the ‘dynamic’ and ‘restoration’ cases, one can fix the variables x[l,r] and uu[r,l,c] at value l for the routes that that stay up and re-solve the model for the disrupted, new demands or the once that can be rearranged.
[0092] The foregoing detailed description is to be understood as being in every respect illustrative and exemplary, but not restrictive, and the scope of the invention disclosed herein is not to be determined from the description of the invention, but rather from the claims as interpreted according to the full breadth permitted by the patent laws. It is to be understood that the embodiments shown and described herein are only illustrative of the principles of the present invention and that various modifications may be implemented by those skilled in the art without departing from the scope and spirit of the invention.
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A model is provided for optimizing an optical network wherein single links carry multiple signals by using multiple color channels. The routes in the optimized network minimize mid-route color changeovers, reducing the number of nodes requiring optical-electric-optical signal conversion. In the model, the minimized objective function includes terms representing total color miles, terms penalizing changeovers, and terms representing total nodes passed by routes.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Benefit of Provisional Application 60/438,548 filed Jan. 6, 2003 is claimed
BACKGROUND OF THE INVENTION
[0002] This invention relates to curing methods for elastomers and to the compositions and articles prepared by such methods.
[0003] Elastomers can be vulcanized in a number of ways, for example with sulfur compounds or with organic peroxides. Sulfur vulcanization has the advantage of not being inhibited by oxygen at the surface of the article being molded, whereas organic peroxide cure methods have been limited to closed pressure molding (such as compression, transfer, and injection molding) because it is generally understood in the art that oxygen contacting the surface during molding reacts with the peroxy catalyst to cause hydroperoxy radicals which inhibit vulcanization and cause degradation of the resultant polymer. This results in tacky and/or partially cured elastomer surfaces. This is due to radicals in the polymer chain coupling with free oxygen to create hydroperoxy radicals. This hydroperoxy radical inhibits vulcanization and ultimately leads to degradation of the polymer. This phenomenon normally limits the production of peroxide-cured elastomers to molded goods. The three main types of molding are compression, transfer, and injection molding processes. All of these molding methods rely on an enclosed cavity for curing, and pressure to keep oxygen out of the system.
[0004] Typical cure mechanisms associated with sulfur vulcanization of elastomers are not normally inhibited by the presence of oxygen. This allows such sulfur cured elastomers to be cured in a wide variety of open surface methods in addition to the closed compression, transfer, and injection molding methods. Such open surface methods by which sulfur curing but not peroxide curing were practical in the prior art include: Open Hot Air Environment; Open Steam Environment; Open Salt Bath; and Open Sand Bath.
[0005] Although it is theoretically possible to peroxide-cure elastomers in an open-air environment by removing the oxygen from the curing environment by purging with nitrogen or another suitable material, such a method is unrealistic in commercial elastomer production since the curing environment is too large and would require an uneconomical supply of nitrogen to purge the cure area.
SUMMARY
[0006] It has been discovered that an organic peroxide-initiated elastomer composition comprising a metal carboxylate can be molded under open surface conditions to produce a tack free or low tack surface molding. The invention comprises the method of molding, the molding composition, the molding produced by the process, and molded articles prepared by the process.
DETAILED DESCRIPTION
[0007] Elastomers to which the invention is applicable are any which can be molded under open surface conditions using organic peroxide initiators. Examples of such elastomers include ethylene-propylene diene rubber (EPDM), nitrile rubber (NBR), polychloroprene (CR), hydrogenated NBR (HNBR), styrene-butadiene rubber (SBR), polybutadiene rubber (BR), ethylene-propylene copolymer (EPM), fluoroelastomers (FKM), silicone rubber (MQ, VMQ), acrylic rubber (ACM), Acrylonitrile-butadiene-styrene (ABS), polyethylene (PE), chlorosulfonated polyethylene (CSM), chlorinated polyethylene (CM) (also known as CPE), natural polyisoprene (NR), synthetic polyisoprene (IR), and ethylene-vinyl acetate (EVA). EPDM is the most typical elastomer presently used in this art.
[0008] Suitable organic peroxides are any of the ones which are used in the art of curing the elastomers. Examples include dicumyl peroxide, di-(t-butylperoxy)-diisopropylbenzene, 2, 5 dimethyl-2,5-di-(t-butyl-peroxy) hexane (DBPH), 2,5-dimethyl-2,5-Di-(t-butyl-peroxy)hexyne-3 (Varox 130 type), n-Butyl 4,4-Di(t-butylperoxy) valerate (Varox 230 type), and 1,1 bis-(t-butylperoxy)-3,3,5-trimethyl-cyclohexane (Varox 231 type).
[0009] The amounts of peroxide are also any of the amounts used in the art of peroxide-cured molding elastomers, usually about 0.1 to 10 percent, based on elastomer.
[0010] The composition can also include any cross-linking coagent. Some examples include trimethylol propane trimethacrylate (TMPTM), trimethylol propane triacrylate, triallyl cyanurate, bis maleimide, 1,2-vinyl polybutadiene; and the like.
[0011] The metal carboxylate is added by any means. Some examples include combining the carboxylate with the elastomer by conventional blending or pre-dissolving in a cross-linking coagent (typically in a concentration of about 5 to 25% by weight), and then adding the solution to the elastomer, for example in a ratio of about 2 to 20 parts by weight of the solution per 100 parts by weight of the elastomer.
[0012] Typical amounts of metal carboxylate compound are 0.1 to 10 parts by weight per hundred overall elastomer, peroxide, and metal carboxylate composition. Preferably 0.2 to 2.5 parts by weight of the metal carboxylate is used.
[0013] The metal compound can be any metal carboxylate, preferably C 2 to C 20 fatty acid, for example metal neodecanoate, metal proprionate, metal naptheneate, and/or metal octoate.
[0014] Suitable metals include, for example, cobalt, zirconium, manganese, zinc, iron, aluminum, and tin. Cobalt is the most preferred metal, and cobalt neodecanoate is the most preferred metal carboxylate. Mixtures of metal carboxylates are also suitable.
[0015] The curing conditions are any of those used in open surface molding of elastomers, for example open hot air, open steam, open salt bath, and open sand bath methods. While the novel compositions of the invention can be used in any molding method, the advantage of low tack to tack-free surfaces is an improvement most particularly applicable to open molding methods.
[0016] While not intending to be limited to any theory of operation, it is believed that incorporation of the metal compound in the peroxide-initiated elastomer formulation prevents oxygen from degrading the peroxy radicals on the elastomer surface.
EXAMPLES
[0017] In the following examples, all parts and percentages are by weight, unless otherwise indicated.
Example 1 (Comparative)
[0018] A formulation consisting of 100 parts EPDM elastomer (Dupont-Dow IP 4640 brand) was blended with 7.5 parts Dicumyl peroxide (Hercules DiCup 40 KE brand) and 5 parts Trimethylolpropane trimethacrylate (Sartomer SR 350 brand). The composition was mixed and molded under open air cure conditions at 330° F. for 40 minutes and press cured for 45 minutes at 330° F. The following properties were measured: degree of tack on cured plaques, tensile strength, elongation, and modulus. The results are reported in the table below.
Examples 2 and 3 (Invention)
[0019] Example 1 was repeated except using 0.25 parts cobalt neodecanoate in Ex. 2 and 0.5 parts in Ex. 3, with the results reported in the table below.
[0020] As can be seen from the results of the comparative testing, the moldings of the invention had no tack on their surfaces whereas the molding of the comparative example had a tacky surface.
TABLE EXAMPLE 1 2 3 Formulation EPDM 1 100 100 100 Dicumyl peroxide 2 7.5 7.5 7.5 Trimethylolpropane 5 4.75 4.5 trimethacrylate 3 Cobalt Neodecanoate 0.25 0.5 Mixing Cure Meter; ASTM D2084 ODR, 320° F. MH, in-lb 97.6 103.6 107.3 ML, in-lb 11.6 11.7 11.8 MH - ML, in-lb 86 91.9 95.5 Tc90, min 33.7 34.3 33.2 Ts2, min 1.25 1.27 1.26 Degree of flash tack tacky no tack no tack Plaques molded but not cured in carver press for 5 minutes @ 212° F. Open Air Cure @ 330° F. (min) 40 40 40 Degree of tack on cured plaque tacky no tack no tack Press Cure @ 330° F. (min) 45 45 45 Physicals (Ambient conditions) Tension; ASTM D412 Tensile Strength, lbf/in 2 285 330 330 Elongation, % 100 115 115 Modulus (100%), lbf/in 2 285 300 300
[0021] While the invention has been described and exemplified in sufficient detail to enable those skilled in the art to make and use it, other embodiments, alternatives, and modifications should become readily apparent without departing from the spirit and scope of the invention.
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An organic peroxide vulcanized elastomer having a tack free or low tack surface is prepared under open surface conditions by curing a composition comprising a solid elastomer, an organic peroxide initiator, and a metal carboxylate. The metal carboxylate may be dissolved in a cross-linking coagent and then blended with the elastomer prior to open surface curing. Examples of the open surface molding methods include hot air, steam, salt bath, and sand bath.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a mirror device for a vehicle.
[0003] 2. Description of the Related Art
[0004] Prior Art 1
[0005] In a mirror device for a vehicle, such as an electrically powered housable-type door mirror device, a mirror stay is fixed to a side of the vehicle body so as to extend in a substantially transverse direction from the vehicle, and a mirror main body portion is supported by the mirror stay such that the mirror main body can swing between a housed position and a position for viewing. This type of conventional door mirror device 100 is illustrated in FIGS. 18 to 21 and a brief description thereof follows.
[0006] As illustrated in FIG. 18, a stand 104 whose axial direction is a substantially vertical direction of the vehicle, is fixed on a mirror stay 102 which is fixed at a side of the vehicle. An electrically powered housing unit 106 is provided on the rotation shaft 104 A of the stand 104 , so as to be rotatable about the axis of the shaft. A mirror main body portion 110 comprising a mirror 108 and the like is connected to and supported by the electrically powered housing unit 106 .
[0007] When a driving motor inside the electrically powered housing unit 106 operates, it works to rotate a gear plate 112 (See FIG. 20), which is axially supported by the rotation shaft 104 A, via a gear mechanism. However, the gear plate 112 is always held so that it does not rotate with respect to the rotation shaft 104 A. Thus, the electrically powered housing unit 106 itself rotates around the rotation shaft 104 A. Since the mirror main body 110 is connected to and supported by the electrically powered housing unit 106 , the mirror main body 110 rotates, along with the electrically powered housing unit 106 , between the housed position and the position for viewing.
[0008] The schematic structure of a case 114 , which forms the exterior of the electrically powered housing unit 106 , will be described with reference to FIGS. 19 and 20.
[0009] [0009]FIG. 19 shows a schematic plan view of the case 114 , which forms the exterior of the electrically powered housing unit 106 in the door mirror device 100 . FIG. 20 shows a longitudinal section view of the case 114 . A cylindrical support shaft portion 116 is erected at the left side, in the drawing, of the top surface of the case 114 , and a circular concave portion 118 is formed around the support shaft portion 116 . The rotation shaft 104 A of the stand 104 is inserted inside the support shaft portion 116 , and the case 114 is axially supported by the rotation shaft 104 so as to be rotatable. In addition, the gear plate 112 , which applies anti-drive force to the electrically powered housing unit 106 and the mirror main body 110 , is held so as to be fixed at the top end side of the support shaft portion 116 .
[0010] In the electrically powered housing unit 106 having the above-described structure, the load of the electrically powered housing unit 106 and the mirror main body 110 must be supported by the support shaft portion 116 of the case 114 . However, the strength of the support shaft portion 116 of the case 114 may be insufficient. Thus, external forces such as vehicle vibrations act on the door mirror device 100 and, as indicated by the arrow in FIG. 21, the mirror main body 110 vibrates in a substantially longitudinal direction of the vehicle, about a center in the vicinity of the support shaft portion 116 (the vicinity of the base of the stand 104 ). In order to limit this type of vibration, increasing the rigidity of the support shaft portion 116 has been considered. In order to do this, the plate thickness of the case 116 and/or the bottom portion 114 A of the case 114 can be increased, thereby reinforcing the case 114 . However, if this is done, there is the possibility that problems will be caused such as the generation of shrinkage and warping on a surface of the mirror. Also, it may be necessary to increase the number of cycles in the production process, leading to increased production costs.
[0011] Prior Art 2
[0012] Door mirror devices are usually equipped with a housing mechanism, and the housing mechanism includes a stand which is fixed to the vehicle side. The stand is provided so as to be integral with a support shaft.
[0013] The housing mechanism is equipped with a case member, and the case member is supported by the support shaft so as to be rotatable. The case member is connected to a mirror for viewing the rear of the vehicle and the case member always swings together with the mirror.
[0014] A motor base is fixed to an inner portion of the case member and a motor is fixed to the upper side of the motor base by screws. A motor output shaft passes through the motor base, and a worm gear is press-inserted onto the motor output shaft through the lower side of the motor base. As a result, the worm gear is swung by the motor being driven.
[0015] A helical gear meshes with the worm gear and the helical gear is rotated by the rotation of the worm gear. Thus, a rotational force is applied to the support shaft and the case member is rotated by anti-rotational force. The mirror can thus be housed or swung out for viewing.
[0016] However, with this type of door mirror device, the worm gear is press-inserted onto the motor output shaft, and is not movable in an axial direction with respect to the motor output shaft. As a result, there is a problem that the motor output shaft receives a sliding force from the worm gear, and this reduces the life span of the motor.
[0017] In order to solve this problem, door mirror devices are provided in which the motor output shaft and the worm gear are separate, and the worm gear is not rotatable with respect to the motor output shaft, but is movable in the axial direction thereof.
[0018] However, in this type of device, there is a tendency for the worm gear to displace in a perpendicular direction with respect to the motor output shaft. As a result, the sound of the operation between the worm gear and the helical gear becomes very loud and in some cases the worm gear may skid.
[0019] Prior Art 3
[0020] Further, in the door mirror device described above, the stand has a pair of stand concavities which are provided on a circle having the support shaft at the center thereof. The respective end portions of the stand concavities project upwards and face each other.
[0021] A gear plate is rotatably disposed around the support shaft which rotatably supports the case member, and a rotational force is applied to the gear plate by the motor being driven. The upper surface of the gear plate is provided with insertion convexities, which project upwards.
[0022] A clutch plate is disposed around the support shaft above the gear plate, and the clutch plate is not rotatable with respect to the support shaft. Insertion concavities are provided at a lower surface of the clutch plate, and end portions of the insertion concavities project downwards. The insertion convexities of the gear plate are inserted into these insertion concavities and as a result, the clutch plate meshes with the gear plate.
[0023] A compression coil spring is penetrated by the support shaft above the clutch plate, and push nuts are fixed on top of the compression coil spring. The compression coil spring is anchored by the push nuts, and the compression coil spring urges the clutch plate.
[0024] A pair of case convexities, formed on a circle having the support shaft at the center thereof, are provided at a lower portion of the case member. Each of the case convexities projects downwards, and they face each other.
[0025] When a rotational force is applied to the gear plate by the motor being driven, the clutch plate blocks the rotation of the gear plate. As a result, the case member is rotated by anti-rotational force exerted at the gear plate, and the mirror swings in a housing direction or in a viewing direction. Also, when the end portions of the case convexities engage with the end portions of the stand concavities, the case member is anchored, and the mirror can be stopped at the housed position or at the position for viewing.
[0026] On the other hand, if an external force exceeding a predetermined value acts on the case member, the urging force of the compression coil spring is resisted and the insertion convexities are disengaged from the insertion concavities. By the gear plate and the case member swinging with respect to the clutch plate, impact of the force can be ameliorated and damage to the gear plate is prevented.
[0027] However, in this type of door mirror device, end portions of all of the case convexities, the stand concavities, the insertion convexities and the insertion concavities are inclined surfaces having an upper area and lower area which are co-planar with each other. As a result, when the end portions of the case convexities engage with the end portion of the stand concavities, if the case convexities and the stand concavities undulate, they are connected linearly. Also, when the insertion convexities are inserted into the insertion concavities, or when insertion convexities and insertion concavities are disengaged, if the end portion of the insertion convexities and the end portion of the insertion concavities undulate, the insertion convexities and the insertion concavities are connected linearly. As a result, the case convexities, the stand concavities, the insertion convexities and the insertion concavities become worn and the durability of the mirror device is poor.
[0028] Since two sets of the case convexities and stand concavities are arranged on the same circle, whose center is the support shaft, when the end portions of the case convexities are engaged with the end portions of the stand concavities, the pressure which both the case convexities and the stand concavities receive is large and thus durability is poor. Also, when the end portions of the case convexities are engaged with the end portions of the stand concavities, the case member may rattle on the stand and as a result the mirror also tends to rattle.
SUMMARY OF THE INVENTION
[0029] An object of the present invention is to provide a door mirror device in which vibration generated at a mirror main body portion can be effectively controlled without increasing plate thickness of a support shaft portion.
[0030] Another object of the present invention is to provide a mirror device for a vehicle in which the life span of a motor is extended and slipping of a worm gear in a perpendicular direction of a shaft is controlled.
[0031] Yet another object of the invention is to provide a mirror device for a vehicle, in which durability of case convexities and stand concavities is improved.
[0032] According to one aspect of the present invention, there is provided a folding-type mirror device for a vehicle, the mirror device including: a support shaft including a base portion; a case installed on the support shaft, the case including a support portion disposed around an outer periphery of the base portion of the support shaft, a bottom portion from which the support portion projects, and at least one reinforcing rib integrally connecting an outer surface of the support portion with the bottom portion; and a mirror unit attached to the case and swingable around the support shaft, by rotation of the support portion around the support shaft, for positioning at positions including a viewing position and a folded position.
[0033] According to another aspect of the invention, there is provided an electrically powered folding mirror device for a vehicle, the mirror device including: a support shaft including a base portion; a case installed on the support shaft, the case including a fitting portion disposed around an outer periphery of the base portion of the support shaft; a mirror unit attached to the case and swingable around the support shaft, by rotation of the fitting portion around the support shaft, for positioning at positions including a viewing position and a folded position; a motor base attached inside the case; an electric motor mounted to the motor base and including a motor output shaft which penetrates the motor base; and a transmission mechanism provided inside the case, operationally connected to the motor output shaft, and including a worm gear connected with the motor output shaft so as to be moveable in an axial direction of the motor output shaft but not rotatable relative to the motor output shaft, the transmission mechanism acting to swing the case and mirror unit when the motor is operated.
[0034] According to still another aspect of the invention, there is provided a folding mirror device for a vehicle, the mirror device including: a stand; a support shaft extending from the stand and including a base portion; a case installed on the support shaft, the case including a fitting portion disposed around an outer periphery of the base portion of the support shaft; a mirror unit attached to the case, and swingable around the support shaft, by rotation of the fitting portion around the support shaft, for positioning at positions including a viewing position and a folded position; and a positioning mechanism at an interface of the stand and the case, the positioning mechanism including a plurality of convexities formed at the case and a plurality of concavities formed at the stand, the convexities being insertable into the concavities, and each convexity and each concavity including one end portion and another end portion, wherein the one end portions of the convexities are surface-contactingly engageable with the one end portions of the concavities for holding the case and the mirror unit at one of the viewing position and the folded position, and the another end portions of the convexities are surface-contactingly engageable with the another end portions of the concavities for holding the case and the mirror unit at the other of the viewing position and the folded position.
[0035] According to still another aspect of the invention, there is provided a folding mirror device for a vehicle, the mirror device including: a stand which is mountable to a vehicle body; a support shaft projecting from the stand and including a base portion; a case installed on the support shaft, the case including a fitting portion disposed around an outer periphery of the base portion of the support shaft; a mirror unit attached to the case, and swingable around the support shaft, by rotation of the fitting portion around the support shaft, for positioning at positions including a viewing position and a folded position; an electric motor disposed in the case and including a motor output shaft; and a transmission mechanism provided inside the case and operationally connected to the motor output shaft for acting to swing the mirror and case unit when the motor is operated, the transmission mechanism including a gear plate rotatably mounted to the support shaft and including a clutch plate fixed to the support shaft, the clutch plate being capable of blocking relative rotation of the support shaft and the gear plate and capable of allowing relative rotation of the support shaft and the gear plate, wherein one of the gear plate and the clutch plate includes insertion convexities and the other includes insertion concavities into which the insertion convexities are surface-contactingly fittable for the blocking of relative rotation.
[0036] The foregoing and other objects, features and advantages of the present invention will be apparent from the following description of preferred embodiments of the invention, as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] [0037]FIG. 1 is a longitudinal sectional view taken along line 1 - 1 of FIG. 4, of an electrically powered housing unit of an electrically powered housable-type door mirror device according to a first embodiment of the present invention.
[0038] [0038]FIG. 2 is a cross sectional view taken along line 2 - 2 of FIG. 3, of the electrically powered housing unit according to the first embodiment of the present invention.
[0039] [0039]FIG. 3 is a front view of the electrically powered housing unit according to the first embodiment of the present invention.
[0040] [0040]FIG. 4 is a plan view of the electrically powered housing unit according to the first embodiment of the present invention.
[0041] [0041]FIG. 5 is a front view outlining overall structure of the door mirror device according to the first embodiment of the present invention.
[0042] [0042]FIG. 6 is a front sectional view of a housing mechanism of a door mirror device according to a second embodiment of the present invention.
[0043] [0043]FIG. 7 is a front view of the housing mechanism according to the second embodiment of the present invention.
[0044] [0044]FIG. 8 is a plan view taken along line 8 - 8 of FIG. 6, of the housing mechanism according to the second embodiment of the present invention.
[0045] [0045]FIG. 9 is a sectional plan view taken along line 9 - 9 of FIG. 6, of the housing mechanism of the door mirror device according to the second embodiment of the present invention.
[0046] [0046]FIG. 10 is a plan view of a stand of a door mirror device according to a third embodiment of the present invention.
[0047] [0047]FIG. 11 is a perspective view of an end portion of a stand concavity of the door mirror device according to the third embodiment of the present invention.
[0048] [0048]FIG. 12 is a front view of the housing mechanism according to the third embodiment of the present invention.
[0049] [0049]FIG. 13 is a front sectional view of the housing mechanism according to the third embodiment of the present invention.
[0050] [0050]FIG. 14 is a side sectional view taken along line 14 - 14 of FIG. 12, of the housing mechanism according to the third embodiment of the present invention.
[0051] [0051]FIG. 15 is a plan sectional view of taken along line 15 - 15 of FIG. 12, of the housing mechanism according to the third embodiment of the present invention.
[0052] [0052]FIG. 16 is a plan view of a gear plate according to the third embodiment of the present invention.
[0053] [0053]FIG. 17 is a back view of a cam plate according to the third embodiment of the present invention.
[0054] [0054]FIG. 18 is a front view outlining overall structure of an electrically powered housable-type door mirror of the prior art.
[0055] [0055]FIG. 19 is a cross sectional view corresponding to FIG. 2, of a case to be assembled to an electrically powered housing unit of the prior art.
[0056] [0056]FIG. 20 is a cross sectional view taken along line 20 - 20 of the case and the like of FIG. 19.
[0057] [0057]FIG. 21 is a schematic side view for describing problems of a door mirror device of the prior art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0058] First Embodiment
[0059] An electrically powered housable-type door mirror device 10 according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 5 .
[0060] [0060]FIG. 5 outlines the electrically powered housable-type door mirror device 10 according to this first embodiment in an assembled state. The door mirror device 10 is fixed at a predetermined position to a side of a vehicle body. The door mirror device 10 is comprised of a door stay 12 which is a “door mirror base portion” and extends in a substantially lateral direction of the vehicle, an electrically powered housing unit 14 which swings between a housed position and a position for viewing and is axially supported by a rotation shaft 52 B (described hereinafter), which rotation shaft 52 B is erected from an extending portion 12 A of the stay 12 , and a mirror main body portion 16 which swings integrally with the electrically powered housing unit 14 .
[0061] The mirror main body 16 includes: a frame 18 which has a substantially tabular rectangle shape and is formed of a vertically disposed seat surface for mounting; a visor rim 20 which is disposed at a rear surface side of the frame 18 and is fixed to the frame 18 by screws or the like; a visor cover 22 which is disposed at a front surface side of frame 18 and is fixed to frame 18 covered with the visor rim 20 with engaging claws or the like; and a mirror 24 which is disposed at a rear portion of the visor rim 20 and held to the frame 18 such that the angle of a mirror surface is adjustable.
[0062] In addition, the electrically powered housing unit 14 is fixed to the frame 18 . This can also be regarded as mirror main body 16 being connected to the electrically powered housing unit 14 via the frame 18 , thus forming one unit. Also, by the electrically powered housing unit 14 being axially supported by the rotation shaft 52 B of a stand 52 which is described hereinafter, when the electrically powered housing unit 14 swings around the rotation shaft 52 B, the mirror main body 16 swings along with the electrically powered housing unit 14 .
[0063] Reference will be made to FIGS. 1 to 4 in the following description.
[0064] The electrically powered housing unit 14 includes: a case 26 which forms the exterior at a lower portion of the unit and whose upper end is open; a gear cover 28 which forms the exterior at an upper portion of the unit, and whose lower end is open; a motor base 30 which is disposed between the case 26 and the gear cover 28 and horizontally divides the space in the unit. Due to strength requirements, the thicknesses of the members are such that the case 26 is the thickest and the gear cover 28 is the thinnest. In addition, the gear cover 28 covering the case 26 is removably attached by a claw fitting.
[0065] The frame 18 , which is vertically disposed inside the mirror main body portion 16 , is fixed at three points on the case 26 . Two (upper and lower) points are on an outer side of the case 26 , and one point is at the lower end of an inner side of the case 26 . (A first attachment point 32 is set on the outer side of the case 26 so as to be apart from a drive motor 38 (described later), and a second attachment point 34 and third attachment point 36 are set within a transverse direction dimension of the case 26 .)
[0066] The driving motor 38 , which is a drive source, is disposed at a side portion of the outer side of the motor base 30 . A worm gear 42 is fixed co-axially to an output shaft 40 of the driving motor 38 , and a helical gear 44 meshes with the worm gear 42 . The helical gear 44 is fixed to a worm gear shaft 46 and a worm gear 48 is fixed co-axially to the worm gear shaft 46 .
[0067] A portion towards the inner side of a bottom wall portion 26 A of the case 26 is formed integrally with a cylindrical support shaft portion 50 . The stand 52 is inserted from the lower side into the support shaft portion 50 . The stand 52 is formed of a disc-shaped base portion 52 A and the cylindrical rotation shaft 52 B, which is erected from an axial center of the base portion 52 A. The outer diameter of the base portion 52 A is larger than the outer diameter of the support shaft portion 50 of the case 26 , and is disposed in a state of projecting from a lower surface side of the bottom wall portion 26 A of the case 26 . The electrically powered housing unit 14 is assembled by the base portion 52 A being fixed to an extending portion 12 A of the mirror stay 12 . The mirror stay 12 holds the rotation shaft 52 B such that the axial direction thereof is substantially in a vertical direction of the vehicle.
[0068] An upper end portion of the motor base 30 is anchored to a distal end portion of the rotation shaft 52 B of the stand 52 , and an upper end portion of the gear cover 28 is anchored to the upper end portion of the motor base 30 . Simply stated, the upper end portion of the rotation shaft 52 B of the stand 52 , the upper end portion of the motor base 30 , and the upper end portion of the gear cover 28 , form an anchoring structure. Further, an axial direction middle portion of the rotation shaft 52 B of the stand 52 is cut away at two positions opposing each other in the radial direction thereof, and thus the axial direction middle portion of the rotation shaft 52 B is formed in a substantially oval shape (athletics track shape) in plan view. Note that this cut-away portion will be referred to as “cutaway portion 54 ” hereinafter.
[0069] A substantially disc-shaped gear plate 56 is disposed, so as to be rotatable, around the rotation shaft 52 B of the stand 52 . The aforementioned worm gear 48 meshes with an outer peripheral portion of the gear plate 56 , and driving force of the driving motor 38 is transmitted thereby. Further, engagement portions whose cross sections have a trapezoid shape or the like, are formed so as to be connected in a peripheral direction on an upper surface of the gear plate 56 . A clutch plate 58 formed in a substantial disc shape is disposed on the upper surface of the gear plate 56 . Cover engagement portions whose sections have a trapezoid shape or the like and which can engage with the engagement portions of the gear plate 56 are consecutively formed in the peripheral direction on a lower surface of the clutch plate 58 , and these cover engagement portions mesh by concave and convex portions fitting together.
[0070] In addition, substantially ring-shaped push nuts 60 are fixed at a vicinity of the upper end portion of the rotation shaft 52 B of the stand 52 , and a compression coil spring 62 , which can more broadly be thought of as an urging means, is wound between these push nuts 60 and the upper surface of the clutch plate 58 . Thus, the compression coil spring 62 always urges the clutch plate 58 toward the gear plate 56 .
[0071] Further, a shaft insertion hole 64 which has a substantially oval shape (athletics track shape) and which matches the tabular sectional shape of the rotation shaft 52 B is formed at an axial center portion of the clutch plate 58 . The cutaway portion 54 of the rotation shaft 52 B corresponds to the shaft insertion hole 64 , and as a result, the clutch plate 58 cannot rotate with respect to the rotation shaft 52 B.
[0072] Slip washers 66 are disposed between a lower surface of the gear plate 56 and an upper end portion of the support shaft portion 50 of the case 26 , and also between the lower end portion of the support shaft portion 50 and the upper surface of the base portion 52 A of the stand 52 . These slip washers 66 reduce frictional resistance when the electrically powered housing unit swings.
[0073] As illustrated in FIGS. 1 and 2, ring-form concave portions 68 , which are “wall portions” are formed at the outer periphery side of the cylindrical support shaft portion 50 which is formed in the case 26 . An outer peripheral surface 50 A of the support shaft portion 50 and an inner peripheral surface 68 A of the concave portions 68 are disposed so as to face each other. A plurality of ribs 70 are formed radially from the outer peripheral surface 50 A of the support shaft portion 50 . Inner ends of these ribs 70 are connected with the outer peripheral surface 50 A of the support shaft portion 50 , outer ends are connected to the inner peripheral surface 68 A of the concave portions 68 , and lower ends are connected to a bottom surface 68 B of the concave portions 68 .
[0074] Next, the operation and effects of the first embodiment will be described.
[0075] First, movement of the door mirror device 10 at a time of housing will be outlined.
[0076] When the driving motor 38 drives, the output shaft 40 rotates about its axis. As a result, the worm gear 42 which is fixed to the output shaft 40 rotates at the same rate, and causes the helical gear 44 to rotate a lower rate. When the helical gear 44 rotates, the worm gear shaft 46 to which the helical gear 44 is fixed rotates about the axis of the helical gear 44 . As a result, the worm gear 48 which is fixed to the worm gear shaft 46 rotates at the same speed. In this manner, the driving force of the driving motor 38 is transmitted to the gear plate 56 which meshes with the worm gear 48 . However, the clutch plate 58 is frictionally engaged with the gear plate 56 by the urging force of the compression coil spring 62 . As a result, the clutch plate 58 blocks the rotation of the gear plate 56 , and thus an anti-drive force which acts on the gear plate 56 acts on the electrically powered housing unit 14 . The entire electrically powered housing unit 14 swings via the case 26 about the rotational axis 52 B of the stand 52 causing the mirror main body portion 16 to be housed.
[0077] If the mirror main portion 16 receives an external force such that an external force exceeding a predetermined value acts on the case 26 , the gear plate 56 and the clutch plate 58 which were frictionally engaged become disengaged, and rotation of the gear plate 56 with respect to the clutch plate 58 is allowed. Thus, the gear plate 56 rotates along with the case 26 , which prevents the gear plate 56 from being damaged.
[0078] The cylindrical support shaft portion 50 which is supported with the rotation shaft 52 B of the stand 52 is formed in the case 26 which forms the exterior of the electrically powered housing unit 14 . The load of the electrically powered housing unit 14 and the mirror main body 16 is exerted on the support shaft portion 50 . However, in the present embodiment of the present invention, since the reinforcement ribs 70 are provided radially on the outer periphery of the support shaft portion 50 , the rigidity of the support shaft portion 50 can be sufficiently enhanced without increasing the plate thickness of the support shaft portion 50 or the like. Correspondingly, according to the present embodiment, vibration of the mirror main body 16 in a substantially longitudinal direction of the vehicle, around a center at the vicinity of the support shaft portion 50 is efficiently restrained and further, can be prevented. Also, according to the present embodiment, since it is not necessary to increase the thickness of the support shaft portion 50 and the bottom portions of the concave portions 68 of the case 26 and the like, problems such as shrinkage and warping on the surface of the case 26 and the necessity of increasing the number of steps in the production of case 26 are not caused.
[0079] In addition, according to the present embodiment, since the ribs 70 are formed radially from the cylindrical support shaft portion 50 , the ribs 70 can be uniformly, or substantially uniformly, reinforced. As a result, a merit of the present embodiment is that stress concentration caused by unevenness in the reinforcement is unlikely.
[0080] In the present embodiment, the ribs 70 extend from the outer peripheral surface 50 A of the support shaft portion 50 outward in the radial direction and are connected to the bottom surface 68 B of the concave portions 68 . Since the outer peripheral surface 50 A of the support shaft portion 50 and the inner peripheral surface 68 A of the concave portions 68 are provided so as to be connected, the rigidity of the support shaft portion 50 is effectively enhanced. As a result, the load which acts on the support shaft portion 50 is smoothly transmitted to the bottom wall portion 26 A of the case 26 , via the ribs 70 . In other words, the load is supported by the entire case 26 .
[0081] In addition, according to the present embodiment, since the ribs 70 are plurally provided on the periphery of the support shaft portion 50 of the case 26 and the rigidity of the periphery of the support shaft portion 50 is enhanced, it is possible for the third attachment point 36 for fixing the case 26 to the frame 18 to be set within the width direction dimension of the case 26 . In other words, in the present embodiment, the third attachment point 36 is set in the vicinity of the support shaft portion 50 , and within a range that has been reinforced by the ribs 70 . Incidentally, in the case of the structure of the prior art, as shown in FIGS. 18 and 20, a third attachment point 120 is set at a position which extends in a radial direction beyond the inner side of the case 114 . Consequently, the width direction dimension of the case 26 in the present embodiment may be made shorter than in the prior art. Therefore, the electrically powered housing unit 14 can be made more compact in the width direction. Consequently, the electrically powered housing unit 14 can be used with a smaller mirror.
[0082] Although the ribs 70 for reinforcement are formed radially on the periphery of the support shaft portion 50 in the present embodiment, the ribs are not necessarily provided radially. For example, the ribs may be provided in cross shapes around the support shaft portion, or just one pair of ribs may be provided.
[0083] Also, in the present embodiment, the outer end portions of the reinforcing ribs 70 are connected to the inner peripheral surface 68 A of the concave portions 68 , but the outer end portions of the ribs do not necessarily have to be connected to the inner peripheral surface of the concave portions. Even in a case without such connection, a reinforcing effect can be expected to some extent.
[0084] Further, the present invention may be applied to a manual housing-type door mirror (besides the electrically powered housable-type).
[0085] Second Embodiment
[0086] A door mirror device 210 according to a second embodiment of the present invention will be described with reference to FIGS. 6 to 9 .
[0087] The mirror device 210 includes a housing mechanism 212 and the housing mechanism 212 is provided with a stand 214 . The stand 214 is fixed to a stay (not shown), which is fixed to a vehicle door or the like. A cylindrical support shaft 216 is provided integrally with the stand 214 so as to be erect, and the support shaft 216 is fixed via the stand 214 to a side of the vehicle body. A gear plate 218 is disposed around the support shaft 216 , and rotation of the gear plate 218 with respect to the support shaft 216 is blocked.
[0088] The housing mechanism 212 includes a case 220 and a cover 221 which covers an upper opening portion of the case 220 . The support shaft 216 is inserted through the case 220 and thus the case 220 is rotatably supported by the support shaft 216 . The case 220 is connected to a mirror (not shown) for viewing the rear direction of the vehicle via a frame and a mirror surface-adjusting mechanism, and the case 220 (and the cover 221 ) rotates integrally with the mirror.
[0089] The case 220 is provided with a horizontal surface portion 222 at a side opposite to a vehicle side (at the side indicated by arrow A in FIG. 6), at a substantially central portion in a vertical direction. A substantially cylinder-shaped fitting hole (fitting portion) 224 and a substantially cylinder-shaped blocking hole (blocking means) 226 are formed at the horizontal surface 222 , and the fitting hole 224 and the blocking hole 226 are in communication.
[0090] A substantially plate-shaped motor base 228 is mounted so as to be fixed inside the case 220 . The motor base 228 is fixed at both end portions thereof in a longitudinal direction of the vehicle, with a predetermined number of screws 230 ( 2 in the present embodiment) to the horizontal surface portion 222 within the case 220 . A substantially cylindrical-shaped standing cylinder 232 is erected at a vehicle inner side upper surface of the motor base 228 , and the support shaft 216 is disposed inside the standing cylinder 232 .
[0091] An elliptical cylinder-shaped fitting cylinder 234 is provided so as to be erect on a vehicle outer side upper surface of the motor base 228 , and a motor 236 is mounted onto the motor base 228 by the motor 236 being fitted into the fitting cylinder 234 . In addition, an output shaft 236 A of the motor 236 is inserted through the motor base 228 and disposed at a lower side of the motor base 228 .
[0092] A substantially cylindrical, hollow control portion 238 is provided on the vehicle outer side lower surface of the motor base 228 . The output shaft 236 A of the motor 236 is inserted through the center of the inner portion of the control portion 238 . The outer periphery of the control portion 238 fits into the fitting hole 224 . A substantially cylindrical-shaped blocking projection (blocking means) 240 is also provided at the vehicle outer side lower surface of the motor base 228 . The blocking projection 240 is formed integrally with the control portion 238 . The blocking projection 240 fits into the blocking hole 226 , to block rotation of the motor base 228 with respect to the case 220 .
[0093] A worm gear 242 is mounted to the output shaft 236 A of the motor 236 . A lower portion of the worm gear 242 is rotatably supported by a lower wall of the case 220 . By the worm gear 242 being simply inserted onto the output shaft 236 A of the motor 236 , the worm gear 42 is rendered unable to rotate relative to the output shaft 236 A of the motor 236 , but movable in an axial direction relative to output shaft 236 A of the motor 236 . In addition, the worm gear 242 substantially fits into the control portion 238 of the motor base 228 and can abut therein. Perpendicular direction movement of the worm gear 242 with respect to the output shaft 236 A of the motor 236 is thereby restrained.
[0094] Similarly to the worm gear 242 , a helical gear 244 is supported by the inner portion of the case 220 , and the helical gear 244 meshes with the worm gear 242 . The helical gear 244 is integrally provided with a shaft worm gear 246 , and the shaft worm gear 246 meshes with the gear plate 218 .
[0095] Thus, when the motor 236 is driven, rotational force is transmitted to the worm gear 242 , the helical gear 244 and the shaft worm gear 246 , and this rotational force is exerted on the gear plate 218 of the support shaft 216 . As a result, due to anti-rotational force, the shaft worm gear 24 swings around the gear plate 218 and causes the case 220 to swing, and the mirror thereby swings, to be housed or brought to a position for viewing.
[0096] The following is a description of the effects of the second embodiment.
[0097] When the motor 236 is driven, the worm gear 242 , the helical gear 244 and the shaft worm gear 246 are rotated, and thus the case 220 swings due to anti-rotational force which is exerted on the gear plate 218 of the support shaft 216 . As a result, the mirror swings together with the case 220 and is housed or swung to a position for viewing.
[0098] Since the worm gear 242 is mounted such that it cannot rotate relative to the output shaft 236 A of the motor 236 , but can move in an axial direction relative to the output shaft 236 A of the motor 236 , the output shaft 236 A of the motor 236 does not experience translational force from the worm gear 242 . Thus, the life span of the motor 236 can be lengthened.
[0099] Further, since the output shaft 236 A of the motor 236 does not receive sliding force from the worm gear 242 , the motor 236 can be mounted to the motor base 228 simply by fitting the motor 236 into the fitting cylinder 234 of the motor base 228 . Thus, screws for fixing the motor to the motor base as in the prior art are unnecessary, and, since the number of parts is decreased, ease of assembly is improved.
[0100] Further, the control portion 238 which is integrally provided with the motor base 228 can abut the worm gear 242 , and thus movement of the worm gear 242 in a perpendicular direction with respect to the output shaft 236 A of the motor 236 is limited. As a result, slipping of the worm gear 242 in a direction perpendicular to the shaft is prevented. Also, operational noise of the worm gear 242 and the helical gear 244 can be reduced, and skidding of the worm gear 242 can be reduced. In addition, since the control portion 238 of the motor base 228 is fitted into the fitting hole 224 of the case 220 , the control portion 238 can be favorably positioned relative to the case 220 . As a result, positioning of the worm gear 242 in the control portion 238 is also favorable and control of slipping of the worm gear 242 in a perpendicular direction with respect to the shaft is ensured.
[0101] Further, since the blocking projection 240 of the motor base 228 is fitted into the blocking hole 226 of the case 220 , rotation of the motor base 228 with respect to the case 220 is blocked. As a result, the control portion 238 is always favorably positioned in the case 220 , and thus the worm gear 242 and the control portion 238 are always favorably positioned so that control of slipping of the worm gear 242 in the direction perpendicular to the shaft is further ensured.
[0102] In the second embodiment, the blocking projection 240 of the motor base 228 is fitted into the blocking hole 226 of the case 220 as a blocking means. However, in place of this, the blocking means may be formed such that the outer periphery of the fitting hole of the case member and the outer periphery of the control portion of the motor base have shapes other than a round shape, and rotation of the motor base with respect to the case member is thus blocked by the periphery of the fitting hole of the case member and the outer periphery of the control portion of the motor base fitting together.
[0103] Also, the present invention may be applied to a fender mirror device for a vehicle.
[0104] Third Embodiment
[0105] Lastly, a door mirror device for a vehicle according to a third embodiment of the present invention will be described with reference to FIGS. 10 to 17 .
[0106] A door mirror device 310 includes a housing mechanism 312 . A stand 314 is provided to the housing mechanism 312 . The stand 314 is fixed to a mirror stay (not shown) which is fixed to a vehicle door. The stand 314 is provided integrally with a cylindrical support shaft 316 so as to be erect. The support shaft 316 is fixed by the stand 314 to a side of the vehicle body.
[0107] As shown in detail in FIG. 10, on the stand 314 , there are a plurality of different circles ( 2 in the present embodiment). A plurality of stand concavities 318 ( 2 for each circle and thus a total of 4 in the present embodiment) are provided around a center which is at the support shaft 316 . Both end portions of each stand concavity 318 project to the upper side (referred to as the case 322 side hereinafter), and, as shown in detail in FIG. 11, are formed as a concave screw surface (C), which corresponds to an upper surface of a portion of an imaginary helical body having a central axis (B) at the support shaft 316 , to which portion a concave curvature is applied. In the present embodiment, the four stand concavities 318 are disposed in a peripheral direction of the support shaft 316 so as to alternate between the outside circle and the inside circle and at angles substantially at a 90° degree range with respect to the support shaft 316 . Also, the two stand concavities 318 on each circle face each other, and stand convexities 320 which project upward are provided between the respective concavities 318 of each same circle.
[0108] Further, the housing mechanism 312 includes a substantially box-shaped case 322 and a case cover 321 which covers the case 322 . The support shaft 316 is inserted through the case 322 , and the case 322 is rotatably supported by the support shaft 316 . The case 322 is connected to a mirror for viewing the rear direction of the vehicle (not shown) via a frame and a mirror surface adjusting mechanism, and the case 322 rotates integrally with the mirror about the support shaft 316 .
[0109] A substantially ring-shaped detent plate 324 is integrally fixed to a bottom surface of a bottom wall of the case 322 . The detent plate 324 has different circles (2 in the present embodiment). A plurality of case convexities 326 (2 on each circle and thus a total of 4 in the present embodiment), are provided on the different circles, around a center which is at the support shaft 316 . Each case convexity 326 projects to the lower side (to the stand 314 side), and both end portions of each case convexity 326 are formed as convex screw surfaces with the support shaft 316 as the central axis thereof. In the present embodiment, the case convexities 326 are disposed in a circumferential direction around the support shaft 316 with angles with respect to the axis of the circle having a predetermined range, and alternating between the outside circle and the inside circle. Also, the two case convexities 326 on each circle face each other. In addition, case concavities 328 which project upwards are provided between the two case convexities 326 on each circle. Engagement is possible when one end portion of each of each case convexity 326 fits into one end portion of the corresponding stand concavity portion 318 , and when the other end portion of each case convexity portion 326 fits into the other end portion of the corresponding stand concavity 318 .
[0110] A motor 330 is housed and fixed at an inner portion of the case 322 . A worm gear 332 is mounted on the drive shaft 330 A of the motor 330 , and a helical gear 334 meshes with the worm gear 332 . The helical gear 334 is integrally provided with a shaft worm gear 336 , and the helical gear 334 and the shaft worm gear 336 always rotate together.
[0111] A substantially cylindrical gear plate 338 through which the support shaft 316 is inserted so as to be rotatable is provided at the inner portion of the case 322 . Peripheral teeth 338 A are formed on the peripheral surface of the gear plate 338 , and the gear plate 338 meshes with the shaft worm gear 336 at the peripheral teeth 338 A. Thus, when the motor 330 is driven, a rotational force is applied to the gear plate 338 via the worm gear 332 , the helical gear 334 and the shaft worm gear 336 .
[0112] As shown in detail in FIG. 16, a predetermined number (4 in the present embodiment) of insertion concavities 340 are formed on the upper surface of the gear plate 338 , and the insertion concavities 340 are disposed so as to have equal intervals between them in a circumferential direction thereof. Both end portions of each of the insertion concavities 340 project to the upper side (referred to as a clutch plate 342 side hereinafter), and are formed as concave screw surfaces with the support shaft 316 at a helix central axis.
[0113] The substantially cylindrical clutch plate 342 is disposed above the gear plate 338 . The clutch plate 342 is disposed around the support shaft 316 such that it cannot rotate relatively thereto. As shown in FIG. 17, a predetermined number (4 in the present embodiment) of insertion convexities 344 are formed on the lower surface of the clutch plate 342 , and the insertion convexities 344 are disposed so as to have equal intervals between them in a circumferential direction thereof. Each of the insertion convexities 344 projects to the lower side (referred to as the gear plate 338 side hereinafter), and both end portions of each insertion convexity 344 are formed as a convex screw surface with the support shaft 316 at a helix central axis. Each of the insertion convexities 344 is inserted when both end portions thereof are fitted into one of the insertion concavities 340 , and the clutch plate 342 is thereby engaged with the gear plate 338 .
[0114] A compression coil spring 346 is disposed above the clutch plate 342 , and the compression coil spring 346 is disposed around the support shaft 316 . Push nuts 348 , which are fixed to support shaft 316 , are disposed above the compression spring coil 346 . Thus, the compression spring coil 346 is anchored by the push nuts 348 , and the gear plate 338 is urged (pressed down).
[0115] In addition, the frame, a holding member and the housing mechanism 312 are housed in a door mirror visor (not shown), and the door mirror visor is fixed to a frame.
[0116] When a rotational force is applied to the gear plate 338 by the motor 330 being driven, the clutch plate 342 blocks the rotation of the gear plate 338 . As a result, the case 322 is caused to swing by the anti-rotational force that is applied to the gear plate 338 , in a direction for housing or in a direction in which the case is brought out for viewing. Also, the other end portion of each case convexity 326 engages with the other end portion of each stand concavity 318 , and causes the case 322 to be anchored and the mirror is stopped at the housed position, or one end portion of each case convexity 326 engages with one end portion of each stand concavity 318 , to thereby cause the case 322 to be anchored and the mirror is stopped at the position at which it is brought out for viewing.
[0117] Further, when the door mirror visor receives an external force, and an external force exceeding a predetermined value acts on the case 322 , the urging force of the compression coil spring 346 is resisted, the insertion convexities 344 and the insertion concavities 340 are disengaged, the clutch plate 342 and the gear plate 338 are disengaged, and the gear plate 338 rotates together with the case 322 , with respect to the clutch plate 342 .
[0118] The following is a description of the operation of the third embodiment.
[0119] In the door mirror device 310 , the insertion convexities of the gear plate 338 are inserted into the insertion concavities 340 of the clutch plate 342 in a state in which the urging force of the compression coil spring 346 is being exerted, and thus the gear plate 342 is engaged with the gear plate 338 .
[0120] When the motor 330 is driven, and a rotational force is applied to the gear plate 338 via the worm gear 332 , the helical gear 334 and the shaft worm gear 336 , the clutch plate 342 blocks the rotation of the gear plate 338 , and thus the anti-rotational force which is applied to the gear plate 338 swings the case 322 in the direction for housing or in the direction for viewing.
[0121] The other end portion of each case convexity 326 engages with the other end portion of each stand concavity 318 and causes the case 322 to be anchored, and the mirror is stopped at the housed position, or the one end portion of each case convexity 326 engages with the one end portion of each stand concavity 318 to thereby cause the case 322 to be anchored, and the mirror is stopped at the position at which it is swung out for viewing.
[0122] Further, when an external force exceeding a predetermined value acts on the case 322 , the urging force of the compression coil spring 346 is resisted, the insertion convexities 344 and the insertion concavities 340 are disengaged, the gear plate 338 is allowed to swing with respect to the clutch plate 342 , and thus the gear plate 338 swings together with the case 322 to thereby avoid the impact of the force, and damage to the gear plate 338 is prevented.
[0123] Both end portions of the case convexities 326 and both end portions of the stand concavities 318 are formed as screw surfaces with the support shaft 316 being the central axis, and one end portion of each case convexity 326 and one end portion of each stand concavity 318 fit together, and also the other end portion of each case convexity 326 and the other end portion of each stand concavity 318 fit together. As a result, when one end portion of each case convexity 326 and one end portion of each stand concavity 318 are engaged, or the other end portion of each case convexity 326 and the other end portion of each stand concavity 318 are engaged, the case convexities 326 and the stand concavities 318 are always in good surface contact with each other. Thus, improvement of the durability of the case convexities 326 and the stand concavities 318 can be ensured, since wear thereof is favorably controlled.
[0124] Since 4 sets of the case convexities 326 and the stand concavities 318 are provided, when one end portion of each case convexity 326 and one end portion of each stand concavity 318 are engaged, or the other end portion of each case convexity 326 and the other end portion of each stand concavity 318 are engaged, the pressure that the case convexities 326 and the stand concavities 318 each receive is reduced and thus further improvement in the durability thereof can be ensured. In addition, in the state in which one end portion of each case convexity 326 and one end portion of each stand concavity 318 are engaged, or the other end portion of each case convexity 326 and the other end portion of each stand concavity 318 are engaged, rattling of the case 322 on the stand 314 is restrained, and thus rattling of the mirror is reduced.
[0125] Further, since the case convexities 326 and the stand concavities 318 are provided on each of a plurality of different circles having the support shaft 316 as a center, when one end portion of each case convexity 326 and one end portion of each stand concavity 318 are engaged, or the other end portion of each case convexity 326 and the other end portion of each stand concavity 318 are engaged, the pressure that the case convexities 326 and the stand concavities 318 each receive is decreased even further, and thus, improvement of the durability of the case convexities 326 and the stand concavities 318 can be further ensured. It should be noted that, in the present embodiment, the case convexities 326 and the stand concavities 318 are approximately three times more durable than those of the prior art. In addition, in a state in which one end portion of each case convexity 326 and one end portion of each stand concavity 318 are engaged, or the other end portion of each case convexity 326 and the other end portion of each stand concavity 318 are engaged, rattling of the case 322 on the stand 314 is further restrained, and thus rattling of the mirror is further reduced.
[0126] In addition, since both end portions of each insertion convexity 344 and both end portions of each insertion concavity 340 are formed as a convex screw surface with the support shaft 316 as the central axis, the insertion convexities 344 and insertion concavities 340 are engaged at both end portions thereof. As a result, when insertion convexities 344 and insertion concavities 340 are engaged or disengaged, or when the one end portions of the insertion convexities 344 and the one end portions of the insertion concavities 340 undulate, or when the other end portions of the insertion convexities 344 and the other end portions of the insertion concavities 340 undulate, the surfaces of the insertion convexities 344 and the insertion concavities 340 are always in favorable contact with each other. Thus, improvement of the durability of the insertion convexities 344 and the insertion concavities 340 can be ensured.
[0127] In this third embodiment, 4 sets of the case convexities 326 and stand concavities 318 are provided. However, the number of sets of case convexities and stand concavities can be any number not less than three.
[0128] In addition, the structure of this third embodiment is such that the end portions of the case convexities 326 are formed as convex screw surfaces, and the end portion of the stand concavities 318 is formed as concave screw surfaces. However, the structure may be such that the end portions of the case convexities are formed as concave screw surfaces, and the end portions of the stand concavities 318 are formed as convex screw surfaces.
[0129] Further, in the present embodiment, end portions of the case convexities 326 and end portions of the stand concavities 318 are formed as screw surfaces with the support shaft 316 at the central axis. However end portions of the case convexities and end portions of the stand concavities may be formed as inclined surfaces having an upper area and a lower area along the radial direction of the support shaft.
[0130] In addition, the structure of this third embodiment is such that the end portions of the insertion convexities 344 are formed as convex screw surfaces, and the end portions of the insertion concavities 340 are formed as concave screw surfaces. However, the structure may be such that the end portions of the insertion convexities 344 are formed as concave screw surfaces, and the end portions of the insertion concavities 340 are formed as convex screw surfaces.
[0131] Further, in the present embodiment, the insertion concavities 340 are provided on the gear plate 338 , and insertion convexities 344 are provided on the clutch plate 342 . However, insertion convexities may be provided on the gear plate, and insertion concavities on the clutch plate.
[0132] The present invention may also be applied to a fender mirror device for a vehicle.
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A foldable mirror device for a vehicle, in which a case is mounted on a support shaft erected from a base. The case includes a ring-shaped support portion for supporting the shaft, a motor connected to a transmission for swinging the mirror, and a clutch portion for disengageably engaging with the base. The support portion can be strengthened by ribs between the support portion and other portions of the case. A worm gear of the transmission can be mounted on a motor output shaft to be freely movable therealong, and supported and constrained by supporting a bottom end of the worm gear on the case and accommodating an upper end of the worm gear in a cylindrical projection from a motor base which supports the motor. End portions of convexities and concavities at the engagement portion can be formed in a concave or convex screw shape.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is the national phase of International (PCT) Patent Application Serial No. PCT/GB02/05579, filed Dec. 9, 2002, published under PCT Article 21(2) in English, which claims priority to and the benefit of British Patent Application No. 0129435.4, filed Dec. 8, 2001, the disclosures of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to the field of water gates. In particular, it relates to a water gate made from a flexible membrane for use within a port, canal or river estuary.
BACKGROUND OF THE INVENTION
Water gates are employed in a range of impound docks, marinas and canals in order to protect vessels from the detrimental effects of tides, wind and waves. Similarly such gates are employed within lock mechanisms so as to permit vessels to move up and down from one water level to another within a canal.
A further area where water gates are employed is in the construction of flood control barriers. Typically, a number of gates are located across a river estuary and are deployed at times when tide levels rise to such a point that there is a significant danger of flooding of the surrounding area.
In order for existing flood control barriers designs to provide the necessary protection their construction requires substantial civil engineering work that includes the installation of concrete caissons. A good example of such a flood control barrier is the Thames Barrier. Such structures are therefore extremely expensive and their installation can seriously disturb the habitat of the sub-sea life forms and the surrounding environment.
The Prior Art teaches of Mitre, Sector, Radial and Flap style water gates employed for the aforementioned purposes. These all comprise steel core structures with various means for providing the required watertight seal. However, for various reasons these gate designs are prone to leakage.
In the UK alone 73% of ports that employ Mitre gates exhibit substantial levels of leakage. Such leaks cost time and the associated water losses can render the port unattractive and ultimately inoperable. Replacement gates cost in the region of .English Pound.800,000 and have a lifetime of about 30 to 50 years. However, Mitre gates require major maintenance work every 10 to 15 years that typically incurs costs of .English Pound.200,000.
In addition the effects of global warming are reducing the efficiency of Mitre gates due to increases in the associated water levels. These gates depend upon hydraulic pressure that results from the difference in the water levels from the upper side and lower side of the Mitre gate. Such increased water levels act to reduce this difference hence reducing the gate efficiency.
A second disadvantage of such gate designs is the fact that they employ hardwoods in order to provide the required watertight seals. These woods are expensive due to their limited supply and so a more environmentally friendly solution would be preferable.
Presently, Sector gates are the preferred option for replacing Mitre Gates. Although the gates themselves offer an economical alternative to the Mitre Gate they require extensive civil engineering work to be carried out to provide the required Sector gate recesses. Such civil engineering is both time consuming and expensive incurring costs of several millions of pounds.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to provide a flexible water gate suitable for retaining water in a port, canal or river estuary that is economical to build and maintain while providing a controllable means for deploying the gate when required.
It is a further object of the present invention to provide a flexible flood control barrier comprising one or more flexible water gates that can be controllably deployed at times when tide levels rise to produce an imminent risk of flooding of the surrounding area.
According to a first aspect of the present invention there is provided a flexible water gate for retaining water in a port, a canal or river estuary comprising a flexible membrane and a gate operating mechanism, wherein the gate operating mechanism moves the flexible water gate between a closed position and an open position.
Preferably the flexible water gate further comprises a plurality of support lines.
Preferably the support lines are selected from the group comprising rope, chains, cord, straps or other suitable material capable of providing the required tensile strength.
Preferably the flexible membrane comprises Nylon. Alternatively the flexible membrane comprises Polyester, although any other impermeable flexible material may be employed.
Optionally the gate operating mechanism comprises a mechanical pulley system.
Alternatively the gate operating system comprises an inflatable chamber connected to the flexible membrane and a pressurised gas control means.
Preferably the flexible water gate further comprises a plurality of adjustment means, wherein the adjustment means connect the support lines and the mechanical pulley system.
Most preferably the support lines are connected to the mechanical pulley system in a substantially vertical plane, wherein when the mechanical pulley system moves the support lines downwards within the said substantially vertical plane the flexible water gate moves from the closed position to the open position.
Preferably the adjustment means comprises a turn buckle adjustment screw wherein the turn buckle adjustment screw allows the tension within the support lines to be varied.
Preferably the mechanical pulley system is housed within recesses located on either side of the flexible membrane.
Preferably the flexible water gate further comprises a side seal associated with each recess.
Preferably the flexible water gate further comprises a step associated with a canal, port or river bed on which is located a bottom seal, a support means, a clamp and a fixing means wherein the support means, clamp and fixing means act to secure the bottom edge of the flexible membrane.
Most preferably the hydraulic pressure associated with the retained water acts to maintain the flexible membrane against the side seals and the bottom seal so rendering the flexible water gate watertight.
Preferably the mechanical pulley system comprises two or more support frames, a chain and a plurality of pulley wheels, wherein the chain and pulley wheels are arranged such that the chain provides at least two substantially vertical sections such that the sections of the chain that fall within these vertical sections travel with the same velocity.
Preferably the support frames comprise a vertical post a plurality of rollers wherein the rollers are free to move along the length of the vertical post.
Preferably the support frame further comprises one or more support guys, and one or more pile foundations, wherein the support guys connect the pile foundations to the vertical post.
Preferably the chain and the adjustable buckle screws are connected to the rollers.
Preferably the mechanical pulley system is driven by an electric motor.
Preferably the gate operating system further comprises a buoy and a buoy anchoring means associated with either side of the flexible membrane.
Preferably the flexible membrane is connected to a buoy anchoring means via a plurality of eye connectors.
Preferably the flexible water gate further comprises a support means, a clamp and a fixing means wherein the support means, clamp and fixing means secure the bottom edge of the flexible membrane.
Most preferably the pressurised gas control means acts to inflate and deflate the inflatable chamber with a gas so causing the flexible water gate to move between the closed and open positions, respectively.
Preferably the gas is selected from a group consisting of the following air, oxygen, nitrogen and carbon dioxide.
According to a second aspect of the present invention there is provided a flexible flood control barrier comprising two or more flexible water gates in accordance with the first aspect of the present invention wherein the flexible water gates are deployed so as to be located side by side and operate independently as required during periods of flood tides.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will now be described by way of example only with reference to the accompanying figures, in which:
FIG. 1 presents a schematic illustration of a flexible water gate in accordance with an aspect of the present invention;
FIG. 2 presents a plan elevation of the support frame and the foundations employed by the flexible water gate of FIG. 1 ;
FIG. 3 presents a side elevation of a seal for the lower side of the flexible water gate of FIG. 1 ;
FIG. 4 presents a schematic illustration of a pulley mechanism employed to operate the flexible water gate of FIG. 1 ; and
FIG. 5 presents a:
(a) side view, with equal water levels, of an alternative flexible water gate;
(b) side view, with flood water levels, of the alternative flexible water gate; and
(c) perspective view of flood control barrier comprising two alternative flexible water gates,
in accordance with an aspect of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 presents a schematic illustration of a flexible water gate 1 incorporated with a canal system 2 containing a vessel 3 . The flexible water gate 1 can be seen to comprise a flexible membrane 4 made from either Nylon or Polyester, a plurality of gate ropes 5 , two support frames 6 each housed within a support frame recess 7 and two pile foundations 8 associated with each support frame 6 .
Further detail of the support frames 6 and support frame recesses 7 is presented in FIG. 2 . The support frame recess 7 comprises a Neoprene seal 9 located on the low water side of the flexible water gate 1 .
The support frame 6 comprises a vertical post 10 , a plurality of rollers 11 mounted on the vertical post 10 , two support guys 12 and a plurality of turn buckle adjustment screws 13 . The flexible water gate 1 is attached to the support frame 6 via the gate ropes 5 . A particular gate rope 5 connects to one end of a turn buckle adjustment screw 13 . The opposite end of the turn buckle adjustment screw 13 is thereafter connected to a roller 11 .
By tightening the turn buckle adjustment screw 13 tension is applied to the flexible water gate 1 . The hydraulic pressure associated with the retained water causes the flexible membrane 4 to press against the Neoprene seal 9 so forming the required watertight seal along the sides of the flexible water gate 1 .
In an alternative embodiment a support strut (not shown) may be deployed between the support frame recess 7 and the flexible membrane 4 , on the retained water side of the flexible water gate 1 . The addition of such a support strut improves the efficiency of the Neoprene seal 9 particularly in times of increased water levels on the low water side of the flexible water gate 1 .
FIG. 3 presents the means for providing the watertight seal along the bottom of the flexible water gate 1 . The lower side of the flexible membrane 4 is attached to a support tube 14 . The support tube 14 is then held in place by a clamp 15 that is fixed to the canal floor 16 by a fixing pile 17 . A further Neoprene seal 18 , incorporated within a step 19 engineered on the canal floor 16 , then provides the required watertight seal in a similar fashion to that described above. Hydraulic pressure associated with the retained water causes the flexible membrane 4 to press against the Neoprene seal 18 so forming the required watertight seal along the bottom of the flexible water gate 1 .
The flexible water gate 1 moves between a closed and open position under the action of an electric motor driven pulley system 20 shown schematically in FIG. 4 . The pulley system 20 comprises a continuous chain 21 that interacts with six pulley wheels 22 so as to provide four vertical sections 23 , 24 , 25 and 26 , and two horizontal sections 27 and 28 that cross over on the canal floor 16 . The orientation of the vertical sections 23 and 24 are such that they move in the same sense, either both up or both down. Similarly the vertical sections 25 and 26 are so inter related.
By attaching the rollers to either vertical sections 23 and 24 or vertical sections 25 and 26 of the chain 21 ′ allows for the flexible water gate 1 to be moved between the closed and open position under the control of the electric motor, as appropriate. As the flexible water gate 1 moves towards the open position the retained water is released so allowing the water levels on either side of the flexible water gate 1 to equalise.
FIG. 5 presents an alternative embodiment of the flexible water gate 29 . In particular FIG. 5( a ) presents a side view of a single flexible water gate 29 , with equal water levels on alternative sides of the gate 29 . FIG. 5( b ) presents a side view of the single flexible water gate 29 during a flood water situation such that the water levels on alternative sides of the gate 29 are no longer equal.
The flexible water gate 29 can be seen to comprise a flexible membrane 4 , an air chamber 30 , buoys 31 located at either side of the flexible membrane 4 and an anchor cable 32 associated with each buoy 31 . The flexible membrane 4 is attached at either end to an anchor cable 32 via a plurality of eye connectors 33 .
In this particular embodiment the operation of the flexible water gate 29 depends on the upper edge being buoyant therefore pulling the flexible membrane 4 tight. To engage the flexible water gate 29 , air is pumped into the air chamber 30 so as to create a positive uplift on the gate 29 . Similarly to disengage the flexible water gate 29 the pressurised air within the air chamber 30 is released allowing the structure to sink to the seabed.
As the outer water level increases the differing hydrostatic forces will cause the flexible membrane 4 to lean towards the coastline as shown in FIG. 5( b ). However, as the length of the flexible membrane 4 does not change significantly the buoyant air chamber 30 is pulled downwards. This downwards motion acts to increase the upward force so tending to pull the flexible membrane 4 back from its leaning position. Equilibrium is then established between the difference in head of water and the increased buoyancy, thereby providing stability to the flexible water gate 29 .
The flexible water gate 29 is particularly suited to helping in address the potential flooding of coastal areas. By arranging two or more flexible water gate 29 end to end a flexible flood control barrier 34 can be constructed, as presented in a perspective view in FIG. 5( c ).
The flexible flood control barrier 34 is not intended to be watertight as there will be leakage between individual flexible water gates 29 . However, the effects of such leakage is of reduced significance due to the fact that the tidal water levels are time dependant and will therefore eventually reduce with the ebbing tide.
Although the flexible flood control barrier 34 is located in position at all times, during normal tide conditions the location will only be evident by the presence of the buoys 31 anchored to the river bed. As the flexible membranes 4 are connected to associated anchoring cables the position of each individual flexible water gate 1 can be independently controlled. When not required the flexible membranes can all be moved to their relevant storage positions on the river bed.
The presence of the buoyant air chambers 30 within the flexible flood control barrier 34 provides an added advantage for such a system in that as this design is flexible it provides an energy absorbing physical barrier to the wave action and any floating debris.
Aspects of the present invention have the advantage that they provide a flexible water gate for use in a port, canal or river estuary that is both economical to build and install as well as providing a watertight barrier. By employing a non-biodegradable flexible membrane the need for subsequent maintenance is reduced, while the overall lifetime of the gate is increased, as compared to those previously described in the Prior Art.
The flexible water gate also has the further advantage that it is light and compact and so is easy to transport over long distances and so easier to deploy in areas with poor accessibility.
A yet further advantage of the flexible water gate is that it does not require the same engineering skill levels as required for the installation of the other gate designs taught in the Prior Art. Therefore, the flexible water gate reduces the disruption caused to ports, canal and river estuaries during initial installation and maintenance work.
Employing one or more flexible water gate 29 to produce a flexible flood control barrier 34 has several advantages over exiting flood barrier systems. This system removes the requirement for substantial civil engineering works to be carried out and the installation of concrete caissons. The flexible flood control barrier 34 is therefore significantly more cost efficient and has less of an environmental impact than existing systems.
When not in use the flexible membranes of the flexible water gates can be stored in the open position such that they are located on the riverbed. At such time they provide unrestricted access to marine vessels.
The foregoing description of the invention has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise form disclosed. The described embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilise the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Therefore, further modifications or improvements may be incorporated without departing from the scope of the invention herein intended.
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A flexible water gate is described that is suitable for retaining water in a port, canal or river estuary. The gate is both economical to build and maintain and comprises a gate controller that allows a flexible member to be controllably moved between a closed and open position, as required. A flexible flood control barrier that comprises one or more of the aforementioned flexible water gates is also described. These gates are deployed side to side and provide an economical way of providing flood protection to an area susceptible to flood tides. When not in use the flexible membranes of the flexible water gates can be stored on the riverbed so permitting unrestricted access for marine vessels.
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[0001] This application is a continuation of U.S. application Ser. No. 08/725,642 filed Oct. 15, 1996. The disclosure of the above application is incorporated herein by reference as part of this application.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to liquid crystal display (LCD) devices, and more particularly to color LCD devices for use with a touch-sensitive pointing input device and an image display method thereof.
[0004] 2. Description of the Prior Art
[0005] Through the trend of complexity in computerization as to diversity of information in the recent past, portable or “handheld” electronic information management tools including personal digital assistants (PDAs) have found increasing applications due to advantages such as small size and light weight. In the thrust to achievement of such advanced handheld information management tools, the pen-input scheme is becoming more important for permission of direct entry of input data or instructions by use of a touch-sensitive coordinate pointing input device known as a “pen” pointer in the art through an associated tough-screen display panel in such a simple and easy way that allows users to “write down” by hand on a memo pad. As such pen-input scheme, several techniques have been proposed until today, including a technique of laminating a pen-input panel (tablet panel) on an associated display panel, a technique of common use of a display panel also as the tablet, and others.
[0006] One typical pen-input scheme incorporating the former technique has been disclosed in, for example, Published Unexamined Japanese Patent Application (PUJPA) No. 58-200384 and also in PUJPA No. 7-175591. With the prior art, an input tablet is constituted from two light transmissive substrates having lateral and longitudinal elongate electrodes for position detection. The substrates may be made of glass, polycarbonate or other polymer material. When the pen pointer is manually operated by users to draw a desired locus thereon while rendering the pen pressed onto the surface of the tablet at a tip end thereof, a coordinate detector circuit operates to sense or detect corresponding coordinates of a drawing position every time the coordinates change. A control circuit is responsive to receipt of such detected coordinates for providing adequate image data indicative of character set or graphics as pursuant to the coordinate detection result, allowing a resultant drawing image to be visually indicated on the LCD panel under the control of LCD driver circuitry.
[0007] Unfortunately, the prior art LCD devices suffer from the lack of ability to process color images for display. A need has therefore been felt for a color-image displayable LCD device for use with the pen-pointer input device permitting direct entry of input data and instructions.
SUMMARY OF THE INVENTION
[0008] It is therefore an object of the present invention to provide a new and improved LCD display scheme capable of avoiding the problem as faced with the prior art.
[0009] It is another object of the invention to provide an improved color image displayable LCD device while permitting direct entry of necessary data or instructions by use of an associated touch-sensitive pointing input device.
[0010] It is yet another object of the invention to provide an improved method of displaying color images on LCD devices while permitting direct entry of input data or instructions using an associated touch-sensitive pointer.
[0011] To attain the foregoing objects, the present invention provides an LCD device having a display panel with an array of picture elements or “pixels” organized into a matrix, capable of displaying an image as hand-drawn by use of a touch-sensitive pointing input device, featured in that the display device is arranged so that the image is displayable in more than one color thereon in response to operation of the pointing input device.
[0012] In accordance with another aspect of the instant invention, there is provided an LCD device including an LCD panel having an array of rows and columns of pixels defining a matrix, a position commander for determining a certain position for color display on the display panel, a coordinate detector for recognition of the certain position as determined by the commander and for generating and issuing an output signal indicative of a corresponding coordinate data, a color designator for designation of the kind of a color being selected for such color display, a memory device for storage of color data representative of the color as presently designated, a memory controller responsive to receipt of an address generated from the selected coordinate data for controlling the color data to be written into and read from the memory, and an output controller for allowing the color data read from the memory to be output onto the display panel as image data.
[0013] In accordance with still another aspect of the invention, the commander includes a pen-shaped touch-sensitive input device for use in drawing any desired locus being subject to color display on the display panel, while the coordinate detector includes a recognition function module for recognizing the locus drawn by the pen pointer thereby to provide an output being issued as X- and Y-coordinate data corresponding to the pixel dots on the is display panel.
[0014] In accordance with a further aspect of the invention, the recognition function module may include a pressure sensor, an electrostatic sensor or a heat sensor.
[0015] In accordance with a yet further aspect of the invention, the color designator is comprised of a color designation area as provided in advance for a respective one of colors on the display panel permitting selection of any desired color in response to the commander. With the invention also, the color designator may be a color selection menu allowing the operation mode to be set in a color selection mode and permitting selection of a desired color through the color selection mode. The display panel may be of the active matrix type having thin-film transistors (TFTs) disposed at the pixels thereon.
[0016] In accordance with a still further aspect of the invention, there is provided a method for displaying a color image on an LCD panel with a matrix of rows and columns of pixels by using a pen-like touch-sensitive input device operatively associated therewith, which method includes the steps of designating a color to be displayed in advance, drawing on the display panel a locus being color-displayed by use of the pen pointer input device, providing the address of an associated data storage device based on the resulting coordinate data corresponding to the locus drawn, writing the selected color data into the storage device at the designated address thereof, and reading color data from the storage device thereby generating and issuing the same to the display panel as image data.
[0017] In accordance with the invention, the LCD panel has a matrix of rows and columns of pixels. To display a color image, a color designation means acts first to designate or determine the color to be displayed. This color designation may be performed by execution of pointing one of color designation areas each predefined for the individual color on a display panel; or alternatively, the same may be attained by setting the operation mode in a color selection mode through operation of a color selection menu.
[0018] Then, a position commander unit operates to instruct a specific position being subject to such color display on the display panel. More practically, the commander may be a touch-sensitive pointing input device, which is generally known as a “pen pointer” tool. This pen pointer is for use in drawing any desired line of locus to be color-displayed on the LCD panel screen. Each position designated by the commander is next recognized by a coordinate detector unit, which generates and issues corresponding coordinate data at an output thereof. The coordinate detector includes a recognizer for recognition of the locus as drawn or defined by movement of the pen pointer in such a way that the detector issues an output of recognizer as data indicative of X- and Y-coordinates corresponding to pixels or dots on the display panel. The recognizer here may be a pressure sensor, electrostatic sensor, heat sensor, or the like.
[0019] A storage controller unit is responsive to receipt of the resulting coordinate data for generating and issuing an address selected. Based on the address, the controller also serves to control read/write operations of color data with respect to a memory associated. The color data stored in the memory is then read out under the control of the storage controller to be supplied as video data to the display panel. In this way, it becomes possible to display a color image by use of pen input device.
[0020] These and other objects, feature's and advantages of the invention will be apparent from the following more particular description of one preferred embodiment of the invention, as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] [0021]FIG. 1 is a block diagram showing an overall configuration of a color LCD device in accordance with one embodiment of the invention.
[0022] [0022]FIG. 2 is a diagrammatical representation for explanation of a color data storage scheme as employed in the LCD device of FIG. 1.
[0023] FIGS. 3 ( a ) to 3 ( c ) depict some models of the contents of a memory in the LCD device shown in FIG. 1.
[0024] [0024]FIG. 4 illustrates a configuration of table data as stored in a color designator circuit of the embodiment of FIG. 1.
[0025] [0025]FIG. 5 shows a configuration of electrical circuitry of an LCD panel as employed in the FIG. 1 embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0026] Referring to FIG. 1, a liquid crystal display (LCD) device in accordance with one preferred embodiment of the invention includes an LCD panel with a matrix of rows and columns of picture elements or “pixels,” which may also be called the “dots” in some cases. The LCD panel comes with a coordinate detector device 2 for detection of coordinates as input by an associated pen-shaped touch-sensitive pointing input device known as an “input pen” or “pen pointer” in the art. Here, the LCD panel is of the active-matrix type which may be configured as shown in FIG. 5. As shown, the active-matrix LCD panel incorporates a matrix of pixels, each of which is at a corresponding one of cross points or intersections between horizontal scanning lines 52 and vertical signal transmission lines 53 . The individual pixel includes therein a switch element 50 , which selectively turns on and off controlling adequate transfer of image information to an associative display medium. This medium may be a liquid crystal material 51 . The switch element may be a three-terminal element, typically a thin-film transistor (TFT) having the gate, source and drain electrodes. The scan lines 52 are connected to the gates of TFTs 50 , whereas the signal lines 53 are to the sources (or drains) thereof.
[0027] As shown in FIG. 1, the coordinate detector 2 includes a pair of X/Y-coordinate recognition sensors 21 for recognition of the position of an arbitrary point as presently designated by the input pen 1 , by detecting the X- and Y-coordinates thereof on the LCD display panel. The detector 2 also includes a coordinate detector circuit 22 , which is responsive to receipt of the recognition data as derived from the X/Y-position recognition sensors 21 for generating and issuing at the outputs X- and Y-coordinate data that correspond to dots on a one-to-one correspondence basis. The sensors 21 may be pressure sensors, electrostatic sensors, heat sensors, or the like.
[0028] The coordinate detector 22 is connected to a memory controller circuit 3 . This controller is to perform physical address settings and read/write control for an associative memory device 4 (described later). More specifically, the controller 3 generates and issues a physical address(es) for data write in memory 4 in response to the coordinate data (X- and Y-coordinate data) as detected by coordinate detector 22 . Controller 3 also receives information sent from a sequence controller circuit 5 (later described) to generate when data write a write command signal such as write enable (WE) at a certain timing. During read mode, controller 3 attempts to control data read operation at memory 4 by providing physical address control for display on the LCD panel and generating a necessary signal (control signal) therefor.
[0029] The memory controller 3 is connected to the memory 4 and also to a color designator circuit 6 and a panel display timing signal generator circuit 7 . The coordinate detector 2 , memory controller 3 , color designator 6 and timing generator 7 are connected to the sequence controller circuit 5 so that they operate under the control of it. Memory 4 is connected through an RGB conversion table 8 to an output controller circuit 9 . The panel display timing generator 7 is also connected to output controller 9 .
[0030] The memory 4 has in its memory space a prescribed number of addresses as equivalent in number to the resolution of the display panel, namely, equal to the total number of pixel dots thereon. Memory 4 can store therein N-bit data enabling handling of 2 N colors of image data. By way of example, in cases where sixteen (16) different colors are required for display, the memory is designed to be 4-bit data storable memory. Further, memory 4 has N sets of storage regions; for example, in the case of 16 different colors, it is designed to have four sets of storage regions MEM 0 , MEM 1 , MEM 2 , MEM 3 as shown in FIG. 2, each of which can store therein 4-bit data separately. Note here that FIG. 2 diagrammatically represents a model of the operational correlation of coordinate detector 2 and memory 4 .
[0031] The color designator 6 operates when predefined color selection (designation) coordinates are pointed on the LCD display panel to set a certain color data corresponding to the presently pointed color thereon. Here, the “color designation coordinates” may refer to an area as provided on the LCD display panel for the individual color. For instance, in cases where sixteen (16) colors are needed for display, 16 separate areas are provided on the panel, each of which is associated with a corresponding one of such colors required. With such an arrangement, selecting any desired color becomes available by execution, using pen 1 , of “pointing” color designation coordinates (color distinction area) as desired for color display.
[0032] It should be noted here that the color data may be specific data variable in value from zero (0) to 2 N−1 that can be handled or processed by memory 4 with N sets of storage regions. For example, in the situations where 16 different colors are to be implemented for use, the data is designed to have any value as selected from “0” to “15” that can be handled by memory 4 with four sets of storage regions MEM 0 -MEM 3 . The color designator 6 has one exemplary built-in table as shown in FIG. 4. This table shown is for use in 16-color display schemes; for example, when a “black” is selected based on the color selection coordinates, a corresponding digital color data “1111” is set. Alternatively, when a “red” is designated due to color designation coordinates, a color data “0001” will be set. In such cases, allocation between colors and color data items may be determined in an arbitrary manner.
[0033] In the illustrative embodiment the color selection coordinates (color distinction area) are arranged on the LCD display panel enabling selection of any desired color for display by use of the “pen-pointing” techniques; this may alternatively be modified such that an exclusive color selection menu is provided at a selected position on the display screen allowing users to operate it to attain selection of any color for display. In other words, operating the color selection menu causes the screen to change in operation mode so that it is set in a color selection mode for permission of color selection by way of such resultant color selection screen. This may advantageously avoid the need of providing in advance the color distinction areas on the LCD display panel enabling more efficient use of display screen in area.
[0034] The panel display timing generator 7 functions to generate and issue at its output a write synchronization (sync) signal, an operation clock signal, a reset command signal (an initializing signal) and others for the LCD display panel, memory controller 3 , and output controller 9 . The RGB conversion table 8 is for conversion of data read from the memory 4 into corresponding actual color data during display operation of the LCD panel. Output controller 9 operates to provide retiming, digital-to-analog (D/A) conversion and level-shift operations of video data and display control signals.
[0035] In the embodiment thus arranged, a color selected by use of either the color selection coordinates (color distinction area) or the color selection menu on the LCD panel screen is converted by the color designator 6 to a corresponding color data, which is then stored in respective storage regions of the memory 4 . By way of example, assume that sixteen (16) different colors are available for display: in this case, resultant color as selected through operation of the color selection coordinates (color distinction area) or the color selection menu is converted using the table (see FIG. 4) of color designator 6 into 4-bit color data, and is then stored in a respective one of the storage regions MEM 0 -MEM 3 of memory 4 shown in FIG. 2.
[0036] The color data stored in the memory 4 in this way is thereafter read out of it under the control of memory controller 3 to be sent forth to the RGB conversion table 8 . RGB conversion table 8 is rendered operative to convert the input color data to RGB data for actual display on the LCD panel screen, which is then passed to the output controller 9 . Output controller 9 attempts based on a signal(s) from the panel display timing generator 7 to display such RGB data on the LCD panel as video information. In this way, any desired color display is available in responding to input by pen 1 .
[0037] The operation of the illustrative embodiment will be described in detail as follows.
[0038] The following description assumes that sixteen (16) different colors are employed for display. Imagine that as shown in FIG. 2, a curvature line A is to be displayed in “black” whereas a straight line B is in “red” on the LCD screen. Consider here that the display screen is initially displayed in “white” as its background color.
[0039] Under the above condition, the memory 4 has four sets of separate storage regions MEM 0 -MEM 3 as shown in FIG. 2, while the content of color data being stored in each region is shown in FIGS. 3A to 3 C. FIG. 3A shows the initial condition of such storage regions MEM 0 -MEM 3 , all of which store therein logic data “0” since the LCD background color is “while” as mentioned previously. FIG. 3B illustrates the storage contents of respective regions MEMO-MEM 3 as observed just after completion of pen-input of the curve A of FIG. 2, whereas FIG. 3C depicts the contents of regions MEM after pen-input of the straight line B of FIG. 2.
[0040] First, the operator designates in advance his or her desired color to be displayed on the LCD screen. This color designation is attained either by execution of “pointing” the color designation coordinates (color distinction area) or by using a color selection menu as displayed on the screen.
[0041] Since this example assumes that the curve A is first displayed in “black,” the operator selects the “black” by pointing the color designation coordinates or by making use of the color selection menu. The resulting color selected is then converted by the color designator 6 into color data. Practically, such designated color is converted using the conversion table (see FIG. 4) and is sent forth as output data. In this case, the “black” is converted into a 4-bit digital signal “1111”.
[0042] After completion of the color designation for display in the foregoing way, the operator then uses the input pen 1 to draw his or her desired locus on the LCD display panel. In this example the curve A is hand-drawn on the display panel. The resulting locus as drawn on the display panel is output by the coordinate detector 2 as appropriate coordinate data (the data representative of X- and Y-coordinates), and thereafter is input to the memory controller 3 . In responding to this, memory controller 3 generates and issues at its output physical addresses based on the input coordinate data, attempting to sequentially write color data into memory 4 at such addresses generated. The entire storage space of memory 4 is divided into four regions MEM 0 -MEM 3 allowing the 4-bit color data to be written into these regions MEM. The result of such data write into regions MEM is demonstrated in FIG. 3B.
[0043] Then, for display of the straight line B in “red” on the LCD panel, the operator selects the “red” through pointing of the color designation coordinates (color distinction area) or using the color selection menu. Any resultant color selected is then converted by the color designator 6 . In this case the selected color is converted by the conversion table (see FIG. 4) into 4-bit color data “0001”.
[0044] After completion of the color designation for display, the operator attempts to hand-draw using the input pen 1 his or her desired locus, namely, line B of FIG. 2 for example on the LCD display panel. The locus drawn is output by the coordinate detector 2 as X/Y-coordinate data and is then supplied to the memory controller 3 , which generates and issues at its output physical addresses sequentially writing color data into memory 4 at such addresses generated. Practically, the 4-bit color data “0001” is stored in four regions MEM 0 -MEM 3 of FIG. 2, respectively. The result of such data storage in regions MEM is presented in FIG. 3C.
[0045] The resultant color data bits as stored in the memory 4 are later read sequentially from it under the control of memory controller 3 to be supplied in this order to the RGB conversion table 8 . RGB conversion table 8 automatically converts the input color data to corresponding RGB data, which is then fed to the output controller 9 . Output controller 9 executes D/A conversion for the RGB data as input thereto deriving at its output an analog color video signal, which is then supplied to the LCD panel. In this way, the pen-input locus patterns (curve A and straight line B) are finally displayed on the LCD screen in the operator's designated colors, e.g., “red” or “black” in this case.
[0046] It will possibly be desired that the locus patterns are in other colors. If this is the case, the aforesaid operation will be repeated while the operator occasionally selects his or her preferred color(s) by execution of pointing the color designation coordinates (color distinction area) or using the color selection menu available at every step for color selection.
[0047] As necessary, an extra selection menu for selection of the background color and line colors may be additionally arranged on the display panel. To attain such background-color designation, it should be required that a presently designated color data be written into the memory 4 at corresponding addresses thereof. This may be accomplished by employing a specific scheme as follows: reading data out of memory 4 , and replacing the “old” data being previously stored at an address of the background color data before such background color designation with the updated background color data as presently selected. This data replace scheme may be attained using either one of an exclusive hardware arrangement and software programs.
[0048] In addition, while the illustrative embodiment has been described under the assumption that it is applied to the case of 16-color images based on 4-bit data, this invention is not exclusively limited thereto, and may be modified in arrangement to be applicable for any other cases requiring an increased number of colors for display. Furthermore, the pen-input technique as employed in the embodiment may be replaced with any other functionally equivalents, including the use of a multi-layered panel structure with the pen-input panel being stacked on the display panel, the use of a common panel structure allowing a panel to function both as the display screen and as the pen-input sheet.
[0049] It has been described that the present invention can provide the LCD display device permitting pen input on its display panel and the display method therefor.
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There is disclosed a color liquid crystal display (LCD) device capable of displaying color images in response to direct entry of input data and/or instructions through operation of an associated coordinate pointing tool. Typically, this tool is a pen-like input device known as the “input pen” for use in determining the individual position for color display on the screen of a built-in LCD panel. A coordinate detector operates to recognize the position as designated by the input pen, generating and issuing an output signal indicative of the corresponding coordinate data. A color designator circuit designates a color as presently selected for color display. A memory device stores therein color data representative of the color designated. A memory controller is responsive to receipt of an address issued from the selected coordinate data for controlling the color data to be written into and read out of the memory. An output controller allows the color data read from the memory to be supplied to the LCD display screen as video data.
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BACKGROUND OF THE INVENTION
[0001] In the manufacture of tissue products such as bath tissue, a wide variety of product characteristics must be given attention in order to provide a final product with the appropriate blend of attributes suitable for the product's intended purposes. Improving the softness of a tissue product has always been a major objective for premium products. The major components of softness include stiffness and bulk (density), with lower stiffness and higher bulk (lower density) generally improving perceived softness.
[0002] One traditional approach to producing tissue products has involved compression of a wet laid web between an absorbent felt and the surface of a rotating heated cylinder such as a Yankee dryer. The dried web is thereafter dislodged from the Yankee dryer in a creping process in which a blade is used to partially de-bond the dried web by breaking many of the bonds previously formed during the wet pressing stages of the process. Creping generally improves the softness of the web, albeit at the expense of a significant loss in strength.
[0003] More recently, throughdrying has become a more prevalent means of drying tissue webs. Throughdrying provides a relatively non-compressive method of removing water from the web by passing hot, dry air through the web until it is dry. More specifically, a wet-laid web is transferred from a forming fabric to a coarse, highly permeable throughdrying fabric and retained on the throughdrying fabric through passage of a “through air dryer”, (hereinafter TAD). The resulting dried web is softer and bulkier than a wet-pressed uncreped dried sheet because fewer paper-making bonds are formed and because the web is less dense.
[0004] Although throughdried tissue products exhibit good bulk and softness properties, throughdrying tissue machines are expensive to build and operate. Accordingly, there is a need for improvements for a throughdrying apparatus and process which produces high quality tissue products.
SUMMARY OF THE INVENTION
[0005] It has now been discovered that in the manufacture of uncreped, throughdried tissue sheets, improved efficiencies and a higher quality end tissue product may be obtained by the addition of high temperature steam to the drying medium. In so doing, tissue sheets can be made which have improved absorbance and softness values. Further, the addition of high temperature steam to the drying medium allows the throughair drying process to be carried out more economically and under conditions which eliminate the scorching or burning of the drying web.
[0006] Hence, in one aspect, the invention resides in a method for making a throughdried tissue comprising depositing an aqueous suspension of papermaking fibers onto a forming fabric to form a wet web, transferring the wet web to a throughdrying fabric, and throughdrying the web to form a tissue sheet. The use of a drying medium having a high steam content of between 10 percent to 100 percent by volume of the medium allows the use of higher drying temperatures compared to a conventional heated air drying medium. The steam enhanced drying medium converts the free moisture within the fabric web to a water vapor and which is removed by the passage of the drying medium.
[0007] Hence, in another aspect, the invention resides in the foregoing method wherein the tissue sheet is dried using a drying medium in which high temperature steam is added to increase the temperature of the drying medium above the burning temperature of paper. The addition of live steam reduces the concentration of oxygen and allows a higher drying temperature to be achieved without scorch or burning of the paper web.
[0008] In a further aspect, the invention resides in supplying a drying medium to a fabric web in which the drying medium is substantially free of oxygen. As used herein, the term “substantially free” is defined as having a free oxygen content of a sufficiently low concentration such that burning or scorching of a paper web is prevented when the drying medium temperature is above the traditional scorch or burning temperature for a heated air TAD process. Likewise, the term “reduced oxygen drying medium” is defined as a heated air medium in which a percentage of the drying medium comprises live steam. As such, the oxygen gas concentration within the drying medium is reduced compared to a heated drying medium without the addition of live steam. Typically, heated air will have an O 2 percentage of about 21%.
[0009] The use of a reduced concentration oxygen gas or substantially oxygen-free drying medium allows a drying temperature higher than the scorch or burn temperature of a paper web to be used. The scorch temperature of a paper web may vary depending upon the thickness and quality of the referenced web. However, the scorch temperature for any particular paper web may be readily determined and such temperatures are, in fact, known values within the industry for various types of commercially produced webs.
[0010] The use of an elevated throughair drying temperature brings about an additional improvement in the water absorbency and softness of the tissue fabric by the provision of a supply-side drying temperature above the glass transition point of paper fiber. The elevated temperatures allow the paper fiber to mold and permanently set the pulp fibers in an altered and desired shape.
[0011] In yet a further aspect, the invention resides in the foregoing method wherein the introduction of pressurized steam into the drying medium increases the velocity of the drying medium. This, in turn, lowers the energy demand on electric blowers and fans proportional to the motive energy provided by the introduced steam.
[0012] In yet a further aspect, the invention resides in a papermaking process in which the drying medium, upon leaving the throughdried web, has a portion of the resulting exhaust stream discharged along annular gaps defined between a throughair dryer hood and the associated paper web and drum. The discharge of the used drying medium forms a curtain seal along the annular gap seals and dryer web entry slot, thereby preventing cooler, oxygen-rich ambient air from infiltrating into the drying medium loop. Simultaneously, the exhaust curtain seals allow the discharge of a portion of the used drying medium so as to maintain an equilibrium of the drying medium circulation loop.
[0013] In yet another aspect, the invention resides in a method of making a tissue sheet wherein the throughair drying step is carried out by a drying medium comprising substantially about 100 percent (by volume) live steam. The use of substantially about 100 percent live steam will greatly reduce and may eliminate the need for electric motors used to circulate the drying medium. As a result, increased efficiencies can be obtained by the cost savings reflected in the use of pressurized steam as opposed to electric blowers to move the drying medium.
[0014] These and other aspects of the invention will be described in greater detail in reference to the figures and specification set forth below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] A full and enabling disclosure of the present invention, including the best mode thereof, to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying drawings.
[0016] [0016]FIG. 1 is a perspective view of a process line for producing a throughdried tissue product in accordance with this invention;
[0017] [0017]FIG. 2 is a schematic flow diagram of a TAD apparatus and drying process in which high energy steam is added as a component of the drying medium;
[0018] [0018]FIG. 3 is a schematic flow diagram of a TAD apparatus and process for the substantially oxygen-free drying of a tissue web;
[0019] [0019]FIG. 4 is a schematic view setting forth details of a steam injection apparatus and process for a TAD; and
[0020] [0020]FIG. 5 is a schematic view setting forth details of the gap sealing feature of the present invention using a portion of the discharged dryer medium exhaust to prevent the entrainment of ambient air into the drying medium loop.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Reference now will be made in detail to the embodiments of the invention, one or more examples of which are set forth below. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment, can be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover such modifications and variations as come within the scope of the appended claims and their equivalents. Other objects, features, and aspects of the present invention are disclosed in the following detailed description. It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only and is not intended as limiting the broader aspects of the present invention, which broader aspects are embodied in the exemplary constructions.
[0022] In describing the various figures herein, the same reference numbers are used throughout to describe the same apparatus or process pathway. To avoid redundancy, detailed descriptions of much of the apparatus once described in relation to a figure is not repeated in the descriptions of subsequent figures, although such apparatus or process is labeled with the same reference numbers.
[0023] Referring first to FIG. 1, there is illustrated a process line 10 suitable for carrying out the preferred process of the present invention. The description given in reference to FIG. 1 is illustrative of but one process and apparatus for making a tissue product in which a throughair dryer is utilized. It is understood and appreciated by one having ordinary skill in the art that a variety of throughair drying apparatuses and paper-making processes may be used in conjunction with the present invention.
[0024] The process line begins with a papermaking furnish 12 comprising a mixture of secondary cellulosic fiber, water, and a chemical debonder which is deposited from a conventional headbox (not shown) through a nozzle 14 on top of a foraminous wire forming belt 16 as shown in FIG. 1. The forming belt 16 travels around a path defined by a series of guide rollers. The forming belt 16 travels from an upper guide roller 20 , positioned below and proximate to the headbox nozzle 14 , horizontally and away from the headbox nozzle to another upper guide roller 22 , passes through the upper guide roller 22 and diagonally and downwardly to a lower guide roller 24 , passes under the lower guide roller 24 and diagonally and upwardly toward the nozzle 14 to a lower guide roller 26 , passes over lower guide roller 26 and diagonally and downwardly to lower guide roller 28 , passes under lower guide roller 28 and turns upwardly and slightly inwardly to a guide roller 32 , passes behind the guide roller 32 and upwardly and outwardly returns to upper guide roller 20 .
[0025] A vacuum forming box 34 positioned beneath the forming belt 16 proximate to the opening 36 of the headbox nozzle 14 immediately extracts water from the moist fibrous web 38 deposited on top of the forming belt by the headbox nozzle. The partially dewatered fibrous web is carried by the forming belt 16 in the clockwise direction as shown in FIG. 1, towards the upper guide roller 22 . The fibrous web 38 as it moves away from the vacuum forming box 34 , in one embodiment may comprise from about 19 percent to about 30 percent cellulosic fiber by weight. An edge vacuum 40 positioned below the forming belt 16 and proximate to the upper guide roller 22 assists in trimming the edges of the fibrous web 38 .
[0026] The fibrous web 38 passes over the upper guide roller 22 and downwardly between the forming belt 16 and a throughdryer belt 42 . The throughdryer belt 42 travels around a path defined by a series of guide rollers. The throughdryer belt 42 travels from a guide roller 44 positioned above and vertically offset from guide roller 22 downwardly towards the forming belt 16 , contacts the fibrous web 38 , and then downwardly and diagonally away from guide roller 24 to guide roller 46 , passes under guide roller 46 and turns horizontally away from the forming belt 16 towards a throughdryer guide roller 48 , passes under the throughdryer guide roller 48 and turns upwardly and over a throughdryer 50 and downwardly to a second throughdryer guide roller 55 , passes under through guide roller 54 and turns upwardly to an upper guide roller 56 which it passes over and thereafter turns slightly downwardly to an upper guide roller 58 , and turns slightly upwardly in the direction of the forming belt 16 to an upper guide roller 60 , passes over upper guide roller 60 and turns downwardly to a guide roller 62 , passes under guide roller 62 and turns substantially horizontally away from forming belt 16 to a guide roller 64 , passes around guide roller 64 and turns horizontally in the direction of the forming belt 16 and returns to guide roller 44 .
[0027] A vacuum pickup 66 pulls the fibrous web 38 towards the throughdryer belt 42 and away from forming belt 16 as the fibrous web passes between the throughdryer belt and the forming belt. The fibrous web 38 adheres to the throughdryer belt 42 and is carried by the throughdryer belt downwardly below the lower guide roller 46 towards the throughdryer 50 . Vacuum boxes 68 positioned above and proximate to the throughdryer belt 42 between the lower guide roller 46 and the throughdryer guide roller 48 extract additional water from the moist fibrous web 38 . The fibrous web 38 may preferably comprise between about 25 percent and 35 percent fiber by weight after passing beneath the vacuum boxes 68 .
[0028] The TAD 50 generally comprises an outer rotatable perforated cylinder 51 and an outer hood 52 . Hood 52 is used to direct a drying medium from the drying medium supply duct (not illustrated) and which is discharged against and through the fibrous web 38 and the throughdryer belt 42 as is known to those skilled in the art. The throughdryer belt 42 carries the fibrous web 38 over the upper portion of the throughdryer outer cylinder 51 . A drying medium is forced through the fibrous web 38 and through the throughdryer belt 42 and through the perforations 53 in the outer cylinder 51 of the TAD 50 . The drying medium removes the remaining water from the fibrous web 38 and exits the cylinder 51 along conduits (not illustrated) in proximity to outlets 57 positioned along the axis 59 of cylinder 51 . The temperature of the drying medium forced through the fibrous web by the throughdryer is desirably about at least 300° F.
[0029] The throughdryer belt 42 carries the dried fibrous web 38 towards the lower guide roller 54 . The dried web 38 is directed to a take-up roller 70 where the fibrous web is wound into a product roll 74 .
[0030] Turning to FIG. 2, there is illustrated a schematic representation of a throughair dryer and process for carrying out the present invention. The drying medium in this embodiment comprises a mixture of the combustion products from a fuel burner 80 and live high temperature pressurized steam 82 . Burner 80 uses a fuel source, such as natural gas, which is burned in the presence of excess air. The resulting heated combustion products are further mixed with high energy live steam 82 and recycled drying medium 92 to provide a high temperature drying medium 90 . Drying medium 90 may have a supply side temperature of between 300° F. to 600° F. when using 1000° F. live steam as a component of the drying medium 90 . However, an even greater drying medium temperature is envisioned and may be obtained by increasing the relative amount and/or temperature of the introduced live steam. It is readily appreciated by one having ordinary skill in the art that the supply temperature of released steam may be greater or lesser than the 1000° F. live steam example set forth above. Such variations in steam temperature do not alter the ability to use the varying temperature steam so as to bring about the improvements of the present invention.
[0031] The drying medium 90 is introduced to the TAD 50 within the interior enclosure defined by hood 52 . The velocity of the drying medium 90 directs the drying medium to contact the outer supply side of moving web 38 , passing the drying medium through web 38 as the medium 90 continues through the throughbelt 42 , and into the interior cylinder 51 before exiting through outlets 57 , as seen in reference to FIG. 1.
[0032] As the drying medium 90 passes through web 38 , the drying medium 90 raises the temperature of web 38 , thereby converting the water content of the web to steam. The steam is released from the web fibers/matrix and passes into the drying medium. The circulating fan 100 is used to circulate the drying medium as it exits the web 38 . The used drying medium 92 is then recirculated in part to the feed stream of the drying medium along with additional live steam.
[0033] The returning or used dryer medium 92 , upon exiting the web 38 , will experience a temperature drop upon entry into the interior of the cylinder 51 . Further, ambient air is typically entrained into the recirculating loop pathway of mediums 90 and 92 by air leakage along gap regions of the hood baffle 61 associated with the passage of web 38 into and out of TAD 50 . To maintain a proper balance of the dryer medium constituents 90 , a portion of the used dryer medium 92 may be vented using exhaust fans 101 to maintain a desired balance of the heated combustion products, including combustion air, high energy steam, and the recycled used dryer medium 92 . The latter component may include ambient air entrained by movement of the web relative to the dryer.
[0034] Referring now to FIG. 3, an additional embodiment of the present invention is set forth in which a substantially oxygen-free drying medium 190 is used with the TAD 50 . In this embodiment, the burner 80 is operatively engaged with a heat exchanger 83 . Heat exchanger 83 is used to transfer the thermal energy from the combustion products of burner 80 to the return drying medium 192 . The actual combustion products, however, are vented from the system and do not form part of the actual drying medium 190 .
[0035] The return drying medium 192 , upon passage through heat exchanger 83 , is further mixed with live steam. The resulting heated mixture comprises the supply side drying medium 190 .
[0036] As further set forth in reference to FIGS. 3 and 5, a portion of the cooled exiting drying medium 192 may be diverted to form an air curtain along the air entrainment locations associated with the throughair dryer. A portion 195 of the exiting drying medium is discharged along an outlet adjacent the baffle and air gaps 110 defined between the throughair hood 52 and the web 38 . A partial vacuum pathway 112 may be used to establish a sustained flow path of the resulting air curtain. The air curtain precludes entry of ambient air into the throughair dryer and therefore excludes the ambient air from entry into the drying medium pathway. As seen in FIG. 3, the used drying medium 112 associated with the air curtain is thereafter vented as an exhaust product by a blower 103 . Additional portions of the used dryer medium 192 is vented by exhaust fan 101 as needed to accommodate the introduction of new quantities of live steam to reestablish the high temperature steam profile of drying medium 190 .
[0037] The pressurized release of live steam into the drying medium accomplishes several objectives. First, the steam increases the temperature of the drying medium and allows a supply side temperature of the drying medium to exceed the drying temperatures of a conventional dry air TAD. Second, the release of pressurized live steam into the drying medium pathway increases the velocity of the drying medium. As a consequence, the energy demands and capacity of electric fans or blowers associated with the drying medium circulation loop may be reduced. Third, the use of a high steam content drying medium also improves certain desirable qualities of the resulting throughair dried web. For instance, the absorbency and softness of a tissue TAD product, may be improved by raising the tissue to a temperature greater than the glass transition temperature of the cellulosic fibers. The steam content of the drying medium lowers the glass transition point of the cellulosic fibers. Further, the steam allows a higher drying temperature to be achieved. The combination of a lower glass transition temperature and higher drying temperature allows an improved product molding to occur. The molding process, as known in the art, provides a three-dimensional texture to the resulting web which is desirable for certain tissue products. The resulting molded shape is softer, more absorbent, and allows the tissue product to maintain its textured shape when exposed to moisture.
[0038] In reference now to FIG. 4, details of one example of the addition of a live steam component to a TAD medium is set forth. In the illustrated embodiment of FIG. 4, burner 80 releases an initial stream of heated combustion products. The heated combustion products are then intermixed with a fan-driven return drying medium 92 along with live steam 82 . A system of one or more baffles 84 may be placed within the respective flow paths to achieve an improved intermixing of the component fractions of the drying medium. Additional injection nozzles 86 may be provided so that live steam is injected along additional locations of the enclosed flow path of the drying medium loop. As illustrated, steam injection along turning elbows of the flow path ductwork are believed particularly useful. Such regions are associated with high turbulence and provide an opportunity to intermix the newly injected live steam with the other components of the drying medium.
[0039] As set forth above, it has been found that live steam may be added to an existing throughair dryer apparatus and process to bring about the stated improvements. It is readily appreciated by one having ordinary skill in the art that as the relative amount of live steam introduced into the drying medium is increased, the relative percentage of drying medium atmospheric oxygen is decreased. Accordingly, as the live steam content of the drying medium is increased, the temperature of the drying medium which may be used without scorching or burning the tissue web also increases. The drying medium may have a free oxygen concentration of less than the ambient oxygen concentration of air of 21%. Optimally, the drying medium has a free oxygen concentration of less than 15% and desirably, less than 10%. It is yet still more desirable to provide a drying medium which is substantially free of atmospheric oxygen.
[0040] With respect to an existing TAD apparatus and process, live steam may be added as a component of the existing drying medium. The introduction of live steam is believed useful in that the energy demands placed upon the electric fans and blowers used to circulate the drying medium will be reduced. The pressurized release of live steam contributes to the displacement and velocity of the drying medium. Further, the increased temperature of the drying medium permits a more efficient drying of the associated web. As such, the improved efficiency may permit a more rapid throughput of the web through the throughair dryer process or allow a reduction in the drying medium volume and/or flow rate, either of which would also contribute to overall cost savings of operation.
[0041] It is also possible to provide a throughair dryer and process in which the TAD uses a drying medium of substantially 100 percent live steam. As such, the throughair drying medium is substantially free of atmospheric oxygen which allows the web to be raised to much greater temperatures which, heretofore, would have resulted in a scorching or burning of the fabric web.
[0042] In certain embodiments of this invention, it is envisioned that the requirement of motorized blowers and fans may be substantially reduced in terms of size and capacity or eliminated altogether from the system. In their place, the circulation pathway of the drying medium loop can be established and maintained through the pressurized release of steam.
[0043] In one embodiment of the present invention, an apparatus and process of oxygen-free drying is disclosed. While this embodiment discloses the use of substantially 100 percent steam as the drying medium, it is possible that other inert gases could be used in combination with the live steam. Such a use is envisioned within the scope of applicants' substantially oxygen-free drying process.
[0044] Although various embodiments of the invention have been described using specific terms, devices, and methods, such description is for illustrative purposes only. The words used are words of description rather than of limitation. It is to be understood that changes and variations may be made by those of ordinary skill in the art without departing from the spirit or scope of the present invention, which is set forth in the following claims. In addition, it should be understood that aspects of the various embodiments may be interchanged, both in whole or in part. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained therein.
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A paper web drying apparatus and process is provided in which the heated air drying medium is replaced with between 10 percent to 100 percent of live steam. The addition of a steam component to the drying medium provides for a higher drying temperature to be supplied to the wet moving web. The introduction of live pressurized steam contributes to the load of force of the drying medium, thereby decreasing the energy requirements of blower motors. The introduction of pressurized live steam also lowers the free atmospheric oxygen content of the drying medium which reduces the burning or scorch hazard associated with high temperature drying of a cellulose web.
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BACKGROUND
The present disclosure is directed to wellbore lithology fractionation technology, more particularly to fracture characterization using reservoir monitoring devices, and more particularly, but not by way of limitation, to a system and method for using several sensors attached below a fracturing tool string.
A wide variety of downhole tools may be used within a wellbore in connection with producing hydrocarbons from a hydrocarbon formation. Downhole tools such as frac plugs, bridge plugs, and packers, for example, may be used to seal a component against casing along the wellbore wall or to isolate one pressure zone of the formation from another.
Fracturing is a wellbore service operation to break or fracture a production layer with the purpose of improving flow from that production layer. In the case that multiple zones of production are planned, fracturing may be conducted as a multi-step operation, for example positioning fracturing tools in the wellbore to fracture a first zone, pumping fracturing fluids into the first zone, repositioning the fracturing tools in the wellbore to fracture a second zone, pumping fracturing fluids into the second zone, and repeating for each of the multiple zones of production. Fracturing fluids sometimes propagate into water bearing formations, which is undesirable. Water must be separated at the surface from oil or gas and properly disposed of, imposing undesirable expenses on the production operation. If the production fluids are pumped to the surface, pumping energy, and hence money, is expended lifting the waste water product to the surface. What is needed is a system and method to detect during the course of a fracturing job when the fracturing fluid is propagating into a water bearing formation so that the fracturing job may be interrupted.
Fracturing tools may be withdrawn from the wellbore, and sensors may then be deployed into the wellbore and used to directly sense the results of fracturing. The sensors are withdrawn from the wellbore, the sensor information they have stored is downloaded to a computer, and the data is analyzed for use in planning future fracturing jobs in similar lithology structures or similar production fields. This two trip process is undesirable. What is needed is a system and method for co-deployment and co-retraction of fracturing tools and sensors for a fracturing service operation which may reduce the number of tool string trips into and out of the wellbore.
SUMMARY
Disclosed herein is a system for monitoring a wellbore service treatment, comprising a downhole tool operable to perform the wellbore service treatment; a conveyance connected to the downhole tool for moving the downhole tool in the wellbore, and a plurality of sensors operable to provide one or more wellbore indications and attached to the downhole tool or a component thereof via one or more tethers.
Further disclosed herein is a method of monitoring a wellbore service treatment, comprising conveying into a wellbore a downhole tool operable to perform the wellbore service treatment and a plurality of sensors operable to provide one or more wellbore indications attached to the downhole tool or a component thereof via one or more tethers, deploying the downhole tool at a first position in the wellbore for service, treating the wellbore at the first position; and monitoring an at least one wellbore indication provided by the wellbore sensors at the first position.
These and other features and advantages will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present disclosure and the advantages thereof, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description, wherein like reference numerals represent like parts.
FIG. 1 a depicts a wellbore and a first tool string in a first stage of a fracturing job.
FIG. 1 b depicts a wellbore and a first tool string in a second stage of a fracturing job.
FIG. 1 c depicts a wellbore and a first tool string in a third stage of a fracturing job.
FIG. 1 d depicts a second tool string and fracturing configuration.
FIG. 1 e depicts a third tool string and fracturing configuration.
FIG. 1 f depicts a fourth tool string and fracturing configuration.
FIG. 1 g depicts a fifth tool string and fracturing configuration.
FIGS. 1 h and 1 i depict a sixth tool string and fracturing configuration.
FIG. 2 a illustrates a group of tiltmeters tethered together and hanging under a fracturing plug.
FIG. 2 b illustrates a group of tiltmeters attached to wellbore casing.
FIG. 2 c illustrates a group of tiltmeters each tethered separately to a fracturing plug.
FIG. 3 a depicts a data recovery component.
FIG. 3 b depicts an embodiment for tethering a sensor.
FIG. 4 is a flow chart illustrating a first method for monitoring a wellbore service treatment.
FIG. 5 is a flow chart illustrating a second method for monitoring a wellbore service treatment.
FIG. 6 is a flow chart illustrating a third method for monitoring a wellbore service treatment.
DETAILED DESCRIPTION
It should be understood at the outset that although an exemplary implementation of one embodiment of the present disclosure is illustrated below, the present system may be implemented using any number of techniques, whether currently known or in existence. The present disclosure should in no way be limited to the exemplary implementations, drawings, and techniques illustrated below, including the exemplary design and implementation illustrated and described herein.
FIGS. 1 a , 1 b , and 1 c show a wellbore 10 , which may be cased or uncased, and three stages of a wellbore service job corresponding to a first wellbore service configuration, in FIG. 1 a , a second wellbore service configuration, in FIG. 1 b , and a third wellbore service configuration, in FIG. 1 c . The exemplary wellbore service job depicted is a fracturing service job, but the present disclosure contemplates other wellbore service jobs such as acidizing, gravel packing, cementing, perforating, logging, conducting a survey to collect data, placing downhole sensors, installing and shifting the position of gas lift valves and flow valves, and other wellbore service jobs known to those skilled in the art. The exemplary fracturing job is directed to improving the flow from a zone of interest 14 . In an embodiment shown in FIGS. 1 a - c , a first tool string 8 comprises a bridge plug 16 and a plurality of sensors 18 —a first sensor 18 a , a second sensor 18 b , a third sensor 18 c , and a fourth sensor 18 d —attached to and hanging from the bridge plug 16 . The sensors 18 may be referred to as a sensor array or an array of sensors.
The bridge plug 16 may be generically referred to as a downhole tool. A wide variety of downhole tools may be used within a wellbore in connection with producing hydrocarbons from a hydrocarbon formation. Downhole tools such as frac plugs, bridge plugs, and packers, for example, may be used to seal a component against casing along the wellbore wall or to isolate one pressure zone of the formation from another. In addition, perforating guns may be used to create perforations through casing and into the formation to produce hydrocarbons. Downhole tools are typically conveyed into the wellbore on a wireline, tubing, pipe, or another type of cable. The first tool string 8 provides for the co-deployment and co-retraction of the bridge plug 16 and the sensors 18 using a tubing 20 .
The bridge plug 16 is an isolation tool that is operable to shut the well in, to isolate the zones above and below the bridge plug 16 , and to allow no fluid communication therethrough. The bridge plug 16 may be referred to as a sealable member. The sensors 18 may be tiltmeters, geophones, pressure sensors, temperature sensors, combinations thereof, or other sensors operable to sense wellbore characteristics which are known to those skilled in the art. The sensors 18 may each be supported by an individual or dedicated link or tether to the bridge plug 16 as shown in FIG. 2 c . Alternately, the sensors 18 may be chained or linked together, as shown in FIGS. 2 a and 2 b , wherein sensor 18 d is supported by a link or tether to sensor 18 c , sensor 18 c is supported by a link or tether to sensor 18 b , sensor 18 b is supported by a link or tether to sensor 18 a , and sensor 18 a is supported by a link or tether to the bridge plug 16 . While in this exemplary case four sensors 18 are shown to be employed, in other wellbore service jobs either more or fewer sensors 18 may be employed, for example 1 or more. The embodiments of FIGS. 2 a - c may be used with any of the tool string embodiments disclosed herein.
In the first wellbore service configuration of FIG. 1 a , the first tool string 8 has been lowered into the wellbore 10 , below the zone of interest 14 , via a tubing 20 . In another embodiment, the first tool string 8 may be conveyed into the wellbore 10 using wireline, slickline, coiled tubing, jointed tubing, or another conveyance known to those skilled in the art. The bridge plug 16 is placed to seal a lower boundary of the zone of interest 14 .
In the second wellbore service configuration of FIG. 1 b , the tubing 20 has been detached from the bridge plug 16 and withdrawn from the wellbore 10 . A stimulation service pump 22 is connected to a wellhead 24 and provides a fracturing fluid or other wellbore servicing fluid at a desirable pressure, temperature, and flow rate into the wellbore 10 . The fracturing fluid flows down the wellbore 10 , through wellbore casing perforations, into the zone of interest 14 . In an alternative embodiment as shown in FIGS. 1 h and 1 i , the tubing may remain attached to the sealable member 19 , e.g., a packer, and the fracturing fluid may be pumped via one or more stimulation service pumps 22 into the zone of interest 14 via an internal flow path 21 inside the tubing 20 , via a flow path 23 in the annular space between the outer wall of tubing 20 and the inside wall of the wellbore 10 , or via both. The fracturing fluid may contain proppants or sand. A fracturing effect 26 is represented by an ellipse. During the course of the fracturing, or other wellbore service job, the sensors 18 collect data on conditions in the wellbore 10 . Hanging off of the bridge plug 16 or sealable member 19 , the sensors 18 are out of the flow of fracturing fluid and hence are not subject to possibly damaging ablation which may occur if proppants are employed.
In the third wellbore service configuration in FIG. 1 c , the tubing has been run back into the wellbore 10 , the tubing 20 has been reattached to the bridge plug 16 , the bridge plug 16 has been disengaged from the wellbore casing, and the tubing 20 is shown withdrawing the first tool string 8 from the wellbore 10 . Alternatively, prior to withdrawing the tool string from the wellbore, the tool string may be redeployed and the treatment steps repeated to fracture multiple zones or intervals. For example, as shown in FIGS. 1 h and 1 i , multiple zones or intervals 14 a and 14 b within the wellbore 10 may be fractured. While two zones are show in FIGS. 1 h and 1 i , it should be understood that more than two zones may be treated in a multi-stage job, and preferably the zones are perforated sequentially starting at the bottom zone and working upward. As shown in FIG. 1 h the downhole tool is run into the wellbore via tubing 20 and the sealing member 19 , e.g., a packer, is set. An array of sensors 18 a - d is tethered to and hangs from the bottom of packer. If not already present, perforations 25 are formed by a perforating component of the downhole tool, for example a hydra-jetting tool or a perforating gun. A treatment fluid such as a fracturing fluid may be pumped, for example via the annular flow path 23 , the flow path 21 inside the tubing, or both, though the perforations 25 and into the formation, thereby creating a fracturing effect 26 . Upon completion of the fracturing, for example as determined via data provided by the sensor array 18 a - d , the packer may be repositioned and reset and additional zones may be treated as shown in FIG. 1 i.
When the first tool string 8 is removed from the wellbore 10 , the sensors 18 may be operably coupled to a monitoring computer to download the data collected by the sensors 18 during the wellbore service job. The sensor data may be analyzed to model the effect of the fracture job and to adjust fracturing parameters for future fracture jobs in similar lithology. The co-deployment and co-retrieval of the bridge plug 16 and the sensors 18 saves extra trips into the wellbore 10 to deploy and retract the sensors 18 .
Turning now to FIG. 1 d , a second tool string 101 is shown comprising a packer 102 , a tool body 104 , a plurality of jets 106 , the bridge plug 16 , and the plurality of sensors 18 in a fourth wellbore service configuration 100 a . The second tool string 101 may be generically referred to as a downhole tool. The packer 102 seals between two areas of the wellbore 10 and contains a valve or conduit therethrough that permits fluid flow in one direction, as shown with arrows, when desirable. The packer 102 may be referred to as a sealable member. The jets 106 are a plurality of orifices in the tool body 104 wherefrom fracturing fluid flows under pressure. In some embodiments, the jets 106 may be inserts which are formed of special materials that resist erosion. The second tool string 101 is attached to the tubing 20 via a connector 108 . The second tool string 101 is shown after having placed the bridge plug 16 to seal a lower boundary of the zone of interest 14 , having disconnected from the bridge plug 16 , having withdrawn from the bridge plug 16 , and having placed the packer 102 to seal an upper boundary of the zone of interest 14 . The use of the packer 102 and the bridge plug 16 confines the fracture fluid and pressure to the region between the packer 102 and the bridge plug 16 , which may be useful when fracturing a wellbore 10 having multiple zones of interest 14 and/or multiple sets of perforations.
A fracturing job is shown in progress, with fracturing fluid, which may contain proppants, being pumped down the tubing 20 , through the tool body 104 , out of the jets 106 , into the zone of interest 14 . The sensors 18 hang down from the packer 102 , out of the path of fracturing fluid flow, for example as shown in FIGS. 2 a and 2 b . In an embodiment, the sensors 18 may attach themselves to the wellbore wall as in FIG. 2 b , for example tiltmeters using magnetism to attach to a wellbore casing wall. In an embodiment according to FIG. 3 , the data recovery component 60 may be employed to provide electrical power to and receive data from the sensors 18 and may be located above the packer 102 .
Turning now to FIG. 1 e , a third tool string 120 is shown comprising the packer 102 , the tool body 104 , the jets 106 , the bridge plug 16 , and the plurality of sensors 18 in a fifth wellbore service configuration 100 b . The third tool string 120 may be generically referred to as a downhole tool. The third tool string 120 is attached to the tubing 20 via the connector 108 . The third tool string 120 is shown after having placed the bridge plug 16 to seal a lower boundary of the zone of interest 14 , having disconnected from the bridge plug 16 , having withdrawn from the bridge plug 16 , and having placed the packer 102 to seal an upper boundary of the zone of interest 14 . The use of the packer 102 and the bridge plug 16 confines the fracture fluid and pressure to the region between the packer 102 and the bridge plug 16 , which may be useful when fracturing a wellbore 10 having multiple zones of interest 14 and/or multiple sets of perforations.
A fracturing job is shown in progress, with fracturing fluid, which may contain proppants, being pumped down the tubing 20 , through the tool body 104 , out of the jets 106 , into the zone of interest 14 . The sensors 18 hang above the packer 102 , out of the path of fracturing fluid flow, suspended in the wellbore fluid due to buoyancy or through the action of a propulsion action. In an embodiment, the sensors may attach themselves to the wellbore wall as in FIG. 2 b , for example tiltmeters using magnetism to attach to a wellbore casing wall. In an embodiment according to FIG. 3 , the data recovery component 60 may be employed to provide electrical power to and receive data from the sensors 18 and may be located above the packer 102 .
Turning now to FIG. 1 f , a fourth tool string 140 is shown comprising the packer 102 , the tool body 104 , the jets 106 , the bridge plug 16 , and the sensors 18 in a sixth wellbore service configuration 100 c . The fourth tool string 140 may be generically referred to as a downhole tool. The fourth tool string 140 is attached to the tubing 20 via the connector 108 . The fourth tool string 140 is shown after having placed the bridge plug 16 to seal a lower boundary of the zone of interest 14 and having placed the packer 102 to seal an upper boundary of the zone of interest 14 . The use of the packer 102 and the bridge plug 16 confines the fracture fluid and pressure to the region between the packer 102 and the bridge plug 16 , which may be useful when fracturing a wellbore 10 having multiple zones of interest 14 and/or multiple sets of perforations.
A fracturing job is shown in progress, with fracturing fluid, which may contain proppants, being pumped down the tubing 20 , through the tool body 104 , out of the jets 106 , into the zone of interest 14 . The sensors 18 hang below the bridge plug 16 , out of the path of fracturing fluid flow, for example as shown in FIGS. 2 a and 2 b . In an embodiment, the sensors may attach themselves to the wellbore wall as in FIG. 2 b , for example tiltmeters using magnetism to attach to a wellbore casing wall. In an embodiment according to FIG. 3 , the data recovery component 60 may be employed to provide electrical power to and receive data from the sensors 18 and may be located below the bridge plug 16 .
Turning now to FIG. 1 g , a fifth tool string 160 is shown comprising the packer 102 , the tool body 104 , the jets 106 , the bridge plug 16 , and the sensors 18 in a seventh wellbore service configuration 100 d . The fifth tool string 160 may be generically referred to as a downhole tool. The fifth tool string 160 is attached to the tubing 20 via the connector 108 . The fifth tool string 160 is shown after having placed the bridge plug 16 to seal a lower boundary of the zone of interest 14 , having disconnected from the bridge plug 16 , having withdrawn from the bridge plug 16 , and having placed the packer 102 to seal an upper boundary of the zone of interest 14 . The use of the packer 102 and the bridge plug 16 confines the fracture fluid and pressure to the region between the packer 102 and the bridge plug 16 , which may be useful when fracturing a wellbore 10 having multiple zones of interest 14 and/or multiple sets of perforations.
A fracturing job is shown in progress, with fracturing fluid, which may contain proppants, being pumped down the tubing 20 , through the tool body 104 , out of the jets 106 , into the zone of interest 14 . The sensors 18 hang below the bridge plug 16 , out of the path of fracturing fluid flow, for example as shown in FIGS. 2 a and 2 b . In an embodiment, the sensors may attach themselves to the wellbore wall as in FIG. 2 b , for example tiltmeters using magnetism to attach to a wellbore casing wall. In an embodiment according to FIG. 3 , the data recovery component 60 may be employed to provide electrical power to and receive data from the sensors 18 and may be located below the bridge plug 16 .
Each of the tool strings may be referred to generally as a downhole tool. While the exemplary wellbore service jobs described above referred to using a bridge plug 16 and a packer 102 in various tool string configurations, those skilled in the art will readily appreciate that other sealable members may be employed to conduct fracturing wellbore service jobs as well as other wellbore service jobs. Other dispositions of the sensors 18 out of the flow of fracture fluid are also contemplated by this disclosure.
Turning now to FIG. 2 a , the first tool string 8 is shown in the wellbore 10 with six tiltmeters (or other appropriate sensors)—a first tiltmeter 50 a , a second tiltmeter 50 b , a third tiltmeter 50 c , a fourth tiltmeter 50 d , a fifth tiltmeter 50 e , and a sixth tiltmeter 50 f -attached to and hanging below the bridge plug 16 , not attached to the wellbore 10 . The first tiltmeter 50 a is attached to the bridge plug 16 by a first link 52 a . The second tiltmeter 50 b is attached to the first tiltmeter 50 a by second link 52 b . The third tiltmeter 50 c is attached to the second tiltmeter 50 b by a third link 52 c . The fourth tiltmeter 50 d is attached to the third tiltmeter 50 c by a fourth link 52 d . The fifth tiltmeter 50 e is attached to the fourth tiltmeter 50 d by a fifth link 52 e . The sixth tiltmeter 50 f is attached to the fifth tiltmeter 50 e by a sixth link 52 f.
Turning now to FIG. 2 b , the wellbore 10 is shown with the tiltmeters 50 a - f attached to the wellbore casing and with desirable slack in each of the links 52 a - f . The slack in each of the links 52 a - f mechanically isolates the tiltmeters 50 a - f from one another and from the bridge plug 16 . The slack may be imparted to the links 52 a - f by performing a maneuver wherein the bridge plug 16 is lowered more quickly than the tiltmeters 50 a - f can fall in suspension in the fluid in the wellbore 10 , the tiltmeters 50 a - f are attached to the wellbore 10 , and the bridge plug 16 deploys and seals the wellbore 10 . The tiltmeters 50 a - f may be designed to deploy a drag structure and/or to increase their buoyancy whereby to slow the descent of the tiltmeters 50 a - f in the fluid in the wellbore 10 . The drag structure also may be employed to orient the tiltmeters 50 a - f and to steer them towards the wellbore casing where the tiltmeters 50 a - f may attach to the wellbore casing, for example employing magnets.
In another embodiment, the tiltmeters 50 a - f may hang in tension, suspended by the links 52 a - f and simultaneously attached to the wellbore casing without slack in the links.
The links 52 a - f may be chain links; rope wire, or cable tethers; bands, or data transmission cables formed of metal, plastic, rubber, ceramic, composite materials, or other materials known to those skilled in the art. The sensors 50 a - f may separate the links 52 a - f , forming part of the weight bearing structure supporting sensors located below. Alternately, the links 52 a - f may form a continuous chain or tether, and sensors 50 a - f may be attached thereto without forming part of the weight bearing structure. The links 52 a - f may also serve as data communication pathways between the sensors 50 a - f and a memory module 60 , as in FIG. 3 a.
The discussion of how the sensors 50 a - f are suspended from the bridge plug 16 and attached to the wellbore casing also applies to the alternative tool strings illustrated in FIGS. 1 d - i.
Turning now to FIG. 3 a , in some embodiments of the first tool string 8 a data recovery component 60 may attached as shown to the bottom of the bridge plug 16 . The data recovery component 60 comprises a battery 62 and a memory tool 64 . The battery 62 provides electrical power via a first cable 66 a to the first sensor 18 a . The memory tool 64 communicates with and receives data from the first sensor 18 a through the first cable 66 a and stores this data, to be downloaded by a monitoring computer at the surface when the first tool string 8 is withdrawn from the wellbore 10 . In some embodiments, the memory tool 64 may provide data collection commands, data collection timing signals, and or excitation signals to the sensors 18 through the first cable 66 a.
The memory tool 64 may be a data recording device such as for example a microcontroller/microprocessor associated with a memory and operable to receive and store data from the sensors 18 . Electrical power is provided to and data is returned from each of the sensors 18 through a path comprising the first cable 66 a , the first sensor 18 a , a second cable 66 b attached between the first sensor 18 a and the second sensor 18 b , the second sensor 18 b , a third cable 66 c attached between the second sensor 18 b and the third sensor 18 c , the third sensor 18 c , a fourth cable 66 d attached between the third sensor 18 c and the fourth sensor 18 d , and the fourth sensor 18 d.
A first chain 68 a is shown supporting the weight of the sensors 18 . The first chain 68 a is shown attached to the data recovery component 60 , but in some embodiments the first chain 68 a may attach to the bridge plug 16 . A second chain 68 b , a third chain 68 c (not shown), and a fourth chain 68 d (not shown) are interconnected through the bodies of the sensors 18 and support the weight of the sensors 18 . In an alternate embodiment as shown in FIG. 3 b , the chains 68 attach to each other to form a continuous chain and the sensors attach thereto via attachment 69 without bearing any of the weight. The chains 68 may be constructed of metal, plastic, ceramic, or other materials. Support linkages other than chain also are contemplated, such as a flexible chord.
In some embodiments, the cable 66 and the chain 68 attached to each sensor 18 may attach directly to the data recovery component 60 . In an embodiment, the cable 66 may be a continuous cable with Tee-like drop connections provided along the length of the continuous cable for coupling to the sensors 18 . In some embodiments the cable 66 and the chain 68 may be enclosed in a sheath to prevent entanglements and to protect the cable 66 and chain 68 from hazards in the wellbore 10 . The cable 66 may be interwoven in the chain 68 . In an embodiment, the cable 66 may be integrated with the chain 68 or a tether.
The discussion of the data recovery component 60 also applies to the alternative tool strings illustrated in FIGS. 1 d - i.
In some embodiments, a communication path may be provided between the surface and the downhole tool 16 and/or the sensors 18 . The communication path may be contained by the tubing, for example provided by a cable inside or embedded in the walls of the tubing 20 . In addition to or alternatively, the communication path may be provided by a wireless link such as radio link, an optical link, and/or an acoustic link through the fluid in the wellbore 10 .
A communication path between the surface and the second tool string 101 , the third tool string 120 , and the fourth tool string 140 , for example through a cable inside or embedded in the walls of the tubing 20 to a monitoring computer located at the surface, may be provided by the tubing 20 . This capability, which may be termed a real-time fracture monitoring capability or near real-time fracture monitoring capability, could be employed to monitor a wellbore servicing operation such as detecting pumping of fracturing fluid into a water bearing formation. Pumping fracturing fluid into a water bearing formation increases flow of water, which is generally not desirable. Being able to detect this event permits stopping the fracturing job and minimizing the fracturing of the water bearing formation. Additionally, this real-time or near real-time fracture monitoring capability may be employed to adaptively control the fracture job, such as stopping pumping of fracturing fluid after data from the sensors 18 fed into a fracture model generated by the monitoring computer indicates an optimal fracture stage has been arrived at.
In an embodiment, an acoustic communication link between the surface and the first tool string 8 , such as using hydraulic telemetry, may be established. This communication link may be used to monitor fracturing processes while fracturing is in progress as described above.
In one embodiment, a communication path between the surface and the fifth tool string 160 by providing a connectionless communication link between the bridge plug 16 and the packer 102 and by providing a connected communication link, for example a wire cable within the tubing 20 , from the packer 102 to the surface. The connectionless communication link may be provided by a radio link, an optical link, or an acoustic link, such as using hydraulic telemetry, through the fluid between the bridge plug 16 and the packer 102 . The communication path between the bridge plug 16 and the surface may support the ability to monitor fracturing processes while fracturing is in progress as described above.
In other embodiments, a combination of these communication link technologies may be employed to provide the ability to monitor fracturing processes or other wellbore service operations in real-time or near real-time.
Turning now to FIG. 4 , a flow chart is shown of a first method for using the various tool strings of the present disclosure such as shown in FIGS. 1 a - c . The first method begins at block 200 where a sealing member such as the bridge plug 16 or a packer, the sensors 18 , and the tubing 20 are co-deployed downhole. The first method proceeds to block 202 where the bridge plug 16 is seated in the wellbore casing and seals the wellbore 10 below the bridge plug 16 from the wellbore 10 above the bridge plug 16 . The first method proceeds to block 204 where the tubing 20 detaches from the bridge plug 16 . The first method proceeds to block 206 where the tubing 20 is retracted from the wellbore 10 .
The first method proceeds to block 208 where a wellbore service procedure such as a fracturing job is conducted. This involves pumping fracturing fluid down the wellbore 10 at the appropriate pressure, temperature, and flow rate with the appropriate mix of materials, such as proppants and fluids. The parameters for a specific fracturing job are engineered for a specific lithology or field based on experience and data obtained during previous fracture jobs, as is well known to those skilled in the art. Upon completion of pumping, the first method proceeds to block 210 where the tubing 20 is deployed into the wellbore 10 and reattaches to the bridge plug 16 .
The first method proceeds to block 212 where the bridge plug 16 detaches from the wellbore casing. The first method proceeds to block 214 where the tubing 20 is retracted from the wellbore 10 , drawing out with it the bridge plug 16 and the sensors 18 .
The first method proceeds to block 216 where the data collected by the sensors 18 is downloaded to a first computer system. The first method proceeds to block 218 where the data downloaded from the sensors is employed to characterize the fracture job by modeling on a second computer system. This first and second computer systems may be the same computer, or they may be different computers. The characterization of the fracture job of block 218 may occur at the location of the wellbore 10 or it may occur away from the location of the wellbore 10 , for example at a headquarters or at an office.
Observe that the first method described above saves extra trips into the wellbore 10 to deploy and retrieve the sensors 18 , for example using a wireline equipment. In the first method the sensors 18 are co-deployed and co-retracted with the bridge plug 16 .
Turning now to FIG. 5 , a flow chart is shown of a second method for using the various tool strings of the present disclosure such as is shown in FIGS. 1 h and 1 i . The second method is related to the first method but is different by providing fracturing of multiple zones within the wellbore 10 . The second method begins at block 220 where a sealing member such as the bridge plug 16 or a packer, the sensors 18 , and the tubing 20 are co-deployed downhole. The second method proceeds to block 221 where the bridge plug 16 is seated in the wellbore casing and seals the wellbore 10 below the bridge plug 16 from the wellbore 10 above the bridge plug 16 ; where the tubing 20 detaches from the bridge plug 16 ; and where the tubing 20 is retracted from the wellbore 10 .
The first method proceeds to block 222 where a wellbore service procedure such as a fracturing job is conducted. This involves pumping fracturing fluid down the wellbore 10 at the appropriate pressure, temperature, and flow rate with the appropriate mix of materials, such as proppants and fluids. The parameters for a specific fracturing job are engineered for a specific lithology or field based on experience and data obtained during previous fracture jobs, as is well known to those skilled in the art. Upon completion of pumping, the second method proceeds to block 223 where the tubing 20 is deployed into the wellbore 10 , the tubing 20 reattaches to the bridge plug 16 , and the bridge plug 16 detaches from the wellbore casing.
The second method proceeds to block 224 where if another zone of the wellbore 10 remains to be fractured, the second method proceeds to block 225 . In block 225 the bridge plug 16 and sensors 18 are repositioned to fracture the next zone of the wellbore 10 , for example at a position further out of the wellbore 10 . The second method proceeds to block 221 . By repeatedly looping through blocks 221 , 222 , 223 , 224 , and 225 multiple zones of the wellbore 10 may be fractured. Note that the sensors 18 attached to the bridge plug 16 are not deployed into and retracted from the wellbore 10 between each of the fracturing operations, thus saving numerous extra trips into and out of the wellbore 10 . The sensors 18 detect, collect, and store data for each of the multiple fracturing operations.
In block 224 if no additional zones of the wellbore 10 remain to be fractured, the second method proceeds to block 226 where the tubing 20 is retracted from the wellbore 10 , drawing out with it the bridge plug 16 and the sensors 18 .
The second method proceeds to block 227 where the data collected by the sensors 18 is downloaded to a first computer system. The second method proceeds to block 228 where the data downloaded from the sensors is employed to characterize the multiple fracture jobs by modeling on a second computer system. This first and second computer systems may be the same computer, or they may be different computers. The characterization of the fracture job of block 228 may occur at the location of the wellbore 10 or it may occur away from the location of the wellbore 10 , for example at a headquarters or at an office.
Observe that the second method described above saves multiple extra trips into the wellbore 10 to deploy and retrieve the sensors 18 , for example using wireline equipment. In the second method the sensors 18 are co-deployed and co-retracted with the bridge plug 16 .
Turning now to FIG. 6 , a flow chart is shown of a third method for using the various tool strings of the present disclosure such as second tool string 101 , the third tool string 120 , the fourth tool string 140 , or the fifth tool string 160 . The third method begins at block 230 where a sealing member such as the bridge plug 16 or a packer, the sensors 18 , the first tool string 101 , and the tubing 20 are deployed into the wellbore 10 . The third method proceeds to block 232 where the bridge plug 16 is seated in the wellbore casing and seals the wellbore 10 below the bridge plug 16 from the wellbore 10 above the bridge plug 16 .
The third method proceeds to block 234 where a fracturing job is started. This involves pumping fracturing fluid down the wellbore 10 at the appropriate pressure, temperature, and flow rate with the appropriate mix of materials, such as proppants and fluids, as is well known to those skilled in the art.
The third method proceeds to block 236 where the sensors 18 are monitored at the surface by a first computer system. The monitoring includes gathering data from each of the sensors 18 and analyzing the gathered data. Analysis may include feeding the gathered data into a fracture model which predicts fracture progress based on a history of sensor data. The results of the analyzing the gathered data provides input to fracture job operators making a decision to continue pumping fracturing fluid, to stop pumping fracturing fluid, and perhaps to change the material mix of the fracturing fluid or other fracture job parameters such as pressure, temperature, and flow rate.
In an embodiment, in block 236 the pumping of fracturing fluid into the wellbore is completely ceased. Substantial vibration may be produced in the wellbore by the pumping of fracturing fluid, and this vibration may interfere with the sensors 18 monitoring the progress of the fracturing job. In another embodiment, in block 236 the pumping of fracturing fluid continues.
The third method proceeds to block 238 where if the fracturing fluid is not being pumped into a water bearing formation the third method proceeds to block 240 . In block 240 , if the fracture job is not complete, the third method returns to block 234 and the fracture job continues.
If in block 238 the fracturing fluid is being pumped into a water bearing formation the third method proceeds to block 242 . Similarly, if in block 240 the fracturing job is complete the third method proceeds to block 242 . In block 242 the pumping of fracturing fluid is stopped. The third method proceeds to block 244 where the bridge plug 16 detaches from the wellbore casing, and the tubing 20 is retracted from the wellbore 10 , drawing out with it the first tool string 101 , the bridge plug 16 , and the sensors 18 .
Observe that the third method described above saves extra trips into the wellbore 10 to deploy and retrieve the sensors 18 , for example using wireline equipment. In the third method the sensors 18 are co-deployed with the first tool string 101 or with the bridge plug 16 and co-retracted with the first tool string 101 or with the bridge plug 16 . Additionally, the third method permits on-location adaptation of fracture job plans to better accord with the circumstances detected, in real-time or near real-time, by the sensors 18 .
While several embodiments have been provided in the present disclosure, it should be understood that the disclosed systems and methods may be embodied in many other specific forms without departing from the spirit or scope of the present disclosure. The present examples are to be considered as illustrative and not restrictive, and the intention is not to be limited to the details given herein, but may be modified within the scope of the appended claims along with their full scope of equivalents. For example, the various elements or components may be combined or integrated in another system or certain features may be omitted, or not implemented.
Also, techniques, systems, subsystems and methods described and illustrated in the various embodiments as discreet or separate may be combined or integrated with other systems, modules, techniques, or methods without departing from the scope of the present disclosure. Other items shown as directly coupled or communicating with each other may be coupled through some interface or device, such that the items may no longer be considered directly coupled to each but may still be indirectly coupled and in communication with one another. Other examples of changes, substitutions, and alterations are ascertainable by one skilled in the art and could be made without departing from the spirit and scope disclosed herein.
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A system for monitoring a wellbore service treatment, comprising a downhole tool operable to perform the wellbore service treatment; a conveyance connected to the downhole tool for moving the downhole tool in the wellbore, and a plurality of sensors operable to provide one or more wellbore indications and attached to the downhole tool or a component thereof via one or more tethers. A method of monitoring a wellbore service treatment, comprising conveying into a wellbore a downhole tool operable to perform the wellbore service treatment and a plurality of sensors operable to provide one or more wellbore indications attached to the downhole tool or a component thereof via one or more tethers, deploying the downhole tool at a first position in the wellbore for service, treating the wellbore at the first position; and monitoring an at least one wellbore indication provided by the wellbore sensors at the first position.
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BACKGROUND OF THE INVENTION
It is known to those skilled in the art that the amination of 4,5-dichloro-2-phenyl-3(2H)-pyridazinone leads through the two simultaneous reactions: ##STR1## to the formation of commercial PYRAZON, that is a product constituted by a mixture of two isomers, one of which, 5-AMINO-4-CHLORO-2-PHENYL-3(2H)-PYRIDAZINONE (also referred to hereinafter by the abbreviation PCA) is active as a selective weed-killer for agricultural use while the second, 4-AMINO-5-CHLORO-2-PHENYL-3(2H)-PYRIDAZINONE (also referred to hereinafter by the abbreviation ISO-PCA) does not have any herbicidal activity (and the presence of which is therefore superfluous, if not harmful, when it is applied to the soil together with the first).
SUMMARY OF THE INVENTION
The main object of the present invention is to obtain improved herbicidal compositions for agricultural use having superior properties to those currently in use and, to this end, to obtain the isomer (PCA) which is active as a selective herbicide or weed-killer practically free from the inactive isomer (ISO-PCA).
This object is achieved by means of the present invention by making use of the property, which is totally unexpected and not known from the chemical literature, that in mineral acids, such as hydrochloric and sulphuric acid, of suitable concentration a distinct diversity of solubility of the two isomers PCA and ISO-PCA occurs.
On the basis of this property, the present invention provides a process for obtaining 5-amino-4-chloro-2-phenyl-3(2H)-pyridazinone (PCA) free from 5-chloro-4-amino-2-phenyl-3(2H)-pyridazinone (ISO-PCA) from commercial Pyrazon, that is from a mixture of the said two isomeric compounds, which is characterized in that commercial Pyrazon is treated with a mineral acid of suitable concentration, a suspension being obtained, and the suspension obtained is filtered to derive the desired product (PCA).
The mineral acid employed will preferably be hydrochloric acid with a concentration higher than 30% or sulphuric acid with a concentration higher than 60%, either in a proportion preferably of 1:2.5 weight/volume between the commercial Pyrazon and the mineral acid in solution.
By this process the product 5-amino-4-chloro-2-phenyl-3(2H)-pyridazinone free from the isomer 4-chloro-5-amino-2-phenyl-3(2H)-pyridazinone is obtained with a melting point of 204°-206° C. This product proves unexpectedly to be of a toxicity lower than that of the mixture of the two starting isomers. In fact, tests carried out have shown that the product obtained by means of the present invention has a
LD 50:4110 mg/kg in rats
against
LD 50:2292 mg/kg in rats
of the starting commercial Pyrazon.
It is considered preferable that the process according to the invention will also include the additional stage of recovering the isomer (ISO-PCA) remaining in solution by means of dilution of the mother filtration liquors with water in the proportion of 1:1 and subsequent filtration of the diluted solution.
To obtain improved herbicidal compositions, the present invention provides for a suitable formulation of herbicidal compositions containing as active substance the isomer (PCA) obtained by the above-claimed process. These compositions may be in the form of wettable powders or water-dispersible pastes or of microgranules and will be used in agriculture especially on crops of beetroot and sugar beet in pre-sowing, pre-emergence and post-emergence treatments.
In fact, experiments carried out for the selective eradication of weeds from agricultural crops, and in particular sugar beet, have enabled it to be ascertained unexpectedly that herbicidal formulations containing pure PCA have, with respect to those containing the mixture of the two isomers, a greater effectiveness on infesting plants and a lesser phytotoxicity for the crops, especially if they are used in postemergence treatments.
The possibility of producing herbicidal compositions containing pure PCA which, for equality of organic substance employed, have a greater content of active substance, moreover enables substantial advantages to be obtained from the ecological point of view, inasmuch as it is possible in this case to avoid distributing ISO-PCA, an organic compound useless for practical purposes, over the soil, with a consequent lower pollution of the environment.
Solid economic advantages are also achieved because of the smaller amounts of chemical additives used, without any reduction in the biological efficiency of the herbicidal compositions.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Going back to considering in greater detail the process for obtaining the isomer (PCA) of commercial Pyrazon, the treatment of the starting mixture with mineral acid will be examined.
If the mixture of isomers, PCA and ISO-PCA, which forms commercial Pyrazon is treated with hydrochloric acid, it can be established that the concentration of this acid must be higher than 30%: more precisely, fully satisfactory results have been obtained with concentrations ranging between 31% and 37%. In hydrochloric acid of this concentration, in fact, the isomer ISO-PCA dissolves without any difficulty, while the isomer PCA is very little soluble, for which reason it is separated by simple filtration and washing to neutrality.
The separation is so selective that the PCA is obtained with a titre higher than 96% and, by using a suitable ratio of solid/hydrochloric acid, preferably a ratio of 1:2.5 weight/volume, yields higher than 95% are obtained.
The isomer ISO-PCA dissolved in the mother liquors is recovered by dilution with H 2 O and subsequent filtration. If hydrochloric acid with concentrations lower than 30% is used, the titre of the product rapidly gets worse, inasmuch as there is insufficient solubilization of the isomer ISO-PCA.
If the mixture of isomers, PCA and ISO-PCA, which forms commercial Pyrazon is treated with sulphuric acid, it can be established that the concentration of this acid must be higher than 60%: more precisely, the best results have been obtained with concentration ranging between 60% and 75%.
In sulphuric acid of this concentration the isomer ISO-PCA dissolves without any problems, while the isomer PCA is poorly soluble, for which reason it is easily separated by filtration and subsequent washing to neutrality.
With sulphuric acid of the concentration indicated, a product with a titre higher than 96% is obtained and, by using a suitable ratio of solid/sulphuric acid, preferably a ratio of 1:2.5 weight/volume, yields ranging between 85% and 90% are obtained.
If sulphuric acid in concentrations lower than 60% is used, there is a deterioration of the titre of the PCA obtained (inasmuch as there is insufficient solubilization of ISO-PCA), while if the concentration of 75% is exceeded there is a lowering of the yield of purified product (inasmuch as the isomer PCA also tends to dissolve in this case).
Some practical examples for performing the process according to the invention will now be given. These are obviously of a purely indicative nature and do not introduce any limitation of the invention itself.
Example 1 of Process
1000 ml of 32% HCl d=1.16
are placed in a reaction vessel and then, in about half an hour,
400 g of commercial Pyrazon containing 86% of PCA, m.p. 185°-195° C.,
are fed in. Stirring is carried out for 4 to 6 hours at room temperature, the suspension is filtered and washing is carried out with
400 ml of 32% HCl
and then with H 2 O to neutrality. The cake is dried and there is obtained:
340 g of purified PCA with a titre of 97% - m.p.
204°-206° C. Yield in product 100%=96% of the theoretical.
The mother filtration liquors, to which the hydrochloric acid used for washing has been added are diluted with
1400 ml of water.
The mixture is left to be stirred until complete precipitation of the ISO-PCA occurs and then filtration and washing with water to neutrality are carried out.
Example 2 of Process
1000 ml of 32% HCl d=1.16
are placed in a reaction vessel and then, in about half an hour,
400 g of commercial Pyrazon containing 84% of PCA
are added. The procedure carried out is as in Example 1 and there is obtained:
331 g of purified PCA with a titre of 96.5% - m.p. 204°-206° C. Yield in product 100%=95% of the theoretical.
Example 3 of Process
1000 ml of 37% HCl d=1.184
are placed in a reaction vessel and then, in about half an hour,
400 g of commercial Pyrazon containing 86% of PCA are added. Stirring is carried out for 2 to 4 hours at room temperature, the suspension is filtered and washing is carried out with
400 ml of 37% HCl.
The procedure carried out is as in Example 1 and there is obtained:
326 g of purified PCA with a titre of 98%.
Yield in product 100%=93% of the theoretical.
Example 4 of Process
1000 ml of 28% HCl d=1.14
are placed in a reaction vessel and then, in about half an hour,
400 g of commercial Pyrazon containing 86% of PCA are added. Stirring is carried out for 6 hours at room temperature and then the procedure is as in Example 1. There is obtained:
378 g of 89% PCA.
It can be seen clearly how the 28% concentration of the hydrochloric acid is not sufficient to achieve good purification of the commercial Pyrazon.
Example 5 of Process
2000 ml of 32% HCl d=1.16
are placed in a reaction vessel and then, in about half an hour,
400 g of commercial Pyrazon containing 86% of PCA are added. The procedure as in Example 1 is then followed, to obtain:
319 g of purified PCA with a titre of 97%.
Yield in product 100%=90% of the theoretical.
Example 6 of Process
1000 ml of 70% sulphuric acid
are placed in a reaction vessel and then, in about half an hour,
400 g of commercial Pyrazon containing 86% of PCA
are fed in at room temperature. Stirring is carried out for 4 hours at room temperature, the suspension is filtered and washing is carried out with
400 ml of 70% H 2 SO 4
The cake is taken up in water and filtering and washing to neutrality are carried out. After drying there is obtained:
314 g of purified Pyrazon containing 96.5% of PCA
Purification yield: 88% of the theoretical.
Example 7 of Process
The same procedure as in Example 6 is followed, but using
1000 ml of 55% H 2 SO 4 .
There is obtained:
360 g of Pyrazon containing 90% of PCA.
As can be seen, with H 2 SO 4 , of a concentration lower than 60%, a product (PCA) of insufficient purity for the purposes which are proposed here is obtained.
Example 8 of Process
The same procedure as in Example 6 is followed, but using
1000 ml of 80% H 2 SO 4 .
There is obtained:
226 g of purified Pyrazon containing 98.8% of PCA.
Purification yield: 65% of the theoretical.
As can be seen, with H 2 SO 4 of a concentration higher than 75%, a product (PCA) of very high purity is obtained, but the yield is inadequate.
As it has been said, the purified Pyrazon (PCA) is useful for producing improved herbicidal compositions, to prepare which it is expedient that it is formulated in suitable manner by techniques known to those skilled in the art, the compositions being produced either as wettable powder or as water-dispersible paste or else as microgranules.
For wettable powder, it is necessary that after mixing of the active substance and the inert substances they are subjected to grinding with suitable mills (e.g. an air jet mill) so as to obtain formulations having very fine particles, for example with a diameter smaller than 15 microns and, if possible, even smaller than 5 microns.
For water-dispersible paste, after mixing of the active substance and the inert substances, for the most part liquid substances, the composition is subjected to intensive grinding with suitable equipment (for example, in a bead or sand mill) so as to obtain a size of the solid particles which is smaller than 10 microns, if possible smaller than 2 microns. The following Examples relate to the formulation of herbicidal compositions according to the invention and are obviously only of an illustrative and non-limitative nature.
Formulation Example I
A wettable powder containing 77.6% of active substance is prepared by mixing:
______________________________________Purified Pyrazon containing 97% of PCA 80 gSodium lauryl sulphonate 2 gSodium polymethacrylate 2 gSodium lignin sulphonate 2 gKaolin in very fine powder form 3 gColloidal silica 10 gtotal 100 g______________________________________
Formulation Example II
A water-dispersible paste is prepared by mixing:
______________________________________Purified Pyrazon containing 97% of PCA 532 gButyl alcohol condensed with ethylene oxide 80 gHomopolysaccharide 2 gDimethylpolysiloxane 5 gEthylene glycol 70 gDeionised water 311 gtotal 1000 g______________________________________
The effectiveness of the herbicides obtained with the compositions of which the formulation has been discussed hereinbefore can be made clear by considering the results of the following Examples of application, which are also given purely by way of illustration and non-limitatively.
Example of Application I
In a field intended for sowing sugar beet and ready for sowing there are distributed, by spraying with conventional equipment, herbicidal compositions containing either purified Pyrazon containing 97% of PCA or commercial Pyrazon containing 84% of PCA which are formulated both as wettable powders and as water-dispersible pastes as indicated in the foregoing Formulation Examples I and II, in such manner as to employ the same amount of active substance per hectare, as stated in Table I given hereinafter.
After the distribution of the weed-killers or herbicides, they are incorporated in the surface of the soil to a depth of 3 to 4 cm by suitable harrowing (incorporated pre-sowing treatment).
Mechanical sowing of the MARIBO UNICA variety of beet is thereafter effected.
Similarly to the pre-sowing treatment, after sowing, distribution of the same weed-killers is carried out at the same rates of use before emergence of the crop from the surface of the soil (pre-emergence treatment).
The same herbicidal treatments are also effected in this way when the crop has a development of 4 or 5 leaves and the infesting weeds are in a juvenile stage of development.
From the data obtained and given in Table I it can be observed how the formulations containing Pyrazon with 97% of PCA provide optimum results, superior to those obtainable with formulations containing Pyrazon with 84% of PCA, when the two types of formulations are used at equivalent rates of active substance.
In Table I, the numbers relating to the effectiveness or the phytotoxicity have the following significance:
0=No phytotoxicity on the crop or effectiveness on the weeds
100=Total destruction of the crop or the weeds.
Intermediate values represent intermediate levels of effectiveness or phytotoxicity.
TABLE I__________________________________________________________________________Effectiveness and phytotoxicity of formulations containing PYRAZON with97% of PCA and PYRAZON with 84% ofPCA used in accordance with various techniques for eradicating weeds fromsugar beet. Treatments carried outFormulations Rates PRE-SOWING PRE-EMERGENCE POST-EMERGENCEemployed Kg/Ha B C S B C S B C S__________________________________________________________________________(1) WETTABLE POWDERS(a) with PYRAZON con- 4.000 Pyrazon 65% 0 91 100 0 97 100 0 83 100 taining 97% PCA = 2.600 PCA(b) with PYRAZON con- 3.350 Pyrazon 77.6% 0 86 100 0 90 100 0 72 100 taining 84% PCA = 2.600 PCA(2) WATER-DISPERSIBLE PASTES(a) with PYRAZON con- 5.000 Pyrazon Paste 0 95 100 0 99 100 0 85 100 taining 97% PCA = 2.580 PCA(b) with PYRAZON con- 6.000 Pyrazon Paste 0 90 100 0 94 100 0 77 100 taining 84% PCA = 2.580 PCACONTROL FIELD WITHOUTHERBICIDAL TREATMENTS 0 0 0 0 0 0 0 0 0__________________________________________________________________________ B = MARIBO UNICA SUGAR BEET VARIETY C = CHENOPODIUM ALBUM S = STELLARIA MEDIA
Example of Application II
Monogerm beets of the Monyx and Monogem varieties are sown in two fields and, after these crops or cultures have reached the stage of two true leaves, herbicidal treatments are carried out either with Pyrazon containing 84% of PCA or with Pyrazon containing 97% of PCA, at the rates indicated in the following Table II, the weed-killers being distributed uniformly over the entire surface of the fields with a conventional spraying pump for agricultural weed eradication equipped with a nozzle bar with a distributor.
30 days after the herbicidal treatment results may be observed. From the data obtained, given in Table II, it can be observed how the formulations containing Pyrazon with 97% of PCA present an unexpected lesser phytotoxicity for the beets and an as unexpected greater effectiveness on the infesting weeds compared with similar formulations containing Pyrazon with 84% of PCA and employed in equivalent amounts of active substance.
In the following Table II, the numbers relating to the effectiveness and phytotoxicity have the following significance:
0=no phytotoxicity on the crops or effectiveness on the weeds
100=total destruction of the crops or the weeds.
Intermediate values represent intermediate levels of phytotoxicity and effectiveness.
TABLE II__________________________________________________________________________Effectiveness and phytotoxicity of formulations containing PYRAZON with97% of PCA and PYRAZON with84% of PCA used in post-emergence in the eradication of weeds from sugarbeet. Type of weed Rates Type of beet Amaranthus ChenopodiumFormulations employed Kg/Ha Monyx Monogem Retroflexus Album__________________________________________________________________________(1) WETTABLE POWDERS(a) with Pyrazon con- 1.625 Pyrazon 80% 0 5 5 100 taining 97% = 1.300 PCA 2.438 Pyrazon 80% 5 15 100 100 = 1.950 PCA(b) with Pyrazon con- 2.000 Pyrazon 65% 5 10 0 70 taining 84% = 1.300 PCA 3.000 Pyrazon 65% = 1.950 PCA 20 20 40 100(2) WATER-DISPERSIBLE PASTES(a) with Pyrazon con- 2.600 Pyrazon paste taining 97% = 1.300 PCA 0 0 50 100 3.900 Pyrazon paste = 1.950 PCA 10 10 100 100(b) with Pyrazon con- 3.000 Pyrazon paste taining 84% = 1.300 PCA 25 20 20 30 4.350 Pyrazon paste = 1.950 PCA 30 30 45 55Control beets withouttreatments 0 0 0 0__________________________________________________________________________
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The compound 5-amino-4-chloro-2-phenyl-3(2H)-pyridazinone free from 5-chloro-4-amino-2-phenyl-3(2H)-pyridazinone is used as selective weed-killer in a remarkably more efficacious and remarkably less phytotoxical way than the presently known "pyrazon" (mixture of 5-amino-4-chloro-2-phenyl-3(2H)-pyridazinone and 5-chloro-4-amino-2-phenyl-3(2H)-pyridazinone). The 5-amino-4-chloro-2-phenyl-3(2H)-pyridazinone is obtained from pyrazon by treating said pyrazon with a mineral acid of pre-fixed concentration, obtaining a suspension and filtering such a suspension. The use thereof as weed-killer is carried out in suitable formulations.
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FIELD OF THE INVENTION
This invention relates generally to semiconductor memories, and more particularly to a high-speed sensing system for low voltage memories.
BACKGROUND OF THE INVENTION
Various types of memory devices, such as random access memory (RAM), read-only memory (ROM) and non-volatile memory (NVM), are known in the art. A memory device includes an array of memory cells and peripheral supporting systems for managing, programming and data retrieval operations.
Each of the memory cells in a memory device can be configured to provide an electrical output signal during a read operation. A sense amplifier is coupled to receive the electrical output signal, and in response, provide a data output signal representative of the logic state of the data stored by the memory cell.
In general, sense amplifiers determine the logical value stored in a memory cell by comparing the electrical output signal (i.e., voltage or current) provided by the cell with a threshold value (i.e., voltage or current). If the electrical output signal exceeds the threshold value, the sense amplifier provides a data output signal having a first logic value (e.g., logic “1”), thereby indicating that the memory cell is in a first logic state (e.g., an erased state). Conversely, if the electrical output signal is less than the threshold value, the sense amplifier provides a data output signal having a second logic value (e.g., logic “0”), thereby indicating that the memory cell is in a second logic state (e.g., a programmed state).
The threshold value is typically set at a level that is between the expected electrical output signal for a programmed state of a memory cell and the expected electrical output signal for an erased state of a memory cell. It is desirable to set the threshold value at a level that is sufficiently far from both expected levels, so that noise on the electrical output signal will not cause false results.
FIG. 1 is a block diagram of a conventional memory device 100 , which includes memory array 110 , reference memory array 112 , clamping circuits 120 - 121 , sense amplifier first stages 130 - 131 , and sense amplifier second stage 140 . Memory array 110 and reference memory array 112 each include a plurality of non-volatile memory cells arranged in rows and columns. For example, memory array 100 includes non-volatile memory cell 111 , and reference memory array 112 includes non-volatile memory cell 113 . Clamping circuit 120 includes PMOS transistors P 1 -P 2 , NMOS transistor N 1 and comparator C 1 , which are connected as illustrated. Similarly, clamping circuit 121 includes PMOS transistors P 7 -P 8 , NMOS transistor N 2 , and comparator C 2 , which are connected as illustrated. Clamping circuits 120 and 121 cause the charging operation to be performed in a staged manner to improve the efficiency of the sensing operation. Sense amplifier first stage 130 includes PMOS transistor P 3 and NMOS transistor N 4 . Sense amplifier first stage 131 includes PMOS transistor P 6 and NMOS transistor N 3 . Sense amplifier second stage 140 includes PMOS transistors P 4 -P 5 , and current comparator circuit 141 .
To read (or “sense”) the state of a memory cell in memory array 110 , the word line and bit lines associated with the memory cell are selected. For example, to read memory cell 111 , a read voltage is applied to word line W 1 by a row decoder, while bit line B N is coupled to a system bit line BL by a column decoder, and bit line B N+1 is grounded. A corresponding reference memory cell 113 in reference array 112 is configured in a similar manner. Thus, a read voltage is applied to word line W 1 by a row decoder, while bit line B M is coupled to a reference bit line BL_REF by a column decoder, and bit line B M+1 is grounded. System bit line BL and reference bit line BL_REF exhibit capacitances C BL and C REF — BL , respectively.
Sense amplifier first stage 130 and clamping circuit 120 apply a sense voltage on system bit line BL, thereby causing a read current I BL to flow through memory cell 111 . The magnitude of the read current I BL is determined by the logic state of memory cell 111 (i.e., programmed or erased). This read current I BL is mirrored to PMOS transistor P 4 of sense amplifier second stage 140 .
Similarly, sense amplifier first stage 131 and clamping circuit 121 apply the sense voltage on reference bit line BL_REF, thereby causing a read current I BL — REF to flow through reference memory cell 113 . The magnitude of the read current I BL — REF is determined by the logic state of reference memory cell 113 . Reference memory cell 113 is programmed such that the magnitude of the read current I BL — REF is less than the magnitude of the read current I BL when memory cell 111 is programmed, and greater than the magnitude of the read current I BL when memory cell 111 is erased. The read current I BL — REF is mirrored to PMOS transistor P 5 of sense amplifier second stage 140 .
After the read currents I BL and I BL — REF have had time to develop, the enable signal EN is activated, thereby causing comparator circuit 141 to detect the difference between these read currents. In response, comparator circuit 141 provides an output data signal D OUT , representative of the data stored in memory cell 111 .
Memory device 100 is described in more detail in commonly owned, co-pending U.S. patent application Ser. No. 09/935,013, “Structure and Method for High Speed Sensing of Memory Arrays”, by Alexander Kushnarenko and Oleg Dadashev [TSL-103].
Memory device 100 will not operate properly unless the V DD supply voltage is greater than a minimum voltage V DD — MIN , which is defined as follows.
V DD — MIN =V DIODE — MAX +V BL — MIN +V P1/P8 +V P2/P7 (1)
In Equation (1), V DIODE — MAX is the maximum voltage drop across PMOS transistor P 3 or PMOS transistor P 6 , V BL — MIN is the minimum acceptable bit line voltage for the non-volatile memory technology, V P1/P8 is the drain-to-source voltage drop of PMOS transistor P 1 (or PMOS transistor P 8 ), and V P2/P7 is equal to the drain-to-source voltage drop on PMOS transistor P 2 (or PMOS transistor P 7 ).
For example, if V DIODE — MAX is equal to 1.0 Volt, V BL — MIN is equal to 1.8 Volts, and V P1/P8 and V P2/P7 are equal to 0.05 Volts, then the minimum supply voltage V DD — MIN is equal to 2.9 Volts (1.8V+1V+0.05V+0.05V). In such a case, memory device 100 would not be usable in applications that use a V DD supply voltage lower than 2.9 Volts.
In addition, sense amplifier first stages 130 and 131 are sensitive to noise in the V DD supply voltage. If, during a read operation, the V DD supply voltage rises to an increased voltage of V DD — OVERSHOOT , then the voltages V SA1 and V SA2 on the drains of PMOS transistors P 3 and P 6 rise to a level approximately equal to V DD — OVERSHOOT minus a diode voltage drop. If the V DD supply voltage then falls to a reduced voltage of V DD — UNDERSHOOT , then transistors P 3 and P 6 may be turned off. At this time, sense amplifier first stages 130 and 131 cannot operate until the voltages V SA1 and V SA2 are discharged by the cell currents I BL and I BL — REF . If the cell current I BL is low, then sense amplifier first stage 130 will remain turned off until the end of the read operation, thereby causing the read operation to fail.
Accordingly, it is desirable to provide a sensing system that can accommodate low supply voltages and tolerate supply voltage fluctuations.
SUMMARY OF THE INVENTION
The present invention provides a system and method for sensing the state of a memory cell by integrating current differences between a read current produced by the memory cell and a reference current produced by a reference memory cell. The integration process generates differential measurement voltages that can be compared to determine the state of the memory cell relative to the state of the reference memory cell. By performing a sensing operation in this manner, low supply voltages can be accommodated and sensitivity to supply voltage noise can be minimized.
According to an embodiment of the invention, a sensing system for sensing the state of a memory cell includes a sense amplifier first stage for detecting the read current of the memory cell and the reference current of the reference memory cell. The sense amplifier first stage generates differential voltages by integrating over time two measurement currents—the first measurement current being a function of the reference current minus the read current, and the second measurement current being a function of the read current minus the reference current. The resulting differential voltages can then be compared to determine the state of the memory cell relative to the reference memory cell. Because the differential voltages are the result of cumulative current measurements over time, rather than a read current or voltage value at a particular moment in time, sensing operations performed using the sense amplifier first stage can be much less sensitive to supply voltage levels and/or fluctuations than sensing operations using conventional sensing systems.
According to an embodiment of the invention, the sense amplifier first stage includes a first current source and a second current source producing equal constant currents. A portion of the constant current from the first current source provides the read current for the memory cell, while a portion of the constant current from the second current source provides the reference current for the reference memory cell. Half of the remainder of the constant current from the first current source is subtracted from half of the remainder of the constant current from the second current source to define a first measurement current. Since the constant currents from the first and second current sources are equal, this first measurement current is half of the difference between the reference current and the read current (i.e., the reference current minus the read current). Concurrently, half of the remainder of the constant current from the first current source is subtracted from half of the remainder of the constant current from the second current source to define a second measurement current. Once again, since the constant currents from the first and second current sources are equal, the second measurement current is half of the difference between the read current and the reference current (i.e., the read current minus the reference current).
The first measurement current can then be integrated to produce a first measurement voltage, and the second measurement current can be integrated to produce a second measurement voltage. Because the first and second measurement voltages are based upon the positive and negative differences between the read current and the reference current, the two measurement voltages will be substantially similar if the states of the memory cell and the reference memory cell (as indicated by the read current and the reference current) are the same, while the measurement voltages will diverge if the two states are different. Note that this divergence will increase as the period of integration for the measurement voltages increases. Once the measurement voltages have been generated, a comparator can be used to compare the two and determine the state of the memory cell relative to the reference memory cell. According to an embodiment of the invention, a fast comparator can be used to improve the speed of the sensing operation.
The present invention will be more fully understood in view of the following description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram of a conventional memory device.
FIG. 2 is a circuit diagram of a memory system in accordance with one embodiment of the present invention.
FIG. 3 is a block diagram of a sense amplifier first stage, in accordance with one embodiment of the present invention.
FIG. 4 is a circuit diagram of the sense amplifier first stage of FIG. 3 in accordance with one embodiment of the present invention.
FIG. 5A is a circuit diagram of the sense amplifier first stage of FIG. 3 in accordance with another embodiment of the present invention.
FIG. 5B is a circuit diagram of the sense amplifier first stage of FIG. 3 in accordance with yet another embodiment of the present invention.
FIG. 6 is a circuit diagram of a sense amplifier second stage in accordance with one embodiment of the present invention.
FIG. 7 is a waveform diagram illustrating various signals associated with the operation of the sense amplifier first and second stages during a read operation.
DETAILED DESCRIPTION
FIG. 2 is a circuit diagram of a memory system 200 in accordance with one embodiment of the present invention. Because certain elements of memory system 200 are similar to certain elements of memory system 100 (FIG. 1 ), similar elements in FIGS. 1 and 2 are labeled with similar reference numbers. Thus, memory system 200 includes, memory array 110 , non-volatile memory cell 111 , reference memory array 112 , reference memory cell 113 , clamping circuits 120 - 121 , and bit lines BL and BL_REF (which exhibit bit line capacitances C BL and C BL — REF ).
Although memory array 110 and reference memory array 112 are illustrated as arrays having two rows and six columns, it is understood that memory array 110 and reference memory array 112 can have other dimensions in other embodiments. It is also understood that row and column decoding circuitry is not illustrated in memory array 110 or reference memory array 112 for purposes of clarity. According to another embodiment of the invention, the reference memory array 112 can be replaced with a single non-volatile memory cell, (e.g., non-volatile memory cell 113 ), which provides a known reference logic state for use in sensing operations for all the memory cells in memory array 110 . In this embodiment, the silicon area required for memory system 200 can be significantly reduced.
Memory system 200 additionally includes sense amplifier first stage 201 and sense amplifier second stage 202 . Sense amplifier first stage 201 is coupled to bit lines BL and BL_REF. As described in more detail below, sense amplifier first stage 201 provides the read current I CELL and the reference read current I REF — CELL to bit lines BL and BL_REF, respectively. Sense amplifier first stage 201 is also coupled to receive an active-low sense initialization signal SEN#.
Sense amplifier first stage 201 provides differential output voltages V OUT1 and V OUT2 to sense amplifier second stage 202 . Second amplifier stage 202 is also coupled to receive an active-high enable signal, LAT. As described in more detail below, sense amplifier second stage 202 provides an output data value SA OUT in response to the output voltages V OUT1 and V OUT2 when the enable signal LAT is activated high.
Returning to FIG. 2, memory cell 111 is selected for a read operation by applying a word line read voltage (e.g., 3-5 Volts) to word line W 1 of array 110 , coupling bit line B N to system bit line BL through a column decoder (not shown), and coupling bit line B N+1 to a ground supply voltage. At the same time, reference memory cell 113 is also selected by applying the word line read voltage to word line W 1 of array 112 , coupling bit line B M to reference bit line BL_REF through a column decoder (not shown), and coupling bit line B M+1 to a ground supply voltage.
Unlike conventional sense amplifiers, sense amplifier first stage 201 does not compare a read voltage or read current (i.e., I CELL ) introduced by the selected memory cell 111 directly against a reference voltage or current. Instead, sense amplifier first stage 201 performs a current integration operation based on positive and negative differentials between the read current I CELL and the reference current I REF . This integration operation (described in more detail below) results in the generation of differential output voltages V OUT1 and V OUT2 . The longer the integration period, the larger the difference between differential output voltages V OUT1 and V OUT2 . After a desired integration period, the enable signal LAT is activated, thereby instructing sense amplifier second stage 202 to sample the differential output voltages V OUT1 and V OUT2 , and in response, generate a sense amplifier output SA OUT (which indicates the state of the memory cell being sensed).
FIG. 3 is a block diagram of sense amplifier first stage 201 , in accordance with one embodiment of the present invention. Sense amplifier first stage 201 includes constant current sources 301 - 302 , current divider circuits 303 - 304 , current subtraction circuits 305 - 306 , output nodes 307 - 308 and initialization circuit 310 . Initialization circuit 310 is configured to receive the SEN# signal. At the beginning of a sensing operation, the SEN# signal is activated low, thereby causing initialization circuit to equalize (reset) the charge on current subtraction circuits 305 - 306 and output nodes 307 - 308 .
During a sensing operation, constant current sources 301 and 302 each provide a constant current I 0 . This constant current I 0 is greater than the expected read current I CELL (and the reference read current I REF ). A portion of the constant current I 0 provided by current source 301 flows to the memory cell being sensed (e.g., memory cell 111 ) as the read current I CELL . The remaining portion of constant current I 0 provided by current source 301 (i.e., I 0 −I CELL ) flows to current divider circuit 303 .
Similarly, a portion of the constant current I 0 provided by current source 302 flows to the reference memory cell (e.g., reference memory cell 113 ) as the reference read current I REF . The remaining portion of constant current I 0 provided by current source 301 (i.e., I 0 −I REF ) flows to current divider circuit 303 .
Current dividers 303 and 304 each divide the received currents in half. Thus, current divider 303 divides the received current of I 0 −I CELL into two equal currents of (I 0 −I CELL )/2. Similarly, current divider 304 divides the received current of I 0 −I REF into two equal currents of (I 0 −I REF )/2.
Current subtraction circuit 305 is configured to subtract the current (I 0 −I REF )/2 provided by current divider 304 from the current (I 0 −I CELL )/2 provided by current divider 303 , thereby providing an output current equal to (I REF −I CELL )/2. Similarly, current subtraction circuit 306 is configured to subtract the current (I 0 −I CELL )/2 provided by current divider 303 from the current (I 0 −I REF )/2 provided by current divider 304 , thereby providing an output current equal to (I CELL −I REF )/2.
Output node 307 is configured to receive the output current (I REF −I CELL )/2 provided by current subtraction circuit 305 . Output node 307 , which is coupled to the gate of a transistor in sense amplifier second stage 202 , exhibits a capacitance C OUT1 . As a result, the output voltage V OUT1 is developed on output node 307 . This output voltage V OUT1 can be defined as follows, where V 0 is equal to the initial voltage on output node 307 before the sensing operation is started.
V OUT1 ( t )=(∫ I OUT1 ( t ) dt )/ C OUT1 =V 0 +I OUT1 *t/C OUT1 (2)
Similarly, output node 308 is configured to receive the output current (I CELL −I REF )/2 provided by current subtraction circuit 306 . Output node 308 , which is coupled to the gate of a transistor in sense amplifier second stage 202 , exhibits a capacitance C OUT2 . As a result, the output voltage V OUT2 is developed on output node 308 . This output voltage V OUT2 can be defined as follows, where V 0 is equal to the initial voltage on output node 308 before the sensing operation is started.
V OUT2 ( t )=(∫ I OUT2 ( t ) dt )/ C OUT2 =V 0 +I OUT2 *t/C OUT2 (3)
The difference between the output voltages V OUT1 and V OUT2 can be defined as follows.
V OUT1 ( t )− V OUT2 ( t )=( V 0 +I OUT1 *t/C OUT1 )−( V 0 +I OUT2 *t/C OUT2 ) (4)
In the described embodiment, sense amplifier first stage 201 and sense amplifier second stage 202 are designed such that C OUT2 is equal to C OUT1 . Capacitances C OUT1 and C OUT2 can therefore be represented by the equivalent capacitance value C OUT . As a result, equation (4) can be simplified as follows.
V OUT1 ( t )− V OUT2 ( t )=( I REF −I CELL )* t /2 C OUT −( I CELL −I REF )* t /2 C OUT (5)
V OUT1 ( t )− V OUT2 ( t )=(( I REF −I CELL )* t −( I CELL −I REF )* t )/2 C OUT (6)
V OUT1 ( t )− V OUT 2 ( t )=(2 I REF *t −2 I CELL *t )/2 C OUT (7)
V OUT1 ( t )− V OUT2 ( t )=( I REF −I CELL )* t/C OUT (8)
The differential output signal represented by output voltages V OUT1 (t) and V OUT2 (t) is therefore a function of the differential input signal to sense amplifier first stage 201 , I REF −I CELL . The differential output signal represented by output voltages V OUT1 (t) and V OUT2 (t) therefore includes required information about the compared input signals. Sense amplifier first stage 201 integrates the differential input current (I REF −I CELL ), such that the differential output signal represented by output voltages V OUT1 (t) and V OUT2 (t) increases linearly with time. As a result, sense amplifier first stage 201 exhibits a relatively high sensitivity to differences between the input currents (I REF and I CELL ), while exhibiting a relatively low sensitivity to noise in the V DD supply voltage.
As described in more detail below, sense amplifier second stage 202 compares the differential output voltages V OUT1 and V OUT2 , and provides a data output signal SA OUT which has a first state if V OUT1 is greater than V OUT2 , and a second logic state if V OUT1 is less than V OUT2 .
FIG. 4 is a circuit diagram of sense amplifier first stage 201 in accordance with one embodiment of the present invention. Sense amplifier first stage 201 includes PMOS transistors 401 - 406 and NMOS transistors 411 - 417 . PMOS transistors 401 and 402 form constant current sources 301 and 302 , respectively. The source and bulk regions of PMOS transistors 401 and 402 are coupled to the V DD voltage supply terminal. The gates of PMOS transistors 401 and 402 are coupled to receive a first bias voltage V BIAS1 . The first bias voltage V BIAS1 is selected such that the constant current I 0 flows through each of PMOS transistors 401 and 402 . The drain of PMOS transistor 401 is coupled to the memory cell being read and current divider circuit 303 . As described above, current divider circuit 303 receives a current equal to (I 0 −I CELL ). The drain of PMOS transistor 402 is coupled to the reference memory cell and current divider circuit 304 . As described above, current divider circuit 304 receives a current equal to (I 0 −I REF ).
PMOS transistors 403 - 404 are identical transistors configured to form current divider circuit 303 . The source and bulk regions of PMOS transistors 403 and 404 are coupled to receive the current, (I 0 −I CELL ). The gates of PMOS transistors 403 and 404 are coupled to receive a second bias voltage V BIAS2 . As a result, half of the current (I 0 −I CELL ) flows through each of PMOS transistors 403 and 404 (i.e., (I 0 −I CELL )/2 flows through each of PMOS transistors 403 and 404 ). The drains of PMOS transistors 403 and 404 are coupled to the drains of NMOS transistors 411 and 412 , respectively.
Similarly, PMOS transistors 405 - 406 are identical transistors configured to form current divider circuit 304 . The source and bulk regions of PMOS transistors 405 and 406 are coupled to receive the current, (I 0 −I REF ). The gates of PMOS transistors 405 and 406 are coupled to receive a third bias voltage V BIAS3 . As a result, half of the current (I 0 −I REF ) flows through each of PMOS transistors 405 and 406 (i.e., (I 0 −I REF )/2 flows through each of PMOS transistors 405 and 406 ). The drains of PMOS transistors 405 and 406 are coupled to the drains of NMOS transistors 413 and 414 , respectively.
NMOS transistors 411 and 413 are configured to form current subtraction circuit 305 . The sources of NMOS transistors 411 and 413 are coupled to the ground supply terminal. The gates of NMOS transistors 411 and 413 are commonly connected to the drain of NMOS transistor 413 , thereby forming a current mirror circuit, whereby the current through NMOS transistor 413 is mirrored to NMOS transistor 411 . Thus, the current of (I 0 −I REF )/2 flowing through NMOS transistor 413 is mirrored to NMOS transistor 411 . As a result, the current flowing to output terminal 307 is necessarily equal to ((I 0 −I CELL )/2−(I 0 −I REF )/2), or (I CELL −I REF )/2. This current charges output terminal 307 to the output voltage V OUT1 as described above.
Similarly, NMOS transistors 412 and 414 are configured to form current subtraction circuit 306 . The sources of NMOS transistors 412 and 414 are coupled to the ground supply terminal. The gates of NMOS transistors 412 and 414 are commonly connected to the drain of NMOS transistor 412 , thereby forming a current mirror circuit, whereby the current through NMOS transistor 412 is mirrored to NMOS transistor 414 . Thus, the current of (I 0 −I CELL )/2 flowing through NMOS transistor 412 is mirrored to NMOS transistor 414 . As a result, the current flowing to output terminal 308 is necessarily equal to ((I 0 −I REF )/2−(I 0 −I CELL )/2), or (I REF −I CELL )/2. This current charges output terminal 308 to the output voltage V OUT2 as described above.
NMOS transistors 415 - 417 are configured to form initialization circuit 310 . NMOS transistors 415 - 417 are connected in series between output terminals 307 and 308 . The source of transistor 416 is coupled to the gates of NMOS transistors 412 and 414 . The drain of NMOS transistor 416 is coupled to the gates of NMOS transistors 411 and 413 . The gates of NMOS transistors 412 are coupled to receive the SEN# signal. When the SEN# signal is de-activated high (V DD ), NMOS transistors 415 - 417 are turned on, thereby equalizing the voltages on output terminals 307 - 308 , the gates of transistors 411 - 414 and the drains of transistors 412 - 413 . When sensing begins, the SEN# signal is activated low (0 Volts), such that NMOS transistors 415 - 417 are turned off, and the differential output voltages V OUT1 and V OUT2 develop on output terminals 307 and 308 in the manner described above.
In accordance with one embodiment of the present invention, the second and third bias voltages V BIAS2 and V BIAS3 are the same voltage, which is provided by an external bias voltage supply.
In accordance with another embodiment of the present invention, the second bias voltage V BIAS2 is provided by the drain of PMOS transistor 405 , and the third bias voltage V BIAS3 is provided by the drain of PMOS transistor 404 . FIG. 5A is a circuit diagram illustrating this embodiment of the present invention.
In accordance with another embodiment of the present invention, the second bias voltage V BIAS2 is provided by the drain of PMOS transistor 404 , and the third bias voltage V BIAS3 is provided by the drain of PMOS transistor 405 . FIG. 5B is a circuit diagram illustrating this embodiment of the present invention. Advantageously, the embodiments illustrated by FIGS. 5A and 5B do not require an additional voltage supply.
FIG. 6 is a circuit diagram of sense amplifier second stage 202 in accordance with one embodiment of the present invention. Sense amplifier second stage 202 includes NMOS transistors 601 - 607 , PMOS transistors 611 - 615 , inverter 619 and NOR gates 621 - 622 .
NMOS transistors 601 and 602 form a differential input pair, with the gate of NMOS transistor 601 coupled to receive the output voltage V OUT1 from output terminal 307 of sense amplifier first stage 201 , and the gate of NMOS transistor 602 coupled to receive the output voltage V OUT2 from the output terminal 308 of sense amplifier first stage 201 . The gate terminals of NMOS transistors 601 and 602 contribute to the capacitances C OUT1 and C OUT2 of output terminals 307 and 308 , respectively. NMOS transistor 603 is coupled between the sources of NMOS transistors 601 - 602 and the ground supply terminal. A fourth bias voltage V BIAS4 is applied to the gate of NMOS transistor 603 , thereby providing a current source to the differential pair formed by NMOS transistors 601 - 602 . The voltages on the drains of NMOS transistors 601 and 602 are labeled as voltages V A and V B , respectively.
PMOS transistors 611 - 615 , NMOS transistors 604 - 607 and inverter 619 are configured to form a CMOS latch circuit 610 . More specifically, the drains of transistors 601 and 602 are connected to the drains of p-type transistors 612 and 611 , respectively. PMOS transistor 611 , PMOS transistor 614 and NMOS transistor 605 are connected in series between the VDD voltage supply terminal and the ground supply terminal. PMOS transistor 612 , PMOS transistor 615 and NMOS transistor 606 are also connected in series between the VDD voltage supply terminal and the ground supply terminal. PMOS transistors 611 and 612 are cross-coupled, such that the gate of transistor 611 is coupled to the drain of transistor 611 , and the gate of transistor 612 is coupled to the drain of transistor 611 . NMOS transistors 605 and 606 are also cross-coupled, such that the gate of transistor 605 is coupled to the drain of transistor 606 , and the gate of transistor 606 is coupled to the drain of transistor 605 .
PMOS transistor 613 is connected across the drains of PMOS transistors 611 and 612 , with the gate of PMOS transistor 613 being coupled to receive the enable signal LAT. The enable signal LAT is inverted by inverter 619 and then applied to the gates of PMOS transistors 614 - 615 and NMOS transistors 604 and 607 . NMOS transistor 604 is connected between the drain of NMOS transistor 605 and the ground supply terminal. Similarly, NMOS transistor 607 is coupled between the drain of NMOS transistor 606 and the ground supply terminal.
NOR gates 621 and 622 are configured to form a data latch 620 . More specifically, one input terminal of NOR gate 621 is coupled to the drain of NMOS transistor 605 , and the other input terminal of NOR gate 621 is coupled to the output terminal of NOR gate 622 . Similarly, one input terminal of NOR gate 622 is coupled to the drain of NMOS transistor 606 , and the other input terminal of NOR gate 622 is coupled to the output terminal of NOR gate 621 . The output terminal of NOR gate 621 provides the output signal SA OUT .
The CMOS latch circuit 610 is turned off (i.e., the LAT signal is de-activated low) when there is no sensing operation being performed. At this time, transistors 604 , 607 and 613 are turned on, and transistors 614 - 615 are turned off. Under these conditions, turned-on transistor 613 equalizes the voltages V A and V B on the drains of differential pair transistors 601 and 602 . In addition, turned-on transistors provide logic low voltages to the input terminals of NOR gates 621 - 622 . As a result, data latch 620 continues to provide the previously stored output value SA OUT . The voltages provided to the input terminals of NOR gates 621 and 622 are labeled as voltages V C and V D , respectively.
During a sensing operation, the LAT signal is activated high, thereby turning off transistors 604 , 607 and 613 , and turning on transistors 614 - 615 . Under these conditions, CMOS latch circuit 610 is enabled, and operates as follows. As described above, one of the output voltages V OUT1 , V OUT2 will be higher than the other. For example, the output voltage V OUT2 may be higher than the output voltage V OUT1 . In this case, transistor 602 will have a higher conductance than transistor 601 , such that voltage V B is less than voltage V A . In response, transistors 612 and 605 will turn on, and transistors 611 and 606 will turn off, thereby pulling down the voltage V C to a logic low value, and pulling up the voltage V D to a logic high value. As a result, NOR gate 622 provides a logic low value to NOR gate 621 , and NOR gate 621 provides a logic high output value SA OUT .
Conversely, if the output voltage V OUT1 is higher than the output voltage V OUT2 , transistor 601 will have a higher conductance than transistor 602 , such that voltage V A is less than voltage V B . In response, transistors 611 and 606 will turn on, and transistors 612 and 605 will turn off, thereby pulling down the voltage V D to a logic low value, and pulling up the voltage V C to a logic high value. As a result, NOR gate 621 provides a logic high output value SA OUT , and NOR gate 622 provides a logic low output value.
FIG. 7 is a waveform diagram illustrating the SEN#, LAT, V OUT1 /V OUT 2 and SA OUT signals during a sensing operation. Prior to time T 1 , the SEN# signal is de-activated high, such that equalization circuit 310 is enabled. Under these conditions, the differential output voltage signals V OUT1 and V OUT2 have the same voltage. Data output latch 620 stores the previously read data value SA OUT , which happens to be a logic “1” value in the present example.
At time T 1 , the SEN# signal is activated low, thereby disabling equalization circuit 310 in sense amplifier first stage 201 . At this time, the output currents (I CELL −I REF )/2 and (I REF −I CELL )/2 begin to charge output terminals 307 and 308 to output voltages V OUT1 and V OUT2 , respectively. These output terminals 307 and 308 charge linearly with respect to time.
At time T 2 , the enable signal LAT is activated high, thereby enabling sense amplifier second stage 202 . In the described example, the output voltage V OUT1 is greater than the output voltage V OUT2 . As a result, the output signal SA OUT transitions from a logic “1” value to a logic “0” value between time T 2 and time T 3 .
At time T 3 , the enable signal LAT is de-activated low, thereby disabling sense amplifier second stage 202 . At this time, the logic “0” output signal SAOUT is stored in data latch 620 .
At time T 4 , the SEN# signal is de-activated high, thereby enabling equalization circuit 310 , and causing the output voltage V OUT1 and V OUT2 on output terminals 307 and 308 to be equalized. At this time sense amplifier stages 201 - 202 are ready to begin the next sensing operation.
The various embodiments of the structures and methods of this invention that are described above are illustrative only of the principles of this invention and are not intended to limit the scope of the invention to the particular embodiments described. For example, although the present invention has been described with reference to a memory array including NVM cells, the present invention is equally applicable to other types of memory cell arrays. Also, while various specific implementations of the invention have been illustrated using p-type or n-type devices, implementations using alternative device types will be readily apparent. Thus, the invention is limited only by the following claims and their equivalents.
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A sensing system for a memory cell in a memory array includes a current integrator circuit configured to integrate a read current through the memory cell and a reference current through a reference memory cell. The integration process creates a set of differential measurement voltages that can be used to determine the state of the memory cell. By integrating the read current to obtain a measurement voltage, rather than directly comparing the read current to a reference current, the sensing system can use lower supply voltages than conventional sensing systems. In addition, because the measurement voltages are generated by integrating the read current over time, sensing operations are less sensitive to supply voltage fluctuations and the accuracy. Also, for memory cells that exhibit small read currents, the accuracy of sensing operations can be increased by increasing the period of integration.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method and apparatus for drilling gas relief holes through coal beds, and more particularly to a method and apparatus for maintaining a rotating drill bit along a trajectory parallel to the bedding planes of subterranean coal beds.
The use of rotary drilling to form long horizontal gas relief holes in coal beds is known in the art as a means for degasifying a coal bed in advance of mining. These gas relief holes are either vented or connected to a vacuum source to remove methane from the coal bed. The greatest problem encountered in drilling these gas relief holes is that of maintaining the bit trajectory parallel to the coal bed such that the resulting holes are actually through the coal bed rather than through an overlying or underlying formation.
2. Description of the Prior Art
The state of the art to which the present invention pertains is set forth in detail in a Bureau of Mines Report of Investigations published in 1975 numbered 8097 and entitled "Rotary Drilling Holes in Coalbeds for Degasification", by Cervick et al, available in the U.S. Department of the Interior Library. That report describes the use of rotary drill bits attached to drill rods and maintained in a desired trajectory by a combination of bit thrust, rotational speed and drill rod centralizer spacing. That report further notes that locating a centralizer or stabilizer near the drill bit will cause a slight upward trajectory to the bit with proper drill thrust and bit rotational speed, and further notes that a downward trajectory can be obtained by locating a centralizer several meters behind the bit. However, relocating a centralizer to facilitate a change in bit trajectory due to change in bed dip or to the bit straying out of the coal bed for any reason has previously involved removal of the entire drill string. Such a procedure is time consuming and unproductive. The use of two centralizers as suggested in the report also presents problems.
U.S. Pat. No. 3,131,778 describes a device for changing the direction of a hole being drilled, the device including a housing having a shaped slot with lateral offsets. A drill bit is connected to the housing by a pin movable in the slot. However, the apparatus described in that patent is designed for drilling generally vertical boreholes, and is not suitable for drilling generally horizontal gas relief holes in coal beds.
There has been a continuing need, prior to the present invention, for an improved method and apparatus for controlling the trajectory of horizontal gas relief holes in coal beds.
SUMMARY OF THE INVENTION
According to the present invention, the horizontal trajectory of a rotating drill bit in a coal bed is controlled by use of a stabilizer or centralizer selectively positioned on a drill rod behind a drill bit. The stabilizer may be moved relative to the drill bit without removing the stabilizer from the borehole, thereby saving time and expense when the trajectory of the advancing borehole must be changed to accommodate a change in bed dip of a coal bed being drilled or to prevent the bit from straying out of the coal bed due to bit deviation from any cause.
It is an object of the present invention to provide an improved method and apparatus for drilling generally horizontal gas relief holes in coal beds.
It is a further object to provide such a method and apparatus that will enable an operator to follow the contour of a coal bed when drilling a gas relief hole without the necessity of removing the drill string to effect equipment changes for changing the direction of drilling.
The accomplishment of the foregoing as well as other objects and advantages is obtained by the present invention, and will be apparent from consideration of the following detailed description thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view of a length of drill rod having a slot formed according to the invention.
FIG. 2 is an orthogonal projection of a stabilizer in accordance with the invention.
FIG. 3 is a view of a length of drill rod with a stabilizer positioned adjacent a drill bit.
FIG. 4 is a view of a length of drill rod with a stabilizer positioned remote from a drill bit.
FIG. 5 is a view illustrating the apparatus of the invention in use.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The following detailed description, in conjunction with the drawings, describes the most preferred version of the apparatus and method of the invention.
It is often desirable in degasifying a coal bed to drill a series of gas relief holes for distances of 300 meters and more into the coal bed. Maintaining the bit on a horizontal trajectory parallel to the bedding planes of the coal bed is difficult. The natural tendency of the bit during horizontal drilling is to arc downward due to the forces of gravity. Other factors such as inclusions in the coal bed may also cause the bit to tend to deviate from the plane of the coal bed. It is generally desirable to maintain the bit trajectory within one degree of the plane of the coal bed being drilled through.
Prior to this invention, there were several approaches taken to maintain the bit trajectory along the desired path. The primary factors affecting the direction of drilling are bit thrust and bit rotational speed. As a general rule, decreased thrust and increased rotational speed tend to cause a downward effect on bit trajectory, while increased thrust and reduced rotational speed tend to cause an upward trajectory. It is also known that positioning a stabilizer or centralizer on the drill rod near the drill bit increases the tendency of the bit to move upwardly, while positioning a stabilizer several meters behind the drill bit tends to cause a downward trajectory of the bit. Other factors such as formation hardness, bit type and drill rod weight can affect the trajectory of the hole. An experienced operator must consider the above as well as other factors in controlling the trajectory of the hole. Using prior art procedures, it was sometimes necessary, upon encountering a downward dip in a coal bed, to remove the drill string from the hole and remove a stabilizer from adjacent the bit. This procedure is time-consuming and costly, and it would be desirable to be able to reposition the stabilizer on the drill rod without the necessity of removing the drill string from the hole, particularly after the hole has been drilled a substantial distance into the formation.
The apparatus according to the preferred embodiment of this invention will now be described in detail. Referring to FIG. 1, a length of drill rod 10 is shown having a slot 11 formed along the length thereof. Slot 11 inludes a lateral offset 12 at the forward end of slot 11 and a lateral offset 13 at the rearward end of slot 11. The slot 11 may be from three to ten meters long, but preferably is about five to seven meters long. Drill rod 10 includes a drill bit 14 attached at the forward end thereof.
Referring to FIG. 2, a stabilizer 15 including a cylindrical section 16 and helical vanes 17 attached to the outer surface thereof is shown. A key 18 protrudes from the inner wall of cylindrical section 16 to guide the stabilizer 15 along the length of drill rod 10 due to the action of key 18 and slot 11. Key 18 is also adapted to fit in the lateral offsets 12 and 13 upon being positioned adjacent thereto and upon clockwise rotation of drill rod 10. Key 18 can be released from lateral offsets 12 and 13 by counter-clockwise rotation of drill rod 10 allowing longitudinal movement of stabilizer 15 along the length of slot 11.
FIGS. 3 and 4 respectively illustrate the forward and rearward position of stabilizer 15 on drill rod 10. In the embodiment illustrated, the drill bit 14 is intended for clockwise rotation, such that the rotation of drill rod 10 and the forward thrust will both tend to secure key 18 in lateral offset 12 when the stabilizer 15 is in the position illustrated in FIG. 3. When it is desired to re-position stabilizer 15, drill rod 10 is pulled back slightly, rotated counter-clockwise a fraction of a turn, and then moved forward such that key 18 moves rearwardly relative to slot 11. Continued drilling will cause central stabilizer 15 to work back along the length of drill rod 10 until it reaches lateral offset 13, where it will then be secured in the rearward position. If it is desired to re-position stabilizer 15 from the forward to the rear position prior to any additional drilling, it is only necessary to withdraw the drill rod 10 a distance equal to or slightly greater than the length of slot 11, followed by slight counter-clockwise rotation of the drill string and forward movement of the drill rod 10.
It will be apparent to those skilled in the art that additional flexibility can be designed into the apparatus by providing additional lateral offsets along the length of slot 11 such that the stabilizer could be positioned at any desired distance from the drill bit by appropriate manipulation of the drill rod. Also, the apparatus could be used with only the forward offset 12, as the centralizer would tend to stay in the rearward position during drilling even without the rear lateral offset 13. However, the rear lateral offset 13 is helpful in maintaining the stabilizer in the rearward position under certain operating conditions.
The method in accordance with the invention will now be described, having reference to FIG. 5. In FIG. 5, a borehole 20 is shown extending into a coal bed 19 in a generally horizontal direction. The stabilizer 15 is positioned adjacent bit 14. The coal bed 19 forward of the drill bit 14 is shown dipping downwardly from the horizontal, such that the trajectory of the bit 14 must also dip downwardly to maintain the borehole 20 within the bed 19. To accomplish this, the operator would withdraw the drill rod 10 a distance at least equivalent to the length of slot 11, rotate drill rod 10 slightly counter-clockwise to release key 18 from forward offset 12 in slot 11, and then move drill rod 10 forwardly causing drill rod 10 to advance past stabilizer 15 until the key 18 contacts the rear of the slot 11. Upon resuming drilling, key 18 is secured in rear offset 13, and with the stabilizer 15 located several meters behind bit 14, the trajectory of the borehole 20 will tend to drop, enabling the borehole to be maintained within the coal bed 19 until the bed again resumes a horizontal or upward direction, at which time the stabilizer 15 can again be positioned adjacent the drill bit without the necessity of removing the entire drilling apparatus from the borehole.
The foregoing detailed description of the preferred embodiment of the invention is intended to be exemplary rather than limiting, and it will be appreciated that numerous variations and modifications could be made without departing from the true scope of the invention, which is to be defined by the appended claims.
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Apparatus and method for drilling generally horizontal holes through subterranean coal beds for release of methane gas from the coal beds are described. A sliding stabilizer on a drill rod is selectively positioned to provide elevational control to a rotating drill bit. The stabilizer is keyed to a slot in the drill rod, and lateral offsets in the slot are used to retain the stabilizer in the desired position on the drill rod.
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BACKGROUND OF INVENTION
[0001] 1. Field of the Invention
[0002] Embodiments disclosed herein generally relate to a downhole debris retrieval tool for removing debris from a wellbore. Further, embodiments disclosed herein relate to a downhole tool for debris removal with maximum efficiency at a low pump rates.
[0003] 2. Background Art
[0004] A wellbore may be drilled in the earth for various purposes, such as hydrocarbon extraction, geothermal energy, or water. After a wellbore is drilled, the well bore is typically lined with casing. The casing preserves the shape of the well bore as well as provides a sealed conduit for fluid to be transported to the surface.
[0005] In general, it is desirable to maintain a clean wellbore to prevent possible complications that may occur from debris in the well bore. For example, accumulation of debris can prevent free movement of tools through the wellbore during operations, as well as possibly interfere with production of hydrocarbons or damage tools. Potential debris includes cuttings produced from the drilling of the wellbore, metallic debris from the various tools and components used in operations, and corrosion of the casing. Smaller debris may be circulated out of the well bore using drilling fluid; however, larger debris is sometimes unable to be circulated out of the well. Also, the well bore geometry may affect the accumulation of debris. In particular, horizontal or otherwise significantly angled portions in a well bore can cause the well bore to be more prone to debris accumulation. Because of this recognized problem, many tools and methods are currently used for cleaning out well bores.
[0006] One type of tool known in the art for collecting debris is the junk catcher, sometimes referred to as a junk basket, junk boot, or boot basket, depending on the particular configuration for collecting debris and the particular debris to be collected. The different junk catchers known in the art rely on various mechanisms to capture debris from the well bore. A common link between most junk catchers is that they rely on the movement of fluid in the well bore to capture the sort of debris discussed above. The movement of the fluid may be accomplished by surface pumps or by movement of the string of pipe or tubing to which the junk catcher is connected. Hereinafter, the term “work string” will be used to collectively refer to the string of pipe or tubing and all tools that may be used along with the junk catchers. For describing fluid flow, “uphole” refers to a direction in the well bore that is towards the surface, while “downhole” refers to a direction in the well bore that is towards the distal end of the well bore.
[0007] The use of coiled tubing and its ability to circulate fluids is often used to address debris problems once they are recognized. Coiled tubing runs involving cleanout fluids and downhole tools to clean the production tubing are often costly.
[0008] Accordingly, there exists a need for a more efficient tool and method for removing debris from a wellbore.
SUMMARY OF INVENTION
[0009] In one aspect, embodiments disclosed herein relate to a downhole debris recovery tool including a ported sub coupled to a debris sub, a suction tube disposed in the debris sub, and an annular jet pump sub disposed in the ported sub and fluidly connected to the suction tube.
[0010] In another aspect, embodiments disclosed herein relate to a method of removing debris from a wellbore including the steps of lowering a downhole debris removal tool into the wellbore, the downhole debris removal tool having an annular jet pump sub, a mixing tube, a diffuser, and a suction tube, flowing a fluid through a bore of the annular jet pump sub, jetting the fluid from the annular jet pump sub into the mixing tube, displacing an initially static fluid in the mixing tube through the diffuser, thereby creating a vacuum effect in the suction tube to draw a debris-laden fluid into the downhole debris removal tool, and removing the tool downhole debris removal tool from the wellbore after a predetermined time interval.
[0011] In yet another aspect, embodiments disclosed herein relate to an isolation valve including a housing, an inner tube disposed coaxially within the housing, and a gate, wherein the gate is configured to selectively close an annular space between the housing and the inner tube.
[0012] Other aspects and advantages of the invention will be apparent from the following description and the appended claims.
BRIEF DESCRIPTION OF DRAWINGS
[0013] FIGS. 1A and 1B show plots of jet pump operations and equations.
[0014] FIGS. 2A and 2B show a side view and a cross sectional view, respectively, of a downhole debris removal tool in accordance with embodiments disclosed herein.
[0015] FIG. 3 shows the overall operation of a downhole debris removal tool in accordance with embodiments disclosed herein.
[0016] FIG. 4 shows a cross sectional view of a ported sub of downhole debris removal tool in accordance with embodiments disclosed herein.
[0017] FIG. 5 shows a cross sectional view of a debris sub section of downhole debris removal tool in accordance with embodiments disclosed herein.
[0018] FIG. 6 shows a cross sectional view of a bottom sub and a debris removal cap of a downhole debris removal tool in accordance with embodiments disclosed herein.
[0019] FIG. 7 is a perspective view of a screen of a downhole debris removal tool in accordance with embodiments disclosed herein.
[0020] FIG. 8 shows a cross sectional view of a bottom sub and a debris removal cap of downhole debris removal tool in accordance with embodiments disclosed herein, with the debris removal cap removed from its assembled position.
[0021] FIGS. 9-11 are graphs of suction flow rate versus the pump flow rate for 0.16 d/D, 0.25 d/D, and 0.39 d/D ratio rings, respectively, of a downhole debris removal tool in accordance with embodiments disclosed herein.
[0022] FIG. 12 is a schematic view of a test procedure for evaluating the amount of debris lifted by a downhole debris removal tool in accordance with embodiments disclosed herein.
[0023] FIGS. 13A and 13B show perspective and cross sectional views, respectively, of an annular jet pump sub in accordance with embodiments disclosed herein.
[0024] FIG. 14 shows an exploded view of an isolation valve in accordance with embodiments disclosed herein.
[0025] FIGS. 15A and 15B show open and closed configurations, respectively, of an isolation valve in accordance with embodiments disclosed herein.
[0026] FIG. 16 shows an exploded view of an isolation valve in accordance with embodiments disclosed herein.
[0027] FIGS. 17A and 17B show open and closed views, respectively, of an isolation valve in accordance with embodiments disclosed herein.
[0028] FIGS. 18A and 18B show open and closed cross sectional views, respectively, of an isolation valve in accordance with embodiments disclosed herein.
[0029] FIG. 19 shows a cross sectional view of a portion of a debris catcher tool in accordance with embodiments disclosed herein.
[0030] FIGS. 20A and 20B show open and closed cross sectional views, respectively, of a drain pin in accordance with embodiments disclosed herein.
[0031] FIG. 21A shows a cross sectional view of a debris catcher tool in accordance with embodiments disclosed herein; FIG. 21B shows a close-perspective view of portion 2100 of FIG. 21A .
[0032] FIG. 22 shows a detailed view of a portion of a debris catcher tool in accordance with embodiments disclosed herein.
DETAILED DESCRIPTION
[0033] Generally, embodiments of the present disclosure relate to a downhole tool for removing debris from a wellbore. More specifically, embodiments disclosed herein relate to a downhole debris removal tool that includes an annular jet pump. Further, certain embodiments disclosed herein relate to a downhole tool for debris removal with maximum efficiency at a low pump rates.
[0034] A downhole debris removal tool, in accordance with embodiments disclosed herein, includes a jet pump device. Generally, a jet pump is a fluid device used to move a volume of fluid. The volume of fluid is moved by means of a suction tube, a high pressure jet, a mixing tube, and a diffuser. The high pressure jet injects fluid into the mixing tube, displacing the fluid that was originally static in the mixing tube. This displacement of fluid due to the high pressure jet imparting momentum to the fluid causes suction at the end of the suction tube. The high pressure jet and the entrained fluid mix in the mixing tube and exit through the diffuser.
[0035] Basic principles of jet pump operation may generally be explained by Equation 1 below, with reference to FIGS. 1A and 1B .
[0000] Jet Pump Efficiency=( H D −H S /H J −H D )( Q S /Q J ) (1)
[0000] where H D is discharge head, H S is suction head, H J is jet head, Q S is suction volume flow, and Q J is driving volume flow. In accordance with certain embodiments of the present disclosure, for maximum jet pump efficiency, an inlet of the annular jet pump is smooth and convergent, while the diffuser is divergent. Additionally, the ratio of the inner diameter, d, of the jet to the inner diameter, D, of the mixing tube ranges from 0.14 to 0.9. Further, the jet standoff distance or driving nozzle distance, l, ranges from 0.8 to 2.0 inches. The mixing tube length, L m , is approximately 7 times the inner diameter of the mixing tube, D.
[0036] Embodiments of the present disclosure provide a downhole debris removal tool for removing debris from a completed wellbore with a low rig pump rate. An operator may circulate fluid conventionally down a drillstring at a low flow rate when desirable, e.g., in wellbores with open perforations or where a pressure sensitive formation isolation valve (FIV) is used. The downhole debris removal tool, in accordance with embodiments disclosed herein, lifts (through a vacuum effect) a column of fluid from the bottom of the tool at a velocity high enough to capture heavy debris, such as perforating debris or milling debris, with a low rig pump rate. In contrast, in conventional debris removal tools, high pump flow rates are required to remove such heavy debris. In certain embodiments, the downhole debris removal tool has sufficient capacity to store the collected debris in-situ, thereby providing easy removal and disposal of the debris when the tool is returned to the surface.
[0037] Referring now to FIGS. 2A and 2B , a side view and a cross sectional view of a downhole debris removal tool 200 , in accordance with embodiments of the present disclosure, are shown, respectively. The downhole debris removal tool 200 includes a top sub 201 , a ported sub 203 , a debris sub 202 , a bottom sub 205 , and a debris removal cap 207 . The top sub 201 is configured to connect to a drill string and includes a central bore 243 configured to provide a flow of fluid through the downhole debris removal tool 200 . In certain embodiments, the debris sub 202 may be made up of more than one tubing section coupled together. For example, an extension piece, or additional tubing, may be added to the debris sub 202 to provide additional collection and storage space for debris. A section of washpipe (not shown) may be provided below the downhole debris removal tool 200 .
[0038] The ported sub 203 is disposed below the top sub 201 and houses a mixing tube 208 , a diffuser 210 , and an annular jet pump sub 206 . The ported sub 203 is a generally cylindrical component and includes a plurality of ports configured to align with the diffuser 210 proximate the upper end of the ported sub 203 , thereby allowing fluids to exit the downhole debris removal tool 200 . The ported sub 203 may be connected to the top sub 201 by any mechanism known in the art, for example, threaded connection, welding, etc.
[0039] As shown in more detail in FIG. 4 , the annular jet pump sub 206 is a component disposed within the ported sub 203 . The annular jet pump sub 206 includes a bore 228 in fluid connection with the central bore of the top sub 201 . At least one small opening or jet 209 fluidly connects the bore 228 of the annular jet pump sub 206 to the mixing tube 208 . The jets 209 provide a flow of fluid from the drill string into the mixing tube 208 to displace initially static fluid in the mixing tube 208 . The fluid then flows upward in the mixing tube 208 and exits the ported sub 203 through the diffuser 210 , as indicated by the solid black lines.
[0040] Referring to FIGS. 2 , 4 , and 5 , a lower end 230 of the annular jet pump sub 206 is disposed proximate an exit end of a screen 214 disposed in the debris sub 202 , forming an inlet 226 into the mixing tube 208 . Fluid suctioned up through the debris sub 202 enters the mixing tube 208 through the inlet 226 and exits the mixing tube 208 through one or more diffusers 210 . An annular jet cup 232 is disposed over the lower end 230 of the annular jet pump sub 206 and configured to at least partially cover jets 209 to provide a ring nozzle. The at least one jet 209 size may be changed by varying the gap between the annular jet cup 232 and the annular jet pump sub 206 , thereby providing for flexible operation of the downhole debris removal tool 200 . The gap may be varied by moving the annular jet cup 232 in an uphole or downhole direction along the annular jet pump sub 206 . In one embodiment, the annular jet cup 232 may be threadedly coupled to the annular jet pump sub 206 , thereby allowing the annular jet cup 232 to be threaded into a position that provides a desired gap between annular jet cup 232 and the annular jet pump sub 206 .
[0041] A spacer ring 224 may be disposed around the lower end 230 of the annular jet pump sub 206 and proximate a shoulder 234 formed on an outer surface of the lower end 230 . The spacer ring 224 is assembled to the annular jet pump sub 206 and the annular jet cup 232 is disposed over the lower end 230 and the spacer ring 224 . Thus, the spacer ring 224 limits the movement of the annular jet cup 232 . One or more spacer rings 224 with varying thickness may be used to selectively choose the location of the assembled annular jet cup 232 , and provide a pre-selected gap between the annular jet cup 232 and the annular jet pump sub 206 . That is, the thickness of the spacer ring 224 may be selected so as to provide a desired d/D ratio. Varying the gap between the annular jet cup 232 and the annular jet pump sub 206 also provides for adjustment of the distance of the at least one jet 209 from the mixing tube 208 entrance. Thus, the jet standoff distance (l) of the tool 200 may be increased, thereby promoting jet pump efficiency.
[0042] Referring back to FIGS. 2A and 2B , the debris sub 202 is coupled to a lower end of the ported sub 203 and houses a suction tube 204 , a flow diverter 212 , and the screen 214 . The debris sub 202 may be connected to the ported sub 203 by any mechanism known in the art, for example, threaded connection, welding, etc. The debris sub 202 is configured to separate and collect debris from a fluid stream as the fluid is vacuumed or suctioned up through the downhole debris recovery tool 200 . Referring also to FIG. 5 , the suction tube 204 is configured to receive a stream of fluid and debris from the wellbore and directs the stream through the flow diverter 212 . In one embodiment, the flow diverter 212 may be a spiral flow diverter. In this embodiment, the spiral flow diverter is configured to impart rotation to the fluid/debris stream as it enters a debris chamber from the suction tube 204 . The rotation imparted to the fluid helps separate the fluid stream from the debris. The debris separated from the fluid stream drops down and is contained within the debris sub 202 . A debris removal cap 207 is coupled to a lower end of the debris sub 202 and may be removed from the downhole debris recovery tool 200 at the surface to remove the collected debris from the downhole debris recovery 200 (see FIGS. 6 and 8 ). The downhole debris recovery tool 200 may be configured to collect a specified anticipated debris volume. The length of the debris sub 202 may be selected based on the anticipated debris volume in the wellbore.
[0043] In one embodiment, the screen 214 may be a cylindrical component with a small perforations disposed on an outside surface, as shown in FIG. 7 . In alternate embodiments, the outer cylindrical surface of the screening device 214 may be formed from a wire mesh cloth, as shown in FIG. 5 . One of ordinary skill in the art will appreciate that any screening device known in the art for debris recovery may be used without departing from the scope of embodiments disclosed herein. In certain embodiments, the screen 214 is a low differential pressure screen. A packing element 240 and an element seal ring 242 are disposed around a pin end of the screen 214 to prevent fluid from bypassing the screen 214 . The fluid stream flowing through the diverter 212 enters the screen 214 . Debris larger than the perforations or mesh size of the screen cloth remains on the surface of the screen or fall and remain within the debris sub 202 . The filtered stream of fluid is then further suctioned up into the ported sub 203 .
[0044] FIG. 3 shows a general overview of the operation of the downhole debris removal tool 200 . Solid arrow lines indicate driving flow, while dashed arrow lines indicate suction flow of the tool. As shown, fluid is pumped down through the central bore of the top sub 201 and into the bore 228 of the annular jet pump sub 206 . The fluid is pumped at a low flow rate. For example, in certain embodiments, the fluid flowed into the bore 228 of the annular jet pump sub 206 is pumped at a rate of less than 10 BPM. In some embodiments, the fluid flowed through the bore 228 of the annular jet pump sub 206 is pumped at a rate of approximately 7 BPM. The fluid exits the annular jet pump sub 206 through a high pressure jet 209 into the mixing tube 208 . Injection of the fluid into the mixing tube 208 displaces the originally static fluid in the mixing tube 208 , thereby causing suction at the suction tube 204 . The high pressure jet fluid and the entrained fluid mix in the mixing tube 208 and exit through the diffuser 210 . The fluid exiting the diffuser 210 and vacuum effect at the suction tube 204 dislodges and removes debris from the wellbore.
[0045] In certain embodiments, at least one extension piece may be added to the downhole debris removal tool to increase the capacity of the debris sub 202 such that more debris may be stored/collected therein. FIGS. 21A and 21B show one embodiment having an extension piece 2100 disposed between two sections of debris sub 202 . The at least one extension piece may have an inner tube 2104 configured to align with the suction tube 204 . Additionally, in select embodiments, the inner tube 2104 of the expansion piece 2100 may be coupled to a flow diverter 212 , and/or inner tubes 2104 of additional expansion pieces 2100 . The at least one extension piece 2100 may also have an outer housing 2102 configured to couple to at least one debris sub 202 , and/or outer housing 2102 of additional expansion pieces. One of ordinary skill in the art will appreciate that multiple extension pieces may be added to the downhole debris recovery tool, and that components may be coupled by any means known in the art. For example, components may be coupled using threads, welding, etc.
[0046] At least one isolation valve 2106 may be integrated into the at least one extension piece 2100 , as shown in FIG. 21 . Alternatively, one of ordinary skill in the art will appreciate that the extension piece 2100 and the isolation valve 2106 may be independent components, or in another embodiment, the isolation valve 2106 may be integrated into a debris sub 202 . In select embodiments, more than one isolation valve may be used such that multiple chambers may be created within the debris removal tool.
[0047] Referring to FIG. 14 , an isolation valve 1400 in accordance with embodiments disclosed herein is shown. The isolation valve 1400 includes a housing 1402 , upper and lower portions of an inner tube, referred to herein as velocity tube 1404 , an annular space 1426 disposed between the housing 1402 and the velocity tube 1404 , a gate 1406 , a cutout 1414 , and a central axis 1420 . The velocity tube 1404 and the housing 1402 may have inner and outer diameters substantially the same as the inner and outer diameters of suction tube 204 and debris sub 202 , respectively, of FIGS. 2A and 2B . The isolation valve 1400 may also include a cutout 1414 disposed through the velocity tube 1404 and the housing 1402 , which accommodates a gate 1406 . Gate 1406 may rotate a cutout axis 1416 . The cutout axis 1416 may be substantially perpendicular to the central axis 1420 of the isolation valve 1400 . The gate 1406 may further include an o-ring 1408 , a circlip 1410 , a hex socket head 1422 , a gate hole 1418 , and a gate hole axis 1424 . The gate hole 1418 may have a diameter substantially equal to the inner diameter of the upper and lower portions of velocity tube 1404 .
[0048] FIGS. 15A and 15B show open and closed configurations, respectively, of the isolation valve 1400 shown in FIG. 14 . As shown in FIG. 15A , the isolation valve 1400 is open when the gate hole axis 1424 is axially aligned with central axis 1420 , thus allowing flow through both the velocity tube 1404 and the annular space 1426 . FIG. 15B shows a closed isolation valve 1400 having the gate hole axis 1424 disposed perpendicular to the central axis 1420 . In the closed configuration, flow through the velocity tube 1404 and the annular space 1426 is restricted. In the embodiment shown in FIGS. 14 , 15 A, and 15 B, the hex socket head 1422 may be engaged with a corresponding tool (not shown) and rotated to change the position of the gate 1406 relative to the velocity tube 1404 and annular space 1426 . Other socket head geometries, such as square or star socket heads, may also be used. Furthermore, one of ordinary skill in the art will appreciate that other mechanical or hydraulic means for controlling the gate may be used without departing from the scope of the present disclosure. For example, a shearing pin may be used to control the actuation of isolation valve 1400 in accordance with embodiments disclosed herein.
[0049] FIGS. 16 , 17 A, and 17 B show another exemplary isolation valve 1600 in accordance with the embodiments disclosed herein. Isolation valve 1600 allows uninterrupted flow through velocity tube 1604 and selectively allows flow through annular space 1626 . Isolation valve 1600 includes a housing 1602 , a velocity tube 1604 , an annular space 1626 disposed between housing 1602 and velocity tube 1604 , a central axis 1620 , a gate 1606 , and rotatable brackets 1608 . The gate 1606 may further include a hole 1614 through which velocity tube 1604 is disposed, and at least one curved surface 1610 configured to allow movement of the gate 1606 relative to the velocity tube 1604 . Rotatable brackets 1608 may be configured to couple to the gate 1606 and to bracket holes 1616 disposed in the housing 1602 . Additionally, a hex socket head 1622 may be disposed on at least one of the rotatable brackets 1608 . Alternatively, other socket head geometries, such as square or star socket heads, may be used. The rotatable brackets 1608 , together with the gate 1606 , may be rotated about a gate axis 1624 relative to the velocity tube 1604 .
[0050] Referring to FIGS. 17A and 18A , an isolation valve 1600 is shown in an open position in accordance with embodiments disclosed herein. The gate 1606 may be positioned such that flow through the annular space 1626 is allowed ( FIG. 17A ). In certain embodiments, the at least one curved surface 1610 of the opened gate 1606 may contact an outer surface of the velocity tube 1604 . Referring to FIGS. 17B and 18B , the gate 1606 of isolation valve 1600 may be positioned such that flow through the annular space 1626 is restricted. In the embodiment shown in FIGS. 17A , 17 B, 18 A, and 18 B, flow through the velocity tube 1604 of isolation valve 1600 is allowed, regardless of the position of gate 1606 .
[0051] During operation, the at least one isolation valve remains open so that the suction action of the tool is maintained. It may be advantageous to close the at least one isolation valve when the downhole debris removal tool is pulled from the well so that an extension piece may be installed. While the isolation valve is in the closed position, components may be added, removed, and/or replaced therebelow without fluid and debris that may have accumulated above the isolation valve spilling out into the wellbore or onto the deck. Additionally, after the debris removal tool is removed from the well, components therebelow may be removed and the isolation valve may be opened so that accumulated debris may be removed from the tool.
[0052] Referring back to FIG. 3 , suction at the suction tube 204 provided by the annular jet pump sub 206 may draw fluid and debris into the downhole debris removal tool 200 , and through at least one isolation valve. After passing through the at least one isolation valve, the flow diverter 212 diverts the fluid/debris mix from the suction tube 204 downward, as shown in more detail in FIG. 5 . The flow diverter 212 is configured to provide rotation to the fluid stream as it is diverted downwards. The rotation provided to the fluid stream may help separate the debris from the fluid stream due to the centrifugal effect and the greater density of the debris. Thus, the flow diverter 212 separates larger pieces of debris from the fluid. The debris separated from the fluid streams drop downwards within the debris sub 202 . After the fluid stream exits the diverter, it travels through the screen 214 . The screen 214 is configured to remove additional debris entrained in the fluid stream.
[0053] As shown in FIG. 22 , in select embodiments, at least one magnet 2202 may be disposed on or near a lower end of the screen 214 . The magnets 2202 may magnetically attract metallic debris suspended in the fluid and may prevent the metallic debris from clogging the screen 214 . FIG. 22 shows an embodiment having magnets 2202 that are ring-shaped and disposed around an outer surface of shaft 2206 . The magnets may be rare earth magnets, such as samarium-cobalt or neodymium-iron-boron (NIB) magnets. One of ordinary skill in the art will appreciate that magnets of other shapes and sizes may also be used. Additionally, the embodiment of FIG. 22 shows a magnet cover 2204 disposed around the magnets 2202 such that the fluid may not directly contact the magnets 2202 . The cover 2204 may protect the magnets 2202 from being damaged by debris.
[0054] Referring back to FIG. 3 , after passing through the screen 214 , the fluid flows past the annular jet pump sub 206 into the mixing tube 208 . The fluid is then returned to the casing annulus (not shown) through the diffuser 210 . In embodiments disclosed herein, as shown in FIGS. 2-8 , the fluid entering the mixing tube 208 from the suction tube 204 does not significantly change direction until after the fluid enters the diffuser 210 and is diverted into the casing annulus. In contrast, in conventional debris removal tools with conventional nozzle arrangements, fluid flowing from the suction tube changes direction 180 degrees to enter the mixing tube.
[0055] After completion of the debris recovery job, the drill string is pulled from the wellbore and the downhole debris recovery tool 200 is returned to the surface. As shown in FIGS. 6 and 8 , a retaining screw 220 may be removed from the debris removal cap 207 to allow the debris removal cap 207 to be removed from the downhole debris recovery tool 200 , thereby allowing the debris to be easily removed (indicated by dashed arrows) from the debris sub 202 .
[0056] In certain embodiments, a drain pin may be disposed in bottom sub 205 and may be opened before removing debris removal cap 207 so that fluid may be emptied from the bottom sub 205 and/or the debris sub 202 . Referring to FIG. 19 , the drain pin 1902 may be opened to allow fluid from at least one cavity 1904 , disposed in bottom sub 205 , to flow out through suction tube 204 . In certain embodiments, a hex socket head 1906 may be disposed on the drain pin 1902 . One of ordinary skill in the art will appreciate that alternative socket geometries, such as square or star, may be used without departing from the scope of the present disclosure. The hex socket head 1906 may be engaged with a corresponding tool (not shown) and rotated to open or close the drain pin 1902 . FIGS. 20A and 20B show cross-sectional views of a debris removal tool having a drain pin 1902 . FIG. 20A shows drain pin 1902 in the open position, allowing fluid communication between at least one cavity 1904 and suction tube 204 . In certain embodiments, the space created by the opened drain pin 1902 may be sized to prevent debris from escaping with the fluid. FIG. 20B shows drain pin 1902 in the closed position preventing fluid in cavity 1904 from entering suction tube 204 . It may be advantageous to open drain pin 1902 prior to removing debris removal cap 207 so that fluid may be released from the tool before debris removal, thereby preventing the fluid from spilling out onto, for example, the rig floor.
[0057] Referring now to FIGS. 13A and 13B , an alternate embodiment of an annular jet pump sub 306 in accordance with embodiments of the present disclosure is shown. Annular jet pump sub 306 is disposed within a ported sub 303 which provides a mixing tube 308 , and includes a two staged annular jet pump 360 . As shown, the annular jet pump sub 306 includes two stages 313 , 315 . The annular jet pump sub 306 includes a bore 328 in fluid connection with the central bore of a top sub 301 . As shown, the first stage 313 includes at least one small opening or jet 309 disposed near a lower end of the annular jet pump sub 306 and the second stage 315 includes at least one small opening or jet 311 disposed axially above the first stage 313 . The jets 309 , 311 fluidly connect the bore 328 of the annular jet pump sub 306 to the mixing tube 308 .
[0058] The two stages 313 , 315 of the annular jet pump sub 306 may provide a more efficient pumping tool. In particular, the two staged annular jet pump 360 may reduce the pumping flow rate of the tool and double the overall efficiency of the downhole debris removal tool 300 . In the embodiment shown in FIGS. 13A and 13B , a flow of fluid exits the annular jet pump sub 306 through jets 309 of first stage 313 into mixing tube 308 . Injection of the fluid into the mixing tube 308 displaces the originally static fluid in the mixing tube 308 , thereby causing suction at a suction tube ( 204 in FIG. 3 ) disposed below the annular jet pump sub 306 . Additionally, a flow of fluid exits the annular jet pump sub 306 through jets 311 of second stage 315 into mixing tube 308 . The flow of fluid exiting the annular jet pump sub 306 through second stage 315 accelerates fluid flow in the mixing tube 308 . The fluid then flows upward in the mixing tube 308 and exits the ported sub through the diffuser 310 . The suction provided by the first stage 313 and the acceleration of fluid provided by the second stage 315 of the annular jet pump sub 306 may allow a small volume of fluid to pull a larger volume of fluid with a lower pressure than a one-stage annular jet pump.
[0059] Referring to FIGS. 5 and 13 together, a lower end 330 of the annular jet pump sub 306 is disposed proximate an exit end of a screen 214 disposed in the debris sub 202 , forming an inlet (not shown) into the mixing tube 308 . Fluid suctioned up through the debris sub 202 enters the mixing tube 308 through the inlet (inlet) and exits the mixing tube 308 through one or more diffusers 310 . An annular jet cup 323 may be disposed over the lower end 330 of the annular jet pump sub 306 and configured to at least partially cover jets 309 of the first stage 313 to provide a ring nozzle. A second annular jet cup 325 may be disposed around the annular jet pump sub 306 proximate the second stage 315 and configured to at least partially cover jets 311 to provide a ring nozzle. One of ordinary skill in the art will appreciate that based on the specific needs of a given application, the annular jet pump sub 306 may include an annular jet cup 323 for only the first stage 313 , an annular jet cup 325 for only the second stage 315 , or an annular jet cup 323 , 325 for both the first and second stages 313 , 315 . The size of the jets 309 , 311 may be changed by varying the gap between the annular jet cup 323 , 325 and the annular jet pump sub 306 , thereby providing for flexible operation of the downhole debris removal tool 300 . The gap may be varied by moving the annular jet cup 323 , 325 in an uphole or downhole direction along the annular jet pump sub 306 . In one embodiment, the annular jet cup 323 , 325 may be threadedly coupled to the annular jet pump sub 306 , thereby allowing the annular jet cup 323 , 325 to be threaded into a position that provides a desired gap between the annular jet cup 323 , 325 and the annular jet pump sub 306 .
[0060] As discussed above, a spacer ring (not shown) may be disposed around the lower end 330 of the annular jet pump sub 306 and proximate a shoulder (not shown) formed on an outer surface of the lower end 330 . The spacer ring (not shown) may limit the movement of the annular jet cup 323 , 325 . One or more spacer rings with varying thickness may be used to selectively choose the location of the assembled annular jet cup 323 , 325 , and provide a pre-selected gap between the annular jet cup 323 , 325 and the annular jet pump sub 306 . That is, the thickness of the spacer ring may be selected so as to provide a desired d/D ratio. Varying the gap between the annular jet cup 323 , 325 and the annular jet pump sub 306 also provides for adjustment of the distance of the at least one jet 309 , 311 from the mixing tube 308 entrance. Thus, the jet standoff distance (l) of the tool 300 may be increased, thereby promoting jet pump efficiency
[0061] Tests
[0062] Tests were run on various embodiments of the present disclosure. A summary of these tests and the results determined are described below.
[0063] A 7⅞″ downhole debris recovery tool, in accordance with embodiments disclosed herein, was tested to evaluate the suction flow (flow at the pin end of the tool) for a given driving flow (pump flow rate through the tool). The flow rates at each location were determined using flow meters. To evaluate the suction flow, fluid was pumped through the tool at 20-425 gpm for 2-3 minutes at each pump rate. Pump pressure, pump flow rate, and in-line flow meter rate were recorded. The tool was tested with various spacer rings to provide 0.16 d/D, 0.25 d/D, and 0.39 d/D ratio rings. The results of this part of the test are summarized below in Tables 1-3.
[0000]
TABLE 1
0.16 d/D Ratio Ring Test Results
Pump Rate
Standpipe
Flow Meter
(GPM)
pressure (PSI)
Rate (GPM)
30
50
11.5
45
100
17
65
175
24.5
90
350
40
120
450
58.5
140
500
73
250
350
75
275
450
85.5
300
500
79.5
325
650
88
350
750
89
375
800
91
[0000]
TABLE 2
0.25 d/D Ratio Ring Test Results
Pump Rate
Standpipe
Flow Meter
(GPM)
pressure (PSI)
Rate (GPM)
300
250
57.5
325
300
65
350
400
69
375
450
75.6
400
525
81
425
600
85
[0000]
TABLE 3
0.39 d/D Ratio Ring Test Results
Pump Rate
Standpipe
Flow Meter
(GPM)
pressure (PSI)
Rate (GPM)
300
37
31.5
325
50
40.5
350
75
42.5
375
100
46.5
400
125
52
425
150
55.5
[0064] Plots of suction flow rate versus the pump flow rate are shown in FIGS. 9-11 for the 0.16 d/D, 0.25 d/D, and 0.39 d/D ratio rings, respectively.
[0065] Additionally, the 7⅞″ downhole debris recovery tool was tested to determine if the tool could lift heaving casing debris along with sand. The debris used in each test varied and included sand, metal debris, set screws, gravel, and o-rings. In one test, a packer plug retrieval/perforating debris cleaning trip after firing perforating guns was replicated. FIG. 12 shows the test step up for this part of the test. For this test, a packer plug fixture was placed in the casing and 125 lbs of sand was poured on top of the plug. Then, 10-20 lbs of perforating debris was poured on top of the sand. Fluid was pumped through the tool at 200 GPM. Once the test was completed, the debris removal cap was removed and the debris was collected and measured. The results of this part of the test are summarized in Tables 9 and 10 below for 0.25 d/D ratio ring and 0.16 d/D ratio, respectively, where TD is target depth.
[0000]
TABLE 4
Metal Debris Test - 200 GPM
Circulation
Pump
Pressure
Rate
Debris
Debris
RPM
Circulation Time
(PSI)
(GPM)
Dropped
Recovered
15-20
(7 mins to TD) 5 min
150-200
200-220
15 lbs steel
12 lbs steel
circulation after reaching
shavings;
shavings;
TD
100¼-20 screws;
13¼-20 screws;
100⅜-16
24⅜-16
screws
screws
[0000]
TABLE 5
Partial Sand Load and Metal Debris Test - 200 GPM
Circulation
Pump
Pressure
Rate
Debris
Debris
RPM
Circulation Time
(PSI)
(GPM)
Dropped
Recovered
15-20
(8 mins to TD) 5 min
150-200
220
15 lbs steel
115 lbs steel
circulation after reaching
shavings;
shavings,
TD (1 st trip)
100¼-20 screws;
sand, and
100⅜-16
rocks
screws; 150 lbs
sand; 100 lbs
rocks
15-20
(8 mins to TD) 5 min
400
305
Same
105 lbs steel
circulation after reaching
shavings,
TD (2 nd trip)
sand, and
rocks
[0000]
TABLE 6
Full Sand Load Test - 200 GPM
Circulation
Pump
Pressure
Rate
Debris
Debris
RPM
Circulation Time
(PSI)
(GPM)
Dropped
Recovered
15-20
(8 mins to TD)
150-200
222
300 lbs
170 lbs
5 min circulation
sand
sand
after reaching
TD (1 st trip)
15-20
(5 mins to TD)
400-500
410
Same
190 lbs
5 min circulation
sand
after reaching
TD (2 nd trip)
[0000]
TABLE 7
Partial Sand Load and O-ring Test - 200 GPM
Circulation
Pump
Pressure
Rate
Debris
Debris
RPM
Circulation Time
(PSI)
(GPM)
Dropped
Recovered
15-20
(5 mins to TD) 5 min
150-200
220
150 lbs sand; 8
108 lbs sand;
circulation after reaching
3″ o-rings; 5
10 0.75″ o-
TD (1 st trip)
plastic ring
rings; 1 plastic
chucks; 7 o-
ring chunks; 1
ring chunks;
o-ring chunk
10 0.75″ o-
rings
[0000]
TABLE 8
Partial Sand Load and Metal Debris Test - 400 GPM
Circulation
Pump
Pressure
Rate
Debris
Debris
RPM
Circulation Time
(PSI)
(GPM)
Dropped
Recovered
15-20
(7 mins to TD) 5 min
400-500
416
15 lbs steel
Less than 20 lbs
circulation after reaching
shavings;
sand,
TD (1 st trip)
100¼-20 screws;
gravel, metal
100/-16
shavings
screws; 150 lbs
sand; 100 lbs
rocks
15-20
(5 mins to TD) 5 min
400-500
410
Same
177 lbs steel
circulation after reaching
shavings,
TD (2 nd trip)
sand, rocks,
1⅜-16 screw
[0000]
TABLE 9
Packer Plug Perforation Debris Test with 0.25 d/D Ratio Ring
Circulation
Pump
Pressure
Rate
Debris
Debris
RPM
Circulation Time
(PSI)
(GPM)
Dropped
Recovered
15-20
(4 mins to TD) 2 min
150-200
250
15 lbs perf.
100 lbs
circulation after reaching
Gun debris
Sand and
TD (1 st trip)
125 lbs sand
some debris
15-20
(3 mins to TD) 2 min
400
400
Same
3.5 lbs steel
circulation after reaching
perf. Gun
TD (2 nd trip)
debris, some
sand
[0000]
TABLE 10
Packer Plug Perforation Debris Test with 0.16 d/D Ratio Ring
Circulation
Pump
Pressure
Rate
Debris
Debris
RPM
Circulation Time
(PSI)
(GPM)
Dropped
Recovered
15-20
(5 mins to TD) 5 min
650
325
15 lbs perf.
109 lbs
circulation after reaching
Gun debris
Sand and
TD (1 st trip)
125 lbs sand
some debris
15-20
(3 mins to TD) 5 min
700
350
Same
10 lbs steel
circulation after reaching
perf. Gun
TD (2 nd trip)
debris, some
sand
[0066] During these tests, a conventional debris removal tool was also tested and compared with the tool of the present invention. Generally, the downhole debris removal tool of the present disclosure had a lower overall operating pressure. It was also observed that the tool can be reciprocated to TD several times before pulling the string out of the hole to reduce the number of trips. The flow rates recorded during the tests were based on a 1.5 inch inlet on the bottom of the tool. It was also determined that the overall jet pump size could be increased to boost performance by reducing the O.D. of the jet pump sub.
[0067] From the results of the test performed, it was determined that the smaller the d or inner diameter of the jet, the stronger the suction at the suction tube and the higher the efficiency of the jet pump. However, it was observed that an inner diameter of the jet of 0.051″ or greater may result in lower suction flow velocity. In one test with a large d of 0.156″ (equivalent jet diameter) (d/D=0.39), the tool almost lost the ‘pump’ function. It was further noted that the larger the d/D ratio, that is, the ratio of the equivalent diameter of the jet to the inner diameter of the mixing tube, the weaker the sucking force. At low flow rates, conventional and the annular jet pump had higher efficiencies (20 GPM pumping flow rate). It was observed that if the overall size of the jet pump can be increased, the efficiency of the jet pump at higher rig pump rates can be increased due to lower turbulence values and friction losses in the jet pump itself. An advantage of the annular jet pump arrangement is that it will allow for the largest possible jet pump size for a given tool outer diameter due to its unique geometry.
[0068] Advantageously, embodiments of the present disclosure provide a downhole debris removal tool that includes a jet pump device to create a vacuum to suction fluid and debris from a wellbore. Further, the downhole debris removal tool of the present disclosure produces a venturi effect with maximum efficiency at low pump rates for removing debris from, for example, FIV valves and completion equipment. Additionally, the downhole debris removal tool of the present disclosure may be used in wellbores of varying sizes. That is, the annular size, or annulus space between the casing and the tool, may be insignificant. Embodiments of the present invention provide a downhole debris removal tool that can easily be field redressed and that allows verification of removed debris on the surface. Advantageously, special chemicals do not need to be pumped with the tool and high rig flow rates are not required for optimal clean up.
[0069] Further, embodiments disclosed herein advantageously provide an isolation valve for a downhole debris removal tool. In particular, an isolation valve in accordance with embodiments disclosed herein provides selective isolation of a debris sub to allow for connections between multiple segments of a debris sub and/or connections between the debris sub and other tools or components to be broken and made up with minimal spillage or leakage of debris and fluids contained within the debris sub. An isolation valve formed in accordance with the present disclosure may provide a safer and cleaner downhole debris removal tool.
[0070] Furthermore, embodiments disclosed herein advantageously provide a downhole debris removal tool having a drain pin. The drain pin formed in accordance with the present disclosure provides selective fluid communication between the debris sub and the suction tube to allow for fluid contained in the debris sub to be selectively disposed of through the suction tube. Selective disposal of the fluids contained within the debris sub may be performed on a rig floor after the downhole debris removal tool has been removed from the wellbore. Draining fluid from the tool may provide a safer working environment by reducing the risk of fluid spillage when disassembling components of the downhole debris removal tool.
[0071] Advantageously, embodiments disclosed herein provide a downhole debris removal tool including magnets disclosed on or proximate a screen disposed in the debris sub. Magnets disposed on or proximate the screen may attract metallic debris to the magnet or magnetic surface. Collection of the metallic debris on the magnets may prevent or reduce clogging the screen. Thus, embodiments disclosed herein may provide a more efficient downhole debris removal tool.
[0072] While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.
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A downhole debris recovery tool including a ported sub coupled to a debris sub, a suction tube disposed in the debris sub, and an annular jet pump sub disposed in the ported sub and fluidly connected to the suction tube is disclosed. A method of removing debris from a wellbore including the steps of lowering a downhole debris removal tool into the wellbore, the downhole debris removal tool having an annular jet pump sub, a mixing tube, a diffuser, and a suction tube, flowing a fluid through a bore of the annular jet pump sub, jetting the fluid from the annular jet pump sub into the mixing tube, displacing an initially static fluid in the mixing tube through the diffuser, thereby creating a vacuum effect in the suction tube to draw a debris-laden fluid into the downhole debris removal tool, and removing the tool downhole debris removal tool from the wellbore after a predetermined time interval is also disclosed. Further, an isolation valve including a housing, an inner tube disposed coaxially with the housing, and a gate, wherein the gate is configured to selectively close an annular space between the housing and the inner tube is disclosed.
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The subject matter of application Ser. No. 10/442,374 is incorporated herein by reference. The present application is a divisional of U.S. application Ser. No. 10/442,374, filed May 21, 2003, now U.S. Pat. No. 6,888,164 which claims priority to Japanese Patent Application No. JP2002-151322, filed May 24, 2002. The present application claims priority to these previously filed applications.
BACKGROUND OF THE INVENTION
The present invention relates to a display device and a method of manufacturing the same, and particularly to a liquid crystal display device and a method of manufacturing the same.
With characteristics of being thin and low power consumption, liquid crystal display devices are widely used in notebook computers, display devices for car navigation, personal digital assistants (PDAs), portable telephones and the like. The liquid crystal display device is roughly classified into a transmissive type that controls light from a backlight for display, a reflective type that reflects extraneous light such as sunlight or the like for display, or a recent display device referred to as a transflective type that combines characteristics of both the transmissive type and the reflective type.
Applications of these display devices require that the display devices consume low power, and therefore a high aperture ratio is required to maximize efficiency of use of the backlight. In the transflective type, a transmission part and a reflection part are formed in the same pixel, and thus multiple functions are incorporated within the pixel; it is therefore necessary to use space as effectively as possible.
In displaying an image on a liquid crystal display device, a scanning pulse is applied from a scanning line to a switching element, for example a TFT (Thin Film Transistor) provided for each pixel, and the switching element is turned on/off, whereby display pixels are selected. A signal corresponding to a video signal is applied to a data line, and then applied via a source and a drain of the TFT to electrodes that have a liquid crystal sandwiched therebetween, whereby light entering the liquid crystal is modulated to display the image.
Within a period until a next writing operation after a voltage corresponding to the video signal is written to each pixel, charge resulting from the voltage applied to the electrodes of the liquid crystal leaks through the liquid crystal and the switching element and is thus changed. In order to insure display picture quality, the applied voltage needs to be retained. Accordingly, an auxiliary capacitance (CS) sufficient as compared with the amount of leakage is generally formed in the liquid crystal display device.
FIG. 1 is an example of an equivalent circuit diagram of a conventional liquid crystal display device. FIG. 2 is a plan view of a configuration of the liquid crystal display device shown in FIG. 1 .
FIG. 1 shows an equivalent circuit of 2×3 pixels. One pixel in the equivalent circuit includes a liquid crystal element and electrodes having the liquid crystal element sandwiched therebetween, a transistor Tr as a switching element, and an auxiliary capacitance CS. Cc 11 to Cc 16 denotes a capacitance of a liquid crystal capacitor formed by a liquid crystal element and a display electrode and a common electrode having the liquid crystal element sandwiched therebetween. CS 1 to CS 6 denotes a capacitance value of the auxiliary capacitance of each pixel.
A plurality of scanning lines WLn−1, WLn, and WLn+1 are arranged in parallel with each other, and each connected to gate electrodes of transistors Tr 1 and Tr 4 , transistors Tr 2 and Tr 5 , or transistors Tr 3 and Tr 6 formed by TFTs, for example. The scanning lines WLn−1, WLn, and WLn+1 effect ON/OFF control of each of the transistors and thereby select pixels.
Data signal lines BLn−1, BLn, and BLn+1 arranged in parallel with each other apply a voltage corresponding to a video signal to each pixel. The data signal lines BLn−1, BLn, and BLn+1 are connected to for example a source region of the transistors Tr 1 , Tr 2 , and Tr 3 or the transistors Tr 4 , Tr 5 , and Tr 6 . The data signal lines BLn−1, BLn, and BLn+1 apply voltage to electrodes on both sides of liquid crystal elements in pixels selected by the scanning line WLn−1, WLn, or WLn+1 while charging auxiliary capacitances CS in the pixels, whereby light entering the liquid crystal elements is modulated to display an image.
FIG. 2 is a view of the configuration of scanning lines, data signal lines, and one pixel formed on a transparent substrate. As shown in FIG. 2 , the auxiliary capacitance CS 1 is formed on an auxiliary capacitance line CSLn−1 as one electrode of the auxiliary capacitance CS 1 . One impurity region, for example the source region of the transistor Tr 1 is connected to the data signal line BLn−1 via a conductive material deposited in a contact hole H 1 . Another impurity region, for example a drain region of the transistor Tr 1 is connected to another electrode formed by a semiconductor, for example, of the auxiliary capacitance CS 1 and an IT 0 electrode of an upper layer not shown in the figure via conductive material deposited in contact holes H 2 and H 3 .
An N-channel type thin film transistor TFT is generally used as the transistors Tr 1 , . . . , Tr 6 . Specifically, N-type source and drain impurity regions are formed by injecting phosphorus (P) or the like into semiconductor thin film on both sides of a gate electrode. When a positive voltage equal to or higher than a threshold value is applied to the gate electrode (scanning line), an N-channel formed by an N-type inversion layer is formed between the source and the drain, whereby the source and the drain are electrically connected to each other. That is, the transistor is in an ON state. When a voltage lower than the threshold value is applied to the gate electrode (scanning line), on the other hand, the channel for electrically connecting the source and the drain to each other is not formed, and therefore the transistor is in an OFF state.
The auxiliary capacitance CS 1 is generally formed by a MOS structure of a semiconductor layer, an insulating film, and a metal, which structure can form a highest capacitance. In FIG. 2 , the auxiliary capacitance CS 1 is for example formed by the auxiliary capacitance line CSLn−1 (metal), a gate insulating film forming the transistor Tr 1 , and the above-mentioned N-type semiconductor film having phosphorus or the like injected therein. Such a MOS capacitance will hereinafter be referred to as an N-type MOS structure.
When the electrodes of the auxiliary capacitance are to be set at a fixed potential, the auxiliary capacitance portion is generally made to be of the N-type MOS structure.
In a case of common-inversion driving in which auxiliary capacitance electrodes are oscillated in phase with a counter electrode, the semiconductor film forming the auxiliary capacitance CS does not form a sufficient capacitance in an intrinsic state. Therefore, the semiconductor layer is generally metalized, that is, made to contain a high concentration of phosphorus (made to be of an N+ type) or boron (made to be of a P+ type).
With the above conventional method, high-concentration injection of phosphorus (allowing the semiconductor layer to be of the N+ type) or boron (allowing the semiconductor layer to be of the P+ type) is required to be performed only once, and therefore manufacturing cost can be reduced.
However, the above structure requires an independent auxiliary capacitance line, thus presenting a problem of a decrease in an aperture ratio.
Accordingly, a CS-on-gate structure is proposed in which a scanning line (gate line) in a preceding stage or a succeeding stage also serves as the auxiliary capacitance line.
FIGS. 3A and 3B show another example of a conventional liquid crystal display device. FIG. 3A is an equivalent circuit diagram of the liquid crystal display device, and FIG. 3B is a plan view of a configuration of the liquid crystal display device. In FIGS. 3A and 3B , the same components as in FIG. 1 are designated by using the same reference numerals, and their repeated description will be omitted where appropriate.
FIG. 3A shows an equivalent circuit of 2×2 pixels. In FIG. 3A , auxiliary capacitances CS 1 , CS 4 , CS 2 , and CS 5 are directly connected to scanning lines WLn−1, WLn, and WLn+1 in place of the auxiliary capacitance lines CSLn−1, CSLn, and CSLn+1 shown in FIG. 1 .
FIG. 3B shows a configuration of scanning lines, data signal lines, and one pixel formed on a transparent substrate. The auxiliary capacitance CS 1 is formed so as to overlap the scanning line WLn in place of the auxiliary capacitance line CSLn−1 shown in FIG. 2 .
Also in this case, an N-channel type thin film transistor TFT is generally used as transistors Tr 1 , . . . , Tr 6 . Also, the auxiliary capacitance CS 1 is an N-type MOS capacitance. Specifically, when a positive voltage equal to or higher than a threshold value is applied to gate electrodes (scanning lines) of the transistors Tr 1 , . . . , Tr 6 , the transistors Tr 1 , . . . , Tr 6 are brought into an ON state. When a voltage lower than the threshold value is applied to the gate electrodes, the transistors Tr 1 , . . . , Tr 6 are brought into an OFF state.
As shown in FIG. 3B , the auxiliary capacitance CS 1 is formed by the scanning line WLn (metal), a gate insulating film forming the transistor Tr 1 , and an N-type semiconductor film having phosphorus or the like injected therein.
Such a CS-on-gate structure eliminates the need for forming the independent auxiliary capacitance line, and therefore has an advantage of increasing the aperture ratio.
In order to maintain the NMOS transistor Tr 1 in an off state, the potential of the scanning lines WLn−1, WLn, . . . may generally be set to about 0 V to −6 V. In addition, the transistor Tr 1 in the liquid crystal display device is maintained in the OFF state during most of a period of display of one screen. That is, the potential of the scanning lines is maintained at 0 V or lower during most of the display period.
However, in the case of the CS-on-gate structure as shown in FIGS. 3A and 3B , in which structure the auxiliary capacitance CS 1 is formed with the scanning line (gate line) WLn in the succeeding stage, for example, and the potential as described above is applied, the N-type MOS structure formed by the scanning line, the gate insulating film, and the N-type semiconductor film cannot provide a sufficient capacitance.
FIG. 4 is a graph showing capacitance-voltage characteristics of the N-type MOS structure.
When −2 V, for example, is applied to the scanning lines WLn−1 and WLn shown in FIG. 3B and thereby Tr 1 is maintained in an OFF state, since CS 1 is charged while Tr 1 is in an ON state, the semiconductor electrode of CS 1 is at a higher potential than the scanning lines WLn−1 and WLn, and the gate voltage applied to CS 1 is a negative voltage. This causes majority carrier electrons to be repelled from a surface of the semiconductor film and a depletion layer (and/or an inversion layer) to be formed on the surface of the semiconductor film, which corresponds to an increase in thickness of the insulating layer of CS 1 . Thus, a resulting capacitance is small.
This tendency is shown in FIG. 4 . When the scanning potential is used in a range of about 1.5 V and lower, only a small capacitance is provided by the N-type MOS capacitance at all times.
In order to increase the capacitance of the auxiliary capacitance CS 1 , phosphorus (for making an N+ type) or boron (for making a P+ type) needs to be injected at a high concentration into the semiconductor film electrode of the auxiliary capacitance CS 1 . This causes problems of an increase in the number of processes, a decrease in yield resulting from occurrence of defects, and the like.
FIGS. 5A to 7B illustrate an example of a process of manufacturing the conventional liquid crystal display device.
In FIG. 5A , gate electrodes (scanning lines) 102 a and 102 b serving as scanning lines are formed on a glass substrate 101 . A metal such as Ta, Cr, Mo, Ti, Al or the like is used for the material of the gate electrodes, and the pattern is formed by wet etching or dry etching following a photoresist process.
In FIG. 5B , an gate insulating film 103 and a semiconductor layer 104 a are formed over the gate electrodes 102 a and 102 b . Examples of the gate insulating film 103 include silicon nitride film and silicon oxide film, as well as anodized film obtained by anodizing a gate electrode and the like. As the semiconductor film, amorphous silicon film, polysilicon film obtained by crystallizing amorphous silicon film, polysilicon film formed directly, or the like is used.
In FIG. 5C , a protective insulating film 105 is formed on the semiconductor film 104 a . As the protective insulating film 105 , silicon nitride film, silicon oxide film or the like is used.
In FIG. 5D , resists 107 a and 107 b are formed in a self-aligning manner with the gate electrodes 102 a and 102 b serving as a light shield mask. The protective insulating film 105 is thereafter removed by wet etching or dry etching. Then, using remaining protective insulating films 105 a and 105 b as a mask, the semiconductor film is doped with phosphorus (P) or the like at a low concentration. A doped portion of the semiconductor film is denoted as 104 b . The semiconductor film 104 b is an n − type semiconductor.
In FIG. 6A , a resist 108 having such a shape as to cover a portion forming an LDD region in the pixel transistor is formed. In order to remove the protective insulating film 105 b remaining in a portion where the auxiliary capacitance is formed, wet etching or dry etching is thereafter performed.
Then, phosphorus or the like is injected at a high concentration to thereby metalize the semiconductor layer 104 b . A metalized portion of the semiconductor film 104 b is denoted as 104 c.
Though not shown in the figures, a photoresist process and an injection process are carried out according to a portion for injection of a second type of dope (boron or the like). Thereafter heat treatment is performed as required to activate doped elements.
The wet etching or the dry etching is usually performed by a process with etching selectivity to protect the semiconductor layer 104 b from the etching. However, when there is a pin hole or the like in the semiconductor layer 104 b , the gate insulating film 103 serving as a base is etched. The etched portion, being greatly deteriorated in terms of withstand voltage, forms a path of current leakage, and causes a defect such as a point defect or the like. Besides, the process for removing the protective insulating film 105 b is added, which represents a cost increasing factor.
In FIG. 6B , for device isolation, the semiconductor layer 104 c on the outside of the gate electrodes 102 a and 102 b is removed using means such as photolithography, dry etching or the like.
In FIG. 6C , an interlayer insulating film 109 is formed by silicon nitride film, silicon oxide film or the like. Thereafter contact holes 110 a and 110 b are formed using means such as photolithography, wet etching or the like.
In FIG. 7A , a metal such as Al, Ta, W or the like is formed as data signal lines 111 a and 111 b and a connecting metal 112 for connection with a pixel electrode. Thereafter the metal is removed using means such as photolithography, dry etching or the like, whereby a pattern is formed.
In FIG. 7B , a second interlayer insulating film 113 is formed by silicon nitride film, silicon oxide film or the like. In order to provide this layer with a flattening effect, a photosensitive organic film, a photosensitive SOG (spin on glass) film or the like may be used. Also in this process, a contact hole for connection with the pixel electrode 114 is formed. Thereafter the pixel electrode 114 is formed using a transparent conductive film of ITO, IXO or the like.
Then, though not shown in the figures, a corresponding color filter substrate prepared separately is superposed on the TFT substrate, an assembly process is carried out with a liquid crystal layer sandwiched between the color filter substrate and the TFT substrate, and further a polarizer and the like are attached, whereby the liquid crystal display device is completed.
Thus, with the conventional manufacturing method, a special process is required to complete the structure of the auxiliary capacitance, which constitutes a cost increasing factor, and also leakage current that causes defects is increased. There are conventionally problems of such an increase in the number of processes and a decrease in yield resulting from occurrence of defects.
While a conventional example of the bottom gate type transistor in which the scanning line (gate electrode) is formed under the semiconductor layer has been described above, there are also problems in a method of manufacturing the top gate type transistor in which the scanning line (gate electrode) is formed above the semiconductor layer.
FIGS. 8A , 8 B, and 8 C and FIGS. 9A and 9B illustrate a conventional example of a method of manufacturing a liquid crystal display device having the structure of the top gate type transistor.
As shown in FIG. 8A , a base layer 122 and a semiconductor layer 123 a are formed on a glass substrate 121 . As the base layer 122 , silicon nitride film or silicon oxide film, for example, is used. As the semiconductor layer 123 a , amorphous silicon film, polysilicon film obtained by crystallizing amorphous silicon film, polysilicon film formed directly, or the like is used.
As shown in FIG. 8B , in order to obtain a region for device isolation, a part of the semiconductor layer 123 a is removed using means such as photolithography, dry etching or the like.
A gate insulating film 124 is then formed on the semiconductor film 123 a . Examples of the gate insulating film include silicon nitride film, silicon oxide film and the like.
Then, gate electrodes 125 a and 125 b are formed in a region for forming a transistor TFT and a region for forming an auxiliary capacitance.
Next, the semiconductor film is doped with phosphorus or the like at a low concentration in a self-aligning manner with the gate electrodes 125 a and 125 b serving as an injection mask. A doped portion of the semiconductor film is an n − type semiconductor, and is denoted as 123 b.
As shown in FIG. 8C , a resist 126 having such a shape as to cover a portion forming an LDD region in the pixel transistor TFT is formed. Phosphorus or the like is injected into other regions at a high concentration to thereby metalize the semiconductor layer 123 b . The metalized portion of the semiconductor film 123 b is denoted as 123 c.
Though not shown in the figures, a photoresist process and an injection process are carried out according to a portion for injection of a second type of dope (boron or the like). Thereafter heat treatment is performed as required to activate doped elements.
In FIG. 9A , an interlayer insulating film 127 is formed by silicon nitride film, silicon oxide film or the like. Thereafter contact holes 128 a and 128 b are formed using means such as photolithography, wet etching or the like.
In FIG. 9B , a metal such as Al, Ta, W or the like is formed as data signal lines 129 a and 129 b and a connecting metal 130 for connection with a pixel electrode 132 . Thereafter the metal is removed using means such as photolithography, dry etching or the like, whereby a pattern is formed.
Then, a second interlayer insulating film 131 is formed by silicon nitride film, silicon oxide film or the like. In order to provide this layer with a flattening effect, a photosensitive organic film, a photosensitive SOG (spin on glass) film or the like may be used. Also in this process, a contact hole for connection with the pixel electrode 132 is formed. Thereafter the pixel electrode 132 is formed using a transparent conductive film of ITO, IXO or the like.
Then, though not shown in the figures, a corresponding color filter substrate prepared separately is superposed on the TFT substrate, an assembly process is carried out with a liquid crystal layer sandwiched between the color filter substrate and the TFT substrate, and further a polarizer and the like are attached, whereby the liquid crystal display device is completed.
As shown in FIGS. 8B and 8C , the above structure has the gate electrode 125 b formed in a region for forming the auxiliary capacitance. Therefore no impurity can be injected into the semiconductor film 123 a under the gate electrode 125 b , and the semiconductor film 123 a under the gate electrode 125 b cannot be metalized. In order to solve this problem within the scope of the conventional method, it is necessary to add processes of forming a mask, performing injection, and then removing the mask in an initial stage, or form an independent auxiliary capacitance line as shown in FIG. 1 .
SUMMARY OF THE INVENTION
The present invention has been made in view of the above problems, and it is an object of the present invention to provide a display device with a high aperture ratio and a large auxiliary capacitance and a method of manufacturing the display device without increasing manufacturing processes.
According to an aspect of the present invention, there is provided a display device including: a display element; a first scanning line; a second scanning line; a data signal line; a switching element having a first terminal and a second terminal of a first conduction type, the first terminal being connected to the data signal line, for being held in a conducting state or a non-conducting state according to a voltage applied to the first scanning line; and a storage capacitance having a first electrode and a second electrode that shares the second scanning line; wherein the second terminal of the switching element is connected to the display element and connected to the first electrode of the storage capacitance including a semiconductor film of a second conduction type different from the second terminal.
While the switching element is held in the conducting state, the storage capacitance is charged from the data signal line via the switching element, and while the switching element is held in the non-conducting state, the storage capacitance applies a voltage to the display element.
The second terminal of the switching element and the first electrode of the storage capacitance are connected to each other by a conductive material.
Specifically, the second terminal of the switching element and the first electrode of the storage capacitance are connected to each other by a conductive material deposited in a contact hole reaching the second terminal of the switching element and a contact hole reaching the first electrode of the storage capacitance.
Alternatively, the second terminal of the switching element and the first electrode of the storage capacitance are connected to each other by a conductive material deposited in a contact hole reaching the second terminal of the switching element and the first electrode of the storage capacitance.
Preferably, the conductive material for connecting the second terminal of the switching element and the first electrode of the storage capacitance to each other is identical with a conductive material used for the data signal line.
Further, preferably, a part or a whole of the storage capacitance is formed between the data signal line and the second scanning line in a region where the data signal line and the second scanning line overlap each other.
According to a second aspect of the present invention, there is provided a display device including: a plurality of first scanning lines and second scanning lines; a plurality of data signal lines; a plurality of pixels arranged in a form of a matrix; and a driving circuit for driving the plurality of pixels; wherein the driving circuit for driving each of the pixels includes: a switching element having a first terminal and a second terminal of a first conduction type, the first terminal being connected to the data signal line, for being held in a conducting state or a non-conducting state according to a voltage applied to the first scanning line; and a storage capacitance having a first electrode and a second electrode that shares the second scanning line; and the second terminal of the switching element is connected to a display element and connected to the first electrode of the storage capacitance including a semiconductor film of a second conduction type different from the second terminal.
Preferably, the switching element is a thin film transistor having polycrystalline silicon as a semiconductor layer.
According to a third aspect of the present invention, there is provided a method of manufacturing a display device, the method including the steps of: forming a conductive first scanning line and a conductive second scanning line arranged in parallel with each other, a first insulating film covering the first scanning line and the second scanning line, and a semiconductor film covering the first insulating film; forming a first protective mask and a second protective mask for protecting a first channel region and a second channel region, respectively, of the semiconductor film, the first channel region and the second channel region being opposed to the first scanning line and the second scanning line, respectively; and injecting an impurity of a first conduction type and an impurity of a second conduction type into a switching element region for forming a switching element including the first scanning line and a storage capacitance region for forming a storage capacitance including the second scanning line, respectively, in the semiconductor film, in a state in which the first protective mask and the second protective mask are formed.
According to the present invention, there may be provided a method of manufacturing a display device, the method including the steps of: forming a second insulating film so as to cover the semiconductor film having the switching element region and the storage capacitance region injected with the impurity of the first conduction type and the impurity of the second conduction type, respectively, and the first protective mask and the second protective mask; forming, in the second insulating film, a first contact hole and a third contact hole reaching semiconductor regions of the first conduction type on both sides of the first scanning line; forming, in the second insulating film, a second contact hole reaching a semiconductor region of the second conduction type on one side of the second scanning line; connecting the semiconductor region of the first conduction type on one side of the first scanning line with the semiconductor region of the second conduction type on one side of the second scanning line by depositing a conductive material in the first contact hole and the second contact hole; and forming a data signal line by depositing a conductive material in the third contact hole.
Preferably, the first contact hole is a same contact hole as the second contact hole.
Further, preferably, the conductive material deposited in the first contact hole and the second contact hole is a same material as the conductive material deposited in the third contact hole.
Further, according to a fourth aspect of the present invention, there is provided a method of manufacturing a display device, the method including the steps of: forming a semiconductor film, an insulating film covering the semiconductor film, and a conductive first scanning line and a conductive second scanning line arranged in parallel with each other on the insulating film; and injecting, from a side of the first scanning line and the second scanning line, an impurity of a first conduction type and an impurity of a second conduction type into a switching element region for forming a switching element including the first scanning line and a storage capacitance region for forming a storage capacitance including the second scanning line, respectively, in the semiconductor film.
According to the present invention described above, in the semiconductor film, the conduction type of a source and drain region of a transistor (the conduction type of a channel between the source and drain, so to speak) is opposite to the conduction type of a semiconductor film region for forming an auxiliary capacitance. When the conduction type of the source and drain region of the transistor and the channel is an N-type, for example, the semiconductor film region for forming the auxiliary capacitance is made to be of a P-type. Thus, by applying a scanning line voltage (zero or negative) that turns off the N-channel transistor to the auxiliary capacitance of a P-type MOS structure, a large capacitance is obtained. Also, when the conduction type of the source and drain region of the transistor and the channel is the P-type, and when the semiconductor film region for forming the auxiliary capacitance is made to be of the N-type, the same effects are obtained.
In addition, at the time of injection of impurities to form the above structure, it suffices only to inject different types of impurities, and therefore manufacturing processes are not increased.
Further, since the above structure provides a sufficient capacitance, at the time of injection of an impurity into the region of the semiconductor film for forming the auxiliary capacitance, a mask for protecting a channel forming region of the semiconductor film which region is opposed to the scanning line does not need to be removed by etching. Thus defect causing factors are reduced.
According to the present invention, a conventionally impossible structure of a switching transistor and an auxiliary capacitance is made possible, which increases the auxiliary capacitance and improves an aperture ratio.
In manufacturing the display device according to the present invention, an effective auxiliary capacitance can be formed without an increase in the number of processes or with a small number of processes.
In addition, since the number of times that the surface of the semiconductor layer is exposed to wet etching and dry etching is reduced, it is possible to reduce a rate of occurrence of defects such as a leakage current between the semiconductor layer and the gate electrode for the auxiliary capacitance and the like, thereby improving yield.
The present invention reduces a non-transparent region, and can thereby increase the aperture ratio greatly. It is accordingly possible to reduce backlight brightness and thus reduce power consumption.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an equivalent circuit of an example of a conventional display device;
FIG. 2 is a plan view of a configuration of the conventional display device shown in FIG. 1 ;
FIG. 3A shows an equivalent circuit of another example of a conventional display device having a bottom gate structure, and FIG. 3B is a plan view of a configuration of the display device;
FIG. 4 is a graph showing a result of measurement of voltage-capacitance characteristics of an auxiliary capacitance in the conventional display device shown in FIGS. 3A and 3B ;
FIGS. 5A , 5 B, 5 C, and 5 D are sectional views of assistance in explaining a method of manufacturing the conventional display device shown in FIGS. 3A and 3B ;
FIGS. 6A , 6 B, and 6 C are sectional views, continued from FIGS. 5A , 5 B, 5 C, and 5 D, showing assistance in explaining the method of manufacturing the conventional display device shown in FIGS. 3A and 3B ;
FIGS. 7A and 7B are sectional views, continuing from FIGS. 6A , 6 B, and 6 C, showing assistance in explaining the method of manufacturing the conventional display device shown in FIGS. 3A and 3B ;
FIGS. 8A , 8 B, and 8 C are sectional views of assistance in explaining a method of manufacturing a conventional display device having a top gate structure;
FIGS. 9A and 9B are sectional views, continuing from FIGS. 8A , 8 B, and 8 C, showing assistance in explaining the method of manufacturing the conventional display device having the top gate structure;
FIG. 10A shows an equivalent circuit of a display device according to a first embodiment of the present invention, and FIG. 10B is a plan view of a configuration of the display device;
FIG. 11 is a sectional view of a structure of the display device according to the first embodiment of the present invention;
FIGS. 12A , 12 B, and 12 C are timing charts of scanning line signals and pixel potential in the display device according to the first embodiment of the present invention;
FIG. 13 is a graph showing a result of measurement of voltage-capacitance characteristics of an auxiliary capacitance in the display device according to the first embodiment of the present invention;
FIGS. 14A and 14B are sectional views of assistance in explaining a method of manufacturing the display device according to the first embodiment of the present invention;
FIG. 15 is a diagram showing a driving circuit in the display device according to the first embodiment of the present invention;
FIG. 16 is a plan view of a configuration of a display device according to a second embodiment of the present invention;
FIG. 17 is a sectional view of the configuration of the display device according to the second embodiment of the present invention;
FIG. 18 is a plan view of a configuration of a display device according to a third embodiment of the present invention;
FIG. 19 is a sectional view of a configuration of a display device according to a fourth embodiment of the present invention; and
FIGS. 20A and 20B are sectional views of assistance in explaining a method of manufacturing the display device according to the fourth embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Preferred embodiments of a display device and a method of manufacturing the same according to the present invention will hereinafter be described with reference to the accompanying drawings by taking a liquid crystal display device as an example.
First Embodiment
FIGS. 10A and 10B are diagrams showing an equivalent circuit and a configuration of a liquid crystal display device according to a first embodiment. The circuit arrangement diagram of FIG. 10A is similar to that of the conventional example shown in FIG. 3A . However, in FIG. 10A , a conduction type of semiconductor film possessed by auxiliary capacitances PCS 1 , PCS 2 , PCS 4 , and PCS 5 is different from a conduction type of transistors NTr 1 , NTr 2 , NTr 4 , and NTr 5 . In this example, the transistors NTr 1 , NTr 2 , NTr 4 , and NTr 5 are formed by an N-channel TFT, and the auxiliary MOS capacitances are formed by a P-type MOS structure. That is, the auxiliary MOS capacitances are formed by a scanning line (metal), a gate insulating film, and a P-type semiconductor film.
The conduction types may be changed to form the transistors by a P-channel type TFT and the auxiliary capacitances by an N-type MOS structure.
FIG. 10A shows an equivalent circuit of 2×2 pixels. A plurality of scanning lines WLn−1, WLn, and WLn+1 in FIG. 10A are arranged in parallel with each other, and each connected to gate electrodes of the transistors NTr 1 and NTr 4 or the transistors NTr 2 and NTr 5 formed by N-channel TFTS, for example. The scanning lines WLn−1, WLn, and WLn+1 effect ON/OFF control of each of the transistors and thereby select pixels to be operated.
The auxiliary capacitances PCS 1 , PCS 2 , PCS 4 , and PCS 5 of the P-type MOS structure each formed by a scanning line, a gate insulating film, and a P-type semiconductor film are each directly connected to the scanning line WLn or WLn+1.
Data signal lines BLn−1, BLn, and BLn+1 arranged in parallel with each other for applying a voltage corresponding to a video signal to each pixel are connected to one impurity region, for example a source region of the transistors NTr 1 and NTr 2 or the transistors NTr 4 and NTr 5 . The data signal lines BLn−1, BLn, and BLn+1 apply voltage to electrodes of liquid crystal elements in pixels selected by the scanning line WLn−1, WLn, or WLn+1 while charging the auxiliary capacitances PCS of the P-type MOS structure, whereby light entering the liquid crystals is modulated to display an image.
FIG. 10B is a plan view of the configuration of scanning lines, data signal lines, and one pixel formed on a transparent substrate. In FIG. 10B , the P-type MOS auxiliary capacitance PCS 1 shown in FIG. 10A is formed on the scanning line WLn with an intermediate gate insulating film not shown in the figure.
One impurity region, for example a source region of the N-channel type transistor NTr 1 is connected to the data signal line BLn−1 via a conductive material deposited in a contact hole H 1 . Another impurity region, for example a drain region of the N-channel type transistor NTr 1 is connected to the semiconductor film of the auxiliary capacitance PCS 1 and an ITO electrode of an upper layer not shown in the figure via conductive materials deposited in contact holes H 2 and H 3 .
FIG. 11 is a schematic sectional view of the pixel structure shown in FIG. 10B . FIG. 10B is a sectional view taken along a semiconductor layer pattern from the data signal line to the auxiliary capacitance. Because of limited space, however, the TFT transistor portion is shown having a single gate structure rather than a double gate structure in which transistors are arranged in series.
In FIG. 11 , scanning lines 1 a and 1 b (WLn−1 and WLn) are formed on the transparent substrate not shown in the figure, a gate insulating film 2 is formed so as to cover the scanning lines 1 a and 1 b , and semiconductor films 3 , 4 , 5 , and 6 are formed on the gate insulating film 2 , whereby the TFT transistor and the auxiliary capacitance are formed.
In the semiconductor film, reference numeral 3 denotes an N + semiconductor region having a high concentration of phosphorus (P), for example, injected therein, and reference numeral 4 denotes a P + semiconductor region having a high concentration of boron (B), for example, injected therein. A center of the semiconductor film 5 is a so-called i-type semiconductor film without an impurity injected therein, and both sides of the semiconductor film 5 are an LDD region having a low concentration of phosphorus (P), for example, injected therein. The semiconductor film 5 forms a channel region of the TFT transistor. In the example of FIG. 11 , this semiconductor film forms an N-channel region. Reference numeral 6 also denotes a so-called i-type semiconductor film without an impurity injected therein.
References 7 a and 7 b denote stopper films formed so as to prevent impurity injection into the i-type semiconductor films 5 and 6 under the stopper films. Reference numeral 8 denotes an interlayer insulating layer.
Contact holes are formed in the interlayer insulating layer 8 on the N + semiconductor region 3 and the P + semiconductor region 4 . A conductive material in the contact holes forms a connecting electrode 10 for connecting the N + semiconductor region 3 and the P + semiconductor region 4 to each other. The conductive material also forms a data signal line 9 .
The gate electrode 1 a , the gate insulating film 2 , and the semiconductor films 4 and 5 form the N-channel type TFT transistor. On the other hand, the gate electrode 1 b , the gate insulating film 2 , and the semiconductor films 4 and 6 form a P-channel type transistor. A capacitance of the P-channel type transistor is used as the auxiliary capacitance.
As to conduction of the N + semiconductor region 3 and the P + semiconductor region 4 , when the N + semiconductor region 3 and the P + semiconductor region 4 are directly connected to each other, a PN junction occurs between the N + semiconductor region 3 and the P + semiconductor region 4 , thus causing a potential loss. It is accordingly desirable to make a connection from the N + semiconductor region 3 to the P + semiconductor region 4 via a metal. In the first embodiment, the metal is deposited in the contact hole for connection to the N + type semiconductor 3 and the contact hole for connection to the P + type semiconductor 4 , whereby the connecting electrode 10 is formed to connect the N + semiconductor region 3 and the P + semiconductor region 4 to each other.
It is desirable that a material for the connecting electrode 10 be a material used for the data signal line 9 . The use of the same metal as that of the data signal line 9 eliminates the need for a special process for the connection, and thus enables manufacturing at a lower cost.
As another metal for the connection, a pixel electrode ( FIG. 7B and FIG. 9B ) may be used.
However, the contact holes are not necessarily required; a metallic layer may be formed directly on the N + type semiconductor 3 and the P + type semiconductor 4 .
FIGS. 12A , 12 B, and 12 C are timing charts of scanning line voltage applied to the scanning lines WLn−1, WLn, and WLn+1 in the liquid crystal display device according to the first embodiment as shown by FIG. 10A . Vdd and Vssg in FIG. 12A denote voltages for bringing the TFT transistor of each pixel into an ON state and an OFF state, respectively. As an example, Vdd=13 V and Vssg=−2 V.
In FIG. 12B , a broken line indicates a potential of a common electrode, and an irregular line indicates timing of change in a pixel potential.
As shown in FIGS. 12A , 12 B, and 12 C, in displaying an image, the scanning lines WLn−1, WLn, WLn+1, . . . sequentially output a high-level voltage signal (Vdd) to the transistors NTr 1 , NTr 4 , NTr 2 , NTr 5 of the pixels, and thereby turn on the transistors to operate the pixels.
For display of one screen, each pixel is operated only once. Therefore a period when the scanning line voltage is Vdd is far shorter than a period when the scanning line voltage is Vssg, and each transistor is maintained in an OFF state during most of a period of display of one screen. That is, the voltage of −2 V is applied to the scanning lines WLn−1, WLn, and WLn+1 during most of the display period.
Thus, the voltage of −2 V is applied to the metallic electrode (scanning line) of the P-type MOS auxiliary capacitance PCS 1 , for example, shown in FIGS. 10A and 10B and FIG. 11 during most of the period.
As for another electrode including the P-type semiconductor film of the auxiliary capacitance PCS 1 , on the other hand, when the transistor NTr 1 is in an ON state, a high-level signal from the data signal line BLn−1 applies a voltage to electrodes on both sides of the liquid crystal while charging the auxiliary capacitance PCS 1 via the source and drain of the transistor NTr 1 . Since the auxiliary capacitance PCS 1 is charged, a potential of the semiconductor film electrode of the auxiliary capacitance PCS 1 is higher than Vssg. When the transistor NTr 1 is in an OFF state, the source and drain of the transistor NTr 1 are disconnected from each other, and therefore a signal from the data signal line BLn−1 does not supply a voltage to the liquid crystal and the auxiliary capacitance PCS 1 . The auxiliary capacitance PCS 1 supplies a voltage to the electrodes on both sides of the liquid crystal.
As shown in the graph of the pixel potential of FIG. 12B , while the potential of the semiconductor film of the auxiliary capacitance PCS 1 (the same as the pixel potential) is gradually lowered and raised, the potential is higher than Vssg at all times. Then, a voltage Vg from the metal side (scanning line side) to the semiconductor film of the auxiliary capacitance PCS 1 is negative at all times.
As already described with reference to the graph of FIG. 4 , when such a voltage Vg is applied to an N-type MOS capacitance comprising a scanning line (metal), a gate insulating film, and an N-type semiconductor film, since majority carriers of the N-type semiconductor are electrons, the negative scanning line voltage (or the voltage Vg) causes the majority carriers to be repelled from a surface of the semiconductor film and a depletion layer (and/or an inversion layer) to be formed, which corresponds to an increase in thickness of the insulating layer of the auxiliary capacitance. Thus, as shown in FIG. 4 , a resulting capacitance is small.
FIG. 13 is a graph showing capacitance-voltage characteristics of a P-type MOS structure.
In the P-type MOS capacitance comprising a scanning line (metal), a gate insulating film, and a P-type semiconductor film, since majority carriers of the P-type semiconductor are holes, the negative scanning line voltage (or the voltage Vg) does not cause a depletion layer to be formed but instead causes the majority carriers to be gathered on a surface of the P-type semiconductor film. Thereby, as shown in FIG. 13 , a large capacitance is obtained.
Thus, with the first embodiment, a sufficient capacitance is formed in a use range (the period when the scanning line voltage is Vssg) in normal driving conditions.
Thus, in general, when an N-channel type pixel transistor is formed, the auxiliary capacitance needs to be formed by a P-type MOS capacitance. When a P-channel type pixel transistor is formed, it is desirable that the auxiliary capacitance be formed by an N-type MOS capacitance.
While in the first embodiment, the auxiliary capacitance is formed with the scanning line (gate line) WLn in the next stage, the auxiliary capacitance may be formed with a scanning line (gate line) WLn−2 in a preceding stage.
Conventionally, when the scanning line WLn forming the auxiliary capacitance is raised to a high level, the pixel potential is substantially shifted. With the P-type MOS capacitance as in the first embodiment, when the scanning line WLn is raised to a high level, the P-type MOS capacitance is effectively decreased, and an amount of shift is decreased, as shown in FIG. 12B . Thereby display quality is improved.
FIGS. 14A and 14B illustrate a method of manufacturing the liquid crystal display device according to the first embodiment. The manufacturing method according to the first embodiment is obtained by changing the conventional process shown in FIG. 6A in the conventional manufacturing method shown in FIGS. 5A to 5D , FIGS. 6A to 6C , and FIGS. 7A and 7B .
Following the process of FIG. 5D , in FIG. 14A , phosphorus is injected at a high concentration in the vicinity of the TFT transistor to thereby form the N + semiconductor region 3 and thus metalize the semiconductor layer. At this time, a resist 11 b is formed so as to prevent the high-concentration injection of phosphorus in the vicinity of the auxiliary capacitance. Thus, as in the process of FIG. 5D , an N − type semiconductor region 4 a is formed around the auxiliary capacitance after the high-concentration injection of phosphorus.
In addition, the conventional process of removing the protective insulating film on the auxiliary capacitance is not required.
In FIG. 14B , the resist pattern 11 b in the vicinity of the auxiliary capacitance is removed, and boron is injected at a high concentration around the auxiliary capacitance to thereby form a P + type semiconductor region 4 b . At this time, a resist 11 c is formed so as to prevent the high-concentration injection of boron in the vicinity of the TFT transistor.
Thereafter heat treatment is performed as required to activate doped elements.
As described above, the liquid crystal display device according to the first embodiment includes an element of a first conduction type and a MOS structure of a second conduction type. The use of such elements of the two conduction types allows a CMOS type driving circuit or logical circuit to be formed in a display pixel region, a region outside of the display pixel region, or both the regions.
FIG. 15 shows an example of configuration of a display device in which each pixel is driven by such CMOS. In FIG. 15 , a plurality of scanning lines arranged in parallel with each other and a plurality of data signal lines arranged in parallel with each other are driven by a scanning line driving circuit and a data signal line driving circuit, respectively, and each of pixels arranged in a form of a matrix is driven by a driving circuit formed by an N-channel TFT and a P-type MOS capacitance, for example.
A liquid crystal display device having such a circuit can be formed by a method as in the first embodiment without addition of a special process, and is therefore a most suitable configuration example. For example, it is desirable to use the first embodiment in a polysilicon transistor liquid crystal display device using a polysilicon film with a high mobility as a semiconductor, or the like.
According to the first embodiment, a sufficient auxiliary capacitance is obtained in a use range (the period when the scanning line voltage is Vssg) in normal driving conditions. In addition, since the auxiliary capacitance can be formed by the CS-on-gate structure, a high aperture ratio is obtained.
Further, with the method of manufacturing the liquid crystal device according to the first embodiment, processes in which the semiconductor layer is exposed to etching are reduced, and thereby defects and the like are decreased.
Second Embodiment
In a second embodiment, another example of configuration of the liquid crystal display device according to the present invention will be shown.
FIG. 16 and FIG. 17 are a plan view and a schematic sectional view of the configuration of the liquid crystal display device according to the second embodiment.
The liquid crystal display device shown in FIG. 16 and FIG. 17 are basically of the same configuration as shown in FIG. 10B and FIG. 11 . Therefore repeated description in the second embodiment will be omitted where appropriate, and in FIG. 16 and FIG. 17 , the same references are used for the same components as in FIG. 10B and FIG. 11 .
There is a difference between FIG. 16 and FIG. 10B , and between FIG. 17 and FIG. 11 in that the contact holes H 2 and H 3 shown in FIG. 10B for connecting the N + type semiconductor 3 and the P + type semiconductor 4 to each other are combined into one contact hole H 4 in FIG. 16 . The connecting electrode 10 shown in FIG. 11 formed by depositing a conductive material in the two contact holes is converted into a connecting electrode 30 in FIG. 17 formed by a conductive material deposited in the same contact hole.
It is desirable that contacts for connecting the N + type semiconductor 3 and the P + type semiconductor 4 to each other are to be the same contact hole extending over both the conduction types. By combining the contact holes into one, an area within the pixel can be utilized effectively, thus improving the aperture ratio.
Third Embodiment
In a third embodiment, another example of configuration of the liquid crystal display device according to the present invention will be shown.
FIG. 18 is a plan view of the configuration of the liquid crystal display device according to the third embodiment.
In FIG. 18 , the same references are used for the same components as in FIG. 16 and FIG. 11 .
There is a difference between FIG. 18 and FIG. 11 and FIG. 16 in that a part of an auxiliary capacitance PCS 1 in FIG. 18 is disposed under a data signal line BLn−1.
In this case, a region required for forming the necessary auxiliary capacitance is formed in a region where light does not pass through originally, for example a metal region (data signal line in this case). Therefore a loss in transmittance becomes smaller, and thus a high aperture ratio can be secured.
Either of a bottom gate type transistor structure and a top gate type transistor structure may be formed in this case.
When the auxiliary capacitance PCS 1 is formed under the data signal line BLn−1 in the bottom gate structure shown in FIG. 18 , a protective insulating film is left on the semiconductor layer, so that a coupling capacitance between the signal line and the semiconductor film is decreased. This improves display quality in terms of crosstalk and the like.
In addition, since the coupling capacitance between the signal line and the electrode under the signal line is decreased, a total signal line capacitance is decreased, and thus rounding of signal line potential is reduced, thereby improving display quality.
Fourth Embodiment
While the bottom gate type transistor structure has been described as an example, the present invention is also applicable to the top gate type transistor structure.
FIG. 19 is a sectional view of an example of configuration of a liquid crystal display device of the top gate structure according to a fourth embodiment.
In the liquid crystal display device of FIG. 19 , semiconductor films 43 , 44 , 45 , and 46 are formed on a base layer not shown in the figure formed on a transparent substrate not shown in the figure, a gate insulating film 42 is formed on the semiconductor films, and further scanning lines 41 a and 41 b (WLn−1 and WLn) and an interlayer insulating film 48 are formed on the gate insulating film 42 . Thereby a TFT transistor and an auxiliary capacitance are formed.
Reference numeral 43 denotes an N + semiconductor region, and reference numeral 44 denotes a P + semiconductor region. A center of the semiconductor film 45 is an i-type semiconductor film, and both sides of the semiconductor film 45 are an LDD region. The semiconductor film 45 forms a channel region of the TFT transistor. In the example of FIG. 19 , this semiconductor film forms an N-channel region. Reference numeral 46 also denotes an i-type semiconductor film.
Reference numeral 46 also denotes a so-called i-type semiconductor film without an impurity injected therein. Contact holes are formed in the interlayer insulating layer 48 on the N + semiconductor region 43 and the P + semiconductor region 44 . A conductive material in the contact holes forms a connecting electrode 50 for connecting the N + semiconductor region 43 and the P + semiconductor region 44 to each other. The conductive material also forms a data signal line 49 .
The gate electrode 41 a , the gate insulating film 42 , and the semiconductor films 44 and 45 form the N-channel type TFT transistor. On the other hand, the gate electrode 41 b , the gate insulating film 42 , and the semiconductor films 44 and 46 form a P-channel type transistor. A capacitance of the P-channel type transistor is used as the auxiliary capacitance.
The schematic sectional view of the structure shown above corresponds to the structure shown in FIG. 10B . The structure shown above may correspond to that of FIG. 16 .
Also, the pixel transistor may have an N-channel or a P-channel.
FIGS. 20A and 20B illustrate a method of manufacturing the liquid crystal display device having the top gate structure according to the fourth embodiment. The manufacturing method according to the fourth embodiment is obtained by changing the conventional process shown in FIG. 8C in the conventional manufacturing method shown in FIGS. 8A to 8C and FIGS. 9A and 9B .
Following the process of FIG. 8B , in FIG. 20A , a resist 47 a having such a shape as to cover the LDD region on both sides of the channel region 45 is formed in the TFT transistor region. Then, phosphorus is injected at a high concentration in the vicinity of the TFT transistor to thereby form the N + type semiconductor region 43 and thus metalize the semiconductor layer.
At this time, a resist 47 b is formed so as to prevent the high-concentration injection of phosphorus in the vicinity of the auxiliary capacitance. Thus, as in FIG. 8B , an N − type semiconductor region 44 a is formed around the auxiliary capacitance after the high-concentration injection of phosphorus.
In FIG. 20B , the resist 47 b in the vicinity of the auxiliary capacitance is removed, and boron is injected at a high concentration around the auxiliary capacitance to thereby form a P + type semiconductor region 44 b . At this time, a resist 47 c is formed so as to prevent the high-concentration injection of boron in the vicinity of the TFT transistor.
Thereafter heat treatment is performed as required to activate doped elements.
The fourth embodiment has the same effects as the first and second embodiments.
While the present invention has been described above on the basis of the preferred embodiments, the present invention is not limited to the embodiments described above and is susceptible of various modifications without departing from the spirit of the present invention.
While the foregoing embodiments have been described by taking a liquid crystal display device as an example, the present invention is applicable to other display devices having a similar driving method.
The present invention is not limited to the details of the above described preferred embodiments. The scope of the invention is defined by the appended claims and all changes and modifications as fall within the equivalence of the scope of the claims are therefore to be embraced by the invention.
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Disclosed herein is a display device, including a display element, a first scanning line, a second scanning line, a data signal line, a switching element having a first terminal and a second terminal of a first conduction type, the first terminal being connected to the data signal line, for being held in a conducting state or a non-conducting state according to a voltage applied to the first scanning line, and a storage capacitance having a first electrode and a second electrode that shares the second scanning line, wherein the second terminal of the switching element is connected to the display element and connected to the first electrode of the storage capacitance including a semiconductor film of a second conduction type different from the second terminal.
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FIELD OF THE INVENTION
The present invention relates to improving the coupling efficiency of elliptical light beams to circular optical waveguides and specifically to an optical coupling system comprising a concave cylindrical microlens on the end facet of an optical fiber in conjunction with bulk optic lenses, and to a method of fabrication of the concave cylindrical microlens.
BACKGROUND OF THE INVENTION
Efficient coupling between a laser diode source and an optical fiber is essential for optimal performance in optical communication, laser surgery and fiber optic sensing devices. Two techniques to launch the light from semiconductor diode lasers into optical fiber have been documented extensively in the literature: butt coupling, in which the optical fiber is brought in direct physical contact with the laser diode, and lensing, in which one or more lenses are used to collimate and focus the laser light into the fiber. Because the core diameter of a single-mode fiber is small (5-10 μmn) and the numerical aperture is low (typ. 0.14), and the laser diode has a large beam divergence angle (30°) perpendicular to the junction plane, a high coupling efficiency between laser and fibre cannot be obtained by a butt joint. Further, the alignment tolerance of the laser relative to the fibre axis is as small as 1 μm in this configuration and difficult to control in a production environment.
Lensing systems provide significantly improved coupling as the beam parameters of the laser diode may be modified to better match those of the optical fibre. In a production environment, stable coupling efficiencies of 65% are typical for an optimized pair of high quality bulk optic aspheric lenses. The main cause for the 2 dB loss in coupling is due to the mismatch in modal profiles between the elliptical beam of the laser diode and the symmetrical circular profile of the optical fibre. To address this issue a third, cylindrical lens is often introduced between the two aspheres. The increase in alignment complexity and mechanical tolerancing associated with this solution, however, prove to be uneconomical. A lens system design which corrects the modal mismatch between an elliptical light beam and the circular waveguide structure of an optical fibre is required if substantial improvements in coupling efficiency from single lateral mode diode lasers into single-mode fibres is to be realised.
SUMMARY OF THE INVENTION
The present invention significantly improves the coupling efficiency of lensed systems for elliptical light beams into circular waveguides. The preferred embodiment of the invention relates to the coupling efficiency between laser diodes and optical fibre but the principles thereof are equally applicable to any elliptical beam and circular waveguide. In the preferred embodiment, a pair of bulk optic, rotationally symmetric, asphere lenses is supplemented by a third, concave, cylindrical microlens fabricated on the end facet of the optical fibre. The microlens is designed to correct the more highly divergent, or fast axis of the elliptical beam typically emitted by laser diodes. The difference in the divergence angle of the diode laser beam perpendicular (θ.sub.⊥) and parallel (θ.sub.∥) to the junction plane is known as the aspect ratio of the beam and it is this ratio which dictates the optimum radius of curvature of the microlens. The purpose of the cylindrical microlens is circularise the focussed beam. The microlens collimates the fast axis of the laser beam at the point in the focal plane of the focussing asphere where the beam diameters of the fast (θ.sub.⊥) and slow (θ.sub.∥) axes are matched. In effect, the elliptical beam is circularised upon entry into the optical fibre. The mode profiles of the light beam and the fibre waveguide are much better matched as a result, and the coupling efficiency into the optical fibre is substantially improved.
More particularly, the invention is an optical coupling system comprising a light source, a lens system and a circularly symmetric optical waveguide which has an end facet. The light source emits a substantially elliptical beam having a major and a minor axes. The light beam is more highly divergent in a first plane perpendicular to the major axis than in a second plane parallel to the major axis. The lens system comprises at least one rotationally symmetric bulk optic lens. A concave cylindrical microlens is fabricated on the end facet of the waveguide.
In another aspect, the invention is an optical coupling system as described in the previous paragraph wherein the elliptical light source is a laser diode emitting in a single elliptical spatial mode. The lens system comprises two rotationally symmetric bulk optic asphere lenses. The concave cylindrical microlens has a spherical radius of curvature and the waveguide is an optical fibre which is single mode at the emission wavelength of the laser diode.
The method of fabricating the concave cylindrical microlens according to the invention comprises moving a fine wire in contact with and relative to the end facet, whereby friction between the wire and the end facet creates a concave, cylindrical groove in said end facet.
DESCRIPTION OF DRAWINGS
The invention will be more fully appreciated by reference to the following detailed description and to the accompanying drawings, in which:
FIG. 1 is a perspective view of a preferred embodiment of the cylindrical microlens according to the invention;
FIG. 2A is an optical ray traced diagram for a laser diode emitting through a pair of bulk optic rotationally symmetric lenses;
FIG. 2B illustrates the layout of a laser diode, a pair of bulk optic lenses and an optical fibre including a cylindrical microlens and the effect of the microlens on the optical rays coupled into the fibre; and,
FIG. 3 is a side view of apparatus for fabricating a concave cylindrical microlens according to the invention.
DETAILED DESCRIPTION
A preferred embodiment of the optical fibre used in the invention is depicted in FIG. 1 wherein a concave, cylindrical microlens 10 is polished directly into the end facet of an optical fibre 20. The microlens is centered about the core 30 of the fibre. The optical fibre 20 is provided as part of an optical coupling system or assembly which also includes a laser diode 40 and two asphere rotationally symmetric bulk optic lenses 50 and 60, illustrated in FIG. 2b.
The optimum radius of curvature of the cylindrical lens is dictated by the aspect ratio of the elliptical light beam such as, for example, the beam emitted by a laser diode 40 (illustrated in FIG. 2a), as well as discussed below. The theoretical derivation of the coupling efficiency which follows is based upon a single-frequency laser diode emitting in an elliptical single spatial mode and exhibiting very little astigmatism. The optical waveguide is that of a standard telcom fibre with a step-index profile. Losses due to Fresnel reflection and angular or transversal misalignment of any of the components are neglected.
The laser beam emitted from the facet of the diode 40 is substantially elliptical with a major axis and a minor axis. The beam has a Gaussian intensity profile with spot sizes ω.sub.∥ and ω.sub.⊥, parallel and perpendicular to the junction plane, respectively, as shown in FIG. 2a. These spot sizes are the beam waist radii (1/e 2 ) and ω.sub.∥ ≠ω.sub.⊥. The ratio ω.sub.∥ /ω.sub.⊥ is known as the aspect ratio and typically ranges from 1.2:1 to 10:1 for state of the art laser diodes. The elliptical beam emitted by the laser diode is more highly divergent in the plane perpendicular to the major axis of the ellipse (i.e., the "fast" axis) than in the plane parallel to the major axis (the "slow" axis).
A pair of rotationally symmetric bulk optic lenses with focal lengths f 1 and f 2 , collimate (50) and then focus (60) the laser beam at some point z with transformed spot sizes ω.sub.∥ ' and ω.sub.⊥ ' and ω.sub.∥ '≠ω.sub.⊥ '. The ray traces and beam waists of both the slow and fast axes of the laser diode, ω.sub.∥ and ω.sub.⊥ respectively, are superimposed in the plane of the page in FIG. 2a and depicted in exaggerated scale for clarity. In FIG. 2b the effect of the concave cylindrical microlens is illustrated, wherein the fast axis of the laser beam is incident upon the microlens at an axial distance z from the focal plane of the second bulk optic asphere lens. At this position z the beam diameter of the fast axis, 2ω.sub.⊥ " and the beam diameter of the slow axis, 2ω.sub.∥ ', match the mode diameter of the optical fibre, 2ω 0 .
The laser beam is coupled into a step-index optical fibre, defined as single-mode at the laser wavelength. The power distribution in a step-index single-mode fibre can be approximated by a Gaussian beam if the normalised frequency V of the fibre is in the range 1.9≦V≦2.4 where V is given by ##EQU1## where λ is the wavelength of the optical power, n 1 and n 2 are the indices of the core and cladding, respectively, and a is the radius of the fibre core. The fibre mode radius ω 0 of such a fibre is given by ##EQU2## If we position the fibre at the waist of the focussed laser beam, then the power coupling efficiency η between the elliptical laser beam and the fundamental mode of the optical fibre is ##EQU3##
The same formula holds for η.sub.⊥, if the subscript `∥` is replaced by `⊥` in the last equation. The coupling efficiency depends upon the degree of overlap between the waist radii of the focussed laser beam and the fibre mode. To maximize η, we match the focussed beam waist of the slow axis to the fibre mode, ω.sub.∥ '=ω 0 , by choosing an appropriate pair of lenses and then create a nonsymmetric transformation upon the fast axis, ω.sub.⊥ ', such that ω.sub.⊥ "=ω.sub.∥ '=ω 0 . This is achieved with the cylindrical microlens. The radius of curvature of the cylindrical microlens is chosen to null the wavefront curvature of the beam at the point where ω.sub.⊥ "=ω 0 .
The propagation of the focussed gaussian laser beam is described by ##EQU4## To optimise the coupling efficiency the mode fields must match, and so we impose the constraint that ω.sub.⊥ "=ω 0 and solve for z. R(z), the radius of curvature of the beam wavefront at this point can then be calculated from ##EQU5## If the focal length of the microlens is exactly matched, but opposite in sign, to the curvature of the optical beam, the curvature of the beam wavefront is nulled and thus matched to the wavefront of the fibre mode, which is planar, by definition, at the end facet of the fibre.
Classically, for a spherical lens, the radius of curvature and the focal length are related by ##EQU6## where R L is the radius of curvature of the microlens and n is the refractive index of the lens material. Optimum coupling will occur when the centre of curvature of the wavefront lies at the focal point of the lens, and we can thus calculate the optimum radius of curvature for the microlens. The optimum radius of curvature of the microlens is therefore given by: ##EQU7## Effective radii of curvature of the microlens according to the invention are between 5 and 50 μm.
This method of improving the coupling efficiency is applicable to any fibre optic devices which require high coupling efficiency of an elliptical laser beam into optical fibre such as fibre lasers and fibre amplifiers. As an example, light from a 150 mW, single spatial mode diode laser was launched into standard telcom fibre, single mode at the laser wavelength. The aspect ratio of the emitting region of the laser diode was 2.2:1, and the radius of curvature of the microlens was 9 μm. 130 mW of light was captured by the fibre for a coupling efficiency of 87% (ex-facet). This constituted an increase in coupling of 20% relative to a traditional lensing system in which no correction for beam elipticity was provided.
Method of Fabrication
In the preferred embodiment, the cylindrical concave 10 microlens is polished directly into the polished or cleaved end facet of the optical fibre 20. The microlens is created by polishing the fibre facet with an extremely fine, high tensile strength wire which may vary in diameter from 10 μm to 100 μm with the apparatus illustrated schematically in FIG. 3. In the preferred method of fabrication, the optical fibre 20 is fixed in a ceramic ferrule 140 such that the facet to be polished extends beyond the ferrule by approximately 500 μm. The ferrule is then mounted on a precision 3-axis translator 150. The wire 100 is spooled onto a drum 110 which is mounted onto a precision spindle 115. The wire is drawn through a series of guide pins 120 into which microgrooves have been machined to eliminate lateral motion of the wire during the polishing sequence. Tension is applied to the wire by fixing a free hanging weight 130 to one end of the wire; this ensures a positive, loaded contact through the grooves on the guide pins.
The core of the fibre is carefully centered with respect to the wire (±2 μm tolerance). This alignment is verified visually with the aid of a stereoscope 160. As the wire is dragged across the end facet of the fibre, a cylindrical groove is created in the fibre with a radius of curvature equal to that of the wire. This cylindrical, spherical groove acts as a cylindrical microlens with a focal length equal to the diameter of the wire.
In an exemplary embodiment, a hard temper tungsten wire with a diameter of 50 μm was spooled onto a 2 cm drum on a precision spindle, aligned in the grooves on the guide pins, and tensioned with a 20-gram mass. A bi-directional translation of the wire parallel to its longitudinal axis, of 10 cm, repeated 75 times, produced a cylindrical groove in the end facet of the optical fibre (Corning 1060), typically 20-30 μm in width and 3-5 μm in depth. The translation of the wire is not limited to this translation sequence and those knowledgeable in the art will appreciate that any relative motion between the wire and the fibre, such as for example, bi-directional, axial, sonic, or spinning, or a combination thereof, which creates a concave cylindrical groove in the end facet of the fibre is within the spirit of the invention.
The translation of the wire may be automated. Polishing compounds may be used during the polishing sequence. The optical quality of the surface finish of the polished cylindrical microlens may be improved by flash heating the fibre end facet in the arc of an optical fusion splicer. The end facet of the fibre may be anti-reflection (AR) coated.
The concave cylindrical microlens may also be created in other ways. One method is to stamp or emboss the end facet of the fibre with a tool in which a convex ridge with an appropriate radius of curvature has been machined. The fibre tip is then heated to just below the softening temperature of silica and the embossing tool is heated to a temperature approximately 100°-200° C. above this. Another method may involve preferential chemical etching of the fibre end facet in a pattern outlined by a mask. Yet another method may involve melting the fibre end facet with an extremely hot wire of the appropriate diameter.
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An optical coupling system for improving the coupling efficiency of an elliptical light beam into optical fiber comprises a cylindrical concave microlens on the end facet of the optical fiber in conjunction with a pair of bulk optic asphere lenses. A method of producing a cylindrical concave microlens according to the invention consists of translating a fine wire across the end facet of an optical fiber so as to create a cylindrical grove.
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BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to improvements in telescopic gun sights and, more particularly, to an improved windage correction system for a telescopic gun sight which includes a generally horizontal windage correction scale operative to provide instant windage correction target alignment and including instant windage correction target alignment values positioned at point-specific spaced-apart locations on the generally horizontal scale with specific instant windage correction target alignment values corresponding to selected distance amounts calculated for a selected bullet type and weight.
2. Description of the Prior Art
Present telescopic sites used on rifles and other firearms, generally comprise a cross-hair reticule positioned within the scope for referencing the hunter's vision with respect to a target. A hunter “sights in” or “zeros” the scope by firing bullets in a trial-by-error method and repetitively adjusts the reticule in the scope until the center of the cross-hair of the reticule aligns with the impact position of the bullet on the target. Such a method of zeroing a rifle requires considerable time and the costly firing of bullets.
U.S. Pat. No. 2,094,623 issued to F. E. Stokey in 1937, discloses a telescopic sight in which two reticules are utilized to enable the rifle to be zeroed in with a single shot. The Stokey device, however, was quite expensive and complicated. Also, because the hunter always views two reticules within his field of vision through the scope, it was quite possible that the hunter would inadvertently sight on the incorrect reticle. Also, the reticule which was sited in on target, could be off center from the field of vision through the scope causing further confusion and irritation to the hunter. Further, the hunter was shooting upside down with the Stokey scope, because the image through the scope was inverted due to the use of an objective and an ocular lens.
While the Stokey scope of 1937 suggested one-shot sighting, the inherent disadvantages, expense and complication of the system voided its general use. Since 1937, the prior art has suggested the use of an inverting tube to erect the object to be viewed through the scope by the hunter thus, eliminating upside down shooting by the hunter. The use of an inverting tube further establishes the center of the cross-hair wires at the center of the scope's field of vision despite adjustment of the cross-hair reticule relative to the image being viewed. The advent of the inverting tube was thus well received by the hunter.
When using an inverting tube within a scope, the reticule is positioned at the eye piece end of the tube. This is because the positioning of the reticule at the object end of the inverting tube causes the magnification of the cross-hairs of the reticule at high powers of the scope, particularly where the scope has zoom capabilities for changing the object's magnification. Such magnification of the cross-hair wires is annoying to the hunter, blocking portions of his view. Thus, present day scope manufacturers utilize an inverting tube with cross hair wires positioned at the eye piece end of the inverting tube.
Besides the problem of multiple firings to sight-in present day scopes, a problem of parallax exists when using the scope to shoot at close range. Parallax is caused by the cross-hair wires lying outside the image plane in conjunction with the hunter varying the position of his eye relative to the scope as he does not each time look across the cross-hairs at the same visual angle.
Further problems with such conventional scopes include the addition of devices which serve to approximate range and determine the “hold over” or aiming point in view of the range of the target. Particularly, the rifleman must judge the distance of the object and then compensate for the drop of the bullet in view of the weight and velocity of the bullet. Thus, the hunter must point the scope above the target in order for the bullet to drop onto the target. All of these range finding devices, however, add clutter to the hunter's field of vision and are particularly annoying when the hunter is shooting at close range and thus not using the range finding devices.
Such range finding devices include, for example, the use of a transparent reticule disc at one end of an inverter tube, which bears separate circles for denoting range and drop of the bullet, see for example U.S. Pat. No. 3,392,450 issued to G. L. Herter et al. on Jul. 16, 1968 or Shepherd, U.S. Pat. No. 4,403,421, issued on Sep. 13, 1983. Other such range defining devices include stadia lines which take the form of two parallely disposed horizontal lines positioned across the field of view of the hunter for his use to determine whether the object fits within the lines in order to gauge distance of a targeted object. However, despite the various types of range finding indicia used with scopes of the prior art, there has been precious little development or improvement in the methods and devices available to hunters and shooters to correct for wind, and as wind correction is at least as critical to a successful shot as finding the range to the target, there is a need for significant improvement in this area.
There are several simple formulas available to calculate the deflection due to a crosswind. One which is used in the art is as follows: z=w*(t−X/v 0 ) where z is the deflection, w is the wind speed, t is the flight time of the bullet to the target, x is the distance to target and v 0 is the muzzle velocity. This formula is most commonly used with metric units, with velocities in meters per second, time in seconds and distances in meters. The only unknown parameter in the above formula is the bullet flight time (which generally may be found in manufacturers' tables).
Another widely used formula is the United States Marine Corps formula, which is used as follows: After determining wind direction and speed, the following formula is applied: Range in 100 Yds.×Speed in MPH/15 (math constant)=MOA Windage. For instance, if your target is 300 yards away, and there's a 10 MPH wind, you would plug the numbers into the formula like this: 3×10=30/15=2 MOA. Click-in the two minutes of angle into the scope in the direction of the wind and aim dead-on. It should be noted, however, that one additional concern with the Marine formula is that it is only accurate at 500 yards or less. With a target that is farther away, the mathematical constant must change, as shown here: 600 Yards: Divide by 14, 700 Yards: Divide by 13, 800 Yards: Divide by 13, 900 Yards: Divide by 12 and 1,000 Yards: Divide by 11.
To perform all these calculations immediately prior to taking the shot is a difficult task to say the least, and therefore there is a need to improve and streamline the task of determining appropriate windage corrections. It is, therefore, an object of the present invention to provide an improved telescopic sight which adds the advantages of the prior art without their attending disadvantages.
It is yet another object of the invention to provide a telescopic sight which includes an easily used windage correction system and method by which windage corrections for shots may be quickly and accurately determined.
It is yet another object of the present invention to provide a telescopic sight for use with a firearm which includes a secondary reticule having a windage correction scale imprinted thereon which is removed from the field of view in the scope when the magnification of the scope approaches its maximum magnification setting.
It is yet another object of the present invention to provide a telescopic sight having a generally horizontal windage correction scale imprinted on either the primary or secondary reticule, the scale operative to provide instant windage correction target alignment and including instant windage correction target alignment values positioned at point-specific spaced-apart locations on the generally horizontal scale with specific instant windage correction target alignment values corresponding to selected distance amounts calculated for a selected bullet type and weight.
It is yet another object of the present invention to provide a telescopic gun sight with a windage correction scale which requires only minimal computation prior to use, and will not substantially slow or retard the aiming and shooting process.
Finally, an object of the present invention is to provide an improved telescopic sight having a windage correction scale which is relatively simple and durable in construction and is safe, efficient and effective in use.
SUMMARY OF THE INVENTION
The present invention provides a windage correction system for a telescopic gun sight which includes a telescopic gun sight at least including an adjustable lens configuration for adjustably magnifying an external object to form an object image, an inverting tube for inverting the object image, an ocular lens array for presenting the object image for viewing, a primary reticule positioned generally adjacent the ocular lens array rearwards of the inverting tube and including sighting insignia imprinted thereon and a secondary reticule being movable both horizontally and vertically in the image plane independent of the inverting tube and positioned forward of the adjustable lens configuration. The secondary reticule further includes a generally horizontal windage correction scale operative to provide instant windage correction target alignment. It includes instant windage correction target alignment values positioned at point-specific spaced-apart locations on the generally horizontal scale with specific instant windage correction target alignment values corresponding to selected distance amounts calculated for a selected bullet type and weight.
The present invention as thus described provides substantial advantages over those windage correction devices and systems found in the prior art. For example, the windage scale allows a user to quickly and accurately determine the appropriate windage correction value which should be used for the shot. Moreover, this is done without requiring the user to undertake extensive calculations to determine the appropriate windage correction, as the present scale generally eliminates the necessity for such calculations. Finally, although minute of angle windage correction scales have been used for a long time in connection with telescopic gun sights, use of such MOA scales still require substantial calculations to enable them to be used for windage correction, whereas the present invention requires almost no detailed calculations prior to use of the scale. It is therefore seen that the present invention provides a substantial improvement over those methods, systems and devices found in the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the improved telescopic gun sight of the present invention;
FIG. 2 is a detailed view of the view through the scope showing the indicia imprinted on the primary and secondary reticules;
FIG. 3 is a detailed view of the view through the scope at a higher magnification power showing how the indicia are shifted out of the line of sight of fire of the rifle as the magnification is increased;
FIGS. 4 , 5 and 6 are detailed scope views showing usage of the scope during windage correction; and
FIGS. 7 , 8 and 9 are detailed scope views showing the windage correction scale of the present invention being used for windage correction.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 , the improved telescopic gun sight 10 is shown as including a pair of reticule adjustment knobs 40 and 42 disposed along the outside of the tubular housing 12 of the scope 10 , for permitting the hunter to selectively adjust the effective position of a pair of sighting reticules disposed within the scope 10 , in order to properly sight-in the rifle and correct for bullet drop and any crosswind.
The scope includes an eyepiece end 14 comprising an ocular lens system 20 through which the hunter views during siting of a target upon which he wishes to fire. The other end of the scope is the objective end 16 and includes an objective lens 22 which is directed toward the object to be viewed. The light rays coming from the object pass through objective lens 22 and converge to form an image on an image plane within the tubular housing and generally defined by reference numeral 26 . Because the image appearing in the image plane will be the inverted image of the viewed object, an inverter tube 28 is disposed between the image plane 26 and the ocular lens 20 for erecting the image for upright presentation as a second intermediate image in a second image plane generally defined by reference numeral 30 . The second image plane lies at the focus of the ocular lens 20 for presenting the erected image to the eye of the hunter, as understood.
The inverter tube 28 includes standard erecting lenses positioned in a conventional fashion for erecting the image received by the inverting tube 28 , with the erecting lenses being adjustably mounted relative to one another and are movable via rotational movement of adjustment ring 36 . As the adjustment ring 36 is rotated, the erecting lenses are moved in a predetermined relationship in order to vary the magnification of the object image appearing in image plane 30 , as understood.
A primary reticule 44 comprising a pair of cross-hair wires is fixed with respect to housing 12 at the ocular end of inverter tube 28 . The cross-hair wires of reticule 44 serve as reference lines for siting the weapon by the hunter, and the primary reticle 44 functions as per standard siting reticles currently used in the prior art.
The inverter tube 28 is secured in a substantially fixed relationship with respect to housing 12 at the ocular end of the inverting tube, while the objective end of the inverting tube is movable relative to the walls of tubular housing 12 . The inverting tube 28 may be adjusted by any appropriate adjusting device, and such adjustment devices are understood by those skilled in the art of telescopic gun sights. Movement of the objective end of the inverting tube 28 serves to position primary reticule 44 relative to the image plane 26 for positioning the image with respect to the primary reticule as viewed by the hunter. Such inverter tubes have been used previously in scope sights; see for example U.S. Pat. No. 2,995,512 issued to Kollmorgen et al on Oct. 11, 1960.
The use of the inverting tube permits the primary reticule 44 to have the center of the cross-hair wires always in the center of the field of vision of the hunter through scope 10 . This is most preferable to the hunter and avoids any confusion caused by the cross hairs being positioned off-centered due to adjustment by the hunter to indicate the center of the scope with respect to the gun barrel. Thus, the line of site of scope 10 is along an optical axis which passes through the eye piece lens system, the inverting tube and the objective lens, and has the center of the cross-hair reticule at the center of the field of vision of the hunter.
A secondary reticule 48 is positionable in image plane 26 for movement therewithin independently of the movement of inverter tube 28 . As shown in more detail in FIGS. 2 and 3 , secondary reticule 48 is adjustably mounted within the tubular housing 12 such that the secondary reticule depends from a mounting structure into the image plane 26 . Reticule adjustment knobs 40 and 42 control the movement of secondary reticule 48 in the horizontal and vertical planes, and in the preferred embodiment, the reticule adjustment knobs 40 and 42 are designed to adjust the position of the secondary reticule 48 through a “click” type of adjustment where each rotational “click” of the reticule adjustment knobs 40 and 42 equates to an adjustment of ¼ MOA (minutes of angle). Of course, it may be preferable to utilize a different adjustment system, but it has been found that the well-known and currently available “click” adjustment system works perfectly well with the present invention and therefore its use herewith is preferred.
At this point, the invention is similar to at least one prior art gunsight, specifically Shepherd, U.S. Pat. No. 4,403,421. However, the significant inventive aspects of the present invention will now be exposed, particularly as they relate to indicia inscribed on or formed on the secondary reticule 48 which, as was discussed previously, would preferably be a generally circular glass or transparent plastic plate. Specifically, the indicia imprinted on the secondary reticule 48 is an improved windage scale 70 which is operative to provide instant windage correction target alignment for a user of the improved telescopic gunsight 10 of the present invention without requiring significant mathematical equation solving as is currently required by windage correction systems and methods found in the prior art.
As was discussed previously, one of the most common wind correction methods currently used in the United States Marine Corps windage correction formula which requires the shooter to determine the range in one hundred yard increments from the shooter and then multiply that number by the wind speed in miles per hour, and then divide the resulting figure by fifteen, which serves as the math constant, to determine the minutes of angle which should be used to correct for the wind value. While this formula is not exceedingly difficult to apply, it has several significant drawbacks, the first being that even after the entire formula is computed, the user must then “click in” the resulting minutes of angle into the scope in order to correct for the wind, and the shooter must be sure that the clicks have been applied in the correct direction, namely in the direction of the wind. Furthermore, the USMC formula is only accurate at five hundred yards or less and, when the target is farther away, the mathematical constant must be changed, as was described previously. The shooter must be aware of all of these variations and calculations, compute all of them to a sufficient degree of accuracy, apply the resulting minutes of angle to the scope, ensure that the scope is being adjusted in the correct direction, and then and only then may he or she commence with the shot. In field operations, the maximum amount of time permitted by armed forces regulations to complete the computations and correctly adjust the scope for range and windage is four minutes, and it is clear that in that time period, many other events may have occurred, and in fact the opportunity to take the shot may have been lost forever.
The improved windage scale 70 of the present invention seeks to avoid all of those computations by providing a simple to use and direct windage correction scale which does not require the user to undertake significant mathematical operations to determine the correct windage adjustment. In the present invention, the improved windage scale 70 would include instant windage correction target alignment values 72 which would be printed above the standard minutes of angle scale 66 , as shown best in FIGS. 2 and 3 . In the preferred embodiment, the instant windage correction target alignment values 72 would consist of a series of integer values beginning with the number three and proceeding up to the number ten, with each numerical integer value being associated with a point-specific location signified by a dot 74 , with one set of instant windage correction target alignment values 72 positioned on each side of the secondary reticule 48 to provide correction for winds blowing from either direction across the shooter's line of fire. As each of the instant windage correction target alignment values 72 are identical, the following description of the left set should be understood to apply equally to the right set of values.
The positions of the dots 74 are determined by selecting corresponding distance amounts to correspond with the integer values positioned above the dot 74 . In the preferred embodiment, the integer values would correspond with the hundred yard range of the shot to be taken, with the first integer value being three thus corresponding to three hundred yards and the last integer value being ten and corresponding to the thousand yard windage correction location. Each of the dots 74 are positioned at the correct minutes of angle locations to indicate where a fifty-five gram HORNADY®, VMAX bullet propelled at a muzzle velocity of 3240 FPS would be pushed by a full value ten mile per hour wind blowing directly from left to right across the shooter's line of fire. To clarify, a full value wind is from the nine o'clock or three o'clock direction which corresponds to a ninety degree angle from the shooter's line of fire toward the target, which is always considered twelve o'clock. A wind from a direction of one-thirty, four-thirty, seven-thirty, or ten-thirty would be a half value wind, which would move the bullet off course approximately half as much as the same wind would if it were a full value. Likewise, a one-third value wind will move it one-third of the amount and a two-thirds value wind will push it two-thirds and so on and so forth. Winds blowing directly towards or directly away from the shooter have no crosswind value and correction for these types of winds is not necessary using the improved windage scale 70 of the present invention.
Returning to the improved windage scale 70 of the present invention, it should be noted that the ten mile per hour figure used to design the improved windage scale 70 is a very versatile choice in that it is easy to convert this scale to other wind speeds regardless of the value of those wind speeds. For example, if the shooter were to encounter a five mile per hour wind, the improved windage scale 70 would be used with half the values in the scale, and likewise for a fifteen mile per hour wind, a shooter would use one point five times the value shown on the scale. The main problem in correctly determining the appropriate wind correction factor, however, is to obtain an accurate determination of the speed and direction of the wind, and therefore it is generally recommended to use a portable, hand-held anemometer to make such determinations. However, the benefit of the present invention is that once the wind speed and direction are determined, the user of the present invention will need to make only minor calculations and adjustments to properly institute the windage correction using the improved telescopic gunsight 10 of the present invention.
For example, say the user determines that a twenty mile per hour wind was blowing from the one-thirty direction during preparation for the shot. As was discussed previously, the one-thirty wind would be a half value wind and when multiplied by the twenty mile per hour wind speed, the resulting affecting speed of the wind is ten miles per hour. This is exactly the scale at which the improved windage scale 70 of the present invention is set, and so once the shooter has determined the distance of the shot, for example four hundred fifty yards. as shown in FIG. 7 , he or she would then “click in” the adjustment by rotating reticule adjustment knob 40 to move the windage scale 70 to the right until the windage adjustment line 76 is positioned in alignment with the dot 74 corresponding to the value halfway between the four and five on the improved windage scale 72 . The shooter would then merely line up the cross hairs on the target and take the shot when ready knowing that the appropriate correction for windage has already been programmed into the improved telescopic gunsight 10 of the present invention. The same procedure may be used with any wind direction and wind speed, such as the five mile per hour wind as shown in FIG. 8 , and the need to determine the minutes of angle which need to be set in the scope is eliminated by the improved windage scale 70 of the present invention.
It is also a relatively simple matter to prepare an alternative windage scale by using a different bullet as the basis for the windage correction target alignment values 72 to be inserted into the improved windage scale 70 of the present invention. This would involve repositioning of the dots 74 once those computations had been completed, but once the dots 74 are positioned in correct association with the instant windage correction target alignment values 72 as reprogrammed and redetermined in connection with a newly-selected bullet type and weight, the user of the improved telescopic gunsight 10 of the present invention may undertake the same quick and simple to perform steps described previously which are now used with the newly-selected bullet type and weight.
One of the true benefits of the improved windage scale 70 of the present invention is shown best in FIGS. 2 and 3 in that as the magnification of the target is increased, the viewing field of the gunsight correspondingly grows smaller. Because the improved windage scale 70 is positioned on the secondary reticule 48 , this means that as the power of the scope is increased by rotation of the ring 43 , the improved windage scale 70 is slowly removed from the field of view, as shown in FIG. 3 , and as the magnification of the scope increases towards maximum power, the improved windage scale 70 is no longer visible nor viewable through the improved telescopic gunsight 10 . It should be noted that the improved windage scale 70 is of course still imprinted on the secondary reticule 48 but since the viewing field has decreased as the magnification of the scope has been increased, the portion of the secondary reticule 48 which is viewable through the scope no longer includes the improved windage scale 70 , and thus the viewing field of the scope is less cluttered which will likely improve the usability of the gunsight 10 with the improved visual field available to the shooter.
Of course, it is not strictly necessary to position the improved windage scale 70 on the secondary reticule 48 in such a manner as to preclude viewing of the improved windage scale 70 as the scope approaches maximum power, but it has been found that the less cluttered the view field of the scope, the greater chance that the shooter will not be distracted in attempting to hit the target. It is only because the improved windage scale 70 is imprinted on the secondary reticule 48 that the above-described feature is even available, and the combination of the features of the improved windage scale 70 as described previously with the removal of the improved windage scale 70 from the viewing field at maximum power renders the present invention a substantial improvement over those windage correction systems and methods found in the prior art.
It is to be understood that numerous additions, substitutions and modifications may be made to the improved telescopic gunsight 10 and improved windage scale 70 of the present invention which fall within the intended broad scope of the appended claims. For example, although the improved windage scale 70 has been described as being imprinted on the secondary reticule 48 , it may be entirely possible to print the improved windage scale 70 on a primary reticule which is found in numerous gun sights and gun scopes presently available in the prior art, and although the loss of the above-describe feature of having the improved windage scale 70 be removed from view at higher magnifications would be lost when the present invention is used in connection with single reticule scope, the instant windage adjustment features previously described will still be available and these are believed to be extremely valuable and deserving of protection regardless of the positioning of the improved windage scale 70 on any particular primary or secondary reticule. Furthermore, although the improved windage scale 70 has been described as being used with particular integer values to represent yardage of the shot, adjustment or modification of the integer or numeric values may be easily done by substituting any particular alphanumeric or symbolic value for the instant windage correction target alignment values 72 used in connection with the positioning dots 74 as described previously. For example, a shooter who consistently shoots at one particular type of target positioned a specific distance away, such as a biathelete or target shooting participant, could place a positioning dot 74 at the appropriate distance and label that particular location with a selected alphanumeric value which has significance to that particular person. Modification and substitution of such alphanumeric values is therefore understood to be a part of this disclosure. Finally, it should be noted that although use of the improved windage scale 70 has been described as including the step of clicking the scope adjustment device to move the secondary reticule 48 to the appropriate alignment with the windage adjustment line 76 , with practice it may be more efficient for the user to simply offset the shot alignment to move the target into line with the appropriate windage correction target alignment value 72 instead of adjusting the secondary reticule 48 , which takes longer to institute, as shown in FIG. 9 . It is expected that with sufficient practice, such offset aiming will likely be as accurate as adjustment of the scope, but it has been found that adjustment of the scope by use of the improved windage scale 70 of the present invention results in the most accurate and most dependable windage adjustment currently available, and therefore it is preferred that each of the steps described previously be performed in sequence to correct for wind by use of the improved windage scale 70 of the present invention.
There has therefore been shown and described an improved telescopic gunsight 10 and improved windage scale 70 which accomplish at least all of their intended objectives.
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An improved telescopic gun sight includes a telescopic gun sight at least including an adjustable lens configuration for adjustably magnifying an external object to form an object image, an inverting tube for inverting the object image, an ocular lens array for presenting the object image for viewing, a primary reticule including sighting insignia imprinted thereon and a secondary reticule being movable both horizontally and vertically in the image plane. The secondary reticule includes a generally horizontal windage correction scale operative to provide instant windage correction target alignment. It includes instant windage correction target alignment values positioned at point-specific spaced-apart locations with specific instant windage correction target alignment values corresponding to selected distance amounts calculated for a selected bullet type and weight.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a piezoelectric ceramic to be used in surface mount type piezoelectric components which must be resistant to heat and a method of manufacturing the same.
2. Description of the Related Art
As piezoelectric ceramics used in ceramic filters and the like, piezoelectric ceramics mainly composed of lead zirconate titanate (PZT or Pb(Ti x Zr 1-x )O 3 ) or the like have been widely used. Materials used for ceramic filters which have excellent characteristics in that group delay time (GDT) characteristics are flat and phase distortion is small, must have a small mechanical factor of merit Qm. In order to improve the piezoelectric characteristics of such ceramics, various additives in very small amounts have been added to them. Known materials include those obtained by adding niobium oxide, antimony oxide, tantalum oxide and the like as additives to lead titanate zirconate and those obtained by substituting rare earth elements such as Sr, Ba, Ca and La for a part of Pb atoms in lead titanate zirconate.
However, piezoelectric ceramics having a small Qm value as described above have had a shortcoming in that even such a ceramic having a high Curie point suffers shifts in resonant and antiresonant frequencies at elevated temperatures because of a decrease in the electromechanical coupling factor K when the electrodes formed on both ends of the piezoelectric ceramic are opened. This has resulted in a problem in that such a ceramic used as a surface mount type filter element suffers reduction in filter characteristics when exposed to a high temperature (about 250° C.) during reflow soldering.
As a solution to this problem, it has been reported that the specific resistance of a grain boundary portion of a piezoelectric ceramic having a small Qm value and a high Curie point can be reduced to improve heat-resisting properties by thermally diffusing a manganese compound from the surface of the piezoelectric ceramic to distribute an oxide of manganese unevenly so that it concentrates in the grain boundary layer in a high density. See, e.g., JP-A-6-1655, JP-A-6-1656 and JP-A-1657.
However, there has been a problem from the viewpoint of manufacture in that the thermal diffusion of the manganese compound from the surface of the piezoelectric ceramic causes a change in the structure of the grain boundary of a piezoelectric ceramic which has been sintered in advance and in that characteristics significantly vary if the amount of Pb in the piezoelectric ceramic fluctuates due to evaporation during manufacturing or if the temperature distribution in the thermal diffusion furnace is great. Therefore, it has been difficult to perform thermal diffusion in a large amount and in a stable manner, which has made the reduction in the specific resistance of a grain boundary portion insufficient to improve heat-resisting properties.
It is therefore an object of the present invention to provide a piezoelectric ceramic in which the above-described problems are solved and which has a small mechanical factor of merit Qm and excellent heat-resisting properties, e.g., a piezoelectric ceramic for filter elements which is compatible with surface mounting and a method for manufacturing the same in a large amount and in a stable manner.
SUMMARY OF THE INVENTION
A copending application (application Ser. No. 08/729,733, filed Oct. 7, 1996; P/1071-213), now U.S. Pat. No. 5,766,502 piezoelectric ceramic including an oxide of lead in the grain boundary layer in addition to an oxide of manganese. The inventors found that to form a glass phase in the grain boundary layer is also effective to improve the characteristics of the piezoelectric ceramic.
According to a first aspect of the present invention, there is provided a piezoelectric ceramic including at least a composite oxide of lead, zirconium and titanium, characterized in that an oxide of manganese exists in a grain boundary layer in a density higher than that in a crystal grain of the piezoelectric ceramic and a glass phase exists in the grain boundary layer.
According to a second aspect of the present invention, there is provided a method of manufacturing a piezoelectric ceramic, characterized in that a manganese compound and a glass material are deposited on the surface of a piezoelectric ceramic including at least a composite oxide of lead, zirconium and titanium, and thermal processing is performed thereafter to diffuse the deposited substances in a grain boundary portion of the piezoelectric ceramic.
Since the oxide of manganese is distributed in the grain boundary layer at a density higher than that in a crystal grain of a piezoelectric ceramic and a glass phase exists in the grain boundary layer, the specific resistance of the piezoelectric ceramic can be reduced to improve heat-resisting properties.
Further, when thermal processing is performed in the method of manufacture of the present invention on a manganese compound and a glass material deposited on the surface of a piezoelectric ceramic, the glass material melts on the surface of the piezoelectric ceramic at the diffusion temperature. This facilitates the migration of the manganese compound to the grain boundary portion of the piezoelectric ceramic, thereby allowing uniform diffusion in a wide temperature range. In addition, even when the amount of Pb in the grain boundary portion of the piezoelectric ceramic is small, the glass material which has melted on the surface allows the diffusion of the manganese compound into the grain boundary to be promoted.
Accordingly, the specific resistance of a PZT type piezoelectric ceramic can be reduced to improve heat-resisting properties, and a manganese compound can be thermally diffused in the piezoelectric ceramic in a large amount and in a stable manner without being affected by variations of the temperature in the diffusion furnace, fluctuations in the amount of Pb in the piezoelectric ceramic, and changes in the grain boundary structure and components of the piezoelectric ceramic.
It is therefore possible to provide a piezoelectric ceramic having a small mechanical factor of merit Qm, a large electromechanical coupling factor K, and excellent heat-resisting properties because of a reduced specific resistance, e.g., a piezoelectric ceramic for filter elements which is compatible with surface mounting and to manufacture it in a stable manner.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph showing changes in specific resistance ρ relative to diffusion temperatures according to a first embodiment of the present invention.
FIG. 2 is a graph showing changes in an electromechanical coupling factor K relative to diffusion temperatures according to the first embodiment of the present invention.
FIG. 3 is a graph showing changes in specific resistance p relative to diffusion temperatures according to a second embodiment of the present invention.
FIG. 4 is a graph showing changes in an electromechanical coupling factor K relative to diffusion temperatures according to the second embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
A first embodiment of the present invention will now be described.
First, a piezoelectric ceramic was produced by depositing a manganese compound and a glass material on the surface of a piezoelectric ceramic composition and by performing thermal processing to diffuse the deposited substance into a grain boundary portion.
Specifically, as starting materials, powders of PbO, SrO, La 2 O 3 , TiO 2 and ZrO 2 were prepared which are materials that constitute a piezoelectric ceramic having a small mechanical factor of merit Qm. Those powders were weighed to obtain a ceramic represented by (Pb 0 .95 Sr 0 .03 La 0 .02) (Zr 0 .51 Ti 0 .49)O 3 which was mixed with water and subjected to dry type mixing using a ball mill.
The resultant mixture was dried and then calcinated for two hours at a temperature in the range from 800 to 900° C. The calcinated material was mixed with a small amount of polyvinyl alcohol and water and was subjected to press molding at a pressure of 1000 Kg/cm 2 . The resultant molded element was burned for two hours at a temperature in the range from 1100 to 1250° C. to obtain a ceramic in the form of a rectangular plate having a size of 20×30 mm and a thickness of 1 mm.
Meanwhile, MnCO 3 powder and borosilicate lead glass were weighed to obtain respective predetermined amounts which satisfy weight ratios of 3:7 and 5:5 and were mixed with varnish to produce two types of paste for thermal diffusion.
Next, the two types of paste were applied to the surface of separate ceramics as described above by means of screen printing. After drying, thermal processing was performed for two hours at a temperature in the range from 750 to 1100° C. to diffuse the manganese compound. These ceramics were then polished to a thickness in the range from 0.3 to 0.8 mm. Silver electrodes were applied to both end faces of the ceramics and baked. Thereafter, a polarization process was performed by applying an electric field in the range from 2 to 3 kV/mm for 30 minutes in insulating oil (temperature was in the range from the room temperature to 100° C.) to obtain piezoelectric ceramics.
The resultant piezoelectric ceramics were cut into a form of a square plate of 5×5 mm and the specific resistance ρ and the electromechanical coupling factor K at spreading vibration were measured.
A second embodiment of the present invention will now be described.
A piezoelectric ceramic was produced by depositing a mixture obtained by performing thermal processing on a manganese compound and lead type glass on the surface of a piezoelectric ceramic composition and by performing thermal processing to diffuse the deposited substance into a grain boundary portion.
Specifically, a ceramic in the form of a rectangular plate having a size of 20×30 mm and a thickness of 1 mm was first prepared in the same manner as in the first embodiment.
Meanwhile, a glass including manganese mixture was obtained by weighing MnCO 3 and lead type glass, melting them by means of thermal processing in a crucible, and quenching them. The mixture was combined with varnish in the same manner as in the above-described first embodiment to obtain a paste for thermal diffusion. It is not essential that the mixture obtained after quenching is uniformly amorphous and, for example, it may include the manganese compound and manganese silicate or the like, i.e., a silicon compound which is a component of the glass material.
Next, the paste for thermal diffusion of manganese thus produced was applied to the surface of the ceramic by means of screen printing, and a piezoelectric ceramic was obtained thereafter in the same manner as in the first embodiment.
The resultant piezoelectric ceramic was cut into a form of square plate of 5×5 mm and the specific resistance ρ and the electromechanical coupling factor K were measured.
An example for comparison will now be described.
A piezoelectric ceramic was produced by depositing a manganese compound on the surface of a piezoelectric ceramic composition without the glass and by performing thermal processing to diffuse the deposited substance into a grain boundary portion.
Specifically, a ceramic in the form of a rectangular plate having a size of 20×30 mm and a thickness of 1 mm was first prepared in the same manner as in the first embodiment.
Meanwhile, paste was produced by mixing only the MnCO 3 with varnish. Next, this paste was applied to the surface of the ceramic by means of screen printing, and a piezoelectric ceramic was obtained thereafter in the same manner as in the first embodiment.
The resultant piezoelectric ceramic was cut into a form of a square plate of 5×5 mm and the specific resistance p and the electromechanical coupling factor K were measured.
Based on the results of the above-described measurement, FIG. 1 and FIG. 2 respectively show changes in the specific resistance p and the electromechanical coupling factor K relative to the diffusion temperature in the first embodiment and the example for comparison. FIG. 3 and FIG. 4 respectively show changes in the specific resistance p and the electromechanical coupling factor K relative to the diffusion temperature in the second embodiment and the example for comparison.
It is apparent from FIGS. 1 and 3 that in both of the first and second embodiments, the piezoelectric ceramic in which the manganese compound and glass material are thermally diffused exhibit a decrease in the specific resistance ρ at a thermal diffusion temperature lower than that in the example for comparison (in which only the manganese compound was thermally diffused). On the contrary, in the example for comparison, the specific resistance ρ is too low at elevated temperatures. This makes it impossible to apply a polarizing electric field, which results in an abrupt decrease in the electromechanical coupling factor K as apparent from FIGS. 2 and 4.
Further, the specific resistance ρ of a piezoelectric ceramic on which thermal diffusion has been performed is subjected to less fluctuation due to temperature changes during the thermal diffusion process compared to the example for comparison. Therefore, when a thermal diffusion process is performed on a large volume, it is less susceptible to the influence of the temperature distribution of the furnace for the thermal diffusion process and the state of the grain boundary of the ceramic composition.
In addition, it is apparent from FIGS. 2 and 4 that the electromechanical coupling factor K is also at higher values than those in the example for comparison over a wide temperature range in spite of changes in the thermal diffusion temperature.
As described above, according to the present invention, a manganese compound and a glass material are deposited on the surface of a piezoelectric ceramic including at least a composite oxide of lead, zirconium and titanium, and thermal processing is performed thereafter to diffuse the deposited substance in a grain boundary portion of the piezoelectric ceramic. As a result, a piezoelectric ceramic is produced in which an oxide of manganese is distributed in a grain boundary layer at a density higher than that in a crystal grain of the piezoelectric ceramic and a glass phase exists in the grain boundary layer. Therefore, the properties required for a piezoelectric material can be obtained over a range of diffusion temperature in that the specific resistance ρ is low and the electromechanical coupling factor K is great.
Although the paste is applied on the surface of a ceramic using a method of applying it by means of screen printing in the above-described embodiments, the present invention is not limited thereto and, for example, methods of application such as brush painting and spraying may be used.
Further, although a piezoelectric ceramic having a composition of (Pb 0 .95 Sr 0 .03 La 0 .02) (Zr 0 .51 Ti 0 .49)O 3 was used in the above-described embodiments, the present invention is not limited thereto and, for example, it may be PZT type ceramics of two-component and three component types having other compositions or those obtained by substituting Sr, Ba, Ca, La and the like for a part of the lead in such materials.
Furthermore, although two types of paste for thermal diffusion including a manganese compound and a glass material in weight ratios of 3:7 and 5:5 were used in the above-described embodiments, the weight ratio between them is not limited to those values and may be arbitrarily set as needed.
In the above embodiments, manganese carbonate was used but the invention is not restricted to this compound. Other Mn compounds, or various combinations thereof, which form the oxides on heating can be used. The heating temperature is generally about 750-1100° C. but the invention is not limited to this range. Preferably, heating is carried out at about 900-960° C. The manganese compound and varnish used heretofor can be employed in this invention by adding a suitable glass thereto. Likewise, the nature of the glass is not restricted to the specific examples above. The amount of manganese compound or manganese oxide present, calculated as manganese dioxide, is generally about 0.005 to 0.5 wt % based on the weight of the ceramic and preferably about 0.005 to 0.3 wt %. The amount of the glass present is generally about 0.001 to 0.5 wt % based on the weight of the ceramic and preferably about 0.001 to 0.3 wt %. The manner in which the magnesium compound and glass are adhered to the surface of the piezoelectric ceramic is also not restricted.
While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects and, therefore, the appended claims are to encompass within their scope all such changes and modifications as fall within the true spirit and scope of this invention.
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There is provided a piezoelectric ceramic having a small mechanical factor of merit Qm and excellent heat-resisting properties, e.g., a piezoelectric ceramic for filter elements which is compatible with surface mounting and a method of manufacturing the same in a large amount and in a stable manner. There is provided a piezoelectric ceramic which is a composite oxide of at least lead, zirconium and titanium, wherein an oxide of manganese exists in a grain boundary layer in a density higher than that in a crystal grain of the piezoelectric ceramic and a glass phase exists in the grain boundary layer. It is manufactured by depositing a manganese compound and a glass material on the surface of a piezoelectric ceramic comprising a composite oxide of at least lead, zirconium and titanium and by performing thermal processing thereafter to diffuse the deposited substance in a grain boundary portion of the piezoelectric ceramic.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is claims priority to U.S. Provisional Application No. 61/585,035, filed on Jan. 10, 2012. The entire disclosure of the prior application is incorporated by reference herein in its entirety.
BACKGROUND
[0002] 1. Field of the Invention
[0003] This invention relates generally to fiber-reinforced polymer composites, preferably containing natural fibers, more preferably coconut coir fibers.
[0004] 2. Description of Related Art
[0005] Fiber-reinforced polymer composites containing synthetic or natural fibers have been used as construction materials in the past. Plastics reinforced with synthetic fibers possess high strength, but are expensive to produce. Unlike synthetic fibers, natural fibers are readily available. However, natural fibers are hydrophilic, which causes them to be incompatible with many hydrophobic polymers, including polyvinyl chloride (PVC) and polyolefins.
[0006] Coir is a natural fiber obtained from coconut husks. Coir fibers are strong, lightweight, and abundant. In the past, coir fibers have been used as reinforcement in polymeric composite materials. However, raw coir is normally hydrophilic, rendering them incompatible with polyolefins and PVC. Specifically, raw coir as used in the prior art include coir fibers and coconut pith. While coir fibers are comparatively hydrophobic, pith is very hydrophilic and is incompatible with polyolefins and PVC. Complete separation of coir and pith by physical processes has not been achieved in the prior art.
[0007] To overcome incompatibility between coir and a polymer matrix, coir-reinforced composites have been made using hydrophilic resins, including epoxy resins and polyurethanes. In many cases, epoxy resins and polyurethanes have reactive sites, such as epoxide or isocyanate functionalities, which can react with hydrophilic sites on the coir fibers.
[0008] Composites made from hydrophilic fibers and/or polymers present the difficulty that they have a tendency to absorb water, rendering them unsuitable for use in outdoor construction. Attempts to overcome this have been made by using polyolefins as matrix polymers in coir-reinforced materials. However, since coir used in the past is hydrophilic, this material has been found to be incompatible with hydrophobic polymers. As a result, coir-reinforced polyolefin composites of the prior art use chemically modified coir. Coir, as used in these composites, has been modified to incorporate hydrophobic groups into the coir structure, increasing compatibility between the coir and the polyolefin.
[0009] The current disclosure relates to fiber-reinforced polymer composites containing natural coir fibers and a hydrophobic matrix polymer. Compatibility between the coir fibers and the hydrophobic matrix polymer is increased without requiring chemical modification of the fibers.
SUMMARY
[0010] In light of the present need for improved reinforced polymer composites containing natural fibers, a brief summary of various embodiments is presented. Some simplifications and omissions may be made in the following summary, which is intended to highlight and introduce some aspects of the various exemplary embodiments, but not to limit the scope of the invention.
[0011] Various embodiments disclosed herein relate to composite boards manufactured from hydrophobic polymers, i.e., PVC or polyolefins, and hydrophobic coconut coir fibers which have been treated to remove coconut pith therefrom. In various embodiments, the composite board is manufactured without any step of chemically modifying coconut coir fibers. In various embodiments, the coconut coir fibers have been treated to remove at least a portion of the coconut pith therefrom. In various embodiments, the coconut coir fibers have been treated to remove substantially all of the coconut pith therefrom.
[0012] In certain embodiments, the composite board is manufactured by removing at least a portion of the coconut pith from coconut coir fibers using a cyclonic separator; combining coconut coir fibers with a hydrophobic polymer to form a mixture; and extruding the mixture to form a composite board. In some embodiments, the composite board is manufactured by removing substantially all of the coconut pith from coconut coir fibers using a cyclonic separator; combining coconut coir fibers with a hydrophobic polymer to form a mixture; and extruding the mixture to form a composite board.
[0013] Various embodiments relate to a process of preparing a composite board by removing at least a portion of the coconut pith from coconut coir fibers; combining the coconut coir fibers with a polymer to form a mixture, and extruding the mixture to form a composite board. Removal of at least a portion of the coconut pith from coconut coir fibers may be done by abrading the coir fibers to release pith from the coir fibers, entraining the coir fibers and pith in a high-velocity stream of heated air, and separating coir fibers from the air stream in a cyclonic separator. Coir fibers may be collected in a hopper or vessel beneath the cyclonic separator while a high-velocity air stream exiting the cyclonic separator carries the lightweight pith. The hydrophobic polymer may be an olefin homopolymer, an olefin copolymer, polyvinyl chloride, polyvinylidine chloride, polystyrene, or a mixture thereof. The polymer may be virgin polymer, recycled polymer, or regrind polymer. The polymer is preferably polyethylene or polypropylene. The polymer is preferably either virgin polymer or recycled polymer, such as virgin polyethylene, recycled polyethylene, virgin polypropylene or recycled polypropylene.
[0014] In various embodiments, the polymer is combined with the coconut coir fibers and mixed in an extruder. The mixture of the coir fibers and the polymer is mixed in the extruder, and the resulting coir fiber-polymer mixture is extruded to form a composite product. The composite product may be a composite board. Alternatively, the composite product may be a plurality of pellets.
[0015] Pellets formed from the mixture by extruding may be supplied to a second extruder, and melted in the second extruder. The molten pellets may then be extruded to form a composite board.
[0016] Various embodiments of the current disclosure are directed to a composite board which has been manufactured from coconut coir fibers which have been treated to remove at least a portion of the coconut pith therefrom; and a polymeric matrix comprising a polymer selected from the group consisting of olefin homopolymers, olefin copolymers, polyvinyl chloride, polyvinylidine chloride, polystyrene, and mixtures thereof. Preferably, the coconut coir fibers have not been chemically modified. Preferably, the coconut coir fibers have been treated to remove substantially all of the coconut pith therefrom.
[0017] In some embodiments, the polymer matrix may include additives which do not chemically modify the fiber structure. These additives may include colorants, i.e., pigments or non-reactive dyes, or plasticizers.
[0018] In various embodiments, the polymer matrix for the composite board comprises a thermoplastic material, i.e., polyethylene or polypropylene, in combination with coconut coir fibers treated for removal of pith. The polymer matrix may contain an optional organic filler selected from the group consisting of ramie fibers, bamboo fibers, rice hulls, wheat husks, linen, jute, bagasse, corn husks, and sawdust. The polymer matrix may also contain an optional inorganic filler such as glass fibers, carbon fibers, mineral fibers, silica, alumina, titania, carbon black, nitride compounds, and carbide compounds.
[0019] In various embodiments, the polymer matrix for the composite board contains UV stabilizers which reduce the likelihood of the composite board undergoing degradation from exposure to ultraviolet light. Such UV stabilizers include organic light stabilizers, such as benzophenone light stabilizers, hindered amine light stabilizers, and benzotriazoles; and inorganic light stabilizers, such as barium metaborate and its hydrates.
[0020] In various embodiments, the polymer matrix for the composite board contains antifungal agents which increase resistance of the board to mold and other organisms. The antifungal agents may be incorporated into the binder of the composite board. Useful antifungal agents include copper (II) 8-quinolinolate; zinc oxide; zinc-dimethyldithiocarbamate; 2-mercaptobenzothiazole; zinc salt; barium metaborate; tributyl tin benzoate; bis tributyl tin salicylate; tributyl tin oxide; parabens: ethyl parahydroxybenzoate; propyl parahydroxybenzoate; methyl parahydroxybenzoate and butyl parahydroxybenzoate; methylene bis(thiocyanate); 1,2-benzisothiazoline-3-one; 2-mercaptobenzo-thiazole; 5-chloro-2-methyl-3(2H)-isothiazolone; 2-methyl-3(2H)-isothiazolone; zinc 2-pyridinethiol-N-oxide; tetra-hydro-3,5-di-methyl-2H-1,3,5-thiadiazine-2-thione; N-trichloromethyl-thio-4-cyclohexene-1,2-dicarboximide; 2-n-octyl-4-isothiazoline-3-one; 2,4,5,6-tetrachloro-isophthalonitrile; 3-iodo-2-propynyl butylcarbamate; diiodomethyl-p-tolylsulfone; N-(trichloromethyl-thio)phthalimide; potassium N-hydroxy-methyl-N-methyl-dithiocarbamate; sodium 2-pyridinethiol-1-oxide; 2-(thiocyanomethylthio)benzothiazole; and 2-4(-thiazolyl)benzimidazole.
[0021] The polymer matrix for the composite board may contain additives which help provide strength and scratch resistance to the board surface. Additives which help increase scratch resistance to the board surface include lubricants and very hard mineral fillers, including carbide and nitride ceramics.
[0022] The board surface may also include inorganic pigments, organic pigments, or dyes as colorants. The board surface may be embossed with a decorative pattern, i.e., wood grain or imitation stone.
[0023] The current disclosure also relates to a method of producing hydrophobic coconut coir fibers by chopping coconut husks to produce raw coconut coir; releasing hydrophilic coconut pith from the coconut coir by abrading the coconut coir; separating the hydrophilic coconut pith from the coconut coir fibers in a cyclonic separator; and recovering hydrophobic coconut coir fibers from the cyclonic separator.
[0024] In certain embodiments, hydrophobic coconut coir fibers are prepared by chopping coconut husks to produce raw coconut coir; releasing hydrophilic coconut pith from coconut coir fibers by abrading the coconut coir; drying the coconut pith and the coconut coir fibers in an air stream, preferably a heated air stream; separating the coconut pith from the coconut coir fibers in a cyclonic separator; and recovering hydrophobic coconut coir fibers from the cyclonic separator.
[0025] Various embodiments disclosed in the current disclosure relate to building materials prepared using coir fibers having low pith content or no pith content, contained in a matrix binder. In various embodiments, the matrix binder is a thermoplastic or thermosetting polymeric binder. The matrix binder may be a thermoplastic binder. The thermoplastic binder may be a polyester, a polycarbonate, a polyolefin, polystyrene, a copolymer of at least one olefin having from two to twelve carbon atoms and a second vinyl monomer, i.e., styrene, a vinyl ester, a vinyl halide, or an ester of an unsaturated acid; polyvinyl halide, or polyvinylidine halide. The thermoplastic binder is preferably a polyolefin, polyvinyl halide, or polyvinylidine halide, more preferably polypropylene, polyethylene, high density polyethylene, low density polyethylene, linear low density polyethylene, or medium density polyethylene. Composites with thermoplastic binders may be prepared by extrusion molding.
[0026] The thermosetting binder may be a phenol-formaldehyde resin, an epoxy resin, or a urea-formaldehyde resin. In various embodiments, coir fiber may be used in a composite having a cement, plaster, or other mineral binder. According to various embodiments, composites with thermosetting binders or mineral binders, i.e., cement binders, may be prepared by compression molding in a press to form large sheets or to form planks or boards.
[0027] In various embodiments, the current application is directed to building materials prepared using a composition containing from 5% to 70% by weight of coir fibers prepared by the process described herein; optionally various processing additives, including colorants, i.e., dyes or pigments; fillers; plasticizers, and other additives; with the balance of the composition being a thermoplastic, thermosetting, or mineral matrix binder.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] In order to better understand various exemplary embodiments, reference is made to the accompanying drawings, wherein:
[0029] FIGS. 1-4 show mills suitable for grinding coir chunks into coir fibers and pith;
[0030] FIG. 5 shows a mechanism for entraining coir fibers and pith in an air stream, which may be a heated air stream;
[0031] FIG. 6 shows a first embodiment of a cyclonic separator for separating coir fibers from pith;
[0032] FIG. 7 shows a second embodiment of a cyclonic separator for separating coir fibers from pith;
[0033] FIG. 8 shows an extruder for mixing coir fibers and polymer and extruding the resulting mixture to form pellets; and
[0034] FIG. 9 shows an extruder for melting pellets of coir fibers and polymer and extruding the molten pellets to form a board.
DETAILED DESCRIPTION
[0035] Referring now to the drawings, in which like numerals refer to like components or steps, there are disclosed broad aspects of various exemplary embodiments.
[0036] The present disclosure relates to a composite board manufactured using coconut coir fibers. Coconut coir, in its raw state, includes coconut coir fibers, which are comparatively hydrophobic natural fibers, and coconut pith, which is hydrophilic. The present disclosure uses coconut coir, preferably dry coconut coir, more preferably coconut coir having a moisture content of between 2% and 8%, most preferably coconut coir having a moisture content of 6%. The coconut coir may be dried in a rotating drum heater, preferably a rotating drum natural gas fired heater.
[0037] The current disclosure describes an improved method of separating coir fibers from pith. In a first step, coconut husk is chopped to produce coir chunks. In certain embodiments, the chopping step is carried out in a knife mill.
[0038] In certain embodiments, the knife mill has a rotor powered with an engine, i.e., a gasoline or electric engine, and a plurality of straight knife blades bolted to the periphery of the rotor. In various embodiments, coconut husk is added to a knife mill by a conveyer belt. The conveyer belt may include a slotted orienter to control orientation of coir chunks as they enter the knife mill; control of coir chunk orientation allows preparation of coir fibers having consistent lengths. In other embodiments, coconut husk is added to a knife mill by a hopper. The conveyer belt may include a magnet to prevent wrenches or other loose equipment from killing or damaging the knife mill.
[0039] When coconut husk is added to the knife mill, rotation of the rotor chops the aligned coconut husk into small pieces or chunks comprising consistent length coconut coir fibers and coconut pith. The coir and pith are not easy to separate from these coir chunks. The chopping step is preferably carried out on dry coir, preferably coconut coir having a moisture content of between 2% and 8%, more preferably coconut coir having a moisture content of 6%. Alternatively, the chopping step may be carried out on coir having a higher moisture content. If chopping is carried out on wet coir, the resulting coir chunks may be dried prior to further processing.
[0040] To release pith from coir chunks, coir chunks are abraded in a mill. In certain embodiments, wet or dry coir chunks are abraded in a contra-selector mill, as seen in FIG. 1 . The contra-selector mill includes a rotating screen basket 81 . Coir chunks 82 are deposited into the basket from inlet 83 . An impellor 84 having blades 85 rotates simultaneously with rotation of the basket 81 . The impellor 84 and the screen basket 81 may rotate in the same direction, or the impellor 84 and the screen basket 81 may rotate in opposite directions. Preferably, the impellor 84 and the screen basket 81 rotate in opposite directions to produce fibers. As the impellor 84 and the screen basket 81 rotate, coir chunks are ground or abraded between the blades 85 and grinding elements on the inner surface of the basket 81 . As the coir chunks are ground, centrifugal forces cause the ground particles to pass through openings in the screen basket 81 . The fiber size may be controlled by adjusting the rotation speed of the impellor 84 and the screen basket 81 , and/or the size of the openings in the screen basket 81 . The ground particles comprise coir fibers and coconut pith, and fall into a trough or hopper where they are collected after passing out of the screen basket.
[0041] According to various embodiments, wet or dry coir chunks are abraded in a contra selector mill. Abrasion of the coir fiber bundles in the mill opens the pith pockets. In certain embodiments, coir is collected in a wet state, and then the coir is stored inside for days before processing. As a result, the coir is partially dried prior to abrasion in the contra selector mill. Ground particles comprising coir fibers and coconut pith received as an output from the contra selector mill are sent to a rotating drum drier. In the rotating drum drier, the drying and rotating action of the drier causes dry pith particles to be released from the coir fibers.
[0042] In an alternative embodiment, coir chunks may be ground or abraded in a ball mill in the presence of spherical grinding media 101 , as seen in FIG. 2 . The ball mill has a hollow body 100 . A high speed air stream may be passed through the ball mill. As the ball mill grinds the coir chunks into individual coir fibers and pith particles, the coir fibers and pith particles are entrained in the air stream and exit the ball mill through screen 102 . Screen 102 retains grinding media 101 in the ball mill. The size of the coir fibers and pith particles is controlled by the size of the openings in the screen.
[0043] Alternatively, coir chunks may be ground or abraded in a hammer mill, as seen in FIG. 3 . Coir chunks are deposited in feed hopper 201 , and pass into mill chamber 202 . The coir chunks are reduced in size by impact with rotating hammers 204 mounted on a rotor 203 . The impact between the hammers 204 and the coir chunks shatters the coir chunks, releasing pith from coir fibers. As the coir chunks are reduced in size to the desired degree, forming pith particles and coir fibers, the pith particles and coir fibers 207 pass through a screen 205 into the bottom of the hammer mill and are collected in a container or hopper 206 , and then sent to a rotating drum drier.
[0044] Coir chunks may also be ground or abraded to release coir fibers and pith particles in an oscillating granulator, as seen in FIG. 4 . Coir chunks are placed in a hopper 300 . Below the hopper is an oscillating bar 301 which contacts a woven wire screen 302 . Coir chunks are abraded by shear between the oscillating bar 301 and the woven screen 302 as the bar oscillates back and forth. Coir fibers and pith particles pass through the wire screen 302 , and are collected in a container or hopper, and may then be sent to a rotating drum drier.
[0045] Other devices for abrading or milling large particles may be used to reduce the size of coir chunks and release pith particles from coir fibers.
[0046] Next, dry coir fibers and pith particles recovered from abrasion or milling of dry coir chunks, optionally followed by drying in a rotating drum drier, are entrained in a heated air stream. If abrasion or milling is performed in a ball mill, this step is preferably accomplished by passing a stream of high velocity heated air through the ball mill, as seen in FIG. 2 . If abrasion or milling is performed in a contra-selector mill, hammer mill, or oscillating granulator, then the venturi effect is used to entrain the coir fibers and pith particles in a heated air stream, as seen in FIG. 5 . The coir fibers and pith particles 401 are loaded into a hopper or tank 402 with a small hole 403 at its lower end. This hole 403 opens into a tube 404 carrying a high velocity air stream. As the air stream passes the hole 403 in the hopper or tank 402 , producing a partial vacuum in the hole 403 in the hopper or tank, coir fibers and pith particles from the hopper or tank are sucked into the high velocity air stream. The high velocity air stream carries the coir fibers and pith particles into a cyclonic separator, discussed below. The cyclonic separator separates heavy coir fibers from the air stream, producing an air stream with entrained lightweight pith particles. It is important to note the importance of drying coir prior to introducing coir fibers and pith particles into the cyclonic separator. If the coir is not properly dried, the pith particles will be wet and heavy, and will not properly separate from the heavy coir fibers. The coir fibers recovered after separation from pith have a length of from 0.1 to 5 mm, preferably 0.2 to 2.5 mm, more preferably 1 to 2 mm.
[0047] FIG. 6 shows a cyclonic separator 501 for separating coir fiber from coconut pith. Cyclonic separator 501 includes a tubular body 502 having an opening at each end. The lower end 503 of body 502 is conical, while the upper end of body 502 is cylindrical. Cyclonic separator 501 includes an inlet 504 for a stream of air containing entrained coconut coir fibers and lightweight coconut pith. Inlet 504 injects the airstream tangentially relative to the wall of the cylindrical portion of cyclonic separator 501 , establishing a helical flow of air inside the cyclonic separator. Particles entrained in this helical air flow are subjected to centrifugal force, directing the particles radially outward toward the wall of body 502 , and to a buoyant force, in which the air in the helical air stream supports the particles. The buoyant force opposes the centrifugal force. The position of a particle in the helical air stream is controlled by a balance between centrifugal and buoyant forces. In general, a particle in the cyclone moves toward either the wall of the cyclone, or the central axis of the cyclone until the buoyant and centrifugal forces are balanced. Denser particles, i.e., heavy coir fiber particles, move to the outer wall of body 502 , and lighter pith particles move toward the axis of the cyclone. As the dense coir fibers move toward the wall of body 502 , they strike the outside wall, and fall to the bottom of the cyclone where they can be removed through an opening in the bottom of conical end 503 .
[0048] The pith is lightweight, and continues to be entrained in the helical air flow until it reaches the junction of the cylindrical portion of body 502 and the conical portion 503 of body 502 . This junction interrupts the helical air flow. The air then exits the cyclone in a straight stream through the center of the cyclone and out opening 505 in the top of body 502 . The coconut pith is still entrained in the air stream, and is also removed through opening 505 .
[0049] FIG. 7 shows an alternate embodiment of a cyclonic separator for separating coir fiber from coconut pith. Cyclonic separator 510 includes a tubular body 511 having an entrance 512 at one end, and an exit 517 at the other end. Entrance 512 injects an airstream containing air and entrained coir fibers and pith particles axially into the center of the tubular body 511 of cyclonic separator 510 . Entrance 512 includes a means 513 for establishing a helical flow to the airstream as it exits entrance 512 , establishing a helical flow of air in the direction of arrow B inside the cyclonic separator. Means 513 may take the form of stationary spinner vanes in entrance pipe 512 . Particles entrained in this helical air flow in the direction of arrow B are subjected to centrifugal and buoyant forces, directing the particles radially outward toward the wall of body 511 . Denser particles, i.e., heavy coir fiber particles, move toward the outer wall of body 511 , and lighter pith particles move toward the axis of the helical airflow B.
[0050] Simultaneously with introduction of an airstream containing air and entrained coir fibers and pith particles through entrance 512 , a secondary air stream enters chamber 515 through inlet 514 . Secondary air nozzles 516 inject air at high speed tangentially into body 511 , creating a second helical airflow along the inner wall of body 511 , in the direction of arrow A. Helical airflow A surrounds airflow B, and moves toward entrance 512 while airflow B moves toward exit 517 . Helical airflow A entrains coir fiber particles exiting airflow B due to centrifugal force. Airflow A prevents damage to the inner wall of body 511 from impact with coir fibers, and moves coir fibers in the direction of entrance 512 . Near entrance 512 , airflow A strikes baffle 519 , stopping the helical airflow. At this point, air from airflow A begins to flow toward exit 517 in the direction of arrow C. Air moving in the direction of arrow C and airflow B combine and exit the body 511 through exit 517 , along with entrained pith. When airflow A strikes baffle 519 , entrained coir fibers are released and are carried into hopper 518 for recovery.
[0051] Other embodiments of cyclonic separators are known in the art, and may be used to separate coir fibers from pith particles.
[0052] Within the cyclonic separator, air flow and collisions further separate the pith from the coir fibers. The fibers that fall to the bottom of the cyclone may also still have some coir chunks included. The coir chunks are separated from coir fibers by a vibrating or oscillating screen separator. Separated coir fibers go through the screen separator, while coir chunks are caught and returned to the conveyer leading to the knife mill for further processing. Typically, less than 10% of the output of the cyclonic separator consists of chunks that need further processing.
[0053] FIG. 8 shows an extruder 520 for blending a polymer with coir fibers recovered from a cyclonic separator according to FIG. 1 or FIG. 2 . The extruder 520 includes a tubular body 521 with at least one helical screw 522 rotatably mounted inside. Screw 522 is driven by a motor (not shown). Screw 522 has a helical thread 525 thereon. Extruder 520 can be an extruder with a single screw, or a dual screw extruder.
[0054] Extruder 520 includes a hopper or other inlet 523 for receiving pellets of a polymer. The polymer is preferably a hydrophobic polymer; more preferably an olefin homopolymer, an olefin copolymer, polyvinyl chloride, polyvinylidine chloride, polystyrene, or a mixture thereof; still more preferably an olefin homopolymer, an olefin copolymer, polyvinyl chloride, or polyvinylidine chloride; most preferably polyethylene or polypropylene.
[0055] Extruder 520 includes a second hopper or other inlet 524 for receiving coir fibers. The interior of the screw is heated sufficiently to melt the polymer pellets. Screw 522 rotates, causing the thread 525 to knead the molten polymer and mix the molten polymer with the coir fibers. The mixture of coir fibers and polymer is extruded from extruder 520 through die plate 526 , forming a strand of molten polymer 529 . A cutting device having, for example, a knife blade 528 reciprocating in the direction of arrow C, cuts the strand 529 at regular intervals, forming pellets 527 . Again, it is important to note the importance of drying coir early in the process disclosed herein; if the coir is not properly dried prior to separating the coir fibers and the pith, the resulting coir fibers will be wet. Preferably, the coir fibers are dried prior to their introduction into the cyclonic separator; more preferably, the coir fibers are dried to a moisture level of between 2% and 8% after grinding in a mill, i.e., a contra selector mill, but prior to their introduction into the cyclonic separator. Wet coir fibers have poor compatibility with hydrophobic polymers, when compared to dry coir fibers.
[0056] FIG. 9 shows an extruder 530 for extruding a blend of a polymer and coir fibers. The extruder 530 includes a tubular body 531 with at least one helical screw 532 rotatably mounted inside. Screw 532 is driven by a motor (not shown). Screw 532 has a helical thread 535 thereon. Extruder 530 can be an extruder with a single screw, or a dual screw extruder.
[0057] Extruder 530 includes a hopper or other inlet 533 for receiving pellets 527 , as produced by extruder 520 of FIG. 8 . Pellets 527 are melted in extruder 530 . Extruder 530 also optionally includes a second hopper or other inlet 534 for receiving colorants, i.e., pigments or non-reactive dyes; plasticizers; or other additives, preferably additives which do not react with reactive sites on the coir fiber, i.e., hydroxyl groups. Screw 532 rotates, causing the thread 535 to knead the molten pellets and, if necessary, mix the molten pellets with the additives. The mixture of molten pellets and additives is extruded from extruder 530 through die plate 536 , forming a strand of molten polymer 539 .
[0058] In certain embodiments, die plate 536 has a die with a rectangular hole, so that strand 539 has a width that is greater than its thickness. However, die plate 536 is not limited to a die with a rectangular hole. In some embodiments, die plate 536 has a die with a complex profile, so that strand 539 has a complex cross section. Strand 539 may be extruded as a hollow rectangular board with one or more support struts formed therein. Strand 539 may be extruded as a hollow or solid board with slots or notches formed therein, where the slots or notches allow multiple boards to be linked together. A cutting device having, for example, a knife blade 538 reciprocating in the direction of arrow D, cuts the strand 539 at regular intervals, forming boards 537 .
[0059] The process described herein produces boards that are strong, due to the reinforcing fibers. The boards may be produced in lengths of up to 25 feet and used as load-bearing materials, i.e., flooring for decks. The boards are environmentally friendly, and water resistant. The boards are also resistant to mold. The coir fibers and polyethylene are not readily digested by termites or other insects, so the boards are resistant to termite infestation.
[0060] As an alternative to coir fibers, the process disclosed herein may be carried out using ramie or bamboo fibers to reinforce polymeric products. In some embodiments, the process disclosed herein may be carried out using coconut coir fibers in combination with ramie or bamboo fibers to reinforce polymeric products. Ramie and bamboo fibers are readily available and inexpensive materials. Ramie and bamboo fibers are renewable and resemble wood. Coconut coir fibers are also renewable; however, coconut coir fibers are more expensive than ramie and bamboo fibers. Coconut coir fibers have distinct advantages over ramie and bamboo fibers. Coconut coir fibers have longer fibers with a greater aspect ratio than either ramie or bamboo fibers, and are therefore able to provide composite boards with greater strength than composite boards reinforced solely with ramie and bamboo fibers.
[0061] In various embodiments, a composite board is produced comprising a polymer binder and coconut coir fibers as a reinforcing additive. In various embodiments, a composite board is produced comprising from 3% to 100% by weight of coconut coir fibers and from 0% to 97% by weight of bamboo or ramie fibers, based on the total weight of the fibers, and a thermoplastic resin matrix. In various embodiments, the composite board comprises from 35% to 100% by weight of coconut coir fibers and 0% to 65% by weight of bamboo fibers, based on the total weight of the fibers, and a thermoplastic resin matrix. In various embodiments, the composite board comprises from 40% to 60% by weight of coconut coir fibers and 40% to 60% by weight of bamboo fibers, based on the total weight of the fibers, and a thermoplastic resin matrix. The precise ratio of coconut coir fibers to bamboo or ramie fibers may be adjusted to obtain a desired board strength at a desired cost/unit length. Specifically, the cost/unit length decreases as the ratio of coconut coir fibers to bamboo or ramie fibers decreases; however, the board strength increases as the ratio of coconut coir fibers to bamboo or ramie fibers increases.
[0062] In various embodiments, the composite board comprises from 20% to 80% by weight of a mixture of coconut coir fibers and an optional filler, based on the total weight of the mixture, and from 20% to 80% by weight of a thermoplastic resin. In some embodiments, the composite board comprises from 20% to 50% by weight of a mixture of coconut coir fibers and the optional filler, based on the total weight of the mixture, and from 20% to 50% by weight of the thermoplastic resin.
[0063] In cases when the practitioner wishes to produce a composite board, i.e., a particle board, having coir fibers and a thermosetting binder matrix, i.e., a phenol-formaldehyde, urea-formaldehyde, melamine, or epoxy resin matrix, the board may be prepared by mixing liquid polymer precursors and coir fibers. Coir fibers are mixed with a thermosetting resin, and the mixture is formed into a sheet. The mixing step may be carried out by spraying the resin onto the coir fibers.
[0064] Once the resin has been mixed with the particles, the liquid mixture is made into a sheet. The sheets formed are then compressed under pressures between two and three megapascals and temperatures between 140° C. and 220° C. This process sets and hardens the thermosetting resin. The resulting boards are then cooled, trimmed and sanded.
[0065] In cases when the practitioner wishes to produce a composite board having coir fibers and a mineral matrix, i.e., cement or gypsum, the board may be prepared by mixing liquid polymer precursors and coir fibers. Coir fibers are mixed with a mineral binder, i.e., gypsum, and the mixture is formed into a core sheet, which is sandwiched between facing sheets of paper or a nonwoven material. The core is allowed to set and dry until it is strong enough for use as a building material.
[0066] Composite boards made using coir fiber prepared as described herein and a thermoplastic resin binder or a thermosetting matrix binder having important advantages over composite boards made using raw coir, or other natural cellulosic materials, i.e., sawdust or other wood fillers. Composite boards made with coir fiber material as described herein may, in some circumstances, possess one or more of the following advantages:
[0067] The composite boards have high strength, due to coir fibers giving the material high flexural toughness and rigidity;
[0068] The composite boards are low in cost, due to the ready availability of raw coir and the lack of any need for chemical processing of coir after removal of pith;
[0069] The composite boards are low in moisture absorption, because coir fiber are hydrophobic;
[0070] Resistant to mold;
[0071] Resistant to termites and other wood eating bugs; and
[0072] Fire retardant, because coir fibers are denser and more self-extinguishing than wood fillers.
[0073] In composite boards containing wood, mold tends to grow on wood/plastic composite surfaces because the wood filler promotes mold growth. Coir fibers have a lower tendency than wood to promote mold growth; therefore, boards containing coir fiber as a reinforcing material are more resistant to mold growth than boards containing wood fillers. Also, coir fibers are resistant to termites and other insects, as they are harder for insects to digest.
Example 1
[0074] A series of composite boards were produced by extruding a composition containing 35% by weight recycled polyethylene as a binder, and 65% by weight of vegetable fibers. The vegetable fibers contained a mixture of coconut coir fibers and bamboo fibers; or coconut coir fibers in the absence of bamboo fibers. A comparative composite board was produced by extruding a composition containing 35% by weight recycled polyethylene as a binder, and 65% by weight of bamboo fibers, in the absence of coconut coir fibers. The composite boards were subjected to testing using test methods in accordance with ASTM D7032-10, “Standard Specification for Establishing Performance Ratings for Wood-Plastic Composite Deck Boards and Guardrail Systems,” and ASTM D6109-10, “Standard Test Methods for Flexural Properties of Unreinforced and Reinforced Plastic Lumber and Related Products.” The testing was conducted at a relative humidity of 50%±5%, and a temperature of 52° C. The test results were used to determine the maximum distance that a board having a cross section of 8″ by 1.25″ between two joists can safely span. The results are reported in Table 1. The coconut coir fibers were prepared by removing substantially all of the coconut pith from coconut coir fibers by abrading the coir fibers to release pith from the coir fibers, entraining the coir fibers and pith in a high-velocity stream of heated air, and separating coir fibers from the air stream in a cyclonic separator.
[0075] As seen in Table 1, the maximum joist span at a relative humidity of 50%±5%, and a temperature of 52° C., increases from 16 inches at a coconut coir fiber content of 0-5% by weight of the board to 36 inches at a coconut coir fiber content of 65% by weight of the board. The maximum joist span at a relative humidity of 50%±5%, and a temperature of 52° C., was 30 inches for a board having a coconut coir fiber content of 45-55% by weight of the board, and a bamboo fiber content of 10-20% by weight. Use of a coconut coir fiber content of 33% by weight of the board and a bamboo fiber content of 33% by weight increases the maximum joist span by 50%, when compared to a board having only bamboo fibers.
[0000]
TABLE 1
Impact of Coconut Coir Fiber Content on Joist Span Capability.
TEST INFO
DECK/DOCK
BOARD FORMULAE
JOIST SPAN
COIR
BAMBOO
RECYCLED
CAPABILITY
FIBER %
FIBER %
Polyethylene
(INCHES)
% CHANGE
0%
65%
35%
16
BASELINE
5%
60%
35%
16
100%
25%
40%
35%
24
150%
33%
33%
35%
24
150%
45%
20%
35%
30
188%
55%
10%
35%
30
188%
65%
0%
35%
36
225%
[0076] Although the various embodiments have been described in detail, it should be understood that the invention is capable of other embodiments and its details are capable of modifications in various obvious respects. As is readily apparent to those skilled in the art, variations and modifications can be affected while remaining within the spirit and scope of the invention. Accordingly, the foregoing disclosure, description, and figures are for illustrative purposes only and do not in any way limit the invention, which is defined only by the claims.
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A composite board is manufactured from hydrophobic coconut coir fibers which have been treated to remove at least a portion of coconut pith therefrom; and a hydrophobic vinyl polymer, such as a polyolefin. The composite board is manufactured without any step of chemically modifying coconut coir fibers. The composite board is manufactured by removing at least a portion of coconut pith from coconut coir fibers using a cyclonic separator; combining coconut coir fibers with a hydrophobic polymer to form a mixture; and extruding the mixture to form a composite board.
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BACKGROUND OF THE INVENTION
The present invention relates to the control of fuel gas flow to a burner and particularly to techniques for remotely varying the amount of fuel flow for maintaining the burner flame at a desired amount or level. The invention relates particularly to techniques for electrically remotely controlling the flow of gaseous fuel to a burner and more specifically to remote control of an electrically operated valve for modulating gas flow to the burner.
Heretofore, electrically operated valves employed for controlling flow fuel gas to a burner have been of the type having two states: either fully closed or fully open; and, the heat output of the burner is thus controlled by the percentage of the time during which the valve was fully opened. In fuel burners for furnaces and boilers utilized in heating buildings, typically the electrically operated burner valve is controlled by a thermostat which senses ambient temperature in the building and cycles the valve and burner ignition system accordingly.
It has been desired to provide for remote control of an electrically operated fuel gas valve in a cooking appliance in which heretofore the fuel gas valve has been either modulated manually by the user for surface burner control; or, an on/off electrically operated valve has been employed for the oven burner of the cooking appliance.
The competitiveness of the market for mass produced household cooking appliances requires that the cost of the burner and oven controls be minimized in order to facilitate manufacture and sale of the appliance. It has thus particularly been desired to provide a remotely controlled or modulating gas burner valve which enables such operation of a household range or oven in a manner which permits the range or oven to be sold competitively with cooking appliances which employ all-electric heating. Heretofore, all-electric appliances have provided on a cost competitive basis in the household cooking appliance market the ability to remotely or automatically control the level of heat by controlling the current flow in the electrical resistance heating elements in the top burner or oven easily and competitively by electrical or electronic means.
It has thus been long desired to provide a simple and reliable electrically operated modulating valve for a fuel gas burner which is reliable and sufficiently low in manufacturing costs to enable the burner control system to compete in the marketplace with all-electric heating element control systems.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide remote control of an electrically operated valve for modulating fuel gas flow to a burner.
It is another object of the invention to provide remote control of an electrically operated gas burner valve having a poppet for closing the valve and openable by an electromagnetic actuator and a metering member moveable with the poppet for providing metering or modulating of the gas flow with the poppet in the open position.
It is another object of the invention to remotely control an electrically operated gas burner valve having a poppet for closing the valve and opening the poppet with an electromagnetic actuator having a coil and permanent magnet for providing movement of the poppet to current flow in the coil for opening the valve and thereafter providing modulated flow.
The remotely controlled electrically operated modulating burner control system of the present invention employs an electromagnetically operated valve which has a poppet with a metering member attached thereto for modulating or metering gas proportional to current flow in the electromagnet actuator flow when the poppet is in the open position. The metering member is configured such that initial opening of the poppet from the valve seat provides maximum flow and continued movement of the poppet reduces the flow proportional the current to a minimum metered amount when the poppet is in the fully open position. The electromagnetic actuator employs an electrical coil proximate an annular permanent magnet with one of the coil and magnet attached to the poppet for movement therewith and the other of the coil and magnet mounted on the body of the valve. In the preferred practice, the coil is moveable with the poppet and metering member; and, the permanent magnet is mounted to the valve body. In one embodiment the metering member comprises a cylindrical spool having a groove or recess therein; and, in another embodiment the metering member comprises a conically tapered member disposed in a conically tapered metering passage. The burner control system of the present invention employs an electrically operated electromagnetically actuated poppet valve having a metering member attached thereto for modulating or metering gas flow when the valve is in the open position generally corresponding to the level of energization of the electromagnetic actuator. The burner control system of the present invention employs an electrically operated electromagnetically actuated shut-off and metering valve for modulating fuel gas flow to a burner and which is easily controlled by a simple user input such as a variable voltage from a potentiometer to provide flow proportional to the potentiometer setting. The present invention is easy to manufacture and assemble and is low in cost thereby providing application to the highly competitive household cooking appliance market.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic of a burner control system as applied to a top burner for a household cooking appliance;
FIG. 2 is a cross-section of the preferred valve of the system of FIG. 1;
FIG. 3 is an enlarged view of a portion of the valve of FIG. 2;
FIG. 4 is a portion of a section view taken along section indicating lines 4--4 of FIG. 3;
FIG. 5 is a portion of a cross-section of an alternate embodiment of the valve of FIG. 2;
FIG. 6 is a right hand side view of the embodiment of FIG. 5;
FIG. 7 is a section view taken along section indicating lines 7--7 of FIG. 6;
FIG. 8 is a view similar to FIG. 5 of another embodiment of the valve of FIG. 2;
FIG. 9 is a section view taken along section indicating lines 9--9 of FIG. 8;
FIG. 10 is a view similar to FIG. 2 of another embodiment of the valve of FIG. 1;
FIG. 11 is a plot of values of flow rate as a function of coil current for the valve of FIG. 2; and,
FIG. 12 is a plot of flow rate as a function of metering valve position for the valve of FIG. 10.
DETAILED DESCRIPTION
Referring to FIG. 1, a burner control system is indicated generally at 10 and includes a fuel line or conduit 12 adapted for attachment to a source of gaseous fuel and which is connected to the inlet 16 of an electrically operated modulating valve indicated generally at 14. Valve 14 has an outlet 17 connected to a burner tube or conduit 18 which supplies fuel gas to the aspirator inlet 20 of a burner 22.
The electrically operated valve 14 is connected to the electrical leads 24,26 to an electrical or electronic controller 28 which receives power from power line leads 30,32. The controller receives a control input through leads 34,36 connected to a user input control 38 which may comprise a potentiometer or variable resistance which is operated by user rotation of knob 40 provided on the control console or panel 42 which may be remotely located from the burner 22.
An electrical ignitor typically a spark ignitor 44 is disposed adjacent the burner and is connected by leads 46,48 to a spark or ignitor control circuit device 50 which may be located at a convenient location such as proximate the ignitor 44, and is connected to the controller 28 by leads 52,54. It will be understood that alternatively the ignitor control circuit 50, which is well known in the art, may also be included with the controller 28. A flame sensor 56 is disposed adjacent the burner and provides a signal along leads 58,60 to the controller 28 for enabling the controller to prevent opening of the valve 14 if ignition has not occurred, or to close the valve in the event the flame has gone out with the valve in the open condition.
It will be understood that the ignitor 44, ignitor control circuit 50, valve 14 and flame sensor 56 may be located remote from the control panel 42 in a common housing structure with burner 22 as indicated in dashed outline by reference numeral 62.
Referring to FIG. 2, the preferred form of the valve 14 in the present invention is shown as having a valve body or housing 64 which has a valving cavity 66 therein which communicates with a valve seating surface 68 which may be formed on a separate insert member 70 and which seating surface surrounds an outlet metering passage 72 which communicates with passage 74 provided in outlet 17. A resilient preferably elastomeric poppet 76 is disposed closed against the seating surface 68. Poppet 76 is attached to a valve member 78 which has a metering portion or rod 80 formed thereon which extends into and closely interfits in sliding engagement the metering passage 72. The valve inlet passage 16 communicates with the valving chamber 66 such that upon downward movement of the poppet 76 and valve member 78 gas flows through the annular space between metering rod 80 and passage 72 and outwardly through outlet passage 74.
Moveable valve member 78 has a bobbin member 82 attached thereto upon which is wound coil 84 which moves with the valve member 78. The remote end 86 of valve member 78 is piloted in a bushing 88 having a flanged end 89 against which one end of a spring 90 is registered with the opposite end of spring 90 registering against a flange 92 provided on the valve member. The flanged end 89 of bushing 88 has the underside thereof registered on a ferromagnetic pole piece configured as annular disc 94 which is registered against the end of annular permanent magnet 96 which is disposed concentrically and preferably within coil 84. Bushing 88 extends through annular magnet 96 through an aperture 91 formed in a ferromagnetic cupshaped pole member 93. The lower end of bushing 88 is flared outwardly to retain the magnet and disc 94 on the cup-shaped member as a subassembly.
In the presently preferred practice of the invention the electromagnetic actuator has the coil mounted on the moving armature. The stationary portion of the magnetic circuit comprises the permanent magnet 96, the cup-shaped steel pole piece member 93, and steel annular disc 94. The circuit is completed radially across the moving coil 84 from disc 94 to the cup-shaped pole piece 93. The annular disc 94 serves to concentrate flux from magnet 96 radially across the coil 84 to produce an axially directed force on the armature when current flows in coil 84; and, this axial force overcomes the force of spring 90 to move the armature and valve member in a downward direction in FIG. 2. It will be understood that the axial force on the armature is proportional to the number of ampere-turns of current in the coil. Thus, if the return of spring 90 has a linear force versus deflection relationship, the downward movement or displacement of the armature will be proportional to the ampere-turns of current in the coil. The arrangement of the magnetic circuit of the invention wherein magnetic flux is concentrated at the outer cylindrical surface of disc 94 functions to maintain the magnitude of the axial force, per ampere-turn substantially constant for a given current flow as the armature is moved with respect to the disc 94.
In the presently preferred practice, the outlet fitting 17 is retained over the insert 70 by suitable fasteners such as screws 110. Similarly the lower end of the body of the valve and chamber 66 is closed by the cap member 112 which is retained by fasteners such as screws 114. A cover screw 98 is provided through cap 112 to provide a cover over an adjustment screw which serves as an adjustable limit stop for downward movement of the valve member with respect to FIG. 2. Leads 100,102 are attached to the coil 84 and pass through an opening 104 provided in the valve body 64.
The arrangement of the valve of FIG. 2 thus provides a lightweight moveable armature in the form of the valve member 78, bobbin 82 and coil 84.
Referring to FIGS. 3 and 4, the metering rod 80 is shown as having a groove or recess 106 therein which, preferably as shown in FIG. 4 has a constant width. The lower edge end of the groove is preferably formed at a radius "r" as is the upper edge end which intersects a ramped or tapered end portion denoted by reference numeral 108. The configuration of the groove shown in FIGS. 3 and 4 provides, upon opening of the poppet and in downward movement of the rod 80 to the fully open position, as shown in dashed outline an initially maximum flow as gas flows through the deeper portion 106 of the groove. As the rod 80 continues to move downward causing tapered portion 108 to move into the metering passage 72, flow through groove 106 is reduced; and, flow is through the portion of the groove denoted by reference numeral 108. As the ungrooved portion of rod 80 enters passage 72, flow is diminished to a minimal amount determined by the annular clearance between rod 80 and passage 72 which is sufficient to maintain the burner flame at a low level.
In the presently preferred practice of the invention, the coil is designed to operate on very low current in the range 20 to 140 milliamps at 24 volts DC and has 800 to 1200, preferably 1000, turns of fine wire of number 37 to number 39 AWG. A metering rod having a diameter of about 3.6 millimeter has a groove width of 1.78 millimeters and provides a maximum flow of 43 cubic centimeters per sec (cm 3 /sec) at a supply pressure of 25 centimeters of water column (25 cmH 2 O).
Referring to FIG. 12, the maximum flow for the valve of FIG. 2 is shown to occur at a position of movement of the poppet of about 0.58 millimeters from the poppet closed position; and, the flow decreases substantially linearly with movement referred to as throttle travel in FIG. 12 of the metering rod 80 to a fully open position of 4.4 millimeters from the poppet closed position where the flow has decreased to its minimum level. It will be seen from FIG. 12 that the electromagnetic actuator comprising coil 84 and annular permanent magnet 96 provide a flow which is substantially proportional to the movement of the valve member metering rod 80. Thus, a simple controller such as a potentiometer may be employed for the user input control 38 to position the valve member at any proportional position of its full travel limit by dialing a corresponding percentage of full rotation of the user control knob 40.
In the presently preferred practice of the invention, the dimension denoted by the reference character "L" in FIG. 3 denotes the length of the metering passage 72 which in the present practice of the invention is about 5.1 millimeters. The radius "r" at the ends of groove 106 is formed by a 6.35 millimeter diameter rotary cutter which gives a radius of 3.175 millimeters. It will be understood that the groove 106 has its length determined by the dimension "L", inasmuch as the end of the tapered surface 108 must enter the metering passage 72 before the lower end of the valve member 78 hits the upper end of the limit stop screw 98.
Referring to FIGS. 5, 6, and 7, another embodiment of the valve member is indicated at 178 as having a pair of spaced generally parallel recesses 116, 118 formed on the valve member 178 on opposite sides of a central land 120. The groove 116 and the groove 118 each have the leading or lower ends thereof configured to a radius "r"; however, the trailing or upper ends of groove 116 is tapered, denoted by references numeral 122, at a lesser slope than the tapered portion 124 of the land 118.
Referring to FIGS. 8 and 9, another embodiment of the metering valve member is illustrated at 278 as a separate fitting retained on the valve member 278 by a central bolt 126 which has a ball 128 formed on the upper end thereof and which is pivoted in a socket 130 formed in the end of metering member 280. The bolt 126 has a diameter slightly less than the central passage 132 formed in the metering member to accommodate misalignment of the metering member 280 with respect to the metering passage 72. The metering member 280 is retained by a Belleville washer 134 having its outer periphery engaging an undercut in the metering member.
Referring to FIGS. 8 and 9, a metering groove 136 is formed in the metering member 280 and has a triangular or V-shaped cross-section as shown in FIG. 9. The groove 136 has a constant area cross-section lower portion with a trailing or upper portion ramped as denoted by reference numeral 138. It will be understood that the bolt 126 passes through the poppet 276 to engage the valve member 278. It will be understood with reference to FIG. 8 that the lower or leading edge of groove 136 extends to the lower end of the metering member 280 which is spaced from the sealing surface of the poppet to prevent the poppet from closing off the end of the groove when the poppet is in the open position.
Referring to FIG. 10, another embodiment of the valve is indicated generally at 314 with an inlet passage 316 and in outlet fitting 317 provided in the valve body 364. Body 364 defines a valving chamber 366 defining a valve seating surface 368 having formed therein a conically tapered metering passage 372 which communicates with an outlet passage 374 in fitting 317. A resilient poppet 376 is disposed for closing against surface 368 as shown in dashed outline in FIG. 10; and, the poppet is attached to a valve member 378 for movement therewith. The valve member has attached thereto a conically reverse tapered metering member 380 which has its taper corresponding to the taper of passage 372. The valve member 378 is piloted in the center of a perforated washer 388 provided in the outlet passage 374. The upper end of the valve member is piloted in a bushing insert 370. An annular permanent magnet 396 is disposed concentrically about bushing 370. A bobbin 382 which is attached to the valve member 378 and has a coil 384 wound thereon which moves with the valve member 378. Coil 384 is generally disposed concentrically about permanent magnet 396. Coil leads 300,302 extend outwardly through a passage 304 formed in the valve body. The upper end of the valve which comprises a cap 412 which is retained by screws 414. In similar manner the outlet fitting 317 is retained on the valve body by screws 410. An adjustment screw 398 extends through cap 412 and serves as a stop for the upper limit of movement of valve member 378.
The valve member 378 has a spherical lobe 379 formed thereon which slidingly engages the central bore of insert 370 to accommodate misalignment of the valve member with respect to the fitting 370. It will be understood that the spherical surface 379 is thus piloted in the insert 370. The valve member is biased downwardly with respect to FIG. 10, or towards the poppet-closed position, by a spring 390 which has its upper end registered against a ferromagnetic pole piece shaped as an annular disc 394 registered against the axial face of the magnet 396; and, the lower end of spring 390 is registered against the bobbin 382.
In the presently preferred practice, the reverse tapered metering member 380 of the embodiment of FIG. 10 has a taper angle of approximately six degrees measured with respect to the central axis. In one configuration the passage 372 has a minimum diameter at its upper end of about 3.7 millimeters and its largest diameter at the lower end of about 8.1 millimeter. In the presently preferred practice of the embodiment of FIG. 10, the tapered metering member 380 has a clearance of about 0.013 millimeters when the upper end of the rod 378 hits the end of screw 398 to limit the upward travel thereof.
Referring to FIG. 12, the values of flow in centimeters cubed per second are given for a valve tested in the configuration of FIG. 10 and having the dimensions mentioned above. The values of flow Q are plotted as a function of the movement in millimeters of the valve member 378 (throttle travel) for a supply pressure of 25 centimeters of H 2 O column. It will be seen from the graph of FIG. 12 that the poppet is fully opened at about 0.6 millimeters of travel; and, flow decreases linearly with throttle travel to a maximum travel of 4.8 millimeters. The embodiment of FIG. 10 is intended as employing a coil and magnet similar to the embodiment of FIG. 2.
The present invention thus provides a unique and relatively low-cost technique for providing remote control of an electrically operated modulating gas valve for controlling flow of gaseous fuel to a burner. The electrically operated valve of the present invention employs an electromagnetic actuator which has a preferably moveable coil and stationary permanent magnet; and, for a given current flow in the coil produces a substantially constant actuating force irrespective of the position of the actuator. This feature is a result of applying a fine wire coil having about one thousand turns disposed proximate an annular permanent magnet. The coil is preferably attached to the moveable valve member which has a poppet for closing against the valve seat to shut off gas flow; and, upon opening of the poppet a metering member attached to the valve member throttles gas flow proportionally with increasing current flow in the coil and movement of the valve member. The electromagnetic actuator produces flow metering which is substantially linear with respect to current flow in the coil and thus renders the valve capable of proportionately modulating gas flow in response to a user input from a simple potentiometer type controller.
Although the invention is capable of modification and variation by those having ordinary skill in the art, the invention is intended as limited only by the following claims.
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A method for remotely controlling flow of gaseous fuel to a burner having an electrically operated electromagnetically actuated modulating valve. The electromagnetic actuator comprises a coil having about one thousand turns of fine wire disposed proximate an annular permanent magnet. Either the magnet or coil may be attached to a moveable valve member which has a resilient poppet biased to close on a valve seat to shut off gas flow. Upon energization of the coil, a magnetomotive force is generated and moves the poppet off the seat to permit flow. Increased current flow in the coil proportionately increases opening of the poppet and movement of a metering member which throttles flow. When the poppet is fully open, flow is reduced to minimum metered level. A single user operated, remotely located potentiometer can be used to effect the proportional control of flow to the burner. In the preferred embodiment the metering member is cylindrical with a varying area grove or recess. In another embodiment, the metering member is a reversely conically tapered member throttling in a conically tapered metering passage.
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[0001] This is a Continuation of U.S. Ser. No. 12/278,734, filed 1 Jan. 2009, which is a National Stage Application of PCT/IL2007/000178, filed 8 Feb. 2007 which claims benefit of Serial. No. 173711, filed 13 Feb. 2006 in Israel which applications are incorporated by reference. To the extent appropriate, a claim of priority is made to each of the above disclosed applications.
FIELD OF THE INVENTION
[0002] The field of the invention generally relates to a method for simulating in real time, a system which comprises a plurality of sub-systems, that perform intercommunication one with the others.
BACKGROUND OF THE INVENTION
[0003] The process of developing a system which comprises plurality of sub-systems is generally very long and complicated. Several separate groups are generally assigned for separately developing each sub-system, while defining at least the following for each sub-system:
a. An input messages domain which includes all the possible input messages that the sub-system may receive, and one or more other sub-systems that can issue each of said input messages; b. The input vs. output behavior of the sub system (i.e., the product of the sub-system); and c. An output messages domain that includes all the messages that the sub-system can issue, and the addressee for each of said output messages.
[0007] During the very long process of the real system development, or more particularly, of each and all the separate real sub-systems involved, there are many occasions in which a need is arisen to test the inter-behavior of two or more subsystems, one with respect to the others. However, naturally the development of all the separate real sub-systems does not progress at the same speed, and there are many cases in which one sub-system cannot be tested until the development of another sub-system sufficiently progresses to a desired stage. Such scenarios cause many undesired delays in the system development. Moreover, even when the development of the whole system is close to the final stage, and all the sub-systems are supposed to be available for a complete system test, there are cases in which one sub-system is missing due to a sudden failure, causing the complete test to be postponed until the missing sub-system is provided.
[0008] It is therefore desired to provide a simulating system which can replace, at any time, one or more sub-systems of a real system, or alternatively, when any simulated sub-system becomes available, to easily substitute the real sub-system for the simulated one.
[0009] An example of such a system is a missile system. The missile system comprises the missile sub-system itself (which has tracking and guiding capabilities, etc.), the launcher sub-system, the control center sub-system, etc. In this case, it is sometimes necessary to carry out a partial test of the real sub-systems. For example, in order to test a real control center and a real launcher which are available, without having a missile, there is a need to substitute a real missile with a simulated missile. In another example, there may be occasions in which the launcher and the missile are unavailable while testing of the control center is necessary. In that case the simulator has to simulate both the launcher sub-system and the missile sub-system. Later, when one of said sub-systems becomes available, the simulation for this sub-system may be replaced by the real sub-system, which has just recently become available. It should be noted that it is necessary to introduce to each sub-system, either real or simulated, an external and real-time “world” as similar as possible to the real world, with as many various events and failures, as possible. For example, when testing a missile on the ground, it is necessary to provide a flight-like simulation.
[0010] Sequence diagrams are widely used in the art by engineers who define the intercommunication between the various sub-systems of a developed system. A sequence diagram describes sequentially, in terms of time, the messages that flow in the system between the various subsystems. Moreover, the issuing of at least some of the messages in the sequence diagram is conditioned, and said conditions are part of the sequence diagram. In general, the sequence diagrams are graphically described. It should be noted that each sequence diagram may comprise several sub-sequences. Sequence diagrams are well known in the art, and they can be prepared using the language UML (versions 1 and 2 are presently available).
[0011] It is therefore an object of the present invention to provide a method and tool for forming a real time simulator which is capable of simulating, either partially or completely, a real system which in turn, comprises plurality of sub-systems.
[0012] It is another object of the present invention to provide generic method and tool for designing simulators for various types of systems.
[0013] It is still another object of the present invention to enable, including in a test, a combination of the simulated and real sub systems, while enabling easy alternation between simulated and real sub-systems.
[0014] Other objects and advantages of the present invention will become apparent as the description proceeds.
SUMMARY OF THE INVENTION
[0015] The present invention relates to a method for alternately simulating sub-systems of a tested real system, comprising the steps of: (a) producing a sequence diagram defining the intercommunication of messages between the various sub-systems of the real system in terms of at least time, message name, issuing sub-system, and destination sub-system; (b) whenever there is a need to test one or more real sub-systems of the system, activating said sequence diagram, while eliminating those messages relating to existing sub-systems, and maintaining all those messages relating to missing sub-systems, said maintained messages being simulated messages for said missing sub-systems; (c) introducing in real time, and in appropriate messages format, said simulated messages on a bus leading to said real sub-systems, while further timely introducing real messages of existing real sub-systems over same bus; and (d) receiving by said sequence diagram those real messages of existing sub-systems, in order to synchronize the progression of the sequence diagram, and to satisfy conditions for issuing messages by the sequence diagram, when applicable.
[0016] Preferably, the method includes alternately replacing between corresponding real and simulated sub-systems.
[0017] Preferably, the issuing of at least some of the messages in the sequence diagram is conditional.
[0018] Preferably, the sequence diagram defines the intercommunication of messages between the various sub-systems of a full real system.
[0019] Preferably, the sequence diagram defines the intercommunication of messages between various sub-systems of a partial real system.
[0020] Preferably, the sequence diagram comprises a plurality of sub-sequences.
[0021] Preferably, the sequence diagram being divided into a plurality of sequences, each defining the intercommunication of messages between a specific sub-system and other sub-systems of a real system in terms of time, message name, issuing sub-system, and destination sub-system.
[0022] The invention also relates to a system for simulating one or more sub-systems of a tested system, which comprises: (a) a sequence diagram storage and engine unit containing a predefined sequence diagram defining the intercommunication of messages between the various sub-systems of a real system in terms of at least time, message name, issuing sub-system, and destination sub-system; (b) means for indicating to said sequence diagram storage and engine unit, those missing sub-systems, which have to be simulated; (c) means within said sequence diagram storage and engine unit for receiving activation signal for the sequence diagram, and for eliminating all those messages in the sequence diagram relating to non-missing sub-systems, while maintaining those messages relating to missing sub-systems; (d) one or more simulated sub-system units, each containing a domain of predefined output messages in appropriate format that can be issued by said simulated sub-system unit, and predefined input messages in appropriate format that can be received by said simulated sub-system unit, both said domains being essentially identical to those of the corresponding real sub-systems of the system; and (e) a real time engine for activating said sequence diagram, for receiving messages relating to missing sub-systems from one or more of said simulated sub-systems units, for introducing in real time said received messages on a bus leading to said real sub-systems, and for receiving messages issued by said real sub-systems and conveying them in real time to said simulated sub-system units.
[0023] Preferably, each real sub-system can be replaced by a simulated sub-system, by appropriately providing indication to said sequence diagram storage and engine unit.
[0024] Preferably the system enables alternately replacing between corresponding real sub-systems and simulated sub-system units.
[0025] Preferably, the issuing of at least some of the messages in the sequence diagram is conditional.
[0026] Preferably, the sequence diagram defines the intercommunication of messages between the various sub-systems of a full real system.
[0027] Preferably, the sequence diagram defines the intercommunication of messages between various sub-systems of a partial real system.
[0028] Preferably, the sequence diagram comprises a plurality of sub-sequences.
[0029] Preferably, the sequence diagram is divided into a plurality of sequences, each defining the intercommunication of messages between a specific sub-system and other sub-systems of a real system in terms of time, message name, issuing sub-system, and destination sub-system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] In the drawings:
[0031] FIG. 1 discloses a general input/output structure of plurality of sub-systems according to the prior art;
[0032] FIG. 2 , is a block diagram generally illustrating the structure of a simulation-testing system according to the present invention;
[0033] FIG. 3 generally illustrates a sequence diagram according to an embodiment of the invention;
[0034] FIG. 4 illustrates a specific case in which subsystem 1 is simulated, while sub-system 2 and sub-system 3 are tested; and
[0035] FIG. 5 provides an exemplary sequence diagram relating to a missile system.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0036] FIG. 1 generally illustrates the input/output structure of a typical real system comprising several sub-systems. The number of sub-systems within a system can, of course, vary. Each sub-system has its input domain of messages 2 , and its output domain of messages 3 . Of course, the sub-systems are somehow being connected one to the others, and there is some relation between specific input/s to some output messages, or between combinations of several input messages to an output message.
[0037] Of course, in reality the various sub-systems are somehow interconnected in a predefined manner to form the complete real system. By “interconnection” it is meant herein to wire or wireless communication, and to the types of messages that flow between the various sub-systems. However, when testing the complete system and when one or more of the sub-systems are missing, there is a need to provide substitution for the output messages of any missing sub-system. Therefore, the present invention discloses a generic method and system for providing a simulator, which can substitute for any missing sub-system of the system. Alternatively, when a missing real sub-system becomes available and needs to be tested, this real sub-system is connected to the system, and the simulator no longer simulates said previously missing sub-system.
[0038] The structure of the simulator of the present invention is generally illustrated in FIG. 2 . The “real world” is illustrated at the right side of dotted line 10 , and the “simulated world” is illustrated at the left side of dotted line 10 . In the best case, when all the real sub-systems 1 , 2 , and 3 are available, there is essentially no need for the simulator 100 shown at the left side of dotted line 10 , as all the sub-systems can communicate one with the others, in a normal manner by means of bus 5 . However, when for any reason, one or more of the sub-systems 1 , 2 , or 3 , becomes unavailable, and the rest of the system has to be tested, the simulator 100 substitutes, for each missing sub-system, one or more corresponding simulated sub-system units 101 , 102 , and 103 . In that case, the testing of the rest of the real system 50 can be carried out as is necessary. The simulator 100 provides via bus 5 a into bus 5 the substituted messages for the missing, now substituted sub-systems.
[0039] The structure of simulator 100 will now be described. At a first stage, the domain of all possible output messages are defined separately for each simulated sub-system unit 101 , 102 , and 103 . Furthermore, a domain of all possible input messages that each unit can receive, is also defined respectively for each simulated sub-system unit. Said input and output domains of messages are stored correspondingly in said simulated sub-system units. At a next stage, a sequence diagram for the whole system is defined and stored in sequence diagram engine 105 . The sequence diagram defines the sequence, times, specific messages and, optionally, conditions for issuing each message by sub-system units 101 , 102 , and 103 , during the simulated activity.
[0040] As said, sequence diagrams are well known in the art, and they can be prepared using the language UML (versions 1 and 2 are presently available).
[0041] An example for a sequence diagram for a simple system having five subsystems (indicated as Sub 1 -Sub 5 ) is shown in FIG. 3 . The vertical dimension of the sequence diagram represents time. The horizontal dimension represents the message exchange between the various sub-systems. The dotted line under each sub-system represents the lifeline of the sub-system (i.e., the duration in which the sub-system is in standby or active state), and the vertical boxes under the various subsystems represent durations in which the sub-systems are active. The messages themselves are symbolized by their corresponding name. For example, message Out 2,4 indicates an output message of type 4 which is issued by sub-system 2 . In this case, message Out 2,4 is issued by sub-system 2 , and is conveyed to sub-system 1 . It should be noted that, optionally, the issuing of some of the messages may be conditioned. For example, message Out 3,1 may be designed to be issued by sub-system 3 only after a delay of 2 seconds from the receipt of message Out 2,1 at sub-system 3 . Various types of other conditions may be applied. It should be noted that the sequence diagram generally comprises several, in some complicated cases many, sub-sequences, each of which may have the general form of the sequence of FIG. 3 . The actual activation of the various sub-sequences may be conditional in terms of occurrence of events as defined.
[0042] Such sequence diagrams have been generally used by engineers in the art, either for only displaying the sequence, or for the purpose of providing a unified software simulation. Moreover, never in the prior art has it been proposed to enable using the sequence diagram of the full system to simulate alternately for missing and real sub-systems, as in the present invention.
[0043] Having the sequence diagram of the full system and the domains containing all the possible messages for each sub-system, the simulator is essentially ready for operation. With reference again to FIG. 2 , when one or more of the real sub-systems 1 , 2 , or 3 is missing, the real time engine 115 provides corresponding indications 111 , 112 , or 113 indicating to the sequence diagrams storage and engine unit 105 , which sub-system portions of the sequence diagram to maintain, and which to ignore. The activated portions of the sequence diagram are those relating to the one or more missing sub-systems, and those portions that are ignored, relate to existing real sub-systems that do not have to be simulated.
[0044] Then, when the sequence diagram is activated and run by the engine 105 , the engine timely conveys messages of only the missing (and now simulated) sub-systems to the corresponding one or more simulated sub-system units 101 , 102 , or 103 . Said one or more simulated sub-system units issue in real time from among their domain of output messages, corresponding simulated messages, which have an appropriate format for introduction on bus 5 . Said simulated messages have the same format, and essentially same timing as would otherwise be issued by a missing real sub-system. The simulated messages are then introduced by real-time engine 115 over bus 5 a , which in turn introduces the message on bus 5 . In such a manner, the existing one or more real sub-systems in the “real world” receive simulated messages, having same format and timing, as would otherwise be conveyed to them by a real (now missing) sub-system. Therefore, in such a manner, the existing real sub-systems can be tested.
[0045] Furthermore, as said, the issuance of some of the sequence diagram messages is conditional in terms of the occurrence, or receipt of one or more messages from a real sub-system 1 , 2 , or 3 . Therefore, said real messages, as issued by real sub-systems 1 , 2 , or 3 and introduced on bus 5 , are conveyed via bus 5 a into the real time engine 115 , which in turn conveys in real time each message to a corresponding simulated sub-system unit 101 , 102 , or 103 , which in turn conveys said message to the sequence diagram engine 105 , notifying it about the issuance of said real message by a real sub-system. In such a manner the sequence diagram within sequence diagram engine is synchronized about all messages issued in the “real world”, and it can also satisfy all its conditions which depend on messages from real sub-systems in the “real world.
[0046] It should be noted that that the sequence diagram engine 105 , when operated, indicates respectively to each simulated sub-system unit 101 , 102 , and 103 , which message from its domain of messages to issue, and when to issue said message. Furthermore, the sequence diagram engine 105 indicates to each simulated sub-system unit 101 , 102 , and 103 , and appropriate times to which real message to wait.
[0047] Later on, when, for example, one of the missing real sub-systems becomes available, and is introduced at the “real world” portion of the system, real time engine 115 updates the sequence diagram storage and engine unit 105 accordingly, by an updated corresponding message 111 - 113 , and the simulator 100 operates in an updated form, ceasing simulation of the newly introduced sub-system.
[0048] FIG. 4 illustrates an exemplary case in which real sub-system 1 is missing, while real sub-system 2 and real sub-system 3 are available, and have to be tested. In that case, the real time engine 115 issues indication 111 into sequence diagrams storage and engine unit 105 indicating it to activate the sequence diagram, while ignoring (or eliminating the appearance of) the messages within the sequence diagram relating to the existing sub-system 2 , and sub-system 3 . Then, the sequence diagram messages relating to the real sub-system 1 are conveyed into the simulated sub-system unit 101 , which issues in real time corresponding messages in appropriate format, that are conveyed into real-time engine 115 , which in turn introduces them into bus 5 a , which in turn introduces them on bus 5 , which in turn conveys them correspondingly into the tested real systems 2 and 3 . Furthermore, real messages that are issued by the available real sub-systems 2 and 3 , respectively, are conveyed via bus 5 , bus 5 a , the real time engine 115 , and corresponding simulated subsystem units 102 , or 103 respectively, into the sequence diagram engine 105 , to synchronize it, and to satisfy conditional issuance of messages.
[0049] It should be noted that the sequence diagram essentially defines the behavior of the whole system, as it describes the sequence, timing, and specific messages that will be issued by its various sub-systems. Selection from the sequence diagram of only the messages relating to the missing sub-systems enables simulation of only said sub-system. Of course, there may be cases that several sub-systems have to be simulated simultaneously. In such a case, selection of more corresponding portions from the sequence diagram will be made. Therefore, the corresponding several missing sub-systems will be simultaneously simulated. It should be noted that FIGS. 2 and 4 includes 3 sub-systems only for the purpose of illustration. The system may include any number of sub-systems essentially in a same manner. Furthermore, it should be noted that the sequence diagram does not necessarily have to be unified and relate to the whole system as shown in FIGS. 3 and 5 discussed above, and it may be divided into several discreet sequence diagrams, each relating to one or several sub-systems.
Example
[0050] FIG. 5 illustrates an exemplary simplified sequence diagram for a missile system, which can be used according to the present invention. The sequence diagram was produced using UML2 language. The missile system comprises one user (an Attack Commander) and three sub-systems, as follows: a Control Center, a Launcher, and a Missile. Each of the above sub-systems and even the user can be simulated, while testing the other real sub-systems. As said, only the messages of missing sub-systems are issued and thereafter conveyed to the “real world”, while all the others messages relating to existing and tested sub-systems are eliminated. Now, assuming that the Control Center and Missile are real, while the Launcher is simulated, the operation is as follows: The operation of the system begins by issuing a “Prepare” message by the real Control Center sub-system to the simulated Launcher sub-system unit. This issuing of said message depends (i.e., conditioned) on a false status of the message “Missile Ready”, and this status is checked every 100 ms. The simulated Launcher sub-system unit, which was previously set by the sequence diagram engine to wait for said message, and upon receipt of said message conveys a “Msl_Prepare” message to the real Missile sub-system. Receiving said message, the real Missile sub-system, which has been waiting for said message, begins preparation, and when ready, it issues a message “Msl_Ready” which is conveyed to the simulated Launcher sub-system unit. The Launcher sub-system unit, which was previously set by the sequence diagram engine to wait for the message “Msl_Ready” (from the real Missile), in turn issues and conveys a message “Ready_to_Launch” to the real Control Center, which in turn issues and conveys a message “Msl Ready” to the Attack Commander (the user).
[0051] Then, the Attack Commander issues and conveys to the real Control Center a “Launch” message, which in turn issues a message “Launch” to the simulated Launcher sub-system unit (which was previously set by the sequence diagram to wait for this message). Upon receipt of said “Launch” message, the simulated Launcher sub-system unit issues a “Launch_Msl” message to the real Missile.
[0052] As said, according to the present invention, and having said sequence diagram, each one or more of the above sub-systems can alternatively be simulated or tested.
[0053] While some embodiments of the invention have been described by way of illustration, it will be apparent that the invention can be carried into practice with many modifications, variations and adaptations, and with the use of numerous equivalents or alternative solutions that are within the scope of persons skilled in the art, without departing from the spirit of the invention or exceeding the scope of the claims.
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System for simulating sub-systems of a tested system includes: (a) a sequence diagram storage defining the intercommunication of messages between various sub-systems of a real system; (b) an indicator for the sequence diagram those missing sub-systems, which have to be simulated; (c) a receiver within the sequence diagram for receiving activation signal for the sequence diagram, and for maintaining only those messages relating to missing sub-systems. The system also includes (d) one or more simulated sub-system units, each containing a domain of predefined output and input messages; and (e) a real time engine for activating said sequence diagram, receiving messages relating to missing sub-systems from the simulated sub-systems units, introducing in real time the received messages on a bus leading to the real sub-systems, and receiving messages issued by the real sub-systems and conveying them in real time to the simulated sub-system units.
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RELATED APPLICATIONS
This application is a division of application Ser. No. 11/278,415, filed Apr. 1, 2006, and is hereby incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates to the field of construction and home improvement, and more specifically to equipment for restraining containers of paint, sealant, other materials or tools.
BACKGROUND
It is sometimes necessary to apply paint or sealant while on an inclined roof or other surface. In these situations it is preferable to have an apparatus to hold the container containing the material being applied. Furthermore, it is more convenient and productive to apply paint or sealant directly from a five gallon bucket, rather than from a pan. Alternately, it is sometimes necessary to provide a container for tools and/or materials while working on an inclined roof or other surface. This requires a method of restraining a heavy bucket and current mechanisms for holding containers on inclined surfaces are limited.
A number of mechanisms have been proposed to hold paint cans or buckets on sloped roofs. For example, U.S. Pat. No. 4,962,906 discloses a paint can holder for supporting a can in an upright position on a sloped surface. This device can only accommodate a single can having a specific size of handle bosses. U.S. Pat. No. 5,217,193 also discloses a paint can holder for an inclined roof. This device requires manual adjustment for accommodating the slope of the roof. Similarly, U.S. Pat. No. 6,533,227 discloses an apparatus that attaches to a can and can be used to hold a can in an upright position if adjusted according to the slope of the roof. None of these three patents incorporate a flat level working surface. Such a surface is useful, for example, for striking a paint roller to reposition the roller on its handle (a frequent problem with paint rollers).
U.S. Pat. No. 5,249,397 discloses a platform that can be used to create a flat surface by manually adjusting the legs to accommodate the slope of the roof. This device does not restrain a can or bucket, but only creates a flat surface if properly adjusted. U.S. Pat. No. 5,558,306 discloses a platform incorporating a paint can holder for use on a sloped roof. This device requires manual adjustment according to the slope of the roof. U.S. Pat. No. 5,193,773 also discloses a bucket holding apparatus incorporating a device that attaches to the crest of a roof and a cable attached platform for holding a paint can. This device is complex and cumbersome to operate. It also does not have a flat level surface.
None of the six patents discussed in the preceding two paragraphs position a container above the crest of a roof or provide the simplicity of a single piece construction.
Accordingly, the need exists for an improved container restraining system that doesn't have the limitations of the mechanisms described above. What is needed is a simple and inexpensive apparatus for holding containers at the crest of a roof and also that can easily accommodate roofs of differing pitches.
BRIEF SUMMARY OF THE INVENTION
The present invention addresses the shortcomings described above by providing a simple stackable one-piece container restraining system incorporating a flat top surface and four legs. In one aspect of the present invention, a mechanism is provided to attach the container to the flat top surface of the apparatus. In another aspect of the present invention, mounting holes are provided on the legs to allow the attachment of various fixtures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an embodiment of the present invention.
FIG. 2 illustrates an embodiment of the present invention with a bucket inserted therein and situated on the crest of a roof.
FIG. 3 illustrates three instances of an embodiment of the present invention stacked with a bucket inserted therein.
DETAILED DESCRIPTION
The restraining system of the present invention can be used on the crest of a roof and the apparatus can be stacked for stability and/or to accommodate roofs of differing pitches. This stacking feature can also elevate a large bucket of paint, tools, materials, etc to working height of one or more workers while standing on a flat level surface.
FIG. 1 illustrates an embodiment of the present invention 10 , in which top surface 12 is connected to four legs 16 . Container restraining apparatus 10 has a hole 17 which is designed to accommodate a container of a specific size and shape. In a preferred embodiment hole 17 accommodates a standard size five gallon bucket, which has tapered sides and several exterior circumferential rings at the top. A standard five gallon bucket available in the United States measures approximately 10½ inches diameter at the bottom and approximately 11¾ inches diameter at the top. A hole of approximately 11 5/16 inches allows the tapered bucket to fit snugly in the restraining apparatus and the bucket will fit such that the flat surface 12 is at the level of the lowest ring 38 . Those of skill in the art will appreciate that the present invention can be used with containers of other dimensions, and with either straight or tapered sides.
In one embodiment of the present invention, each leg 16 of container restraining apparatus 10 has a notch 14 which forms an indentation such that one instance of apparatus 10 can be stacked on top of another instance of apparatus 10 . Those of skill in the art will appreciate that there are alternative designs having the stackable feature.
In one embodiment of the present invention, container restraining apparatus 10 also incorporates holes 19 which can be used to attach a container to the top surface 12 . For example, a standard cable tie can be used through holes 19 and around the handle of the container. The attachment of the container to top surface 12 allows one to lift a container along with the container restraining apparatus 10 together by lifting only the container, for example by its handle. This permits easy movement of the container and restraining apparatus across the work surface. When several restraining apparatus 10 are stacked, alignment of holes 19 can be such that all apparatus in the stack are attached to the container to facilitate lifting the stack via the container handle. Alternately holes similar to 19 can be appropriately placed to accommodate attachment of quick-release locking devices to facilitate ease of attachment/detachment of apparatus 10 and bucket 24 . It will be appreciated to those of skill in the art that alternative methods of attaching the container to the flat top surface 12 can be employed and fall within the scope of the invention.
In a preferred embodiment, each leg 16 has a mounting hole 37 at the foot of the leg for mounting of wheels, soft plastic/rubber inserts, articulating flat pads, spikes, or other devices for the purpose of providing mobility and/or to better accommodate a variety of work surface conditions. The mounting hole 37 of each leg can also be used to secure container restraining apparatus 10 to a flat surface such as a truck bed, plywood platform, etc. using standard bolts or screws.
Container restraining apparatus is preferably built from one piece of material, for example injection molded plastic. This method of manufacture permits the restraining apparatus to be inexpensively produced with high quality and consistent results. The apparatus of the present invention can be built by cutting a hole in an existing injection molded table, or an injection mold can be built that incorporates the hole. An example of a table into which a hole can be cut to manufacture the apparatus is illustrated in U.S. Pat. No. Design 335,980.
In a preferred embodiment the top surface 10 is substantially square, wherein the dimension between each pair of legs is substantially the same. In an alternative embodiment, restraining apparatus 10 is substantially rectangular in shape with one side longer than another. In this embodiment, the apparatus can be placed in two different orientations across the crest of a roof. Placing the apparatus such that the shorter dimension is across the crest of the roof allows for a greater clearance between the bottom of the container and the crest of the roof. This orientation may be necessary in highly pitched roofs. Alternatively, multiple apparatuses may be stacked to accommodate highly pitched roofs as discussed below.
FIG. 2 illustrates an embodiment of the present invention situated on the crest of a roof. Container restraining apparatus 10 is situated on roof 26 and is holding five gallon bucket 24 , which contains paint roller 22 . FIG. 2 illustrates an attachment apparatus 28 that utilizes holes 19 to attach bucket 24 to the restraining apparatus if desired. In an alternative embodiment, restraining apparatus 10 can be fitted with either two or four wheels mounted under the legs. For example, two legs may have wheels and two legs may have articulating flat pads. The use of wheels permits the apparatus to be conveniently moved across the crest of the roof as work progresses. While FIG. 2 is shown in reference to the application of liquid material using a paint roller, the present invention can also be used to hold tools and materials. For example, an embodiment of the present invention can be used by roofers as a secure container for holding roofing tools, nails, staples, etc.
FIG. 3 illustrates the stackable feature of an embodiment of the present invention. Restraining apparatus 30 is stacked on top of apparatus 32 which is stacked on top of apparatus 34 . Bucket 36 is inserted into the collective apparatus consisting of 30 , 32 and 34 . Stacking the restraining apparatuses 30 , 32 and 34 accomplishes three important goals: first, it raises the height of the bottom of the container, allowing the combined apparatus to be used on a roof of high pitch, second, it creates a more stable combined apparatus due to the mutual reinforcement of the legs of each individual apparatus, and third, it provides for efficient storage of multiple restraining apparatuses.
An example of the use of the present invention involves a modification to a standard five gallon bucket to incorporate a valve at the bottom of the bucket. This modification may require the use of multiple stacked restraining apparatuses to elevate the height of the bucket to permit clearance of the valve. The valve and the position of the apparatus at the crest of a roof permits liquids contained in bucket 24 to be held at a position higher than the application surface. Thus, if bucket 24 is modified to accommodate such a valve, liquid materials to be distributed via application devices such as self loading paint rollers, brushes, mops, etc. can work more efficiently due to differential static pressure when the application device is operated closer to ground level than the level of fluid in bucket 24 .
In one embodiment of the present invention, the flat top surface is substantially rectangular. In another embodiment of the present invention, the flat top surface is substantially circular.
Some embodiments of the present invention have a mounting hole at the bottom of each of the legs. In an embodiment of the present invention, two wheels are attached to two of the legs using two of the mounting holes. In another embodiment of the present invention, four wheels are attached to the four legs using the mounting holes. In another embodiment of the present invention, two articulating flat pads are attached to two of the legs using two of the mounting holes. In another embodiment of the present invention, four articulating flat pads are attached to the four legs using the mounting holes. In another embodiment of the present invention, two wheels are attached to two of the legs using two of the mounting holes, and two articulating flat pads are attached to two of the legs using two of the mounting holes.
The present invention has been described above in connection with several preferred embodiments. This has been done for purposes of illustration only, and variations of the inventions will be readily apparent to those skilled in the art and also fall within the scope of the invention.
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A one-piece stackable container restraining apparatus incorporates a flat surface and four legs. The restraining apparatus can be used on the crest of a roof or on other surfaces. The stackable feature is used to accommodate roofs of differing pitches and to create a more stable combination. In certain embodiments attachment holes are utilized for ease in transportation and movement. Additionally, the container restraining apparatus can be used on a flat surface to prevent overturning of the container during transportation, such as paint buckets transported in a truck or van. Mounting holes on each leg can be used to accommodate a variety of fixtures such as wheels or articulating pads.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International Application No. PCT/EP00/06889, filed Jul. 19, 2000, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The invention is directed to an apparatus for holding and dispensing metered amounts of at least one active composition into a washing machine, a laundry dryer or a dishwashing machine.
[0003] Already known from German published patent application DE 197 40 819 A1 is a metering and dispensing device inside a mechanism designed to add powdered detergent in doses to water-operated washing machines. The device is provided with two compartments disposed in one plane for receiving the powdered detergent, which is discharged into a processing container of the washing machine. The compartments have filling openings, through which any individual or all of the compartments can be selectively filled with the powdered detergent. The filling openings communicate with an outlet opening of a funnel-shaped detergent hopper mechanism and simultaneously serve as individually activatable openings for the purpose of dispensing to the rinsing or washing water, co-operating with synchronously controllable outlet openings for the water admixed with the powdered detergent. The individual doses of detergent are discharged by a manual setting operated by the user or by an operating program selected by the user.
[0004] U.S. Pat. No. 4,379,515 discloses a dispensing device for detergent, comprising a rigid container and, communicating with this rigid container by means of a pipe, a compressible reservoir containing the measured quantity of detergent needed for one washing cycle. Under the effect of centrifugal forces generated by rotation of the laundry drum, the reservoir is compressed—particularly if it is disposed between the laundry and the wall of the laundry drum—in such a way that its contents are emptied into the rigid container, where the detergent is then dissolved by the washing liquor. A disadvantage of this dispensing system resides in the fact that the reservoir can be used for only one respective washing cycle and has to be replaced with each new washing cycle.
[0005] European patent publication EP 0 215 366 describes a detergent container with a welded seal, wherein the welded seal melts at a specific operating temperature and then releases the detergent. The seal of the container in particular cannot be used again and, in addition, it is not possible to dispense more than once with this system.
[0006] European patent publication EP 0 328 769 describes a removable dispensing container with a closure that can be opened during a washing cycle and which has a manipulating extension. The pressure exerted by the laundry during the washing cycle causes the manipulating extension to be pushed into the dispensing container in such a way that the detergent is able to flow out. It is not possible to dispense more than one dose, and the dispensing container must be filled again before each washing cycle.
[0007] German patent publication DE 39 02 356 discloses a dispensing container which may be used for a single washing cycle only and operates on the basis of a temperature-dependent release of a liquid fabric conditioner. The rising temperature causes the pressure in the dispensing container to rise above atmospheric pressure, as a result of which a gate valve is displaced into its open position, permitting the liquid fabric conditioner to flow into the washing machine.
[0008] U.S. Pat. No. 5,033,643 describes a dispensing container, which also allows a metering unit to be released for only one washing cycle. Forces generated by the wet laundry act on the release mechanism of the dispensing container.
[0009] German patent publications DE 39 34 123 and DE 39 22 342 describe detergent containers which are fixedly mounted on the laundry drum. Pins or locking hooks are used for fixing purposes. With these containers, no provision is made for more than one dose, which means that they have to be removed from the washing machine after every washing cycle and re-filled.
[0010] U.S. Pat. No. 5,176,297 describes a dispensing system for a dishwasher, which is mounted in the interior of the machine and incorporates a supply and a dispensing compartment. Although it is possible to dispense more than one dose, the dispensing system is controlled by the dishwasher in a complex manner.
[0011] German patent publication DE 195 40 608 discloses a system enabling more than one dose to be dispensed, in which tablets of dishwasher detergent are placed. The individual doses are controlled by a command issued by the dishwasher, i.e. an operating program of the dishwasher selected by the user controls the time at which the dose is released.
[0012] Australian published patent application AU-A-78393/91 discloses a dispensing container for a detergent, which is dispensed through an orifice opened by the build-up of internal pressure in the container. This internal pressure is generated either by the operating program of the machine or by operation directly on the part of the user.
[0013] Summing up the state of the art, dispensing systems are known which primarily permit individual doses to be dispensed and in a few cases multiple doses. In systems permitting a single dose, the release of detergent is generally operated on the basis of a delayed release, which may be triggered by means of a rise in temperature, an increase in pressure or centrifugal forces, for example. What systems permitting multiple doses have in common is that the release is mechanically triggered (valve, piston, gate, etc.), either on the basis of a command issued by the washing program of the machine or by direct operation on the part of the user.
BRIEF SUMMARY OF THE INVENTION
[0014] An underlying objective of the invention is to propose an apparatus for holding and dispensing doses of at least one active composition into a washing machine, a laundry dryer or a dishwasher. The apparatus enables more than one dose to be dispensed (in either one or more laundry washing, drying or dishwasher rinse cycles) and is triggered independently of the commands of an operating program in the machine or intervention by the user.
[0015] This objective is achieved by the invention in that at least two separate compartments are provided for respectively receiving and dispensing at least one active composition. An opening mechanism is provided for the compartments, which is operated by means that are activated by conditions prevailing in the interior of the machine, which occur exclusively during a laundry washing, drying or dish-washing cycle. For this purpose, the position of the opening mechanism and/or the compartment(s) relative to one another is altered after at least one respective compartment has been emptied, thereby enabling at least one other respective compartment to be opened by the opening mechanism when activated again.
[0016] A preferred embodiment is wherein a first bellows; a second bellows; a connecting pipe with a one-way valve which connects the two bellows to one another; and a hydraulic fluid which is released from the first bellows into the second bellows causing the latter to expand. The opening mechanism is connected to the second bellows in such a way that it is raised due to the expansion of the second bellows, the opening mechanism being so designed that its lifting action causes the compartment(s) to open to the degree that the compartment contents can be substantially entirely dispensed into the machine. This embodiment also includes means which enable the hydraulic fluid gradually to leave the second bellows and a return mechanism connected to the opening mechanism, which enables the opening mechanism to be repositioned as the hydraulic fluid gradually leaves the second bellows, the opening mechanism being guided into a position such that, when activated again, the or other compartment(s) can be opened in the same manner.
[0017] In accordance with the invention, the release of hydraulic fluid from the first bellows to the second bellows is operated, directly or indirectly, by rotation of the apparatus with the washing machine or dryer drum. In one especially preferred embodiment of the invention, as the apparatus is rotated with the washing machine or dryer drum, a pivotably secured weight compresses the first bellows, causing the hydraulic fluid to be released to the second bellows. In an alternative embodiment of the invention, the hydraulic fluid is released from the first bellows to the second bellows due to the wet laundry or dry laundry compressing the first bellows directly or indirectly.
[0018] Another embodiment of the invention is characterized in that the opening mechanism is raised, directly or indirectly, by means which are altered in form, at least to a certain degree, when the temperature is increased, until at least one compartment has been opened wide enough for the compartment contents to be essentially entirely released into the machine. The means undergo the reverse change of form, at least to a certain degree, on cooling, so that the opening mechanism is guided into a position from which the or other compartment(s) can be opened in the same manner when activated again.
[0019] An alternative to this embodiment of the invention is characterized by a rigid compartment with a material disposed therein, which expands as the temperature increases and shrinks on cooling, in particular a wax. Preferably, the opening mechanism is raised by means of a flexible diaphragm, which responds to the expansion of the material. Another alternative to the embodiment of this invention which reacts to the effect of temperature is wherein a bimetallic strip, which bends when the temperature increases and returns to shape on cooling.
[0020] Particularly preferably, the opening mechanism is guided into its new position by means of a key groove and a nose co-operating therewith. The opening mechanism preferably has at least one blade or a tongue.
[0021] In one particularly practical arrangement, the apparatus is firmly but detachably secured in the interior of the machine. Preferably, the apparatus comprises a cartridge with four to fifteen, more preferably ten, compartments, the compartments preferably being laid out in a circular arrangement in the cartridge.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0022] The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:
[0023] [0023]FIG. 1 is a vertical cross sectional view through one embodiment of an apparatus proposed by the invention in a non-dispensing state;
[0024] [0024]FIG. 2 is a view similar to FIG. 1 showing the apparatus in a dispensing state;
[0025] [0025]FIG. 3 is a plan view of an embodiment of an apparatus proposed by the invention;
[0026] [0026]FIG. 4 is a vertical cross sectional view of another embodiment of an apparatus proposed by the invention;
[0027] [0027]FIG. 5 is a plan view in of another embodiment of an apparatus proposed by the invention;
[0028] [0028]FIG. 6 is a vertical cross sectional view of yet another embodiment of an apparatus proposed by the invention, shown in a non-dispensing state;
[0029] [0029]FIG. 7 is a view similar to FIG. 6 showing the apparatus in a dispensing state; and
[0030] [0030]FIG. 8 is an enlarged, exploded, perspective view of the mechanism of the rotating blade for opening the individual compartments.
DETAILED DESCRIPTION OF THE INVENTION
[0031] Turning more specifically to FIGS. 1 and 2, an apparatus as proposed by the invention comprises a base plate 1 , which is securely (but detachably) fastened in the machine by a holder (e.g., locking hooks or expanding pins, not shown), e.g., on the inside wall 3 of a laundry drum, and a cartridge 4 comprising, for example, ten compartments 5 for receiving at least one active composition. The base plate 1 additionally has a pivotably mounted release mechanism 6 and a rotating opening mechanism 7 for opening the individual compartments. The compartments 5 in the cartridge 4 are arranged in a circle (FIG. 3).
[0032] With the embodiment illustrated in FIGS. 1 and 2, wet laundry or dry laundry exerts pressure on the release mechanism 6 , in particular due to the rotation of the washing machine or dryer drum. As a result, a first bellows 8 disposed underneath is compressed and the hydraulic fluid 9 (preferably water) disposed in the bellows is released through a connecting pipe 10 to a second bellows 11 . As this happens, the hydraulic fluid 9 flows through a one-way valve 12 , which prevents the fluid from flowing back out of the second bellows 11 . As the bellows 8 is compressed, the second bellows 11 expands in stages.
[0033] In an alternative embodiment (FIG. 4), the rotation of the washing machine or dryer drum pushes a pivotably suspended weight 18 against the first bellows 8 , thereby causing the hydraulic fluid 9 disposed in the first bellows to be released into the second bellows 11 in the same manner.
[0034] As it expands, the second bellows 11 raises an opening mechanism 7 with a blade or a tongue 13 , which then damages a compartment 5 containing an individual dose of active composition in such a way that it is torn open and its contents are released into the machine. The important factor is that the material encasing the compartment should be of an appropriate type which can be opened by the blade or tongue 13 . This encasing material (e.g., thin plastic film) should therefore be easy to puncture or pierce.
[0035] It goes without saying that the opening mechanism 7 may also be designed so that it has more than one blade or tongue 13 in order to damage and hence open either one compartment at several points or several compartments simultaneously. The latter situation would enable different active compositions contained in different compartments to be dispensed simultaneously or allow incompatible components to be kept separate from one another.
[0036] Once the compartment has been emptied, the hydraulic fluid 9 is slowly able to flow out of the second bellows 11 through a small orifice 14 , causing the opening mechanism to be lowered by means of a return spring 15 and at the same time placed by means of a zig-zag mechanism, comprising a key groove 16 and a nose 17 co-operating therewith (FIG. 8), in a position from which one or several other compartment(s) 5 may be opened on re-activation. Once all compartments 5 of the cartridge 4 are spent, the latter can be easily replaced by a new one.
[0037] In one embodiment of the invention, the opening mechanism can be re-positioned by dimensioning the orifice 14 or return force of the spring 15 in such a manner that this repositioning action does not take place until completion of the laundry washing, drying or dish-washing cycle, i.e., only one respective compartment is opened during a cycle. In this embodiment, the compartments usually contain the same active composition and do so in a respective amount specifically measured for one cycle.
[0038] In another embodiment of the invention, consecutive compartments 5 of the cartridge 4 are filled with different compositions and are opened one after the other during a cycle. For example, a first compartment might be filled with a detergent for the main washing cycle of a washing machine, and a subsequent compartment might be filled with a fabric conditioner for a rinsing cycle.
[0039] In this embodiment, the dimensioning of the orifice 14 and the return force of the spring 15 must be selected so that the opening mechanism is repositioned on completion of the main washing cycle to enable renewed activation during the rinsing cycle. It would also be conceivable to cause several activations during one phase of the laundry washing, drying or dish-washing cycle, provided steps are taken to ensure that the hydraulic fluid can flow back out of the bellows 11 relatively quickly, in order to ensure that the opening mechanism can be activated rapidly again.
[0040] If the cartridge 4 contains several compartments with different compositions, which are to be released during a single laundry washing, drying or dishwashing cycle, these compartments need not necessarily be of the same size. Accordingly, the compartments may be designed as illustrated in FIG. 5. The mechanism for guiding the opening mechanism 7 , such as the aforementioned zig-zag mechanism, may also be designed so that the opening mechanism 7 is guided into the correct respective position for opening the next compartment even if the compartments 5 are of a different design. If a cartridge incorporates compartments with different compositions intended to be released within one cycle, steps must be taken (for example by means of an indentation or the like) to ensure that the cartridge 4 is always attached to the base plate 1 in the correct position from which the dispensing sequence will be correctly timed.
[0041] In another embodiment of the invention (illustrated in FIGS. 6 and 7), the system is activated depending on temperature. To this end, a rigid compartment 20 is disposed underneath the opening mechanism 7 and contains a material 21 , such as a wax, which expands when the temperature increases. When the laundry washing or dishwashing water or interior of the dryer is heated to the desired operating temperature, the wax 21 expands and pushes the opening mechanism 7 upwards, either directly or indirectly via a flexible diaphragm 22 . In the same way as described with reference to the embodiment illustrated in FIGS. 1 and 2, this enables the opening mechanism 7 to open at least one of the respective compartments 5 , e.g., by means of a blade or tongue 13 . As the wax 21 cools, the opening mechanism 7 is duly lowered and is moved into the next position, for example by means of a zig-zag mechanism as described above. For the sake of simplification, this mechanism is not illustrated in the schematic diagrams of FIGS. 6 and 7. The described temperature-dependent system is particularly well suited for use in a dryer if it is desirable for the release of the compartment contents to be delayed or in a dishwasher which does not have a rotating drum.
[0042] In an alternative embodiment (which is not illustrated), the system may also be activated on the basis of temperature by providing a bimetallic strip, which bends as the temperature increases, thereby directly or indirectly raising the opening mechanism in the same manner as the wax 21 described above. On cooling, the bimetallic strip likewise returns to its initial shape so that the opening mechanism can be guided into its new position.
[0043] In the case of dishwashers, the temperature is normally increased twice during a dishwashing cycle, namely once during the cleaning cycle and a second time during the rinsing cycle. The temperature-dependent embodiments of the system proposed by the invention would therefore be activated twice, i.e., an appropriate substance would be released into the dishwasher twice. This might be a rinsing agent in both cases. However, it would also be conceivable, as an alternative, to provide one compartment with a dishwashing detergent and one with a rinsing agent, so that the dishwashing detergent is dispensed during the washing cycle and the rinsing agent during the rinsing cycle.
[0044] It goes without saying that within the scope of the invention, other embodiments would also be conceivable. For example, instead of breaking the encasing material by means of a blade or tongue, it would be conceivable for the opening mechanism simply to press against a perforation that would tear under the effect of this pressure. This being the case, a stronger material could be used for the material encasing the compartment.
[0045] The described zig-zag mechanism of FIG. 8, where a nose 17 is guided in a key groove 16 of matching design as the opening mechanism is being raised and lowered into a position enabling the individual compartments of the apparatus to be opened, is also given solely by way of example, and a person skilled in this art would have no difficulty in finding other means that would fulfil the same purpose.
[0046] As an alternative, the invention also proposes that, instead of moving the actual opening mechanism (for example by means of the zig-zag mechanism illustrated in FIG. 8), it would be possible to move the compartments 5 , by rotating the cartridge 4 for example, to permit another compartment to be opened by the opening mechanism 7 , which would be stationary in this situation. Clearly, it would also be conceivable to displace both the opening mechanism 7 and the compartments 5 in order to move the opening mechanism 7 and the next compartment 5 to be opened into the correct position relative to one another.
[0047] The active composition(s) contained in the compartments may be of different types. In a laundry washing machine application, the compartments might contain detergent, water softener, fabric conditioner, etc., individually or in combination. In the case of dryers, it would be conceivable to use specific substances for impregnating and/or conditioning fabrics, for example. For dishwasher applications, dishwashing additives and rinsing agents could be used in particular.
[0048] Clearly, the active compositions contained in the compartments are not restricted to liquids. The compartments could also contain a pasty, granular or powdered material or alternatively a composition in tablet format. When the material encasing the compartments is torn, laundry washing or dishwashing liquid (at least in washing machine or dishwasher applications) would then penetrate the compartment and dissolve or rinse out the composition disposed in it. This could have an additional advantage over liquids since the contents could be released on a delayed basis.
[0049] It is of advantage to provide means for inactivating the apparatus, preferably of the type which do not have to be removed from the machine, so that the user can decide whether to run the machine with the apparatus proposed by the invention in the activated state or in the non-activated state. Any type of locking mechanism that would prevent the opening mechanism 7 from being raised could be used for this purpose, preferably a system of locking the release mechanism 6 or the cartridge 4 .
[0050] The features of the invention disclosed in the above description, the drawings and the claims may be construed as essential to the realization of the invention in its various embodiments, both individually and in any combination.
[0051] It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.
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An apparatus for holding and dispensing metered doses of at least one active composition in a washing machine, a dryer or a dishwasher has at least two separate compartments for respectively receiving and dispensing an active composition and an opening mechanism for the compartments, which is operated by means which are activated by conditions prevailing in the inside of the machine. These conditions prevail solely in the course of a washing, drying or dishwashing cycle. The position of the opening mechanism and/or the compartment(s) after emptying of at least one compartment is changed relative to each other, such that the opening mechanism can then open at least one other compartment, when another activation occurs.
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FIELD OF THE INVENTION
[0001] The invention relates generally to providing active cooling for a reductant delivery unit for an automotive selective catalytic reduction system.
BACKGROUND OF THE INVENTION
[0002] New emissions legislation in Europe and North America is driving the implementation of new exhaust aftertreatment systems, particularly for lean-burn technologies such as compression-ignition (diesel) engines, and stratified-charge spark-ignited engines (usually with direct injection) that are operating under lean and ultra-lean conditions. Lean-burn engines exhibit high levels of nitrogen oxide emissions (NOx), that are difficult to treat in oxygen-rich exhaust environments characteristic of lean-burn combustion. Exhaust aftertreatment technologies are currently being developed that treat NOx under these conditions.
[0003] One of these technologies includes a catalyst that facilitates the reactions of ammonia (NH 3 ) with the exhaust nitrogen oxides (NOx) to produce nitrogen (N 2 ) and water (H 2 O). This technology is referred to as Selective Catalytic Reduction (SCR). Ammonia is difficult to handle in its pure form in the automotive environment, therefore it is customary with these systems to use a liquid aqueous urea solution, typically at a 32% concentration of urea (CO(NH 2 ) 2 ). The solution is referred to as AUS-32, and is also known under its commercial name of AdBlue. The urea is delivered to the hot exhaust stream and is transformed into ammonia in the exhaust after undergoing thermolysis, or thermal decomposition, into ammonia and isocyanic acid (HNCO). The isocyanic acid then undergoes a hydrolysis with the water present in the exhaust and is transformed into ammonia and carbon dioxide (CO 2 ), the ammonia resulting from the thermolysis and the hydrolysis then undergoes a catalyzed reaction with the nitrogen oxides as described previously.
[0004] The delivery of the AUS-32 solution to the exhaust involves precise metering of the fluid and proper preparation of the fluid to facilitate the later mixing of the ammonia in the exhaust stream. Previous designs have included these exhaust-mounted concepts, which were improvements over even earlier remote-mount solutions.
[0005] Current systems are in limited volume production for the heavy-duty diesel engine sector. Some SCR systems include production of an injector for passenger car applications. Others include metering control carried out by an injector mounted in a control block. The metered fluid is transported via a tube to the exhaust. After the metering valve, the fluid is also exposed to compressed air to aid with atomization which ensures subsequent good mixing with the exhaust gas. The pressurized mixture is then injected into the exhaust.
[0006] Some systems do not use compressed air because compressed air is not expected to be available on many future applications of the SCR technology, so it is important to have delivery of the AUS-32 without air-assistance.
[0007] Some injection units that do not use compressed air are intended for mounting proximate to the exhaust line, but are passively cooled and thermally decoupled from the hot exhaust line. These designs include a thermally isolating gasket arrangement that prevents heat conduction through the mounting boss to the injector tip, where the urea solution is metered. The preferential conduction path leads toward the outer air-exposed shields, which often are exposed to fairly well-ventilated environments to assist in cooling. The injector tip itself also benefits from cooling provided by the working fluid, such as AUS-32.
[0008] However, in certain applications, the injector mounting location could be in a zone where ventilation is minimal, e.g. behind the engine. In this case, active cooling of the injector may be required to prevent excessive heating of the injector tip, and hence of the AUS-32 working fluid.
SUMMARY OF THE INVENTION
[0009] The present invention is a reductant delivery unit having active cooling. The reductant delivery unit has an upper shield, a lower shield connected to the upper shield, and an inner sleeve. An outer surface of the inner sleeve is connected to an inner surface of the upper shield, and an inner surface of the lower shield. The reductant delivery unit also includes an injector having a solenoid portion and a valve portion, and the valve portion has a lower valve body. A casing partially surrounds the lower valve body, and is part of the solenoid portion. An o-ring is in contact with the inner sleeve, and the o-ring surrounds the casing, providing a sealing function between the casing and the inner sleeve. The lower valve body is connected to a portion of the lower shield at a connection point. A liquid cooling cavity is formed by the connection between the inner sleeve and the lower shield, the lower valve body and the lower shield, the o-ring and the inner sleeve, and the o-ring and the casing.
[0010] An inlet hydraulic connector is connected to the lower shield, and an outlet hydraulic connector connected to the lower shield. Coolant flows from the inlet hydraulic connector into the liquid cooling cavity to provide a cooling function to the injector, and the coolant exits the liquid cooling cavity through the outlet hydraulic connector.
[0011] It is an object of the invention to provide delivery of AUS-32 to the engine exhaust for use in SCR exhaust aftertreatment systems on vehicles via an actively cooled reductant delivery unit (RDU).
[0012] It is another object of this invention to provide active cooling for an RDU from a separate liquid circuit. Although the source of the cooling liquid may be varied, it is within the scope of the invention that engine coolant from an existing engine coolant circuit is used with the RDU of the present invention.
[0013] It is another object of the invention to provide a solution to cooling the exhaust-mount injection units due to extreme high temperature mounting locations.
[0014] 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
[0015] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0016] FIG. 1 is a side view of a reductant delivery unit having active cooling, according to embodiments of the present invention;
[0017] FIG. 2 is a sectional side view of a reductant delivery unit having active cooling, according to embodiments of the present invention;
[0018] FIG. 3 is a side view of a reductant delivery unit having active cooling, according to a first alternate embodiment of the present invention;
[0019] FIG. 4 is a sectional side view of a reductant delivery unit having active cooling, according to a first alternate embodiment of the present invention;
[0020] FIG. 5A is a first perspective view of a reductant delivery unit having active cooling, according to a second alternate embodiment of the present invention;
[0021] FIG. 5B is a top view of a reductant delivery unit having active cooling, according to a second alternate embodiment of the present invention;
[0022] FIG. 5C is a second perspective view of a reductant delivery unit having active cooling, according to a second alternate embodiment of the present invention;
[0023] FIG. 6A is a first perspective view of a reductant delivery unit having active cooling, according to a third alternate embodiment of the present invention;
[0024] FIG. 6B is a top view of a reductant delivery unit having active cooling, according to a third alternate embodiment of the present invention; and
[0025] FIG. 6C is a second perspective view of a reductant delivery unit having active cooling, according to a third alternate embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] 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.
[0027] Referring to the FIGS. 1-2 , an embodiment of a reductant delivery unit for an automotive selective catalytic reduction (SCR) system with active cooling is shown generally at 10 . The reductant delivery unit 10 includes an outer shell or casing, shown generally at 12 , and the shell 12 includes a retaining cap 14 , which is connected to an upper shield 16 , and a lower shield 18 , which is connected to the upper shield 16 . The retaining cap 14 and the shields 16 , 18 when connected together form a cavity, shown generally at 20 , in which various components are disposed.
[0028] The cap 14 at least partially surrounds a hydraulic connector 22 . The hydraulic connector 22 has an inlet pipe 24 , and an inlet cup 26 , which in this embodiment are integrally formed together, but it is within the scope of the invention that the inlet pipe 24 and inlet cup 26 may be formed separately. The inlet pipe 24 includes an aperture 28 which extends through the pipe 24 and is in fluid communication with an inner cavity 30 formed by the inlet cup 26 , best seen in FIG. 2 . The inner cavity 30 is in fluid communication with an injector, shown generally at 32 , which is disposed within the cavity 20 .
[0029] The retaining cap 14 maintains the inlet cup 26 in place via a weld through the upper shield 16 . The upper shield 16 is constructed so as to minimize heat transfer from the hot ambient environment to the inner volumes of the unit 10 and the AUS-32 fluid passages, particularly during heating transients (e.g. engine drop to idle after a mountain climb pulling a trailer). In so doing, the heat capacity of the upper shield 16 protects against short-term heating of the inner components of the injector 32 . The upper shield 16 is joined to the lower shield 18 , also via a laser weld, but also possibly by brazing.
[0030] The injector 32 includes an upper valve body 34 , which is hollow and in fluid communication with the inner cavity 30 . Part of the upper valve body 34 is surrounded by a first seal, which in this embodiment is an upper o-ring 36 which is in contact with the inner wall 38 of the inner cavity 30 , to provide a seal connection between the upper valve body 34 and the inlet cup 26 , ensuring all fluid that flows through the inlet cup 26 passes into the upper valve body 34 .
[0031] The upper valve body 34 is partially surrounded by a housing 40 having a connector 42 . The connector 42 is in electrical communication with a coil 44 , and the coil 44 is part of a solenoid portion, shown generally at 46 . The solenoid portion 46 is part of the injector 32 , and controls the movement of a valve portion, shown generally at 48 , which is also part of the injector 32 . In addition to the coil 44 , the solenoid portion 46 also includes a pole piece 50 surrounded by the coil 44 , and a moveable armature 52 . The pole piece 50 and the armature 52 are substantially hollow such that a return spring 54 is disposed in a cavity, shown generally at 56 , formed by the pole piece 50 and armature 52 . The return spring 54 biases the armature 52 downward when looking at FIG. 2 , and therefore biases the valve portion 48 toward a closed position. The return spring 54 is located between the armature 52 and a stopper 58 .
[0032] The valve portion 48 includes a tube 60 connected to the armature 54 at a first end, shown generally at 62 , and a ball 64 connected to a second end, shown generally at 66 . The ball 64 is part of a valve, and the valve also includes a valve seat 68 . The valve seat 68 is mounted in the lower end of a lower valve body 70 , and the lower valve body 70 is connected to the pole piece 50 , such that the lower valve body 70 is partially surrounded by the coil 44 . Movement of the ball 64 is controlled by a guide 74 . The guide 74 includes a guide aperture 106 through which the ball 64 moves, and also includes side apertures 76 which the fluid flows through. The valve seat 68 includes a conical-shaped portion 78 , upon which the ball 64 rests when the valve is in the closed position. The valve seat 68 also includes a central aperture 80 , through which the fluid passes as the fluid exits the injector 32 .
[0033] During the operation of the injector 32 , the valve, and more specifically the tube 60 and the ball 64 , are biased by the return spring 54 to contact the valve seat 68 , and therefore keep the valve in a closed position. When the coil 44 is energized, the armature 52 is drawn toward the pole piece 50 . The energizing of the coil 44 generates enough force that the armature 52 overcomes the force of the return spring 54 , and moves towards the pole piece 50 . Because the tube 60 is connected to the armature 52 , and the ball 64 is connected to the tube 60 , the movement of the armature 52 towards the pole piece 50 moves the ball 64 away from the valve seat 68 , opening the valve. When the valve is in an open position, the fluid flows from the aperture 28 through the inner cavity 30 , the upper valve body 34 , pole piece 50 , armature 52 , the tube 60 and out a plurality of exit apertures 72 formed as part of the tube 60 . After the fluid flows out of the exit apertures 72 , the fluid passes through the side apertures 76 , and out the central aperture 80 .
[0034] When the coil 44 is no longer energized, the return spring 54 forces the armature 52 away from the pole piece 50 , and moves the armature 52 , the tube 60 and the ball 64 such that the ball 64 is placed against the conical-shaped portion 78 of the valve seat 68 , placing the valve in the closed position.
[0035] The solenoid portion 46 also includes a casing 82 which at least partially surrounds the coil 44 and the lower valve body 70 . Surrounding part of the casing 82 is a second seal, which in this embodiment is a lower o-ring 84 , and the lower o-ring 84 is surrounded by an inner sleeve 86 . The inner sleeve 86 is disposed within the cavity 20 , and part of the outer surface 88 of the inner sleeve 86 is connected (through the use of a weld) to both the inner surface 90 of the upper shield 16 , and the inner surface 108 of the lower shield 18 . The lower end, shown generally at 92 , of the lower shield 18 is shaped such that the lower end 92 contacts the lower valve body 70 , and is welded to the lower valve body 70 at a connection point 94 . The connection between the inner sleeve 86 and the lower shield 18 and the connection between the lower shield 18 and the lower valve body 70 forms a liquid cooling cavity, shown generally at 96 .
[0036] The liquid cooling cavity 96 is also bounded by joining the injector 32 to the lower shield 18 via laser weld, and then by cooperation of the lower o-ring 84 with the inner sleeve 86 .
[0037] The lower shield 18 has various contours and shapes, which not only forms the lower end 92 used for connection with the lower valve body 70 , but also forms the shape of the liquid cooling cavity 96 . There are also two apertures formed as part of the lower shield 18 , into which two hydraulic connectors are fixedly mounted. More specifically, there is an inlet hydraulic connector 98 mounted in a coolant inlet aperture (not shown), and an outlet hydraulic connector 100 mounted in a coolant outlet aperture 102 . The coolant outlet aperture 102 and the coolant inlet aperture are substantially similar, therefore only one is shown.
[0038] The lower shield 18 is joined hermetically to the inner sleeve 86 via laser weld or brazing. The outer surface 88 of the inner sleeve 86 and the inner surface 108 of the lower shield 18 comprise the principal boundary surfaces of the liquid cooling cavity 96 . Liquid is brought to and evacuated from the cavity 96 via the inlet aperture and outlet aperture 102 in the lower shield 18 equipped with hydraulic connectors 98 , 100 , also joined to the lower shield 18 , preferably by brazing.
[0039] The inner sleeve 86 is designed so as to minimize the space between the inside of the inner sleeve 86 and the various injector overmold surfaces. It is also understood that this volume could also be filled with a conductive compound to improve heat transfer to the liquid coolant in the cavity 96 .
[0040] Mounted to the outer surface of the lower shield 18 is a v-clamp flange 104 which is used for mounting the reductant delivery unit 10 somewhere along the exhaust system. In one embodiment, the reductant delivery unit 10 may be mounted to an exhaust pipe, but it is within the scope of the invention that the reductant delivery unit 10 may be mounted to an exhaust manifold, or other exhaust system component. During the operation of the unit 10 , engine coolant is pumped to the inlet hydraulic connector 98 and flows through the inlet hydraulic connector 98 into the liquid cooling cavity 96 . The coolant then circulates through the liquid cooling cavity 96 and exits the liquid cooling cavity 96 through the outlet hydraulic connector 100 . The coolant is prevented from contacting the solenoid portion 46 of the injector 32 because of the o-ring 84 . This circulation of coolant into and out of the liquid cooling cavity 96 cools the reductant delivery unit 10 , and provides the reductant delivery unit 10 with a more consistent operating temperature.
[0041] The interface with the exhaust line is shown here as one suited for the v-clamp flange 104 . Other mounting configurations are also possible, including flanges with bolts. The v-clamp flange 104 (or other flange configurations) is joined to the lower shield 18 , also preferably by brazing. It is understood that a number of the braze operations could be accomplished simultaneously with one operation. The flanges 104 would then provide suitable surfaces and geometries for implementation of a sealing gasket to prevent exhaust gas leakage through the flange/boss interface.
[0042] An additional advantage of providing the reductant delivery unit 10 with liquid cooling is the unit 10 then has the ability to maintain a constant fluid temperature of the urea, as defined by the liquid cooling circuit. In this way, temperature corrections to adjust for density and viscosity changes in the working fluid can be greatly simplified, or even eliminated, as can be any temperature feedback systems that would be normally required (e.g. coil current measurements).
[0043] When in use, urea solution is fed through the inlet pipe 24 , such that the urea solution passes through the inner cavity 30 and into the upper valve body 34 of the injector 32 . In this embodiment, the inlet pipe 24 is depicted as being substantially perpendicular to the injector 32 , which presents certain packaging advantages for some installations. However, the radial orientation of the inlet pipe 24 may be varied, as well as the axial orientation. In this embodiment, the inlet pipe 24 and the inlet cup 26 are integrated as one piece; however, a two piece construction (inlet pipe 24 and inlet cup 26 ) is also possible which may be advantageous from a construction standpoint.
[0044] An alternate embodiment of the invention is shown in FIGS. 3-4 , with like numbers referring to like elements. However, in this embodiment, the hydraulic connectors 98 , 100 are located at different positions relative to the v-clamp flange 104 and the hydraulic connector 22 . More specifically, the inlet hydraulic connector 98 is located closer to the v-clamp flange 104 and the lower valve body 70 compared to the outlet hydraulic connector 100 . This causes the coolant flowing into the liquid cooling cavity 96 to circulate differently compared to the embodiment described in FIGS. 1-2 , and therefore provides a different manner of cooling. Furthermore, in the embodiment shown in FIGS. 3-4 , the inlet pipe 24 and inlet cup 26 are formed as separate components, and then are assembled to form the hydraulic connector 22 . This embodiment is also not limited to what is shown in FIGS. 3-4 , the inlet pipe 24 and inlet cup 24 may be integrally formed together, as shown in FIGS. 1-2 . Additionally, the inlet pipe 24 may be oriented to be substantially parallel with the injector 32 , instead of being oriented perpendicularly, as shown in FIGS. 3-4 .
[0045] Other embodiments of the invention are shown in FIGS. 5A-6C . One embodiment of the invention is shown in FIGS. 5A-5C , with like numbers referring to like elements. In FIGS. 5A-5C , the inlet pipe 24 is not only oriented parallel to the injector 32 , the inlet pipe 24 is also substantially aligned with the injector 32 .
[0046] Referring now to the embodiment shown in FIGS. 6A-6C , the unit 10 shown in these Figures is similar to the previous embodiments, with like numbers referring to like elements. However, the unit 10 shown in FIGS. 6A-6C is a high-volume unit 10 , and is larger in size compared to the previously described embodiments. The unit 10 shown in FIGS. 6A-6C allows for a greater amount of urea solution to pass through the injector 32 , and a greater amount of coolant to pass through the unit 10 .
[0047] The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
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A reductant delivery unit (RDU) delivers supplied reductant (aqueous urea solution) to the engine exhaust system. The delivered reductant is transformed into ammonia which then reacts with the exhaust oxides of nitrogen in a catalytic environment to produce nitrogen and H20. The reductant must be metered to coincide with the amount of NOx present in the exhaust, and also present sufficient spray quality of the delivered fluid to promote good mixing of the ammonia with the exhaust gas. The RDU is a liquid-cooled, making the RDU suitable for very high temperature environment applications.
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CROSS REFERENCE TO RELATED APPLICATION
This present application claims benefit of priority from U.S. Provisional Patent Application Ser. No. 61/103,613, filed Oct. 8, 2008. The disclosure of the aforementioned patent application is incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and system for replacing portions of building surfaces. Particularly, the present invention is directed to a method and system for replacing broken shingles and shakes.
2. Description of Related Art
Wood shingles and shakes are usually milled from quarter sawn wood. Cedar or redwood are commonly used. The wood is usually quarter-sawn to minimize cupping of the wood. Cupping is the tendency of wood to deform with absorption of moisture. Shingles or shakes are generally not sealed on the back side, and are frequently unfinished or finished with a low bodied coating to minimize cupping. This cupping, even when kept to a minimum, tends to cause movement about the nails securing the shake or shingle to the building structure. Over time, this movement occasionally causes cracking through the length of the shake or shingle, causing the un-attached fractured shingle or shake parts to eventually fall out of their space in the wall or roof area. Replacement of the shake or shingle with a new, unbroken one is typically laborious and runs the risk of breaking adjacent shakes or shingles as, after years of exposure, all of the shakes or shingles are more apt to crack and break.
As will be appreciated, there remains in the art a need for simpler approaches to repair building surfaces, such as shingled surfaces. The present invention provides a solution for these problems.
SUMMARY OF THE DISCLOSURE
The purpose and advantages of the present invention will be set forth in and become apparent from the description that follows. Additional advantages of the invention will be realized and attained by the methods and systems particularly pointed out in the written description and claims hereof, as well as from the appended drawings.
In accordance with a first embodiment, a clip is provided for repairing building surfaces. the clip includes a first generally planar elongate portion having an inner face and an outer face, and a second generally planar elongate portion having an inner face and an outer face. The first elongate portion and second elongate portion are joined to define a generally U-shaped member having a generally elongate gap defined by the inner faces of the first and second elongate portions, the gap being adapted and configured to receive a building member therein.
In accordance with a further aspect, the clip can further include a building member (e.g., shingle, shake, piece of clapboard siding, or roofing slate) disposed between the first and second elongate portions. The clip can be made from a material including a corrosion-resistant metal and/or a plastic material. Preferably, the clip includes at least one protrusion disposed on at least one of the elongate portions. The at least one protrusion can extend inwardly from at least one of the elongate portions, the at least one protrusion being suitable for gripping a building member inserted into the gap. If desired, the at least one protrusion can extend outwardly from at least one of the elongate portions, the at least one protrusion being suitable for gripping the surface of an adjacent building member in a building structure. If desired, protrusions can extend both inwardly and outwardly, as desired. In one embodiment, the clip defines at least one hole therein that is adapted and configured to receive a fastening member to secure the clip to a structure. In one embodiment, the first and second elongate portions are of different lengths. If desired, the clip can further include an outwardly facing lip portion formed along an end of one of the elongate portions, the lip portion being adapted and configured to act as a stop against the bottom of an adjacent building member in a building structure when the clip is installed. The lip portion can be adapted and configured to match an adjacent building member in a structure. In accordance with one embodiment, the building member can be shorter than a building member of standard length. In the case, for example, of clapboard siding, this would correspond to a width that corresponds to a vertical height when installed. With respect to standard length, it will be appreciated that this is to be considered with reference to surrounding building members, even if they are of a custom length (or width in the case of siding members).
In accordance with another embodiment, a method is provided including providing a clip as recited herein, disposing a building member in the gap of the clip, and inserting the building member and clip into a recess defined by removal of a building member in a building structure to effectuate a repair to a surface of a building.
If desired, the building member can be disposed in the gap prior to inserting the building member and clip into the recess. Alternatively, the building member can be disposed in the gap after to inserting the building member and clip into the recess. The method can further include attaching the clip to the building structure by attaching a fastener to the clip. The fastener can be attached to the clip prior to inserting the building member into the gap.
In accordance with still another embodiment, a building structure is provided. The structure includes a surface comprising a plurality of building members, and the clip of claim 1 with a building member inserted therein, wherein the clip and inserted building member are disposed in a recess defined by removal of a building member in a the surface. In accordance with further aspects, the surface can be a roof surface of the building structure, or a wall surface of the building structure.
For a full understanding of embodiments of the present invention, reference should now be made to the following detailed description of the preferred embodiments of the invention as illustrated in the accompanying drawings. It is to be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the invention described and claimed herein.
The accompanying drawings, which are incorporated in and constitute part of this specification, are included to illustrate and provide a further understanding of the method and system of the invention. Together with the description, the drawings serve to explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a device made in accordance with the present invention.
FIG. 2 is a cross sectional view of a building depicting the device of FIG. 1 in use for purposes of replacing a shingle.
FIG. 3 is a partial view of an exemplary slate having an interrupted surface.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. The method and corresponding steps of the invention will be described in conjunction with the detailed description of the system.
The devices and methods presented herein may be used for repairing surfaces of structures. The present invention is particularly suited for facilitating the repair of shakes and shingles, as well as any other surface that is applied in layers, such as clapboard siding, slate and roofing tiles, among others.
For purposes of illustration, and not limitation, as embodied herein and as depicted in FIG. 1 , a device 100 is provided. As depicted in FIG. 1 , the device 100 comprises a generally “U” shaped clip-type device that is preferably made from a corrosion-resistant metal or plastic material. The device includes a clip body 101 having a first bottom, or back portion 102 with a plurality of protrusions 103 , such as pointed teeth, and a plurality of pre-formed fastener holes, 112 . Holes 112 can be used to facilitate attachment of the device 100 to the building structure, as described in further detail below. Device 100 further includes a second top, or front portion 104 that is joined to portion 102 at a junction 109 . As depicted, portion 104 may also be provided with a plurality of protrusions 103 facing inwardly into a gap “G” defined between members 102 and 104 , and/or outwardly, as desired. As is further depicted, the length of portion 102 is preferably longer than portion 104 to facilitate operation of the device.
For purposes of further illustration, FIG. 2 depicts a sectional view through a wood roof showing positioning of a device made in accordance with the invention. When replacing a broken component such as a shingle or a shake, the broken pieces of shingle or shake are first removed if they are still present. Next, one or more devices 100 are inserted into the gap created by the absence of the old shake or shingle. The portion 109 of device 100 is inserted first into the cavity, until front portion 104 of device 100 is essentially covered by the upper shake. If desired, a lip 108 can be formed into device 100 to butt up against the upper shake to prevent the device 100 from moving too deeply between the remaining shingles or shakes. Inclusion of the lip 108 is optional, however. Fasteners such as nails can then be disposed through holes 112 , thereby securing the device 100 into place. The fasteners are directed through the shingle or shake course, and sheathing, or lathing, 107 , and into the rafter space or rafter, 106 . Annular ring nails or screws are preferably used to accomplish the fastening operation. Alternatively, protrusions or barbs 103 can be provided on the device 100 (on portions 102 and 104 , for example) that face outwardly and bite into surrounding shingles.
As depicted in FIG. 2 , the bent portion 109 of the device 100 preferably does not extend as far as the original shake or shingle, 105 , shown as a dashed line. Thus, the original nails 115 from the broken shake may be left in place without having to drive them down to permit insertion of the clip, although it is possible that other nails may be encountered that need to be driven down or bent over during the clip's insertion. Reference numeral 104 indicates the clearance between the top and bottom parts of the device 100 . The replacement shingle or shake is then cut down to an appropriate length shorter than the length of the surrounding shingles, and thickness to allow insertion of the replacement shake into the clip device 100 wherein the thickness of the upper 104 and lower 102 parts of device 100 as well as room for the compressed teeth 103 are accommodated without applying stress to the upper shake or shingle courses. If desired, the shingles or shakes (or clapboard siding or roofing slates, described below) can be pre-mounted into the clip and sold as a unit such as with an adhesive or the like. As will be appreciated, the teeth 103 can be positioned substantially perpendicularly to the surfaces 102 and 104 , or preferably angled slightly with respect to the perpendicular in order to better dig into the replacement shake. As will be further appreciated, retainers 103 may have sharp edges or simply may include a resilient deflectable member that is adapted and configured to grip a shake, shingle, slate or other object inserted into device 100 .
As described above, the lower portion 102 of device 100 is preferably longer than the upper portion 104 to permit portion 102 to extend past the outer edge of the upper portion 104 to allow attachment through holes 112 . It is possible for only a single fastener to be used to secure the device 100 to the structure. The additional depicted holes may be provided to facilitate alignment of device 100 with respect to other existing shingles or shakes. As will be further appreciated, one or both of the inner surfaces of portions 102 , 104 of device 100 may include teeth or other retaining means to hold a new shake or shingle in place. As alluded to above, the optional lip portion 108 may be provided to facilitate tapping of the device 100 into position to serve as a guide to the installer, to tap it in until it just touches the edge of the upper existing shingle or shake. Lip portion 108 can also be used to provide additional support for the upper-course of existing shingles as well. The exposed face of the lip 108 may be provided with a matte finish to make it less conspicuous after installation. The lip 108 may be provided in alternate embodiments, as a partial or interrupted lip, having one or more short sections of tabs extending from the upper portion 104 , for example. In this manner, the function of the optional lip 108 is retained, without noticeable compromising of the aesthetic of a building. By way of further example, one or more drain holes 110 may be provided proximate lip to help prevent the excessive absorption of water into the end grain of the upper course shingle or shake, particularly in a roof application. However, it will be appreciated that device may also be used in wall applications and not only in roof applications. In either case, drain holes can alternatively be provided in the lip 108 , if present.
For the purpose of minimally affecting the aesthetic impact of the device 100 , the device 100 can be provided in any desired color, including but not limited to tan, silver, white, gray, black, or brown. The color of the device 100 can be selected to mimic the current or future (weathered) color of the materials with which it is used. For example, a light gray color can be used if used with new or old weathered cedar shingles, for example. It is conceived that a metal material such as, but not limited to, aluminum or steel would be advantageous. However, as set forth above, the device can be formed from a polymeric material, among others, such as composite materials.
Moreover, the device 100 can be offered in a variety of widths and depths for use in a variety of width and depths of spaces, due to the typical irregularities in size of wood shingles, shakes or slates. If desired, the device 100 can mainly be offered in relatively narrower widths, which can also effectively be used on wider shingles, shakes or slates. Alternatively still, the device 100 can be embodied such that it can be easily broken into narrower parts, such as by snapping, scoring or cutting, for example.
As can be appreciated by those of skill in the art, the entire repair of a broken shake using devices and methods in accordance with the invention can take far less time than prior art approaches and is far less likely to disturb adjacent shingles or shakes. It is believed that the retainers 103 will reduce the stress on the replaced shake, ensuring a long-lasting repair.
In accordance with a further example, similar devices may be used to replace sections of clapboard siding as well as slate roofs. In the context of clapboard siding, a plurality of such devices can be driven into a gap created by a removed section of siding. A new piece of siding can then be driven into the gap.
In the context of slate roof repair, a similar device may be employed to secure new slates. Special repair slates can be provided having an interrupted surface, such as lateral grooves 300 across the portion of the slate depicted in FIG. 3 , in order to facilitate the pointed fingers' positive grabbing and locking-into the slate's interrupted surface. The replacement slate can be made from stone, or from man made materials that simulate the appearance of slate, as desired. In accordance with a further aspect, holes can be drilled through the existing slate if it is not feasible to align a nail hole in the clip with an open joint in the lower slate course. By way of further example, it is also possible to provide a resilient protrusion (similar to protrusions 103 ) that protrude outwardly from the back surface of portion 102 proximate the junction 109 to catch the top of the rear slate to keep the device 100 and replacement slate from slipping downward.
In accordance with another aspect of the invention, device 100 may employ a variety of additional or alternative means for retaining a replacement shingle, shake, slate or tile therein. In accordance with one embodiment, rather than using protrusions to grip a replacement shake, shingle, tile or slate, adhesive such as construction adhesive may be used to secure the new structural element within device 100 . By way of further example, the interior face of the device 100 may be provided with a gripping surface (e.g., silicone surface) that tends to grip the replacement structural element when the structural element is forced between portions 102 and 104 of device 100 .
In any embodiment, for use with wood, stone, or man-made materials such as roofing tiles, the device 100 can include protrusions both on one or more of the inner surfaces as illustrated, and on one or more of the outer surfaces (top and/or bottom) for engaging the adjacent roofing materials or other adjacent elements. In such embodiments, the outer protrusions can be oriented as with the inner protrusions 103 to inhibit pullout of the device 100 and a roofing component (shake, shingle, slate, tile, etc.).
The dimensions of the protrusions 103 can be selected as desired, and may be embodied as relatively small barbs, for example in the range of 1.0 mm to 5.0 mm. Alternatively, the protrusions can be in the range of about 5.0 mm to 10.0 mm or about 10.0 mm to about 50.0 mm. Depending on the precise embodiment, intended use and materials, the dimensions can be selected accordingly. Moreover, the protrusions 103 can be substantially triangularly shaped, as shown, or can be embodied in another shape, such as one having a substantially straight end.
The methods and systems of the present invention, as described above and shown in the drawings, provide for an improved method and system for building surface repair. It will be apparent to those skilled in the art that various modifications and variations can be made in the device and method of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention include modifications and variations that are within the scope of the subject disclosure and equivalents.
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The disclosure relates to a clip and associated method and building structure. The clip is provided for repairing building surfaces. The clip includes a first generally planar elongate portion having an inner face and an outer face, and a second generally planar elongate portion having an inner face and an outer face. The first elongate portion and second elongate portion are joined to define a generally U-shaped member having a generally elongate gap defined by the inner faces of the first and second elongate portions, the gap being adapted and configured to receive a building member therein.
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FIELD OF THE DISCLOSURE
This disclosure relates in general to voltage converters, and more particularly, to a feedback control method of a voltage converter and relative control loop of a converter.
BACKGROUND
Central processing units (CPUs) for personal computers, workstations, servers, graphic processor units (GPU) and memory controllers may use very complex controlled supply voltage generators. The supply voltage generators may be very precise both during an idle condition as well as during load transients. In general, supply voltage generators are input with a voltage of 5V or 12V and generate output voltages ranging from 0.5V to 2V. Mono-phase or multi-phase buck voltage converters, for example, of the type illustrated in FIG. 1 , are generally preferred for these applications.
In order to effectively respond to very fast and large load transients (for CPU, up to 100 A in 50 ns) these converters need nonlinear controls that are enabled in presence of load transients and turn on simultaneously all the available phases for sustaining the output voltage.
Specifications for conditions of load transients may be restrictive during load increases as well as during load decreases and it may be advisable not to surpass the design maximum voltage. Independently from the fact that a mono-phase or a multi-phase converter is considered, the feedback network used for controlling the converter modifies the response to load changes. Depending on the fact that either linear or nonlinear techniques are used, as discussed in the U.S. Patent Application Publication No. 2007/0229048 to Zambetti et al., also assigned to the present application's assignee, the disclosure of which is incorporated by reference in its entirety, a converter may respond to a load transient by turning on all the phases (in case of a multi-phase) or only some of them. In any case, the response of the converter may be strongly dependent on the characteristics of the application's feedback network, and of the output filter (windings and capacitances), from the input voltage and from the type of modulation ramp (trailing edge, leading edge, dual edge and eventual nonlinear modulation systems) being used.
Specifications relating to windings, to the switching frequency, to the output capacitance and to the input voltage may be fixed when designing the integrated device. Nevertheless, in order to satisfy all specifications at critical load transients, it is often helpful to increase the output capacitance with a consequent added cost.
Referring to FIG. 1 , in order to respond effectively to a load variation, it is helpful to increase the control voltage (COMP) as fast as possible, thus with a large band, in order to always cross the modulation ramp (PWM_RAMP). Therefore, the gain during load transients may be sufficiently large. The effect of a large gain on the control voltage COMP may be useful at relatively low load transient frequency for making effective the response (as shown in FIG. 2 with a dashed line), though this may degrade the response of the system at medium/high load frequencies causing an overshoot on the output voltage and making it exit out of specifications imposed to the load, as illustrated in FIG. 3 . The figure shows a qualitative example of the output voltage (V OUT ), of the current through the winding (I L ), of the modulation ramp (PWM_RAMP) and of the control voltage (COMP) at medium/large load frequency (I LOAD ) when the gain on the control voltage COMP varies, in a mono-phase system.
At medium/high frequencies, because of the significant time constant of the output filter, the current through the inductor is stable around the mean value of the two current levels (I REL and I APP ) used by the load. In absence of fluctuations between the load frequency and the switching frequency, that could be prevented for example, by suitably nonlinear systems, the output voltage may be driven with a constant duty-cycle.
As it may be inferred from the example shown, in order to keep the correct duty-cycle, the control system shifts its response toward the functioning zone of load reduction (i.e. transition from a high load current to a low load current) when the voltage gain of the block COMP increases, thus generating a delay in the closed loop response equal to T D . By shifting the response, the excess charge in the inductor (ΔQ C — REL ) is supplied to the output capacitance, thus producing an overshoot of the voltage (ΔV OVER ), i.e. an overshoot increases during the load reduction events that could systematically lead to the maximum output voltage being out of the specifications with consequences on the reliability of the device powered by the converter.
This charge may be estimated with the following formula:
Δ Q C_REL = V OUT 2 L T D · T LOAD
and may generate an overshoot equal to:
Δ V OUT_REL = V OUT 2 L · C OUT T D · T LOAD
From the examples of FIGS. 2 and 3 , it is evident that a high gain compensation network in presence of transients may be good at low load frequency but could lead the system out of its specifications, as far as overshoot of the output voltage at medium/high load frequency is concerned.
A known technique for reducing the overshoot of the output voltage during load reductions is known as “Body Brake” or “Diode Emulation.” This technique is based on turning on the free-wheeling diode of the low side MOS (and in case of a multi-phase system of all the low-side MOS) for quickly demagnetizing the output inductors by discharging them with a voltage equal to V OUT +V DIODE wherein V DIODE is the voltage of the free-wheeling diode of the low side MOS when turned on as shown in FIGS. 4 and 5 . In order to turn on the free-wheeling diode during a load decrease, it is helpful to monitor the output (U.S. Patent Application Publication No. 2007/0229049 to Zafarana et al., also assigned to the present application's assignee) or, indirectly, the signal COMP for revealing when a load decrement is occurring and placing in a high impedance state both the low side as well as the high side MOS.
Advantages and drawbacks of this technique are well illustrated in the reference authored by Don Caron and titled “Using Diode Emulation To Reduce Output Voltage Overshoot During a Transient Load Release,” and herein incorporated by reference in its entirety. More particularly, this document may illustrate the helpfulness of the use of the Diode Emulation technique at medium/high load frequencies. Indeed, because of the overshoot due to the load reduction at medium/high frequencies (around 350 kHz in the example of FIG. 6 ), the increment of power consumption by the free-wheeling diode and thus by the low side MOS is particularly large, about 20% larger, and could even compromise thermal design of the application. In low cost designs where thermal design of the application is already done at extreme conditions, such an increment of dissipated power may be problematic.
SUMMARY OF THE DISCLOSURE
An object of the present disclosure may be to look for approaches that reduce overshoots due to load reductions at medium/high frequencies without affecting thermal dissipation of the application and without using the free-wheeling diode of the low side MOS.
An aspect is directed to a feedback control method of a voltage converter and a relative control loop for enhancing the response to a load transient, which may minimize overshoots of the output voltage at medium/high load frequencies when the control voltage (COMP) is below the modulation ramp during load application, independently from the compensation network and modulation ramp being used. According to the method, the gain of the control voltage (COMP) is not altered, rather its offset value may be reduced depending on whether the output voltage exceeds a pre-established design threshold. With this technique, the energy characteristics of the PWM converter may remain unchanged, but the beginning of the interval in which the converter may be energized is anticipated for contrasting overshoots of the output voltages. The method may be implemented in a structured control loop.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a regulation loop of a PWM voltage converter, according to the prior art.
FIG. 2 is a graph showing the overshoot of the output voltage V OUT of the converter of FIG. 1 after a sharp reduction of the current used by a supplied load at low switching frequency.
FIG. 3 is a graph showing the overshoot of the output voltage V OUT of the converter of FIG. 1 after a sharp reduction of the current used by a supplied load at high switching frequency.
FIG. 4 illustrates the Diode Emulation technique for limiting overshoots of the output voltage of a PWM voltage converter, according to the prior art.
FIG. 5 is a time graph of the waveforms of the main signal of the converter of FIG. 4 .
FIG. 6 is a graph illustrating the increase of power absorption at high switching frequency, according to the prior art.
FIG. 7 is a time diagram that compares the effect of the increase of the gain of the control voltage in the unit time with the same on time T ON of the converter, according to the prior art.
FIG. 8 is a block diagram of a voltage converter that comprises an adder of an offset voltage to the comparison signal, according to the prior art.
FIG. 9 is a time diagram that compares the combined effect of the addition of an offset signal to the comparison signal with the increment of the gain of the control voltage for a same energization time T ON of the converter of FIG. 8 .
FIG. 10 illustrates the combined effect of the correction of the offset voltage of the comparison signal by keeping constant the energization time of the PWM voltage converter of the converter of FIG. 8 .
FIG. 11 depicts a control loop of a PWM voltage converter, according to the present disclosure.
FIG. 12 illustrates an embodiment of the circuit of FIG. 11 .
FIG. 13 is a time diagram of the signals of the circuit of FIG. 12 and of the output voltage V OUT .
FIG. 14 illustrates another embodiment of the circuit of FIG. 11 with maximum threshold that may be set with the current generator I OVER .
FIGS. 15A-15C are time diagrams of the main signals of a regulation loop of a three-phase PWM converter obtained through simulations by implementing the method, according to the present disclosure.
FIGS. 16A-16C are time diagrams of the main signals of a regulation loop of a three-phase PWM converter obtained through simulations having preliminarily disabled the circuit, according to the present disclosure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present disclosure is illustrated in a particular architecture of an exemplary voltage converter type, though, as may be apparent hereinafter, the same considerations hold also for voltage converters having a different architecture.
In order to better understand the problem, it may be useful to analyze in the time domain the response of the control voltage COMP during a load transition. Looking at FIG. 7 , it may be noticed how the response to the load application with higher gain shifts to the right toward the load decrease zone, as already discussed. The two voltages (COMP 1 and COMP 2 ), having different gains, may have initially a different slope and thus may cross at different instants the modulation ramp (PWM_RAMP).
Even if the slopes are different, by introducing an offset on the output voltage of the error amplifier, as shown in FIG. 8 , the control loop, in order to have the same T ON with the same gain, may shift the control voltage toward the load increase zone if the added offset is negative (V CM1 ) or toward the load reduction zone if the added offset is positive (V CM2 ), as shown in FIG. 9 .
As may be noticed in FIG. 9 , having added a positive offset to the control voltage of larger gain (COMP 2 ) and a negative offset to the control voltage of smaller gain (COMP 1 ), the system with the larger voltage may respond before the system with the smaller gain, i.e. the initial condition is reversed.
Indeed, the control voltage of the larger gain anticipates the control voltage of the smaller gain and, as previously described, this leads to a smaller overshoot of the output voltage at medium/high frequency during a load decrement. The introduction of a static offset (identified also as the common mode voltage V CM ) to the control voltage (COMP) significantly changes the transient response of the system. This behavior cannot be modeled in the frequency domain because the introduction of a static offset on the control voltage does not influence the frequency signal.
In order to better understand the effect of the introduced offset it is useful to study the load transient as a large signal and not as a small signal (as usually is done in a frequency analysis). When there is no overshoot on the output voltage, it is preferable to have the control voltage as close as possible to the modulation ramp for responding as fast as possible to a load application. Indeed, if the voltage COMP is smaller than the modulation ramp during application of the load, having a higher common mode voltage (V CM0 ) helps reaching the ramp earlier and thus generating a PWM signal for responding to the transient.
In the presence of overshoots, independently from the gain on the control voltage, it is useful to add the common mode voltage with relatively small value or even of negative value for increasing the latency of the system and anticipating the response toward the load increase zone and not toward the load decrease zone, thus reducing the overshoot as far as keeping it within specifications. FIG. 10 illustrates the functioning principle.
The common mode voltage V CM , also referred to as the offset voltage, that is added to the voltage COMP may be regulated by a control loop, for example, of the type illustrated in FIG. 11 to prevent the output voltage from exceeding a given maximum threshold. The overshoot control circuit is input with the output voltage V OUT , with a threshold (V TH — MAX ) that determines the maximum voltage value to be applied to the load, with a reference pulse signal P REF that may be generated by the system clock and with a ramp reset signal coming from the PWM OSCILLATOR or from the PWM driving signal of the converter.
Regulation of the common mode voltage to be added is done only in presence of overshoots on the output voltage, thus the response speed of the system at low/medium frequency when the voltage COMP is below the modulation ramp when a load is applied is not jeopardized.
FIG. 12 illustrates a block diagram of the control circuit. Every time the voltage V OUT exceeds the threshold V THMAX , a pulse of a duration T OVER closes the switch S 1 and the capacitance C is charged with a current I up . During this phase the voltage V c increases. When an externally generated command pulse P REF having a duration T REF is received, the switch S 2 is closed and the capacitor C is discharged with a current I DOWN . During this phase, the voltage VC decreases. If neither the pulse P REF nor the output signal of the overshoot comparator is received, the capacitor C keeps its charge and thus the voltage V c remains constant.
The voltage V c is multiplied by a gain factor K (for example, by introducing a filter for removing disturbances on the control voltage) generating the voltage V ADJ . This voltage is subtracted from the output voltage of the error amplifier and the common mode voltage V CM0 for reducing the control voltage COMP.
The effect of an increase of the voltage V ADJ on the control voltage COMP and thus on the overshoot of the system has been described hereinbefore. By diminishing the overshoot of the regulated output voltage, the time T OVER during which the output exceeds the threshold V THMAX decreases, with the effect of charging less the capacitor C.
When the system is in a steady-state condition, there is a charge equilibrium between the charge supplied during T OVER and the charge delivered during T REF , thus:
T
OVER
=
I
DOWN
I
UP
T
REF
.
This means that the threshold V THMAX should be overcome for a period of time T REF in order to make the system work in closed loop conditions. If the voltage V OUT does not exceed the threshold V THMAX , at each pulse P REF , the capacitor is discharged with the current I DOWN for a time T REF up to discharge completely and restoring the control voltage COMP with maximum common mode voltage equal to V CM0 . It is thus possible to design the duration of T REF , the threshold V THMAX and the charge and discharge currents I up and I DOWN with values adapted to satisfy load change specifications.
FIG. 13 illustrates a qualitative example of the functioning before and after the overshoot control system is enabled by the enabling signal EN. If the bandwidth of the overshoot control system is much smaller than the bandwidth of the output voltage regulation system, the signal V ADJ may be “seen” by the regulation system as a quasi-static signal, and thus, the interaction between the two control loops and the perturbation on the regulated output may be negligible. In this situation, it is common that the control loops are “almost orthogonal” to each other.
The overshoot threshold may be programmed through a commonly present sense terminal (V SEN ) of the output voltage, as shown in FIG. 14 . By setting the negative terminal of the overshoot comparator at the V REF voltage, that is to the reference value of the output voltage regulation, and by introducing a current generator I OVER between the positive terminal of the comparator and ground, it is possible to program the threshold by introducing a resistor R OVER between the sense terminal of the output voltage and the terminal of the voltage V OUT , as shown in FIG. 14 . The maximum overshoot voltage, that is the threshold voltage V THMAX , is:
VTH MAX =V REF +R OVER ·I OVER
In FIGS. 15A-15C and 16 A- 16 C, two exemplary embodiments of simulation of the functioning of a three-phase converter (in this case the scale is not the same for the two embodiments) respectively with and without the overshoot control system of this disclosure. Notably, in the second embodiment the maximum voltage is smaller than in the first embodiment and is effectively limited to the threshold voltage V THMAX .
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A feedback control method of a pulse width modulator (PWM) voltage converter may include generating a control voltage as a sum of an offset voltage and an error signal representing a difference between a scaled replica of a regulated output voltage of the voltage converter and a reference voltage, comparing the control voltage with a ramp signal, the comparing operation generating PWM driving signals for the voltage converter, comparing the regulated output voltage of the voltage converter with an overshoot threshold, and reducing the control voltage when the overshoot threshold is exceeded.
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CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the benefit of German patent application 102004003032.4, filed Jan. 21, 2004, herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The invention relates to a method for the production of a fancy yarn, particularly such a method in which an effect configuration is predetermined and data is generated therefrom representing the selected effect configuration, and spinning adjustments are generated based on this data.
[0003] A yarn is called a fancy yarn, in which thick locations are present with predetermined larger diameters and with predetermined lengths, the so-called effects. The yarn sections located in between with a smaller diameter, in other words, the effect-free sections, are called webs. The effect data determining a fancy yarn include, in particular, the effect length, the effect diameter, the effect frequency and the respective effect-free thread length or web length.
[0004] Fancy yarns are becoming increasingly important. Areas of use are, for example, denim materials, materials for casual clothing and home textiles.
[0005] Fancy yarns can also be produced on rotor spinning machines. In this case, for example, the fiber feed to the opening roller of the rotor spinning mechanism is changed, in that the rotational speed of the draw-in rollers is varied. For this purpose, mechanical gearings are activated, which drive continuous shafts along the machine. The draw-in rollers are made to rotate by means of these shafts. The large mass of the moved parts of a drive system of this type and the gearing play, however, makes it impossible, or only with difficulty, to achieve a precise and abrupt change of the yarn thickness at the beginning and end of an effect. The speed during the spinning of fancy yarn optionally has to be sharply reduced compared to the speed when spinning effect-free yarn.
[0006] German Patent Publication DE 44 04 503 A1 describes a rotor spinning machine, in which each draw-in roller with its drive shaft is directly connected to an associated stepping motor. Each stepping motor can be activated by an activation unit. Random speed changes of the fiber band intake can be generated with a random generator. A fancy yarn with predetermined effects cannot be produced with this known rotor spinning machine. However, programs for controlling ring or rotor spinning machines, especially their delivery cylinders, have been developed, with which effects can be adjusted in a targeted manner.
[0007] The spinning machine described in German Patent Publication DE 40 41 130 A1, is used for producing fancy yarn using a program control for the effect formation. Specifications such as rotational speed of the drive motors, speeds or specific machine parameters are provided and controlled. For example, for a specific flame or effect type of the fancy yarn to be produced, the rotational speed course of the electric motor is predetermined as a desired value curve. The actual rotational speed is monitored, for example, and recorded in a control device. By maintaining the predetermined rotational speed course, the configuration of the predetermined design of the fancy yarn should be ensured. Deviations from the desired configuration of the fancy yarn, such as may occur despite adhering to specific mentioned specification values, are not recognized in the spinning machine of German Patent Publication DE 40 41 130 A1. This can lead to a reduction in the quality of the fancy yarn or even to the production of reject yarn.
[0008] The configuration of the fancy yarn during rotor spinning does not only depend on the control of the draw-in roller, but is also influenced, for example, by the low pressure in the spinning device or by the yarn rotation. It can therefore easily occur that the diverse influencing variables are inadequately coordinated and the configuration of the fancy yarn produced differs from the predetermined configuration of the fancy yarn to an undesired extent. A change in the spinning adjustments on the basis of a visual qualifying checking of the yarn often leads to costly and very time-consuming coordination processes.
SUMMARY OF THE INVENTION
[0009] The object of the invention is to propose a method which improves the correspondence of the fancy yarn produced with the predetermined configuration of the fancy yarn.
[0010] This object is achieved by an improved method for the production of a fancy yarn, in which an effect configuration is predetermined and data is generated therefrom to represent the selected effect configuration, and in which spinning adjustments are generated based on this data. The present invention is characterized in that once the fancy yarn has been formed in a spinning device, the yarn is guided through a sensor mechanism, and at least one of the parameters, diameter and mass of the fancy yarn is continuously measured by means of the sensor mechanism, the measured values are evaluated, the effect configuration of the yarn produced is determined therefrom and is compared with the predetermined effect configuration, and the spinning adjustments are changed until an adequate correspondence is achieved between the predetermined effect configuration and the effect configuration of the yarn produced.
[0011] Advantageous further configurations of the invention are described hereinafter.
[0012] Owing to the method according to the invention, a monitoring of the configuration of the fancy yarn is carried out, which allows comparison on the basis of quantified properties of the fancy yarn. Comparison can take place until adequate correspondence with the predetermined configuration of the fancy yarn has been achieved. In other words, it is possible, according to the present invention, to check the result of the respective change of parameters, in a plurality of cycles, and to again introduce a change. In this manner, a yarn can be generated, which substantially corresponds to the predetermined configuration of the fancy yarn.
[0013] The correspondence can be checked, in each case, either by statistical recording, in particular recording the effects in tables, in other words, their thickness, length and distribution or else displaying them on a screen. The display on a screen can be carried out, for example, by means of the Oasys® system from Zweigle. A specification in tables in the form of a so-called effect table describes the pattern repeat of the fancy yarn and is described by way of example. Lines with information about the sections configured as a web and with information about the sections of the fancy yarn configured as an effect alternate with one another in the effect table, in each case, one after the other. The first line of the effect table contains information about a web length and the web thickness. The second line contains information about an effect length and an effect thickness. There then follows a line with a web length and web thickness etc. After listing all the predetermined effects and webs in the predetermined sequence, a so-called yarn repeat of the fancy yarn is present. The summation of all web and effect lengths of the effect table produces the repeat length. In producing the fancy yarn, in accordance with the specification of the first line of the above-described effect table, a web is firstly configured, for example, then an effect according to the specification of the second line of the effect table, followed by a web according to the specification of the third line etc., up to the last line of the effect table. After the last line of the effect table, the cycle starts again with the first line of the effect table. In order to avoid a so-called “image”, after multiple repetition of the yarn repeat with an unchanged first line, a yarn repeat with a changed first line can be inserted. The change may be carried out, for example, in the web length or the effect length. As the next yarn repeat after such a so-called “disturbance”, a yarn repeat with an unchanged original first line is then selected again. The cycle is repeated with sporadically inserted “disturbances” until the predetermined yarn length is wound on the bobbin. The effect configuration, which is determined with the aid of evaluation of the measured diameter values, is compared with the effect configuration which is predetermined by the effect table. The thicknesses and lengths of the effects and webs listed in the effect table in this case form DESIRED values, the correspondence of which with the measured ACTUAL values is checked.
[0014] The continuous measurement of a transverse dimension such as the diameter of the fancy yarn allows an assessment on the basis of quantified properties, as a result of which the comparison can take place in a more targeted and rapid manner compared to a merely qualifying visual assessment. For adaptation to the predetermined configuration of the fancy yarn, changes in the previous data are made. The changing of specific spinning parameters has specific effects on the yarn cross-section. Some parameters can be automatically changed. This is possible, in particular, in the control of the fiber feed to the opening roller by means of control of the draw-in roller. When the draw-in roller temporarily runs more rapidly compared to the rotational speed, which is adjusted to produce a web section, more fiber material is fed per time unit to form the thread. This produces a thicker thread section or an effect. The effect thickness is, in this case, at least approximately proportional to the rotational speed of the draw-in roller. If it is established, for example, that the measured effect thickness is too low, compared with the predetermined effect thickness in the yarn repeat, the rotational speed of the draw-in roller is correspondingly increased. On the other hand, if the measured effect thickness is too great, the rotational speed of the draw-in roller is reduced accordingly. If the evaluation of the measured diameter values of the thread ascertains, for example, that the effect begins too late or the previous web is too long and the length of the effect is therefore not adequate, the beginning of the phase, in which the draw-in roller rotates more rapidly and therefore conveys more fiber material to the opening roller, can be accordingly moved to an earlier point in time. The effect is therefore lengthened. If the effect ends too late and is therefore too long, the end of the phase, in which the draw-in roller rotates more rapidly and therefore conveys more fiber material to the opening roller, can be moved accordingly to an earlier point in time. In the case of deviations of the position, the diameter and the length of the webs, the procedure described above in the case of effects is used.
[0015] Further possibilities for changing spinning parameters are known to the person skilled in the art and these affect the yarn cross-section. Thus, by changing the rotor speed, the rotation of the thread and in association with this, the thickness of the thread, can be influenced. In the case of a higher rotation, the thread is more constricted. The adjustment of the low pressure in the spinning device also influences the effect configuration and can be used as a control variable for the effect configuration. Further possibilities for influencing are offered by the choice of the rotational speed of the opening roller and its configuration, in particular its clothing, or the selection of further spinning means, such as, for example, of the spinning rotor. The combing out performance of the opening roller, influencing the effect, is determined both by the type of clothing and by the peripheral speed of the opening roller. Fluctuations or changes in the fiber feed can be implemented more rapidly with an increased rotational speed of the opening roller or more aggressive clothing, which release more fibers from the fiber sample fed through the draw-in roller. At least the direction, in which a change of the spinning parameters has an effect, is known in each case, so in the event of a deviation from the predetermined configuration of the fancy yarn, a reduction can be made in the deviation. The effects of the change are checked by a renewed comparison, with regard to whether it has led to a reduction in the deviation and whether, and optionally in what direction, further changes are to be made in a next step.
[0016] According to claims 2 and 3 , spinning adjustments are to be taken into account which relate to the basic adjustment of the machine, which do not fluctuate, like the directly effect-related data with the changing transverse dimension of the yarn. Thus, for example, a change in the rotation coefficient can change the thickness of the yarn section. The combing out performance of the opening roller influencing the effect is determined both by the type of clothing and also by the peripheral speed of the opening roller. If such spinning adjustments are included in the comparison process, the possibilities are improved of rapidly reaching optimally selected or adjusted spinning parameters.
[0017] By storing the spinning adjustments after comparison, renewed production of the optimized yarn is possible again at any time, the reproducibility being very good.
[0018] The data to be fed again to the rotor spinning machine is effective for various control mechanisms. The data accordingly contains addresses of control mechanisms, for which it is intended. This leads to the intended allocation of the data when downloading. This also includes data which is only displayed on a display of the central control mechanism. This relates, in particular to data which cannot be implemented by the machine itself. The selection of the spinning means is mentioned by way of example.
[0019] According to further features of the invention, a method for evaluating the measured yarn values is carried out to determine the effects, with the aid of which it is possible to characterize the configuration of the effects produced and to compare these effects with those which are specified, for example, in table form, in an effect table.
[0020] The change to achieve adequate correspondence between the predetermined effect configuration and the effect configuration of the yarn produced advantageously takes place as a control process, which is assisted by the use of control algorithms and empirically determined spinning adjustments, in table form. Both control algorithms and empirically determined spinning adjustments in table form are used to shorten the control process by targeted changes.
[0021] In the method according to the invention, the monitoring of the threads produced is selected as the object. By comparing the effect configuration of the fancy yarn produced with the desired effect configuration predetermined for the yarn, the degree of correspondence or deviation is ascertained. For the further yarn production, ascertained deviations from the desired effect configuration are minimized adequately or completely eliminated by means of the control process. The control process is based on the ACTUAL effect configuration in this case. On the other hand, as in known methods, if only the adherence to the specifications for the feeding of fiber material is monitored, this entails disadvantages. If the fiber material feed, which is supplied for the fancy yarn formation in the form of fiber bands or roving, is controlled without consideration of the ACTUAL effect configuration, other disturbance variables and their effect on the effect formation of the fancy yarn produced are not recognized.
[0022] This defect is avoided in the method according to the invention. The control process is based, in this case, on the ACTUAL effect configuration. Thus every deviation occurring owing to the influence of disturbance variables, of the ACTUAL effect configuration from the desired effect configuration becomes recognizable. An effective control process can be carried out in this manner. When changing the draw-in speed during the feeding of the fiber material or the draw-off speed of the fancy yarn produced, these two speeds are matched to each other in such a way that the effect image corresponds to the desired effect configuration, as a result.
[0023] The method according to the invention will be described with the aid of a rotor spinning machine.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] In the drawings:
[0025] FIG. 1 shows a basic view of a spinning station,
[0026] FIG. 2 shows the opening mechanism of a spinning station in a simplified basic view, in a partial view,
[0027] FIG. 3 shows a basic view of the control, in particular of draw-in rollers of a rotor spinning machine,
[0028] FIG. 4 shows a fancy yarn, which is shown by the placing side by side of measured values of the yarn diameter and
[0029] FIG. 5 is a basic view of a fancy yarn.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] Of the large number of spinning stations of a rotor spinning machine, a single spinning station 1 is shown in side view. At the spinning station 1 , a fiber band 3 is drawn in from a fiber band can 2 through a so-called condenser 4 into the spinning box 5 of the rotor spinning mechanism. The mechanism arranged in the spinning box 5 for isolating the fibers and feeding them into the spinning rotor 6 are known from the prior art and therefore not described in more detail. The drive of the spinning rotor 6 is indicated and consists of a belt 7 running along the machine, with which all the rotors of the spinning stations installed on one longitudinal side of the spinning machine are driven. Nevertheless, single drives of the rotors are alternatively also possible. The belt 7 rests on the rotor shaft 8 of the spinning rotor 6 .
[0031] The thread 9 , which is drawn off by means of the draw-off rollers 11 through the thread draw-off tube 10 is formed in the spinning rotor 6 . The thread 9 then passes a sensor 12 , which is part of a so-called clearer 13 for monitoring the quality of the thread 9 . To recognize a yarn defect, the measured diameters are detected in relation to the thread length passing through. On recognizing a yarn defect, the rotation of the draw-in roller 27 shown in FIG. 2 is stopped, for example, and a thread interruption is thus caused. The thread 9 is guided by a thread guide 14 in such a way that it is wound in cross-wound layers onto a cross-wound bobbin 15 . The cross-wound bobbin 15 is carried by a bobbin holder 16 , which is pivotably mounted on the machine frame. The cross-wound bobbin 15 rests with its periphery on the winding drum 17 and is driven thereby such that the thread 9 is wound in cross-wound layers in cooperation with the thread guide 14 . The rotational directions of the cross-wound bobbin 15 and the winding drum 17 are indicated by arrows. The sensor 12 is connected to a local control unit 20 of the spinning station via the line 18 . The control unit 20 is connected to a central computer 22 of the rotor spinning machine via the line 21 . The stepping motor 23 of the draw-in roller is connected to the control mechanism 25 via the line 24 .
[0032] FIG. 2 shows details of the opening of the fiber band 3 into individual fibers. The fiber band 3 drawn in through the condenser 4 is clamped between the clamping table 26 and the draw-in roller 27 and presented to the rapidly rotating opening roller 28 . The draw-in roller 27 is connected to the stepping motor 23 via the drive connection 29 . The stepping motor 23 can be activated via the line 24 . The direction of rotation of the opening roller 28 is indicated by the arrow 30 .
[0033] The basic structure of a draw-in roller control is shown schematically in FIG. 3 .
[0034] In the present example, the diameter of the presented yarn is measured. As an alternative, for example, the yarn mass could be determined by means of a capacitive sensor instead of an optical one. During determination of the yarn mass, which is generally taken as a basis for the determination of the yarn fineness, the mass of a yarn section passing the measuring region is measured, while during the optical measurement, an average diameter value is determined inside the measuring region. The two measurements are equally suitable for evaluating the effect configuration. In the present example, the invention is described by means of determining the diameter, however.
[0035] Firstly, the configuration of the fancy yarn is input or read into a schematically shown input mechanism 31 and this data is transmitted to a yarn design unit 32 . The transmission is indicated by the arrow 33 . The data required for spinning on a rotor spinning machine are generated in the yarn design unit 32 by means of yarn design software. This data includes both the directly effect-related data, which fluctuates with the changing diameter of the yarn and further data relating to the basic adjustment of the rotor spinning machine. This involves, for example, the rotor, draw-off roller and opening roller speed and the selection of the spinning means. While the latter are preferably retrieved from a table, the rotational speeds are to be determined by corresponding algorithms. These algorithms are based on known interconnections. This involves, for example, the determination of the drawing from the ratio of the rotational speeds of the draw-off rollers to the rotational speed of the draw-in rollers, or of the rotations per meter from the rotor speed in relation to the draw-off speed and the constriction of the fiber assembly connected thereto.
[0036] The data generated in the yarn design unit 32 is transmitted to a central control mechanism 35 of the rotor spinning machine via a bus system 34 . Transmission may also take place alternatively with transportable data carriers, such as, for example, a compact flash card.
[0037] The central control mechanism 35 is connected to the central computer 22 via the data line 36 .
[0038] The control mechanism 25 comprises the control of 24 stepping motors 23 , for example, of the respective draw-in rollers 27 via lines 24 . All 24 winding stations are constructed in the same manner. A control card 40 is connected onto the control mechanism 25 by means of a connection device 39 . The data required to produce fancy yarn is transmitted, for the control of the stepping motors 23 , via a bus system 41 from the central control mechanism 35 to the control card 40 . To produce fancy yarn, the control card 40 converts the data about the thickness and length of the effects and the webs, with adaptation to the other spinning adjustments, into control data for the stepping motors 23 to generate the rotational movement of the draw-in rollers 27 . Via the bus system 42 as a continuation of the bus system 41 , the data required to control the stepping motors of the draw-in rollers is transmitted to further control cards, not shown, which are connected to control mechanisms of further sections of the rotor spinning machine. One of the further control mechanisms is indicated by dashed lines. The further control mechanisms are constructed like the control mechanism 25 , have an identical connection device and a connected, identical control card. Each further control mechanism in each case controls the spinning stations of a section of the rotor spinning machine formed from 24 spinning stations.
[0039] If the stepping motor 23 is activated in such a way that it runs more rapidly, the draw-in roller 27 transports more fiber material to the opening roller 28 . This results in the fact that more fiber material arrives, per time unit, in the rotor 6 and the spun thread becomes thicker. The length of the thick location depends on the duration of the increased fiber feed. The diameter of the thick location depends on the speed of the stepping motor 23 or the draw-in roller 27 .
[0040] The control mechanism 25 is also activated by the central computer 22 via the line 43 , with it being specified via control commands whether the control mechanism 25 controls the production of a fancy yarn or the production of effect-free yarn.
[0041] The freshly spun yarn is measured out by the sensor 12 and the measured values are transmitted to the yarn design unit 32 , which is also provided with a display, not shown, in order to reproduce the current fancy yarn or to quantify deviations from the specification. If the appearance or the statistical description of the freshly spun yarn does not correspond to the predetermined configuration of the fancy yarn, further changes have to be made. These changes may consist both in changing the effect parameters, which are input in the yarn design unit and also in changing machine parameters, which are to be input as a rule at the central computer 22 . For this purpose, control connections 44 are available at the central computer, which, for example, can lead to a control mechanism 45 for the draw-off rollers 11 or a control mechanism 46 for the spinning rotors 6 , the control mechanisms 45 and 46 being formed, for example, by a frequency converter. A display 47 at the central computer also shows the selected spinning means, which, as already mentioned, have a not inconsiderable influence on the configuration of the effects.
[0042] FIG. 4 shows a view of the fancy yarn as a placing side by side of measured values. The effects 48 and webs 49 can be recognized, but the beginning and end of the effects 48 and the effect thickness or the effect diameter D E and the web thickness or the web diameter D ST cannot be seen clearly and therefore not adequately.
[0043] The sensor 12 continuously measures the yarn diameter D and transmits the measured data for evaluation via the central computer 22 to the yarn design unit 32 . The yarn diameter D is recorded in each case after 2 mm of yarn length. A cycle represents a measuring length of 2 mm of yarn. In the view of FIG. 5 , the limit diameter D is shown as a percentage over the yarn length Ls as a curve 10 . The curve 50 represents the web diameter D ST in the view of FIG. 5 , beginning from the left up to the point 51 . From the point 51 , the curve 50 rises and passes the value of the limit diameter D GR at the point 52 . At point 53 , the predetermined yarn length L V1 has been passed through since reaching the point 52 . Since an increase in diameter of 15% is recorded at point 52 and the exceeding of the limit diameter D GR lasts over the predetermined length L V1 , for example, six cycles or 12 mm, the point 52 is defined as the beginning of the effect. The curve 50 falls below the limit diameter D GR at point 54 . The falling below lasts to the point 55 and therefore over the predetermined length L V2 . Therefore, the point 54 is defined as the end of the effect. The effect length L E is determined from the beginning and end of the effect between point 52 and point 54 . An arithmetic average value is formed from the four largest diameters 56 inside the effect. Thus the information about the effect diameter is very largely independent of natural diameter fluctuations in the effect region. This arithmetic average value is defined as the effect diameter D E .
[0044] The yarn clearer 37 continuously determines whether the diameter values of the thread 9 detected by the sensor 12 derive from a region which is defined as a web 49 or as an effect 48 . The fluctuation width Bs designates the spacing between the diameter of the effect 48 and the diameter of the web 49 . If the diameter values of the thread 9 derive from a region, which is defined as a web 49 , these diameter values are compared with the limit values, the limit value RG STO and the limit value RG STU , associated with the web diameter D ST . If the diameter values of the thread 9 derive from a region, which is defined as an effect 48 , these diameter values are compared with the limit values, the limit value RG EO and the limit value RG EO , associated with the effect diameter D E .
[0045] The limit values are selected in such a way that exceeding them signifies an intolerable deviation. An intolerable deviation triggers a change in the spinning parameters. If, for example, an effect does not have the correct dimension, because the thickness of this effect is too low, the thread feed for the phase, in which this effect is formed, is raised by means of an increase in the rotational speed of the draw-in roller and the deviation from the predetermined effect thickness is reduced or eliminated in this manner.
[0046] The yarn clearer 37 can be set up in such a way that, alternatively, either only deviations in the web regions or only deviations in the effect regions are taken into account.
[0047] According to the checking of the diameters of the thread 9 , the web length and the effect length can also be compared with predetermined lengths, without there being an exceeding of diameter limit values, and with the aid of length limit values, a decision can be made as to whether intolerable deviations are present.
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A method which improves the correspondence between the produced fancy yarn and the predetermined configuration of said fancy yarn. The fancy yarn is guided through a sensor device in a spinning device after it is formed and the diameter of the fancy yarn is continuously measured by the sensor device. The fancy configuration of the produced yarn is determined on the basis of the measured values of the diameter and is compared with the predetermined fancy configuration. The comparison is carried out until sufficient correspondence between the predetermined fancy configuration and the fancy configuration of the optimized, produced yarn is achieved.
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BACKGROUND OF THE INVENTION
Field of the Invention and Description of Related Art
[0001] U.S. patent application Ser. No. 11/410,022 of the present applicant relates to a process for obtaining cefotetan of formula
substantially free of the disodium salt tautomer of formula
[0002] This process makes it possible to obtain a substantially pure cefotetan acid, but has the drawback of being rather lenghty and poorly productive: in other words, it is not particularly suitable for industrial application with the production of large batches.
SUMMARY OF THE INVENTION
[0003] The present applicant has therefore sought to devise a simple process which is easy to use and is highly productive. As a result of these efforts, the present inventors have surprisingly found that cefotetan can be recrystallized in pure form, substantially free of tautomer (less than 0.2%), by an easily applied process.
[0004] This process is based on the capacity of the cefotetan tautomer to bind to Al 3+ ions which can be provided in the form of aluminium chloride or as neutral alumina, or even to ions such as Fe 3+ or Cr 3+ (probably by forming stable complexes with the oxygen atoms present on the isothiazole part of the molecule of the tautomer of formula (II) at around pH 7.0, to form a precipitate which is eliminated by filtration, while the cefotetan remains in aqueous solution as alkaline carboxylate.
[0005] A further advantage of the present method is the ease of recovery of the neutral alumina used in the process, so that it can be recycled with considerable cost saving.
[0006] The process of the invention enables cefotetan of formula (I) to be obtained containing up to 0.2% of the tautomer of formula (II) in its acid form and with a K.F. up to 2.5%, concentration on dry basis at least 99.0% and free of solvents, both in the acid form and in the sodium salt obtained from it.
[0007] This process is characterised in that an aqueous solution of crude cefotetan cooled to between 0° and +4° C. is brought into contact with Al 3+ ions originating from a reagent chosen from neutral alumina, anhydrous aluminium trichloride and aluminium trichloride hexahydrate, or with Fe 3+ or Cr 3+ ions, to cause formation of a precipitate with the aforesaid tautomer compound, at pH within the range 7.0-7.2, this precipitate being eliminated by filtration to provide a solution containing cefotetan substantially free of tautomer, from which the cefotetan is precipitated by acidification to pH within the range 1.3-1.5 and isolated by filtration between 0° and +4° C. to provide a substantially tautomer-free cefotetan with a K.F. up to 2.5%, concentration on dry basis at least 99.0% and free of solvents.
DETAILED DESCRIPTION OF THE INVENTION
[0008] The implementation of the process will be more apparent from the ensuing detailed description of a practical embodiment thereof, given by way of non-limiting example.
EXAMPLE 1
Use of Neutral Alumina
[0009] 300 g of wet crude cefotetan originating from synthesis and equivalent to about 80 g of pure cefotetan are suspended in 800 ml of osmotized water. The suspension is cooled to between 0° and +4° C., and 35 g of sodium bicarbonate are added in portions, without exceeding pH 6.8.
[0010] The pH is corrected to 7.0-7.2 with a solution of 8 g sodium bicarbonate in 100 ml of osmotized water. 120 g of neutral alumina are added, and the pH maintained at 7.1-7.2 between 0° and +4° C. by adding carbon dioxide or an 8% sodium bicarbonate solution. The mixture is agitated for 60 min, the pH is corrected to 6.4 with carbon dioxide, and the alumina is filtered off and washed three times with 100 ml osmotized water.
[0011] The pH is corrected to 5.3-5.5 with 5% HCl again at between 0° and +4° C. Agitation is again applied and the cefotetan initially precipitated returns into solution, 1.5 g of decolorizing carbon are added and the mixture agitated at between 0° and +4° C. for 20 min. It is again filtered and the filter washed 3 times with 100 ml of osmotized water.
[0012] The pH of the rich aqueous solution is lowered to 1.3-1.5 by adding 15% HCl at between 0° and +40° C. over about 60 min. The mixture is agitated at between 0° and +4° C. for 40 min, and then filtered under vacuum, washing the filter 3 times with 100 ml of osmotized water, acidified with HCl to a content of about 0.1% and cooled to between 0° and +4° C., then washing twice with 100 ml osmotized water alone, precooled to between 0° and +4° C. About 200 g of wet cefotetan are obtained, which is dried under vacuum at 24°-27° C. under a light stream of nitrogen.
[0013] Yield: 65-70 g of pure cefotetan, K.F. ≦2.5%, concentration on dry basis ≧99.0%, tautomer ≦0.2%, solvent free.
EXAMPLE 2
Use of Anhydrous Aluminium Trichloride
[0014] 60.72 g of wet crude cefotetan, at a concentration of 24,7% and containing between 2.5% and 3.0% of tautomer, are fed into 270 ml of demineralized water between 0° and +5° C. After 20 min of agitation, 12.0 g of potassium bicarbonate are added in 15 minutes still at 0° and +5° C. The mixture is stirred for half hour at 0° and +5° C., complete solubilization is obtained and the pH is stabilized at 7.0.
[0015] The solution is kept under vacuum at between 0° and +5° C. to remove the dissolved carbon dioxide, the pH rising to 7.3-7.4. Draw-off of carbon dioxide under vacuum is continued while maintaining the pH between 7.3 and 7.4 by adding 1N HCl. After about 30 min the solution appears perfectly clear. At this point 2.0 g of anhydrous AlCl 3 are added in small portions of about 0.16 g each, over about half hour while maintaining the temperature between 0° and +5° C. and the pH between 7.3 and 6.6. The additions of anhydrous AlCl 3 and aspiration to remove the carbon dioxide are alternated in order to maintain the pH within the range of 6.6 to 7.3. On termination of the anhydrous AlCl 3 addition the mixture is maintained under agitation and reduced pressure for 45-50 minutes at between 0° and +5° C., the pH being maintained at 6.9-7.1 by small additions of 1N HCl. The pressure is returned to atmospheric, the pH is fixed at 6.9 and the solution filtered between 0° and +5° C. through a porous septum covered with the following layers starting from the bottom: fabric, cotton, celite filter. The reaction solution, maintained between 0° and +5° C., is filtered under minimum vacuum, checking that the pH remains constant between 6.9 and 7.1. The filtered solution is cloudy and is re-filtered through the same filter a further three times without however obtaining a perfectly clear solution. The filter is finally washed with 4×80 ml portions of cold demineralized water. The pH is corrected to 4.5-4.7 with 15% HCl at between 0° and +5° C. 1.5 g of decolorizing carbon and 0.15 g of EDTA are added. The mixture is filtered and the filter washed with 4×40 ml portions of cold demineralized water. 300 ml of methylethylketone are added followed by 50 g of NaCl. The mixture is agitated for 15 min to completely dissolve the salt, then the pH is lowered to 1.5 with 15% HCl at between 0° and +5° C. The phases are separated after at least 20 min at between 0° and +5° C., then 150 ml of methylethylketone and 50 g of sodium chloride are added to the aqueous phase. When the salt has dissolved, the pH is checked to be ≦1.5, the temperature is raised to 20° C. and the phases allowed to separate for at least 30 min. The two organic phases are pooled, decolorized with 1.5 g of carbon for 15 min, filtered and the filter washed 3 times with 25 ml methylethylketone. The decolorized organic solution is concentrated to 260-280 ml by distilling off the methylethylketone under reduced pressure at 30°-31° C. 320 ml demineralized water are added, the mixture cooled to between 0° and +5° C. and 4.4 g of potassium bicarbonate added under agitation while maintaining the pH between 6.0 and 6.5, and in any event ≦6.5. The phases are separated and the organic phase discarded, while the aqueous phase is corrected to pH 4.5-4.7 with 5% HCl. The aqueous phase is decolorized with 1.0 g carbon at between 0° and +5° C. and maintained under reduced pressure for 20 min. The mixture is filtered, the filter washed twice with 40 ml demineralized water, the system returned to atmospheric pressure and the pH corrected to 3.6-3.7 with 5% HCl at between 0° and +5° C. The temperature is raised to 20° C., the methylethylketone which has remained dissolved is distilled off under reduced pressure, a crystal of pure cefotetan is added and the mixture left to crystallize for 45 min at pH 3.6-3.7, while maintaining reduced pressure to remove further methylethylketone which may be present. Atmospheric pressure is restored and 5% HCl dripped in over 15 min until pH 3.0.
[0016] Reduced pressure is again applied and the mixture heated to 30° C., the pH then being lowered to 2.5 with 5% HCl over 15 min. The operation is repeated to reduce the pH firstly to 2.0 and then to 1.5 with 5% HCl, each time returning to reduced pressure at 30° C., until pH 1.5 remains constant for 30 min. The mixture is cooled to between 0° and +5° C. and agitated for 60 min under reduced pressure. Atmospheric pressure is restored, the mixture filtered, the filter washed with 61 ml of 1% HCl at between 0° and +5° C., then with 61 ml of demineralized water at the same temperature.
[0017] On drying, 11.0 g of cefotetan are obtained with a concentration on dry basis ≧99.0% and with tautomer ≦0.2%, K.F. <2.5%.
[0018] The same results are obtained on using aluminium trichloride hexahydrate in a quantity equivalent to the anhydrous aluminium trichloride of the aforedescribed example.
EXAMPLE 3
Recovery of Spent Alumina
[0019] To recover the spent neutral alumina the wet neutral alumina originating from 240 kg of virgin neutral alumina is loaded into a comber filter. A solution of 40 kg of 30% soda in 1000 l of demineralized water is eluted at ≦20° C. Nitrogen is blown into the filter for drying purposes and elution is repeated with a further 40 kg of 30% sodium hydroxide in 1000 l demineralized water. When the last fraction is colourless, elution is carried out with at least 10000 l of demineralized water to a pH between 8 and 9.
[0020] The regenerated alumina is suspended in 1000 l of demineralized water at a temperature of ≦20° C. Agitation is applied and the pH corrected to 6.7-7.3 with 5% HCl until constant pH within this range. The mixture is filtered, and washed with at least 1000 l of demineralized water in portions, until the last wash presents a conductivity <500 microSiemens (μS).
[0021] 310-320 kg of wet product are recovered, corresponding to 220-230 kg of dry neutral alumina.
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The invention relates to a method for obtaining cefotetan acid substantially free of tautomer, by treating crude cefotetan with Al 3+ ions which cause the tautomer to precipitate. The precipitate is eliminated by filtration to provide a solution from which practically tautomer-free cefotetan is obtained.
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This application is a continuation in part of U.S. patent application Ser. No. 08/281,620 filed Jul. 28, 1994 from which priority is claimed.
FIELD OF INVENTION
This invention relates to a mounting system for a closure member in an assembly and improvements thereof which allows the secure sliding and subsequent pivoting of the closure member from a position parallel to the assembly, wherein sliding of the closure member is allowed, to a fully pivoted position. The invention is preferably embodied in a window assembly but finds application also in large pivoting windows and patio doors.
BACKGROUND OF THE INVENTION
Double hung windows are well known in the art. There are a multiplicity of examples of such double hung windows which incorporate window frames for the sliding of a window sash within a jamb guide. Further there are many examples within the prior art which allow for the sliding of a window sash within a frame within the jamb channels thereof which further incorporate a carrier or shoe attached to the window sash which allows for the pivoting of the window sash away from the window frame.
A multiplicity of designs for sliding patio doors further exist within the prior art. A typical patio door is made up of one stationary framed main glass panel and one moveable framed main glass panel sliding in a horizontal direction adjacent the stationary panel and which does not typically pivot. The weight of the patio door would require a substantial device in order to allow for the secured pivoting thereof. Such hardware would further eliminate or minimize the door sagging out of position and the need for realignment of the doors when pivoted back to the closed position. The pivoting of patio doors would be quite attractive and would allow for the marketing of large French type doors in the industry. No such doors exist within the market place at the present time.
Further within the prior art there is taught a tilt slider and the hardware therefore as taught in U.S. Pat. No. 4,888,915 issued Dec. 26, 1989, U.S. Pat. No. 5,168,665 and co-pending application 07/677,135 filed Mar. 29, 1991 manufactured and distributed by Canadian Thermo Windows, whose office is in Toronto, Canada. The manufacture of tilt and slide windows, double hung windows, patio doors, and similar structures according to the teachings of the above mentioned three references obviated many of the prior art problems which will generally occur when any pivot block provided at the pivoting end of the window sash moves out of alignment in relation to the upper or lower pivot block adjacent the same lineal of the closure member. The only means for securing the sash of the window to the pivot block previously has been either a pin or strut. The continuing motion and sliding of the windows back and forth and the pivoting thereof causes the windows to misalign and sag under the weight of gravity especially when manufactured in a vertical tilt slider. U.S. Pat. No. 4,888,915 and the above mentioned other references overcame this problem by an improved bracing system of the closure in the closure assembly by interconnecting the shoes in a carrier assembly and including with some embodiments a braking mechanism to ensure the window cannot slide when pivoted or a locking mechanism to ensure that the window cannot pivot when sliding in a track. In this way parallelism of the pivots whether stationary or in motion was assured by the required locking of the closure member. Such an assembly although much improved over the prior art has the drawback of requiring the user to latch and unlatch a number of levers to operate the window in its various modes of operation. This is primarily necessary to ensure that the pivots stay substantially parallel at all times so that for example the window is locked while pivoting thereby ensuring parallelism, or that the window is locked in the track while sliding also ensuring through the interconnection of the shoes a constant spacing and hence substantially parallel running as well. It is therefore desirable to eliminate as much of the consumer interaction with the window assembly as possible and make the operation as simple and fool proof as possible.
Nowhere within the prior art is such a simplified improved device provided which allows for the manufacture of heavier windows and doors in larger sections without the sagging of the window and having reliable operating pivots incorporated in the assembly which both allows for the pivoting and sliding of the window by the user without the need for a multiplicity of user operated locks and latches.
Further in the manufacture of casement type windows there is found a large number of links and levers depending on the manufacturer of the window assembly. This renders the assembly costly to manufacture because of the assembly labour required. Further with protruding handles the window is prone to being damaged when shipped. One of the problems with known casement assemblies is that they are difficult to clean on the outside. U.S. Pat. No. 1,600,796 to Campbell addressed this concern. Further U.S. Pat. No. 1,341,366 endeavored to address this concern for casement windows. Final U.S. Pat. No. 5,289,656 attempted to improve on these previous structures. However the systems do not provide for ease of installation and variation in the window or door size which may be supported. Further the opening of the casement style windows provided to clean the outside of the window is insufficient to provide for all sizes of individuals and reaches.
It is therefore an object of this invention to overcome many of the deficiencies in the prior art stated above which allows for smooth and simple operation of a closure member which is capable of both sliding within a guide channel and tilting upon a pivot assembly thereof.
It is a further object of this invention to overcome many of the deficiencies in the prior art stated above which allows for smooth and simple operation and assembly of a casement style window which is capable of both pivoting to an open position, and allowing the pivoting end to slide within a guide channel to the opposite side of the frame within which the sash normally pivots for easy cleaning thereof.
It is a further object of the invention to provide casement windows of appropriate size and construction to replace existing double hung and/or tilt and slide windows.
It is a further object of the invention to provide a reliable carriage for use in relation to a guide channel disposed within a frame for a closure member and improvements therefore, whereby locking of the pivot when the closure member is rotated is unnecessary to maintain parallelism of the structure.
Further and other objects of this invention will become apparent to a man skilled in the art when considering the following summary of the invention and the more detailed description of the preferred embodiments illustrated herein.
SUMMARY OF THE INVENTION
According to one aspect of the invention, there is provided a closure assembly having two ends comprising a first and second track disposed proximate each end of the assembly respectively, and a slidable and pivotable closure member, the closure member including framing sections there for and being engaged with the first and second tracks proximate first and second pivots adjacent the pivotable end of the member, the first and second pivots being interconnected by a multiple segment shaft disposed within framing sections of said closure member, (for example the shaft including at least two portions and preferably being telescoping), the shaft providing for accurate installation, retention, removal, adjustment and alignment of the first and second pivots within the first and second tracks in a substantially parallel line with respect to one another and for pivotally supporting the closure member which may be safely and securely pivoted away from the closure assembly, whereby the first and second interconnected pivots are adapted to remain engaged with the first and second tracks while supporting the closure member both when it is pivoted away from the closure assembly and when it is slidable relative to the track.
In one embodiment the closure assembly may further comprise a carrier traveling within said each of said first and second tracks and having interconnected first and second portions, disposed within each of said first and second tracks the first portion being engaged with the first and second pivots of the closure member and the second portion being spaced from the first portion within each of the first and second tracks the carrier to further assist sliding movement and pivoting movement of the closure member and preferably wherein the distance between said interconnected first and second portions is adjustable.
Preferably the first portion of the carrier traveling within each of said first and second tracks further comprises an opening within which the first or second pivots are disposed to cooperate with the first portion. Preferably the first and second pivots portions may further comprise a rotatable pinion disposed therewith for facilitating the movement of the carrier relative to each of the first and second tracks preferably in cooperation with a rack disposed with each of said first and second tracks. Preferably the closure member may further comprise latching means for latching the closure member in relation to the carrier to prevent pivoting of the closure member when the closure member is slidable relative to the tracks, and preferably wherein the latching means is a central locking member disposed with the framing sections of the closure member.
According to another aspect of the invention, there is provided a pivoting and sliding closure assembly comprising:
i) an opening extending within a frame
ii) the frame having two ends and having disposed therein or attached thereto proximate each track portions extending in a substantially parallel direction to the extensions of said ends of said frame;
iii) at least one closure member having framing portions and two ends and being slidable within said track portions and pivotable proximate at least one end thereof and latchable in the track portions proximate the other end thereof;
iv) each of said track portions having disposed therein at least two pivot shoes adjacent the pivoting end of the closure member, each shoe being substantially compatibly shaped with the track portions and having a top and bottom, (preferably having rolling means disposed adjacent the bottom thereof for assisting the movement of the pivot shoe), each shoe having disposed therein adjacent the pivoting end of the at least one closure member an opening extending from the top toward the bottom of the shoe wherein pivot means are disposed, said pivot means provided with said pivot shoes being interconnected by a multiple segment shaft disposed within said framing portions of said at least one closure member, (for example the shaft including at least two portions and preferably being telescoping) the shaft providing, for accurate installation, retention, removal, adjustment and alignment of the first and second pivots within the track portions in a substantially parallel line for pivotally supporting the at least one closure member for safe and secure pivoting away from the closure assembly;
v) the at least one closure member having latching means provided therewith for latching the at least one closure member in relation to the track portions to prevent the at least one closure member from pivoting upon the pivot means when the at least one closure member remains slidable with said track portions; and preferably the latching means is a central locking member disposed with the framing portions of the at least one closure member.
vi) the at least one closure member being braced by the multiple segment shaft interconnecting the pivot means disposed with each track portions, the substantially parallel alignment of the pivot means provided by the multiple segment shaft preventing the pivot means from misaligning and/or disengaging from the relevant track portions when the at least one closure member is rotated to an open position and/or when it remains slidable within said track. Preferably the pivot means may further comprise a rotatable pinion for facilitating the movement thereof relative to the track preferably in cooperation with a rack disposed with said track.
Preferably said closure member may further comprise a window sash being a casement, double hung, or tilt and slide installation or, a door or a patio door.
According to another aspect of the invention, there is provided a pivoting and sliding closure assembly comprising:
i) an opening extending within a peripheral frame said peripheral frame including a header portion, a sill portion and two vertically extending jamb portions;
ii) the sill and header portions or the two jamb portions having disposed therein or attached thereto track portions extending in a substantially parallel direction to the extensions of said peripheral frame portions;
iii) at least one closure member having two ends and framing portions and being slidable within said track portions and pivotable proximate at least one end thereof and latchable in the track portions proximate the other end thereof;
iv) each of each track portions having disposed therein adjacent the pivoting end of the at least one closure member at least two pivot shoes, each pivot shoe being substantially compatibly shaped with the track portions and having a top and bottom (preferably having rolling means disposed therein proximate the bottom thereof for assisting the movement of the pivot shoe), each pivot shoe having disposed therein adjacent the pivoting end of the at least one closure member an opening extending from the top toward the bottom of the shoe wherein pivot means are disposed, said pivot means being interconnected by a multiple segment shaft disposed within the said framing portions of said at least one closure member, (for example the shaft including at least two portions and preferably being telescoping), the shaft providing for accurate installation, retention, removal, adjustment and alignment of the pivot means in a substantially parallel line for pivotally supporting the at least one closure member for safe and secure pivoting away from the at least one closure assembly;
v) the at least one closure member having latching means provided therewith for latching the at least one closure member in relation to the track portions to prevent the at least one closure member from pivoting upon its pivot means when the at least one closure member remains slidable with said track portions; and preferably wherein the latching means is a central locking member disposed with the closure member;
vi) the at least one closure member being braced by the multiple segment shaft which provides for accurate installation, retention, removal, adjustment and alignment of the interconnected pivot means disposed with each track, portion the substantially parallel line of the pivot means provided by the multiple segment shaft preventing the at least one closure member from misaligning and/or disengaging from the relevant track portion when rotated to an open position or when the at least one closure member remains slidable within said track portions. In one embodiment said at least one closure member is a window sash being a casement, double hung, or tilt and slide installation. In another embodiment said closure member is a door and preferably a patio door. Preferably the pivot means may further comprise a rotatable pinion for facilitating the movement of the at least one closure member relative to the track, preferably the pinion cooperating with a rack disposed with said track portions.
According to yet another aspect of the invention there is provided for use in a pivoting and sliding closure assembly, a closure member slidable within a guiding channel and pivotable therefrom, the closure member having a substantially rectangular frame having a top and bottom, and having engaged at its top and bottom, proximate one end of the closure member, pivots for engaging a first and second shoe, and having disposed at the other end of the closure member proximate its top and bottom, user accessible means for engaging the guiding channel (preferably wherein said user accessible means is a central lock);
said shoes being slidable in said guiding channel and comprising a substantially rectangular body having a top and bottom (preferably made from thermoplastic material) and preferably having disposed proximate the bottom thereof at least one roller or wheel), said shoes having disposed therewith pivot means (preferably the pivot means may further comprise a rotatable pinion for facilitating the movement of the shoes relative to the track preferably in cooperation with a rack disposed with said track) the rotatable pinion for engagement engage with the shoes, said pivot means being interconnected by a multiple segment shaft disposed within said frame (for example at least two portions and preferably telescoping), which provides for accurate installation, retention, removal, adjustment and alignment of the pivot means with said track portions, each shoe having an opening for said pivot means, the opening extending from proximate the top towards the bottom of said shoe, whereby when the closure member pivots upon the pivot means away from the guide channel it is braced from misalignment by the multiple segment shaft for (for and by the interconnected pivot means disposed with each channel, the substantially parallel line of the pivots being provided by the multiple segment shaft when the closure member is rotated to an open position or when it remains slidable within said track. In one embodiment said closure member is a window sash being a casement, double hung, or tilt and slide installation. In another embodiment said closure member is a door and preferably a patio door.
According to another aspect of the invention, there is provided a closure assembly comprising a track and a slidable and pivotable closure member, the closure member being engaged with the track proximate first and second pivots adjacent a pivotable end of the closure member, the first and second pivots being connected by a cable system connecting the upper and lower pivots to move in and be maintained in substantially parallel positions at all times to retain and align the first and second pivots in a substantially parallel line for pivotally supporting the closure member so that it may be safely and securely pivoted away from the closure assembly, whereby the first and second connected pivots are adapted to remain engaged with the track while supporting the closure member both when it is pivoted away from the closure assembly and when it is slidable relative to the track.
According to another aspect of the invention, there is provided hardware for a closure assembly having a track and a slidable and pivotable closure member, the closure member having framing portions and being engaged with the track proximate first and second pivots adjacent the pivotable end of the member, the hardware comprising the first and second pivots being interconnected by a multiple segment shaft disposed within the framing portions of said closure member in use, (for example at least two portions and preferably telescoping), the shaft providing for accurate installation, retention, removal, adjustment and alignment of the first and second pivots in a substantially parallel line for pivotally supporting the closure member so that it may be safely and securely pivoted away from the closure assembly, whereby the first and second interconnected pivots are adapted in use to remain engaged with the track while supporting the closure member both when it is pivoted away from the closure assembly and when it is slidable relative to the track.
According to another aspect of the invention, there is provided hardware for a closure assembly having a track and a slidable and pivotable closure member, the closure member being engaged with the track proximate first and second pivots adjacent the pivotable end of the member, the hardware comprising the first and second pivots being connected by a cable system connecting the upper and lower pivots to move in and be maintained in substantially parallel positions at all times to retain and align the first and second pivots in a substantially parallel line for pivotally supporting the closure member so that it may be safely and securely pivoted away from the closure assembly, whereby the first and second connected pivots are adapted to remain engaged with the track while supporting the closure member both when it is pivoted away from the closure assembly and when it is slidable relative to the track.
According to yet another aspect of the invention there is provided a resiliently biased lock and handle which normally locks the shaft of any of the aforementioned embodiments in operation until the handle is operated by a user wherein the lock unlocks the shaft and allows the shaft to rotate, and when the handle is released again said lock locks the shaft, allowing for continuous locking of the window at any position.
In an embodiment of the aforementioned invention in the preceding paragraphs when embodied in a tilt and slide or double hung window the inside rack portions provided within the track of the assembly, which extend the full width of the frame, curve towards the stationary closed position for the window assembly and provide a closed window assembly in which both sashes are oriented in a straight line.
In an embodiment of the aforementioned invention in the preceding paragraphs when embodied in a tilt and slide, casement or double hung window a retractable screen is provided disposed within the or jamb of the assembly which accumulates on and pays out from a spring biased roll disposed within said header or jamb, the screen being retractable for egress or cleaning purposes, and available as desired by providing a detent on the opposite jamb engageable with the screen when in its operatable position.
In an embodiment of the aforementioned invention in the preceding paragraphs when embodied in a casement window a link having two ends is fastened at one end proximate the center of the bottom of the window sash and proximate the other end of the link adjacent the end of the sill of the window frame to allow for full operation of the casement window from a fully closed to a fully open position and the movement of the pivoting end of the window towards the opposite end so as to allow full access to the outside of the window and the easy cleaning thereof. In another embodiment the link is removable to allow total reversing of the window for cleaning and/or removal purposes.
In another embodiment of the invention the rack disposed with the track is made from aluminum and formed in three separate steps so as to minimize the amount of vertical creeping of the rack when formed. The rack also acts as a liner to distribute the load of the sash and minimize distortion of the vinyl preferred extrusions.
According to the following improvements of the invention reference is made to the previous structures described substantially in the first eleven paragraphs of this disclosure. Whenever reference is made below to the structures or inventions of the "above mentioned paragraphs" or "described above" or the like its is intended to refer the reader primarily from the paragraphs for the following improvements to the summary of inventions above and to improvements to the structures described therein as defined by the sections immediately following this paragraph.
According to yet another aspect of the invention there is provided a closure assembly comprising a track and a slidable and pivotable closure member, the closure member being engaged with the track proximate first and second pivots adjacent the pivotable end of the member, the first and second pivots being interconnected by a multiple segment shaft (for example at least two portions) (for example telescoping) which provides for accurate installation, retention, removal, adjustment and alignment of the first and second pivots in a substantially parallel line for pivotally supporting the closure member so that it may be safely and securely pivoted away from the closure assembly, whereby the first and second interconnected pivots are adapted to remain engaged with the track while supporting the closure member both when it is pivoted away from the closure assembly and when it is slidable relative to the track. Preferably the first and second pivot portions further comprise a rotatable pinion disposed therewith for facilitating the movement of the carrier relative to the track. In a preferred embodiment wherein the rotatable pinion moves in cooperation with a rack disposed with said track. The closure assembly may further comprise a window sash being a casement, double hung, or tilt and slide installation or, a door or a patio door.
According to yet another aspect of the invention there is provided a pivoting and sliding closure assembly comprising:
i) an opening extending within a frame
ii) the frame having disposed therein or attached thereto a first and second track portion extending in a substantially parallel direction to the extensions of said frame portions;
iii) at least one closure member slidable within said track portions and pivotable proximate at least one end thereof and latchable in the tracks at the other end thereof;
iv) each track portions having disposed therein a pivot shoe adjacent the pivoting end of the closure member, said shoe being substantially compatibly shaped with the track and having a top and bottom, (preferably having rolling means disposed therein for assisting the movement of the pivot shoe in the track), the shoe having disposed therein an opening extending from the top toward the bottom of the shoe wherein pivot means are disposed, said pivot means of said shoe disposed with said first track portion being interconnected with the pivot means of the shoe in the second track portion by a multiple segment shaft (for example at least two portions) (for example telescoping) which provides for accurate installation, retention, removal, adjustment and alignment of the first and second pivots in a substantially parallel line for pivotally supporting the closure member for safe and secure pivoting away from the closure assembly;
v) the closure member having latching means provided therewith for latching the at least one closure member in relation to the track to prevent the closure member from pivoting upon its pivot means when the closure member remains slidable with said track
vi) the at least one closure member being braced from sagging by the multiple segment shaft interconnecting the pivots disposed with the pivot shoe of each track, the substantially parallel line of the pivots provided by the a multiple segment shaft preventing the pivots from sagging and/or disengaging from the relevant track when the at least one closure member is rotated to an open position and/or when it remains slidable within said track. Preferably the pivots further comprise a rotatable pinion for facilitating the movement of the shoe or carrier relative to the track. In one embodiment the pinion moves in cooperation with a rack disposed with said track. The closure assembly may further comprise a window sash being a casement, double hung, or tilt and slide installation or, a door or a patio door.
According to still yet another embodiment of the invention there is provided a pivoting and sliding closure assembly comprising:
i) an opening extending within a peripheral frame said peripheral frame including a header portion, a sill portion and two vertically extending jamb portions;
ii) the sill and header portions or the two jamb portions having disposed therein or attached thereto first and second track portions extending in a substantially parallel direction to the extensions of said peripheral frame portions;
iii) at least one closure member slidable within said track portions and pivotable at least one end thereof and latchable in the track at the other end thereof;
iv) each track portions having disposed therein a pivot shoe adjacent the pivoting end of the closure member, said shoe being substantially compatibly shaped with the track and having a top and bottom, (preferably having rolling means disposed therein for assisting the movement of the pivot shoe), said shoe having disposed therein an opening extending from proximate the top toward the bottom of the carrier wherein pivot means are disposed, said pivot means for said shoes disposed within said first and second tracks being interconnected by a multiple segment shaft (for example at least two portions) (for example telescoping) which provides for accurate installation, retention, removal, adjustment and alignment of the pivots in a substantially parallel line for pivotally supporting the closure member for safe and secure pivoting away from the closure assembly;
v) the closure member having latching means provided therewith for latching the at least one closure member in relation to the track to prevent the closure member from pivoting upon its pivot means when the closure member remains slidable with said track;
vi) the at least one closure member being braced from sagging by the multiple segment shaft (for example at least two portions) (for example telescoping) which provides for accurate installation, retention, removal, adjustment and alignment interconnecting the pivot means disposed with each track, the substantially parallel line of the pivots provided by the multiple segment shaft preventing the closure member from sagging and/or disengaging from the relevant track when rotated to an open position or when it remains slidable within said track. In one embodiment said closure member is a window sash being a casement installation. In another embodiment the closure member is a window sash being a double hung, or tilt and slide installation. Preferably the pivots further comprise a rotatable pinion for facilitating the movement of the carrier relative to the track, and in one embodiment wherein said pinions move in cooperation with a rack disposed with said track.
According to yet another aspect of the invention there is provided for use in a pivoting and sliding closure assembly, a closure member slidable within a guiding channel and pivotable therefrom, the closure member having a substantially rectangular frame having a top and bottom, and having engaged at its top and bottom proximate one end pivots for engaging a first and second shoe, and having disposed at the other end thereof proximate its top and bottom user accessible means for engaging the guiding channel (preferably wherein said user accessible means is a central lock); said shoes being slidable in said guiding channel and comprising a substantially rectangular body having a top and bottom (preferably made from thermoplastic material) and preferably having disposed proximate the bottom thereof at least one roller or wheel), said shoes having disposed therewith pivot means (preferably the pivot means may further comprise a rotatable pinion for facilitating the movement of the shoe relative to a track provided with said guiding channel and preferably in cooperation with a rack disposed with said track) to engage with the shoes, said pivot means being interconnected by a multiple segment shaft (for example at least two portions) (for example telescoping) which provides for accurate installation, retention, removal, adjustment and alignment of the pivot means, each shoe having an opening for said pivot means, the opening extending from proximate the top towards the bottom of said shoe, whereby the closure member upon the pivot means pivoting away from the guide channel is braced from sagging by the a multiple segment shaft (for example at least two portions) (for example telescoping) which provides for accurate installation, retention, removal, adjustment and alignment and interconnecting of the pivot means disposed with each channel, the substantially parallel line of the pivots provided by the multiple segment shaft (for example at least two portions) (for example telescoping) preventing the closure member from sagging and/or disengaging from the relevant track when rotated to an open position or when it remains slidable within said track. In one embodiment the pivot means further comprises a rotatable pinion for facilitating the movement of the carrier relative to the track and preferably wherein said pinion moves in cooperation with a rack disposed with said track.
According to yet another aspect of the invention there is provided hardware for a closure assembly having a track and a slidable and pivotable closure member, the closure member being engaged with the track proximate first and second pivots adjacent the pivotable end of the member, the hardware comprising the first and second pivots being interconnected by a multiple segment shaft (for example at least two portions) (for example telescoping) which provides for accurate installation, retention, removal, adjustment and alignment of the first and second pivots in a substantially parallel line for pivotally supporting the closure member so that it may be safely and securely pivoted away from the closure assembly, whereby the first and second interconnected pivots are adapted in use to remain engaged with the track while supporting the closure member both when it is pivoted away from the closure assembly and when it is slidable relative to the track.
Preferably the hardware may be embodied in a casement window wherein a link having two ends is fastened at one end proximate the center of the bottom of the window sash and proximate the other end adjacent the end of the sill of the window frame to allow for full operation of the casement window from a fully closed to a fully open position and the movement of the pivoting end of the window towards the opposite end so as to allow full access to the outside of the window and the easy cleaning thereof. In another embodiment the link is removable to allow total reversing of the window for cleaning and/or removal purposes.
In other embodiments the inventions described in the last six paragraphs may be embodied in a tilt and slide, casement or double hung window wherein a retractable screen is provided disposed within the jamb of the assembly which accumulates on and pays out from a spring biased roll disposed within said jamb, the screen being retractable for egress or cleaning purposes, and available as desired by providing a detent on the opposite jamb engageable with the screen when in its extended position.
According to another aspect of the invention, the inventions described in the last six paragraphs the rack disposed with the track is made from aluminum and formed in three separate steps so as to minimize the amount of vertical creeping of the rack when formed and preferably wherein the rack also acts as a liner to distribute the load of the sash and minimize distortion of the vinyl track.
In a preferred embodiment of the invention described above, the frame portions, for example the headers, vertical jambs or sills are formed separately from the track. The track includes an integral rack portion proximate one side thereof, said rack portion including a plurality of teeth extending substantially from end to end of said track, and for engagement with the rotatable pinion of said carrier which facilitates the movement of the carrier relative to the track. The track is fixed in position relative to the headers, sills and/or jambs by the provision of two supplementary portions. The first supplementary portion is a block which has two ends, a top and a bottom, the block having disposed in use proximate the top thereof at least one opening to receive fasteners, the at least one opening extend to the bottom of the block. The fasteners are for engagement with the frame portion and preferably wooden base portions disposed within the frame and are provided to lock the first block in position in relation to the end of the track remote the pivoting end of the closure member, and thereby fixing the track in position. The first block has disposed therewith an adjuster moveable in relation to said block in a direction extending towards said track and preferably rotatable, said adjuster being engageable with a second supplementary portion, and preferably a nut portion having track shaped abutting portions proximate one side thereof, and for engagement with said track. The second portion has elements provided therewith which are engageable with said adjuster and said track, said adjuster being moveable in position to move the track abutting portions in relation to the rack provided with the track, wherein movement of said adjuster will move said second portion and preferably said nut in relation to said track and said rack in a direction toward and away from the block thereby adjusting the position of said track in relation to said frame portions and thereat fixing said rack in position. The main advantage of providing such an adjustment for the track is to establish and allow for the alignment or adjustment of the closure member and to maintain the parallelism of the carrier in relation to for example both a bottom and a top track in the case of a tilt and slide or casement window, or the left and right side in the case of a double hung widow, so that the pivots remain substantially parallel and square to one another. Aluminum is preferably used for the track since it is able to take the weight of the window more readily than vinyl or other plastic material. The track may be formed from the previously mentioned three separate steps so as to minimize the amount of vertical creeping of the rack when formed. In a preferred embodiment, the adjuster is a rotatable cap screw preferably having an opening therein for an alien key, and which is contained within an opening proximate one end of the first block remote the track and wherein said cap screw is threaded into the second block or preferred nut, wherein rotation of the screw in relation to the fixed block, for example by an allen key, will cause the second block or preferred nut to move fore and aft in relation to the track and provide for a final adjustment or readjustment of the track in relation to the carrier in both the top and bottom or side tracks of the window system depending on what window system is used. Preferably the block is manufactured from aluminum, and the adjuster nut is manufactured from Delrin(™). In another embodiment, the block and nut are manufactured from fiber filled nylon. In a preferred embodiment of the invention, both the first block and second nut further comprise a detent, for example a right angled triangle notch proximate the top thereof for engagement with a lock in use for a pivoting window, the lock being compatible with the detent. The blocks therefore provide a reinforced portion of the window frame against which the lock may abut in use. Otherwise the lock would engage only a vinyl flange of the sill or header for example, and the window load may in time tear or distort said flange to render it useless.
In another a preferred embodiment of the invention, the rack formed integral with the track further comprises an upstanding flange disposed proximate one side of the track wherein the rack is disposed having a plurality of teeth for engagement with the pinion gear of the carrier or shoe. Preferably the rack is formed by a three-step process to minimize the amount of vertical creeping of the preferred aluminum material. Preferably the carrier is a pivot shoe provided for engagement with said rack and track and further comprising a carrier having a top and a bottom, the carrier having disposed proximate the bottom thereof means, and preferably slots, for retaining rollers, and the rollers in use thereof for providing the smooth movement of the shoe within the track, preferably the rollers being engaged with a predetermined channel formed in said track, said carrier also having an opening disposed proximate the top thereof wherein a pivot gear is disposed, said pivot gear having a top and a bottom and having disposed primate the top thereof a pivot engaging portion for engaging the pivot of a closure member such as a window sash, said pivot gear having disposed proximate the bottom thereof an anti-thrusting wheel portion for engagement with a shoulder provided proximate each side of the track channel, for example to engage the shoulder of the channel as a result of thrust which may be caused by the wind load on the closure member and the normal thrust caused by meshing of gears, the anti-thrusting wheel preferably being of a predetermined diameter of a dimension less than the channel of the track so as to minimize drag in the track, said pivot gear having disposed intermediate said pivot engaging portion and said anti-thrust wheel portion a pinion gear portion for engaging the rack, wherein the previously described closure member and specifically the pivots thereof engages with the carrier portion, wherein movement of said carrier portion will affect rotation of said pinion in relation to said track and the smooth movement of the carrier along the track maintaining the parallelism, of said upper and lower pinions for the case of both a tilt and slide and casement window, and said left and right pinions in the case of double hung windows. Preferably said carrier portion is made from Delrin(™), and said pivot gear portion is made from nylon. The anti-thrust wheel portion is provided to engage the shoulders provided adjacent the recess of the track to accommodate any thrusting of the pinion which might occur, due to wind loading or the like and the rotation of the gears, and to maintain the pinion substantially central in relation to the carrier at all times. The rollers provided proximate the bottom of said carrier are to ensure smooth movement of the carrier in relation to the track. Preferably the rollers are made from metal.
In another preferred embodiment of the invention, the vinyl profile forming the closure member (for example a sash profile) may further comprise a cover disposed on the side of the profile opposite the glass, which cover extends substantially along the length of the profile and which has disposed proximate the sides thereof two flanges for locking engagement underneath flanges provided with the profile, said profile further including a space defined within said profile enclosed by said plastic cover, preferably said space containing in use a closed cell foam or the like, for example a closed cell caulking foam, which is compressible, said plastic cover having disposed proximate the bottom thereof intermediate said flanges spring-loaded members, for example fingers, engageable with said foam, and preferably when installed slightly loading said foam to create a spring biased resistance of the foam against the cover further locking the cover in position with the profile. Preferably the cover is made from thermoplastic or thermoset material and when installed extends down from said profile toward the space defined within said track portion between the flanges thereof. The cover provides a locking flexible seal throughout the length of the closure member with the exception of the area adjacent the carrier portion located proximate the pivoting end of said closure member. In various embodiments of the invention, the cover may be embodied with a casement window, a tilt and slide window and a double-hung window. The use of a closed cell foam such as caulking foam or the like in the space within the profile provides resilience and strength to the cover along the length of the profile and therefore allows for the foam and cover together to provide a surface upon which the closure member may travel while the carrier moves in the track. Also, the cover behaves as a seal for the profile and in use indirectly for the track to keep dust and other undesirable elements out of the track and out of the profile, and assists to prevent passing cold air.
According to yet another aspect of the invention and in a preferred embodiment thereof, there is provided a release mechanism for locking a closure member from pivoting movement in a closure assembly, the closure member being carried by the carrier described in the above paragraphs, said release mechanism further comprising operating means disposed with the closure member, and preferably with the window sash elements, said operating means may be provided intermediate the lockable ends of the closure member, and accessible to the user. For example, when the closure member is provided within a tilt and slide window, the operating means will generally be disposed in a vertical plane provided with a vertical sash element so that the operating member when operated will cause the locking and unlocking of the tilt and slide window and allow free movement thereof. When the operating means is provided in a double-hung window, the operating means may be a handle disposed in a horizontal plane and being operable by the user to and from a locked and released position to allow movement of the double-hung window, for example, pivoting thereof to access the exterior pane surface and provide cleaning thereof. In another embodiment when the closure member is a casement window sash, the operating member may be disposed in a substantially vertical direction and is operable by the user to and from a locked and unlocked position, the operating means being user operable to and from a first locked position and a second unlocked position. In all cases, bi-directional locking means are provided with the sash profile and being moveable by the operation of said operating means to cause locking portions engaged with said bi-directional locking means to move in and out of engagement with track portions (and in one embodiment the previously described block and nut portions) disposed proximate at least two opposed locations of said closure assembly, and when the window is a casement window further locking action resulting from the engagement of a third portion in and out of locking engagement with a locking detent provided adjacent the jamb wherein the window sash is contained. The operation of the operating means in a first direction causes the locking portion to move out of engagement with, the track portions or the detent provided with the track portion, and when a casement window is in use, the locking detent adjacent to the jamb, to therefore allow pivoting movement of the closure member. Movement of the operating means in the second direction causes the locking portions to move into engagement with the track portions or the detent provided with the track portion and therefore prevent the pivoting movement of the closure member. In a preferred embodiment, the release mechanism for locking a closure member includes a handle portion which has provided proximate one end thereof a handle and proximate the other end thereof a pinion, said pinion being engageable with a rack portion proximate one side thereof and a second rack portion proximate the other side thereof, said rack portions being engaged with locking portions which extend to the track or detent provided with the track in use to latch and unlatch the closure assembly, for example the window. When a casement window embodies the release mechanism, the pinion portion also engages one of the rack portions which further engages a second pinion rotatable by the motion of the second rack, the second pinion being engageable with a latch portion including a pinion sector provided therewith, causing the rotation of the latch portion into and out of engagement with a detent portion provided proximate the jamb of a casement window assembly, said single handle therefore operating both the locks proximate the track portion and when a casement window is used the lock proximate the jamb portion. Applicant refers the reader to U.S. patent application Ser. 08/171,750 filed Dec. 22, 1993, by the proprietor of the Assignee for this Patent Application, specifically referring to FIG. 33 and a description a bi-directional operating or release mechanism, the contents thereof which is hereby incorporated by reference, in relation to the structure and operation of the bi-directional release mechanism.
According to yet another aspect of the invention of the casement window assembly described above, there is provided a casement window assembly further comprising a jamb portion located proximate the pivoting end of the casement window preferably said window including a clip in flexible cover for the sash, said jamb portion including a pocket portion extending substantially towards the casement window sash and providing a pocket for the pivoting end of the casement window wherein said carrier is disposed in use, thereby providing a recess or pocket within which the closed casement window proximate the pivoting end thereof is located and when a cover is provided with the sash to snap fit those with to improve the seal and weatherproofing of the casement window, said pinion upon pivoting of the casement window causing the rotation of said gears and the sliding motion of the pivoting end of the window away from the jamb pocket thereof to prevent binding of the pivoting end with the pocket extending with the jamb portion, thereby providing the sealing improvements to the casement window, wherein when the casement window is moved to the closed position, the pivoting end will move back into the pocket provided.
According to yet another aspect of the invention, there is provided a conversion kit for a frame opening to convert a, a double-hung window or a tilt and slide window to a casement window assembly, said conversion kit comprising framing portions for containing track portions engageable with the framing portions of the window frame section (for example header and sill, or two vertical jamb members), said track portion, preferably being made from aluminum, and including a rack portion proximate at least one side thereof, a casement window sash having a carrier and interconnecting pivot assembly provided therewith substantially as described above, and for insertion and operation with respect to the track portions of the frame, wherein said casement window fully fills the space occupied by the previously installed double-hung or tilt and slide window, and the jamb, sill, and header portions are installed in the space provided. Typically, casement windows known today are narrow and of standard sizes. The known prior art hardware therefore provided prohibits the installation of a casement window where double hung or tilt and slide windows were previously installed. The present invention however opens up the possibility of changing window types as the consumer desires. Therefore, the existing window assembly is stripped out down to the wooden frame section. The installer installs the vinyl header sill and jamb section to the wooden frame chambers. The tracks are then installed, and preferably using the block and nut portions previously described, the block portion being screwed into the vinyl sill and header and the wooden frame members. The hardware with the carriers and interconnected pivots are then installed with the sash and squared in position. The window sash includes in the preferred embodiment the central locking handle and racks and pinions contained in the sash adjacent the opening end and contains the interconnecting shaft for the pivots. The casement window therefore replaces the previous window installation. Preferably a screen is provided with the vertical jamb on the inside of the casement window which can be extended and retracted in position to cover a window opening when the casement is open and to retract when the window is closed.
According to yet another aspect of the invention, there is provided a method of assembling a window sash, said window sash being used with a casement, tilt and slide or double-hung window and being interchangeable and of standard construction with respect to the various window sashes required, said method comprising:
(1) forming the sash element according to the standard profile, said standard profile comprising a generally rectangular "I" shaped member having a center reinforcement comprising an inner and an outer wall and a hollow therebetween and having extending from the ends of these inner and outer walls proximate both the top and bottom thereof substantially "I" shaped members extending substantially horizontally in profile extending along the length of the sash element also having inner and outer walls and a hollow therebetween, the sash element having provided proximate one end thereof flanges extending inwardly toward one another for receiving a dust cover or auxiliary member fastening thereto and having located proximate the other end thereof a glass engaging recess, the cover or auxiliary member being fastened to the sash profile and being variable from window style to window style,
(2) inserting the glass within the glass receiving portion of the sash elements and,
(3) connecting said sash elements with interior corner connectors having a quick fastening feature which are inserted within the central opening of the sash profiles provided and provide a one-way friction fit for connecting the comers proximate the interior of the sash element,
wherein said sash may be used for a tilt and slide window, double-hung window, or casement windows.
A method therefore of assembling the window is provided wherein, the sash components are assembled around a typical sealed double pane window glass by the quick fastening feature of the corner locking portions which are inserted within the opening of the sash profiles provided and provide one-way friction fit. The closed cell caulking is therefore inserted within the top and bottom of the sash assembled and these portions are covered by track covers by the compression of the closed cell foam and the engagement of the tabs of the track cover with the tabs of the sash profile. The hardware is then installed along the vertical portions of the sash within the openings thereof opposite the glass which is then covered by a sash cover portion provided. The hardware located proximate the pivoting end is therefore installed on the carrier portions and inserted within the track portion within the sill and header, for example of a window assembly. The window is therefore closed in position with the sash covers or track covers located proximate the sill and header snapping into the frame and closing any path for air to enter the window and pass the primary seals provided. The track covers also provide blockage of light, air and the friction fit of the sash into the track portions. By providing a track cover along the track remote the pivoting end of the window, this track cover may be used as support as well for the window assembly.
According to another aspect of the invention of the casement window described above, the casement window may further comprise a straight line window frame and assembly having a center mullion wherein casement windows are disposed on each side of the mullion with the operating portions including the carrier and interconnected pivot assembly and shafts thereof described above, thereby providing a double-casement window, wherein said casement windows pivot in substantially opposite directions, and provide a straightline window when in the closed position. According to yet another aspect of the invention, there is provided a cover for a tilt and slide window track, the track comprising a first half and a second half interconnected to provide a continuous track for the window, the first half being disposed below the closed window, and the second half being provided as a continuation of the first half, the second half including the track cover portion which clips into position to engage the flange portions of the sill of the window and thereby provide support for the window as it glides along the second half of the track.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic perspective view of a tilt and slide window, wherein said windows move in a horizontal direction, illustrated in a preferred embodiment of the invention.
FIGS. 1A and 1B are partial schematic perspective views of casement style windows embodying the invention and depicting the motion thereof and illustrated in a preferred embodiment of the invention.
FIGS. 1C is a partial schematic perspective view of straight line windows embodying the invention and depicting the motion thereof and illustrated in a preferred embodiment of the invention.
FIGS. 1D is a partial cutaway view of the casement style windows of FIG. 1A depicting a rollaway screen thereof and illustrated in a preferred embodiment of the invention.
FIG. 2 is a front view of the window of FIG. 1.
FIG. 2a is a top view of the window of FIG. 1.
FIG. 2b is a end view of the window of FIG. 1.
FIG. 2C is a perspective view of an alternative embodiment of the invention.
FIG. 3 is a double hung window assembly utilizing hardware similar to that of FIG. 1 and illustrated in a preferred embodiment of the invention.
FIG. 4 is the perspective illustration of the hardware only for a double hung window of FIG. 3.
FIG. 5 is an exploded perspective view of the components of the hardware of FIG. 4 to be installed in a double hung window assembly.
FIG. 6 is a carrier design illustrated in a preferred embodiment of the invention which allows for ease of removal of a window from a window assembly and illustrated in an exploded perspective view.
FIG. 7 is an assembled view of the components of FIG. 6.
FIG. 8 is a schematic view of a tilt and slide window assembly illustrated to emphasize primarily the hardware therefore and illustrated in an alternative embodiment of the invention.
FIG. 9 is a schematic view of the movement of the shoes of FIG. 8 illustrated in alternative embodiment of the invention.
FIG. 10 is a perspective illustration of a pulley arrangement installed at the corners of the window assembly of FIG. 8 and illustrated in alternative embodiment of the invention.
FIG. 11 is a close-up perspective view of a locking mechanism for the shaft assembly 30 shown for example in FIG. 1 and illustrated in a preferred embodiment of the invention.
FIG. 12 is an end view of the locking mechanism of FIG. 11 illustrated in a preferred embodiment of the invention.
FIG. 13 is an end view of a locking block assembly illustrated in a preferred embodiment of the invention.
FIG. 13A is an end view of the track profile used in conjunction with the lock block assembly of FIG. 13 and illustrated in a preferred embodiment of the invention.
FIG. 13B is a top schematic view of the lock block assembly of FIG. 13 shown engaging the rack portion of the track and illustrated in a preferred embodiment of the invention.
FIG. 13C is a side cross-sectional view of the adjusting cap screw used to adjust the track within the sill or header or jamb portions and illustrated in a preferred embodiment of the invention.
FIG. 14 is a top view of the carrier for the shaft assembly of FIG. 17 and illustrated in a preferred embodiment of the invention.
FIG. 14A is a cross-sectional view through the diameter of the opening 35b of FIG. 14 illustrated in a preferred embodiment of the invention.
FIG. 15 is an end view of the sash portions for a tilt and slide window assembly from the opening end of the window and illustrated in a preferred embodiment of the invention.
FIG. 15A is a close up view of the section of the assembly of FIG. 15 where the sash abuts with the sill and illustrated in a preferred embodiment of the invention.
FIG. 16 is a schematic end view of a central locking system best seen in FIG. 17 and illustrated in a preferred embodiment of the invention.
FIG. 16A is an end view of the central locking system of FIG. 16.
FIG. 16B specifically illustrates the latching plate and latch of the central locking system and illustrated in a preferred embodiment of the invention.
FIG. 17 is an exploded perspective view of a window sash for a tilt and slide or casement window illustrated in a preferred embodiment of the invention.
FIG. 18 is an exploded perspective view of the header, sill and jamb portions of the window assembly illustrating the track and its positioning in relation to the sill and header and illustrated in a preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1 and 2 through 2b there is illustrated a tilt and slide window assembly. The assembly 5 includes an outer frame portion 10 which is normally hung within an opening established in a building (not shown). Normally nailing flanges are provided for this purpose in order to attach the assembly to the outer frame 10. The frame 10 includes top portions 17 and bottom portions 16 having tracks disposed therein, as best seen in relation to FIG. 2. Within the tracks are contained a pivot assembly which will be hereinafter described. Primarily the pivot assembly includes a pinion 35 and carriers 38 and 37 interconnected by interconnecting portions 32 and 31 making up an interconnecting member 30. The pinions move as the window 20 is slid in the track portion by the movement of the pinion 35 with respect to the rack 18 or 19 respectively. In this way the pinions 35, being interconnected, remain parallel at all times in their motion along the track within which the rack 19 or 18 is disposed. The hardware is shown in normal view while the window assembly is shown in dotted lines, to emphasize the essence of the invention embodied with the assembly.
Referring now to FIG. 2 there is illustrated the window of FIG. 1, wherein windows 20 and 40 are slidable within a track 15 and 17 upon a shoe 39. The lower shoe 39 also is connected to a secondary shoe 39a for carrying the window which includes rollers 39b and 39a1 on the bottoms thereof respectively for ease of movement within track 17. The pinion 35 rests within the shoe 39 as will be described hereinafter. The arrangement of the interconnecting portion 30 will also be described hereinafter. Window 40 therefore has its own interconnected system as can be best seen in relation to FIGS. 2a and 2b.
Referring now to FIG. 2a there is illustrated the sash elements 20 and 40 and the rack portions 19 and 19a which accommodate the motion of the pinion 35 along the full length of the track, as best in FIG. 2b.
Referring to FIGS. 1 and 2 to 2b clearly the track portions 17 and 15 cooperate with the rack portions 19 and 19a to provide for engagement with the pinion 35 and its motion when the window remains slidable within the track. By interconnecting the two pinion portions and hence the two pivot shoes, by interconnecting means 30, the shoes remain in a substantially parallel position in relation to one another at all times. This overcomes the problem described in the background of the prior art. By the shoes remaining substantially parallel at all times it is almost impossible for the window to come out of the track when the window is pivoted to be cleaned, and therefore it is no longer necessary to provide braking portions as in previously described inventions of Canadian Thermo Windows, as referred to in the background of the invention.
Referring to FIGS. 1A and 1B there is illustrated a casement style window having similar components to that found in relation to FIG. 1 with the exception that only one sash is provided which is fastened on shaft assembly 30 including portions 31 and 32. A link L is provided secured proximate ends L1 adjacent the center of the sash 21 proximate the bottom thereof and adjacent the track 18 adjacent the opening end of the window sash 21. By positioning the sash in this manner a full range of pivoting motion is available. If the link end L1 is removable from the sash, then the window sash may be moved totally to the opposite end remote the pivoting end 21b on shoe 39. As with the case of the tilt and slide window a shoe 39 containing a pinion is provided. The pinion is connected to the shaft 30 and engages the rack 18 as it moves along the window sill and header in parallel arrangement between the upper and lower pivots maintained in parallel by the shaft 30. In this manner the casement style window may be pivoted as normal to an open position, and the pivoting end may be moved to the other end of the window frame away from side 21b to allow ease of cleaning. By supplying the hardware described without a casement sash, the casement window may be assembled without the need for expensive pivots and linkages and without a great deal of assembly labour. As best seen in FIG. 1D for the casement style window in particular a rollaway screen S may be provided which is housed in the jamb channel as illustrated. The screen S pulls across to engage detent D1 with detent D2 in the opposite channel jamb, whereat it may be locked. This allows a user to clean the glass of sash 21 on the inside without the need to remove the screen as in prior art casement structures.
Referring to FIG. 1C there is illustrated a tilt and slide type window similar to FIG. 1 with the exception that when closed the window sashes will be oriented in a straight parallel line with one another. In order for this to happen the rack 18 provided includes a portion 18a made from fiber filled plastic or the like and joined at seam 18c to an aluminum track 18b. The sash 21 is therefore moveable as previously described on carrier 39 and rollers 39a as urged by pinion 35 until the pinion reaches the curved portion of the track 18a a wherein the assembly 30 will move along the curved portions of the track to the terminus of the track 18t. The sash portion 21a will then but in behind the edge of the sash contained in track 18' and be lockable at that position. The sash 21' (not shown) resides on assembly 30' in track 18'. As pinion 35' moves within the limits of rack 18' the sash 21 cannot adopt a parallel position unless sash 21' is in its fully closed position. Only then can the end 21a of the adjacent sash adopt its fully closed position butting up against the sash 21' at the end opposite the carrier assembly 30' and 39'.
Referring to FIG. 3 there is illustrated a double hung window assembly embodying a preferred embodiment of the hardware making up the invention substantially equal to that which is disclosed in FIG. 1, with the exception that a coil spring 31a is provided around the connector portion 31 of the interconnecting portion 30. By providing the interconnecting portion 31 with a spring 31a it will no longer be necessary in a double hung window assembly to provide a sash balance, as the spring 31a is pre-loaded to provide the necessary tension, much the same as a spring which is used in a garage door. In this example as a garage door goes up and down the spring is compressed and tensioned depending on the motion of the door and therefore provides for the return motion of the door. Within the window assembly sashes 20 and 40 shown in ghost line are moveable in a manner similar to the garage door example with hardware substantially made up of a pivot or pinion 35 moving on a rack 18 and 19 respectively and being interconnected by the interconnecting portion 30. The spring mechanism 31a provides an assist to the user, as in the case of the example, when the window sash is opened.
Referring to FIGS. 4 and 5 there is illustrated the hardware which is installed within the double hung window assembly of FIG. 3. Pinions 35 therefore are provided, which seat within the carriers or shoes 39. The pinion includes a shaped opening 35a which is compatible in shape with the bar stock 34c and 32a proximate the ends thereof. The pinion therefore will ride on the rack 18 and 19 within shoe 39. Opposed supplementary portion 37 is provided to oppose the shoe 39 in the jamb as it rides in the track. Therefore, referring to FIG. 2b the portion 37 and 38 may be readily seen. A combined ratchet and pawl assembly is provided with portion 37 or at least connected therewith. The pawl assembly 37c is resilient biased through the opening 37d of member 37 so as to release the ratchet 34b of shaft 34 when the window is to be removed from the assembly. Proximate the other end of the hardware there is provided a backing member 38 in a unique shaft extension 33 which includes portions 33b, 33d, 33c and 33a wherein the shaft end 32a extends through. A locking nut 33e is provided to lock the entire hardware together and to allow for ease of separation thereof. An adjustable connector 31b is provided proximate the other end of member 32b which allows for adjustment with regard to the length of section 32 of the shaft so as to allow variation in the sizes of the assembly supported. Portions 31, 31b, 32, and 33 makeup the shaft assembly which allows for ease of installation, adjustment, alignment and removal of the sash assembly. Also the hardware described provides for the interconnection of the pivot shoes proximate their sides and provides for parallel motion of the pivot shoes at all times thereby eliminating the need to lock the pivot shoes in the track assembly.
Referring to FIGS. 6 and 7 there is illustrate an alternative shoe construction which is useful when a window is removed, since the shoe will be locked in position when the window is removed for maintenance or for cleaning. Therefore the shoe 39 includes a spring b and a recess therefor and a supplementary portion 39d and a finger of a therefore therefor c are provided on supplementary portion 39d which are biased by spring b against the pinion 35 to thereby lock against pinion 35 and prevent the motion of the carrier when the window is removed. A sloped wall d is provided with the carrier supplementary portion 39d, which when the shaft is removed or reinstalled thereby releases the supplementary portion away from the pinion or toward the pinion. Therefore when the supplementary portion d is engaged it will drive the supplementary portion 39d away from the pinion 35 thereby allowing free motion of the pinion in normal circumstances. However when the shaft is disengaged the portion 39d will be free to move as biased by the spring b toward locking the pinion 35 via the teeth c of the supplementary portion 39d. The alternate shoe of FIG. 6 and 7 has an opening 35a within which the shaft extension 32a or 34c passes to interconnect with the shoe 39 as previously described. The rollers 39b engage with the notches as shown to improve the motion of the carrier in the track.
Referring now to FIG. 8, 9 and 10 there is illustrated an alternative embodiment of the invention to maintain the carrier pivots 61, 65, 60 and 81 in substantially parallel alignment and thereby eliminate the need for braking mechanisms. FIG. 8 is illustrated as a tilt and slide frame in ghost line with the window 70 also shown in ghost line having pivot 75 and 71. The pivots 75 and 71 engage with openings within the shoe 61 and 65 in the manner which is known. These pivot pins 75 and 71 may be removed from these shoes merely by retracting them from their locked positions. The sash 70 therefore is moved on the carrier 81, 82 and 83 proximate the bottom thereof in the track portions as shown and within carrier 60 on the top thereof. A similar sash arrangement would be arranged for the other shoes as well but for simplicity sake this is not illustrated. The important aspect is that a cable 91 is connected to the carrier 60 and the carrier assembly 81, 82 and 83 substantially as shown in FIG. 9, so that when the window moves toward the right hand side of the drawing, both carriers will move an equal amount by the movement of the cable, maintaining the pivots 75 and 71 within the shoes 60 and 81 substantially parallel at all times. Similarly, a cable 90 is provided which moves in conjunction with the carrier 63, 62 and 61 and the shoe 65, as best seen in FIG. 9, so that as the shoe 65 is moved in a direction D20 that the carrier 61, 62 and 63 will also be moved in the direction D20. FIG. 9 therefore shows the path of the cable connecting the carrier described above.
In order to allow for the movement of the cable the unique pulley arrangement is illustrated in FIG. 10 wherein the cable will travel through the respective channels 107, 108 and 105a within through 105, or through 106, 104, 105a within the opposite wheel or pulley 105. Assembly 101 is therefore provided which is affixed within the window frame via opening 101a and a fastener, not shown, which assembly allows for the movement of the cable and hence the carriers in a manner as best seen in FIG. 9.
Referring now to FIGS. 11 and 12 there is provided a locking mechanism for the shaft 30 which may be used with any closure assembly. A handle assembly H is provided including a stationary portion H2 fixed to the sash 21 and a moveable spring biased portion H1 biased to a continual locked position via spring leaf S2. The handle portion H1 includes a pivot H4 and detent portions H5 and H6. Normally the spring S2 will cause the handle portion H1 to remain in engagement at detents H5 and H6 with gear portion or serrations 30Z of the shaft 30. Therefore the window or door is locked in that position and cannot be pivoted or slid. When a user engages the handle H1 and presses it towards H2 the detents H5 and H6 release from the gears 30Z and hence the window or door may be repositioned as desired. At that repositioned location when the user releases the handles the window or door will again become locked.
Referring now to FIGS. 13, 13a, 13b, 13c and FIG. 18, there is illustrated a track portion 18 and 19 which is to be installed within, as shown in FIG. 18, the sill and header 220 of a frame assembly also including upwardly extending jamb portions 220a. The track portions 18 and 19 therefore are installed within the profiles as seen in FIGS. 2b and 18 by the provision of a locking block assembly 200 which includes an adjuster nut 210 which engages the rack portion 18x of the rack 18a of the track profile 18. The profile therefore includes the rack 18a, a riding portion for the rollers 18e which will be explained hereinafter, and a recess 18d wherein a carrier as best seen in relation to FIG. 14 rides with the exception of the rollers. The track 18 therefore must be locked in position in the sash 220, and this is affected by the locking block 200 and the moveable nut 210. As best seen in FIG. 13c, the track is inserted into the sill profile as shown so that the carrier may ride on the track. The assembly of FIG. 17 for the sash is therefore engaged with the carrier. The block 200 therefore is screwed down through the profile 15 into the wooden frame member not shown via opening 15c in the profile and 204 in the block 200. Two fasteners 205 therefore are provided, and as shown in FIG. 13, they are inclined at an angle to the vertical in order to allow for the provision of an adjuster 206 which is accessible through the opening 207 in the block 200 wherein a cap screw having a head 206a having an allen key type access slot is provided. The threading 207a extends down to the end 207a proximate the nut 210.
As best seen in FIG. 13, the lock block 200 and the locking nut 210 have a profile substantially as shown with a triangular shaped cut out provided adjacent the top thereof and wherein abutting portions 201 and 203 are provided to engage with the flanges 15b and 15a of the profile of the sill portion 220. The triangular cut-out portion includes an upwardly vertical face 202a, and bottom 202. Similarly the nut has a shoulder 211 provided and a substantially triangular shaped cut out 212 and an upwardly extending face 212a for engaging with the sill profile 15 similar to that which is illustrated and described in relation to FIG. 13. The rotation therefore of the cap screw 206 results in the movement of the nut 210 in relation to the block 200 which is fastened in position. The adjustment therefore of the screw allows for the thread to engage a threaded opening not shown in the nut 210 so that the rack portions 213a provide engagement with the rack 18a of the track portion 18 and will allow for fine adjustment in the positioning of the track 18 and the locking in position of the track. It has been found sufficient that by providing the block and the adjustment of the nut, it will sufficiently position and lock the track in position and allow for the adjustment of the track which will then further allow for the adjustment of the pivots as best seen in FIGS. 1, 1a, 1b, 1c, FIG. 2, FIG. 3 and FIG. 17 so that the parallelism is not lost, and if fine adjustments once installed are required to the window sash to maintain the parallelism of the system, this is very easy to do. Should the system go out of parallel and require fine adjustment to restore the parallelism, a mere rotation of the head 207 is required for both the sill and headers 220 so that the system is squared.
The notch portion defined by the faces 202a and 202 have a unique purpose in that the latch portion 251 as well as 250, as best seen in FIG. 17, will engage with the face 202a and provide a lock detent for the lock 251. This adds reinforcement to the lock provided in that should the triangular shaped detent of the block not be provided, then the lock 251 would engage flange 15a and in time would wear out that flange in that particular locking position. The nut 210 has a similar function so that either the nut or the block can function as the detent for the latch. Specifically in FIG. 18, the screw 206 is shown being engageable from the nut toward the block, and in fact it is accessible in either direction as shown in FIG. 13 and FIG. 18 without changing the advantages of the system. For access purposes, depending on the installation and the type of window, it may be easier to adjust as shown in FIG. 18 as opposed to FIG. 13. Preferably the block is made from fiber-filled nylon. Alternatively, the block may be made from aluminum. The nut may be made from fiber-filled nylon as well.
Referring to FIGS. 14, 14a and 18, there is illustrated a carrier 39x which includes a pivot portion 35 for engaging with the shaft portion 32 and 34c of the pivot assembly and for carrying that shaft assembly and the pivoting end of the sash in the track 18 and 19 respectively of FIG. 18. The carrier includes a portion 39y provided therewith to carry the rollers 39b therein. This is very similar to the carrier illustrated and described in the previous descriptions and more specifically in relation to FIG. 1a and 1b, with the exception that the details of the carrier were not shown at that time in relation to the thrust wheel 35c provided on the bottom.
The carrier, as best seen in FIG. 1 a therefore rides on the rollers on the track profile seen in FIG. 13A on the surfaces 18e for the roller wheels 39b and in the notch or cut-out recess 18d for the side portions adjacent the roller 39b at 39z. The pinion portion 35 therefore has an opening 35b for receiving the shaft 32 which extends toward the bottom of the opening 35d and which opening 35b as best seen in FIG. 14 is compatible with the shape of the shaft 32. The outer surface 35a of the opening 35b is compatibly shaped with the opening in the carrier so that the opening 35b may be accessible to the shaft 32. At the bottom of the pinion portion 35 is a thrust wheel carrying portion 35e which carries the thrust wheel 35c. The thrust wheel 35c therefore rides in between the shoulders 18c and 18b on the surface 18d of the track profile 18. The thrust wheel is provided to accommodate any wind load which may be placed on the system when the window is opened. Further, in the normal meshing of gears with a rack, there is a thrusting force created as the pinion 35 moves on the rack 18x. Therefore, the thrusting wheel will engage from time to time the shoulders or the surfaces defined by the shoulders 18c and 18b so as to maintain the parallelism and the accuracy of the installation of the window system. A pinion gear 35a is therefore provided between the thrust wheel 35c and the pivot receiving opening 35b which operates substantially as described in relation to FIG. 1A and FIG. 1 in that as the window rotates the pivot rotates causing the gear 35a to rotate and move on the track. This is particularly advantageous when the pivot assembly is provided on a casement window as best seen in relation to FIG. 1A in that it is desirable to have the window move away from a pocket provided in the window jamb as best seen in relation to FIG. 1D so that the sash profile will not engage the jamb profile but will readily clear the jamb profile as the window is opened. For example, as best seen in FIG. 1D, proximate the top thereof, it may be readily seen that a pocket is provided in the jamb profile so that the pivot assembly 30 is accommodated at that end of the window. However, a flange portion unlabelled engages the sash cover portion so that within the jamb J1 there is a pocket J2 provided which improves the seal of the window in that the cover portion SC extends into the pocket J2 when the sash is closed. However, when the sash is pivoted as in the case with the casement window of FIG. 1C, the pinion gear when pivoted will move the sash and the sash cover SC out of the pocket J2 away from the jamb J1 and provide suitable clearance so that the sash cover SC will not engage with the jamb portion J3 which is a flange and therefore will clear easily the pocket and all its enabling portions. When the casement window is closed, the opposite happens and the sash cover SC will engage the pocket J2 and be moved in position with the pivoting of the window to the closed position.
The rollers 39b therefore provide a smooth motion of the closure system in relation to the track which would not be present if the rollers were not provided since the track is made from aluminum. The rollers are not absolutely essential in every embodiment, however, it is preferred.
Referring now to FIG. 15, there is illustrated two sashes side by side shown in end view. The sashes are made substantially as constructed in relation to FIG. 17 wherein the sash 220 is defined by a central I-shaped portion 227 having an opening therein and two side abutting portions 225 and 226. A pocket therefore for receiving the glass G is defined at 222. Fin seal portions 221 are therefore provided for abutting the glass G which contains the normal known seal portion SX. The window sash profiles also include flange portions 224 proximate the opening opposite the glass G. Within that opening there is provided in use a closed cell caulking foam which is compressible at portion 240. This portion extends totally along the sash profile within the opening as shown with the exception of the portion adjacent the pivoting assembly. A cover portion therefore is provided at 230 which engages the tab portions 224 proximate each side of the sash profile. This cover portion when inserted is flexed downwardly as the closed cell foam 240 is compressed as best seen in FIG. 15a so that the flange portions of the cover at 230a engage with the flange portion of the sash at 224 to provide a compressed seal for the track cover 230. The track cover is defined as a track cover although it does occupy the sash as a component thereof in that as the sash is closed over the opening defined between the flange portion 16a and 16b as best seen in FIG. 15a, the snap cover portion will extend down into and engage with the flanges 16a and 16b, thus covering the track and snapping into position each time the sash is opened and closed. The typical seals BX and BY are provided as is known in the art.
Alternatively, as best seen in FIG. 1D, the sash covers may include alternative embodiments shown proximate the jamb portions 16a and 17a of the window assembly. Alternatively, a cover portion may be provided over the track portion 15 of sill portion 220 and header portion 220 of FIG. 18 that engages with the sash profile in a similar way to that of the track cover of FIG. 15a with the exception that the track cover only extends over the second half of the track, that is to say the second half not carrying the window. For example as shown in FIG. 2, the wheel portion 39a may be eliminated and the track cover may extend along the track portion opposite the pivot assembly so that the sash may slide on the track cover and be assisted to be supported by that track cover only in the second half of the track profile thereby eliminating the second carrier of FIG. 2. The track cover therefore in FIG. 2 as an example would extend from the carrier 39a toward the left side of the page to allow the pivot assembly 35 to move to approximately the position of the present carrier 39a wherein it would engage the track cover. In the movement of the carrier 35 to that position, the other end of the window would already be supported by the track cover. This installation therefore would eliminate the carrier 39a.
Referring now to FIG. 16B, there is provided locking detents 250 and 251 which engage with the locking detent portions 202 and 212 of the lock and nut portions 200 and 210. These locking portions 250 therefore and 251 are operated by a handle 260 as best seen in FIG. 16A which is rotatable to cause the motion of the rack portion 265 and the detent 250 into and out of the locking abutment provided with the lock block and the lock nut 200 and 210 respectively. In FIGS. 16, 16A and 16B, the installation is provided for a casement window assembly. In the United States Patent Application described in the Summary of the Invention which was incorporated by reference, there is no provision of a casement-style window lock. Nor was there the provision of a lock block or nut detents 210 and 200 respectively. The handle therefore 260 is rotated by the user which causes the movement of the corresponding pinion gear 261, the rotation of the pinion gear 261 affects the movement of the rack 265, and the latch engaging portion 250a and 251 a carried within the housings 255 and 254 respectively as best seen in relation to FIG. 17. The rotation of the pinion will therefore also cause the motion of the rack portion 266 sufficiently as provided by the opening 266a of said rack portion to allow for engagement of said rack portion with said rack portion 265 with the bottom portion affecting the latching and unlatching of detent 251. Intermediate the two latching portions for the casement window is provided a second pinion 267 which is rotated effectively by the movement of the rack portion 266. Rotation of the pinion 267 causes rotation of the pinion sector 268 which is engaged with the locking detent 269 for the latch plate 270 and the detent 271 thereof. This latch plate is typical for casement windows as is the movement of the lock 269, i.e. the rotation thereof. However, with the central locking system provided with this invention, it is the one handle operation of both the detents 250 and 251 and the casement window lock 269 which is in combination the essence of the central locking system. Alternatively, the casement window portion may be left out and the essence of the locking system therefore includes the locking block in the track which provides a detent for the locks 250 and 251 respectively.
As best seen in relation to FIG. 17, there is provided a cover C(x) which hooks into the sash profile similarly to the cover 230 previously described in relation to FIGS. 15 and 15A through which the handle portion 260 extends. Therefore, the latch assembly is contained within the sash profile, and the only portion extending outside of the sash profile is the handle portion. This handle portion is considerably smaller than the normal handle portion provided with a casement window which is typically rotary, and there is a tremendous elimination of components for a casement-type window. In fact, this will be described hereinafter.
Referring to FIG. 17, there is shown an exploded perspective view of the window assembly which will fit into the track profile similar to FIG. 18, but more specifically which may be designed for a casement window. The sashes 220 are provided with an opening 227 wherein a corner connector 280 is provided which extends into the opening 227 proximate all four corners and eliminates the necessity for welding. Clip portions 281 bite into the vinyl and are tapered in a direction so as to prevent the removal of the corner connectors once inserted within opening 227. This snap lock feature therefore provides for the installation of the comer connectors and the quick fastening of the sash profile around the glass G. The track covers 230 are therefore provided and snapped into position once the closed cell foam, best seen in FIG. 15a at 240, is inserted within the opening of the sash profile. The hardware including the carriers, best seen in FIG. 18, which are then assembled within the opening opposite the glass of the sash proximate each jamb portion in use. The hardware therefore including the top and bottom track abutting connector portion 39x and 37x, the shaft 32, the connector 31bx, the other shaft 31, and the small shaft 34c are provided proximate the pivoting end of the window assembly within the sash profile enclosed by a cover similar to that of cover CX. The central lock as described in relation to FIGS. 16, 16A and 16B is therefore inserted within the other opening of the sash profile and assembled and covered by the cover CX. The window sash is now available for installation within the frame assembly of FIG. 18 once the connectors portions 39x are connected to the corners of the sashes and subsequently via the respective shafts 32 and 34c to the carriers. The block portions 200 are therefore locked in position once the track is installed in the frame, and the nut portions are adjusted to allow for the parallelism of the carriers within the tracks to ensure the parallelism of the sash so that it rides well within the track portions. The window is therefore assembled.
For a casement window, all of the prior art levers and latch mechanisms are substantially eliminated. This means a great deal to window manufacture in that there are a considerable number of screws and fasteners to hold down the prior art lever linkages of the prior art systems. In the present invention, only the latch block fasteners are provided. The rest of the window assembly merely snaps together with a friction fit of the sash profiles, the sash profile covers and the frames. A minimum of assembly labour is therefore required with the installation of this window assembly. In one particular situation where an old style double-hung window is installed within an opening, it may be conveniently removed by an installer and the present invention may be installed in any of its embodiments including a casement window.
This is heretofore unknown in that a casement window occupies a certain standard space in the industry, and because of the linkage systems and the known systems, it is not possible to provide a larger window. With the present invention, a larger casement window may be provided which is easily installed with the minimum amount of labour and assembly time required. Should the window now be mis-aligned for any reason, it may be easily adjusted by the rotation of the screw 206 provided. A sophisticated user therefore could easily adjust this once instructed over the phone by an installer, or alternatively the installer may return for a quick adjustment at any time. Also, the window assembly is less likely to go out of adjustment because of the great care taken in the development of the precision of the assembly.
A method therefore of assembling the window may be considered as described in the above-mentioned description wherein, firstly the sash components are assembled by the quick fastening feature of the corner locking portions which are inserted within the opening of the sash profiles provided and provide one-way friction fit. The closed cell caulking is therefore inserted within the top and bottom of the sash assembled and these portions are covered by the track covers by the compression of the closed cell foam and the engagement of the tabs of the track cover with the tabs of the sash profile. The hardware is then installed along the vertical portions of the sash within the openings thereof opposite the glass which is then covered by a sash cover portion provided. The hardware located proximate the pivoting end is therefore installed on the carrier portions and inserted within the track portion within the sill and header, for example of a window assembly. The window is therefore closed in position with the sash covers or track covers located proximate the sill and header snapping into the frame and closing any path for air to enter the window and pass the primary seals provided as best seen in relation to the FIG. 15A. The track covers also provide blockage of light, air and the friction fit of the sash into the track portions. By providing a track cover along the track remote the pivoting end of the window, this track cover may be used as support as well for the window assembly.
In another embodiment not shown, a double casement window is provided which is provided in a straight-line window, that is to say a frame is provided wherein a central mullion is disposed. A central mullion separates two casement windows, one opening as a mirror image of the other and containing all of the elements described above in relation to the pivot assembly and the central locking system and track system.
As many changes can be made to the preferred embodiments of the invention without departing from the scope or intent thereof; it is intended that all matter contained herein be considered as illustrative of the invention and not in a limiting sense.
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A closure assembly is provided including a track and a slidable and pivotable closure member. The closure member is engaged with the track proximate first and second pivots adjacent the pivotable end of the member, the first and second pivots being interconnected by a multiple segment shaft (for example at least two portions) (for example telescoping) which provides for accurate installation, retention, removal, adjustment and alignment of the first and second pivots in a substantially parallel line for pivotally supporting the closure member so that it may be safely and securely pivoted away from the closure assembly. Improvements to the abovementioned structure are also provided.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority from Japanese patent application No. 2004-124683 filed on Apr. 20, 2004, the content of which is hereby incorporated by reference into this application.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a semiconductor integrated circuit device, and more particularly to a technique that can be effectively applied to, for instance, a system-large scale integrated circuit (LSI) in which each of a plurality of functional modules is divided into circuit blocks and power supplied is turned on or off according to the operation or non-operation of each functional module.
[0003] There is Japanese Unexamined Patent Publication No. 2002-026711, which discloses a configuration in which the circuit is divided into a circuit block consisting of a MOSFET having a low threshold voltage and a circuit block consisting of a MOSFET having a high threshold voltage, the leak current is reduced by cutting off power supply to the circuit blocks of the low threshold voltage in the standby mode when the semiconductor integrated circuit device is not operating, and a gate circuit known as a wrapper is provided on the route on which its input signals and output signals are communicated. Also, the existence of Japanese Unexamined Patent Publication No. 2003-218682 is reported, which discloses a configuration comprising a sending-side circuit block having a power switch, a receiving-side circuit block, and a micro I/O circuit for supplying output signals from the sending-side circuit block to the receiving-side circuit block as input signals, in which the micro I/O circuit prevents the output signals from being propagated with a control signal from the receiving-side circuit block when power supply to the sending-side circuit block is cutoff by the power switch. However neither of these patent references makes any mention of technical problems the invention under this application intends to solve.
[0004] [Patent Reference 1] Japanese Unexamined Patent Publication No. 2002-026711
[0005] [Patent Reference 2] Japanese Unexamined Patent Publication No. 2003-218682
SUMMARY OF THE INVENTION
[0006] According to Patent Reference 1, the whole LSI is divided into a low-threshold voltage circuit block and a high-threshold voltage circuit block and a leak current is reduced by cutting off power supply to the low-threshold voltage circuit block when the LSI is in the standby mode. Therefore, where a plurality of functions are mounted on a single semiconductor integrated circuit device as in a system LSI and there are both operating functional blocks and non-operating functional blocks, the above-stated technique of power saving by cutting off power supply to non-operating functional blocks cannot be applied. On the other hand, Patent Reference 2 discloses a configuration in which the circuit is divided into functional blocks, and power supply to standing-by circuit blocks is cut off. However, this configuration requires a special circuit block to connect the two circuit blocks, i.e. the micro I/O circuit, to prevent the through current, which would arise in the circuit block to which power is supplied as a result of the floating of the output signals of the circuit block to which power supply has been cut off. This is also true of the configuration according to Patent Reference 1, wherein the low-threshold voltage circuit block to which power supply is cut off is provided with circuit blocks known as an output wrapper and an input wrapper.
[0007] These configurations in which are arranged, apart from circuit blocks to perform the essential functions of the circuit, circuit blocks which prevent unfixed signals in the circuit block to which power supply has been cut off is prevented from being transmitted to the circuit block to which power is supplied, such as the wrapper and the micro I/O circuit, involve a problem of increased man-hours spent on the designing of circuit block arrangement for that purpose. Especially the configuration according to Patent Reference 2 involves a problem of requiring different ways of control to match four cases of power cut-off, as stated in paragraph 0020 of the specification, because where the micro I/O circuit has a level changing function, the earlier stage is supplied with the same source voltage as the sending-side circuit block and the later stage is supplied with the same source voltage as the receiving-side circuit block, with the consequence that one circuit block is supplied with a common source voltage to a different circuit block.
[0008] An object of the present invention is to provide a semiconductor integrated circuit device which achieves multi-functionalization and power saving with a simple configuration. Another object of the invention is to provide semiconductor integrated circuit device enhanced in design efficiency while achieving multi-functionalization and power saving. The aforementioned and other objects and novel features of the invention will become apparent from the following description in this specification when taken in conjunction with the accompanying drawings.
[0009] To briefly describe a typical aspect of the invention disclosed in the present application, the semiconductor integrated circuit device has first through third circuit blocks, wherein the first circuit block has a first power supply state in which the operation of internal circuits is guaranteed in accordance with an instruction from the third circuit block and a second power supply state in which the operation of the internal circuits is not guaranteed, the second circuit block has an input unit which receives signals supplied from the first circuit block, and the input unit of the second circuit block has an input circuit which, in accordance with the control signal which was responded to when the second power supply state was instructed by the third circuit block to the first circuit block, causes a specific signal level to be maintained in compliance with the operating voltage of the second circuit block irrespective of the signal supplied from the first circuit block.
[0010] With a simple configuration, inputs at unfixed levels to a circuit block in an operating state can be prevented while saving power consumption by interrupting power supply to a standing-by circuit block. The control signal for the prevention of inputs at unfixed levels can be easily generated and matched with power cut-off control.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 show the configurations of the smallest unit of a semiconductor integrated circuit device, which is a preferred embodiment of the present invention.
[0012] FIG. 2 is a timing chart illustrating the operation of the circuit block 3 in FIG. 1 .
[0013] FIG. 3 is an overall block diagram of a semiconductor integrated circuit device, which is a preferred embodiment of the invention.
[0014] FIG. 4 is a circuit diagram of an example of input circuit provided in the micro input/output circuit of FIG. 3 .
[0015] FIG. 5 shows the configurations of the smallest units of another semiconductor integrated circuit device pertaining to the invention.
[0016] FIG. 6 is a waveform chart illustrating an example of operation of the circuit embodying the invention, shown in FIG. 5 ,
[0017] FIG. 7 are block diagrams illustrating an example of operating form of an input circuit for preventing the propagation of unfixed levels according to the invention.
[0018] FIG. 8 are block diagrams illustrating another example of operating form of an input circuit for preventing the propagation of unfixed levels according to the invention.
[0019] FIG. 9 is a timing chart illustrating an example of standby shifting sequence of a specific circuit block in a semiconductor integrated circuit device embodying the invention.
[0020] FIG. 10 is a timing chart illustrating an example of return from standby sequence of the specific circuit block in the semiconductor integrated circuit device pertaining to the invention.
[0021] FIG. 11 is a schematic block diagram of a whole system pertaining to the invention corresponding to FIG. 10 and FIG. 11 .
[0022] FIG. 12 is a schematic block diagram of a semiconductor integrated circuit device pertaining to the invention.
[0023] FIG. 13 is a schematic block diagram of another semiconductor integrated circuit device pertaining to the invention.
[0024] FIG. 14 is a schematic block diagram of still another semiconductor integrated circuit device pertaining to the invention.
[0025] FIG. 15 is a schematic layout of a semiconductor integrated circuit device pertaining to the invention.
[0026] FIG. 16 is a layout of one example of power supply lines matching the vdd-supplied logical unit 2 in FIG. 15 .
[0027] FIG. 17 is a schematic layout of one example of lower part of the power supply line matching the vdd-supplied logical unit 1 in FIG. 15 .
[0028] FIG. 18 is a circuit diagram illustrating the relationship among the power supply SW controller (PSWC), the power supply SW and the internal logic in FIG. 17 .
[0029] FIG. 19 is a schematic layout of one example of cell C in FIG. 16 .
[0030] FIG. 20 is a schematic layout of one example of power supply line of the semiconductor integrated circuit device pertaining to the invention.
[0031] FIG. 21 is a circuit diagram of one example of step-down power supply circuit to be mounted on the semiconductor integrated circuit device pertaining to the invention.
[0032] FIG. 22 is a circuit diagram of another example of step-down power supply circuit to be mounted on the semiconductor integrated circuit device pertaining to the invention.
[0033] FIG. 23 is an overall block diagram of another example of semiconductor integrated circuit device pertaining to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] FIG. 1 show the configurations of the smallest unit of a semiconductor integrated circuit device, which is a preferred embodiment of the present invention. FIG. 1 (A) shows one example of one type of operating state, and FIG. 1 (B), one example of another type of operating state. The smallest unit of the semiconductor integrated circuit device of this embodiment consists of three circuit blocks. A circuit block 1 , turned off in a standby state, is provided with a power switch. A circuit block 2 has a circuit portion which operates in response to a signal from the circuit block 1 . The presence or absence of the function of turning off when standing by is irrelevant to the circuit block 2 . The circuit block 1 is provided with a circuit block 3 which generates a control signal SWC for power supply control and a control signal INC for preventing propagation of unfixed levels from a circuit block to which power supply is turned off. Power supply to this circuit block 3 is on all the time. An input circuit for receiving signals from the circuit block 1 is provided in the circuit block 2 . The input circuit is composed, as its illustrative example, of logical gate circuits including a latch circuit FF, a NAND circuit G 1 and a NOR circuit G 2 .
[0035] Referring to FIG. 1 (A), both of the circuit blocks 1 and 2 are placed in an operating state. Thus, the power supply control signal SWC transmitted from the circuit block 3 causes power to be supplied to the circuit block 1 . The control signal INC for preventing propagation of unfixed levels transmitted from the circuit block 3 causes the input circuit provided in the circuit block 2 to capture signals transmitted from the circuit block 1 .
[0036] Referring to FIG. 1 (B), the circuit block 1 is placed in a non-operating state, and the circuit block 2 is placed in an operating state. Thus, the power supply control signal SWC transmitted from the circuit block 3 cuts off power supply to the circuit block 1 . The control signal INC for preventing propagation of unfixed levels transmitted from the circuit block 3 causes the input circuit provided in the circuit block 2 forbids communication of the unfixed level (Hiz: high output impedance state) transmitted from the circuit block 1 , and causes a fixed level matching the control signal INC to be transmitted to internal circuits. This prevents through currents due to unfixed levels from arising in the circuit block 2 in operation, and prevents the circuit block 2 from being caused to operate erroneously by any input of an unfixed level. In other words, the circuit block 2 is enabled to realize its signal processing, which is its essential function.
[0037] FIG. 2 is a timing chart illustrating the operation of the circuit block 3 in FIG. 1 . The circuit block 3 , though not illustrated in FIG. 1 , generates the control signal SWC for controlling power supply to the circuit block 1 in response to a clock signal CLK, such as a system clock, and a standby signal STB, and the control signal INC for preventing propagation of unfixed levels in the circuit block 2 . When the standby signal STB is generated, the circuit block 3 deciphers that signal, thereby determines the circuit block 1 to be in a standby state, and transmits the control signal INC for preventing propagation of unfixed levels to the circuit block 2 in synchronism with the clock pulse CLK. Thus, in response to the high level of the control signal INC, the input circuit of the circuit block 2 forbids signal communication from the circuit block 1 , and forms a fixed level conforming to the control signal INC. After that, the control signal SWC for power supply control varies from the high to low level in synchronism with the clock pulse CLK, the power switch in the circuit block 1 is turned off to cut off power supply to the circuit block 1 .
[0038] FIG. 3 is an overall block diagram of a semiconductor integrated circuit device, which is a preferred embodiment of the invention. In this drawing, the semiconductor integrated circuit device is shown to operate on two source voltages VCC and VDD, though this is not the only possible configuration. The source voltage VCC is relatively high, such as 3.3 V, and the source voltage VDD is relatively low, such as 1.2 V, though again these are not absolutely required. The relatively high source voltage VCC and a ground potential VSS matching it are supplied to an input/output (I/O) buffer and a VCC-supplied logical circuit disposed in the peripheries of the chip. The relatively low source voltage VDD and a round potential VSS matching it are supplied to the VDD-supplied logical operation circuits 1 and 2 and a power supply control circuit SYSC. The VDD-supplied logical operation circuits 1 and 2 are supplied with power switches SW 1 and SW 2 . Unlike them, the VCC-supplied logical operation circuit has no such power switch, but is supplied with the source voltage VCC and the ground potential VSS all the time. The power supply control circuit SYSC is also supplied with the source voltage VDD and the ground potential VSS all the time.
[0039] The VDD-supplied logical circuits 1 and 2 are configured of MOSFETs of a high threshold voltage HVth, a medium threshold voltage MVth and a low threshold voltage LVth, though this is no absolute requirement. For instance, a circuit to receive signals transmitted from other circuit blocks usually need not operate at very high speed, and therefore is configured of a MOSFET having a high threshold voltage HVth. Each internal circuit is configured of a combination of MOSFETs having a medium or low threshold MVth or LVth according to its speed requirement. Thus, while MOSFETs having a low threshold LVth are used on a signal transmission path where there are many logical steps because the delay time per logical step should be reduced, MOSFETs having a medium threshold voltage MVth are used on a signal transmission path where the number of logical steps is moderate because the delay time per logical step need not be so short, and MOSFETs of a high threshold voltage HVth are used on a signal transmission path where the number of logical steps is small because the delay time per logical step can be long.
[0040] When signals are to be communicated between the VDD-supplied logical operation circuit 1 or 2 and the VCC-supplied logical circuit, there is provided a micro input/output circuit μIO for level conversion to convert VDD-supplied small amplitude signals into VCC-supplied large amplitude signals. Since power is supplied all the time to the VCC-supplied logical circuit in this embodiment as stated above, this conversion is used for preventing propagation of unfixed levels by utilizing the micro input/output circuit μIO when power supply to the VDD-supplied logical operation circuit 1 or 2 is cut off. For this reason, the control signals SWC and INC formed by the power supply control circuit SYSC are delivered to the respective power switches SW 1 and SW 2 of the VDD-supplied logical operation circuits 1 and 2 and the input circuit as indicated by dotted lines in the diagram. The control signal INC is also delivered to the micro input/output circuit (IO as will be described afterwards.
[0041] FIG. 4 is a circuit diagram of an example of input circuit provided in the micro input/output circuit of FIG. 3 . This input circuit, receiving a VDD level input signal supplied from an input terminal in and supplies from an output terminal output a VCC level output signal having undergone level conversion. The input terminal in is connected to the input terminal of an inverter circuit NV 1 operating on the low source voltage VDD. This input terminal in is connected to the gate of an N-channel MOSFET M 2 which performs level conversion, and the output terminal of the inverter circuit NV 1 is connected to the gate of an N-channel MOSFET M 1 which performs level conversion. The ground potential of the circuit is given to the sources of these MOSFETs M 1 and M 2 , and between their drains and the high source voltage VCC are disposed P-channel MOSFETs M 3 and M 4 whose gates and drains are cross-connected. The level-converted output signal from the commonly connected drains of the MOSFETs M 2 and M 4 is supplied to one of the input terminals of the NAND gate circuit G 1 . The other input terminal of this NAND gate circuit G 1 is supplied with the control signal INC for preventing propagation of unfixed levels.
[0042] In this embodiment, when the control signal INC is set to the high level (logic 1), the gate circuit G 1 inverts the signal converted in level from the VDD level to the VCC level and delivers the inverted signal. On the contrary, when the control signal INC is set to the low level (logic 0), the output signal of the gate circuit G 1 is fixed to the high level (logic 1) irrespective of the level-converted signal. In other words, the power supply to the VDD-supplied logical operation circuit which supplies the source voltage VDD to the inverter circuit NV 1 and the input signal to the input terminal in is cut off, with the result that, even if the level-converted signal takes on an unfixed level, such as a high output impedance, the output signal of the gate circuit G 1 can be fixed to the high level (logic 1), unaffected by the unfixed level, by setting the control signal INC to the low level (logic 0). As a result, in the VCC-supplied logical circuit, inputting of any unfixed level can be prevented from inviting a through current or erroneous operation.
[0043] FIG. 5 shows the configurations of the smallest units of another semiconductor integrated circuit device pertaining to the invention. This embodiment of the invention is a variation of what is shown in FIG. 1 , and its configuration differs from that of the embodiment of FIG. 1 in that a response signal ACK matching the power supply control signal SWC is delivered from the circuit block 1 to the circuit block 3 . Receiving this response signal ACK, the circuit block 3 generates the power supply control signal SWC and the control signal INC for preventing propagation of unfixed levels matching that signal SWC. In this drawing, these signal routes are distinguished from the routes of ordinary operational signals by being indicated in dotted lines.
[0044] FIG. 6 is a waveform chart illustrating an example of operation of the circuit embodying the invention, shown in FIG. 5 . As in the configuration shown in FIG. 2 , the circuit block 3 is caused to generate the control signal INC for preventing propagation of unfixed levels; the input circuit provided in the circuit block 2 stops capturing any unfixed level or any other input signal; after forming a fixed level matching the control signal INC, the power supply control signal SWC is set to the low level to turn off the power switch of the circuit block 1 ; the source voltage VDD for instance drops, and power supply is cut off. Therefore, as in the foregoing case, even if the output signal of the circuit block 1 becomes unfixed in level as a result of the power cut-off, the circuit block 2 is maintained at the fixed level.
[0045] Then, the power supply control signal SWC is raised to the high level by the circuit block 3 to turn on the power switch of the circuit block 1 to cause the source voltage VDD, for instance, to rise. The circuit block 1 here is provided with a voltage detecting circuit, which detects the rise of the source voltage VDD and, when the voltage reaches a level required for the operation of the circuit block 1 , generates the response signal ACK. After having a power supply control circuit unit or the like generate a timing margin upon receipt of this response signal ACK, the circuit block 3 judges that the output level of the circuit block 1 is not an unfixed level, and control is so effected as to enable the signal formed by the circuit block 1 to be received by the circuit block 2 by setting the control signal INC for preventing propagation of unfixed levels to the low level.
[0046] FIG. 7 and FIG. 8 are block diagrams illustrating operating forms of an input circuit for preventing the propagation of unfixed levels according to the invention. FIG. 7 and FIG. 8 showcases wherein there is a switch over from the upper state in which power supply is on to both the circuit blocks 1 and 2 to the lower state in which power supply to only the circuit block 1 is off.
[0047] FIG. 7 (A) shows a case in which a latch circuit is used as the input circuit. This is a state in which, when power supply to both the circuit blocks 1 and 2 is on, a signal of the high level (H) is delivered from the circuit block 1 to the circuit block 2 . And when power supply to only the circuit block 1 is to be turned off as indicated by an arrow, the latch circuit fixes the high level (H) with the control signal INC for preventing propagation of unfixed levels generated before that, and outputs that signal fixed to the high level.
[0048] FIG. 7 (B) shows a case in which a logical sum type circuit is used as the input circuit. This is a state in which, when power supply to both the circuit blocks 1 and 2 is on, a high level/low level (H/L) is delivered from the circuit block 1 to the circuit block 2 . And when power supply to only the circuit block 1 is to be turned off as indicated by an arrow, a logical sum type circuit, such as a NOR circuit, fixes the low level (L) with the high level (logic 1) of the control signal INC for preventing propagation of unfixed levels generated before that, and outputs that signal fixed to the low level. Where an OR circuit, another logical sum type circuit, is used as the input circuit, the high level (H) of the signal is fixed with the high level (logic 1) of the control signal INC, and outputs that signal fixed to the high level.
[0049] FIG. 8 (A) shows another case wherein a latch circuit is used as the input circuit. This is a state in which, when power supply to both the circuit blocks 1 and 2 is on, a signal of the high level (L) is delivered from the circuit block 1 to the circuit block 2 . And when power supply to only the circuit block 1 is to be turned off as indicated by an arrow, the latch circuit fixes the high level (L) with the control signal INC for preventing propagation of unfixed levels generated before that, and outputs that signal fixed to the high level.
[0050] FIG. 8 (B) shows a case in which a logical product type circuit is used as the input circuit. This is a state in which, when power supply to both the circuit blocks 1 and 2 is on, a high level/low level (H/L) is delivered from the circuit block 1 to the circuit block 2 . And when power supply to only the circuit block 1 is to be turned off as indicated by an arrow, a logical product type circuit, such as a NAND circuit, fixes the high level (H) with the low level (logic 0) of the control signal INC for preventing propagation of unfixed levels generated before that, and outputs that signal fixed to the high level. Where an AND circuit, another logical product type circuit, is used as the input circuit, the low level (L) of the signal is fixed with the low level (logic 0) of the control signal INC, and outputs that signal fixed to the low level.
[0051] FIG. 9 is a timing chart illustrating an example of standby shifting sequence of a specific circuit block in a semiconductor integrated circuit device embodying the invention. In a device managing the whole system mounted with this semiconductor integrated circuit device pertaining to the invention, for instance a central processing unit (CPU) or the like for executing signal processing of the system in accordance with a program, when the execution of the program generates a standby control signal to instruct a specific circuit block to shift to a standby state, a power supply instruction signal is entered into this semiconductor integrated circuit device pertaining to the invention the power supply control circuit SYSC shown in the circuit block 3 raises the input control signal to the high level, and a fixed level matching the input control signal is formed for the input circuit, which is disposed in the circuit block to which power supply is to be turned on and receives a signal from the circuit block to which power supply is to be turned off.
[0052] After an operation to forbid propagation of signals of unfixed level is executed by the high level of such an input control signal, an instruction to cut off power supply by setting the power supply control signal to the low level is given from the power supply control circuit SYSC to the circuit block to which power supply is to be turned off. In the circuit block to which power supply cut-off has been instructed, a power supply cut-off sequence in which the power switch is turned off to match the low level of the power supply control signal is executed. For this reason, the circuit block to which power supply is to be turned off is provided with a circuit which, as will be described afterwards, is supplied with power all the time and performs control turn on and off power supply. This power supply cut-off sequence is communicated to the power supply control circuit SYSC by the low level of the power supply acknowledge signal. And in the power supply control circuit SYSC, a power supply cut-off confirm signal is communicated to, among others, the CPU having issue the standby control signal.
[0053] FIG. 10 is a timing chart illustrating an example of return from standby sequence of the specific circuit block in the semiconductor integrated circuit device pertaining to the invention. As in the foregoing case, when standby control signal to instruct the specific circuit block to return from a standby state is generated by the execution of the program by the central processing unit (CPU) or the like managing the whole system, a power supply instruction signal is inputted to this semiconductor integrated circuit device pertaining to the invention, an instruction to turn on power supply is given by delivering a power supply control signal set to the high level from the power supply control circuit SYSC shown as the circuit block 3 to the circuit block to which power supply is to be turned on. In the circuit block to which power supply has been instructed, a power supply duration by which the power switch is to be turned on to match the high level of the power supply control signal is executed by the circuit described above. And, after waiting for a certain period which power turning-on is completed, the input control signal is reduced to the low level, and the input circuit performs an operation capture into the circuit block 2 a signal from the circuit block to which power supply has been turned on. Then, though not shown, the power supply acknowledge signal is also delivered to the power supply control circuit SYSC to inform the CPU or the like, which has issued the standby control signal, of the control of the generation of the input control signal and a power supply turn-on confirm signal.
[0054] FIG. 11 is a schematic block diagram of a whole system pertaining to the invention corresponding to FIG. 9 and FIG. 10 . An instruction to place a specific circuit block in a standby state is given to the circuit block 3 with signals A and B from a device managing the standby mode, typically a CPU. The module to manage the standby mode is not limited to the CPU, but may be any appropriate module. The signals A and B correspond to, for instance the standby control signal and the power supply instruction signal shown in FIG. 9 and FIG. 10 above. The circuit block 3 forms the power supply control signal SWC correspondingly to such signals A and B, and delivers them to a power switch controller PSWC. The power switch controller PSWC, as will be described afterwards, is a circuit appended to the circuit block 1 placed in the standby state, and returns to the circuit block 3 a control signal for performing on/off control of the power switch provided for the circuit block 1 and the response signal ACK matching the power supply control signal SWC. Whereas power switch controller PSWC is contained in the circuit block 1 in FIG. 1 , FIG. 5 and other drawings above, since a voltage is constantly supplied to it, it is shown as a separate circuit block from the circuit block 1 in FIG. 11 to make clear this constant voltage supply.
[0055] Signals formed in the circuit block 1 are communicated to the circuit block 2 . The circuit block 2 is provided with the input circuit for receiving signals delivered from the circuit block 1 , and is controlled with the control signal INC for preventing propagation of unfixed levels generated in relation to the power supply control signal SWC. Thus, before power supply to the circuit block 1 is cut off with the power supply control signal SWC, the level of the signal to be delivered to the circuit block 2 is fixed as stated above with such control signal INC to prevent in advance the unfixed level (Hiz) accompanying the power supply cut-off from being communicated. Between the circuit block 3 and the CPU and the like, signals C, D, E and so forth are exchanged. These signals C, D and E are signals required by the CPU or the like executing the program for reliably controlling the operation of the whole system, such as a power supply cut-off confirm signal, a return from standby signal or a standby release signal.
[0056] FIG. 12 is a schematic block diagram of one example of semiconductor integrated circuit device pertaining to the invention. This is a variation of the embodiment shown in FIG. 1 above, with a circuit block 4 being added. Although this circuit block 4 delivers signals to the circuit block 1 and the circuit block 2 , neither of the two circuit blocks 1 and 2 delivers signals to it. To the circuit block 1 , signals are delivered only from the circuit block 4 . To the circuit block 2 , signals are delivered from both the circuit blocks 1 and 4 . An input circuit or circuits are provided to match signals delivered in this way to each block. Thus, the circuit block 1 is provided with one input circuit to match signals from the circuit block 4 , and the circuit block 2 is provided with two input circuits to match signals from the circuit blocks 1 and 4 .
[0057] Therefore, the circuit block 3 generates two kinds of signals for preventing propagation of unfixed levels, the control signals INC 1 and INC 4 , to match power supply cut-off to the circuit blocks 1 and 4 . Thus, when power supply to the circuit block 4 is to be turned off, correspondingly the control signal INC 4 is generated to control the input circuits of the circuit blocks 1 and 2 to prevent any unfixed level from the circuit block 4 . When power supply to the circuit block 1 is to be turned off, correspondingly the control signal INC 1 is generated to control the input circuit of the circuit block 2 to prevent any unfixed level from the circuit block 1 . As the circuit block 2 delivers signal to neither of the circuit blocks 1 nor 4 , there is no need to generate a matching control signal INC for preventing propagation of unfixed levels. Further, even the circuit block 4 , which does receive signals from other circuit blocks land 2 as illustrated in the drawing, requires no input circuit for preventing propagation of unfixed levels on condition that power supply to it is off whenever that to other circuit blocks 1 and 2 is off.
[0058] FIG. 13 is a schematic block diagram of another semiconductor integrated circuit device pertaining to the invention. This is a variation of the embodiment shown in FIG. 12 above, in which signals are delivered to the additional circuit block 4 from the circuit block 1 . Matching such signals delivered from the circuit block 1 , an input circuit is disposed in the circuit block 4 . In this embodiment, the relationship between the circuit blocks 1 and 4 is different from that in FIG. 12 above, and power supply to the circuit block 1 is allowed to be turned off when that to the circuit block 4 is on. Therefore in the circuit block 3 , in the same way as described above, when power supply to the circuit block 1 is to be turned off, correspondingly the control signal INC 1 is generated to control the input circuits of the circuit blocks 2 and 4 to prevent any such unfixed level from the circuit block 1 .
[0059] FIG. 14 is a schematic block diagram of still another semiconductor integrated circuit device pertaining to the invention. This is a variation of the embodiment shown in FIG. 12 above, in which signals are delivered to the additional circuit block 4 from not only the circuit block 1 but also the circuit block 2 . Also, the circuit block 2 delivers signals to the circuit block 1 . Furthermore, the circuit block 3 is provided with a logical circuit which in its operation receives signals from the circuit blocks 1 , 2 and 4 in addition to the aforementioned power supply control circuit SYSC. Viewed the other way around, if there is a specific circuit block 3 which can keep the power supply control circuit SYSC supplied with power all the time, it will be incorporated there. Such a circuit block 3 is provided with three input circuits to match signals from the circuit blocks 1 , 2 and 4 .
[0060] Therefore, the power supply control circuit SYSC of the circuit block 3 generates three kinds of signals for preventing propagation of unfixed levels, the control signals INC 1 , INC 2 and INC 4 , to match power supply cut-off to the circuit blocks 1 , 2 and 4 . When power supply to the circuit block 1 is to be turned off, correspondingly the control signal INC 1 is generated to control the input circuits of the circuit blocks 2 , 3 and 4 to prevent any such unfixed level from the circuit block 1 . When power supply to the circuit block 2 is to be turned off, correspondingly the control signal INC 2 is generated to control the input circuits of the circuit blocks 1 , 3 and 4 to prevent any such unfixed level from the circuit block 2 . And when the circuit block 4 is to be turned off, correspondingly the control signal INC 4 is generated to control the input circuits of the circuit block 1 , 2 and 3 to prevent any such unfixed level from the circuit block 4 . In this manner, power supply to any of the circuit blocks 1 , 2 and 4 , but not the circuit block 3 , can be turned off as desired, and correspondingly the control signals INC 1 , INC 2 and/or INC 4 are generated in advance.
[0061] FIG. 15 is a schematic layout of another example of semiconductor integrated circuit device pertaining to the invention. The layout in this drawing centers on power supply lines formed in the semiconductor integrated circuit device pertaining to the invention. The power supply lines comprise a pair of a source voltage line and the ground wire of the circuit, and the latter is hatched to make the wiring layout more easily perceivable.
[0062] The semiconductor integrated circuit device of this embodiment is designed to operate on two kinds of source voltages, vcc and vdd. The source voltages vcc are relatively high, such as 3.3 V, and the source voltages vdd are relatively low, such as 1.2 V, though these are not absolutely required. The relatively high source voltages vcc have a source voltage vccaa for analog and logical units, a source voltage vccq for input/output circuits and a source voltage vcci for internal circuits. Respectively matching these source voltages vccaa, vccq and vcci, there are provided circuit ground potentials vssaa, vssq and vssi. The power supply lines expressed in bold wiring lines along the outer circumference of the semiconductor chip are bisected into one for analog circuits and the other for digital circuits; the source voltages vccaa and vccq are arranged outside, and inside the respective ones of them are arranged circuit ground vssas and vssq. As vcc-supplied internal circuits each having a specific circuit function, there are a vcc-supplied logical unit and an analog logical unit, and power supply lines represented by fine wiring lines surround each. The power supply lines surrounding the vcc-supplied logical unit are connected to power supply pads vcci and vssi. The power supply lines surrounding the analog logical unit, together with the bold power supply lines, are connected to power supply pads (PAD) vccaa and vssaa.
[0063] There are disposed two kinds of power supply lines vdd and vss, including what are represented by thin ring-shaped ones along the inside of the power supply line represented by bold wiring lines and what match the internal circuits to be described afterwards. The vdd-power supply lines arranged in a ring shape are used for supplying the operating voltage of a level converting circuit for converting vdd-internal signals into large amplitude signals, such as the vcc signals in an input/output interface and operating voltages including those for the vdd-supplied internal circuits operating all the time, such as micro io exchanging signals among a vdd-supplied logical unit 1 , a vdd-supplied logical unit 2 and a vcc-supplied logical unit. The vdd-supplied internal circuits include the vdd-supplied logical unit 1 and the vdd-supplied logical unit 2 . Surrounding these circuit blocks, power supply lines represented by thin wiring lines are disposed. The vdd-supplied logical unit 2 is provided with independent power supply pads (PAD), such as vddi and vssi, for the purpose of noise separation between the vdd-supplied logical unit 1 and the internal circuits operating on the ring-shaped power supply lines.
[0064] Matching the power supply lines, power supply pads (PAD) vcc and vss, vdd and vss, vccq and vssq, vccaa and vssaa are disposed, each in a plurality of sets as required. Among other pads (PAD) illustrated as representative ones, aio are intended for inputting/outputting analog signals, and vdd-dio are intended for direct digital inputting/outputting between the vdd-supplied logical unit 1 and the vdd-supplied logical unit 2 . Illustration of vcc-supplied pads for signal inputting/outputting is dispensed with in this drawing. The rectangular blocks shown correspondingly to the pads constitute input/output interface circuits. Signal input/output pads matching the input/output interfaces are represented by such typical examples as the pads dio and aio. In particular, input/output pads for digital signals are disposed in a large number, along with power supply pads, surrounding the outer circumference of the semiconductor chip.
[0065] In this embodiment, the internal circuit blocks of the vdd-supplied logical unit 1 and the vdd-supplied logical unit 2 are provided with a function to enter a power saving mode when no operation is done even though power supply is on. In order to realize this power saving mode, power switches PSW are disposed underneath the power supply lines formed to surround the internal circuits, and power switch control circuits PSWC are arranged underneath the corners of the power supply lines. Furthermore, power supply main lines (vcc and vss, vdd and vss, vccq and vssq, vccaa and vssaa) formed to surround the respectively matching circuits in order to reduce the impedances of the power supply lines to be described afterwards among other purposes are formed of relatively thick aluminum pad wires ALP, formed in the same process as the bonding pads.
[0066] FIG. 16 is a layout of one example of power supply lines matching the vdd-supplied logical unit 2 in FIG. 15 . In this embodiment, the power supply lines are configured in a cell form. The variety of cells, though not limited, can be prepared in four types, A through D, broadly classified. In the directions of letters A through D, the cells C constitute power supply lines extending in the longitudinal direction. The cells B constitute power supply lines extending in the lateral direction. The cells A constitute corners formed by the longitudinal and lateral power supply lines. The cells B include standard cells and mini-cells B for length adjustment, though this differentiation is not absolutely necessary.
[0067] The cells E constitute power supply lines extending in the longitudinal direction above the part where the vdd-supplied logical unit 2 is formed, and connect the opposite cells B. These cells E are used for configuring a power supply mesh to be described afterwards. The cells D, which are internal linking cells, extend in the lateral direction from the power supply lines extending in the longitudinal direction, and are used for linking with the internal power supply lines of the internal circuits. Circuit elements constituting the power switch elements and power switch control circuits are arranged underneath the cells A, B and C out of these cells A through E. Unlike them, the cells E are only for power supply lines. The cells D are provided with under-layer wiring for linking with internal power supply lines.
[0068] FIG. 17 is a schematic layout of one example of lower part of the power supply line matching the vdd-supplied logical unit 1 in FIG. 15 . In this embodiment, the relationship between the cells C and the cells A is mainly illustrated. The cells C are provided with switches. Each of these switches is connected at one end to the ground wire vssi of the circuit out of the source voltage lines vddi and vssi disposed above and at the other end to a ground wire for supplying the ground potential of the circuit to the internal logic area, though these connections are not the only possible ones. In the internal logic area, there is a laterally wide well area in which P-channel MOSFETs and N-channel MOSFETs constituting CMOS logical circuits like gate arrays are formed, though this is not the only possible arrangement, and switches are disposed correspondingly along this well area. Along the P-type well in which the N-channel MOSFETs are formed, the ground wires vss of the internal circuits are arranged in the lateral direction. On the other hand, along the N-type well in which P-channel MOSFETs are formed, power supply lines vdd are arranged in the lateral direction. In this drawing, the blocks dividing the internal logic area longitudinally and laterally match the respective circuit areas in which the N-channel MOSFETs and the P-channel MOSFETs are formed.
[0069] In the cell A arranged at the top left corner, there is disposed a power supply SW controller (power switch control circuit PSWC) for the on/off control of the switches provided in the cells C. Switch control signals formed by this power supply SW controller are delivered to individual switches via the power supply SW control signal lines indicated by dotted lines in the drawing. In this drawing, the power supply SW control signal lines for controlling the power SWs (switches) disposed in the cells C arranged to the left of the internal logic area deliver signals to the switches in the cells C by utilizing wiring areas disposed in these cells C.
[0070] The power supply SW control signal lines for controlling the power supply SWs disposed in the cells C arranged to the right of the internal logic area deliver signals to the switches in the cells C arranged to the right by utilizing wiring areas disposed in the cells B and wiring areas disposed in the cells A. Since these switches are intended for controlling power supply to the internal circuits as stated above, no such switches are needed in the corners. Therefore, by arranging the power supply SW controller (power switch control circuit PSWC), the circuit formation area underneath the power supply lines is effectively utilized.
[0071] Out of the switches disposed in the cells C as described above, those for supplying the ground potential of the circuit are provided correspondingly to internal ground wires matching the laterally wide P-well area in which N-channel MOSFETs are formed. Therefore, in the unoccupied areas of the cells C matching the N-type well area in which P-channel MOSFETs are formed, capacitors can be disposed for use in stabilizing power supply. Similarly, capacitors can also be disposed in the cells B underneath the power supply lines.
[0072] FIG. 18 is a circuit diagram illustrating the relationship among the power supply SW controller (PSWC), the power supply SW and the internal logic in FIG. 17 . An inverter circuit shown as representing the internal logic works on the operating voltage transmitted via the power supply line vdd and the internal ground wire vssm. On the power supply line vdd of the internal logic, the source voltage supplied from the aforementioned external terminal is constantly delivered via the pads and wiring routes. The internal ground wire vssm is connected to the ground wire vss formed to surround the internal circuits via the N-channel MOSFETs Q 1 and Q 2 as power supply SWs (switches) illustrated as being representative. The gates g of the MOSFETs as the plurality of switches provided to match the cells C are commonly supplied with the power supply SW control signal.
[0073] The power supply SW controller (PSWC) generates switch control signals for the MOSFETs Q 1 and Q 2 and the like in response to a control signal req. If the MOSFETs Q 1 and Q 2 are switched over from the off state to the on state at high speed in the internal logic, currents will flow simultaneously in the inverter circuit, logical gate circuits and the like in the internal logic on account of the input signal being unfixed and other reason, giving rise to large noise in the source voltage vdd the ground potential vss of the circuit or imposing the burden of large instantaneous current supply on the power supply unit of the system. In view of this problem, in this embodiment, power supply SW control signals to drive the MOSFETs Q 1 and Q 2 in two separate stages are generated by two driving circuits C 1 drv and C 2 drv, output circuits C 1 and C 2 thereby caused to generate output signals, a decision circuit C 3 for determining the level of the power supply SW control signals and a timer circuit Timer.
[0074] When the control signal req instructs an action to turn on power supply, the driving circuit C 1 drv in response raises the gate voltages of the MOSFETs Q 1 and Q 2 as the power switches through the output circuit C 1 . The output circuit C 1 is formed of a MOSFET whose current supply capacity is small, and the connection of the gates g of the MOSFETs Q 1 and Q 2 and so forth as a large number of power switches results in a gradual rise in the level of the power supply SW control signal line having a large load capacity. The MOSFETs Q 1 and Q 2 and so forth as power switches are thereby so controlled as to let flow relatively small currents when their gate voltage reaches or surpasses the threshold voltage. It is thereby made possible to prevent the aforementioned problem of giving rise to large noise in the source voltage vdd and the ground potential vss of the circuit or imposing the burden of large instantaneous current supply on the power supply unit on account of the input signal being unfixed in the inverter circuit or the logical gate circuits of the internal logic. To add, as the occurrence of noise is likely to adversely affect other logical circuits, interface circuits and analog circuits in operation, this is a problem that has to be taken into consideration where the system is to be equipped with a function to shift to a power saving mode by cutting off power supply to some circuit when no action is to be done on that circuit.
[0075] The timer circuit Timer actuates the output circuit C 2 via the driving circuit C 2 drv when the voltage decision circuit C 3 having hysteresis characteristics determines that the power supply SW control signal line has reached or surpassed a certain level. The output circuit C 2 is formed of a MOSFET whose current supply capacity is large, and raises the level of the gates g of the MOSFETs Q 1 and Q 2 at high speed as a large number of power switches to the source voltage vdd. This places the vdd-internal logic in an operating state. The timer circuit Timer supplies with a delay in time a signal ack indicating the validity of the operation of the internal logic and informs other circuits of this validity. A signal cds/cdr, which is a signal for controlling the micro io, is used to limit the signal output conveyed to the micro io, for instance, until the signal of the internal logic is found valid. The signal ack can be used as the response signal ACK.
[0076] FIG. 19 is a schematic layout of one example of cell C. In FIG. 19 , the power supply lines of the top layer and an element-formed part underneath them are shown one over the other. The lower part of the drawing shows the power supply lines of the top layer, wherein vdd and vss are paired. In this embodiment the power supply lines vdd and vss are formed of relatively thick aluminum layers (ALP), formed in the same process as the bonding pads. The core side is the side of the internal logic area, and the pad metal wiring on the core side can be varied to match the potentials to be connected into, such as vdd, vss and vssm.
[0077] The upper part of the drawing shows the element-formed part, wherein a plurality of gate electrodes extending in the lateral direction are disposed, arrayed in the longitudinal direction. Diffusion layers constituting sources and drains are formed, sandwiched between the gate electrodes. The diffusion layers sandwiched between the two gate electrodes constitute the common sources or drains of the MOSFETs having the two gate electrodes, and the sources and drains are alternately arranged with the gates between them. On the I/O side (right-hand side), every other diffusion layer is made a common source and connected to the power supply line vss. On the core side, every other one of the different diffusion layers from the above is made a common drain and connected to the vssm metal wiring, which is the ground wiring of the internal logic circuit. On the right hand side in the cell frame, a plurality of wiring layers extending in the longitudinal direction are provided to be used as wiring between the corner control circuits and as wiring for conveying power supply SW control signals.
[0078] FIG. 20 shows a schematic structural section of one example of power supply line of the semiconductor integrated circuit device pertaining to the invention. In FIG. 20 , a supply route of the source voltage vdd is illustrated as a representative of the routing. Thick bonding pads consisting of aluminum or the like are connected to a copper wiring layer. On one hand it is connected to a power supply main line ALP consisting of aluminum or the like and formed in the upper layer, and on the other hand it is connected via the wiring layer and contacts disposed in the lower layer to the N-type well area Nwin which P-channel MOSFETs are formed. This configuration places in a parallel relationship the power supply main line consisting of the lower wiring layer of copper and the upper wiring layer of aluminum. This causes the currents needed for the operation of the internal logic to flow divided between those two power supply routes, more of them flowing on the main line side to enable the impedance of the power supply line low. As a result, unevenness or variations of the source voltage in individual logical circuits while the internal logic is operating can be restrained. Since unevenness or variations of the source voltage greatly affects circuit operation when the internal logic is operating at a low voltage, such as the aforementioned 1.2 V (or even below), this embodiment can be expected to enable the internal logic circuits to operate stably. This also holds true of the ground wiring which provides the ground potentials of the circuits.
[0079] FIG. 21 is a circuit diagram of one example of step-down power supply circuit to be mounted on the semiconductor integrated circuit device pertaining to the invention. In this embodiment, in the semiconductor integrated circuit device shown in FIG. 3 or FIG. 15 above, besides a low voltage VDD supplied from an external terminal, a high voltage VCC is supplied from outside and reduced to VDD by the step-down power supply circuit illustrated therein and delivered to internal circuits. Further, a power switch function is added to this voltage step-down circuit.
[0080] The collectors and bases of the transistors Q 1 and Q 2 and connected to the ground potential points of the circuit. The size (emitter area) of the transistor Q 2 is made N times as large as that of the transistor Q 1 and the current flowing to the emitter of the transistor Q 1 is N times as dense as that flowing to the emitter of the transistor Q 2 to keep constant the voltage difference between the base and the emitter matching the silicon band gap. One end of a resistor R 6 is connected to the emitter of the transistor Q 2 , and control is so performed with a differential amplifier to equalize the potential of the node N 1 of the emitter of the transistor Q 1 and that of the node N 2 at the other end of the resistor R 6 .
[0081] Thus the voltages of the nodes N 1 and N 2 are entered into the differential amplifier, its output voltage VRO is fed back to the nodes N 1 and N 2 via the resistors R 4 and R 5 , a constant voltage matching the silicon band gap is supplied to the resistor R 6 , a constant current is let flow to the resistor R 6 , and control is so effected as to make the output voltage VRO a constant voltage (reference voltage) matching the silicon band gap by letting this constant current to the resistor R 5 . The resistors R 5 and R 4 , by utilizing their positive temperature characteristics, compensate for the negative temperature characteristics of the base-emitter voltages of the transistors Q 1 and Q 2 . The reference voltage VRO is about 1.1 V.
[0082] The differential amplifier is configured of the following circuit elements. P-channel type MOSFETs MP 6 and MP 7 are connected in a differential form. The gates of the differential MOSFETs MP 6 and MP 7 are connected to the nodes N 1 and N 2 . AP-channel MOSFET MP 4 , constituting a current source, is disposed between the common source of the differential MOSFETs MP 6 and MP 7 and the source voltage VDD or the circuit. Diode-form N-channel MOSFETs MN 4 and MN 5 are disposed between the drains of the differential MOSFETs MP 6 and MP 7 and the ground potential of the circuit. The diode-form N-channel MOSFETs MP 4 and MP 5 are provided with N-channel MOSFETs MN 3 and MN 6 in the current mirror form. This causes a current matching the drain current of the MOSFET MP 6 to be supplied from the drain of the MOSFET MN 3 .
[0083] The drain current of the MOSFET MN 3 is supplied via a current mirror circuit consisting of P-channel type MOSFETs MP 2 and MP 3 . The output current is supplied to the drain of the MOSFET MN 6 . As a result, a differential current between the drain currents of the differential MOSFETs MP 6 and MP 7 is caused to flow to the commonly connected drain of the MOSFETs MP 3 and MN 6 . The common connection point of the MOSFETs MP 3 and MN 6 is connected to the gate of a P-channel MOSFET Q 8 . The drain of this MOSFET MP 8 is connected to the resistors R 4 and R 5 to constitute the output voltage VRO.
[0084] A resistor R 1 and a diode-form N-channel MOSFET MN 1 are connected between the source voltage VDD and the ground potential of the circuit. An N-channel MOSFET MN 2 is connected to this MOSFET MN 1 in the current mirror form. A diode-form P-channel MOSFET MP 1 is disposed between the drain and source voltage of this MOSFET MN 2 , and the connection of this MOSFET MP 1 and the MOSFET MP 4 in the current mirror form causes a current matching a current formed by the resistor R 1 to serve as the bias current for the differential MOSFETs MP 6 and MP 7 .
[0085] The transistors Q 1 and Q 2 are configured by using the CMOS process. They may be lateral transistors each having N-type source and drain regions constituting an N-channel MOSFET, formed by the CMOS process, as its collector and emitter and having a P-well base; or vertical transistors each having an N+ region constituting the source and drain regions of an N-channel MOSFET as its emitter, having the P-type well where it is formed as its base, and an N-type deep well for separating the P-type from a P-type substrate (PSUB) as its collector. In this way, a highly accurate reference voltage hardly affected by the offset of the CMOS differential amplifier circuit is obtained, and it is made possible to form the circuit by the CMOS process.
[0086] The reference voltage VRO is supplied, though not absolutely required, to the input terminal (−) of a differential amplifier circuit OP. The output signal of this differential amplifier circuit OP is communicated to the gate of a P-channel output MOSFET MP 10 . A stepped-down output voltage VDD is supplied from the drain of this P-channel MOSFET MP 10 . This output voltage VDD is divided by feedback resistors R 7 and R 8 disposed between the drain and the ground potential of the circuit, and the resultant divided voltages are inputted to the feedback terminal (+) of the differential amplifier circuit OP to form an output voltage VDD resulting from the amplification of the reference voltage VRO correspondingly to the ratio of voltage division.
[0087] In this embodiment, in order to add a switching function, a control signal/POFF is supplied to the gate of an N-channel MOSFET MN 7 to which the operating current of the differential amplifier circuit OP is let flow. Further, a P-channel MOSFET MP 9 is disposed between the gate of the P-channel output MOSFET MP 10 and the source voltage VCC, and the control signal/POFF is supplied to the gate. One silicon band gap circuit, though not necessarily limited to one, to generate the reference voltage VRO is disposed in the semiconductor integrated circuit device, and the differential amplifier circuit OP and the output MOSFET MP 10 are provided corresponding to the circuit blocks 1 , 2 and 4 having the power turning-off function.
[0088] When the source voltage VDD is to be supplied to a specific circuit block, the control signal/POFF is raised to the high level. The MOSFET MN 7 is turned on, and an operating current islet flow to the differential amplifier circuit OP. On this occasion, the P-channel MOSFET MP 9 is turned off. When the supply of the source voltage VDD to a specific circuit block is to be cut off, the control signal/POFF is lowered to the low level. This causes the MOSFET MN 7 to be turned off, and the differential amplifier circuit OP is placed in a non-operating state. Then P-channel MOSFET MP 9 is in an on state and the MOSFET MP 10 securely turned off to cut off the source voltage VDD.
[0089] FIG. 22 is a circuit diagram of another example of step-down power supply circuit to be mounted on the semiconductor integrated circuit device pertaining to the invention. This embodiment has a configuration in which, besides the configuration of the semiconductor integrated circuit device shown FIG. 3 or FIG. 15 wherein the low voltage VDD is supplied from the external terminal, a high voltage VCC is supplied from outside and reduced to VDD by the step-down power supply circuit illustrated therein and delivered to internal circuits. Further, a power switch function is added to this voltage step-down circuit. The power switch in this embodiment is not to cut off the source voltage VDD as in the foregoing embodiments, but is reduced to or below the lower voltage limit of the internal circuits.
[0090] Thus, a bias current is regularly supplied to the differential amplifier circuit OP by the N-channel MOSFET MN 7 . A P-channel MOSFET MP 11 to short-circuit the two ends of the voltage dividing resistor R 7 is disposed, though not absolutely required, to supply the aforementioned control signal/POFF to its gate. In this configuration, the reduction of the control signal/POFF to the low level causes the two ends of the resistor R 7 to be short-circuited to achieve 100% feedback of the output voltage VDD for operation as a voltage follower circuit. This reduces the source voltage VDD to a voltage matching the reference voltage VRO. The source-voltage of the logical circuits is thereby reduced to or below the lower limit of the operating voltage, and this drop in voltage can help reduce the flowing leak current. As the operation of the logical circuits at or below the lower limit of the voltage may invite unfixed levels, there is provided an input circuit for preventing the propagation of unfixed levels as in the foregoing embodiments.
[0091] This power supply cut-off system enable a device having storage circuits, such as memories or registers, to retain the stored information while reducing the leak current from power supply. For static memory cells, registers using flip-flop circuits or latch circuits, if the purpose is simply to hold stored information, about half of that lower limit operation would suffice. Then, by significantly reducing the source voltage to a voltage level which meets the information holding purpose alone, the leak current can be reduced from circuit blocks to which power supply cannot be turned off as stated above. Where the reference voltage VRO is outputted as it is as in the embodiment shown in FIG. 22 , the voltage cannot be reduced to around 1.1 V. Then, it is also possible to dispose a voltage dividing circuit on the input side of the differential amplifier circuit OP 2 and divide the voltage VRO itself to reduce the source voltage VDD to the desired low level.
[0092] Referring to FIG. 21 and FIG. 22 above, instead of directly using the output voltage VDD of the MOSFET MP 10 as the operating voltage for the circuit blocks, it can be used as the source voltage for the circuit blocks by using an output buffer of a voltage follower type. In this case, where a switching function is to be added as in the embodiment of FIG. 21 , a power-off state can be forcibly achieved by cutting of the operating current of the output buffer and short-circuiting the gate and source of the output MOSFET. In this case, the operating current of the differential amplifier OP can also be cut off. Where the same stepped-down voltage VDD is to be used in a plurality of circuit blocks, the differential amplifier can be used in common, with an output buffer provided for each block. Where the output voltage is to be brought down to the lower limit of the operating voltage as in the configuration of FIG. 22 above, a silicon band gap circuit can be used in common, with each circuit block provided with an amplifier circuit having the aforementioned level switching function and an output circuit.
[0093] FIG. 23 is an overall block diagram of another example of semiconductor integrated circuit device pertaining to the invention. This embodiment represents a conceptual configuration of the invention as applied to, for instance, an information processing device, in particular a system LSI (or microprocessor; the same applies hereinafter).
[0094] In the system LSI of this embodiment, each circuit block has a power switch PSW or VGC. The individual circuit block may be a central processing unit (CPU), peripheral circuit modules IP 1 and IP 2 or a clock generator circuit CPG, to each of which power supply is turned on and off with a power switch PSW. Other available circuit blocks include internal memories URAM and backup registers BUREG, each reducing the leak current while keeping the operation to hold stored information with a power switch VGC against the voltage drop as shown in FIG. 22 . Power supply to a standby control circuit STBYC is on all the time, matches the circuit block 3 as in 14 above, and is provided with the power supply control circuit SYSC.
[0095] The CPU controls the system LSI as a whole. The peripheral circuit module IP 1 , though not limited to this function, is a peripheral circuit module which is not required when the CPU for an MPEG accelerator or the like fetches an instruction. The peripheral circuit module IP 2 , which may be a bus state controller or the like, is a peripheral circuit module which is required when the CPU fetches an instruction though not limited to this function. To the system bus BUS, various circuit modules including the CPU are connected, and includes a data bus and an address though not shown. The clock generator circuit CPG, receiving a clock signal RCLK, generates an internal clock signal ICLK. The internal clock signal ICLK is supplied to various circuit modules, and the system LSI operates in accordance with the internal clock signal ICLK. The URAM, a large-capacity internal memory, holds necessary information including data currently being processed. The backup register BUREG is used, when in the standby mode, for holding the values of register REG included in the peripheral circuit modules IP 1 and IP 2 .
[0096] When a given program is to be executed by the system LSI, if there is a circuit block placed in the standby state, an instruction will be given to cut off power supply to or reduce the voltage for this circuit block. In advance of instructing a power supply cut-off or a voltage reduction, the control signal INC for preventing propagation of unfixed levels is generated and deliver to circuit blocks to which power supply is on. This serves to reduce the leak current in the circuit block to which power supply is turned off, and the circuits to which power supply is on and which are used for executing the program can perform, while preventing any through current from being generated by the input of any unfixed level, their signal processing operation matching the program without committing errors due to any unfixed level from the circuit block to which power supply is off. Further, when power supply to the CPU or peripheral circuit modules IP 1 and IP 2 is to be turned off, necessary internal information therein is saved into the. The URAM or the backup register BUREG holding such saved information can also be placed in the standby state with a voltage drop as described above it is no longer accessed.
[0097] Although the invention made by the present inventors has been hitherto described in specific terms with reference to some of the embodiments thereof, the invention is not confined to these embodiments, but various modifications are possible without deviating from its true spirit and scope. For instance, power switches can be disposed on the source voltage side of the circuit instead of the ground potential side as described above. Propagation of unfixed levels can as well be prevented by, instead of providing the micro I/O circuit with a gate circuit as in the embodiment shown in FIG. 4 , providing the VCC-supplied logical circuit with an input circuit for preventing the propagation of unfixed levels as stated above. The circuit for preventing the propagation of unfixed levels can be, instead of using the latch circuit or logical gate circuits as described above, may forbid transmission of any unfixed level with a transmission gate MOSFET and providing a pull-up or pull-down MOSFET on the part of the signal-receiving circuit block. For instance, by using an N-channel MOSFET as the transmission gate MOSFET and the P-channel MOSFET as pull-up means, it is made possible to supply the control signal INC for preventing propagation of unfixed levels to the gate electrodes of the two MOSFETs. The invention can be extensively utilized in semiconductor integrated circuit devices each having a plurality of functional blocks such as microcomputers or system LSI.
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A semiconductor integrated circuit device enhanced in design efficiency while achieving multi-functionalization and power saving is to be provided. The semiconductor integrated circuit device has a first through third circuit blocks, and is placed in a first power supply state in which the operation of internal circuits in the first circuit block is guaranteed in accordance with an instruction from the third circuit block or a second power supply state in which the operation of the internal circuits is not guaranteed, wherein the second circuit block has an input unit which receives signals supplied from the first circuit block, and the input unit of the second circuit block has an input circuit which, in accordance with the control signal which was responded to when the second power supply state was instructed by the third circuit block to the first circuit block, causes a specific signal level to be maintained in compliance with the operating voltage of the second circuit block irrespective of the signal supplied from the first circuit block.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a plurality of articulable links to extend the capable distance of movement of components of a medical device. This application is a continuation-in-part application of copending U.S. patent application Ser. No. 10/158,726 filed 30 May 2002 entitled “Medical Clip Applying Device” which is a continuation-in-part of U.S. patent application Ser. No. 10/085,737 entitled “Medical Clip Applier with Safety Arrangement” filed 28 February 2002 which is a continuation-in-part application of U.S. patent application Ser. No. 09/934,378 entitled “Safety Locking Mechanism for a Medical Clip Device” filed 21 August 2001, which is a continuation-in-part of U.S. patent application Ser. No. 09,795,808 entitled “Release Mechanism for a Grasping Device” filed 28 February 2001 which is a continuation-in-part of U.S. Pat. No. 3,306,149 entitled “Medical Clip Device with Cyclical Pusher Mechanism” which is a division of U.S. Pat. No. 6,277,131 entitled “Ladder Type Medical Clip Feeding Device”, all of which are incorporated herein by reference, in their entirety.
[0003] 2. Prior Art
[0004] Typical modem surgery may be identified as laparoscopic surgery, which may be defined as minimally invasive surgery upon a patient utilizing small or miniaturized medical devices by which body tissue is cut, removed or cauterized by small manipulable devices through small incisions or openings within the patient's body. A grasper or dissector is one such tool for that type of surgery. Such a device may be utilized to grab, dissect, treat or move tissue out of the surgical situs where other tissue may be surgically treated.
[0005] Such devices may be seen in the aforementioned U.S. Pat. No. 6,277,131 to Kalikow and U.S. Pat. No. 6,306,149 to Meade. These devices have a handle assembly into which an elongated tubular housing is attached. The elongated housing has a distalmost end with a set of pinching jaws thereon. The pinching jaws in this example are utilized to crimp a clip so as to crimp a mammalian tissue. The jaws are activated by squeezing a trigger on the housing assembly on the proximal end of the device. Such a squeezing trigger motion effects the pinching of the jaws together on a staple-like clip. Should it be desired to utilize a longer legged clip to be pinched within the jaws of that crimping device, longer legged staples would jam such a mechanism and the jaws unfortunately would likely not be able to tolerate such a pinching or squeezing effect.
[0006] It is an object of the present invention to provide a multiplier extension arrangement on a medical device to permit that medical device to have a longer reach or extendibility thereof.
[0007] It is a further object of the present invention to provide a multiplier extension arrangement which permits a first or forward motion to be converted into a larger second or forward motion and a first or rearward or proximal motion to be converted into a larger rearward or proximal motion relative to an output end of the multiplier extension apparatus.
[0008] It is a further object of the present invention to provide an arrangement for permitting longer legged staples or clips to be utilized in a standard triggered-housing assembly of a clip applying device.
[0009] It is a further object of the present invention to provide a gain of displacement or distance in a linear tool of a given length, to permit a short-distance traveling bearing to advance a longer legged clip or staple.
[0010] It is an object of the present invention to permit the use of the proximal handle (and bearing arrangement) of a “regular” clip applier device with a replacement barrel and clinch jaw arrangement including an extender arrangement to permit larger clips to be properly utilized with that regular clip applier device without having to purchase an entirely new applier device.
[0011] It is still yet a further object of the present invention to overcome the disadvantages of the prior art.
BRIEF SUMMARY OF THE INVENTION
[0012] The present invention comprises a hand manipulable clip applying device for applying medical tissue pinching clips to mammalian tissue. The clip applying device has a patient engaging distalmost end with a pair of squeezable jaws arranged on the distal end of an elongated channel or frame. The elongated channel is surrounded by an elongated tubular barrel-like enclosure which elongated tube and elongated channel are secured at their respective proximal most ends to the distal end of a pistol-like handle grip assembly. The handle grip assembly includes an arcuately moveable, squeezable trigger. By squeezing the trigger towards a housing portion of the handle grip assembly, a clip is advanced through the elongated channel and into the jaws of the elongated ladder like clip supply cartridge disposed through the elongated housing. The actual sequence comprises the squeezing of the trigger to close the jaws and thus crimp the clip between the jaws, then releasing the trigger to advance a new clip into location between the jaws awaiting the next squeezing of the trigger. The elongated clip supply cartridge is fed into a receiving slot or port in the proximal end of the handle grip assembly.
[0013] A rotatable enclosure barrel is rotatably supported within the handle grip assembly. The rotatable enclosure barrel is connected to the proximal end of the elongated channel.
[0014] An elongated pusher rod extends adjacent to the lower side of the elongated channel. The elongated pusher rod has a proximal end connected to a proximal bearing surrounding the enclosure barrel at the proximal end of the handle grip assembly. The pusher rod has a distalmost end with a distalmost clip engaging finger arrangement extending from one side thereof. The distalmost clip engaging finger arrangement is movable with respect to the clip loaded cartridge disposed within the elongated channel. Movement of the pusher rod thus effects clips or staples being advanced between the jaws at the distalmost end of the channel.
[0015] In the present invention, a multiplier extension arrangement is secured to the lowermost side of the channel at a proximal portion thereat, within the elongated barrel. The multiplier extension arrangement comprises a first elongated plate and a second elongated plate. The first and the second elongated plates sandwich between them an articulable link member arrangement comprising a plurality of connected link members. The link members are longitudinally and pivotably movable between the first plate and the second plate. The first and second plates are separated from one another by spacers arranged at their respective corners. The second elongated plate is secured to the underside of the channel. The first elongated plate has a diagonal cam slot arranged therethrough, running at an angle of about 4 to 10 degrees, and preferably 7 degrees with respect to the longitudinal axis of the multiplier extension arrangement. The elongated second plate has a horizontal cam slot arranged therethrough that runs parallel with respect to the longitudinal axis of the multiplier extension arrangement.
[0016] The link members of the link member arrangement comprises a proximal most first link having a first end with a diagonal guide pin extending from one side thereof. The diagonal guide pin of the first or proximal link is arranged to slide within the diagonal cam slot in the elongated first plate. The first link has a horizontal guide pin extending from the other side of the first link and into the horizontal cam slot in the elongated second plate thereadjacent. The diagonal guide pin extends from the proximal end of the first link and out through the elongated second plate in a diagonal slot therein. The first link has a second or distal end which is attached by a hinge to a second link member. The second link member has a horizontal guide pin extending from one side thereof from a midpoint of the second link member into the horizontal cam slot. The distal end of second link member is attached to a third link member by a hinge arranged therebetween. The third link member has a horizontal guide pin extending from a midpoint thereof through the horizontal cam slot on the elongated second plate. The third link member has a distalmost end which is attached by a hinge to a fourth link member. The fourth link member has a horizontal guide pin extending from a midpoint thereof into the horizontal cam slot on the elongated second plate. The horizontal guide pin on the fourth or distalmost link member is also attached to the proximalmost end of a distal multiplier arm. All horizontal guide pins extend from a midpoint of their respective links. The distal multiplier arm is longitudinally displacable between the elongated first plate and the elongated second plate. The distal end of the distal multiplier arm is attached to the proximal end of the distal push rod secured to the lowermost side of the channel of the clip applying device to which the multiplier extension arrangement is attached. The horizontal guide pin extending from the midpoint of the first or proximal most link member is secured to the distalmost end of the proximal multiplier arm. The proximal end of the proximal multiplier arm is attached to the distalmost end of the proximal push rod which extends from the handle grip assembly and which is movable pushed (and pulled) therefrom.
[0017] The proximal push rod is moved longitudinally in correspondence to the squeezing and releasing of the trigger relative to the housing of the handle grip assembly.
[0018] Longitudinal distal movement of the proximal push rod effects longitudinal distal movement of the proximal multiplier arm. The distal end of the proximal multiplier arm is attached to the first horizontal guide pin pushing that horizontal guide pin distally in the horizontal cam slot within the elongated second plate. A corresponding distal motion is also thus caused in the diagonal guide pin on the proximal end of the first link member which is disposed within the diagonal cam slot on the elongated first plate. Since the diagonal cam slot in the elongated first plate is skewed with respect to the horizontal cam slot in the elongated second plate, a rotational movement is effected in the first link about the horizontal guide pin of the first link member.
[0019] Rotational movement of the first link about its respective horizontal guide pin thus effects a rotational movement of the second link member about its respective horizontal guide pin. Rotational movement of the second link member about it horizontal guide pin in the horizontal cam slot thus effects rotational movement of the third link member about its respective horizontal guide pin within the horizontal cam slot. Rotational movement of the third link member about its horizontal guide pin effects motion of the fourth link member about its respective horizontal guide pin situated in the horizontal cam slot. The angular displacement of each of the respective link members and their cammed action within the horizontal cam slot thus effects a longitudinal displacement of the distalmost or fourth link member which, being attached to the proximal end of the distal multiplier arm, effects longitudinal distal displacement thereof. Thus the zig-zag orientation of the connected links are rotated to a straighter alignment to effect to greater overall length of those links, thus effecting the greater length of travel of the distal push rod.
[0020] Thus a first distal displacement of the proximal multiplier arm effects a greater longitudinal displacement of the distal multiplier arm (than the dital displacement of the proximal multiplier arm) which thereby effects a greater longitudinal displacement of the push rod supported under the channel and thus effects greater displacement of the staples being pushed by the distalmost end of pushrod.
[0021] In the further embodiment of the present invention, a spring may be arranged between the distalmost end of the distal multiplier arm and a portion of the channel. This spring is arranged to provide assistance to the initiation of motion of the distalmost multiplier arm and hence the pushrod, thus helping in its efficiency.
[0022] Thus what has been shown is a unique mechanism to permit a first displacement of a pushrod to be multiplied into a first displacement plus a supplemental displacement of a second pushrod downstream from the first pushrod.
[0023] Thus what has been shown is a mechanism which permits the use of a common handle trigger assembly to be utilized in conjunction with either a standard or a long legged clip which long legged clip would require longer jaws and longer displacement for entry within those jaws.
[0024] The invention thus comprises an elongated medical clip applying device having a handle grip assembly on a proximal end thereof and an elongated channel with a pair of squeezable jaws on a distal end thereof, including a push rod arrangement having a distal end and a proximal end, yhe push rod arrangement utilized for advancing a plurality of clips in a sequential manner between said jaws. The push rod including: a multiplier extender arrangement to increase the distance of travel of the distal end of the push rod arrangement a multiple of the distance of travel of the proximal end of the push rod arrangement. The multiplier extender arrangement may comprise a plurality of connected links cammed between a pair of elongated parallel plates to cam the movement of the links during movement of the proximal end of the push rod arrangement. The elongated plates may comprise a first plate and a second plate spaced parallel and apart from one another by a spacer arrangement, the elongated plates having a longitudinal axis. The first plate may have a cam slot therein arranged at an acute angle with respect to the longitudinal axis of the elongated plates. The second plate may have a horizontal cam slot therein arranged in parallel with the longitudinal axis of the elongated plates. Each of th3e links may have a horizontal guide pin extending therefrom, each of the guide pins being in cammed engagement with the horizontal cam slot. A first of the links may have a diagonal guide pin extending therefrom. The diagonal guide pine may extend into the diagonal slot in the first plate. The multiplier extender arrangement has a proximal multiplier arm in contact with the proximal pusher rod, the multiplier extender arrangement having a distal multiplier arm in contact with the distal pusher rod.
[0025] The invention also comprises a method of extending the distance of travel of the distal end of a pushed movable component on a distal end of a frame of a medical device relative to the distance of travel of an input component on a proximal end of the frame, The method may comprise the steps of: connecting a multiplier extender arrangement between the pushed movable component and the input component on the frame of the medical device; arranging a plurality of connected articulated links in the multiplier extender arrangement; pushing the plurality of connected articulated links in a distal direction a first distance by the input component as the links are in a zig-zag orientation; pushing the pushed movable component a second distance, which second distance is greater than the first distance; straightening out the zig-zag orientation of the links as they are moved distally in the extender arrangement; camming the links in an arrangement of slots in a pair of opposed elongated, parallel plates to effect an angular reorientation of the links as they are moved distally to increase their combined overall length; arranging a handle grip assembly to replace a first push rod arrangement thereon having a shorter distal advance capacity; arranging a guide pin in each of the links; and mating the pins in the slots to facilitate said camming of the links with respect to the plates.
[0026] The invention also comprises a method of extending the reachable output length of a device where the input length of the device is limited, comprising: moving a first elongated input rod longitudinally a first distance along a longitudinal axis thereof from an input component on a frame of the device and into a multiplier arrangement; moving and output rod longitudinally a second distance along a longitudinal axis thereof from the multiplier arrangement to push a movable component of the device; connecting a multiplier extender arrangement between the pushed movable component and the input component on the frame of the device; arranging a plurality of connected articulated links in the multiplier extender arrangement; pushing the plurality of connected articulated links in a distal direction a first distance by said input component as the links are in a zigzag orientation; pushing the pushed movable component a second distance, which second distance is greater than the first distance; straightening out the zig-zag orientation of the links as they are moved distally in the extender arrangement; camming the links in an arrangement of slots in a pair of opposed elongated, parallel plates to effect an angular re-orientation of the links as they are moved distally to increase their combined overall length to extend the reach of the device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The objects and advantages of the present invention will become more apparent when viewed in conjunction with the following drawings in which:
[0028] [0028]FIG. 1 is a side elevational view of a clip applying device constructed according to the principles of the present invention;
[0029] [0029]FIG. 2 is a side elevational view of an extension multiplier arrangement attached to a portion of the clip applying device shown in FIG. 1 (without its barrel housing therearound);
[0030] [0030]FIG. 3 is a perspective view of the extension multiplier device shown in FIG. 2;
[0031] [0031]FIG. 4 is a side elevational view of an extension multiplier arrangement constructed according to the principles of the present invention showing a view of the first elongated plate thereof;
[0032] [0032]FIG. 5 is a side elevational view of the extension multiplier arrangement showing the elongated second plate thereof with the links therebetween shown in phantom;
[0033] [0033]FIG. 6 is a side elevational view similar to FIG. 4 with the extension multiplier device in full extension, as seen with respect to the elongated first plate;
[0034] [0034]FIG. 7 is a view similar to FIG. 6 showing the elongated second plate when the extension multiplier device is in its extended state;
[0035] [0035]FIG. 8 is a view taken along the lines 8 - 8 of FIG. 6; and
[0036] [0036]FIG. 9 is a perspective view of one of the link members comprising a portion of the link assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] Referring now to the drawings in detail, and particularly to FIG. 1, there is shown the present invention which comprises a hand manipulable clip applying device 10 for applying medical tissue pinching clips to mammalian tissue “T”. The clip applying device 10 has a patient engaging distalmost end 12 with a pair of squeezable jaws 14 arranged on the distal end of an elongated channel or frame 16 . The elongated channel 16 is normally surrounded by an elongated tubular barrel-like enclosure 18 , which elongated tube 18 and elongated channel 16 are secured at their respective proximal most ends to the distal end of a pistol-like handle grip assembly 20 . The handle grip assembly 20 includes an arcuately moveable, squeezable trigger 22 . By squeezing the trigger 22 towards a housing portion 24 of the handle grip assembly 20 , a clip (not shown for clarity) is advanced through the elongated channel 16 and between the jaws 14 distal of an elongated ladder-like clip supply cartridge (not shown for clarity)) disposed through the elongated housing 20 . The actual sequence comprises the squeezing of the trigger 22 to close the jaws 14 and thus crimp the clip between the jaws 14 onto a tissue “T”, then releasing the trigger 22 to advance a new clip into location between the jaws awaiting the next squeezing of the trigger. The elongated clip supply cartridge is fed into a receiving slot or port 25 in the proximal end of the handle grip assembly 20 .
[0038] A rotatable enclosure barrel 26 is rotatably supported within the handle grip assembly 20 . The rotatable enclosure barrel 26 is connected to the proximal end of the elongated channel 16 .
[0039] An elongated pusher rod 30 extends adjacent to the lower side of the elongated channel 16 , as shown in FIGS. 1, 2 and 3 . The elongated pusher rod 30 has a proximal end connected to a proximal bearing within the enclosure barrel 26 at the distal end of the handle grip assembly 20 . The pusher rod 30 has a distalmost end with a distalmost clip engaging finger arrangement extending from one side thereof as shown in the recited patents incorporated herein by reference. The distalmost clip engaging finger arrangement is movable with respect to the clip loaded cartridge disposed within the elongated channel 16 . Movement of the pusher rod 30 thus effects clips or staples being advanced between the jaws 14 at the distalmost end of the channel 16 .
[0040] In the present invention, a multiplier extension arrangement 40 is secured to the lowermost side of the channel 16 as shown in FIGS. 1, 2 and 3 , at a proximal portion thereat, (normally arranged enclosed within the elongated barrel 18 , only a portion of the barrel 18 being shown in phantom, for clarity of viewing). The multiplier extension arrangement 40 , as shown more completely in FIGS. 3 - 8 , comprises a first elongated plate 42 and a second elongated plate 44 . The first and the second elongated plates 42 and 44 sandwich between them an articulable link member arrangement 46 comprising a plurality of connected link members. The link members are longitudinally and pivotably movable between the first plate 42 and the second plate 44 . The first and second plates 42 and 44 are separated from one another by spacers 48 arranged at their respective corners. The second elongated plate 44 is secured to the underside of the channel 16 as may be seen in FIG. 2. The first elongated plate 42 has a diagonal cam slot 50 arranged therethrough, as may be seen in FIGS. 3, 4, 5 , 6 and 8 , running at an angle of about 4 to 10 degrees (preferably about 7 degrees) with respect to the longitudinal axis “L” of the multiplier extension arrangement 40 , as shown in FIG. 6. The elongated second plate 44 has a horizontal cam slot 52 arranged therethrough that runs parallel with respect to the longitudinal axis “L” of the multiplier extension arrangement 40 , as may be seen in FIGS. 4, 5, 7 and 8 .
[0041] The link members of the link member arrangement 46 comprises a proximal most first link 54 having a first end 56 with a diagonal guide pin 58 extending from one side thereof, as is shown in FIGS. 4, 5 and 6 . The link arrangement 46 is shown in a zig-zag configuration in FIGS. 4 and 5, that link arrangement 46 straightening out into a generally straight orientation, as indicated in FIGS. 6 and 7. (A typical link 99 is shown in FIG. 9, which either comprises the link member or one “side” of the link member of a parallel link member arrangement). The diagonal guide pin 58 of the first or proximal link 54 is arranged to slide within the diagonal cam slot 50 in the elongated first plate 42 . The first link 54 has a horizontal guide pin 60 extending from the other side of the first link 54 and into the horizontal cam slot 52 in the elongated second plate 44 thereadjacent. The horizontal guide pin 60 extends from the proximal end of the first link 54 and out through the elongated second plate 44 . The first link 54 has a second or distal end 62 which is attached by a hinge 64 to a second link member 66 . The second link member 66 has a horizontal guide pin 68 extending from one side thereof from a midpoint of the second link member 66 through the elongated second plate 44 . The distal end of second link member 66 is attached to a third link 70 member by a hinge 72 arranged therebetween. The third link member 70 has a horizontal guide pin 74 extending from a midpoint thereof through the horizontal cam slot 52 on the elongated second plate 44 . The third link member 70 has a distalmost end 76 which is attached by a hinge 78 to a fourth link member 80 . The fourth link member 80 has a horizontal guide pin 82 extending from a midpoint thereof into the horizontal cam slot 52 on the elongated second plate 44 , as shown in FIGS. 4, 5, 6 , 7 and 8 . The horizontal guide pin 82 on the fourth or distalmost link member 80 is also attached to the proximalmost end 84 of a distal multiplier arm 86 . The distal multiplier arm 86 is longitudinally displacable between the elongated first plate 42 and the elongated second plate 44 , as indicated by the arrow “A” in FIG. 4. The distal end of the distal multiplier arm 86 is attached to the proximal end 88 of the distal push rod 90 secured to the lowermost side of the channel 16 of the clip applying device 10 to which the multiplier extension arrangement 40 is attached, as shown in FIG. 3. The horizontal guide pin 60 extending from the midpoint of the first or proximalmost link member 54 is secured to the distalmost end 92 of the proximal multiplier arm 94 . The proximal end 96 of the proximal multiplier arm 94 is attached to the distalmost end 98 of the proximal push rod 100 which extends from the handle grip assembly 20 , as shown in FIGS. 3, 4 and 5 .
[0042] The proximal push rod 100 is moved longitudinally in correspondence to the squeezing and releasing of the trigger 22 relative to the housing 24 of the handle grip assembly 20 .
[0043] Longitudinal distal movement of the proximal push rod 100 effects longitudinal distal movement of the proximal multiplier arm 94 . The distal end 92 of the proximal multiplier arm 94 is attached to the first horizontal guide pin 60 pushing that horizontal guide pin 60 distally in the horizontal cam slot 52 within the elongated second plate 44 . A corresponding distal motion is also thus caused in the horizontal guide pin 60 on the proximal end of the first link member 54 which is disposed within the horizontal cam slot 52 on the elongated second plate 44 . Since the diagonal cam slot 50 in the elongated first plate 42 is skewed with respect to the horizontal cam slot 52 in the elongated second plate 44 , a counterwise (as seen in FIG. 4) rotational movement is effected in the first link 54 about the horizontal guide pin 60 of the first link member 54 .
[0044] Rotational movement of the first link 54 about its respective horizontal guide pin 60 thus effects a rotational movement of the second link member 66 about its respective horizontal guide pin 68 . Rotational movement of the second link member 66 about it horizontal guide pin 68 in the horizontal cam slot 52 thus effects rotational movement of the third link 70 member about its respective horizontal guide pin 74 within the horizontal cam slot 52 . Rotational movement of the third link member 70 about its horizontal guide pin 74 effects motion of the fourth link member 80 about its respective horizontal guide pin 82 situated in the horizontal cam slot 52 . The angular displacement of each of the respective link members 54 , 66 , 70 and 80 and their cammed action within the horizontal cam slot 52 thus effects a longitudinal displacement of the distalmost or fourth link member 80 which, being attached to the proximal end 84 of the distal multiplier arm 86 , effects longitudinal distal displacement thereof.
[0045] Thus a first distal displacement of the proximal multiplier arm 94 effects a greater longitudinal displacement of the distal multiplier arm 86 (than the distal displacement of the proximal multiplier arm) which thereby effects a greater longitudinal displacement of the push rod 90 supported under the channel 16 , and thus effects greater displacement of the staples being pushed by the distalmost end of pushrod 90 .
[0046] In the further embodiment of the present invention, a spring 102 may be arranged between the distalmost end of the distal multiplier arm 86 and a downstream portion of the channel 16 . This spring 102 is arranged to provide assistance to the initiation of motion of the distalmost multiplier arm 86 and hence the pushrod 90 , thus helping in its efficiency.
[0047] Thus what has been shown is a unique mechanism to permit a first displacement of a proximal pushrod 100 to be multiplied into a first displacement plus a supplemental displacement of a second pushrod 90 downstream from the first pushrod 100 .
[0048] Thus what has been shown is a mechanism which permits the use of a common handle trigger assembly to be utilized in conjunction with either a standard or a long legged clip which long legged clip would require longer jaws and longer displacement for entry within those jaws.
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An elongated medical clip applying device having a handle grip assembly on a proximal end thereof and an elongated channel with a pair of squeezable jaws on a distal end thereof. A push rod arrangement is included having a distal end and a proximal end. The push rod arrangement is utilized for advancing a plurality of clips in a sequential manner between the jaws. The push rod includes a multiplier extender arrangement to increase the distance of travel of the distal end of the push rod arrangement a multiple of the distance of travel of the proximal or input end of the push rod arrangement.
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FIELD OF INVENTION
The present invention relates to the field of mobile phone communications.
BACKGROUND OF THE INVENTION
Mobile phone use throughout the world has become widespread and is expected to grow as the costs of the devices and cellular network access decreases. With the advent of newer and more compact components, mobile phones have evolved from heavy, brick-like devices that can only send or receive a call, to compact and lightweight devices that typically include, in addition to the phone hardware itself, a video screen, camera, substantial memory, powerful computer processors, high-volume speakers, and data ports. These devices have become more than just phones, and can be used to take still pictures or video, send or receive email, Short Message Service (SMS) and Instant Message (IM) communications, store and play music, watch video, and browse the Internet.
As mobile phones have incorporated these capabilities, the ability for a user to manage and access them has become more complex, typically involving multiple buttons, wheel or trackwheels, menus, submenus, and hotkeys. For example, instead of a simple numeric keypad, many mobile phones now incorporate full keyboards to type out email and SMS messages. Increasing the number of buttons on a phone, however, dictates that the size of the mobile phone not go beyond a certain limit, as the buttons would become too small for effective use. In an effort to overcome this inherent limitation, mobile phones have been developed to fold out or slide out to temporarily increase its size for full keyboard use. Other mobile phones incorporate software that allows a single button to potentially input different letters, thereby decreasing the number of buttons required for typing out email or SMS messages.
Though most efforts are being made to add functionality to mobile phones, (inherently making them more complex) some have attempted to simplify their input systems. For example, U.S. Pat. No. 6,035,217 describes a mobile phone with a single button. The button can be used to pick up an incoming call, hang up, or turn the device on or off. When the user desires to place a call, they depress the button, which automatically calls a predetermined phone number to connect the user to a service provider that connects the user to the desired phone number. U.S. Pat. No. 6,917,802 describes a mobile phone without any buttons besides an on/off switch. In place of buttons, voice commands are used to initiate, pick up, or hang up a call. When the command is made to initiate a call, the mobile phone calls a predetermined phone number to connect to a voice dialing server. The user then recites a keyword or a phone number to be dialed, which the voice server automatically dials and conferences in the user's mobile phone.
Simplified mobile phones as previously described offer several advantages over the hardware-heavy mobile phones typically in use today. Simplified mobile phones can be engineered to be much more compact than a mobile phone, and their simplicity in function better allows for the design of extensive battery life for the device. Simplified mobile phones also make more likely to possibility of designing a device with a low manufacturing cost, maybe even to the extent that it would be economically feasible to provide a mobile phone service whereby mobile phones can be recycled or discarded.
Nevertheless, the simplified phones described are not without their problems. A phone that has even a single button to initiate or pick up calls can require that the mobile phone user find the button to depress it, which could be problematic during certain situations, such as if the user is driving an automobile. Likewise, the use of voice dialing servers are inherently prone to error in recognizing voice commands. Background noise, language accents, and noisy mobile phone signals can thwart the server's ability to recognize what number the user desires to dial. The specific software hierarchy of the server also makes it inherently inflexible and thereby a potential source of frustration to a mobile phone user. Most notably, a voice dialing server can only serve a single purpose—to dial phone numbers on command. A voice dialing server cannot be effectively used to send or receive the text messages that are commonly exchanged between mobile phone users (e.g., email, SMS, IM).
It is therefore preferred to provide a simplified, buttonless mobile phone system that does not rely on voice dialing servers and that allows the transmission and receipt of text communications.
As a further point, many of today's mobile phones operate on the Global System for Mobile Communication (GSM) network. Mobile phones that operate on this network require a Subscriber Identity Module (SIM card), which is a portable memory chip that includes, among other things, the registration information used to connect a mobile phone to a specific mobile phone service provider. Mobile phone service providers, however, typically provide local call service within a specific geographic area. If a mobile phone user goes beyond this area, they incur “roaming charges” when making or receiving a call. These roaming charges are generally much more expensive than local mobile phone service charges.
To overcome this problem, individual SIM cards for a specific region have been made available for purchase by mobile phone users. Upon entering an area where the mobile phone user could incur roaming charges, the mobile phone user can open their phone and replace the SIM card with one that is local to the service area they have entered. In this way, the mobile phone user can avoid roaming charges. This method, however, is problematic in that it requires the mobile phone user to have a certain degree of sophistication in being able to replace a SIM card. It also requires that the mobile phone user identify and buy a SIM card that is compatible with their specific phone.
It is therefore preferred to provide a simplified, buttonless mobile phone system that more easily switches out SIM cards so that a mobile phone user can use a mobile phone service without incurring roaming charges.
SUMMARY OF THE INVENTION
In one aspect, a system for communicating through a mobile phone includes a buttonless mobile phone with a power supply capable of enabling or disabling power to the buttonless mobile phone; and memory to store a phone number directed to a remote station; and a remote station to receive a call from the mobile phone, the remote station allowing a human operator access to a database describing at least one contact unique to the user; wherein the operator uses the database of contact information to facilitate a communication from the user to the contact described in the database.
In another aspect, a system includes a buttonless mobile phone without a video screen, comprising a power supply with means for enabling or disabling the power supply; a remote station comprising a human operator with access to at least one text communication account of a user of the mobile phone; and the human operator reading to the user of the mobile phone at least some of the content of a text communication from the text communication account.
In yet another aspect, a communication device includes a buttonless mobile phone without a video screen; a power supply for enabling or disabling power to the buttonless mobile phone; and a headset housing.
In another aspect, a mobile phone telecommunications system includes a plurality of mobile phones, comprising a first mobile phone containing a SIM card that is compatible with a first mobile phone network and with memory storing a phone number directed to a remote station; a second mobile phone containing a SIM card that is compatible with a second mobile phone network and with memory storing a phone number directed to a remote station; at least one remote station comprising a database describing at least one contact unique to a user of the mobile phone telecommunications system. In one embodiment, the user causes the first mobile phone to call the remote station and have the remote station facilitate a communication from the user to a contact described within the database; and at a later time, the user causes the second mobile phone to call the remote station and have the remote station facilitate a communication from the user to a contact described within the database.
In yet another aspect, a mobile phone telecommunications system includes a plurality of mobile phones with a first mobile phone containing a SIM card that is compatible with a first mobile phone network and with memory storing a phone number directed to a remote station; a second mobile phone containing a SIM card that is compatible with a second mobile phone network and with memory storing a phone number directed to a remote station; at least one remote station comprising a human operator with access to at least one text communication account of a user of the mobile phone. The user causes the first mobile phone to call the remote station and have the human operator read to the user of the mobile phone at least some of the content of a text communication from the text communication account; and at a later time, the user causes the second mobile phone to call the remote station and have the human operator read to the user of the mobile phone at least some of the content of a text communication from the text communication account.
The system provides a simplified, buttonless mobile phone system that does not rely solely on voice dialing servers and that also allows the transmission and receipt of non-oral communications. This is primarily accomplished by using a human operator located at a remote station who has access to the contact information of a particular mobile phone user, potentially including any email, SMS, or IM accounts. In this manner, the human operator can, not only connect the mobile phone user to the desired number, but also, orally communicate to the mobile phone user and email, SMS, or IM messages received, and communicate email, SMS, or IM messages that the mobile phone user desires to be sent. A human operator can also theoretically offer the mobile phone user a variety of personal services, such as finding and buying tickets to a musical event, looking up information on the Internet, arranging for airline tickets, etc. . . . Indeed, the limit of the human operator to provide personal services to the mobile phone user will be generally limited only by the information and authorization that a mobile phone user is willing to provide to the mobile phone system described herein.
In one embodiment, the system comprises a system for communicating through a mobile phone, the system comprising: (1) a buttonless mobile phone with a power supply and means for enabling or disabling the power supply (e.g., a manual button, a heat sensor, a capacitance switch, etc. . . . ) and memory storing a preprogrammed phone number directed to a remote station; (2) a user causing the mobile phone to call the remote station, the remote station comprising a human operator and a database describing at least one contact unique to the user; and (3) the operator using the database of contact information to direct a communication from the user to a contact described within the database.
In another embodiment, the system comprises a system for receiving an email communication on a buttonless mobile phone without a video screen, the system comprising: (1) a buttonless mobile phone without a video screen and a power supply with means for enabling or disabling the power supply; (2) a remote station comprising a human operator with access to at least one email, SMS, or IM account of a user of the mobile phone; and (3) the human operator using the mobile phone to read to the user at least some of the content of an email, SMS, or IM message from the respective user account.
By simplifying the mobile phone input system, and by removing the need for a video screen to compose or read non-oral messages, the present invention enables one skilled in the art to design highly compact mobile phones with optimized shapes. For example, all the components necessary to operate a mobile phone with the present invention can be built into a housing shaped as a headset, much like the bluetooth headsets available on the market today. Unlike the bluetooth headsets, however, the headsets of the present invention will not depend on a separate mobile phone device with transmission and reception capabilities. Alternatively, a mobile phone to be used with the present invention can be shaped as a pendant to be worn around the neck, or as a brooch designed to be pinned to the collar of a shirt. Accordingly, one embodiment of the present invention comprises a buttonless mobile phone without a video screen, the phone comprising a power supply with means for enabling or disabling the power supply; and a housing in the shape of a headset. The mobile phone may also be designed such that it can be manually transformed by the user from a phone that can be worn as a headset to a phone that can be worn as a pendant or brooch, and vice-versa.
It is also an object of the present invention to provide a simplified, buttonless mobile phone system that more easily switches out SIM cards so that a mobile phone user can use a mobile phone service without incurring roaming charges. This is primarily accomplished by creating a system where, when the mobile phone user enters a geographic area where their first mobile phone could incur roaming charges, the mobile phone user obtains a second mobile phone with a SIM card with a registration for a local mobile phone service provider. By way of example, the mobile phone user can obtain the second mobile phone from a dispenser at an airport or train station, with the first mobile phone being thrown away or segregated for recycling. Since the mobile phone user's contact information is located at a remote station, the second mobile phone need only have in its memory a phone number to connect to a remote station. Upon contacting the remote station, the user can have the remote station facilitate communications through the second mobile phone without incurring roaming charges. This is a particular useful system where low-cost, compact, and simplified mobile cell phones are used, including those described within this disclosure.
One embodiment of the present invention accordingly comprises a mobile phone telecommunications system, the system comprising: (1) a plurality of mobile phones with a first mobile phone containing a SIM card that is compatible with a first mobile phone network and with memory storing a preprogrammed phone number directed to a remote station; (2) a second mobile phone containing a SIM card that is compatible with a second mobile phone network and with memory storing a preprogrammed phone number directed to a remote station; (3) at least one remote station comprising a database describing at least one contact unique to a user of the mobile phone telecommunications system; (4) the user causing the first mobile phone to call the remote station and have the remote station telephonically connect the user to a contact described within the database; and, (5) at a later time, the user causing the second mobile phone to call the remote station and have the remote station telephonically connect the user to a contact described within the database.
In another embodiment of the present invention, the mobile phone telecommunications system comprises (1) a plurality of mobile phones with a first mobile phone containing a SIM card that is compatible with a first mobile phone network and with memory storing a preprogrammed phone number directed to a remote station; (2) a second mobile phone containing a SIM card that is compatible with a second mobile phone network and with memory storing a preprogrammed phone number directed to a remote station; (3) a remote station comprising a human operator with access to at least one email, SMS, or IM account of a user of the mobile phone; and (3) the human operator using the first mobile phone to read to the user at least some of the content of an email, SMS, or IM message from the respective user account; and, (5) at a later time, the human operator using the second mobile phone to read to the user at least some of the content of an email, SMS, or IM message from the respective user account.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram of a basic design of a mobile phone to be used in the systems of the present invention.
FIG. 2 is a diagram of various headset phones that are the subject of the present invention.
FIG. 3 is a flowchart depicting a process for initiating a phone call using system of the present invention.
FIG. 4 is a flowchart depicting a process for sending a textual communication using system of the present invention.
FIG. 5 is a flowchart depicting a mobile telecommunications system for avoiding roaming charges using the system of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 reflects an embodiment of the present invention in its simplest form, as well as other potential embodiment. The simplest embodiment comprises the basic hardware necessary to the operation of a mobile phone 100 , including a power source 101 , transceiver 102 , antennae 103 , microphone 104 , speaker 105 , housing 106 , and, in some embodiments, means for switching the power state of the mobile phone, such as a button or toggle switch 107 .
Unlike most mobile phones, however, the mobile phones of the present invention are generally designed such that they have no buttons or touch screens other than what could be used to switch the power state of the device from on to off or vice-versa. Instead, oral commands and heat or capacitance sensors are used command the functionality of the phone, such as connecting to a desired telephone number or picking up an incoming call. For example, the mobile phone could be commanded to pick up an incoming call through monitoring of voice commands through the speaker 105 , followed by a voice command being spoken. In another embodiment, a heat or capacitance sensor can be used to sense a touch on the housing 106 of the device. The touch, for example, could command the phone to pick up or hang up a call. The timing or pattern of the touch can also be used to distinguish between commands. For example, a long period of touching could be used as a command to change the power state of the device, while a shorter period of touching could be used as a command to pick up an incoming call. Likewise, a touch that ascends or descends along the vertical access of the device could be used as a command to respectively increase or decrease the volume of the speaker 105 .
To be used with the systems of the present invention, the mobile phones also comprise a memory module 108 . The memory module can be extraordinarily small, sufficient to store just a single telephone number, or it can be designed to have vast amounts of memory to allow for the storing of media files, such as digital music files, digital photographs, and digital movies. At the least, the memory module must be large enough to store data that enables the phone to connect to a remote station.
FIG. 2 reflects additional embodiments of the present invention. The mobile phones 200 to be used with the present invention can comprise a video screen 201 , though it is preferred that the mobile phones be designed to not contain such a screen to take full advantage of minimal power requirements. In another embodiment, the mobile phone can also comprise a hardwire or wireless link 203 to a separate device 204 that comprises additional hardware, such as a video screen 201 , keyboard 205 , digital camera 206 , or music player 207 . The hardwire link 203 in particular can be one such that the separate device 204 , or a number of separate devices, can be stacked onto the phone 200 so as to create a single hardware unit with multiple capabilities, such as, for example a phone with a video screen, or a phone with a keyboard or music player. The mobile phone 200 or the separate device 204 could also comprise a Global Position System (GPS) transceiver 208 or similar geolocation device.
Since the mobile phone 200 could only require simple operational hardware, the phone 200 can be designed to be highly compact and take on conformations that make it easy to carry. For example, the mobile phone 200 could take the shape of a bracelet, a watch, a pendant, sunglasses, or a necklace, with the housing 209 shaped appropriately. Preferably, the mobile phone 200 and the housing 209 are shaped as a brooch or pin 210 to be attached to the collar of a shirt or jacket. In this embodiment, the microphone 211 and speaker 212 could be fixed into the housing of the device 209 . In another embodiment of the brooch device 210 , one or both of the microphone 211 and speaker 212 could be pulled from the housing of the device 209 , connected by, for example, a retractable wire 213 . The mobile phone 200 and housing 209 of the present invention could also be shaped as a headset 214 . In this embodiment, the headset would be worn on the head or ear of the user, with the microphone 211 placed near the tip of the boom 215 of the headset 214 , and the speaker 212 placed nearer to the ear of the user. In a related embodiment, the headset can be manually transformed by the user into a phone that can be worn as a pendant or brooch, and vice-versa. In such an embodiment, upon transforming the phone from headset mode to pendant or brooch mode, the speaker 212 may be configured to operate as a speakerphone when the phone is in pendant or brooch mode. Other components, such as the microphone 211 can likewise be configured to operate as needed in a certain mode. Some embodiments of the present invention require a remote station, which generally comprises a human operator and a list of contact information unique to the user, such as a list of telephone numbers of colleagues previously provided by a mobile phone user. The remote station can also be configured to have access to the email, SMS, or IM accounts of the mobile phone user. The remote station can also comprise an automated voice input device that can receive oral commands and be programmed to take specific actions in response to those commands. The voice input could thus be used to minimize or eliminate any need to have a human operator control the function of the remote station at every level.
The remote station generally serves as a central repository of the user's contact information and can be used to facilitate the making of communications between the user of a mobile phone and another entity. For example, when a mobile phone user desires to telephonically connect to another individual, the user would command the mobile phone to connect with the remote station. Upon connection, the remote station receives instructions to telephonically connect the mobile phone user to a specific individual, most likely one who is listed in a database of unique contact information that the remote station has access to. If the specific individual to be called is not listed in the database, the mobile phone user can verbally communicate to the remote station the specific number to be called, with the remote station taking the appropriate action.
In the same manner, the remote station can be used by the mobile phone user to send an email, SMS, IM message, or other textual message. In this embodiment, the mobile phone user would command the phone to connect with the remote station. The remote station would then receive oral instructions to send a textual message to a specific individual identified in the database of unique contact information, with the textual message being dictated orally by the mobile phone user. Again, if the specific individual to be contacted is not listed in the database, the mobile phone user can verbally communicate to the remote station the specific contact information to be used, with the remote station taking the appropriate action.
FIG. 3 is a flowchart reflecting an embodiment of the present invention as it is used to initiate and terminate a phone call. In this embodiment, the mobile phone user touches the mobile phone 300 , thereby commanding it to connect to a remote station 301 . The mobile phone user then communicates to the remote station that they desire to place a call to a target identified in a database of contact information unique to the user 302 . The remote station telephonically connects to the target 303 , bridges the communications between the mobile phone user and the target 304 , and then the remote station terminates its connection to both the mobile phone user and the target 305 . The call between the mobile phone user and the target takes place 306 , with the call being terminated either through the target terminating the call or the mobile phone user touching the mobile phone to give the appropriate termination command 307 .
There are many variations of the embodiment reflected in FIG. 3 . For example, instead of having the remote station telephonically connect to the target, the remote station can transmit to the mobile phone the contact information for the target, which is then stored in a memory module within the phone. The mobile phone could then be used to contact the target directly, obviating the need for the remote station to make the initial call to the target. Likewise, the mobile phone user could dictate the number of the call to be made instead of having the remote station access the database of unique contact information. The mobile phone user can also direct the remote station to stay on a specific call to, for example, input keytone commands during a call that requires such commands, such as when a customer service entity is called that requires the person calling to input their account numbers with the entity. Voice input devices could also be used with this system to minimize the need for a human operator at the remote station to make all the steps necessary to having the mobile phone user make a call to a target.
In another embodiment, the remote station can continue to stay on the call between the mobile phone user and their outgoing call target to ensure a reliable connection. In the event that the mobile phone user is unintentionally disconnected from the call, the presence of the remote station can ensure the continuation of the call with the outgoing call target, put the target on hold, call the mobile phone user again until connection is established, and then conference in the mobile phone user with the outgoing call target. The same method can be employed if the outgoing call target is unintentionally disconnected. By using this embodiment, both the outgoing call target and mobile phone user can avoid having to redial the other's phone number to reestablish connection. Reconnection is instead facilitated through the remote station and the call can be terminated only upon voice command.
FIG. 4 is a flowchart reflecting an embodiment of the present invention as it is used to send a textual message. In this embodiment, the mobile phone user touches the mobile phone 400 , thereby commanding it to connect to a remote station 401 . The mobile phone user then communicates to the remote station that they desire to make a textual message to a specific target 402 , such as one identified in a database of contact information unique to the user. The mobile phone user dictates the textual message to be sent 403 and the remote station transforms that dictation into a textual message 404 . The remote station then transmits the textual message to the target 405 .
Embodiments of the present invention can also be used to receive phone calls or textual messages. For example, when a call is made to the mobile phone user, the call is can be placed directly to the phone number of the mobile phone user. The user would then pick up the call by touching the mobile phone to give the command to pick up the incoming call. In another embodiment, an incoming call to a mobile phone user can be picked up by a human operator. If the phone number of the incoming caller is listed among mobile phone user's unique contact information, the human operator can readily identify the incoming caller, put them on hold, contact the mobile phone user and announce who is calling, and if desired, connect the incoming caller with the mobile phone user. In the event that the incoming caller's phone number is not among the mobile phone user's unique contact information, the human operator optionally can set up an address for the incoming caller in the user's unique contact information and ask the incoming caller for their relevant information.
When a textual message is made to mobile phone user, the remote station can detect the making of this textual message and call the mobile phone user to notify them of the incoming message. At least some parts of the textual message is then orally communicated to the mobile phone user, such as the address of the sender, the time, or the specific message that is to be communicated. Preferably, the remote station contains a filter or protocol to minimize the chance that an incoming textual message is a “spam” or irrelevant textual message. In an alternative embodiment, the remote station can remain passive to the receipt of textual messages. When the mobile phone user desires to check the status of received textual messages, the mobile phone user contacts the remote station which then notifies the mobile phone user whether textual messages were received or not.
The present invention can also be designed to have functionality equivalent to or even beyond the functionality of most mobile phones. For example, an embodiment of the present invention could incorporate a voicemail feature. When voicemail message is received for a particular mobile phone user, the remote station can either call the mobile phone to notify the user of the existence of a voicemail message, or more preferably, the mobile phone would be notified of the existence of a voicemail message upon contacting the remote station. Management of the voice mailbox (e.g., storing, deleting, and playing messages) could be controlled through verbal commands given by the user to a voice input device, or it could be controlled by having the mobile phone user give instructions to a human operator at the remote station.
Another embodiment of the present invention could also incorporate an ability to customize settings for the mobile phone, such as ringer or volume settings. For example, the mobile phone user could contact the remote station to communicate specific settings to be applied to the phone. Some of those settings, such as volume and ringer settings could then be communicated back to the mobile phone from the remote station to change the settings of the mobile phone. Alternatively, the mobile phone user could access an Internet site to apply specific settings to the mobile phone. Those settings could then be communicated back to the mobile phone to change its settings.
An embodiment of the present invention could further incorporate the ability to play digital music files or experience other media files, such as digital photographs and video. To play a digital music file, the present invention could incorporate a large memory module in the mobile phone itself. When the mobile phone user desires to listen to a particular file, they can contact the remote station to identify the music file to be played (which can either be stored on a database that the remote station has access to, or which can be downloaded remotely). The remote station can transmit or stream the music file to the memory module in the phone, which can then play the music file and output sound through the speaker of the device. In the same manner, embodiments of the present invention can be used to experience other media files, so long as the mobile phone system incorporates the appropriate output devices.
Perhaps most advantageously, embodiments of the present invention can incorporate a human operator at a remote station, which provides the mobile phone communication system with a degree of flexibility unrivaled by the functionality provided by prior mobile phone communication systems. Using the present invention, the human operator can be used by the mobile phone user as a personal assistant to perform such tasks as browsing the Internet to identify an address or answer a particular question, order goods or services, or give navigational directions. Generally speaking, the present invention can provide expansive functionality through the use of a human operator, limited only by the amount of information and authorization the mobile phone user provides to the human operator.
Some embodiments of the present invention also provide advantages through enabling the design of a mobile cell phone that has minimal hardware components, and thus, a relatively low cost of manufacture. Mobile phones embodying the present invention could thus be used in a system where mobile phones are recycled or even discarded, especially given that all personal information typically loaded onto a mobile cell phone is accessible through a remote station. After the user of the system discards a mobile phone, they only need to obtain another mobile phone that can contact a remote station and thus obtain access to the mobile phone user's contacts and email, SMS, or IM accounts.
It is preferred that, when a user obtains a new mobile phone to be used with the present invention, the user immediately contacts the remote station to verify that the particular user is associated with a particular mobile phone. This can be done, for example, through the use of a security code specifically assigned to the mobile phone user. When the remote station assigns a particular mobile phone to a particular user, it is also preferred that the settings or other data stored on the previous mobile phone get transferred to the new mobile phone, thus providing a seamless switch for the mobile phone user.
In one embodiment of the present invention, a mobile phone telecommunications system can be designed to circumvent roaming charges. The mobile phone system accomplishes this by providing the mobile phone user with access to multiple mobile phones, with each incorporating a SIM card that contains registration information for a particular geographical area. Each phone will also have a preprogrammed phone number directed to a remote station. Upon entering or planning to enter a particular geographic area, the mobile phone user need only use the appropriate mobile phone to contact a remote station. There could be one remote station or multiple remote stations. The contacted remote station would need only have access to a database containing contact information unique to the mobile phone user.
FIG. 5 is a flowchart reflecting an embodiment of the present invention for avoiding roaming charges. In the first step, the mobile phone user uses a first mobile phone in a geographic area for a first mobile phone network 500 . The first mobile phone contains a SIM card that is compatible with the first mobile phone network and with memory storing a preprogrammed phone number directed to a remote station. In this manner, only local charges will be applied to the user's mobile phone use. Eventually, the user moves to a geographic area containing a second mobile phone network 501 . Rather than use the first mobile phone in the second network and incur roaming charges, the mobile phone user obtains a second mobile phone 501 . The second mobile phone contains a SIM card that is compatible with the second mobile phone network and with memory storing a preprogrammed phone number directed to a remote station. The mobile phone user then uses the second mobile phone to contact a remote station 502 . The mobile phone user can then use the contacted remote station to make communications with the second mobile phone 503 , through which the user can avoid incurring roaming charges.
In this embodiment, it is preferred that, when the mobile phone user first uses the second phone to contact a remote station 502 , the remote station register the second mobile phone to the mobile phone user. This can be accomplished through the use of a security procedure to verify the mobile phone user's identity, such as a passcode or security question. Upon registration, the remote station can transmit the mobile phone user's settings for the first mobile phone to the second mobile phone.
To configure the mobile phone user to receive phone calls with the second mobile phone, the remote station can register the telephone number of the second mobile phone to the mobile phone user. To avoid roaming charges for incoming calls, the remote station can automatically forward calls targeted to the phone number of the first mobile phone to the phone number of the second mobile phone. The remote station could also pick up an incoming call targeted at the first mobile phone, call the mobile phone user at the second mobile phone, and conference the calls. Alternatively, the remote station can transmit settings to the second mobile phone sufficient to change the telephone number of the second mobile phone to the telephone number of the first mobile phone.
Embodiments of the present invention could also include a dispenser for dispensing mobile phones to be used with the present invention. The dispenser would contain mobile phones with SIM cards that are compatible with a mobile phone network in the geographic area where the dispenser is located. These dispensers would preferably be located at points of transit, such as airports, train stations, and bus stations. Accordingly, when a user of the mobile phone system arrives at a point of transit and enters a geographic area where the first mobile phone could incur roaming charges, the mobile phone user merely accesses a dispenser and obtains a second mobile phone with a SIM card that is compatible with a local mobile phone network. The first mobile phone can be recycled at the dispenser area, kept, or even discarded.
Alternatively in another embodiment, roaming charges can also be avoided without having the mobile phone recycled or discarded. This can be accomplished by incorporating a nonvolatile memory module in the phone that can store the settings of any SIM card inserted into the phone or that can be downloaded from the remote station. When a mobile phone user enters a geographic location requiring a new SIM card for local service, the user can avoid roaming charges in the traditional manner by inserting an appropriate SIM card. However, when the user enters the same location again and needs to switch a SIM card, the user can instead instruct the remote station to cause the mobile phone to use the registration information of the SIM card that was previously inserted into the phone to obtain local service. In this manner, the user need not open the phone to insert another SIM card. Alternatively, when the user enters a geographic area requiring a new SIM for local service, the user can contact the remote station to download into the phone SIM registration information for that particular geographic area.
It will be appreciated by those skilled in the art having the benefit of this disclosure that numerous variations from the foregoing embodiments will be possible without departing from the inventive concept described herein. Accordingly, it is the claims set forth below, and not merely the foregoing illustrations, which are intended to define the exclusive rights of the invention.
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Systems and methods for communicating through a mobile phone are disclosed with a buttonless mobile phone including a power supply with means for capable of enabling or disabling the a power supply; and memory to store a phone number directed to a remote station; a remote station to receive a call from a user causing the mobile phone to call the remote station, the remote station comprising allowing a human operator and access to a database describing at least one contact unique to the user; and wherein the human operator uses the database of contact information to facilitate a communication from the user to the contact in the database.
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PRIORITY CLAIM TO RELATED APPLICATIONS
[0001] The present application claims priority benefit under 35 U.S.C. §120 to, and is a continuation of U.S. patent application Ser. No. 11/415,600, filed on May 2, 2006, entitled “Resposable Pulse Oximetry Sensor,” now U.S. Pat. No. 8,000,761, which is a continuation of U.S. patent application Ser. No. 10/741,777, filed on Dec. 19, 2003, entitled “Resposable Pulse Oximetry Sensor,” now U.S. Pat. No. 7,039,449, which is a continuation of U.S. patent application Ser. No. 10/128,721, filed on Apr. 23, 2002, entitled “Resposable Pulse Oximetry Sensor,” now U.S. Pat. No. 6,725,075, which is a continuation U.S. patent application Ser. No. 09/456,666, filed Dec. 12, 1999, entitled “Resposable Pulse Oximetry Sensor,” now U.S. Patent No. 6 , 377 , 829 . The present application incorporates the foregoing disclosures herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates in general to sensors for measuring oxygen content in the blood, and, in particular, relates to resposable (reusable/disposable) sensors having an information element contained therein.
BACKGROUND
[0003] Early detection of low blood oxygen is critical in a wide variety of medical applications. For example, when a patient receives an insufficient supply of oxygen in critical care and surgical applications, brain damage and death can result in just a matter of minutes. Because of this danger, the medical industry developed oximetry, a study and measurement of the oxygen status of blood. One particular type of oximetry, pulse oximetry, is a widely accepted noninvasive procedure for measuring the oxygen saturation level of arterial blood, an indicator of the oxygen status of the blood. A pulse oximeter relies on a sensor attached to a patient in order to measure the blood oxygen saturation.
[0004] Conventionally, a pulse oximeter sensor has a red emitter, an infrared emitter, and a photodiode detector. The sensor is typically attached to a patient's finger, earlobe, or foot. For a finger, the sensor is configured so that the emitters project light through the outer tissue of the finger and into the blood vessels and capillaries contained inside. The photodiode is positioned at the opposite side of the finger to detect the emitted light as it emerges from the outer tissues of the finger. The photodiode generates a signal based on the emitted light and relays that signal to an oximeter. The oximeter determines blood oxygen saturation by computing the differential absorption by the arterial blood of the two wavelengths (red and infrared) emitted by the sensor.
[0005] Conventional sensors are either disposable or reusable. A disposable sensor is typically attached to the patient with an adhesive wrap, providing a secure contact between the patient's skin and the sensor components. A reusable sensor is typically a clip that is easily attached and removed, or reusable circuitry that employs a disposable attachment mechanism, such as an adhesive tape or bandage.
[0006] The disposable sensor has the advantage of superior performance due to conformance of the sensor to the skin and the rejection of ambient light. However, repeated removal and reattachment of the adhesive tape results in deterioration of the adhesive properties and tearing of the tape. Further, the tape eventually becomes soiled and is a potential source of cross-patient contamination. The disposable sensor must then be thrown away, wasting the long-lived emitters, photodiode and related circuitry.
[0007] On the other hand, the clip-type reusable sensor has the advantage of superior cost savings in that the reusable pulse sensor does not waste the long-lived and expensive sensor circuitry. However, as mentioned above, the clip-type reusable sensor does not conform as easily to differing patient skin shape, resulting in diminished sensitivity and increased ambient light.
[0008] Similar to the clip-type reusable sensor, the circuit-type reusable sensor advantageously does not waste the sensor circuitry. On the other hand, the circuit-type reusable sensor fails to provide quality control over the attachment mechanism. Much like the disposable sensors, the attachment mechanism for the circuit-type reusable sensor may become soiled or damaged, thereby leading to cross-patient contamination or improper attachment. Moreover, because the reusable circuit is severable from the attachment mechanism, operators are free to use attachment mechanisms that are either unsafe or improper with regard to a particular type of reusable circuitry.
[0009] Based on the foregoing, significant and costly drawbacks exist in conventional disposable and reusable oximetry sensors. Thus, a need exists for an oximetry sensor that incorporates the advantages found in the disposable and reusable sensors, without the respective disadvantages.
SUMMARY OF THE INVENTION
[0010] Accordingly, one aspect of the present invention is to provide a reusable/disposable (resposable) sensor having a disposable adhesive tape component that can be removed from other reusable sensor components. This hybrid sensor combines the longevity and associated cost advantages of the reusable sensor with the performance features of the disposable.
[0011] In one embodiment of the resposable sensor, the disposable tape includes an information element along with a mechanism for the electrical connection of the information element to the emitters. The information element provides an indication to an attached oximeter of various aspects of the sensor.
[0012] According to another embodiment, the information element provides an indication of the sensor type. According to yet another embodiment, the information element provides an indication of the operating characteristics of the sensor. In yet another embodiment, the information element provides security and quality control. For instance, the information element advantageously indicates that the sensor is from an authorized supplier.
[0013] According to yet another embodiment, the information element is advantageously located in the disposable portion and configured to be in communication with the reusable portion via a breakable conductor. The breakable conductor is also located within the disposable portion such that excessive wear of the disposable portion results in isolation of the information element, thereby indicating that the disposable portion should be replaced. Moreover, the information element may comprise one or more passive or active components, ranging from a single coding resistor to an active circuit, such as a transistor network, a memory device, or a central processing component.
[0014] Therefore, one aspect of the present invention is a pulse oximetry sensor including a reusable portion having an emitter configured to transmit light through tissue, a detector configured to receive light from tissue, a first contact, an external connector configured to attach to a monitor, and electrical circuitry configured to provide electrical communications to and from the external connector, the emitter, the detector and the first contact. The pulse oximetry sensor also includes a disposable portion configured to attach the reusable portion to the tissue. The disposable portion has an information element, a breakable conductor, and a second contact electrically connecting the information element and the breakable conductor, the second contact configured to create an electrical connection to the first contact when the disposable portion is combined with the reusable portion.
[0015] Another aspect of the present invention is a resposable sensor for noninvasively measuring a physiological parameter in tissue. The resposable sensor includes a reusable portion and a disposable portion. The disposable portion has at least one of an information element and a conductor electrically connected to the reusable portion. Moreover, the disposable portion is configured to secure the reusable portion to a measurement site.
[0016] Another aspect of the present invention is a method of providing disposable oximeter sensor elements. The method includes forming a disposable housing configured to receive a reusable electronic circuit. The method also includes forming at least one of an information element and a conductor associated with the disposable housing and configured to be disconnected from the reusable electronic circuit when the disposable housing is damaged, overused, or repeatedly attached.
[0017] Another aspect of the present invention is a method of providing reusable oximeter sensor elements. This includes forming a reusable electronic circuit configured to electrically connect with electronic components of a disposable housing and to employ the disposable housing for attachment to a measurement site.
[0018] Another aspect of the present invention is a method of measuring a tissue characteristic. This method includes creating a sensor through combining reusable electronic circuitry with a first disposable material such that an electrical connection is made between the reusable electronic circuitry and electronic components associated with the first disposable material. Moreover, the method includes attaching the sensor to a measurement site, removing the sensor, separating the reusable electronic circuitry from the first disposable material, and recombining the reusable electronic circuitry with a second disposable material.
[0019] Another aspect of the present invention is a pulse oximeter having a sensor including a reusable portion and a disposable portion. The disposable portion includes an information element electrically connected to the reusable portion through a breakable conductor. The breakable conductor is configured to electrically disconnect the information element from the reusable portion in the event of overuse, damage, or excessive reattachment of the disposable portion. Moreover, the pulse oximeter includes a monitor, and a cable for connecting the sensor to the monitor.
[0020] Yet another aspect of the present invention is a pulse oximeter sensor element having a disposable material that incorporates electronic components. The disposable material is configured to removably receive reusable oximeter sensor elements such that the electronic components electrically connect with the reusable oximeter sensor elements. Moreover, the disposable material is configured to secure the reusable oximeter sensor elements to a measurement site.
[0021] Another aspect of the present invention is a pulse oximeter sensor element including reusable electronic circuitry configured to electrically connect with electronic components of a disposable material and to employ the disposable material for attachment to a measurement site.
[0022] Another aspect of the present invention is a resposable sensor for measuring a tissue aspect. The resposable sensor includes a face tape, a base tape removably attached to the face tape, and reusable measurement circuitry removably secured between the face tape and the base tape. The reusable measurement circuitry is also configured to connect to an external monitor and configured to measure an aspect of tissue at a measurement site. Moreover, the face tape includes at least one of an information element and a breakable conductor connected to the reusable measurement circuitry when the reusable measurement circuitry is secured to the face tape.
[0023] Another aspect of the present invention is a resposable sensor having a reusable emitter and detector removably connected to a patient cable. The resposable sensor also includes a replaceable envelope having electronic circuitry configured to attach to the reusable emitter and detector such that the electronic circuitry monitors at least one characteristic of the resposable sensor. Moreover, the replaceable envelope is configured to removably receive the reusable emitter and detector and configured to secure the reusable emitter and detector to a measurement site.
[0024] Yet another aspect of the present invention is a pulse oximetry sensor having an emitter, a detector and a connector. The emitter is configured to transmit light through tissue and the detector is configured to receive light from tissue to measure a physiological parameter. Further, the connector is configured to provide electrical communications between the detector and emitter and a monitor. The pulse oximetry sensor includes a reusable portion having the emitter, the detector, the connector and a first contact in communication with the connector. Moreover, the sensor includes a disposable portion having a second contact, an information element and a conductive element disposed on an adhesive substrate configured to secure the reusable portion to a measurement site. The disposable portion removably attaches to the reusable portion in a first position such that the first contact contacts the second contact. The disposable portion detaches from the reusable portion in a second position. Also, the conductive element has a continuity condition connecting the information element to the second contact so that the information element is in communication with the connector. The conductive element has a discontinuity condition isolating the information element from the second contact and the connector. The discontinuity condition results from use of the disposable portion substantially beyond a predetermined amount.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 illustrates a circuit diagram of a conventional disposable sensor having an information element.
[0026] FIGS. 2A and 2B illustrate perspective views of the conventional disposable sensor.
[0027] FIG. 3 illustrates an exploded view of a resposable sensor having two disposable tape layers, according to one embodiment of the invention.
[0028] FIG. 4 illustrates a top view of one of the disposable tape layers of FIG. 3 incorporating an information element.
[0029] FIG. 5 illustrates a top view of one of the disposable tape layers of FIG. 3 incorporating a breakable conductor.
[0030] FIGS. 6A and 6B illustrate cross-sectional views of a portion of the disposable tape layer of FIG. 5 .
[0031] FIG. 7 illustrates a top view of one of the disposable tape layers of FIG. 3 incorporating the information element with a breakable conductor.
[0032] FIG. 8A and 8B illustrate a top view and a side view, respectively, of one of the disposable layers of FIG. 3 configured as a fold-over tape.
[0033] FIG. 9A illustrates a perspective view of a resposable sensor having a disposable portion configured as a tape sleeve and a reusable portion directly attached to a patient cable, according to another embodiment of the invention.
[0034] FIG. 9B illustrates a perspective view of a resposable sensor having a reusable portion removably attached to a patient cable, according to another embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0035] The configuration of an information element for an oximeter sensor and method of reading an information element with an attached oximeter is described in U.S. Pat. No. 5,758,644, assigned to the assignee of the current application, and incorporated by reference herein. Accordingly, the configuration and the implementation of an information element will be greatly summarized as follows.
[0036] FIG. 1 illustrates a conventional oximeter sensor circuit 100 . The oximeter sensor circuit 100 includes an emitter 105 comprising a first LED 107 and a second LED 110 . The oximeter sensor circuit further includes an information element comprising a resistor 115 . The first LED 107 , the second LED 110 and the resistor 115 are connected in parallel. The parallel connection has a common input electrical connection 120 and a common return 125 . The oximeter sensor circuit 100 also includes a photodetector 130 having an input electrical connection 135 connected to one end and having the common return 125 connected to the other end.
[0037] As mentioned, the resistor 115 is provided as an information element that can be read by an attached oximeter. In order to read the resistor 115 , the oximeter drives the oximeter sensor circuit 100 at a level where the emitter 105 draws effectively insignificant current. As is well understood in the art, the emitter 105 becomes active only if driven at a voltage above a threshold level. Thus, at this low level, significantly all of the current through the input electrical connection 120 flows through the resistor 115 . By reducing the drive voltage across the input electrical connection 120 and common return 125 to a low enough level to not activate the emitter 105 , the emitter 105 is effectively removed from the oximeter sensor circuit 100 . Thus, the oximeter can determine the value of the resistor 115 .
[0038] The value of the resistor 115 can be preselected to indicate, for example, the type of sensor (e.g., adult, pediatric, or neonatal), the operating wavelength, or other parameters about the sensor. The resistor 115 may also be utilized for security and quality control purposes. For example, the resistor 115 may be used to ensure that the oximeter sensor circuit 100 is configured properly for a given oximeter. For instance, the resistor 115 may be utilized to indicate that the oximeter sensor circuit 100 is from an authorized supplier.
[0039] An information element other than the resistor 115 may also be utilized. The information element need not be a passive device. Coding information may also be provided through an active circuit, such as a transistor network, memory chip, or other identification device.
[0040] Furthermore, it will be understood by a skilled artisan that a number of different circuit configurations can be implemented that allow the oximeter sensor circuit 100 to include an information element. For example, the emitter 105 and the information element may each have individual electrical connections.
[0041] As mentioned above, the resistor 115 is preselected such that at low drive voltages, it is the only circuit element sensed by the oximeter. On the other hand, the resistor 115 can also be preselected be of a sufficiently high value that when the drive voltage rises to a level sufficient to drive the emitter 105 , the resistor 115 is effectively removed from the oximeter sensor circuit 100 . Thus, the resistor 115 does not affect normal operations of the emitter 105 . In summary, an information element may form an integral part of the oximeter sensor circuit 100 by providing valuable information to the attached oximeter.
[0042] FIGS. 2A and 2B illustrate a conventional disposable sensor 200 . The disposable sensor 200 includes an adhesive substrate 205 having an elongated center portion 210 with front and rear flaps, 215 and 220 , extending outward from the elongated center portion 210 . The adhesive substrate 205 may also have an image 225 superimposed on the adhesive substrate 205 so as to indicate proper use.
[0043] The elongated center portion 210 includes the oximeter sensor circuit 100 of FIG. 1 . For example, the emitter 105 is housed on an underside of the elongated center portion 210 approximately beneath the superimposed image 225 . Thus, as shown in FIG. 2A , the emitter 105 may be housed approximately beneath the asterisk superimposed on the image of a fingernail. On the other hand, the photodetector 130 is housed on the topside of the elongated center portion 210 in proximity with the rear flaps 220 .
[0044] The elongated center portion 210 further includes an electrical connector 230 to drive the emitter 105 and to receive an output from the photodetector 130 . The electrical connector 230 is preferably configured to attach to a connector cable 235 via a sensor connector 240 . Also, the connector cable 235 attaches to or connects with an oximeter via an oximeter connector 245 .
[0045] FIG. 2B illustrates an example of how the disposable sensor 200 wraps the front and rear flaps 215 and 220 around a finger such that the adhesive substrate 205 provides a secure contact between the patient's skin, the emitter 105 and the photodetector 130 . FIG. 2B also illustrates an example of the sensor connector 240 (shown in broken lines) encompassing the electrical connector 230 .
[0046] As shown in FIGS. 1-2B , the conventional disposable sensor 200 integrates the components of the conventional oximeter sensor circuit 100 such that disposal of the disposable sensor 200 includes disposal of the longer lasting, expensive circuitry found therein.
[0047] FIG. 3 illustrates an exploded view of one embodiment of a resposable (reusable/disposable) sensor 300 according to the present invention. In this embodiment, the resposable sensor 300 includes a reusable portion 305 having an emitter 306 , a photodetector 307 and an electrical connector 308 . The resposable sensor also includes a disposable portion 310 having a face tape layer 315 and a clear base tape layer 320 . As shown in FIG. 3 , the disposable portion 310 attaches to the reusable portion 305 by sandwiching the reusable portion 305 between a face tape layer 315 and a clear base tape layer 320 .
[0048] According to this embodiment, conventional adhesives or other attaching methodology may be used to removably attach the face tape layer 315 to the clear base tape layer 320 . Furthermore, the adhesive properties associated with the base of the conventional disposable sensor 200 may be the same as the adhesive properties on the base of the clear base tape layer 320 , as both portions are provided to attach to the patient's skin.
[0049] As mentioned, the disposable portion 310 removably attaches to the reusable portion 305 in, for example, a sandwich or layered style. After removably attaching the disposable portion 310 to the reusable portion 305 , the resposable sensor 300 functions similar to the disposable sensor 200 , i.e., the resposable sensor 300 wraps flaps around a patient's tissue such that the emitter 306 and the photodetector 307 align on opposite sides of the tissue. However, in contrast to the disposable sensor 200 , the resposable sensor 300 provides for reuse of the reusable portion 305 . For example, when the disposable portion 310 becomes contaminated, worn, or defective, rather than discarding the entire resposable sensor 300 , the disposable portion 310 is removed such that the reusable portion 305 may be re-removably attached to a new disposable portion 310 . The discarding of the disposable portion 310 completely avoids cross-contamination through the reuse of adhesive tapes between patients without wasting the more costly and longer lasting sensor circuitry of the resposable portion 305 . Note that optional sterilization procedures may be advantageously performed on the reusable portion 305 before reattachment to either the new disposable portion 310 or to the patient, in order to further ensure patient safety.
[0050] FIG. 4 illustrates a top view of an embodiment of the face tape layer 315 of the disposable portion 310 of the resposable sensor 300 . According to this embodiment, the face tape layer 315 further includes an information element 405 as an integral part of the face tape layer 315 . In this embodiment, the information element 405 is a resistive element made by depositing a conductive ink trace having a predetermined length and width. As is known in the art, the length, width and conductivity of the conductive ink trace determines the resistance of the resistive element. The information element 405 is deposited between contacts 410 that are also implemented with conductive ink. It will be understood by a skilled artisan that a variety of methods can be used for mating the contacts 410 with the electrical circuitry of the reusable portion 305 . For example, the contacts 410 may advantageously physically touch the leads or the electrical connector 308 such that the reusable portion 305 is electrically configured to include the information element 405 . Such a configuration employs the oximeter sensor circuit 100 of FIG. 1 , having elements thereof distributed in both the reusable portion 305 and the disposable portion 310 of the resposable sensor 300 .
[0051] In the foregoing embodiment, the disposable portion 310 comprises the information element 405 along with the face tape layer 315 and the clear base layer 320 . As mentioned, the disposable portion 310 is removably attached to the reusable portion 305 and is employed in a similar manner as the disposable sensor 200 . In contrast to the disposable sensor 200 , when the disposable portion 310 of the resposable sensor 300 becomes worn, the disposable portion 310 and the information element 405 are discarded and the reusable portion 305 is saved. By discarding the information element, the attached oximeter can perform quality control. For example, if the reusable portion 305 is reattached to a patient using either a simple adhesive or any other non-authorized disposable mechanism, the resposable sensor 300 will not include the information element 405 . As mentioned above, an attached oximeter can recognize the absence of the information element 405 and create an appropriate response indicating inappropriate use of the reusable portion 305 of the resposable sensor 300 .
[0052] FIG. 5 illustrates a top view of yet another embodiment of the face tape layer 315 of the disposable portion 310 of the resposable sensor 300 . In this embodiment, the face tape layer 315 includes a breakable conductor 505 comprising a conductive ink trace located approximately along the periphery of the face tape layer 315 . This location ensures that a tear along the periphery of the face tape layer 315 results in a tear, or electrical discontinuity, in the breakable conductor 505 . For example, FIGS. 6A and 6B illustrate the face tape layer 315 in which the breakable conductor 505 is layered between a tape stock 605 and a tape base 610 . The reusable portion 305 of the resposable sensor 300 then attaches to the tape base 610 through a pressure sensitive adhesive (PSA) 615 . The PSA 615 , the conductor 505 and the tape base 610 include a score 620 such that multiple attachment and removal of the resposable sensor 300 will result in a peripheral tear, or electrical discontinuity, in the breakable conductor 505 , as illustrated in FIG. 6B .
[0053] Thus, like the information element 405 , the breakable conductor 505 also provides security and quality control functions. In particular, repeated use of the disposable portion 305 of the resposable sensor 300 advantageously severs at least one part of the breakable conductor 505 . An attached oximeter can detect such severance and initiate an appropriate notification to, for example, monitoring medical personnel. Providing security and quality control through a breakable conductor advantageously assists in controlling problems with patient contamination or improper attachment due to weakened adhesives.
[0054] FIG. 7 illustrates yet another embodiment of the face tape layer 315 . In this embodiment, the face tape layer 315 combines the breakable conductor 505 and the information element 405 . In this embodiment, the breakable conductor 505 is printed in a serpentine pattern to further increase the probability of a discontinuity upon the tearing of any portion of the face tape layer 315 . This combination of the information element 405 and the breakable conductor 505 advantageously adds significant safety features. For example, in this embodiment, the information element 405 is connected serially with the breakable conductor 505 and in parallel with the emitter 306 of the reusable portion 305 . Therefore, any discontinuity or tear in the breakable conductor 505 separates the information element 405 from the circuitry of the reusable portion 305 .
[0055] According to the foregoing embodiment, the attached oximeter receives an indication of both overuse and misuse of the resposable sensor 300 . For example, overuse is detected through the tearing and breaking of the breakable conductor 505 , thereby removing the information element 405 from the resposable sensor 300 circuitry. In addition, misuse through employment of disposable portions 310 from unauthorized vendors is detected through the absence of the information element 405 . Moreover, misuse from purposeful shorting of the contacts 410 is detected by effectively removing the emitter 306 from the circuit, thereby rendering the resposable sensor 300 inoperative. Therefore, the resposable sensor 300 of this embodiment advantageously provides a multitude of problem indicators to the attached oximeter. By doing so, the resposable sensor 300 advantageously prevents the likelihood of contamination, adhesive failure, and misuse. The resposable sensor 300 also advantageously maintains the likelihood of quality control.
[0056] A skilled artisan will recognize that the concepts of FIGS. 3-7 may be combined in total or in part in a wide variety of devices. For example, either or both of the breakable conductor 505 and the information element 405 may advantageously be traced into the clear base tape layer 320 rather than into the face tape layer 315 .
[0057] FIGS. 8A and 8B illustrate yet another embodiment of the disposable portion 310 of the resposable sensor 300 according to the present invention. As shown in this embodiment, the disposable portion 310 includes a face tape layer 805 and a clear base tape layer 810 . According to this embodiment, the clear base tape layer 810 includes a preattached section 815 and a fold over section 820 . The preattached section 815 attaches approximately one third of the face tape layer 805 to the clear base tape layer 810 . On the other hand, the fold over section 820 forms a flap configured to create a cavity between the face tape layer 805 and the clear base tape layer 810 . The cavity is configured to receive the reusable portion 305 of the resposable sensor 300 . According to one embodiment, a release liner 825 fills the cavity and separates the face tape layer 805 from the clear base tape layer 810 . When the release liner 825 is removed, newly exposed adhesive on the fold over section 820 and the face tape layer 805 removably attaches the reusable portion 305 between the face tape layer 805 and fold over section 820 of the clear base tape layer 810 .
[0058] According to another embodiment, the cavity is so formed that adhesive is not needed. For example, the fold over section 820 may comprise resilient material that can form a friction fit relationship so as to fix the reusable portion 305 in an appropriate position relative to the disposable portion 310 . On the other hand, the fold over section 820 may also comprise material having other than resilient or adhesive properties, but still allow for proper placement of the reusable portion 305 and disposable portion 310 on the patient. For example, hook-and-loop type materials like VELCRO® may be used.
[0059] It will be understood that a skilled artisan would recognize that the fold over embodiment of the responsible sensor 300 may employ the properties discussed in relation to FIGS. 3-7 , such as the information element 405 and the breakable wire 505 .
[0060] FIG. 9A illustrates an embodiment of a resposable sensor 900 integrated with an attached patient cable 905 , according to another embodiment of the invention. In this embodiment, a disposable portion 910 is attached to a reusable portion 915 by removably inserting the reusable portion 915 into a tape envelope 920 formed in the disposable portion 910 .
[0061] A skilled artisan will recognize that the disposable portion 910 may include the information element 405 , the breakable wire 505 , or both. Inclusion of one or both of these electronic components in the resposable sensor 900 advantageously provides the security, quality control, and safety features described in the foregoing embodiments.
[0062] FIG. 9B illustrates an embodiment of a resposable sensor 300 of FIG. 3 , according to another embodiment of the invention. According to this embodiment, the resposable sensor 300 removably attaches to the patient cable 905 via a sensor connector 925 . The patient cable 905 then attaches to an oximeter via an oximeter connector 930 . Use of the sensor connector 925 enables the replacement of both the reusable portion 305 of the resposable sensor 300 without replacement of the sensor connector 925 or patient cable 905 . In such an embodiment, the disposable portion 310 would follow a different, more frequent, replacement schedule than that of the reusable portion 305 .
[0063] A skilled artisan will recognize that the variety of configurations described above that include the information element 405 , the breakable wire 505 , or both, may be incorporated into the embodiment of FIG. 9B .
[0064] Although the foregoing invention has been described in terms of certain preferred embodiments, other embodiments will be apparent to those of ordinary skill in the art. For example, select aspects of FIGS. 3-9B may be combined. For example, the envelope configured disposable portion 910 of FIG. 9A may be combined with the reusable portion 305 of FIG. 3 .
[0065] Additionally, other combinations, omissions, substitutions and modifications will be apparent to the skilled artisan in view of the disclosure herein. Accordingly, the present invention is not intended to be limited by the reaction of the preferred embodiments, but is to be defined by reference to the appended claims.
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A pulse oximeter sensor has both a reusable and a disposable portion. The reusable portion of the sensor preserves the relatively long-lived and costly emitter, detector and connector components. The disposable portion of the sensor is the relatively inexpensive adhesive tape component that is used to secure the sensor to a measurement site, typically a patient's finger or toe. The disposable portion of the sensor is removably attached to the reusable portion in a manner that allows the disposable portion to be readily replaced when the adhesive is expended or the tape becomes soiled or excessively worn. The disposable portion may also contain an information element useful for sensor identification or for security purposes to insure patient safety.
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CROSS REFERENCE TO RELATED APPLICATIONS
This Application is a National Stage of International Application No. PCT/EP2010/53522, filed Mar. 18, 2010, which claims foreign priority to DE Application No. 10 2009 013 897.8, filed Mar. 19, 2009, both of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The invention relates to a method for the controlled dimming of an illuminant such as, for example, an LED, OLEDs or gas discharge lamps in accordance with digital dimming values that form desired values.
Such a method is known and is, for example, embodied with the circuit arrangement according to the prior art as illustrated in FIG. 1 . In the case of the known circuit arrangement, the illuminant is a gas discharge lamp 1 . The latter is operated with a ballast 2 that is embodied in a known way, and for this reason only the important components are illustrated in schematic form. The ballast 2 contains two series-connected electronic switches S 1 , S 2 that are supplied with a normal DC voltage. The two switches S 1 , S 2 are controlled by a digital switching unit 3 that can change the switching frequency and/or the duty ratio. A series resonant circuit formed from an inductor L and a resonant capacitor C 1 is located above the lower switch S 2 . The voltage drop across the resonant capacitor C 1 is fed to the lamp 1 via a coupling capacitor C 2 . There is a resistor in the circuit of the lamp. The voltage drop across the resistor R 1 is a measure of the luminous intensity produced by the lamp 1 , and can therefore be used to form analog actual values I a . The lamp 1 is dimmed via a digital control loop. Digital dimming values D d are made available via a DALI bus, for example, by a dimming value transmitter 4 , which can be arranged in a remote control center. Digital dimming values can, for example, be formed by 12 or 13 bits in order to ensure as fine resolution of the dimming stages as possible. The abovementioned analog actual values I a are converted into digital actual values I d in an A/D converter 6 . The digital dimming values D d and the digital actual values I d are compared with one another in a digital comparator 5 . For the comparison, the A/D converter 6 should have as far as possible the same bit number as the digital dimming values D d . A consequence of this in the case of a relatively high bit number of—as previously mentioned— 12 or 13 , for example, is that the A/D converter 6 operates relatively slowly. By means of the comparison of the digital dimming values D d and the digital actual values I d , the digital comparator 5 produces a digital control deviation X d that is fed to a digital controller 7 . The digital controller 7 produces therefrom a digital manipulated variable X d that is then fed to the digital switch unit 3 .
Since, as previously mentioned, the A/D converter 6 is relatively slow, it operates in the range of milliseconds. Consequently, the entire control loop is relatively slow.
BRIEF SUMMARY OF THE INVENTION
It is the object of the invention to modify the method specified at the beginning to the effect that the requirements placed on the components used are reduced.
In particular, the requirements placed on the A/D converter are to be reduced.
The essential idea of the invention here is not directly to digitize an analog feedback variable, but to digitize a control difference (control deviation) determined in the analog domain, in order then to process the latter in a digital control algorithm that determines a digital manipulated variable that influences the power of the illuminant.
In accordance with the characterizing part of an embodiment, the object is achieved by virtue of the fact that desired dimming values (termed “dimming values”) digitally prescribed for an operating device are firstly converted into analog dimming values, the analog dimming values are compared with corresponding analog actual values, and that an analog control deviation is determined therefrom, and in that the analog control deviation is then converted into a digital control deviation in order to carry out the digital control.
The invention is based on the finding that the control difference formed by subtracting the actual values from the desired values (dimming values) is smaller than the actual values led back by the lamp. When use is made of a PI controller, the control difference is even reduced to zero after settling. The relatively slight analog control deviation must admittedly subsequently be converted into a digital control deviation; the A/D converter required therefor can, however, have a reduced bit number. It therefore operates more quickly than the previous A/D converter with which the analog actual values have been converted into digital actual values. The entire control loop therefore also operates more quickly.
It is true that the inventive method requires the digital desired dimming values firstly to be converted into analog desired dimming values; the D/A converter required therefor is, however, not part of the control loop, and therefore does not influence the control rate thereof. According to the inventive embodiment, said control rate can lie in the range of microseconds.
Expedient developments of the inventive method are the subject matter of additional embodiments.
The invention further relates to a circuit arrangement for dimming an illuminant in accordance with digital dimming values—that form desired values—by digital control, having a comparator in which the dimming values and actual values corresponding to the brightness of the illuminant are fed, and that determines a control deviation by comparison, and having a digital controller to which the control deviation is fed, and that produces therefrom the analog manipulated variable for controlling the illuminant.
The abovedescribed circuit arrangement has already been mentioned as known at the beginning, and explained in conjunction with FIG. 1 .
The tasks set for the circuit arrangement correspond to those of the inventive method.
Circuitry for performing the tasks set consists in the fact that connected upstream of the comparator is a D/A converter that converts the digital dimming values into analog dimming values, that the comparator operates in analog fashion and determines an analog control deviation, and that connected downstream of the comparator is an A/D converter that converts the analog control deviation into a digital control deviation that is then fed to the digital controller.
Expedient refinements of the inventive circuit arrangement are the subject matter of additional embodiments.
It may be remarked at this juncture that the content of the previously mentioned embodiments (not quoted) are to constitute part of the disclosure of the description.
Finally, the invention also relates to a lighting system.
Exemplary embodiments of the invention are described below with the aid of the drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a circuit arrangement according to the prior art;
FIG. 2 shows an embodiment of the inventive circuit arrangement;
FIG. 3 shows the logarithmic dependence of the subjective perceived brightness on the physically measurable luminous intensity of the illuminant;
FIG. 4 shows the linear dependence of the luminous intensity on linearly digitized dimming values; and
FIG. 5 shows the dependence of the analog dimming values on the digital dimming values with a targeted exponential distortion for the purpose of compensating the logarithmic curve in accordance with FIG. 1 .
DETAILED DESCRIPTION
The known circuit arrangement in accordance with FIG. 1 has already been explained at the beginning in conjunction with the description of the prior art.
Components in FIG. 2 which are the same as those in FIG. 1 are denoted by the same reference symbols. Newly added components and blocks are presented in bold lines. The circuit arrangement according to FIG. 2 deviates from that of FIG. 1 initially in that the digital dimming values D d are converted into analog dimming values D a in a D/A converter 11 . The particular properties of the D/A converter 11 will be explained later further in conjunction with FIGS. 3-5 .
The analog dimming values D a are fed to the negative input of an analog comparator 13 formed by an operational amplifier. The analog actual values I a are fed to the positive input of an operational amplifier 12 , which has a variable gain V. The negative input of the operational amplifier 12 is connected to frame via a resistor R 4 ; however, it is connected to the output of the operational amplifier 12 via a feedback resistor R 5 . The analog actual value signals V*I a amplified by V are present at the output of the operational amplifier 12 . They are fed to the positive input of the comparator 13 . The comparator 13 forms the difference of its two input signals, and therefore produces the analog control deviation X a . The latter is fed to an A/D converter 14 . The A/D converter 14 produces from the analog control deviation X a a digital control deviation X d that is fed to the digital controller 7 . The processing of the digital control deviation X d is then performed as in the case of the circuit arrangement according to FIG. 1 .
It is important in the case of the circuit arrangement according to FIG. 2 that the digital dimming values D d are converted into analog dimming values D a , and that the amplified analog actual values V*I a are compared with the analog dimming values D a in a comparator 13 operating in analog fashion, in order to produce the analog control deviation X a , the latter then again being converted into a digital control deviation X d with the A/D converter. By comparison with FIG. 1 , in the case of the circuit arrangement according to FIG. 2 , the A/D converter 6 is thus omitted; in return, however, the D/A converter 11 and the A/D converter 14 are added. Despite this apparent complication, the circuit arrangement according to FIG. 2 has a decisive advantage, specifically that the control loop can operate more quickly. The A/D converter 14 , which is part of the control loop, need only convert the relatively small analog control deviation X a into a digital control deviation X d , and therefore manages with relatively few bits, for example 8 bits. This means that the control loop of the circuit arrangement in accordance with FIG. 2 operates more quickly than that of the circuit arrangement according to FIG. 1 , in the case of which the A/D converter 6 must process a high bit number, specifically that which is prescribed, as a rule, with the digital dimming value D d .
Reference is now made to FIGS. 3 to 5 in order to explain an additional function of the D/A converter 11 .
FIG. 3 shows the known dependence of the subjectively perceived brightness of the luminous intensity—which can be measured physically in candelas—of an illuminant. It is to be seen that, in the case of relatively high luminous intensities, equidistant jumps in luminous intensity are still perceived only as small jumps in luminous intensity. In the case of low luminance intensities, by contrast, equidistant jumps in luminous intensity are perceived as correspondingly high jumps in brightness.
FIG. 4 shows the normal linear relationship between the luminous intensity produced by an illuminant, in particular by a gas discharge lamp, and linearly digitized dimming values D d .
When the illuminant is controlled with equidistantly linearized dimming values D d in accordance with FIG. 4 , the observer has the sensation of brightness in accordance with FIG. 3 . The jumps in brightness differ in size in dependence on the luminous intensity. In order, nevertheless, to attain a brightness resolution that is satisfactory to a certain extent over the entire range of luminous intensity, the D/A converter 11 must have a relatively high bit number, for example 13 or 14 bits. This is certainly not a problem with regard to the reduced rate during dimming; all that is to be desired is rapid control. However, such a D/A converter is more expensive than a D/A converter with smaller bit number.
Use may be made of a D/A converter with a small bit number when one is chosen that additionally distorts exponentially, as is illustrated in FIG. 5 . The distortion signifies that, for linearized digital dimming values D d , analog dimming values D a are produced that are larger in the case of relatively high dimming values, and are smaller in the case of relatively low dimming values. In this way, the logarithmic curve in accordance with FIG. 3 is compensated by the exponential curve in accordance with FIG. 5 .
Such an exponentially distorting D/A converter 11 is used in the case of the circuit arrangement in accordance with FIG. 2 . It manages with 8 bits. Consequently, it also has 8 bit inputs. Such a distorting D/A converter is not mandatory, but advantageous for the reasons described. It is also possible to make use instead of a linearly converting D/A converter with a relatively high bit number which then, however, is—as mentioned—unfavorable in terms of cost.
As described above, the gain V of the operational amplifier 12 is variable. The gain V can be reduced when the A/D converter 14 reaches its extreme value, that is to say reaches its limit. In this case, the gain V of the operational amplifier 12 is reduced to half, for example. It is then necessary for the purpose of compensation to multiply the digital range in the A/D converter 14 by a factor of 2. The indication of reaching the extreme value EW is shown by the thick dotted line between the A/D converter 14 and the operational amplifier 12 . The reduction in the gain V of the operational amplifier 12 is performed in practical terms by a factor that results from a binary combination, that is to say 2, 4, 8, etc. In order for the last mentioned function to be triggered, very high control deviations X a must occur, and it is necessary in this case to accept that the multiplication in a digital range entails a worsening of the resolution.
The reduction in the gain V of the operational amplifier 12 can also be triggered in the case of another operating state, for example whenever lamp 1 has been started, or shortly thereafter, when the control system has settled specifically. It is only then that a fine resolution is desirable. The possibility that the gain V is reduced when the lamp 1 is started is indicated in FIG. 2 by the thick dashed line, which leads to the A/D converter 14 from the node of a voltage divider R 2 /R 3 situated over the lamp 1 via the path Z-Z. The signal voltage Z tapped from the voltage divider R 1 /R 2 corresponds to the lamp voltage, which changes after the starting.
There is, furthermore, the possibility of transmitting to the operational amplifier 12 advanced information relating to an approaching relatively large jump in dimming. Furthermore, it is possible to modify the electronic ballast 2 such that it executes a large jump in dimming only when the operational amplifier 12 reduces its gain V, and the reduction by multiplication in the digital range in the A/D converter 14 has been compensated.
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Techniques for controlled dimming of an illuminant such as, for example, a light-emitting diode (LED), an organic light-emitting diode (OLED) or gas discharge lamp are described herein. In one example, a control difference formed by subtracting actual values from desired values (dimming values) is smaller than actual values fed back by the lamp. Thus, without directly digitizing an analog feedback variable, the example digitizes a control difference (control deviation) determined in the analog domain, in order to process the latter in a digital control algorithm that determines a digital manipulated variable that influences power to the illuminant.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a sliding clasp fastener and more particularly to improvements in coupling elements used therein.
2. Prior Art
Sliding clasp fasteners or zippers find extensive application on garments, shoes, bags and other daily commodities as well as on industrial materials and products.
It has been a common practice to apply certain lubricating materials such as paraffin to the coupling elements of the fastener as and when the same fails to function smoothly in use. This was done by coating or otherwise depositing such lubricating material on the exposed outer surface of the fastener elements. The lubricating material thus applied was susceptible to separation from the elements under the influence of external physical forces exerted when cleaning, or by the chemical action of cleaning solvents in cleansers, or by repeated impinging contact of the coupling heads of mating elements during opening and closing of the fastener. As a result, the fastener would malfunction or even become inoperative.
SUMMARY OF THE INVENTION
With a view to overcoming the foregoing drawbacks of the prior art, the present invention is aimed at the provision of a sliding clasp fastener having a continuous row of plastic monofilamentary coupling elements which can retain the proper and smooth functioning over extended periods of use or even after it has undergone repeated cleaning.
According to the invention, there is a sliding clasp fastener comprising a pair of opposed support tapes, rows of coupling elements having a continuous spiral or meander formation provided with coupling heads and made from a plastic monofilament, and a slider member adapted to take said rows of elements into and out of sliding engagement with each other, said monofilament having a multiplicity of indents extending longitudinally thereof, and a lubricative agent filled in said indents. The indents may be of various forms but are in all cases oriented to extend longitudinally of a starting monofilament.
The invention will be better understood from the following descripting taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A, 1B and 1C are fragmentary views each schematically illustrating the form of filamentary fastener elements provided in accordance with the invention;
FIGS. 2A through 2D are cross-sctional views on enlarged scale each schematically illustrating the formation of indents filled with lubricative material in the surface of the fastener element;
FIG. 3 is a plan view of mating rows of fastener elements coupled together by and in a slider member;
FIG. 4 is a schematic view on enlarged scale illustrating the encircled portion E of the fastener element shown in FIG. 3, and
FIG. 5 is a cross-sectional view of the mating fastener elements coupled together in the slider member.
DETAILED DESCRIPTION
FIG. 5 shows a typical form of a sliding clasp fastener 10 which comprises a pair of opposed fastener support tapes 11, 12 carrying rows of coupling elements 13, 14 attached to the respective tapes as by stitchings 15 and taken into and out of mutual engagement by a slider member 16.
The coupling elements 13, 14 to which the present invention is directed are formed from a plastic filamentary material such as polyamide and polyester resins into a continuous spiral or meander formation, the illustrated embodiment being in spiral form as better shown in FIG. 3.
The plastic filament designated at 17 in FIG. 1 is provided in its peripheral surface with a multiplicity of minute indents 18, the term "indent" comprehensively representing a concave contour such as a groove or a recess, which indents are filled with a suitable lubricative material as hereafter described. The indents 18 shown in FIG. 1A are in the form of discrete lines of varied lengths; the indents 18' in FIG. 1B are in the form of dots, and the indents 18" in FIG. 1C are in the form of continuous lines. Importantly, the indents 18, 18' and 18" regardless of their different configurations are oriented and distributed longitudinally or in the direction of the length of the filament 17 for purposes hereafter described.
The indents 18, 18' and 18" are invisibly small, their widths and depths being of the order of 0.1 to 10s microns which may be determined such that elasticity and other functional requirements of the sliding clasp fastener are retained.
The indents 18, 18' and 18" may be formed by extruding a starting filament from a nozzle provided in its internal periphery with ridges and grooves designed to impart the particular indents to the peripheral surface of the filament 17. The indents may be also formed by passing the filament 17 in contact with a coarse surface having fine particles theron, or by blasting a stream of air mixed with particulate material over and longitudinally of the filament 17. Alternatively, the indents 18, 18' and 18" may be formed when spinning a starting filament with due consideration as regards draw ratio, temperature and other conditions as may be envisaged by one skilled in the art.
The lubricative agent to be used in the invention and designated at 19 in FIG. 2 may be any material which is resistant or immune to chemical attack by cleansers or their solvents used in cleaning the fastener. Such eligible materials are polyethylene, polysiloxane, polytetrafluoroethylene, polypropylene and the like.
The lubricative agent 19 may be dissolved or dispersed in a suitable solvent which can be applied uniformaly over the filament 17, and is well penetrative and volatile to permit quick drying. In the case of a low molecular weight polyethylene lubricative agent 19, substantially homogeneous fine particles of this material are dissolved or dispersed in the solvent, applied to the peripheral surface of the filament 17, dried to strip off the solvent and heated at a temperature above the melt point of ethylene to allow firm embedment of the lubricative agent 19 in the indents 18, (18', 18"). This process can be shortened by treating the filament 17 directly with liquefied polyethylene.
The application of the lubricative agent 19 to the filament 17, that is to fill and embed the agent 19 in the indents 18, (18', 18") in the filament 17, as schematically illustrated in FIGS. 2A-2D, is accomplished by means of roll coating, spraying or immersing in a solution or dispersion of lubricative agent 19. This can be done during extrusion of the filament 17, after the filament 17 has been formed into coupling elements 13, 14, or after a complete product fastener has been made, whichever is more convenient.
The type of lubricative agent 19 to be used depends upon the type of filament 17 which is most commonly polyamide and polyester resins. In the case of polyamide filament, the most suitable lubricative agent is polyethylene because it is less water-absorptive and can therefore minimize water-absorption of the filament per se so as to retain the properties and dimensional stability of the coupling elements 13, 14.
FIG. 3 shown on enlarged scale a fragmentary portion of the fastener 10 in which opposed rows of coupling elements 13, 14 are received in the slider member 16. The coupling heads 13' and 14' of the mating elements 13 and 14 are brought into and out of sliding engagement with one another in the direction of the arrows. Since the coupling heads 13', 14' are formed at the portions of the elements 13, 14 which are turned into adjacent convolutions as better shown in FIG. 5, the indents 18 in the elements 13, (14) at the region of their coupling heads 13'(14') are oriented to extend perpendicularly with respect to the plane of the fastener 10 or the plane of FIG. 4 showing the encircled portion E of FIG. 3 on more enlarged scale, or transversely of the width of the fastener 10. Movement of the slider member 16 in one direction or the other causes the coupling heads 13', 14' to come into sliding contact with each other, the contact taking place in a direction parallel to the plane of FIG. 4 with the result that the forces of sliding contact are directed to urge the lubricative agent 19 rather into than out of the indents 18. This ensures prolonged retention of the lubricative agent 19 on the coupling elements 13, 14 which leads to maintenance of lubricity and smooth coupling and uncoupling operation of the fastener 10. The indents 18, 18' and 18" are all so minute that elasticity desired of the filament 17 can be also retained.
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 warranted hereon, all such embodiments as reasonably and properly come within the scope of our contribution to the art.
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A sliding clasp fastener comprising a pair of support tapes carrying rows of coupling elements thereon and a slider adapted to couple and uncouple the rows of elements. The elements are formed from a plastic monofilament into a continuous spiral or meander formation. The monofilament is provided with a multiplicity of indents arranged to extend longitudinally thereof, the indents being filled with a lubricative agent.
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This application is 371 of PCT/JP97/00283 filed on Feb. 6. 1997.
FIELD OF THE INVENTION
The present invention relates to a preparation for external application containing tranilast as an active ingredient, more specifically to a preparation for topical application giving good transdermal absorbability of the active ingredient in the preparation due to improvement of the base and capable of sufficiently keeping an effective drug concentration in the skin tissue after application, which preparation is directed to treat keloid having little skin irritation, hypertrophic scar, psoriasis, palmoplantar pustulosis, prurigo nodularis including urticaria perstans, allergic dermatitis (e.g., atopic dermatitis, contact dermatitis, dutaneous pruritus, sting of an insect, priurigo simplex acuta, etc.), the other eczema and dermatitis including progressive palmoplantar keratoderma and lichen symplex chronicus.
BACKGROUND OF THE INVENTION
An antiallergic drug, tranilast, has been commercially available as a therapeutic agent for allergic diseases. It has also been reported to show excellent pharmaceutical effect on keloid and hypertrophic scar (Kiyoshi Ichikawa et al., Oyo Yakuri (Pharmacometrics) 43(5), 401 (1992), Haruo Suzawa et al., Nichi Yakuri-shi (Folio Pharmacol Japan) 99, 231 (1992)). Tranilast has been used in the dosage form for oral administration such as capsules, tablets, dry syrup, fine granules, and the like. However, the drug orally taken is absorbed from the digestive tract through portal vein to liver where the drug is metabolized to give a so-called first passing effect. Thereafter, a part of the drug is transferred to local sites and its biological availability is decreased. Accordingly, it is necessary to administer a relatively large amount of the drug so as to maintain the effective drug concentration in blood, which increases manifestation of side effects. Further, preparations for external application directly applied to local sites of skin, particularly patches, have been considered favorable for the treatment of keloids, hypertrophic scar, and allergic dermatitis so that it is necessary to maintain an effective drug dosage sufficiently in the skin.
Attention has been paid to patches as preparations for topical application as well as a new route for applying systemic drugs as transdermal drug delivery system (TDS). In other words, in TDS, a drug absorbed from its preparation through epidermis is taken into blood stream via subcutaneous capillary vessels while a portion of the drug is transferred directly to local skin tissues without being taken into blood stream. Aiming at such a topical application effect, a number of patches utilizing non-steroid anti-inflammatory drug systems (NSAIDS) have been already developed and commercially available.
Further, subcutaneous application by patches is effective as the controlled release method of drugs by which effects of drugs can be prolonged and the concentration of drugs in blood can be controlled. Thus, it is possible to suppress manifestation of side effects.
However, skin inherently has a property to defend the inside of body from foreign substances that may invade from the outside. Keratolytic agents such as Azone are sometimes used as a base in order to increase transdermal absorption of a drug. Such agents give high skin irritation and thus may possibly cause side effects such as an eruption on the skin. Transdermal absorbability depends on characteristics of the molecule, which extremely limits formulation of the drugs that can give effective transdermal absorption.
Tranilast is sparingly soluble in water. Among organic solvents, it is hardly soluble in methanol, ethanol, ethyl acetate, while it is soluble in dimethyl formamide, pyridine, dioxane, and acetone though these solvents are not suitable for the base of preparations for external application. The drug can be solved to some extent in a kind of fatty acid and its ester, animal and vegetable oils and fats, terpene compounds, and alcohols, but the solubility is not sufficient and the drug cannot be dispersed well in the preparations. This affects transdermal absorbability of tranilast and the solubility of the drug makes it difficult to formulate the drug into a patch.
As a preparation containing tranilast for external application, a patch containing tranilast has been developed, which contains a kind of fatty acid and alcohols as absorption aids to improve cutaneous absorbability (Japanese Patent Application Laid-Open No. Hei 4-99719). However, this patch requires a large amount of absorption aids, such as fatty acid ester or alcohols, which might possibly cause skin irritation.
A tranilast-containing ointment has also been developed, which contains a basic aqueous solution as an absorption aid (Japanese Patent Application Laid-Open No. Hei 6-128153). This preparation for external application has basic pH due to the basic aqueous solution contained as an absorption aid. The basic substance itself might possibly cause skin irritation. Thus, there are problems that make it difficult to put the preparations into practical use.
SUMMARY OF THE INVENTION
An object of the present invention is to solve the above described problems in the prior art to achieve the practical use of the preparation for external application containing tranilast as an active ingredient, which has good transdermal absorbability of the active ingredient in the preparation, sufficiently keeps a drug concentration effective in the skin tissues, and shows little skin irritation.
The earlier report (Toyomi Waseda, The Japanese Journal of Dermatology, 99 (11), 1159 (1989)) describes that the effective concentration of tranilast in the skin tissue for treatment of keloid patients is about 8 to 10 μg/g when it is orally administered in a dose of 300 mg/day in three divided doses for three days. Another earlier report (Yasuo Goto et al., Kiso to Rinsho (The Clinical Report), 25(15), 69 (1991)) discloses that in the experiment using rat carrageenan-induced granulation tissue model a dose-dependent inhibitory effect was observed when tranilast was orally administered in a dose of 50, 100, and 200 mg/kg for consecutive 14 days and the drug concentration in the skin tissue one hour after the final administration was 4.2±0.4, 10.3±0.9, and 23.17±1.7 μg/g, respectively. Consequently, the tranilast concentration in the skin tissue after its application to the skin should desirably be comparable to or higher than the values as described above.
Keloid, hypertrophic scar, and allergic dermatitis are diseases giving some appearance on the skin surface that is not only apparently ugly but also sometimes accompanied by strong itchiness or pain as subjective symptoms. Accordingly, it is preferable that preparations for external application to be directly applied to the diseased part should not produce irritation by contact and the base in the preparation does not cause skin irritation. Particularly, patches are preferably elastic and do not have undue strong adhesiveness so that little resistance occur when they are detached. In this connection, a cataplasm containing water or a soft type of plasters is desired.
The present invention provides a preparation for external application and a method of producing it to achieve the above object, which preparation contains an aqueous base comprising tranilast, its salt, or a mixture thereof as an active ingredient, in which the aqueous base comprises a dissolution medium, a dispersant, an absorption aid, an adhesive, and/or a form-keeping agent, and water, the active ingredient is dissolved in the dissolution medium, and dispersed in the aqueous base by means of the dispersant. The present invention provides such a preparation for external application comprising tranilast and a patch for external application which comprises a support having the preparation for external application coated thereon.
Further, the present invention relates to a method of producing a preparation for external application containing tranilast, which comprises dissolving an active ingredient selected from tranilast, its salt, or a mixture thereof in a dissolution medium, adding thereto a dispersant, and mixing the solution with an aqueous base comprising an absorption aid, an adhesive, and/or a form-keeping agent, and water, and to a method of producing a patch for external application which comprises coating the above preparation for external application on a support.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a permeation/diffusion cell used in the test for skin permeation rate of the drug in the preparation of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Tranilast, which is the active ingredient of the preparation for external application of the present invention, is N-(3,4-dimethoxycinnamoyl)-anthranilic acid represented by the following formula or salt thereof:
The content of tranilast in the preparation is preferably 0.05 to 5 wt %. If the content of the active ingredient is too low, its pharmacological effect is insufficient. If it is too high, it does not show additional merit and, thus, is economically disadvantageous.
In the preparation for external application of the present invention, the dissolution medium to solve tranilast therein is selected from oily substances including fatty acids and derivatives thereof, animal and vegetable oils and fats, terpene compounds, alcohols, crotamiton, N-methyl-2-pyrrolidone, and triethanolamine.
The fatty acids and derivatives thereof that can be used as the dissolution medium are monocarboxylic acids or esters thereof having 3 to 30 carbon atoms. The fatty acids include octadecanoic acid, oleic acid, and linoleic acid. The fatty acid esters include glycerol monocaprate, tetradecyl tetradecanoate, hexadecyl hexadecanoate, oleyl oleate, and isopropyl myristate. Further, fatty acid alkali metal salts are exemplified by fatty acid sodium salts.
The animal and vegetable oils and fats include almond oil, olive oil, camellia oil, persic oil, peppermint oil, soy bean oil, sesami oil, mink oil, cottenseed oil, corn oil, safflower oil, coconut oil, eucalyptus oil, castor bean oil, hydrogenated castor bean oil, soybean lecithin, and the like. The terpene compounds include menthol, menthone, limonene, pinene, piperidone, terpinene, terpinolene, terpinol, and carveol. The alcohols are non-aqueous alcohols, such as benzyl alcohol, and octanols.
Further, examples of organic solvents that can be used as the dissolution medium other than those described above include crotamiton, N-methyl-2-pyrrolidone, triethanolamine, and the like.
Among the above oily substances, preferable examples are oleic acid, linoleic acid, glycerol monocaprate, oleyl oleate, castor bean oil, hydrogenated castor bean oil, soybean oil, soybean lecithin, 1-menthol, menthone, limonene, benzyl alcohol, crotamiton, N-methyl-2-pyrrolidone, and triethanolamine. Particularly, crotamiton and N-methyl-2-pyrrolidone are most preferable because they do not only dissolve tranilast but also enhance its transdermal absorption. The dissolution medium may be used alone or in combination of two or more thereof. Its total content is preferably 2 to 5 wt %.
When a solution obtained by solving tranilast in the dissolution medium is mixed with the aqueous base comprising an absorption aid, an adhesive, and/or a form-keeping agent, and water upon production of the preparation for external application, tranilast must be uniformly dispersed in the final preparation. Since tranilast is extremely sparingly soluble in water as described above, it is not solved in part when mixed with the aqueous base and gives poor dispersibility. If the drug is not sufficiently dispersed in the preparation, its amount to be released is lowered, which results in a decrease in the amount transdermally absorbed.
According to the present invention, the preparation with good dispersibility can be produced by dissolving tranilast dissolved in the dissolution medium, adding the dispersion medium thereto, mixing the solution well to allow the dispersion medium to retain at least a part of, preferably substantially all amount of, tranilast, and kneading it with the aqueous base. The dispersion medium to be used is pharmaceutically acceptable solid powder, particularly inorganic solid powder, having ability to retain tranilast dissolved in the dissolution medium. Preferable examples of the dispersion medium are silicon dioxides such as silicon dioxide hydrate or soft silicic acid anhydride, and silicates such as magnesium silicate hydrate or aluminum silicate hydrate, with silicon dioxide hydrate (white carbon) being most preferred.
Namely, a preparation with good dispersibility can be prepared by dissolving tranilast in the dissolution medium, adding white carbon to the solution, mixing it thoroughly to allow tranilast to be adsorbed, and mixing the resulting dispersion with the aqueous base.
The ratio of the amount of the dispersion medium to the total amount of tranilast and the dissolution medium is ⅓ to ⅕.
The absorption aid for enhancing absorption of tranilast from the preparation into the skin tissue is selected from fatty acids and derivatives thereof that are used as a base in preparations for external application, animal and vegetable oils and fats, terpene compounds, alcohols, crotamiton, and N-methyl-2-pyrrolidone. Preferable examples thereof include oleic acid, 1-menthol, ethanol, propylene glycol, butanediol, 1,2,6-hexanetriol, benzyl alcohol, crotamiton, and N-methyl-2-pyrrolidone. These may be used alone or in combination of two or more thereof. Propylene glycol, butanediol, or N-methyl-2-pyrrolidone is most preferably used. These compounds can be added to the preparation in an amount of 0.5 to 10 wt %, preferably 2 to 5 wt %, to keep the sufficient drug concentration in the skin tissue after its application without causing skin irritation.
The pH value is another factor that enhances absorption of tranilast into the skin tissue. Tranilast is absorbed well into the skin at the pH range from the neutral region to the weak acidic region. Preferable pH range is 3.5 to 7.5 taking account of skin irritation of the preparation and form-keeping ability Citric acid and tartaric acid can be used to adjust the pH of the preparation.
The patch for external application is required not to cause contact irritation on the diseased part, to keep the form of the preparation, and to retain adhesiveness sufficiently, because the preparation is directly applied on the diseased part exposed on the skin surface. As the patch that satisfies the above requirements, aqueous types are preferably used though non-aqueous soft type plasters can also be used.
Water-soluble polymers to be used as the adhesives and/or the form-keeping agent includes polyacrylic acid and its derivatives, acrylate copolymer and its emulsion, cellulose derivative and its derivative, gum arabic, gelatin, casein, polyvinyl alcohol, polyethylene glycol, polyvinyl alcohol, polyethylene glycol, polyvinyl pyrrolidone, methyl vinyl ether/maleic anhydride copolymer and its emulsion, and naturally-occurring polysaccharides. These compounds may be used alone or in combination of two or more thereof. Its total amount to be added to the preparation ranges from 5 to 15 wt %. Preferably, polyacrylic acid and its derivatives, and acrylate copolymer and its emulsion are used. In the case of using sodium polyacrylate, it is possible to use as an aluminum compound capable of crosslinking activated alumina, synthetic aluminum silicate, aluminum hydroxide, and the like.
Examples of fat-soluble polymers that can be used as the adhesive and/or the form-keeping agent include natural rubber, isoprene rubber, polyisobutyrene rubber, styrene-butadiene rubber, styrene-isoprene-styrene block copolymer, styrene-butadiene-styrene block copolymer, silicone, rosin, polybutene, lanolin, petrolatum, plastibase, beeswax, and solid paraffin.
Polyhydric alcohols that can be used as the adhesive and/or the form-keeping agent include glycerol, polyethylene glycol, ethylene glycol, and D-sorbitol. These can be used alone or in combination of two or more thereof. The total amount to be added is preferably 5 to 40 wt %.
Using the above-described adhesive and/or form-keeping agent, it is possible to provide the tranilast-containing patch for external application that can keep adhesiveness, its form, and flexibility for a long time, with causing little skin irritation.
Further, if desired, it is possible to use a nonionic surface active agent or an inonic surface active agent, the other additives for medicines, for example, polyacrylic acid metal salt, bentonite, titanium oxide, and the like, in a necessary amount.
According to the present invention, the thus-prepared preparation for external application containing tranilast is spread on the support fabric such as flannel, nonwoven fabric, or the like and a film for peeling such as polyethylene, polypropylene, polyester, or the like on the exposed surface of the opposite side of the support fabric. The resulting products can be brought to market as a preparation for external application.
It is also possible to use the preparation for external application of the present invention as ointment or cream to be directly applied on the diseased part as it is without spreading on the support.
In the preparation for external application containing tranilast according to the present invention, tranilast, which is sparingly soluble in water, is dissolved in the dissolution medium and dispersed in the aqueous base with being retained by the dispersion medium. Thus, tranilast is uniformly dispersed in the aqueous base. Because of this, the active ingredient is easily released to provide high skin absorbability, its effective concentration in the skin tissue after its application is sufficiently maintained with little skin irritation.
DESCRIPTION OF PREFERRED EMBODIMENT
The following Examples will demonstrate the present invention in more detail, but are not construed to limit the scope of the present invention.
EXAMPLE 1
Three g of tranilast was dissolved in a mixed solution of 20 g of crotamiton and 10 g of ethanol by gradually heating to 60 to 70° C . After adding 7 g of white carbon thereto, the mixture was thoroughly mixed and ethanol was removed under reduced pressure. Then, 5 g of 1-menthol and 2.5 g of titanium oxide were added thereto and the mixture was mixed to prepare a tranilast solution. Separately, 25 g of tartaric acid was dissolved in 552 ml of water followed by adding 50 g of sodium polyacrylate, 60 g of polyacrylate starch, and 250 g of glycerol. The resulting mixture was mixed well to prepare an aqueous base mixture.
The tranilast solution, the aqueous base mixture, 0.5 g of dry aluminum hydroxide gel, and 25 g of methyl acrylate/2-ethylhexyl acrylate copolymer resin emulsion were uniformly kneaded to obtain 0.3% tranilast-containing preparation for external application. The pH of the preparation was 5.2.
EXAMPLE 2
Three g of tranilast was dissolved in a mixed solution of 20 g of crotamiton and 25 g of N-methyl-2-pyrrolidone and 10 g of ethanol. After adding 7 g of white carbon thereto and mixing the solution well, ethanol was removed under reduced pressure. Then, 5 g of 1-menthol and 2.5 g of titanium oxide were added and mixed to prepare a tranilast solution. Separately, 25 g of tartaric acid in 527 ml of water was mixed well with 50 g of sodium polyacrylate, 60 g of starch acrylate, and 250 g of glycerol to prepare an aqueous base mixture.
The tranilast solution, the aqueous base mixture, 0.5 g of dry aluminum hydroxide gel, and 25 g of methyl acrylate-2-ethylhexyl acrylate copolymer resin emulsion were kneaded uniformly to obtain 0.3% tranilast preparation for external application. The pH of the preparation was 5.2.
EXAMPLE 3
In the same composition containing tranilast and the base for external application as described in Example 1, 50 g of butanediol was added to the aqueous base mixture and glycerol was used in an amount of 200 g in place of 250 g to obtain 5% butanediol-containing tranilast preparation for external application.
EXAMPLE 4
In the same composition containing tranilast and the base for external application as described in Example 3, propylene glycol was used in place of butanediol to obtain 5% propylene glycol-containing tranilast preparation for external application.
EXAMPLE 5
In the same composition containing the base for external application as described in Example 1, 1% tranilast preparations for external application each having the pH of 4.3, 5.4, 6.3, and 7.4 were obtained using 10 g of tranilast, tartaric acid in an amount varied as shown in the following table, and various sodium polyacrylate (50 g) as shown in the following table.
Tartaric acid
Sodium polyacrylate
(g)
(Showa Denko k.k)
pH
Example 5-1
50
Viscomate NP-700
4.3
Example 5-2
20
Viscomate NP-700
5.4
Example 5-3
10
Viscomate NP-600
6.3
Example 5-4
0
Viscomate F480SS
7.4
Performance Evaluation Test
TEST EXAMPLE 1
Using the preparations of Examples 5-1 through 5-4, influences of pH on penetrability of the drug into the skin was evaluated by the in vitro test with the penetration rate as an index.
In this test, penetration/diffusion cell shown in FIG. 1 was used.
The rat abdominal skin was interposed in the fixing device 1 , a patch having the test preparation spread on the support was attached to the fixing device 2 so as to contact the preparation for external application with the rat abdominal skin on the fixing device 2 . In order to prevent air from entering the container 3 , 5.18 ml of Tyrode's solution was added thereto. The penetration/diffusion cell was placed in the incubator maintained at 37° C., Tyrode's solution 5 was stirred with the stirring bar 4 and a 0.5 ml portion of Tyrode's solution was sampled at each point of time within 1 to 7 hours. The drug concentration in the sampled solution was measured to calculate the penetration rate of the drug in the test preparation for external application into the rat abdominal skin. The drug concentration was measured by HPLC. The results are shown in Table 1.
Conditions for HPLC
Column:
CAPCELLPAK C18 (SG120), 4.6 mm × 150 mm
Mobile phase:
50 mM ammonium acetate buffer (pH 6.0)/
acetonitrile
≡ 750/250 (0 to 10.5 min)
→ 375/625 (10.5 to 15 min)
→ 750/250 (15 to 20 min)
Column temperature:
40° C.
Flow rate:
1.0 ml/min
Detection wavelength:
320 nm for tranilast
254 nm for internal standard
substance (ethyl p-
hydroxybenzoate)
Retention time:
5 min for tranilast,
10 min for internal standard substance
TABLE 1
Influences of pH on transdermal absorption of the
preparation for external application
Amount penetrated
(μg/cm 2 ) n = 3
Penetration rate* 1
pH of Base
1 hr
3 hr
5 hr
7 hr
24 hr
(5 to 24 hr)
4.3
0.00
0.02
0.15
0.40
4.21
0.22 ± 0.02
5.4
0.00
0.03
0.10
0.40
3.79
0.20 ± 0.03
6.3
0.00
0.00
0.12
0.35
2.93
0.15 ± 0.03
7.4
0.00
0.00
0.04
0.11
0.17
0.06 ± 0.02
* 1 μg/cm 2 /hr S.E.
TEST EXAMPLE 2
In the same manner as in Examples 3 and 4, the preparations were prepared so as to make each of the amount of the absorption aid, propylene glycol and butanediol, 2%, 5%, and and 10% and make the amount of N-methyl-2- pyrrolidone 2.5%. The resulting preparations were respectively spread on the support to give patches. Using the resulting patches, skin absorbability of the skin absorption aids, that is, propylene glycol, butanediol, and N-methyl-2-pyrrolidone, was evaluated by measuring the penetration rate of tranilast and the amount of tranilast accumulated in the skin. The results are shown in Table 2. The skin penetration rate was determined in accordance with the method as described in Test Example 1. The drug concentration in the skin was determined as described below.
Abdominal body hair of Wistar-Imamichi male rats (200 g) was cut with a hair clipper or a shaver under anesthesia with ether and the preparation was applied to the abdominals skin (3×3 cm). Eight hours after application of the preparation, the rats were sacrificed and the stratum corneum was removed thoroughly, by stripping with cellophane adhesive tape on the skin at the middle of the part where the preparation was applied. After removing fat, capillary vessels, and the like in dermis, a part of the dermis was taken out by punching with a puncher(φ1.0 cm) and cut into thin strips. Then, the thin strips of the skin section were mixed with 2 ml of methanol, 1 ml of an ethanol solution of ethyl p-hydroxybenzoate (internal standard substance) (10 μg/ml), and 0.5 ml of 50 mM ammonium acetate buffer (pH 6.0). The resulting mixture was homogenized well by microhomogenization and centrifuged at 15,000 rpm for 5 min. The resulting supernatant was applied to HPLC. The same conditions for HPLC as in Test Example 1 were followed.
TABLE 2
Effect of skin absorption aid on transdermal absorption
of tranilast
Penetration rate
Drug concentration
Absorption aid
(μg/cm 2 /h)
in skin (μg/g)
—
0.22 ± 0.01
26.01 ± 1.29
2% propylene glycol
0.38 ± 0.07
44.93 ± 4.66
5% propylene glycol
0.33 ± 0.07
45.92 ± 8.71
10% propylene glycol
0.68 ± 0.10
35.24 ± 0.69
2% butanediol
0.50 ± 0.13
36.04 ± 5.08
5% butanediol
0.64 ± 0.18
49.74 ± 7.19
10% butanediol
0.83 ± 0.07
33.08 ± 0.92
2.5% N-methyl-2-pyrrolidone
0.68 ± 0.10
53.23 ± 10.88
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An external preparation containing tranilast which is excellent in the release of the active ingredient contained therein, achieves a high percutaneous absorption, fully ensures the effective drug concentration in the skin tissue and little irritates the skin This preparation is composed of an aqueous base containing as the active ingredient tranilast, its salt or a mixture thereof. The aqueous base contains a solubilizer for tranilast, a dispersant, an absorption aid, an adhesive and/or a shape retenting agent, and water. The active ingredient has been solubilized by the above-mentioned solubilizer and dispersed in the aqueous base by the above-mentioned dispersant.
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CLAIM OF PRIORITY
This claims priority to U.S. Application 61/928,079 filed on Jan. 16, 2014, the contents of which are herein fully incorporated by reference in its entirety.
FIELD OF THE EMBODIMENTS
The field of the invention and its embodiments relate to an apparatus for use in conjunction with a key ring or other secondary item. In particular, the embodiments describe an apparatus that has an anti-slip layer disposed on a surface thereof that can be used to open stubborn plastic bags and other similarly situated layers of material.
BACKGROUND OF THE EMBODIMENTS
Plastic bags are typically used by consumers to hold or haul goods purchased at a particular retailer or discard waste. These bags are often reused for storage or waste, but other times they are simply thrown away. Disposable plastic bags have been used throughout this country and others for decades, but their use rose to prominence, in the 1980s, in supermarkets and later became a staple in most shopping centers.
As the usage of plastic bags increased, it became advantageous for the manufacturers of these bags to create a cheaper bag. This led to plastic bags being produced that were thinner and thinner. These bags are often tightly rolled as to minimize the space they take up in retail outlets.
Additionally, the manufacturing of these bags often result in small static charges being applied to the bags. The end result is extremely thin layers of plastic tightly pressed together and exhibiting static charges. This often provides difficulty for the consumer in opening such bags in a proper and efficient manner. In a time where efficiency and technological advances are prominent, these bags provide neither. Thus, there is a great need for a device that allows one to readily and efficiently assist an individual in opening a plastic bag without the use of adhesives.
Further, such an apparatus may be helpful in separating other items such as waste bags for animals. Often when walking a dog, an owner will carry a plastic bag for removal of pet waste from a public area or property. It can be challenging to try to open the bag in a timely fashion to prevent the dog or other pet or person from stepping in the waste before removal. Dog owners may also have a pet waste disposable bag dispenser attached to the dog leash. The roll of plastic bags in the dispenser are tightly rolled to minimize the space they take up in the dispenser which make them very thin and very difficult to open.
Further, such an apparatus may be beneficial in reducing and preventing the spread of germs. Typically supermarket customers lick their fingers when plastic bags in departments such as the produce and bakery department are difficult to open. Additionally, employees of a retailer, such as grocery store employees, also lick their fingers at check out when plastic bags are difficult to separate. Human skin, including our fingers can carry many germs including those that cause colds and the flu.
Additionally, many people have similar issues with paper products. In many people grip and dexterity decreases as one ages. Further, pages of books and magazines and the like can become stuck together and are difficult to turn. Other tasks involving many layers of paper such as handing out paper to school children or counting money can lead to painful paper cuts and prolonged paper handling times due to the paper being difficult to separate.
Thus, there is a need for an invention that can effectively assist a user in separating thin layers of material in an efficient and expeditious manner. This also enables those with decreased dexterity and grip strength a practical solution to facilitate usage of all items regardless of age or ability. The present invention and its embodiments meets and exceeds these objectives.
Review of Related Technology
U.S. Pat. No. 4,601,690 pertains to a plastic bag opening device that has a flexible U-shaped member which can be slipped over the slit edge of a plastic bag. Multilayer adhesive strips are affixed to the inside of the ends of the U-shaped member so as to contact the sides of the plastic bag when the U-shaped member is forced to a closed position. As the U-shaped member is flexed to an open position the sides of the bag adhere to the adhesive substance on the end of each exposed layer so that the sides of the bag are pulled apart from each other.
International Application WO2012/078106 pertains to a device for facilitating the separation of thin objects which adhere to each other, such as for example bags of plastic or similar material, and which consists of a stationary body. A number of grooves extending in defined directions, which are embedded in said body, are arranged to exhibit a sticky surface or another material adhering to an intended applicable object, and which grooves converge in a common center for picking up one separable side of a bag or another thin object by means of a grip obtained between the thumb and further finger/fingers of the person in question.
International Application WO2009/108078 pertains to a plastic bag with friction fields for opening, which has friction fields applied, on the outer sides of bag walls, close to the bag end which is opened, friction fields having the coefficient of friction with human fingers greater than the coefficient of friction between the bag walls and the fingers. If these two facing friction fields are touched by fingers (e.g. one field by the thumb and the facing one by the index finger) and the fingers perform a sliding movement to open the bag, such construction would render the opening of the bag much easier.
GB2271756 pertains to a plastic bag that has an enhanced-friction patch provided at or near the top of its side wall, formed e.g. by knurling, stippling, or perforation. The patch facilitates manual gripping of the side walls, making it easier to separate them when opening the bag. The advantage is most pronounced with mass-produced plastic bags of very thin material (e.g. less than 50 μm).
Various devices and methodologies are known in the art. However, their structure and means of operation are substantially different from the present disclosure. Known devices employ adhesives and are typically bulky and not readily portable or reusable. The other inventions also fail to solve all the problems taught by the present disclosure. By providing a small tag with an anti-slip surface, the present invention provides a quick, portable, inexpensive, and reusable way to separate layers of thin materials. At least one embodiment of this invention is presented in the drawings below and will be described in more detail herein.
SUMMARY OF THE EMBODIMENTS
An apparatus is described and taught having a tag body with at least an upper surface and a lower surface, wherein at least one of the upper or lower surfaces is partially or completely coated in an anti-slip substance.
In another embodiment, there is an apparatus having a tag body with an upper surface and a lower surface with an aperture extending there through; and a resin disposed on at least the upper surface or the lower surface of the apparatus, wherein the resin either partially covers or fully covers the respective surface or surfaces, wherein the resin forms a rounded, sloping edge where it meets the edge of the apparatus.
Generally, the apparatus can have a number of shapes and sizes depending on user preferences including ergonomics. The apparatus has a tag body that may comprise a number of materials including but not limited to metal, plastic, resin, composite, glass, stone, fiberboard, paper, or the like or any combination thereof. Further, the tag body may have an aperture that provides for the attachment of a charm, bracelet, necklace, key chain ring or the like. On a surface of the tag body, an anti-slip substance is disposed thereon. The anti-slip substance may be on an upper surface, lower surface, or both. Additionally, the anti-slip substance may partially cover or completely cover the respective surface of the tag body. Along the edge or perimeter of the tag body, the anti-slip substance may be beveled or rounded to provide a smooth edge that helps to prevent user injury and damage to items used in conjunction with or kept in proximity of the apparatus.
The anti-slip substance is preferably an anti-slip, water resistant or water proof resin; however, other materials exhibiting similar properties may be used solely or in conjunction with one another. The anti-slip substance provides for a frictionable surface rather than employing an adhesive surface. This gives the apparatus the ability to work under less than ideal conditions while not sticking to other undesired objects. The anti-slip substance should have a coefficient of friction with plastic of at least 0.2 and more preferably about 0.5. In some embodiments, the coefficient of friction is about 1 to about 2. The preferable usage for the apparatus is to separate thin layers of material, namely plastic bags. In turn, the apparatus may be used to aid in separation of a number of different types of layered or unlayered material.
In general, the present invention succeeds in conferring the following, and others not mentioned, benefits and objectives.
It is an object of the present invention to provide an apparatus that is readily portable and transportable.
It is an object of the present invention to provide an apparatus that is durable and inexpensive.
It is an object of the present invention to provide an apparatus with an anti-slip surface that aids an individual in separating layers of an article of manufacture.
It is an object of the present invention to provide an apparatus that is water proof or water resistant.
It is an object of the present invention to provide an apparatus that can be used in conjunction with a secondary item such as a key chain ring, bracelet, necklace, or the like.
It is an object of the present invention to provide an apparatus that can be given to employees or customers of a retailer such as a grocery store for use with thin plastic bags.
It is an object of the present invention to provide an apparatus that is readily reusable.
It is an object of the present invention to provide an apparatus that generates a high coefficient of friction with most items, preferably plastic based items.
It is an object of the present invention to provide an apparatus that is lightweight and user friendly.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a top view of a first embodiment of the present invention.
FIG. 1B is a top view of a second embodiment of the present invention.
FIG. 2A is a side view of first embodiment of the present invention.
FIG. 2B is a side view of an alternate embodiment of the present invention.
FIG. 3 is a representation demonstrating the present invention used as intended in at least one scenario.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the present invention will now be described with reference to the drawings. Identical elements in the various figures are identified, as far as possible, with the same reference numerals.
Reference will now be made in detail to embodiments of the present invention. Such embodiments are provided by way of explanation of the present invention, which is not intended to be limited thereto. In fact, those of ordinary skill in the art may appreciate upon reading the present specification and viewing the present drawings that various modifications and variations can be made thereto without deviating from the innovative concepts of the invention.
Referring to FIGS. 1A and 1B , there is an apparatus 100 having a tag body 125 . The tag body 125 can come in a number of shapes and bear a number of designs. Preferably the size of the tag body 125 should be of a size to provide a sufficient workable surface area while not being overly cumbersome or interfere with daily affairs.
Generally, the tag body 125 should be resilient enough to be handled on a routine basis and can be stored in pockets alongside keys, electronics, and the like. Thus, the tag body 125 may be a metal, plastic, resin, composite, glass, stone, or the like or any combination thereof. In some embodiments the tag body comprises cardboard, paperboard, fiberboard, vinyl, foam board, and the like or any combination thereof. In some embodiments the tag body 125 is a plastic such as polyethylene terephthalate (PET), polyethylene (PE), high-density polyethylene, polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), low-density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), high impact polystyrene (HIPS) and polycarbonate (PC), or any combination thereof.
Alternatively, the tag body 125 may be a composite material, for example, Formica. Such materials can provide the needed strength and wear-resistant properties required whilst providing flexibility thereby helping to prevent the tag body 125 from bending and subsequently cracking or breaking.
The tag body 125 may also have an aperture 115 . Preferably, the aperture 115 is located towards a terminal edge of the tag body 125 thereby providing an adequate mechanism for attachment and providing a large, uninterrupted workable surface area. The aperture 115 may be designed such that the apparatus 100 can be attached to an object or secondary object such as a key chain ring 130 . Disposed on at least one of the upper surface 105 and lower surface 110 (see FIGS. 2A and 2B ) is anti-slip layer 120 . The anti-slip layer 120 may partially or fully cover the respective surface of the tag body 125 .
As shown in FIG. 1A , there may be a scannable barcode 150 disposed on a surface of the apparatus 100 . Thus, the present invention may embody a supermarket rewards card and be used in the same fashion, but including the dual function attributed to the anti-slip layer 120 . When one signs up for a rewards program through such a store they are given a similar type item with a logo and/or store name with a scannable bar code on the reverse. Thus, the apparatus 100 may function in the same capacity and the anti-slip layer 120 may either leave such a scannable barcode 150 uncovered or not impede the reader by covering the bar code 150 (i.e. opaque anti-slip layer 120 ). The envisioned uses, coloring, size, and shape of the apparatus 100 are virtually limitless and only limited by the particular intended usage.
In FIGS. 2A and 2B , there is the apparatus 100 as shown from the side. In FIG. 2A , the anti-slip layer 120 is disposed along the upper surface 105 only. In FIG. 2B , the anti-slip layer 120 is disposed along both the upper surface 105 and the lower surface 110 . Additionally differing amounts and coverage of the anti-slip layer 120 is shown between FIGS. 2A and 2B . The coverage and thickness of the anti-slip layer 120 can vary with the particular usage or user preferences. In both instances, the rounded, sloping shape of the disposed anti-slip layer 120 layer is shown. However, this is not the only configuration and it may be desirable in some circumstances to have a differently shaped anti-slip layer 120 .
In FIG. 3 , the apparatus 100 is shown being used in one manner as intended. Often when a user's fingers are dry, there is not adequate friction available between thin plastics and human skin. The apparatus 100 repels most liquids and generates a high coefficient of friction under less than ideal conditions. A user would hold the apparatus 100 by a portion of the tag body 125 . The anti-slip layer 120 is directed towards the intended target, in this case, a thin plastic bag 135 which may be a grocery bag, produce bag, trash bag, and the like or combinations thereof.
Using a shearing motion with the apparatus 100 and the thin plastic bag 135 , the anti-slip layer 120 possesses a sufficient coefficient of friction to enable such layers to be easily separated. This may aid in separating layers of individual thin plastic bags 135 from one another or aid in separating layers of the same bag thereby aiding in opening of the bag. A user simply touches the anti-slip layer 120 to the thin plastic bag 135 . Once contact between the two has been made, a user simply uses a desired motion thus creating friction and completing the task at hand. The items and uses for the apparatus 100 are not limited to opening or separating thin plastic layers and may have a practical functionality anywhere a frictionable surface is required. Due to the high friction properties of the apparatus 100 , the apparatus 100 is functional when a user's hands are covered by thick gloves or other non-friction producing items or substances.
Generally, the apparatus 100 described in FIGS. 1-3 can take a number of forms and shapes. In some instances, the shape may be influenced by its intended purpose. For example, many dog owners take their dogs for walks through various neighborhoods. Often these individuals carry small plastic baggies for cleaning up waste left behind on the road or the property of another. Thus, the apparatus 100 may be shaped like a dog bone or dog paw or the like and be intended to be used by dog owners in aiding the opening of such waste bags.
In other instances, the apparatus 100 can be used as a book mark and assist one in turning the pages of the book. The apparatus 100 may generally provide any type of assistance with separating or moving sheets of paper including in counting money and the aforementioned turning of pages of a book, magazine, journal, and the like.
The apparatus 100 may also bear a brand, logo, slogan, or the like. For example, shopping centers may include their logo and company colors on the apparatus 100 such as with a rewards card.
The anti-slip layer 120 should be selected to be anti-slip or non-slip rather than having adhesive qualities. This enables the apparatus 100 to readily be functional in its intended usage without accumulating debris or transferring adhesives to other materials such as car keys, cell phones, and the like. Such a quality further enables the apparatus 100 to be readily reusable.
Additionally, adhesive surfaces may damage the integrity of the thin plastic bag or other similarly situated material(s). The anti-slip layers 120 should be at least water resistant and may be water proof. This prevents water from interfering with the apparatus functionality 100 and potentially separating the anti-slip layer 120 from the tag body 125 .
The anti-slip layer 120 should also be selected for its coefficient of friction with different materials. Preferably, the most important material is plastics, but other materials and the anti-slip layer's 120 interaction with these different materials such as paper, either singularly or in conjunction, can make a difference. Preferably, the coefficient of friction with the intended/targeted material(s) is preferably 0.2 or greater and more preferably about 0.5. In some embodiments, the coefficient of friction is about 1 to about 2.
Generally, the anti-slip layer 120 may be a siloxane(s), resin, rubbers (both natural and synthetic), vinyl, textured metal, elastic polymers, acrylics, epoxies, and the like or any combination thereof. In a preferred embodiment the anti-slip layer 120 is a UV cured resin such as Rez-Cure® UV 1030 manufactured by Innovative Resin Systems of Wayne, N.J. Such an anti-slip layer 120 is compatible with plastic substrates and flexible enough (hardness Shore OO@24 hrs in room temperature=65-85) to be used thereon. Preferably, the anti-slip layer 120 is about ⅛″ inches thick and may be about 1/32″ inch to about 1 inch thick. Further, as noted above the edges of the anti-slip layer 120 are preferably beveled as shown in FIGS. 2A and 2B .
The apparatus 100 should be sized to be carried on a person without creating undue weight or distraction. The apparatus 100 may be irregularly shaped and should be between about 2.5 cm (1 inch) to about 13 cm (5 inches) in length and preferably about 7.6 cm (3 inches) in length. The apparatus 100 should be about 1.3 cm (0.5 inch) to about 7.6 cm (3 inches) in width and is preferably about 3.8 cm (1.5 inches) in width. The aperture 115 may be sized to accommodate a key chain ring 130 but may be alternatively sized to accommodate a bracelet, necklace, lanyard, string, or the like. It may be preferable to have the edge of the aperture 115 reinforced to prevent wear and tear.
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An apparatus may have an anti-slip coating covering all or some of the apparatus. The anti-slip coating may also be on an upper surface, lower surface, or both. The apparatus has an aperture to provide for attachment to a key chain ring or other similar objects. The apparatus can come in a number of shapes and sizes and can be designed with ergonomics in mind. The apparatus is generally useful for separating thin plastic layers such as those one encounters with plastic bags. The apparatus is used to provide a frictionable surface to efficiently separate the layers thereby facilitating opening of the plastic bag or similarly thin layers of material.
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REFERENCE TO RELATED APPLICATIONS
This application is based on provisional patent application 60/927,773 filed on May 4, 2007 and entitled “Electrically Traceable Fiber Optic Cables”, and is a divisional of U.S. patent application Ser. No. 12/114,117, entitled “Electrically Traceable and Identifiable Fiber Optic Cables and Connectors”.
FIELD OF THE INVENTION
This invention pertains to optical fiber cables and systems to transmit illumination and/or signals, and more particularly, to fiber optic cables which are electrically traceable and identifiable such that the inventory of physical fiber connections comprising a communications network can be determined by electronic and software means and to systems for electronic tracing of such cables.
BACKGROUND OF THE INVENTION
Fiber optic links can provide greater than THz bandwidths over long distances by transmitting one or more data streams at speeds in excess of 10's of Gigabits per second on a single fiber. Optical fiber offers several desirable characteristics, including low transmission loss, very compact size, light weight and relatively low cost. Nevertheless, the deployment of fiber optic cable does introduce challenges which make the installation, maintenance and operation of a fiber-based network demanding compared to the traditional copper-based network. Improved cabling and interconnect systems are required to address these challenges
In particular, one attribute of copper-based cables which is deficient in fiber optic cables is the ability to wirelessly trace the physical locations and termination points of cables throughout a network; for example, along a cable tray or within wall and ceiling plenums. Traditional electrical tracing of copper cables is accomplished by connecting a radio frequency (RF) tone generator to one or two electrical conductors to energize the cable with a sinusoidal or square wave voltage signal in the frequency range of 500 Hz to 33 kHz. A weak electromagnetic signature at this characteristic frequency is radiated along the entire length of the wire, whereby the wire functions as an extended wire antenna in which the surrounding environment provides a common ground. This RF signal transmits through non-conductive walls, floors and ceilings with minimal signal strength attenuation and is detected by a wireless, handheld RF tone detector. A tone detector, such as the type marketed by Psiber Inc. and Test-Um Inc., typically includes a voltage probe that emits an audible tone when placed in the vicinity of a cable carrying the tone. This method of voltage tone detection is the standard for tracking electronic cables.
Electronic tone-tracing techniques are ineffective in locating fiber optic cables, as typical fiber optic cables do not incorporate the electrical conductors that are needed to transmit an RF tone. Certain types of composite fiber optic cables include conductors that are embedded within the cable jacket and are difficult to access in a non-invasive fashion. While fiber optic cables could, in principle, emit an optical signal along their entire length, in practice the optical attenuation of fiber optic cables is extremely low, typically less than 0.1 dB/km, and the leakage along its length is a small fraction of this. Optical detectors that physically clip on to fiber to produce a lossy microbend are one of the few alternatives to detect light within the fiber. As a consequence, present day optical detection techniques are unable to trace the fiber in a wireless fashion and can not be performed if the cable lies behind obstructions such as a wall, ceiling, floor or a bundle of cables.
For specialized tracing applications, composite cables with optical fiber and copper wire within a single coextensive outer jacket have been developed. However, the expense and non-standard processes required to both optically and electrically terminate, that is, add connectors to such cables, have restricted their use. Because the major component in the cost of the cable is the connector, these specialized cable assemblies are relatively costly. The injection of a suitably strong electrical signal into the cable requires that the cable jacket be physically cut or removed to gain access to the wires, potentially causing damage to the fiber optic cable and compromising its strength. This adds serious reliability concerns to the already fragile optical fiber medium.
U.S. Pat. Nos. 6,743,044, 6,905,363 and 7,150,656 by ADC Telecommunications Inc. describe “tracer light” patchcords which include a pair of insulated electrical conductors within the cable jacket and utilize custom cable assemblies with dual electrical and optical connectors. The non-traditional cables and connectors only allow access to the conductors at the connectorized cable endpoints, unless the fiber optic cable jacket is partially removed by an invasive procedure. In addition, these cables are not well suited for on-site termination because they require a non-standard connectorization process wherein the individual optical fibers as well as the conductors are terminated. Therefore, standard quick termination connectors used for field connectorization are not applicable.
Alternately, U.S. Pat. Nos. 5,265,187 and 5,337,400 by Morin et al. disclose a fiber optic cable distribution frame including optical connector holders with electrical circuits and LED's to enable both ends of any patchcord to be visually identified. The patchcords include internal electrical conductors providing power to the LED status indicators. Similarly, U.S. Pat. No. 5,666,453 by Dannenmann describes a fiber optic jumper cable including a pair of insulated, electrical conductors and electrically powered light emitting diodes integrated into the fiber optic connectors.
Additional implementations of composite electronic-optical cables are described in U.S. Pat. No. 6,456,768 and in UK Patent application 2354600A by Weatherly. The latter application discloses a cable consisting of an individual or pair of optical fibers with an internal metal tracing element, whereby a tracing signal may be injected at one end of the cable and detected at the other end of the cable. The tracing element is located beneath the outermost jacket. Again, an invasive approach is required to access internal electrical conductors. RFID tags have been proposed to label the endpoints of cables, and present day techniques are adequate to manually read the identification of such tags using a handheld reader brought in close proximity to tag.
The ability to trace the physical location of fiber optic cables in a convenient and low cost fashion is an increasingly important feature of interconnect systems in today's networks. Moreover, the integration of cable tracing and identification with the network's Operations Support Systems (OSS) is a key enhancement enabling the remote and automated management and inventory control of physical connections with a fiber optic network
SUMMARY OF THE INVENTION
It is the object of this invention to provide fiber optic cables that include unique design features for readily locating and identifying fiber optic cable and its termination locations. We disclose fiber optic cables with external, continuous and conductive traces provided within physically recessed channels formed in the outer surface of the cable jacket. The one or more recessed conductors are immune to short circuits and crosstalk upon physical contact with other cables or grounded conductive elements such as cable raceways, yet they are readily contacted in a non-invasive fashion at any point along their length by attaching a cable clip. Such traceable fiber optic cables of various types are disclosed, including simplex, duplex and ribbon cables.
It is a further object of this invention to provide intelligent interconnect systems based on electrically conductive fiber optic cables in conjunction with electronic identification means such as radio frequency identification (RFID) tags. For instance, the pair of external conductors coextensive with the optical fiber can serve as a feeder line connecting to a remote antenna coil incorporated with the cable connector, wherein remote RFID tags attached to distant terminal equipment and in close proximity to the connector's antenna coil at the distal end of traceable cable can be electronically read via the cable's conductors at its proximal end. By applying this identification process to a multiplicity of cables within a network, the termination locations of these cables to transmission equipment within the network can be automatically inventoried and managed during moves, adds and changes to the network.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 illustrates a network incorporating traceable conductive fiber optic cables, including an inset detailing the cross section of a duplex style fiber optic cable with exterior conductive traces formed on the cable jacket;
FIG. 2 illustrates an example of an electrical contact device to insert an electrical tone onto fiber optic cable in a non-invasive fashion at any location along the cable;
FIG. 3 depicts a bundle of non-shorting traceable fiber optical cables in cross section;
FIG. 4 is an abstracted representation of an arbitrary, duplex conductive fiber optic cable including concavities configured to accommodate recessed, non-shorting conductive traces;
FIG. 5 schematically illustrates a system of electrically identifiable fiber optic interconnects;
FIGS. 6 (A) through (D) illustrate examples of fiber optic connectors with integrated antennas to excite and read RFID tags located in the vicinity of connector, and
FIGS. 7 (A) through (H) are cross section views of various examples of electrically traceable cables in accordance with this invention.
DETAILED DESCRIPTION OF INVENTION
In this invention, we disclose electrically traceable and identifiable fiber optic cables including one or more externally accessible conductive elements disposed within one or more concavities in the outer surface of the cable jacket, the concavities being longitudinally coextensive with the cable length and parallel or spirally arranged relative to the internal optical fiber. Electrical isolation of these uninsulated conductors, when in contact with other conductive elements, is maintained by fixedly attaching each conductor to a channel region bounded above by a tangential surface joining high points on the cable jacket surface and below by the depression in the cable jacket surface. The electrical isolation resulting from this structure prevents stray electrical conduction between adjacent conductive surfaces or bodies, such as other cables or grounded conduits, while enabling non-invasive electrical contact to the conductor(s) at any point along the length of the cable. This aspect of non-invasive electrical contact significantly reduces the complexity and cost of systems to trace and identify fiber optic cable.
As illustrated in FIG. 1 , the conductive element(s) 30 are conveniently energized by clipping the test lead(s) 43 of an electronic tone generator 40 at any point along the longitudinal extent of the traceable cable 8 and making directive conductive contact with the exterior conductive element(s) 30 - 1 , 30 - 2 , thereby eliminating the usual need for cable penetration, stripping or cutting, as would be required for conductors internal to cable jacket. The tone generator 40 launches an oscillatory electrical signal, typically an RF voltage signal with a 1 to 24 volt amplitude, from the contact point with cable and longitudinally outward towards the endpoints of the electrically traceable cable 8 .
The radiated power for an RF signal propagating along conductor(s) 30 - 1 , 30 - 2 is typically greater than 0.5 dB/km so a detectable RF electromagnetic signature at a characteristic frequency is emitted along the longitudinal extent of the cable and can be wirelessly detected. In contrast, by virtue of its low loss optical transmission characteristics, optical power leakage from unperturbed optical fiber 10 is less than 0.5 dB/km, making optical detection along its length extremely difficult. Therefore, the physical location of traceable fiber optic cable 8 and its endpoints can be ascertained by a wireless tone detection probe 82 , even if the intervening length of cable is physically obscurred.
Fiber optic cables are commonly routed within walls 70 and above ceiling tiles 83 in ceiling plenum 73 to interconnect remote users to a networking hub, network element or patch-panel. For example, in a typical enterprise network, a multiplicity of cables 8 terminated in fiber optic connectors 50 converge on a central location. Tracing and identifying cables within this massing of large numbers of independent yet physically indistinguishable cables is challenging and time-consuming.
In accordance with this invention, cable and connector identification is facilitated by providing traceable fiber optic cable elements for which an RF voltage tone generated by a tone generator 40 and transmitted to fiber optic cable 8 through a non-invasive clip-on electrical contactor 44 attached at any point along the longitudinal extent of the cable. Thereby, the entire length of cable 8 radiates a signal 88 with an RF frequency signature detectable by the handheld wireless voltage tone probe 82 placed in the vicinity (e.g., <1 meter) of an electrically excited cable. The probe 82 typically incorporates a compact antenna element attached to a high input impedance transistor or amplifier to detect the weak RF field in the vicinity of the cable and convert it into an audible tone or visual indicator of signal strength.
The inset to FIG. 1 details the cross-sectional structure of a particular embodiment of an electronically traceable duplex fiber optic cable. In this example, the duplex fiber optic cable 8 has a substantially dumbbell-shaped cross section with minor axis dimension of 1.6 to 3 mm and major axis dimension of 3.2 to 6.2 mm. The cable includes two optical fibers 10 , 10 ′ comprised of 0.125 mm diameter glass fiber with a 0.250 mm diameter acrylate coating. The coated optical fibers are surrounded by a tight buffer tube 16 of 0.5 to 0.9 mm outer diameter. The buffered optical fiber is circumferentially surrounded by aramid strengthening yard 12 and is encased by the extruded pvc jacket 14 . Two bare copper wires 30 - 1 , 30 - 2 of round cross section and 0.075 mm diameter (40 gauge) are partially embedded within concave recessions 18 formed in the flexible plastic jacket 14 and longitudinally coextensive with the cable. The typical length of such cables range from 1 meter to 10 km. This particular cable type is commonly referred to as a duplex “zipcord”, referring to its ability to be “unzipped” into two separate simplex cables without damaging the jackets surrounding the constituent fibers.
Electrical continuity between the tone generator and the cable is provided by a non-invasive clip-on electrical contactor that does not mechanically stress the internal optical fibers. For example, the clip 44 illustrated in FIG. 2 obviates the need to strip, cut, or otherwise penetrate the cable jacket, thereby preventing exposure of the delicate optical fiber. The clip 44 is attached to one wire 43 - 1 or both wires 43 - 1 , 43 - 2 from the tone generator 40 , each wire individually connected to one or both contactors 46 to provide direct conductive coupling. The contactors 46 are formed with a rounded tip and thickness sufficient to extend into the concave channels 18 bearing conductive elements 30 - 1 , 30 - 2 without damaging the cable. The spring-load on contactors 46 is sufficient to make direct, low resistance conductive electrical contact with cable.
FIG. 3 depicts a cross sectional view of a multiplicity of bundled and stacked, duplex style traceable fiber optic cables 8 supported along their lengths by a cable raceway 79 . The individual conductive elements 30 - 1 , 30 - 2 are non-shorting with the conductive elements of adjacent bundled cables as well as non-shorting to cable raceway 79 , which is potentially a grounded metallic surface. The unique placement of conductors within this cable structure thereby eliminates electrical crosstalk and allows the electrical tone to travel down the entire length of the cable without leaking to other conductors and producing a false identification. Moreover, this structure prevents electrical shorting to ground along the cable, which would prevent the launch of a voltage tone.
The traceable cable cross-sectional design is guided by mechanical considerations of buckling during cable bending. The tendency of the conductive element to delaminate or buckle relative to the cable jacket 14 during bending of the cable is substantially reduced by suitable sizing of the cable major and minor axes ( FIG. 4 ), precise positioning of the conductive elements and selection of suitable attachment method of a conductor to the cable exterior.
The compressive and tensile stress exerted on conductive elements during bending are reduced by minimizing the distance d between a conductive element 30 and the major axis 102 of the cable 8 . Duplex cables bend predominantly about the major axis due to the reduced geometrical rigidity of the cable jacket perpendicular to this direction. Equivalently, the moment of inertia about the major axis is smaller than the moment of inertia about the minor axis. As a result of the cross sectional asymmetry, the conductors lie very close to the major axis of the cable, thereby minimizing the tendency of conductors to buckle relative to the jacket.
In general, one or more conductive elements 30 - 1 , 30 - 2 may be located within one or more concave channels 18 , 18 ′ and 18 ″. Moreover, the cable cross-section may have an arbitrary shape. The form of concave channels 18 , 18 ′, 18 ″ is preserved along the longitudinal extent of the cable and are sized to retain un-insulated electrical conductors below the tangential cable surface 31 in a non-shorting fashion.
Example
Electronic System to Automatically Determine Physical Connections of Fiber Interconnects
In a particular embodiment of the invention, we disclose a system comprised of traceable fiber optic patch cords, electromagnetic radiating fiber optic connector elements, electrically responsive, wireless identification tags and a multiplexed reader circuit. This system automates several tasks within the physical layer of a communications network that are currently performed manually. In particular, the endpoints of individual physical interconnections are electronically ascertained and recorded to enable an accurate, real-time inventory of connections ( FIG. 5 ). This inventory is necessary to accurately guide subsequent reconfiguration and provisioning. Such monitoring is typically not provided by optical means because of the substantial costs associated with generating and detecting an optical monitor signal.
In accordance with this invention, the determination of physical network connections requires electronically traceable fiber optic cables whose conductors are attached at one end to an electrically radiating connector element. The radiating element is a linear 41 or coil 42 antenna element at the distal end of cable 8 , which communicates wirelessly with an RFID tag 57 or other wireless interface (e.g., Bluetooth). For example, RFID tags and antenna designs are described extensively by, for example, Y. Lee, Microchip Technical Note AN710, “Antenna Circuit Design for RFID Applications”, Microchip Technology, 2003.
Passive RFID tags 57 such as that shown magnified in FIG. 5 are typically energized by the current induced in substantially planar or cylindrical antenna coil 48 by coupling to a particular reader coil 42 on connector 50 - 2 driven with a time varying current. The RFID tag 57 comprises an integrated circuit element 49 attached to the coil 48 , wherein the circuit element rectifies the time varying induced voltage to power the same circuit 49 . The DC voltage must reach above a minimum value for the chip to activate. By providing this energizing RF signal, an RF reader circuit 59 can communicate with a localized tag 57 that has no internal power source such as a battery.
Energizing of and communication with the tag 57 requires efficient coupling between the substantially coaxial antenna coils of the reader and tag. An RF signal can be radiated efficiently if the linear dimension of the antenna is comparable with the wavelength of the operating frequency. For typical passive tags such as those from Microchip Technology Inc., the wavelength at their operating frequency of 13.56 MHz is 22.12 meters. Practical RFID tags and readers are made many orders of magnitude more compact by exploiting the resonance response of LC circuits.
Efficient sub-wavelength RFID antenna designs are based on a small loop antenna 48 and silicon integrated circuit 49 that is resonating or oscillating at a particular RF frequency by tailoring the inductance L and capacitance C of the circuit. For such a magnetic dipole antenna, the current i flowing through the coil generates a near-field magnetic field that falls off with distance r as r −3 . For 13.56 MHz passive tag applications, the inductance of the coil is a few microhenries and the resonant capacitor is a few hundred pF.
The coupling between the coil 48 of the tag and one of the multiplicity of reader coils 42 , selectable by multiplexer circuit 51 and activated by reader 59 , is analogous to a transformer comprised of primary and secondary coils. As a result, a voltage in the reader antenna coil is coupled to the tag antenna coil and vice versa. The efficiency of the voltage transfer at a particular RF frequency is increased significantly by providing coils with high quality factor (Q) LC circuits to resonantly enhance the magnetic coupling. The unique electronic identifier of the tag is transmitted, typically in a digital and time sequential representation, on an RF carrier at or near this particular frequency and this signal is processed by the reader circuit to extract the tag identifier.
An additional contribution to the inductance and capacitance of the reader circuit results from the finite length of the intervening traceable cable 8 , whose electrical elements 30 - 1 , 30 - 2 are equivalent to an RF transmission line with their own inductance and capacitance per unit length. Since there is typically a large variation in the length of cables within the network, in certain implementations it is advantageous for the reader circuit 59 to provide adaptive impedance or signal characteristics to maximize the coupling of the distant reader coil 42 under variable conditions in intermediate cable length and cable type.
As magnified in the lower portion of FIG. 5 , the traceable fiber optic cable 8 with conductor pair 30 - 1 and 30 - 2 carries an excitation voltage generated by the RF reader circuit 59 and directed by multiplexer switch 51 to one of a multiplicity of reader coils 42 , each integrated with a connector 50 - 2 . For example, the reader coil 42 is coupled to the tag coil 48 associated with the mating connector receptacle 54 - 2 of network element 58 -N. Passive, self-adhesive RFID tags 57 circumferentially surround connector ports 54 - 2 of the multiplicity of network elements 58 - 1 , 58 - 2 , . . . 58 -N. Such network elements include transceivers, test equipment, multiplexers, high-speed packet routers, fiber amplifiers and optical signal processors such as dispersion compensators. Such networks typically include 100's to 100,000's of separate fiber optic patch cords 8 .
The electronic identifier transmitted by the tag is associated with a description of each particular port of each particular network element within the communications network by the network element inventory database. Any changes to the network must be reflected in this database. Subsequent reading of an electronic identifier through a traceable fiber optic cable and lookup within the network's database reveals the connectivity of physical interconnections within the network. The total number of such interconnections for telecommunications networks can exceed 10's of million. Therefore, it is of great practical importance that each port of each network element is identified and RF tagged during installation and the inventory of connections are updated in real time should future moves, adds and changes (MACs) affect the disposition of the cable. This feature eliminates stranded, lost or misidentified fibers.
A single RFID reader circuit 59 may be switched among any of a multiplicity of traceable cables 8 by multiplexer circuit 51 to singly address one cable at a time. The reader circuit 59 outputs an excitation signal into that traceable cable 8 selected by the multiplexer circuit 51 and receives identification signal from the particular tag in proximity to the distal connector 50 - 2 of that particular cable. An RFID tag 57 located in the vicinity of the distal traceable cable end thereby electrically communicates through the intervening length of traceable cable 8 , the cable serving as an electronic communications conduit that relays the cable configuration information through the multiplexer 51 and RFID reader circuit 59 back to the network's OSS 55 .
The electronic overlay system described herein enables remote and real-time tracking, tracing and testing of individual physical fiber optic connections within a network with a substantial number of interconnections. Typically, as shown in partial cutaway view in FIG. 5 , the cable interface 56 is a manual patch-panel or automated fiber optic cross-connect having an array of fiber optic bulkhead adapters 54 including exterior facing mating receptacles disposed partially or fully on the panel front-side. These front panel receptacles include both electrical and optical contacts, wherein the electrical contacts communicate with the electrical conductors of the traceable fiber optic cable 8 and the optical contacts provide low insertion loss optical transmission. Such electrical contacts may include physically contacting conductive pad and brush or pin and plug type electrical connectors. Behind the cable interface surface 56 , electrical transmission element(s) 61 are separated from the optical transmission elements 62 by use of an electronic interconnect layer 63 interposed between connector ports 54 - 1 . The interconnect layer 63 may be a flexible electronic circuit on a kapton substrate, for example. In a further example, the multiplexer 51 may be integrated with the interconnect circuit layer 63 to minimize the number of conductors comprising element 61 .
To wirelessly read an RFID tag adjacent to the traceable cable, the electromagnetic signal should be sufficiently strong to unambiguously communicate with the tag. This is accomplished by forming a coil 42 or linear 41 antenna at the distal cable connector 50 - 2 which is sufficiently compact to fit on existing cables and connectors, while providing a local field strength adequate to both excite and read only the local RFID tag 57 attached to a port 54 - 2 the network element 58 - 1 . The relative orientation of the antenna coil elements are substantially coaxial to maximize the electrical coupling.
Additional examples of electrically radiating connectors are illustrated in FIGS. 6-A through 6 -D. The conductors 30 - 1 , 30 - 2 of the traceable cable 8 are terminated at the distal connector 50 - 2 in a linear antenna 41 ′, 41 ″, 41 ″′ or coil antenna 42 . The connectors are comprised of a polished fiber optic ferrule 34 , connector body 33 and flexible boot 52 attached to endpoint of cable 8 . Conductors 30 - 1 , 30 - 2 provide a continuous current path carrying the RFID reader's 59 excitation signal from the proximal 50 - 1 to the distal connectors 50 - 2 and carrying the RFID tag 57 identification signal from the distal connector back to proximal connector. The conductors 30 - 1 , 30 - 2 lie external or internal to the jacket of the traceable cable. The traceable cable functions as an electronic “tentacle” which enables an RFID circuit to read the distant tags and thereby ascertain the physical connections of the network.
In a particular example illustrated in FIG. 6-A , a dipole antenna 41 ′ is comprised of dipole elements 71 and 72 attached the connector body 33 and in communication with conductors 30 - 2 and 30 - 1 , respectively. The field lines, represented by dotted-dashed lines, are substantially parallel to elements 71 and 72 . The conductors comprising the antenna in this and in the following examples are advantageously coated or covered with a non-electrically conductive material to prevent unintentional electrical shorting.
In the example of FIG. 6-B , shown in side view and cross section A-A through boot 52 , the antenna 41 ″ is integrated with the flexible boot. The antenna element consists of a partial cylindrical conductor surface 74 attached to wire 30 - 2 and a substantially linear conductor 73 attached to wire 30 - 1 .
FIG. 6-C illustrates an alternate example in which the ground plane 76 and dipole element 75 are integrated within the connector body 33 .
A further example with an antenna coil comprised of multiple turns of conductor 77 forming a spiral around the connector strain relief boot 52 is illustrated in FIG. 6-D . In general, the conductor may alternately follow a serpentine path on or beneath the boot surface. Both ends of conductor 77 are attached to conductors 30 - 1 and 30 - 2 within or on the jacket of the composite fiber optic cable 8 . A current i passes through the conductor 30 - 1 into the coil 42 and returns via a second conductor 30 - 2 on or within cable 8 , thereby generating a field in the vicinity of distal connector 50 - 2 that can excite and read an RFID tag adjacent to this connector. This coil element 42 is produced by molding the strain relief boot 52 about a spiral wireform, for example. The conductor loops 32 comprising the coil lie on the outside, interior, or embedded within the strain relief boot 52 . Additionally, the coil may be located on or within a plastic housing forming the rigid connector body 33 that surrounds the optical fiber ferrule 34 , as illustrated in FIG. 5 . Composite cables with two conductors are typically utilized in this embodiment.
Example
Duplex Traceable Fiber Optic Cables
In a further aspect of the invention, we disclose traceable fiber optic cables in the form of duplex zipcord cables comprised of two multimode or single mode fibers. FIG. 7-A illustrates the duplex cable 8 in cross section, detailing the multiple concentric layers including the polyvinyl chloride (PVC) cable jacket 14 , aramid yarn 12 for pull strength and bend resistance, tight buffer coating 16 , and acrylate coated optical fiber 10 . In addition, the conductive surface of conductive wires 30 - 1 , 30 - 2 (40 gauge or 75 micron diameter copper) partially embedded in cable jacket are fully or at least partially exposed. Such cables 8 typically have cross sectional dimensions of 1.6 mm to 3 mm along the minor axis and 3.2 mm to 6 mm along the major axis. The glass portion of the fiber optic cable 10 is typically 80 to 125 microns in diameter with an acrylate coating of 250 micron thickness. Surrounding each fiber optic element is a tight buffer coating or loose tube 16 which provides additional strength.
In an additional cable implementation, the fiber optic jacket 14 can be printed or co-extruded such that the concave channel includes a continuous line, ribbon or fillet 30 - 1 comprised of conductive dye or polymer ( FIG. 7-B ). For example, Dow Corning PI-2000 conductive ink may be utilized. This silver polymeric interconnect material exhibits a sheet resistance of 8 to 81 miliohms per square for 25 micron print thickness. For comparison, copper has a sheet resistivity of 0.68 miliohms/square for a 25 micron thickness. Despite the larger resistance of these conductive compounds, a 30 meter long cable with 1 mm wide trace 25 microns thick would have a resistance of 244 ohms total. In many applications, the tracer conductors are open circuited at one end 50 , so this increased resistance has little or no impact on the ability to launch a voltage tone signal down the cable.
Since the cable 8 is printed with a thin conductive layer on its exterior, a technician can excite a tone in the cable in a non-invasive fashion and will not need to strip or remove the jacket 14 to gain access to internal conductors, as is necessary in the prior art. This is an important practical advantage in deployments of fiber optic cable because such penetration of the cable jacket weakens the cable, degrades cable integrity and can eventually lead to loss of optical transmission.
FIG. 7-C illustrates a cable 8 with a dog-bone shaped cross section incorporating recessed conductive element 30 - 1 located at the midpoint of the line joining the centers of the two optical fibers 10 and 10 ′. The conductive element 30 - 1 is positioned at a central point of the cable such that the tendency of the conductor to buckle relative to the jacket is minimized during cable bending. If the conductive elements were not located at the geometrical center of the cable, bending would potentially cause buckling of the conductive elements, for example a fine diameter wire, relative to the cable jacket. For a wire located 0.5 mm from the central axis of the cable, a 30 mm minimum bend radius would subject the wire elements to an elongation of <1.5%. Copper wire in the range of 38 to 75 microns diameter can typically elongate in the range of 10's of percent before reaching the yield point.
In general, the single conductive element 30 may be in the form of a metallic wire, foil, ribbon or conductive polymer. Since the excited conductive element acts as an antenna radiating the RF tone into the cable surroundings, in some applications it is adequate to utilize such a cable 8 with only a single conductor.
In a further example, FIG. 7-D illustrates a cable including one conductive element attached to the isthmus joining the two circular cross section constituent cables of this duplex zipcord cable 8 . The metallic wire 30 - 2 may be attached to the cable 8 by use of adhesive 20 lining the channel. For example, this adhesive is a flexible, low viscosity cyanoacrylate or a fusible, thermoplastic or “hot melt” coating which bonds the metallic wire to the longitudinally extended pocket. FIG. 7-E illustrates a cable whose jacket surface is coated over a substantial fraction of its outer surfaces with a thermoplastic adhesive. For example, such thermoplastic adhesives may be formulated to remain non-tacky at temperatures as high as 85 C while softening at 125-150 C. Suitable fusible thermoplastic adhesive coatings are available from manufacturers such as 3M Inc., Eastman Chemical and Cieba Geigy Inc. In a particular example, the coating 20 - 3 is 25 to 50 microns thick and the copper wire diameter 30 - 2 is 75 microns in diameter. Since the thickness of the wire is greater than the nominal thickness of the coating, the top surface of the copper wire 30 - 2 remains substantially uncoated, thereby enabling non-invasive electrical contact at any location along the length of the cable 8 .
Example
Simplex Traceable Fiber Optic Cable
In a further example of the traceable cable, simplex fiber optic cables are provided with a protective jacket of nominally circular cross section that is physically channelized along the entire longitudinal extent of the cable 8 ( FIG. 7-F ). The channel includes a partially exposed conductive element 30 - 2 longitudinally continuous along the cable length. Similarly, FIG. 7-G illustrates such a cable 8 with a pair of conductive elements 30 - 1 and 30 - 2 . In a further example, the channels follow spiral paths about the outer surface of the jacket. The placement of conductors within spiral channels mitigates the accumulation of excessive tensile or compressive forces which would otherwise arise for straight channels.
Example
Traceable Fiber Optic Ribbon Cable
FIG. 7-H illustrates a further embodiment of the traceable cable incorporating a multi-fiber 10 ′ ribbon cable within the channelized jacket. This traceable fiber optic ribbon cable 8 includes, for example, twelve optical fibers embedded within a kapton ribbon, the ribbon surrounded on all sides by strengthening fibers 12 within the plenum of elongated cable jacket 14 . Conductive elements 30 - 1 , 30 - 2 are similarly embedded within concave channels 18 longitudinally coextensive with the optical fibers.
Example
Cable Fabrication Process
The fabrication of composite fiber optic cable structures in accordance with this invention may utilize a process of coextrusion, in which the conductive wires, jacket material, aramid fiber and coated optical fiber are extruded together. Alternatively, a continuous strip of conductive foil or ink can be applied to the cable through a hot stamping process similar to that utilized to print identifiers onto the cable jacket. Hot stamping is a process whereby a stamping die is heated and forced against the cable jacket with a conductive material sandwiched in between. The material may be in the form of ink or foil, which is left behind in the regions where the heated die contacts the cable. The stamping temperature is typically between 100 and 205 degrees C. and the stamping pressure is typically between 0-6 bar.
In an alternate example, thermoplastic or “hot-melt” adhesive may be applied to the cable jacket by coating, spraying or laminating with a dry film adhesive or a thermoplastic filament. For example, a fusible monofilament comprised of low melt co-polyamide (nylon) or co-polyester (polyester) may be melted within the concave channel(s) to provide an adhesive cavity in which the conductive elements can be subsequently bonded by application of pressure and heat. Such fusible yarns and monofilaments are produced to melt at between 60 degrees C. and 160 degrees C. For example, Emser Industries supplies low temperature meltable Nylon yarn. Alternatively, a dry film adhesive with or without a backing can be selected to bond a metallic material such as copper or aluminum to PVC. 3M™ bonding film 406 is an example of a flexible, light-colored, thermoplastic adhesive bonding film.
In an alternate embodiment, the tone traceable cable is produced by bonding one or two wires within the cable groove(s) using a low viscosity (<5 cps) cyanoacrylate adhesive which is dispensed by an in-line system while the bulk cable is feed through at high speed. Suitable adhesive has a typical cure time of 1-10 seconds and can be accelerated by maintaining an elevated humidity level in the vicinity of the cable reel. A sufficiently small amount of adhesive is dispensed to prevent it from entirely covering the thin conductive element, e.g., 36 to 40 gauge copper wire. The adhesive's viscosity is sufficiently low that the adhesive preferentially wicks between the wire and the cable jacket, leaving a longitudinally extended portion of the copper wire exposed and free of adhesive.
Those skilled in the art will readily observe that numerous modifications and alterations of the device 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.
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Composite fiber optic cables having exposed, conductive traces external to the cable jacket enable non-invasive, wireless electrical tone tracing of fiber optic cables. The cross sectional geometry of the fiber optic cable prevents conductive traces from short circuiting when abutting other cables or grounded conductive elements. Moreover, the structure allows convenient electrical contact to the conductive traces at any location along the longitudinal extent of the cable without requiring penetration of the cable jacket or removal of fiber optic connectors. Traceable fiber optic cables of various types are disclosed, including simplex, duplex and ribbon cables. Systems of traceable cables utilizing connectors with integrated electrical antenna elements attached to the conductive elements of cable and RFID tags for remote connector port identification are further disclosed.
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TECHNICAL FIELD
[0001] The present invention relates to a metal recovery technique for simply recovering metals from batteries.
BACKGROUND ART
[0002] Recently, with the development of the portability of electronic devices, the number of rechargeable batteries used has been steeply increased. In addition to devices consuming relatively smaller electric power such as cellular phones and portable music players, the scope of the application of rechargeable batteries has been widened to also cover instruments requiring high output power such as electric tools, electric bicycles and electric vehicles; thus, the lithium ion batteries capable of obtaining high energy density have been attracting attention. The increased application to high output power instruments has enhanced the necessity of recovering valuable substances from spent batteries, and there have been proposed various techniques to recover valuable metals from lithium ion batteries.
[0003] For example, Non Patent Literature 1 features the techniques for recycling lithium ion batteries, and systematically describes the methods for recovering valuable metals constituting lithium ion batteries. According to the typical recycling methods published in Non Patent Literature 1, for example, spent lithium ion batteries are subjected to mechanical separating such as unsealing, dismantling and shredding, then valuable metals are leached by acid leaching, and from the acid-leached metals, each of the components is separated and made to form precipitates by taking advantage of the differences between the solubility properties of the desired components, or alternatively, each of the desired components is separated and recovered by applying processing such as preferential solvent extraction of each of the desired components.
[0004] Patent Literature 1 also discloses a technique to recover copper and cobalt by using a leached solution of valuable metals obtained by acid leaching as a catholyte, and by applying diaphragm electrolysis method with a cation exchange membrane as the diaphragm.
CITATION LIST
Patent Literature
[0005] Patent Literature 1: Japanese Patent No. 3675392
[0006] Patent Literature 2: Japanese Patent No. 3980526
[0007] Patent Literature 3: JP-A-11-292533
Non-Patent Literature
[0008] Non Patent Literature 1: Jinqiu Xu et al., “A review of processes and technologies for the recycling of lithium-ion secondary batteries,” Journal of Power Sources, vol. 177, pp. 512 to 527 (2008)
SUMMARY OF INVENTION
Technical Problem
[0009] Non Patent Literature 1 aims at, with the aid of various contrivances, the establishment of compatibility between the improvement of the yield of valuable substances and the achievement of high purities of the recovered substances; however, there is a large room for improvement in the fact that the steps involved are cumbersome and a huge equipment investment is required for the processing of a large amount of waste batteries.
[0010] In Patent Literature 1, specifically, an apparatus (a diaphragm electrolysis tank shown in FIG. 2 of Patent Literature 1) utilizing the ion selectivity possessed by a cation exchange membrane and a diffusion dialysis apparatus (not shown) utilizing the anion selective properties of an anion selective membrane are used. In a more specific description, the main valuable metals can be recovered by the following series of processings: the electrodeposition recovery of copper by diaphragm electrolysis→pH control→the electrodeposition recovery of cobalt by diaphragm electrolysis→pH control→the precipitation recovery of Fe(OH) 3 and Al(OH) 3 →the recovery of Li 2 CO 3 by addition of a carbonate. According to this technique, copper (divalent ion) and cobalt (trivalent ion) are electrochemically reduced to recover copper and cobalt, and hence high purity metals can be obtained; however, there is a room for improvement in the fact that when a large amount of waste batteries are processed, it is necessary to apply a huge quantity of electricity.
[0011] For example, the recovery of about 100 kg of cobalt requires a continuous flow of an electric current of 1 ampere for 100 hours, and preceding the recover of cobalt, a nearly the same quantity of electricity is applied in the electrodeposition of copper, hence the recovery of all the metals only by diaphragm electrolysis requires unexpected time and labor. Further, the multiple stages of pH control increase the liquid quantity at every stage, and hence when Li 2 CO 3 is recovered at the final stage of the series of processings, the Li concentration is decreased and even the addition of a carbonate does not necessarily leads to the increase of the Li yield. This is because the saturated solubility of lithium carbonate is as high as 1.3 wt % at 20° C., and hence the amount of unrecovered component is increased with the increase of liquid quantity. In order to avoid such a situation, it is necessary to add a process such as a concentration step. Further, Fe(OH) 3 and Al(OH) 3 each have a tendency to be gelated in a weakly acidic to neutral aqueous solution, and hence the operation in the step of filtrating recovery of Fe(OH) 3 and Al(OH) 3 on the basis of the technique of Patent Literature 1 is not easy. On the other hand, the dilution of the solution for facilitation of the filtration operation results in a decrease of the Li yield. Since the surface of the gel-like precipitation of Fe(OH) 3 or Al(OH) 3 has a characteristic of absorbing Li ion, also from the viewpoint of this absorption, it is difficult to significantly improve the Li yield.
Solution to Problem
[0012] The outline of a representative aspect of the invention disclosed in the present application can be briefly described as follows.
[0013] The present invention is characterized in that lithium is selectively leached from the cathode material containing lithium and transition metals, and the leaching is terminated while the ratio of the leached amount of lithium to the leached amount of cobalt is large.
Advantageous Effect of Invention
[0014] According to the present invention, a method for recovering lithium in a simple and easy manner and highly efficiently from lithium ion batteries can be provided.
BRIEF DESCRIPTION OF DRAWINGS
[0015] FIG. 1 is a table showing compositions of the leaching liquids according to Examples of the present invention and the Li/Co ratios obtained with the leaching liquids.
[0016] FIG. 2 is a schematic flow chart of the steps of recovering valuable metals in Example 1 according to the present invention.
[0017] FIG. 3 is a table showing the examples of the concentration ratio of lithium ion to sulfuric acid in the acid leaching treatment.
[0018] FIG. 4 is a schematic flow chart of the steps of recovering valuable metals in Example 2 according to the present invention.
DESCRIPTION OF EMBODIMENTS
[0019] Hereinafter, the embodiments for implementing the present invention are described. When they are described with reference to the accompanying drawings, the description is made by denoting with a symbol each of the members constituting the drawings; however, when functions are the same, sometimes the symbols and description may be omitted. The dimensions of the members shown in the drawings are sometimes not necessarily proportional to the actual dimensions of the members.
EXAMPLE 1
[0020] The outline of the method for recovering valuable metals of present Example is described with reference to FIG. 2 . FIG. 2 is a schematic flow chart of the steps of recovering valuable metals from waste lithium batteries (hereinafter, waste batteries) in present Example. First, the individual constituent members obtained by dismantling the waste batteries (S 101 ) are sorted according to the types of the individual members (S 102 ), and only the electrode active material containing valuable metals in high concentrations is extracted. The electrode active material thus extracted is treated with a Li-selective leachate (Li-selective leaching; S 103 ) to yield a Li-leaching solution. The Li-leaching solution and the non-leached fraction are subjected to solid-liquid separation (S 104 ). Mixing of a carbonate with the solution A containing Li (S 105 ) enables the recovery of Li as Li 2 CO 3 (S 106 ). The B (S 107 ) in which transition metals are relatively concentrated is still a solid. Then the B is subjected to acid dissolution and the pH of the resulting solution is adjusted. By such simple operations, transition metals are precipitated and sedimented as hydroxides, and these hydroxides are recovered by filtration (S 108 ). Such a series of operations enable the valuable metals and the excessive acid to be respectively recovered.
[0021] Hereinafter, according to the steps shown in FIG. 2 , the flow of the recovery of valuable metals is described in more detail.
[0022] The recovery of valuable metals from waste batteries first requires the dismantling of the batteries, however, before the dismantling, the batteries are discharged because charge may remain stored in the batteries. In present Example, the charge remaining stored in the batteries are discharged by soaking the batteries in an electrolyte-containing conductive liquid.
[0023] This discharge operation enables the Li ions scattered in each of the batteries to be concentrated within the cathode active material, and enables the Li yield to be maximized. By ensuring the condition in which Li is incorporated into a specific crystal structure, the Li selectivity is maximized. When the cathode active material is LiCoO 2 , the completely charged condition is said to be Li 0.4 CoO 2 and the completely discharged condition is said to be LiCoO 2 , so that the omission of the discharge treatment results in a risk of the Li recovery loss of at most about 60%. Needless to say, the discharge provides an advantage capable of ensuring the safety.
[0024] In present Example, as the electrolyte-containing conductive liquid, a sulfuric acid/y-butyrolactone mixed solution was used. In the mixed solution, sulfuric acid acts as an electrolyte, and hence by regulating the sulfuric acid concentration, the electroconductivity (reciprocal of resistance value) can be regulated. In present Example, the electric resistance between the right end and the left end of the electrolysis tank was actually measured to be 100 kΩ. A too small resistance of the solution leads to a risk of a too rapidly proceeding discharge, and on the contrary, a too large resistance leads to degradation of practicability because of too long discharge time. In present Example, it is preferable that the solution resistance falls within a range from about 1 k to 1000 kΩ, and the electrolyte concentration may be regulated so that the solution resistance falls within this resistance range.
[0025] The waste batteries of present Example include, for example, in addition to so-called spent batteries in which the predetermined limit of the charge-discharge cycle number is reached and the charging capacities are completely decreased, the pre-products occurring due to the failures in the battery production steps, and older-type clearance products in stock occurring due to product specification changes.
[0026] In S 101 , the waste batteries subjected to discharge treatment are dismantled. By using appropriate methods, the battery constituent members such as cases, packings and safety valves, circuit elements, spacers, current collectors, separators, cathode and anode electrode active materials are dismantled and separated according to the types of the individual members.
[0027] The interior of the waste batteries is often filled with gas to be in a pressurized condition, and hence, needless to say, consideration of safety in operation is necessary. In the present Example, the waste batteries were elutriated while the waste batteries are being soaked and cooled in the electrolyte-containing conductive liquid. The adoption of the elutriation under cooling enabled the fragmentation to be safely performed without scattering the gas filled in the interior of the batteries in the air.
[0028] In order to promote the exfoliation of the cathode active material and the anode active material coated and formed on the surfaces of the current collector from each of the current collector surfaces, the regulation of the composition of the electrolyte-containing conductive liquid is permissible. In the conductive liquid used in the discharge step, the conductivity is the property to be noted, and in the conductive liquid used in the elutriation step, the viscosity and the dielectric constant are the properties to be noted. The discharge step and the elutriation step are different in the required specifications, and hence the composition of the conductive liquid may be changed according to the steps. However, in such a case, two or more types of conductive liquids are required to be prepared. In the present Example, from the viewpoint of simplification and suppression of time and labor, and cost, the compositions of these conductive liquids were set to be the same.
[0029] Examples of the elutriation methods usable in the present Example include, without necessarily being limited to, a method using a ball mill. By omitting the roasting step before the shredding is performed, lithium cobalt oxide and polyvinylidene fluoride (PVFD) serving as a binder are not mixed with each other, and lithium and cobalt can be recovered with satisfactory purities. This is because the roasting step decomposes PVDF and generates a fluorine-containing compound to make the cathode material be water repellent. The cathode material made to be water repellent affects the below-described lithium extraction step. The waste batteries are fragmented under the conditions that the electrode active material of the cathode (hereinafter, the cathode active material) and the electrode active material of the anode (hereinafter, the anode active material) are preferentially fragmented among the constituent members such as cases, packings and safety valves, circuit elements, spacers, current collectors, separators and electrode active materials, then the resulting shredded matter is subjected to sieving. In this way, the cathode active material and the anode active material are separated and recovered under the sieve, and the rest of the shredded matter is separated and recovered on the sieve (S 102 ).
[0030] Although sieving is applied in the present Example, elutriation is applied at the very start, so that the slurry obtained by the elutriation can also be filtrated for separation by using a comparatively coarse filter. By introducing a continuous processing involving the operations from the elutriation to the filtration, the yield may also be improved. The members such as cases, packings and safety valves, current collectors (aluminum foil, copper foil) are larger in deferred malleability than the cathode active material (typically, LiCoO 2 ) and the anode active material (typically graphite), and accordingly also larger in strength at fracture. Because of this property, the fragmented matter of the electrode active materials is smaller in size than the fragmented matters obtained from the members other than the electrode active materials, and consequently, the electrode active materials can be easily separated and recovered by sieving or filtrating.
[0031] The matter under the sieve obtained by the foregoing treatment is subjected to the leaching treatment (S 103 ).
[0032] The leaching liquids used in present Example are shown as examples in FIG. 1 . The cathode active material of the waste batteries used in the present Examples is a lithium compound mainly composed of LiCoO 2 , and may include the cathode active materials having other compositions including, for example, iron phosphate, nickel and manganese.
[0033] As the mineral acid usable in the present Example, an acid solution prepared by adding hydrogen peroxide aqueous solution as an oxidation-reduction control agent to concentrated sulfuric acid (90% to 98%) is used. Those mineral acids that contain the alkali metals (sodium, potassium, rubidium and cesium) other than lithium, difficult to be separated from lithium, are not to be used. In consideration of, for example, the type and composition of the lithium compound, the treatment amount and the cost, the mineral acids to be used can be appropriately selected.
[0034] In the acid leaching treatment, it is understood that H 2 SO 4 , LiCoO 2 and H 2 O 2 are allowed to react with each other to produce Li 2 SO 4 , CoO and CoSO 4 . This reaction is divided into two stages. In the first stage, while the crystal structure is being maintained, the lithium ion in the cathode material and the proton in the solution are exchanged. In the second stage, the crystal structure starts to collapse due to the increase of the amount of lithium eluted from the crystal structure of the cathode material. In this case, the ion elution behavior is changed and the elution of cobalt ion is also made easy. Accordingly, it is important that lithium is dissolved before the collapse of the crystal structure and the dissolution reaction is terminated before the crystal structure collapses and the amount of the elution of cobalt becomes large.
[0035] In the present Example, when sulfuric acid and hydrogen peroxide are allowed to react with the cathode material, first lithium ion leaches into the solution due to the easiness in reaction based on the reaction energy, and subsequently, cobalt ion leaches. When the leaching treatment is terminated after lithium ion leaches and before cobalt ion leaches, a selective acid dissolution can be performed in such a way that the lithium ion concentration is higher relative to the cobalt ion concentration. In the present Example, the selective acid leaching is performed by controlling the reaction conditions of the Li selective leaching step, and the leaching is terminated within a reaction percentage range of the lithium ion of at most 80% or less (the residual proportion is 20% or more). Practically, in consideration of errors, when the leaching treatment is terminated preferably at a reaction percentage of about 70 to 75% (the residual proportion is 25 to 30%), the elution of cobalt can be suppressed. Reaction percentages exceeding 80% enhance the risk of the degradation of the selection ratio in the Li selective leaching reaction, and reaction percentages lower than 70% decrease the yield to impair the economic efficiency.
[0036] The acid leaching treatment is performed at a temperature of 50° C. or lower. The action of sulfuric acid allows lithium ion to leach as lithium sulfate (Li 2 SO 4 ), and cobalt ion to leach as cobalt sulfate (CoSO 4 ). The activation energy for lithium ion to leach is remarkably smaller than the activation energy for cobalt ion to leach, and consequently, the lithium ion leaches in advance of the cobalt ion. This reaction selectivity appears more remarkably at lower temperatures. This is because at higher temperatures, the thermal energy is abundant and the effect of the magnitude of the activation energy on the reaction selectivity is smaller.
[0037] Since the solubility of lithium sulfate is increased with the decrease of the temperature and the solubility of cobalt sulfate is increased with the increase of the temperature, by performing the treatment at a low temperature of 50° C. or lower, the selective dissolution of lithium can be enhanced. This is because when the dissolution amount of cobalt sulfate is small, the leaching amount of the cobalt ion forming cobalt sulfate is also small. In addition, since the dissolution rate of the ion is slow, the lithium ion which tends to be dissolved stably can be dissolved in advance of the cobalt ion.
[0038] The sulfuric acid to be used is preferably concentrated sulfuric acid (90% or more). Diluted sulfuric acid acts as a strong acid, and dissolves both lithium and cobalt at fast rates. On the other hand, when concentrated sulfuric acid is used, the content of isolated acid is small so that it does not act as a strong acid. Consequently, when concentrated sulfuric acid is used (also when the 90% sulfuric acid is diluted to some extent), the concentrated sulfuric acid does not act as a strong acid as the diluted sulfuric acid, and hence the dissolution rate of the metal ion becomes slow to facilitate the control of the dissolution rates of lithium and cobalt.
[0039] Even when diluted sulfuric acid is used, the dissolution amount of cobalt sulfate, which has a sulfate ion, becomes small in a solution having a small pH to enhance the lithium ion selectivity. In particular, it is preferable to regulate the concentration and amount of sulfuric acid and the addition amount of lithium in such a way that the concentration ratio of lithium ion to sulfuric acid is 7 or less during the acid leaching treatment. This is because such a concentration ratio range allows the selective solubility to be high. FIG. 3 shows the examples of the concentration ratio of lithium ion to sulfuric acid during the acid leaching treatment. As in Comparative Example 1 (Patent Literature 2) and Comparative Example 2 (Patent Literature 3), in the case where the concentration ratio of lithium ion to sulfuric acid during the acid leaching treatment is an incomparably larger value as compared to the present Example, the Li/Co ratio takes a low value.
[0040] Hydrogen peroxide is used as an oxidation-reduction control agent for regulating the electric potential in the acid solution, increased by the dissolution. This is because the electric potential falling out of the predetermined range affects the selective solubility.
[0041] When the leaching step is performed without performing the roasting step in the battery dismantling, it is possible to avoid the situation in which the surface of the cathode material is made to repel water as described above by the substance due to PVDF serving as the binder and the selective dissolution does not occur.
[0042] In the present Example, FIG. 1 shows Li/Co concentration ratios of the acid leachates obtained by dismantling spent lithium ion batteries for use in digital cameras. The spent lithium ion battery was processed as follows.
[0043] First, the waste lithium ion battery was subjected to the shredding process and the sieving process to beforehand remove the members such as a case, packing and safety valve, circuit elements, separators and current collectors, and then the valuable metals constituting the lithium ion battery were subjected to acid leaching (dissolving) by using mineral acids. The Li-selective leaching liquids used in the present Example are shown in FIG. 1 . The resulting leachate was stirred at room temperature for 1 hour, subjected to centrifugal separation with a centrifuge separator at 15000 rpm, at 20° C. for 15 minutes, thus a supernatant and a residue were separated to terminate the leaching reaction, and the supernatant was recovered.
[0044] In the present Example, the centrifugal separation was adopted as the solid-liquid separation to simply terminate the Li leaching reaction from the cathode active material such as lithium cobalt oxide.
[0045] As the acid used in the leaching liquid, nitric acid, sulfuric acid and hydrochloric acid were used. To these acids, the oxidation-reduction control agent such as methanol or hydrogen peroxide was added. The addition of the oxidation-reduction control agent provides an effect to stabilize the acid leaching and the effect to increase the recovery amount. The leaching time is preferably at the longest 2 hours or less and more preferably about 1 hour. The leaching for a short time significantly less than 1 hour, for example, 15 minutes tends to give a small yield. The crystal structure of the cathode active material from which lithium ion has been removed by leaching is not stable against a strong acid, and accordingly when a leaching treatment for a long time exceeding 2 hours is performed, the crystal of the cathode active material collapses to start the leaching of cobalt. Consequently, the Li selectivity in the acid leaching reaction is degraded. In addition, sufficient attention is paid so that the leaching liquid temperature may not reach the leaching liquid temperature of 80° C. to 90° C. adopted in the nonselective leaching (complete leaching) described in Non Patent Literature 1. In the present Example, the leaching liquid temperature is most preferably room temperature (15° C. to 30° C.), and the highest acceptable temperature is 50° C. or lower. When the leaching liquid temperature significantly exceeded 50° C., the Li selectivity tended to be degraded in the leaching reaction.
[0046] FIG. 1 shows results obtained by performing the leaching reaction under respective dissolution conditions at 20° C. (exclusive of the case of hot water) for 1 hour. As shown in FIG. 1 , in the case where the cathode material (LiCoO 2 ) was completely leached (complete dissolution), the Li/Co concentration ratio of the acid leachate was about 0.2. When the acid leaching liquid was composed only of sulfuric acid, the Li/Co concentration ratio was about 1.2, and when the acid leaching liquid was composed only of nitric acid, the Li/Co concentration ratio was about 0.8. When the acid leaching was performed with the acid leaching liquid having a composition of sulfuric acid:hydrogen peroxide=1:1, the Li/Co concentration ratio was about 1.7. In the recovery solution (A) obtained by the selective leaching, in addition to Li, the acid added excessively at the time of the acid leaching is simultaneously recovered.
[0047] In the present Example, the residue left after the completion of the leaching treatment is composed of the transition metal component of the anode active material and the cathode active material. The acidic solution, the anode active material and the cathode active material can be easily separated from each other by taking advantage of the different specific gravities thereof ((S 104 ) in FIG. 2 ). Specifically, these can be separated from each other by performing centrifugal separation of the leachate. In the present Example, although the separation and recovery were performed by adopting centrifugal separation and treating at 15000 rpm for 15 minutes, a more larger frequencies of rotation facilitates the mutual separation of the supernatant acidic solution (recovery solution, Li), the anode active material (C: carbon) and the cathode active material (Co). As a method for separating and recovering other than by taking advantage of the specific gravity difference, by filtrating the leachate, the leachate can be separated into the supernatant and the residue (the anode active material and the cathode active material) to be recovered. In this case, a step of further separating the residue into the anode active material and the cathode active material is to be performed.
[0048] The Li-containing supernatant may be subjected to further separation of lithium and cobalt by performing the treatments such as a diffusion dialysis treatment or a pressure dialysis treatment using an anion exchange resin, and an ion exchange resin treatment, each alone or in combinations, or in multi-stages,. Alternatively, lithium and cobalt can be further separated, for example, by using a dialysis treatment using an anion permselective membrane, a solvent extraction method or an acid retardation method. Although various methods can be used for the purpose of separating and recovering each of the elements from these residual solutions, a diaphragm electrolysis method, a recovery of hydroxide precipitation by neutralization (pH=6 to 9) and a combination of these methods can be used. By performing these methods, the Li/Co concentration ratio can be further enhanced.
[0049] High-purity lithium can be recovered (S 105 ) by neutralizing the recovery solution (A) having a large content proportion of lithium obtained as described above with a carbonate containing no sodium.
[0050] Specifically, lithium can be recovered by precipitation as lithium carbonate by adding calcium carbonate or a carbonate containing no sodium. Additionally, for example, there is a method in which CO 2 gas is made to blow in while the electrodialysis is being performed. In the present Example, the transition metal component (B) can be separated and recovered from the Li-containing solution (A) by the centrifugal separation step taking advantage of the specific gravity difference (S 106 ).
[0051] On the other hand, in the recovery of Co from the acid leachate in which Co was selectively separated, first, from the fraction separated in S 104 , the cathode active material is recovered (S 107 ). Then, the cathode material is soaked in an acidic solution and cobalt ion is leached (or eluted). To the solution in which cobalt ion is leached, a precipitation recovery method in which cobalt is precipitated and recovered as hydroxide by pH control can be used (S 108 ). For the purpose of separating and recovering each of the metals in the transition metal component (B), the transition metal component (B) is dissolved in an acid, then by a treatment utilizing the solubility property difference between the hydroxides of the individual metal elements, basically by repeating a cycle of pH control and recovery by precipitation, each of the transition metal elements can be separated and recovered. When the cathode active material contains lithium compounds other than LiCoO 2 , specifically, when the cathode active material is LiNiO 2 , LiMnO 2 , Li(Ni 1/3 Co 1/3 Mn 1/3 )O 2 , or one of olivine-based cathode materials such as LiCoPO 4 , LiFePO 4 , LiCoPO 4 F and LiFePO 4 F, Co, Ni, Mn and Fe can be separated as hydroxides and recovered by precipitation by the pH control of the solution.
EXAMPLE 2
[0052] FIG. 4 shows a flow chart of the metal recovery method in Example 2.
[0053] S 201 and 5202 are the same as S 101 and S 102 in Example 1, respectively. In S 203 , the cathode material is subjected to acid leaching in the same manner as in Example 1, and then the resulting leachate is separated into a supernatant and a residue. The supernatant is an acidic solution in which lithium ion and cobalt ion are leached and the Li/Co ratio is high, and the residue is the cathode active material left after the leaching of the anode active material and ions. By using a method such as centrifugal separation or filtration, these are separated into the supernatant and the residue.
[0054] In S 204 , by further dissolving the residue in an acidic solution, the cobalt and lithium contained in the cathode active material in the residue are ionized and dissolved in an acidic solution. Here, since the targets are the cobalt and lithium, anode active materials composed of carbon may be removed before the dissolution, and only the cathode active material may be dissolved. Thus, an acidic solution having a low Li/Co ratio is produced.
[0055] In S 205 , the lithium ion and the cobalt ion in the supernatant obtained in S 203 are separated. Examples of the separation method include the following.
[0056] By using an anion permselective membrane (dialysis membrane), lithium ion and cobalt ion can be separated. The anion permselective membrane is a membrane allowing anions to permeate, however, although lithium ion is a cation, a phenomenon occurs in which lithium ion permeates the anion permselective membrane. Consequently, when the acidic solution in which ions were leached in S 203 is made to flow on one side of the anion permselective membrane, and a recovery liquid (for example, pure water) for recovering lithium ion is made to flow on the other side, lithium ion permeates the dialysis membrane and transfers from the acidic solution into the recovery liquid. In this case, cobalt ion does not permeate the dialysis membrane and stays in the acidic solution. In this way, the lithium ion can be separated into the recovery liquid, and the cobalt ion can be separated in the acidic solution.
[0057] Additionally, by using an ion exchange resin, the lithium ion and the cobalt ion can be separated. The acid retardation is known in which when an acidic solution is made to pass through the ion-exchange resin, first a salt of the acid is eluted, and subsequently the acid is eluted. In this case, when the lithium ion and the cobalt ion are contained as the salts of the acid, first the cobalt ion is eluted and subsequently the lithium ion is eluted, and finally the acid is eluted. When the eluted liquid is divided as a function of time, the solution eluted first is large in the cobalt ion concentration, the solution eluted subsequently is large in the lithium ion concentration, and thus, the lithium ion and the cobalt ion can be separated.
[0058] In this way, the supernatant can be separated into the Li concentrated solution having a high Li/Co concentration ratio and the Co concentrated solution having a low Li/Co concentration ratio.
[0059] In S 206 , the lithium ion and cobalt ion in the acidic solution obtained in S 204 are separated, and the Li concentrated solution and the Co concentrated solution are obtained. As the separation method, the same method as in S 205 can be applied.
[0060] In S 207 , the Li concentrated solutions obtained in S 204 and 205 are recovered. In S 208 , by the same method as in S 106 , lithium is recovered from the Li concentrated solution.
[0061] In S 209 , the Co concentrated solutions obtained in S 204 and 205 are recovered. In S 208 , by the same method as in S 108 , lithium is recovered from the Li concentrated solution.
[0062] In Example 2, in this way, lithium and Co are recovered. As compared to Example 1, in addition to the step of separating lithium and Co, the obtained Li concentrated solution and the Co concentrated solution are respectively collected and recovered, and thus the yields of lithium and Co are improved.
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To provided a method for recovering lithium from a lithium ion battery using comparatively simple equipment and without using a cumbersome process. A lithium extraction method for extracting lithium from the positive electrode material of a lithium ion battery containing lithium and cobalt, the method being characterized in that the positive electrode material is immersed into an acidic solution at 50° C. or less, lithium ions are selectively leached into the acidic solution while inhibiting the leaching of cobalt ions, and the leaching of lithium ions is stopped while the amount of lithium contained in the positive electrode material is sufficient.
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This application is a continuation of application Ser. No. 10/554,367, filed Feb. 1, 2006 now U.S. Pat. No. 7,732,608, now allowed; which is a U.S. national stage under 35 U.S.C. 371 of Int'l Patent Application No. PCT/IN2004/000112 filed Apr. 22, 2004; which claims priority benefit of Indian Application No. 413/MUM/2003; the entire contents of all of which are hereby incorporated by reference in this application.
FIELD OF INVENTION
The present invention describes certain salts of Clopidogrel including their hydrates and other solvates, both in amorphous and crystalline forms, processes for their preparation and pharmaceutical compositions containing them and their use in medicine. Clopidogrel is marketed as (S)-(+)-Clopidogrel bisulfate, useful as an antiplatelet drug for the treatment of atherosclerosis, myocardial infarction, strokes and vascular death. The present invention also describes method of treatment of such cardiovascular disorders using the salts of the present invention or mixtures thereof, and pharmaceutical compositions containing them. The present invention also relates to the use of the salts of Clopidogrel disclosed herein and pharmaceutical compositions containing them for the treatment of cardiovascular disorders.
BACKGROUND TO THE INVENTION
The compounds of the invention referred herein, are pharmaceutically acceptable salts of the compound known by its generic name Clopidogrel having structure (I)
It is available in the market as its bisulfate salt and is marketed by Sanofi-Synthelabo as “Plavix” having the general formula (II)
Clopidogrel is an inhibitor of platelet aggregation and is marketed as an antianginal agent, antiplatelet agent and is found to decrease morbid events in people with established atherosclerotic cardiovascular disease and cerebrovascular diseases.
The therapeutic application of Clopidogrel as blood-platelet aggregation inhibiting agents and antithrombotic agent and its preparation is disclosed in U.S. Pat. No. 4,529,596. U.S. Pat. No. 4,847,265 describes the process for the preparation of the hydrogen sulfate salt of Clopidogrel.
Polymorphs of Clopidogrel bisulfate has been described in U.S. Pat. Nos. 6,504,040 and 6,429,210. We have disclosed novel polymorphs of Clopidogrel bisulfate in our PCT International Application No. PCT/IN03/00053.
The present applicant has also disclosed novel processes for preparing Clopidogrel base in U.S. Pat. No. 6,635,763.
U.S. Pat. No. 4,847,265 discloses that the dextrorotatory enantiomer of formula (I) of Clopidogrel has an excellent antiagregant platelet activity, whereas the corresponding levorotatory enantiomer of Formula (I) is less tolerated of the two enantiomers and is less active. U.S. Pat. No. 4,847,265 also describes various other salts of the compound of formula (I), like its hydrochloride, carboxylic acid and sulfonic acids salts. Specifically, salts of acetic, benzoic, fumaric, maleic, citric, tartaric, gentisic, methanesulfonic, ethanesulfonic, benzenesulfonic and, lauryl sulfonic acids were prepared. However, according to this patent, these salts usually precipitated in amorphous form and/or they were hygroscopic making them difficult to handle in an industrial scale. Also, no data corresponding to any of these salts are reported. The specification also describes salts of dobesilic acid (m.p.=70° C.) and para-toluenesulfonic acid, having a melting point of 51° C., the purification of which, as accepted in the patent, proved to be difficult.
Thus, there remains a need to prepare salts of Clopidogrel which are stable, easy to handle, can be purified and can be exploited on an industrial scale.
We hereby disclose certain pharmaceutically acceptable salts of Clopidogrel particularly the salts of p-toluenesulfonic acid, benzenesulfonic acid and methanesulfonic acids both in crystalline and amorphous forms, including their hydrates and other solvates which are well characterized, free flowing, easy to handle and having high purity.
OBJECTS OF THE INVENTION
It is therefore, an object of the present invention to prepare new pharmaceutically acceptable salts of Clopidogrel. More particularly, the present invention aims to provide new forms of Clopidogrel p-toluenesulfonate, Clopidogrel benzenesulfonate and Clopidogrel methanesulfonate, including their hydrates and other solvates in both crystalline and amorphous forms.
Another object of the present invention is to provide processes for preparing the new salts described herein.
A further object of the present invention is to provide the salts in pure, easy to handle, free flowing and stable form.
A further object is to provide a process of preparation of the pharmaceutically acceptable salts of the present invention on an industrial scale.
It is also an object of the present invention to provide for pharmaceutical compositions of the pharmaceutically acceptable salts of Clopidogrel of the present invention, as described herein.
Another object is to provide a method of treatment of cardiovascular disorders, comprising administering, for example, orally a composition containing the pharmaceutically acceptable salts of the present invention in a therapeutically effective amount.
SUMMARY OF THE INVENTION
The present invention describes certain pharmaceutically acceptable salts of Clopidogrel including their hydrates and other solvates, both in crystalline and amorphous forms, process for their preparation and pharmaceutical compositions containing them and their use in medicine. More particularly, the present invention describes new forms of Clopidogrel p-toluenesulfonate (or Clopidogrel tosylate), Clopidogrel benzenesulfonate (or Clopidogrel besylate) and Clopidogrel methanesulfonate (or Clopidogrel mesylate). Also described are processes for their preparation and pharmaceutical compositions containing the same and their use in medicine.
DESCRIPTION OF FIGURES
FIG. 1 : XRD of amorphous Clopidogrel besylate
FIG. 2 : XRD of crystalline Clopidogrel besylate
FIG. 3 : DSC of crystalline Clopidogrel besylate
FIG. 4 : XRD of amorphous Clopidogrel mesylate
FIG. 5 : XRD of amorphous Clopidogrel tosylate
DETAILED DESCRIPTION
The present invention provides certain pharmaceutically acceptable salts of Clopidogrel having the general formula (III) given below:
wherein R represents 4-methylphenyl, phenyl or a methyl group.
More particularly, the present invention describes stable forms of Clopidogrel p-toluenesulfonate, Clopidogrel benzenesulfonate and Clopidogrel methanesulfonate. These salts in their hydrated or other solvated forms is also encompassed within the present invention. The salts may be present either in crystalline or amorphous form. The salts may be prepared by reacting Clopidogrel base with the corresponding acids (p-toluenesulfonic acid, benzenesulfonic acid and methanesulfonic acid respectively) in a suitable solvent, at a temperature ranging from −30° C. to 50° C., and subsequently, removing the solvent. The suitable solvents can be water, methanol, ethanol, acetone, propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, dichloromethane, dimethyl formamide, dimethyl acetamide, 1,4-dioxane, tetrahydrofuran, ether, hexane, heptane, acetonitrile or mixtures thereof. The removal of the solvent can be done preferably at reduced pressure.
In a preferred embodiment, the Clopidogrel base may be prepared according to the processes disclosed in U.S. Pat. No. 6,635,763.
The salts may exist in a solvent-free form or it may be isolated as a hydrate or a solvate. The hydrates and solvates of the salts of the present invention form another aspect of the invention.
The salts can be characterized by suitable techniques known in the art.
The amorphous Clopidogrel p-toluene sulfonate (Clopidogrel tosylate) has a melting point in between the range of 70-95° C.
The amorphous Clopidogrel benzene sulfonate (Clopidogrel besylate) of the present invention has a melting point in between the range of 85° C.-95° C.
The crystalline Clopidogrel benzene sulfonate (Clopidogrel besylate) of the present invention has a melting point in between the range of 124° C.-132° C.
The amorphous Clopidogrel methane sulfonate (Clopidogrel mesylate) has a melting point of in between the range of 60° C.-70° C.
The following non-limiting examples illustrate the inventor's preferred methods for preparing the different salts of S(+) Clopidogrel discussed in the invention and should not be construed to limit the scope of the invention in any way.
EXAMPLE 1
Preparation of Clopidogrel Tosylate Amorphous Form
Clopidogrel base was dissolved in acetone to obtain a clear solution. To it was added p-toluene sulfonic acid at room temperature. The reaction mixture was heated to reflux temperature for 2 to 10 hrs. The solvent was evaporated to dryness under reduced pressure to obtain amorphous Clopidogrel tosylate.
m.p.: 75-93° C. (soften)
XRD: Amorphous
DSC: No melting peak
% water: 0.5-4% by weight (obtained in different batches).
EXAMPLE 2
Preparation of Clopidogrel Tosylate Amorphous Form
Clopidogrel base was dissolved in methanol to obtain a clear solution. To it was added p-toluenesulfonic acid at 20° C. The reaction mixture was heated to reflux temperature for 2 to 10 hrs. The solvent was evaporated to dryness under reduced pressure to obtain a powder.
m.p: 73-93° C. (soften)
XRD: Amorphous
DSC: No melting peak
% water: 0.5-4% by weight (obtained in different batches).
Similarly, the same salt was prepared using THF, acetonitrile and other similar solvents either alone or as a mixture of two or more solvents described elsewhere in the specification.
EXAMPLE 3
Preparation of Clopidogrel Tosylate Amorphous Form
Clopidogrel base was dissolved in methanol. p-Toluene sulphonic acid was added to the solution at 20° C. The reaction mixture was heated to reflux temperature for 2 hrs. The solution was cooled to room temperature and was added drop-wise to diethyl ether. The suspension was stirred at RT. The solid was filtered and dried at about 50° C. in a vacuum oven to give Clopidogrel tosylate similar to that obtained above.
Similarly, same salt was prepared using acetone, acetonitrile and other similar solvents either alone or as a mixture of two or more solvents described elsewhere in the specification.
EXAMPLE 4
Preparation of Clopidogrel Tosylate Amorphous Form
Clopidogrel base was dissolved in methanol, p-Toluene sulphonic acid was added to the solution at 20° C. The reaction mixture was heated to reflux temperature for 2 hrs. The solution was cooled to room temperature and the methanolic solution was added dropwise to hot toluene. The resulting solution was refluxed for an additional 20 minutes. The solution was cooled to room temperature and was stirred for 24 hrs. The solvent was evaporated under reduced pressure to dryness to obtain Clopidogrel tosylate, similar to that obtained above.
Similarly, the same salt was prepared using acetone, acetonitrile and other similar solvents either alone or as a mixture of two or more solvents described elsewhere in the specification.
EXPERIMENT 5
Preparation of Clopidogrel Besylate Amorphous Form
Clopidogrel base was dissolved in acetone to obtain a clear solution. Then benzenesulfonic acid was added to the solution at 20° C. The reaction mixture was heated to reflux temperature for 2 to 10 hrs. The solvent was evaporated to dryness under reduced pressure to obtain the title salt as a powder.
m.p: 86-95° C. (soften)
XRD: Amorphous
DSC: No melting peaks
% water: 0.5-4% by weight, (obtained in different batches).
EXAMPLE 6
Preparation of Clopidogrel Besylate Amorphous Form
Clopidogrel base was dissolved in methanol to obtain a clear solution. Benzenesulfonic acid was added to the solution at 20° C. The reaction mixture was heated to reflux temperature for 2 to 10 hrs. The solvent was evaporated to dryness under reduced pressure to obtain the title compound.
m.p.: 84-93° C. (soften)
XRD: Amorphous
DSC: No melting peak
% water: 0.5-4% by weight (obtained in different batches).
Similarly, the same salt was prepared in THF, acetonitrile and other similar solvents either alone or as a mixture of two or more solvents described elsewhere in the specification.
EXAMPLE 7
Preparation of Clopidogrel Besylate Amorphous Form
Clopidogrel base was dissolved in methanol. Benzene sulphonic acid was added to the solution at 20° C. The reaction mixture was heated to reflux temperature for 2 hrs. The solution was cooled to room temperature and was added drop-wise to diethyl ether. The suspension was stirred at RT. The solid was filtered and dried in a vacuum oven to give Clopidogrel besylate, similar to that obtained above.
Similarly, the same salt was prepared using acetone, acetonitrile and other similar solvents either alone or as a mixture of two or more solvents described elsewhere in the specification.
EXAMPLE 8
Preparation of Clopidogrel Besylate Amorphous Form
Clopidogrel base was dissolved in methanol. Benzene sulphonic acid was added to the solution at 20° C. The reaction mixture was heated to reflux temperature for 2 hrs. The solution was cooled to room temperature and the methanolic solution was added drop-wise to the boiling toluene. The resulting solution was refluxed for an additional 20 minutes. The solution was cooled to room temperature and was stirred at this temperature for extended hours. The solvent was evaporated under reduced pressure to dryness to obtain Clopidogrel besylate, similar to that obtained above.
Similarly, the same salt was prepared using acetone, acetonitrile and other similar solvents either alone or as a mixture of two or more solvents described elsewhere in the specification.
EXAMPLE 9
Preparation of Clopidogrel Besylate Crystalline Form
Clopidogrel besylate amorphous was stirred in diethyl ether at 20° C. The obtained white solid was collected by filtration, washed with diethyl ether and dried, in a vacuum oven to obtain Clopidogrel besylate in crystalline form.
m.p.: 126-130° C. (range obtained from different batches).
XRD: Crystalline
DSC: 127.5-132.9° C.
% water: 0.1-0.3% by weight (range obtained from different batches).
The above process for preparing clopidogrel besylate crystalline form, is carried out using different ethers wherein each alkyl radical of the ether is independently selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, 1-butyl, 2-butyl and t-butyl or mixtures thereof.
EXAMPLE 10
Preparation of Clopidogrel Besylate Crystalline Form
Clopidogrel besylate amorphous was stirred in n-heptane at 20° C. The obtained white solid was collected by filtration, washed with n-heptane, and dried in a vacuum oven to obtain clopidogrel besylate in crystalline form.
m.p: 125-130° C. (range obtained from different batches).
XRD: Crystalline
DSC: 125.5-130.9° C.
% water: 0.1-0.3% by weight (range obtained from different batches).
Similarly, Clopidogrel besylate crystalline form was prepared in hexane, n-heptane, cyclohexane, petroleum ether as solvents as well as their mixtures.
EXAMPLE 11
Preparation of Clopidogrel Besylate Crystalline Form
Clopidogrel base was dissolved in diethyl ether at 20-25° C. To this was added benzene sulphonic acid dissolved in diethyl ether. The reaction mixture was stirred at 25-30° C. for 24-30 hrs. The white solid was collected by filtration, washed with diethyl ether, and dried at 50-60° C. in a vacuum oven to obtain Clopidogrel besylate crystalline form.
m.p.: 124-130° C. (range obtained from different batches).
XRD: Crystalline
DSC: 128.9-132.7° C.
% water: 0.2%
The above process for preparing clopidogrel besylate crystalline form, is carried out using different ethers wherein each alkyl radical, of the ether is independently selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, 1-butyl, 2-butyl and t-butyl or mixtures thereof.
EXAMPLE 12
Preparation of Clopidogrel Mesylate Amorphous Form
Clopidogrel base was dissolved in acetone to obtain a clear solution. Methanesulfonic acid was added to the solution at 20° C. The reaction mixture was heated to reflux temperature for 2 to 10 hrs. The solvent was evaporated to dryness under reduced pressure to obtain the title compound.
m.p: 60-70° C. (soften)
XRD: Amorphous
DSC: No melting peak
% water: 0.5-4% by weight (obtained from different batches).
EXAMPLE 13
Preparation of Clopidogrel Mesylate Amorphous Form
Clopidogrel base was dissolved in methanol to obtain a clear solution. Methanesulfonic acid was added to the solution at 20° C. The reaction mixture was heated to reflux temperature for 2 to 10 hrs. The solvent was evaporated to dryness under reduced pressure to obtain the title compound.
m.p: 60-70° C. (soften)
XRD: Amorphous
DSC: No melting peak
% water: 0.5-4% by weight. (obtained from different batches).
Similarly, the same salt was prepared in THF, acetonitrile and other similar solvents either alone or as a mixture of two or more solvents described elsewhere in the specification.
All these salts are free flowing, easy to handle and can be manufactured in large scale as well as can be used in the preparation of suitable pharmaceutical compounds or dosage forms. The salts of the present invention may also exist as different solvates corresponding to the different solvents used in their preparation. Such obvious solvates are also intended to be encompassed within the scope of the present invention.
The salts of Clopidogrel drug substance of the present invention prepared according to any process described above or any other process can be administered to a person in need of it either without further formulation, or formulated into suitable formulations and dosage forms as are well known.
In another embodiment of the present invention a method of treatment and use of the pharmaceutically acceptable salts of Clopidogrel described in the present invention for the treatment of cardiovascular disorders & inhibiting platelet aggregation is provided, comprising administering, for example, orally or in any other suitable dosage forms, a composition containing the new salts of the present invention in a therapeutically effective amount.
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Disclosed are new salts of Clopidogrel viz. Clopidogrel mesylate, Clopidogrel besylate and Clopidogrel tosylate, methods for their preparation and pharmaceutical compositions containing them and their use in medicine.
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The present application claims the benefit of (priority to) U.S. Provisional Patent Application No. 61/212,165, filed Apr. 8, 2009, entitled, “Multiplex Tunable Filter Spectrometer,” by Saptari, the text of which is hereby incorporated herein by reference, in its entirety. Also incorporated herein by reference in its entirety is the text of International (PCT) Patent Application No. PCT/US09/41254, filed Apr. 21, 2009, and published on Feb. 4, 2010, as WO 2010/014277.
FIELD OF THE INVENTION
The invention relates generally to spectroscopic systems and spectrometers. More particularly, in certain embodiments, the invention relates to methods and systems for measuring and/or monitoring the chemical composition of a sample (e.g., a process stream), and/or detecting substances or compounds in a sample, using light spectroscopy. More particularly, in certain embodiments, the invention relates to a multiplex, wavelength-scanning, interference filter based optical spectrometer.
BACKGROUND OF THE INVENTION
Optical spectrometers are systems that enable the measurement of optical intensity at specific wavelengths or spectral bands. Optical spectrometers are used in some chemical or biological analysis devices or analyzers to detect, identify and/or quantify chemical or biological species. Absorption, Raman and fluorescence spectroscopy are some of the most common methods used to optically analyze chemical or biological samples. Several commonly used optical spectrometers today include Fourier-transform spectrometers (FTS), grating based spectrometers being the most common dispersive type of spectrometer, and filter based spectrometers that employ a linear variable filter (LVF)—e.g., as described in U.S. Pat. No. 5,166,755 to Gat; U.S. Pat. No. 5,218,473 to Seddon et. al.; and U.S. Pat. No. 6,057,925 to Anthon, the texts of which are incorporated herein by reference, in their entirety—and angularly tuned filter spectrometers—e.g., as described in U.S. Pat. No. 4,040,747 to Webster; U.S. Pat. No. 2,834,246 to Foskett; U.S. Pat. No. 5,268,745 to Goody; and U.S. Pat. No. 7,099,003 to Saptari, the texts of which are incorporated herein by reference, in their entirety.
Many chemical and biological analyses today require high sensitivity devices, measuring trace components very accurately and reproducibly, down to parts-per-million or even parts-per-billion levels. As such, optical spectrometers with high optical throughput or etendue are essential. Fourier transform spectrometers and angle-tuned filter spectrometers, in principle, can provide the required high optical throughput, whereas dispersive spectrometers provide relatively much lower throughput. In addition, many chemical and biological analyses require multiple and/or wide spectral or wavelength coverage due to the need to measure multiple species and/or the need to compensate for signal interferences arising from the presence of other species in the sample.
Although Fourier transform spectrometers can in principle provide high throughput or etendue capability, they require complex instrumentation, including high-precision optical components and subassemblies, and thus are relatively expensive and cumbersome to operate and maintain. Rotating filter spectrometers, such as those described in U.S. Pat. No. 4,040,747 to Webster; U.S. Pat. No. 5,268,745 to Goody; and U.S. Pat. No. 7,099,003 to Saptari, can provide as high throughput as Fourier transform spectrometers without the instrumentation complexity of the FTS. However, the tilting or rotating filter spectrometers provide rather limited wavelength coverage, for example, approximately, 1-5% of the nominal wavelength of the filter, corresponding to an effective angular scan distance of approximately 0-60 degrees, due to geometrical limitations (zero degree refers to zero degree of incident angle).
Systems employing a plurality of filters have been described and are reported to include additional wavelength bands and/or extend the wavelength coverage. See, e.g., U.S. Pat. No. 4,040,747 to Webster; and U.S. Pat. No. 7,099,003 to Saptari. However, such systems provide additional wavelength bands by adding filters that are scanned in series, i.e. one wavelength band is scanned at a time. With such systems, the number of wavelength bands that can be covered by the system is limited geometrically by the rotating assembly design. For example, with a single rotation axis and a single rotation assembly, the maximum practical number of filters, and thus wavelength bands, is three (e.g., see U.S. Pat. No. 4,040,747 to Webster; and U.S. Pat. No. 7,099,003 to Saptari). Additional bands may be achieved through the use of additional filter assemblies and/or axes of motion. However, such additions would further complicate the system instrumentation. In addition, such filter spectrometers do not exhibit the multiplex advantage of FTS, i.e. being able to measure the analysis wavelength bands simultaneously, which provides a further improved sensitivity performance. There is a need for a spectrometer that provides the multiplex advantage of FTS, with reduced instrumentation complexity.
SUMMARY OF THE INVENTION
Presented herein is a compact, rugged, inexpensive spectroscopic system well-suited for industrial applications. The system features a spectrometer that enables high etendue or high optical throughput spectroscopic measurement, wavelength band multiplexing capability, and reduced system complexity compared to FTS systems. The system may be used to perform spectroscopic determinations of chemical and/or biological media. For example, the system may be used to determine media composition, detect the presence or absence of certain species or analytes, determine the concentration of one or more species in a sample, and/or to verify sample quality and consistency with a known set of samples.
In preferred embodiments, the spectrometer features a rotatable or tiltable filter assembly comprising one or more multi-band optical bandpass interference filter(s). Because the moving filters have multiple wavelength bands, multiple wavelength sweeps can be performed simultaneously, providing improved sensitivity and versatility. Light that strikes a filter within the bandpass wavelength regions is transmitted through the filter, and the light outside the bandpass regions is reflected back. Through a rotary motion of the filter assembly, continuous wavelength sweeping within multiple wavelength regions is performed simultaneously. The rotary motion produces varying incident angle at which light strikes the surface of the filter module. The multi-band filter module may be constructed from multiple bandpass filters mechanically joined together. The multi-band filter module may alternatively be constructed from a single filter element specifically designed to transmit multiple bandpass regions.
In certain embodiments, the invention provides a spectroscopic system and method wherein selected wavelength-swept regions provide spectral analysis of the target chemical or biological species in a sample, as well as orthogonal analysis of spectral interferences arising from the background media or other existing or potentially existing species. In certain embodiments, some of wavelength-swept regions are selected to provide compensation for ambient and/or sample conditions such as temperature and pressure.
Multiple spectral features arising from interaction of the light with the target analytes may result in overlapping spectral features. In preferred embodiments, the spectrum of the individual target analyte is extracted or separated by using chemometrics such as multiple linear regression, principal components analysis or partial least squares.
In certain embodiments, the spectroscopic system of the present invention includes an electromagnetic radiation source (e.g., a light source), a detector for receiving light, and a filter based spectrometer. The light source may include a blackbody emitter, LED or SLED (super light-emitting diode) sources, a flashlamp, an arc lamp, or light emitted from natural sources such as the sun or other heat sources. The detector may include a photodiode, a thermal based detector such as pyroelectric detector, or a photomultiplier tube.
In one aspect, the invention is directed to a spectroscopic system including: (i) an optical filter module which includes one or more optical interference filters configured to receive electromagnetic radiation from an electromagnetic radiation source, the one or more filters having a plurality of multiplexed bandpass regions configured to simultaneously transmit multiple wavelength bands of electromagnetic radiation through the filter module; and (ii) an optical detector configured to receive the multiple wavelength bands of electromagnetic radiation transmitted through the filter module and to generate one or more electrical signals indicative of electromagnetic radiation intensity as a function of wavelength.
In certain embodiments, the filter module includes an interference filter comprising multiple bandpass regions. The filter module may also or alternatively include a plurality of interference filters which individually or collectively comprise multiple bandpass regions.
In certain embodiments, the optical filter module is configured to provide adjustment of the incident angle of the electromagnetic radiation from the electromagnetic radiation source onto the one or more optical filters. The optical filter module may include a rotatable filter assembly to provide the incident angle adjustment. The rotatable filter assembly may include a position detector to produce at least a first signal comprising a series of digital pulses corresponding to the angular position of the rotatable filter assembly. The position detector may be configured to clock analog-to-digital conversion. In certain embodiments, the rotatable filter assembly includes at least four multiplexed bandpass regions on a single rotatable filter assembly with a single rotation axis.
In certain embodiments, the spectroscopic system further includes a memory for storing code that defines a set of instructions (e.g., software); and a processor for executing the set of instructions to identify one or more species present in a sample from which the electromagnetic radiation emanates or through which the electromagnetic radiation passes prior to reception by the optical detector. The software may direct the processing of data corresponding to the electromagnetic radiation intensity measured by the detector over the multiple wavelength bands, thereby (i) identifying one or more species present in the sample, (ii) quantifying each of one or more species present in the sample (e.g., determining concentrations or densities), (iii) identifying the absence of one or more species for which the sample is tested, or (iv) any combination of the above.
In certain embodiments, the optical detector is configured to receive the multiple wavelength bands of electromagnetic radiation after transmission through both the filter module and a sample being measured. The system may further include a sample cell configured to contain a sample through which the electromagnetic radiation passes or from which the electromagnetic radiation emanates prior to reception by the optical detector. The sample cell may be located upstream or downstream of the optical filter module.
In certain embodiments, the optical detector, in conjunction with the optical filter module, is configured to generate one or more electrical signals indicative of electromagnetic radiation intensity over a sweep of wavelengths within each of the multiple wavelength bands.
In certain embodiments, the spectroscopic system further includes the electromagnetic radiation source. The electromagnetic radiation source may produce visible light, infrared light, near-infrared light, and/or ultraviolet light.
In another aspect, the invention is directed to a spectroscopic method for detecting and/or quantifying one or more species in a sample, the method comprising the steps of: (a) directing electromagnetic radiation from an electromagnetic radiation source into an optical filter module comprising one or more optical interference filters, the one or more optical filters comprising a plurality of multiplexed bandpass regions configured to transmit multiple wavelength bands of electromagnetic radiation through the filter module simultaneously; (b) directing the multiple wavelength bands of electromagnetic radiation through a sample comprising one or more species; (c) directing the multiple wavelength bands of electromagnetic radiation from the sample into an optical detector configured to generate one or more electrical signals indicative of electromagnetic radiation intensity over a sweep of wavelengths within each of the multiple wavelength bands; and (d) processing data corresponding to the one or more electrical signals to identify and/or quantify one or more species present in the sample.
Elements of embodiments described with respect to a given aspect of the invention may be used in various embodiments of another aspect of the invention. For example, elements of the various embodiments of the spectroscopic system described herein may be used in the spectroscopic method described herein, and vice versa.
BRIEF DESCRIPTION OF DRAWINGS
The objects and features of the invention can be better understood with reference to the drawings described below, and the claims. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the drawings, like numerals are used to indicate like parts throughout the various views.
FIG. 1 is an illustration of a tunable filter spectrometer using a rotating filter.
FIG. 2 is an illustration of a tunable filter spectrometer using a plurality of single-band rotating filters.
FIG. 3 is an illustration of a system block diagram of a spectrometer system, according to an illustrative embodiment of the invention.
FIG. 4A is a schematic illustration of a multiplex filter module comprising multiple bandpass filters, configured to mount in a plane and rotate on its center axis, according to an illustrative embodiment of the invention.
FIG. 4B is a graph showing spectroscopic data corresponding to each of the multiple bandpass filters of the multiple filter module of FIG. 4A , according to an illustrative embodiment of the invention.
FIG. 5A is a schematic illustration of a filter module comprising a single filter element producing multiple bandpass regions, according to an illustrative embodiment of the invention.
FIG. 5B is a graph showing spectroscopic data corresponding to each of the multiple bandpass regions of FIG. 5A , according to an illustrative embodiment of the invention.
FIG. 6A is a schematic illustration of a filter module comprising stacked filter elements, according to an illustrative embodiment of the invention.
FIG. 6B is a graph showing spectroscopic data corresponding to the multiple bandpass regions of the stacked filter elements of FIG. 6A , according to an illustrative embodiment of the invention.
FIG. 7 is a schematic drawing of a spectroscopic system and optical layout of a spectrometer, according to an illustrative embodiment of the invention.
FIG. 8 is a graph showing exemplary absorption spectra of CO2 and CH4 gases that may be obtained using a spectroscopic system with multiple bandpass regions, according to an illustrative embodiment of the invention.
FIGS. 9A and 9B are graphs showing individual gas sample spectra and the combined gas sample spectrum as measured by a multiplex filter spectrometer, according to an illustrative embodiment of the invention.
FIG. 10 is a block diagram of a CLS based processing algorithm, according to an illustrative embodiment of the invention.
FIG. 11A is a schematic drawing of a filter module of a prototype spectrometer, the filter module comprising a two-band filter that rotates about the axis shown, according to an illustrative embodiment of the invention.
FIG. 11B is a photograph of the filter module of FIG. 11A , according to an illustrative embodiment of the invention.
FIG. 12 is a graph showing an experimentally measured transmission spectrum using the filter module of FIGS. 11A , 11 B, according to an illustrative embodiment of the invention.
FIG. 13 is a graph showing an experimentally measured absorption spectrum using the filter module of FIGS. 11A , 11 B, according to an illustrative embodiment of the invention.
DETAILED DESCRIPTION
It is contemplated that methods, systems, and processes described herein encompass variations and adaptations developed using information from the embodiments described herein.
Throughout the description, where systems and apparatus are described as having, including, or comprising specific components, or where processes and methods are described as having, including, or comprising specific steps, it is contemplated that, additionally, there are systems and apparatus of the present invention that consist essentially of, or consist of, the recited components, and that there are processes and methods of the present invention that consist essentially of, or consist of, the recited processing steps.
The mention herein of any publication, for example, in the Background section, is not an admission that the publication serves as prior art with respect to any of the claims presented herein. The Background section is presented for purposes of clarity and is not meant as a description of prior art with respect to any claim.
Headers are used herein to aid the reader and are not meant to limit the interpretation of the subject matter described.
FIG. 1 is an illustration of a tunable filter spectrometer using a rotating filter 102 . The filter 102 rotates as shown as light 101 from a light source passes through the filter 103 , thereby shifting the wavelength 104 of the filter. FIG. 2 illustrates a tunable filter spectrometer using three single-band rotating filters, where the filter module 203 rotates as light 201 from a light source passes through the three filters of the filter module 203 , thereby shifting the wavelengths 204 , 205 , 206 of the filters. The wavelength bands are scanned in series, i.e. one wavelength band is scanned at a time. With such systems, the number of wavelength bands that can be covered by the system is limited geometrically by the rotating assembly design. For example, with a single rotation axis and a single rotation assembly, the maximum practical number of filters, and thus wavelength bands, is three.
FIG. 3 is a block diagram of hardware components of a spectroscopic system featuring a multi-band angle-tuned filter spectrometer, according to an illustrative embodiment of the invention. Starting from the left on the diagram, the system includes a light source 301 that contains the plurality of wavelengths to be analyzed. In the case of absorption measurement, the light source 301 would contain the wavelengths at which the sample is ‘active’ or absorbing light. The light source 301 may be a filament based or a light emitting diode source, for example. In the case of emission spectroscopic measurement such as Raman or fluorescence spectroscopy, the light source is the emitted light radiation from the sample. A collimating optics assembly 302 is generally needed to control the degree of collimation of the light prior to entering the filter assembly. The collimating optics assembly may include one or multiple lenses or mirrors and apertures. The filter assembly 303 comprises the multi-bandpass filter and its electro-mechanics used to control its angular motion. The motion may be a continuous rotation, a back-and-forth tilt or a step-scan motion covering the full angular distance needed. The amount of angular distance needed depends on the required wavelength scan range. The angular distance is generally between +/−30 degrees to +/−60 degrees, but values outside these bounds are possible. The sample cell 304 holds the sample to be analyzed, which may be in gaseous, liquid, slurry or solid form. The configuration as shown with the sample cell located downstream of the filter assembly is typical for an absorption measurement. In the case of emission measurement, such as Raman or fluorescence spectroscopy, the sample cell would be upstream of the filter assembly and the light source 301 in FIG. 3 would represent the light emitted from the sample itself. The focusing optics assembly 305 is configured to focus the light onto a photodetector 306 element, which generally needs to be made small to provide the required signal-to-noise ratio for quantitative analysis. The size of the detector's active area is generally on the order of 1 mm 2 or smaller, where the beam size is generally on the order ten millimeters or larger. The focusing optics 305 may include one or more lenses and/or mirrors. The function of the photo-detector 306 is to convert the light radiation into electrical signal. Different types of photo-detectors may be used, depending on the regions of the spectrum being analyzed. For example, in the visible region, silicon photo-detector is popularly used, whereas in the infrared region, Indium Gallium Arsenide (InGaAs), Indium Arsenide (InAs), Mercury Cadmium Telluride (MCT) and pyroelectric based detectors are available as options. The signal amplifier 307 amplifies and/or conditions the electrical output of the photo-detector 306 to the appropriate types and/or levels for input to the analog-to-digital converter (ADC) 308 . The digital signal processor (DSP) 309 contains an algorithm that speciates or decodes the encoded multi-band and multi-component spectra into the individual species components in the sample being analyzed. The DSP 309 may also contain an algorithm that computes the quantitative levels of the sample components. The DSP may be implemented on an external computer, on an on-board computer or on a fully embedded microprocessor. The DSP algorithm may be composed of various types of algorithms including least-squares based chemometrics such as classical least squares (CLS) or principal component analysis (PCA) in which the measured spectra are modeled or fitted against pre-established calibration spectra or other types of pattern recognition algorithm utilizing any of the spectral features. The output of the DSP, 310 , may include quantitative information of the sample components, whether it is in concentration, density or other appropriate measurement units depending on the application. The DSP output 310 may also contain other relevant measurement or system information such as system health indicators, measurement confidence levels and other auxiliary measurements such as sample pressure and temperature. The input/output interface 311 provides the necessary interfaces to transmit the measurement outputs to the user or to other machineries. In addition, the input/output interface may also connect with user input devices to provide the ability to make changes to configurable parameters such as update rate, signal averaging time and data logging parameters.
FIGS. 4A and 4B illustrate a filter assembly which allows for simultaneous multi-band or multiplexed wavelength scanning. In this particular embodiment, the filter module 402 is composed of four bandpass filters 403 , 404 , 405 and 406 , each transmitting a particular wavelength region, 407 , 408 , 409 and 410 respectively at zero incident angle between the light beam as illustrated by light ray 411 and the surface of the filter module. As the filter module 402 rotates about the rotation axis 401 away from zero incident angle, the bandpass region of each filter is shifted to a shorter wavelength as illustrated by diagram 412 . In certain embodiments, the incident angle is varied by continuous rotation of the filter module in a particular direction, either clockwise or anti-clockwise. In certain embodiments, the filter module is rotated back-and-forth periodically. In certain other embodiments, the filter module rotates in a step-and-scan mode, where it rotates to a certain angular position, stops, and collects data, and does this repetitively until the full angular distance is covered.
In certain embodiments, the filter module is composed of a single interference filter element that is specifically made to transmit more than one bandpass region. FIG. 5 shows an illustration of a custom interference filter 502 , which provides multiple bandpass regions. When rotated about axis 501 , the incident angle of the light beam 503 varies. As a result, each of the “n” bandpass functions shifts with respect to wavelength.
In certain embodiments, the filter module is composed of multiple stacked interference filters, with a combined effective transmission function comprising multiple bandpass regions, as illustrated in FIG. 6 . In this illustration, two filters 603 and 604 are stacked. Each filter has a transmission function comprising a bandpass and an edgepass (long-wave or short-wave pass transmission functions), as illustrated by diagrams 605 and 606 . The combined effective transmission function of the stacked filter module is illustrated by diagram 607 .
In certain embodiments, the filter module is composed of more than one multi-band filters rotated or tilted in series, creating a total of m×n band regions, where m is the number of the multi-band filters and n is the number of bands per filter. The number of bands on each filter does not necessarily have to be equal to each other. For example, a filter may contain two bands while another contains four. The purpose of this configuration would be to further increase the number of bands beyond what is practically achievable through the use of a single multi-band filter without any additional rotary axes. The practical limitations to the number of bands of a single filter include the filter design/fabrication complexity, manufacturing cost and reduction in the effective optical throughput per band.
FIG. 7 illustrates a hardware implementation of a system design utilizing three multi-band filters as its filter spectrometer assembly. The rotary assembly 701 comprises three multi-band filters 702 a , 702 b and 702 c . Each of the individual multi-band filters may be constructed from joined filters as illustrated in FIG. 4 , or may be a custom designed filter as illustrated in FIG. 5 , or may comprise stacked filters as illustrated in FIG. 6 . Filter shields 703 are used to block the light at certain potions of the rotation where part of the light is not incident on any of the filters, thereby preventing detector saturation. The light source assembly 704 may be made of various types of emitters including filament based emitters and LED emitters. In this design, a 90-degree parabolic mirror 705 is used to collimate the light and direct it to the filter assembly. The light beam is directed into the sample cell 707 by the 90-degree flat mirror 706 . Upon exiting the sample cell, the light beam is reflected at another 90-degree flat mirror 708 , which is then directed and focused by another parabolic mirror 709 onto a photo-detector 710 .
Non-limiting examples of approximate wavelength ranges for infrared filters that may be used with the spectroscopic systems described herein include the following: 2600-2720 nm for moisture and CO 2 analysis; 3250-3420 nm for hydrocarbon gas analysis; 4400-4720 nm for CO analysis; 1600-1780 nm for hydrocarbon gas analysis; and 1625-1800 nm for alcohol-water liquid analysis. Non-limiting examples of approximate wavelength ranges for UV filters that may be used with the spectroscopic systems described herein include the following: 180-210 nm for H 2 S analysis; and 200-230 nm for sulfur analysis in natural gas. A non-limiting example of an approximate wavelength range for visible light filters that may be used with the spectroscopic systems described herein is 750-780 nm for O 2 analysis.
The following constructive example illustrates the mechanism by which the spectrometer provides multiplexed spectral analysis. Consider the measurement of carbon dioxide (CO 2 ) gas and methane (CH 4 ) gas, two important compounds in pollution/environmental studies and combustion control and analysis. FIG. 8 shows the absorption spectra of CH4 ( 801 ) and CO 2 gases ( 802 ). The filter module is designed such that through the effective angular sweeping distance, the bandpass functions of the filter module sweep through the appropriate features of the gases. In this case, the filter module is designed such that it sweeps through bandpass regions within approximately 3100-3500 nm region for the CH4 analysis and 4100-4500 nm region for the CO 2 analysis as indicated by the shaded regions 803 and 804 respectively. An absorption spectrum of a mixture of the gases CO 2 and CH 4 analyzed by the spectrometer would result in a blended spectrum as simulated and illustrated in FIG. 9 , specifically in 902 . The graphs shown in 901 illustrate the simulated individual absorption spectra the spectrometer would generate, i.e. when pure gaseous sample of each compound enters the sample cell.
The determination of the number of analyzed wavelength bands and the specific locations of the bands is dependent upon the application or measurement criteria. The spectrometer system may be configured to include a particular wavelength band to enable measurement of the target compound that is active in that region. Following the measurement example above, the two wavelength bands 803 and 804 as shown in FIG. 8 are selected to enable the measurement of CO 2 and CH 4 target compounds. In another case, a wavelength band may be included to allow for compensation of an interfering background compound. For example, in combustion gas measurement where moisture is abundant in the sample stream, there may be measurement problems for some target gases including NO and NO 2 , due to spectral interferences. Although moisture is not a target compound, a wavelength band where only moisture is active may be included so it can be measured and used to correct for the errors due to the spectral interferences.
The digitized, wavelength multiplexed spectral information would then be processed to separate the spectrum into the individual compound spectrum, which is then compared against a calibrated spectrum to produce its concentration or density value. This may be accomplished through different types of algorithms including least-squares based chemometrics such as classical least squares (CLS) or principal component analysis (PCA). Following the above example, FIG. 10 is block diagram of a CLS based processing algorithm to speciate and quantify the individual concentrations of the gases. The measured spectrum 1001 is modeled or fitted against the principal calibration matrix 1002 containing calibrated spectra of the individual sample through a least-squares regression algorithm. In the constructive example above, the calibration matrix 1002 would contain a calibrated spectrum of CO 2 and a calibrated spectrum of CH 4 . The outputs of the algorithm, 1003 , would include the quantitative values of the individual samples, such as concentration or density values.
A prototype spectrometer was built and tested to further illustrate the multiplexed spectral measurement. The prototype unit uses a two-band filter, constructed from two separate narrow band-pass filters made by Spectrogon US Inc, Parsippany, N.J. The filter assembly as depicted in FIG. 11A (diagram) and FIG. 11B (photograph) is composed of two D-shaped filters 1101 and 1102 joined together. In this prototype, element 1101 is a narrow band-pass filter with a nominal peak wavelength at 4370 nm (Spectrogon filter part no. NB-4370-020 nm) suitable for CO 2 measurement and element 1102 is a narrow band-pass filter with a nominal peak wavelength at 3520 nm (Spectrogon filter part no. NB-3520-020 nm) suitable for CH 4 measurement. In this prototype, the two filters are joined together using silicon adhesive as shown by the apparent adhesive line 1104 and then ring-mounted on a hard plastic mount 1105 .
FIG. 12 shows an experimentally measured single-beam or transmission spectrum 1203 of the spectrometer when measuring a mixture of CO 2 and CH 4 gases. The absorption peak 1201 corresponds to a CO 2 absorption peak and the absorption peak 1202 corresponds to a CH 4 absorption peak. The transmission spectrum 1204 is a transmission spectrum from a measurement of a background zero gas, which in this case is nitrogen. In this spectrum, no absorption peaks are present since nitrogen is not infrared active and therefore is suitable to use to obtain a zero reference.
FIG. 13 shows the absorption spectrum of the above measurement. The absorption spectrum is obtained by taking a logarithm of the ratio of the zero gas transmission spectrum 1204 and the gas mixture transmission spectrum 1203 . This absorption spectrum more clearly shows the absorption peak due to CO 2 absorption 1301 and the absorption peak due to CH 4 absorption 1302 . In particular, the CO 2 absorption peak 1301 is spectrally located at around 4230 nm and the CH 4 absorption peak 1302 is spectrally located at around 3310 nm (the spectra in wavelength scale are shown in FIG. 8 ). The above experimental measurement demonstrates the capability of the spectrometer in gathering spectra from multiple wavelength bands simultaneously.
EQUIVALENTS
While the invention has been particularly shown and described with reference to specific preferred embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. The relevant teachings of all the references, patents and patent applications cited herein are incorporated herein by reference in their entirety.
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The invention provides spectroscopic systems and spectrometers employing an optical interference filter module having a plurality of bandpass regions. In certain embodiments, the systems include a mechanism for wavelength tuning/scanning and wavelength band decoding based on an angular motion of one or more filters. A spectral processing algorithm separates the multiplexed wavelength-scanned bandpass regions and quantifies the concentrations of the analyzed chemical and/or biological species. The spectroscopic system allows for compact, multi-compound analysis, employing a single-element detector for maximum performance-to-cost ratio. The spectroscopic system also allows for high-sensitivity measurement and robust interference compensation.
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BACKGROUND OF THE INVENTION
[0001] This invention relates to the use of at least one oxygen-fuel burner in the roof of a glass melting furnace to boost production capacity or maintain current production capacity with either reduction of electro-boost or as a result of deterioration of existing heat recovery equipment such as recuperators or regenerators. The process involves the replacement of a portion of existing or previously existing air-fuel or electrical energy capacity with oxy-fuel energy. With the exception of end-fired regenerative furnaces and electric furnaces the process involves the blocking of regenerative ports or isolation of recuperative burners. In particular the design selection, angling and positioning of the burners over the raw batch materials entering the furnace improves the rate of melting, increase product yield, better energy efficiency and improve glass quality. Accurate control of the stoichiometric ratio of combustion in the burner, rich lean interaction of burners and furnace zonal fuel/oxygen staging are used to optimise heat transfer while minimizing oxides of nitrogen and sulfur dioxide emissions.
[0002] Regenerative, recuperative, electric and direct fired furnaces have been commonly involved in the manufacture of glass and related frit products.
[0003] Air-fuel regenerative furnaces fall into two categories: cross-fired and end-fired. Cross-fired regenerative furnaces have multiple ports typically three to eight on each side of the furnace that connect to either a common or compartmentalized regenerator to preheat the combustion air. The regenerators which come in various shapes and sizes reverse every 15-30 minutes dependent on furnace operation. During each reversal cycle combustion air from a fan passing through one passage in the reversal valve enters the base of the regenerator on one side of the furnace and is preheated prior to entering the ports which connect to the furnace. Fuel in the form of oil and/or gas is injected either, under, over, through or side of port to produce a flame which is combusted in the glass melting furnace. The hot products of combustion exit the furnace through the opposing side port, down through the regenerator checker bricks releasing heat and then exiting to the exhaust stack through a second passageway in the reversal valve. As the air-side regenerator cools, the exhaust regenerator heats until the reversal valve reverses and combustion air enters the previously hot exhaust regenerator.
[0004] The glass is melted partly due to the radiation of the air-fuel flame but mainly from re-radiation from the roof and walls which are heated by the products of combustion. To obtain higher furnace glass production capacity, many furnaces use electric boost by means of electrodes immersed in the glass. This is costly and can cause damage to the glass contact tank walls. Through time, regenerators can start to block due to thermal/structural damage and/or carry-over of raw glass forming materials, also known as batch materials or batch, or condensation of volatile species released from the glass batch. As the regenerators start to block or fail, the preheat temperature of the air in the furnace will reduce. Because of the increased pressure drop, the exhaust side will limit the removal of exhaust gases and therefore limit energy input into the furnace thus reducing furnace glass production.
[0005] To recover production capacity lost to preceding regenerator issues or to increase production in a non-encumbered furnace, oxygen has been used by four means: general air enrichment with oxygen, specific oxygen lancing under the port flames, installation of an oxy-fuel burner between first port and charging end wall, and water-cooled oxy-fuel burners installed through the port. The capacity increases from these technologies is limited by access, process requirements or refractory temperature limits.
[0006] The End-Fired Regenerative furnace is similar in operation to a cross-fired furnace, however, has only two ports in the end wall which connect to individual regenerators. Regenerator deterioration is the same mechanism as in cross-fired furnaces and similarly electric and oxygen boost is utilized.
[0007] To recover production capacity lost to the aforementioned regenerator issues or to increase production, oxygen has been used by three means: general air enrichment with oxygen, specific oxygen lancing under the port and installation of oxy-fuel burners through the furnace side walls down tank. These technologies are typically limited on capacity because of location and concerns for overheating of the furnace.
[0008] The recuperative furnace utilizes at least one recuperator type heat exchanger. Unlike the regenerator, the recuperator is continuous with hot concurrent flow heat exchanger where exhaust gases preheat combustion air which is ducted to individual air fuel burners along the sides of the furnace. Recuperative furnaces can also use electric boost. As with regenerative furnaces, recuperators can start to lose their efficiency and ability to preheat the air. They can become blocked or develop holes.
[0009] To recover production capacity lost from the aforementioned recuperator issues or to increase production, oxygen has been used by three means: general air enrichment with oxygen, specific oxygen lancing under the air fuel burners and installation of oxy-fuel burners either through the furnace side or end walls. These technologies are typically limited on capacity because of location restrictions and concerns for overheating of the furnace.
[0010] Direct fired furnaces do not utilize preheated air and are therefore less efficient than the preceding examples of furnace design. To improve thermal efficiency or increase production capacity, side wall oxy-fuel burners have replaced air fuel burners.
[0011] Electric furnaces or furnaces which utilize electricity for majority of melting are typically costly to operate and are subject to a shorter campaign life than the typical fossil fuel furnaces. Once designed it is difficult to increase the production capacity. This invention relates to hot top and warm top electric furnaces and is not applied to cold top furnaces
[0012] U.S. Pat. No. 5,139,558 to Lauwers discloses the use of a high-momentum roof-mounted auxiliary oxygen fired burner in a glass melting furnace which is directed to the interface of the melted and solid glass forming ingredients whereby the solid glass forming ingredients are mechanically prevented from escaping the melting zone.
[0013] U.S. Pat. No. 3,337,324 to Cable discloses a process for melting batch material in a glass furnace using a burner positioned to fire substantially down over the feed end of a water-cooled furnace.
[0014] Co-pending U.S. patent application Ser. No. 08/992,136 discloses the use of roof-mounted burners as the primary source of heat in a glass melting furnace having no regenerators or recuperators.
SUMMARY OF THE INVENTION
[0015] Briefly, according to this present invention, glass melting furnaces of all designs can be boosted using at least one roof-mounted oxygen fuel burners positioned over the raw batch materials as the materials enter the furnace to improve the rate of melting and improve glass quality and/or glass product yield. Because of the increased rate and yield of the glass melting generated by the design and positioning of these burners, depending on furnace condition and type, at least one or more of the following can be achieved: increased glass production, improved glass quality, reduction in electric boost, recovery of production lost due to inefficient heat recovery (i.e., blocked regenerators), reduction of oxygen use by replacing oxygen enrichment of the furnace atmosphere, reduction of oxygen use by replacing oxygen lancing, reduction of oxygen use by replacing conventional oxy-fuel burners positioned through the walls of a glass furnace, increased furnace campaign life, improved energy efficiency, reduction in emissions of oxides of nitrogen and oxides of sulfur, reduction in fossil fuel usage, reduction in cullet and increased product glass yield.
[0016] This invention may be applied to the following types of furnaces. In hot top electric furnace applications of this invention, at least one oxygen-fuel burner will be mounted in the roof of the furnace. In cross-fired regenerative furnace applications of this invention may necessitate at least one pair of the opposing ports to be fully or partially blocked or isolated. In end-fired regenerative furnace applications of this invention, at least one oxygen-fuel burner will be mounted in the roof of the furnace and the combustion air flow reduced by a portion of the original design maximum flow. In all recuperative furnace applications of this invention, at least one oxygen-fuel burner will be mounted in the roof of the furnace. In multi-burner furnaces, burners adjacent to the roof mounted burners should be removed and the air supply isolated. In single burner or single port applications the combustion air flow will be reduced by a portion of the original design maximum flow.
[0017] In all direct fired furnace applications of this invention, at least one oxygen-fuel burner will be mounted in the roof of the furnace. In multi-burner furnaces, burners adjacent to the roof mounted burners should be removed and the air supply discontinued. In single burner or single port applications, the combustion air flow will be reduced by a portion of the original design maximum flow.
[0018] In all the above cases the scope of the invention is effectively the same: glass melting which was previously performed by air-fuel or oxy-fuel including but not exclusive of furnaces that utilize electric boost or conventional oxygen boosting methods, is replaced by roof-mounted oxy-fuel burners positioned over the raw batch materials entering the furnace to improve the rate of melting and/or improve glass quality and/or glass product yield. Because of the ability to position these burners at specific locations, increased heat transfer to the unmelted raw batch materials is achieved.
[0019] In all cases at least one roof-mounted oxy-fuel burner is positioned over the raw batch materials entering the furnace to improve the rate of melting and improvement in quality is utilized and in all multi-port and multi-burner air fuel applications at least one pair of ports or pair of burners are isolated. In all single port and single burner applications the air and fuel are reduced to a portion below the maximum design. The more efficient roof mounted burners provide energy to replace the conventional energy removed from the process and the additional energy to achieve the desired process requirements. The positioning of the burners over the raw batch entering the furnace improves the rate of melting. The stoichiometric ratios and control of the roof-mounted burners and remaining air-fuel burners is critical to minimizing the emission of nitrous oxide and sulfur dioxide.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Further features and other objects and advantages of this invention will become clear from the following detailed description made with reference to the drawings in which:
[0021] [0021]FIG. 1 is a cross sectional longitudinal view of a glass meting furnace in accordance with the present invention.
[0022] [0022]FIG. 2A is a cross-sectional plan view of a cross-fired regenerative embodiment of the glass melting furnace of FIG. 1 along line 2 - 2 .
[0023] [0023]FIG. 2B is a cross-sectional plan view of an end-fired regenerative embodiment of the glass melting furnace of FIG. 1 along line 2 - 2 .
[0024] [0024]FIG. 2C is a cross-sectional plan view of a cross-fired recuperative embodiment of the glass melting furnace of FIG. 1 along line 2 - 2 .
[0025] [0025]FIG. 2D is a cross-sectional plan view of an end-fired recuperative embodiment of the glass melting furnace of FIG. 1 along lines 2 - 2 .
[0026] [0026]FIG. 2E is a cross-sectional plan view of a unit melter embodiment of the glass melting furnace of FIG. 1 along lines 2 - 2 .
[0027] [0027]FIG. 3 is a cross sectional view of the glass melting furnace of FIG. 1 along line 3 - 3 illustrating two oxygen-fuel burners adjacent the upstream end wall of the furnace.
[0028] [0028]FIG. 4 is an alternate cross sectional view of the glass melting furnace of FIG. 1 along line 3 - 3 illustrating one oxygen-fuel burner adjacent the upstream end wall of the furnace.
[0029] [0029]FIG. 5 is a cross sectional view of an oxygen fuel burner and a schematic representation of a burner flame from the oxygen burner.
DETAILED DESCRIPTION OF THE INVENTION
[0030] Referring to the figures, there is shown a glass melting furnace 10 for providing molten glass to a glass forehearth or refiner 12 wherein the molten glass is further refined and subsequently fed to one or more glass-forming machines such as containers, fiberizers, float baths and the like (not shown). In considering the figures, it will be appreciated that for purposes of clarity certain details of construction are not provided in view of such details being conventional and well known by someone skilled in the art once the invention is disclosed and explained. Specific items excluded are the regenerator ports, air-fuel burners and exhausts since these are different for each type of furnace.
[0031] The glass melting furnace 10 typically includes an elongated channel having an upstream end wall 14 and a downstream end wall 16 , side walls 18 a floor 20 and a roof 22 all made from appropriate refractory materials such as alumina, silica, alumina-silica, zircon, zirconia-alumina-silica chromeoxide and the like. The roof 22 is shown generally as having an arcuate shape transverse to the longitudinal axis of the channel, however, the roof may be of most any suitable design. The roof 22 of the typical glass melting furnace 10 is positioned between about 3-15 feet above the surface of the raw glass-forming material. As well known in the art, the glass melting furnace 10 may optionally include one or more bubblers 24 and/or electrical boost electrodes (not shown). The bubblers and/or electrical boost electrodes increase the temperature of the bulk glass and increase the molten glass circulation under the batch cover.
[0032] The glass melting furnace 10 includes two successive zones, a melting zone 27 and a downstream fining zone 28 . The melting zone 27 is considered the upstream zone of the glass melting furnace 10 wherein raw glass-forming material is charged into the furnace using a charging device 32 of a type well known in the art. The raw glass-forming material 30 may be a mixture of raw materials typically used in the manufacture of glass. It will be appreciated that the composition of the raw glass-forming material (or batch) 30 is dependent on the type of glass being produced. Normally, the material comprises, inter alia, silica containing materials including scrap glass commonly referred to as cullet. Other glass-forming materials including feldspar, limestone, dolomite, soda ash, potash, borax and alumina may also be used. To alter the properties of the glass, a minor amount of arsenic, antimony, sulfates, carbon and/or fluorides may also be added. Moreover, color forming metal oxides may be added to obtain the desired color.
[0033] The raw glass-forming material 30 forms a batch layer of solid particles on the surface of the molten glass in the melting zone 27 of the glass melting furnace 10 . The floating solid batch particles of raw glass-forming material 30 are melted principally by at least one oxygen-fuel burner 34 having a controlled impinging flame shape and length mounted within the roof 22 of the glass melting furnace 10 . It will be appreciated that it has been found that the installation and proper control of at least one oxygen-fuel burner 34 in the roof 22 of the glass melting furnace 10 over the raw glass-forming material 30 in accordance with the present invention increases the melting rate of the solid raw glass-forming material and, at the same time, maintains the operating temperature of the surrounding refractory material within acceptable operating limits.
[0034] As used herein, the phrase “at least one oxygen-fuel burner” means one or more oxygen fuel burners. Furthermore, as used herein the phrase “principally by at least one oxygen-fuel burner” refers to the condition wherein the additional or recovered glass production capacity and replaced air fuel and or electric/oxygen boost energy for melting of the raw glass-forming material is from at least one oxygen-fuel burner. In one particular embodiment, as shown in FIGS. 1 and 2A the glass melting furnace 10 includes three oxygen-fuel burners 34 . A single oxygen-fuel burner 34 is positioned upstream of two adjacently positioned downstream oxygen fuel burners. However, it will be appreciated that any number of oxygen-fuel burners 34 may be positioned at almost any suitable location in the roof 22 of the furnace 10 over the batch to melt the raw glass-forming material 30 . For example, two oxygen-fuel burners 34 may be positioned in a side-by-side relation as depicted in FIG. 3 or a single oxygen-fuel burner may be used as depicted in FIG. 4. Nonetheless, in accordance with the present invention, the angular orientation of each oxygen-fuel burner 34 in the roof 22 of the glass melting furnace must be such that the flame 36 produced is directed substantially perpendicular to the glass batch surface to produce a flame which impinges on the glass surface to form an impingement area 26 . In a preferred embodiment, the oxygen-fuel burners 34 are positioned substantially perpendicular to the batch material at an angle of about 90 degrees relative to the raw glass-forming material 30 . The angle may deviate from the perpendicular in the direction of the downstream end-wall by as much as 30 degrees, but preferably less than 10 degrees. It has been found that the glass production rate and the quality of glass produced may be improved by melting the raw glass-forming material 30 with at least one downwardly firing oxygen-fuel burner 34 having a controlled impinging flame shape and length in accordance with the present invention.
[0035] The at least one oxygen-fuel burner requires fuel and an oxidant. The fuel can be either gaseous or liquid or combinations of both. Gaseous fuels include natural gas (methane), towns gas, producer gas, LPG, propane, butane and blends of the aforementioned gases. Liquid fuels include heavy, medium and light fuel oils, kerosene and diesel. Liquid fuels require to be atomized and/or vaporized. The atomization can be either by mechanical means or a secondary atomizing mediums which include air, steam, oxygen, any of the aforementioned gaseous fuels and in some cases an inert gas. Vaporization relies on the heat of the surrounding products of combustion gases to evaporate the oil. The oxidant can be either 100% pure oxygen or a blend of oxygen and inert gas with an oxygen concentration 40-100%.
[0036] Referring to FIG. 5, the at least one oxygen-fuel burner 34 within the roof 22 of the glass melting furnace 10 has at least one fuel conduit 40 for providing fuel and at least one oxygen conduit 42 for providing oxygen flow. The oxygen-fuel burner 34 may have a capacity ranging from about 1-15 MM Btu/hr depending upon the glass melting furnace 10 size and desired pull rate. The oxygen-fuel burner 34 is designed to use a higher percentage of oxygen than is present in air and thus the temperature above the area of impingement of the flame 36 from the oxygen-fuel burner 34 is substantially higher than in a conventional glass melting furnace utilizing air-fuel burners. Notwithstanding, as well known to one skilled in the art the temperature of the flame 36 imparted by an oxygen-fuel burner 34 is dependent on the quality of the fuel and the oxygen/fuel ratio. In a preferred embodiment, the oxygen concentration of the oxygen-fuel burner 34 is typically at a level of about 95-125 percent of the stoichiometric amount of oxygen required to combust the fuel. The fuel to oxygen ratio can be varied, however, to produce a range of operating conditions in the glass melting furnace 10 to effect one or more desired properties, including, for example, redox level, glass color, the level of gaseous bubbles known as seeds in the trade and other glass properties.
[0037] The oxygen-fuel burner 34 extends downwardly from a burner block 38 located in the roof 22 of the glass melting furnace 10 . Each primary burner block 38 includes an opening having an inside diameter (id) which is at least as great as the external diameter of the largest conduit 42 or 40 dependent on configuration. The inside diameter (id) of the opening of the burner block 38 may range between about 2-8 inches. The end of the oxygen-fuel burner 34 primary combustion zone is located from the end of the burner block 38 a distance (LBb) between about 0-18 inches. The secondary and in some cases tertiary combustion zone is external to the burner block 38 . It will be appreciated that the opening of the burner block 38 between the end of the oxygen-fuel burner 34 and the end of the burner block in some instances acts to focus the burner flame and prevent the burner flame from spreading outwardly but moreover protects the conduits of the burner. The burner block 38 is made of a refractory material as well known in the art and may be of most any suitable outside shape such as rectangular and the like.
[0038] The bottom surface of the burner block 38 may be flush with the inside surface of the roof 22 or the bottom surface may project below the inside surface of the roof to a maximum distance of 2 inches to protect the burner block 38 from wear. Furthermore, as shown in FIG. 5, the fuel conduits 40 and oxygen conduits 42 of the oxygen-fuel burner 34 extend downwards within the burner block 38 and terminate at either substantially the same vertical height or totally different vertical heights from the exit of burner block 38 .
[0039] Dependent on height of burner block 38 from raw batch and desired operating conditions of the burner, the greater the fraction of fuel staging and oxygen staging internal and external to the burner block 38 will vary. Additional oxygen injectors 60 are positioned to delay complete combustion until after the flame has impinged on the raw batch. The location of these additional injectors 60 is dependent on number and position of roof mounted burners however can be located in any point of the roof and walls.
[0040] In accordance with the present invention, the downwardly directed impinging flame 36 produced by the at least one oxygen-fuel burner 34 is precisely controlled to give a flame length greater than or equal to the distance from the exit of burner block 38 to the surface of the raw glass-forming ingredients 30 and the surface of the molten glass and away from the surrounding refractory thereby reducing the risk of overheating the roof 22 and side walls 18 of the glass melting furnace 10 . The impinging flame 36 may be controlled by such control devices as are conventional and standard in chemical processing. For example, valves, thermocouples, thermistors coupled with suitable servo circuits, heater controllers and the like are readily available and conventionally used for controlling the quantity and velocity of the fuel and oxygen from the oxygen-fuel burner 34 .
[0041] The impinging flame 36 is precisely controlled by controlling both the relative velocity and the maximum and minimum velocities of the fuel and of the oxygen streams and the internal and external staging from the at least one oxygen-fuel burner 34 .
[0042] The maximum and minimum velocity of the fuel and oxygen flow impinging on the surface of the raw glass-forming material 30 must be controlled to prevent the disturbance of the batch material and entrainment of or the displacement of glass batch material against the side walls 18 and roof 22 while maintaining optimum convective heat transfer to the surface of the raw glass-forming material. It will be appreciated that the displacement of glass batch material against the side walls 18 and roof 22 will adversely effect the refractory material and possibly shorten the operating life of the glass melting furnace 10 .
[0043] In order to determine the proper maximum velocity for the fuel and oxygen flow a burner was vertically mounted and fired downwards into a bed of glass sand across which grooves had been made. While the burner was adjusted to different heights from the sand and burner retractions into the block (LBb) the firing rates at which sand movement was discerned was noted. The data from these experiments was compared against simulations run on a commercially available computational fluid dynamics code thus yielding a maximum velocity across the surface above which sand would be disturbed in the aforementioned experiments.
TABLE 1 Maximum. Burner Firing Rates (MMBtu/Hour) Height (feet) L(Bb) 5 ft 6 ft 7 ft 8 ft 13 3.9 4.4 5.4 6.2 11.5 4.9 5.0 6.2 6.8 9 5.5 6.1 6.4 7.1 6.5 6.4 7.2 7.4 8.1 4 6.9 8.8 8.3 9.1
[0044] From these experiments the maximum surface velocity was ascertained by comparison with the CFD models to be approximately 21 m/s. Due to variations in batch material, batch glazing and batch particle cohesion the exact maximum may differ from the above calculated maximum, therefore, it should be possible for one skilled in the art to vary the maximum velocity up to approximately 25 m/sec. To minimize disturbance and entrainment of the batch material, however, the maximum velocity should be kept below 30 m/sec.
[0045] The maximum and minimum velocity of the fuel and of the oxygen of the oxygen-fuel burner 34 are also controlled to harness the maximum energy from the impinging flame 36 without damaging the surrounding refractory material. The maximum energy from the impinging flame 36 is achieved by minimizing the amount of heat released to the glass melting furnace 10 combustion space and maximizing the heat transfer to the raw-glass forming material 30 . The operational maximum and minimum velocity range for the oxygen-fuel burner 34 to generate an acceptable heat transfer rate to the raw glass-forming material 30 without damaging the refractory material furnace walls and superstructure is a function of the design and location of the oxygen-fuel burner, burner block opening geometry, the velocities of the fuel and oxygen from the oxygen-fuel burner 34 , burner staging, interaction of adjacent oxygen-fuel burners, fuel burners and furnace exhaust.
[0046] The second region, the stagnation region 56 , is the region where the flame 36 penetrates the thermal boundary layer and impinges upon the surface of the raw glass-forming material 30 . Within this region 56 , the flame 36 penetrates the thermal boundary layer and impinges on the surface of the raw glass-forming material building a sharp pressure gradient at the surface that accelerates the horizontal flow of the deflected flame causing the flame to spread outwardly radially along the impinged surface. The end of the stagnation region 56 is defined as the location on the surface of the raw glass-forming material where the pressure gradient generated by the impinging flame 36 drops to zero. Within the stagnation region 56 , by carefully controlling the momentum of flame 36 , the thermal boundary layer that naturally exists at the surface of the raw glass-forming material 30 is penetrated and eliminated and thus its strong heat resistive features are attenuated. Accordingly, the heat generated by the impinging flame 36 penetrates more easily into the partially melted raw glass-forming material 30 . Furthermore, within the stagnation region 56 the flame 36 luminosity significantly increases which enhances the radiation heat transfer into the relatively colder raw glass-forming material 30 .
[0047] At the radial limits of the stagnation region 56 the wall jet region 58 begins. In this region, the flame 36 flows essentially parallel to the impinged surface and the thermal boundary layer grows along the impingement surface and outward from the stagnation region 56 , thus the thermal boundary layer starts to build up restoring the surface resistance to the heat flow into the raw glass-forming material surface.
[0048] The controlled flame heat generation in the free-jet region 54 is the result of the design of the oxygen-fuel burner 34 , inside diameter of the opening (id) of the burner block 38 and both the relative velocities and maximum and minimum velocities of the oxygen and fuel streams. By selectively controlling the design of the oxygen-fuel burner 34 , the burner block 38 geometrical design and the velocities of the oxygen and fuel streams a reduced shear stress between the oxygen and gas streams is produced providing controlled partial combustion and reduced thermal radiation emissions. It will be appreciated that by optimizing burner design and operation of the oxygen-fuel burner 34 , the flame heat generated in the free jet region 54 and the heat transfer resistance at the raw glass surface in the stagnation region 56 are minimized thereby maximizing the heat generated in the stagnation region.
[0049] The heat generated in the free-jet region 54 is the result of the following processes. First, the controlled partial combustion in the free-jet region 54 permits controlled combustion at the surface of the raw glass-forming material 30 thereby bringing the combustion process proximate to the surface of the raw glass-forming material. Bringing the combustion process proximate the surface of the raw glass-forming material 30 generates an elevated temperature gradient at the surface of the raw glass-forming material thereby improving the convection heat transfer. Second, the controlled partial combustion in the free-jet region 54 generates an acceptable temperature for the chemical dissociation of the combustion gases and the products of combustion. These dissociated species, once impinged on the relatively colder surface of the raw glass-forming material 30 , partially recombine, exothermically, generating significant heat at the surface of the raw glass-forming material. The heat from the exothermic reactions further augments the convective heat transfer process. The minimization of the heat resistance at the stagnation region 56 of the surface of the raw glass-forming material 30 is the result of the following factors.
[0050] First, the thermal boundary layer is eliminated through the controlled flame 36 momentum and the turbulence generated by the carefully controlled combustion characteristics at the surface of the raw glass-forming material 30 . Second, the localized surface heat generation allows for the conversion of the low thermal conductive raw glass-forming material 30 into a significantly better conductive molten glass material. This conversion allows for the heat generated at the surface to penetrate more efficiently into the raw glass-forming material depth.
[0051] In the cross-fired regenerative furnace FIG. 2A with regenerators 81 the preferred embodiment of the present invention utilizes at least one crown mounted burner 34 positioned over the raw batch materials entering the furnace to improve the rate of melting and improvement in quality to recover or boost production capacity or reduce electric boost capacity. Crown-mounted burner 34 impinges the surface of the batch material 30 in impingement area 26 . In all cross-fired regenerative furnace applications of this invention at least one pair of the opposing ports 71 will be fully or partially blocked or isolated. This will typically be the first port and perhaps the second port dependent on the amount of boost required. Additional roof-mounted burners can be located down the glass tank provided the crown mounted burners are positioned over the unmelted batch materials. The energy deliberated from the crown mounted burners replaces energy removed from the previously firing ports, the removed conventional electric or oxy-boost.
[0052] In the end-fired regenerative furnace of FIG. 2B with regenerators 81 the preferred embodiment of the present invention utilizes at least one crown mounted burners 34 positioned over the raw batch materials entering the furnace to improve the rate of melting and improvement in quality to recover or boost production capacity or reduce electric boost capacity. In all end-fired regenerative furnace applications of this invention the combustion air and conventional fuel requirements will be reduced from the previous design and replaced with energy from the at least one crown mounted burners 34 positioned over the raw batch materials and impinging the batch materials in impingement area 26 . Additional roof-mounted burners can be located down the glass tank provided the crown mounted burners are positioned over the unmelted batch materials. The energy deliberated from the crown mounted burners replaces energy reduced from the firing port, the removed conventional electric or oxy-boost.
[0053] In the cross-fired recuperative furnace of FIG. 2C with recuperator 82 the preferred embodiment of the present invention utilizes at least one roof mounted burner 34 positioned over the raw batch materials entering the furnace to improve the rate of melting and improvement in quality to recover or boost production capacity or reduce electric boost capacity. In all cross-fired recuperative furnace applications of this invention at least one pair of the opposing burners 73 will be fully or partially blocked or isolated using a block 74 . This will typically be the first zone of burners and perhaps the second zone dependent on the amount of boost required. Additional roof-mounted burners can be located down the glass tank provided the crown mounted burners are positioned over the unmelted batch materials. The energy deliberated from the crown mounted burners replaces energy removed from the previously firing ports, the removed conventional electric or oxy-boost.
[0054] In the end-fired recuperative furnace of FIG. 2D with recuperator 82 the preferred embodiment of the present invention utilizes at least one crown mounted burner 34 positioned over the raw batch materials entering the furnace to improve the rate of melting and improvement in quality to recover or boost production capacity or reduce electric boost capacity. In all end-fired recuperative furnace applications of this invention the combustion air and conventional fuel requirements will be reduced from the previous design and replaced with energy from the at least one crown mounted burner 34 positioned over the raw batch materials. Additional roof-mounted burners can be located down the glass tank provided the crown mounted burners are positioned over the unmelted batch materials. The energy deliberated from the crown mounted burners replaces energy reduced from the firing port, the removed conventional electric or oxy-boost.
[0055] In the direct-fired furnace of FIG. 2E The preferred embodiment of the present invention utilizes at least one crown mounted burners positioned over the raw batch materials entering the furnace to improve the rate of melting and improvement in quality to recover or boost production capacity or reduce electric boost capacity. In all direct fired furnace applications of this invention the combustion air and conventional fuel requirements will be reduced from the previous design and replaced with energy from the at least one crown mounted burners positioned over the raw batch materials. In multi-air-fuel-burner 73 applications at least one burner 74 will be isolated. Additional roof-mounted burners can be located down the glass tank provided the crown mounted burners are positioned over the unmelted batch materials. The energy deliberated from the crown mounted burners replaces energy reduced from the firing port, the removed conventional electric or oxy-boost.
[0056] In an electric hot top furnace the preferred embodiment of the present invention utilizes at least one crown mounted burners positioned over the raw batch materials entering the furnace to improve the rate of melting and improvement in quality to recover or boost production capacity or reduce electric boost capacity. Additional roof-mounted burners can be located down the glass tank provided the crown mounted burners are positioned over the unmelted batch materials. The energy deliberated from the crown mounted burners replaces energy reduced from the firing port, the removed conventional electric or oxy-boost.
[0057] In all cases nitrogen oxides and sulfur dioxide can be reduced by the careful selection of stoichiometric ratio of the different roof-mounted burners and remaining air fuel burners. Referring to FIG. 2A as an example in the cross-fired furnace application., the burners 34 mounted in the AL or AR positions are operated with excess stoichiometric oxygen to create a fuel lean (oxidizing) zone in the furnace. By operating either burner 34 at position BC and or burners at the second port 71 with less than stoichiometric oxygen or air creates a fuel rich (reducing) zone in the furnace. The remaining ports are operated with excess stoichiometric oxygen to create a fuel lean (oxidizing) zone in the furnace. This rich-lean-rich configuration effectively stages the combustion zones of the furnace to optimize heat transfer and minimize nitrogen oxide formation by creating a carbon monoxide screen.
[0058] The at least one roof mounted oxygen-fuel burner 34 may be either placed in a new air-fuel glass melter furnace 10 or retrofitted into an existing air-fuel glass melter furnace to increase the glass quality relative to an air-fuel only fired furnace. It will be appreciated that the present invention facilitates a substantial pull rate increase, reduction in glass melting furnace 10 wall temperature and improved glass quality as compared to the same air-fuel furnace that is not retrofitted with at least one roof mounted oxygen-fuel burner as described herein. Furthermore, as will be readily appreciated by one skilled in the art, the use of at least one oxygen-fuel burner as opposed to an all air-fuel system appreciably reduces NO x emissions.
[0059] One demonstration of this invention was the oxygen boosting, 100% oxygen conversion, re-conversion to oxygen boost and finally conventional air fuel firing of an existing hot 3-port cross-fired regenerative furnace. The furnace was initially firing all air fuel. Port#1 firing was replaced with at least one roof mounted oxygen fuel burner. The furnace fired conventionally air fuel regenerative on remaining two ports. Port#2 firing was replaced with at least one roof mounted air fuel burner and the furnace fired conventionally air fuel regenerative on the third port. Port#3 firing was replaced with energy in the already installed roof-mounted oxy-fuel burners. The furnace capacity was increased from 55 to 85 tons per day with reduced energy input from 23.5 mmBTU/hr to 18 mmBTU/hr. The furnace was re-converted to air fuel firing in incremental stages. This example demonstrates the ability to selectively boost an existing air fuel furnace. The process does not require water-cooled burners.
[0060] The patents and documents described herein are hereby incorporated by reference.
[0061] Although the invention has been described in detail with reference to certain specific embodiments, those skilled in the art will recognize that there are other embodiments within the spirit and scope of the claims.
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In an industrial glass furnace which contains recuperators, regenerators, electric boost or other devices for providing heat to glass batch material an oxy-fuel burner mounted in the roof of the furnace provides additional heat to melt the batch material. A method of mounting and using such a roof-mounted oxy-fuel burner including the operating parameters to maximize heat transfer while minimizing the disturbance of the batch material is disclosed.
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[0001] This application is a continuation of U.S. patent application Ser. No. 11/860,590 filed on Sep. 25, 2007 which is a division of U.S. patent application Ser. No. 11/107,074 filed on Apr. 15, 2005.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of integrated circuit manufacture; more specifically, it relates to an interconnect structure and method of fabricating the interconnect structure for wiring levels of an integrated circuit.
BACKGROUND OF THE INVENTION
[0003] Advanced integrated circuits utilize copper and other metallurgy in the interconnect or wiring levels in order to increase performance of the integrated circuit. Because of the possibility of copper and other metal diffusion through interlevel dielectric layers, copper and other metal interconnects are fabricated with conductive diffusion barrier liners on the sides and bottoms of the wires and dielectric copper and other metal diffusion barrier caps on the top surface of the wires. However, it has been found that wires using dielectric diffusion barrier caps are susceptible to reliability failures.
[0004] Therefore, there is a need for improved diffusion barrier capped interconnect structures.
SUMMARY OF THE INVENTION
[0005] The present invention utilizes electrically conductive diffusion barrier caps to seal surfaces of damascene and dual damascene interconnect structures not covered by electrically conductive liners or dielectric layers that may also act as diffusion barriers. The caps (and electrically conductive liners and dielectric layers, when acting as diffusion barrier) are diffusion barriers to a material contained in the core electrical conductor of a damascene or dual damascene line.
[0006] A first aspect of the present invention is a method, comprising: providing a substrate having a dielectric layer; forming a hard mask layer on a top surface of the dielectric layer; forming an opening in the hard mask layer; forming a trench in the dielectric layer where the dielectric layer is not protected by the hard mask layer, the trench having sidewalls and a bottom; recessing the sidewalls of the trench under the hard mask layer; forming a conformal electrically conductive liner on all exposed surfaces of the trench and the hard mask layer; filling the trench with a core electrical conductor; removing portions of the electrically conductive liner extending above the top surface of the dielectric layer and removing the mask layer; and forming an electrically conductive cap on a top surface of the core electrical conductor.
[0007] A second aspect of the present invention is a method comprising: providing a substrate having a dielectric layer; forming a hard mask layer on a top surface of the dielectric layer; forming an opening in the hard mask layer; forming a trench in the dielectric layer where the dielectric layer is not protected by the hard mask layer, the trench having sidewalls and a bottom, the sidewalls of the trench aligned with the opening in the hard mask; performing an isotropic etch of the sidewalls and bottom of the trench, the isotropic etch undercutting the hard mask layer and forming a hard mask overhang projecting over the trench; forming a conformal electrically conductive liner on all exposed surfaces of the trench and on all exposed surfaces of the hard mask layer, an upper portion of the electrically conductive liner in physical contact with the hard mask overhang and forming an electrically conductive overhang projecting over the trench; forming a core electrical conductor over the electrically conductive liner, the core electrical conductor filling the trench; performing a chemical-mechanical polish to remove the hard mask layer and all core electrical conductor extending above the top surface of the dielectric layer, the chemical-mechanical-polishing making coplanar a top surface of the dielectric layer, a top surface of the electrically conductive liner and a top surface of the core electrical conductor in the trench, the electrically conductive layer extending over and in direct physical contact with the core electrical conductor; and forming an electrically conductive cap on the top surface of the core electrical conductor.
[0008] A third aspect of the present invention is a structure, comprising: a core electrical conductor having a top surface, an opposite bottom surface and sides between the top and bottom surfaces; an electrically conductive liner in direct physical contact with and covering the bottom surface and the sides of the core electrical conductor, embedded portions of the electrically conductive liner in direct physical contact with and extending over the core electrical conductor in regions of the core electrical conductor adjacent to both the top surface and the sides of the core electrical conductor; and an electrically conductive cap in direct physical contact with the top surface of the core electrical conductor that is exposed between the embedded portions of the electrically conductive liner.
[0009] A fourth aspect of the present invention is a structure, comprising: a core electrical conductor having a top surface, an opposite bottom surface and sides between the top and bottom surfaces; a dielectric liner formed on the sides of the core electrical conductor; an electrically conductive liner in direct physical contact with and covering the bottom surface of the core electrical conductor and the dielectric liner, embedded portions of the electrically conductive liner extending over the dielectric liner and the core electrical conductor in regions of the core electrical conductor adjacent to both the top surface and the sides of the core electrical conductor; and an electrically conductive cap in direct physical contact with the top surface of the core electrical conductor that is exposed between the embedded portions of the electrically conductive liner.
BRIEF DESCRIPTION OF DRAWINGS
[0010] The features of the invention are set forth in the appended claims. The invention itself, however, will be best understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
[0011] FIGS. 1A through 1H are cross-sectional views illustrating common process steps for fabricating an interconnect structure according to both first and second embodiments of the present invention;
[0012] FIGS. 2A through 2C are cross-sectional views illustrating process steps for fabricating an interconnect structure according to the first embodiment of the present invention;
[0013] FIGS. 3A through 3E are cross-sectional views illustrating process steps for fabricating an interconnect structure according to the r second embodiment of the present invention;
[0014] FIG. 4 is a cross-sectional view illustrating multiple wiring levels fabricated according to the first embodiment of the present invention; and
[0015] FIG. 5 is a cross-sectional view illustrating multiple wiring levels fabricated with additional diffusion barriers applicable to the first and the second embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] For the purposes of describing the present invention, the terms conductor and conductive should be reads as electrical conductor and electrically conductive.
[0017] A (single) damascene process is one in which wire trench or via openings are formed in a dielectric layer, an electrical conductor deposited on a top surface of the dielectric of sufficient thickness to fill the trenches and a chemical-mechanical-polish (CMP) process performed to remove excess conductor and make the surface of the conductor co-planer with the surface of the dielectric layer to form damascene wires (or damascene vias).
[0018] A dual damascene process is one in which via openings are formed through the entire thickness of a dielectric layer followed by formation of trenches part of the way through the dielectric layer in any given cross-sectional view. All via openings are intersected by integral wire trenches above and by a wire trench below, but not all trenches need intersect a via opening. An electrical conductor is deposited on a top surface of the dielectric of sufficient thickness to fill the trenches and via opening and a CMP process performed to make the surface of the conductor in the trench co-planer with the surface the dielectric layer to form dual damascene wire and dual damascene wires having integral dual damascene vias.
[0019] The structure of present invention will be described as being fabricated to connect to a contact level of an integrated circuit chip using a dual damascene process copper metallurgy process, though the present invention is applicable to metallurgies other than copper. A contact level is a transitional level, connecting devices such as metal-oxide-silicon field effect transistors (MOSFETs) to the first of wiring level of an integrated circuit, where the individual devices are “wired” into circuits. It should be understood that the structure of the present invention may be formed in any or all of these wiring levels as illustrated in FIGS. 4 and 5 and as well as using a single damascene process.
[0020] FIGS. 1A through 1H are cross-sectional views illustrating common process steps for fabricating an interconnect structure according to both first and second embodiments of the present invention. In FIG. 1A , formed on a substrate 100 is a dielectric layer 105 . A dielectric diffusion barrier 110 is formed on a top surface 115 of dielectric layer 105 . Formed through diffusion barrier 110 and dielectric layer 105 is a stud contact 120 . A top surface 125 of stud contact 120 is coplanar with a top surface 130 of barrier layer 110 . In one example, barrier 110 is a diffusion barrier to materials contained in subsequently formed wires. In one example, barrier 110 is a diffusion barrier to copper.
[0021] In FIG. 1B , a dielectric layer 135 is formed on top surface 130 of barrier layer 110 and a hard mask layer 140 is formed on a top surface 145 of dielectric layer 135 .
[0022] In one example, dielectric layer 135 is a low K (dielectric constant) material, examples of which include but are not limited to hydrogen silsesquioxane polymer (HSQ), methyl silsesquioxane polymer (MSQ) and polyphenylene oligomer (SiO x (CH 3 ) y ). A low K dielectric material has a relative permittivity of about 4 or less.
[0023] In a second example, dielectric layer 135 comprises SiO 2 . Dielectric layer 135 may be, for example, between about 50 nm and about 1,000 nm thick. In one example, hard mask layer 140 may comprise, for example, silicon dioxide (SiO 2 ), silicon nitride (Si 3 N 4 ), silicon carbide (SiC), silicon oxy nitride (SiON), silicon oxy carbide (SiOC), hydrogen doped silica glass (SiCOH), plasma-enhanced silicon nitride (PSiN x ) or NBLoK (SiC(N,H)). Hard mask layer 140 may be, for example, between about 5 nm and about 100 nm thick. It is possible for hard mask layer 140 to comprise a metal.
[0024] In FIG. 1C , a patterned photoresist layer 150 is formed on a top surface 155 of hard mask layer 140 , the photoresist is layer patterned by any number of well known lithographic processes and a trench 155 etched through hard mask layer 140 , exposing top surface 145 of dielectric layer 140 .
[0025] In FIG. 1D , patterned photoresist layer 150 (see FIG. 1C ) is removed and a trench 160 is formed, for example using a reactive ion etch (RIE) process, into dielectric layer 135 to expose top surface 125 of stud contact 120 using patterned hard mask layer 140 as an etch mask.
[0026] In FIG. 1E , another patterned photoresist layer 165 is formed on a top surface 155 of hard mask layer 140 , the photoresist is layer patterned by any number of well known lithographic processes and trenches 155 A (trench 155 of FIG. 1C widened) and 170 are etched through hard mask layer 140 , exposing top surface 145 of dielectric layer 140 .
[0027] In FIG. 1F , patterned photoresist layer 165 (see FIG. 1E ) is removed and a trenches 175 and 180 are etched, for example using an RIE process, part way into dielectric layer 135 . Trench 180 intersects trench 160 .
[0028] In FIG. 1G , overhangs 185 of hard mask layer 140 are created by isotropic removal of a layer of dielectric layer 135 exposed in trenches 160 , 175 and 180 . In a first example, the isotropic removal of a layer of dielectric layer 135 may be accomplished by wet etching in solution comprising HNO 3 , HCl, H 2 SO 4 , HF, NH 4 OH, NH 4 F or combinations thereof. In a second example, the isotropic removal of a layer of dielectric layer 135 may be accomplished by a high-pressure plasma etch having low directionality.
[0029] Using trench 175 as an example, if the widest portion of the opening in hard mask layer 140 is W 1 , and the overhang has a width W 2 , then the ratio W 2 /W 1 may be between about 0.03 and about 0.48
[0030] In FIG. 1H , a conformal conductive liner 190 is formed over top surface 155 of hard mask layer 140 , all exposed surfaces of overhangs 185 , including bottom surfaces 195 of the overhangs, exposed surfaces 200 of trenches 160 , 175 and 180 , and a top surface 125 A of stud contact 120 . In one example, liner 190 is a diffusion barrier to the material(s) of a core conductor 210 (see FIG. 2A or 3 C) that will be later formed over the liner. In one example, liner 190 is a diffusion barrier to copper. In one example liner 190 comprises Ta, TaN, Ti, TiN, TiSiN, W, Ru or combinations thereof. In one example, liner 190 is between about 2 nm and about 100 nm thick. Liner 190 may be formed, for example by chemical vapor deposition (CVD) or atomic layer deposition (ALD).
[0031] Alternatively, liner 190 may be formed in a process of conformal deposition of liner material followed by a simultaneous sputter etch (using a charged sputtering species) and liner deposition as metal neutrals process as taught in U.S. Pat. No. 6,784,105 to Yang et al., issued on Aug. 31, 2004 which is hereby incorporated by reference in its entirety. In one example, metal neutrals comprises include Ta, TaN, Ti, TiN, TiSiN, W, Ru or combinations thereof and the gas used to generate the sputtering species comprises Ar, He, Ne, Xe, N 2 , H 2 NH 3 , N 2 H 2 or combinations thereof. The liner material previously deposited is removed from the bottom of the trench along with any metal oxide that may be present on top surface 125 A of stud contact 120 (or any core conductor as illustrated in FIGS. 5 and 6 ). When sputtering is stopped but metal neutral deposition continued, a new layer of liner 190 is formed to replace that which was removed.
[0032] FIGS. 2A through 2C are cross-sectional views illustrating process steps for fabricating an interconnect structure according to the first embodiment of the present invention. FIG. 2A continues from FIG. 1H . In FIG. 2A , a core conductor 210 is formed on top of liner 190 . In one example core conductor 210 comprises Al, AlCu, Cu, W, Ag, Au or combinations thereof. In the example of core conductor 210 being copper, a thin copper layer is evaporated or deposited and then a thicker layer of copper is electroplated.
[0033] The thickness of core conductor 210 is sufficient to completely fill trenches 160 , 175 and 180 .
[0034] In FIG. 2B , a chemical-mechanical-polish (CMP) process is performed to co-planarize a top surface 145 A of dielectric layer 135 , a top surface 215 of liner 190 and a top surface 220 of core conductor 210 . After the CMP process, a damascene wire 225 and a dual damascene wire 230 having with an integral damascene via 235 are formed.
[0035] In FIG. 2C , conductive diffusion barrier caps 240 are selectively formed on top surface 220 of core conductor 210 . In one example, barrier caps 240 comprises CoWP, CoSnP, CoP and Pd or combinations thereof. In one example caps 240 are about 5 nm to about 80 nm thick. In one example, caps 240 are diffusion barriers to the material(s) of core conductor 210 . In one example, caps 240 is a diffusion barrier to copper In one example, caps 240 are formed by a process that includes electroless plating. Methods of forming CoWP, CoSnP, CoP and Pd layers are disclosed in U.S. Pat. No. 5,695,810 to Bubin et al, issued on Dec. 9, 1997 and U.S. Pat. No. 6,342,733 to Hu et al., issued on Jan. 29, 2002 which are hereby incorporated by reference in their entireties. Barrier caps 240 are in direct physical contact with top surface 220 of core conductor 210 .
[0036] FIGS. 3A through 3E are cross-sectional views illustrating process steps for fabricating an interconnect structure according to the second embodiment of the present invention. FIG. 3A continues from FIG. 1H . In FIG. 3A a dielectric liner 245 is formed on all exposed surfaces of liner 190 . In one example, dielectric liner 245 may comprise, for example, silicon dioxide (SiO 2 ), silicon nitride (Si 3 N 4 ), silicon carbide (SiC), silicon oxy nitride (SiON), silicon oxy carbide (SiOC), hydrogen doped silica glass (SiCOH), plasma-enhanced silicon nitride (PSiN x ) or NBLoK (SiC(N,H)) or combinations thereof.
[0037] In one example dielectric liner 245 is about 5 nm to about 100 nm thick. Dielectric liner 245 may be formed, for example by CVD or ALD.
[0038] In FIG. 3B , a directional etch process (such as an RIE) is performed to remove dielectric liner 245 from horizontal surfaces of liner 190 disposed on bottom surfaces of trenches 160 . 175 and 180 . The directional etch process may be followed by a simultaneous sputter etch and liner deposition as metal neutrals process as described supra, in reference to FIG. 1H .
[0039] In FIG. 3C , core conductor 210 is formed as described supra ion reference to FIG. 2A . The thickness of core conductor 210 is sufficient to completely fill trenches 160 , 175 and 180 .
[0040] In FIG. 3D , a CMP process is performed to co-planarize top surface 145 A of dielectric layer 135 , top surface 215 of liner 190 , top surface 220 of core conductor 210 and a top surface 250 of dielectric liner 245 . After the CMP process, a damascene wire 255 and a dual damascene wire 260 having with an integral damascene via 265 are formed.
[0041] In FIG. 3E , caps 240 are selectively formed on top surface 220 of core conductor 210 . Caps 240 are in direct physical contact with and completely covers top surface 220 of core conductor 210 .
[0042] FIG. 4 is a cross-sectional view illustrating multiple wiring levels fabricated according to the first embodiment of the present invention. In FIG. 4 , an interlevel dielectric layer 270 containing a damascene wire 275 and dual damascene wire 280 having with an integral damascene via 285 is formed over dielectric layer 135 (which can also be considered an interlevel dielectric layer). An interlevel dielectric layer 290 containing a dual damascene wire 295 with an integral damascene via 300 and dual damascene wire 305 having with an integral damascene via 310 is formed over interlevel dielectric layer dielectric layer 270 . Interlevel dielectric layers 270 and 275 are similar to dielectric layer 135 . Damascene wire 275 is similar to damascene wire 225 and dual damascene wires 280 , 295 and 305 with respective integral vias 285 , 300 and 310 are similar to dual damascene wire 230 and integral via 235 . Caps 240 A and 240 B are similar to caps 240 . While three wiring levels are illustrated in FIG. 4 , any number of similar wiring levels may be so stacked. Damascene wires and vias and dual damascene wires and vias having structures of the second embodiment of the present invention may be similarly formed in stacked interlevel dielectric layers.
[0043] FIG. 5 is a cross-sectional view illustrating multiple wiring levels fabricated with additional diffusion barriers applicable to the first and the second embodiments of the present invention. FIG. 5 is similar to FIG. 4 with the difference that a dielectric layer 135 A includes dielectric layer 135 and a dielectric diffusion barrier 315 , an interlevel dielectric layer 270 A includes dielectric layer 270 and a dielectric diffusion barrier layer 320 and an interlevel dielectric layer 290 A includes dielectric layer 290 and a dielectric diffusion barrier layer 325 . Diffusion barrier 315 is formed between dielectric layer 135 and interlevel dielectric layer 275 , diffusion barrier 320 is formed on top of interlevel dielectric layer 275 . Diffusion barriers 315 , 320 and 325 are similar to diffusion barrier 110 . In one example, diffusion barriers 315 , 320 and 325 are diffusion barriers to materials contained in wires 225 , 230 , 275 , 280 , 295 and 305 . In one example, diffusion barriers 315 , 320 and 325 are diffusion barriers to copper. While three wiring levels are illustrated in FIG. 5 , any number of similar wiring levels may be so stacked. Damascene wires and vias and dual damascene wires and vias having structures of the second embodiment of the present invention may be similarly formed in stacked interlevel dielectric layers.
[0044] Thus, the present invention provides improved diffusion barrier capped interconnect structures.
[0045] The description of the embodiments of the present invention is given above for the understanding of the present invention. It will be understood that the invention is not limited to the particular embodiments described herein, but is capable of various modifications, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, it is intended that the following claims cover all such modifications and changes as fall within the true spirit and scope of the invention.
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A damascene wire and method of forming the wire. The method including: forming a mask layer on a top surface of a dielectric layer; forming an opening in the mask layer; forming a trench in the dielectric layer where the dielectric layer is not protected by the mask layer; recessing the sidewalls of the trench under the mask layer; forming a conformal conductive liner on all exposed surface of the trench and the mask layer; filling the trench with a core electrical conductor; removing portions of the conductive liner extending above the top surface of the dielectric layer and removing the mask layer; and forming a conductive cap on a top surface of the core conductor. The structure includes a core conductor clad in a conductive liner and a conductive capping layer in contact with the top surface of the core conductor that is not covered by the conductive liner.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to methods and apparatus for drilling with top drive systems. Particularly, the invention relates to methods and apparatus for adapting a top drive for use with running casing. More particularly still, the invention relates to a torque head for engaging with a tubular and rotating the same.
[0003] 2. Description of the Related Art
[0004] In well completion operations, a wellbore is formed to access hydrocarbon-bearing formations by the use of drilling. Drilling is accomplished by utilizing a drill bit that is mounted on the end of a drill support member, commonly known as a drill string. To drill within the wellbore to a predetermined depth, the drill string is often rotated by a top drive or rotary table on a surface platform or rig, or by a downhole motor mounted towards the lower end of the drill string. After drilling to a predetermined depth, the drill string and drill bit are removed and a section of casing is lowered into the wellbore. An annular area is thus formed between the string of casing and the formation. The casing string is temporarily hung from the surface of the well. A cementing operation is then conducted in order to fill the annular area with cement. Using apparatus known in the art, the casing string is cemented into the wellbore by circulating cement into the annular area defined between the outer wall of the casing and the borehole. The combination of cement and casing strengthens the wellbore and facilitates the isolation of certain areas of the formation behind the casing for the production of hydrocarbons.
[0005] It is common to employ more than one string of casing in a wellbore. In this respect, one conventional method to complete a well includes drilling to a first designated depth with a drill bit on a drill string. Then, the drill string is removed and a first string of casing is run into the wellbore and set in the drilled out portion of the wellbore. Cement is circulated into the annulus behind the casing string and allowed to cure. Next, the well is drilled to a second designated depth, and a second string of casing, or liner, is run into the drilled out portion of the wellbore. The second string is set at a depth such that the upper portion of the second string of casing overlaps the lower portion of the first string of casing. The second string is then fixed, or “hung” off of the existing casing by the use of slips which utilize slip members and cones to wedgingly fix the second string of casing in the wellbore. The second casing string is then cemented. This process is typically repeated with additional casing strings until the well has been drilled to a desired depth. Therefore, two run-ins into the wellbore are required per casing string to is set the casing into the wellbore. In this manner, wells are typically formed with two or more strings of casing of an ever-decreasing diameter.
[0006] As more casing strings are set in the wellbore, the casing strings become progressively smaller in diameter in order to fit within the previous casing string. In a drilling operation, the drill bit for drilling to the next predetermined depth must thus become progressively smaller as the diameter of each casing string decreases in order to fit within the previous casing string. Therefore, multiple drill bits of different sizes are ordinarily necessary for drilling in well completion operations.
[0007] Another method of performing well completion operations involves drilling with casing, as opposed to the first method of drilling and then setting the casing. In this method, the casing string is run into the wellbore along with a drill bit for drilling the subsequent, smaller diameter hole located in the interior of the existing casing string. The drill bit is operated by rotation of the drill string from the surface of the wellbore. Once the borehole is formed, the attached casing string may be cemented in the borehole. The drill bit is either removed or destroyed by the drilling of a subsequent borehole. The subsequent borehole may be drilled by a second working string comprising a second drill bit disposed at the end of a second casing that is of sufficient size to line the wall of the borehole formed. The second drill bit should be smaller than the first drill bit so that it fits within the existing casing string. In this respect, this method requires at least one run-in into the wellbore per casing string that is set into the wellbore.
[0008] It is known in the industry to use top drive systems to rotate a drill string to form a borehole. Top drive systems are equipped with a motor to provide torque for rotating the drilling string. The quill of the top drive is typically threadedly connected to an upper end of the drill pipe in order to transmit torque to the drill pipe. Top drives may also be used in a drilling with casing operation to rotate the casing.
[0009] In order to drill with casing, most existing top drives require a threaded crossover adapter to connect to the casing. This is because the quill of the top drives is not sized to connect with the threads of the casing. The crossover adapter is design to alleviate this problem. Typically, one end of the crossover adapter is designed to connect with the quill, while the other end is designed to connect with the casing.
[0010] However, the process of connecting and disconnecting a casing is time consuming. For example, each time a new casing is added, the casing string must be disconnected from the crossover adapter. Thereafter, the crossover must be threaded into the new casing before the casing string may be run. Furthermore, this process also increases the likelihood of damage to the threads, thereby increasing the potential for downtime.
[0011] There is a need, therefore, for methods and apparatus for coupling a casing to the top drive for drilling with casing operations. There is a further need for methods and apparatus for running casing with a top drive in an efficient manner. There is also a need for methods and apparatus for running casing with reduced damage to the casings.
SUMMARY OF THE INVENTION
[0012] The present invention generally relates to a method and apparatus for drilling with a top drive system. Particularly, the present invention relates to methods and apparatus for handling tubulars using a top drive system.
[0013] In one aspect, the present invention provides a tubular gripping member for use with a top drive to handle a tubular comprising a housing operatively connected to the top drive and a plurality of gripping elements radially disposed in the housing for engaging the tubular, wherein moving the housing relative the plurality of gripping elements causes the plurality of gripping members to engage the tubular.
[0014] In another aspect, the present invention provides a method of handling a tubular comprising providing a top drive operatively connected to a gripping head. The gripping head has a housing, a plurality of gripping elements radially disposed in the housing for engaging the tubular, and a plurality of engagement members movably disposed on each of the plurality of gripping elements. The method further includes disposing the tubular within the plurality of gripping elements, moving the housing relative to the plurality of gripping elements, engaging the tubular, and pivoting the plurality of engagement members.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] So that the manner in which the above recited features of the present invention, and other features contemplated and claimed herein, are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
[0016] FIG. 1 is a partial view of a rig having a top drive system according to aspects of the present invention.
[0017] FIG. 2 shows an exemplary torque head according to aspects of the present invention. As shown, the torque head is in a partially actuated position.
[0018] FIG. 2A is an exploded partial view of the torque head of FIG. 2 .
[0019] FIG. 3 is a perspective view of the gripping element of the torque head of FIG. 2 .
[0020] FIG. 4 is a perspective view of the torque head of FIG. 2 .
[0021] FIG. 5 shows the torque head of FIG. 2 in an unactuated position.
[0022] FIG. 6 shows the torque head of FIG. 2 in an actuated position.
[0023] FIG. 7 shows another embodiment of a torque head according to aspects of the present invention.
[0024] FIGS. 8 A-B are two different views of an exemplary gripping element for use with the torque head of FIG. 7 .
[0025] FIG. 9 is a cross-sectional view of another embodiment of a gripping element according to aspects of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] Aspects of the present invention provides a top drive adapter for gripping a casing for drilling with casing. The top drive adapter includes rotating unit for connection with the top drive to transfer torque. The top drive adapter also has a plurality of gripping elements disposed in a housing. Moving the housing axially relative to the plurality of gripping elements causes the gripping elements to apply an initial gripping pressure on the casing. The gripping elements have engagement members for contacting or gripping the casing. An axial load acting on the engagement members causes the engagement members to pivot axially and support the axial load.
[0027] FIG. 1 shows a drilling rig 10 applicable to drilling with casing operations or a wellbore operation that involves picking up/laying down tubulars. The drilling rig 10 is located above a formation at a surface of a well. The drilling rig 10 includes a rig floor 20 and a v-door 800 . The rig floor 20 has a hole 55 therethrough, the center of which is termed the well center. A spider 60 is disposed around or within the hole 55 to grippingly engage the casings 30 , 65 at various stages of the drilling operation. As used herein, each casing 30 , 65 may include a single casing or a casing string having more than one casing. Furthermore, aspects of the present invention are equally applicable to other types of wellbore tubulars, such as drill pipe.
[0028] The drilling rig 10 includes a traveling block 35 suspended by cables 75 above the rig floor 20 . The traveling block 35 holds the top drive 50 above the rig floor 20 and may be caused to move the top drive 50 axially. The top drive 50 includes a motor 80 which is used to rotate the casing 30 , 65 at various stages of the operation, such as during drilling with casing or while making up or breaking out a connection between the casings 30 , 65 . A railing system (not shown) is coupled to the top drive 50 to guide the axial movement of the top drive 50 and to prevent the top drive 50 from rotational movement during rotation of the casings 30 , 65 .
[0029] Disposed below the top drive 50 is a tubular gripping member such as a torque head 40 . The torque head 40 may be utilized to grip an upper portion of the casing 30 and impart torque from the top drive to the casing 30 . The torque head 40 may be coupled to an elevator 70 using one or more bails 85 to facilitate the movement of the casing 30 above the rig floor 20 . Additionally, the rig 10 may include a pipe handling arm 100 to assist in aligning the tubulars 30 , 65 for connection.
[0030] FIG. 2 illustrates a cross-sectional view of an exemplary torque head 40 according to aspects of the present invention. Because the torque head 40 is adapted to couple the top drive 50 to the casing 30 the torque head 40 includes a mandrel 103 coupled to a rotary unit 109 for connection to the top drive 50 . In this respect, the top drive 50 may rotate, raise, or lower the torque head 40 for drilling with casing. The mandrel 103 includes a load collar 113 for coupling one or more gripping elements 105 to the mandrel 103 . As shown in FIG. 2 , an upper portion of the gripping element 105 includes a recess 114 for engagement with the load collar 113 of the mandrel 103 . The gripping elements 105 are circumferentially disposed around the mandrel 103 .
[0031] A housing 104 surrounds the gripping elements 105 and ensures the gripping elements 105 remain coupled to the mandrel 103 . The housing 104 is actuatable by a hydraulic cylinder 110 disposed on the mandrel 103 : Particularly, an upper portion of the housing 104 is coupled to the piston 111 of the hydraulic cylinder 110 . Actuation of the piston 111 causes the housing 104 to move axially relative to the mandrel 103 .
[0032] The gripping elements 105 are adapted to engage and retain the casing 30 once the casing 30 is inserted into the housing 104 . As shown in FIG. 3 , the gripping elements 105 include an upper end having a recess 114 for coupling to the mandrel 103 and a lower end having one or more engagement members 106 . A width of the gripping elements 105 may be arcuate in shape such that the gripping elements 105 may be circumferentially disposed to form a substantially tubular structure to engage a tubular such as a casing or a pipe. FIG. 4 is a perspective view of the torque head 40 showing the gripping elements 105 circumferentially disposed inside the housing 104 .
[0033] Referring again to FIG. 3 , the gripping elements 105 include an arcuate interior surface 131 for engaging the tubular and an arcuate exterior surface 132 for engaging the housing 104 . In one embodiment, the interior surface 131 includes one or more slots 115 for receiving one or more engagement members 106 . Preferably, the engagement members 106 are pivotable within the slots 115 . Initially, the engagement members 106 are disposed at an upward angle in a direction towards the upper portion of the mandrel 103 . In other words, the distal end 161 of the engagement members 106 is higher than the proximal end 162 . More preferably, each engagement member 106 is set at the same angle. When the engagement members engage the casing string, the load of the casing string will cause the engagement members 106 to pivot in the slots 115 thereby carrying the casing string load. It is believed that this arrangement allows the engagement members 106 to carry an equal, partial load of the casing 30 . The engagement members 106 may be designed with any suitable contact surface as is known to a person of ordinary skill in the art. For example, the contact surface may be a smooth surface or a tooth structure to increase the load carrying capacity.
[0034] The exterior surface 132 of the gripping elements 105 is adapted to interface with the interior surface of the housing 104 to move the gripping elements 105 radially relative to the housing 104 . In one embodiment, the gripping elements 105 may interface with the housing 104 using a complementary key and groove system. As shown in FIGS. 3 and 4 , the lower, exterior portion of the gripping elements 105 includes one or more keys 108 formed thereon. The keys 108 are adapted to fit in a complementary groove 116 formed on the inner surface of the housing 104 when the torque head 40 is in the unactuated or “unlocked” position, as illustrated in FIG. 5 . Referring to FIG. 2 , the housing 104 includes one or more keys 117 formed between the grooves 116 . The keys 117 of the housing 104 reside between the keys 108 of the gripping elements 105 when the torque head 40 is in the unlocked position.
[0035] In one aspect, the housing 104 may be actuated to move the keys 108 of the housing 104 and the keys 117 of the gripping element 105 into an actuated or locking position. FIG. 2 shows the keys 108 , 117 in a partially locked position. To this end, the keys 108 of the gripping elements 105 include an upper surface 121 and an abutment surface 123 . The upper surface 121 of the keys 108 may be inclined downward to facilitate the movement of the keys 108 of the gripping elements 105 out of the grooves 116 of the housing 104 . Similarly, the keys 117 of the housing 104 include a lower surface 122 and an abutment surface 124 . The lower surface 122 is adapted to engage the upper surface of the key 108 of the gripping element 105 as the housing 104 is lowered. Due the incline of the upper surface 121 , the gripping elements 105 move radially inward to engage the casing 30 while the housing 104 is lowered.
[0036] The abutment surfaces 123 , 124 are adapted to provide a self locking function. In one embodiment, the abutment surface 123 of the gripping elements 105 is inclined slightly downward, and the abutment surface 124 of the housing 104 has a complementary incline. When the two abutment surfaces 123 , 124 engage, the incline causes the gripping elements 105 to move radially toward the axial center to establish its grip on the casing 30 . Preferably, the abutment surface 122 of the gripping elements 105 is angled at about ten degrees or less relative to a vertical axis. More preferably, the abutment surface 122 of the gripping elements 105 is inclined at about seven degrees or less relative to a vertical axis.
[0037] Referring to FIG. 1 , a casing 30 is shown as it is being brought up to the rig 10 for connection with a casing string 65 . The casing string 65 , which was previously drilled into the formation (not shown) to form the wellbore (not shown), is shown disposed within the hole 55 in the rig floor 20 . The casing string 65 may include one or more joints or sections of casing threadedly connected to one another. The casing string 65 is shown engaged by the spider 60 . The spider 60 supports the casing string 65 in the wellbore and prevents the axial and rotational movement of the casing string 65 relative to the rig floor 20 . As shown, a threaded connection of the casing string 65 , or the box, is accessible from the rig floor 20 .
[0038] In FIG. 1 , the top drive 50 , the torque head 40 , and the elevator 70 are shown positioned proximate the rig floor 20 . The casing 30 may initially be disposed on the rack 25 , which may include a pick up/lay down machine. The lower portion of the casing 30 includes a threaded connection, or the pin, which may mate with the box of the casing string 65 . The elevator 70 is shown engaging an upper portion of the casing 30 and ready to be hoisted by the cables 75 suspending the traveling block 35 . The elevator 70 may be used to transport the casing 30 from a rack 25 or a pickup/lay down machine to the well center. The elevator 70 may include any suitable elevator known to a person of ordinary skill in the art. The elevator defines a central opening to accommodate the casing 30 . The bails 85 interconnect the elevator 70 to the torque head 40 and are pivotable relative to the torque head 40 .
[0039] While the casing is moved towards the well center, the pipe handling arm 100 is actuated to guide and align the casing 30 with the casing string 65 for connection therewith. A suitable pipe handling arm is disclosed in U.S. Pat. No. 6,591,471 issued to Hollingsworth on Jul. 15, 2003, assigned to the assignee of the present invention and incorporated by reference herein in its entirety. Another suitable pipe handling arm is disclosed in U.S. patent application Ser. No. 10/382,353, filed on Mar. 5, 2003, entitled “Positioning and Spinning Device,” which application is assigned to the same assignee of the present invention and incorporated by reference herein in its entirety. An exemplary pipe handling arm 100 includes a gripping member for engaging the casing 30 during operation. The pipe handling arm 100 is adapted and designed to move in a plane substantially parallel to the rig floor 20 to guide the casing 30 into alignment with the casing 65 in the spider 60 .
[0040] After the casing is guided into alignment by the pipe handling arm 100 , the torque head 40 is lowered relative to the casing 30 and positioned around the upper portion of the casing 30 . As the casing 30 is inserted into the torque head 40 , the coupling 32 of the casing 30 forces the gripping elements 105 to expand radially. In this respect, the keys 108 of the gripping elements 105 move into the grooves 116 of the housing 104 . FIG. 5 shows the casing 30 inserted into the torque head 40 . It can be seen that coupling 32 is located above the gripping elements 105 .
[0041] To grip the casing 30 , the hydraulic cylinder 110 is actuated to move the piston 111 downward. In turn, the housing 104 is lowered relative to the gripping elements 105 . Initially, the lower surface 122 of the housing 104 encounters the upper surface 121 of the gripping elements 105 . The incline of the upper and lower surfaces 121 , 122 facilitate the movement of the gripping elements 105 out of the groove 116 and the lowering of the housing 104 . Additionally, the incline also causes the gripping elements 105 to move radially to apply a gripping force on the casing 30 . As shown in FIG. 2 , the housing 104 has been lowered relative to the gripping elements 105 . Additionally, the keys 108 of the gripping elements 105 have moved out of the groove 116 . The housing 104 is lowered until the abutment surfaces 123 , 124 of the keys 108 , 117 substantially engage each other, as shown in FIG. 6 . It can be seen in FIG. 6 that the piston 111 is fully actuated.
[0042] During drilling operation, the casing string load will pull the casing 30 down. Due to this movement, the engagement members 106 will pivot in the slot 115 of the gripping elements 105 to clamp the casing 30 . In this respect, the engagement members 106 will work as an axial free running drive. Moreover, because the engagement members 106 are all set the same angle, each of the engagement members 106 carries an equal amount of the casing string weight. Additionally, the radial clamping force will be balanced by the housing 104 . In one embodiment, when the key angle between the key 117 of the housing 104 and the key 108 of the gripping element 105 is less than seven degrees, the radial force will be distributed across the housing 104 .
[0043] When the casing string load is removed, such as actuating the spider to retain the casing string, the engagement members 106 will immediately release the radial force exerted on the casing 30 . Thereafter, the piston is deactuated to raise the housing 104 relative to the gripping elements 105 . The casing 30 may be removed when the keys 108 of the gripping elements 105 return to their respective grooves 116 .
[0044] In another aspect, the torque head 40 may be used to transfer torque. In this respect, an appropriate hydraulic cylinder may be selected to apply a sufficient force to clamp the casing 30 .
[0045] FIG. 7 presents another embodiment of a torque head 240 according to aspects of the present invention. The torque head 240 includes a rotary unit 209 for connection with the top drive 50 and transmitting torque. A mandrel 203 extends below the rotary unit 209 and is coupled to an upper end of a tubular body 235 using a spline and groove connection 237 . The spline and groove connection 237 allows the body 235 to move axially relative to the mandrel 203 while still allowing torque to be transmitted to rotate the body 235 . The lower portion of the body 235 includes one or more windows 240 form through a wall of the body 235 . The windows 240 are adapted to contain a gripping element 205 . Preferably, eight windows 240 are formed to contain eight gripping elements 205 .
[0046] The outer surface of the body 235 includes a flange 242 . One or more compensating cylinders 245 connect the flange 242 to the rotary unit. In this respect, the compensating cylinders 245 control the axial movement of the body 235 . The compensating cylinder 245 is particularly useful during makeup or breakout of tubulars. For example, the compensating cylinder 245 may allow the body 235 to move axially to accommodate the change in axial distance between the tubulars as the threads are made. An exemplary compensating cylinder is a piston and cylinder assembly. The piston and cylinder assembly may be actuated hydraulically, pneumatically, or by any other manner known to a person of ordinary skill in the art. A suitable alternate compensating cylinder is disclosed in U.S. Pat. No. 6,056,060, which patent is herein incorporated by reference in its entirety and is assigned to the same assignee of the present invention.
[0047] A housing 204 is disposed around the windows 240 of the body 235 . The housing 204 is coupled to the flange 242 using a one or more actuating cylinders 210 . In this respect, the housing 204 may be raised or lowered relative to the body 235 . The interior of the housing 204 includes a key and groove configuration for interfacing with the gripping element 205 . In one embodiment, the key 217 includes an inclined abutment surface 224 and an inclined lower surface 222 . Preferably, the transition between the lower surface 222 and the abutment surface 224 is curved to facilitate lowering of the housing 204 relative to the body 235 .
[0048] A gripping element 205 is disposed in each of the windows 240 in the body 235 . In one embodiment, the gripping element 205 has an exterior surface adapted to interface with the key and groove configuration of the housing 204 , as shown in FIGS. 7 and 8 . Particularly, keys 208 are formed on the exterior surface and between the keys 208 are grooves that may accommodate the key 217 of the housing 204 . The keys 208 of the gripping element 205 include an upper surface 221 and an abutment surface 223 . The upper surface 221 is inclined downward to facilitate movement of the keys 217 of the housing 204 . The abutment surface 223 has an incline complementary to the abutment surface 224 of the housing 204 . A collar 250 extends from the upper and lower ends of the exterior surface of the gripping elements 205 . The collars 250 engage the outer surface of the body 235 to limit the inward radial movement of the gripping elements 205 . Preferably, a biasing member 255 is disposed between the collar and the body 235 to bias the gripping element 205 away from the body 235 . In one embodiment, the biasing member 255 may be a spring.
[0049] The interior surface of the gripping element 205 includes one or more engagement members 206 . In one embodiment, each engagement member 206 is disposed in a slot 215 formed in the interior surface of the gripping element 205 . Preferably, the engagement members 206 are pivotable in the slot 215 . The portion of the engagement member 206 disposed in the interior of the slot 215 may be arcuate in shape to facilitate the pivoting motion. The tubular contact surface of the engagement members 257 may be smooth or rough, or have teeth formed thereon.
[0050] In another aspect, the gripping element 205 may include a retracting mechanism to control movement of the engagement members 206 . In one embodiment, an axial bore 260 is formed adjacent the interior surface of the gripping element 205 . An actuating rod 265 is disposed in the bore 260 and through a recess 267 of the engagement members 206 . The actuating rod 265 includes one or more supports 270 having an outer diameter larger than the recess 267 of the engagement members 206 . A support 270 is positioned on the actuating rod 265 at a level below each engagement member 206 such that the engagement members 206 rest on their respective support 270 .
[0051] A biasing member 275 coupled to the actuating rod 265 is disposed at an upper end of the bore 260 . In the relaxed position, the biasing member 275 biases the actuating rod 265 in the upward position. In this respect, the actuating rod 265 places the engagement members 206 in the retracted position, or pivoted upward position, as shown in FIGS. 8 A-B. When the biasing member 275 is compressed, the actuating rod 265 is placed in the downward position. In this respect, the engagement members 206 are in the engaged position, or pivoted downward such that it is relatively closer to a horizontal axis than the retracted position.
[0052] In operation, the casing 230 is inserted into the body 235 of the torque head 240 . At this point, the keys 208 of the gripping element 205 are disposed in their respective groove 216 in the housing 204 . Additionally, the actuating rod 265 is in the upward position, thereby placing the engagement members 206 in the retracted position. As the casing 230 is inserted into the torque head 240 , the coupling moves across the gripping elements 205 and forces the gripping elements 205 to move radially outward. After the coupling moves past the gripping elements 205 , the biasing members 255 bias the gripping elements 205 to maintain engagement with the casing 30 .
[0053] Once the casing 230 is received in the torque head 240 , the actuating cylinder 210 is activated to lower the housing 204 relative to the body 235 . Initially, the lower surface 222 of the housing 204 encounters the upper surface 221 of the gripping elements 205 . The incline of the upper and lower surfaces 221 , 222 facilitate the movement of the gripping elements 205 out of the groove 216 and the lowering of the housing 204 . Additionally, the incline also causes the gripping elements 205 to move radially to apply a gripping force on the casing 30 . Preferably, the gripping elements 205 move radially in a direction substantially perpendicular to the vertical axis of the casing 30 . The housing 204 continues to be lowered until the abutment surfaces 223 , 224 of the keys 208 , 217 substantially engage each other, as shown in FIG. 7 . During the movement of the housing 204 , the biasing members 255 between the collars 250 and the body 235 are compressed. Additionally, the weight of the casing 30 may force the engagement members 205 to pivot slightly downward, which, in turn, causes the actuating rod 265 to compress the biasing member 275 . In this respect, a radial clamping force is applied to support the axial load of the casing 30 .
[0054] To makeup the casing 230 to the casing string 65 , the top drive 50 may be operated to provide torque to rotate the casing 230 relative to the casing string 65 . During makeup, the compensating cylinder 245 is activated to compensate for the change in axial distance as a result of the threaded engagement. In this respect, the body 235 is allowed to move axially relative to the mandrel 203 using the spline and groove connection 237 .
[0055] During drilling operation, the entire casing string load is supported by the torque head 240 . Particularly, the heavier casing string load further pivots the engagement members 206 in the slot 215 of the gripping elements 205 . In this respect, the casing string load is distributed among the engagement members 206 , thereby allowing the torque head 240 to work as an axial free running drive. Moreover, because the engagement members 206 are all set the same angle, each of the engagement members 206 carries an equal amount of the casing string weight. Additionally, the radial clamping force will be balanced by the housing 204 . In one embodiment, when the angle between the key 217 of the housing 204 and the key 208 of the gripping element 205 is less than seven degrees, the radial force will be distributed across the housing 204 . In this manner, the torque head according to aspects of the present invention may be used to connect tubulars and generally used to perform tubular handling operations.
[0056] In another embodiment, the gripping element 305 may include a collar 350 on either side, instead of the upper or lower end. As shown in FIG. 9 , a biasing member 355 is disposed between two adjacent gripping elements 305 . Additionally, the biasing member 355 is between the side collars 350 and the body 335 . In this respect, the biasing member 355 may be used to control the position of the gripping elements 305 . In one embodiment, the biasing member 355 may comprise one or more retracting blade springs.
[0057] In another aspect, the torque head 40 may optionally employ a circulating tool 280 to supply fluid to fill up the casing 30 and circulate the fluid. The circulating tool 220 may be connected to a lower portion of the mandrel 203 and at least partially disposed in the body 235 . The circulating tool 280 includes a first end and a second end. The first end is coupled to the mandrel 203 and fluidly communicates with the top drive 50 . The second end is inserted into the casing 30 . A cup seal 285 is disposed on the second end interior to the casing 30 . The cup seal 285 sealingly engages the inner surface of the casing 30 during operation. Particularly, fluid in the casing 30 expands the cup seal 285 into contact with the casing 30 . The circulating tool 280 may also include a nozzle 288 to inject fluid into the casing 30 . The nozzle 288 may also act as a mud saver adapter for connecting a mud saver valve (not shown) to the circulating tool 280 .
[0058] It addition to casing, aspects of the present invention are equally suited to handle tubulars such as drill pipe, tubing, and other types of tubulars known to a person of ordinary skill in the art. Moreover, the tubular handling operations contemplated herein may include connection and disconnection of tubulars as well as running in or pulling out tubulars from the well.
[0059] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
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The present invention generally relates to a method and apparatus for drilling with a top drive system. In one aspect, the present invention provides a tubular gripping member for use with a top drive to handle a tubular comprising a housing operatively connected to the top drive and a plurality of gripping elements radially disposed in the housing for engaging the tubular, wherein moving the housing relative the plurality of gripping elements causes the plurality of gripping members to engage the tubular.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of an earlier filing date from U.S. Provisional Application Ser. No. 61/159,663 filed Mar. 12, 2009, the entire disclosure of which is incorporated herein by reference.
BACKGROUND
[0002] In industries concerned with actions taken within earth formations, it is often necessary to anchor tools needed for a plethora of possible operations. Anchors come in many different forms and constructions and each has its strengths and weaknesses and hence each type tends to be favored for a relatively specific class of applications. While existing anchors work well for their intended purpose and are generally reliable, the costs of operational inconsistencies in downhole applications are significant. The art is therefore consistently seeking and interested in alternative constructions that improve reliability.
SUMMARY
[0003] An anchor system includes an anchoring device and at least one of a restriction indicator and a load isolation device in operable communication with the anchoring device.
[0004] A method for setting of an anchoring system includes protecting an outer gage diameter of an anchoring device with a restriction indicator having a gage diameter greater than any gage diameter of the anchoring device; and configuring the restriction indicator to hold a selected amount of string weight in the event that the system contacts a restriction in a borehole in which the system is being run.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Referring now to the drawings wherein like elements are numbered alike in the several Figures:
[0006] FIG. 1 is a perspective view of an anchor system;
[0007] FIG. 2 is a cross section view of the anchor illustrated in FIG. 1 taken along section line 2 - 2 ;
[0008] FIG. 3 is a schematic enlarged view of the area proximate the enlarged ends 58 ;
[0009] FIG. 4 is a representation similar to that of FIG. 2 with the system modified to set based upon landing at a preinstalled structure in a borehole; and
[0010] FIG. 5 is a schematic illustration of a hydraulic embodiment of the system disclosed herein.
DETAILED DESCRIPTION
[0011] Referring to FIG. 1 , an anchor system 10 is illustrated in perspective view. A mid to uphole portion of the drawing, identified by bracket 12 , depicts an anchoring device that is commercially available from Baker Hughes Incorporated under Product Family H15054. Downhole of this portion (to the right in the Figure) is a new configuration providing significantly improved function to the H15054 product. The new configuration may include either or both of a restriction indicator 14 and a load isolation device 46 , which in one embodiment is a collet device and in other embodiments may be a spring, j-slot, shear ring, parting ring, body lock ring, burst disk or other release configuration capable of selectively permitting setting of the anchor. Each has a separate function and hence can be used independently with the related benefit to an anchor system using the same. Together, additional benefit is achieved. An embodiment that includes both the restriction indicator 14 and the load isolation device 46 is specifically illustrated. It is to be understood that either of these features could be deleted from the drawing such that the drawing illustrates the other configuration alone.
[0012] Referring to FIG. 2 , the restriction indicator 14 is to be configured to have a gage surface 20 that is of greater dimension than any other portion of the system 10 . It is to be appreciated that the surface 20 is also axially relatively short and the restriction indicator 14 further includes a frustoconical section 22 . These attributes of the restriction indicator 14 work together to ensure that the restriction indicator is the most likely component of the system 10 to experience contact at a restriction within the borehole in which the system 10 is run. The configuration also ensures that in the event that a contact occurs, it is relatively easy to dislodge the system because of the relatively narrow band of material at surface 20 that can be lodged. When the restriction indicator 14 is employed, a relatively small frictional interaction is usually all that needs to be overcome to release the system from a restriction. This is further discussed hereunder.
[0013] Restriction indicator 14 presents a relatively small gage surface 20 that is exposed to and might encounter a restriction contact. In addition, because of the short axial length of the surface 20 and the configuration of the frustocone 22 , if a restriction is encountered, it is a relatively easy affair to pull the system 10 back uphole and out of the restriction. Further, the restriction indicator provides a warning signal to an operator in that the restriction indicator 14 is releasably affixed by a release member 26 to a lower cone 28 which itself is releasably affixed by a another release member 56 (shear screw(s), parting ring, body lock ring, collet, etc.) to a shear sleeve 30 . In one embodiment, the release member 26 is a shear ring, but it will be understood that other release members, such as shear screw(s), parting ring, body lock ring, collet, etc., could be substituted. The release member 26 provides a signal to an operator indicative of a restriction by holding some selected amount of weight and then releasing causing a slack off in weight on the derrick (not shown) at surface and then a return of the weight, or in other words a spike (except in the negative direction with respect to load). The amplitude of the signal is dictated by the release value of the release member 26 and can be adjusted during manufacture of the system 10 .
[0014] Referring now to the load isolation device 46 , this feature provides the function of ensuring that the anchor system 10 sets only at a selected location such as the bottom of a borehole in which the anchor is to be used or at a landing profile (discussed hereunder as alternative embodiment) intended to cause the actuation. It ensures this by presenting a significantly lesser gage diameter than other components of the system 10 . This helps in the function of the system 10 in that it predisposes the actuation of the system 10 at the selected location such as the bottom of the borehole or at a landing profile, as is intended. Because the collet is of significantly smaller gage diameter, the likelihood of being actuated by a restriction is consequently smaller. The collet 46 is releasably secured by a collet release member 48 (shear screw(s), parting ring, body lock ring, collet, etc) to the shear sleeve 30 to prevent actuations caused merely by drag of the collet 46 along borehole structures during running. It is to be appreciated that in one embodiment the collet 46 extends downhole (to the right in the drawing) of the shear sleeve 30 by enough distance to allow the collet actuation shoulder 50 to make contact with and actuate a lower cone actuation shoulder 52 . Upon contact of the collet with the bottom of the hole (not shown), in the embodiment of FIGS. 1 and 2 , load is built upon the collet release member 48 until a selected value of the release member is reached and surpassed. At that point the load isolation device 46 will move in an uphole direction relative to the rest of the system 10 . In fact, the load isolation device 46 has simply stopped moving downhole while the rest of the system 10 continues moving downhole. The load isolation device 46 moves closer to the lower cone 28 until actuation shoulder 50 on the load isolation device 46 makes contact with the actuation shoulder 52 of the lower cone 28 . In this position, the shear sleeve 30 is still extending for a lesser distance downhole than that of the load isolation device 46 thereby allowing the load isolation device 46 to provide a load to lower cone 28 and effectuate setting of the system 10 .
[0015] Collet fingers 54 function to help prevent unintended actuation through the restriction indicator 14 , pursuant to a restriction, by transferring from the lower cone 28 to the shear sleeve 30 the load occasioned by contact between shoulder 32 and shoulder 34 , which is otherwise resisted only by setting release member 56 . The fingers 54 include enlarged ends 58 to interact with the shear sleeve 30 at groove 62 and lower cone 28 through undercut 60 therein, in which the ends 58 are positioned. In this configuration, unintended actuation due to the system encountering a restriction with restriction indicator 14 requires release of the release member 26 , movement of the restriction indicator 14 to load shoulders 32 and 34 . At this point, however, the load being transferred between load shoulders 32 and 34 will be transmitted axially along the lower cone, and will then load into the enlarged ends 58 of the collet fingers (through load shoulder B). The enlarged ends 58 of the collet fingers will then be placed into compression against load shoulder A. While this load is applied, the setting of the anchor 10 is prevented (see FIG. 3 ). Thus the probability of achieving the intended setting is enhanced.
[0016] In another embodiment, illustrated in FIG. 4 , a system 110 is configured to actuate based upon landing in a preinstalled structure 164 . Structure 164 may be for example a tubular of some kind that has been previously placed in the borehole and is in some way held in place, perhaps by an anchoring system of some kind. The structure is configured at an uphole end thereof to interact selectively with a load isolation device 146 . This removes the requirement of the previously described embodiment that the load isolation device 46 extend downhole of the shear sleeve 30 . In the illustrated embodiment of FIG. 4 , the shear sleeve 130 extends downhole of the load isolation device 146 and thereby offers additional protection thereto with regard to unintentionally engaging the load isolation device 146 , shearing the release member 148 , and setting the system 110 while running downhole. The structure 164 is configured to receive the shear sleeve 130 thereby aligning the system 110 in the borehole. After the shear sleeve 130 is received in the structure 164 , actuation end 166 will come into loaded contact with collet end 168 and cause actuation of the system 110 similarly to that described above for the embodiment of FIGS. 1-3 . It will be understood that in one embodiment as shown, the ends 166 and 168 are profiled complementarily to one another. This profile may be angled as shown or orthogonal, or the surface may have another shape that aids in orientation of the system 110 , for example.
[0017] Referring now to FIG. 5 , another alternate embodiment of the system 210 is illustrated. In this embodiment the system 210 is actuated hydraulically and requires no set down weight on bottom or any structure. This embodiment may be located anywhere in the borehole that is desired. The system 210 includes a bottom sub 270 that replaces the shear sleeve 30 and 130 of the previous embodiments. The bottom sub 270 includes a hydraulic pathway 272 therein that feeds a port 274 . Hydraulic pressure is provided to this port 274 by string pressure that may be applied from the surface or other remote location. It is also possible for the system 210 to carry its own pressure source which may be in the form of a selectively openable chamber, a pump, etc. for example. Upon pressurization of the port 274 , fluid pressure within a hydraulic chamber 276 , defined in part by the collet 246 and in part by the sub 270 , is contained therein by seals 278 , which may be for example, o-rings. The increasing pressure in hydraulic chamber 276 ultimately will cause release of the release member 248 thereby facilitating movement of the collet 246 toward lower cone 28 . This movement is analogous to the movement of the load isolation device 46 in the first described embodiment and causes similar consequent actions of the system 210 .
[0018] While one or more embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation.
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An anchor system includes an anchoring device and at least one of a restriction indicator and a load isolation device in operable communication with the anchoring device and method.
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FIELD
[0001] This invention relates to the field of integrated circuit fabrication. More particularly, this invention relates to identifying, acquiring, storing, and using processing data that is generated during integrated circuit fabrication.
BACKGROUND
[0002] Modern integrated circuits are enormously complex devices. Typically, even the smallest fluctuations in the materials, processes, and designs by which they are fabricated are sufficient to either degrade the operation of the device so malformed or render it completely inoperable. Because of this, there has been a tremendous effort to monitor and control the nearly innumerable count of parameters which contribute to the success of the fabrication process. The heart of such efforts has traditionally been the statistical process control engine.
[0003] Statistical process control works by receiving a stream of data in regard to a given parameter. The parameter stream is plotted, typically in an order dependent manner, although other plotting bases can also be used. The parameter may be plotted in its raw form, or in a manipulated form. The parameter stream is also mathematically manipulated to determine desired statistical values in regard to the parameter. These desired statistical values enable one to quickly detect, and often to predict, one or more of a variety of different problems with the parameter. When such a problem is detected, an investigation can be made and corrective actions can be implemented. Thus, such statistical process control has been of great benefit to the integrated circuit fabrication industry, as implemented on a wide variety of parameters.
[0004] Because of the great utility of statistical process control, there has been a concerted effort to provide as much information to the control engines as possible. For this and other reasons, equipment manufacturers have offered data collecting and reporting modules for their equipment, which modules collect some of the processing data and send it to centralized databases. Such data is generally referred to as engineering data, and such collection systems are generally referred to as engineering data collection systems.
[0005] However, there is a great amount of data that cannot be automatically gathered by such engineering data collection systems, either because equipment manufacturers have not provided the capability to do so, or because the nature of the data does not lend itself well to such automated data collection. Various efforts have been made in the past to collect such data, such as by observing the data manually, and then recording it, such as by writing it into a log on a sheet of paper. Unfortunately, such methods tend to be unreliable, inconsistent, time consuming, difficult to expand across an entire fabrication facility, and difficult to monitor. Further, entry of such information into a statistical process control system tends to have the same problems.
[0006] What is needed, therefore, is a system by which data can be more reliably gathered and entered into a data processing system.
SUMMARY
[0007] The above and other needs are met by a data collection system according to the present invention. A data input form receives data, and a message queue receives the data from the data input form, and temporarily manages the data until the data collection system can process the data. A temporary data storage temporarily stores the data received by the message queue while waiting for the data collection system to process the data. A transaction manager receives the data from the message queue and processes the data. A data logger logs the processing transactions of the transaction manager. A data loader receives the data from the transaction manager and prepares the data for storage. A data storage device receives the data from the data loader.
[0008] In this manner, the data collection system according to the present invention provides means for collecting the data that would otherwise be lost during integrated circuit processing, because there is no automated way for it to be collected and stored. Further, the data collection system makes the data available in a form where it can be accessed by a statistical process control engine, thereby extending the benefits of statistical process control to data, and thereby to processes, which had previously not been accessible to such. Thus, the data collection system provides for an increased level of processing control.
[0009] In various embodiments, the input form resides on a presentation layer of the data collection system, the message queue, temporary data storage, transaction manager, data logger, and data loader all reside on a business logic layer of the data collection system, and the data storage device resides on a data service layer of the data collection system. The system preferably includes an output form for presenting statistically manipulated historical trends of the data. A statistical process control engine preferably receives the data from at least one of the transaction manager and the data storage device, and statistically manipulates the data. In one embodiment a state simulation engine gathers and provides state data between the data collection system and a statistical process control engine. The data input form is preferably implemented as a web object that is readable with a web browser. A web server preferably serves the data input form.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Further advantages of the invention are apparent by reference to the detailed description when considered in conjunction with the figures, which are not to scale so as to more clearly show the details, wherein like reference numbers indicate like elements throughout the several views, and wherein:
[0011] FIG. 1 is a functional block diagram of a data collection system according to a preferred embodiment of the present invention.
[0012] FIG. 2 is a functional interaction flow chart depicting a method of using a data collection system according to a preferred embodiment of the present invention.
[0013] FIG. 3 is a functional block diagram of a computerized system, such as a data collection system, employing a state simulation engine according to a preferred embodiment of the present invention.
DETAILED DESCRIPTION
[0014] With reference now to FIG. 1 , there is depicted a functional block diagram of a data collection system 10 according to a preferred embodiment of the present invention. As depicted in FIG. 1 , the data collection system 10 is functionally divided into three different functional groups or layers, which are the presentation layer 20 , the business logic layer 30 , and the data service layer 40 . The architecture of the data collection system 10 as given in FIG. 1 is structured using layers. However, it is appreciated that there are other software architecture structures as well, and that the data collection system 10 according to a preferred embodiment of the present invention is not limited to a layered architecture.
[0015] The presentation layer 10 of the data collection system 10 preferably handles data input and data output that is received from and presented to a user. Thus, the data collection system 10 preferably includes a data input screen 22 , by which an operator can input various requested pieces of data. The data collection system 10 provides its output, such as control charts and so forth, using an output screen 24 . Preferably, there are also screens 23 by which user and other rights are administered. Most preferably, the input screen 22 is presented at a location that is proximate the processing equipment or other source of the information that the operator is to enter into the data collection system 10 via the input screen 22 . For example, the input screen 22 is preferably presented on a terminal or other display, such as that of a networked personal computer, residing adjacent an etch chamber, or any other data source.
[0016] The information entered in the input screen 22 of the presentational layer 20 is preferably written to a message queue 34 which resides within the business logic layer 30 of the data collection system 10 . In addition, some information, commonly referred to as metadata, or data in regard to the data, which is received through the input screen 22 is also delivered to a user information module 46 that resides within the data service layer 40 . The user information module 46 preferably enables a variety of housekeeping functions, such as ensuring that the operator has clearance to use the data input screen 22 . Most preferably, all of the forms 22 - 24 are implemented as web objects, as described in more detail hereafter.
[0017] The information received by the message queue 34 is preferably written to a temporary data repository 32 , where it can be read at a point in time when the transaction manager 36 is available to process the data that has been input. Thus, the transaction manager 36 preferably requests and reads the input data from the message queue 34 , which fetches it as requested from the temporary data repository 32 . Most preferably, a logger 38 receives information from the transaction manager 36 , which provides a historical record of the functions performed by the transaction manager 36 .
[0018] The input data itself is forwarded to a data loader module 39 , which determines the proper data repository for the input data, which data repositories are preferably implemented on the data service layer 40 , as depicted in FIG. 1 . The data loader module 39 preferably submits the input data to a raw data repository 42 , where it is available to other data processing systems. Most preferably, the raw data repository 42 is external to the other elements of the data collection system 10 , and is available over a network, such as network attached storage, or on a server. Most preferably, the hardware platforms for the data collection system 10 are highly distributed, and may reside at several locations within a network.
[0019] The data loader module 39 preferably associates the input data as stored on the raw data repository 42 with information that it reads from a tool properties files 44 , which contains information in regard to the tool from which the input data was taken, or which is associated with the input data. The transaction manager receives or accesses a message from the message queue and verifies the message for content and completeness. The transaction is preferably sent to the data loader, where the transaction is converted to the appropriate structure for loading to the target data system. The data loader preferably retrieves and updates the tool properties files where critical information for tool and tool conditions are stored. The feed back from the data loader to the transaction manager is preferably used to log the event results and, if needed, the message is preferably re-queued in the message queue, if the transaction was not completed do to resource availability. For other transaction failures, the message can be achieved for later evaluation and the logged performed. Thus, the data collection system 10 provides for a systemized method of collecting data that would otherwise be lost during processing because there is no provision for the automatic collection of the information.
[0020] For example, information in many engineering data collection systems is wafer-centric, or in other words is referenced via the identity of a processed wafer to which all data is associated. The implication for this is that if there is any information that is not associated with a given processed wafer, then it doesn't fit neatly into the traditional engineering data collection system, and tends to get overlooked. The present system overcomes these shortcoming of the prior art data collection systems, by allowing information to be gathered without reference to a processed wafer. However, the data collection system 10 according to the present invention could also reference information in regard to processed wafers, if so desired.
[0021] This collected data is preferably then used, such as described above, to variously improve the fabrication process, improve the material handling, control processes or other elements, and so forth. FIG. 2 provides a functional interaction flow chart depicting a method 100 of using the data collection system 10 and the data which it collects, according to a preferred embodiment of the present invention.
[0022] Preferably, an engineer 50 or other designer of the data collection process builds a web based data input form 22 , as given by transaction 102 . As a part of this process, the engineer preferably defines the parameters to be collected, identifies the parameter attributes of interest, and publishes the data collection form 22 for use by technicians 60 , such as within the fabrication facility.
[0023] As will be discussed in more detail below, the system is most preferably implemented with web interfaces, so that client computers can access the data collection system 10 via a simple web browser operating on any desired platform. However, the system 10 could be implemented on other platforms as well, and could be implemented on a proprietary platform if so desired. The engineer 50 determines what information should be gathered and entered into the data input form 22 , and creates as many such data input forms 22 as desired. Obviously, additionally engineers 50 or others can also create additional forms.
[0024] A technician or operator 60 enters the data into the data input form 22 , as given by transaction 104 . For example, the technician 60 may enter a temperature reading, or some other parameter that is requested by the engineer 50 via the data input form 22 . In order to do so, the technician 60 may need to take a measurement that is not automatically made otherwise. The information is input to the input form 22 , and submitted to the data collection system 10 with the other desired information, such as by pressing a button within the form to enter the data.
[0025] Once the information has been input, it is preferably either accessible to or automatically submitted to a statistical process control application 70 , as indicated by transaction 106 . The statistical process control application 70 is in one embodiment a dedicated statistical engine which is proprietary to the data collection system 10 , or is alternately a statistical engine that is selected as desired from a library of such by the engineer 50 . However, in the most preferred embodiment, the statistical process control application 70 is the main statistical engine for the facility in which the data collection system 10 is implemented.
[0026] Thus, it is most preferred that the data be submitted automatically to the statistical engine 70 , so that it can produce output forms 24 from the data, such as statistical process control charts, and other such reporting mechanisms, as given in transaction 112 . Thus, the input data is preferably routed to the appropriate output forms 24 . If the data indicates that there is some type of problem, such as if a predefined limit or trend is violated, then the system 10 preferably provides an appropriate alert.
[0027] The control charts 24 are preferably available immediately for real time analysis by the technician 60 , as given in transaction 108 , so that action can be taken if something is wrong. In addition, the control charts 24 are also preferably available for an offline analysis, such as by the engineer 50 as given in transaction 110 . As mentioned above, such output is preferably provided via a web interface so that it can be accessed in a platform independent manner. However, in other embodiments, the manipulated data output may be provided in a more proprietary or platform dependent manner.
[0028] It has typically been somewhat difficult to integrate a software program such as the data collection system 10 described above with another system such as an existing statistical process control system. In addition, it is likewise difficult to integrate a system like the data collection system 10 into a web based interface, even though there are tremendous benefits to doing so. The problems generally center around the inability of one or both of the programs to be aware of the other, in that they were not originally designed to interoperate.
[0029] For two or more programs to interoperate as a unified application, each program is preferably made aware of the operating state of all other programs in the application, according to a preferred embodiment of the present invention. Thus, there are three levels of so called state information that are preferably provided to all programs within an application, which are the individual program states, the application state, and the business transaction state. State information preferably includes a designation of a program's parameters, the value of those parameters, and the operating state of the program. The state information is preferably stored throughout the running life of the application, and thus can be called on at any time. When a program is able to access such state data, then it is able to coexist with other programs within a unified application.
[0030] This goal is preferably accomplished with the use of a state simulation engine 200 , which most preferably operates in conjunction with the data collection system 10 and the statistical process control engine 70 , as depicted in FIG. 3 . The state simulation engine 200 preferably can either permit or restrict the sharing of information between different program which make up a given application. For example, one program could be the data collection system 10 and another program could be the statistical process control engine 70 .
[0031] Communication between the various programs of the application is preferably accomplished through application programming interfaces, which are built into the individual programs, and which the state simulation engine 200 can be programmed to receive data from and provide data to as represented by lines 204 in FIG. 3 . Thus, the state simulation engine 200 provides indirect paths for every program in the application to be made aware of what it needs to know about the other programs, which paths are indicated by virtual connections 202 in FIG. 3 .
[0032] Thus, the preferred embodiments of the present invention enable the collection and use of data that would typically be lost during the integrated circuit fabrication process. Therefore, the present invention allows for greater control, tracking, and prediction of the processes so used. Further, the present invention provides a way for a data collection system to be integrated with a statistical process control engine, and for the entire application to be accessed through web applications.
[0033] The foregoing description of preferred embodiments for this invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments are chosen and described in an effort to provide the best illustrations of the principles of the invention and its practical application, and to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.
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A data collection system. A data input form receives data, and a message queue receives the data from the data input form, and temporarily manages the data until the data collection system can process the data. A temporary data storage temporarily stores the data received by the message queue while waiting for the data collection system to process the data. A transaction manager receives the data from the message queue and processes the data. A data logger logs the processing transactions of the transaction manager. A data loader receives the data from the transaction manager and prepares the data for storage. A data storage device receives the data from the data loader.
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FIELD OF THE INVENTION
The invention concerns a method and a device for attenuating movement in self-propelled, unsprung construction machines, particularly wheeled loaders, with an implement driven by a hydraulic cylinder.
BACKGROUND OF THE INVENTION
Many generic types of self-propelled construction machines have no damping or spring system. This is firstly because springing is disadvantageous to loading procedures due to its yield under lifting and frictional forces, and secondly because provision of a spring system involves high structural outlay which entails not inconsiderable investment and maintenance costs. However, the good driving response, e.g. agility and handling, of such unsprung construction machines are accompanied by a lack of driving comfort, particularly in the working, transport and transfer cycles.
Nevertheless, the time factor is crucial to the cost-effectiveness of such construction machines. Self-propelled construction machines are frequently moved between different building sites at short notice, with the time required for transferring them—i.e. the transfer cycle—playing a decisive role.
However, in unsprung construction machines, an increase in road speed to reduce transfer times is closely linked with the requirements for driving comfort and safety and the permissible stresses for the operator from the point of view of health and safety. If a certain road speed is exceeded, high unwanted pulses and vibrations are recorded which are transmitted to the cab.
In recent years an attempt has therefore been made to find a compromise between the driving behavior and driving comfort of self-propelled, unsprung construction machines, using passive vibration attenuation systems, for example in wheeled loaders. In contrast, active vibration attenuation systems are of no practical significance to structural implementation, due to their complexity and the associated problems.
A hydraulic system in the form of a passive vibration attenuation system for mobile machines fitted with implements is known from DE 42 21 943 C2. In this case it is anticipated that a hydraulic accumulator be used as a load springing system, the hydraulic pipes responsible for raising and lowering the implement being connected between the hoist cylinder and a control valve. It is disclosed that at least one nozzle is provided in conjunction with several directional valves between the load springing system for variable adjustment of the load pressure of the hydraulic accumulator to the respective load pressure of the hoist cylinder, the valves in pilot pipes being operated by manometric switches provided between a pilot sensor and the control valve. In principle, this passive vibration attenuation system uses the yield of the hydraulic accumulator to permit an antiphase movement of the configuration, which itself attenuates the movement of a shovel in relation to the construction machine.
The disadvantage of this solution is that not only the hydraulic accumulator, but also additional directional valves, manometric switches, and nozzles must be provided in the construction machine, automatically entailing higher costs.
So-called suspension systems, which are predominantly used in agricultural tractors, are also known from the state of the art.
This involves combinations of springs and hydraulic dampers in parallel circuits. The damping characteristic is fixed in passive systems (fixed nozzles) and electronically-modifiable in active systems.
The fundamental difference between the passive vibration attenuation system described above and a suspension system lies in the mechanical structure of the moving masses, whereby the suspension system is itself a spring-damper element located between the mass of the vehicle and the individual masses of the wheels and axles, to remove unwanted vibratory movements by dissipation. An invention for the attenuation of movement in construction machines which works on the basis of an electro-hydraulic system for controlling the hoist cylinder is also known from U.S. Pat. No. 5,897,287 A. The purpose of this invention is to ensure a constant pressure in the hoist cylinders. The pressure in the hoist cylinders is permanently monitored and kept constant by means of a pressure sensor, taking the position of the shovel into account, to prevent unwanted lowering of the shovel.
The hydrodynamic valves are a particular disadvantage of this solution. They are necessary for the requisite pressure regulation, but not for attenuating movement in wheel loaders. Experience has shown that excitation/pulses or pulse oscillation generated by the pitching of the loaded shovel can be well compensated in this way, but this solution is unsuitable for cab vibrations.
In conclusion, it must be stated that the passive movement or vibration attenuation system already known from the state of the art is not optimized—or only optimized with restrictions—for changing operating conditions, and that it is only designed for quite specific problems if attenuation of cab vibration is taken into account. Transferring the suspension systems used in agricultural engineering to unsprung construction machines is not possible, for reasons of a permanent connection between the front axle and the front frame. Very high costs also arise from an unjustifiable outlay for highly-dynamic pressure control valves with the use of the active vibration attenuation system already known from U.S. Pat. No. 5,897,287 A.
A device for attenuating movement in self-propelled, unsprung construction machines (e.g. excavators) is known from U.S. Pat. No. 5,832,730. The implement is driven by means of a hydraulic cylinder. The construction machine also has a hydraulic source, a controlled valve for supplying the hydraulic cylinder with hydraulic fluid and a control unit with control software. Two pressure sensors are provided on the boom cylinder, the measurement signals from which are processed as incoming signals by the control software and converted into an acceleration signal, from which a pilot current is determined for the valve as an output variable for a compensating movement by the hydraulic cylinder. This device becomes effective when the implement is operated by the driver, i.e. the driver's control signals are overridden to attenuate movement automatically if unwanted movements occur. This specification does not disclose attenuation of movement during travel, independently of operation of the implement by the driver.
OBJECT OF THE INVENTION
The purpose of the invention is to develop a method and device for attenuating movement in construction vehicles which can be adapted to changing situations of the construction machine, e.g. cab damping or shovel damping, which is cost-effective and which can be retrofitted to hitherto unsprung construction vehicles with little outlay.
SUMMARY OF THE INVENTION
The purpose of the invention is to develop a method and device for attenuating movement in a construction machine which can be adapted to changing situations of the construction machine, e.g. cab damping or shovel damping, which is cost-effective and which can be retrofitted to hitherto unsprung construction machine with little outlay, whereby the damping is also to be optimized when the shovel is loaded. This problem is solved inventively by the characteristics of the method in accordance with patent claim 1 and by the characteristics of the device in accordance with patent claim 9 . The sub-claims referring back show further advantageous embodiments of the invention.
According to the inventive concept, the method for attenuating movement in a construction machine includes the stages in the method below and relevant components of the device
(a) Detection of the acceleration signal by the acceleration sensor while the construction machine is moving; (b) Processing of the acceleration signal as an input variable by the control software of the control unit and determination of a control current for the valve as a function of the damping mode selected as an output variable for attenuating movement, and: (c) Supplying the hydraulic cylinder with hydraulic fluid through the valve as a function of the control current.
In a preferred embodiment of the invention, the pressure signals detected by a pressure sensor in the hydraulic cylinder to determine the fill factor and/or the position of the lift frame detected by an angle sensor may also be communicated to the control unit as further input variables in addition to the input variable (A.). The pressure signals in the hydraulic cylinder indicate the fill factor or shovel load in order to determine load-dependent control parameters in an adaptive control algorithm. As the control algorithm is adaptive, i.e. self-adjusting, optimum damping in respect of the shovel load can be achieved for different operating points.
The fact that the construction machine can be operated in two different damping modes, namely cab mode and shovel mode, is particularly advantageous. Cab mode is preferably activated to obtain a higher road speed on transfer journeys. The changeover to shovel mode takes place when the shovel located on the hoist gear is damped, achieving better handling when the construction machine is working. For the sake of integrity, it should be mentioned that a combination of both damping modes is, of course, possible. The mode may be selected by the driver of the machine or, in a particularly advantageous way, automatically, by analyzing the signal from the pressure sensor in order to activate shovel mode when the shovel is full and cab mode when the shovel is empty.
Changeover between the individual damping modes by the operator is possible not only when stationary but also during movement, whereby a distinction can be made between an operating point of a pressure level and/or the road speed. Changeover between individual damping modes by the operator preferably takes place using the pressure sensor located in the hydraulic cylinder.
The principal significant characteristics and advantages of the invention over the state of the art are:
cost-effective implementation of an active damping system by the addition of an acceleration sensor and an algorithm implemented in the control unit, using the existing electro-hydraulic system of the construction machine; Increasing the achievable road speeds by stabilizing the construction machine; Increasing productivity and driving comfort by the facility of choosing between two damping modes, e.g. cab damping and/or shovel damping; Implementation of speed-dependent damping by means of the adaptively-configured control unit and determination of the fill factor of the shovel by means of an optional pressure sensor.
It is anticipated that the device for attenuating movement in self-propelled, unsprung construction machines, particularly wheeled loaders, will have a hydraulic source in the form of an implement driven by a hydraulic cylinder, a controlled valve for supplying hydraulic fluid to the hydraulic cylinder, at least one sensor for detecting a physical measured variable and a control unit with control software, an acceleration sensor being provided as a sensor and the control unit being configured to process the signals from the acceleration sensor as input signals by means of the control software and to determine a pilot current for the valve as an output variable for a compensatory movement of the hydraulic cylinder.
The inventive device differs from the state of the art in that speed control of the hydraulic cylinder on the basis of acceleration feedback is exercised instead of pressure regulation. No highly-dynamic valves are necessary, so the valve can be used in an advantageous way for the working circuit of the control block.
If the construction machine is fitted with an electro-hydraulic system, i.e. if the main control block for controlling the working functions is actuated by a controller using electrical signals, no further additional hydraulic components or special electronic components will be required to complete the task.
The acceleration forces acting directly upon the shovel and/or cab of the construction machine can be detected by the acceleration sensor, to initiate an antiphase movement of the hydraulic cylinder. The signal detected by the acceleration sensor is communicated to the control unit, where it may be weighted with a pressure signal and a distance-compensating signal and converted into a corresponding signal which determines the current destined for the valve controlling the hydraulic cylinder. A cross-section of the actuated valve is then opened, permitting a corresponding volumetric flow to the hydraulic cylinder.
The acceleration sensor may be located at any point on the construction machine, but preferably in the vicinity of the function or the sub-assembly of the machine to be damped, i.e. the shovel or driver's cab of the construction machine.
All external excitation of the construction machine entails the effect of unwanted force and thus movement on the structure of the machine. The inventive movement attenuation system generates a counterforce in the hydraulic cylinders of the working configuration, particularly advantageously in the hoist cylinders, by means of the hydraulic fluid, to compensate for the effect of force or movement. In a particularly advantageous embodiment of the invention, the pressure signal is detected by a pressure sensor, which is preferably located in the vicinity of the rear flange of the hydraulic hoist cylinder. This pressure signal represents the fill factor of the shovel of the configuration. As the fill factor may fluctuate constantly, provision is made for the control unit to be configured adaptively. In this way, optimum compensation for vibration adapted to the load may be achieved. The pressure sensor is consequently in a position to distinguish an empty shovel from a full one and to communicate the corresponding signal to the control unit.
The pressure sensor can be complemented by an angle sensor or by another position sensor (e.g. a hoist sensor for a hoist cylinder). The angle sensor detects the position of the lift frame and compares it with the reference value previously saved. A controller processes the deviation of the angle position from the reference position. An admissible range for the position of the lift frame can be specified in an advantageous way in the control unit, the content of which during the attenuation movement is one of the control or regulatory tasks of the control facility. The current position can be measured by an angle sensor located on the lift frame.
The control unit provided on the construction machine for controlling the working function is inventively complemented by control software, the algorithm of which can contain multiple damping functions. Whilst only the unwanted acceleration of the shovel could hitherto be compensated by state of the art movement attenuation systems, the appropriate damping functions can now be activated by selecting a desired damping mode. Typical damping functions for the shovel mode, cabin mode but also for the combined mode are provided in the software. An appropriate pilot current for the valve is released as a function of the damping mode selected, according to the relevant damping function.
BRIEF DESCRIPTION OF THE DRAWINGS
Further details, features and advantages of the invention emerge from the following description of a specimen embodiment, referring to the relevant drawings.
FIG. 1 is a diagrammatic representation of the external excitation/pulses affecting a construction machine;
FIG. 2 shows control system architecture of the device for attenuating movement, and:
FIG. 3 shows the signal structure of the device for attenuating movement.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a diagrammatic illustration of the external excitation/pulses 4 which typically affect a piece of construction machinery 1 . The cab 1 . 1 of the wheeled loader shown here undergoes vertical acceleration by carriageway excitation 4 . 1 and excitation 4 . 2 by movement of the configuration. On one hand, the excitation/pulses 4 or bounce generated by unevenness of the carriageway 3 during travel is transmitted to the cab 1 . 1 by the tires 1 . 3 and on the other hand the excitation/pulses 4 . 2 generated by pitching of the shovel 1 . 2 . 2 or pulse oscillations from the hydraulic cylinder 1 . 4 not shown are transmitted to the cab 1 . 1 . In the absence of a damping system, vehicle or cab damping is solely by the tires 1 . 3 of the construction machine 1 . Excitation/pulses from the carriageway 4 . 1 or configuration 4 . 2 may be superimposed on each other during the working or transfer cycle of the construction machine 1 , entailing increased and thus unwanted cab acceleration.
FIG. 2 shows the control system architecture of the device for attenuating movement in a construction machine 1 in a closed control circuit. This specimen embodiment illustrates activation of the hydraulic cylinder 1 . 4 when excited by the configuration 1 . 2 shown in FIG. 1 and by the carriageway 3 , using the inventive acceleration sensor 2 . 1 , the angle sensor 2 . 2 and the pressure sensor 2 . 3 .
The construction machine 1 shown in FIG. 1 has an ex works valve 1 . 5 of the control block not shown, a control unit 6 , the angle sensors 2 . 2 , the optional pressure sensor 2 . 3 and an acceleration sensor 2 . 1 .
Excitation 4 . 1 of the construction machine 1 by the carriageway 3 is transmitted through the wheels/tires 1 . 3 of the construction machine 1 just as the excitation 4 . 2 by the configuration 1 . 2 is transmitted to the cab 1 . 1 of the construction machine 1 . This mutually superimposed excitation 4 is detected by an acceleration sensor 2 . 1 and communicated to the control unit 6 as an electrical signal. This electrical signal forms the first input variable for the control unit 6 . The position 10 of the lift frame 1 . 2 . 1 is communicated to the control unit 6 as a further input variable. The position 10 of the lift frame 1 . 2 . 1 is monitored by the ex works angle sensors 2 . 2 on the construction machine 1 to avoid over-long hydraulic cylinder strokes and configuration position drift. In addition, the pressure 8 in the hydraulic cylinder 1 . 4 is also measured by a pressure sensor 2 . 3 in the specimen shown here. The fill factor of the shovel 1 . 2 . 2 . can be determined by this optionally-useable pressure sensor 2 . 3 . The goods with mass located in the shovel 1 . 2 . 2 exercises a compressive force on the hydraulic cylinder 1 . 4 , which is detected by the pressure sensor 2 . 3 . The input signals of the sensors 2 or measurement converter are processed to generate an output signal according to an algorithm shown in FIG. 3 . The output signal is an electrical signal and provides the current for a valve 1 . 5 of a control block not shown. A cross-section of the valve 1 . 5 is opened, whereby the current is proportional to the volumetric flow 7 released. The hydraulic cylinder 1 . 4 is moved by the admission and discharge of hydraulic fluid, the stroke speed then being proportional to the released volumetric flow 7 and the reciprocating movement of the hydraulic cylinder 1 . 4 corresponding to a movement compensating for carriageway excitation 4 . 1 and configuration excitation 4 . 2 . The pressure S then arising in the hydraulic cylinder 1 . 4 is again detected by the pressure sensor 2 . 3 and communicated to the control unit 6 . The external excitations 4 not attenuated by the control unit 6 of the construction machine 1 are detected as acceleration 5 by the acceleration sensor 2 . 1 and communicated to the control unit again. This closes the control circuit.
An antiphase movement of the hydraulic cylinder 1 . 4 can be generated by means of this control strategy using the components described above, in order to compensate for the external excitation 4 , e.g. the cab excitation 4 . 1 or configuration excitation 4 . 2 .
FIG. 3 shows the signal structure of the device for attenuating movement. The control unit 6 implements an algorithm for processing the input signals. The control unit 6 has three modules 12 , namely the active ride compensator 12 . 1 , the boom position compensator 12 . 2 and the load compensator 12 . 3 , each module 12 . 1 - 12 . 3 processing at least one input signal and generating a corresponding output signal.
The active ride compensator 12 . 1 processes the signal from the acceleration sensor 2 . 1 and determines the pilot current 9 for the valve 1 . 5 , to initiate a compensating reciprocating cylinder movement. The acceleration detected is amplified by an amplifying element and converted into a signal as a function of a selected damping mode 11 by means of an interpolation function. However, the interpolation function is only activated by a generated signal from the load compensator 12 . 3 described below.
Damping modes 11 , cab damping 11 . 1 and shovel damping 11 . 2 include different mathematical transfer functions, which can be initiated individually or with a combined effect. The signal generated for the pilot current 9 is amplified immediately before it leaves module 12 . 1 . The excess present in valve 1 . 5 is also compensated by an additional proportion 6 . 6 of the pilot current 9 .
The signal is communicated to the boom position coordinator 12 . 2 , which represents the position 10 of the lift frame 1 . 2 . 1 . This signal is detected by angle sensors 2 . 2 located on the lift frame 1 . 2 . 1 . When the damping function is initiated, the system saves the current position 10 of the lift frame 1 . 2 . 1 as a reference position. If the load introduced into the shovel 12 . 2 of the implement 1 . 2 changes, the pitch angle will change, whereby the position 10 of the lift frame 1 . 2 . 1 will change.
This angle position is detected by the angle sensor 2 . 2 and compared with the reference position in the boom position compensator 12 . 2 . The deviation of the angle position from the reference position is processed by a PID controller 6 . 1 and subsequently further processed by a transfer element 6 . 4 in the form of a limiter. The position controller is not activated until the position of the lift frame departs from an admissible range. The signal generated by the PID controller and restricted by the limiter is now added to the signal generated by the active ride compensator.
The load compensator processes the signal from the pressure sensor 2 . 3 , which is located in hydraulic cylinder 1 . 4 . The pressure in the hydraulic cylinder 1 . 4 indicates the fill factor of the shovel 1 . 2 . 2 or the compressive force applied to the hydraulic cylinder 1 . 4 by the goods with mass located in the shovel 1 . 2 . 2 . The signals from the pressure sensor 2 . 3 are covered by means of a transmission element, subsequently amplified by an amplifying element and then processed by a low-pass filter. The low-pass filter only filters out the steady-state proportion of the signal, which is in proportion to the shovel load or shovel filling. The signal generated is now communicated to the active ride compensator and initiates the aforementioned interpolation function, as a function of the intensity of the signal. The interpolation function includes determination of the controller parameters of the active ride compensator as a function of the shovel load.
It was possible to prove that cab acceleration 5 of construction machine 1 excited by carriageway and configuration 4 . 1 , 4 . 2 was considerably reduced in a specific frequency band by the device and method for attenuating movement compared to passive movement attenuation systems. Measurements demonstrated that the relative attenuation of movement still increased as the shovel load increased. In conclusion, it may be stated that the inventive movement attenuation system produces a sustained improvement in machine stability and ensures better tractability of construction machine 1 , particularly at high road speeds.
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The invention relates to a method and a device for damping the displacement of construction machines, in particular wheel loaders, comprising working equipment that is driven by means of a hydraulic cylinder, a hydraulic source, a controlled valve for supplying the hydraulic cylinder with hydraulic fluid, a regulator unit comprising control software, in addition to an acceleration sensor.
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[0001] This application claims the benefit of the Korea Patent Application No. P03-21117 filed on Apr. 3, 2003, which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a liquid crystal display using horizontal electric field, and more particularly to a liquid crystal display and a fabricating method thereof that are capable of reducing the number of mask processes.
[0004] 2. Description of the Related Art
[0005] Generally, liquid crystal displays (LCDs) control light transmittance of liquid crystal material using an electric field to thereby display a picture. The liquid crystal displays are classified into a vertical electric field type and a horizontal electric field type in accordance with a direction of the electric field driving the liquid crystal.
[0006] The liquid crystal display of vertical electric field type, in which a common electrode formed on an upper substrate and a pixel electrode formed on a lower substrate are arranged as facing each other, drives a liquid crystal of a twisted nematic mode (TN) by a vertical electric field formed between the common electrode and the pixel electrode. The liquid crystal display of vertical electric field type has an advantage of a large aperture ratio, while it has a defect of a narrow viewing angle about 90°.
[0007] The liquid crystal display of horizontal electric field type drives a liquid crystal of in plane switch (hereinafter referred to as “IPS”) mode by a horizontal electric field between the pixel electrode and the common electrode disposed in parallel on the lower substrate. The liquid crystal display of horizontal electric field type has an advantage of an wide viewing angle about 160°. Hereinafter, the liquid crystal display of horizontal electric field type will be described in detail.
[0008] The liquid crystal display of the horizontal electric field type comprises a thin film transistor array substrate (a lower substrate) and a color filter array substrate (an upper substrate) as faced and joined each other, a spacer for uniformly maintaining a cell gap between two substrates and a liquid crystal injected into a space provided by the spacer.
[0009] The thin film transistor array substrate includes a plurality of signal lines for forming a horizontal electric field on a basis of a pixel, a plurality of thin film transistors, and an alignment film applied for a liquid crystal alignment thereon. The color filter array substrate includes a color filter for representing a color, a black matrix for preventing a light leakage and an alignment film applied for a liquid crystal alignment thereon.
[0010] In such a liquid crystal display, since the thin film transistor array substrate involves a semiconductor process and requires a plurality of mask processes, the manufacturing process is complicate to be a major rise factor in the manufacturing cost of the liquid crystal display panel. In order to solve this, the thin film transistor array substrate has been developed toward a reduction in the number of mask processes. This is because one mask process includes a lot of processes such as thin film deposition, cleaning, photolithography, etching, photo-resist stripping and inspection processes, etc. Recently, there has been highlighted a four-round mask process in which one mask process is reduced from the existent five-round mask process that is employed as a standard mask process.
[0011] [0011]FIG. 1 is a plan view illustrating a related art thin film transistor substrate of horizontal electric type using the four-round mask process, and FIG. 2 is a sectional view of the thin film transistor array substrate taken along the I-I′ and II-II′ line in FIG. 1.
[0012] Referring to FIGS. 1 and 2, the related art thin film transistor array substrate of horizontal electric type comprises a gate line 2 and a data line 4 formed on a lower substrate 45 in such a manner to intersect each other, a thin film transistor 6 formed at each intersection, a pixel electrode 14 and a common electrode 18 formed in order to apply the horizontal electric field in a pixel regions defined by the intersection and a common line 16 connected to the common electrode 18 . Moreover, the related art thin film transistor array substrate further comprises a storage capacitor 20 formed at an overlapped portion between the pixel electrode 14 and the common line 16 , a gate pad 24 connected to the gate line 2 , and a data pad 30 connected to the data line 4 and a common pad 36 connected to the common line 16 .
[0013] The gate line 2 supplies a gate signal to the gate electrode 8 of the thin film transistor 6 . The data line 4 supplies a pixel signal to the pixel electrode 14 via a drain electrode 12 of the thin film transistor 6 . The gate line 2 and the data line 4 are formed in an intersection structure to thereby define the pixel region 5 .
[0014] The common line 16 is formed in parallel with the gate line 2 with the pixel region 5 positioned between the common line 16 and the gate line 2 to supply a reference voltage for driving the liquid crystal to the common electrode 18 .
[0015] The thin film transistor 6 responds to the gate signal of the gate line 2 so that the pixel signal of the data line 4 is charged to the pixel electrode 14 . To this end, the thin film transistor 6 comprises a gate electrode 8 connected to the gate line 2 , a source electrode 10 connected to the data line 4 and a drain electrode 12 connected to the pixel electrode 14 . Further, the thin film transistor 6 includes an active layer 48 overlapping with the gate electrode 8 with a gate insulating film 46 positioned between the thin film transistor 6 and the gate electrode 8 and defining a channel between the source electrode 10 and the drain electrode 12 . The active layer 48 is formed to overlap with the data line 4 , a data pad lower electrode 32 and a storage electrode 22 . On the active layer 48 , an ohmic contact layer 50 for making an ohmic contact with the data line 4 , the source electrode 10 , the drain electrode 12 , the data pad lower electrode 32 and the storage electrode 22 is further formed.
[0016] The pixel electrode 14 , which is connected to the drain electrode 12 of the thin film transistor 6 via a first contact hole 13 passing through a passivation film 52 , is formed in the pixel region 5 . Particularly, the pixel electrode 14 comprises a first horizontal part 14 A connected to the drain electrode 12 and formed in parallel with adjacent gate line 2 and a second horizontal part 14 B formed to overlap with the common line 16 and a finger part 14 C formed in parallel with the common electrode 18 .
[0017] The common electrode 18 is connected to the common line 16 and is formed in the pixel region 5 . In addition, the common electrode 18 is formed in parallel with the finger part 14 C of the pixel electrode 14 in the pixel region 5 .
[0018] Accordingly, a horizontal electric field is formed between the pixel electrode 14 to which the pixel signal is supplied via the thin film transistor 6 and the common electrode 18 to which the reference voltage is supplied via the common line 16 . Moreover, the horizontal electric field is formed between the finger part 14 C of the pixel electrode 14 and the common electrode 18 . The liquid crystal molecules arranged in the horizontal direction between the thin film transistor array substrate and the color filter array substrate by the horizontal electric field becomes to rotate due to a dielectric anisotropy. The light transmittance transmitting the pixel region 5 differs in accordance with a rotation amount of the liquid crystal molecules and thereby the pictures can be represented.
[0019] The storage capacitor 20 consists of the common line 16 , a storage electrode 22 overlapping with the common line 16 with the gate insulating film 46 , the active layer 48 and the ohmic contact layer 50 positioned therebetween, and a pixel electrode 14 connected via a second contact hole 21 passing through the storage electrode 22 and the passivation film 52 . The storage capacitor 20 allows a pixel signal charged in the pixel electrode 14 to be maintained stably until the next pixel signal is charged.
[0020] The gate line 2 is connected, via the gate pad 24 , to a gate driver (not shown). The gate pad 24 consists of a gate pad lower electrode 26 extended from the gate line 2 , and a gate pad upper electrode 28 connected, via a third contact hole 27 passing through the gate insulating film 46 and the passivation film 52 , to the gate pad lower electrode 26 .
[0021] The data line 4 is connected, via the data pad 30 , to the data driver (not shown). The data pad 30 consists of a data pad lower electrode 32 extended from the data line 4 , and a data pad upper electrode 34 connected, via a fourth contact hole 33 passing through the passivation film 52 , to the data pad lower electrode 32 .
[0022] The common line 16 supplied with the reference voltage from the reference voltage source of exterior (not shown) via the common pad 36 . The common pad 36 consists of a common pad lower electrode 38 extended from the common line 16 , and a common pad upper electrode 40 connected, via a fifth contact hole 39 passing through the gate insulating film 46 and the passivation film 52 , to the common pad lower electrode 38 .
[0023] A method of fabricating the thin film transistor substrate having the above-mentioned structure using the four-round mask process will be described in detail with reference to FIGS. 3A to 3 D.
[0024] Referring to FIG. 3A, a first conductive pattern group including the gate line 2 , the gate electrode 8 and the gate pad lower electrode 26 is formed on the lower substrate 45 using the first mask process.
[0025] More specifically, a first metal layer 42 and a second metal layer 44 are sequentially formed on the upper substrate 45 by a deposition technique such as a sputtering to form a gate metal layer of double-structure. Then, the gate metal layer is patterned by the photolithography and the etching process using a first mask to thereby form the first conductive pattern group including the gate line 2 , the gate electrode 8 , the gate pad lower electrode 26 , the common line 16 , common electrode 18 and the common pad lower electrode 38 . Herein, the first metal layer 42 is formed with an aluminum system metal and the second metal layer 44 is formed with a chrome (Cr) or a molybdenum (Mo).
[0026] Referring to FIG. 3B, the gate insulating film 46 is formed on the lower substrate 45 provided with the first conductive pattern group. Further, a semiconductor pattern group including the active layer 48 and the ohmic contact layer 50 and a second conductive pattern group including the data line 4 , the source electrode 10 , the drain electrode 12 , the data pad lower electrode 32 and the storage electrode 22 are formed on the gate insulating film 46 using the second mask process.
[0027] More specifically, the gate insulating film 46 , a first semiconductor layer, a second semiconductor layer and a data metal layer are sequentially formed on the lower substrate 45 provided with the first conductive pattern group by deposition techniques such as the plasma enhanced chemical vapor deposition (PECVD) and the sputtering, etc. Herein, the gate insulating film 46 is made of an inorganic insulating material such as silicon oxide (SiO x ) or silicon nitride (SiN x ). The first semiconductor layer is made of amorphous silicon that an impurity is not doped and the second conductor layer is made of amorphous silicon that an impurity of a N type or P type is doped. The data metal layer is made of a molybdenum (Mo), a titanium (Ti), tantalum (Ta) or a molybdenum alloy, etc.
[0028] Then, a photo-resist pattern is formed on the data metal layer by the photolithography using a second mask. In this case, a diffractive exposure mask having a diffractive exposing part at a channel portion of the thin film transistor is used as a second mask, thereby allowing a photo-resist pattern of the channel portion to have a lower height than other photo-resist patterns of region portions.
[0029] Subsequently, the data metal layer is patterned by a wet etching process using the other photo-resist patterns to thereby provide the data pattern including the data line 4 , the source electrode 10 , the drain electrode 12 being integral to the source electrode 10 and the storage electrode 22 .
[0030] Next, the first semiconductor layer and the second semiconductor layer are patterned at the same time by a dry etching process using the same photo-resist pattern to thereby provide the ohmic contact layer 50 and the active layer 48 .
[0031] The photo-resist pattern having a relatively low height is removed from the channel portion by the ashing process and thereafter the source electrode, the drain electrode and the ohmic contact layer 50 of the channel portion are etched by the dry etching process. Thus, the active layer 48 of the channel portion is exposed to separate the source electrode 10 from the drain electrode 12 .
[0032] Thereafter, a remainder of the photo-resist pattern on the second conductive pattern group is removed using the stripping process.
[0033] Referring to FIG. 3C, the passivation film 52 including first to fifth contact holes 13 , 21 , 27 , 33 and 39 are formed on the gate insulating film 46 provided with the second conductive pattern group using the third mask process.
[0034] More specifically, the passivation film 52 is entirely formed on the gate insulating film 46 provided with the data pattern by a deposition technique such as the plasma enhanced chemical vapor deposition (PECVD). The passivation film 52 is patterned by the photolithography and the etching process using the third mask to thereby form first to fifth contact holes 13 , 21 , 27 , 33 and 39 . The first contact hole 13 is formed in such a manner to pass through the passivation film 52 and exposes the drain electrode 12 , whereas the second contact hole 21 is formed in such a manner to pass through the passivation film 52 and exposes the storage electrode 22 . The third contact hole 27 is formed in such a manner to pass through the passivation film 52 and the gate insulating film 46 and exposes the gate pad lower electrode 26 , whereas the fourth contact hole 33 is formed in such a manner to pass through the passsivation film 52 and exposes the data pad lower electrode 32 , and the fifth contact hole 39 is formed in such a manner to pass through the passivation film 52 and the gate insulating film 46 and exposes the common pad lower electrode 38 . Herein, when a metal which has high ratio of dry etching like a molybdenum (Mo) is used for the data metal, the first contact hole 13 , the second contact hole 21 and the forth contact hole 33 are formed in such a manner to pass through to the drain electrode 12 , the storage electrode 22 and the data pad lower electrode 32 , respectively, to thereby expose their side.
[0035] The passivaion film 52 is made of an inorganic insulating material such as the gate insulating film 46 or an organic insulating material having a small dielectric constant such as an acrylic organic compound, BCB (benzocyclobutene) or PFCB (perfluorocyclobutane), etc.
[0036] Referring to FIG. 3D, a third conductive pattern group including the pixel electrode 14 , the gate pad upper electrode 28 , the data pad upper electrode 34 and the common pad upper electrode 40 is formed on the passivation film 52 using the fourth mask process.
[0037] More specifically, a transparent conductive film is coated onto the passivation film 52 by a deposition technique such as the sputtering, etc. Then, the transparent conductive film is patterned by the photolithography and the etching process using a fourth mask, to thereby provide the third conductive pattern group including the pixel electrode 14 , the gate pad upper electrode 28 , the data pad upper electrode 34 and the common pad upper electrode 40 . The pixel electrode 14 is electrically connected, via the first contact hole 13 , to the drain electrode 12 while being electrically connected, via the second contact hole 21 , to the storage electrode 22 . The gate pad upper electrode 28 is electrically connected, via the third contact hole 37 , to the gate pad lower electrode 26 . The data pad upper electrode 34 is electrically connected, via the fourth contact hole 33 , to the data pad lower electrode 32 . The common pad upper electrode 40 is electrically connected, via the fifth contact hole 39 , to the common pad lower electrode 38 .
[0038] In this connection, the transparent conductive film may be made of an indium-tin-oxide (ITO), a tin-oxide (TO), an indium-zinc-oxide (IZO) or an indium tin zinc oxide (ITZO).
[0039] As described above, the related art thin film transistor array substrate of horizontal electric field type and the manufacturing method thereof adopts a four-round mask process, thereby reducing the number of manufacturing processes in comparison to the five-round mask process and hence reducing a manufacturing cost to that extent. However, since the four-round mask process also still has a complex manufacturing process and a limit in reducing a cost, there has been required an approach that is capable of more simplifying the manufacturing process and more reducing the manufacturing cost.
SUMMARY OF THE INVENTION
[0040] Accordingly, it is an object of the present invention to provide a liquid crystal display using horizontal electric field and a method of fabricating a liquid crystal display device that are capable of reducing the number of mask processes.
[0041] In order to achieve these and other objects of the invention, the liquid crystal display of horizontal electric field applying type according to the present invention comprises: a thin film transistor array substrate, wherein the thin film transistor array substrate includes an effective display area having a gate line, a common line parallel to the gate line, a data line intersected and isolated with the gate line and the common line with a gate insulating film therebetween to define a pixel area, a thin film transistor formed on each intersection of the gate line and the data line, a passivasion film for protecting the thin film transistor, a common electrode formed in the pixel area and connected to the common line and a pixel electrode connected to the thin film transistor and formed to produce horizontal electric field along with the common electrode in the pixel area, and a pad area having a gate pad formed with at least one conductive layer included in the gate line, a data pad formed with at least one conductive layer included in the data line, a common pad formed with at least one conductive layer included in the common line, which are formed on a lower substrate to form the thin film transistor array substrate; a color filter array substrate combined with the thin film transistor array substrate as facing each other; a driving integrated circuit mounted on the substrate in order to directly connect to any one of the gate pad and the data pad; and a package mold material for capsulating the pads and the driving integrated circuit.
[0042] The passivation film is formed on the effective display area except for the pad region.
[0043] The gate insulating film is formed on the gate pad, a lower portion of the data pad, the common pad and the effective display area.
[0044] The driving integrated circuit includes a gate driving integrated circuit connected to the gate pad.
[0045] The driving integrated circuit further includes a data driving integrated circuit connected to the data pad.
[0046] The liquid crystal display of horizontal electric field applying type further comprises a plurality of signal supplying lines for supplying a driving signal to the driving integrated circuit.
[0047] The liquid crystal display of horizontal electric field applying type further comprises a connector to which a conductive film for supplying a driving signal to the signal supplying line is attached.
[0048] The liquid crystal display of horizontal electric field applying type further comprises a second package mold material for capsulating a boundary portion of the connector and the conductive film and a boundary portion of the lower substrate and the conductive film.
[0049] Each of the gate line and the common line includes a main conductive layer and a subsidiary conductive layer for providing against an opening of the main conductive layer.
[0050] Each of the gate pad and the common pad includes the main conductive layer and the subsidiary conductive layer, and wherein the subsidiary conductive layer has an exposed structure.
[0051] Each of the gate pad and the common pad includes the subsidiary conductive layer.
[0052] The main conductive layer includes at least one of an aluminum system metal, a copper, a molybdenum, a chrome and a tungsten which are a low resistance metal; and wherein the subsidiary conductive layer includes a titanium.
[0053] The data line includes a main conductive layer and a subsidiary conductive layer for providing against the opening of the main conductive layer.
[0054] The data pad includes the main conductive layer and the subsidiary conductive layer, and wherein the subsidiary conductive layer has an exposed structure.
[0055] The data pad includes the subsidiary conductive layer.
[0056] The main conductive layer includes at least one of an aluminum system metal, a copper, a molybdenum, a chrome and a tungsten which are a low resistance metal; and wherein the subsidiary conductive layer includes a titanium.
[0057] The thin film transistor comprises: a gate electrode connected to the gate line; a source electrode connected to the data line; a drain electrode facing with the source electrode; and a semiconductor layer overlapped with the gate electrode with the gate insulating film therebetween to form a channel portion between the source electrode and the drain electrode.
[0058] The drain electrode and the pixel electrode are made of an identical conductive layer.
[0059] The semiconductor layer is formed on the gate insulating film along the data line, the source electrode, the drain electrode and the pixel electrode.
[0060] In order to achieve these and other objects of the invention, a method for fabricating a liquid crystal display of horizontal electric field applying type includes: preparing a thin film transistor array substrate having an effective display area and a pad area formed on a lower substrate, wherein the effective display area includes a gate line, a common line parallel to the gate line, a data line intersected with the gate line and the common line with a gate insulating film therebetween to define a pixel area, a thin film transistor formed on each intersection of the gate line and the data line, a passivasion for protecting the thin film transistor, a common electrode formed in the pixel area and connected to the common line and a pixel electrode connected to the thin film transistor and formed to produce horizontal electric field along with the common electrode in the pixel area, and the pad area includes a gate pad formed with at least one conductive layer included in the gate line, a data pad formed with at least one conductive layer included in the data line, a common pad formed with at least one conductive layer included in the common line; preparing a color filter array substrate combined with the thin film transistor array substrate as facing each other; combining the thin film transistor array substrate and the color filter array substrate to expose the pad region; exposing the common pad, the gate pad and the data pad; mounting a driving integrated circuit on the substrate in order to directly connect to any one of the gate pad and the data pad; and capsulating a pad connected with the driving integrated circuit with a package mold material.
[0061] The step of mounting the driving integrated circuit includes connecting the gate pad and the gate driving integrated circuit.
[0062] The step of mounting the driving integrated circuit further includes connecting the data pad and data driving integrated circuit.
[0063] The method according to claim 20 , further comprising the step of forming a plurality of signal supplying lines for supplying a driving signal to the driving integrated circuit.
[0064] The method for fabricating a liquid crystal display of horizontal electric field applying type further comprises the step of attaching a connector connected to the signal supplying lines with a conductive film for supplying a driving signal to the signal supplying lines.
[0065] The method for fabricating a liquid crystal display of horizontal electric field applying type further comprises the step of capsulating a boundary portion of the connector and the conductive film and a boundary portion of the lower substrate and the conductive film a second package mold material.
[0066] The step of preparing a thin film transistor array substrate includes: forming, on the lower substrate, a first conductive pattern group including the gate line, a gate electrode connected to the gate line, the common line parallel to the gate line, the common electrode, the gate pad and the common pad; forming a gate insulating film on the substrate having the first conductive pattern group thereon; forming a semiconductor layer at a predetermined area on the gate insulating film and a second conductive pattern group having the date line, a source electrode of the thin film transistor connected with the data line, a drain electrode of the thin film transistor being opposite to the source electrode, a pixel electrode connected with the drain electrode and paralleled to the common electrode and the data pad; and forming a passivation film for covering the second conductive pattern group.
[0067] The step of exposing the gate pad and the data pad includes etching the gate insulating film and the passivaion film using the color filter array substrate as the mask.
[0068] At least one of the first and the second conductive pattern group is formed to have a double-layer structure having a main conductive layer and a subsidiary conductive layer for providing against the opening of the main conductive layer.
[0069] The step of exposing the gate pad and the data pad includes exposing the subsidiary conductive layers of the gate pad and the common pad and the subsidiary conductive layer of the data pad.
[0070] The main conductive layer includes at least one of an aluminum system metal, a copper, a molybdenum, a chrome and a tungsten which are a low resistance metal, and wherein the subsidiary conductive layer includes a titanium.
BRIEF DESCRIPTION OF THE DRAWINGS
[0071] These and other objects of the invention will be apparent from the following detailed description of the embodiments of the present invention with reference to the accompanying drawings, in which:
[0072] [0072]FIG. 1 is a plan view showing the related art thin film transistor array substrate of liquid crystal display of horizontal electric applying type;
[0073] [0073]FIG. 2 is a sectional view of the thin film transistor array substrate taken along the lines I-I′ and II-II′ in FIG. 1;
[0074] [0074]FIGS. 3A to 3 D are sectional sequentially views illustrating a method of manufacturing the thin film transistor array substrate shown in FIG. 2;
[0075] [0075]FIG. 4 is a plan view showing a liquid crystal display of horizontal electric field applying type according to an embodiment of the present invention;
[0076] [0076]FIG. 5 is a plan view showing the liquid crystal display panel shown in FIG. 4;
[0077] [0077]FIG. 6 is a sectional view of the liquid crystal display panel taken along the lines III′-III′ and IV-IV′ in FIG. 4;
[0078] [0078]FIG. 7A and FIG. 7B are a plan view and a sectional view for explaining a first mask process among a manufacturing method of a thin film transistor array substrate according to the embodiment of the present invention, respectively;
[0079] [0079]FIGS. 8A to 8 C are sectional views for concretely explaining the first mask process among the manufacturing method of the thin film transistor array substrate according to the embodiment of the present invention;
[0080] [0080]FIGS. 9A and 9B are a plan view and a sectional view for explaining a second mask process among the manufacturing method of a thin film transistor array substrate according to the embodiment of the present invention, respectively;
[0081] [0081]FIGS. 10A to 10 F are sectional views for concretely explaining the second mask process among the manufacturing method of the thin film transistor array substrate according to the embodiment of the present invention;
[0082] [0082]FIGS. 11A and 11B are a plan view and a sectional view for explaining a pad opening process according to the embodiment of the present invention, respectively;
[0083] [0083]FIGS. 12A to 12 B are sectional views for concretely explaining the pad opening process according to the embodiment of the present invention;
[0084] [0084]FIG. 13 is a sectional view showing pads of a first structure in the thin film transistor substrate according to the embodiment of the present invention;
[0085] [0085]FIG. 14 is a sectional view showing pads of a second structure in the thin film transistor substrate according to the embodiment of the present invention;
[0086] [0086]FIGS. 15A and 15B are a plan view and a sectional view for representing the drive IC mounted to the pads shown in FIGS. 13 and 14, respectively;
[0087] [0087]FIGS. 16A and 16B are a plan view and a sectional view for representing a first package mold material formed at pad region on the thin film transistor array substrate;
[0088] [0088]FIGS. 17A and 17B are a plan view and a sectional view for representing a flexible printed circuit supplying a driving signal to the drive IC formed at pad region of the thin film transistor array substrate according to the embodiment of the present invention in detail; and
[0089] [0089]FIGS. 18A and 18B are a plan view and a sectional view for representing a second package mold material formed at pad region on the thin film transistor array substrate.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0090] Hereinafter, the preferred embodiments of the present invention will be described in detail with reference to FIGS. 4 to 18 B.
[0091] [0091]FIG. 4 is a plan view representing a liquid crystal display of horizontal electric field applying type according to the present invention.
[0092] Referring to FIG. 4, a liquid crystal display of horizontal electric field applying type according to the present invention comprises a gate drive integrated circuit (IC) 350 and a data drive IC 354 formed on a liquid crystal panel, and a flexible printed circuit (FPC) 354 supplying a driving signal to drive ICs 350 and 356 .
[0093] The data drive ICs 356 are mounted by a chip on glass (COG) system on the lower substrate 145 and are connected to data lines 104 via the data pad. Therefore, the data drive ICs 356 supply data signals to the data lines 104 .
[0094] For the sake of it, data control signals and data signals from a timing controller and a power source portion (not shown) on a PCB (Printed Circuit Board) 352 are supplied to a signal supplying line 208 via the FPC 354 and a COG connector 358 . A signal supplying line 208 is connected to an input terminal of each of the data drive ICs 356 through an input bump to thereby supply the data control signals and the data signals to the data drive IC 356 . The data drive IC 356 generates data driving signals using the data control signals and the data signals. The data driving signals are supplied to the data pad 130 through an output bump 286 connected to output terminals 284 of the data drive IC 356 .
[0095] The gate drive ICs 350 are mounted by a COG system on the lower substrate 145 and are connected to gate lines 102 via the gate pad 124 . The gate drive ICs 350 supplies a gate signal to the gate line 102 .
[0096] To this end, gate control signals and power source signals from a timing controller and a power source (not shown) on PCB (Printed Circuit Board) 352 are supplied to the signal supplying line 208 via the FPC 354 and the COG connector 358 . The signal supplying line 208 is connected to an input terminal of each of the gate drive ICs 350 through an input bump to thereby supply the gate control signals and the power source signals to the gate drive IC 350 . The gate drive IC 350 generates a gate-driving signal using the gate control signals and the power source signals. The gate driving signals are supplied to the gate pad 124 through an output bump 260 connected to output terminals 262 of the gate drive IC 350 .
[0097] The FPC 354 supplies control signals and power source signals from a timing controller and a power source (not shown) on the PCB 352 to the gate drive IC 350 and the data drive IC 356 corresponding thereto. That is, an input pad of the FPC 354 is connected to the PCB 352 and an output pad of the FPC 354 is connected to the COG connector 358 . Further, any one of output pads 282 of the FPC 354 is connected to the common pad 130 using the ACF 182 including the conductive ball 184 as shown in FIGS. 5 and 6.
[0098] On the hand, the signal supplying 208 , the pads, gate drive IC 350 and the data drive IC 356 connected on the lower substrate 145 are protected by a package mold material 252 as shown in FIG. 6. Further, the package mold material 252 is formed to capsulate a boundary portion of the FPC 354 and the COG connector 358 which are connected each other. The package mold material 252 is made of, for example, a sealing resin.
[0099] As shown in FIGS. 5 and 6, a liquid crystal panel 360 is fabricated by combining, using a sealant 204 , a thin film transistor array substrate in which a thin film transistor array is formed on the lower substrate 145 and a color filter array substrate in which a color filter array 202 is formed on an upper substrate 200 .
[0100] The thin film transistor array substrate comprises a gate line 102 and a data line 104 , which have a gate insulating film 146 therebetween, formed on a lower substrate 145 in such a manner to intersect each other, a thin film transistor 106 formed at each intersection of the gate line 102 and the data line 104 , a pixel electrode 114 and a common electrode 118 formed in order to apply the horizontal electric field in a pixel region defined by the interconnection and a common line 116 connected to the common electrode 118 . Moreover, the thin film transistor array substrate further comprises a storage capacitor 120 formed at an overlapped portion between a storage electrode 122 and the common line 116 , a gate pad 124 extended from the gate line 102 , and a data pad 130 extended form data line 104 and a common pad 136 extended from the common line 116 .
[0101] The gate line 102 for supplying a gate signal and the data line 104 for supplying a data signal are formed in an intersection structure to thereby define a pixel region 105 .
[0102] The common line 116 supplying a reference voltage used to drive the liquid crystal is formed in parallel with the gate line 102 with the pixel region 105 positioned between the common line 116 and the gate line 102 .
[0103] The thin film transistor 106 responds to the gate signal of the gate line 102 so that the pixel signal of the data line 104 is charged and maintained in the pixel electrode 114 . To this end, the thin film transistor 106 comprises a gate electrode 108 connected to the gate line 102 , a source electrode included in the data line 104 and a drain electrode 112 connected to the pixel electrode 114 . In addition, the thin film transistor 106 further includes an active layer 148 overlapping with the gate electrode 108 with a gate insulating film 146 positioned therebetween and defining a channel between the source electrode and the drain electrode 112 .
[0104] The active layer 148 is formed to overlap with the data line 104 , the data pad 130 and the storage electrode 122 . On the active layer 148 , an ohmic contact layer 150 for making an ohmic contact with the data line 104 , the drain electrode 112 , the data pad 130 and the storage electrode 122 is further provided.
[0105] The pixel electrode 114 being integral to the drain electrode 112 of the thin film transistor 106 and the storage electrode 122 is formed in the pixel region 105 . Particularly, the pixel electrode 114 comprises a horizontal part 114 A extended in parallel with adjacent gate line 102 from the drain electrode 112 and a finger part 114 B extended from the horizontal part 114 A in vertical direction.
[0106] The common electrode 118 is connected to the common line 116 and is formed in the pixel region 105 . Specially, the common electrode 118 is formed in parallel with the finger part 114 B of the pixel electrode 114 in the pixel region 105 .
[0107] Accordingly, a horizontal electric field is formed between the pixel electrode 114 to which the pixel signal is supplied via the thin film transistor 106 and the common electrode 118 to which the reference voltage is supplied via the common line 116 . In practically, the horizontal electric field is formed between the finger part 14 B of the pixel electrode 114 and the common electrode 118 . The liquid crystal molecules arranged in the horizontal direction between the thin film transistor array substrate and the color filter array substrate by the horizontal electric field becomes to rotate due to a dielectric anisotropy. Further, the light transmittance transmitting the pixel region 105 differs in accordance with a rotation amount of the liquid crystal molecules and thereby the pictures can be represented.
[0108] The storage capacitor 120 is comprised of the common line 116 and the storage electrode 122 overlapping with the common line 116 , wherein the storage electrode 122 has the gate insulating film 146 , the active layer 148 and the ohmic contact layer 150 between the storage capacitor 120 and the common line 116 , and being integral with the pixel electrode 114 . The storage capacitor 120 allows a pixel signal charged in the pixel electrode 114 to be maintained stably until the next pixel signal is charged.
[0109] The gate line 102 is connected, via the gate pad 124 , to a gate driver IC 350 mounted on the lower substrate. The gate pad 124 is extended from the gate line 102 to thereby form structure in which a titanium Ti included to the gate line 102 is exposed. The gate drive IC 350 and the gate pad 124 are packaged for the protection thereof by the package mold material 252 .
[0110] The common line 116 is connected to the FPC 354 for supplying the reference voltage from the power source of exterior (not shown) via the common pad 136 . The common pad 136 is extended from the common line 116 and has structure in which a titanium (Ti) included in the common line 116 is exposed.
[0111] More specifically, the gate line 102 , the gate electrode 108 , the common line 116 and common electrode 118 have a double-layer structure of metal layers of a first and a second metal layers 142 and 144 as stacked. Any one of the metal layers is made of any metal that has a relatively high strength and corrosion resistance such as a titanium (Ti) and a tungsten (W). Whereas, another metal layer is made of a low resistance metal such as an aluminum (Al) system metal, a molybdenum (Mo) and a copper (Cu) that are conventionally employed as a gate metal.
[0112] In this connection, in case where the first metal layer 142 is made of any metal that has a high strength and corrosion resistance, the gate pad 124 and the common pad 138 have structure in which the second metal layer 144 of an upper portion is removed and the first metal layer 142 of the lower portion is exposed. On the other hand, in case where the second metal layer 144 is made of any metal that has a high strength and corrosion resistance, the gate pad 124 and the common pad 138 have structure in which the second metal layer 144 of an upper portion is exposed.
[0113] The data line 104 is connected to the data driver IC 356 via the data pad 130 . The data pad 130 is extended from the data line 104 to thereby get structure in which a titanium Ti and a tungsten (W) included to the data line are exposed. The data drive IC 356 and the data pad 130 are packaged for protection thereof by the package mold material 252 .
[0114] In particular, the data line 104 , the drain electrode 112 , the pixel electrode 114 and the storage electrode 122 have a double-layer structure of metal layers stacked with a first and a second metal layers 154 and 156 . One metal layer of the metal layers is made of any metal that has a relatively high strength and corrosion resistance such as a titanium (Ti) and a tungsten (W). Whereas, another metal layer is made of a low resistance metal such as an aluminum (Al) system metal, a molybdenum (Mo) and a copper (Cu) that are generally employed as a gate metal.
[0115] In this connection, in case where the first metal layer 154 is made of any metal having a high strength and corrosion resistance, the data pad 130 has structure in which the second metal layer 156 of an upper portion is removed and the first metal layer 154 of a lower portion is exposed. On the other hand, in case where the second metal layer 156 is made of any metal having a high strength and corrosion resistance, the data pad 130 has structure in which the second metal layer 156 of an upper portion is exposed.
[0116] [0116]FIGS. 7A and 7B are a plan view and a sectional view for explaining a first mask process employed in a manufacturing method of the thin film transistor array substrate of horizontal electric applying type shown in FIGS. 4 and 5, respectively.
[0117] As shown in FIGS. 7A and 7B, a first conductive pattern group including the gate line 102 , the gate electrode 108 and the gate pad 124 , the common line 116 , the common electrode 118 and the common pad 136 is formed on the lower substrate 145 using the first mask process.
[0118] There will be explained the first mask process in detail with reference to FIGS. 8A to 8 C.
[0119] As shown in FIG. 8A a first gate metal layer 142 and a second gate metal layer 144 are sequentially formed on the upper substrate 145 by a deposition method such as a sputtering, to thereby form a gate metal layer of double-layer structure. Herein, any one of the first gate metal layer 142 and the second gate metal layer 144 is made of any metal that has a relatively high strength and corrosion resistance such as a titanium (Ti) and a tungsten (W), whereas another metal layer is made of a metal such as an aluminum (Al) system metal, a molybdenum (Mo) and a copper (Cu). Subsequently, a photo-resist film is entirely formed on the second gate metal layer 144 and then a first mask 300 is arranged on the lower substrate 145 as shown in FIG. 8B. The first mask 300 comprises a mask substrate 304 which is a transparent material and a cut-off part formed on a cut-off region P 2 of the mask substrate 304 . Herein, region in which the mask substrate 304 is exposed becomes an exposure region P 1 . The photo-resist film is exposed using the first mask 300 as set forth above and developed, to thereby form the photo-resist pattern 306 in the cut-off region P 2 corresponding to the cut-off part 302 of the first mask 300 . The first and the second gate metal layer 142 and 144 are patterned by an etching process using the photo-resist pattern 306 , to thereby form the first conductive pattern group including the gate line, the gate electrode 108 , the gate pad 124 , the common line 116 , the common electrode 118 and the common pad 136 as shown in FIG. 8C.
[0120] [0120]FIGS. 9A and 9B are a plan view and a sectional view for explaining a second mask process employed in the manufacturing method of the thin film transistor array substrate of horizontal electric applying type according to the embodiment of the present invention, respectively.
[0121] At first, a gate insulating film 146 is formed on the lower substrate 145 provided with the first conductive pattern group by deposition method such as the plasma enhanced chemical vapor deposition (PECVD) or sputtering. The gate insulating film 146 is made of an inorganic insulating material such as silicon oxide (SiO x ) or silicon nitride (SiN x ).
[0122] Further, as shown in FIGS. 9A and 9B, a semiconductor pattern group including an active layer 148 and the ohmic contact layer 150 , and a second conductive pattern group including the data line 104 , the drain electrode 112 , the pixel electrode 114 , the data pad 130 and the storage electrode 122 are formed on the gate insulating film 146 using the second mask process.
[0123] There will be explained the second mask process in detail with reference to FIGS. 10A to 10 F.
[0124] As shown in FIG. 10A, on the gate insulating film 146 , a first semiconductor layer 147 , a second semiconductor layer 149 , a first and a second source/drain metal layer 154 and 156 are sequentially provided by deposition techniques such as the plasma enhanced chemical vapor deposition (PECVD) and the sputtering, etc. Herein, the first semiconductor layer 147 is made of an amorphous silicon that an impurity is not doped and the second conductor layer 149 is made of amorphous silicon that an impurity of a N type or P type is doped. Any one of the first and the second source/drain metal layers 154 and 156 is made of any metal that has a relatively high strength and corrosion resistance such as a titanium (Ti) and a tungsten (W), whereas another metal layer is made of any metal such as an aluminum (Al) system metal, a molybdenum (Mo) and a copper (Cu).
[0125] Thereafter, a photo-resist film is formed on the second source/drain metal layer 156 and then a second mask 160 used for a partial exposure is arranged on the lower substrate 145 as shown in FIG. 10B. The second mask 160 comprises a mask substrate 162 which is of a transparent material, a cut-off part 164 formed on a cut-off region P 2 of the mask substrate 162 and a diffractive exposure part 166 (or a semi-transmitting part) formed on a partial exposure region P 3 of the mask substrate 162 . Herein, a region in which the mask substrate 162 is exposed becomes an exposure region P 1 . The photo-resist film is exposed using the second mask 160 as set forth above and then developed, to thereby form the photo-resist pattern 168 which has a stepped part in the cut-off region P 2 and the partial exposure region P 3 corresponding to the diffractive exposure part 166 and cut-off part 164 of the second mask 160 . That is, the photo-resist pattern 168 formed in the partial exposure region P 3 has a second height H 2 that is lower than a first height H 1 of the photo-resist pattern 168 formed in the cut-off region P 2 .
[0126] Subsequently, the first and the second source/drain metal layer 154 and 156 are patterned by a wet etching process using, as a mask, the photo-resist pattern 168 , so that the second conductive pattern group including the data line 104 , the drain electrode 112 connected to the data line 104 , the pixel data 114 , the storage electrode 122 and the data pad 130 is formed as shown in FIG. 10C.
[0127] Thereafter, the first semiconductor layer 147 and the second semiconductor layer 149 are patterned by a dry etching process using the photo-resist pattern 168 as a mask to thereby provide the ohmic contact layer 150 and the active layer 148 along the second conductive pattern group as shown in FIG. 10D. Next, the photo-resist pattern 168 formed with the second height H 2 in the partial exposure region P 3 is removed by the ashing process using an oxygen (O 2 ) plasma, whereby the photo-resist pattern 168 formed with the first height H 1 in the cut-off region P 2 has a lowered height. The partial exposure region P 3 , that is, the first and the second source/drain metal layers 154 and 156 formed at channel portion of the thin film transistor are removed by etching process using the photo-resist pattern 168 . For instance, in case where the second source/drain metal layer 156 is made of a molybdenum Mo and the first source/drain metal layer 154 is made of a titanium Ti, the second source/drain metal layer 156 is removed in the channel portion by a dry etching process and the first source/drain metal layer 154 is removed by a wet etching process in the channel portion. On the contrary, in case where the second source/drain metal layer 156 is made of a titanium Ti and the first source/drain metal layer 154 is made of a molybdenum Mo, the second source/drain metal layer 156 is removed by a wet etching process in the channel portion and the first source/drain metal layer 154 is removed by a dry etching process in the channel portion. Accordingly, the drain electrode 112 is separated from the data line 104 including the source electrode. Thereafter, the ohmic contact layer 150 is removed by a dry etching process using the photo-resist pattern 168 to thereby expose the active layer 148 .
[0128] Further, a remainder of the photo-resist pattern 168 left on the second conductive pattern group is removed by a stripping process as shown in FIG. 10E.
[0129] Thereafter, a passivation film 152 is formed on the gate insulating film 146 having the second conductive pattern group thereon. The passivaion film 152 is made of an inorganic insulating material such as the gate insulating film 146 or an organic insulating material having a small dielectric constant such as an acrylic organic compound, BCB (benzocyclobutene) or PFCB (perfluorocyclobutane), etc.
[0130] Subsequently, an aliment film (not shown) is formed on the passivation film 152 in a display area except for a pad region in which the gate pad 124 , the data pad 130 and the common pad 136 are located on the thin film transistor having the passivation film 152 .
[0131] [0131]FIGS. 11A and 11B are a plan view and a sectional view for representing a pad opening process exposing a pad using a color filter array substrate as a mask, respectively.
[0132] As shown in FIG. 11A and FIG. 11B, the gate pad 124 , the common pad 136 and data pad 130 is exposed using the pad opening process.
[0133] The pad opening process will be described in detail with reference to FIGS. 12A to 12 B.
[0134] On the lower substrate 145 , the thin film transistor array substrate having the thin film transistor array thereon formed using the first and the second mask process and the color filter array substrate formed using a separate process are prepared, and combined and then the thin film transistor array substrate and the color filter array substrate 212 are combined using a sealant 250 as shown in FIG. 12A. In this case, the color filter array substrate 212 is combined with the thin film transistor array substrate so as to expose a pad region where the gate pad 124 , the data pad 130 and the common pad 136 are formed on the thin film transistor array substrate.
[0135] Subsequently, the passivation film 152 and the gate insulating film 146 are patterned in the way of an etching process using the color filter array substrate as a mask such that the gate pad 124 , the common pad 130 and the data pad 130 are exposed as shown in FIG. 12B.
[0136] The gate pad 124 , the data pad 130 and the common pad 136 have structure in which a metal layer with a high strength and corrosion resistance. In this case, the gate pad 124 , the data pad 130 and the common pad 136 have two structures as shown in FIGS. 13 and 14.
[0137] For instance, in case where the first gate metal layer 142 of a lower portion is made of a titanium Ti and the second gate metal layer 144 of an upper portion is made of a molybdenum Mo, the gate pad 124 and the common pad 136 are consisted of only the first gate metal layer 142 of the lower portion as shown in FIG. 13. This is because the second gate metal layer 144 of the upper portion is removed during the pad opening process.
[0138] On the contrary, in case where the first gate metal layer 142 of the lower portion is made of a molybdenum Mo and the second gate metal layer 144 of the upper portion is made of a titanium Ti, the gate pad 124 and the common pad 136 have a double-layer structure of metal layers in which the first and the second gate metal layers 142 and 144 are stacked as shown in FIG. 14. Also, the gate pad 124 and the common pad 136 have structure in which the gate metal layer 144 of the upper portion is exposed through the use of the pad opening process.
[0139] Further, in case where the first source/drain metal layer 154 of the lower portion is made of a titanium Ti and the second source/drain metal layer 156 of the upper portion is made of a molybdenum Mo, the data pad 130 is consisted of only the first source/drain metal layer 154 of the lower portion as shown in FIG. 13. This is because the second source/drain metal layer 156 is removed during the pad opening process.
[0140] On the contrary, in case where the first source/drain metal layer 154 of the lower portion is made of a molybdenum Mo and the second source/drain metal layer 156 is made of a titanium Ti, the data pad 130 has a double-layer structure of metal layers in which the first and the second source/drain metal layers 154 and 156 are stacked as shown in FIG. 14. Also, the data pad 130 has structure in which the source/drain metal layer 156 of the upper portion is exposed through the use of the pad opening process.
[0141] As shown in FIG. 15A and FIG. 15B, the exposed pads 124 and 130 of the pad region on the lower substrate 145 are directly contacted with the drive ICs 350 and 356 via the bump 260 and 286 . That is, the output terminal 262 of the gate drive IC 350 is contacted with the gate pad 124 via the output bump 260 and the output terminal 284 of the data drive IC 356 is contacted with the data pad 130 via the output bump 268 . In this case, the gate pad 124 and the data pad 130 have the exposed structure of metal layer that has a relatively high strength and corrosion resistance are directly contacted with their corresponding drive ICs 350 and 356 such that corrosion of the exposed metal layer is prevented.
[0142] On an area except for a COG connector 358 of the lower substrate 145 on which the gate drive IC 350 and the data drive IC 356 are mounted, a first package mold material 252 is formed as shown in FIG. 16A and FIG. 16B. The first package mold material 252 is formed to partially capsulate the signal supplying line 208 , the gate drive IC 350 , the gate pad 124 , the data drive IC 356 and the data pad 130 as exposed. Otherwise the first package mole material is formed to capsulate, an entirely exposed area on lower substrate 145 not being overlapped with the upper substrate 200 , that is, the signal supplying line 208 , the gate drive IC 350 and the data drive IC 356 .
[0143] Subsequently, the COG connector 358 connected to the signal supplying line 208 is connected with the FPC 354 using the TAB process as shown in FIG. 17A and FIG. 17B. That is, an input pad of the FPC 354 is connected to the PCB 352 and an output pad of the FPC 354 is connected to the COG connector 288 . Further, any one of output pads 282 of the FPC 354 is connected to the common pad 136 using the ACF 182 including the conductive ball 184 to thereby supply the reference voltage for driving the liquid crystal to the common line 116 . The FPC 354 supplies gate control signals and power source signals from timing controller and a power source portion on the PCB 352 to the corresponding drive ICs 350 and 356 .
[0144] Next, a second package mold material 372 is formed at a boundary portion of the COG connector 358 and the FPC 354 and a boundary of the lower substrate 145 and the FPC 354 as shown in FIG. 18A and FIG. 18B. The second package mold material 372 is packaged for protecting the boundary portion of the COG connector 358 and the FPC 354 as shown in FIG. 18A and the boundary of the lower substrate 145 and the FPC 354 as shown in FIG. 18B.
[0145] As described above, according to the thin film transistor array substrate of horizontal electric field applying type and the manufacturing method of the present invention, the pixel electrode is formed as an identical metal to the drain electrode, and the pads have the structure wherein a metal layer having a high strength and corrosion resistance is exposed in order to prevent the defect caused by the opening.
[0146] Further, the thin film transistor array substrate of horizontal electric field applying type and the fabricating method of the present invention combine the thin film transistor array substrate formed using the two-round mask process and the color filter array substrate and then expose the pad to contact with the drive IC using the pad opening process. Accordingly, according to the thin film transistor array substrate of horizontal electric field applying type and the fabricating method thereof according to the present invention, it is possible to manufacture the thin film transistor array substrate using the two-round mask process and therefore to simplify the structure and process of the thin film transistor array substrate, to thereby reduce the manufacturing cost and improve the manufacture yield.
[0147] Moreover, according to the liquid crystal display of horizontal electric applying type and the manufacturing method the present invention, a drive IC mounted on a substrate by a COG system directly is directly connected to a pad, the drive IC and the pad as connected are packaged using a mold material. Accordingly, it is possible to protect the drive IC and the pad from exterior substances and to prevent a corrosion of an entirely exposed signal supplying line and a side exposed pad.
[0148] Although the present invention has been explained by the embodiments shown in the drawings described above, it should be understood to the ordinary skilled person in the art that the invention is not limited to the embodiments, but rather that various changes or modifications thereof are possible without departing from the spirit of the invention. Accordingly, the scope of the invention shall be determined only by the appended claims and their equivalents.
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A liquid crystal display using horizontal electric field and a method of fabricating the liquid crystal display device that are capable of reducing the number of mask processes are provided.
The liquid crystal display of horizontal electric field applying type according to the present invention includes: a thin film transistor array substrate, wherein the thin film transistor array substrate includes an effective display area having a gate line, a common line parallel to the gate line, a data line intersected and isolated with the gate line and the common line with a gate insulating film therebetween to define a pixel area, a thin film transistor formed on each intersection of the gate line and the data line, a passivasion film for protecting the thin film transistor, a common electrode formed in the pixel area and connected to the common line and a pixel electrode connected to the thin film transistor and formed to produce horizontal electric field along with the common electrode in the pixel area, and a pad area having a gate pad formed with at least one conductive layer included in the gate line, a data pad formed with at least one conductive layer included in the data line, a common pad formed with at least one conductive layer included in the common line, which are formed on a lower substrate to form the thin film transistor array substrate; a color filter array substrate combined with the thin film transistor array substrate as facing each other; a driving integrated circuit mounted on the substrate in order to directly connect to any one of the gate pad and the data pad; and a package mold the driving integrated circuit.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is based on and hereby claims priority to German Application No. 19942178.1 filed on 3 Sep. 1999, the contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method for conditioning a database for automatic speech processing, as well as a method for training a neural network for assigning graphemes to phonemes for automatic speech processing, and a method for assigning graphemes to phonemes in the synthesization of speech or in the recognition of speech.
2. Description of the Related Art
It is known to use neural networks for synthesizing speech, the neural networks converting a text, which is represented in a sequence of graphemes, into phonemes which are converted into the corresponding acoustic sounds by an appropriate speech output device. Graphemes are letters or combinations of letters which in each case are assigned a sound, the phoneme. The neural network must be trained before being used for the first time. This is normally performed by using a database which contains the grapheme/phoneme assignments, it being established thereby which phoneme is assigned to which grapheme.
The setting up of such a database constitutes a substantial outlay on time and mental effort, since databases of this type can usually only be constructed with the aid of a language expert.
SUMMARY OF THE INVENTION
The object of the invention is to create a method with the aid of which it is possible in a simple way to set up a database containing grapheme/phoneme assignments.
The method according to the invention for conditioning a database for automatic speech processing procedes from a database which contains words in the form of graphemes and phonemes. Such databases already exist for most languages. The databases are dictionaries which contain the words in script (graphemes) and in phonetic transcription (phonemes). However, these databases lack the assignment of the individual phonemes to the corresponding graphemes. This assignment is executed automatically according to the invention by the following steps:
a) assigning the graphemes to the phonemes of all the words which have the same number of graphemes and phonemes, the graphemes and phonemes being assigned to one another in pairs, b) assigning the graphemes to the phonemes of all the words which have more graphemes than phonemes, all the graphemes firstly being assigned to the phonemes in pairs until an assignment error arises on the basis of the assignments determined hitherto, or there are present only at the end of the word one or more graphemes to which no phoneme is assigned, and combining a plurality of graphemes to form a grapheme unit and assigning a grapheme to the phoneme unit, and c) assigning the graphemes to the phonemes of all the words which have fewer graphemes than phonemes, a plurality of phonemes being combined to form a phoneme unit, and a single grapheme being assigned to them in such a way that the remaining grapheme/phoneme assignments of the word to be analyzed correspond to the assignments found under a) and b), d) assigning the words hitherto not assignable, the words being examined in terms of the phoneme units determined under c) and/or the grapheme units determined under b), and the phonemes are assigned to the graphemes while taking account of the phoneme unit and/or grapheme units, and there being executed at least after step a) a correction step with the aid of which assignments of words which contradict the further assignments determined in step a) are erased.
According to the invention, the first step is to examine words which have the same number of graphemes and phonemes. The graphemes of these words are assigned to the phonemes in pairs, the assignments of the words which contradict the further assignments being erased in a correction step following thereupon.
A large number of the words can be processed with the aid of this first assignment operation and, in addition, statistically significant assignments can be achieved which permit checking in the correction step and which also permit checking of the further assignments to be set up in the subsequent steps.
Thereafter, those words are examined in the case of which the number of phonemes differs from the number of graphemes. In the case of words with more graphemes than phonemes, a plurality of graphemes are combined to form grapheme units, and phonemes are combined to form phoneme units in the case of words with fewer graphemes than phonemes.
After termination of these steps, the words not hitherto assignable are examined, account being taken in this case of the determined phoneme units and/or the determined grapheme units.
Consequently, the method according to the invention is used to set up step by step an “assignment knowledge” which is based initially on pairwise grapheme/phoneme assignments and into which grapheme units and phoneme units are also incorporated in the course of the method.
The method according to the invention can be applied to any desired language for which there already exists an electronically readable database which contains words in the form of graphemes and phonemes, there being no need for an assignment between the phonemes and graphemes. The use of expert knowledge is not necessary, since the method according to the invention is executed fully automatically.
It is then possible to use the database set up according to the invention to train a neural network with the aid of which the grapheme/phoneme assignments are executed automatically in synthesizing or recognizing speech.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and advantages of the present invention will become more apparent and more readily appreciated from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a flowchart of an exemplary embodiment of the method according to the invention,
FIG. 2 is a block diagram of a neural network for assigning graphemes to phonemes, and
FIG. 3 is a block diagram of a device for carrying out the method according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.
The method according to the invention serves for conditioning a database for speech synthesis, the starting point being an initial database that contains words in the form of graphemes and phonemes. Such an initial database is any dictionary that contains words both in script (grapheme) and in phonetic transcription (phonemes). However, these dictionaries do not contain an assignment of the individual graphemes to the respective phonemes. The purpose and aim of the method according to the invention is to set up such an assignment.
An exemplary embodiment of the method according to the invention is illustrated in a flowchart in FIG. 1 . The method is started in a step S 1 .
Step S 2 examines all words that have the same number of graphemes and phonemes. The graphemes of these words are assigned to the corresponding phonemes in pairs.
Such a pairwise assignment is executed, for example, for the English word “run”, which can be represented in the following way with the aid of its graphemes and phonemes:
Graphemes: r u n Phonemes: r A n
In the case of “run”, the grapheme “r” is assigned to the phoneme “r”, the grapheme “u” to the phoneme “A”, and the grapheme “n” to the phoneme “n”. In the case of this pairwise assignment, each individual grapheme is therefore respectively assigned to a single phoneme. This is executed for all words that have the same number of phonemes and graphemes.
In the subsequent step S 3 , a correction is executed which erases the assignments of the words that contradict the further assignments determined in step S 2 . For this purpose, the frequencies of the individual grapheme/phoneme assignments are detected, and grapheme/phoneme assignments which only seldom occur are erased. If the frequency of a specific grapheme/phoneme assignment is below a predetermined threshold value, the corresponding grapheme/phoneme assignments are erased. The threshold value is, for example, in the range of frequency from 10 to 100. The threshold value can be adjusted as appropriate depending on the size of the vocabulary of the initial database, a higher threshold value being expedient in the case of larger initial databases than in the case of smaller initial databases.
An example of such a contradictory grapheme/phoneme assignment is the English word “fire”:
Graphemes: f i r e Phonemes: f l @ r
The assignment of the grapheme “r” to the phoneme “@”, and the assignment of the grapheme “e” to the phoneme “r” are incorrect. These two assignments occur very seldom, for which reason their frequency is lower than the threshold value, and so they are erased in step S 3 . In addition, the word “fire” is marked again in step S 3 as non-assigned, so that it can be re-examined in a later assignment step.
Words which have more graphemes than phonemes are examined in step S 4 , in each case one grapheme being assigned to one phoneme in the reading direction (from left to right), and the remaining graphemes being combined to form a grapheme unit with the last grapheme that has been assigned to a phoneme. The example of a word that is correctly assigned in this way is the English word “aback”:
Graphemes: a b a ck Phonemes: x b @ k
In step S 5 following thereupon, a correction is executed in turn with the aid of which assignments are erased that contradict the assignments determined hitherto, that is to say assignments that have only a low frequency. Step S 5 is therefore identical to step S 3 .
In step S 6 , the words that have more graphemes than phonemes and could not be correctly assigned in step S 4 are examined anew, an individual grapheme being assigned in each case to an individual phoneme in the reading direction (from left to right). Each individual assignment is checked as to whether it corresponds to the assignments determined hitherto. If this checking reviews that a grapheme/phoneme assignment does not correspond to the previous assignments, that is to say does not have the required frequency, the method reverts to the last grapheme/phoneme assignment and joins the grapheme of this grapheme/phoneme assignment to the next grapheme in the reading direction to form a grapheme unit. The remaining phonemes and graphemes are then assigned to one another again individually, each individual grapheme/phoneme assignment being checked, in turn.
One or more grapheme units can be generated inside a word during this method step, the grapheme units comprising two graphemes as a rule. However, it is also possible that the grapheme units can comprise three or more graphemes.
A word in which step S 6 leads to a successful assignment is, for example, the English word “abasement”:
Graphemes: a b a se m e n t Phonemes: x b e s m i n t
In the case of “abasement”, the pairwise assignment proceeds correctly up to the grapheme “e”, which is firstly assigned to the phoneme “m”. This assignment contradicts the assignments determined hitherto, for which reason the method converts to the last successful assignment of the grapheme “s” to the phoneme “s”, and joins the graphemes “s” with the grapheme “e” to form the grapheme unit “se”. The further pairwise assignment of the graphemes to the phonemes corresponds again to the assignments determined hitherto, for which reason they are executed correspondingly.
The words that were examined in step S 6 and have not been assigned with complete success are marked in step s 7 , and their assignments are erased, in turn.
In step S 8 , the words that have more graphemes than phonemes and could not be correctly assigned in steps S 4 and S 6 are examined anew, an individual grapheme being assigned in each case to an individual phoneme firstly in the reading direction (from left to right). Each individual assignment is checked, in turn, as to whether it corresponds to the assignments determined hitherto. If this check shows that a grapheme/phoneme assignment does not correspond to the previous assignments, that is to say that the number of the frequency is below the predetermined threshold value, individual graphemes are assigned to individual phonemes counter to the reading direction (from right to left). If, in the case of this method, only one phoneme is left over that cannot be assigned a grapheme, the remaining graphemes are combined to form a grapheme unit and assigned to the one phoneme.
A grapheme unit can be generated inside a word in this method step.
A word in the case of which step S 8 leads to a successful assignment is, for example, the English word “amongst”:
Graphemes: a m o ng s t Phonemes: x m A G s t
In the case of “amongst”, the pairwise assignment from left to right is performed correctly up to the grapheme “n”, which is firstly assigned to the phoneme “G”. This assignment contradicts the assignments determined hitherto, for which reason a pairwise assignment is executed from right to left. This assignment proceeds correctly up to the grapheme “g”, which is initially assigned to the phoneme “G”. This assignment contradicts the assignment determined hitherto. The phoneme “G” is left over as the only phoneme that cannot be assigned to a grapheme. This phoneme “G” is now assigned to the remaining graphemes “n” and “g”, which are combined to form a grapheme unit.
The words examined in step S 8 , which have not been assigned with complete success, are marked in step S 9 and their assignments are erased, in turn.
The words that have fewer graphemes than phonemes are examined in step S 10 , the individual graphemes being assigned in pairs to the individual phonemes, the graphemes also being assigned to the phonemes adjacent to the assigned phonemes. The respective frequency of all these assignments is determined, and if it is established that a grapheme can be assigned to the two adjacent phonemes with a high frequency, these two phonemes are combined to form a phoneme unit if the two phonemes are two vowels or two consonants.
A word in which step S 10 leads to a correct assignment is, for example, the English word “axes”:
Graphemes: a x e s Phonemes: @ ks i z
In the case of “axes”, the assignments of the grapheme “x” to the phonemes “k” and “s” respectively yields a frequency that is above a predetermined threshold value, so that these two phonemes are combined to form the phoneme unit “ks”. The remaining graphemes and phonemes are assigned in pairs, in turn.
It is also possible in step S 10 that a plurality of phoneme units are formed, or that the phoneme units also comprise more than two phonemes.
A correction is carried out in turn in step S 11 in the case of which the assignments that seldom occur are erased, and the words in which these contradictory assignments have been established are marked as non-assigned. Step S 11 corresponds essentially to steps S 3 and S 5 , although in this case account is also taken of the grapheme/phoneme assignments determined up to step S 10 .
Step S 12 corresponds essentially to step S 10 , that is to say phoneme units are formed from adjacent phonemes, the phoneme units not being limited in step S 12 to two consonants or two vowels, but also being capable of containing a mixture of vowels and consonants.
A correction operation that corresponds to step S 11 is carried out in turn in step S 13 , account being taken of all grapheme/phoneme assignments determined in the interim.
The phoneme units determined in steps S 10 and S 12 are used in step S 14 in order to re-examine words whose graphemes could not be correctly assigned to the phonemes, use being made, for adjacent phonemes, of a phoneme unit that exists for them already. It is also possible as an option to take account of the previously determined grapheme units. Should no use be made of this option, grapheme units can be formed here anew in accordance with the methods according to steps S 4 , S 6 and S 8 .
A word that shows the assignment in accordance with step S 14 is the English word “accumulated”:
Graphemes: a cc u m u l a t e d Phonemes: x k yu m yx l e t l d
In the case of this word, the phonemes “y” and “u” or “y” and “x” are initially replaced by the phoneme units “yu” and “yx”, respectively. Since these phoneme units have already been determined in the preceding steps, use is made in step S 14 of the option that it is also possible to take account of the grapheme units, and so the grapheme unit “cc” is used for the two graphemes “c” and “c”. The pairwise assignments of the individual graphemes or grapheme units to the individual phonemes or phoneme units yields a correct assignment.
If no use is made of the option of taking account of the grapheme units then, as is the case in step S 6 , the individual graphemes are assigned to the individual phonemes or phoneme units, an assignment contradicting the previous assignments occurring in the present case with the assignment of the grapheme “c” to the phoneme unit “yu”. This contradictory assignment is established, and the grapheme “c” is combined with the preceding grapheme “c” to form “cc”. This leads, in turn, to a correct assignment of the graphemes to the phonemes.
A check is made, in turn, in step S 15 as to whether contradictory assignments have arisen. If such contradictory assignments are established, they are erased together with the further assignments of the respective word.
The method is terminated with the step S 16 .
The number of the contradictory assignments determined in step S 15 is a feature of the quality of the conditioning of the initial database, obtained by the method, with the individual grapheme/phoneme assignments.
It was already possible for the method according to the invention to be used very successfully in automatically setting up a database for the German language, an assignment database with a total of 47 phonemes and 92 graphemes having been constructed. In setting up the database for the English language, which has a substantially more complicated grapheme/phoneme assignment, 62 phonemes and 222 graphemes resulted whose assignments are not as good as in the case of the German language. The larger number of graphemes in the English language complicates their processing. It can therefore be expedient to introduce a zero phoneme, that is to say a phoneme without a sound. Such a zero phoneme can be assigned, for example, to the English grapheme unit “gh”, which occurs in the English language in a voiceless fashion in combination with the graphemes “ei”, “ou” and “au”. If no such zero phoneme was introduced, it would be necessary for the phonemes “eigh”, “ough” and “augh” to be introduced in addition to the graphemes “ei”, “ou” and “au”. The zero phoneme permits a reduction in the number of the graphemes, since “eigh”, “ough” and “augh” can be replaced respectively by “ei”, “ou” and “au” in combination with “gh”. The reliability of the method can be raised thereby. In particular, a smaller number of phonemes and/or graphemes permits a simpler, faster and more reliable application in the case of a neural network that is trained by the database set up with the aid of the method according to the invention.
Such a neural network, which has five input nodes and two output nodes, is illustrated schematically in a simplified fashion in FIG. 2 . Three consecutive letters B 1 , B 2 and B 3 of a word that is to be converted into phonemes are input at three of the five input nodes. There are two nodes on the output side, one of the two outputting the respective phoneme Ph, and the other node outputting a grouping Gr. The grouping GR 1 last output and the phoneme Ph 1 last output are input at the two further input nodes.
This network is trained with the words of the database conditioned using the method according to the invention, the grapheme/phoneme assignments of which database do not constitute a contradiction to the remaining grapheme/phoneme assignments, that is to say the words whose graphemes could be correctly assigned to the phonemes.
The neural network determines a phoneme for the middle letter B 2 in each case, account being taken of the respectively preceding letter and subsequent letter in the context, and of the phoneme Ph 1 preceding the phoneme to be determined. If the two consecutive letters B 2 and B 3 constitute a grapheme unit, the result is an output of two for the grouping Gr. If the letter B 2 is not a constituent of a grapheme unit consisting of a plurality of letters, a one is output as grouping Gr.
Account is taken of the respectively last grouping Gr 1 on the input side, no phoneme Ph being assigned to the middle letter B 2 in the case of a grouping of Gr 1 of two, since this letter has already been taken into account with the last grapheme unit. The second letter of the grouping is skipped in this case.
During training of the neural network, the values for the input nodes and for the output nodes are, as is known per se, prescribed for the neural network, as a result of which the neural network acquires the respective assignments in the context of the words.
It can be expedient to provide more than three letters at the input side of the neural network, in particular in the case of languages such as the English language in which a plurality of letters are used to represent a single sound. For the German language it is expedient to provide three or five nodes at the input side for inputting letters, whereas for the English language five, seven or even nine nodes can be expedient for inputting letters. Grapheme units with up to five letters can be handled given nine nodes.
Once the neural network has been trained with the database according to the invention, it can be used for generating language automatically. A device for generating language in which the neural network according to the invention can be used is shown schematically in FIG. 3 .
This device is an electronic data processing device 1 with an internal bus 2 , to which a central processor unit 3 , a memory unit 4 , an interface 5 and an acoustic output unit 6 are connected. The interface 5 can make a connection to a further electronic data processing device via a data line 8 . A loudspeaker 7 is connected to the acoustic output unit 6 .
The neural network according to the invention is stored in the memory unit 4 in the form of a computer program that can be run by the central processor unit 3 . A text which is fed to the electronic data processing device in any desired way, for example, via the interface 5 , can then be fed with the aid of an appropriate auxiliary program to the neural network that converts the graphemes or letters of the text into corresponding phonemes. These phonemes are stored in a phoneme file that is forwarded via the internal bus 2 to the acoustic output unit 6 with the aid of which the individual phonemes are converted into electric signals that are converted into acoustic signals by the loudspeaker 7 .
The method according to the invention for conditioning a database can also be designed with the aid of such an electronic processing device 1 , the method being stored, again, in the form of a computer program in the memory 4 , and being run by the central processor unit 3 , in which case it conditions an initial database that represents a dictionary in script and phonetic transcription, into a database in which the individual sounds, the phonemes, are assigned to the individual letters or letter combinations, the graphemes.
The assignment of the individual graphemes to the individual phonemes can be stored in the conditioned database by blank characters that are inserted between the individual phonemes and graphemes.
The computer programs representing the method according to the invention and the neural network can also be stored on any desired electronically readable data media, and thus be transmitted to a further electric data processing device.
The invention is described above with the aid of an exemplary embodiment with the aid of which a database for speech synthesis is generated. Of course, it is also possible within the scope of the invention to use the database generated according to the invention in speech recognition, since speech recognition methods frequently use databases with grapheme/phoneme assignments.
Speech recognition can be executed, for example, with the aid of a neural network that has been trained with the database set up according to the invention. At the input side, this neural network preferably has three input nodes at which the phoneme converted into a grapheme is input and, if it is present, at least one phoneme preceding in the word and one subsequent phoneme are input. At the output side, the neural network has a node at which the grapheme assigned to the phoneme is output.
Thus, the scope of the invention covers any application of the setting up and use of the database set up according to the invention in the field of automatic speech processing.
The invention has been described in detail with particular reference to preferred embodiments thereof and examples, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
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A neural network can be trained for synthesizing or recognizing speech with the aid of a database produced by automatically matching graphemes and phonemes. First, graphemes and phonemes are matched for words which have the same number of graphemes and phonemes. Next, graphemes and phonemes are matched for words that have more graphemes than phonemes in a series of steps that combine graphemes with preceding phonemes. Then, graphemes and phonemes are matched for words that have fewer graphemes than phonemes. After each step, infrequent and unsuccessful matches made in the preceding step are are erased. After this process is completed, the database can be used to train the neural network and graphemes, or letters of a text can be converted into the corresponding phonemes with the aid of the trained neural network.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of application Ser. No. 13/329,785, filed Dec. 19, 2011, the disclosure of which is hereby incorporated in its entirety by reference herein.
TECHNICAL FIELD
[0002] This disclosure relates to the control of mechanical coupling devices, such as clutches, for shafts or other elements of a vehicle driveline.
BACKGROUND
[0003] Certain road vehicles may be driven by an internal combustion engine and/or an electric machine. An electric machine, for example, may be used to drive a vehicle at low speeds. An internal combustion engine and the electric machine may be used to drive the vehicle at high speeds. If the internal combustion engine and electric machine are arranged along a common driveline so as to share a common input shaft to a transmission, a clutch may be used to isolate the internal combustion engine from the electric machine. A clutch may also be used to isolate the internal combustion engine and electric machine from the transmission. Certain clutch control strategies may ensure a smooth transition from one source of motive power to another.
SUMMARY
[0004] A clutch system may be controlled by providing a current to the clutch system to mechanically couple an electric machine and transmission based on a target clutch pressure and a line pressure associated with the transmission, receiving data about an actual clutch pressure, and altering the current based on the data to keep the actual clutch pressure substantially equal to the target clutch pressure as the line pressure varies.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a block diagram of a vehicle.
[0006] FIG. 2 is a plot of transmission line pressure versus time.
[0007] FIG. 3 is a plot of launch clutch pressure versus time.
[0008] FIG. 4 is a plot of input speed for a mechanical oil pump versus time.
DETAILED DESCRIPTION
[0009] Embodiments of the present disclosure are described herein; however, it is to be understood that the disclosed embodiments are merely examples and other embodiments may take various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures may be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, may be desired for particular applications or implementations.
[0010] Referring to FIG. 1 , an automotive vehicle 10 may include an engine 12 , electric machine 14 , transmission 16 , and wheels 18 . The engine 12 may include an output shaft 20 , the electric machine 14 may include input and output shafts 22 , 24 , and the transmission 16 may include input and output shafts 26 , 28 . A disconnect clutch system 30 is arranged to mechanically couple the shafts 20 , 22 so as to mechanically couple the engine 12 and electric machine 14 . A launch clutch system 32 is arranged to mechanically couple the shafts 24 , 26 so as to mechanically couple the electric machine 14 and transmission 16 . The launch clutch system 32 , in other embodiments, may include a torque converter and lock up clutch in parallel with each other. Other arrangements are also contemplated.
[0011] The engine 12 and/or electric machine 14 may be used to drive the wheels 18 via the transmission 16 . Beginning from a stop, for example, the disconnect clutch system 30 may be disabled to isolate the shafts 20 , 22 from each other, the launch clutch system 32 may be enabled to lock the shafts 24 , 26 together, and the electric machine 14 may be activated to cause the wheels 18 to move. As a demand for acceleration increases, the launch clutch system 32 may be caused to slip and the disconnect clutch system 30 may be enabled to lock the shafts 20 , 22 together. The engine 12 may then be started and brought up to a desired speed. The amount of slip experienced by the launch clutch system 32 may then be reduced as the speed of the shafts 20 , 22 , 24 approaches the speed of the shaft 26 .
[0012] The transmission 16 is serviced by an electric oil pump 34 and a mechanical oil pump 36 . The electric machine 14 and electric oil pump 34 are powered by electrical energy stored in a battery 38 . The mechanical oil pump 36 is powered by mechanical energy obtained from the rotation of the output shaft 24 . The electric oil pump 34 is intended to provide oil to the transmission 16 under circumstances in which a rotative speed of the output shaft 24 is not sufficient to provide threshold mechanical energy for proper operation of the mechanical oil pump 36 .
[0013] A check valve 39 may regulate the flow of oil from the electric and mechanical oil pumps 34 , 36 . In the example of FIG. 1 , the check valve 39 is configured such that oil from the electric oil pump 34 will flow to the transmission 16 if a pressure of oil from the mechanical oil pump 36 is less than that of the oil from the electric oil pump 34 (assuming the electric oil pump 34 is active). If the pressure of the oil from the mechanical oil pump 36 is greater than that of the oil from the electric oil pump 34 (assuming the electric oil pump 34 is active), the oil from the electric oil pump 34 will not flow to the transmission 16 .
[0014] A controller system 40 is operatively arranged with the transmission 16 and launch clutch system 32 . That is, the control system 40 may read information associated with the transmission 16 and operate the launch clutch system 32 on the basis thereof. For example, a solenoid and valve (not shown) of the launch clutch system 32 that control clutch pressure to mechanically couple the shafts 24 , 26 may be controlled based on a line pressure from the transmission 16 to the launch clutch system 32 .
[0015] The line pressure is proportional to the oil pressure supplied to the transmission 16 by the electric and/or mechanical oil pumps 34 , 36 . Transitioning from the electric oil pump 34 to the mechanical oil pump 36 as described above (and/or changes in a state of the transmission 16 , such as a concurrent gear shift, etc.) may cause fluctuations in the oil pressure to the transmission 16 and hence, in the line pressure that influences operation of the solenoid and valve (not shown). Drivability issues may occur if these transitory events take place during a zero speed launch of the vehicle 10 that includes a pull up of the engine 12 as the actual line pressure may deviate from its target. Such deviations may cause a torque being transmitted to the wheels 18 to be altered in an undesirable fashion.
[0016] Referring now to FIGS. 2 , 3 and 4 , the line pressure associated with the transmission 16 , launch clutch pressure of the launch clutch system 32 , and input speed to the mechanical oil pump 36 are plotted versus time. (The time axis is not necessarily to scale.) Prior to the vehicle movement initiated event, it is assumed that the engine 12 is off, the line pressure results from operation of the electric oil pump 34 , and a demand for vehicle movement is initiated (e.g., a driver steps on an accelerator pedal (not shown)). In response to the demand for vehicle movement, the controller system 40 generates a current for the solenoid (not shown) of the launch clutch system 32 based on the line pressure. The pressure generated by the launch clutch system 32 increases toward a target as a result.
[0017] As vehicle movement begins, the input speed to the mechanical oil pump 36 increases because the shaft 24 begins to rotate. The mechanical oil pump 36 may begin to operate and thus influence the line pressure. Certain mechanical oil pumps may require some minimum threshold input speed to provide steady output. Such a threshold input speed for the mechanical oil pump 36 is indicated in FIGS. 2 , 3 and 4 . Below this threshold, the mechanical oil pump 36 may not provide steady output. As a result, the line pressure may deviate considerably from its target between the time when vehicle movement is initiated and the threshold input speed for the mechanical pump 36 is achieved. This may result, as mentioned above, in undesirable variations in torque transmitted to the wheels 18 .
[0018] Variations in the line pressure may result in variations in the launch clutch pressure (as indicated by dashed line) because the current provided to the solenoid (not shown) of the launch clutch system 32 is based on the line pressure. That is, a magnitude of the current provided to the solenoid depends on a magnitude of the line pressure. It has been discovered, however, that information about the launch clutch pressure may be used to modify/alter/select the magnitude of the current to the solenoid of the launch clutch system 32 to minimize variations in the launch clutch pressure caused by variations in the line pressure.
[0019] Referring again to FIG. 1 , a pressure sensor 42 is operatively arranged with the launch clutch system 32 so as to be able to detect the launch clutch pressure and is in communication with the controller system 40 . The controller system 40 may thus use this pressure information as a basis for which to further control the launch clutch system 32 . The demand for vehicle movement, for example, may cause the controller system 40 to select a desired launch clutch system pressure and line pressure (and read associated data such as temperature, etc.) as known in the art. On the basis of this information, the controller system 40 may select a corresponding magnitude for current to be supplied to the solenoid (not shown) of the launch clutch system 32 . In certain examples, lookup tables mapping the desired clutch pressure, temperature data, and current magnitude may be used to facilitate the selection. Each of the lookup tables may correspond with a range of desired line pressures. That is, a first lookup table associated with desired line pressures less than a minimum threshold line pressure for non-electric vehicle mode may map values for the desired clutch pressure, temperature data, and current magnitude with each other. A second lookup table associated with desired line pressures greater than the minimum threshold and less than a feed pressure for the valve (not shown) of the launch clutch system 32 may map values for the desired clutch pressure, temperature data, and current magnitude with each other. A third lookup table associated with desired line pressures greater than the feed pressure may map values for the desired clutch pressure, temperature data, and current magnitude with each other. Hence, the desired line pressure determines which of the lookup tables to use. A value for the current magnitude, in other examples, may be obtained by aggregating data between the lookup tables. For a desired line pressure below the minimum threshold and any given desired clutch pressure and temperature, for example, the current magnitude may be found by aggregating (e.g., interpolating) the selected values from the first and second tables. Any suitable/known technique, however, may be used to determine the magnitude for the current.
[0020] The controller system 40 may determine (periodically, continuously, etc.) whether the actual launch clutch pressure deviates from the desired launch clutch pressure. If the actual deviates from the desired, the controller system 40 may alter the current magnitude selected, in this example, from the lookup tables described above. The controller system 40 may reduce the selected current if the actual launch clutch pressure is greater than the desired launch clutch pressure until the actual and desired pressures are substantially equal. Referring to FIG. 2 , an example of such a corrected current magnitude and corresponding corrected actual pressure are illustrated in phantom and solid lines respectively. If the actual launch clutch pressure is less than the desired launch clutch pressure, the controller system 40 may increase the selected current until the actual and desired pressures are substantially equal, etc.
[0021] The controller system 40 may thus learn via the above algorithm the amount by which to alter the selected current based on the amount by which the actual launch clutch pressure deviates from its target. If subsequent variations in launch clutch pressure are observed as the threshold input speed to the mechanical pump 36 continues to increase, the controller system 40 may correct the current magnitude based on the information learned without having to perform closed loop control based on data from the pressure sensor 42 . This learned information, however, may only be valid for a particular instance of a transition from electric vehicle mode to non-electric vehicle mode. Subsequent vehicle launches and/or transitions may each require the closed loop control to be performed to correctly calibrate the system for that launch and/or transition.
[0022] Once the threshold input speed for the mechanical pump 36 is achieved, the line pressure should take on values at least equal to the minimum threshold line pressure for non-electric vehicle mode, the launch clutch pressure should continue to increase towards its final target (to lock the shafts 24 , 26 ), and the input speed to the mechanical pump 36 should continue to increase and allow the launch clutch system 32 to reach maximum torque capacity as the speed of the shaft 24 increases with the engine speed.
[0023] The processes, methods, or algorithms disclosed herein may be deliverable to/implemented by a processing device, controller, or computer, which may include any existing programmable electronic control unit or dedicated electronic control unit. Similarly, the processes, methods, or algorithms may be stored as data and instructions executable by a controller or computer in many forms including, but not limited to, information permanently stored on non-writable storage media such as ROM devices and information alterably stored on writeable storage media such as floppy disks, magnetic tapes, CDs, RAM devices, and other magnetic and optical media. The processes, methods, or algorithms may also be implemented in a software executable object. Alternatively, the algorithms may be embodied in whole or in part using suitable hardware components, such as Application Specific Integrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs), state machines, or other hardware components or devices, or a combination of hardware, software and firmware components.
[0024] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure and claims. As previously described, the features of various embodiments may be combined to form further embodiments of the invention that may not be explicitly described or illustrated. While various embodiments may have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics may be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes may include, but are not limited to: cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, embodiments described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and may be desirable for particular applications.
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A vehicle includes a motive power source, a transmission, and a clutch system. The vehicle further includes a controller that causes the clutch system to generate a generally constant clutch pressure to mechanically couple the motive power source and transmission as a line pressure associated with the transmission varies.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 11/534,945 filed on Sep. 25, 2006, incorporated herein by reference in its entirety, which is a continuation of U.S. patent application Ser. No. 10/893,053 filed on Jul. 16, 2004, now U.S. Pat. No. 7,124,792, incorporated herein by reference in its entirety.
[0002] This application is also related to PCT international application serial number PCT/US05/25363 filed on Jul. 18, 2005, and published as WO 2006/20175 on Feb. 12, 2006, incorporated herein by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0003] Not Applicable
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
[0004] Not Applicable
NOTICE OF MATERIAL SUBJECT TO COPYRIGHT PROTECTION
[0005] A portion of the material in this patent document is subject to copyright protection under the copyright laws of the United States and of other countries. The owner of the copyright rights has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the United States Patent and Trademark Office publicly available file or records, but otherwise reserves all copyright rights whatsoever. The copyright owner does not hereby waive any of its rights to have this patent document maintained in secrecy, including without limitation its rights pursuant to 37 C.F.R. § 1.14.
BACKGROUND OF THE INVENTION
[0006] 1. Field of the Invention
[0007] This invention relates to the field of controlling the directional flow of bulk liquids. Bulk liquids are generally held in large containment vessels to be stored or transported. This patent deals with the precise control and distribution of liquids from these containment vessels along with the capability of pumping liquid back into the containment vessel by the means of suction. Additionally this patent deals with a unique method of removing any excess liquid from the hoses and lines in the system to insure that no liquid is spilled on the ground or retained within the hoses.
[0008] Existing methods of pumping and siphoning bulk liquids has in the past been cumbersome where quantities of the liquid are left within the pump, hoses and distribution lines and this liquid is often spilled onto the ground. A great amount of the bulk liquid is in the form of chemicals, fuel and oil products that produce an environmental hazard when spilled. The Environmental Protection Agency (EPA) has endeavored to put strict regulations on the handling and spillage of these liquids. The petroleum tank and containment vessels are extremely regulated, but the pumping systems are not. No standard or performance windows have been made for the installation and capabilities of the pump systems presently in use.
[0009] 2. Description of Related Art
[0010] The new manual bulk liquid pump control and distribution system was designed primarily for the over the road petroleum transportation industry delivering to above the ground tanks, but it has been found to be useful in the handling of a wide variety of other bulk liquids. This patent is not intended be limited in its scope to the petroleum industry only, but has the capability to be effective in the handling of a variety of other bulk liquids. The new manual bulk liquid pump control and distribution system has been designed to revolutionize not only the way bulk liquids are handled by truck tankers but also the way bulk liquids are transferred between containment vessels. Bulk liquids in the petroleum industry consist of gasoline, oil, diesel, aviation-gas, and transmission fluid to anti-freeze, used oil, and more.
[0011] In environmentally sensitive areas such as coast lines, rivers, lakes, ski slopes, parks, wetlands, high water tables or any area where underground tanks cannot be used, there is zero tolerance of a contamination spill. Further, underground tanks must be specially designed, manufactured, installed and monitored to detect and prevent leaks. Accordingly, it is extremely expensive to put a tank underground. In these applications, they are filled by a gravity drop, and no pump is required to deliver fuel to these tanks.
[0012] Most corporate farms, businesses, municipalities, airports, rental car yards, trucking companies, construction companies, bus companies and railroads use above ground storage tanks. This style of tank requires a pump to fill them. The application of federal law requires like vehicles to respond to their own accidents and rollovers. In the case of the petroleum industry, if a vehicle is rolled over and lying on its side, the fuel must be removed before the vehicle is up-righted. The fuel is salvageable and requires a pump to remove it. The railroad locomotives are filled, and tank cars are loaded and unloaded with the use of pumps mounted on trucks. All package oil facilities that purchase bulk oils and package them for retail sale, use above ground tanks and require vehicles with pumps to fill them. All shipyards and container yards use above ground tanks, and they require pumps mounted on trucks to load and unload fuel on the tugs and tankers.
[0013] Presently, not all states are equal in their environmental requirements. California was the first state to have them, and consequently has the highest restrictions with respect to the handling and transportation of hazardous liquids. Many other states have followed suit with similar requirements and the EPA is now beginning to enforce these laws more diligently in all states. The possibility of a trucking company spilling fuel upon disconnecting of the hoses is being greatly scrutinized. There is no longer any tolerance for these types of frequent spills. The manual bulk liquid pump control and distribution system eliminates substantially all spillage in these zero spill environments.
[0014] As regulation of the industry continues to increase, more above ground fuel tanks will be installed to replace underground tanks, resulting in a dramatic increase in above ground pumping applications. Today in California, if you are a jobber that contracts to Chevron, you are required to have a pump installed on your truck to service their customers. That number is growing, and most all new tankers put into service in California will have pumps installed on them. As the agencies tighten the regulations and enforce the environmental laws, more pumps are required to meet the laws governing the above ground fuel storage and handling systems.
[0015] The fuel oil transportation industry and chemical transportation industry have problems that are similar to the petroleum industry. Tankers are no longer used as a single delivery of product to an underground tank and back to the refinery for another partial load. These vehicles and operators must be able to multi-task to survive. These include multiple deliveries per load, both gravity and pump loads, numerous drivers per vehicle, variable products, multitudes of tanks and vessels to deliver to, emergency responses, station pump outs, and railroad deliveries, all of which are just some of the different daily conditions. These are all done under the ever-growing scrutiny of the Environmental Protection Agency, Department of Transportation, and insurance industry.
[0016] The same environmental laws are now being enforced in international markets as well. Islands such as the Dominican Republic are converting to all above ground tanks and are changing their entire transport fleets. They are using a variety of pumps that are put on trucks with no forethought about problems that might be caused. Every single pump is unique and operates differently. This results in daily spills on each and every delivery, which is no longer an accepted practice.
[0017] Accordingly, there is a need for a manual bulk liquid pump control and distribution system which improves upon devices that can transfer bulk liquids and still meet the high standards set by the Environmental Protection Agency, Department of Transportation, the Air Resources Board and the insurance companies. In this respect, 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 to the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. In addition, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
BRIEF SUMMARY OF THE INVENTION
[0018] The manual bulk liquid pump control and distribution system, primarily designed for the petroleum transportation industry, was built by the present inventor with safety and the environment at the forefront. The single flow reversing two-way valve handle controls the flow rate and volume of product and eases the stress of operation of this type of equipment. This design makes the unloading and loading of hazardous liquids as safe and efficient as possible along with the ability of removing all the liquid from the lines and hoses. The unique design meets the demands and the stringent requirements set by the Environmental Protection Agency, Air Resources Board, Department of Transportation, A.S.M.E, and various insurance companies.
[0019] The unique feature of this invention is the compact features and the simplicity of how it operates along with the ability of solving many of the problems of handling bulk petroleum and other similar products where spills have become an ever-present and dangerous environmental problem.
[0020] The present invention is directed to a liquid pump control and distribution system that utilizes a single-handle flow reversing two-way valve for the operational direction of flow and volume, while providing a neutral position for standby. The pump drive will generally be by the means of a clutch-type power takeoff (PTO) from the vehicle engine or an auxiliary engine mounted on the vehicle or on a pallet as a portable device. The system can be operated at a rate of 0 to about 300 gallons per minute and be reversed and controlled with a single motion of the operating handle on the flow reversing two-way valve.
[0021] The pump operates in one direction at a fixed RPM, resulting in longer pump life and safer operation. For added safety, the system utilizes the pump's relief valve for both loading and unloading. It must be understood that a variety of different pumps made by different manufactures will perform the same function of pumping the liquid and remain within the scope of this patent. Since the system has a neutral position when the PTO is engaged, no fluid motion or pressure develops until the system gradually begins to operate after all connections are verified by the operator. When the liquid has been transferred, the residue liquid left in the lines and hoses may be removed by raising the end of the hose up trapping the liquid and manually reversing the two-way valve to the suction position.
[0022] This system uses an aluminum flow reversing two-way valve with a flat plate impeller. The valve allows the flow of the product to be precisely controlled in either direction, along with flow rate and pressure. This gives the operator the ability to control the product regardless of viscosity or volume. The reversing valve uses recessed O rings on the shafts and flange faces to prevent leaks. A crossover line is easily adapted to the system making easy access to both sides of a vehicle. The design allows for the safest pump operation available for proper handling of a wide variety of products during these environmentally sensitive times.
[0023] The system incorporates an easily accessible strainer basket housed within a housing that is inclined so that when the strainer basket cover plate is removed the liquid within does not spill out. An extended handle positions the basket within the chamber so that the flow inters the center of the basket and the cover plate is easily accessible. A unique 110-degree elbow connects the strainer basket housing to the pump positioning the flow reversing two-way valve and valve handle in a convenient and easily accessible location and keeping the system as compact as possible. The strainer basket and housing is designed independently of the particular pump being used making it universal and adaptable to a wide variety of pump configurations.
[0024] A purge valve is connected to the pump outlet, the lowest point in the system, to remove retained liquids once transfer of liquids is complete
[0025] The principal object of the manual bulk liquid pump control and distribution system is to create a unique system that will eliminate substantially all spillage of liquids during the transfer from one containment vessel to a second containment vessel.
[0026] Another object of the manual bulk liquid pump control and distribution system is to create a unique way to move bulk liquids in two different directions through a single flow reversing two-way valve without reversing the direction of the pump drive unit.
[0027] Another object of the manual bulk liquid pump control and distribution system is to create a unique manual system that will control the flow rate and volume of bulk liquids in either direction while the pump is operating at a constant speed with a single valve handle and no electronic control devices.
[0028] Another object of the manual bulk liquid pump control and distribution system is to create a small and compact unit which is easily accessible to an operator.
[0029] Another object of the manual bulk liquid pump control and distribution system is to create a system with a crossover line that will access from both sides of a vehicle.
[0030] Yet another object is to create a manual bulk liquid pump control and distribution system that can be put in a neutral position where no liquid is pumped in either direction.
[0031] And yet, another object is to create a manual bulk liquid pump control and distribution system where the liquid is always forced through the strainer basket in the same direction whether the system is in the discharge or suction mode.
[0032] And still another object is to create a manual bulk liquid pump control and distribution system where the strainer basket in the angled strainer basket housing is easily accessible and will not spill liquid when the access port is opened.
[0033] A further object of this invention is to create a unique system that is adaptable to a variety of different configurations.
[0034] A final object of this invention is to add a new and unique system to the area of transferring bulk liquids from one containment vessel to a second containment vessel while meeting all the new stringent requirements set forth by the Environmental Protection Agency, Department of Transportation, the Air Resources Board and the insurance companies.
[0035] An embodiment of the invention is a pump having an inlet and an outlet, a flow control reversing valve fluidly coupled to the inlet and the outlet of the pump, the reversing valve has a first orifice and a second orifice, the reversing valve has a first position and a second position, where when the reversing valve is in the first position, liquid flows from the first orifice to the second orifice, where when the reversing valve is in the second position, liquid flows from the second orifice to the first orifice, where the outlet of the pump is positioned below the reversing valve and the inlet of the pump, and a purge valve fluidly coupled to and positioned below the outlet of the pump.
[0036] An aspect of the invention is where the reversing valve has a third position, and where when the reversing valve is in the third position, a liquid pressure difference will not develop between the first orifice and the second orifice.
[0037] A further aspect of the invention is where substantially all retained liquid in the reversing valve and in the pump is discharged through the purge valve when the pump is operating, the purge valve is opened, and the reversing valve is moved from the third position to the first position.
[0038] A still further aspect of the invention is a hose having first and second ends, the first end of the hose adapted to couple to the second orifice, and where retained liquid from the hose flows into the reversing valve through the second orifice when the second end of the hose is elevated above the second orifice and the position of the reversing valve is moved from the third position to the second position.
[0039] Another aspect of the invention is where a change in position of the reversing valve between the first position and the second position changes the flow rate of liquid flowing between the first orifice and the second orifice.
[0040] A yet further aspect of the invention is where a change in position of the reversing valve between the first position and the second position changes the liquid pressure difference between the first orifice and the second orifice.
[0041] A still further aspect of the invention is a strainer housing coupled to the inlet of the pump, a strainer basket positioned in the strainer housing, where the strainer housing is fluidly coupled to the reversing valve.
[0042] Another aspect of the invention is where liquid flows in one direction through the strainer basket when the position of the reversing valve is changed between the first position and the second position.
[0043] A still further aspect is a drain plug positioned in the strainer housing.
[0044] A further aspect of the invention is where the pump is a constant speed pump and/or a positive displacement pump.
[0045] A still further aspect of the invention is an indexing pin coupled to the reversing valve, where the position of the reversing valve is restricted to between the first position and the second position by the indexing pin.
[0046] Another aspect of the invention is where the reversing valve is adapted to mount to a vehicle having a liquid reservoir, where the first orifice is adapted to couple to the liquid reservoir, and where the second orifice is adapted to fluidly couple to a liquid receiver.
[0047] A further aspect of the invention is where the reversing valve has a third position, where when the reversing valve is in the third position, a liquid pressure difference will not develop between the first orifice and the second orifice, and where retained liquid in the reversing valve and in the pump is discharged through the purge valve when the pump is operating, the purge valve is opened, and the reversing valve is moved from the third position to the first position.
[0048] Another embodiment of the invention is a valve body having a first, second, third and fourth ports, where the first port is adapted to couple to the inlet of a pump, where the second port is adapted to couple to a first containment vessel, where the third port is adapted to couple to the outlet of the pump, where the fourth port is adapted to couple to a second containment vessel, a valve chamber in the center of the valve body, a valve candle adapted to rotate within the valve chamber, the valve candle having a flat impeller, the valve candle having first, second and third positions, where when the valve candle is in the first position, the impeller directs liquid flow from the second port to the first port, and from the third port to the fourth port, where when the valve candle is in the second position, the impeller directs liquid flow from the fourth port to the first port and from the third port to the second port, and where when the valve candle is in the third position, the impeller allows liquid to flow from the third port to the first port.
[0049] Another aspect of the invention is an indexing pin attached to the valve candle, a valve bonnet coupled to the valve body, indexing ears attached to the valve bonnet, where the indexing ears interact with the indexing pin to limit the turning range of the valve candle.
[0050] A further aspect of the invention is where the valve candle has a top shaft and a bottom shaft, where the top shaft is supported by the valve bonnet, a coil spring positioned on the top shaft between the valve bonnet and the valve candle, a jack screw positioned in the valve body, the jack screw adapted to support the bottom shaft, where the coil spring urges the bottom shaft of the valve candle against the jack screw.
[0051] A still further aspect of the invention is where adjusting the jack screw adjusts the position of the valve candle in the valve chamber.
[0052] A yet further aspect of the invention is a first recessed O ring on the top shaft, the first O ring positioned to seat in the valve bonnet, a second recessed O ring on the bottom shaft, the second recessed O ring positioned to seat in the valve body, and where the first and second recessed O rings are adapted to resist liquid flow along the top and bottom shafts.
[0053] Another aspect of the invention is first, second, third and fourth recessed O rings positioned on the first, second, third and fourth ports respectively, where the first second third and fourth O rings are adapted to resist liquid flow across the face of the ports.
[0054] A further aspect of the invention is a strainer housing adapted to couple to the inlet of the pump, a strainer basket positioned in the strainer housing, where the strainer housing is fluidly coupled to the first port.
[0055] A still further aspect of the invention is where liquid flows in one direction through the strainer basket when the position of the valve candle is changed between the first position and the second position.
[0056] A yet further aspect of the invention is where the valve body is mounted to a vehicle, and where the fourth port is fluidly coupled to a crossover line that will access liquid from both sides of the vehicle.
[0057] Another aspect of the invention is where the second port is adapted to couple to a first containment vessel mounted on the vehicle, and where the crossover line is adapted to couple to a second containment vessel.
[0058] A still further aspect is where the second port is fluidly connected to a second crossover line that will access liquid from both sides of the vehicle.
[0059] A further aspect of the invention is a hose having first and second ends, the first end adapted to couple to the crossover line, and where retained liquid from the hose flows into the valve body through the fourth port when the second end of the hose is elevated above the crossover line and the position of the valve candle is moved from the third position to the second position.
[0060] A further embodiment of the invention is a method of distributing liquid that comprises providing a pump having an inlet and an outlet, providing a two way flow reversing valve having a first, second, third and fourth ports, coupling the pump inlet to the first port, coupling the pump outlet to the third port, coupling a first containment vessel to the second port, coupling a second containment vessel to the fourth port, where the flow reversing valve has a first position and second position, engaging the pump, moving the flow reversing valve to the first position, and distributing liquid from the first containment vessel to the second containment vessel.
[0061] Another aspect of the invention is a method where the flow reversing valve has a third position, where when the flow reversing valve is in the third position, liquid does not flow between the second port and the fourth port, and positioning the flow reversing valve in the third position before the pump is engaged.
[0062] A further aspect of the invention is providing a hose having a first end and second end, coupling the first end of the hose to the fourth port, and coupling the second end of the hose to the second containment vessel.
[0063] a still further aspect of the invention is uncoupling the second end of the hose from the second containment vessel, elevating the second end of the hose above the fourth port, and moving the flow reversing valve to the second position to remove the retained liquid from the hose.
[0064] A yet further aspect of the invention is coupling a purge valve to the pump outlet, disconnecting the second containment vessel from the fourth port, engaging the pump, opening the purge valve, moving the flow reversing valve to the first position thereby discharging retained fluid through the purge valve.
[0065] Another aspect of the invention is providing a strainer housing coupled to the inlet of the pump and coupled to the flow reversing valve, flowing fluid in a first direction through the strainer housing when the flow reversing valve is in the first position, and flowing fluid in the first direction through the strainer housing when the flow reversing valve is in the second position.
[0066] A still further aspect is providing a drain port in the strainer housing and opening the drain port to drain retained liquid from the strainer housing.
[0067] A further aspect of the invention is supporting the first containment vessel on a vehicle, supporting the pump on the vehicle, and supporting the flow reversing valve on the vehicle.
[0068] A still further aspect of the invention is coupling a purge valve to the pump outlet, disconnecting the second containment vessel from the fourth port, engaging the pump, opening the purge valve, moving the flow reversing valve to the first position thereby discharging retained fluid through the purge valve.
[0069] Another aspect of the invention is supporting a third containment vessel from said vehicle; disconnecting the first containment vessel from the second port; connecting the third containment vessel to the second port; engaging the pump; moving the flow reversing valve to the first position; and distributing liquid from the third containment vessel through the fourth port.
[0070] A yet further aspect of the invention is disconnecting the second containment vessel from the fourth port, connecting a liquid source to the fourth port, engaging the pump, moving the flow reversing valve to the second position thereby refilling the first containment vessel from the liquid source.
[0071] Another aspect of the invention is coupling a purge valve to the pump outlet, disconnecting the liquid source from the fourth port, engaging the pump, opening the purge valve, and moving the flow reversing valve to the first position thereby discharging retained fluid through the purge valve.
[0072] Further aspects of the invention will be brought out in the following portions of the specification, wherein the detailed description is for the purpose of fully disclosing preferred embodiments of the invention without placing limitations thereon.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0073] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention and together with the detailed description, serve to explain the principles of this invention.
[0074] FIG. 1 depicts a perspective view of the left side of the manual bulk liquid pump control and distribution system illustrating the directional discharge flow of the bulk liquid with the intake orifice at the top and the discharge at the bottom.
[0075] FIG. 2 depicts a perspective view of a variety of different couplings that can be used to adapt the manual bulk liquid pump control and distribution system into different configurations.
[0076] FIG. 3 depicts a perspective view of the right side of the manual bulk liquid pump control and distribution system illustrating the directional suction flow of the bulk liquid along with the strainer basket partly removed from the strainer housing.
[0077] FIG. 4 depicts a perspective side view of the manual bulk liquid pump control and distribution system illustrating the inclined angle of the strainer basket housing.
[0078] FIG. 5 depicts a perspective view of the left side of the manual bulk liquid pump control and distribution system illustrating one of the alternate configurations with the intake orifice at the bottom and the discharge at the top.
[0079] FIG. 6 depicts a side elevation schematic of a flow reversing two-way valve with the side cut away illustrating the flow in the discharge configuration.
[0080] FIG. 7 depicts a side elevation schematic of a flow reversing two-way valve with the side cut away illustrating the flow in the suction configuration.
[0081] FIG. 8 is an exploded view of another embodiment of a two-way reversing flow control valve for liquid distribution.
[0082] FIG. 9 is a cross section view of the two way reversing flow control valve shown in FIG. 8 .
[0083] FIG. 10 illustrates a side view of another embodiment of a liquid pump control and distribution system with a vane pump.
[0084] FIG. 11 illustrates a side view of a further embodiment of a liquid pump control and distribution system with a gear pump.
[0085] FIG. 12 depicts a perspective view of the left side of the manual bulk liquid pump control and distribution system shown in FIG. 1 illustrating a crossover line mounted inside the interconnecting line.
DETAILED DESCRIPTION OF THE INVENTION
[0086] Referring more specifically to the drawings, for illustrative purposes the present invention is embodied in the apparatus generally shown in FIG. 1 through FIG. 12 . It will be appreciated that the apparatus may vary as to configuration and as to details of the parts, and that the method may vary as to the specific steps and sequence, without departing from the basic concepts as disclosed herein.
[0087] There is seen in FIG. 1 a perspective view of the left side of the manual bulk liquid pump control and distribution system 10 . This view illustrates the directional discharge flow of the bulk liquid with arrows having the intake orifice 12 in the flanged coupling 14 A with a flexible victaulic coupling means 16 at the top of the flow reversing two-way valve 18 . The flow reversing two-way valve 18 is shown with the valve handle 20 to the right in the discharge position. At the bottom of the flow reversing two-way valve 18 , the discharge orifice connects to a 90-degree elbow 22 connected to a T-section 24 having two flexible victaulic coupling means 16 , a conventional mounting flange 26 and cover plate 28 . The flexible victaulic coupling means 16 uses an o-ring seal with a two-piece clamp ring 30 to give a sealed coupling that is similar to a ball joint type of flexible connection. One or more of these victaulic coupling means 16 or similar flexible sealed connecting means may be used on or between the lines or fittings in this system for flexibility and still remain within the scope of this patent. Coupled to the T-section 24 is a crossover line 32 having a similar conventional flange 26 and cover plate 28 . The flexible victaulic coupling means 16 between the 90-degree elbow 22 and the T-section 24 allows flexibility along the X-axis parallel to the frame of the vehicle. The flexible victaulic coupling means 16 between the T-section 24 and the crossover line 32 allows flexibility along the Y-axis perpendicular to the frame of the vehicle. The angled strainer basket housing 34 is shown attached to the right side of the flow reversing two-way valve 18 by the means of a square-mounting flange 36 . The strainer basket housing 34 has a cover plate 38 . The conventional pump 40 is shown at the rear with an inter-connecting line 42 attached to the left side of the reversing two-way valve 18 by the means of a square-mounting flange 36 . A pump mounting bracket 44 is attached to the conventional pump 40 , the flow reversing two-way valve 18 and the frame of the vehicle supporting the assembly. A pump drain valve 46 is shown on the lower right side positioned to drain substantially all fluid from the pump control and distribution system 10 .
[0088] FIG. 2 depicts a perspective view of a variety of different couplings that can be used to adapt the manual bulk-liquid pump control and distribution system 10 into different configurations. The first fitting on the left is the flanged coupling 14 A with the flexible victaulic coupling means 16 . The second fitting is a threaded flanged coupling 14 B. The third is a flanged elbow 22 B, to be used when the crossover line 32 is not desired.
[0089] FIG. 3 depicts a perspective view of the right side of the manual bulk liquid pump control and distribution system 10 illustrating the directional suction flow of the bulk liquid along with the strainer basket 48 partly removed from strainer basket housing 34 . The extended handle 50 mounted on the lip 52 of the strainer basket 48 extends the strainer basket housing 34 forward increasing the accessibility to the cover plate 38 . Note at this point that no matter whether the flow reversing two-way valve 18 is in the discharge or suction mode that the liquid always passes through the strainer basket 48 in the same direction. At the right is a half-round shield 54 for the drive coupling on the power take off.
[0090] FIG. 4 depicts a perspective side view of the manual bulk liquid pump control and distribution system 10 illustrating the inclined angle along the Z-axis of the strainer basket housing 34 eliminating spillage when the cover plate 38 is opened for cleaning of the strainer basket 48 . A unique angled elbow 56 is used to make the connection between the strainer basket housing 34 and the pump 40 positioning the flow reversing two-way valve 18 and valve handle 20 in a convenient location and keeping the system as compact as possible. The elbow 56 may be custom made with a flange and an angle to fit a variety of different brand name pump specifications. In the preferred embodiment as shown, the elbow 56 is angled at 110-degrees, however many other configurations are anticipated depending on the particular pump used. Similarly, the flange on the inter-connecting line 42 is custom designed to fit the particular pump 40 used.
[0091] FIG. 5 depicts a perspective view of the left side of the manual bulk liquid pump control and distribution system 10 illustrating one of the alternate configurations with the intake orifice 12 in the flanged coupling 14 A at the bottom of the flow reversing two way valve 18 . The discharge through the 90-degree elbow 22 is at the top with a pipeline 58 going parallel to the frame to the back of the vehicle.
[0092] FIG. 6 depicts a side elevation schematic of a flow reversing two-way valve 18 with the side cut away illustrating the flow pattern in the discharge configuration.
[0093] FIG. 7 depicts a side elevation schematic of a flow reversing two-way valve 18 with the side cut away illustrating the flow pattern in the suction configuration.
[0094] Valve 18 can also be in a third neutral position between the discharge position and suction position where flow or pressure differential is not developed between the inlet orifice and outlet orifice. In one mode, the liquid recirculates between the valve and pump. Handle 20 (shown in FIG. 1 and FIG. 5 ) is used to change the liquid flow direction in valve 18 . Adjusting handle 20 between the neutral position and either the discharge position or the suction position will change the flow rate of liquid through valve 18 .
[0095] FIG. 8 is an exploded view of another embodiment of a reversing flow control valve 58 . Reversing control valve 58 has valve body 60 , a truncated conical tapered interior and four flanged ports 62 . Each flanged port 62 has a recessed O-ring 64 to provide a leak free coupling across the flange face of the port. Valve body 60 also has a top flange face 66 .
[0096] Valve candle 68 has a flat plate impeller 70 with tapered sides to match the truncated conical taper in valve body 60 . Valve candle 68 has top shaft 72 with a recessed O-ring 74 that interacts with valve bonnet 82 for leak free operation. Aperture 76 is positioned in top shaft 72 to secure a handle. Bottom shaft 78 has a recessed O-ring 80 that interacts with valve body 60 for leak free operation. An indexing pin 81 is mounted on the upper surface of valve candle 68 . The impeller 70 is configured to direct liquid flow in and out two adjacent ports when aligned between ports. Impeller 70 can also align with two opposite ports to allow liquid to recirculate within valve 58 and through the pump.
[0097] Valve bonnet 82 has flange 84 with recessed O ring 86 adapted to couple to top flange face 66 of valve body 60 and has indexing ears 88 that restrict the turning range of valve candle 68 by restricting the travel of indexing pin 81 and providing tactile resistance at the end of the range. In this embodiment, the turning range of valve 58 extends from the discharge position, through the neutral position and to the suction position. In a further embodiment, valve bonnet 82 has visible markings such as “discharge,” “neutral” and “suction” to indicate the position of the valve relative to the position of handle 90 . In a still further embodiment, the markings on valve bonnet 82 are “load on,” “neutral,” and “load off.” Handle 90 is coupled to upper shaft 72 with pin 92 that fits through aperture 76 and indexes the handle position relative to the position of impeller 70 .
[0098] Note that when impeller 70 is positioned in the neutral position in valve body 60 , liquid can flow freely between each port 62 . In this mode, liquid is recycled through the pump and reversing valve 58 but no pressure is developed between the inlet orifice and outlet orifice. Thus there is no flow of liquid into or out of the inlet orifice or outlet orifice of reversing valve 58 .
[0099] FIG. 9 is a cross section view of reversing flow control valve 58 shown in FIG. 8 . Tapered valve candle 68 is seated in the internal chamber of valve body 60 . Spring 92 is positioned under bonnet 82 to urge valve candle 68 into the tapered internal chamber of valve body 60 . Recessed O-ring 74 seats in the center opening of bonnet 82 to prevent leaking when the fluid in valve 58 is under pressure. Similarly, O-ring 80 positioned on bottom shaft 78 seats in valve body 60 to resist leaks under pressure. Jack screw 96 screws into jack nut 98 which is coupled to the bottom of valve body 60 . Jack screw 96 is the lower pivot for bottom shaft 78 and vertical adjustment for optimum positioning of valve candle 68 in the taper of valve body 60 to adjust the tension on handle 90 and prevent binding or leaking.
[0100] FIG. 10 illustrates a side view of another embodiment of a liquid pump control and distribution system 100 with a positive displacement vane pump 102 shown in partial cross section view. Vane pump 102 is shown supported on bracket 44 such as on a vehicle, but could also be skid mounted or permanently mounted near a liquid containment vessel. Pump 102 has inlet 104 fluidly coupled to reversing two-way valve 58 through strainer housing 34 and has outlet 106 fluidly coupled to inter-connecting line 42 . In one embodiment, the fittings of pump control and distribution system 100 are about 3 inch in diameter. In a preferred embodiment, pump 102 is a constant speed pump since flow rate and direction can be controlled by valve 58 . In a further embodiment, pump 102 is operated by engaging a power take off shaft on a vehicle. In one embodiment, pump 102 can transfer up to 240 gallons per minute of liquid.
[0101] Vane Pump 102 has a pressure relief valve 108 that will allow liquid flow from the pump outlet 106 to the pump inlet 104 when the pressure differential exceeds the relief valve setting. In one embodiment, the pressure relief valve is set at about 75 psi. In normal operation using reversing valve 58 , relief valve 108 is only required to mitigate fluid hammer during a loaded pump start or quick valve movements since no pressure is developed between the inlet and outlet orifices when reversing valve 58 is in the neutral position.
[0102] Port 110 is placed in the sump of pump 102 and positioned at the lowest point liquid can flow in the outlet 106 of pump 102 . Preferably, port 110 is positioned at the lowest point liquid can flow in liquid pump control and distribution system 100 . In one embodiment, port 110 is ¼ inch NPT. A drain line 112 is sloped downward from port 110 and terminates in a spring-loaded, normally closed “deadman” purge valve 114 . In a further contemplated embodiment, a removable container is connected to spring-loaded purge valve 114 to collect fluid drained from liquid pump control and distribution system 100 . Purge valve 114 can also be used to pull samples of product being transferred and pressurize the system and test for leaks.
[0103] A drain port 116 is also positioned at the lowest point in strainer body 34 . This port can be fitted with a valve such as a ball valve or spring loaded valve to drain any liquid remaining in strainer body 34 . Since strainer body 34 is coupled to the suction inlet 104 of pump 102 , the pump would need to be disengaged before draining liquid through port 116 .
[0104] After a liquid transfer operation is complete, some liquid is retained in liquid pump control and distribution system 100 . When pump 104 is running, opening spring-loaded purge valve 114 and moving handle 90 to the discharge or suction position will build internal pump pressure and discharge substantially all retained liquid in reversing valve 58 , pump 104 and associated pipe and fittings. When substantially no liquid remains in outlet 106 of pump 104 , the pump will discharge air from purge valve 114 . The discharge of air from purge valve 114 is visible and audible.
[0105] A method of using pump control and distribution system 100 is described as follows: The first port of reversing valve 58 is coupled to inlet 104 of pump 102 and the third port of reversing valve 58 is coupled to outlet 106 of pump 102 . Typically, there are ball or butterfly shut off valves with victaulic or flange fittings installed at the inlet orifice connection and the selected outlet of crossover pipe 32 . The first containment vessel or liquid reservoir is connected to the inlet orifice or second port of reversing valve 58 . The second containment vessel or liquid receiver is connected to the outlet orifice or fourth port through crossover pipe 32 , typically with a hose. Handle 90 of valve 58 is placed in the neutral position. The operator opens the shut off valve to the liquid receiver and starts or engages pump 102 . Next the shut off valve on the crossover pipe to the hose is opened. Handle 90 is then moved slowly to the discharge position until liquid flows from the liquid reservoir through the two way reversing valve 58 and into the liquid receiver. During the liquid transfer, handle 90 can be moved anywhere between the discharge and suction positions. For example, handle 90 can be moved quickly from the discharge position to the suction position if a leak is observed or the hose becomes accidentally disconnected.
[0106] When the transfer of liquid is complete, handle 90 of valve 58 is moved to the neutral position to stop flow of liquid and the shut off valve to the liquid reservoir is closed. Next, the hose is disconnected from the liquid receiver, keeping the open end of the hose elevated above the crossover line to prevent spillage of retained liquid.
[0107] Next, the operator moves handle 90 of reversing valve 58 to the suction position and walks the hose end up towards the connection with crossover pipe 32 until substantially all retained liquid in the hose flows into pump control and distribution system 100 . When this step is completed the valve to the hose is closed, thereby retaining the liquid in reversing valve 58 and pump 104 . The operator moves handle 90 to the neutral position and disengages or turns off pump 104 .
[0108] At this point hoses and vents can be removed and stored, ports capped and the vehicle moved to the next destination to distribute liquid. Alternately, another containment vessel or liquid reservoir on the vehicle can be connected to the pump control and distribution system 100 to transfer liquid to another liquid receiver.
[0109] The first containment vessel on the vehicle can be refilled by connecting a liquid source to the fourth port of reversing valve 58 , opening the internal valves, engaging the pump and moving handle 90 to the second or suction position. Liquid will flow from the liquid source through the fourth port and into the first containment vessel through the second port. Flow of liquid is stopped by moving handle 90 to the neutral position.
[0110] In some situations, it is desired to remove all retained liquids in pump control and distribution system 100 before transferring a different liquid from a different containment vessel. A method to remove substantially all retained liquid from the pump control and distribution system 100 after transferring liquid is as follows: After liquid is transferred and the shut off valves to the liquid receiver, the liquid reservoir and to the hose are closed, position handle 90 to the neutral position and start the pump. Place a container under spring-loaded purge valve 114 . Move handle 90 slowly to the discharge position and open purge valve 114 . Pump 104 will discharge substantially all retained liquid in pump control and distribution system 100 through drain line 112 and out purge valve 114 . Collect purged liquid in the container until only air is discharged from purge valve 114 . Release spring-loaded purge valve 114 , return handle 90 to the neutral position and turn off pump 104 . At this point, there is substantially no liquid retained in the system. The discharge of air from purge valve 114 can be seen and heard and is an observable indicator that there is substantially no liquid retained in pump control and distribution system 100 .
[0111] An additional step to ensure and verify that no liquid remains in pump control and distribution system 100 is to open port 116 in strainer body 34 after pump 102 is off to drain any remaining liquid retained in strainer body 34 .
[0112] If verification is desired that substantially no liquid is retained in the system, a witness can observe that only air is discharged from spring-loaded purge valve 114 and annotate the delivery log. This verification that substantially no liquid is retained can be made at the end of a liquid transfer or prior to filling the liquid reservoir. The observer can also verify that port 116 in strainer body 34 was opened to drain any remaining liquid. Verification that substantially no liquid is retained in the distribution system is particularly important when different liquids are distributed and cross contamination with even a small amount of retained liquid cannot be tolerated.
[0113] Verification of substantially no liquid retained in a liquid reservoir connected to the inlet orifice and positioned above pump control and distribution system 100 can be accomplished just prior to refilling the liquid reservoir as follows: First, close the shut off valve to the outlet orifice. Position handle 90 to the neutral position, start the pump and open the internal valve to the liquid reservoir. Move handle 90 first toward the discharge position to remove any retained liquid from the liquid reservoir, then close the internal valve on the liquid reservoir. Place a container under spring-loaded purge valve 114 and open spring-loaded purge valve 114 and move handle 90 toward the suction position and until only air is discharged. Close purge valve 114 , move handle 90 to the neutral position and turn the pump off. An additional step would be to open port 116 in strainer body 34 and drain any remaining fluid after pump 102 is shut off. Verification that substantially no liquid is retained in the liquid reservoir is particularly important when cross contamination with even a small amount of retained liquid cannot be tolerated.
[0114] FIG. 11 illustrates a side view of further embodiment of a liquid pump control and distribution system 120 with a positive displacement gear pump 122 shown in partial cross section view. Pump 122 is supported on bracket 44 and has inlet 124 fluidly coupled to reversing two-way valve 58 through strainer housing 34 and has outlet 126 fluidly coupled to inter-connecting line 42 . Pump 122 also has a relief valve 128 that will recycle liquid from the pump outlet 126 to the pump inlet 124 when the pump is running and the pressure exceeds the relief valve setting. In one embodiment, pump 122 has about a 3 inch diameter inlet and outlet and can transfer up to about 130 GPM of liquid. In another embodiment, pump 122 has about a 4 inch inlet and outlet and can transfer up to about 300 GPM of liquid. In a preferred embodiment, pump 122 is a constant speed pump since flow rate can be controlled by valve 58 .
[0115] Port 130 is positioned in the sump of pump 122 , which is the lowest point liquid can flow in the outlet 126 of pump 122 . Preferably, port 130 is positioned at the lowest point liquid can flow in liquid pump control and distribution system 120 . A drain line 112 is sloped downward from port 120 and connects a spring-loaded, normally closed “deadman” purge valve 114 .
[0116] A drain port 116 is also positioned at the lowest point in strainer body 34 . This port can be fitted with a drain plug or valve such as a ball valve or spring loaded valve to drain any liquid remaining in strainer body 34 .
[0117] In a less preferred embodiment, a centrifugal pump or a diaphragm pump is configured to operate with reversing flow control valve 58 to transfer liquids.
[0118] FIG. 12 illustrates another embodiment of a manual bulk liquid pump control and distribution system 140 similar to FIG. 1 but where crossover line 32 is positioned inside interconnecting line 42 . This embodiment allows manual bulk liquid pump control and distribution system 140 to be mounted in a compact area, such as under a vehicle. In one mode of this embodiment, the front shaft of pump 40 is shortened or removed so as not to interfere with crossover line 30 .
[0119] In a further embodiment, an additional top crossover line can be coupled to intake orifice 12 . In this configuration, liquid can be pumped from one side of the system and discharged to the other side of the system. This configuration is particularly useful when access to the system is restricted for loading or offloading liquid. An example is where a system is mounted on a vehicle and hoses cannot be placed beneath the vehicle for access or safety reasons. This configuration can also add versatility to a system that needs to change liquid transfer modes quickly such as a fire suppression vehicle.
[0120] Although the description above contains many details, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Therefore, it will be appreciated that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” All structural, chemical, and functional equivalents to the elements of the above-described preferred embodiment that are known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. 112, sixth paragraph, unless the element is expressly recited using the phrase “means for.”
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The present invention is a pump control and distribution system consisting of a pump and reversing flow control valve with a single-handle to control flow direction and flow rate of a liquid. The system can be operated at a rate of 0 to 300 gallons per minute and the flow reversed or stopped with a single motion of the operating handle. The flow rate of the liquid can be precisely controlled in either direction, along with the liquid pressure. This allows the use of a constant speed pump turning in one direction and gives the operator the ability to control the product transfer regardless of viscosity or volume. A purge valve connected to the outlet of the pump is used to remove substantially all retained liquid in the system after transfer of liquid is complete. The system can be mounted to a vehicle for delivery of bulk liquids.
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INTRODUCTION
The present invention is directed to a water saving toilet system controller, and, more particularly, to a controller providing improved control of the timing of the operation of the discharge and flushing stages of the toilet system.
BACKGROUND
In U.S. Pat. No. 4,516,280, dated May 14, 1985, there is shown and described a water saving toilet system. The system herein illustrated is similar in many respects to that shown in the aforesaid patent, but improved in certain aspects, particularly in that it is provided with an improved timing device to control operation of the discharge and flushing stages of the toilet system's operation.
It is an object of the present invention to provide a water saving toilet system which reduces or wholly overcomes some or all of the difficulties inherent in prior known devices. Particular objects and advantages of the invention will be apparent to those skilled in the art, that is, those who are knowledgeable or experienced in this field of technology, in view of the following disclosure of the invention and detailed description of preferred embodiments.
SUMMARY
The principles of the invention may be used to advantage to provide improved control of operation of the discharge and flushing stages of the toilet system.
In accordance with a first aspect, a toilet system controller includes a toilet bowl having at its bottom a discharge opening. A treating chamber has an intake opening connected to the discharge opening of the bowl. A macerator and discharge pump are located in the treating chamber, with the discharge pump discharging treated effluent to a waste pipe. A motor is operably connected to the macerator and discharge pump for effecting simultaneous operation of the macerator and discharge pump. A valve connects the toilet bowl to a source of water in order to admit water to the bowl to flush the bowl. A timer regulates operation of the motor and the valve during a flushing cycle. The flushing cycle is initiated by operation of the motor starting at time zero and continues for five seconds, followed by opening of the valve starting at time zero plus one and one half seconds and continuing for six and one half seconds.
From the foregoing disclosure, it will be readily apparent to those skilled in the art, that is, those who are knowledgeable or experienced in this area of technology, that the present invention provides a significant advance. Preferred embodiments of the toilet system controller of the present invention can provide improved control of the timing sequence of the various stages of the toilet system. These and additional features and advantages of the invention disclosed here will be further understood from the following detailed disclosure of preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments are described in detail below with reference to the appended drawings.
FIG. 1 is a side elevation partly in section of the toilet system of the present invention.
FIG. 2 is a top plan view of the toilet system of FIG. 1 .
FIG. 2A is a fragmentary section of a spray head nozzle of the toilet system FIG. 1 .
FIG. 3 is a plan view, of the treating chamber of the toilet system of FIG. 1, showing a bypass conductor and a conduit connecting the pump to the bypass conductor.
FIG. 4 is an elevation view of the conduit of FIG. 3 .
FIG. 5 is an elevation of the treating chamber of FIG. 1, showing the bypass conductor partly in section.
FIG. 6 is a fragmentary elevation, with a portion in section, of a trap pipe of the toilet system of FIG. 1 connecting the bowl to the treating chamber.
FIG. 7 is a top view of the trap pipe of FIG. 6 .
FIG. 8 is a plan view in section of the pump rotor of the pump of the toilet system of FIG. 1 .
FIG. 9 is a control circuit diagram for controlling the sequence of operation of components of the toilet system of FIG. 1 .
The figures referred to above are not drawn necessarily to scale and should be understood to present a representation of the invention, illustrative of the principles involved. Some features of the toilet system depicted in the drawings have been enlarged or distorted relative to others to facilitate explanation and understanding. The same reference numbers are used in the drawings for similar or identical components and features shown in various alternative embodiments. Toilet systems as disclosed herein, will have configurations and components determined, in part, by the intended application and environment in which they are used.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to the drawings, in FIG. 1 there is shown a toilet bowl 10 supported on a suitable base 12 , to which flush water is supplied by a solenoid-operated valve V and from which effluent is discharged through a trap 14 into a treating chamber 16 where it is macerated by a macerator 16 A and then pumped by means of a pump 18 through a discharge conductor 20 to a soil pipe.
The toilet bowl 10 is of generally conventional configuration, has at the top a cored passage 22 which, as shown in FIG. 2, extends peripherally around the rear half of the bowl, through which flush water is delivered to the bowl for flushing, and a discharge opening 24 at the bottom through which effluent is discharged. The rear end of the cored passage is connected by a feeder tube 26 and suitable plumbing 28 to the valve V which, in turn, is connected to a water supply, not shown, so that operation of the valve will supply flush water to the cored passage. The forward ends of the cored passage terminate diametrically opposite each other approximately halfway between the front and rear ends of the bowl in openings 30 — 30 within which there are fixed spray nozzles 32 — 32 through which water delivered into the cored passage is ejected downwardly on the surface of the bowl. The nozzles 32 — 32 comprise, FIG. 2A, cylindrical plugs 34 containing ports 36 which are in communication with the cored passage 22 and downwardly-open slots 38 designed to eject the flush water downwardly in fan shape against the surface of the bowl so as to wash the surface down.
The trap 14 for conducting the effluent from the bowl to the treating chamber, as shown in FIG. 5, has an upwardly-inclined leg 40 , the lower end of which is flanged at 42 to fit over an extension 44 defining the opening 24 , and a vertical leg 46 connected at its upper end to the inclined leg 40 and at its lower end to the treating tank 16 .
The treating chamber 16 , as seen in FIG. 1, is mounted on the supporting structure for the bowl, behind the bowl, is of generally circular cross section, is closed at the bottom, and has an open top, peripherally of which there is a beveled rim 48 . A cover plate 50 having a beveled edge 52 is mounted on the rim 48 and detachably secured thereto by a locking band 54 , the upper and lower edges 56 and 58 of which overlap the beveled portions of the rim and edge. The locking band 54 provides for easy removal of the cover plate from the treating chamber. The cover plate supports the macerator 16 A, the pump 18 and the drive means therefor. To this end, the cover plate 50 is provided with a top opening 60 in which there is mounted a vertical bearing assembly 62 which supports a shaft 64 in a vertical position with a portion extending above the treating chamber and a portion extending into the treating chamber. The portion of the shaft 64 extending above the treating chamber is fixed by a coupling 66 to the drive shaft 68 of a motor M. The portion of the shaft 64 extending into the treating chamber has fixed to it a macerator blade 70 disposed in a horizontal position at right angles to the axis of the shaft. Below the macerator blade, the bottom of the treating chamber is structured to provide an annular toroidal surface 72 . The blade 70 and the subjacent toroidal surface 72 provide for hydraulic attrition of effluent delivered into the treating chamber. The macerator operates by hydraulic attrition rather than cutting to disperse and particulate the solids in the effluent.
The cover plate 50 is also provided with an opening 74 for receiving the pump assembly 18 and the latter is mounted in the opening by means of a ring 76 fastened by bolts 78 to the top plate and comprises a sealed housing 80 within which there is a stator 82 and a rotor 84 . The upper end of the rotor is fixed to a shaft 86 journaled in a bearing 88 mounted on the ring 78 . The stator and rotor 82 and 84 constitute, in conjunction, a worm pump.
A pulley 90 is fixed to the upper end of the shaft 64 , a pulley 92 is fixed to the upper end of the shaft 86 , and a belt 94 is trained about pulleys 90 , 92 so that the motor M drives the macerator and the pump simultaneously. A control module 95 is mounted at the back of a housing 97 of the toilet system.
The pump 18 has an intake port 96 within treating chamber 16 and a discharge port 98 externally of the treating chamber. Discharge port 98 is connected by a coupling 100 to a length of pipe 101 as seen in FIGS. 3 and 4, which is in turn connected by a coupling 103 to an inlet port 105 on discharge conductor 20 which, as previously mentioned, is connected to a waste pipe. The combination of discharge port 98 , pipe 101 , and inlet port 105 are coaxial such that discharge from pump 18 flows in a straight line to conductor 20 , reducing the chance of blockage as effluent is discharged from pump 18 . Thus, effluent flows from pump 18 in an improved manner through a conduit, free of bends along its length, to conductor 20 , the conduit being formed, in a preferred embodiment, of discharge port 98 , pipe 101 , and inlet port 105 , connected to one another by couplings. This alleviates a problem encountered in prior art systems wherein effluent exiting the discharge pipe encountered a first 90° elbow, flowed downwardly, and then encountered a second 90° elbow before entering the conductor in horizontal fashion. When large amounts of waste and paper were flushed through such a configuration, the discharge force of the pump caused the waste and paper to impact the 90° elbows and lead to plugging of the system. To clear such clogs is a difficult and time consuming process, and includes dismantling a major portion of the system. Consequently, the improved flow of effluent from the pump to conductor 20 of the present invention realizes a significant improvement in the operation and efficiency of the toilet system.
As shown in FIGS. 3 and 5, the discharge conductor 20 is connected at one end directly to the vertical leg of the trap by means of a valve assembly 106 comprising a beveled plate 108 which defines an opening 110 , a plate 112 which defines an opening 114 and a flexible valve member 116 positioned therebetween and clamped in place by a circumferential clamping ring 118 . The plate 108 is fixed to a branch pipe 119 stemming from the leg 46 , the axis of which is inclined upwardly with respect to the vertical axis of the leg 46 so that the plate 108 slopes downwardly at a diverging angle with respect to the axis of the vertical leg. The plate 112 is fixed to the discharge pipe 20 at an angle such as to be parallel to the plate 108 . As thus constructed, the valve assembly slopes downwardly and divergently with respect to the axis of the vertical leg of the trap. The flexible valve member 116 is arranged to open inwardly with respect to the conductor 20 by a pressure head within the vertical leg of the trap and to close by gravity in the absence of a head in the vertical portion of the trap. Normally, when the pump is in operation, it produces a low pressure in the vertical portion of the trap so that the low pressure, in conjunction with the gravitational disposition of the valve member 116 , ensures that the valve will be held closed under normal conditions. An angular disposition of the valve is of importance to prevent siphoning of the effluent from the vertical leg of the trap when the system is at rest. When the system is in use and, for some reason) the pump becomes disabled, a pressure head developed in the vertical leg of the trap will open the valve 116 and allow the effluent to flow directly through the conductor 20 to the waste pipe. The pressure head can be provided by dumping water into the bowl or, if the valve V is operative, supplying water to the bowl through the valve.
In prior toilet systems of this kind, diaphragm and gear pumps have been used for effecting discharge of effluent. However, in accordance with this invention, it has been found that a screw pump is considerably more satisfactory and effective insofar as the flush cycle is concerned. The stator 82 is comprised of flexible rubber and the rotor is plastic. In order to reduce the friction load of the plastic rotor in the flexible rubber stator, a portion of the worm at one end has been reduced to the root diameter of the worm. As herein illustrated, FIG. 8, the rotor 84 , which is comprised of Bakelite, is 4.28 inches axial length. The diameter of the worm is 1.12 inches and has a helix angle of 25 degrees with a lead of 1.648 and at one end a portion a 1.12 inches in length reduced to a uniform diameter of 0.0875 inches. By reducing the portion a at the one end to the root diameter of the worm, the friction between the rotor and stator can be materially reduced, thus reducing the power input necessary to drive the pump.
A flushing cycle of the toilet system in normal operation is sequenced by the control circuitry of control module 95 so that motor M is started first, simultaneously driving macerator 16 A and discharge pump 18 , followed by energization of a solenoid to open the valve V for supplying flush water to the bowl. In a preferred embodiment, the bowl is flushed with approximately 2 and ½ quarts of water during the flushing cycle. While the valve is still open and flushing is still occurring, the discharge pump 18 stops. The flushing operation is subsequently stopped by closing of the valve V. Macerator 16 A is in operation during the entire time that discharge pump 18 is in operation.
FIG. 9 is a wiring diagram showing a timer T which provides for sequencing the operation of the valve V and motor M during the flushing cycle, so as to start the motor before opening the valve and to stop the motor before closing the valve. In the circuit, there is shown a normally open switch SW for energizing the circuit, the motor M for driving the macerator and pump, a solenoid S for activating the valve V, and a timer T powered by a power source P and controlling the sequenced operation of motor M and solenoid actuated valve V. Timer T is preferably sealed in epoxy in module 95 to protect it from moisture, heat, and other environmental conditions.
In a preferred embodiment, the timing of the sequence of the steps during the flushing cycle of the system is as follows. The total operation run time of the flushing cycle is eight seconds, and during that time, timer T of the control circuit performs three separate functions. At the start of the sequence, that is, time zero, the timer first energizes motor M, which then runs for the first five seconds of the cycle and is then deenergized. The timer also provides a delay of one and a half seconds from time zero, at which time the solenoid is opened, opening valve V to provide rinsing of toilet bowl 10 . The timer then provides for the solenoid and valve V to remain open until the end of the eight second run cycle. Such a combination of timing sequences has been found to be particularly advantageous. The particular timing of the components of the toilet system described herein utilizes a minimum of water to efficiently evacuate and rinse the bowl, as well as efficiently treat and discharge the waste from the toilet system. Closing the normally open switch SW during the flushing cycle preferably does not affect operation of the either of the delay cycles, that is, the first delay of 1½ seconds before the solenoid and valve open, or the second delay of 6½ seconds during which the valve remains open and the bowl is flushed.
In a preferred embodiment, timer T is calibrated to an accuracy of ±2%. Motor M preferably is a ¼ HP motor with a 20 amp in-rush, 10 amp run capacity, and in-rush time of approximately 1 second. Solenoid S preferably has a 2 amp in-rush, a 0.45 amp run capacity, and an in-rush time of approximately 0.2 seconds. The supply voltage from power source P to timer T is preferably unfiltered 115 V.A.C. at 60 Hz, with a voltage variation of ±10%, with transients not to exceed 400 volts for 1 milli-second.
It is to be appreciated that although timer T is shown here in conjunction with a specific configuration of a water saving toilet, other constructions of toilets appropriate for the use of such a timer having the performance characteristics described herein are considered within the scope of the invention.
In a preferred embodiment, the power to motor M is supplied initially to the starting circuit of the motor, preferably for approximately 400-600 milliseconds, more preferably approximately 500 milliseconds, and then the power is switched to the running circuit of motor M for the remainder of the five second period during which motor M runs. By switching power from the starting circuit to the running circuit in this manner, the expense of a separate starting switch in the motor is eliminated.
In light of the foregoing disclosure of the invention and description of the preferred embodiments, those skilled in this area of technology will readily understand that various modifications and adaptations can be made without departing from the scope and spirit of the invention. All such modifications and adaptations are intended to be covered by the following claims.
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A toilet system controller including a toilet bowl having at the bottom a discharge opening. A treating chamber has an intake opening connected to the discharge opening of the bowl. A macerator and discharge pump are located in the treating chamber, with the discharge pump discharging treated effluent to a waste pipe. A motor is operably connected to the macerator and discharge pump for effecting simultaneous operation of the macerator and discharge pump. A valve connects the toilet bowl to a source of water in order to admit water to the bowl to flush the bowl. A timer regulates operation of the motor and the valve during a flushing cycle. The flushing cycle is initiated by operation of the motor starting at time zero and continues for five seconds, followed by opening of the valve starting at time zero plus one and one half seconds and continuing for six and one half seconds.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a shift control system for an automatic transmission.
2. Description of the Prior Art
In an automatic transmission, rotation is transmitted to the transmission via a torque converter from an engine, is changed in speed, and then is transmitted to driving wheels. The transmission comprises a gear unit having a plurality of gear elements with frictional engaging elements such as clutches and brakes which are selectively engaged and disengaged to select the speed change (i.e., first gear, second gear, third gear, fourth gear, reverse, etc., hereinafter called gear states) of the transmission.
To prevent shift shock, burning of the friction engaging elements and the like while shifting from one gear state to another, the engaging and disengaging forces of the corresponding frictional elements are controlled. A start input rotational speed is detected. A target shift period for the period from start of the shift operation to end of the shift operation is set. Target input rotational speeds for the shift operation are set. Then the actual input rotational speed is monitored, such as by counting the number of revolutions per unit time of an input shaft, and the operating forces on the corresponding engaging and disengaging frictional elements are controlled during the shift operation to cause the input rotational speed to follow the target input rotational speeds.
The target input rotational speeds of a prior art automatic transmission are illustrated in a time chart of FIG. 2 wherein line N IS represents the target input rotational speeds during a period of vehicle acceleration in which the transmission shifts from one gear state to a higher gear state. The target input rotational speed N IS increases in accordance with depression of an accelerator pedal (not shown) until the shift starts at time t A whereupon the target input rotational speed decreases until time t S when the shift ends. After time t s the target input rotational speed resumes its increase as demanded by the depressed position of the accelerator pedal.
In FIG. 3, a feedback control in the prior art shift control system applies a target rate of change ΔN IS , based upon the target input rotational speed N IS , to one input of a subtracter 61 as a command value while an actual rate of change ΔN IF calculated from readings of the monitored input rotational speed is applied to a second input to the subtracter 61 to implement a feedback control. Any difference between the target rate of change ΔN IS and the actual rate of change ΔN IF is applied to a control element 62 where the difference is multiplied by a control gain such as an integral gain KP to produce a hydraulic pressure set value P.
During the shift of the prior art transmission, the target rate of change ΔN IS is constant and the target input rotational speed N IS is decreased gradually like a straight line, that is, a linear function as shown in FIG. 2. The rate of change ΔN IS of the target input rotational speed N IS has a positive value before the start of the shift and changes abruptly to a negative value at the start of the shift; that is, the rate of change ΔN IS of the target input rotational speed N IS is inverted from positive to negative at the time t A that the shift is started. Further, the rate of change ΔN IS of the target input rotational speed N IS has a negative value before the end of the shift and changes abruptly to a positive value at the end of the shift; that is, the rate of change ΔN IS of the target input rotational speed N IS is inverted from negative to positive at the time t S when the shift is ended.
Similarly during shift from a higher gear state to a lower gear state while a vehicle is decelerating, the rate of change of the prior art target input rotational speed changes abruptly from a negative value to a positive value at the start of the shift and changes abruptly from a positive value to a negative value at the end of the shift.
However, the shift control system of the prior art automatic transmission has had a problem in that the operation of the control system degrades as the frictional engaging elements and other elements in the hydraulic circuit become worn with the lapse of time, causing a change in the actual shift period and thus generating an error between the actual shift period and the target shift period.
Although it is conceivable to overcome an increase in the actual shift period by increasing the control gain of the control element 62 described above, such increase in gain tends to cause deviation of the actual input rotational speed from the target input rotational speed N IS . Because the rate of change ΔN IS of the target input rotational speed N IS is inverted from positive/negative to negative/positive when the shift is started and from negative/positive to positive/negative when the shift is ended, vibration, shift shock or the like are produced in prior art transmissions where the operation of the shift control has degraded.
Accordingly, it is an object of the present invention to solve the aforementioned problem of the prior art shift control system of the automatic transmission by providing a shift control system of an automatic transmission which is capable of preventing such vibration, shift shock or the like from occurring by bringing the actual shift period closer to the target shift period.
SUMMARY OF THE INVENTION
In order to achieve the aforementioned object, a shift control system of an automatic transmission in accordance with the invention generates a target transmission variable corresponding to a target input rotational speed which avoids inverting a rate of change of the corresponding target input rotational speed from positive/negative to negative/positive at least at the start of the shift operation or at the end of the shift operation. The shift control system comprises a transmission equipped with a gear unit having a plurality of gear elements with frictional engaging elements operating the gear elements in a plurality of gear states defining different fixed ratios between transmission input and output rotational speeds; an input shaft for transmitting rotational power from an engine to the transmission; an output shaft for outputting rotational power from the transmission to driving wheels; hydraulic servos for selectively engaging and disengaging the frictional engaging elements to shift gear states to change from one of the fixed ratios between input and output rotational speeds to another of the fixed ratios; a hydraulic pressure generator for generating control hydraulic pressures supplied to the hydraulic servos in accordance to control hydraulic patterns; and a control unit having an actual transmission variable detecting means for detecting an actual transmission variable which corresponds to actual transmission input rotational speed; target transmission variable generating means for generating the target transmission variable; feedback control means for implementing feedback control based on the target transmission variable and the actual transmission variable to output a control value; and shift logic setting means for generating the control hydraulic pattern based on the control value. Because the target transmission variable changes in a manner preventing the rate of change of the corresponding target input rotational speed from inverting from positive/negative to negative/positive at least either when the shift is started or when it is ended, the tendency of prior art transmissions to produce shock, vibration or the like is decreased.
According to a second aspect of the inventive shift control system of the automatic transmission, the target transmission variable generating means changes the target transmission variable without inverting the rate of change of the corresponding target input rotational speed from positive/negative to negative/positive for a first predetermined duration after the shift starts and for a second predetermined duration before the shift ends and changes the target transmission variable by inverting the rate of change by an even number of times during the shift.
According to a third aspect of the inventive shift control system of the automatic transmission, the number of times of the inversion from positive/negative to negative/positive of the rate of change of the corresponding target input rotational speed is two times.
According to a fourth aspect of the inventive shift control system of the automatic transmission, the control unit comprises current control means, the shift logic setting means outputs the control hydraulic signal based on a corrected control hydraulic pattern to the current control means and the current control means outputs a current command signal to the hydraulic pressure generating means corresponding to the control hydraulic signal.
According to a fifth aspect of the inventive shift control system of the automatic transmission, the target transmission variable generating means gradually changes the target transmission variable.
According to a sixth aspect of the inventive shift control system of the automatic transmission, the hydraulic pressure generating means is a linear solenoid.
According to a seventh aspect of the inventive shift control system of the automatic transmission, the transmission has an input rotational speed sensor for detecting a number of revolutions per unit time of the input shaft and an output rotational speed sensor for detecting a number of revolutions per unit time of the output shaft, and the actual transmission variable detecting means calculates an actual gear ratio based on signals from the input rotational speed sensor and the output rotational speed sensor.
Because the target transmission variable changes without inverting the rate of change of the corresponding target input rotational speed from positive/negative to negative/positive at least either at the start of the shift or the end of the shift, the target transmission variable may be changed so that the corresponding target input rotational speed is gradually reduced at the start of the shift and is gradually increased at the end of the shift.
Accordingly, the actual transmission variable may be brought closer to the target transmission variable at least when the shift is started or it is ended even if the control gain is increased in the feedback control means, so that vibration, shift shock or the like may be prevented from occurring at least either when the shift is started or it is ended. Also the actual shift period may be brought closer to the target shift period.
The above and other advantages of the present invention will become more apparent in the following description and the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a conceptual diagram showing a shift control system of an automatic transmission according to a first embodiment of the present invention;
FIG. 2 is a time chart showing changes of an input rotational speed of a prior art shift control system of a automatic transmission;
FIG. 3 is a diagram showing feedback control means in the prior art shift control system of the automatic transmission;
FIG. 4 is a time chart showing changes of an input rotational speed according to the first embodiment of the present invention;
FIG. 5 is a diagram showing feedback control means according to a second embodiment of the present invention; and
FIG. 6 is a flow chart showing an operation of the shift control system according to the first embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will be explained in detail below with reference to the drawings.
As shown in FIG. 1, rotation generated by an engine 10 is transmitted by an engine output shaft 11 to a torque converter 12 which provides a fluid coupling for transferring the input rotation. The rotation transferred by the torque converter 12 is then transmitted by an input shaft 14 to a transmission 16 which changes the rotational speed by increasing or decreasing the rotational speed. The rotation is transmitted from the transmission 16 by an output shaft 17 to a differential gear 18 which may further change the rotational speed and transmit the rotation to driving wheels (not shown).
The transmission 16 comprises a gear unit formed from a plurality of gear elements (only 16a, 16b shown) such as planetary gears and a plurality of frictional engaging elements (only B1, B2 shown) such as clutches and brakes to determine the transmission input to output rotation speed ratio. The frictional engaging elements are selectively engaged and disengaged with the gear elements to select one of a plurality of fixed input to output gear ratios such as first, second, third, fourth, reverse, etc. In the illustrated embodiment of FIG. 1, the transmission 16 has a hydraulic servo C-1 for engaging and/or disengaging the first frictional element B1 and a hydraulic servo C-2 for engaging and/or disengaging the second frictional element B2. For example when hydraulic pressure is supplied to the hydraulic servo C-1 and hydraulic pressure is drained from the hydraulic servo C-2, the first and second clutches or brakes are operated to select one of the fixed input to output transmission gear ratios, and when the hydraulic pressure is drained from the hydraulic servo C-1 and the hydraulic pressure is supplied to the hydraulic servo C-2, the first and second clutches or brakes are operated differently to select another of the fixed input to output transmission gear ratios.
It is noted that the hydraulic servos C-1 and C-2 are disposed in a hydraulic circuit (not shown) for attaining a number of speed ratios. Beside the hydraulic servos such as the hydraulic servo C-1 and hydraulic servo C-2 described above, the hydraulic circuit has a primary regulator valve (not shown) for generating a line pressure, a manual valve (not shown) for generating each range pressure corresponding to a selected range, a plurality of shift solenoid valves (not shown)turned On/Off corresponding to each speed, a 1-2 shift valve (not shown), 2-3 shift valve (not shown) and 3-4 shift valve (not shown) switched corresponding to On/Off of each solenoid valve and a linear solenoid valve 21.
The linear solenoid valve 21 provides a hydraulic pressure (hereinafter referred to as "control hydraulic pressure") which is proportional to a value of a control current to control the engaging force of the first and second clutches, independently. While the transmission gear ratio is being changed by increasing hydraulic pressure to the second clutch and releasing hydraulic pressure to the first clutch, a control hydraulic pressure Pc1 is supplied by the linear solenoid valve 21 to the hydraulic servo C-1 of the first clutch and a control hydraulic pressure Pc2 is supplied to the hydraulic servo C-2 of the second clutch by the linear solenoid valve 21. During this gear shift operation, the control hydraulic pressure Pc1 supplied to the hydraulic servo C-1 is gradually reduced and the control hydraulic pressure Pc2 supplied to the hydraulic servo C-2 is gradually increased.
A control unit 22 provides the control signals for operating the hydraulic servos of the transmission 16. An input rotational speed sensor 31 and an output rotational speed sensor 32 provide inputs of the transmission input rotational speed (for example the number of revolutions of the input shaft 14 per unit time) and the transmission output rotational speed (for example the number of revolutions of the output shaft 17 per unit time) to the control unit. The control unit 22 comprises actual transmission variable detecting means 33, target transmission variable generating means 34, feedback control means 35, shift logic setting means 36 and current control means 37.
The control unit 22 determines a need for a gear shift operation based on traveling conditions such as the present car speed, a throttle opening angle and the like and generates a shift output. Then, a solenoid signal corresponding to the shift output is sent to each shift solenoid of the hydraulic circuit to turn on/off the shift solenoid valve and to supply the control hydraulic pressures Pc1 and Pc2 to the hydraulic servo C-1 and hydraulic servo C-2.
The input rotational speed sensor 31 detects an actual input rotational speed such as segments of angular rotation or a number of revolutions N IF per unit time of the input shaft 14 on the input side of the transmission 16 and the output rotational speed sensor 32 detects an actual output rotational speed such as segments of angular rotation or a number of revolutions N OF per unit time of the output shaft 17 on the output side of the transmission 16. It is noted that alternatively the actual transmission input rotational speed N IF can be determined from the rotational speed of another rotary member in the power transmission system between the input shaft 14 and the output shaft 17 and whose rotational speed changes when a shift is performed, and the actual transmission output rotational speed N OF can be determined from the rotational speed of still another rotary member whose rotational speed does not change due to a shift being performed.
The actual transmission variable detecting means 33 calculates an actual transmission input to output rotational speed ratio or transmission input to output gear ratio (hereinafter referred to as "actual gear ratio") r IF :
r.sub.IF =N.sub.IF /N.sub.OF
as an actual transmission variable based on the actual input rotational speed N IF and the actual output rotational speed N OF . The actual gear ratio r IF is calculated every sampling time during the shift operation from the start of the shift to the end of the shift. Then, the calculated actual gear ratio r IF is output to the feedback control means 35.
The actual input rotational speed N IF and the actual output side rotational speed N OF change differently during the shift operation. When a shift is made from one gear to a higher gear (i.e. an up shift) while accelerating a vehicle, the actual input rotational speed N IF drops and the actual output side rotational speed N OF increases with a constant inclination due to constant accelerating force and inertia of the vehicle. Accordingly, the actual gear ratio r IF becomes smaller as the actual input rotational speed N IF drops and becomes a constant value after the end of the shift.
The target transmission variable generating means 34 generates the target gear ratio r IT as the target transmission variable which corresponds to the target transmission input speed. The target gear ratio r IT is set so as to be able to prevent vibration, shift shock or the like from occurring at the time when the shift is started and when it is ended. For example, the target gear ratio r IT is set so that the target input rotational speed N IT during the shift operation forms a 200° or greater section of a sinusoidal wave as shown in FIG. 4. For an up shift as illustrated in FIG. 4, this 200° sinusoidal wave section between t A and t s extends from about 80° to 280° of a sine wave (from about -10° to 190° of a cosine wave). For a down shift, the 200° sinusoidal wave section of FIG. 4 is inverted or set to correspond to a sine wave section from about -100° to 100° (cosine wave section from about -190° to 10°).
Although the target input rotational speed N IT changes to a lower speed during the shift operation, the target input rotational speed continues to increase but at a decreasing rate for a predetermined duration (for example 10° or more at the start of the sinusoidal wave section of FIG. 4) after time t A at the start of the shift. The positive rate of change of the target input rotational speed N IT during this predetermined duration gradually decreases. Accordingly, the positive rate of change of the target input rotational speed N IT before the start of the shift continues as a positive value after the start of the shift and is not changed from a positive value to a negative value during the predetermined duration after the start t A of the shift.
After the predetermined duration after the start of the shift operation, the rate of the change of the target input rotational speed N IT changes from a positive value to a negative value and subsequently from the negative value back to a positive value, i.e, is inverted twice. The change from the negative value back to the positive value occurs a predetermined duration (for example 10° or more at the end of the sinusoidal wave section of FIG. 4) before the end t S of the shift operation. While the rate of change of the target input rotational speed is negative during the shift operation the input rotational speed N IT decreases. Then before the predetermined duration before the end t S of the shift operation, the input rotational speed begins to increase. The target input rotational speed N IT is increasing at time t S when the shift ends, and the rate of change of the target input rotational speed N IT is gradually increased during the predetermined duration before the end of the shift operation. Accordingly, the rate of change of the target input rotational speed N IT before the end of the shift and that after the shift both take positive values and is not inverted at the time t s when the shift ends.
It is noted that because the actual transmission variable detecting means 33 calculates the actual gear ratio r IF as the actual transmission variable, the target transmission variable generating means 34 calculates and generates the target gear ratio r IT as the target revolution variable based on the target input rotational speed N IT .
The feedback control means 35 performs the feedback control by having the target gear ratio r IT as a command value and the actual gear ratio r IF as an input and outputs a control value P to the shift logic setting means 36. According to the present embodiment, the feedback control means 35 comprises a subtracter 51 and a control element 52. The target gear ratio r IT is sent as the command value and the target gear ratio r IF is sent as the input, respectively, to the subtracter 51 and a deviation Δr obtained by subtracting the actual gear ratio r IF from the target gear ratio r IT is input to the control element 52. The control element 52 then multiplies the inputted deviation Δr with a control gain such as proportion gain and stored gain and outputs a control value P.
The shift logic setting means 36 generates set patterns (hereinafter referred to as "control hydraulic patterns") of the control hydraulic pressures Pc1 and Pc2 described above, corrects the patterns in accordance to the control value P and outputs the corrected control hydraulic pattern to the current control means 37 as a control hydraulic signal SG1. Receiving the control hydraulic signal SG1, the current control means 37 outputs a current command value I 1 for the hydraulic servo C-1 and a current command value I 2 for the hydraulic servo C-2 to the linear solenoid valve 21.
As described above, the rate of change of the target input rotational speed N IT is suppressed from changing significantly at the time when the shift is started and when it is ended, so that the actual input rotational speed N IF will not be separated from the target input rotational speed N IT even if the control gain is increased. Accordingly, vibration, shift shock or the like may be prevented from occurring.
Further, because the control gain can be increased, it becomes possible to bring the actual shift period closer to the target shift period.
The operation of the shift control system of the automatic transmission constructed as described above will be explained below in a form of a flow chart in FIG. 6.
Step S1: Increment the sampling time t. For example, the sampling time t is incremented every 10 milliseconds in the present embodiment;
Step S2: Detect an actual transmission variable by detecting a target input rotational speed N IF and an actual output side rotational speed N OF and by calculating an actual gear ratio r IF ;
Step S3: Determine whether or not the transmission 16 (in FIG. 1) is at the start of a shift operation at the present sampling time t. Advance to Step S4 when the present sampling time is the start of a shift operation. When the present sampling time t is not the start of the a shift operation, advance to Step S5;
Step S4: Calculate the target gear ratios r IT from t=0 to t=T: ##EQU1## where r 1 is the gear ratio when the shift is started, r 2 is the gear ratio to which the transmission is to be shifted, and T is the target shift period.
Step S5: Determine whether or not the transmission 16 is performing a shift operation at the current sampling time t. Advance to Step S6 when currently performing a shift operation and if not, return;
Step S6: Set an actual gear ratio r IF from Step S2. Set a target gear ratio r IT read from Step S4.
Step S7: Perform feedback control by the feedback control means 35 to generate a control value P;
Step S8: Correct a control hydraulic pattern based on the control value P.
It is noted that although the actual transmission variable detecting means 33 calculates the actual gear ratio r IF as the actual transmission variable and the target transmission variable generating means 34 generates the target gear ratio r IT as the target transmission variable in the present embodiment, alternatively the actual transmission variable detecting means 33 detects the actual input rotational speed N IF as the actual transmission variable and the target transmission variable generating means 34 generates the target input rotational speed N IT as the target transmission variable.
FIG. 5 is a diagram showing feedback control means according to the above alternative as a second embodiment of the present invention. In this case, the feedback control means 35 comprises the subtracter 51 and the control element 52, the target input rotational speed N IT is sent as a command value and the actual input rotational speed N IF is sent as an input, respectively, to the subtracter 51 and a deviation ΔN obtained by subtracting the actual input rotational speed N IF from the target input rotational speed N IT is input to the control element 52. The control element 52 then multiplies the inputted deviation ΔN with a control gain such as proportion gain and storage gain and outputs a control value P.
Then, the target transmission variable generating means 34 (FIG. 1) calculates the target input rotational speed N IT : ##EQU2## where ΔN IF0 is the increase/decrease or rate of change of the number of input revolutions per sample time (i.e. transmission input rotation acceleration/deceleration) at the start of the shift operation. This rotation acceleration/deceleration ΔN IF0 changes the curve segment representing N IT between the start and the end of the shift operation so that the curve segment approximates a sine wave segment of 200° or more and the rate of change of the target input rotational speed N IT does not invert at the start and the end of the shift operation.
When the feedback control is implemented so that the actual input rotational speed N IF becomes the target input rotational speed N IT in the feedback control means 35 by detecting the actual input rotational speed N IF as the actual transmission variable, it becomes possible to implement feedback control which corresponds to respective deviation ΔN in a high rotational speed range where the deviation ΔN of the actual input rotational speed N IF becomes large and in a low rotational speed range where the deviation ΔN of the actual input rotational speed N IF becomes small. Accordingly, the follow up of the feedback control means 35 may be improved.
It is noted that the target transmission variable can be changed in accordance with many different curve segments other than sinusoidal curve segments during the shift operation from t A to t S to prevent the rate of change of the corresponding target input rotational speed from inverting simultaneously with the start or the end of the shift. For example, the target transmission variable can be changed so that the corresponding target input rotational speed is represented by any curve segment having a general zig-zag configuration between t A and t S with beginning and end portions of the zig-zag segment having positive/negative rates of change which are of the same sign (positive/negative) as the rate of change before t A and after t S .
While preferred embodiments have been described, it is to be understood that the present invention is not confined to the embodiments described above and that various changes and modifications may be made based on the spirit of the present invention. It is therefore intended to cover in the appended claims all such changes and modifications.
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A shift control system of an automatic transmission controls operating forces on frictional engaging elements being engaged and disengaged with gear elements during a shift operation by generating a target transmission variable which prevents a rate of change of a corresponding target input rotational speed from inverting at the start of the shift operation and/or at the end of the shift operation. The target transmission variable may be the target input rotational speed, a target gear ratio, or other variable corresponding to a target input rotational speed which has a rate of change gradually changing at the start and end of the shift operation so as to avoid any inversion of the rate of change within a predetermined duration after the start of the shift operation and within a predetermined duration before the end of the shift operation. The target transmission variable is applied along with a detected actual transmission variable to a feedback control which produces a signal for correcting a control hydraulic pattern produced in shift logic to operate a current control which controls a linear solenoid valve operating hydraulic servos to control the frictional engaging elements.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a DIV of Ser. No. 11/068,880 (filed Mar. 2, 2005, now U.S. Pat. No. 7,112,291), which application is a DIV of Ser. No. 10/210,178 (filed Aug. 2, 2002, now U.S. Pat. No. 6,998,071), which in turn claims priority of Japanese application Serial Nos. 2001-236891 filed Aug. 3, 2001 and 2002-156223 filed May 29, 2002, the disclosures of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
The present invention relates to cobalt oxide particles, a process for producing the cobalt oxide particles, a cathode active material for a non-aqueous electrolyte secondary cell, a process for producing the cathode active material, and a non-aqueous electrolyte secondary cell. More particularly, the present invention relates to cobalt oxide particles useful as a precursor of a cathode active material for a non-aqueous electrolyte secondary cell which is capable of showing a stable crystal structure by insertion reaction therein, and producing a non-aqueous electrolyte secondary cell having a high safety and especially a high heat stability, a process for producing the cobalt oxide particles, a cathode active material for a non-aqueous electrolyte secondary cell using the cobalt oxide particles, a process for producing the cathode active material, and a non-aqueous electrolyte secondary cell using the cathode active material.
With the recent rapid development of portable and cordless electronic devices such as audio-visual (AV) devices and personal computers, there has been an increasingly demand for providing as a power source thereof, a secondary cell (lithium battery) having a small size, a light weight and a high energy density. Under this circumstance, lithium ion secondary cells have been especially noticed because of advantages such as high charge/discharge voltage as well as large charge/discharge capacity.
Hitherto, as cathode active materials useful for high energy-type lithium ion secondary cells having a 4V-grade voltage, there are generally known LiMn 2 O 4 which has a spinel structure, LiMnO 2 which has a corrugated layer structure, LiCoO 2 , LiCo 1−x Ni x O 2 and LiNiO 2 which have a rock-salt layer structure, or the like. Among the secondary cells using these active materials, lithium ion secondary cells using LiCoO 2 are more excellent because of high charge/discharge voltage and large charge/discharge capacity thereof. These lithium ion secondary cells have been required to show more excellent properties.
Specifically, when lithium ions are released from LiCoO 2 , the crystal structure of LiCoO 2 undergoes Jahn-Teller distortion since Co 3+ is converted into Co 4+ . When the amount of lithium ions released reaches 0.45, the crystal structure of LiCoO 2 is transformed from hexagonal system into monoclinic system, and a further release of lithium ions causes the transformation of the crystal structure from monoclinic system into hexagonal system. Therefore, by repeating the charge/discharge reaction, the crystal structure of LiCoO 2 tends to become unstable, resulting in release of oxygen from LiCoO 2 and undesired reaction between LiCoO 2 and an electrolyte solution.
Further, the reaction between LiCoO 2 and the electrolyte solution is more active under higher temperature conditions. Therefore, in order to ensure safety of the secondary cell, it has been required to provide cathode active materials exhibiting a stable structure, namely a high heat stability even under high temperature conditions.
For these reasons, it has been required to provide lithium cobaltate (LiCoO 2 ) exhibiting a stable crystal structure even when lithium is released therefrom.
Hitherto, in order to stabilize a crystal structure of lithium cobaltate and improve various properties thereof such as charge/discharge cycle characteristics, there are known a method of incorporating magnesium into lithium cobaltate particles (Japanese Patent No. 2797693 and Japanese Patent Application Laid-Open (KOKAI) Nos. 5-54889(1993), 6-168722(1994), 7-226201(1995), 11-102704(1999), 2000-12022, 2000-11993 and 2000-123834); a method of mixing magnesium with lithium cobaltate particles by a hydrothermal synthesis method (Japanese Patent Application Laid-Open (KOKAI) No. 10-1316(1998)); a method of controlling a lattice constant of lithium cobaltate to improve properties thereof (Japanese Patent Application Laid-Open (KOKAI) No. 6-181062(1994)); or the like.
In addition, in order to obtain lithium cobaltate particles satisfying the above properties, cobalt oxide particles as a precursor thereof are also required to show an excellent reactivity. As the method for producing cobalt oxide particles having an excellent reactivity, there has been proposed a method of obtaining fine cobalt oxide particles by a wet reaction method (Japanese Patent Application Laid-Open (KOKAI) Nos. 10-324523(1998) and 2002-68750).
At present, it has been strongly required to provide cathode active materials satisfying the above requirements and cobalt oxide particles as a precursor thereof. However, such cathode active materials and cobalt oxide particles have not been obtained until now.
That is, in Japanese Patent No. 2797693 and Japanese Patent Application Laid-Open (KOKAI) Nos. 5-54889(1993), 6-168722(1994), 7-226201(1995), 11-102704(1999), 2000-12022, 2000-11993 and 2000-123834, there is described the method of obtaining lithium cobaltate particles containing magnesium by dry-mixing a cobalt compound, a lithium compound and a magnesium compound. However, in this method, since the obtained lithium cobaltate particles show a non-uniform distribution of magnesium within the particle, the crystal structure thereof tends to undergo destruction upon the release and insertion reactions of lithium ions. As a result, the lithium cobaltate particles fail to show an excellent heat stability.
In Japanese Patent Application Laid-Open (KOKAI) No. 10-1316(1998), there is described the method for producing lithium cobaltate particles by dispersing a cobalt compound and a magnesium compound in an aqueous lithium hydroxide solution and heat-treating the resultant dispersion. However, this method requires to conduct the hydrothermal treatment, and the obtained lithium cobaltate particles fail to show a small particle size and excellent particle properties.
Also, in Japanese Patent Application Laid-Open (KOKAI) No. 6-181062(1994), there is described lithium cobaltate having a c-axis length of lattice constant of not less than 14.05 Å. However, the obtained lithium cobaltate cannot be sufficiently improved in heat stability as compared to those containing magnesium and, therefore, fails to show an excellent heat stability.
Further, in Japanese Patent Application Laid-Open (KOKAI) Nos. 10-324523(1998) and 2002-68750, there is described the method for producing fine cobalt oxide particles by a wet reaction method. However, since no magnesium is contained in the obtained cobalt oxide particles, a cathode active material composed of lithium cobaltate particles produced from such cobalt oxide particles fails to show a sufficient heat stability.
As a result of the present inventors' earnest studies for solving the above problems, it has been found that by mixing a lithium compound with cobalt oxide particles containing magnesium therein which have a composition represented by the formula: (Co (1−x) Mg x ) 3 O 4 (0.001≦x<0.15), and have a BET specific surface area value of 0.5 to 50 m 2 /g and an average particle diameter of not more than 0.2 μm, or cobalt oxide particles surface-coated wit magnesium hydroxide which have a composition represented by the formula: (1−x)Co 3 O 4 .3xMg(OH) 2 (0.001≦x<0.15), and have a BET specific surface area value of 0.5 to 50 m 2 /g and an average particle diameter of not more than 0.2 μm; and heat-treating the resultant mixture, the obtained cathode active material has not only a more stable crystal structure but also a more excellent heat stability, and is useful as a cathode active material for a non-aqueous electrolyte secondary cell. The present invention has been attained based on the above finding.
SUMMARY OF THE INVENTION
An object of the present invention is to provide cobalt oxide particles useful as a precursor of a cathode active material having not only a more stable crystal structure but also a more excellent heat stability, and a process for producing the cobalt oxide particles.
Another object of the present invention is to provide a cathode active material for a non-aqueous electrolyte secondary cell which has not only a more stable crystal structure but also a more excellent heat stability, and a process for producing the cathode active material.
A further object of the present invention is to provide a non-aqueous secondary cell not only maintaining an excellent initial discharge capacity required for secondary cells, but also having an improved heat stability.
In order to accomplish the aims, in a first aspect of the present invention, there are provided cobalt oxide particles having a composition represented by the formula:
(Co (1−x) Mg x ) 3 O 4
wherein x is 0.001 to 0.15, and
having a BET specific surface area value of 0.5 to 50 m 2 /g and an average particle diameter of not more than 0.2 μm.
In a second aspect of the present invention, there are provided cobalt oxide particles surface-coated with magnesium hydroxide, having a composition represented by the formula:
(1−x) CO 3 O 4 ·3xMg(OH) 2
wherein x is 0.001 to 0.15, and
having a BET specific surface area value of 0.5 to 50 m 2 /g and an average particle diameter of not more than 0.2 μm.
In a third aspect of the present invention, there are provided cobalt oxide particles having a composition represented by the formula:
(Co (1−x) Mg x ) 3 O 4 ·3yAl(OH) 3
wherein x is 0.001 to 0.15 and y is 0.001 to 0.05, and
having a BET specific surface area value of 0.5 to 50 m 2 /g and an average particle diameter of not more than 0.2 μm.
In a fourth aspect of the present invention, there is provided a cathode active material for a non-aqueous electrolyte secondary cell, having a composition represented by the formula:
LiCo (1−x) Mg x O 2
wherein x is 0.001 to 0.15,
having an average particle diameter of 1.0 to 20 μm, and
having an a-axis length of lattice constant of from 0.090x+2.816 Å to 0.096x+2.821 Å and a c-axis length of lattice constant of 0.460x+14.053 Å to 0.476x+14.063 Å wherein x has the same meaning as defined above.
In a fifth aspect of the present invention, there is provided a cathode active material for a non-aqueous electrolyte secondary cell, having a composition represented by the formula:
Li (Co (1−x−y) Mg x Al y )O 2 ,
wherein x is 0.001 to 0.15 and y is 0.001 to 0.05
having an average particle diameter of 1.0 to 20 μm, and
having an a-axis length of lattice constant of from 0.090x+2.816 Å to 0.096x+2.821 Å and a c-axis length of lattice constant of 0.460x+14.053 Å to 0.476x+14.063 Å wherein x has the same meaning as defined above.
In a sixth aspect of the present invention, there is provided a cathode active material for a non-aqueous electrolyte secondary cell, having a composition represented by the formula:
LiCo (1−x) Mg x O 2
wherein x is 0.001 to 0.15,
having an average particle diameter of 1.0 to 20μm, a BET specific surface area value of 0.1 to 1.6 m 2 /g, a volume resistivity value of 1.0×10 to 1.0×10 6 Ω·cm, an electron conductivity (log (1/Ωcm) of −0.5 to −5.0 and a crystallite size of 400 to 1,200 Å, and
having an a-axis length of lattice constant of from 0.090x+2.816 Å to 0.096x+2.821 Å and a c-axis length of lattice constant of 0.460x+14.053 Å to 0.476x+14.063 Å wherein x has the same meaning as defined above.
In a seventh aspect of the present invention, there is provided a non-aqueous electrolyte secondary cell having a cathode comprising the cathode active material defined in the third aspect or fourth aspect.
In an eighth aspect of the present invention, there is provided a process for producing the cobalt oxide particles defined in the first aspect, comprising:
neutralizing a solution containing a cobalt salt and a magnesium salt with an aqueous alkali solution; and
then subjecting the resultant mixture to oxidation reaction to obtain magnesium-containing cobalt oxide particles.
In a ninth aspect of the present invention, there is provided a process for producing the cobalt oxide particles defined in the second aspect, comprising:
neutralizing a solution containing a cobalt salt with an aqueous alkali solution;
subjecting the resultant mixture to oxidation reaction to obtain a water suspension containing cobalt oxide particles;
adding a magnesium salt to the water suspension containing the cobalt oxide particles; and
adjusting a pH value of the water suspension to coat a surface of each cobalt oxide particle with magnesium hydroxide.
In a tenth aspect of the present invention, there is provided a process for producing the cathode active material for a non-aqueous electrode secondary cell defined in the third aspect, comprising:
mixing the cobalt oxide particles defined in the first or second aspect with a lithium compound; and
heat-treating the resultant mixture.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph showing the relationship between the amount of magnesium substituted for each of the cathode active materials obtained in Examples 2 and 10 to 16 and Comparative Examples 3 to 6, and the a-axis length of lattice constant of the cathode active material, wherein ♦ indicates plots for the Examples, and Δ indicates plots for the Comparative Examples (there is a plot of the same value).
FIG. 2 is a graph showing the relationship between the amount of magnesium substituted for each of the cathode active materials obtained in Examples 2 and 10 to 16 and Comparative Examples 3 to 6, and the c-axis length of lattice constant of the cathode active material, wherein ♦ indicates plots for the Examples, and Δ indicates plots for the Comparative Example (there is a plot of the same value).
FIG. 3 is a graph showing the relationship between the amount of magnesium substituted for each of the cathode active materials obtained in Examples 2, 10 to 16, 18 and 22 to 24 and Comparative Examples 3 to 6 and 8, and the electron conductivity of the cathode active material, wherein ♦ indicates plots for the Examples, and Δ indicates plots for the Comparative Examples (there are plots of the same value).
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in detail below.
First, the cobalt oxide particles (I) and (I′) of the present invention are described.
The cobalt oxide particles (I) of the present invention are cobalt oxide particles containing magnesium, and have a composition represented by the formula:
(Co (1−x) Mg x ) 3 O 4
wherein x is 0.001 to 0.15.
When the magnesium content x of the cobalt oxide particles is less than 0.001, the cathode active material obtained by using such cobalt oxide particles may fail to show a sufficient heat stability. When the magnesium content x of the cobalt oxide particles is more than 0.15, it may be difficult to industrially produce single-phase lithium cobaltate therefrom.
The cobalt oxide particles (I′) of the present invention are cobalt oxide particles containing magnesium and aluminum, and have a composition represented by the formula:
(Co (1−x) Mg x ) 3 O 4 ·3yAl(OH) 3
wherein x is 0.001 to 0.15 and y is 0.001 to 0.05.
When the magnesium content x of the cobalt oxide particles is less than 0.001, the cathode active material obtained by using such cobalt oxide particles may fail to show a sufficient heat stability. When the magnesium content x of the cobalt oxide particles is more than 0.15, it may be difficult to industrially produce single-phase lithium cobaltate therefrom. When the aluminum content y of the cobalt oxide particles is less than 0.001, the cathode active material obtained by using such cobalt oxide particles may fail to show a sufficient good cycle performance. When the aluminum content y of the cobalt oxide particles is more than 0.05, it may be difficult to industrially produce single-phase lithium cobaltate therefrom.
The cobalt oxide particles (I) and (I′) of the present invention have an average particle diameter of usually not more than 0.2 μm, preferably 0.01 to 0.15 μm, more preferably 0.05 to 0.12 μm. Cobalt oxide particles having an average particle diameter of more than 0.2 μm may be difficult to industrially produce.
The cobalt oxide particles (I) and (I′) of the present invention have a BET specific surface area value of usually 0.5 to 50 m 2 /g, preferably 1.0 to 40 m 2 /g, more preferably 5.0 to 25 m 2 /g. Cobalt oxide particles having a BET specific surface area value of less than 0.5 m 2 /g may be difficult to industrially produce. When the BET specific surface area value is more than 50 m 2 /g, the obtained cobalt oxide particles may fail to show excellent particle characteristics when subjected to various processes such as mixing and heat-treatment.
Then, the cobalt oxide particles (II) of the present invention are described.
The cobalt oxide particles (II) of the present invention are cobalt oxide particles each surface-coated with magnesium hydroxide, and having a composition represented by the formula:
(1−x) Co 3 O 4 ·3xMg(OH) 2
wherein x is 0.001 to 0.15.
When the amount x of magnesium of the cobalt oxide particles is less than 0.001, the cathode active material obtained by using such cobalt oxide particles may fail to show a sufficient heat stability. When the amount x of magnesium of the cobalt oxide particles is more than 0.15, it may be difficult to industrially produce single-phase lithium cobaltate therefrom.
The cobalt oxide particles (II) of the present invention have an average particle diameter of usually not more than 0.2 μm, preferably 0.01 to 0.15 μm, more preferably 0.05 to 0.12 μm. Cobalt oxide particles having an average particle diameter of more than 0.2 μm may be difficult to industrially produce.
The cobalt oxide particles (II) of the present invention have a BET specific surface area value of usually 0.5 to 50 m 2 /g, preferably 1.0 to 40 m 2 /g, more preferably 5.0 to 25 m 2 /g. Cobalt oxide particles having a BET specific surface area value of less than 0.5 m 2 /g may be difficult to industrially produce. When the BET specific surface area value is more than 50 m 2 /g, the obtained cobalt oxide particles may fail to show excellent particle characteristics when subjected to various processes such as mixing and heat-treatment.
Next, the process for producing the cobalt oxide particles (I) is described below.
The cobalt oxide particles (I) can be produced by adding a magnesium salt to a solution containing a cobalt salt; subjecting the resultant solution to neutralization reaction by adding an aqueous alkali solution thereto; then subjecting the thus neutralized solution to oxidation reaction; and, if required, heat-treating then obtained material.
Examples of the magnesium salt may include magnesium sulfate, magnesium nitrate, magnesium phosphate, magnesium hydrogenphosphate, magnesium carbonate or the like.
Examples of the cobalt salt may include cobalt sulfate, cobalt nitrate, cobalt acetate, cobalt carbonate or the like.
Examples of the aqueous alkali solution may include aqueous solutions containing sodium hydroxide, potassium hydroxide, sodium carbonate, ammonia or the like. Among these aqueous solutions, an aqueous sodium hydroxide solution, an aqueous sodium carbonate solution and a mixed solution thereof are preferred.
The amount of magnesium added is usually 0.1 to 20 mol %, preferably 1 to 18 mol % based on cobalt.
The amount of the aqueous alkali solution used in the neutralization reaction is preferably 1.0 to 1.2 equivalents based on one equivalent of a neutralized part of whole metal salts contained in the cobalt oxide particles (I).
The oxidation reaction may be conducted by passing an oxygen-containing gas through the reaction system. The reaction temperature is preferably not less than 30° C., more preferably 30 to 95° C., and the reaction time is preferably 5 to 20 hours.
The process for producing the cobalt oxide particles (I′) is described below.
The cobalt oxide particles (I′) can be produced by adding an aluminum salt to a suspension containing the cobalt oxide particles (I); adjusting a pH value of the resultant solution by adding an aqueous alkali solution thereto, thereby coating the surface of the cobalt oxide particle with aluminum hydroxide; and, if required, heat-treating then obtained material.
Examples of the aluminum salt may include aluminum sulfate, aluminum nitrate, sodium aluminum or the like.
The amount of aluminum added is usually 0.1 to 5 mol %, preferably 0.1 to 3 mol % based on cobalt.
Next, the process for producing the cobalt oxide particles (II) according to the present invention is described below.
The cobalt oxide particles (II) of the present invention can be produced by subjecting a solution containing a cobalt salt to neutralization reaction by adding an aqueous alkali solution thereto; subjecting the neutralized product to oxidation reaction to obtain cobalt oxide particles; adding a magnesium salt to the reaction solution containing the cobalt oxide particles; adjusting a pH value of the resultant solution by adding an aqueous alkali solution thereto, thereby coating the surface of the cobalt oxide particle with magnesium hydroxide; and, if required, heat-treating then obtained material.
As the cobalt salt and magnesium salt, there may be used the same as described above.
As the aqueous alkali solution, there may be used the same aqueous alkali solutions as described above.
The amount of magnesium added is usually 0.1 to 20 mol %, preferably 1 to 18 mol % based on cobalt.
The amount of the aqueous alkali solution used in the neutralization reaction for obtaining the cobalt oxide particles is preferably 1.0 to 1.2 equivalents based on one equivalent of a neutralized part of the cobalt salt.
The oxidation reaction may be conducted by passing an oxygen-containing gas through the reaction system. The reaction temperature is preferably not less than 30° C., more preferably 30 to 95° C., and the reaction time is preferably 5 to 20 hours.
The amount of the aqueous alkali solution used for the surface treatment with magnesium hydroxide is preferably 1.0 to 1.2 equivalents based on one equivalent of a neutralized part of the magnesium salt.
The pH value of the reaction solution upon the surface treatment is preferably 11 to 13.
Next, the cathode active material for a non-aqueous electrolyte secondary cell (hereinafter referred to merely as “cathode active material”) according to the present invention is described.
In the case where the composition of the cathode active material (III) according to the present invention is represented by the following formula:
Li(Co (1−x) Mg x )O 2 ,
the magnesium content x is usually 0.001 to 0.15, preferably 0.01 to 0.10.
When the magnesium content x of the cathode active material is less than 0.001, the effect of improving the heat stability of the cathode active material may become insufficient. When the magnesium content x is more than 0.15, the initial discharge capacity of the cathode active material tends to be considerably deteriorated.
In the case where the composition of the cathode active material (III′) according to the present invention is represented by the following formula:
Li(Co (1−x−y) Mg x Al y )O 2 ,
the magnesium content x is usually 0.001 to 0.15, preferably 0.01 to 0.10 and aluminum content y is usually 0.001 to 0.05, preferably 0.001 to 0.03.
When the magnesium content x of the cathode active material is less than 0.001, the effect of improving the heat stability of the cathode active material may become insufficient. When the magnesium content x is more than 0.15, the initial discharge capacity of the cathode active material tends to be considerably deteriorated. When the aluminum content y of the cobalt oxide particles of the present invention is less than 0.001, the cathode active material obtained by using such cobalt oxide particles may fail to show a sufficient good cycle performance. When the aluminum content y of the cobalt oxide particles is more than 0.05, it may be difficult to industrially produce single-phase lithium cobaltate therefrom.
The cathode active material (III) and (III′) of the present invention has an average particle diameter of usually 1.0 to 20 μm, preferably 2.0 to 10 μm. When the average particle diameter of the cathode active material is less than 1.0 μm, the obtained cathode active material suffers from disadvantages such as low packing density and increased reactivity with an electrolyte solution. The cathode active material having an average particle diameter of more than 20 μm may be difficult to industrially produce.
As to the lattice constant of the cathode active material (III) and (III′) of the present invention, the a-axis length thereof is usually from 0.090x+2.816 Å to 0.096x+2.821 Å, and the c-axis length thereof is usually 0.460x+14.053 Å to 0.476x+14.063 Å, wherein x has the same meaning as defined above. When the a-axis and c-axis lengths are less than the above-specified ranges, the lattice constant of the obtained lithium cobaltate particles may become small, thereby failing to attain a sufficient heat stability. When the a-axis and c-axis lengths are more than the above-specified ranges, a large amount of magnesium may be substituted for the cathode active material, resulting in deterioration in initial discharge capacity thereof.
The cathode active material (III) and (III′) of the present invention has a BET specific surface area value of preferably 0.1 to 1.6 m 2 /g, more preferably 0.3 to 1.0 m 2 /g. The cathode active material having a BET specific surface area of less than 0.1 m 2 /g may be difficult to industrially produce. When the BET specific surface area thereof is more than 1.6 m 2 /g, the obtained cathode active material may tend to suffer from disadvantages such as low packing density and increased reactivity with an electrolyte solution.
The cathode active material (III) and (III′) of the present invention has a volume resistivity value of preferably 1.0×10 to 1.0×10 6 Ω·cm, more preferably 1.0×10 to 1.0×10 5 Ω·cm.
The cathode active material (III) and (III′) of the present invention has an electron conductivity log(Ωcm) of preferably −0.5 to −5.0, more preferably −0.5 to −4.9.
The cathode active material (III) and (III′) of the present invention preferably has a crystallite size of 400 to 1,200 Å.
Next, the process for producing the cathode active material according to the present invention will be described below.
The cathode active material (III) of the present invention can be produced by mixing the cobalt oxide particles (I) or the cobalt oxide particles (II) with a lithium compound, and heat-treating the resultant mixture.
The mixing of the cobalt oxide particles (I) or the cobalt oxide particles (II) with the lithium compound may be performed by either a dry method or a wet method as long as these materials can be uniformly mixed with each other.
The mixing molar ratio of lithium to a sum of cobalt and magnesium contained in the cobalt oxide particles (I) or the cobalt oxide particles (II) is preferably 0.95 to 1.05.
The cathode active material (III′) of the present invention can be produced by mixing the cobalt oxide particles (I) or the cobalt oxide particles (II) with both of a lithium compound and an aluminum compound such as aluminum hydroxide, aluminum oxide or the like, and heat-treating the resultant mixture.
The mixing of the cobalt oxide particles (I) or the cobalt oxide particles (II) with both of the lithium compound and the aluminum salt may be performed by either a dry method or a wet method as long as these materials can be uniformly mixed with each other.
The mixing molar ratio of lithium to a sum of cobalt and magnesium contained in the cobalt oxide particles (I) or the cobalt oxide particles (II) is preferably 0.95 to 1.05. The mixing molar ratio of aluminum to a sum of cobalt and magnesium contained in the cobalt oxide particles (I) or the cobalt oxide particles (II) is preferably 0.001 to 0.05.
The cathode active material (III′) of the present invention can be produced by mixing the cobalt oxide particles (I′) with a lithium compound, and heat-treating the resultant mixture.
The mixing of the cobalt oxide particles (I′) with the lithium compound may be performed by either a dry method or a wet method as long as these materials can be uniformly mixed with each other.
The mixing molar ratio of lithium to a sum of cobalt, magnesium and aluminum contained in the cobalt oxide particles (I′) is preferably 0.95 to 1.05.
The heat-treating temperature is preferably 600 to 950° C. at which LiCoO 2 having a high-temperature regular phase can be produced. When the heat-treating temperature is less than 600° C., LiCoO 2 made of a low-temperature phase having a pseudo-spinel structure is disadvantageously produced. When the heat-treating temperature is more than 950° C., LiCoO 2 made of a high-temperature irregular phase in which lithium and cobalt are dispersed at random positions, is disadvantageously produced. The heat-treating atmosphere is preferably an oxidative gas atmosphere, and the reaction time is preferably 5 to 20 hours.
Next, the cathode for a non-aqueous electrolyte secondary cell using the cathode active material (III) or (III′) of the present invention is described.
In the case where a cathode is produced using the cathode active material of the present invention, the cathode active material is mixed with a conductive agent and a binder by an ordinary method. As the preferred conductive agent, there may be used acetylene black, carbon black, graphite or the like. As the preferred binder, there may be used polytetrafluoroethylene, polyvinylidene fluoride or the like.
A secondary cell (lithium battery) according to the present invention comprises a pair of electrodes disposed by means of a separator in the presence of a lithium ion conductive electrolyte.
A cathode and an anode are disposed in a container so as to be opposed to each other with a separator composed of a porous thermoplastic resin film. A lithium ion conductive electrolyte is present in the container.
In the secondary cell of the present invention, it is only necessary that the above-described specific cathode active material is used for at least one electrode, preferably a cathode active material, and the other active materials may be the known substances which are conventionally used for a lithium battery.
The secondary cell produced by using the cathode active material of the present invention, is constituted by the above cathode as well as an anode and an electrolyte.
As an active material for the anode, there may be used metallic lithium, lithium/aluminum alloy, lithium/tin alloy, graphite or the like.
In addition, as a solvent for the electrolyte solution, there may be used a mixed solvent of ethylene carbonate and diethyl carbonate, an organic solvent containing at least one solvent selected from the group consisting of carbonates such as propylene carbonate and dimethyl carbonate and ethers such as dimethoxyethane, and the like.
Further, as the electrolyte, there may be used a solution prepared by dissolving the above lithium phosphate hexafluoride or at least one lithium salt selected from the group consisting of lithium perchlorate, lithium borate tetrafluoride and the like, in the above solvent.
The secondary cell produced using the cathode active material (III) of the present invention exhibits an initial discharge capacity of preferably about 130 to about 165 mAh/g, and a heat stability of preferably not less than 200° C., more preferably 205 to 250° C. when measured by the below-mentioned evaluation method.
The secondary cell produced using the cathode active material (III′) of the present invention exhibits an initial discharge capacity of preferably about 130 to about 165 mAh/g, a heat stability of preferably not less than 215° C., more preferably 225 to 250° C. when measured by the below-mentioned evaluation method, and a capacity retention percentage after 50 cycles at 60° C. as high as not less than 95%, preferably 95 to 99%.
The point of the present invention is that the cathode active material produced using the cobalt oxide particles (I), (I′) or (II) as a precursor thereof can show a high initial discharge capacity required for secondary cells, and is excellent in heat stability.
The reason why the cathode active material of the present invention can show a high initial discharge capacity, is considered as follow. That is, the cathode active material contains magnesium in such an amount as not to deteriorate the inherent initial discharge capacity of LiCoO 2 .
Further, the reason why the cathode active material of the present invention can exhibit a large lattice constant, is considered by the present inventors as follows. That is, since magnesium is incorporated into the cobalt oxide particles (I), (I′) or (II) at a stage of synthesis thereof, or the magnesium hydroxide is adhered onto the surface of the cobalt oxide particles, magnesium and cobalt are uniformly distributed in the cathode active material at atomic level. Therefore, it is suggested by the present inventors that the cobalt sites of the cathode active material obtained by using the cobalt oxide particles (I), (I′) or (II) can be uniformly replaced with magnesium.
On the other hand, when the lithium compound, the cobalt compound and magnesium are dry-mixed with each other and then calcined by conventional methods, magnesium cannot be uniformly distributed in the cathode active material, thereby failing to obtain the effect of the present invention.
Also, the reason why the cathode active material of the present invention can exhibit an excellent heat stability, is considered as follows, though not clearly determined yet. That is, it is suggested that the crystal structure of the cathode active material can be stabilized by incorporating magnesium thereinto.
Further, the cathode active material of the present invention can exhibit a lower volume resistivity value and a higher electron conductivity as compared to conventional cathode active materials prepared by a dry method which have the same amount of magnesium. The reason therefor is not clearly determined yet, but is suggested to be that excess electrons are generated by replacing Co 3+ with Mg 2+ so that the electron conductivity becomes high and the volume resistivity value becomes low.
By using the cobalt oxide particles and the cathode active material according to the present invention, it becomes possible to obtain a non-aqueous electrolyte secondary cell capable of retaining a good initial discharge capacity required for secondary cells, and exhibiting an improved heat stability.
EXAMPLES
The present invention is described in more detail by Examples and Comparative Examples, but the Examples are only illustrative and, therefore, not intended to limit the scope of the present invention.
Various properties were evaluated by the following methods.
(1) The cathode active material was identified using a Powder X-ray Diffraction Analyzer (manufactured by Rigaku Denki Kogyo Co., Ltd.; Cu-Kα; 40 kV, 40 mA). Also, the lattice constant of the cathode active material was calculated from respective diffraction peaks of the powder X-ray diffraction curve.
(2) The crystallite size of the cathode active material was calculated from the respective diffraction peaks of the powder X-ray diffraction curve obtained above.
(3) The volume resistivity of the cathode active material was measured using a Wheatstone bridge-type 2768 insulation resistance meter (manufactured by Yokogawa Denki Co., Ltd.).
(4) The elemental analysis was conducted using an inductively coupled high-frequency plasma atomic emission spectroscope “SPS-4000 Model” (manufactured by Seiko Denshi Kogyo Co., Ltd.).
(5) The cell characteristics of the cathode active material were evaluated by testing a coin-shaped cell constituted from a cathode, an anode and an electrolyte solution prepared by the following methods.
<Preparation of Cathode>
The cathode active material, acetylene black as a conductive agent, and polyvinylidene fluoride as a binder were accurately weighed at a weight ratio of 85:10:5, and intimately mixed with each other in a mortar. The resultant mixture was dispersed in N-methyl-2-pyrrolidone to prepare a cathode slurry. Then, the thus obtained slurry was applied onto an aluminum foil as a current collector to form a coating film having a thickness of 150 μm, vacuum-dried at 150° C., and then punched into a disc shape having a diameter of 16 mm, thereby producing a cathode plate.
<Preparation of Anode>
A metallic lithium foil was punched into a disc shape having a diameter of 16 mm, thereby producing an anode.
<Preparation of Electrolyte Solution>
Lithium phosphate hexafluoride (LiPF 6 ) as an electrolyte was added in an amount of 1 mol/liter to a mixed solution containing ethylene carbonate and diethyl carbonate at a volume ratio of 50:50, thereby preparing an electrolyte solution.
<Assembling of Coin-shaped Cell>
In a globe box maintained under an argon atmosphere, the above cathode and anode were fitted via a polypropylene separator in a casing made of SUS316 stainless steel. Further, the electrolyte solution was filled in the casing, thereby producing a CR2032-type coin-shaped cell.
<Evaluation of Cell>
The above-produced coin-shaped cell was subjected to a charge/discharge cycle test for secondary cells. The charge and discharge cycles were repeated at a cathode current density of 0.2 mA/cm 2 while varying the cut-off voltage from 3.0 to 4.3 V to examine the change in discharge capacity.
<Evaluation of Heat Stability>
The above-produced coin-shaped cell was charged until the cell voltage reached 4.3 V. Then, the cathode active material was taken out from the cell, and filled in a container for thermal analysis, and then the container was sealed. The cathode active material filled in the container was subjected to DSC measurement using a differential scanning calorimeter “DSC6200” (manufactured by Seiko Instruments, Co., Ltd) at a temperature rise rate of 10° C./min. From the measurement results, the heat stability was expressed by the temperature at which heat generation was initiated. Meanwhile, the above evaluation procedure was conducted at a temperature of 30 to 400° C., and all works up to filling in the container were performed in the globe box having a dew point of −60° C. or lower.
Example 1
<Production of Cobalt Oxide Particles (I)>
Magnesium sulfate (5.3 mol % based on cobalt) was added to a solution containing cobalt in an amount of 0.5 mol/liter. In addition, an aqueous sodium hydroxide solution was added in an amount of 1.05 equivalents based on one equivalent of a neutralized part of a sum of cobalt and magnesium, to the resultant solution, thereby subjecting the solution to a neutralization reaction. Then, the obtained solution was subjected to oxidation reaction at 90° C. for 20 hours while passing air therethrough, thereby obtaining magnesium-containing cobalt oxide particles. It was conformed that the thus obtained magnesium-containing cobalt oxide particles were composed of a Co 3 O 4 single phase, and had a Mg content of 5.0 mol % (x in (Co (1−x) Mg x ) 3 O 4 is 0.05), an average particle diameter of 0.1 μm and a BET specific surface area value of 13.2 m 2 /g.
Example 2
<Production of Cathode Active Material>
The magnesium-containing cobalt oxide particles obtained in Example 1 were intimately mixed with a lithium compound such that the molar ratio of Li to a sum of cobalt and magnesium was 1.03. The resultant mixed particles were calcined at 900° C. for 10 hours under an oxidative atmosphere, thereby obtaining magnesium-containing lithium cobaltate particles.
As a result of the X-ray diffraction analysis of the thus obtained magnesium-containing lithium cobaltate particles, it was confirmed that the magnesium-containing lithium cobaltate particles were composed of a lithium cobaltate single phase without impurity phase, and had an average particle size of 5.0 μm, a BET specific surface area value of 0.5 m 2 /g, an a-axis length of lattice constant of 2.821 Å, a c-axis length of lattice constant of 14.082 Å, a crystallite size of 642 Å, a volume resistivity value of 2.1×10 Ωcm and an electron conductivity log(1/Ωcm) of −1.2. In addition, when the composition of the magnesium-containing lithium cobaltate particles was represented by the formula: LiCo 1−x Mg x O 2 , it was confirmed that the magnesium content x was 0.045.
The thus obtained magnesium-containing lithium cobaltate particles were used as a cathode active material to prepare a coin-shaped cell. As a result, it was confirmed that the thus prepared coin-shaped cell exhibited an initial discharge capacity of 147 mAh/g and a heat stability of 239° C.
Examples 3 to 9
The same procedure as defined in Example 1 was conducted except that the magnesium content was changed variously, thereby obtaining cobalt oxide particles.
Essential production conditions and various properties of the obtained cobalt oxide particles are shown in Table 1.
Examples 10 to 16
The same procedure as defined in Example 2 was conducted except that kind of cobalt oxide particles, mixing ratio of lithium and calcination temperature were changed variously, thereby obtaining cathode active materials and producing coin-shaped cells using the respective cathode active materials.
Essential production conditions are shown in Table 2, and various properties of the obtained cathode active materials and cell characteristics of the obtained coin-shaped cells are shown in Table 3.
Comparative Examples 1 to 6
In Comparative Example 1, cobalt oxide particles containing no magnesium were produced. In Comparative Example 3, lithium cobaltate particles containing no magnesium were produced. In Comparative Examples 4 to 6, the cobalt oxide particles obtained in Comparative Example 2 were dry-mixed with the magnesium raw material and the lithium raw material, and the resultant mixtures were calcined at the respective temperature, thereby obtaining lithium cobaltate particles containing magnesium.
Essential production conditions are shown in Table 2, and various properties of the obtained cathode active materials and cell characteristics of the obtained coin-shaped cells are shown in Table 3.
Example 17
<Production of Cobalt Oxide Particles (II)>
An aqueous sodium hydroxide solution was added in an amount of 1.05 equivalents based on one equivalent of a neutralized part of cobalt, to a solution containing cobalt in an amount of 0.5 mol/liter, thereby subjecting the resultant solution to a neutralization reaction. Then, the obtained solution was subjected to oxidation reaction at 90° C. for 20 hours while passing air therethrough, thereby obtaining cobalt oxide particles. Then, magnesium sulfate (1.0 mol % based on cobalt) was added to the resultant reaction solution containing the cobalt oxide particles, and further an aqueous sodium hydroxide solution was added in an amount required for neutralization of the magnesium salt, thereby treating the surface of the cobalt oxide particles with magnesium hydroxide. The pH value of the obtained reaction solution was 11. It was conformed that the thus obtained cobalt oxide particles surface-treated with magnesium hydroxide were composed of a Co 3 O 4 single phase, and had a Mg content of 1.0 mol % (x in (1−x)Co 3 O 4 ·3xMg(OH) 2 is 0.01), an average particle diameter of 0.1 μm and a BET specific surface area value of 13.5 m 2 /g.
Example 18
<Production of Cathode Active Material>
The cobalt oxide particles surface-treated with magnesium hydroxide which were obtained in Example 17, were intimately mixed with a lithium compound such that the molar ratio of Li to a sum of cobalt and magnesium was 1.03. The resultant mixed particles were calcined at 900° C. for 10 hours under an oxidative atmosphere, thereby obtaining magnesium-containing lithium cobaltate particles.
As a result of the X-ray diffraction analysis of the thus obtained magnesium-containing lithium cobaltate particles, it was confirmed that the magnesium-containing lithium cobaltate particles were composed of a lithium cobaltate single phase without impurity phase, and had an average particle diameter of 4.7 μm, a BET specific surface area value of 0.5 m 2 /g, an a-axis length of lattice constant of 2.817 Å, a c-axis length of lattice constant of 14.065 Å, a crystallite size of 631 Å, a volume resistivity value of 7.1×10 4 Ωcm and an electron conductivity log(1/Ωcm) of −4.9. In addition, when the composition of the magnesium-containing lithium cobaltate particles was represented by the formula: LiCo 1−x Mn x O 2 , it was confirmed that the magnesium content x was 0.01.
The thus obtained magnesium-containing lithium cobaltate particles were used as a cathode active material to prepare a coin-shaped cell. As a result, it was confirmed that the thus prepared coin-shaped cell exhibited an initial discharge capacity of 161 mAh/g and a heat stability of 216° C.
Examples 19 to 21 and Comparative Example 7
The same procedure as defined in Example 17 was conducted except that the amount of magnesium added for the surface treatment with magnesium hydroxide was changed variously, thereby obtaining cobalt oxide particles surface-treated with magnesium hydroxide.
Essential production conditions and various properties of the obtained cobalt oxide particles surface-treated with magnesium hydroxide are shown in Table 4.
Examples 22 to 24 and Comparative Example 8
The same procedure as defined in Example 18 was conducted except that kind of cobalt oxide particles and mixing ratio of lithium were changed variously, thereby obtaining cathode active materials and producing coin-shaped cells using the cathode active materials.
Essential production conditions are shown in Table 5, and various properties of the obtained cathode active materials and cell characteristics of the obtained coin-shaped cells are shown in Table 6.
Thus, it was confirmed that the coin-shaped cells produced using the cathode active materials of the present invention exhibited an initial discharge capacity of 130 to 160 mAh/g and a heat stability as high as not less than 200° C.
On the contrary, as apparent from the results of Comparative Examples, when the magnesium content x is more than 0.2, the initial discharge capacity was considerably lowered. Further, when the respective elements were mixed with each other by a dry method, the effect of improving the heat stability based on the amount of magnesium added was deteriorated.
Example 25
<Production of Cobalt Oxide Particles (I′)>
Magnesium sulfate (1.0 mol % based on cobalt) was added to a solution containing cobalt in an amount of 0.5 mol/liter. Further, an aqueous sodium hydroxide solution was added in an amount of 1.05 equivalents based on one equivalent of a neutralized part of a sum of cobalt and magnesium, to the resultant solution, thereby subjecting the solution to a neutralization reaction. Then, the obtained solution was subjected to oxidation reaction at 90° C. for 20 hours while passing air therethrough, thereby obtaining magnesium-containing cobalt oxide particles. Successively, aluminum sulfate (1.0 mol % based on cobalt) was added to the reaction solution containing the thus obtained magnesium-containing cobalt oxide particles, and further an aqueous sodium hydroxide solution was added in an amount requiring for neutralizing the aluminum sulfate to the solution, thereby treating the surface of the respective magnesium-containing cobalt oxide particles with aluminum hydroxide. The pH value of the reaction solution treated was 9. It was conformed that the thus obtained magnesium-containing cobalt oxide particles surface-treated with aluminum hydroxide were composed of a Co 3 O 4 single phase, and had a Mg content of 1.0 mol % and an aluminum content of 1.0 mol % (x and y of (Co (1−x) Mg x ) 3 O 4 ·3yAl(OH) 3 are both 0.01), an average particle diameter of 0.1 μm and a BET specific surface area value of 13.4 m 2 /g.
Example 26
<Production of Cathode Active Material (III′)>
The magnesium-containing cobalt oxide particles surface-treated with aluminum hydroxide obtained in Example 25 were intimately mixed with a lithium compound such that the molar ratio of Li to a sum of cobalt, magnesium and aluminum was 1.03. The resultant mixed particles were calcined at 900° C. for 10 hours under an oxygen atmosphere, thereby obtaining lithium cobaltate particles containing magnesium and aluminum.
As a result of the X-ray diffraction analysis of the thus obtained lithium cobaltate particles containing magnesium and aluminum, it was confirmed that the lithium cobaltate particles were composed of a lithium cobaltate single phase without impurity phase, and had an average particle diameter of 4.9 μm, a BET specific surface area value of 0.5 m 2 /g, an a-axis length of lattice constant of 2.817 Å, a c-axis length of lattice constant of 14.068 Å, a crystallite size of 652 Å, a volume resistivity value of 7.1×10 4 Ωcm and an electron conductivity log(1/Ωcm) of −4.9. In addition, as to the magnesium and aluminum contents, when the composition of the lithium cobaltate particles containing magnesium and aluminum was represented by the formula: LiCo (1−x−y) Mg x Al y O 2 , it was confirmed that the magnesium content x was 0.01 and the aluminum content y was 0.01.
The thus obtained lithium cobaltate particles containing magnesium and aluminum were used as a cathode active material to prepare a coin-shaped cell. As a result, it was confirmed that the thus prepared coin-shaped cell exhibited an initial discharge capacity of 158 mAh/g, a capacity retention percentage of 98% after 100 cycles at 60° C., and a heat stability of 219° C.
Example 27
<Production of Cobalt Oxide Particles (I)>
Magnesium sulfate (1.0 mol % based on cobalt) was added to a solution containing cobalt in an amount of 0.5 mol/liter. Further, an aqueous sodium hydroxide solution was added in an amount of 1.05 equivalents based on one equivalent of a neutralized part of a sum of cobalt and magnesium, to the resultant solution, thereby subjecting the solution to a neutralization reaction. Then, the obtained solution was subjected to oxidation reaction at 90° C. for 20 hours while passing air therethrough, thereby obtaining magnesium-containing cobalt oxide particles. It was conformed that the thus obtained magnesium-containing cobalt oxide particles were composed of a Co 3 O 4 single phase, and had a Mg content of 1.0 mol % (x of (Co (1−x) Mg x ) 3 0 4 is 0.01), an average particle diameter of 0.1 μm and a BET specific surface area value of 13.0 m 2 /g.
Example 28
<Production of Cathode Active Material (III′)>
The magnesium-containing cobalt oxide particles obtained in Example 27 were intimately mixed with an aluminum compound and a lithium compound such that the molar ratio of Li and Al to a sum of cobalt, magnesium and aluminum was 1.03 and 0.01, respectively. The resultant mixed particles were calcined at 900° C. for 10 hours under an oxidative atmosphere, thereby obtaining lithium cobaltate particles containing magnesium and aluminum.
As a result of the X-ray diffraction analysis of the thus obtained lithium cobaltate particles containing magnesium and aluminum, it was confirmed that the lithium cobaltate particles were composed of a lithium cobaltate single phase without impurity phase, and had an average particle diameter of 4.8 μm, a BET specific surface area value of 0.5 m 2 /g, an a-axis length of lattice constant of 2.817 Å, a c-axis length of lattice constant of 14.068 Å, a crystallite size of 645 Å, a volume resistivity value of 7.0×10 Ωcm and an electron conductivity log(1/Ωcm) of −4.8. In addition, as to the magnesium and aluminum contents, when the composition of the lithium cobaltate particles containing magnesium and aluminum was represented by the formula: LiCo (1−x−y) Mg x Al y O 2 , it was confirmed that the magnesium content x was 0.01 and the aluminum content y was 0.01.
The thus obtained lithium cobaltate particles containing magnesium and aluminum were used as a cathode active material to prepare a coin-shaped cell. As a result, it was confirmed that the thus prepared coin-shaped cell exhibited an initial discharge capacity of 158 mAh/g, a capacity retention percentage of 98% after 100 cycles at 60° C., and a heat stability of 220° C.
Example 29
<Production of Cobalt Oxide Particles (I)>
An aqueous sodium hydroxide solution was added in an amount of 1.05 equivalents based on one equivalent of a neutralized part of cobalt to a solution containing cobalt in an amount of 0.5 mol/liter, thereby subjecting the mixed solution to a neutralization reaction. Then, the obtained solution was subjected to oxidation reaction at 90° C. for 20 hours while passing air therethrough, thereby obtaining cobalt oxide particles. Successively., magnesium sulfate (1.0 mol % based on cobalt) was added to the reaction solution containing the thus obtained cobalt oxide particles, and further an aqueous sodium hydroxide solution was added in an amount requiring for neutralizing the magnesium sulfate to the solution, thereby treating the surface of the respective cobalt oxide particles with magnesium hydroxide. The pH value of the reaction solution treated was 11. It was conformed that the thus obtained cobalt oxide particles surface-treated with magnesium hydroxide were composed of a Co 3 O 4 single phase, and had a Mg content of 1.0 mol % (x of ((1−x)Co 3 O 4 ·3xMg(OH) 2 is 0.01), an average particle diameter of 0.1 μm and a BET specific surface area value of 13.5 m 2 /g.
Example 30
<Production of Cathode Active Material (III′)>
The cobalt oxide particles surface-treated with magnesium hydroxide obtained in Example 29 were intimately mixed with an aluminum compound and a lithium compound such that the molar ratio of Li and Al to a sum of cobalt, magnesium and aluminum was 1.03 and 0.01, respectively. The resultant mixed particles were calcined at 900° C. for 10 hours under an oxidative atmosphere, thereby obtaining lithium cobaltate particles containing magnesium and aluminum.
As a result of the X-ray diffraction analysis of the thus obtained lithium cobaltate particles containing magnesium and aluminum, it was confirmed that the lithium cobaltate particles were composed of a lithium cobaltate single phase without impurity phase, and had an average particle diameter of 4.8 μm, a BET specific surface area value of 0.5 m 2 /g, an a-axis length of lattice constant of 2.817 Å, a c-axis length of lattice constant of 14.066 Å, a crystallite size of 650 Å, a volume resistivity value of 7.1×10 4 Ωcm and an electron conductivity log(1/Ωcm) of −4.9. In addition, as to the magnesium and aluminum contents, when the composition of the lithium cobaltate particles containing magnesium and aluminum was represented by the formula: LiCo (1−x−y) Mg x Al y O 2 , it was confirmed that the magnesium content x was 0.01 and the aluminum content y was 0.01.
The thus obtained lithium cobaltate particles containing magnesium and aluminum were used as a cathode active material to prepare a coin-shaped cell. As a result, it was confirmed that the thus prepared coin-shaped cell exhibited an initial discharge capacity of 158 mAh/g, a capacity retention percentage of 98% after 100 cycles at 60° C., and a heat stability of 218° C.
TABLE 1
Production conditions of cobalt oxide
Examples
Amount of
and
Amount of Mg
alkali added
Comparative
added (Mg/Co)
Kind of aqueous
(equivalent
Examples
(mol %)
alkali solution
ratio)
Example 1
5.3
NaOH
1.05
Example 3
1.0
NaOH
1.05
Example 4
3.1
NaOH
1.05
Example 5
6.5
NaOH
1.05
Example 6
8.7
NaOH
1.05
Example 7
9.9
NaOH
1.05
Example 8
6.5
NaOH
1.05
Example 9
6.5
NaOH
1.05
Comparative
0
NaOH
1.05
Example 1
Comparative
—
—
—
Example 2
Examples
Production conditions of cobalt oxide
and
Oxidation reaction
Oxidation reaction
Comparative
temperature
time
Examples
(° C.)
(hr)
Example 1
90
20
Example 3
90
20
Example 4
90
20
Example 5
90
20
Example 6
90
20
Example 7
90
20
Example 8
90
20
Example 9
90
20
Comparative
90
20
Example 1
Comparative
—
—
Example 2
Examples
Properties of cobalt oxide
and
Average particle
BET specific
Comparative
Mg content
diameter
surface area
Examples
(mol %)
(μm)
(m 2 /g)
Example 1
5.0
0.1
13.2
Example 3
1.0
0.1
13.6
Example 4
3.0
0.1
13.1
Example 5
6.0
0.1
13.6
Example 6
8.0
0.1
13.3
Example 7
9.0
0.1
13.9
Example 8
6.0
0.1
13.4
Example 9
6.0
0.1
13.6
Comparative
0.0
0.1
13.0
Example 1
Comparative
—
1.0
1.3
Example 2
TABLE 2
Production conditions of lithium
Kind of
cobaltate
Examples and
cobalt oxide
Mixing ratio between cobalt oxide
Comparative
particles
particles and magnesium salt
Examples
used
(molar ratio of Mg to Co)
Example 2
Example 1
contained in cobalt oxide
particles
Example 10
Example 3
contained in cobalt oxide
particles
Example 11
Example 4
contained in cobalt oxide
particles
Example 12
Example 5
contained in cobalt oxide
particles
Example 13
Example 6
contained in cobalt oxide
particles
Example 14
Example 7
contained in cobalt oxide
particles
Example 15
Example 8
contained in cobalt oxide
particles
Example 16
Example 9
contained in cobalt oxide
particles
Comparative
Comparative
0
Example 3
Example 1
Comparative
Comparative
0.02
Example 4
Example 2
Comparative
Comparative
0.03
Example 5
Example 2
Comparative
Comparative
0.05
Example 6
Example 2
Production conditions of lithium cobaltate
Examples and
Calcination
Calcination
Comparative
Li/(Co + Mg)
temperature
time
Examples
(molar ratio)
(° C.)
(hr)
Example 2
1.03
900
10
Example 10
1.02
900
10
Example 11
1.02
900
10
Example 12
1.02
900
10
Example 13
1.02
900
10
Example 14
1.02
900
10
Example 15
1.02
800
10
Example 16
1.03
900
10
Comparative
1.02
900
10
Example 3
Comparative
1.02
900
10
Example 4
Comparative
1.02
900
10
Example 5
Comparative
1.02
900
10
Example 6
TABLE 3
Properties of cathode active material
Examples and
BET specific
Comparative
Mg content
Particle size
surface area
Examples
(x)
(μm)
(m 2 /g)
Example 2
0.05
5.0
0.5
Example 10
0.01
4.7
0.5
Example 11
0.03
4.9
0.5
Example 12
0.06
5.0
0.5
Example 13
0.08
6.3
0.5
Example 14
0.09
6.9
0.4
Example 15
0.06
3.9
0.6
Example 16
0.06
6.2
0.5
Comparative
0
4.7
0.5
Example 3
Comparative
0.02
7.7
0.4
Example 4
Comparative
0.03
8.1
0.4
Example 5
Comparative
0.05
8.3
0.4
Example 6
Examples and
Properties of cathode active material
Comparative
X-ray
Lattice constant
Examples
measurement
a-axis (Å)
c-axis (Å)
Example 2
Single phase
2.821
14.082
Example 10
Single phase
2.817
14.065
Example 11
Single phase
2.820
14.072
Example 12
Single phase
2.823
14.083
Example 13
Single phase
2.824
14.090
Example 14
Single phase
2.825
14.095
Example 15
Single phase
2.821
14.081
Example 16
Single phase
2.823
14.087
Comparative
Single phase
2.816
14.053
Example 3
Comparative
Single phase
2.815
14.053
Example 4
Comparative
Single phase
2.816
14.057
Example 5
Comparative
Single phase
2.817
14.067
Example 6
Examples and
Properties of cathode active material
Comparative
Volume resistivity
Electron conductivity
Examples
(Ωcm)
log(1/Ωcm)
Example 2
2.1 × 10
−1.2
Example 10
5.6 × 10 4
−4.6
Example 11
1.2 × 10 2
−2
Example 12
2.0 × 10
−1.2
Example 13
1.5 × 10
−1.1
Example 14
1.1 × 10
−0.9
Example 15
3.7 × 10
−1.6
Example 16
2.6 × 10
−1.3
Comparative
1.2 × 10 5
−5.1
Example 3
Comparative
4.2 × 10 5
−5.6
Example 4
Comparative
8.5 × 10 4
−4.9
Example 5
Comparative
3.8 × 10 3
−3.6
Example 6
Cell characteristics
Examples and
Initial discharge
Comparative
capacity
Heat stability
Examples
(mAh/g)
(° C.)
Example 2
147
239
Example 10
161
216
Example 11
155
225
Example 12
147
239
Example 13
135
240
Example 14
130
241
Example 15
147
239
Example 16
147
239
Comparative
158
181
Example 3
Comparative
148.9
182
Example 4
Comparative
147.2
185
Example 5
Comparative
141
186
Example 6
TABLE 4
Production conditions of cobalt oxide
Examples
Amount of alkali
Oxidation
and
Kind of
added
reaction
Comparative
aqueous alkali
(equivalent
temperature
Examples
solution
ratio)
(° C.)
Example 17
NaOH
1.05
90
Example 19
NaOH
1.05
90
Example 20
NaOH
1.05
90
Example 21
NaOH
1.05
90
Comparative
NaOH
1.05
90
Example 7
Examples
Production conditions of cobalt oxide
and
Amount of Mg added
Comparative
Oxidation reaction time
(Mg/Co)
Examples
(hr)
(mol %)
Example 17
20
1.0
Example 19
20
3.1
Example 20
20
6.5
Example 21
20
8.7
Comparative
20
25
Example 7
Examples
Properties of cobalt oxide
and
Average particle
BET specific
Comparative
Mg content
diameter
surface area
Examples
(mol %)
(μm)
(m 2 /g)
Example 17
1
0.1
13.5
Example 19
3
0.1
13.6
Example 20
6
0.1
14.4
Example 21
8
0.1
15.2
Comparative
20
0.1
18.0
Example 7
TABLE 5
Kind of
Production conditions of lithium
Examples
cobalt
cobaltate
and
oxide
Li/(Co + Mg)
Calcination
Calcination
Comparative
particles
(molar
temperature
time
Examples
used
ratio)
(° C.)
(hr)
Example 18
Example 17
1.03
900
10
Example 22
Example 19
1.02
900
10
Example 23
Example 20
1.02
900
10
Example 24
Example 21
1.02
900
10
Comparative
Comparative
1.02
900
10
Example 8
Example 7
TABLE 6
Properties of cathode active material
Examples and
BET specific
Comparative
Mg content
Particle size
surface area
Examples
(x)
(μm)
(m 2 /g)
Example 18
0.01
4.7
0.5
Example 22
0.03
5.0
0.5
Example 23
0.06
5.2
0.5
Example 24
0.08
6.1
0.5
Comparative
0.2
7.1
0.4
Example 8
Examples and
Properties of cathode active material
Comparative
X-ray
Lattice constant
Examples
measurement
a-axis (Å)
c-axis (Å)
Example 18
Single phase
2.817
14.065
Example 22
Single phase
2.820
14.072
Example 23
Single phase
2.823
14.083
Example 24
Single phase
2.824
14.090
Comparative
Single phase
2.834
14.140
Example 8
Examples and
Properties of cathode active material
Comparative
Volume resistivity
Electron conductivity
Examples
(Ωcm)
log(1/Ωcm)
Example 18
7.1 × 10 4
−4.9
Example 22
1.8 × 10 2
−2.3
Example 23
2.1 × 10
−1.3
Example 24
1.5 × 10
−1.2
Comparative
9.0
−1.0
Example 8
Cell characteristics
Examples and
Initial discharge
Comparative
capacity
Heat stability
Examples
(mAh/g)
(° C.)
Example 18
161
216
Example 22
155
225
Example 23
147
239
Example 24
135
240
Comparative
112
240
Example 8
|
The present invention relates to cobalt oxide particles useful as a precursor of a cathode active material for a non-aqueous electrolyte secondary cell which is capable of showing a stable crystal structure by insertion reaction therein, and producing a non-aqueous electrolyte secondary cell having a high safety and especially a high heat stability, a process for producing the cobalt oxide particles, a cathode active material for a non-aqueous electrolyte secondary cell using the cobalt oxide particles, a process for producing the cathode active material, and a non-aqueous electrolyte secondary cell using the cathode active material.
| 2
|
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates generally to motor clutch drive systems and more specifically to such drive systems which include fluid actuated oil shear type clutch units for operatively connecting a driving motor to apparatus to be driven thereby and associated control apparatus for selectively controlling the application of actuating fluid to the clutch unit.
In numerous applications it is highly desirable to be able to smoothly accelerate a driven apparatus from a static condition to full operating speed without subjecting the apparatus to the often excessive stress and strain associated with an uneven or abrupt start. Counteracting this desire to achieve a smooth gradual startup of the driven apparatus is the desire to achieve full speed operation as rapidly as possible as well as the desire to avoid any excessive wear resulting from unnecessarily prolonged slippage of the clutch unit as it is being engaged.
Additionally, smooth startups may be particularly desirable in apparatus having multiple spaced drives provided thereon such as for example overland conveyor systems utilized in various types of mining operations so as to avoid shifting or spillage of the load thereon as well as to avoid excessive tensioning of the conveyor belt and the potential backlash which may result. In such conveyor systems it is normally necessary to progressively start the various drives in succession with a slight delay between each successive start so as to enable the sections of conveyor belt between each of the drives to be properly tensioned. The application of driving forces by proper clutch actuation so as to achieve a soft start enables the conveyor belt to tension in a generally even manner whereby any backlash or rebounding thereof is minimized. In order to insure such proper tensioning of the conveyor system, it is important that the acceleration curves of each drive unit be consistent, predictable and very accurately controllable.
Additionally, because the clutch actuating controls must be located in close proximity to the drive units and hence the conveyor equipment, they are subjected to extremely adverse operating conditions due to the high level of contaminants in the surrounding atmosphere. This problem is particularly prevalent in systems used for transporting coal both at the mines and at coal fired power plants. As a result, problems have been encountered as a result of dirt contamination of clutch actuating fluid causing plugging of control valves thereby resulting in loss of full operating control as well as increased maintenance cost and equipment downtime. Therefore, it is highly desirable to provide control valving which is substantially less sensitive to such dirt contamination.
The present invention provides a drive system particularly well suited for providing very smooth and yet rapid acceleration of driven apparatus both in terms of single and multiple drive units. The drive system includes an improved cam type control valve which is extremely resistant to operation degradation as a result of contaminants in the actuating fluid and which operates reliably to apply actuating fluid to the clutch unit in accordance with a predetermined profile so as to smoothly bring the driven apparatus up to full operating speed within a minimum amount of time and with a minimum amount of clutch slippage. The control valve is designed to be driven through a plurality of steps by a stepping motor and associated control circuitry whereby a cam member is selectively positioned with respect to an inlet orifice so as to progressively restrict fluid flow through the valve unit which in turn will result in increased actuating fluid pressure being applied to activate the clutch unit. The combination of this cam type rotary control valve with the stepping motor drive arrangement provides an extremely accurate and reliable control for actuation of the clutch unit which is substantially self-cleaning so as to substantially reduce degredation of operation as a result of contaminants in the actuating fluid.
Control circuit means are also provided for controlling the operation of the stepping motor so as to enable precise control of the equipment startup and acceleration profile. The control circuit means allows the rate of acceleration to be easily adjusted to accommodate particular operating conditions and once set will insure repeatability of the acceleration rate. Additionally, provisions may also be included in the circuit means to disengage or deactuate the clutch unit in the event of abnormal operating conditions particularly during the startup period so as to prevent damage to the clutch unit such as may occur from excessive slippage thereof.
Additional advantages and features of the present invention will become apparent from the subsequent description and the appended claims taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an overland conveyor system incorporating a plurality of motor clutch drive system which include improved control means all in accordance with the present invention;
FIG. 2 is a schematic diagram of a clutch unit and associated control valve connected in circuit with pump means in accordance with the principles of the present invention;
FIG. 3 is a sectioned view of a control valve for use in the drive system shown in FIG. 1 all in accordance with the present invention, the section being taken along a radial plane extending parallel to the axis of rotation of the valve unit;
FIG. 4 is a sectioned view of the valve assembly of FIG. 3, the section being taken along line 4--4 thereof;
FIG. 5 is an enlarged fragmentary section view of the cam member forming a part of the valve assembly of FIG. 3;
FIG. 6 is a transverse section view of the valve assembly of FIG. 3 showing the stop arrangements incorporated therein, the section being taken along line 5--5 thereof; and
FIG. 7 is a block diagram of the control circuit used to operate the stepping motor which operates to drive the control valve shown in FIG. 3, all in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and in particular to FIG. 1, there is shown an overland conveyor system 10 which includes a rather long conveyor belt 12 movably supported on a plurality of roller means 14 and including a plurality of driving means 16 spaced along the length of the conveyor system. As shown, each of the drive means includes a motor means 18 such as for example an internal combustion engine or electric motor which is operatively connected to a clutch unit 20 which operates to selectively transmit the driving forces from the motor means 18 to the conveyor belt 12. Such conveyor systems may range in length from several hundred feet to several miles depending on the particular application.
Clutch units 20 are preferably of the oil shear type such as disclosed in U.S. Pat. No. 3,696,898, issued Oct. 10, 1972 and U.S. Pat. No. 4,171,038, issued Oct. 16, 1979 and assigned to the assignee of the present invention, the disclosures of which are hereby incorporated by reference. Such clutch units comprise a plurality of alternating discs and plates, the discs being secured for rotation with one of the input and output shafts of the clutch and the plates being secured for rotation with the other of said input and output shafts. An actuating cylinder is normally provided to which pressurized fluid such as an oil for example is supplied which operates to move the alternating discs and plates into mutual operative relationship whereby the driving force of the motor means may be transmitted to the output shaft so as to drive the apparatus connected thereto. The construction and operation of the clutch is described more fully in the above referenced patent.
In order to control actuation of clutch unit 20 and hence provide a smooth "soft" start of the conveyor system or other apparatus being driven, pump means 22 are provided as shown diagrammatically in FIG. 2 which are operative to provide a supply of pressurized fluid from a reservoir (not shown) to the clutch unit 20 via conduit 24 so as to enable actuation of the clutch unit 20. In operation, the pump means may be continuously operated so as to provide lubrication and cooling fluid to the clutch with only a portion of the output being used for control purposes. Alternatively, separate pump means may be provided for control purposes. In either event, the pump means is first started so as to create a source of pressurized fluid and a pressure relief control valve assembly 26 is provided being connected to conduit 24 by conduit 28 and which operates to allow fluid output from the pump means 22 to be directed therethrough back to a reservoir when in a fully open position so as to substantially prevent any actuating pressure being applied to the clutch unit 20. As the valve assembly 26 closes, fluid flow therethrough will be progressively restricted thereby resulting in increasing actuating fluid pressure being applied to the clutch unit 20. As this fluid actuating pressure is progressively increased, the plates and discs of the clutch unit will be progressively moved axially into torque transmitting relationship with relative rotation therebetween being progressively decreased until such time as the output shaft is being rotated at full operating speed.
Referring now to FIGS. 3 through 6, a pressure relief control valve assembly 26 in accordance with the present invention is illustrated and includes an elongated generally rectangular shaped housing 30 having a central bore 32 extending longitudinally therethrough which includes enlarged diameter portions 34 and 36 at opposite ends 38 and 40 thereof respectively. An inlet opening 42 is provided in the upper sidewall 44 which opens radially inwardly into bore 32 and which is adapted to have a fluid supply line connected thereto such as conduit 28 shown in FIG. 2. A pair of radially extending outlet openings 44 and 46 are also provided on the lower sidewall 48 of housing 30 being substantially equally longitudinally spaced in opposite directions from inlet opening 42. Outlet openings 44 and 46 each open into a manifolding cavity 50 formed in the lower sidewall 48 of housing 30. A plate 52 is secured by suitable fasteners 53 to the lower sidewall 48 of housing 30 which in part defines and encloses manifolding cavity 50 and has a single outlet opening 54 provided therein which is adapted to have a fluid supply line connected thereto for returning actuating fluid to the reservoir.
An elongated rotatable valve core member 56 is movably positioned within longitudinally extending bore 32 and includes an enlarged diameter flange portion 58 adjacent the outer end 60 which engages a radially extending flange portion 62 interconnecting bore 32 and enlarged diameter portion 34 so as to axially position valve core member 56 with respect to housing 30. A retaining plate 64 is secured by suitable fasteners 65 to the outer end 38 of housing 30 and has a portion 66 extending into enlarged diameter portion 34 of bore 32 and into engagement with the outer surface 68 of flange 58 so as to securely restrain valve core member against axial movement. An annular groove 70 is also provided on portion 66 within which suitable sealing means 72 such as an O-ring is positioned which sealingly engages the sidewall of enlarged diameter portion 34 thereby preventing leakage of fluid therefrom. An opening 74 is also provided in housing 30 extending radially outwardly from the lower part of enlarged diameter portion 34 and opening into cavity 50 which operates to allow actuating fluid accumulating within enlarged diameter portion 34 to be returned to the reservoir.
Valve core member 56 also has a pair of axially spaced bearing journals 76 and 78 adjacent opposite ends thereof which engage the sidewalls of the longitudinally extending bore 32 so as to rotatably support valve core member therein. A cam lobe 80 is also provided on valve core member 56 being positioned approximately midway between journals 76 and 78 and in radial alignment with inlet opening 42. As best seen with reference to FIGS. 4 and 5, cam lobe 80 has a notched portion 82 on the circumference thereof which is positionable in alignment with inlet opening 42 so as to allow substantially unrestricted full fluid flow therethrough when valve assembly 26 is in a fully open position. Cam lobe 80 also has a substantially uniform rise or increasing radius circumferential surface portion 84 extending in a counterclockwise direction from notch 82 as shown in FIG. 5 and through approximately 270° of rotation as measured from approximately the center line of notch 82 with the remaining circumferential surface portion 86 thereof being of substantially constant radius. In the embodiment shown, the total cam rise is approximately 0.09 of an inch although it should be noted that both the contour and total rise may be varied so as to provide any desired acceleration curve. For example, should an extremely gradual initial startup be desired, the cam lobe could be provided with a first more gentle rise portion followed by a steeper rise portion which would allow the driven equipment to be more rapidly accelerated after initial movement had begun. Other variations suitable for the particular application may easily be provided by selecting an appropriate cam lobe contour. The maximum radius circumferential surface portion 86 or cam lobe 82 is such that when valve core member 56 is rotated so as to position the maximum radius circumferential surface portion 86 in alignment with inlet opening 42, fluid flow into valve assembly 26 will be substantially eliminated. Suitable sealing means 88 are also positioned within enlarged diameter portion 36 through which end portion 90 of valve core member 56 extends outwardly of housing 30. Also, in order to prevent accumulation of fluid between journal 78 and sealing means 88, an opening 92 is provided extending radially outwardly from bore 32 and opening into manifolding cavity 50 so as to enable fluid to be returned to the reservoir.
As shown in FIG. 3, valve housing 30 is supportingly secured by means of a plurality of fastening means 93 to a coupling housing 94 which in turn is supportingly secured to a control housing 96. A stepping motor 98 and associated control circuitry described in greater detail below are disposed within control housing 96 with stepping motor 98 having a drive shaft 100 extending outwardly therefrom through opening 102 provided in sidewall portion 104 and into coupling housing 94. End portion 90 of valve core member 56 also projects into coupling housing 94 through an opening 106 provided in sidewall 108 thereof and is positioned in axial alignment with stepping motor drive shaft 100. Suitable coupling means 110 are provided for drivingly connecting end portion 90 of valve core member 56 to drive shaft 100 and includes a first portion 112 secured to end portion 90 and a second portion 114 secured to drive shaft 100. Coupling means 110 will preferably be of the type which utilizes a suitably resilient rubber or elastomeric composition bushing 111 positioned between overlapping axially extending arm segments provided on first and second portions 112 and 114 respectively. Such couplings are readily commercially available and hence further description thereof is believed unnecessary.
As best seen with reference to FIGS. 3 and 6, first portion 112 of coupling means 110 is provided with a radially outwardly extending arm 116 which is adapted to engage a stop member 118 projecting into the interior of coupling housing in substantially parallel spaced relationship to end portion 90 of valve core member 56 so as to limit the rotational movement of valve core member. In operation, arm 116 will be positioned relative to cam lobe 80 so as to position notch 82 in alignment with inlet opening 42 when arm 116 engages stop member 118 in a counterclockwise direction of rotation as shown in FIG. 6 and to position maximum radius circumferential surface portion 86 in alignment with inlet opening 42 when arm 116 engages stop member 118 in the opposite direction of rotation. The provision of rubber or elastomeric bushing 111 within coupling means 110 will operate to insulate stepping motor 98 from the shock encountered when arm 116 is driven against stop member 118.
Stepping motor 98 will preferably have a relatively large number of steps per revolution; on the order of 200 and has a relatively low torque output sufficient to rotate valve core member 56 but yet small enough to avoid any damage resulting from rotation against stop member.
A control circuit 120, as illustrated in block diagram in FIG. 7, is provided for controlling the operation of stepping motor 98 and hence pressure relief control valve assembly 26. Control circuit 120 includes both forward and reverse drive means 122 and 124 connected to stepping motor 98 which when actuated are operative to provide stepping pulses to drive stepping motor 98 in either clockwise (forward) or counterclockwise (reverse) directions. Circuit reset means 126 are provided which upon energization will operate to activate reverse drive means 124 so as to sequence stepping motor 98 through a full series of steps in a counterclockwise direction to insure valve core member 56 is positioned in the fully open or full bypass mode with the notch portion 82 of cam lobe 80 positioned in alignment with inlet opening 42 in valve housing 30 so as to thereby insure that no actuating fluid pressure is applied to the clutch unit 20.
When valve core member 56 is in this position, substantially the entire fluid output of pump means 22 will be pumped from a reservoir (not shown) through conduits 24 and 28 into valve inlet opening 42 across the valve core member 56 on both sides of cam lobe 80 through the two outlets 44 and 46 into manifolding cavity 50 and outlet opening 54 into a conduit which will return the fluid to the reservoir. Because notch portion 82 on cam lobe 80 of the valve core member 56 is positioned in alignment with inlet opening 42, fluid flow therethrough will be substantially unrestricted and substantially no actuating pressure will be applied to the clutch unit. It should also be noted that because of the provision of two generally parallel fluid flow paths around opposite axial sides of cam lobe 80 of valve core member 56 any axially directed forces exerted on the valve core member 56 from the fluid flow which could result in binding thereof so as to prevent or inhibit rotation of valve core member 56 are substantially balanced.
Once this reset operation has been completed and the location of valve core member 56 relative to the control circuit sequencing has been verified, low speed clock means 128 is actuated and operates to provide a signal to the forward drive means 122 so as to thereby begin advancing the stepping motor 98 in a forward direction which in turn will operate to begin moving the valve core member 56 out of the fully open position. During the initial movement of notch 82 on cam lobe 80 of valve core member 56 out of alignment with the inlet opening 42 the rate of increase of actuating fluid pressure applied to the clutch will be relatively high because relatively slight movement of the valve core member 56 will create a significant increase in the restriction of the inlet opening 42 thereby reducing the volume of fluid flowing through the pressure relief control valve 26.
Low speed clock means 128 will continue to signal the forward drive means 122 to provide driving pulses to the stepping motor 98 thereby further progressively closing pressure relief control valve 26 and increasing the actuating pressure applied to the clutch unit 20 until such time as the pressure sensing means 130 connected in conduit 24 signals pressure set means 132 that a predetermined actuating fluid pressure has been applied to clutch unit 20. This predetermined pressure may be set at any desired level but preferably will be at a pressure corresponding at least to a valve core member 56 position in which notch 82 provided on cam lobe 80 has been moved completely out of the area of the inlet opening 42. Thereafter, pressure set means 132 will deactivate low speed clock means 128 and activate a high speed clock means 134 which will continue to drive stepping motor 98 in a forward direction until the pressure relief control valve means 26 is moved into a fully closed position and full operating pressure is applied to the clutch unit 20. When full actuating pressure is applied to clutch unit 20 the alternating discs and plates will both be rotating at substantially the same speed so as to transmit the full driving power of the motor means to the driven apparatus.
As shown, the output of the high speed clock means 134 is also connected to the reverse drive means 124 via an inverter 136. Inverter 136 is incorporated in the circuitry because both forward and reverse drive means 122 and 124 are responsive to only positive gating signals. Thus, when it is desired to open pressure relief control valve 26, high speed clock means 134 will be activated to provide a series of negative pulses which will be supplied to both the forward and reverse drive means 122 and 124. However, because the polarity of the negative pulse will be changed to positive by inverter 136, only the reverse drive means 124 will be actuated so as to operate stepping motor 98 in a reverse or counterclockwise direction thereby causing the pressure relief control valve 26 to move sequentially from a fully closed position toward a fully open position resulting in increasing fluid flow therethrough and a decrease in actuating fluid pressure applied to the clutch unit 20.
The control system of the present invention is also provided with safety override means operative to abort a startup of the driven apparatus in the event of abnormal conditions such as may occur in the event the apparatus to be driven is jammed or overloaded.
The safety override means includes a first circuit means adapted to abort a startup in the event there is no rotational movement of the clutch unit output shaft after stepping motor 98 has advanced a predetermined number of steps. This circuit includes speed sensor means 138 associated with the output shaft of the clutch unit 20 which senses rotational movement thereof in response to which a signal is sent to a countercircuit means 140. Counter means 140 also receives the same pulses from the forward drive 122 as are being transmitted to the stepping motor 98. In the event counter means 140 has not received any signal from the speed sensor means 138 after the forward drive 122 has advanced the stepping motor 98 through a predetermined number of steps, counter means 140 will actuate the reverse drive 124 so as to pulse stepping motor 98 back to the start position in which the pressure relief control valve 26 is in a fully open position and substantially no actuating fluid pressure is being applied to clutch unit 20. If desired, counter means 140 may also operate to activate alarm means on a central remotely located annunciator panel so that the abnormality may be investigated and repairs effected.
The safety override means also includes circuitry operative to abort a startup in the event the driven apparatus is not accelerated to full operating speed within a predetermined time period such as may occur if the apparatus is overloaded for example. This circuitry includes full speed set means 142 which also receives a speed responsive signal from speed sensor means 138 which is compared to a predetermined full speed setting. If the signal from speed sensor means 138 fails to indicate that the apparatus has achieved full operating speed within a predetermined time period, full speed set means 142 will actuate reverse drive means 124 so as to pulse stepping motor 98 in a counterclockwise direction thereby moving the pressure relief control valve 26 into a fully open position and relieving the actuating fluid pressure being applied to clutch unit 20 so as to prevent possible damage to the clutch or other associated drive system components. The full speed set means 142 may also be tied into an alarm system whereby the need for corrective action may be signaled.
In operation, the pressure relief control valve assembly 26 and the associated control circuitry 120 will operate to enable clutch unit 20 to be actuated in such a manner as to provide a relatively "soft" start yet still allow relatively rapid engagement of the clutch plates and discs so as to minimize slippage and hence wear and frictional heating thereof. This drive system of the present invention is thus particularly well suited for a number of applications in which very large loads are encountered during startup such as for example conveyor systems. Additionally, the pressure relief control valve 26 of the present invention is particularly suited for use in areas of high dust or dirt contaminations in which the pressure actuating fluid may become contaminated therewith. Because the present pressure relief control valve utilizes a relatively large orifice plus the fact that it is designed to be driven in incremental discrete steps, it has been found to be substantially less susceptible to clogging or plugging as a result of highly contaminated fluid. Further, even when such clogging or plugging does occur such as during prolonged periods of operation with the valve in the fully closed position, the initial stepping motion of the valve toward the open position has resulted in rapid clearing of the contaminant accumulation thus providing precise reliable control.
Also, both the pressure relief control valve and the associated control circuitry may be easily fabricated at relatively low cost and yet provide a highly reliable and durable clutch control system which may be easily utilized in both single and multiple drive systems. For example, in overland conveyor systems which may extend for several miles and which may have a number of belt drive means spaced along the length thereof, it is necessary to sequence the startup of the drives so as to assure proper belt tensioning. This may be easily accomplished with the present control system by merely delaying the pulses to the respective stepping motors driving the pressure relief control valves of successive clutches by any number of counts necessary to enable proper belt tensioning. Additionally, the safety override means provides integral protection within the clutch control system which will abort startups and shut down the system under abnormal conditions so as to thereby prevent excessive slipping of the clutch unit which may result in premature failure thereof as well as other possible damage to the driven or driving equipment associated therewith.
While it will be apparent that the preferred embodiment of the invention disclosed is well calculated to provide the advantages and features above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.
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An improved heavy duty motor clutch drive system is disclosed which includes a motor adapted to be drivingly connected to apparatus to be driven by means of a clutch unit of the oil shear type which may be selectively actuated by application of fluid pressure. Improved electrically actuated control valve means are provided for controlling the application of actuating fluid pressure to the clutch unit and includes associated control circuitry for operating the control valve so as to accelerate the driven apparatus in a predetermined manner. Additionally, in some applications a plurality of such drive systems may be utilized to drive a common apparatus in which case the clutch actuating controls may be interconnected so as to provide progressive predetermined delay actuation of the various clutch units. Safety override means are also incorporated into the control circuitry which are designed to deactuate the clutch unit so as to disconnect the motor from the driven apparatus in response to abnormal operating conditions.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation-in-part of U.S. patent application Ser. No. 10/014,164, filed on Oct. 26, 2001 now abandoned, which claims the benefit of U.S. provisional application Ser. No. 60/243,526, filed on Oct. 26, 2000, the teachings of which are incorporated herein by reference.
FIELD OF INVENTION
The present invention relates to ultra-high vacuum systems and, specifically, to a system for the insertion of components on a reduced thickness flange between two standard thickness flanges.
BACKGROUND OF THE INVENTION
Vacuum systems find wide applications in research, education, product development, and production. Typical systems comprise independent and interchangeable components. Such components may include testing chambers, pumps, gauges, valves, specimen manipulators, testing apparatus, radiation sources, particle detectors, heating and cooling systems, and other components known in the industry.
Processes or experiments that require high or ultra-high vacuum (UHV) currently employ all metal vacuum joints. A typical flange 20 for an all-metal joint is illustrated in FIG. 1 . Such a joint is comprised of at least two flanges 20 , 24 illustrated in FIG. 2 . Each of the flanges 20 , 24 includes an annular recess 26 , 28 and an annular knife edge 30 , 32 . The flanges 20 , 24 are configured for mating using a soft, metallic gasket 34 (e.g. a copper gasket). The opposing knife edges 30 , 32 are pressed into the gasket 34 when the flanges 20 , 24 are compressed together by tightening bolts 38 . The knife edges 30 , 32 in combination with the gasket 34 form a UHV seal.
The force of the tightened bolts 38 is transferred to the gasket 34 through the thickness of the flanges 20 , 24 . The bolt holes 36 are disposed on a diameter that is outside that of the knife edge 30 , 32 . If the standard flange 20 , 24 is not of appropriate thickness, the flanges 20 , 24 may deform as depicted in FIGS. 3 and 4 . The deformed flange 25 A in FIG. 3 is considered a dish-shaped deformation and results from the flange 25 A bowing around the perimeter of the gasket. The deformed flange 25 B in FIG. 4 is a wave-like deformation and results from deflection of the flange 25 B between bolts in the all-metal joint. The bowing of the flange 25 A occurs due to the moment arm between the knife edge 30 , 32 and the bolt 38 . In the case of a deflection or deformation, such as those illustrated in FIGS. 3 and 4 , the seal may leak if the force placed on the gasket 34 between the adjacent bolts 38 is less than the force required to press the knife edges 30 , 32 sufficiently into the gasket 34 to form a seal. Only an appropriate thickness of the flange provides adequate resistance to deformation in this situation.
Thus, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.
SUMMARY OF THE INVENTION
Embodiments of the present invention provide a system and method for providing a thin flange.
Briefly described, in architecture, one embodiment of the system, among others, can be implemented as follows. A thin flange, for use with a vacuum system, includes a member having a diameter and a thickness. The member has a first face having a first sealing surface. The member has a second face opposed and substantially parallel to the first face. The second face has a second sealing surface. The thickness of the member is less than previously attained. In some designs, the thickness of the member is less than 0.28 inches. In other designs, the thickness of the member is less than fifteen percent of the diameter of the member.
Other systems, methods, and advantages of the present invention will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present invention, and be protected by the accompanying claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments of the invention are set forth in the following description and shown in the drawings, wherein:
FIG. 1 is a perspective view of a prior art flange used for an all metal joint.
FIG. 2 is a partial cross-sectional view of a prior art seal.
FIG. 3 is a cutaway view of a prior art flange with dish-shaped deformation.
FIG. 4 is a perspective view of a prior art flange with wave-like deformation.
FIG. 5 is a graph illustrating the thickness of normal double-sided flanges, relative to diameter, as compared to the thickness of the thin flanges of the present invention and encapsulated within the graph is an image of a flange, illustrating the thickness and diameter measurements of the flange.
FIG. 6 is a perspective view of a first exemplary embodiment of a thin flange consistent with the present invention.
FIG. 7 is a sectional view of the first exemplary embodiment of the thin flange consistent with the present invention.
FIGS. 8 through 8C illustrate an application of the first exemplary embodiment of the thin flange consistent with the present invention.
FIG. 9 is a perspective view of a second exemplary embodiment of the thin flange consistent with the present invention.
FIG. 9 a is a cross-sectional view of the second exemplary embodiment of the thin flange, in accordance with FIG. 9 .
FIG. 10 is a perspective view of a third exemplary embodiment of the thin flange consistent with the present invention.
DETAILED DESCRIPTION
Referring to FIGS. 6 through 10 , various exemplary embodiments of double-sided thin flanges consistent with the present invention are illustrated. It should be understood that the term “thin flange”, as used herein, is not so much an absolute dimensional characterization as it is a convenient designation, indicating that the flange is not required to be thick enough to withstand the asymmetric stress and deflection imposed by the clamping bolts. The thickness of the thin flange is not needed to withstand the asymmetric stress and deflection imposed by the clamping bolts because the thin flange receives symmetric force from flanges on opposite sides of the thin flange through gaskets crushed between the thin flange and each of the other flanges. The thickness of the thin flange is rather determined primarily by the thickness required to provide the instantly desired mounting characteristics or features—i.e., mounting grooves, threaded bores, feed-throughs, etc., as discussed in the following description of the invention.
The present invention is based upon the innovative idea that double-sided flanges, which are generally intended to be sandwiched between two standard thickness flanges, do not need to be thick enough to withstand the stress and deflection imposed by the clamping bolts. The primary force applied to the standard thickness flanges is applied asymmetrically at the interspersed bolt holes. Therefore, as previously described, the standard thickness flanges must be strong enough and, thereby, thick enough to avoid deformation of the standard thickness flange due to the uneven forces applied at the area around the bolt holes and the area of the standard thickness flange between consecutive bolt holes. The thin flanges of the present invention, however, do not receive a primary force at the bolt hole location because, in part, the bolts do not attach to the thin flange and therefore, do not apply any force directly to the thin flange. Instead, the force applied by tightening the bolts is communicated directly to the standard thickness flanges and the standard thickness flanges apply symmetric compressive force directly to the gaskets, which apply symmetric compressive force to the thin flange. Because the force applied from the standard thickness flanges, through the gaskets, to the thin flange is spread substantially equally across a sealing surface of each of the standard thickness flanges, the thin flanges do not need to be made thick to avoid deformation from asymmetric forces.
FIG. 5 is a graph that further illustrates the improvements of the present invention. The graph plots the minimum thickness available for industry standard flanges and for the thin flanges of the present invention against the corresponding diameter of the flanges, with the thickness T and diameter D illustrated in an image of a flange 40 within the graph of FIG. 5 . The graph shows that a typical line of industry standard flanges has an increase in thickness as the diameter of the industry standard flanges increase. One of the motivations for this increase is durability, specifically the ability to avoid deformation. The present invention is based on the finding that flanges do not need to be made thicker to be durable. For all industry standard flange diameters shown, the present invention is capable of maintaining a thickness of 0.155 inches, as shown on the graph, which is presently the thickness required to maintain the two sealing surfaces. Should a sealing surface be designed that requires less thickness than those currently known, the present invention would be capable of maintaining a thickness below 0.155.
The present invention is also capable of maintaining any thickness between 0.155 inches and those thicknesses previously available. The present invention is capable of maintaining a thickness of 0.28 inches or below for any diameter double-sided flange. The present invention is capable of maintaining a thickness that is less than approximately 6.5% of the diameter of the double-sided flange. For double-sided flanges with a diameter of less than five inches, the present invention is capable of maintaining a thickness that is less than approximately 15% of the diameter of the double-sided flange. For double-sided flanges with a diameter of greater than five inches, the present invention is capable of maintaining a thickness of 0.75 inches or less.
FIGS. 6 through 8C show details of a first exemplary embodiment of a thin flange 40 having a first face 41 on which is located a first sealing surface 42 to crush a metallic gasket 44 A against a standard thickness flange 48 for forming an all-metal joint. The thin flange 40 further features second face 49 on which is located a second sealing surface 50 to crush a metallic gasket 44 B against a standard thickness flange 54 for forming the all-metal joint. A plurality of bolt holes 46 are located outside of a perimeter of the sealing surfaces 42 , 50 to provide an access way for securing the standard thickness flanges 48 , 54 with the bolts 45 . The bolt holes 46 provide alignment of the thin flange 40 relative to the standard thickness flanges 48 , 54 prior to sealing. Once the seal is formed, by tightening the bolts 45 and crushing the gaskets 44 A, 44 B, no support is provided to the thin flange 40 by the bolts 45 .
FIG. 6 is a prospective view of the first exemplary embodiment of the present invention. FIG. 7 is a cross-sectional view of the thin flange 40 shown in FIG. 6 . This cross-section shows the details of the sealing surfaces 42 , 50 , which are knife edges in this embodiment. Consistent with the present invention, internal vacuum components may be mounted using equipment-mounting grooves 52 . These specific equipment mounting grooves 52 permit the mounting of internal vacuum system components (not shown). As illustrated, the equipment-mounting grooves 52 are disposed in a region of the thin flange 40 located within the perimeter of the sealing surfaces 42 , 50 . Accordingly, components may be mounted extending out of the confines of the thin flange 40 . Consistent with this configuration, components may be mounted to the vacuum system over a shorter distance than previously possible because the thin flange 40 eliminates the need for a tube or standard fittings or an independent structurally thick double-sided flange. Not only does the decrease in length required to mount components make the system more convenient in space-limited applications, the decrease in length also increases the conductance of the vacuum system.
Referring to FIG. 8 and FIG. 8C , which is a partially exploded view of FIG. 8 , there is shown an exemplary thin flange 40 mounted between two standard thickness flanges 48 , 54 . The two standard thickness flanges 48 , 54 are sealed against respective sides of the thin flange 40 by crushed gaskets 44 A, 44 B. When the system is sealed, by tightening the bolts 45 , the force exerted on the standard thickness flanges 48 , 54 by the bolts 45 is effectively transferred by the rigid body of the standard thickness flanges 48 , 54 to their respective sealing surfaces 42 , 50 which substantially simultaneously crushes both metallic gaskets 44 A, 44 B. This, in turn, causes the crushed gaskets 44 A, 44 B to bear symmetrically against the inner side of the thin flange 40 . Accordingly, the thin flange 40 experiences only symmetrical compressive loading about its thickness. The bolt holes 46 of the thin flange 40 are under zero load. Furthermore, the thin flange 40 is not subject to any bending loads, as may be the case with the standard thickness flanges 48 , 54 . This allows the thin flange 40 to be of a minimal thickness, only sufficient to resist the compressive forces and contain the sealing surfaces 42 , 50 . Accordingly, a membrane, window, or small aperture can be mounted within an opening 47 formed in the thin flange 40 . Alternatively, the thin flange 40 could be constructed without an opening 47 .
Turning to FIG. 9 and FIG. 9A , there is illustrated a perspective view and a cross-sectional view of a second exemplary embodiment of the thin flange 140 . The second exemplary thin flange 140 is configured without bolt holes. This embodiment is based on the realization that thin flanges are not supported by bolts and, therefore, can be constructed without bolt holes as long as the thin flange 140 can be mounted between two standard thickness flanges without interfering with the bolts for the standard thickness flanges. The thin flange 140 , according to this embodiment, allows for arbitrary radial alignment to the mating system. The greater flexibility in radial alignment of the thin flange 140 is capable because placement of the thin flange 140 relative to the standard thickness flanges (not shown) is not restricted by the need to align bolt holes in the thin flange 140 with the bolt holes in the standard thickness flanges. As shown in FIG. 9A , little is needed beyond a sealing surface 142 , 150 on each face 141 , 149 of the thin flange 140 to create the second exemplary embodiment of the present invention. The thin flange 140 consistent with this exemplary embodiment is especially beneficial when an instrument or apparatus mounted to the thin flange 140 must be precisely aligned either within the vacuum system, or relative to another instrument or apparatus. The embodiment of the thin flange 140 shown in FIGS. 9 and 9A is designed to have a small enough outer diameter so as to avoid interfering with bolts of standard thickness flanges. Other variations of the thin flange 140 are also contemplated that avoid interfering with bolts of standard thickness flanges without minimizing the outer diameter of the thin flange 140 and without incorporating industry standard bolt holes.
FIG. 10 illustrates in isometric view a third exemplary embodiment of a thin flange 240 consistent with the present invention. According to the third exemplary embodiment, the thin flange 240 comprises a series of mounting holes 262 disposed about an inner web 256 , inside the perimeter of the sealing surfaces 242 (only one sealing surface is shown) of the flange 240 . The mounting holes 262 may advantageously be configured to mount any variety of apparatus inside of the vacuum system. Accordingly, the mounting holes 262 may be arranged in a pattern that is standard to a variety of equipment, or the mounting holes 262 may be specially configured for individual pieces of apparatus. By employing a thin flange 240 as disclosed herein it is possible to align vacuum components and mating interior system components with a high level of dimensional precision.
In each of the above-described embodiments, the thin flange preferably is formed from a single unitary member. By machining the thin flange, including both of the sealing surfaces, from a single member it is possible to achieve very high tolerances. Additionally, it is possible to achieve a superior surface finish on the thin flange. This characteristic lends itself to higher conductance and greater cleanliness of the vacuum system, as well as accurate flange face parallelism.
Consistent with the above teachings, a thin flange of the present invention may be beneficially employed for mounting equipment within the vacuum system itself, as well as for an interface connecting items within the vacuum system to the exterior of the vacuum system. An exemplary application may be to conveniently provide an electrical feed-through for powering an apparatus inside the vacuum system while still maintaining the “vacuum tight” integrity of the system. Similarly, the inner web of the thin flange may be equipped with a valve, therein providing direct communication with interior of the vacuum system without decreasing the conductance of the system, which does result from typical valve mounting systems disposed on a couple or tube.
Further, the thin flange can mount an interior component, such as an electron gun, as well as provide an electrical feed-through. This is an improvement over having the electrical connections on a separate port of the vacuum chamber, as is conventionally the case. The advantage is that the connection does not need to be done at the location of the vacuum system since the component can be mounted within the thin flange and the electrical connections may be made as an independent subsystem. Should the component need to be removed from the vacuum system, the connection would not need to be disassembled and subsequently reassembled when the component was remounted. This configuration of components saves time, and may reduce the number of ports required on a main chamber of a vacuum system.
Further embodiments of the coupling flange obviously include different lengths, different industry standard flange sizes, different flange geometries, such as oval, rectangular, or other planar shape, and different interior mounting arrangements. On slightly thicker versions of the flange, radial ports may be added to increase access to internal components. The thin flanges could also be stacked, with the limit only being the twist up and stretch of the set of bolts.
In consideration of the various above-described embodiments and applications consistent with the present invention, it will be readily appreciated that the thin flanges consistent with the present invention may advantageously be employed in a stacked manner. Consistent with this, a plurality of thin flanges may be disposed between two standard thickness flanges, thereby providing a variety of mounting features, feed-throughs, valves, etc., while requiring only one port on the vacuum system. Because each of the thin flanges consistent with the present invention contain two sealing surfaces, any number of thin flanges may be coaxially disposed, with each pair having a soft metallic gasket disposed therebetween. Furthermore, as in the case of a single thin flange disposed between two standard thickness flanges, each of the thin flanges in the above described “stack” will experience only symmetrical forces, generally only compressive in nature, and therefore will not be subject to distortion or deflection resulting from the clamping bolts.
It should be emphasized that the above-described embodiments of the present invention, are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the invention. Many variations and modifications may be made to the above-described embodiment of the invention without departing substantially from the spirit and principles of the invention. All such modifications and variations are intended to be included herein within the scope of this disclosure and the present invention and protected by the following claims.
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A thin flange, for use with a vacuum system, includes a member having a diameter and a thickness. The member has a first face having a first sealing surface. The member has a second face opposed and substantially parallel to the first face. The second face has a second sealing surface. The thickness of the member is less than previously attained. In some designs, the thickness of the member is less than 0.28 inches.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a fixing device for use in image forming apparatus such as copying apparatus, laser printers and the like.
2. Description of the Related Art
Conventionally, fixing devices for image forming apparatus are generally known and have the capacity to fuse and fix a toner image as a copy sheet bearing an toner image in an unfixed state passes between a pair of pressure and heating rollers. Control circuits for maintaining the surface temperatures of the aforesaid pair of fixing rollers at predetermined temperatures generally compare the temperature detection signals emitted from temperature detection sensors such as thermistors and the like disposed so as to be in contact with the roller surface with predetermined reference temperature signals used for temperature regulation. The surface temperature of the roller is controlled by turning on an electrical current which is supplied to a heater provided within the roller when the temperature detection signal is less than the reference temperature signal, and by turning off the electrical current flowing to the heater within the roller when the temperature detection signal is greater than the reference temperature signal.
In the aforesaid arrangement, however, a certain amount of time elapses while the heat emitted from the heater within the roller is transmitted to the surface of the roller and, therefore, some time is required for the thermistor to detect the surface temperature and generate a output corresponding to the detected temperature. Accordingly, in the previously described control method, even if the heater is turned on or off, some time delay is produced until the temperature effect of the heater becomes the actual temperature detection signal to be detected, and the time delay causes greater fluctuation in the roller surface temperature in regulating the temperature.
SUMMARY OF THE INVENTION
A main object of the present invention is to provide a fixing device capable of controlling the surface temperature of the fixing rollers while the fluctuation range of the surface temperature.
A further object of the present invention is to provide a fixing device capable of slowing the speed of temperature elevation or reduction when controlling the surface temperature of the fixing rollers.
These and other objects of the present invention are achieved by providing a fixing device for thermally fusing a toner image on a paper sheet by means of a pair of rollers, the fixing device comprising:
heating means for heating the roller,
detecting means for detecting the temperature of the roller,
signal converting means for overlaying a periodically changing signal on at least one of the temperature detection signal detected by the detecting means and a reference temperature signal which is a standard for roller temperature control,
comparing means for comparing the reference temperature signal and the temperature detection signal overlaid the periodically changing signal by the signal converting means, and
control means for controlling the current supplied to the heating means in accordance with the comparison results of the comparing means.
These and other objects, advantages and features of the invention will become apparent from the following description thereof taken in conjunction with the accompanying drawings which illustrate specific embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following description, like parts are designated by like reference numbers throughout the several drawings.
FIG. 1 briefly shows the construction of the fixing device of the present invention;
FIG. 2 shows the circuit for controlling the temperature regulating operation of the fixing device of the present invention;
FIG. 3 is an illustration showing the principles of temperature regulation of the fixing device of the present invention;
FIG. 4 is a flow chart showing the temperature regulating operation of the fixing device of the present invention; and
FIG. 5 illustrates another example of the principles of temperature regulation of the fixing device of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the present invention are described hereinafter with reference to the accompanying drawings. As shown in FIG. 1, the fixing device of the present embodiment is provided with a heating roller 1 and pressure roller 2 for applying heat to and transporting therebetween a paper sheet bearing a toner image. A heating lamp 3 is provided within the heating roller 1 for heating the roller 1, and a thermistor 4 is disposed so as to be in contact with the surface of the roller 1 to detect the surface temperature of the roller 1. The heating roller 1 rotates with the pressure roller 2 in the arrow direction in the drawing, so as to fix a paper sheet bearing an unfixed toner image formed thereon and being transported from the left side of the drawing and to transport the sheet therebetween toward the right side of the drawing.
FIG. 2 shows the temperature control circuit of the present embodiment of the fixing device. Temperature control is accomplished by means of a microcomputer MC provided with an analog-to-digital (AD) converter. The heating lamp 3 is connected to an alternative current (AC) power unit via the Triac 6 which is triggered through the transformer 7 by signals from the output port PO1. The thermistor 4 is connected in parallel to the resistor R2 and in series to the resistor R1, and the divided voltages are input to the input port A/D1 of the microcomputer MC as temperature detection signals. The reference temperature signals, which are references for temperature regulation, are input to the VREF from the serially connected resistors R3 and R4. The temperature detection signal input to the A/D1 overlays the square wave having uniform amplitude and periodicity within the microcomputer MC and compared with the reference temperature signal input to the VREF, and a signal is output from the output port PO1 in accordance with the comparison results.
The control principles for regulating the surface temperature of the heating roller 1 of the present invention are described hereinafter with reference to FIG. 3. The temperature detection signal A detected by the thermistor 4 becomes the temperature detection signal C by adding the square wave having an amplitude of ΔT (a constant) and a period of 1 [second]. The electric current is controllably turned on and off to the heating lamp 3 by comparing the temperature detection signal C and the reference temperature signal B. More specifically, the surface temperature of the heating roller 1 is elevated by the heating lamp 3, and from the moment the temperature detection signal C intersects the reference temperature signal B at E1 the electric current supplied to the heating lamp 3 is turned off for a time period τ1, and thereafter is turned on for a time period τ2, as shown in FIG. 3(c). The electric current is supplied intermediately between the on state and the off state by repeating the aforesaid control (i.e., τ1+τ2=1 [second]), and the current is completely turned off at El'. After the electric current is turned off, the surface temperature of the roller 1 shifts downwardly, and the current is again turned on to the heating lamp 3 at the moment the temperature detection signal C again intersects the reference temperature signal B at E2 in the drawing. Within the region E2˜E2'the electric current is supplied intermediately between the on state and the off state by repeatedly switching on and off the electric current supplied to the heating lamp 3 in the same manner as within the range El˜E1', then the current is completely turned on.
That is, when the heating lamp 3 is in the on state and the detected temperature approaches a set reference temperature from a lower temperature, the current supplied to the heating lamp 3 is controllably turned on and off for periods of 1 [second], as shown in FIG. 3(c), so as to reduce power consumption and retard the speed at which the temperature is elevated. The heating lamp 3 is turned off after the detected temperature has reached the set reference temperature, whereupon the detected temperature begins to decline. On the other hand, when the heating lamp 3 is in the off state and the detected temperature approaches the set reference temperature from a higher temperature, the current supplied to the heating lamp 3 is controllably turned on and off for periods of 1 [second]so as to increase power consumption and retard the speed at which the temperature declines. After the detected temperature has equalized with the set reference temperature, the heating lamp 3 is turned on and the detected temperature again is elevated.
The timing for switching the electric current supplied to the heating lamp 3 from the on state to the off state, or from the off state to the on state is accelerated by means of the aforementioned control compared to when the square wave is not added to the temperature detection signal A, as shown in FIG. 3(b). Furthermore, the aforesaid switching can be accomplished calmly, with the result that the fluctuation range of the surface temperature of the heating roller 1 is controllably maintained within a narrower range.
The temperature control of the heating roller 1 of the present invention is described hereinafter with reference to the flow chart of FIG. 4. First, in step S1, a check is made to determine whether or not the timer flag is set at [0] or [1]. When the timer flag is set at [0], the routine proceeds to step S3, whereas when said flag is set at [1], the routine proceeds to step S15. When the timer flag is set at [0]the timer τ1 is set to count the timer period 1, whereas when the timer flag is set at [1]the timer τ2 is set to count the time period τ2, and the timer flag is changed to either [0]or [1]each time the period of the respective timers has elapsed. In step S3, a check is made to determine whether or not the "Ta-ΔT<Tb." In the aforesaid expression, Ta is the temperature detected by the thermistor 4 and is expressed by the temperature detection signal A in FIG. 2(a); Tb is a predetermined reference temperature expressed by the reference temperature signal B in FIG. 2(a). In the aforesaid expression, Ta-ΔT is a value added to the square wave, and is expressed by the temperature detection signal c in FIG. 2(a). When the determination of step S3 is that "Ta-ΔT<Tb" is fulfilled, the heater lamp 3 is turned on in step S5, whereas when said determination is that "Ta-ΔT<Tb" is not fulfilled, said heater lamp 3 is turned off in step S7. Then, in step S9, a check is made to determine whether or not the time period τ1 has elapsed, and if said time has elapsed the timer flag is set at [1](step S11), and the timer τ2 is set (step S13), whereupon the routine returns. If the time period τ1 has not elapsed, the routine returns immediately.
In step S15, a check is made to determine whether or not "Ta+ΔT>Tb." When "Ta+ΔT>Tb" is true, the heating lamp 3 is turned on (step S17), whereas when "Ta+AT>Tb is not true, the heating lamp 3 is turned off (step S19). Then, in step S21, a check is made to determine whether or not the timer period τ2 has elapsed. When the period τ2 has elapsed, the timer flag is set at [0] (step S23), the timer τ1 is set (step S25) and the routine returns. On the other hand, when the time period τ2 has not elapsed, the routine returns immediately.
Although the present embodiment has been described in terms of a square wave having constant amplitude and periodicity added to a temperature detection signal, it is to be noted that the same effect may be accomplished by a periodically variable oscillatory wave signal added to the predetermined reference temperature signal. In such a case, for example, an alternative signal changing levels stepwisely (in this case a three-step variable signal) is added to the predetermined reference temperature signal B and is modified to an amplitude-bearing set temperature signal D to achieve the same control as described in the aforesaid embodiment, as shown in FIG. 5(a), and the condition of the electric current supplied to the heating lamp 3 can be more finely controlled, as shown in FIG. 5(b), to accomplish switching the current from the on state to the off state more calmly. Furthermore, the same effect may be accomplished even when a periodic amplitude wave is added to both the temperature detection signal and the predetermined reference temperature signal. In such an instance, the periods must be dissimilar.
While a heating lamp was used as the heater 3 provided within the heating roller 1 in the aforesaid embodiment, it is to be understood that a resistance heating element may alternatively be used. And, while a square wave was used as the oscillatory wave added to the temperature detection signal and the predetermined reference temperature signal in the present embodiment, it should be noted that delta waves, sine waves and the like may also be used.
Although the present invention has been fully described by way of examples with reference to the accompanying drawings, it is to be noted that various changes and modifications will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention, they should be construed as being included therein.
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A fixing device of an image forming apparatus for fixing a toner image on a paper by a heating roller and a pressure roller, and having a detector for detecting the temperature of the heating roller. The fixing device controls to supply the electric current to the heating roller intermediately between on state and off state by repeatedly switching on and off the electric current when the difference between the detection temperature signal detected by the detector and a reference temperature signal is within a predetermined value.
In detail, the fixing device overlays a periodically changing signal on at least one of the detection temperature signal and the reference temperature signal by a signal convertor so as to control the current supplied to the heating roller in accordance with the comparison result of the detection temperature signal and the reference temperature signal output from the signal convertor.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of copending International Application No. PCT/DE99/00007, filed Jan. 4, 1999, which designated the United States.
BACKGROUND OF THE INVENTION
[0002] Field of the Invention
[0003] The present invention relates to a tunable antenna having separate radiator parts for tuning to a desired radiation pattern and to a process for manufacturing the antenna.
[0004] In the prior art, the molded interconnect device (“MID”) technology discloses, among other things, that it is possible to manufacture inexpensive antennas for, i.e., mobile telephones or the like. More precisely, a structure capable of radiating or conducting such as, for example, a helix is galvanically applied to a carrier that is generally round.
[0005] Antennas manufactured in such a way are generally narrow-band antennas. Accordingly, it is necessary to tune these antennas to a desired resonant frequency. Such tuning or readjustment has previously been achieved by determining the radiator length of the antenna.
[0006] During manufacture of the above-mentioned antennas, however, unavoidable, slight variations in tolerance are obtained. As a result of the variations in tolerance, the respective resonant frequencies of the individual antennas are not at a stable value but change in accordance with the systematic variations in tolerance existing in the antennas during the manufacture of these antennas. The consequence is that the resonant frequencies of the various antennas manufactured by the same process change towards higher or lower values during the manufacturing process. The effect has a permanent negative effect on the quality of the various antennas.
[0007] In prior art manufacturing processes, the only possibility for compensating for such variations in tolerance lies in readjusting the antennas by changing the length of the radiators; meaning that it is necessary to make changes in or on the tool used itself. However, such changes are extremely complex and very expensive. A further decisive disadvantage of the prior art manufacturing processes also exists in that such changes in or on the tool can always only be carried out for large numbers but not for relatively small numbers or even individual antennas. As a result, it is not possible to compensate for short-term variations in tolerance occurring generally.
SUMMARY OF THE INVENTION
[0008] It is accordingly an object of the invention to provide a tunable antenna having separate radiator parts for tuning to a desired radiation pattern and a process for manufacturing the antenna that overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices and methods of this general type and that can be tuned to a desired radiation pattern with little manufacturing expenditure
[0009] With the foregoing and other objects in view, there is provided, in accordance with the invention, a tunable antenna, including at least first and second separate radiator parts having a couple therebetween and defining a radiation pattern, the couple formed to be changed by at least one of rotation and displacement of the at least first and second radiator parts with respect to one another where a respective degree of at least one of rotation and displacement creates a corresponding change the radiation pattern.
[0010] According to the invention, a tunable antenna is created that has at least first and second separately constructed radiator parts that are coupled to one another. Coupling between the radiator parts can be changed by rotating and/or displacing the radiator parts with respect to one another such that the antenna exhibits a radiation pattern associated with a respective degree of a rotation and/or displacement.
[0011] Accordingly, the antenna of the invention achieves an essential advantage that the antenna can be changed in a simple manner in its effective radiator length by a rotation and/or displacement of the radiator parts. Because the radiation pattern of the antenna is a function of the effective radiator length, the radiation pattern of the antenna can also be changed in a simple manner by rotating and/or displacing the radiator parts with respect to one another. The resonant frequency or, respectively, the resonant frequencies of the antenna represent a measure of the effective radiator length and can be used for assessing the radiation pattern.
[0012] The coupling between the radiator parts can be an electrical coupling, a capacitive coupling, and/or an inductive coupling.
[0013] In accordance with another feature of the invention, there is provided a cap for covering the separate radiator parts.
[0014] In accordance with a further feature of the invention, the first radiator part has a first helix and a conductor part. The first helix has an end, a first longitudinal center axis and extends parallel or inclined to the first longitudinal center axis. The conductor part is disposed at the end. The second radiator part has a second helix and an open turn. The second helix has an end and a second longitudinal center axis. The open turn is disposed at the end and is disposed in a plane extending one of perpendicularly and inclined to the second longitudinal center axis of the helix.
[0015] In accordance with an added feature of the invention, the radiator parts are disposed with respect to one another to align the longitudinal center axes of the helices and such that the conductor part electrically contacts the open turn. At least one of the radiator parts is formed to rotate about a respective longitudinal center axis of the helix.
[0016] In accordance with an additional feature of the invention, the radiator parts are a plurality of first and second radiator parts disposed in an alternating sequence.
[0017] In accordance with yet another feature of the invention, there is provided a third radiator part having a rod, a conductor part, and an open turn. The rod has a longitudinal center axis and first and second ends. The conductor part is disposed at the first end and has a longitudinal center axis aligned with the longitudinal center axis of the rod. The open turn is disposed at the second end and is located in a plane extending perpendicular or inclined to the longitudinal center axis of the rod.
[0018] In accordance with yet a further feature of the invention, the radiator parts are disposed with respect to one another such that the longitudinal center axes of the helices of first and second radiator parts are aligned. The longitudinal center axes of the rod and of the conductor part of a third radiator part extend one of parallel and inclined to the longitudinal center axes of the helices of the first and second radiator parts. The conductor part of the first radiator part electrically contacts the open turn of the third radiator part. The conductor part of the third radiator part electrically contacts the open turn of the second radiator part. At least one of the radiator parts is formed to be rotated about the longitudinal center axes of the helices of the first and second radiator parts.
[0019] In accordance with yet an added feature of the invention, the radiator parts are a plurality of first, second, and third radiator parts disposed such that respective longitudinal center axes of the helices of the first and second radiator parts are aligned. The respective longitudinal center axes of the rod and of the conductor part of the third radiator part extend parallel and/or inclined to the longitudinal center axes of the helices of the first and second radiator parts. A conductor part of one of the radiator parts electrically contacts an open turn of an adjoining conductor part of one of the radiator parts. At least one of the radiator parts is formed to be rotated about the longitudinal center axes of the helices of the radiator parts.
[0020] In accordance with yet an additional feature of the invention, the first radiator part has a first helix and a first plate part. The first helix has an end and a first longitudinal center axis. The plate part is disposed at the end and is disposed in a plane extending perpendicular and/or inclined to the longitudinal center axis of the first helix. The second radiator part has a second helix and a second plate part. The second helix has an end and a second longitudinal center axis. The plate part is disposed at the end of the second helix and is disposed in a plane extending perpendicular and/or inclined to the second longitudinal center axis.
[0021] In accordance with again another feature of the invention, the radiator parts are disposed with respect to one another such that the longitudinal center axes are aligned and the first plate part is opposite the second plate part at a predetermined distance. At least one of the radiator parts is formed to be rotated about the longitudinal center axes such that an area of coverage of the plate parts is changed with a respective degree of rotation.
[0022] In accordance with again a further feature of the invention, the plate parts are disc segments.
[0023] In accordance with again an added feature of the invention, the first radiator part has a first helix. The first helix has a first longitudinal center axis. The second radiator part has a second helix; the second helix has a second longitudinal center axis. The radiator parts are disposed with respect to one another such that the longitudinal center axes are aligned. The radiator parts overlap one another in a direction of the first and second longitudinal center axes and/or are opposite one another at a predetermined distance. At least one of the radiator parts is formed to be displaced along the longitudinal center axes such that an overlap area and/or the distance between the radiator parts is changed with a degree of displacement.
[0024] In accordance with again an additional feature of the invention, the first radiator part has a first helix and a first meander-shaped part. The first helix has a first longitudinal center axis. The second radiator part has a second helix and a second meander-shaped part. The second helix has a second longitudinal center axis. The radiator parts are disposed with respect to one another such that the longitudinal center axes are aligned and the first meander-shaped part contacts the second meander-shaped part. At least one of the radiator parts is formed to be rotated about the longitudinal center axes such that an inductance formed by the meander-shaped parts is changed with a degree of rotation.
[0025] In accordance with still another feature of the invention, at least one of the first and second meander-shaped parts is a radiating part.
[0026] In accordance with still a further feature of the invention, at least first and second radiator parts are applied to respective carriers, and the respective carriers are round and/or angular.
[0027] In accordance with still an added feature of the invention, the radiator parts are manufactured in MID technology.
[0028] In accordance with still an additional feature of the invention, the radiator parts are fixed with respect to one another after being set to a desired radiation pattern.
[0029] In accordance with a further feature of the invention, the helices have identical and/or different pitches, identical and/or different diameters, and equal and/or oppositely directed pitches.
[0030] With the objects of the invention in view, there is also provided a process for manufacturing tunable antennas, including the steps of constructing radiator parts for a respective antenna, coupling the parts to one another to permit the parts to at least one of rotate and displace with respect to one another, the couple being changed by at least one of rotation and displacement of the parts with respect to one another where a respective degree of at least one of rotation and displacement creates a corresponding change of a radiation pattern of the parts, measuring the radiation pattern of the parts; and adjusting the radiation pattern by at least one of rotating and displacing the parts with respect to one another to set a nominal radiation pattern of the respective antenna formed by the parts.
[0031] A process for manufacturing such a tunable antenna exhibits the steps of constructing the radiator parts for a respective antenna and disposing the radiator parts such that they are coupled to one another and can be rotated and/or displaced with respect to one another. For the respective antenna, an actual radiation pattern of the respective antenna is measured, and a radiation pattern of the respective antenna is adjusted by rotating and/or displacing the radiator parts with respect to one another in order to set a nominal radiation pattern of the respective antenna.
[0032] Accordingly, the process of the invention provides the possibility of readjusting, for example, the resonant frequencies of the antennas in a simple manner in the current manufacturing process by measuring the resonant frequency of a respective antenna and rotating and/or displacing the two radiator parts with respect to one another.
[0033] In particular, the process can be configured such that a first arbitrary number of antennas is manufactured by repeating the first two steps an arbitrary number of times and the actual radiation pattern of one or more of the first arbitrary number of manufactured antennas is measured. A second arbitrary number of antennas is manufactured by repeating the first two steps an arbitrary number of times, and a nominal radiation pattern of the antennas of the second arbitrary number is set based on a value that is derived based upon the measured actual radiation pattern of the one or more antennas of the first arbitrary number.
[0034] In accordance with a mode feature of the invention, a cap is placed on the antenna before and/or after adjusting the radiation pattern and/or setting the nominal radiation pattern.
[0035] In accordance with a concomitant mode of the invention, the parts of the antennas are mutually fixed before and/or after adjusting the radiation pattern and/or setting the nominal radiation pattern.
[0036] The invention provides, in a simple manner, the possibility of adjusting the antennas to a particular radiation pattern in the current manufacturing process.
[0037] Other features that are considered as characteristic for the invention are set forth in the appended claims.
[0038] Although the invention is illustrated and described herein as embodied in a tunable antenna having separate radiator parts for tuning to a desired radiation pattern and a process for manufacturing the antenna, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0039] The construction and method of operation of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] [0040]FIG. 1 is a diagrammatic perspective view of a tunable antenna according to a first embodiment of the invention;
[0041] [0041]FIG. 2 is a diagrammatic perspective view of a tunable antenna according to another embodiment of the invention;
[0042] [0042]FIG. 3 is a diagrammatic perspective view of a tunable antenna according to another embodiment of the invention;
[0043] [0043]FIG. 4 is a diagrammatic perspective view of a tunable antenna according to another embodiment of the present invention; and
[0044] [0044]FIG. 5 is a diagrammatic perspective view of a tunable antenna according to another embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0045] In all the figures of the drawing, sub-features and integral parts that correspond to one another bear the same reference symbol in each case.
[0046] Referring now to the figures of the drawings in detail and first, particularly to FIG. 1 thereof, there is shown a diagrammatic representation of a tunable antenna according to the first exemplary embodiment of the present invention.
[0047] As shown in FIG. 1, a first radiator part 1 has a helix 3 and a conductor part 4 . The helix 3 has a longitudinal center axis represented by a dot-dashed line. The conductor part 4 is disposed at one end of the helix 3 such that a non-illustrated longitudinal center axis of the conductor part 4 extends parallel to the longitudinal center axis of the helix 3 .
[0048] A second radiator part 2 also has a helix 5 and an open turn 6 . Helix 5 also has a longitudinal center axis represented by the dot-dashed line. The open turn 6 is disposed at one end of the helix 5 and is located in a plane that extends perpendicularly to the longitudinal center axis of the helix 5 of the second radiator part 2 .
[0049] In the first exemplary embodiment, the first and second radiator parts 1 , 2 are disposed with respect to one another such that the longitudinal center axes of the respective helices 3 , 5 of the first and second radiator parts 1 , 2 are aligned, that is to say, they are located in one line. The conductor part 4 of the first radiator part 1 electrically contacts the open turn 6 of the second radiator part 2 . Furthermore, either the first or the second radiator part 1 , 2 , respectively, can be rotated about the longitudinal center axes of the helices 3 , 5 of the first and second radiator parts 1 , 2 , or both radiator parts 1 , 2 can be rotated about the longitudinal center axes of the helices 3 , 5 .
[0050] In the first embodiment, the two separate radiator parts 1 , 2 with the conductor part 4 and the open turn 6 makes it possible to tune the antenna in a simple manner to a desired radiation pattern such as, for example, a resonant frequency. More precisely, the fact that the first and second radiator parts 1 , 2 are coupled to one another and can be rotated with respect to one another provides the possibility of changing the resonant frequency of the tunable antenna. For example, following a measurement of the actual resonant frequency of the tunable antenna after its manufacture, the resonant frequency of the tunable antenna can be changed by altering the coupling between the radiator parts 1 , 2 through rotation of the part 1 , 2 with respect to one another because such a rotation changes the effective radiator length of the radiator parts 1 , 2 of the tunable antenna. The resonant frequency of the tunable antenna is a function of the effective radiator length.
[0051] As such, the effective radiator length of the radiator parts 1 , 2 exhibits a value that is associated with a respective degree of rotation because, due to the rotation, the conductor part 4 that is electrically in contact with the open turn 6 migrates along the open turn 6 .
[0052] It is noted that the antenna of the first exemplary embodiment of the invention can be made of more than the two radiator parts 1 , 2 shown in FIG. 1. For example, such radiator parts 1 , 2 can be disposed in an arbitrary number in alternating sequence if the radiator parts 1 , 2 that do not represent the outermost radiator parts 1 , 2 of the antennas exhibit both a conductor part 4 and an open turn 6 .
[0053] Furthermore, it is noted that the conductor part 4 can also be disposed such that the longitudinal center axis of the conductor part 4 extends inclined to the longitudinal center axis of the helix 3 . Also, the open turn 6 can be disposed in a plane that extends inclined to the longitudinal center axis of the helix 5 as long as the radiation pattern of the antenna can be changed by rotation. For the invention, however, it is not mandatory for the open turn 6 to be located in one plane.
[0054] [0054]FIG. 2 illustrates a representation of a tunable antenna according to a second exemplary embodiment of the invention. Apart from the changes described below, the second exemplary embodiment is similar to the first, which has been described above.
[0055] In addition to the first and second radiator parts 1 , 2 of the first embodiment, the second embodiment has a third radiator part 7 having a structure differing from the first and second radiator parts 1 , 2 . The third radiator part 7 includes a radiating or non-radiating rod 8 , a conductor part 9 , and an open turn 10 . In the configuration, the conductor part 9 is provided at one end of the rod 8 and the open turn 10 is provided at another end of the rod 8 as shown in FIG. 2. The non-illustrated longitudinal center axis of the conductor part 9 is aligned with the non-illustrated longitudinal center axis of the rod 8 , and the open turn 10 is disposed in a plane extending perpendicular to the longitudinal center axis of the rod 8 .
[0056] In the second embodiment, the third radiator part 7 is disposed between the first radiator part 1 and the second radiator part 2 . More precisely, the three radiator parts 1 , 2 , 7 are disposed such that the longitudinal center axes of the first and second radiator parts 1 , 2 are aligned, and the longitudinal center axes of the rod 8 and of the conductor part 9 of the third radiator part 7 extend parallel to the longitudinal center axes of helices 3 , 5 of the first and second radiator parts 1 , 2 . Furthermore, the conductor part 4 of the first radiator part 1 electrically contacts the open turn 10 of the third radiator part 7 and the conductor part 9 of the third radiator part 7 electrically contacts the open turn 6 of the second radiator part 2 .
[0057] At least one of the radiator parts 1 , 2 , 7 can be rotated about the longitudinal center axes of the helices 3 , 5 of the first and second radiator parts 1 , 2 and 7 in order to achieve a tuning of the tunable antenna by the rotation of a respective radiator part or radiator parts 1 , 2 , 7 , as in the first exemplary embodiment. According to the second embodiment, however, there is a two-fold possibility of tuning the tunable antenna. The first possibility is in the rotation of the first and second radiator parts 1 , 7 with respect to one another and the second possibility is in the rotation of the third and second radiator parts 7 , 2 with respect to one another.
[0058] The advantages that have been described above are also achieved in the second embodiment.
[0059] It is noted that the antenna of the second embodiment can be made of more than the three radiator parts 1 , 2 , 7 shown in FIG. 2. For example, such radiator parts 1 , 2 , 7 can be disposed in an arbitrary number such that the longitudinal center axes of the helices 3 , 5 of the first and second radiator parts 1 , 2 are aligned, and the longitudinal center axes of the rod 8 and of the conductor part 9 of the third radiator part 7 extend parallel to the longitudinal center axes of the helices 3 , 5 of the first and second radiator parts 1 , 2 . In the configuration, a conductor part of a radiator part electrically contacts an open turn of an adjoining radiator part, and at least one of the radiator parts 1 , 2 , 7 can be rotated about the longitudinal center axes of the helices 3 , 5 of the first and second radiator parts 1 , 2 .
[0060] A further possible embodiment of the tunable antenna is made, for example, in providing a first radiator part that is only formed from a radiating or non-radiating rod and a second radiator part that has a structure identical to the second radiator part 2 in FIG. 2. In such a configuration, too, there exists the possibility of tuning the antenna by rotating it to a desired radiation pattern.
[0061] As in the first embodiment, it is not mandatory in the second embodiment, either, for the aforementioned aligned, perpendicular and parallel relations between the individual parts of the tunable antenna to be maintained as long as the radiation pattern of the antenna can be changed by rotation.
[0062] According to the first and second embodiments of the invention, the respective radiator parts of the tunable antenna are electrically coupled to one another. However, the invention is not restricted to such an electrical coupling. Instead, the respective radiator parts can also be capacitively coupled to one another, as is shown in FIG. 3.
[0063] According to the third embodiment, the first radiator part 1 also has a plate part 11 instead of the conductor part 4 shown in FIG. 1 and the second radiator part 2 has, instead of the open turn 6 in FIG. 1, a plate part 12 . The plate parts are respectively provided at one end of the helices 3 , 5 , respectively, of the first and second radiator part 1 , 2 , respectively.
[0064] In the configuration, the plate part 11 is disposed in a plane extending inclined to the longitudinal center axis of the helix 3 of the first radiator part 1 . The plate part 12 is located in a plane that extends inclined to the longitudinal center axis of the helix 5 of the second radiator part 2 . In the configuration, however, the two plate parts 11 , 12 can also extend perpendicularly to the longitudinal center axes.
[0065] Furthermore, the first and second radiator parts are disposed similar to the first exemplary embodiment such that the longitudinal center axes of the helices 3 , 5 of the first and second radiator parts 1 , 2 are aligned. In the configuration, the plate part 11 is opposite the plate part 12 at a predetermined distance, as shown in FIG. 3. Furthermore, at least one of the two radiator parts 1 , 2 can be rotated about the longitudinal center axes of the two radiator parts 1 , 2 such that an area of coverage of the plate parts 11 and 12 can be changed with the respective degree of a rotation. As such, a capacitive coupling is formed between the first and second radiator parts 1 , 2 . The capacitance of the coupling between these radiator parts 1 , 2 can be changed with the degree of rotation so that the tuning of the tunable antenna to a desired radiation pattern is carried out through the change in capacitance between the two radiator parts 1 , 2 .
[0066] The third embodiment also provides the advantages of the first and second embodiments.
[0067] Although FIG. 3 shows that the plate parts 11 and 12 have a shape of a disc segment, the possibility also exists for other shapes as long as the area of coverage of the plate parts 11 and 12 can be changed by rotation.
[0068] As in the first and second embodiments, it is not mandatory in the third embodiment, either, for the aforementioned aligned, perpendicular, parallel, and inclined relations between the individual parts of the tunable antenna to be maintained as long as the radiation pattern of the antenna can be changed by rotation.
[0069] According to the first to third embodiments, the respective radiator parts of the tunable antenna are electrically or capacitively coupled to one another. However, the invention is not restricted to such electrical or capacitive coupling. Instead, the respective radiator parts can also be coupled inductively to one another. Such inductive coupling can be achieved, for example, by a first helix and a second helix respectively having a meander-shaped part 13 , 14 as shown in FIG. 4. The meander-shaped parts 13 , 14 are in contact with one another such that the inductance formed by the two meander-shaped parts 13 , 14 together can be changed by a rotation of the parts. Rotation can be performed by measures similar to those described in the first to third embodiments. The respective meander-shaped parts 13 , 14 can be radiating parts.
[0070] A significant advantage that is achieved in accordance with the first to fourth exemplary embodiments of the invention is that the total length of the antenna in the direction of the longitudinal center axes of the radiator parts 1 , 2 is always the same independently of a rotation of the radiator parts 1 , 2 .
[0071] [0071]FIG. 5 illustrates a tunable antenna according to another embodiment of the invention. As shown in FIG. 5, first and second radiator parts 1 , 2 exhibit a first helix 3 and, respectively, a second helix 5 . The two radiator parts 1 , 2 are disposed with respect to one another such that longitudinal center axes of the helices 3 , 5 are aligned and the radiator parts 1 , 2 overlap one another in the direction of the longitudinal center axes of the helices 3 , 5 . More precisely, the first radiator part 1 in the embodiment is disposed such that it is located with a certain length within the second radiator part 2 . Accordingly, the outside diameter of the first radiator part 1 is smaller than the inside diameter of the second radiator part 2 . Furthermore, at least one of the first and second radiator parts 1 , 2 can be rotated about the longitudinal center axes of the helices 3 , 5 of the first and second radiator parts 1 , 2 , or displaced in the direction of these longitudinal center axes, such that the area of overlap of the radiator parts 1 , 2 can be changed with the degree of rotation and/or displacement.
[0072] Rotation is achieved by the two radiator parts 1 , 2 either performing a helical movement with respect to one another or a displacement with respect to one another in the direction of the longitudinal center axes of the helices 3 , 5 . In other words, according to the embodiment the two radiator parts 1 , 2 are not only rotated with respect to one another but, during a rotation of the two radiator parts 1 , 2 with respect to one another, there is also a displacement in the direction of the longitudinal center axes of the helices 3 , 5 of the two radiator parts 1 , 2 . Or, the two radiator parts 1 , 2 are simply displaced in the direction of the longitudinal center axes of the helices 3 , 5 . As a result, the coupling between the two radiator parts 1 , 2 is changed as a function of the degree of a rotation and/or displacement. Accordingly, a tuning of the radiation pattern of the tunable antenna is achieved by the change in the coupling between the two radiator parts 1 , 2 .
[0073] A further possibility exists in the two radiator parts 1 , 2 not overlapping one another but being located opposite one another at a predetermined distance. In such an embodiment, too, a coupling of the two radiator parts 1 , 2 can be changed as described above. As a result, the radiation pattern of the antenna can be similarly adjusted.
[0074] The advantages engendered in the other embodiments of the invention are also achieved by the embodiment. However, in the embodiment, the total length of the tunable antenna changes when it is being adjusted.
[0075] The antennas described above can be configured such that the respective radiator parts are fixed with respect to one another after having been set to a desired radiation pattern.
[0076] It is advantageous to construct the tunable antennas by using the molded interconnect device technology. The individual separated radiator parts are constructed on mutually separated carriers, which are preferably round or angular. In such MID antennas, the essential advantage is that they can be set to a desired radiation pattern simply by using the rotation and/or displacement of the carriers on which the radiator parts are constructed without requiring expensive changes in or on the tool.
[0077] In the manufacture of such MID antennas, the possibility then exists to adjust these antennas to a desired radiation pattern with little manufacturing expenditure during the current production process of the MID antennas.
[0078] In general, such antennas have a cap that covers them. The cap is used as mechanical protection and/or for improving the external appearance of the antenna. In the aforementioned antennas there is also an advantage in that they can be adjusted to a desired radiation pattern during the manufacturing process before and/or after the cap has been placed on. That is to say, if the antennas are adjusted after the cap has been placed on, tolerances of the cap which have an effect on the radiation pattern can be taken into consideration when the antennas are adjusted to a desired radiation pattern.
[0079] It is also noted that an arbitrary combination of the aforementioned exemplary embodiments with one another is also possible if the shapes of the individual radiator parts are suitably adapted. If, for example, a radiator part with a helix and a conductor part at one end of the helix is coupled to another radiator part having a helix with an open turn at one end of the helix and a plate part at the other end of the helix, and the further radiator part is coupled to yet another radiator part having a helix with a plate part at one end of the helix, a tunable antenna can be constructed that can be tuned to a desired radiation pattern both by an electrical coupling and a capacitive coupling of the various radiator parts. Similarly, many other combinations of the embodiments with one another are possible.
[0080] Furthermore, the shape of the individual components effecting a coupling between the radiator parts such as, for example, the conductor part and the open turn, is not restricted to that previously described with respect to the exemplary embodiments but, instead, components with other shapes can be used as long as they meet the condition that an electrical, capacitive, or inductive coupling between two radiator parts can be changed by a rotation and/or displacement of these radiator parts with respect to one another in order create the possibility of tuning the tunable antenna to a desired radiation pattern in a simple manner.
[0081] The individual parts of the respective radiator parts can also be constructed integrally with one another. For example, the conductor part can simply be one end of a helix of the radiator part.
[0082] Furthermore, it is noted that the aligned, parallel, and perpendicular relations of the different parts of the tunable antennas according to the exemplary embodiments described above are not mandatory as long as the tunable antennas can be rotated and/or displaced such that the radiation pattern of the antennas can be changed by rotation and/or displacement of the radiator parts of the antennas.
[0083] In this context, a displacement of the radiator parts of the antennas with respect to one another can also take place, for example, in a direction extending perpendicularly or inclined to the longitudinal center axes of the helices. Thus, the third embodiment, for example, can be configured such that a displacement in the direction of the longitudinal center axes of the helices 3 , 5 and/or a displacement perpendicular to the longitudinal center axes of the helices 3 , 5 can be carried out in addition to or instead of the rotation.
[0084] Finally, it is noted that the respective helices can exhibit an identical or a different pitch and/or identical or different diameters and/or equal or oppositely directed pitches.
[0085] Similarly, parts having different shapes can be used instead of the helices. For example, such parts can be meander-shaped.
[0086] A process for manufacturing tunable antennas in the exemplary embodiments described above, in which a tuning of the tunable antennas to a desired radiation pattern can be achieved in a simple manner, will be described in the following text.
[0087] In accordance with the process, the respective antennas of any of the exemplary embodiments are first manufactured. More precisely, the respective radiator parts of a respective antenna are constructed and these radiator parts are configured such that they are coupled to one another and can be rotated and/or displaced with respect to one another. In the process, the radiator parts are applied to respective carriers, preferably by the MID technology. Following the manufacturing, the actual radiation pattern of a respective antenna is measured. Finally, the effective radiator length of the radiator parts is set by rotating and/or displacing the radiator parts with respect to one another in order to set a nominal radiation pattern of the respective antenna.
[0088] The process is advantageous in that it can be carried out during the manufacturing process of the antennas and, accordingly, a continuous check of the respective antennas takes place. Such continuity significantly improves both the quality of the antennas and the manufacturing yield.
[0089] A description of the mass production of the above mentioned tunable antennas follows. According to the process, a first arbitrary number of the tunable antennas according to one of the exemplary embodiments is manufactured. That is to say, the construction of the radiator parts and the configuration of the radiator parts with respect to one another are repeated a first arbitrary number of times. Then, the actual radiation pattern of one or more of the first arbitrary number of manufactured antennas is measured. Next, a second arbitrary number of antennas is manufactured, the nominal radiation pattern of these antennas is set based on a value that is derived from the actual radiation pattern of the one or more antennas of the first arbitrary number.
[0090] In the process, the nominal radiation pattern can be set either before or after, or both before and after, a cap has been placed on the antennas so that tolerances caused by the cap and that have an effect on the radiation pattern of the antennas can also be taken into consideration. The feature applies to both manufacturing processes described above.
[0091] In a further step, the radiator parts of the antennas can be brought into a mutually fixed relation after the nominal radiation pattern has been set, so that a change in the radiation pattern of the antenna is prevented.
[0092] A further essential advantage of the aforementioned processes is that these manufacturing processes can be corrected continuously.
[0093] According to the above exemplary embodiments, the dispersion of the resonant frequency between various tunable antennas can be significantly reduced. For example, the quality and yield can be significantly increased.
[0094] Finally, it is noted that investigations by the inventors of the invention have led to the following results. An investigation of a tunable antenna according to the first exemplary embodiment of the present invention described above was made. In the investigation, the first radiator part 1 was located on a rotatable Teflon mandrel and the open turn 6 of the second radiator part 2 had a gap of 30°. The configuration resulted in a tunable antenna, having an actual resonant frequency of, for example, 700 MHz, with a maximum possible rotation of 330°, exhibiting a wide tuning range of approximately 20 to 25 MHz.
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A tunable antenna includes separate radiator parts coupled to one another. The coupling between the parts is changed by rotating and/or displacing the parts with respect to one another such that the antenna exhibits a radiation pattern associated with a respective degree of a rotation and/or displacement. A process for manufacturing such antennas includes constructing parts for a respective antenna, coupling the parts to one another to permit them to rotate and/or displace, measuring the radiation pattern of the parts, and adjusting the radiation pattern by rotating and/or displacing the parts with respect to one another to set a nominal radiation pattern of the respective antenna formed by the parts. The couple is changed by rotation and/or displacement of the parts. A respective degree of rotation and/or displacement creates a corresponding change of a radiation pattern of the parts.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to network communication control apparatus and method that perform network facsimile communication via LAN and Internet, using a facsimile apparatus.
2. Description of Related Art
In recent years, Internet facsimile apparatuses that employ the Internet are introduced, with the increasing use of the Internet. For example, Japanese Patent No. 3,133,297 (filed by the same applicant as this invention) proposes a network communication control apparatus that enables an Internet phone and Internet facsimile communications by connecting with analog communication terminals such as general telephones and facsimile apparatuses.
According to the above communication control apparatus, facsimile data transmitted from a general facsimile apparatus is converted into a TIFF file and attached to e-mail, to be further transmitted to other communication terminals such as the opposing Internet facsimile apparatus, computer, and network communication control apparatus similar to the sending apparatus. In addition, it is possible to receive e-mail data from other communication terminals via network, convert the data into facsimile data, and transmit the facsimile data to a connected general facsimile apparatus.
With the above communication control apparatus, when a facsimile apparatus completes a facsimile data transmission to the communication control apparatus, the facsimile apparatus determines that the transmission is complete, allowing the operator to assume that the transmission process is thus complete.
However, there are cases when the communication control apparatus attempts to transmit e-mail but fails to transmit the same, because of a power failure at the communication control apparatus due to problems such as a power outage. The transmission of e-mail data is also impossible when the network cable is disconnected or when the mail server is down.
In addition, even if e-mail data is received from another communication terminal, there are cases when the data cannot be forwarded to a facsimile apparatus because of a power failure at the communication control apparatus due to problems such as a power outage. However, the e-mail is still received. Therefore, the mail server completes the procedure as usual, without sending error mail, allowing the sender to assume that the transmission has been completed.
In order to address the problem, the communication control apparatus may include an uninterruptible power supply or a non-volatile memory for storing data. However, such an attempt complicates the structure, up-sizes the apparatus and significantly raises the cost. Since facsimile transmissions are based on premise that the sender should re-transmit data when a transmission fails, it is not very important to store the transmission data as long as the sender is notified that the transmission is incomplete.
SUMMARY OF THE INVENTION
The present invention addresses the above-described problems in the prior art. The object of the invention is to provide a network communication control apparatus that notifies a sender so as to instruct for a re-transmission upon recovery, when data is lost without completing a transmission, e.g., SMTP session failure, in situations where the power for the network communication control apparatus fails, a network cable is disconnected, or the mail server is down.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is further described in the detailed description which follows, with reference to the noted plurality of drawings by way of non-limiting examples of exemplary embodiments of the present invention, in which like reference numerals represent similar parts throughout the several views of the drawings, and wherein:
FIG. 1 illustrates a configuration of a state in which an Internet communication control apparatus as a network communication control apparatus according to an embodiment of the present invention is connected to a facsimile apparatus and the Internet via LAN.
FIG. 2 is a block diagram illustrating a main configuration of the Internet communication control apparatus according to the present invention.
FIG. 3 is a flowchart illustrating an operational process of the Internet communication control apparatus according to the present invention.
FIG. 4 is a flowchart illustrating an operational process of the Internet communication control apparatus according to the present invention.
FIG. 5 is a flowchart illustrating an operational process of the Internet communication control apparatus according to the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The preferable embodiment of the present invention is explained in the following, in reference to the above-described drawings.
FIG. 1 illustrates a configuration of a state in which Internet communication control apparatus 1 as a network communication control apparatus according to the present invention is connected to facsimile apparatus 2 and Internet 5 via LAN 4 . Apparatuses such as another Internet communication control apparatus 1 , computer 6 having an Internet facsimile function, Internet facsimile apparatus 7 dedicated to Internet facsimile transmissions, and gatekeeper 8 , which associates an IP address/e-mail address with a telephone number, are connected to Internet 5 via other LANs.
FIG. 2 is a block diagram illustrating a main configuration of Internet communication control apparatus 1 . This communication control apparatus 1 includes power unit 11 , facsimile communication controller 12 that is connected to facsimile apparatus 3 via an interface (not shown in FIG. 2 ), LAN controller 13 that is connected to LAN 4 , e-mail communication controller 14 that exchanges e-mail with LAN 4 , data processor 15 that is connected to facsimile communication controller 12 and e-mail communication controller 14 (later described), and memory 16 that stores data and is connected to data processor 15 . Memory 16 includes large capacity DRAM 17 that operates only when the power is supplied from power unit, stores transmission contents, and is capable of high speed storing process, and FROM (flash memory) 18 that is configured with a non-volatile memory, which stores transmission managing data and cannot be erased even when the power fails. Moreover, the RAM that stores transmission contents is not limited to DRAM as long as it is capable of performing a data storing process faster than the FROM, therefore, other kinds of memories can be employed as the RAM.
Error detector 20 that detects an error is connected to FROM 18 , while error message generator 21 is connected to error detector 20 . Error message generator 21 is connected to facsimile communication controller 12 and e-mail communication controller 14 . Error detector 20 searches for an error from managing data stored in FROM 18 , the error being caused by factors such as a power outage during e-mail/facsimile communication. Error message generator 21 then generates an error message of facsimile/e-mail data in accordance with the sender, so that the error message is delivered to the sender. Furthermore, managing data eraser 22 , which is connected to facsimile communication controller 12 and e-mail communication controller 14 , is connected to FROM 18 , so that unnecessary managing data is erased in FROM 18 .
The list of managing data includes “mode” that indicates whether the transmission comes from facsimile apparatus 2 (facsimile data) or other communication terminals (e-mail data), “destination” that includes telephone numbers and e-mail addresses, “sender” that includes telephone numbers and IP addresses, and “subject” that includes headlines.
Data processor 15 temporarily stores facsimile data in DRAM 17 , the data being received from facsimile apparatus 2 via facsimile communication controller 12 , converts the data into e-mail data, and transmits the same as e-mail to other communication terminals from e-mail communication controller 14 and LAN controller 13 via LAN 4 and Internet 5 . Conversely, data processor 15 also analyzes e-mail data from LAN 4 , converts the same into facsimile data, temporarily stores the same in DRAM 17 , and transmits the facsimile data to facsimile apparatus 2 via facsimile communication controller 12 .
FIGS. 3-5 illustrates a main operational process of Internet communication control apparatus 1 . As shown in FIG. 3 , when Internet communication control apparatus 1 is turned on at Step 1 , a start-up process is performed at Step 2 , and error detector 20 determines whether there is managing data that is not erased in FROM 18 , i.e., whether there is a communication process that has not completed a data exchange at Step 3 . When there is no such data, the control proceeds to a normal process that is not shown in the figures.
When un-erased managing data is found, it is determined whether the error is caused by a power outage during a transmission from facsimile apparatus 2 or during a transmission from another communication terminal to facsimile apparatus 2 at Step 4 . When the error is not cause by a power outage during a transmission from facsimile apparatus 2 , i.e., when the error is caused by a power outage during a transmission from another communication terminal to facsimile apparatus 2 , the control proceeds to Step 5 , to generate an e-mail data error message using error message generator 21 and to transmit e-mail regarding the instantaneous interruption to the sender communication terminal via LAN 4 and Internet 5 , from e-mail communication controller 14 and LAN controller 13 . At Step 6 , error message generator 21 via managing data eraser 22 erases managing data that is stored in FROM 18 , to proceed to a normal process that is not shown in the figures.
When it is determined that the error is caused by a power outage during a transmission from facsimile apparatus 2 at Step 4 , the control proceeds to Step 7 wherein error message generator 21 generates a facsimile data error message, which is transmitted as an instantaneous interruption report to facsimile apparatus 2 via facsimile communication controller 12 . Then, the control proceeds to Step 6 .
As shown in FIG. 4 , when e-mail data is received from another communication terminal during a normal procedure, upon completing a reception at Step 11 , managing data is stored in FROM 18 at Step 12 . Then, the e-mail data is converted into facsimile data and temporarily stored in DRAM 17 . Next, the facsimile transmission to facsimile apparatus 2 starts. During this time, the facsimile transmission initialization is confirmed at Step 13 . When the facsimile transmission initialization is successful, the control waits until the facsimile transmission is completed at Step 14 . Then, managing data stored in FROM 18 is erased via managing data eraser 22 at Step 15 , which completes the process.
When the facsimile transmission initialization cannot be confirmed due to errors such as the power being out at facsimile apparatus 2 and telephone line being disconnected, i.e., when the facsimile transmission initialization is unsuccessful, error message generator 21 generates an e-mail data error message so that the transmission error information is transmitted as e-mail to the sender communication terminal, from e-mail communication controller 14 and LAN controller 13 via LAN 4 and Internet 5 . At Step 15 , the managing data that is stored in FROM 18 is erased via managing data eraser 22 , which completes the process.
As shown in FIG. 5 , when facsimile data is received from facsimile apparatus 2 , the facsimile data is temporarily stored in DRAM 17 upon completing the reception at Step 21 , and the managing data is stored in FROM 18 at Step 22 . Next, the facsimile data is converted into e-mail data in data processor 15 , and the e-mail transmission starts at Step 23 . Here, a telephone number is input as a destination instead of an e-mail address. Thus, an e-mail address is obtained either by referring to a corresponding table within communication control apparatus 1 (no shown) that associates telephone numbers with e-mail addresses, or by accessing gatekeeper 8 , in order to perform an e-mail transmission. When the completion of e-mail transmission is confirmed at Step 24 , the managing data stored in FROM 18 is erased via managing data eraser 22 at Step 25 , which completes the process.
In addition, when the completion of the e-mail transmission cannot be confirmed at Step 24 , because of errors such as the mail server being down, a signal line being disconnected, i.e., when the e-mail transmission is unsuccessful, error message generator 21 generates a facsimile data error message, so that the transmission error report is transmitted as facsimile data to sender facsimile apparatus 2 via facsimile communication controller 12 . Then, at Step 25 , the managing data that is stored in FROM 18 is erased via managing data eraser 22 , which completes the process.
Accordingly, when either facsimile communication or e-mail communication is complete, managing data is erased in FROM 18 . When the communication fails, the sender is first notified of the error, and the managing data is erased in FROM 18 . Therefore, when managing data is found in FROM 18 , it indicates that the communication has failed and the sender has not been notified of the error. This further implies that the power is out at Internet communication control apparatus 1 . Therefore, by detecting the problem when the power comes back, it is possible to notify the sender of any errors.
It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the present invention has been described with reference to exemplary embodiments, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the present invention has been described herein with reference to particular structures, materials and embodiments, the present invention is not intended to be limited to the particulars disclosed herein; rather, the present invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims.
The present invention is not limited to the above-described embodiments, and various variations and modifications may be possible without departing from the scope of the present invention.
This application is based on the Japanese Patent Application No. 2001-355905 filed on Nov. 21, 2001, entire content of which is expressly incorporated by reference herein.
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A network communication control apparatus that converts data from a facsimile apparatus into e-mail to transmit to another communication apparatus, and converts e-mail from another communication apparatus into facsimile data to transmit to the facsimile apparatus, the network communication control apparatus further stores managing data that includes whether transmission to/from facsimile apparatus from/to another communication terminal is complete, determines whether the un-transmitted managing data is stored at a predetermined timing, and notifies the sender regarding the un-transmitted data, when the un-transmitted managing data is stored, according to the content of data. This is to allow the sender to be easily and automatically notified when the data transmission is incomplete, and to improve the reliability of the network communication control apparatus.
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This is a continuation of application Ser. No. 08/147,147, filed Nov. 2, 1993, now abandoned.
BACKGROUND OF THE INVENTION
The invention relates to a apparatus and methods for accelerated processing of transactions on computer databases.
A computer database is a collection of data records, each having one or more logical keys that serve as "names" for the records. Typically, when an application program requests access to a record in the database, it presents a logical key value to a database manager program, which in turn consults information from an index kept on disk or in memory to map the logical key value to a record address value. This record address value specifies the location on the disk where the data record(s) associated with the logical key value is to be found. Thus, the database index functions very much like a book's index: a reader provides a logical key value (the topic of interest), and the index in return provides a record address value (the page number) where the information is to be found.
A database may have multiple keys. Typically one is selected as a "primary key" that provides unambiguous and rapid access to the record, and "secondary keys" provide access that is either slower or less specific to a single record. For instance, an employee database may use employee number as its primary key, and employee name and department number as secondary keys. The key index is a permanent part of the database as it resides on disk. It may either be stored in the same file as the data records themselves (like a table of contents bound in a common binding with the text of a book), or may reside in separate files (like the index/overview volume of a multi-volume encyclopedia.)
Known database management systems divide into two logical layers: an upper layer called the database manager provides a user interface (for instance, a database query language), and a lower layer called a database engine maintains the structure of the database, that is, the relationship between the logical keys and the physical data actually stored in the database file.
SUMMARY OF THE INVENTION
In a first aspect, the invention provides a hardware accelerator for managing a computer database. The accelerator includes a key memory for storing a map associating record key values to record address values, a search processor for searching the key memory for a given key value and providing the associated record address value to the central processor, a bus interface for interfacing the search processor and the key memory to the central processor, and database management software for execution on the central processor that requests a mapping from key values to record address values by issuing requests over the bus interface to the search processor.
Preferred embodiments of the invention may include the following features. The key memory map may store mappings from a single key value to multiple record addresses, for instance for non-unique secondary keys. The search processor may include structure for searching the key memory with a binary search structure that provides the first entry of the key memory matching a given key value. The database management software has structure for performing a mapping from a logical key value to an encoded key value before providing a key value to the search processor for mapping to a record address. The central processor includes structure for allocating the key memory. An index file stored on a disk memory of the host computer may store an image of the contents of the key memory. There may be a memory port through which the central processor can read and write the key memory. The search processor may provide to the central processor an index of an entry of the key memory corresponding to the given key value, and the database management software may then read entries from the key memory corresponding to the index. The database accelerator may include structure for adding and/or deleting entries to/from the key memory.
In a second aspect, the invention features a modified binary search, particularly useful for searching a memory in which the search values of the entries are not unique. The modified binary search finds the first entry in the memory matching a given value. As in a normal binary search, the entries are stored in the memory in sorted order. A probe address, the average of a start and end address, is formed, and the corresponding entry probed. Depending on a comparison of the probed entry with the given value, either the start or end address is set equal to the probe address. The modification exploits the CARRY generated by the comparison of the probed entry to the given value to alter the probe address calculated in the next iteration of the search. Instead of terminating when the given value is found, the search continues until the start and end addresses have converged on the first entry that matches the given entry.
Among the advantages of the invention are the following. A database manager using the database accelerator runs much faster than one without an accelerator because mapping a logical key value to a record address value can be accomplished without accessing the disk copy of the index information. The invention offers a copy-proof feature to a database software vendor: an illicit copy of the database management software is useless without the database accelerator board. Prior software database engines have forced a tradeoff between fast access for search purposes, but slow access for addition or deletion of records (typical of hierarchical organization) and fast addition or deletion of records, but slow search (typical of relational databases). In contrast, the invention performs both search and update functions at speeds much faster than either software database engine, and is simpler to design.
Other advantages and features of the invention will become apparent from the following description of a preferred embodiment, and from the drawing, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a computer with a database accelerator.
FIG. 2 shows disk records of a database, and a database accelerator having a key memory.
FIG. 3 is a block diagram of the database accelerator.
FIGS. 4A and 4B are a flow chart of the operation of the database accelerator.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, personal computer 100 has a central processor unit (CPU) 102, a random access memory (RAM) 104, and a disk or other mass storage unit 106, all communicating over a system bus 108. Disk 106 holds the data 110 and index 112 files that constitute a database, and CPU 102 runs database management software 114 and application software 116 stored in RAM 104. A database accelerator 120 also communicates over bus 108, and has a control logic 122 and a key memory 124.
During a start-up phase, discussed below, the index information to map logical key values to record address values is loaded into key memory 124 from index file 112 for fast access.
In general operation, application software 116 requests an operation from database manager 114. If the request is one of SEARCH, ADDITION, or DELETION, database manager 114 in turn passes the request to database accelerator 120 over system bus 108 through a bus interface 130, bypassing the step of accessing database index file 112. Considering a SEARCH operation as a typical operation performed by database accelerator 120 (SEARCH, ADDITION, and DELETION will be discussed in greater detail below, in connection with FIG. 4), database manager 114 presents a logical key value to database accelerator 120 and a command to SEARCH for the logical key. Within database accelerator 120, control logic 122 (which may be a state machine) directs the requested operation in the accelerator's key memory 124. If the logical value is found in key memory 124, control logic 122 provides a record address value associated with the logical key value to database manager 114, which can then access the appropriate database record in database file 110.
Referring to FIG. 2, the database accelerator's key memory 124 is organized as if it had two columns, a left column 202 for encoded logical key values and a right column 204 for the associated record address values. In FIG. 2, database 110 with index 112 is illustrated as having five data records, each with primary and secondary keys. During the start-up phase, these primary and secondary encoded logical keys were loaded, with their associated record addresses, into key memory 124, in sorted order according to their key values. During general operation, control logic 122 directs a search of left column 202 for an encoded logical key value 211-215 or 221-225. When the encoded logical key value is found, the corresponding entry in the right column is the record address value 231-235 or 241-245 for the record 251-255. Thus, key memory 124 serves as a cache over the information in index file 112.
Referring to FIG. 3, database accelerator 120 has a bus interface 130 whose design is largely determined by the bus protocol of the host computer, for instance the AT, ISA, EISA, Microchannel, or Macintosh bus architectures found on various models of personal computers. The logic of FIG. 3 may be implemented in any convenient technology, for example, custom VLSI, gate arrays, field-programmable gate arrays, programmable logic arrays (PALs), a bit-slice processor, or a microprocessor. Key memory 124 is sized to hold the desired keys of database 110, typically 256 kB.
Database accelerator 120 has a number of data and control registers that are mapped into the memory space of host processor 102. Host processor 102 typically requests a service from database accelerator by writing values into the registers, for instance a value to search for, the low and high bounds of the region of key memory to search, a command value (for instance SEARCH), and a GO command. While database accelerator 120 services the request, host processor 102 can await the completion of the operation either by performing other functions or by executing a spin wait on a status register of the database accelerator. These steps are discussed in greater detail below.
Key memory 124 can be read and written by the host. To access key memory, host 102 writes a memory LOAD or UNLOAD command into control buffer 301. In response, address multiplexer passes the address value of address buffer 309 to key memory 124. When control buffer 301 is set to LOAD, any data value written to memory data buffer 303 will in turn be written to key memory 124 at the address specified in address buffer 309. Similarly, when control buffer 301 is set to UNLOAD, the cell value addressed by address buffer 309 will be copied to memory data buffer 303 for the host to read. Because key memory 124 is typically quite large, control buffer 301 stores high address bits moving a "window" over key memory 124; the low order address bits are stored in address buffer 309.
The start-up phase, now discussed in greater detail, proceeds as follows. Key memory 124 is loaded with encoded logical key/record address value pairs. The encoded logical key values are stored in one column 202 of key memory 124 as 16-bit encoded key values; and host processor 120 maps each arbitrary-length logical key value to a 16-bit encoded key value by any convenient method, for instance by a known hash function such as CRC (circular redundancy check). Thus, several logical key values may map to the identical encoded key value, and can have different record addresses. The record address values column in FIG. 2 are stored in a second column 204 as 16-bit integers, representing record numbers within database file 110. To load key memory 124, host database software 114 obtains from the database 110, 112 a count of the number of records and the logical and record address values for the database records, and selects which encoded logical key and record addresses will be stored in key memory 124. For instance, index file 112 may store the encoded logical keys and record addresses in exactly the format used in key memory 124 in which case it is possible to load key memory 124 by simply copying the index from index file 112 to key memory 124. Or, host database software 114 may read the records of database file 110, extract the logical keys, map them to 16-bit encoded keys, and store the encoded key/record address pairs in key memory 124 using the LOAD command described above.
Host database software 114 manages key memory 124, for instance apportioning key memory 124 among multiple logical keys. For instance, if key memory 124 has 4096 entries and database file 110 has three keys (typically a primary and two secondary keys), host database software 114 may decide to store the primary key in entries 0 through 1365, the secondary keys in entries 1366 through 2730, and tertiary keys in entries 2731 through 4095. Host database software 114 maintains the range of key memory apportioned to each logical key so that it can specify the correct bounds for each SEARCH, ADDITION, or DELETION request. The entries in key memory 124 are managed as required by the search strategy implemented by the search circuits of database accelerator 120. For instance, if database accelerator 120 uses a binary search, then the entries in key memory must stored in sorted order with no gaps within the range allocated to a logical key.
FIG. 4 shows the operation of database accelerator 120 after key memory 124 has been apportioned and loaded. In step 402, host processor 102 writes command and data values to several of the accelerator's data registers, whose uses are specialized for each operation as discussed below. Compare step 408 discriminates between the various commands the SEARCH, DELETION, and ADDITION operations, each of which are discussed below.
Referring now to FIGS. 3 and 4, the SEARCH command uses a binary search to locate the first key value in a selected range of key memory corresponding to an encoded key value, and thus the entries of key memory 124 are stored sorted in ascending order by encoded key value 202. In step 402, host processor 102 stores the entry numbers of key memory 124 between which to search in a start address register SAR 316 and an end address register EAR 314. The encoded key value to search for is stored in a data buffer 310. A value specifying the SEARCH command is stored in a control buffer 301. Once these data have been stored in the respective registers in steps 402 and 404, host 102 writes a GO signal into the GO/result buffer 307 in step 404.
In step 406, database accelerator 120 responds by setting the value of control buffer 301, as read by host processor 102, to BUSY. In step 408, a control logic 302 determines which command to execute and controls the logic of database accelerator 120 to perform the appropriate command. The SEARCH procedure begins at step 410. A CARRY signal out of a comparator 318 is set to One by control logic 302. In later steps of the search, this CARRY signal is automatically generated by comparator 320 and is used to modify the normal rules for binary search so that if a selected encoded key value appears multiple times in key memory 124, the search will terminate at the sequentially first of these multiple entries instead of at the first hit. The FOUND signal is also set to Zero at step 410. This FOUND signal indicates whether any entries in key memory 124 match the encoded logical key value, and thus whether the search has succeeded. In step 412, an adder 317 adds the contents of SAR 316, EAR 314, and CARRY, and divides by two in a shift register 320, to form value M1, the address in key memory 124 to probe in this step of the binary search. In step 414, a FINISHED flag records the value of M1 is compared to the current value of SAR 316 via comparator 319, indicating that this is the last probe of the binary search. Looking ahead to step 426, if the FINISHED flag was set in 414 then this probe at entry M1 is the final probe of the binary search, and the search can terminate on this iteration.
In step 416, M1 is multiplexed through an address multiplexer 308 to address key memory 124. The encoded key/record address value at entry M1 of key memory 124 is loaded into a temporary buffer 311. In step 418, the search key value from data buffer 310 is compared to the probed encoded key value 311 by a comparator 320. Control logic 302 uses the outcome of comparator 320 to determine whether the probed encoded key value is less than, equal to, or greater than the search key value. In step 422, if the search key value and the probed key value are equal, then the CARRY out of comparator 320 is cleared (CARRY:=0). Control logic 302 sets the FOUND flag (FOUND:=1), and replaces the contents of EAR 314 with the value of M1. In step 420, if temporary buffer 311 (holding the probed key value) is less than data buffer 310 (holding the search key value), then value M1 is latched from address MUX 308 to SAR 316, and CARRY is set (to One). Otherwise, in step 424, the probed key value 311 is greater than search key value 310; and address M1 is latched from address MUX 308 to EAR 314, and CARRY is cleared. Note that the binary search does not halt on a match of the search key value with an encoded key value from key memory 124; the binary search continues until the low bound SAR 316 for the search and high bound EAR 314 have closed in on the first entry in key memory 124 that matches the search key value stored in data buffer 310.
At step 426, when the binary search has closed (that is, the contents of the EAR 314 (equal to the value M1) is within one of the contents of the SAR, M1 points to the first entry in key memory 124 matching the encoded key value, if such an entry exists between the original SAR and EAR values specified. If the FOUND flag was set in step 422, it is known that there is at least one matching entry. Thus a Yes comparison at 426 directs the processor to step 428, where the value M1 is written into GO/result buffer 307, and the FOUND status value is written into control buffer 301. A No comparison indicates that the binary search must continue, with the difference between EAR and SAR closed in half.
The database accelerator's search operation is complete at step 430. If the host processor 102 has been busy waiting on control buffer 301, it can now continue execution. Host processor 102 reads the M1 value from GO/result buffer 307, which in turn specifies an entry in key memory 124 to read. If the encoded key of this entry matches the sought encoded key, then the low 16 bits of this entry will specify a record to read from database file 110. Host processor 102 will typically read the indicated record from database file 110.
Because there may be multiple records with identical encoded key values (particularly for secondary keys where the logical keys themselves may be non-unique), it will typically be necessary to examine all records with the sought encoded key value. Search procedure 410-430 provided only the first entry of key memory matching the sought encoded key value; host processor 102 will typically use the UNLOAD command described above to read successive entries from key memory 124 and records from database file 110 until the encoded key value read from key memory 124 no longer matches the sought-for encoded key.
The DELETION and ADDITION operations are illustrated in flow chart steps 440-452. Since the array of encoded key and record address value pairs must remain dense (there may not be any holes in the key memory space dedicated to a particular logical key), ADDITION works by moving the portion of the array higher than the inserted key value up by one key memory location; host processor 102 then writes the new encoded key and record address pair into the selected location. DELETION, steps 450-454, works by copying the upper portion of the key memory down by one entry. Host database software 114 updates its end value so that the correct EAR value can be used to properly bound the next operation on key memory 124.
To execute an ADDITION (DELETION) command, in steps 402-404 host processor 102 writes a key memory entry number for the insertion (deleted) memory location to UCR 306, the last valid entry number to EAR 314, an ADDITION (DELETION) command value to control buffer 301, and a GO signal to GO buffer 307. In step 406, control logic 302 sets the value of control buffer 301 to BUSY, and to FOUND or NOTBUSY when the data movement is complete. In steps 440-442 (450-452), an ADDITION (DELETION) command moves all entries above the entry specified in UCR 306 up (down) by one entry. When an ADDITION command is completed by the database accelerator, one entry in the key memory will be duplicated, and a new entry can be written over the first one of the duplicates using the LOAD command described above. An ADDITION (DELETION) command is complete in step 446 (454).
The key map 124 is kept consistent with database file 110, for instance after DELETION and ADDITION commands. Some of the techniques used in traditional software database engines are usefully exploited, and some techniques can be dramatically simplified. The database manager 114 running on host computer 102 maintains a log file of transactions that records all transactions that write to the database file. A log file of transactions is maintained to assist in crash recovery. Because index searches, insertions, and deletions happen at RAM speeds in key memory 124 instead of at disk speeds in index file 112, the complex index files 112 (and complex database engine software to manipulate the index files) commonly used to obtain acceptable performance from hierarchical database managers are unnecessary. An index file that is simply an image of the key memory's 124 encoded key/record address pairs is sufficient, and can be updated infrequently, for instance when the user signs off for the day. If the computer crashes without updating index file 112 to consistency with database file 110, index file 112 can be regenerated from the records in database file 110. When the user exits normally, the host reads the entries from key memory 124 using its access window, and stores an image of key memory 124 to index file 112, bringing index file 112 into consistency with database file 110. When the user next logs into the database, key memory 124 can be loaded directly from index file 112.
After host database software 114 issues a command to database accelerator 120, host processor 102 enters a spin wait waiting for the database accelerator to set an "operation complete" status code in control buffer 301. The database accelerator is sufficiently fast that, for instance, a search of 64K entries in a 256K memory which uses sixteen probes, is completed in 937 ns for a 16 MHz database accelerator clock, two or three iterations of a spin loop for the host processor.
Other embodiments may organize the key memory differently. For instance, for a large database, it may be desirable to use 32-bit (or larger) representations for the encoded key and record address. A length register might specify a length for the encoded key value, or a type register would specify a collating sequence for logical keys. The record address may be stored in any convenient representation, for instance storing the disk volume, cylinder, head, and record at which to find the data record. The key memory can be organized to use any convenient search technique, for instance B-trees, hash tables, a Fibonaccian search, or an interpolation search. The choice of key memory organization may be influenced by the relative frequency of insertions and deletions with respect to searches.
Other embodiments are within the following claims.
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A hardware accelerator for managing a computer database. The accelerator includes a key memory for storing a map of record key values to record address values, a search processor for searching the key memory for a given key value and providing the associated record address value to the central processor, and a bus interface for interfacing the search processor and the key memory to the central processor. Database management software executing on the central processor requests a mapping from key values to record address values by issuing requests over the bus interface to the search processor. The accelerator also provides operations to add and delete entries in the key memory. The accelerator uses a modified binary search that is particularly useful for searching a memory in which the search values of the entries are not unique; the modified binary search finds the first entry in the memory matching a given value. At each iteration of the binary search, the CARRY generated by the comparison of the probed entry to the given value is used to alter the probe address calculated in the next iteration of the search. Instead of terminating when the given value is found, the search continues until the start and end addresses have converged on the first entry that matches the given entry.
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FIELD OF THE INVENTION
[0001] This invention relates to methods of molding unique hollow polyurethane objects and, more particularly, to a method of making aesthetically unique useful objects by providing a three-dimensional model of the object, forming a fiberglass mold of the three-dimensional model, and rotocasting the fiberglass mold to make the aesthetically unique useful object.
BACKGROUND OF THE INVENTION
[0002] Fashion forms are one type of useful object in which the aesthetics of the object is very important. Fashion forms are used to display clothing in store windows, on selling displays, etc. In the past, fashion forms typically have been made from solid foam material or fiberglass resin. For example, particularly detailed solid foam fashion forms have been made in the past by directly casting fiberglass molds from human models' bodies, and using the fiberglass molds, held in a stationary position, to prepare the solid foam fashion forms from appropriate foam-forming materials. Unfortunately, solid fashion forms are fairly easily damaged, since the surface of the material is not resilient and is easily dented, chipped or cut. Furthermore, solid foam fashion forms are expensive to manufacture due to the substantial amount of foam material present in each of the forms.
[0003] If equally detailed, hollow, economical and resilient fashion forms could be prepared, it would constitute an important contribution to the art. For example, if such highly detailed hollow fashion forms could be made from a durable, resilient material like polyurethane, and if they could be prepared easily and economically, a new improved genre of fashion forms would be at hand.
[0004] Likewise, if other aesthetically unique useful articles could be made from a durable, resilient material like polyurethane, and if they could be prepared easily and economically, a further important new invention would be at hand. Examples of such other types of aesthetically unique useful objects are shelves and other display paraphernalia which have a unique sculpted look. The unique sculpted look of the shelves and other display paraphernalia draws attention to the objects displayed thereon. Yet, sculpting the products on a one-by-one basis is not economically feasible.
[0005] Unfortunately, in the past hollow polyurethane objects have been molded in metallic molds which typically are quite expensive and do not produce products commensurate in detail with conventional solid foam fashion forms or with other highly detailed aesthetically unique useful articles. Interestingly, no one in the past has thought to mold hollow polyurethane products like these in fiberglass molds, because such molds would not be expected to have temperature and other properties necessary for successfully and efficiently molding polyurethane to produce such highly detailed products.
SUMMARY OF THE INVENTION
[0006] This invention consists of a method for making aesthetically unique useful objects like fashion forms, shelves and other display paraphernalia by providing a three-dimensional model of the object, preparing a mold from the model and making a positive form of the model using the mold. Once this is done, a fiberglass mold is made of the positive form, and an appropriate polyurethane resin is prepared and introduced into the fiberglass mold which is rotocast to distribute the polyurethane resin along the inner surface of the fiberglass mold. Typically, this polyurethane resin is permitted to gel, whereupon the mold is opened and the rotocast form removed so that the curing process can continue after it is removed from the form.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The above as well as other objects and advantages of the invention will become apparent from the following detailed description of the preferred embodiments in which reference is made to the accompanying drawings where:
[0008] FIG. 1 is a fiberglass mold of the type used in the method of the present invention;
[0009] FIG. 2 is a fashion form produced in accordance with the method of the present invention using the fiberglass mold of FIG. 1 ;
[0010] FIG. 3 is a perspective view of a tray made in accordance with the method of the present invention;
[0011] FIG. 4 is a perspective view of a shelving unit or etagere comprising a series of circular aesthetically unique shelves supported by a metallic support unit;
[0012] FIG. 5 is a perspective view of another shelving unit with a series of aesthetically unique shelves made in accordance with the present invention; and
[0013] FIGS. 6A-6C illustrate, in plan and cross-sectional views, a series of alternative shelves and other display paraphernalia which have unique sculpted looks which may be made in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0014] As described in some detail below, in accordance with one embodiment of the present invention, a fiberglass mold 10 as illustrated in FIG. 1 is formed from a human model's body. The resulting mold is strikingly detailed and, surprisingly, can be used to mold hollow polyurethane fashion forms as shown in FIG. 2 .
[0015] Fiberglass molds 10 may be prepared as follows. A model is chosen and he/she is dressed in a form-fitting bodysuit. Wetted plaster bandages of the type typically used in casting fractured bones, etc. are wound about the model's limbs and torso, with the bandages pressed into the body curves and crevices, as appropriate. The plaster bandages are permitted to cure and then a seam is formed along the entire perimeter of the model's body, and the cast is pulled away from the model in two halves and a flange for clamping is formed.
[0016] Once removed from the model, the plaster mold halves are cleaned, checked and shellacked and then rejoined, leaving a pour hole at the top. Then, about six-pound density pouring urethane foam is introduced into the plaster bandage mold to make a positive form of the model.
[0017] This positive form is then also cleaned and checked, and then the hollow fiberglass mold 10 , with its two corresponding halves joined at flanges 12 , is made by laying up gelcoat and fiberglass on the surface of the positive urethane foam form of the model. Once the fiberglass mold is completed and ready to be used, its interior surface is coated with a wax release material such as Johnson floor wax. The polyurethane resin is then mixed up, heated and introduced through an inlet into the fiberglass mold which preferably is also preheated. A coloring agent may be added to the mix, if desired. When a resin that should be heated to about 100° F. to 120° F. is used, the mold should be preheated to about 120° F. A coloring agent may be added to the polyurethane if desired. The mold typically does not have to be further heated, because the polyurethane mixture exotherms as it cures, providing continuous heating of the mold.
[0018] The mold containing the polyurethane is then closed up by clamping, placed in a conventional rotocast machine and rotated in accordance with known techniques at an x/y axis speed determined by trial and error to distribute the polyurethane resin along the inner surface of the fiberglass mold. Sufficient polyurethane resin is provided to produce a final fashion form product having a thickness of about from about ⅛ to {fraction (3/16)} inch. Preferably the quantity of resin will be chosen to produce a fashion form with a thickness of about {fraction (3/16)} inch.
[0019] Preferably, the polyurethane is formulated so that it begins to gel in about 3 to 5 minutes after the resin components are mixed together. This may be determined by trial and error. If the gelling time is too long, it would be difficult to produce a satisfactory product because sagging or pulling away from the wall of the mold would occur. If the gelling time is too short, the polyurethane will form clumps before it is able to spread along the surface of the mold.
[0020] When the rotocasting is completed, the mold is allowed to stand for about 15 minutes at room temperature in order to begin the cooling of the fashion form waiting therein. The molded form is still in the green state at this point (not fully cooled or fully cured) which facilitates removal of resin overflow on the form as well as cleaning up form seams, etc. The mold is opened with the form in this green state and the form is removed and allowed to fully cure, preferably at room temperature, over a period of at least 30 minutes. The resulting product 14 , which is shown in FIG. 2 , is strong, highly detailed, resilient and “colored through.” By “colored through”, it is meant that the polyurethane is of the same color throughout so that a scratch of the surface of the form will not stand out due to exposure in the scratch of a differently colored material. Also, the resulting product has some give, but bounces back to its original shape when lightly deformed by pressing the surface of the form.
[0021] The resin used in making the forms is a polyurethane which will have a molecular weight and degree of crosslinking that will give it sufficient hardness and toughness to resist scratching. The molecular weight should also be chosen to insure cure characteristics that will permit the polyurethane resin to be distributed within the mold before any significant curing begins, yet insure that once distributed, the resin cures in a reasonable period of time, and can be removed from the mold. Also, fillers such as fiberglass particles may be introduced into the resin in order to, for example, reduce the cost of the resulting fashion form.
[0022] Commercial polyurethane polymers are typically made by the reaction of a diisocyanate with a diol molecule containing at least two active hydrogens, where an active hydrogen is defined as a hydrogen that can be replaced by sodium. The reaction, which is self-sustaining and without byproduct formation, is a relatively easily controlled polymerization which is often named polyaddition, and may be represented by the reaction:
[0023] One commercial polyurethane resin that can be used in the practice of the invention is available from BASF Corporation under #11604-1-93-133R. It is a gray liquid with a viscosity of 805 cups at 77° F. (25° C.) and a density of 1.065 g/cc (8.83 lb./gal. at 77° F.). Other polyurethane resins that have appropriate cure characteristics and produce a polyurethane with the desired hardness and toughness can be used in the practice of the invention. Such resins can be readily identified by those skilled in the art and, where necessary, fine-tuned by simple trial and error testing.
[0024] Other aesthetically unique useful objects may be made in the same way as the fashion mold described above. Thus, for example, a tray 16 ( FIG. 3 ), or the individual shelves 18 of the four-shelve etagere 20 of FIG. 4 or the three shelves 22 of the etagere 24 of FIG. 5 may be made by first sculpting the individual tray or shelf from clay and permitting the clay to harden. Then, this clay model is covered by wetted plaster bandages, which are pressed into the curves and crevices of the clay model. The plaster bandages are permitted to cure and then a seam is formed along the perimeter of the model, and the cast is pulled away from the model in two halves.
[0025] Once removed from the clay model, the plaster molds are cleaned, checked and shellacked. They are then rejoined by screw clamps along the flanges and with duct tape, leaving a pour hole in the top. Then poured urethane foam is introduced into the mold to make a positive form.
[0026] The positive form of the shelf (or tray, etc.) is cleaned and checked, and a fiberglass mold is made by laying up gel coat and fiberglass. A flange is formed on the cast for later clamping. Once the fiberglass mold is completed, its interior surface is coated with a wax release material. Then, the polyurethane resin is mixed up (including a coloring agent, if desired), heated and introduced through an inlet in the fiberglass mold which preferably is also preheated.
[0027] Next, the mold containing the polyurethane is closed up by clamping, placed in a conventional rotocast machine and rotated to distribute the polyurethane resin along the inner surface of the fiberglass mold. Sufficient polyurethane resin is provided to produce a final shelf (or tray, etc.) having a thickness of about ⅛-{fraction (3/16)} inches. When the rotocasting is completed, the mold is allowed to stand for about 15 minutes at room temperature to begin the cooling process. The mold is then opened with the form in the green state and the form is removed and allowed to slowly cure at room temperature.
[0028] As noted earlier, the present method makes it possible to simply and economically produce hollow polyurethane shelves and other display paraphernalia which have a unique sculpted look. Examples of such products are illustrated in FIGS. 6A-6C . For example, a shelf 30 is shown with a square central cavity 32 within a round bullnose profile 34 having debossed elliptical shapes 36 on its surface. Shelf 38 is a generally square shape with flutes 40 along its periphery and a central inset square cavity 42 . The remaining shelf designs are illustrative of other shelf designs which may be used.
[0029] Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
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A method of molding unique hollow polyurethane objects by providing a model of the object, preparing a fiberglass mold of the model, preparing and introducing a polyurethane resin into the fiberglass mold, and rotocasting to distribute the polyurethane resin along the inner surfaces of the fiberglass mold.
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FIELD OF THE INVENTION
[0001] The present invention relates generally to assay analyzing systems and, more particularly, concerns a system and method for creating digital images of randomly arranged specimens (e.g. beads within gels, colonies within petri dishes) or specimens arranged in regular arrays (e.g. wells in plastic plates, dots spotted onto membranes). The invention is capable of creating digital images and performing automated analyses of specimens which emit very low levels of fluorescence, chemiluminescence, or bioluminescence. More particularly, the invention is designed for the analysis of luminance arising from assays within well plates and gel media, and on membranes, glass, microfabricated devices, or other supports.
BACKGROUND OF THE INVENTION
Types of Assays
[0002] Many chemical and molecular biological assays are designed so that changes in the absorbance, transmission, or emission of light reflect reactions within the specimen. Therefore, instruments used to quantify these assays must detect alterations in luminance.
[0003] Wells. Some assays are conducted within discrete flasks or vials, while others are performed within plastic plates fabricated to contain a number of regularly spaced wells. “Well plate” assays are higher in throughput and lower in cost than similar assays in discrete containers. Standard well plates contain 96 wells in an area of 8×12 cm. The trend is to higher numbers of wells, within the same plate size. Today's highest commercial density is 384 wells. Very high density arrays of small wells (microwells, e.g. thousands/plate with a fill volume of less than 1 ul/well) are under development, and will become commercially available as microwell filling and detection technologies mature.
[0004] Dot blots. Grids of small dots (reactive sites) are placed onto flat support membranes or slips of treated glass. A high density grid can contain many thousands of discrete dots. Grid assays usually involve hybridization with synthetic oligonucleotides, to look for genes containing specific sequences, or to determine the degree to which a particular gene is active. Applications include library screening, sequencing by hybridization, diagnosis by hybridization, and studies of gene expression. High density grids provide the potential for very high throughput at low cost, if analyzing the grids can be made simple and reliable. Therefore, considerable commercial attention is directed at companies developing technology for creating, detecting, and analyzing high density arrays of genomic sequences.
[0005] Combinatorial assays. Some assays involve small particles (typically beads coated with compounds) which act as the reactive sites. There might be many thousands of beads, each coated with a different compound (e.g. molecular variants of an enzyme) from a combinatorial library. These beads are exposed to a substance of interest (e.g. a cloned receptor) in wells, or in a gel matrix. The beads which interact with the target substance are identified by fluorescence emission or absorption in the region around each bead. Beads which interact are surrounded by faint areas of altered luminance. Very sensitive detectors are required to identify the subtle alterations in luminance around the beads that interact with the target.
[0006] Electrophoretic separations. A solubilized sample is applied to a matrix, and an electrical potential is applied across the matrix. Because proteins or nucleic acids with different amino acid or nucleotide sequences each have a characteristic electrostatic charge and molecular size, components within the sample are separated by differences in the movement velocities with which they respond to the potential.
[0007] The separated components are visualized using isotopic, fluorescent, or luminescent labels. In many cases (e.g. chemiluminescence), the luminance from the specimen is very dim.
[0008] Assays which occur within a regularly spaced array of active sites (wells, dot blots within a grid) can be referred to as fixed format assays. Assays which involve specimens that are irregularly distributed within a gel or blot matrix can be termed free format assays.
[0009] Fixed format assays are usually performed without imaging. In contrast, free format assays require the use of image analysis systems which can detect and quantify reactions at any position within an image.
[0010] Instruments designed for fixed format assays generally lack imaging capabilities, and have not been applied to free formats. Similarly, very few imaging instruments designed for free formats have been applied to wells, and other fixed format targets.
Nonimaging Counting Systems
[0011] Nonimaging counting systems (liquid scintillation counters, luminometers, fluorescence polarization instruments, etc.) are essentially light meters. They use photomultipliers (PMTs) or light sensing diodes to detect alterations in the transmission or emission of light within wells. Like a light meter, these systems integrate the light output from each well into a single data point. They provide no information about spatial variations within the well, nor do they allow for variation in the packing density or positioning of active sites.
[0012] Each PMT reads one well at a time, and only a limited number of PMTs can be built into a counting system (12 is the maximum in existing counting systems). Though the limited number of PMTs means that a only few wells are read at a time, an array of wells can be analyzed by moving the PMT detector assembly many times.
[0013] The major advantages of nonimaging counting systems are that they are a “push-button” technology (easy to use), and that the technology is mature. Therefore, many such instruments are commercially available, and their performance is well-characterized.
[0014] The major disadvantages of counting systems are:
[0015] a. Limited flexibility- few instruments can cope with 384 wells, and higher density arrays of fluorescent or luminescent specimens are out of the question.
[0016] b. Fixed format only- designed as well or vial readers, and cannot read specimens in free format.
[0017] c. Slow with dim assays- although scanning a few wells at a time can be very fast when light is plentiful, dim assays require longer counting times at each position within the scan. As there are many positions to be scanned, this can decrease throughput.
[0018] In summary, non-imaging counting systems are inflexible and offer limited throughput with some specimens.
Scanning Imagers
[0019] For flat specimens, an alternative to nonimaging counting is a scanning imager. Scanning imagers, such as the Molecular Dynamics (MD) Storm, MD FluorImager, or Hitachi FMBIO pass a laser or other light beam over the specimen, to excite fluorescence or reflectance in a point-by-point or line-by-line fashion. Confocal optics can be used to minimize out of focus fluorescence (e.g. the Biomedical Photometrics MACRoscope), at a sacrifice in speed and sensitivity. With all of these devices, an image is constructed over time by accumulating the points or lines in serial fashion.
[0020] Scanning imagers are usually applied to gels and blots, where they offer convenient operation. A specimen is inserted and, with minimal user interaction (there is no focusing, adjusting of illumination, etc.), the scan proceeds and an image is available. Like the nonimaging counting system, the scanning imager is usually a push-button technology. This ease of use and reasonably good performance has lead to an increasing acceptance of scanning imagers in gel and blot analyses.
[0021] Scanning imagers have four major shortcomings:
[0022] a. Slow scanning. The beam and detector assembly must be passed over the entire specimen, reading data at each point in the scan. Scanning a small specimen could easily take 5-10 minutes. A large specimen might take ½ scan. This slow scan limits throughput, and complicates the quantification of assays that change during the scan process.
[0023] b. Limited number of wavelengths. A limited number of fluorescence excitation wavelengths is provided by the optics. Therefore, only a limited number of assay methods can be used.
[0024] c. Low sensitivity. Most scanning imagers exhibit lower sensitivity than a state of the art area imager.
[0025] d. Not appropriate for luminescence. Scanning imagers require a bright signal, resulting from the application of a beam of light to the specimen. Therefore, specimens emitting dim endogenous luminescence (e.g. reactions involving luciferase or luminol) cannot be imaged.
[0026] e. Not appropriate for wells. Only flat specimens can be imaged. A limited number of confocal instruments can perform optical sectioning and then reconstruct the sections into a focused thick image.
Area Imaging
[0027] An area imaging system places the entire specimen onto a detector plane at one time. There is no need to move PMTs or to scan a laser, because the camera images the entire specimen onto many small detector elements (usually CCDs), in parallel. The parallel acquisition phase is followed by a reading out of the entire image from the detector. Readout is a serial process, but is relatively fast, with rates ranging from thousands to millions of pixels/second.
[0028] Area imaging systems offer some very attractive potential advantages.
[0029] a. Because the entire specimen is imaged at once, the detection process can be very quick.
[0030] b. Given an appropriate illumination system, any excitation wavelength can be applied.
[0031] c. Luminescence reactions (emitting light without incident illumination) can be imaged, including both flash and glow bioluminescence or chemiluminescence.
[0032] d. Free or fixed format specimens can be imaged.
[0033] Luminescence imaging is more easily implemented, in that illumination does not have to be applied. However, most luminescence reactions are quite dim, and this can make extreme demands upon existing area imaging technology. The standard strategy is to use sensitive, cooled scientific grade CCD cameras for these types of specimens. However, in the absence of the present invention, integrating cameras will fail to image many luminescent specimens. Therefore, the present invention can image specimens that other systems cannot.
[0034] Typical prior art systems apply area imaging to luminescent assays on flat membranes and luminescent assays in wells. Standard camera lenses are always used. The results of well imaging are flawed, in that there is no correction for parallax error.
[0035] There is more extensive prior art regarding use of area imaging in fluorescence. Fluorescence microscopy (see Brooker et al. U.S. Pat. No. 5,332,905) and routine gel/blot imaging are the most common applications. Prior art in microscopy-has little relevance, as no provision is made for imaging large specimen areas.
[0036] The existing art relating to macro specimens is dominated by low cost commercial systems for routine gel/blot fluorescence. These systems can image large, bright areas using standard integrating CCD cameras. However, they have major disadvantages:
[0037] a. Limited to the wavelengths emitted by gas discharge lamps. Typically some combination of UVA, UVB, UVC, and/or white light lamps is provided. Other wavelengths cannot be obtained.
[0038] b. Wavelengths cannot be altered during an assay. If the illumination must be changed during the assay (e.g. as for calcium measurement with fura-2), the devices cannot be adapted.
[0039] c. Insensitive to small alterations in fluorescence. Transillumination comes from directly below the specimen into the detector optics. Therefore, even very good filters fail to remove all of the direct illumination, and this creates a high background of nonspecific illumination. Small alterations in fluorescence (typical of many assays) are lost within the nonspecific background.
[0040] d. Inefficient cameras and lenses. A very few systems use high-performance cameras. Even these few systems use standard CCTV or photographic lenses, which limit their application to bright specimens.
[0041] e. Parallax error precludes accurate well imaging. As fast, telecentric lenses have not been available, these systems exhibit parallax error when imaging wells.
[0042] Novel features of the present invention minimize the disadvantages of known macro fluorescence systems. These novel features include:
[0043] a. Illumination wavelengths may be selected without regard to the peak(s) of a gas discharge lamp or laser.
[0044] b. Using a computer-controlled filter wheel or other device, illumination may be altered during an assay,
[0045] c. Small alterations in fluorescence emission can be detected. Because fluorescence illumination comes via epi-illumination, or from a dorsal or lateral source, direct excitation illumination does not enter the optics. This renders the nonspecific background as low as possible.
[0046] d. Very efficient camera and lens system allow use with dim specimens.
[0047] e. Unique telecentric lens is both very fast, and removes-parallax error so well plate assays are accurate.
[0048] A primary advantage of the present invention is its fast, telecentric lens, which can image an entire well plate at once, and which can provide efficient epi-illumination to transparent or opaque specimens. Fiber optic coupling to the specimen can be used instead of lens coupling. For example, a fiber optic lens has been used with an image intensified CCD camera run in photon counting mode for analyses of data in fixed or free formats. This approach yields good sensitivity, but has the following major disadvantages:
[0049] a. Although it is suggested that the system could be used with fluorescent specimens, it would be limited to specimens that are transilluminated, because there is no place to insert an epi-illumination mechanism. Therefore, the fiber lens system would have degraded sensitivity, and could not be used with opaque specimens. Many specimens are opaque (e.g. many well plates, nylon membranes).
[0050] b. Well plates are 8×12 cm. Image forming fiber optics of this size are very difficult and expensive to construct. Therefore, the specimen would have to be acquired as a number of small images, which would then be reassembled to show the entire specimen.
[0051] This multiple acquisition would preclude use of the device with assays which change over time.
[0052] An area imaging analysis system (LUANA) is disclosed by D. Neri et al. (“Multipurpose High Sensitivity Luminescence Analyzer”, Biotechniques 20:708-713, 1996), which uses a cooled CCD, side-mounted fiber optic illuminator, and an excitation filter wheel to achieve some functions similar to the present invention (selection of wavelengths, area imaging). However, LUANA uses a side-mounted fiber optic, which is widely used in laboratory-built systems, and creates problems that are overcome by the present invention. Specifically, use of a side-mounted fiber optic provides very uneven illumination, particularly when used with wells. The epi- and transillumination systems of the present invention provide even illumination of both flat specimens and wells. Further, in LUANA, parallax would preclude imaging of assays in wells.
[0053] Another system (Fluorescence Imaging Plate Reader-FLIPR of NovelTech Inc., Ann Arbor Mich.) uses an area CCD to detect fluorescence within 96 well plates. This device is a nonimaging counting system, and uses the area CCD instead of multiple PMTs. To achieve reasonable sensitivity, it runs in 96 well format and bins all pixels within each well into a single value. The device is not applicable to luminescence imaging, free format imaging, or higher density well formulations and is very costly.
[0054] There is extensive prior art in the use of imaging to detect assays incorporated within microfabricated devices (e.g. “genosensors”). Some genosensors use scanning imagers, and detect emitted light with a scanning photomultiplier. Others use area CCDs to detect alterations at assay sites fabricated directly onto the CCD, or onto a coverslip that can be placed on the CCD. Genosensors have great potential when fixed targets are defined. For example, a chip is fabricated that looks for a specific sequence of genomic information, and this chip is used to screen large numbers of blood samples. While highly efficient for its designed sequence, the chip has to contain a great number of active sites if it is to be useful for screening a variety of sequences. Fabrication of chips with many thousands of sites is costly and difficult. Therefore, the first generation of genosensors will be applied to screening for very specific sequences of nucleotides.
[0055] The inflexibility of the microfabricated device contrasts with the present invention, which does not require microfabrication of the assay substrate. Instead, the present invention permits assays to be conducted in wells, membranes, silicalized slides, or other environments. Almost any reaction may be quantified. Thus, the present invention could be used as an alternative technology to microfabrication. Because the present invention is flexible, and allows almost any chemistry to be assayed, it can be used for all phases of assay development. These include prototyping, and mass screening. The invention therefore provides an alternative to microfabrication, when microfabrication is not feasible or cost-effective.
[0056] Each of the prior art references discussed above treats some aspect of imaging assays. However, the prior art does not address all of the major problems in imaging large specimens at low light levels. The major problems in low light, macro imaging are:
[0057] a. very high detector sensitivity required;
[0058] b. flexible, monochromatic illumination of large areas is required;
[0059] c. parallax error must be avoided; and
[0060] d. more reliable procedures are needed to find and quantify targets.
[0061] Broadly, it is an object of the present invention to provide an imaging system for assays which overcomes the shortcomings of prior art systems. It is specifically intended to provide a complete system for the area imaging of assays in wells and on membranes. It is specifically contemplated that the invention provide a complete system for the area imaging of chemiluminescent, fluorescent, chemifluorescent, bioluminescent, or other nonisotopic hybridization assays, including high density dot blot arrays.
[0062] It is another object of the invention to image chemiluminescent, fluorescent, chemifluorescent, bioluminescent, or other nonisotopic assays, including combinatorial assays, in free format.
[0063] It is an object of the invention to provide software for digital deconvolution of the fluorescence image data. Application of the software decreases flare and out of focus information.
[0064] It is also an object of the present invention to provide a method and system for imaging assays which are flexible, reliable and efficient in use, particularly with low level emissions.
[0065] The present invention provides synergistic combination of detector, lens, imaging system, and illumination technologies which makes it able to image the types of specimens previously acquired with nonimaging counters and scanning imagers. In particular, it can be used with fixed or free formats, and with wells or flat specimens. It is able to detect fluorescence, luminescence, or transmission of light.
[0066] The features of the invention include that it detects and quantifies large arrays of regularly spaced targets, that it detects and quantifies targets that are not arranged in regular arrays, and that it performs automated analyses of any number of regularly spaced specimens, from small numbers of large wells to large numbers of very small wells or dot blots.
[0067] It is another feature of the invention to provide an area illumination system that: can deliver homogenous monochromatic excitation to an entire well plate or similarly sized specimen, using standard and low cost interference filters to select the excitation wavelength; and can deliver varying wavelengths of homogenous monochromatic excitation to an entire well plate or similarly sized specimen, under computer control.
[0068] A system embodying the invention provides a lens designed specifically for assays in the well plate format. This lens is very efficient at transferring photons from the specimen to the CCD array (is fast), preferably contains an epi-illumination system, and can be used with very dim specimens. The lens is also telecentric. A telecentric lens has the property that it peers directly into all points within a well plate, and does not exhibit the parallax error that is characteristic of standard lenses.
[0069] A preferred system provides a telecentric and fast lens that generates an even field of epi-illumination, when required. The lens is equipped with an internal fiber optic illumination system, that does not require a dichroic mirror. Preferably, the lens is constructed to accept an internal interference filter used as a barrier filter. Light rays passing through the lens are almost parallel when they strike the barrier filter, so that the filter operates at its specified wavelength and bandwidth tolerance.
[0070] It is a feature of the invention that it provides high light gathering efficiency, whether used with a fast telecenric lens, or standard photographic lenses.
[0071] A preferred system provides a CCD area array camera that has high quantum efficiency (approximately 80%), and high sensitivity (16 bit precision), so that most specimens can be detected by integration without intensification. Preferably, the system has an integrating, cooled CCD camera which has coupled thereto an optional image intensifier. In an embodiment intended for extremely low light levels, incident illumination from the specimen is amplified by the intensifier, and the amplified light is accumulated onto the integrating camera over an integration period. At the end of the integration period, the camera is read out to a dedicated controller or imaging apparatus to reproduce the light image. Multiple exposures may be used to increase the dynamic range of the camera. A light-tight specimen chamber is provided, to which all illumination and detection components may be mounted, and which contains the specimens.
[0072] A system in accordance with the invention may incorporate a translation stage (optional), that may be housed within the light-tight chamber and used to move large specimens (e.g. 22×22 cm membranes) past the optical system. The invention controls the stage motion through software, and that creates a single composite image from the multiple “tiles” acquired with the translation stage.
[0073] Preferably, the invention provides software control that corrects the shading, geometric distortion, defocus, and noise errors inherent to the camera and lens system; and that removes as much nonspecific fluorescence as possible, using multiple images created with different excitation filters.
[0074] In particular, the invention provides software to deconvolve images from a single focal plane, using optical characteristics previously measured from the lens and detector system. It should be appreciated that data from multiple focal planes may also be deconvolved.
[0075] While the preferred embodiment of the invention uses a high-precision, cooled CCD camera, if cost is a major factor, the present invention could be constructed using lower cost integrating cameras. In this case, shorter integration periods can be achieved, with a reduction in image quality and ultimate sensitivity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0076] Further objects, features and advantages of the invention will be understood more completely from the following detailed description of a presently preferred, but nonetheless illustrative embodiment, with reference being had to the accompanying drawings, in which:
[0077] [0077]FIG. 1 is a schematic illustration of a system in accordance with a first preferred embodiment (upright) of the invention;
[0078] [0078]FIG. 2 is a schematic illustration, in side view, of the fast, telecentric lens;
[0079] [0079]FIG. 3 is a detailed illustration of the optical and mechanical components of the lens and the emission filter holder;
[0080] [0080]FIG. 4 is a schematic diagram illustrating a second embodiment of a system in accordance with the invention useful for extreme low light applications, which has an intensifier mounted between the lens and the CCD camera;
[0081] [0081]FIG. 5 is a schematic illustration of the intensifier;
[0082] [0082]FIG. 6 is a schematic illustration of the diffuse illumination plate in side view, showing how discrete fiber bundles from the main bundle are taken to locations within the rectangular fiber holder;
[0083] [0083]FIG. 7 is a schematic illustration of the diffuse illumination plate in top view, showing how discrete fiber bundles from the main bundle are taken to an array of channels within the fiber holder;
[0084] [0084]FIG. 8 is schematic diagram of the CCD camera;
[0085] [0085]FIGS. 9A and 9B, collectively referred to below as FIG. 9, represent a flow chart illustrating the method utilized for image acquisition and analysis in accordance with the present invention; and
[0086] [0086]FIG. 10 is a flow chart illustrating the method utilized for locating targets in the process of FIG. 9.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0087] Turning now to the details of the drawings, FIG. 1 is a schematic diagram illustrating a preferred embodiment of an imaging system 1 in accordance with the present invention. System 1 broadly comprises an illumination subsystem 10 , an imaging subsystem 12 provided in an housing 14 , and a control subsystem 16 . The imaging subsystem 12 comprises a CCD camera subsystem 18 housed within a camera chamber 20 of housing 14 and a lens subassembly 22 extending between camera chamber 20 and a specimen chamber 24 . In operation, illumination subsystem 10 provides the necessary light energy to be applied to the specimen within chamber 24 . Light energy emitted by the specimen is transmitted through lens subsystem 22 to camera I 8 , where an image is formed and transmitted to the control subsystem 16 for processing. Control subsystem 16 comprises a camera control unit 26 , which is a conventional unit matched to the particular camera 18 and a computer 28 which is programmed to control unit 26 and to receive data from camera 18 , in order to achieve unique control and processing in accordance with the present invention.
[0088] The light source for the illumination subsystem 10 is preferably an arc lamp 30 . Light from lamp 30 is conducted via a liquid light guide 32 to the optical coupler or filter wheel 34 . The liquid light guide 32 is advantageous in that it transmits in the UV range, and in that it acts to diffuse the input illumination more than a fiber optic would do.
[0089] The optical coupler 34 contains a conventional filter holder (not shown) for standard, one inch diameter interference filters. In the preferred configuration, a computer controlled filter wheel is used instead of the optical coupler. The filter wheel can contain a number of filters, which can be rapidly changed under computer direction.
[0090] A fiber optic bundle 36 carries illumination from the optic coupler or filter wheel 34 to within the light-tight specimen chamber 24 . The bundle 36 passes through a baffle 38 , which allows it to move up and down during focusing of the specimen holder. Alternatively, the fiber optic bundle 40 from the epi-illumination ring light in lens 22 may be connected to the optical coupler 34 .
[0091] Three forms of illumination system are described, each fed by a discrete fiber bundle. These are a transilluminating plate ( 42 ), a ring light external to the lens (not shown), and a ring light 44 internal to the lens ( 22 ) that performs epi-illumination.
[0092] The transillumination plate is a rectangular chamber 50 (see FIGS. 6 and 7), within which the discrete fibers 52 from bundle 51 are separated and rotated by 90 degrees so that they point laterally, towards the specimen. The fibers 52 are distributed within the chamber in such a way that they minimize shading within the illumination pattern. To this end, a larger number of fibers lie in the peripherally outward portions of the chamber than lie at its center.
[0093] The rectangular chamber 50 contains a diffusing screen 54 , and a quartz glass diffusing plate 56 . These diffusing elements take as their input the discrete points of light from the fibers 52 , and create a homogenous illumination over the surface of the plate 56 . The chamber 50 may also contain a dark field stop, to allow light to enter the specimen from the side.
[0094] The external ring light consists of a ring of optical fibers aligned with the axis of the lens, with a hole in the center large enough to encircle the lens 22 . The working distance of the ring light is matched to the focus distance of the lens 22 .
[0095] The internal ring light 44 consists of a ring of optical fibers, mounted within and axially aligned with the body of the telecentric lens 22 , and behind its front lens element. A diffuser, polarizer, or other circular element may be placed at the front of the fiber ring 44 .
[0096] The specimen well plate is carried within a holder 58 (FIG. 6) that is mounted to the fiber optic chamber 50 . The holder 58 grips the well plate at its edges. The bottom of the holder 58 is empty, so as not to impede viewing of the wells. The holder 58 is mounted to a jack, which moves it in the vertical dimension. By adjusting the jack 60 , the holder 58 moves relative to the lens 22 and the specimen is focused.
[0097] The lens 22 is a fast, telecentric lens. The lens contains an emission filter slot 62 , which accepts three inch diameter interference filters for fluorescence imaging. It contains an internal fiber optic ring light 44 , positioned behind the front lens element. The lens 22 is mounted to the camera chamber by a flange 64 (see FIG. 2) at its middle. The back of the lens projects into the camera chamber 20 , providing ready access to the emission filter slot 62 without disturbing the specimen. The front of the lens projects into the specimen chamber 24 .
[0098] The cooled CCD camera 18 is mounted directly to the lens. Because the camera has its own chamber 20 , there is no need for concern regarding light leakage around the cooling, power and data cables that exit the chamber to the camera control unit.
[0099] All control, imaging, and analysis functions are resident within the computer 28 .
Illumination Subsystem
[0100] The standard technology for monochromatic area illumination is to use gas discharge illuminators (e.g. UV light boxes), which can deliver about 5000 uW/cm 2 of surface at the emission peaks (usually mercury). The lamps are coated with a filter that limits emission to a specific peak. Although fairly bright, gas discharge lamps are limited in wavelength to the peaks emitted by the excited gas within the lamp.
[0101] Other than gas discharge lamps, very few descriptions of area illumination exist. The major problems are selection of wavelength, and that direct entrance of the illuminating beam into the collection optics degrades sensitivity. To avoid this, light can be delivered from above, from the side, or via dark field or refraction into the specimen. All of these techniques have severe limitations. Side-mounted fiber optic illuminators are uneven. They are also unsuited to wells or other non-flat specimens, because light enters the specimen at an angle and fails to penetrate deep targets. Refractive or dark field illuminators require special optical components at the well plate, and cannot be used with opaque specimens.
[0102] A more flexible area illumination system would use a broad-band illumination source, and would allow any wavelength of monochromatic illumination to be selected by precision filters (usually interference filters). Filters are preferred, because variable monochromators or low cost tunable lasers lack sufficient light output when diffused over large areas.
[0103] Mercury or xenon arc lamps are often selected for filter-based monochromatic excitation. The advantage of an arc lamp is that its output can be made into a narrow beam that can be passed through a small and readily available interference filter, before being spread over the entire surface of the specimen. Either a lens or fiber optic may be used to transmit the monochromatic light from the filter to the specimen.
[0104] The present invention is much more flexible than any previous device. It applies diffuse transillumination (through the specimen), dorsal illumination (via ring light or other source), or epi-illumination (through the lens) to the entire surface of the specimen. Epi-illumination is preferred, because it usually results in lower backgrounds, broader dynamic range, and more linear fluorescence response under real-world conditions. The ability to deliver large area monochromatic epi-illumination is one critical factor that sets the present invention apart from prior art.
[0105] The present invention addresses three main problems in illumination delivery.
[0106] a. Filter availability-Close-tolerance filters (e.g. a 10 nm bandwidth filter), which are readily available in small sizes, are not available for large areas of illumination. This problem is overcome by use of standard interference filters.
[0107] b. Illumination delivery-Application of even, monochromatic, and selectable illumination over an 8×12 cm area is a feature of the present invention. An optical coupler or computer-controlled filter wheel accepts standard interference filters, and is used to select wavelengths. The optical coupler or wheel may be attached to a specially designed fiber optic plate for transillumination, to a fiber optic ring or panel light for dorsal illumination, or to a fiber optic illumination assembly within the lens, for epi-illumination.
[0108] c. Intensity-The excitation illumination is spread over a large area (typically 96 cm 2 ). As intensity decreases with the square of the illuminated area, the resulting excitation intensity is very low indeed. In many cases, emitted fluorescence will not be detected with standard, scientific-grade cooled CCD cameras. The very sensitive detector of the present invention is capable of imaging the low levels of fluorescence emitted from-large specimens. For the most extreme low light conditions, the present invention incorporates an optional light amplification system that may be inserted between the lens and the CCD camera (see below).
Lens Subassembly
[0109] [0109]FIG. 2 shows the general arrangement of illumination and filter components within the telecentric lens 22 . The lens has mounted within it a fiber optic ring light 44 , which projects monochromatic illumination through the front lens element onto the specimen (leftward in FIG. 2). The focus plane of the ring light is at B, while the focus plane of the entire lens is in front of that point, at A. Placing the focus of the ring light at a point beyond the specimen minimizes specular reflections from the specimen.
[0110] The emission filter slot 62 allows insertion of an interference filter that removes excitation illumination from the incoming rays, leaving only the fluorescence emitted by the specimen.
[0111] [0111]FIG. 3 shows best the optical components of the telecentric, macro lens 22 . The lens has 39 surfaces, and the following characteristics:
Effective focal length 164.436 mm Numerical aperture .443 Magnification 0.25
[0112] Note that light rays are almost parallel at the emission filter slot 62 . This allows the filter to operate at its specified wavelength and bandwidth.
[0113] Although the present invention may be used with any lens, the highest sensitivity is available from its specially designed lens. This lens is fast, telecentric, and incorporates the epi-illumination system appropriate to large specimen formats.
[0114] Epi-illumination is a standard technology in fluorescence microscopy, where small areas are illuminated. The most efficient way to illuminate a small area is to place dichroic beam splitter behind the objective. A dichroic beam splitter or mirror is a partially reflective surface that reflects one wavelength range, while allowing another wavelength range to pass through.
[0115] On a microscope, illumination enters the dichroic mirror from the side. The mirror is angled to reflect the excitation light down through the objective toward the specimen. Fluorescence emitted by the specimen (shifted up in wavelength from excitation) is collected by the objective, which passes it upwards towards the dichroic mirror. The dichroic mirror is transparent to the emission wavelength, so that the light proceeds through the dichroic to the detector plane. A different dichroic is required for each excitation/emission wavelength.
[0116] There are major difficulties in applying the standard form of dichroic-based epi-illumination system to macro imaging.
[0117] a. The dichroic mirror must be at least as large as the objective it must fill. Camera lenses are much larger than microscope objectives, and would need correspondingly large dichroic mirrors. Dichroic mirrors this large are not readily available.
[0118] b. In a fast macro lens, it is critical that the back lens element be mounted as close as possible to the CCD. Any increase in the distance between the rearmost lens and the CCD markedly reduces the working f number and the light-gathering efficiency. Therefore, there is no room for a dichroic to be mounted behind the lens.
[0119] c. In a normal epi-illumination system, the dichroic reflects excitation through the entire lens. For this reason, transmission of excitation illumination is highly subject to the optical characteristics of the glasses used in the lens. Very costly (and difficult to work) quartz glass optics are required for UV epi-illumination. These UV-transparent optics can be constructed in the small sizes needed for a microscope objective, but would be astronomically expensive in the large sizes described for the present invention.
[0120] d. Dichroic beam splitters absorb light. Typically, they are 80-90% efficient.
[0121] A unique property of the present invention is that no dichroic is necessary. The telecentric lens is large, so there is room to install an illumination assembly within its body. The illuminator is mounted so that it shines directly at the front lens element, from behind. This illuminates the specimen, without any need of a reflective dichroic mirror. Any stray excitation illumination that is reflected back through the lens is removed by the emission barrier filter, located posterior to the illumination source.
[0122] Further, the lens is designed so that only one of the fifteen internal lens components resides in front of the internal illuminator. This has the advantage that internal flare and reflections are minimized. Of equal importance, only the front lens needs to be transparent to UV. A single UV-transparent lens is costly, but not prohibitively so.
[0123] The front element of the lens is calculated so as to focus the illumination source beyond the plane of the specimen. The defocus of the illumination source at the specimen plane minimizes reflections. As many well plates are constructed of polished plastic, and tend to generate specular reflections, this is an important feature.
[0124] The lens is highly efficient. The collection F/# of the lens is 4.5. This implies a collection solid angle of 0.03891 sr, and a collection efficiency of 0.03891/4p=0.3096%. The expected transmission value is 0.85-0.90, giving an overall collection efficiency of 0.263-0.279%. In comparison to an F/1.2 photographic lens, the expected improvement with the present lens is about 340%.
[0125] The present lens is telecentric. A telecentric lens is free of parallax error. Images of deep, narrow targets, made with standard lenses, exhibit parallax error. Circular targets at the center of the image are seen as true circles. However, the lens peers into lateral targets at an angle. Therefore, these lateral targets are seen as semilunar shapes. In many cases, one cannot see the bottom of a well at all. A telecentric lens collects parallel rays, over the entire area of a well plate. Thus, it does not peer into any wells at an angle and is free of parallax error.
[0126] A critical advantage of the present lens is that the internal beam is collimated at a position appropriate to the insertion of a barrier filter. That is, the lens is calculated so that rays are nearly parallel, at a point about midway in the lens barrel. The lens accepts an interference filter at this point. The filter serves to remove excitation illumination, and other nonspecific light. The collimated beam at this point is critical, because interference filters must be mounted orthogonal to the incoming illumination. If the incoming illumination is at an angle, the filter exhibits alterations in the wavelengths that it passes. In the present invention, light rays are almost parallel when they strike the filter, yielding the best possible performance.
[0127] The telecentric lens has a fixed field of view (about 14.5 cm diameter, in this case) but, if larger specimens need to be imaged, a motorized translation table may be mounted within the light-tight chamber. The translation table moves the specimen relative to the lens, under computer control. After each motion, a single “tile” is acquired. When the entire specimen has been imaged, all the tiles are recomposed (by the software) into a single large image, retaining telecentricity, freedom from parallax error, and high resolution over its entire surface.
Extreme Low Light Modification
[0128] [0128]FIG. 4 shows a modification to system of FIG. 1, addition of an optional intensifier 70 to provide an alternate system useful for extreme low light imaging. In all other respects the system is essentially identical to that of FIG. 1. The intensifier 70 is mounted between the telecentric lens 22 and the CCD camera 18 .
[0129] [0129]FIG. 5 shows best the intensifier 70 as being of the GEN 3 type, and including a photosensitive cathode 72 , a microchannel plate (MCP) 74 , a phosphor screen 76 , and a vacuum sealed body or enclosure 78 . The fast, telecentric lens 22 (FIGS. 2,3) is placed in front of this assembly 70 . At its output, the lens is focused on an input window of the cathode 72 so as to transfer the specimen image thereto. The photosensitive cathode 72 is selected to emit electrons in proportion to the intensity of light falling upon it. The MCP 74 is positioned within the vacuum sealed body 78 , between the cathode 72 , and the phosphor screen 76 and coupled to the cathode 72 at each end. The MCP 74 is provided with an array of small diameter MCP channels, each of which is coated with gallium arsenide. The electrons emitted from the cathode 72 are accelerated along the MCP channels to the phosphor screen 76 . As the electrons from the cathode are accelerated along the small diameter channels, they strike the coated channel walls to produce additional electrons. As the multiplied electrons leave the MCP channels, they strike the phosphor screen 76 and produce an intensified image of the specimen on an output window. This image is coupled to the CCD 84 element in the camera by a lens 80 .
[0130] It has been found that the use of the Extended Blue GEN 3 image intensifier is advantageous over other types of intensifiers in that the image provided on the output screen is sharper, has less shading error, and has less noise than those produced by GEN 1 and GEN 2 intensifiers. It is to be appreciated, however, that as better intensifier technologies are developed, they may be incorporated into the present system.
[0131] The integrating camera 18 is configured so that the highly amplified image generated on the output window 78 is focused by the intermediate lens 80 onto the CCD element 84 . To image low light specimens, the CCD element 84 of camera 18 integrates for a period. During the integration period, photons from the output window incident to the CCD element 84 are stored as negative charges (the signal) in numerous discrete regions of the CCD element 84 . The amount of charge in each discrete region of the CCD element 84 is accumulated as follows.
[0132] Signal=Incident light×Quantum efficiency x Integration time
[0133] The greater the relative intensity of the incident light coming from the intensifier 70 , the greater the signal stored in the corresponding region of the CCD element 84 .
[0134] For the most extreme low light conditions, as with the scintillation proximity assay, the present invention allows a light amplifier to be inserted between the lens and the CCD camera. In the preferred configuration, this light amplifier is an image intensifier. Intensification, as for example, is disclosed in U.S. Pat. No. 5,204,533 to Simonet, involves the coupling of an image intensifier to a CCD camera. The image intensifier typically includes a photocathode, a phosphor screen, and a microchannel plate (MCP) connected between the photocathode and phosphor screen. Light amplification factors of up to about 90,000 are possible with this type of device.
[0135] With the intensifier inserted into the optical chain, the present invention becomes an image intensified CCD (ICCD) camera. In an ICCD camera, the image is created at three or four planes. At each of these planes, there is some loss of quantum efficiency. Therefore, the image intensifier is operated at high gain to overcome signal losses within the optical chain. At very high gain factors, noise and ionic feedback through the MCP become so severe that further improvement of sensitivity is impossible. Even when run at maximum gain, conventional image intensified CCD cameras are not sensitive enough to image the dimmest specimens.
[0136] Faced with a typical very dim specimen, most ICCD cameras will fail to produce an image, or will produce a very poor image, in which the target will be difficult to discriminate from background, and the true range of target intensities will not be rendered. In the worst cases, the target will be indiscriminable from background.
[0137] Conventional image intensified CCD cameras use an integration period equal to a single television frame. The short integration period allows the intensifier to be used with standard, low-cost video cameras, as for example, are used in the television industry. In other cases, the intensifier is gated, to use very short integration periods (e.g. 1 msec). The use of gating allows the intensifier to be used in a photon counting mode.
[0138] The present invention offers two methods by which intensified light may be used. The preferred method involves continuous integration of the output of the intensifier onto a cooled CCD camera. This method is fast and efficient, but has limited dynamic range. Cooling of the intensifier, or multiple exposures for different times, may be used to improve the dynamic range. A second method involves looking at shorter periods of intensifier output, and photon counting. This method is much slower, but has broad dynamic range. The present invention allows either strategy to be selected, as warranted by the specimen.
[0139] Prior art exists for the use of intensified CCD cameras in well plate assay imaging. Martin and Bronstein (1994) and Roda et al. (1996) discuss use of an intensified CCD camera for the imaging of chemiluminescent specimens. Only bright specimens can be seen. No provisions are made for imaging deep wells without parallax error, or for applying monochromatic excitation to the specimen.
[0140] U.S. Pat. No. 4,922,092 (1990) to Rushbrooke et al. discloses the use of an image intensified CCD camera which is coupled to a special fibre optic lens. The fibre optic lens consists of bundles which transmit light between an array of wells and the input of the intensifier. While the invention disclosed by Rushbrooke is free of parallax, and may be suitable for standard 96 or 384 well plates, it would be incapable of imaging the very high density well arrays addressed by the present invention. Further, the invention disclosed by Rushbrooke lacks illumination capabilities. It is also incapable of imaging specimens in free format, because there is space between the input bundles that is not addressed. By using lens input, as opposed to fiber optics, the present invention allows free format imaging.
[0141] In sum, the present embodiment of the invention allows the use of an optional intensifier placed behind the lens, to detect the most extreme low light specimens. When intensified, the device can be run in continuous integration or photon counting modes.
[0142] With the system shown in FIGS. 4 and 5, only the CCD sensor is cooled. This is sufficient for most purposes. It is to be appreciated however, that the intensifier photocathode 72 could also be cooled, thereby improving the signal to noise ratio of the intensifier. Similarly, the entire photosensitive apparatus (intensifier+CCD) can be cooled. However, cooling the entire photosensitive apparatus has the disadvantage that the efficiency of the phosphor on the fibre optic output window is decreased.
[0143] Although a high quality, scientific grade CCD camera can detect about 50 photoelectrons incident to the CCD (depending on how we set reliability of detection), this is not an accurate indication of performance in imaging luminescent specimens. Real-world performance is complicated by the emission and collection properties of the entire optical chain, as well as by the performance of the CCD camera. Therefore, we need to go beyond the QE of the detector, and examine the transfer efficiency of the entire system.
[0144] Three factors dominate the transfer efficiency (photoelectrons generated/photons emitted) of the detector system. These are the light collection efficiency of the lens, the quantum efficiency of the CCD detector, and the lens transmittance. We can calculate the number of photoelectrons generated as follows:
Npe=τ*φ detector *c.e.*N photons
[0145] where:
[0146] τ is lens transmittance, about 85-90% for our lens
[0147] φ is quantum efficiency of the CCD detector, typically about 35-40%, up to 80% in our case, and
[0148] c.e. is collection efficiency of lens, less than 0.1% for fast photographic lenses, about 1.2% in our case.
[0149] In a typical scientific grade CCD camera system, using the fastest available photographic lens (f1.2), and with a high quality cooled detector, the CCD will generate 1 photoelectron for about 5,000-10,000 photons generated from a point source in the sample.
[0150] The lens of the present invention offers a collection efficiency of about 0.271%. The efficiency of the CCD detector is about double that of other CCDs. The result is that the present invention has the theoretical ability to generate one photoelectron for about 500-1000 photons generated from a point source within the sample. This very high transfer efficiency allows detection of specimens that cannot be imaged with prior art systems.
[0151] In the alternate embodiment of the invention shown in FIGS. 4 and 5, the system incorporates an extended blue type of GEN 3 image intensifier. Other types of intensifiers, although less preferred, may also be used. The three major types of intensifier (GEN 1 , GEN 2 and GEN 3 ) differ in the organization of their components and in the materials of which the components are constructed. In a GEN 1 intensifier, illumination incident to a photocathode results in emissions at a rate proportional to the intensity of the incident signal. The electrons emitted from the photocathode are than accelerated through a high potential electric field, and focused onto a phosphor screen using electrostatic or proximity focusing. The phosphor screen can be the input window to a video camera (as in the silicon intensified target camera), or can be viewed directly. GEN 1 intensifiers suffer from bothersome geometric distortion, and have relatively low quantum efficiency (about 10%).
[0152] The GEN 2 intensifiers, like the GEN 3 , incorporate a MCP into an image tube, between the cathode and an anode. The GEN 2 intensifiers are smaller, lower in noise, and have higher gain than the GEN 1 intensifiers. However their quantum efficiency is fairly low (typically <20%), and they tend to suffer from poor contrast transfer characteristics. In contrast, the GEN 3 intensifier tube has a quantum efficiency of about 30% or higher (needs less gain), and very high intrinsic contrast transfer. With recent versions of the GEN 3 , gain levels are about equal to those of a GEN 2 (ultimate gain level available is about 90,000). Therefore, a GEN 3 intensifier will tend to yield better images than a GEN 2 . Where necessary for reasons of cost or specific design features, other forms of intensifier could be used. Similarly devices with high intrinsic gain (such as electron bombarded back-illuminated CCD sensors) could be used in place of image intensifiers.
[0153] The CCD camera 18 of the present invention could use integration periods locked to a gated power supply in the image intensifier, with the result that the camera could be read out at very short intervals. Using the gating and fast readout feature, and with the intensifier run at highest gain or with a multistage intensifier, the present invention can thereby be operated as a conventional photon counting camera. Thus, the present system can advantageously be used for both direct imaging of faint specimens, or as a photon counting camera by changing its mode of operation from integration to gating.
CCD Camera System
[0154] [0154]FIG. 8 is a schematic representation of the CCD camera 18 . The camera 18 includes a CCD element 84 positioned behind a camera aperture. To reduce dark noise produced by electrons within the CCD, the CCD element 84 is mounted to a heat sink 88 , which in turn is thermally coupled to a Peltier cooling element and liquid circulation system for providing enhanced heat dissipation. The lens is positioned over the aperture to focus the image on the CCD element 84 . The fast, telecentric lens 22 (FIGS. 2 and 3) is mounted directly to the camera body by screws, after removing the photographic lens mount. Similarly, the image intensifier 70 (when present) is mounted directly to the camera body.
[0155] Area imaging systems use CCD arrays to form images. Factors which influence the ability of CCD arrays to detect small numbers of incoming photons include quantum efficiency, readout noise, dark noise, and the small size of most imaging arrays (e.g. 2.25 cm 2 ).
[0156] Quantum efficiency (QE) describes the ability of the photodetector to convert incident photons into electron hole pairs in the CCD. Consumer-grade CCDs typically exhibit QE of about 12-15%. Standard, scientific grade cooled CCD cameras exhibit QE of about 40%. A very limited number of thinned, back-illuminated CCDs can achieve QE of as high as 80% at peak detection wavelengths.
[0157] Readout noise originates in the output preamplifier of the CCD, which measures the small changes in voltage produced each time the charge content of one or more CCD elements is transferred to it. Readout noise is directly related to the readout rate, and is decreased by use of slow readout.
[0158] Dark noise is produced by thermally generated charges in the CCD. By increasing the background level, dark noise decreases dynamic range. The constant dark noise level can be subtracted from the image, but dark noise also has a random noise component which cannot be subtracted. This component adds to the noise level of the detector. Dark noise is decreased by cooling the CCD.
[0159] The size of the CCD element is related to its ability to store photoelectrons (known as the well capacity) and, hence, its dynamic range. The larger each CCD element in the array, the larger the full well capacity and dynamic range of that element. A broad dynamic range allows the detector to be used for longer exposure times, without saturation, and this enhances the detection of very small signals. Further, the signal to noise performance of larger elements is inherently higher than that of smaller elements. Most area imaging systems use relatively small CCDs. This results in limited resolution for devices in which the discrete CCD elements are large, and limited dynamic range for devices in which the discrete CCD elements are small. Devices with limited dynamic range cannot achieve 16 bit precision, and must be used with relatively bright specimens (e.g. fluorescence microscopy, UV gels, very bright chemiluminescence).
[0160] The present invention incorporates a CCD system which is designed to minimize all of the problems just described. The CCD array is unusually large (6.25 cm 2 ) and efficient (about 80% quantum efficient). The result is very high detector sensitivity with broad dynamic range (true 16 bit). The preferred support electronics include a high-precision digitizer, with minimal readout noise. Preferably, the camera is cooled to minimize dark noise.
[0161] An electro-mechanical shutter mechanism is additionally provided within the camera, for limiting the exposure of the image on the CCD element. Preferably the camera is a thinned, back-illuminated 1024×1024 pixel black and white camera with asynchronous reset capability, and high quantum efficiency. The camera provides a 16-bit digital signal output via digitization circuitry mounted within the camera control unit, and an interface card mounted within the computer. Data from the CCD are digitized by the camera control unit at the rate of 200,000 pixels/second, and transferred directly to the computer memory.
[0162] Following the integration period, the CCD camera accepts a trigger pulse from the computer to initiate closure of the electromechanical shutter. With the shutter closed, the image is transferred from the CCD to the internal frame buffer of the computer.
[0163] Although this camera could be used without cooling the CCD element, extended periods of integration are achieved by using a CCD camera with an integral cooling element. The effectiveness of integration is limited by the degree of cooling. With a non-refrigerated liquid cooling device, sensor temperatures of about −50° C. (below ambient) can be achieved. At this temperature, dark noise accumulates at a rate of about 7-10 electrons/second. This type of cooling has the advantage of low cost and easy implementation.
[0164] It is to be appreciated, however, that longer periods of integration are possible if refrigerated liquid or cryogenic cooling are employed.
Control Subsystem
[0165] The control subsystem 16 comprises, control unit 26 and computer 28 . Camera control unit is a computer controllable unit provided by the manufacturer of camera 18 to control the camera. Computer 28 is preferably a conventional computer running in the Windows® environment and is programmed to achieve image acquisition and analysis in accordance with the present invention.
[0166] Camera-based imaging systems lack the sort of push-button operation that is typical of counting or scanning systems. Focusing the camera, adjusting exposure time, and so forth, can all be inconvenient.
[0167] In fact, imaging is inherently more complex than counting single targets within wells. Nonimaging counting systems have a relatively easy task. They only need to control the scanning process, control internal calibration, and create a small array of data points representing each well. The sequence of steps might be as follows.
[0168] a. Calibrate detector against internal standard.
[0169] b. Illuminate one well
[0170] c. Position a PMT over the illuminated well.
[0171] d. Read well.
[0172] e. Transfer data to spreadsheet.
[0173] f. Illuminate next well and repeat.
[0174] An area imaging system has a much more difficult task. Imaging a well plate might include the following requirements.
[0175] a. Provide adequate illumination over the entire plate.
[0176] b. Control a high performance camera.
[0177] c. Store geometric and density correction factors.
[0178] d. Image specimen.
[0179] e. Correct geometric and density variation.
[0180] f. If necessary, calibrate image to standards within the specimen.
[0181] g. Locate each well and quantify intensity.
[0182] h. Transfer data to spreadsheet.
[0183] These tasks can only be performed if the imaging system is equipped with software that performs functions b-h, above. The present invention incorporates such software.
[0184] In particular, one aspect of the present invention is software which corrects for nonspecific background fluorescence by using two images. The first image is made with an excitation filter that excites as little specific fluorescence as possible, while exciting nonspecific fluorescence. The second image is made with an excitation filter that excites specific fluorescence as much as possible, and as little nonspecific fluorescence as possible. An optimal specific fluorescence image is made by subtracting the nonspecific image from the specific image.
[0185] [0185]FIG. 9 is a flow chart illustrating the primary process performed by computer 28 in controlling the system 1 and acquiring data therefrom. After initiation of the process, an image of the specimen is acquired at block 200 using camera 18 . Known processes exist for acquiring bias images of a specimen. Such bias images take into account all significant distortions and errors introduced by the system itself when an image is taken. Utilizing one of the known methods, a bias image for the specimen is acquired at step 202 .
[0186] At Step 204 , a non-specific image is acquired. This image determines the contribution of non-specimen components, such as the support substrate, to the image. This step is indicated as optional, since it would only be performed in the event that the specimen had to be illuminated in order to acquire the specimen image, in which event some light would also be reflected from non-specimen elements. On the other hand, if the specimen were the source of the light for the image (as in chemiluminescence), the non-specific image would not be acquired. Similarly, the step at block 206 is optional, since it involves obtaining a non-specific bias image.
[0187] At block 208 , the specimen bias image is removed or subtracted from the specimen image, and at block 210 the non-specific bias image is subtracted from the non-specific image. This results in two images in which bias effects have been compensated. At step 212 , the compensated non-specific image is removed from the compensated specimen image to produce a working image in which the effects of the specimen are isolated. Those skilled in the art will appreciate that if steps 204 and 206 were not performed, steps 210 and 212 would also not be performed.
[0188] Following bias removal, various other corrections are provided (e.g. for geometric warping originating in the lens), using known processes.
[0189] At step 214 , the operator inputs to the computer the nominal “grid” spacing and “probe template”. The grid spacing is the nominal center-to-center spacing of specimen samples on the substrate. The “probe template” is the nominal definition of a single target (e.g. in terms of shape and area) corresponding to one dot on a membrane, one well in a plate, or similar target. Typically the probe template is a circular area, and there is one probe template for each target in the specimen. A grid is composed of a matrix containing one probe template for each of the targets.
[0190] Optionally, the operator can also define an array of “anchor points.” The specimen may include an array of thousands of potential samples. In some instances, a large proportion of these will be populated, and in others relatively few will. In those instances in which relatively few sample points are populated, the specimen will include predefined “anchor” points to aid the system locating the probe template positions. In those instances in which a large proportion of the potential sample sites are populated, the samples themselves provide a sufficient population to position the probe templates, and anchor points may be unnecessary.
[0191] At block 216 , probe templates of the defined size with the defined grid spacing are generated and superimposed over the working specimen image. At this point, the operator can optionally provide a manual adjustment to the superimposed grid of probe templates, in order to bring them into general alignment with the actual specimens. He could do so, for example, by utilizing a mouse to shift the entire array then “grab specific probe templates and center them over the appropriate targets on the specimen. The operator might, for example, perform a general alignment by centering the probe templates in the four corners of the grid over the appropriate targets of the specimen. Although not essential, this manual adjustment will speed and simplify the processing done by computer 28 .
[0192] At block 218 , a process is performed, described in more detail below, in order to determine more precise locations for the probe templates relative to the actual location of potential targets. At the outset of this process, at block 218 , a determination is made whether the targets or anchor points have been adequately identified or defined. If targets have been well-defined, control is transferred to block 222 , where the array of probe templates is aligned to the defined targets; if not, but anchors have been well-defined, control is transferred to block 220 , where the array of probe templates is aligned to the anchors; otherwise, control is transferred to block 224 , where the predefined grid spacing and probe template for the array are utilized. It will be appreciated that, in some instances, it may be desirable to align the array on anchors and then on targets.
[0193] Once the probe templates and targets are aligned, the measurements within the individual probe templates are decoded to different conditions. For example, a probe may be capable of assuming any of n conditions, and the process of block 226 could decode the sample at each probe to one of those conditions. The actual process is performed on a statistical basis, and is best understood from a simple example relating to resolving a binary decision. However, those skilled in the art will appreciate that the process could actually be applied to resolving a multiple condition process. In the simplest case, the binary decision is a “yes” or “no” decision, which could be related to the presence or absence of a certain condition. In accordance with the process at block 226 , the actual levels at every probe of the specimen are measured, a mean and standard deviation are determined for the set of samples, and this results in a working statistical distribution. The decoding of a “yes” or “no” could then be done to any level of confidence selected by the operator. The operator's selection of a level of confidence results in the determination of a threshold level (e.g. based upon that level being located a calculated number of standard deviations from the mean on the distribution curve), and any signal above the threshold level would be considered a “yes”, while any signal below the threshold level would be considered a “no.”
[0194] At block 228 , a process is performed to generate a report of the array data, based upon the process performed at block 226 . It is contemplated that this may be any form of report writing software which provides the operator a substantial amount of flexibility in preparing reports of a desired format. Once the reports are generated, the process ends.
[0195] Attached as Appendix A is a more detailed discussion of the process of FIG. 9.
[0196] [0196]FIG. 10 is a flow chart illustrating the process performed in block 222 of FIG. 9.
[0197] After initiation of the process, image background and noise are estimated at block 300 . At block 302 , a determination is made whether a group alignment of the grid to the array of targets is necessary. This could be done either visually by an operator or by the system. The purpose of this test is to determine whether the grid is aligned to the targets overall. If done by the system, it would be performed by a conventional procedure for testing alignment of two regular patterns of shapes. If it is determined that adequate alignment of the group exists, control is transferred to block 306 .
[0198] At block 304 , a group alignment is performed. The purpose of this operation is to align the probe template grid roughly with the respective targets. The alignment may be done on the basis of the whole grid or part of the grid selected by the operator. This alignment could be done by the process discussed below with respect to block 306 for maximizing ID, except that ID is maximized over the entire grid.
[0199] At block 306 , a step-wise process is performed within the area of each individual probe template to locate that point which yields the maximum integrated density, ID, within the probe template, given by the formula (1):
ID ( x 0 , y 0)=∫ S(x0, y0) D ( x, y ) W ( x−x 0, y−y 0) dxdy (1)
[0200] where:
[0201] (x 0 ,y 0 ) is the center point of a probe template;
[0202] S(x 0 ,y 0 ) is the probe template area at (x 0 ,y 0 );
[0203] D(x,y) is the density value (e.g. brighteners) at (x,y); and
[0204] W(x,y) is a weighting function (e.g. a two-dimensional Gaussian function with its maximum value at (0,0)).
[0205] This yields an “A location” for each probe template, which is that location that provides the maximum value in formula (1). The probe template location prior to block 306 will be referred to as the “G location.”
[0206] At block 308 , a confidence weighting is performed between the A location and G location, in order to arrive at the final location of the center of each probe template. The confidence weighting factor for each A location is a form of signal-to-noise ratio. That is, the value of ID at each point is proportional to the ratio between the ID value at that point and the value determined at block 300 for that point. In effect the weighting factors are utilized to determine the position of the probe center along a straight line between the A and G locations, with weighting determining how close the point is to the A location.
[0207] Although the detailed description describes and illustrates preferred embodiments of the present apparatus, the invention is not so limited. Modifications and variations will now appear to persons skilled in this art. For a definition of the invention reference may be had to the appended claims.
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An electronic imaging system is disclosed, for assessing the intensity of calorimetric, fluorescent or luminescent signal in a matrix consisting of wells, microwells, hybridization dot blots on membranes, gels, or other specimens. The system includes a very sensitive area CCD detector, a fast, telecentric lens with epi-illumination, a reflective/transmissive illumination system, an illumination wavelength selection device, and a light-tight chamber. A computer and image analysis software are used to control the hardware, correct and calibrate the images, and detect and quantify targets within the images.
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FIELD OF THE INVENTION
The present invention relates to novel crystalline forms of an inhibitor of 11β-hydroxysteroid dehydrogenase Type 1. More particularly, the invention relates to novel crystalline anhydrates of 3-[4-(3-ethanesulfonyl-propyl)-bicyclo[2.2.2]oct-1-yl]-4-methyl-5-(2-trifluoromethyl-phenyl)-4H-1,2,4-triazole, which is a potent inhibitor of the 11β-hydroxysteroid dehydrogenase Type 1 (11β-HSD-1) enzyme. These novel crystalline forms of the 11β-HSD-1 inhibitor are useful for the preparation of pharmaceutical compositions containing the inhibitor for the treatment and prevention of diseases and conditions for which an inhibitor of 11β-HSD-1 is indicated, in particular Type 2 diabetes, hyperglycemia, obesity, dyslipidemia, hypertension, and cognitive impairment. The invention further concerns pharmaceutical compositions comprising the novel crystalline polymorphic forms of the present invention; processes for preparing the particular anhydrate forms and their pharmaceutical compositions; and methods of treating conditions for which an inhibitor of 11β-HSD-1 is indicated comprising administering a composition of the present invention.
BACKGROUND OF THE INVENTION
Inhibition of 11β-hydroxysteroid dehydrogenase Type 1 (11β-HSD-1), an enzyme that catalyzes regeneration of active 11-hydroxy glucocorticoids from inactive 11-keto metabolites within target tissues, represents a novel approach to the treatment of the conditions associated with the Metabolic Syndrome, including hypertension, obesity, dyslipidemia, and Type 2 diabetes, also known as non-insulin dependent diabetes mellitus (NIDDM). Inhibitors of this enzyme may also have utility to treat or prevent age-associated cognitive impairment. The therapeutic potential of inhibitors of 11β-HSD-1 has been reviewed: B. R. Walker and J. R. Seckl, “11β-Hydroxysteroid dehydrogenase Type 1 as a novel therapeutic target in metabolic and neurodegenerative disease,” Expert Opin. Ther. Targets, 7: 771-783 (2003).
U.S. Pat. No. 6,849,636 describes a class of substituted 1,2,4-triazoles, which are potent inhibitors of the 11β-HSD-1 enzyme and therefore useful for the treatment of Type 2 diabetes, hyperglycemia, obesity, dyslipidemia, hypertension, and cognitive impairment. Specifically disclosed in U.S. Pat. No. 6,849,636 is 3-[4-(3-ethanesulfonyl-propyl)-bicyclo[2.2.2]oct-1-yl]-4-methyl-5-(2-trifluoromethyl-phenyl)-4H-1,2,4-triazole.
However, there is no disclosure in U.S. Pat. No. 6,849,636 of the newly discovered crystalline anhydrate forms of 3-[4-(3-ethanesulfonyl-propyl)-bicyclo[2.2.2]oct-1-yl]-4-methyl-5-(2-trifluoromethyl-phenyl)-4H-1,2,4-triazole of structural formula I below (hereinafter referred to as Compound I).
The present invention also discloses novel crystalline methanol and ethanol solvates of Compound I.
SUMMARY OF THE INVENTION
The present invention is concerned with novel crystalline anhydrates of the 11β-hydroxysteroid dehydrogenase Type 1 (11β-HSD-1) inhibitor 3-[4-(3-ethanesulfonyl-propyl)-bicyclo[2.2.2]oct-1-yl]-4-methyl-5-(2-trifluoromethyl-phenyl)-4H-1,2,4-triazole of structural formula I (Compound I). The crystalline anhydrate forms of the present invention have advantages over the previously disclosed amorphous form of 3-[4-(3-ethanesulfonyl-propyl)-bicyclo[2.2.2]oct-1-yl]-4-methyl-5-(2-trifluoromethyl-phenyl)-4H-1,2,4-triazole in the preparation of pharmaceutical compositions, such as ease of processing, handling, and dosing. In particular, they exhibit improved physicochemical properties, such as stability to stress, rendering them particularly suitable for the manufacture of various pharmaceutical dosage forms. The invention also concerns pharmaceutical compositions containing the novel crystalline polymorphs; processes for the preparation of these polymorphic forms and their pharmaceutical compositions; and methods for using them for the prevention or treatment of Type 2 diabetes, hyperglycemia, obesity, dyslipidemia, hypertension, and cognitive impairment.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a characteristic X-ray diffraction pattern of a crystalline anhydrate, designated Form I, of Compound I of the present invention.
FIG. 2 is a carbon-13 cross-polarization magic-angle spinning (CPMAS) nuclear magnetic resonance (NMR) spectrum of a crystalline anhydrate, designated Form I, of Compound I of the present invention.
FIG. 3 is a typical differential scanning calorimetry (DSC) curve of a crystalline anhydrate, designated Form I, of Compound I of the present invention.
FIG. 4 is a characteristic X-ray diffraction pattern of a crystalline anhydrate, designated Form II, of Compound I of the present invention.
FIG. 5 is a carbon-13 cross-polarization magic-angle spinning (CPMAS) nuclear magnetic resonance (NMR) spectrum of a crystalline anhydrate, designated Form II, of Compound I of the present invention.
FIG. 6 is a characteristic X-ray diffraction pattern of a crystalline anhydrate, designated Form III, of Compound I of the present invention.
FIG. 7 is a carbon-13 cross-polarization magic-angle spinning (CPMAS) nuclear magnetic resonance (NMR) spectrum of a crystalline anhydrate, designated Form III, of Compound I of the present invention.
FIG. 8 is a typical differential scanning calorimetry (DSC) curve of a crystalline anhydrate, designated Form III, of Compound I of the present invention.
FIG. 9 is a characteristic X-ray diffraction pattern of the crystalline methanol solvate of Compound I of the present invention.
FIG. 10 is a typical thermogravimetric analysis (TGA) curve of the crystalline methanol solvate of Compound I of the present invention.
FIG. 11 is a characteristic X-ray diffraction pattern of the crystalline ethanol solvate of Compound I of the present invention.
FIG. 12 is a typical differential scanning calorimetry (DSC) curve of the crystalline ethanol solvate of Compound I of the present invention.
FIG. 13 is a typical thermogravimetric analysis (TGA) curve of the crystalline ethanol solvate of Compound I of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
This invention provides novel crystalline anhydrate polymorphic forms of 3-[4-(3-ethanesulfonyl-propyl)-bicyclo[2.2.2]oct-1-yl]-4-methyl-5-(2-trifluoromethyl-phenyl)-4H-1,2,4-triazole of structural formula I (Compound I):
A further embodiment of the present invention provides the Compound I drug substance that comprises a crystalline anhydrate form in a detectable amount. By “drug substance” is meant the active pharmaceutical ingredient (API). The amount of crystalline anhydrate form in the drug substance can be quantified by the use of physical methods such as X-ray powder diffraction (XRPD), solid-state fluorine-19 magic-angle spinning (MAS) nuclear magnetic resonance spectroscopy, solid-state carbon-13 cross-polarization magic-angle spinning (CPMAS) nuclear magnetic resonance spectroscopy, solid state Fourier-transform infrared spectroscopy, and Raman spectroscopy. In a class of this embodiment, about 5% to about 100% by weight of the crystalline anhydrate form is present in the drug substance. In a second class of this embodiment, about 10% to about 100% by weight of the crystalline anhydrate form is present in the drug substance. In a third class of this embodiment, about 25% to about 100% by weight of the crystalline anhydrate form is present in the drug substance. In a fourth class of this embodiment, about 50% to about 100% by weight of the crystalline anhydrate form is present in the drug substance. In a fifth class of this embodiment, about 75% to about 100% by weight of the crystalline anhydrate form is present in the drug substance. In a sixth class of this embodiment, substantially all of the Compound I drug substance is the crystalline anhydrate form, i.e., the Compound I drug substance is substantially phase pure crystalline anhydrate form.
Another aspect of the present invention provides a novel crystalline methanol solvate of Compound I.
Yet another aspect of the present invention provides a novel crystalline ethanol solvate of Compound I.
These crystalline solvates have utility as intermediates in the preparation of the crystalline anhydrates of the present invention.
The present invention further provides a method for the prevention or treatment of clinical conditions for which an inhibitor of 11β-HSD-1 is indicated, which method comprises administering to a patient in need of such prevention or treatment a prophylactically or therapeutically effective amount of a crystalline anhydrate of Compound I or a pharmaceutical composition containing a prophylactically or therapeutically effective amount of a crystalline anhydrate form of Compound I. Such clinical conditions include Type 2 diabetes, hyperglycemia, obesity, dyslipidemia, hypertension, and cognitive impairment.
The present invention also provides for the use of a crystalline anhydrate form of the present invention in the manufacture of a medicament for the prevention or treatment in a mammal of clinical conditions for which an inhibitor of 11β-HSD-1 is indicated.
Another aspect of the present invention provides a crystalline anhydrate form for use in the prevention or treatment in a mammal of clinical conditions for which an inhibitor of 11β-HSD-1 is indicated.
The present invention also provides pharmaceutical compositions comprising a crystalline anhydrate form, in association with one or more pharmaceutically acceptable carriers or excipients. In one embodiment the pharmaceutical composition comprises a prophylactically or therapeutically effective amount of the active pharmaceutical ingredient (API) in admixture with pharmaceutically acceptable excipients wherein the API comprises a detectable amount of a crystalline anhydrate form of the present invention. In a second embodiment the pharmaceutical composition comprises a prophylactically or therapeutically effective amount of the API in admixture with pharmaceutically acceptable excipients wherein the API comprises about 5% to about 100% by weight of a crystalline anhydrate form of the present invention. In a class of this second embodiment, the API in such compositions comprises about 10% to about 100% by weight of such a crystalline anhydrate form. In a second class of this embodiment, the API in such compositions comprises about 25% to about 100% by weight of such a crystalline anhydrate form. In a third class of this embodiment, the API in such compositions comprises about 50% to about 100% by weight of such a crystalline anhydrate form. In a fourth class of this embodiment, the API in such compositions comprises about 75% to about 100% by weight of such a crystalline anhydrate form. In a fifth class of this embodiment, substantially all of the API is in a crystalline anhydrate form of Compound I, i.e., the API is substantially phase pure Compound crystalline anhydrate form.
The compositions in accordance with the invention are suitably in unit dosage forms such as tablets, pills, capsules, powders, granules, sterile solutions or suspensions, metered aerosol or liquid sprays, drops, ampoules, auto-injector devices or suppositories. The compositions are intended for oral, parenteral, intranasal, sublingual, or rectal administration, or for administration by inhalation or insufflation. Formulation of the compositions according to the invention can conveniently be effected by methods known from the art, for example, as described in Remington's Pharmaceutical Sciences, 17 th ed., 1995.
The dosage regimen is selected in accordance with a variety of factors including type, species, age, weight, sex and medical condition of the patient; the severity of the condition to be treated; the route of administration; and the renal and hepatic function of the patient. An ordinarily skilled physician, veterinarian, or clinician can readily determine and prescribe the effective amount of the drug required to prevent, counter or arrest the progress of the condition.
Oral dosages of the present invention, when used for the indicated effects, will range between about 0.01 mg per kg of body weight per day (mg/kg/day) to about 100 mg/kg/day, preferably 0.01 to 10 mg/kg/day, and most preferably 0.1 to 5.0 mg/kg/day. For oral administration, the compositions are preferably provided in the form of tablets containing 0.01, 0.05, 0.1, 0.5, 1.0, 2.5, 5.0, 10.0, 15.0, 25.0, 50.0, 100, 200, and 500 milligrams of the API for the symptomatic adjustment of the dosage to the patient to be treated. A medicament typically contains from about 0.5 mg to about 500 mg of the API, preferably, from about 1 mg to about 200 mg of API. Intravenously, the most preferred doses will range from about 0.1 to about 10 mg/kg/minute during a constant rate infusion. Advantageously, the crystalline anhydrate and monohydrate forms of the present invention may be administered in a single daily dose, or the total daily dosage may be administered in divided doses of two, three or four times daily. Furthermore, the crystalline anhydrate forms of the present invention can be administered in intranasal form via topical use of suitable intranasal vehicles, or via transdermal routes, using those forms of transdermal skin patches well known to those of ordinary skill in the art. To be administered in the form of a transdermal delivery system, the dosage administration will, of course, be continuous rather than intermittent throughout the dosage regimen.
In the methods of the present invention, the Compound I crystalline anhydrate forms described herein can form the API, and are typically administered in admixture with suitable pharmaceutical diluents, excipients or carriers (collectively referred to herein as ‘carrier’ materials) suitably selected with respect to the intended form of administration, that is, oral tablets, capsules, elixirs, syrups and the like, and consistent with conventional pharmaceutical practices.
For instance, for oral administration in the form of a tablet or capsule, the active pharmaceutical ingredient can be combined with an oral, non-toxic, pharmaceutically acceptable, inert carrier such as lactose, starch, sucrose, glucose, methyl cellulose, magnesium stearate, dicalcium phosphate, calcium sulfate, mannitol, sorbitol and the like; for oral administration in liquid form, the oral API can be combined with any oral, non-toxic, pharmaceutically acceptable inert carrier such as ethanol, glycerol, water and the like. Moreover, when desired or necessary, suitable binders, lubricants, disintegrating agents and coloring agents can also be incorporated into the mixture. Suitable binders include starch, gelatin, natural sugars such as glucose or beta-lactose, corn sweeteners, natural and synthetic gums such as acacia, tragacanth or sodium alginate, carboxymethylcellulose, polyethylene glycol, waxes and the like. Lubricants used in these dosage forms include sodium oleate, sodium stearate, magnesium stearate, sodium benzoate, sodium acetate, sodium chloride and the like. Disintegrators include, without limitation, starch, methyl cellulose, agar, bentonite, xanthan gum and the like.
The following non-limiting Examples are intended to illustrate the present invention and should not be construed as being limitations on the scope or spirit of the instant invention.
General Conditions for Preferentially Crystallizing Anhydrate Form
The anhydrate form can be crystallized from numerous organic solvents and solvent mixtures. These include methyl acetate, ethyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, toluene, acetone, 2-butanone, tetrahydrofuran, methyl t-butyl ether, and mixtures with pentane, hexanes, heptane, octane, and isooctane. Crystallization can be induced by cooling, evaporation, or addition of a non-polar solvent, such as hexanes or heptane.
General Conditions for Preparing the Crystalline Methanol Solvate
The crystalline methanol solvate can be prepared by stirring a mixture of the anhydrate in methanol for a time sufficient for phase equilibration. The methanol solvate was characterized by physical methods as described below. The methanol solvate can be re-converted into the crystalline anhydrate by drying under vacuum at 40° C. for 3 days.
General Conditions for Preparing the Crystalline Ethanol Solvate
The crystalline ethanol solvate can be prepared by stirring a mixture of the anhydrate in ethanol for a time sufficient for phase equilibration. The ethanol solvate was characterized by physical methods as described below. The ethanol solvate can be re-converted into the crystalline anhydrate by drying under vacuum at 40° C. for 3 days.
SYNTHESIS
Compound I may be prepared using the reactions and techniques described in U.S. Pat. No. 6,849,636.
The following examples further illustrate the crystalline anhydrate forms of Compound I, viz., those polymorphic forms referred to as Form I, Form II and Form III.
Example 1
3-[4-(3-ethanesulfonyl-propyl)-bicyclo[2.2.2]oct-1-yl]-4-methyl-5-(2-trifluoromethyl-phenyl)-4H-1,2,4-triazole crystalline anhydrate (Form II)
Compound I (3-[4-(3-ethanesulfonyl-propyl)-bicyclo[2.2.2]oct-1-yl]-4-methyl-5-(2-trifluoromethyl-phenyl)-4H-1,2,4-triazole) was freebased in two equal portions via treatment of an isopropylacetamide (iPAc) slurry of Compound I with excess aqueous NaOH. Following a filtration step, the two solution portions were then combined and crystallized from iPAc as the Form II crystalline anhydrate.
Example 2
3-[4-(3-ethanesulfonyl-propyl)-bicyclo[2.2.2]oct-1-yl]-4-methyl-5-(2-trifluoromethyl-phenyl)-4H-1,2,4-triazole crystalline anhydrate (Form I)
The Form II crystalline anhydrate was converted to the Form I anhydrate by adjusting the solvent composition to 10% methanol in iPAc, dissolving the material below reflux and seeding at 50° C. After aging overnight at 40° C., the slurry was evaluated and found to be Form I anhydrate exclusively.
Example 3
3-[4-(3-ethanesulfonyl-propyl)-bicyclo[2.2.2]oct-1-yl]-4-methyl-5-(2-trifluoromethyl-phenyl)-4H-1,2,4-triazole crystalline anhydrate (Form III)
It was discovered that if the aging step described above (overnight at 40° C.) is skipped, and the material is allowed to cool to room temperature, the resultant mixture is found to be Forms I and III of the crystalline anhydrate. Using the Form III (as little as 0.5 weight %) to seed a room temperature iPAc slurry (or a 10% methanol/iPAc slurry) of Form I anhydrate results in complete turnover, following a 14-16 hour aging period to the more thermodynamically stable Form III.
Form III can also be directly crystallized from the free base in an iPAc or methanol/iPAc solution upon seeding at 30-35° C. (or at room temperature) with Form III material.
X-ray powder diffraction studies are widely used to characterize molecular structures, crystallinity, and polymorphism. The X-ray powder diffraction patterns of the crystalline polymorphs of the present invention were generated on a Philips Analytical X'Pert PRO X-ray Diffraction System with PW3040/60 console. A PW3373/00 ceramic Cu LEF X-ray tube K-Alpha radiation was used as the source.
FIG. 1 shows a characteristic X-ray diffraction pattern for the crystalline anhydrate form (Form I) of Compound I of the present invention. The anhydrate form exhibited characteristic reflections corresponding to d-spacings of 6.56, 6.33, 6.19, 5.63, 5.27, 4.93, 4.74, 4.65, 4.51, and 4.37 angstroms.
FIG. 4 shows an X-ray diffraction pattern for the crystalline anhydrate form (Form II) of Compound I of the present invention. This anhydrate form exhibited characteristic reflections corresponding to d-spacings of 18.33, 9.37, 8.62, 6.28, 6.02, 5.97, 5.30, 5.14, 5.01, and 4.86 angstroms.
FIG. 6 shows an X-ray diffraction pattern for the crystalline anhydrate (Form III) of the present invention. This anhydrate exhibited characteristic reflections corresponding to d-spacings of 9.26, 5.90, 5.78, 5.33, 5.16, 5.10, 5.03, 4.69, 4.61, and 4.26 angstroms.
FIG. 9 shows a characteristic X-ray diffraction pattern for the crystalline methanol solvate of Compound I of the present invention. The methanol solvate exhibited characteristic reflections corresponding to d-spacings of 9.88, 6.13, 5.36, 4.65, 4.43, 4.39, 4.08, 3.98, 3.36 and 3.26 angstroms.
FIG. 11 is a characteristic X-ray diffraction pattern for the crystalline ethanol solvate of Compound I of the present invention. The ethanol solvate exhibited characteristic reflections corresponding to d-spacings 10.03, 6.66, 6.29, 5.38, 4.74, 4.46, 4.41, 4.15, 4.04 and 3.30 angstroms.
In addition to the X-ray powder diffraction patterns described above, the crystalline polymorphic forms of Compound I of the present invention were further characterized by their solid-state carbon-13 nuclear magnetic resonance (NMR) spectra. The solid-state carbon-13 NMR spectrum was obtained on a Bruker DSX 400WB NMR system using a Bruker 4 mm double resonance CPMAS probe. The carbon-13 NMR spectrum utilized proton/carbon-13 cross-polarization magic-angle spinning with variable-amplitude cross polarization. The sample was spun at 15.0 kHz, and a total of 1024 scans were collected with a recycle delay of 5 seconds. A line broadening of 40 Hz was applied to the spectrum before FT was performed. Chemical shifts are reported on the TMS scale using the carbonyl carbon of glycine (176.03 p.p.m.) as a secondary reference.
FIG. 2 shows the solid state carbon-13 CPMAS NMR spectrum for the crystalline anhydrate form (Form I) of Compound I. This crystalline anhydrate form exhibited characteristic signals with chemical shift values of 160.2, 153.6, 133.4, 129.8, 127.6, 48.0, 33.4, 32.7, 29.6, and 6.9 p.p.m.
FIG. 5 shows the solid state carbon-13 CPMAS NMR spectrum for the crystalline anhydrate form (Form II) of Compound I. This crystalline anhydrate form exhibited characteristic signals with chemical shift values of 153.2, 131.6, 129.0, 125.4, 54.4, 45.8, 32.3, 30.6, 29.4, and 4.8 p.p.m.
FIG. 7 shows the solid state carbon-13 CPMAS NMR spectrum for the crystalline anhydrate form (Form III) of Compound I. This crystalline anhydrate form exhibited characteristic signals with chemical shift values of 160.1, 153.9, 134.0, 131.4, 129.5, 127.0, 54.8, 51.5, 33.4, and 5.9 p.p.m.
Additionally, differential scanning calorimetry (DSC) was performed. DSC data were acquired using TA Instruments DSC 2910 (or equivalent instrumentation). Between 2 and 6 mg sample was weighed into an open pan. This pan was then crimped and placed at the sample position in the calorimeter cell. An empty pan was placed at the reference position. The calorimeter cell was closed and a flow of nitrogen was passed through the cell. The heating program was set to heat the sample at a heating rate of 10° C./min to a temperature of approximately 250° C. The heating program was started. When the run was completed, the data were analyzed using the DSC analysis program contained in the system software. The melting endotherm was integrated between baseline temperature points that are above and below the temperature range over which the endotherm was observed. The data reported are the onset temperature, peak temperature and enthalpy.
FIG. 3 shows the differential calorimetry scan for the crystalline anhydrate form (Form I) of Compound I. This crystalline anhydrate form exhibited a melting endotherm with an onset temperature of 174.1° C., a peak temperature of 177.7° C., and an enthalpy of 68.5 J/g.
FIG. 8 shows the differential calorimetry scan for the crystalline anhydrate form (Form III) of Compound I. This crystalline anhydrate form exhibited a first endotherm with an onset temperature of 177.5° C., a peak temperature of 179.7° C., and an enthalpy of 37.3 J/g. The first thermal event was followed by a second endotherm, with an onset temperature of 189.6° C. and a peak temperature of 191.4° C. and an enthalpy of 35.8 J/g.
A Perkin Elmer model TGA 7 (or equivalent instrument) was used to obtain the thermogravimetric analysis (TGA) curves. Experiments were performed under a flow of nitrogen and using a heating rate of 10° C./min to a maximum temperature of approximately 250° C. After automatically taring the balance, 5 to 20 mg of sample was added to the platinum pan, the furnace was raised, and the heating program started. Weight/temperature data were collected automatically by the instrument. Analysis of the results was carried, out by selecting the Delta Y function within the instrument software and choosing the temperatures between which the weight loss was to be calculated. Weight losses are reported up to the onset of decomposition/evaporation.
FIG. 10 shows a characteristic thermogravimetric analysis (TGA) curve for the crystalline methanol solvate form of Compound I. TGA indicated a weight loss of about 5.8% at 120° C.
FIG. 13 shows a characteristic thermogravimetric analysis (TGA) curve for the crystalline ethanol solvate of Compound I. TGA indicated a weight loss of about 7.8% at 120° C.
Example of a Pharmaceutical Composition:
A crystalline anhydrate form of the present invention was formulated into a capsule formulation as follows. A 100 mg potency capsule was composed of 100 mg of the API, 190 mg of microcrystalline cellulose, and about 95 mg gelatin as in #0 white opaque gelatin capsule. The API and microcrystalline cellulose were first blended, and the mixture was then encapsulated in gelatin capsules.
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Novel crystalline salts of 3-[4-(3-ethanesulfonyl-propyl)-bicyclo[2.2.2]oct-1-yl]-4-methyl-5-(2-trifluoromethyl-phenyl)-4H-1,2,4-triazole are potent inhibitors of 11β-hydroxysteroid dehydrogenase Type 1 and are useful for the treatment of conditions associated with Metabolic Syndrome as well as cognitive impairment. The invention also relates to pharmaceutical compositions containing these novel salts, processes to prepare these salts and their pharmaceutical compositions as well as uses thereof for the treatment of Type 2 diabetes, hyperglycemia, obesity, dyslipidemia, hypertension, and cognitive impairment.
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This is a continuation of application Ser. No. 07/423,309 filed Oct. 18, 1989, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to multilayered structures having polycarbonate and polyamide layers; and, more particularly, relates to multilayered structures having a functionalized polyamide layer and a polycarbonate resin layer.
2. Description of Related Art
Multilayered structures having a polycarbonate layer and a polyamide layer have been employed in the past (see for example Collins, U.S. Pat. No. 4,513,037) wherein is disclosed a multilayered structure having a polycarbonate outer layer, a polycarbonate inner layer, and a polyamide intermediate layer between the two polycarbonate layers. The polycarbonate layers provide the structure with good impact strength, but typically lack desired levels of oxygen barrier properties. The polyamide layer, in particular amorphous polyamides, provides the structure with the desired levels of oxygen barrier properties, but typically lacks adequate impact strength. The multiple layer structure of Collins combines the desired properties of the polycarbonate layer and the polyamide layer to obtain a structure having both adequate impact strength and adequate oxygen barrier properties.
Multiple layered structures of a polycarbonate layer and a polyamide layer generally lack desired levels of adhesion and require the use of tie layers if adhesion is to be obtained between the layers. Tie layers however can add additional processing requirements in the creation of the structure. Multiple layered structures consisting of polycarbonate layers and polyamide layers in direct contact with each other which do not employ a tie layer have generally resulted in laminates which delaminate under stress. Thus, it is an object of the present invention to provide a multilayered structure having good direct adhesion between the polyamide layer and the polycarbonate layer comprising layers of a polycarbonate resin layer and an amine functionalized polyamide resin in direct adhering contact with each other.
SUMMARY OF THE INVENTION
The present invention relates to multilayered structures comprising a polycarbonate layer and an amine functionalized polyamide layer. The multilayered structures exhibit good direct contact adhesion between the layers of a polycarbonate resin and a polyamide resin in direct contact with each other and bonded to each other without the use of a tie layer between the polycarbonate layer and the polyamide layer. Exemplary multilayered structures include laminates and shaped articles, such as bottles.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to multilayered structures comprising a polycarbonate layer in direct contact with a polyamide layer and bonded thereto without the use of a tie layer therebetween. The multilayered structures of the present invention comprise a layer of a functionalized polyamide which is derived from a dicarboxylic acid, a diamine and a polyamine.
Polycarbonates for use in the structures of the present invention are high molecular weight, thermoplastic, aromatic polymers and include homopolycarbonates, copolycarbonates and copolyestercarbonates and mixtures thereof which have average molecular weights of about 8,000 to more than 200,000, preferably of about 20,000 to 80,000 and an I.V. of 0.40 to 1.0 dl/g as measured in methylene chloride at 25° C. In one embodiment, the polycarbonates are derived from dihydric phenols and carbonate precursors and generally contain recurring structural units of the formula: ##STR1## where Y is a divalent aromatic radical of the dihydric phenol employed in the polycarbonate producing reaction.
Suitable dihydric phenols for producing polycarbonates include the dihydric phenols such as, for example, 2,2-bis(4-hydroxyphenyl)propane, bis(4-hydroxyphenyl )methane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 4,4-bis(4-hydroxyphenyl)heptane, 2,2-(3,5,3',5'-tetrachloro-4,4'-dihydroxyphenyl)propane, 2,2-(3,5,3',5'-tetrabromo-4,4'-)propane, and 3,3'-di-chloro-4,4-dihydroxydiphenyl)methane. Other dihydric phenols which are also suitable for use in the preparation of the above polycarbonates are disclosed in U.S. Pat. Nos. 2,999,835, 3,038,365, 3,334,154, and 4,131,575, incorporated herein by reference.
It is of course possible to employ two or more different dihydric phenols or a copolymer of a dihydric phenol with a glycol or with a hydroxy- or acid- terminated polyester, or with a dibasic acid in the event a carbonate copolymer or interpolymer rather than a homopolymer is desired for use in the preparation of the articles of the invention. Blends of any of the above materials can also be employed to provide the aromatic polycarbonate. In addition, branched polycarbonates such as are described in U.S. Pat. No. 4,001,184, can also be utilized in the practice of this invention, as can blends of a linear polycarbonate and a branched polycarbonate.
The carbonate precursor employed can be either a carbonyl halide, a carbonate ester or a haloformate. The carbonyl halides which can be employed are carbonyl bromide, carbonyl chloride and mixtures thereof. Typical of the carbonate esters which can be employed are diphenyl carbonate, a di(halophenyl)carbonate such as di(chlorophenyl)carbonate, di(bromophenyl)carbonate, di(trichlorophenyl)carbonate, di(tribromophenyl)carbonate, etc., di(alkylphenyl)carbonate such as di(tolyl)carbonate, etc., di(naphthyl)carbonate, di(chloronaphthyl)carbonate, etc., or mixtures thereof. The suitable haloformates include bis-haloformates of dihydric phenols (bischloroformates of hydroquinone, etc.) or glycols (bishaloformates of ethylene glycol, neopentyl glycol, polyethylene glycol, etc.). While other carbonate precursors will occur to those skilled in the art, carbonyl chloride, also known as phosgene, is preferred.
The polycarbonate may also be a copolyestercarbonate as described in Clayton B. Quinn in U.S. Pat. No. 4,430,484 and the references cited therein, incorporated herein by reference. Preferred polyestercarbonates are those derived from the dihydric phenols and carbonate precursors described above and aromatic dicarboxylic acids or their relative derivatives, such as the acid dihalides, e.g., dichlorides. A quite useful class of aromatic polyestercarbonates are those derived from bisphenol A; terephthalic acid, isophthalic acid or a mixture thereof or their respective acid chlorides; and phosgene. If a mixture of terephthalic acid and isophthalic acid is employed, the weight ratio of terephthalic acid to isophthalic acid may be from about 5:95 to about 95:5. Another polycarbonate which may be used has from about 70 to about 95 weight percent ester content and a range of terephthalate groups of from 2 to about 15 weight percent of the total ester content. The remaining ester units are isophthalate units. These polycarbonates are more commonly known as polyphthalate carbonates and are described, for example, by Miller, et. al., U.S. Pat. No. 4,465,820, herein incorporated by reference in its entirety.
The polycarbonates used to form the present invention can be manufactured by known processes, such as, for example, by reacting a dihydric phenol with a carbonate precursor such as diphenyl carbonate or phosgene in accordance with the methods set forth in the above-cited literature and U.S. Pat. Nos. 4,018,750 and 4,123,436, or by transesterification processes such as are disclosed in U.S. Pat. No. 3,153,008 as well as other processes known to those skilled in the art.
The aromatic polycarbonates are typically prepared by employing a molecular weight regulator, an acid acceptor and a catalyst. The molecular weight regulators which can be employed include phenol, cyclohexanol, methanol, alkylated phenols, such as octrylphenol, paratertiary-butyl-phenol, etc. Preferably, phenol or an alkylated phenol is employed as the molecular weight regulator.
The acid acceptor can be either an organic or an inorganic acid acceptor. A suitable organic acid acceptor is a tertiary amine and includes such materials as pyridine, triethyl amine, dimethylaniline, tributylamine, etc. The inorganic acid acceptor can be one which can be either a hydroxide, a carbonate, a bicarbonate, or a phosphate or an alkali or alkaline earth metal.
The catalyst which can be employed are those that typically aid the polymerization of the monomer with phosgene. Suitable catalysts include tertiary amines such as tri ethyl amine, tripropyl amine, N,N-dimethylaniline, quaternary ammonium bromide, cetyl triethyl ammonium bromide, tetra-n-heptyl ammonium iodide, tetra-n-propyl ammonium bromide, tetramethyl ammonium chloride, tetra-methyl ammonium hydroxide, tetra-n-butyl ammonium iodide, benzyltrimethyl ammonium chloride and quaternary phosphonium compounds such as, for example, n-butyltriphenyl phosphonium bromide and methyltriphenyl phosphonium bromide.
Also included are branched polycarbonates wherein a polyfunctional aromatic compound is reacted with the monomer and carbonate precursor to provide a thermoplastic randomly branched polycarbonate. The polyfunctional aromatic compounds contain at least three functional groups which are carboxyl, carboxylic anhydride, haloformyl, or mixtures thereof. Illustrative polyfunctional aromatic compounds which can be employed include trimellitic anhydride, trimellitic acid, trimellityl trichloride, 4-chloroformyl phthalic anhydride, pyromellitic acid, pyromellitic dianhydride, mellitic acid, mellitic anhydride, benzophenone-tetracarboxylic anhydride, and the like. The preferred polyfunctional aromatic compounds are trimellitic anhydride and trimellitic acid or their acid halide derivatives.
Polyamides for use in the production of the multilayered structures of the present invention are produced from the reaction products of a diamine and a carboxylic acid or a reactive diester thereof wherein the polyamide is chemically modified by substituting a polyfunctional monomer for a portion of the diamine in the synthesis step. Preferably, the polyamides have an amine number of at least 105 meq/kg to facilitate adhesion between the layers.
Suitable diamines for use in the production of the polyamides are of the general formula:
H.sub.2 N -- R.sub.1 -- NH.sub.2
wherein R 1 is an aliphatic, aromatic, unsaturated, or branched hydrocarbon having from 1 to 20 carbon atoms, and mixtures thereof. Examples of suitable diamines include ethylene diamine, decamethylene diamine, dodecamethylene diamine, 2,2,4- or 2,4,4-trimethyl enehexamethylene diamine, p- or m-xylylene diamine, bis-(4-amino cyclohexyl)methane, 3-amino methyl-3,5,5-trimethyl cyclohexyl amine or 1,4-diaminomethyl cyclohexane.
A particularly preferred diamine for use in the present invention is hexamethylenediamine of the formula:
H.sub.2 N -- (CH.sub.2).sub.6 -- NH.sub.2.
Suitable dicarboxylic acids for use in the present invention are of the general formula: ##STR2## wherein R 2 is an aliphatic, aromatic, unsaturated, or mixtures of hydrocarbons having from 1 to 20 carbon atoms. Examples of suitable dicarboxylic acids include sebacic acid, heptadecaniodicarboxylic acid, adipic acid, 2,2,4-or 2,4,4-trimethyl adipic acid, and terephthalic acid. Blends of dicarboxylic acids may also be employed.
A particularly preferred dicarboxylic acid for use in the present invention is isophthalic acid which has the formula: ##STR3## Also preferred are blends of isophthalic acid and terephthalic acid, for example, 65 mole % isophthalic acid and 35% terephthalic acid.
The term dicarboxylic acid is meant to include reactive diesters of a dicarboxylic acid such as those represented by the formula: ##STR4## wherein R 3 , R 4 and R 5 are the same or different aliphatic, aromatic or unsaturated hydrocarbons having from 1 to 20 hydrocarbons.
A particularly suitable diester of a dicarboxylic acid is diphenylisophthalate of the formula: ##STR5## Also preferred are blends of diesters of dicarboxylic acids such as blends of isophthalic acid and terephthalic acid.
If a diaryl ester of a dicarboxylic acid is employed, then phenol may be produced as a byproduct in the production of the polyamide. Excess phenol should be removed from the polyamide because the presence of phenol will inhibit adhesion between the polyamide and polycarbonate layers.
Suitable multifunctional monomers for use in the present invention are polyamines of the general formula: ##STR6## wherein R 6 and R 7 are the same or different aliphatic, aromatic, or unsaturated hydrocarbons, n is an integer from 1 to 6, and m is an integer from 1 to6.
It is important that the internal amine is less reactive than the amine end groups to prevent unduly large viscosity increases that can result from undesired crosslinking during formation of the functionalized polyamide. It is also important that at least a slight excess of amine (for example 1% based on total moles of acid) be employed in the reaction so that the internal amine does not become capped by reacting with excess dicarboxylic acid.
Particularly suitable multifunctional monomers for use in the present invention include diethylenetriamine of the formula: ##STR7## 3,3'-iminobispropyl amine of the formula: ##STR8## and bishexamethylene triamine of the formula: ##STR9##
The multifunctional monomer is preferably present at a level of from about 3 percent to about 99 percent by mole based on the combined total moles of multifunctional monomer and moles of diamine and more preferably from about 5 percent to about 20 mole percent thereof, and most preferably about 10 percent thereof. It was found that adhesion of the polyamide to the polycarbonate was only successful when excess amine groups were present i n the reaction mixture so that the internal functional amine groups are not capped by excess acid groups. High ratio amine can be achieved by either the addition of an amine chain stopper or by employing the multifunctional monomer in excess of the dicarboxylic acid or the diester of the dicarboxylic acid. An example of a suitable chain stopper is docadecylamine.
The preferred embodiment of the present invention comprises reacting diphenyl isophthalate, hexamethylenediamine and diethylenetriamine according to the generalized reaction scheme: ##STR10## Preferably the diethylenetriamine is present at about 10% mole based on the total moles of hexamethylenediamine and diethylenetriamine. It has been found that when the dicarboxylic acid is a diester derivative, the phenol should be removed from the polyamide before the polyamide and the polycarbonate are adhered to each other. Suitable polyamides may be obtained from reaction mixtures of hexamethylenediamine, a polyamine, isophthalic acid and terephthalic acid.
The polyamides and polycarbonates can be adhered to each other by suitable methods, such as coextrusion or by pressing the films or sheets together under high pressure and heat. The polyamide and polycarbonate layers should each be at least a half mil thick. The resulting multilayered structures can be used to form laminates and shaped articles, such as bottles.
Although the desired thickness of each layer will depend on the desired properties of the particular structure, a suitable bottle structure could have the polyamide layer preferably being a thickness of from 1 mil to 60 mils, more preferably from 2 mils to 30 mils and most preferably about 10 mils, and the polycarbonate layer preferably being a thickness of from 1 mil to 60 mils, more preferably from 2 mils to 30 mils and most preferably about 10 mils.
The term multilayered is meant to include structures having two or more layers.
The following examples are set forth to illustrate the present invention and are not to be construed as limiting the scope of the invention thereto.
EXAMPLES
The following examples illustrate the present invention but are not meant to limit the scope thereof.
TABLE 1______________________________________Adhesion to ThermoplasticsExamples % DETA.sup.a iv (dl/g).sup.b Tg (°C.).sup.c Laminated Adhesion______________________________________1 0 0.967 123 No2 1 1.052 128 No3 3 1.182 128 Some4 5 1.182 123 Yes 5 1.264 128 Yes5 10 1.087 131 Yes 10 0.971 130 Yes______________________________________ .sup.a % DETA is mole percent of diethylene triamine based on total moles of diethylenetriamine and hexamethylenediamine (HMDA). Example 1 was nylo 6,I. Examples 2 to 5 were DETA modified nylon 6,I obtained by reacting DETA and HMDA with diphenyl isophthalate (DPI). .sup.b iv (dl/g) were determined for the polyamide in 60/40 phenol/tetrachloroethane at 25° C. .sup.c Tg is the glass transition temperature in °C. for the polyamide. .sup.d The laminate was obtained by pressing together a film of polycarbonate made from the reaction products of bisphenol A and phosgene and a film of the polyamide at a temperature of 550° F.
TABLE 2__________________________________________________________________________Summary of Film Adhesion StudyNo. Polyamide Polyamide Film Quality Adhesion to Polycarbonate__________________________________________________________________________ 6 50% DETA/50% HMDA Brittle Yes, But Very Brittle 100% DPI.sup.e 7 100% DETA/100% DPI Very brittle Yes, But Very Brittle Excess Amine 8 10% DETA/90% HMDA/100% DPI Flexible Yes, Flexible Excess Amine 9 1% DETA/99% HMDA/100% DPI Flexible No Excess Amine10 5% DETA/95% HMDA/100% DPI Flexible Yes, Flexible Excess Amine11 1% DETA/99% HMDA/100% DPI Flexible No Excess DPI12 5% DETA/95% HMDA/100% DPI Flexible No No Excess13 10% DETA/90% HMDA/100% DPI Flexible No No Excess14 10% DETA/90% HMDA/100% DPI Flexible No Excess DPI15 1% DETA/99% HMDA/100% DPI Flexible No No Excess16 1% DETA/99% HMDA/100% DPI Flexible No Excess DPI17 5% DETA/95% HMDA/100% DPI Flexible Yes Excess Amine18 3% DETA/97% HMDA/100% DPI Flexible Some Excess Amine19 5% DETA/95% HMDA/100% DPI Flexible Some20 5% DETA/95% HMDA/100% DPI Very Brittle Yes, Brittle Excess Amine21 10% DETA/10% MXDA/80% HMDA/100% DPI Very Brittle Yes, Very Brittle22 5% BHMTA/95% HMDA/100% DPI Brittle Yes, Flexible23 25% DETA/75% HMDA/100% DPI Brittle Yes, Some Brittleness24 10% BHMTA/90% HMDA/100% DPI Flexible Yes, Flexible25 5% DETA/95% HMDA/100% DPI Flexible Yes, Borderline26 5% DETA/95% HMDA/100% DPI Flexible Yes, Flexible27 75/25 MXDA/DETA Brittle Yes, Very Brittle 100% DPI28 50/50 MXDA/DETA Very Brittle Yes, Very Brittle 100% DPI29 25/75 MXDA/DETA Very Brittle Yes, Very Brittle 100% DPI__________________________________________________________________________ .sup.e % DPI is mole percent of diphenyl isophthalate based on total mole of diaryl ester of dicarboxylic acid reacted. BHMTA is bis(hexamethylene)triamine.
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Multilayered structures comprising polycarbonate layers and functionalized polyamide layers exhibit adhesion to each other without the use of a tie layer. The multilayered structures are useful in containers requiring the combined properties of high impact strength and chemical resistance and/or oxygen barrier resistance.
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CROSS REFERENCE TO RELATED APPLICATION(S)
This is a continuation of application Ser. No. 08/346,107 filed on Nov. 28, 1994, now U.S. Pat. No. 5,809,521.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to data communication systems. More specifically, the present invention relates to systems and techniques for synchronizing data transfers across domain boundaries.
While the present invention is described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those having ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications, and embodiments within the scope thereof and additional fields in which the present invention would be of significant utility.
2. Description of the Related Art
In many data communication applications, there is a need to transfer digital data across a domain boundary. In this context, a domain is a system which operates under a single clock signal. A domain boundary then is a border between two systems operating with different clock signals. Data transfers across a boundary must be synchronized and are therefore somewhat problematic.
One technique for achieving a reliable data transfer across a domain boundary is called `speed matching`. Speed matching involves the momentary storage of the data in a first-in, first-out (FIFO) memory and the synchronous communication of control pointers thereto between the transmitting and receiving systems. The FIFO serves as a delay buffer to hold the data until the receiving system can accept the data.
Many FIFO designs are known in the art. In a conventional ripple FIFO memory, data is stored in a pipeline memory and exits after some predetermined number of clocks in first-in, first-out format. Pipeline FIFOs limit the rate at which data may be stored to the rate at which it is read. This "fall-through" delay is equal to the depth of the FIFO. Hence, ripple FIFOs tend to have large fall-through delays and suffer from synchronization problems.
An alternative FIFO design provides a write side into which data is written and a read side from which data is read. In this more popular design, a pointer is used on each side to keep track of the amount of data put in or taken out of the memory. Data is available on the feed side after one clock cycle. While this design tends to suffer less fall-through delay, synchronization problems often persist.
In any event, in these speed matching systems, the size or depth of the memory is an important consideration. U.S. Pat. No. 4,873,703, entitled SYNCHRONIZING SYSTEM, issued Oct. 10, 1989 to Crandall et al. and assigned to the present assignee, the teachings of which are incorporated herein by reference, describes a particularly advantageous speed matching scheme which allows for any degree of synchronization reliability by selecting the number of cascaded synchronizers.
The synchronous communication of control. pointers across the boundary is achieved with a gray coding scheme by which only one bit changes at a time to eliminate hazards during synchronization. This allows flip-flops to be as synchronizers which seize the value associated with the control pointers on each clock cycle. However, since the clock signal is in a different time domain than the originating signal, it could violate the set up or hold time of the flip-flop and the flip-flop could go metastable. In the context, the set up time is the time required for the flip-flop to identify a triggering edge of a clock pulse.
Hence, the referenced patent teaches the use of a FIFO memory with gray encoded control pointers so that only one of the flip-flops on either the read side or the write side can go metastable. Use of a second flip-flop in accordance with a double synchronization scheme provides a full clock cycle for the flip-flop to stabilize in the event that it goes metastable. The term `metastability` refers to an erroneous output resulting from a sampling between a logical `0` state and a logical `1` state. This all helps reduce the chance of failure. The referenced patent teaches a method for determining the correct size of the FIFO to prevent unnecessary holdoff while meeting the synchronization requirement for reliability. Unnecessary holdoff occurs when a data sink and a data source are matched in speed and either sink or source are forced to hold off (even momentarily) from transferring data.
In short, there are three problems associated with the disclosed system. First, the input setup time to the FIFO is dependent on clock skew, capacitive loading (in the data stage of the FIFO) due to routing, capacitive loading due to fanout, intrinsic setup delays of flip-flops, and pad delays. (Set up time is the amount of time that the data must be stable before the triggering edge of the clock appears.) Most of these can be controlled by design, buffer and component selection. However, capacitive loading due to fanout is normally a function of the size of the FIFO. The larger the FIFO, the larger the capacitive load, and thus the larger the setup time requirement.
Secondly, the output delay time from the FIFO is dependent on clock skew, capacitive loading (in the data stage of the FIFO) due to routing, capacitive loading due to fanout, and intrinsic delays of flip-flops, multiplexors (or tristate bus delays), and pads. Most of these can be controlled by design, buffer and component selection. However, intrinsic delay through multiplexors or tristate bus loading are a function of the size of the FIFO. Hence, the larger the FIFO, the larger intrinsic delay through the multiplexor or the larger the delay on the shared tri-state bus.
Thirdly, the overall operational speed of the FIFO is normally dependent on pad delays in combination with the propagation delay of the combinatorial logic in the control section of the FIFO. In large FIFOs, this propagation delay is a significant limitation on the speed of the overall system.
Thus, there is a need in the art for further improvements in the systems and techniques for effecting synchronous data transfers across domain boundaries with minimal error.
SUMMARY OF THE INVENTION
The need in the art is addressed by the present invention which provides an improved multi-stage synchronizer. The inventive synchronizer includes a first memory for storing data, a second memory means connected to the output of said first memory means for storing data, and a third memory for storing data connected to the output of said second memory means. The second memory includes a plurality of multi-stage first-in, first-out memory devices. In a particular embodiment, the first and third memories are implemented with single stage first-in, first-out memories. In a preferred embodiment, the first-in, first-out memories are designed to allow data to be read and written during a single clock cycle after the memory is filled. This is achieved by adding an external read signal to the `not full` signal generated by the device.
The provision of single stage FIFO memories on either side of a multi-stage FIFO memory allows for lower set up time and output delay at higher operational speeds.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1a is a block diagram illustrating the signals connected to the improved N word FIFO of the present invention.
FIG. 1b is a simplified block diagram illustrating the improved multi-stage FIFO design of the present invention.
FIG. 2 is a timing diagram which illustrates the operation of the improved multi-stage FIFO of the present invention.
FIG. 3a is a block diagram illustrating the signals connected to the improved single stage FIFO of the present invention.
FIG. 3b is a schematic diagram of the improved single stage FIFO of the present invention.
FIG. 4 is a timing diagram which illustrates the operation of the advantageous single stage FIFO design of the present invention.
DESCRIPTION OF THE INVENTION
Illustrative embodiments and exemplary applications will now be described with reference to the accompanying drawings to disclose the advantageous teachings of the present invention.
As mentioned above, U.S. Pat. No. 4,873,703, teachings of which are incorporated herein by reference, describes a particularly advantageous speed matching scheme which allows for any degree of synchronization reliability by selecting the number of cascaded synchronizers. The system uses an N word multi-stage FIFO to synchronize data communication between two uncorrelated systems operating within independent time domains.
In accordance with the present teachings, the N word multi-stage FIFO is replaced with an arrangement consisting of two single stage FIFOs and an N-2 stage multi-stage FIFO. FIG. 1a is a block diagram illustrating the signals connected to the improved N word FIFO of the present invention. FIG. 1b is a simplified block diagram illustrating the improved multi-stage FIFO design of the present invention. The improved multistage FIFO 10 is implemented with cascaded first and second single stage synchronous FIFOs 12 and 16 and an N-2 multi-stage asynchronous FIFO 14. In the preferred embodiment, the first and second single stage FIFOs are constructed in the manner set forth more fully below. The multi-stage FIFO 14 is implemented in accordance with the teachings of the above-referenced patent to Crandall et al.
Two uncorrelated clocks (A and B) are applied to the system 10 along with a reset signal which resets the pointers of each FIFO. Data is supplied to the first FIFO 12 by the transmitting system (not shown). Next, a write signal is provided by the transmitting system which is set up to its clock (e.g., Clock A). On the next rising edge of the clock signal, the data on the DATAIN bus will be captured by the FIFO if the write signal is asserted. Each FIFO memory is cascaded by connecting the "not empty" (nEMPTY) signal of one FIFO to the write terminal of the succeeding FIFO, the "not full" (nFULL) signal to the read terminal of the preceding FIFO and the data output terminal (DATAOUT) of one FIFO to the data input (DATAIN) terminal of the succeeding FIFO. The receiving system (not shown) reads data from the second single stage FIFO 16 by asserting a read signal and reading data from the data output terminal thereof. Data is written on one clock pulse and transferred on the next clock pulse.
FIG. 2 is a timing diagram which illustrates the operation of the improved synchronizer of the present invention. Data transfers occur on the leading edges of the clock pulses. DATAAB refers to the transfer of data from the first FIFO 12 to the second FIFO 14. DATABC refers to the transfer of data from the second FIFO 14 to the third FIFO 16. DAVAB means that data is available from the first FIFO 12 to the second FIFO 14. Likewise, DAVBC means that data is available from the second FIFO 14 to the third FIFO 16. The RFD designation refers to a ready for data status. This signals are illustrated on the lines between the FIFOs shown in FIG. 1b.
In operation, when the write signal is asserted (goes high) and data is applied to the DATAIN line, on the leading edge of the next clock pulse the first data packet DATA0 is captured by the first FIFO 12. This is designated with a dot on the write signal and an asterisk (*) on the DATAIN line. Note that this first data packet (DATA0) is also simultaneously made available to the second FIFO 14 hence, the DAVAB signal and the nEMPTY signals go high. This advantageous high speed, low hold off mode of operation is made possible by the unique single stage FIFO design as set forth more fully below.
On the leading edge of the next clock pulse, the next data packet (DATA1) is captured by the first memory 12 and the first data packet (DATA0) is transferred from the first FIFO 12 to the second FIFO 14 and so on. Note that since the FIFO 10 of the present invention is implemented with three FIFOs, three clock cycles are required for data to pass therethrough.
After the read signal is asserted by the receiving system, on the next leading clock edge, output data is read from the data output terminal of the third FIFO 16 if data was available.
FIG. 3a is a block diagram illustrating the signals connected to the improved single stage FIFO of the present invention. FIG. 3b is a schematic diagram of the improved single stage FIFO of the present invention. In practice, the advantageous operation of the present invention may be realized with two stage FIFOs in place of the single stage FIFOs. However, performance may decrease as the size of the first and second FIFOs increase. The single stage FIFOs 12 and 16 include a one word register 20 which is connected to the data input and output lines (DATAIN) and (DATAOUT) respectively, a first circuit 22 for generating a `not full` (nFULL) signal and a second circuit 23 for generating the `not empty` (nEMPTY) signal. Those skilled in the. art will appreciate that, as in conventional systems, where the first FIFO is implemented as an `n` stage FIFO, the register 20 will be an `n` stage register. Use of multi-stage FIFOs in place of the single stage FIFOs, however, may create more capacitance due to fanout. A write signal from the transmitting system is received by a first NAND gate 24, in the first circuit 22, which has a second input provided by a not full signal (nFULL) which is generated in the manner discussed more fully below. The output of the NAND gate provides a load signal to the one word register 20. The output of the NAND gate is also input to a first exclusive OR (XOR) gate 26. The output of the first XOR gate 26 provides the D input for a D flip-flop 28, the Q bar output of which is fed back to provide a second input for the first XOR gate 26. Those skilled in the art will recognize the XOR D flip-flop combination as a traditional T-flop. The Q output of the flip-flop 28 provides a first input to an exclusive NOR (XNOR) gate 30. The second input to the XNOR gate 30 is provided by the Q output of a second D flip-flop 38 which is part of the second circuit 23.
The second circuit 23 includes a second NAND gate 34 which receives a read signal from a receiving system as a first input thereto. A second input to the second NAND gate 34 is provided by the nEMPTY signal in the manner described more fully below. The output of the second NAND gate provides a first input to a second exclusive OR gate 36 which, in turn, provides a D input to the second D flip-flop 38. The Q outputs of the first and second flip-flops 28 and 38, respectively, provide first and second inputs to the XNOR gate 30 and a third XOR gate 40. The third XOR gate 40 provides the nEMPTY signal. The output of the XNOR gate 30 and the read signal are input to an OR gate 32, the output of which provides the nFULL signal.
In operation, a reset signal is supplied which resets the first and second flip-flops 28 and 38, which act as pointers for the data. A write signal is supplied by the transmitting system. Since, the register 20 is empty, the nFULL signal will be high and the output of the NAND gate 24 will be low. This enables the register 20 to load data on the rising edge of the next clock pulse. In addition, the low output of the first NAND gate 24 is combined with high Q bar output of the first flip-flop 28 by the first XOR gate 26. This causes the output of the first XOR gate 26 to go high triggering the first flip-flop 28 and providing a write pointer that indicates that data is available in the register 20.
The operation on the read side is essentially the same with the second flip-flop 38 providing the read pointer. The outputs of the two pointers are compared by the third XOR gate 40. If these pointers are the same, the output of the third XOR gate 40 is low indicating that the register 20 is empty. If the pointers are not equal, the output of the third XOR gate 40 is high indicating that the register 20 is not empty.
A similar comparison is provided by the XNOR gate 30. The inverted output of the XNOR gate 30 essentially allows a `1` to be added to the read pointer. (If the FIFO 12, 16 were implemented as a two stage FIFO, a `2` would be added and so on.) By combining the read signal with the complement of the compare of the two pointers, the FIFO 12, 16 allows for a write on the next cycle if the receiving system is going to read. This allows a single stage FIFO to function with no unnecessary hold off, allowing it to be used and thereby increase the performance of the system.
FIG. 4 is a timing diagram which illustrates the operation of the advantageous FIFO design of the present invention. Again, all changes are relative to the leading edge of the clock and the asterisks (*) indicate words that were actually stored.
When the write signal is asserted and data is provided to the data input bus, on the next clock pulse data is captured by the FIFO and stored in the register 20. At this point, the nEMTPY signal goes high and the nFULL signal goes low. If a read signal is now asserted, the nFULL signal will asynchronously go high, as long as data will be read, data can be output even as data is being written on the next clock pulse. As mentioned above, the unique and advantageous feature of the present FIFO design is afforded by the combination of the read signal with a not full signal. Thereafter, the nFULL signal returns to a high state and the operation continues.
Thus, the present invention has been described herein with reference to a particular embodiment for a particular application. Those having ordinary skill in the art and access to the present teachings will recognize additional modifications, applications and embodiments within the scope thereof.
It is therefore intended by the appended claims to cover any and all such applications, modifications and embodiments within the scope of the present invention. Accordingly,
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An improved multi-stage synchronizer. The inventive synchronizer includes a first memory for storing data, a second memory means connected to the output of said first memory means for storing data, and a third memory for storing data connected to the output of said second memory means. The second memory includes a plurality of multi-stage first-in, first-out memory devices. In a particular embodiment, the first and third memories are implemented with synchronous single stage first-in, first-out memories. In a preferred embodiment, the first-in, first-out memories are designed to allow data to be read and written during a single clock cycle after the memory is full. This is achieved by adding an external read signal to the `not full` signal generated by the device. The provision of single stage FIFO memories on either side of a multi-stage FIFO memory allows for lower set up time and output delay at higher operational speeds.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims the priority, under 35 U.S.C. §119, of German patent application DE 10 2015 217 688.6, filed Sep. 16, 2015; the prior application is herewith incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to a method for avoiding collisions of sheets transported on a transport element with a plurality of inkjet heads fitted above the transport element for printing the sheets. The invention further relates to a method for actuator-based lifting movement and to a device for the actuator-based lifting movement of an inkjet head in order to change the spacing from a printing material transport path of printing materials.
In order to print sheets of paper, board and paperboard in small numbers or with individual printing motifs, the use of digital printing machines is known. When inkjet heads are used for printing the sheets, a respective sheet is moved through under the inkjet heads with minimum spacing by a transport system. Known as transport systems are circulating transport belts, for example implemented as suction belts, and rotating cylinders, so-called jetting cylinders, or circulating tablets, such as are described, for example, in U.S. Pat. No. 8,579,286 B2.
In machine concepts using cylinders, such as are described in patent application publication US 2009/0284561 A1, for example, a plurality of inkjet print heads spaced apart radially are arranged above a jetting cylinder, printing sheets moved past at a short distance from the print heads. A plurality of sheets can be attracted to a jetting cylinder by suction and transported simultaneously. In order to ensure a high printing quality and to avoid damage to the print heads, it is important that a respective sheet lies well on the jetting cylinder.
In addition, it is known to monitor the sheet run and to detect defective sheets or sheets lying defectively. In order to prevent damage to the highly sensitive printing nozzles of an inkjet head by turned-up corners, edges or creases, for example, the printing machine is usually stopped and the defective sheet is removed.
Such a printing machine is described in patent application publication US 2013/0307893 A1. If a defective sheet is detected by a sensor placed upstream of the inkjet heads, not only is the machine stopped but all the inkjet heads are also raised and therefore brought into a withdrawn position. The defective sheets can then be removed without difficulty by the machine operator.
An alternative solution is described in patent application publication US 2015/0116395 A1. In order in the digital web printing machine to avoid collisions of the printing material web with the inkjet heads in the event of a printing material web that is defective, the web run is lowered briefly. In digital sheet-fed printing machines, this solution variant does not represent an option, since the logistical attachment of the transport element located in the area of the inkjet heads to transport elements placed upstream and downstream, for example transfer cylinders, would no longer permit continuous transfer and transport of sheets in the event of being lowered.
The disadvantage with the known method for avoiding collisions in digital sheet-fed printing machines is the high outlay for the manual removal of the defective sheets and the immense impairment to the productivity of the machines because of extended stoppage times.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a method for avoiding collisions which overcomes the above-mentioned and other disadvantages of the heretofore-known devices and methods of this general type and to provide for a process in which as few rejects as possible are produced and in which the productivity of the inkjet print heads is exploited in the best possible way.
A further object is to describe a method for the lifting movement of an inkjet head which can be used for the aforementioned method and in which fault sources resulting from the lifting movement are reduced.
A further object is to devise a device in which printing defects on account of changes in the sheet thickness or on account of printing material thickness fluctuations within a sheet are avoided, as few rejects as possible are produced and in which the productivity of the inkjet print heads is exploited in the best possible way.
With the foregoing and other objects in view there is provided, in accordance with the invention, a method for avoiding collisions of sheets with inkjet heads in a printing machine, the method comprising:
transporting sheets on a transport element (e.g., an impression cylinder, jetting cylinder) past a plurality of inkjet heads disposed above the transport element for printing the sheets;
monitoring the position of a respective sheet upstream of the inkjet heads in a transport direction;
evaluating a measured result from the position monitoring for detecting a defective sheet; and
when a defective sheet is detected, raising a respective inkjet head before the defective sheet reaches the inkjet head.
The first above-mentioned object is achieved by a method for avoiding collisions of sheets, in particular those made of paper, board and plastic, transported on a transport element, with a plurality of inkjet heads fitted above the transport element for printing the sheets, said method comprising the following steps: Permanent monitoring of the position of a respective sheet and the edges and corners thereof—seen in the transport direction—is carried out upstream of the inkjet heads, in particular by using at least one sensor or a camera. An evaluation of the measured result from the position monitoring is carried out by a machine control system for the detection of defective sheets, for example sheets having dog-ears, creases, etc. Depending on the evaluation of the measured result, if necessary a respective inkjet head is raised in each case immediately before a defective sheet reaches this inkjet head, in particular by using an actuator assigned to the inkjet head. In other words, directly before the defective sheet reaches the inkjet head and could possibly damage or even destroy the latter, the inkjet head is raised into a distanced protective position. This means, first of all the first inkjet head, then the second inkjet head, etc, is raised, that is to say the spacing of the respective inkjet head from the transport element or from the sheet is increased. Not all the inkjet heads are raised jointly at once.
Such a method, in which the inkjet heads are raised sequentially, has the advantage that the digital printing machine does not have to be stopped in the event of defective sheets, and its productivity is not unnecessarily reduced on account of stoppage times. In addition, the main drive of the transport element does not have to be designed for very fast stopping either, and in principle it is possible for higher speeds to be run.
In a particularly advantageous and therefore preferred development of the method for avoiding collisions, in a further additional step, immediately after a defective sheet has passed a respective inkjet head, in each case said inkjet head is lowered back into a near printing position. This means that, one after another, the first inkjet head, then the second inkjet head, etc, is each moved back into the original position. The lifting and lowering sequence may be envisioned as a “wave” at a sporting event.
This has the advantage that the quantity of rejects on account of defective sheets is reduced, since, as a result of the sequential raising and lowering of the individual inkjet heads, only the actually defective sheet is not printed; the preceding and also the following sheet, on the other hand, can be printed.
A further advantage results if, following the digital printing station, a varnishing unit is used. On account of the continuous sheet stream, which means that since one sheet follows another and it is possible for one of the sheets also to be a defective sheet, the varnishing unit can be operated continuously, therefore does not have to withdraw from the printing, and thus no further lost sheets are caused by switching the varnishing unit on and off.
In accordance with an alternative embodiment of the method, which has the same advantages, the inkjet head is not lowered as soon as the defective sheet has passed this inkjet head. Instead, the lowering movement is already begun while the defective sheet is still located underneath this inkjet head. This has the additional advantage that the inkjet head can be lowered more slowly and with lower accelerations and, nevertheless, is again located in its lower printing position in good time. For this purpose, it is necessary to raise the inkjet head higher than the defect of the defective sheet actually requires. In other words, a greater time window for the lowering movement is achieved in that a greater travel is covered during the raising action.
In an advantageous development of the method according to the invention, in the second step, a determination, in particular also a classification, of defect sizes is carried out and, depending on the defect size determined, in the following step the travel (i.e., the stroke, the amplitude) for raising a respective inkjet head is predefined by a machine control system. This has the advantage that, in the case of only small defects, only small lifting movements of the inkjet heads are also carried out; in the case of large defects, on the other hand, large lifting movements are required, and these are also carried out. If, according to the method variant described directly above, the lowering movement has already begun early, this is likewise taken into account in this second method step. In the case in which the determination of the defect sizes results in the defect size lying above a predefined maximum permissible limiting value, then, instead of the sequential raising of the inkjet head, immediate raising of all the inkjet heads by a maximum possible travel in the time that is available, that is to say the greatest possible travel, is triggered, by which means additional security against destruction of the inkjet heads is achieved.
In a development of the method, in order to raise and lower a respective inkjet head, in each case an actuator with a control connection to the machine control system and assigned to the inkjet head is provided, for example an electric motor or a piezo actuator. It is particularly advantageous if the actuator is implemented as a servomotor and is driven by a machine control system by means of an oscillation-optimized control profile; this means that a control profile is stored in the machine control system and, for example, can be applied on the basis of the defect size determined. The raising and lowering can in particular be carried out in accordance with the method for actuator-based lifting movement described in more detail below.
In accordance with an refined feature of the invention, the transport element is implemented as a sheet-carrying cylinder, as a so-called jetting cylinder, having a plurality of sheet support surfaces and channels arranged between the sheet support surfaces. According to the invention, respective raising and lowering of the respective inkjet head is carried out while a channel adjoining a defective sheet is passing the inkjet head. In other words: during a first channel passage, the inkjet head is raised, during the next channel passage the inkjet head is lowered again. Thus, the following sheet can already be printed again and the quantity of rejects is minimized.
In an alternative embodiment, the transport element is implemented as a transport table, what is known as a tablet. The sheets are moved through under the inkjet heads by circulating tablets. The raising and lowering of the heads can be done here while a gap between the tablets is passing the heads.
If a first defective sheet is followed by a further defective sheet, then the lowering movement of the inkjet head into its original printing position is omitted and a respective inkjet head remains in its protective position until a following fault-free sheet follows.
The defective sheets can be removed from the material flow before the sheets are stacked and/or delivered. For this purpose, an ejector module is provided in a deliverer of a digital printing machine, for example a diverter or an ejector drum.
With the above and other objects in view there is also provided, in accordance with the invention, a method for actuator-based lifting movement of an inkjet head, which is particularly suitable for use in the context of the above-described methods. The lifting method comprises:
providing an actuator assigned to the inkjet head and a machine control system for activating the actuator;
implementing an oscillation-optimized and inkjet-printing-optimized movement profile, in order to limit oscillations of the inkjet head and to limit pressure fluctuations in the ink supply of the inkjet head, wherein a control profile is stored in the machine control system; and
selectively lifting the inkjet head by activating the actuator assigned to the inkjet head with the machine control system in accordance with the control profile.
In other words, the respective inkjet head is moved with an oscillation-optimized and inkjet-printing-optimized movement profile in order to limit oscillations of the inkjet head and to limit pressure fluctuations in the ink supply of the inkjet head. The control profile is stored in a machine control system and, by means of the machine control system, an actuator assigned to the inkjet head can be activated with the control profile and the actuator moves the inkjet head in accordance with the movement profile.
In accordance with an advantageous feature of the invention, a family of control profiles for a family of movement profiles can be stored in a memory of the machine control system. Thus, for example, a specific size of defect can be assigned a specific movement profile and therefore control profile. In general terms, different movement profiles can thus be provided for different travels. It is particularly advantageous if a respective movement profile maintains defined maximum acceleration limiting values.
An advantageous movement profile is a jerk-limited movement, which can be implemented as an acceleration trapezoid.
With the above and other objects in view there is also provided, in accordance with the invention, a device for actuator-based lifting movement of an inkjet head in order to change the spacing of the inkjet head from a printing material transport path of printing materials. The novel device comprises:
an actuator;
a mechanism for converting a rotational drive movement of the actuator into a translational movement of the inkjet head; and
a compensation system for compensating for a weight of the inkjet head and for bracing the inkjet head against a machine frame of the device.
That is, there is also provided a device for the actuator-based lifting movement of an inkjet head in order to change the spacing of the inkjet head from a printing material transport path. Sheet or web printing materials are moved through underneath the inkjet head on the printing material transport path and can be printed in the process. The device has an actuator, a mechanism for converting a rotational drive movement of the actuator into a translational movement of the inkjet head, and a compensation system for compensating for the weight of the inkjet head, for example by using a compensation weight. The compensation system in an advantageous embodiment can be implemented as a spring system, which braces the inkjet head against a machine frame of the device. Such a device advantageously achieves the situation in which, in the case of a drive error or defect or a power failure, no undesired movement of the inkjet head takes place, neither raising nor lowering. Here, the spring system compensates for the weight of the inkjet head such that the mechanical friction of the actuator, i.e. the self-locking effect thereof, is sufficient in any position to prevent an undesired movement of the inkjet head. Such an undesired movement would be lowering in printing operation or raising from the capping position (in which the nozzles are protected against drying out) outside the operating times.
In accordance with an advantageous feature of the invention, the mechanism is implemented as a coupler mechanism with coupler, lever and drive shaft. This coupler mechanism has the advantage that a lowest possible position of the inkjet head, which can never be undershot, is defined mechanically.
In accordance with a concomitant feature of the invention, the spring system has at least one tension spring or at least one compression spring. In addition, the spring system can have a setting device for adapting the spring tension.
While the invention is described herein with reference to a sheet-fed system, it is also possible, in principle, to implement the same in digital web-fed printing machines. Instead of the sheet run, in this case the web run is monitored, and the web is understood as a “sheet.”
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a method for avoiding collisions, for adapting spacing and for actuator-based lifting movement, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a schematic view of a digital printing machine for carrying out the method according to the invention;
FIG. 2 shows a printing station with print heads that can be raised individually;
FIG. 3 illustrates the lifting movement of a print head;
FIGS. 4A-4C show the raising of a print head with a spring system; and
FIG. 5 shows an alternative embodiment of a print head.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown a sheet-fed printing machine 100 , which is implemented as a digital printing machine. A respective sheet 1000 , coming from a feeder 1 , is transported in the transport direction T through a printing unit 2 to a delivery or deliverer 3 . The transport of the sheet 1000 is primarily carried out by means of cylinders, specifically transfer cylinders 5 and an impression cylinder 10 . Arranged above the impression cylinder 10 , at a spacing distance a from the impression cylinder 10 are inkjet heads 4 . The inkjet heads 4 print a sheet 1000 as it is being moved past at a short distance by the impression cylinder 10 . The impression cylinder 10 is therefore also referred to as a jetting cylinder.
In the illustrated embodiment, the impression cylinder 10 has three sheet-holding regions 11 , which are each separated from one another by a channel 12 . The sheets 1000 are held on the sheet-holding regions 11 by way of grippers 13 .
In order to drive the printing machine 100 , a machine control system 15 with an operator interface and a memory is provided. Viewed in the transport direction T, upstream of the inkjet heads 4 there is arranged a camera or alternatively a sensor 14 , which is used for the permanent monitoring of the sheets 1000 . It is possible to monitor the sheet run or the sheet thickness d. The camera or sensor 14 have a data transmission and transfer connection to the machine control system 15 . Here, the camera or sensor 14 must be arranged far enough upstream of the inkjet heads 4 in order that, even in the event of a defect 1001 (cf. FIG. 2 ) at the sheet trailing edge, a collision of the sheet 1000 and the inkjet heads 4 can still be avoided.
FIG. 2 shows a jetting cylinder 10 with inkjet heads 4 in a detailed illustration and an instantaneous recording. Arranged spaced apart radially from the jetting cylinder 10 are four inkjet heads 4 . 1 , 4 . 2 , 4 . 3 and 4 . 4 , which are all able to execute a lifting movement h. Viewed in the transport direction T, upstream of the inkjet heads 4 there is arranged a sensor 14 for monitoring the sheet run. The sensor 14 has a data transfer connection to the machine control system 15 (illustrated in FIG. 1 ). By means of the sensor 14 , it is possible to check whether sheets 1000 are defective, for example have dog-ears, edges sticking up or creases, whether the sheets 1000 are resting correctly on the jetting cylinder 10 . It is also possible to monitor the thickness d of the sheets 1000 . If a defect on the sheet, i.e. a defective sheet, is identified by the sensor 14 , then the inkjet heads 4 . 1 , 4 . 2 , 4 . 3 and 4 . 4 are raised one after another by actuators (not shown here) driven by the machine control system 15 , to be specific immediately before the sheet 1000 having a defect 1001 reaches the respective inkjet head 4 . 1 , 4 . 2 , 4 . 3 and 4 . 4 . The raising of the inkjet heads 4 is indicated by the double arrow h. In the instantaneous recording shown in FIG. 2 , the inkjet heads 4 . 1 , 4 . 2 and 4 . 3 have already been raised. The first inkjet head 4 . 1 has already reached its protective position, the further inkjet heads 4 . 2 and 4 . 3 are still being raised further into this position. Underneath the fourth inkjet head 4 . 4 there is still a preceding sheet 1000 which is still being finally printed by the inkjet head 4 . 4 . Only subsequently, as soon as the channel 12 of the jetting cylinder 10 passes the inkjet head 4 . 4 , is this fourth inkjet head 4 . 4 also raised. In other words, the raising of the inkjet heads 4 is done separately and sequentially for each individual head 4 . 1 , 4 . 2 , 4 . 3 and 4 . 4 . Each head 4 is raised exactly when the channel 12 passes the inkjet head 4 or “moves through under the latter”. As soon as the defective sheet 1000 with defect 1001 has been moved through under a respective head 4 . 1 , 4 . 2 , 4 . 3 and 4 . 4 , which means that when a following channel 12 adjoining the defective sheet 1001 passes the inkjet heads 4 , the inkjet heads 4 . 1 , 4 . 2 , 4 . 3 and 4 . 4 are lowered again one after another and moved into their printing position. Therefore, a next following sheet 1000 can again be printed normally.
If, for a following sheet 1000 , a defect 1001 is likewise detected by the sensor 14 , then the inkjet heads 4 remain in their protective position and are only lowered into the printing position again later.
If the result of the evaluation of the measured result from the sensor 14 in the machine control system 15 is that the defect 1001 has a size which is above a predefined limiting value, then immediately after the detection all the inkjet heads can be raised immediately and moved by the greatest possible movement travel. As a result, although the quantity of rejects is increased, since the preceding sheet 1000 can no longer be finally printed and the inkjet heads 4 cannot be lowered into the printing position again quickly enough for a following defect-free sheet 1000 , in this way serious damage to the inkjet heads 4 can be avoided. Such raising of the inkjet heads 4 can also be initiated by the machine control system 15 in the case of an emergency stop of the digital printing machine 100 .
For the regular sequential raising and lowering of the inkjet head 4 . 1 , 4 . 2 , 4 . 3 and 4 . 4 one after another, a lifting movement of 15 mm, for example, can be provided. For the common raising of all the inkjet heads 4 in the event of particularly large defects 1001 , a lifting movement h of 50 mm and more, for example, can be provided.
Referring now to FIG. 3 , there is illustrated the mounting of an inkjet head 4 in detail. It is possible to see how the lifting movement h of the print head 4 is implemented. A respective inkjet head 4 can be displaced at right angles to the transport direction T in a horizontal linear guide 16 , in order to be able to move the inkjet head 4 laterally into a maintenance position. This can be done manually or by means of a (non-illustrated) drive. The inkjet head 4 has an integrated print bar 17 which, in addition to the nozzle bar 24 , amongst other things comprises supply modules, such as filters and pressure compensators, not illustrated. The integrated print bar 17 is mounted on a linear guide 18 such that it can be displaced radially with respect to the jetting cylinder 10 . The displacement along this linear guide 18 , which corresponds to the lifting movement h in order to change the spacing of the inkjet head 4 from the jetting cylinder 10 and from the sheet 1000 , is implemented by a drive unit 19 , 20 , 21 , 22 . Mounted on the integrated print bar 17 is a drive shaft 21 which is driven by a servomotor 19 . At the two ends of the drive shaft 21 , that is to say at the drive-side and the operator-side end of the drive shaft 21 , cam disks 20 are seated on the drive shaft 21 and can be rotated by the shaft 21 by means of the drive 19 . The cam disks 20 are in direct contact with a cam roller 22 , which is fitted to the linear guide 18 . By means of the rotation of the drive shaft 21 and therefore of the cam disks 20 , the integrated print bar 17 can be raised and lowered relative to the linear guide 18 by using its cam rollers 22 . For this purpose, the servomotor 19 has a data transfer connection to a machine control system 15 , not illustrated here. In the memory of the machine control system 15 , it is possible to store control profiles which impress a desired movement profile on the integrated print bar 17 and which are optimized with respect to oscillations of the inkjet head 4 and with respect to pressure fluctuations of the ink supply (not illustrated). The power supply of the servomotor 19 is implemented by a drag chain, not illustrated, which also comprises the activation lines of the nozzle bar 24 and the ink supply.
In order to guide the integrated print bar 17 accurately in its lower region and therefore to make the same independent of the exact angular position of the flexibility of the upper linear guides 16 and 18 , supporting rollers 23 are provided, which are firmly connected to the side wall, which means the frame of the sheet-fed printing machine 100 . The side surfaces of the integrated print bar 17 , which are in contact with the supporting rollers 23 , can have appropriately machined contact surfaces. The supporting rollers 23 arranged on one side of the integrated print bar 17 can also be of sprung design. Depending on the arrangement of the supporting rollers 23 , it may also be sufficient to arrange the supporting rollers 23 only on one side of the integrated print bar 17 . During the sequential raising and lowering of the inkjet head 4 with an only small lifting movement h of, for example, 15 to 20 mm, the supporting rollers 23 remain in permanent contact with the integrated print bar 17 and guide the latter. If the inkjet head 4 is raised a great deal in order to avoid a collision on account of a large defect 1001 , which means it executes a large lifting movement h of 50 mm, for example, then the supporting rollers 23 lose contact with the integrated print bar 17 and, during the subsequent lowering and “threading” of the integrated print bar 17 , the lowering speed must if necessary be reduced, so that excessively high excitation of oscillations of the inkjet head 4 does not occur. Such a speed reduction can be depicted by the control profiles stored in the machine control system 15 .
If adaptation of the spacing a of the inkjet head 4 from the jetting cylinder 10 is to be performed in order to adapt to a sheet thickness d, this is likewise possible with the embodiment of the inkjet head 4 illustrated in FIG. 3 . For this purpose, as a rule a very small rotational movement of the servomotor 19 and therefore of the cam disk 20 is sufficient.
Referring now to FIGS. 4A, 4B and 4C , there is illustrated an alternative embodiment of the suspension of the inkjet head 4 . The nozzle bar 24 of an inkjet head 4 is fitted to an end of an integrated print bar by a print head carrier 17 . The print head carrier 17 is connected via a coupler mechanism 28 , 29 to a carrier 27 ; the carrier 27 is in turn mounted by means of a horizontal linear guide 16 on a support beam 26 of the machine frame. In order to set the spacing a of a nozzle plate 24 from a sheet 1000 transported in the transport direction T, a setting movement h is carried out and the print head carrier 17 is moved relative to the carrier 27 . For this purpose, a drive (not illustrated) having a drive shaft 21 is provided. The rotational movement of this drive shaft 21 is converted by the coupler mechanism 28 , 29 with lever 28 and coupler 29 into a vertical movement h. In the illustration of FIG. 4A , the lever 28 is not deflected, is therefore in its zero degree position (0°), and the spacing a between nozzle plate 24 and sheet 1000 is minimal. The coupler mechanism 28 , 29 ensures that the print head 4 cannot be lowered deeper. A collision of the nozzle plate 24 with a transport element 10 is thus reliably prevented. By means of appropriate actuation of the drive with its drive shaft 21 , the print head carrier 17 with its nozzle plate 24 can be raised in the direction h, as emerges from FIGS. 4B and 4C . In the illustration of FIG. 4B , the lever 28 has been rotated as far as its central 90° position, and the spacing a has thus been enlarged. In the illustration of FIG. 4C , the lever 28 has been rotated as far as its stop position of 180°, the maximum spacing a being reached. In order to prevent the print head carrier 17 with its nozzle plate 24 being lowered or raised inadvertently and abruptly, for example, in the case of a fault or a defect of the drive or else in the case of a power failure, a spring system is provided which, in the embodiment according to FIGS. 4A to 4C , has a tension spring 30 , which braces the print head carrier 17 with a carrier 27 . In order to be able to adjust the action in the tension spring 30 , a spring tensioner 32 is provided as setting device. The spring action is set such that the sum of spring force and self-locking of the drive compensates for the weight of the inkjet head and is sufficient to keep the print head carrier 17 in its position.
In the alternative design variant according to FIG. 5 , the spring system has a compression spring 31 .
The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention:
1 Feeder 2 Printing unit 3 Deliverer 4 Inkjet heads 4 . 1 First inkjet head 4 . 2 Second inkjet head 4 . 3 Third inkjet head 4 . 4 Fourth inkjet head 5 Transfer cylinder 6 Drive 10 Impression cylinder (jetting cylinder) (transport element) 11 Sheet-holding region or sheet support surface 12 Channel 13 Gripper 14 Sensor/camera 15 Machine control system 16 Linear guide 17 Integrated print bar with print head carrier 18 Linear guide 19 Drive (servomotor) 20 Cam 21 Drive shaft 22 Cam roller 23 Support roller 24 Nozzle bar 25 Ejector drum 26 Support beam 27 Carrier 28 Lever 29 Coupler 30 Tension spring 31 Compression spring 32 Spring tensioner as setting device 100 Sheet-fed printing machine 1000 Sheet 1001 Defect/fault a Spacing d Sheet thickness h Lifting movement T Transport direction
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A method for avoiding collisions in a digital inkjet printing machine, a method and a device for actuator-based lifting movement of inkjet heads. A sensor/camera monitors the sheets as they travel towards the inkjet heads. In order to avoid collisions, the inkjet heads are raised and lowered again individually and in an oscillation-optimized manner when a defective sheet is detected. The machine does not need to be stopped in the event of defective sheets. Advantageously, rejects can thus be reduced and the performance of the machine can be exploited better.
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CLAIMS OF PRIORITY
[0001] This patent application claims priority from the Provisional Patent Application No. 286/CHE/2008 filed on 1, Feb. 2008.
FIELD OF TECHNOLOGY
[0002] This disclosure relates generally to technical fields of transfer, and store a fresh water through channel system, and in one embodiment to a device to transfer and store fresh water on the sea surface, to collect rain fall occurring on the sea, and to grow vegetation on the sea. the fresh water being that discharged from rivers and above collected rain water.
SUMMARY
[0003] A device, system, and method to transfer and store fresh water on the sea surface, to collect rain fall occurring on the sea, and to grow vegetation on the sea. the fresh water being that discharged from rivers and above collected rain water are disclosed. In one aspect, a device includes a floating channel to transfer fresh water is made of flexible plastic film separator surrounded by a leak detection chambers with sensing electrodes, a floating channel to float on the surface of the sea, a flexible film separator used to separate between fresh water, and the salt water, An Isolator Connector with valve, to connect a channel section with a lift up floats and detachable weight, and an attachment for towing, and anchorage, A rain water collecting film held up by floats to collect rain water falling on the sea is coupled to the floating channel, Floats being multi-chambered with an entrapped air to give buoyancy, and to hold the flexible film, the plastic of floats having ultra violet protection chemicals incorporated,
[0004] A discharge out let to connect between the flexible film, and a floating channel to transfer the fresh water to the floating channel, A flushing out let used to flush out salt contamination when required, A flexible film separator held by floats having storage of fresh water is used to grow vegetation to absorb carbon dioxide from the atmosphere, A harvesting mechanism coupled to a boom carrying brushes to harvest vegetation, and A towing system to ensure a correct designated position of the floating channel and give dynamic stabilization is controlled through a triangulation technique based on a radio transmitter's location on a coast.
[0005] The device may also include the plastic film separator is surrounded by the leakage detection chamber is made of plastic film with embedded wires, the wire being at least of metal wire and conducting polymer wire to which is attached stainless steel electrodes. Increase in electrical conductivity with salt water mixing in case of leakage enables detection of leakage and facilitate repair, the required electronic system is mounted on Isolator Connector. The device further includes the Towing boat with plastic tow lines uses an error signal generated through a microprocessor at least one from triangulation signal transmitted by three antennas on coast, and by GPS signal tow the channel into correct designated position when drifted by waves, and wherein the anchorage is taken where necessary from sea floor by anchor hooks and weight connected by plastic ropes.
[0006] In another aspect, the vegetation growing section may be made of plastic film reinforced with fiber threads, which acts as separator between fresh water and sea water, storing the fresh water, the plastic film being held and surrounded by plastic multi chambered floats, the plastic film having a thin upper layer of new synthesized plastic to enable proper sealing, and a thick bottom layer is made out of a recycled plastic component for strength, the floats have small magnets attached to guide the harvester mechanism.
[0007] In yet another aspect, the vegetation growing section may receive fresh water as rain falling in the section and freshwater delivered from rainwater collected by the rainwater collecting section and from discharge of rivers transferred through open type and closed type channels. In addition, the vegetation may absorb carbon dioxide from the atmosphere through an azola plant, a algae and a rice plant which grows in the stored fresh water, the rice plant being grown by hydroponics method of soil less culture, and the rice being supported by a mesh of plastic float filled with air to provide support and anchorage. Algae is grown using sea water where necessary, and vegetation growing section enables application of fertilizer thereby enabling good growth. The peripheral border of area having vegetation growing sections has plastic mesh net suspended downwards by weights and held up by floats to give protection from fish where necessary. The harvester mechanism coupled to a boom carrying brushes to harvest vegetation is automated with robotic systems fitted on a small boat.
[0008] The device, systems, and methods disclosed herein may be implemented in any means for achieving various aspects, and may be executed in a form of a machine-readable medium embodying a set of instructions that, when executed by a machine, cause the machine to perform any of the operations disclosed herein. Other features will be apparent from the accompanying drawings and from the detailed description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Example embodiments are 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:
[0010] FIG. 1 is a system view of a device illustrating an open, and closed type channel to transfer and store a fresh water that may be connected to a rain water collector, and a vegetation section, according to one embodiment.
[0011] FIG. 2 is a cross section view of the open channel, according to one embodiment.
[0012] FIG. 3 is a top view of the open channel, according to one embodiment.
[0013] FIG. 4 is a cross section view of the closed channel, according to one embodiment.
[0014] FIG. 5 is a side view of the closed channel, according to one embodiment.
[0015] FIG. 6 is a side view of the open channel, according to one embodiment.
[0016] FIG. 7 is a side view of the closed channel, according to one embodiment.
[0017] FIG. 8 is a cross section view of a towing boat, according to one embodiment.
[0018] FIG. 9 is a system view of below chamber with isolator to cross ships, according to one embodiment.
[0019] FIG. 10 is a system view of a ‘U’ shaped connectivity chamber, according to one embodiment.
[0020] FIG. 11 is a cross section view of a rain water collecting film, according one embodiment.
[0021] FIG. 12 is a top view of a rain water collecting film, according one embodiment.
[0022] FIG. 13 is a cross section view of vegetation growing section, according to one embodiment.
[0023] FIG. 14 is a cross section view of vegetation growing section that includes spacer mesh, and floating mesh, according to one embodiment.
[0024] FIG. 15 is a top view of vegetation growing section, according to one embodiment.
[0025] FIG. 16 is a system view of a harvesting mechanism, according to one embodiment.
[0026] FIG. 17 is a system view illustrating rotating boom, according to one embodiment.
[0027] Other features of the present embodiments will be apparent from the accompanying drawings and from the detailed description that follows.
DETAILED DESCRIPTION
[0028] A device, system and method to transfer and store fresh water on the sea surface, to collect rain fall occurring on the sea, and to grow vegetation on the sea. the fresh water being that discharged from rivers and above collected rain water are disclosed. Although the present embodiments have been described with reference to specific example embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of the various embodiments.
[0029] FIG. 1 is a system view of a device illustrating an open, and closed type channel to transfer and store a fresh water that may be connected to a rain water collector, and a vegetation section, according to one embodiment. Particularly, FIG. 1 illustrates an open channel 102 , a rain water collecting film 104 , a vegetation growing section 106 , an isolator connector 108 , and a flush outlet 110 , according to one embodiment.
[0030] The open channel 102 (e.g., a plastic component) may be used to transfer a fresh water which may be discharged from the river is floating on the surface of the sea. The rain water collecting film 104 may be used to collect the rain water falling on the sea that may be coupled to the floating open channel 102 . The vegetation growing section 106 (e.g., made of plastic film) may act as a separator between a fresh water and a sea water. This section having storage of fresh water is used for vegetation to absorb carbon dioxide from the atmosphere. The vegetation growing section 106 is connected to the open channel 102 . The isolator connector 108 (e.g., may be made of rigid plastic frame with latch) with a drop down valve may be used to connect a channel section with a lift up floats with detachable weights. The isolator connector 108 may also be used to detach, and attached back the floating channel during severe storm, to pass wave energy, to prevent damage to the device, and accidental collusion with ships. The flush out let 110 of the rain water collecting film 104 may be used to flush out the salt contamination as and when required.
[0031] In example embodiment, the open channel 102 with the isolator connector 108 may be coupled to the rain water collecting film 104 , and the vegetation growing section 106 to transfer and store the fresh water 206 .
[0032] FIG. 2 is a cross section view of the open channel, according to one embodiment. Particularly, FIG. 2 illustrates a leak protection chamber 202 , fresh water 204 , a float 206 , electrodes 208 , and a netting 210 , according to one embodiment.
[0033] The leak protection chamber 202 may be used to detecting the leakages of fresh water in the channel (e.g., may be open type, and closed type channel). The fresh water 204 may be the pure and sweet water discharged from the rivers that may be transferred from the channel. The float 206 (e.g., flexible, and made of plastic film component) may be connected at the end of the channel which may be used to float the channels on the surface of the sea. The electrodes 208 attached in the channel is used to sense the salt water leakage in the channel. The netting 210 may be spread over to protect the channel from the fish, and sharks.
[0034] In example embodiment, the open channel 102 that may be connected to the leak detection chamber 202 , the electrodes 208 . The open channel 102 may be connected to the float 206 at both the ends of the channel. The netting 210 is used to protect the channel.
[0035] FIG. 3 is a top view of the open channel, according to one embodiment. Particularly, FIG. 3 illustrates the isolator 108 , the fresh water 204 , the float 206 , and the tow line 302 , according to one embodiment.
[0036] The towing line 302 made of plastic may be used error signal to generated through the microprocessor from triangulation signal transmitted by three antennas on the coast for correct designated position of the floating channel.
[0037] In example embodiment, the top of the open channel 102 may be attached with the isolator connector 108 with a tow line 302 .
[0038] FIG. 4 is a cross section view of the closed channel, according to one embodiment. Particularly, FIG. 4 illustrates the leak detection chamber 202 , the fresh water 204 , and the electrodes 206 , according to one embodiment.
[0039] FIG. 4 illustrates another type channel called the closed type channel to collect and transfer the fresh water 204 along with the electrodes 206 and the leak detection chamber 202 which may be used to detect the salt water leakage in the channel. The functionality of the open type channel and the closed type channel is similar.
[0040] FIG. 5 is a side view of the closed channel, according to one embodiment. Particularly, FIG. 5 illustrates the fresh water 204 , a drop down valve 502 , and the latching connector to drop down valve 504 , according to one embodiment.
[0041] The drop down valve 502 (e.g., the drop down valve, the butterfly valve, and the flap valve) may be connected to the isolator connector may be directional to take advantage of wave to get forward flow, and to take back flow of the device. The latching connector to drop down valve 504 may be used to control the drop down valve of the isolator connector.
[0042] FIG. 5 illustrates the drop down valve 502 with latching connector of the isolator of the closed channel.
[0043] FIG. 6 is a side view of the open channel, according to one embodiment. Particularly, FIG. 6 illustrates the isolator 108 , the fresh water 204 , the float 206 , the tow line 302 , the drop down valve 502 , a signal board with blinking LED 602 , a damper film structure 604 , an anchorage to sea floor 606 , and a detachable weight 608 , according to one embodiment.
[0044] The signal board with blinking. LED 602 is carried on the isolator connector to warm ships, and fishing boat from approaching the channel. The damper film structure 604 may be suspended in deeper part of sea, is attached to the Isolator Connector 108 . The anchorage to sea floor 606 may be taken wherever necessary by anchor hooks connected to the plastic ropes for stabilization of the floating channel. The detachable weight 608 may be provided to the isolator connector 108 of the floating channel during severe storm, and accidental collusion with the ships.
[0045] FIG. 6 illustrates a side view of the open channel having isolator connector 108 connected upwardly to the signal board with blinking LED 602 , the drop down valve 502 . The anchorage to sea floor 606 and the damper film structure 604 are also provided to the isolator connector 108 for stabilization of the device.
[0046] FIG. 7 is a side view of the closed channel, according to one embodiment. Particularly, FIG. 7 illustrates the fresh water 204 , the tow line 302 , the drop down valve 502 , the signal board with blinking LED 602 , and electrodes for shark repulsion 702 , according to one embodiment.
[0047] The electrodes 702 (e.g., may be stainless steel) attached to the isolator connector 108 downwardly may be used to repel sharks from the device.
[0048] FIG. 8 is a cross section view of a towing boat, according to one embodiment. Particularly, FIG. 8 illustrates the tow line 302 , an antenna 802 A-C, an antenna 804 , and a microprocessor 806 , according to one embodiment.
[0049] The antenna 802 A-C may be mounted on the coast to transmit triangulation signal for the corrected designated position of the floating channel. The antenna 804 is mounted in the towing boat to keep the channel in correct position when drifted by waves. The microprocessor 806 may, be used to generate error signal that may be used by the towing boat with plastic tow line to place the floating channel in correct designated position when drifted by waves.
[0050] FIG. 8 illustrates the towing boat with plastic tow line along with the antenna 804 and the microprocessors 806 using the error signal generated through the microprocessor 806 from the triangulation signal transmitted by the three antennas on the coast, and by GPS signal tow the channel into correct designated position when drifted by waves.
[0051] FIG. 9 is a system view of below chamber with isolator to cross ships, according to one embodiment. Particularly, FIG. 9 illustrates a below chamber 902 . The below chamber 902 may be pulled in by a pair of cables that may be driven by motor to allow large ships. The open type, and the closed type channels may have below chambers 902 .
[0052] FIG. 10 is a system view of a ‘U’ shaped connectivity chamber, according to one embodiment. Particularly, FIG. 10 illustrates the floating channel having ‘U’ shape connecting chamber 1002 (e.g., made of rigid material with swivel joints) may be used to allow the ships to cross the channel without damaging the device. The ‘U’ shaped connecting chamber 1002 may be in horizontal position which may be dip down to vertical position using the ships force allowing ships to cross and return to horizontal position after the crossing of ships.
[0053] FIG. 11 is a cross section view of a rain water collecting film, according one embodiment. Particularly, FIG. 11 illustrates the flush outlet 110 which has a valve, and a discharge outlet 1102 which has a valve, according to one embodiment. FIG. 11 illustrates the collection of rain water through the rain water collecting film coupled to the float 206 . The discharge outlet 1102 may be used to discharge the collected rain water to the open and closed type channels. Condensed water collector 1104 is provided on the underside of the film to collect condensed fresh water that condenses on underside.
[0054] FIG. 12 is a top view of a rain water collecting film, according one embodiment. Particularly, FIG. 12 illustrates the top view of the rain water collecting film that may be connected to the open channel 102 along with flush outlet 110 , and the discharge outlet 1102 .
[0055] FIG. 13 is a cross section view of vegetation growing section, according to one embodiment. Particularly, FIG. 13 illustrates the cross section view of the vegetation growing section 106 (e.g., made of plastic film to act as separator between fresh water, and salt water) allowing storage of fresh water in the floating section which may be used to grow vegetation (e.g., may be azola plant) to absorb carbon dioxide from atmosphere.
[0056] FIG. 14 is a cross section view of vegetation growing section that includes spacer mesh 1201 , and floating mesh 1202 , according to one embodiment. Particularly,
[0057] FIG. 14 illustrates growing of rice plant in the vegetation growing section 106 that may be supported by a mesh of plastic float filled with air to provide support.
[0058] FIG. 15 is a top view of vegetation growing section, according to one embodiment. Particularly, FIG. 15 illustrates magnets 1502 may be attached to the float 206 to guide the harvesting mechanism.
[0059] FIG. 16 is a system view of a harvesting mechanism, according to one embodiment. Particularly, FIG. 16 illustrates the harvesting mechanism that may be coupled to the boom carrying brushes, and cable drive to harvest vegetation.
[0060] FIG. 17 is a system view illustrating rotating boom, according to one embodiment. Particularly, FIG. 17 illustrates the harvesting mechanism which may be coupled to the boom carrying brushes 1204 to harvest vegetation may be automated with robotic system fitted on a small boat 1205 .
[0061] Although the present embodiments have been described with reference to specific example embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of the various embodiments.
[0062] In addition, it will be appreciated that the various operations, processes, and methods disclosed herein may be embodied in a machine-readable medium and/or a machine accessible medium compatible with a data processing system (e.g., a computer system), and may be performed in any order (e.g., including using means for achieving the various operations). Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.
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A device, system, and method of transfer and store fresh water on the sea surface, to collect rain fall occurring on the sea, and to grow vegetation on the sea through discharged fresh water from rivers and above collected rain water are disclosed. In one embodiment, a device includes a floating channel to transfer fresh water is made of flexible plastic film separator surrounded by a leak detection chambers with sensing electrodes, a rain water collecting film held up by floats to collect rain water falling on the sea is coupled to the floating channel, a flexible film separator held by floats having storage of fresh water is used to grow vegetation to absorb carbon dioxide from the atmosphere, and a towing system to ensure a correct designated position of the floating channel giving dynamic stabilization controlled through a triangulation technique based on a radio transmitter's location on a coast.
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BACKGROUND OF THE INVENTION:
This invention relates to a method and apparatus for automatically giving and receiving orders and for making calculation thereof in restaurants and shops, which on-line systematizes a series of works including from the giving and receiving of orders until the issue of calculation slips between the cookers' sections and the orderers' sections.
In restaurants such as "sushi" shops which carry on the face-to-face sales by making various kinds of goods to order, cookers used to calculate by heart the amount on hand for the received orders during making goods to rush orders from many orderers.
Under these circumstances, in the case when there occurred rush orders received from many orderers, cookers had to make and supply in turn the goods of orders received to the orderers to the best of their ability, and consequently the cookers as well as the orderers had sometimes doubts about accuracy of the calculation of the amount.
Further, in public restaurants, there exists the system such that waiters or porters receive orally orders from orderers, and hand over the slip on which they entered orders to cookers, so that sometime orderers cannot give orders by selecting with care the goods which meet budget and taste according to the manner of waiters.
SUMMARY OF THE INVENTION
This invention relates to a method and apparatus for smoothly giving and receiving orders between clients and cooker in restaurants and shops or the like by useing a microcomputer.
The object of the present invention is to provide a method and apparatus for automatically giving and receiving orders and for making calculation thereof in restaurants and shops, in which an order input unit for giving orders is provided in each of orderers' sections, said order input unit indicating good names and prices, a received order indicator and a giving and receiving of orders controlling and calculating device thereof are provided in each of cookers' sections, whereby a series of works including from the giving and receiving of orders until the issue of calculation slips are on-line systematized between the cookers' sections and the orderers' sections.
Another object of the present invention is to provide a method and apparatus for automatically giving and receiving orders and for making calculations thereof in restaurants and shops, in which an order input unit for giving orders is provided in each of orderers' sections, said order input unit indicating names and prices of goods, a received order indicator and a giving and receiving of orders controlling and calculating device thereof are provided in each of cookers' sections, whereby a series of works including from the giving and receiving of orders until the issue of calculation slips are on-line systematized between the cookers' sections and the orderers' sections.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of the arrangement for the main portion of one embodiment;
FIG. 2 is a plan view of one example for the display of the order input unit;
FIG. 3 is a plan view of the received order indicator;
FIG. 4 is a plan view of the giving and receiving orders controlling and calculating device thereof;
FIG. 5 is a plan view of the other indicator;
FIG. 6 is a front view of a microcomputer;
FIG. 7 is a block diagram of the present invention;
FIG. 8 is a flow chart showing the operation by order; and
FIG. 9 is a flow chart showing the operation by cookers.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings, one embodiment of this invention will be explained in the following.
In FIG. 1, there is shown a plan view of the arrangement for the main portion of the embodiment for an automatic apparatus for giving and receiving orders and for making calculation thereof in "sushiya" restaurants according to this invention.
There are provided a predetermined number of seats 2 in the outside of the service counter 1 and also provided a cooker seat 3 in the inside thereof.
On the service counter 1 is provided the order input unit 4 at the position corresponding to each of the ten seats 2 from No. 0 to No. 9, said order input unit 4 indicating goods names and prices.
On the service counter 1 is provided the received order indicator 5 and the giving and receiving of orders controlling and calculating device 6.
The output produced from the order input unit 4 by touching of a light pen 7 provided on the service counter 1 at the position corresponding to every seat is inputted into a microcomputer 8.
In FIG. 2, on the surface of the order input unit 4 is provided a goods name table 9 having a plurality of well regulated goods name sections 9a, each of which designates the names of goods and prices.
According to this embodiment, in said goods names sections 9a, the first lateral column designates names of drinks, salad and fruits, and the second to fifth lateral columns designate respectively names of hand-shaked "sushi", and at the upper left corner, there are indicated the prices per two pieces of the goods designated in the left half portion of said second to fifth lateral columns, and also at the upper right corner, there are indicated prices per two pieces of the goods designated in the right half portion of said second to fifth lateral columns. On the other hand, the sixth lateral column of the table 9 designate names of roll-shaped "sushi" and prices per piece.
Further, on the surface of said order input unit 4 are provided a non-"wasabi" instruction section 10, a non-"wasabi" instruction acknowledging a cancellation instructing section 13, lamp 11, an order instructing section 12, a total amount calculation instructing section 14, an operation acknowledging lamp 15, an order contents monitor 16, and a direction to handling 17.
In said goods name section 9a, there are indicated a circular mark 9b which shows the place to be touched by a light-pen 7, and also provided a lamp 9c which acknowledges given orders by touching said light pen on said circular mark.
As shown in FIG. 3, the received order indicator 5 is provided with a table 18 having a plurality of sections 18a which indicate by lighting the name of goods one by one in turn of orders received and with a digital indication section 18b.
In this embodiment, the Table 9 of the input unit 4 comprises six lateral columns and eight vertical columns and also the table 18 of the indicator 5 has the same structure as in the table 9 so that the goods name in the cross portions of the lateral column and the vertical column in the table 9 corresponds to the goods name in the cross portion of these columns in the table 18.
As shown in FIG. 4, the device for control of the giving and receiving orders and for calculation 6 is provided with a seat number key 19, a received order balance key 20, a seat number clear key 21, a total amount calculation key 22, a next order confirmation key 23, a supply completion key 24, a seat shift key 25, a carrying back order key 26, an order cancellation key 27, a total amount calculation slip issuing printer 28, and in which said supply completion key 24 is also used for a price amendment key.
The order of the goods indicated in the first lateral column in the goods name section 9 of said order input unit 4 is shown in an indicator 30 in FIG. 5.
Said indicator 30 is provided with a goods names indicating section 31 which indicates the orders received by lighting and an orderer seat number indicating section 32 and also provided internally with a sound mechanism 33 such as orgel, chime, bell and silen which actuates by giving an order. And said indicator 30 is also provided with a supply key 34 which is pushed by the cooker when ordered goods are supplied to the orderers and a next order confirmation key 35. Further, a lamp 36 for indicating order received is provided below each of the goods name sections.
The actuation of the sound mechanism is stopped by pushing the supply key 34.
All of the signals from each of the order input unit 4, the received order indicator 5, the giving and receiving of orders controlling and calculating device 6 and the indicator 30 are memorized in the micro-computer 8 and outputted according to necessity.
As shown in FIG. 6, the micro-computer 8 having a central processing unit (C. P. U.) is provided with an operation dial 37.
FIG. 7 shows block diagram of the present invention.
The apparatus of this invention as constituted above can be used as mentioned below. Firstly, when orderers take their seats 2, and find the operation confirmation lamp 15 of the order input unit 4 being lighted, they can commence their orders. In other words, by lighting of this operation confirmation lamp 15, the orderer in said seat can note that the order has become possible. Nextly, the orderer touches the order instruction section 12 of the order input unit 4 with light pen 7 and then touches the portion of the name of goods the orderer desires in the goods name table 9. By this operation, the portion which shows the ordered goods names in the received order indicator 5 at the cooker's section is lighted and flashed, and consequently the cooker can note the contents of the received order.
For example, when the orderer at the seat 3 orders a cuttlefish (IKA in Japanese) which is indicated in the crossing portion of the 3rd lateral column and the 4th vertical column on the goods names sections 9 of the order input unit 4, the indication of said cuttlefish in the cross portion of the 3rd lateral column and the 4th vertical column on the section 18 of the received order indicator 5 appears by lighting and flashing.
In this case, when the orderer asks for the non-"wasabi" instruction and touches with the light pen 7 to the non-"wasabi" instruction section 10, the number "0" is digitally indicated on the left side of the seat number of orderer of the section 18b of the received order indicator 5, by which the non-"wasabi" instruction is received by the cooker.
Then, when said number "0" is digitally indicated, the non-"wasabi" instruction acknowledging lamp 11 in the order input unit 4 is lighted by which the orderer can acknowledge the fact that his instruction for non-"wasabi" was received by the cooker.
Even when orders are given by other orderers, the indications in the sections 18, 18b are made in turn by the memory of the micro-computer 8, namely these indications are never made at the same time.
After the cooker acknowledges the fact that the orderer of the seat No. 3 has given the order of a cuttlefish with non-"wasabi" instruction, said cuttlefish being indicated in the crossing portion of the 3rd lateral column and the 4th vertical column on the goods name section 9, and then hands the prepared goods to the orderer of the seat No. 3, he pushes the supply completion key 24 of the giving and receiving of orders controlling and calculating device 6, by which the indications of the sections 18, 18b are cancelled and the contents of next order are indicated in said sections.
The digital number indicated on the right side of the seat number indication of the section 18b shows the number of the goods given in the same kind. When the indication of the sections 18, 18b are cancelled by pushing the supply completion key 22, the indication of the next order appears in the same sections.
However, when the new orderer asks for the non-"wasabi" instruction, the "0" number indication is cancelled. In the case that the order of cuttlefish in the crossing portion of the 3rd lateral column and the 4th vertical column on the goods name section 9 is not subsequently received, the "1" number indication on the right side of the seat number has remained as it is.
On the other hand, in the case that the cooker wants to confirm the subsequent orders during cooking, he can do it by means of pushing the next order confirmation key 23 of the giving and receiving of orders controlling and calculating device 6, by which the indication of goods names of the received orders appears in the section 18 and the number of the received orders appears on the right side of the section 18b.
Further, when the cooker notices the fact that the stock of the goods ordered by the orderer runs out and pushes the cancellation key 27, the indication of the name of said goods ordered by operating the order input unit 4 in the seat of orderer is cancelled, and at the same time the indication of the order contents monitor 16 is also cancelled. In such case, the orderer will give the order for another goods or terminate his eating and drinking.
When the eating and drinking are terminated, the amounts of costs of the goods supplied in each of the orderers' seats are added and memorized by the micro-computer 8. Accordingly, it is possible to issue the calculation slip on which the particulars of the costs are printed through the printer 25 simply by pushing the calculation key 22 and the seat number key 19. Consequently, the cooker can hand the slip to the orderer, and the orderer can pay the eating and drinking costs with the slip.
FIG. 8 is a flow chart showing the operations by orderers, and FIG. 9 is a flow chart showing the operations by cookers.
As will be noted clearly, according to the appartus of this invention in which a series of works including from the giving and receiving of orders until the issue of calculation slips are on-line systematized between the cookers' sections and the orderers' sections, there are excellent advantages such that the cookers do not need to calculate by heart the amounts of the received orders and that the orderers can give the orders confirming the amount on hand of the ordered goods.
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The method and apparatus of this invention can be used for smoothly giving and receiving orders between clients and cookers in restaurants and shops or the like so that clients can order the goods at their own discretion and calculation and also so that cookers can receive smoothly their orders and supply the made good to clients in turn of the received orders and make automatically calculation of the particulars and the total amount of the goods given by clients.
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INTRODUCTION AND BACKGROUND
[0001] The present invention provides a process for the fermentative production of L-amino acids, in particular L-lysine, using coryneform bacteria, in which the csp1 gene is attenuated. All references cited herein and throughout this application are expressly incorporated by reference by the term I.B.R. following the citation.
[0002] 1. Prior art
[0003] L-Amino acids, in particular L-lysine, are used in animal nutrition, human medicine and the pharmaceuticals industry. It is known that these amino acids are produced by fermentation of strains of coryneform bacteria, in particular Corynebacterium glutamicum. Due to their great significance, efforts are constantly being made to improve the production process.
[0004] Improvements to the process may relate to measures concerning fermentation technology, for example stirring and oxygen supply, or to the composition of the nutrient media, such as for example sugar concentration during fermentation, or to working up of the product by, for example, ion exchange chromatography, or to the intrinsic performance characteristics of the microorganism itself.
[0005] The performance characteristics of these microorganisms are improved using methods of mutagenesis, selection and mutant selection. In this manner, strains are obtained which are resistant to antimetabolites, such as for example the lysine analogue S-(2-aminoethyl)cysteine, or are auxotrophic for regulatorily significant metabolites and produce L-amino acids.
[0006] For some years, methods of recombinant DNA technology have likewise been used to improve strains of Corynebacterium which produce L-amino acids by amplifying individual biosynthesis genes and investigating the effect on L-amino acid production. Review articles on this subject may be found inter alia in Kinoshita (“Glutamic Acid Bacteria”, in: Biology of Industrial Microorganisms, Demain and Solomon (Eds.), Benjamin Cummings, London, UK, 1985, 115-142) I.B.R., Hilliger (BioTec 2, 40-44 (1991)) I.B.R., Eggeling (Amino Acids 6:261-272 (1994)) I.B.R., Jetten and Sinskey (Critical Reviews in Biotechnology 15, 73-103 (1995)) I.B.R. and Sahm et al. (Annuals of the New York Academy of Science 782, 25-39 (1996)) I.B.R.
[0007] L-amino acids, in particular lysine, are used in human medicine and in the pharmaceuticals industry, in the food industry and very particularly in animal nutrition. There is accordingly general interest in providing novel improved processes for the production of amino acids, in particular L-lysine.
[0008] Any subsequent mention of L-lysine or lysine should be taken to mean not only the base, but also salts, such as for example lysine monohydrochloride or lysine sulfate.
SUMMARY OF THE INVENTION
[0009] An object of the invention is to provide improved processes for the fermentative production of L-amino acids, and in particular L-lysine, using coryneform bacteria.
BRIEF DESCRIPTION OF THE FIGURES
[0010] [0010]FIG. 1 is a Map of the plasmid pKl8mobsacBΔcsp1.
DETAILED DESCRIPTION OF THE INVENTION
[0011] The above and other objects of the invention can be achieved by a process for the fermentative production of L-amino acids, in particular L-lysine, using coryneform bacteria in which at least the nucleotide sequence coding for the Csp1 gene product (csp1 gene) is attenuated. When csp1 gene is attenuated, and in particular expressed at a low level, the desired product is accumulated in the medium or in the cells and the L-amino acid is isolated.
[0012] The strains used preferably already produce L-amino acids, and in particular L-lysine, before the csp1 gene is attenuated. In this connection, the term “attenuation” means reducing or suppressing the intracellular activity of one or more enzymes (proteins) in a microorganism, which enzymes are coded by the corresponding DNA (in this case the csp1 gene). For example attenuation may be accomplished by using a weak promoter or a gene or allele which codes for a corresponding enzyme which has a low activity or inactivates the corresponding gene or enzyme (protein) and optionally by combining these measures.
[0013] The microorganisms, provided by the present invention, may produce amino acids, in particular lysine, from glucose, sucrose, lactose, fructose, maltose, molasses, starch, cellulose or from glycerol and ethanol. The microorganisms may comprise representatives of the coryneform bacteria in particular of the genus Corynebacterium. Within the genus Corynebacterium, the species Corynebacterium glutamicum may in particular is mentioned, which is known among specialists for its ability to produce L-amino acids.
[0014] Suitable strains of the genus Corynebacterium, in particular of the species Corynebacterium glutamicum, are especially the known wild type strains
Corynebacterium glutamicum ATCC13032 Corynebacterium acetoglutainicum ATCC15806 Corynebacterium acetoacidophilum ATCC13870 Corynebacterium melassecola ATCC17965 Corynebacterium thermoaminogenes FERM BP-1539 Brevibacterium flavum ATCC14067 Brevibacterium lactofermentum ATCC13869 and Brevibacterium divaricatum ATCC14020
[0015] also mutants or strains produced therefrom which produce L-amino acids, such as for example the L-lysine producing strains
Corynebacterium glutamicum FERM-P 1709 Brevibacterium flavum EERM-P 1708 Brevibacterium lactofermentum FERM-P 1712 Corynebacterium glutamicum FERM-P 6463 Corynebacterium glutamicum FERN-P 6464 and Corynebacterium glutamicum DSM 5714.
[0016] It has been found that coryneform bacteria produce L-amino acids, in particular L-lysine, in an improved manner once the csp1 gene has been attenuated.
[0017] The csp1 gene codes for the PS1 protein, which has not yet been proven to have any enzymatic activity. The nucleotide sequence of the csp1 gene has been described by Joliff et al. (Molecular Microbiology 1992 Aug; 6 (16):2349-62) I.B.R. The sequence is generally available under accession number g40486 from the nucleotide sequence database of the National Center for Biotechnology Information (NCBI, Bethesda, Md., USA) I.B.R. The csp1 gene described in the stated references may be used according to the invention. Alleles of the csp1 gene arising from the degeneracy of the genetic code or from functionally neutral sense mutations may also be used.
[0018] Attenuation may be achieved by reducing or suppressing either expression of the csp1 gene or the catalytic properties of the gene product. Both measures are optionally combined.
[0019] Gene expression may be reduced by appropriate control of the culture or by genetic modification (mutation) of the signal structures for gene expression. Signal structures for gene expression are, for example, repressor genes, activator genes, operators, promoters, attenuators, ribosome binding sites, the start codon and terminators.
[0020] The person skilled in the art will find information in this connection for example in patent application WO 96/15246 I.B.R., in Boyd & Murphy (Journal of Bacteriology 170: 5949 (1988)) I.B.R., in Voskuil & Chambliss (Nucleic Acids Research 26: 3548 (1998)) I.B.R., in Jensen & Hammer (Biotechnology and Bioengineering 58: 191 (1998)) I.B.R., in Patek et al. (Microbiology 142: 1297 (1996)) I.B.R. and in known textbooks of genetics and molecular biology, such as for example the textbook by Knippers (“Molekulare Genetik”, 6th edition, Georg Thieme Verlag, Stuttgart, Germany, 1995) I.B.R. or by Winnacker (“Gene und Klone”, VCH Verlagsgesellschaft, Weinheim, Germany, 1990) I.B.R.
[0021] Mutations which give rise to a change or reduction in the catalytic properties of enzyme proteins are known from the prior art; examples which may be mentioned are the papers by Qiu and Goodman (Journal of Biological Chemistry 272: 8611-8617 (1997)) I.B.R., Sugimoto et al. (Bioscience Biotechnology and Biochemistry 61: 1760-1762 (1997)) I.B.R. and Mbckel (“Die Threonindehydratase aus Corynebacterium glutamicum: Aufhebung der allosterischen Regulation und Struktur des Enzyms”, Berichte des Forschungszentrums Julichs, Jul-2906, ISSN09442952, Julich, Germany, 1994) I.B.R.
[0022] Summary presentations may be found in known textbooks of genetics and molecular biology such as, for example, the textbook by Hagemann (“Allgemeine Genetik”, Gustav Fischer Verlag, Stuttgart, 1986) I.B.R.
[0023] Mutations which-may be considered are transitions, transversions, insertions and deletions. Depending upon the effect of exchanging the amino acids upon enzyme activity, the mutations are known as missense mutations or nonsense mutations. Insertions or deletions of at least one base pair in a gene give rise to frame shift mutations, as a result of which the incorrect amino acids are inserted or translation terminates prematurely. Deletions of two or more codons typically result in a complete breakdown of enzyme activity.
[0024] Instructions for producing such mutations belong to the prior art and may be found in known textbooks of genetics and molecular biology, such as for example the textbook by Knippers (“Molekulare Genetik”, 6th edition, Georg Thieme Verlag, Stuttgart, Germany, 1995) I.B.R., by Winnacker (“Gene und Klone”, VCH Verlagsgesellschaft, Weinheim, Germany, 1990) I.B.R. or by Hagemann (“Allgemeine Genetik”; Gustav Fischer Verlag, Stuttgart, 1986) I.B.R.
[0025] One example of a mutated csp1 gene is the Δcsp1 allele contained in the plasmid pKl8mobsacBΔcsp1 (FIG. 1). The Δcsp1 allele only contains sequences from the 5′ and 3′ ends of the csp1 gene; a section of 1690 bp in length of the coding region is absent (deletion). This Δcsp1 allele may be incorporated into coryneform bacteria by integration mutagenesis.
[0026] The above-stated plasmid pKl8mobsacBΔcsp1, which is not replicable in C. glutamicum, is used for this purpose. After transformation and homologous recombination by means of a first “crossing over”, which effects integration, and a second “crossing over”, which effects excision in the csp1 gene, the Δcsp1 deletion is incorporated and a complete loss of function is achieved in the particular strain.
[0027] Instructions and explanations relating to integration mutagenesis may be found, for example, in Schwarzer and Pühler (Bio/Technology 9,84-87 (1991)) I.B.R. or Peters-Wendisch et al. (Applied Microbiology 144, 915-927 (1998)) I.B.R.
[0028] One example of an amino acid producing strain of coryneform bacteria with an attenuated csp1 gene is the lysine producer Corynebacterium glutamicum R167Δcsp1.
[0029] It may additionally be advantageous for the production of L-amino acids, in particular L-lysine, in addition to attenuating the csp1 gene, to amplify one or more enzymes of the particular biosynthetic pathway, of glycolysis, of anaplerotic metabolism, of the citric acid cycle or of amino acid export.
[0030] Thus, for example, for the production of L-lysine
[0031] the dapA gene (EP-B 0 197 335) I.B.R., which codes for dihydropicolinate synthase, may simultaneously be overexpressed, and/or
[0032] the gap gene, which codes for glyceraldehyde 3-phosphate dehydrogenase (Eikmanns (1992), Journal of Bacteriology 174:6076-6086) I.B.R., may simultaneously be overexpressed or
[0033] the pyc gene (Eikmanns (1992), Journal of Bacteriology 174:6076-6086) I.B.R., which codes for pyruvate carboxylase, may simultaneously be overexpressed, or
[0034] the mqo gene (Molenaar et al., European Journal of Biochemistry 254, 395 - 403 (1998)) I.B.R., which codes for malate:quinone oxidoreductase, may simultaneously be overexpressed, or
[0035] the lysE gene (DE-A-195 48 222) I.B.R., which codes for lysine export,
[0036] may simultaneously be overexpressed.
[0037] It may furthermore be advantageous for the production of amino acids, in particular L-lysine, apart from the csp1 gene, simultaneously to attenuate
[0038] the pck gene (DE 199 50 409.1, DSM 13047) I.B.R., which codes for phosphoenolpyruvate carboxykinase, and/or
[0039] the pgi gene (US 09/396,478, DSM 12969) I.B.R., which codes for glucose 6-phosphate isomerase.
[0040] Finally, it may be advantageous for the production of amino acids, in particular L-lysine, in addition to attenuating the csp1 gene, to suppress unwanted secondary reactions (Nakayama: “Breeding of Amino Acid Producing Micro-organisms”, in: Overproduction of Microbial Products, Krumphanzl, Sikyta, Vanek (eds.), Academic Press, London, UK, 1982) I.B.R.
[0041] The culture medium to be used must adequately satisfy the requirements of the particular strains. Culture media for various microorganisms are described in “Manual of Methods for General Bacteriology” from the American Society for Bacteriology (Washington D.C., USA, 1981) I.B.R. Carbon sources which may be used are sugars and carbohydrates, such as glucose, sucrose, lactose, fructose, maltose, molasses, starch and cellulose for example, oils and fats, such as soya oil, sunflower oil, peanut oil and coconut oil for example, fatty acids, such as palmitic acid, stearic acid and linoleic acid for example, alcohols, such as glycerol and ethanol for example, and organic acids, such as acetic acid for example.
[0042] These substances may be used individually or as a mixture. Nitrogen sources which may be used comprise organic compounds containing nitrogen, such as peptone-s, yeast extract, meat extract, malt extract, corn steep liquor, soya flour and urea or inorganic compounds, such as ammonium sulfate, ammonium chloride, ammonium phosphate, ammonium carbonate and ammonium nitrate.
[0043] The nitrogen sources may be used individually or as a mixture. Phosphorus sources which may be used are phosphoric acid, potassium dihydrogen phosphate or dipotassium hydrogen phosphate or the corresponding salts containing sodium.
[0044] The culture medium may additionally contain salts of metals, such as magnesium sulfate or iron sulfate for example, which are necessary for growth. Finally, essential growth-promoting substances such as amino acids and vitamins may also be used in addition to the above-stated substances. Suitable precursors may furthermore be added to the culture medium. The stated feed substances may be added to the culture as a single batch or be fed appropriately during culturing.
[0045] Basic compounds, such as sodium hydroxide, potassium hydroxide, ammonia or ammonia water, or acidic compounds, such as phosphoric acid or sulfuric acid, are used appropriately to control the pH of the culture. Foaming may be controlled by using antifoaming agents such as fatty acid polyglycol esters for example.
[0046] Plasmid stability may be maintained by the addition to the medium of suitable selectively acting substances, for example antibiotics. Oxygen or oxygen-containing gas mixtures, such as air for example, are introduced into the culture in order to maintain aerobic conditions. The temperature of the culture is normally from 20° C. to 45° C. and preferably from 25° C. to 40° C. The culture is continued until a maximum quantity of the desired product has been formed. This aim is normally achieved within 10 to 160 hours.
[0047] Methods for determining L-amino acids are known from the prior art. Analysis may proceed by anion exchange chromatography with subsequent ninhydrin derivatisation, as described in Spackman et al. (Analytical Chemistry, 30, (1958), 1190) I.B.R.or by reversed phase HPLC, as described in Lindroth et al. (Analytical Chemistry (1979) 51: 1167-1174) I.B.R.
[0048] The following microorganism has been deposited with Deutsche Sammlung fur Mikroorganismen und Zelikulturen (DSMZ, Braunschweig, Germany) in accordance with the Budapest Treaty:
[0049] Escherichia coli strain S17-1 /pKl8mobsacBΔcsp1 as DSM 13048
EXAMPLES
[0050] The present invention is illustrated in greater detail by the following practical examples.
Example 1
[0051] Production of a deletion vector for deletion mutagenesis of the csp1 gene
[0052] Chromosomal DNA was isolated from strain ATCC 13032 using the method of Eikmanns et al. (Microbiology 140: 1817-1828 (1994)) I.B.R. The nucleotide sequence of the csp1 gene for C. glutamicum is available under the accession number g404 86 from the nucleotide sequence database of the National Center for Biotechnology Information (NCBI, Bethesda, Md., USA) I.B.R. On the basis of the known sequence the following oligonucleotides were selected for the polymerase chain reaction:
csp1-10: 5′ CAT CTA G(GA TC)C CGA TGA GCG CCT CCA TGT GT 3′ csp1-11: 5′ GAT CTA G(GA TC)C TCG ACC TTG CGG TGC TGC TT 3′ osp1-del: 5′ GGA ATA CGT AGC CAC CTT CGG TCC CGA AAG TTC CCC CCT T 3′
[0053] The stated primers were synthesised by the company MWG Biotech (Ebersberg, Germany) and the PCR reaction performed in accordance with the standard PCR method of Karreman (BioTechniques 24:736-742, 1998) I.B.R. using Pwo polymerase from Boehringer. The primers csp1-10 and csp1-11 each contain an inserted restriction site for the restriction enzyme BamHI, this site being shown in brackets above. A DNA fragment of approx. 0.9 kb in size, which bears a 1690 bp deletion of the csp1 gene, was isolated with the assistance of the polymerase chain reaction.
[0054] The amplified DNA fragment was cut with the restriction enzyme BamHI and purified on an agarose gel (0.8%). The plasmid pKl8mobsacB (Jager et al., Journal of Bacteriology, 1:784-791 (1992)) I.B.R. was also cut with the restriction enzyme BamHI. The plasmid pKl8mobsacB and the PCR fragment were ligated. The E. coli strain S17-1 (Simon et al., 1993, Bio/Technology 1:784-791) I.B.R. was then electroporated with the ligation batch (Hanahan, in DNA cloning. A practical approach. Vol.I. IRL-Press, Oxford, Washington D.C., USA, 1985) I.B.R. Plasmid-bearing cells were selected by plating the transformation batch out onto LB agar (Sambrook et al., Molecular cloning: a laboratory manual. 2 nd Ed. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 1989) I.B.R. which had been supplemented with 25 mg/l of kanamycin.
[0055] Plasmid DNA was isolated from a transformant using the QIAprep Spin Miniprep Kit from Qiagen and verified by restriction with the restriction enzyme BamHI and subsequent agarose gel electrophoresis (0.8%). The plasmid was named pKl8mobsacBΔcsp1. The strain was designated E. coli S17-1 /pKl8mobsacBΔcsp1and is deposited with Deutsche Sammlung für Mikroorganismen und Zellkulturen (DSMZ, Braunschweig, Germany) under number DSM 13048.
Example 2
[0056] Deletion mutagenesis of csp1 gene into C. glutamicum wild type R167
[0057] The vector named pKl8mobsacBΔcsp1 in Example 2 was electroporated into Corynebacterium glutamicum R167 (Liebl et al. (1989) I.B.R. FEMS Microbiological Letters 65:299-304) using the electroporation method of Tauch et al. (FEMS Microbiological Letters, 123:343-347 (1994)) I.B.R. Strain R167 is a restriction-deficient C. glutamicum wild type strain. The vector pKl8mobsacBΔcsp1 cannot independently replicate in C. glutamicum and is only retained in the cell if it has been integrated into the chromosome. Clones with pKl8mobsacBΔcsp1 integrated into the chromosome were selected by plating the electroporation batch out onto LB agar (Sambrook et al., Molecular cloning: a laboratory manual. 2 nd Ed. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 1989) I.B.R. which had been supplemented with 15 mg/l of kanamycin. Clones which had grown were plated out onto LB agar with 25 mg/l of kanamycin and incubated for 16 hours at 33° C. In order to achieve excision of the plasmid together with the complete chromosomal copy of the csp1 gene, the clones were then cultured on LB agar with 10% sucrose.
[0058] Plasmid pKl8mobsacB contains a copy of the sacB gene, which converts sucrose into levansucrase, which is toxic to C. glutamicum. Thus, the only clones to grow on LB agar with sucrose are those in which the integrated pKl8mobsacBΔcsp1 has in turn been excised.
[0059] Excision of the plasmid may be accompanied by the excision of either the complete chromosomal copy of the csp1 gene or the incomplete copy with the internal-deletion. In order to prove that the incomplete copy of csp1 remains in the chromosome, the plasmid pKl8mobsacBΔcsp1 fragment was labelled with the Dig hybridisation kit from Boehringer using the method according to “The DIG System Users Guide for Filter Hybridization” from Boehringer Mannheim GmbH (Mannheim, Germany, 1993) I.B.R.
[0060] Chromosomal DNA of a potential deletion mutant was isolated using the method according to Eikmanns et al. (Microbiology 140: 1817-1828 (1994)) I.B.R. and cut in each case with the restriction enzyme EcoRI. The resultant fragments were separated by agarose gel electrophoresis and hybridised at 68° C. using the Dig hybridisation kit from Boehringer. Two hybridising fragments of approx. 6500 bp and approx. 4000 bp were obtained from the control strain, while two hybridising fragments of approx. 6500 bp and approx. 3200 bp were obtained from the mutant.
[0061] It could thus be shown that strain R167 has lost its complete copy of the csp1 gene and, instead, now only has the incomplete copy with the deletion of approx. 1690 bp. The strain was designated C. glutamicum R167Δcsp1.
Example 3
[0062] Production of Lysine
[0063] The C. glutamicum strain DSM167Δcsp1 obtained in Example 2 was cultured in a nutrient medium suitable for the production of lysine and the lysine content of the culture supernatant was determined.
[0064] To this end, the strain was initially incubated for 33 hours at 33° C. on an agar plate. Starting from this agar plate culture, a preculture was inoculated (10 ml of medium in a 100 ml Erlenmeyer flask). The complete medium CgIII was used as the medium for this preculture. The preculture was incubated for 48 hours at 33° C. on a shaker at 240 rpm. A main culture was inoculated from this preculture, such that the initial OD (660 nm) of the main culture was 0.1 OD. Medium MM was used for the main culture.
Medium MM CSL (Corn Steep Liquor) 5 g/l MOPS 20 g/l Glucose (separately autoclaved) 50 g/l Salts: (NH 4 ) 2 SO 4 ) 25 g/l KH 2 PO 4 0.1 g/l MgSO 4 * 7 H 2 O 1.0 g/l CaCl 2 * 2 H 2 O 10 mg/l FeSO 4 * 7 H 2 O 10 mg/l MnSO 4 * H 2 O 5.0 mg/l Biotin (sterile-filtered) 0.3 mg/l Thiamine * HCl (sterile-filtered) 0.2 mg/l CaCO 3 25 g/l
[0065] CSL, MOPS and the salt solution were adjusted to pH 7 with ammonia water and autoclaved. The sterile substrate and vitamin solutions, together with the dry-autoclaved CaCO 3 , were then added.
[0066] Culturing was performed in a volume of 10 ml in a 100 ml Erlenmeyer flask with flow spoilers. Culturing was performed at 33° C. and 80% atmospheric humidity.
[0067] After 48 hours, the OD was determined at a measurement wavelength of 660 nm using a Biomek 1000 (Beckmann Instruments GmbH, Munich). The quantity of lysine formed was determined using an amino acid analyser from Eppendorf-BioTronik (Hamburg, Germany) by ion exchange chromatography and post-column derivatisation with ninhydrin detection.
[0068] Table 1 shows the result of the test.
TABLE 1 Strain OD (660) Lysine HCl g/l R167 13.8 0.00 R167Δcsp1 12.6 0.99
[0069] The following Figures are attached:
[0070] [0070]FIG. 1: Map of the plasmid pKl8mobsacBΔcsp1.
[0071] The abbreviations and names are defined as follows. The lengths stated should be considered to be approximate.
sacB: sacB gene oriV: replication origin V KmR: Kanamycin resistance BamHI: Restriction site of the restriction enzyme BamHI csp1′: incomplete fragment of the csp1 gene with an internal 1690 bp deletion
[0072] Further variations and modifications of the present invention will be apparent to those skilled in the art from a reading of the foregoing and are encompassed by the claims appended hereto.
[0073] German patent application 199 53 809.3 is relied upon and incorporated herein by reference.
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The invention relates to a process for the production of L-amino acids, and in particular L-lysine, in which the following steps are performed,
a) fermentation of the bacteria producing the desired L-amino acid, in which at least the csp1 gene is attenuated,
b) accumulation of the desired product in the medium or in the cells of the bacteria and optionally
c) isolation of the L-amino acid,
Bacteria are optionally used in which a further gene of a biosynthetic pathway of the desired L-amino acid is amplified, or in which a metabolic pathway which reduces formation of the desired L-amino acid is at least partially suppressed.
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[0001] The present invention claims priority from U.S. Provisional Patent Applications No. 60/399,386, filed Jul. 31, 2002, and No. 60/435,541, filed Dec. 20, 2002, the contents of which are herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a system and method of sorting materials using laser steering, and in particular using holographic optical trapping.
[0003] In United States industry, there is a large number of unmet sorting and separation needs involving material made up of particles or units smaller than 50 microns. These needs range across industries from particle sizing and sample preparation in the specialty chemicals and materials fields including manufacturing products of nanotechnology, to protein selection and purification in the pharmaceutical and biotechnology industries. Other examples include cell sorting and selection, in the medical, diagnostic and agriculture sectors.
[0004] The importance of these needs can be seen by exploring the annual expenditures in areas where specialized or partial solutions have been developed, as well as by estimating the market value of sorted/separated/purified output in areas where there is currently not even a partial solution. As an example of the former, the biotechnology and pharmaceutical industries annually spend a huge amount on equipment and supplies for protein purification.
[0005] As an example of the latter, in the agricultural sector, there is currently no way to efficiently select the gender of offspring in farm animals; however, it is estimated that in the cattle area alone, value would be added by enabling such sperm selection as a part of the current artificial insemination process widely used in the industry.
[0006] Outside of the animal husbandry market, the purification process of islet cells from human pancreases is currently a large concern of medical scientists developing new treatment methods for Type I diabetes. Significant progress in islet transplantation methods has been made, but the purification problem is one of the remaining stumbling blocks. Traditional methods for purifying islet cells are inefficient and result in damage to the cells.
[0007] Islet cell transplantation is important because, in the Type I form of diabetes, the existing islet cells in the patient's pancreas have become damaged and no longer produce the insulin which is required for human survival. The current treatment for Type I diabetes involves injection of insulin 1 to 5 times per day. In spite of the treatment, the disease often leads to complications including blindness, blood flow problems requiring amputation, renal failure, and death. Greater purity and reduced contaminants for islet cells used in transplantation is expected to reduce the occurrence of these complications.
[0008] Of the approximately 1 million current sufferers of Type I diabetes in the United States, at least 50,000 sufferers per year would submit to islet cell transplantation if it were available. Upon large-scale acceptance of islet cell transplantation as an effective therapy, costs would be expected to jump substantially. The jump would be driven by the difficulty of using today's treatment method (frequent injections) and the severe consequences even when the current treatment is adequately administered.
[0009] Thus, islet purification is but one important problem requiring the highly selective sorting of human cells in a non-damaging, non-invasive way.
[0010] Another problem that needs to be addressed is the purification of normal cells from cancer cells in the bone marrow of persons undergoing whole-body radiation treatment for cancer.
[0011] Still another is the selection of stem cells for research into the causes of, and therapies for, diseases such as Parkinson's disease.
[0012] Yet another concern is developing new ways to automatically interrogate large numbers of human cells and select ones having characteristics not amenable to fluorescent tagging, which would enormously widen the scope and power of medical diagnoses.
[0013] One conventional technique in manipulating microscopic objects is optical trapping. An accepted description of the effect of optical trapping is that tightly focused light, such as light focused by a high numerical aperture microscope lens, has a steep intensity gradient. Optical traps use the gradient forces of a beam of light to trap a particle based on its dielectric constant. “Particle” refers to a biological or other chemical material including, but not limited to, oligonucleotides, polynucleotides, chemical compounds, proteins, lipids, polysaccharides, ligands, cells, antibodies, antigens, cellular organelles, lipids, blastomeres, aggregations of cells, microorganisms, peptides, cDNA, RNA and the like.
[0014] To minimize its energy, a particle having a dielectric constant higher than the surrounding medium will move to the region of an optical trap where the electric field is the highest. Particles with at least a slight dielectric constant differential with their surroundings are sensitive to this gradient and are either attracted to or repelled from the point of highest light intensity, that is, to or from the light beam's focal point. In constructing an optical trap, optical gradient forces from a single beam of light are employed to manipulate the position of a dielectric particle immersed in a fluid medium with a refractive index smaller than that of the particle, but reflecting, absorbing and low dielectric constant particles may also be manipulated.
[0015] The optical gradient force in an optical trap competes with radiation pressure which tends to displace the trapped particle along the beam axis. An optical trap may be placed anywhere within the focal volume of an objective lens by appropriately selecting the input beam's propagation direction and degree of collimation. A collimated beam entering the back aperture of an objective lens comes to a focus in the center of the lens' focal plane while another beam entering at an angle comes to a focus off-center. A slightly diverging beam focuses downstream of the focal plane while a converging beam focuses upstream. Multiple beams entering the input pupil of the lens simultaneously each form an optical trap in the focal volume at a location determined by its angle of incidence. The holographic optical trapping technique uses a phase modifying diffractive optical element to impose the phase pattern for multiple beams onto the wavefront of a single input beam, thereby transforming the single beam into multiple traps.
[0016] Phase modulation of an input beam is preferred for creating optical traps because trapping relies on the intensities of beams and not on their relative phases. Amplitude modulations may divert light away from traps and diminish their effectiveness.
[0017] When a particle is optically trapped, optical gradient forces exerted by the trap exceed other radiation pressures arising from scattering and absorption. For a Gaussian TEM 00 input laser beam, this generally means that the beam diameter should substantially coincide with the diameter of the entrance pupil. A preferred minimum numerical aperture to form a trap is about 0.9 to about 1.0.
[0018] One difficulty in implementing optical trapping technology is that each trap to be generated generally requires its own focused beam of light. Many systems of interest require multiple optical traps, and several methods have been developed to achieve multiple trap configurations. One existing method uses a single light beam that is redirected between multiple trap locations to “time-share” the beam between various traps. However, as the number of traps increases, the intervals during which each trap is in its “off” state may become long for particles to diffuse away from the trap location before the trap is re-energized. All these concerns have limited implementations of this method to less than about 10 traps per system.
[0019] Another traditional method of creating multi-trap systems relies on simultaneously passing multiple beams of light through a single high numerical aperture lens. This is done by either using multiple lasers or by using one or more beam splitters in the beam of a single laser. One problem with this technique is that, as the number of traps increases, the optical system becomes progressively more and more complex. Because of these problems, the known implementations of this method are limited to less than about 5 traps per system.
[0020] In a third approach for achieving a multi-trap system, a diffractive optical element (DOE) (e.g., a phase shifting hologram utilizing either a transmission or a reflection geometry) is used to alter a single laser beam's wavefront. This invention is disclosed in U.S. Pat. No. 6,055,106 to Grier et al. The wavefront is altered so that the downstream laser beam essentially becomes a large number of individual laser beams with relative positions and directions of travel fixed by the exact nature of the diffractive optical element. In effect, the Fourier transform of the DOE produces a set of intensity peaks each of which act as an individual trap or “tweezer.”
[0021] Some implementations of the third approach have used a fixed transmission hologram to create between 16 and 400 individual trapping centers.
[0022] A fixed hologram has been used to demonstrate the principle of holographic optical trapping but using a liquid crystal grating as the hologram permitted ‘manufacture’ of a separate hologram for each new distribution of traps. The spatially varying phase modulation imposed on the trapping laser by the liquid crystal grating may be easily controlled in real time by a computer, thus permitting a variety of dynamic manipulations.
[0023] Other types of traps that may be used to optically trap particles include, but are not limited to, optical vortices, optical bottles, optical rotators and light cages. An optical vortex produces a gradient surrounding an area of zero electric field which is useful to manipulate particles with dielectric constants lower than the surrounding medium or which are reflective, or other types of particles which are repelled by an optical trap. To minimize its energy, such a particle will move to the region where the electric field is the lowest, namely the zero electric field area at the focal point of an appropriately shaped laser beam. The optical vortex provides an area of zero electric field much like the hole in a doughnut (toroid). The optical gradient is radial with the highest electric field at the circumference of the doughnut. The optical vortex detains a small particle within the hole of the doughnut. The detention is accomplished by slipping the vortex over the small particle along the line of zero electric field.
[0024] The optical bottle differs from an optical vortex in that it has a zero electric field only at the focus and a non-zero electric field in all other directions surrounding the focus, at an end of the vortex. An optical bottle may be useful in trapping atoms and nanoclusters which may be too small or too absorptive to trap with an optical vortex or optical tweezers. (See J. Arlt and M. J. Padgett. “Generation of a beam with a dark focus surrounded by regions of higher intensity: The optical bottle beam,” Opt. Lett. 25, 191-193, 2000.)
[0025] The light cage (U.S. Pat. No. 5,939,716) is loosely, a macroscopic cousin of the optical vortex. A light cage forms a time-averaged ring of optical traps to surround a particle too large or reflective to be trapped with dielectric constants lower than the surrounding medium.
[0026] When the laser beam is directed through or reflected from the phase patterning optical element, the phase patterning optical element produces a plurality of beamlets having an altered phase profile. Depending on the number and type of optical traps desired, the alteration may include diffraction, wavefront shaping, phase shifting, steering, diverging and converging. Based upon the phase profile chosen, the phase patterning optical element may be used to generate optical traps in the form of optical traps, optical vortices, optical bottles, optical rotators, light cages, and combinations of two or more of these forms.
[0027] With respect to the manipulation of materials, tweezing of viruses and bacteria has been demonstrated in addition to tweezing of dielectric spheres. In addition to prokaryotes and viruses, a large variety of protists such as Tetrahymena thermophila has been successfully tweezed. Furthermore, both somatic cells such as eukocytes and epithelial cheek cells, and germ line cells such as spermatozoa have been trapped and manipulated.
[0028] Researchers have sought indirect methods for manipulating cells, such as tagging the cells with diamond micro-particles and then tweezing the diamond particles. Cell manipulations have included cell orientation for microscopic analysis as well as stretching cells. Tissue cells have also been arranged with tweezers in vitro in the same spatial distribution as in vivo.
[0029] In addition to the cells themselves, optical tweezers have been used to manipulate cellular organelles, such as vesicles transported along microtubules, chromosomes, or globular DNA. Objects have also been inserted into cells using optical tweezers.
[0030] A variety of sorting processes for biological purposes is also possible with optical tweezers. Cell sorting using traditional optical trapping for assays and chromosome collection and sorting to create libraries have already been demonstrated. Cell assays for drug screening have also been developed.
[0031] Accordingly, as an example of new types of sorting using laser steered optical traps, a method of cell sorting using a technique which isolates valuable cells from other cells, tissues, and contaminants is needed. Further, a way of achieving a unique contribution of optical trapping to the major industrial needs of (cell) sorting and purification is required. Still further, there is a need to separate sperm cells in the animal husbandry market.
SUMMARY OF THE INVENTION
[0032] The present invention relates to a system and method of sorting materials using laser steering, and in particular using holographic optical trapping.
[0033] In one embodiment consistent with the present invention, optical trapping, which is a technology which has been used as a tool for manipulating microscopic objects, is used. An accepted description of the effect is that tightly focused light, such as light focused by a high numerical aperture microscope lens, has a steep intensity gradient. Optical traps use the gradient forces of a beam of light to trap a particles based on its dielectric constant To minimize its energy, a particle having a dielectric constant higher than the surrounding medium will move to the region of an optical trap where the electric field is the highest.
[0034] Optical trapping of the present invention is used to address cell sorting and purification in several ways. For example, the forces exerted by optical traps on a material are sensitive to the exact distribution of the dielectric constant in that material—the optical force therefore depends on the composition and shape of the object.
[0035] Further, other forces on the object are sensitive to the hydrodynamic interaction between the object and the surrounding fluid—control of the fluid flow probes material shape, size and such features as surface rugosity.
[0036] Still further, localizing an object at a known position allows additional methods of automated interrogation such as high speed imaging and particle-specific scattering measurements.
[0037] In one embodiment consistent with the present invention, in achieving a multi-trap system, a diffractive optical element (DOE, i.e., a phase shifting hologram utilizing either a transmission or a reflection geometry) is used to alter a single laser beam's wavefront. The wavefront is altered so that the downstream laser beam essentially becomes a large number of individual laser beams with relative positions and directions of travel fixed by the exact nature of the diffractive optical element.
[0038] The present invention provides optical trapping by focusing a laser beam with a lens to create an optical trap wherein the lens has a numerical aperture less than 0.9, and preferably decreases until it is most preferably less than 0.1.
[0039] Sorting using holographic laser steering involves establishing classes of identification for objects to be sorted, introducing an object to be sorted into a sorting area, and manipulating the object with a steered laser according to its identity class. The manipulation may be holding, moving, rotating, tagging or damaging the object in a way which differs based upon its identity class. Thus, the present invention provides a way of implementing a parallel approach to cell sorting using holographic optical trapping.
[0040] In one embodiment of the present invention, spectroscopy of a sample of biological material may be accomplished with an imaging illumination source suitable for either inelastic spectroscopy or polarized light back scattering, the former being useful for assessing chemical identity, and the latter being suited for measuring dimensions of internal structures such as the nucleus size. Using such spectroscopic methods, in some embodiments, cells are interrogated. The spectrum of those cells which had positive results (i.e., those cells which reacted with or bonded with a label) may be obtained by using this imaging illumination.
[0041] A computer program may analyze the spectral data to identify the desired targets (i.e., cells bearing either an X or Y chromosome, or a suspected cancerous, pre-cancerous and/or non-cancerous cell types, etc.), then may apply the information to direct the phase patterning optical element (i.e., optical traps) to segregate or contain those desired or selected targets (i.e., cell types). The contained cells may be identified based on the reaction or binding of the contained cells with chemicals, or by using the natural fluorescence of the object, or the fluorescence of a substance associated with the object, as an identity tag or background tag. Upon completion of the assay, selection may be made, via computer and/or operator, of which cells to discard and which to collect.
[0042] Manipulation of cells in general, is made safer by having multiple beams available. Like a bed of nails, multiple tweezers ensure that less power is introduced at any particular spot in the cell. This eliminates hot spots and reduces the risk of damage. Any destructive two-photon processes benefit greatly since the absorption is proportional to the square of the laser power. Just adding a second tweezer decreases two-photon absorption in a particular spot by a factor of four. Large cells like Tetrahymena involves a large amount of laser power for effective trapping. Putting the power into a single trap may cause immediate damage to the cell.
[0043] The manipulation of even just a single cell is greatly enhanced by utilizing holographic optical trapping, for example. A single epithelial cheek cell may be manipulated by a line of tweezers, which lift the cell along the perimeter on one side. The resulting rotation allows a 360 degree view of the cell. In addition to the advantage for viewing of biological samples, there also exists the ability to orient samples stably, which has clear benefit for studies such as scattering experiments which have a strong dependence on orientation of the sample.
[0044] Sorting with a wide field of view has many advantages such as higher throughput. However, standard tweezing in a WFOV may fails du to excessive radiation pressure. Tweezing with a wide field of view using holographic optical trapping may permit the ability to form exotic modes of light which greatly reduce the radiation pressure of the light beam. Vortex traps, for example, have a dark center because the varying phases of light cancel in the center of the trap. This dark center means most of the rays of light which travel down the center of the beam no longer exist. It is exactly these beams which harbor most of the radiation pressure of the light, so their removal greatly mitigates the difficulty in axial trapping. Other modes, e.g., donut modes, have the same advantage.
[0045] In one embodiment consistent with the present invention, the method and system lends itself to a semi-automated or automated process for tracking the movement and contents of each optical trap. In one embodiment consistent with the present invention, movement may be monitored via an optical data stream which can be viewed, or converted to a video signal, monitored, or analyzed by visual inspection of an operator, spectroscopically, and/or by video monitoring. The optical data stream may also be processed by a photodectector to monitor intensity, or any suitable device to convert the optical data stream to a digital data stream adapted for use by a computer and program. The computer program controls the selection of cells and the generation of optical traps.
[0046] In other embodiments consistent with the present invention, the movement of cells is tracked based on predetermined movement of each optical trap caused by encoding the phase patterning optical element. Additionally, in some embodiments, a computer program maintains a record of each cell contained in each optical trap.
[0047] In one embodiment consistent with the present invention, cell sorting of X and Y sperm for animal husbandry is performed.
[0048] In the beef cattle industry, the ability to change the male/female ratio of the offspring from the current 50%:50% mix to an 85%:15% mix would dramatically increase the value of the annual offspring. A similar, though smaller, increase in value would occur in the dairy industry.
[0049] In one embodiment consistent with the present invention, a method of sorting objects includes the steps of introducing the objects into an input channel at a predetermined flow rate; funneling the objects using a beam steering apparatus; evaluating the objects to determine which meet a predetermined criteria; and sorting the objects which meet said criteria from objects which do not meet said criteria.
[0050] In another embodiment consistent with the present invention, a method of sorting objects includes the steps of distributing the objects over a surface of a structure; and evaluating the objects in said structure according to a predetermined criteria using a beam steering apparatus.
[0051] In yet another embodiment consistent with the present invention, a method of sorting objects includes the steps of distributing the objects in a gel; detecting the objects which meet a predetermined criteria; and sorting the objects which meet said criteria from objects which do not meet said criteria.
[0052] In yet another embodiment consistent with the present invention, an apparatus for sorting objects includes a plurality of optical traps formed using an optical trapping apparatus; an input channel into which the objects are introduced at a predetermined flow rate; and at least one output channel; wherein the objects are sorted according to predetermined criteria using said optical traps in a sorting region prior to entering said output channel.
[0053] In yet another embodiment consistent with the present invention, an apparatus for sorting objects includes a beam steering apparatus; and a structure having a surface on which the objects are distributed; wherein the objects are sorted using said bean steering apparatus, according to whether the objects meet predetermined criteria.
[0054] In yet another embodiment consistent with the present invention, an apparatus for sorting objects includes means for introducing the objects into an input channel at a predetermined flow rate; means for funneling the objects; means for evaluating the objects to determine which objects meet predetermined criteria; and means for sorting the objects which meet said criteria from objects which do not meet said criteria.
[0055] In yet another embodiment consistent with the present invention, an apparatus for sorting objects includes means for distributing the objects over a surface of a structure; and means for evaluating the objects in said structure according to predetermined criteria using a beam steering apparatus.
[0056] In yet another embodiment consistent with the present invention, an apparatus for sorting objects includes means for distributing the objects in a gel; means for detecting the objects which meet a predetermined criteria; and means for sorting the objects which meet said criteria from objects which do not meet said criteria.
[0057] In yet another embodiment consistent with the present invention, a method of sorting objects includes the steps of accessing an object using an optical trap; examining said object to determine its identity; and sorting said identified object according to predetermined criteria.
[0058] In yet another embodiment consistent with the present invention, an apparatus for sorting objects includes means for accessing an object using an optical trap; means for examining said object to determine its identity; and means for sorting said identified object according to predetermined criteria.
[0059] In yet another embodiment consistent with the present invention, an apparatus for sorting objects includes a beam steering apparatus including: a laser which provides a laser beam for illumination; a diffractive optical element which diffracts said beam into a plurality of beamlets; and an objective lens which converges the beamlet, thereby producing optical gradient conditions resulting in an optical data stream to form an optical trap; and a sample chamber into which the objects are introduced, trapped and sorted.
[0060] In yet another embodiment consistent with the present invention, a method of manipulating objects includes introducing the objects into an evaluation system; evaluating the objects according to a predetermined criteria using a beam steering apparatus; and manipulating the objects according to said predetermined criteria using said beam steering apparatus.
[0061] In yet another embodiment consistent with the present invention, a method of destroying objects includes accessing an object using a beam steering apparatus; examining said object to determine its identity; sorting said identified object according to predetermined criteria; and destroying said identified object when said object meets said predetermined criteria.
[0062] Finally, in yet another embodiment consistent with the present invention, an apparatus for destroying objects includes means for accessing an object using a beam steering apparatus; means for examining said object to determine its identity; means for sorting said identified object according to predetermined criteria; and means for destroying said identified object when said object meets said predetermined criteria.
[0063] There has thus been outlined, rather broadly, some features consistent with the present invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features consistent with the present invention that will be described below and which will form the subject matter of the claims appended hereto.
[0064] In this respect, before explaining at least one embodiment consistent with the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. Methods and apparatuses consistent with the present invention are capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract included below, are for the purpose of description and should not be regarded as limiting.
[0065] As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the methods and apparatuses consistent with the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0066] [0066]FIG. 1 schematically illustrates a holographic optical trapping system according to one embodiment consistent with the present invention.
[0067] [0067]FIGS. 2A and 2B are a side view schematic diagram and a top view schematic diagram, respectively, showing a sample being introduced into sample holder, according to one embodiment consistent with the present invention.
[0068] [0068]FIG. 3 depicts a scanning electron micrograph of a sample chamber according to one embodiment consistent with the present invention.
[0069] [0069]FIG. 4 shows an enlarged view of the working area of a sample chamber according to one embodiment consistent with the present invention.
[0070] [0070]FIG. 5 is a schematic diagram of a holographic optical trapping system for sorting objects according to one embodiment consistent with the present invention.
[0071] [0071]FIG. 6 illustrates an example of lateral deflection for sorting according to one embodiment consistent with the present invention.
[0072] [0072]FIGS. 7A and 7B illustrate schematic front and side views, respectively, of the funneling traps according to one embodiment consistent with the present invention.
[0073] [0073]FIG. 8 illustrates a spinning disc-based cell sorted according to one embodiment consistent with the present invention.
[0074] [0074]FIG. 9 illustrates optical peristalsis according to one embodiment consistent with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0075] In a holographic optical trapping apparatus or system 100 as illustrated in FIG. 1, light is incident from a laser system, and enters as shown by the downward arrow, to power the system 100 .
[0076] A phase patterning optical element 101 is preferably a dynamic optical element (DOE), with a dynamic surface, which is also a phase-only spatial light modulator (SLM) such as the “PAL-SLM series X7665,” manufactured by Hamamatsu of Japan, the “SLM 512SA7” or the “SLM 512SA15” both manufactured by Boulder Nonlinear Systems of Lafayette, Colo. These dynamic phase patterned optical elements 101 are computer-controlled to generate the beamlets by a hologram encoded in the medium which may be varied to generate the beamlets and select the form of the beamlets. A phase pattern 1 - 2 generated on the lower left of FIG. 1 produces the traps 103 shown in the lower right filled with 1 μm diameter silica spheres 104 suspended in water 105 . Thus, the system 100 is controlled by the dynamic hologram shown below on the left.
[0077] The laser beam travels through lenses 106 , 107 , to dichroic mirror 108 . The beam splitter 108 is constructed of a dichroic mirror, a photonic band gap mirror, omni directional mirror, or other similar device. The beam splitter 108 selectively reflects the wavelength of light used to form the optical traps 103 and transmits other wavelengths. The portion of light reflected from the area of the beam splitter 108 is then passed through an area of an encoded phase patterning optical element disposed substantially in a plane conjugate to a planar back aperture of a focusing (objective) lens 109 .
[0078] In single beam optical trapping (also called laser or optical tweezers) it had been thought, prior to the present invention, that a high numerical aperture lens was necessary for acceptable optical traps. A basis for this thinking was that, for optical trapping, one uses the gradient in the electric field of the impinging light to trap the particle. In order to have a large trapping force it has been thought necessary to have a large gradient in the electric field (or number density of rays). The way that one usually accomplishes this is to pass the light field through a high numerical aperture lens.
[0079] A concern with observation and trapping of samples within a large field of view is that such observation and trapping would involve an objective lens with a low numerical aperture. Contrary to prior teaching, the present invention provides a low numerical aperture lens as, for example, the objective lens 109 in FIG. 1. The ability to observe and trap in this situation could be useful in any application where one would benefit from a large field of view given by a low magnification lens, such as placing microscopic manufactured parts or working with large numbers of objects, such as cells, for example.
[0080] As an example according to the present invention, 3 micron silica spheres 104 suspended in water 105 were trapped with lenses 109 with an unprecedented low numerical aperture. The lenses 109 used were manufactured by Nikon:
[0081] (a) Plan 4× with an NA of 0.10; and
[0082] (b) Plan 10× with an NA of 0.25.
[0083] Suitable phase patterning optical elements are characterized as transmissive or reflective depending on how they direct the focused beam of light or other source of energy. Transmissive diffractive optical elements transmit the beam of light or other source of energy, while reflective diffractive optical elements reflect the beam.
[0084] The phase patterning optical element 101 may also be categorized as having a static or a dynamic surface. Examples of suitable static phase patterning optical elements include those with one or more fixed surface regions, such as gratings, including diffraction gratings, reflective gratings, and transmissive gratings, holograms, including polychromatic holograms, stencils, light shaping holographic filters, polychromatic holograms, lenses, mirrors, prisms, waveplates and the like. The static, transmissive phase patterning optical element is characterized by a fixed surface.
[0085] However, in some embodiments, the phase patterning optical element 101 itself is movable, thereby allowing for the selection of one more of the fixed surface regions by moving the phase patterning optical element 101 relative to the laser beam to select the appropriate region.
[0086] The static phase patterning optical element may be attached to a spindle and rotated with a controlled electric motor (not shown). The static phase patterning optical element has a fixed surface and discrete regions. In other embodiments of static phase patterning optical elements, either transmissive or reflective, the fixed surface has a non-homogeneous surface containing substantially continuously varying regions, or a combination of discrete regions, and substantially continuously varying regions.
[0087] Examples of suitable dynamic phase patterning optical elements having a time dependent aspect to their function include computer-generated diffractive patterns, phase-shifting materials, liquid crystal phase-shifting arrays, micro-mirror arrays, including piston mode micro-mirror arrays, spatial light modulators, electro-optic deflectors, accousto-optic modulators, deformable mirrors, reflective MEMS arrays and the like. With a dynamic phase patterning optical element 101 , the medium 105 which comprises the phase patterning optical element 101 encodes a hologram which may be altered, to impart a patterned phase shift to the focused beam of light which results in a corresponding change in the phase profile of the focused beam of light, such as diffraction, or convergence. Additionally, the medium 105 may be altered to produce a change in the location of the optical traps 103 . It is an advantage of dynamic phase patterning optical elements 101 , that the medium 105 may be altered to independently move each optical trap 103 .
[0088] In those embodiments in which the phase profile of the beamlets is less intense at the periphery and more intense at regions inward from the periphery, overfilling the back aperture by less than about 15 percent is useful to form optical traps with greater intensity at the periphery, than optical traps formed without overfilling the back aperture.
[0089] In some embodiments, the form of an optical trap may be changed from its original form to that of a point optical trap, an optical vortex, Bessel beam, an optical bottle, an optical rotator or a light cage The optical trap may be moved in two or three dimensions. The phase patterning optical element is also useful to impart a particular topological mode to the laser light, for example, by converting a Gaussian into a Gauss-Laguerre mode. Accordingly, one beamlet may be formed into a Gauss-Laguerre mode while another beamlet may be formed in a Gaussian mode. The utilization of Gauss-Laguerre modes greatly enhances trapping by reducing radiation pressure.
[0090] 1. Imaging System
[0091] The current instrument design uses a high resolution CCD camera for the primary imaging system 110 . The main advantage of the CCD camera (see reference numeral 511 in FIG. 5) is the favorable cost/performance ratio since this technology is a mature one. Another advantage of CCD cameras is their wide dynamic range and the ease of generating digital output.
[0092] The images are viewed on a computer screen (see reference numeral 510 in FIG. 5) to provide both a frame of reference for selecting the location of the traps as well as to minimize the possibility of inadvertent exposure of the operator to the laser.
[0093] 2. User Interface
[0094] a. Object Display
[0095] The user interface consists of a computer screen which displays the field of view acquired by the CCD camera. The user designates the loci of the traps with a mouse. There is also an option to delete a location.
[0096] As described in greater detail below, the user is also able to specify the power per trap so as to be able to avoid specimen damage. In addition it is desirable to be able to vary trap power because trapping depends upon the difference between the index of refraction of the specimen and the suspending medium which can be expected to vary from specimen to specimen.
[0097] b. The Hologram
[0098] The purpose of designating the loci of the traps is to provide input for the hologram calculation. The hologram is essentially a function whose Fourier transform produces the desired trap array. However in the case of the liquid crystal display this function is a phase object (i.e., an object that changes the phase of the wavefront without absorbing any energy
[0099] c. Methods for Choosing the Set of Traps
[0100] When a large number of traps are needed, the time to designate their location with a computer mouse may be inordinately long. Therefore, there are several options to reduce the time required.
[0101] Often one wishes to use the traps to move an object in a particular direction. This may be accomplished by using the mouse to create a line (by dragging). The computer program interprets a line as calling for a series of traps to be deployed sequentially and sufficiently close together so as to move the target in small steps without losing the lock on the target.
[0102] The present invention also includes the capability of changing the height of the traps. If a laser beam is parallel to the optical axis of the objective lens 109 , then a trap forms at the same height as the focal plane of the lens 109 . Changing the height of a trap is accomplished by adjusting the hologram so that the beam of light forming a trap is slightly converging (or diverging) as it enters the objective lens 109 of the microscope. Adjusting the height of a trap is possible using lenses but only a holographic optical trapping (HOT) allows the height of each individual trap to be adjusted independently of any other trap. This is accomplished by the computer program adjusting the phase modulation caused by the liquid crystal hologram.
[0103] 3. Sample Holder
[0104] a. General
[0105] The sample chamber 200 (see FIGS. 2A and 2B) of the present invention is inexpensive and disposable. Although the sample chamber 200 of the present invention is described below, another object of the present invention is to create a flexible design that may be changed for differing applications.
[0106] The sample chamber 200 lies on the surface of a microscope slide 201 . The sample chamber 200 contains a series of channels 203 for introducing specimens or objects. The channels 203 are connected to supply and collection reservoirs by thin tubing 204 (commercially available). Samples or objects will be suspended in a liquid medium and will be introduced into the working area via the channels 203 . The sample chamber 200 is covered by a cover slip 205 .
[0107] b. Manufacture of the Sample Chamber
[0108] In one embodiment consistent with the present invention, a poly(dimethyl siloxane) (PDMS) resin is used to fabricate the chamber 200 . The process involves creating the desired pattern of channels 203 on a computer using standard CAD/CAM methods and transferring the pattern to a photomask using conventional photoresist/etching techniques. The photomask is then used as a negative mask to create an inverse pattern of channels which are etched on a silicon wafer. The depth of the channels 203 is controlled by the etch time. The silicon wafer is a negative replica of the actual sample chamber 200 . The final step consists of creating the positive sample chamber 200 by pouring PDMS onto the wafer and polymerizing. This results in a PDMS mold which is bonded to a glass slide 201 and overlaid with a cover slip 205 . The glass to PDMA bonding is effected with an oxygen etch which activates the exposed surfaces.
[0109] A number of additional steps are necessary to ensure consistent quality. For instance the PDMS solution/hardner is maintained under a vacuum in order to prevent bubble formation. The silicon wafer is silanized to prevent the PDMS from sticking to the wafer. There are a variety of steps involving cleaning the replicas and maintaining proper environmental controls. These represent standard technology.
[0110] The channels 203 are connected to microbore tubing 204 using small syringe needles 206 held using glue 214 , which are inserted through the PDMS mold into small circular wells 207 which connect to each channel 203 . Sample solutions are introduced into the channel 203 using micropumps 208 .
[0111] [0111]FIG. 2B shows a diagram of a typical arrangement for the introduction of a sample via the syringe pump 208 at 210 . The medium is introduced at 211 , and waste is collected at 21 and the desired collections at 213 .
[0112] [0112]FIG. 3 presents a representation of a scanning electron micrograph of the diagram in FIG. 2B as actually created from the process described above. The channels are approximately 50 microns wide and 50 microns deep. FIG. 4 presents a representation of a scanning electron micrograph of the ‘working’ volume where manipulations of the specimen under study would occur. The diagrams clearly show that the channels 203 are smooth and clean. Although the channels 203 are rectangular in cross-section, other shapes may be devised as well. The channels 203 are designed to allow samples to be flowed to a ‘working area’ whose shape may be custom designed for experimental requirements.
[0113] c. Holographic Optical Traps
[0114] Unlike scanned optical traps which address multiple trapping points in sequence, and thus are time-shared, holographic optical traps illuminate each of their traps continuously. For a scanned optical trap to achieve the same trapping force as a continuously illuminated trap, it must provide at least the same time-averaged intensity. This means that the scanned trap has to have a higher peak intensity by a factor proportional to at least the number of trapping regions. This higher peak intensity increases the opportunities for optically-induced damage in the trapped material. This damage may arise from at least three mechanisms: (1) single-photon absorption leading to local heating, (2) single-photon absorption leading to photochemical transformations, and (3) multiple-photon absorption leading to photochemical transformations. Events (1) and (2) may be mitigated by choosing a wavelength of light which is weakly absorbed by the trapping material and by the surrounding fluid medium. Event (3) is a more general problem and is mitigated in part by working with longer-wavelength light. Thus holographic optical traps may manipulate delicate materials more gently with greater effect by distributing smaller amounts of force continuously among a number of points on an object rather than potentially damaging the object by exerting the total force on a single point or at a higher intensity for a period of time.
[0115] In one embodiment consistent with the present invention, the design is flexible in that any desired pattern of channels 203 may be designed with a standard CAD/CAM computer program. The complexity of the pattern is not a factor as long as the channels 203 are far enough apart so as not to impinge on one another. As may be seen in FIGS. 2B and 3, multiple sets of channels 203 may be easily accommodated so that a single chip may be used for more than one experiment. In addition, once a mold is made it may be used to fabricate thousands of sample chambers so the methodology is readily adaptable to mass production techniques. It is estimated that the marginal cost of a single chamber would be of the order of a few cents when in mass production.
[0116] 4. Optical System
[0117] a. Synthesizing the Hologram
[0118] Early versions of the holographic optical traps used fixed holograms fabricated from a variety of materials. These were adequate to demonstrate the principle of using holograms to create up to several hundred traps. However the major shortcoming of these holograms was that they were static and it took hours to make a single hologram. With the advent of the hardware to create computer-driven liquid crystal displays capable of forming holograms many times per second, the use of optical traps as a dynamic device has become a practical reality. The principle for computing the hologram is described below.
[0119] b. The Microscope
[0120] The optical system 110 consists of a standard high quality light microscope. The objective is a high numerical aperture lens 109 coupled with a long working distance condenser lens. The high numerical aperture objective lens 109 is used for trapping. While the long working distance condenser lens may somewhat reduce the resolution in the images, it does not compromise trapping and provides extra space near the sample slide to accommodate plumbing and receptacles. The objects may be moved by holding them with traps and moving the stage of the microscope vertically or laterally.
[0121] In one embodiment consistent with the present invention, approximately 2 mW of laser power is employed to produce 200 microwatts at the trap. The power level available from a 2W laser is adequate to create about 1000 traps. A green laser (532 nm) is used, but other wavelengths may also be used, including, for example, a far red laser to work with materials absorbing near the 532 nm value.
[0122] Trapping depends upon the refractive index gradient so that materials with refractive indices close to that of the surrounding medium need traps with higher power levels. In addition, the tolerance of materials to damage will vary with trap power, so it is desirable for the user to be able to control this parameter. The user may increase the power level in any particular trap using a ‘power slider’ displayed on the graphical interface.
[0123] c. The Liquid Crystal Hologram (Also Referred to as a Spatial Light Modulator or SLM)
[0124] The spatial light modulator 108 is essentially a liquid crystal array controlled by an electrostatic field which, in turn may be controlled by a computer program. The liquid crystal array has the property that it retards the phase of light by differing amounts depending upon the strength of the applied electric field.
[0125] Nematic liquid crystal devices are used for displays or for applications where a large phase-only modulation depth is needed (2π or greater). The nematic liquid crystal molecules usually lie parallel to the surface of the device giving the maximum retardance due to the birefringence of the liquid crystal. When an electric field is applied, the molecules tilt parallel to the electric field. As the voltage is increased the index of refraction along the extraordinary axis, and hence the birefringence, is effectively decreased causing a reduction in the retardance of the device.
[0126] d. The Laser
[0127] Useful lasers include solid state lasers, diode pumped lasers, gas lasers, dye lasers, alexandrite lasers, free electron lasers, VCSEL lasers, diode lasers, Ti-Sapphire lasers, doped YAG lasers, doped YLF lasers, diode pumped YAG lasers, and flash lamp-pumped YAG lasers. Diode-pumped Nd:YAG lasers operating between 10 mW and 5 W are preferred. The preferred wavelengths of the laser beam used to form arrays for investigating biological material include the infrared, near infrared, visible red, green, and visible blue wavelengths, with wavelengths from about 400 nm to about 1060 nm being most preferred.
[0128] 5. Method of Operation
[0129] In one embodiment consistent with the present invention, an optical trapping system 500 (see FIG. 5) (such as the BioRyx system sold by Arryx, Inc., Chicago, Ill.) includes a Nixon TE 2000 series microscope 501 into which a mount for forming the optical traps using a holographic optical trapping unit 505 has been placed. The nosepiece 502 to which is attached a housing, fits directly into the microscope 501 via the mount. For imaging, an illumination source 503 is provided above the objective lens 504 to illuminate the sample 506 .
[0130] In one embodiment of the present invention, the optical trap system 100 (see FIGS. 1 and 5) includes one end of the first light channel which is in close proximity to the optical element, and the other end of the first light channel which intersects with and communicates with a second light channel formed perpendicular thereto. The second light channel is formed within a base of a microscope lens mounting turret or “nosepiece”. The nosepiece is adapted to fit into a Nixon TE 200 series microscope. The second light channel communicates with a third light channel which is also perpendicular to the second light channel. The third light channel traverses from the top surface of the nosepiece through the base of the nosepiece and is parallel to an objective lens focusing lens 109 . The focusing lens 109 has a top and a bottom forming a back aperture. Interposed in the third light channel between the second light channel and the back aperture of the focusing lens is a dichroic mirror beam splitter 108 .
[0131] Other components within the optical trap system for forming the optical traps include a first mirror, which reflects the beamlets emanating from the phase patterning optical element 101 through the first light channel, a first set of transfer optics 106 disposed within the first light channel, aligned to receive the beamlets reflected by the first mirror, a second set of transfer optics 107 disposed within the first light channel, aligned to receive the beamlets passing through the first set of transfer lenses, and a second mirror 108 , positioned at the intersection of the first light channel and the second light channel, aligned to reflect beamlets passing through the second set of transfer optics and through the third light channel.
[0132] To generate the optical traps, a laser beam is directed from a laser 507 (see FIG. 5) through a collimator and through an optical fiber end 508 and reflected off the dynamic surface of the diffractive optical element 509 . The beam of light exiting the collimator end of the optical fiber is diffracted by the dynamic surface of the diffractive optical element into a plurality of beamlets. The number, type and direction of each beamlet may be controlled and varied by altering the hologram encoded in the dynamic surface medium. The beamlets then reflect off the first mirror through the first set of transfer optics down the first light channel through the second set of transfer optics to the second mirror; and are directed at the dichroic mirror 509 up to the back aperture of the objective lens 504 , are converged through the objective lens 504 , thereby producing the optical gradient conditions necessary to form the optical traps. That portion of the light which is split through the dichroic mirror 509 , for imaging, passes through the lower portion of the third light channel forming an optical data stream (see FIG. 1).
[0133] Spectroscopy of a sample of biological material may be accomplished with an imaging illumination source 503 suitable for either spectroscopy or polarized light back scattering, the former being useful for assessing chemical identity, and the later being suited for measuring dimensions of internal structures such as the nucleus size. Using such spectroscopic methods, in some embodiments, cells are interrogated. A computer 510 may be used to analyze the spectral data and to identify cells bearing either an X or Y chromosome, or a suspected cancerous, pre-cancerous and/or non-cancerous cell types. The computer program then may apply the information to direct optical traps to contain selected cell types. The contained cells then may be identified based on the reaction or binding of the contained cells with chemicals.
[0134] The present method and system lends itself to a semi-automated or automated process for tracking the movement and contents of each optical trap. The movement may be monitored, via video camera 511 , spectrum, or an optical data stream and which provides a computer program controlling the selection of cells and generation of optical traps.
[0135] In other embodiments, the movement of cells is tracked based on predetermined movement of each optical trap caused by encoding the phase patterning optical element. Additionally, in some embodiments, a computer program is used to maintain a record of each cell contained in each optical trap.
[0136] The optical data stream may then be viewed, converted to a video signal, monitored, or analyzed by visual inspection of an operator, spectroscopically, and/or video monitoring. The optical data stream may also be processed by a photodetector to monitor intensity, or any suitable device to convert the optical data stream to a digital data stream adapted for use by a computer.
[0137] In an approach which does not employ an SLM, movement is accomplished by transferring the objects from a first set of optical traps to a second, third, and then fourth etc. To move the objects from the first position to a second position, a static phase patterning optical element is rotated around a spindle to align the laser beam with a second region which generates the second set of optical traps at a corresponding second set of predetermined positions. By constructing the second set of optical traps in the appropriate proximity to the first position, the probes may be passed from the first set of optical traps to the second set of optical traps. The sequence may continue passing the probes from the second set of predetermined positions to a third set of predetermined positions, from the third set of positions to a fourth set of predetermined positions, and from the fourth set of predetermined positions and so forth by the rotation of the phase patterning optical element to align the appropriate region corresponding to the desired position. The time interval between the termination of one set of optical traps and the generation of the next is of a duration to ensure that the probes are transferred to the next set of optical traps before they drift away.
[0138] In a staggered movement of the objects from a wide to narrow proximity the staggered movement of the cells occurs in a similar fashion. However, as the objects are passed from a first set of optical traps to a second set and moved to second and subsequent positions, the staggered arrangement of the traps allows the objects to be packed densely without placing a set of traps in too close a proximity to two objects at the same time which could cause the objects to be contained by the wrong optical trap
[0139] Once an object or cell has interacted with a trap, spectral methods may be used to investigate the cell. The spectrum of those cells which had positive results (i.e., those cells which reacted with or bonded with a label) may be obtained by using imaging illumination such as that suitable for either inelastic spectroscopy or polarized light back scattering. A computer may analyze the spectral data to identify the desired targets and direct the phase patterning optical element to segregate those desired targets. Upon completion of the assay, selection may be made, via computer and/or operator, of which cells to discard and which to collect.
[0140] Optical peristalsis (see FIG. 9) is an existing process employing parallel lines of traps 400 in a microfluidic channel 401 arranged so that the spacing between the lines permits particles 402 trapped in one line to be pulled into traps in the other line when the first line of traps is turned off. Optical peristalsis may be used as an alternative to and in conjunction with fluorescent labels (as described later regarding Applications). The process operates by timing the extinction of lines of traps timed so that particles are moved in desired directions specified by the arrangement of the lines of traps. By choosing whether a line of traps on one side or the other of a particle are on or off, the particle may be moved forward or back in a direction. By employing large numbers of traps, large numbers of particles may thus be moved in concert in a given direction. Thus, particles attracted to the traps may be moved to a given area and, if desired, collected there.
[0141] Similarly, by gradually reducing the spacing between traps in lines toward a given direction and/or varying the curvature of the lines of traps, particles may be swept into a focusing pattern to concentrate them. Reversing such a pattern would disperse the particles.
[0142] Spacing between lines of traps may be relatively larger to speed up movement of the particles, or relatively narrower to slow them down. Similarly, varying the intensity of selected traps or lines, and hence their effect on particles, may also be employed. By converging or diverging flows, particles may be combined or separated. In addition, optical peristalsis may be combined with differential effects of viscous drag or electrical fields to produce complex and specific sets of parameter values for finely separating materials, for example. By opposing the trapping and other forces, the balance point of the two forces determines whether a particle moves with the trap or the other force.
[0143] In one embodiment consistent with the present invention, optical peristalsis may be implemented with a holographic system which cycles through a sequence of phase patterns to implement a corresponding sequence of holographic optical trapping patterns. Such patterns may be encoded in the surface relief of reflective diffractive optical elements mounted on the face of a prism, wherein each pattern is rotated into place by a motor. Likewise, transmissive diffractive optical elements may be placed on the perimeter of a disk and rotated to cycle through the patterns. Switchable phase gratings and phase holograms encoded on film may also be used.
[0144] For particles driven past a rectilinear array by an external bias force, such as fluid flow, where the trapping force is considerably greater than the external driving force, the particles are trapped. Where the bias force is greater, the particles flow past the array. Between these extremes, the bias force exceeds the trapping force to a differing degree for different fractions of the particles, causing the particles to hop from trap to trap along the direction of the principal axis of the array. A zero net deflection may be observed where the array is rotated to 45° because: (1) positive and negative displacements occur with equal probability; or (2) the particles become locked into the [11] direction, jumping diagonally through the array.
[0145] Particles affected to a greater degree by an array may be deflected to greater angles than the particles affected to a greater degree by the bias force. The optical gradient force exerted on particles varies roughly as a 3 , where a=radius. Stokes drag on the particles varies as “a”. Thus, larger particles are disproportionately affected by trap arrays, while the smaller particles experience smaller deflection. Orienting the array near the angle of optimal deflection and adjusting the intensity to place the largest particles in the hopping condition, and, hence at greater deflection than smaller particles. Differentially deflected particles may be collected or further fractionated by additional arrays downstream of the first.
[0146] Some conventional techniques for fractionation achieve separation in the direction of an applied force. However, such techniques operate on batches of samples rather than continuously.
[0147] Other conventional techniques for microfractionation employ microfabricated sieves consisting of a two dimensional lattice of obstacles or barriers. For example, an asymmetric placement of barriers rectifies the Brownian motion of particles that pass through the sieve, causing the particles to follow paths that depend on the diffusion coefficients of the particles. However, use of a microfabricated lattices clog and are not tunable for particle size and type.
[0148] In FIG. 6, an example of sorting of particles according to the present invention is exemplified. Although the illustrated example exemplifies lateral deflection, optical peristalsis may be obtained in the same system. A representation of a video image shows light-based separation of material, in this case, tuned to separate objects based on particle size. The flow in the upper left channel contains 1, 2.25, and 4.5 μm particles and another flow enters from the lower left. The superimposed lines respectively indicate each of the channels' flow when the system laser power is off. When the laser power is turned on, light in the interaction region (indicated by the superimposed green box), extracts the 4.5 μm particles from the upper flow and delivers them to the lower-right channel as indicated by the superimposed white path.
[0149] 6. Application in Sperm Sorting
[0150] a. Background
[0151] In one application consistent with the present invention, a high-resolution, high-throughput cell sorter by using optical trapping technology is implemented. The need for implementing this technology as a new basis for cell sorting is evidenced by the failure of traditional flow cytometers to perform the high-resolution determinations of cell characteristics necessary in many sorting problems. In this example of separating X- and Y-chromosome bearing sperm from one another in the cattle industry, flow rates are scaled back substantially from state-of-the-art systems rates of today. The reason is that traditional flow cytometry is best at making a fluorescence/non-fluorescence determination and, in this mode, may operate at rates yielding outputs of 30,000 cells/second. As the problem becomes one of discriminating between different levels of fluorescence (as it is in the sperm separation problem), these methods become highly inefficient. In the sperm separation problem, where the X- and Y-chromosome bearing sperm differ in fluorescence by about 4%, the rate is slowed to about 4,000 output cells per second. (see J. L. Schenk, et al., Proceedings, The Range Beef Cow Symposium XVI, 1999 .)
[0152] b. Sorting Using Holographic Optical Traps
[0153] The method of implementing high-resolution, high-throughput cell sorting of the present invention, has the following components: microfluidic development, optical-trap system development (trapping component for the funnel system and the trap component for the separation system), high-resolution fluorescence measurement, system control (including hologram calculation), and mechanical design.
[0154] The first component is a flow cell that has a fluid input channel, carrying the input sample, and two output channels carrying cells separated out of the input channel. The second component is a set of traps that perform the “funneling” function (this “funneling function” is the equivalent of the nozzle forming the droplet flow in a traditional flow cytometer). The third component is the detection system and, finally, the fourth component is the sorting system. FIGS. 7 A- 7 B illustrate the relationship among these four components.
[0155] In this example, sperm is used as a sample target for separation. The traditional method of differentiating between X- and Y-chromosome bearing sperm employs Hoechst 33342, a dye which binds specifically to DNA in such a way that the total fluorescence present is a measure of the total DNA present. Measurements of this fluorescence yields an estimate of the nature of the underlying chromosome load. (Schenk, 1999; also, Erik B. van Munster, Cytometry, volume 47, page 192, 2002).
[0156] The essential trait allowing this proposed embodiment of the present invention to achieve high throughputs is its inherent capacity to run material in parallel lines simultaneously and in close proximity to one another. For this initial implementation, a flow system with 10 input lines 300 each separated by 10 microns is created. This sets an overall width to the flow from the input reservoir of 110 microns. The output channels 302 , 303 are each the same 110 micron width as the input channel 301 and they run parallel to the input channel 301 as is shown in FIGS. 7A and 7B. Introduced into the “output channels” 302 , 303 is a buffer solution that is fed into these channels at the same flow rate as is maintained in the input channel 301 . All three of these channels 301 , 302 , 303 are designed to maintain laminar flow over the flow ranges of interest. In the sorting region, where specific cells are transferred from the input channel 301 to one of the output channels 302 , 303 , all three flows are adjacent with no mechanical separation between them. The laminar flows keep any material in their respective flows unless a specific external force is introduced to transfer that material from one flow channel to another.
[0157] The funneling traps 305 act on the input cells 306 so they both travel in well defined lines of flow and so the input cells 306 are separated from one another by a minimum distance 306 to be set by the operator. The flow rates in the channels 301 , 302 , 303 are set by this minimum distance 306 , by the “update” rate of the device that is performing the separation function, and by the overall cell processing rate desired. Assuming that minimum distance in our sample case is 20 microns (enough to completely separate the sperm heads, but a distance that will allow an inconsequential overlapping of tails), and a processing rate of 1,500 cells/second, this system uses a flow rate of 3 mm/second [(15,000 cells/second)×(20 microns/cell-line)÷(10 lines)]. (check this)
[0158] The funneling system is composed of a pattern of low intensity traps 305 established by a set of static holograms that are mounted in a rotating wheel so that the pattern changes as a function of the rotation pattern. The most down stream funneling traps are of fixed intensity and position, serving only to maintain the separation between the cells' lines of flow. The upstream traps 305 are allowed to change both intensity and position with time to act so as to disturb the flow on clumped cells and pass through individual, or un-clumped, cells.
[0159] The measurement upon which the sorting determination is made may occur in the downstream region of the funneling traps 305 or it may occur in a region further beyond the funneling system. For this initial system, the measurement will consist of high resolution fluorescence detection. In the future, however, other active sorting criteria may be implemented, such as scattering measurements, or passive techniques may be employed such as those using optical deflection as outlined earlier.
[0160] The final component of the device is the separation system in which the sorting criteria is utilized to divert cells into one of the output channels 302 , 303 or to allow them to remain in the flow of the input channel 301 . The crucial parameter for this component is the field-of-view of the high-numerical-aperture objective lens 304 used to implement the array of dynamic traps 305 driving the separation. The width of this field-of-view is the same 110 microns as the individual channels' widths. The length, however, depends upon the flow rates, the channel depths, and the update rates of the optical device used to control these traps.
[0161] Currently, one embodiment consistent with the present invention includes spatial light modulators that create phase masks which are highly effective in driving optical trapping systems. These devices have update rates of 30 Hz or more. With an estimated channel depth of 10 microns, and assuming that the sperm cells should be moved in 1 micron steps, 10 updates of the spatial light modulator are employed to move a cell from the center of the input channel 301 to the center of either output channel 302 , 303 . With an update value of 30 Hz, the implementation of these 10 steps will occur in ⅓ second. At a flow rate of 3 mm/second, these 10 steps are implemented on a length of 1 mm in the direction of flow. The objective lens 304 for the separation component would therefore have a working area of 110 microns×1000 microns. An important development area of this project is the design of this lens assembly. The trade-off in lens design generally is between field-of-view and numerical aperture. That is, for a lens assembly of a particular complexity, a significant performance increase in one of these areas will come with a decrease in performance in the other area. It is for this reason that the high-performance lenses used in areas such as the high-resolution lithographic production of integrated-circuit electronics are quite complex. The present invention; however, is significantly below the performance levels of these lens assemblies.
[0162] 7. Disclosure on Wide-Field Vortex Tweezing
[0163] Tweezing with a wide field of view involves microscope objective lenses that have a relatively low numerical aperture. The ability to optically trap objects in the axial direction relies on focusing a light beam down in a manner that will have the largest gradients in the axial direction. This implies that a cone of light be formed with the broadest possible radius. The radius of the cone is directly determined by the numerical aperture of the objective, i.e., high numerical aperture means a broad cone radius. This is in direct conflict with the requirements for wide field of view. This has traditionally made tweezing with a wide field of view in the axial direction difficult. One of the major contributions to the difficulty in axial tweezing is the radiation pressure of the focused light beam. Especially for particles that are well matched in density to the surrounding medium, for example polystyrene microspheres, radiation pressure may blow particles out of the trap. With a low numerical aperture objective, it is difficult to overcome the radiation pressure with sufficient tweezing force in the axial direction. However, holographic optical traps have the ability to form exotic modes of light which greatly reduce the radiation pressure of the light beam. Vortex traps, for example, have a dark center because the varying phases of light cancel in the center of the trap. This dark center means most of the rays of light which travel down the center of the beam no longer exist. It is exactly these beams which harbor most of the radiation pressure of the light, so their removal greatly mitigates the difficulty in axial trapping. Other modes, e.g. donut modes, have the same advantage.
[0164] Manipulation (pushing, steering, sorting) of objects or cells in general, is made safer by having multiple beams available. Like a bed of nails, multiple tweezers ensure that less power is introduced at any particular spot in the cell. This eliminates hot spots and reduces the risk of damage. Any destructive two-photon processes benefit greatly since the absorption is proportional to the square of the laser power. Just adding a second tweezer decreases two-photon absorption in a particular spot by a factor of four. Large cells like Tetrahymena, which are held in place by an array of tweezers, involve a large amount of laser power for effective trapping. Putting the power into a single trap would cause immediate damage to the cell.
[0165] Finally, manipulation of even just a single cell is greatly enhanced by utilizing holographic optical trapping. A single epithelial cheek cell can be manipulated by a line of tweezers, which lift the cell along the perimeter on one side. The resulting rotation allows a 360 degree view of the cell. In addition to the advantage for viewing of biological samples, there also exists the ability to orient samples stably, which has clear benefit for studies such as scattering experiments which have a strong dependence on orientation of the sample.
[0166] 8. Spinning Disk-Based Cell Sorter
[0167] Because of the large number of sperm in a typical bovine ejaculate, and the small amount of time available before the sperm becomes no longer functional, a large number of sperm per second (on the order of a million) are sorted for a commercially viable sperm sorter. Sorting with holographic optical traps confers enormous advantage through its ability to process in parallel a large number of cells.
[0168] The technology for using lasers to access a large number of sites quickly already exists in the form of a spinning laser disc, CD player, or DVD player. These devices combine rotational motion of the disc with radial motion of the laser to access sites with incredibly high speeds. For example, the typical DVD player may access approximately 4 billion separate “bits” on the disc in about two hours. Combining this spinning disc approach with optical trapping (see FIG. 8) allows access to cells at similar rates, and holographic optical trapping increases these rates by factors of 100 or even higher.
[0169] As shown in FIG. 8, objects or cells are introduced at the sample intake 700 , and using an appropriate sample delivery system 701 , the cells are provided to the sample distribution disc 702 which is rotated by a motor control. The imaging and trapping system 703 , which is connected to a control and analysis system 704 , sorts the cells and they are collected in sample chambers 705 and 706 .
[0170] There are many mechanisms for distributing the cells over the surface of the disc. Fluid chambers which house individual cells, gels which immobilize the cells, sticky or waxy surfaces which bind the cells, or even freezing the cells into a solid mass, are all methods that may be employed. Once the cells are situated such that they maintain their relative positions, they may be appropriately measured. Optical trapping may then be used to free either the desired or unwanted cells from the surface or volume. In situations where sorting into more than two groups is desired, each group may be released in a single pass, and multiple passes may be executed.
[0171] 9. Sorting of Cells and Non-Biological Material Using Meltable Substrates
[0172] Technologies such as Fluorescence-Activated Cell Sorting (FACS), although well-established, suffer from the fact that they are serial processing methods. Because of the ubiquity of labeling dyes in biology, sorting on the basis of these dyes is possible. These dyes often create a difference in absorption of some wavelength or range of wavelengths between dyed and undyed specimens, assuming that groups that are to be sorted do not already inherently exhibit such an absorption difference. Holographic optical traps may then be used to both heat and manipulate the specimen into a substrate which melts from the raised temperature of the specimen. The specimen which is embedded may then be released later with an increase in the bulk temperature. In addition, a faster, even more parallel processing method is possible in which the cells are illuminated by a broad, high power light source which processes the entire array of specimens simultaneously. The same set of methods may be applied to non-biological samples which differ in the absorption spectra, or may be selectively made to do so.
[0173] 10. Gel-Based Sorting
[0174] Holographic optical laser traps construe a great advantage on the manipulation of objects in that they are able access and move objects in three dimensions. As biological sorting applications become more advanced, larger numbers of specimens need to be sorted, often in small amounts of time. The three-dimensional access of holographic optical traps means that these sorting applications may be realized. Quantities of cells and other specimens of biological interest which would be cumbersome or impossible to sort serially or on a two-dimensional substrate, may be effectively sorted.
[0175] One implementation of such three dimensional sorting relies on a reversible gelation process. The cells are gelled in a network, and then either wanted or unwanted cells are extracted from the gel using holographic optical traps. The heat from the traps may be used to melt the gel and provide exit pathways.
[0176] Alternatively, cells are selectively killed based on some criterion with the holographic optical laser traps. The entire gel is then melted and the live cells are separated from the dead. Instead of just killing, a more destructive thermal explosion may be generated, which disintegrates the cell into much smaller components, and then sorting on the basis of size may be effected, grouping or connecting certain cells together again.
[0177] 11. Killing of Biological Specimens
[0178] A large variety of applications benefit from the ability to selectively kill biological specimens. Removing pathogens from blood is one such application. Cell sorting is another application. Cells are identified, one or more groups of cells are killed, and then the dead cells are removed. The killing is performed by the light energy from the lasers themselves, and do not necessarily require optical traps to perform this function.
[0179] Essentially, the cells are heated or the medium around the cells are heated with the laser beam, damaging and killing the cell. Holographic optical traps, because of their versatility and three-dimensional control, allow selective, massively parallel killing of cells.
[0180] 12. Fixing Electronic Components
[0181] Note that many of the above techniques can be used to move small electronic components or to fix electronic components in place.
[0182] While the invention has been particularly shown with reference to the above embodiments, it will be understood by those skilled in the art that various other changes in the form and details may be made therein without departing from the spirit and the scope of the invention.
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The present invention employs a beam steering apparatus to isolate valuable cells from other cells, tissues, and contaminants. In one embodiment, the system balances optical trapping against biasing flow to parallelize cell sorting under the flexible control of computer program-directed traps which differentially manipulate cells based on their composition or labels to direct separation.
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FIELD OF THE INVENTION
This invention relates to a process for recovering ester and glycol components from condensation-type polyester resins and to apparatus for carrying out that process.
BACKGROUND OF THE INVENTION
Polyester resins have found widespread use in varied applications. Polyesters such as polyethylene terephthalate are used in photographic film, in magnetic tape, in fibers, and in food and beverage containers. Various methods have been disclosed for the depolymerization of such resins into their component monomers, such as ethylene glycol and terephthalic acid or derivatives thereof, so that they can be reused.
Some of these methods are described in such patents as U.S. Pat. Nos. 3,037,050, 3,321,510, 3,884,850, 3,907,868, 4,163,860, 4,578,502, 4,620,032, 4,876,378 and 5,095,145, and in European Published Patent Application 0 484 963 published May 13, 1992.
A particularly useful technique for recovering scrap polyester is described in a series of patent that begins with Naujokas et al. U.S. Pat. No. 5,051,528. This patent describes a process of recovering ethylene glycol and dimethyl terephthalate from polyethylene terephthalate scrap resins by dissolving the polyester resin in oligomers of the same monomers as are present in the polyester, passing super-heated methanol through the solution and recovering ethylene glycol and dimethyl terephthalate.
Gamble et al. U.S. Pat. No. 5,298,530, issued Mar. 29, 1994 improves on the process of the '528 patent by combining scrap resin with reactor melt in a dissolver before the dissolver melt is transferred to the reactor for contact with super-heated methanol. In the reactor, polymers and oligomers are further depolymerized into the component glycol and ester monomers, which are then recovered.
Toot et al. U.S. Pat. No. 5,414,022, issued May 9, 1995, optimizes the conditions of the processes of Naujokas et al. and Gamble et al., cited above.
DeBruin et al U.S. Pat. No. 5,432,203, issued Jul. 11, 1995, extends the processes of prior patents in the series to convert ethylene glycol and dimethyl terephthalate to bishydroxyethyl terephthalate, which then can be used as feedstock for the formation of polyethylene terephthalate.
The processes described in this series of patents and applications have numerous advantages. These include low cost, high efficiency, the ability to operate at relatively low pressure and the ability to be used with a variety of forms of polyester of varying degrees of cleanliness and purity.
The processes and equipment described in this series of patents and applications employ a reactor in which a discontinuous phase of superheated methanol is passed through a continuous phase of molten polyester and polyester decomposition products. While such a reactor is useful, we have found that the conversion rate of polyester to monomer can be improved by the use of a reactor in which the superheated methanol is the continuous phase and molten polyester and polyester decomposition products are the discontinuous phase. We have found that this can be accomplished by using a staged column as the reactor.
SUMMARY OF THE INVENTION
The present invention provides a process for converting polyester to its component monomers. The apparatus used to carry out the process of the present invention is similar to that used for the process described in U.S. Pat. No. 5,298,530. One significant difference is that it employs as the reactor in which the bulk of the conversion takes place a staged column in which methanol vapor is the continuous phase and the molten polyester and polyester decomposition products is the discontinuous phase.
Thus, the present invention is a process for depolymerizing polyester into its components using apparatus that comprises:
a dissolver for receiving polyester and
a staged column reactor for depolymerizing polyester into monomer components and for separating monomer components from higher boiling materials,
the process comprising the steps of:
a) forming a melt of polyester in the dissolver,
b) passing super-heated methanol through the reactor to form a continuous phase of methanol vapor in the reactor,
c) transferring polyester from the dissolver to the reactor to form a discontinuous phase which contacts the methanol vapor to depolymerize the polyester into component monomers which are removed from the reactor by the methanol vapor,
d) removing higher molecular weight materials from the reactor as a liquid phase, and
e) removing methanol and component monomers from the reactor as a vapor phase.
In a preferred embodiment, the polyester added to the dissolver is combined with liquid from the reactor and the two are retained in the dissolver for a period of time sufficient to initiate depolymerization of the polyester and provide reduced chain length polyester.
While a staged column reactor is shown in the polyester recovery process described in Currie et al. U.S. Pat. No. 3,907,868, that reactor is operated in such a way that methanol is the discontinuous phase, as it is in the other recovery processes of which we are aware.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic flow diagram illustrating the inventive process and apparatus utilizing a staged countercurrent reactor.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 schematically illustrates apparatus to carry out a preferred embodiment of the process of the invention.
In the apparatus shown in FIG. 1 a dissolver (10), a reactor (12), a rectifier (14) and a condenser (16) are connected by the pipes, pumps and valves needed to transfer the reactants from one location to another in accordance with the reaction.
Polyethylene terephthalate (20) in a suitable form and size is introduced into the dissolver by any suitable means where it is liquefied and reduced in chain length. The dissolver can be run at atmospheric pressure, or slightly positive or negative pressure, and is equipped with means for heating its contents to a temperature of up to about 305° C. The dissolver preferably is maintained at a temperature in the range of 240° to 260° C.
Reactor melt (22), and optionally rectifier liquid (24), are introduced into the dissolver via means that can be used to control the rate of introduction of these materials and their relative proportions. Reactor melt, and optional rectifier liquid, introduced into the dissolver react with the polyester to shorten the average chain length. This initiates the depolymerization reaction and decreases the viscosity of the dissolver contents. There can be added to the dissolver an ester exchange catalyst, such as zinc acetate. Preferably the catalyst is employed in the range of 30 to 300 ppm polyester, and most preferably the catalyst is employed in the range of 30 to 100 ppm polyester.
There also can be added to the dissolver sufficient base to neutralize any acid formed from contaminants that may be carried into the dissolver with the polyester scrap. If used, sufficient base is added to maintain the pH equivalent of the melt in the range of 7 to 10; preferably 7 to 8.
In a preferred embodiment, the melt in the dissolver is protected from the atmosphere by a blanket of inert gas, such as nitrogen, carbon dioxide, argon, etc. This reduces degradation of the dissolver melt due to oxidation reactions.
The reactor and dissolver melts comprise methanol, low molecular weight polyesters, monomers, monohydric alcohol-ended oligomers, glycols, and dimethylterephthalate and methylhydroxyethyl terephthalate. The major difference between these two melts is the average chain length of the polyester. The rectifier liquid contains the same components except for polyesters.
The viscosity of the dissolver melt preferably is maintained in the range of 0.002 to 0.1 Pa.s. This is sufficiently low to permit the use of inexpensive pumping and heating means, and permits the reactor to be operated at optimum pressures to provide good yields of monomer. The flow rates of material in and out of the dissolver can be adjusted to maintain the viscosity at the desired level.
Low boiling components which evolve in the dissolver may contain monomers that can be recovered together with the monomers exiting the reactor. This can be accomplished by, in separate apparatus, absorbing them into by liquid methanol and recovering them in a separate process.
Melt (26) from the dissolver is transferred to the reactor where it will constitute a discontinuous phase. It typically will be added toward the top of the reactor and will flow toward the bottom of the reactor by gravity. There will be added toward the bottom of the reactor sufficient super heated methanol vapor (28) to fill the column and form a continuous vapor phase in the reactor thorough which the polyester melt descends.
The reactor can comprise packing or trays over which the melt is distributed, thereby increasing the surface area of melt that can come in contact with the methanol vapor. The increased contact area in such reactors facilitates the depolymerization reaction. While a packed column reactor is preferred because of economy of operation, a thin film or wiped film reactor can be employed and still obtain the operational advantages of this invention.
The column is run under conditions that will maintain the methanol vapor as the continuous phase and will have sufficient stages for the depolymerization reaction to be essentially completed in the reactor. Typically it will have from 3 to 20 ideal stages and preferably will have 5 to 8 ideal stages. Conditions for operating the reactor to maintain the methanol vapor as the continuous phase are a temperature in the range of 240° to 300° C. and a pressure from atmospheric to slightly elevated pressure up to about 300 kPaa.
The super-heated methanol vapor can be provided to the reactor by conventional means. Methanol is introduced into the reactor at a rate in the range of 2 to 6 parts by weight methanol per part polyester.
There can transferred from the reactor to a separate rectifier a vapor stream (30) comprising methanol, dimethylterephthalate, glycols including ethylene glycol, diethylene glycol, and triethylene glycol, dimethylisophthalate, cyclohexanedimethanol, and methylhydroxyethyl terephthalate. The rectifier separates higher boiling components, such as methylhydroxyethyl terephthalate, from the vapor stream exiting the reactor and returns it to the reactor in the form of a liquid (32). Part or all of this liquid (24) can be sent to the dissolver to adjust viscosity. While the rectifier is shown as a separate apparatus, it can comprise stages of the depolymerization reactor (12) above the point at which dissolver melt is added.
The vapor stream (36) exiting the rectifier is passed to a reflux condenser where higher boiling components (38) are returned to the reactor and the vapor phase (40) is sent for recovery. The condenser is operated at a temperature in the range of 165° to 210° C. and at atmospheric to slightly elevated pressure, up to about 300 kPaa.
Exiting the condenser is a vapor stream (40) which comprises, methanol, ethylene glycol and dimethyl terephthalate. These components are separated from one another and purified in subsequent operations.
There is removed from the base of the reactor high boiling impurities and reaction by-products (34). Depending on the specific composition of this stream, it can be discarded or sent for recovery of specific components.
At the bottom of the reactor there can optionally be located a reboiler (18) which provides energy to the reactor. Melt (42) can be withdrawn toward the bottom of the column, heated and reintroduced toward the top of the column. Use of such a reboiler to heat the contents of the reactor permits adjusting the operation of the column without being dependent on a minimum amount of melt being introduced from the dissolver.
The invention has been described by reference to preferred embodiments, but it will be understood changes can be made to the apparatus and process steps specifically described herein within the spirit and scope of the invention.
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There is described a process for the depolymerization of polyethylene terephthalate into component monomers using a reactor in which the polyethylene terephthalate is a discontinuous phase which contacts a continuous phase of superheated methanol vapor.
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BACKGROUND OF THE INVENTION
1. Field of the Invention (Technical Field):
The invention relates to presser feet and more particularly to a bifurcated presser foot comprising limbs of predetermined width and spaced indentations for facilitating seam allowance estimations.
2. Description of the Related Art
Presser feet for sewing machines are known to practitioners of the sewing arts. Some presser feet, in addition to performing their primary function of pressing downwardly upon the workpiece to facilitate straight and even stitching, have incorporated supplemental features. For example, U.S. Pat. No. 282,113, to Parkhill, entitled Presser Foot for Sewing Machines; and U. S. Pat. No. 1,147,960, to Mathewson, entitled Presser Foot for Sewing Machines, both generally disclose bearings to reduce frictional contact between presser foot and workpiece.
Other presser feet utilize attachable gauges for aiding in the production of straight and uniform seams and borders. Representations of such attachable gauges are disclosed in U.S. Pat. No. 288,529, to Wellman, entitled Presser Foot and Gage for Sewing Machines; U.S. Pat. No. 413,325, to Littlejohn, entitled Presser Foot and Overlay Guide for Sewing Machines; and U.S. Pat. No. 1,918,643, to Heck, entitled Quilter for Sewing Machines. All of these patents disclose gauges attachable to sewing machine presser feet, ostensibly to facilitate accurate and uniform stitching.
Design as well as utility features have been used. One such design feature is seen in Design Pat. No. 183,390, to Johnson, entitled Sewing Machine Presser-Foot.
Nevertheless, a real need exists in the art for a single article which combines the features of presser foot and gauge. The existing gauge devices are cumbersome and somewhat inefficient. They not only require attachment to the presser foot; they require periodic adjustment.
SUMMARY OF THE INVENTION
In accordance with the present invention there is provided a presser foot for sewing machines. This presser foot comprises a bifurcated foot portion. The bifurcated foot portion comprises: a first limb having a first predetermined width dimension; a second limb having a second predetermined width dimension; a plurality of selectively spaced indentations on at least one of the limbs along its longitudinal dimension; a needle aperture and thread slot disposed between the first limb and the second limb; and means for attaching the bifurcated foot portion to a sewing machine.
In the preferred embodiment, the first predetermined width dimension of the first limb is greater than the second predetermined width dimension of the second limb. For example, the first predetermined dimension of the first limb may be essentially about twice as great as the second predetermined dimension of the second limb. In an embodiment for piecing or doll or toy making applications, the first predetermined dimension of the first limb is essentially about 1/4", and the second predetermined dimension of the second limb is essentially about 1/8".
In the preferred embodiment, each of the limbs comprises a plurality of spaced indentations; these spaced indentations of both the first limb and the second limb are in matching correspondence. The spaced indentations may be disposed on a longitudinal side of the limb(s), on the top surface of the limb(s) or both. The spaced indentations may be regularly spaced such as 1/4" apart. At least one of the spaced indentations should correspond to the center of the needle aperture.
The attachment means for attaching the bifurcated foot portion to the sewing machine comprises an upstanding shank portion adapted to be secured to the sewing machine. The bifurcated foot portion pivots relative to the upstanding shank portion for allowing the foot to move easily over the material being stitched or sewn.
A primary object of the present invention is to provide an improved presser foot especially adapted for piecing and doll and toy making.
Another object of the invention is to provide a presser foot for sewing machines wherein critical seam allowances can be quickly and accurately gauged.
One advantage of the present invention is the combination of presser foot and seam allowance gauge in a single article.
Another advantage of the present invention is the provision of a presser foot having means for conveniently and easily bypassing previous seam allowances.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated into and form a part of the specification, illustrate several embodiments of the present invention and, together with the description, serve to explain the principles of the invention.
FIG. 1 is a perspective view of the preferred embodiment of the invention;
FIG. 2 is a bottom perspective view of the embodiment of FIG. 1;
FIG. 3 is a side view of the embodiment of FIG. 1 showing the movement of the presser foot;
FIG. 4 is a top view of the embodiment of FIG. 1;
FIG. 5 is one side view of the embodiment of FIG. 1;
FIG. 6 is a front view of the embodiment of FIG. 1;
FIG. 7 is another side view of the embodiment of FIG. 1;
FIG. 8 is a rear view of the embodiment of FIG. 1;
FIG. 9 is a bottom view of the embodiment of FIG. 1; and
FIG. 10 is a top view of an alternative embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
OF THE INVENTION (BEST MODES FOR CARRYING OUT THE INVENTION)
Reference is now made to the FIGS. 1-9 which show the preferred presser foot of the invention. As seen therein, the presser foot 10 comprises a bifurcated foot portion 12 comprising a first toe or limb 16 having a first predetermined width dimension and a second toe or limb 14 having a second predetermined width dimension. Thread slot 13 and needle position or aperture 15 result from the bifurcation. An upstanding shank portion 18 is adapted to be secured in a conventional manner to a sewing machine.
In the preferred embodiment, the first limb 16 is wider than the second limb 14, and most preferably a width which is essentially twice the width of the second limb 14. In the piecing of quilted articles, or toy or doll making, the first limb 16 has a width of 1/4" from the center needle position 15 to the outside edge of the first limb 16. This width is useful for gauging the appropriate seam allowance. Likewise, the second limb 14 has a width of 1/8" from the center needle position 15 to the side edge of the second limb 14 so that this narrow limb 16 clears the previous seam allowance makes "easing" easier, prevents "tucks," and provides for better control, even in curved seams. As can be appreciated to those skilled in the art, the limbs 14 and 16 can be of any predetermined widths, depending on the stitching application and the system of measurement (e.g., English or metric systems). As used throughout the specification and claims, the clause "essentially about" concerning the dimension of limbs 14 and 16 is intended to cover the measurement from the needle position to the edges of the limbs 14 and 16.
In the preferred embodiment, grooves or indentations 20 are regularly spaced longitudinally along outer side or surface 22 of the first limb 16 and top surfaces 30 and 32 of the first limb 16 and second limb 14. However, those skilled in the art will recognize that the indentations need only be on one surface, or may be present on additional surfaces to those shown in the drawings, such as the inside surfaces of the limbs or on the outer surface of limb 14. Similarly, the indentations need not be regularly spaced but could be any selected distance from one another in accordance with a particular contemplated usage for the foot. Likewise, the indentations need not be grooved lines, such as shown in FIGS. 1-9, but could be, for example, V-shaped notches or indentations 25, 25' and 25" (such as shown in FIG. 10), or even U-shaped notches or indentations (not shown) to designate the spaced intervals. The indentations are preferably painted or marked with a coloration distinguishing the indentations from the surrounding portions of the limbs. As can be appreciated by those skilled in the art, markings, such as painted lines or shapes, could also be utilized rather than having a physical groove, notch, or other form of indentation, to designate spaced intervals. The term "indentations", as used throughout the specification and claims, is intended to include all such variations.
In the preferred embodiment, the indentations 20 (also see 25 in FIG. 10) are spaced essentially 1/4" from one another. This dimension is particularly important for piecing applications, in starting, stopping, and pivoting a quarter of an inch from the edge of the fabric.
As shown by the drawings, in the preferred embodiment useful for piecing applications, the limbs 14 and 16 comprise three sets of indentations 20 (or notches 25 such as shown in FIG. 10); one set of indentations 20 corresponding to and disposed adjacent the needle hole 15 through which the needle of the sewing machine passes; and the other two sets 20' and 20" spaced evenly (e.g. 1/4") from the first set of indentations 20 toward the toe (front) and heel (back) of the limbs respectively. It will be noted that the indentations 20, 20' and 20" on limb 16 match or correspond to indentations 20, 20' and 20" on limb 14 so that the user can easily align material perpendicular to the foot portion 12. This feature is particularly convenient for starting, stopping, or pivoting on a seam.
The foot 10 is not limited to any particular size or shape nor are the spacings of the indentations limited to any particular size or distance therebetween, but can be sized or spaced as appropriate for any stitching application and in any measurement system (e.g., English and metric marking systems). For example, the heel portion of the foot could be elongated to shortened and have various angles, depending on the sewing or stitching application, and depending on the sewing machine (e.g., different "feed dogs"). Likewise, the shank portion need not be as pictured in the drawings, but can be of any size or shape, depending on the sewing or stitching application and the sewing machine. The presser foot 10 may have its own shank portion or may attach to the shank portion of the sewing machine. The invention is intended to cover all such attachment means.
In operation, when piecing and stitching together a quilt, doll, or toy, for example, indentations 20 (or notches 25) are used to gauge distances from fabric edges or previous seams. This conveniently allows accurate starting, stopping, and pivoting on the stitched seam relative to such edges or previous seams, mitering corners, and setting in angles. FIG. 3 shows pivotal movement of the foot portion 12 to allow ease of movement over materials during stitching or sewing.
Further, seam allowance, which is critical in piecing of a quilted article, can accurately and conveniently be gauged by the predetermined width dimension of limb 16. Conversely, when later bypassing such seams, the narrow width of limb 14 renders such bypassing convenient. The potential barriers posed by previous seams are thus easily overcome.
The invention has been described in detail with particular reference to a preferred embodiment thereof, but it will be understood that variations and modifications can be effected within the scope of the invention.
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A presser foot for a sewing machine comprising a bifurcated foot having first and second limbs. the first limb is about twice as wide as the second limb. Selectively spaced indentations are provided on at least one of the limbs to facilitate accurate stitching. The indentations can be on the tops or the sides of the limbs.
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BACKGROUND OF THE INVENTION
This invention relates to siphons provided with pressure priming and pneumatic reflux.
Siphons with pressure priming and pneumatic reflux are known. In essence the top of a bell siphon is fitted with a pipe for the discharge of liquid, a pipe for the injection or extraction of a gas (air), and a priming device which, in the resting state, maintains under pressure a volume of air trapped during the submergence of the siphon in order to prevent self priming. A suitable pump attached to the priming device displaces the volume of air by compression and reflux and causes the siphon to be primed, so permitting the discharge of the liquid contained in the tank.
Implementation of the earlier proposals, although demonstrating the validity of the principle involved, has revealed difficulties and complications in the manufacture and operation of some of the devices envisioned.
SUMMARY OF THE INVENTION
An object of this invention is to provide improvements or modifications of the earlier proposals which, although not altering the fundamental concept of the basic and complementary features, do allow the manufacture of a more simple siphon which is reliable in operation, and which can be effected by moulding plastic material. In addition to this, the siphon may be fitted without special attachements to discharge pipes of different diameter.
According to the present invention there is provided a siphon with provision for pressure priming and pneumatic reflux, and comprising first and second cylindrical shells each open at one end and each provided with an inner cylinder, the shells and cylinders being arranged coaxially and in spaced relationship to each other so as to form a series of three annular coaxial chambers whose walls define a labyrinth, an upper chamber, and a lower chamber.
The internal shell, which is open upwards in its operating position, has a base opening in which its cylinder, in the form of a pipe for the discharge of the volume of compressed air, is mounted, said pipe which may also be formed by moulding, projects into the liquid discharge pipe.
The external shell, which opens downwardly in its operating position, may also be formed by moulding and is provided internally with an integral cylinder. An important feature is that the external shell opens into a bell part at its bottom end.
The bell part provided at the open end of the external shell of the siphon is received by a gasket which also receives the cylindrical pipe of the internal shell at a point where the said pipe projects from the said internal shell.
According to another feature of this invention, a suitably shaped socket member receives the gasket, holding it in place, and provides a support for the gasket by means of an annular flange which holds the gasket above the base of the socket member. The socket is provided with at least one opening in its base.
An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
The single FIGURE is a cross-sectional view of a siphon constructed in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawing, reference 1 denotes a water tank into which water enters via pipe 2 through a conventional valve 3 which is controlled by a float 4 to interrupt the flow of water when the tank is full, that is when the liquid has reached level L5.
A shaped socket member 6 at the bottom of the tank 1 carries a gasket or membrane 24. The gasket extends upwardly to surround bell part 21 of external shell 29 of the siphon which carries internal cylinder 31 attached to upper end of the shell 29. A second or internal shell 28, which is open at the top, is fitted centrally with respect to the gasket 24, and its base 27 carries an internal cylindrical pipe 26 which projects and opens into liquid discharge pipe 14.
Examining the member 6 in detail, it will be seen that it has a skirt which extends upwards, opening in that direction. Internal surface 7 of the member 6 is arranged to receive skirt 23 of the gasket 24 which also extends upwards, and the internal surface of the skirt 7 is formed with a shoulder 9 on which the gasket 24 may be supported. A central annular flange 12 extends upwardly from the socket member 6 to provide a valve seat at its upper end for cooperation with the gasket 24. The internal shoulder 9 in the gasket 24, and the flange 12 act to define a chamber 10. The object of this chamber will be explained below. In addition, the member 6 is formed with an inner rib 15 on which the water discharge pipe 14 seats.
As described, the gasket 24 includes a vertical annular skirt 23 which surrounds the bell part 21 of the siphon shell 29. The gasket 24 is also formed with a central opening through which the pipe 26 extends, and a downwardly extending skirt 25 surrounds the external surface of the pipe 26.
It can thus be appreciated that a unit has been formed in which the member 6 is in connection to the gasket 24, with the external shell 29 of the siphon by means of the bell part 21, and with the internal shell 28 of the siphon by means of the pipe 26. These different components are then held together by close fitting one with another, or by other means. The result is a complex siphon in which there are formed above the internal shell 28 and the pipe 26 attached to it, and between the internal shell and the closed upper end 30 of the external shell 29, two chambers, A and H respectively, whose purpose will be explained below.
A rubber tube 32 from which extends an air tube 33 ending at a control valve, is connected to chamber A at a suitable point on top end 30 of the shell 29.
The socket member 6 is formed with openings 11 in its base, which place the chamber 10 in communication with the liquid contained in the tank 1. Also, at the end of the horizontal section 21' which connects the body of the shell 29 to the bell part 21, passageways 21" are formed within the thickness of the wall forming the part 21, and the purpose of these passageways will be described below. Similarly, member 6 has a dependent annular flange 16 which receives the end of the pipe 14, according to another feature of this invention. The flange 16 has tapped bores 17 for fixing screws or bolts 20 which will be described below. A gasket 18 of frusto-conical shape is arranged below the flange 16, with its portion of greater diameter disposed outside the tank 1. Thus, when the bolts 20 are passed through a suitably drilled washer 19 and the gasket 18 to enter the tapped bores in the flange 16, and the bolts are tightened, the gasket 18 is deformed to form a sealing closure for the annular space existing between the pipe 14 and the central opening in the bottom of the tank 1. This is one of the advantages of the present construction and, as a result, it is possible to use a pipe 14 and a tank 1 whose relevant diameters are substantially different, and without requiring close tolerances between them. At the same time, the siphon assembly is securely held in place by the washer 19 which holds the member 6 against the bottom of tank 1, as shown in the drawing.
In the drawing, the following reference letters denote the following items:
L5 is the maximum level of the contents of tank 1;
L42 is the level of liquid in tank 1 corresponding to the top of the internal shell 28;
A is the annular chamber or cavity between the siphon shell 29 and the pipe 31, above the internal shell 28;
B is the annular chamber or cavity between the internal shell 28 and the cylinder 31;
C is the chamber or cavity between the cylinder 31 and the cylindrical pipe 26;
D is the height of a column of liquid between the base of the gasket 24 and the upper edge of the shell 28;
E is the height of a column of liquid between L42 and L5;
F is the annular chamber or cavity between the shell 29 and the cylinder 28;
G is the volume of liquid in the annular chamber B when the liquid has reached the level L5,
H is the cylindrical chamber or cavity in the cylinder 31 between the upper end of the pipe 26 and the top end 30 of the external shell 29.
In order to explain the operation of the above siphon, it will be assumed that tank 1 is initially empty, the siphon correspondingly is in the discharged state, and the gasket 24 engages the valve seat provided by the top of flange 12. If now water is caused to flow into tank 1 through valve 3, the water will reach the upper surface of the part 21' and will flow into the space above the gasket 24 through passageways 21", thus increasing the pressure of the gasket on the seat of flange 12. As the liquid leaves tank 1 it enters the chamber F and, when the liquid in the tank has reached the level L42, the water within the siphon will be at the level corresponding to the top end of the shell 28 to form a column of liquid of height D from the base of the gasket 24 and reaching up, as mentioned, to the top edge of shell 28. As the level of water rises in tank 1, the water in chamber F will spill over the edge of shell 28, falling into the chamber B from which it will rise into chamber C to prevent the escape of the air contained in chambers A and B. This forms a volume of air which is increasingly compressed as the column of liquid in chamber C rises.
When the level of liquid in tank 1 rises from level L42 to L5, chamber C gradually fills with liquid and, at the same time, the volume of air originally contained in chambers A and B, in tube 33, and in the dead spaces of the activating pump, will be compressed proportionately as a result of the increasing load of the hydrostatic head in chamber C. As a consequence, these volumes of air are reduced, and the difference between the initial volume and the reduced volume is taken up by a corresponding volume of liquid G contained in the lower part of chamber B.
When the liquid in the tak reaches level L5 valve 3 closes under the action of the float 4, and the siphon remains in a stable state with the volume of compressed air contained in chambers A and B - G counter-balanced by two opposing hydrostatic heads C - G and E of equal value.
If air is now passed under pressure through tube 33 to increase the pressure of the column of compressed air in the dead spaces of the pump, in the tube 33, and in the chambers A and B, air will enter into chamber A and lower the levels of liquid in chambers F and B. Because of the effect of this change in level, part of the air will pass into chamber C mixing with the water contained in it and decreasing the hydrostatic head. The external hydrostatic head E, which remains constant, overcomes the equilibrium and initiates the circulation of liquid within the siphon, the liquid acquiring a velocity suitable for the complete aspiration of the residual air in chamber B and in part of chamber A. This phenomenon occurs primarily as a result of the aspiration caused by the release of the activating pump and, therefore, by the return of air to the dead spaces in the pump. The water in tank 1 discharges via the discharge pipe 14 through the passageways 21", the bell part 21, chambers F, A, B and C, and the pipe 26.
If the parts of the siphon in contact with the liquid are suitably adjusted, particularly in level, low pressure is produced in the shell 31 by water which has passed through the pipe 26, and this low pressure raises the gasket 24 off the seat of flange 12. The gasket rises to close the passageways 21". Raising of gasket 24 partly opens the valve provided by the flange 12, and therefore opens a route for the discharge of water from the tank through the openings 11. As a result of the upward pressure of the water from tank 1 passing through the openings 11, the gasket 24 is pressed further to allow the rate of discharge to increase. The water entering into pipe 14 carries over a certain quantity of the air originally contained in that pipe, and causes a drop in pressure at the top of the pipe which is communicated through pipe 26 to the interior of the siphon. This low pressure raises the gasket 24 even further from the seat of the flange 12.
When the liquid in tank 1 drops to the level of the openings 11, air enters the pipe 14 which is emptied of water and returns to atmospheric pressure. Now, when the interior of the siphon is almost full of water and under low pressure, and the chamber H returns to ambient pressure of pipe 26, the liquid in chambers C and B, and in part in chambers A and F, is drawn down by the gasket 24 which falls in the bell part 21. The gasket 24 therefore falls and seats on the flange 12, thus closing the valve, and at the same time moves away from the passageway 21" to open the passageways. The initial condition is thus restored, although some of the liquid remains in chambers B and C.
It should be noted that, in the following cycles which are repeated during the operation of the siphon, the water contained in chambers B and C resists the head of liquid which forms outside the siphon while tank 1 is being filled since, in this case, the volume of air contained in the annular chambers E, A and B, pipe 33, and the pump, will be compressed before the level of the liquid reaches L42. Consequently, the head of liquid volume is cancelled, C achieves its full height, E is as high as C, and L5 will increase by the height of G.
Obviously, as in other siphons, the level L5 is at the ideal point for operation of the siphon, since it can be primed by a slightly lower level and will be primed automatically by a higher level.
As will now be appreciated, the operation of the siphon according to this invention is extremely simple and reliable, and requires minimum effort on the part of the user, given that a pressure exceeding only a few tens of centimetres of water must be applied.
Another important feature of this invention is the arrangement of pneumatic valves 34 and 34'. The said valves are of two types which may be mounted in alternative positions, i.e. on a wall and/or a floor. In fact, both valves, which are important for the operation of the siphon according to the invention, should fulfill the requirement of complete reliability, extreme simplicity and, at the same time, extremely economical operation.
Referring again to the drawing, the valve designated 34 comprises a barrel 35 which is connected by a pipe 37 to the tube 33. At the inner end of the valve there is a disc 38 preferably of rubber, with a central opening 36 which connects to the pipe 37. The disc 38 is inserted into barrel 35 under pressure and hermetically sealed in position. At the outer end of the barrel 35 there is fitted a cap 39 of resilient material. The cap projects beyond the barrel 35 and has an axial spigot part 40, preferably in the form of a frusto-cone, so as to seal hermetically with the internal wall of the barrel 35. Compression of the cap 39 compresses the air which is already pressurised as a result of the head in tank 1, as mentioned above, and the increase of pressure in tube 33 primes the siphon in the manner described.
The same result can be achieved by means of the pump denoted by reference 34', in which a barrel 35' is formed with a side 36' for the tube 33 which passes through a boss 37'. The tube 33 is attached to a resilient disc 38' which is secured in the barrel 35'. A cap 38" is formed with a central opening for a push-button 39', and has an integral cylindrical flange 40'. A shaped resilient ring 41', which ensures a hermetic seal between space 42' and atmosphere, is arranged between the external wall of the flange 40' and the internal wall of pipe 35'. The gasket 41' is preferably cup shaped and its which engages push button 39' is sufficiently elastic to be deformed by the push button. Deformation of the gasket 41' compresses the air within chamber 42', and the siphon then operates as described above.
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A liquid siphon including a tank and a pair of concentric shells within the tank. One end of the external-most shell has an enlarged bell part formed thereon. A deformable gasket is retained against an interior portion of the bell part to close the same. A passageway in the bell part communicates the interior thereof with the outside surface and is closed by the gasket when the same is deformed by priming the siphon.
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REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of application Ser. No. 09/415,278, filed Oct. 8, 1999, now U.S. Pat. No. ______, the contents of which are herein incorporated by reference.
FIELD OF THE INVENTION
[0002] This invention relates to the production of anti-cancer antibodies customized for the individual patient that can be used for therapeutic and diagnostic purposes. The invention further relates to the process by which the antibodies are made and to their methods of use.
BACKGROUND OF THE INVENTION
[0003] Each individual who presents with cancer is unique and has a cancer that is as different from other cancers as that person's identity. Despite this, current therapy treats all patients with the same type of cancer, at the same stage, in the same way. At least 30% of these patients will fail the first line therapy, thus leading to further rounds of treatment and the increased probability of treatment failure, metastases, and ultimately, death. A superior approach to treatment would be the customization of therapy for the particular individual. The only current therapy which lends itself to customization is surgery. Chemotherapy and radiation treatment can not be tailored to the patient, and surgery by itself, in most cases is inadequate for producing cures.
[0004] With the advent of monoclonal antibodies, the possibility of developing methods for customized therapy became more realistic since each antibody can be directed to a single epitope. Furthermore, it is possible to produce a combination of antibodies that are directed to the constellation of epitopes that uniquely define a particular individual's tumor.
[0005] Having recognized that a significant difference between cancerous and normal cells is that cancerous cells contain antigens that are specific to transformed cells, the scientific community has long held that monoclonal antibodies can be designed to specifically target transformed cells by binding specifically to these cancer antigens; thus giving rise to the belief that monoclonal antibodies can serve as “Magic Bullets” to eliminate cancer cells.
[0006] At the present time, however, the cancer patient usually has few options of treatment. The regimented approach to cancer therapy has produced improvements in global survival and morbidity rates. However, to the particular individual, these improved statistics do not necessarily correlate with an improvement in their personal situation.
[0007] Thus, if a methodology was put forth which enabled the practitioner to treat each tumor independently of other patients in the same cohort, this would permit the unique approach of tailoring therapy to just that one person. Such a course of therapy would, ideally, increase the rate of cures, and produce better outcomes, thereby satisfying a long-felt need.
[0008] Historically, the use of polyclonal antibodies has been used with limited success in the treatment of human cancers. Lymphomas and leukemias have been treated with human plasma, but there were few prolonged remission or responses. Furthermore, there was a lack of reproducibility and there was no additional benefit compared to chemotherapy. Solid tumors such as breast cancers, melanomas and renal cell carcinomas have also been treated with human blood, chimpanzee serum, human plasma and horse serum with correspondingly unpredictable and ineffective results.
[0009] There have been many clinical trials of monoclonal antibodies for solid tumors. In the 1980s there were at least four clinical trials for human breast cancer which produced only one responder from at least 47 patients using antibodies against specific antigens or based on tissue selectivity. It was not until 1998 that there was a successful clinical trial using a humanized anti-her 2 antibody in combination with Cisplatin. In this trial 37 patients were accessed for responses of which about a quarter had a partial response rate and another half had minor or stable disease progression.
[0010] The clinical trials investigating colorectal cancer involve antibodies against both glycoprotein and glycolipid targets. Antibodies such as 17-1A, which has some specificity for adenocarcinomas, had undergone Phase 2 clinical trials in over 60 patients with only one patient having a partial response. In other trials, use of 17-1A produced only one complete response and two minor responses among 52 patients in protocols using additional cyclophosphamide. Other trials involving 17-1A yielded results that were similar. The use of a humanized murine monoclonal antibody initially approved for imaging also did not produce tumor regression. To date there has not been an antibody that has been effective for colorectal cancer. Likewise there have been equally poor results for lung cancer, brain cancers, ovarian cancers, pancreatic cancer, prostate cancer, and stomach cancer. There has been some limited success in the use of anti-GD3 monoclonal antibody for melanoma. Thus, it can be seen that despite successful small animal studies that are a prerequisite for human clinical trials, the antibodies that have been tested have been for the most part ineffective.
PRIOR PATENTS
[0011] U.S. Pat. No. 5,750,102 discloses a process wherein cells from a patient's tumor are transfected with MHC genes which may be cloned from cells or tissue from the patient. These transfected cells are then used to vaccinate the patient.
[0012] U.S. Pat. No. 4,861,581 discloses a process comprising the steps of obtaining monoclonal antibodies that are specific to an internal cellular component of neoplastic and normal cells of the mammal but not to external components, labeling the monoclonal antibody, contacting the labeled antibody with tissue of a mammal that has received therapy to kill neoplastic cells, and determining the effectiveness of therapy by measuring the binding of the labeled antibody to the internal cellular component of the degenerating neoplastic cells. In preparing antibodies directed to human intracellular antigens, the patentee recognizes that malignant cells represent a convenient source of such antigens.
[0013] U.S. Pat. No. 5,171,665 provides a novel antibody and method for its production. Specifically, the patent teaches formation of a monoclonal antibody which has the property of binding strongly to a protein antigen associated with human tumors, e.g. those of the colon and lung, while binding to normal cells to a much lesser degree.
[0014] U.S. Pat. No. 5,484,596 provides a method of cancer therapy comprising surgically removing tumor tissue from a human cancer patient, treating the tumor tissue to obtain tumor cells, irradiating the tumor cells to be viable but non-tumorigenic, and using these cells to prepare a vaccine for the patient capable of inhibiting recurrence of the primary tumor while simultaneously inhibiting metastases. The patent teaches the development of monoclonal antibodies which are reactive with surface antigens of tumor cells. As set forth at col. 4, lines 45 et seq., the patentees utilize autochthonous tumor cells in the development of monoclonal antibodies expressing active specific immunotherapy in human neoplasia.
[0015] U.S. Pat. No. 5,693,763 teaches a glycoprotein antigen characteristic of human carcinomas and not dependent upon the epithelial tissue of origin.
[0016] U.S. Pat. No. 5,783,186 is drawn to Anti-Her2 antibodies which induce apoptosis in Her2 expressing cells, hybridoma cell lines producing the antibodies, methods of treating cancer using the antibodies and pharmaceutical compositions including said antibodies.
[0017] U.S. Pat. No. 5,849,876 describes new hybridoma cell lines for the production of monoclonal antibodies to mucin antigens purified from tumor and non-tumor tissue sources.
[0018] U.S. Pat. No. 5,869,268 is drawn to a method for producing a human lymphocyte producing an antibody specific to a desired antigen, a method for producing a monoclonal antibody, as well as monoclonal antibodies produced by the method. The patent is particularly drawn to the production of an anti-HD human monoclonal antibody useful for the diagnosis and treatment of cancers.
[0019] U.S. Pat. No. 5,869,045 relates to antibodies, antibody fragments, antibody conjugates and single chain immunotoxins reactive with human carcinoma cells. The mechanism by which these antibodies function is two-fold, in that the molecules are reactive with cell membrane antigens present on the surface of human carcinomas, and further in that the antibodies have the ability to internalize within the carcinoma cells, subsequent to binding, making them especially useful for forming antibody-drug and antibody-toxin conjugates. In their unmodified form the antibodies also manifest cytotoxic properties at specific concentrations.
[0020] U.S. Pat. No. 5,780,033 discloses the use of autoantibodies for tumor therapy and prophylaxis. However, this antibody is an antinuclear autoantibody from an aged mammal. In this case, the autoantibody is said to be one type of natural antibody found in the immune system. Because the autoantibody comes from “an aged mammal”, there is no requirement that the autoantibody actually comes from the patient being treated. In addition the patent discloses natural and monoclonal antinuclear autoantibody from an aged mammal, and a hybridoma cell line producing a monoclonal antinuclear autoantibody.
SUMMARY OF THE INVENTION
[0021] This application teaches a method for producing patient specific anti-cancer antibodies using a novel paradigm of screening. These antibodies can be made specifically for one tumor and thus make possible the customization of cancer therapy. Within the context of this application, anti-cancer antibodies having either cell-killing (cytotoxic) or cell-growth inhibiting (cytostatic) properties will hereafter be referred to as cytotoxic. These antibodies can be used in aid of staging and diagnosis of a cancer, and can be used to treat tumor metastases.
[0022] The prospect of individualized anti-cancer treatment will bring about a change in the way a patient is managed. A likely clinical scenario is that a tumor sample is obtained at the time of presentation, and banked. From this sample, the tumor can be typed from a panel of pre-existing anti-cancer antibodies. The patient will be conventionally staged but the available antibodies can be of use in further staging the patient. The patient can be treated immediately with the existing antibodies, and a panel of antibodies specific to the tumor can be produced either using the methods outlined herein or through the use of phage display libraries in conjunction with the screening methods herein disclosed. All the antibodies generated will be added to the library of anti-cancer antibodies since there is a possibility that other tumors can bear some of the same epitopes as the one that is being treated.
[0023] In addition to anti-cancer antibodies, the patient can elect to receive the currently recommended therapies as part of a multi-modal regimen of treatment. The fact that the antibodies isolated via the present methodology are relatively non-toxic to non-cancerous cells allow combinations of antibodies at high doses to be used, either alone, or in conjunction with conventional therapy. The high therapeutic index will also permit re-treatment on a short time scale that should decrease the likelihood of emergence of treatment resistant cells.
[0024] If the patient is refractory to the initial course of therapy or metastases develop, the process of generating specific antibodies to the tumor can be repeated for re-treatment. Furthermore, the anti-cancer antibodies can be conjugated to red blood cells obtained from that patient and re-infused for treatment of metastases. There have been few effective treatments for metastatic cancer and metastases usually portend a poor outcome resulting in death. However, metastatic cancers are usually well vascularized and the delivery of anti-cancer antibodies by red blood cells can have the effect of concentrating the antibodies at the site of the tumor. Even prior to metastases, most cancer cells are dependent on the host's blood supply for their survival and anti-cancer antibody conjugated red blood cells can be effective against in situ tumors, too. Alternatively, the antibodies may be conjugated to other hematogenous cells, e.g. lymphocytes, macrophages, monocytes, natural killer cells, etc.
[0025] There are five classes of antibodies and each is associated with a function that is conferred by its heavy chain. It is generally thought that cancer cell killing by naked antibodies are mediated either through antibody dependent cellular cytotoxicity or complement dependent cytotoxicity. For example murine IgM and IgG2a antibodies can activate human complement by binding the C-1 component of the complement system thereby activating the classical pathway of complement activation which can lead to tumor lysis. For human antibodies the most effective complement activating antibodies are generally IgM and IgG1. Murine antibodies of the IgG2a and IgG3 isotype are effective at recruiting cytotoxic cells that have Fc receptors which will lead to cell killing by monocytes, macrophages, granulocytes and certain lymphocytes. Human antibodies of both the IgG1 and IgG3 isotype mediate ADCC.
[0026] Another possible mechanism of antibody mediated cancer killing may be through the use of antibodies that function to catalyze the hydrolysis of various chemical bonds in the cell membrane and its associated glycoproteins or glycolipids, so-called catalytic antibodies.
[0027] There are two additional mechanisms of antibody mediated cancer cell killing which are more widely accepted. The first is the use of antibodies as a vaccine to induce the body to produce an immune response against the putative cancer antigen that resides on the tumor cell. The second is the use of antibodies to target growth receptors and interfere with their function or to down regulate that receptor so that effectively its function is lost.
[0028] Accordingly, it is an objective of the invention to teach a method for producing anti-cancer antibodies from cells derived from a particular individual which are cytotoxic with respect to cancer cells while simultaneously being relatively non-toxic to non-cancerous cells.
[0029] It is an additional objective of the invention to produce novel anti-cancer antibodies.
[0030] It is a further objective of the instant invention to produce anti-cancer antibodies whose cytotoxicity is mediated through antibody dependent cellular toxicity.
[0031] It is yet an additional objective of the instant invention to produce anti-cancer antibodies whose cytotoxicity is mediated through complement dependent cellular toxicity.
[0032] It is still a further objective of the instant invention to produce anti-cancer antibodies whose cytotoxicity is a function of their ability to catalyze hydrolysis of cellular chemical bonds.
[0033] Still an additional objective of the instant invention is to produce anti-cancer antibodies useful as a vaccine to produce an immune response against putative cancer antigen residing on tumor cells.
[0034] A further objective of the instant invention is the use of antibodies to target cell membrane proteins, such as growth receptors, cell membrane pumps and cell anchoring proteins, thereby interfering with or down regulating their function.
[0035] Yet an additional objective of the instant invention is the production of anti-cancer antibodies whose cell-killing utility is concomitant with their ability to effect a conformational change in cellular proteins such that a signal will be transduced to initiate cell-killing.
[0036] A still further objective of the instant invention is to produce anti-cancer antibodies which are useful for diagnosis, prognosis, and monitoring of cancer, e.g. production of a panel of therapeutic anti-cancer antibodies to test patient samples to determine if they contain any suitable antibodies for therapeutic use.
[0037] Yet another objective of the instant invention is to produce novel antigens, associated with cancer processes, which can be discovered by using anti-cancer antibodies derived by the process of the instant invention. These antigens are not limited to proteins, as is generally the case with genomic data; they may also be derived from carbohydrates or lipids or combinations thereof.
[0038] Other objects and advantages of this invention will become apparent from the following description wherein are set forth, by way of illustration and example, certain embodiments of this invention.
DETAILED DESCRIPTION OF THE INVENTION
[0039] It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification.
[0040] One of the potential benefits of monoclonal antibodies with respect to the treatment of cancer is their ability to specifically recognize single antigens. It was thought that in some instances cancer cells possess antigens that were specific to that kind of transformed cell. It is now more frequently believed that cancer cells have few unique antigens, rather, they tend to over-express a normal antigen or express fetal antigens. Nevertheless, the use of monoclonal antibodies provided a method of delivering reproducible doses of antibodies to the patient with the expectation of better response rates than with polyclonal antibodies.
[0041] Traditionally, monoclonal antibodies have been made according to fundamental principles laid down by Kohler and Milstein. Mice are immunized with antigens, with or without, adjuvants. The splenocytes are harvested from the spleen for fusion with immortalized hybridoma partners. These are seeded into microtitre plates where they can secrete antibodies into the supernatant that is used for cell culture. To select from the hybridomas that have been plated for the ones that produce antibodies of interest the hybridoma supernatants are usually tested for antibody binding to antigens in an ELISA (enzyme linked immunosorbent assay) assay. The idea is that the wells that contain the hybridoma of interest will contain antibodies that will bind most avidly to the test antigen, usually the immunizing antigen. These wells are then subcloned in limiting dilution fashion to produce monoclonal hybridomas. The selection for the clones of interest is repeated using an ELISA assay to test for antibody binding. Therefore, the principle that has been propagated is that in the production of monoclonal antibodies the hybridomas that produce the most avidly binding antibodies are the ones that are selected from among all the hybridomas that were initially produced. That is to say, the preferred antibody is the one with highest affinity for the antigen of interest.
[0042] There have been many modifications of this procedure such as using whole cells for immunization. In this method, instead of using purified antigens, entire cells are used for immunization. Another modification is the use of cellular ELISA for screening. In this method instead of using purified antigens as the target in the ELISA, fixed cells are used. In addition to ELISA tests, complement mediated cytotoxicity assays have also been used in the screening process. However, antibody-binding assays were used in conjunction with cytotoxicity tests. Thus, despite many modifications, the process of producing monoclonal antibodies relies on antibody binding to the test antigen as an endpoint.
[0043] Most antibodies directed against cancer cells have been produced using the traditional methods outlined above. These antibodies have been used both therapeutically and diagnostically. In general, for both these applications, the antibody has been used as the targeting agent that delivers a payload to the site of the cancer. These antibody conjugates can either be radioactive, toxic, or serve as an intermediary for further delivery of a drug to the body, such as an enzyme or biotin. Furthermore, it was widely held, until recently, that naked antibodies had little effect in vivo. Both HERCEPTIN and RITUXIMAB are humanized murine monoclonal antibodies that have recently been approved for human use by the FDA. However, both these antibodies were initially made by assaying for antibody binding and their direct cytotoxicity was not the primary goal during the production of hybridomas. Any tendency for these antibodies to produce tumor cell killing is thus through chance, not by design.
[0044] Although the production of monoclonal antibodies have been carried out using whole cell immunization for various applications the screening of these hybridomas have relied on either putative or identified target antigens or on the selectivity of these hybridomas for specific tissues. It is axiomatic that the best antibodies are the ones with the highest binding constants. This concept originated from the basic biochemical principle that enzymes with the highest binding constants were the ones that were the most effective for catalyzing a reaction. This concept is applicable to receptor ligand binding where the drug molecule binding to the receptor with the greatest affinity usually has the highest probability for initiating or inhibiting a signal. However, this may not always be the case since it is possible that in certain situations there may be cases where the initiation or inhibition of a signal may be mediated through non-receptor binding. The information conveyed by a conformational change induced by ligand binding can have many consequences such as a signal transduction, endocytosis, among the others. The ability to produce a conformational change in a receptor molecule may not necessarily be due to the filling of a ligand receptor pocket but may occur through the binding of another extra cellular domain or due to receptor clustering induced by a multivalent ligand.
[0045] The production of antibodies to produce cell killing need not be predicated upon screening of the hybridomas for the best binding antibodies. Rather, although not advocated by those who produce monoclonal antibodies, the screening of the hybridoma supernatants for cell killing or alternatively for cessation of growth of the cancerous cells may be selected as a desirable endpoint for the production of cytotoxic or cytostatic antibodies. It is well understood that the in-vivo antibodies mediate their function through the Fc portions and that the utility of the therapeutic antibody is determined by the functionality of the constant region or attached moieties. In this case the FAb portion of the antibody, the antigen-combining portion, will confer to the antibody its specificity and the Fc portion its functionality. The antigen combining site of the antibody can be considered to be the product of a natural combinatorial library. The result of the rearrangement of the variable region of the antibody can be considered a molecular combinatorial library where the output is a peptide. Therefore, the sampling of this combinatorial library can be based on any parameter. Like sampling a natural compound library for antibiotics, it is possible to sample an antibody library for cytotoxic or cytostatic compounds.
[0046] The various endpoints in a screen must be differentiated from each other. For example, the difference between antibody binding to the cell is distinct from cell killing. Cell killing (cytotoxicity) is distinct from the mechanisms of cell death such as oncosis or apoptosis. There can be many processes by which cell death is achieved and some of these can lead either to oncosis or apoptosis. There is speculation that there are other cell death mechanisms other than oncosis or apoptosis but regardless of how the cell arrives at death there are some commonalities of cell death. One of these is the absence of metabolism and another is the denaturation of enzymes. In either case vital stains will fail to stain these cells. These endpoints of cell death have been long understood and predate the current understanding of the mechanisms of cell death. Furthermore, there is the distinction between cytotoxic effects where cells are killed and cytostatic effects where the proliferation of cells are inhibited.
[0047] In a preferred embodiment of the present invention, the assay is conducted by focusing on cytotoxic activity toward cancerous cells as an end point. In a preferred embodiment, a live/dead assay kit , for example the LIVE/DEAD® Viability/Cytotoxicity Assay Kit (L-3224) by Molecular Probes, is utilized. The Molecular Probes kit provides a two-color fluorescence cell viability assay that is based on the simultaneous determination of live and dead cells with two probes that measure two recognized parameters of cell viability—intracellular esterase activity and plasma membrane integrity. The assay principles are general and applicable to most eukaryotic cell types, including adherent cells and certain tissues, but not to bacteria or yeast. This fluorescence-based method of assessing cell viability is preferred in place of such assays as trypan blue exclusion, Cr release and similar methods for determining cell viability and cytotoxicity.
[0048] In carrying out the assay, live cells are distinguished by the presence of ubiquitous intracellular esterase activity, determined by the enzymatic conversion of the virtually nonfluorescent cell-permeant CALCEIN AM to the intensely fluorescent Calcein. The polyanionic dye Calcein is well retained within live cells, producing an intense uniform green fluorescence in live cells (ex/em ˜495 nm/˜515 nm). EthD-1 enters cells with damaged membranes and undergoes a 40-fold enhancement of fluorescence upon binding to nucleic acids, thereby producing a bright red fluorescence in dead cells (ex/em ˜495 nm/˜635 nm). EthD-1 is excluded by the intact plasma membrane of live cells. The determination of cell viability depends on these physical and biochemical properties of cells. Cytotoxic events that do not affect these cell properties may not be accurately assessed using this method. Background fluorescence levels are inherently low with this assay technique because the dyes are virtually nonfluorescent before interacting with cells.
[0049] In addition to the various endpoints for screening, there are two other major characteristics of the screening process. The library of antibody gene products is not a random library but is the product of a biasing procedure. In the examples below, the biasing is produced by immunizing mice with fixed cells. This increases the proportion of antibodies that have the potential to bind the target antigen. Although immunization is thought of as a way to produce higher affinity antibodies (affinity maturation) in this case it is not. Rather, it can be considered as a way to shift the set of antigen combining sites towards the targets. This is also distinct from the concept of isotype switching where the functionality, as dictated by the constant portion of the heavy chain, is altered from the initial IgM isotype to another isotype such as IgG.
[0050] The third key feature that is crucial in the screening process is the use of multitarget screening. To a certain extent specificity is related to affinity. An example of this is the situation where an antigen has very limited tissue distribution and the affinity of the antibody is a key determinant of the specificity of the antibody—the higher the affinity the more tissue specific the antibody and likewise an antibody with low affinity may bind to tissues other than the one of interest. Therefore, to address the specificity issue the antibodies are screened simultaneously against a variety of cells. In the examples below the hybridoma supernatants (representing the earliest stages of monoclonal antibody development), are tested against a number of cell lines to establish specificity as well as activity.
[0051] The antibodies are designed for therapeutic treatment of cancer in patients. Ideally the antibodies can be naked antibodies. They can also be conjugated to toxins. They can be used to target other molecules to the cancer. e.g. biotin conjugated enzymes. Radioactive compounds can also be used for conjugation. The antibodies can be fragmented and rearranged molecularly. For example Fv fragments can be made; sFv-single chain Fv fragments; diabodies etc.
[0052] It is envisioned that these antibodies can be used for diagnosis, prognosis, and monitoring of cancer. For example the patients can have blood samples drawn for shed tumor antigens which can be detected by these antibodies in different formats such as ELISA assays, rapid test panel formats etc. The antibodies can be used to stain tumor biopsies for the purposes of diagnosis. In addition a panel of therapeutic antibodies can be used to test patient samples to determine if there are any suitable antibodies for therapeutic use.
EXAMPLE ONE
[0053] In order to produce monoclonal antibodies specific for a tumor sample the method of selection of the appropriate hybridoma wells is complicated by the probability of selecting wells which will produce false positive signals. That is to say that there is the likelihood of producing antibodies that can react against normal cells as well as cancer cells. To obviate this possibility one strategy is to mask the anti-normal antigen antibodies from the selection process. This can be accomplished by removing the anti-normal antibodies at the first stage of screening thereby revealing the presence of the desired antibodies. Subsequent limiting dilution cloning can delineate the clones that will not produce killing of control cells but will produce target cancer cell killing.
[0054] Biopsy specimens of breast, melanoma, and lung tumors were obtained and stored at −70° C. until used. Single cell suspensions were prepared and fixed with −30° C., 70% ethanol, washed with PBS and reconstituted to an appropriate volume for injection. Balb/c mice were immunized with 2.5×10 5 -1×10 6 cells and boosted every third week until a final pre-fusion boost was performed three days prior to the splenectomy. The hybridomas were prepared by fusing the isolated splenocytes with Sp2/0 and NS1 myeloma partners. The supernatants from the fusions were tested for subcloning of the hybridomas. Cells (including A2058 melanoma cells, CCD-12CoN fibroblasts, MCF-12A breast cells among others) were obtained from ATCC and cultured according to enclosed instructions. The HEY cell line was a gift from Dr. Inka Brockhausen. The non-cancer cells, e.g. CCD-12CoN fibroblasts and MCF-12A breast cells, were plated into 96-well microtitre plates (NUNC) 1 to 2 weeks prior to screening. The cancer cells, e.g. HEY, A2058, BT 483, and HS294t, were plated two or three days prior to screening.
[0055] The plated normal cells were fixed prior to use. The plates were washed with 100 microliters of PBS for 10 minutes at room temperature and then aspirated dry. 75 microliters of 0.01 percent glutaraldehyde diluted in PBS were added to each well for five minutes and then aspirated. The plates were washed with 100 microliters of PBS three times at room temperature. The wells were emptied and 100 microliters of one percent human serum albumin in PBS was added to each well for one hour at room temperature. The plates were then stored at four degrees Celsius.
[0056] Prior to the transfer of the supernatant from the hybridoma plates the fixed normal cells were washed three times with 100 microliters of PBS at room temperature. After aspiration to the microliters of the primary hybridoma culture supernatants were transferred to the fixed cell plates and incubated for two hours at 37 degrees Celsius in a 8 percent CO 2 incubator. The hybridoma supernatants derived from melanoma was incubated with CCD-12 CoN cells and those derived from breast cancer were incubated with MCF-12a cells.
[0057] After incubation the absorbed supernatant was divided into two 75 microliter portions and transferred to target cancer cell plates. Prior to the transfer the cancer cell plates were washed three times with 100 microliters of PBS. The supernatant from the CCD-12 CoN cells were transferred to the A2058 and the HS294t cells, whereas the supernatant from MCF-12A cells were transferred to the HEY and BT 483 cells. The cancer cells were incubated with the hybridoma supernatants for 18 hours at 37 degrees Celsisu in an 8 percent CO 2 incubator.
[0058] The Live/Dead cytotoxicity assay was obtained from Molecular Probes (Eu,OR). The assays were performed according to the manufacturer's instructions with the changes outlined below. The plates with the cells were washed once with 100 microliters of PBS at 37° C. 75 to 100 microliters of supernatant from the hybridoma microtitre plates were transferred to the cell plates and incubated in a 8% CO 2 incubator for 18-24 hours. Then, the wells that served as the all dead control were aspirated until empty and 50 microliters of 70% ethanol was added. The plate was then emptied by inverting and blotted dry. Room temperature PBS was dispensed into each well from a multichannel squeeze bottle, tapped three times, emptied by inversion and then blotted dry. 50 microliters of the fluorescent Live/Dead dye diluted in PBS was added to each well and incubated at 37° C. in a 5% CO 2 incubator for one hour. The plates were read in a Perkin-Elmer HTS7000 fluorescence plate reader and the data was analyzed in Microsoft Excel.
[0059] Four rounds of screening were conducted to produce single clone hybridoma cultures. For two rounds of screening the hybridoma supernatants were tested only against the cancer cells. In the last round of screening the supernatant was tested against a number of non-cancer cells as well as the target cells indicated in table 1. The antibodies were isotyped using a commercial isotyping kit.
[0060] A number of monoclonal antibodies were produced in accordance with the method of the present invention. These antibodies, whose characteristics are summarized in Table 1, are identified as 3BD-3, 3BD-6, 3BD-8, 3BD-9, 3BD-15, 3BD-25, 3BD-26 and 3BD-27. Each of the designated antibodies is produced by a hybridoma cell line deposited with the American Type Culture Collection at 10801 University Boulevard, Manassas, Va. having an ATCC Accession Number as follows:
[0061] Antibody ATCC Accession Number
[0062] 3BD-3
[0063] 3BD-6
[0064] 3BD-8
[0065] 3BD-9
[0066] 3BD-15
[0067] 3BD-25
[0068] 3BD-26
[0069] 3BD-27
[0070] These antibodies are considered monoclonal after four rounds of limiting dilution cloning. The anti-melanoma antibodies did not produce significant cancer cell killing. The panel of anti-breast cancer antibodies killed 32-87% of the target cells and <1-3% of the control cells. The predominant isotype was IgG1 even though it was expected that the majority of anti-tumor antibodies would be directed against carbohydrate antigens, and thus, be of the IgM type. There is a high therapeutic index since most antibodies spare the control cells from cell death.
Table 1. Anti-Breast Cancer Antibodies
[0071] [0071] % Cell Death Normal Target for Anti-Breast Fibroblast Fibrocystic Cancer Antibodies Cells Breast Cells Clones (HEY & A2058) (CCD-12CoN) (MCF-12A) Isotype 3BD-3 74.9% 3.7% <1% y1, λ 3BD-6 68.5% 5.6% <1% y1, λ 3BD-8 81.9% 4.5% 2.6% y1, κ 3BD-9 77.2% 7.9% <1% y1, λ 3BD-15 87.1% <1% <1% y1, λ 3BD-26 54.8% 3.3% <1% μ, κ 3BD-25 32.4% 3.6% <1% y1, κ 3BD-27 60.1% 8.3% 1.3% y1, κ
EXAMPLE 2
[0072] In this example customized anti-cancer antibodies are produced by first obtaining samples of the patient's tumor. Usually this is from a biopsy specimen from a solid tumor or a blood sample from hematogenous tumors. The samples are prepared into single cell suspensions and fixed for injection into mice. After the completion of the immunization schedule the hybridomas are produced from the splenocytes. The hybridomas are screened against a variety of cancer cell lines and normal cells in standard cytotoxicity assays. Those hybridomas that are reactive against cancer cell lines but are not reactive against normal non-transformed cells are selected for further propagation. Clones that were considered positive were ones that selectively killed the cancer cells but did not kill the non-transformed cells. The antibodies are characterized for a large number of biochemical parameters and then humanized for therapeutic use. The melanoma tumor cells isolated and cell lines were cultured as described in Example 1. Balb/c mice were immunized according to the following schedule: 200,000 cells s.c. and i.p. on day 0, then 200,000 cells were injected i.p. on day 21, then 1,000,000 cells were injected on day 49, then 1,250,000 cells in Freund's Complete Adjuvant were injected i.p. on day 107, and then 200,000 cells were injected on day 120 i.p. and then the mice were sacrificed on day 123. The spleens were harvested and the splenocytes were divided into two aliquots for fusion with Sp2/0 (1LN) or NS-1 (2LN) myeloma partners using the methods outlined in example 1.
[0073] The screening was carried out 11 days after the fusion against A2058 melanoma cells and CCD-12CoN fibroblasts. Each pair of plates were washed with 100 microliters of room temperature PBS and then aspirated to near dryness. Then 50 microliters of hybridoma supernatant was added to the same wells on each of the two plates. The spent Sp2/0 supernatant was added to the control wells at the same volume and the plates were incubated for around 18 hours at 37 degrees Celsius at a 8% CO 2 , 98% relative humidity incubator. Then each pair of plates were removed and in the positive control wells 50 microliters of 70% ethanol was substituted for the media for 4 seconds. The plates were then inverted and washed with room temperature PBS once and dried. Then 50 uL of fluorescent live/dead dye diluted in PBS (Molecular Probes Live/Dead Kit) was added for one hour and incubated at 37 degrees Celsius. The plates were then read in a Perkin-Elmer fluorescent plate reader and the data analyzed using Microsoft Excel. The wells that were considered positive were subcloned and the same screening process was repeated 13 days later and then 33 days later. The results of the last screening is outlined in Table 2 below. A number of monoclonal antibodies were produced in accordance with the method of the present invention. These antibodies, whose characteristics are summarized in Table 2, are identified as 1LN-1, 1LN-12, 1LN-14, 2LN-21, 2LN-28, 2LN-29, 2LN-31, 2LN-33, 2LN-34 and 2LN-35. Each of the designated antibodies is produced by a hybridoma cell line deposited with the American Type Culture Collection at 10801 University Boulevard, Manassas, Va. having an ATCC Accession Number as follows:
[0074] Antibody ATCC Accession Number
[0075] 1LN-1
[0076] 1LN-12
[0077] 1LN-14
[0078] 2LN-21
[0079] 2LN-28
[0080] 2LN-29
[0081] 2LN-31
[0082] 2LN-33
[0083] 2LN-34
[0084] 2LN-35
TABLE 2 Anti-Melanoma Antibodies % Cell Death Target for Anti- Melanoma Normal Fibroblast Antibodies Cells Clones (A2058) (CCD-1 2CoN) 1LN-1 59.4% <1% 1LN-12 55.2% 1.4% 1LN-14 51.4% <1% 2LN-21 72.0% 15.9% 2LN-28 66.6% 12.4% 2LN-29 78.2% 6.1% 2LN-31 100% 7.8% 2LN-33 94.2% <1% 2LN-34 56.6% 11.2% 2LN-35 66.5% 6.6%
[0085] The table illustrates that clones from both the Sp2/0 and NS-1 fusions were able to produce antibodies that had a greater than 50% killing rate for cancerous cells and at the same time some of the clones were able to produce less than one percent killing of normal control fibroblasts.
[0086] The anti-cancer antibodies of the invention are useful for treating a patient with a cancerous disease when administered in admixture with a pharmaceutically acceptable adjuvant, for example normal saline, a lipid emulsion, albumen, phosphate buffered saline or the like and are administered in an amount effective to mediate treatment of said cancerous disease, for example with a range of about 1 microgram per mil to about 1 gram per mil.
[0087] The method for treating a patient suffering from a cancerous disease may further include the use of conjugated anti-cancer antibodies and would this include conjugating patient specific anti-cancer antibodies with a member selected from the group consisting of toxins, enzymes, radioactive compounds, and hematogenous cells; and administering these conjugated antibodies to the patient; wherein said anti-cancer antibodies are administered in admixture with a pharmaceutically acceptable adjuvant, for example normal saline, a lipid emulsion, albumen, phosphate buffered saline or the like and are administered in an amount effective to mediate treatment of said cancerous disease, for example with a range of about 1 microgram per mil to about 1 gram per mil. In a particular embodiment, the anti-cancer antibodies useful in either of the above outlined methods may be a humanized antibody.
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The present invention relates to a method for producing patient specific anti-cancer antibodies using a novel paradigm of screening. By segregating the anti-cancer antibodies using cancer cell cytotoxicity as an end point, the process makes possible the production of anti-cancer antibodies customized for the individual patient that can be used for therapeutic and diagnostic purposes. The invention further relates to the process by which the antibodies are made and to their methods of use. The antibodies can be made specifically for one tumor derived from a particular patient and are selected on the basis of their cancer cell cytotoxicity and simultaneous lack of toxicity for non-cancerous cells. The antibodies can be used in aid of staging and diagnosis of a cancer, and can be used to treat tumor metastases. The anti-cancer antibodies can be conjugated to red blood cells obtained from that patient and re-infused for treatment of metastases based upon the recognition that metastatic cancers are usually well vascularized and the delivery of anti-cancer antibodies by red blood cells can have the effect of concentrating the antibodies at the site of the tumor.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to measuring and testing generally and to fluid pressure measurement, in particular.
2. Description of the Related Art
There are several methods for the measurement of pressures in fluid dynamics research. One particularly useful approach employs either piezoresistive or metallic strain gauges bonded to either a silicon or a stainless steel diaphragm. With the proper compensation procedures to account for zero balance and thermal effects, these devices are very useful in the determination of fluid pressure levels in wind tunnels and other environments and also are sufficiently inexpensive to allow large numbers to be used in a research facility.
As with any other strain gauge device, there are limits to the range and accuracy of this specific strain gauge installation. For example, the accuracy of these devices depends upon the minute deflection of a thin diaphragm with a strain gauge installed on its surface. The application of pressure to this diaphragm causes it to deflect, thus introducing in the surface a strain which is detected by the strain gauge and which is also proportional to the load applied. Appropriate calibration and compensation procedures permit the applied pressure to be measured as a function of the electrical output of the strain gauge.
Range limitations occur because of the inherent restriction imposed by the applied pressure level to which the diaphragm can be exposed before exceeding either its linear response range or its ultimate stress limit, thus deforming the diaphragm and the strain gauge into a region of either nonrepetable results or failure.
In order to obtain maximum accuracy, it is desirable to maximize the amount of deflection. In other words, it is preferably to obtain a large deflection for a small applied pressure. However, in doing so, a transducer is limited in its amount of permissible overpressure, thus limiting its range of accurate measurement.
This conflict between desired accuracy and maximum range results in users being left with a choice between very accurate transducers with a limited range of safe overpressure and less accurate transducers that can be safely exposed to a wide range of high overpressure.
One method of minimizing this problematic choice involves electronic conditioning and amplifying of the output signal using a so-called auto ranging technique by which a variable gain is applied to the strain gauge output such that the final output simulates a nearly full scale reading, regardless of the applied pressure.
A major disadvantage of this method is that noise is also amplified along with the electrical signal. Furthermore, the output is still in reality the result of a small movement of the diaphragm.
Thus, the solution before undertaking most tests is to match carefully the transducer size with the pressure range expected to be encountered. Of course, this solution is not applicable to tests wherein the measured fluid pressure varies over a wide range.
SUMMARY OF THE INVENTION
Two or more pressure transducers of different ranges are used with a circuit that electronically selects the output from the transducer reading closest to full scale. Each successive transducer has a larger range than its preceding transducer. For example, a first transducer may have a scale of zero to two pounds per square inch and a second transducer may have a scale of zero to 15 pounds per square inch.
A primary feature of the invention is to have all of the pressure ports connected together in parallel so that all transducers are exposed to the same pressure. Similarly, all reference ports are also connected together.
A further object of the invention is to rely on the use of a new generation of pressure traducers with strain gauges fabricated as an integral part of the Diaphragm. A key advantage of these strain gauges is that they are capable of being exposed to large over pressures without damage and with a lack of any significant pressure hysteresis.
The results achieved by the invention are made possible because the strain gauges associated with this new generation of pressure transducers can be exposed to large overpressures without being damaged and with a lack of any significant pressure hysteresis.
These and other features, objects and results obtained by the invention will become more readily apparent from a review of the following brief description of the drawings and the subsequent detailed description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of a first embodiment of the invention.
FIG. 2 is a graphical representation of the possible results obtainable by the first embodiment of the invention.
FIG. 3a is a graphical representation of the output obtainable from a first transducer used in a second embodiment of the invention.
FIG. 3b is a graphical representation of the output obtainable from a second transducer used in the second embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A schematic representation of a first embodiment of the invention is shown in FIG. 1. Initially, a sensor 5, which may be any one of a strain gauge, a capacitive pressure sensor, or an inductive pressure sensor, measures pressure in a fluid line (not shown). A first transducer 10 is denoted in FIG. 1 as No. 1 and operates in a low pressure range of, for example, zero to two pounds per square inch. A second transducer 20 as denoted No. 2 and operates in a high pressure range of, for example, zero to 15 pounds per square inch. A fluid line 30 for measured pressure branches into two ports 31 and 32 leading to the transducers 10 and 20, respectively. Thus, the ports 31 and 32 are effectively connected together in parallel so that the transducers 10 and 20 are exposed to the same measured pressure. Similarly, a fluid line 40 for a reference pressure branches into two ports 41 and 42, also leading to the transducer 10 and 20, respectively; thus, the ports 41 and 42 are effectively connected together in parallel so that the transducers 10 and 20 are exposed to the same reference pressure.
This arrangement is made possible because, for example, these strain gauges can be exposed to large overpressures without being damaged. Also, this arrangement is made possible because these strain gauges can be exposed to large overpressures without undergoing an significant pressure hysteresis. In other words, subjecting the strain gauge to pressures substantially greater than the pressures of the working range of the strain gauge does not adversely affect the accuracy of the strain gauge on subsequent measurements within the working range thereof.
An electronic signal or output from the low-range transducer 10 is routed via a first electrical line 15 to a first instrumentation amplifier 50 which amplifies the low-level output in mullivolts to a high-level output in the range of about one volt to five volts maximum. At the same time, an electronic signal or output from the high range transducer 20 is routed via a second electrical line 25 to a second instrumentation amplifier 60 which likewise amplifies the low-level output in millivolts to a high-level output in the same range of about one volt to five volts maximum. The amplified output from the first instrumentation amplifier 50 is then routed via a third electrical ine 55 to a comparator 70. Similarly, the amplified output from the second instrumentation amplifier 60 is also routed via a fourth electrical line 65 to the comparator 70. It will be readily apparent that, while two transducers have been illustrated, additional strain gauge transducers with successively broader operative pressure ranges may be added when larger overall ranges of pressure are to be measured, each of the added transducers also furnishing an output signal which is amplified and supplied as an input to the comparator 70.
The comparator 70 selects from among the various inputs the one input for which the respective pressure transducer is outputting at a level most closely approaching, but below, the full range or maximum measurable pressure level for that respective transducer and generates, from the selected input, an output signal which is transmitted via a fifth electrical line 75 to a visual display or other data recording device (not shown). In the illustrated two-transducer arrangement, the selection function may be accomplished by continuously monitoring the signal generated by one of the transducers, for example, the high-range transducer 20, to determine if the monitored signal is below or above a predetermined threshold level, such as 12% of the full range or maximum signal level corresponding to the monitored transducer, with the low-range transducer signal being selected for output signal generation when the monitored signal is below the threshold level and the high-range transducer being selected otherwise.
In order to prevent oscillation or hunting, separate threshold levels for rising and falling monitored signal levels are, preferably, employed. In a three-transducer configuration, selection of the output signal may be accomplished by a monitoring of the level of the signal generated by the intermediate-range transducer with respect to separate lower and upper threshold levels at, for example, 30% and 75%, respectively, of the full-range signal for this transducer, with the low-range transducer signal being selected when the monitored signal level is below the lower threshold, the high-range transducer signal being selected when the monitored signal level is above the upper threshold, and the intermediate-range transducer signal being selected when the monitored signal level is within the limits of the lower and upper thresholds. In a similar manner, configurations having more than three pressure transducers may employ output signal selection arrangements involving the separate monitoring of the signals from each of the intermediate-range transducers with corresponding lower and upper threshold levels.
The comparator output signals over the line 75 may be "nested", as illustrated in FIG. 2, so that the output signal of the comparator 70 continuously increases in voltage with increasing pressure. This nesting is accomplished by varying the gain and the offset of the comparator output generating circuit in accordance with the identity of the one transducer signal which has been selected to generate the signal over the line 75. In this mode, the output signal appears as that of a single transducer operable over the entire pressure range. As is shown in FIG. 2, the output signal is generated from the signal produced by the low-range transducer 10 when the sensed pressure is two pounds per square inch (psi) or less while the signal produced by the high-range transducer 20 is employed when the sensed pressure is above two psi.
Other forms of the output signal may be provided and, for this purpose, an output selection switch 80 is provided, communicating with the comparator 70 via a sixth electrical line 85.
A second output mode is shown in FIGS. 3a and 3b. In this full mode, the full-range signal of the selected pressure transducer is output without conditioning of the signal and is accompanied by an identification of the selected transducer. The selection switch also provides for outputting of the signal corresponding to any one of the transducers without regard to whether this transducer is the one selected by the comparator 70.
In the two alternative embodiments discussed above, the present invention will appear as a compound transducer using either manual selection or automatic selection, but with higher accuracy over larger pressure levels than a single standard transducer subject to variable amplification.
To summarize the invention, the circuit is designed to provide output in one of two modes: first, the nested mode in which a single output signal is generated throughout the full pressure range regardless of which one of the transducers is selected as active; and second, the manually selected mode in which the user selects one of the transducers to furnish the output signal. FIG. 2 is a depiction of the output in the first nested mode while FIGS. 3a and 3b illustrate the output in the second full mode.
In regard to FIG. 2, the legend at the top indicates which one of the two transducers is active at a given pressure. Thus, when the measured pressure is below the upper limit of the low-pressure transducer No. 1, this transducer 10 is active and the output of the high-pressure transducer 20 is ignored. When the measured pressure exceeds that upper limit, the situation is reversed.
In regard to FIGS. 3a and 3bthe pressure range for each transducer is given on the abscissa of the corresponding graph. The identification of the transducer No. 1 or No. 2 is needed because, in this mode, the output signal includes both the measured pressure and identification of the particular transducer 10 or 20.
The present invention may also involve the organization of several units shown in FIG. 1 into one or more groups for the measurement of more than one fluid pressure at the same time. Multiplexing of the various electronic signals or outputs 75 would then be possible, thus providing the invention with a capability similar to that of either mechanically or electrically scanned fluid pressure measuring systems.
Furthermore, the automatic transducer selection system of the present invention for pressure measurement can be applied in any research environment where standard pressure transducers are used. The inventive system may be especially advantageously used in environments where the measured pressure varies over a wide range, such as in the measurement of fluid pressure in airfoil wakes, and in situations where a reliable estimate of the fluid pressure needed for proper transducer selection is not known beforehand.
The foregoing preferred embodiments are considered illustrative only. Numerous other modifications may readily occur to those persons skilled in electronics technology after reading this specification. Consequently, the disclosed invention is not limited by the exact construction and operation shown and described above but rather is defined by the claims appended hereto.
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An automatic transducer selection system for fluid pressure measurement functions by using two or more transducers wtih different .Iadd.measurement .Iaddend.ranges .[.of accuracy.]. and also by incorporating comparator circuitry which automatically selects the transducer reading nearer to full scale. An electronic signal or output from the comparator is preferably nested such that a continuous voltage is generated in accordance with the fluid pressure being measured, this making the system appear to function as a single transducer with a wide .Iadd.measurement .Iaddend.range of .Iadd.high .Iaddend.accuracy.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. patent application Ser. No. 11/137,705 now U.S. Pat. No. 7,610,731, file May 25, 2005 which is a continuation-in-part of U.S. patent application Ser. No. 11/032,196 filed on Jan. 10, 2005 and converted to a U.S. Provisional Application Ser. No. 60/651,490 on May 20, 2005 and having a filing date of Jan. 10, 2005. Priority is claimed from all the above applications.
FIELD OF THE INVENTION
The present invention relates to floor coverings and methods of use thereof.
BACKGROUND OF THE INVENTION
Applying new flooring may provide enhanced aesthetic appeal or fulfill a functional purpose. Generally, applying flooring requires the use of staples, nails or an adhesive to adhere the flooring material to the sub-floor. Depending on the combination of sub-floor type, new flooring installed and the particular adhesive used, applying new flooring may damage the sub-floor through scuffing, gauging, nail holes or chemical damage. For example, with marble floors, a conventional installation damages the sub-floor from the tar paper, wire mesh, mortar bed, adhesive and grout used to lay the marble, and the damage is compounded by the weight of the marble and use of the floor. This may be undesirable and require extensive restoration efforts if the sub-floor is hardwood.
Furthermore, certain flooring materials may be expensive and the addition of labor expenses may make a new floor unattainable for price-conscious consumers. While a do-it-yourself application may reduce the costs, some consumers may be apprehensive to use particular adhesives or grout which may require planning for timing, ventilation and settling. For example, using a cement backer board, which is designed to be easier than the conventional installation described above, requires that a cement board be attached to a plywood sub-floor using adhesives and screws, then bonding the tile to the backer board using a thin set adhesive placed over a fiberglass reinforcing mesh.
It may be desirable to provide a “floating” floor structure which provides the appearance of a permanent flooring structure at a reduced cost but without the use of damaging permanent attachment means to secure the structure to the floor. It may be desirable that the installation is primarily mechanical, not requiring the use of chemical adhesives. It may also be desirable to provide a floor structure that is stable and does not substantially shift upon using the floor.
SUMMARY OF THE INVENTION
The present invention provides a floor structure unit, comprising: a tray, a flooring material, a rubber grommet, and a rubber matrix. The tray includes an upper horizontal surface, a lower horizontal surface, at least one retaining wall extending vertically from either of the horizontal surfaces, a first set of interlocking members, and a second set of interlocking members, where the first set of interlocking members and the second set of interlocking members are contrapositive. The flooring material is disposed on the tray upper horizontal surface such that the first set of interlocking members is substantially flush with the flooring material and the second set of interlocking members extends beyond the flooring material. The rubber matrix is disposed in the tray lower horizontal surface, and the rubber grommet is disposed about the perimeter of the at least one retaining wall. The rubber grommet and the rubber matrix are a unitary piece.
The present invention also provides a method of making a floor structure unit, comprising providing tray having interlocking members disposed thereon; placing a rubber grommet around the perimeter of the tray; attaching a rubber matrix onto a lower horizontal surface of the tray; and securing a flooring material to an upper horizontal surface of the tray.
The present invention also provides a method of placing a floor structure, comprising: interlocking contrapositive members of at least two floor structure units. The floor structure units comprise: a tray, a flooring material, a rubber grommet, and a rubber matrix. The tray includes an upper horizontal surface, a lower horizontal surface, at least one retaining wall extending vertically from either of the horizontal surfaces, a first set of interlocking members, and a second set of interlocking members, where the first set of interlocking members and the second set of interlocking members are contrapositive. The flooring material is disposed on the tray upper horizontal surface such that the first set of interlocking members is substantially flush with the flooring material and the second set of interlocking members extends beyond the flooring material. The rubber matrix is disposed in the tray lower horizontal surface, and the rubber grommet is disposed about the perimeter of the at least one retaining wall. The rubber grommet and the rubber matrix are a unitary piece.
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 embodiments 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 depicts a perspective view of a floor structure unit according to embodiments of the present invention;
FIG. 2 depicts a top view of a tray according to embodiments of the present invention;
FIG. 3 depicts a perspective view of a tray and retaining walls according to embodiments of the present invention;
FIG. 4 depicts a bottom view of a tray, rubber grommet, and rubber matrix according to embodiments of the present invention;
FIG. 5 depicts a perspective view of a tray and rubber grommet according to embodiments of the present invention.
FIG. 6 depicts a side view of a floor structure unit according to embodiments of the present invention;
FIG. 7 a depicts a side view of a floor structure unit according to embodiments of the present invention;
FIGS. 7 b - c depict exploded corner views of the side view of FIG. 7 a ; and
FIG. 8 depicts a side view of a tray, stone and rubber grommet according to embodiments of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
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.
FIGS. 1-4 depict a floor structure unit 10 comprising a tray 12 , having a first set 14 of interlocking members 16 , a second set 18 of interlocking members 16 , a rubber matrix 20 , a flooring material 22 , and a rubber grommet 24 . The tray 12 , the rubber matrix 20 , the flooring material 22 and the rubber grommet 24 of the floor structure unit 10 are attached using an adhesive or glue.
As depicted in FIG. 3 , the tray 12 is a square and comprises an upper horizontal surface 26 and a lower horizontal surface 28 . It is understood that the tray 12 may be of any appropriate shape (polygon, circular, freeform, etc.) and a square is depicted and discussed herein for illustrative purposes only and that one skilled in the art appreciates and understands slight modifications to accommodate various shapes. The upper horizontal surface 26 is the substrate for the flooring material 22 as discussed later herein.
The lower horizontal surface 28 includes the substrate for the sets of interlocking members 14 and 18 and serves as the substrate for attachment of the rubber matrix 20 and interconnected rubber grommet 24 . Each tray 12 interlocking member 16 comprises a notch 30 and a recessed segment 32 . The notch 30 is generally a protrusion of a greater thickness than the recessed segment 32 . The protrusion may be rounded, squared or an irregular shape. The notch 30 connects with the recessed segment 32 of an adjacent floor structure unit 10 for a secure fit. Generally, the notch 30 of a first interlocking member 16 connects with the recessed portion 32 of a second interlocking member 16 . In various embodiments, it may be desirable to have complimentary shaped notches 30 and recessed segments 32 . For example, a rounded notch 30 mating with a rounded hollowed recessed segment 32 may provide a secure fit thereby preventing slippage of the floor structure.
The sets 14 and 18 of interlocking members 16 may be arranged such that all of the notches 30 face towards either the upper horizontal surface 26 or lower horizontal surface 28 of the tray 12 , as depicted in FIGS. 2 and 4 . Preferably, each interlocking member 16 of the sets 14 and 18 alternate where one notch 30 faces towards the upper horizontal surface 26 and then the adjacent notch 30 faces towards the lower horizontal surface 28 , as depicted in FIGS. 1 , 3 , and 5 . In a preferred embodiment, the notches 30 and recessed segments 32 are arranged such that the first set 14 and the second set 18 of interlocking members 16 are contrapositive. This contrapositive arrangement provides the lock fit and structural integrity of the flooring system.
The lower horizontal surface 26 may also comprise a grid 34 . The grid 34 may be produced when the tray 12 is injection molded. The grid 34 may include any geometric or curved pattern or a random pattern to provide greater surface area for the rubber matrix 20 and in various embodiments, an optional adhesive 36 .
Referring to FIG. 5 , the tray 12 may also include retaining or side walls 40 . These walls 40 may be used to hold the flooring material 22 in a fixed position, provide strength, and prevent debris from reaching the sub-floor. Preferably, the retaining walls 40 upwardly extend from two adjacent sides of the tray 12 . The retaining walls 40 provide enhanced support to components of the flooring unit 10 . The walls 40 support the rubber grommet 24 on the tray 12 , as further detailed later herein, and are used as a projection point for interlocking members 16 , as depicted in FIGS. 7 a - c and FIG. 8 .
Referring to FIG. 6 , the flooring material 22 is disposed on the upper horizontal surface 26 of the tray 12 . Flooring materials 22 may include traditional materials 22 such as stone, wood, ceramic, textile, paper, plastic materials 22 , and mixtures thereof. Stone materials preferably include slate, limestone, flagstone, granite, marble, or aggregates thereof. Depending on the flooring material 22 selected, the tray 12 shape and dimensions may be adapted for proper structural integrity and aesthetic appeal. The flooring material 22 may be a solid color, pattern, or contain a grain or texture. The flooring material 22 may be a solid or contain a decoration, for example, a marble unit having glass covered cut away which houses a contrasting color wood. Various combinations of flooring materials 22 provide endless options for function and decoration.
Returning to FIG. 4 , the rubber matrix 20 provides a contact surface for the sub-floor 38 . The term “matrix” is used to represent a series of interconnected points and does not imply any particular geometry. As depicted, the rubber matrix 20 is a collection of intersecting lines forming a plurality of right angled structures. It is understood that the rubber matrix 20 may include any geometric or curved pattern or random pattern to provide a surface area for contact with the sub-floor 38 . The rubber matrix 20 may be of consistent dimensions or it may include regions 42 having an increased thickness or width. As depicted, the rubber matrix 20 includes a plurality of circular regions 42 at select line intersections. These regions 42 may be of any appropriate diameter or cross section depending on the particular shape selected. The regions 42 may include polygonal, circular or freeform shapes. The regions 42 may match in shape or may be a plurality of shape combinations and sizes. Additionally, the regions 42 may include depressed or raised sub-regions 44 . These sub-regions 44 may provide supplemental protection for the sub-floor 38 , allow for expansion or reduction of the selected materials 22 due to changes in temperature and provide structural support for the floor structure unit 10 . In various embodiments, the sub-regions 44 may be used as an alignment guide for a user. For example, in an embodiment combining circular and hexagonal regions 42 , the user may be instructed to align the components so that the hexagons are aligned with hexagons and the circles aligned with other circles. This may be particularly useful when applying a floor structure unit 10 of different colors or creating a pattern (such as a multi-level diamond, herringbone or zigzag) in the finished floor using a collection of floor structure units 10 .
The rubber matrix 20 may be made of any suitable rubber, including but not limited to natural rubber, cis-polyisoprene, polybutadiene, poly(styrene-butadiene), styrene-isoprene copolymers, isoprene-butadiene copolymers, styrene-isoprene-butadiene tripolymers, polychloroprene, chloro-isobutene-isoprene, nitrile-chloroprene, styrene-chloroprene, and poly (acrylonitrile-butadiene). Additives such as coloring agents, strength enhancing agents, or friction modifying agents may be added to the rubber.
Referring to FIGS. 7 a - c and 8 , the rubber grommet 24 is disposed about the perimeter of at least one retaining wall 40 of the tray 12 . The rubber grommet 24 advantageously provides support and impact cushioning in the lateral and longitudinal directions with respect to the tray 12 . This is particularly useful to prevent damaging of fragile flooring materials 22 when they are joined together. The grommet 24 resembles grout and grout joints because when the floor structure is assembled, the rubber grommet 24 engages a region of the flooring material 22 on an adjacent tile. Preferably, the rubber grommet 24 is sufficiently resilient to maintain its shape when a bare region of flooring material 22 is placed against the rubber grommet 24 , as detailed later herein.
As best depicted in FIGS. 4 and 7 c , the rubber grommet 24 and the rubber matrix 20 are a unitary piece. The region of the rubber grommet 24 surrounding the perimeter of the retaining walls 40 along the tray lower surface 28 forms an outer edge of the rubber matrix 20 . The monolithic matrix 20 and grommet 24 unexpectedly provides enhanced cushioning, absorption of footfall impact and noise, and eliminates shifting of the new floor because energy transfer is limited to between the rubber matrix 20 and rubber grommet 24 instead of to the floor structure unit 10 and flooring material 22 . Furthermore, the monolithic structure eliminates debris from reaching the sub-floor 28 . If any debris invades the flooring unit 10 , the debris is trapped between the region of the rubber grommet 24 surrounding the perimeter of the retaining walls 40 that forms the outer edge of the rubber matrix.
The rubber grommet 24 color may be of the same or different color(s) as the flooring material 22 or it may be an accent color entrained in a multi-colored flooring material 22 such as marble. The rubber grommet 24 may be made of the same rubber materials used for the rubber matrix 20 .
Between the voids in the rubber matrix 20 , an adhesive 36 may be applied. Suitable adhesives 36 include thermoplastic adhesives, thermosetting adhesives and rubber-resin blends. Specific examples of adhesives 36 include acrylic resin adhesive, cyanoacrylate adhesives, epoxy adhesives, phenolic adhesives, polyurethane adhesives, adhesives incorporating a dispersed, physically separated but chemically attached rubber phase, and mixtures thereof. Preferably, the adhesive 36 is a methacrylate-based adhesive. For example, a preferable adhesive 36 may comprise dodecyl methacrylate, hexadecyl methacrylate, poly(butadiene, methylmethacrylate and styrene), chlorosulfonated polyethylene, methacrylic acid and a methyl methacrylate monomer. Various factors including the particular flooring material 22 selected, the surface area covered by the rubber matrix 20 and the textured grid 34 of the tray 12 may be incorporated in the selection of the adhesive 36 .
The floor structure unit 10 is made by first providing a tray 12 having interlocking members 16 disposed thereon. The tray 12 may be made using injection molding. The details of the tray 12 including the textured grid 34 , interlocking members 16 , notches 30 and recessed segments 32 , may be constructed during a single injection molding step or a combination of steps such as an injection molding followed by pressing a form onto the tray 12 .
Placing the rubber grommet 24 and placing the rubber matrix 20 may be performed as distinct steps or a single step. In a preferred embodiment, the rubber matrix 20 is applied using double injection molding techniques and where the tray 12 materials and the rubber materials are injected into the same mold to form a single part. Double injection molding is preferred because the process may be designed to reduce assembly labor and may prevent defects in the flooring unit from improper orientation that may affect individual parts.
To place the new floor structure, the notches 30 on a first floor structure unit 10 are aligned with the contrapositive notches 30 or a second floor structure unit 10 . The notches 30 and recessed segments 32 may be engaged by pushing or snapping the units together. Manual pressure or a tool such as a hammer or mallet may be used to engage the interlocking members 16 . Preferably, the flooring units 10 are aligned such that the retaining walls 40 of one flooring unit 10 , engage bare flooring materials 22 of adjacent flooring units 10 . The process is repeated until the desired pattern or “floating” floor size is achieved. As stated above, the rubber grommet 24 is sufficiently resilient such that when the floor units 10 are engaged, the rubber grommet 24 serves as a cushion between edges of bare flooring material 22 . Preferably, the rubber grommet 24 is able to withstand the accumulation of pressure resultant from laying a plurality of flooring units 10 in various directions and combinations.
The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
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A floor structure unit, comprising: a tray, a flooring material, a rubber grommet, and a rubber matrix is provided. The tray includes an upper and lower horizontal surface, at least one retaining wall, a first and a second set of contrapositive interlocking members. The flooring material is disposed on the tray upper horizontal surface such that the first set of interlocking members is substantially flush with the flooring material and the second set of interlocking members extends beyond the flooring material. The rubber matrix is disposed in the tray lower horizontal surface, and the rubber grommet is disposed about the perimeter of the at least one retaining wall. The rubber grommet and the rubber matrix are a unitary piece. Methods of manufacture and use thereof are also provided.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] (not applicable)
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] (not applicable)
NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] (not applicable)
REFERENCE TO SEQUENCE LISTING, A TABLE OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX
[0004] (not applicable)
FIELD OF THE INVENTION
[0005] This invention relates to an apparatus for framelessly mounting and displaying flat artwork on a wall.
BACKGROUND OF THE INVENTION
[0006] In our digital age, it is becoming increasingly easier to create and duplicate flat artwork. Posters and photographs can be produced in a staggering variety of media, sizes and proportions, for comparatively little money.
[0007] The frames that display artwork are just as important a consideration. They are a design statement in their own right: thin, thick, with a matt, wood, plastic or metal. Furthermore, the material covering the artwork can determine how long it lasts—thin acetate on one end of the spectrum, and ultraviolet light-resistant, glare-free, museum quality glass on the other end. When you add up all of the materials that go into framing artwork, the frame and glass can often be more expensive than the artwork itself.
[0008] What to do, then, when one wants the artwork itself to be the statement? Until now, the options are museum putty, or sandwiching the artwork between two sheets of glass, a sheet of acetate and Masonite and clipping them together. Museum putty is quick, cheap and convenient, but stains paint and loses its adherence over time. Tacks and push pins also technically work, but they create holes, and are unsightly. For larger pictures, such as movie posters, the art often tears off the tacks, falling to the floor. Acetate and Masonite poster hanging kits are widely available in chain craft and hobby stores, but what if you can't find it in the right size? Two pieces of sheet glass look most professional, but where do you find the hardware to hold it together? And again, where can you have it custom made? What if there was a way to display flat artwork of any height and width on a wall without the expense and bother of frames, and with only simple tools?
BRIEF SUMMARY OF THE INVENTION
[0009] In accordance with one embodiment of the invention, I provide a snap-together, frameless mounting and display apparatus for displaying flat artwork. There are no frames and no borders surrounding the artwork. All the viewer sees is the artwork itself against the wall. The apparatus remains hidden behind the artwork. No tools are required to assemble the apparatus, and a common hammer and nails can mount it to the wall.
[0010] The apparatus comprises a flexible and transparent rectangular envelope which encloses the artwork, a rigid brace to stabilize the envelope in three dimensions, a wall mount into which the brace securely snaps, and, optionally, at least one extension bracket to push the artwork further away from the wall.
[0011] The rectangular envelope comprises a thin sheet of transparent polyethylene terephthalate glycol (PETG). The PETG can be glossy or matte. The envelope has an open configuration and a folded configuration. The envelope also has a right side and a wrong side. In the open configuration, the envelope is generally rectangular, with four edges, a top flap, a bottom flap, a left flap and a right flap defined by fold lines. The four fold lines together define an area within which the artwork is laid, enclosed and displayed. When the envelope is not in use, it is flexible enough to be rolled into a tube, from either the flat or the folded configuration.
[0012] Each corner of the open rectangle is cut off in an isosceles right triangle so that when each flap is folded on the fold line, the edges of the flaps meet perfectly mitered and form a similar, but smaller, rectangle matching a length and width dimension of the artwork to be displayed. The fold lines are scored only part way into the envelope, causing the flaps to only fold in one direction, toward the wrong side. In practice, the envelope is laid out in the open configuration and the flat artwork laid inside, the right side of the artwork facing the wrong side of the envelope and the wrong side of the artwork facing the user. The apparatus is optimally configured for flat artwork, such as those in sheet form like photographs, posters, or drawings on paper, paintings on canvas. The edges of the artwork are lined up with the fold lines and the flaps folded over to enclose those edges. Optionally, additional fold lines can be scored into the envelope to create options for enclosing and displaying thicker, multi-sheet artwork, such as covers of comic books or trade paperback books.
[0013] Each flap has a retention slot cut out at its midpoint, starting from the edge of the unfolded rectangle, running perpendicular to the edge and stopping short of the flap fold line. The piece of envelope remaining between the end of the retention slot and the fold line serves as a tab to rest on, position and stabilize the envelope within the brace.
[0014] In the embodiment shown in the drawings, the brace comprises a hub, four pairs of spaced-apart parallel rods snapped to the hub in one plane, radiating 90 degrees apart. It resembles a plus sign or a lowercase t. Each pair of spaced-apart parallel rods has an end that snaps into the hub, and an opposing end that snaps into a clip. It is important to use spaced-apart parallel rods, rather than a single rod, to brace the artwork. The pair of rods working in tandem prevents the artwork from twisting forward and backward in space. Each such clip in turn has space to receive and retain a corresponding envelope flap. The clip has a distinct front and back side, joined at a top and a bottom with bars. The slots and tabs on each flap of the envelope rest on the top bar, preventing vertical and horizontal motion. When all four edges of the envelope are inserted into the corresponding clips in this way, the envelope cannot move in any direction. It is not being pulled by tension, but rather, is simply held by the envelope perfectly fitting into the brace.
[0015] In a preferred embodiment, the hub itself is also generally shaped like a plus sign or lowercase “t,” comprising a central square, with coplanar rectangular extensions radiating away from each edge of the square. Each extension of the plus sign has a pair of spaced-apart rod retainer elements positioned within the extension and dimensioned to accept a corresponding pair of spaced-apart parallel rods. Each rod in the pair has a hub and a clip end. In the embodiment shown, the spaced-apart rod retainer elements are shaped like a C. The diameter of the C is the same as the diameter of the rod, so that the rod snaps tightly into place. The hub also has four pairs of stops integrated into the edge of the square and spaced distally from the extensions. These stops block the hub from sliding along the rods. In this way, the hub ends of the four pairs of parallel rods can be slid into the C-shaped rod retainer elements and up against the edge of the central square, thereby creating a larger plus sign shape.
[0016] The back of each clip also has two spaced-apart rows of three C-shaped rod retainer elements. The clip end of each rod can be slid through the three C-shaped rod retainer elements. A corresponding pair of stops distal to the three C-shaped rod retainer elements prevents each clip from sliding vertically down the pair of rods. The envelope flap inserts into the clip from above and between the front of the clip and the back of the clip. When the envelope slot is slid over the top bar, the tab in the envelope rests on the top bar and prevents the envelope from shifting vertically and horizontally. Not only does the bottom bar stabilize the clip, but it also rests on the wall mount. A plug projecting downward from the back of the clip further secures the clip to the wall mount.
[0017] The wall mount has a front facing surface and a back facing surface. The front facing surface of the wall mount notably has a pair of spaced-apart parallel slots centered between the pair of fastener positioning holes, dimensioned to receive the pair of rods of the brace. It is a close, but not snap-tight, fit. This allows the brace to rest within and atop the wall mount, then be easily lifted out. The front facing surface also has an integral groove cut thereinto which is dimensioned to receive the plug. In this way, the clip rests atop as well as within the wall mount. Mounted correctly, the brace is retained closely, though not loosely, within the wall mount. The plug fits into the groove, and the rods fit into the slots, securing the brace from shifting up and down, right and left, as well as forward and backward.
[0018] This same groove in the wall mount can also accommodate an optional forward extension bracket. The forward extension bracket allows the brace to be mounted forward of the wall. Thus, the brace can be either directly mounted against the wall, or alternatively, indirectly mounted to project forward in space. The front facing surface of the wall mount can only accept at any given time either a pair of parallel rods and plug, or a forward extension bracket, never both at the same time. In an alternative embodiment, the forward extension bracket can also connect the wall mount to the hub. In another alternative embodiment, a connector can slide up and down the spaced-apart pair of parallel rods and couple to the wall mount, allowing a user to vary the vertical positioning of the brace without moving the wall mount.
[0019] The back facing surface is flush to and can be permanently secured to a wall. The front facing surface of the wall mount has a pair of spaced-apart fastener positioning holes running through the entire wall mount from the front facing side to the back facing side. The fastener positioning holes accept nails, screws, anchors or similar permanent fastening device. The wall mount can also be affixed to the wall without using fasteners and holes, such as with an adhesive, such as Command® brand repositionable wall adhesive.
[0020] The forward extension bracket couples the clip of the brace to the front facing surface of the wall, and pushes the artwork forward into space relative to the wall, when a user wants the flat artwork to sit away from, and not directly against, the wall. To frame a piece of flat artwork, a user lays the flat artwork face down into the envelope in the unfolded configuration. It is important to align the edges of the artwork with the fold lines. The flaps are folded inward and over the edges of the artwork, thereby enclosing the artwork in the envelope. The user places the enclosed artwork front side down on a work surface, and lays the brace atop the back side of the artwork. He locates the notch in each flap and slides the notch over the bar of each clip. The brace thus holds the enclosed artwork flat, but not stretched. The brace-envelope assembly in this position can then be slid directly into the wall mount at any of four orientations, or into a forward extension bracket, which itself gets snapped into the wall mount.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0021] FIG. 1 is a perspective view of a frameless flat artwork mounting and display apparatus, being mounted on a wall
[0022] FIG. 2 is a perspective view of the frameless flat artwork mounting and display apparatus
[0023] FIG. 3 is a close-up perspective view of the frameless flat artwork mounting and display apparatus
[0024] FIG. 4A is a perspective view of an envelope in an open configuration
[0025] FIG. 4B is a perspective view of a front of the envelope in the folded configuration
[0026] FIG. 4C is a perspective view of a back of the envelope in the folded configuration
[0027] FIG. 4D is a perspective view of a front of the envelope in the folded configuration, and with artwork enclosed within
[0028] FIG. 5A is a rear view of a hub
[0029] FIG. 5B is a side view of the hub
[0030] FIG. 5C is a front view of the hub
[0031] FIG. 6 is a close-up perspective view of the frameless flat artwork and display apparatus
[0032] FIG. 7A is a perspective view of a clip
[0033] FIG. 7B is a front view of the clip
[0034] FIG. 7C is a bottom view of the clip
[0035] FIG. 7D is a side view of the clip
[0036] FIG. 8A is a perspective view of a wall mount
[0037] FIG. 8B is a front view of the wall mount
[0038] FIG. 8C is a bottom view of the wall mount
[0039] FIG. 8D is a side view of the wall mount
[0040] FIG. 9 is a close-up perspective view of the frameless flat artwork and display apparatus as coupled to the wall mount with three extension brackets
[0041] FIG. 10A is a perspective view of one such extension bracket
[0042] FIG. 10B is a top view of the extension bracket
[0043] FIG. 10C is a front view of the extension bracket
[0044] FIG. 10D is a side view of the extension bracket
REFERENCE NUMERALS
[0000]
1 Frameless flat artwork mounting and display apparatus
10 Envelope
11 Fold lines
12 Flaps
13 Retention slot
14 Tab
20 Brace
21 Hub
22 Central square
23 Extensions
24 C-shaped retainer elements, hub
25 Stops
26 Pair of parallel rods
27 Hub end of rod
28 Clip end of rod
30 Clip
31 Front of clip
32 Back of clip
33 Top bar
34 Bottom bar
35 C-shaped retainer elements, clip
36 Stopper end
37 Plug
40 Wall mount
41 Front-facing side
42 Fastener positioning holes
43 Slots
44 Groove
45 Back-facing side
50 Forward extension bracket
51 Male element
52 Female element
DETAILED DESCRIPTION OF THE INVENTION
[0077] FIG. 1 shows an overview of one embodiment of a frameless flat artwork mounting and display apparatus 1 . An envelope 10 wraps around and partially encloses a piece of flat artwork (right side not shown in this view). A brace 20 stabilizes the artwork within the envelope 10 . A wall mount 40 is permanently affixed to a wall. The brace 20 is set into the wall mount and displays the right side of the artwork to a viewer.
[0078] The envelope 10 is preferably transparent and colorless. Preferably, the envelope is made of polyethylene terephthalate glycol (PETG), because this material is thin, heat resistant to 150 F, malleable, rollable and holds a crease without cracking. The PETG can have a glossy or a matte finish. Preferably, the PETG envelope is 0.010 inch thick, although other thicknesses having the above properties are also within the scope of this invention. FIG. 4A shows additional details about the envelope.
[0079] FIG. 4A-4D shows the envelope 10 in more detail. Envelope 10 has an open configuration and a folded configuration, a front, and a back. FIG. 4A shows the back of envelope 10 in the open configuration. In FIG. 4A , envelope 10 is a rectangle of unequal sides, although a square could also be used. The dimensions of the rectangular or square envelope can be varied by those of ordinary skill in the art to accommodate flat artwork of a particular length and width. The envelope 10 in the open configuration has four edges and an isosceles right triangle cut off of each corner. Fold lines 11 are scored into the truncated rectangle equidistant to each edge of the rectangle. The area between the edge of the rectangle and a corresponding fold line 11 defines a flap 12 . Note four such flaps 12 identified in FIG. 4A . In the embodiment illustrated, one set of four fold lines 11 is shown. The artwork rests atop and fills an area within and defined by the one set of fold lines. The dimensions of this area can also be varied by those of ordinary skill in the art to fit a particular size of artwork.
[0080] One such set of fold lines can enclose and accommodate a sheet of artwork, such as a drawing, photograph or a poster. In an alternative embodiment, not shown, a second set of fold lines can be scored into the envelope equidistant and perpendicular to and within the area defined by the first one set of fold lines. The second set of fold lines defines a flap that can fold twice. Such a bi-fold flap can neatly enclose and securely display within the apparatus relatively thicker pieces of artwork, such as comic books and trade paperback books. A slot 13 is cut at the midpoint of each flap perpendicular to and from the edge of the rectangle, toward but not all the way to the fold line 11 . Tab 14 is a segment of envelope remaining between and end of the slot and the fold line 11 .
[0081] FIG. 4B shows the front of an empty envelope 10 in the folded configuration. Phantom lines show how the four flaps 12 have been folded back at the fold lines 11 to meet perfectly mitered at the back of the envelope. FIG. 4C shows the back of an envelope in the folded configuration. FIG. 4D shows the front of the envelope in the folded configuration enclosing a rectangular piece of artwork. The edges of the artwork are congruent with the fold lines, thus fill the envelope in the folded configuration. The flaps fold behind the artwork and cannot be seen.
[0082] FIG. 2 shows brace 20 in more detail. Artwork is not shown here, for clarity and simplicity. A back view of the brace 20 is shown here holding an envelope 10 in the folded configuration. Brace 20 comprises a hub 21 and four pairs of parallel rods 26 radiating therefrom 90 degrees from each other. Each pair of parallel rods 26 snaps into the hub at one end and, at an opposing end, snaps into to a clip 30 . Each clip 30 in turn retains a midpoint of one flap of the envelope 10 . In this way, the artwork is held taut, notably not by tension, but rather by the envelope fitting perfectly into the brace. Preferably, the hub 21 and clips 30 are injection molded from 10% glass-filled polypropylene (GFPP). This blend is stronger than pure polypropylene, but flexible enough to allow the hub and into the clip to bend slightly while the pair of parallel rods is snapped thereinto, without the hub and clip breaking. Other compounds can be used to make the hub 21 and clips 30 as long as they are both strong and flexible.
[0083] In the embodiment shown, the hub is 2.6 inches across in its largest dimension, but other dimensions can be created without undue experimentation by those of ordinary skill in the art, without deviating from the scope of this invention. In the embodiment shown, the clip is 1.743 inches wide, 1.48 inches tall and 0.400 deep, but again, these dimensions can be varied by someone of ordinary skill in the art.
[0084] Each rod in the pair of parallel rods 26 is made preferably from 30% GFPP, although a nylon plastic blend can also be used. The advantage of GFPP is that it is stronger than pure plastic, and has a matte texture which increases static cling friction with the wrong side of the flat artwork. Preferably, each rod in the pair of parallel rods has a diameter of 0.232 inch, but other dimensions can be used and still be within the scope of this invention. The length of the rods can be varied and customized to accommodate the length and width of a particular artwork.
[0085] FIG. 3 shows the brace in more detail, in particular, how each pair of spaced-apart parallel rods snaps into both the hub 21 and, at an opposing end, into a clip 30 . On the back of both the hub 21 and clip 30 can be found a pair of C-shaped rod retainer elements 24 and 35 , respectively. A hub end of each rod is snapped into the C-shaped rod retainer elements 24 on the hub. A clip end of each rod is snapped tightly into the C-shaped rod retainer elements 35 on the front of the clip. These C-shaped rod retainer elements prevent the rod from shifting outside the retainer. The C shapes have an interior diameter equal to the diameter of the rod, so that the retainer element securely holds the rod when it is snapped in. Each pair of rod retainer elements 24 , 35 on both the hub and on the front of the clip, respectively, are spaced apart the same distance on both the hub 21 and the front of the clip 30 so that when a pair of rods is snapped therein, the rods are tightly held parallel to each other. The space between the rods can be varied by one of ordinary skill in the art. In the embodiment shown, the distance is approximately 1 inch. An advantage of bracing the artwork with pairs of spaced-apart parallel rods, is that it prevents the artwork from twisting in place. Prior art braces have only single rods or spokes, and are prone to twisting. Note also stops 25 integrated into the hub and stops 36 integrated into the clip. These stops prevent the hub and clip, respectively, from sliding up and down the rods.
[0086] Details of the hub 21 are shown in FIGS. 5A, 5B and 5C . In a preferred embodiment, shown here, the hub is shaped like a plus sign, comprising a central square 22 and a coplanar extension 23 radiating from each side of the square. However, other hub shapes are entirely possible and within the scope of this invention. FIG. 5A presents a view of the back. Seen more clearly in FIG. 5A are the stops 25 that prevent the hub from sliding along the pair of spaced-apart parallel rods. A rod is snapped into a C-shaped rod retainer element 24 such that the hub end 27 of the rod abuts a corresponding stop 25 . This is repeated for all eight rods in this embodiment.
[0087] FIGS. 7A, 7B, 7C and 7D show the clip in more detail. Notably, the clip has a planar front 31 , which is parallel to the plane of a back 32 . The front and the back of the clip are joined by a top bar 33 and a bottom bar 34 , creating a space therebetween. The top bar 33 and the bottom bar 34 each have a width. Extending forward from the back of the clip and into this space are two sets of rod retainer elements 35 . In the embodiment shown, each set rod of retainer element has a three C-shaped projections. Other similar means of securely but releasably coupling the rods to the clip are possible and within the scope of this invention. Note particularly in FIG. 7D stop 36 . There are a pair of stops 36 on each clip, which prevents the clip from sliding along the pair of spaced-apart parallel rods. Top bar 33 and bottom bar 34 each have two purposes. They join the front and the back of the clip and prevent twisting. Top bar 33 also positions the envelope flap 12 upon the clip. The width of top bar 33 is the same as slot 13 so that the tab 14 of envelope flap 12 rests thereupon. In this position, the envelope flap 12 stays in one position. Note also that the bottom bar 34 rests upon wall mount 40 , further preventing the apparatus from shifting in place. Please see FIG. 6 . Lastly, projecting downward from the back of the clip in roughly the same plane is a plug 37 . The plug fits into both the wall mount and also into a female element of a forward extension bracket, to be discussed in more detail later.
[0088] In FIG. 6 , one can see in detail how the envelope is attached to the clip. Slot 13 is slid over top bar 33 so that tab 14 (not shown) rests thereupon. Flap 12 rests in the space between the front and the back of the clip. The area of the envelope within the four fold lines sits in front of the front of the clip. In other words, the clip is sandwiched between the front of the envelope and each flap. If opaque artwork is enclosed within the envelope, the clips would be hidden behind the artwork.
[0089] FIGS. 8A, 8B, 8C and 8D show the wall mount 40 in greater detail. Wall mount 40 has a front-facing side 41 and a back-facing side 45 . From the front-facing side is cut a pair of spaced-apart slots 43 . These slots are where the pair of spaced-apart rods lay. Thus, the wall mount supports the brace in part by the pair of parallel rods. Preferably, the wall mount is molded from 30% GFPP, although other materials which perform similarly may also be used.
[0090] In the embodiment shown, the slots are spaced 1 inch apart, but this can be varied by someone of ordinary skill of the art without departing from the spirit of this invention. The portion of the front-facing side between the slots projects frontward in space and supports the bottom bar 34 of the clip. The wall mount therefore supports and stabilizes the apparatus in two ways—by the bottom bar resting atop the projection and by the plug fitting into the groove. Fastener positioning holes 42 run through the entire wall mount 40 and permanently secure the wall mount to a wall. One can use nails, screws or anchors, or any other permanent fastener known to those of ordinary skill in the art. Alternatively, one can secure the wall mount to the wall without fastener, such as with permanent or temporary adhesive.
[0091] FIG. 9 depicts an alternative embodiment of this invention, where the brace 20 is not laid directly into the wall mount 40 , but rather is coupled indirectly to the wall mount with at least one forward extension bracket 50 there between. In the embodiment shown, three forward extension brackets are used. These brackets push the brace 20 further forward from the wall. As shown in more detail in FIGS. 10A, 10B, 10C and 10D , each forward extension bracket has two male elements and two female elements 52 . Preferably the wall mount is injection molded from a 30% GFPP blend although other materials which perform similarly may also be used.
[0092] To connect the brace 20 to the wall mount, a first male element 51 slides into groove 44 . The second male element 51 slides into and supports either a first female element 52 of another forward extension bracket, as shown in FIG. 9 , or in front of plug 37 . Plug 37 is congruent with male element 51 such that both the plug and the male element can interlock with the female element at any given time. In the embodiment shown, the forward extension bracket 50 is shaped like a letter N, but other shapes and configurations enabling the male elements to interlock completely within its own female elements and also the groove are also within the scope of this invention.
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I disclose a frameless display apparatus for flat or essentially flat artwork. The apparatus comprises a transparent envelope with flaps to fold around the edges of the flat artwork. Four perpendicular pairs of rods meet at a hub to create a T-shaped cross brace. Clips on the terminal ends of each pair of rods couple to the edges of the enclosed artwork to stabilize the artwork from twisting in place. The artwork and cross brace rest directly in a wall mount, or spaced forward of the wall with one or more interlocking forward extension elements.
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BACKGROUND OF THE INVENTION
The present invention relates to an ammunition feed system for a small or medium caliber fire arm, of the type comprising at least one ammunition storage device, a loading device belonging to the weapon to load the munitions one by one into a firing chamber, and an intermediate device to transfer the munitions from the storage device to the loading device of the weapon.
In a conventional feed system, the munitions are chain-linked together on a conveyor chain which is stored in a container forming an ammunition rack. The intermediate transfer device between the rack and the loading device of the weapon includes a one-way drive that meshes with the chain to bring the munitions up to the loading device of the weapon.
As a general rule, a fire arm can fire different munitions which are selected according to the nature of the target to be hit. In practice, a target which appears within the aiming range of the weapon is not always identifiable in advance, given that the effectiveness of the fire is conditioned by a suitable choice of the munition to be fired. To solve this problem, one solution consists in providing two ammunition racks containing different munitions. These two racks are placed on either side of the weapon and work respectively with two intermediate devices which transfer the munitions from one or the other of the racks up to the loading device of the weapon.
Such a solution is not satisfactory technically and it has the notable disadvantage of being cumbersome.
SUMMARY OF THE INVENTION
One aim of the invention is to bring a new solution to the problem explained above whilst procuring other advantages.
To this end, the invention proposes a feed system of the afore-mentioned type which is characterised in that the storage device includes a single container in which two ammunition racks have been arranged each containing different munitions which are not necessarily chain-linked together. Each rack includes a two-way conveyor which supports and moves the munitions inside the rack. The intermediate transfer device also comprises a two-way transport device common to the two racks and designed either to transfer the munitions from one or the other of the racks towards the loading device of the weapon, or to bring back to their original rack those munitions which are in the process of being transferred towards the loading device of the weapon. The feed system also comprises structure to select and control the two-way transport device of the intermediate transfer device simultaneously with one or the other of the conveyors of the two racks.
According to a preferred embodiment of the invention, the two-way transport device of the intermediate transfer device may include a starwheel, and the conveyor of each rack may be an endless chain conveyor.
According to another characteristic of the invention, the structure to select and control the starwheel simultaneously with one or the other of the conveyors of the two racks, may include a drive wheel integral in rotation with the shaft supporting the starwheel having two drive wheels working respectively with the two conveyors via two coupling devices. The drive wheel may also include a single control device to act on the two coupling devices in such a manner as to mesh the drive wheel of the starwheel with one or the other of the drive wheels of the two conveyors.
As a general rule, the starwheel is rotated in one or the other direction either by an auxiliary driving source, or by the driving source used to ensure the operation of the weapon.
According to a significant advantage of the invention, the feed system enables the transfer of the munitions between the weapon and the two racks to be carried out in a manner which is absolutely reversible according to the rotational direction of the starwheel.
According to a further advantage of the invention, the feed system is particularly well adapted for the transfer of telescoped munitions.
BRIEF DESCRIPTION OF THE DRAWINGS
Other advantages, characteristics and details of the invention will become apparent from the following explanatory description made with reference to the appended drawings, given merely by way of illustration, wherein:
FIG. 1 is a partial skeleton view in perspective of a double ammunition rack for the feed system according to the invention;
FIG. 2 is a view according to the arrow II in FIG. 1 to illustrate the operation of the rack;
FIG. 3 is a partial skeleton view of a conveyer housed in one of the racks of the feed system;
FIG. 4 is a partial perspective view of the part of FIG. 3 indicated by the arrow IV;
FIG. 5 is a similar view to that of FIG. 2 to illustrate the operation of the other racks; and
FIG. 6 is a partial perspective view of a detail of FIG. 1 indicated by arrow VI.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The feed system 1 shown in FIGS. 1, 2 and 5 comprises a storage device 3 for different munitions M1 and M2, a loading device 5 to introduce the munitions one by one in a loading and firing chamber 6 of a small or medium caliber fire arm 7, and an intermediate device 9 to transfer the munitions M1 and M2 between the storage device 3 and the loading device 5 of the weapon 7.
The representation of the loading device 5 of the weapon has been voluntarily given in skeleton form, given that it is peculiar to the type of weapon under consideration and that the storage device 3 and the intermediate transfer device 9, form an assembly which may work with different types of loading devices.
The storage device 3 given in FIG. 1 comprises a container 10 in the shape of a parallelepiped rectangle. Two racks G1 and G2 containing the munitions M1 and M2 are arranged inside the container 10.
The two racks G1 and G2 are arranged on either side of a central vertical partition 12 which longitudinally separates the inner volume of the container 10 into two parts. The container 10 extends for a length which is greater than that of the munitions M1 and M2.
Two vertical passages, respectively outer 15 and inner 17, are demarcated in each rack G1 and G2 by means of an intermediate vertical wall 19 parallel to the central partition 12.
More specifically, for the rack G1 for example:
the outer passage 15 is demarcated between the longitudinal vertical wall 10a of the container 10 which surrounds the rack G1 and the intermediate vertical wall 19 of this rack G1, and
the inner passage 17 is demarcated between the intermediate vertical wall 19 of the rack G1 and the central vertical wall 12 which separates the two racks G1 and G2.
The two passages 15 and 17 of the rack G1 are of a width which is slightly greater than the diameter of the munitions which they must store. At their lower ends, the two passages 15 and 17 communicate with each other by a semi-circular part 20 arranged in the bottom wall of the container 10. At their upper ends, the two passages 15 and 17 open out into a same entrance/exit 22 arranged on the upper part of the container 10.
Rack G2 is arranged in an identical manner to rack G1, and the two outer 15 and inner 17 passages of rack G2 also open out, at their upper ends, in the same entrance/exit 22 as those of rack G1.
The munitions M1 and M2 are designed to be stored horizontally on top of each other in the passages 15 and 17 of the two racks G1 and G2, the munitions not being chain-linked together.
Each rack G1 and G2 is fitted with a two-way transport means to support and move the munitions M1 and M2 inside the rack.
In the example of an embodiment illustrated on the different figures, the two-way transport means includes a conveyor 25 having two endless chains 27. The two chains 27 of each conveyor 25 extend in parallel to one another and each winds around, respectively, upper 29 and lower 31 drive wheels. The drive wheels 29 and 31 share each chain 27 in two bits and are arranged so that each bit of the chain 27 may freely move in the outer passage 15 of the relevant rack G1 or G2, whereas the other bit of the chain 27 may freely move in the inner passage 17 of the rack G1 or G2. The two upper drive wheels 29 of the two chains 27 are supported by and are integral in rotation with the same shaft 29a, and the two lower drive wheels 31 are also supported by and integral with a common shaft 31a, so that the two chains 27 of each conveyor 25 are driven simultaneously. The ends of the shafts 29a and 31a of each conveyor 25 are housed in bearings 33 supported by the side wall of the container 10, for example.
The two endless chains 27 of each conveyor 25 comprise radial catches 35 which are designed to support the munition M1 or M2.
The intermediate device 9 to transfer the munitions from one of the racks G1 or G2 towards the loading device 5 of the weapon and vice versa also comprises a two-way transport means which includes a starwheel 37.
The starwheel 37 comprises two stars with four points that are supported by and integral in rotation with a bearing shaft 41. The two stars 39 are separated from one another by a distance which is less than the length of the munitions M1 and M2 so as to support the munitions.
The starwheel 37 is mounted in the upper entrance/exit opening 22 of the container 10 to work with the munitions of racks G1 or G2. The shaft 41 carrying the starwheel 37 is supported in rotation by the container 10 and extends in parallel to the shafts 29a and 31a of the two conveyors 25.
The entrance/exit opening 22 of the container 10 is partly bordered by a casing 43 having the shape of the arc of a circle which partly surrounds the starwheel 37 on the rack G1 side. It is notable that the distance separating the bottom of each point 40 of the stars 39 and the inner wall of the casing 43 is barely greater than the diameter of the munitions M1 and M2.
The starwheel 37 and the conveyors 25 must be controlled simultaneously, knowing that in operation one or other of the racks G1 or G2 is selected.
Means to select and control the starwheel 37 simultaneously with one or other of the conveyors 25 of the two racks G1 or G2 have been provided.
The means comprises at least:
one drive wheel 45 supported by and integral with the shaft 41 of the starwheel 37,
one drive wheel 47 connected in rotation with the shaft 29a of the conveyor 25 of rack G1 and mobile in translation on the shaft 29a by means of a coupling device 48 that may or may not mesh the drive wheel 47 with the drive wheel 45 of the starwheel 37,
one drive wheel 49 connected in rotation with the shaft 29a of the conveyor 25 of rack G2 and mobile in translation on the shaft 29a by means of a coupling device 50 that may or may not mesh the drive wheel 49 with the drive wheel 45 of the starwheel 37, and
a single control device 52 which acts on the two coupling devices 48 and 50 so that the drive wheel 45 of the starwheel is neither meshed with one or other of the drive wheels 47 and 49 of the two conveyors 25.
The two coupling devices 48 and 50 are identical and only device 48 is described hereafter.
The coupling device 48 comprises a bush 54 which is mounted sliding on the shaft 29a of the conveyor 25 of rack G1 by means of ribbing 56. The drive wheel 47 is supported by and integral with the bush 54.
The control device 52 comprises a rod 58 tipped at each end by a fork 60 which engages in a ring-shaped groove 62 arranged on the periphery of each bush 54. The rod 58 is mounted on a pivot 65 to move in translation the two bushes 54 in two different directions. In this manner, when the drive wheel 47 of the conveyor 25 of rack G1 meshes with the drive wheel 45 of the starwheel 37, the drive wheel 49 of the conveyor 25 of rack G2 is not meshed with the drive wheel 45 of the starwheel 37, and vice versa. In these circumstances, when the starwheel 37 rotates, only one of the conveyors 25 is driven simultaneously with the rotational movement of the starwheel 37.
Lastly, with reference to FIG. 6, a swivelling guiding flap 70 is located at the entrance/exit opening 22 of the container 10. The flap 70 is positioned under the starwheel 37 and is integral with a shaft 72 which extends in parallel to the shaft 41 of the starwheel 37. The shaft 72 is supported in rotation by the container 10. The flap 70 extends for a length which is less than the distance separating the two stars 39, and may swivel between two positions according to whether rack G1 or G2 is selected. In each of these two positions, the flap 70 is immobilized by at least one ball bearing tappet 74, for example. To this end, the shaft 72 integral with the flap 70 supports a radial lever 76, towards one end, which is designed to work with two ball bearing tappets 74 supported by a wall of the container.
The operation of the feed system will now be described.
In the first place, the munitions M1 are stored in rack G1 and the munition M2 are stored in rack G2. Each rack G1 and G2 is fitted with a trap door (not shown) to load the munitions into the vertical passages respectively outer 15 and inner 17 of each rack G1 and G2. In each passage, a munition M1 or M2 is supported by two catches 35 of the two endless chains 27 of the relevant conveyor 25.
When the weapon is operational, the firer may select rack G1 or rack G2 according to the type of target to be hit. If the firer selects rack G2 to fire munition M2 and the drive wheel 49 of the conveyor 25 of the rack G2 is not meshed with the drive wheel 45 of the starwheel, the firer acts on the control device 52 to mesh the two drive wheels 45 and 49 by swivelling the rod 58. This causes the drive wheel 47 to uncouple from the conveyor 25 of rack G1 and the drive wheel 45 to uncouple from the starwheel 37.
The shaft 41 of the starwheel 37 is controlled in rotation, to drive the conveyor 25 of rack G2 simultaneously with the shaft 41. With reference to FIG. 2, the munitions M2 contained in the outer passage 15 or the exit passage of rack G2 rise and are transported one after the other to the entrance/exit opening 22 in order to be picked up by the points 40 of the starwheel 37 and transferred towards the chamber 6 of the loading device 5 at the firing rate of the weapon. The first munition M2 which exits from the rack G2 puts pressure on one face of the flap 70 to make it swing. The swing of the flap 70 is limited by the ball-bearing tappet 74 located at the side of rack G1. The flap 70 thus enables the munition M2 to be held back, the munition thereafter finds itself under the starwheel 37. The munition M2 partly engages between two axially aligned points 40 of the two stars 39 of the starwheel 37 and is then guided by the casing 43 until the munition M2 moves into the upper part of the starwheel 37 before being ejected towards the loading device 5 of the weapon and loaded in the chamber 6.
At the same time, the munitions M2 contained in the inner passage 17 of rack G2 move down in order to pass into the outer passage 15 with constitutes the exit passage of rack G2.
The rotational movement of the starwheel 37 is controlled by the operational cycle of the weapon. The rotational movement is therefore not continuous, as this movement must be momentarily interrupted during the firing phase of the munition loaded in the chamber 6 of the weapon 7.
When the firer has decided to cease firing munition M2 in order to fire munitions M1, he must firstly bring back the munitions M2 which are possibly in the process of being transferred towards the loading device 5 of the weapon. In order to do that, the firer controls the shaft 41 of the starwheel 37 by rotating it in the opposite direction to bring the munitions M2 back to rack G2.
Afterwards, to select rack G1, the firer acts on the control device 52 to simultaneously drive the starwheel 37 and the conveyor 25 of rack G1, i.e. to couple the drive wheel 45 of the starwheel 37 and the drive wheel 47 of the conveyor 25 of rack G1. Finally, the firer activates the rotation of the shaft 41 of the starwheel 37 to drive the conveyor 25 of rack G1. The munitions M1 rise and exit rack G1 by the inner passage 17, whereas the munitions M1 of the outer passage 15 move down and thereafter pass into the inner passage 17 or exit passage. The first munition M1 which exits from rack G1 pushes the flap 70 and makes it swing towards its other position where it is immobilized by the ball-bearing tappet 74 located at the side of rack G2. As above, the casing 43 enables the munitions M1 to be guided between the lower and the upper parts of the starwheel 37.
When rack G1 is selected, the flap 70 merely functions as a guide for the munitions M1. In fact, the inner passage 17 of rack G1, which acts as an exit passage, is located roughly opposite the starwheel 37. On the other hand, when rack G2 is selected, the flap 70 functions as a support to hold back the munitions M2 Given that the outer passage 15 of exit passage is axially offset with respect to the starwheel 37.
The reversible operation of the starwheel 37 supposes that its position and dimensions, in particular of the points 40 of the stars 39 as well as the shape of these points, are precisely calculated according to the diameter of the munitions M1 and M2 on the one hand, and take into account the fact that the munitions M1 of rack G1 exit via the inner passage 17, whereas the munitions M2 of rack G2 exit via the outer passage 15.
The invention is naturally not limited to the embodiment described above. In particular, the means to select rack G1 or G2 and the means to simultaneously control the starwheel 37 with the conveyor 25 of the selected rack may by replaced by means which are their technical equivalent.
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An ammunition feed system for a small or medium caliber fire arm, of the type comprising a double ammunition rack (G1, G2) for different munitions (M1, M2), a loading device belonging to the weapon to load the munition one by one and an intermediate (9) device to transfer the munitions (M1, M2) from the rack (G1 or G2) towards the loading device. Each rack (G1, G2) comprises a conveyor (25) having two endless chains (27) which is selectively coupled to a starwheel (37) which forms the intermediate transfer device (9). This wheel may revolve in two opposite direction in order to extract the munitions (M1, M2) from one rack (G1, G2) or to bring the munitions (M1, M2) back to the original rack.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 14/188,930 filed Feb. 25, 2014, which is a continuation of U.S. patent application Ser. No. 12/607,146 filed Oct. 28, 2009, which claims priority from Korean Patent Application No. 10-2009-0021271, filed Mar. 12, 2009, in the Korean Intellectual Property Office. The disclosures of these applications are incorporated herein by reference in their entireties.
BACKGROUND
[0002] 1. Field
[0003] Apparatuses consistent with the exemplary embodiment relate to transferring signals, and more particularly, to a signal transfer apparatus which transfers a plurality of signals output from an electronic device to another electronic device.
[0004] 2. Description of the Related Art
[0005] Image signals or audio signals output from an electronic device need to be transferred to another electronic device to operate the electronic devices in association with each other. For example, image signals are transferred from a digital versatile disk (DVD) player or a set-top box to a television (TV) to reproduce the image signals. When an image signal is transferred as a component type, three component signals including a luminance signal Y and color difference signals Pb and Pr are transmitted to a TV, which includes terminals to receive such signals. There are various signal transfer methods other than a component type such as a composite type, and thus a TV should include various terminals to receive signals transferred in various manners.
[0006] Recently, there have been many efforts to miniaturize electronic devices. For example, it may be necessary to miniaturize an electronic device to fabricate electronic devices such as a thin wall-mounted TV. For the miniaturized electronic devices, the size and number of terminals to transmit and receive signals to and from another electronic device need to be reduced.
[0007] Additionally, the terminals are typically disposed on a rear surface of the electronic device. Electronic devices such as a wall-mounted TV are fixedly mounted on a wall. The wall-mounted TV includes cables to transfer audio signals or image signals and connectors to connect the wall-mounted TV to external devices, and these cables and connectors may make it difficult to closely attach the wall-mounted TV to the wall. Accordingly, there is a need for a connector that facilitates close attachment of the wall-mounted TV to a wall.
SUMMARY
[0008] Exemplary embodiments address at least the above problems and/or disadvantages and other disadvantages not described above. Also, the exemplary embodiments are not required to overcome the disadvantages described above, and may not overcome any of the problems described above.
[0009] One or more exemplary embodiments provide a signal transfer apparatus to reduce the size and number of terminals of an electronic device.
[0010] According to an aspect of an exemplary embodiment, there is provided a signal transfer apparatus, including a plurality of input connectors to which a plurality of signals are input; and a single output connector which is connected to the plurality of input connectors and outputs the plurality of signals.
[0011] The length of a plurality of cables connecting the single output connector and the plurality of input connectors may differ from each other so that the plurality of input connectors do not overlap each other.
[0012] The single output connector may include an output terminal which is connected to the second electronic device; wherein the output terminal may include a plurality of signal regions which are connected to the plurality of signals input to the plurality of input connectors, respectively; and a ground region which is connected to grounds of the plurality of input connectors.
[0013] The plurality of signal regions and the ground region may be formed lengthwise along the single output terminal.
[0014] An insulating material may be disposed between the plurality of signal regions and the ground region.
[0015] The output terminal may be formed in a pin shape.
[0016] The plurality of input connectors may include a first input connector to which a luminance signal Y is input; a second input connector to which a first color difference signal Pb is input; and a third input connector to which a second color difference signal Pr is input.
[0017] The length of the plurality of cables connecting the single output connector and the first, second, and third input connectors may differ from each other.
[0018] The single output connector may include an output terminal which is connected to the second electronic device; a first signal region which is connected to the luminance signal Y; a second signal region which is connected to the first color difference signal Pb; a third signal region which is connected to the second color difference signal Pr; and a ground region which is connected to grounds of the first, second, and third input connectors.
[0019] The first, second, and third signal regions and the ground region may be formed lengthwise along the output terminal.
[0020] An insulating material may be disposed between the first, second, and third signal regions and the ground region.
[0021] The plurality of input connectors may be connected to external cables.
[0022] The plurality of input connectors may be formed as a female connector.
[0023] The plurality of signals may include at least one image signal.
[0024] The second electronic device may be a television (TV).
[0025] The TV may include a terminal into which the output connector is inserted.
[0026] The inserting direction of the output connector may be parallel with a display plane of the TV.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The above and other aspects will be more apparent by describing certain exemplary embodiments with reference to the accompanying drawings, in which:
[0028] FIG. 1 is a schematic view of a signal transfer apparatus according to an exemplary embodiment;
[0029] FIG. 2 is a schematic view of the signal transfer apparatus of FIG. 1 coupled to an electronic device; and
[0030] FIG. 3 is a circuit diagram of the signal transfer apparatus of FIG. 1 .
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0031] Exemplary embodiments are described in greater detail with reference to the accompanying drawings.
[0032] In the following description, like drawing reference numerals are used for like elements, even in different drawings. The matters defined in the description, such as detailed construction and elements, are provided to assist in a comprehensive understanding of the invention. However, it is apparent that the present invention can be practiced without those specifically defined matters. Also, well-known functions or constructions are not described in detail since they would obscure the invention with unnecessary detail.
[0033] An exemplary embodiment relates to a signal transfer apparatus which transfers a plurality of signals from a first electronic device to a second electronic device. In this exemplary embodiment, a signal transfer apparatus transfers a plurality of image signals output from a digital versatile disk (DVD) player or a set-top box corresponding to the first electronic device to a TV corresponding to the second electronic device in a component type signal transfer. However, embodiments are not limited to these electronic devices. In addition, embodiments may also be used to transfer audio signals or other signals other than image signals.
[0034] FIG. 1 is a schematic view of a signal transfer apparatus 100 according to an exemplary embodiment, FIG. 2 is a schematic view in which the signal transfer apparatus 100 of FIG. 1 is coupled to an electronic device (TV 200 ), and FIG. 3 is a circuit diagram of the signal transfer apparatus 100 of FIG. 1 .
[0035] The signal transfer apparatus 100 according to an exemplary embodiment includes a plurality of input connectors 110 a , 110 b , 110 c , a single output connector 120 , and a plurality of cables 130 a , 130 b , 130 c.
[0036] A plurality of signals output from the first electronic device, such as a DVD player or a set-top box, is input to the plurality of input connectors 110 a , 110 b , 110 c . The image signals are transferred as a component type in this exemplary embodiment. The signal transfer apparatus 100 includes the first input connector 110 a to which a luminance signal Y is input, the second connector 110 b to which a first color difference signal Pb is input, and the third connector 110 c to which a second color difference signal Pr is input. Referring to FIG. 2 , the first electronic device (not shown) is connected to the plurality of input connectors 110 a , 110 b , 110 c through external cables 111 a , 111 b , 111 c , and the second electronic device (TV) 200 is connected to the output connector 120 .
[0037] Because three component signals Y, Pb, Pr are transferred in this exemplary embodiment, three input connectors 110 a , 110 b , 110 c are used. However, the number of input connectors is not limited thereto, and, if the number of signals to be transferred is increased or reduced, more or less input connectors may be used.
[0038] The single output connector 120 is connected to all the input connectors 110 a , 110 b , 110 c , and transfers the plurality of signals to the second electronic device, such as the TV 200 . The number of input connectors 110 a , 110 b , 110 c is plural, but only one output connector 120 is provided as shown in FIGS. 1 and 2 . As described in detail below, the output connector 120 includes a plurality of signal regions 122 a , 122 b , 122 c which are respectively connected to the cables 130 a , 130 b , 130 c and receive the signals input to the input connectors 110 a , 110 b , 110 c via the cables 130 a , 130 b , 130 c . Accordingly, in the exemplary embodiment, a single output connector 120 is used to transfer the plurality of signals.
[0039] Therefore, the TV 200 includes only one terminal 201 to receive the luminance signal Y and the first and second color difference signals Pb, Pr from the output connector 120 , as shown in FIG. 2 . Because the TV 200 according to the exemplary embodiment requires a lesser number of terminals, e.g., only one terminal 201 , the TV 200 may be miniaturized and/or slimmer.
[0040] The cables 130 a , 130 b , 130 c connects the single output connector 120 to the input connectors 110 a , 110 b , 110 c . Referring to FIG. 1 , the length of each of the cables 130 a , 130 b , 130 c differs from each other so that the input connectors 110 a , 110 b , 110 c are staggered and do not overlap each other. In other words, in order to prevent the input connectors 110 a , 110 b , 110 c from overlapping, except for the shortest cable, the length of each of the cables 110 a , 110 b , 110 c is successively longer than the next shortest cable. For example, the length of the cables may be selected so that a difference in length between two cables is at least greater than a length of the input connectors 110 a , 110 b , 110 c , or greater than a sum of the length of the input connectors 110 a , 110 b , 110 c and a length of output connectors of the cables 111 a , 111 b , 111 c coupled to the input connectors 110 a , 110 b and 110 c . FIG. 2 illustrates the input connectors 110 a , 110 b , 110 c which do not overlap each other.
[0041] If the length of the cables 130 a , 130 b , 130 c is the same, the input connectors 110 a , 110 b , 110 c may overlap each other and thus the overlapped input connectors 110 a , 110 b , 110 c may occupy a substantial volume behind the TV 200 . For example, if the TV 200 is a wall-mounted TV, the overlapped input connectors 110 a , 110 b , 110 c may be disposed between a rear surface of the wall-mounted TV and a wall, and, thus, the overlapped input connectors 110 a , 110 b , 110 c may occupy a substantial space between the rear surface and the wall. Accordingly, it may be difficult to closely attach the TV 200 to the wall. Although only three input connectors 110 a , 110 b , 110 c are provided in this exemplary embodiment, the wall-mounted TV may require more input connectors. That is, because the number of peripheral devices connected to the TV 200 may be increased, transfer of various signals such as audio signals other than image signals may be required. Even with a large number of input connectors, the signal transfer apparatus 100 according to the exemplary embodiment facilitates close attachment of the wall-mounted TV to the wall because the input connectors 110 a , 110 b , 110 c do not overlap each other.
[0042] Referring to FIG. 1 , the single output connector 120 includes an output terminal 121 , the signal regions 122 a , 122 b , 122 c , and a ground region 123 .
[0043] The output terminal 121 is inserted into the terminal 201 of the TV 200 to be connected to the TV 200 , as shown in FIG. 2 . That is, the inserting direction of the output terminal 121 is parallel to a display plane of the TV 200 . Accordingly, although the output terminal 121 is inserted into the terminal 201 , the space between the rear surface of the TV 200 and the wall to accommodate the output connector 120 is minimized so that the TV 200 may be more closely attached to the wall. The output terminal 121 is formed in a pin shape as shown in FIG. 1 , but the output terminal 121 may be configured in various shapes.
[0044] The signal regions 122 a , 122 b , 122 c receive the signals from the input connectors 110 a , 110 b , 110 c , respectively, via the cables 110 a , 110 b , 110 c . Referring to FIG. 3 , the first signal region 122 a receives and outputs the luminance signal Y through the first input connector 110 a , the second signal region 122 b receives and outputs the first color difference signal Pb through the second input connector 110 b , and the third signal region 122 c receives and outputs the second color difference signal Pr through the third input connector 110 c.
[0045] The ground region 123 is connected to ground points 140 , 142 , 144 of the first, second, and third input connectors 110 a , 110 b , 110 c , as shown in FIG. 3 .
[0046] The first, second, and third signal regions 122 a , 122 b , 122 c , and the ground region 123 are formed lengthwise along the output terminal 121 as shown in FIG. 1 . Accordingly, although only one output terminal 121 is provided, each signal Y, Pb, Pr is individually transferred to the TV 200 . An insulating material 125 is disposed between the first, second, and third signal regions 122 a , 122 b , 122 c and the ground region 123 . The insulating material 125 obviates the plurality of signals from being jammed up.
[0047] According to the exemplary embodiment as described above, the plurality of signals Y, Pb, Pr is transferred to the TV 200 using a single output connector 120 so that the TV 200 needs only one terminal 201 to connect the output connector 120 . Accordingly, the number of the terminals mounted to the TV 200 is reduced, and thus it allows the TV 200 to be miniaturized. Moreover, as the lengths of the plurality of cables 130 a , 130 b , 130 c connecting the output connector 120 and the plurality of input connectors 110 a , 110 b , 110 c differ from each other, the input connectors 110 a , 110 b , 110 c do not overlap. Therefore, if the TV 200 according to an exemplary embodiment is a wall-mounted TV, the wall-mounted TV may be closely attached to the wall. The TV 200 according to an exemplary embodiment may be a light emitting diode (LED) TV, which is a substantially thin device.
[0048] The foregoing exemplary embodiments and advantages are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other types of apparatuses. Also, the description of the exemplary embodiments is intended to be illustrative, and not to limit the scope of the claims, and many alternatives, modifications, and variations will be apparent to those skilled in the art.
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Electronic apparatus includes a cable assembly including a first component video signal input connector which is connected with a first component video signal external connector of a first component video signal external cable to receive a first component video signal; a second component video signal input connector which is connected with a second component video signal external connector of a second component video signal external cable to receive a second component video signal; a third component video signal input connector which is connected with a third component video signal external connector of a third component video signal external cable to receive a third component video signal; a single pin shaped output terminal; and a display including an input terminal which is provided on a rear side of housing and adapted to connect with the single pin shaped output terminal to receive the first, second and third component video signals.
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