description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to radio receivers. More specifically, this invention relates to communications modems which incorporate frequency tracking systems.
While the present invention is described herein with reference to particular embodiments and applications, it is to be understood that the invention is not limited thereto. Those of ordinary skill in the art having access to the teachings of this invention will recognize additional applications and embodiments within the scope thereof.
2. Description of the Prior Art
Remotely piloted aircraft or drones may be utilized to provide effective reconnaisance of an enemy position at the forward edge of a battle area. In hostile environment, the drones are subject to destruction by counterfire or being jammed by electronic countermeasures. As a result, it has come to be recognized that such remotely piloted aircraft should be equipped with minimally expensive dispensable hardware, sufficiently sophisticated to penetrate the enemy's electronic defenses.
Drones are currently guided by signals transmitted at relatively low data rates. The rate of transmission typically is on the order of a few hundred bits per second or less. When the aircraft is in flight, the transmitted signals experience Doppler shift in the carrier signal which induces drift or frequency offset in the demodulated data signal. With a carrier signal on the order of 10GHz and the drone flying at a velocity of a few hundred miles per hour, the Doppler shift is on the order of the data rates. The Doppler effect thus interferes with the capability of the drone to receive and interpret guidance commands.
Systems which employ phase lock loops (including decision directed loops) to track the carrier frequency are effective in overcoming the effect of Doppler shift. However, such systems are typically limited in operation to coherent signals, i.e., those having long term phase continuity relative to the time constant of the phase lock loop.
These systems would provide adequate frequency tracking were it not for the desirability of hardening the drone against countermeasures. Unfortunately, some very effective counter-countermeasures, particularly frequency hopping, render the received signal substantially noncoherent.
It is therefore desirable to provide an inexpensive communications modem for use in remotely piloted vehicles which is capable of compensating for Doppler shift in the carrier frequency while being compatible with conventional electronic counter-countermeasure signal preprocessing techniques.
SUMMARY OF THE INVENTION
The present invention is an adaptive recursive frequency offset tracking system for effectively acquiring and tracking coherent and well as non-coherent electromagnetic data signals.
The system includes circuitry for eliminating the carrier frequency and generating complex samples of the baseband signal.
The system compares the phase of a sample to that of the previous sample to extract signals representing the phase difference between the two. The signals representing the phase difference are then converted to phasor signals and filtered to eliminate any noise component.
The phase difference signals are derived from the phasor signals and accumulated to derive signals representing the frequency offset of the received data signal.
The frequency offset signal is then provided to a phase shifter to correct for the effect of Doppler shift on the received data signal.
BRIEF DESCRIPTION OF THE DRAWINGS
The FIGURE is a block diagram of an illustrative embodiment of the present invention.
DESCRIPTION OF THE INVENTION
The illustrative embodiment of the present invention 10 is shown in the FIGURE. The radio frequency subsystem 12, though not part of the invention, is shown for the purpose of illustration. Radio signals received by an antenna are amplified and converted to an intermediate frequency ω o by the RF subsystem 12, and are fed into demodulators 14 and 16 which are driven by the cosine and sine of ω o t and respectively. The sin ω o t and cos ω o t are generated by the π/2 phase splitter (quadrature hybrid) 20 which operates on the output of the local oscillator 18. The carrier signal is removed by the demodulators 14 and 16 which serve to generate the complex representation of the received signal. The outputs of demodulators 14 and 16 are input to low pass filters 22 and 24. The outputs of filters 22 and 24 are switched by gates 26 and 28 respectively which operate under the control of a clock 27. Note that in cases where the frequency ω o is not constant (as would be the case for a frequency hopped signal) a timing recovery mechanism (not shown) would be required to synchronize the sampling clock with the local oscillator. (For the purposes of illustration, the remaining clock connections are not shown to the circuits of the present invention. The timing and clocking of the present invention is obvious to one of ordinary skill in the art.) The outputs of sampling gates 26 and 28 are input to analog-to-digital (A/D) converters 30 and 32 respectively. The outputs of the A/D converters 30 and 32 are input to a phase shifter 34 via lines 36 and 38 respectively. The real part of the complex digital data signal is provided on line 36. The imaginary part of the complex digital data signal is provided on line 38.
The phase shifter 34 effectively corrects the phase of the signal received on lines 36 and 38 by an amount determined by the circuitry to be discussed more fully below. The real part of the signal shifted by the phase shifter 34 appears on line 40 and is input to a phase detector 44. The imaginary part of the signal shifted by the phase shifter 34 appears on line 42 and is also input to the phase detector 44. The phase detector 44 extracts the phase angle of the shifted signal. This output is applied to a modulo 2π phase differentiator 46, which supplies one output sample for each pair of input samples. The output of the modulo 2π phase differentiator 46 is input to a converter 52. The converter 52 converts the signals to phasor form. The cosine of the converted signal appears on line 54 and the sine of the converted signal appears on line 56. Line 54 feeds a summer 58 while line 56 feeds a squaring operator 60 and a phase detector 62. The output of the summer 58 is input to the phase detector 62 and a second squaring operator 64. The squaring operators 60 and 64 input to a summer 66. The square root operator 68 operates on the output of the summer 66 to provide a signal to a damping amplifier 70. This square root of the sum of the squares equals the magnitude of the complex signal applied to the phase detector 62. The damping factor F is introduced by the amplifier 70 as a design parameter to control the loop bandwidth. The output of the amplifier 70 is input to a delay circuit 74. The output of the delay circuit is fed into the summer 58.
For reasons which will be more evident from the discussion of the operation of the invention below, the output of the phase detector 62 is input to a summing circuit 76. The summer 76 adds to the output of the phase detector 62 a signal equal to the previous output of the summer 76 which is provided by the delay circuit 80. The output of the summer 76 is sampled and held by circuit 78 which provides a 1:2 resampling of the signal. A summer 82 then sums the sampled and held signal with its previous output as provided by the delay circuit 84 and provides the phase shift correction to the phase shifter 34.
The operation of the present invention can best be understood with reference to the following mathematical discussion. The signals received by the RF subsystem 12 can be assumed to have the form Z(t). This represents a signal at a center carrier frequency of ω o ; the signal is assumed to be continuous over two consecutive sampling intervals. The demodulators 14 and 16 operate with the local oscillator 18 and the phase shifter 20 to remove the carrier signal and create a complex baseband signal from the received signal.
The low pass filters 22 and 24 average the received signals Z(t) by integrating over a time interval T s (one sampling interval). Switches 26 and 28 are clocked to sample the complex baseband signal to derive a plurality of complex samples. The l th sample of the complex baseband signal may be expressed by the following equation. ##EQU1## Multiplication by e -j ω.sbsp.o t' represents the action of the demodulators 14 and 16. The integral is evaluated at a time t which is equal to the product of the sample number l times the sampling interval T s .
The angular frequency offset δ which the system 10 of the present invention substantially compensates for is equal to the phase difference due to frequency offset between successive samples ψ divided by the sampling interval T s or ##EQU2## The frequency offset δ is assumed to remain essentially constant. The first two samples are passed through the phase shifter 34 to the phase detector 44 without correction. The modulo 2π phase differentiator 46 compares the phase angle of one sample to that of the previous sample. That is, the first and second samples are compared. The phase differentiator 46 stores a first phase angle within a pair and subtracts it from the second phase angle within a pair to provide an output to the converter 52 which is equal to the phase difference therebetween. Note that there will be half as many outputs from the phase differentiator 46 as there are samples as it requires two samples to provide a single output. The phase detector 44 and the phase differentiator 46 together provide means for comparing the phase of successive samples to extract signals representing the phase difference between two samples.
The phase difference φ is converted to a phasor e j φ by converter 52. Note that conventional systems filter the phase difference signal at this processing stage. As a result, conventional systems are inclined to suffer from a momentary inability to correctly compute the proper correction when the phase difference is π or -π; this is due to confusion as to which sign the correction should have. For further discussion see Gardner, F. L., "Hangup in Phase Locked Loops", IEEE Trans. on Communications COM-25, No. 10, pp. 1210-1214, October 1977. Conversion to a phasor signal at this point is advantageous relative to the systems of the prior art insofar as the phasor output for a phase difference of π is identical from that for a phase difference of -π. As a result, the system of the present invention will not get confused and therefore is expected to exhibit markedly smaller acquisition time than such prior art systems.
In addition, conversion to phasor signals allows the loop bandwidth to be adjusted dynamically, based on a track quality indication, as is explained below.
The phasor signals representing the phase difference between successive samples are provided as outputs on lines 54 and 56. By Euler's equation, e j φ =cos φ+j sin φ where j is equal to the square root of -1. Accordingly, the cos φ appears on line 54 and the sin φ appears on line 56.
The summing circuit 58, squaring operators 60 and 64, phase detector 62, summing circuit 66, squaring operator 68, damping amplifier 70, and delay operator 74 provide means for filtering the phasor signals to remove the effects of noise. The output of the low pass filter is given by the following equation: ##EQU3## where ρ k e j ψ.sbsp.k is the output of the low pass filter expressed as a complex quantity; ψ k is the phase of the filter output and ρ k is the magnitude of the filter output. F is the damping factor of the filter chosen as a system parameter to determine filter averaging time and thus to control the loop bandwidth.
The low pass filter operation may be best explained in polar coordinates. Equation [3] is equivalent to equations [4] and [5] below. That is, to examine the magnitude ρ k of equation [3], one may multiply the right hand side of the equation by the term e j ψ k-1. Since this term is an argument term, it does not affect the magnitude ρ k which may therefore be expressed by equation [4] below.
ρ.sub.k =∥Fρ.sub.k-1 +e.sup.j(φ.sbsp.k.sup.-ψ.sbsp.k-1.sup.) ∥[4]
Equation [4] provides the magnitude of the filter output and equation [5] below provides the phase. The phase ψ k is equal to the argument of equation [4] plus a term which compensates for the multiplication at the right hand side of equation [3] by e -j ψ k-1. Thus, ##EQU4## ψ k is therefore the estimate at time t=2kT s of the phase difference between samples of the input signal Z and Fρ k-1 is the bandwidth control and loop tracking quality indicator.
Squaring operators 60 and 64, summer 66 and square root operator 68 cooperate to provide the magnitude of the phasor output of the converter 52. The damping factor is applied by the amplifier 70 and fedback to delay operation 74 so that Fρ k is stored and becomes Fρ k-1 for the subsequent iteration.
The phase detector 62 provides means for extracting the phase difference signals from the phasor signal to provide the estimate of phase difference ψ k of equation [5]. It provides the argument of the sum of the current phasor and the previous filter output. See equation [3].
The estimate of phase difference between successive samples of the input signal Z(t) is provided by the phase detector 62 as an input to the summing circuit 76. The previous output of the summing circuit 76 is fed back to the summer 76 via delay operator 80. The absolute phase estimate θ referenced to a k index can be expressed by equations [6] and [7] below:
θ.sub.2k+2 =θ.sub.2k+1 +ψ.sub.k [ 6]
θ.sub.2k+1 =θ.sub.2k +ψ.sub.k [ 7]
Thus, ψ k is the phase increment used to accumulate the absolute phase correction θ l . There are two equations here because one new value of ψ k generates two values of θ l . The k index arises from the condition that two k samples are required for each l correction. The 1:2 sample and hold circuit 78 facilitates the conversion from the k index to the l index. The equivalent equation referenced to the l index is:
θ.sub.l =θ.sub.l-1 +ψ.sub.k [ 8]
where l=2k+2 or l=2k+1.
Summer 82 and delay operator 84 cooperate to input to the phase shifter 34 the previous absolute phase estimate θ l-1 plus the estimate of the phase difference between successive samples ψ k as required by equation [8]. Thus summer 76, sample and hold circuit 78, delay operator 80, summing circuit 82, and delay operator 84 cooperate to provide means for accumulating the extracted phase difference signals to derive signals representing the frequency offset of the received data signal.
Recalling equation [2], the frequency offset δ is equal to the phase difference ψ divided by the sampling interval T s . The measurement Δψ k is computed as ##EQU5## which is equivalent to what was given above because
ψ.sub.k-1 =θ.sub.2k -θ.sub.2k-1 and [10]
φ.sub.k =arg{Z.sub.2k }-arg{Z.sub.2k-1 } [11].
The phase shifter 34 provides means for shifting the phase of the received data signal in response to the accumulated phase difference signals to substantially compensate for the frequency offset. The resulting phase estimate θ l is applied to the input signal Z l such that the output of the phase shifter 34 is the corrected signal Z 1 e -j θ l .
The embodiment of FIG. 1 is referred to as an illustrative embodiment for two reasons. First, the demodulator subsystem (components 14 through 32) may vary in its detailed configuration depending on the nature of the signals whose frequency offset is to be estimated. Second, the preferred embodiment of the tracking subsystem (components 34 through 84) would be implemented on a digital computer by means of a program. The listing of one such program (written in the language PASCAL) is attached. The inputs to this program are the signals on data lines 36 and 38 and the outputs are the signals on data lines 40 and 42.
While the present invention has been described above with reference to particular embodiments and applications, it is to be understood that the invention is not limited thereto. Those having ordinary skill in the art and access to the teachings of the present invention will recognize additional embodiments and applications within the scope thereof. It is contemplated by the appended claims to cover any and all such applications. ##SPC1## ##SPC2## ##SPC3## ##SPC4## ##SPC5## ##SPC6## | An adaptive, recursive frequency offset tracking system for effectively acquiring and tracking coherent as well as noncoherent electromagnetic data signals transmitted with or without countermeasure protection. The invention includes circuitry for eliminating the carrier frequency and generating complex samples of the baseband signal. The invention compares the phase of a sample to that of the previous sample to extract signals representing the phase difference between the two. The signals representing the phase difference are then converted to phasor signals and filtered to eliminate any noise component. The phase difference signals are derived from the phasor signals and accumulated to derive signals representing the frequency offset of the received data signal. The frequency offset signal is then provided to a phase shifter to correct for the effect of Doppler shift on the received data signal. | 7 |
TECHNICAL FIELD
[0001] The present invention relates to the technical field of sound-attenuating earplugs and, in particular, to an earplug of the type which comprises an elongated body of elastic material that is adapted to be inserted into the auditory meatus of an ear. The invention also relates to a method of manufacturing such an earplug. Furthermore, the invention relates to a method of affecting the course of the attenuation curve of such an earplug.
[0002] The term “plug” here means a hearing protector which, when being used, is at least partially inserted into the auditory meatus of an ear, unlike ear-muffs which are adapted to be applied on the outside of the ear.
BACKGROUND ART
[0003] In the technical field of earplugs it is known, in connection with a longitudinal through duct of an earplug, to arrange a membrane in order to reduce the attenuation of the earplug in the range that is the most important one as regards speech perception.
[0004] For example, SE 8102931-6 (Racal) discloses that an essentially straight attenuation characteristic up to 2 kHz is aimed at. Said application, which mainly relates to ear-muffs, also shows an earplug having a through duct, in which a membrane is fixed to the duct wall. The membrane functions in the range below its resonance frequency as an attenuation reducing means and, thus, allows more sound to be let through. No detailed discussion of the properties of the membrane is to be found.
SUMMARY OF THE INVENTION
[0005] The object of the present invention is to provide an improved earplug of the above general type provided with a membrane.
[0006] Another object of the invention is to provide an easy method of manufacturing such an earplug.
[0007] Yet another object of the invention is to use and affect the sound characteristics of the membrane in a better and more efficient manner.
[0008] These objects are achieved by means of an earplug and methods which exhibit the features stated in the claims.
[0009] According to one aspect of the present invention, an earplug is provided, by starting out from a basic plug which has a through duct in the longitudinal direction of the plug. The invention is based on the understanding that the application of the membrane and the possibility of affecting the membrane's own inherent properties and its sound and attenuation affecting properties are considerably facilitated by the membrane being arranged on a stabilising fixing part, a membrane holder, whereby the membrane is applied in the duct. The membrane together with the membrane holder will in the following be named membrane element.
[0010] Such a configuration of a membrane element gives great advantages and possibilities regarding a simple, but yet accurate positioning of the membrane in the duct. The membrane holder simply facilitates the handling of the membrane. Since the membrane holder conveniently has a certain degree of stiffness, it may also prestress or tighten the membrane which thus obtains the desired stiffness.
[0011] The earplug according to the present invention is preferably a non-disposable plug and is in that case adapted to be used on more than one occasion. Naturally, this makes it necessary for the membrane to be firmly arranged in the duct, in such a manner that there is no internal displacement of or other external action on the membrane in the duct when a user repeatedly removes and inserts the plug. The membrane holder affords this stability and contributes to securing the membrane in place. The membrane holder which preferably has an extended tubular form is with its circumferential surface suitably, in the applied state, in engagement with the wall of the duct.
[0012] Advantageously, the membrane element can be arranged in and seal the through duct of the basic plug after the basic plug has been made. An uncomplicated application of the membrane simply means that the membrane element is inserted into the through duct in the longitudinal direction of the plug to a predetermined position, so that the membrane holder engages the duct wall, or means arranged thereon, in order to attach the membrane element. When applying the membrane element in the through duct, the duct is defined or divided, so that one internal and one external duct part are formed.
[0013] Due to the design of the membrane element according to the invention there is also a possibility of moulding an earplug round the membrane element by the membrane holder being moulded at or in the duct wall.
[0014] According to a preferred embodiment of the invention, the membrane holder has the form of an essentially tubular, preferably circular, cylinder. The membrane is suitably adapted to essentially cover one end of the cylinder.
[0015] The membrane and the membrane holder are preferably formed in one piece. Such a variant of the membrane element could conveniently, as regards its form, be compared to a mug without an ear or a cartridge case, where the membrane corresponds to the bottom of the mug and the membrane holder corresponds to the cylindrical wall of the mug.
[0016] The membrane may be formed as a thin film with a typical thickness of 0.1 mm. The membrane holder may advantageously have a wall thickness of about 0.5 mm.
[0017] The membrane element which, after application in the basic plug, in a sealing manner divides the duct into two parts, one internal and one external part, has in a preferred embodiment of the present invention a pure membrane function, i.e. the membrane element is free from further means, such as sound-absorbing means. However, the membrane element may comprise more than one membrane which are held by the membrane holder. According to the invention, the external and internal duct parts of the earplug are preferably completely free from further means, such as further sound-absorbing means. However, it is possible to apply several membrane elements according to the invention in one and the same through duct of the earplug.
[0018] According to one aspect of the invention, a method of efficiently using and affecting the sound affecting characteristics of the membrane and the sound-attenuating characteristics of the earplug is provided. No sound is actually “damped” in the earplug by the membrane. Incident sound is simply reflected out again and does not reach the eardrum. The function of the membrane is to “oscillate”, which means that some sound goes through, i.e. is not reflected. This function means that the sound attenuation of the ear plug is reduced at a frequency where the membrane oscillates, i.e. at the resonance frequency of the membrane. The effect of the membrane on the attenuation is clearly seen from an attenuation curve of an earplug according to the present invention. The resonance frequency of a membrane is determined, inter alia, by its mass, area, stiffness and prestress.
[0019] We have realised that if, for example, it is desirable to provide a membrane with a relatively low resonance frequency, a comparatively thicker membrane may be used. However, the use of a thick membrane has several disadvantages. There is, for example, a risk that the membrane gets too stiff, which then leads to the opposite effect, i.e. higher resonance frequency. However, it is not only the attenuation curve that is directed upwards as regards frequency, but the attenuation also increases at the resonance frequency at issue. If an ideal membrane were made thicker, an increased oscillating mass would be obtained, which would lead to a lower resonance frequency. However, if a non-ideal membrane were made thicker, it would give both an increased stiffness and an increased mass, which thus would result in a smaller change of the resonance frequency than for an ideal membrane. An increased stiffness and an increased mass give a decreased sound transmission, i.e. the effect of the resonance is not evident to the same extent.
[0020] Furthermore, we have realised that there are great possibilities of affecting the sound characteristics of the membrane by using the air columns which are formed on each side of the membrane when the membrane element has been applied in the through duct and in a sealing manner divides the duct into two parts. Both the air columns can weigh down the membrane and direct its resonance downwards as regards frequency. In other words, a relatively low resonance frequency may be achieved also by means of thin membranes by adapting the length and the area (especially the mouth area) of the duct or the air columns. A long and thin air column is from an acoustic point of view heavier than a short and wide one. For instance, the external air column, i.e. that between the world around and the membrane, may be formed with a narrower inlet hole, which gives a “heavier” column. The internal air column, i.e. that between the eardrum and the membrane, may also be allowed to affect the resonance frequency by different designs of the duct. As regards a duct which is tapering towards the eardrum, the internal air column becomes acoustically heavier than the external air column. The through duct may, of course, be formed in different ways, the acoustic weight being dominated by the narrowest area of the duct and by the length of the duct. Consequently, by choosing the position of the membrane in the through duct and/or the mouth area, e.g. towards the eardrum, it is possible to displace the resonance of the membrane to a suitable frequency. Having a membrane element according to the present invention considerably facilitates the possibility of choosing, as regards the membrane, an accurate position in the duct.
[0021] As mentioned above, an earplug according to the present invention is conveniently manufactured by forming a basic plug with a through duct, after which the membrane element is inserted into the duct. This inventive idea gives great freedom of choice and many possibilities of working with different parameters. Since the membrane element is mounted later, it is possible at a late stage of the manufacturing process to determine what properties the earplug should have. It is, for instance, possible to use membranes with various inherent properties independently of the dimensions of the duct. Moreover, it is possible to choose in what direction the membrane element is to be inserted into the duct, i.e. how far into the duct the membrane itself should be placed, etc.
[0022] The membrane element according to the present invention has in the preferred cylindrical embodiment suitably a diameter of 2-6 mm, preferably 3-4 mm, for example 3.4 mm. The length of the membrane element is preferably 1-8 mm, for instance 2 mm. The thickness of the membrane itself is preferably 0.005-0.5 mm, such as 0.1 mm, and the wall thickness of the membrane holder itself is preferably 0.3-2 mm, for example 0.6 mm. The membrane element is preferably of a general flexible material which can be adapted to the earplug and the Shore number of the membrane element is preferably 5°-80° A, for instance 60° A.
[0023] The membrane element is preferably formed in one piece by silicone injection of LSR (Liquid Silicone Rubber), for example LR 3003 or the like. Silicone injection might be called “reversed” injection moulding. In traditional injection moulding hot thermoplastics are used which are formed, cooled and solidified. However, in silicone injection, one works in a reversed manner by using a cold, liquid silicone fluid which contains a substance that allows the material to be cured when heated. Thus, the liquid, cold silicone fluid is injected into a mould under high pressure, pressed and heated, so that the silicone fluid is cured. By means of this technique, it is possible to mould a membrane which is a thin film of 0.1 mm. The membrane holder is preferably formed to have a wall thickness of about half a millimetre.
[0024] The basic plug which is contained in the earplug according to the present invention may, for instance, be manufactured essentially in the same way as the earplug described in EP 0 847 736. The difference is that the duct in the earplug according to the present invention is a through duct and, therefore, the core element round which the plug is moulded is thus made longer so that it extends through the entire cavity in the mould half. The basic plug may either be moulded in one single material or in several materials (e.g. for different plug parts).
[0025] In connection with the moulding of the basic plug, the duct wall may be formed so that, when applying the membrane element, it co-operates with the same by the membrane holder engaging the duct wall. The aim of this is to secure the membrane element in place when it has been inserted into the duct. Naturally, such securing can be performed in many ways, for instance by means of a shoulder or by using a mould cavity when forming, which gives an undercut in the duct wall. Thus, a simple snap lock is provided. The membrane element is thus inserted into the duct until it passes the undercut and is locked. There are, of course, also other possible ways of keeping the membrane element in place, such as friction joints, gluing, etc., which all are in the scope of the overall idea of invention. This also includes the possibility of arranging a special retaining means on the duct wall, which is not formed integrally with the wall.
[0026] Furthermore, it is possible to make a duct wall with a plurality of such stops, for example shoulders, retaining means etc. in various positions along the duct wall, so that the membrane can be arranged in different positions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] [0027]FIG. 1 is a longitudinal axial section of an earplug according to an embodiment of the present invention.
[0028] [0028]FIG. 2 a shows an enlargement of a portion of the earplug in FIG. 1 with the membrane element.
[0029] [0029]FIGS. 2 b - 2 d show examples of a cross-section along the line A-A in FIG. 2 a.
[0030] [0030]FIGS. 3 a - 3 b schematically show an example of a membrane element for use in an earplug according to the present invention.
[0031] [0031]FIGS. 3 c - 3 g illustrate alternative embodiments of the membrane element according to the present invention.
[0032] [0032]FIGS. 3 h - 3 i illustrate various cross-sections of the membrane element according to the present invention.
[0033] [0033]FIG. 4 illustrates how a membrane element is applied in a basic plug according to a preferred embodiment of the invention.
[0034] [0034]FIG. 5 schematically shows an earplug according to the invention being applied in a user's ear.
[0035] [0035]FIG. 6 shows, as in FIG. 1, a longitudinal axial section of an earplug according to yet another embodiment of the present invention.
[0036] [0036]FIGS. 7 a - 7 c schematically show the principle of a preferred method of manufacturing a membrane element according to the present invention.
[0037] [0037]FIG. 8 shows an equivalent electric circuit diagram for an earplug according to the present invention.
[0038] [0038]FIGS. 9 a - 9 d show diagrams of attenuation curves for earplugs according to the present invention.
[0039] [0039]FIG. 10 shows a longitudinal axial section of an earplug according to yet another embodiment of the present invention.
[0040] [0040]FIG. 11 illustrates as FIGS. 3 c - 3 g an alternative embodiment of the membrane element according to the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0041] [0041]FIG. 1 shows a longitudinal axial section of an earplug 2 according to an embodiment of the present invention. The earplug 2 comprises a core or body part 4 which essentially has the form of a truncated cone. The front part of the core or body part 4 is provided with a surrounding sleeve or sealing part 6 . From the circumference surface of the sealing part 6 four integrated annular flanges 8 , 10 , 12 , 14 protrude in the radial direction which is perpendicular to the longitudinal direction of the core or body part 4 . A first flange 8 protrudes directly at the front edge of the earplug 2 and has the smallest diameter. The other flanges 10 , 12 , 14 are evenly distributed over the plug part itself and have diameters that successively increase backwards along the plug 2 . The front surface of the flanges 8 , 10 , 12 , 14 is inclined backwards, while the rear surface of the flanges is perpendicular to the longitudinal or axial direction of the plug 2 .
[0042] The sleeve-shaped sealing part 6 covers the part of the core or body part 4 which is intended to be inserted into the auditory meatus of the ear, i.e. the entire actual plug. This is illustrated in FIG. 5, where the front part (the sleeve-shaped sealing part 6 ) of the earplug 2 is inserted into the auditory meatus H of the ear. As seen the four annular flanges 8 , 10 , 12 , 14 abut in sealing condition against the wall of the auditory meatus H. The rear part of the core or body part 4 is adapted to be a handle portion 5 . The core or body part 4 has a through axial duct 16 of circular cross-section, the diameter of which decreases approximately from the handle portion 5 to the top. FIG. 1 shows that the duct wall of the core or body part 4 has approximately at the middle of the length of the handle portion 5 an annular bulge 18 and somewhat further forwards an annular protruding shoulder 20 which is formed by decrease of the diameter of the duct. The bulge 18 and the shoulder 20 in the wall are made during the moulding of the core or body part 4 and are formed integrally with the core or body part 4 .
[0043] In the through duct 16 , a membrane element 22 is applied in a sealing and defining manner between the bulge 18 and the shoulder 20 . The portion round the membrane element 22 is shown enlarged in FIG. 2 a . The membrane element 22 itself is shown in a perspective view in FIG. 3 a , and FIG. 3 b is an axial cross-sectional view along the line A-A in FIG. 3 a . It is evident from the figures that the membrane element 22 comprises a cylindrical tubular membrane holder 24 with a wall thickness of about 0.5 mm. A circular membrane 26 , which is about 0.1 mm thick, is arranged transversely as a lid at the very front of the membrane holder 24 . The membrane element 22 is about 2 mm long and has a diameter of about 3.4 mm. The diameter of the membrane is about 2.4 mm. The membrane holder 24 and the membrane 26 are according to this preferred embodiment formed integrally according to a method which will be described below. FIGS. 1 and 2 a show the membrane element 22 , as mentioned above, arranged between the bulge 18 and the shoulder 20 . The front end of the membrane holder 24 abuts against the annular shoulder 20 protruding from the duct wall, while the rear end of the membrane holder abuts against the bulge 18 , and, moreover, the cylindrical surface of the membrane holder engages the duct wall. Thus, the membrane element 22 is fixed. The bulge may have different shapes, for instance annular, or consist of several projections or ribs. This is shown in FIGS. 2 b - 2 d with examples of a transverse cross-section along the line A-A in FIG. 2 a . In FIG. 2 b the bulge 18 b is annular. In FIG. 2 c four projections 18 c are shown, but the number of these can, of course, be both greater or smaller, and the shape need not necessarily be rounded. FIG. 2 d shows four ribs 18 d of which there also may be more or fewer and which may have different shapes. Besides, the length L which is indicated in FIG. 2 a may vary for the different types of bulges. The advantage of longer bulges is that the membrane element 22 is very well locked. However, such longer bulges cause greater resistance when inserting the membrane element 22 .
[0044] [0044]FIGS. 3 c - 3 g show alternative embodiments of the membrane element 22 b - 22 f for use in an earplug according to the present invention. The membrane elements are seen in the direction of the extension of the duct. Apart from the already shown circular shape, essentially all shapes are possible, both symmetrical and asymmetrical. For example, N-gons may be formed with everything from 3 corners up to an infinite number of corners, i.e. a circular shape. Also various oval forms are possible. In the figures only a few shapes are shown by way of illustration. FIG. 3 c shows a circular shape, FIG. 3 d shows a triangle, FIG. 3 e shows a square shape, FIG. 3 f shows an oval shape and FIG. 3 g shows an octagon. In all the cases, the membrane 26 b - 26 f constitutes the internal portion and the membrane holder 24 b - 24 f the surrounding external portion. FIGS. 3 h - 3 i show two possible axially longitudinal sections of the above membrane elements 22 b - 22 f . Naturally, also other cross-sections are possible. All the shown membranes may, for example, have the already shown U-shaped cross-section which is now shown in FIG. 3 h , or an H-shaped cross-section as shown in FIG. 3 i . In the case of the illustrated H-shaped cross-section, the membrane holder 24 h comprises the two parallel legs and the membrane 26 h is the transverse leg between these. As shown in FIG. 3 i , the membrane 26 h is displaced somewhat to the left of the centre of the membrane holder 24 h . This H-shaped configuration thus gives the possibility of choosing in an easy way between two different locations of the membrane 26 h in the duct and, thus, also air columns which affect the membrane resonance differently. Various types of membrane resonance are obtained simply depending on which end of the membrane element is inserted first into the through duct of the plug. Generally speaking, membrane elements of different shapes can be inserted with either end of the membrane element being directed towards the duct, the final location of the membrane in the through duct determining the appearance of the attenuation curve.
[0045] The through duct in the plug conveniently has the same transverse dimension as the membrane element, at least at the portion where the membrane element is placed when using the earplug. For instance, the shoulder against which the membrane element abuts can be formed in accordance with the membrane element. It is essential that a good sealing division of the duct is provided, which results in one internal and one external air column after applying the membrane element, and that the membrane element is firmly fixed.
[0046] It is thus evident from the figures that the membrane element 22 divides the through duct 16 into two parts. Between the membrane 26 and the eardrum T (FIG. 5) an internal air column 28 is formed in the duct part in front of the membrane 26 and an air volume in the auditory meatus H from the front end of the earplug 2 to the eardrum T. On the other side of the membrane 26 an external air column 30 is formed in the duct part behind the membrane 26 and the volume of the outside world O, i.e. an infinite volume. The length and the area of the air columns 28 , 30 affect the resonance frequency of the membrane 26 as already described.
[0047] [0047]FIG. 6 shows, as FIG. 1, a longitudinal axial section of an earplug according to an embodiment of the present invention. The axial location of the bulge 18 shown in FIG. 6 and the shoulder 20 and, thus, also the membrane element 22 is, however, different from the embodiment according to FIG. 1. The membrane element 22 is now placed further into the duct and, thus, the encased air volume or the air column 28 between the membrane and the eardrum is shorter. The effect of this is that the air column in FIG. 6 does not weigh down the membrane as much as the air column in FIG. 1, whereby the resonance frequency is not displaced to the same extent. It is thus possible, by choosing the location of the membrane in the duct, for example to control the resonance frequency so that, for instance, warning signals at a known frequency is let through more easily or that sound from a machine which is being operated is let through to a greater extent.
[0048] In the preferred embodiment according to FIG. 1, the membrane element is formed in one piece, but can, of course, within the scope of the invention be composed of two pieces (the membrane and the membrane holder).
[0049] The core or the body part and the sealing part may be made of two different materials or in one and the same material, preferably in one piece. As already mentioned, a preferred method of manufacturing these parts is described in EP 0 847 736.
[0050] [0050]FIG. 4 illustrates the application of a membrane element 22 in the through duct 16 of an earplug 2 . According to this preferred method, a membrane element 22 is made separately, as is also the earplug 2 with its core or body part and the sealing part. By means of a piston 40 the cartridge-shaped membrane element 22 is then inserted into the through duct 16 of the earplug 2 , as shown by the arrows in the figure, having the membrane 26 at the very front. The earplug 2 is preferably made of a material which is flexible enough to allow the membrane element 22 to be easily inserted. The piston 40 has, as shown in the figure, preferably an outline which supplementary corresponds to the outline of the membrane element 22 . A central part 42 which protrudes from the front end of the piston 40 thus fits into the membrane holder 24 and during insertion a circumferential part 44 abuts against the rear edge of the membrane element 22 . The membrane element 22 is thus moved forward in the duct 16 and eventually reaches the bulge 18 with its front part (i.e. the membrane 26 and the front part of the membrane holder 24 ). The membrane element 22 is continually moved forwards with a force enabling its front part to pass the bulge 18 . When the front part of the membrane element 22 or membrane holder 24 finally reaches the shoulder 20 , the rear part of the membrane holder 24 has passed the bulge 18 and been fixed by snap-in action. In this position the membrane element 22 is thus locked by the membrane holder 24 with its ends abutting against the bulge 18 and the shoulder 20 , respectively. As is evident from the figures, the membrane holder 24 is dimensioned so that its transverse dimension essentially corresponds to the dimension of the through duct 16 for retaining of the membrane element 22 when applied in the through duct of the ear plug, while at the same time the duct is sealed.
[0051] [0051]FIGS. 7 a - 7 c show a preferred method of manufacturing a membrane element 22 according to the present invention. The figures are not to scale, but should only illustrate the manufacturing principle schematically.
[0052] [0052]FIG. 7 a shows a transverse section of a mould 50 and an ingate 52 connected thereto. FIG. 7 b illustrates a cross-section along a dividing line of a mould. FIG. 7 c shows an enlargement of a portion in FIG. 7 a.
[0053] As mentioned above, the membrane element 22 is formed preferably by silicone injection of LSR (“Liquid Silicone Rubber”). For example, a silicone rubber from Silopren® LSR series 20xx or the like can be used for the purpose. After the correct composition of the liquid silicone rubber has been obtained, it is transferred from a tube to a screw feeder, alternatively a piston (not shown). By means of the screw feeder the liquid, cold silicone rubber is injected into a mould via an ingate 52 (FIG. 7 a ). An injection moulding pressure of 50-150 bar is generally enough for LSR. The pressure depends on the cross-section of the feeding duct.
[0054] The purpose of the mould 50 is to receive the silicone rubber in its mould cavity, spread, form and cure it, whereby the silicone rubber will be brought to a solid state, after which the ready material may be taken out of the mould 50 . FIG. 7 a shows the mould 50 in a section along the line A-A in FIG. 7 b . The mould 50 according to this preferred embodiment comprises two mould parts: one upper part 54 and one lower part 56 , which form a circular mould cavity. FIG. 7 b shows a cross-section along the parting line of the mould 50 , i.e. the border between the two parts. The ingate 52 is connected to the centre of the circular mould 50 and in the circumference of the mould 50 the mould cavity comprises membrane cavities 58 which together with a guiding pin 60 form a ring. The guiding pin 60 which is also shown in FIG. 7 a can be used as an aid for positioning in connection with subsequent handling of the mould product. When the liquid silicone rubber is fed via the ingate 52 to the mould cavity, the silicone rubber will flow out over the entire circular area and also down into the membrane cavities 58 . By forming the membrane elements in the periphery of the circular mould cavity, an even distribution of the liquid silicone rubber is obtained. When the moulding process is finished, a disk is thus obtained, which in the periphery exhibits the membrane element. The membrane elements may be pressed out simultaneously, but can also be pressed out one at a time. An earplug with a through duct can advantageously be placed on the top of a membrane element in such a manner that, when the membrane element is pressed out, it is inserted directly into the plug without any intermediate stages.
[0055] In order to facilitate the pressing-out of the membrane elements, the mould 50 is formed in such a way that the mould disk is thin round the membrane element. A flash ridge 62 is indicated by the arrows in FIG. 7 c which is an enlargement of the portion round the membrane cavity 58 to the right in FIG. 7 a . Moreover, the area immediately adjacent to the flash ridge is thicker than the rest of the surrounding area in order to ensure easy pressing-out of the membrane element. FIG. 7 c also shows the parting line between the two parts of the mould by means of a dashed line B-B. Thus, it is shown that essentially the entire membrane element is formed in the lower part of the mould.
[0056] The mould 50 is usually heated electrically (in general up to 150-230° C. depending on the type of LSR) by using, for instance, immersion heaters or filaments. The liquid silicone rubber is injected into the heated mould. The silicone rubber is cured at moulding temperatures of 170-230° C.
[0057] When the injected liquid silicone rubber is heated to a high temperature, it tries to swell and return to the injection nozzle. In order to prevent this, the nozzle is kept at a pressure of 50 bar until the liquid in the vicinity has started to cure.
[0058] The heating and the subsequent volume increase of the silicone rubber in the mould increase the pressure in the moulding cavity, which may attain about 300 bar.
[0059] Naturally, there are different types of silicone rubber, some of which (e.g. from the series Silopren® LSR 26xx) are more reactive and, thus, are cured faster. Besides, it is possible to start the heating of the silicone rubber in advance, for instance in the screw feeder, in order to speed up the curing process.
[0060] As mentioned in the introductory part of the present specification, it is possible by means of this technique to mould a membrane element, in which the membrane itself is a 0.1 mm thin film, and the membrane holder is given a thickness of about 0.5 mm.
[0061] An ordinary open ear, i.e. without a plug inserted, has a natural amplification of sound of about 3 kHz, i.e. the frequency range of human speech. When a plug is inserted, the air volume in the ear is changed, and, therefore, the natural resonance amplification is eliminated or changed, which thus means that the speech perception is impaired. FIG. 8 shows an equivalent electric circuit diagram for an earplug according to the invention, a voltage source P corresponding to the sound pressure that is received, the coil L P corresponding to the acoustic mass of the plug, the capacitor C P corresponding to the acoustic stiffness of the plug, the resistance R P corresponding to the acoustic attenuation of the plug and the capacitor C 1 corresponding to the acoustic stiffness of the included air volume. Furthermore, the coil L m corresponds to the acoustic mass of the membrane, the capacitor C m corresponds to the acoustic stiffness of the membrane and the acoustic attenuation is illustrated by the resistance R m . The acoustic mass of the encased air column corresponds to the coil L 1 which is connected in series with the coil L m . Naturally, also a coil for the external air column may be connected in series with the others, but in this case an equivalent circuit diagram for a plug is shown with a through duct that is tapering inwards (the air columns are of about the same length) and, therefore, the acoustic mass of the thinner air column is predominant.
[0062] As known, the impedance of a coil varies with the frequency as jωL and the impedance of a capacitor as 1/jωL. Resistance is independent of the frequency. The acoustic stiffness of the membrane, i.e. the value of the corresponding equivalent capacitor C m , is such that in connection with low frequencies the impedance 1/jωC m is greater than the impedance 1/jωC P and, thus, the membrane does not at such low frequencies have any considerable effect on the attenuation of the earplug. At high frequencies the impedance jω(L m +L 1 ) of the coils L m and L 1 (the acoustic mass of the membrane and the encased air column) is predominant, in which case sound at certain frequencies is attenuated to a large extent. Between said low and high frequencies there is a resonance range where the capacitors and the coils co-operate, so that the total impedance gets low and, thus, allows sound to pass. The earplug according to the present invention thus functions as a bandpass filter which lets through sound at frequencies within the predetermined range. It is thus within this range that the resonance is found. By choosing a suitable location of the membrane in the duct, it is possible to obtain a desired air column with a desired acoustic mass, so that the resonance frequency of the membrane is affected. In other words, it is possible to vary the impedance of the coil L l and, thus, the attenuation curve of the earplug by choosing the location of membrane. The impedance may also be varied by choosing the cross-sectional area or mouth area of the air column.
[0063] [0063]FIGS. 9 a - 9 d show diagrams of attenuation curves for earplugs according to the present invention.
[0064] [0064]FIG. 9 a shows four curves, one of which is for an ordinary earplug without a through duct and a membrane, and the other three are for earplugs according to the invention which have one and the same membrane element (membrane area 3.8 mm 2 and membrane thickness 1 mm) applied at different distances from the top of the earplug (17, 19 and 21 mm, respectively, from the top). As will be evident from the diagram, the attenuation is high at frequencies above 1000 Hz for an ordinary earplug. By means of an earplug according to the invention which has a membrane element arranged in the through duct of the plug, it is possible to provide a better sound transmission near the frequencies for speech perception. As shown, the attenuation at about 3 kHz is less for the earplugs according to the invention. The curves show that the further away from the top the membrane is placed, the more it is weighed down by a larger air column, which results in the resonance frequency decreasing. The curves further show that the closer to the top the membrane is placed, the better the sound transmission in the frequency range at issue.
[0065] [0065]FIG. 9 b shows curves for four earplugs with top holes having different areas (diameter=0.8 mm, 1.0 mm, 1.4 mm and 2.0 mm, respectively). The figure shows that the acoustic mass of the air column increases when the top hole is made smaller, the resonance frequency decreasing and the attenuation increasing. The membrane element is similar to that in FIG. 9 a.
[0066] [0066]FIG. 9 c shows two curves for earplugs, in which membranes of different thickness (0.1 mm and 0.3 mm, respectively) are applied in the same position (17 mm from the top) in the through duct of two similar plugs. By providing a thicker membrane both a greater mass and a greater stiffness of the non-ideal membrane are obtained. The diagram shows that this has no effect as regards frequency but the attenuation is smaller and the sound transmission thus higher for the thinner membrane.
[0067] [0067]FIG. 9 d shows two curves for earplugs, in which the applied membrane has different areas (3.8 mm 2 and 1.5 mm 2 , respectively). The dimensions of the through duct are the same in both earplugs, and both membranes are arranged 17 mm from the top. As seen, the frequency is not affected to any considerable extent in this case, but the sound transmission is improved by means of the membrane with the greater area.
[0068] [0068]FIG. 10 shows a longitudinal axial section of an earplug according to yet another embodiment of the present invention. This figure illustrates that more than one membrane element can be inserted into the earplug. In this example two membrane elements 70 , 72 are inserted, one 70 of which is arranged further into the duct than the other one 72 . The membranes are fixed between one bulge 74 , 76 and one shoulder 78 , 80 each. By means of two membranes which have the same resonance frequency, a resonance is obtained in such a configuration which remains at about the original resonance frequency since both the mass and the stiffness increase. However, the attenuation during the resonance for this double configuration becomes higher by comparison with a plug having one single membrane element.
[0069] Naturally, it is also possible, instead of using two membrane elements, to provide a membrane element which comprises a membrane holder, on which two membranes are arranged, one behind the other.
[0070] However, FIG. 10 shows the possibility of choosing two different locations of a single membrane element. If one single membrane element is to be used in the earplug in FIG. 10, air columns of different size may be provided (and, thus, various resonance frequencies) depending on between which bulge and shoulder a membrane element is placed.
[0071] [0071]FIG. 11 illustrates, as FIGS. 3 c - 3 g , an alternative embodiment of a membrane element according to the present invention. The membrane element 82 is, as in the figures described above, seen in the direction of the extension of the duct. This figure illustrates that the membrane element 82 can comprise several membranes 86 , 88 that are arranged next to one another on a membrane holder 84 . In this illustrated example, the membrane holder 84 is a circular cylinder (cf. FIG. 3 c ) which also has a cross-link 85 that extends along the diameter of the cylinder. Consequently, two membranes 86 , 88 are provided which are separated by the cross-link 85 . If the membranes 86 , 88 have different respective resonance frequencies, two resonance peaks are obtained, which makes it possible to decrease the attenuation in a greater frequency range.
[0072] The invention is, of course, not limited to the preferred embodiments described above which have been shown by way of example. It should be understood that a plurality of modifications and variations can be provided without abandoning the scope of the present invention which is defined in the appended claims. | The present invention relates to an earplug with a through duct, in which a membrane element is adapted and comprises a membrane holder and a membrane held thereby which is adapted to lock the membrane element. The invention also relates to a method of making such an earplug and a method of affecting the course of the attenuation curve of an earplug. | 7 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to computer-based education (CBE) systems and, in particular, to a computer-based education system that responds to a measured brain state to improve the retention of presented information.
BACKGROUND OF THE INVENTION
[0002] Computer-based education (CBE) holds significant promise for instructing individuals using educational programs implemented via computers instead of human instructors. In its simplest form, such CBE may present educational material in a traditional linear format of a human lecturer (for example, pre-recorded lectures to be played by the software) or such software may adopt a more complex organizational structure of interlinked audio and visual materials navigated by the student under computer supervision. Often computer-based educational programs provide a framework that includes practice exercises and tests and will modify the educational program based on the results of those exercises and tests.
[0003] Computer-based education can greatly expand access to high-quality educational materials prepared by talented educators and can leverage the efforts of skilled educators beyond the scope normally possible with an individual lecturer/student model. Nevertheless computer-based education is not yet as effective as the best human tutors.
SUMMARY OF THE INVENTION
[0004] The present invention significantly increases the effectiveness of computer-based education by adjusting the presentation of CBE material according to a monitored brain state of the student. In one embodiment, EEG sensing is used to identify changes in engagement or attention by the student and to trigger attention-promoting interventions based on a dynamic engagement threshold. More specifically, in one embodiment the present invention provides a computer-based education system having a brain activity monitor providing a monitoring of brain activity of the student. An electronic computer communicating with the brain activity monitor presents an educational program to the student while it receives a signal from the brain activity monitor indicating a brain activity of the student to provide an engagement signal indicating student attention. The engagement signal is compared to a dynamic threshold to identify a plurality of points demarcating periods of declining attention and the presentation of the educational program is modified to promote student attention at times of the identified points.
[0005] It is thus a feature of at least one embodiment of the invention to practically identify points of declining engagement applicable to a wide range of students and educational materials. The creation of a dynamic threshold accommodates differences in individuals to successfully initiate attention-enhancing stimulation for those individuals.
[0006] The brain activity monitor may be, for example, an EEG monitor or a functional near infrared imaging monitor.
[0007] It is thus a feature of at least one embodiment of the invention to provide a system that can use with currently developed low-cost brain monitoring equipment suitable for use and ownership by individual students.
[0008] The brain activity monitor may be an EEG monitor providing a signal including, alpha, beta and theta waves from the brain.
[0009] It is thus a feature of at least one embodiment of the invention to provide a system that exploits the information in well-understood and detected categories of brain waves.
[0010] The engagement signal may comprise a functional combination of multiple brain waves increasing with increasing beta wave strength and decreasing with increasing alpha and theta wave strength.
[0011] It is thus a feature of at least one embodiment of the invention to provide a simple mathematically tractable formula for extracting student engagement from brainwave activity.
[0012] The dynamic threshold may be based on historical measures of the student's brain waves.
[0013] It is thus a feature of at least one embodiment of the invention to use the student's characteristic brain waves to “calibrate” the engagement signal and thus to provide a system that may better accommodate a range of different students.
[0014] Alternatively or in addition, the dynamic threshold may be based on a slope of decrease in the engagement signal.
[0015] It is thus a feature of at least one embodiment of the invention to provide a system for determining engagement with reduced sensitivity to absolute brainwave values such as may fluctuate for different educational materials and among students.
[0016] Alternatively or in addition the dynamic threshold may be based on a comparison of a slope in decrease in the engagement signal for two different time windows applied to the engagement signal.
[0017] It is thus a feature of at least one embodiment of the invention to provide a dynamic threshold that can de-emphasize minor short-term fluctuations in attention.
[0018] The educational program may be presented by a representation of a human speaker (for example an avatar or electromechanical robot) and the modification of the presentation may modify a gesture of the representation of the human speaker using hand movements.
[0019] It is thus a feature of at least one embodiment of the invention to tap into techniques naturally used by educators to bolster attention.
[0020] The hand movements may be selected from the categories of iconic, metaphoric, deictic, and beat gestures.
[0021] It is thus a feature of at least one embodiment of the invention to permit nuanced use of gesture such as provides an additional channel of communication.
[0022] The educational program may include an audio signal providing spoken text and the modification of the presentation modifies the audio signal. The audio signal may be modified by techniques including modification selected from the group consisting of changing a volume of the audio signal and augmenting the audio signal with nontext audio signals. When the educational program includes a video display, the modification of the presentation may provide camera effects to the video display selected from the group consisting of: change in camera angle, palming, shaking, zooming, and changing illumination.
[0023] It is thus a feature of at least one embodiment of the invention to provide a mechanism for promoting attention in environments where hand gestures may not be readily modified, for example, in a pre-recorded lecture by a human educator.
[0024] Alternatively or in addition the modification of the presentation may interrupt the presentation to require student input.
[0025] It is thus a feature of at least one embodiment of the invention to promote student attention by engaging the student for input.
[0026] The student input may provide a set of evaluation questions answered by the student.
[0027] It is thus a feature of at least one embodiment of the invention to employ a form of student input that may exercise recall of the information and that may provide for useful feedback for the computer based instruction system.
[0028] These particular objects and advantages may apply to only some embodiments falling within the claims and thus do not define the scope of the invention.
BRIEF DESCRIPTION OF THE FIGURES
[0029] FIG. 1 is a simplified perspective view of a computer-based education system suitable for use in the present invention providing a student with a brain monitoring headset interacting with educational software;
[0030] FIG. 2 is a block diagram of the computer system of FIG. 1 showing the elements of the computer system and its stored program and the brain-monitoring headset;
[0031] FIG. 3 is a simplified plot of an engagement signal versus time showing points of attention promoting intervention (API) according to a dynamic threshold implemented by the present invention;
[0032] FIG. 4 is a block diagram showing determination of the timing of API based on the monitoring of brain waves from the headset of FIGS. 1 and 2 ;
[0033] FIG. 5 is a plot similar to that of FIG. 3 showing the application of the processing of FIG. 5 to an example waveform measuring engagement;
[0034] FIG. 6 is a simplified flowchart of a program executed by the computer system of FIG. 2 interacting with educational software;
[0035] FIG. 7 is an example of API implemented on a video display providing a representation of a lecturer;
[0036] FIG. 8 is an example of alternative API for use with video displays; and
[0037] FIGS. 9 a - 9 c are examples of API implemented by a teaching robot.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0038] Referring now to FIG. 1 , a first embodiment of a computer-based educational system 10 employing the present invention may use a standard desktop computer system 12 providing, for example, a processing unit 15 , such as a multimedia personal computer, communicating with a display screen 14 for displaying text and images and communicating with speakers 16 or the like for providing audio programming. The computer system 12 may further include standard user input devices 18 such as a keyboard and mouse for accepting input from a student 20 using the desktop computer system 12 .
[0039] The student 20 may also be provided with a brain monitor 22 , for example, an EEG monitoring system. Such brain monitors 22 are available commercially under the tradename NeuroSky Mindset or Mindwave EEG monitors from NeuroSky of San Jose Calif. as well as other vendors. Alternatively the brain monitor 22 may be a functional near infrared imaging monitor deducing brain activity through measurement of blood oxygenation in the prefrontal cortex.
[0040] Referring to FIG. 2 , the processing unit 15 may include one or more processors 24 communicating on a common bus 26 . The bus 26 may connect the processors 24 to a variety of interfaces 36 of types well known in the art including those for connecting the processors 24 to the Internet 38 , the display screen 14 , the speakers 16 , the brain monitor 22 , and user input devices 18 . The bus 26 may also connect the processors 24 with a memory 28 including, for example, random access memory and disk storage. The memory 28 may hold an operating system 30 , educational program software 32 and an engagement monitoring program 34 to be described below.
[0041] The educational program software 32 in its simplest embodiment may provide for video and audio output duplicating the presentation of a human lecture albeit with the ability to interact with the engagement monitoring program 34 as will be described below. The invention is broadly applicable to a wide variety of different CBE programs including existing commercial programs with minor modification.
[0042] As noted, the brain monitor 22 may communicate with the processing unit 15 by an interface 36 , for example, communicating with a Bluetooth transceiver 42 in a circuitry unit 44 of the brain monitor 22 . The transceiver 42 may communicate with an internal processing unit 52 connected to a headset 46 . Headset 46 generally positions sensitive electrodes 50 in contact with the skin of the patient's scalp for the receipt of EEG signals which may be processed by an internal processing unit 52 for separation of the raw EEG signal into alpha, beta, and theta waves using high speed frequency domain processing (such as the fast Fourier transform) generally understood in the art. The amplitude of the alpha, beta, and theta waves is transmitted to the interface 36 to the processing unit 15 for use by the program 34 .
[0043] Referring now to FIGS. 2 and 3 , generally the educational program software 32 will present an educational program to the student 20 and the enhancement program 34 will monitor the student's brain waves to deduce an engagement level 54 during the time of the presentation. The engagement level will be compared against a dynamically determined threshold level 56 to identify effective timing of attention-promoting intervention (API) points 58 at various times during the presentation. At the times of these API points 58 , the enhancement program 34 will communicate with the educational program software 32 to modify the output of the educational program software 32 to provoke increased engagement by the student 20 .
[0044] Referring now to FIG. 5 , to this end, the enhancement program 34 may receive magnitude readings of the student's alpha waves, beta waves and theta waves from the brain monitor 22 as indicated by channels 60 . As is generally understood in the art, theta waves are EEG signals generally from 4 to 7 Hz, alpha waves are EEG signals generally from 8 to 12 Hz and beta waves are EEG signals generally from 13 to 30 Hz.
[0045] Each of these time varying scalar values are then processed by an exponentially weighted moving average filter 62 giving greatest weighting to most recent values according to the formula:
[0000]
S
(
t
)
=
{
Y
(
t
)
:
:=
1
a
*
Y
(
t
-
1
)
+
(
1
-
a
)
*
S
(
t
-
1
)
:
t
>
1.
(
1
)
[0000] where S(t) is the smoothed value, Y(t) is the raw EEG signal as a function of sample time t, and “a” is a regularization constant controlling the de-weighting of past values in favor of more recent values. In the experiment described below a value equal to 0.015 was used.
[0046] The EEG values are then combined to produce an engagement value E(t) per process block 64 as follows:
[0000]
E
=
β
(
α
+
θ
)
(
2
)
[0000] where the letters in the fraction represent the alpha, beta, and theta waveforms from the brain monitor 22 .
[0047] The engagement signal is then processed on a regular processing interval (e.g. 15 seconds) to evaluate a derivative threshold DT indicated by process block 66 to produce a binary value of zero or one according to the formula:
[0000]
DT
(
E
)
=
{
1
:
E
(
x
)
_
t
<
E
(
y
)
_
t
,
E
(
x
)
_
t
<
0
0
:
otherwise
(
3
)
[0000] where
[0000]
E
(
y
)
_
t
[0000] represents the average slope of the engagement signal E(t) seen so far (as stored by buffer 65 ) and
[0000]
E
(
x
)
_
t
[0000] is the average slope of the current interval in the engagement signal.
[0048] The engagement signal E(t) is also processed on the given processing interval to evaluate two least square regression values indicated by process block 68 and 70 which minimizes the function F as follows:
[0000]
F
=
∑
i
=
1
n
(
y
i
-
(
ax
i
+
b
i
)
)
2
(
4
)
∂
F
∂
a
=
0
and
∂
F
∂
b
=
0
(
5
)
[0049] In this case, y and x represent the ordinate and abscissa of the function F in distinction from the previous example where y indicates storable data. F provides a straight line fit to E having a slope “a” and intercept “b”.
[0050] A first least square regression value as defined above is calculated per process block 68 based on the processing interval of engagement data whereas the second least square regression value per process block 70 is based on all of engagement data available so far during the educational program (or more generally a longer time window than the processing interval, for example, of one half hour).
[0051] The two values of the least square regression from process blocks 68 and 70 are combined by weighting block 72 to produce a threshold value T according to the formula:
[0000] T= 0.05* F ( y ) +0.95* F ( x ) (6)
[0052] Referring also to FIG. 6 , if the current engagement value E(t) is below this threshold T, as determined by comparator 74 , and the output value of process block 66 is “one” and there has not been API point 58 output in the last processing interval (as indicated by feedback timer 76 ), as determined by AND block 78 , then API point 58 is output triggering modification of the presentation of the educational material by the educational presentation program 34 to provoke increased attention by the student 20 (shown in FIGS. 1 and 2 ).
[0053] Referring now to FIG. 7 , as noted, the present invention operates in tandem with the presentation of an educational program by the educational program software 32 , the latter presentation indicated by process block 82 , where the engagement monitoring program 34 periodically checks, as indicated at decision block 84 , for example on the processing interval, whether API points 58 should occur. If so the API points 58 are implemented as indicated by process block 86 , as will be described below, otherwise the program returns to process block 82 .
[0054] Referring now to FIG. 8 , one form of responding to the API points 58 may be in the generation of nonverbal immediacy cues by a computerized avatar 92 presenting a lecture on the display screen 14 . These nonverbal immediacy cues may include, for example, hand gestures that will be described below. Alternatively or in addition, other modifications to the video and audio presentation through the computer system 12 may be used to implement the API points 58 including change in volume of the audio program, brightening or dimming the screen display, or providing a separate graphic indicator 96 , for example, an LED or the like providing feedback with respect to the student's attention. API points 58 may also be implemented in a prerecorded video lecture, as shown in FIG. 9 , by applying video effects 100 including, for example, panning, shaking, brightening or darkening, highlighting or zooming or the like to the prerecorded image. A similar effect can be obtained with changes in camera angle when multiple cameras are used to record a live lecture. The API points 58 may also be implemented by change of presentation or the introduction of a quiz or summary.
[0055] Referring now to FIG. 10 a - c, in one embodiment, the educational program may be delivered through a humanoid robot 88 having articulated arms and hands 90 to make nonverbal immediacy cues in response to the API points 58 . Research into gestures suggests that people use four major categories of gestures in human-human interactions: (1) iconic, (2) metaphoric, (3) deictic, and (4) beat gestures. Iconic gestures are closely related to the content of speech and represent concrete events and objects, for example, raising one's hands to indicate “higher”. Metaphoric gestures allow the speaker to represent abstract concepts, such as moving one's hands in a circle to describe a cycle per FIG. 10 b. Deictic gestures direct attention towards things directly around the speaker or to the parties in the interaction, such as pointing at one's self or the listener to highlight a self-experience per FIG. 10 a. Beat gestures allow the speaker to emphasize certain words and phrases and may also be linked with internal processes in speech formulation, for example, rhythmic arm motion per FIG. 10 c. The present invention may use any of these gestures as an immediacy cue which may be delivered without interference with verbal delivery by the humanoid robot 88 by the calling of separate arm control scripts at the times of the API points 58 .
Example I
[0056] To investigate the effects of EEG-triggered adaptive immediacy cues in educational outcomes, a laboratory experiment was conducted in which participants received instruction from a humanlike robot. This experiment provided a 3×1 between-participants study in which immediacy cues displayed by a Wakamaru humanlike robot were manipulated as it told participants two narrative stories. The independent variable was the introduction of the immediacy cues and included three levels: (1) low immediacy, (2) immediacy cues at random intervals, and (3) “adaptive” cues triggered by drops in the participants' EEG-measured engagement levels determined by the dynamic thresholding process described above. The dependent variables included participants' recall of the details of the stories, self-reported learning, and EEG signals (used in post-hoc analysis to confirm that interventions successfully halted downward trends in student attention).
Experimental Procedure
[0057] In the study, each participant was presented with a memory task that assessed the participant's recall of the details of a story narrated by the robotic teacher. After signing a consent form and being given a brief description of the experiment, participants were brought into a controlled room. Here the researcher aided the participant in putting on the wireless EEG headset and ensured good connectivity. Once the headset connection was established, the researcher left the room and the participant started interacting with the robotic instructor. The human-robot interaction scenario consisted of five main phases: (1) introduction, (2) calibration, (3) learning, (4) distractor, and (5) evaluation, during which the robot spoke using a pre-recorded female voice modulated to a gender-neutral tone.
[0058] First, the robot introduced itself and asked if the participant had any prior knowledge of the story behind the twelve signs of the Chinese Zodiac.
[0059] Second, the robot then told a pre-scripted three-minute long story about the determination of animals in the Chinese Zodiac, which was used to get baseline EEG readings that were used to build the derivative and LSR thresholds. During this calibration phase, the robot maintained “eye” contact with the user by following the users head movements to make the conversation appear more natural, but did not employ other immediacy cues regardless of experimental condition. Both this and the next story used in the learning stage were chosen for their unfamiliarity to the participant population in order to ensure that participants had no prior task knowledge.
[0060] Third, in the learning phase, the robot narrated a longer ten-minute story based on the popular Japanese folk tale “My Lord Bag of Rice.” During this story, robot-participant immediacy was manipulated according to experimental condition. In the adaptive condition, the robot displayed adaptive immediacy cues by increasing its volume and employing arm gestures when a drop in engagement was identified by monitoring the participants' real-time EEG engagement data. In the random immediacy cue condition, the robot raised the volume of its voice and produced arm gestures at random intervals, the number of which was determined by the number of cues made by the instructor in the last experimental trial in the adaptive condition. In the low immediacy category, the robot told the second story in the same way it told the first story, ignoring any lapses in participant attention, although still using gaze and natural head movements that were controlled autonomously to ensure consistency between participants. While displaying an immediacy cue, the robot suspended its head movement and looked toward the participant.
[0061] Fourth, after the learning phase, the robot asked the participant four questions about the Chinese Zodiac story as a distractor task which ensured that there was a break between the learning and evaluation phases for the second story.
[0062] Fifth, in the last phase, the robot presented the participant with fourteen questions about the longer story to evaluate the participants' recall ability. During this question-answer period, the time between questions was controlled by the researcher behind the scenes to account for varying answer times.
[0063] Following these questions, the experimenter re-entered the room and had the participant remove the headset and fill out a post-experiment questionnaire to obtain a subjective evaluation of participant experience. Finally, participants were debriefed by the researcher and were compensated $5 for their time.
[0064] A total of 30 participants (15 males and 15 females) took part in this experiment. Each of the three conditions had an equal number of participants (five males and five females). All participants were native English speakers and recruited from the University of Wisconsin—Madison campus. The average age was 22.3 (SD=6.88) with a range of 18-57. Prior familiarity with robots was low (M=3.23, SD=1.55) as was their familiarity with the story in the task (M=1.37, SD=1.07) in a scale of one to seven.
[0065] Objective measurements included fourteen questions that measured the participants' ability to recall the details of the “My Lord Bag of Rice” story and the participants' EEG data.
Manipulation Checks
[0066] Three different checks were made to verify the manipulations. First, examining the EEG data of participants in the low immediacy condition was used to confirm that the engagement monitoring technique successfully identified drops in attention. Second, the EEG data of participants in the random and adaptive immediacy conditions was analyzed to ensure that the robot's behaviors had a positive effect on student engagement. Finally, a five-item scale was constructed from participant responses to the post-experiment questionnaire to assess whether or not the manipulations of the robot's immediacy behavior were successful. The items asked participants how much the robot emphasized parts of story, tried to get their attention, varied the volume of its speech, used gestures, and tried to get their attention when they grew bored (Cronbach's α=0.756).
[0067] An analysis of variance (ANOVA) was used to analyze the data from manipulation checks and objective measurements. To verify that the system was working correctly, the EEG data for participants in the low immediacy condition was processed using the above-described techniques to identify times when the instructor would have used immediacy cues had those participants been in the adaptive condition. Engagement levels were then analyzed in the 30-second timeframes before and after each possible cue using a two-way repeated measures ANOVA using participant ID as a random effect and condition, time frame, and the interaction of the two as fixed effects. This analysis found that average engagement levels 30 seconds prior to when engagement monitoring system would have directed the robot to re-engage the participant were significantly higher than the average engagement levels 30 seconds after this time, F(1, 658.5)=7.54, p=0.006, suggesting that this dynamic threshold technique was correctly identifying losses of engagement. Further EEG analysis yielded no significant differences in the 30-second windows before and after the robot employed behavioral strategies to regain attention in the random, F(1, 658.5)=0.116, p=0.734, and adaptive, F(1, 658.5)=2.41 p=0.121, conditions, showing that robot immediacy cues successfully halted downward engagement levels.
Objective Results
[0068] The analysis confirmed that participants who received targeted immediacy cues triggered by a drop in EEG-monitored engagement levels had better recall of the story than other participants. The number of correct answers out of fourteen questions was on average 6.30 (SD=3.40), 7.44 (SD=1.94), and 9.00 (SD=1.76) in the low immediacy, random immediacy, and adaptive immediacy conditions, respectively. These results showed that participants with an adaptive instructor outperformed the random condition by 23% and the low immediacy baseline by 43% with a significant difference between the low and adaptive immediacy levels, F(1, 27)=5.87, p=0.022, η p 2 =0.177, regardless of gender. No significant difference was found between the low and random conditions, F(1, 27)=0.652, p=0.426, η p 2 =0.024, or between random and adaptive conditions, F(1, 27)=2.60, p=0.118, η p 2 =0.088. A pairwise comparison, which contrasted the adaptive condition with the random and low immediacy conditions, revealed significantly improved recall accuracy in students with an adaptive instructor, F(1, 27)=5.43, p=0.028, η p 2 =0.164. Much of the variance in the model came from gender as well as users' prior familiarity with robots. When these factors were controlled for, the analysis showed even a greater difference between information recall scores in the adaptive immediacy condition and the combined scores in the low and random immediacy conditions, F(1, 21)=7.89, p=0.003, η p 2 =0.291.
[0069] It will be appreciated that the term “engagement signal” generally refers to a signal that indicates the engagement or attention or alertness of the student, and the term “engagement” in isolation should not be considered limiting. Certain terminology is used herein for purposes of reference only, and thus is not intended to be limiting. For example, terms such as “upper”, “lower”, “above”, and “below” refer to directions in the drawings to which reference is made. Terms such as “front”, “back”, “rear”, “bottom” and “side”, describe the orientation of portions of the component within a consistent but arbitrary frame of reference, which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms “first”, “second” and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context.
[0070] When introducing elements or features of the present disclosure and the exemplary embodiments, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of such elements or features. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements or features other than those specifically noted. It is further to be understood that the method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
[0071] References to “a microprocessor” and “a processor” or “the microprocessor” and “the processor,” can be understood to include one or more microprocessors that can communicate in a stand-alone and/or a distributed environment(s), and can thus be configured to communicate via wired or wireless communications with other processors, where such one or more processor can be configured to operate on one or more processor-controlled devices that can be similar or different devices. Furthermore, references to memory, unless otherwise specified, can include one or more processor-readable and accessible memory elements and/or components that can be internal to the processor-controlled device, external to the processor-controlled device, and can be accessed via a wired or wireless network.
[0072] It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein and the claims should be understood to include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims. All of the publications described herein, including patents and non-patent publications, are hereby incorporated herein by reference in their entireties. | A computer-based education system monitors brain activity of the student to produce an “engagement” signal that may be compared against a dynamic threshold to identify a plurality of points demarcating periods of declining attention. These points are used to trigger modifications to the presentation of the educational program to promote student retention of the present information. | 0 |
STATUS OF RELATED APPLICATIONS
This application is a continuation-in-part of U.S. Ser. No. 13/027,314, filed Feb. 15, 2011, now issued into U.S. Pat. No. 8,709,993. This application is also a continuation-in-part of U.S. Ser. No. 13/540,894, filed Jul. 3, 2012, now issued into U.S. Pat. No. 8,557,876, which is a continuation-in-part of U.S. Ser. No. 13/430,908, filed Mar. 27, 2012, now issued into U.S. Pat. No. 8,557,827, which is a continuation-in-part of U.S. Ser. No. 13/027,314, filed Feb. 15, 2011, now issued into U.S. Pat. No. 8,709,993, the contents hereby incorporated by reference as if set forth in its entirety.
FIELD OF THE INVENTION
The present invention relates to new chemical entities and the incorporation and use of the new chemical entities as fragrance materials.
BACKGROUND OF THE INVENTION
There is an ongoing need in the fragrance industry to provide new chemicals to give perfumers and other persons the ability to create new fragrances for perfumes, colognes and personal care products. Those with skill in the art appreciate how differences in the chemical structure of the molecule can result in significant differences in the odor, notes and characteristics of a molecule. These variations and the ongoing need to discover and use the new chemicals in the development of new fragrances allow the perfumers to apply the new compounds in creating new fragrances.
SUMMARY OF THE INVENTION
The present invention provides novel compounds and their unexpected advantageous use in enhancing, improving or modifying the fragrance of perfumes, colognes, toilet water, fabric care products, personal products and the like.
More specifically, the present invention relates to pyrimidine derivatives represented by Formula I set forth below:
wherein m and n are integers of 0 or 1 with the proviso that when m is 0, n is 1 and when m is 1, n is 0; and
wherein the dashed circle represents either single or double bonds.
Another embodiment of the present invention relates to pyrimidine derivatives represented by Formula II set forth below:
wherein the dashed circle represents either single or double bonds.
Another embodiment of the present invention relates to a fragrance composition comprising the novel compounds provided above.
Another embodiment of the present invention relates to a fragrance product comprising the compounds provided above.
Another embodiment of the present invention relates to a method of improving, enhancing or modifying a fragrance formulation through the addition of an olfactory acceptable amount of the novel compounds provided above.
These and other embodiments of the present invention will be apparent by reading the following specification.
DETAILED DESCRIPTION OF THE INVENTION
The compounds of the present invention may be represented by the following structures:
Those with the skill in the art will appreciate that
Formula III is 7,7,8,9,9-pentamethyl-8,9-dihydro-7H-cyclopenta[H]quinazoline;
Formula IV is 7,7,8,9,9-pentamethyl-6,6A,7,8,9,9A-hexahydro-5H-cyclopenta(F)quinazoline; and
Formula V is 6,6,7,8,8-pentamethyl-5A,6,7,8,8A,9-hexahydro-5H-cyclopenta(G)quinazoline.
Those with skill in the art will recognize that the compounds of the present invention contain chiral centers, thereby providing a number of isomers of the claimed compounds. It is intended herein that the compounds described herein include isomeric mixtures of such compounds, as well as those isomers that may be separated using techniques known to those having skill in the art. Suitable techniques include chromatography such as high performance liquid chromatography, referred to as HPLC, and particularly silica gel chromatography and gas chromatography trapping known as GC trapping. Yet, commercial products are mostly offered as isomeric mixtures.
The preparation of the compounds of the present invention is detailed in the Examples. Materials were purchased from Aldrich Chemical Company unless noted otherwise.
The use of the compounds of the present invention is widely applicable in current perfumery products, including the preparation of perfumes and colognes, the perfuming of personal care products such as soaps, shower gels, and hair care products, fabric care products, air fresheners, and cosmetic preparations. The present invention can also be used to perfume cleaning agents, such as, but not limited to detergents, dishwashing materials, scrubbing compositions, window cleaners and the like.
In these preparations, the compounds of the present invention can be used alone or in combination with other perfuming compositions, solvents, adjuvants and the like. The nature and variety of the other ingredients that can also be employed are known to those with skill in the art. Many types of fragrances can be employed in the present invention, the only limitation being the compatibility with the other components being employed. Suitable fragrances include but are not limited to fruits such as almond, apple, cherry, grape, pear, pineapple, orange, strawberry, raspberry; musk, flower scents such as lavender-like, rose-like, iris-like, carnation-like. Other pleasant scents include herbal and woodland scents derived from pine, spruce and other forest smells. Fragrances may also be derived from various oils, such as essential oils, or from plant materials such as peppermint, spearmint and the like.
A list of suitable fragrances is provided in U.S. Pat. No. 4,534,891, the contents of which are incorporated by reference as if set forth in its entirety. Another source of suitable fragrances is found in Perfumes, Cosmetics and Soaps , Second Edition, edited by W. A. Poucher, 1959. Among the fragrances provided in this treatise are acacia, cassie, chypre, cyclamen, fern, gardenia, hawthorn, heliotrope, honeysuckle, hyacinth, jasmine, lilac, lily, magnolia, mimosa, narcissus, freshly-cut hay, orange blossom, orchid, reseda, sweet pea, trefle, tuberose, vanilla, violet, wallflower, and the like.
The compounds of the present invention can be used in combination with a complementary fragrance compound. The term “complementary fragrance compound” as used herein is defined as a fragrance compound selected from the group consisting of 2-[(4-methylphenyl)methylene]-heptanal (Acalea), iso-amyl oxyacetic acid allylester (Allyl Amyl Glycolate), (3,3-dimethylcyclohexyl)ethyl ethyl propane-1,3-dioate (Applelide), (E/Z)-1-ethoxy-1-decene (Arctical), 2-ethyl-4-(2,2,3-trimethyl-3-cyclo-penten-1-yl)-2-buten-1-ol (Bacdanol), 2-methyl-3-[(1,7,7-trimethylbicyclo[2.2.1]hept-2-yl)oxy]exo-1-propanol (Bornafix), 1,2,3,5,6,7-hexahydro-1,1,2,3,3-pentamethyl-4H-inden-4-one (Cashmeran), trimethylcyclopentenylmethyloxabicyclooctane (Cassiffix), 1,1-dimethoxy-3,7-dimethyl-2,6-octadiene (Citral DMA), 3,7-dimethyl-6-octen-1-ol (Citronellol), 3A,4,5,6,7,7A-hexahydro-4,7-methano-1H-inden-5/6-yl acetate (Cyclacet), 3A,4,5,6,7,7A-hexahydro-4,7-methano-1H-inden-5/6-yl propinoate (Cyclaprop), 3A,4,5,6,7,7A-hexahydro-4,7-methano-1G-inden-5/6-yl butyrate (Cyclobutanate), 1-(2,6,6-trimethyl-3-cyclohexen-1-yl)-2-buten-1-one (Delta Damascone), 3-(4-ethylphenyl)-2,2-dimethyl propanenitrile (Fleuranil), 3-(O/P-ethylphenyl) 2,2-dimethyl propionaldehyde (Floralozone), tetrahydro-4-methyl-2-(2-methylpropyl)-2H-pyran-4-ol (Floriffol), 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-gamma-2-benzopyran (Galaxolide), 1-(5,5-dimethyl-1-cyclohexen-1-yl)pent-4-en-1-one (Galbascone), E/Z-3,7-dimethyl-2,6-octadien-1-yl acetate (Geranyl Acetate), α-methyl-1,3-benzodioxole-5-propanal (Helional), 1-(2,6,6-trimethyl-2-cyclohexen-1-yl)-1,6-heptadien-3-one (Hexylon), (Z)-3-hexenyl-2-hydroxybenzoate (Hexenyl Salicylate, CIS-3), 4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-3-buten-2-one (Ionone α), 1-(1,2,3,4,5,6,7,8-octahydro-2,3,8,8-tetramethyl-2-naphthalenyl)-ethan-1-one (Iso E Super), methyl 3-oxo-2-pentylcyclopentaneacetate (Kharismal), 2,2,4-trimethyl-4-phenyl-butanenitrile (Khusinil), 3,4,5,6,6-pentamethylhept-3-en-2-one (Koavone), 3/4-(4-hydroxy-4-methyl-pentyl)cyclohexene-1-carboxaldehyde (Lyral), 3-methyl-4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-3-buten-2-one (Methyl Ionone γ), 1-(2,6,6-trimethyl-2-cyclohexen-1-yl) pent-1-en-3-one (Methyl Ionone α Extra, Methyl Ionone N), 3-methyl-4-phenylbutan-2-ol (Muguesia), cyclopentadec-4-en-1-one (Musk Z4), 3,3,4,5,5-pentamethyl-11,13-dioxatricyclo[7.4.0.0<2,6>]tridec-2(6)-ene (Nebulone), 3,7-dimethyl-2,6-octadien-1-yl acetate (Neryl Acetate), 3,7-dimethyl-1,3,6-octatriene (Ocimene), ortho-tolylethanol (Peomosa), 3-methyl-5-phenylpentanol (Phenoxanol), 1-methyl-4-(4-methyl-3-pentenyl)cyclohex-3-ene-1-carboxaldehyde (Precyclemone B), 4-methyl-8-methylene-2-adamantanol (Prismantol), 2-ethyl-4-(2,2,3-trimethyl-3-cyclopenten-1-yl)-2-buten-1-ol (Sanjinol), 2-methyl-4-(2,2,3-trimethyl-3-cyclopenten-1-yl)-2-buten-1-ol (Santaliff), Terpineol, 2,4-dimethyl-3-cyclohexene-1-carboxaldehyde (Triplal), decahydro-2,6,6,7,8,8-hexamethyl-2H-indeno[4,5-B]furan (Trisamber), 2-tert-butylcyclohexyl acetate (Verdox), 4-tert-butylcyclohexyL acetate (Vertenex), acetyl cedrene (Vertofix), 3,6/4,6-dimethylcyclohex-3-ene-1-carboxaldehyde (Vertoliff), and (3Z)-1-[(2-methyl-2-propenyl)oxy]-3-hexene (Vivaldie).
The terms “fragrance formulation”, “fragrance composition”, and “perfume composition” mean the same and refer to a consumer composition that is a mixture of compounds including, for example, alcohols, aldehydes, ketones, esters, ethers, lactones, nitriles, natural oils, synthetic oils, and mercaptans, which are admixed so that the combined odors of the individual components produce a pleasant or desired fragrance. The fragrance formulation of the present invention is a consumer composition comprising a compound of the present invention. The fragrance formulation of the present invention comprises a compound of the present invention and further a complementary fragrance compound as defined above.
The term “fragrance product” means a consumer product that adds a fragrance or masks a malodor. Fragrance products may include, for example, perfumes, colognes, personal care products such as soaps, shower gels, and hair care products, fabric products, air fresheners, cosmetic preparations, and perfume cleaning agents such as detergents, dishwashing materials, scrubbing compositions, and window cleaners. The fragrance product of the present invention is a consumer product that contains a compound of the present invention. The fragrance product of the present invention contains a compound of the present invention and further a complementary fragrance compound as defined above.
The term “improving” in the phrase “improving, enhancing or modifying a fragrance formulation” is understood to mean raising the fragrance formulation to a more desirable character. The term “enhancing” is understood to mean making the fragrance formulation greater in effectiveness or providing the fragrance formulation with an improved character. The term “modifying” is understood to mean providing the fragrance formulation with a change in character.
The term “olfactory acceptable amount” is understood to mean the amount of a compound in a fragrance formulation, wherein the compound will contribute its individual olfactory characteristics. However, the olfactory effect of the fragrance formulation will be the sum of effect of each of the fragrance ingredients. Thus, the compound of the present invention can be used to improve or enhance the aroma characteristics of the fragrance formulation, or by modifying the olfactory reaction contributed by other ingredients in the formulation. The olfactory acceptable amount may vary depending on many factors including other ingredients, their relative amounts and the olfactory effect that is desired.
The amount of the compounds of the present invention employed in a fragrance formulation varies from about 0.005 to about 70 weight percent, preferably from 0.005 to about 50 weight percent, more preferably from about 0.5 to about 25 weight percent, and even more preferably from about 1 to about 10 weight percent. Those with skill in the art will be able to employ the desired amount to provide desired fragrance effect and intensity. In addition to the compounds of the present invention, other materials can also be used in conjunction with the fragrance formulation. Well known materials such as surfactants, emulsifiers, polymers to encapsulate the fragrance can also be employed without departing from the scope of the present invention.
When used in a fragrance formulation these ingredients provide additional notes to make a fragrance formulation more desirable and noticeable, and add the perception of value. The odor qualities found in these materials assist in beautifying and enhancing the finished accord as well as improving the performance of the other materials in the fragrance.
The following are provided as specific embodiments of the present invention. Other modifications of this invention will be readily apparent to those skilled in the art. Such modifications are understood to be within the scope of this invention. As used herein all percentages are weight percent unless otherwise noted, ppm is understood to stand for parts per million, L is understood to be liter, mL is understood to be milliliter, g is understood to be gram, Kg is understood to be kilogram, and mmHg be millimeters (mm) of mercury (Hg). IFF as used in the examples is understood to mean International Flavors & Fragrances Inc., New York, N.Y., USA.
Example I
Preparation of 7,7,8,9,9-Pentamethyl-8,9-dihydro-7H-cyclopenta[H]quinazoline (Formula III)
7,7,8,9,9-Pentamethyl-6,7,8,9-tetrahydro-5H-cyclopenta[H]quinazoline was prepared as described in EXAMPLE I of U.S. Publication No. 2012/0207697 and in EXAMPLE I of U.S. Publication No. 2012/0277325. A 3-L reaction vessel was charged with 7,7,8,9,9-pentamethyl-6,7,8,9-tetrahydro-5H-cyclopenta[H]quinazoline (1 Kg) and sulfuric acid (H 2 SO 4 ) (100 g). The reaction mixture was heated to 220° C. for 12 hours and then cooled to 80° C. The resulting mixture was diluted with toluene (1 L). The organic layer was separated and washed twice with brine (2 L), twice with aqueous sodium hydroxide (NaOH) (25%, 2 L) and then twice with brine (2 L). The crude product was purified by vacuum distillation to afford 7,7,8,9,9-Pentamethyl-8,9-dihydro-7H-cyclopenta[H]quinazoline (992 g) having a boiling point of 160° C. at 1.0 mmHg. Further recrystallization from ethanol afforded a solid with a melting point of 84.0° C.
1 HNMR (CDCl 3 , 500 MHz): 9.30 ppm (s, 1H), 9.29 ppm (s, 1H), 7.74 ppm (d, 1H, J=8.28 Hz), 7.47 ppm (d, 1H, J=8.28 Hz), 2.02 ppm (q, 1H, J=7.36 Hz), 1.74 ppm (s, 3H), 1.39 ppm (s, 3H), 1.37 ppm (s, 3H), 1.10 ppm (s, 3H), 1.06 ppm (d, 3H, J=7.36 Hz),
7,7,8,9,9-Pentamethyl-8,9-dihydro-7H-cyclopenta[H]quinazoline was described as having musky, creamy, sweet and warm notes.
Example II
Preparation of 7,7,8,9,9-Pentamethyl-6,6A,7,8,9,9A-hexahydro-5H-cyclopenta(F)quinazoline (Formula IV) and 6,6,7,8,8-Pentamethyl-5A,6,7,8,8A,9-hexahydro-5H-cyclopenta(G)quinazoline (Formula V)
A 100 mL reaction flask was charged with 1,1,2,3,3-pentamethyl-1,2,3,5,6,7-hexahydro-inden-5-one (10 g) (prepared as described in U.S. Pat. No. 3,767,713), formamidine acetate (HN═CHNH 2 .CH 3 COOH) (25 g) and butanol (C 4 H 9 OH) (120 mL). Boron triflouride (BF 3 ) (3 g) was added. The reaction mixture was then heated to 140° C. and stirred for 3 hours. The crude mass was washed once with aqueous sulfuric acid (H 2 SO 4 ) (10%, 100 mL) followed by twice with brine (30 mL). Butanol was recovered by roto-evaporation. The crude product was further purified with liquid chromatography followed by crystallization to afford a mixture of 7,7,8,9,9-Pentamethyl-6,6A,7,8,9,9A-hexahydro-5H-cyclopenta(F)quinazoline (Formula IV) and 6,6,7,8,8-Pentamethyl-5A,6,7,8,8A,9-hexahydro-5H-cyclopenta(G)quinazoline (Formula V) in a ratio of about 1:1 (1.1 g). Products were separated and confirmed by NMR analysis with GC trapping. 7,7,8,9,9-Pentamethyl-6,6A,7,8,9,9A-hexahydro-5H-cyclopenta(F)quinazo line:
1 H NMR (CDCl 3 , 500 MHz): 8.92 ppm (s, 1H), 8.64 ppm (s, 1H), 2.99 ppm (d, 1H, J=8.51 Hz), 2.91-2.99 ppm (m, 2H), 2.05-2.13 ppm (m, 1H), 1.89-1.96 ppm (m, 1H), 1.65-1.78 ppm (m, 1H), 1.60 ppm (q, 1H, J=7.0 Hz), 1.22 ppm (s, 3H), 1.11 ppm (s, 3H), 0.85 ppm (d, 3H, J=7.0 Hz), 0.94 ppm (s, 3H), 0.54 ppm (s, 3H)
7,7,8,9,9-Pentamethyl-6,6A,7,8,9,9A-hexahydro-5H-cyclopenta(F)quinazoline was described as having ambery, musky and fruity notes.
6,6,7,8,8-Pentamethyl-5A,6,7,8,8A,9-hexahydro-5H-cyclopenta(G)quinazoline:
1 H NMR (CDCl 3 , 500 MHz): 8.93 ppm (s, 1H), 8.37 ppm (s, 1H), 2.85 ppm (d, 1H, J=15.0 Hz, of d, J=6.46 Hz), 2.61-2.73 ppm (m, 2H), 2.48 ppm (d, 1H, J=14.7 Hz, of d, J=11.50 Hz), 1.97-2.10 ppm (m, 2H), 1.54 ppm (q, 1H, J=7.27 Hz), 1.03 ppm (s, 3H), 1.01 ppm (s, 3H), 0.88 ppm (s, 3H), 0.87 ppm (d, 3H, J=7.27 Hz), 0.86 ppm (s, 3H)
6,6,7,8,8-Pentamethyl-5A,6,7,8,8A,9-hexahydro-5H-cyclopenta(G)quinazoline was described as having ambery, musky and fruity notes.
Example III
Preparation of 6,7,8,9-Tetrahydro-7,7,8,9,9-pentamethyl-5H-cyclopenta[H]quinazoline (Formula VI), 6,6a,7,8,9,9a-Hexahydro-7,7,8,9,9-pentamethyl-5H-cyclopenta[H]quinazoline (Formula VII) and 1,1,3,3-Tetramethyl-2,3,4,5-tetrahydro-1H-7,9-diaza-cyclopenta[a]naphthalene (Formula VIII)
6,7,8,9-Tetrahydro-7,7,8,9,9-pentamethyl-5H-cyclopenta[H]quinazoline (Formula VI) and 6,6a,7,8,9,9a-hexahydro-7,7,8,9,9-pentamethyl-5H-cyclopenta[H]quinazoline (Formula VII) were prepared according to the disclosure of U.S. Publication No. 2012/0207697. 1,1,3,3-Tetramethyl-2,3,4,5-tetrahydro-1H-7,9-diaza-cyclopenta[a]naphthalene (Formula VIII) was prepared according to the disclosure of U.S. Publication No. 2012/0277325.
Example IV
The fragrance properties of the above compounds (i.e., Formulas III-VIII) were evaluated using (i) odor strength of 0 to 10, where 0=none, 1=very weak, 5=moderate, 10=extremely strong; and (ii) level of complexity, where 0=none, 1=very low, 5=moderate, 10=extremely high. Averaged scores are reported in the following:
Chemical Name
Compound
Odor Profile
Strength
Complexity
7,7,8,9,9-Pentamethyl-8,9- dihydro-7H- cyclopenta[H]quinazoline (Formula III)
Powerful and complex with warm, musky and sensual combination. Having a very bright top note supported by warm woody background and overall sweetness. As it dried down, the note was more apparent and complex with muskiness, woodiness and
9
9
sweetness, which became
the predominant features.
6,7,8,9-Tetrahydro- 7,7,8,9,9-pentamethyl-5H- cyclopcnta[H]quinazoline (Formula VI)
Having a musky note supported by an ambery feature, which provided additional strength and dimension.
9
9
6,6a,7,8,9,9a-Hexahydro- 7,7,8,9,9-pentamethyl-5H- cyclopenta[H]quinazoline (Formula VII)
Having an ambery note supported by a musky feature, which was further supported by woody and creamy notes that added complexity.
8
8
1,1,3,3-Tetramethyl-2,3,4,5- tetrahydro-1H-7,9-diaza- cyclopenta[a]naphthalene (Formula VIII)
Having a musky note supported by a woody feature but less interesting, weak and not clean.
4
4
7,7,8,9,9-Pentamethyl- 6,6A,7,8,9,9A-hexahydro- 5H- cyclopenta(F)quinazoline (Formula IV); and 6,6,7,8,8-Pentamethyl- 5A,6,7,8,8A,9-hexahydro- 5H- cyclopenta(G)quinazoline (Formula V) (1:1)
Ambery, musky and fruity but weak without copmplexity.
2
2
Formula III exhibited powerful, complex and desirable odors, which were however distinct from the odors of Formulas VI and VII and superior in strength and complexity to the odors of Formulas IV, V and VIII. | The present invention relates to novel pyrimidine derivatives and their use in perfume compositions. The novel pyrimidine derivatives of the present invention are represented by the following formula:
wherein m and n are integers of 0 or 1, with the proviso that when m is 0, n is 1 and when m is 1, n is 0; and
wherein the dashed circle represents either single or double bonds. | 2 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a non-volatile static random access memory circuit, and more particularly to a non-volatile static random access memory circuit without a storage mode and a recall mode.
[0003] 2. Description of the Related Art
[0004] Semiconductor memory devices are widely used in computers and other electronics products to store digital information. A typical semiconductor memory device has a large number of memory elements, known as memory cells, that are each capable of storing a single digital bit or data bit. Among several types of semiconductor memory devices, a non-volatile state random access memory device has high accessing speed. Moreover, when the power supply of the non-volatile state random access memory device is off, the previously stored data does not lost. Accordingly, in the power-off state or the standby mode, the power supply of the non-volatile state random access memory device can be cut off completely without concerning the data storage issue, thereby reducing power consumption.
[0005] Generally, before a conventional non-volatile state random access memory device enters the power-off state or the standby mode, the non-volatile state random access memory device has to operate in a storage mode to store data in a non-volatile memory element from a latch. After the power supply of the non-volatile state random access memory device is on, the non-volatile state random access memory device has to operate in a recall mode to recall the data from the on-volatile memory element to the latch. However, storage mode and the recall mode cause extra timing.
BRIEF SUMMARY OF THE INVENTION
[0006] It is desirable to provide a non-volatile static random access memory circuit which required no storage mode and no recall mode when a power-off state or a standby mode occurs.
[0007] An exemplary embodiment of a non-volatile static random access memory circuit is provided. The non-volatile static random access memory circuit comprises a first switch, a second switch, and a latch circuit. The first switch has a first terminal coupled to a first bit line and further having a second terminal. The second switch has a first terminal coupled to a second bit line and further having a second terminal. The latch circuit is coupled to the second terminal of the first switch and the second terminal of the second switch. The latch circuit has a first non-volatile memory element. When the non-volatile, static random access memory circuit is at a writing mode, first input data on the first bit line is written into the latch circuit, and the first non-volatile memory element has a first state corresponding to the first data. When the non-volatile static random access memory is at a reading mode, first readout data is generated according to the first state of the first non-volatile memory element is generated and provided to the first bit line.
[0008] The first switch and the second switch are turned on. At the reading mode, the first switch and the second switch are turned on. In another embodiment, between the writing mode and the reading mode, no supply voltage powers the non-volatile static random access memory circuit or the non-volatile static random access memory circuit is at a standby mode.
[0009] The non-volatile static random access memory circuit further comprises a writing control circuit. The writing control circuit is coupled to the latch circuit and receiving a writing selection signal to control the latch circuit. At the writing mode, the selection signal is at a first voltage level to control the latch circuit to change the first non-volatile memory element to be in the first state. At the reading mode, the writing selection signal is at a second voltage level to control the latch circuit to generate the first readout signal according to the first state.
[0010] In one embodiment, the latch circuit comprises a first first-type transistor, a first second-type transistor, a second second-type transistor, a second first-type transistor, a third second-type transistor, a fourth second-type transistor. The first first-type transistor has a control terminal coupled to a first node, an input terminal, and an output terminal coupled to a second node. A first second-type transistor has a control terminal coupled to a third node, an input terminal coupled to the second node, and an output terminal coupled to a ground. The second second-type transistor has a control terminal, an input terminal coupled to the first node, and an output terminal coupled to the second node. The second first-type transistor has a control terminal coupled to the first node, an input terminal, and an output terminal coupled to the third node. The third second-type transistor has a control terminal coupled to the second node, an input terminal coupled to the third node, and an output terminal coupled to the ground. The fourth second-type transistor has a control terminal, an input terminal coupled to a fourth node, and an output terminal coupled to the third node. The first non-volatile memory element is coupled between the second node and the fourth node. The second terminal of the first switch is coupled to the third node, and the second terminal of the second switch is coupled to the second node. At the writing mode, the second second-type transistor and the fourth second-type transistor are turned on. At the reading mode, the second second-type transistor and the fourth second-type transistor are turned off, and the input terminal of the first first-type transistor and the input terminal of the second first-type transistor receive a supply voltage of the non-volatile static random access memory circuit.
[0011] The non-volatile static random access memory circuit further comprises a third first-type transistor. The third first-type transistor has a control terminal, an input terminal coupled to a voltage source of the non-volatile static random access memory circuit, and an output terminal coupled to the input terminal of the first first-type transistor and the input terminal of the second first-type transistor. The control terminal of the second second-type transistor and the control terminal of the fourth second-type transistor receive the writing selection signal. At the writing mode, the third first-type transistor is turned off, and the writing selection signal is at a first voltage level to turn on the second second-type transistor and the fourth second-type transistor. At the reading mode, the third first-type transistor is turned on, and the writing selection signal is at a second voltage level to turn off the second second-type transistor and the fourth second-type transistor.
[0012] In an embodiment, the control terminal of the third first-type transistor receives the writing selection signal. At the writing mode, the writing selection signal is at the first voltage level to turn off the third first-type transistor. At the reading mode, the writing selection signal is at the second voltage level to turn on the third first-type transistor.
[0013] In another embodiment, the control terminal of the third first-type transistor receives a power gating signal. At the writing mode, the power gating signal is at a third voltage level to turn off the third first-type transistor. At the reading mode, the power gating signal is at a fourth voltage level to turn on the third first-type transistor. When the non-volatile static random access memory circuit is at a standby mode, the power gating signal is at a fourth voltage level to turn off the third first-type transistor.
[0014] In another embodiment, the latch circuit comprises a first first-type transistor, a first second-type transistor, a second second-type transistor, a second first-type transistor, a third second-type transistor, and a fourth second-type transistor. The first first-type transistor has a control terminal coupled to a first node, an input terminal, and an output coupled to a second node. The first second-type transistor has a control terminal coupled to the first node, an input terminal coupled to a third node, and an output terminal coupled to a ground. The second second-type transistor has a control terminal, an input terminal coupled to the second node, and an output terminal coupled to the first node. The second first-type transistor has a control terminal coupled to the first node, an input terminal, and an output terminal coupled to a fourth node. The third second-type transistor has a control terminal coupled to the third node, an input terminal coupled to the first node, and an output terminal coupled to the ground. The fourth second-type transistor has a control terminal, an input terminal coupled to the fourth node, and an output terminal coupled to the third node. The first non-volatile memory element is coupled between the first node and the fourth node. The second terminal of the first switch is coupled to the first node, and the second terminal of the second switch is coupled to the third node. At the writing mode, the second second-type transistor and the fourth second-type transistor are turned on. At the reading mode, the second second-type transistor and the fourth second-type transistor are turned off, and the input terminal of the first first-type transistor and the input terminal of the second first-type transistor receive a supply voltage of the non-volatile static random access memory circuit.
[0015] The non-volatile static random access memory circuit further comprises a third first-type transistor. The third first-type transistor has a control terminal, an input terminal coupled to a voltage source of the non-volatile static random access memory circuit, and an output terminal coupled to the input terminal of the first first-type transistor and the input terminal of the second first-type transistor. The control terminal of the second second-type transistor and the control terminal of the fourth second-type transistor receive the writing selection signal. At the writing mode, the third first-type transistor is turned off, and the writing selection signal is at a first voltage level (VDD) to turn on the second second-type and the fourth second-type transistor. At the reading mode, the third first-type transistor is turned on, and the writing selection signal is at a second voltage level to turn off the second second-type transistor and the fourth second-type transistor.
[0016] In an embodiment, the control terminal of the third first-type transistor receives the writing selection signal. At the writing mode, the writing selection signal is at the first voltage level to turn off the third first-type transistor. At the reading mode, the writing selection signal is at a second voltage level to turn on the third first-type transistor.
[0017] In another embodiment, the control terminal of the third first-type transistor receives a power gating signal. At the writing mode, the power gating signal is at a third voltage level to turn off the third first-type transistor. At the reading mode, the power gating signal is at a fourth voltage to turn on the third first-type transistor. The non-volatile static random access memory circuit is at a standby mode, the power gating signal is at a third voltage level to turn off the third first-type transistor.
[0018] In further an embodiment, the latch circuit further has a second non-volatile memory element. When the non-volatile static random access memory circuit is at the writing mode, second input data on the second bit line, is written into in the latch circuit, and the second non-volatile memory element has a second state corresponding to the second data. The non-volatile static random access memory is at the reading mode, second readout data is generated according to the second state of the second non-volatile memory element is generated and provided to the second bit line.
[0019] A detailed description is given in the following embodiments with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
[0021] FIG. 1 shows an exemplary embodiment of a non-volatile static random access memory circuit;
[0022] FIG. 2 shows another exemplary embodiment of a non-volatile static random access memory circuit;
[0023] FIG. 3A shows an embodiment of the operation of the non-volatile state random access memory device in FIG. 2 at a writing mode;
[0024] FIG. 3B shows an embodiment of the operation of the non-volatile state random access memory device in FIG. 2 at a reading mode;
[0025] FIG. 4A shows another embodiment of the operation of the non-volatile state random access memory device in FIG. 2 at the writing mode;
[0026] FIG. 4B shows another embodiment of the operation of the non-volatile state random access memory device in FIG. 2 at the reading mode;
[0027] FIG. 5 shows further another exemplary embodiment of a non-volatile static random access memory circuit;
[0028] FIG. 6A shows an embodiment of the operation of the non-volatile state random access memory device in FIG. 5 at a writing mode;
[0029] FIG. 6B shows an embodiment of the operation of the non-volatile state random access memory device in FIG. 5 at a reading mode;
[0030] FIG. 7A shows another embodiment of the operation of the non-volatile state random access memory device in FIG. 5 at the writing mode;
[0031] FIG. 7B shows another embodiment of the operation of the non-volatile state random access memory device in FIG. 5 at the reading mode;
[0032] FIG. 8 shows an exemplary embodiment of a non-volatile static random access memory circuit; and
[0033] FIG. 9 shows another exemplary embodiment of a non-volatile static random access memory circuit.
DETAILED DESCRIPTION OF THE INVENTION
[0034] The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.
[0035] Non-volatile static random access memory circuits are provided. In an exemplary embodiment of a non-volatile static random access memory circuit in FIG. 1 , a non-volatile static random access memory circuit 1 comprises a writing control circuit 10 , a latch circuit 11 , switches 12 and 13 . As shown in FIG. 1 , one terminal of the switch 12 is coupled to a bit line BL, and the other terminal thereof is coupled to the latch circuit 11 at a node N 10 . One terminal of the switch 13 is coupled to a bit line BLB, and the other terminal thereof is coupled to the latch circuit 11 at a node N 11 . Control terminals of the switches 12 and 13 are both coupled to a word line WL. The writing control circuit 10 is coupled to the latch circuit 11 for controlling operations when the non-volatile static random access memory circuit 1 operates at a writing mode or a reading mode. Through the controlling of the writing control circuit 10 , the data from the bit line BL and BLBs is continuously stored in the latch circuit 11 . Thus, before the non-volatile state random access memory device 1 enters the power-off state or the standby mode, the non-volatile state random access memory device 1 is not required to operate in a conventional storage mode. Moreover, after the power supply of the non-volatile state random access memory device 1 is on, the non-volatile state random access memory device 1 is not required to operate in a conventional recall mode. The detailed circuit structure and operation of the non-volatile state random access memory device 1 will be described in the following.
[0036] In an embodiment, referring to FIG. 2 , the writing control circuit 10 comprises P-type metal oxide semiconductor (PMOS) transistor 100 . A control terminal (gate) of the PMOS transistor 100 receives a writing selection signal WS, an input terminal (source) thereof is coupled to a voltage source VS of the non-volatile state random access memory device 1 , and an output terminal (drain) there is coupled to the latch circuit 11 at a node N 12 . The latch circuit 11 comprises PMOS transistors 200 and 201 , N-type metal oxide semiconductor (NMOS) transistors 202 - 205 , and non-volatile memory elements 206 and 207 . In the embodiment, the switches 12 and 13 are implemented by NMOS transistors 208 and 209 . A control terminal of the PMOS transistor 200 is coupled to a node N 20 , an input terminal thereof is coupled to the node N 12 , and an output terminal thereof is coupled to the node N 11 . A control terminal (gate) of the NMOS transistor 202 is coupled to the node N 10 , an input terminal (drain) thereof is coupled the node N 11 , and an output terminal thereof is coupled to a ground GND. A control terminal of the NMOS transistor 204 receives the writing selection signal WS, an input terminal thereof is coupled to the node N 20 , and an output terminal thereof is coupled to the node N 11 . The non-volatile memory element 206 is coupled between the node N 20 and the node N 10 .
[0037] A control terminal of the PMOS transistor 201 is coupled to a node N 21 , an input terminal thereof is coupled to the node N 12 , and an output terminal thereof is coupled to the node N 10 . A control terminal of the NMOS transistor 203 is coupled to the node N 11 , an input terminal thereof is coupled the node N 10 , and an output terminal thereof is coupled to the ground GND. A control terminal of the NMOS transistor 205 receives the writing selection signal WS, an input terminal thereof is coupled to the node N 21 , and an output terminal thereof is coupled to the node N 10 . The non-volatile memory element 207 is coupled between the node N 21 and the node N 11 .
[0038] As shown in FIG. 3A , when a supply voltage VDD powers the non-volatile state random access memory device 1 through the voltage source VS and the non-volatile state random access memory device 1 operates at the writing mode, the writing selection signal WS is at a high level of the supply voltage VDD (SW=VDD), and the word line WL has a high level. Assume that data of logic “0” is on the bit line BL (BL=0) while data of logic “1” is on the bit line BLB (BLB=1). Due to the writing selection signal WS with the high level, the PMOS transistor 100 is turned off (OFF) while the NMOS transistors 204 and 205 are turned on (ON). Due to the high level of the word line WL, the NMOS transistors 208 and 209 are turned on. At this time, in response to the data of logic “0” on the hit line BL, the node N 10 has a low level to turn off the NMOS transistor 202 . Due to the low level of the node N 10 and the turned-on state of the NMOS transistor 205 , the node N 21 has a low level. Moreover, in response to the data of logic “1” on the bit BLB, the node N 11 has a high level to turn on the NMOS transistor 203 . Due to the high level of the node N 11 and the turned-on state of the NMOS transistor 204 , the node N 20 has a high level.
[0039] As described above, the non-volatile memory element 206 is coupled between the node N 20 and the node N 10 , and the non-volatile memory element 207 is coupled between the node N 21 and the node N 11 . Since the node N 20 has the high level and the node N 10 has the low level, there is forward bias applied to the non-volatile memory element 206 , and the non-volatile memory element 206 has a low resistance state (LRS) to record the data of logic “0” no the bit line BL. On the contrary, since the node N 21 has the low level and the node N 11 has the high level. There is reverse bias applied to the non-volatile memory element 207 , and the non-volatile memory element 207 has a high resistance state (HRS) to record the data of logic “1” on the bit line BLB.
[0040] According to the embodiment, the data on the bit lines BL and BLB are recorded in the latch circuit 11 by the form of the resistance states of the non-volatile memory elements 206 and 207 . Thus, before the non-volatile state random access memory 1 enters the power-off state or the standby mode (that is the supply voltage VDD is not provided), a conventional storage mode is not required any more, thereby saving timing of the non-volatile state random access memory device 1 .
[0041] As shown in FIG. 3B , when the supply voltage VDD powers the non-volatile state random access memory device 1 through the voltage source VS and the non-volatile state random access memory device 1 operates at the reading mode, the writing selection signal WS is at a low level of 0V (WS=0), and the word line WL also has the high level. Due to the writing selection signal WS with the low level, the PMOS transistor 100 is turned on while the NMOS transistors 204 and 205 are turned off. The node N 12 has the high level of the supply voltage VDD through the turned-on PMOS transistor 100 . Due to the high level of the word line WL, the NMOS transistors 208 and 209 are turned on. At this time, since to the non-volatile memory element 206 has the low resistance state, the node N 20 is at a low level to turn on the PMOS transistor 200 . Through the turned-on PMOS transistor 200 , the node N 11 is at a high level (N 10 =“H”) in response to the high level of the node N 12 . Moreover, since to the non-volatile memory element 207 has the high resistance state, the node N 21 is at a high level to turn off the PMOS transistor 201 , The NMOS transistor 203 is turned on in response to the high level of the node N 11 . Thus, the node N 10 is at a low level (N 10 =“L”). The NMOS transistor 202 is turned off in response to the low el of the node N 10 .
[0042] As described above, the node N 11 is at the high level, and the node N 10 is at the low level. Through the turned-on NMOS transistor 208 , the bit line BL has a low level, that is the bit line BL reads the data of logic “0” from the latch circuit 11 . Through the turned-on NMOS transistor 209 , the bit line BLB has a high level, that is the bit line BLB reads the data of logic “1” from the latch circuit 11 . Further, since the PMOS transistor 201 and the NMOS transistor 202 are turned off, the bit line BL stably reads the data of logic “0” and the bit line BLB stably reads the data of logic “1” at the reading mode. Thus, after the power supply VDD of the non-volatile state random access memory device 1 is provided, the non-volatile state random access memory device 1 is not required to operate in a conventional recall mode, thereby saving timing.
[0043] FIGS. 4A and 4B show another embodiment of the operation of the non-volatile state random access memory device 1 at the writing mode and the reading mode respectively. In the embodiment, when the non-volatile state random access memory device 1 operates at the writing mode, data of logic “1” is on the bit line BL while data of logic “0” is on the bit line BLB, as shown in FIG. 4A . When the non-volatile state random access memory device 1 operates at the reading mode, the hit line BL stably reads the data of logic “1”, and the bit line BLB stably reads the data of logic “0”. The detailed operations of the elements of the non-volatile state random access memory device 1 in FIGS. 4A and 4B are similar to that in the embodiment of FIGS. 3A and 3B . Thus, the description related to the embodiment of FIGS. 4A and 4B is omitted here.
[0044] FIG. 5 shows another embodiment of the non-volatile state random access memory device 1 . Referring to FIGS. 2 and 5 , the different between the embodiments of FIGS. 2 and 5 is the structure of the latch circuit 11 . As shown in FIG. 5 , the latch circuit 11 comprises PMOS transistors 500 and 501 , NMOS transistors 502 - 505 , and non-volatile memory elements 506 and 507 . In the embodiment, the switches 12 and 13 are implemented by NMOS transistors 508 and 509 . A control terminal of the PMOS transistor 500 is coupled to the node N 10 , an input terminal thereof is coupled to the node N 12 , and an output terminal thereof is coupled to a node N 50 . A control terminal of the NMOS transistor 502 is coupled to the node N 10 , an input terminal thereof is coupled the node N 11 , and an output terminal thereof is coupled to the ground GND. A control terminal of the NMOS transistor 504 receives the writing selection signal WS, an input terminal thereof is to the node N 50 , and an output terminal thereof is coupled to the node N 10 . The non-volatile memory element 506 is coupled between the node N 50 and the node N 11 .
[0045] A control terminal of the PMOS transistor 501 is coupled to the node N 11 , an input terminal thereof is coupled to the node N 12 , and an output terminal thereof is coupled to a node N 51 . A control terminal of the NMOS transistor 503 is coupled to the node N 11 , an input terminal thereof is coupled the node N 10 , and an output terminal thereof is coupled to the ground GND. A control terminal of the NMOS transistor 505 receives the writing selection signal WS, an input terminal thereof is coupled to the node N 51 , and an output terminal thereof is coupled to the node N 11 . The non-volatile memory element 507 is coupled between the node N 51 and the node N 10 .
[0046] As shown in FIG. 6A , when a supply voltage VDD powers the non-volatile state random access memory device 1 through the voltage source VS and the non-volatile state random access memory device 1 operates at the writing mode, the writing selection signal WS is at a high level of the supply voltage VDD (SW=VDD), and the word line WL has a high level. Assume that data of logic “0” is on the bit line BL while data of logic “1” is on the bit line BLB. Due to the writing selection signal WS with the high level, the PMOS transistor 100 is turned off (OFF) while the NMOS transistors 504 and 505 are turned on (ON). Due to the high level of the word line WL, the NMOS transistors 508 and 509 are turned on. At this time, in response to the data of logic “0” on the bit line BL, the node N 10 has a low level to turn off the NMOS transistor 502 . Due to the low level of the node N 10 and the turned-on state of the NMOS transistor 504 , the node N 50 has a low level. Moreover, in response to the data of logic “1” on the bit line BLB, the node N 11 has a high level to turn on the NMOS transistor 503 . Due to the high level of the node N 11 and the turned-on state of the NMOS transistor 505 , the node N 51 has a high level.
[0047] As described above, the non-volatile memory element 506 is coupled between node N 50 and the node N 11 , and the non-volatile memory element 507 is coupled between the node N 51 and the node N 10 . Since the node N 50 has the low level and the node N 11 has the high level, there is reverse bias applied to the non-volatile memory element 506 , and the non-volatile memory element 506 is defined to has a low resistance state (LRS) to record the data of logic “0” on the bit line BL. On the contrary, since the node N 50 has the high level and the node N 10 has the low level. There is forward bias applied to the non-volatile memory element 507 , and the non-volatile memory element 507 has a high resistance state (HRS) to record the data of logic “1” on the bit line BLB.
[0048] According to the embodiment, the data on the bit lines BL and BLB are recorded in the latch circuit 11 by the form of the resistance states of the non-volatile memory elements 506 and 507 . Thus, before the non-volatile state random access memory device 1 enters the power-off state or the standby mode (that is the supply voltage VDD is not provided), a conventional storage mode is not required any more, thereby saving timing of the non-volatile state random access memory device 1 .
[0049] As shown in FIG. 6B , when the supply voltage VDD powers the non-volatile state random access memory device 1 through the voltage source VS and the non-volatile state random access memory device 1 operates at the reading mode, the writing selection signal WS is at a low level of 0V (WS=0), and the word line WL also has the high level. Due to the writing selection signal WS with the low level, the PMOS transistor 100 is turned on while the NMOS transistors 504 and 505 are turned off. The node N 12 has the high level of the supply voltage VDD through the turned-on PMOS transistor 100 . Due to the high level of the word line WL, the NMOS transistors 508 and 509 are turned on. At this time, since to the non-volatile memory element 507 has the high resistance state, the current passing through the non-volatile memory element 507 is less, and the node N 10 is at a low level (N 10 =“L”) to turn on the PMOS transistor 500 and turn off the NMOS 502 . Moreover, since to the non-volatile memory element 506 has the low resistance state, the current passing through the non-volatile memory element 506 is large, and the node N 11 is at a high level (N 11 =“H”) to turn off the PMOS transistor 501 and turn on the NMOS transistor 503 .
[0050] As described above, the node N 11 is at the high level, and the node N 10 is at the low level. Through the turned-on switch 12 , the bit line BL has a low level, that is the bit line BL reads the data of logic “0” from the latch circuit 11 . Through the turned-on switch 13 , the bit line BLB has a high level, that is the bit line BLB reads the data of logic “1” from the latch circuit 11 . Further, since the PMOS transistor 501 and the NMOS transistor 502 are turned off, the bit line BL stably reads the data of logic “0” and the bit line BLB stably reads the data of logic “1” at the reading mode.
[0051] FIGS. 7A and 7B show another embodiment of the operation of the non-volatile state random access memory device 1 at the writing mode and the reading mode respectively. In the embodiment, when the non-volatile state random access memory device 1 operates at the writing mode, data of logic “1” is on the bit line BL while data of logic “0” is on the hit line BLB, as shown in FIG. 7A . When the non-volatile state random access memory device 1 operates at the reading mode, the bit line BL stably reads the data of logic “1”, and the bit line BLB stably reads the data of logic “0”, as shown in FIG. 7B . The detailed operations of the elements of the non-volatile state random access memory device 1 in FIGS. 7A and 7B are similar to that in the embodiment of FIGS. 6A and 6B . Thus, the description related to the embodiment of FIGS. 7A and 7B is omitted here.
[0052] FIG. 8 shows another embodiment of the non-volatile state random access memory device 1 . The different between the embodiments of FIG. 2 and FIG. 8 is the structure of the writing control circuit 10 . In the writing control circuit 10 , the control terminal of the PMOS transistor receives a power gating signal PG instead of the writing signal WS. When the non-volatile state random access memory device 1 is at the standby mode and operates at the writing mode, the power gating signal PG has a high level to turn off the PMOS transistor 100 . When the non-volatile state random access memory device 1 operates at the reading mode, the power gating signal PG has a low level to turn on the PMOS transistor 100 . The operations of the other elements of the non-volatile state random access memory device 1 in the embodiment FIG. 8 are the same as that in the embodiment of FIGS. 2 , 3 A, 3 B, 4 A, and 4 B, omitting the related description here. In the embodiment, the writing selection signal WS has a low level at the standby mode.
[0053] FIG. 9 shows another embodiment of the non-volatile state random access memory device 1 . The different between the embodiments of FIG. 9 and FIG. 5 is the structure of the writing control circuit 10 . In the writing control circuit 10 , the control terminal of the PMOS transistor receives a power gating signal PG instead of the writing selection signal WS. When the non-volatile state random access memory device 1 is at the standby mode and operates at the writing mode, the power gating signal PG has a high level to turn off the PMOS transistor 100 . When the non-volatile state random access memory device 1 operates at the reading mode, the power gating signal PG has a low level to turn on the PMOS transistor 100 . The operations of the other elements of the non-volatile state random access memory device 1 in the embodiment FIG. 9 are the same as that in the embodiment of FIGS. 5 , 6 A, 6 B, 7 A, and 7 B, omitting the related description here. In the embodiment, the writing selection signal WS a low level at the standby mode.
[0054] While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should he accorded the broadest interpretation so as to encompass such modifications and similar arrangements. | A non-volatile static random access memory (nvSRAM) circuit is provided. The nvSRAM circuit includes first and second switches and a latch circuit. The first switch has a first terminal coupled to a first bit line. The second switch has a first terminal coupled to a second bit line. The latch circuit is coupled to second terminals of the first and second switches. The latch circuit has a first non-volatile memory element. When the nvSRAM circuit is at a writing mode, first input data on the first bit line is written into in the latch circuit, and the first non-volatile memory element has a first state corresponding to the first data. When the nvSRAM circuit is at a reading mode, first readout data is generated according to the first state of the first non-volatile memory element is generated and provided to the first bit line. | 6 |
BACKGROUND TO THE INVENTION
This invention relates to automobile door locking systems especially applicable to systems of the kind in which all doors can be locked simultaneously by a single locking operation.
STATEMENT OF PRIOR ART
In known systems each door has a latch operated from inside and outside by the door handles, and a locking mechanism which can be operated by the individual press down knobs or by a common switch operating all four locking mechanisms.
OBJECT OF THE INVENTION
The main object of the present invention is to provide a simultaneous locking system which is less complicated and occupies less space than presently used systems and which can easily and quickly be mounted on the doors and will provide additional safety to enable occupants to get out of a vehicle involved in an accident.
SUMMARY OF THE INVENTION
According to the present invention the system comprising mechanical means for connecting the door handle to the door latch, said mechanical means comprising separable parts, and electrically operated means for connecting said separable parts together whereby the latch can be released by operation of the door handle and for disconnecting said parts whereupon the latch can no longer be operated by actuation of the handle.
In the known central locking systems the central control actuates the door locking mechanisms whereas in the present invention the central control or external control (i.e. the electrically operated means) does not actuate the locking mechanisms but controls connections between the door handles and the door latches.
Therefore if for example a vehicle is involved in a road accident and the driver's lock control becomes inoperable it will still be possible to unlock the other doors and enable the occupants to escape.
The electrically operated means may be in the form (for each door) of a reversible electric motor coupled in a circuit with a capacitor and a resistor, the motor spindle having a pinion driving a rack which actuates a pin engageable in apertures in the separable parts, the four motors being controlled by a common switch.
A key operated cylinder switch resiliently biassed to a neutral position may also be provided on the driver's door and on the front passenger's door.
The normal press down buttons will be removed from the locking systems and may be replaced by an electromechanical indicator to indicate the state of the system, locked or unlocked when the separable parts are connected to or disconnected from each other.
In the case of partial or full power failure of the vehicle electrical system or malfunction of any electrical or mechanical part provisions may be made within the system to either electrically or mechanically override a locked condition such that entry can still be achieved.
BRIEF DESCRIPTION OF DRAWINGS
The invention will be further described by way of example with reference to the accompanying diagrammatic drawings wherein:
FIG. 1 is a sectional view of an electrically operated means for connecting and disconnecting separable parts to be inserted between a door handle and the door latch;
FIG. 2 is a sectional view thereof on the plane A--A on FIG. 3;
FIG. 3 is a plan view thereof;
FIG. 4 is a sectional view thereof on the plane B--B on FIG. 3;
FIG. 5 is a circuit diagram of the complete system;
FIG. 6 is a circuit diagram of a simpler form for the system;
FIG. 7 is a view of the connection between the door handle and the latch;
FIG. 8 is a sectional view of a door lock operating biassed off switch;
FIG. 9 is an end view thereof.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring first to FIGS. 1 to 4 two flat rods 12,13 are arranged slidably one upon the other in a guideway formed in a housing 14. The rod 12 is to be connected at 12A to the door handle and the rod 13 is to be connected at 13A to the door latch. A printed circuit board 16 is fixed in the housing 14 and a small reversible electric motor 17 is fixed on the board 16 together with a capacitor and resistor, these being connected in series with the motor. A resilient pad 15 is inserted between the housing 14 and board 16. The motor spindle carries a pinion 19 which normally gears with a toothed rack 20 which carries a block 21 that has a T-shaped slot 25. A pin 22 is engageable in holes in the rods 12,13 to hold them together but can be disengaged by actuation of the rack. The pin has a head 23 movable transversely of its axis along the slot 25. The pin is also engageable in a guide 26 which is urged to a position in alignment with the apertures in the rods 12,13 by a spring 27.
Thus when the pin 22 is withdrawn from the holes in the flat rods 12,13 the movements of the handle cannot undo the door latch. When the pin is inserted through the holes in the flat rods 12,13 the door handle is operatively connected with the latch and movement of the rods 12,13 is possible by the sliding of the pin 22 along the guide way 25.
In FIG. 5 the four motors are shown at 17A, 17B, 17C, 17D and the capacitor-resistor circuit at 18A, 18B, 18C, 18D. The motors and circuits are connected to a dashboard control switch 30 and to switches 35,36 on the door external key locks. The circuits 18A, 18B are in the driver's door and rear of driver's door respectively and include a fuse 32. The circuits 18C, 18D are in the front passenger's door and rear passenger's door respectively and include a separate fuse 33. The vehicle battery 34 is connected to the motors and switches. The driver's door lock switch 35 and the passenger's door lock switch 36 are connected across one side of the main switch 30. A door pillar switch 37 and an outlock prevention device 38 are connected between the battery and a power failure device 40, the latter including a transistor, diodes and capacitance arranged so that if the battery current fails the transistor-capacitor, upon closing of switch 37 (inside the car), will send an impulse to the motor 17A to unlock the driver's door.
FIG. 6 is similar to FIG. 5 but omits internal control switch 30 for central locking and therefore requires no outlock prevention and omits other parts such as 37,38,40. The switches 35,36 are connected direct to the battery 34.
All the motors are operated in one direction by an impulse derived from discharge of the capacitors and in the other direction by a direct impulse from the battery.
FIG. 7 shows one method of applying the invention to an existing door latch. The unlatch lever of the latch mechanism is shown at 42 and the door locking mechanism at 43. The rods 12,13 are connected respectively to the outer door handle lever 44 to the lever 42. A door keyswitch lever 62 on the driver's door is connected by a rod 62A to a pin 45 engaged in a slot 46 in a sleeve 47 which is attached to the lever 42. The rod 62A is normally connected to the locking mechanism but in the present construction the rod 62A is not so connected but is connected to the pin 45. The rod 62A enables the latch to be opened from outside the door in case of electrical power failure.
FIGS. 8 and 9 show a door keyhole housing 50 and usual barrel 51 containing the key tumblers. A housing 52 is mounted on the keyhole housing 50. The housing 52 is moulded from a synthetic plastics material so as to be flexible about a position 63 on its circumference so that it can be opened and placed around the housing 50 and can be locked in this position by a catch 58. The housing 52 carries a hollow extension 57 which contains a movable switch contact member 55 and two electrical contacts 60, 61. Springs (not shown) urge the movable member 55 circumferentially to a neutral "off" position. The movable member 55 has a projection 64 which extends through a slot in a steel plate 62 which is keyed to the barrel 51. A spring 67 urges a contact 56 axially towards the contacts 60,61.
The central locking system is made up of the following parts:
1. A dashboard mounted, switch operated, control box.
2. An electric motor driven mechanism situated in each vehicle door.
3. Key operated cylinder switches on driver's door and front passenger's door.
4. An electrical wiring loom connecting the control box with the individual door mechanism units and key cylinder switches.
The control box also may contain an electronic assembly which signals the driver's door in event of accident and a subsequent total power failure to an unlocked condition. Also there may be included a shock switch which gives signal to all door mechanisms, that are locked, to unlock, when power is still available in the event of an impact to, or by the vehicle, in excess of six and a quarter G.
The main features of the system of FIG. 5 may be summarized as follows:
1. To lock from inside all outer handles such that they are rendered inoperative. This is achieved via the dashboard mounted switch 30.
2. To lock from outside all outer handles such that are rendered inoperative. This is achieved via either of the key cylinder switches 35,36 mounted on the rear of each door cylinder.
3. Should any unit fail electrically or mechanically in a locked mode the driver's door can still be opened from outside via the key override lever 62A operating directly the latch mechanism.
4. Children's safety is unaffected as this can be incorporated in the door latch at both rear doors and is a separate mechanical operation. | An automobile door locking system comprises mechanical means for connecting the door handle to the door latch, said mechanical means comprising separable parts, and electrically operated means for connecting said separable parts together whereby the latch can be released by operation of the door handle and for disconnecting said parts whereupon the latch can no longer be operated by actuation of the handle. | 4 |
FIELD OF THE INVENTION
[0001] Embodiments of the invention relate to sensors, for example wearable sensors, for detecting acute stroke, and methods of using the sensors.
BACKGROUND OF THE INVENTION
[0002] Approximately 15.3 million strokes occur annually worldwide and about one third are fatal. Stroke is the second leading cause of death and accounts for significant disability, institutionalization, and health care cost. Strokes increase exponentially with advanced age, and, of course, the population ages. Strokes occur more frequently in African Americans, Native Americans and elderly women.
[0003] Risk factors for stroke include carotid disease, hypertension, atrial fibrillation, diabetes, smoking and sleep apnea. Men with moderate-to-severe sleep apnea had an almost threefold increased risk of ischemic stroke. Obstructive sleep apnea is among the most common chronic disorders in adults, occurring in 4% of middle-aged men and 2% of middle-aged women.
[0004] In the last decade, treatment of acute ischemic stroke caused by embolization from a carotid plaque or from atrial fibrillation has improved dramatically as a result of the use of local lytic agents and mechanical thrombectomy. These methods have allowed the recovery by patients that would previously have had a bad prognosis.
[0005] Time is often of the essence when attempting to reperfuse the brain tissue threatened by i schemia. In general, the opportunity to reverse a stroke exists within 3 hours of its occurrence. Today, patients can often be treated within three hours of the onset of the stroke and the success rate of this timely intervention is high. However, when the stroke occurs while the patient sleeps, it is likely that, by the time it is discovered, the patient cannot be treated until well after this 3 hour window of opportunity.
[0006] About one third of ischemic strokes occur during sleep. Embodiments of the present invention propose to solve this problem by allowing for detection of a stroke during sleep, thereby permitting immediate treatment.
[0007] There are at least 5 million patients in the United States with atrial fibrillation, which carries with it a 1 in 4 risk of cerebral emboli during the lifetime. Patients with severe carotid stenosis, patent foramen ovale, carotid dissections and shaggy aortas are also prone to develop ischemic cerebral emboli. Embodiments of the present invention can be particularly helpful for these high-risk patients.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 shows a dorsum side of a glove according to an embodiment described herein;
[0009] FIG. 2 shows the palm side of the glove of FIG. 1 ;
[0010] FIG. 3A shows the palm side of a glove according to another embodiment described herein;
[0011] FIG. 3B shows the dorsum side of the glove of FIG. 3A ;
[0012] FIG. 4 shows the inner portion of a bracelet according to embodiments described herein;
[0013] FIG. 5 shows the outer portion of a the bracelet of FIG. 4 ;
[0014] FIG. 6 shows a system arranged according to embodiments described herein; and
[0015] FIG. 7 shows a method of detecting a stroke according to embodiments described herein.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Unilateral arm paralysis is the most common manifestation of stroke. When a stroke occurs during sleep, there is cessation of the spontaneous and repeated electrical activity of muscles that occurs at frequent intervals. An object of embodiments of the present invention is to detect this cessation of electrical and muscle activity that takes place as soon as a stroke occurs and implement an automatic alarm system that will permit a curative intervention. This can be accomplished by detecting the absence of this periodic electrical and muscular activity transcutaneously by means of, for example, electromyography (EMG) electrodes. In one embodiment shown in FIGS. 1 and 2 , the cessation of electrical and muscle activity can be detected in the area of the hand that has the most musculature (the thenar eminence at the base of the thumb). In this embodiment, the electromyography electrodes (e.g., sensors 4 of FIGS. 1 and 2 ) will be attached to a glove 1 (e.g., the inner surface) to keep the electrodes 4 in position.
[0017] FIGS. 1 and 2 show an example of such a glove 1 according to an embodiment or the invention. FIG. 1 shows a view of the dorsum of a hand wearing the glove 1 , and FIG. 2 shows a view of the palm of the hand wearing the glove 1 . Both of these figures show the glove 1 on a left hand, but a mirror image of glove 1 can instead be worn on the right hand.
[0018] In the embodiment of FIGS. 1 and 2 , the glove 1 includes two electromyography sensors 4 . The sensors 4 ( FIG. 2 ) in the embodiment of FIGS. 1 and 2 are located on (either the inside or outside) or in the glove 1 so that they sit in the thenar eminence region of the hand, but the sensors could be placed in a different location on the glove 1 . Sensors 4 are two of the three EMG sensor electrodes. The third EMG sensor electrode can be placed in any appropriate place (e.g., dorsum). While the embodiment of FIGS. 1 and 2 shows two sensors, embodiments of the present invention contemplate any number of sensors. Each sensor 4 detects electrical and/or muscle activity in the hand.
[0019] The sensors 4 are connected to a transmitter 2 ( FIG. 1 ) by cable 3 . In a preferred embodiment shown in FIG. 1 , the transmitter 2 is located on (either the inside or outside) or in the glove 1 such that it is on the dorsum of the hand. The transmitter 2 receives signals from the sensors 4 via cable 3 and transmits those signals. The transmitter 2 can use any wireless protocol for transmission, for example Bluetooth®.
[0020] FIGS. 3 a and 3 b show an embodiment of a glove 1 ′ that is different from glove 1 in FIGS. 1 and 2 in that it also includes sensors 10 arranged on the wrist. Sensors 10 can be the same type of sensors as sensors 4 , and are used to sense electrical and muscular activity in the wrist. Sensors 10 are connected to transmitter 2 by cable 11 .
[0021] FIGS. 4 and 5 show an embodiment of a bracelet 12 containing only sensors 10 on the wrist. Sensors 10 are connected to transmitter 2 ′ by cable 11 ′.
[0022] FIG. 6 shows a portion of the system according to embodiments of the invention that receives the signal from the transmitters 2 , 2 ′ described in FIGS. 1-5 . The transmitter wirelessly transmits the signals received from the sensors (e.g, sensors 4 ) to a microcontroller 20 ( FIG. 6 ) at the bedside. The microcontroller 20 may process the signals (e.g., analog-to-digital conversion and rectification) and is configured to identify EMG signals. The microcontroller provides the processed EMG signals to a computing device 22 , for example a desktop or laptop computer, smartphone, tablet or any other type of computing device.
[0023] The microcontroller 20 can send the processed EMG signals to computing device 22 wirelessly using receiver/transmitter 21 and receiver/transmitter 23 . This wireless transmission can be any type of wireless transmission, including wife or Bluetooth®. Alternatively, the microcontroller 20 can send the processed signals to computing device 22 by cable 24 .
[0024] The computing device 22 is configured to analyze (e.g., by a software program) the EMG signals to determine the presence of a stroke. In the embodiment described above, if the computing device 22 determines that the EMG signals show an absence of electrical or muscular activity for an established period of time, a stroke is detected and the computing device 22 can automatically initiate an alarm system. For example, it can sound an audible alarm by, for example, placing a phone call to the patient's home. The microcontroller can also, or alternatively, alert emergency services.
[0025] Intervention within the three-hour window significantly increases the probability of recovery. Within this window, the earlier the patient is brought to the interventional suite, the lower the risk of intracerebral bleeding during rescue.
[0026] A typical night's sleep includes approximately four to five periods of what is called rapid eye movement (REM) when dreams occur. This REM typically comprises 20-25% of total sleep time in adults (about 90-120 minutes). During REM, brain activity is similar to the brain activity that occurs while awake, but there is paralysis of muscular activity that prevents movement during dreams.
[0027] An embodiment of the present invention provides a mechanism to distinguish the absence of signals representing electrical and muscle activity caused by REM from that caused by a stroke. In this embodiment, described below with respect to FIG. 7 , a glove and/or bracelet according to the above-described embodiments is worn on both hands and/or wrists to detect the absence or presence of electrical and/or muscular activity in the hands/wrists (step 100 , FIG. 7 ). The detected signals are sent from the gloves/bracelets on each hand/wrist to the microcontroller 20 ( FIG. 6 ) for processing. The microcontroller sends processed signals to the computing device 22 of FIG. 6 (step 101 , FIG. 7 ). The computing device 22 then determines if there is an absence of electrical and/or muscular activity on one hand/wrist, but not on the other (step 102 , FIG. 7 ). If the computing device 22 determines that sensors ( 4 and/or 10 ) in the gloves and/or bracelets detect absence of electrical and muscle activity on both hands and/or wrists, REM sleep, instead of a stroke, is detected and the sensors will not trigger the alarm (step 103 , FIG. 7 ). If electrical or muscular activity is detected in both hands/wrists, this also means that no stroke is detected (step 103 , FIG. 7 ). If absence of electrical and muscle activity is only detected on one hand, a stroke has been detected and the computing device 22 will trigger the alarm (step 104 , FIG. 7 ).
[0028] While the embodiment of FIGS. 1-5 shows wireless communication between the glove and a microcontroller, the glove can also send signals via a wire. | A system and method for detecting stroke in an individual, and in particular a sleeping individual. The individual has sensors on a least one hand or wrist for detecting electrical and/or muscular activity. The sensors may be included in or on a glove or bracelet worn by the individual. The absence of electrical and/or muscular activity is indicative of a stroke, and when such absence is detected, an alert is raised. Absence of detecting electrical and/or muscular activity can be detected in only one hand and/or wrist to avoid false alarms from REM sleep which results in the absence of electrical and/or muscular activity in both hands. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an improved process for obtaining durable press fabrics which exhibit no discoloration and which have higher strength than normally encountered in fabrics treated for durable press properties with a crosslinking agent and an aluminum salt catalyst. Specifically, this invention relates to use of the aluminum acetate salt-sodium chloride mixture produced from reaction of aluminum chloride and sodium acetate as catalyst in formulations containing formaldehyde or a formaldehyde-amide adduct crosslinking agent. Fabrics treated with said formulations have durable press properties and benefit by having no discoloration but higher strength than similarly treated fabrics in the singular presence of either aluminum chloride or sodium acetate as catalyst.
2. The Prior Art
Reeves et al., U.S. Pat. No. 3,526,474, employed metal acetates as polymerization catalysts in a novel finishing treatment for cotton. Although use of aluminum acetate was not demonstrated, Reeves et al., teach that this metal acetate, as well as magnesium acetate and zirconium acetate, is an effective polymerization catalyst. A requirement for polymerization catalysts to be suitable is that they be salts of a weak acid and a weak base. Such catalysts predominantly promote homopolymerization, or copolymerization when a mixture of aminoformaldehyde condensation products are present, to produce insoluble products within a cellulosic fiber rather than promote reaction of the agent with the cellulose. Evidently, the cellulose molecules are not crosslinked appreciably as they do not exhibit significant improvements in conditioned wrinkle recovery angles even though agents which are capable of crosslinking cellulose were cured in the fabrics at elevated temperatures.
Bacon, U.S. Pat. No. 2,992,138, used sodium acetate with zinc nitrate as a catalyst system for treatments with dimethylol ethyleneurea to reduce fabric yellowing, reduce strength loss, and reduce adverse effect on the shade of dyes as caused by zinc nitrate when it alone was used as catalyst.
Irvine and coworkers, American Dyestuff Reporter 48 (12), 37-42, 50 (1959), used modifying salts such as aluminum formate or magnesium chloride with aluminum chloride to avoid two serious disadvantages of aluminum chloride by itself. These disadvantages are: its permanent and high acidity results in excessive tendering of cellulosic fabrics; and its high acidity catalyzes resin condensation in treatment baths causing precipitation.
Hood and Ihde, Journal American Chemical Society, 72, 2094 (1950), by double decomposition of sodium acetate and aluminum chloride prepared basic aluminum acetate which was insoluble in water. These same workers, supra, also produced aluminum triacetate in the absence of water to prevent hydrolysis to Bohmite, AlO(OH).
The aluminum salts, Al(NO 3 ) 3 , Al 2 (SO 4 ) 3 , and AlCl 3 are very strong catalysts but each has inherent disadvantages which seriously limit their utility in textile finishing. In addition to those disadvantages cited above for AlCl 3 , Al(NO 3 ) 3 tenders fabric very badly and causes yellowing which is attributable to oxidation, while Al 2 (SO 4 ) 3 also causes tendering and yellowing at curing temperatures of 140° C. and higher.
In the prior art, no suitable means is disclosed for employing an aluminum acetate salt as catalyst in treatments with a cellulose crosslinking agent to produce a satisfactory level of durable press properties in finished fabrics. Homopolymerization or copolymerization of crosslinking agents result on use of aluminum acetate or magnesium acetate rather than effective crosslinking of the cellulose that is needed for the improved wrinkle recovery necessary for durable press performance. The aluminum salts, AlCl 3 , Al 2 (SO 4 ) 3 , and Al(NO 3 ) 3 , although strong catalysts for the crosslinking of cellulose with methylolamide agents, produce undesirable tendering of the fabric and discoloration.
SUMMARY OF THE INVENTION
The improved process of this invention may be described as one in which a new catalyst system is employed with a cross-linking agent to treat a cellulose-containing fabric to produce a durable press material. The catalyst system is prepared from aqueous aluminum chloride and aqueous sodium acetate to produce an aluminum acetate salt solution containing sodium and chloride ions.
It is an object of this invention to provide an improved process for obtaining durable press fabrics with an aluminum acetate salt catalyst system that has no adverse affect on fabric coloration and gives an acceptable level of strength in the finished fabrics. The importance for fabric treatments with no adverse coloration and no excessive strength loss is readily apparent to those skilled in the art of production of durable press materials.
It is a further object to provide a catalyst system that is operative at curing temperatures of about 130° C. to about 170° C. which are conventional in the textile finishing industry as well as at temperatures of about 200° C. wherein very rapid curing can be accomplished.
We have found that a solution resulting from addition of aqueous sodium acetate to aqueous aluminum chloride can provide an effective catalyst system for treatment of cellulose-containing fabrics with crosslinking agents to produce durable press materials. It is particularly surprising to find such a system is compatible and effective for fabric finishing. As taught by Hood and Ihde, one skilled in the art would predict formation of an insoluble aluminum acetate salt of the essential empirical structure: Al(OH)(CH 3 CO 2 ) 2 from the mixture. Use of the catalyst system produced by the mixing of solutions of aluminum chloride and sodium acetate is advantageous over the employment of either component by itself. Thus, the catalyst system of the present invention is effective in producing a durable press fabric with no discoloration and which exhibits greater strength than is normally present in fabric treated to the same level of wrinkle resistance with an aluminum salt catalyst.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Material that may be treated for improved durable press incorporating this catalyst system generally consists of woven fabric but also may be in the form of knits, nonwovens, yarns or fibers. Of significant importance to the material to be treated is that a minimum cellulosic composition of 50% is required. The cellulosic component may be selected from natural cellulosic matter such as cotton, linen, ramie, and the like, or from regenerated cellulosics. The remaining portion of material to be treated may consist of one or more man-made fibers blended with the cellulosic component.
Treating agents, more commonly referred to as crosslinking agents, useful in this improved process include N-methylol amides and aldehydes. Dimethylol dihydroxyethyleneurea, hereinafter referred to as DMDHEU, is the agent selected to demonstrate the improved process in most examples. The concentration of crosslinking agent employed may range from about 5% to about 25%, by weight of treatment solution, with the preferred range being about 7% to 15%.
The mixture of aluminum chloride and sodium acetate to produce the catalyst system comprising an aluminum acetate salt solution containing sodium and chloride ions may be varied in a weight ratio of aluminum chloride to sodium acetate from about 1.6:1 to about 0.5:1. The total weight percent concentration of the equivalent active aluminum acetate ingredient in the treatment bath may be varied from about 0.1% to about 3% with a preferred range of 0.15% to 2.5%. The catalyst of the present invention provides a finishing solution with a pH below 6.5, the pH at which aluminum salts are hydrolyzed to an insoluble form, but above the strongly acidic levels, about pH 1, that are produced by aluminum chloride, aluminum nitrate, and aluminum sulfate as catalysts.
Fabric treatment with the solution containing the crosslinking agent and catalyst system may be accomplished by any suitable means. As a matter of common practice, fabric is immersed in the treatment solution, often referred to as pad bath, to thoroughly saturate the fibers, and then passed through squeeze rolls to adjust the amount of treatment solution retained by the fabric. The amount of treatment solution retained is called the wet pickup which may range from about 50% to 120% based on the dry weight of the untreated fabric. For 100% cotton, the preferred range is 70-90%.
Fabric impregnated with the treatment solution is dried under conditions such that substantially no reaction takes place between the crosslinking agent and cellulose. The dried fabric is then heat treated to bring about the reaction whereby the cellulosic component is crosslinked. Conditions for this heat treatment step range from about 140° C. to about 200° C. for from about 15 seconds to about 3 minutes, time and temperature being inversely adjusted. Equipment used and material being treated will dictate the conditions required.
Once cured, the treated fabric is suitable for utilization in end products for which the fabric is designed. However, we have found it good practice to remove residual water soluble products from the cured fabric by washing.
The following examples illustrate but do not limit the scope of this invention.
EXAMPLE 1
A solution was prepared to contain a molar ratio of AlCl 3 to NaOOCCH 3 of 0.33 by dissolving 24.6 g. (300 millimoles) of NaOOCCH 3 in about 70 ml. of water in a 200 ml. volumetric flask, pipeting in 100 ml. (100 millimoles) of 1 M AlCl 3 and diluting the mixture to volume. This solution was labelled Solution A.
Another solution was prepared as was Solution A but substituting 100 millimoles of Al(NO 3 ) 3 for AlCl 3 . This solution was labelled Solution B.
Another solution was prepared as was Solution A but substituting 50 millimoles of Al 2 (SO 4 ) 3 for AlCl 3 . This solution was labelled Solution C.
Reaction of the AlCl 3 , Al(NO 3 ) 3 , or Al 2 (SO 4 ) 3 with NaOOCCH 3 in aqueous solution produces NaCl, NaNO 3 , or Na 2 SO 4 respectively with an aluminum acetate salt. The exact structure of the aluminum acetate salt present is not known but Solutions A, B, and C each contained a 0.2 molar concentration of the salt.
Solutions for the treatment of fabric were prepared such that each 100 g. of solution contained 9 g. of dimethylol dihydroxyethyleneurea and from 1 to 12.5 millimoles of aluminum acetate salt. The aluminum acetate salt was measured into each treatment solution by pipeting from Solutions A, B, or C respectively.
Cotton printcloth samples were passed into and through their respective treatment solutions, squeezed through pad rolls to about 80% wet pickup, by weight of fabric, then mounted at original dimensions on pin frames. Samples were dried for 7 minutes at 60° C. in a mechanical convection oven, cured for 3 minutes at 160° C., washed in an automatic home wash machine, tumble dried, and evaluated. Test results shown in this and following examples were obtained as follows:
Durable press (DP) ratings after tumble drying (TD) were determined by the procedure of AATCC Test Method 124-1969 (AATCC Technical Manual, Volume 46, pages 177-178, 1970);
Wrinkle recovery angles were determined by AATCC Test method 66-1968 (AATCC Technical Manual, Volume 46, pages 256-257, 1970);
Breaking strengths were determined on 1-inch strips by ASTM Method D1682-64; and, Nitrogen contents were determined by the Kjeldahl method.
TABLE 1______________________________________Catalyst Millimoles Al acetate DPpreparation salt per 100 g. treat- ratingmethod ment solution pH (TD) Coloration______________________________________Solution A 1 -- 2.5 5 -- 3.7 10 4.1 3.7 12.5 -- 4.0Solution B 1 -- 2.9 5 -- 3.4 10 3.9 4.2 Light yellow 12.5 -- 4.4 YellowSolution C 1 -- 1.9 5 -- 2.2 10 4.3 2.5 12.5 -- 2.9______________________________________
Treatment solutions containing Solution A, prepared from AlCl 3 , as catalyst were effective in producing durable press fabric when 5 or more millimoles of the aluminum acetate salt per 100 g. of treatment solution were used. A rating of 3 or higher is considered durable press by those skilled in the art. No fabric discoloration resulted when Solution A was used as catalyst. Solution B, prepared from Al(NO 3 ), was satisfactory as catalyst only at the 5 millimole level but not at higher concentrations as fabric discoloration occurred. Solution C, prepared from Al 2 (SO 4 ) 3 , was not satisfactory in development of a minimum acceptable DP rating of 3.
These results demonstrate that the aluminum acetate salt catalyst containing sodium and chloride ions prepared from solutions of AlCl 3 and NaOOCCH 3 is effective for development of durable press properties in fabric.
EXAMPLE 2
Treatment solutions were prepared such that each 100 g. contained 9 g. of dimethylol dihydroxyethyleneurea and from 1 to 12.5 millimoles of aluminum acetate salt catalyst obtained from Solution A of Example 1.
Cotton printcloth samples were treated with these solutions following the procedure of Example 1 and then evaluated. Results are shown in Table 2.
TABLE 2______________________________________Millimoles Alcatalyst salt Wrinkle recoveryper 100 g. treat- angles, W + F Brk. str.,ment solution Conditioned Wet w, lbs.______________________________________1 217 232 44.52.5 245 236 38.25 284 261 27.97.5 285 261 26.710 287 263 22.512.5 287 266 22.2Untreated -- -- 48.6______________________________________
The high conditioned and wet wrinkle recovery angles indicate the effectiveness of the aluminum acetate salt catalyst in promoting crosslinking of cellulosic material with a finishing agent. Strengths achieved with the 10 and 12.5 millimole concentrations of catalyst are typical of those of cotton printcloth finished for durable press. It was surprising, however, that treatments with 5 and 7.5 millimoles of catalyst yielded fabrics with even greater strength albeit with equally high levels of wrinkle recovery angles.
EXAMPLE 3
Catalyst systems were prepared as in the following theoretical equations by reaction of aqueous solutions to yield an active aluminum acetate ingredient in the presence of NaCl or NaCl plus NaOOCCH 3 .
______________________________________Mixture Active catalyst______________________________________(1) AlCl.sub.3 + NaOOCCH.sub.3 → Al(OOCCH.sub.3)Cl.sub.2 + NaCl(2) AlCl.sub.3 + 2NaOOCCH.sub.3 → Al(OOCCH.sub.3).sub.2 Cl + 2NaCl(3) AlCl.sub.3 + 3NaOOCCH.sub.3 → Al(OOCCH.sub.3).sub.3 + 3NaCl(4) AlCl.sub.3 + 4NaOOCCH.sub.3 → Al(OOCCH.sub.3).sub.3 + 3NaCl + NaOOCCH.sub.3______________________________________
Treatment solutions were prepared such that each 100 g. contained 9 g. dimethylol dihydroxyethyleneurea and 1 to 12.5 millimoles of equivalent yield of active catalyst based on equations (1) to (4) above.
Cotton printcloth samples were treated with solutions following the procedure of Example 1 and then evaluated. Results are shown in Table 3.
TABLE 3______________________________________Catalyst system Millimoles active DP rating(equation no.) catalyst (TD) Coloration______________________________________(1) 1 4.0 2 4.5 3 4.7(2) 1 2.7 2.5 3.5 5 4.0 7.5 4.4 10 4.3 Light yellow 12.5 4.3 Yellow(3) 1 2.5 2.5 3.2 5 3.7 7.5 4.0 10 4.3 12.5 4.0(4) 1 1.5 2.5 2.0 5 2.4 7.5 2.2 10 2.3 12.5 2.4______________________________________
These results demonstrate that aluminum acetate salt solutions prepared by reaction of AlCl 3 and NaOOCCH 3 at molar ratios of from 1:1 to 3:1 (NaOOCCH 3 :AlCl 3 ) are effective catalysts for obtaining durable press properties in fabric finished with an N-methylol crosslinking agent. It further demonstrates that concentrations of the active catalyst ingredient formed by the reaction of AlCl 3 and NaOOCCH 3 may range from 1 to 12.5 millimoles per 100 g. of treatment solution.
EXAMPLE 4
Catalyst systems were prepared following the procedures of Example 1, by mixing 3, 3.1, 3.25, 3.5, 3.75, and 4 moles of NaOOCCH 3 per mole of AlCl 3 to yield the equivalent active aluminum acetate salt with NaCl or with NaCl plus NaOOCCH 3 .
Treatment solutions were prepared such that each 100 g. contained 9 g. of dimethylol dihydroxyethyleneurea and 10 millimoles of the equivalent of the active catalyst as in equations (3) and (4) of Example 3.
Cotton printcloth samples were treated with the solutions following the procedure of Example 1 and then evaluated. Results are shown in Table 4.
TABLE 4______________________________________Molar ratio DP ratingNaOOCCH.sub.3 /AlCl.sub.3 (TD)______________________________________3 3.73.1 3.43.25 3.53.5 3.33.75 2.64 2.4______________________________________
Satisfactory DP(TD) ratings of 3 or higher can be achieved by treatments with aluminum acetate catalyst solutions prepared from aqueous sodium acetate and aqueous aluminum chloride in molar ratios of NaOOCCH 3 :AlCl 3 up to 3.5:1. This example demonstrates the upper limit of utility of the aluminum acetate salt catalyst solutions produced by reaction of AlCl 3 and NaOOCCH 3 in treatment of fabric to obtain acceptable durable press performance.
EXAMPLE 5
Samples of cotton printcloth were impregnated following the procedure of Example 1 with aqueous solutions, 100 g. of which contained 9 g. of dimethylol dihydroxyethyleneurea and as catalyst:
Sample 1--2.5 millimoles AlCl 3
Sample 2--5 millimoles AlCl 3
Sample 3--10 millimoles AlCl 3
Sample 4--2.5 millimoles Al(NO 3 ) 3
Sample 5--5 millimoles Al(NO 3 ) 3
Sample 6--10 millimoles Al(NO 3 ) 3
Sample 7--2.5 millimoles Al 2 (SO 4 ) 3
Sample 8--5 millimoles Al 2 (SO 4 ) 3
Sample 9--10 millimoles Al 2 (SO 4 ) 3 ; and
Sample 10--12.5 millimoles NaOOCCH 3 .
The wet, impregnated samples were dried, cured, washed and tumble dried following the procedure of Example 1 and then evaluated. Results are shown in Table 5.
TABLE 5______________________________________ DP rating Brk. str.,Sample (TD) w., lbs. Coloration______________________________________1 4.5 16.6 Light tan2 4.2 10.6 Tan3 4.6 10.3 Brown4 4.2 20.2 Very light yellow5 4.3 18.5 Yellow6 4.3 15.7 Yellow7 4.6 21.4 --8 4.5 13.0 --9 4.5 11.1 Light yellow10 1.5 -- --Blank 1.0 48.6 --______________________________________
These aluminum salts function very effectively as catalysts in promoting reaction between the finishing agent and cellulose to obtain high levels of durable press smoothness. Strength loss and discoloration, however, are serious disadvantages limiting their utility in practical finishing applications. Sodium acetate, on the other hand, is not an effective catalyst in this process.
EXAMPLE 6
An aqueous solution of catalyst was prepared, as was Solution A in Ex. 1, by adding aqueous AlCl 3 to aqueous NaOOCCH 3 .
Treatment solutions were prepared such that each 100 g. contained:
Sample 11--10 g. of dimethylol ethyleneurea (DMEU) and 7.5 millimoles of the aluminum acetate salt catalyst;
Sample 12--10 g. dimethylol methyl carbamate (DMMC) and 7.5 millimoles of the aluminum acetate salt catalyst;
Sample 13--9 g. of dimethylol dihydroxyethyleneurea (DMDHEU) and 7.5 millimoles of the aluminum acetate salt catalyst;
Sample 14--12.5 g. of trimethylol melamine (TMM) and 10 millimoles of the aluminum acetate salt catalyst;
Sample 15--15 g. of methylated urea-formaldehyde (MeUF) and 10 millimoles of the aluminum acetate salt catalyst;
Sample 16--9 g. of methylated methylol urea (MeUn) and 7.5 millimoles of the aluminum acetate salt catalyst; and,
Sample 17--7.5 g. of formaldehyde and 7.5 millimoles of the aluminum acetate salt catalyst.
Samples of cotton printcloth (2 each) were passed into and through the respective treatment solutions, squeezed through pad rolls to about 80% wet pickup by weight of fabric, then mounted on pin frames, and dried for 7 minutes at 60° C. One sample from each treatment was cured for 3 minutes at 160° C. and a second sample from each treatment was cured for 15 seconds at 200° C. (This latter cure is frequently referred to as a flash cure process.) After curing, samples were washed and tumble dried as in Example 1. Results of the above treatments are shown in Table 6.
TABLE 6______________________________________ DP rating (TD)Fabric when cured at: % N when cured at:treatment 160° C. 200° C. 160° C. 200° C.______________________________________Sample 11 4.0 3.5 1.26 1.26Sample 12 3.3 3.0 0.59 0.70Sample 13 3.6 3.4 0.85 0.83Sample 14 3.5 3.3 4.43 4.38Sample 15 3.7 3.3 2.06 1.99Sample 16 3.2 3.0 0.94 0.86Sample 17 3.3 3.3 -- --______________________________________
The broad utility of the catalyst is demonstrated by its effectiveness with a wide range of crosslinking agents (including formaldehyde and various types of formaldehyde-amide adducts) to produce fabrics with improved durable press properties. It is further demonstrated that the catalyst is not only effective at the conventional curing temperature of 160° C., but is also effective when a flash cure process is employed.
EXAMPLE 7
13.2 g. (75 millimoles) of Ca(OOCCH 3 ) 2 .H 2 O were dissolved in 65 ml. of water. Fifty ml. of 0.5 M (25 millimoles) Al 2 (SO 4 ) 3 were pipeted into the solution which resulted in formation of a precipitate. The mixture was filtered and washings of the precipitate were quantitatively collected with the filtrate in a 200 ml. volumetric flask. The solution was made to volume. Although the exact structure of the aluminum acetate salt formed in the reaction between Ca(OOCCH 3 ) 2 and Al 2 (SO 4 ) 3 is not known, the reaction is believed to have been according to the following equation:
3Ca(OOCCH.sub.3).sub.2 +Al.sub.2 (SO.sub.4).sub.3 →3CaSO.sub.4 (ppt)+2Al(OOCCH.sub.3).sub.3
The CaSO 4 precipitate (ppt) was removed by filtration and the resultant solution, when made to final volume, contained a 0.5 molar concentration of aluminum acetate salt.
Treatment solutions were prepared such that each 100 g. contained 9 g. of dimethylol dihydroxyethyleneurea and:
Sample 18--20 millimoles of this aluminum acetate salt (the pH of this solution was 4.4);
Sample 19--25 millimoles of this aluminum acetate salt, and;
Sample 20--12.5 millimoles of Ca(OOCCH 3 ) 2 . (The pH of this solution was 7.0.)
Cotton printcloth samples were treated with these treatment solutions following the procedure of Example 1. Durable press ratings for Samples 18, 19, and 20 were 2.4, 2.3, and 1.4 respectively. These poor ratings demonstrate that the aluminum acetate salt solution prepared from Ca(OOCCH 3 ) 2 is an unsatisfactory catalyst. This catalyst represents essentially an aluminum acetate solution free of other metal salts in that the calcium sulfate produced in the reaction was removed through precipitation and filtration. The poor rating with Ca(OOCCH 3 ) 2 in the treatment solution also demonstrates its ineffectiveness as a catalyst.
EXAMPLE 8
Commercial, reagent grade basic aluminum acetate [Al(OH)(OOCCH 3 ) 2 ], was weighed into a beaker, and water was added such that the resultant slurry contained 20 millimoles of the salt. To this slurry was added 40 millimoles of glacial acetic acid. The slurry did not become clear nor did heating affect dissolution indicating the conversion of the Al(OH)(OOCCH 3 ) 2 did not occur as would be expected according to the following equation:
Al(OH)(OOCCH.sub.3).sub.2 +CH.sub.3 COOH→Al(OOCCH.sub.3).sub.3 +H.sub.2 O
This example demonstrates that basic aluminum acetate, Al(OH)(OOCCH 3 ) 2 , is not suitable for catalysis in durable press finishing as the salt is not readily soluble in water nor is it readily converted to the more soluble aluminum acetate having the structure Al(OOCCH 3 ) 3 .
EXAMPLE 9
Treatment solutions were prepared such that each 100 g. contained 9 g. of dimethylol dihydroxyethyleneurea and:
Sample 21--7.5 millimoles of aluminum acetate [an aqueous commercial product supplied by American Cyanamid Company with 20±0.8% aluminum as Al(CH 3 COO) 3 ];
Sample 22--7.5 millimoles of aluminum acetate [the aqueous commercial product] and 22.5 millimoles of sodium chloride.
Cotton printcloth samples were treated as in Example 6, with the curing steps carried out at 200° C. for 15 seconds. Results of the above treatments are shown in Table 7.
TABLE 7______________________________________Fabric Treatment DP rating (TD) %N______________________________________Sample 21 2.9 0.92Sample 22 3.9 1.05______________________________________
The results demonstrate the significance of the presence of sodium and chloride ions in the aluminum acetate solution. The improved DP ratings and the higher level of nitrogen in Sample 22 demonstrate a greater reaction efficiency of the crosslinking agent with cotton when the aluminum acetate is agumented by the presence of sodium and chloride ions.
EXAMPLE 10
A treatment solution was prepared such that each 100 g. contained 9 g. of dimethylol dihydroxyethyleneurea and 10 millimoles of Mg(OOCCH 3 ) 2 (a commercial, reagent grade product).
A cotton printcloth was treated following the procedure of Example 1. The durable press rating of the finished sample was only 1.3, which is an unsatisfactory level of smooth-drying performance.
This demonstrates that Mg(OOCCH 3 ) 2 is unsuitable as a catalyst in the process of finishing cellulosic materials to produce durable press properties.
EXAMPLE 11
Treatment solutions were prepared such that each 100 g. contained 9 g. of dimethylol dihydroxyethyleneurea and 10 millimoles of the aluminum acetate salt from Solution A of Example 1 or 10 millimoles of AlCl 3 .
Samples from 50/50 cotton/polyester percale sheeting were treated with the above solutions following the procedure of Example 1 and evaluated. Results are given in Table 8.
Table 8______________________________________ Millimoles active DP ratingCatalyst system catalyst (TD) Coloration______________________________________Solution A 10 4.5 --AlCl.sub.3 10 4.3 Light brownUntreated -- 2.5 --______________________________________
This example demonstrates that the aluminum acetate solution prepared by reation of aqueous AlCl 3 and aqueous NaOOCCH 3 is an effective catalyst in the finishing of textile fabric comprising at least 50% of a cellulosic component to produce acceptable durable press performance. Furthermore, it demonstrates that AlCl 3 as catalyst in similar treatment produces discoloration in the finished fabric.
EXAMPLE 12
Catalyst systems were prepared to yield the equivalent active aluminum acetate salt by reaction of aqueous ingredients as in the following equations:
AlCl.sub.3 +3CH.sub.3 COOH→Al(OOCCH.sub.3).sub.3 +3HCl (5)
AlCl.sub.3 +3NH.sub.4 OOCCH.sub.3 →Al(OOCCH.sub.3).sub.3 +3NH.sub.4 Cl (6)
2AlCl.sub.3 +3Mg(OOCCH.sub.3).sub.2 →2Al(OOCCH.sub.3).sub.3 +3MgCl.sub.2 (7)
Treatment solutions were prepared such that each 100 g. contained 9 g. of dimethylol dihydroxyethyleneurea and 10 millimoles of the equivalent yield of aluminum acetate based on equations (5) to (7) above.
Cotton printcloth samples were treated with solutions following the procedure of Example 1.
Although each treated sample had an acceptable DP rating of 3.5, discoloration was observed as follows: brown when CH 3 COOH was used to prepare the aluminum acetate salt; light yellow when NH 4 OOCCH 3 was used; and very light yellow when Mg(OOCCH 3 ) 2 was used. These results show that to achieve a satisfactory DP rating with no discoloration only specific combinations of AlCl 3 and metal acetates are satisfactory for catalysis in the finishing process. | An aluminum acetate salt solution containing sodium and chloride ions is prepared by reaction of aqueous aluminum chloride and sodium acetate. It is suitable for use as a catalyst in the treatment of cellulosic-containing textiles with formaldehyde or a formaldehyde-amide adduct crosslinking agent to produce durable press properties in the finished material. There is no discoloration in the thus-treated fabric which also exhibits greater strength than is normally present in fabric treated to the same level of wrinkle resistance with an aluminum salt catalyst. | 3 |
BACKGROUND OF THE INVENTION
In conventional carpet washing machines the distributing unit for the detergent fluid and the scavenging agent are transferred in the direction of the rolls and with the nozzles of the distributing unit, the detergent fluid and/or the scavenging agent are sprayed on the surface of the carpet. In these machines, a separate source of power and a mechanism is needed for moving the distributing unit. This moving mechanism is positioned inside the frame of the machine and forms a part of the distributing unit. The mechanism, disposed inside the frame, is subject to very humid conditions and it is either expensive or undependable. The drying devices are positioned after the rolls and arranged to blow dry air on the surfaces of the carpets. The dryers used in conventional carpet washing machines are not efficient.
The purpose of the invention is to provide a machine for washing carpets, wherein the distributing unit of the detergent fluid and/or the scavenging agent is arranged to be moved by a simple and cost effective construction. Additionally, the aim with the invention is to provide a machine for washing carpets, wherein the drying device is simple in construction and efficient.
SUMMARY OF THE INVENTION
30 The goal of the invention is achieved by providing a machine for washing carpets, to which belongs a frame, inside the frame placed rolls, supported on which, the carpet is arranged to be transferred in the machine, inside the frame is positioned, in the length direction of the rolls, a movable distributing unit for detergent fluid and scavenging agent for spraying the detergent fluid and the scavenging agent on the surface of the carpet, and connected to the distributing unit are hoses for the detergent fluid and the scavenging agent, which are led from the inside of the frame out.
In the machine in accordance with the invention, the hoses of the detergent fluid and the scavenging agent are outside the machine at one end and connected with a transportation device fastened on the frame. The transportation device is arranged to transfer the hoses which in turn moves a distributing unit connected to the other end of the hoses. The transportation device is positioned outside the frame and does not exist in humid conditions. The rolls are placed inside the frame. The hoses are moved simultaneously (one for the transferring of the detergent fluid and the other the scavenging agent) to the distributing unit for the moving of the distributing unit. In the machine in accordance with the invention one advantage is that the hoses are always straight inside the frame, so that they are not bowed into sharp angles and break easily as they do in conventional machines.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be explained in more detail by referring to the attached drawings in which:
FIG. 1 presents an embodiment of the machine for washing carpets in accordance with the invention seen from the side in two different cutthroughs,
FIG. 2 presents the machine in accordance with FIG. 1 seen from the gable, and
FIG. 3 presents the machine in accordance with FIG. 1 seen from the gable with the gable cover opened.
DETAILED DESCRIPTION OF THE INVENTION
In the embodiment in accordance with FIGS. 1-3 a machine for washing carpets is shown. The machine has a frame 1. Disposed inside the frame are rolls 2, a distributing unit 4, hoses 5, 6, which have been led from the inside of the frame to the outside. Outside the frame is placed a transportation device 7. In this embodiment, the machine has five rolls 2, four rolls have been arranged by pairs with the fifth placed in the middle of the roll pairs at a distance therefrom. In accordance with the FIG. 3, the carpet 3 is fed into the machine from an opening on the left side of the frame 1, transferred inside the machine supported by the rolls 2 and fed-out through the opening 10 on the right side of the machine. The distributing unit 4 for the detergent fluid and the scavenging agent is placed between the rolls 2 and it is moved inside the frame 1 supported by the rails 11 in the lengthwise direction of the rolls. On one end of the distributing unit, the hose 5 is connected, transporting the detergent fluid. The other end the hose 6 transports the scavenging agent. Nozzles 12 of the distributing unit are directed in two directions. The nozzles directed in one direction are connected with the detergent fluid hose and in the other direction, the nozzles are connected with the scavenging agent hose. The carpet lies bowed on the rolls, with the filaments of the part of the carpet on top of the rolls, being open. The detergent fluid and the scavenging agent nozzles are aimed at the bowed spots so that the detergent fluid and the scavenging agent can have an efficient influence on the carpet. The detergent fluid hose 5 and the scavenging agent hose 6 are led form the inside of the frame out, supported on the supporting elements 9 fixed on the sides of the frame 1, which, in this embodiment are wheels. The supporting elements 9 are fastened from their one end on the transportation device 7, which is fixed movably on the frame 1. The hoses form an endless looping with the supporting elements 9, because their one end is fastened on the distributing unit 4 and the other end is connected to the transportation device 7. The lengths of the detergent fluid hose and the scavenging agent hose are mainly equal. The machine includes a supporting bar 8 disposed on top of the frame, extending in the length direction of the rolls. The transportation device 7 is movably fastened on the supporting bar. The transportation device 7 is moved in about the supporting bar 8 in a known manner, for instance with the help of a cylinder or the like. The detergent fluid hose 5 and scavenging agent hose 6 are led from the outside of the machine, connected with the transportation device 7 at one end and connected to the distributing unit 4 at the other end.
When operating the machine, the transportation device 7 is transferred with the help of a power source supported on the supporting bar 8. The detergent fluid hose 5 and the scavenging agent hose 6 are transferred along with the transportation device 7. Also, the hoses 5, 6 with their other end connected to the distributing unit, move inside the frame simultaneously.
Belts 13 are positioned between the rolls 2 at a suitable distance from each other. The carpet is supported on the belts 13 while the carpet is transferred inside the machine. Between the middle roll and the scavenging rolls have been placed guiding devices 14, which are arranged to transfer the positions of the belts in regard of the carpet. Consequently, the spot situated underneath the belt will be scavenged in an efficient way. Between the washing and the scavenging rolls second guiding devices 15 are positioned, which are arranged to transfer the belts back again. In an embodiment of the transportation device, a net is used.
In a second embodiment of the invention, a washing and scavenging device is disposed inside the middle of the frame, above the roll, the structure and function of which correspond to the unit described above. The carpet can be washed efficiently on both the sides in this embodiment.
A machine in accordance with the invention is particularly aimed for washing of non-woven mats. In a preferred embodiment of the invention, the machine includes a drying device disposed outside the frame. The drying device is positioned, in the length direction of the rolls and includes movable drying air blower or a corresponding device. With the drying fan air is blown on the surface of the carpet. The drying device includes a roll or rolls, on which the carpet is laid in a bowed position, to facilitate efficient drying. The air blower is connected with the transportation device described above by means of drying air hoses and is moved in the same manner as the distributing unit, simultaneously in the transverse direction of the carpet.
In another embodiment of the invention, the drying device includes rolls (not presented in the figures), between which the carpet is directed after the scavenging rolls. Between these rolls the carpet is pressed as dry as possible. The drying is continued afterwards by means of a drying air blower or with a corresponding drying device. The drying rolls are pressed against each other along their entire length with pneumatically or hydraulically controlled pressing units, which are positioned on the surfaces of the rolls. The pressing unit is preferably a hose like element stretching in the length direction of the rolls, which is pressed evenly against the rolls. As an alternative, individual pressing units may be used or to it may include several disposed at a distance from each other, positioned on the surface of the roll. These rolls are not pressed against each other from the ends only, but from the middle part as well. The carpet coming from between the rolls is mainly equally drying its every spot with drying taking place evenly.
The invention is not limited to the embodiments presented here, but it can vary within the spirit of the claims. | A machine for washing carpets having a frame, a plurality of elongated rolls located in the frame for transferring the carpet through the machine, and a distributing unit mvoable along the length of the rolls for spraying cleaning solution on the carpet. The machine also includes hoses connected at one end to the distributing unit, and at the other end, to a transportation device. The transportation device is movable, which moves the hoses, which in turn moves the distributing unit along the length of the rolls. | 3 |
BACKGROUND OF THE INVENTION
The present invention relates to knitted tulles and methods of knitting tulles.
Tulle is a type of fine netting which has applications in embroidery, lingerie, bridal wear and haute couture as well as in technical areas where the durability and flexibility of netting are of particular importance. Such technical applications include military (e.g. radar reflective netting and parachute netting) and medical applications and as light diffusion fabrics in film and theatre applications.
Bobbinet tulle is a particular type of tulle which was first produced in the early 19 th Century following the invention of the bobbinet machine in 1806 by John Heathcoat. The structure of bobbinet tulle provides advantageous properties of uniformity, strength and flexibility. One particularly advantageous property of bobbinet tulle in relation to embroidery is that it is flexible at the scale of the holes in the net structure which reduces the likelihood of yarn breakage when an embroidery needle (especially in machine embroidery) passes through the hole.
Unfortunately, the production of bobbinet tulle, which still uses the mechanisms devised by John Heathcoat, is slow. Bobbinet tulle is thus expensive and so is not, in practice, used in applications where its properties would otherwise make it suitable.
There have been attempts to devise faster production methods for nets or openwork fabrics using knitting machines, in particular, warp knitting machines. GB-A-1,275,448 relates to a method of producing patterned net fabrics on a Raschel warp knitting machine. GB-A-2,325,674 relates to an openwork knitted fabric that has a high capacity for absorption of size and so can be made harder and stiffer than previous fabrics.
There have also been attempts to produce knitted tulles or tulle-like materials. GB-A-1,230,232 relates to tulle having hexagonal openings produced on a Raschel knitting machine.
Unfortunately, the tulle described in GB-A-1,230,232 has a pattern which is very sensitive to differences in tension in the inlay threads. Unless the tension in each inlay thread is the same, the tulle is extremely distorted. It is, in practise, very difficult to control the tension of the inlay threads to the required degree because even a relatively narrow warp knitting machine may have over 5,000 separate inlay threads.
SUMMARY OF THE INVENTION
The present invention aims to provide a knitted tulle having the advantages of bobbinet tulle but avoiding or alleviating the problems of the prior art.
The present invention accordingly provides, in a first aspect, a knitted tulle comprising a plurality of wales each wale preferably having a pillar stitch (i.e. overlap) and at least two pairs of weft threads, wherein each pair of weft threads interconnects and ties-in (i.e. underlaps) at least four wales.
Preferably, each pair of weft threads interconnects and ties-in four wales only. Each pair of weft threads may interconnect and tie-in more wales than this (for example 5, 6, or more), however, the more wales which are interconnected and tied-in, the more complicated the tulle and, generally, the greater the repeat length.
Preferably, the tulle is flat (i.e. not a tube).
Preferably, the pattern is such that four or more inlay threads inlay on each wale. This is advantageous because it adds robustness, stability and strength to the pattern.
The interconnection and tying-in of at least four wales is greatly advantageous in that any differences in tension between the individual weft threads are spread more evenly across the tulle as a whole providing regularity, evenness, strength and flexibility. In particular, the holes of the tulle fabric are more regular in size which results in a stronger and more robust product and is visually more appealing in the marketplace.
Preferably, each weft thread of each pair interconnects and ties-in (i.e. crosses over between) at least three (preferably adjacent) wales. Each weft thread may interconnect and tie-in more wales than three, but this significantly increases the complexity of the pattern and the repeat length.
The interconnection and tying-in of at least three wales by each weft thread is advantageous because it also results in differences in tension being spread more evenly across the tulle as a whole, contributing to the regularity, evenness, flexibility and strength of the tulle.
Preferably, each weft thread of each pair follows a pattern which is the mirror image of the other weft thread in the pair; the mirror plane being substantially parallel to the wales.
Preferably, each pair of weft threads follows the same basic pattern, with respective pairs following patterns that may be shifted (i.e. offset or out-of phase) by a predetermined number of courses with respect to the pattern of another (or patterns of other) pair(s). In addition, or alternatively, respective pairs may follow patterns that are inverted with respect to the pattern of another (or patterns of other) pair(s). Such an inversion may be across a plane substantially perpendicular to the wales (and possibly parallel to the courses).
A first pair of weft threads which shares a wale with a second pair of weft threads, may follow a pattern which is out-of-phase with the pattern of the second pair by a predetermined number of courses.
Generally, the repeat length of the pattern will be a multiple of the predetermined number of courses to ensure that the pattern is regular. Preferably, the predetermined number of courses is a quarter of the repeat length, although it may be a half, third, fifth or sixth.
The predetermined number of courses may be 1 to 24, preferably 4 to 18, or 4 to 12, most preferably 6. The out-of-phase shift is advantageous because it improves the appearance and evenness of the tulle.
The first pair of weft threads may additionally, or alternatively, describe a pattern which is an inversion of the pattern of the second pair. Thus, preferably a first pair of weft threads which shares a wale with a second pair of weft threads follows a pattern which is an inversion of the pattern of the second pair.
The relationship of the pattern of each weft thread in the pair and of (e.g. immediately) neighbouring pairs of weft threads result in a regular overall pattern in the tulle leading to advantages in strength and robustness of the product.
Preferably, the tulle has substantially hexagonal holes. It is also advantageous if the tulle is substantially regular in either weft direction, the warp direction, or preferably both.
Usually, the pattern described by each pair of weft threads has a repeat of 12 to 60 courses. More preferably, the pattern followed by each pair of weft threads has a repeat of 12 to 48, 12 to 36, most preferably, of 20 to 30 courses. The preferred embodiment has a repeat of 24 courses.
Preferably, the pattern of each pair of weft threads includes at least two cross overs (i.e. two points at which the threads of the pair cross over each other).
In the most preferred embodiment of the invention, each weft thread of the first pair crosses to the corresponding wale of the other weft thread over three courses to form a first cross between the two wales, each weft thread of the pair then making six inlays in opposite directions on their respective wales, each weft thread of the pair then crossing over to a wale distal to the wale of the other weft thread in three courses over two wales, each weft thread then making three inlays in opposite directions in three courses, each weft thread then crossing over to its previously occupied wale in three inlays over three courses, crossing over to the corresponding wale of the other weft thread in three inlays over three courses to form a second cross between the two wales and each weft thread then making three inlays over three courses in opposite directions.
Preferably, the second pair of weft threads follows a pattern which is the inverse of, and/or is out-of-phase by a predetermined number of courses with, the pattern followed the first pair.
The tulle according to the first aspect of the invention may comprise synthetic or natural yarn. Examples of yarn which may be used to produce the tulle may be selected from polyester, polyamide (e.g. 6 or 66), polyaramid (meta and/or para), cotton, wool, hemp, silk and/or a mixture of one or more of these yarns. Generally any yarn which may be used in the textile industry would be suitable, depending on the intended application, however, preferred yarns are silk, cotton, polyester or nylon (i.e. polyamide).
The yarn count is preferably from 17 decitex to 280 decitex but may be greater or lesser than this for certain, specific applications.
Generally, the hole count of the tulle according to the first aspect of the invention will be between 14 and 128 holes per inch (5 to 51 holes per cm).
One of the great advantages of the tulle according to the present invention is that it is flexible, especially at the scale of the holes in the fabric. This is particularly advantageous for tulle used in embroidery because the flexibility of the threads defining each hole means that there is significantly less chance of yarn breakage when an embroidery needle passes through the hole. The applicant has surprisingly discovered that, as in bobbinet tulle, the threads defining the hole are flexible enough to move aside to allow the passage of an embroidery needle even if it is not precisely directed through the centre of the hole.
The tulle according to the present invention has a further advantage in that the fabric as a whole is flexible and resilient.
As discussed above, the knitted tulle according to the first aspect of the invention is produced by a knitting process. The present invention, accordingly provides, in a second aspect, a method of knitting a tulle, the method comprising forming a plurality of wales, and interconnecting at least some wales with at least two pairs of weft threads, wherein the method is such that each pair of weft threads interconnects and ties-in at least four wales.
The preferred method of knitting is warp knitting. Warp knitting is preferably performed using a Raschel knitting machine.
In the preferred embodiment of the invention, the Raschel knitting machine has 5 or more guide bars (e.g. 5, 6, 7, 8, or more guide bars). One guide bar is required in order to form the stitches, the remaining 4 guide bars are used to generate the inlays of two pairs of weft threads which define the tulle holes.
Preferably the machine gauge of the machine used to knit the tulle is 20 needles per inch to 50 needles per inch (8 needles per cm to 20 needles per cm).
Preferably, the machine is a single needle bed machine to produce a flat (i.e. not a tube) fabric.
Other preferred and optional features of the method of the second aspect of the invention are generally as described in relation to the first aspect, with appropriate modification.
Tulle produced according to the invention finds uses in technical fabrics, embroidery, automotive applications, theatrical, film, military and apparel dress and headwear applications. One particularly important use of the tulle according to the present invention is embroidery both because of the advantages it shares with traditional bobbinet tulle but also because it can be made at a much faster rate and is, therefore, more cost effective.
Thus, in a third aspect of the present invention, the present invention provides an embroidered fabric comprising a tulle according to the first aspect of the invention. The present invention also provides a product comprising a tulle as described in relation to the first aspect of the invention.
In a fourth aspect of the present invention, there is provided a knitted tulle comprising a plurality of wales and a plurality of weft threads, wherein each weft threads interconnects and ties-in at least three wales.
BRIEF DESCRIPTION OF THE DRAWINGS
By way of example, an embodiment of the present invention will now be described with reference to the accompanying drawings, in which:
FIG. 1 illustrates a prior art pattern of a knitted cross-tulle as disclosed in GB-A-1230232.
FIG. 2 illustrates the pattern of a single weft thread in a tulle according to the present invention.
FIG. 3 illustrates the pattern of a pair of weft threads in a tulle according to the present invention.
FIG. 4 illustrates schematically, the pattern of a plurality of first pairs of weft threads over a plurality of wales.
FIG. 5 illustrates, schematically, the pattern of a plurality of second pairs of threads over a plurality of wales.
FIG. 6 illustrates, schematically, the pattern of the tulle of the present invention consisting of an overlay of the patterns illustrated in FIGS. 4 and 5 .
DETAILED DESCRIPTION OF THE INVENTION
A prior art pattern, illustrated, in FIG. 1 , is of a knitted cross-tulle consisting of single-needle wales 1 , 2 and 3 which are formed singly and are interlaced only by weft threads. Weft threads 4 , 5 , 6 and 7 are shown. The weft threads 4 and 5 form one pair and the weft threads 6 and 7 another pair.
The weft threads 4 and 5 , and 6 and 7 , make three laps into the wales in three courses. Two of these adjoining runs of three laps are indicated by numerals 8 and 9 . The weft threads then form a cross 10 and 11 , respectively, between the wales 1 and 2 , and between the wales 2 and 3 , over three courses (described as two courses in the document but more properly considered as three). The weft threads 4 and 5 then effect, in the wales 1 and 2 , and the weft threads 6 and 7 effect, in the wales 2 and 3 , the three laps 8 and 9 respectively, whereupon they return to their initial wales by crossing over three courses.
The fabric produced using the pattern of FIG. 1 is very sensitive to even small differences in tension between the threads. Such differences result in severely distorted fabric. This may be a reason why the fabric of GB-A-1230232 does not appear to have been commercialised.
The pattern of a single weft thread in a tulle according to the present invention is illustrated in FIG. 2 . The pattern has a 24 course repeat, over the course of which the pillar stitches on the wales 14 ( 1 ), 14 ( 2 ), 14 ( 3 ) are interconnected and tied-in. The weft thread 15 makes a complete three inlay cross-over 21 between the first 14 ( 1 ) and second wale 14 ( 2 ) and then makes six inlays 22 over six courses. Over the next three courses, the weft thread 15 crosses over in three inlays 23 to the third wale 14 ( 3 ). The weft thread 15 makes four inlays 24 on the same wale 14 ( 3 ) before crossing over with two inlays 25 back to the second wale 14 ( 2 ). An inlay 26 is made on wale 14 ( 2 ) then the weft thread 15 crosses-over with two inlays 27 to the first wale 14 ( 1 ). The pattern is completed with four inlays 28 on the first wale 14 ( 1 ).
The pattern of a pair of weft threads 17 , 19 is illustrated in FIG. 3 . The first weft thread 17 of the pair follows a pattern that is the inversion of the pattern as described in relation to FIG. 2 ; the plane of inversion being parallel to the courses and perpendicular to the wales. The second weft thread 19 of the pair follows a pattern that is a mirror image of the pattern followed by the first weft thread 17 ; the mirror plane being substantially parallel to the wales. Thus, the second weft thread 19 starts the pattern at the third wale 18 ( 3 ) and inlays are lapped in the opposite direction to those of the first weft thread 17 . The first 17 and second 19 weft threads cross at courses four to six, 30 , and again at courses 22 and 24 , 32 . The pair of weft threads 17 , 19 interconnects and ties-in four wales 18 ( 1 ), 18 ( 2 ), 18 ( 3 ) and a fourth wale adjacent to 18 ( 3 ) (the fourth wale not being shown in FIG. 3 ).
The pattern of a plurality of the first pairs of weft threads 15 , 16 is illustrated in FIG. 4 . Each pair of weft threads 15 , 16 consists of a first weft thread 15 following the pattern described above and illustrated in FIG. 2 , and a second weft thread 16 following the mirror image of that pattern. FIG. 4 illustrates the pattern formed by a plurality of pairs of weft threads 15 , 16 , and represents the pattern of half of the weft threads in an embodiment of a tulle according to the present invention. The pattern as illustrated over the line 36 repeats above the repeat line 34 .
The pattern of a plurality of the second pairs of weft threads 17 , 19 is illustrated in FIG. 5 . Each pair of weft threads 17 , 19 follows the pattern described above and illustrated in FIG. 3 . The pattern of the second pairs of weft threads 17 , 19 is an inversion of the first pair of weft threads 15 , 16 illustrated in FIG. 4 and represents the pattern of the other half of the weft threads in an embodiment of a tulle according to the present invention. The pattern as illustrated over the wales 38 repeats above the repeat line 34 .
The pattern of both the first and second pairs of weft threads 15 , 16 and 17 , 19 in a tulle according to an embodiment of the invention is illustrated in FIG. 6 . The complete pattern as illustrated over the line 40 repeats above the repeat line 34 . The complete pattern exhibits an array of substantially hexagonal holes 46 , 52 , 54 defined by the weft threads 15 , 16 and 17 , 19 between crosses in the weft threads 15 and 16 at 42 and 48 and crosses between the weft threads 17 and 19 at 44 and 50 .
The tulle as illustrated in FIGS. 2 to 6 may be produced using a Raschel warp knitting machine having 5 or more guide bars. Guide bar 1 is used to define the wales with a pillar stitch with guide bars 2 to 5 used to define inlay weft threads, 17 , 15 , 16 , 19 respectively as illustrated in FIGS. 2 to 6 . Table 1, below, describes the guide bar movements for the weft threads for the interlacing of the otherwise unconnected wales.
As discussed above, the guide bar movements for guide bars 2 and 3 (corresponding to weft threads 17 and 15 ) and guide bars 4 and 5 (corresponding to weft threads 16 and 19 ) are an inversion of each other. Also, the movements of guide bars 3 and 4 (weft threads 15 and 16 ) and guide bars 2 and 5 (weft threads 17 and 19 ) follow patterns that are mirror images of each other.
A tulle according to the invention is much more forgiving of differences in tension between threads, the pattern appears to spread out differences in tension, resulting in a much more regular and strong tulle. The knitted tulle's flexibility and robustness provide a tulle which is directly comparable in its properties to bobbinet tulle.
TABLE 1
Inlays
Bar 2
Bar 3
Bar 4
Bar 5
1/
2
0
6
4
2/
0
2
4
6
3/
2
4
2
4
4/
0
2
4
6
5/
2
4
2
4
6/
4
2
4
2
7/
2
4
2
4
8/
4
2
4
2
9/
6
4
2
0
10/
4
2
4
2
11/
6
4
2
0
12/
4
6
0
2
13/
6
4
2
0
14/
4
6
0
2
15/
2
4
2
4
16/
4
6
0
2
17/
2
4
2
4
18/
4
2
4
2
19/
2
4
2
4
20/
4
2
4
2
21/
2
0
6
4
22/
4
2
4
2
23/
2
0
6
4
24/
0
2
4
6 | A knitted tulle is disclosed, the tulle comprising a plurality of wales, each with a pillar stitch and at least two pairs of weft threads, each pair of weft threads interconnecting and tying-in at least four wales. Also disclosed is a method of knitting the tulle, preferably using a Raschel machine and an embroidered fabric comprising the tulle. The tulle according to the invention is robust and even and has properties similar to bobbinet tulle. | 3 |
BACKGROUND OF THE PRESENT INVENTION
[0001] 1. Field of Invention
[0002] The present invention relates to an electrical appliance, and more particularly to a process of controlling an operation of an electric kettle.
[0003] 2. Description of Related Arts
[0004] Conventional electric kettle is useful in our daily life, and brings us lots of conveniences. The conventional electric kettle generally incorporates with a simple controlling process for controlling the boiling point of the water, for cutting off the power when the water in the electric kettle is evaporated, and for keeping the water at a predetermined temperature. However, such controlling process has a major drawback that the process fails to accurately control the temperature of the water.
SUMMARY OF THE PRESENT INVENTION
[0005] A main object of the present invention is to provide a process of controlling an operation of an electric kettle, wherein the controlling process is integrated with different individual processes to accurately control the operation of the electric kettle.
[0006] Accordingly, in order to accomplish the above object, the present invention provides a process of controlling an operation of an electric kettle for containing a predetermined volume of water therein, wherein the process comprises the steps of:
[0007] (a) initializing a microprocessor to detect a temperature of water in the electric kettle so as to set a system parameter;
[0008] (b) checking a status of the control circuit whether the control circuit is either at “ON” mode or “OFF” mode;
[0009] (c) determining a preserve temperature of the water for maintaining the water at the preserve temperature;
[0010] (d) checking a status of a cut off circuit for preventing the water from being totally evaporated;
[0011] (e) determining a condition of the water whether the water is needed to be heated up or preserved at the preserve temperature; and
[0012] (f) sending out a control signal to the control circuit in responsive to the condition of the water in order to heat up the water or maintain the water at the preserve temperature.
[0013] According to the preferred embodiment, after the water is either heated up or maintained at the preserve temperature in the step (f), the process returns back to the step (a) to form a loop control.
[0014] Accordingly, the microprocessor of the electric kettle comprises a temperature sensor having two spaced apart detecting points to detect the water temperature five times per second so as to accurately determine the water temperature by the average of the values at the detecting points in one second.
[0015] The microprocessor of the present system contains the parameters of a preset heat up cycle, the maximum heat up time and a parameter of “heat up and preserve”, wherein the parameters of the microprocessor are used for incorporating with different water capacities of the kettle bodies and different heating powers in order to set the optimized heat up cycles and the maximum heat up time.
[0016] The microprocessor of the present invention determines the status of the heat up circuit. When the heat up circuit is at an operation state, i.e. either the heat up mode or the preserve mode, the microprocessor determines the time required for heating up the water. When the heat up circuit is at an idle state, the microprocessor determines the heat up time is zero.
[0017] The microprocessor also determines the water whether is in preserve status. When the heat up circuit is at the preserve mode, the microprocessor compares the average value between the two detecting points with the preset temperature threshold. When the average value is larger than a lower limit of the preset temperature threshold, the detecting points are checked whether the detecting points are normally operated after the time period of heating up. When the average value is smaller than the lower limit of the preset temperature threshold, the detecting points are checked whether the detecting points are normally operated. When the heat up circuit is not in the preserve mode, i.e. the idle state, the detecting points are checked whether the detecting points are normally operated. If the detecting points are operated abnormally, the heat up circuit is automatically cut off and an alarm signal is generated. When the detecting points are normally operated, the detecting points are protected to prevent the detecting points from being burnt when the detecting points does not contact with the water.
[0018] The microprocessor also determines whether the water is needed to be heated up or preserved at the preserve temperature. Firstly, the microprocessor must receive a request signal before the microprocessor determines the water is needed to be heated up or preserved. When a heat up request signal is received by the microprocessor, the microprocessor will send out a heat up control signal to the control circuit so as to control the process of heating up the water in the kettle body until the water is boiled.
[0019] The microprocessor also determines whether there is a heat up request signal. Accordingly, the microprocessor determines whether there is a preserve request signal when the microprocessor does not receive any heat up request signal. If there is no preserve request signal, the process will return back to its initial state. When there is a preserve request signal, the microprocessor will verify whether the preserve request signal is a “heat up and preserve” request signal.
[0020] The microprocessor also determines whether there is a “heat up and preserve” request signal. If there is the “heat up and preserve” request signal, the heat up request signal is sent to the control circuit to heat up the water in the kettle body, wherein after the water is heated up, the water is maintained at the preserve temperature. If the preserve request signal is not the “heat up and preserve” request signal, the preserve request signal is sent to the control circuit for maintaining the water at the preserve temperature.
[0021] The microprocessor also protects the detecting points of the temperature sensor from being “dry” burnt. The microprocessor determines the temperature rate change in responsive to the average water temperature at the detecting points of the temperature sensor, so as to compare the temperature rate change with the preset threshold. When the temperature rate change is larger than the preset change threshold, the microprocessor sends out the control signal to the control circuit to stop heating up the water and to generate an alarm signal. When the temperature rate change is smaller than the preset change threshold, the microprocessor will determine the temperature acceleration by the temperature change with respect to time. When the temperature acceleration is larger than the preset acceleration threshold, the power of the heat up circuit is cut off and the alarm signal is generated. In addition, when the continuous heat up time is longer than the preset maximum heat up time, the power of the heat up circuit is cut off and the alarm signal is generated. During the microprocessor controls the heating up process, the microprocessor determines the current temperature rate change and compares the temperature rate change with the previous temperature change. When the current rate change tends to get closer to the previous rate change, the control circuit will stop sending out the heat up signal to stop heating up the water. During the microprocessor controls the preserve process, the microprocessor is arranged to maintain the water at the preserve temperature. When the average water temperature is lower than a safety threshold in which the safety threshold is a preset temperature for the user safely drinking the water, the microprocessor sends out the control signal to the control circuit to heat up the water. When the average water temperature is higher than or equal to the safety threshold, the microprocessor sends out the control signal to the control circuit to stop heating up the water. The actual water temperature, i.e. the average temperature, is compared with the preset temperature threshold when the microprocessor sends out the control signal to the control circuit to heat up the water. When the actual water temperature is higher than the preset temperature threshold, the microprocessor sends out the control signal to the control circuit to stop heating up the water. When the actual water temperature is smaller than the preset temperature threshold, the microprocessor determines the temperature rate change to compare with the preset temperature rate change threshold. When the temperature rate change is larger than the preset temperature rate change threshold, the microprocessor sends the control signal to the control circuit to stop heating up the water. When the temperature rate change is smaller than the preset temperature rate change threshold, the microprocessor sends the control signal to the control circuit to time-delay the stop of heating up the water.
[0022] The control process of the present invention contains distinctive features in comparison with the conventional control process for the electric kettle. The present invention incorporates with the microprocessor to control the water temperature in the kettle body, to determine the system parameters, to verify the status of the heat up circuit, to determine the water at the preserve state, to prevent the detecting points of the temperature sensor from being “dry” burnt, and to control both the heat up and preserve processes. The present invention integrates with different individual processes into one single process to control the operation of the electric kettle. In other words, by incorporating with the microprocessor, the present invention is adapted to accurately control the whole process of the electric kettle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is block diagram of a process of controlling an operation of an electric kettle according to a preferred embodiment of the present invention.
[0024] FIG. 2-1 is a flow diagram of the process of controlling an operation of an electric kettle according to the above preferred embodiment of the present invention.
[0025] FIG. 2-2 is a continuous flow diagram from FIG. 2-1 of the process of controlling an operation of an electric kettle according to the above preferred embodiment of the present invention.
[0026] FIG. 3 is a flow diagram of the process of cut off circuit for preventing the water from being totally evaporated according to the above preferred embodiment of the present invention.
[0027] FIG. 4-1 is a flow diagram of the process for maintaining the water at the preserve temperature according to the above preferred embodiment of the present invention.
[0028] FIG. 4-2 is a continuous flow diagram from FIG. 4-1 of the process for maintaining the water at the preserve temperature according to the above preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] Referring to FIG. 1 of the drawings, a process of controlling an operation of an electric kettle according to a preferred embodiment of the present invention is illustrated, wherein the electric kettle comprises a kettle body for containing a predetermined volume of water. The controlling process comprises the following steps.
[0030] (1) Preset a temperature sensor, a microprocessor and a control circuit at the electric kettle.
[0031] (2) After the power of the electric kettle is on, detect a temperature of water in the electric kettle via the temperature sensor and send the detection signal to the microprocessor.
[0032] (3) Preset a system parameter by the microprocessor.
[0033] (4) Check a status of the heat-up circuit whether the heat-up circuit is either at “ON” mode or “OFF” mode and determine a heat up time period for continuously heating up the water.
[0034] (5) Determine a preserve status of water for maintaining the water at a preserve temperature within a predetermined preserve cycle and time period.
[0035] (6) Check the temperature sensor whether the detecting point of the temperature sensor is in a normal operation mode.
[0036] (7) Check a status of a cut off circuit in a controllable manner, wherein the cut off circuit is arranged to cut off the power of the control circuit for preventing the water from being totally evaporated.
[0037] (8) Determine a condition of the water whether the water is needed to be heated up or preserved at the preserve temperature.
[0038] (9) Send out a control signal to the control circuit in responsive to the condition of the water in order to heat up the water or maintain the water at the preserve temperature.
[0039] (10) Return to the step (1) after the water is heated up or maintained at the preserve temperature in the step (9).
[0040] Referring to FIG. 2-1 and FIG. 2-2 of the drawings, the microprocessor controls the temperature sensor to detect the water temperature in the electric kettle five times per second. Accordingly, the temperature sensor contains at least two detecting points provided at a bottom wall and a peripheral edge of a kettle body of the electric kettle respectively to detect the temperature of the water in the kettle body. The water temperature is determined by averaging the values at the detecting points measured in one second. The microprocessor contains 10 sets of heat up cycles, 10 set of maximum heat up time and an operation code of “temperature maintain after heat up”. The parameters of the microprocessor are used for incorporating with different water capacities of the kettle bodies and different heating powers thereof in order to set the optimized heat up cycle and the maximum heat up time. The microprocessor comprises a A/D converter (analogy to digital converter) that the operation code is obtained through an input terminal of the A/D converter, wherein the corresponding parameters can be determined to match with the corresponding set of heat up cycle and maximum heat up time for the capacity of the kettle body and the heating power thereof, and to verify whether the water in the kettle body needed to be maintain at the preserve temperature after the water is heated up. The microprocessor also checks the status of the heat up circuit that whether the relay of the heat up circuit is in closed position and whether the water is in heating process. When the heat up circuit is switched on, the microprocessor determines the time period required for continuously heating up the water. When the heat up circuit is switched off, the time threshold determined by the microprocessor for heating up the water is zero. In other words, the water is stopped from being heated up.
[0041] When the microprocessor determines the water is in preserve status, the control circuit is set for maintaining the water at the preserve temperature. Accordingly, the detecting points will be checked at any state. When the heat up circuit is at the preserve mode, the microprocessor compares the average value between the two detecting points with the preset temperature threshold. When the average value is larger than a lower limit of the preset temperature threshold, the detecting points are checked whether the detecting points are normally operated after the time period of heating up. When the average value is smaller than a lower limit of the preset temperature threshold, the detecting points are checked whether the detecting points are normally operated. When the heat up circuit is not in the preserve mode, the detecting points are checked whether the detecting points are normally operated. The detecting points are also checked whether the detecting points are normally operated when the rate change of the heat up cycle. If the detecting points are operated abnormally, the heat up circuit is automatically cut off and an alarm signal is generated. It is worth to mention that when the detecting points are normally operated, the detecting points are protected to prevent the detecting points from being burnt when the detecting points does not contact with the water.
[0042] The microprocessor must receive a request signal before the microprocessor determines the water is needed to be heated up or preserved. When a heat up request signal is received by the microprocessor, the microprocessor will send out a heat up control signal to the control circuit so as to control the process of heating up the water in the kettle body until the water is boiled. The microprocessor determines whether there is a preserve request signal when the microprocessor does not receive any heat up request signal. If there is no preserve request signal, the process will return back to its initial state. When there is a preserve request signal, the microprocessor will verify whether the preserve request signal is a “heat up and preserve” request signal. If there is the “heat up and preserve” request signal, the heat up request signal is sent to the control circuit to heat up the water in the kettle body, wherein after the water is heated up, the water is maintained at the preserve temperature. If the preserve request signal is not the “heat up and preserve” request signal, the preserve request signal is sent to the control circuit for maintaining the water at the preserve temperature.
[0043] The microprocessor controls the process of heating up the water by determining the rate change of the water temperature. Accordingly, the microprocessor compares the current rate change of the water temperature with a previous rate change of the water temperature. When the current rate change tends to get closer to the previous rate change, the control circuit will stop sending out the heat up signal. Therefore, once the water is heated up, the process will return back to its initial state.
[0044] As shown in FIG. 3 , when the microprocessor is protected to prevent the microprocessor from being “dry” burnt, the control circuit is electrically connected to the heating source. When the continuous heat up time is longer than the preset maximum heat up time, the power of the heat up circuit is cut off and the alarm signal is generated. When the continuous heat up time is shorter than the preset maximum heat up cycle, the temperature sensor will keep detecting the water temperature. When the water temperature is higher than the preset temperature threshold, the power of the heat up circuit is cut off and the alarm signal is generated. When the water temperature is lower than the preset temperature threshold, the microprocessor will compare the temperature change with the preset change threshold. When the temperature change is larger than the preset change threshold, the power of the heat up circuit is cut off and the alarm signal is generated. When the temperature change is smaller than the preset change threshold, the microprocessor will determine the temperature acceleration by the temperature change with respect to time. When the temperature acceleration is larger than the preset acceleration threshold, the power of the heat up circuit is cut off and the alarm signal is generated. When the temperature acceleration is smaller than the preset acceleration threshold, the microprocessor will keep the current temperature change.
[0045] As shown in FIGS. 4-1 and 4 - 2 , when the microprocessor controls the preserve process, the microprocessor initially determines whether the water is heated up to maintain at the preserve temperature. If not, the microprocessor will determine whether the water temperature is larger than the preset temperature threshold. If the water temperature is smaller than the preset temperature threshold, the heat up control signal is sent to the control circuit to close the circuit thereof for heating up the water.
[0046] The microprocessor compares the actual water temperature with a set of preset temperature thresholds, wherein values of the preset temperature thresholds are sorted in an ascending order. Firstly, the microprocessor compares the actual water temperature with the lowest value of the preset temperature threshold, wherein when the actual water temperature is higher than the lowest value of the preset temperature threshold, the microprocessor then compares the actual water temperature with the subsequently preset temperature threshold and so on. When the actual water temperature is higher than the highest value of the preset temperature threshold, the microprocessor will send the control signal to the control circuit to stop heating up the water. Accordingly, the set of preset temperature thresholds contains five different values, i.e. from the lowest first value to the highest fifth value, sorted in an ascending order. When the actual water temperature is higher than the corresponding preset temperature threshold, the microprocessor will determine the temperature rate change correspondingly, wherein the temperature rate change is then added to the preset adjustment threshold and the microprocessor will save the value thereof. The preset adjustment threshold contains four different values, i.e. from the lowest first value to the highest fourth value, sorted in an ascending order. It is worth to mention that the preset adjustment threshold is set in responsive to the temperature rate change of the water when the water is heated up. The saved value is compared with the highest value of the preset adjustment threshold. When the saved value is smaller than the highest value of the preset adjustment threshold, the saved value will then compare with the subsequent value of the preset adjustment threshold until the saved value compares with the lowest value of the preset adjustment threshold. In addition, the saved value will also compare with the preset regulation threshold, wherein the preset regulation threshold contains six different values, i.e. from the highest sixth value to the lowest first value, sorted in a descending order. The saved value is compared with the highest value of the preset regulation threshold, wherein when the saved value is lower than the highest value of the preset regulation threshold, the saved value is then compared with the subsequent value of the preset regulation threshold until the saved value is compared with the lowest value of the preset regulation threshold. When the saved value is higher than the corresponding value of the preset regulation threshold, a preset heat up time threshold is obtained, wherein the heat up time threshold is preset in responsive to the corresponding preset regulation threshold. Accordingly, the preset heat up time threshold contains seven different values, i.e. from the lowest zero value to the highest seventh value, sorted in an ascending order. It is worth to mention that the preset regulation threshold is set to determine the time required for heating up the water.
[0047] The first saved value is zero when the actual water temperature is smaller than the first value of the preset temperature threshold. The microprocessor determines the temperature rate change when the actual water temperature is smaller than the second value of the preset temperature threshold, wherein the temperature rate change is added to the first value of the preset adjustment threshold to form the second saved value. The microprocessor determines the temperature rate change when the actual water temperature is smaller than the third value of the preset temperature threshold, wherein the temperature rate change is added to the second value of the preset adjustment threshold to form the third saved value. The microprocessor determines the temperature rate change when the actual water temperature is smaller than the fourth value of the preset temperature threshold, wherein the temperature rate change is added to the third value of the preset adjustment threshold to form the fourth saved value. The microprocessor determines the temperature rate change when the actual water temperature is smaller than the fifth value of the preset temperature threshold, wherein the temperature rate change is added to the fourth value of the preset adjustment threshold to form the fifth saved value.
[0048] When the saved value is larger than the sixth value of the preset regulation threshold, the heat up time threshold is zero that the water does not require any heating process. The time period for heating up the water is set as the first heat up time threshold when the saved value is larger than the fifth value of the preset regulation threshold. The time period for heating up the water is set as the second heat up time threshold when the saved value is larger than the fourth value of the preset regulation threshold. The time period for heating up the water is set as the third heat up time threshold when the saved value is larger than the third value of the preset regulation threshold. The time period for heating up the water is set as the fourth heat up time threshold when the saved value is larger than the second value of the preset regulation threshold. The time period for heating up the water is set as the fifth heat up time threshold when the saved value is larger than the first value of the preset regulation threshold. The time period for heating up the water is set as the sixth heat up time threshold when the saved value is smaller than the first value of the preset regulation threshold.
[0049] The various values of the temperature threshold are arranged for determining the saved value formed by adding the temperature rate change to the preset adjustment threshold, so as to compare with the corresponding regulation threshold. Alternatively, the actual water temperature can be directly compared with the preset temperature threshold. When the actual water temperature is smaller than the preset temperature threshold, the microprocessor determines the temperature rate change to compare with the preset temperature rate change threshold. When the temperature rate change is larger than the preset temperature rate change threshold, the microprocessor sends the control signal to the control circuit to stop heating up the water. When the temperature rate change is smaller than the preset temperature rate change threshold, the microprocessor sends the control signal to the control circuit to time-delay the stop of heating up the water.
[0050] Various water temperatures correspondingly match with various preset adjustment thresholds. Therefore, a corresponding heat up time threshold can be obtained. Accordingly, when the water temperature is increasing, the higher value of the preset adjustment threshold is obtained and the lower preset heat up time threshold is obtained. In other words, the water temperature is inverse proportion to the preset heat up time threshold such that when the water temperature is increasing, the time required for heating up the water is reduced.
[0051] The microprocessor further contains a heat up cycle in term of the maximum heat up time period. When the heat up time is larger or equal to the preset heat up time threshold, the microprocessor sends out the control signal to the control circuit to stop heating up the water within the heat up cycle and determines whether the heat up time is the full heat up cycle. When the heat up time is smaller that the preset heat up time threshold, the microprocessor not only sends out the control signal to the control circuit to continuously heat up the water but also determines whether the heat up time is the full heat up cycle. When the heat up time is the full completed heat up cycle, the temperature rate change is determined and the current water temperature is measured. Then, the heat up time is initialized to become zero value and the current water temperature is compared with the fifth value of the preset temperature threshold. When the current water temperature is larger than the fifth value of the preset temperature threshold, the control circuit receives the control signal to stop heating up the water. When the current water temperature is smaller than the fifth value of the preset temperature threshold, the water is continuously heated up. At the same time, the heat up time is continuously compared with the preset heat up time threshold. Once the preserve controlling process is completed, the system is initialized and returns to its initial state. | A process of controlling an operation of an electric kettle includes the steps of initializing a microprocessor to detect a water temperature via a temperature sensor to set a system parameter; checking a status of a control circuit; determining a preserve temperature of the water; verifying the temperature sensor to protect the temperature sensor from being burnt; determining a condition of the water whether the water is needed to be heated up or preserved; and sending out a control signal to the control circuit in responsive to the condition of the water to heat up the water or maintain the water at the preserve temperature. Therefore, the present invention is adapted to accurately control the whole process of the electric kettle. | 0 |
[0001] The invention relates to a white, flame-retardant, UV-resistant, thermoformable, oriented film made from a crystallizable thermoplastic, the thickness of the film being in the range from 10 to 350 μm. The film comprises at least one white pigment and one flame retardant and one UV absorber and has good orientability and thermoformability, and very good optical and mechanical properties, and can be produced cost-effectively. The invention further relates to the use of this film and to a process for its production.
BACKGROUND OF THE INVENTION
[0002] White, oriented films made from crystallizable thermoplastics with a thickness of from 10 to 350 μm are well known.
[0003] These films do not comprise UV absorbers of any kind as light stabilizers and do not comprise flame retardants of any kind, and therefore neither the films nor the items produced from them are suitable for outdoor applications which demand fire protection or flame retardancy. The films do not pass the fire tests to DIN 4102 Part 2 and Part 1, or the UL 94 test. The films have inadequate thermoformability.
[0004] Even after a short time in outdoor applications, these films yellow and exhibit impairment of mechanical properties due to photooxidative degradation by sunlight.
[0005] EP-A-0 620 245 describes films with improved heat resistance. These films comprise antioxidants which are suitable for scavenging free radicals formed in the film and degrading any peroxide formed. However, that specification gives no proposal as to how the UV resistance of these films might be improved.
[0006] DE-A 2346 787 describes a flame-retardant polymer. Alongside the polymer, the use of the polymer is also claimed for producing films or fibers.
[0007] The following shortcomings were apparent during production of films from this phospholane-modified polymer:
[0008] The polymer is very susceptible to hydrolysis and has to be very thoroughly predried. The polymer cakes during its drying by prior-art dryers, and it is impossible to produce a film except under the most difficult of conditions.
[0009] The films produced under extreme and uneconomic conditions embrittle on exposure to heat, i.e. the mechanical properties are severely impaired due to substantial embrittlement, making the film unusable. This embrittlement occurs after as little as 48 hours of exposure to heat.
[0010] It was an object of the present invention to provide a white, flame-retardant, UV-resistant, thermoformable, oriented film with a thickness of from 10-350 μm which not only can be produced cost-effectively and has good orientability and good mechanical and optical properties, but in particular is flame retardant, does not embrittle on exposure to heat, is thermoformable, and has high UV resistance.
[0011] Flame retardancy means that in a fire test the white film complies with the conditions of DIN 4102 Part 2 and in particular the conditions of DIN 4102 Part 1, and can be allocated to construction materials class B 2 and in particular B 1 for low-flammability materials.
[0012] The film is also intended to pass the UL 94 test “Vertical Burning Test for Flammability of Plastic Material”, permitting its classification in class 94 VTM-0. This means that 10 seconds after removal of the Bunsen burner the film has ceased to burn, and after 30 seconds no glowing is observed, and no drips are found to occur.
[0013] High UV resistance means that sunlight or other UV radiation causes no, or only extremely little, damage to the films, so that the films are suitable for outdoor applications and/or critical indoor applications. In particular, after a number of years in outdoor applications the films are intended not to yellow, nor to exhibit any embrittlement or surface cracking, nor to exhibit any impairment of mechanical properties. High UV resistance therefore means that the film absorbs UV light and does not transmit light until the visible region has been reached.
[0014] Thermoformability means that the film can be thermoformed to give complex and large-surface-area moldings on commercially available thermoforming machinery, without uneconomic predrying.
[0015] Examples of good optical properties include uniform coloration, high surface gloss (>15), low light transmission (<70%), and also a Yellowness Index unchanged from that of the flame-retardant and UV-modified film.
[0016] Good mechanical properties include high modulus of elasticity (E MD >3200 N/mm 2 : E TD >3500 N/mm 2 ), and also good values for tensile stress at break (in MD >100 N/mm 2 ; in TD >130 N/mm 2 ).
[0017] Good orientability includes the capability of the film to give excellent orientation, both in a longitudinal direction and I transverse direction during its production, without break-offs.
[0018] Cost-effective production includes the capability of the raw materials or raw material components needed to produce the flame-retardant film to be dried using industrial-standard dryers. It is important that the raw materials neither cake nor become thermally degraded. These prior-art industrial dryers include vacuum dryers, fluidized-bed dryers, fixed-bed dryers (tower dryers). These dryers operate at temperatures of from 100 to 170° C., at which the flame-retardent polymers cake and have to be dug out, making film production impossible.
[0019] In the case of the vacuum dryer, which provides the mildest drying conditions, the raw material traverses a temperature range from about 30 to 130 ° C., under a vacuum of 50 mbar. Post-drying is then needed in a hopper at temperatures from 100 to 130° C. with a residence time of from 3 to 6 hours. Here, too, this polymer cakes to an extreme extent.
BRIEF DESCRIPTION OF THE INVENTION
[0020] This object is achieved by means of a white thermoformable film with a thickness in the range from 10 to 350 μm, which comprises a crystallizable thermoplastic principal constituent, and comprises at least one white pigment, at least one UV absorber, and at least one flame retardant, where expediently the UV absorber and according to invention the flame retardant are fed directly as masterbatch during the production of the film.
DETAILED DESCRIPTION OF THE INVENTION
[0021] The white, flame-retardant, UV-resistant, thermoformable, oriented film comprises, as principal constituent, a crystallizable thermoplastic. Examples of suitable crystallizable or semicrystalline thermoplastics are polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, preferably polyethylene terephthalate.
[0022] According to the invention, crystallizable thermoplastics are crystallizable homopolymers, crystallizable copolymers, crystallizable compounded materials (mixtures), crystallizable recycled material, and other types of crystallizable thermoplastics.
[0023] The white film may be either a single-layer or a multilayer film. The film may also have a coating of various copolyesters or adhesion promoters.
[0024] According to the invention, the white film comprises a UV absorber and a flame retardant. The UV absorber is expediently fed directly during the production of the film by way of masterbatch technology, the concentration of the UV stabilizer preferably being from 0.01 to 5% by weight, based on the weight of the layer of the crystallizable thermoplastic.
[0025] No embrittlement on brief exposure to heat means that after 100 hours of a heat-conditioning procedure at 100° C. in a circulating-air oven the film or the molding exhibits no embrittlement nor any poor mechanical properties.
[0026] The film of the invention comprises at least one flame retardant, fed directly during the production of the film by way of masterbatch technology, the concentration of the flame retardant being in the range from 0.5 to 30.0% by weight, preferably from 1.0 to 20.0% by weight, based on the weight of the layer of the crystallizable thermoplastic. The ratio of flame retardant to thermoplastic maintained during production of the masterbatch is generally in the range from 60:40% by weight to 10:90% by weight.
[0027] Typical flame retardants include bromine compounds, chloroparaffins, and 10 other chlorine compounds, antimony trioxide, aluminum trihydrates, the halogen compounds being disadvantageous due to the halogen-containing by-products produced. Another extreme disadvantage is the low lighffastness of a film modified therewith, alongside the evolution of hydrogen halides in the event of a fire.
[0028] Examples of suitable flame retardants used according to the invention are organophosphorus compounds, such as carboxyphosphinic acids, anhydrides of these, and dimethyl methylphosphonate. It is important for the invention that the organophosphorus compound is soluble in the thermoplastic, since otherwise the optical properties required are not complied with.
[0029] Since the flame retardants generally have some susceptibility to hydrolysis, it can be advisable to add a hydrolysis stabilizer.
[0030] Hydrolysis stabilizers used are generally phenolic stabilizers, alkali metal/alkaline earth metal stearates, and/or alkali metal/alkaline earth metal carbonates, in amounts of from 0.01 to 1.0% by weight. It is preferable to use amounts of from 0.05 to 0.6% by weight, in particular from 0.15 to 0.3% by weight, of phenolic stabilizers having a molar mass above 500 g/mol. Particularly advantageous compounds are pentaerythrityl tetrakis-3-(3,5-di-tert-butyl-4-hydroxphenyl) propionate or 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene.
[0031] The white pigment is preferably fed by way of masterbatch technology, but may also be incorporated directly at the premises of the polymer producer. The concentration of the white pigment is from 0.2 to 40% by weight, preferably from 0.5 to 25% by weight, based on the weight of the crystallizable thermoplastic.
[0032] Preferred suitable white pigments are titanium dioxide, barium sulfate, calcium carbonate, kaolin, silicon dioxide, preferably titanium dioxide and barium sulfate.
[0033] The titanium dioxide particles may be composed of anatase or rutile, preferably predominantly of rutile, which has higher opacifying power than anatase.
[0034] In a preferred embodiment, the titanium dioxide particles are composed of at least 95% by weight of rutile. They may be prepared by a conventional process, e.g.: by the chloride process or the sulfate process. The amount of these in the base layer is from 0.3 to 25% by weight, based on the base layer, and the average particle size is relatively small, preferably in the range from 0.10 to 0.30 μm.
[0035] Titanium dioxide of the type described does not produce any vacuols within the polymer matrix during the production of the film.
[0036] The titanium dioxide particles may have the type of covering usually used as a covering for TiO 2 white pigment in papers or paints to improve lightfastness, made from inorganic oxides.
[0037] TiO 2 is known to be photoactive. On exposure to UV radiation, free radicals form on the surface of the particles. These free radicals can migrate into the film-forming polymers, causing degradation reactions and yellowing.
[0038] Particularly suitable oxides include the oxides of aluminum, silicon, zinc, or magnesium, and mixtures made from two or more of these compounds. TiO 2 particles with a covering made from two or more of these compounds are described by way of example in EP-A-0 044 515 and EP-A-0 078 633. The coating may also comprise organic compounds having polar and non-polar groups. The organic compounds have to have adequate thermal stability during production of the film by extrusion of the polymer melt. Examples of polar groups are —OH, —OR, —COOX (X═R, H, or Na, R=alkyl having from 1 to 34 carbon atoms). Preferred organic compounds are alkanols and fatty acids having from 8 to 30 carbon atoms in the alkyl group, in particular fatty acids and primary n-alkanols having from 12 to 24 carbon atoms, and also polydiorganosiloxanes and/or polyorganohydrosiloxanes, e.g. polydimethylsiloxane and polymethylhydrosiloxane.
[0039] The coating for the titanium dioxide particles is usually composed of from 1 to 12 g, in particular from 2 to 6 g, of inorganic oxides, and from 0.5 to 3 g, in particular from 0.7 to 1.5 g, of organic compounds, based on 100 g of titanium dioxide particles. The covering is applied to the particles in aqueous suspension. The inorganic oxides may be precipitated from water-soluble compounds, e.g. alkali metal nitrate, in particular sodium nitrate, sodium silicate (waterglass), or silica, in the aqueous suspension.
[0040] For the purposes of the present invention, inorganic oxides, such as Al 2 O 3 or SiO 2 , also include the hydroxides and their various stages of dehydration, e.g. oxide hydrate, the precise composition and structure of which is not known. The oxide hydrates, e.g. of aluminum and/or of silicon, are precipitated onto the calcined and ground TiO 2 pigment, in aqueous suspension, and the pigments are then washed and dried. This precipitation may therefore take place directly in a suspension such as that produced within the production process after calcination followed by wet-grinding. The oxides and/or oxide hydrates of the respective metals are precipitated from the water-soluble metal salts within the known pH range: for example, for aluminum use is made of aluminum sulfate in aqueous solution (pH below 4), and the oxide hydrate is precipitated within the pH range from 5 to 9, preferably from 7 to 8.5, by addition of aqueous ammonia solution or sodium hydroxide solution. If the starting material is waterglass solution or alkali metal aluminate solution, the pH of the initial charge of TiO 2 suspension should be within the strongly alkaline range (pH above 8). The precipitation then takes place within the pH range from 5 to 8, by addition of mineral acid, such as sulfuric acid. Once the metal oxides have been precipitated, the stirring of the suspension continues for from 15 min to about 2 h, aging the precipitated layers. The coated product is separated off from the aqueous dispersion, washed, and dried at an elevated temperature, in particular at from 70 to 100° C.
[0041] Light, in particular the ultraviolet content of solar radiation, i.e. the wavelength region from 280 to 400 nm, induces degradation in thermoplastics, as a result of which their appearance changes due to color change or yellowing, and there is also an adverse effect on mechanical/physical properties.
[0042] Inhibition of this photooxidative degradation is of considerable industrial and economic importance, since otherwise there are drastic limitations on the applications of many thermoplastics.
[0043] Absorption of UV light by polyethylene terephthalates, for example, starts at below 360 nm, increases markedly below 320 nm, and is very pronounced at below 300 nm. Maximum absorption occurs at from 280 to 300 nm.
[0044] In the presence of oxygen it is mainly chain cleavage which occurs, without any crosslinking. The predominant photooxidation products in quantity terms are carbon monoxide, carbon dioxide, and carboxylic acids. Besides the direct photolysis of the ester groups, consideration has to be given to oxidation reactions which likewise form carbon dioxide, via peroxide radicals.
[0045] In the photooxidation of polyethylene terephthalates there can also be cleavage of hydrogen at the position α to the ester groups, giving hydroperoxides and decomposition products of these, and this may be accompanied by chain cleavage (H. Day, D. M. Wiles: J. Appl. Polym. Sci 16, 1972, p. 203).
[0046] UV stabilizers, i.e. light stabilizers which are UV absorbers, are chemical compounds which can intervene in the physical and chemical processes of light-induced degradation. Carbon black and other pigments can give some protection from light. However, these substances are unsuitable for transparent films, since they cause discoloration or color change. The only compounds suitable for transparent matt films are organic and organometallic compounds which produce no, or only extremely slight, color or color change in the thermoplastic to be stabilized, i.e. those which are soluble in the thermoplastic.
[0047] For the purposes of the present invention, UV stabilizers suitable as light stabilizers are those which absorb at least 70%, preferably 80%, particularly preferably 90%, of the UV light in the wavelength region from 180 to 380 nm, preferably 280 to 350 nm. These are particularly suitable if they are thermally stable in the temperature range from 260 to 300° C., i.e. neither decompose nor give rise to release of gases. Examples of UV stabilizers suitable as light stabilizers are 2-hydroxybenzophenones, 2-hydroxybenzotriazoles, organonickel compounds, salicylic esters, cinnamic ester derivatives, resorcinol monobenzoates, oxanilides, hydroxybenzoic esters, and sterically hindered amines and triazines, preference being given to the 2-hydroxybenzotriazoles and the triazines.
[0048] The UV stabilizer(s) are preferably present in the outer layer(s). The core layer may also have UV stabilizer, if required.
[0049] It was highly surprising that the use of the abovementioned UV stabilizers in films gave the desired result. The skilled worker would probably first have attempted to achieve a certain degree of UV resistance by way of an antioxidant, but would have found that the film rapidly yellows on weathering.
[0050] In the knowledge that UV stabilizers absorb UV light and therefore provide protection, the skilled worker would be likely to have used commercially available stabilizers. He would then have observed that
[0051] the UV stabilizer has unsatisfactory thermal stability, and at temperatures of from 200 to 240° C. decomposes and gives rise to release of gases, and
[0052] large amounts (from about 10 to 15% by weight) of the UV stabilizer have to be incorporated in order to absorb the UV light and thus prevent damage to the film.
[0053] At these high concentrations it would have been observed that the film is yellow even just after it has been produced, with Yellowness Indices (YI) of around 25. It would also have been observed that the mechanical properties of the film have been adversely affected. Orientation would have produced exceptional problems, such as
[0054] break-offs due to unsatisfactory strength, i.e. excessively low modulus of elasticity;
[0055] die deposits, causing profile variations;
[0056] roller deposits from the UV stabilizer, causing impairment of optical properties (defective adhesion, non-uniform surface);
[0057] deposits in stretching frames or heat-setting frames, dropping onto the film.
[0058] It was therefore more than surprising that even low concentrations of the UV stabilizer achieve excellent UV protection. It was very surprising that, together with this excellent UV protection,
[0059] within the accuracy of measurement, the Yellowness Index of the film is unchanged from that of an unstabilized film;
[0060] there are no releases of gases, no die deposits, and no frame condensation, and the film therefore has excellent optical properties and excellent profile and layflat, and
[0061] the UV-resistant film has excellent stretchability, and can therefore be produced in a reliable and stable manner on high-speed film lines at speeds of up to 420 m/min.
[0062] It was more than surprising that the use of masterbatch technology and of appropriate predrying and/or precrystallization and, where appropriate, use of small amounts of a hydrolysis stabilizer permit the production of a flame-retardant and thermoformable film with the property profile demanded in a cost-effective manner and without caking in the dryer, and that the film does not embrittle on exposure to heat and does not fracture when creased. It was very surprising that together with this excellent result and the required flame retardancy, and the thermoformability and high UV resistance
[0063] within the accuracy of measurement, the Yellowness Index of the film is not adversely affected when compared with that of an unstabilized film;
[0064] there are no releases of gases, no die deposits, and no frame condensation, and the film therefore has excellent optical properties and excellent profile and layflat, and
[0065] the flame-retardant UV-resistant film has excellent stretchability, and can therefore be produced in a reliable and stable manner on high-speed film lines at speeds of up to 420 m/min.
[0066] With this, the film is also cost-effective.
[0067] It was also surprising that a higher diethylene glycol content and/or polyethylene glycol content and/or IPA content than that of standard thermoplastics permits cost-effective thermoforming of the films on commercially available thermoforming plants, and gives the films capability for excellent reproduction of detail.
[0068] It is moreover very surprising that it is also possible to reuse the regrind produced from the films or from the moldings without adversely affecting the Yellowness Index of the film.
[0069] In one preferred embodiment, the white, flame-retardant film of the invention comprises, as principal constituent, a crystallizable polyethylene terephthalate having a diethylene glycol content of ≧1.0% by weight, preferably ≧1.2% by weight, in particular ≧1.3% by weight, and/or a polyethylene glycol content (PEG content) of ≧1.0% by weight, preferably ≧1.2% by weight, in particular ≧1.3% by weight, from 1 to 20% by weight of an organic phosphorus compound (dimethyl methylphosphonate) as flame retardant soluble in the polyethylene terephthalate, from 0.01 to 5.0% by weight of a UV absorber selected from the group of the 2-hydroxybenzotriazoles or the triazines and soluble in the PET, and from 0.5 to 25% by weight of titanium dioxide whose preferred particle diameter is from 0.10 to 0.50 μm, preferably a rutile-type titanium dioxide. Instead of titanium dioxide, it is also possible to use barium sulfate whose particle diameter is from 0.20 to 1.20 μm as white pigment, the concentration being from 1.0 to 25% by weight. In one preferred embodiment, it is also possible to use a mixture of these white pigments, or a mixture of one of these white pigments with another white pigment.
[0070] In one particularly preferred embodiment, the film of the invention comprises from 0.01 to 5.0% by weight of 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-(hexyl) oxyphenol of the formula
[0071] or from 0.01 to 5.0% by weight of 2,2′-methylenebis(6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethyl-butyl)phenol of the formula
[0072] In one preferred embodiment, it is also possible to use a mixture of these two UV stabilizers, or a mixture of at least one of these two UV stabilizers with other UV stabilizers, the total concentration of light stabilizer preferably being from 0.01 to 5.0% by weight, based on the weight of crystallizable polyethylene terephthalate.
[0073] In the invention it is important for thermoformability that the crystallizable thermoplastic has a diethylene glycol content (DEG content) of ≧1.0% by weight, preferably ≧1.2% by weight, in particular ≧1.3% by weight, and/or a polyethylene glycol content (PEG content) of ≧1.0% by weight, preferably ≧1.2% by weight, in particular ≧1.3% by weight, and/or an isophthalic acid content (IPA) of from 3 to 10% by weight.
[0074] The white, UV-resistant, thermoformable, flame-retardant film has the following property profile:
[0075] surface gloss, measured to DIN 67530 (measurement angle 20°), is greater than 15, preferably greater than 20, and light transmittance L, measured to ASTM D 1003, is less than 70%, preferably less than 60%, measured to ASTM S 1003, this being surprisingly good for the UV resistance achieved in combination with the flame retardancy.
[0076] Standard viscosity SV (DCA) of the polyethylene terephthalate, measured in dichloroacetic acid to DIN 53728 is from 600 to 1000, preferably from 700 to 900.
[0077] The white polyethylene terephthalate film which comprises at least one organic white pigment, one UV stabilizer, and one flame retardant may be either a single-layer film or a multilayer film.
[0078] In the multilayer embodiment, the film is built up from at least one corner layer and from at least one outer layer, preference being given in particular to a three-layer A-B-A or A-B-C structure.
[0079] For this embodiment it is important that standard viscosity and DEG content and/or PEG content of the polyethylene terephthalate of the core layer are similarto those of the polyethylene terephthalate of the outer layer(s) adjacent to the core layer.
[0080] In a particular embodiment, the outer layers may also be composed of a polyethylene naphthalate homopolymer or of a polyethylene terephthalate-polyethylene naphthalate copolymer, or of a compounded material.
[0081] Again in this embodiment, standard viscosity and DEG content and/or PEG content of the thermoplastics of the outer layers are similar to those of the polyethylene terephthalate of the core layer.
[0082] In the multilayer embodiment, the UV absorber is preferably present in the outer layers. If required, UV absorber may also have been provided in the core layer.
[0083] In the multilayer embodiment, the white pigment and the flame retardant are preferably present in the core layer. However, if required, white pigment and/or flame retardant may also have been provided in the outer layers.
[0084] In another embodiment it is also possible for white pigment, flame retardant and UV absorber to be present in the outer layers. If required and if fire protection requirements are stringent, the core layer may also have what is known as a “base level” of flame retardant.
[0085] Unlike in the single-layer embodiment, the concentration of the white pigment here, and of the flame retardant and of the UV stabilizer, is based on the weight in the modified layer. Highly surprisingly, weathering tests to the ISO 4892 test specification using the Atlas C165 Weather Ometer have shown that in order to achieve improved UV resistance for a three-layer film it is fully sufficient for the outer layers of thickness of from 0.5 to 2 μm to be provided with UV stabilizers. Fire tests to DIN 4102 Part 1 and Part 2, and also the UL 94 test have equally surprisingly shown that compliance of the film of the invention with the requirements extends to the range of thickness from 5 to 300 μm.
[0086] The flame-retardant, UV-resistant, thermoformable, multilayer films produced using known coextrusion technology are therefore of great economic interest when compared with monofilms provided with UV stabilizers and flame retardants throughout, since markedly less additives are needed for comparable flame retardancy and UV resistance.
[0087] At least one side of the film may also have been provided with a scratch-resistant coating, with a copolyester, or with an adhesion promoter.
[0088] Weathering tests have shown that even after from 5 to 7 years of outdoor use (extrapolated from the weathering tests) the flame-retardant UV-resistant films of the invention generally exhibit no increased yellowing, no embrittlement, no loss of surface gloss, no surface cracking, and no impairment of mechanical properties.
[0089] The results of measurements indicate that the film of the invention or the molding does not embrittle when exposed to heat at 100° C. over a prolonged period. This result is attributable to the synergistic action of appropriate precrystallization, predrying, masterbatch technology, and modification with UV stabilizer.
[0090] The film can be thermoformed without predrying, and can therefore be used to produce complex moldings.
[0091] The thermoforming process generally encompasses the steps of predrying, heating, molding, cooling, demolding, and heat-conditioning. Surprisingly, during the thermoforming process it was found that the films of the invention can be thermoformed without prior predrying. This advantage over thermoformable polycarbonate films or thermoformable polymethacrylate films, which require predrying times of from 10 to 15 hours, at temperatures of from 100 to 120° C., depending on thickness, drastically reduces the costs of the forming process.
[0092] The following process parameters for the thermoforming process were found:
Step of process Film of invention Predrying not required Temperature of mold ° C. from 100 to 160 Heating time <5 sec per 10 μm of film thickness Film temperature during from 160 to 220 thermoforming ° C. Possible orientation factor from 1.5 to 2.0 Reproduction of detail good Shrinkage (%) <1.5
[0093] The film of the invention or the molding produced therefrom can moreover be recycled without difficulty and without pollution of the environment, and without loss of mechanical properties, and is therefore suitable for use as short-lived advertising placards, for example, for the construction of exhibition stands, or for other promotional items where fire protection and thermoformability is desired.
[0094] An example of a method for producing the white, flame-retardant, thermoformable, UV-resistant film of the invention is the extrusion process on an extrusion line.
[0095] According to the invention, the flame retardant is added by way of masterbatch technology. The flame retardant is fully dispersed in a carrier material. Carrier materials which may be used are the thermoplastic itself, e.g. the polyethylene terephthalate, or else other polymers compatible with the thermoplastic.
[0096] According to the invention, the UV stabilizer and the white pigment may be fed before the material leaves the producer of the thermoplastic polymer, or during the production of the film, into the extruder.
[0097] DEG content and/or PEG content of the polyethylene terephthalate are set at the premises of the polymer producer during the polycondensation process.
[0098] Addition of the white pigment and of the UV stabilizer by way of masterbatch technology is particularly preferred. The UV stabilizer and, respectively, the white pigment is fully dispersed in a solid carrier material. Carrier materials which may be used are the thermoplastic itself, e.g. the polyethylene terephthalate, or else other polymers sufficiently compatible with the thermoplastic.
[0099] It is important in masterbatch technology that the grain size and the bulk density of the masterbatch are similar to the grain size and the bulk density of the thermoplastic, thus permitting uniform distribution and, with this, uniform UV resistance.
[0100] The polyester films may be produced by known processes from a polyester, where appropriate with other polymers, with the flame retardant, with the white pigment, with the UV absorber, and/or with other conventional additives in conventional amounts from 1.0 to not more than 30% by weight, either in the form of a monofilm or else in the form of multilayer, where appropriate coextruded films with surfaces of identical or different nature, for example pigment being present in one surface but no pigment being present in the other surface. It is also possible for one or both surfaces of the film to be provided with a conventional functional coating by known processes.
[0101] It is important for the invention that the masterbatch which comprises the flame retardant and, where appropriate, the hydrolysis stabilizer, is precrystallized or predried. This predrying includes progressive heating of the masterbatch at subatmospheric pressure (from 20 to 80 mbar, preferablyfrom 30 to 60 mbar, in particular from 40 to 50 mbar), with stirring, and, where appropriate, post-drying at a constant elevated temperature, again at subatmospheric pressure. The masterbatch is preferably charged at room temperature from a feed vessel in the desired blend with the polymers of the base and/or outer layers and, where appropriate, with other raw material components, batchwise in a vacuum dryer which during the course of the drying time or residence time traverses a temperature profile from 10 to 160° C., preferably from 20 to 150° C., in particular from 30 to 130° C. During the residence time of about 6 hours, preferably 5 hours, in particular 4 hours, the raw material mixture is stirred at from 10 to 70 rpm, preferably from 15 to 65 rpm, in particular from 20 to 60 rpm. The resultant precrystallized or predried raw material mixture is post-dried for from 2 to 8 hours, preferably from 3 to 7 hours, in particular from 4 to 6 hours, in a downstream vessel, likewise evacuated, at from 90 to 180° C., preferably from 100 to 170° C., in particular from 110 to 160° C.
[0102] In the preferred extrusion process for producing the polyester film, the molten polyester material is extruded through a slot die and, in the form of a substantially amorphous prefilm, quenched on a chill roll. This film is then reheated and stretched longitudinally and transversely, or transversely and longitudinally, or longitudinally, transversely, and again and longitudinally and/or transversely. The stretching temperatures are generally from T G +10° C. to T G +60° C. (T G =glass transition temperature), and the stretching ratio for longitudinal stretching is usually from 2 to 6, in particular from 3 to 4.5, and that for transverse stretching is from 2 to 5, in particular from 3 to 4.5, and that for any second longitudinal or transverse stretching carried out is from 1.1 to 5. The first longitudinal stretching may, where appropriate, take place simultaneously with transverse stretching (simultaneous stretching). Heat-setting of the film then follows with oven temperatures of from 180 to 260° C., in particular from 220 to 250° C. The film is then cooled and wound.
[0103] The surprising combination of exceptional properties gives the film of the invention excellent suitability for a wide variety of applications, for example for interior decoration, for exhibition stands or exhibition requisites, as displays, for placards, for protective glazing of machinery or of vehicles, in the lighting sector, in the fitting-out of shops or of stores, as a promotional item or laminating medium, for greenhouses, for roofing systems, external cladding, protective coverings, applications in the construction sector, and illuminated advertising profiles, blinds, or electrical applications.
[0104] Its thermoformability makes the film of the invention suitable for thermoforming desired moldings for indoor or outdoor applications.
[0105] The invention is further illustrated below using examples.
[0106] The following standards or methods are used here in measuring the individual properties.
TEST METHODS
[0107] DEG Content, PEG Content and IPA Content
[0108] DEG, PEG, or IPA content is determined by gas chromatography after dissolving the thermoplastic polymer in cresol.
[0109] Surface Gloss
[0110] Surface gloss is measured at a measurement angle of 20° to DIN 67530.
[0111] Light Transmittance
[0112] Light transmittance is the ratio of the total transmitted light to the amount of incident light. Light transmittance is measured using the “®HAZEGARD plus” tester to ASTM D 1003.
[0113] Haze
[0114] Haze is that percentage proportion of transmitted light which deviates by more than 2.50 from the average direction of the incident light beam. Clarity is determined at an angle of less than 2.50.
[0115] Haze is [lacuna] using the “HAZEGARD plus” tester to ASTM D 1003.
[0116] Surface Defects
[0117] Surface defects are determined visually.
[0118] Mechanical Properties
[0119] Modulus of elasticity and tensile stress at break, and tensile strain at break, are measured longitudinally and transversely to ISO 527-1-2.
[0120] SV (DCA), IV (DVA)
[0121] Standard viscosity SV (DCA) is measured by a method based on DIN 53726 in dichloroacetic acid.
[0122] Intrinsic viscosity (IV) is calculated from standard viscosity as follows
IV (DCA)=6.67·10 −4 SV(DCA)+0.118
[0123] Fire Performance
[0124] Fire performance is determined to DIN 4102 Part 2, construction materials class B2, and to DIN 4102 Part 1, construction materials class B1, and also to the UL 94 test.
[0125] Weathering (Bilateral), UV Resistance
[0126] UV resistance is tested as follows to the ISO 4892 test specification:
Tester Atlas Ci 65 Weather Ometer Test conditions Iso 4892, i.e. artificial weathering Irradiation time 1 000 hours (per side) Irradiation 0.5 W/m 2 , 340 nm Temperature 63° C. Relative humidity 50% Xenon lamp internal and external filter made from borosilicate Irradiation cycles 102 minutes of UV light, then 18 minutes of UV light with water spray on the specimens, then again 102 minutes of UV light, etc.
[0127] Yellowness Index
[0128] (YI) is the deviation from the colorless condition in the “yellow” direction and is measured to DIN 6167. Yellowness indices (YIs) <5 are not visually detectable.
[0129] In each case, the examples and comparative examples below use white films of varying thickness, produced on the extrusion line described.
[0130] All of the films were weathered bilaterally to ISO 4892 test specification, in each case for 1000 hours per side using the Atlas Ci 65 Weather Ometer from the company Atlas, and then tested for mechanical properties, Yellowness Index (YI), surface defects, light transmission, and gloss.
[0131] Fire tests to DIN 4102, Part 2 and Part 1, and the UL 94 test, were carried out on all of the films.
EXAMPLES
Example 1
[0132] A white film of 50 m thickness is produced and comprises, as principal constituent, polyethylene terephthalate, 7.0% by weight of titanium dioxide, and 1.0% by weight of the UV stabilizer 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-(hexyl)oxyphenol (®Tinuvin 1577 from the company Ciba-Geigy) and 2.0% by weight of flame retardant.
[0133] The titanium dioxide is of rutile type and has an average particle diameter of 0.20 μm, and has a coating of Al 2 O 3 . ®Tinuvin 1577 has a melting point of 149° C. and is thermally stable up to about 330° C.
[0134] For purposes of uniform distribution, the titanium dioxide and the UV absorber is incorporated into the PET directly at the premises of the polymer producer.
[0135] The flame retardant is the PET soluble organophosphorus compound Amgard P1045 from the company Albright & Wilson.
[0136] The flame retardant is fed in the form of a masterbatch. The masterbatch is composed of 10% by weight of flame retardant and 80% by weight of PET, and its bulk density is 750 kg/m 3 .
[0137] The PET from which the film is produced and the PET that is utilized for masterbatch production have standard viscosity SV (DCA) of 810, corresponding to intrinsic viscosity IV (DCA) of 0.658 dl/g. DEG content and PEG content are 1.6% by weight. 50% of the polyethylene terephthalate, 30% by weight of recycled polyethylene terephthalate material, and 20% by weight of the masterbatch are charged at room temperature from separate feed vessels in a vacuum dryer which from the juncture of charging to the end of the residence time traverses a temperature profile from 25 to 130° C. During the residence time of about 4 hours, the raw material mixture is stirred at 61 rpm.
[0138] The precrystallized or predried raw material mixture is post-dried in the downstream hopper, likewise under vacuum, at 140° C. for 4 hours. The 50 μm monofilm is then produced using the extrusion process described.
[0139] The individual steps of the process were:
Longitudinal Temperature: 85-135° C. stretching Longitudinal stretching ratio: 4.0:1 Transverse Temperature: 85-135° C. stretching Transverse stretching ratio: 4.0:1 Setting Temperature: 230° C.
[0140] The white PET film produced had the following property profile:
Thickness 50 μm Surface gloss side 1 72 (Measurement angle 20°) side 2 68 Light transmittance 28% Surface defects per m 2 none Longitudinal modulus of elasticity 3 700 N/mm 2 Transverse modulus of elasticity 4 800 N/mm 2 Longitudinal tensile stress at break 130 N/mm 2 Transverse tensile stress at break 205 N/mm 2 Yellowness Index (YI) 48 Coloration uniform
[0141] The film fulfills the requirements of construction materials classes B2 and B1 to DIN 4102 Part 2 and Part 1. The film passes the UL 94 test.
[0142] After 200 hours of heat-conditioning at 100 ° C. in a circulating-air drying cabinet the mechanical properties are unaltered. The film exhibits no embrittlement phenomena of any kind.
[0143] After in each case 1000 hours of weathering per side with the Atlas CI 65
[0144] Weather Ometer the PET film has the following properties:
Thickness 50 μm Surface gloss side 1 65 (Measurement angle 20°) side 2 60 Light transmittance 35% Surface defects per m 2 none Longitudinal modulus of elasticity 3 550 N/mm 2 Transverse modulus of elasticity 4 650 N/mm 2 Longitudinal tensile stress at break 118 N/mm 2 Transverse tensile stress at break 190 N/mm 2 Yellowness Index (YI) 49
Example 2
[0145] Coextrusion technology is used to produce a multilayer PET film of thickness 17 μm with the layer sequence A-B-A, B being the core layer and A being the outer layers. The thickness of the core layer is 15 μm and that of each of the two outer layers which cover the core layer is 1 μm.
[0146] The polyethylene terephthalate used for the core layer B is identical with that of example 1 except that it comprises no UV absorber.
[0147] The core layer moreover comprises 2% by weight of flame retardant, the flame retardant being fed in the form of a masterbatch. The masterbatch is composed of 10% by weight of flame retardant and 90% by weight of PET.
[0148] The PET of the outer layers has a standard viscosity SV (DCA) of 810 and has been provided with 1% by weight of Tinuvin 1577 and 0.3% by weight of Sylobloc. The outer layers comprise no titanium dioxide and no flame retardant.
[0149] For the core layer, 50% by weight of polyethylene terephthalate, 30% by weight of recycled polyethylene terephthalate material, and 20% by weight of the masterbatch are precrystallized, predried, and post-dried as in example 1.
[0150] The outer layer polymer does not undergo any particular drying. Coextrusion technology is used to produce a film of thickness 17 μm with the layer sequence A-B-A and with the following properties:
Layer structure A-B-A Total thickness 17 μm Surface gloss side 1 131 (Measurement angle 20°) side 2 126 Light transmittance 49% Surface defects none (specks, orange peel, bubbles, . . . ) Longitudinal modulus of elasticity 3 550 N/mm 2 Transverse modulus of elasticity 4 130 N/mm 2 Longitudinal tensile stress at break 120 N/mm 2 Transverse tensile stress at break 155 N/mm 2 Yellowness Index (YI) 13.3 Coloration uniform
[0151] After 200 hours of heat-conditioning at 100° C. in a circulating-air drying cabinet the mechanical properties are unaltered. The film exhibits no embrittlement phenomena of any kind.
[0152] The film fulfills the requirements of construction materials class B2 and B1 to DIN 4102 Part 2 and Part 1. The film passes the UL 94 test.
[0153] After in each case 1000 hours of weathering per side with the Atlas CI 65 Weather Ometer the PET film has the following properties:
Layer structure A-B-A Total thickness 17 μm Surface gloss side 1 125 (Measurement angle 20°) side 2 116 Light transmittance 45% Surface defects none (specks, orange peel, bubbles, . . . ) Longitudinal modulus of elasticity 3 460 N/mm 2 Transverse modulus of elasticity 4 050 N/mm 2 Longitudinal tensile stress at break 110 N/mm 2 Transverse tensile stress at break 145 N/mm 2 Yellowness Index (YI) 15.1 Coloration uniform
Example 3
[0154] A 20 μm A-B-A film is produced as in example 2, the thickness of the core layer B being 16 μm and that of each of the outer layers A being 2 μm.
[0155] The core layer B comprises only 5% by weight of the flame retardant masterbatch of example 2.
[0156] The outer layers are identical with those of example 2, except that they comprise 20% by weight of the flame retardant masterbatch used in example 2 only for the core layer.
[0157] The raw materials and the masterbatch for the core layer and the outer layers are precrystallized, predried, and postdried as in example 1.
[0158] The multilayer 20 μm film produced by means of coextrusion technology has the following property profile:
Layer structure A-B-A Total thickness 20 μm Surface gloss side 1 136 (Measurement angle 20°) side 2 128 Light transmittance 41% Surface defects none (specks, orange peel, bubbles, . . . ) Longitudinal modulus of elasticity 3 400 N/mm 2 Transverse modulus of elasticity 4 100 N/mm 2 Longitudinal tensile stress at break 120 N/mm 2 Transverse tensile stress at break 160 N/mm 2 Yellowness Index (YI) 13.1
[0159] After 200 hours of heat-conditioning at 100° C. in a circulating-air drying cabinet the mechanical properties are unaltered. The film exhibits no embrittlement phenomena of any kind.
[0160] The film fulfills the requirements of construction materials classes B2 and B1 to DIN 4102 Part 2 and Part 1. The film passes the UL 94 test.
[0161] After in each case 1000 hours of weathering per side with the Atlas CI 65 Weather Ometer the PET film has the following properties:
Layer structure A-B-A Total thickness 20 μm Surface gloss side 1 124 (Measurement angle 20°) side 2 117 Light transmittance 38% Surface defects none (specks, orange peel, bubbles, . . . ) Longitudinal modulus of elasticity 3 350 N/mm 2 Transverse modulus of elasticity 4 000 N/mm 2 Longitudinal tensile stress at break 105 N/mm 2 Transverse tensile stress at break 140 N/mm 2 Yellowness Index (YI) 15.8
[0162] Thermoformability
[0163] The films of examples 1 to 3 can be thermoformed on commercially available thermoforming machinery, e.g. from the company Illig, to give moldings, without predrying. The reproduction of detail in the moldings is excellent, with uniform surface.
Comparative example 1
[0164] Example 2 is repeated. However, the film is not provided with UV absorbers, nor with flame retardant masterbatch. DEG content is the commercially available 0.7%, and no PEG is present.
[0165] The white film produced has the following property profile:
Layer structure A-B-A Total thickness 17 μm Surface gloss side 1 139 (Measurement angle 20°) side 2 130 Light transmittance 50% Surface defects none (specks, orange peel, bubbles, . . . ) Longitudinal modulus of elasticity 4 250 N/mm 2 Transverse modulus of elasticity 4 700 N/mm 2 Longitudinal tensile stress at break 180 N/mm 2 Transverse tensile stress at break 215 N/mm 2 Yellowness Index (YI) 12.0 Coloration uniform
[0166] The unmodified film does not fulfill the requirements of the tests to DIN 4102 Part 1 and Part 2, or of the UL 94 test.
[0167] The film has inadequate thermoformability.
[0168] After 1000 hours of weathering per side using the Atlas CI Weather Ometer the film exhibits embrittlement phenomena and cracking on the surfaces. This makes it impossible to measure the property profile precisely—in particular the mechanical properties. Furthermore, the film has visible yellow coloration. | The invention relates to a white, flame-resistant, UV-stable, thermoformable, oriented film made from a crystallisable thermoplastic, the thickness of which lies in the range of from 10 μm to 350 μm. Said film comprises at least one white pigment, a flame-proofing agent and a UV absorber and is characterized by good stretchability and thermoformability, by good optical and mechanical properties and an economical production. The invention further relates to a method for the production of said film and the use thereof. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims benefit of priority of U.S. Provisional Application Ser. No. 61/949,736 titled, “PORTABLE HOT BEVERAGE MAKER OR TUMBLER WITH PASSIVE COOLING SYSTEM,” filed on Mar. 7, 2014, the content of which is incorporated by reference herein in its entirety.
FIELD
[0002] The present invention relates generally to a travel mug, and more particularly to a travel mug with a built-in brewing apparatus and/or cooling mechanism.
SUMMARY OF THE INVENTION
[0003] In embodiments of the invention, a travel mug is disclosed comprising an outer sidewall portion defining a container for holding a liquid and a brewing cup formed at the base of the container. A valve may be positioned within the container so as to divide the container into a water tank and a brewing receptacle, and a valve may be attached to the valve button via a valve rod. A beverage channel may be provided for communicating fluid from the brewing receptacle to the exterior of the device, and a passive cooling mechanism may be integrated adjacent a portion of the beverage channel. In alternate embodiments, a passive cooling mechanism may be integrated into the base of the device, near the brewing receptacle.
[0004] In embodiments, the passive cooling mechanism may further include a ventilation channel. In further embodiments, the beverage channel may be configured to increase the surface area for heat transfer, and may be positioned adjacent at least one compartment containing a phase change material. In further embodiments, the beverage channel or phase change material compartment is exposed to an outer sidewall. In embodiments, a dosing valve may dispense a set quantity of liquid into the brewing cup. A heating element may also be provided, and may be powered by any of an internal battery, an AC power source, or a DC power source.
[0005] In alternative embodiments, the brewing cup may be omitted and the invention comprises an outer sidewall portion defining a container for holding a liquid, a beverage channel for communicating fluid to the exterior of the device, and a passive cooling mechanism adjacent a portion of the beverage channel.
BACKGROUND
[0006] Travel mugs of the prior art come in a variety of styles and configurations, but most, if not all, are designed to retard the natural cooling of the liquid so that the user may enjoy a hot beverage longer than would otherwise be possible. Existing mugs use various materials, lids, vacuum chambers, and the like to maintain the temperature.
[0007] Because of the potentially elevated temperatures of the liquids held in mugs of the prior art, a user must generally wait for the beverage to cool before consuming, or risk injury.
[0008] Devices in the prior art have attempted to address this problem through various means. For example, some other devices cool hot beverages within cup or mug by separating a portion of the drink in the lid. However, these devices are lacking in several respects. First, they may not be effective enough to cool beverages from the highest possible temperature (212° F.) to the temperature range widely regarded as truly safe (136° F.). Second, they may fail even to cool beverages to the devices' maximum capacity from the very first sip, but may become more effective only with subsequent sips. Third, they are inconvenient to use, requiring the user to tip the cup more and more with each successive sip.
[0009] Alternative methods employ phase change material (PCM) encased in metal capsules that cool hot beverages when immersed in liquid. However, these devices require a wait (5 minutes, per instructions) for the product to absorb the beverage's heat, and cool the entire contents of the cup or mug into which they are inserted at the same time, meaning the consumer must rush to finish drinking quickly once the beverage has reached target temperature. These capsules also take up space inside the mug and significantly reduce the volume of beverage itself that the mug can carry.
[0010] Accordingly, what is needed is a thermal beverage container that rapidly cools the liquid as the user drinks from the container, without significant initial waiting or significant waiting between subsequent sips.
[0011] What is further needed is a thermal beverage container that cools the liquid to a safe drinking temperature from the initial sip.
[0012] What is further needed is a thermal beverage container that cools the liquid without requiring progressively more uncomfortable tipping to cool the liquid, and permits consumption using a straw.
[0013] What is further needed is a thermal beverage container that cools only the amount of beverage being consumed at the moment, and leaves the remainder hot, so the user can finish the contents of his tumbler at satisfying temperature at his leisure.
[0014] What is still further needed is a thermal beverage container that brews and cools South American mate or tea in the Chinese gongfu style. The mate and gongfu practices require brewing a small quantity of beverage at a time (e.g., 1-2 oz.), drinking it, and then repeating multiple times, until a full beverage serving is consumed. Since the ideal brewing temperature of mate and tea is higher than the safe drinking temperature, what is needed is a thermal beverage container that cools beverage in discrete portions, immediately after each portion is brewed, while leaving the unused water for brewing still hot.
[0015] Lastly, what is needed is a thermal beverage container that is volumetrically efficient and substantially maximizes the amount of volume available for liquid within the device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The features and advantages of the disclosure will be more fully understood with reference to the following description of exemplary embodiments of the invention when taken in conjunction with the accompanying figures, which are a graphical representation of the salient elements of the present invention.
[0017] FIG. 1 is a perspective view of a travel mug according to an embodiment of the present invention.
[0018] FIG. 2 is a front view of a travel mug according to an embodiment of the present invention.
[0019] FIG. 3 is a cutaway side view of a travel mug according to an embodiment of the present invention.
[0020] FIGS. 4-6 show an alternative embodiment as illustrated with a modified cooling system.
[0021] FIG. 7 shows a further alternative embodiment with a modified cooling system.
[0022] FIGS. 8-10 show a further alternative embodiment with a modified cooling system.
[0023] FIG. 11 is a cutaway perspective view of a further modified embodiment with an alternative cooling system.
DESCRIPTION
[0024] In embodiments, a portable, spill-proof travel mug is disclosed that enables a user to enjoy his favorite hot beverage at a safe and comfortable drinking temperature. In certain embodiments of the invention, a travel mug is disclosed that permits the user to fill the unit with a hot beverage already made. In alternative embodiments of the invention, a hot beverage may be brewed in the unit, with hot water in one compartment and brewing ingredients (e.g., tea leaves or ground coffee) in another so that later, the user can brew a beverage on the spot and at the moment of consumption for freshest flavor.
[0025] FIG. 1 shows an exterior view of an embodiment of the invention, while FIG. 2 shows the exterior front view of this embodiment. In embodiments, travel mug may be generally cylindrical in shape, and of about the same height and diameter as a typical 1-liter thermos bottle. It will be appreciated by those of skill in the art that the device of the present invention may take on various sizes and configurations that depend on the needs of the individual user. The views in FIGS. 1 and 2 show the device with a mouthpiece in the closed position for leak-proof transport when the device is not in use.
[0026] Referring to FIG. 3 , a vertical cross section of an embodiment of the present invention is disclosed. In embodiments, a water tank 1 and a detachable brewing cup 5 may be separated by a dosing valve 2 . Dosing valve 2 may be actuated by a valve rod 4 , which in turn may be actuated by downward pressure on valve button 3 . Valve button 3 may be covered by a flexible membrane that keeps the device watertight and spill-free. Valve button 3 and mouthpiece 9 are part of cap assembly 10 , which can be detached as a single piece when the user wishes to fill water tank 1 with water.
[0027] In embodiments, dosing valve 2 is in a normally open position with regard to water tank 1 , and in a normally closed position with regard to brewing cup 5 below it. When actuated, dosing valve 2 may release a quantity of water necessary for a single beverage portion—approximately 1.5 oz.—and then close again. The amount of water released by dosing valve 2 is determined by the volumetric capacity of the reservoir within the valve.
[0028] To prepare the device for use, the user may first detach cap assembly 10 from the main body portion and fill water tank 1 with hot water for brewing. User may then detach brewing cup 5 from the main body and fill the cup with tea leaves or other brewing material. Detachable filter tube 12 may then be inserted into the leaves and anchored to the edge of brewing cup 5 . Then the brewing cup is reattached to the main body, with index marks on the pieces aligned so as to connect filter tube 12 and beverage tube 6 . The device is now ready for use, and can be tossed into handbag, briefcase or backpack for use later “on the go.”
[0029] When ready to brew and drink, the user unfolds mouthpiece 9 and pushes valve button 3 to transfer 1.5 oz. of hot water into brewing cup 5 . There, the water infuses the tea leaves for the steeping time the user prefers. The user can then draw on mouthpiece 9 to draw the freshly brewed, still-hot tea beverage up through filter tube 12 into beverage tube 6 and the passive cooling system, where it is cooled to 136 F. As the user continues to draw, the cooled beverage passes through the mouthpiece and into his mouth.
[0030] When ready, the user repeats the process by pushing valve button 3 to release another dose of water to infuse the tea leaves in brewing cup 5 again. The process can continue until all of the water in water tank 1 has been used, or until the flavor of the tea leaves in brewing cup 5 has been exhausted. This capacity to steep leaves repeatedly in small quantities of about 1-2 oz. to produce a gradually evolving flavor experience is highly valued in the South American mate and Chinese gongfu tea traditions.
[0031] In a preferred embodiment, the cooling system of the present invention may include: (1) heat-absorbing phase change material (PCM) contained within a compartment in contact with the beverage tube, and (2) a space, void or channel allowing the ambient air around the device to flow across both the inward and outward surfaces of the PCM compartment and/or beverage tube to facilitate quickest cooling.
[0032] FIGS. 1-3 show beverage tube 6 as a simple tube, and imply that the compartment containing the PCM 7 is tubular also and wrapped around the beverage tube, and also that ventilation space 8 for heat transfer between PCM and ambient air is cylindrical or ovoid. However, the exact shapes, dimensions and configurations of the elements encompassed by this invention are infinitely variable, and could include without limitation such devices to facilitate heat transfer as convoluted fin stock, inline static mixers, dimples, fins, pins, etc. The cooling system could be open to the ambient air directly, or through a porous grill, or through discrete ports or slots, among many possibilities. In some embodiments, slides, louvers, or other mechanisms may enable the user to partially or totally open or close these ventilation orifices in order to adjust the final temperature of the beverage, or to compensate for extreme ambient conditions.
[0033] Final beverage temperature may also be controlled by a mechanism permitting selection between alternative PCM compartments containing different PCMs with different thermal characteristics, or by employing multiple PCM varieties in tandem. Also, the system may include no PCM at all, and may rely on the cooling effect of the ambient environment on the exposed beverage tube alone. The system may also provide no interior ventilation space, and may rely on cooling from exposure of only the outward surfaces of the PCM compartment and/or beverage tube.
[0034] In embodiments, the cooling system will allow a user to draw 1.5 oz. of beverage through beverage tube 6 and out of mouthpiece 9 without pause, and will cool the beverage to 136 F. instantly as it passes through. In less efficient configurations, the hot beverage may need to be exposed to PCM compartment 7 and ventilation space 8 longer in order to cool all of the way to target temperature. Those configurations may deploy a one-way check valve 11 to hold hot tea in place in beverage tube 6 for the few seconds that may be needed for complete cooling.
[0035] To keep to a compact size, preferred embodiments will deploy only enough PCM to absorb the heat of a single 1.5-oz. dose of tea being cooled from 212 F. to 136 F. (approximately 1 oz. of PCM). After cooling one dose of tea, the PCM (now melted) will itself need time to cool and re-solidify before cooling the next dose. This PCM recovery takes place while the consumer is savoring the flavor of the tea he has just brewed. For most tea drinkers, and especially those who admire the gongfu style, appreciative drinking with pauses between sips is desirable.
[0036] Alternative embodiments may deploy enough PCM to cool the entire contents of the device without recovery pauses.
[0037] It should be noted that while various embodiments discuss specific beverage types, the present invention is not limited to tea, coffee or mate, or indeed beverages that are brewed. The embodiments of the present invention can conceivably be utilized with any hot beverage for consumption.
[0038] Referring to FIGS. 4-6 , an alternative embodiment is illustrated in which the cooling efficiency of the system may be enhanced by modifying the beverage tube. In embodiments, beverage tube 6 is deformed (e.g., flattened or stretched) into a planar beverage channel 6 , to maximize the area for heat transfer between it and the PCM compartments 7 sandwiching it. The planar cooling sandwich ( 6 , 7 ) may be wrapped around the exterior of the device, and the ventilation space 8 , accordingly, may also be planar in form and wrap around the device to cool the interior side of the cooling unit.
[0039] Referring to FIG. 7 , beverage channel 6 may have a zig-zag or labyrinthine beverage track that can direct the beverage back and forth across the entire heat-transfer surface, as the beverage travels from the bottom of the cooling unit to the top. The beverage track may be either carved into one of the beverage channel walls, or formed by dividers projecting from one of the walls.
[0040] Referring to FIGS. 8-10 , a further alternative embodiment is described in which the planar sandwich of FIGS. 4-6 has been simplified to a single outer PCM compartment 7 and beverage channel 6 . In this embodiment, beverage channel 6 may be defined by the inner wall of PCM compartment 7 on one side, and the outer wall of ventilation channel 8 on the other side. In some variations of this embodiment, a tank assembly consisting of water tank 1 , valve rod 4 and dosing valve 2 may be detachable from the device's outer shell in order to facilitate cleaning of tank and valve. Such an arrangement would also separate the walls forming beverage channel 6 , and expose the entirety of the beverage channel's inner surfaces for easy cleaning.
[0041] In further embodiments, PCM compartment 7 may be easily detachable from the device's main body for the same benefits of easy cleaning of beverage channel 6 . FIGS. 8-10 illustrate an embodiment in which PCM compartment 7 , beverage channel 6 , and ventilation channel 8 only wrap partly around the exterior, rather than completely around. Referring to FIG. 10 , inlet slots 14 and outlet slots 15 are shown as leading to and from interior ventilation space 8 .
[0042] Other embodiments of the invention, like that shown in FIG. 11 , may cool each portion of beverage after brewing in a connected cooling chamber 16 , which may either be directly exposed to the ambient air, or provided with a PCM compartment 17 which in turn might be exposed to ambient air.
[0043] The range of possible shapes, sizes and configurations of the cooling chamber is as broad and limitless as the variations described previously for beverage tube 6 and PCM compartment 7 , and includes, but is not limited to, lattice-work channels, parallel planar fins, and the simple cup shape depicted. A user-actuated valve between brewing cup 5 and cooling chamber 16 may be deployed. After each dose of tea has been cooled in cooling chamber 16 , the user can sip it out through the simple filter and beverage tube as with any simple straw.
[0044] Where the capacity for internal, multi-steep brewing is not required, some embodiments of this invention will work as a unique cooling travel mug for hot beverages that have already been made. Quite simply, a consumer could take any one of the embodiments depicted in FIGS. 1-10 , omit adding tea leaves to brewing cup 5 , fill water tank 1 with ready-made hot tea, coffee or cocoa, and then cool and drink the beverage. Other embodiments strictly dedicated to non-brewing travel-mug service, and based on the cooling model illustrated in FIG. 11 , could simply eliminate brewing cup 5 from the design and deploy cooling chamber 16 with PCM compartment 17 directly below the beverage tank and dosing valve.
[0045] In alternative embodiments, an electrical heating element may be incorporated to heat water to brewing temperature. In embodiments, the PCB and other components may be located in a watertight band around the underside of the top of the device. A heating element attached to the underside of the top of the device could project downward into water tank 1 . In an embodiment, the heating element may be structured and positioned so as to operate both as heating element and valve rod 4 .
[0046] In embodiments, a heating element may be powered by connection to a car cigarette lighter socket, wall outlet, or internal battery.
[0047] Buttons or other mechanisms for selecting the desired water temperature could also be deployed on the exterior of the device. In a preferred embodiment, all electrical components may be located on a single part (e.g., the device top), leaving all other parts of the electrical and non-electrical versions of the device interchangeable. Such a configuration may increase efficiency and reduce manufacturing cost.
[0048] Other electronic components may be incorporated. For example, an LED display on the exterior of the device could signal water temperature and system status. Wireless connectivity such as Wi-Fi or Bluetooth cold similarly be incorporated to provide information to a remote device such as a smartphone or a dash-mounted display in a vehicle.
[0049] While all embodiments illustrated and described here have involved a mouthpiece as the final delivery system, this invention encompasses embodiments with beverage channels that terminate in standard drinking holes in the cap, or other commonly known means.
[0050] It will be understood that any of the elements and/or exemplary embodiments of the disclosure described can be rearranged, separated, and/or combined without deviating from the scope of the disclosure. For ease, various elements are described, at times, separately. This is merely for ease and is in no way meant to be a limitation.
[0051] While the various steps, elements, and/or exemplary embodiments of the disclosure have been outlined above, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. The various steps, elements, and/or exemplary embodiments of the disclosure, as set forth above, are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the disclosure. Accordingly, the spirit and scope of the present disclosure is to be construed broadly and not limited by the foregoing specification. | A travel mug that maintains its liquid contents at temperature while cooling portions of the beverage on demand to a safe and comfortable drinking temperature. In embodiments, a passive cooling system is integrated into the travel mug for drawing heat from the beverage as the user consumes it. In embodiments, a brewing system may be integrated to brew beverage matter into a drinkable beverage. In embodiments, a heating element may be provided to raise water to brewing temperature or to further heat the liquid in the container. | 0 |
BACKGROUND OF THE INVENTION
The plants for the manufacture of integrated circuits have become very expensive. A modern wafer fabrication plant can cost in excess of $500 million. At the same time, there is a demand for inexpensive, complex integrated circuits. A critical factor in meeting this demand is the yield of good integrated circuits, i.e. the percentage of the integrated circuits that are fabricated that meet specifications published for the particular type of integrated circuit (IC). The current practice is for engineers to manually analyze failing circuits to ascertain the causes of the failing ICs.
These causes may be generally grouped under three headings: design errors; misprocessing which causes the parameters of basic circuit elements, such as resistors, capacitors, and transistors, to deviate from their design values; and random, localized process defects which cause individual ICs to fail. Examples of the localized process defects are (1) gate oxide defects which cause a transistor gate to short to the under lying substrate and (2) unopened contact vias which cause two nodes to fail to be connected. Design errors are usually identified early in the product life and once corrected are no longer of concern. Parametric failures are relatively easily monitored and detected by means of test patterns inserted onto the semiconductor wafer for this purpose.
Localized defects are much harder to identify. First the circuit fault that caused the failure must be located. Then the fabrication defect that caused the fault must be identified. Since localized defects arise from point contaminants or inhomogeneities in the processing environment and processing materials, they are always present to a certain extent. The goals of the yield improvement team are to identify which defects are most important in limiting yield and then to take appropriate action to reduce the occurrence of those defects.
The current practice is for an engineer to manually analyze failing units in order to identify the failure causes. This process is tedious and slow. For example, an engineer may only be able to analyze ten units per day. Unless one defect mechanism is overwhelming predominant, this is a statistically small sample. As a result, decisions made based on such a small sample may not attack the most important problems. Moreover, engineering analysis is usually only available on one shift, whereas the fabrication plants operate around the clock, seven days a week, in order to make maximum use of the huge capital investment. The consequence of this is that corrective action is delayed while waiting for the failures to be analyzed.
Computer technology has advanced to the point that the problem of analyzing failures arising from local faults to find the underlying defects has become practicable.
SUMMARY OF THE INVENTION
According to the invention, a system for the automatic identification of fabrication defects that lead to the failure of integrated circuit products is disclosed. This invention is composed of two parts, a knowledge generation part and a knowledge application part. In the knowledge generation portion of this system, design information of the product to be tested is analyzed to identify electrical node-to-node faults that can be caused by fabrication defects. The circuit is then analyzed to determine the electrical response to input patterns which result from the node-to-node faults. A matrix which relates failure responses to a multiplicity of input patterns as a function of process defects is constructed. This response matrix is used later to identify the fabrication defect. In those cases in which the response matrix is degenerate, i.e. a set of output responses can arise from more than one fault, knowledge about the probability of occurrence of various defects is used to assign probabilities to the node-to-node faults which may generate the output response set. The knowledge application portion of the system makes use of the response matrix to analyze specific integrated circuits. This portion of the system takes knowledge of a specific IC test system and the response matrix to generate a set of test vectors which will be used to analyze a product. Having generated the appropriate set of test vectors, the system is able to instruct the IC test system to apply these vectors to the device under test (DUT). The response of the DUT to the test vectors is used to identify the fabrication fault which caused this device to fail. The system is capable of repeating the test and analysis sequence rapidly on a number of parts and using the results of testing many units to generate statistical measures which can be employed by engineers to improve the manufacturing process in order to decrease the percentage of defective units.
A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the specification and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating the knowledge generation portion of the invention.
FIG. 2 is a block diagram indicating the flow of information in the defect identification section.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention described here is particularly suited to ICs for which the failures are dominated by faults in a small number of distinct cells which are repeated to form large arrays. The reason that this invention is particularly suited for such arrays is the computational power needed for the analysis described herein. However, as computers become more powerful, the range of circuits to which this invention can be reasonably applied will expand. Memories are the archetype of large arrays although large programmable logic devices (PLDs) and field programmable gate arrays (FPGAs) also may fit this description. Regular arrays which are part of a larger circuit may also be used as a diagnostic tool for the complete circuit if they contain technology features similar to the arrays described above. An example might be a cache RAM on a microprocessor chip. For the sake of concreteness, a system for the analysis of memories is described with the understanding that other types of ICs may also be suitable for analysis with the system described here.
In the description which follows the word "defect" will be taken to mean a physical flaw resulting from the manufacturing process, such as a pinhole through a gate oxide, or a hole in a metal line. The word "fault" will be taken to be the electrical alteration in the circuit topology resulting from the "defect" such as the gate and the substrate being shorted together. The word "failure" will be taken to mean an errant response of the IC to a stimuli or an IC that provides one or more erroneous output responses.
The invention is most easily understood by reference to FIG. 1, which illustrates the knowledge generation portion of the invention. A number of data files are needed as the basic inputs to the system. These are included in box 11 in FIG. 1. Among the required files are the process/layer file, the data base which describes the topology of each layer, the circuit schematics for the cells which interface directly to the repeated cells, the layout-versus-schematic (LVS) file, the device architecture description, and a defect matrix file.
The process/layer file describes the order in which the various layers are formed and whether a layer is conducting or insulating. It also indicates if a transistor is formed by a combination of layers. There are several formats in which the process/layer file could be presented to the system. If the user has already created such a file for use by a commercial design tool, such as Dracula® (a registered trademark of Cadence Design), this format should be accepted to avoid repetitive effort. If the user has not created such a file, then a graphical user interface (GUI) is provided to create the file.
GDS II is an industry standard in which design data bases are sent to mask shops to make the photo masks used to define the layers. This system accepts GDS II formatted topology descriptions because this is the common format in which all circuits are available.
The schematics are needed for the circuits which interface directly to the repeated cells so that the analog electrical behavior of the repeated cells can be accurately simulated as will be described in more detail later.
The defect matrix defines the probability of both interlayer and intralayer defects as a function of defect size. This matrix is needed to calculate probabilities of faults later, so there must be a default matrix supplied by the system which is used if the user cannot or does not choose to supply the matrix for his specific process.
Information from the layer topology data base, the interface cell schematics, the layout-versus-schematic file, and the device architecture are combined to form the information needed for automatic fault extraction 12 (AFE). The input to the AFE is the names of the basic repeated cells to be analyzed, the number of memory bits in the basic cells, and the number of times these cells are repeated in the array. The AFE controller selects the basic cells one at a time and calls the automatic fault extraction 12 to analyze these cells.
At the heart of the AFE is a technique called inductive fault analysis, IFA. IFA is a recently developed technique which examines a layout topology and assigns probabilities to faults between the electrical nodes in the circuit. For example, the probability of a fault which shorted two adjacent metal lines would be proportional to the distance over which the lines were adjacent, inversely proportional to the spacing between the lines and proportional to the density of bridging defect at least as large as the line spacing. This technique is described in the "Systematic Characterization of Physical Defects for Fault Analysis of MOS IC Cells," by Maly, Ferguson, and Shen, herein incorporated by reference. Inductive fault analysis is also described in "A CMOS Fault Extractor for Inductive Fault Analysis," by Ferguson and Shen, herein incorporated by reference. The result of this analysis is a list connecting layout defects to schematic faults 113.
The net lists 13 generated by the automatic fault extractor 12 are not in a form that is directly usable by a circuit simulation program to find the response of the array to any single fault. The circuit simulation controller 14 prepares a set of schematic net lists which are suitable for this use. These net lists are combined with more information needed for further analysis. The additional information needed includes the dynamic circuit description, the device model parameters for the circuit elements, and a description of any special test modes which are available on the IC under examination.
The dynamic circuit description is composed of two portions. One portion is simply the data sheet description which gives the specified output for various input stimuli. The other portion is the internal timings for the lines which drive those circuits which interface directly to the array. Examples of the lines which interface directly to the array are the row decoder, the column bias and multiplexing circuitry, and the sense amplifier. Examples of the internal timing signals required for the case of a dynamic RAM are the precharge, equalization, and sense strobe signals to the sense amplifier.
The device parameters are needed for the analog circuit simulation which will be described shortly. An example of a parameter which is typically used in the circuit simulation is electron mobility and its dependence upon temperature, lateral electric field, and vertical electric field.
Many integrated circuits have special test modes which may not be described on the data sheet, but which allow special access to the array. An example is that some EPROMs have a special mode which allows the word line voltage to be varied independently from the rest of the circuit. Because these special modes may provide information which is key to identifying a fault, it is critical to know of any special modes which exist.
The circuit simulation controller 14 then takes each basic schematic and creates a number of derivative schematics, one for each fault. The electrical response of each of these schematics is simulated for each possible condition (e.g. read, write, and special test modes) and for a number of combination of signals (e.g., write a checkerboard pattern, or march a "1" through a background of "0"s). There are a number of analog circuit simulators which could be used for the simulation 15. The best known is SPICE, which was developed by the University of California at Berkeley and is available commercially from several companies. Fortunately, because of the array symmetries, the number of useful combinations of signals is rather small, usually less than twenty.
Because the defects may be of several different sizes, it may be necessary to simulate for several different values of resistances or transistors in some faults. For example, gate oxide defects that result in a "gate-to substrate short" might be best represented by resistors between gate and substrate of differing sizes depending upon the size of the defect.
The result of all of this simulation is the electrical response of the circuit containing various faults 16. The response post processing, 17, can construct a classification connecting electrical failures (response patterns to stimuli) matrix connecting electrical failures (response patterns to stimuli) to faults. Finding the irreducible representation of this matrix will put it in semi-diagonal form with all of the faults that create unique response patterns on the diagonal and those faults that share response patterns in square sub-matrices on the diagonal. At this point any redundant tests are removed (i.e. those which engender the same response for all faults) and the non-unique faults (i.e. those that have the same electrical response to all patterns) are summed. The result of all of this is a pattern response vs. defect matrix.
The program described above is obviously computationally intensive. However, it need only be performed once for each IC design. Once the classification matrix is derived it can be used to analyze as many units as is desired without recalculating the matrix. Fortunately, work station class computers have been developed which can do the calculations necessary to define the classification matrix in a reasonable time.
Once the classification matrix is calculated, the system is ready for defect identification. Shown in FIG. 2 is a block diagram of the defect identification portion 30 of the invention. The additional information required beyond that used by the portion of the system illustrated by FIG. 1 is that information which is specific to the tester to be used for the defect detection testing. This includes the tester capabilities and the test description language and is shown as item 31. A set of test vectors is supplied with the detection system which are specific to the type of memory to be tested. There is also the ability to create custom tests to handle device specific items such as the special test modes mentioned earlier. The generation of test patterns is discussed in "Test Pattern Generation for Realistic Bridge Faults in CMOS ICs," by Ferguson and Larrabee, herein incorporated by reference.
The fault detection controller 33 combines information from the output of the defect identification matrix 18 with information from the circuit simulation controller 14 to select the test vectors to use to detect the faults and to classify the failure modes. It instructs the automatic test equipment 35 to execute the test vectors and records the responses. From the responses, a bit map of the failing bits is generated. This map is used to classify the device under test 37 (DUT) by mode (e.g. good, column failure, row failure, single bit failure, etc.).
The output bit map and mode classification is passed to the defect identification controller 34. This controller runs the tests necessary to generate the inputs to the pattern response vs. defect matrix. There are two possible approaches to selecting the tests to be run. An expert system can be used which will minimize the number of tests needed to make a unique identification. The other approach is to run all of the tests used in the defect identification matrix 18. The advantage of the expert system approach is that it minimizes test time. The disadvantage is that the expert system must be trained which takes engineering time to set it up. The advantage of the exhaustive approach is that it requires no set up time. If the address space has been reduced sufficiently in the mode classification, the tests that the defect identification controller 34 needs may run so fast that there is no practical gain to the expert system. For some device types (e.g. EEPROMs), the ID tests may run slowly enough to make an expert system worth while. Both approaches can be supplied with the user being able to select the better. For example, one approach would be to use exhaustion as a first choice and add the complication of the expert system only if exhaustion proved to be too slow.
The defect identification controller 34 provides the identification of the defect or possible defects and the bit map location of the defect. Post processing 36 is done on this information to refine the solution found. For example, the test result might say that a particular failure is a result of either a gate to bit line diffusion short or a metal bit line to poly gate short. However, if it is known that the poly gate over bit line diffusion edge is twice as long as the metal to poly edge and that the probability of a gate oxide defect is ten times that of an interlevel dielectric defect, the conclusion could be drawn that the probability is 95% that the failure results from agate oxide defect and 5% that it results from an interlayer dielectric defect. Such probabilities are especially useful when the defect distributions are computed for a number of units.
Another bit of post processing done at this juncture is to give the absolute location of the defect on a die. This is useful if someone wants to use a computer controlled prober or focused ion beam (FIB) system to physically verify the reported diagnosis.
The results of the analysis are stored in a data base for further processing. After a number of units have been analyzed, for example by testing all of the failing units on several wafers, statistical reports 39 can be prepared giving useful information such as defects in ranked order of occurrence, defects causing single bit failures in ranked order of occurrence, failure modes in ranked order of occurrence, and a wafer map showing the frequency of the failures by wafer location. This processing is the function of the report generator 38. The information in the data base can be linked to other engineering data bases for further analysis.
While the invention has been particularly shown and described with reference to specific embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in the form and details may be made therein without departing from the spirit or scope of the invention. | An automated system for identification of fabrication defects that lead to the failure of IC products. Design information of the product to be tested is analyzed to identify electrical node-to-node faults that can be caused by fabrication defects. The circuit is then analyzed to determine the electrical response to input patterns which result from the node-to-node faults. A matrix which relates failure responses to a multiplicity of input patterns as a function of process defects is constructed. This response matrix is used to identify the fabrication defect. In those cases in which the response matrix is degenerate, i.e. a set of output responses can arise from more than one fault, knowledge about the probability of occurrence of various defects is used to assign probabilities to the node-to-node faults which may generate the output response set. The system then takes knowledge of a specific IC test system and the response matrix to generate a set of test vectors to analyze a product. The system instructs the IC test system to apply these vectors to the device under test (DUT). The response of the DUT to the test vectors is used to identify the fabrication defect which caused the device to fail. Test results for a number of devices may be used to generate statistical measures which can be employed to improve the manufacturing process, thereby increasing yield. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to an axial thrust balancing system suitable for use with a multi-stage centrifugal pump, multi-stage centrifugal compressor, etc.
One type of axial thrust balancing system known in the art comprises a sleeve mounted on a rotary shaft for balancing axial thrust, a bush separated from the sleeve by a small annular clearance, a high pressure balance chamber interposed between the sleeve and the back of an impeller, and a low pressure balance chamber located on a side of the sleeve opposite the side on which an impeller is located.
In this construction, the majority of the fluid drawn by suction through a suction port of the impeller and discharged from the impeller through a discharge port is supplied through an outlet casing to a predetermined position. Part of the discharge fluid flows into the high pressure balancing chamber located behind the impeller and through the clearance and the low pressure balance chamber to be led to the suction side of a pump or released to the atmosphere.
In the aforesaid axial thrust balancing system, the discharge pressure and the suction pressure of the pump act, for example, on side walls of the sleeve adjacent the high pressure balance chamber and low pressure balance chamber, so that the axial thrust acting in the direction of the suction port of the impeller can be mitigated by the sleeve.
In the aforesaid construction, a fluid filled in the clearance in the form of a thin film performs a sort of bearing function like a film of lubricant formed on a journal bearing. When the rotary shaft is rotated at an angular velocity which is higher than the natural angular frequency of the shafting, self-excited vibration of the shaft may occur as similar to the oil whip of the lubricated-journal bearing.
SUMMARY OF THE INVENTION
This invention has been developed for the purpose of obviating the problem of the prior art described hereinabove. Accordingly the invention has as its object the provision of an axial thrust balancing system capable of stabilizing the bearing characteristics of a film of fluid formed in the clearance between the sleeve and the bush to thereby prevent the occurrence of self-excited vibration of the shaft up to a high rotational velocity.
According to the invention, there is provided an axial thrust balancing system comprising a rotary shaft having an impeller mounted thereon, sleeve secured to the rotary shaft on the discharge side of the impeller for idle movement in an axial direction together with the rotary shaft, a bush attached to a casing enclosing the sleeve and juxtaposed against the sleeve, an annular clearance defined between the sleeve and the bush, a high pressure balance chamber and a low pressure balance chamber formed by the formation of the clearance on a side of the sleeve adjacent the impeller and on a side thereof opposite the side on which the impeller is located, respectively, and at least one pressure chamber located in the annular clearance for dividing it axially into a plurality of shorter annular clearances.
Additional and other objects, features and advantages of the invention will become apparent from the description set forth hereinafter when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic sectional view for explaining the principle of the axial thrust balancing system according to the invention;
FIG. 2 is a schematic sectional view taken along the line II--II in FIG. 1;
FIG. 3 is a diagrammatic representation of the whirling characteristic of a shafting;
FIG. 4 is a diagram showing the manner in which flow of the fluid takes place in the pressure chamber in the clearance according to the invention;
FIG. 5 is a schematic view showing the condition of a two-dimensional jet stream corresponding to the condition shown in FIG. 4;
FIG. 6 is a diagrammatic representation of the self-excited vibration generation limits characteristic of a shaft;
FIG. 7 is a sectional view of the essential portions of the axial thrust balancing system according to an embodiment of the invention; and
FIGS. 8 and 9 are sectional views of the essential portions of the axial thrust balancing system according to other embodiments.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1, in order to enable a stable rotation of a shaft, a rotary shaft 1 has a sleeve 2 mounted thereon for balancing axial thrust, with a bush 3 being attached to a casing, and an annular clearance 4 being defined between the sleeve 2 and the bush 3. FIG. 2 shows balancing of forces, in the direction of swirling velocity occurring when the sleeve 2 moves in swirling movement on a circular orbit of a minuscule radius ε at an angular frequency of Ω. The force F 1 is a force tending to increase the radius ε of the swirling movement by the coupled spring coefficient K xy of the fluid film, and the force F 2 is a force tending to decrease the radius ε of the swirling movement by the damping coefficient C xx of the fluid film. The condition of the swirling movement described above being damped with time can be expressed by the following formula:
F.sub.2 >F.sub.1 (1)
F 1 and F 2 can be expressed by the following equations:
F.sub.1 =K.sub.xy ε (2)
F.sub.2 =C.sub.xx εΩ (3)
By substituting the equations (2) and (3) into formula (1), the following formula (4) can be obtained:
C.sub.xx Ω>K.sub.xy (4)
Formula (3) can be transformed by using the rotation angular velocity ω of the shaft 1 into the following formula (5):
ωC.sub.xx /K.sub.xy >ω/Ω (5)
Experiments were conducted on the spring coefficient and the damping coefficient of the film of fluid in the annular clearance 4 between the sleeve 2 and the bush 3 with regard to various combinations of the axial length L of the clearance 4 and the diameter D of the sleeve 2. The results of the experiments show that the left side ωC xx /K xy of formula (5) shows a change as shown in FIG. 3 as the ratio of the axial length to the diameter L/D is varied. In this figure, it will be seen that ωC xx /K xy shows a sudden increase if L/D is decreased, to enable the shaft 1 to rotate stably up to a high rotational velocity.
The diameter D of the sleeve 2 is set at a value necessary for balancing the axial thrust of the pump. Thus, to reduce the value of L/D, it is necessary to decrease the value of L as compared with that of the prior art. However, the fluid leaking through the clearance 4 would increase in flow rate and the pumping efficiency would be reduced if the value of L is merely decreased. This problem is obviated, if a plurality of sleeves of a small length L are provided to keep the flow rate of fluid leaks from increasing.
However, the use of a plurality of sleeves poses another problem with regard to cost. More particularly, the use of a plurality of sleeves together with a plurality of bushes would result in an increase in cost. However, if a pressure chamber of a large area is provided to one of the sleeve and the bush or to both of them in straddling relation, the effects achieved thereby would be the same as the effects achieved by the provision of a plurality of sleeves and bushes of small L/D. It has been ascertained by experiments that the effects achieved are not satisfactory unless the pressure chamber has an axial length which is over thirty-eight times as great as the size or radial width (i.e. size C in FIG. 4) of the clearance 4.
The axial length and the depth necessary for the pressure chamber to effectively divide the clearance 4 by the pressure chamber can be calculated as presently to be described by regarding the flow in the pressure chamber as a two-dimensional jet stream.
FIG. 4 shows a condition of flow of the fluid in a pressure chamber 5 formed on an inner peripheral surface of the bush 3, in which l denotes the axial length of the pressure chamber 5, t the depth thereof and C the size of the annular gap or clearance 4. FIG. 5 shows a condition of a jet stream of two-dimensional shape in which 2C denotes the width of the jet stream at the ejection port, 2B the width of the jet stream in a cross section axially remote from the ejection port by a distance x and u max the maximum velocity of the jet stream in the central portion thereof. A momentum of the fluid flowing through one cross section of the stream should be constant regardless of the distance Z. Thus the following relation holds between the width 2B of the jet stream and the maximum velocity u max :
u.sub.max.sup.2 2B=constant (6)
Meanwhile when the jet stream is two-dimensional, the width 2B increases in proportion to the distance Z, so that a diverging angle 2θ is constant without regard to the distance Z. Thus, the following relationship holds if streams around the ejection port are ignored:
2B=2C+2Z tan θ (7)
When the jet stream is two-dimensional, the diverging angle 2θ is about 12 degrees. The flow of the fluid in the pressure chamber 5 shown in FIG. 4 may be analyzed by regarding the same as an upper half portion of the two-dimensional jet stream shown in FIG. 5, in the same manner as the two-dimensional jet stream has described hereinabove. It will be seen that the relationship of equations (6) and (7) also hold with respect to the flow in the pressure chamber 5. If the maximum velocity u max is v m at an inlet (Z=0) of the pressure chamber 5, the width B of the jet stream, the maximum velocity u max thereof can be expressed by the following equations (Note that the diverging angle θ of the jet stream is about 6 degrees.): ##EQU1##
With regard to the contribution of deceleration of the maximum velocity u max for obtaining effective functioning of the pressure chamber 5, the role of the pressure chamber 5 would be to separate one portion of the clearance on one side from the other portion thereof on the other side so as to keep the portion of the clearance on the upstream side from influencing the portion thereof on the downstream side. Stated differently, the pressure chamber 5 functions in such a manner that a dynamic pressure v m .spsb.2 /2 g of an axial flow at the inlet of the pressure chamber 5 is satisfactorily reduced within the pressure chamber 5 and the peripheral distribution of pressures existing at the inlet of the pressure chamber 5 is eliminated within the pressure chamber 5. The end of reducing the peripheral distribution of pressures existing at the inlet of the pressure chamber 5 can be attained by satisfactorily reducing the dynamic pressure of the axial flow within the pressure chamber 5.
Taking the total pressure differential in an axial direction of the sleeve 2 as a reference, the function of the pressure chamber 5 would be considered satisfactorily performed if the dynamic pressure u 2 max /2 g can be reduced to less than 1% of the total pressure differential within the pressure chamber 5. Generally the dynamic pressure v m .spsb.2 /2 g of an axial flow in the clearance between the sleeve 2 and the bush 3 is about 5% of the total pressure differential. Thus, one has only to decelerate the flow of the fluid in such a manner that the dynamic pressure is reduced to about 1/5 thereof. In other words, the condition of ##EQU2## would have only to be created in the pressure chamber 5. The axial length l of the pressure chamber 5 necessary for this purpose is as follows from equation (9):
l≧38C (10)
The depth t of the pressure chamber 5 is required to be greater than the maximum width of the jet stream therein, so that the depth t is as follows from equation (8):
t≧0.1l (11)
FIG. 6 shows the critical rotational velocity value (ω/Ω) as measured actually, which causes the self-excited vibration of a shaft in the system 4 in which the ratio of the axial length L of the clearance 4 to the diameter of the sleeve 2 is about 1.0 and the clearance 4 is divided by three pressure chambers into four portions. In the figure, it will be seen that if the dimensionless axial length l/C of the pressure chamber is over thirty-eight times as great, the shafting is suddenly stabilized, thereby providing that equation (10) is appropriate.
Referring to FIG. 7, a rotary shaft 1 has an impeller 8 secured thereto which has a sleeve 2 mounted at its back for balancing axial thrust. A bush 3 is located adjacent an outer peripheral surface of the sleeve 2 with annular clearances 4a, 4b and 4c being interposed therebetween. The bush 3 is formed at its inner peripheral surface with a plurality of (two in this embodiment) pressure chambers 5a and 5b. A high pressure balance chamber 6 is located between the sleeve 2 and the back of the impeller 8, and a low pressure balance chamber 7 is located on a side of the sleeve 2 opposite the side thereof adjacent the impeller 8.
Part of the fluid discharged from the impeller 8 is led into the high pressure balance chamber 6 at the back of the impeller 8 and flows through the clearance 4a, pressure chamber 5a, clearance 4b, pressure chamber 5b and clearance 4c into the low pressure balance chamber 7, before being introduced into the suction side of the pump or released to the atmosphere. The pressure chambers 5a and 5b are sufficiently large in volume to render the bearing action of the fluid filled in the clearances 4a-4c equal to the sum of the bearing actions of the clearances 4a-4c. The clearances 4a-4c are constructed such that the ratio L/D is sufficiently low to obtain stability in the rotation of the shaft up to a high rotation angular velocity, as described by referring to FIG. 3.
In the embodiment shown and described hereinabove, the clearance is divided into the three clearances 4a-4c by the two pressure chambers 5a and 5b. It is to be understood, however, that the invention is not limited to this specific number of clearances. In some cases, it is better to divide the clearance 4 into over four clearances and in some cases two clearances are enough, to give a suitable value to the ratio L/D.
In the embodiment described hereinabove, the two pressure chambers 5a and 5b are located on the side of the bush 3. The invention is not limited to this specific arrangement of the pressure chambers 5a and 5b, and the same effects can be achieved by arranging the pressure chambers 5a and 5b on the sleeve 2 side as shown in FIG. 8 and by arranging them in a manner to straddle the sleeve 2 and the bush 3 as shown in FIG. 9.
From the foregoing description, it will be appreciated that in the axial thrust balancing system according to the invention, the clearance between the sleeve and the bush is divided by a pressure chamber or chambers into a plurality of clearances to reduce the value of the ratio of the axial length L of the clearance to the diameter D of the sleeve. This arrangement is conducive to stabilization of the bearing characteristics of a film of fluid in the clearance, so that the pump can be operated stably without giving rise to a self-excited vibration of its shaft up to a high rotation velocity. | An axial thrust balancing system including a sleeve for balancing an axial thrust applied to a rotary shaft and a bush defining therebetween a clearance having arranged therein at least one pressure chamber for dividing the clearance into a plurality of smaller clearances. The axial division of the clearance reduced the ratio of the axial length of the clearance to the diameter of the sleeve and stabilizes the bearing characteristics of a film of fluid in the clearance, thereby inhibiting the generation of a self-excited vibration of the shaft up to a high rotation velocity. | 5 |
BACKGROUND OF THE INVENTION
An ice re-surfacing machine for skating rinks and the like has two basic parts. The first is the main wheeled body driven over the ice, usually on standard rubber tires. The body generally includes motive power, an operator's seat and controls, a collection system and storage bin for ice cuttings, water tanks for the ice-washing and ice-making process, and a hydraulic arms system for carrying and positioning the ice re-surfacing apparatus.
The second part is the apparatus that re-surfaces the ice in a single pass. This structure, which is towed over the ice by the main body, is generally referred to as the “conditioner,” but sometimes is called the “sled”. The conditioner, carried at the back of the main body on hydraulically activated arms, is essentially an open-bottomed steel box that allows the re-surfacing components access to the ice surface when lowered into operating position and pulled across the ice. A runner and side plate on each side, parallel to the direction of travel, supports the conditioner in operation and confines the ice chips collected and water used in re-surfacing.
The majority of imperfections created in the ice surface by ice-skating are limited to one to two millimeters of ice depth. The conditioner holds a large blade, usually steel, that shaves a very thin layer off the ice surface. Generally, the blade is attached to a supporting draw bar, which is mounted to the conditioner frame.
Ice cuttings generated by the shaving blade must be removed from the ice surface as the blade is pulled along. Mounted forward of and parallel to the blade is a screw conveyor, variously known as a “horizontal conveyor” or “horizontal auger” or “horizontal screw.” The horizontal conveyor comprises a cylindrical shaft onto which one or more helical flanges, referred to as “flights,” are wound around and attached, similarly to the thread on a wood screw. The helical flight converts the rotational spin of the shaft into linear motion parallel to the shaft.
In most ice-resurfacing machines, the horizontal conveyor is configured so that flights on the left side move ice shavings from the outside toward the center of the conveyor, and flights on the right side move ice shavings from the outside toward the center as well. In the center of the horizontal conveyor, flat plates mounted parallel to the rotational axis of the shaft, called “paddles”, connect to the left side and right side auger flights. The paddles are part of the “slinger”, which transfers ice shavings to a vertical conveyor. In operation, the blade shaves the ice, creating ice particles that build up in front of the blade and are caught in the flights of the horizontal conveyor. The horizontal conveyor's rotating flights move the ice particles to the center, where the slinger throws them onto the vertical conveyor.
The vertical conveyor is designed to accept the stream of ice cuttings thrown from the slinger of the horizontal conveyor and move them upward for placing into the ice cuttings storage tank in the main body. The vertical conveyor is also a screw type conveyor, similar in design and function to the horizontal conveyor. All of the helical flights are wound around the central shaft in the same direction, imparting a continuous upward movement of ice cuttings from the bottom of the conveyor to the top. At the top, slinger paddles sweep the cuttings into the storage tank. The vertical conveyor is encased in a close fitting metal tube running the length of the auger. A lower aperture, facing the slinger of the horizontal conveyor, receives ice cuttings from the slinger, whereby the cuttings begin ascending on the flights. An aperture at the top faces the ice cuttings storage tank. The vertical conveyor slinger paddles throw the ice cuttings into the tank.
Behind the blade and draw bar is a wash water system that discharges cold water through a manifold that sits parallel to the blade. The wash water system includes a rubber squeegee mounted on the bottom of the back wall of the conditioner and a suction pump with an intake that projects nearly to the surface along that back wall. In operation, cold water from a tank in the main body is discharged onto the ice surface just behind the blade assembly, and is constrained by the conditioner's side runners and the squeegee as the machine moves forward. By regulating the flow of water and the suction of the collection pump, the operator maintains a wash water pool of constant size behind the blade assembly. This moving pool floats contaminants off the ice surface and floods any deep grooves and pits in the ice surface, then is collected and returned to the water tank.
The last part of the conditioner is the ice maker, mounted to the back wall of the conditioner. A discharge manifold sprays multiple small jets of hot water from a tank in the main body onto the outside back wall of the conditioner, where it forms a continuous sheet of water cascading down onto the ice across the conditioner's entire width. Finally a cloth water spreader, called a “mop”, evenly spreads and polishes the ice making water into a smooth surface.
Conventional ice re-surfacing machines suffer from build-up of ice particles in front of the horizontal conveyor. Because of conditions during operation, some ice cuttings from the blade, thrown by the horizontal conveyor's slinger, strike the areas around the mouth of the vertical conveyor and fall onto the ice in front of the horizontal conveyor. Additionally, the horizontal conveyor throws some of the cuttings it collects forward onto the ice along the entire length of the conveyor. While some of these cuttings are re-swept by the flights of the horizontal conveyor, some join up so as to form an obstructing build up that fuses together and prevents ice cuttings on the surface of the ice in front of the conditioner from ever getting swept into the containing tank. The present invention modifies the conveyor so it forces any solidified ice cuttings buildup being pushed forward by the conveyor into the space swept by the conveyor flights.
SUMMARY OF THE INVENTION
The horizontal conveyor of the current invention does not use the conventional circular cross section and constant radius on its auger flights. Instead, the conveyor is bisected lengthwise into two halves along the axis of its central shaft, with each half having a different radius. A small difference in radius between two “halves” aids in displacing built up ice cuttings and forcing ice to be swept by the conveyor flights rather than be pushed forward.
DRAWINGS
FIG. 1 is a schematic of an ice resurfacing machine.
FIG. 2 shows a side view of a vertical conveyor in respect to the conditioner.
FIG. 3 shows a side view of a vertical conveyor with the path of the ice cuttings from the horizontal conveyor to the storage tank.
FIG. 4 is a top view of the horizontal conveyor and vertical conveyor.
FIG. 5 is a side view of the ice cuttings during operation.
FIG. 6 is a side view of ice cuttings showing a pattern of build-up.
FIG. 7 is a side view of ice cuttings showing blocking build-up.
FIG. 8 is a top view of the horizontal conveyor showing ice build-up.
FIG. 9 is a top view of one embodiment of the conveyor of the present invention.
FIG. 10 is an end view of a flight in the conveyor of FIG. 9 .
FIG. 11 is a depiction of the flight of FIG. 10 with the radius differential exaggerated.
FIG. 12 is an illustration of one embodiment of the invention in operation.
FIG. 13 is an illustration of one embodiment of the invention in operation.
FIG. 14 is an illustration of one embodiment of the invention in operation.
FIG. 15 is an illustration of one embodiment of the invention in operation.
FIG. 16 is an illustration of one embodiment of the invention in operation.
FIG. 17 is an end view of another embodiment of the invention.
FIG. 18 is an end view of yet another embodiment.
FIG. 19 is a top view of an embodiment of the invention.
FIG. 20 is a top view of an embodiment of the invention incorporating flights of different radii.
DETAILED DESCRIPTION
A schematic of a standard ice resurfacing machine is shown in FIG. 1 . Main body ( 10 ) encloses an internal combustion motor or electric motor for propelling the unit and powering other components. It also encloses a storage tank for ice shavings, tanks for wash water and ice making water, and an operator's seat and controls ( 11 ). The sled or conditioner ( 12 ) is attached to main body ( 10 ) by hydraulic arms ( 13 ).
FIG. 1 shows only some of the components of conditioner ( 12 ). A horizontal conveyor ( 14 ) for moving ice shavings to the center and throwing them onto a vertical conveyor ( 9 ) is placed forward of shaving blade ( 15 ) mounted to draw bar ( 16 ). Remaining elements of the conditioner are not shown.
FIGS. 2-4 show the flow of ice cuttings during operation. Horizontal conveyor ( 14 ) collects ice cuttings generated by cutting blade ( 15 ). The helical flights ( 18 ) are oriented so that cuttings are swept from the outside toward the center, where slinger paddles ( 19 ) throw the cuttings at the open mouth ( 21 ) of vertical conveyor assembly ( 9 ). The flights ( 22 ) of a vertical auger or conveyor carry the cuttings upward to the top ( 23 ) of the conveyor, where they are engaged by the vertical slinger paddles ( 24 ) and flung into the storage tank.
The problem with ice build-up in front of the horizontal conveyor is shown in FIGS. 5-8 . As seen in FIG. 5 , a spray of loose ice cuttings is constantly thrown out of the front side of the horizontal conveyor by both the slinger and the centrifugal effect caused by the conveyor's rapid spinning. Some cuttings bounce off the vertical conveyor housing and others fall on the ice in front of the machine. Under certain environmental conditions, ice cuttings form clumps instead of remaining as a fine powder. These clumps may be thrown forward as shown in FIG. 6 . If clumps do not fall within the space between the auger flights of the horizontal conveyor, the clumps will be struck by the leading edge of a flight, pushing the clump forward. If clumps are not ingested by the conveyor, they may be combined with thrown ice particles and other clumps to form a build-up that increases in size and weight as the machine moves forward. FIGS. 7 and 8 show an example of build-up in front of the horizontal conveyor.
The ice build-up under the most adverse operational conditions, such as slush on the ice or extreme cold, can become solid enough to support very high pressures exerted by the horizontal conveyor, resulting in a build-up that obstructs the conveyor system, compromising the quality of the resurfacing run. It is possible for the blockage to exert enough force that the machine's rubber-tire-on-ice traction cannot overcome it, resulting in a stopped machine and an aborted conditioning run.
In one embodiment of present invention shown in FIGS. 9-11 , the horizontal conveyor ( 14 ) uses a double flight design, with two helical auger flights ( 31 , 32 ) winding around the conveyor's central shaft, ( 33 ) and two slinger paddles ( 34 , 35 ) used in the central slinger section. This new design does not use a circular cross section, and does not use a constant auger flight radius. Instead, the conveyor is bisected length wise into two halves along the axis of the conveyor's central shaft. The two conveyor halves have semi-circular cross sections, and create an overall shape of two hypothetical half cylinders of different radius, with each half covering 180 degrees of the 360 degrees of rotation around the conveyor's central shaft.
The semi-circular cross sections of the two half cylinders share a common radius center ( 36 ) along the axis of the conveyor's central shaft ( 33 ). The two halves differ from each other only in that they have different cross sectional radii, with the radius of one half being slightly smaller than that of the other half. Consequently, the conveyor can be described has having a larger radius half, ( 37 ) and smaller radius half, ( 38 ) separated from each other by a bisecting plane ( 39 ) extending along the axis of the conveyor's central shaft ( 33 ). The difference in length between the larger and smaller flight radii used by the new conveyor design is the conveyor's “radius differential”. The size of the radius differential is exaggerated in FIG. 11 for visual clarity.
In this embodiment, as each flight winds around the shaft, the flight uses the radius of the half that it is winding through, changing cross sectional radius as its rotation causes it to cross from one half into the other. The conveyor does not use one cross sectional radius exclusively on one of the two flights winding around the central shaft, and a different radius exclusively on the other flight. Both flights use both the larger and smaller radii as they twist around the central shaft, winding back and forth between the larger and smaller radius “sides” of the conveyor.
At all points along the length of the central shaft, one flight is using the larger flight radius ( 37 ) when the other flight is using the smaller flight radius ( 38 ). There is no point along the new conveyor's length at which both of the two flights use the same flight radius. As a result, every part of any ice cuttings buildup being pushed by the new conveyor is subjected to contact with flights alternating between the larger and smaller flight radii. There is no point along the new design conveyor's length where the ice cuttings buildup is subjected to contact with only one flight radius. Every part of an ice cuttings buildup is alternately swept by flights of both the larger and smaller flight radii.
In order to remain balanced while spinning, the conveyor half using the smaller flight diameter radius is also equipped with counter weights ( 40 ) attached to the non-thrusting side (the side of each flight that does not push ice cuttings) of each flight, close to the flight's outer edge. In one embodiment the weights ( 40 ) are attached to the smaller diameter flights exactly in the middle of the smaller diameter half of the conveyor with respect to the smaller diameter half's degrees of rotation around the central shaft. The weights compensate for the slightly lower weight of the conveyor flight flanges on the side of the conveyor using the smaller radius. The placement and size of any counterweights will depend on the dimensions of the particular auger, and may readily be determined by one of ordinary skill in the art.
The design of this new horizontal ice cuttings conveyor forces any ice cuttings buildup that may front in front of the conveyor into the space swept by the conveyor flights by using the principle of “positive displacement”. Positive displacement of the ice cuttings occurs when the spinning flights of the horizontal conveyor are physically forced into the space occupied by the ice cuttings. Because two solid objects cannot occupy the same space, the ice cuttings must be displaced, or moved aside, by the intruding conveyor flight. Thus the ice cuttings are “positively displaced”, meaning they must be displaced and moved by the conveyor flights.
This new horizontal ice cuttings conveyor creates positive displacement of the ice cuttings buildup because edges of the conveyor pushing an ice cuttings buildup forward over the ice surface alternate between using the larger and smaller flight radii once each conveyor revolution. The process the alternating flight radii create is best illustrated by examining what would happen to a hypothetical, fully formed ice cuttings buildup, complete with a solidified and compacted face for the conveyor to push against, if it were placed in front of the new conveyor design. See FIGS. 12-16 .
As the conveyor rotates, the continuous transition of the flight edges between using the larger and smaller flight radii creates a repeating sequence of four distinct events that results in the rapid break up and removal of the ice cuttings buildup. The four events repeat each time that the conveyor completes one revolution. In the first of these four repeating events, show in FIG. 12 , the hypothetical ice cuttings buildup is in front of the conveyor's larger radius lengthwise half. Once in place, the buildup will initially be pushed over the ice surface just as it is pushed forward by the conventional conveyors currently in use that have a circular cross section. The buildup is initially pushed over the ice by the spinning edges of the larger radius conveyor flights rubbing against the ice cuttings buildup
The second of the four repeating events, shown in FIG. 13 , is for the conveyor to quickly remove all contact with and physical support for the entire ice cuttings buildup. As the new design conveyor rotates the conveyor flights pushing the ice cuttings buildup switch from the larger flight radius to the smaller flight radius. This transition produces an empty gap ( 41 ) very suddenly between the ice cuttings buildup's face and the spinning conveyor flight edges. The size of the gap is equal to the radius differential between the larger and smaller flight radii. The sudden creation of this gap removes the continual contact and support that conventional conveyors with circular cross sections provide to the face of the ice cuttings buildup. This temporarily removes the continual “spine-like” structural support that conventional horizontal conveyors with circular cross sections provide to the ice cuttings buildup.
The third of the four repeating events, shown in FIG. 14 , is to move part of the buildup into the space that must be swept by the flights on the larger radius lengthwise half of the conveyor. This is accomplished by quickly closing the gap in between the body of the ice cuttings buildup and the flight edges of the conveyor on the smaller radius lengthwise conveyor side almost immediately after the gap forms, and while the smaller radius side is still the side in position to push against the ice cuttings buildup. Because the ice re-surfacing conditioner is in continual forward motion, the conditioner naturally pushes forward to close the gap between the ice cuttings buildup and the edges of the conveyor's spinning flights. The gap is small enough that the normal rate of forward motion of the conditioner easily closes the gap in the time available before the larger diameter lengthwise half of the conveyor can rotate back into contact with the ice cuttings buildup. As a result, the gap is closed by the conditioner's forward motion and the ice cuttings buildup is back in contact with, and being pushed forward by the edges of the conveyor flights on the lengthwise side of the conveyor with the smaller flight radius. When being pushed forward by the lengthwise half of the conveyor using the smaller flight radius, the body of the ice cuttings buildup is closer to the conveyor's central shaft than when it is being pushed by the lengthwise half of the conveyor using the larger flight radius. As a result, when it is being pushed by the smaller radius conveyor half, part of the ice cuttings buildup lies inside space that will be swept by the lengthwise half of the conveyor using the larger flight radius.
The fourth of the repeating events, shown in FIG. 15 , is for the larger radius lengthwise half of the conveyor to rotate back into contact with the ice cuttings buildup, taking a “forced bite” out of the buildup. Just before the larger radius lengthwise half of the conveyor rotates back into contact with the ice cuttings buildup, the buildup is in contact with and being pushed forward by the smaller radius lengthwise half of the conveyor. In this situation, the part of the ice cuttings buildup that is closest to the conveyor lies inside part of the space that must be swept by the flights on the larger radius lengthwise half of the conveyor. This creates a “positive displacement” relationship between the ice cuttings buildup and the larger radius conveyor half. As the larger radius lengthwise half of the conveyor rotates back into contact with the ice cuttings buildup, the outer edge of the conveyor flights must pass through the same space occupied by the closest part of the ice cuttings buildup. See FIG. 16 . As a result, the conveyor is forced to take a bite out of the ice cuttings buildup, shearing off and removing the cuttings that make up the closest part of the ice cuttings buildup's face.
The four events repeat with each complete revolution of the conveyor. Consequently, a portion of the ice cutting buildup is removed with each revolution of the conveyor, repeating until the entire ice cuttings buildup is removed from in front of the conveyor. Since the horizontal conveyor normally spins at a several hundred revolutions per minute, the new design horizontal conveyor can eliminate a very large ice cuttings buildup in only a few seconds.
A large difference in flight radius between the two lengthwise halves of the conveyor, or “radius differential” is not needed. The radius differential between the two lengthwise halves only needs to be large enough to cause the conveyor to remove enough of a forming ice cuttings buildup with each revolution that the flow of ice cuttings into the front side of the conveyor is never obstructed. A flight radius differential between the two lengthwise halves of the conveyor of 1/16 th to ¼ th of an inch (1.5 mm to 6.5 mm) should be more than enough to prevent an ice cuttings buildup from obstructing the front of the horizontal conveyor.
There are several advantages to using the smallest radius differential possible that will still prevent the formation of an obstructing ice cuttings buildup. These include ease of conveyor manufacture while maintaining proper conveyor balance, achievement of the smoothest conveyor rotation and most even power consumption possible while actually removing any ice cuttings buildup, having the largest possible total conveyor flight surface area to achieve the most efficient removal of ice cuttings possible, and keeping the conveyor's power consumption as smooth as possible during normal collection and removal of the ice cuttings resulting from ice shaving.
Various alternative embodiments of the present invention will also be effective. A single-flight auger conveyor, rather than the preferred double-flight auger, may be employed. Configuration of the differential radius cross section may also be varied.
FIG. 17 shows one such variation. Transition ( 42 ) between the smaller radius portion ( 38 ) and the larger radius portion ( 37 ) remains abrupt, but there is not another abrupt transition after 180° of rotation. Instead, the radius if the flight continuously variable from the small radius ( 38 ) to the large radius ( 37 ). The flight may be configured so that the gradual change from the small radius to the large radius takes place over an entire rotation (360°), a half rotation (180°) or something in between. A transitional change from small radius and large radius may also be carried out in less than a half rotation.
As shown in FIG. 18 , for configurations that do have abrupt transitions ( 42 ) from small radius ( 38 ) to large radius ( 37 ) on opposite sides of the flight, those transitions may be more or less than 180° apart. This is illustrated by alternate transitions ( 43 , 44 ) in the figure. Again, note that in FIGS. 17 and 18 the Radius Differential is exaggerated for illustration.
Another embodiment of the invention is shown in FIG. 19 , with dimensions exaggerated for clarity. Each flight in this embodiment includes a sequence of larger radius ( 37 ) portions and shorter radius ( 38 ) portions with transitions ( 42 ) between. In this embodiment the flights should be arranged so that at any point along the length of the conveyor ( 45 , 46 , 47 ), one flight is using the larger radius and the other flight is using the smaller radius. In this embodiment, the flights change radius every 2 to 6 inches (5 cm to 15 cm).
Another embodiment is shown in FIG. 20 . In this two-flight configuration, both flights have a circular cross section. One flight has a larger radius ( 37 ) and the other has a smaller radius ( 38 ). Again, the radius differential is small, and the figure exaggerates the magnitude of the radius differential. This embodiment maintains the desired positive displacement effect because all points along the length of the conveyor shaft use flights of both radii. Consequently, all points along the length of an ice cuttings build-up are alternatively contacted by flights of both radii. generating the desire positive displacement effect.
The invention is suitable as a retrofit modification for existing ice resurfacing machines, as the new design conveyor can be dimensioned to match the fittings of the horizontal conveyor on any of the standard resurfacing machines.
The foregoing description of a preferred embodiment of the invention has been presented and is intended for the purposes of illustration and description. It is not intended to be exhaustive nor limit the invention to the precise form disclosed and many modifications and variations are possible in the light of the above teachings. The embodiment was chosen and described in order to best explain the principles of the invention and its practical application and to enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed for carrying out the invention. | The horizontal conveyor of an ice re-surfacing machine implements auger flights in which successive half circles of the flight have slightly different radii. The successive contact of larger and smaller radius flights against ice building up in front of the horizontal conveyor breaks up and dissipates the ice. | 4 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a concrete embedded insert, called an anchor bolt locator, for properly locating and supporting a bolt or anchoring member during the pouring and curing of a concrete member, such that bolt will be properly placed in the cured concrete.
[0002] A concrete slab member is a common structural element of modern buildings. Horizontal slabs of steel-reinforced concrete are used to construct slab foundations, floors, ceilings, decks and exterior paving.
[0003] Concrete slabs are built using formwork—a type of boxing into which the wet concrete is poured. Typically, if the slab is to be reinforced, steel reinforcing rods are used, and these are positioned within the formwork before the concrete is poured. This steel reinforcing is often called rebar. Plastic tipped metal, or plastic bar chairs are typically used to hold the reinforcing rods away from the bottom and sides faces of the formwork, so that when the concrete sets it completely envelops the reinforcing rods. For a slab resting on the ground, the formwork may consist only of sidewalls pushed into the ground. For a suspended slab, the formwork is shaped like a tray, often supported by a temporary scaffold until the concrete sets. The formwork is commonly built from wooden planks and boards, plastic, or steel. After the concrete has set the formwork can be removed or remain in place. In some cases formwork is not necessary—for instance, a ground slab surrounded by brick or block foundation walls, where the walls act as the sides of the tray and the hardcore earth acts as the base.
[0004] Concrete slab members are also typically built in a manner that allows for anchor members and fasteners to be built into the slab so that other building elements can be easily and securely anchored to the concrete member. It is very common to see a slab with many different bolts and fasteners protruding from the slab after it has cured and the formwork has been removed. These preset anchors or inserts are typically used for securing pipes or conduits to concrete ceilings, or for securing framing to a concrete foundation or floor.
[0005] When anchors such as bolts and threaded rod are to be embedded in a concrete slab, they must be supported during the concrete pour. It is important that the anchors are located properly in the slab and remain undisturbed during the pour, so that subsequent building elements can be attached to them properly. The proper location of anchors in slabs is especially important for decks where the anchor will fasten a safety railing to the deck and for lateral force resisting systems where the anchors must be placed carefully to provide the proper anchorage without interfering with other structural members. Proper location is also important for the integrity of the anchor and the strength of the anchorage. If the anchor is set too close or at an improper angle so that it is too close to the sides of the slab water penetrating into the slab can degrade the anchor, and the strength of the anchorage is also compromised if there is insufficient concrete surrounding the anchor.
[0006] Typically, certain of the anchors located in the slab will be located close enough to the edges of the slab that they can be supported by a member attached to the side formwork during the pour. Other anchors will be located sufficiently far away from the sides of the form that they must be supported in some other manner. Sometimes the anchors can be tied to and supported by the reinforcing rods. Other times it is preferable to support the anchor on the underlying surface of the formwork. The present invention is a free-standing anchor bolt locator that attaches to the underlying formwork and holds an anchor or bolt during the concrete pour. Many such devices appear in the patent literature, including: U.S. Pat. No. 5,957,644, granted Sep. 28, 1999, to James A. Vaughan, U.S. Pat. No. 5,050,364, granted Sep. 24, 1991, to Michael S. Johnson et. al., and U.S. Pat. No. 5,205,690, granted Apr. 27, 1993, to Steven Roth.
[0007] The present invention improves upon the prior art by providing an anchor bolt locator that is inexpensively manufactured on automatic die-press machines from sheet steel and a structural nut that does not require any welding, while also being easy to use and install with current, commonly-used building practices and anchor designs.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention is to provide an anchor bolt locator, and a method for making an anchor bolt locator that is economically efficient to produce. It is also an object of the present invention to provide an anchor bolt locator that is easy to use and install. These objects are achieved by forming the chair of the anchor bolt locator out of sheet metal, and forming the anchor bolt locator in such a way that a structural nut can be permanently attached to the sheet metal chair without having to weld the nut to the chair. In this manner an anchor bolt locator is formed that can receive a piece of threaded rod in the nut in the typical fashion currently used for creating threaded rod anchorages with the nut at the proper height for such an anchorage. This type of anchorage is typical in the industry and uses two structural nuts sandwiching a structural plate washer between them. The structural nut of the present invention is designed to serve as the lower nut for a double-nut and plate washer anchorage. By avoiding welding the nut to the chair the structural integrity of the nut is better preserved, and the process does not need to include a welding station. Welding can crack nuts, especially if they are heat treated.
[0009] It is also an object of the present invention to provide an anchor bolt locator where the connection between the threaded rod and the locator is easily made. This object is achieved by providing a central opening in the anchor bolt chair that allows the user to precisely position the anchor bolt locator, while also providing tongues that serve as stop to prevent the anchor from being inserted too far into the structural nut. The threaded rod is rotated into the nut and tongues or prongs stop the threaded rod from being inserted farther than is necessary into the nut. If the anchor is threaded too far into the nut, the bottom of the anchor may be placed too close to the bottom of the concrete form which can lead to degradation of the anchor, and it will also mean that less of the anchor protrudes from the top of the form for attaching other devices.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1A is a perspective view of the anchor bolt locator of the present invention.
[0011] FIG. 1B is an alternate perspective view of the anchor bolt locator of the present invention.
[0012] FIG. 1C is an exploded, perspective view of the anchor bolt locator of the present invention, showing the placement of fasteners to secure the anchor bolt locator.
[0013] FIG. 1D is a perspective view of the anchor bolt locator of the present invention, attached to and set in a concrete slab form.
[0014] FIG. 1E is a side view of the anchor bolt locator of the present invention, attached to and set in a concrete slab form, showing the concrete in the form.
[0015] FIG. 2A is a plan view of the blank of the chair of an anchor bolt locator of the present invention.
[0016] FIG. 2B is a plan view of a chair of an anchor bolt locator of the present invention, after openings have been cut in the chair, and the depression and the legs bent from the bridge of the chair.
[0017] FIG. 2C is a plan view of an anchor bolt locator of the present invention. The structural nut has been attached to the chair.
[0018] FIG. 2D is a sectional view of a chair of an anchor bolt locator of the present invention taken along line 2 D- 2 D of FIG. 2B .
[0019] FIG. 2E is a sectional view of a chair of an anchor bolt locator of the present invention taken along line 2 E- 2 E of FIG. 2B , with a structural nut shown above the chair and ready for placement in the chair.
[0020] FIG. 2F is a partial sectional view of an anchor bolt locator of the present invention similar to FIG. 2E , with the structural nut now set in place on the chair, and the chair having been modified to frictionally engage the nut, securing it in place.
[0021] FIG. 3A is a plan view of a blank of a chair of an anchor bolt locator of the present invention. The anchor bolt locator shown in FIGS. 3A-3F is similar to the anchor bolt locator shown in FIGS. 2A-2F , except the anchor bolt locator shown in FIGS. 3A-3F receives a smaller structural nut.
[0022] FIG. 3B is a plan view of a chair of an anchor bolt locator of the present invention, after openings have been cut in the chair, and the depression and the legs bent from the bridge of the chair.
[0023] FIG. 3C is a plan view of the anchor bolt locator of the present invention. The structural nut has been attached to the chair.
[0024] FIG. 3D is a sectional view of the chair of the anchor bolt locator of the present invention taken along line 3 D- 3 D of FIG. 3B .
[0025] FIG. 3E is a sectional view of the chair of the anchor bolt locator of the present invention taken along line 3 E- 3 E of FIG. 3B , with the structural nut shown above the chair and ready for placement in the chair.
[0026] FIG. 3F is a partial sectional view of the anchor bolt locator of the present invention similar to FIG. 3E , with the structural nut now set in place on the chair, and the chair having been modified to frictionally engage the nut, securing it in place.
[0027] FIG. 4A is a plan view of a blank of a chair of an anchor bolt locator of the present invention. The anchor bolt locator shown in FIGS. 4A-4F is similar to the anchor bolt locator shown in FIGS. 2A-2F and FIGS. 3A-3F , except the anchor bolt locator shown in FIGS. 4A-4F receives an even smaller structural nut.
[0028] FIG. 4B is a plan view of a chair of an anchor bolt locator of the present invention, after openings have been cut in the chair, and the depression and the legs bent from the bridge of the chair.
[0029] FIG. 4C is a plan view of the anchor bolt locator of the present invention. The structural nut has been attached to the chair.
[0030] FIG. 4D is a sectional view of the chair of the anchor bolt locator of the present invention taken along line 4 D- 4 D of FIG. 4B .
[0031] FIG. 4E is a sectional view of the chair of the anchor bolt locator of the present invention taken along line 4 E- 4 E of FIG. 4B , with the structural nut shown above the chair and ready for placement in the chair.
[0032] FIG. 4F is a partial sectional view of the anchor bolt locator of the present invention similar to FIG. 4E , with the structural nut now set in place on the chair, and the chair having been modified to frictionally engage the nut, securing it in place.
[0033] FIG. 5A is a plan view of a blank of a chair of an anchor bolt locator of the present invention. The anchor bolt locator shown in FIGS. 5A-5F is similar to the anchor bolt locator shown in FIGS. 2A-2F , FIGS. 3A-3F and FIGS. 4A-4F , except the anchor bolt locator shown in FIGS. 5A-5F receives an even smaller structural nut.
[0034] FIG. 5B is a plan view of a chair of an anchor bolt locator of the present invention, after openings have been cut in the chair, and the depression and the legs bent from the bridge of the chair.
[0035] FIG. 5C is a plan view of the anchor bolt locator of the present invention. The structural nut has been attached to the chair.
[0036] FIG. 5D is a sectional view of the chair of the anchor bolt locator of the present invention taken along line 5 D- 5 D of FIG. 5B .
[0037] FIG. 5E is a sectional view of the chair of the anchor bolt locator of the present invention taken along line 5 E- 5 E of FIG. 5B , with the structural nut shown above the chair and ready for placement in the chair.
[0038] FIG. 5F is a partial sectional view of the anchor bolt locator of the present invention similar to FIG. 5E , with the structural nut now set in place on the chair, and the chair having been modified to frictionally engage the nut, securing it in place.
DETAILED DESCRIPTION OF THE INVENTION
[0039] FIG. 1A , shows the preferred, non-welded anchor bolt locator 1 of the present invention made from a galvanized sheet metal chair 2 and a structural nut 3 attached to the chair 2 by way of a friction fit.
[0040] As shown in FIG. 1A , preferably the chair 2 of the anchor bolt locator 1 is a u-shaped body having a bridge 4 that connects two legs 5 and 6 . Preferably, the bridge 4 is substantially rectangular with pairs of opposed sides and the legs 5 and 6 of the chair 2 are connected to the bridge 4 at one pair of opposed sides. Preferably, the legs 5 and 6 of the chair 2 depend from the bridge 4 at right angles to the bridge 4 . Preferably, the plurality of legs 5 and 6 extend away from the top surface 7 of the of the bridge 4 .
[0041] As shown in FIGS. 1 E and 2 D- 2 F, the bridge 4 is formed with a depression 8 that receives the structural nut 3 . The structural nut 3 is connected to the bridge 4 by frictional engagement and is held securely in place. The inner surface 9 of the side wall 10 of the depression 8 in the bridge 4 frictionally engages with the outer surface 11 of the outer side wall 12 of the nut 3 . Preferably, the outer side surface 11 of the nut 3 is made with flat faces 13 to have a polygonal, preferably hexagonal, cross-section. As shown in FIGS. 1B , 2 C and 2 D, edge openings 14 may be formed in the side wall 10 of the depression 8 where the flat faces 13 of the outer surface 11 of the polygonal nut 3 meet at nut side edges 15 . These edge openings 14 are particularly needed when a deep depression 8 must be made for a tall structural nut 3 , and the metal of the side walls 10 must be particularly stretched to make the depression 8 . The edge openings 14 may also be formed in the side wall 10 to extend into the bottom floor 16 of the depression 8 where the nut side edges 15 meet the bottom end 17 of the nut. The side wall 10 of the depression 8 extends away from the top surface 7 of the bridge 4 .
[0042] As shown in FIGS. 2B and 2C , the depression 8 in the bridge 4 is formed with a bottom floor 16 that has a top surface 18 . As shown in FIGS. 1A-1E , the structural nut 3 is received in the depression 8 of the bridge 4 . As best shown in FIGS. 2C and 2E , the structural nut 3 has a top end 19 , a bottom end 17 , an internal, threaded bore 20 forming an internal, threaded side wall 21 , and an outer side wall 12 defining an outer surface 11 of the nut 3 . The bottom end 17 of the structural nut 3 rests on the top surface 18 of the bottom floor 16 of the depression 8 , and portions of the outer surface 11 of the outer side wall 12 of the structural nut 3 are in contact with and in frictional engagement with portions of the inner surface 9 of the side wall 10 of the depression 8 such that the structural nut 3 is secured to the chair 2 .
[0043] As shown in FIGS. 1A and 2E , preferably, the outer side wall 12 of the nut 3 extends at a right angle to the top and bottom ends 19 and 17 of the nut 3 . Preferably, the side wall 10 of the depression 8 in the bridge 4 extends at right angle to the generally planar portion 22 of the bridge 4 surrounding the depression, and the generally planar portion 22 of the bridge 4 surrounding the depression 8 extends at a right angle to the outer side wall 12 of the structural nut 3 .
[0044] Since the anchor bolt locator 1 is preferably made from thin sheet steel the bridge 4 and legs 5 and 6 are, preferably, generally planar, thin members. See FIGS. 2C and 2F . Preferably, a portion 22 of the bridge 4 surrounding the depression 8 in the bridge of the chair 2 is a substantially planar and relatively thin member. As such, the structural nut 3 between the top end 19 and the bottom end 17 will have a thickness that is substantially greater than the relatively thin portion 22 of the bridge 4 surrounding the depression 8 . Similarly, the depression 8 in the bridge 4 to accommodate the structural nut 3 will have a depth from the top surface 7 of the bridge 4 to the bottom floor 16 of the depression 8 , with portions of the side wall 10 of the depression 8 extending from the top surface 7 of the bridge to the bottom floor 16 of the depression 8 , and that depth of the depression 8 will be substantially greater than the relatively thin portion 22 of the bridge 4 surrounding the depression 8 .
[0045] As shown in FIGS. 1B and 2B , preferably, the depression 8 in the bridge 4 of the anchor bolt locator 1 is formed with an opening 23 in the bottom floor 16 . Preferably, the opening 23 is located at the center of the depression 8 and will align with the center of the internal bore 20 in the nut 3 . This allows for accurate placement of the anchor or threaded rod 24 . The opening 23 is preferably an irregular opening 23 that creates a plurality of tongues 25 that extend underneath and support the structural nut 3 at is bottom end 17 . Preferably, at least one of the tongues 25 that make up the bottom floor 16 of the depression 8 extends sufficiently inward from the side walls 10 of the depression 8 to extend past the internal side wall 21 of the structural nut 3 , so as to block the passage created by the internal bore 20 so as to interfere and stop the travel of any threaded rod or anchor 24 received and threaded into the internal passage 20 of the nut 3 past the bottom end 17 of the structural nut 3 .
[0046] As shown in FIGS. 1A and 1E , each leg 5 and 6 of the chair 2 is formed with a flow passage 25 to ensure that concrete 26 flows around and under the anchor bolt locator 1 and the threaded rod 24 attached to the nut 3 .
[0047] Mounting holes 27 are provided in the bridge 4 , preferably at all four corners of the bridge 4 . As shown in FIGS. 1C , 1 D and 1 E, fasteners 28 , preferably nails when the form board bottom 29 is wood, are inserted through the mounting holes 27 and fastened to the form board decking 29 , securing the anchor bolt locator 1 to the form 30 in the desired location.
[0048] The anchor bolt locator 1 is preferably formed from galvanized, stainless-steel formed in a sheet. Steel is sufficiently rigid, and can be cold-formed to grip the structural nut 3 after it has been placed in the depression 8 . In the preferred method of making the anchor bolt locator 1 , any openings that are to be made in the bridge 4 are formed first, usually with or right after the blank for the chair 2 is cut from the sheet stock. See FIGS. 2A , 3 A, 4 A and 5 A. Then, the depression 8 in the bridge 4 for receiving the nut 3 is formed and the legs 5 and 6 are bent down from the bridge 4 along bend lines 31 . See FIGS. 2B , 2 D, 3 B, 3 D, 4 B, 4 D and 5 B, 5 D. At the same time, embossments 32 are formed in the bridge 4 outwardly from the depression 8 . The depression 8 of the chair 2 is then ready to receive the nut 3 which is placed in the depression 8 . See FIGS. 2E , 3 E, 4 E and 5 E. The structural nut 3 is placed in the depression 8 so that portions of the outer surface 11 of the outer side wall 12 of the structural nut 3 are in alignment and in close proximity to portions of the inner surface 9 of the side wall 10 of the depression 8 . Once the nut 3 is received the embossments 32 formed outwardly from the depression 8 are clampingly pressed back into the original plane of the bridge 4 of the chair 2 . See FIGS. 2C , 2 F, 3 C, 3 F, 4 C, 4 F and 5 C, 5 F. This causes a spreading flow of the material of the embossments 32 toward the depression 8 which causes the side walls 10 of the depression 8 to be pressed against the outer side surface 11 of the nut 3 , causing frictional engagement that holds the structural nut 3 in place.
[0049] As shown in FIGS. 1B and 1C , preferably, the attachment between the anchor 24 and the nut 3 is made by means of corresponding threads 32 and 33 in the internal cavity 20 of the structural nut 3 and on the outer surface 34 of the anchor 24 . As shown in FIG. 1E , the anchor 24 is formed with an elongated shank 35 that can protrude above the top level 36 of the concrete slab 26 .
[0050] FIGS. 1D and 1E illustrate use of the invention. The anchor bolt locator 1 shown is used with a wood form 30 upon which concrete 26 will be poured. In FIG. 1D , rebar members 37 , a specific type of steel concrete reinforcing member, are shown placed in the form 30 . In FIG. 1D , chalk lines 38 are also shown on the bottom member 29 of the form 30 to aid in locating the anchor bolt locator 1 . The installer need merely look through the opening 20 in the nut 3 and line up the center of the opening 20 with the intersection of the chalk lines 38 . The installer then nails or screws the anchor bolt locator 1 to the bottom 29 of the form 30 by running the fasteners 28 through the mounting holes 27 in the anchor bolt locator 1 . Once the anchor bolt locator 1 is firmly fastened to the bottom 29 of the formwork 30 , the appropriate anchor 24 or threaded rod is inserted and threaded onto the nut 3 , until the tongues 25 of the depression 8 stop its further downward travel. As shown in FIG. 1E , typically a washer 38 will then be placed over the anchor 24 so that it rests on the top surface 19 of the structural nut 3 and a second structural nut 39 will be threaded onto the anchor 24 so that it engages the top surface of the washer 38 . This type of double-nut-washer anchorage is commonly used in the industry, because the components are readily available and inexpensive, and yet well documented for their performance as anchors. Concrete 26 is then poured into the formwork 30 , so that the anchor bolt locator 1 , the structural nuts 3 and 39 , the washer 38 , and the threaded rod 24 are all surrounded and embedded in the concrete 26 with the top of the threaded rod 24 or anchor protruding from the top surface 36 of the concrete 26 . When the concrete 26 hardens the form 30 can be removed. If there is access to the bottom 29 of the form 30 , it can be removed as well and the ends of the fasteners 28 that were driven into the bottom formwork 29 can be broken off where they protrude from the concrete foundation 26 . | An anchor bolt locator is provided that is inexpensively manufactured on automatic die-press machines from sheet steel and a structural nut that does not require any welding, while also being easy to use and install with current, commonly-used building practices and anchor designs. The anchor bolt locator is made from a galvanized sheet metal chair and a structural nut attached to the chair by way of a friction fit. | 4 |
BACKGROUND OF THE INVENTION
1. Technical Field
The invention relates to a luminaire with at least one LED as luminous means and a method for operating the luminaire.
2. Prior Art
The light intensity of luminaires with LEDs is subject to fluctuations depending on the age and on the temperature of the LEDs. The ageing process has a particularly serious effect. A reduction of the light intensity to just 50% or less is possible. The light intensity changes only slowly and the alteration can hardly be perceived from the vicinity of operators.
A reduction of the light intensity is particularly critical in connection with applications for which specific luminous ranges are legally prescribed. A main area of application of the invention is navigation luminaires on ships. Luminaires of this type are also referred to as position lanterns and must have a luminous range of two nautical miles in the USA, for example. Other countries have in part different regulations.
When the light intensity of the LED decreases, the actual luminous range may fall below the legally prescribed value, so that the envisaged function is no longer fulfilled. Even without the presence of legal provisions, maintaining a specific light intensity for a luminaire is advantageous and desirable, for instance for illuminating traffic areas or properties or in connection with other types of signal and position luminaires.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to provide a luminaire which enables a minimum light intensity to be complied with. In particular, the intention is to comply with a defined or even Constant light intensity.
The luminaire according to the invention is characterized by the following features:
a) a sensor for detecting at least a part of the light emitted by the LED, b) a control unit for evaluating the sensor signals and for influencing the LED in a manner dependent on the sensor signals.
In the simplest case, the control unit switches off the LED after a limit value of the light intensity has been undershot. The luminaire or LED can then be identified as defective and can be exchanged. Preferably, precisely one LED is provided as luminous means.
According to a further concept of the invention, it is provided that the control unit regulates the electric current of the LED (LED current) in a manner dependent on the sensor signals such that the light intensity of the LED remains above a reference value. After the luminaire has been switched on, the light intensity of the LED is detected by means of the sensor and adapted by regulating the LED current until a desired value is reached.
According to a further concept of the invention, a reference value for a desired light intensity of the LED is defined by the control unit as follows:
a) after the luminaire has been switched on for the first time, a desired value of the light intensity is determined as reference value in a manner dependent on the sensor signals then present. b) the reference value is stored by the control unit.
The luminaire is switched on for the first time preferably in the absence of ambient light in order that the sensor exclusively receives light from the LED.
In an advantageous manner, the control unit prescribes a defined LED current when the luminaire is switched on for the first time. Said current can be stored in the control unit and is adapted to the structural and electrical data of the LED. The aim is a light intensity that suffices for the envisaged luminous range at the beginning of the service life of the LED. An increase in the LED current is intended to be necessary only with incipient ageing.
According to a further concept of the invention, the control unit permanently or cyclically compares the sensor signals with the reference value. In the event of the reference value being undershot, the control unit raises the LED current by a defined step from a present current value to a new current value. The new current value is then stored as present current value.
In an advantageous manner, when the luminaire is switched on again, the control unit prescribes the present current value that was stored last as LED current.
According to a further concept of the invention, the control unit raises the current value only up to a defined maximum value. It is thereby possible to avoid damage due to an excess of electrical power, for instance excessively great heating.
In an advantageous manner, the control unit concomitantly counts the operating hours of the LED after the current value has reached the maximum value.
The operating hours incurred after the maximum value has been reached are stored. Preferably, the control unit no longer switches on the LED if a defined number of operating hours has been reached. The defined number of operating hours is referred to as waiting time. Only after the waiting time has elapsed is it assumed that the luminaire no longer fulfills the intended purpose of use. The luminaire is then defined as defective. However, the luminaire is preferably not switched off during operation in progress. The control unit only prevents the luminaire from being switched on again as soon as the waiting time has been exhausted. This is particularly important and expedient for applications in which the luminaire is regularly switched on from time to time and, at the same time, an automatic switch-off during operation might have fatal consequences. Thus, by way of example, navigation luminaires on ships are not permitted to be automatically switched off suddenly at night.
An LED switch-off effected by the control unit means that a later attempt to switch on the luminaire does not lead to the LED lighting up.
According to a further concept of the invention, a light deflection device for the concentration or at least deflection of the light emitted by the LED is provided, at least a part of the light being deflected in the direction of the sensor by the light deflection device. The light deflection device may be a lens, a prism or a mirror, or else a combination thereof, e.g. a lens with partly mirroring or prismatic areas. A navigation luminaire with LED and essentially prismatic light deflection device is described in our European Patent Application EP 1 470 999 A2. Reference is expressly made to the disclosure of this application.
In an advantageous manner, the light deflection device deflects the light such that one part of the light is emitted by the luminaire and another part, in particular a smaller part, of the light is deflected in the direction of the sensor.
In an advantageous manner, the light deflection device has an in particular rod-type extension that extends in the direction of the sensor. In this respect, the extension acts as an optical waveguide with a light exit area facing the sensor.
According to a further concept of the invention, the LED defines an installation plane, a main emission direction of the light pointing away from the installation plane, and the sensor being arranged on the opposite side of the installation plane with respect to the main emission direction of the light. The sensor can be positioned in a manner protected by this arrangement, even with regard to the evolution of heat by the LED and the light emitted overall by the LED. The main emission direction preferably extends perpendicular to the installation plane.
According to a further concept of the invention, the extension extends (counter to the main emission direction) to behind the installation plane. As a result, the light separated off for the sensor is reliably conducted as far as the sensor. It is also possible to shade the sensor with respect to the light emitted overall. In an advantageous manner, the extension extends as far as the sensor. Light losses are thereby minimized.
According to a further concept of the invention, the light deflection device is arranged in front of a wall, the extension extending through a cutout in the wall. The wall is opaque to the light and shades the sensor from the light emitted overall by the LED. The wall may be part of a housing of the luminaire.
The method according to the invention for operating the luminaire is characterized by the following features:
a) after the luminaire has been switched on, a specific LED current flows, b) the light intensity of the LED is checked, c) in the case of a light intensity below a reference value, the LED current is raised by a defined value, d) steps b) and c) are repeated until the light intensity lies above the reference value.
The steps are carried out in the control unit. The latter is provided with a corresponding logic.
According to a further concept of the invention, the following method steps are provided:
a) each time the LED current is raised, a check is made to ascertain whether an upper limit value of the LED current is reached, b) if the upper limit value has been reached, the LED current is not raised any further, not even when the light intensity decreases.
The aim is to avoid additional damage within the luminaire or at the connected current source.
According to a further concept of the invention, the following method steps are provided:
a) after the upper limit value has been reached, the operating hours (switch-on time) of the luminaire are counted, b) after a defined number of operating hours has been reached, the switch-on function of the luminaire is blocked.
In this case, the LED remains dark despite the luminaire being switched on. However, the LED is preferably not switched off during operation in progress after the defined number of operating hours has been reached.
Further features of the invention emerge from the claims and from the rest of the description.
BRIEF DESCRIPTION OF THE DRAWINGS
Advantageous exemplary embodiments of the invention are explained in more detail below with reference to drawings, in which:
FIG. 1 shows a flowchart for illustrating the control of a luminaire with LED,
FIG. 2 shows an exploded illustration of a luminaire with LED according to the invention, namely a stern luminaire as navigation luminaire on ships,
FIG. 3 shows a housing part with LED on a small circuit board in a perspective illustration,
FIG. 4 shows a rearward (relative to the direction of travel of the ship) plan view of the stern luminaire,
FIG. 5 shows a section through the stern luminaire along the line V-V in FIG. 4 ,
FIG. 6 shows a section through the stern luminaire in accordance with FIG. 4 along the line VI-VI,
FIG. 7 shows a plan view of the stern luminaire,
FIG. 8 shows a plan view of a rear side of the stern luminaire without a rear wall (front side or front wall as seen in the main direction of travel of the ship),
FIG. 9 shows a perspective illustration of the internals of the stern luminaire, namely a housing part with connecting link for receiving an LED and for bearing a lens,
FIG. 10 shows a plan view of the components corresponding to FIG. 9 , but without a lens,
FIG. 11 shows an exploded illustration of the constituent parts of a navigation luminaire according to the invention for the starboard side of a ship analogously to the stern luminaire corresponding to FIG. 2 ,
FIG. 12 shows a view of the starboard luminaire analogously to FIG. 10 , but from a somewhat different viewing angle,
FIG. 13 shows a view of the rear side of the starboard luminaire in accordance with FIG. 10 and analogously to FIG. 8 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A stern luminaire as navigation luminaire of a ship has the following parts in accordance with FIG. 2 :
A rear wall 20 , a circuit board 21 with electrical and electronic components and circuits for driving an LED 22 , a housing part 23 preferably made of aluminum, a small circuit board 24 with the LED 22 held centrally, a lens 25 , a light-transmissive covering 26 , a housing covering 27 and suitable fixing means, here a screw 28 with head covering 29 , nut 30 and spreading sleeve 31 .
The luminaire according to the invention constitutes a further development of the luminaires shown in EP 1 470 999 A2. There is correspondence with regard to the configuration of the lens 25 as far as the deflection of the externally visible emitted light is concerned. Significant deviations according to the invention in the construction of the lens 25 in relation to the representation in the aforementioned European patent application are explained in more detail further below. The light is emitted through the lens, in accordance with the legal regulations, essentially only via a laterally delimited sector of a horizontal plane.
The LED 22 is arranged fixedly on the small circuit board 24 . The latter has contacts 32 for the connection of electrical lines (not shown).
The housing part 23 essentially comprises a central housing wall 33 , on which is formed a connecting link 34 for receiving the small circuit board 24 . Furthermore, the housing wall 33 is provided with a peripheral side wall 35 . The latter has on the exterior a shoulder 36 for bearing a corresponding area (not shown) of the housing covering 27 .
The small circuit board 24 has a peripheral edge with cutouts 37 into which corresponding projections 38 of the connecting link 34 enter. Moreover, the cutouts 37 and projections 38 are arranged and designed such that the small circuit board 24 can be inserted into the connecting link 34 only in a defined position.
When the small circuit board 24 has been inserted into the connecting link 34 , this and the LED 22 bear as closely as possible on the housing wall 33 . The heat that arises is thus effectively dissipated or distributed over the housing part 23 altogether.
The essentially annular connecting link 34 is at the same time provided with cutouts 39 on the inside, corresponding projections 40 of the lens 25 being held in said cutouts. Further parts of the lens 25 rest on the exterior of the connecting link 34 (apart from an exception mentioned further below). Consequently, the lens 25 also has a precisely defined relative position with respect to the connecting link 34 and thus with respect to the housing part 23 .
The circuit board 21 is arranged in a manner resting on the rear side 41 of the housing wall 33 , said rear side being remote from the connecting link 34 , and may be held there for example by means of an adhesive-bonding connection. An internal space 42 is formed between the rear side 41 and the rear wall 20 and serves for receiving the components arranged on the circuit board 21 . The rear wall 20 has two cutouts 43 , namely for insertion of the spreading sleeve 31 and for the passage of electrical connecting lines 44 .
An essential special feature is a pin-type extension 45 on the lens 25 , to be precise essentially parallel to the projections 40 . The extension 45 is arranged at the edge, in particular at the corner, on the lens 25 and extends counter to a main emission direction—arrow 46 —of the LED 22 .
The housing wall 33 has a cutout or hole for the extension 45 , to be precise outside the connecting link 34 . As a result, the light from the LED 22 does not pass directly to the extension 45 . However, the extension 45 receives light only via its contact with the rest of the lens 25 or else part of the lens 25 . On account of the length of the extension 45 , a light exit area 48 at the end thereof lies in the region of the rear side 41 of the housing wall 33 .
The circuit board 21 is provided with a light-sensitive sensor 49 , which is arranged in direct proximity to the light exit area 48 and can be used to measure the light intensity of the LED 22 indirectly, namely via the lens 25 and the extension 45 . Furthermore, the circuit board 21 has a programmable control unit (not specifically shown) formed from electronic components which serves for driving the LED.
The housing covering 27 has a window 50 , into which the light-transmissive covering 26 is inserted from the inside. Directly beside the window 50 , the housing covering 27 has a cutout, namely a hole 51 for passage of the screw 28 . The light-transmissive covering 26 lies over a partly cylindrically curved outer light exit area 52 of the lens 25 , to be precise at a small distance in the region of a vertex 53 and at larger distances laterally alongside the latter, see FIG. 6 in particular.
The starboard luminaire in accordance with FIGS. 11 , 12 , 13 and also the port luminaire are constructed in an analogous manner. Angular connecting links 54 are provided in order to represent an obliquely lateral light emission. Moreover, the housing coverings 27 are provided with laterally offset windows 56 .
In the embodiment shown here, the luminaire has precisely one LED. The latter receives an LED current of approximately 200 mA at the beginning of its service life. The LED is maximally loaded with 350 mA.
For the stern luminaire, use is made of a light-intense white LED, in particular an LED from the manufacturer LUMILEDS Lighting LLC, San Jose, Calif., USA, preferably of the type LXHL-PD01 luxeon emitter (hemispherical dome). Of course, it is also possible to use LEDs from other manufacturers with similar specifications. The current values mentioned relate to the white LED. A green LED is used in the starboard luminaire and a red LED in the port luminaire. The colored LEDs have in some instances a higher luminous efficiency than white LEDs. The electrical values must be adapted correspondingly.
The operation of the luminaire and the function of the circuit are explained with reference to the flowchart in FIG. 1 . A distinction is to be made between
the first time that the luminaire is switched on, normal operation, the waiting mode, the defect mode.
Switching on for the First Time
The luminaire (lantern) is switched on for the first time in dark surroundings, so that the sensor 49 does not receive any light, preferably in the factory after production of the luminaire.
The luminaire is switched on. The LED remains off, however. Firstly, the sensor checks the presence of light. If light is detected, the LED continues to remain off. If the sensor 49 signals surroundings without light, the LED is switched on after a pause of 5 seconds. After a further 5 seconds, the light intensity measured by the sensor 49 is assumed as initial value and a light intensity that is up to 10% less than that is stored as desired value. The stored desired value is preferably 97% of the light intensity detected by the sensor. The desired value is also designated as reference value. Afterward, the LED automatically goes out or the luminaire is switched off manually.
Normal Operation
After the luminaire has been switched on in normal operation (middle branch of the flowchart in FIG. 1 ), the light intensity of the LED is measured. If the desired value (reference value) is undershot, the initial LED current is increased by a defined magnitude. The resultant LED current is stored as present current value. After a waiting time of 5 seconds, the light intensity is measured again by the sensor 49 and, if appropriate, the LED current is increased.
The light intensity of the LED decreases due to ageing. It is possible to maintain the light intensity by adapting the current value. In this case, the current value in the present example increases from initially 200 mA to a maximum of 350 mA. The increase is effected in discrete steps, preferably in 256 approximately identical steps.
Waiting Mode
After the maximum current value has been reached, a further increase in the current intensity is not recommendable. The thermal, mechanical and/or electrical safety of the luminaire might be jeopardized. Moreover, the luminaire is only operated for a specific time duration (waiting time) and can no longer be switched on after this has elapsed. The first time the desired light intensity is undershot with the maximum current value being present simultaneously, the waiting time begins; a waiting time flag is set. Starting from this point in time, the operating duration, in particular the operating hours of the LED, is counted and stored. After 200 hours have elapsed, the waiting time has elapsed and the LED is deemed to be defective.
Luminaires are usually switched on and off again dependent on daylight, so that a daily cycle is established with a cycle duration that is significantly shorter than the waiting time. As a result, enough time remains for the maintenance personnel to implement measures for exchanging the luminaire or just the LED.
In order to facilitate such measures, when the luminaire is switched on, firstly a check is made to ascertain whether the waiting time flag is set. If this is the case, the LED briefly flashes a number of times, in particular three times, upon switch-on and then lights up without any further interruption. The flashing LED makes the maintenance personnel aware of the imminent failure of the LED.
Defect Mode
After the waiting time has elapsed, the LED is deemed to be defective, although generally only light with a reduced light intensity is emitted. In the defect mode, the LED is no longer switched on. Correspondingly, when the luminaire is switched on, a check is made to ascertain whether the waiting time has elapsed. If so, the LED remains dark. In order to avoid a failure of the luminaire in darkness, the LED is not automatically switched off during operation in progress. It is only prevented from being switched on again after the waiting time has elapsed.
The signaling of a specific operating state of the LED depending on the light intensity and/or the LED current may be effected when the luminaire is switched on or off, in particular by means of a brief flashing mode of the LED.
The functions described for operation of the luminaire are realized in suitable electronic circuits (control unit) with corresponding software on the circuit board 21 . With knowledge of the functions described, the construction of such a circuit is possible for a person skilled in the art of electronics, even without effecting an inventive step in this case.
List of Reference Symbols:
20
Rear wall
21
Circuit board
22
LED
23
Housing part
24
Small circuit board
25
Lens
26
Light-transmissive Covering
27
Housing covering
28
Screw
29
Head covering
30
Nut
31
Spreading sleeve
32
Contacts
33
Housing wall
34
Connecting link
35
Peripheral side wall
36
Shoulder
37
Cutouts
38
Projections
39
Cutouts
40
Projections
41
Rear side
42
Internal space
43
Cutouts
44
Lines
45
Extension
46
Arrow
47
Cutout
48
Light exit area
49
Sensor
50
Window
51
Hole
52
Light exit area
53
Vertex
54
Connecting link
56
Window | The invention relates to a luminaire with at least one LED and a method for operating the luminaire. The luminaire has a sensor for detecting at least a part of the light emitted by the LED and also a control unit for evaluating the sensor signals and for influencing the LED in a manner dependent on the sensor signals. After the luminaire has been switched on, a specific LED current flows and the light intensity of the LED is checked. In the case of a light intensity below a reference value, the LED current is raised by a defined value. | 5 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part of my previously filed, copending U.S. application entitled “Rolled Window And Fixture Shroud System,” Ser. No. 10/899,940, Filed Jul. 28, 2004, which is a Continuation-in-Part of Ser. No. 10/719,256, filed Nov. 24, 2003, and entitled “Temporary Protective Shrouds For Protecting Windows And Fixtures During Construction,” which issued as U.S. Pat. No. 6,865,850 on Mar. 15, 2005.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to a shroud system for masking various items during construction to prevent paint, debris and the like from marring or defacing fixtures. More particularly, the invention relates to a masking system for actively shrouding window assemblies, bathroom fixtures, or other prefabricated modules installed during construction or remodeling with predefined extruded plastic elements that are adapted to be taped into place.
[0004] 2. Description of the Related Art
[0005] The modern building boom has been stimulated by a variety of factors, the most important one of which appears to be current low interest rates. During the last decade, sales of new residential units have approached or exceeded record levels almost every year. While the increased demand for housing has stimulated the residential construction industry, increasing jobs, profits and general activity in the area, time constraints placed upon the typical contractor have become burdensome. There is a constant rush to finish the job, as buyers are anxious to occupy new dwellings as soon as practicable. The construction boom has also created a skilled labor shortage, and in some areas, shortages of raw materials. As a result, construction costs have increased. At the same time, profit margins are constantly under threat. Successful contactors must work quickly and efficiently under constant pressure, while at the same time maintaining above-average quality control.
[0006] Partially because of the foregoing considerations, the use of various forms of pre-fabricated modules has become the norm in modern construction. For example, numerous bathroom and kitchen fixtures or modules exist. The trend is for units to be prefabricated as much as possible by the manufacturer, and to avoid the necessity of finishing or painting or coating these fixtures once installed. Modern bath and shower modules, for example, comprise upright, fiberglass units that need merely be placed upon subframes and then plumbed adequately for use. Windows of varying sizes and configurations are sold as separate, largely aluminum “fin frame” units that are quickly fitted to pre-configured, wooden sub-frames crafted by the carpenter at the job site and nailed into place. A variety of single-hung and double-hung sash windows are available in numerous sizes, styles and configurations. The use of fixtures and increased modularization in general enhance the contractors' speed and efficiency. At the same time, certain quality control problems have been aggravated.
[0007] Windows, bathroom fixtures and other modular items are installed midway through the construction process. Fin frame windows are nailed into place, and afterwards they are secured in place within the subframe by dry walling. During dry wall installation, numerous finishing steps are completed. Trimming and fitting steps generate significant dust and debris. The finishing steps include the application of tape, drywall “mud,” and sanding steps for smoothing. Wet mud can spill onto adjacent, unprotected fixtures or windows. Dust generated during sanding can quickly accumulate on exposed surfaces and structures. Hand tools required for the process may be inadvertently dropped onto exposed items, and surface marring or structural damage is not uncommon. Numerous other construction processes that follow add to the mess. For example, spackled ceiling finishing can result in the widespread broadcasting of spackling compound. Unprotected fixtures and windows will require vigorous cleaning before the house can be sold.
[0008] Compounding the foregoing problems is that workers often stand or lean upon fixtures during construction. Unshielded contact with hand tools, such as those held in worker's belts, or the application of force and weight prior to the completion of installation can cause damage. Dirty footprints can accumulate and add to the mess. Anything left unprotected is further subject to attack during painting. Drops of dried paint are difficult and time consuming to remove during cleanup.
[0009] Cleanup procedures following interior construction steps are intended to remove dust, debris and grime. However, it can be very difficult to remove paint stains from some devices, and it is virtually impossible to remove substantial surface blemishes caused by abrasion or impact with falling tools or equipment. Sometimes expensive shower or bathroom modules are inadvertently damaged by inappropriate worker short cuts, exemplified for example, by the common practice of temporarily placing hand tools and/or paint cans within shower stalls or upon window ledges. Sometimes even rigorous cleaning efforts cannot adequately cure surface blemishes or damage, and fixture replacement is necessitated.
[0010] The prior art has recognized the general problems outlined above. Diverse paint and masking devices that temporarily cover various interior surfaces are known. Protective drop cloths are commonly deployed to prevent damage to objects in work areas. Large drop cloths deployed from rolls may be used on walkways, patios, decks, and carpeted areas. Standard drop cloths afford reasonable protection, but they have certain disadvantages. For example, cotton drop cloths are not impermeable to certain fluids, so oil-based paint can pass through and deface the covered surface.
[0011] Window fixtures can be masked by paper or plastic sheeting secured to the frame periphery by adhesive tape. However, such conventional masking methods are inefficient. Substantial labor must be invested during both installation and subsequent removal. In the past, individual sashes have been covered by temporary plastic panels, which must be installed and then removed in separate time-consuming steps.
[0012] U.S. Pat. No. 2,934,392 shows an early, well-known window masking method.
[0013] U.S. Pat. No. 3,837,949 shows a protective masking system for windows wherein strips of sheet covering are unwound from a large reel and applied over the surfaces to be protected.
[0014] U.S. Pat. No. 4,398,495 issued Aug. 16, 1983 discloses a thin, sheet-like paint shield comprising intersecting longitudinal and transverse creases. The crease arrangement enables the shield to be conformed about irregular volumes such as corner moldings or the like. By flexing the shield about its longitudinal crease, the bent portion automatically snaps back into a coplanar relationship with the remaining portion of the sheet so that its maximum longitudinal length is again available for shielding while painting.
[0015] U.S. Pat. No. 4,263,355 issued Apr. 21, 1981 sets forth a paint shield for masking a carpet or floor edges. The paint shield is formed from sections of a flat strip of resilient material packaged in a roll. The strip is rolled flat and springs back to shape when unwound from the roll.
[0016] U.S. Pat. No. 4,510,986 issued Apr. 16, 1985 shows a shrouding system wherein magnetic tape strips are used to temporality attach a shroud around the entirety of a window.
[0017] U.S. Pat. No. 4,921,028 issued May 1, 1990 discloses a door hardware cover that can protect knobs and locks. A plastic sheet is adhesively attached to the base of the door hardware.
[0018] U.S. Pat. No. 5,042,656 issued Aug. 27, 1991 provides a door-shield in the form of a disposable envelope that functions as a protective sheath. The door to be protected is in effect sandwiched between its sides. The envelopes are formed as large plastic and paper sheaths are pulled onto the edge of a door opposite the door edge hinged to the frame. Once painting or decorating is complete, the envelopes are removed and discarded.
[0019] U.S. Pat. No. 5,058,340 issued Oct. 34, 1991 discloses a plastic film sheet and mounting method for shrouding large planar areas like ceilings. A plastic edge connector ultrasonically welded about the periphery of the region being protected grasps edges of the shroud. Heat is applied to tightly stretch the shroud into the desired position.
[0020] U.S. Pat. No. 5,103,593 issued Apr. 14, 1992 discloses a door shield for temporarily covering a door during construction. A polymeric rear layer mounts an accordion-pleated forward surface formed of parallel ribs to provide impact resistance. Magnetic and adhesive members are coextensively formed at a rear perimeter of the door for adherence of the structure to the door.
[0021] U.S. Pat. No. 5,107,643 discloses a system for protecting glass in windows and doors during construction. However, no means are provided for covering the window frame, such as the metallic frame periphery of a typical fin frame window, during original installation.
[0022] U.S. Pat. No. 5,230,738 issued Jul. 27, 1993 discloses a pliable masking device for covering a targeted area during construction activities.
[0023] U.S. Pat. No. 5,266,390 issued Nov. 30, 1993 discloses a plastic dropcloth comprising a layer of polypropylene film bonded to an intermediate layer comprising either polyethylene or polypropylene film. The polypropylene film absorbs and resists hydrocarbon liquids such as paint, wood stains, paint thinners, solvents and the like. In manufacture, the layers are fusion bonded together via heating units and pressure rollers
[0024] U.S. Pat. No. 5,330,814 issued Jul. 19, 1994 describes a protective cover pad having a backing sheet with a layer of adhesive and a removable strip of a flexible foam material, which is peelable from the adhesive surface. The strip of foam-like material has a greater thickness than the backing sheet and a greater width than either of the side portions of the backing sheet.
[0025] U.S. Pat. No. 5,441,769 issued Aug. 15, 1995 discloses a paint mask for shielding windows while painting the mullions disposed between adjacent panes. Each mask is made of flexible, plastic sheeting, and is sized to cover an individual pane of glass.
[0026] U.S. Pat. No. 5,468,538 issued Nov. 21, 1995 discloses a paint masking kit for windows and a method for masking windows. The kit comprises a plurality of reusable covers for shrouding a window periphery and plastic sheet material. The kit is applied to a window that is already installed, and no provision for mounting the system to a window that is being installed during original construction has been contemplated.
[0027] U.S. Pat. No. 5,658,632 issued Aug. 19, 1997 discloses a masking strip equipped with adhesive for affixation to various structures. The mask is first placed over an area to be protected, and a desired portion of the adhesive patch is peeled back to enable custom affixation.
[0028] U.S. Pat. No. 5,816,305 issued Oct. 6, 1998 discloses a method for protecting an object during application of a fluid onto a surface, and a drop cloth having a first layer made of non-woven fabric material and a second layer of plastic.
[0029] U.S. Pat. No. 5,921,282 issued Jul. 13, 1999 discloses a disposable protective cover for exposed plumbing fixtures.
[0030] U.S. Pat. No. 6,141,921 issued Nov. 7, 2000 provides a sheet-like weather barrier for windows and doors. Double-faced tape bonds a sheet to a window frame. A stiffening band strengthens the sheet. Means are provided to minimize stretching and avoid the necessity of measuring. However, there are no analogous extruded frame pieces disclosed or utilized. Further, the structure fails to provide a solution for protecting fixtures during initial construction.
[0031] U.S. Pat. No. 6,143,392 issued Nov. 7, 2000 discloses a drop cloth especially configured for railings and banisters. An elongated, protective cover is fabricated from a strip of plastic or treated canvas.
[0032] U.S. Pat. No. 6,165,269 issued Dec. 26, 2000 presents a kit for masking door and room hardware during painting. A variety of masks are configured for specific pieces of hardware, such as door hinges, door knobs, dead bolts, wall outlets and electric switches. A tapered cross section portion of each mask creates a fine edge that closely fits into the joint between the hardware and the door or wall.
[0033] As recognized in my U.S. Pat. No. 6,865,850 issued Mar. 15, 2005, a low-maintenance, temporary protective shroud for windows and other construction fixtures, that may be easily deployed and then removed by the contractor when either interior or exterior construction is completed, is highly desirable. An adequate shroud must be light-weight, protective, durable, tear-resistant, and liquid-proof. It must not interfere with normal construction. Preferably, the system must be adapted to quickly fit a variety of dimensions and sizes. Furthermore, quick adjustments to shroud size must be possible at the job site without time-consuming measuring and cutting. Once interior construction or remodeling is complete, the shroud must be removable as fast as possible.
[0034] One disadvantage with rolled systems is the lack of rigidity. Recently I have realized that all of the foregoing goals can be best achieved through a masking system involving cooperating, pre-sized, extruded pieces that are strong or rigid enough to hold their shape as they are applied about the framework at the job site. I have determined that a system involving resilient flexible extrusions that can quickly be applied to the framework periphery, and that will not change their shape or droop or fold during installation, is ideal.
[0035] Furthermore, while sheet portions of flexible plastic are necessary to cover the bulk of the window area (i.e., at the middle between frame portions), once the extrusions are properly installed, an unobstructed sticky adhesive surface can be exposed by peeling away peel strips, and the plastic sheets may easily be installed without worrying about folding, bending or drooping.
[0036] Another important problem with prior art window shrouding systems is that the must be removed or partially destroyed when it is necessary to open a window. During indoor construction, for example, partially-completed houses will lack air conditioning, and in the summer months some ventilation will be necessary because of the heat. Many construction workers smoke, and ventilation will be necessary in smoking areas. Thus, an adequate shrouding system installed over unfinished fin frame windows must enable construction workers to raise the window at least part way to allow ventilation. Window manipulation must be possible without removing or destroying or damaging the protective shroud system.
BRIEF SUMMARY OF THE INVENTION
[0037] This invention provides a masking or shrouding system for original window construction. The method can be used to effectively shroud fixtures, such as window assemblies, bathroom fixtures, shower modules, and other prefabricated fixtures, during various construction stages. The apparatus comprises a special extrusion that fits within the confines of fin frame windows and the like, and is secured after resultant construction, to form a mounting frame for subsequently applied sheets of covering plastic that protect the window.
[0038] During those facets of construction likely to raise and distribute dust and debris, any object upon which one of my shrouds has been deployed is isolated and protected from dust, debris, and inadvertent injury. Not only is cleanliness maintained, but damages from contact with humans or tools or spilled liquids like paint, dry wall mud, or the like is avoided. After the various construction steps are substantially completed, the shroud can be quickly and easily removed by cutting. Thereafter, the shroud and its extruded supports are cut or torn away and discarded. After caulking, no visible trace of the shroud or its supporting extrusions is left.
[0039] The preferred shroud material comprises plastic sheet material of acrylic plastic. Alternatively, polypropylene or polyethylene sheet may be used.
[0040] The preferred shroud is custom installed at the job site by first fitting sections of special shroud extrusion. The translucent extrusion is preferably made from acrylic, polypropylene or polyethylene plastic. The extruded stock material is cut into sections of appropriate length at the job site. Since the pieces fit or nest together, needed lengths are merely approximated, because length adjustments are possible merely by axially adjusting the pieces. For example, to cover a window, one or more elongated sections are cut for the sides, and they can be mated together and slidably adjusted to the right length. Shorter sections can be similarly manipulated for the top and bottom of the window structure.
[0041] Preferably, the stock material, and each shroud piece that is cut from the stock material, comprises a flat foot portion, a flat and spaced-apart body portion, and an adjoining middle portion connecting the foot and body portions. Preferably the stock materiel used for interior construction has a ramp-like middle portion that provides an offset. The ramp portion positions the body portion away from the lower foot portion, while maintaining them parallel. The outer edge of the foot portion and the body portion terminate in elongated lips that reinforce the structure and help align the panel pieces upon installation.
[0042] Numerous adhesive peel strips are defined beneath the extrusions to ease construction. After the elongated, adhesive peel strips beneath the foot portions of a given extrusion are removed, the piece may be attached to a window, for example, by adhesively affixing the foot portion to an exposed peripheral window surface. As the outer peripheral frame of the exposed window is covered top and bottom by extrusion pieces, the adhesive strips can fasten upper and lower horizontal extrusion pieces upon the vertical extrusion pieces installed first at the window sides. The affixed extrusion pieces form a mounting frame for receiving the plastic sheet that covers the window.
[0043] Adhesive strips are also affixed upon the exposed outer surface of the extrusions. Once the extrusions are fitted, the outer removable strips can be quickly peeled away, leaving an adhesive point of attachment for the plastic sheet material cut and attached in the form of a rectangular sheet. Alternative, exposed outer adhesive strips can mount or brace an overlying shroud piece.
[0044] Edges of the covering sheet are pressed against exposed adhesive patches to mount the sheet over the mounting frame. Once mounted in this fashion, either internally or externally, construction may progress and debris will be prevented from contacting the window. The waterproof sheet is preferably translucent. The sheet material is preferably acrylic plastic, but it may be made from polyethylene, polypropylene or other translucent polymer plastic materials.
[0045] Once installed internally, dry walling commences, and edge portions of the resultant mounting frame (i.e., edges of the extrusions) are thereby captivated and sandwiched permanently against portions of the window peripheral frame and adjoining dry wall segments. Afterwards, finishing steps may follow. For example, tape and mud may be applied, and sanding, painting, and other miscellaneous finishing tasks may be completed. The exposed peripheral junction between the resultant multi-piece shroud foot portion and the adjacent sheet rock may be cut. The cut extrusion portions and the shroud formerly supported thereby may then be torn away, removed, and discarded. The junction is then caulked for cosmetic effects along the cutting line. A clean, undamaged and unmarred fixture remains. Alternatively, the shroud may be formed from numerous sheets (i.e., in excess of two) to cover larger areas.
[0046] Thus, a basic object of my invention is to provide a low cost method for shrouding windows interiorly or exteriorly, from dust, debris, overspray, and miscellaneous dirt and debris during original construction.
[0047] Another basic object is to protect exposed surfaces of windows from debris and damages that might occur during construction.
[0048] A related object is to isolate windows from damages that might result from contact with workers, or miscellaneous construction tools used during construction.
[0049] It is also an object of the present invention to provide a new and useful method for protecting windows from construction fluids or substances including paint and other compounds or mixtures comprising hydrocarbon solvents.
[0050] Moreover, it is an important object of my invention to provide suitable extrusions for forming a semi-permanently affixed mounting frame that ultimately supports a shroud of sheet material over a window.
[0051] It is still another object of the present invention to provide a protective shroud system for windows that may be easily adjusted during installation to snugly fit a variety of sizes, shapes and configurations.
[0052] Another important object of my method and apparatus is to provide a protective shroud system for windows of the character described that temporarily enables ventilation then desired. It is a feature of my invention that the shroud need not be completely removed to open a window at least part way for ventilation when necessary.
[0053] A related object of this invention is to provide a protective shroud system of the character described that may be quickly and easily removed once construction is substantially finished.
[0054] Yet another object is to provide a highly durable shroud of the character described that is lightweight, puncture-resistant, and rapidly deployable over standard fin-frame windows of a variety of sizes and configurations.
[0055] Another object is to provide a shrouding method of the character described that is not only ideal for indoor use, but is adapted for outside use to protect windows from over-spray during painting, from mortar during brick-laying activities, or other dirt and debris.
[0056] A related object of my invention is to provide a customizable shrouding process that readily adapts for use with windows of different dimensions and configurations, either inside or outside a building.
[0057] Another important object is to enable the installer to accommodate different heights and widths of windows without time-consuming measuring or cutting steps. It is a feature of my invention that a pair of extrusions can be coupled together and rapidly axially adjusted as necessary to fit a variety of differently sized applications.
[0058] A major object is to provide a protective shroud system of the character described that, once removed from the window, is invisible, and leaves no trace of its former presence.
[0059] These and other objects and advantages of the present invention, along with features of novelty appurtenant thereto, will appear or become apparent in the course of the following descriptive sections.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0060] In the following drawings, which form a part of the specification and which are to be construed in conjunction therewith, and in which like reference numerals have been employed throughout wherever possible to indicate like parts in the various views:
[0061] FIG. 1 is a partially exploded, fragmentary isometric and pictorial view showing my interior shroud system being deployed within a building adjacent a conventional double sash, fin-frame window;
[0062] FIG. 2 is a fragmentary, exploded isometric view of the exposed periphery of a fin-frame window shown installed in FIG. 1 , showing a portion of my shroud extrusion that is fitted vertically to the window edge;
[0063] FIG. 3 is a fragmentary, exploded isometric view similar to FIG. 2 , showing an additional portion of shroud extrusion that is to be fitted horizontally over the top of the window edge and the previously installed vertical portion;
[0064] FIG. 4 is a fragmentary, exploded isometric view similar to FIGS. 2 and 3 , showing how the horizontal and vertical portions of the preferred shroud extrusions shown in FIGS. 2 and 3 fit together at corner regions;
[0065] FIG. 5 is an enlarged cross sectional view showing the best mode of my interior shroud extrusions, taken across lines 5 - 5 in FIG. 1 ;
[0066] FIGS. 6-10 are fragmentary, isometric and diagrammatic views showing the sequential application of my shroud system and succeeding construction materials or steps preferably used inside a building or dwelling;
[0067] FIG. 11 is a diagrammatic view of the final stage of shroud system use, showing the removal of exposed extrusion portions;
[0068] FIG. 12 is a fragmentary, isometric view of the exterior of a fin-frame window that has been protected with my exterior shroud extrusions, with the final plastic covering sheet omitted;
[0069] FIG. 13 is an enlarged, fragmentary isometric view of circled region 13 in FIG. 12 ;
[0070] FIG. 14 is an enlarged cross sectional view showing the best mode of my exterior shroud extrusions, taken generally across lines 14 - 14 in FIG. 13 ;
[0071] FIG. 15 is an enlarged, fragmentary, isometric view of the preferred exterior extrusion; and,
[0072] FIG. 16 is a fragmentary, diagrammatic view showing an example of exterior construction, with pieces omitted for brevity or broken away or shown in section for clarity.
DETAILED DESCRIPTION OF THE INVENTION
[0073] The present shroud system is an improvement and modification of my prior shrouding inventions which are the subject of my U.S. application entitled “Rolled Window And Fixture Shroud System,” Ser. No. 10/899,940, Filed Jul. 28, 2004, and my U.S. Pat. No. 6,865,850 issued Mar. 15, 2005 that is entitled “Temporary Protective Shrouds For Protecting Windows And Fixtures During Construction. For purposes of disclosure, the entire specification of these references is hereby incorporated by reference.
[0074] With initial reference directed to FIG. 1 of the appended drawings, a construction fixture, in this instance a prefabricated window assembly 32 , is to be shrouded and protected in accordance with the invention during building construction. The window assembly 32 is seen from the inside of the building in FIG. 1 . As used herein, the term “construction fixture” refers to a variety of fixtures and/or construction modules or frameworks or items that are commonly installed at job sites, such as kitchen fixtures, prefabricated windows, bathroom fixtures such as shower stalls and bathtubs, and various other prefabricated assemblies. Once my preferred indoor shroud system 28 is properly applied, subsequent construction steps may proceed, with the fixture protected from damage and marring. The shroud system 28 comprises a peripheral subframe 30 that is constructed at the job site and temporarily affixed about the window assembly 32 , and a covering sheet 29 of plastic that overlies the window and is supported by the subframe 30 .
[0075] Once a prefabricated window assembly 32 is protected as. described hereinafter, dry-wall construction and various ancillary and secondary construction steps may proceed non-destructively, during which time the window is protected from dirt and debris either inside or outside the building. According to the preferred method, a shroud subframe 30 , comprising a plurality of properly cut and interfitted plastic panels 42 , 44 is installed, and then a transparent sheet 29 is affixed to the shroud subframe 30 . Drywalling and other normal construction steps known in the art may proceed. After interior construction is substantially completed, the shroud system 28 is quickly removed and discarded, by tearing away the sheet 29 and cutting the exposed portions of shroud subframe 30 (i.e., the panels) as described hereinafter. This reveals a clean and undamaged fixture that does not require tedious and time-consuming cleaning.
[0076] Window assembly 32 ( FIGS. 1, 2 ) comprises a conventional, dual-sash, fin frame window 34 that is received by and nested within a generally rectangular, window enclosure 36 built into the substantially wooden framework of the building. Window 34 is formed from extruded aluminum pieces in a number of well-known configurations in varying sizes and aspect ratios, and the invention is not limited to any particular window design such as dual sash or fm frame designs. Normally each window sash 33 , 35 has a plurality of individual glass panes 31 disposed between alternate vertical mullions 47 and horizontal mullions 43 ( FIG. 1 ). Of course it should be recognized that single pane sashes exist as well. A thin, peripheral “fin” 40 with mounting orifices 41 is disposed at and around the exterior side of the prefabricated window 34 ( FIG. 2 ). This construction provides a stepped or notched structural profile comprising an offset periphery 37 , that enables flush mounting of the window within a suitable recessed receptive region formed by wooden framing, as is known in the art. Periphery 37 has an outer edge comprising a flat, surface portion 38 that is perpendicular to fin 40 , and a flat, integral peripheral surface 39 that is offset from and parallel with fm 40 . Peripheral surface 38 will be nested against the receptive wooden framing enclosure 36 . Window assembly surface 39 and the window glass panes and mullions will be shrouded by system 28 .
[0077] The shroud subframe 30 is made of several separate panels or pieces of panels that can be custom cut and fitted at the job site. Cut panels that are to be oriented vertically during installation are designated by the reference numeral 42 in FIGS. 1-3 . Similarly, cut panels that are to be oriented horizontally after installation in the illustrated example are designated by the reference numeral 44 ( FIGS. 1-3 ). As implied from FIG. 1 , numerous cut panel pieces 42 , 44 are adhesively pressed up and against periphery surface 39 to form and mount the subframe 30 . FIG. 1 also shows a generally rectangular auxiliary covering sheet 29 that affixed over the window once the shroud elements are affixed, which will be described hereinafter.
[0078] As best seen in FIGS. 2, 3 and 5 , panels or panel pieces 42 and 44 are all cut from the same elongated, stock of plastic material. Preferably the panel stock for the subframe 30 is made by extruding plastic, but it is contemplated that suitable panels may be made from blow-molded or even injection molded plastic stock. As best discerned from FIG. 3 , a given length of subframe can be formed from two overlapping pieces 42 A and 42 B. When cut, overlapping pieces such as 42 A and 42 B can be slidably axially adjusted relative to one another as indicated by arrow 49 . By moving the pieces either to extend or contract the resultant length, the composite panel 42 applied to the left side of the window (i.e., as viewed in FIG. 1 ) can be formed in virtually the exact length required without tedious measuring or cutting. Portion 42 A will be placed atop portion 42 B overlying it, so moisture, for example, dripping downwardly will be guided away from the window components. As detailed hereinafter, portions 42 B can be quickly fitted over portion 42 B by removing the peel strip 57 ( FIG. 2 ) to expose an adhesive strip that allows the individual extrusion pieces to be press fitted together.
[0079] Preferably each panel (and thus each subframe piece) is extruded. There is an elongated, flat body portion 46 that is integral with a spaced apart foot portion 48 . Portions 46 and 48 are joined by an integral, connecting middle portion 50 that effectively offsets body portion 46 from foot portion 48 , while maintaining them parallel. Preferably for interior work the middle portion 46 is inclined, forming a ramp. The offset ramp ultimately allows windows to be temporarily opened for ventilation, without removing the system. Body portion 46 , foot portion 48 , and ramp portion 50 are elongated and integral. The flat, planar body portion 46 is offset and spaced apart from planar foot portion 48 , and portions 46 and 48 are generally parallel. In the best mode the outermost edge of the foot portion 48 terminates in a downwardly turned lip 52 that effectively aligns the pieces upon installation by contacting and anchoring against surface 38 , upon edge 63 , as viewed in FIG. 4 . Preferably integral body portion 46 terminates in an upwardly turned lip 53 (i.e., FIG. 5 ) that helps align overlying pieces.
[0080] Preferably the panel stock material is water-proof and translucent, comprising acrylic plastic, but it may be made from polyethylene, polypropylene or other translucent polymer plastic materials. The thickness of the shroud body portions 46 and ramp portions 50 is preferably 0.020 inches in the best mode known to me at this time. Foot portion 48 is preferably thinner than the ramp or body portions (i.e., 0.010 inches) in the best mode, to facilitate rapid cutting (i.e., as in FIG. 11 ) when construction is complete so the shroud subframe can be quickly cut, removed and discarded. The elongated, parallel lips 52 and 53 reinforce the material to insure that panels cut from it are of adequate strength.
[0081] As viewed in FIGS. 2 and 4 , the subframe pieces are provided with numerous adhesive peel strips for assembly, each of which comprises an adhesive patch temporarily covered by a removable tear strip that can be removed to expose the adhesive. Preferably there are elongated, adhesive strips 54 A on the bottom of the panel pieces, i.e., they are disposed beneath the panel foot portions 48 with peel away strips 57 ( FIGS. 2, 5 ). There are similar elongated adhesive strips 54 B on the top of the panel pieces, i.e., on the outside of the subframe panel body 46 . Each adhesive strip has an internal adhesive patch 60 A covered (i.e., before deployment) by the peel strips 57 or 58 A ( FIG. 2 ). With the tear-away strips removed the adhesive patch 60 A is exposed, so the subframe panel piece may be press fitted against the window fixture periphery and installed. As appreciated from a comparison of FIGS. 2 and 4 , the peel strip 57 beneath the foot portion 48 can be removed so that subframe piece 42 may be pressed against and adhesively affixed to surface 39 . At this time, when the subframe piece is press-attached to the window frame surface 39 , lip 52 will abut and lie coextensively against corner 63 ( FIG. 2 ), which forms the boundary between aluminum surfaces 38 , 39 .
[0082] With a vertical subframe panel 42 affixed vertically as in FIG. 3 , a horizontal subframe piece 44 is affixed. At this time upper peel strip 58 A atop the body 46 of piece 42 is removed, to provide a connection point for the next subframe piece 44 . Similarly, the tear strip 57 ( FIG. 3 ) at the underside of the foot portion 48 of shroud piece 44 is removed, exposing an adhesive patch for connection to surface 39 . Referring to FIG. 4 , it will be seen that a portion of shroud piece 44 overlies the top of piece 42 . The underside of the body portion 46 of shroud piece 44 is thus adhesively secured to the outside of the body portion 46 of shroud piece 42 by the exposed adhesive patch designated by the reference numeral 66 ( FIG. 4 ). Construction of the subframe 28 proceeds similarly until panel pieces such as 42 , 44 surround the entire periphery of the window assembly 32 . Deployment of the resultant, generally rectangular subframe 30 proceeds as illustrated successively in FIGS. 6-9 . When the subframe 30 is completed, the generally rectangular, plastic sheet 29 ( FIGS. 1, 9 , 10 ) may be deployed.
[0083] As best seen in FIG. 4 , the tear strips 58 A on the outer surface of body 46 on each subframe piece may be removed to expose adhesive patches 60 A ( FIG. 4 ) that receive and secure a sheet 29 . In other words, the edges of sheet 29 may be pressed against exposed adhesive patches 60 A to mount the sheet 29 over the window as in FIG. 10 . Once mounted in this fashion, either internally or externally, the sheet 29 may be folded up over itself as in FIG. 9 . When the sheet is fully deployed as in FIG. 10 , its lower portion 68 may be deflected upwardly temporarily, should the covered window be opened. Noting FIG. 4 , it is preferred that a small piece 69 of masking tape be applied in the corner region of abutting panels.
[0084] Sheet 29 is preferably water-proof and translucent. The sheet material is preferably acrylic plastic, but it may be made from polyethylene, polypropylene or other translucent polymer plastic materials.
[0085] FIGS. 6-10 indicate successive steps of shroud installation, whereby the periphery of the window unit is covered by appropriately sized subframe panel pieces 42 or 44 . After the protective sheet 29 is installed ( FIGS. 9, 10 ), drywall or sheet rock pieces 70 can be installed, as described in detail in my above cited patent and pending application. The sheet rock is covered by mud and/or taping, generally designated by reference numeral 72 ( FIGS. 9, 11 ) before sanding and then painting. When necessary to expose the glass window panes, the sheet 29 can be curled or folded as in FIG. 10 , with its bottom disposed underneath the top of the sheet so that fluids or materials contacting the sheet are directed outwardly rather than inwardly. With finishing completed, the installer removes the exposed piece of the shroud subframe 30 by cutting with a knife 74 ( FIG. 11 ). The lesser thickness of the subframe foot portions 48 enables rapid cutting, substantially at the junction 80 ( FIG. 5 ) where the lower thickness foot portion begins. The foot portions of the subframe pieces will be concealed against the window by the drywall pieces, and cutting progresses to remove the body and ramp portions, which can then be discarded, as in FIG. 11 . Afterwards optional caulking, sanding and other finishing and/or painting steps may proceed, as known by those skilled in the art, and remnants of the subframe 30 will be completely concealed.
[0086] FIGS. 12, 13 , and 16 show the window from the outside of the building. During an initial phase of construction portions of the fin frame window will be covered by bricks, insulation panels, or whatever external siding materials are applied, as recognized by those skilled in the art. The brick exterior is represented by the reference numeral 121 , the window has been designated as 86 , and the external or outdoor subframe has been generally designated by the reference numeral 88 .
[0087] In this instance a different plastic stock is preferably used to make the outdoor subframe panels. Noting FIGS. 14-16 , the preferred outdoor stock extrusion 90 has a left foot 92 , an integral and coplanar body 93 on its right, and an upwardly offset middle 94 . Foot 92 terminates in downwardly turned lip 95 , and body 93 terminates in downwardly turned lip 96 . A peel-away adhesive strip 100 is disposed on the bottom of the panel pieces, beneath foot 92 , as seen in FIG. 14 . Another adhesive tear strip 102 is deployed on top of the panel pieces, preferably atop middle 94 . Lips 95 and 96 reinforce the structure, along with the opposite raised edges of the offset middle 94 . Each tear strip comprises an adhesive layer that is exposed by removing a tear strip.
[0088] Construction of the outdoor subframe 113 proceeds by cutting and sizing suitable panel pieces 106 ( FIG. 13 ), 109 , 110 , ( FIG. 16 ) in the manner described previously. Panel feet are affixed to exposed window frame portions 112 and affixed thereto by deploying the adhesive strip 100 in the manner described earlier. Preferably the lower ends of subframe panels 106 , 110 overlie the lower horizontally disposed panel 109 so that rain dropping down the surface will be directed outwardly instead of inwardly. When a window subframe 113 is completed, the peel-away strips from tear strips 102 are removed so that an appropriately sized plastic sheet may be deployed over the outside of window 86 . Importantly the outer plastic sheet fitted over the subframe 113 upon the exposed tear strips 102 can be curled upwardly to expose the clear window panes, with its bottom arranged and tucked inwardly beneath the upper portion of the sheet, as seen in FIG. 10 . This insures that water, for example, draining off the arrangement will be directed outwardly.
[0089] After the external wall, such as brick exterior 121 has been completed, and construction is finished, brick portions of the exterior will normally not overlie the panels 109 , or 110 . At this point the covering sheet can be pulled away, and the subframe can simply be peeled away also. When and if portions 109 , 110 of the subframe are covered by exterior bricks etc., the plastic sheet may be torn away and discarded, and the subframe 13 may be removed by cutting as before (i.e., with a knife as in FIG. 11 ). Portions of panel sides 92 will remain sandwiched and concealed within the wall structure, but they will not be visible.
[0090] From the foregoing, it will be seen that this invention is one well adapted to obtain all the ends and objects herein set forth, together with other advantages that are inherent to the structure.
[0091] It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.
[0092] As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense. | A shroud and construction methods using the shroud wherein windows are temporarily covered for protection. A shroud subframe comprising resilient, plastic extrusions is custom fitted about the window periphery. Each extrusion has an elongated foot, an offset body portion, and an integral ramp connecting the body and the foot. Each extrusion has a peel-away adhesive strip formed beneath the foot and atop the body. A translucent sheet of plastic is adhesively mounted on the subframe face. A region of overlap occurs between adjacent portions of the shroud subframe, and the pieces are adhesively fixed to one another. During subsequent construction steps, shroud foot portions are permanently sandwiched between dry wall segments and window structure. When construction is completed, the exposed junction between the subframe and adjacent sheet rock is cut and discarded, and the sheet is removed. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to digital rights management (“DRM”). More particularly, the present invention relates to techniques for managing devices implementing various DRM protocols.
[0003] 2. Background Art
[0004] A DRM protocol is a term that refers to any technological technique for controlling access to copyrighted content. The content can be, for example, a digital image, a video recording, or a music file. A DRM protocol is implemented in either software or hardware and generally includes components that are part of the application or electronic device using the content. Thus, a DRM protocol can be implemented by a DRM module that resides in the application or in the electronic device using the content.
[0005] For example, a DRM protocol used by a content provider might involve encrypting the content requested by a consumer and transmitting the encrypted content to an electronic device belonging to the consumer. Once the electronic device attempts to use or access the encrypted content, a DRM module implementing the DRM protocol may request a license from a predetermined license server. In response to this request, the license server can generate a license (also referred to as a “rights object”), which specifies the allowable uses of the content and which includes the decryption key for decrypting the encrypted content. The allowable uses for the content can be specified by the content provider and stored on the license server. The rights object can then be transmitted to the electronic device, thereby allowing the DRM module to decrypt the encrypted content and to permit the electronic device to use the content in accordance with the allowable uses specified by the rights object.
[0006] Thus, it is critical for the license server to properly identify the electronic device prior to transmitting the rights object in order to prevent unknown or unauthorized electronic devices from using the content. Today, a single user may use a number of different electronic devices to access the license server. As such, a more flexible licensing approach is needed that allows the user to conveniently share the content among her various electronic devices. However, since various electronic devices can implement various DRM protocols, conventional license servers configured for one DRM protocol cannot properly identify electronic devices implementing various other DRM protocols.
SUMMARY OF THE INVENTION
[0007] There are provided methods and systems for identifying a device implementing a DRM protocol, substantially as shown in and/or described in connection with at least one of the figures, as set forth more completely in the claims.
[0008] In one aspect, there is provided a method for use by a system for digital rights management (“DRM”) of a plurality user devices. The method comprises receiving a user ID associated with a user for accessing the system; receiving a first device ID request from the user for registration of a first user device; generating a first unique identification number for the first user device; generating a first unique identification object based on a first DRM protocol, the first unique identification object including the first unique identification number; associating the user with the first user device, the first unique identification number and the first DRM protocol; receiving the user ID associated with the user for accessing the system; receiving a second device ID request from the user for registration of a second user device; generating a second unique identification number for the second user device; generating a second unique identification object based on a second DRM protocol, the second unique identification object including the second unique identification number, wherein the first DRM protocol and the second DRM protocol are incompatible; and associating the user with the second user device, the second unique identification number and the second DRM protocol.
[0009] In a further aspect, the method further comprises transmitting the unique identification object to the first user device. In an additional aspect, the method also comprises receiving the unique identification object from the first user device; receiving a first result of a function applied to the unique identification number; unlocking the unique identification object; applying the function to a content of the unique identification object to obtain a second result; comparing the first result with the second result; and approving access to the first user device if the comparing matches the first result with the second result. In one aspect, the first DRM protocol may be an Open Mobile Alliance Digital Rights Management (“OMADRM”) protocol and the second DRM protocol may be a Windows Media Digital Rights Management (“WMDRM”) protocol.
[0010] In yet another aspect, the first unique identification object is encrypted with a unique identification encryption key, and wherein unlocking the unique identification object includes using the unique identification encryption key. In one aspect, the method further comprises receiving a DRM license object request from the first user device; verifying the first user device; and transmitting a DRM license object to the first user device for unlocking the first unique identification object, where the first unique identification object is encrypted with a unique identification encryption key, and wherein DRM license object includes the unique identification encryption key, and where prior to receiving the DRM license object request, the method may comprise transmitting the unique identification object to the first user device; transmitting a rendezvous code to the first user device; and receiving the rendezvous code from the first user device, where the verifying includes confirming the rendezvous code.
[0011] Other features and advantages of the present invention will become more readily apparent to those of ordinary skill in the art after reviewing the following detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The features and advantages of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, wherein:
[0013] FIG. 1 illustrates a block diagram of a system for identifying a device implementing a DRM protocol, in accordance with one embodiment of the invention;
[0014] FIG. 2 illustrates a flowchart for performing a method for configuring a device implementing a DRM protocol, in accordance with one embodiment of the invention; and
[0015] FIG. 3 illustrates a flowchart for performing a method for validating a device implementing a DRM protocol, in accordance with one embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Although the invention is described with respect to specific embodiments, the principles of the invention, as defined by the claims appended herein, can obviously be applied beyond the specifically described embodiments of the invention described herein. Moreover, in the description of the present invention, certain details have been left out in order to not obscure the inventive aspects of the invention. The details left out are within the knowledge of a person of ordinary skill in the art. The drawings in the present application and their accompanying detailed description are directed to merely example embodiments of the invention. To maintain brevity, other embodiments of the invention which use the principles of the present invention are not specifically described in the present application and are not specifically illustrated by the present drawings. It should be borne in mind that, unless noted otherwise, like or corresponding elements among the figures may be indicated by like or corresponding reference numerals.
[0017] FIG. 1 illustrates a block diagram of rights server 100 for identifying user device 116 implementing a DRM protocol and authorizing the use of digital content protected by a DRM protocol. Rights server 100 includes controller 102 , receiver 104 , transmitter 106 , and unique identification database 110 (hereinafter “UID database 110 ”). Optionally, in one embodiment, rights server 100 also includes unique identification generator 108 (hereinafter “UID generator 108 ”). The unique identification can be, for example, a number or an alphanumeric string. As described below, such a unique identification can be advantageously used by rights server 100 to identify and authenticate user device 116 . Moreover, by determining the unique identification of each user device 116 communicating with rights server 100 , the user devices belonging to the same consumer or user can be advantageously determined. As such, more flexible licenses can be generated for the content, which can enable a consumer to conveniently share the content among her various devices to improve consumer experience.
[0018] As shown in FIG. 1 , controller 102 in rights server 100 is coupled to receiver 104 , transmitter 106 , UID generator 108 and UID database 110 . Controller 102 can be, for example, a microprocessor or a central processing unit (“CPU”). In one embodiment, receiver 104 and transmitter 106 can be implemented using a network interface, such as a Wi-Fi interface, a Bluetooth interface, an Ethernet interface, or any other type of network communication interface. As also shown in FIG. 1 , rights server 100 is in communication with user device 116 over a packet network, such as the Internet.
[0019] User device 116 in FIG. 1 includes controller 118 , transmitter 120 , receiver 122 , DRM module 124 , and memory 126 . Controller 118 can be a CPU, and transmitter 120 and receiver 122 can be implemented using a network interface, such as a Wi-Fi interface, a Bluetooth interface, an Ethernet interface, or any other type of network communication interface. User device 116 can be, for example, an electronic device, such as a personal computer, a personal digital assistant (“PDA”), an MP3 player, or a cellular telephone. Accordingly, user device 116 can be configured to receive and display various types of content, such as text, images, videos, or music.
[0020] As shown in FIG. 1 , rights server 100 is also in communication with native DRM server 130 over a packet network, such as the Internet. Native DRM server 130 includes controller 131 , transmitter 133 , receiver 132 , and unique identification rights objects generator 135 (hereinafter “UID rights object generator 135 ”), which includes UID encryption key database 136 . Optionally, in one embodiment, native DRM server 130 also includes unique identification generator 134 (hereinafter “UID generator 134 ”). Controller 131 can be a CPU, and transmitter 133 and receiver 132 can be implemented using a network interface, such as a Wi-Fi interface, a Bluetooth interface, an Ethernet interface, or any other type of network communication interface.
[0000] In one embodiment, the content is protected by a content provider using a DRM protocol, such as Open Mobile Alliance Digital Rights Management (“OMADRM”) or Windows Media Digital Rights Management (“WMDRM”).
[0021] To display a protected content, user device 116 may be required to separately acquire a license from rights server 100 . In one embodiment, the license can specify the allowable uses for the content and can include an encryption key for decrypting the content. DRM module 124 in user device 116 is configured to implement a DRM protocol for acquiring a license and for rendering the protected content to allow device 116 to use the content. DRM module 124 can be implemented, for example, in software or in hardware. In one embodiment, DRM module 124 can be configured to request a license when user device 116 initially attempts to use the content. For example, DRM module 124 can be configured to transmit a communication to rights server 100 , such as license request, when user device 116 initially attempts to use the protected content. As shown in FIG. 1 , rights server 100 can receive the license request at receiver 104 .
[0022] Turning to FIG. 2 , configuration method 200 for configuring user device 116 is described in conjunction with FIG. 1 , in accordance with one embodiment of the invention. As shown in FIG. 2 , configuration method 200 starts at step 202 , where user device 116 accesses rights server 100 using a user ID. Next, at step 204 , transmitter 120 of user device 116 transmits a device ID request for association with user device 116 to receiver 104 of rights server 100 . In one embodiment, the device ID request includes a native DRM ID parameter indicative of the DRM protocol utilized by user device 116 . In response, at step 206 , rights server 100 generates an ID object, and transmitter 106 of rights server 100 transmits the ID object to receiver 132 of native DRM server 130 . The ID object can be, for example, an extensible markup language (“XML”) document. Optionally, at step 206 , UID generator 108 of rights server 100 may also generate a unique ID number, and transmitter 106 may transmit the unique ID number to native DRM server 130 for user device 116 .
[0023] Next, at step 208 , controller 131 of native DRM server 130 utilizes the ID object to generate an ID object based on native DRM or the DRM supported by user device 116 , and further generate a rendezvous code for later use by user device 116 , as explained below. If native DRM server 130 does not receive a unique ID number from rights server 100 at step 206 , controller 131 of native DRM server 130 also generates a unique ID number, and transmitter 133 may transmit the unique ID number to rights server 100 . The ID object based on native DRM may include the unique ID number, which transmitter 133 transmits to rights server 100 . At step 210 , controller 102 of rights server 100 may store the unique ID received from native DRM server 130 in UID database 110 and associate user device 116 with the unique ID and the DRM protocol type of user device 116 in UID database 110 . For example, as shown in FIG. 1 , for the first user device, user and/or user ID is associated with the first user device (or Device_ 1 ) and the first DRM protocol type (or DRM 1 ), and for the second user device, user and/or user ID is associated with the second user device (or Device_ 2 ) and the second DRM protocol type (or DRM 2 ). Therefore, unlike the conventional systems, an embodiment of the present invention provides a system, where multiple non-compatible DRMs can be supported, and even more, multiple non-compatible DRMs can be used by a single user using a number of different user devices. For example, a user may have two user devices each using a different DRM protocol family, which are incompatible, and rights server 100 of the present invention provides UID database 110 to associate the user with two different user devices, where each device utilizes a different DRM protocol.
[0024] Continuing with step 212 , transmitter 106 of rights server 100 transmits the ID object for the native DRM and the rendezvous code to user device 116 . Next, at step 214 , controller 118 of user device 116 generates a native DRM license object request including the rendezvous code, which transmitter 120 of user device 100 transmits directly to native DRM server 130 , or indirectly, such as through rights server 100 to native DRM server 130 . Upon receipt of native DRM license object request including the rendezvous code by native DRM server 130 at step 216 , controller 131 of native DRM server 130 checks the rendezvous code to determine validity, and if valid, controller 131 of native DRM server 130 generates a license rights object, and transmitter 133 transmits the license rights object to user device 116 directly or indirectly. The license rights object provides a key needed for unlocking or decrypting the ID object for native DRM. At step 218 , receiver 122 of user device 116 receives the license rights object and stores the license rights object in memory 126 for unlocking the ID object for native DRM.
[0025] FIG. 3 illustrates validation method 300 for validating user device 116 , which is described in conjunction with FIG. 1 , in accordance with one embodiment of the invention. At step 302 , controller 118 of user device 116 generates a license use request, and transmitter 120 of user device 116 transmits the license use request to rights server 100 . Upon receipt of the license use request by receiver 104 of rights server 100 , at step 304 , controller 102 of rights server 100 generates a nonce challenge, and transmitter 106 of rights server 100 transmits the nonce challenge to user device 116 . Upon receipt of the nonce challenge by receiver 122 of user device 116 , at step 306 , controller 118 of user device 116 unlocks the ID object for native DRM using the license rights object to access the contents of the ID object for native DRM. Next, controller 118 of user device 116 calculates a pre-determined function, such as a hash function, based on the nonce challenge and the contents of the ID object for native DRM to generate a user device function result. For example, in one embodiment, the nonce challenge may be XORed with the contents of the ID object for native DRM. Further, at step 306 , transmitter 120 of user device 116 transmits the ID object for native DRM and user device function result to rights server 100 .
[0026] At step 308 , upon receipt of the ID object for native DRM and user device function result by receiver 104 of rights server 100 , transmitter 106 of rights server 100 transmits the ID object for native DRM to native DRM server 130 . At step 310 , upon receipt of the ID object for native DRM by receiver 132 of native DRM server 130 , controller 131 of native DRM server 130 unlocks the ID object for native DRM using the license rights object to access the contents of the ID object for native DRM, and transmitter 133 of native DRM server 130 transmits the contents of the ID object for native DRM to rights server 100 .
[0027] At step 312 , upon receipt of the contents of the ID object for native DRM by receiver 102 of rights server 100 , controller 102 of rights server 100 calculates the pre-determined function, such as a hash function, based on the nonce challenge and the contents of the ID object for native DRM to generate a rights server function result. For example, in one embodiment, the nonce challenge may be XORed with the contents of the ID object for native DRM. Further, at step 314 , controller 102 of rights server 100 compares the user device function result and the rights server function result to validate access by user device 116 . At step 316 , if the user device function result is the same as the rights server function result, access by user device 116 is granted, and conversely, if the user device function result does not match the rights server function result, access by user device 116 is denied.
[0028] From the above description of the invention it is manifest that various techniques can be used for implementing the concepts of the present invention without departing from its scope. Moreover, while the invention has been described with specific reference to certain embodiments, a person of ordinary skill in the art would recognize that changes can be made in form and detail without departing from the spirit and the scope of the invention. For example, it is contemplated that the circuitry disclosed herein can be implemented in software, or vice versa. The described embodiments are to be considered in all respects as illustrative and not restrictive. It should also be understood that the invention is not limited to the particular embodiments described herein, but is capable of many rearrangements, modifications, and substitutions without departing from the scope of the invention. | A method comprises receiving a first device ID request from user for registration of a first user device; generating a first unique identification number for the first user device; generating a first unique identification object based on a first DRM protocol, the first unique identification object including the first unique identification number; associating the user with the first user device, the first unique identification number and the first DRM protocol; receiving a second device ID request from user for registration of a second user device; generating a second unique identification number for the second user device; generating a second unique identification object based on a second DRM protocol, the second unique identification object including the second unique identification number, wherein the first DRM protocol and the second DRM protocol are incompatible; and associating the user with the second user device, the second unique identification number and the second DRM protocol. | 6 |
BACKGROUND OF THE INVENTION
A relatively small apparatus employing a process for the aerobic treatment of contaminated liquids, has been the subject matter of many proposals, particularly in light of increasingly restrictive specifications for acceptable pollution control in the effluent from domestic and industrial sewage treatment apparatuses. The difficulty lies in achieving small-scale sewage treatment apparatuses, since they are frequently overwhelmed by sudden inflows of water or other liquids which are beyond the capacity of the system to handle. Of course, the systems must be designed for a given upper limit of fluid treatment in mind, but this should be as small as reasonably possible, otherwise the system is built to overcapacity. The difficulty comes on those rare occasions (because of coincidence of several events), when there is a sudden inflow of water for treatment by the process and apparatus which is beyond its normal capacity. In this event the prior art systems become overtaxed and require special reconditioning for further operation.
Many small-scale sewage treatment apparatuses for domestic and industrial use, contemplate the fabricating of the apparatus at the proposed site of use. This requires a crew of skilled assemblers and fabricators, entailing added expense in the way of installation, material shipment, etc.
In still other domestic and industrial water or other liquid treatment systems, there is no ready means for providing an efficient system of sensors whereby the operation can be continuously self-monitored so that in the event any portion of the system requires bypassing or cleaning for more efficient operation, such adjustments in flow and self-cleaning can be effected.
The overall technical problem which has thus far challenged the art, is the constructing and use of a modular type system which can be standardized and enlarged or contracted in capacity and fabricated from standard corrugated, curvilinear cross section pipe which is compartmentalized into surge tank, aeration chamber, clarifier, rapid sand filter, clear well and chlorinator tank, with the respective operations so interrelated that at least a portion of each discrete subsection is always in condition for operation, the overall system is continuously self-monitored, and fluid is thus routed for the most efficient operation.
In the aerobic treatment of contaminated liquid, provision must be made for the efficient mechanical and chemical dissolution of solid waste product which needs to be aerobically reduced and removed from the liquid phase portion. Removal occurs by way of filtration as well as chemical reduction, in a series of steps which are calculated to ultimately remove the contaminants from the liquid treated. Since the treatment scheme of contaminant removal must be geared to both variable flow and variable degree of contamination, the apparatus must be either complexly constructed or face an inevitable self-fouling as the liquid passes through the successive steps of aerobic treatment.
SUMMARY OF THE INVENTION
It is an object of the present invention to construct a multi-chambered aerobic treatment apparatus utilizing a curvilinear corrugated pipe having an internal lamination which renders it relatively inert to the liquid being treated.
Another object of the present invention is to provide a multiinternally-chambered corrugated pipe which is adapted for treating contaminated liquids by an aerobic process and which is modular in operation, i.e., one which can be readily expanded to meet additional requirements in the way of volume of liquid for treatment.
Another object of the present invention is to provide a system and apparatus for aerobic treatment of contaminated liquid in which each portion of the system is so monitored that if any portion should become disabled or inefficient, the fluid can be appropriately rerouted to a relatively less contaminated portion of the apparatus, to maintain the efficiency of the system.
Another object of the present invention is to provide either a gravity flow system or positive liquid displacement system in which liquid is successively treated through aeration, clarification, filtration, settling and chlorination techniques to remove effectively the contaminants from the liquid and which can be discharged within sewage treatment standards of both state and federal level.
An overall object of the present invention is to provide a system which is at all times ready to receive available inflow of liquid and which can be readily adjusted to unexpected surges of inflow and not become disabled thereby. Where unexpected surges of inflow occur, the system adjusts itself even if it should be temporarily beyond the capacity of the system to treat such flow. The system can then recoup and produce an efficient treatment of the liquid without dumping it into the environment.
An overall object of the present invention is to produce an inexpensive, self-monitoring system and apparatus for the aerobic treatment of contaminated liquids which can be prefabricated, transported overland to the point of use and there installed at least partially below ground in an excavation which is readily prepared for such purpose. As a result the system is constructable at a central area to realize maximum efficiencies and adjustments in preparation for a proposed use.
Other objects and features of the present invention will become apparent from a consideration of the following description which proceeds with reference to the accompanying drawings.
DRAWINGS
FIG. 1 is an isometric external detail view of a sewage treatment facility, with a portion of the external walls broken away to illustrate internal compartments of the apparatus;
FIG. 2 is a sectional detail view taken on line 2--2 in FIG. 1;
FIG. 3 is a longitudinal sectional view taken on line 3--3 of FIG. 1;
FIGS. 4, 5, 6, 7 are lateral cross section views taken on the respective section lines 4--4, 5--5, 6--6, and 7--7 in FIG. 3;
FIG. 8 is a schematic view of one of the embodiments of the process in which the liquid is caused to traverse through the apparatus primarily by gravity flow;
FIG. 9 is a schematic view of a second embodiment of the invention which is similar to that of FIG. 8 but illustrates how the liquid intended for aerobic treatment is transferred through the system by means of positive displacement pumps;
FIG. 10 is a detail cross sectional view showing in enlarged proportions the details of the skimmer, located in the clarifier chamber; and
FIGS. 11, 12, 13, 14 are cross sectional views of the various curvilinear shapes of the corrugated pipe which is adapted for compartmentalizing to form the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, an elongated, circular cross section corrugated pipe designated generally by reference numeral 10, having end walls 11, 12 is subdivided by means of transverse walls 14, 16, 18, 20, 22 into various compartments which are designated surge chamber 24, aeration chamber 26, clarifier chamber 28, rapid sand filter chambers 30, clear well 32, and chlorination chambers 34.
The liquid which is to be aerobically treated for the removal of contamination, is introduced to the system through an inlet 36 and the clear processed fluid is discharged to the environment through an outlet opening 40 at end 42.
Incoming flow, in one embodiment, is passed through a comminuter 44 (FIGS. 2,3) which is intended to break up the solid content into finer particles. The incoming contaminated fluid is indicated by arrow 46 (FIGS. 2,3). Within surge tank 24 are two sensors, one a low level sensor 48, and the other a high liquid level sensor 50. When liquid is below the level of the sensor 48, pump 52 (FIG. 8), transferring the liquid from surge tank 24, is turned off. When liquid level is above sensor 50, pump 52 is turned on, supplying air under pressure through line 54 and inducting fluid through line 56, having an outlet 58 leading to aeration chamber 26. In this manner, while the air pump 52 is running, liquid is withdrawn from surge tank 24 and transferred to aeration tank 26.
The reason for having spaced sensors 48,50 is to keep the unit from continuously running. In most instances, the rate of inflow of liquid is maintained between the level of the sensor 50 and the sensor 48. Should the inflow of liquid be beyond the capacity of the air pump to transfer liquid, and the liquid rises above sensor 50, there is an overflow opening 59 (FIG. 3) which allows liquid to gravity-spill into the aeration chamber 26. Sludge which settles to the bottom of the surge tank 24 is periodically removed through access opening 62.
It is possible to eliminate the air pump transfer and allow the liquid to flow completely by gravity from the surge tank 24 to the aeration tank 26 through opening 57.
Also, as indicated in FIG. 9, the surge tank can be omitted, and liquid intended to be treated can be introduced directly into the aeration chamber.
The particular selected use depends upon evaluation of the character of the liquid being treated. In the event there is characteristically high content of solids, it is advisable to include a surge tank. A surge tank is also advisable where there is considerable variability in rate of inlet flow.
Considering next the aeration tank 26, there is a number of diffuser lines 61 which extend below the level 63 of the liquid (FIG. 3) and which include a number of air outlet ports 64 which provide a continuous flow of entrained air bubbles diffused through the entire liquid mass and thereby achieving aerobic transformation of the aeration chamber contents by chemical dissolution of the pollutants. As shown in FIGS. 8,9 air for the diffuser line 60 is supplied from an air inlet source 68 and can be operatively interconnected to air pump 52 or air valve. The aeration chamber 26 has an outlet 80, with shield 82 over the outlet, to prevent splashing, so that the fully aerated liquid can next pass through partition 16 into a clarifier chamber 28.
Within clarifier chamber 28 (FIG. 5) is a skimmer (5) each designated generally by reference numeral 84 consisting of a shallow pan 86 (FIG. 10) with notches 88 so that at the liquid level 90 (FIG. 10) the surface sludge and other impurities, flow in the direction of the arrows 92 into the pan and descent downwardly through flexible line 94, traveling in the direction of the arrows 96 in a generally downward direction and then move upwardly in the direction of the arrows 98 and through line 100 returning to the aeration chamber through line 102 (FIG. 9) and discharging into the aeration chamber 26 through outlet openings 104 (FIGS. 8,9). By returning the floatable sludge in this manner, there is opportunity for additional aerobic treatment which further reduces the sludge, causing it to decompose.
The surface sludge is forced to return by means of an air line 108 controlled by valve 110. The air line 108 leads through an elbow 114 and line 116 and the inflow of air indicated by arrow 118 causes the solid and liquid phase material collected within the shallow pan to be drawn upwardly in the manner indicated by arrow 120 and thence is returned to the aeration chamber.
In order to reduce the occurrence of froth within the aeration chamber, there are a plurality of spray outlets 130 which direct spray 132 downwardly against the surface 63 of the fluid within the aeration chamber 26, thereby dispersing foam as it occurs.
The fluid for producing the spray is derived from fluid within clarifier chamber 28 through line 150 from froth pump 152 submerged in clarifier chamber 28.
The aeration chamber also receives a return of settled sludge at the base 180 of clarifier chamber 28 (FIG. 5). By means of an induction line 182 which is used to induct the sludge through opening 184, the sludge collects between the inclined surfaces 185 (FIG. 5) of an insert fitted within the circular cross section of clarifier chamber 28 and the curvilinear interior surface of the pipe 10. The sludge is drawn upwardly within line 182 by means of an air line 186 which injects air at 188, thus drawing the sludge upwardly. The sludge return line has an outlet 190 which returns the solid phase, or thicker liquid phase, sludge to the surge chamber 24 where it undergoes further decomposition under aerobic digestion.
From the clarifier compartment 28, liquid travels either in one direction or the other (FIG. 8) through branched outlet line 200, the direction or branch depending upon the position of the movable gate 202. For example, with the gate 202 in the full-line position shown in FIG. 8, out-flowing liquid moves in the direction of the arrow 204, and with the gate in the dotted-line position of FIG. 8, out-flowing liquid moves in the direction of the arrow 206. Assuming that the gate is in the full-line position and the arrow 204 represents the direction of movement of a liquid, such liquid enters rapid sand filter 208 (FIG. 6) as opposed to rapid sand filter 210.
Assuming that rapid sand filter 208 is the functioning filter chamber, and assuming further that liquid level is not above the level 212 so as to energize the sensor 214, the liquid will pass through filter sand bed 216, perforated support plate 218, and thence into chamber 220. From chamber 220 the liquid is transferred through conductor 222 in a direction of the arrows 224 and into a clear well 32. Referring to FIG. 3, a vertical line 230 having an opening 232 within the lower chamber 220 of the rapid sand filter and a vertical transfer line 234, includes a control valve 236. When the supernatant liquid in the rapid sand filter is at or above the level of the valve 236 and outlet opening 238, the filtered liquid can transfer into the clear well 32. From the clear well, liquid transfers by gravity through opening 240 of partition 22 and into a chlorinator chamber 34, where the flow is then chlorinated from chlorinating tank 241 having supply line 243 through which crystals or liquid is passed into the chlorinating chamber 34. Either liquid, gaseous, chlorine or chlorine-generating solid phase crystals are usable. The chlorinated liquid then passes up and over a series of baffles (FIG. 7) 246, 248, 250, and then exits through V-shaped cross section outlet 40.
While the rapid sand filter 208 is being utilized, the rapid sand filter 210 is in a standby condition. Referring to FIGS. 6, 9, when the liquid level in 208 or 210 reaches a height sufficient to contact probe or sensor 214 or 214A, fluid flow to that rapid sand filter chamber is terminated by means of a remotely operable either-or switch 260. The switch 260, acting through conductors 262, 264 operates a relay (not shown) associated with selector gate valve or gate 202, immediately shutting off flow to the clogged filter as sensed by the sensor 214 or 214A therein, and operation continues as before but with flow shunted to the unclogged filter by positioning the gate 202. Sand filter bed selection can take place at any time during day or night operation. In another operation by the either-or switch 260, simultaneously with sensing by the sensors 214, 214A, one or the other of the backwash pumps 268 or 270, is "armed" by the either-or switch. Thus, should the rapid sand filter 208 at the left-hand side of FIG. 6 be clogged so that its probe 214 is energized, then the backwash motor 270 associated with it will be simultaneously armed by the either-or switch 260 so that when the timer 284 signals at the appointed time and addresses both backwash motors 268,270, only the motor preconditioned by switch 260 will be operated. Generally, the timer is set for a very low period of liquid treatment usage, as, for example, the early morning hours, 2:00 or 2:30 a.m., so that the backwash will take place without interfering with the normal operation. It should be noted that the timer 284 as indicated in FIG. 9 will not permit a backwash to occur should the liquid level in the aeration chamber be too high as sensed by sensor 290, because the aeration chamber 26 is in no position to receive the backwash.
During backwash, the energized backwash motor, as, for example, 270, will induct fluid from the clear well 32 through line 294. Pump 270 closes valve 236 and passes fluid through lines 234,230 and out opening 232 and chamber 220 (FIG. 6).
Counterflow of fluid upwardly through the sand filter 216 removes the contaminants and, together with the supernatant clogged fluid, represented by 207, causes the backwash to return to the aerator chamber 26.
Neither motor 268, 270 can be energized if there is insufficient water in the clear well 226 as determined by probe 302 having connecting lines 304, 306 (FIG. 8) to the motors 268,270.
Comparing FIGS. 8,9: FIG. 8 represents a system operable primarily by gravity, and FIG. 9 represents the system of FIG. 8 modified slightly to be operated by positive displacement pumps. The two different embodiments differ also in that the timer 284 of the gravity system in FIG. 8 is not responsive to the liquid level in the aeration chamber whereas it is, in FIG. 9, through line 285.
Also, the pumps 318,320 are used to transfer fluid from the clarifier chamber to the rapid sand filters 208, 210 and valve operated cross-over lines 340,342 are used in the event that either of the pumps 318,320 fail. Likewise, between backwash pumps 268,270 in the embodiment of FIG. 9 are cross-over lines 350, 352 in the event that either of these pumps fail, a single pump can be used to backwash through either rapid sand filter 210,208.
In the event there is emergency flooding of the system, ball check valve 360 is unseated and liquid is transferred from the aeration chamber 26, to rapid sand filter 30 (FIG. 3) through line 361 and from that chamber liquid passes on gravity through chamber 30 to clear well through line 234. From clear well 32 the liquid goes through opening 240 to chamber 34, where it is passed out of the system through opening 40. When the liquid level in the rapid sand filter rises to the point where it spills over a V-trough 380, liquid is counterflowed to aeration chamber 26. The trough and connecting lines 382 are inclined so that the liquid content flows backwardly, i.e., from the discharge end of the apparatus to the charging end of the apparatus. The pipe sections 382 receiving fluid (FIG. 2) discharge through open ends 384 returning such excess fluid to the aeration chamber 26.
Referring next to FIGS. 11-14, there is demonstrated in FIG. 11 that the pipe can either be circular, as shown in 400, or as an inverted pipe arch (FIG. 12) 402, or as an inverted underpass configuration 404 (FIG. 13), or as an oval configuration (FIG. 14), 406.
Each of these different shapes is contemplated by the present invention and the particular selection is a matter of design preference, taking into account the terrain in which the system is installed, the character of the liquid treated, and the type of solids which will probably be encountered.
All of the suggested shapes are within the contemplation of the present invention and, although these are illustrative, they are by no means restrictive of the range of variability of cross section shape, the general requirement being only that a curvilinear cross section is greatly preferred to the rectilinear shape. The reason for preferring the curvilinear cross section is that such pipe shapes are more readily available, and are better adapted to the fabrication of the overall system and apparatus as described.
OPERATION
In operation, a liquid or semi-liquid, such as domestic sewage, is supplied to the apparatus 10 through inlet 36. A variable inflow through line 36 is expected, and the operation of the apparatus 10 is so designed as to accommodate this variability of inflow. The inflow is at first into a surge tank 24. The incoming fluid is first passed through a comminuter 44 to insure that solids content are broken up into as fine particles as possible so as to enhance the aerobic digestion of the organic components within the system.
In the surge tank 24, the heavier settleable solid phase contaminants are separated from the liquids which pass either by gravity or by pump, from chamber 24 to the aerator chamber 26.
There is expected some variability in height of fluid within surge tank 24. The two probes in surge tank 48, 50 are used to monitor the pump 52 which transfers the fluid from the surge chamber to the aeration chamber 26. The two probes, 48, 50, provide that pump operation does not occur at levels below the level of probe 48, but the system does work after the liquid has reached the level of probe 50, and continues operation until such level falls to the level of probe 48.
Once the liquid is in the aeration chamber 26, it is subjected to a stream of aeration bubbles emanating from openings 64, these air bubbles being utilized to traverse through the liquid and effect aerobic conversion of the solid content of the sewage.
Air is supplied through the diffusers or outlet opening 64 on a continuous basis through air supply line 68. Foam within aeration chamber is suppressed by means of a spray of liquid 132 from the clarifier chamber 28. Continuous downward sprays indicated by reference numeral 132 against the upper surface 63 effectively keeps the foam to a minimum. Foam is undesirable because it could clog the chamber.
Aeration chamber 26 receives a return or counterflow of surface sludge which collects at the surface 90 within the clarifier chamber by means of a pair of skimmers 84 (FIG. 10), each consisting of a shallow pan 88 which receives the surface sludge therein, and is maintained at the surface by means of flotation material 89 at undersurface of the pan 86. The collected sludge follows the course of arrows 96, 98, 120 (FIG. 10), is drawn upwardly through line 100 because of inducted air flow from line 108. The surface sludge is returned through line 100 and outlet opening 104 (FIG. 3). The returned sludge is aerated for additional aerobic digestion.
Also within the clarifier chamber, is a sludge return which extends to the bottom of the clarifier chamber 28 and has an inlet opening 184, such settled sludge being returned to the aeration chamber through line 182 through outlet opening 190 (FIG. 9). The bottom sludge, as indicated in FIG. 5, tends to collect within the narrowing cross section formed at the intersection between the angular inset 186. The bottom sludge concentrates in the pocket formed between the curvilinear sidewall of the pipe and the angled base 186.
In the manner described, both the surface sludge and settled sludge are recycled to the aeration chamber from the clarifier. The liquid in the clarifier chamber is then fed either by gravity or by pump 318, 320 to one or the other of rapid sand filter 208, 210. The particular sand filter 208, 210 which is used is determined by the either-or remote selector 260.
It is an important aspect of the present invention that one of the sand filters 208, 210 is backwashed and ready for operation while the other is being used so the two filters alternate in usage, the one being backwashed or ready to be backwashed while the other is in use.
Assuming that the gate 202 is in the full line position shown in FIG. 8, liquid flows by gravity from clarifier chamber 28 to rapid sand filter 208. This continues until the rapid sand filter becomes clogged, at which time the fluid level rises and sensor 214 (FIG. 6) is contacted, at which time either-or control 260 is operated to effect through conductor 262, energization of a solenoid (not shown) which moves selector gate 202 from the full line position to the dotted line position, preventing further flow through the clogged filter 208, and therafter further flow occurs through the rapid sand filter 210. At this point the either-or control 260 "arms" pump 270 so that when timer 284 which is set for some period of light use of the apparatus, as, for example, an early morning hour, the timer 284 will, when reaching the appointed hour, address both backwash motors 268,270, but will operate only the "armed" motor 270, causing a flow of fluid from the clear well 226 by motor 270, backwashing through the rapid sand filter 208, moving upwardly through the perforated support 218 and the sand bed 216, and removing any collected solids in the sand bed 216 together with the supernatant fluid 207 and causing it to return to the aeration chamber through backwash line vee 380, line 382, outlet 384 (FIG. 9). Backwashing can occur only if there is sufficient fluid in the clear well as determined by the liquid level sensor 302 in the clear well 226.
Referring to FIGS. 8, 9, FIG. 8 being the gravity system and FIG. 9 being the positive pump displacement system, the timer can only operate to produce backwash if there is an acceptably low level of fluid in the aeration chamber. For example, if the aeration chamber level is very high, as sensed by the sensor 290, the timer will not become operative to cause a backwash because in the event of a backwash this would overfill the aeration chamber. The backwash cycle is thus skipped. This is not particularly objectionable since it is likely that an unbackwashed sand filter can continue to operate as much as a day or two at a time, and extending the cycle an additional day is generally not critical.
From the rapid sand filter 208, 210, liquid passes either by pump or by gravity to a clear well 226, and thence to a chlorination chamber 34. After being baffled in opposite vertical direction by a series of baffles 246, 248, 250, chlorinated essentially decontaminated liquid is discharged through opening 40.
The operation as described, together with the apparatus as described, is essentially a continuous process. The system is self-regulating in that sensors determine: which one of the sand filters 208, 210 shall be used; when liquid transfer shall occur from one chamber to the next; and, whether liquid transfer ought to occur either as a flow or as a counter-flow according to the conditions of the liquid level in the respective chambers, as well as their degree of contamination or uncontamination.
Should the level of fluid be extensively high downstream, i.e., within the rapid sand filter as compared with the upstream surge chamber or aeration chamber, liquid is transferred as a counterflow through V-troughs 380 and connecting pipes 382 which carry the fluid back so that all portions of the system are essentially equally loaded and there is not excessive outflow of essentially untreated liquid.
Should the level of liquid in the aerator chamber 26 become excessively high, the liquid can flow by gravity through line 361 and check valve 362 directly into the sand filter chamber where the fluid can pass by gravity through line 234 into clarifier chamber 32; thence to chlorinator chamber 33 and be discharged through line 40 to the environment. Thus, the entire contents of the system can be discharged by gravity.
The system can be used either by gravity flow supplemented by only two pumps, i.e., backwash pumps in the manner indicated in the embodiment of FIG. 8; or positive displacement pumps can be used throughout the system, as indicated in FIG. 9, relying upon gravity only in the event of a total power failure.
In either event, the systems can be employed with curvilinear cross section pipe of various shapes, including but not limited to, those in the embodiments of FIGS. 11, 12, 13, 14.
An important feature of the present invention is that the device can be fully constructed and transported overland by truck to the point of use where a partial excavation is made, and the unit lowered in place. A protective shelter is frequently constructed around the system so that those charged with maintenance can give year-around service to the device including the removal of any solid contaminants, checking water levels, water flows, replacing pumps, checking the degree of purity of the effluent, and the degree of flow and degree of impurity in the incoming fluid intended to be treated. Partial submerging of the apparatus in the ground is advantageous, since it will keep the liquid phase from freezing, and obviate having to heat the system. Moreover, partially excavating and filling the excavation with the major part of the curvilinear cross section pipe, provides an even, sustaining outer support for the liquid contents of the pipe which can have the particular curvilinear cross section pipe best adapted for the particular fluid and degree of contaminants to be carried by the pipe.
Once in place, the system works in a remarkably efficient manner and requires very little, if any, servicing or overseeing. Moreover, should there by sudden surges or overtaxing of the system, liquid is simply shunted through the system (without purifying the liquid, of course), but at the same time without rendering the system inoperative to the next succeeding inflows, which are treated in the usual manner. Thus, excessive loading of the system, while objectionable in itself, does not render the system totally disabled as frequently happens in prior art devices. Instead, the system simply shunts the fluid out without treating a portion thereof, but does treat the remainder, which is within the capacity of the system, in the usual manner. This is an important feature of the present invention, since there are freakish, chancy excess flows which, however undesirable, are tolerated by the system and without rendering the system inoperative.
The corrugated metal is the preferred material of construction, but it should be understood that concrete pipe is also usable and acceptable for some applications.
An important feature of the present invention is that the total handling of the contaminated liquid through the apparatus occurs with a limited number of pumps which therefore entails less cost because of reduced requirements for maintenance and power requirements.
Because of a relatively few number of pumps and motors, the system can be expected to operate for long periods of time without service requirement, and even in the event that there is a total power failure which renders the pumps and motors inoperative, the unit is not disabled but can continue to operate by shunting the liquid entirely through the system by gravity.
All of the pumps which are used are externally located to avoid the corrosive environment frequently associated with contaminated liquid treatment. Since the pumps are externally located, they are readily accessible and are standard pumps operated in conventional manner by commercially available motors.
Emergency overflows are provided through the system so that in no event can the system be permanently disabled by any unexpected inrush of fluid in amounts for which the apparatus was not designed and is not within its normal capacity to manage.
Although the invention has been described in connection with a few selected example embodiments, it is to be understood that these are illustrative of the invention and are by no means restrictive thereof. It is reasonably to be expected that those skilled in this art can make numerous revisions and adaptations of the invention, and it is intended that such revisions and adaptations will be included within the scope of the following claims as equivalents of the invention. | A waste treatment apparatus operated either by gravity or by positive displacement pump in which a variable inflow of contaminated liquid is aerated, clarified, and filtered. The filtered liquid is used to backwash one of at least a pair of rapid sand filters, while the other rapid sand filter is being utilized. The alternating cycle of backwashing and filtering by the respective rapid sand filters, all of which is integrated with overall filtering operation, insures that at least one filter is fully operative at any time.
The apparatus is adapted for variable inflow and can adapt to such unfavorable exigencies as overtaxing inflow and clogging at the rapid sand filter or at an earlier stage of contaminated liquid treatment. Sensors are located suitably throughout the apparatus to adjust the system to overflow conditions or clogged conditions, and the flows can be redirected through a preferred stage. The system is self-regulated and is responsive to critical conditions such as too little water for treatment, excessive inflow of contaminated liquid for treatment, clogged condition in the filters, clear well, etc.
The apparatus for treating the contaminated liquid is constructed from an elongated, curvilinear cross section pipe which is cut to length and compartmentalized interiorly for the various steps of aerating, clarifying, filtering, and chlorinating. Such pipe is readily available and is adapted for containing contaminated liquid and treatment thereof, and for subsurface installation. | 2 |
BACKGROUND OF THE INVENTION
This invention relates generally to paper making machines of the Fourdrinier type wherein the paper is formed on an essentially horizontal run of forming wire traveling from the breast roll to the couch roll. The invention is more specifically directed to a recent trend in Fourdrinier machines wherein a second wire is mounted on top of the primary wire downstream from the breast roll so that liquid is expressed from the stock on the primary wire through both wires. This type of combined machine is now commonly referred to as a "top former" machine, and as background for the description of the present invention, the best example of a top former machine is shown in Creagan et al U.S. Pat. No. 4,532,008 issued July 30, 1985 to the assignee of the present invention.
SUMMARY OF THE INVENTION
This invention has as a primary object the provision of test apparatus for the purpose of enabling a paper mill to determine the extent to which the performance and/or the product of an existing Fourdrinier paper machine in the mill will be improved by its conversion into a top former machine.
More specifically, the invention provides what is in effect a fractional version of top forming apparatus which can be readily combined with an existing Fourdrinier machine in such manner that a minor portion of the forming width of the machine will be converted to top forming operation. In other words, the invention makes it possible to produce, on an existing Fourdrinier machine, a sheet of which a small integral portion, preferably adjacent one edge thereof, is formed by drainage through both the primary wire and a top wire, while the remainder of the sheet continues to be produced in the same manner as before the top wire testing.
A particular objective and accomplishment of the invention is to provide such test apparatus which can be quickly and easily combined with an existing Fourdrinier machine without in any way modifying the existing structure or otherwise interfering with the conventional operation of the machine. This result is accomplished by providing the apparatus of the invention as a self-contained unit which can be inserted into an existing Fourdrinier machine from one side thereof without interrupting or otherwise interfering with the regular operation of the other parts thereof.
The manner and means by which these objects and advantages are achieved are pointed out below in connection with the description of the preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view showing a mobile top former unit in accordance with the invention in combination with an existing Fourdrinier machine;
FIG. 2 is an elevation of the unit of the invention viewed looking from right to left as indicated by the line 2--2 in FIG. 1;
FIG. 3 is a plan view of the apparatus of FIGS. 1-2 as indicated by the line 3--3 in FIG. 1;
FIG. 4 is a fragmentary section on the line 4--4 in FIG. 1;
FIG. 5 is a fragmentary section on the line 5--5 of FIG. 1;
FIG. 6 is a fragmentary view, on a larger scale, of a portion of FIG. 1;
FIG. 7 is a fragmentary section, on a different scale, on the line 7--7 of FIG. 1 and FIG. 6;
FIG. 8 is a fragmentary view, on a larger scale, of a portion of FIG. 1; and
FIG. 9 is a diagrammatic side view illustrating the operation of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows in phantom outline the basic elements of the existing Fourdrinier paper machine with which the invention is combined, including main frame means designated generally as 10 which support the breast roll 11, suction couch roll 12, and the usual wire return rolls for supporting the primary forming wire 13. A headbox 15 at one end of the frame 10 delivers a flow of stock at the breast roll 11 onto the upstream end of the horizontal forming run of wire 13 for drainage through the wire to effect formation of a sheet.
All of the operating parts of the apparatus provided in accordance with the present invention are supported in a supplemental frame designated generally at 20. The primary operating part is a relatively narrow endless wire loop 22 of substantially less length than the primary wire 13, satisfactory results in the testing of the invention having been obtained with this top wire only 16 inches in width as compared with primary wires 13 which may be several hundred inches in width.
The supplemental frame 20 is supported on a mounting by which it can be moved laterally of the front side of the main frame 10 into and out of overlying relation with a portion of the primary wire 13 adjacent the front side of the paper machine. Stand means for this purpose comprise a pair of carriages 25 interconnected by one or more cross braces 26, and each carriage is supported for rolling movement to and away from the main frame 10 on a track assembly 30 firmly secured to the floor and preferably also to the same front sole plate 31 as the frame 10. Lock screws 32' hold each carriage 25 in fixed position with respect to the frame 10, with the aid of hook clamps 33 mounted on at least one of the track assemblies 30.
Each carriage 30 includes a vertical hollow column 34, preferably of square section, in which a vertical column 35 is telescoped for vertical adjustment, relatively fine adjustment being provided by bolts 36 connecting complementary angle brackets 37 and 38 on the columns 34 and 35 respectively. A cantilevered arm 40 projects at right angles from the upper end of each column 35 to serve as direct support for the supplemental frame 20. A counterweight 42 on the opposite side of each carriage 30 from arms 40 contributes to stability of the apparatus as a whole.
As best seen in FIG. 3, the supplemental frame 20 comprises a pair of beams 44 of rectangular section which extend the full length of the supplemental frame and are secured together by cross beams 45 at spaced locations along their length. The beams 44 rest on and are secured to the cantilever arms 40, and they should be of sufficient length to position the top wire 22 in overlying relation with the primary wire 13 without interference with any part of the existing machine. For a form of the invention wherein the wire 22 is 16 inches wide as stated above, this result is readily accomplished if the arms 44 are approximately 80 inches in length, and the preferred lateral location of wire 16 is with its outer edge aligned with the front edge of wire 13.
The top wire 22 is supported on supplemental frame 20 by five rolls, a drive roll 50 having its drive motor 51 mounted on frame 20, a tensioning roll 52 mounted for movement lengthwise of frame 20, a guide roll 53, and a pair of vertically adjustable rolls 55 and 56 which support the generally horizontal run of wire 22 that cooperates with the forming run of the primary wire 13.
The roll 55 at the upstream end of this run has its journals mounted on a pair of arms 57 pivotally supported at one end in a pair of hangers 58 depending from the beams 44. The other end of each of these arms 57 is adjustably supported by a jack assembly 60 from the upstream end of the beam 40 thereabove, this pair of jack assemblies having a common operating shaft 61 provided with an operating hand wheel 62. A similar jack assembly 65 provides for adjustment of the bearings for each journal of the roll 56 on a hanger 67 depending from near the downstream end of each beam 40, and this pair of jacks also has a common operating shaft and handle wheel 68.
Vertical adjustment of the rolls 55 and 56 on frame 20 regulates the maximum vertical spacing between the forming run of the top wire 22 above the primary wire 13 for a specific vertical position of frame 22 on stand 25. In addition, two deflectors for supporting the forming run of wire 22 are mounted for vertical and angular adjustment on the supplemental frame 20, and another two deflectors are suspended from the supplemental frame 20 in supporting relation with the forming run of the primary wire 13 and in alternating relation lengthwise of the machine with the deflectors for the top wire.
The deflectors 70 and 71 for the bottom wire are mounted on top of the front and back sides of an open box-like housing 72 which extends under the wire 13 as best seen in FIG. 7. This deflector assembly is supported by a right angled hanger arm 75 which depends from the front beam 40. A bracket 76 on the back side of the lower end of this arm provides a pivotal mounting 77 for an arm 78 projecting from the front of the deflector housing 72.
Another bracket 80 on the front of the lower end of hanger arm 75 provides a threaded mounting 81 for a threaded crank 82, the lower end of which engages the outer end of the arm 78. Threaded movement of crank 82 will cause the entire lower deflector assembly to swing about its pivotal mounting 77, and the deflectors 70-71 can in this manner be brought into the properly aligned relation with the underside of the primary wire 13. Whatever vertical adjustment is needed for this deflector assembly is carried out by vertical adjustment of the columns 35 on carriages 30, by means of the bolts 36 and brackets 37-38 as already described.
The first of the deflectors for the top wire 22 is a blade 90 provided with a vertically and angularly adjusting mounting on the supplemental frame 20 and located with its working edge in approximately equidistant relation with the two primary wire deflectors 70-71. This mounting comprises a bracket 91 on the downstream side of each of the hangers 58 and a support arm 92 mounted for swinging movement on a shaft 93 journalled in the brackets 91. The blade 90 is secured at its opposite ends to a support plate 95 which is mounted for vertical adjustment on the adjacent arm 92 by a series of shoulder screws 96 mounted in the arms 92 through slots 97 in the supports 95.
A bracket 99 on each arm 91 supports the drive mechanism of a jack assembly 100 having its adjustable part 101 connected to a bracket 102 on the adjacent deflector support 95. These two jack assemblies are operated simultaneously by the shaft 103 by means of the hand wheel 104 on the front end of this shaft. Angular adjustment of the deflector blade 90 about the shaft 93 is effected by a pair of bolts 105 each of which is threaded into one or the other of the hangers 58 through an angle bracket 106 on the deflector support arm 92.
The white water expressed through the wire 22 which travels up the deflector 90 is carried by its own momentum into a saveall 110, which is a sheet metal enclosure of generally rectangular outline having an outlet housing 111 on its front end from which a hose or pipe 112 leads to the white water pit. On its upstream side, the saveall 110 has an extension 115 which is open at 116 along both its bottom and the side facing upstream to receive liquid from the deflector 90.
The second deflector for the wire 22 is a blade 120 mounted for swinging movement in the opening 116 by an arm 121 at each end which is pivotally mounted at 123 on the adjacent end wall of the saveall 110. Adjustment of the deflector arms 121 about the pivotal mounting 123 is effected and controlled by a pair of jack assemblies 125, each of which is pivotally mounted at the upper end thereof on a bracket 126 secured to the top of the saveall 110. The bottom end of each jack assembly is pivotally connected to the associated arm 121 by a cap screw 127 extending from the run 121 through an arcuate slot 128 in the wall of the saveall 110. The jack assemblies 125 are operated by a common shaft having a hand wheel 130 at the front of the unit.
The volume and velocity of liquid deflected into the saveall 110 vary with the speed of the paper machine, and the internal construction of the saveall 110 accordingly includes partition walls at three levels for ensuring that all liquid deflected into its interior will be retained therein until it is drained therefrom by way of the outlet housing 111 and drain line 112. As shown in FIG. 1, the first of these partition walls 135 is located just inside the opening 116 at the upstream end of the saveall. The second partition wall 137 is located at a higher level and near the middle of the saveall, and it includes a shelf portion 138 extending to the downstream wall of the saveall. The third partition wall 138 is located somewhat higher and further back inside the saveall, and it also is at the front edge of a shelf portion 140. These partitions in effect provide the interior of the saveall with three liquid-collecting levels, each of which has its own outlet 141, 142 and 143 into the outlet housing 111.
In addition to the deflectors 70-71 which support the primary wire 13, the supplemental frame 20 carries a suction box 150 which extends below the wire 13 just downstream from the second top wire deflector 120 and has a blade member 151 on its upstream edge and connection means 152 at both ends thereof for alternative connection to a suction box source such as the same source as the suction boxes already present on the Fourdrinier machine. The suction box 150 is supported by a right angled hanger arm 155 like the hanger arm 75, which depends from the front beam 40. A bracket 156 on the back side of the lower end of this arm 155 provides a pivotal mounting 157 for an arm 158 projecting from the front of the suction box 150.
Another bracket 160 on the front of the lower end of hanger arm 155 provides a threaded mounting 161 for a threaded crank 162, the lower end of which engages the outer end of the arm 158. Threaded movement of crank 162 adjusts the angular relation of suction box 150 with wire 13, and vertical adjustment of this suction box assembly is effected by vertical adjustment of the supplemental frame as a whole as described in connection with the bottom deflectors 70-71. If the existing paper machine has its first suction box at an appropriately convenient location, it may be used in place of the suction box 150.
In order to use the testing apparatus of the invention as it is intended to be used with an existing Fourdrinier paper machine, the track assemblies 32 are first installed on the floor of the mill. If there is a hand rail extending in front of the horizontal run of the wire 13, a section thereof must be removed to make room for the top wire unit of the invention, which, however, need not be more than about 11 feet long from end to end.
The supplemental frame 20, with all its associated parts, is preferably mounted on the arms 40 and prepared for use while the stand 25 is retracted from the Fourdrinier machine to the outer end of the tracks 32, and the entire unit is then advanced along the tracks until it is in a position wherein the wire 22 has its outer edge in approximately direct line with the outer edge of the primary wire 13. During these initial procedures, the rolls 55 and 56 are set at heights which will provide a predetermined space between each of these and the wire 13, satisfactory results having been obtained with a space of 0.375 inch for roll 55 and 1.50 inch for roll 56. Also, both of the upper deflectors 90 and 120 are preferably raised so that the wire 22 is supported out of contact with the primary wire 13. Note that all of these operations can be carried out while the paper machine is in normal operation.
After the apparatus of the invention is properly in place, the deflectors 90 and 120 are lowered into their desired positions. For the first deflector 90, this will usually be with its bottom edge substantially in coplanar relation with the two deflectors 70-71 supporting the primary wire. Similarly the lower edge of the second top wire deflector 120 is preferably in or slightly below the plane defined by the deflector 71 and the blade 151 on the suction box 150. Note that these adjustments are made while the paper machine continues to operate.
After these adjustments have been completed, the sheet will be formed by twin-wire operation along the strip of the primary wire 13 which underlies the top wire 22, while conventional single wire formation will continue to take place across the rest of the machine. More specifically, the stock which enters the wedge zone defined by the converging portions of the opposed wire runs from the roll 55 to the deflector 90 will be subject to compression between the converging wire runs and the resulting expression of liquid through both wires.
This action will be accentuated as the sandwich of wire-stock-wire travels past the deflectors 71 and 90 to the second deflector 120 for the top wire, which will be a relatively flat S-course with the deflectors positioned as described. Formation is therefore completed before this sandwich passes deflector 20, and immediately thereafter, the top wire 22 is guided upwardly by the roll 56, while the newly formed sheet is held on the primary wire 13 by the suction box 150 for travel to and beyond the couch roll 12 in the usual way.
The resulting sheet will have the unique characteristic of including a strip formed by twin-wire operation which is integral with sheet formed by the conventional single wire technique. The two types of sheet are easily compared, after the usual pressing and other finishing operations, in order to determine the differences therebetween, which can be expected to include distinctly improved characteristics from the standpoint of reduction of two-sidedness.
The apparatus of the invention thus makes it easy for a paper mill to determine whether the results achieved by top wire formation justify conversion of a particular conventional machine to top former operation. It also makes it possible to investigate different combinations of deflector spacings and the initial angle of convergence of the opposed forming runs of the two wires, as well as different speeds of operation. All of these advantages are made available with no modification of the existing paper machine and therefore no effect on its operation after the test unit of the invention has been removed. Indeed, the paper produced during testing could be included in the regular product of the mill, or if desired, the 16-inch strip of twin-wire sheet could be trimmed away in order to have the salable product uniform across its width.
While the form of apparatus herein described constitutes a preferred embodiment of this invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims. | Apparatus for the purpose of enabling a paper mill to determine the extent to which the performance and/or the product of an existing Fourdrinier paper machine in the mill will be improved by its conversion into a top former machine comprises a fractional version of top forming apparatus which can be readily combined with an existing Fourdrinier machine in such manner that a minor portion of the forming width of the machine will be converted to top forming operation. The apparatus makes it possible to produce, on an existing Fourdriner machine, a sheet of which a small integral portion is formed by drainage through both the primary wire and a top wire, while the remainder of the sheet continues to be produced in the same manner as before the top wire testing. | 3 |
FIELD OF THE INVENTION
This invention concerns a method and apparatus for detecting whether or not warp threads are clinging together as they are unwound from the warp beam in a weaving machine.
DESCRIPTION OF PRIOR ART
A well-known technique used on weaving machines in order to detect warp breaks consists of a warp stop motion in which each warp thread supports a drop wire, so that if a thread breaks the corresponding drop wire falls and makes an electrical contact, ie. closes a pair of electrodes. As a result of this electrical contact being made, a warp stop signal is sent, and this signal is used to initiate a machine stop.
However, as is known, such a signal from the warp stop motion may not necessarily be the result of a warp break, in which case a "false stop" occurs. Such false stops can have various causes.
One possible cause of a false stop may be slack in one of the warp threads, so that the corresponding drop wire closes the contact with the electrode.
Another cause of a false stop may be one or more of the drop wires jiggling up and down as a result of vibrations set up during the weaving process, so that at the lowest point of the jiggle they close the contact with the electrode.
It is common technology not to take account of warp stop signals of short duration, in order to prevent jiggling drop wires causing a machine stop.
A third possible cause of false machine stops may be two or more adjacent warp threads clinging together along part of their length, thus forming a "strap" of the warp.
Such a strap is usually due to an accumulation of the dust that occurs in any weaving mill.
Dust from the weaving shed always falls on the warp. Since during the weaving process the warp threads pass through the drop wires, large accumulations of dust naturally occur at the warp stop motion, in particular at the row of drop wires nearest the warp beam. Such an accumulation can lead to two or more warp threads clinging together, thus forming a strap. This strap may then drag one of the drag wires forward with it as a result of the motion of the warp threads. Due to its relatively light construction the drop wire is liable to be completely twisted out of shape so that contact is made between the two corresponding electrodes. The resulting stop motion signal results in a machine stop, as explained above. Such clinging together of the warp threads may not necessarily be due to an accumulation of dust; it may also be caused by faulty winding on the warp beam.
BRIEF DESCRIPTION OF THE INVENTION
The aim of the present invention is to provide a method and a weaving machine in which this disadvantage does not occur. The invention first of all concerns a method for detecting whether or not warp threads are clinging together, with the characteristic that the method consists of a combination of: initiating a machine stop on reception of a warp stop signal indicating that a contact has been made by a drop wire; checking for a fallen drop wire; starting the machine again at least once if no fallen drop wire is found; and interpreting the warp stop signal that results when the machine starts again, in order to determine whether the warp threads are clinging together.
Checking for a fallen drop wire, for example, can be done by means of a drop wire locator, e.g. as described in U.S. patent application No. 014,778, filed Feb. 3, 1987, owned by the assignee of this patent application, now U.S. Pat. No. 4,791,967.
DESCRIPTION OF THE DRAWING
In order to explain the characteristics of the invention, by way of example only and without being limitative in any way, the following variants of said method and apparatus are described below with reference to the accompanying drawings, where:
FIG. 1 is a schematic diagram of a weaving machine according to the invention, showing an accumulation of dust;
FIG. 2 is a view in the direction of arrow F2 in FIG. 1;
FIG. 3 shows how, as a result of warp threads clinging together, a drop wire can make contact between two electrodes of the warp stop motion.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a schematic representation of the usual parts involved in the weaving process, namely the warp beam 1, the warp threads 2, the heddles 3 for forming the shed 4, the reed 5 for beating in the weft threads, the woven cloth 6 and the cloth beam 7.
As in the usual method for timely detection of breaks in the warp threads 2, the warp stop motion 8 has drop wires 9 suspended on the warp threads. The drop wires are normally arranged in several rows, respectively 10 to 13 in this diagram. When a warp thread breaks, the corresponding drop wire 9 falls and makes an electrical contact, thus resulting in a machine stop.
Additionally, a drop wire locator 14 may be mounted underneath the warp stop motion in order to detect and locate the fallen drop wire 9A, as described in U.S. Pat. No. 4,791,967 identified above.
Dust 15 generated during the weaving process usually falls on the warp threads 2. As can be expected, this dust 15 forms an accumulation 16 at the warp stop motion 8, in particular at the row of drop wires 10 nearest the warp beam 1. As shown in FIG. 2, such as accumulation 16 can lead to several warp threads 2A clinging together and thus forming a strap.
FIG. 3 shows how this dust accumulation 16 can result in a drop wire 9 being dragged along by the warp threads 2, until it is bent out of shape so much that an electrical contact is made between the warp stop electrodes 17 and 18, thus generating a warp stop signal and initiating a machine stop.
In order to determine whether such a machine stop is in fact due to warp threads 2A clinging together, the method of the invention is used, as described below.
In a first variant, when a machine stop occurs a check is made for a fallen drop wire 9A, e.g. by means of the abovementioned drop wire locator. If no fallen drop wire 9A is detected or observed, the weaving machine is restarted. If immediately after the restart a warp stop signal resulting in a machine stop once more occurs, then there is a very high degree of probability that a number of warp threads 2A are clinging together; what is certain is that there are no fallen drop wires 9A, otherwise they would have been detected by the drop wire locator.
Furthermore, stopping and restarting the machine rules out the possibility of the stop having been caused by jiggling of the drop wires 9. The only remaining possibility is the presence of a "strap". In the method of the invention, the second warp stop signal is therefore used to indicate that a number of warp threads are clinging together.
In a second variant of the method of the invention, when a machine stop occurs a check is first made for a fallen drop wire 9A. If no fallen drop wire 9A is detected or observed the machine is restarted. If immediately after the restart a machine stop once more occurs, a second check for a fallen drop wire is carried out by means of the drop wire detector 14.
If no fallen drop wire is detected or observed as a result of this second check, then according to the invention this datum is used to indicate that a number of warp threads 2A are very probably clinging together.
In a variation of the method just described, after the second check for a fallen drop wire 9A the machine can be restarted for a second time. If a machine stop occurs again immediately after this restart, then according to the invention this datum is used to signal that a number of warp threads are clinging together.
In a third variant of the method of the invention, when a machine stop occurs a check is first made for a fallen drop wire 9A. If no drop wire 9A is found the machine is restarted. If immediately after the restart a machine stop once more occurs, a check is made to discover whether the drop wire 9A that instigated the stop motion signal is located on the same row 10-13 as on the previous stop. If there is a strap, it will obviously result in the same drop wire contact being made.
If this second check reveals that the drop wire 9A that instigated the stop motion signal is in fact located on the same row 10-13, then according to the invention this datum is used to indicate that a number of warp stop threads 2A are very probably clinging together.
In yet another variant, use is made of the fact that when a number of warp threads 2 cling together it is very probable that the resulting warp stop signal was instigated by the drop wire row 10 nearest the warp beam 1. In this variant, when a machine stop occurs a check is first made for a fallen drop wire 9A. If no fallen drop wire 9A is found the machine is restarted. If however a second machine stop occurs immediately after the restart, then in this variant of the invention a check is made to discover in which drop wire row 10-13 a contact has been made.
If the contact has been made in the drop wire row 10 nearest the warp beam 1, a signal is given to indicate that a number of warp threads are very probably clinging together. Clearly, this allows the weaver to intervene manually whenever such a signal indicating several drop wires 2A clinging together is given.
However, the method of the invention may be made fully automatic.
A weaving machine using the method of the invention will have e.g. a control unit 19 connected to: the warp stop motion 8, the drop wire locator 14, a signalling unit 20 and the main drive 20 of the weaving machine. The control unit 19 can consist essentially of a number of logic circuits and start-stop circuits for switching the drop wire detector 14 and drive 21 in and out. Such components are already well known, and so do not need further description here. The configuration of the control unit 19 can be quite clearly understood on the basis of the method of the invention as so far described. The present invention is by no means limited to the methods herein described by way of example; on the contrary, such methods for detecting the presence or absence of warp threads clinging together can be implemented in different variants while still remaining within the scope of the invention. | Method for detecting the presence or absence of warp threads clinging together, with the characteristic that it consists principally of a combination of: initiating a machine stop when a warp stop signal is received indicating that a contact has been made by a drop wire 9; checking for a fallen drop wire 9A; and, if no fallen drop wire is found, restarting the machine at least once and interpreting a warp stop motion generated upon restart as an indication that the warp threads 2 are clinging together. | 3 |
This is a division of application Ser. No. 07/633,307, filed Dec. 24, 1990, now U.S. Pat. No. 5,089,774.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus and a method for checking the cause of defects of a semiconductor device such as an LSI.
2. Description of the Prior Art
Conventionally, the following method has been employed in order to check the cause of defects of a semiconductor device such as an LSI. First, the semiconductor device having an electric defect is broken out so that an inner semiconductor chip is exposed. Then, the semiconductor device is electrically checked by means of a semiconductor tester. The result of check is printed out and thus the defect in a circuit of the semiconductor chip is confirmed. With reference to another design drawing, a defective portion (hereinafter referred to as a defective address) on the semiconductor chip is found. As shown in FIG. 9 (a), a semiconductor chip 10' is then taken out of a package of the semiconductor device so as to be cut into a sample chip piece 20 by means of a dicing machine or the like. The sample chip piece 20 has a defective address 21 in the center thereof. As shown in FIG. 9 (b), the back of the sample chip piece 20 is abraded by means of a plane abrasive machine to a thickness of about 50 μm. In FIG. 9 (b), only an abrasive table 26 of the plane abrasive machine is shown. If the thickness of the sample chip piece 20 is less than 50 μm, the sample chip piece 20 may be damaged. Therefore, a charged particle beam processing apparatus is finally used. The detailed description of the above steps will be given later. In brief, with reference to FIGS. 9 (c) and (d), the abraded sample chip piece 20 is mounted on a sample supporting table (sample supporting plate) 27 which is a so-called mesh. Then, the sample supporting table 27 is fixed to the charged particle beam processing apparatus. Consequently, the sample chip piece 20 is rotated together with the sample supporting table 27. At the same time, a charged particle beam is radiated at an angle of 15° to the back of the sample chip piece 20 through a round hole 271 formed in the center of the sample supporting table 27. Consequently, the center of the back of the sample chip piece 20 is made cone-shaped. The center of the sample chip piece 20 is abraded to a thickness of about 50 nm. Then, the defect of crystals in the defective address of the sample chip piece 20 is observed by means of a transmission type electron microscope so that the cause of defects of the semiconductor device is checked.
In the prior art, however, there have been pointed out the following drawbacks.
Even if the defective portion on the circuit of the semiconductor chip 10' can be confirmed by the semiconductor tester, a physical position (the defective address 21) of the semiconductor chip 10' should be specified with reference to the design drawing. This process is so complicated that the skilled often make an error.
In addition, even if the defective address 21 of the semiconductor chip 10' can be confirmed, the defective address 21 rarely corresponds to the center of the sample chip piece 20 to be observed by the transmission type electron microscope. In the cast where the semiconductor chip 10' is repeatedly formed with patterns, a great problem is especially raised. As a result, the cause of defects of the semiconductor device cannot be checked precisely.
Next, a conventional charged particle beam processing apparatus will be described in detail.
In FIG. 10, a material supporting table 127 is supported by three legs 109 and can be rotated in a direction of an arrow. The reference numeral 108 denotes screws by which the legs 109 are fixed to the material supporting table 127.
The reference numeral 120 is a material which is positioned on a material reinforcing plate 104. The reference numeral 110 denotes charged beam particles which are radiated on the material 120 obliquely.
As shown in FIG. 10 (c), scattered substances 111 adhere to a portion (a lower surface), on which the charged beam particles 110 do not directly strike, through a path 113, i.e., a path on the periphery of the material supporting table 127, or through a clearance between the material reinforcing plate 104 and the material supporting table 127. In addition, various dirt particles 112 adhere to the aforementioned portion in an atmosphere.
In other words, as shown in FIG. 11, a dirt layer 115 adheres to the back of the material to be flaked. Consequently, a portion 120' to be observed by the transmission type electron microscope is superposed on the dirt layer 115, so that the material itself cannot be observed by the transmission type electron microscope.
The charged beam is radiated in the opposite direction so that the dirt layer 115 is abraded. Consequently, the portion 120' is exposed so as to be observed by the transmission type electron microscope.
In order to confirm whether the flaked material can be observed by the transmission type electron microscope when the charged beam abrasion is completed, the following countermeasure is considered. In other words, there is provided a device for radiating light on the portion to be processed in one direction so that the light can be detected in the opposite direction. In addition, a hole is formed on the material supporting table so that the light can be transmitted. If the hole is opened, the abrasion is automatically completed.
However, the aforementioned prior art has the following drawbacks.
(1) In the case where the dirt layer adheres to a non-abraded surface, it is required to radiate the charged beam on the dirt layer to be abraded. However, the portion 120' to be observed by the transmission type electron microscope (see FIG. 11) is often abraded and removal together with the dirt layer. Consequently, a good image of the material cannot be obtained by the transmission type electron microscope.
(2) The scattered substances 111 adhere to the nonabraded surface not only through the path 113 but also through a path 114 between the material supporting table 127 and the material reinforcing plate 104 (mesh).
(3) When the charged beam abrasion is completed, it is required to detect an end point by light transmission in order to decide whether the material surface can be observed by the transmission type electron microscope. Therefore, even if it is known that the dirt is produced, a hole must be formed on the material supporting table body.
SUMMARY OF THE INVENTION
The present invention provides an apparatus for checking a semiconductor comprising an X-Y stage for movably holding a semiconductor chip in terms of X-Y coordinates, charged particle beam radiating means for radiating a charged particle beam on the semiconductor chip held in the X-Y stage to generate secondary electrons therefrom, detecting means for detecting secondary electrons emitted from the semiconductor, magnifying means for displaying an enlarged image of the semiconductor chip on the basis of data of the detected secondary electrons, a semiconductor tester for measuring electrical characteristics of the semiconductor chip to specify a defective element of circuit elements constituting the semiconductor chip on the basis of a result of the measurement, defective portion locating means provided with table data of a layout pattern showing the relationship between the circuit elements constituting the semiconductor chip and the arrangement thereof, for obtaining on the basis of the table data position data of the defective circuit element specified by the semiconductor tester, and control means for issuing instructions to operate the X-Y stage, charged particle beam radiating means, and magnifying means, and further to cause the charged particle beam radiating means to impress marks on the semiconductor chip for indicating a position of the defective circuit element in positions apart from the defective circuit element at predetermined spaces by the charged particle beam radiation on the basis of the position data of the defective circuit element obtained by the defective portion locating means.
According to the present invention, the control means controls the charged particle beam used for displaying an enlarged image of the semiconductor chip so as to impress marks for indicating a position of the defective circuit element of the semiconductor chip. Consequently, the cause of defects of the semiconductor chip can be checked precisely and easily.
In another respect, the present invention can provide a method for checking a semiconductor comprising the steps of radiating a charged particle beam to impress marks in positions apart from a defective circuit element of the semiconductor chip at predetermined spaces, cutting the semiconductor chip having the marks into a sample chip piece, and specifying the defective circuit element on the sample chip piece based on the marks by means of a transmission type electron microscope so as to check the cause of defects of the circuit element.
In a further respect, the present invention can provide a charged beam processing apparatus comprising a supporting table having a hole provided in the center thereof, a material reinforcing plate of an annular shape provided on an inner peripheral edge of the hole, a surface guard plate, a frame removably provided on the supporting table for sealing the hole on a non-abraded surface side of the sample chip piece, an annular presser plate provided on the supporting table for sealing an annular clearance between the supporting table and the material reinforcing plate on the non-abraded surface of the sample chip piece, and a charged beam mirror for radiating the charged beam on the sample chip piece which is placed so as to cover the hole defined by the material reinforcing plate so that the sample chip piece is processed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view showing a structure of a semiconductor checking apparatus;
FIG. 2 is a view showing an enlarged image of a semiconductor chip having marks;
FIG. 3 is a view showing a state in which a sample chip piece is cut out of the semiconductor chip;
FIG. 4 is a view showing a state in which the sample chip piece is abraded by means of an abrasive machine;
FIG. 5 (a) is a view showing a state in which the sample chip piece is flaked by means of a charged particle beam processing apparatus;
FIG. 5 (b) is a section view of the sample chip piece corresponding to FIG. 5 (a);
FIG. 6 (a) is a plan view of a material supporting table which is a main portion of the charged beam processing apparatus;
FIG. 6 (b) is a section view taken along the line A-A' of FIG. 6 (a);
FIG. 6 (c) is a bottom view of the material supporting table;
FIG. 7 (a) is a perspective view of the material supporting table seen from above;
FIG. 7 (b) is a perspective view of the material supporting table seen from below;
FIG. 7 (c) is a central section view of the material supporting table;
FIG. 8 is a typical section view of a sample to be observed by a transmission type electron microscope, a central portion of the sample being enlarged;
FIGS. 9 (a) to (d) are views for explaining a conventional example corresponding to FIGS. 3, 4, and 5 (a) and (b), respectively;
FIGS. 10 (a) to (c) are views for explaining the conventional example corresponding to FIGS. 7 (a) to (c), respectively; and
FIG. 11 is a view for explaining the conventional example corresponding to FIG. 8.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
There will be described a schematic structure of a semiconductor checking apparatus with reference to FIG. 1.
In FIG. 1, the reference numeral 16 denotes an evacuator which evacuates the inside of the semiconductor checking apparatus. The semiconductor checking apparatus has an X-Y stage 1 provided on the inner bottom thereof. The X-Y stage 1 moves a semiconductor device 10 freely in terms of X-Y coordinates. The reference numeral 2 denotes an X-Y stage controller. The semiconductor device 10 can be connected to a connector 9 which is provided on the X-Y stage 1. With the semiconductor device 10 connected to the connector 9, an LSI tester 5 (which corresponds to a semiconductor tester) checks defective portions on a circuit of the semiconductor device 10 (the detailed description will be given later).
The semiconductor device 10 has a top portion of a package broken out in advance (not shown). Consequently, an inner semiconductor chip 10' is exposed.
On the other hand, an apparatus body has a beam generating portion 11 provided in an upper portion thereof. The beam generating portion 11 generates a charged particle beam 18 to be emitted toward the X-Y stage 1. An aperture 12, a scanning coil 3, an aperture 12, a beam lens 14 and a lens 15 for correcting beam non-point aberration are sequentially provided between the beam generating portion 11 and the X-Y stage 1. In other words, the aforementioned optical lens system gives energy to the charged particle beam 18 which is generated by the beam generating portion 11. Consequently, the charged particle beam 18 is converged and scanned so as to be radiated on the semiconductor chip 10'. A timing for scanning the charged particle beam 18 is controlled by a scanning controller 3' on the basis of synchronizing signals outputted from a display 8 to be described below.
When the charged particle beam 18 having the predetermined energy is radiated on the semiconductor chip 10', secondary electrons are generated from the radiated portion. The secondary electrons are detected by a secondary electron detector 7 which is provided in the vicinity of the X-Y stage 1. The signals outputted from the secondary electron detector 7 are successively introduced into the display 8 through a secondary electron signal amplifier 7' so that an enlarged image of the semiconductor chip 10' is displayed and outputted.
Next, there will be described the LSI tester 5. The LSI tester 5 has data on electric characteristics of the semiconductor device 10 prestored therein. Wit the semiconductor device 10 powdered, a predetermined operation is carried out so that the detective portions on the circuit can be checked. If the semiconductor device 10 is a dynamic memory, the predetermined data is written into all addresses and then read out in order of address. If the read data is different from others, it is decided that a circuit element portion corresponding to the address is defective. The data for defective portions on the circuit of the semiconductor device 10, which are outputted from the LSI tester 5, are led to a computer 4 in a predetermined timing.
The computer 4 has a program required to control the entire apparatus prestored therein. In addition, the computer 4 gives individual instructions for predeterminately operating the LSI tester 5, the display 8, an X-Y stage controller 16, the scanning controller 3' and the like through a data transfer network 17. Furthermore, the computer 4 is provided with a data base 6 such as a floppy disc which serves as a mass external memory. The data base 6 stores table data of a layout pattern showing the relationship between circuit elements constituting the semiconductor chip 10' and the arrangement thereof. In other words, the individual data stored in the data base 6 are coordinate data for every circuit element formed on the semiconductor chip 10'. The coordinate data are displayed by means of X'-Y' coordinate system. The X'-Y' coordinate system is set such that a plurality of alignment marks provided on the semiconductor chip 10' are reference points. Software of the computer 4 has a function of locating the defective portions.
Next, there will be described an operation of the semiconductor checking apparatus having the above structure and a function of the computer 4.
First, the semiconductor device 10 of which semiconductor chip 10' is exposed is connected to the connector 9 so as to operate the LSI tester 5. Then, the LSI tester 5 gives the data for the defective portions on the circuit of the semiconductor device 10 to the data base 6 through the computer 4. The data which are given to the data base 6 relate to the defective circuit element in the semiconductor chip 10' as described above, and are converted by the table data of the data base 6 so that the coordinate data corresponding to the circuit elements are obtained (the aforementioned function of the computer 4 corresponds to that of a section for locating defective portions). The coordinate data become data which give the defective portion of the semiconductor chip 10', i.e., a defective address 21 (see FIG. 2). Then, the coordinate data are once stored in predetermined addresses of the data base 6.
In consideration of the degree of integration of the semiconductor device 10, it is required that feed precision of the X-Y stage 1 is 0.1 μm or less. In a method of attaching the semiconductor device 10 to the X-Y stage 1, however, positioning precision of the semiconductor device 10 for the X-Y stage 1 becomes a problem. Therefore, the alignment marks in the semiconductor chip 10' are enlarged and displayed. Then, the X-Y stage 1 is operated so that the alignment marks correspond to the reference points of the X-Y coordinate system which are simultaneously displayed on a screen. Consequently, the X-Y coordinate system on the X-Y stage 1 side corresponds to the X'-Y' coordinate system on the semiconductor chip 10' side irrespective of the connection of the semiconductor device 10 to the connector 9.
Then, when the X-Y stage 1 is operated on the basis of the coordinate data of the defective address 21 which is stored in the data base 6, the defective address 21 on the semiconductor chip 10' is displayed on the screen of the display 8. FIG. 2 shows an image, which is enlarged by the display 8, in the vicinity of the defective address 21 on the semiconductor chip 10'. In FIG. 2, the reference numeral 22 denotes a circuit pattern which is provided like a lattice on the semiconductor chip 10' and the reference numeral 23 denotes a reference point (which corresponds to a reference point of marking to be described below) on the display 8 side.
As shown in FIG. 2, the following process is performed so that four marks 24a to 24d are impressed in positions apart from the defective address 21 on the semiconductor chip 10' at predetermined spaces.
First, the coordinate data in positions in which the marks 24a to 24d are to be impressed are calculated on the basis of the coordinate data of the defective address 21 stored in the data base 6. In this case, there are read the pattern data on the positional relationship between the defective address 21 prestored in the data base 6 and the marks 24a to 24d. When the coordinate data is calculated, the beam generating portion 11, the scanning controller 3' and the like are operated so that the charged particle beam 18 having the predetermined energy is scanned and radiated on the semiconductor chip 10'. Consequently, holes are formed by radiation of the charged particle beam 18, so that the marks 24a to 24d are impressed in desired positions.
There will be described the form of the marks 24a to 24d and the like. The size of the marks 24a to 24d and the distance between the marks 24a to 24d and the defective address 21 are set such that the marks 24a to 24d and the defective address 21 can be displayed on the screen of the display 8 and confirmed clearly. If the size of the marks 24a to 24d are 2 to 3 μm square or more, the marks 24a to 24d can be observed by means of a stereomicroscope of about 40 magnifications. In addition, the marks 24a to 24d are shaped such that the position of the defective address 21 can clearly be confirmed. Furthermore, the entire form of the marks 24a to 24d is asymmetrical. The marks 24a to 24d have a plurality of patterns which can properly be selected according to the shape of the defective portion.
In consideration of a flaking step to be described below, the depth of the marks 24a to 24d is set to a value necessary for the semiconductor chip 10' to reach a semiconductor substrate. If the defects are not caused by the semiconductor substrate but by a shallow electrode portion, it is not necessary for the depth of the marks 24a to 24d to reach the semiconductor substrate.
In the present embodiment, the charged particle beam generated by the beam generating portion 11 is a gallium ion beam. A beam diameter is set to 500 Å or less so that good images can be obtained at the time of image display. In the case where the marking is performed, a current value can be set higher than the aforementioned value so as to increase a processing speed. In this case, the current value may be increased so that the beam diameter is about 2000 to 3000 Å.
When the marking is completed, the display 8 is operated so as to confirm whether the positional relationship between the marks 24a to 24d and the defective address 21 is precise by means of the enlarged image.
When the confirmation is completed, the semiconductor device 10 is taken out of the semiconductor checking apparatus. Then, a sample for a transmission type electron microscope (not shown) is prepared.
First, the semiconductor chip 10' is taken out of a package of the semiconductor device 10. As shown in FIG. 3, the semiconductor chip 10' is cut into a sample chip piece 20 by means of a dicing machine (not shown). The size of the sample chip piece 20 is suitable for the sample of the transmission type electron microscope, i.e., about 1.5 mm square. In this case, the sample chip piece 20 is precisely cut out by means of the stereomicroscope attached to the dicing machine so that the defective address 21 is positioned in the center of the sample chip piece 20. The centering is greatly concerned with observation precision of the transmission type electron microscope. Therefore, it si required to perform the centering carefully.
Next, the sample chip piece 20 thus cut away from the semiconductor chip 10' is taken out of the dicing machine. Then, a surface forming layer such as an electrode in the sample chip piece 20 is flaked by means of chemicals. The chemicals by which the semiconductor substrate of the sample chip piece 20 is not affected are used for flaking. If the defects are not caused by the semiconductor substrate but by the shallow electrode portion, the flaking is performed so that the electrode portion is exposed.
When the flaking is completed, the flaked sample chip piece 20 is abraded so as to have a depth of 50 μm or less by means of a rotary abrasive machine and then is mirror-abraded. FIG. 4 shows a state in which the back of the sample chip piece 20 is abraded by means of the abrasive machine. In FIG. 4, parts other than an abrasive table 26 are omitted. In order to obtain high abrasive precision, dimple-like mechanical abrasion is sometimes carried out. In this case, the center of a dimple is caused to correspond to the center of the defective address 21, the sample chip piece 20 is abraded to have a depth of 10 μm or less and the mirror-abraded so that the back of the defective address 21 is made the thinnest. In case of the dimple-like abrasion, if the depth of the marks 24a to 24d is set of about 10 μm, the marks 24a to 24d are seen through the back of the sample chip piece 20 during the abrasion. Consequently, even if the center of the dimple does not correspond to the center of the defective address 21, a processing position can be corrected in the middle of the abrasion.
When the abrasion is completed, the sample chip piece 20 is finally flaked by means of another charged particle beam processing apparatus K. While the specific description of the charged particle beam processing apparatus K will be given later, its brief description is as follows. First, the mirror-abraded sample chip piece 20 is fixed to a sample supporting plate 27 (mesh) shown in FIG. 5 and then mounted on the charged particle beam processing apparatus. When the charged particle beam processing apparatus is operated, the sample chip piece 20 is rotated together with the sample supporting plate 27. At the same time, the charged particle beam is radiated toward the center of the back of the sample chip piece 20 through a round hole 271 which is formed in the center of the sample supporting plate 27. Consequently, the back of the sample chip piece 20 is made cone-shaped. In the above method, the center of the defective address 21 of the sample chip piece 20 is flaked so as to have a depth of about 50 μm.
According to the charged particle beam processing apparatus, an argon ion beam which is relatively thick is used in order to increase the processing speed and an incident angle to the back of the sample chip piece 20 is set to about 10° to 15°.
When the flaking is completed, the sample chip piece 20 is taken out of the charged particle beam processing apparatus together with the sample supporting plate 27 and then mounted on the transmission type electron microscope (not shown). An enlarged image o the sample chip piece 20 is displayed and outputted by the transmission type electron microscope. At this time, since the marks 24a to 24d are clearly displayed on the screen, the defective address 21 can be specified without errors. The cause of defects of the semiconductor device 10 is checked by the enlarged image.
In the case where the cause of defects of the semiconductor device 10 is checked in the above procedure, the following effect can be obtained if the semiconductor checking apparatus is used.
In other words, even if the defective address 21 does not correspond to a portion of the sample chip piece 20 which is flaked so as have a depth of about 50 μm by the charged particle beam processing apparatus, the non-correspondence can be confirmed by the marks 24a to 24d in a stage in which the image of the sample chip piece 20 is enlarged and displayed by the transmission type electron microscope. Consequently, the address can be checked without errors. Since the image can be obtained even if the sample chip piece 20 is turned over, the defective address 21 may be confirmed with errors. However, since the entire form of the marks 24a to 24d is asymmetrical, it can be confirmed that the sample chip piece 20 is turned over. Accordingly, the transmission type electron microscope can display and output the directly enlarged image of a portion which is electrically defective on the semiconductor chip 10' of the semiconductor device 10. Consequently, the cause of defects of the semiconductor device 10 can be checked precisely and effectively.
The semiconductor checking apparatus of the present invention is not limited to the above embodiment. There may be employed a so-called inverted semiconductor checking apparatus in which the charged particle beam is radiated on the semiconductor chip from a lower portion thereof. In the case where the above form is used, the connector for connecting the semiconductor chip to the LSI tester can be attached to the apparatus downward and a tester head can be mounted on the connector. Therefore, electric wires can be made as short as possible so that a noise can be reduced. Consequently, the electrical checking can be performed on the semiconductor chip with high precision.
According to a semiconductor checking apparatus H having the above structure, the data of the defective circuit element of the semiconductor chip specified by the semiconductor tester can be obtained by the section for locating defective portions. Consequently, the defective address of the semiconductor chip can be obtained automatically. Therefore, the defective address can precisely be obtained without performing the conventionally complicated working. In addition, when the charged particle beam is radiated, the marks are impressed so as to indicate the defective address of the semiconductor chip. Consequently, the defective address of the semiconductor chip can be specified without errors in the subsequent steps.
On the other hand, according to a method for checking a semiconductor of the present invention, the defective address can be specified without errors based on the marks on the semiconductor chip by means of the transmission type electron microscope. Consequently, the state of the defective address can be observed directly.
Accordingly, the cause of defects of the semiconductor device can be checked precisely and effectively.
Next, there will be described a specific example of a charged particle beam processing apparatus 100 K.
In FIGS. 6 to 8, the reference numeral 101 denotes a surface guard plate which is square-shaped. The reference numerals 105, 105 denote springs which are strip-shaped. The surface guard plate 101 is pressingly and removably fixed to a material supporting table (sample supporting plate) 127 by the springs 105, 105 and frame member F. Although the frame F is illustrated in FIG. 7(B) as including only two side members, the three-sided frame member F as shown in FIG. 6(C) is preferred. The reference numeral 102 denotes a presser plate. The presser plate 102 has an annular portion and portions which are rectangularly extended from the annular portion right and left. In addition, the presser plate 102 has a sufficient size to cover an annular clearance between a material reinforcing plate 104 and the material supporting table 127 and has the rectangularly extended portions fixed to the material supporting table 127 by means of screws 106, 106'. Consequently, the clearance between the material reinforcing plate 104 and the material supporting table 127 is covered and the material reinforcing plate 104 is fixed to the material supporting table 127. If loosened, the screws 106, 106' can easily be removed from the presser plate 102 and a groove 102' of the presser plate 102. Consequently, the presser plate 102 can be removed from the material supporting table 127. Accordingly, a processed material (sample chip piece) 120 can easily be taken out of the material supporting table 127 together with the material reinforcing plate 104.
There will be described a series of working of the following case in accordance with the procedure. In other words, a material formed by applying a polycrystalline silicon onto a surface of a silicon monocrystalline semiconductor is observed by a transmission type electron microscope on a plane basis as described below.
(1) First, a silicon wafer is cut out by means of a glass cutter or scribe machine so as to have a size of 1 mm square.
(2) The silicon wafer thus cut out has a thickness of 300 to 700 μm normally. Therefore, the side to which the polycrystalline silicon is not applied is mechanically abraded to a thickness of 50 to 100 μm. The mechanical abrasion is performed on a rotary abrasive table by means of an about 2000-count sand paper or an abrasive solution in which a diamond abrasive grindstone having a size of 2 to 3 μm is floated until the silicon wafer has a thickness of about 50 to 100 μm. Then, buff abrasion is performed on the mechanically abraded side to be mirror-finished by means of a diamond having a size of about 0.5 μm or an abrasive solution in which an alumina abrasive grindstone is floated.
(3) Next, a material 120 is stuck by means of a rubber adhesive or an epoxy adhesive with the polycrystalline silicon 120' side, i.e., the non-abraded side opposite to the material reinforcing plate 104 (generally referred to as a mesh). In this case, it is required that the material 120 is stuck so as not to form a clearance between the material 120 and the material reinforcing plate 104.
(4) Then, the material 120 is placed on the material supporting table 127 together with the material reinforcing plate 104. Thereafter, the presser plate 102 is fixed onto them by means of the screws 106, 106'. In this case, the non-abraded side, i.e., the side to which the polycrystalline silicon is applied is arranged toward the material supporting table 127 side, while the side which is abraded and mirror-finished with being fixed by means of the presser plate 102 is arranged so as to be exposed to the charged beam.
(5) The surface guard plate 101 is inserted into a groove formed on the underside of the material supporting table 127 in which springs are provided, and then pressingly fixed to the material supporting table 127. In this case, it is preferred that a glass plate having a thickness of 150 to 200 μm is used as the surface guard plate 101. In addition, there may be used a transparent plastic having any material and thickness such as an acrylic plate or a vinyl plate.
(6) The entire material supporting table 117 is mounted on the charged beam processing apparatus to be evacuated. When the degree of vacuum reaches 1×10 -5 torr or less at which the charged beam is generated, an Ar ion beam of I ion beam is radiated so as to perform abrasion. The ion beam having a size of about 0.3 mm is radiated at an angle of about 15° to a horizontal surface of the material so that the abrasion is performed. In this case, it is required to rotate the material supporting table 127 once or twice per minute so that the material is abraded in order to have a uniform thickness entirely.
When passing through a path 113 on the periphery of the material supporting table 127, particles which are abraded and scattered by the ion beam adhere to the surface guard plate 101. When passing through a path 114 between the material reinforcing plate 104 and the material supporting table 127, the particles adhere to the presser plate 102. As a result, there can be prepared a sample suitable for observation by the transmission type electron microscope without the scattered particles adhering to the surface of the material. Packing is provided on the material supporting table 127 side between the presser plate 102 and the material supporting table 127 and between the surface guard plate 101 and the material supporting table 127 so that the scattered particles can be blocked completely. The packing is formed of a material which cannot be processed by an Ar ion or the like.
A He-Ne laser beam is radiated on the material with a light receiving element provided on the underside thereof, so that the progress of abrasion can be known. In other words, when the silicon wafer is made thinner so that the transmission of the laser beam can be confirmed by the light receiving element, the radiation of the ion beam is stopped.
In the present embodiment, a laser beam which is excellent in rectilinearity is used so that the distance between a light source and a light receiving portion can be greater. While a silicon is employed as a material in the present embodiment, the surface guard plate of which light transmittance is reduced may be used if there is used a material through which light can be transmitted more easily.
In a prior art, since a polycrystalline silicon 120' is superposed on a dirt layer 115 in a portion through which an electron beam 116 can be transmitted as shown in FIG. 11, an image of the polycrystalline silicon cannot be observed by the transmission type electron microscope separately. As shown in a typical section view of a sample to be observed by the transmission type electron microscope in FIG. 8, in the case where the monocrystalline silicon (material) 120 is superposed on the polycrystalline silicon 120', only the polycrystalline silicon 120' is provided in a portion through which the electron beam 116 can be transmitted. Consequently, it can experimentally be confirmed that the good image of the polycrystalline silicon can be obtained by the transmission type electron microscope.
According to the charged beam processing apparatus 100 K having the above structure, a non-abraded surface, i.e., a portion to be observed by the transmission type electron microscope can be prevented from being made dirty. The non-abraded surface is produced by flaking the material through the charged beam so as to adjust the sample to be observed by the transmission type electron microscope. Consequently, the good image of the sample can be obtained by the transmission type electron microscope. In addition, the precision in composition analysis and electron beam analysis can be increased. Consequently, the precision in evaluation of the material is increased so that the development and research of the material can greatly be promoted.
More specifically, the charged beam processing apparatus 100 K has the following structure. In other words, the surface guard plate through which the light can be transmitted is removably fixed to the non-processed side of the material by means of the springs. In addition, a clearance between the material reinforcing plate and the material supporting table is blocked by the presser plate on the abraded surface side. Consequently, the following effects can be obtained.
(1) In the most important step, i.e., a step of preparing a super thin film, another thin film (a dirt layer) is not formed of substances other than an obstruction material. Therefore, the image of the sample can be prevented from being deteriorated. Consequently, the resolution of the image observed by the transmission type electron microscope can be enhanced.
(2) In the prior art, if the dirt layer adheres to the thin film, the charged beam is radiated on the dirt layer to be abraded and removed again so that the image observed by the transmission type electron microscope can be prevented from being deteriorated. However, when the dirt layer is abraded, the portion to be observed is also abraded frequently. Even if the portion to be observed is slightly abraded, the damage is caused by the abrasion. Consequently, the good image cannot be obtained. According to the apparatus of the present invention, since the dirt layer does not adhere to the thin film, it is not required to radiate the charged beam on the portion to be observed. Therefore, the portion to be observed can be held in its original state. Consequently, the good image can easily be obtained.
(3) The transmission type electron microscope also has a function of obtaining an electron beam analysis image. A harrow pattern showing an amorphous state appears on the dirt layer. Accordingly to the apparatus of the present invention, in the case where it is not clear whether the material is in the amorphous or crystalline state, or the material is in the amorphous state, the harrow pattern odes not appear on the dirt layer formed on the portion to be observed. Consequently, the crystallization of the material can be evaluated more precisely.
(4) Some of the transmission type electron microscopes have an analyzer attached thereto so that the composition of the material can be analyzed. According to the apparatus mentioned above, if the dirt layer is formed, the composition of he material and dirt layer is simultaneously analyzed. Therefore, the analysis cannot be performed precisely. According to the apparatus of the present invention, the dirt layer is not formed. Consequently, the composition of the material can be analyzed precisely.
(5) Since the surface guard plate is formed of a material through which the light can be transmitted, the dirt layer does not adhere to the material. Consequently, there can be held a function of detecting an abrasion end point.
(6) When the surface guard plate is used for hours, the dirt layer gradually adheres to the surface of the surface guard plate. According to the apparatus of the present invention, however, the surface guard plate is fixed by the springs so as to be removed freely. Consequently, if the dirt layer adheres to the material so as to disorder the function of detecting an abrasion end point, the surface guard plate can freely be exchanged with a new one. | An apparatus for checking a semiconductor comprising an X-Y stage for movably holding a semiconductor chip in terms of X-Y coordinates, a charged particle beam radiating device for radiating a charged particle beam on the semiconductor chip held in the X-Y stage to generate secondary electrons therefrom, a detecting device for detecting secondary electrons emitted from the semiconductor, a magnifying device for displaying an enlarged image of the semiconductor chip on the basis of data of the detected secondary electrons, a semiconductor tester for measuring electrical characteristics of the semiconductor chip to specify a defective element of circuit elements constituting the semiconductor chip on the basis of a result of the measurement, a defective portion locating device provided with table data of a layout pattern showing the relationship between the circuit elements constituting the semiconductor chip and the arrangement thereof, for obtaining on the basis of the table data position data of the defective circuit element specified by the semiconductor tester, and a control device for issuing instructions to operate the X-Y stage, charged particle beam radiating device, and magnifying device, and further to cause the charged particle beam radiating device to impress marks on the semiconductor chip for indicating a position of the defective circuit element in positions apart from the defective circuit element at predetermined spaces by the charged particle beam radiation on the basis of the position data of the defective circuit element obtained by the defective portion locating device. | 6 |
This is a continuation in part of U.S. patent application Ser. No. 08/677,830, filed Jul. 10, 1996, now abandoned
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to alarm systems and detectors or peripheral devices such as those that connect smoke alarms to central alarm panels. It has to do typically with fail safe sensitive monitors and signalers for interconnect lines of AC-powered smoke alarms with battery backup.
2. Description of the Prior Art
Alarm systems often contain multiple sensors including smoke detectors, heat detectors, motion detectors, and switches that determine the open or closed state of a door or window. In some systems the individual sensors or a plurality of sensors are monitored by the system using one or more electronic loops, and the system sounds an alarm when one of the sensors is triggered. Such systems and loops are discussed in the prior art (U.S. Pat. Nos. 4,141,007; 4,144,528; 4,162,489; 4,176,346; 4,517,555; 4,191,946; 4,586,028; 4,745,398). In other types of alarm systems, the sensors themselves may contain alarm horns. Such devices may be standalone devices or be interconnected such that if one is triggered, the others also become triggered by an interconnect line. Such circuits are described in the prior art (U.S. Pat. Nos. 4,194,192; 4,207,558; 4,972,181; 4,138,670).
This interconnect mode of operation is available in AC powered smoke detectors with battery back up. One such detector is the model 86RAC manufactured by BRK Electronics of Aurora, Ill. The backup is a 9-volt battery, and when the alarm is activated, something less than 9 volts DC is available on the interconnect line at a maximum current of approximately 6 milliamps. Total available power available may be considerably less if a poorly charged battery is required to power the interconnect line. This smoke detector is sold as a stand alone smoke alarm system with no UL approved means offered by the manufacturer to connect it to a central alarm system panel which could then call an alarm company.
Thus, if someone with AC smoke detectors with battery backup and interconnect capabilities (AC-DC-interconnect detectors) wanted to have smoke detectors connected to a central alarm panel, they would have to buy a different type of smoke detector manufactured for that purpose. These additional detectors are DC powered smoke detectors. There are fundamental differences in the operation of these smoke detectors that are important to appreciate in order to understand the operation of the present invention. Typically, the DC detectors have no horn. When they sense smoke, they communicate this condition to the central alarm panel by producing a short or near short across a loop from the central alarm panel. The loop is created by two leads from the panel, which are joined at their free ends by a so-called "end of line resistor." The central alarm panel circulates current through the loop. The panel expects a predetermined amount of current to be in the loop, based on the loop resistance generated by the end of the line resistor. If a break or high impedance state occurs in the loop, the panel recognizes the decrease or loss of current and reports this "trouble state" to the alarm user as a unique signal that differs from the signal that would be used if the detector sensed smoke. The signal may be audible or visual or both. If the central alarm system panel is so equipped, it will also call an alarm company and report the condition.
Leads from the DC smoke detector(s) make contact with the loop such that the detector is wired in parallel with the end of line resistor. Thus, when smoke is detected and the detector shorts the loop, the central alarm panel notes the change in the loop current from the predetermined value to a much higher current which is limited by resistance in the circuitry supplying current to the loop. The central alarm panel then activates a unique audible and/or visual signal for the alarm user and, if equipped, calls an alarm company.
Thus, when connecting DC smoke detectors to a central alarm panel, one uses a loop from the panel, and the loop is of special type that can appreciate three different states. In the "no alarm, no trouble state" a predetermined current is noted circulating through the loop. In a "trouble state," low current is noted in the loop. In the "alarm state" high current is noted in the loop. This type of loop will be referred to in the specification as a "smoke detector loop." This designation will distinguish it from the other type of loop typically offered by central alarm panels--the "normally closed loop." This latter type of loop is supplied with a predetermined current from the central alarm panel that senses the presence or absence of the current. Such loops are typically wired with a switch in series. An example is a magnetic switch on a window that maintains a closed loop when the window is closed and an open switch when the window is open. Such loops cannot distinguish a "trouble state" from an "alarm state" as both conditions produce the same result, namely, opening the loop.
The AC-DC-interconnect detectors are inexpensive and sometimes required by building codes in new constructions. The DC smoke detectors are considerably more expensive and if added to the system will add substantial cost. It would thus be advantageous to have a circuit available that would allow one to interface the AC alarms to a central alarm system panel.
This might be accomplished by a relay that would open a normally-closed loop from a central alarm system panel when the interconnect line goes hot. There are, however, two problems with that approach.
1. Conventional relays would not be able to be powered by minimal battery power should the AC power fail.
2. The relay would never be opened if the interconnect line was disrupted between the active alarm and the relay.
A desirable circuit would thus be capable of being powered by a weak battery and be activated by discontinuity of the interconnect line. Furthermore, the circuit should be fail-safe, which means that failure of any component in the circuit would result in opening of the alarm loop. This is a quality that would be advantageous if not necessary in obtaining a listing from the Underwriter's Laboratory (UL). Such listing would almost certainly be required in order for contractors to install the device.
Line monitors and fail safe circuits are known, but none are designed as stand alone circuits with the inherent simplicity of the present invention or for the same type of purpose--the interfacing of AC smoke detectors having battery backup and interconnect capabilities to a central alarm system panel. That interconnect lines were described for use in self powered smoke alarms (U.S. Pat. Nos. 4,194,192; 4,207,558) more than 15 years ago and that to date no UL-APPROVED device to couple those interconnect lines to central alarm panels has been made commercially available speaks for the lack of obviousness of the circuitry of this invention.
SUMMARY OF THE INVENTION
New residential constructions are often required by code to have smoke detectors installed on each floor of the dwelling, and in some codes, they must also be installed in each bedroom. Additional specifications mandate that the detectors be AC powered, have a battery back up in each detector, and be interconnected (by an interconnect line) such that if one detector goes into alarm, they all go into alarm. This type of detector, described above in the "Background of the Invention," will be referred to as an AC-DC-interconnect detector. The main purpose of the present invention (hereinafter often referred to as SMAS, for "Sensitive Monitor And Signaler") is to connect arrays of such smoke detectors to a central alarm panel such that an alarm or trouble condition can be communicated to a remote monitoring station.
The SMAS accomplishes this by monitoring the status of the interconnect line. Two typical embodiments are described. In the first embodiment (FIG. 1) the detectors are connected via the SMAS to a "normally-closed loop" from the central alarm panel. When the status is "no alarm," the loop from the central alarm panel is held closed by the SMAS. When the status is "alarm," the said loop is opened by the SMAS. This embodiment additionally provides fail safe features by signaling an "alarm" condition when any part of the circuit is interrupted, that is, if the SMAS circuit loses power, if the interconnect line is broken, or if the loop to the central alarm panel is broken. Such conditions are typically referred to as a "trouble state". Thus, this embodiment does not allow the central alarm panel to distinguish an "alarm state" from a "trouble state."
In the second embodiment (FIG. 2), additional circuitry is added to the first embodiment such that the SMAS can interface with a "smoke detector loop" from the central alarm panel rather than a normally closed loop. In a "smoke detector loop" the central alarm panel recognizes an "alarm state" when the loop is shorted (or the loop resistance is very low). It recognizes a "trouble state" when there is a break in the loop. Consequently, this embodiment of the SMAS allows the alarm panel to distinguish these two states.
Another desirable feature of the SMAS is that it is operational even when the AC power to the smoke detectors is absent and the battery back ups are poorly charged.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic circuit diagram showing a typical simplified embodiment of the Fail Safe Sensitive Monitor And Signaler for Interconnect Lines of AC Powered Smoke Alarms with Battery Back-Up (SMAS) according to the present invention. Circuit 1 is shown connected to a central alarm panel 2 and the smoke alarm system formed by an interconnect loop 3,4,5 and at least one smoke detector 6. Additionally, an alarm state indicator 15 is connected to the central alarm panel 2.
FIG. 2 is a diagram similar to FIG. 1 showing a typical embodiment of the invention that includes additional circuitry and functions. The circuit 1' is shown connected to a central alarm panel 2', a smoke alarm loop-end of line resistor 16, an interconnect loop 3',4',5', and a plurality of smoke detectors 6'. Additionally, indicators for a "trouble state" 14' and an "alarm state" 15' are connected to the central alarm panel 2'.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to FIG. 1, the fail safe Sensitive Monitor And Signaler for interconnect lines of AC powered smoke alarms with battery backup (SMAS) circuit 1 interfaces with an external source of power 9,10 and two electronic loops--an alarm loop 7,8 and an interconnect loop 3,4,5.
The power and alarm loops come from a central alarm system panel 2. The power is DC and typically is supplied at 2D either from an electronic DC power supply or by a battery. The alarm loop, originating at 7,8 comprises a direct current source 2A, a current limiting series resistor 2B, and a current monitoring device 2C. Current in the loop 7,8,11B thus is limited in the panel 2, which is programmed to expect the loop to be normally closed at 11B. The processing is done using the keys 22A on the key pad 22. When the alarm loop 7,8,11B is open, the alarm system circuitry 2C in the panel 2 recognizes an "alarm state" and signals the user by turning on a horn a other audible or visible signaling device 15 shown here but not limited in location to the key pad 22. Opening of the loop can occur as a physical break in the loop or opening of the relay contacts 11B. Any condition that eliminates power to the relay coil 11A or lowers the power to the coil beyond what is needed to maintain closed relay contacts will result in open contacts at 11B and be perceived by the central alarm panel 2 as an "alarm state." Examples of such conditions include loss of power at 9,10 to the SMAS, a break in any line feeding power to the relay coil 11A, and reverse biasing of the switching diode 12.
The interconnect loop 3,4,5 is created by joining one end of an interconnect line 3 with a neutral line 4 via and end of line resistor 5 which also has a current limiting function. The interconnect line is one of three connections that can be made with the smoke detector 6. The other two connections are for supplying 110 volts AC to the detector. One of these connections (a black wire by convention--not shown) is "hot" and the other (white by convention 4) is neutral. In addition to being the 110 volt AC neutral line, the white line 4 is also paired with the interconnect line 3 such that DC voltage can be supplied via those two lines 3,4. Such voltage is supplied by the smoke detector 6 on the interconnect line (anode) 3 and neutral line (cathode) 4 when the detector 6 senses smoke. A plurality of detectors 6 (only one of which is shown in FIG. 1) can be interconnected in parallel using the neutral 4 and interconnect 3 lines with the result that when one alarm 6 sounds because smoke has been detected, the DC voltage on the interconnect 3-neutral 4 line results in all interconnected detectors 6 sounding an alarm.
The interconnect loop has power applied from the SMAS at 3,4. The power, limited by a voltage divider 13 (comprising a variable potentiometer 13A,13B in FIG. 1), is insufficient to trigger the detectors 6 to sound an alarm. Current from the voltage divider 13 leaves the SMAS 1 at 3 to circulate through the interconnect loop 3,4,5 and then returns to the SMAS 1 at 5. It then circulates through the previously described relay coil 11A, then a switching diode 12, then back to the cathode 9 of the external power.
When the smoke detector 6 senses smoke, it applies power to the interconnect line as described above and reverse biases the switching diode 12 resulting in loss of power to the relay 11A and opening of the alarm loop 7,8,11B at 11B. Tolerances on the circuit are very tight. The voltage on the interconnect line in the described embodiment prototyped with the 86RAC smoke detector (manufactured by BRK Electronics of Aurora, Ill.) must be maintained between approximately 1.75 and 1.95 volts DC. The circuit design also allows for a very depleted 9 volt battery to still be effective in triggering an alarm. As little as 1.1 milliwatt at 2 volts (direct current) is capable of reverse biasing the switching diode.
Typically mounted on an etched printed circuit board in a plastic enclosure (not shown), the circuit of FIG. 1, independent of said enclosure, connectors for interfacing the two loops and power, and the end of line resistor 5, consists of only three components: the potentiometer 13, the relay 11, and the switching diode 12. A prototype has been constructed and operates as expected.
Also described in the original specification of the parent application are optional part substitutions. These part substitutions are shown in FIG. 2. A prototype was constructed using these substitutions with the above described alarm panel and accessories. It also operated as expected.
The first substitution of parts provides a more user friendly and better controlled power supply to the interconnect loop. The voltage divider in FIG. 1 is a variable potentiometer 13 that may be adjusted for a given external power supply 9,10. In FIG. 2 the variable potentiometer 13 is replaced by a pair of 1% tolerance fixed value resistors 13A' and 13B' drawing power from a narrow voltage range solid state voltage regulator 19 with a rectifier diode 20 protecting its output.
The second substitution is replacement of the standard mechanical relay 11 of FIG. 1 with a photovoltaic relay 11'. Thus the coil 11A is replaced by a light-emitting diode 11A', and the relay contacts 11B are replaced by integrated circuitry that couples an array of photo diodes to MOSFET (metal oxide semiconductor field effect transistor) circuitry as represented at 11B' by a MOSFET like symbol. As the light-emitting diode 11A' in this relay analogue cannot tolerate the reverse biasing voltage used in this circuit, it cannot be used as a switching diode. Thus, the switching diode 12' is added in series.
In embodiments of the type shown in FIG. 2, there is an addition of circuitry such that the SMAS 1' can be connected to a "smoke detector loop" (from the central alarm panel) rather than a normally closed loop. A "smoke detector loop" is one that is monitored by the central alarm panel 2' in a way that distinguishes an "alarm state" from a "trouble state." An "alarm state" is present when the smoke detector senses smoke. A "trouble state" is present when the loop is open or has high impedance.
As with the "normally closed loop," described above, the "smoke detector loop," originating at 7', 8' is a current source 2A' generated by and monitored by the central alarm system panel 2'. Current in the loop7',16, 11B',8' is limited by the resistor 2B' in the panel 2' and is also limited by an end of line resistor 16 external to the panel 2'. This resistor 16 closes the end of the "smoke detector loop" in a manner similar to the resistor 5' closing the interconnect loop at 3',4'. In a "no alarm, no trouble" state, the central alarm panel 2C' expects a defined current range to be circulating through the loop. In an "alarm state," the panel 2C' expects to see a marked increase in current flow through the loop 7',16,11B',8' because in prior art systems, in an "alarm state," the loop would have been shorted by a DC smoke detector when it sensed smoke. It should be noted that the smoke detectors 6' in FIG. 2 can not short a loop. Instead, their way of indicating an alarm condition is by putting a voltage on an interconnect line. Thus, the SMAS translates that interconnect voltage into a short on the loop 7', 16,11B'8' to mimic the action of a DC smoke detector. In an "alarm state," the panel. 2C' signals the user by turning on a horn or other audible or visible signaling device 15.
These devices may stand alone or, as shown in the figures, 14', 15' be incorporated in a remote keypad that is used to program the central alarm system panel 2C'. Typically the keypad will have light emitting diodes with adjacent labels to indicate what state or states are present as well as audible signals specific for a given state. Additionally, liquid crystal displays may be used to provide alphanumeric information on the status of the system. Installation manuals for each system type specify the possible array of signaling devices for a given system.
In a "trouble state," the central alarm panel expects to see no current circulating in the loop because the loop has been mechanically opened or otherwise affected in a way that produces high impedance in the loop. In such a state, the panel 2C' signals the user by turning on a horn or other audible or visible signaling device 14, which provides a signal that is easily recognized as different from that emanating from the signaling device 15 which indicates an "alarm state."
These devices may stand alone or, as shown in the figures, 14',15', be incorporated in a remote keypad that is used to program the central alarm system panel 2C'. Typically the keypad will have light emitting diodes with adjacent labels to indicate what state or states are present as well as audible signals specific for a given state. Additionally, liquid crystal displays may be used to provide alphanumeric information on the status of the system. Installation manuals for each system type specify the possible array of signaling devices for a given system.
In an "alarm state" or in a "trouble state," the circuitry in FIG. 1 produces the equivalent of open relay contacts at 11B' that is recognized by the alarm panel as an "alarm state," the only altered state recognizable by a normally closed loop. Thus additional circuitry is added in FIG. 2 so that a "smoke detector loop" can be used to distinguish "alarm" and "trouble" states. In brief, an "alarm state" in detector(s) 6' will result in at least nearly shorting the "smoke detector loop" 7',16,11B' 8' by a relay analogue 17. In a "trouble state," relay 11' will open the loop. In practice, powering of the relay analogue 17 results in a loop resistance of approximately 20 ohms. Since the central alarm panel used in testing recognizes an "alarm state" when the loop resistance is below 100 ohms, 20 OHMS of loop resistance is sufficient to trigger an "alarm state" in the central alarm panel.
The additional circuitry shown in FIG. 2 includes a resistor 16, a relay analogue 17 similar to the relay analogue 11', a diode 18, and a resistor 21. The operation of this additional circuitry is as follows.
The loop from the central alarm panel 7', 8' is a "smoke detector loop" that requires an end of line resistor 16 for monitoring purposes as described above. As the value of this resistor 16 depends upon the characteristics of the central alarm panel 2', contacts are provided on the SMAS 1' for installation of this resistor 16 external to the SMAS 1'. As in FIG. 1, in a "no alarm, no trouble state" current from the SMAS 1' circulates through an interconnect loop 3', 4', 5', through a light-emitting diode 11A' of the relay 11', and back to the cathode 9' of the external power 9', 10'. This current is sufficient to power the relay 11' and maintain a closed smoke alarm loop with a fixed amount of loop resistance 16. At the same time, current from the voltage divider 13A', 13B' circulates through a light-emitting diode 17A of the second relay analogue 17. This current is not sufficient to power the second relay analogue 17 that would effectively short the "smokedetector loop" 7',8' if the relay analogue 17 were sufficiently powered.
As in FIG. 1, a break in the alarm or interconnect loops or loss of power to the SMAS results in insufficient power to the relay 11', and the "smoke detector loop" is opened. The central alarm panel 2C' recognizes this as a "trouble state" and signals the user via an audible and/or visual indicator 14'.
In an "alarm state" the smoke detector(s) 6' apply a potential difference to the interconnect loop such that the switching diode 12' is reverse biased. If the relay 17 were not functional, a "trouble state" would ensue from the opening of the alarm loop by the relay 11'. If the relay 17 is functional, in an "alarm state," its light-emitting diode 17A will receive sufficient power from the smoke detectors 6' via the interconnect 3' and neutral 4' lines to lower the resistance on the alarm loop 7',16,11B',8' to a point that an "alarm state" would be perceived by the central alarm panel 2C', and the user would be signaled via an audible and/or visual indicator 15'. The resistor 21 limits the current to the relay analogue 17 so that in a "no alarm state" it will not receive current sufficient to produce an "alarm state" signal.
A prototype of this second embodiment as in FIG. 2 was constructed using a professionally made printed circuit board with components wave soldered. It was subsequently encapsulated in epoxy potting compound and operates as expected. The central alarm system panel used in the prototype is a Model PC1575 manufactured by Digital Security Controls Ltd. (Canada). Programming of this panel was done manually using the keypad Model PC1575RK (sic) supplied with the panel. The panel was powered with a step-down transformer having an external battery backup.
While the forms of the invention herein disclosed constitute currently preferred embodiments, many others are possible. It is not intended herein to mention all of the possible equivalent forms or ramifications of the invention. It is to be understood that the terms used herein are merely descriptive rather than limiting, and that various changes may be made without departing from the spirit and scope of the invention.
Of course the detectors 6,6' need not be limited to smoke detectors. They may, for example, comprise detectors for indicating the presence of carbon monoxide, radon, or other gaseous, liquid, or solid matter, including human beings or other life. In fact the detectors 6,6' may comprise means for providing an electrical potential difference at 3,4 or 3',4' in the presence of any predetermined detectible condition, and the following claims are to be construed accordingly. | Typical apparatus according to the present invention for detecting a predetermined type of condition (such as the presence of smoke) at a given location and providing an indication (typically audible and/or visible) of the presence of such condition, comprises an electrical detector responsive to the type of condition, for providing a potential difference of at least a predetermined amount between two predetermined points; first circuitry for connecting at least a substantial fraction of the potential difference to an electrical relay or relay analogue in the apparatus so as to provide a predetermined first indication; and second circuitry responsive to a condition in the detector or in the first circuitry that is outside of a predetermined range, and thus of possible detriment to the optimum performance of the apparatus, to provide a predetermined indication. Typically the first circuitry provides one indication concerning the presence or absence of smoke and the second circuitry provides a different indication concerning the presence or absence of possible trouble in the apparatus. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for reducing the restart pressure of streams selected from waxy crude oils, water-in-crude emulsions and dispersions of hydrocarbon hydrates, at least partially structured.
2. Description of the Art
One of the aspects to be carefully taken into consideration during the development of an oil production plant, is to ensure a continuous and stationary flow of crude oil inside the ducts. Operation stops can occur for several reasons, from simple maintenance to unexpected situations (for example due to a pig block, or a breakdown in a plant for the treatment of crude oil). During the engineering stage, it is therefore necessary to carefully analyse all possible problems which can arise at the restart of production, above all for offshore pipe-lines (underwater pipes) which, due to their locations, are more difficult to have access to and are characterized by low temperature conditions (0-10° C.).
Structured system means a physical system having a high coordination between its units (molecules or aggregates of soluble or non-soluble molecules, also very extensive) produced by chemical and/or physical bonds. The coordination level depends on the number and strength of the bonds between the structural units. This situation generates an organization that resembles a network including the whole volume occupied by the system (for example a three-dimensional network of regular or amorphous crystals, of a gel, etc.).
The structural level of a substance can be expressed in terms of “yield stress”, defined as the minimum stress (power per surface unit) to be applied to the substance so that this shows a permanent deformation and begins to flow. The “yield stress” is consequently a parameter strongly correlated with the stress (pressure difference at the ends of the pipe) to be applied to allow a stream to pass from a state of stillness to one of motion. The “yield stress” of a substance can be measured experimentally, for example by means of rotational rheometers. Other rheological parameters which allow the structural level of a substance to be quantified are the tensile modulus (G′) and the dissipative modulus (G″). These material parameters are obtained through rheological measurements, effected in a low amplitude oscillatory system. These measurements consist in applying a sinusoidal deformation of variable (and/or constant) frequency and a sufficiently low amplitude as to not disturb the system (“An introduction to Rheology” H. A. Barnes, J. F. Hutton and K. Walters, Elsevier Science Publishers B. V., 1989). The response of the system to the stress will be a sinusoidal signal, out-of-phase with respect to that applied. From measuring the response signal intensity and from the entity of the phase displacement, it is possible to calculate two rheological parameters G′ and G″ which represent the elastic component (solid-type behaviour) and dissipative (liquid behaviour) of the system, respectively. In particular, the tensile modulus represents a parameter which quantitatively expresses (together with the viscosity and the “yield stress”) the structuring degree of the stream considered (“Applied Fluid Rheology”, J. Ferguson, Z. Kemblowski, Elsevier Science Publisher LTD, 1991).
As is well known from literature (A. Uhde, G. Kopp, “Pipeline problems resulting from the handling of waxy crudes”, Journal of the Institute of Petroleum, vol. 57, number 554, 1971; C. Chang, D. V. Boger and Q. D. Nguyen, “Influence of thermal history on the waxy structure of statically cooled waxy crude oil”, SPE Journal 5 (2) June 2000; C. Chang, D. V. Boger “The yielding of waxy crude oils”, Ind. Eng. Chem. Res. 37, 1551-1559. 1998), during the progressive structuring of a fluid put in a state of rest, the “yield stress”, the viscosity and the G′ and G″ modules change proportionally to each other. The two quantities are equivalent material parameters in representing the structuring degree of the stream. With reference to the problems relating to the restart of the stream, however, “yield stress” is the most representative parameter, as it directly expresses the threshold value necessary for generating the flow. Consequently, in the following text, reference will mainly be made to the “yield stress”.
The above-mentioned streams are considered separately hereunder, with the purpose of outlining the specific problems relating to the restart of the duct.
Waxy Crude Oils
The presence of n-paraffins in crude oil can generate wax crystals at temperatures lower than a characteristic temperature of each crude oil, called WAT (Wax Appearance Temperature), which can be defined as the temperature at which the first crystals are observed. The Pour Point (PP), defined as the temperature below which an oil cannot flow under the force of gravity alone, due to its transformation into gel (solid-type behaviour), is found at temperatures lower than the WAT. In operative terms, the PP is measured according to the regulation ASTM D-97 and represents an empirical evaluation of the yield stress.
The WAT of many crude oils, like the PP, is higher than the temperature normally found in deep seabeds (2-3° C.) or in some geographical areas where onshore pipelines are installed.
Under flow-stop conditions, the gelation of crude oil at temperatures lower than the PP, creates a mass of gelled crude oil in a wide tract of the duct, which can generate serious drawbacks during the flow restart operations.
Industry is currently trying to prevent the problem of gelation by:
i) the installation, when possible, of lines and pumps capable of ensuring the necessary pressure in the case of a long and unexpected stoppage of the plant; ii) the running of the plant, so as to reduce unexpected stoppages; iii) the use of heated or insulated ducts, so as to reduce the heat exchange; iv) the use of chemical additives and/or solvents which reduce the tendency or the rate of gelation of waxy crude oils, by improving the properties of the material in terms of viscosity and yield stress.
All these approaches however have various efficacy limitations, mainly in cases of unexpected and prolonged plant-stoppages, or they can be economically unsustainable for the development of the field (for ex. the use of heated pipes), due to the high investment and running costs. Furthermore, the problem can arise in fields already in production, which have been engineered without considering the possibility of the problem arising.
Water-in-Crude Emulsions
The formation of water-in-crude emulsions (defined as emulsions of the W/O type) creates a significant increase in viscosity with respect to the viscosity of the crude oil as such. The increase in viscosity of the water-in-crude emulsion is a function of the volume fraction of the water contained in dispersed form and can be described through relationships such as:
η relative ≡η/η S =(1+2.5φ+6.2φ 2 +. . .)
wherein η is the viscosity of the emulsion (W/o), η S is the viscosity of the continuous phase (oil) alone, η relative is called relative viscosity and φ is the volume fraction of the dispersed phase (water).
It is also known that the increase in viscosity, being the same the fraction φ of the dispersed phase, also strongly depends on the particle-size distribution of the latter and on the nature of the interaction between the continuous phase (oil) and the dispersed phase. In the case of W/O emulsions formed with waxy crude oils, there is experimental and field evidence of significant and important increases in the relative viscosity and yield stress with a decrease in the temperature below the WAT of the oil. Under such conditions, serious problems can arise in the emulsion restart.
It is therefore necessary to intervene to reduce the viscosity and yield stress and consequently the restart pressure of these streams.
Dispersions of Hydrocarbon Hydrates
Hydrates are solutions in solid phase of water and other chemical species called guest molecules. The crystalline structure is produced by cages of water molecules (hence the name of clathrate products), in which the guest molecules are kept in a non-stoichiometric manner.
Hydrates can be formed at temperatures significantly higher than the formation temperature of water ice. For example, a 95:5 mixture of water and C 1 :C 3 gaseous hydrocarbons, can form solid hydrates at temperatures slightly below 9° C. and at a pressure of 20 bar. It should be remembered that these operative conditions are not verified solely for particular climatic conditions (deep water and geographical positions with cold climates), but also in the presence of multiphase transport lines with high pressure drops: under these conditions, in fact, hydrocarbon gases generate deep cooling as a result of the Joule-Thomson effect.
The formation of hydrates is a relevant problem, as they can completely obstruct the production lines and, due to the complexity and dangerousness of the removal operations, can cause considerable delays in the production of hydrocarbons and consequently high economical losses.
The most common prevention systems of the formation of hydrates require the use of thermal inhibitors, such as methanol and glycol which, when added to the stream in concentrations equal to about 20% by volume with respect to the water present, lower the formation temperature of hydrates to values outside the operating range. This technique has drawbacks, however, in various production scenarios, among which deep water, due to the anti-economical treatment in the case of high volume fractions of water produced, and the necessity of minimizing plants for the separation and recycling of the thermodynamic inhibitor, mainly in deep water reserves.
Other prevention systems consist of kinetic inhibitors and anti-agglomerating products, prepared to be used at low dosages and disposable. These are chemical products capable of delaying the formation of hydrates or of mitigating their effects by forming hydrate dispersions less compact than the solid which would be formed without the addition of additives and therefore more easily pumpable to the pipeline. Kinetic inhibitors prove to be more advantageous with respect to the conventional techniques (isolated and/or heated lines and the use of methanol or glycol), both in terms of investment and operative costs, but they represent a technology which still has a poorly consolidated efficacy. It should also be noted that, in the presence of hydrate dispersions (formed thanks to the action of anti-agglomerating additives), long flow stoppages (several hours) can lead to significant increases in viscosity and yield stress in the same dispersions, as a result of which serious problems can arise at the re-start. Even in the presence of anti-agglomeration additives, it is therefore important to intervene to reduce the viscosity and re-start pressure.
SUMMARY OF THE INVENTION
A stream (whether consisting of waxy crudes, water/crude emulsions or hydrate dispersions, structured or partially structured) maintained under rest conditions and subject to cooling (until a fixed temperature, lower than the starting value, is reached) shows a progressive increase in the viscosity and yield stress which, after a time varying from a few hours to several days, reaches extreme values, characteristic of each stream.
It has been found that it is possible to facilitate the re-start of this stream by subjecting it to suitable mechanical stress, preferably induced by sound or ultrasound or infra-sound frequencies.
In this way, it is possible to reduce, even by a few orders of magnitude, the viscosity and yield stress of the stream with respect to the values obtained in the absence of said stress. Furthermore, if the mechanical stress is applied during a sufficient period of time and intensity, the phenomenon remains even after interrupting the application, and the extreme viscosity and yield stress levels of the stream prove to be lower (at the reference temperature and pressure) with respect to those that would be reached in the absence of the above-mentioned stress.
The latter is the most significant element of the present invention: the fact that the reduction in the extreme viscosity and yield stress caused on the stream by the stress applied proves to be irreversible, provided the stress is applied for a sufficiently long time and has an intensity higher than a threshold characteristic of each stream.
The process, object of the present invention, for reducing the re-start pressure of streams selected from waxy crudes, water-in-crude emulsions and dispersions of hydrocarbon hydrates, at least partially structured, is characterized in that it applies, under flow-stop conditions, a mechanic stress on said stream, having:
for waxy crude oils and water-in-crude emulsions, temperatures lower than WAT (Wax Appearance Temperature), possibly, for these emulsions, lower than the Pour Point (PP); for dispersions of hydrocarbon hydrates, at temperatures lower than the formation temperatures of said hydrates and at pressures higher than the formation pressure of said hydrates.
The intensity of the mechanical stress, regardless of its origin, is expressed hereunder by indicating the wall strain (shear stress) caused thereby, progressively along the pipeline during wave propagation.
Mechanical stress can be effected with different methods, among which flow rate and pressure waves, shear stress, gas insufflation, mixing with a suitable liquid having a different density with respect to the stream or shaking.
The mechanical stress can also be induced by sound, ultra-sound or infra-sound waves, which can be obtained through flow rate and pressure waves.
The first two types of stress represent examples of waves travelling along the pipeline and progressively exerting, on all the points of the fluid, a mechanical stress equivalent to wall stress. The latter magnitude is in direct correlation with the stress applied to a fluid by a rheometer, whether it be stress control or deformation. Therefore the quantitative information on the properties and behaviour of the streams in said measurement equipment can be expressed directly in the form of the intensity of the flow rate and pressure waves to be applied to the stream to obtain the desired stress values to the walls.
The desired effect can also be obtained by means of other types of stress, such as gas insufflation or mixing with another means having a different density. Their application modes however cannot be expressed directly in the form of a wall stress and therefore do not allow an “a priori” evaluation of their efficacy. They must consequently be applied on an empirical basis.
Hereinafter, the structure level (yield stress and viscosity) of the stream before the plant stoppage will be indicated with τ(t=0) and η(t=0) (i.e. at time t=0, under typical conditions of T and P of the stream). After the stream stoppage, the flow is subjected to a progressive structuring process which causes the yield stress, in a time t max , depending on the stream, to change from τ(t=0) to a maximum value, also typical of each stream, hereinafter named τ(t max ).
The time t max for reaching the maximum structuring degree depends not only on the stream, but also on the evolution with time of the temperature and pressure. In general, an increase in the viscosity η(t) and yield stress τ(t) corresponds to a decrease in a stream temperature. Even after reaching the equilibrium temperature however, the structuring of the stream can increase with time, due to internal reorganization processes, until characteristic extreme values called τ(t max ) and η(t max ) are reached. For example, waxy crude oils, initially thermostat-regulated at a temperature T 1 higher than the PP of 30° C. and, subsequently, brought in 0.2 hr, to the temperature T 2 lower than the PP of 6° C., have reached the maximum structuring after 4 hours at the uniform temperature of T 2 . Consequently, in these particular cases, t max =4.2 h.
BRIEF DESRIPTION OF THE DRAWINGS
FIG. 1 is a stress graph for the reference process;
FIG. 2 is a stress graph for a waxy crude stream;
FIG. 3 is a stress graph for a water-in-crude emulsion stream;
FIG. 4 is a stress graph for a hydrate dispersion stream;
FIG. 5 is a graph showing variations in tensile modulus;
FIG. 6 is a graph of temperature variations in the tensile modulus of waxy crude;
FIG. 7 is a microphotograph under polarized light of paraffin crystals in a crude cooled through two different thermal profiles;
FIG. 8 is a graph showing stress variations in the viscosity of a waxy crude;
FIG. 9 is a graph showing shear stress variations in the viscosity of a waxy crude;
FIG. 10 is a graph showing stress variations in the viscosity of a waxy crude after one hour;
FIG. 11 is a graph showing stress variations in the viscosity of a waxy crude after four hours;
FIG. 12 is a graph showing frequency variation in tensile modulus in a waxy crude after four hours;
FIG. 13 is a graph showing frequency variation in tensile modulus in a waxy crude subjected to triangular sequences of shear rates, after four hours;
FIG. 14 is a graph showing time variation in tensile modulus in a waxy crude after four hours;
FIG. 15 is a graph showing frequency variation in tensile modulus in a waxy crude subjected to a constant shear rate, after four hours;
FIG. 16 is a schematic illustration of the equipment for generating the stress object of the invention;
FIG. 17 is a graph showing the instant flow rate trend produced using the equipment of FIG. 16 ;
FIG. 18 is a graph showing the wave rebound time on the other end of the duct;
FIG. 19 is a graph showing the maximum wall stress along the duct;
FIG. 20 is a graph showing the instant pressure evolution produced by the flow rate transient of FIG. 17 ;
FIG. 21 is a graph showing rebounds of the pressure peak of FIG. 20 ;
FIG. 22 is a graph showing changes in pressure with changes in duct inner diameter;
FIG. 23 is a graph showing changes in pressure with localized restrictions in duct inner diameter;
FIG. 24 is a graph showing changes in pressure with changes in viscosity;
FIG. 25 is a graph showing rebounds of changes in pressure with changes in viscosity;
FIG. 26 is a graph showing fading coefficient versus changes in viscosity; and
FIG. 27 is a graph showing peak amplitude in rebounds.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The reference process is shown in FIG. 1 .
The stress must be applied after the stream stoppage (t≧0) and before the stream reaches the maximum structuring degree indicated with τ(t max ) and η(t max ), due to the flow stoppage.
The energy to be supplied for irreversibly applying stress to the structure of the stream, changes, depending on its structuring level, and, in particular, increases with an increase in the structuring level. If the intensity of the stress applied is sufficient for the structuring conditions of the stream, then the structuring achieved by the stream due to the stress will be permanently lower than that which it would have reached in the absence of stress.
More specifically, by underlining the structure level τ (t) and η (t) of the stream subjected to stress from the time t 1 ≧0 to the time t 2 , we then have:
τ ( t≧t 2 )<τ( t )
η ( t≧t 2 )<η( t ).
In particular, the maximum reduction effect of the structuring can be obtained by applying the stress with continuity during times ranging from the stoppage time of the flow and t max or, preferably, the moment of re-establishing the flow conditions.
The stress must have a sufficient intensity with respect to the structuring degree of the stream at the initial time of application t 1 , in order to produce a permanent reduction in the structuring level of the stream.
The intensity of the mechanical stress, regardless of its origin, is expressed hereafter by indicating the strain to the wall progressively caused thereby along the pipeline during the wave propagation.
The stress applied has an intensity sufficient for producing a permanent reduction in the structuring of the stream (viscosity and yield stress) when the wall strain is 15% higher, preferably 20% higher and less than 40%, than the specific yield stress of the stream at the starting moment of said stress.
Examples of stress application to each type of stream for obtaining the effect claimed, are provided hereunder.
For the waxy crude stream: FIG. 2 . For the water-in-crude emulsion stream: FIG. 3 . For the hydrate dispersion stream: FIG. 4 .
EXAMPLES FOR WAXY CRUDES
A reference waxy crude (paraffin) called A, was considered for studying the rheological properties of the paraffin gel (waxy) at a low temperature. The rheological properties of said crude were studied within a temperature range of 40° C. to 15° C. The minimum temperature (15° C.) is below the Pour Point of the crude (21° C. according to the regulation ASTM D97) thus ensuring the formation of a gel, representative of the specific phenomenon of interest.
The results of the rheological experimentation carried out on the crude A are indicated below. The results are proposed with the criteria of evidencing the effects of the main variables identified (cooling rate, minimum temperature and residence time at this temperature) on the consistency of the wax gel and then evaluating the reduction effect (irreversible) of the gel structuring (viscosity and yield stress) due to the application of shear stress.
In addition to the viscosity and yield stress, the tensile modulus (G′) and dissipative modulus (G″) values are indicated in this experimentation, effected using a stress control rheometer of Rheometric Scientific (DSR 200 ). This parameter will be used hereinafter together with the viscosity and “yield” for quantifying the structuring degree of the stream in question.
Influence of the Cooling Rate on the Consistency of the Wax Gel.
FIG. 5 shows the variations of G′ (tensile modulus) and G″ (dissipative modulus) when the temperature changes from 40° C. to 15° C. obtained by applying different cooling rates, from 0.05° C./min to 2° C. min. The measurements were taken at a constant frequency of 1 Hz and at a deformation range (0.15%) within the linear visco-elasticity range (“An introduction to Rheology”, H. A. Barnes, J. F. Hutton and K. Walters, Elsevier Science Publisher B. V., 1989).
The experimental results obtained (se FIG. 5 ) show that the lower the cooling rate the higher the G′ value is (and therefore of the gel consistency) measured at the minimum temperature of 15° C. This result is maintained with time, and this is a relevant aspect. FIG. 6 shows, as a confirmation of the above, the variations of G′ in relation to the time (still at a constant frequency of 1 Hz and a small deformation amplitude) at the minimum temperature of 15° C. for the samples cooled down at different rates. Samples were monitored for over 16 hours after they had been cooled to 15° C.
The differences between the values of the G′ modulus (and therefore of the consistency of the gel formed), measured at the end of the monitoring period of 16 hours, are comparable with the differences measured at the end of the cooling obtained with different thermal rates: the system memorizes the thermal rate with which it was cooled, in the structural characteristics of the gel at equilibrium.
The above-mentioned figures indicate the G′ profiles only, as the G″ profiles show the same behaviour at different levels.
A display of the structures formed following cooling to 15° C. through different thermal rates and after waiting 4 hours for thermal equilibrium, was obtained by means of optical microscopy under polarized light (see FIG. 7 ): by applying a very low rate (0.05° C./min), the paraffin crystals have time to organize themselves in correspondence with nucleation centres, forming “islands” of larger dimensions with respect to those obtained at a much higher rate (2° C./min) where the system has no time for organizing itself. In this latter case the network formed is much more uniform but thinner and, above all, mechanically weaker. This is the reason why the tensile modulus value and, therefore the viscosity and yield stress of the system at equilibrium, obtained by means of a lower cooling rate, is higher than that obtained at a higher rate.
Influence of the Minimum Temperature on the Consistency of the Wax Gel.
Viscosity measurements were carried out on the basis of the above observations, at temperatures ranging from 40° C. to 15° C., in relation to the stress applied. The purpose was to evaluate the viscosity and yield stress variation as a function of the temperature.
The crude under consideration (A), see FIG. 8 , shows, at temperatures ranging from 40° C. to 30° C., a sharp transition between a Newtonian behaviour (constant viscosity and regardless of the stress applied and yield stress null) and non-Newtonian of the pseudo-plastic type (the viscosity decreases with an increase in the stress applied and the yield stress has positive values). The yield stress value is obtained from the viscosity vs stress curves shown in FIG. 8 , as the stress at which the viscosity has a sharp reduction (2 or 4 orders of magnitude). Table I shows the dependency of the yield stress, the viscosity at zero shear and the viscosity at high shear (η ∞ ) on the temperature for crude A. FIG. 9 shows a typical profile viscosity vs stress indicating the parameters which characterize the gel state, i.e. τ y , η 0 and η ∞ .
TABLE I
T (° C.)
τ y [Pa]
η 0 [Pa · s]
η ∞ [Pa · s]
40
0
0.065
0.065
30
0.2
3460
0.103
25
1.7
5890
0.136
20
18.6
3.55E+5
0.233
15
63.4
3.31E+6
0.304
10
233
3.54E+7
0.304
Influence of the Residence Time (Soak Time) on the Consistency of the Wax Gel.
The effect of the soak time was evaluated on the consistency of the wax gel at temperatures of 15° C. and 20° C.
The result of the experimentation shows that with an increase in the soak time at a certain temperature, there is an increase of the gel consistency (increase in the yield stress value). FIGS. 10 and 11 show the flow curves obtained by imposing a waiting time of 1 and 4 hours; the relevant yield stress values are shown in TAB II.
Significant increases in the gel consistency were no longer measured for waiting times of over 4 hours. Also in this case, it can assumed that the effect of the soak time on the gel consistency is reduced with a decrease in the equilibrium temperature.
TABLE II T [° C.] τ y after 1 hr [Pa] τ y after 4 hr [Pa] 20 10 20 15 54 68
Once the “fundamental rheological” behaviour of the crude with a decrease in temperature had been identified, the possibility of intervention on the formation kinetics of the wax gel, through mechanical stress, was evaluated, in order to reduce its consistency at thermal equilibrium.
Example 1
Influence of the Shear History on the Wax Gel Consistency.
After verifying that after 4 hr at 15° C. of the crude A, the gel formed does not show any signs of further increase in its consistency (G′ constant and yield stress constant under these conditions) the influences were evaluated of suitable stress on the tensile modulus G′ and of the yield stress of the gelled crude. Different shear histories to which the gel was subjected at a temperature of 15° C. are indicated below.
i) Unperturbed Gel at Equilibrium
A measurement was effected on the crude cooled to 15° C. and left unperturbed for 4 hours, at a low shear amplitude, of the modules G′ and G″ with the variation in frequency (see FIG. 12 ). Under these conditions, the gel shows a module G′ value at 1 Hz (6.28 rad/s) equal to 4,700 Pa and a yield stress value equal to 63.4 Pa. These parameters represent the measurement of the consistency degree of the gel of crude A obtained under unperturbed conditions at 15° C.
ii) De-structured Gel at Equilibrium
A rate sweep sequence (from 0.1 s −1 to 1000 s −1 ) is applied to the crude gelled in item i), it is then left to restructure for 4 hours at 15° C., following the variation of G′ over a period of time. Once equilibrium has been reached (G′ reaches a plateau value with respect to the time), a measurement in oscillatory regime is carried out, at a small shear amplitude, to measure G′ and G″ with the variation in the frequency (see FIG. 13 ). The result of this measurement is a G′ value equal to 1200 Pa and this means, when compared with the unperturbed gel values at equilibrium, a reduction of about 70%. It should be noted that the value of G′, during the time the shear is applied, drops by 1-2 orders of magnitude; the energy required for moving the gelled crude is therefore minimum during and immediately after the application of the mechanical stress.
iii) Perturbed Gel During Cooling:
The crude is subjected to shaking during cooling from 40° C. to 15° C. Two different stress rates were applied in order to obtain the shaking: 1 s −1 and 50 s −1 . Once the temperature of 15° C. has been reached, the sample is left to restructure for four hours, following the variation of G′ with time ( FIGS. 14 and 15 ). The result of this measurement shows an average value of the module G′ equal to 1700 Pa if the cooling was effected by shaking at a shear rate of 1 s −1 and 1500 Pa, if the cooling was effected by shaking at a shear rate of 50 s −1 . By comparing these values with those of the unperturbed gel at equilibrium, a reduction of about 70% is still observed. Table III shows the results relating to the influence of the different stress histories on the consistency degree of the gel, expressed in terms of tensile module G′ and yield stress, compared with the values measured of the unperturbed system (percentage variation).
TABLE III
G′ [Pa]
G′ [Pa]
G′ [Pa] after
after cooling
after cooling
Unperturbed
sequence rate
effected with shear
effected with shear
G′ [Pa]
(see text)
rate of 1 s −1
rate of 50 s −1
4700
1200
1700
1500
yield stress
yield stress [Pa]
yield stress [Pa]
Unperturbed
[Pa] after
after cooling
after cooling
yield stress
rate sequence
effected with shear
effected with shear
[Pa]
(see text)
rate of 1 s −1
rate of 50 s −1
68
10
27.2
23.8
EXAMPLES FOR WATER/CRUDE EMULSIONS
A reference crude called B, emulsified with water percentages ranging from 1% to 2%, was considered for studying the rheological properties of a water-in-crude emulsion. The rheological properties of said emulsion were studied within a temperature range of 40 to 15° C. The minimum temperature considered (14° C.) proved to be above the crude Pour Point temperature (−6° C.) (determined following the regulation ASTM D97): at this temperature the formation is measured of a particularly viscous gel, and this justifies the considerable pumping problems in the plant.
The results of the rheological experimentation on the emulsion of crude B in water are indicated below. The results are shown in order to demonstrate the influences of the main variables (minimum temperature, residence time) on the consistency of the crude-in-water emulsion.
Example
Influence of the Shear History on the Consistency of the Water-in-crude Emulsion.
Having verified that, after leaving the crude B emulsion at 12.5° C. for 3 hours, the gel which was formed does not show any signs of a further increase in the consistency (G′ constant and yield stress constant under said conditions), the influence of suitable “shear/stress” histories was evaluated on the values of the tensile module G′ and yield stress of the gelled crude. Several shear histories are indicated below, at which the gel was subjected at a minimum temperature of 15° C.
i) Unperturbed Gel at Equilibrium.
A measurement in an oscillatory regime, at a low shear amplitude was effected on the water-in-crude emulsion, which was cooled to 15° C. and left unperturbed for 4 hours, to measure the modules G′ and G″ with the variation in frequency. Under these conditions, the gel shows yield stress values equal to 250 Pa. This parameter represents the measurement of the consistency degree of the gel of the emulsified crude B obtained under unperturbed conditions at 15° C.
ii) De-structured Gel at Equilibrium
The gelled crude of item i), after being cooled to 15° C. and left unperturbed for 4 hours, is “de-structured” by applying a rate sweep sequence (from 0.1 s −1 to 1000 s −1 ), it is then left to restructure for 4 hours at 15° C., following the variation in G′ over a period of time. Once equilibrium has been reached (G′ reaches a plateau value with respect to the time), a measurement is carried out under stress control. The result of this measurement shows a yield stress value equal to 10 Pa which, compared to the values of the unperturbed gel at equilibrium, shows a reduction of about 98%; the energy required for moving the gelled crude is therefore minimum during and immediately after the application of the mechanical stress.
iii) Perturbed Gel During Cooling:
The crude undergoes shaking while it is cooled from 40 to 15° C. Two different shear rates were applied to obtain the shaking: 1 s −1 and 50 s −1 . Once the sample has reached a temperature of 15° C., it is left to restructure for 3 hours, following the viscosity variation with stress ( FIG. 10 ). The result of this measurement shows a yield stress value equal to 1 Pa, if the cooling was effected by shaking with a shear rate of 1 s −1 , and 0 Pa if the cooling was effected by shaking with a shear rate of 50 s −1 . By comparing these values with those obtained on the unperturbed gel at equilibrium, a further reduction is observed equal to about 100%.
Table IV shows the results relating to the influence of the different shear histories on the consistency degree of the gel, expressed in terms of yield stress, by comparison with the values measured for the unperturbed system (percentage variation)
TABLE IV
Yield stress
yield stress [Pa]
Yield stress [Pa]
Unperturbed
[Pa] after
after cooling
after cooling
yield stress
rate sequence
effected with shear
effected with shear
[Pa]
(see text)
rate of 1 s −1
rate of 50 s −1
250
10
1
0
EXAMPLES FOR HYDRATE DISPERSIONS
A mixture of crude (crude C), water (20% volume) and methane was considered for studying the rheological properties of a dispersion of hydrates. This mix was studied by using a stress control rheometer (DSR 200 of Rheometric Scientific), equipped with a pressure cell capable of operating at up to 140 bar. The rheological characterization was carried out, with reference to the PVT data of the mix considered, at a pressure and temperature corresponding to the formation of the hydrate. The addition of an anti-agglomeration kinetic inhibitor (polyvinyl pyrrolidone, PVP) causes the formation of a dispersion of hydrates which, if left unperturbed at the formation temperature of the hydrates, increases its structuring degree, causing the blockage of the pipeline. It is therefore necessary to intervene using the techniques proposed for reducing the structuring degree (thus the viscosity and yield stress) of the dispersion.
Table V shows the results relating to the influence of the different shear histories on the gel consistency degree, expressed as yield stress, by comparison with the values measured for the unperturbed system (percentage variation).
TABLE V
Yield stress
yield stress [Pa]
Yield stress [Pa]
Unperturbed
[Pa] after
after cooling
after cooling
yield stress
rate sequence
effected with shear
effected with shear
[Pa]
(see text)
rate of 1 s −1
rate of 50 s −1
300
150
210
190
A method is now described, which can be used both for the stress of a liquid present in a pipeline, with the aim of irreversibly reducing its structuring, and for monitoring the structuring process, by measuring the instant viscosity of the liquid present in the pipeline and observing the possible formation of occlusions, restrictions or variations in the inner profile of the duct.
The method, which is a further object of the present invention, for measuring the profile of the inner diameter of a pipe and the instant viscosity of the fluid contained therein, is characterized in that it is carried out by the generation of sound or infra-sound waves produced, under flow absence conditions, by means of fast flow-rate transients, which are then registered by a suitable measuring device and processed, thus obtaining the profile of the inner diameter of the duct and the instant viscosity of the fluid contained therein.
In the text, repeated reference will be made to the illustrative situation of a duct 10 km long, having a uniform inner diameter of 0.3048 m (12″), uniform roughness equal to 20 microns and a variable altimetrical profile with horizontal and vertical tracts, as is typical of offshore transport lines. It should be noted that the inclination of the duct has no influence on the techniques illustrated which can therefore also be used in oil wells. A liquid is contained in the duct, having a bubble pressure equal to 70 bar and under single-phase non-structured conditions, a density and viscosity of 10 cP. The duct pressure is assumed as being higher than the bubble pressure in each point, to avoid the formation of pipe regions predominantly or completely occupied by the gas. The flow rate wave propagation rate and pressure is equal to 1,200 m/s.
The data are summarized in the following table.
Oil ρ density (constant along the duct) 0.85 g/cm 3 Viscosity under regular flow η conditions 10 mPas Bubble pressure 70 bar Duct Duct length L 10,000 m Inner diameter of the duct D 0.3048 m (12″) Roughness ε 20 microns Minimum pressure along the duct 80 bar Transients propagation rate c 1,200 m/s
Generation and measurement equipment of flow-rate transients.
The techniques for generating stress and for measuring the fluid structuring and duct diameter mentioned below, are based on the fact that a temporary discharge or admission of fluid in the duct generates a flow-rate and pressure wave which propagates along the duct at a rate approximately equal to the sound rate in the fluid. The exact propagation rate of the wave is, in fact, a function of several parameters, among which the sound rate in the non-confined fluid, the elasticity of the duct walls and the spectrum of the frequencies contained in the wave itself, and can be directly measured as illustrated below. Its a priori knowledge is therefore not necessary for the application of the method.
The temporary discharge of liquid can, for example, be caused, in a simple and reproducible way, with the help of the equipment shown in FIG. 16 . In said equipment, the sphere valve A, which is in contact with the duct fluid at the pressure P 1 , is rapidly opened, manually or through a fast-acting servomechanism, so as to put the duct in communication with the container having a volume V, which is at a pressure of P 2 , different from P 1 . The pressure difference therefore induces a liquid flow between the duct and the recipient which, in a time period of T, becomes completely exhausted due to the reestablishment of the equilibrium conditions P 1 and P 2 . The most common embodiment of this equipment contemplates the container C being at atmospheric pressure before the opening of valve A.
For the repetition of the generation of the transient, it is sufficient to close valve A, open valve B, restore the initial pressure conditions of the container between the two valves and to close valve B. In the most common embodiment, this operation consists of the complete or partial emptying of the container, allowing the fluid to be discharged.
For all the examples provided below, it is assumed that the volume of the container C is equal to 0.35 lt and that the flow-rate transient generated by the sudden opening of valve A is that illustrated in FIG. 17 .
The trend is representative of that obtained during the field test. A corresponding pressure transient, which can be registered by means of the system M for the pressure measurement, is associated with the flow-rate transient produced by the equipment of FIG. 16 . The presence of said pressure measurement system is not necessary for generating the de-structuring stress of the fluid, but it is necessary to register the pressure waves generated and their subsequent rebounds, with the aim of investigating the state of the fluid and the piping illustrated below.
The relative position of the measurement equipment M and the equipment for the generation of transients G, has no particular importance. Should the analysis methods described below be applied, it would be appropriate to have the apparatus G at a short distance (max. 5 meters) from the interception valve.
The frequency spectrum contained in the impulse generated by means of the equipment G is prevalenty lower than the sound limit (16 Hz) and therefore no audible sound is associated with the transient. Furthermore, the low frequency of the spectrum favours the high propagation distance of the signal, as the components having a progressively higher frequency diminish more and more rapidly with an increase in the distance covered, and limit the packet dispersion, maintaining the transient width unaltered for a long period of time. During tests on real pipelines, it was found out that the pressure wave generated by means of the equipment of FIG. 1 is capable of covering considerable distances (even many hundreds of Km) and of rebounding numerous times on the closed valves at the end of the pipeline, before completely diminishing due to dissipative phenomena.
The equipment of FIG. 1 can be used (1) for determining the real profile of inner diameters of the duct after its closing, (2) for applying the de-structuring stress object of the present invention, to the fluid (3) for repeatedly measuring the viscosity of the fluid contained, keeping the structuring process under control, (4) for detecting in real time the possible formation of solid matter in the pipeline, for example hydrates, or other important variations in the fluid properties. All this information can be obtained through the analysis procedures illustrated below.
First of all, a simulator will be described, capable of reproducing the behaviour of the flow-rate waves and pressure along the pipeline. The use of the simulator is not essential for the simple application of the destructuring stress, but it can significantly contribute to the measuring of the container C of the equipment for the transient generation, and it is essential for the application of the measurement methods of the diameter profile and viscosity. The optimal mode for the application of the de-structuring stress will be described further on. Finally, the procedures will be described for obtaining the diameter profile immediately after the closing of the duct, and for testing the fluid viscosity and other useful information for keeping the structuring process under control.
Flow-rate Wave Simulator and Pressure
A simulator is essential for a correct analysis of the pressure data recorded by the measurement system M (See FIG. 16 ) and must be capable of reproducing the pressure wave and flow-rate evolution, induced by the manoeuvre effected on the valve A of the equipment of FIG. 16 . The choice of simulator is not binding but, for the sake of clarity, one is described below which has proved to be capable of reproducing the desired phenomena.
The equations used by the simulator are the following:
δ p δ t + ρ c 2 δ v ⅆ ξ = 0 ( 1 ) ρ δ v δ t + δ p ⅆ ξ = - Φ ( v , D ) ( 2 ) Φ ( v , D ) = f ( Re ) D + ρ v v 2 ( 3 ) Re = v D ρ η ( 4 ) p = p ( t , ξ ) + ρ g z ( ξ ) ( 5 )
in which p(t,ξ) represents the difference between the pressure at position ξ along the pipeline and the corresponding hydrostatic pressure
p ( t ,ξ)= P real −ρg z (ξ) (6)
and:
ξ is the space curvilinear coordinate along the pipe D is the pipe diameter z(ξ) is the elevation of the point in position ξ Re is the Reynolds number, defined by (4) c is the sound velocity in the liquid f is the friction factor, depending on Re g is the acceleration due to gravity t is the time v is the liquid velocity in the pipeline η is the liquid viscosity ρ is the liquid density Φ is the function defined in equation (3).
PM indicates the pressure measured by the measuring system M of FIG. 16 . Hereinafter, with no limitations, M is presumed to be placed at one end of the pipeline, i.e. just before one of the interception valves.
For the numerical resolution, the pipeline is ideally divided into a wide number of elements E n , with n=1 . . . N, consisting of two halves of the same length inside which the roughness and diameter values are constant. The elements have a length of
λ = δ t c 2 ( 7 )
wherein δt is the sampling interval of the pressure measurements in the measuring point PM.
Any E n element is in the average position z n which is
Z n =nλ−λ/ 2 (8)
and has two diameters D n up and D n down and two roughness values ε n up and ε n down , associated with the upper and lower halves, respectively.
Possible diameter changes can only take place inside each element. Consequently, the parameters relating to the lower part of each element are the same as that relating to the upper part of the following element:
D n down =D up n+1 (9)
ε n down =ε up n+1 (10)
The number N of the elements, each of them having a length of λ, is given by:
N = Δ t R δ t ( 11 )
wherein Δ t R is the time between the transit and its rebound at the other end of the pipe, as illustrated in FIG. 18 .
By indicating with A n up and A n down the areas of the upper and lower sections of each element, in the elements in which the upper diameter is different from the lower diameter, the following equation is used:
V n up A n up =v n down A n down (12)
which represents the inflow and outflow balance of the element.
The initial conditions for the resolution of the system of equations are given by the pressure profile under steady conditions, calculated for each element starting from the measuring point M, by using the equations for the pressure drops containing the Fanning friction factor and an empirical equation for the calculation of the friction factor, such as, for example, the Colebrook formula (Colebrook, J. Inst. Civ. Eng. [London], 11,133-156 1938-39).
The boundary conditions for the resolution of the equation system are given by the fixed (and constant) value of the pressure at the end of the pipe where the flow rate transient is applied before the beginning of the closing operation
p ( t, 0)= po (13)
and by the evolution of the flow rate at the end of the pipe during the transient generation:
Q
(
t
,
0
)
=
{
0
t
≤
0
f
(
t
)
0
<
t
≤
Δ
t
trans
0
t
>
Δ
t
trans
(
14
)
The equations are solved using the method of characteristics, as described, for example, in D. Barba, Electronic calculation in the chemical engineering—Siderea, Rome, 1971.
In addition to the geometrical description of the well, the initial and boundary conditions and the variables linked to the discretization (number of elements), the following data must also be provided at the simulator inlet:
The time span dt of the simulation, defined by the formula dt=δt/2 and the total time t sym , during which the simulation is carried out. The flow rate evolution Q(t) made discrete according to the time span of the simulation:
{ Q ( n dt ) 0 ≤ n ≤ Δ t trans / dt 37 Q ( 0 ) = 0 Q ( Δ t trans / dt ) = 0 ( 15 )
wherein Δ t trans is the time span between the beginning of the transient (t=0) and the end of the transient.
The value c of the sound velocity in the liquid, assumed as constant along the pipe and calculated, after the first transient generation, by dividing the double of the line length by the time between the pressure peak generated and its rebound on the other end of the duct, as illustrated in FIG. 18 . The values of the transient velocity propagation in pipes containing hydrocarbons, vary within the range of 1,000-1,300 m/s. An estimation of the viscosity values, diameter and roughness for an initial tract of the pipe, from the measuring point of a length (measured along the pipe) ζ, whose value can be estimated starting from the sound velocity c and from the measurement of the time span between the maximum of the pressure transient peak and its end, as illustrated in FIG. 18 :
ζ= cΔt p /2 (16)
The characteristics of the pipeline for a distance ζ from the measuring point, as well as those of the fluid contained therein, cannot be obtained from the methods explained herein. In practice, this does not represent an important limit, as the equipment of FIG. 1 allows transients to be generated for which Δt p =0.04 s and therefore ζ varies within the range of 20-26 m for velocities c ranging from 1,000 to 1,300 m/s.
A diameter D(ζ) and roughness ε(ζ) profile of the pipe, according to the discrete sectioning of the pipe defined above. If these are not known, for example due to the presence of deposits which have altered, in a way that cannot be defined “a priori”, the inner diameter of the duct, the inner diameter profile and an average (constant) value of the roughness can be obtained through methods which will be exposed hereunder. Therefore, in correspondence with each element E n , the following are defined:
D n up e D n down (17)
ε n up and ε n down (18)
The pressure value in the measuring point at time 0, corresponding to zero flow rate:
PM(t=0). (19)
Once the inlet data have been provided, the following can obtained with the simulator:
The evolution of the velocity profile v n up (n dt)=v n down (n dt) with n=0 . . . t sym /dt. The evolution of the profile of the pressures P n (n dt) in the central point of each element E n and, in particular, the pressure evolution in the measuring point PM=P 1 .
Application of De-structuring Waves to the Fluid
Following the generation of the flow rate and pressure wave by means of the equipment of FIG. 16 , illustrated in FIG. 20 , all of the ξ points of the pipeline through which the wave passes, are also subjected to wall stress, expressed by σ(ξ, t). From the moment of the transient generation, the maximum value of the wall stress caused by the same in all points of the pipeline is given by:
σ max (ξ)=Max (σ(ξ, t) for times t subsequent to the transient generation.
In words, σ max (ξ) represents the maximum wall stress generated, in each point of the duct, by the flow rate transient generated with the help of the equipment of FIG. 16 .
The present invention indicates that the stress will produce an irreversible effect on the fluid during its structuring, on the condition that σ max (ξ)>τ(ξ,t), wherein t, in this formula, stands for the time span between the stoppage of the fluid and the wave passage and τ(ξ,t) is the yield stress of the fluid present in position ξ of the duct at time t.
The maximum value of the wall stress caused by the perturbation, can be calculated in different ways for each pipeline. An example will be provided hereunder, in which this calculation is effected with the help of the fluid dynamic simulator of transients described in the following paragraph.
In the case of the example, the flow rate transient illustrated in FIG. 17 generate the wall stress σ max (ξ) along the pipe illustrated in FIG. 19 , for three different values of the viscosity of the fluid present in the duct: 10 cP, 100 cP and 1,000 cP.
When this fluid is a waxy crude having, at time t, a yield stress of 5 Pa, then the transient thus generated is capable of generating a permanent de-structuring effect on the fluid itself. If this stress is not sufficient with respect to the fluid present in the duct, it is possible to increase the volume V of the container C, with the same filling time, so as to increase the wall stress value, until the desired de-structuring effect is obtained.
As mentioned before, with the equipment illustrated in FIG. 16 , the propagation phenomenon of the pressure waves generated in the fluid, can also be used to determine the evolution with time of the viscosity of the fluid present in the duct. For this purpose, it is possible to use the analysis method of the pressure signals registered by the system M presented hereunder.
In this way, the equipment illustrated in FIG. 16 can be applied to generate stress which reduces the structuring of the fluid, and to measure the evolution with time of its viscosity and, therefore, to control the entire process.
Measurement of the Profile of the Inner Diameters of the Duct.
The flow rate transient thus generated induces an evolution of the pressure, measured, for example, near the production point of the transient, analogous to that illustrated in FIG. 20 . The course of the pressure shown in the figure, was obtained using the simulator described in the specific paragraph and it is representative of the actual behaviour in the pipeline. In the example, the pressure in the measuring point, in a stop condition, is assumed as being equal to 80 bar.
The pressure peak generated with the equipment of FIG. 16 , by propagating along the duct, in addition to generating the local stress which represents the object of the present invention, can partially or completely rebound on possible obstacles, diameter variations of the duct or fluid non-homogeneity. In the case of a uniform fluid in a duct with a uniform real diameter, the signal rebounds on the other end of the closed line and return to the measuring point. Real diameter means the diameter actually available to the fluid, due to the pipeline and to possible deposits therein.
These rebounds are repeated until the signal is gradually exhausted, as illustrated in FIG. 21 .
It should be noted that the amplitude of the first rebound can, in general, be even larger than the first impulse generated. The amplitude of the different rebounds, i.e. their attenuation, depends on several factors, among which the viscosity of the fluid contained in the duct.
In general, any sudden change in the real inner diameter of the duct, or pipe roughness, or again in the viscosity or density of the fluid contained therein, causes the partial or complete rebounding of the wave generated, and can be detected by analysing the pressure signals recorded by the measuring equipment M of FIG. 16 .
With reference to the example duct, FIG. 22 shows the signal associated with a change in the inner diameter of the duct with an expansion equal to 0.002 m situated at 500 m from the transient generation point. Again as an example, FIG. 23 shows the signal associated with a localized restriction (length 1 m) of the inner diameter of the duct equal to 0.002 m situated at 500 m from the transient generation point. Experiences on real pipes show that both examples illustrated in the figure are realistic and that the characteristics indicated can be found in practice.
Experience shows that, even when the wave set undergoes a progressive widening, due to dispersion phenomena which induce components having a different frequency to propagate in the pipeline at different speeds, the qualitative analysis techniques of the signal remain unaltered, whereas quantitative analyses would require the use of a simulator capable of reproducing the dispersion phenomena. The simulator shown in the text is not capable of performing this function.
Duct with a Changeable Real Inner Diameter
Real diameter means the diameter actually available to the fluid, due to the pipeline itself and to possible deposits therein.
A method is described hereunder which is useful for quantifying the real inner diameter of a duct and the viscosity profile of the fluid contained therein, starting from the pressure data recorded by the equipment of FIG. 1 . The method can be applied to any pipe, regardless of its inclination, provided it contains a liquid and does not have gas pockets which almost completely or completely occupy some of its tracts. If some free gas is contained in the duct, as in the case of an oil under a pressure lower than its bubble pressure, before applying these methods, it is necessary for the pressure in all points of the duct to be increased above the bubble pressure, for example by injecting small amounts of liquid into the duct or, in the case of a well, by reducing its flow rate supply. If these maneuvers are not completely effective, it should be considered that small amounts of free gas could be interpreted as expansions of the inner diameter. Higher quantities of free gas, on the contrary, could have a negative influence on the propagation of the flow rate and pressure transients, thus limiting the efficacy of the stress and measurement techniques.
The survey methods of the inner diameter profiles and viscosity consist of several steps illustrated hereunder.
Step 1—Generation and Measurement of the Pressure Transients.
The transients are produced and recorded making use of the equipment illustrated in FIG. 16 .
The different characteristic times of the phenomenon and of the method are illustrated in FIG. 2 , which shows the trend of the pressure at the well head during a closing operation; the graph shows the different times in question.
The head pressure data must be acquired before the well closing operation (t=0) and during a time t=t max . The time t max must be higher than the time Δt R required by the flow rate and pressure wave for reaching the end of the pipe tract in question and returning to the surface. The relationship between the length L of the pipe, the velocity c of the wave propagation and the back time Δt R is:
Δt R =2 L/c
and can be used to determine any of the values, once the other two are known.
δt will indicate the time span between the PM values measured of:
PM ( t ) t= 0, δt, 2δt, . . . t max .
The PM values measured in this phase are the starting data necessary for processing the subsequent phases.
Step 2—Interpolation of the Flow Rate Transient.
In this phase, the PM data measured during the fast closing operation (first item of phase 1), are interpolated: starting from a flow rate value of zero Q(t=0)=0, the curve of Q(t) is obtained which best allows the head pressure change due to the transient to be interpolated.
The third and last phase varies in relation to the variable which is to be obtained. Immediately after the closing of the duct, it is normally useful to determine the real profile of the inner diameters of the duct. In this case we have:
Step 3—Calculation of the diameter profile along the duct.
In this step, by using the values measured in step 1 and the law of the flow rate variation obtained in step 2, a profile of the diameters of the pipe D(ξ) is obtained, such as to reproduce the evolution of the pressure measured in the time span Δt R .
In practice, starting from the element E k , where k is given by
k=ξ/λ
the value of the diameter is adjusted so as to adapt the simulated head pressure with the real pressure, with a constant increase in time:
D k+j down is modified so that
P simulated (Δt p +j dt)=P measured (Δt p +j dt) j=1, 2, . . . until all the diameters have been adapted. In this way, in a single passage, all the values of the diameters along the production pipeline starting from the experimental pressure values, are obtained.
The same logic can be subsequently used for determining the viscosity profile:
Step 3′—Calculation of the Viscosity Profile Along the Duct.
In this step, the profile of the fluid viscosity values along the pipe η(ζ) is obtained, so as to reproduce the evolution of the pressure measured in the time span Δt R , by using the values measured in step 1 and the law of the flow rate variation obtained in step 2.
In practice, starting from the element E k , where k is given by:
k=ζ/λ
the diameter value is adjusted so as to adapt the simulated head pressure with the real pressure, at an ever-increasing time:
η(k+j) is modified so that
P simulated (Δt p +jdt)=P measured (Δt p +jdt) for j=1, 2, . . . until all the diameters have been adapted. In this way, in a single passage, all values of viscosity along the production pipeline starting from the experimental values of pressure, are obtained.
It is easy to adapt the same procedure to the determination of other variables associated with the duct or to the fluid, which can be of interest for a certain application.
Pipeline Having a Constant Inner Real Diameter
A simplified procedure is described hereunder which can be used for determining the viscosity of the fluid present in the duct when the duct has a uniform real inner diameter.
In this case, the stress produced by means of the equipment of FIG. 16 has the behaviour illustrated in FIG. 21 . The pressure peaks, starting from the first rebound, progressively decrease in intensity until they can no longer be recorded by means of the measuring apparatus. The drop in the peak amplitude depends, among other things, on the viscosity of the fluid present in the duct.
FIG. 25 shows the logarithm, for numerous liquid viscosity values, of the amplitude of peaks represented in FIG. 21 , normalised with respect to the amplitude of the first rebound.
The amplitude of each peak is calculated, for the construction of the figure, as the difference, in absolute value, between the base, evaluated before the peak itself, and its more extreme point. The curves represent different viscosities and show that, from the first rebound onwards, the log 10 of the peak drop in the subsequent rebounds, follows an approximately linear law. The slope of the straight line which interpolates, once the fluid viscosity in the duct has been established, the log 10 of the amplitude of the pressure peaks in relation to the rebound numbers on the pipe ends (from the first onwards), will be called hereunder “fading coefficient” and expressed as α. FIG. 25 therefore suggests that the fading coefficient is a function of the viscosity, and this is indicated in FIG. 26 .
From a more careful theoretical investigation, it can be observed that the fading coefficient is proportional to the pressure drops which will take place in the duct, under stationary conditions, if the fluid flow rate is constant and equal to the maximum of the flow rate peak generated by the equipment of FIG. 16 .
In the example illustrated herein, the fading coefficient of the peaks normalised with respect to the first rebound, is proportional to the pressure drops at the stationary flow rate of 15 m 3 /h (maximum peak value of FIG. 17 ). In the example considered, when the viscosity is higher than 0.9 mPas, the flow is laminar, whereas for lower viscosities, the flow is turbulent. The transition from lamellar to turbulent flow is the origin of the “step” present in FIG. 26 .
Experience shows that, in the presence of dispersion phenomena which lead to the progressive widening of the pressure peaks in the subsequent rebounds, the amplitude of each peak must be substituted with the area of its first half. In the formula, with reference to FIG. 27 , it is necessary to substitute the area A j of each peak at its height H j .
With reference to the object of the present invention, if the viscosity of the fluid present in the pipeline, due to a structuring process, progressively increases along the pipe, the generation of flow rate transients by means of the apparatus of FIG. 16 and the measurement of the corresponding coefficient of the pressure peak drop, will provide a rapid quantitative indication of the viscosity evolution of the fluid and consequently a simple control method of the entire process. If the fluid viscosity is considerably non-homogeneous along the duct, for example due to strong temperature variations, or the inner diameter is not constant, then the viscosity estimation should be effected by means of the other analysis methods specified above. | A process for reducing the restart pressure of streams selected from waxy crude oils, water-in-crude emulsions and dispersions of hydrocarbon hydrates, at least partially structured. A mechanic disturbance is applied, in flow-stop conditions, on the streams, having: temperatures lower than the WAT (Wax Appearance Temperature) for the waxy crude oils and water-in-crude emulsions; temperatures lower than the forming temperatures of the hydrates and pressures higher than the forming pressure of the hydrates, for the dispersions of hydrocarbon hydrates. | 8 |
This is a divisional of application Ser. No. 09/098,460 (Confirmation No.: Not Assigned) filed Jun. 17, 1998, now abandoned the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for molding a magnetic tape cassette such as a video tape cassette and the like, and more particularly, for molding guide walls of a brake member, in the magnetic tape cassette, which prevents a magnetic tape from loosening. In addition, the present invention relates to an apparatus in which the above-mentioned molding method is operable.
2. Description of the Related Art
Conventionally, there are known various types of magnetic tape cassettes that can be used in a video deck. As an example of the magnetic tape cassettes, there are relatively small-sized magnetic tape cassettes used in a digital video cassette (DVC).
FIG. 4 is an exploded view of a general magnetic tape cassette 30 that is structured in the following manner. A pair of reels 32 a and 32 b is rotatably disposed on a lower half-case 31 (hereinafter referred to as “lower half”). Around the two reels 32 a and 32 b , a magnetic tape T (not shown in FIG. 4) is wound. The magnetic tape T is guided by two tape guides 33 a and 33 b located at the right and left sides of the front end of the cassette 30 . The two tape guides 33 a and 33 b allow the magnetic tape to pass through an opening 34 formed on the front end side of the lower half 31 . As shown in FIG. 4, teeth 35 a and 35 b are formed along the entire peripheral edges of the lower flanges 32 L a and 32 L b of the two reels 32 a and 32 b.
As also shown in FIG. 4, a brake member 38 is provided between the two reels 32 a and 32 b in a space 36 located on the rear side of the lower half 31 . The brake member 38 prevents the magnetic tape T from loosening when the magnetic tape cassette 30 is not loaded in a video deck (not shown), but is instead located in a storage place or is being carried.
A pair of securing pawls 37 a and 37 b is provided near the front end of the brake member 38 . The securing pawls 37 a and 37 b form a lock member to lock the rotation of the reels 32 a and 32 b together with the brake member 38 . In addition, a compression spring (brake spring) 39 is provided at the rear end of the brake member 38 in the lower half-case 31 . The compression spring is used to urge the brake member 38 towards the front side of the lower half-case 31 .
As shown in FIG. 4, an upper half-case 40 (hereinafter referred to as “upper half”) cooperates with the lower half 31 to form the magnetic tape cassette 30 . The upper half 40 includes a lid for covering the opening in the front end portion of the lower half 31 . The lid is composed of an outer lid 41 , an upper lid 42 , and an inner lid 43 . The opening can be freely opened and closed using these lids.
The outer lid 41 of the upper half 40 includes a side plate 44 having a projecting lock pin 45 . Correspondingly, a lid lock 47 , which is rotatably mounted on one side plate 46 of the lower half 31 , locks the outer lid 41 of the upper half 40 by engaging with the lock pin 45 . A plate spring 48 urges the lid lock 47 toward the locking side thereof.
As shown in FIG. 4, a rotary shaft 44 b projects from an inner side of the side plate 44 of the outer lid 41 . A lid spring 49 , which is mounted on the rotary shaft 44 b , is used to open and close the outer lid 41 . In FIG. 4, reference numerals of components other than main components of the magnetic tape cassette 30 are omitted, since descriptions thereof are not believed to be essential for an understanding of the general cassette 30 .
FIG. 5 shows a conventional lock device for locking the rotation of the reels 32 a and 32 b of the general magnetic tape cassette 30 described above with reference to FIG. 4 . In the conventional lock device, the brake member 38 is urged in the forward direction, which is the direction in which the compression spring 39 (brake spring) is compressed. The compression spring 39 is supported along the floor surface 31 a of the lower half 31 shown in FIG. 4, and has one end engaged with the floor surface 31 a and the other end engaged with the rear end of the brake member 38 . The compression spring 39 urges the brake member 38 in the forward direction when the cassette 30 is not loaded in a video deck. An insertion hole 51 is formed substantially in the central portion of the bottom surface 38 a of the brake member 38 . A lock release pin of the video deck (not shown) is inserted into the insertion hole 51 of the brake member 38 when the magnetic tape cassette 30 is loaded in a video deck, thereby allowing the reels 32 a and 32 b to rotate.
A pair of guide walls 52 a and 52 b is provided on the left and right positions of the insertion hole 51 , and slidingly guides movement of the brake member 38 . Facing brake member removal-prevention projections 53 a and 53 b are provided on the upper ends of the two guide walls 52 a and 52 b so as to prevent the brake member 38 from being removed from the cassette 30 .
As described above, the two guide walls 52 a and 52 b are conventionally provided on the left and right sides of the brake member 38 . The two guide walls 52 a and 52 b are located to the left and right of the insertion hole 51 because it is necessary to facilitate the removal of molds employed in a resin injection-molding method. FIG. 6 is a cross-sectional view of a metal mold 120 used for explaining the conventional molding method. The metal mold 120 is used to mold the lower half 31 of the cassette 30 , and is composed of an upper mold UM and a lower mold LM. The lower mold LM has a component mold CM for molding inner surfaces of the guide walls 52 a and 52 b . As shown in FIGS. 5 and 6, if the two guide walls 52 a and 52 b are erected on the lower half 31 and are disposed adjacent to the insertion hole 51 , the component mold CM may be easily removed in the direction L 6 after completion of the injection-molding.
However, the location of the pair of guide walls 52 a and 52 b has drawbacks in that the brake member removal-prevention projections 53 a and 53 b , which are provided on the upper ends of the guide walls 52 a and 52 b , do not sufficiently hold the brake member 38 . In other words, the pair of guide walls 52 a and 52 b holds only the substantially central portion of the brake member 38 . As a result, the brake member 38 can fly out or slip off from the two guide walls 52 a and 52 b due to the urging force of the compression spring 39 in the assembled magnetic tape cassette.
In view of the above-described drawback, it is preferable to support the brake member 38 using two or more pairs of guide walls respectively with brake member removal-prevention projections that are the similar to those identified with reference numerals 53 a and 53 b . For example, as shown in FIG. 2, if two pairs of guide walls have brake member removal-prevention projections, the brake member 38 can be supported in both the front and rear end portions. However, such an arrangement requires that the two pairs of guide walls should be located far from the is insertion hole 51 .
Moreover, the conventional apparatus and methods cannot be used to injection-mold such a two-pair structure because the component mold CM exists between the two guide walls 52 a and 52 b . As described above, the component mold CM is conventionally removed from the insertion hole 51 in the direction L 6 , as shown in FIG. 6 . Therefore, the component mold CM cannot be removed because the brake member removal-prevention projections 53 a and 53 b mutually overhang and prevent the component mold CM from being removed in the direction L 6 .
SUMMARY OF THE INVENTION
It is an object of the present invention to overcome the above-mentioned drawbacks found in the conventional magnetic tape cassette molding method and apparatus. That is, it is an object of the present invention to provide a magnetic tape cassette molding method that more easily molds guide walls for holding a brake member.
A further object of the present invention is to provide an apparatus for performing the above method.
The above object can be attained by a mold apparatus for injection-molding a magnetic tape cassette having a pair of mutually opposing guide walls respectively erected on an upper surface of a half-case of the magnetic tape cassette. The opposing guide walls slidably support a brake member that locks rotations of a pair of tape winding reels disposed within the magnetic tape cassette. Each of the guide walls has a projection for preventing the brake member from being dislodged from between the guide walls. The mold apparatus comprises a first mold, a second mold and a third mold. The first mold, which is removable in a direction that is opposite the erected direction of the guide walls, forms a lower surface of the half-case. The second mold, which is removable in the erected direction of the guide walls, forms outer side surfaces of the guide walls. The third mold, which is removable in the erected direction of the guide walls, forms inner side surfaces of the guide walls that are brought into contact with the brake member. The third mold includes grooved portions respectively forming the projections of the guide walls. When assembled, the first, second and third molds form a molding cavity defined by the pair of mutually opposing guide walls.
In the above-mentioned construction, it is preferable that the projections of the apparatus are respectively positioned at leading ends of the guide walls.
Each of the projections of the apparatus, whether or not the projections of the apparatus are respectively positioned at leading ends of the guide walls, may have a surface that curved in cross section.
At least two pairs of the guide walls of the apparatus, whether or not the projections of the apparatus are respectively positioned at leading ends of the guide walls, are arranged at a predetermined interval in a sliding direction of the brake member.
Further, in accordance with the present invention, there is provided a method for injection-molding a magnetic tape cassette using a molding apparatus such as the one described immediately above. The method comprises the steps of forming a molding cavity using first, second and third molds such as the ones described above, molding molten resin into the molding cavity so as to form the mutually opposing guide walls, and then removing the second and third molds. The second mold is removed first, in the erected direction of the guide walls, so as to release the second mold from the molded guide walls. The third mold is then removed in the erected direction of the guide walls, while a distance between the projections formed on the guide walls is enlarged due to elastic deformation of the guide walls resulting from contact between the third mold and the projections formed on the guide walls.
In addition, the method may further comprise the step of guiding the removal of the third mold using the projections, wherein each of the projections has a surface that is curved in cross section.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of the magnetic tape cassette molded by the magnetic tape cassette molding method according to the present invention;
FIG. 2 is an enlarged perspective view of the main portions of the magnetic tape cassette shown in FIG. 1;
FIGS. 3 (A) to (C) illustrate the mold apparatus and the magnetic tape cassette molding method according to the present invention, showing the order of the molding steps thereof;
FIG. 4 is an exploded perspective view of a conventional magnetic tape cassette; and
FIG. 5 is an enlarged perspective view of the main portions of the conventional magnetic tape cassette of FIG. 4; and
FIG. 6 is a sectional view of a metal mold used for explaining the conventional magnetic tape cassette molding method.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 to 3 (A-C) show an embodiment of an apparatus for molding a magnetic tape cassette according to the present invention. Referring to FIG. 1, a magnetic tape cassette 1 includes an upper half (not shown in FIG. 1) and a lower half 2 . A pair of freely rotatable reels 3 a and 3 b , having a magnetic tape T wound therearound, may be provided in the lower half 2 . Teeth 4 a and 4 b extend along the entire peripheral edge of each of the lower flanges of the two reels 3 a and 3 b , respectively. The teeth 4 a and 4 b engage with securing pawls 8 a and 8 b (to be discussed further below).
A lock device 6 is provided in a substantially triangle-shaped space 5 , which is located between and defined by the two reels 3 a and 3 b . The lock device 6 locks the rotation of the two reels 3 a and 3 b , and prevents the magnetic tape T from loosening when the magnetic tape cassette 1 is not loaded in a video deck (not shown). Elements or mechanisms, other than the lock device 6 of the present invention, are the same as those of the general magnetic tape cassette discussed above with reference to FIG. 4, and thus descriptions thereof are omitted here.
The lock device 6 , as shown in FIG. 2, comprises a brake member 7 , two securing pawls 8 a and 8 b and a compression spring 9 . The brake member 7 is slidably interposed between the two reels 3 a and 3 b to lock the reels 3 a and 3 b , while the two securing pawls 8 a and 8 b are respectively provided on the two sides of the leading end portion of the brake member 7 . The two securing pawls 8 a and 8 b engage with the teeth 4 a and 4 b that are formed on the reels 3 a and 3 b , and lock the reels 3 a and 3 b in place. The compression spring 9 urges the brake member 7 toward the reels 3 a and 3 b when the cassette 1 is not loaded in the video deck.
As mentioned above, movements of the brake member 7 result in the lock and release of the reels 3 a and 3 b . This is accomplished by forming a releasing pin insertion hole 10 on the floor surface 31 a of the lower half 2 (shown in FIG. 4 ), and a corresponding releasing pin insertion hole 10 a in the lower surface 7 a of the brake member 7 . When the magnetic tape cassette is loaded into the video deck, a releasing pin of the video deck (not shown) is inserted into the two releasing pin insertion holes 10 and 10 a . This insertion of the releasing pin causes the brake member 7 to return to its original position, and unlock the two reels 3 a and 3 b.
Two pairs of guide walls 11 a , 11 b and 12 a , 12 b are provided on the left and right sides of the brake member 7 , far from the releasing pin insertion hole 10 . In other words, the two pairs of guide walls 11 a , 11 b and 12 a , 12 b are located at the front and rear end portions of the sliding area of the brake member 7 , and are used for guiding the sliding movements of the brake member 7 . Brake member removal-prevention projections 111 a , 111 b and 112 a , 112 b are provided at the respective leading ends of the two pairs of guide walls 111 a , 111 b and 12 a , 12 b . The brake member removal projections 111 a , 111 b and 112 a , 112 b project and overhang inwardly to support the brake member 7 at the top surface 10 b of the brake member 7 , so as to prevent the sliding brake member 7 from dislodging from the guide walls 11 a , 11 b and 12 a , 12 b.
Therefore, the two pairs of guide walls 11 a , 11 b and 12 a , 12 b can smoothly guide the sliding brake member 7 . In addition, the brake member removal-prevention projections 111 a , 111 b and 112 a , 112 b , which are additionally provided on the two pairs of guide walls 11 a , 11 b and 12 a , 12 b , can prevent the brake member 7 from dislodging from the two pairs of guide walls 11 a , 11 b and 12 a , 12 b.
Each of the surfaces of the respective upper end portions of the brake member removal-prevention projections 111 a , 111 b and 112 a , 112 b is preferably curved in cross section. The curved surfaces facilitate the insertion, during assembly, of the brake member 7 from the uppermost portion of the guide walls 11 a , 11 b and 12 a , 12 b . In order to insert the lock device 6 between the guide walls 11 a , 11 b and. 12 a , 12 b , pressure is applied to the brake member 7 in the downward direction. The pressure can cause the guide walls 11 a , 11 b and 12 a , 12 b to be elastically flexed in the transverse direction, thereby widening the space between the guide walls 11 a , 11 b and 12 a , 12 b and allowing the brake member 7 to pass. For this reason, it is preferable that each upper surface of the brake member removal-prevention projections 111 a , 111 b and 112 a , 112 b is curved in cross section.
Further, in FIG. 1, when the magnetic tape cassette 1 is not loaded in the video deck, the compressing force of the spring 9 urges the brake member 7 toward the reels 3 a and 3 b . This compression force thereby forces the securing pawls 8 a and 8 b , which are provided on the leading end portion of the brake member 7 , into engagement with the teeth 4 a and 4 b formed on the peripheral edges of the lower flanges of the rotating reels 3 a and 3 b . Under such a condition, the reels 3 a and 3 b are locked, and the magnetic tape can be prevented from slackening.
On the other hand, when the magnetic tape cassette 1 is loaded into the video deck, the locking of the reels 3 a and 3 b can be released by a locking release pin (not shown) provided in the video deck. As shown in FIG. 1, a stopper 13 , located in the substantially triangle-shaped space 5 at a position near the center of the lower half 2 , is provided to restrict the moving range of the brake member 7 . Additionally, ribs 14 are placed to the left and right of the space 5 near the outer periphery of the lower half 2 , so as to reinforce the triangle-shaped space 5 of the magnetic tape cassette.
FIGS. 3 (A) to (C) illustrate the method for molding the lower half 2 of the magnetic tape cassette, according to the present invention. A metal mold 20 used for performing this molding method is composed of an upper mold 21 and a lower mold 22 . The lower mold 22 can be composed of a single mold. On the other hand, the upper mold 21 is composed of both a guide wall inner mold 23 and a guide wall outer mold 24 . The guide wall inner mold 23 and the guide wall outer mold 24 define a cavity between the guide walls 11 a and 11 b , 12 a and 12 b.
The guide wall inner mold 23 forms the guide walls 11 a and 11 b , 12 a and 12 b . The guide wall inner mold 23 has flat portions 25 a and 25 b that are preferably erected in the vertical direction on the lower half 2 . In addition, the guide wall inner mold 23 has curved-groove portions 26 a and 26 b that are grooved more inwardly than the flat portions 25 a and 25 b , and are used for forming the brake member removal-prevention projections 111 a , 111 b and 112 a , 112 b . The flat portions 25 a and 25 b and the curved-groove portions 26 a and 26 b are arranged in the substantially triangle-shaped space 5 shown in FIG. 2 . The arrangement preferably corresponds to the front and back portions of the space 5 of the magnetic tape cassette 1 to be molded.
As shown in FIGS. 3 (A) to (C), recessed grooves 27 , which are used to shape ribs 14 , are formed on the bottom surface of the guide wall inner mold 23 . In practical use, the one pair of guide walls 11 a and 11 b need not be arranged so as to form a row with the other pair of guide walls 12 a and 12 b.
As shown in FIGS. 3 (A) to (C), the guide wall outer mold 24 of the upper mold 21 is structured such that the inside portions thereof are formed as flat and vertical surfaces. Grooves 27 located on the bottom surface of the guide wall outer mold 24 are used to mold the ribs 14 . On the other hand, the lower mold 22 is structured so as to have a flat upper surface.
As shown in FIG. 3 (A), in order to injection-mold the lower half 2 of the magnetic tape cassette 1 , the metal mold 20 is first assembled. That is, the lower mold 22 and the upper mold 21 , which is composed of the guide wall inner mold 23 and the guide wall outer mold 24 , are assembled.
Resin is then injected into the cavity defined by the metal mold 20 , and the lower half 2 (shown in FIGS. 3 (A) to (C)) is molded.
After the lower half 2 is molded, the lower mold 22 is separated from the lower half 2 in the direction L 4 , as shown in FIG. 3 (A). The guide wall outer mold 24 is then separated from the newly molded lower half 2 in the direction U 4 , as shown in FIG. 3 (B). Because there are no recessed portions in the guide wall outer mold 24 , the guide wall outer mold 24 can be removed with ease. Alternatively, the lower mold 22 may be removed after the guide wall outer mold 24 and the guide wall inner mold 23 of the upper mold 21 are removed from the molded lower half 2 .
Then, as shown in FIG. 3 (C), the guide wall inner mold 23 of the upper mold 21 is removed from the lower half 2 in the direction U 4 . The guide wall outer mold 24 must be removed before the guide wall inner mold 23 so that the guide wall inner mold 23 can be removed smoothly. That is, after the guide wall outer mold 24 is removed, the molded guide walls 11 a , 11 b , 12 a and 12 b , as shown in FIG. 3 (C), may be elastically deformed in the widening direction Wa and Wb. This removal operation is termed “forcible removal”. Additionally, because each lower end of the brake member removal-prevention projections 11 a , 111 b , 112 a and 112 b has a surface that is curved in cross section, the guide walls 11 a , 11 b , 12 a and 12 b can be elastically deformed more smoothly while removing the guide wall inner mold 23 .
With the conventional molding method described in the background section of this application, the structure of the apparatus determines the method of removal. Therefore, the guide walls having the brake member removal-prevention projections are unable to be molded at positions far from the releasing pin insertion hole 10 .
On the other hand, according to the present invention, the lower half 2 of the magnetic tape cassette 1 can be injection-molded even though the magnetic tape cassette 1 has guide walls 11 a , 11 b , 12 a and 12 b including brake member removal-prevention projections 111 a , 111 b , 112 a and 112 b . That is, the guide wall inner mold 23 can be removed easily even when the guide walls having the brake member removal-prevention projections are located at positions far from the releasing pin insertion hole 10 . This removal is easily accomplished because the upper mold 21 is divided into the guide wall inner mold 23 and the guide wall outer mold 24 , and the guide wall outer mold 24 is removed before the guide wall inner mold 23 .
Since the brake member removal-prevention projections 111 a , 111 b , 112 a and 112 b of the guide walls 11 a , 11 b , 12 a and 12 b support the brake member 7 from above, the brake member 7 can be slid more smoothly than the conventional device. Furthermore, the additional support provided by the four projections virtually eliminates the possibility that the brake member 7 will become dislodged from the guide walls 11 a and 11 b , 12 a and 12 b.
In the above-mentioned embodiment, the two pairs of guide walls 11 a , 11 b and 12 a , 12 b may be respectively provided in the front and rear portions of the brake member 7 . However, the invention is not limited to this structure. The invention may, for example, instead include a pair of long guide walls extending from the front to the rear portions of the brake member 7 . Such a structure also permits the components molds to be removed with ease, and can prevent the brake member 7 from being dislodged from the guide walls 11 a , 11 b , 12 a , 12 b.
As has been described hereinabove, according to the present invention, the upper mold is divided into a guide wall inner mold and a guide wall outer mold. First, the guide wall outer mold is removed in the upward and vertical direction. Next, the guide wall inner mold is removed in the same direction. Owing to this, it is possible to produce, by injection-molding resin using the metal mold 10 , a magnetic tape cassette that has guide walls located in a position far from the releasing pin insertion hole.
Additionally, it is surely possible to prevent the brake member from becoming dislodged from the guide walls, even though the guide walls are located in positions far from the releasing pin insertion hole 10 .
The present application is based on Japanese Patent Application No. Hei. 9-161441, which is incorporated herein by reference.
While only certain embodiments of the invention have been specifically described herein, it will be apparent that numerous modifications may be made thereto without departing from the spirit and scope of the invention. | A mold apparatus for forming a pair of mutually opposing guide walls respectively disposed and erected on an upper surface of a half-case of a magnetic tape cassette. The mold apparatus is divided into a third mold and a second mold, and the guide walls to be molded form the boundary between the third and second molds. After injecting resin into the mold apparatus in order to mold the guide walls, the second mold of the mold apparatus is firstly removed in the guide wall erected direction. Then, the third mold of the mold is removed in the same direction, while a distance between the formed guide walls is enlarged by elastic deformation resulting from contact between the guide walls and the third mold. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Claims priority to provisional application 61/334,362 filed May 13, 2010.
STATEMENTS REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
REFERENCE TO A MICROFICHE APPENDIX
Not applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to radiation detection. More particularly, the invention relates to a method and apparatus for passive detection of neutron emitting materials with applications in homeland security and nuclear safeguards.
2. Description of the Related Art
US government plans to equip major seaports with large area neutron detectors, in an effort to intercept the smuggling of nuclear materials, have precipitated a critical shortage of 3 He gas. It is estimated that the annual demand of 3 He for US security applications alone is 22 kiloliters, more than the worldwide supply. This is strongly limiting the prospects of neutron science, safeguards, and other applications that rely heavily on 3 He-based detectors. Clearly, alternate neutron detection technologies that can support large sensitive areas, and have low gamma sensitivity and low cost must be developed.
The applicant has previously developed and patented a technology based on close-packed arrays of long aluminum or copper tubes (straws), 4 mm in diameter, coated on the inside with a thin layer of 10 B-enriched boron carbide ( 10 B 4 C). In addition to the high abundance of boron on Earth and low cost of 10 B enrichment, the boron-coated straw (BCS) detector offers distinct advantages over conventional 3 He-based detectors, including faster signals, short recovery time (ion drift), low weight, safety for portable use (no pressurization), and low production cost.
The background to the present invention and related art is best understood by reference to Applicant's own prior work, including in particularly, U.S. Pat. No. 7,002,159 B2 (the '159) entitled “Boron Coated Straw Neutron Detector” which issued Feb. 21, 2006. The '159 is hereby incorporated by reference in its entirety, for all purposes, including, but not limited to, supplying background and enabling those skilled in the art to understand, make and use in Applicant's present invention.
The background to the present invention and related art is best understood by reference to Applicant's own work. Applicant's issued patents and pending applications that may be relevant, including; (1) U.S. Pat. No. 5,573,747 entitled, “Method for Preparing a Physiological Isotonic Pet Radiopharmaceutical of 62 CU; (2) U.S. Pat. No. 6,078,039 entitled, “Segmental Tube Array High Pressure Gas Proportional Detector for Nuclear Medicine Imaging”; (3) U.S. Pat. No. 6,264,597 entitled, “Intravascular Radiotherapy Employing a Safe Liquid Suspended Short-Lived Source”; (4) U.S. Pat. No. 6,483,114 D1 entitled, “Positron Camera”; (5) U.S. Pat. No. 6,486,468 entitled, “High Resolution, High Pressure Xenon Gamma Rays Spectroscopy Using Primary and Stimulated Light Emissions”; (6) U.S. Pat. No. 7,002,159 B2 (the '159) entitled “Boron Coated Straw Neutron Detector”; (7) U.S. Pat. No. 7,078,704 entitled, “Cylindrical Ionization Detector with a Resistive Cathode and External Readout”; (8) U.S. patent application Ser. No. 10/571,202, entitled, “Miniaturized 62 Zn/ 62 CU Generator for High Concentration and Clinical Deliveries of 62 CU Kit Formulation for the Facile Preparation of Radiolabeled Cu-bis(thiosemicarbazone) Compound”; (9) U.S. patent application Ser. No. 12/483,771 entitled “Long Range Neutron-Gamma Point Source Detection and Imaging Using Rotating Detector”; (10) U.S. Patent Application No. 61/183,106 entitled “Optimized Detection of Fission Neutrons Using Boron Coated Straw Detectors Distributed in Moderator Material”; (11) U.S. Patent Application No. 61/333,990 entitled “Neutron Detectors for Active Interrogation”; and (12) U.S. Patent Application No. 61/334,015 entitled “Nanogenerator.” Each of these listed patents are hereby incorporated by reference in their entirety for all purposes, including, but not limited to, supplying background and enabling those skilled in the art to understand, make and use in Applicant's present invention.
BRIEF SUMMARY OF THE INVENTION
The present invention is a method and apparatus for operating boron-coated straw detectors in sealed mode, without the need for a continuous flow of gas. Boron-coated straw detectors are described in Applicant's prior U.S. Pat. No. 7,002,159 B2 entitled “Boron Coated Straw Neutron Detector” which issued Feb. 21, 2006. The present invention includes an apparatus for detecting radiation comprising at least one boron-coated straw, a thin wall tube having a diameter sized no larger than necessary to accommodate said boron-coated straw(s); and a gas mixture sealed within said thin wall tube. Another embodiment of the present invention includes an apparatus for detecting radiation comprising multiple boron-coated straws, a thin wall tube having a diameter sized no larger than necessary to accommodate said multiple boron-coated straws; and a gas mixture sealed within said thin wall tube wherein said straws are arranged in close-packed, hexagonal configurations with the following number of tubes
N = 1 + ∑ k = 0 B - 1 6 k
wherein N=the number of boron coated straws in a detector; B=the number of layers of straws in a detector, i.e. single straw is one layer, and k=positive integers.
The gas contained within the straw detectors is a specified gas mixture, of high purity and specified pressure, and it is critical to the successful operation of the straw detectors. Straw detectors can operate either with a continuous flow of the specified gas mixture, or in sealed mode as presented here. When operated in sealed mode, proper sealing of the straw detectors is crucial for stable operation. Embodiments of the present invention include those where the gas mixture is composed of any noble gas combined with a quench gas, including CO2, CH4, CF4, C2H6, N2, H2, H2O, for absorbing photon emissions and increasing the drift velocity of electrons. Additional embodiments of the present invention include gas mixtures comprising: (1) Ar/CO2 with CO2 content in the range 1% to 20%; (2) Ar/CH4 with CH4 content in the range 1% to 20%; (3) Xe/CO2 with CO2 content in the range 1% to 20%; (4) Xe/CH4 with CH4 content in the range 1% to 20%; (5) He/CH4 with CH4 content in the range 1% to 20%; and (6) He/CO2 with CO2 content in the range 1% to 20%. An embodiment of the present invention includes having the gas mixture is maintained at an absolute pressure less than 2 atm.
Sealed-mode operation is necessary when using the boron-coated straw detectors in the field, where access to a continuous flow of the required gas mixture is not practical.
Also, sealed-mode operation is necessary when the straw detectors are used as portable instruments that must be moved from one location to the next swiftly or that must be operated while in motion.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a drawing of the present invention.
FIG. 2 shows the variation of gas gain over time, measured in prototype detectors that were sealed according to the present invention.
FIG. 3 shows the variation of gas gain over temperature, measured in prototype detectors that were sealed according to the present invention.
FIG. 4 a through FIG. 4 h shows design examples of boron-coated straw detectors grouped together to form bundles that are sealed inside a single external tube.
FIG. 5 is the predicted thermal neutron sensitivity (per unit length) of boron-coated straw bundles as a function of the number of straws making the bundle.
FIG. 6 shows the variation of gas gain over temperature, measured in a 7-straw bundle that was sealed according to the present invention.
FIG. 7 illustrates the readout circuit for seven 7-straw bundles (49 straws).
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1 , the apparatus comprises combining a thin walled aluminum or stainless steel (or similar material) tube 2 , and a fitting 3 , at either end of the tube. Fitting 3 can be composed of aluminum or other material that is easy to machine and bonds well with the other materials attached to it. The boron coated straw 1 fits entirely within the tube and is secured in place with the two end fittings. Embodiments include end fitting configured to receive and position the boron-coated straw(s) centrally within the thin wall tube and to receive and position an anode wire. The end fittings incorporate a central hole through which a ceramic feed-through tube 4 is positioned. A crimping tube 5 is positioned inside the ceramic (or other electrical insulator) tube 4 . Embodiments of crimping tube 5 are composed of copper. Crimping tubes can have an inner diameter large enough to accommodate a thin metallic wire up to 50 μm in diameter and are capable of crimping around the wire to securely retain high tension in the wire. A thin metallic wire 6 passes through the tube 5 . The wire 6 is tensioned, then crimped in place. A gold-plated pin 8 connects to the crimp tube 5 . The wire forms the anode electrode that connects, through the crimp tube 5 and pin 8 , to a high voltage supply, and to a preamplifier through a coupling capacitor. A plastic collar 7 is used to provide additional electrical insulation between the anode and fitting 3 . For embodiment including multiple boron coated straws in a single bundle, end fittings are provided with accurately positioned insulating feed-throughs capable of receiving and positioning all associated wires. Embodiments may include fitting having multiple holes through which feed-through insulating tubes are fitted. Tube 9 serves as a gas port, used to purge the volume inside tube 2 , and to fill the volume inside tube 2 with a specified gas mixture. A grounding collar 10 connects the tube 2 (cathode) to an electrical ground. The ceramic tube 4 , the crimping tube 5 , the plastic collar 7 , the gas port tube 9 and the end fittings 3 are fixed with epoxy.
Several boron-coated straw detectors were sealed using the present invention. Initially, the gas port 9 of the sealed detector was connected to a supply of a gas mixture of argon/CO2. The detector was then purged with a continuous flow of this gas mixture, while heated to 60° C. for a period of 18-24 hours. Using valves, the gas flow was stopped, then the detector was allowed to cool to room temperature. The detector was then connected to a vacuum pump, and evacuated to a pressure of 0.7 atm. The gas port 9 was then crimp sealed. In an embodiment of the present invention the gas port 9 fits inside the off-center hole of the fitting 3 and can be connected to an external vacuum and gas filling system. Embodiments of the present invention include those wherein the gas port 9 is composed of a ductile metal such as copper, stainless steel, nickel, or aluminum and capable of being sealed using pinch off technique.
In order to gage the seal quality and the resulting gas purity, the amplitude of signals corresponding to a single radiation energy were tracked in the sealed detectors over a period of time. Gas purity is essential to maintaining stable operation and an adequate signal-to-noise ratio. Gas contamination over long periods of time (due to materials outgassing, for instance) may alter the amplitude of signals, which in turn will affect the performance of the detector.
A pulse height spectrum was collected using a 241 Am gamma ray source. Photons emitted by this isotope, primarily with an energy of 60 keV, interact with the copper walls of the straw detector. At this energy, most interactions in copper are of the photoelectric kind, resulting in the absorption of the incident photon, and prompt emission of a characteristic 8 keV X-ray photon. This 8 keV X-ray photon may subsequently escape into the gas volume, and interact with argon atoms, depositing all of its energy. As a result, an 8 keV energy peak appears in the pulse-height spectrum.
The location of the characteristic X-ray peak in the gamma energy spectrum was used to track gas purity as shown in FIG. 2 .
Temperature cycling tests were also carried out to evaluate the ability of the sealed straw detector to maintain stable operation at extreme environments. FIG. 3 shows the measured variation in the neutron counts recorded in a sealed straw detector during operation inside a chamber, where the temperature was varied from +60 C to −40 C.
EXAMPLES
The proposed invention is illustrated in FIGS. 4 a to 4 h . Each figure shows a standalone detector. The detector is a close-packed bundle of straws, where each straw detector is 4 mm in diameter and of length equal to the bundle length. Embodiments of the present invention include those wherein the thin wall tube and the straw(s) are approximately equal in length. The length may vary from a few centimeters to several meters. In the embodiments of FIGS. 4 a to 4 h the straws are arranged in close-packed, hexagonal configurations with the following number of tubes
N = 1 + ∑ k = 0 B - 1 6 k
wherein N=the number of boron coated straws in a detector; B=the number of layers of straws in a detector, i.e. single straw is one layer, and k=positive integers. The bundle is housed inside a sealed aluminum or stainless steel tube fitted with a fitting of appropriate design. Embodiments of the invention include those where the thin wall tube is composed of other materials which minimizes scattering of low energy neutrons and/or low Z material to minimize the sensitivity for gamma ray interactions Depending on the number of straws bundled, the dimensions and neutron sensitivity of the tube will vary, as shown in Table 1.
The anode electrodes of all BCS detectors within the bundle are connected together and read out with a single amplifier, using common electronics typically used to read out 3 He tubes. Although the overall capacitance presented to the amplifier will be higher than that presented by a single tube of large diameter, the signals generated in the straw detectors are several times larger than those generated in 3 He tubes, and thus, the signal-to-noise ratio is not affected by the larger capacitance.
The detection efficiencies of the straw bundles were estimated in Monte Carlo simulations implemented in MCNP5 and are listed in Table 1. A parallel beam of monoenergetic neutrons was directed normally over the entire side of the bundle. The computed sensitivity (per unit length) is also plotted in FIG. 5 as a function of the number of straws. In all cases, a 10 B 4 C coating thickness of 1 μm was assumed.
The thermal neutron sensitivity of a 3 He tube, with a 5.08 cm diameter (2 inches), pressurized to 2.5 atm, is ˜3.4 cps/nv/cm, equivalent to that obtained with the 187-straw bundle, whose diameter is only slightly larger at 6.36 cm. The sensitivity of the BCS bundle can be further improved by optimizing the thickness of the 10 B 4 C coating.
The gain stability of the 7-straw bundle was also measured over the course of 255 days, as shown in FIG. 6 . The gain variation was less than ±4%.
Readout. When several straw detectors are grouped together in a bundle, reading them out separately would require a number of pre-amplifiers equal to the number of straws. Significant savings can be achieved with a readout scheme based on delay lines, offering the capability to decode the identity of the firing straw with only 2 pre-amplifiers. FIG. 7 illustrates the readout circuit for seven 7-straw bundles (49 straws). On one end of the bundles, all straws with the same index across different bundles are connected together, then to a different tap on delay line 1 . On the other end of the bundles, all straws within the same bundle, are connected together, then to a tap on delay line 2 . In this scheme, delay line 1 identifies the straw index within a single bundle, and delay line 2 identifies the specific bundle among the 7 bundles.
TABLE 1
Boron-coated straw bundle dimensions
and thermal neutron sensitivity.
Detection
Thermal neutron
Bundle
efficiency
sensitivity
Number of straws
Diameter
for thermal
per unit length
in bundle
(cm)
neutrons (%)
[(cps/nv)/cm]
1
(FIG. 4a)
0.4
9.0
0.036
7
(FIG. 4b)
1.27
18.4
0.234
19
(FIG. 4c)
2.12
26.6
0.564
37
(FIG. 4d)
2.97
33.3
0.989
61
(FIG. 4e)
3.82
38.8
1.48
91
(FIG. 4f)
4.67
43.3
2.02
127
(FIG. 4g)
5.52
47.0
2.59
187
(FIG. 4h)
6.36
50.0
3.4 | The present invention is a method and apparatus for operating boron-coated straw detectors in sealed mode, without the need for a continuous flow of gas. Sealed-mode operation is necessary when using the boron-coated straw detectors in the field, where access to a continuous flow of the required gas mixture is not practical. Also, sealed-mode operation is necessary when the straw detectors are used as portable instruments, that must be moved from one location to the next swiftly, or that must be operated while in motion. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to a slow mode control circuit in a video tape recorder, and more particularly to a time difference slow mode control circuit for automatically compensating for reproduction control pulse pick-up error by generating a pseudo reproduction control signal.
In an operation of a tape recorder, a time difference slow mode means that a capstan motor repeats a still mode and a operating mode in turn by which displayed screens on a monitor look like a slow motion. At this time, the capstain motor should be accurately controlled when it repeats the still mode and the operating mode. Accordingly a reproduction control signal is used for an accurate control, because a microcomputer can decide a break time of the capstan motor by picking up the reproduction control signal which is recorded in a control track provided in a lower part of the tape. By reason of tape damage or something else, however, the reproduction control pulse may not be picked up, although the capstan motor is operating.
Operations of the microcomputer and a servo part now will be described with reference to FIG. 2. The servo part generates a head switching pulse with a period illustrated in FIG. 2A. Sensing a slow mode key input from a remote controller or a front panel, the microcomputer generates a step/slow signal as a first pulse mode in order to accelerate the capstan motor after a given time T1 is passed, the time T1 being measured from lowering of the head switching pulse, which is shown in FIG. 2B.
From an opening time of a screen reproduction by the capstan motor operation to a completion time of one frame of screen reproduction for a period of the head switching pulse, the step/slow signal maintains low state. At the completion of one screen reproduction, the servo part produces the reproduction control signal as shown in FIG. 2C. If the reproduction control signal is normally picked up, the microcomputer recognizes this control signal, and produces the step/slow signal of a second pulse mode when a given time T3 has passed after generation of the reproduction control signal. This makes the forwardly operating capstan motor stop, so that the time difference slow mode is achieved. The period T2 from the first pulse generating time to the second pulse generating time is the time required in order to move the tape. The break is applied to the capstan motor lest the period of the tape movement should be over the frame. Therefore, in order to drive the capstan motor in reverse direction for a given time, the microcomputer generates a capstan motor driving direction control signal as shown in FIG. 2E. As a result, the head can read the track exactly. As shown in FIG. 2D, the capstan motor driving signal supplied to the servo part from the microcomputer, keeps a first level L1 until the step/slow signal of the second pulse mode is generated from the driving of the tape, and drops to a second level L2 when the second pulse is generated. Here, the difference between the first level and the second level is needed in order to reduce the tape movement speed. That is, the tape movement speed is lowered at the second level L2, to turn over the tape movement direction.
In the case that the reproduction control pulse is not picked up by the microcomputer even when the capstan motor is operating, the microcomputer cannot provide the motor control signal to the the servo part, so that the servo part cannot exactly apply the break to the capstan motor, thus producing screen hunting or noise. In a conventional slow mode control circuit, however, a method for compensating for such a reproduction control pulse pick-up error is not provided.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a time difference slow mode control circuit which automatically compensates for a reproduction control pulse pick-up error by generating a pseudo reproduction control signal.
In accordance with the present invention, the time difference slow mode control circuit includes a reproduction control signal generator, and a switching part. The reproduction control signal generator has the same frequency as that of a reproduction control signal, and generates a pseudo reproduction control signal which is phase delayed by a half period of a head switching pulse. The switching part, in a time difference slow mode, not only sends the reproduction control signal to the microcomputer when the reproduction control signal is picked up in a time difference slow mode, but also sends the pseudo reproduction control signal to the microcomputer when the reproduction control signal is not picked up.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit of the present invention; and
FIGS. 2A to 2I are waveform diagrams showing signals to explain the overall operation of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
One embodiment of the present invention will now be described in comparison with conventional technology and with reference to the accompanying drawings.
In FIG. 1, a T-type flip-flop FF1 receives a head switching pulse, HSW, shown in FIG. 2A from a servo part C, and divides the frequency of the head switching pulse HSW into two, producing the frequency-divided head switching pulse into two through a non-inverted output terminal, as shown in FIG. 2F. The frequency-divided head switching pulse into two, HSW1, is transferred to a reset terminal of a RS flip-flop FF2. The output of the RS flip-flop FF2 is applied to a base of a first transistor Q1, and turns on or off the first transistor Q1. The comparator COM compares a divided voltage divided by two resistors R1 and R2, with a reference voltage V REF supplied to an inverting terminal (-), the divided voltage being applied to a non-inverting terminal, and generates a pseudo reproduction control signal PBC2. A first supply voltage V CC is supplied to one end of the resistor R1, while the other end of the resistor R1 is connected to one end of the resistor R2, a capacitor C1, and to the non-inverting terminal of the comparator COM. The other end of the resistor R2 is connected to a collector of the transistor Q1. Therefore, the capacitor C1 is charged or discharged depending upon a operational condition of the first transistor Q1, and accordingly, the input voltage level of the non-inverting terminal is decided. The reference voltage V REF of the comparator COM is set up so that the output of the comparator is converted into high state from low state, in the case that the voltage charged by the capacitor C1 and the resistor R1 is higher than the reference voltage V REF .
The operation of the comparator COM according to the input state will now be described. If the second flip-flop FF2 is reset at the leading edge of the frequency-divided head switching pulse into two, HSW1, the first transistor Q1 is turned off, so that the capacitor C1 is charged with charge of the first voltage V CC supplied through the resistor R1. Because the pseudo reproduction control signal PBC2 from the comparator is supplied to the set terminal of the RS flip-flop by a feedback connection, the output terminal QFF2 of the RS flip-flop goes high, and the first transistor Q1 is turned on. Thus, the charge on the condenser C1 is discharged through the first transistor Q1. That is, because according to the switching operation of the first transistor Q1, the high state output of the comparator COM due to the charging operation of the capacitor C1 is inverted to low state output at the discharging operation of the capacitor C1, the comparator COM generates the pseudo reproduction control signal PBC2 synchronized with the leading edge of the head switching pulse HSW1, frequency-divided into two, as shown in FIG. 2G.
The operation processes supplying the reproduction control signal or pseudo reproduction control signal will be described concretely, assuming that the above-described pseudo reproduction control signal is generated.
The servo part C amplifies the reproduction control signal PBC1 received from an audio/control head (not figured), the a reproducing mode control signal being picked up during reproduction. The servo part C sends the amplified reproduction control signal to the microcomputer E. Also the servo part C receives given control signals SIG in slow mode, to thereby control the capstan motor. Here, the control signals SIG related to the time difference slow mode represent the predescribed step/slow signal, capstan motor control signal, a and capstan motor driving direction control signal.
Firstly, in case of normal reproduction of the tape, the microcomputer E produces a high state signal through a mode selection terminal SEL. The transistor Q3 whose base is connected to the mode selection terminal SEL, is turned on. The collector of the transistor Q3 is commonly connected to first and second diodes D1 and D2, and resistor R4; and the reproduction control signal PBC1 and the pseudo reproduction control signal PBC2 are supplied to the collector of the transistor Q3 through the first and second the first diodes D1 and D2, respectively. Accordingly, when the transistor Q3 is turned on, not only is the pseudo reproduction control signal PBC2 bypassed through the collector and the emitter of the transistor Q3, and is not transferred to the microcomputer E, but also the second transistor Q2 keeps the pseudo reproduction control signal from being transferred to the microcomputer E, being in turn-on state when the reproduction control signal PBC1 is picked up by the audio/control head and supplied to the base of the transistor Q2, the transistor Q2 being turned on or off in dependence upon the state of the reproduction control signal PBC1 supplied to the base of the transistor Q2, through a resistor R3, and a capacitor C2 and a resistor R6 which are in parallel with the resistor R3.
Therefore, the reproduction control signal PBC1 picked up from a magnetic tape reproducing head is supplied to a collector and a base of a fourth transistor Q4 through the resistor R5, turning on the fourth transistor Q4. Thus the reproduction control signal PBC1 is bypassed through the collector and emitter Q3, and not transferred to the microcomputer E.
Next, the time difference slow mode will be described. In the time difference slow mode, the signal from the mode selection terminal SEL of the microcomputer E is low state, so that the transistor Q3 is turned off.
If the reproduction control signal PBC1 is normally picked up, the transistors Q2, Q4 are turned on because the voltage level on the bases of the transistors Q2, Q4 is high state. As a result, the reproduction control signal PBC1 is transferred to the reproduction control signal input terminal I1 of the microcomputer E through the transistor Q4 and the diode D1. At this time, the pseudo reproduction control signal PBC2 is not transferred to the reproduction control signal input terminal I1 of the microcomputer because the pseudo reproduction control signal PBC2 is bypassed through the collector and emitter of the second transistor Q2.
On the other hand, if the reproduction control signal is not picked up even when the tape is moving, the transistors Q2 and Q4 are turned off, because the voltage level on the bases of the transistors Q2 and Q4 are both low state. Thus, the pseudo reproduction control signal PBC2 from the comparator COM is applied to the reproduction control signal input terminal I1 through the diode D2 and resistor R4. In the case that the reproduction control signal PBC1 is not picked up, the microcomputer E generates the step/slow signal and the capstan motor driving direction control signal, in response to receipt of the pseudo reproduction control signal, as shown in FIGS. 2H and FIG. 2I, thereby setting the break time of the capstan motor. That is, in the case that the reproduction control signal PBC1 shown in FIG. 2C is not picked up, the microcomputer E receives the second pulse of the pseudo reproduction control signal PBC2 shown in FIG. 2G, generating the second pulse of the step/slow signal shown in FIG. 2H and the capstan motor driving direction control signal shown in FIG. 2I, after a time T4 has elasped from the time a falling edge PBC2 was received by the microcomputer so that the capstan motor can reverse its direction.
As described above, according to the present invention, screen hunting and noise can be prevented, since the pick-up error is automatically compensated for by means of the pseudo reproduction control signal generated from the comparator when the pick-up error arises.
While the present invention has been particularly shown and described with reference to the preferred embodiment thereof, it will be understood by those skilled in the art that foregoing and other changes in form and details may be made without departing from the spirit and scope of the present invention. | A time difference slow mode control circuit of a video tape recorder for controlling a capstan motor by picking up the reproduction control signal from a magnetic tape, in the time difference slow mode, generates delayed phase-delayed pseudo reproduction control signal by a half period of a head switching pulse, the frequency of the pseudo reproduction control signal being the same as that of the reproduction control signal, thus controlling the capstan motor so that the video tape recorder may have a normal time difference slow mode even when a pick-up error arises and thereby improving screen quality. | 6 |
FIELD OF THE INVENTION
The present invention relates in general to backrests, and more particularly an adjustable backrest having independent adjustment of lumbar and upper back height and curvature, as well as overall height adjustment to fit different size patients.
BACKGROUND OF THE INVENTION
Adjustable backrests or supports are well known in the art. U.S. Pat. No. 5,112,106 (Asbjornsen et al) discloses a backrest comprising a central spine or rail to which a lumbar support cushion and head cushion are connected via a sliding element. The sliding element is connected to the rail or spine via a ratchet-like connection. The '106 Patent is of interest for teaching the concept of height adjustable lumbar support where the adjusting means is connected to a spine for sliding engagement therewith.
U.S. Pat. No. 2,756,809 (Endresen) discloses a back support comprising a metal sheet with adjustable lumbar and upper-back portions. A screw adjusts the concavity of the upper-back portion while a further screw adjusts the convexity of the lumbar support portion. A pair of cross bars are provided for supporting and securing the lumbar and upper back portions of the sheet to the backrest. The two adjustment screws are mounted on a pair of sliding plates to provide vertical adjustment of the lumbar support area and the upper-back support area. Accordingly, this patent is of interest for teaching independent height and curvature adjustment of the lumbar support and upper-back support portions of a backrest.
Additional references are known which pertain to adjustable back support or backrests, as follows: U.S. Pat. Nos. 2,843,195; 3,241,879; 3,762,769; 4,153,293; 4,452,458; 4,541,670; 4,601,514; 4,632,454; 4,722,569; 4,909,568; 4,915,448; 4,968,093; 5,026,116; and 5,197,780, as well international patent application No. PCT/AU91/00487 (BackCare and Seating Pty. Ltd.).
While the known prior art backrests disclose the provision of lumbar and upper-back support members with independently adjustable curvature and positioning, none of the known prior art teaches the combinations of height adjustment, lumbar height and curvature adjustment, upper-back curvature and position adjustment and side-to-side mobility. The provision of these features in a backrest is important to ensure proper fitting of the backrest for adult bodies of different height and shapes. Furthermore, human beings tend not to be static but like to move or "fine tune" their sitting positions. The known prior art backrests do not provide adequate side-to-side mobility for such movement. Nor do they allow for the convenient minor adjustment of support. In addition, the known prior art back supports are generally bulky or heavy to carry and occupy excessive space at the bottom portions thereof, thereby leaving very little room to sit on a chair.
SUMMARY OF THE INVENTION
According to the present invention, a backrest is provided in which lumbar height and curvature adjustment are provided along with overall height adjustment to fit different sized persons. Additionally, upper-back curvature and height adjustment are provided along with side adjustment to suit each half side of the human back (i.e. for accommodating different torso shapes). Also, side-to-side mobility is provided to accommodate twisting movements of the human back which are common when a person is sitting (e.g. turning to reach something, or "fine tuning" of one's sitting position). Furthermore, according to the backrest of the present invention a slight hollow is provided just above the base of the backrest to allow for curvature and space so that the backrest does not occupy excessive space on a chair.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the backrest according to the present invention resting on a chair;
FIG. 2 is a cross section along lines II--II of FIG. 1;
FIG. 3 is a rear perspective view of the backrest according to the present invention;
FIGS. 4A and 4B are cross sectional views along the lines IV--IV of FIG. 3 showing curvature adjustment of the lumbar support and upper back support of the backrest according to the present invention;
FIG. 5 is a front perspective view of the backrest according to the present invention with back pads shown in phantom; and
FIG. 6 is an exploded front perspective view of the structural details of the backrest according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning first to FIG. 1, the backrest of the present invention is shown comprising a generally triangular upper portion 1 and base portion 3 resting on the seat of chair C. The triangular profile of upper portion 1 facilitates side-to-side movement of a person using the backrest of the present invention. Also, the hollow portion between the portion 1 and base portion 3 ensures that the backrest does not occupy excessive space on the chair C.
Turning to the remaining FIGS. 2-6, the details of construction of the preferred embodiment are illustrated. A spine 5, preferably of rigid aluminum, forms a central support portion of the backrest to which all other parts are attached. The spine 5 is fabricated to form a pair of cylindrical channels 7 and 9 intermediate a groove 11. As will be discussed in greater detail below, the spine 5 also includes a plurality of slots and apertures for the connection and securing of the various other parts.
A lumbar spring 13 has a projection 15 from a bottom end thereof which is shaped so as to be received in a clip 17. The clip 17 is riveted into spine 5 via a rivet 19 or other suitable attachment means. Thus, the lower portion of lumbar spring 13 is rigidly connected to the spine 5. As will be discussed in greater detail below, an upper portion of the lumbar spring 13 contains a projection 21 which is adapted to slide within the groove 11 of the spine 5 to permit curvature adjustment of the lumbar spring 13.
A cross bar 23 is provided in the form of a flat piece of metal (e.g. steel) which is resilient for contributing to side-to-side mobility of the backrest. The cross bar 23 is attached to back pad 4a as discussed in greater detail below.
An adjustment strap 25 is provided with a clip 27 at one looped end thereof and a D-ring 29 at an opposite looped end thereof. The end with clip 27 is dimensioned to pass through an aperture 31 in the spine of 5 as shown by the arrow in FIG. 6 such that the clip 27 may be secured to one of a plurality of slots 33 in the spine.
At the other end, the projection 21 of lumbar spring 13 is dimensioned to pass through D-ring 29 which remains on an opposite side of the spine 5 from the clip 27 and is adapted to slide within the groove 11 thereof, as will be discussed in greater detail below.
According to an important aspect of the present invention, curvature of the lumbar spring 13 may be adjusted. Turning to FIGS. 4A and 4B, the manner of such adjustment is shown. In order to adjust the curvature of spring 13, the clip 27 at the lower looped end of adjustment strap 25 is removed from one of the slots 33 in spine 5 by pulling downwardly against the tension of the spring 13 and releasing. Pulling of the adjustment strap 25 is facilitated by the loop 39 through which a finger may be inserted. Once the clip 27 has been removed from the slot 33, as shown in FIG. 4B, curvature of the lumbar spring 13 may be decreased by allowing the adjustment strap 25 to be released upwardly toward the slot 31 in spine 5. Alternatively, as shown in FIG. 4B, by pulling downwardly on the adjustment strap 25, D-ring 29 pulls the projection 21 of lumbar spring 13 downwardly, thereby increasing the curvature of the spring in the direction of the arrow.
An upper back spring 35 is provided having a slot 37 at a base portion thereof through which the projection 21 is adapted to be inserted (shown best in FIGS. 5 and 6).
According to another important aspect of the invention, independent curvature of the upper back spring 35 is also provided. A cylindrical tube 41 is capped on both sides via end caps 43, and is secured to the spine 5 via retention spring 45 which slides within the groove 11 and which is riveted to the upper back support tube 41 via rivet 47. By pushing the tube 41 downwardly in the direction of the arrow in FIG. 4B, the upper back spring 35 assumes a greater degree of curvature (i.e. concavity), as illustrated. In addition, the tube 41 may be easily removed in order to remove any curvature in the upper back spring 35.
A back pad 49 (FIG. 5) is provided with a pair of adjustment straps 51 and 53 having hook and loop type fasteners thereon (i.e. velcro™) which pass through a pair of slots 55 in the back pad 49 in order to adjust the contour of back pad 49, as discussed in greater detail below. Each of these straps is independently and individually adjustable of each other allowing for precise side-to-side contouring.
The back pad 49 is connected to the upper spring 35 via a screw (not shown) or other attachment means passing through holes 57 and 59 (FIG. 5). The back pad 49 is connected at a lower end thereof to a further retention spring 61 which slides within the groove 11. Back pad 49 is connected to retention spring 61 via rivet 63 and hole 65 (FIG. 5). Thus, the back pad 49 is free to move upwardly and downwardly relative to the spine 5 as a result of the sliding connection of retention spring 61, upper back support spring 35 and cross bar 23 which is mounted to lumbar support spring 13.
As shown in FIGS. 1, 2 and 3, the back pad 49 is covered by a suitable fabric and foam cover 67 which provides a soft cushion for receiving the human back, the overall vertical profile of the cushion being dictated by the curvatures of the lumbar support spring 13, upper back support spring 35 and back pad curvature adjustment straps 51 and 53. As shown in FIG. 3, the back pad adjustment straps are attached via rivets or other suitable means to the back pad 49 via apertures 69, and extend through the rear of the fabric and foam cushion 67 via slots 71 and 73 for connection rearwardly of the backrest to suitable hook-and-loop (i.e. Velcro™) fasteners 75 (see FIGS. 2 and 3). By pulling on the adjustment straps 51 and 53, the curvature of the back pad 49 and hence the cushion 67 covering it, is caused to increase in the direction of the arrows shown in FIG. 3.
The base portion 3 of the backrest includes a wire foot 77 covered with self skinning plastic foam 79. As shown in FIG. 6, cylindrical end portions of the wire foot 77 are adapted to slide within the cylindrical holes 7 and 9 (FIG. 2) of the spine 5 for upward and downward sliding movement of the wire foot 77 as shown with reference to the arrows at the bottom of FIG. 3. The wire foot 77 is secured in place relative to spine 5, after height adjustment, by means of a pair of screws 80 and corresponding nuts 82.
A self skinning wire head 81 is inserted into the tubular grooves 7 and 9 at the top of spine 5 to provide a pleasing aesthetic finish and an integral carrying handle. The wire head 81 is secured within spine 5 via a pair of screws 83 and corresponding nuts 85 which cause the grooves 7 and 9 to close around the wire head 81. In order to assemble the backrest according to the present invention, cross bar 23 is first attached to the lumbar spring 13 using very high bond tape, or other suitable material, as discussed above. The Velcro™ adjustment straps 51 and 53 and the cross bar 23 are then riveted to back pad 49. Lumbar spring 13 and upper back spring 35 are hooked together as shown in FIG. 6, and the upper back spring 35 is riveted to the back pad 49 as discussed with reference to FIG. 5. The retention spring 61 is riveted to the back pad 49 through hole 65 (FIG. 5).
Clip 27 is then riveted to the lumbar adjustment strap 25, forming a loop 39.
Wire foot 77 is inserted into the spine 5 and fastened into place with machine screws 80 and nuts 82. Loop 29 is hooked to the lumbar spring 13 and this assembly is then made to slide into the channel 11 in the spine 5. The lumbar adjustment strap 25 is then inserted through the D-shaped loop and riveted to the end thereof, and the opposite looped end 39 of the strap 25 is pushed through slot 31 at the back of the spine 5. The assembly comprising lumbar spring 13, D-shaped loop 29 and upper back spring 35 is pulled downwardly to allow the retention spring 61 to slide into the spine 5 from the bottom. The assembly is then pulled back up and the bottom end 15 of the lumbar spring 13 is hooked into clip 17.
Next, the retention spring 45 is riveted to the upper back support tube 41. End caps 43 are inserted into the sides of the upper back support tube 41, and the assembly comprising the upper back support spring 35 and retention spring 45 are inserted into the channel 11 of spine 5 from the top.
The wire head 81 is then inserted into the top of the spine 5, the fabric and foam cover 67 is placed over the back pad 49, and the various straps 25, 51 and 53 are adjusted for personal setting.
In summary, according to the present invention, an adjustable backrest is provided having independent lumbar height and depth adjustment, overall height adjustment to fit different sized patients, mid-back curve height adjustment, side adjustment to suit each half of a patient's back, upper back side-to-side mobility so that the patient can turn from side-to-side, and a hollow portion just above the base to allow curvature and room so that the backrest of the present invention does not occupy excessive space on the chair. Furthermore, the backrest according to the preferred embodiment is portable, and can be affixed to office chairs, car seats, wheelchairs, etc.
Other embodiments and modifications of the invention are contemplated. For example, in a further alternative embodiment the backrest of the present invention may be incorporated integrally within a chair, rather than being portable as provided in the preferred embodiment. This further alternative embodiment nonetheless offers all of the advantages of independent adjustability provided by the preferred embodiment. This and all other modifications and embodiments are believed to be within the sphere and scope of the invention as defined by the claims appended hereto. | An adjustable backrest for supporting a human back comprising a straight spine member; a lumbar support member projecting from the straight spine member; an upper back support member projecting from the straight spine member adjacent the lumbar support member; a back pad resting on the lumbar support member and the upper back support member for supporting the human back; means for adjusting curvature of the lumber support member and means for adjusting curvature of the upper back support member to accommodate different shapes of the human back; means for providing side-to-side mobility of the back pad to accommodate twisting movement of the human back. | 1 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a circuit device and a method for fabricating the same, and in particular to a thin circuit device which is able to achieve multi-layer path, using two sheets of conductive layers, and a method for fabricating the same.
[0003] 2. Description of the Prior Arts
[0004] Recently, IC packages have been actively employed in portable devices, and small-sized and high density assembly devices. Conventional IC packages and assembly concepts tends to greatly change. For example, this is described in, for example, Japanese Laid-Open Patent Publication No. 2000-133678. This pertains to a technology regarding a semiconductor apparatus in which a polyimide resin sheet being a flexible sheet is employed as one example of insulation resin sheets.
[0005] [0005]FIG. 12 through FIGS. 14A,14B and 14 C show a case where a flexible sheet 50 is employed as an interposer substrate. Also, the views illustrated upside of the respective drawings are plan views, and the views illustrated downside thereof are longitudinally sectional views taken along the lines A-A of the respective drawings.
[0006] First, copper foil patterns 51 are prepared to be adhered to each other via an adhesive resin on the flexible sheet 50 illustrated in FIG. 12. These copper foil patterns 51 have different patterns, depending upon cases where a semiconductor element to be assembled is a transistor or an IC. Generally speaking, a bonding pad 51 A and an island 51 B are formed. Also, an opening 52 is provided to take out an electrode from the rear side of the flexible sheet 50 , from which the above-described copper foil pattern 51 is exposed.
[0007] Subsequently, the flexible sheet 50 is transferred onto a die bonder, and as shown in FIG. 13, a semiconductor element 53 is assembled or mounted. After that, the flexible sheet 50 is transferred onto a wire bonder, wherein the bonding pads 51 A are electrically connected to the pads of the semiconductor elements 53 by thin metal wires 54 .
[0008] Finally, as shown in FIG. 14A, sealing resin 55 is provided on the surface of the flexible sheet 50 , and the surface thereof is completely sealed with the sealing resin 55 . Herein, the bonding pads 51 A, island 51 B, semiconductor elements 53 and thin metal wires 54 are transfer-molded so as to be completely overcoated.
[0009] After that, as shown in FIG. 14B, connecting means 56 such as solder and a soldering ball is provided, wherein spherical solder 56 deposited to the bonding pad 51 A is formed via the opening 52 by passing through a solder reflow furnace. Further, since semiconductor elements 53 are formed in the form of a matrix on the flexible sheet 50 , these are diced to be separated from each other as shown in FIGS. 14.
[0010] In addition, the sectional view of FIG. 14C shows electrodes 51 A and 51 D on both sides of the flexible sheet 50 as the electrodes. The flexible sheet 50 is generally supplied from a maker after both sides thereof are patterned.
[0011] Since a semiconductor apparatus that employs the above-described flexible sheet 50 does not utilize any publicly known metal frame, the semiconductor apparatus has a problem in that a multi-layer connection structure cannot be achieved while it has an advantage by which a remarkably thin package structure can be brought about, wherein path is carried out with one layer of copper foil pattern 51 , which is provided substantially on the surface of the flexible sheet 50 .
[0012] It is necessary to make the flexible sheet 50 sufficiently thick, for example, approx. 200 μm, in order to retain supporting strength to achieve a multi-layer connection structure. Therefore, there is a problem of retrogression with respect to thinning of the sheet.
[0013] Further, in the method for fabricating a circuit device, a flexible sheet 50 is transferred in the above-described fabrication apparatus, for example, a die bonder, wire bonder, a transfer mold apparatus, and a reflow furnace, etc., and the flexible sheet 50 is attached onto a portion called a “stage” or a “table”.
[0014] However, if the thickness of the insulation resin that becomes the base of the flexible sheet 50 is made thin, for example, 50 μm, the flexible sheet 50 may be warped as shown in FIG. 15 or its transfer performance may be remarkably worsened where the thickness of the copper foil pattern 51 formed on the surface thereof is thin to be 9 through 35 μm. In addition, another problem arises in that the flexible sheet 50 is defectively attached to the above-described stage or table. This is because it is considered that the resin is warped since the insulation resin itself is very thin, and the resin is warped due to a difference in the thermal expansion coefficient between the copper foil pattern 51 and the insulation resin. Particularly, still another problem exists in that, if a hard insulation material not having any core material of glass cloth fibers is warped as shown in FIG. 15, the hard insulation material may be easily collapsed due to compression from above.
[0015] Since the portion of the opening 52 is compressed from above when being molded, a force by which the periphery of the bonding pad 51 A is warped upward is brought about, the adhesion of the bonding pad 51 A is worsened.
[0016] Also, the resin material that constitutes a flexible sheet 50 has less flexibility, or if a filler to increase the thermal conductivity is blended, the flexible sheet 50 is made hard. In such a case, where bonding is carried out by a wire bonder, there may be a case where the bonded portion is cracked. Also, when performing transfer molding, there is a case where the portion with which a metal die is brought into contact is cracked. This remarkably occurs if any warping shown in FIG. 15 is provided.
[0017] Although the flexible sheet 50 described above is such a type that no electrode is formed on the rear side thereof, there are cases where an electrode 51 D is formed on the rear side of the flexible sheet 50 as shown in FIG. 14C. At this time, since the electrode 51 D is brought into contact with the above-described fabrication apparatus or is brought into contact with the transfer plane of transfer means between the fabrication apparatuses, another problem occurs in that damage and scratches arise on the rear side of the electrode 51 D, wherein the electrode is established with such damage and scratches retained, the electrode 51 itself may be cracked due to application of heat later on.
[0018] Also, if an electrode 51 D is provided on the rear side of the flexible sheet 50 , a problem occurs in that, when carrying out transfer molding, no facial contact with the stage can be secured. In this case, if the flexible sheet 50 is composed of a hard material as described above, the electrode 51 D becomes a fulcrum and the periphery of the electrode 51 D is compressed downward, wherein the flexible sheet 50 is cracked.
SUMMARY OF THE INVENTION
[0019] The present invention was developed in view of the above-described problems and shortcomings. First, in view of the structure, these problems and shortcomings can be solved by a circuit device including: a first conductive layer; a second conductive layer; insulation resin by which the above-described first conductive layer and the above-described second conductive layer are adhered to each other in the form of a sheet; a first conductive path layer that is formed by etching the above-described first conductive layer; a second conductive path layer that is formed by etching the above-described second conductive layer; a semiconductor element electrically insulated and fixed on the above-described first conductive path layer; multi-layer connecting means for connecting the above-described first conductive path layer and the above-described second conductive path layer to each other at appointed points, passing through the above-described insulation resin; a sealing resin layer for overcoating the above-described first conductive path layer and the above-described semiconductor element; and an external electrode secured at an appointed point of the above-described second conductive path layer.
[0020] The first conductive layer and the second conductive layer are electrically insulated from each other by remarkably thin insulation resin, and are made into a physically integrated sheet. The first conductive path layer is formed by the first conductive layer, and the second conductive path layer is formed by the second conductive layer, wherein the first conductive path layer and the second conductive path layer are connected to each other by multi-layer connecting means to bring about a multi-layered path structure.
[0021] Also, the semiconductor element is electrically insulated from the first conductive path layer by overcoating resin and is adhered and fixed thereat, wherein the first conductive path layer can be freely lead on the lower part of the semiconductor element.
[0022] Secondly, in view of the method for fabricating a circuit device, the above-described problems and shortcomings can be solved by a method for fabricating a circuit device, which comprises the steps of: preparing a circuit substrate sheet in which the first conductive layer and the second conductive layer are adhered to each other by insulation resin; forming through holes in the above-described first conductive layer and the above-described insulation resin at an appointed point of the above-described circuit substrate, and selectively exposing the above-described second conductive layer; forming multi-layer connecting means in the above-described through holes and electrically connecting the above-described first conductive layer and the above-described second conductive layer to each other; forming a first conductive path layer by etching the above-described first conductive layer to an appointed pattern; electrically insulating a semiconductor element and adhering and fixing the above-described semiconductor element on the above-described first conductive path layer; overcoating the above-described first conductive path layer and the above-described semiconductor element with a sealing resin layer; forming a second conductive path layer by etching the above-described second conductive layer to an appointed pattern; and forming an external electrode at an appointed point of the above-described second conductive path layer.
[0023] Since the flexible sheet is formed to be thick by the first conductive layer and the second conductive layer, the flatness of a sheet-shaped circuit substrate can be maintained even if the insulation resin is thin.
[0024] Before the step of overcoating the first conductive path layer and semiconductor elements by a sealing resin layer, the mechanical strength of the first conductive path layer and semiconductor elements can be retained by the second conductive layer. After that, the mechanical strength is brought about by the sealing resin layer. Therefore, it is possible to easily form the second conductive path layer by the second conductive layer. As a result, the insulation resin does not need any mechanical strength, wherein it is possible to make the insulation resin thin to the thickness by which electrical insulation can be maintained.
[0025] Further, since the lower die mold and planes of a transfer molding apparatus are brought into contact with the entirety of the second conductive layer, no local compression is brought about, and it is possible to prevent the insulation resin from being cracked.
[0026] Still further, since the first conductive layer can form the first conductive path layer after a multi-layer connecting means is formed in through holes, the multi-layer connecting means can be formed without any mask.
[0027] A circuit device according to the invention has the following advantages in view of structure.
[0028] First, since the first conductive layer is formed to be thin, the first conductive path layer can be finely patterned, wherein a semiconductor element whose number of electrode pads is 100 or more can be built in.
[0029] Second, since the semiconductor element is electrically insulated from the first conductive path layer by overcoating resin, path can be routed below the semiconductor element, wherein a freedom of routing the first conductive path layer can be remarkably increased, and a multi-layered connecting structure can be brought about.
[0030] Third, in comparison with cases where conventional glass epoxy resin substrates and interposer substrates such as flexible sheets are used, the mechanical strength can be retained by the second conductive layer and the sealing resin layer by employment of an insulation resin sheet, wherein a remarkably thin structure can be achieved.
[0031] Fourth, since low-temperature resin or super low-temperature resin is employed as the insulation resin, not only can be the insulation resin made thin but also the thermal resistance thereof can be remarkably decreased, wherein heat of the semiconductor elements can be immediately irradiated.
[0032] In addition, a method for fabricating the circuit device according to the invention has the following advantages.
[0033] First, warping of the insulation resin sheet can be solved by the second conductive layer, and transfer performance thereof can be improved.
[0034] Second, since through holes, which are formed in an insulation resin, are prepared by a carbonic acid gas laser, plating for multi-layer connecting means can be carried out immediately thereafter, the process can be made remarkably simple. Also, if copper plating is used as the multi-layer connecting means, the first conductive layer and the second conductive layer can be made of the same material (copper), the processes after that can be made simple.
[0035] Third, since the multi-layer connecting means is achieved by a plated layer, the multi-layer connecting means can be formed without any mask before the first conductive path layer is formed. Since patterning can be performed simultaneously with the formation of the first conductive path layer, it becomes remarkably simple to form the multi-layer connecting means.
[0036] Fourth, since the mechanical support of the insulation resin sheet is retained by the second conductive layer until the sealing resin layer is formed, and the mechanical support of the insulation resin sheet is retained by the sealing resin layer after the second conductive path layer is formed, the mechanical strength of the insulation resin is disregarded, wherein a remarkably thin assembly method can be achieved.
[0037] Fifth, since both sides of the insulation resin are covered by the first and second conductive layer even where the insulation resin itself is hard or becomes hard by a filler being blended therein, flatness of the insulation resin sheet itself can be increased in the fabrication process, and it is possible to prevent cracks from occurring.
[0038] Sixth, since the insulation resin sheet has a second conductive layer thickly formed on its rear side, the insulation resin sheet can be utilized as a support substrate for die bonding of chips and for sealing a wire bonder and semiconductor elements. In addition, where the insulation resin material itself is soft, propagation of energy for wire bonding can be improved, and the wire bondability can be further improved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] [0039]FIG. 1 is a sectional view describing a circuit device according to the invention;
[0040] [0040]FIG. 2 is a plan view describing a circuit device according to the invention;
[0041] [0041]FIG. 3 is a sectional view describing a method for fabricating a circuit device according to the invention;
[0042] [0042]FIG. 4 is a sectional view describing a method for fabricating a circuit device according to the invention;
[0043] [0043]FIG. 5 is a sectional view describing a method for fabricating a circuit device according to the invention;
[0044] [0044]FIG. 6 is a sectional view describing a method for fabricating a circuit device according to the invention;
[0045] [0045]FIG. 7 is a sectional view describing a method for fabricating a circuit device according to the invention;
[0046] [0046]FIG. 8 is a sectional view describing a method for fabricating a circuit device according to the invention;
[0047] [0047]FIG. 9 is a sectional view describing a method for fabricating a circuit device according to the invention;
[0048] [0048]FIG. 10 is a sectional view describing a method for fabricating a circuit device according to the invention;
[0049] [0049]FIG. 11 is a sectional view describing another circuit device according to the invention;
[0050] [0050]FIG. 12 is a view describing a method for fabricating a semiconductor according to prior arts;
[0051] [0051]FIG. 13 is a view describing a method for fabricating a semiconductor according to prior arts;
[0052] [0052]FIGS. 14A, 14B and 14 C are views describing a method for fabricating a semiconductor according to prior arts;
[0053] [0053]FIG. 15 is a view describing a prior art flexible sheet.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment Describing a Circuit Device
[0054] A circuit device according to the invention is comprised, as shown in FIG. 1, of a first conductive layer 3 ; a second conductive layer 4 ; insulation resin 2 by which the above-described first conductive layer 3 and the above-described second conductive layer 4 are adhered to each other in the form of a sheet; a first conductive path layer 5 that is formed by etching the above-described first conductive layer 3 ; a second conductive path layer 6 that is formed by etching the above-described second conductive layer 4 ; a semiconductor element 7 electrically insulated and fixed on the above-described first conductive path layer 5 ; multi-layer connecting means 12 for connecting the above-described first conductive path layer 5 and the above-described second conductive path layer 6 to each other at appointed points, passing through the above-described insulation resin 2 ; a sealing resin layer 13 for overcoating the above-described first conductive path layer 5 and the above-described semiconductor element 7 ; and an external electrode 14 secured at an appointed point of the above-described second conductive path layer 6 .
[0055] First, a description is given of an insulation resin sheet. In FIG. 3, the entirety is an insulation resin sheet 1 . The intermediate layer is insulation resin 2 . The first conductive layer 3 is formed on the surface of the insulation resin 2 , and the second conductive layer 4 is formed on the rear side thereof.
[0056] That is, the first conductive layer 3 is formed on substantially the entire surface of the insulation resin sheet 1 , and the second conductive layer 4 is formed on substantially the entire rear side thereof. The material of the insulation resin 2 is an insulation material composed of macromolecules such as polyimide resin or epoxy resin, etc. In addition, the first conductive layer 3 and the second conductive layer 4 are, preferably, mainly composed of copper (Cu), or a publicly known material of a lead frame, and the layer 3 and 4 are coated on the insulation resin 2 by a plating method, a deposition method, or a spattering method, or a metallic foil formed by a rolling method or a plating method may be adhered thereto.
[0057] Also, the insulation resin sheet 1 may be formed by a casting method. Hereinafter, a brief description is given of the casting method. First, glue type polyimide resin is coated on the first conductive layer of a flat film, and glue type polyimide resin is coated on the second conductive layer of a flat film. Then, by adhering the two sheets of polyimide resin together after the polyimide is semi-hardened, an insulation resin sheet 1 can be fabricated. Therefore, the insulation resin sheet 1 does not require any glass cloth fibers for reinforcement.
[0058] A characteristic point of the invention resides in that the second conductive layer 4 is made thicker than the first conductive layer 3 .
[0059] The first conductive layer 3 is formed to become 5 through 35 μm thick, so that a fine pattern can be fabricated by making the layer 3 as thin as possible. The second conductive layer 4 may be formed to become 70 through 200 μm thick, wherein emphasis is placed on the supporting strength.
[0060] Therefore, the flatness of the insulation resin sheet 1 can be maintained by forming the second conductive layer 4 thicker than the layer 3 , wherein workability of subsequent processes can be improved, and it becomes possible to prevent the insulation resin 2 from being cracked or to prevent cracks from being brought about.
[0061] Since the overcoating resin can be hardened while maintaining the flatness, the rear side of a package can be made flat, and electrodes formed on the rear side of the insulation resin sheet 1 can be disposed to be flat, whereby the electrodes on an assembly substrate can be brought into contact with those on the rear side of the insulation resin sheet 1 , and it is possible to prevent solder from becoming defective.
[0062] Polyimide resin, epoxy resin, etc., are preferably used as the insulation resin 2 . In the case of a casting method in which paste-like resin is coated to fabricate a sheet, the layer thickness is 10 through 100 μm. Also, in a case of forming the insulation resin 2 as a sheet, a sheet that is available on the market has a minimum thickness of 25 μm. Also, a filler may be blended therein in consideration of thermal conductivity. Glass, Si oxide, aluminum oxide, Al nitride, Si carbide, boron nitride, etc., are considered as materials of the filler.
[0063] As described above, the insulation resin 2 maybe selected from resin having low thermal resistance, or that having super low thermal resistance, in which the above-described filler is blended, or polyimide resin. These resins may be selectively used, depending upon the characteristics of a circuit device to be formed.
[0064] The first conductive path layer 5 is formed by etching the first conductive layer 3 . The first conductive layer 3 is formed to become 5 through 35 μm thick, and bonding pads 10 and the first conductive path layer 5 extending from these bonding pads 10 to the center of a substrate are formed by etching at the periphery thereof. A finer pattern is requisite in line with an increase in the number of pads of semiconductor elements to be incorporated.
[0065] The second conductive path layer 6 is formed by etching the second conductive layer. The second conductive layer 4 is 70 through 200 μm thick, and is not suitable for making a pattern fine. However, the second conductive layer is used to mainly form an external electrode 14 , and multi-layer path can be formed as necessary.
[0066] The semiconductor element 7 is adhered to and fixed on the overcoating resin 8 , which overcoats the first conductive path layer 5 , by an adhesive resin. The semiconductor element 7 and the first conductive path layer 5 are electrically insulated from each other. As a result, the first conductive path layer 5 of a fine pattern can be freely routed below the semiconductor element 7 , wherein the freedom of path can be remarkably increased. Respective electrode pads 9 of the semiconductor element 7 are connected to the bonding pads 10 , which are parts of the first conductive path layer 5 secured at the periphery, by bonding wires 11 . In addition, the bonding pads 10 have their surfaces plated with gold or silver in order to ensure bonding.
[0067] The multi-layer connecting means 12 connects the first conductive path layer 5 and the second conductive path layer 6 together at appointed points through the insulation resin 2 . In detail, a copper-plated layer is suitable as the multi-layer connecting means 12 . Also, a plated layer of gold, silver, palladium, etc., may be acceptable.
[0068] The sealing resin layer 13 overcoats the first conductive path layer 5 and the semiconductor element 7 . The sealing resin layer 13 is concurrently used to function as a mechanical support of a completed circuit device.
[0069] The external electrode 14 is provided at an appointed point of the second conductive path layer 6 . That is, almost all the parts of the second conductive path layer 6 are overcoated with overcoating resin 15 , and an external electrode 14 formed of solder is provided on the exposed parts of the second conductive path layer 6 .
[0070] With reference to FIG. 2, a description is given of a detailed circuit device according to the invention. First, patterns shown with solid lines indicate the first conductive path layers 5 , and patterns shown with dashed lines indicate the second conductive path layers 6 . The first conductive path layers 5 are provided with bonding pads 10 at their peripheries so that the bonding pads surround the semiconductor elements 7 and correspond to semiconductor elements 7 having multiple pads, which are disposed in two stages. The bonding pad 10 is connected to an electrode pad 9 , to which the semiconductor element 7 corresponds, by a bonding wire 11 , and a number of the first conductive path layers 5 of a fine pattern extend below the semiconductor element 7 from the bonding pad 10 , and are connected to the second conductive path layer 6 by the multi-layer connecting means 12 shown with black circles.
[0071] In such a structure, a semiconductor element having 200 or more pads is caused to extend, in the form of a multi-layer path structure, to an appointed second conductive path layer 6 , utilizing a fine pattern of the first conductive path layer 5 , and connection from the external electrode 14 , which is provided on the second conductive path layer 6 , to peripheral circuits can be carried out.
Second Embodiment Describing a Method for Fabricating a Circuit Device
[0072] A description is given of a method for fabricating a circuit device according to the invention with reference to FIG. 1 through FIG. 10.
[0073] A method for fabricating a circuit device according to the invention comprises the steps of: preparing an insulation resin sheet 1 in which the first conductive layer 3 and the second conductive layer 4 are adhered to each other by insulation resin 2 ; forming through holes 21 .in the above-described first conductive layer 3 and the above-described insulation resin 2 at an appointed point of the above-described insulation resin sheet 1 , and selectively exposing the rear side of the above-described second conductive layer 4 ; forming multi-layer connecting means 12 in the above-described through holes 21 and electrically connecting the above-described first conductive layer 3 and the above-described second conductive layer 4 to each other; forming a first conductive path layer 5 by etching the above-described first conductive layer 3 to an appointed pattern; electrically insulating a semiconductor element 7 and adhering and fixing the above-described semiconductor element 7 on the above-described first conductive path layer 5 ; overcoating the above-described first conductive path layer 5 and the above-described semiconductor element 7 with a sealing resin layer 13 ; forming a second conductive path layer 6 by etching the above-described second conductive layer 4 to an appointed pattern; and forming an external electrode 14 at an appointed point of the above-described second conductive path layer 6 .
[0074] The first step of the invention prepares an insulation resin sheet 1 in which the first conductive layer 3 and the second conductive layer 4 are adhered to each other by the insulation resin 2 as shown in FIG. 3.
[0075] The first conductive layer 3 is formed on substantially the entire surface of the insulation resin sheet 1 , and the second conductive layer 4 is formed on substantially the entire rear side thereof. In addition, the material of the insulation resin 2 is an insulation material composed of macromolecules such as polyimide resin or epoxy resin, etc. In addition, the first conductive layer 3 and the second conductive layer 4 are, preferably, mainly composed of copper (Cu), or a publicly known material of a lead frame, and the layer 3 and 4 are coated on the insulation resin 2 by a plating method, a deposition method, or a spattering method, or a metallic foil formed by a rolling method or a plating method may be adhered thereto.
[0076] Also, the insulation resin sheet 1 may be formed by a casting method. Hereinafter, a brief description is given of the casting method. First, glue type polyimide resin is coated on the first conductive layer 3 of a flat film, and glue type polyimide resin is coated on the second conductive layer 4 of a flat film. Then, by adhering the two sheets of polyimide resin together after the polyimide is semi-hardened, an insulation resin sheet 1 can be fabricated.
[0077] A characteristic point of the invention resides in that the second conductive layer 4 is formed to be thicker than the first conductive layer 3 .
[0078] The first conductive layer 3 is formed to be 5 through 35 μm thick, and is made as thin as possible so that a fine pattern can be formed. The second conductive layer 4 may be formed to become 70 through 200 μm thick, wherein emphasis is placed on the supporting strength.
[0079] Polyimide resin, epoxy resin, etc., are preferably used as the insulation resin 2 . In the case of a casting method in which paste-like resin is coated to fabricate a sheet, the layer thickness is 10 through 100 μm. Also, in a case of forming the insulation resin 2 as a sheet, a sheet that is available on the market has a minimum thickness of 25 μm. Also, a filler may be blended therein in consideration of thermal conductivity. Glass, Si oxide, aluminum oxide, Al nitride, Si carbide, boron nitride, etc., are considered as materials of the filler.
[0080] As described above, the insulation resin 2 maybe selected from resin having low thermal resistance, or that having super low thermal resistance, in which the above-described filler is blended, or polyimide resin. These resins may be selectively used, depending upon the characteristics of a circuit device to be formed.
[0081] The second step according to the invention forms through holes 21 in the first conductive layer 3 and the insulation resin 2 at appointed points of the insulation resin sheet 1 as shown in FIG. 4, and selectively exposes the second conductive layer 4 .
[0082] The entire surface is overcoated with photo-resist with only the portion exposed where the through holes 21 of the first conductive layer 3 are formed. And, the first conductive layer 3 is etched via the photo resist. Since the first conductive layer 3 is composed of Cu as the main material, chemical etching is carried out by using ferric chloride or cupric chloride as the etching solution. Although the opening diameter of the through holes 21 may change depending upon degree of photography resolution, herein, the diameter is 50 through 100 μm or so. Further, when carrying out etching, the second conductive layer 4 is protected from an etching solution by covering the same with an adhesive sheet. However, where the second conductive layer 4 is sufficiently thick and has a thickness by which the flatness can be maintained after etching, the second conductive layer 4 may be slightly etched. In addition, Al, Fe, Fe—Ni or a publicly known lead frame material may be acceptable as the first conductive layer 3 .
[0083] Subsequently, using the first conductive layer 3 as a mask after removing the photo resist, the insulation resin 2 that is immediately below the through holes 21 is removed by a laser, and the rear side of the second conductive layer 4 is exposed on the bottom of the through holes 21 . A carbonic acid gas laser is preferably used as the laser. In addition, where any residue remains on the bottom of the opening portion after the insulation resin is evaporated by the laser, wet etching is carried out, by using permanganic acid soda or persulphuric acid ammonium, in order to remove the residue.
[0084] With the step, where the first conductive layer 3 is thin at 10 μm or so, the first conductive layer 3 and the insulation resin 2 are collectively removed by the carbonic acid gas laser after portions other than the through holes 21 are overcoated with photo resist, thereby forming the through holes 21 . In this case, a blackening treatment process is required in order to roughen the surface of the first conductive layer 3 in advance.
[0085] The third step according to the invention forms multi-layer connecting means 12 in the through holes 21 as shown in FIG. 5, and may electrically connect the first conductive layer 3 and the second conductive layer 4 .
[0086] A plated layer, which is multi-layer connecting means 12 to permit electric connections between the second conductive layer 4 and the first conductive layer 3 , is formed on the entire surface of the first conductive layer 3 including the through holes 21 . The plated layer is formed by both non-electrolytic plating and electrolytic plating. Herein, Cu of approx. 2 μm is formed on the entire surface of the first conductive layer 3 including at least the through holes 21 by the non-electrolytic plating, whereby since the first conductive layer 3 and the second conductive layer 4 are electrically made conductive, the electrolytic plating is carried out again by using the first conductive layer 3 and the second conductive layer 4 as electrodes to plate Cu approx. 20 μm thick. Thus, the through holes 21 are filled with Cu, and multi-layer connecting means 12 is thus formed. Also, if EBARA-UDYLITE is employed which is the brand name of a plating solution, it is possible to selectively fill in only the through holes 21 . Also, although Cu is employed as the plated layer, Au, Ag, Pd, etc., maybe used. Further, partial plating may be acceptable by using a mask.
[0087] The fourth step according to the invention forms the first conductive path layer 5 by etching the first conductive layer 3 to an appointed pattern as shown in FIG. 6 and FIG. 7.
[0088] The first conductive layer 3 is overcoated with photo-resist of an appointed pattern, and the bonding pads 10 and the first conductive path layer 5 extending from these bonding pads 10 to the center of a substrate are formed by chemical etching. Since the first conductive layer 3 is mainly composed of Cu, the etching solution of ferric chloride or cupric chloride may be used for the chemical etching.
[0089] Since the first conductive layer 3 is formed to be 5 through 35 μm or so, the first conductive path layer 5 may be formed to be a fine pattern which is smaller than 50 μm.
[0090] Continuously, the bonding pads 10 of the first conductive path layer 5 are exposed, and other portions are overcoated with overcoating resin 8 . The overcoating resin 8 is such that epoxy resin, etc., is dissolved with a solvent and is adhered by a screen printing method, and is thermally hardened.
[0091] Also, as shown in FIG. 7, a plating layer 22 of Au, Ag, etc., is formed on the bonding pads 10 in consideration of the bonding property. The plating layer 22 is selectively adhered, by a non-electrolytic plating method, to the bonding pads 10 using the overcoating resin 8 as a mask, or is adhered, by an electrolytic plating method, using the second conductive layer 4 as an electrode.
[0092] The fifth step according to the invention adheres and fixes a semiconductor element 7 on the first conductive path layer 5 after being electrically insulated therefrom as shown in FIG. 8.
[0093] The semiconductor element 7 is die-bonded on the overcoating resin 8 by insulation adhesion resin 25 as it is a bare chip. Since the semiconductor element 7 is electrically insulated from the first conductive path layer 5 immediately therebelow by the overcoating resin 8 , the first conductive path layer 5 can be freely routed below the semiconductor element 7 , thereby achieving a multi-layered path structure.
[0094] Also, respective electrode pads 9 of the semiconductor element 7 are connected to the bonding pads 10 , which are parts of the first conductive path layer 5 secured at the periphery, by bonding wires 11 . The semiconductor elements 7 may be assembled with the faces down. In this case, soldering balls and bumps are provided on the surface of the respective electrode pads 9 of the semiconductor elements 7 , and electrodes similar to the bonding pads 10 are provided at portions corresponding to the positions of the soldering balls on the surface of the insulation resin sheet 1 . (See FIG. 11).
[0095] A description is given of the advantages of using the insulation resin sheet 1 when bonding wires. Generally, when bonding Au wires, heating is carried out around 200 through 300° C. At this time, the insulation resin sheet 1 is warped if the second conductive layer 4 is thin. If the insulation resin sheet 1 is compressed via the bonding head in this state, there is a possibility for the insulation resin sheet 1 to be cracked. This remarkably occurs since, if a filler is blended in the insulation resin 2 , the material itself becomes hard and flexibility is lost. Also, since resin is softer than metals, energy of compression and ultrasonic waves may be dispersed in the bonding of Au and Al. However, if the insulation resin 2 is made thin and the second conductive layer 4 is formed to be thick, these problems can be solved.
[0096] The sixth step according to the invention overcoats the first conductive path layer 5 and the semiconductor element 7 with a sealing resin layer 13 as shown in FIG. 9.
[0097] The insulation resin sheet 1 is set in a molding apparatus and is used for resin molding. Transfer molding, injection molding, coating, dipping, etc., maybe possible as the molding method. However, in consideration of mass production, the transfer molding and injection molding are favorable.
[0098] Although, in this step, it is necessary that the insulation resin sheet 1 is flatly brought into contact with the lower metal die of a mold cavity, the second conductive layer 4 , which is thick, functions like this. In addition, until contraction of the sealing resin layer 13 is completely finished after the insulation resin sheet 1 is taken out from the mold cavity, the flatness of a package can be maintained by the second conductive layer 4 .
[0099] That is, the role of the mechanical support of the insulation resin sheet 1 is retained by the second conductive layer 4 .
[0100] As shown in FIG. 10, the seventh step according to the invention etches the second conductive layer 4 to an appointed pattern and forms the second conductive path layer 6 .
[0101] The second conductive layer 4 is overcoated with photo-resist of an appointed pattern, and the second conductive path layer 6 is formed by chemical etching. Since the second conductive layer 4 is thick, it not suitable for fine patterning. However, since the second conductive layer 4 mainly aims at forming an external electrode 14 , there is no problem. The second conductive path layers 6 are arrayed at fixed intervals as shown in FIG. 2, and the second conductive path layers 6 are electrically connected to each other via the first conductive path layers 5 and multi-layer connecting means 12 , thereby achieving a multi-layered connection structure. Also, if necessary, the second conductive path layer 6 to cross the first conductive path layers 5 at blank portions may be formed.
[0102] The eighth step according to the invention forms, as shown in FIG. 1, external electrodes 14 at appointed points of the second conductive path layer 6 .
[0103] The second conductive path layer 6 has portions, at which the external electrodes 14 are formed, exposed, and almost all the portions of the second conductive path layer 6 are overcoated with an overcoating resin layer 15 by screen-printing of epoxy resin, etc., which is dissolved by a solvent. Next, external electrodes 14 are simultaneously formed at the exposed portions by reflow of solder.
[0104] Finally, since a number of circuit devices are formed on the insulation resin sheet 1 in the form of matrices, the sealing resin layer 13 and insulation resin sheet 1 are diced and are separated for individual circuit devices.
[0105] [0105]FIG. 11 shows a structure in which a semiconductor element 7 is assembled with its face down. Parts which are similar to those in FIG. 1 are given the same reference numbers. A bump electrode 31 is provided at the semiconductor element 7 , and the bump electrode 31 is connected to a bonding pad 10 . Under-filling resin 32 is filled in the gap between the overcoat resin 8 and the semiconductor element 7 . Bonding wires can be removed in this structure, and the thickness of the sealing resin layer 13 can be made thinner. Also, the external electrodes 14 can be achieved by a bump electrode in which the second conductive layer 4 is etched, and the surface thereof is overcoated with a gold- or palladium-plated layer 33 . | An entirely molded semiconductor apparatus in which a flexible sheet having a conductive pattern is employed as a supporting substrate and semiconductor elements are assembled thereon has been developed, wherein such a semiconductor apparatus has various problems by which no multi-layered connection structure is enabled, and warping of insulation resin sheets becomes remarkable in the fabrication process. Therefore, a circuit device and a method for fabricating the same according to the invention solves the above-described and other problems by the structure, wherein an insulation resin sheet in which the first conductive layer 3 and the second conductive layer 4 are adhered to each other by insulation resin 2 is used, the first conductive path layer 5 is formed by the first conductive layer 3, the second conductive path layer 6 is formed by the second conductive layer 4, and both of the conductive path layers are connected by multi-layer connecting means 12. Since a semiconductor element 7 is adhered to and fixed on overcoating resin 8 that covers the first conductive path layer 5, a multi-layer connection structure can be achieved by the first conductive path layer 5 and the second conductive path layer 6. Further, the second conductive layer 4 that is made thick can prevent warping from occurring due to a difference in a thermal expansion coefficient. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to a process for recovering hydrocarbon values from an underground hydrocarbon-bearing formation. More particularly, the invention relates to a process for recovering these hydrocarbons by electrothermal means, wherein the subterranean formation is heated, thus making the hydrocarbon values mobile and recoverable. A broad statement of the complete process includes these steps:
(a) the formation of underground electrodes of enlarged radius,
(b) using the formed electrodes to heat the formation between wells, thus making the hydrocarbon material (bitumen) mobile, and
(c) removal and recovery of the mobile material, such as by a displacing fluid.
The utility of the invention lies in the recovery of hydrocarbons from an underground formation.
Although a majority of petroleum is produced from freely-flowing wells drilled into a subterranean formation, there are many hydrocarbonaceous materials that cannot be produced directly in such a manner--some supplemental operation is required to recover such materials. Secondary and tertiary methods of recovering petroleum are wellknown, such as water-flooding or steam-flooding. If the hydrocarbon values in the underground formation are too viscous or are otherwise retained in the formation, one method of reducing the viscosity or liberating the hydrocarbon values is by the application of heat to the underground formation. Heat energy can be introduced to the underground formation by means of a heated liquid or gas or by the combustion of a portion of the underground hydrocarbon values. Another method of introducing heat energy is by the use of electrical energy in the subterranean formation, resulting in resistance heating.
However, there are problems in heating by electricity. If the temperature in the vicinity of the electrode wellbore is not kept below the vaporization temperature of connate water typically found in the subterranean formation, the removal of this connate water by vaporization effectively hinders the flow of current into the formation, thus limiting the amount of formation heating.
Since the prior art methods of heating a subterranean formation, and thus recovering hydrocarbon values, have not been totally satisfactory, I submit that my invention overcomes the difficulties encountered and offers an improved method of recovering hydrocarbon values from an underground hydrocarbon-bearing formation.
SUMMARY OF THE INVENTION
My invention concerns an electrothermal process for recovering hydrocarbon values from an underground hydrocarbon-bearing formation having at least two separated boreholes penetrating the hydrocarbon-bearing formation, comprising the steps of:
(a) placing a heating device in the first borehole,
(b) energizing the device to heat the surrounding formation to a temperature high enough to produce coking of at least a portion of the hydrocarbon-bearing formation, thus forming a coked zone, which, having conductive properties, acts as an electrode,
(c) maintaining the temperature of step (b) for a length of time to obtain a coked zone electrode having an effective radius at least twice that of the borehole,
(d) repeating steps (a-c) in a second borehole,
(e) applying an electromotive potential between the coked zone electrodes of the first and second boreholes, to heat the formation between the boreholes to a temperature at which the hydrocarbon values are mobile, and
(f) recovering hydrocarbon values from one of said boreholes.
The essence of the invention lies in the formation of an electrode of enlarged effective radius. An electrode well is a well completed with appropriate electrical features so it can function as an electrode in contact with the adjacent formation. After such an electrode, and a companion one in another borehole, is formed, current can be sent from one electrode through the formation to the other electrode, thus heating the formation. By the use of the electrode of enlarged effective radius, the current density on the electrode is decreased, thus lessening the resistance heating near the electrode. In this manner, the temperature in the vicinity of the enlarged electrode does not become high enough to vaporize the connate water and thus formation heating can continue. By the proper application of electricity between the electrodes, heating of the intervening formation is enhanced, until the temperature between wells is sufficient to make the bitumen mobile. This mobile and liberated bitumen can then be displaced and removed. Mobility of a fluid in a porous media is considered to be proportional to the permeability of the porous medium and inversely proportional to the viscosity of that fluid. Increasing mobility increases the producibility of the given reservoir fluid. Thus, this invention increases the producibility of the hydrocarbon by lowering the viscosity and increasing the mobility through electrical heating.
The mid-point temperature of the formation between two electrode wells will generally be lower than the rest of the heated formation because of low current density at that point. It will also provide a good indicator of how much heating must occur, as it is at this point that the hydrocarbon will be least mobile. The actual mid-point temperature needed will depend on the viscosity-temperature relationship of the hydrocarbon and the nature of the displacing fluid. For Athabasca-type bitumen and using steam as a displacing fluid, this temperature would range from about 130° to about 230° F. (54° C.-110° C.).
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-section view of a borehole at the initiation of the coking process.
FIG. II shows a cross-section view of the borehole at the end of the coke-producing process.
FIG. III shows one embodiment of the invention, a cross-section view of two electrode wells, each having an enlarged effective radius.
FIG. IV-a shows, in cross section, the temperature profile between two electrode wells, at some time during the heating process.
FIG. IV-b shows, in cross section, a plan view of the temperature profile between the same electrode wells as in FIG. 4-a.
FIG. V shows a cross-section view of the temperature profile between two electrode wells after various heating times.
DETAILED DESCRIPTION OF THE INVENTION
Since the invention relates to a process for recovering hydrocarbon values from an underground hydrocarbon-bearing formation and since, more particularly, the process involves coking of the formation, underground formations that can be used in this invention are those exemplified by tar sand, oil shale, and heavy oil deposits, such as those found in Canada and in the Orinoco Basin. These formations contain material that can be transformed into coke or a coke-like material which is carbonaceous in substance and typically has a permeability greater than that of the original formation.
At least two boreholes are used in the process of the invention. The details and the technology of drilling and completing these boreholes is well known in the art and need not be discussed here. FIGS. I, II, and III show the development of the borehole, the placement of a downhole heater, steps in the coking process, and the completion of two electrode wells, each having an electrode of enlarged effective radius. In FIG. I, showing one embodiment of the invention, a tar sand formation, 1, is shown as the underground formation. Borehole 2 is drilled from surface 3, through overburden 4, through the tar sand formation 1, and at least partially into the underlying formation 5. Suitable casing is set in the overburden and cemented 7 in place, leaving the open borehole (uncased) 8 in tar sand formation 1. Then, as is well known in the petroleum industry, a downhole heating device, exemplified by electric heater 9, is placed in the open borehole 8 of tar sand formation 1. Heating device 9 is connected to and suspended from surface 3 by tool cable 10. Heating device 9 is also connected to a source of power (not shown) on surface 3 by an electrical cable 11, comprising power supply wires, temperature control wires, and other necessary electrical fittings .
The heating device used in the process can be any of a variety of such devices. Although an electric heater is shown in FIG. I, a downhole combustion device, such as a propane burner, can be used to heat the surrounding formation. The type of device used is not critical, as long as a sufficient and controlled supply of heat energy can be applied to the formations surrounding the borehole. The heating device is preferably placed in that portion of the formation where the ultimately-formed electrode is desired. Since these high-temperature devices are subject to stress and corrosion, they usually have a limited life and can be discarded or drilled out in subsequent well completion procedures.
The heating device 9 is controlled at a temperature such that thermal cracking occurs in at least a portion of the hydrocarbon-bearing formation surrounding the heating device. As a consequence of this cracking temperature, nearby formation water is vaporized, and products of thermal cracking, such as light ends, are produced. These vapors and gases can be removed, if necessary, through the borehole. Particles of coke, or thermally cracked carbonaceous material, are produced by these high temperatures, typically greater than 500° F. (260° C.). Porosity is developed in the coke, so that the particles allow the inflow of brine. Thus, the coked portion, containing brine, has improved characteristics as an electrode. FIG. II represents the formation at the end of the coke-producing process. The coked zone 12 is substantially cylindrical in shape, generally following the shape of the heating device. This zone can be considered the raw material for, or the precursor of, the effective electrode of enlarged radius for electrically heating a larger portion of the formation, such as between two electrode wells each having such an electrode.
Some of the variables that enter into the process of the invention include the geology of the hydrocarbon-bearing formation, the thickness of the formation, the temperature and time necessary for cracking the hydrocarbon-bearing portion, and the ultimate effective radius to be formed. The radius of the original borehole, and thus the radius of the heating device, can vary from about 2 in. (5 cm) to about 2 feet (61 cm). The radius of the electrode produced as a result of the preceeding steps can vary from about 2 ft. (61 cm) to about 10 ft. (305 cm). The temperature of the heating device should be at least about 800° F. (426° C.), preferably in the range of 1000°-1500° F. (537°-815° C.), and the time necessary to produce an electrode of the desired radius may vary from about 1 to 12 months.
FIG. III shows a cross-section view of two completed wells, wherein sufficient work has been done on the boreholes to carry out a subsequent heating operation. Tubing strings 13, connected to a proper power source (not shown), are inserted into the boreholes and separated by packing devices from casings 6 and the formation 1. Further, electrical insulating sections 15 are used to insulate the lower metallic portion of each borehole fitting from each casing 6.
Sand screens 16 are inserted, by means well-known in the petroleum industry, in the lower portion of each borehole to provide ingress and egress of the liquids and vapors between formation 1 and borehole 2. Insulating oil 17 is added to the upper portion of each borehole to insulate the charged tubing string 13 from casing 6 and surrounding overburden 4. To provide good electrical contact with formation 1 and to act as a coolant, an electrolyte solution 18, such as brine, can be forced down each inner tubing string and return to the surface through each outer tubing string. Some electrolyte flows through the openings of sand screens 16 and enters coked zones 12. Then, during a subsequent process, as electric energy is applied to the lower portion of each borehole, each coked zone 12 becomes an effective electrode of enlarged radius.
Coked zone 12 has a degree of porosity and permeability related to the original formation. Coke particles (or carbonaceous particles) formed by the in-situ heating of the tar sand are distributed in the pores of the formation, and these particles partially fill the pores. Generally, the pores are connected so that there is a continuous path for the conduction of electricity.
After a proper electrode is prepared in each borehole, electric current can be sent from one electrode through the formation to the other electrode, thus heating the formation.
Coked zones 12 are continuously conductive throughout their volume and are closely connected, electrically, with charged tubing strings 13. Thus, using good electrical practices and technology, when the power source (not shown) is activated on the surface, current flows between the electrode wells and, by resistance heating, heats the tar sand formation. Due to the enlarged effective radius of each electrode well, the current density around each electrode is enough to heat the formation by resistance heating but is, or can be controlled to be, low enough so as not to cause evaporation of the connate water and consequent drying of the formation outside the effective radius at the pressure found in the formation. The voltage and current flow are adjusted to effect the desired gradual increase of temperature of the formation between the wells. Broadly, the current may run from a few hundred to 1000 or more amperes at the voltage drop between the electrode wells. And this voltage drop may run from a few hundred volts to as much as 1000 or more volts.
Electrical heating of the formation continues for a length of time which may be between a few months and 4 years, until sufficient mobility is obtained. There are various methods of determining the temperatures at various points in the formation. If the formation is relatively homogeneous, conventional technology relating the energy input and the rate of heat flow through the formation can be used to estimate temperatures at various points in the formation. Another way is to drill test holes at various locations and measure a temperature profile vertically through the formation. Another way is to apply pressure on one of the boreholes and determine the bitumen flow from the other borehole.
FIG. IV-a and IV-b are different views of temperature profiles between two electrode wells after a finite time of heating. FIG. 4-a shows a cross-section view of such a temperature distribution for wells spaced at a particular distance, and the mid-point is about 110° F. (43° C.). FIG. 4-b shows similar information, as a contour or plan view.
FIG. V shows a generalized cross-section view of the temperature distribution between two electrode wells at various times, on a non-specific scale.
When it has been determined that the appropriate minimum temperature has been reached, for example, at the mid-point between the electrode wells, electrical heating is discontinued and preparations are made for the use of an injection fluid.
As is known in enhanced recovery technology, several displacement fluids are available and known. A hydrocarbon solvent, such as a C 6-14 liquid, can be used to displace the oily bitumen from the formation. And it is known to follow such a solvent wash by a second diplacing fluid, such as water or steam. Hot water, by itself or mixed with a material such as a surfactant or an alkaline material such as sodium hydroxide, can be injected into an injection well to displace the mobile bitumen from the formation into a production well. Steam is another displacement fluid and its use is well known in petroleum technology.
The displacing, or drive, fluid is injected into one of the electrode wells that had previously been used for formation heating. All of the proper technological changes are made in the well to convert it to an injection well. Similarly, the other well is converted to a production well. The drive fluid is injected at a pressure below that which is sufficient to lift the overburden, commonly referred to as "fracturing pressure". This particular pressure is determined by the use of conventional petroleum engineering technology and is typically between about 0.5 and 1 lb. per sq. in. (psi) for each foot of overburden. After the fracturing pressure is determined or estimated, the drive fluid is injected and "drives" the mobile bitumen ahead of it. It is desirable that the temperature of the formation, the drive fluid, and the mobile bitumen be kept as high as possible, within the restraints of the fracturing pressure. Heat energy from the drive fluid is exchanged with the bitumen and/or formation, and these exchanges can be calculated or, by using previously-drilled testholes, temperatures in the drive zone are reported, and the progress of the drive can be monitored.
It is possible that, due to various factors, the formation temperature decreases to where the bitumen is not mobile. It is then desirable to stop the injection of the displacement fluid, restore the wells to the heating situation, and heat the formation to a desired temperature. These changes and interruptions are known in petroleum technology and need not be discussed here.
Bitumen is produced from the production well by conventional techniques. Pumping facilities to remove the fluid bitumen can be used, if necessary, but here again, production techniques are well known and need not be discussed.
Injection and production continue until breakthrough takes place. Breakthrough is considered as that point in the operation where injection fluid establishes a flow path completely between the injection and the production wells. After breakthrough, the amount of bitumen carried with the injection fluid decreases, and further production of bitumen from that well becomes less desirable. At this time, the pattern of injection and production wells can be changed.
Although I have shown only two wells used in the heating and production phases, additional wells can be used, following the steps of the process. By proper patterning of wells throughout the formation, injection and production can be shifted between various wells, and production from a large portion of the formation can be established. | In a pair of electrode wells to be developed for injection and production wells for the electrothermal process for recovering heavy hydrocarbons, the electrodes are formed by inserting a heating device in each borehole and heating the surrounding formation to a temperature at which the hydrocarbon-containing material undergoes thermal cracking, resulting in a coke-like residue surrounding the heater. This conductive and permeable material serves as an electrode, for each well, by which the formation is heated. The heavy hydrocarbon material, such as bitumen found in tar sands, becomes mobile and can be recovered. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of application Ser. No. 10/898,618, filed Jul. 22, 2004, pending, which is a divisional of application Ser. No. 10/083,034, filed on Feb. 26, 2002, now U.S. Pat. No. 6,794,749, issued Sep. 21, 2004, which is a continuation of application Ser. No. 09/387,640, filed on Aug. 31, 1999, now U.S. Pat. No. 6,424,033, issued Jul. 23, 2002.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to the packaging of microelectronic devices. More particularly, the present invention relates to heat management for packaged microelectronic devices. Specifically, the present invention relates to the placement of a thermal grease heat transfer medium within an integrated circuit (IC) chip package for heat transfer away from the microchip. The grease acts as a heat sink to assist in the management of heat that is generated by an IC chip in the IC chip package.
[0004] 2. Relevant Technology
[0005] Miniaturization is the process of crowding an increasing number of microelectronic circuits onto a single chip. Additionally, miniaturization involves the reduction of the overall chip package size so as to achieve smaller and more compact devices such as hand-held computers, personal data assistants (PDA), portable telecommunication devices, and the like. Ideally, the chip package size would be no larger than the chip itself. Miniaturization has the counter-productive effect upon chip packaging of an increased heat load upon a smaller chip package. Heat management is, therefore, an important aspect of producing a reliable microelectronic device. A heat sink for a chip package allows for enhanced performance of the microelectronics.
[0006] In the packaging of microelectronic devices, protection of the microelectronic device and its connections to the outside world is critical during packaging and field use. A prior art solution to packaging of microelectronic devices was to cover the integrated circuit chip with a plastic or ceramic material after a manner that both the highly sensitive active surface of the chip as well as the electrical connections were protected. Plastic packaging such as an epoxy material is useful to protect the active surface as well as the electrical connections. Plastic packaging has the disadvantage of being a poor conductor of heat compared to ceramic packaging. Where a plastic material is used, its effect as a poor heat conductor often leads to additional measures that must be taken to extract generated heat from the chip package to allow proper functioning of the microelectronic device. Ceramic packaging has an advantage of a higher thermal conductivity compared to plastic, but it is often costly and bulky, as well as potentially brittle. Where the chip package receives a physical blow, the ceramic package may shatter.
[0007] What is needed in the art is a means of transferring heat away from a microelectronic device that overcomes the heat management problems of the prior art.
SUMMARY OF THE INVENTION
[0008] The present invention relates to an integrated circuit chip package having an IC chip with an active surface, where the active surface has extending therefrom an electrical connector in electrical communication with the IC chip. The IC chip is mounted upon a substrate such as a printed circuit board (PCB). A grease is in contact with the active surface of the IC chip and a container is disposed upon the substrate. The grease is enclosed within the container and the substrate.
[0009] The present invention relates to the use of the grease as a protective substance to protect both the active surface of the IC chip and simultaneously as a heat transfer medium to transfer heat away from the IC chip. The present invention also relates to a method of heat transfer away from an IC chip using grease, a substrate upon which the IC chip is mounted, and a container.
[0010] In one embodiment of the present invention, an IC chip is configured as a board-on-chip (BOC) package and a thermal grease is disposed upon the exposed active surface of the chip, as well as over the electrical connectors such as bond wires or solder balls if present. A protective shell covers the thermal grease to prevent disturbance of the grease during both assembly thereof and during field use. Alternatively, a dam structure may be disposed upon the board and the protective shell to hold the protective shell in place. Additionally, at least one vent hole may be disposed in the protective shell to allow for thermal expansion and contraction of the grease. The BOC configuration lends itself to a stacked BOC package where multiple occurrences of BOC may be enclosed within a single protective shell.
[0011] In another embodiment of the present invention, a chip-on-board (COB) chip package is configured with the grease disposed upon the active surface of the IC chip where the grease also covers the bond wires. The protective shell is disposed upon the grease and is secured against the substrate on the same surface onto which the IC chip is disposed. In a variation of this embodiment, the protective shell is configured to make direct contact with the active surface of the IC chip.
[0012] Another embodiment of the present invention includes an IC chip mounted directly upon a heat sink. A substrate is also mounted directly upon the heat sink, and grease covers both the active surface of the IC chip and the bond wires. Additionally, a protective shell is mounted upon the substrate, where the grease is enclosed by the protective shell and the substrate.
[0013] Another embodiment of the present invention comprises a flip-chip configuration wherein the grease is disposed both upon the active surface of the flip-chip and upon the balls of a flip-chip ball array that provides electrical connections to the flip-chip. A dam structure may be disposed upon both the flip-chip substrate and the flip-chip itself to assist in containing the grease. In a variation of the foregoing involving a flip-chip upon a flexible substrate, a protective shell is disposed upon the flex substrate and grease substantially encompasses the entire flip-chip as well as the flip-chip ball array. In a still further variation, the protective shell is in direct contact with the inactive surface of the flip-chip, the protective shell thereby simultaneously acts as a die attach and heat sink, and the flex substrate with the protective shell provide an enclosure for the grease.
[0014] Another embodiment of the present invention includes flip-chip-on-die (FCOD) wherein the flip-chip is disposed against a COB die. In a first configuration of this embodiment, the flip-chip ball array is in contact with a grease and the bond wires from the die are enclosed in a second protective material that is typically a thermoplastic or thermoset resin.
[0015] An alternative embodiment of the FCOD configuration provides for grease to be in contact with both the flip-chip ball array and the bond wires from the die. A protective shell is disposed upon the substrate supporting the die such that the protective shell and the substrate enclose therein both the flip-chip and the die.
[0016] Another alternative embodiment of the FCOD configuration provides for a two-piece protective shell that may allow the inactive surface of the flip-chip to be exposed. This alternative embodiment provides for the flip-chip ball array and the bond wire to be encompassed by grease while allowing the inactive surface to radiate heat away from the flip-chip.
[0017] These and other features of the present invention will become more fully apparent from the following description and appended claims or may be learned by the practice of the invention as set forth hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order that the manner in which the above-recited and other advantages of the invention are obtained, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not, therefore, to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
[0019] FIG. 1 is an elevational cross-section view of a board-on-chip package according to the present invention;
[0020] FIG. 2 is an elevational cross-section view of a stacked board-on-chip configuration according to the present invention;
[0021] FIG. 3 is an elevational cross-section view of a stacked board-on-chip configuration, wherein the board and chip orientation is vertically inverted in comparison to the configuration depicted in FIG. 2 ;
[0022] FIG. 4 is an elevational cross-section view of a chip-on-board configuration according to the present invention;
[0023] FIG. 5 is an elevational cross-section view of an alternative embodiment of the chip-on-board configuration depicted in FIG. 4 wherein the protective shell acts as a direct-contact heat sink to the active surface of the chip;
[0024] FIG. 6 is an elevational cross-section view of a chip-on-heat-sink configuration according to the present invention;
[0025] FIG. 7 is an elevational cross-section view of a flip-chip-on-flex configuration according to the present invention;
[0026] FIG. 8 is an elevational cross-section view of an alternative embodiment of a flip-chip-on-flex configuration according to the present invention;
[0027] FIG. 9 is an elevational cross-section view of another alternative embodiment of the flip-chip-on-flex configuration;
[0028] FIG. 10 is an elevational cross-section view of a flip-chip-on-die configuration according to the present invention;
[0029] FIG. 11 is an elevational cross-section view of an alternative embodiment of the flip-chip-on-die-configuration; and
[0030] FIG. 12 is an elevational cross-section view of another alternative embodiment of the flip-chip-on-die configuration.
DETAILED DESCRIPTION OF THE INVENTION
[0031] The present invention relates to an IC chip package that overcomes the problems of the prior art. The IC chip package has a heat sink that comprises a grease that aids heat dissipation and that protects the active surface of the IC chip and/or the electrical connectors such as bond wires or solder balls.
[0032] The present invention may include a fine pitch ball array, typically disposed upon a printed circuit board (PCB). The PCB is typically attached to an IC chip. Disposed upon the active surface of the IC chip is the grease. Simultaneously, the grease may also be in direct contact with the electrical connectors such as bond wires or balls in a ball array. A protective shell is placed over the grease.
[0033] Reference will now be made to figures wherein like structures will be provided with like reference designations. It is to be understood that the drawings are diagrammatic and schematic representations of embodiments of the present invention and are not limiting of the present invention nor are they necessarily drawn to scale.
[0034] FIG. 1 is an elevational cross-section view of an IC chip package 10 with a board-on-chip (BOC) configuration. FIG. 1 illustrates an IC chip 12 disposed upon a substrate 14 such as a flexible PCB. The active surface 16 of IC chip 12 is disposed against a first side 50 of substrate 14 . Emerging from the active surface 16 of IC chip 12 , are bond wires 18 that act as electrical connectors between active surface 16 of IC chip 12 and substrate 14 .
[0035] For chip package 10 , in the BOC configuration, a ball array 20 is disposed upon a second side 48 of substrate 14 . Second side 48 is opposite and parallel with first side 50 upon which IC chip 12 is disposed.
[0036] A grease 22 is disposed upon active surface 16 of IC chip 12 as well as in direct contact with bond wires 18 . Grease 22 thus provides a heat sink having a first thermal conductivity that is in direct contact with both active surface 16 and bond wires 18 . Preferably, a protective shell 24 is disposed over grease 22 in order to prevent the disturbance and/or flow of grease 22 during ordinary handling incidental to the assembly of chip package 19 and incidental to ordinary field use. The protective shell 24 is preferably composed of a thin metal or other highly thermally conductive material that allows for good thermal coupling to thermal grease 22 . In some cases, such a protective shell may not be necessary.
[0037] Grease 22 may be any high thermal conductivity grease known in the art. Preferably, grease 22 is a high thermal conductivity grease that will flow at a minimum temperature that is in a range from about 190° C. to about 230° C., and preferably will flow at no less than a temperature of about 220° C. An example of preferred high thermal conductivity greases is GELEASE™ manufactured by Thermoset Plastics, Inc. of Indianapolis, Ind. A preferred class of protective materials is described in “High Thermal Conductivity Greases” by Ron Hunadi and Rich Wells (advanced packaging, Apr. 19, 1999, pp. 28-31), the disclosure of which is incorporated herein by reference.
[0038] The present invention contemplates a dielectric grease that has a thermal conductivity in a range from about 0.5 Watts/m.K to about 5 Watts/m.K, preferably from about 2 Watts/m.K to about 4 Watts/m.K. Additionally, the grease will preferably have a dielectric constant that is in a range from about 1.2 to about 10, preferably from about 4 to about 9.5, and most preferably less than about 6. Because of high temperature operation of chip packages, the dielectric grease will preferably have a melting point that is in a range from about 100° C. to about 230° C., and preferably from about 190° C. to about 220° C. Another property that is preferred for the grease 22 is a minimum weight loss at chip package operating temperatures for the conceivable lifetime of the chip package. Preferably, the grease has a weight loss at a sustained temperature of 100° C. over a period of 30 days of less than about 0.15%. It is preferred that, under these conditions, the grease 22 will have a weight loss over a period of about 20 years of less than about 0.25%.
[0039] Vent holes 26 may be provided in protective shell 24 in order to allow the expansion of grease 22 under high temperature cycling conditions. Vent hole 26 may be a single vent hole or a plurality of vent holes. Vent hole 26 allows for the expansion of an excess amount of grease 22 during such high temperature applications as burn-in testing. The size of vent hole 26 may be such so as to allow for excess grease 22 to exude from within the enclosure formed by protective shell 24 and substrate 14 . Multiple vent holes can also be employed.
[0040] A dam structure 28 may be placed in contact with protective shell 24 and second side 48 of substrate 14 to hold protective shell 24 in place. Where the stickiness and viscosity of grease 22 is sufficient to hold protective shell 24 in place, dam structure 28 may be omitted. Alternatively, protective shell 24 can be directly attached to substrate 14 by use of suitable adhesives.
[0041] Protective shell 24 is preferably made of a metallic or ceramic material that has a thermal conductivity that is greater than the thermal conductivity of grease 22 . Thereby, protective shell 24 acts as a second heat sink that facilitates the transfer of heat through grease 22 away from IC chip 12 . Preferred metals for protective shell 24 include Al, Cu, Au or alloys of such metal, and Ag. Most preferably, protective shell 24 is composed of Cu or an alloy thereof.
[0042] The BOC configuration lends itself well to multiple BOC packages that use grease 22 as a heat transfer medium and as a protective substance. FIG. 2 illustrates a multiple BOC chip package 110 wherein substrate 14 has its own IC chip 12 and ball array 20 along with protective shell 24 that contains grease 22 . Over first side 50 of substrate 14 is disposed a substrate 114 and an enclosed ball array 132 . Substrate 114 supports an IC chip 112 to comprise a second BOC configuration that is stacked upon substrate 14 . FIG. 2 also illustrates a third BOC configuration such that three BOC configurations comprise chip package 110 .
[0043] A second protective shell 34 encloses the major portion of chip package 110 . Disposed in the interstices of chip package 110 is grease 22 . Alternatively, a dam structure 128 may also be provided upon first side 50 of substrate 14 and against second protective shell 34 in order to hold second protective shell 34 against substrate 14 . Although not pictured, one or multiple vent holes may be provided as illustrated in FIG. 1 . The vent holes may be provided both for protective shell 24 and for protective shell 34 .
[0044] Another alternative embodiment of multiple, stacked BOC configurations is illustrated in FIG. 3 as a chip package 210 . The configuration of each BOC substructure is vertically inverted in comparison to the configuration of each BOC substructure depicted in FIG. 2 . The embodiment depicted in FIG. 3 includes substrate 14 and IC chip 12 disposed upon first side 50 of substrate 14 . In this embodiment, ball array 20 is also disposed upon first side 50 . FIG. 3 depicts that each active surface 16 and 216 of IC chips 12 and 212 , and all bond wires 18 and 218 , as well as substrates 214 and connective elements 232 , are enclosed in a single space formed principally by protective shell 224 and substrate 14 . Thereby, two protective shells are not required and chip package 210 is enclosed substantially in a common space with all active surfaces and electrical connectors being in contact with grease 22 contained therein. A vent hole (not pictured) may also be present.
[0045] One of the advantages in relation to heat management that exists in the present invention is the rapid flow of generated heat through grease 22 due to its higher coefficients of thermal conductivity compared to thermoplastics and thermoset resins of the prior art. A particular advantage in the stacked BOC configurations depicted in FIGS. 2 and 3 is that a chip in the stack that generates more heat than others will be cooled by the presence of other chips, particularly through the conductive heat transfer medium provided by grease 22 .
[0046] The presence of grease 22 in every embodiment of the present invention has an advantage over plastics in that the preferred grease has a greater thermal conductivity than the plastics. The flowability of grease permits direct contact with active surfaces of IC chips and electrical connectors, whereas ceramic housings do not permit this type of intimate contact with hot surfaces. Likewise, with the intimate contact there is a continuum of thermal conductivity between the hot surface, the grease, the substrate, and the protective shell.
[0047] In a chip-on-board (COB) configuration of the present invention, FIG. 4 illustrates a chip package 310 that includes an IC chip 312 disposed upon a substrate 314 . IC chip 312 has its active surface 16 and bond wires 318 on a first side 350 of substrate 314 . Opposite and parallel to first side 350 , a ball array 320 is disposed upon a second side 348 of substrate 314 . Grease 22 is enclosed by a combination of a protective shell 324 , first side 350 of substrate 314 , and portions of IC chip 312 . FIG. 4 also illustrates the positioning of an optional vent hole 26 through the wall of protective shell 324 .
[0048] FIG. 5 illustrates an alternative to the embodiment of chip package 310 depicted in FIG. 4 . A chip package 410 illustrated in FIG. 5 depicts a section of a protective shell 424 that makes contact with upper surface 16 of IC chip 312 . In this configuration, direct contact of protective shell 424 with upper surface 16 comprises a die-attach heat sink. Where the thermal conductivity of protective shell 424 is greater than the thermal conductivity of grease 22 and where direct contact by protective shell 424 is made onto IC chip 312 , heat transfer away from IC chip 312 is facilitated to a greater degree than the embodiment depicted in FIG. 4 . It is noted that protective shell 424 can also be attached to chip 312 at active surface 16 through a conductive adhesive or an epoxy such as those used for die-attach applications and are known in the art.
[0049] FIG. 6 is another embodiment of the present invention, wherein a chip package 510 is depicted that includes an IC chip 512 disposed against a heat sink 30 . A substrate 514 of bearing ball array 520 is disposed upon heat sink 30 and active surface 16 is in electrical connection with a first side 550 of substrate 514 through bond wires 518 . According to the present invention, grease 22 is in contact with active surface 16 of IC chip 512 and with bond wires 518 . Further, grease 22 is enclosed by a protective shell 524 that also is disposed upon substrate 514 . According to this embodiment of the present invention, chip package 510 allows for a significant amount of heat transfer into heat sink 30 , while also allowing a significant amount of beat transfer from active surface 16 and bond wires 518 into grease 22 . As in all other embodiments set forth in the present invention, a vent hole is optional. Further, a dam structure is also optional.
[0050] FIG. 7 illustrates another embodiment of the present invention wherein a chip package 610 comprises flip-chip-on-flex (FCOF) technology. A flip-chip 612 has a ball array 620 disposed upon active surface 16 thereof. Ball array 620 is disposed upon a substrate 614 that is typically a flexible PCB. Non-flexible substrates can also be employed. Grease 22 is disposed both against active surface 16 and in contact with each individual ball of ball array 620 . Typically, dam structure 28 is an epoxy material or glob top material. Grease 22 is, therefore, containerized by the combination of active surface 16 of flip-chip 612 , dam structure 28 that acts as a container, and the first surface 650 of substrate 614 . As is typical with FCOF, a second ball array 36 is disposed upon the second side 648 of substrate 614 . It is notable that FIG. 7 discloses no vent hole to allow for the expansion and contraction of grease 22 . A vent hole, however, may be formed by placing a hole in substrate 614 at a location that opens up to first side 650 without any obstruction from an electrical connection disposed upon first side 650 .
[0051] FIG. 8 is another embodiment of FCOF technology according to the present invention. An FCOF package 710 is depicted as comprising flip-chip 612 with ball array 620 disposed upon active surface 16 thereof. In place of dam structure 28 to act as the container, a protective shell 624 is displayed as being disposed upon substrate 614 . Protective shell 624 is used for enclosing grease 22 along with a combination of protective shell 624 , and first side 650 of substrate 614 . Grease 22 thus substantially contacts all exposed surfaces of flip-chip 612 and also contacts all exposed electrical connectors that comprise ball array 620 .
[0052] A particular advantage of the embodiment depicted in FIG. 8 is that it allows for a shared heat load by all portions of flip-chip 612 through the medium of grease 22 as a heat transfer material. Where one portion of flip-chip 612 may be more microelectronically active than any other portion, grease 22 will heat in that region and allow for heat to be drawn away therefrom to other portions of flip-chip 612 that are not as active.
[0053] Another embodiment of the FCOF configuration is depicted in FIG. 9 , wherein a chip package 810 includes flip-chip 612 and ball array 620 disposed upon substrate 614 at its first side 650 . Additionally, a protective shell 824 is disposed upon substrate 614 but it also makes direct contact with flip-chip 612 at its inactive surface 52 . Thus, protective shell 824 acts as a die-attach for flip-chip 612 . Simultaneously, protective shell 824 is both a heat sink and a container for holding grease 22 against active surface 16 of flip-chip 612 and against the electrical connectors that make up ball array 620 .
[0054] Another application of the present invention is directed toward flip-chip-on-die (FCOD) technology as depicted in FIG. 10 . An FCOD package 910 includes an IC chip 912 that acts as the die in the FCOD configuration. IC chip 912 , referred to hereafter as die 912 , is disposed upon a substrate 914 and also has bond wires 318 that make electrical connection between active surface 16 and first side 950 of substrate 914 . A ball array 920 acts as the electrical connector between a flip-chip 40 and die 912 . Grease 22 is depicted as filling the interstices between individual balls of ball array 920 , between flip-chip 40 and die 912 . FIG. 10 also illustrates the presence of a second protective material 38 that is preferably a thermoplastic or thermoset resin. Second protective material 38 acts as both a container that is disposed upon substrate 914 and as a protective cover for bond wires 318 .
[0055] FIG. 11 is another embodiment of an FCOD configuration, wherein a chip package 1010 includes die 912 with a ball array 920 disposed upon active surface 16 of die 912 . A flip-chip 40 is disposed upon ball array 920 . A protective shell 924 is disposed upon substrate 914 . Contained within protective shell 924 and substrate 914 is grease 22 . FIG. 11 illustrates direct contact of protective shell 924 against flip-chip 40 . Accordingly, protective shell 924 acts as a conductive heat sink for flip-chip 40 . Where die 912 produces a major portion of heat during ordinary use of chip package 1010 , flip-chip 40 itself acts as a heat sink for die 912 in addition to protective shell 924 as protective shell 924 makes direct contact with flip-chip 40 . Grease 22 operates to moderate extreme temperature fluctuation due to its ability to conduct heat more efficiently than the thermoplastic and thermoset materials of the prior art.
[0056] Another embodiment of FCOD technology is depicted in FIG. 12 , wherein a chip package 1110 is configured with both die 912 and flip-chip 40 disposed with ball array 920 therebetween. A protective shell 1124 is depicted as being disposed upon substrate 914 . Optionally, dam structure 28 assists in securing protective shell 1124 to substrate 914 . A second dam structure 44 is also optionally present in order to assist in securing protective shell 1124 to flip-chip 40 . In the embodiment depicted in FIG. 12 , heat conduction that may occur principally in die 912 is dissipated by the presence of flip-chip 40 as a heat sink therefor.
[0057] The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrated and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. | The present invention relates to enhanced protection of the active surface and the bond wires or ball array of a microelectronic device, and to thermal management of the microelectronic device as it is packaged with a printed circuit board (PCB) or other substrate. The enhanced protection and thermal management are accomplished with a high-temperature thermal grease that is glob topped or encapsulated over the bond wires or ball array, and the active surface of the microelectronic device. The high-temperature thermal grease exchanges heat, particularly by conduction, away from the active surface of the microelectronic device as well as away from the bond wires. | 7 |
FIELD OF THE INVENTION
This invention relates generally to apparatuses for capturing and thereby preventing the disassembly of a down-hole mud motor as a result of counter rotation of the power section relative to a portion of the motor housing.
GENERAL BACKGROUND
Down-hole tools such as mud motors that are hydrostatically driven and therefore rotatable relative to the drill string are used to drive the drill bit. Rather than having a larger surface motor rotate the entire drill string, a down-hole mud motor rotates the drill bit. This arrangement is especially useful in horizontal bores.
Generally, such motors utilize some type of bearing so that the down-hole mud motor is allowed to rotate relative to the drill string. These down-hole motors are subjected to a very hostile environment such as exposure to high heat, vibration, and high velocity solids. Accordingly, it is not uncommon for the motor bearings to fail. Bearing failure causes the motor to stall. However, since the operators of the drilling operation are ordinarily unaware of such failure and thus continue driving the down-hole motor, the continued rotational force applied to the drill bit by the down-hole mud motor power section has a tendency to rotate the portion of the motor housing located below the power section. Rotation of these sections of the down-hole motor housing eventually results in at least one of the sections and the drill bit becoming separated from the remainder of the down-hole mud motor housing and possibly being lost in the well bore. If the motor housing and bit are lost in the well bore, generally it is time consuming and expensive to perform fishing operations in an attempt to retrieve the lost components. When these relatively expensive components cannot be retrieved, they generally continue to impede further drilling operations.
Various methods have been employed within the art to overcome the above stated problem. For example Falgout and Beasley, in U.S. Pat. Nos. 6,540,020 and 5,165,492 respectively, disclose a valve having means for biasing the valve against rotation of the housing in a manner that allows the flow of fluid to the motor to be cut off if the fluid motor housings and bit separate. It is suggested that this restriction in fluid flow will alert the operators on the surface that a problem exists and thus initiate a removal of the mud motor procedure for inspection. A sudden disruption of flow in the form of a blockage at high pressure in excess of 6000 psi certainly tends to get someone's attention when the surface pump is destroyed as a result. In addition, once the fluid to the down-hole motor is shut off, it becomes very difficult to withdraw the drill string. In such cases, extraordinary measures must be taken to free the bit manually and retrieve the drill string.
The present invention is directed to overcoming or minimizing one or more of the problems discussed above.
SUMMARY OF THE INVENTION
A retaining apparatus is provided for preventing the separation and loss of a down-hole drive motor and associated drill bit from the drill string due to gyroscopic precession of the motor housing resulting from counter torque produced by the drill bit. The retaining apparatus includes; a collet, an expander pin with interchangeable nozzles, and a fluid bypass flange.
BRIEF DESCRIPTION OF THE DRAWINGS
For a further understanding of the nature and objects of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings, in which, like parts are given like reference numerals, and wherein:
FIG. 1 is a partial view of a down-hole drill string;
FIG. 2 is a cross-section view of retainer assembly used to capture the drill bit and motor assembly shown in FIG. 1 in the stand-by position;
FIG. 3A is a cross-section view of the retainer assembly in the capture position;
FIG. 3B is a longitudinal continuation of the cross-section view shown in FIG. 3A showing the drive motor stator separation; and
FIG. 4 is an isometric exploded view of the retainer assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As may be seen in the stylized view of a drill string 10 , shown in FIG. 1 , the drill string 10 is composed of a series of tubular members 12 , 13 , 14 , 15 , 16 threaded together to form a hollow-core cylinder. Preferably, the tubular members 12 , 13 , 14 , 15 , 16 are joined together by threaded connections that employ right hand threads. A drill bit 20 is depicted rotatably connected at the bottom of the drill string 10 via a down-hole motor assembly 25 located within the lowermost tubular members 15 , 16 . The down-hole motor 25 includes a housing 23 , a power section 24 , and a bearing section 22 .
To effect rotation of the drill bit 20 relative to the drill string 10 , the conventional down-hole motor 25 located within the core of the drill string 10 is operated by pumping drilling fluid through the core of the drill string 10 and the motor 25 , imparting a rotational movement to the drill bit 20 . Generally the drill bit 20 is rotated in a clockwise direction, as viewed from a vantage point above the drill string 10 , as indicated by an arrow 27 adjacent the bit 20 .
Since the drill bit 20 is rotatable relative to the drill string 10 , the bearing section 22 is provided to reduce frictional wear between the two members and generally includes at least two sets of bearings 26 , 28 spaced longitudinally apart to reduce rotational wobble of the drill bit 20 relative to the drill string 10 as it rotates.
In some cases the bearings 26 , 28 cease to operate properly so that the drill bit 20 does not freely rotate relative to the drill string 10 , in which case the clockwise rotational force applied to the drill bit 20 is also applied to the drill string 10 through the bearings 26 , 28 and, in particular, to the lower tubular member 16 of the housing 23 . Since the lower tubular member 16 is attached to the upper tubular member 15 via right hand threads 40 , the clockwise rotation of the lower tubular member 16 tends to unscrew the lower tubular member 16 from the upper tubular member 15 until they separate as shown in FIG. 3B .
Referring to FIG. 2 , a longitudinal cross-sectional view of a portion of the drill string 10 that includes the joint formed by the coupling of tubular members 14 , 15 is shown. It should be noted that the tubular member 14 is a typical sub-section of the tubular drill string 10 and requires no special machining and serves only to house the upper portion of the retainer assembly 30 . The retainer assembly 30 includes a tubular central pin member 32 , a nozzle member 33 , a collet member 34 , and a flange member 36 as shown in FIG. 4 .
As seen in FIG. 4 , the collet 34 may be defined as an elongated tubular with a shoulder or collar 44 at one end and an upset 35 at the other. The collet 34 also has a plurality of radially spaced slits 45 extending from the collar 44 to the upset end 35 , thereby allowing the collet 34 to be compressed for insertion into the motor rotor 42 .
As seen in FIG. 2 , a shoulder 38 is formed at the base of the internal threads 40 located at the upper end of the sub-section 15 for seating the flange member 36 . The central pin 32 and collet member 34 pass through the flange member 36 and are connected to the motor rotor member 42 . Unlike conventional retaining members the instant retainer assembly 30 is not threadably connected to the rotor 42 . Instead the end of the motor rotor 42 is counter-bored 37 to accept one end of the pin 32 and the upset portion 35 of the expandable collet 34 . Compression of the collet member 34 is required for insertion into the counter-bore 37 in the rotor 42 where the upset portion 35 of the collet member 34 is allowed to expand into a cooperative cavity 39 in the rotor 42 , counter bore 37 . Insertion of the hollow pin 32 through the center of the collet 34 maintains the upset 35 in the rotor cavity 39 . The hollow or tubular pin 32 is threadably retained within the collet 34 , as indicated in FIG. 4 , by engagement of the external threads 50 on the pin 32 with the internal threads 52 within the collet 34 . Rotation and vibration of the rotor 42 is therefore allowed without the possibility of retainer separation.
As seen in FIG. 3A , if separation of the motor drive sub-section 15 occurs relative to the sub section 16 as seen in FIG. 3B , the collar portion 44 of the collet 34 comes into contact with the flange member 36 , thus preventing loss of the drive motor assembly 22 and bit 20 .
It has been found that it is not only unnecessary to notify topside personnel of an uncoupling situation down-hole, it may also in fact be detrimental to the pumping operation. Therefore, fluid flowing through the drill string 10 is allowed to flow freely through a plurality of orifices 46 located in the flange member 36 without interruption should an uncoupling situation occur. Since a pressure loss occurs as a result of the decoupling, sufficient warning is given.
It should also be noted that the tool joint located between sub-sections 14 and 15 is not affected by counter rotation and therefore only serves to lock the flange 36 in position relative to the joint.
Because many varying and different embodiments may be made within the scope of the inventive concept herein taught, and because many modifications may be made in the embodiments herein detailed in accordance with the descriptive requirement of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in any limiting sense. | A retaining apparatus is provided for preventing the separation and loss of a down-hole drive motor and associated drill bit from the drill string due to gyroscopic precession of the motor housing resulting from counter torque produced by the drill bit. The retaining apparatus includes a collet, an expander with interchangeable nozzles and a fluid bypass flange. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The application is a U.S. National Stage Application of International Application of PCT/EP2008/064376 filed Oct. 23, 2008, which claims the benefit of German Patent Application No. 10 2007 050 637.8 filed Oct. 23, 2007, the disclosures of which are herein incorporated by reference in their entireties.
FIELD OF THE DISCLOSURE
The invention relates to a method for producing thermoformed articles such as food packagings or parts thereof, with a mechanical weakening between mutually adjoining functional areas which articles can be separated at least partly from one another at the mechanical weakening, when used by a user, in a thermoforming die with an upper die and a lower die, which are movable against each other (direction of movement of the die), which method comprises the steps of:
feeding a plastic sheet between the upper die and the lower die, and thermoforming the fed plastic sheet by closing the upper die and the lower die in the direction of movement of the die,
the mechanical weakening being introduced during the period of time during which the material to be formed is located in the thermoforming die.
Furthermore the invention relates to a die for producing thermoformed articles such as food packagings or parts thereof, which comprises:
an upper die, a lower die and at least one perforating or stamping element with a perforating or stamping cutting edge, which is disposed in the upper die or the lower die, the upper die and the lower die being movable against each other (direction of movement of the die).
BACKGROUND OF THE DISCLOSURE
Thermoformed articles as well as methods and dies for the production thereof are known from the prior art. These articles may e.g. be food packaging or parts thereof. The packagings may contain several chambers, each being filled with a foodstuff. A mechanical weakening, e.g. in the form of a stamping or perforation, may be provided between the individual chambers, along which the chambers can be separated from each other. Such food packagings serve for subdividing larger containers into subcontainers, which can be successively consumed by a consumer. Furthermore, the chambers may be filled with different products which, after opening, are mixed or at least jointly consumed. Finally, packagings are available, in which the different contents of the compartments are to experience a different heating, which is made possible by a separation of the subcontainers.
The packagings are produced by producing the spatial structure of the articles to be produced with the corresponding number of chambers by means of thermoforming from a plane sheet material with connection areas being respectively located between them and the mechanical weakening is introduced into the respectively plane connection area between two chambers. The packagings are closed with a sealed or welded sheet which is also mechanically weakened. Here, the connection area always extends in a single plane that is in parallel to the plane of the sheet.
In food packagings in which the mechanical weakening has the plane extension described above, it is introduced into the material by means of a perforating or stamping die, while it is located in the thermoforming die. However, if the extension of the mechanical weakening deviates from the plane extension described above and extends in a plane that is inclined or vertical to it or if the extension of the mechanical weakening even extends in three direction in space, this method is not suitable for the production of such articles. Such packagings are produced in accordance with the prior art by thermoforming them first of all without a weakening and the mechanical weakening is subsequently introduced by means of a laser beam or water jet. Irrespective of the fact whether the article to be produced or the positioning of the beam or jet is moved, it is necessary to constantly readjust the focusing the beam or jet. It is only possible in this fashion to achieve equal perforation results in all areas of the weakening which is not plane.
The aforementioned method and a container produced by means of this method as a food packaging are e.g. known from WO 2005/090199 A2. This publication discloses a food packaging in the form of sterilizable containers which are connected with each other in a separable fashion. The containers are formed from a plastic material and have a flange (connection area) between each other, which is mechanically weakened and at which the containers can be separated from each other by means of breaking.
The containers themselves are formed from a plastic sheet which is brought into the desired shape by means of a thermoforming process. The mechanical weakening is introduced into the flange area by means of a laser beam or a water jet after the curing of the containers. Here, it is possible by means of a corresponding positioning of the beam or jet and a corresponding focusing to introduce the weakening which extends in an uneven fashion in the direction of processing into the flange area. Although food packagings with a mechanical weakening of good quality can be produced with this method, the processing with a laser beam or water jet represents an additional process step which is connected with a quite essential expenditure and additional costs.
In view of the described prior art the object of the invention is providing a method and a die for the production of thermoformed articles such as food packagings or parts thereof, by which the articles preferably can be produced in a single processing station, wherein, cost-intensive and expensive processes such as laser beam or water jet cutting do not have to be used and by which stabilized, clampable or locking lid elements can also be produced.
SUMMARY OF THE DISCLOSURE
This object is attained by a method of the type mentioned at the beginning, which is characterized in that the weakening is formed in areas of the article, which are staggered with respect to each other in the direction of movement of the die and extend vertically to it, and/or is formed at least partly in at least one plane extending in the direction of movement of the die at an angle α other than 90° to the direction of movement of the die within the article.
Regarding the device, the object is attained by a die of the type mentioned at the beginning, which is characterized in that the perforating or stamping cutting edge comprises at least two first sections which are staggered in the direction of movement of the die relative to each other and which extend vertically to it and each of the two first sections is suited for forming a section of the mechanical weakening and/or the perforating or stamping cutting edge comprises at least a second section which is suited for forming a section of the mechanical weakening and is formed at an angle α other than 90° to the direction of movement of the die.
The die is described by means of a direction of movement of the die which, as a rule, is vertical and a direction or plane extending vertically to it, in which the sheet that is processed by the die normally comes to rest. Thermoformed lids or lower parts (dishes), in particular those with several compartments, are made from this sheet. This working plane which must be described as the sheet plane is vertically to the direction of movement of the die. There are at least two sections extending in the sheet plane and being mutually staggered in the direction of movement of the die, preferably in parallel.
Due to this, a third dimension is circumscribed, into which the mechanical weakening line caused by the perforating or stamping cutting edge is introduced, which has the corresponding sections on the die side.
At least two sections of a mechanical weakening are introduced into the sheet by means of the at least two first sections of the perforating or stamping cutting edge, these sections being preferably formed in a linear fashion.
The line does not exclusively extend horizontally and not exclusively vertically, but may be inclined with respect to the direction of movement of the die, a preferred area of inclination being oriented at an angle of from 35° to 65° with respect to the direction of movement of the die. This is expressed by the circumscription of the term of an angle which is formed unequal to 90° with respect to the direction of movement of the die so that the at least one second section of the perforating or stamping cutting edge has an angle which deviates from an area vertically to the direction of movement. Said angle is defined between the extension of the first or second section of the perforating or stamping cutting edge and the axis of the direction of the movement of the die. A section of the stamping cutting edge which is in the sheet plane as the working plane has an angle of 90° and a section which is vertically to the sheet plane as the working plane has an angle of 0°.
Using the method according to the invention it is possible for the first time to form thermoformed articles with a weakening that is almost arbitrarily formed without the use of additional processes such as laser beam or water jet cutting during the thermoforming. Devices necessary for producing the respective articles are advantageously restricted to those for thermoforming, for which reason production cost can be reduced and manufacturing sequences can be simplified. Customary thermoforming machines or aggregates can be used for implementing the process, a die according to the invention being installed and no cost-intensive extensions such as e.g. an additional laser station being required.
Packagings can be produced in an especially simple and inexpensive manner by means of the process according to the invention, which e.g. comply with high demands on stability. It is possible here to provide stiffenings in the form of stampings, elevations or bends in the connection area of the packaging without its separability being detrimentally influenced by this.
Furthermore, the closing of separable packagings is no longer restricted to the use of sheets that are glued on or welded on. For this purpose, locking or clampable lid elements being especially adapted to the shape and the stability of the cup elements of the packaging may rather be produced using the method according to the invention and/or the dies according to the invention, which are also stabilized by means of a corresponding three-dimensional shaping.
A partial detaching of the material along an arbitrarily shaped line is to be understood by a perforation in the sense of the present invention, any number of connecting webs of to any shape remaining. An area-wise reduction of the cross-section of material is to be understood by a stamping in the sense of the present invention without a complete detachment of the material taking place.
According to the method of the claimed invention the thermoformed articles may either be perforated or stamped. However, it is also possible that both a perforation and a stamping are introduced into the material of the articles which results in that the material is in places completely separated and the remaining webs have a smaller cross-section of material than the remaining area of the material due to the stamping. For reasons of a simple formulation and the better understanding the term of the “mechanical weakening” is used in the subsequent description of the invention, which is to be understood in accordance with the aforementioned explanations and is to cover all these variants.
Any forms of the mechanical weakening can be basically produced. It serves in general for forming a parting line between several functional areas, along which the functional areas can at least partly be separated from each other if the article is utilized by a user. The functional areas may e.g. be containers of a container package, which can be completely separated from each other along the mechanical weakening so that the contents of the individual containers can be used separately in each case. The mechanical weakening can be introduced both into a container and into an appurtenant lid.
As is generally known, its function is furthermore not restricted to separating subcontainers from an entire container, optional functional units can rather be separated from each other by means of the weakening. Thus, it is possible to form prefabricated opening areas in a lid e.g. in the form of openings for a drinking straw or reclosable pouring openings. In the case of a perforation such an opening can be formed in a medium-tight fashion by using an additional sealing sheet. The use of an additional sealing sheet is not required in the case of a stamping.
The weakening is introduced into the articles by using one or several perforating or stamping elements shaped in accordance with the shape of the weakening to be produced. It and/or they form(s) the perforating or stamping cutting edges e.g. in accordance with the blade of a knife which introduces the desired weakening into the material of the article to be produced (in the following referred to as perforating elements and/or perforating cutting edges).
In order to form the desired shape of the perforating cutting edge, one or several perforating elements may be used. In the case of a perforating element its perforating surface copies the shape of the thermoformed article along the course of the mechanical weakening. In the case of several perforating elements each perforating element forms a section of the perforation. The introduction of the perforation is brought about by feeding the perforating element relative to the material located in the die. In the case of several perforating elements this feeding can take place at the same time or in a staggered relationship in terms of time and from one direction or from several directions.
The introduction of the weakening takes place during the period of time, during which the material to be reshaped is located in the thermoforming die. According to a special embodiment of the invention the weakening is formed prior to the “actual reshaping” of the plastic sheet. The advantage of this is that a die with a biased perforating element can be used, which, upon a closing of the thermoforming die, leads the upper die or the lower die. Thus, no separate control is required for the perforating element. The dimension of the stamping can be determined by the magnitude of the lead or the bias of the perforating element and the time of action. The bias of the perforating element can be achieved by means of known systems such as e.g. springs, elastomer elements, hydraulics or pneumatics. Furthermore, a separate drive may be provided for a perforating element. The drive can be implemented by means of known processes in a pneumatic, cam control, hydraulic or motor-driven fashion. It is anyway also possible to implement the perforation after the actual shaping of the plastic material, but still in the thermoforming die.
It may be sensible in the case of especially difficult geometries of the thermoformed article to be produced, to at first only form one part of the weakening and, subsequently, further partial areas of the weakening. A first part of the weakening can e.g. be first formed in a first plane and further parts of the weakening can be subesequently formed in planes which are formed obliquely or in parallel to the first plane. Thus, very complex geometries of thermoformed articles can be produced which are only restricted by the stipulations of tooling.
In the die according to the invention the perforating element cooperates with a counter support. This counter support may be designed as a part of the upper die part and/or the lower die part or it may be separately provided. It is adapted to the geometry of the article to be produced and that of the perforating element. It may be necessary in the case of complex geometries of the perforation element and of the counter support, to have to compensate for deviations due to manufacturing inaccuracies, thermal, elastic or plastic elongations, inaccuracies of the machine or inhomogeneities of the material. Consequently, it is suggested in accordance with a further embodiment of the invention that the perforating element and/or the counter support comprise(s) a compensating structure, which allows for compensating elastic deformations of these elements. The compensating structure may e.g. be realized by elastomer elements, spring elements and machining allowance/undersize or gaps vertically to the direction of compensation. They may be provided in the perforation element, in the counter support or in both.
Furthermore, it is suggested with the invention that the die comprises structures for receiving the material displaced by the perforation or stamping so that the material displaced by the perforation or stamping flows into these structures during or after the perforation process. In an especially advantageous fashion the structures are preferably shaped in the form of recesses such as receiving grooves on both sides along the mechanical weakening. Due to this, the material volume displaced by the perforation can flow into the receiving structures on both sides in accordance with its natural flow behavior and does not result in thickened areas of material laterally next to the mechanical weakening. Such thickened areas of material could detrimentally influence the subsequent thermoforming process, since they would have to be eliminated during the thermoforming process. If this fails, the quality of the produced articles is inferior, since the blank holder cannot form the sealing surface all over. Furthermore, a jamming of the die halves would result, which would result in a corresponding additional load of both the die and the entire machine. During the elimination of the material thickening built up due to the perforation process an increased die wear would result, due to which its service life would be reduced in a detrimental manner. A sheet could only be sealed onto the uneven surface with a limited suitability.
In accordance with a further proposal the perforating or stamping elements can be positioned independently of one another in the case of several perforating or stamping elements. A positionability of the perforating or stamping elements is in particular provided in different space directions to each other. Due to this, the possibility of providing mechanical weakenings, e.g. in undercut areas, is created. Due to an independent drivability of the perforating or stamping elements the process according to the invention can be used for producing the most different thermoformed articles.
The mechanical weakening can be introduced by means of a shear cut or butt cut (knife cut) in the article. It is possible due to the use of a shear cut to in particular provide marginal areas of the article with a shear cut, which facilitates a manual separation of the functional areas of the article by the user.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the invention can be seen by means of the Figs. from the following description of especially preferred embodiments.
FIG. 1 : shows a sectional representation of a thermoforming die with an integrated perforating device for a cup element;
FIG. 2 : shows a sectional representation of a thermoforming die with integrated perforating device for a lid element;
FIG. 3 : shows a sectional representation of the thermoforming die of FIG. 2 along the line III/III;
FIG. 4 : shows a schematic representation and an enlargement of a perforating element that can be used in the thermoforming die of FIGS. 2 and 3 ;
FIG. 5 : shows a schematic representation and variations of a counter support for the perforating element according to FIG. 4 ;
FIG. 6 : shows various embodiments of a perforating element;
FIG. 7 : shows an enlarged view of the perforating element and its counter support of the die of FIGS. 1 and 8 ;
FIG. 8 : shows a sectional representation of the thermoforming die of FIG. 1 ;
FIG. 9 : shows a schematic perspective view of a lid element produced with the die of FIGS. 2 and 3 ; and
FIG. 10 : shows a schematic perspective view of a cup element produced with the die of FIGS. 1 and 8 .
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
Two embodiments of the die according to the invention for producing thermoformed articles are represented by way of example in FIGS. 1 , 2 , 3 and 8 . Using the process according to the invention the components shown in FIGS. 9 and 10 —cup element 38 and lid element 39 —of a food packaging can be produced with these dies from a plastic sheet introduced into the die. The shown dies have in each case a lower die with a carrier 1 of the lower die and an upper die with a carrier 2 of the upper die.
The thermoforming die shown in FIGS. 1 and 8 for producing thermoformed cup elements 38 comprises a blank holder 3 disposed in the carrier 2 of the upper die. Two cogging punches 6 a,b are guided in the carrier 2 of the upper die and in the blank holder 3 by means of rams 41 a,b with the intermediate positioning of corresponding linear guides 42 . The cogging punches 6 a,b are disposed in correspondingly shaped recesses 43 of the blank holder 3 .
A perforating element 5 is disposed in a linearly displaceable fashion in the direction of the lower die in a recess 44 of the blank holder 3 , which, here, is linearly disposed. It is biased in the recess 44 with respect to the blank holder 3 by means of a spring 4 or a spring assembly 4 .
The unit of blank holder 3 , cogging punch 6 a,b and perforating element 5 is received in the carrier 2 of the upper die in a linearly displaceable fashion with respect to the carrier 2 of the upper die in the direction of the lower die. A cutting die 7 is disposed on the side of the carrier 2 of the upper die, which points to the lower die, by means of fastening agents (not shown). It cooperates with a blanking punch 8 disposed on the carrier 1 of the lower die and serves for punching the outer edge of the cup element 38 produced by means of the represented die from the plastic sheet.
Molding sleeves 9 a,b are disposed in two recesses provided in the blanking punch 8 of the lower die. A counter support 11 is disposed in the area opposite to the perforating element 5 between the molding sleeves 9 a,b and the blanking punch 8 , which cooperates with the perforating element 5 in a fashion described below. The molding sleeves 9 a,b have in each case a recess 53 in which a ejector 10 a,b is disposed, which forms at the same time the mold bottom. The ejectors 10 a,b are linearly displaceable in the direction of the upper die with respect to the molding sleeves 9 a ,b, the blanking punch 8 and the carrier 1 of the lower die.
The structure formed of parts of the inner contour of the molding sleeve 9 a,b and the surface of the ejector 10 a ,b, which points in the direction of the upper die, forms a mold according to which the outer side of the cup element to be produced is contoured.
The operation of the thermoforming die shown in FIG. 1 will be explained in the following.
Lower die and upper die are open at the beginning of the working cycle. The material for the cups to be produced is introduced as a plastic sheet into the gap 45 formed between the lower die and the upper die, the die being further opened with respect to the represented position. The material was already heated to a suitable processing temperature in a heating station connected in series with the thermoforming die. After the positioning of the material the upper die advances in the direction of the lower die. The feed of the entire upper die stops, only a further feed of blank holder 3 , cogging punch 6 a,b and perforating element 5 takes place. Due to the bias achieved by means of the spring assembly 4 the perforating element 5 leads the blank holder 3 and the cutting die 7 . The perforating element 5 is the first to contact the plastic sheet present in the gap 45 . It introduces a perforation and/or stamping into the plastic sheet in accordance with its structure and its spring bias.
Shortly after the placing of the perforating agent 5 and its at least partial penetration into the plastic sheet the blank holder 3 is placed onto the sheet present in the gap 45 and fixes it relative to the thermoforming die. The surfaces of the blank holder 3 , which point in the direction of the lower die form the structure forming the subsequent upper side of the cup edge. The material displaced by the perforating element 5 flows into the grooves 56 which are only outlined in FIG. 1 and clearly recognizable in the enlargement of FIG. 7 and formed laterally of the perforating element 5 in the counter support 11 . Due to this, the thickness of the material of the plastic sheet between the blank holder 3 and counter support 11 in the subsequent connecting web area 46 of the cup element 38 to be produced is not changed in such a way that a premature placing of the blank holder 3 with a resultant increased pressing of the surface will take place.
After the placing of the blank holder 3 a feed of the cogging punches 6 a,b in the direction of the lower die takes place. The cogging punches 6 a,b draw the material of the sheet present in the gap 45 into the hollow space formed by the molding sleeve 9 a,b, and the ejector 10 a ,b. Due to the generation of a molding pressure in the area between the material and the inner space 43 between the blank holder 3 and the cogging punches 6 a,b plastic material rests against the molding contour. Due to a further feed of the carrier 2 of the upper die in the direction of the lower die an interaction between the cutting die 7 and the blank holder 3 . The inner contour of the cutting die 7 corresponds to the outer contour of the blanking punch 8 . Due to the feed, the cutting die 7 with this inner contour pushes across the outer contour of the blanking punch 8 , due to which a stamping out of the material forming the cup element 38 takes place. After a suitable cooling—the lower die may be designed in a cooled fashion—the entire upper die is lifted off from the lower die. Due to a feed of the ejectors 10 a,b in the direction of the completely lifted upper die, the now fully molded cup element 38 is ejected from the lower die and removed from the thermoforming die. The entire cycle described above is repeated for the production of a further cup element 38 .
The thermoforming die represented in FIGS. 2 and 3 for producing a lid element 39 for the cup element produced by means of the device according to FIGS. 1 and 8 functions in a similar fashion. The upper die has an upper die carrier 13 . A cutting knife 15 is disposed on the same. The cutting knife 15 has a circumferential cutting edge 47 . The side of the cutting knife 15 , which points in the direction of the lower die, is designed in a contoured fashion in the area located within the circumferential cutting edge 47 in accordance with the upper side of the lid element 39 to be produced.
The cutting knife 15 has a recess 48 , within which the perforating element 5 is disposed in a holder 49 . The holder 49 and the perforating element 5 are disposed in the upper die carrier 13 by means of two spring assemblies 4 in a biased fashion in such a way that a relative displacement can take place in the longitudinal direction of the oblong holes 50 which can be recognized in FIG. 3 . Two lateral perforating elements 51 are disposed at the side of the perforating element 5 in FIG. 3 . These are fixed relative to the upper die carrier 13 so that the perforating element 5 can also be displaced relative to the lateral perforating elements 51 in the direction described above.
A counter support 11 is disposed in the area between the two molding rings 17 in the lower die opposite to the perforating element 5 . It cooperates with the perforating element 5 and, if necessary, lateral perforating elements 51 upon the introduction of the mechanical weakening in the lid element 39 .
A clamping frame (not shown) is also disposed on the upper die carrier 13 , which fixes the sheet-shaped starting material in the thermoforming die by means of a counterpunching plate (also not shown). In addition to this function as a clamping tool, the counterpunching plate has the further function of acting as a counterelement to the circumferential cutting edge 47 of the cutting knife 15 in order to make a punching out of the lid element 39 formed between the upper die and the lower die from the sheet web material possible. The counterpunching plate is disposed on the lower die carrier 12 .
Two molding rings 17 are so to speak disposed on the carrier 1 of the lower die which mold parts of the subsequent inner contour of the lid element 39 to be produced. They have in each case a recess within which a mold bottom 18 a,b is disposed. The mold bottoms 18 a,b have the function of molding parts of the inner area of the lid element 39 and, after the implemented molding, of ejecting the produced lid element 39 from the lower die—similar to the ejectors 10 a,b in the thermoforming die explained above in connection with FIG. 1 .
The production of the lid element 39 is implemented in a similar fashion as that of the cup element 38 . At first, a sheet-shaped starting material is heated to a suitable processing temperature in a heating area connected in series with the thermoforming die and pulled into the gap 45 present between the lower die and the upper die with the thermoforming die being open. During a subsequent closing movement of the upper die in the direction of the lower die the perforating element 5 leading the clamping frame and the cutting knife 15 is first of all put on the sheet material. The mechanical weakening is introduced into the material. Subsequently, the clamping frame slightly leading the cutting knife 15 touches down and, together with the counterpunching plate, fixes the sheet material. Due to a further feed the cutting knife 15 gets into its desired final position relative to the lower die. The further shaping of the plastic material is implemented by generating a molding pressure in the area between the upper die and the sheet material and/or by generating a subpressure in the area between the lower die and the sheet material. The lid element 39 is punched out by means of the circumferential cutting edge 47 at the counterpunching plate. After a suitable cooling time—the thermoforming die may also be designed in a cooled fashion—lower die and upper die are opened, whereupon the produced lid element 39 is ejected from the lower die by means of a feed of the mold bottoms 18 and removed from the thermoforming die. The process described above is repeated for the production of further lid elements 39 .
As can be gathered from FIG. 3 the elastomer elements 54 are introduced into the counter support 11 . The elastomer elements 54 serve for compensating for e.g. alignment errors, dimensional imperfections or heat- or load-induced deformations between the counter support 11 and the perforating element 5 and possibly present lateral perforating elements 51 and their wear due to an elastic deformation.
Whereas the mechanical weakening is introduced into the lid element 39 by means of the perforating element 5 and the lateral perforating elements 51 in FIG. 3 , this can also be exclusively implemented with the one-part perforating element 5 which is schematically represented in FIG. 4 . It has a cutting edge which is designed in a “toothed” fashion, which is also designated as perforating or stamping cutting edge. This cutting edge consists of teeth 20 which determinate the perforating width, recesses 21 present between the teeth 20 , which determine the web width of the perforation, the recesses 21 receding by the stamping depth 22 with respect to the teeth 20 . Further parameters determining the perforation to be produced are the pitch 23 , the width of the perforating or stamping cutting edge 25 and the blade angle 26 . The element represented in FIG. 4 has a cutting edge which is altogether substantially designed in a bridge-shaped fashion with two segments 59 disposed at the side of the central cutting edge section 57 and adjoining sections 58 for forming perforation areas outside the plane of the lid panel and/or the section 57 .
FIG. 6 shows two modified embodiments of the perforating element 5 represented in FIG. 4 . In these modification resilient springs 27 are introduced into the perforating element 5 as in the counter support 11 described above, which serve for compensating for alignment errors, deviations, etc. between the counter support 11 and the perforating element 5 . The resilient springs 27 have a relief curve 28 in their end area, which is substantially designed in a circular segment shaped fashion and serves for minimizing the notch effect introduced into the counter support 11 by the resilient springs 27 . The feed possibilities of a perforating element which is similar to the perforating element 5 represented in FIGS. 2 and 3 are also made clear in the middle and at the bottom of FIG. 6 . The feed of the perforating element 5 takes place independently of the feed of the lateral perforating elements 51 in the upper righthand illustration, but in both cases in the direction of the lower die. The feed of perforating element 5 and lateral perforating elements 51 takes place in the righthand bottom illustration independently both in terms of time and direction.
A few possibilities are represented in FIG. 5 as to how the counter support 11 can be designed in accordance with the perforating element used for a use in the present invention in a fixed or flexible fashion, i.e. with corresponding compensating elements for alignment errors, deviations, etc.
In the first alternative the counter support 11 is designed as a solid block. This counter support 11 is customarily used with a perforating element 5 according to FIG. 6 . In another embodiment the counter support is designed in two parts, both segments 29 , 30 being biased by means of a compensating spring 31 . Both elements of the counter support 11 are displaceably accommodated in the lower die so that they can carry out the compensating movement outlined in FIG. 5 due to this displaceable accommodation and the bias by means of the balancing spring 31 . Similar or identical compensating movements can be achieved by the use of an elastomer element 54 . In the represented case two elastomer elements 54 are used which subdivide the counter support 11 into a central portion 55 and two outer segments 29 , 30 . A further possibility is the introduction of resilient springs, preferably with relief curves 28 .
The process according to the invention and the die according to the invention were described above by way of example with reference to the production of a food packaging with a cup element 38 and a matching lid element 39 . The mechanical weakening in the form of a stamping 33 or a perforation 34 , which is introduced into the lid element 39 and the cup element 38 in the connecting web area, serves for the fact that the user can individually separate the individual parts of the food packaging designed as a container with two or several units in each case from the remainder of the food package and can consume them (cf. FIGS. 9 and 10 ). However, in addition to this, further application possibilities (not shown) are given for the present invention. Thus, it is possible to e.g. produce lid elements in which a lid has a mechanical weakening consisting of a perforation and a stamping, which is disposed in a corner area of the lid. Due to the mechanical weakening introduced into the lid it is possible for a user to tear it open along the perforation. The mechanical weakening consisting of stamping and perforation subdivides the lid into two functional areas, namely, on the one hand, a reclosable lid element and the remaining part of the lid. Due to the edge-side shaping of the lid and the possibly provided use of snaps the lid element is reclosable. An application for such a lid is e.g. packagings for deep-freeze herbs or similar goods for forming a pour opening.
In another lid an opening for a drinking straw may be formed in the area of the lid panel. It is determined by a mechanical weakening which also consists of a stamping and a perforation and can be opened by a user. Such lid elements are e.g. suitable for containers for hot beverages and cold beverages in the fast food sector. | The invention relates to a process for producing thermoformed articles such as food packagings or parts thereof with a mechanical weakening between adjoining functional areas, which, for utilization by a user, can be at least partly separated at the mechanical weakening, in a thermoforming die having an upper die and a lower die, the mechanical weakening being introduced with a three-dimensional extension during the period of time during which the material to be formed is located in the thermoforming die, and a thermoforming die for implementing the process. | 1 |
RELATED APPLICATION
[0001] This is a divisional application of application Ser. No. 10/654,545 filed Sep. 3, 2003 which is a continuation of application Ser. No. 09/981,282 filed Oct. 18, 2001, which issued as U.S. Pat. No. 6,641,819, which is a continuation-in-part of application Ser. No. 09/461,879 filed Dec. 15, 1999, which is now abandoned, which is a continuation-in-part of application Ser. No. 09/298,110 filed Apr. 22, 1999, which is now abandoned.
SEQUENCE DISCLOSURE
[0002] A Sequence Listing in the form of a computer readable ASCII file in connection with the present invention was filed in application Ser. No. 09/981,282. This earlier filed CRF is incorporated herein by reference and applicant requests that this previously filed CRF be used as the CRF for this application. A paper copy of this sequence is included herein and is identical to this previously-filed CRF.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention is broadly concerned with attenuated avirulent atypical porcine reproductive and respiratory syndrome (PRRS) virus (PRRSV), and corresponding live virus vaccines for administration to swine in order to confer effective immunity in the swine against PRRSV. The invention also includes methods of immunizing swine against PRRSV, and a new, highly efficient method of passaging viruses to attenuation. Furthermore, the invention provides methods of detecting and differentiating between field strains and an attenuated strain of PRRSV.
[0005] 2. Description of the Prior Art
[0006] PRRS emerged in the late 1980's as an important viral disease of swine. PRRSV causes severe reproductive failure in pregnant sows, manifested in the form of premature farrowings, increased numbers of stillborn, mummified and weak-born pigs, decreased farrowing rate, and delayed return to estrus. Additionally, the respiratory system of swine infected with PRRSV is adversely affected, which is evidenced by lesions that appear in the lungs of infected swine. To combat the problems associated with PRRSV infection, vaccines have been developed which conferred immunity to then extant PRRSV strains.
[0007] Epidemics of an unusually severe form of PRRS, referred to hereafter as “atypical PRRS”, were first recognized in North America in the latter part of 1996. They differed from epidemics of “typical PRRS” in that: 1) clinical signs were more prolonged as well as more severe; 2) the incidence of abortion was greater, especially during early and middle gestation; 3) there was a higher incidence of gilt and sow mortality: 4) PRRSV was less often isolated from aborted fetuses, stillborn pigs, and liveborn pigs—perhaps because abortions were more often the result of acute maternal illness rather than transplacental infection; 5) lung lesions of young affected pigs were more extensive; and 6) commercially available vaccines provided little or no protection. Collectively these observation indicated the emergence of more virulent and antigenically distinct strains of PRRSV and the need for a new generation of PRRS vaccines.
[0008] The most frequently used method for producing attenuated, live-virus vaccine is to serially passage the virus in a substrate (usually cell culture) other than the natural host (S) until it becomes sufficiently attenuated (i.e., reduced in virulence or diseases-producing ability) to be used as a vaccine. For the first passage, a cell culture is infected with the selected inoculum. After obtaining clear evidence of virus replication (e.g., virus-induced cytopathic effects [CPE] in the infected cells), an aliquot of the cell culture medium, or infected cells, or both, of the first passage are used to in feet a second cell culture. The process is repeated until one or more critical mutations in the viral genome cause sufficient attenuation so that the virus can be safely used as a vaccine. The degree of attenuation is usually determined empirically by exposing the natural host (S) to progressively greater passage levels of the virus.
[0009] The above procedure is fundamentally sound and has been successfully used for the development of numerous vaccines for human and veterinary use. However, it is relatively inefficient because the logarithmic phase of virus replication, during which mutations are most likely to occur, is often completed long before evidence of virus replication becomes visibly obvious.
[0010] Therefore, there is a decided need in the art for a vaccine that confers effective immunity against PRRSV strains, including recently discovered atypical PRRSV strains. There is also a need in the art for a method of making such a vaccine. Finally, what is needed is a method of passaging a virus that attenuates the virus more efficiently than was heretofore thought possible with the resulting attenuated virus eliciting PRRSV specific antibodies in swine thereby conferring effective immunity against subsequent infection by PRRSV.
SUMMARY OF THE INVENTION
[0011] The present invention overcomes the problems outlined above, and provides attenuated, atypical PRRSV strains, and corresponding improved modified-live vaccines which confer effective immunity to newly discovered atypical PRRSV strains. “Effective immunity” refers to the ability of a vaccine to prevent swine PRRSV infections, including atypical PRRSV infections, which result in substantial clinical signs of the disease. That is to say, the immunized swine may or may not be serologically positive for PRRSV, but do not exhibit any substantial clinical symptoms. “Atypical PRRSV” refers to these new strains of PRRSV that are substantially more virulent than typical PRRSV strains.
[0012] In preferred forms, the vaccine of the invention includes live virus which has been attenuated in virulence. The resulting attenuated virus has been shown to be avirulent and to confer effective immunity. A particularly virulent strain of atypical PRRS (denominated JA-142) which caused especially severe symptoms of PRRS and represents the dominant strain of atypical PRRSV, was chosen for subsequent attenuation through passaging. The resultant attenuated virus has been deposited in the American Type Culture Collection (ATCC), Rockville, Md. on Feb. 2, 1999, and was accorded ATCC Accession No. VR-2638. This attenuated virus is a preferred Master Seed Virus (MSV) which has been subsequently passaged and developed as an effective PRRSV vaccine.
[0013] The name given the unattenuated virus. JA-142, arises from the restriction enzyme pattern. The 1 represents the inability or the enzyme MLU 1 to cleave the virus in open reading frame 5 (ORF 5). The 4 represents cleavage by Hinc II at base pair positions 118 and 249 of ORF 5 and short contiguous sequences. The 2 represents cleavage by Sac II at base pair position 54 of ORF 5 and short, contiguous sequences.
[0014] Additionally, the present invention provides another way to differentiate between field strains of PRRSV and strain JA-142. The method is based upon differences in RNA cleavage by a restriction enzyme, NspI. Briefly, isolated PRRSV RNA is subjected to digestion by NspI. Digestion of the attenuated strain, JA-142, results in at least one additional fragment in comparison to field strains of PRRSV. In preferred methods, the RNA is isolated and RT-PCR is performed on the isolated RNA. This RNA is then subject to electrophoresis and a 1 Kd product is identified and purified for digestion by NspI. This digestion results in three fragments for JA-142 and either one or two fragments for PRRSV field strains.
[0015] Passaging of the virus to attenuation was accomplished using a novel method which resulted in increased efficiency. Specifically, the virus was kept in the logarithmic phase of replication throughout multiple cell culture passages in order to materially shorten the time to attenuation. This is achieved by ensuring that in each cell culture there is a substantial excess of initially uninfected cells relative to the number of virus present. Thus, by transferring only small numbers of virus from passage-to-passage, logarithmic replication is assured.
[0016] In practice, the process is normally initiated by inoculation of several separate cell cultures with progressively smaller viral aliquots (i.e., lesser numbers of virus in each culture.) For example, starting cultures could contain 200 μl, 20 μl and 2 μl viral aliquots. After an initial short incubation period (e.g., ˜24 hours), the same viral aliquots (in the example, 200 μl, 20 μl and 2 μl) from each cell culture are transferred to individual fresh (previously uninfected) cultures, while the starting cultures are monitored until cytopathic effect (CPE) is or is not observed. This process is continued in serial order for multiple passages, using the same viral aliquots in each case and preserving the cultures for CPE observation. If all of the serial culture passages exhibit CPE after a selected number of passages are complete, the larger viral aliquot series may be terminated (in the example 200 μl and 20 μl), whereupon another series of progressively smaller viral aliquots are employed (e.g., 2 μl, 0.2 μl and 0.02 μl) and the process is again repeated, again keeping the cell cultures after transfer for CPE observation.
[0017] At some point in this successively smaller viral aliquot inoculation process. CPE will not be observed in a given cell culture. When this occurs, the next higher viral aliquot level showing CPE is substituted for the passage in which CPE was not observed, whereupon subsequent passages will be inoculated using previously employed viral aliquots.
[0018] Inasmuch as a virus will tend to become more efficient at infecting cells and also replicate to a higher infectivity titer for cell cultures over time, (which is especially true with RNA viruses such as PRRSV), it will be seen that smaller and smaller viral aliquots are required to maintain infection during serial transfer. The use of the smallest aliquot that maintains infection helps to assure that viral replication remains in a logarithmic phase throughout the process.
[0019] The DNA sequence of the attenuated passaged virus from the 201st passage was then determined using conventional methods. The sequence of this attenuated virus was designated as MSV JA-142 Passage No. 201, the sequence of which is given as SEQ ID No. 1. The sequence of the virulent virus, JA-142, is given as SEQ ID No. 2.
[0020] As used herein, the following definitions will apply: “Sequence Identity” as it is known in the art refers to a relationship between two or more polypeptide sequences or two or more polynucleotide sequences, namely a reference sequence and a given sequence to be compared with the reference sequence. Sequence identity is determined by comparing the given sequence to the reference sequence after the sequences have been optimally aligned to produce the highest degree of sequence similarity, as determined by the match between strings of such sequences. Upon such alignment, sequence identity is ascertained on a position-by-position basis, e.g., the sequences are “identical” at a particular position if at that position, the nucleotides or amino acid residues are identical. The total number of such position identities is then divided by the total number of nucleotides or residues in the reference sequence to give % sequence identity. Sequence identity can be readily calculated by known methods, including but not limited to, those described in Computational Molecular Biology, Lesk, A. N., ed., Oxford University Press, New York (1988). Biocomputing: Informatics and Genome Projects, Smith, D. W., ed., Academic Press, New York (1993); Computer Analysis of Sequence Data. Part I, Griffin. A. M., and Griffin, H. G., eds., Humana Press, New Jersey (1994); Sequence Analysis in Molecular Biology, von Heinge, G. Academic Press (1987); Sequence Analysis Primer, Gribskov, M. and Devereux. J., eds., M. Stockton Press, New York (1991); and Carillo, H., and Lipman, D., SIAM J. Applied Math., 48: 1073 (1988), the teachings of which are incorporated herein by reference. Preferred methods to determine the sequence identity are designed to give the largest match between the sequences tested. Methods to determine sequence identity are codified in publicly available computer programs which determine sequence identity between given sequences. Examples of such programs include, but are not limited to, the GCG program package (Devereux, J., et. al., Nucleic Acids Research, 12(1):387 (1984)), BLASTP, BLASTN and FASTA (Altschul, S. F. et al., J. Molec. Biol., 215:403-410 (1990). The BLASTX program is publicly available from NCBI and other sources (BLAST Manual, Altschul, S. et. al., NCVI NLM NIH Bethesda, Md. 20894, Altschul, S. F. et al., J. Molec. Biol., 215:403-410 (1990), the teachings of which are incorporated herein by reference). These programs optimally align sequences using default gap weights in order to produce the highest level of sequence identity between the given and reference sequences. As an illustration, by a polynucleotide having a nucleotide sequence having at least, for example, 95% “sequence identity” to a reference nucleotide sequence, it is intended that the nucleotide sequence of the given polynucleotide is identical to the reference sequence except that the given polynucleotide sequence may include up to 5 point mutations per each 100 nucleotides of the reference nucleotide sequence. In other words, in a polynucleotide having a nucleotide sequence having at least 95% identity relative to the reference nucleotide sequence, up to 5% of the nucleotides in the reference sequence may be deleted or substituted with another nucleotide, or a number of nucleotides up to 5% of the total nucleotides in the reference sequence may be inserted into the reference sequence. These mutations of the reference sequence may occur at the 5′ or 3′ terminal positions of the reference nucleotide sequence or anywhere between those terminal positions, interspersed either individually among nucleotides in the reference sequence or in one or more contiguous groups within the reference sequence. Analogously, by a polypeptide having a given amino acid sequence having at least, for example, 95% sequence identity to a reference amino acid sequence, it is intended that the given amino acid sequence of the polypeptide is identical to the reference sequence except that the given polypeptide sequence may include up to 5 amino acid alterations per each 100 amino acids of the reference amino acid sequence. In other words, to obtain a given polypeptide sequence having at least 95% sequence identity with a reference amino acid sequence, up to 5% of the amino acid residues in the reference sequence may be deleted or substituted with another amino acid, or a number or amino acids up to 5% of the total number of amino acid residues in the reference sequence may be inserted into the reference sequence. These alterations of the reference sequence may occur at the amino or the carboxy terminal positions of the reference amino acid sequence or anywhere between those terminal positions, interspersed either individually among residues in the reference sequence or in the one or more contiguous groups within the reference sequence. Preferably, residue positions which are not identical differ by conservative amino acid substitutions. However, conservative substitutions are not included as a match when determining sequence identity.
[0021] Similarly, “sequence homology”, as used herein, also refers to a method of determining the relatedness of two sequences. To determine sequence homology, two or more sequences are optimally aligned as described above, and gaps are introduced if necessary. However, in contrast to “sequence identity”, conservative amino acid substitutions are counted as a match when determining sequence homology. In other words, to obtain a polypeptide or polynucleotide having 95% sequence homology with a reference sequence, 95% of the amino acid residues or nucleotides in the reference sequence must match or comprise a conservative substitution with another amino acid or nucleotide, or a number of amino acids or nucleotides up to 5% of the total amino acid residues or nucleotides, not including conservative substitutions, in the reference sequence may be inserted into the reference sequence.
[0022] A “conservative substitution” refers to the substitution of an amino acid residue or nucleotide with another amino acid residue or nucleotide having similar characteristics or properties including size, hydrophobicity, etc. such that the overall functionality does not change significantly.
[0023] Isolated” means altered “by the hand of man” from its natural state, i.e., if it occurs in nature, it has been changed or removed from its original environment, or both. For example, a polynucleotide or polypeptide naturally present in a living organism is not “isolated,” but the same polynucleotide or polypeptide separated from the coexisting materials of its natural state is “isolated”, as the term is employed herein.
[0024] Preferably, sequences sharing at least about 75%, more preferably at least about 85%, still more preferably at least about 90% and most preferably at least about 95% sequence homology with SEQ ID No. 1 are effective as conferring immunity upon animals vaccinated with attenuated viruses containing such homologous sequences. Alternatively, sequences sharing at least about 65%, more preferably at least about 75%, still more preferably at least about 85%, and most preferably at least about 95% sequence identity with SEQ ID No. 1 are also effective at conferring immunity upon animals vaccinated with attenuated viruses containing such identical sequences.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a graph illustrating the ratio of samples which tested positive for antibodies against PRRSV to the total number of samples over a 196 day testing period; and
[0026] FIG. 2 is a graph illustrating the ratio of samples which tested positive for antibodies against PRRSV to the total number of samples over a 38 day testing period after challenge.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] The following examples set forth preferred embodiments of the present invention. It is to be understood, however, that these examples are provided by way of illustration and nothing therein should be taken as a limitation upon the overall scope of the invention.
Example 1
Materials and Methods
[0028] This example describes a passage method of attenuating viruses which maximizes attenuation efficiency by ensuring that the virus is preferably in a logarithmic phase of replication. Virus was passed (i.e. an aliquot of nutrient medium including the virus, unattached cells, and cell debris from a virus-infected cell culture was added to the nutrient medium of a noninfected culture) at daily intervals. Different amounts of virus were added at each interval by using multiple cultures. For example, at the beginning, 200 μl was transferred to one noninfected culture, 20 μl was added to a second noninfected culture, and 2 μl to a third noninfected culture. The goal was to have a sufficient amount of susceptible cells so that the replication cycles could continue until the next transfer. The procedure was deemed successful if the cells eventually showed CPE. However, because PRRSV-induced CPE do not appear until sometime after the logarithmic growth phase, passages were made before it was known whether or not they would be ultimately successful (“blind passages”). Passages that resulted in virus induced CPE were said to have resulted in a “take”. If a passage did not result in a take, the passage was restarted using the highest dilution from the last passage which did result in a take. As more and more passages were made, the virus became more adapted to replicate in the cell line and less able to produce disease symptoms in its original host. These changes occur through random mutations that occur during replication.
[0029] Using this method, the following procedures were used to passage an exemplary virus in accordance with the present invention, MSV, JA-142. This strain was passaged in MARC-145 cell cultures at daily intervals. Twenty-four-well plates were used for the process to minimize the amount of cells and nutrient medium required, and to simplify the multiple-aliquot passage technique. Cells and nutrient medium were added to each well and the cells were allowed to form, or nearly form (greater than about 70%), a confluent monolayer. The nutrient medium comprised approximately 90% Earle's balanced salt solution minimal essential medium (MEM), 10% fetal calf serum and 0.05 mgm/ml of gentamicin sulfate. The volume of nutrient medium used was approximately 1 ml. Usually, three wells of a column were used for each amount of virus that was transferred. An aliquot of nutrient medium from the previous passage was transferred to the first well in the column at 48 or 72 hours, after the cell cultures had been prepared, nutrient medium from the first well was transferred to the second well of the same column at 72 or 96 hours and the third well of the same column at 96 or 120 hours. Plates were usually set up twice a week so sometimes the fourth well of the column was used and sometimes it was not used. Passaging conditions were maintained at 37° C. in a moist atmosphere containing 5% CO 2 .
[0030] Different sized aliquots (having different amounts of virus) for each passage were tested to determine if the amount of virus was sufficient to induce CPE. For example, a separate series of aliquot transfers (passages) of 200 μl, 20 μl, and 2 μl, respectively, was used until the smaller aliquots consistently exhibited CPE with the goal being to transfer the smallest aliquot that produced CPE. When the smallest aliquot (e.g. 2 μl) of the group of aliquots being tested consistently resulted in CPE, smaller amounts were tested (e.g. 0.2 μl and 0.02 μl). When a certain dilution did not exhibit CPE, that series of cultures was restarted with the next lower amount which did result in CPE at that passage (i.e. if the 2 μl transfer was unsuccessful at producing CPE in the 25th passage but the 20 μl transfer in the 25th passage was successful, the 2 μl transfer was repeated using 20 μl with 2 μl transfers resuming for the 26th passage.)
[0031] Using this method, the smallest amount of virus necessary to transfer to obtain CPE was determined. Virus was passed successfully at daily intervals using the following amounts of virus-infected nutrient medium (which reflect the highest dilution [i.e., smallest aliquot] which resulted in CPE keeping in mind that other dilutions would also work):
[0000]
Passage Number
Amount Transferred
3-21
200
μl
22, 23
20
μl
24-41
200
μl
42-83
20/200
μl (alternating)
84-90
20
μl
91-112
2
μl
113
0.2
μl
114-116
2
μl
117
0.2
μl
118-120
2
μl
121
0.2
μl
122-124
2
μl
125-167
0.2
μl
168
0.02
μl
169-171
0.2
μl
172
0.02
μl
173-175
0.2
μl
176
0.02
μl
177-179
0.2
μl
180
0.02
μl
181-183
0.2
μl
184
0.02
μl
185-187
0.2
μl
188
0.02
μl
189-191
0.2
μl
192
0.02
μl
193-195
0.2
μl
196
0.02
μl
197
0.2
μl
Results and Discussion
[0032] The passaging of the virus using the above method resulted in an attenuated PRRSV, JA-142. As is apparent, the virus became more adapted to replicate in the cell culture and therefore required a smaller amount of virus-infected nutrient medium to be transferred as passaging continued. For transfers using a very small amount of virus-infected nutrient medium (e.g. 0.2 μl or 0.02 μl), a separate dilution was required. This dilution was accomplished by adding a small amount of virus-infected nutrient medium to a larger amount of nutrient medium. For example, to obtain a transfer of 0.2 μl, 2 μl of virus infected nutrient medium was added to 20 μl of nutrient medium and 2 μl of this dilution was added to the next culture in the series. Using this approach, the highest dilution which resulted in CPE was used and the time necessary for passaging the virus was minimized. Passaging at daily intervals ensured that the virus was always in a logarithmic phase of replication. Daily transferring also ensured that there was an adequate number of cells for virus replication.
[0033] Because the mutations (which are probably cumulative) that are likely to result in attenuation only occur during replication, there is no advantage to having substantially all cells infected and replication either proceeding at a slower rate or stopping before the next transfer. Based on previous studies of PRRSV, it was known that the replication cycle is about 8 hours, therefore, transferring a minimal amount of virus from virus-infected nutrient medium to uninfected nutrient medium at daily intervals results in the virus always having plenty of cells within which to replicate.
[0034] As can be readily appreciated, passaging using this method results in a savings of time that was heretofore thought impossible (i.e. each passage required less time). This is especially important when a high number of passages are required for adequate virus attenuation. If each passage, using old methods, was performed at a 3 day interval, a procedure requiring 200 passages would take 400 fewer days using the method of the present invention.
Example 2
Materials and Methods
[0035] This example determined if passage 200 of PRRS Virus, JA-142, would revert in virulence when passed in the host animal six times. This study consisted of six groups. Five pigs from group 1 (principle group) were inoculated intra-nasally with PRRS MSV, JA-142 passage 200, while three pigs from group 1A, (control group) were inoculated intra-nasally with sterile diluent. The animals were provided commercial feed and water ad libitum throughout the study. Pigs of both treatment groups were monitored daily for clinical signs (appearance, respiratory, feces, etc.). After six days, the animals were weighed, bled and sacrificed. After scoring the lungs for lesions, lung lavages were collected from each animal. The lung lavages were frozen and thawed one time, and a pool was prepared using 2.0 ml of serum and 2.0 ml of lung lavage from each animal within a group to prepare Backpassage 1 and 1A, respectively. This pool was used to challenge (intra-nasally) the animals in group 2 and group 2A, respectively. This process was repeated for groups 3 and 3A through 6 and 6A. Animals in each group were housed in separate but identical conditions.
[0036] Following inoculation, blood samples were collected and body temperatures were monitored. Rectal temperatures were measured for each animal periodically from −1 DPE (days post exposure) to 6 DPE and averaged together with other animal temperatures from the same group. The health status of each animal was monitored daily for the duration of the study. Results were compiled and scored on a daily observation form. The scoring parameters are as follows:
[0037] 1. Appearance
normal=0; depressed=1; excited=2; comatose/death=30.
[0039] 2. Respiration
normal=0; sneeze=1; cough=1; rapid/short=2; labored=3.
[0041] 3. Feces
normal=0; dry=; loose=fluid=3.
[0043] 4. Eyes
normal=0; watery=1; matted=2; sunken=3.
[0045] 5. Nostrils
normal=0; watery discharge=1; red/inflamed=2; crusted ulcers=3.
[0047] 6. Mouth
normal=0; slobbers=2; ulcer=3.
[0049] 7. Activity
NA
[0051] 8. Appetite
normal=0; decreased=1; anorexic (none)=3.
[0053] 9. Other
[0054] Animals were also weighed prior to inoculation and at necropsy. Average weight gains for each group were calculated for comparison. PRRS Enzyme Linked Immuno-Absorbent Assays (ELISA) and serum neutralization (SN) assays were performed following the exposures of the animals with test and control articles. Attempts to isolate PRRSV from serum samples were performed on MA-104 cells. Prior to and following vaccination, total white blood cell counts were determined using COULTER COUNTER MODEL Z1, Coulter Corp., Miami, Fla. At necropsy, the lungs of each animal were scored. Lung scoring was done by separating the lung into 7 sections and determining the percentage of lung involvement (the percentage of the lung area affected as shown by lesions or redness for each section and multiplying by the approximate area of the whole lung) that percentage of total lung area that the section encompasses. Parameters for lung scoring are as follows:
[0000]
Left Apical Lobe % of involvement × 0.10 =
Left Cardiac Lobe % of involvement × 0.10 =
Left Diaphragmatic Lobe % of involvement × 0.25 =
Right Apical Lobe % of involvement × 0.10 =
Right Cardiac Lobe % of involvement × 0.10 =
Right Diaphragmatic Lobe % of involvement × 0.25 =
Intermediate Lobe of Right Lung % of involvement × 0.10 =
Total (Sum of all values in the far right column) =
Results and Discussion
[0055] Each group of pigs was monitored for six days following vaccination. Clinical scores were low in all groups. Clinical score results are given in Table 1.
[0000]
TABLE 1
Daily Clinical Scores
Treatment
Day −1
Day 0
Day 1
Day 2
Day 3
Day 4
Day 5
Day 6
Average
Group 1
Pig #
JA-142 psg 200
545
0
0
2
0
0
0
0
0
0.25
551
0
0
0
0
0
0
0
0
0
561
0
0
0
0
0
0
0
0
0
565
0
0
0
0
0
0
0
0
0
806
0
0
0
0
0
0
0
0
0
Average
0
0
0.4
0
0
0
0
0
0.05
Saline
550
0
0
0
0
0
0
0
0
0
568
0
0
0
0
0
0
0
0
0
801
0
0
0
0
0
0
0
0
0
Average
0
0
0
0
0
0
0
0
0
Group 2
Pig #
Backpassage 1
546
0
0
0
0
0
0
0
0
0
553
0
0
0
0
0
0
0
0
0
562
0
0
0
0
0
1
0
0
0.125
572
0
0
0
0
0
0
0
0
0
573
0
0
0
0
2
0
0
0
0.25
Average
0
0
0
0
0.4
0.2
0
0
0.075
Backpassage 1
556
0
0
0
0
0
0
0
0
0
566
0
0
0
0
0
0
0
0
0
802
0
0
0
0
0
0
0
0
0
Average
0
0
0
0
0
0
0
0
0
Group 3
Pig #
Backpassage 2
548
0
0
0
0
0
0
0
0
0
567
0
0
0
0
0
0
0
0
0
569
0
0
0
0
1
1
0
0
0.25
574
0
0
0
0
0
0
0
0
0
804
0
0
0
0
0
0
0
0
0
Average
0
0
0
0
0.2
0.2
0
0
0.05
Backpassage 2A
547
0
0
0
0
0
0
0
0
0
5564
0
0
0
0
0
0
0
0
0
805
0
0
0
0
0
0
0
0
0
Average
0
0
0
0
0
0
0
0
0
Group 4
Pig #
Backpassage 3
549
0
0
0
0
0
0
0
0
0
554
0
0
0
0
0
0
0
0
0
563
0
0
0
0
0
0
0
0
0
570
0
0
0
0
0
0
0
0
0
803
0
0
0
0
0
0
0
0
0
Average
0
0
0
0
0
0
0
0
0
Backpassage 3A
560
0
0
0
0
0
0
0
0
0
571
0
0
0
0
0
0
0
0
0
575
0
0
0
0
0
0
0
0
0
Average
0
0
0
0
0
0
0
0
0
Group 5
Pig #
Backpassage 4
1
0
2
0
0
2
0
2
2
1
2
0
0
0
0
0
0
0
0
0
3
2
0
2
2
2
2
2
2
1.75
4
0
0
0
0
0
0
0
0
0
5
0
0
0
0
0
0
0
0
0
Average
0.4
0.4
0.4
0.4
0.8
0.4
0.8
0.8
0.55
Backpassage 4A
6
0
0
0
0
0
0
0
0
0
7
0
0
2
2
2
2
2
2
1.5
8
0
0
0
0
0
0
0
0
0
Average
0
0.08
0.48
0.48
0.56
0.48
0.56
0.56
0.4
Group 6
Pig #
Backpassage 5
10
0
0
0
0
2
0
0
2
0.5
12
0
0
0
2
2
0
0
2
0.75
14
0
0
0
0
0
0
0
0
0
15
2
2
2
0
0
0
0
2
1
16
2
2
2
0
0
1
1
2
1.25
Average
0.8
0.8
0.8
0.4
0.8
0.2
0.2
1.6
0.7
Backpassage 5A
9
0
0
0
0
0
0
0
0
0
11
2
2
0
0
0
0
0
0
0.5
13
0
0
0
0
0
0
0
0
0
Average
0.666667
0.56
0.16
0.08
0.16
0.04
0.04
0.32
0.253333
[0056] There were no significant differences between groups for rectal temperatures or daily weight gains. All lung scores were negative.
[0057] Serologically, ELISA S/P ratios and SN titers were negative throughout each group's trial period. Virus isolation was attempted on all serum samples and lung lavages. By day 6, 60-100% of the serum samples from the groups given JA-142, passage 200, and subsequent back passes were positive. The groups given saline were negative. In the first three passes, virus was recovered in the lung lavages from only 20-40% of the pigs, but by the last three passes, the virus was recovered from 50-80% of the pigs.
[0058] Based on this data, JA-142 passage 200 did not revert to virulence when passed through pigs six times.
Example 3
Materials and Methods
[0059] This example demonstrated that the level of attenuation of safety of MSV, JA-142, passage 200 did not change significantly during six backpassages in the host animal. Evaluation of level of attenuation or safety was performed using the pregnant sow model and monitoring the effect on reproductive performance. This model is the most sensitive test system and does not rely upon subjective factors for virulence testing. This example consisted of four groups (A, B, C & D) having seven sows per group. Group A was inoculated intra-nasally with PRRS MSV, JA-142 passage 200. Group B was inoculated intra-nasally with JA-142, passage 200, Backpassage 6. Group C was inoculated intra-nasally with sterile diluent, to act as normal controls. Group D was inoculated intra-nasally with PRRSV JA-142, passage 4. The test articles (challenge with JA-142, passage 4) were given at about 93 days gestation. Body temperatures of the sows were monitored for the first seven days following vaccination. Blood samples were collected from the sows once a week and at time of farrowing. Blood samples were collected and weights were recorded from piglets at birth, 7, and 14 days of age. The health status of each animal was monitored daily for the duration of the study up to and following farrowing for 14 days. The farrowing performance was evaluated by observing the health status of the piglets born.
[0060] PRRS ELISA assays were performed following the exposures of the sows with the test article. PRRS ELISA assays were also performed on the piglet sera weekly following farrowing. Following exposure to the test article, attempts to isolate PRRSV from scrum samples were performed on MA-104 cells. Rectal temperatures were measured periodically from 0 days post vaccination (DPV) to 7 DPV and the average temperature of each group was determined. Prior to and after inoculation, total white blood cell counts were determined as in Example 1. Clinical observations of the sows, as in Example 2, were made from −1 DPV through farrowing. Clinical observations of the piglets were made from farrowing until 14 days of age. Finally, at necropsy, the lungs of each piglet were scored for percent lung involvement.
Results
[0061] The ELISA results indicate that the animals used in this study were naive to PRRSV. Those animals that received virus inocula, groups A, B, and D, sero-converted at 14 days post treatment. Three sows of group B remained negative at 14 days post treatment. At the time of farrowing, the negative sows of group B tested positive for antibody to PRRSV.
[0062] The pigs' ELISA results indicated that the majority of the piglets born to sows of group A and group B were sampled after they had nursed. Those pigs that were negative at zero days post farrowing (0 DPF) tested positive at 7 DPF. All pigs born to sows of group C tested sero-negative throughout the study. Only a few pigs were tested from group D, since the majority were either stillborn or mummies. Half of those pigs that were tested were sero-positive. This indicated that the sero-negative pigs were sampled prior to nursing or they were not capable of nursing. All piglets born to sows of group D died before 7 DPF. Isolations of PRRSV from the sows of groups A and B were sporadic. Although the results of the ELISA test indicated that these sows were successfully inoculated with the viral test articles, many remained negative for virus isolation from serum.
[0063] The majority of pigs born to sows from groups A and B tested positive for virus isolation during the performance of the study. The litter born to one sow of group A never tested positive and the litter born to one sow of group B had only two of eight piglets test positive for virus isolation. No virus was recovered from the piglets born to sows from group C. Virus was recovered from the majority (71%) of piglets born from sows of group D.
[0064] Post treatment rectal temperatures were unremarkable. The groups that were treated with either MSV, backpassage 6 or sterile diluent experienced no measurements exceeding 101.7° F. Group D, treated with JA-142, passage 4, had lour (out of seven) sows that experienced temperatures that exceeded 102° F. with one sow reaching 103.4° F. for one of the days. The weight gain performance of the piglets born to sows of groups A (treated with MSV) and B (treated with MSV, backpassage 6) was greater than that of the pigs born to the control sows of group C. The average weight gain for the 14 day observation period was 7.9 lbs. For group A, it was 7.7 lbs; for group B and group C it was 6.9 lbs. The difference in the weight gain was not related to the size of the litter remaining at 14 days. The average litter sizes at 14 days post farrowing (DPF) were 9 for group A, 7 for group B, and 10 for group C. No pig born to the sows of group D survived beyond 3 DPF.
[0065] The white blood cell (WBC) counts for the sows of groups A, B, and C remained relatively constant. The average percentages of the pre-challenge values were equal to or greater than 92% for the duration of the observation period. Three sows of group D experienced WBC counts that were lower than the expected normal range (7-20×10 6 /ml).
[0066] The post inoculation clinical scores were unremarkable for the sows of groups A and B. Several sows of group C were observed to experience clinical signs over a period of several days. The majority of the clinical symptoms observed were in the category of decreased appetite, respiratory symptoms, and depression. One sow of group C died on trial day 31 of chronic bacterial pneumonia. Six of the seven sows of group D were observed to have clinical signs, primarily of varying degrees in severity, of lost appetite, ranging from decreased to anorexic. Results of the clinical scoring for the sows are given in Table 2.
[0000]
TABLE 2
Sow Clinical Scores
Treatment
Sow#
−3
−2
−1
0
1
2
3
4
5
6
7
8
9
10
11
12
Group A
98
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
JA-142 MSV
133
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Passage 200
147
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
178
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
215
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
233
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
243
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Group A
98
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
JA-142 MSV
133
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Passage 200
147
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
178
0
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
215
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
233
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
243
0
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0.6
0
0
0
0
0
0
0
0
0
0
0
0
0
0
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
Group A
98
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
JA-142 MSV
133
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Passage 200
147
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
178
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
215
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
233
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
243
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Treatment
Sow#
−3
−2
−1
0
1
2
3
4
5
6
7
8
9
10
11
12
Group B
49
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Backpassage6
100
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
135
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
149
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
209
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
212
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
226
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0
0
0
0
0
0
0
0
0
0
0.1
0.1
0.1
0.1
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Group B
49
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Backpassage6
100
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
135
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
149
0
0
0
0
0
0
0
1
1
0
0
0
0
0
0
0
209
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
212
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
226
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0
0
0
0
0
0.1
0.1
0
0
0
0
0
0
0
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
Group B
49
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Backpassage6
100
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
135
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
149
0
0
0
0
0
0
0
0
0
0
2
2
2
2
2
2
209
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
212
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
226
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0
0
0
0
0
0
0
0
0.3
0.3
0.3
0.3
0.3
0.3
Treatment
Sow#
−3
−2
−1
0
1
2
3
4
5
6
7
8
9
10
11
12
Group C
58
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Sterile
113
0
0
0
0
0
0
0
0
0
0
1
3
3
5
3
3
Diluent
117
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
144
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
156
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
166
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0
0
0
0
0
0
0
0
0.2
0.5
0.5
0.8
0.7
0.7
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Group C
58
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Sterile
113
3
3
3
3
3
3
4
4
4
4
6
6
2
4
2
2
Diluent
117
0
0
0
0
0
0
1
5
5
5
5
5
2
4
1
1
144
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
156
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
166
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0.8
0.5
0.5
0.5
0.5
0.5
0.8
1.5
1.5
1.5
1.8
1.8
0.7
1.3
0.5
0.5
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
Group C
58
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Sterile
113
2
2
30
Diluent
117
2
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
144
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
156
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
166
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0.7
0.7
6
0
0
0
0
0
0
0
0.2
0.2
0.2
0.2
0.2
0.2
Treatment
Sow#
−3
−2
−1
0
1
2
3
4
5
6
7
8
9
10
11
12
Group D
2
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
JA-142
106
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
Pass 4
159
0
0
0
0
0
0
0
0
0
3
1
1
1
1
1
1
190
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
206
0
0
0
0
0
0
0
0
0
0
1
1
0
0
0
0
232
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
234
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
Avg.
0
0
0
0
0
0
0
0
0
0.6
0.6
0.6
0.6
0.7
0.7
0.7
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Group D
2
1
1
3
3
1
0
0
0
0
0
0
0
0
0
0
0
JA-142
106
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Pass 4
159
1
1
1
1
3
4
2
3
3
3
2
0
0
2
0
0
190
1
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
206
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
232
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
234
0
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0.4
0.3
0.6
0.6
0.6
0.6
0.3
0.4
0.4
0.4
0.3
0
0
0.3
0
0
29
30
31
32
33
34
35
36
37
38
Group D
2
0
0
0
1
1
1
3
3
1
1
JA-142
106
0
0
0
0
0
0
0
0
0
0
Pass 4
159
0
0
0
0
0
0
0
0
0
0
190
0
0
0
0
0
0
0
0
0
0
206
0
0
0
0
0
0
0
0
0
0
232
0
0
0
0
0
0
0
0
0
0
234
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0
0.1
0.1
0.1
0.4
0.4
0.1
0.1
[0067] Clinical observations of the piglets fell into two major categories, death and reduced appetite. There were no significant differences between groups A, B and C in the area of average deaths per litter (DPL). Group A had an average of 1.3 DPL, group B had an average of 2.4 DPL, group C had an average of 2.0 DPL, and no pigs from group D survived beyond three days post farrowing. Clinical scores for the piglets are given in Table 3.
[0000]
TABLE 3
Treatment
Sow#
Pig#
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Group A
98
813
0
0
1
30
JA-142
814
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Pass 200
815
0
0
0
0
0
0
0
0
0
0
0
0
0
0
816
0
0
0
0
0
0
0
0
0
0
0
0
0
0
817
1
0
1
0
0
0
0
0
0
0
0
0
0
0
818
0
0
0
0
0
0
0
0
0
0
0
0
0
0
819
0
0
0
0
0
0
0
0
0
0
0
0
0
0
820
0
0
0
0
0
0
0
0
0
0
0
0
0
0
821
1
0
0
0
0
0
0
0
0
0
0
0
0
0
822
1
30
Avg.
0.3
3
0.2
3.3
0
0
0
0
0
0
0
0
0
0
133
720
30
721
0
1
0
0
0
0
0
0
0
0
0
0
0
0
722
0
0
0
1
0
0
0
0
0
0
0
0
0
0
723
0
0
0
0
0
0
0
0
0
0
0
0
0
0
724
0
1
0
0
0
1
0
0
0
0
0
0
0
0
725
0
0
0
0
0
0
0
0
0
0
0
0
0
0
798
0
0
0
0
0
0
0
0
0
0
0
0
0
0
799
30
800
0
0
0
0
0
0
0
0
0
0
0
0
0
0
807
0
0
0
0
0
0
0
0
0
0
0
1
0
0
809
0
0
0
0
0
0
0
0
0
0
0
0
0
0
810
0
0
0
0
0
0
0
0
0
0
0
0
0
0
812
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
4.6
0.2
0
0.1
0
0.1
0
0
0
0
0
0.1
0
0
147
823
0
0
0
0
0
0
0
0
0
0
0
0
0
0
824
0
0
0
0
0
0
0
3
1
1
1
1
1
1
825
0
0
0
0
0
0
0
0
0
0
0
0
0
0
845
0
0
0
0
0
0
0
0
0
0
0
0
0
0
846
0
0
0
0
0
0
0
0
0
0
0
0
0
0
847
0
0
0
0
0
0
0
0
0
0
0
0
0
0
848
0
0
0
0
0
0
1
0
0
0
0
0
0
0
849
0
0
0
0
0
0
0
0
0
0
0
0
0
2
850
30
976
0
0
0
0
0
0
0
0
0
0
0
0
0
0
977
0
0
0
0
1
1
3
30
978
30
Avg.
5
0
0
0
0.1
0.1
0.4
3.3
0.1
0.1
0.1
0.1
0.1
0.3
178
486
30
487
0
0
0
0
0
0
0
0
0
0
0
1
0
0
488
0
0
0
0
0
0
0
0
0
0
0
0
0
0
489
0
0
0
0
0
0
0
0
0
0
0
0
0
0
490
0
0
0
0
0
0
0
0
0
0
0
0
0
0
491
0
0
0
0
0
0
0
0
0
0
0
0
0
0
492
0
0
0
0
0
0
0
0
0
0
0
0
0
0
493
0
0
0
0
0
0
0
0
0
0
0
0
0
0
494
0
1
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
3.3
0.1
0
0
0
0
0
0
0
0
0
0.1
0
0
Group A
215
495
0
0
0
0
0
0
0
0
0
0
0
0
0
0
JA-142
496
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Pass 200
497
0
0
0
0
0
0
0
0
0
0
0
0
0
0
498
0
0
0
0
0
0
0
0
0
0
0
0
0
0
499
0
0
0
0
0
0
0
0
0
0
0
0
0
0
500
0
0
0
0
0
0
0
0
0
0
0
0
0
0
808
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0
0
0
0
0
0
0
0
0
0
0
0
233
476
0
0
0
0
0
0
0
0
0
0
0
0
0
0
477
0
0
0
0
0
0
0
0
0
0
0
0
0
0
478
0
0
0
0
0
0
0
0
0
0
0
0
0
0
478
0
0
0
0
0
0
0
0
0
0
0
0
0
0
480
0
0
0
0
0
0
0
0
0
0
0
0
0
0
481
0
0
0
0
0
0
0
0
0
0
0
0
0
0
482
0
0
0
0
0
0
0
0
0
0
0
0
0
0
483
0
0
0
0
0
0
0
0
0
0
0
0
0
0
484
0
0
0
0
0
0
0
0
0
0
0
0
0
0
485
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0
0
0
0
0
0
0
0
0
0
0
0
243
707
0
0
0
0
0
0
0
0
0
0
0
0
0
0
708
0
0
0
0
0
0
0
0
0
0
0
0
0
0
709
0
0
0
0
0
0
0
0
0
0
0
0
0
0
710
0
0
0
0
0
0
0
0
0
0
0
0
0
0
711
0
0
0
0
0
0
0
0
0
0
0
0
0
0
712
0
0
0
0
0
0
0
0
0
0
0
0
0
0
713
0
0
0
0
0
0
0
0
0
1
30
714
0
0
0
0
0
0
0
0
0
0
0
0
0
0
715
0
0
0
0
0
0
0
0
0
0
0
0
0
0
716
0
0
0
0
0
0
0
0
0
0
0
0
0
0
717
0
0
0
0
0
0
0
0
0
0
0
1
0
0
718
0
0
0
0
0
0
0
0
0
0
0
1
0
0
719
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0
0
0
0
0
0
0
0.1
2.3
0.2
0
0
Group B
Backpassage 6
49
430
0
0
0
0
0
0
0
0
0
0
0
0
0
0
431
0
0
0
0
0
0
0
0
0
0
0
0
0
0
432
0
0
0
0
0
0
0
0
0
0
0
0
0
0
433
0
0
0
0
0
0
0
0
0
0
0
0
0
0
434
0
0
0
0
0
0
0
0
0
0
0
0
0
0
435
0
0
0
0
0
0
0
0
0
0
0
0
0
0
436
0
0
0
0
0
0
0
0
0
0
0
0
0
0
437
0
0
0
0
0
0
0
0
0
0
0
0
0
0
438
30
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
3.3
0
0
0
0
0
0
0
0
0
0
0
0
0
100
459
0
0
0
0
0
0
0
0
0
0
0
0
0
0
460
0
0
0
0
0
0
0
0
0
0
0
0
0
0
461
0
0
0
0
0
0
1
1
1
0
0
0
0
0
462
0
0
0
0
1
1
1
1
1
1
1
1
1
1
463
0
0
0
0
0
0
0
0
0
0
0
0
0
0
464
0
0
1
1
1
1
30
465
0
30
Avg.
0
4.3
0.2
0.2
0.3
0.3
5.3
0.4
0.4
0.2
0.2
0.2
0.2
0.2
135
439
0
0
0
0
0
0
0
30
440
0
0
0
0
0
0
0
0
0
0
0
0
0
0
441
0
0
0
0
0
0
0
0
0
0
0
0
0
0
442
0
0
0
1
1
1
1
1
1
1
3
3
3
30
443
0
0
0
0
0
0
0
0
0
0
0
0
0
0
444
0
0
0
0
0
0
1
1
0
0
0
0
0
0
445
0
0
0
0
0
0
0
0
0
0
0
0
0
0
446
0
0
0
0
0
0
0
0
0
0
0
0
0
0
447
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0
0.1
0.1
0.1
0.2
3.6
0.1
0.1
0.4
0.4
0.4
3.8
149
231
0
0
0
0
0
0
0
0
0
0
0
0
0
0
232
0
0
0
0
0
0
0
0
0
0
0
0
0
0
233
0
0
0
0
0
0
30
234
0
0
0
0
0
0
3
1
1
3
1
1
1
1
235
0
0
0
0
0
0
3
2
3
3
0
0
0
0
236
0
0
0
0
0
0
0
0
0
0
0
0
0
0
237
0
0
0
0
0
0
1
1
1
1
1
1
1
1
238
0
0
0
0
0
2
0
0
0
0
0
0
0
0
239
0
0
30
240
30
241
3
30
242
0
0
0
0
0
2
3
3
30
Avg.
2.8
2.7
3
0
0
0.4
4.4
0.9
4.4
1
0.3
0.3
0.3
0.3
Group B
209
448
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Backpassage 6
449
0
0
0
0
0
0
0
0
0
0
0
0
0
0
450
0
0
0
0
0
0
0
0
0
0
0
0
0
0
451
0
0
0
0
0
0
0
0
1
1
1
1
1
1
452
0
0
0
0
0
0
0
0
0
0
0
0
0
0
453
0
0
0
0
0
0
0
0
0
0
0
0
0
0
454
0
0
0
0
0
0
0
0
1
1
1
1
1
1
455
0
0
0
0
0
0
0
0
0
1
1
1
1
1
456
30
457
0
0
0
0
0
0
0
0
2
1
1
1
1
1
458
30
Avg.
5.5
0
0
0
0
0
0
0
0.4
0.4
0.4
0.4
0.4
0.4
212
243
0
0
0
0
0
0
0
0
0
0
0
0
0
0
244
0
0
0
0
0
0
0
0
0
0
0
0
0
0
245
0
0
0
0
3
1
30
246
0
0
0
0
0
0
0
0
0
0
0
0
0
0
247
0
0
0
0
0
2
2
0
0
0
0
0
0
0
248
0
0
0
0
2
0
0
0
0
0
0
0
0
0
249
0
0
0
0
0
0
2
2
0
0
2
0
0
0
250
0
0
0
3
30
426
0
0
0
0
0
0
0
0
0
0
0
0
0
0
427
0
0
0
1
3
1
1
30
428
0
0
0
1
3
3
30
429
0
0
0
0
2
3
3
3
3
3
3
1
30
Avg.
0
0
0
0.4
3.6
0.9
6.2
3.9
0.4
0.4
0.6
0.1
3.8
0
226
Not
Preg.
Group C
Sterile
58
24
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Diluent
25
0
0
0
0
0
0
0
0
0
0
0
0
0
0
46
0
0
0
0
0
0
0
0
0
0
0
0
0
0
47
0
0
0
0
0
0
0
0
0
0
0
0
0
0
48
0
0
0
0
0
0
0
0
0
0
0
0
0
0
49
0
0
0
0
0
0
0
0
0
0
0
0
0
0
50
0
0
0
0
0
0
0
0
0
0
0
0
0
0
51
0
0
0
2
2
1
1
1
30
Avg.
0
0
0
0.3
0.3
0.1
0.1
0.1
3.8
0
0
0
0
0
113
17
30
18
30
19
30
20
30
21
0
30
22
30
23
30
Avg.
25.7
30
117
52
1
0
0
0
0
0
0
0
0
0
0
0
0
0
53
0
0
0
0
0
0
0
0
0
0
0
0
0
0
54
0
0
0
0
0
0
0
0
0
0
0
0
0
0
55
0
0
0
0
0
0
0
0
0
0
0
0
0
0
56
1
0
0
0
30
57
1
0
0
0
0
0
0
0
0
0
0
0
0
0
58
0
0
0
0
0
0
0
0
0
0
0
0
0
0
59
0
0
0
0
0
0
0
0
0
0
0
0
0
0
60
0
0
0
0
0
0
0
0
0
0
0
1
0
0
61
1
0
0
0
0
0
0
0
1
1
1
0
0
0
62
1
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0.5
0
0
0
2.7
0
0
0
0.1
0.1
0.1
0.1
0
0
144
146
0
0
0
0
0
0
0
0
0
0
0
0
0
0
147
0
0
0
0
0
0
0
0
0
0
0
0
0
0
148
0
0
0
0
0
0
0
0
0
0
0
0
0
0
149
0
0
0
0
0
0
0
0
0
0
0
0
0
0
150
0
0
0
0
0
0
0
0
1
0
1
1
1
0
221
0
0
0
0
0
2
2
0
0
0
0
0
0
0
222
0
0
0
0
0
2
2
1
1
1
1
1
0
1
223
0
0
0
0
0
0
0
0
0
0
0
0
0
0
224
0
0
0
0
0
0
0
0
0
0
0
0
0
0
225
0
0
0
0
0
0
0
0
0
0
0
0
0
0
970
0
0
0
0
0
0
0
0
0
0
0
0
0
0
971
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0
0
0
0.3
0.3
0.1
0.2
0.1
0.2
0.2
0.1
0.1
Group C
156
63
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Sterile
64
0
0
1
0
30
Diluent
65
0
0
0
0
0
0
0
1
1
1
1
1
0
0
66
0
0
0
0
1
0
0
0
0
0
0
0
0
0
67
0
0
0
0
1
0
1
1
30
68
0
0
0
0
0
0
0
0
0
0
0
0
0
0
69
0
0
0
0
0
0
0
1
0
0
0
0
0
0
70
0
0
0
0
0
0
0
0
0
0
0
0
0
0
71
0
0
0
0
0
2
2
0
0
0
0
0
1
0
72
0
0
0
0
0
0
0
0
0
0
0
0
0
0
73
0
0
0
0
0
0
0
0
0
0
0
0
0
0
74
0
0
0
0
1
0
0
0
0
0
0
0
0
0
75
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0.1
0
2.5
0.2
0.3
0.3
2.6
0.1
0.1
0.1
0.1
0
166
76
0
0
0
0
0
0
0
0
0
0
0
0
0
0
77
0
0
0
0
0
0
0
0
0
0
0
0
0
0
78
0
0
0
0
0
0
0
0
0
0
0
0
0
0
79
0
0
0
0
0
0
0
0
0
0
0
0
0
0
80
0
0
0
0
0
0
0
0
0
0
0
0
0
0
81
1
0
0
0
0
0
0
0
0
0
0
0
0
0
141
0
0
0
0
0
0
0
0
0
0
0
0
0
0
142
0
0
0
0
0
0
0
0
0
0
0
0
0
0
143
0
0
0
0
0
0
0
0
0
0
0
0
0
0
144
0
0
0
0
0
0
0
0
0
0
0
0
0
0
145
1
30
Avg.
0.2
2.7
0
0
0
0
0
0
0
0
0
0
0
0
Group D
JA-142
2
891
1
3
30
Passage 4
892
1
30
Avg.
1
16.5
30
106
Aborted
NA
159
883
30
884
30
Avg.
30
190
Aborted
NA
206
890
30
Avg.
30
232
888
30
889
30
Avg.
30
234
Aborted
NA
[0068] The farrowing performance results provided the most dramatic differences and similarities between the various treatment groups. Since the treatments would not have an effect on the size of the litters, the most appropriate way to compare the farrowing results would be by using percentage values. Group A had an average percentage of live/born of 85% (SD+/−9.6). Group B had an average percentage of 89% (SD+/−11.6). The control group (group C) had an average percentage of live/born of 83.4% (SD+/−7.9). The average percentages for stillborns for groups A, Band C were 8.8 (SD+/−9.66), 6.6 (SD+/−9.7), and 14 (SD+/−11.39), respectively. The average percentages of mummies born to sows of groups A, B, and C were 6.1 (SD+/−6.01), 3.9 (SD+/−4.45), and 2.6 (SD+/−4.01), respectively. The average percentages of live/born, stillborn and mummies born to the sows of group D were 8.7 (SD+/−8.92), 10.7 (SD+/−11.39), and 81.9 (SD+/−17.18), respectively.
[0069] The results of this example demonstrated the stability of the MSV, JA-142, passage 200 after being passed in the host animal six times. There were no significant differences between the group of sows treated with the MSV (group A) and those sows that were exposed to the Backpassage 6 virus (group B) in the categories of farrowing performance, leukopenia, rectal temperatures, and the clinical observations of either the sows or the piglets. In addition, the results in these same categories for the groups A and B were comparable to those achieved by group C that had been treated with sterile diluent. Finally, the performance of the sows that had been exposed to the virulent parent virus of MSV, JA-142, passage 4, clearly illustrated the level of attenuation of the MSV and the lack of reversion to virulence by the Backpassage 6, JA-142 virus.
Example 4
Materials and Methods
[0070] This example evaluated the safety and level of attenuation of administering a 10× concentration of MSV, JA-142, passage 201. The study was performed on the pregnant sow model and monitored the effect of this dosage on reproductive performance. The study consisted of three groups, A, C, and D. Group A was inoculated intra-nasally with PRRS MSV, JA-142, passage 200. Group C was inoculated intra-nasally with sterile diluent, to act as a normal control group. Group D was inoculated intra-nasally with 10×JA-142, passage 201. All inoculations were given at about 93 days gestation. Body temperatures of the sows were monitored for the first seven days following inoculation (vaccination). Blood samples were collected from the sows once a week and at time of farrowing. Prior to and following inoculation, total white blood cell counts were determined as in Example 2. The health status of each animal was monitored daily for the duration of the study up to and following farrowing for 14 days. Clinical observations of the sows were made from −1 DPV through farrowing. The farrowing performance was evaluated by observing the health status of the piglets born. PRRSV ELISA assays were preformed following the exposures of the sows with the test article. Attempts to isolate PRRSV from serum samples were performed on MA-104 cells following exposure to the test article. Clinical observations of the piglets were made from farrowing until 14 days of age. Blood samples were collected from the piglets at birth, 7 and 14 days of age. PRRSV ELISA assays were performed on the piglet sera weekly following farrowing. Piglets were also weighed at birth, day 7 post farrowing, and at necropsy. At necropsy, the lungs of each piglet were scored for percent lung involvement.
Results and Discussion
[0071] There were no significant differences between groups given a 10× close of MSV, JA-142, passage 201, groups given a regular dose of MSV, JA-142, passage 200, and groups given sterile diluent. Therefore, based on the safety and attenuation of MSV, JA-142, passage 200 and the lack of any significant difference in the results comparing these groups, a 10× dose of MSV, JA-142, passage 201 was shown to be safe, attenuated and effective in inducing antibodies against PRRSV.
Example 5
Materials and Methods
[0072] This example demonstrated that a minimal vaccine close of PRRSV, JA-142, passage 205, representing MSV+5, is efficacious in an experimental respiratory challenge model in feeder pigs. Pigs were divided into three groups. Group 1 was inoculated intramuscularly with PRRS MSV, JA-142, passage 205 at a titer of 2.0 logs/dose. Group 2 was inoculated intramuscularly with sterile diluent. Group 3 acted as normal controls. Pigs from groups 1 and 2 were challenged with a PRRSV isolate with an RFLP pattern of 144 on day 28 post vaccination. Body temperatures of the pigs were monitored for the first seven days following vaccination and daily following challenge. Each animal was weighed at vaccination, challenge, weekly throughout the study, and necropsy. Blood samples were collected weekly following vaccination and every two days following challenge. The health status of each animal was monitored daily for the duration of the study. At necropsy, each animal was sacrificed and the lungs were scored for percent lung involvement as in Example 2. PRRSV ELISA assays were performed following the exposures of the pigs with the test articles and challenge. Following exposure to the test articles, attempts to isolate PRRSV from serum samples were performed on MA-104 cells. Virus isolation and ELISA results were analyzed using a Chi-square analysis which tests whether the percentage of positive animals is the same in each group. White blood cell counts were performed as in Example 2.
Results and Discussion
[0073] Pigs from group 1 (vaccinated pigs) fared better in all aspects of this example than did the pigs from group 2 (pigs given sterile diluent). Clinical scores, rectal temperatures, and percent lung involvement were all higher for the pigs given sterile diluent. Weight gain and white blood cell counts were lower for the pigs receiving the sterile diluent. There was also a significant reduction in viremia beginning on day 4 post-challenge in the group given vaccine. On days 10 and 11 post-challenge, the number of animals positive for viremia decreased further in the vaccinated group, but remained the same in the group receiving sterile diluent.
[0074] An ELISA was used to monitor anti-PRRSV serological status prior to and following vaccination and challenge. All pigs were negative (S/P ratio <0.4) at the time of vaccination. All pigs including the vaccinates were negative at 7 DPV (Days Post Vaccination). Seven days later, 21 of 22 vaccinated pigs were tested as positive for antibody to PRRSV. Two pigs of group 1 remained negative during the pre-challenge period and serological converted at 8 days post challenge (8 DPC). All of the pigs in group 2 were negative at trial day 0 and remained negative throughout the pre-challenge period. On trial day 39 (8 DPC) 17 of the 22 non-vaccinated challenged pigs (Group 2) tested as sero positive. All of the pigs in group 3 (normal controls) remained sero-negative throughout the study.
[0075] Virus isolations from sera were performed before and after vaccination. Of the 22 vaccinated pigs, 17 were positive by 2 DPV, 18 were positive by 4 DPV and 19 were positive by 7 DPV. Following vaccination, vaccine virus was not recovered at all from one pig and not until 0 DPC, for another. These results correspond to the sero-negative status of these pigs during the post vaccination observation period. At the time of challenge, 55% of the vaccinated pigs were viremic positive. Following challenge, this percentage rose to 82% (at 2 DPC) and gradually decreased to 9% on 11 DPC. All pigs in group 2 were negative at 0 DPC and increased to 82% positive at 2 DPC and 91% at 4 DPC. On 6 and 10 DPC, group 2 was approximately 82% virus positive and 73% of this group was positive on 11 DPC. The normal controls, group 3, remained negative for the duration of the study.
[0076] Rectal temperature monitoring showed an overall group increase experienced by group 2. One-half or the pigs in this group experienced a rise of 1° F. over the pre-challenge average for 2 or more days during the 11 day observation period. In comparison, only four of the 22 pigs in the vaccinated group experienced temperatures of 1° F. over their pre-challenge average. The average duration of those animals experiencing elevated temperatures for two or more days was 2.2 days for group 1 and 4 days for group 2. None of the pigs in group 3 experienced increases of 1° F. over their pre-challenge average for two days or longer.
[0077] Weight gain was monitored over the 11 day observation period. Pigs in group 3 gained an average of 1.06 pounds/day, pigs in group 2 gained an average of 0.94 pounds/day and pigs in group 1 gained an average of 0.53 pounds/day. Therefore, non-vaccinated challenged pigs gained only about 57% as much weight as did vaccinated challenged pigs and only 50% as much weight as the control group.
[0078] Leukopenia (white blood cell counts) were monitored during the post challenge observation period. Group 3 experienced a 5% reduction in the group average on trial day 33 (2 DPC) when compared to the pre-challenge average. For group 2, white blood cell counts dropped an average of 41% and did not return to pre-challenge levels until 11 DPC. The vaccinated group experienced a group average drop of 12% on trial day 34 (3 DPC). The counts returned to pre-challenge level on the next day and remained equal to the pre-challenge level for the duration of the observation period.
[0079] Daily clinical observations were made from trial day 28 (−4 DPC) through trial day 42 (11 DPC). All pigs were free of any observable clinical signs during the pre-challenge period. Group 3 remained free of any clinical signs for the duration of the post challenge period. Five of the pigs in group 2 were observed to have post challenge clinical signs. These signs became evident at 6 DPC and were not considered to be severe. The vaccinated pigs had only 1 clinical sign observed during the 11 day post challenge observation period.
[0080] At the termination of the study, lungs were evaluated for observable lung lesions. Group 3 had normal lungs and a group average score of 0.02. The individual pig scores for group 2 ranged from a low of 33 to a high of 98 for a group average of 78.33. The scores or the vaccinated group ranged from 30 to a high of 90 with a group average of 53.20.
[0081] The data in this example demonstrated the efficacy of a modified live Atypical PRRS viral vaccine. The vaccine was administered at a minimal dose of 2.0 logs per close containing the fifth passage beyond the MSV (JA-142, passage 205). Efficacy of the vaccine was demonstrated by significantly reducing the extent of lung lesions, the severity of post challenge leukopenia, and post challenge lever. Additionally, a normal growth rate was maintained in vaccinated/challenged pigs compared to that achieved by the normal control pigs and significantly better than that achieved by non-vaccinated/challenged pigs.
Example 6
Materials and Methods
[0082] This example compared four groups, groups 1, 2, and 3 having twenty pigs each, and group 4 having 10 pigs. Group 1 was inoculated intramuscularly (IM) with PRRS MSV, JA-142, passage 205, at a titer of about 2.5 logs/dose. Group 2 was inoculated intra-nasally with PRRS MSV, JA-142, passage 205, at a titer of about 5.0 logs/dose. Group 3 was inoculated 1M with sterile diluent. Group 4 acted as strict controls. Pigs were challenged with a PRRSV isolate from South Dakota State University (SDSU) with an RFLP pattern of 144 on day 28 post-vaccination. Body temperatures of the pigs were monitored daily following challenge. Each animal was weighed at vaccination, challenge, weekly for the duration of the study, and necropsy. Blood samples were collected weekly following vaccination and every two days following challenge. The health status of each animal was monitored daily for the duration of the study. At the termination of the study, animals were sacrificed and their lungs scored for percent lung involvement.
[0083] PPRSV ELISA assays were performed following the exposures of the pigs with the test articles and challenge. Attempts to isolate PRRSV from serum samples were also performed on MA-104 cells following exposure to the test articles. WBC counts and clinical observations were determined post inoculation as in Example 2.
Results and Discussion
[0084] At zero days post vaccination (DPV), all pigs in this example were serologically negative to PRRSV as indicated by having a S/P ratio <0.4. At 14 DPV, 70% of the pigs in group 1 and 95% of the pigs in group 2 tested positive for the presence of anti-PRRSV antibody. Only one vaccinated pig of group 1, remained sero-negative throughout the pre-challenge period. This pig became sero-positive at seven days post challenge (DPC). All of the pigs in groups 3 and 4 remained negative throughout the pre-challenge period. At nine DPC, all of the pigs in group 3, the sterile diluent treated group, tested positive by ELISA for PRRSV antibody. The normal controls, group 4, remained negative for the duration of the study.
[0085] The virus isolation results correlated well with serological results. Only one pig remained negative for virus isolation from serum and this corresponded to the sero-negative status during the post vaccination period. These results indicate a relationship between post vaccination viremia and serological conversion with vaccine dosage. Group 2 was 100% sero-positive at 14 DPV as compared to 70% for group 1. The high dose group (group 2) was 85% and 90% viremia positive at 14 and 21 DPV, respectively. In comparison, the low dose group (group 1) was 55% and 85% positive for the same test days.
[0086] Following challenge, 89% of the animals in group 3 experienced temperatures that were one degree F. or greater than the pre-challenge values for two or more days. In group 1, 75% of the animals experienced temperatures or one degree or greater for two or more days. While only 45% of the animals of group 2 experienced elevated temperatures. In comparison, 30% of the animals in the normal control group (group 4) experienced elevated temperatures for two or more days during the 11 day observation period.
[0087] Treatment with either the high vaccine dose or the low vaccine dose appeared to have no detrimental effect on the growth performance during the post-vaccination period (−3 DPV to 28 DPV). The average daily weight gain for groups 1 and 2 was 0.77 lbs./day and 0.76 lbs./day, respectively. For comparison, groups 3 and 4 had average daily weight gains of 0.77 lbs. and 0.78 lbs., respectively. Following challenge, the vaccinated groups outperformed the sterile diluent group by 0.05 lbs./day (group 1) and 0.15 lbs./day (group 2). The normal controls outgained the vaccinates during the same time period by an average of 0.4 to 0.5 lbs./day.
[0088] Eighty-four percent (16 of 19) of group 3, the sterile diluent treatment group, experienced a 25% or greater drop in their WBC count for one or more days after challenge. The normal controls had 3 of 10 (30%) that had experienced similar decreases. Following challenge, the vaccinated groups, the low close (group 1) and the high dose (group 2) had 11 of 20 (55%) and 3 of 20 (15%) experiencing leukopenia of 25% for one or more days.
[0089] The clinical observations made prior to the challenge indicated that the pigs were of good health status. Following challenge, the level of health status did not significantly change for those pigs that were challenged (groups 1, 2, & 3). Lethargy, respiratory signs, and lost appetite were the clinical signs observed and these were described as mild in severity. The clinical signs reported for one pig in group 2 could be attributed to the bacterial pneumonia (see discussion below on lung lesions) that it was experiencing. The normal control group (group 4) was free of any observable clinical signs during the 11 day observation period.
[0090] At the termination of the study, pigs were sacrificed and the lungs were observed for PRRS-like lesions to score the extent of lung involvement. The percent of involvement was scored for each lobe then multiplied by the percent the lung represented for the total lung capacity. For example, 50% lung involvement for a diaphragmatic lobe was then multiplied by 25% to equal 12.5% of the total lung capacity. The maximum score that could be obtained was 100. The group average lung score for the normal controls (group 4) was zero. The group average score for the sterile diluent treatment group (group 3) was 70.08. The vaccinated treatment groups average scores were 48.83 for the low dose (group 1) and 17.76 for the high dose (group 2). One pig was observed to have a lung score of 62.5, the highest score within group 2. The lesions noted on this pig's lungs were described to be associated with bacterial pneumonia.
[0091] From the results of this study, both dosage levels of the atypical PRRS MSV vaccine reduced the severity of the clinical signs associated with the respiratory disease caused by the PRRSV. A full field dose outperformed the minimal dose as indicated by the significant reduction in lung lesion scores.
Example 7
Materials and Methods
[0092] This example determined the sequence of the attenuated MSV, JA-142 from the 201st passage as well as the sequence of passage 3 of the field isolate virus, JA-142. The attenuated virus isolate was obtained from the master seed stock representing the 201st passage in MA-104 simian cells of a PRRSV isolated from swine affected with PRRS.
[0093] The virus was grown on 2621 cells, a monkey kidney cell line, also referred to as MA-104 and as USU-104 (Gravel) et al., 181 Proc. Soc. Exp. Biol. Med. 112-119 (1986), Collins et al., Isolation of Swine Infertility and Respiratory Syndrome Virus (Isolate ATCC VR-2332) in North America and Experimental Reproduction of the Disease in Gnotobiotic Pigs, 4 J. Vet. Diagn. Invest. 117-126 (1992)) (the teachings of which are hereby incorporated by reference). Cells were cultured in 50 ml Dulbecco modified Eagle's MEM medium (Life Technologies, Inc., Gaithersburg, Md.), supplemented with 10% fetal calf serum and 50 gentamicin (Sigma Chemical Co., St. Louis, Mo.) in a 5% humidified CO, atmosphere at 37° C. in 75 cm 2 plastic tissue culture flasks. Cells were maintained by passage at 5-7 day intervals. Cells were dislodged from the surface with trypsin-versene and split 1:4. To infect cells, media was decanted and 1 ml of cell supernatant containing virus at a titer of approximately 10 5 -10 6 tissue culture infective doses (TCID 50 ) was added for 30 min. Thirty ml fresh media containing 4% fetal calf serum was added. Cells were incubated as described above for 5 days, at which time cytopathic effect was evident in the culture. Culture medium containing virus was centrifuged at 2000 rpm in a Beckman TJ6 centrifuge to pellet cellular debris.
[0094] Viral genomic RNA was purified by adding 1120 μl of prepared Buffer AVL (QIAamp Viral RNA Isolation Kit, Qiagen) (QIAGEN, inc. Valencia, Calif.)/carrier RNA to a 280 μl sample of virus-containing culture medium. The mixture was vortexed and incubated at room temperature for 10 min. 1120 μl ethanol was added and the mixture was inverted several times. RNA was absorbed to the matrix of a QIAamp spin column by repeated centrifugation of 630 μl aliquots at 6,000×g for 1 min. The column was washed with 500 μl buffer AW and centrifuged to remove all traces of wash solution. RNA was eluted from the column with 60 μl of diethylpyrocarbonate-treated water at room temperature. Purified RNA was stored at −70° C. or used immediately for synthesis of cDNA.
[0095] For cDNA synthesis, viral RNA was heated at 67° C. for 7 min, primed with random hexamers or PRRSV-specific primers, and reverse transcribed with Superscript II RNase H − reverse transcriptase (RT) (Life Technologies, Inc.). Reactions contained 5 mM MgCl 2 , 1× standard buffer II (Perkin Elmer Corp. Wellesley, Mass.), 1 mM each of dATP, dCTP, dGTP and dTTP, 1 unit/μl of RNase inhibitor, 2 units of RT, and 1 μl of RNA in a 40 μl reaction. Reaction mixtures were incubated for 15 min at 42° C., for 5 min at 99° C. and for 5 min at 5° C.
[0096] Polymerase chain reaction (PCR) was performed to obtained DNA fragments for sequencing as follows: 10 μl portions of cDNA reaction mixture were combined with the following reagents, resulting in a 25 μl reaction containing 2 mM MgCl 2 , 1× standard buffer II (Perkin Elmer), 0.2 mM each of dATP, dCTP, dGTP and dTTP, 0.3 μM of 5′- and 3′-PRRSV-specific primer, and 0.375 units AmpliTaq Taq polymerase (Perkin Elmer). Reactions were prepared by heating for 4 min at 93° C. in a thermal cycler, then 35 cycles consisting of 50-59° C. for 30 sec, 72° C. for 30-60 sec, and 94° C. for 30 sec. Specific times and temperatures varied depending on the annealing temperatures of the primers in each reaction and the predicted length of the amplification product. A final incubation was performed for 10 min at 72° C. and reactions were placed at 4° C. PCR products were purified with a Microcon 100 kit (Amicon, Bedford, Mass.).
[0097] Rapid amplification of cDNA ends (RACE) PCR was performed to obtain the extreme 5′-end sequence of the genomic RNA, based on the method of Frohman, Mass., On Beyond Classic RACE (Rapid Amplification of cDNA Ends), 4 PCR Methods and Applications S40-S58 (1994) (the teachings of which are hereby incorporated by reference). Viral RNA was isolated and converted to cDNA as described above, with random hexamers as primers. Reaction products were purified on a Microcon 100 column (Amicon). A poly(dA) tail was added to the 3′-end by incubating 10 μl of cDNA in a 20 μl volume containing 1× buffer 4 (New England Biolabs, Beverly, Mass.), 2.5 mM CoCl 2 , 0.5 mM dATP and 2 units terminal transferase (New England Biolabs), for 15 min at 37° C. The reaction was stopped by heating for 5 min at 65° C. and then was diluted to 200 μl with water.
[0098] PCR was performed using the Expand a Long Template PCR System (Boehringer Mannheim, Mannheim, Germany) in a 50 μl reaction volume containing 10 μl of diluted, poly(dA)-tai led cDNA, 1× buffer 3, 0.35 mM each dATP, dCTP, dGTP and dTTP, 0.625 mM MgCl 2 , 0.04 μM Q t primer (Frohman, 1994), 0.3 μM Q o primer (Frohman, 1994), 0.3 μM 5′-CGCCCTAATTGAATAGGTGAC-3′ and 0.75 μl of enzyme mix. Reactions were heated at 93° C. for 2 min in a thermal cycler and cycled 25 times with each cycle consisting of 93° C. for 10 see, 63° C. for 30 sec, and 68° C. for 12 min. After 25 cycles, the reaction was incubated at 68° C. for 7 min and held at 4° C. An aliquot of the reaction was diluted 100-fold and 5 μl or diluted product was added to a second PCR reaction containing, in 50 μl, 1× buffer 1, 0.35 mM each of dATP, dCTP, dGTP and dTTP, 0.3 μM primer Qi (Frohman, 1994), 0.3 μM 5′-CCTTCGGCAGGCGGGGAGTAGTGTTTGAGGTGCTCAGC-3′, and 0.75 μl enzyme mix. Reactions were heated at 93° C. for 2 min in a thermal cycler and cycled 25 times with each cycle consisting of 93° C. for 10 sec, 63° C. for 30 sec, and 68° C. for 4 min. After 25 cycles, the reaction was incubated at 68° C. for 7 min and held at 4° C. Reaction products were electrophoresed on a 1% agarose gel and the band of approximately 1500 by was purified using the QIAgen QXII gel purification kit. Eluted DNA was cloned into the pGEM-T vector (Promega, Madison, Wis.) using standard procedures. Individual clones were isolated and grown for isolation of plasmid DNA using QIAgen plasmid isolation kits.
[0099] PCR products and plasmid DNA were combined with appropriate primers based on related PRRSV sequences in Genbank or derived from known sequences, and subjected to automated sequencing reactions with Taq DyeDeoxy terminator cycle sequencing kits (Applied Biosystems, Foster City, Calif.) and a PR 2400 Thermocycler (Perkin Elmer) at the University of Minnesota Advanced Genetic Analysis Center. Reactions were electrophoresed on an Applied Biosystems 3700 DNA sequencer. Sequence base calling and proofreading were performed primarily with the Phred program (University of Washington Genome Center) and fragment assembly was performed primarily with the Phrap program (University of Washington Genome Center). Additional computer software including the Lasergene Package (DNASTAR Inc., Madison, Wis.), Wisconsin package version 9.1 (Genetics Computer Group, Madison, Wis.), and EuGene (Molecular Biology Information Resource, Houston, Tex.) was used to analyze the sequence. The final viral genomic sequence was assembled from approximately 100 PCR reactions and 428 DNA sequencing reactions.
Results
[0100] The results of Example 7 are given as SEQ ID Nos. 1 and 2 wherein SEQ ID No. 1 represents the DNA sequence of the 201st passage of the Master Seed Virus, JA 142 and SEQ ID No. 2 represents the DNA sequence of the field-isolated virulent virus. JA 142 after three passages. Additionally, RNA sequences of the 201st passage JA-142 and the field isolated virulent virus, JA-142 are provided as SEQ ID Nos. 3 and 4, respectively. These RNA sequences vary slightly from the DNA sequences at the 5′ end of the genome.
Example 8
Materials and Methods
[0101] This example demonstrated the presence or absence of a NspI restriction endonuclease site for differentiation between field strains of PRRSV and an attenuated strain of PRRSV. Thus, this example provides a diagnostic testing method using restriction fragment length polymorphism (RFLP) analysis. RFLP is useful as a diagnostic tool because the NspI site is present in most field strains of PRRSV. Samples, preferably of scrum, should be gathered from a suspected infected individual for RT-PCR/RFLP based diagnostic testing. In this case, known virulent field strains were used for testing to provide known result standards for later diagnostic testing. While Qiagen products and specific method steps are disclosed, it is understood that other methods and products known in the art can be utilized.
[0102] For performance of the diagnostic test (and to obtain the standards disclosed below) viral genomic RNA was isolated using a QIAamp Viral RNA Isolation Kit (Qiagen, Inc. Valencia, Calif.) and following the mini spin protocol. The following steps were used:
1. Carrier RNA was added to Buffer AVL and placed at 80° C.′ for five minutes or until dissolution of the precipitate to form solution 1. Do not heat Buffer AVL over 5 minutes or more than 6 times. Frequent warming/extended incubation will cause degradation of carrier-RNA, leading to reduced recovery of Viral RNA and eventually false negative RT-PCR results. 2. 1120 μl of solution 1 was pipetted into a microfuge tube. 3. 280 μl of scrum sample was added to the microfuge tube holding solution 1 and the resulting mixture was vortexed thoroughly to ensure that solution 1 and the sample were well mixed together. This is done to lyse the sample under highly denaturing conditions, inactivate RNases, and ensure isolation of intact viral RNA. Carrier-RNA improves binding of viral RNA to the QIAamp membrane, and limits possible degradation of the viral RNA due to any residual RNase activity. 4. This mixture was incubated at room temperature for 10 minutes. Viral particle lysis is substantially complete after lysis for 10 minutes at room temperature, although longer times may be used with little or no effect on the yield or quality of the purified RNA. 5. 1120 μl of ethanol (EtOH) (96-100%) was added to the incubated mixture and mixed thoroughly by inverting the tube several times. 6. A QIAamp spin column was placed in a 2 ml collection tube and 630 μl of the mixture obtained in step five was added. This mixture was then centrifuged at 6000×g for one minute. 7. The filtrate in the collection tube was discarded. 8. The QIAamp spin column was placed into a clean 2 ml collection tube and another 630 μl of the mixture obtained in step five was added to the spin column and centrifuged at 6000×g. 9. The filtrate in the collection tube was discarded. 10. The QIAamp spin column was placed into a clean 2 ml collection tube and another 630 μl of the mixture obtained in step five was added to the spin column and centrifuged at 6000×g. 11. 500 μl of Buffer AW1 was added to the spin column and centrifuged at 6000×g for one minute. 12. The tube containing the filtrate was discarded. 13. The spin column was placed into a clean 2 ml collection tube and 500 μl of Buffer AW2 was added and centrifuged at 18,500×g for three minutes. The filtrate was discarded. 14. The spin column was placed into a new 2 ml collection tube and centrifuged at 6000×g for one minute to remove the last traces of AW2. The filtrate was discarded. 15. The spin column was placed into a clean 1.5 ml microcentrifuge tube and 60 μl Buffer AVE at room temperature. This mixture was incubated for one minute at room temperature before being centrifuged at 6000×g for one minute to elute the RNA. 16. The eluted RNA was pipetted into a 1.5 ml microfuge tube and stored at −70° C. if the RT-PCR is not able to be done immediately.
[0119] RT-PCR was performed on the eluted RNA obtained in the above method. A 20 μl “master mix” containing the following: 5 μl of 1×RT-PCR buffer, 1 μl of 0.4 mM DNTP mixture (containing equal amounts each of dATP, dCTP, dGTP and dUTP), 0.1 μl of 0.08 units/Rx RNAse inhibitor, 0.5 μl 500 nM BVDV forward primer, 0.5 μl 500 nM BVDV reverse primer, 11.9 μl RNAse/DNAse free water, and 1 μl Qiagen “secret” enzyme mix was added to a tube. 5 μl of the eluted RNA was then added to the tube.
[0120] Reactions were initially heated at 50° C. for 30 minutes followed by heating at 95° C. for 15 minutes in a thermal cycler and then cycled 35 times with each cycle consisting of 57° C. for 30 seconds, 72° C. for 45 seconds, and 94° C. for 45 seconds. After 35 cycles, the reaction was incubated at 57° C. for 30 seconds followed by 72° C. for 7 minutes and finally held at 4° C. To check the PCR on an agarose gel, 1 g of agarose was added to 100 ml of 1×TAE buffer before microwaving on high for two minutes. Next, 4 μl of 10 mg/ml EtBr was added to the heated gel before casting the gel and allowing it to solidify for 15-30 minutes. 4 μl of the PCR product was mixed with 1 μl loading dye. 3.5 μl of a 1 Kb ladder was added to 13.2 μl of water and 3.3 μl of loading dye for use as a marker. 4 μl of the marker mixture was electrophoresed on the gel, indicating a 1 Kb product. A band from the PCR product should be approximately 1 Kb in size. The gel was then run at 140 volts for 1 hour or 75 volts for two hours.
[0121] The band of approximately 1 Kb was purified using the QIAgen Qiaquick PCR Purification Kit (Qiagen, Inc. Valencia, Calif.). A column was placed in a collection tube and 20 μl PCR reaction sample and 100 μl PB buffer were added. This mixture was mixed thoroughly before spinning for 1 minute at full speed in an Eppendorf microfuge. The flow-through products were discarded and the column was replaced in the tube. The tube was spun for another full minute and allowed to stand for at least one minute at room temperature. The column was then spun a third time at lull speed. The eluent remaining contains purified PCR product and water.
[0122] The PCR/water product from above was then digested with Nsp I, a restriction enzyme and then electrophoresed on a 1.5% agarose gel to determine fragment numbers and lengths.
Results
[0123] The results of Example 8 are used for diagnostic results. It was found that most of the field strains for the PRRS virus contain one Nsp I restriction site, therefore yielding digestion products of 549 and 476 by from the 1 Kb RT-PCR product. The parent strain of the JA-142 passage 200 possesses this phenotype. Only one PRRS strain, BI-Vetmedica 142 passage 200 (±5), contains two Nsp I sites, yielding digestion products of 476, 380, and 173 by from the 1 Kb RT-PCR product. Some field strains possess no Nsp I site within this RT-PCR product, and therefore exhibit no digestion and electrophoresis of one fragment of 1021 bp. Thus, the presence of the attenuated virus can be determined.
Example 9
Materials and Methods
[0124] This Example tested the degree of protective immunity against maternal reproductive failure of swine vaccinated by one or two attenuated strains of PRRSV.
[0125] Fifty gilts were separated into live experimental groups designated A-E and having ten gilts in each group. Gilts of group A were neither vaccinated nor challenged and were therefore used as strict controls. Gilts of group B were used as the challenge controls and therefore received no vaccinations but were challenged at or about day 90 of gestation. Gilts of groups C, D, and E were each vaccinated twice before conception with one month between vaccinations. These gilts were then challenged at or about day 90 of gestation. Two strains of vaccine virus (strains RespPRRS/Repro and JA-142) were used to challenge the gilts. The challenge consisted of oronasal exposure to virulent PRRSV. Gilts of group C were vaccinated twice with strain RespPRRS/Repro. Gilts of group D were vaccinated first with RespPRRS/Repro and then with JA-142. Gilts of group E were vaccinated twice with strain JA-142. Gilts and their progeny were observed at least twice daily for clinical signs and tested for both PRRSV and homologous antibody at selected intervals. The gilts of groups C, D, and E were bled just before their first vaccination and at selected times thereafter until they were necropsied, usually at or about 14 days after farrowing or sooner if they aborted. Gilts of group A and B were bled just before challenge and at identical selected times thereafter. Beginning one month after the second vaccination of groups C, D, and E, all gilts were bred as they came into estrus. All of the boars used for breeding purposes were free of antibody against PRRSV. Near the time of challenge, each gilt was moved to an isolation room and was kept in isolation until the experiment was ended for that gilt and her litter at two weeks after farrowing or sooner in the case of abortion or premature death of all progeny. All surviving pigs were weighed when they were two weeks old. Gilts that failed to conceive at their first, second, or third estrocycle were excluded from the experiment. This reduced the numbers of pregnant gilts for groups B, C, D, and E to 9, 8, 9, and 9, respectively. The same limitation did not apply to group A because for this group, there were more than ten nonvaccinated gilts available from which to make a random selection for inclusion in group A.
Results and Discussion:
[0126] All vaccinated gilts (groups C, D, and E) responded to vaccination with the production of antibodies against PRRSV. These results are provided in FIG. 1 which is a graph representing the ratio of the total number of samples to samples positive for PRRSV antibodies. Blood samples were collected from the gilts just before their first vaccination and at selected times thereafter during an interval of 196 days. Depending on when gilts conceived (breeding was started on day 60), they were progressively removed from this group. Beginning at or about 90 days of gestation, blood samples were collected just before they were challenged, seven days after challenge, fourteen days after challenge, at the time of delivery (which was at or about 24 days after challenge if the gilt farrowed normally, or sooner if the gilt aborted), and at the time of necropsy (which was at or about 38 days, i.e. 2 weeks after farrowing, or sooner if the gilt lost all of her live born pigs before 2 weeks after farrowing). These results are provided in FIG. 2 .
[0127] As shown in FIGS. 1 and 2 , antibody levels increased after challenge for groups B, C, D, and E. For group B, the nonvaccinated group, these antibodies appeared only after challenge while they were present prior to challenge for groups C, D, and E. Gilts of group A and all boars used for breeding both vaccinated and nonvaccinated gilts remained free of antibody against PRRSV throughout the experiment. None of the vaccinated gilts had any obvious vaccine-related clinical signs after vaccination. Conversely, all of the gilts (both vaccinated and nonvaccinated) had moderate to severe clinical signs following challenge. A summary of the number of live born and still born pigs, the number of aborted, late term dead, and mummified fetuses, and the number and weight of pigs still alive 14 days after farrowing is presented in Table 4. All of the pigs of groups C, D, and E that survived through day 14 were robust and were judged to be in excellent health. None of these pigs yielded infectious virus from either serum or lung lavage samples. In contrast, all pigs of group B that survived through day 14 were unthrifty and were shown by virus isolation to be infected. A measure of the difference in general health is provided by the relative body weights of pigs of group B versus those of pigs of groups A, C, D, and E. The appearance of pigs of group B suggested that few, if any, would have recovered or would have recovered sufficiently to warrant any expectation of their continued survival under conditions of commercial swine production.
[0000]
TABLE 4
Effect of Vaccination Against Porcine Reproductive and Respiratory Syndrome Virus
(PRRSV) on the Health and Survival of Fetuses and Pigs of Gilts Subsequently
Exposed to Highly Virulent PRRSV
Day 0 1
Day 14 2
Late-
Mean
term
Mean pig
litter
Liveborn
Stillborn
dead
Mummified
Aborted
Live
weight
weight
Group
Gilts 3
pigs
pigs
fetuses
fetuses
fetuses
pigs
(lbs)
(lbs)
A
10
102
17
1
2
0
95
9.8
93.1
B
9
24
3
62
5
0
16
5.6
10.0
C
8
37
8
31
4
13
27
11.1
37.5
D
9
47
10
14
0
39
38
8.7
36.7
E
9
50
13
38
3
0
33
10.4
38.1
1 At the time of farrowing.
2 On the day the experiment was ended.
3 Pregnant gilts that aborted or farrowed.
[0128] Vaccination with either strain (RespPRRS/Repro and JA-142) of attenuated PRRSV provided a level of protective immunity that was demonstrated by challenge exposure. Although protection was incomplete regardless of the vaccine strain or method of vaccination, it was sufficient to recommend vaccination as an economically beneficial procedure. Whereas the loss of pigs of group B was essentially complete either due to death or ill health, about 40% of the pigs of litters of groups C, D, and E (on a per litter basis and using 100% as the value for litters of group A) would have survived to market. The excellent health status of the surviving pigs of groups C, D, and E is emphasized by the fact that the mean body weight of pigs of these groups (when calculated collectively) is the same as that of pigs of group A. The economic impact of saving about 3.6 pigs/litter through vaccination is difficult to project with certainty, however, if a reasonable assumption is made that each pig is worth about $20.00 in profit and reduced overhead through sharing of fixed costs, then two vaccinations at an estimated cost of about $1.00 each would return $72.00 for each $2.00 invested. On the basis of these assumptions, anything more than a prevalence of PRRSV-induced reproductive failure of one case for every 36 pregnancies (or a severe clinical epidemic once every 18 months assuming 2 pregnancies/year) would make vaccination cost effective. Moreover, it seems likely that the results of this study present the worst case scenario. Namely, the strain used for challenge was selected to represent the most virulent field strains of PRRSV currently present in North America and may not accurately reflect the majority of field strains against which vaccines are likely to be more protective. | Substantially avirulent forms of atypical porcine reproductive and respiratory syndrome (PRRS) virus and corresponding vaccines are provided which result from cell culture passaging of virulent forms of PRRS. The resultant avirulent atypical PRRS virus is useful as a vaccine in that PRRS specific antibody response is elicited by inoculation of host animals, thereby conferring effective immunity against both previously known strains of PRRS virus and newly isolated atypical PRRS virus strains. The preferred passaging technique ensures that the virus remains in a logarithmic growth phase substantially throughout the process, which minimizes the time required to achieve attenuation. The present invention also provides diagnostic testing methods which can differentiate between animals infected with field strains and attenuated strains of PRRSV. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of PCT Patent Application PCT/EP2008/003058 entitled “COUPLING ARRANGEMENT” and filed on Apr. 17, 2008, which claims benefit of German Patent Application 10 2007 019 604.2 filed on Apr. 24, 2007.
BACKGROUND OF INVENTION
[0002] 1. Field of Invention
[0003] The invention relates to a clutch arrangement.
[0004] 2. Description of Related Art
[0005] Single and multiple clutch arrangements having a housing-fixed component, having one or more hollow cylindrical pistons which are arranged so as to be rotatable about a rotational axis relative to the housing-fixed component, and having a rotatable component or component which can be set in rotation which is formed, relative to the housing-fixed component, as a component which is arranged around the rotational axis, which rotatable component or component which can be set in rotation has a hollow cylindrical chamber, or in the case of a plurality of pistons a plurality of hollow cylindrical chambers, at the end side of the piston(s), are generally known. Furthermore, the clutch arrangement has at least one line arrangement which, for a pressure medium in the form of hydraulic oil, forms a communication line through the housing-fixed component and through the rotatable component to the chamber. A rotary leadthrough seal serves to seal off the line arrangement between the housing-fixed component and the rotatable component.
[0006] A disadvantage of such arrangements is that, with increasing rotational speed of the rotatable component in the chambers, greater centrifugal forces act on the hydraulic oil present in the chambers. A centrifugal-force-dependent or rotational-speed-dependent pressure is generated in the chambers. If the pressure becomes too high, this can lead to an undesired closure of the clutch. To compensate this, provision is made of devices or controllers for centrifugal force compensation. A disadvantage, therefore, in particular in hydraulically directly actuated clutches, is a centrifugal force pressure which builds up in the rotating pressure piston and which, in the case of normally open clutches, can lead to an automatic closure of the clutch as a function of rotational speed, and therefore centrifugal force compensating pistons must be used.
[0007] It is the object of the invention to propose a clutch arrangement which makes centrifugal force compensation superfluous, or necessary only to a reduced extent.
SUMMARY OF INVENTION
[0008] The present invention overcomes the disadvantages in the related art in a clutch arrangement that has a housing-fixed component. A piston is arranged so as to be rotatable about a rotational axis relative to the housing-fixed component. A rotatable component, relative to the housing-fixed component, is arranged around the rotational axis and has a chamber in an end-side region of the piston. A line arrangement, for a pressure medium, forms a communication line through the housing-fixed component and rotatable component to the chamber. Proceeding from the rotational axis, a radial inside distance and/or a radial outside distance of the piston is smaller than a radial seal distance of a rotary leadthrough seal.
[0009] In particular, a rotary leadthrough seal seals off the line arrangement between the housing-fixed component and the rotatable component. Particularly preferable here is an arrangement in which, proceeding from the rotational axis, a radial outside distance of the piston is smaller than a radial seal distance of the rotary leadthrough seal.
[0010] A ratio [(r 0 -ri)/(ra-r 0 )] of firstly the radial inside distance ri of the piston and of secondly the radial outside distance ra of the piston to the radial seal distance r 0 is preferably dimensioned such that, at a predetermined rotational speed of the rotatable component, a pressure acting on the piston does not actuate the piston. The predetermined rotational speed preferably corresponds to a predefined rated rotational speed, in particular a maximum rotational speed, of a drive, which is assigned to the other components, during operation.
[0011] The rotatable component preferably has a piston seal or forms a piston seal. The line arrangement advantageously forms a communication line also to at least one further chamber for a further piston, wherein it is preferably also the case that, proceeding from the rotational axis, a radial inside distance of the further piston, too, is smaller than the radial seal distance of the rotary leadthrough seal.
[0012] Provision may be made of an additional device and/or controller for centrifugal force compensation which permits centrifugal force compensation in particular in only an upper rotational speed range of the rotatable component. This makes it possible for the device and/or controller for centrifugal force compensation for only high rotational speed ranges of the drive to be of smaller dimensions.
[0013] Other objects, features, and advantages of the present invention will be readily appreciated as the same becomes better understood while reading the subsequent description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF EACH FIGURE OF DRAWING
[0014] An exemplary embodiment of the present invention is explained in more detail below on the basis of the drawing. Identical reference symbols used in the various figures of the drawing denote identical or equivalent components and/or functions and are preferably explained in more detail only on the basis of one of the figures. In the drawing:
[0015] FIG. 1 schematically shows an arrangement principle of components of a clutch and a diagram illustrating pressure conditions in a chamber of the clutch;
[0016] FIG. 2 shows a sectional view through an exemplary dual clutch for implementing the functional principle from FIG. 1 ; and
[0017] FIG. 3 shows a further exemplary clutch arrangement.
DETAILED DESCRIPTION OF INVENTION
[0018] As is schematically shown in FIG. 1 , a clutch arrangement for forming a single clutch or multiple clutch has a housing-fixed component 6 . Arranged within the housing-fixed component 6 is a rotatable component 1 which may if appropriate also be of multi-part design and which can be set in rotation about a rotational axis ω by means of a drive device such as a motor. For the actuation of the clutch, the clutch arrangement has at least one cylinder-piston arrangement with a piston 2 which is of annular or substantially hollow cylindrical design at least at the end side, with the piston 2 being arranged so as to be rotatable about the rotational axis ω relative to the housing-fixed component 6 . The piston 2 is in particular of cylindrical design. For the actuation of the piston 2 , the rotatable component 1 has an annular or hollow cylindrical chamber 8 which faces toward the end side of the piston 2 and which holds the piston 2 . The rotatable component 1 is therefore formed as a component which is arranged, relative to the housing-fixed component 6 , around the rotational axis ω, which rotatable component 1 has a chamber 8 in the end-side region of the piston 2 . As shown in the diagram, the rotatable component 1 may be formed as a piston seal or have a piston seal.
[0019] For the actuation of the piston 2 , that is to say for the exertion of a force F on the end side of the piston 2 , a line arrangement leads to the chamber 8 in order to conduct a pressure medium, usually hydraulic oil, into or out of the chamber 8 . Since a pump for pumping the pressure medium is expediently arranged in a housing-fixed manner relative to the housing-fixed component but the chamber 8 is formed within the rotatable component 1 , a first section of the line arrangement 4 leads through the housing-fixed component 6 and a second section of the line arrangement 4 leads through the rotatable component 1 to the chamber 8 . In this way, the line arrangement forms a communication line for the pressure medium, which communication line leads through both the housing-fixed component 6 and also the rotatable component 1 .
[0020] One or two rotary leadthrough seals 3 are arranged in the transition region between the housing-fixed component 6 and the rotatable component 1 , which rotary leadthrough seals 3 seal off the line arrangement 4 with respect to a gap 9 between the housing-fixed component 6 and the rotatable component 1 . Continuous pressurization of the second, rotatable section of the line arrangement 4 is possible by virtue of an encircling groove being formed in the housing-fixed component 6 and/or in the rotatable component 1 in the transition region to the housing-fixed component 6 , such that the line arrangement 4 forms an open communication line for the pressure medium preferably in every rotational position of the rotatable component 1 .
[0021] To eliminate or reduce the requirement for centrifugal force compensation, the components are dimensioned in an advantageous manner in the radial direction proceeding from the rotational axis ω. As can be seen from FIG. 1 , proceeding from the rotational axis ω, a radial inside distance ri of the piston 2 is smaller than a radial seal distance r 0 of the rotary leadthrough seal 3 . This has the effect, during a rotation, that a vacuum is generated relative to the radial seal distance if) in that section of the chamber 8 which faces toward the rotational axis ω.
[0022] In the illustrated embodiment, proceeding from the rotational axis ω, a radial outside distance ra of the piston 2 is advantageously greater than the radial seal distance r 0 of the rotary leadthrough seal 3 . This has the effect that, in the conventional way, an overpressure is generated relative to the radial seal distance r 0 in the outer section of the chamber 8 during a rotation. In special embodiments, proceeding from the rotational axis ω, the radial outside distance ra of the piston 2 may however also be smaller than the radial seal distance r 0 of the rotary leadthrough seal 3 .
[0023] It is therefore advantageously possible, by means of a suitable selection of the radial inside distance ri of the piston 2 , of the radial outside distance ra of the piston 2 and of the radial seal distance r 0 of the rotary leadthrough seal 3 , to predefine a rotational-speed-dependent pressure p in the chamber 8 . The dimensioning is carried out such that, for a typical predetermined rotational speed, centrifugal force compensation is preferably not required, or is required only to a reduced extent, at the predetermined rotational speed. For this purpose, the ratio [(r 0 -ri)/(ra-r 0 )] of firstly the radial inside distance ri of the piston 2 and of secondly the radial outside distance ra of the piston 2 to the radial seal distance r 0 for the predetermined rotational speed of the rotatable component is dimensioned such that a force F acting on the piston 2 , or an overall pressure p acting in the chamber 8 , does not actuate the piston 2 even without additional centrifugal force compensation. This means that the force acting on the overall piston surface is, in total, zero.
[0024] In addition to the advantageous possibility of defining a typical and common rotational speed as the predetermined rotational speed, it is also possible for a maximum rotational speed of the drive to be used as the predetermined rotational speed. In the event of pressure compensation being provided below the maximum rotational speed, provision is preferably made of a device and/or controller for centrifugal force compensation as an additional element in the conventional way, with such a device and/or controller for centrifugal force compensation being dimensioned so as to activate centrifugal force compensation in only a predetermined upper rotational speed range of the rotatable component 1 . In this way, it is possible to provide a centrifugal force compensation arrangement which is of smaller dimensions and which is activated only in an optional manner, with centrifugal force compensation being activated at the maximum rotational speed, which is encountered only rarely.
[0025] As is also shown by means of the diagram in FIG. 1 , a pressure p=p(r), which is dependent on diameter and on rotational speed, is generated in the chamber 8 during a rotation of the rotatable component 1 . In the regions between the radial inside distance ri of the piston 2 and the radial seal distance r 0 , the pressure p(r)<p 0 is lower than the pressure p(r 0 )=p 0 which is generated at the radial seal distance r 0 . In regions between the radial seal distance r 0 and the radial outside distance ra of the piston 2 , the pressure p(r)>p 0 is increased in relation to the pressure p(r 0 )=p 0 generated at the level of the radial seal distance r 0 . The resultant force F which acts on the end side of the piston 2 can be calculated by integration of the pressure p(r) across the region from the radial inside distance ri to the radial outside distance ra of the piston 2 .
[0026] It is therefore possible to utilize the fact that a centrifugal-force-dependent pressure component p centrifugal — oil in the outer section of the chamber 8 can be compensated by means of a corresponding vacuum in the inner section of the chamber 8 . The essence of the concept is therefore a suitable diameter selection which considerably reduces the overall centrifugal-force-dependent pressure, thereby permitting structural designs with reduced centrifugal force compensation or even no centrifugal force compensation. By means of suitable gradation of the diameters of the piston seals relative to the diameters of the rotary leadthrough seals, or of the radial inside distance and radial outside distance of the piston relative to the radius of the rotary leadthrough seals, the centrifugal oil pressure can be entirely or partially compensated even without using a counteracting compensation piston.
[0027] If a value of smaller than the radial seal distance r 0 , and therefore smaller than the radius of the rotary leadthrough seals, is selected for the radial inside distance of the piston, then during a rotation, a vacuum is generated in that region of the chamber 8 which is at a radial distance from the rotational axis of less than the seal distance r 0 . Furthermore, the radial outside distance ra of the piston is preferably selected such that, in the outer region of the chamber 8 , a centrifugal oil pressure is generated which, in interaction with the described vacuum, is suitable for forming overall pressure conditions within the chamber 8 which correspond to ambient pressure or the desired actuating pressure.
[0028] If a value of smaller than the radial seal distance r 0 , and therefore smaller than the radius of the rotary leadthrough seals, is selected for the radial inside distance of the piston, then during a rotation, a vacuum is generated in that region of the chamber 8 which is at a radial distance from the rotational axis of less than the seal distance r 0 . Furthermore, the radial outside distance ra of the piston is preferably selected such that, in the outer region of the chamber 8 , a centrifugal oil pressure is generated which, in interaction with the described vacuum, is suitable for forming overall pressure conditions within the chamber 8 which correspond to ambient pressure or the desired actuating pressure.
[0029] FIG. 2 shows a first exemplary embodiment on the basis of a dual clutch, illustrating the components and functional elements which have been described on the basis of FIG. 1 . Here, identical reference symbols denote the components described on the basis of FIG. 1 , such that only differences will be described. Further rotatable components 10 , 11 , in this case transmission input shafts of a dual-clutch transmission, are arranged within the rotatable component 1 which is designed as a piston seal. In addition to a chamber 8 for holding a first piston 2 , the rotatable component 1 has a second chamber 8 * for holding a second piston 2 *. Corresponding further components of a multiple clutch can be actuated in the usual way by means of the two pistons 2 , 2 *. The illustrated embodiment shows an arrangement in which a separate line of the line arrangement 4 leads to each of the chambers 8 , 8 *.
[0030] As in the embodiment depicted in FIG. 1 , it is also the case in the embodiment depicted in FIG. 2 that the dimensioning of the radial distances to the rotational axis ω is selected such that the radial inside distances ri, ri* of the two pistons 2 , 2 * are again smaller than the radial seal distance r 0 of the rotary leadthrough seal 3 . In the case of different radial inside distances ri, ri* of the two pistons 2 , 2 *, a separate line arrangement 4 is preferably provided, for setting the resultant forces in the chambers 8 , 8 *, for each of the chambers 8 , 8 * in order to be able to predetermine the pressure conditions individually. In this exemplary embodiment, the radial outside distances ra, ra* of the two pistons 2 , 2 * are each selected to be greater than the radial seal distance r 0 .
[0031] FIG. 3 shows a further exemplary embodiment of a dual-clutch device, in contrast to the embodiment in FIG. 2 , having an integrated torsional vibration damper 12 . As in FIG. 2 , additional pistons seals 13 are illustrated. The two pistons 2 , 2 * actuate in each case one associated clutch 14 , 14 *.
[0032] It has been found that a clutch arrangement according to the invention can be activated more effectively and more precisely on account of the elimination, or at least reduction, of centrifugal-force-dependent pressure components.
[0033] The present invention has been described in an illustrative manner. It is to be understood that the terminology that has been used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the present invention may be practiced other than as specifically described. | The invention relates to a coupling arrangement comprising a component ( 6 ) fixed to a housing, a piston ( 2 ) that is located rotatably about an axis of rotation (ω) relative to the component ( 6 ) fixed to a housing, a rotatable component ( 1 ) designed as a component mounted rotatably about the axis of rotation (ω) relative to the component fixed to a housing and having a chamber ( 8 ) in the front region of the piston ( 2 ), a line arrangement ( 4 ) forming a communication line through the component ( 6 ) fixed to a housing and the rotatable component ( 1 ) to the chamber ( 8 ) for a pressure medium, and a rotary feedthrough seal ( 3 ) sealing the line arrangement ( 4 ) between the component ( 6 ) fixed to a housing and the rotatable component ( 1 ), wherein a radial inner distance (ri) and/or a radial outer distance (ra) of the piston ( 2 ) from the axis of rotation (ω) is less than a radial seal distance (r 0 ) of the rotary feedthrough seal ( 3 ). | 5 |
CROSS REFERENCE TO RELATED DOCUMENTS
[0001] The present invention claims benefit of priority to U.S. Provisional Patent Application Ser. No. 61/244,038 of DOYLE et al., entitled “PNEUMATIC INFLATING DEVICE CONTAINED ENTIRELY WITHIN SHOE SOLE,” filed on Sep. 19, 2009, and is related to commonly-assigned U.S. Pat. Nos. 5,222,312; 6,305,102; and 6,725,573 of Harold S. DOYLE, the entire disclosures of which are hereby incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates to shoes, and, more particularly, to pneumatic cushioning therein.
[0004] 2. Discussion of the Background
[0005] Prior art shoes have involved a variety of inflation devices disposed at different locations. For instance, previous shoe arrangements have included soles that can be inflated at the arch to provide support. Other shoes contain soles which have sealed inflated chambers disposed within the soles in order to increase vertical bounce. These previous chambers are soft-sided bladders which distort into a more convex or spherical shape upon inflation. If the walls of the bladder are not constrained, for instance, by the structure of the sole of the shoe, the distortion occurs in every direction.
[0006] Others have addressed this problem by placing a foam core inside the bladder and adhering the entire surface of the interior bladder walls to the entire exterior surface of the foam core as is taught in U.S. Pat. No. 5,235,715 to Donzis. This arrangement of adhering all of the surface of the foam core limits the shape of the bladder to the shape of the foam core and does not allow for differential distortions of the bladder as the bladder is inflated. Such prior art shoes also have not allowed for selective adjustment of the pressure in the bladder chambers and may result in uneven air distribution in the sole of the shoe.
[0007] Pumps in prior art shoes have typically been either externally connectable to the shoe's air chambers or positioned in low stress areas on the upper portion of the shoe such as in the tongue or on the back of the heel. Such prior art shoes encounter different problems in use. For externally connectable pumps, the pump must be retrieved whenever inflation is desired. Pumps positioned on the upper portion add bulk to the shoe and limit agility. Such pumps also inhibit aesthetic choices in shoe design. Aesthetics may be particularly vital for golf shoes or non-athletic shoes.
[0008] In addition, the typical prior art shoe arrangements have either utilized pump actuators which were nonintegral with the shoe and required connection before inflation and disconnection before normal shoe use, or pump actuators which were connected to the external surface of the shoe, such as on the heel as in U.S. Pat. No. 5,222,312 to Doyle. Nonintegral pump actuators require that the shoe wearer retrieve the actuator every time inflation is needed. External pump actuators impose aesthetic limitations on footwear and add bulk to the “footprint” of the footwear.
[0009] Prior art shoes which have incorporated adjustable pneumatic cushioning have typically provided several air chambers in different areas of the sole which are interconnected via tubing. Eliminating the use of several distinct chambers would further reduce the weight of the shoe and simplify shoe construction. In addition, a complementary configuration between the pump, pump actuator, air release valve, and the air chamber or bladder could significantly reduce the bulk of the shoe.
[0010] It is, therefore, desirable to provide for improved pneumatic cushioning in footwear while including all necessary components for such cushioning within shoe and minimizing shoe bulk and aesthetic limitations. A shoe sole which addresses the problems of known footwear would be an important advance in the art.
SUMMARY OF THE INVENTION
[0011] Accordingly, a need addressed by the invention includes providing an improved pneumatic cushioning system entirely within the confines of a shoe sole.
[0012] Another need addressed by the invention includes providing a pneumatic inflation device with air release valve which is fully recessed in a shoe sole.
[0013] Another need addressed by the invention includes providing a pneumatic inflation device with a locking mechanism to secure the pump actuator entirely within the sole and flush with the sole's outer wall when not in use.
[0014] Another need addressed by the invention includes providing a locking mechanism which is easily finger-operated to facilitate inflation by a shoe wearer.
[0015] Another need addressed by the invention includes providing a recess for storing the pump actuator and air release valve to prevent damage thereto.
[0016] Another need addressed by the invention includes providing a pneumatic inflation device in which the bladder and pump are complementary configured so as to minimize shoe bulk.
[0017] Still another need addressed by the invention includes providing a pneumatic inflation device entirely within a shoe sole, in which the pump is positioned to avoid excessive stress.
[0018] Still another need addressed by the invention includes providing a pneumatic inflation device entirely within a shoe sole, which includes a pressure-release valve to permit adjustment of bladder pressure.
[0019] This invention is an improved device for providing pneumatic cushioning within a shoe sole. The invention represents a significant advance over the state of the art by providing a shoe sole which encompasses every necessary component for adjustable pneumatic cushioning.
[0020] The device includes a pump and air release valve which is entirely within the sole, a pump actuator which is entirely within the sole when not in use, and an inflatable bladder which is entirely within the sole and is operatively connected to the pump.
[0021] The inventive device can further include a locking mechanism which secures the pump actuator within the sole. It is preferred that the pump actuator can be locked only when the pump-actuator cap is flush with the outer wall of the sole. Such an arrangement facilitates use of the locking mechanism by the shoe wearer. The locking mechanism is finger-operated to further facilitate use by the shoe wearer.
[0022] The pump actuator preferably includes a piston rod having a distal end which is attached to the pump-actuator cap. The cap is rotatably movable between locked and unlocked positions only when the cap is flush with the sole. The cap is movable in this position due to the structure of the piston rod. The piston rod includes at least one radially extending portion which also extends axially from the piston towards the cap. However, the radially extending portion does not reach the cap, rather, there exists a gap adjacent the cap.
[0023] The pump-cylinder top includes a slot which is sized to accept the piston rod and the radially extending portion. The piston rod can be moved in and out of the pump-cylinder freely. However, if the piston rod is inserted so that the radially extending portion moves completely past the pump-cylinder top, the rod can be rotated so that the radially extending portion is not positioned in-line with the slot. Thus, the pump actuator is locked in position within the pump cylinder.
[0024] The device is preferably positioned such that the pump is between the forefoot-pressure portion and the heel-pressure portion which strikes the ground first during walking or running by a typical shoe-wearer. This positioning prevents the pump from being damaged during the lifetime of the shoe.
[0025] The device is also preferably positioned such that the pump is oriented transverse to the longitudinal axis which passes from the heel to the toes. The device is more preferably oriented substantially perpendicular to that longitudinal axis.
[0026] The device is further preferably positioned in the midsole of the sole. The midsole being located between the outer sole which contacts external surfaces and the in sole which can typically be removed by the shoe-wearer.
[0027] The preferred bladder includes a bladder membrane which has an interior and exterior side, a foam core contained within the bladder and having a plurality of sides, and adhesive disposed on only one side of the foam core, and a portion of the interior side of the bladder membrane adhering to the adhesive.
[0028] The inflation device preferably further comprises an inlet conduit within the sole and connecting the pump to the bladder, a unidirectional flow valve between the inlet conduit and the bladder, a pressure-release valve within the sole and operatively connected to the bladder to permit the release of air from the bladder, and an exit conduit connecting the pressure-release valve to the bladder.
[0029] In order to minimize the bulk of the shoe, it is most preferred that the pump be positioned at least partially within the bladder. More preferably, the pump is positioned entirely within the bladder. In such a preferred embodiment, first and second inlet conduits have distal ends connected to the first and second bladders and proximal ends connected to a flow switching device, first and second unidirectional flow valves are disposed, respectively, within the first and second conduits and between the flow switching device and the first and second bladders, respectively, and first and second pressure release valves are operatively connected, respectively, to the first and second bladders.
[0030] The preferred device may also include a third bladder connected to the flow switching device by a third conduit; a third unidirectional flow valve between the flow switching device and the third bladder; and a third pressure release valve connected to the third bladder.
[0031] The invention also includes a pneumatically cushioned shoe having a sole and comprising a pump which is entirely within the sole, a pump actuator which is entirely within the sole when not in use, and an inflatable bladder which is entirely within the sole and is operatively connected to the pump. The pump actuator preferably includes a locking mechanism securing the pump actuator within the sole. The pump actuator more preferably includes a piston rod having a distal end with the locking mechanism including a finger-operated cap which is attached to the distal end. The cap is movable between locked and unlocked positions only when the cap is flush with the sole as discussed above.
[0032] Accordingly, in exemplary aspects of the present invention there is provided a pneumatically cushioned shoe having a sole including an integral outer wall for contact with external surfaces, the shoe including a pump with integral air release valve positioned within the sole; an inflatable bladder which is positioned within the sole and is operatively connected to the pump; and a pump actuator which is positioned within the sole when not in use, the pump actuator movable from a position beyond the outer wall of the sole to within the sole to pump fluid into the inflatable bladder.
[0033] In other exemplary aspects of the present invention there is provided an inflation device for a shoe, the inflation device including a sole, the sole defining an exterior surface and having an interior surrounded by the exterior surface, the interior including an inflatable bladder, the exterior surface including an exposed portion for contacting elements when being worn and a non-exposed portion covered by at least one other shoe component; and a pump with integral air release valve and having a pump actuator receivable within a pump cavity, the pump cavity positioned within the interior of the sole, the pump actuator movable from a position beyond the exposed portion of the sole to the interior of the sole to pump fluid into the inflatable bladder.
[0034] Still other aspects, features, and advantages of the present invention are readily apparent from the following detailed description, by illustrating a number of exemplary embodiments and implementations, including the best mode contemplated for carrying out the present invention. The present invention is also capable of other and different embodiments, and its several details can be modified in various respects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and descriptions are to be regarded as illustrative in nature, and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] The embodiments of the present invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:
[0036] FIG. 1 is a general schematic of the inflating arrangement utilized in the shoe;
[0037] FIG. 2 is a horizontal cross section of the shoe sole, revealing the inflation bladders and conduits;
[0038] FIG. 3 is a side view of the shoe showing transparent conduits and the flow switching device;
[0039] FIG. 4 shows a side bellows air pressurization unit coupled with an air release valve and a flow switching device;
[0040] FIG. 5 shows the air pressurization unit in the closed position;
[0041] FIG. 6 shows the air pressurization unit in the open position;
[0042] FIG. 7 is a sectional view of a switching input device;
[0043] FIG. 8 is a sectional view of the switching input device in a second position;
[0044] FIG. 9 is a sectional view of the switching device in a closed position;
[0045] FIG. 10 is a sectional view of a bladder with a foam core;
[0046] FIG. 11 is a horizontal cross section of the shoe sole, revealing the inflation bladder and conduits;
[0047] FIG. 12A is prospective view of a side of the inventive shoe;
[0048] FIG. 12B is a prospective view of the back of the inventive shoe;
[0049] FIG. 13A is a side view of the piston rod and cap disconnected;
[0050] FIG. 13B is a prospective view of the pump actuator and pump cylinder;
[0051] FIG. 13C is a side view of the pump cylinder and pump-cylinder top disconnected; and
[0052] FIGS. 14A-14D are side views of an integrated air pump and air release valve that can be used with the embodiments of FIGS. 1-13 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0053] Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, and more particularly to FIG. 1 thereof, there is illustrated
[0054] The present invention is directed to a shoe with a pneumatic inflating device disposed therein. The general schematic of the shoe inflating arrangement is shown in FIG. 1 and includes three bladder sets. However, it will be apparent that the arrangement is adaptable to any plurality of bladder sets. The arrangement includes a pump 12 with an inlet 14 and an outlet 16 . Outlet 16 is connected to a flow switching device 18 at a flow switching input 20 . Flow switching device 18 operates as a selective valve which allows air flow into at least two outlets, the preferred embodiment having a first outlet 22 , a second outlet 24 , and a third outlet 26 . Each outlet 22 , 24 , and 26 is connected to a corresponding conduit 28 , 30 , and 32 . Each conduit 28 , 30 , and 32 is associated with corresponding unidirectional flow valves 34 , 36 , and 38 . Each unidirectional flow valve 34 , 36 , and 38 is connected to corresponding conduit 40 , 42 , and 44 . Each conduit 40 , 42 , and 44 is further associated with corresponding pressure release valves 46 , 48 , and 50 . Conduits 52 , 54 , and 56 are connected to release valves 46 , 48 , and 50 and each conduit is connected to corresponding bladder sets 58 , 60 , and 62 .
[0055] FIG. 2 shows one arrangement of separate bladder sets 58 , 60 and 62 in the sole of shoe 100 in which forefoot bladder 62 is comprised of mid-forefoot bladder 64 and toe forefoot bladder 66 . Bladders 64 and 66 are interconnected by conduits 68 and 70 . This multiple bladder configuration may also be implemented on the other bladder sets.
[0056] To pressurize the pneumatic system, the wearer preferably engages outlet 16 of pump 12 with switching input 20 . Pump 12 is mounted on a base portion 74 in which inlet 14 comprises an orifice 76 having an unidirectional inlet valve 78 . As the bellows 82 is lifted, the change in volume of air chamber 80 causes a corresponding reduction in pressure, thus causing air to flow through orifice 76 and valve 78 into chamber 80 . Bellows 82 is operatively connected with cover 84 pivotally connected at hinge portion 86 . Cover 84 is latchable to lock 88 through means of flange 90 engaging lock 88 . Cover 84 is releasable through use of a semi-rigid material in its construction which will enable flexing and thereby cause disengagement of flange 90 from latch 88 . The wearer then compresses bellows 82 which allows air flow into switching input 20 . This in turn allows air to fill the selected bladder set via flow switching device 18 in which the wearer can selectively control the air input to bladder sets 58 , 60 , and 62 . The wearer may also adjust the pressure in each bladder set via the respective pressure release valve.
[0057] The invention can be adapted to utilize a number of different combinations of elements to effectuate the goals of the invention. Thus, in FIG. 3 , pump 12 could utilize an integral heel mounted plunger-type pump, as taught in U.S. Pat. No. 5,222,312, which is incorporated by reference herein. The plunger type pump could also be disposed in the sole of the shoe, or for that matter, located at any convenient place on the shoe. As an alternative to the plunger-type pump 12 , the bellows-type pump of FIGS. 4 , 5 , and 6 could also be used.
[0058] Another variation is in the use, in the alternative, of different arrangements for flow switching device 18 . A first embodiment could utilize a simple “lie” type flow switching device in which pressure at input 20 is applied equally at each of conduits 52 , 54 , and 56 applying equilibrium pressure at 20 using pump 12 and valves 34 , 36 , and 38 would result in equal pressurization of each bladder arrangement 58 , 60 , and 62 . Customization of pressures could be accomplished by the simple expedient of bleeding off high pressure to reduce pressure in one or more of the selected bladder arrangements 58 , 60 , and 62 . Well known valves of the Schrader type could be utilized with push button release or variations such as the Presta type which is effectively lockable for the tightening of a threaded collar on the valve needle.
[0059] A second alternative is to use a specially designed flow switching device having both flow directional control and valving control. Thus, switching device 118 in FIGS. 7 , 8 , and 9 uses rotor 122 contained within circumferential wall 124 of body 126 of device 118 . Body 126 also has a floor 128 and a top (not shown) to completely define an enclosed plenum 130 . Rotor 122 is sealed against wall 126 in such manner that rotor 122 may be turned in a plurality of positions. In FIG. 7 , inlet chamber 132 is aligned with inlet 20 and in communication with passageway 134 that, in FIG. 7 , further communicates to outlet 24 . By comparison, in FIG. 8 , rotor 122 has been turned so that conduit 134 is now in communication with outlet 22 while chamber 132 owing to its elongated configuration. In FIG. 9 , rotor 122 has been further turned so that both chamber 132 and conduit 134 abut wall 126 , thereby restricting passage of air between inlet 20 and any of outlets 22 , 24 , or 26 . In like manner, of course, the rotor could be aligned with outlet 26 and inlet 20 . It is also possible to adapt flow switching device 118 to a greater or lesser number of outlets, as desired. In the preferred embodiment, outlets 22 , 24 , and 26 would be associated with valves 34 , 36 , and 38 , respectively. As described above, these could be of the Schrader or other improved Schrader types. Use of this approach in addition to the positional adjustment of rotor 122 to the closed position as shown in FIG. 9 would minimize pressure loss from bladders 58 , 60 , and 62 .
[0060] Nevertheless, with the use of suitable sealing materials, and an integral pump, the user could dispense with all valves save the flow switching device 118 . Use of a resilient, air impervious rotor 122 could provide self-sealing while appropriate coatings or seals, in the nature of gaskets or O-rings, could also be utilized.
[0061] An additional variation would be to use a separable pump. This would save the user the bulk of having an attached pump, further enabling the use of a larger capacity pump obviating bulk or weight concerns and enabling the use of higher strength or more economical materials than would be desirable with an integral, attached pump. Use of a separable pump would be more likely to take advantage of the use of a valve 72 associated with inlet 20 , in the manner shown in FIG. 5 .
[0062] The bladders 58 , 60 , and 62 can be any plastic envelope. The bladder membranes forming the envelope are resistant to the passage of gas molecules but need not be totally impermeable. The gas within the bladder should not escape so rapidly that re-inflation of the bladder will be needed more often than every thirty minutes of use. The bladder may also contain a foam core 61 where the foam may be any foam such as ethyl vinyl acetate, polyurethane, a composite using these materials, or any other resilient sponge material known or that may become known in the footwear industry. One face of the foam core is secured to one interior wall or surface of the bladder. In the preferred embodiment shown in cross section in FIG. 10 , the top surface of the foam core 61 is secured by an adhesive 63 to the interior surface of the top membrane 55 of the inflatable bladder 57 . The adhesive 63 may be contact cement, heat activated cement, or solvent based cement. Alternatively, the bladder membrane may be attached to the foam core 61 by heat or radio welding.
[0063] Alternative embodiments are the attachment of the bladder membrane to the sides of the foam core or attachment of the lower membrane in the lower surface of the foam element.
[0064] FIGS. 11 , 12 A and 12 B, and 13 A, 13 B and 13 C depict the preferred inflation device disposed completely within the shoe sole.
[0065] FIG. 11 is a horizontal cross section of the shoe sole, revealing the inflation bladder and conduits. The embodiment shown includes only one inflatable bladder 58 .
[0066] Pump 12 is received within the recess occupied by bladder 58 so that the space necessary for pump 12 is minimized Pump 12 is positioned substantially perpendicular to the axis passing from the heel to the toes. Pump 12 is positioned between heel-pressure portion 250 and forefoot-pressure portion 260 so that pump 12 is not damaged through normal shoe use.
[0067] Pump actuator 210 is positioned within pump 12 (and is shown in phantom withdrawn from pump 12 ). Actuator 210 comprises a piston rod 230 with at least one radially extending side 234 . Radially extending side 234 fits within slot 280 on cylinder top 242 so that piston rod 230 may be moved in and out of pump cylinder 240 . Piston rod 230 includes gap 236 which is positioned between cap 200 and radially extending side 234 . When pump actuator 210 is inserted completely within the shoe sole, slot 260 and gap 236 are juxtaposed, thus allowing pump actuator 210 to be rotated. When radially extending side 234 is moved to a position not in-line with slot 236 , pump actuator 210 cannot be withdrawn from pump cylinder 240 and is locked in position. As shown in FIG. 12A , cap 200 can be moved in the direction of the arrows to either lock or unlock pump actuator 210 . Cap 200 is flush with the outer wall 220 of the sole when pump actuator 210 is locked in position.
[0068] As shown in FIG. 13C , cylinder top 242 is removable from pump cylinder 240 to allow for the insertion of pump actuator 210 therein. Cylinder 242 is thereafter sufficiently secured to cylinder 240 to prevent non-intentional removal thereof.
[0069] FIG. 13A depicts cap 200 disengaged from distal end 232 of piston rod 230 . In use cap 200 is sufficiently secured to rod 230 so that separation does not occur. Piston 238 is sized such that movement into cylinder 240 causes air to be force out of the pump chamber into the bladder.
[0070] Pump 12 is connected to bladder 58 via inlet conduit 28 and unidirectional valve 34 . Unidirectional valve 34 prevents air from escaping bladder 58 back into inlet conduit 28 . Bladder 58 is connected to pressure-release valve 46 via exit conduit 52 .
[0071] FIGS. 14A-14D are side views of an integrated air pump and air release valve that can be used with the embodiments of FIGS. 1-13 . In FIG. 14A , the integrated air pump and air release valve, include a piston heel 302 , stopper(s) 304 , a piston 306 , a holder 308 , a first spring 310 , a first rubber gasket 312 , a second spring 314 , a second rubber gasket 316 , an integrated check valve 318 , and a cylindrical housing 320 .
[0072] In FIG. 14A , the integrated air pump and air release valve is shown in the opened position, configured for starting the pumping of air into the system. In FIG. 14B , the integrated air pump and air release valve is shown in the pumping down stroke position, configured for pumping air into the system via the integrated check valve 318 , as shown by arrow 322 . In FIG. 14C , the integrated air pump and air release valve is shown in the locked position configured for maintaining air pumped into the system in the system via the integrated check valve 318 . In FIG. 14D , the integrated air pump and air release valve is shown in the air release position, configured for releasing air from the system via the integrated check valve 318 , as shown by arrow 324 . Advantageously, by integrating the air pump and the air release valve, as described with respect to FIGS. 14A-14D , the overall size of the system can be reduced.
[0073] Although the configuration depicting the inflating device being positioned entirely within the sole has only one set of bladder, inlet and exit conduit, and pressure-release valve, it is understood that such a inflating device could be used with each of the above-described configurations which utilize more than one such set.
[0074] Thus, it should be apparent that there has been provided, in accordance with the present invention, a shoe and inflation device for easily providing pneumatic cushioning in the shoe sole that fully satisfy the objectives and advantages set forth above.
[0075] While the present invention have been described in connection with a number of exemplary embodiments and implementations, the present invention is not so limited, but rather covers various modifications and equivalent arrangements, which fall within the purview of the appended claims. | A pneumatic inflation device disposed within the sole of a shoe and comprising a pump with integral air release valve and which is entirely within the sole, a pump actuator which is entirely within the sole when not in use, and an inflatable bladder which is entirely within the sole and is operatively connected to the pump. Such a device can include a mechanism to lock the pump actuator within the sole such that the mechanism's cap is flush with the outer wall of the sole and finger-operable to allow the shoe-wearer to easily operate the inflation device and release air therefrom. | 0 |
TECHNICAL FIELD
[0001] The present invention relates to a device for managing the operation of an artificial heart. More specifically, the device for managing the operation of an artificial heart according to the invention seeks to supervise and control the electrical power of an artificial heart. It also seeks to supervise the operation of the artificial heart so as to be able to affect the prosthesis or create a warning when it malfunctions.
STATE OF THE PRIOR ART
[0002] Habitually, when a person suffers from a substantial cardiac deficiency a heart transplant may be the only conceivable cure. In this case the deficient heart is replaced by a healthy heart taken from a donor. Bearing in mind the small number of donors, an implantable and independent artificial heart which attempts to reproduce faithfully the operation of the natural heart has been developed. The electrical energy required for the operation of the artificial heart can be provided in two different ways.
[0003] A first way consists in supplying the electrical energy required to operate the artificial heart by means of a portable battery which the patient can wear on them. The artificial heart is then connected to the portable battery by means of a wire passing through a cutaneous micro-perforation. By this means the external portable battery supplies the electrical power for the electronics of the artificial heart over this wire.
[0004] A second way consists in supplying the electrical energy required to operate the artificial heart by means of a hospital console. This type of power is generally used during the post-operative period.
[0005] Each power supply is controlled by a separate device operating independently. More specifically, the portable energy supply is controlled by a portable control device, while the power supplied by the hospital console is controlled by the hospital console. These two power management devices are obviously impractical and expensive.
DESCRIPTION OF THE INVENTION
[0006] One goal of the invention is therefore to remedy the disadvantages of the state of the art. Against this background, the purpose of the present invention is to provide a device for managing the operation of an artificial heart which is safe for the person fitted with such an artificial heart, and inexpensive.
[0007] To this end the invention relates to a device for managing the operation of an artificial heart, where the device for managing the operation of an artificial heart includes a management channel, and where the management channel includes:
management means manufactured and arranged to supervise and control the electrical power supply of an artificial heart, first insulation means manufactured and arranged to insulate the artificial heart electrically from the electrical power supply, and management means manufactured and arranged to supervise and control the electrical power supply.
[0010] By virtue of the invention a single device is able to supervise and control the electrical power supply of an artificial heart. The device according to the invention is also fitted with first means to insulate the artificial heart electrically from the electrical power supply, enabling safe operation of the artificial heart, and consequently the safety of the wearer of the artificial heart.
[0011] The device for managing the operation of an artificial heart according to the invention may also have one or more of the characteristics below, considered individually, or in all technically possible combinations:
[0012] In a non-restrictive implementation, the electrical power supply is provided by a portable electrical power supply and/or a fixed electrical power supply.
[0013] In a non-restrictive implementation, the first insulation means are manufactured and arranged to insulate the artificial heart electrically from the fixed electrical power supply.
In a non-restrictive implementation, the first insulation means are manufactured and arranged to insulate the artificial heart electrically from the portable electrical power supply.
[0015] In a non-restrictive implementation, the first insulation means are in compliance with standard NF-EN 60601-1.
[0016] In a non-restrictive implementation, the management channel also includes an interface for communicating with the artificial heart, where the communication interface is formed by an interface of the CAN or RS232 type.
[0017] In a non-restrictive implementation, the management channel also includes a communication isolator installed between the management means and the communication interface.
[0018] In a non-restrictive implementation, the management channel includes measuring means manufactured and arranged to measure the atmospheric pressure.
[0019] In a non-restrictive implementation, the management channel includes warning means manufactured and arranged to communicate with the management means so as to warn a user when an operational fault of the electrical power supply, of the management channel, of a second management channel and/or of the artificial heart is detected by the management means.
[0020] In a non-restrictive implementation, the management channel includes at least one external interface manufactured and arranged to allow communications between the management means and an external device.
[0021] In a non-restrictive implementation, the device for managing the operation of an artificial heart also includes a second management channel, where the second management channel is identical to the first management channel according to the invention.
[0022] In a non-restrictive implementation, the first management channel and the second management channel are installed in parallel, where the device for managing operation also includes second means for insulating the first management channel and the second management channel.
BRIEF DESCRIPTION OF THE FIGURES
[0023] Other characteristics and advantages of the invention will become clear from the description which is given of it below, by way of example and non-restrictively, with reference to the appended figures, in which:
[0024] FIG. 1 illustrates, diagrammatically, a first example implementation of a device for managing the operation of an artificial heart in accordance with the invention,
[0025] FIG. 2 illustrates, diagrammatically, a second example implementation of a device for managing the operation of an artificial heart in accordance with the invention,
[0026] FIG. 3 illustrates, diagrammatically, a third example implementation of a device for managing the operation of an artificial heart in accordance with the invention.
[0027] For reasons of clarity only elements of use in understanding the invention have been represented, not to scale, and schematically. In addition, similar elements in different figures have identical references.
DETAILED DESCRIPTION OF AT LEAST ONE IMPLEMENTATION OF THE INVENTION
[0028] FIG. 1 illustrates an example embodiment of a device 1 for managing the operation of an artificial heart 2 in accordance with the invention.
[0029] More specifically, an artificial heart 2 of this type has an unrepresented internal device. Such an internal device consists of sensors located on artificial heart 2 connected to a microprocessor located under the case of artificial heart 2 . To provide cardiac function regulation meeting the variable requirements of the person wearing this prosthesis the sensors record arterial pressure data and position data (rest periods and physical efforts). The microprocessor receives this data and continuously processes it. It is a genuine embedded computer, which ensures that the cardiac rhythm is suitable for the body's requirement, in particular by operating motorised pumps included in prosthesis 2 more or less rapidly.
[0030] Device 1 for managing operation of artificial heart 2 according to the invention is formed by a unit which may be fixed or worn on the patient. Management device 1 supplies information to the patient and relays remote diagnosis data to the hospital in order to monitor the wearer of artificial heart 2 remotely. This 24 h-a-day monitoring service allows the internal data relating to artificial heart 2 and the patient's physiological data to be monitored.
[0031] In general terms, to guarantee the patient's safety, management device 1 has two electrical power channels V 1 and V 2 which are fully independent from one another, in the event that one of them is defective.
[0032] When management device 1 is fixed (in other words connected to a hospital console) or portable and is operating in a manner called “independent operation”, two power supplies 5 can be used, namely a battery of hospital console 4 and a portable battery 3 . By this means the electrical energy required to operate artificial heart 2 is provided by a portable battery 3 and/or by a battery of hospital console 4 . Artificial heart 2 is connected to portable battery 3 , to hospital console 4 and to management device 1 via a connection interface 6 which is accessible through a cutaneous micro-perforation of the wearer of artificial heart 2 . This connection interface 6 consequently enables electrical power supply 5 to be connected, and also management device 1 , which conveys the data between the electronics embedded in artificial heart 2 and itself, in order to supervise and manage artificial heart 2 .
[0033] In a non-restrictive implementation illustrated in FIG. 2 , management device 1 can also be connected to mains power supply S; in this case the two batteries 3 and 4 are present, but the electrical energy is provided by a power supply supplied by mains power S. Batteries 3 and/or 4 are used only as back up when there is a power cut of mains power supply S. Mains power supply S can also enable the batteries to be recharged, and in particular portable battery 3 .
[0034] Management device 1 illustrated in FIG. 1 and in FIG. 2 includes a first management channel 10 and a second management channel 20 .
[0035] First management channel 10 includes management means 11 manufactured and arranged to supervise and control electrical power supply 5 of artificial heart 2 , where electrical power supply 5 is formed by a portable electrical power supply 3 and a fixed electrical power supply 4 of a hospital console.
[0036] First management channel 10 also includes first insulation means 12 , manufactured and arranged to insulate artificial heart 2 electrically from electrical power supply 5 . By this means, when artificial heart 2 is connected to an electrical power supply 5 , for example during the post-operative period, management device 1 then enables, for example, artificial heart 2 to be protected against an over-current. First insulation means 12 are also manufactured and arranged to insulate artificial heart 2 electrically from management means 11 . For example, first insulation means 12 are compliant with standard NF-EN 60601-1.
[0037] It should be noted that portable electrical power supply 3 can be of the lithium type or the hydrogen cell type.
[0038] First management channel 10 also includes an interface 13 for communicating with artificial heart 2 . This communication interface 13 can, for example, be of the CAN or RS232 type. In the case of a communication interface 13 of the RS232 type, first management channel 10 includes a communication insulator 14 installed between management means 11 and communication interface 13 of the RS232 type. In the case of a communication interface 13 of the CAN type, first management channel 10 includes a communication insulator 14 installed between management means 11 and communication interface 13 of the CAN type.
[0039] First management channel 10 also includes measuring means 15 manufactured and arranged to measure the atmospheric pressure. These measuring means 15 can be formed by a pressure sensor communicating with artificial heart 2 via communication interface 13 . These measuring means 15 are also manufactured and arranged to communicate with management means 11 .
[0040] First management channel 10 includes warning means 16 manufactured and arranged to communicate with management means 11 so as to create a warning. These warning means 16 can be formed by a warning light and/or by a buzzer.
[0041] Management means 11 are able, and manufactured, to detect a malfunction of electrical power supply 5 , a malfunction of the communication with artificial heart 13 , a malfunction of a second management channel 20 or, generally, a malfunction of artificial heart 2 . Thus, when a malfunction of electrical power supply 5 occurs and is detected by management means 11 management means 11 can then alter first insulation means 12 to protect artificial heart 2 . In addition, when a malfunction of artificial heart 2 is detected by management means 11 the latter can activate an alarm intended to inform a practitioner and/or the wearer of artificial heart 2 .
[0042] First management means 10 also include at least one interface 17 manufactured and arranged to allow communications between management means 11 and an external device. For example, this interface 17 may be of the Ethernet, USB or Wi-Fi type, or any other interface enabling management means 11 to be connected, by wired or wireless means, with an external device.
[0043] Management device 1 also includes a second management channel 20 ; second management channel 20 is Identical to first management channel 10 , except for interface 13 for communicating with artificial heart 2 , which may be different. Consequently, in the example illustrated in FIG. 1 , second management channel 20 includes:
management means 11 manufactured and arranged to supervise and control electrical power supply 5 of artificial heart 2 , first insulation means 12 manufactured and arranged to insulate artificial heart 2 electrically from electrical power supply 5 , and from management means 11 , an interface 13 for communicating with artificial heart 2 ; in the case of a communication interface 13 of the RS232 type 13 second communication channel 20 also includes a communication insulator 14 installed between management means 11 and communication interface 13 of the RS232 type; in the case of a communication interface 13 of the CAN type, second management channel 20 also includes a communication insulator 14 installed between management means 11 and communication interface 13 of the CAN type, measuring means 15 manufactured and arranged to measure the atmospheric pressure, warning means 16 manufactured and arranged to communicate with management means 11 so as to create a warning following a malfunction of electrical power supply 5 , a malfunction of the communication with artificial heart 13 , a malfunction of first management channel 10 and/or a malfunction of artificial heart 2 , at least one interface 17 manufactured and arranged to allow communications between management means 11 and an external device. It should be noted that first management channel 10 and second management channel 20 are installed in parallel. In order to protect first management channel 10 from second management channel 20 , and vice versa, management device 1 , which is in accordance with the invention, includes second means 18 for insulating first management channel 10 with second management channel 20 .
[0051] In other words, management device 1 is formed from two management channels 10 and 20 operating completely independently from one another. Each of the two channels can in particular manage:
the electrical energy sources, to ensure that the electrical energy is indeed supplied to artificial heart 2 , in a precise manner, a communication link with artificial heart 2 , for example a link of the CAN type to first channel 10 and a link of the RS232 type to second channel 20 , a warning in the event of a failure of electrical power supply 5 and/or of artificial heart 2 and/or of management channels 10 and 20 , by means of a sound and/or visual alarm, dialogue with the other management channel, so as to detect a malfunction of the other channel.
[0056] In addition, in the illustrated example, management means 11 are powered electrically via electrical power supply 5 .
[0057] FIG. 3 illustrates an example implementation of a management channel 10 of management device 1 which is in accordance with the invention. A single management channel is represented for the sake of clarity.
[0058] In this non-restrictive example, management channel 10 includes management means 11 manufactured and arranged to supervise and control electrical power supply 5 of artificial heart 2 . In this example, electrical power supply 5 is formed by a portable electrical power supply 3 and a fixed electrical power supply 4 . These two electrical power supplies are connected to a connection interface 6 connected to artificial heart 2 via a first electrical power supply channel V 1 . The layout of this electrical power supply channel V 1 is given here as an example, and may be different. In addition, the various functions of the various represented models of electrical power supply channel V 1 will be described below.
[0059] Electrical power supply 5 is also used to supply energy to power supply 30 supplying power to management means 11 . To accomplish this a converter 31 of the DC/DC type is installed between electrical power supply 5 and power supply 30 supplying power to management means 11 . The electrical power supplied to management means 11 may be of the order of 5 V. DC/DC type converter 31 may be compliant with standard NF-EN 60601-1.
[0060] As an illustration, management means 11 can be formed by:
a processor 32 , for example of the I.MX6 type, a dynamic memory 33 , where this dynamic memory can, for example, be formed by four units of the DDR3L type of 256 MB to 1 GB each, and a mass storage device 34 , for example of the eMMC type, of 8 GB to 64 GB.
[0064] This implementation means that a high degree of functionality can be accomplished with a minimum of components. Due to this feature, each of management means 11 consumes less than 5 W. As a consequence, most of electrical power supply 5 is supplied to artificial heart 2 .
[0065] Management channel 10 includes not only management means 11 manufactured and arranged to supervise and control electrical power supply 5 of artificial heart 2 , but also first insulation means 12 manufactured and arranged to insulate artificial heart 2 electrically from management means 11 , where these management means 11 can be connected to a fixed potential via one or more external connections. First insulation means 12 are also manufactured and arranged to insulate artificial heart 2 electrically from electrical power supply 5 .
[0066] In general terms, management means 11 and first insulation means 12 communicate in order to be able:
to halt to the operation of insulated DC/DC converter units 35 ; this function may be used for self-test requirements, or for safety problems (e.g.: when management means 11 detect that artificial heart 2 has been short-circuited for a determined period); these insulated DC/DC converter units 35 enable artificial heart 2 to be insulated electrically from electrical supply 5 , if necessary, to supervise the power voltages to detect faults of artificial heart 2 , to adjust the voltage, via isolated DC/DC converter units 35 controlled by controller 37 , powered by voltage regulator 36 , to allow a balancing of the current supplied by each electrical power supply channel, to measure the current, via controller 37 , supplied to artificial heart 2 (this information enables a confirmation to be obtained that the power is indeed being supplied to artificial heart 2 ), in order to detect, via controller 37 , over-currents in the current supplied to artificial heart 2 , or to run tests of protective units 38 against excess voltage or over-currents; these tests may consist, for example, in lowering the detection threshold in order to check that it is activated.
[0072] All communications between management means 11 and the functions powering artificial heart 2 are made through first insulation means 12 , and comply, for example, with standard NF-EN 60601-1, with leakage currents below category CF (leakage currents of 0.22 μA typically with 264 V 60 Hz per insulator).
[0073] These first insulation means 12 can include not only insulated DC/DC converter units 35 , but also a digital insulator 39 and an insulator of the I2C type 40 .
[0074] Insulated DC/DC converter units 35 in particular enable artificial heart 2 to be insulated electrically from electrical power supply 5 .
[0075] Digital insulator 39 and insulator of the I2C type 40 in particular enable artificial heart 2 to be insulated electrically from management means 11 .
[0076] In addition, management channel 10 includes an interface 13 for communicating with artificial heart 2 . This communication interface 13 can be of the CAN or RS232 type. In the case of a communication interface 13 of the RS232 type, a communication insulator 14 is installed between management means 11 and communication interface 13 of the RS232 type.
[0077] In general terms, communication between management means 11 and artificial heart 2 can be made:
over a management channel (for example, first management channel 10 ), via a communication interface of the RS232 type, after passing through a communication insulator 14 , and upgrading by an RS232 driver 13 , over the other management channel (second management channel 20 ), via a communication interface of the CAN type through a communication insulator, without requiring any CAN driver.
[0080] It will be understood that first management channel 10 may include a communication interface 13 of the CAN or RS232 type, and second management channel 20 may include a communication interface 13 of the CAN or RS232 type.
[0081] In addition, management channel 10 includes measuring means manufactured and arranged to measure atmospheric pressure 15 . These means for measuring atmospheric pressure 15 may be formed by a pressure sensor. The sensor may also be welded on to the electronic card of processor 32 included in management means 11 .
[0082] Management channel 10 also includes warning means 16 manufactured and arranged to communicate with management means 11 . These warning means 16 enable the wearer of artificial heart 2 and/or a hospital to be warned if an operating fault of electrical power supply 5 and/or of artificial heart 2 and/or of management channels 10 and 20 is detected by management means 11 . These warning means 16 can, for example, be formed by a buzzer communicating with management means 11 .
[0083] In addition, management channel 10 includes external interfaces manufactured and arranged to allow communications between management means 11 and internal and/or external devices.
[0084] In the illustrated example external interfaces 17 are formed by:
An interface of the RS232 type 17 a, for example allowing a pressure sensor to be connected, A video interface 17 b of the LVDS or RGB parallel type enabling a screen included in management means 11 to be connected, A first interface 17 c of the USB 2 or SPI type enabling a touchscreen included in management means 11 to be connected, A matrix keyboard interface 17 d enabling a keyboard included in management means 11 to be connected, An interface 17 e enabling warning lights which may be used to generate an alert to be connected; A video interface of the HDMI type 17 f enabling an external screen to be connected, A second interface 17 g of the USB 2 type enabling an external touchscreen to be connected, A third interface 17 h of the USB 2 type enabling an external connection to be connected, A Gigabit Ethernet interface 17 i enabling an external device to be connected, An interface 17 j enabling a disk of the SSD type to be connected, where this disk of the SSD type can be embedded by management means 11 , or be external to them, An interface 17 k enabling a modem of the Wi-Fi type to be connected, An interface 17 l enabling a modem of the Bluetooth type to be connected, An interface 17 m enabling a modem of the GSM type to be connected.
[0098] It should be noted that these interfaces 17 are listed as indications only. Those skilled in the art will be able to remove certain these or add others, without however going beyond the scope of the invention.
[0099] In addition, management device 1 for managing the operation of an artificial heart according to the invention includes a second management channel 20 . This second management channel 20 is identical to first management channel 10 . First management channel 10 and second management channel 20 are installed in parallel. These two management channels 10 and 20 are insulated from one another via second insulation means 18 . These second insulation means 18 can be formed by an isolator of a digital type. More specifically, second insulation means 18 can be formed by I2C isolators (SMBus compatible). These insulation means 18 enable a dialogue to be established with electrical power supply 5 in order to obtain, in particular:
The voltage, The transmitted current, The battery's remaining capacity, The battery's temperature, The battery's condition.
[0105] This information is essential for the patient's safety when management device 1 is in autonomous mode. In addition, these second insulation means 18 ensure complete independence of the two management channels even in the event of a fault in one of the two management channels. | A device for controlling the functioning of a cardiac prosthesis, the device for controlling includes a control path, the control path having a control system designed and arranged to monitor and regulate the electrical supply of a cardiac prosthesis; a first insulating system designed and arranged to electrically insulate the cardiac prosthesis from the electrical supply; and a controller designed and arranged to monitor and regulate the electrical supply. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation of PCT Application No. PCT/NZ2011/000080, with an international filing date of May 20, 2011, which claims priority to New Zealand Application No. NZ585505, filed May 20, 2010, New Zealand Application No. NZ585532, filed May 21, 2010, and New Zealand Application No. NZ585594, filed Jun. 8, 2010. PCT Application No. PCT/NZ2011/000080, filed May 20, 2011, is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates to a method and system for the computationally efficient evaluation of the correlation of sequences, particularly, although not exclusively, nucleotide or protein sequences.
BACKGROUND TO THE INVENTION
[0003] The analysis of nucleotides to determine correlation between a sample sequence and a reference sequence may be computationally demanding. Sequences consist of multiple elements where the order of the elements in the sequence is important. Each element consists of a value, and different elements may have the same or different values. For genetic sequences, such as DNA or RNA, each element of the segment may take on one of the following values: A, C, G, T, and U. The length of a segment may vary from relatively small (for example thousands) to large (for example billions).
[0004] In general, a first sample sequence (known as a “read”) is analysed with regard to a second reference sequence, typically a genome. Often the reference sequence is a longer sequence than the sample sequence, and it is desired to determine whether the reference contains a segment that is similar or the same as the sample sequence. Reads may be contiguous, as with sequencers produced by Illumina Inc. or be non-continuous or overlapping, as with sequencers produced by Complete Genomics Inc. and Pacific Biosciences Inc. It is desirable for evaluation algorithms to be able to process any type of read.
[0005] Algorithms, such as the Smith Waterman algorithm and its derivatives, have been developed to compare different genomic sequences. Where the goal of the algorithm is to position a smaller sequence within a larger sequence, this algorithm is known as a gapped alignment algorithm. In many cases, the larger sequence is much longer than the smaller sequence, and as a result it is possible that there is more than one location in the larger sequence that is similar to the smaller sequence. There are often small differences between the sample sequence and the corresponding segment of the reference sequence. These errors may be random or systematic of the source of the sample sequence. For example, in the case of DNA sequences, the DNA sequencer reads each nucleotide in the read, but may incorrectly call the correct type as another. Another source of error is that the DNA segments may naturally be different to the reference genome. Differences include SNP (single nucleotide differences), MNP (multiple), large movements in a region of DNA, multiple copies of a region of DNA. Errors and differences may be accounted for by using masking techniques as described in other systems, such as in the applicant's international patent application Patent Application No. PCT/NZ2009/000245. Thus it may take a significant amount of computing time to evaluate a sample sequence at each position of a reference sequence for all relevant permutations.
[0006] Therefore, the goal of an alignment algorithm is to attempt to position the sample sequence within the reference sequence with the best possible match within as short as possible a processing time. This may involve placing an entire read (e.g. as many of the nucleotides in the read as possible) starting at a specific location. Alternatively we may wish to determine if parts of the read (for example, chimeric reads) are from different locations in the reference.
[0007] It is an object of the present invention to provide a method and system for evaluating the correlation of sequences that is more computationally efficient than prior techniques or which at least provides the public with a useful choice.
SUMMARY OF THE INVENTION
[0008] According to a first aspect there is provided a computer implemented method of evaluating a sequence using a plurality of evaluation algorithms, comprising applying the evaluation algorithms in an order designed to minimise the processing time for carrying out the required evaluation.
[0009] According to a further aspect there is provided a computer implemented method of evaluating the correlation between a sample sequence and a reference sequence using a plurality of evaluation algorithms, comprising applying the evaluation algorithms in an order designed to minimise the processing time for carrying out the required evaluation.
[0010] There is also disclosed a sequencing system comprising:
a. a sequencer for obtaining sample sequences; and b. processing means for evaluating sample sequences from the sequencer with respect to one or more reference sequences using a plurality of evaluation algorithms which are applied in an order designed to minimise the processing time for carrying out the required evaluation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The accompanying drawings which are incorporated in and constitute part of the specification, illustrate embodiments of the invention and, together with the general description of the invention given above, and the detailed description of embodiments given below, serve to explain the principles of the invention.
[0014] FIG. 1 shows the sequence of application of evaluation algorithms according to one embodiment;
[0015] FIG. 2 shows the comparison of a reference sequence and a sample sequence in step 1 ;
[0016] FIG. 3 shows the comparison of a reference sequence and a sample sequence in step 2 ;
[0017] FIG. 4 shows the comparison of a reference sequence and a sample sequence in step 3 ;
[0018] FIG. 5 shows a distributed sequence analysis system; and
[0019] FIG. 6 shows a parallel processing system according to one embodiment.
DETAILED DESCRIPTION
[0020] The invention will now be described by way of example only, with reference to examples based on the analysis of nucleotide sequences in the form of genomic sequences of DNA or RNA.
[0021] It is usual for different evaluation algorithms to have different properties with regard to speed and the number and frequency of matches between a sample sequence and a reference sequence.
[0022] Here, speed refers to how quickly the evaluation algorithm is able to produce results, whereas the quality represents the strength of a match (i.e. an identical match is the most significant and less statistically relevant matches are less significant).
[0023] Some alignment algorithms may be fast and produce strong matches, such as a simple “equality sequence aligner algorithm” which simply determines whether there is an exact match.
[0024] A fast algorithm may produce many possible “fires” (matches according to specified match criteria) in a short time, whereas a slow algorithm may produce a few possible areas of alignment in a long time. Evaluation algorithms may be ordered based on their number of matches and frequency of matches.
[0025] Take for example:
Algorithm 1 “fires” on 20% of the data and runs at 2000 alignments/sec Algorithm 2 “fires” on 30% of the data and runs at 3000 alignments/sec Algorithm 3 “fires” on 10% of the data and runs at 100,000 alignments/sec
[0029] Algorithm 3 makes the least alignments but it is so fast that if run first it may reduce the remaining data down to 90% resulting in a massive time savings. The quality of the matches produced by different algorithms may also be taken into account in determining the order of application of algorithms.
[0030] Based on knowledge of the characteristics of evaluation algorithms (their speed, number of matches with respect to processing time and statistical quality of matches) their order of application may be prescribed so as to minimise typical processing time.
[0031] The present system uses a set of evaluation algorithms one after another to evaluate potential alignment positions with high efficiency. In a multi-processor system a number of evaluation algorithms may be run in parallel and allocated to processors based on their speed and performance characteristics of the processors. For example slower processors may be allocated algorithms with short processing times (such as identity/equality algorithms) so that the results of that algorithm are not unduly delayed.
[0032] In the general case, the system uses faster evaluation algorithms first to reduce the number of potential alignment positions before using slower evaluation algorithms that may produce more and/or better quality matches to further reduce the number of potential alignment positions. However, due to different properties of the data and equipment, different orders of evaluation algorithms may be appropriate and the system is designed to also account for these factors.
[0033] Referring to FIG. 1 one possible sequence of evaluation algorithms will be described. Initially, there are nominally as many alignment positions in the reference sequence as there are elements in the reference system. In this embodiment, an initial alignment is performed in step 1 in which the reference sequence 6 in FIG. 2 is searched for exact matches to the sample sequence 7 in FIG. 2 (“equality sequence alignment”).
[0034] If one or more exact matches are discovered, then the one or more alignment positions are recorded as alignment positions with perfect alignment. For long reads it is highly unlikely that a position within the genome exactly matches with the sample sequence randomly, and so there is a high probability that at most one exact match will be found and that this will be the correct alignment. The probability of correct alignment is higher for longer sample sequences (the present embodiment typically employs sample sequences of about 18 to 22 bases). In this embodiment, if one alignment position is found in this step, the system ceases searching and returns the location of alignment with the reference sequence as the alignment position.
[0035] If an exact match is not found, or it is desired to also find similar but not exact alignment positions, then further evaluation algorithms may be applied.
[0036] In this embodiment, the sample sequence and reference sequence are then run through a lower bound algorithm 2. The purpose of this algorithm is to perform a first sample on the sequences by performing a coarse search of the reference sequence to ensure that there is a reasonable chance of discovering alignment positions for the sample sequence in the reference sequence. In this search the unmodified sample sequence is compared to the reference sequence and alignments are scored based on the quality of the alignment—i.e. points are added according to the nature of the misalignments to form a cumulative score at each position (as shown in FIG. 3 the sequences differ at two positions and the score at this position will be the cumulative value ascribed to these misalignments—e.g. “0” for matches and “1” for a substitution). If the score is greater than a threshold the sample sequence is rejected and if not processing proceeds to evaluation algorithm 3. This test is useful if there is a reasonable chance that the sample sequence is not related to the reference sequence and therefore unlikely to match at any point.
[0037] In step 3 the sample sequence is modified at each potential alignment position with the reference sequence. FIG. 4 illustrates an insertion in sample sequence 11 to achieve an alignment with reference sequence 10 (which may attract a score of “2” for example). The modifications to the sample sequences may be produced as set out in the applicant's international patent application Patent Application No. PCT/NZ2009/000245. The values ascribed to each modification will depend upon the sequencing machine employed, the type of sequence, the chemistry, a characteristic of the sequence etc. Modifications may be limited to those having a cumulative score below the acceptance threshold for the algorithm. Characteristics of the sequences may be obtained by preliminary analysis of the sequences. Alternatively these may be entered by a user.
[0038] In step 4 a seeded aligner is employed in which portions of the sample sequence that match the reference sequence are positioned and detailed evaluation algorithms analyse the gaps between the seeds. If a match with a score below a threshold value is found then this alignment may be recorded and processing may terminate.
[0039] If no alignment has a score below the threshold then a final evaluation algorithm may be employed. This may be an algorithm that returns the best alignment.
[0040] The further evaluation algorithms may be an algorithm based on the Smith Waterman algorithm such as the Gotoh aligner or Edit Distance aligner.
[0041] In one embodiment, the series of alignment algorithms may be predetermined before the system is run, which may be set by the user. In another embodiment, the series is at least in part determined by one or more parameters of the job. For example, the length of the sample sequence, information on the source of the sample sequence (i.e. the equipment that the sample sequence is sourced from), the alignment score desired by the user, and the specific knowledge of the reference sequence properties. In one embodiment, the series may be altered between applications of evaluation algorithms due to the results of the evaluation algorithms.
[0042] The first evaluation algorithm applied in general is a fast searching algorithm. The purpose of it is to reduce the number of potential alignment positions from being every position in the reference sequence to a smaller set of positions. Then typically a second, high coverage, but slower, evaluation algorithm is used to further reduce the set of potential alignment positions. Further evaluation algorithms may be applied until the set of alignment positions only contains alignments with better scores than the minimum set by the user. In one embodiment, the user selects a maximum operating time and/or number of evaluation algorithms to use, and once either of these conditions is met the system finishes searching for alignment positions. One of the evaluation algorithms may be a weighted probability algorithm that outputs a weighted probability of each position in the read being a variety of states (ATCG,deleted, etc). The weighted probability is a function of all possible “paths” from the start of the read to the end of the read.
[0043] In one embodiment, coarser searching algorithms (simple positioning algorithms) are used to obtain a set of possible alignment positions, and the finer searching algorithms (local or global alignment algorithms) are used to reduce this set until a specified level or certainty is reached. However, it is understood that depending on a variety of factors, different orders of algorithms may be used and different types. The ordering may be based upon historical information as to the performance of evaluation algorithms, a characteristic of the sequences concerned, the sequencing equipment used to obtain reads etc. A characteristic of the sequence may be obtained by user input or by preliminary analysis of one or more sequence. The system may also dynamically select the order of evaluation algorithms based on the results of algorithms that have already run or the order may be set at the start of processing or preset for a specific analyser. An evaluation algorithm engine may determine the order of application of algorithms and may be a rule based engine or artificial intelligence engine employing a neural network or genetic algorithm to select algorithm ordering. The evaluation algorithm engine may also include a “Meta-aligner” which alters the relative positioning of sequences as well as selecting the algorithms to apply. Such a Meta-aligner may be applied as a final algorithm to run in loops to attempt to find an alignment above a required threshold.
[0044] In one embodiment, a user selects a minimum alignment score. The alignment score is a measure of how well a segment of the reference sequence matches to the sample sequence. Typically, a higher score is given to segments which align well with the sample sequence. In one case, the score is a relative value, for example 90%, and limits possible segments to those that match within 90% of the sample sequence. The threshold may be based on “local alignment” where the score is determined based on alignment of only a portion of the sequences.
[0045] Referring to FIG. 5 a distributed sequence analysis system is shown. Sample and reference sequences are supplied to primary processor 12 which assigns tasks to secondary processors 13 to 16 . In this embodiment processors 15 and 16 have greater capacity than processors 13 and 14 . Primary processor 12 thus assigns processors 13 and 14 to process more efficient algorithms and processors 15 and 16 are assigned the more computationally involved algorithms.
[0046] Referring to FIG. 6 a parallel processing system according to one embodiment is shown. A primary processor 17 controls M parallel processing units 18 , which may conveniently be graphics processing units. In this embodiment the complete index of reads may be divided between parallel processing units 18 and reference sequences 19 may be streamed therethrough. In one embodiment M copies of the reference sequence that is N long may be streamed through the parallel processors. The index values supplied to parallel processors 18 may include various modifications of the reads (i.e. indels and substitutions) and/or multiple sample sequences. The parallel processing unit of FIG. 6 may be one of the secondary processors shown in FIG. 5 .
[0047] By ordering evaluation algorithms based on their processing time and likelihood of producing a determinative outcome processing time can be dramatically reduce.
[0048] While the present invention has been illustrated by the description of the embodiments thereof, and while the embodiments have been described in detail, it is not the intention of the Applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departure from the spirit or scope of the Applicant's general inventive concept.
Exemplary Embodiments
[0000]
1. A computer implemented method of evaluating the correlation between a sample sequence and a reference sequence using a plurality of evaluation algorithms, comprising applying the evaluation algorithms in an order designed to minimise the processing time for carrying out the required evaluation.
2. A method as claimed in claim 1 wherein the algorithms are ordered according to the number and/or frequency of matches with respect to processing time.
3. A method as claimed in claim 1 wherein the algorithms are ordered according to the number and frequency of matches with respect to processing time.
4. A method as claimed in any one of the preceding claims wherein at least one of the evaluation algorithms includes a rejection outcome.
5. A method as claimed in claim 4 wherein the rejection outcome results in no further evaluation algorithms being applied.
6. A method as claimed in any one of the previous claims wherein at least one of the evaluation algorithms includes an acceptance outcome.
7. A method as claimed in claim 6 wherein the acceptance outcome results in no further evaluation algorithms being applied.
8. A method as claimed in claim 6 or claim 7 wherein the acceptance outcome includes an evaluation result.
9. A method as claimed in any one of the previous claims where at least one of the evaluation algorithms includes a rejection outcome.
10. A method as claimed in claim 9 wherein the rejection outcome results in the next evaluation algorithm being applied.
11. A method as claimed in any one of the preceding claims wherein the first evaluation algorithm applied is an identity algorithm.
12. A method as claimed in any one of the preceding claims wherein a lower bound algorithm is applied to evaluate whether a comparison of the unmodified sample sequence and reference sequence results in a score within an acceptance range.
13. A method as claimed in claim 12 wherein the sample sequence is rejected if the score is outside the acceptance range and no further algorithm is applied.
14. A method as claimed in any one of the preceding claims wherein an algorithm is applied to evaluate whether a comparison of a modified form of the sample sequence and the reference sequence results in a score within an acceptance range.
15. A method as claimed in claim 14 wherein the score is modified based on the extent of modification of the sample sequence.
16. A method as claimed in any one of the preceding claims wherein one or more seeded alignment algorithm is employed.
17. A method as claimed in claim 16 wherein the one or more seeded alignment algorithm is employed.
18. A method as claimed in claim 17 wherein the one or more seeded alignment algorithm is based on the Smith Waterman aligner.
19. A method as claimed in any one of the previous claims wherein the order of application of algorithms is based on user input.
20. A method as claimed in any one of the previous claims wherein the order of application of algorithms is set by an ordering algorithm.
21. A method as claimed in any one of the preceding claims wherein an artificial intelligence engine determines the order of application of the evaluation algorithms.
22. A method as claimed in claim 21 wherein the artificial intelligence engine employs a neural network.
23. A method as claimed in claim 21 wherein the artificial intelligence engine employs a genetic algorithm.
24. A method as claimed in claim 19 wherein the ordering algorithm uses historical sequencing information to determine the order.
25. A method as claimed in any one of claims 19 to 24 wherein the ordering algorithm uses known information on the efficiency of the evaluation algorithms to determine the order.
26. A method as claimed in any one of claims 19 to 25 wherein the ordering algorithm uses source information relating to a sequence to determine the order.
27. A method as claimed in claim 26 wherein the source information includes at least one of: the sequencing equipment used to obtain the sample sequence; the type of sequence; and a characteristic of a sequence.
28. A method as claimed in claim 27 wherein a characteristic of a sequence is obtained by preliminary analysis of the sequence.
29. A method as claimed in any one of the previous claims wherein the order of application of evaluation algorithms is set before the application of the evaluation algorithms.
30. A method as claimed in any one of claims 1 to 28 wherein the order of application of evaluation algorithms is modified during the evaluation.
31. A method as claimed in claim 30 wherein the order is modified based on analysis of the previous and/or current evaluation algorithm results and/or performance.
32. A method as claimed in any one of the previous claims including setting an acceptance threshold, wherein the sequence evaluation ceases once the acceptance threshold has been met.
33. A method as claimed in any one of the previous claims wherein the evaluation results in a further sequence being aligned to the sample sequence being evaluated.
34. A method as claimed in claim 33 wherein the further sequence and the associated alignment information is recorded.
35. A method as claimed in claim 34 wherein the record is readable by a computer.
36. A method as claimed in any one of the previous claims wherein the sample sequence is a nucleotide sequence.
37. A method as claimed in any one of claims 1 to 35 wherein the sample sequence is a genomic sequence.
38. A method as claimed in claim 37 wherein the sample sequence is a DNA sequence.
39. A method as claimed in claim 37 wherein the sample sequence is a RNA sequence.
40. A method as claimed in any one of the preceding claims wherein at least one evaluation algorithm includes a positioning algorithm with changes the relative positioning of sample and reference sequences and one or more evaluation algorithm which iteratively evaluates local or global alignment at the various relative positions of the sequences.
41. A method as claimed in any one of the preceding claims wherein one of the evaluation algorithms outputs a weighted probability.
42. A system for implementing the method of any one of the previous claims.
43. A system as claimed in claim 42 wherein the system employs parallel processing.
44. A sequencing system comprising:
a. a sequencer for obtaining sample sequences; and b. processing means for evaluating sample sequences from the sequencer with respect to one or more reference sequences using a plurality of evaluation algorithms which are applied in an order designed to minimise the processing time for carrying out the required evaluation.
45. A sequencing system as claimed in claim 44 employing the method of any one of claims 1 to 40 .
46. A sequence analysis system employing multiple processors running multiple evaluation algorithms wherein evaluation algorithms are allocated to processors based upon performance characteristics of the processors.
47. A sequence analysis system as claimed in claim 46 wherein some of the processors are processors arranged to perform parallel processing of an algorithm.
48. A sequence analysis system as claimed in claim 47 wherein the parallel processors are graphics processors. | A method of evaluating correlation between sequences by employing a hierarchy of evaluation algorithms. The evaluation algorithms may be arranged in order of computational efficiency as specified by a user or as determined by the system. The algorithms may range from a simple equality algorithm through to seeded alignment algorithms etc.
Distributed and parallel processing systems may be employed in the method of the invention in graphical processing units may be employed.
The method may be employed with a wide range of sequencers including sequencers produced by Illumina Inc Complete Genomics Inc. and Pacific Biosciences Inc. | 6 |
CROSS-REFERENCES TO RELATED APPLICATIONS
The present application claims the benefit of U.S. Provisional Application No. 62/151,257, filed Apr. 22, 2015, which is hereby incorporated by reference for all purposes.
BACKGROUND OF THE INVENTION
Due to decreasing costs, state and federal tax incentives, and increased evidence and awareness of the correlation between CO 2 emissions and climate change, photovoltaic or “solar” power systems are becoming increasingly popular with consumers, businesses and utility companies. A basic solar power system consists of an array of solar panels connected together on one or more strings, a combiner for combining the outputs of the one or more strings, one or more string inverters for converting the combined direct current (DC) output from the strings to alternating current (AC), and a physical interface to AC grid power—typically on the load side of the utility meter, between the meter and the customer's main electrical panel.
The next step in the evolution of solar power system is on-site energy storage. Energy storage is important for a number of reasons. First, it provides a potential source of power when the grid is unavailable (outage). Second, in states and/or countries where the customer is unable to be compensated for sending power back to the grid or is compensated below the retail rate, it allows the customer to store the energy generated during the day—specifically when the solar array is generating the most power—and then consume that power after the sun has set reducing the customer's peak demand. Third, it allows the customer to supply power back to the grid at a time when the grid needs power the most. Localized energy storage can help utilities stabilize the grid by supplying power to enhance demand response, shave demand peaks, and shift loads to times of lower demand. Fourth, it provides a mechanism for storing grid power when demand is lower (i.e., when there is a surplus of power), smoothing utility companies' power demand curve from the bottom up. Fifth, by enabling customers to store energy onsite, it may be possible to bill customers for energy supplied to back-up loads when the grid is unavailable (e.g., during an outage).
BRIEF SUMMARY OF THE INVENTION
In accordance with one embodiment, a string inverter for use with a photovoltaic array includes a string-level DC input channel for receiving DC power from a photovoltaic array. The input channel performs channel-level maximum power point tracking. An input-output channel connects the string inverter to a battery pack. A DC to DC buck-boost circuit between the at least one DC input channel and the at least one input-output channel limits the amount of DC voltage from reaching the battery pack so that it does not exceed a predetermined threshold. A DC to AC inverter circuit having an AC output serving as an output of the string inverter. A revenue grade power meter is configured to measure the AC output of the string inverter.
In one embodiment, the string inverter includes a three position switch, wherein in a first position, AC power is permitted to flow from the string inverter to a load side of a customer utility meter and one or more back-up loads, in a second position, power is permitted to flow from the load side of a customer utility meter to the one or more back-up loads bypassing the string inverter, and in a third position, all circuits tied to the string inverter's output are electrically disconnected from each other.
In another embodiment, the string inverter further includes a first circuit for metering the total DC power received at the at least one DC input channel from the photovoltaic array, a second circuit for metering a total DC power received at the at least one input-output channel from the battery pack, and a controller programmed to determine the portion of total AC output measured by the revenue grade power meter attributable to the at least one DC input channel and the at least one input-output channel.
In another embodiment, the string inverter is operable to receive AC power, to rectify the AC power to DC power, and to deliver the rectified DC power to the battery pack.
In accordance with another embodiment, a string inverter for use with a photovoltaic array includes at least one string-level DC input channel for receiving DC power from a photovoltaic array, at least one input-output channel for connecting the string inverter to a battery pack, a DC to AC inverter circuit having an AC output serving as an output of the string inverter, and a switch controlling a flow of power through the string inverter. In one variation, the switch is configured so that in a first state, AC power is permitted to flow from the string inverter to a load side of a customer utility meter and one or more back-up loads, in a second state, power is permitted to flow from the load side of a customer utility meter to the one or more back-up loads bypassing the string inverter, and in a third state, all circuits tied to the string inverter's output are electrically disconnected from the inverter.
In accordance with another embodiment, a string inverter for use with a photovoltaic array includes at least one string-level DC input channel for receiving DC power from a photovoltaic array, at least one input-output channel for connecting the string inverter to a battery pack, a DC to AC inverter circuit having an AC output serving as an output of the string inverter, and a revenue grade power meter configured to measure the AC output of the string inverter. In one variation, the revenue grade power meter includes a first circuit for metering a total DC power received at the at least one DC input channel from the photovoltaic array, a second circuit for metering a total DC power received at the at least one input-output channel from the battery pack, and a controller programmed to determine the portion of total AC output measured by the revenue grade power meter attributable to the at least one DC input channel and the at least one input-output channel.
In accordance with still another embodiment, a string inverter for use with a photovoltaic array includes at least one string-level DC input channel for receiving DC power from a photovoltaic array, at least one input-output channel for connecting the string inverter to a battery pack, a DC to DC buck-boost circuit coupled to the at least one DC input channel, the DC to DC buck-boost being configured to prevent more than a predetermined amount of voltage from reaching the battery pack, and a DC to AC inverter circuit having an AC output serving as an output of the string inverter.
In accordance with yet another embodiment, a string inverter for use with a photovoltaic array includes at least one string-level DC input channel for receiving DC power from a photovoltaic array, at least one input-output channel for connecting the string inverter to a battery pack, a DC to DC buck-boost circuit coupled to the at least one input-output channel, the DC to DC buck-boost being configured to prevent more than a predetermined amount of voltage from reaching the battery pack, and a DC to AC inverter circuit having an AC output serving as an output of the string inverter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a block diagram of an exemplary solar energy generation system according to one embodiment;
FIG. 2 illustrates a more detailed block diagram of the system shown in FIG. 1 ;
FIG. 3 illustrates two sides of an inverter box according to one embodiment;
FIG. 4 illustrates a technique for metering the amount of power generated by the system; and
FIGS. 5-9 illustrate various possible power flow states of the inverter system according to various embodiments.
DETAILED DESCRIPTION OF THE INVENTION
In order to unlock the full potential of energy storage devices in solar energy generation systems and to ensure safe and efficient operation, there is a need for more sophisticated control systems and related circuitry that are capable of interfacing with high voltage, on-site energy storage systems. To that end, this disclosure teaches systems, methods, devices and related circuits that improve the operation of solar energy generation systems that incorporate localized energy storage.
FIG. 1 illustrates a block diagram of an exemplary solar energy generation system according to various embodiments disclosed herein, and FIG. 2 illustrates a more detailed block diagram of the same system showing additional internal components, overall system wiring and inverter wiring compartment interconnections.
In the system of FIGS. 1 and 2 , a pair of photovoltaic (PV) strings 102 are input to Inverter PCS (power control system) 104 . Each string may comprise a plurality of PV panels (not shown) connected serially with an additive direct current (DC) voltage somewhere between 100 and 1000 volts, depending on such factors as the number of panels, their efficiency, their output rating, ambient temperature and irradiation on each panel. Also, each MPPT (maximum power-point tracking) channel input may receive the output of two or more separate strings connected in parallel (i.e., a two (or more)-to-one combiner at each MPPT channel input).
In some embodiments, when the high voltage DC line from each string is input to the inverter, it is subject to maximum power-point tracking (MPPT) at the string level (e.g., dual MPPT in the exemplary system of FIGS. 1 & 2 ). Alternatively, each module, or a number of individual modules in the respective strings, may include a DC optimizer that performs MPPT at the module level or N-module level output, rather than at the string level. The various embodiments are compatible with either centralized or distributed MPPT.
In some embodiments, the inverter may include a DC/DC conversion stage 106 at the PV input side. DC/DC stages are commonly employed to insure that the voltage supplied to the DC/AC stage 108 is sufficiently high for inversion. However, unlike conventional inverters, the inverter of FIGS. 1 and 2 also includes a DC link bus attached to a battery pack 110 so that the DC power coming from the strings can be used to deliver DC power to battery pack 110 to “charge the battery.” The DC link bus is represented by the capacitor bank shown between the two DC-DC converters and the DC-AC section in FIG. 1 . Battery pack 110 has a minimum and maximum associated operating voltage window. Because battery pack 110 has a maximum exposed input voltage limit that, in many cases, is lower than the theoretical maximum DC voltage coming off of the strings (open circuit voltage, V OC ), various embodiments of the invention include a buck-boost circuit 112 between the string-level PV input of inverter 104 and the DC-link connection to the battery pack. The inclusion of buck-boost circuit 112 will prevent voltages above a safe threshold from being exposed to battery pack 110 thereby eliminating the possibility of damage to battery pack 110 from overvoltage stress.
It should be appreciated that inverter 104 may have more than one mode of operation. In some modes, no power may be flowing from PV strings 102 to battery pack 110 , while in other modes power may be flowing exclusively to the battery pack, while in still further modes power may be flowing to a combination of the battery pack and the AC grid. In a first mode, illustrated in FIG. 7 , all available PV power may go to battery pack 110 as priority, with any surplus power being supplied to DC/AC stage 108 ( FIG. 1 ) of inverter 104 to be supplied to the grid 114 or delivered to back-up loads 116 . In a second mode, illustrated in FIG. 5 , all generated power may be supplied to DC/AC stage 108 of inverter 104 and either used to power back-up loads 116 , or supplied to the grid 114 . In yet other modes, illustrated in FIGS. 6 and 8 , battery pack 110 may be discharged to DC/AC stage 108 of inverter 104 alone ( FIG. 8 ) and/or with PV power from the strings 102 ( FIG. 6 ) to supply power to the AC grid 114 and/or back-up loads 116 . In a further mode, illustrated in FIG. 9 , power may come from the grid 114 , through DC/AC inverter 108 ( FIG. 1 ) to charge battery pack 110 , for example, at a time when the PV array 102 is not generating power and demand for power is at its lowest point (e.g., after sunset). In various embodiments, the selection of mode may be controlled by logic in battery pack 110 , in inverter 104 , or in both, or selection could be based on signals from an external source. The various modes of operation are described in greater detail further below in the context of FIGS. 5-9 .
With continued reference to the exemplary solar energy generation system of FIG. 1 , in this figure, there are two blocks 106 / 112 labeled “DC/DC (Buck-Boost)”. These blocks 106 / 112 represent alternative embodiments. In the first embodiment, the buck-boost circuit is located in the DC-link at the front end of inverter 104 (as depicted by block 106 ) so that the DC input(s) coming from PV strings 102 are always subject to buck or boost, keeping the voltage at DC link bus sufficiently high level for inversion while also preventing too high of a voltage from being presented to battery pack 110 . In this embodiment, there is no need for a second buck-boost circuit anywhere else. In the second embodiment, the buck-boost circuit is located between the DC link bus of Inverter 104 and battery pack 110 (as depicted by block 112 ) such that the high voltage DC inputs from strings 102 only go through the buck-boost whenever voltage is exposed to battery pack 110 . In this alternative embodiment, there may be an additional DC-DC boost stage at the input to the inverter but no need for a second buck circuit anywhere else. Either embodiment will prevent battery pack 110 from being exposed to excessively high voltages generated by the PV array. The voltage from the array could be as high as 500 Volts, or even 750 Volts in the case of a 1 kV PV system.
It should be appreciated that battery pack 110 in FIGS. 1 and 2 may be an exemplary commercially available residential li-ion battery pack with its own battery 120 only or battery 120 with DC/DC boost converter 118 or other topologies. Alternatively, battery 120 may be a lead acid battery, advanced lead acid battery, flow battery, organic battery, or other battery type. The various embodiments disclosed herein are compatible with numerous different battery chemistries. Various disclosed embodiments will work with other commercially available battery packs as well, however, the embodiments may have particular utility for systems that use high voltage battery packs (e.g., >48 volts) such as 200V-750V battery packs. As depicted by the dashed line boxing inverter PCS 104 and battery pack 110 in FIG. 2 , inverter PCS 104 and battery pack 110 may be housed in a wall-mounted housing located inside or outside of a residence or a commercial building. Alternatively, battery pack 110 and inverter PCS 104 may be located in separate housings.
Referring to FIG. 3 , this figure illustrates two sides of an inverter box according to various embodiments of the invention. The left side, labeled “inverter,” includes internal components that are generally in a fixed configuration and not intended to be modified by the installer or operator. The right hand side, labeled “wiring box,” includes wire interfaces to AC grid 114 as well as a connection to protected or back-up home loads 116 . For example, as shown in FIG. 2 , back-up loads 116 could include an AC compressor, fan, and/or clothes washer. A refrigerator/freezer combination could be another back-up load. These are just examples and are not intended to be limiting. The particular back-up load may be at the discretion of the installer or homeowner need by wiring the inverter's AC output directly to one or more breakers in the home owner's or business's main electric panel. Providing a separate connection via the inverter PCS wiring box for back-up loads may enable the battery pack to serve as back-up power for certain loads in cases where the grid power is lost. It is noted that the grid standard depicted in FIG. 2 (240V L-L/120V L-N) is merely exemplary. Other grid standards, such as 208 1-ph, 3-ph/ 277 1-ph/ 480 3-ph, may be integrated with the various techniques described herein.
In a typical solar power generation system, the inverter includes a high accuracy alternating current (AC) revenue grade meter (RGM) at the output so that the solar provider and/or customer can ascertain how much power the system is generating at any given moment and over time, and in some cases so that the customer can be billed or compensated with energy credit. Typically, this information is transmitted wirelessly from the inverter to a wireless router located in the home or business so that it can be viewed on a local or remote graphical user interface. However, with the addition of a battery, it may be desirable to have the ability to make a more granular measurement of not only the inverter's output to the AC grid or back-up loads, but also the respective outputs of the photovoltaic system and the battery (e.g., what percentage of the total AC power is attributed to each source). In certain cases, such as when there is an outage of grid, it may be desirable to bill a customer for the power supplied to their back-up loads via the battery pack or PV power, since ordinarily when the grid is down, a string inverter stops outputting power.
In order to accomplish this, as depicted in FIGS. 3 and 4 , revenue grade meter 312 , in certain embodiments of the invention, makes separate DC measurements of power coming into the inverter from the PV system and the battery. Measurement circuit 410 accurately meters a total DC power received from photovoltaic array 102 by measuring the current (I), voltage (V) and power (P) at the DC input channel. Measurement circuit 412 meters a total DC power received from battery pack 110 by measuring the current (I), voltage (V) and power (P) at the input-output channel. A controller 414 may be programmed to determine the portion of total AC output measured by the revenue grade power meter attributable to photovoltaic array 102 and battery pack 110 . By doing this, the combined AC output power measured by revenue grade meter 312 can be separately apportioned into power being generated by the PV system and the power being supplied by the battery pack. Also, as seen in FIGS. 2 and 3 , in various embodiments, the wiring box side of inverter PCS 104 may include a single DC disconnect that enables an operator to manually shut off all DC power from battery and PV system.
An additional feature of the embodiment illustrated in FIG. 3 is a bypass switch 318 built into or external to the inverter PCS wiring box. In some embodiments, the switch may be a three-position switch. In a first position, switch 318 may connect the inverter to grid 114 and also connect the inverter to back-up loads 116 using an internal relay, such as relay 316 depicted in FIG. 3 . In the second position, switch 318 may bypass back-up loads 116 directly to grid 114 . The third position of the switch may open all circuits so that everything is disconnected, meaning, AC grid 114 and back-up loads 116 are disconnected from the inverter. This may be useful, for example, if the inverter side of the inverter PCS fails and needs to be serviced or replaced. As depicted in FIG. 3 , the internal components of the inverter may include anti-islanding relay 314 and protected load relay 316 . Relays 314 and 316 together with bypass switch 318 route power between the inverter and grid 114 and back-up loads 116 based at least in part on the position of bypass switch 318 .
FIGS. 5-9 illustrate various possible power flow states of the inverter PCS system according to various embodiments. The various numerical values indicated in FIGS. 5-9 are exemplary and are provided solely for the purpose of more clearly conveying the various exemplary power flow states. In state 1, illustrated in FIG. 5 , inverter 104 will deliver a maximum power output equivalent to the maximum power rating of PV array 102 less any conversion losses attributable to inverter 104 . In this full PV inverter mode, battery pack 110 is on standby (not charging or discharging). In this state, the AC output power may, for example, be ˜6 kW to grid 114 or back-up loads 116 .
Referring to FIG. 6 , this figure illustrates state 2, a combined PV and battery inverter mode, where the combined output of PV array 102 and battery pack 110 is inverted and supplied to AC grid 114 or back-up loads 116 . In the example of FIG. 6 , inverter 104 delivers a maximum AC output of, for example, ˜6 kW, but only partial power (e.g., 4 kW) of it originates with solar power generation system 102 and the remaining power (e.g., 2 kW) is supplied by discharge capacity of battery pack 110 . The AC output power may be delivered to grid 114 or back-up loads 116 .
FIG. 7 illustrates state 3, another partial inverter mode, where PV array 102 is generating its theoretical maximum output (e.g., 6 kW+), which is supplied to inverter PCS 104 . Instead of inverting all of that power, primarily partial power (e.g., 2 kW) is utilized to charge battery 110 , with the remainder inverted and supplied to AC grid 114 or back-up loads 116 . In an alternate exemplary embodiment where PV array 102 generates 8 kW+, battery pack 110 can be charged with 2 kW with a full 6 kW being provided to the AC grid/Back-up loads.
FIG. 8 illustrates state 4, called full battery inverter mode. In this mode, all the power supplied by inverter PCS 104 to AC grid 114 or back-up loads 116 originates from discharging of battery 110 . This may occur, for example, at night or when PV system 102 is otherwise unable to generate power. In this example, the discharging battery 110 is, for example, only supplying ˜2 kW of AC power. Typically, the power capacity of battery 110 will be less than or equal to the maximum output of PV array 102 , though the disclosed embodiments are not intended to be limited as such. This mode may be useful to help level load sharing/moving situations and with peak shaving.
FIG. 9 illustrates a 5th state of power flow. In this state, like state 4, PV system 102 generates no power, however, grid 114 is supplying power back through the bi-directional inverter to charge battery 110 . This could be done, for example, at a time when grid power demand is relatively low and less expensive. Then, later in the day, when demand quickly rises, the system could shift to mode 4 or a variant of that, where battery 110 either supplies power to grid 114 or to back-up loads 116 .
The embodiments described herein are not to be limited in scope by the specific embodiments described above. Indeed, various modifications of the embodiments, in addition to those described herein, will be apparent to those of ordinary skill in the art from the foregoing description and accompanying drawings. Further, although some of the embodiments have been described herein in the context of a particular implementation in a particular environment for a particular purpose, those of ordinary skill in the art will recognize that their usefulness is not limited thereto and that they can be beneficially implemented in any number of environments for any number of purposes. Accordingly, the disclosure should be construed in view of the full breath and spirit of the embodiments as disclosed herein. | A string inverter for use with a photovoltaic array includes a string-level DC input channel for receiving DC power from a photovoltaic array. The input channel performs channel-level maximum power point tracking. An input-output channel connects the string inverter to a battery pack. A DC to DC buck-boost circuit between the at least one DC input channel and the at least one input-output channel prevents more than a predetermined amount of DC voltage from reaching the battery pack. A DC to AC inverter circuit having an AC output serving as an output of the string inverter. A revenue grade power meter is configured to measure the AC output of the string inverter. | 8 |
RELATED APPLICATIONS
[0001] Co-pending, commonly assigned U.S. patent application entitled “ALL TERRAIN VEHICLE POWERED MOBILE DRILL,” filed on the same day as this application, attorney docket number 111803.P002.
FIELD OF INVENTION
[0002] The invention relates generally to all terrain vehicles (ATV), and more specifically to a power takeoff adapted to an ATV and mechanical accessories that can be powered by the power takeoff such as a mobile drill.
ART BACKGROUND
[0003] An all terrain vehicle (ATV) contains a motor, a frame, and wheels which combine to provide a vehicle that is capable of conveying an operator over varied and difficult terrain. Such a vehicle has been employed for various uses; some uses are but are not limited to, delivering hunters into a hunting area, delivering ice fishermen onto a lake, etc. Additionally, the ATV has been used as a platform to mount devices thereon, wherein the device contains an auxiliary power source, such as a lawn mowing attachment powered by a motor separate from the motor of the ATV.
[0004] What is needed are methods and apparatuses for extracting power from the ATV engine without the need to include a separate power source for the attachment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The invention may best be understood by referring to the following description and accompanying drawings that are used to illustrate embodiments of the invention. The invention is illustrated by way of example in the embodiments and is not limited in the figures of the accompanying drawings, in which like references indicate similar elements.
[0006] FIG. 1 illustrates one embodiment of an all terrain vehicle adapted for use with a power takeoff.
[0007] FIG. 2 shows one embodiment of an all terrain vehicle transmission with a power takeoff.
[0008] FIG. 3 illustrates a sub-transmission shift assembly adapted to provide a neutral position according to one embodiment of the invention.
[0009] FIG. 4A depicts an all terrain vehicle transmission shaft extension according to one embodiment of the invention.
[0010] FIG. 4B shows a cross-sectional view of the all terrain vehicle transmission shaft extension illustrated in FIG. 4A .
[0011] FIG. 4C shows an end view of the all terrain vehicle transmission shaft extension illustrated in FIG. 4A .
[0012] FIG. 4D illustrates an exploded view of an all terrain vehicle transmission shaft extension and the transmission shaft according to one embodiment of the invention.
[0013] FIG. 5 illustrates an all terrain vehicle power takeoff according to one embodiment of the invention utilizing an all terrain vehicle transmission shaft extension.
[0014] FIG. 6 illustrates another embodiment of a power takeoff for an all terrain vehicle.
[0015] FIG. 7 shows a system to redirect a rotating shaft direction according to one embodiment of the invention.
[0016] FIG. 8 illustrates a power takeoff package according to one embodiment of the invention.
[0017] FIG. 9 illustrates a mobile drill according to one embodiment of the invention.
[0018] FIG. 10 shows a mobile drill powered by an all terrain vehicle power takeoff according to one embodiment of the invention.
[0019] FIG. 11A illustrates rotation of a drill mast about a Y axis according to one embodiment of the invention.
[0020] FIG. 11B illustrates rotation of a drill mast about an X axis according to one embodiment of the invention.
[0021] FIG. 12 shows a mast extension according to one embodiment of the invention.
[0022] FIG. 13 illustrates driving an impact hammer according to one embodiment of the invention.
DETAILED DESCRIPTION
[0023] In the following detailed description of embodiments of the invention, reference is made to the accompanying drawings in which like references indicate similar elements, and in which is shown by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those of ordinary skill in the art to practice the invention. In other instances, well-known circuits, structures, and techniques have not been shown in detail in order not to obscure the understanding of this description. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the invention is defined only by the appended claims.
[0024] Apparatuses and methods are described to provide a power takeoff for an all terrain vehicle (ATV) transmission. The power takeoff has general application to power various devices with power supplied from the ATV engine. A mobile drill is disclosed that derives power from an ATV power takeoff to power the drill and various accessories.
[0025] FIG. 1 illustrates one embodiment of an all terrain vehicle (ATV) adapted for use with a power takeoff. With reference to FIG. 1 , an ATV is shown generally at 100 . ATV 100 includes wheels 102 , 104 , 106 , and a fourth wheel (not shown). A cutaway view of the ATV body reveals the transmission 110 . Transmission 110 is generally composed of a main transmission and a sub-transmission. Power is extracted form the ATV engine by means of a power takeoff. A point from which to extract power is indicated by shaft 112 . Shaft 112 is capable of rotating and thereby supplying power to a mechanism coupled with shaft 112 .
[0026] When operating a device coupled with the shaft 112 , it can be advantageous, though not required, to place the transmission in a neutral position; thereby, eliminating the application of power to the wheels 102 , 104 , and 106 . In one embodiment, the transmission or sub-transmission of the all terrain vehicle can be shifted among a plurality of gears by the rotation of a rod (not shown) attached to a shift lever 114 , as viewed through a cutaway 124 . Shift lever 114 is connected by element 116 to a shift control lever 118 . Shift control lever 118 has a plurality of positions as shown within FIG. 1 . High gear is indicated by the “H” as shown at 120 , a neutral position is indicated by “N” at 122 , a low gear position is indicated by “L” at 126 , and a super low gear position is indicated by “SL” at 128 . An operator (not shown) can move the shift control lever 118 to the positions as desired according to the various modes in which the ATV can be used with the power takeoff.
[0027] FIG. 2 shows one embodiment of an all terrain vehicle transmission including a power takeoff. With reference to FIG. 2 , an ATV transmission is shown generally at 250 . Transmission 250 has an outer case 252 which can house, in one or more embodiments, a sub-transmission. Typically, an ATV has a main transmission which allows an operator to shift between a plurality of gears. The ATV can also have a sub-transmission, which allows further shifting between a second plurality of gears, wherein the second plurality of gears affords a lower range of gearing than does the plurality of gears in the main transmission. A transmission or sub-transmission shift lever is indicated at 266 . The shift lever 266 causes rotation of shaft 267 as indicated by arrow 268 . Movement of shift lever 266 places the ATV transmission or sub-transmission in one of a plurality of gears as described in conjunction with FIG. 1 above.
[0028] A transmission shaft 256 is configured with coupling means such as the spline shown in FIG. 2 . Other coupling means can be provided on the shaft 256 , such as but not limited to a slotted end, a square end, a keyed location, etc. Additionally, various mechanical devices can be coupled to the shaft 256 , such as a sheave, a sprocket, etc.; thereby, providing a means for moving the source of the power derived from the ATV engine (a further discussion of this topic is provided below in conjunction with FIG. 7 ). In one embodiment, the power takeoff point can include a flange 254 . Flange 254 can be configured with support 258 as may be required in certain applications. For example, if an existing transmission case is being retrofitted with a flange, a flange support 258 can be provided to keep the stresses applied to the transmission case 252 within allowable levels during operation of devices attached to the power takeoff.
[0029] In one embodiment, the flange 254 can receive a device 260 . Device 260 can be, in one embodiment, a hydraulic pump with intake and output ports 262 and 264 , into which, fluid is received and then output under pressure. In another embodiment, device 260 can be a generator or alternator; thereby, creating an electrical potential which can be used to power an electric motor or provide another function, such as, a power source for an arc welder.
[0030] FIG. 3 illustrates a sub-transmission shift assembly adapted to provide a neutral position according to one embodiment of the invention. With reference to FIG. 3 , a shift plate 302 is attached to a shift rod 304 . Shift rod 304 is supported by bearings (not shown); shift rod 304 is configured to rotate about an axis perpendicular to the plane of the figure as indicated by an arrow 306 . A shift lever 310 is fixedly attached to the shift plate 302 . A member 312 is rotateably attached to the shift lever 310 at connection 316 . Shift plate 302 is fixedly attached to shift rod 304 . Movement of the member 312 in the direction of arrow 314 results in rotation of the shift plate 302 (and the shift rod 304 ) about the longitudinal axis of the shift rod 304 . Various rotational positions of the shift plate correspond to placing the transmission in various gears. It will be recognized by those of ordinary skill in the art that member 312 can be replaced with other means for moving shift lever 310 , such as but not limited to a flexible cable, a chain and sprocket assembly, etc. The present invention is not limited by the way in which the shift rod is placed in a neutral position.
[0031] A detent mechanism keeps the shift rod 304 oriented at a fixed position. The detent mechanism includes an arm 320 configured to rotate about pivot point 322 . A force is generated by a pre-stressed member 350 . The pre-stressed member 350 can be a spring which applies a force to the arm 320 which induces rotation of the arm 320 in a counterclockwise direction. The arm 320 has a lobe 324 that engages with a notch in the shift plate 302 . In one embodiment, that can correspond to a sub-transmission used in an Artic Cat 250 or 300 ATV, Suzuki LT-F4WDX, LT-F4WD, models 250, 300, King Quad, etc. ATV as shown in FIG. 3 , the detent mechanism keeps the transmission in a “super low” position as indicated at 332 with annotation SL. Other notches corresponding to a gear position for “low” at 334 with annotation L and a gear position for “high” at 336 with annotation H are indicated on the shift plate 302 .
[0032] In one embodiment, the stock shift plate in the Artic Cat and Suzuki transmissions mentioned above can be adapted to include a notch 338 which places the sub-transmission in neutral. Placing the sub-transmission in neutral deprives power from the wheels of the ATV which may be useful in some applications of a power takeoff unit. The notch 338 is located midway between the notch for “high” at 336 and the notch for “low” indicated at 334 . Another position of the shift rod 304 that corresponds to neutral can be found by placing a notch at location 340 . Location 340 is between the notch for “low” 334 and the notch for “super low” 324 .
[0033] FIG. 4A depicts an all terrain vehicle (ATV) transmission shaft extension according to one embodiment of the invention. An isometric view of the transmission shaft extension is shown generally at 400 . Some transmissions require the transmission shaft to be modified to provide a means for coupling to the transmission shaft in order to extract power from the engine via the transmission shaft. According to one embodiment, a transmission shaft is modified to accept a transmission shaft extension, such as the transmission shaft extension 400 . Transmission shaft extension 400 has a cylindrical first part 403 having an outer surface 406 and an inner surface 408 . Both the outer surface 406 and the inner surface 408 are characterized by respective diameters. Transmission shaft extension 400 has a second part 405 having an outer surface 402 . Outer surface 402 has an outer diameter and a splined inner surface indicated by 404 . A cylinder 410 is located as shown within the first portion. The cylinder 410 is one embodiment of a coupling structure that permits joining two shafts together. Other coupling structures can be used; examples include, but are not limited to, a threaded region of either the inner or outer surface, locking rings, an axial interlock mechanism, etc.
[0034] FIG. 4B shows a cross-sectional view at 430 of the all terrain vehicle transmission shaft extension illustrated in FIG. 4A . In one embodiment, the first part 403 can be formed from a composite of two concentric cylindrical parts such as 436 and 434 . In one embodiment, inner cylindrical part 434 extends along the entire length of the first part and the second part. The inner part can be drilled to receive the rod 410 . Rod 410 can be press fit into the inner cylindrical part 434 . In one embodiment the outer diameter of rod 410 is 0.375 inches.
[0035] In one embodiment, selected for use with an Artic Cat 250 or 300 ATV sub-transmission or a sub-transmission used in a Suzuki LT-F4WDX, LT-F4WD (e.g., 250, 300 & King Quad), the inner cylindrical part 434 can be machined from a spline made by Spencer, Inc. model number “SP 738-20-11 S-32.” The outer diameter of the second part 402 is 0.785 inch. In one embodiment, the outer cylindrical part 436 is made from the inner race of a bearing made by Torrington, Inc., part number “IR-182216 MS-51962-12.” The outer diameter of the outer cylindrical part 406 measures 1.374 inch. The longitudinal extent of the second part, as indicated by 405 a , is 0.659 inch and the longitudinal extent of the first part, as indicated by 403 a , is 1.008 inch. In one embodiment, rod 410 is set back 0.246 inch from the edge of the outer cylindrical part as indicated at 407 .
[0036] FIG. 4C shows an end view, generally at 460 , of the all terrain vehicle (ATV) transmission shaft extension illustrated in FIG. 4A . With reference to FIG. 4C , the rod 410 is visible along with the inner surface 408 and outer surface 406 of the first cylindrical part, and the spline surface 404 .
[0037] FIG. 4D illustrates an exploded view of an all terrain vehicle (ATV) transmission shaft extension and the transmission shaft according to one embodiment of the invention. With reference to FIG. 4D , in one embodiment, transmission shaft 480 can be an Artic Cat 250 or 300 ATV transmission shaft or a Suzuki LT-F4WDX, LT-F4WD (e.g., 250, 300 & King Quad) ATV transmission shaft. Transmission shaft 480 has an end portion 476 and a shoulder 474 . In one embodiment, a slot 478 can be ground into the end portion 476 of transmission shaft 480 . After the slot 478 has been formed, the transmission shaft extension 400 can be mated with the transmission shaft 480 by moving the transmission shaft extension 400 in the direction indicated by arrows 472 .
[0038] With respect to the transmissions mentioned above, the slot 478 can be ground according to various methods. According to one method, the transmission shaft 480 can be ground while installed in the ATV transmission. A transmission case cover can be removed exposing the transmission shaft; thereby, allowing the end portion 476 to be ground with a slot. In another method, the transmission shaft 480 can be removed from the transmission; thereby, allowing the shaft to be inserted into a milling machine, for example, while the slot 478 is formed.
[0039] It will be recognized by those of ordinary skill in the art that other coupling techniques can be employed to create an extension for transmission shaft 480 within other embodiments of the invention. For example, shapes other than rods and slots such as 478 and 410 can be employed for coupling. The end portion 476 and the mating portion 408 can be configured with splines, threads, square cross-sections, etc., allowing the parts to mate; thereby, extending the effective length of the transmission shaft 480 .
[0040] FIG. 5 illustrates an all terrain vehicle (ATV) power takeoff according to one embodiment of the invention utilizing an all terrain vehicle transmission shaft extension. With reference to FIG. 5 , an ATV transmission is indicated generally at 500 . Typically, an ATV transmission is configured with a primary transmission and a sub-transmission, as described above. A transmission case, which may include the sub-transmission, has a left portion 502 and a right portion 504 . The transmission shaft 580 has a plurality of gears mounted thereon (not all are shown), such as a gear 520 . The gear 520 mates with a gear 522 as well as other gears (not shown) to provide the required transmission functionality. Only the pertinent portions of the transmission and/or sub-transmission are shown to preserve clarity during this description. In one embodiment, a transmission shaft extension 542 is configured with the transmission shaft 580 utilizing a slot 538 which mates with a rod 540 to provide an extension to the transmission shaft. The extension provides a means for coupling via the splines 544 to the transmission shaft extension. In one embodiment, the transmission shaft 580 and the transmission shaft extension can be prepared as described in conjunction with FIG. 4A , FIG. 4B , FIG. 4C , and FIG. 4D .
[0041] In one embodiment, directed to providing a power takeoff in an Artic Cat 250 or 300 ATV transmission or a Suzuki LT-F4WDX, LT-F4WD (e.g., 250, 300 & King Quad) transmission, bearing 506 is a bearing from Torrington, Inc. model number “HJ-223016 MS-51961-18.” The original stock bearing can be removed and replaced with the bearing mentioned above. It will be recognized by those of ordinary skill in the art that other configurations of transmission shaft extension 542 are possible utilizing other bearings and shaft geometry. The present invention is not limited to one bearing and shaft diameter. The transmission shaft 580 is supported in at least one other place by bearing 510 , shown in the opposite side of the transmission case.
[0042] In one or more embodiments, it may be necessary to provide a hole within the transmission case 502 to allow the transmission shaft extension 542 to pass through. It will be noted by those of ordinary skill in the art that a hole can be formed in the transmission case 502 by various means, such as, but not limited to, drilling, milling, grinding, etc.
[0043] FIG. 6 illustrates another embodiment of a power takeoff for an all terrain vehicle (ATV). With reference to FIG. 6 , an ATV transmission is shown generally at 600 . The transmission case has a left portion 602 and a right portion 604 . Similar to FIG. 5 , only the pertinent portion of the transmission and/or sub-transmission is shown in FIG. 6 to preserve clarity during the discussion. A transmission shaft 602 is adapted for coupling thereto as shown with splines 608 . The transmission shaft can extend outside of the transmission case 602 (as indicated by end 606 ) or the transmission shaft can reside within the confines of the transmission case. The coupling surface 608 will allow power to be diverted from the ATV engine by way of the transmission shaft 602 . The transmission shaft 602 is supported on the right side by a bearing 612 and the left side by a bearing 610 . The transmission shaft 602 has a plurality (all are not shown) of gears mounted thereon such as a gear 620 . The gear 620 meshes with a gear 622 to provide transmission functionality. Power is diverted to a power takeoff by coupling to the transmission shaft as previously described. The orientation of the rotating shaft can be redirected as needed for various devices that can be powered by the power takeoff.
[0044] FIG. 7 shows a system to redirect a rotating shaft direction according to one embodiment of the invention. With reference to FIG. 7 , an ATV transmission is shown generally at 700 . The transmission includes a case 702 , a transmission shaft 704 , with one or more gears indicated by 706 and 708 . The transmission shaft is supported by a bearing (not shown) to allow rotation about a longitudinal axis. In the embodiment shown in FIG. 7 , a portion of the transmission shaft 704 extends out of the transmission case 702 as indicated at 710 . In the embodiment shown in the figure, power is redirected by means of a sheave system and bevel gears. It will be noted by those of ordinary skill in the art that other systems can be employed to redirect power, such as a flexible shaft, etc. In the embodiment shown, a first circular member 712 is coupled with a second circular member 714 utilizing an appropriate flexible power transfer device 716 . In one embodiment, circular member 712 and 714 can be sheaves and 716 can be a belt. In another embodiment, 712 and 714 can be sprockets and 716 can be a chain. Secondary shaft 718 is supported by bearings (not shown), and is driven at one end by circular member 714 . In one embodiment, the secondary shaft 718 has a bevel gear attached as shown at 722 , bevel gear 722 meshes with bevel gear 724 to rotate shaft 726 as shown by arrow 728 . Bearings (not shown) support shaft 726 allowing the shaft to rotate about its axis. Housing 720 contains shaft 726 , gears 722 , 724 , and the associated bearings and other components needed to provide a remote location at which power can be extracted from the engine of the ATV. Such a remote location is another configuration for a power takeoff according to one or more embodiments of the invention. A complete power takeoff unit can be configured to house the necessary power takeoff components and associated auxiliary power systems according to several embodiment of the invention. Such auxiliary systems can facilitate operation, via a power takeoff, of a hydraulic motor, and an electric motor. A power takeoff can be configured to run attachments such as water pumps, grass cutters, winches, etc. The sheaves 712 and 714 can provide increased or decreased rotational speeds of the secondary shaft 718 relative to the transmission shaft 704 .
[0045] FIG. 8 illustrates a power takeoff package according to one embodiment of the invention. With reference to FIG. 8 , a power takeoff package is illustrated generally at 800 . In one embodiment, the power takeoff package includes a housing 802 . The housing 802 can be mounted in a convenient place on an ATV such as the back of ATV 100 ( FIG. 1 ). Power can be supplied to the power takeoff package 800 at 804 . Power supplied at 804 can be provided by means of a rotating shaft such as shaft 718 ( FIG. 7 ) or another suitable connection to an ATV transmission. Power supplied at 804 can be input to a hydraulic pump 806 wherein the pressure of fluid entering the pump at 810 is increased across the pump at 812 . High pressure hydraulic fluid is available at valve/control 816 . Valve/control 816 can be an integrated valve with a means for control or it can exist as a valve that is controlled by control 814 . A line 818 can serve as a high pressure output line and a line 820 can serve as a return line for the fluid. A load (not shown), such as a hydraulic motor, is connected to lines 818 and 820 . Fluid at low pressure returns via path 822 to a reservoir 808 . Reservoir 808 is connected via fluid path 810 to the hydraulic pump 806 thus completing the circuit of fluid flow.
[0046] Fluid can be cooled at 840 within the housing 802 or external to the housing at 842 . Device 840 can include a heat exchanger that dissipates heat as fluid flows therein. A fan can supply a flow of air across the heat exchanger to increase the rate of cooling applied to the hydraulic fluid. Alternatively or in conjunction with cooling device 840 a cooling device 842 can be configured on an ATV external to housing 802 to provide cooling for the hydraulic fluid. Such a device can include a heat exchanger with a shroud that is configured to direct air across the heat exchanger as the vehicle is moving. An alternative embodiment can include a fan that provides a flow of cooling air across a heat exchanger while the vehicle is stationary. The heat exchanger can be configured to provide cooling for engine oil as well as hydraulic fluid. Such an arrangement can be beneficial when the power takeoff is running an apparatus that requires the ATV to be stationary since ATV engines are often air cooled.
[0047] The control 814 is in communication with valves/control 816 as previously described. Control 814 can be a mechanically operated valve that stops the flow of hydraulic fluid and the control can switch the line that functions as the high pressure line with the return line; thereby, reversing the direction of the hydraulic motor (not shown) attached to lines 818 and 820 . Control 814 can be replaced or augmented by a wireless control 830 . Wireless control 830 can be configured with antenna 832 to communicate wirelessly with remote control 834 . Remote control 834 is equipped with antenna 836 and the pair is configured to provide wireless control of the hydraulic valves necessary to regulate the flow of hydraulic fluid to the hydraulic motor (not shown). Data from various sensors can be sent wirelessly to control 834 , such as hydraulic fluid pressure, etc. Control 814 or 834 can also be configured with a control to regulate the speed of an ATV engine that provides power 804 to the power takeoff unit 800 .
[0048] FIG. 9 illustrates a mobile drill according to one embodiment of the invention. With reference to FIG. 9 a mobile drill is shown generally at 900 configured on an all terrain vehicle (ATV). Mobile drill 900 includes an ATV having a transmission and/or sub-transmission configured with a power takeoff 902 . Power takeoff 902 is used to divert power to operate a drill head (not shown) via drill motor 908 . A drill mast 910 is movably coupled with the ATV at 912 ; the drill mast can rest in a cradle 914 during transit to the drill site. Movable couple 912 can provide rotation of the drill mast about two axes; thereby allowing the drill mast 910 to be plumbed without leveling the ATV as well as allowing the drill mast to be conveniently positioned for transit to the drill site. Rotation of the drill mast about one or more axes is referred to herein as a self-aligning mast. A self-aligning mast allows an operator to move the mobile drill to a drill site, align the mast vertically, and drill a hole in less time than it would take if the drill platform had to be leveled before drilling commenced. Additionally, increased drill platform stability is achieved by creating a self-aligning mast since mechanisms needed to level the drill platform are more problematic and prone to malfunction while drilling, especially on sloped ground. The self-aligning drill mast relies on the stability provided by the ATV in contact with the ground by means of the ATV tires and adjustable leg at the bottom of the drill mast. The adjustable leg at the bottom of the drill mast is described below in conjunction with FIG. 10 .
[0049] In one embodiment, the power takeoff 902 can power a hydraulic pump (which can be coincident therewith as shown in FIG. 2 ), fluid flows along the path indicated by the dashed line to an oil reservoir 904 . Hydraulic fluid flows from the oil reservoir 904 along a dashed line to a control 906 . Hydraulic fluid flows from the control 906 via lines 916 to the drill motor 908 . In one embodiment, the drill motor 908 can be a hydraulic motor. The power system for the drill can be configured in different embodiments as will be evident to those of ordinary skill in the art. The present invention is not limited by the way in which the drill is configured on the ATV or the power system used to power the drill motor from an ATV engine.
[0050] FIG. 10 shows a mobile drill powered by an all terrain vehicle (ATV) power takeoff according to one embodiment of the invention. With reference to FIG. 10 , a mobile drill is shown generally at 1000 . A coordinate system (X,Y,Z) is indicated within FIG. 10 , wherein the XY plane represents a level surface and the Z axis is perpendicular thereto. The mobile drill is positioned on the ground 1004 , which need not be level, since the drill mast can be self-aligned.
[0051] The mobile drill includes an ATV 1002 configured with a drill mast 1008 , the drill mast 1008 is movably coupled to the ATV at 1010 for self-alignment. A drill motor 1012 is mounted on a carriage 1014 . The carriage 1014 is slidingly disposed on the drill mast 1008 . The carriage 1014 is coupled to a flexible member 1016 , such as a chain. Flexible member 1016 travels over sheave 1018 and is received by a winch 1020 . The winch 1020 is used to regulate a height of the drill motor 1012 relative to the ground 1004 as the hole 1006 is being drilled as well as after the hole has been drilled. The winch 1020 is used to retract the drill bit and associated parts that end up down-hole after drilling. The winch 1020 can be hydraulically operated in one or more embodiments or it can be manually operated in other embodiments.
[0052] An adjustable leg 1051 provides contact with the ground and can include a contact pad 1052 . The adjustable leg can be manually operated utilizing a threaded rod or the adjustable leg can be power assisted. One method of providing power assist is to employ a hydraulic cylinder at 1051 to press the contact pad 1052 into contact with the ground 1004 , providing stability to the drill mast. The adjustable foot assists during removal of the drill from the hole during retraction by providing vertical rigidity to the system.
[0053] In one embodiment, an ATV transmission or sub-transmission at 1022 is equipped with a power takeoff 1024 . In one embodiment, wherein a hydraulic motor is used as the drill motor 1012 , the power takeoff 1024 is coupled with fluid reservoir 1028 by lines 1026 , and with a control 1032 , by lines 1030 . Hydraulic fluid at high pressure is supplied via line 1036 to the drill motor 1012 . A low pressure hydraulic return line is not shown in order to keep the figure uncluttered. A reverse direction can be achieved within the hydraulic motor by reversing a direction of fluid flow through the motor with dual lines or a control valve can be incorporated into the hydraulic motor 1012 to provide a reverse function.
[0054] The control 1032 can embody the functionality described in conjunction with FIG. 8 , controlling the drill motor thereby. A remote control device 1040 can be used in conjunction with control 1032 to provide wireless control of the drill operations and control of a speed of an ATV engine. Since the drill motor is powered by diverting power from the ATV engine (utilizing the power takeoff) it can become necessary to regulate the speed of the ATV engine during drilling. The speed of the ATV engine can be controlled by an ATV throttle 1034 . In such an embodiment; it can be advantageous to mount the control 1032 on the opposite side of the ATV, proximate with the throttle 1034 . In another embodiment, the ATV engine speed can be maintained with a governor; thereby, maintaining a continuous ATV engine speed. The methods of control taught herein can be used in combination and are not mutually exclusive. For example, a wireless control can be configured along with a governor to maintain constant ATV engine speed.
[0055] In another embodiment, a power takeoff package (similar to the description accompanying FIG. 8 ) can be provided at 1028 , which would include an integration of controls, hydraulic fluid reservoir, etc. The hydraulic pump could also be combined therein as described in conjunction with FIG. 7 .
[0056] In one embodiment, the drill mast is constructed from a three inch square steel tube with a wall thickness of 0.120 inch. In one embodiment, the length of the drill mast is seven feet four inches. In one embodiment, when the drill mast is mounted on an Artic Cat 250 or 300 ATV or a Suzuki LT-F4WDX, LT-F4WD (e.g., 250, 300 & King Quad) ATV the top of the drill mast is eight feet two inches above the surface of the ground 1004 .
[0057] Many different types of drilling can be performed with the mobile drill according to various embodiments of the invention. For example, the mobile drill can be used for rock coring, mud rotary drilling, solid stem auger drilling, hollow stem auger drilling, including standard penetration test (SPT) driven impact sampling, etc.
[0058] In one embodiment, directed to hollow stem auger drilling, drill sections that are two and one half feet in length are used. In one or more embodiments, the drill is a hollow auger design. A hollow auger drill bit head is a design that typically has four teeth disposed around the perimeter. Two of the teeth point toward the interior of the hollow auger and two teeth point toward the exterior of the hollow auger. Configured as described above, the mobile drill is capable of drilling to and taking standard penetration test (SPT) samples at depths of thirty to thirty five feet in dense soils and fifty to sixty feet in softer soils. In one embodiment the hydraulic pump powered by the power takeoff generates 3,000 pounds per square inch of pressure with a volume flow of 9.8 gallons per minute. SPT samples will be described in conjunction with FIG. 13 . The low weight of an ATV provides a mobile drill that is light enough to pass over a seeded lawn without inflicting damage thereto, while still having sufficient power to drill to the desired depths.
[0059] A sheave 1042 is rotateably coupled with a motor 1044 . The sheave 1042 is used to raise an impact hammer which can be used to drive a SPT sample tube into the ground as will be described in conjunction with FIG. 13 . In one embodiment, the motor 1044 can be a hydraulic motor that is also controlled with control 1032 and/or control 1039 . The motor 1044 can be supplied with hydraulic fluid via lines 1040 . The ground 1004 need not exist as a flat plane. The drill contains the capability of self-aligning the mast with vertical by providing rotation about at least one axis.
[0060] FIG. 11A illustrates rotation of a drill mast about a Y axis according to one embodiment of the invention. In this example, the Y axis has been arbitrarily chosen to be parallel with an axis passing through an ATV axel. With reference to FIG. 11A , a drill mast 1011 is rotateably coupled with a plate 1010 . The drill mast 1011 pivots about a Y axis at point 1018 . In one embodiment, a channel is provided at 1019 and a lock mechanism is indicated at 1020 . A lock mechanism includes a threaded bolt and nut that can be tightened; thereby, fixing the angle β indicated at 1026 . In one embodiment, the drill mast 1011 can rotate approximately 110 degrees relative to plate 1010 about point 1018 . Another range of adjustment about the Y axis is provided by the rotation of plate 1010 about point 1014 , making an angle α indicated at 1024 . In one embodiment, plate 1010 can rotate approximately ninety degrees relative to ATV frame 1012 about point 1014 . Rotation of plate 1010 relative to the ATV frame 1012 on axis 1014 allows the drill mast to be aligned even though the ATV may be placed on uneven ground.
[0061] FIG. 11B illustrates rotation of a drill mast about an X axis according to one embodiment of the invention. In this example the X axis has been arbitrarily chosen to be parallel with a longitudinal axis of an ATV. With reference to FIG. 11B , rotation of the drill mast about the X axis is shown generally at 1150 . A drill mast 1011 is shown rotated at angle θ, indicated at 1070 , in order to align the drill mast with the vertical Z axis. In one embodiment, rotation about the X axis is accomplished with a mechanism consisting of two concentric cylinders. An inner cylinder 1162 can be fixedly attached to the drill mast 1011 . A second cylinder 1160 can be fixedly attached to bracket 1010 . A locking mechanism can be employed to fix the rotation of 1162 relative to 1160 ; thereby, fixing angle 1070 . Various locking mechanism can be configured to fix the rotation of 1162 relative to 1160 , such as bolt and nut clamp mechanisms. Gears can be provided to facilitate adjustment of the angle at 1070 by allowing precise rotation of the drill mast 1011 about axis 1164 .
[0062] In one embodiment, the drill mast can be rotated to point sideways or in an upward direction in order to drill holes that are not vertically orientated. No limitation is placed on the orientation of the drill mast or the way in which the self-alignment is accomplished. For example, structures other than those shown in the figures can be employed to articulate the drill mast. In one embodiment, the axial pivots shown in the figures can be replaced with a ball and socket clamp. In one embodiment, the drill mast is attached to the “ball” and the “socket” is fastened to the drill platform. In one embodiment, the socket is configured with a clamp, such that when the clamp is loosened the drill mast can be articulated. When the desired position of the drill mast is achieved the clamp is secured; thereby, fixing the orientation of the drill mast. Other structures can be created to provide an articulated drill mast and are all within the intended scope of embodiments of the invention.
[0063] In one or more embodiments, the drill mast can be released from the all terrain vehicle (ATV) while still receiving power from the ATV. When the drill mast is separated from the ATV, the drill mast can be supported by a drill mast stand, such as, but not limited to, a tripod, a frame, etc. The drill can then be used to drill holes as previously described, employing various drilling methods, such as but not limited to rock coring, mud rotary drilling, solid stem auger drilling, hollow stem auger drilling, etc. Separated from the ATV, the drill mast can be maneuvered into places that the ATV could not easily go or go at all, such as a basement of a building. If the space is confined, the drilling can proceed without the exhaust from the ATV being proximate to the operator during the drilling operation.
[0064] FIG. 12 shows a mast extension according to one embodiment of the invention. With reference to FIG. 12 , a mobile drill is shown generally at 1200 . A drill motor is mounted on a carriage 1214 . The carriage 1214 is slidingly disposed on a drill mast. A drill mast extension 1202 is mounted at the top of the drill mast. The drill mast extension has a forward sheave 1204 and a rear sheave 1206 . The drill mast extension and the sheaves 1204 and 1206 are used in conjunction with a winch to lift an impact hammer 1322 from point 1324 ( FIG. 13 ) above the top of the drill bit 1302 ( FIG. 13 ). With reference back to FIG. 12 , in one embodiment, a winch used to lift the impact hammer includes a motor 1244 and a sheave 1242 . In one embodiment, the motor can be a hydraulic motor powered by a power takeoff that obtains power from an ATV engine. A flexible cord, such as a rope or similar member (not shown) is attached to point 1324 ( FIG. 13 ) and passes up over the first sheave 1204 across the rear sheave 1206 and is received on sheave 1242 , wherein several wraps are made around the sheave 1242 . The motor 1244 is engaged and the rope is wrapped onto the sheave 1242 raising the impact hammer thereby ( 1322 FIG. 13 ). In one embodiment, a hemp rope having a 0.75 inch outer diameter is used.
[0065] FIG. 13 illustrates driving an impact hammer according to one embodiment of the invention during standard penetration test (SPT) sampling. With reference to FIG. 13 , when the hole has been drilled to the desired depth by a drill bit 1302 having flutes 1304 , drill bit head 1306 , and drill teeth 1308 , the carriage 1214 ( FIG. 12 ) can pivot off to the side; thereby, allowing an impact hammer 1322 to drop down and contact a sample tube extension member 1314 when the rope is released from sheave 1242 ( FIG. 12 ). The sample tube extension member is fastened to a sample tube 1310 . The blow imparted from the impact hammer to the sample tube extension member 1320 drives the sample tube into the soil beneath the bottom of the hole drilled by the drill bit 1302 . In response to the blow imparted from the impact hammer, the sample tube 1310 passed through a hole in the drill bit head 1306 , indicated by dashed lines, thus filling the sample tube with a core sample of soil for analysis according to the SPT. The sample tube can be extracted from the hole by retracting the sample tube extension member with the drill motor 1012 , carriage 1014 and winch 1020 ( FIG. 10 ). In a similar fashion, the drill can be retracted from the hole while operating the drill in reverse direction; thereby, facilitating removal of the drill sections. As the drill is withdrawn from the hole, sections of the drill are removed and a length of drill remaining in the hole becomes shorter and shorter until the last piece is removed.
[0066] A technique for minimizing the time required to take SPT samples while drilling a hole involves leaving the sample tube 1310 in the position shown in FIG. 13 while drilling the hole. Such a technique, minimizes the time required to take SPT samples since time is not wasted removing the sample tube and associated sample tube extension members unnecessarily.
[0067] The previous figures have been used to describe a mobile drill, wherein the drill motor is powered by a power takeoff that diverts power from an ATV engine. Other devices can be powered from the ATV power takeoff. These devices include, but are not limited to, a winch for lifting and loading game for transit. A water pump, a saw rig for cutting wood, a bush hog for cutting grass and brush, a soil tiller for plowing soil, etc.
[0068] As used in this description, “one embodiment,” “one or more embodiments,” “an embodiment” or similar phrases mean that feature(s) being described are included in at least one embodiment of the invention. References to “one embodiment” or any reference to an embodiment in this description do not necessarily refer to the same embodiment; however, neither are such embodiments mutually exclusive. Nor does “one embodiment” imply that there is but a single embodiment of the invention. For example, a feature, structure, act, etc. described in “one embodiment” may also be included in other embodiments. Thus, the invention may include a variety of combinations and/or integrations of the embodiments described herein.
[0069] Thus methods and apparatuses for creating a power takeoff on an all terrain vehicle have been described. Devices that draw power from the power takeoff have been described, such as, but not limited to, a mobile drill.
[0070] While the invention has been described in terms of several embodiments, those of ordinary skill in the art will recognize that the invention is not limited to the embodiments described, but can be practiced with modification and alteration within the spirit and scope of the appended claims. The description is thus to be regarded as illustrative instead of limiting. | A method includes adapting an all-terrain-vehicle transmission (ATV) shaft for coupling thereto. The method includes configuring an ATV transmission cover to allow the ATV transmission shaft to pass through the ATV cover, and modifying an ATV sub-transmission shift plate to provide a neutral position for the transmission, wherein the neutral position disconnects power to ATV wheels while providing power to the ATV transmission shaft. An apparatus includes an ATV transmission, having a transmission shaft and transmission housing, wherein the transmission shaft is configured to facilitate coupling thereto; and a transmission shaft extension releaseably connectable with the transmission shaft, the transmission housing having an opening through which the transmission shaft extension can be accessed such that energy can be transferred to an external device. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 12/239,023, filed on Sep. 26, 2008; which claims the benefit of U.S. Provisional applications 60/982,596 filed on Oct. 25, 2007, 61/038,515 filed on Mar. 21, 2008, 61/013,173 filed on Dec. 12, 2007, 61/026,912 filed on Feb. 7, 2008, 61/038,682 filed on Mar. 21, 2008, 61/044,765 filed on Apr. 14, 2008, 60/975,955 filed on Sep. 28, 2007, and 60/976,319 filed on Sep. 28, 2007, which are incorporated by reference as if fully set forth.
TECHNOLOGY FIELD
This application is related to wireless communications.
BACKGROUND
The Third Generation Partnership Project (3GPP) is a collaboration between groups of telecommunications associations to make a globally applicable third generation (3G) wireless communications system.
The UMTS network architecture includes a Core Network (CN), a UMTS Terrestrial Radio Access Network (UTRAN), and at least one user equipment (UE). The CN is interconnected with the UTRAN via an Iu interface.
The UTRAN is configured to provide wireless telecommunication services to UEs, referred to as wireless transmit/receive units (WTRUs) in this application, via a Uu radio interface. A commonly employed air interface defined in the UMTS standard is wideband code division multiple access (W-CDMA). The UTRAN comprises one or more radio network controllers (RNCs) and base stations, referred to as Node Bs by 3GPP, which collectively provide for the geographic coverage for wireless communications with the at least one UE. One or more Node Bs is connected to each RNC via an Iub interface. The RNCs within the UTRAN communicate via an Iur interface.
FIG. 1 is an exemplary block diagram of the UE 200 . The UE 200 may include a radio resource control (RRC) entity 205 , a radio link control (RLC) entity 210 , a medium access control (MAC) entity 215 and a physical (PHY) layer 1 (L1) entity 220 . The RLC entity 210 includes a transmitting side subassembly 225 and a receiving side subassembly 230 . The transmitting side subassembly 225 includes a transmission buffer 235 .
FIG. 2 is an exemplary block diagram of the UTRAN 300 . The UTRAN 300 may include an RRC entity 305 , an RLC entity 310 , a MAC entity 315 and PHY L1 entity 320 . The RLC entity 310 includes a transmitting side subassembly 325 and a receiving side subassembly 330 . The transmitting side subassembly 325 includes a transmission buffer 335 .
The 3GPP Release 6, introduced high-speed uplink packet access (HSUPA) to provide higher data rates for uplink transmissions. As part of HSUPA, a new transport channel, the enhanced dedicated channel (E-DCH), was introduced to carry uplink (UL) data at higher rates.
The MAC sublayer is configured to determine the number of bits to be transmitted in a transmission time interval (TTI) for the E-DCH transport channel. The MAC sublayer may be configured to perform an E-DCH transport format combination (E-TFC) selection process. The relative grant and absolute grants received on the E-RGCH and E-AGCH adjust the maximum allowable E-DPDCH to DPCCH power ration at which a WTRU may transmit.
FIG. 3 shows an overview of the RLC sub-layers. The RLC sub-layer consists of RLC entities, of which there are three types: Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM) RLC entities. An UM and a TM RLC entity may be configured to be a transmitting RLC entity or a receiving RLC entity. The transmitting RLC entity transmits RLC PDUs and the receiving RLC entity receives RLC PDUs. An AM RLC entity consists of a transmitting side for transmitting RLC PDUs and a receiving side for receiving RLC PDUs.
Each RLC entity is defined as a sender or as a receiver depending on elementary procedures. In UM and TM, the transmitting RLC entity is a sender and a peer RLC entity is a receiver. An AM RLC entity may be either a sender or a receiver depending on the elementary procedure. The sender is the transmitter of acknowledged mode data (AMD) PDUs and the receiver is the receiver of AMD PDUs. A sender or receiver may be at either the UE or the UTRAN.
There is one transmitting RLC entity and one receiving RLC entity for each TM and UM service. However, there is one combined transmitting and receiving RLC entity for the AM service.
Both an UM RLC entity and a TM RLC entity use one logical channel to send or receive data PDUs. An AM RLC entity may be configured to use one or two logical channels to send or receive both data PDUs and control PDUs. If only one logical channel is configured, then the transmitting AM RLC entity transmits both data PDUs and control PDUs on the same logical channel.
The AM RLC entity may be configured to create PDUs, wherein, the RLC PDU size is the same for both data PDUs and control PDUs.
Currently, an RLC entity is “radio unaware” or not aware of current radio conditions. However, in the UL direction, an RLC entity may be “radio aware” or aware of current radio conditions, because both RLC and MAC protocols are located in the same node. As a result, an RLC PDU size may be determined based on an instantaneous available data rate.
However, when the RLC entity is designed to be “radio unaware,” the RLC entity generates RLC PDUs of a maximum size. Depending on current radio conditions and a given grant, this may result in the generation of more than one PDU per TTI. Unfortunately, if the generated RLC PDU is larger than a selected E-DCH transport format combination (E-TFC) size, then the generated RLC PDU may be segmented.
Both “radio aware” and “radio unaware” RLCs have advantages and disadvantages. The main disadvantages of radio unaware” are (a) large overhead in case a small fixed RLC PDU size is used and (b) large error rates due to residual hybrid automatic repeat request (HARQ) errors in case MAC segmentation is used with a large fixed RLC PDU size. (Note: residual HARQ error=the transmission of the improved MAC (MAC-i/is) PDU has failed. If there is a large number of segments, the chance that any of the MAC-i/is PDUs carrying a segment fails is larger, thus the RLC PDU error rate increases.)
As stated above, a “radio aware” RLC entity generates RLC PDUs as a function of the E-TFC size of a MAC PDU (transport block size). As a result, there is minimal overhead and low RLC PDU error rate due to residual HARQ errors since the RLC PDUs do not need to be segmented at the MAC. However, a “radio aware” RLC entity may not be able to generate an RLC PDU at a given TTI because the generation of the RLC PDU within a short amount of time may require too much processing power.
A “Radio aware” RLC entity, will generate RLC PDUs that match the transport block size which is optimal for minimizing the RLC PDU error rate due to residual HARQ errors, however the “radio aware” RLC entity will have a much higher overhead for very small E-TFC sizes and a lower overhead for large transport block sizes. Because a “radio aware” RLC generates a large RLC PDU when there is a large E-TFC selection, there are problems when the large RLC PDU needs to be retransmitted and the E-TFC selection decreases in size. Further, the retransmission of the large RLC PDU requires the generation of a large number of MAC segments. As a result, there may be an increase of RLC PDU error rate due to HARQ residual errors.
Accordingly, there exists a need for a method for use in an RLC entity that generates RLC PDUs such that RLC overhead and RLC PDU error rates due to HARQ residual errors are both reduced.
Therefore, methods of selecting the proper RLC PDU size within the specified bounds would be desirable. More specifically, methods to determine when the RLC PDU size should be calculated and which value the RLC PDU size should be set to would be desirable.
SUMMARY
A method and apparatus are used to create RLC PDUs in advance of the E-TFC selection for the MAC PDU that will include this or these RLC PDU(s). The WTRU may be configured to pre-generate RLC PDUs for transmission in a later TTI. This approach has the benefit of avoiding the large peak processing requirement that would exist due to tight delay constraint if any RLC PDU to be included into a MAC PDU had to be created after the determination of the size of this MAC PDU, i.e. after E-TFC selection. The method and apparatus described hereafter allow this benefit while at the same time maintaining most of the time an approximate match between the size of an RLC PDU and the size of the MAC PDU it is included into. Maintaining this approximate match ensures that the RLC PDU error rate due to HARQ residual errors remains low. This approach may be designed as “semi-radio aware” or “radio-aware with delay”.
BRIEF DESCRIPTION OF THE DRAWINGS
A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawing wherein:
FIG. 1 is an exemplary block diagram of the UE;
FIG. 2 is an exemplary block diagram of the UTRAN;
FIG. 3 shows an overview of the RLC sub-layers;
FIG. 4 shows a wireless communication system including a plurality of WTRUs, a Node-B, a CRNC, an SRNC, and a core network;
FIG. 5 is a functional block diagram of a WTRU and the Node-B of the wireless communication system of FIG. 4 ;
FIG. 6 is a block diagram of a method for use in a wireless transmit/receive unit (WTRU) for pre-generating a radio link control (RLC) protocol data units (PDUs) for transmission in a later TTI; and
FIG. 7 shows an example of a combination of embodiments for the various steps described in FIG. 6 .
DETAILED DESCRIPTION
When referred to hereafter, the terminology “wireless transmit/receive unit (WTRU)” includes but is not limited to a WTRU, a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a pager, a cellular telephone, a personal digital assistant (PDA), a computer, or any other type of user device capable of operating in a wireless environment. When referred to hereafter, the terminology “base station” includes but is not limited to a Node-B, a site controller, an access point (AP), or any other type of interfacing device capable of operating in a wireless environment.
FIG. 4 shows a wireless communication system 400 including a plurality of WTRUs 410 , a Node-B 420 , a CRNC 430 , an SRNC 440 and a core network 450 . As shown in FIG. 4 , the WTRUs 410 are in communication with the Node-B 420 , which is in communication with the CRNC 430 and the SRNC 440 . Although three WTRUs 410 , one Node-B 420 , one CRNC 430 , and one SRNC 440 are shown in FIG. 4 , it should be noted that any combination of wireless and wired devices may be included in the wireless communication system 400 .
FIG. 5 is a functional block diagram 500 of a WTRU 410 and the Node-B 420 of the wireless communication system 400 of FIG. 4 . As shown in FIG. 5 , the WTRU 410 is in communication with the Node-B 420 and both are configured to perform a method for selecting an RLC PDU size.
In addition to the components that may be found in a typical WTRU, the WTRU 410 includes a processor 415 , a receiver 416 , a transmitter 417 , and an antenna 418 . The processor 415 is configured to perform a method for selecting an RLC PDU size. The receiver 416 and the transmitter 417 are in communication with the processor 415 . The antenna 418 is in communication with both the receiver 418 and the transmitter 417 to facilitate the transmission and reception of wireless data.
In addition to the components that may be found in a typical base station, the Node-B 420 includes a processor 425 , a receiver 426 , a transmitter 427 , and an antenna 428 . The receiver 426 and the transmitter 427 are in communication with the processor 425 . The antenna 428 is in communication with both the receiver 426 and the transmitter 427 to facilitate the transmission and reception of wireless data.
Hereinafter, the terminology “transport block” may refer to any of the following: a MAC-e PDU, MAC-i PDU, MAC-es PDU, a MAC-is PDU, or a MAC PDU. The terminology “number of bits in a transport block” or “selected transport block (TB)” is used to refer to any of the following quantities: the total size of the transport block (or “transport block size”); the total size of the transport block, minus the number of bits required for MAC header; the number of bits available to the MAC-d flow or logical channel to which the RLC PDU belongs, according to the E-DCH transport format combination (E-TFC) selection procedure; the number of bits available to a combination of MAC-d flows or logical channels, according to the E-TFC selection procedure; and the number of bits requested from the given logical channel as part of the E-TFC selection procedure.
FIG. 6 is a block diagram of a method 600 for use in a wireless transmit/receive unit (WTRU) for pre-generating a radio link control (RLC) protocol data units (PDUs) for transmission in a later TTI. Referring to FIG. 6 , the WTRU performs the calculation of RLC PDU size (or the size of the data field of the RLC PDU) and creation of RLC PDUs at a predetermined time 610 . The WTRU performs the serving grant update procedure, or uses the outcome of the latest serving grant update 620 . The WTRU calculates a “number of bits in transport block” (G) 630 based on the outcome of the serving grant update procedure and possibly other factors. The WTRU may then calculate the RLC PDU size (S) 640 based on the number of bits in transport block and possibly other factors and parameters. The WTRU may then be configured to update the amount of data if outstanding RLC PDUs 660 . Next the WTRU may be configured to determine if additional RLC PDUs may be created based on the amount of data in outstanding RLC PDUs determined, the amount of data in a new RLC PDU if such RLC PDU would be created, and the limit on the total amount of data in outstanding RLC PDUs 670 . If the WTRU determines that no additional RLC PDU may be created, the WTRU may refrain from creating an RLC PDU and wait for the next time the procedure will be executed. Otherwise, the WTRU may be configured to create an additional RLC PDU 680 . The WTRU may then be configured to check if there is still available data (in RLC SDUs) to create RLC PDUs from 690 . If this is the case then the WTRU may the configured to update the amount of data in outstanding RLC PDUs. Otherwise the WTRU may be configured to wait for the next time the procedure is executed. It should the noted that prior to restarting the serving grant update procedure, to save time the WTRU may be configured to check at this point if there is any available data to create RLC PDUs from. If there is no data to create the WTRU may be configured to could skip the wait for the next time of execution.
The following embodiments, describing the time when the RLC PDU size should be calculated (step 610 ), may be used in “combination”, in the sense that the calculation could take place if any of these events takes place. In a first embodiment, the WTRU may be configured to determine the RLC PDU size periodically, for example, on a transmission time interval (TTI) basis, or every N TTIs. The WTRU may also be configured to determine the RLC PDU size every time E-TFC selection occurs. The WTRU may also be configured to determine the RLC PDU size every time a new RLC PDU is created from the segmentation and/or concatenation of RLC service data units (SDUs). The WTRU may also be configured, to determine the RLC PDU size every time the RLC receives new data from higher layers (i.e. new RLC SDUs), or every time the serving grant is updated. The WTRU may also be configured to determine the RLC PDU size based upon an active set update procedure. Optionally, the RLC PDU size may be determined whenever the serving cell changes, or upon setup, configuration or reconfiguration of the radio bearer, transport channel or physical channel. The RLC PDU sizes may be calculated upon reception of the minimum/maximum values from RRC signaling.
Alternatively, the WTRU may be configured to determine the RLC PDU size based on a triggering event. In one embodiment, the WTRU may be configured to determine the RLC PDU size when changes occur in the available number of bits in a transport block, the E-DCH transport format combination index (E-TFCI), the WTRU power headroom, or the serving grant. The amount of change necessary to qualify as a triggering event may be based on a predetermined threshold.
Alternatively, the WTRU may be configured to update the information used in the calculation of the RLC PDU size at every E-TFC selection in which data from this logical channel is included in the MAC-i PDU. In another alternative the WTRU may be configured to update the information used in the calculation of the RLC PDU size at every E-TFC selection in which the HARQ processes are configured to transmit scheduled data and/or non-scheduled if the RLC entity is carrying scheduled flows or non-scheduled flows respectively. Or the WTRU may be configured to update the information used in the calculation of the RLC PDU size at every E-TFC selection in which data from the MAC-d flow of the logical channel is included in the MAC-i PDU or in which the MAC-d flow of the logical channel is allowed to be multiplexed with.
Optionally, the WTRU may be configured to determine the RLC PDU size when one of the following quantities changes by more than a certain value, or becomes lower than a threshold, or becomes higher than a threshold, the quantities including: 1) the measured path loss, measured received signal code power (RSCP) or measured common pilot channel (CPICH) Ec/No to the serving cell, and the WTRU transmission power; 2) the error rate of the nth HARQ transmission (for any n) or the average error rate over all HARQ transmissions) the HARQ transmission delay (time between the initial transmission of the transport block and its successful acknowledgment); 3) the total RLC PDU transmission delay (HARQ transmission delay plus the time between RLC PDU creation and transmission); 4) the residual HARQ error rate (i.e. the probability that a HARQ failure occurs) or the number of HARQ failures; 5) the percentage or number of RLC PDUs that have needed retransmissions; 6) the downlink channel quality perceived by the WTRU, or the reported channel quality indicator (CQI); 7) the number or percentage of “UP” transmit power control (TPC) commands received from the network within a certain time period, possibly conditioned on the WTRU transmitting above a certain absolute transmission power) the number of RLC retransmissions required to successfully transmit an RLC PDU) the percentage or number of RLC SDUs that have been discarded; or 8) any function (e.g. average) of one or a combination of the above quantities.
Alternatively, the WTRU may be configured to determine the RLC PDU size when a hybrid automatic repeat request (HARQ) failure occurs (all HARQ transmissions for a transport block fail), or whenever the number or HARQ retransmission required for successful delivery exceeds a threshold, or a configured number of such events occurs. In another alternative, the WTRU may be configured to calculate the RLC PDU mm when, an RLC PDU needs to be retransmitted, or a configured number of RLC retransmissions occur or a configured percentage of RLC PDUs are retransmitted. In yet another embodiment, the RLC PDU size may be recalculated when an RLC PDU exceeds the number of retransmission or the discard timer expires or a configured number or percentage of RLC PDU/SDUs are discarded. The RLC PDU size may also be calculated when a timer has expired. The value of this timer may be configurable. The RLC PDU size may be calculated by the MAC layer and provided to the RLC layer on a TTI basis or on a periodic basis. Alternatively, the RLC layer may calculate the RLC PDU size based on information from the MAC layer.
In one embodiment, the RLC PDU size is set to the “number of bits in transport block” calculated in step 630 , or is set to a function thereof. In other words, the size of data field of the RLC PDU is set so that the size of the complete RLC PDU (including the header) matches the “number of bits in transport block”. The size may be re-adjusted if the value is higher than a maximum or lower than a minimum as described later. The calculation of the “number of bits in transport block” depends on whether the logical channel which the RLC PDU belongs to belongs to a scheduled flow or a non-scheduled flow.
For logical channels that belong to scheduled flows, the “number of bits in a transport block” may refer to the highest payload that may be transmitted based on the scheduled (serving) grant and available power, (for example, the WTRU uses the Min{Maximum E-TFC that can be sent by the WTRU according to E-TFC restriction procedure, the highest payload that could be transmitted according to the serving grant and the selected power offset}); the highest payload that could be transmitted according to the serving grant only; the highest payload that could be transmitted according to the serving grant and selected power offset, without taking into consideration the required transmit power versus the maximum WTRU transmit power (i.e. assuming that the available WTRU transmit power is always sufficient); and the highest payload that could be transmitted considering the scheduled grant (SG) and maximum WTRU transmit power, (for example, the WTRU uses the Min{Maximum E-TFC that can be sent by the WTRU according to E-TFC restriction procedure, Highest payload that could be transmitted according to the serving grant, without taking into consideration the selected power offset}). The “highest payload that could be transmitted according to the serving grant” may also be referred to as the “maximum amount of data allowed to be transmitted by the applicable current grant for the current TTI”.
The “number of bits in a transport block” may include any of the combinations described above minus the size of the MAC-i/is header. It may also include any of the combinations described above minus the size of the scheduling information (SI) field, if this field is transmitted.
When referred to hereafter, the selected power offset corresponds to the power offset from the HARQ profile of the MAC-d flow that allows highest priority data to be transmitted, or in the case where more than one MAC-d flow allows data of the same highest priority to be transmitted it corresponds to the power offset of the MAC-d flow selected by implementation. Alternatively, the power offset can refer to the power offset from the HARQ profile of the MAC-d flow to which the logical channel belongs to.
When referred to hereafter the value of scheduled grant (SG) may refer to the Serving_Grant value provided by the Serving Grant Update function or alternatively to the scaled down serving grant in the case where 10 ms TTI is configured and the TTI for the upcoming transmission overlaps with a compressed mode gap.
In the case of initial transmission where no E-TFC selection has been performed yet or if no E-TFC selection has taken place for a given amount of time the WTRU may perform one or a combination, of the following: 1) for logical channels belonging to a scheduled flow. Use the value of the Information Element (IE) “Serving Grant value” if provided in the RRC message. This IE is provided by the network and it is used as an initial grant when E-DCH is configured, otherwise the serving grant is initially set to zero. 2) For logical channels belonging to a non-scheduled flow—the WTRU can simply use the non-serving grant as an initial value to start creating RLC PDUs. 3) When no initial Serving Grant is configured (i.e. IE “Serving Grant value” is not provided) or alternatively always for the above mentioned situation, the size of the RLC PDU can be determined using one or a combination of the following values: i) determine size and create RLC PDU at last minute for the current and next TTI(s) only for initial transmission, using the current E-TFC or “number of bits in a transport block” (i.e. determined at the given TTI); ii) RLC PDU size is determined to be of minimum RLC PDU size, or multiple of minimum size, or maximum RLC PDU or max/N; 4) the RLC PDU size is chosen from of the minimum set E-TFC sizes. For instance, the WTRU may choose fire smallest value allowed or the largest value, 5) RLC uses a pre-configured value specified by the network or configured in the WTRU.
In an alternative embodiment, the “number of bits in a transport block” may be one or any combination of: 1) the “number of bits in a transport block” which will contain the RLC PDU being created (this would imply that the UE never creates more RLC PDUs than what can be delivered at the current TTI); 2) the “number of bits in a transport block” resulting from an E-TFC selection determined one or more TTI's earlier. The number of TTI's the transport block (TB) size is determined in advance may be configurable or may be based on WTRU capabilities. 3) The average of the “number of bits in a transport blocks” resulting from E-TFC selection that have been calculated in earlier or this TTI. In this case the resulting TB size may be quantized to match an allowed E-TFC size. The averaging period may be configurable. 4) The “number of bits in a transport block” that may be transmitted if E-TFC selection took place at the time of calculation (even if it is not actually taking place), given certain assumed conditions in terms of serving grant, WTRU power headroom, non-scheduled grants, and other parameters used during E-TFC selection procedure. These assumed conditions may be based on: i) the currently prevailing values of the serving grant, WTRU power headroom, non-scheduled grants, and other parameters; ii) values of the serving grant, WTRU power headroom, non-scheduled grants, and other parameters, that have been experienced in the past; iii) values or the serving grant, WTRU power headroom, non-scheduled grants, and other parameters, that are expected to be realised in the near future given certain measurements (such as path loss, CPICH Ec/No, CPICH RSCP, WTRU transmission power, downlink channel quality, etc.); or iv) any combination or function of the above. 5) The “number of bits in a transport block” as per one of the above definitions, or average thereof, multiplied by a factor and rounded up or down to the next integer or to the closest value from a finite set of possible values. The factor may be larger than 1 or smaller than 1. 6) The “number of bits in a transport block” as per one of the above definitions, or average thereof, multiplied by a “maximum number of MAC segments per RLC PDU” parameter which is either signaled or pre-determined (the actual parameter name could be different); 7) the “number of bits in a transport block” as per one of the above definitions, or average thereof, divided by a “maximum number of MAC-is SDU's per MAC-i PDU” parameter which is either signaled or pre-determined, or an equivalent parameter (the actual parameter name could be different); and 8) any function of the above.
The WTRU may be configured with a minimum size and a maximum size restriction for each RLC PDU. If the RLC PDU size obtained using one of the methods described above is higher than the configured maximum size, then the RLC PDU size is reset to this configured maximum size. Similarly, if the RLC PDU size obtained using one of the methods described above is lower than the configured minimum size, then the RLC PDU size is reset to this configured minimum size.
In one embodiment, the UTRAN 300 may determine the maximum RLC PDU size and communicates the maximum RLC PDU size value to the WTRU 200 using L2 or L3 (RRC) signaling. For example, the UTRAN 300 may configure the WTRU 200 to use a minimum RLC PDU size and a maximum RLC PDU size using the RRC information element (IE) “RLC info.” The signaling of the maximum RLC PDU size value may occur upon radio bearer configuration or radio bearer reconfiguration. Further, the signaling of the maximum RLC PDU size value may occur upon transport channel configuration or transport channel reconfiguration.
Alternatively, the WTRU may be configured to derive the minimum RLC PDU size from a minimum allowed MAC segment size, if such size is defined. For example, the minimum RLC PDU size may be a multiple of a minimum MAC segment size. Alternatively, the minimum RLC PDU size may be a static value that is preconfigured in the WTRU 200 .
Referring back to FIG. 6 , the WTRU may be configured to create a limited number of RLC PDUs. For example in ( 650 ), the WTRU determines a limit on the amount of data in RLC PDUs already created but not yet transmitted (i.e. not yet inserted into a transport block). These PDUs are referred to as “outstanding” RLC PDUs hereafter. Optionally, the amount of data in outstanding RLC PDUs may also include the content of the segmentation entity for the corresponding logical channel. In one embodiment, the WTRU may be configured to create a limited number of new RLC PDUs, such that the total amount of data in outstanding RLC PDUs does not exceed the predetermined limit. It should be noted that the number of new RLC PDUs created may be zero if the amount of data in outstanding RLC PDUs was already exceeding the limit at the beginning of the procedure. In this case, the WTRU does not create additional RLC PDUs, but does not discard already created RLC PDUs. The predetermined data limit may be pre-defined, signaled by higher layers, or based on the current E-TFC or current number of bits in a transport block for the logical channel (as indicated by the MAC layer), or size of new RLC PDUs that would be created. In one embodiment, the limit in step may correspond to the amount of data that could be transmitted from this logical channel, multiplied by a pre-defined factor given current grant and power conditions. In other words, the limit corresponds to the maximum amount of data allowed to be transmitted by the applicable current grant (scheduled or non-scheduled) for the current TTI which has been calculated in step 630 .
Alternatively, the WTRU may be configured to create as many new RLC PDUs as possible given the amount of buffered data (RLC SDUs). Or the WTRU may be configured to create a maximum number (Nc) of new RLC PDUs (up to the number possible given the amount of buffered data). This maximum number may be pre-defined, signaled by higher layers, or based on the current E-TFC or current number of bits in a transport block for this logical channel (as indicated by the MAC layer).
In another alternative, the WTRU may be configured to create a limited number of new RLC PDUs based on a predefined amount of data expressed in bits or bytes. This amount may be pre-defined, signaled by higher layers, or based on the current E-TFC or current number of bits in a transport block for this logical channel or MAC-d flow (as indicated by the MAC layer). For instance, the amount may correspond to the amount of data that could be transmitted from this logical channel or MAC-d flow (times a factor) given current grant or power conditions.
Optionally, logical channels which belong to non-scheduled flows may not have any restrictions on the number of PDUs they create in advance. This may be the case when the RLC PDU size determination is based on the value of the non-serving grant only. In this scenario, RLC PDUs of size corresponding to the non-serving grant (optionally minus the MAC header part) can always be created.
FIG. 7 shows an example of a combination of embodiments for the various steps described in FIG. 6 . The different steps shown are achieving the same tasks as the corresponding steps in FIG. 6 , but are more specific.
In step 740 corresponding to step 740 , the RLC EDU size S is determined as the maximum between a minimum RLC PDU size and the minimum between a maximum RLC PDU size and the number of bits in transport block (G) determined in step 730 (corresponding to step 630 ). In step 750 , the maximum amount of data in outstanding PDUs (M) is calculated as a constant (such as 4) times the number of bits in transport block (G) determined in step 730 . In step 770 , the maximum amount of data in outstanding PDUs (M) is compared to the sum of the amount of data in outstanding PDUs (D) and the size S determined in step 740 . Alternatively, it could be also compared to the sum of D and a size T<S, if there is not enough available data in RLC SDUs to create an additional RLC PDU of size S. In step 710 , the WTRU waits until the next TTI before executing the procedure the next time.
Although features and elements are described above in particular combinations, each feature or element can be used alone without the other features and elements or in various combinations with or without other features and elements. The methods or flow charts provided herein may be implemented in a computer program, software, or firmware incorporated in a computer-readable storage medium for execution by a general purpose computer or a processor. Examples of computer-readable storage mediums include a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs).
Suitable processors include, by way of example, a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), and/or a state machine.
A processor in association with software may be used to implement a radio frequency transceiver for use in a wireless transmit receive unit (WTRU), user equipment (UE), terminal, base station, radio network controller (RNC), or any host computer. The WTRU may be used in conjunction with modules, implemented in hardware and/or software, such as a camera, a video camera module, a videophone, a speakerphone, a vibration device, a speaker, a microphone, a television transceiver, a hands free headset, a keyboard, a Bluetooth® module, a frequency modulated (FM) radio unit, a liquid crystal display (LCD) display unit, an organic light-emitting diode (OLED) display unit, a digital music player, a media player, a video game player modules an Internet browser, and/or any wireless local area network (WLAN) or Ultra Wide Band (UWB) module. | A method and apparatus are used to create RLC PDUs in advance of the E-TFC selection for the MAC PDU that will include this or these RLC PDU(s). The apparatus may be configured to pre-generate RLC PDUs for transmission in a later TTI. This approach avoids the large peak processing requirement due to the tight delay constraint if any RLC PDU to be included into a MAC PDU had to be created after the determination of the size of this MAC PDU, i.e. after E-TFC selection. The method and apparatus maintain an approximate match between the size of an RLC PDU and the size of the MAC PDU it is included into. Maintaining this approximate match ensures that the RLC PDU error rate due to HARQ residual errors remains low. This approach may be designed as “semi-radio aware” or “radio-aware with delay”. | 7 |
This is a continuation of application Ser. No. 08/298,371 filed on Aug. 30, 1994, now abandoned; which is a continuation of U.S. Ser. No. 08/068,602 filed on May 27, 1993, now abandoned, which is a continuation of U.S. Ser. No. 07/937,439 filed on Aug. 27, 1992, now abandoned; which is a continuation of U.S. Ser. No. 07/837,653 filed Feb. 14, 1992, now abandoned; which is a continuation of U.S. Ser. No. 07/730,567 filed Jul. 15, 1991, now abandoned; which is a continuation of U.S. Ser. No. 07/634,927 filed Dec. 26, 1990, now abandoned; which is a continuation of U.S. Ser. No. 07/517,553 filed Apr. 24, 1990, now abandoned; which is a continuation of U.S. Ser. No. 07/406,879 filed Sep. 13, 1989, now abandoned; which is a continuation of U.S. Ser. No. 07/296,407 filed Jan. 9, 1989, now abandoned; which is a continuation of U.S. Ser. No. 07/136,553 filed Dec. 22, 1987, now abandoned.
This invention relates to a method of manufacturing a plastic pressure container having a seamless extruded plastic body portion and plastic end closures. In one embodiment of the pressure container, one of said closures is adapted for receiving a manually operated valve unit. The body portion is formed by an extrusion process and the closures by injection or other molding processes.
BACKGROUND
Pressure containers have in the past been largely constructed of a metal body and metal end closures. In the instance of the pressure container being an aerosol container, one end closure is contoured to receive and have crimped thereto a metal component referred to in the art as a mounting cup, which cup has affixed thereto a manually-actuable valve.
The metal body of the container is seamed along its length in the case of steel containers. This results, though avoidance is attempted, in an inner shape that is not truly cylindrical, the seam providing a discontinuity in the "true round" shape. In the case of aerosol aluminum containers, though seamless, the thin wall of the container is readily dented and a deviation from the "true round" results.
For many applications of an aerosol package system, for example, where a piston traversing the inner wall of the container body is a component of the package, a deviation from "true round" is undesirable. Where there is deviation from the "true round" a breakage in the seal between the inner wall of the container and the piston will occur with a concomitant loss or decrease in the efficiency of the discharge of the contents of the pressurized container.
Additional shortcomings of metal containers, often manufactured away from the site where the product is introduced into the container, is the shipment of the container to the filling site. Moreover, corrosion may be a problem necessitating a coating of the metal in order to make the inner surface of the container compatible with the product to be dispensed, and consequently and additional manufacturing operation.
The deficiencies of metal containers have resulted in an effort by marketers to replace the metal container with a plastic container.
Plastic pressure container have to date been manufactured by injection molding or blow molding processes. Both processes have serious drawbacks.
When injection molding a container, it is necessary that the body portion of the container have a draft or slope in order to eject the container from the mold. Further, and particularly with containers having a body portion with a length of conventional containers, such as beverage or aerosol containers, it is extremely difficult to fill the cavity defining the body portion of the container with the consequence that channeling or incomplete fill of the injection mold cavity results. As a consequence, in order to properly fill the cavity it is essential to use excessive temperature and pressure conditions, which result in a differential temperature profile over the length of the cavity and consequently stress and strain, warping and embrittlement of the molded container. Additionally, it is difficult to hold the core defining the inside wall of the body portion of the container properly centered with the result that the container wall is of varying thickness. Since permeation from within or external to the container is a function, among others, of the wall thickness, to compensate for a shift from true center of the cavity core, the injection mold cavity must be designed to provide a minimum wall thickness throughout. To assure the necessary minimum thickness necessarily results in a design of a wall thickness excessive to that necessary to properly contain the product.
Blow molding, necessarily, results in the wall of the pressure container being of uneven thickness since the pressure and temperature variations on the surface of the parison or preform is not uniform. Moreover, molecular weight variation in the parison and pre-form foreclose formation of a container having a substantially uniform wall thickness. Thus, as in an injection molding process, excessive amounts of plastic must be used in order to assure the minimum wall thickness necessary throughout the container to properly contain the product to be dispensed. Obviously, a variation in the wall thickness precludes formation of a body portion having an inner surface that is "true round" and consequently the container lacks usefulness as a container where the "true round" is essential to the dispensing of the product.
Further, in blow molding a container the end closures necessarily must be formed of the same plastic material. Further, in blow molding design, flexibility is limited. Moreover, in an aerosol-type container, where the top opening is smaller in diameter than the body portion of the container it is impossible to position a piston having a diameter substantially the same as the inside diameter of the container with the container.
SUMMARY OF THE INVENTION
Broadly stated, this invention comprises a pressure container having an extruded plastic body portion and plastic end closures for the body portion, each end closure having a recess portion for receiving the respective ends of the body portion. In a preferred embodiment one of the closures is adapted to receive a conventional aerosol valve having a mounting cup for clinching onto the said closure. In a still further preferred embodiment, the non-valved closure has a port for bottom gassing of the container when the product to be discharged and the propellant are separated by a piston.
The present invention will be more clearly understood by referring to the drawings herein and the discussion relating thereto.
IN THE DRAWINGS
FIG. 1 is a perspective view of the plastic container of this invention with a section through the body portion.
FIG. 2 is an exploded cross-section of the body portion and the valve receiving and bottom end closures of the plastic container of this invention.
FIG. 3 is a vertical cross-section of the plastic container of this invention.
FIG. 4 is a vertical cross-section of the valve receiving end closure of this invention.
FIG. 5 is a vertical cross-section of a further embodiment of the invention.
FIG. 6 is a vertical cross-section of a specific embodiment of an end closure of this invention.
FIG. 7 is a vertical cross-section of a further embodiment of an end closure of this invention.
DESCRIPTION OF THE INVENTION
In FIG. 1, the container generally designated as 10, has a valve receiving end closure 12, a cylindrical body portion 14, and an end closure 16.
As shown in FIG. 2, the body portion 14 is seamless and in the form shown, cylindrical. The body portion should be able to withstand pressures within the container normally attendant to pressurized containers, such as, for example aerosol dispensers.
The body portion 14 is extrusion formed. It has been found that a group of polyethylene terephthalate resins, referred to as barrier resins and marketed under trademarks, such as Selar® PT resins (marketed by E.I. du Pont de Nemours) are suitable materials for the body portion. Specific Selar® PT resins found suitable are Selar® PT and Selar® PT 5270. Another barrier resin, useful in forming translucent body portions are Selar® PA 3426, this resin being an amorphous nylon. It has been found that with the aforementioned Selar® resins, a container having a wall thickness of 0.010-"0.060" is satisfactory to function as the container body under normal aerosol dispenser pressures of 10 to 150 PSI.
Conventional extrusion equipment, not shown, may be used to form the body portion 14. Conventional injection molding equipment, not shown, may be used to form the end closures 12 and 16.
The valve receiving end closure 12 has an annular wall 18 having a bead portion 20 defining an opening 34 for receiving a conventional aerosol valve (not shown) and a shoulder portion 22 having an extending portion 23, the outer surface 24 of the annular wall 18 and the inner surface 26 of the extending portion 22 forming a recess 28 to receive the end portion 30 of the body portion 14. In the base of the recess 28 is an annular undercut 32.
When the end 30 is positioned in the recess 28, the components are spin welded by conventional techniques, the end portion 30 of the body 14 melting and flowing into the undercut 32 to thereby effect a fluid tight seal between the body portion 14 and the end closure 12.
A fluid tight seal between the walls defining the recess 28 and the outer 40 and inner 42 walls of the body portion 14 may also be accomplished through sonic welding of the contiguous surfaces of the recess 28 and the walls 40 and 42 of the body portion 14.
The end closure 16 has an annular upstanding wall 36, traversing which is the domed portion 38. As in end closure 12, closure 16 has an annular upstanding wall 44 and a shoulder 46 having an extending portion 48, the outer surface 50 of the annular wall 44 and the inner surface 52 of the extending portion 48 forming a recess 54 to receive the end portion 56 of the body portion 14. In the base of the recess 54 is an annular undercut 58.
The end closure 16 and the body portion 14 may be joined to form a fluid tight seal in the manner discussed aforesaid in reference to the end closure 12.
An annular bead 70, shown in FIG. 6, may be formed in the undercuts 32 and 58 of the end closures 12 and 16 by melting the end portions of the body portion 14 and effecting a flow of the plastic body portion into the respective undercuts. The bead 70 effects a mechanical joinder between the end closures and the body portion of the container.
The undercuts 32 and 58 in the respective end closures 12 and 16 may be formed, alternatively, in the outside wall of the annular walls 18 and 50 of the end closures 12 and 16, respectively. Moreover, the recesses 28 and 54 of the end closures 12 and 16 may have disposed therein a heat conductive material, such as, metal which will act as a heat sink to transfer heat to the contiguous plastic components and effect a more rapid softening or melting of said contiguous plastic components and consequent formation of the bead 70.
Additionally, a magnetic material may be disposed within the recess 54 (shown in FIG. 7 as 72), which material may function to magnetically affix the aerosol container beneath the surface of a normally floatating medium; for example, beneath the water surface in a water bath testing apparatus.
Moreover, an adhesive material having a melting point below that of the body portion and end closures may be disposed in the respective recesses of the end closures or on the terminal portions of the end closures, which adhesive will melt and flow into the undercuts to form an annular bead, thus effecting a mechanical bonding between the closure and the body portion. Additionally, the adhesive material may contain a magnetic material to serve the function set forth above for said material.
Shown in FIG. 5 is a plastic container assemblage, wherein, in addition to the structure shown in FIG. 3 there is a port 60 and a piston 62 (shown in dotted line as it moves toward the valved end of the container during evacuation of the container contents).
The end closures may be injection molded. It has been found that polyacetal polymers form satisfactory injection molded end closures.
The end closure may be constructed to accommodate varying body portion diameters. As shown in FIG. 4, the bead portion 20 of the valve end closure 12 to which the valve is crimped may be constructed to maintain a standard valve opening by inwardly and upwardly projecting an annular wall 22 from the wall 18 which terminates in the bead 20.
While the invention has been illustrated showing a body portion 14 of cylindrical design, it should be understood that the shape of the body portion is not so limited; the body portion 14 being limited to exclude only shapes incapable of being extrusion formed. Thus, for example, the body portion may be rectangular, triangular, oval, hexagonal, etc. Moreover, the body portion 14 may be formed by coextruding different plastic materials to tailor permeability and other physical properties of the body portion 14.
As with a cylindrically shaped body portion, the inner surface of the extruded body portion is dimensionally uniform throughout the length of the body portion. Consequently, the body portion may more efficaciously function as a container body having a piston traversing its length.
With the subject invention plastic pressure containers may be manufactured which obviate the deficiencies enumerated above that are associated with injection and blow molding processes. Uniform wall thickness and a substantially uniform inner diameter through the entire length of the body portion of the container is readily attainable. Moreover by extrusion forming the body portion and injection molding, for example, of the end closures, a plastic container having end closures of a material dissimilar to the body portion of the container may be readily fabricated. By being able to form the end closures of a material different than the body portion, enables the containe manufacturer to utilize plastic materials in the end closure having the necessary strength characteristics to affix an aerosol valve to the end closure.
Additionally the standard concave shaping of the bottom of the conventional aerosol container is attainable to allow for an undue bulging. When blow-molding a plastic pressure container, the container design must have a spherical shape at the base of the container in order to withstand the pressure. | Broadly stated, this invention comprises a pressure container having an extruded plastic body portion and plastic end closures for the body portion, each end closure having a recess portion for receiving the respective ends of the body portion. In a preferred embodiment one of the closures is adapted to receive a conventional aerosol valve having a mounting cup for clinching onto the said closure. In a still further preferred embodiment, the non-valved closure has a port for bottom gassing of the container when the product to be discharged and the propellant are separated by a piston. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority under 35 U.S.C. §119(e) of U.S. Provisional Application No. 61/174,631 filed on May 1, 2009 and entitled “METHODS AND SYSTEMS FOR ILLUMINATION DURING PHLEBECTOMY PROCEDURES,” which is hereby incorporated herein by reference in its entirety and is to be considered a part of this specification.
BACKGROUND
[0002] The disclosed embodiments relate generally to methods and systems for providing illumination during phlebectomy procedures. Phlebectomy is a standard treatment for varicosities arising from incompetent veins, particularly those below the saphenofemoral and saphenopopliteal junctions. This technique involves the avulsion and removal of the varicose veins through multiple stab incisions made directly over the veins, which are removed using surgical tools, such as hooks and mosquito forceps. Proper location of the veins to be removed is essential for proper situation of the incisions. In general, this is accomplished by preoperative vein location and marking, a procedure generally accomplished with the patient in a standing position so that the veins become engorged with blood due to the action of gravity and thus easily marked; however, the phlebectomy operation is generally conducted with the patient in a supine position. The position of the incompetent veins may shift during the transition from a standing to a supine position, and often further marking is conducted after the patient is placed in the surgical position in an attempt to track these shifts. Once the patient has been marked and incisions have been made along the length of the vein to be removed, the surgeon probes with the surgical implements, such as hooks, to locate the vein.
SUMMARY
[0003] In one embodiment, a method comprises (a) illuminating a blood vessel in a relatively low-light surgical field by inserting a subcutaneous light source into tissue near the blood vessel and to a first location in the tissue underlying the blood vessel, and causing emission of light from the subcutaneous light source while the subcutaneous light source is at the first location, so that light from the subcutaneous light source passes through the tissue near the blood vessel, toward an observer; (b) drawing a portion of the tissue near the blood vessel through an incision in the skin; and (c) illuminating the drawn portion of tissue by activating an external light source in a hands-free manner, thereby facilitating determining whether the drawn tissue is the blood vessel.
[0004] In the method, the blood vessel can optionally be a vein, such as a varicose vein, or a superficial leg vein near the skin surface. The surgical field can optionally be an area at least about 20 cm wide and centered on the subcutaneous light source insertion site, extending at least about 20 cm from the skin surface at the subcutaneous light source insertion site toward an observer (e.g. a surgeon). The method can optionally further comprise, prior to drawing the portion of tissue near the vein, selecting the portion of the tissue based on observing the tissue illuminated by the subcutaneous light source. The external light source can optionally be worn on the surgeon's head and/or activated by a movement of the head (such as a nod of the head). The external light source can optionally be one which is activated without use of the hands or feet, and/or by the surgeon himself or herself without commanding another person to activate an external light source. The external light source can optionally provide broadband or white light in a floodlight fashion in the surgical field.
[0005] In another embodiment, a surgical illumination system comprises a subcutaneous illuminator having an elongate member configured for insertion into subcutaneous tissue. The elongate member has a light emitter near its distal end, and the light emitter is configured to emit light primarily in a generally radial direction, outward and away from a longitudinal axis of the elongate member. The system further comprises an external illuminator configured to illuminate a surgical field in a floodlight fashion. The external illuminator is configured for activation without use of the hands.
[0006] In the system, the external illuminator can optionally be configured to be worn on the surgeon's head and/or activated by a movement of the head (such as a nod of the head). The external illuminator can optionally include an inertial switch or accelerometer to facilitate such activation. The external illuminator can optionally be one which is activated without use of the hands or feet, and/or by the surgeon himself or herself without commanding another person to activate an external illuminator. The external illuminator can optionally provide broadband or white light in a floodlight fashion in the surgical field.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] In the drawings:
[0008] FIG. 1 is a front view of an exemplary subcutaneous illumination apparatus of an illumination system according to one embodiment.
[0009] FIG. 2 is an enlarged view of the region labeled II in FIG. 1 showing an electroluminescent device of the subcutaneous illumination apparatus of FIG. 1 .
[0010] FIG. 3 is a perspective view of an exemplary external illumination apparatus of the illumination system according to one embodiment.
[0011] FIG. 4 is a plan view of the external illumination apparatus of FIG. 3 .
[0012] FIG. 5 is a perspective view of a switch according to one embodiment from the external illumination apparatus of FIG. 3 .
[0013] FIG. 6 is a sectional view of the switch of FIG. 5 in an unactuated condition.
[0014] FIG. 7 is a sectional view similar to FIG. 6 with the switch in an actuated condition.
[0015] FIG. 8 is an exemplary electrical circuit for the external illumination apparatus of FIG. 3 .
[0016] FIG. 9 illustrates the external illumination apparatus of FIG. 3 worn on the head of a user and actuation of the switch via movement of the head of the user.
DETAILED DESCRIPTION
[0017] Methods and systems for providing illumination during phlebectomy procedures are disclosed. The methods and systems can provide subcutaneous illumination for visualization of veins and surrounding tissue and external illumination of material removed through the incisions for identification thereof. More particularly, after the patient has been marked and at least one incision has been made during the phlebectomy procedure, the surgeon attempts to locate the vein through the incisions, which can be difficult when the vein has shifted from the marked positions upon movement of the patient to the supine position. To facilitate vein location, the surgeon can employ an illumination device, such as a subcutaneous illumination device, that provides internal illumination for visually distinguishing the vein from the surrounding tissue. The subcutaneous illumination device can emit light at wavelengths selected to render the appearance of the vein dark, such as black, against a highlighted background of surrounding tissue. The illumination source can be relatively small and concentrated, and the region illuminated by the subcutaneous illumination device can often be viewed best when the room is relatively dark, which can be achieved by turning off or dimming the room lights. After location of the vein inside the body, the surgeon pulls a hook or other surgical implement from the incision and visually inspects material removed therewith for identification of the vein. However, this visual inspection can be difficult when the room is relatively dark for optimized efficacy of the subcutaneous illumination device, and the surgeon can employ an external illumination device that provides external illumination to facilitate the visual inspection.
[0018] One embodiment of the system comprises a subcutaneous illumination apparatus 10 , an example of which is illustrated in FIG. 1 , and an external illumination apparatus 30 , which will be described in detail below. Referring to FIG. 1 , the exemplary subcutaneous illumination apparatus 10 comprises a handle 12 and an illuminator portion 14 housing an electroluminescent device 16 . The handle 12 includes a switch 18 operatively coupled to the electroluminescent device 16 for selectively providing power to the electroluminescent device 16 . The illuminator portion 14 comprises an elongated shaft 20 and a flattened blade or bladelike member 22 at the distal end of shaft 20 . In certain embodiments, the shaft 20 can be of sufficient stiffness to permit the dissection of tissue or the avulsing of veins using the blade 22 . The blade 22 can be sized for insertion into the subcutaneous surgical space through the small stab incisions typically employed in phlebectomy. The blade 22 can optionally be omitted and instead the shaft 22 can comprise a tube or cylinder of less than or equal to 7 French (2.33 mm) diameter along its length, with an insertable length of about 13-14 cm.
[0019] In the illustrated embodiment, the blade 22 or shaft 20 incorporates the electroluminescent device 16 , which is configured to both generate and emit light in a generally radial direction, outward and away from a longitudinal axis of the illuminator portion 14 . Any suitable type of electroluminescent lighting apparatus that can be accommodated within the blade 22 or shaft 20 can be employed as the electroluminescent device 16 . Examples of electroluminescent devices include LED elements and other solid state light emitters. Individual light emitting elements 24 can be assembled into a linear array to form the device 16 , as seen in the enlarged plan view of the electroluminescent device 16 in FIG. 2 . In certain embodiments, the light emitting elements are configured to emit red or yellow light. In other embodiments, the light emitting elements are configured to emit light having a wavelength of less than 610 nm, or in the range of 630 to 670 nm. In other embodiments, the light emitting elements are configured to emit light substantially only in a wavelength or wavelength range that tends to highlight a blood vessel against surrounding tissue when the light is passed through the blood vessel and tissue. In other words, the incident light can cause the vein to appear darker than the surrounding tissue. The light emitting elements can be powered by batteries or other energy storage devices that are housed within the handle 12 , or by an external power supply to which the apparatus 10 can be connected, such as a wall outlet.
[0020] The subcutaneous illumination apparatus 10 shown in FIGS. 1 and 2 and described above is one exemplary embodiment of the apparatus 10 that can be employed with the illumination system. Other types of subcutaneous illumination apparatuses can be employed with the illumination system and for the corresponding methods, including those described in U.S. Patent Application Publication No. 2007/0244371, published Oct. 19, 2007, and the corresponding U.S. patent application Ser. No. 11/732,771, filed Apr. 4, 2007, which are incorporated herein by reference in their entireties; the '371 publication is attached in the Appendix to the present application. Further, the system can employ other types of apparatuses for illuminating or otherwise identifying veins, such as a transdermal illumination apparatus (e.g. the VEINLITE™ available from TransLite LLC of Sugar Land, Tex.), in combination with or instead of the subcutaneous illumination apparatus.
[0021] As mentioned above, the illumination system comprises the external illumination apparatus 30 in addition to the subcutaneous illumination apparatus 10 . While the subcutaneous illumination apparatus 10 provides internal illumination (i.e., illumination internal of the body of the patient) for identifying veins, the external illumination apparatus 30 provides external illumination (i.e., illumination external to the body of the patient) for inspection of the material removed from the patient's body. The external illumination apparatus 30 provides the external illumination without the use of the hands of the surgeon so that the hands remain free for manipulating the subcutaneous illumination apparatus 10 , hooks, and/or other surgical instruments. The illustrated embodiment of the external illumination apparatus 30 achieves hands-free operation via mounting the apparatus 30 on the surgeon's head and actuation of the apparatus 30 in response to movement of the surgeon's head.
[0022] Referring now to FIG. 3 , an exemplary embodiment of the external illumination apparatus 30 comprises a head mount 32 adapted to be worn on the head of the surgeon. The head mount 32 includes a generally circular headband 34 having a front portion 36 corresponding to the surgeon's forehead region, a rear portion 38 corresponding to the back of the surgeon's head, and an adjustable closure 40 for sizing the headband 34 according to the circumference of the head of the surgeon. The headband 34 can further incorporate one or more pads, such as a forehead pad 42 oriented for placement against the forehead that provide cushioning and facilitate a secure fit of the headband 34 around the head of the surgeon. The head mount 32 also comprises a harness 44 in the form of a band coupled to the front portion 36 and the rear portion 38 of the headband 34 and having an arcuate configuration so as to extend over the crown of the surgeon's head. Pads, such as crown pads 46 , can be positioned on the underside of the harness 50 to facilitate a comfortable fit of the harness 44 against the crown of the surgeon's head.
[0023] The headband 34 supports an illumination assembly 50 at the front portion 36 and a power source 52 for the illumination assembly 50 at the rear portion 38 . The illumination assembly 50 comprises an illumination source 54 provided within an illumination source housing 56 and a lens 58 positioned at the front end of the housing 56 . The lens 58 protects the illumination source 54 within the housing 56 and can optionally function as a filter for light emitted by the illumination source 54 . An adjustable mount 60 couples the housing 56 to the headband 34 and includes a pivotable joint 62 at which the housing 56 connects to the mount 60 and about which the housing 56 can pivot for moving the housing 56 and, thereby, the illumination source 54 , in up and down directions. In some embodiments, the mount 60 can be configured for additional adjustment of the housing 56 and/or the illumination source 54 in other directions, such as lateral or side-to-side movement. In certain embodiments, the mount 60 can be configured for adjustment of the housing 56 and/or the illumination source 54 in any direction, such as via a universal or U-joint. The adjustment of the housing 54 and/or the illumination source 54 in the illustrated embodiment is accomplished manually, and other embodiments employ other adjustment methods, such as verbal/speech recognition adjustment to further render the external illumination apparatus 30 hands-free.
[0024] The illumination source 54 can be any suitable device that provides desired external illumination during a phlebectomy procedure. In one embodiment, the desired external illumination is a broad field of white light that sufficiently illuminates a relatively dark room to allow the surgeon to perform the visual inspection of the material removed from the patient. Such light can be provided by any suitable illumination source, including, but not limited to, electroluminescent illumination sources, such as LEDs, and conventional light bulbs, such as fluorescent and incandescent light bulbs. In other embodiments, the desired external illumination can be a broad field of colored (i.e., not white) light that facilitates the visual inspection of the material or a narrow, focused field of white or colored light. In one embodiment, the wavelength(s) of light provided by the illumination source 54 can be selected to aid the surgeon in distinguishing the vein from surrounding tissues, such as fat tissue.
[0025] The power source 52 that provides power to the illumination source 54 in the illustrated embodiment comprises a portable power source in the form of a battery. The battery can be any suitable battery, including replaceable and/or rechargeable batteries. In one embodiment, the battery can be rechargeable and removed from the head mount 32 for coupling to a charger. In another embodiment, the entire external illumination apparatus 30 can be coupled to a charger, such as via a docking station or a cord that connects the battery to a power outlet. The power source 52 can also include a cord or other physical connection that couples the illumination source 54 to an external source of power, either to replace the portable power source or to be used as a back-up in the event that the portable power source becomes depleted during use of the external illumination apparatus 30 .
[0026] A set of wires 70 , 72 electrically connects the power source 52 to the illumination source 54 , and a switch 80 controls the supply of electricity from the power source 52 to the illumination source 54 . As best viewed in FIG. 4 , which is a top view of the external illumination apparatus 30 , the harness 44 of the head mount 32 supports the wires 70 , 72 and the switch 80 . The wire 70 electrically couples the power source 52 to the switch 80 , and the wire 72 electrically couples the switch 80 to the illumination source 54 .
[0027] In the illustrated embodiment, the switch 80 is an inertial switch in the form of an acceleration switch responsive to the movement of the surgeon's (or other wearer's) head. The switch 80 is partially located within a switch housing 82 mounted to the harness 44 . Referring now to FIG. 5 , which is a perspective view of the switch 80 , and FIG. 6 , which is a sectional view bisecting the switch 80 along its longitudinal axis, the switch 80 comprises a casing 84 having, at its rear end, a vent 86 for an interior chamber 88 that receives a ball 90 and a compression spring 92 and, at its front end, a bore 94 that slidably receives a plunger 96 . The plunger 96 extends from within the chamber 88 and through the bore 94 to project beyond the front end of the casing 84 . The compression spring 92 surrounds the portion of the plunger 96 within the chamber 88 and spaces the ball 90 from the plunger 96 when the compression spring 92 is in its natural extended condition shown in FIGS. 5 and 6 . The front end of the plunger 96 functions as a first electrical contact 98 and is electrically coupled to the wire 70 by a conductive leaf spring 100 . The switch 80 further includes an L-shaped arm 102 extending from the front end of the casing 84 and terminating at a second electrical contact 104 linearly aligned with and facing the first electrical contact 98 . The conductive arm 102 couples the wire 72 with the second electrical contact 104 . The switch 80 is normally in an unactuated condition where the compression spring 92 is in its extended condition, and the plunger 96 is in a retracted position such that the first and second electrical contacts 98 , 104 are spaced from each other with no electrical communication therebetween, as shown in FIGS. 5 and 6 .
[0028] Actuation of the switch 80 results from movement of the ball 90 within the chamber 88 . When the switch 80 undergoes sufficient movement for the ball 90 to accelerate forward and overcome the bias of the compression spring 92 , the moving ball 90 compresses the compression spring 92 and eventually contacts the plunger 96 . The moving ball 90 applies a linear force to the plunger 96 , which responds by moving linearly through the bore 94 to an extended position whereby the first electrical contact 98 on the plunger 96 contacts the second electrical contact 104 on the arm 102 , as illustrated in FIG. 7 , for momentarily closing an electrical circuit, which is described in detail below. The compression spring 92 at this point is completely or near completely compressed, and the forward movement of the ball 90 ceases. Because the forward acceleration of the ball 90 terminates, the compression spring 92 expands and returns to its extended condition, thereby pushing the ball 90 to the rear end of the chamber 88 and spacing the ball 90 from the plunger 96 . Upon removal of the linear force applied by the ball 90 , the plunger 96 slides rearward within the bore 94 due to the bias of the leaf spring 100 and returns to its retracted position. The retraction of the plunger 96 spaces the first electrical contact 98 from the second electrical contact 104 , thereby opening the electrical circuit.
[0029] The electrical circuit can be any suitable electrical circuit that functions to turn the illumination source 54 on and off upon actuation of the switch 80 , and FIG. 8 illustrates a diagram of an exemplary embodiment of the electrical circuit. The switch 80 is a momentary switch implemented, by example, through a NAND gate 110 , such as a CD4011B gate, and a D-type flip-flop 112 , such as a CD4013B flip-flop. When the contacts 98 , 104 are closed upon actuation of the switch 80 , the output at pin 3 of the gate 110 is sent to the input CLK at pin 11 of the flip-flop 112 . At an initial state with the illumination source 54 off, the input D at pin 9 of the flip-flop 112 and the output Q-bar at pin 12 are HIGH. When the contacts are closed, the input CLK at pin 11 goes from HIGH to LOW. Data from the input D at pin 9 is shifted to output Q at pin 13 , which makes the output Q at pin 13 HIGH and turns the illumination source 54 on and makes Q-bar at pin 12 of the flip-flop 112 LOW. The next actuation of the switch 80 shifts the data from the input D at pin 9 , which is now LOW, to the output Q at the pin 13 to turn the illumination source 54 off. This cycle repeats with subsequent actuations of the switch 80 .
[0030] Referring now to FIG. 9 , which shows the external illumination apparatus 30 worn on the head of a surgeon, the switch 80 in the illustrated embodiment is positioned forward of the apex of the harness 44 to facilitate actuation of the switch 80 . The switch position preferably corresponds to forward of the head apex when the external illumination apparatus 30 is worn on the surgeon's head. In this position, the switch 80 is slightly angled with the ball 90 behind the compression spring 92 . Actuation of the switch 80 occurs when the surgeon quickly nods the head, as indicated by the arrow “A” in FIG. 9 . Forward and downward movement of the head during the nod (together with a relatively sudden stop and/or momentary reversal of the direction of movement of the head) induces forward movement of the ball 90 against the compression spring 92 . Because the ball 90 is angled, gravity aids forward movement of the ball 90 within the chamber 88 against the compression spring 92 . While the switch 80 has been described and illustrated as being located forward of the harness apex, the switch 80 can be positioned at any desired location on the head mount 32 .
[0031] As just described, movement of the head of the surgeon wearing the external illumination apparatus 30 actuates the switch 80 to turn the illumination source 54 on and off. The switch 80 defaults to the unactuated condition shown in FIGS. 5 and 6 and must be converted to the actuated condition shown in FIG. 7 via a quick head nod or other suitable motion to turn the illumination source 54 on or off In particular, to actuate the switch 80 , the surgeon performs a head nod, whereby the ball 90 moves forward to compress the compression spring 92 and push the plunger 96 through the bore 94 and against the bias of the leaf spring 100 to establish momentary contact between the first and second electrical contacts 98 , 104 . If the illumination source 54 is off prior to the actuation of the switch 80 , then the output Q at pin 13 of the flip-flop 112 in the electrical circuit becomes HIGH upon contact between the first and second electrical contacts 98 , 104 , as described above, to turn the light on. On the other hand, if the illumination source 54 is on prior to the actuation of the switch 80 , then the output Q at pin 13 of the flip-flop 112 in the electrical circuit becomes LOW upon contact between the first and second electrical contacts 98 , 104 , as described above, to turn the light off After the momentary contact between the first and second electrical contacts, 98 , 104 , the compression spring 92 pushes the ball 90 rearward, and the leaf spring 100 retracts the plunger 96 , as described above, to return the switch 80 to the unactuated condition. In short, the surgeon quickly nods to turn the illumination source 54 on and quickly nods again to turn the illumination source 54 off.
[0032] An exemplary method of operation of the above described embodiment of the system for providing illumination during phlebectomy procedures follows. The method comprises providing internal illumination with the subcutaneous illumination apparatus 10 and providing external illumination with the external illumination apparatus 30 .
[0033] Commonly, phlebectomy procedures involve the use of tumescent anesthesia, using, for example, large-volume, low-concentration lidocaine. Subcutaneous application of the tumescing solution elevates the veins closer to the skin surface and increases the field of illumination. Where the standard anesthesia protocol is inadequate to provide the desired conditions for illumination, additional saline solution can be injected.
[0034] The surgeon's preparation for the phlebectomy procedure includes placing the external illumination apparatus 30 upon the head by positioning the headband 34 around the head with the front portion 36 on the forehead and the rear portion 38 on the rear of the head such that the illumination assembly 50 and power source 52 are located on the forehead and the rear of the head, respectively, as shown in FIG. 9 . Adjustment of the headband 34 can be accomplished by adjusting the closure 40 . If needed, the surgeon can adjust the position of the illumination assembly 50 so that the light from the illumination source 54 projects in a desired direction.
[0035] During the following portion of the method involving the use of the subcutaneous illumination apparatus 10 , the illumination source 54 of the external illumination apparatus 30 is in the off condition. At the least, the illumination source 54 is in the off condition when the subcutaneous illumination apparatus 10 illuminates the interior of the body for vein identification. Further, lights in the procedure room, such as an operating room, are preferably off or dimmed for optimized performance of the subcutaneous illumination apparatus 10 .
[0036] Holding the handle 12 of the apparatus 10 , the surgeon inserts the illuminator portion 14 through a skin incision made in the vicinity of a vein to be avulsed. The surgeon can engage the electroluminescent device 16 using the switch 18 either before inserting the illuminator portion 14 or after insertion. The handle 12 is manipulated to place the apparatus 10 beneath a vein to be avulsed, with the electroluminescent device 16 facing upward (or radially outward, or otherwise toward the surgeon or observer). The light emitted by the electroluminescent device 16 passes upward through the vein (including the deoxygenated blood in the vein) and the surrounding tissue, thereby enabling the surgeon to better visualize the vein. For example, where the electroluminescent device 16 emits red, yellow or amber light, or light having a wavelength of 630-670 nm, or approximately 610 nm or less, the vein appears black in contrast to the surrounding tissue, which appears red or yellow. When viewed through the skin, the vein appears as a dark shadow, thereby facilitating location and the placement of further incisions, if required.
[0037] For the initial location of the vein, in one embodiment, the surgeon orients the longitudinal axis of the electroluminescent device 16 transverse to the presumed longitudinal axis of the vein. This configuration offers an improved chance that the vein falls within the field of illumination of the electroluminescent device 14 . Once the vein has been located, the surgeon can employ the blade 22 to locally avulse the vein prior to its removal through the skin incisions. Alternatively, a separate surgical implement such as a phlebectomy hook or forceps can be inserted into the incision(s) and employed to hook or grip, and avulse the vein along its length while it is being visualized through the skin.
[0038] When the surgeon removes the vein through the incision, some other material, such as fat and other surrounding tissues, is frequently removed along with or instead of the vein, and the surgeon performs a visual inspection of the removed material for identification of the vein and separation of the vein from the surrounding tissue. Because the procedure room is relatively dark, the surgeon can employ the external illumination apparatus 30 to provide illumination for the visual inspection. In particular, the surgeon, wearing the external illumination apparatus 30 on the head, quickly nods the head to actuate the switch 80 , as described above in detail, to convert the illumination source 54 from the off condition to the on condition. The light provided from the illumination source 54 enables the surgeon to better visualize the removed material for more accurate identification of the removed vein. If surrounding tissue has indeed been removed with the vein, the surgeon can separate the vein from the surrounding tissue. Upon completion of the visual inspection or whenever desired, the surgeon performs another quick head nod to actuate the switch 80 and, thereby, convert the illumination source 54 from the on condition to the off condition. The surgeon can turn the illumination source 54 on and off as needed throughout the phlebectomy procedure.
[0039] The above method can be adapted for use with other types of apparatuses that provide internal illumination. Examples of other operation methods for other types of internal illumination apparatuses are given in the aforementioned and incorporated '371 publication and corresponding application. Further, the above method can be adapted for use with other types of switches that are activated in hands-free (or hands-free and feet-free) manners other than nodding the head.
[0040] While the external illumination apparatus 30 has been described as part of the illumination system for phlebectomy procedures, the apparatus 30 can be employed alone or in other systems for other types of procedures. Further, the external illumination apparatus 30 can be employed with other types of internal illumination devices for phlebectomy or other types of procedures.
[0041] While certain invention(s) have been specifically described herein in connection with certain specific embodiments thereof, it is to be understood that this description is an illustration of useful embodiments of the invention(s) and not a limitation of the scope of the invention(s). | A method comprising (a) illuminating a blood vessel in a relatively low-light surgical field by inserting a subcutaneous light source into tissue near the blood vessel and to a first location in the tissue underlying the blood vessel, and causing emission of light from the subcutaneous light source while the subcutaneous light source is at the first location, so that light from the subcutaneous light source passes through the tissue near the blood vessel, toward an observer; (b) drawing a portion of the tissue near the blood vessel through an incision in the skin; and (c) illuminating the drawn portion of tissue by activating an external light source in a hands-free manner, thereby facilitating determining whether the drawn tissue is the blood vessel. | 5 |
[0001] This application is a continuation in part of and claims priority of application Ser. No. 12/694,467, filed Jan. 27, 2010, which is a continuation in part and claims priority of application Ser. No. 12/217,425, filed Jul. 3, 2008, which is a continuation in part and claims priority of application Ser. No. 12/077,113, filed Mar. 17, 2008, which is a continuation in part and claims priority of application Ser. No. 12/070,687, filed Feb. 20, 2008, which is a continuation in part and claims priority of application Ser. No. 11/705,979, filed Feb. 13, 2007.
FIELD OF THE INVENTION
[0002] The present invention relates to windows, and more particularly to windows that are impact resistant.
BACKGROUND OF THE INVENTION
[0003] Windows and glass panes in doors, panels and the like are a major source of unwanted heat loss and gain in a structure. With increased cost of fuel and energy, the moderation of unwanted energy losses on account of these structures has become of increasing importance.
[0004] One method of reducing heat transfer through windows has been through the use of double glazed, and even triple glazed windows. Double glazed windows make use of two panes of glass that are attached together by a spacer. In some instances, the space between the two panes is hermetically sealed and can be filled with dry air, or with a dry inert gas such as argon or nitrogen.
[0005] Although double glazing successfully reduces the energy transfer through a window, the use of two panes of glass substantially increases the weight of the window. Increased weight in windows is normally unwanted because of the need for heavier frames and sashes, heavier mounting hardware, and more rigid sash materials. Moreover, construction of double glazed windows is more complex than normal window construction, because the double glazed pane unit is constructed separately from the sash unit and then the sealed double glazed pane unit is mounted into the sash to assemble the insulated window.
[0006] An alternative to the normal method of assembling a double glazed window makes use of a sash unit that has the spacer for the glazing panes formed integrally with the sash. This innovation avoids the separate construction of the sealed double glazed pane unit, because the panes are mounted into a sash that has been formed from sash elements that include the integral spacer.
[0007] During the past several years, it has also become important to provide windows that are impact resistant. Many building codes, especially in areas that are at risk for hurricanes and major storms, now require impact resistant windows. In addition, blast resistance and shatter resistance has come to be important for windows in selected locations. A conventional method for the provision of impact and shatter resistance for windows has been the construction of safety glass. In this method of construction, a layer of durable transparent material, which may be a polymer, such as a polyurethane or polyvinyl butyral (PVB), is inserted between and adhered to two panes of glass to make a layered structure having glass on the outside and the polymer on the inside. Uvekol® may be used as the durable transparent material. When the window absorbs a blow that is powerful enough to break the glass, the presence of the durable polymer inhibits pieces of glass from flying in the direction of travel of the blow.
[0008] However, in many cases, the pane of glass separates from the sash. As the pane of glass is shattered by a missile, it tends to separate from the sash. The now shattered pane of glass separates from the sashes and enters the structure in the direction of travel of the missile, creating a hazard. There is a need to reduce the tendency of the pane of glass to separate from the sash, and also to reduce the tendency of the pieces of shattered glass from separating.
SUMMARY OF THE INVENTION
[0009] The present invention is directed to a novel multiple glazed impact resistant window and a method of making the multiple glazed impact and blast resistant window. The method includes forming a window sash that delineates a mounting space for mounting a first pane and a second pane opposite and parallel to and spaced apart from each other. A durable transparent or translucent polymer film is attached to a surface of a glazing pane that is mounted in the window sash. The film inhibits pieces or shards of glass and missiles from entering the structure if the glass is broken by an impact or a blast. Double sided tape adheres the film to the window sash so that the film is inhibited from pulling away from the window sash during impact. The resulting window will pass applicable missile tests. The resulting window also provides additional security protection for the building in which it is installed, and for the building's inhabitants.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 shows a perspective view (C) of an embodiment of an impact resistant multipane window, such as a double glazed or triple glazed window, according to the present invention; and
[0011] FIG. 2 shows a cross-section of an embodiment of a double glazed glass pane window with a protective layer of durable transparent or translucent polymer film on in accordance with the present invention, wherein the interior pane is fixed to the sash 16 with double sided tape that contacts a durable polymer film attached to the pane.
[0012] FIG. 3 shows a cross-section of an embodiment of a triple glazed glass pane with a protective layer of durable transparent or translucent polymer film on in accordance with the present invention, wherein the interior pane is fixed to the sash 116 with double sided tape that contacts a durable polymer film attached to the pane.
[0013] FIG. 4 illustrates a partial cross-section view of an embodiment of an impact resistant multipane insulating window of the present invention.
[0014] FIG. 5 illustrates a partial cross-section view of another embodiment of an impact resistant multipane insulating window of the present invention.
[0015] FIG. 6 shows a partial cross-section of an embodiment of an impact resistant multipane window of the present invention wherein the sash is a polymer extrusion having a stiffener and wherein the panes are sealed to the sealing surfaces of the integral spacer with glazing tape; optional snap-in glazing beads are omitted in this figure
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] In one embodiment of the present invention, a double glazed impact resistant window is produced by forming a window sash that delineates a mounting space for mounting a first pane and a second pane opposite and parallel to and spaced apart from each other. FIG. 2 . The double glazed window has four window pane surfaces designated as 1, 2, 3 and 4, as shown in FIG. 2 . One pane of the window is provided with a durable translucent or transparent polymer film on what is designated as surface four (4) of the glazing. The film can be formed by coating or adhering the durable transparent polymer film to surface four (4) of the pane. The film can be applied to the pane either before or after it is conformed to the size required for the mounting space. The first pane is mounted in the mounting space, and the second pane is mounted in the mounting space to form a double glazed impact resistant window. Double sided tape adheres the pane comprising surface 4 to the sash.
[0017] In use, if a missile or similar object impacts the window, the glazing of the first pane 11 and the second pane 12 may be broken. The polymer film 10 , by being present on surface 4, acts as a “net” or barrier between the glazing and the interior of the building to inhibit debris from entering the building. The polymer film retains the shards and pieces of broken glazing material caused by missile impact. However, empirical observation teaches that the polymer film will pull away from the sash due to the energy applied to the polymer film from impact of the missile or similar object. Unexpectedly, the use of double sided tape 14 , with one side of the tape adhered to surface 4 and the opposite side of the tape adhered directly adjacent the sash as show in FIG. 2 , materially retards the polymer film from pulling away from the sash, so that the polymer film retains the broken glazing and prevents broken glazing from entering the structure. The resulting window will pass current impact resistance testing for windows according to applicable building codes for ASTM E1886-02, ASTM E1996-03, and Wind Zone 3, small missile and large missile.
[0018] The double sided tape 14 is adhered to the durable transparent film, which is adhered to the portions of surface 4 of the second pane that are in close proximity of the sash. FIG. 2 . As shown in the drawing figure, the double sided tape is positioned within and relative to the sash so that it is not visible to the casual observer of the window.
[0019] FIG. 3 shows a triple glazed window. The triple glazed window has six window pane surfaces, designated in FIG. 3 as 1, 2, 3, 4, 5 and 6. If a missile or similar object impacts the window, the glazing of the first pane 111 the second pane 113 and the third pane 112 may be broken. The polymer film 110 , by being present on surface 6, acts as a “net” or barrier between the glazing and the interior of the building to inhibit debris from entering the building. The polymer film retains the shards and pieces of broken glazing material caused by missile impact. However, empirical observation teaches that the polymer film will pull away from the sash due to the energy applied to the polymer film from impact of the missile or similar object. Unexpectedly, the use of double sided tape 114 , with one side of the tape adhered to surface 6 and the opposite side of the tape adhered directly adjacent the sash as shown in FIG. 3 , materially retards the polymer film from pulling away from the sash, so that the polymer film retains the broken glazing and prevents broken glazing from entering the structure.
[0020] Double sided tape 114 is adhered to the durable transparent film, which is adhered to the portions of surface 6 of the interior pane that are in close proximity of the sash. FIG. 3 . As shown in the drawing figure, the double sided tape is positioned within and relative to the sash so that it is not visible to the casual observer of the window.
[0021] As used herein, the terms “directly adjacent the sash” means the side of the pane is abutting an inner edge of the sash, wherein the outer edge of the sash directly opposite the inner edge will form either the front or back side of the window sash.
[0022] In an embodiment of the invention, the sash can be formed from extruded PVC members. The parts of the sash, commonly the top and bottom rails and the left and right stiles, can then be cut and assembled from the PVC extrusion to form one or more mounting spaces for panes. The sash may optionally include a spacer 18 , providing mounting surfaces for the panes. Surface 4 can be coated with the durable transparent polymer film anytime prior to assembly, and assembly can be completed by attaching double-sided glazing tape to the mounting surfaces and sealing the panes to the glazing tape. Snap-in glazing beads can be installed if desirable.
[0023] When a polymer extrusion is used for the sash construction, the resulting window requires very little maintenance and is very resistant to environmental damage.
[0024] As used herein, the term “window” means a sash with one or more transparent or translucent glazing panes that can be used to cover any opening in a structure. Commonly, a window is installed in a window frame. The term window includes all windows, such as single hung windows, double-hung windows, bay windows, bow windows, casement windows, fixed windows, and the like; door panels having transparent or translucent glazing; wall panels having transparent or translucent glazing; and similar structures.
[0025] As used herein, the term “sash” means the framework that holds the glazing in a window.
[0026] As used herein, the terms “mounting space” mean the space in a sash into which a glazing pane is to be mounted. Commonly the mounting space is delineated by the parts, or elements, of the sash, which are cut to the proper size that when attached together form a mounting space of approximately the same shape and slightly larger size than the glazing pane that is to be mounted therein. The mounting space can be of any shape and size, including round, oval, oblong, rectangular, square, triangular, pie-shaped, or of any other shape. Commonly, the mounting space is square, rectangular, or round.
[0027] As used herein, the terms “sealing surface” mean a surface, such as a surface of a spacer or a surface of a sash against which the glazing pane is mounted. The sealing surface is commonly a flat surface that is parallel to the plane of the glazing pane.
[0028] As used herein for double glazed windows, the first pane 11 is the pane closest to the exterior of the building in which the window is mounted, and the second pane 12 is the pane closest to the interior of the building in which the window is mounted. Surfaces 1, 2, 3 and 4 of the first and second panes, respectively, are as shown in FIG. 2 . Surface 1 is on the first pane and is adjacent to the exterior of the building in which the window is mounted, and surface 2 is present on the first pane on an interior of the window adjacent to the spacing between panes. Surface 3 is present on the second pane and is adjacent to the spacing between panes. Surface 4 is present on the second pane and is adjacent to the interior of the building in which the window is located.
[0029] As used herein for triple glazed windows, the first pane 111 is the pane closest to the exterior of the building in which the window is mounted, and the third pane 112 is the pane closest to the interior of the building in which the window is mounted. Surfaces 1, 2, 3, 4, 5 and 6 of the first, second and third panes, respectively, are as shown in FIG. 3 . Surface 1 is on the first pane and is adjacent to the exterior of the building in which the window is mounted, and surface 2 is present on the first pane on an interior of the window adjacent to the spacing between panes. Surfaces 3 and 4 are present on the second pane and adjacent to the spacing between panes. Surfaces 5 and 6 are present on the third pane, and Surface 6 is adjacent to the interior of the building in which the window is located.
[0030] In some embodiments, the present sash may be free of an integral spacer.
[0031] As shown in FIG. 2 , the first pane and the second pane of the double glazed window are spaced apart by a distance that is determined by the width of the sash or, where present, the spacer 18 . The glazing panes may comprise a first glazing pane 11 and a second glazing pane 12 , the second glazing pane having a durable transparent polymer film 10 attached to surface 4. Double sided tape 14 is used to further seal the second glazing pane to the sash, with the double sided tape adhered to the polymer film and to the sash. The first pane and the second pane may be attached to the sealing surfaces of the spacer by use of one or more sealants.
[0032] The window may comprise a setting 20 block, a sash frame 22 , a glazing stop 24 , and panes formed of glass 26 .
[0033] As shown in FIG. 3 , the first pane, second pane and the third pane of the triple glazed window are spaced apart by a distance that is determined by the width of the sash or, where present, the spacer 118 . The glazing panes comprise a first glazing pane 111 and a second glazing pane 113 , and a third glazing pane 112 , the third glazing pane having a durable transparent polymer film 110 attached to surface 6. Double sided tape 114 is used to further seal the second glazing pane to the sash. The first pane and the second pane may be attached to the sealing surfaces of the spacer by use of one or more sealants.
[0034] The window may comprise a setting 120 block, a sash frame 122 , a glazing stop 124 , and panes formed of glass 126 .
[0035] In some embodiments, the enclosed space formed between glazing panes can be hermetically sealed from the surrounding atmosphere, and if desired, filled with a gas, such as dry air, or with an inert gas such as argon or nitrogen. In some embodiments, it is useful to provide a desiccant, such as sodium silicate, for example, (not shown in the figures) that is in communication with the enclosed space and is useful to absorb any moisture that may enter the enclosed space in order to avoid or reduce condensation. A desiccant is particular useful where film 210 , 220 is applied to surface 2 and/or surface 3 ( FIG. 4 , FIG. 5 , FIG. 6 ) within the enclosed space, since the film tends to outgas, and a desiccant can reduce the harmful effects of outgassing.
[0036] The glazing panes that are useful in the present invention can each separately comprise a material selected from the group consisting of glass, fiberglass and plastic. If plastic is used, it can be a polycarbonate, a polyurethane, LEXAN, Plexiglas, or the like. In some embodiments, it is preferred that the first pane and the second pane each comprise glass. The glass can be annealed glass, tempered glass, heat strengthened or untempered glass. Due to reduced cost, in some embodiments untempered glass is preferred for the glazing panes. The benefits of the present invention of improving impact, blast and shatter resistance are available for both double glazed and triple glazed windows.
[0037] The durable transparent polymer film that is useful in the present invention can comprise any polymer, including polyamides, such as nylon; polyolefins such as polypropylene and polyethylene; polyester such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate; polyacetal; polycarbonate; copolyesters such as polyethylene terephthalate isophthalate; and the like.
[0038] It is preferred that the durable transparent polymer film is at least translucent to visible light and may be transparent. In particular, it is preferred that the polymer film have a percent transmission of visible light of at least about 30%, at least about 40% is more preferred, at least about 50% is yet more preferred, at least about 60% is even more preferred, at least about 70% is yet more preferred, at least about 80% is even more preferred, and a visible light transmission of at least about 82% is yet more preferred.
[0039] The polymer film should also be durable. When it is said that the polymer film is durable, it is meant that the polymer is one that has a tensile strength of at least about 15,000 psi, at least about 20,000 psi is more preferred, at least about 25,000 psi is even more preferred, and at least about 30,000 psi is yet more preferred.
[0040] It is also preferred that the polymer film is one that has a break strength of at least about 50 lbs/in, and at least about 100 lbs/in is even more preferred, at least about 150 lbs/in is yet more preferred, and at least about 200 lbs/in is even more preferred.
[0041] The polymer film can be single thickness, or it can be laminated. Laminated films of this type are described, for example, in U.S. Pat. No. 6,951,595. Films suitable for the present invention are available commercially from Madico, Inc., Woburn, Mass.; 3M, Minneapolis, Minn., and Mitsubishi Polyester Film, LLC, among others.
[0042] The durable transparent polymer film of the present invention normally has a uniform thickness, which can be any thickness that is sufficient to provide the features required. Films that are useful in the present invention normally have a thickness within a range of about 0.25 mil to about 50 mil. A thickness from about 5 mil to about 30 mil is preferred, and a thickness of from about 8 mil to about 22 mil is more preferred. Generally, the larger the missile against which protection is desired, the thicker the material to be used.
[0043] It may useful for the durable transparent polymer film to be supplied with, or to be prepared to have, a pressure sensitive adhesive on one side that is suitable for adhering the film to the pane. In particular, it is useful for the film to have a pressure sensitive adhesive suitable for forming a tight bond with a clean glass surface. The present polymer film can be provided with a hard coat, such as is described in U.S. Pat. No. 7,101,616, for example, or without such a hard coat.
[0044] A preferred durable transparent polymer film is a three layer scratch resistant film having an acrylic adhesive coated on one side thereof for adhering the film to window glazing. The elongation/stretch characteristics of the film may be about 150% machine direction and 100% transverse direction. Tensile strength may be about 36,000 pounds per square inch of each layer. The layers may be formed of polyethylene terephthalate.
[0045] The first pane 11 , 111 and the second pane 12 , 113 , and if used, the third pane, 112 , are spaced apart by a certain distance. The distance between the panes is determined by the distance between the sealing surfaces of the spacer 18 , 118 , plus the thickness of the sealant that is used to adhere the panes to the integral spacer. Although the panes can be spaced apart by any distance that will provide the advantages of the invention, it is preferred that the first pane and the second pane are spaced apart by a distance of from about 6 mm to about 20 mm, a distance of from about 9 mm to about 16 mm is more preferred.
[0046] The sash may be formed of any material that is conventionally used for the construction of window sashes. In embodiments of the present invention, the sash comprises a material that is selected from one or more of the group consisting of wood, metal and plastic.
[0047] It has been found to be particularly useful for the sash to be formed from polymer extrusions. FIG. 6 . Examples of extruded sash material are shown in U.S. Pat. Nos. 5,622,017 and 6,286,288, among others. Various types of extruded window and door sash material are available from Chelsea Building Products, Oakmont, Pa., and other manufacturers.
[0048] Extruded sashes may be produced from any polymer, copolymer, or polymer blend that is suitable to provide the advantages of the invention. The polymer can be filled or unfilled. Examples of materials that are suitable for the production of polymer sash extrusions include polyvinyl chloride, polycarbonate, polyvinyl, and Extrudable Thermal Plastics available from Geon division of the B. F. Goodrich Co., as well as the materials described in U.S. Pat. Nos. 4,430,478 and 5,783,620, among others.
[0049] When the sash material is a polymer extrusion, it is optional to include a metal, fiberglass or plastic stiffener, such as stiffener 601 . Such stiffeners are sometimes used when a long sash length is required, or when exceptionally heavy glass must be supported. One or more metal stiffeners can be used in a window sash.
[0050] The first pane and the second pane and if used, the third pane, may be sealed to the sealing surfaces of the spacer, by the use of an additional sealant, since surface 6 will be secured to the sash by double sided tape in this embodiment. The sealant can be any material or device that is used to seal glazing panes to a window sash, and can be selected from glazing tape, silicone sealant, butyl sealant, or a combination of any two or more of these techniques.
[0051] The double sided tape may be a polymer tape having pressure sensitive adhesive on both sides. Some tapes are formed from closed cell polyolefin foam with a glass adhesive on one side and a sash/frame adhesive on the other. See, e.g., Glazing Tape VG 100, or VG-300, available from Venture Tape, Rockland, Mass. Tape suitable for use in some embodiments of the present application is also available from Lamatek, Inc., West Deptford, N.J., and Press-On Tape and Gasket Corp., Addison, Ill. The preferred double sided tape is 3M brand VHB 4991, which is a general industrial tape formed of closed cell acrylic foam, having a thickness of about 2.3 mm, or an equivalent double sided tape, or a double sided acrylic foam tape from HI-BOND TAPES, INC., which may be VST 6200G. The acrylic foam tape should have a thickness of not less than 1.8 mm, and the thickness will usually be up to 3.0 mm. It is preferred to apply a primer prior to the mating surfaces when applying the double sided tape to optimize the holding power and achieve the goal of the invention of holding the broken or shattered glass within the film.
[0052] While the use of double sided tape as described has been proven to meet the standards of missile tests as described, adhesives without a substrate and having similar properties may be used. The adhesive must be able to bond to the durable polymer film and the sash and hold the film during missile tests identified above, as well as cyclic static air pressure loading testing protocols, with at least the same degree of strength as the double sided tape. Materials such as SikaFlex or butyl adhesives may be useful.
[0053] It is preferred to use double sided tapes having closed cell acrylic foam, such as 3M brand VHB 4991. One side of the tape adheres to the sash ( FIG. 2 ; FIG. 3 ) or the spacer bar ( FIG. 4 ; FIG. 5 ), and the other side adheres to the film. The foam allows limited movement of the film coated or covered glazing relative to the window sash, and absorbs energy, during missile impact.
[0054] When the present window is assembled, the panes 11 , 12 and the sash 16 provide an enclosed space that serves as an insulating feature of the window. In some embodiments, the enclosed space is hermetically sealed from the outside environment, and if desired, the gas in the enclosed space can be dry air, or can be an inert gas, such as argon or nitrogen.
[0055] In order to minimize the moisture content of the gas in the enclosed space, a desiccant is optionally provided that is in contact with the enclosed space. The desiccant can be placed into an aperture of an extruded sash, if desired, so that it communicates with the gas in the enclosed space.
[0056] The present invention encompasses a method of making a double glazed or triple glazed impact resistant window. The method comprises forming a window sash that delineates a mounting space for mounting a first pane and a second pane opposite and parallel to and spaced apart from each other. Optionally, a third pane may be mounted in a similar manner. The mounting space is typically formed by constructing a frame of sash members, often pieces cut to length from a long extrusion or molding, as described above, where the frame encloses a space that is slightly larger than and approximately the same shape as the pane that is to be mounted therein. The mounting space is bounded on each side by the sash 16 and on the surface to which the pane is to be mounted. The mounting space may be sized so that the pane will fit therein without touching any side of the mounting space, but will rest on all parts of the respective sealing surface.
[0057] At an appropriate time during the fabrication process, the durable transparent polymer film 10 is adhered to a surface of a glazing pane, such as surface 4 of the second pane 12 , or the transparent polymer film 110 may be adhered to surface 6 of the triple glazed window, for example. The film can be adhered to a large piece of glass, and then the panes, with film attached, can be cut from the larger sheet to conform to the size and shape of the mounting space, or alternatively, the film can be adhered to the pane after the larger sheet has been cut to conform to a suitable size. The film may be attached to other surfaces, such as surfaces 2 and/or 3 of the double glazed window, and surfaces 2, 3, 4, and/or 5 of the single glazed window.
[0058] The polymer film is commonly adhered to the pane by the use of a pressure sensitive adhesive that coats one side of the film and adheres tightly to the pane. When the film is obtained from a supplier, it optionally already has the adhesive applied to one side of the film, and provides a protective film, often silicone, over the adhesive. The protective film can be removed and the film can be adhered to the pane.
[0059] When the panes are glass, it is preferred that the glass is very clean before the durable transparent polymer film is attached. Any small particle that is present on the glass when the film is applied will remain in the assembly forever, and can have a negative effect on the strength of adherence of the film to the glass (which may negatively affect the impact resistance of the window) and on the visual quality of the window. Accordingly, it is preferred that the glass is thoroughly cleaned prior to applying the film and that the assembly of the film to the glass be carried out in a clean atmosphere.
[0060] In some embodiments, excess durable transparent polymer film may be present around the edges of the pane after the durable transparent polymer film has been adhered. In these embodiments, the method further includes trimming the excess durable transparent polymer film prior to the mounting step. The trimming can be done by any method known in the art. For example, in some embodiments, the trimming may be done with a blade, such as a knife or box cutter. In other embodiments, the trimming may be done with a laser or water jet.
[0061] In further embodiments where the method includes trimming, the trimming of the excess durable transparent polymer film may be done such that the durable transparent polymer film edge is flush with the edge of either glass pane. In other embodiments where trimming is utilized, an amount of durable transparent polymer film may remain over the edge of the glass pane. In further embodiments where trimming is utilized, the trimming of the durable transparent polymer film may be done such that the film no longer covers the entire glass pane. It is preferred that the durable transparent polymer film cover the entire glass pane of surface 4, so that the durable transparent polymer film is properly bonded to the frame or sash, such as shown in FIG. 2 , by the double sided tape.
[0062] If trimming of the durable transparent polymer film is utilized, it may be done at any stage of the presently claimed method. In some embodiments, the trimming may be done before the protective layer is provided. In other embodiments, the trimming may be done after the protective layer is provided. In other embodiments, the trimming may be done before mounting the pane in the mounting space. In further embodiments, the trimming may be done after mounting the pane in the mounting space.
[0063] In one embodiment, when film-coated panes of the proper size are prepared, the second pane is mounted in the mounting space with the film covered surface 4 of the pane 12 directly adjacent the sash 16 , which may be adjacent to the interior of the building. FIG. 2 . The film 114 is similarly applied as shown in FIG. 3 .
[0064] The use of glazing tape as the sealant prevents or minimizes the amount of “squeeze up” of liquid or semi-liquid sealants into the viewing area of the mounting space. Because the enclosed space is essentially sealed as soon as both panes are mounted in the sash, any liquid or semi-liquid sealant that is squeezed up between the pane and the sealing surface into the viewing area of the mounting space cannot be removed. However, the use of glazing tape having a foam core substantially prevents such squeeze up, but provides a strong and durable bond between the pane and the sash. When glazing tape is used as the sealant, the step of mounting the pane in the sash involves adhering glazing tape to the sealing surface of the mounting space and contacting each pane with the tape so that the film-covered surface of the pane is facing the tape. In some embodiments, it is useful to supplement glazing tape with a deformable type sealant, such as a silicone sealant, in order to improve the integrity of the seal.
[0065] A typical embodiment of a window of the present invention is shown in FIG. 1 , where (C) shows a perspective view of a window having sashes 16 that have been assembled to form a frame that defines a mounting space, into which panes 11 , 12 are mounted to form an impact resistant multipane window.
[0066] A particular advantage of applying the film to surface 4 is that the film does not reduce the enclosed space between panes of glazing that acts as an insulator, including double or triple pane windows where the enclosed space is filled with a noble gas such as argon. Note that in the embodiments of FIG. 4 , FIG. 5 , and FIG. 6 the area of the enclosed space is reduced by the film or films on surface 2 and 3. Further energy improvement may be achieved by treatment of a layer of the laminated film with a thin layer of metal or metallic oxide, such as titanium dioxide, bronze, silver, or stainless steel. By treating the film, rather than the glazing itself, the film lends lend low-emissivity properties to the window without the requirement of maintaining an inventory of low-emissivity glass.
[0067] FIG. 4 , FIG. 5 , and FIG. 6 show partial cross-sectional views of embodiments of a double glazed impact resistant window of the present invention in which the sash 301 has an integral spacer 310 projecting therefrom. The integral spacer 310 provides a first sealing surface 311 and a second sealing surface 312 , for mounting glazing panes opposite to and parallel to each other and spaced apart by a distance that is determined by the width of the integral spacer. The glazing panes comprise a first glazing pane 101 and a second glazing pane 102 , each having a durable transparent polymer film 111 and 112 attached to the surface of the pane that faces the other pane. Each embodiment shown in FIG. 4 and FIG. 5 show glazing beads 501 , 502 that optionally can be used to further seal the glazing panes onto the sash. In FIG. 6 , the optional glazing beads are omitted. The optional glazing beads 501 and 502 can be pre-formed plastic snap-in type glazing beads, particularly when the sash 301 is an extruded member as shown in FIG. 6 , or they can be formed from a silicone, butyl, or other sealant material, or both a snap-in glazing bead and a polymeric-type sealant can be used if desirable to form a hermetic seal for the enclosed space 201 and/or to more securely seal the pane into the sash. The first pane 101 and the second pane 102 are attached to the sealing surfaces 311 and 312 of the integral spacer 310 by a first sealant 401 and a second sealant 402 , or, as shown in FIG. 5 , by a sealant 403 that is unitary: enclosing the spacer and forming sealing surfaces for both panes.
[0068] FIG. 4 , FIG. 5 , and FIG. 6 show an enclosed space 201 that is bounded by the spacer that is integral with the sash, the first pane, and the second pane. In some embodiments, the enclosed space can be hermetically sealed from the surrounding atmosphere, and if desired, it can be filled with a gas, such as dry air, or with an inert gas such as argon or nitrogen.
[0069] FIG. 4 , FIG. 5 , and FIG. 6 each show the first pane 101 and the second pane 102 each having a durable transparent polymer film 111 and 112 , respectively attached to the surface of the pane that faces the other pane.
[0070] By locating the durable polymer film on the protected interior surfaces of the panes, in other words, on the surface of each pane that faces the other pane and that seals against the integral spacer of the sash, the free surface of each film is protected from any touch and retains its clear, unmarred visual qualities without the expense of applying a hard coat.
[0071] The first pane 101 and the second pane 102 are spaced apart by a certain distance. FIG. 4 , FIG. 5 , and FIG. 6 . show the distance as L. The distance between the panes is determined by the distance between the sealing surfaces 311 and 312 of the integral spacer 310 , plus the thickness of the sealant 401 and 402 that is used to adhere the panes to the integral spacer. Although the panes can be spaced apart by any distance that will provide the advantages of the invention, it is preferred that the first pane and the second pane are spaced apart by a distance of from about 1 mm to about 20 mm, a distance of from about 6 mm to about 16 mm is more preferred, and a distance of from about 6 mm to about 12 mm is even more preferred.
[0072] When the sash material is a polymer extrusion, it is optional to include a metal stiffener 601 as shown in FIG. 6 . Such stiffeners are sometimes used when a long sash length is required, or when exceptionally heavy glass must be supported. One or more metal stiffeners can be used in a window sash.
[0073] FIG. 6 illustrates the use of an extruded sash 301 in the present invention, and shows the inclusion of an optional metal stiffener 601 . The extruded sash 301 includes an integral spacer 310 having two sealing surfaces against which the first pane 101 and the second pane 102 are sealed. The distance between the sealing surface for the first pane and the sealing surface for the second pane determines the distance by which the first pane and the second pane are spaced apart. The panes each have a durable transparent polymer film 111 and 112 adhered to the surface of the pane that faces the other pane. Snap-in glazing beads are optionally useful for this embodiment and could be attached into snap-in glazing bead slots 511 and 512 , such glazing beads are not shown in FIG. 6 .
[0074] FIG. 4 , FIG. 5 , and FIG. 6 indicate that the first pane 101 and the second pane 102 are sealed to the sealing surfaces 311 and 312 of the spacer 310 by the use of a sealant 401 and 402 , or 403 . The sealant can be any material or device that is used to seal glazing panes to a window sash, and can be selected from glazing tape, silicone sealant, butyl sealant, or a combination of any two or more of these techniques. As described herein, it is preferred to use glazing tape having closed cell acrylic foam as the sealant on any surface of the window glazing that is covered with film, with one side of the tape adhered to the spacer bar or sash and the opposite side adhered to the polymer film.
[0075] If desired, optional glazing beads 501 and 502 can be used to finish the glazing. When the sash comprises a polymer extrusion, the glazing bead can be snap-in glazing bead.
[0076] When a window is assembled, the glazing panes 102 and 103 and the spacer 310 provide an enclosed space 201 that serves as an insulating feature of the window. In some embodiments, the enclosed space 201 is hermetically sealed from the outside environment, and if desired, the gas in the enclosed space can be dry air, or can be an inert gas, such as argon or nitrogen.
[0077] The mounting space is bounded on each side by the sash 301 and on the surface to which the pane is to be mounted by the sealing surface 311 or 312 of the integral spacer 310 . The mounting space is sized so that the pane 101 or 102 will fit therein without touching any side of the mounting space, but will rest on all parts of the respective sealing surface 311 or 312 . The spacing of the pane 101 or 102 from the sash 301 is shown in FIGS. 4 , 5 , and 6 and is useful to permit differential expansion of the sash and the pane without causing contact between the pane and the sash, other than at the sealing surface 311 or 312 .
[0078] When film-coated panes of the proper size are prepared, the first pane 101 may be mounted in the mounting space with the film-covered surface of the pane facing the sealing surface 311 of the integral spacer 310 . This is then repeated for the second pane 102 .
[0079] Glazing beads 501 and 502 can optionally be added to the window to finish the assembly if desired.
[0080] In an embodiment of the invention, layers of the durable transparent polymer film is adhered to, or coated onto a pane in directions that are not parallel to one another. Without being bound by theory, the inventors believe that the impact resistance is achieved by adhering and/or coating at least two layers of the durable transparent polymer film onto in directions that are not parallel to one another. Such adherence or coating may result in at least some cross-linking between the layers, which may provide enhanced impact resistance over films that are adhered or coated in only one layer and/or are adhered or coated in more than one layer, but in which adjacent layers are parallel to one another. For example, a first layer may be adhered or coated in the machine direction (MD) and a second layer may be adhered or coated to the first layer in the transverse direction (TD). Alternatively, the first layer may be adhered or coated in the TD and the second layer may be adhered or coated in the MD. The layers of the durable polymer transparent film may be adhered or coated at any opposing angles to one another, as long as the at least two layers are not adhered or coated in directions parallel to one another.
[0081] Similarly, more than two layers may be adhered or coated to a pane and to one another, as long as at least two of the layers are adhered or coated in directions that are not parallel to one another. For example, a first layer may be adhered or coated in the MD, a second layer may be adhered or coated in the TD, and a third layer may also be adhered or coated in the TD. In another embodiment, the first layer may be adhered or coated in the MD, the second layer may be adhered or coated in the MD, and a third layer may be adhered or coated in the TD.
[0082] As used herein, the terms “in directions that are not parallel to one another” means the layers are adhered or coated at angles to one another of between about 5 degrees and about 175 degrees. By way of example, in some embodiments, the directions may be offset at angles between about 45 degrees, and about 135 degrees, in other embodiments, between about 75 degrees and about 105 degrees, and in some embodiments, the directions are at angles of about 90 degrees.
[0083] The impact resistant multipane windows of the present invention can be mounted and used in any application in which conventional impact resistant and/or multipane windows are used. Commonly, the novel windows can be mounted in frames in structures such as residential or commercial buildings to serve as strong, energy conserving windows. The novel windows can be components of doors, panels, skylights, and any other similar application. Mounting and use of the present windows is similar to the methods that are well known and are used for conventional impact resistant and/or multipane windows.
[0084] The present invention encompasses a further method of making a double glazed impact resistant window. The method comprises, in some embodiments, forming a window sash that delineates a mounting space for mounting a first pane and a second pane opposite and parallel to and spaced apart from each other, the sash having an integral spacer that forms a sealing surface of the mounting space for each pane; adhering a durable transparent polymer film to a surface of the first pane; attaching a protective layer to at least a portion of the durable transparent polymer film to protect the durable transparent polymer film from damage prior to assembling the double glazed impact resistant window; conforming the pane to the size and shape of the mounting space; removing the protective layer; mounting the first pane in the mounting space with the film covered surface of the pane facing the sealing surface of the integral spacer; and repeating the previous steps for the second pane.
[0085] The impact resistant multipane windows of the present invention can be mounted and used in any application in which conventional impact resistant and/or multipane windows are used. Commonly, the novel windows can be mounted in frames in structures such as residential or commercial buildings to serve as strong, energy conserving windows. The novel windows can be components of doors, panels, skylights, and any other similar application. Mounting and use of the present windows is similar to the methods that are well known and are used for conventional impact resistant and/or multipane windows.
[0086] Other embodiments within the scope of the claims herein will be apparent to one skilled in the art from consideration of the specification or practice of the invention as disclosed herein. It is intended that the specification be considered to be exemplary only, with the scope and spirit of the invention being indicated by the claims.
[0087] All references cited in this specification, including without limitation all papers, publications, patents, patent applications, presentations, texts, reports, manuscripts, brochures, books, Internet postings, journal articles, periodicals, and the like, are hereby incorporated by reference into this specification in their entireties. The discussion of the references herein is intended merely to summarize the assertions made by their authors and no admission is made that any reference constitutes prior art. Applicants reserve the right to challenge the accuracy and pertinency of the cited references.
[0088] In view of the above, it will be seen that the several advantages of the invention are achieved and other advantageous results obtained.
[0089] As various changes could be made in the above methods and compositions by those of ordinary skill in the art without departing from the 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. In addition it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. | A novel impact and blast resistant window is presented. A surface of a glazing pane has a durable transparent polymer film coated or adhered thereto. The surface of the window pane having the film is sealed to the sash by double sided tape. The resulting window produces an unexpected ability for the durable transparent polymer film to retain pieces of broken glass driven toward the interior of the building by a missile striking an exterior of the window, without the durable transparent polymer film pulling loose from the window sash. | 4 |
This application is a continuation of application Ser. No. 105,916, filed Dec. 21, 1979, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to separatory apparatus for separating liquids by selective permeability, e.g., by ultrafiltration, the said apparatus comprising a plurality of specifically designed support plates for semi-permeable membranes.
2. Description of the Prior Art
Separatory apparatuses comprised of a plurality of planar, semi-permeable membranes are well known to this art; compare, for example, French Pat. No. 2,127,155 and its Certificate of Addition No. 2,141,417. These apparatuses comprise sub-units which are formed, in particular, by the juxtaposition of a certain number of memberane support plates, the pressurized fluid to be treated, which is generally liquid, circulating in parallel between the membranes on two successive support plates (of one sub-unit), which support plates are provided with orifices towards each of their ends, for the passage of the said fluid, while this fluid circulates in series from one sub-unit to the next by virtue of the presence of so-called intermediate plates which only have one orifice towards one of their ends. The fluid which has passed through the membranes, and is referred to as the ultrafiltrate, is recovered individually for each support plate, on the edge of the latter. The support plates of such apparatuses comprise a cell on each of their faces and each cell comprises means for supporting a membrane and a woven membrane, is placed in direct contact with the said ribs, and in the case where an apparatus equipped with such support plates is used at temperatures of 80° C. or above.
SUMMARY OF THE INVENTION
Accordingly, a major object of the present invention is, in a separatory apparatus of semi-permeable membrane type, the provision of a support plate which preferably has transverse or essentially transverse ridge ribs, in the direction of flow of the pressurized liquid to be treated, but which plate does not exhibit the wrinkling/tearing disadvantages of the known plates.
More particularly according to the invention, there is featured novel separatory apparatus especially adapted for ultrafiltration and which comprises a plurality of support plates secured in a leaktight manner and spaced apart from one another at their periphery, each support plate possessing an inlet or outlet orifice at each of its ends, for the passage of the fluid to be treated, and comprising a semi-permeable membrane on each of its face surfaces, which membrane covers and defines a cell comprising ribs which are parallel to one another, the said ribs defining grooves between one another, which grooves enable discharge of the ultrafiltrate into a channel connected to the edge of the support plate on the outside of the said apparatus, characterized in that at least some of the ribs of each cell comprise means for anchoring the membrane, and in that the spacing H between the apices of the ribs of two consecutive support plates is greater than the sum of the heights (h+h) of two anchoring means of two support plates facing each other.
BRIEF DESCRIPTION OF THE DRAWINGS
The mention will be more clearly understood by reference to the annexed drawings, which illustrate, by way of example only, certain preferred embodiments of the support plates/separatory apparatus according to the invention.
FIG. 1 is an elevational front view of a support plate according to the invention;
FIG. 2 is a cross-sectional view taken along the line II--II of FIG. 1;
FIG. 3 is a partial perspective view, on a larger scale, showing a preferred embodiment and a preferred method of mutual positioning of two support plates according to the present invention;
FIG. 4 is a partial sectional view along a single rib, with protuberances, according to FIG. 3;
FIG. 5 is a partial sectional view taken perpendicular to the longitudinal axis of the plate and along ribs, without protuberances, of two support plates according to FIG. 3, the said plates having been represented only by the ribs 5 of two cells facing each other;
FIG. 6 is a schematic representation of the relative positioning of the anchoring points of two support plates facing each other;
FIG. 7 is a partial perspective view, on a larger scale, showing another embodiment and another method of mutual positioning of two support plates of an apparatus according to the present invention; and
FIG. 8 shown another embodiment of the anchoring points on the ribs of support plates of an apparatus according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
One embodiment of a support plate 1 of an apparatus according to the present invention is shown in FIGS. 1, 2 and 3. FIGS. 1 and 2 depict a plate which is known, per se, in particular from U.S. Pat. No. 4,165,082, while FIG. 3 more particularly illustrates an embodiment of the improvement made to each support plate for separatory apparatus according to the present invention. Such a plate 1, which is generally of elongate shape, possesses at least one orifice 2 towards each of its ends, for the passage of the fluid to be treated. In the embodiment of FIG. 1, the plate 1 possesses two orifices 2 at its upper extremity, whereas it possesses only one orifice at its lower extremity. Of course, the support plates 1 of the subject apparatus can have the same number of orifices 2 at each of their ends. Between the orifices 2 in each end of the support plate 1 and on each face of the latter, there is a cell 3 which comprises ribs 5 perpendicular to the longitudinal axis 4 of the support plate 1. These ribs 5 determine grooves 13 between one another. The cells 3 on each face surface of the support plate 1 are separated by a thin wall 15.
In a separatory apparatus comprising support plates 1, each of such plates 1 comprises a membrane (not shown in FIGS. 1, 2 and 3) on each of its faces, each membrane covering and defining a cell 3 and at least partially covering the peripheral edge 14 of the support plate 1. The membranes are held in a leaktight manner in the orifices 2, for example, by means of two rings which are not shown in FIGS. 1, 2 and 3, but which are described in greater detail in U.S. Pat. No. 4,165,082. These rings advantageously press the membranes in a leaktight manner against a peripheral widening 11 provided for each orifice 2.
Two consecutive support plates 1, in one apparatus, are preferably spaced apart from one another by means of a butt joint which ensures peripheral leaktightness between the two plates 1 and also the thickness of the sheet or flow of the fluid to be treated under pressure, which circulates between the membranes on two consecutive support plates 1. The support plates 1 shown in FIGS. 1 and 2 comprise, on the periphery 14 of each of its face surfaces, a peripheral groove 9 which may be discontinuous and in which a corresponding extra thickness of the butt joint separating two support plates is positioned; this ensures better positioning and better resistance of the butt joint to the action of the fluid to be treated, which circulates under pressure between the membranes on two consecutive support plates. A butt joint is not shown in FIG. 1, but the broken lines 10a and 10b show its positioning on the support plate 1, the external contour of a joint thus having essentially the same dimensions as those of the contour of the support plate (line 10b) while its internal contour (line 10a) essentially corresponds to the width of the cell 3 and extends proximate the orifices 2. On a support plate 1, a membrane (not shown) has a contour which approximatley corresponds to that of the groove 9 and openings which correspond to the orifices 2 for the passage of the fluid to be treated. In general, the membranes are cut in such a way that, near the orifices 2, same rest on the peripheral widening 11 provided on each face surface of a support plate 1. The notches 12 provided in the upper part of the support plate 1 correspond to means for holding the said support plates 1, which plates are generally employed in the vertical position in the separatory apparatus, a tube 8 for discharging the ultrafiltrate then being advantageously located towards the lower part of each support plate. Each support plate thus comprises at least one tube 8 which is connected, by means of a passage 7 which is located inside the periphery 14 of the plate (but does not pass through the plate), to a longitudinal channel 6 in communication with the grooves 13 used for recovering the ultrafiltrate.
FIG. 3 shows, in greater detail, a preferred and partial embodiment of the ribs 5 of two support plates 1 facing each other, the latter being shown in perspective and in a partial representation. This FIG. 3 further shows a method of relative positioning of two consecutive plates 1, of which only part of their respective cells has been illustrated in order to simplify the representation, the arrow at the center of the figure schematically representing the direction of flow of the fluid to be treated under pressure, which circulates between the two membranes (not shown) of the plates 1 facing each other. Of course, this direction of flow of the fluid to be treated can be opposite to that indicated by the arrow. This FIG. 3 corresponds to a section taken through a plane which is parallel to the longitudinal axis 4 of the plates 1 and perpendicular to those face surfaces of the plates which comprise the cells 3. In FIG. 3, the ribs 5 have been depicted in isosceles trapezoidal cross-section for the sake of convenient representation, but in practice the edges (16 and 17) of the ribs 5 are advantageously rounded in order to prevent the membrane, which rests directly on the top of these ribs 5, from being damaged by unduly sharp edges.
Each support plate 1 shown in FIG. 3 comprises protuberances 18 on some of its ribs 5 over the entire width of the partially shown cell 3, thereby forming an irregular profile comprising alternating portions 18, 18A which are raised and recessed relative to one another. These protuberances 18 serve as anchoring points for the membrane which covers a cell, and are uniformly distributed on the ribs 5. These protuberances 18, which form extra thicknesses on the apices 20 of the ribs 5, advantageously have the shape of an arc of a circle or the shape of a catenary curve and have a b/h ratio of between 5 and 50, and preferably between 10 and 40, b being the dimension of the base of the ridge and h being the dimension of its height, as shown in FIG. 4 which is a partial longitudinal section of a rib 5. The protuberances 18 generally have a height h of between 0.1 and 0.5 mm and preferably between 0.2 and 0.4 mm, while the pitch of two consecutive ribs (either with protuberances or without protuberances) of a cell is generally between 0.5 and 4 mm, and preferably between 1 and 3 mm. The apices 20 of the ribs 5 of a cell 3 are generally in the same plane as the periphery 14 of a support plate 1.
In general, the protuberances 18 are distributed on the ribs 5 in such a way that a membrane which is placed on the periphery 14 of a plate and on the protuberances 18 of the ribs 5 of a cell, when the membrane is being mounted on the support plate, at least partially rests on the apex 20 of each rib between two successive protuberances 18 of a rib, after the apparatus has been subjected to pressure and heat. These protuberances thus act as anchoring points for the membrane, while at the same time favoring the ultrafiltration efficiency to some extent, by increasing the ultrafiltration rate by about 15 to 20%.
However, it must be pointed out that, in an apparatus according to the present invention, the thickness H M of the sheet or flow of fluid to be treated under pressure, between the membranes 21 on two successive support plates, is greater than the sum of the heights h of two protuberances 18 which are (or are not) facing one another. Therefore, the raised portions 18 of each plate 1 terminate short of an imaginary plane P formed by the raised portions of its opposing plate 1. Thus, referring more precisely to FIG. 5, it is seen that, in an apparatus according to the present invention, two successive plates have ribs 5, the apices 20 of which are held apart from one another in every plane parallel to their opposite faces, the distance H between the apices 20 of the opposite ribs essentially corresponding to the thickness of the sheet or flow of fluid circulating between the membranes 21 on two consecutive support plates.
In the partially shown apparatus according to FIG. 3, the support plates 1 have ribs 5 with protuberances on every third rib 5, in each cell, and the protuberances are staggered from one rib 5 with protuberances to the next, in one and the same cell. Furthermore, the ribs 5 with protuberances 18 face one another from one plate 1 to the next, opposing protuberances 18 being staggered relative to one another. However, with the same configuration of protuberances 18, every successive rib 5 can have protuberances. More generally, the pitch of the ribs 5 with protuberances 18, namely, the distance between two successive ribs 5 with protuberances, in one and the same cell, can be between 1 and 75 mm. In general, the number of anchoring points or protuberances 18 on a rib 5 is 2 to 20 per 100 mm length of the rib in question.
It is also possible, in an apparatus according to the present invention, for each support plate to comprise, in each cell, ribs 5 of which the protuberances 18 are not staggered between two successive ribs 5 bearing protuberances. In this case, a rib, with protuberances, of a support plate is advantageously opposite a rib, without protuberances, of the adjacent plate, the protuberances of each plate being laterally staggered relative to one another. This method of relative positioning of the ribs, with protuberances, of two consecutive support plates is represented schematically in FIG. 6, the protuberances on a rib being shown in solid lines for one support plate and in dotted lines for the ribs of the support plate facing it, and the ribs, without protuberances, of each support plate not being shown.
An apparatus equipped with 6 sub-units, each comprising 24 support plates 1 such as those described above and shown in FIGS. 1 to 5, has been produced, in particular, with support plates having the following dimensions:
______________________________________Thickness of a support plate: 5.5 mmDistance between orifices 2 from One end of 770 mmthe support plate to the other:Width of each cell 3: 125 mmPitch of the ribs 5 in a cell perpendicular to 1.5 mmthe longitudinal axis 4 of each support plate:Height of the ribs 5: 1.2 mmWidth of the base of the ribs 5: 0.9 mmWidth of the apex 20 of the ribs 5: 0.6 mmPitch of the ribs 5 with protuberances 18: 4.5 mmHeight h of each protuberance 18: 0.3 mmLength of the base of the protuberances 18 on 4 mmthe apex 20 of a rib:Pitch of the ridges 18 on a rib: 8 mmThickness H.sub.M of the sheet or flow of fluid to be 1.4 mmtreated, between the membranes 21 resting on theapices 20 of the ribs 5 of two plates facingone another.______________________________________
With this apparatus, there was no wrinkle formation or tearing of the membranes after stopping and restarting the apparatus 20 times, under a relative pressure of 4 bars using a temperature cycle of from 15 to 80 degrees.
With an identical apparatus which did not, however, comprise any protuberances on the ribs, the membrane tore after stopping and restarting the apparatus but twice, under the same pressure and temperature conditions.
In both cases, the membrane used was a woven membrane patented by the Societe Rhone-Poulenc Industries under French Pat. No. 2,331,602. More precisely, the membrane used was obtained from a mixture of 80% by weight of a polysulfone containing a plurality of units of the formula: ##STR1## (and sold by the Societe Union Carbide under the tradename, P 1 700) and 20% by weight of the same polymer after sulfonation, in the form of its sodium salt, this sulfonated polymer having an exchange capacity of 950 meq/kg.
The weft of this membrane had a thickness of 120 microns, a mesh size of 75 microns and a tensile strength of 55 kg for a 50 mm×100 mm test piece. This woven membrane was asymmetric and had a total thickness of 200 microns and a permeability to water of 20,000 liters/day.m 2 (liters per day per square meter) under a relative pressure of 2 bars. The cut-off threshold of this membrane to proteins was 20,000.
With this apparatus, it was also possible to increase the ultrafiltration rate by about 15 to 20%, relative to the same apparatus equipped with support plates of which the ribs did not have any protuberances. This difference in the ultrafiltration rate was demonstrated by carrying out the ultrafiltration, at 25° C., under a relative pressure of 2 bars and at a tangential speed, at the level of the membranes, of 2.5 meters/second, of an emulsion of cutting oil, having the following composition by weight:
______________________________________Oil, reference 100 NEUTRAL, sold by the CFR 4%(Compagnie Francaise de Raffinage):Emulsifier, trademark ADOGIL 58, manufactured 1%by OROGIL:Water: 95%______________________________________
Although the apparatus described above has been shown with support plates 1 having ribs 5 which are perpendicular to their longitudinal axis 4, which corresponds to a preferred embodiment, the apparatus according to the invention can, however, have support plates with ribs which are not perpendicular to their longitudinal axis 4. For example, such ribs 5 can form an angle of between 40° and 90° with the longitudinal axis 4 of a support plate 1.
The protuberances 18 of the ribs 5 of a support plate 1 can be produced, for example, by electro-erosion in the corresponding grooves in the mold of the plate which is advantageously to be injection-molded under pressure. These protuberances 18 can also be produced when the grooves in the molds are being cut with a milling tool, by forcing the latter down a little further at the points where it is desired to have protuberances 18 on the rib of a support plate 1.
Numerous variants of an apparatus according to the present invention are well within the skill in the art. By way of non-limiting examples, FIGS. 7 and 8 show two embodiments of such variants.
FIG. 7 is a partial view in perspective of two support plates facing one another, as in FIG. 3, but, in this embodiment, the support plates 1 each comprise cells of which some of the ribs 5 have membrane anchoring points consisting of notches 19, thereby forming an irregular profile comprising alternating portions 19A, 19 which are raised and recessed relative to one another. These notches 19 and the ribs 5 of the support plates according to FIG. 7 can have all the characteristics of the protuberances and the ribs 5 of the support plates according to the FIG. 3, the only difference being that the anchoring points consisting of the notches 17 do not form extra thicknesses on the ribs 5. These notches 19 thus correspond to the removal of material from the ribs 5 and preferably have the same shape as the protuberances 18 considered above. All the variants mentioned for the support plates with protuberances 18 can thus apply to the support plates of which the ribs 5 have notches 19, especially as regards the distribution of these notches 19 on a rib 5, the pitch of the ribs 5 with notches, the staggering of the notches, the angle formed by the ribs 5 with the longitudinal axis 4 of a support plate 1, and the relationship whereby the raised portions 19A terminate short of an imaginary plane formed by the raised portions of an opposing plate 1. In particular in the apparatus according to FIG. 7, on each cell of each support plate 1, a membrane rests on the apex 20 of each rib, between two successive notches 19 on a rib 5, and curves inwards, at least partially, into each notch 19 after the apparatus has been subjected to pressure and heat. These notches 19 thus act as anchoring points for the membrane. The notches 19 can be produced, for example, by milling an injection-molded plate or by milling the molds used for the injection-molding of the support plates. In the latter case, the milling tool used to cut the grooves in the mold is forced down into the grooves a little less at the points where notches are to appear on the ribs of the support plates.
FIG. 8 shows another embodiment of membrane anchoring points on the ribs 5 of each cell of a support plate. These anchoring points consist of spikes 22 which are advantageously in the form of small truncated pyramids with a circular base, of which the width of the base b essentially corresponds to the width of the apex 20 of each rib, and of which the height h is such that the ratio b/h is between 1 and 10, and preferably between 2 and 5. All the variants mentioned for the ribs with protuberances 18 can apply to support plates having ribs with spikes 22, especially as regards the distribution of these spikes 22 on a rib 5, the pitch of the ribs with spikes 22, the staggering of the spikes, and the angle formed by the ribs 5 with the longitudinal axis 4 of each support plate 1. In particular, with an apparatus equipped with support plates 1 having ribs 5 with spikes 22, for each cell, a membrane rests, at least partially, on the apex 20 of each rib 5, between two successive spikes 22 on a rib 5, and the thickness H M of the sheet of fluid to be treated under pressure, between the membranes of two successive support plates 1, is greater than the sum of the heights h of two spikes 22. These spikes 22 are produced, for example, by milling the molds in which the plates are injection-molded.
While the invention has been described in terms of various preferred embodiments, the skilled artisan will appreciate that various modifications, substitutions, omissions, and changes may be made without departing from the spirit thereof. Accordingly, it is intended that the scope of the present invention be limited solely by the scope of the following claims. | Separatory, e.g., ultrafiltration apparatus including a plurality of semi-permeable membranes and a plurality of ridge ribbed support members therefor, is provided with means for anchoring said membranes to and between successive supports. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. provisional application Ser. No. 61/074,727 filed on Jun. 23, 2008, incorporated herein by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] This invention pertains generally to hydroponic plant growing, more particularly to hydroponic plant growing systems with oxygenated nutrient solutions, and still more particularly to a hydroponic plant growing system with oxygenated nutrient solutions with no more than a single pump per hydroponic planter providing both the oxygenation and flow of the nutrient fluid.
[0005] 2. Description of Related Art
[0006] Traditional hydroponic growing systems appear to use a plurality of pumps to circulate nutrient fluids among the root systems, and still more pumps to oxygenate the nutrient fluid so that the nutrient fluids may more closely resemble the growing conditions of plants in traditional dirt growth media. Such resulting hydroponic systems tend to be complex, costly, inefficient, and cumbersome.
BRIEF SUMMARY OF THE INVENTION
[0007] An aspect of the invention is a hydroponic growing system, which may comprise: a hydroponic planter; and means for pumping a nutrient fluid to the hydroponic planter. The nutrient fluid is generally predominantly water, but will generally have additional nutrients and micronutrients suitable for plant growth. The means for pumping may comprise a sealed nutrient container that contains at least some of the nutrient fluid; a fluid coupling between the hydroponic planter and the sealed nutrient container; and an air pump fluidly coupled to the sealed nutrient container through an air coupling, whereby the sealed nutrient container nutrient fluid becomes pressurized upon activation of the air pump; wherein the pressurized nutrient fluid is initially forced through the fluid coupling to the hydroponic planter. The fluid coupling is generally a hose or tube, but may be otherwise hard plumbed so as to fluidly connect the hydroponic planter and the sealed nutrient container.
[0008] In the system above, the air pump is the only pump present. This single pump implementation tends to reduce energy consumption and increase the system simplicity and efficiency. The corresponding increase in efficiency allows for off-grid operation with very low energy costs, as may be supplied with photovoltaic cells. With the single pump, air is subsequently forced through the fluid coupling to the hydroponic planter after the nutrient fluid has reached a sufficiently low level in the sealed nutrient container, thereafter oxygenating the nutrient fluid in the hydroponic planter.
[0009] A timer may be used to control a frequency and duration of activation of the air pump described above. The timer and air pump above may be powered by a battery. These frequencies and durations may be the same or different depending on the growth requirements of a particular plant or crop. Additionally, the frequencies and durations may be preprogrammed into the timer/controller so as to match the growing requirements of the particular species of plants to be grown in the particular system.
[0010] In the system above, a photovoltaic panel may be connected to the battery, wherein the battery is recharged upon a sufficient light flux incident upon the photovoltaic panel. Alternatively, a recharger capable of connecting to a local alternating current power system may be used to recharge the battery.
[0011] The air pump may be either alternating current (AC) or direct current (DC) powered. Similarly, the timer may also be AC or DC powered. Should either the air pump or the timer require AC, then an inverter may be disposed between the batter and the air pump, wherein the inverter converts the battery direct current (DC) into alternating current (AC) suitable for the air pump or timer, as required.
[0012] In the hydroponic growing system described above, the sealed nutrient container is disposed at a lower elevation than the hydroponic planter. In this case, the nutrient fluid returns from the hydroponic planter to the sealed nutrient container through the fluid coupling when the sealed nutrient container supply fluid is no longer pressurized. This return is achieved through simple hydraulic flow due to different heights of the hydroponic planter and the sealed nutrient container.
[0013] However, if the sealed nutrient container is completely sealed except for the fluid coupling and the air coupling, then the air pumped through the air coupling would pressurize the sealed nutrient container to an extent where there would be no substantial return flow of the nutrient fluid back into the sealed nutrient container, and the pressure in the sealed container would equal that of the hydraulic head in the fluid coupling. For this reason, a small orifice is introduced to allow for the slow depressurization of the sealed nutrient container. This small orifice may be disposed on the sealed nutrient container, the portion of the fluid coupling that enters the sealed nutrient container (allowing pressurized air to escape through the fluid coupling to the hydroponic planter), or in the air coupling (external to the sealed nutrient container, so as to release the air to ambient pressure). Should the air pump be sufficient leaky, an orifice may not be needed, as the backflow through the air pump may provide a sufficient depressurization rate.
[0014] In an embodiment where a cap seals the sealed nutrient container, with both the air coupling and fluid coupling passing through the cap, an orifice may be introduced into the cap.
[0015] By orifice, as used above, it is meant that there is an opening allowing some small percentage of the air pump flow to escape from the pressurized air space within the sealed nutrient container.
[0016] Another aspect of the invention is a method of periodically supplying a nutrient fluid to a hydroponic planter, and thereafter aerating the nutrient fluid in the hydroponic planter, comprising: providing a hydroponic planter; and means for pumping a nutrient fluid to the hydroponic planter.
[0017] This method may additionally comprise: pressurizing a sealed nutrient container with an air pump, so as to initially force to the hydroponic planter a nutrient fluid stored within the sealed nutrient container; and after at least some of the nutrient fluid has been pumped to the hydroponic planter, then pumping air to the hydroponic planter; and after a period of time pumping air to the hydroponic planter, turning off the air pump, thereby allowing nutrient fluid previously pumped to the hydroponic planter to return to the sealed nutrient container through a nutrient coupling. This return of the nutrient fluid from the hydroponic planter to the sealed nutrient container occurs due to a hydraulic head generated by the hydroponic planter being higher than the sealed nutrient container.
[0018] Alternatively stated, a method of supplying a nutrient fluid and air to a hydroponic planter, may comprise: providing a container with a nutrient fluid therein; coupling the container to a hydroponic planter with a fluid coupling; pressurizing the container with air to initially force the nutrient fluid through the fluid coupling to the hydroponic planter; after at least some of the nutrient fluid has been forced to the hydroponic planter, forcing air through the fluid coupling to the hydroponic planter; and after a period of time wherein air is forced to the hydroponic planter, depressurizing the container to allow excess nutrient fluid previously forced to the hydroponic planter to return to the container through the fluid coupling.
[0019] The method above may further comprise controlling a frequency and duration of the pressurizing step with a timer. Here, at least some of the nutrient fluid previously forced to the hydroponic planter returns to the container under the force of gravity through the fluid coupling.
[0020] The method above may further comprise pressuring the container with a single electrically powered air pump.
[0021] This method may also comprise recharging a rechargeable battery used to power the air pump. Further, the method may also comprise controlling the frequency and duration of the pressurizing step with a timer.
[0022] In the method described above, the rechargeable battery may be selected from a group of rechargeable batteries consisting of: a flooded lead acid batter, a gel-cell battery, an absorbed glass mat (AGM) battery, a Ni-Cad batter, a nickel-metal-hydride (NiMH) battery, a rechargeable alkaline battery.
[0023] The method above may further comprise recharging the rechargeable battery with a photovoltaic cell.
[0024] The method above may be rendered into a hydroponic aeration apparatus, capable of performing the steps described above.
[0025] In the method above, the means for pumping may comprise providing regulated air from a compressed air source. Ultimately, such compressed air source may originate from a container of pressurized air, a large scale compressor capable of simultaneously supplying air to one or more of the hydroponic systems described herein. The air pump may be powered by a power source selected from a group of power sources consisting of: direct current (DC) electricity, alternating current (AC) electricity, a mechanical displacement, and a mechanical rotation.
[0026] In the method above, depressurizing the sealed nutrient container may be achieved by using an orifice disposed thereupon. Alternatively, depressurizing the sealed nutrient container may be achieved by allowing pressurized air within the sealed nutrient container to return through an orifice disposed on the fluid coupling within the sealed nutrient container, or an orifice disposed on the air coupling, or a leak disposed within the air pump.
[0027] A still further aspect of the invention is an integrated hydroponic aeration system, comprising: an integrated assembly, comprising: an air pump chamber that houses an air pump; a sealed nutrient container that may hold a nutrient fluid, wherein the sealed nutrient container may be selectively pressurized by the air pump; a hydroponic planter fluidly connected to the sealed nutrient container by a nutrient coupling.
[0028] In the integrated hydroponic aeration system above, within the integrated assembly, the hydroponic planter is disposed at a higher elevation than the sealed nutrient container. This higher elevation of the hydroponic planter allows for the gravity drain-back of the nutrient fluid after the termination of a feeding cycle.
[0029] In all of the systems described above, aeration, and hence oxygenation of the nutrient fluid may be accomplished by extending the air coupling into the sealed nutrient container, and terminating the air coupling in a bubbler. In this manner, air pumped by the air pump will bubble through the nutrient fluid prior to or simultaneously with forcing of the nutrient fluid toward the hydroponic planter.
[0030] In still another embodiment, the bubbler may be disposed below a terminus of the nutrient coupling within the sealed nutrient container. In this embodiment, oxygenation through the bubbling action occurs while the nutrient fluid is pumped to the hydroponic planter.
[0031] 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)
[0032] The invention will be more fully understood by reference to the following drawings which are for illustrative purposes only:
[0033] FIG. 1 is a perspective diagram of an air-pressure fed hydroponic growing system, where a low pressure air pump is used to replace evaporation losses in the hydroponic nutrient bed, and to aerate the nutrient fluid in the nutrient bed.
[0034] FIG. 2 is a perspective drawing of one implementation of the air-pressure fed hydroponic growing system of FIG. 1 .
[0035] FIG. 3 is a detailed perspective view of a sealed nutrient container, showing the entrance and egress of air and fluid couplings, and an air pressure exit orifice.
[0036] FIG. 4 is a perspective drawing of one implementation of a single air-pumped air-pressure fed hydroponic system of FIG. 1 being used with a plenum to instead feed several hydroponic planters by using several of the sealed nutrient containers of FIG. 3 .
[0037] FIG. 5 is a perspective view of an integrated hydroponic system similar in function to the system of FIG. 1 , however, the side walls of the structure form the hydroponic planter and sides of accessed bins containing the sealed nutrient container below the air pump.
[0038] FIG. 6 is a perspective view of a larger scale version of an integrated hydroponic system, with the air pump and sealed nutrient supply laterally spaced apart, perhaps more suited to nursery growing scales.
[0039] FIG. 7 is a perspective view of a larger scale version of an integrated hydroponic system, with an air pump external to the sealed nutrient supply, perhaps suited to home garden growing scales.
[0040] FIG. 8 is a perspective view of a still larger scale version of an integrated hydroponic system mounted on rail cars, with one or more modified flat cars for growing, and a tanker car supplying nutrient fluid or water to make up for evaporative losses.
[0041] FIG. 9 is a perspective view of an attractively packaged implementation of an integrated hydroponic system, suitable for patio, indoor, or other low cost applications.
[0042] FIGS. 10A-10D are perspective views of variations on the sealed nutrient container of FIG. 3 where direct oxygenation of the nutrient fluid is achieved prior to pumping to the hydroponic planter.
DETAILED DESCRIPTION OF THE INVENTION
Definitions
[0043] The following terms are used herein and are thus defined to assist in understanding the description of the invention(s). Those having skill in the art will understand that these terms are not immutably defined and that the terms should be interpreted using not only the following definitions but variations thereof as appropriate within the context of the invention(s).
[0044] “Nutrient fluid” means any dissolved or suspended element or compound suspended in a substantially water medium.
[0045] “Hose” means a hollow tube designed to carry fluids from one location to another. Hoses, as used herein, include tubes or pipes (pipe usually refers to a rigid tube) whereas the hose is usually flexible, or more generally tubing. The shape of a hose is usually, but not necessarily, cylindrical (having a circular cross section).
[0046] “Air coupling” means a hose that passes air.
[0047] “Fluid coupling” means a hose that passes both nutrient fluid and air.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0048] Referring more specifically to the drawings, for illustrative purposes the present invention is embodied in the apparatus generally shown in FIG. 1 through FIG. 10D . 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.
[0049] The present invention pertains to a hydroponic growing system that appears to have very high efficiency, sufficient to use low power photovoltaic or other relatively low power sources for operation.
[0050] Refer now to FIG. 1 , which is a diagram of a single pump nutrient feed and aeration system 100 . Here, an air compressor 102 is electrically connected 104 to a power source 106 . Here, power source 106 is shown as an inverter, but other power sources are possible, such as direct current (DC) battery power, DC solar power, or others. The inverter 106 is in turn electrically connected 108 to one or more rechargeable storage batteries 110 .
[0051] These storage batteries 110 are nominally 12 V, but may be at other voltages as designed or desired. One application would be to use deep cycle lead-acid storage batteries 110 , although maintenance free, Absorbed Glass Mat (AGM), or gel-cell batteries may also be used.
[0052] If one desired to depart from the lead-acid storage batteries, lithium, nickel-metal-hydride, or other more expensive power storage devices could be used.
[0053] Regardless of the type of storage battery 110 , ultimately the battery 110 would require replenishment or recharging of energy used to power the inverter 106 , or the air pump 102 (if directly connected to the air pump 102 ).
[0054] Such recharging of the storage battery 110 could readily be accomplished through the use of a photovoltaic controller 112 powered by an appropriate solar panel 114 . Depending on the design of the photovoltaic panel 114 , a photovoltaic controller 112 may not be required and a simple blocking diode (not shown) may be used to prevent drains by the photovoltaic panel 114 at night. The blocking diode may also be incorporated within the solar panel 114 .
[0055] Finally, for indoor systems, or systems close to electrical power sources, a direct recharging of the storage battery 110 may be used via typical residential electrical plugs (not shown here).
[0056] An air hose 116 may be used to connect the air compressor 102 to a nutrient storage fitting 118 . This nutrient storage fitting 118 allows a substantially pressure-tight fitting with nutrient storage container 120 . Within the nutrient storage container 120 is a nutrient solution 122 . The nutrient solution 122 comprises water, with the nutrients required for successful plant growth.
[0057] The nutrient solution 122 is forced through a nutrient tube 124 that passes through the nutrient storage fitting 118 , and ultimately passes through a waterproof fitting 126 in a hydroponic planter 128 where plants 130 may be grown.
[0058] Within the hydroponic planter 128 , an inert rooting medium (not shown) allows mechanical attachment for plant roots 132 .
[0059] During operation, the air compressor 102 supplies a pressurized air supply to air hose 116 , which in turn pressurizes the interior of the nutrient storage container 120 . This pressurized air, in turn, forces the nutrient solution 122 through the nutrient tube 124 towards the hydroponic planter 128 . The nutrient solution 122 is pumped until the level of the nutrient solution 122 in the nutrient storage container 120 lies below the inlet terminus of the nutrient tube 124 within the nutrient storage container 120 .
[0060] When this low level of nutrient solution 122 is reached, the pressurized air within the nutrient storage container 120 is forced through the nutrient tube 124 to the hydroponic planter 128 , where the plant roots 132 are oxygenated through the bubbles of forced air. In a small hydroponic planter, it appears that full oxygenation of the nutrient solution (now almost completely residing in the hydroponic planter 128 ) occurs in about 15 minutes of bubbling.
[0061] The bubbling, which occurs within the nutrient tube 124 and within the nutrient solution now resident in the hydroponic planter 128 , is due to the hydrostatic pressure of the nutrient solution as it attempts to return to the nutrient storage container 120 through the nutrient tube 124 . Clearly, for this to successfully function, the nutrient storage container 120 must be below the hydraulic grade line of the hydroponic planter 128 .
[0062] After a period of activation of the air compressor 102 (typically about 15 minutes, depending on the size of the hydroponic planter 128 and the flow rate and volume of nutrient solution originally present in the nutrient storage container 120 ), the air pump or compressor 102 is stopped via a timer controller 134 . With no continuing pressure being applied to the interior of the nutrient storage container 120 , nutrient solution flows from the hydroponic planter 128 through the nutrient tube 124 back to the nutrient storage container 120 . When completed, most of the nutrient solution has returned to the nutrient storage container 120 , except for a residual wetted amount remaining in the hydroponic planter 128 on the plant roots 132 and inert growing medium.
[0063] With the return of most of the nutrient solution, the plant roots 132 have atmospheric air drawn into their interstitial spaces, allowing even more oxygenation of the roots 132 . Oxygenation of the roots is important, since oxygen prevents growth of anaerobic bacteria, which may otherwise rot the plant roots 132 .
[0064] The cycle of filling the hydroponic planter 128 and draining the nutrient solution back to the nutrient storage container 120 may be repeated as desired in frequency and duration for optimal plant 130 growth.
[0065] In an indoor growing environment, the photovoltaic panel 114 may be incorporated into a hood of a growing light (not shown) providing the electricity needed to charge the storage battery and operate the air pump 102 and timer controller 134 . This would “recycle” some amount of the cost of the high powered growing light. In other words, if the photovoltaic panel is closely disposed adjacent to the growing light, then there should be sufficient light energy absorbed so that the photovoltaic cell electricity may be produced for charging or operating the system, when typically growing occurs in large scale green houses. Electricity is less expensive in low demand times of the day, which are typically night and evening.
[0066] Refer now to FIG. 2 , which is a drawing of one seemingly elegant implementation 200 of the schematic of FIG. 1 . Here, wooden (or other suitable structural material) legs 202 attach at a top platform 204 and are interconnected with cross braces 206 . The interconnected cross braces 206 support an integrated nutrient hydroponic planter 208 that is steadied by a clearance hole in the top platform 204 .
[0067] The integrated hydroponic planter 208 comprises a cylindrical tube with three major regions. A topmost region 210 where plant roots may grow, a nutrient storage region 212 , where the growing nutrient is stored, and an air compressor region 214 , where an air compressor or pump 216 resides. A base 218 allows for mounting of the air compressor 216 . The base 218 may be either fixed, or removable. If removable, the base 218 would allow for replacement or repair of the air compressor or pump 216 .
[0068] Air compressor or pump 216 has an output tube 220 that passes from the output of the air compressor or pump 216 through a lower seal 222 to the nutrient storage region 212 , terminating 224 near the top. A nutrient tube 226 projects down from an upper seal 228 (forming a waterproof bottom of the topmost region 210 ) until it nearly reaches the bottom of the nutrient storage region 212 , allowing fluid connection between the nutrient storage region 212 and the topmost region 210 .
[0069] It should be noted that the topmost region 210 , the nutrient storage region 212 , and the air compressor region 214 are shown as if they were transparent in this FIG. 2 drawing. Should the topmost region 210 and nutrient storage region 212 actually be transparent, inadvertent algae growth would be problematic. Therefore, at least the topmost region 210 and the nutrient storage region 212 should be optically opaque. This opacity then forestalls the algae growth problem.
[0070] During use, the air compressor or pump 216 , which may be a typical aquarium pump or other more powerful pump, may be powered by an electrical connection to a rechargeable battery 230 , which may have a timer controller 232 to control the operational times and durations of the air compressor or pump 216 . The rechargeable battery 230 may in turn be recharged either by a photovoltaic cell 234 , or a wall charger 236 . The air compressor or pump 216 supplies pressurized air to the output tube 220 , which in turn pressurizes the nutrient storage region 212 . This pressurization of the nutrient storage region 212 forces nutrient solution up through the nutrient tube 226 and into the topmost region 210 where roots 238 of the plant (or plants) 240 is growing.
[0071] After a sufficient time of operation of the air compressor or pump 216 , the nutrient solution has largely been moved from the nutrient storage region 212 to the topmost region 210 , and the air supplied by the air compressor 216 continues to bubble up through the nutrient tube 226 into the topmost region 210 and the plant 240 roots 238 . This continued air bubbling allows for thorough oxygenation of the nutrient solution.
[0072] For an integrated hydroponic system 200 of this size, early estimates are that the air compressor 216 should be run about 15 minutes to fully oxygenate the nutrient solution in the plant 240 roots 238 . It also appears that five (5) of these cycles daily appear sufficient for thriving plant 240 growth. Horticultural testing is continuing with a goal of optimizing and further verifying these cycle parameters.
[0073] Refer now to FIG. 3 , which is an enlarged perspective view of a typical sealed nutrient container 300 . Here, a container 302 is sealed by a cap 304 . The cap may be either press fit or screwed onto the container 302 , so long as an air-tight fit is obtained between the cap 304 and the container 302 . Into the cap 304 passes an air coupling 306 , which then passes through the cap 304 to the inside 308 of the container 302 . Container 302 is typically opaque, thereby forestalling any algae growth problems.
[0074] In this FIG. 3 , the air coupling 306 is a tube or hose that passes through the cap 304 , although other air-tight connections are readily obtained, such as a tube connection to a rigid pipe passed partially or completely through the cap 304 . Such a rigid pipe may be plastic, glass, metal, or some other functionally equivalent material.
[0075] Similarly, a fluid coupling 310 passes through the cap 304 extending for a longer distance 312 below the cap 304 . This longer distance 312 lowers below the resting level of nutrient fluid 314 , to a distance 316 typically very close to the bottom of the container 302 . Typical close distances may range from ½ to 3 diameters of the fluid coupling 310 , and may range from 1-20 mm.
[0076] It should be noted that either or both of the air coupling 306 and the fluid coupling 310 may, instead of being passed directly through the cap 304 , may instead be passed through sealed feed throughs 318 .
[0077] In operation, the cap 304 , the container 302 , the air coupling 306 and the fluid coupling 310 are sealed so that a pressure generated at the air coupling 306 results in nutrient fluid 314 being passed upward through the fluid coupling 310 with no loss of air from the environs of the container 302 .
[0078] However, if there is no air loss in the system above, then when the air coupling 306 is no longer pressurized, nutrient fluid 314 will only partially drain back (presuming that the fluid coupling 310 terminus is above the container 302 ) until the container 302 is pressurized to an amount equal to the hydraulic head of the nutrient fluid 314 . Thus, an orifice 320 is added to pass through the cap 304 .
[0079] The orifice 320 is sufficiently small that the nutrient fluid 314 is still mostly pumped by the air coupling 306 into the fluid coupling 310 , with some small proportion of the pumped air from the air coupling 306 exiting the orifice 320 . Then, when the pumping time is concluded, the nutrient fluid 314 passes back to the container 302 , displacing air above the nutrient fluid 312 level through the orifice 320 .
[0080] Although the orifice 320 is shown here in the cap 304 , it may reside in the fluid coupling 312 within the container 302 (thereby venting the air through the fluid coupling 310 ), in the air coupling 306 exterior to the container 302 , or disposed separately on the container 302 above the nutrient fluid 314 nominal filling level.
[0081] While an orifice 320 is the simplest implementation, a check valve (not shown) may replace the orifice 320 , where air is allowed to exit, but nutrient fluid 314 is not. Such a replacement of the orifice 320 would preclude spillage of nutrient fluid 314 in the event of the container 302 turning over with the cap 304 in place.
[0082] Still another functionally equivalent replacement of the orifice 320 would be to use Gore-Tex® fabric, where air and water vapor are allowed exit due to the micro-porosity of the material, but liquid (which is mostly water) nutrient fluid 314 is not allowed to exit.
[0083] Refer now to FIG. 4 , which is one implementation 400 of a single air-pumped 402 air-pressure fed hydroponic system of FIG. 1 being used with a plenum to instead feed several hydroponic planters by using several of the sealed nutrient containers 300 of FIG. 3 . Here, a single air pump 402 is fluidly connected 404 to a plenum 406 . The individual hose connections 408 on the plenum 406 may be traditional air pressure quick disconnects, or may simply be nipples upon which vinyl air hose is pressed upon. Air couplings 410 may include additional valves 412 to terminate or regulate flow in the air couplings 410 , or may pass directly to the individual sealed nutrient containers 300 previously described in FIG. 3 .
[0084] From the individual sealed nutrient containers 300 , nutrient fluid is fed through nutrient couplings 414 to hydroponic planters 416 , where individual or groups of plants 418 are grown.
[0085] One benefit of this FIG. 4 system is that different nutrient fluid may be used depending on the plant to be grown. Thus, if tomatoes are to be grown, one nutrient fluid may be use, however, if rice is to be grown, another nutrient fluid may be used.
[0086] Additionally, even though hydroponic planters and sealed nutrient containers are indicated in the FIG. 4 as the same size, they need not be. That is, the individual hydroponic planter and sealed nutrient containers 300 may be sized as sets, allowing the single air pump 402 to be used to hydroponically grow crops in greatly varying sizes of hydroponic planters 416 .
[0087] Further, air regulators 418 may be introduced into the air couplings 410 to properly regulate the pressure applied to the variously sized sealed nutrient containers 300 further accommodating hydroponic planter 416 of greatly varying sizes.
[0088] For the sake of clarity, the timer, which controls the frequency and duration of powering the air pump 402 , has been omitted from the FIG. 4 , as has the power source for the air pump 402 . These would be similar in nature to those previously shown in FIG. 1 .
[0089] Refer now to FIG. 5 , which is another variation 500 of the single pump hydroponic system of FIG. 1 . Here, the walls 502 form a square or rectangular cross section, thereby forming both the structural support and hydroponic planter 504 section of the system. A sealed nutrient container 300 previously described in FIG. 3 is stored in a lower section 506 of the hydroponic system 500 . A middle section 508 is formed for the routing of the air coupling 510 between the air pump 512 and the sealed nutrient container 300 .
[0090] An air pump 512 access door 514 allows access to the air pump 512 and its battery (or other) power source 516 . One or more hinges 518 allow for the opening and closing of the access door 514 . Similarly, a nutrient access door 520 is allowed by one or more second hinges 522 , allowing access to filling and checking the nutrient level 524 in the sealed nutrient container 300 .
[0091] Operation in this implementation is similar to the previous embodiments. Here, a timer 526 controls the frequency and duration of pump 512 activation. When activated, the air pump 512 forces pressurized air down the air tube 528 , thereby pressurizing nutrient container 300 , and forcing nutrient solution 524 up the nutrient tube 510 to exit and flow into the hydroponic planter 504 inert growing medium 530 . The junction 532 between the nutrient tube 510 and the hydroponic planter 504 is water tight, preventing nutrient solution from otherwise flooding the middle section 508 air pump 512 and other components. An inverted strainer or other mesh 534 sits atop the junction 532 preventing the growing medium 530 from passing into and clogging the nutrient tube 510 .
[0092] Finally, operational indicators 536 provide a status of operation (air pumping or not) or nutrient solution levels. These operational indicators 536 may connect to the timer 526 , or other sensors capable of detecting nutrient solution level in the nutrient container 300 . Access to either the air pump 512 or sealed nutrient container 300 is by operation of latches 538 or 540 , respectively.
[0093] Refer now to FIG. 6 , which is a larger scale version 600 of an integrated hydroponic system, with the air pump 602 battery 604 and sealed nutrient supply 606 laterally spaced apart. An access door 608 is secured with a latch mechanism 610 , where the door 608 pivots about hinges 612 . Fill port 614 allows for filling of the sealed nutrient container 606 , which is of a generalized rectilinear shape in this embodiment. The shape of the sealed nutrient container 606 may comprise a sloping region (not shown) to a lowest point drained by a drain line 616 , which may be sealed with a drain plug 618 .
[0094] Between the fill port 614 and the drain line 616 , the sealed nutrient container 606 may readily be filled or drained, respectively, through the use of the access door 608 and opening of the drain plug 618 .
[0095] The access door 608 also allows repair or maintenance access to the air pump 602 , battery 604 , or other electronics (not shown). An external wall plug 620 allows for the powering of the integrated hydroponic system 600 . For off-grid operation, one or more photovoltaic panels 622 may be used to power the air pump 602 directly, or to recharge the battery 604 , depending on the particular options desired.
[0096] In operation, the air pump 602 flows air through air coupling 624 to a cap 626 with a pressure release orifice 628 as described above to allow for drain back of the nutrient fluid after air pump 602 activation has been concluded. The air coupling 624 pressurizes the sealed nutrient container 606 , thereby forcing nutrient fluid up the nutrient coupling 630 , which extends 632 to a relatively low point in the sealed nutrient container 606 .
[0097] The nutrient coupling 630 continues to the hydroponic planter 634 through a leak tight connection 636 in the base of the hydroponic planter 634 . The leak tight connection 636 is covered with a mesh, screen, or strainer 638 so as to keep hydroponic growth medium (not shown here for clarity) in the hydroponic planter 634 from flowing into and potentially clogging the nutrient coupling 630 .
[0098] Refer now to FIG. 7 , which is a separable large-scale hydroponic planter system of the present invention 700 . Here, an external air source 702 (which is shown here as an air pump, but it may also be an external air compressor with or without pressure regulation), periodically flows air through an air coupling 704 to a cap 706 that seals a rectangular nutrient container 708 . Nutrient coupling 710 descends through the cap 706 to nearly the bottom of the nutrient container 708 , and passes through the cap 706 to terminate 712 in the hydroponic planter 714 .
[0099] The rectangular nutrient container 708 may be filled either by the cap 706 , or by an exterior fill cap 716 . As previously discussed, small air orifice 718 vents the sealed rectangular nutrient container 708 , thereby allowing for nutrient fluid to pass from the hydroponic planter 714 , through a strainer or mesh 720 (so as to exclude the inert growing medium in the hydroponic planter 714 from the nutrient coupling 710 ), and finally return to the rectangular nutrient container 708 . Here, the small air orifice 718 is shown on the body of the rectangular nutrient container 708 , although it could also be disposed on the cap 706 . Again, the small air orifice 718 allows for the nutrient fluid to return to the rectangular nutrient container 708 by gravity return. Finally, a drain port 722 is disposed near the lowest point of the rectangular nutrient container 708 , allowing for draining of the nutrient fluid as needed.
[0100] Refer now to FIG. 8 , where we find a railroad embodiment of the single pump hydroponic system invention 800 . Here, one or more modified flat cars 802 obtain either direct nutrient fluid, or refilling of evaporative losses from the tanker car 804 . A lower section 806 of the modified flat car 802 contains an air pump (not shown) and any power storage systems, such as rechargeable batteries (also not shown). A hydroponic planter 808 lies above the lower section 806 , where inert growing medium (not shown) and growing plants (not shown) reside.
[0101] Since the plants may be sensitive to too much sunlight, mesh sun screens 810 are supported 812 above the hydroponic planter 808 . Foldable photovoltaic panels 814 pivot down from the sides of the modified flat car 802 to obtain power for the air pump in the lower section 806 .
[0102] In some embodiments, either all, or a limited amount of nutrient fluid may be stored in a tank 816 suspended below the modified flat car 802 . However, greater flexibility and scale may be obtained by using the separate tanker car 804 with a plurality of modified flat cars 802 supplied by the single tanker car 804 to make up for evaporative losses in the various modified flat cars 802 .
[0103] Further, in some embodiments, antitheft measures (not shown) are emplaced about the modified flat car 802 so that at night, theft is deterred.
[0104] Refer now to FIG. 9 , which is a rather attractively packaged implementation 900 of the invention, suitable for patio, sun deck, indoor, or low cost applications. Here, a circular table 902 supported by three or more legs 904 , in turn supports a hydroponic planter 906 whereupon one or more plants 908 may be grown. A lower platform 910 attaches to at least some of the legs 904 . The lower platform 910 in turn supports the sealed nutrient container 300 previously described in FIG. 3 . The lower platform 910 also may support the air pump 912 and timer/controller 914 . Power may be at lowest cost (if connected to an electrical grid) connected 916 to residential AC power.
[0105] Here, the air pump 912 is activated by the timer/controller 914 , and powered by the AC power connection 916 (or other suitable power source as described above). The air pump 912 pressurizes the sealed nutrient container 300 through the air coupling 918 . Once pressurized, the sealed nutrient container flows nutrient fluid 920 through fluid coupling 922 , through the circular table 902 into a sealed connection 924 in the base of the hydroponic planter 906 . The sealed connection 924 is in turn covered by an inverted strainer 926 or other mesh (not shown) so as to prevent the clogging of the fluid coupling 922 by hydroponic growing substrate (not shown) that allows plant 908 roots to mechanically attach.
[0106] Operation is similar to previous descriptions above, with nutrient fluid 920 periodically being pumped by air pump 912 to the hydroponic planter 906 , additional air is pumped by the air pump 912 to oxygenate the roots, and the nutrient fluid flows back to the sealed nutrient container 300 via gravity induced drain-back.
[0107] Should the plant 908 be of a carnivorous species, additional food sources may be directly supplied to the plant in addition to the nutrient fluid 920 .
[0108] Refer now to FIGS. 10A through 10D , which are various methods of oxygenating the nutrient fluid in the sealed nutrient container previously described in FIG. 3 .
[0109] FIG. 10A shows an apparatus 1000 where the nutrient fluid is directly oxygenated by the air coupling. Here, the air coupling 1002 passes through to a bubbler 1004 , which, when operational, produces air bubbles 1006 , thereby aerating the nutrient fluid 1008 in the sealed nutrient container 1010 .
[0110] FIG. 10B shows an apparatus 1012 where the nutrient fluid is directly oxygenated by the air coupling throughout the length of the nutrient coupling. Here, the air coupling 1014 passes through to a bubbler 1016 , which, when operational, produces air bubbles 1018 that are captured by an inverted funnel 1020 , which funnels the air bubbles 1018 throughout the length of the fluid coupling 1022 , thereby aerating the nutrient fluid 1024 as it passes out of the sealed nutrient container 1026 to a hydroponic planter.
[0111] FIG. 10C shows an apparatus 1028 where the nutrient fluid is directly oxygenated by the air coupling throughout the length of the nutrient coupling. Here, the air coupling 1030 passes through to a bubbler 1032 , which, when operational, produces air bubbles 1034 that are captured by an enlarged fluid coupling 1036 , which transports the air bubbles 1034 throughout the length of the fluid coupling 1036 , thereby aerating the nutrient fluid 1038 as it passes out of the sealed nutrient container 1040 to a hydroponic planter.
[0112] FIG. 10D shows an apparatus 1042 where the nutrient fluid is directly oxygenated by the air coupling throughout the length of the nutrient coupling. Here, the air coupling 1044 passes through to a bubbler 1046 , which, when operational, produces air bubbles 1048 that are captured by an enlarged fluid coupling 1050 , which transports the air bubbles 1048 throughout the length of the fluid coupling 1050 , thereby aerating the nutrient fluid 1052 as it passes out of the sealed nutrient container 1054 to a hydroponic planter.
[0113] 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.” | A hydroponic growing system utilizes a single air pump to pressurize a sealed nutrient container, where a water-based nutrient fluid is initially forced up a nutrient coupling to a hydroponic planter growing bed. After the nutrient fluid from the sealed nutrient container falls below an input of the nutrient coupling, air from the air pump continues to bubble up through the fluid coupling, thereby oxygenating both the nutrient fluid and the more highly elevated hydroponic planter growing bed. After a controlled frequency and duration of air pump activation, the air pump is deactivated, whereupon the nutrient fluid drains back to the lower elevation sealed nutrient container by gravity. A small orifice acts to depressurize the otherwise sealed nutrient container, allowing the return of the nutrient fluid. The extremely modest energy requirements of the system easily allow off-grid operation using photovoltaic cells charging rechargeable batteries that power the system. | 8 |
This application is a divisional of application Ser. No. 07/974,694, filed Nov. 12, 1992 now U.S. Pat. 5,368,828
FIELD OF THE INVENTION
This invention relates to methods and apparatus for sterilizing cartons prior to filling, and more particularly to increasing the shelf life of food products in sealed paperboard cartons.
BACKGROUND OF THE INVENTION
Paperboard cartons are commonly used for packaging pasteurized and ultrapasteurized milk and juice products. Such products are commonly packaged in gable top cartons which are preformed with a closed bottom before being filled. Typically, the cartons are advanced through a filling machine on a conveyor. Before the cartons are filled, a hydrogen peroxide solution is sprayed into the interior of the carton to kill the bacteria that causes spoilage of the milk. Safety precautions must be used to prevent hydrogen peroxide from causing injury to the workers. Regulations of the Occupational Safety and Health Administration limit the amount of hydrogen peroxide permitted in the air where workers are present.
After the hydrogen peroxide solution is sprayed into the carton, it is necessary to dry the interior of the carton before the carton can be filled with milk or other food product. The hydrogen peroxide solution is removed from the interior of the carton in conventional filling machines by applying heated air to the interior of the carton. The conveyor that supports the cartons in the machine stops for a predetermined time interval to permit operations, such as filling, closing and sealing, to be performed on the carton in sequence. If an operation requires more time than the predetermined time interval, then it is necessary to increase the time interval, or provide additional stations where the operation is repeated one or more times. The manner of blowing heated air into the carton by conventional machines is insufficient to fully remove the hydrogen peroxide from the interior of the carton at one station, and it is necessary to provide several additional drying stations before the cartons can be filled with milk. The need for multiple drying stations in these prior packaging machines not only adds to the expense of the machines, but also limits the production rate of the machines.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of this invention to provide an improved method and apparatus for the sterilization of the interior of cartons with hydrogen peroxide solutions.
It is a further object of this invention to reduce the time required and the heat load for carrying out the sterilization of the interior of cartons.
Another object is to provide a hydrogen peroxide system that protects workers from the harmful effects of exposure to the chemical vapors.
These objects are accomplished in accordance with a preferred embodiment of the invention by a carton sterilization system that has two stations. In the first station, an atomized spray of hydrogen peroxide is applied to the interior surfaces of a preformed carton. At the second station, a mandrel is inserted into the carton. The mandrel has a plurality of nozzles which direct heated, sterile air against the interior surface of the carton. The flow of heated air and the pattern of the nozzles cause the hydrogen peroxide vapors and liquid droplets to be removed efficiently from the interior of the carton without substantially increasing the process time, and without requiring additional applications of heated air.
The mandrel reciprocates into and out of the carton and has a pattern of nozzle openings that provides a substantially uniform pattern of distribution of the heated air over the interior surface of the carton. Heating the hydrogen peroxide in this manner increases the effectiveness of the hydrogen peroxide, and causes the hydrogen peroxide vapor and droplets to be removed efficiently.
Preferably, the first and second stations are enclosed in a chamber to protect workers from the hydrogen peroxide vapor.
DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the invention is illustrated in the accompanying drawings, in which
FIG. 1 is a schematic view of carton filling apparatus incorporating the carton sterilization system of this invention;
FIG. 2 is a side elevational view of the carton sterilization apparatus;
FIG. 3 is an end elevational view of the carton filling apparatus;
FIG. 4 is a top plan view of the carton filling apparatus;
FIG. 5 is an isometric view of the dryer mandrels;
FIG. 6 is a side elevational view of one of the dryer mandrels;
FIG. 7 is a cross-sectional view of the dryer mandrel along the line 7--7 in FIG. 6;
FIG. 8 is a bottom plan view of the mandrel; and
FIG. 9 is a cross-sectional view of the mandrel along the line 9--9 in FIG. 8.
DETAILED DESCRIPTION
Referring to FIG. 1, the apparatus and process of this invention have been applied to a conventional automatic filling machine, such as the type disclosed in U.S. Patent No. 4,448,008 for use in filling preformed cartons with liquid food products such as milk or juice. These conventional automatic filling machines are supplied with preformed blanks. The machine opens the blanks to form a tube, seals the bottom of the tube to form a carton with an open top, and places the carton on a conveyer. As the carton advances through the machine, it is filled with liquid food product, and then the top is closed and sealed. The filled carton is then conveyed out of the machine. The carton sterilization system of this invention is interposed between the formation of the carton and the filling of the carton.
Referring to FIG. 1, the carton formation apparatus 2 places cartons 4 in sequence on a rail 7. In accordance with conventional practice, a conveyer 6 advances the cartons intermittently two stations at a time, which allows two cartons to be filled simultaneously. The conveyor has a dwell time that allows sufficient time for carrying out the slowest operation in the machine. The system of this invention could be adapted to machines in which the cartons advance one station at a time or more then two stations at a time. The filling stations 8 are shown in FIG. 1. At the filling station, liquid food product is dispensed into the open top of the cartons by conventional dispensing equipment. Two cartons are filled simultaneously and then advance to the closing and sealing stations (not shown).
The sterilization system of this invention is interposed between the carton supply portion of the conveyer 6 and the filling station 8. The sterilization system includes a hydrogen peroxide spray system 10 and a heated air dryer station 12.
At the hydrogen peroxide spray station 10, two sprayers 14 are positioned over the cartons 4 to direct an atomized mist or spray onto the interior surfaces of the container. A solution of hydrogen peroxide is supplied through suitable conduits 16 to the sprayers 14 and compressed air is supplied to the sprayers 14 to cause atomization of the hydrogen peroxide solution. The solution has a concentration of 0.1-15 percent hydrogen peroxide, and the flow rate through each nozzle is between 0.1 and 1.0 liters per hour. Preferably, the spray is in a full cone-shaped pattern to provide a uniform coating of the hydrogen peroxide solution on the interior side walls and bottom of the carton.
The hydrogen peroxide activated by heat, must be removed from the interior of the cartons 4 before they are filled with the liquid product, and this is done at the dryer station 12. The dryer station includes an insulated housing 18. A mounting plate 20 which is secured to the bottom of the housing 18 supports a pair of mandrels 22. As shown in FIGS. 5-9, the mandrels 22 are hollow and have a tubular body 24 which is secured to the plate 20. The lower end of the tubular body 24 is covered by a nozzle plate 26. The tubular body also has a pair of guides 28 extending along opposite sides for engaging the interior walls of a carton to prevent the walls from collapsing against the side of the tubular body 24. As shown in FIG. 7, the side walls 30 of the tubular body 24 slope inwardly toward the longitudinal center line. The front and back walls 32, 34 are substantially flat at the lower end of the mandrel 22, while the portion of the front and back walls that is adjacent the plate 20 slopes inwardly in the same manner as the side walls 30. The plate 20 has an opening 36 that is aligned with the interior of the tubular body 24.
The nozzle plate 26 has a central nozzle 38 and corner nozzles 40 as shown in FIGS. 7-9. In FIG. 6, a representative bottom-sealed carton 4 is shown as positioned on the conveyer 6 to show the relationship between the nozzle plate 26 and the interior of the carton 4 when the mandrel is lowered into the carton.
Referring to FIGS. 2-4, the mandrels 22 are attached to the housing 18 by means of the plate 20. Air is supplied to the housing 18 through a flexible conduit 42. Air under pressure is supplied to the conduit 42 by an air blower 44 or other suitable means. A pipe connector 46 provides a rigid mounting for the housing 18 on a mounting bracket 48. A heater unit 61 is mounted on the bracket 48 between the conduit 42 and the connector 46. The heater unit 61 may be an electrical resistance type, or any other suitable type for heating the air as it flows through the unit. The bracket 48 is mounted on a vertical shaft 50 which is mounted for reciprocating motion in a vertical sleeve bearing unit 52. A drive mechanism 60, which preferably is of the crank and link arm type, imparts vertical reciprocating motion to the shaft 50 in timed relation to the operation of the other components. Coordination of the conveyor 6 and the drive mechanism 60 is controlled by the machine drive 62. The mounting bracket 48 is shown near its uppermost position in FIGS. 2 and 3. Air from the conduit 42 is supplied to the interior of the mandrels 22 by a pair of pipes 54. Heating elements or other suitable means are provided in the heater unit 61 to transfer heat to the air flowing through the pipes 54. The maximum temperature of the air should be less than the temperature that will cause damage to the carton material. To avoid overheating carton material which typically has a polyethylene coating, the temperature of the air flowing from the nozzles should be about 715° F. for the smallest containers and about 1050° F. for the tallest containers. The flow rate of air through each mandrel 22 is preferably 10-15 cfm.
Since the apparatus of this invention is intended to be used with cartons of different heights, it is necessary to adjust the operating conditions depending on which size of carton is being processed. The quantity of hydrogen peroxide spray for each carton should be proportioned to the surface area of the carton side walls and bottom. The sprayers 14 have conventional controls which adjust the flow rate of the solution and the air pressure to achieve the desired degree of coating of the carton surfaces. The temperature of the air and the flow rate of the heated air used for drying the cartons must also be adjusted in relation to the size of the cartons. The stroke of the mandrels is the same for all sizes of cartons, preferably 6.3 inches, and for short cartons, the ratio of penetration of the mandrel 22 to the height of the carton is more than for taller cartons. As shown in FIG. 3, the position of the rail 7 is adjustable so that the top of the carton will be positioned at the proper height for receiving the mandrel 22 and for being filled and sealed, regardless of which size carton is being filled and sealed.
As shown in FIG. 1, the hydrogen peroxide sterilization station 10 and the dryer station 12 are preferably enclosed within a housing 56. The housing 56 has openings at opposite ends to allow the cartons to enter and leave the housing. The air flow through the exhaust line 58 should be greater than the air flow into the enclosure at each end where the cartons enter and leave and from the nozzles in the nozzle plate 26, so that hydrogen peroxide vapors do not escape from the enclosure but are directed through the exhaust line to be collected and treated before being returned to the atmosphere.
In operation, cartons 4 are formed and placed on the rail. The conveyer 6 advances intermittently a distance that corresponds to the spacing between two cartons, so that two cartons are treated simultaneously at each station. The dwell time of the conveyor is selected to be long enough to carry out the necessary operation at each station, and since a continuous conveyor is used, the longest required dwell time controls the timing of the conveyor. The cartons then advance to the sterilization station 10. A spray nozzle sprays hydrogen peroxide solution into the interior of each carton to form a coating of the hydrogen peroxide solution on the interior surface of the carton. The cartons next advance to the dryer station 12. The mandrels 22 are initially raised to the position shown in full lines in FIG. 2. The blower 44 is operated so that a stream of air is flowing through the conduit 42 and through the pipes 54 to the interior of the mandrels 22. By operating the mechanism 60, the bracket 48 lowers the mandrels 22 from the position shown in FIG. 3 into the interior of the cartons on the conveyer until the mandrels reach the position shown in FIG. 6 relative to the support plate 7 of the conveyer 6. Air from the conduit 42 is heated as it passes through the heater unit 61. The hot air flows out through the nozzles 38 and 40 in the nozzle plate 26 and then upwardly along the guides 28 until it flows out through the top of the carton 4. The stroke of the mandrels 22 is the same for small cartons of limited height as it is for taller cartons, since an important feature of the invention is that this machine is easily converted for use with shorter cartons without having to adjust or change the stroke of the mandrels 22. After a predetermined period of time, the mandrels 22 are raised and the cartons then advance to the filling station 8 (FIG. 1).
AS an example of the conditions that are appropriate for carrying out the process of this invention, the hydrogen peroxide solution should have a concentration of 0.1 to 15% of hydrogen peroxide, and preferably a concentration of 10%. The temperature of the heated air as it flows out of the nozzle plate is preferably between 1050° and 1100° F. for a 245 mm tall carton. The total flow rate is preferably 10 to 15 cu. ft. per minute. The vertical movement of the mandrels 22 is about 6.3 inches. Using these conditions, a satisfactory reduction of B subtilis should be achieved.
By inserting the mandrels in the interior of the cartons and directing the high temperature air stream against the interior surfaces of the carton, and particularly against the bottom corners of the carton, residual quantities of hydrogen peroxide are substantially eliminated from the interior of the carton in a single step, so that the cartons can be filled immediately after passing through the dryer station 12. For taller cartons, heated air flows from the nozzles upwardly along the space between the walls 30, 32, 34 of the mandrel 22 and interior side wall of the carton to remove the hydrogen peroxide effectively. No additional drying treatment is required.
While this invention has been illustrated and described in accordance with the preferred embodiment, it is recognized that variations and changes may be made therein without departing from the invention as set forth in the claims. | A method and apparatus for sterilizing preformed cartons prior to filling is disclosed. The interior of the cartons are first sprayed with a solution of hydrogen peroxide. The cartons are then treated with heated air to remove the hydrogen peroxide. The heated air is applied by means of a hollow mandrel having nozzles at one end. The mandrel corresponds generally to the shape of the carton. When the mandrel is inserted in the carton, air is directed against the interior side walls and bottom of the carton, and is exhausted from the carton by flowing upwardly between the side walls of the mandrel and the side walls of the carton. | 1 |
RELATED APPLICATION
[0001] This patent application claims priority to Provisional Patent Application No. 60/632,435, entitled UNIVERSAL GAMING DEVICE, filed Nov. 30, 2004, which is copending, herein incorporated by reference in its entirety.
FIELD
[0002] The present invention relates broadly to computer systems supporting gambling operations. Specifically, the present invention relates to a secure computer system that supports gaming applications through various modules that are verified by a trusted source.
BACKGROUND
[0003] Gaming environments have become increasingly reliant on automated systems, such as hardware and software, to administer functions and processes that support the gaming environment. However, as these gaming environments involve the exchange of money, security of the underlying functions and processes has become a primary concern, and safeguards must be in place before operators of the gaming environment are licensed by their respective gaming authorities.
[0004] Because the gaming environments now are dispersed over wide geographic areas and involve hardware and software that communicates with remotely located sites, there is an inherent opportunity for security breaches to occur within the communication path between sites, thus providing cheats with a way to control game outcome and reap illegal profits. This problem is especially difficult to solve because the gaming environment often involves a chain of communication across multiple computers that together serve to support the gaming environment.
SUMMARY
[0005] The present invention solves the problems described above by authenticating key equipment and software in a distributed gaming environment through the use of embedded, digital keys and digital certificates in a private key infrastructure (PKI). By issuing a key from a trusted source, referred to herein as the root server, authentication is performed in a serial manner throughout the operational chain of hardware and/or software modules that collectively serve to support the gaming environment. Beginning with the root certificate authority server, each module in the operational chain authenticates itself to another module that relies on that module's authenticity. By authenticating the chain of modules in a serial manner from beginning to end, security of the gaming environment is ensured.
[0006] In one aspect, the present invention provides a secure, server-based gambling system. The system includes a root digital certificate created by a trusted source that indicates authenticity of a server platform for a networked gambling system by authenticating software and data residing on the server platform. In an embodiment, the root digital certificate comprises a public key and a private key. In an embodiment, the public key and private key are stored together in a token. Depending on the embodiment, the token can be a magnetic storage device, an optical storage device, and can be configured to be a read-only storage device. In an embodiment, the root certificate authority utilizes a Federal Information Processing Standards (FIPS) Level 3 Certified Hardware Security Module configured to generate a public key and a private key.
[0007] The system also includes a gaming certificate authority server (gaming CA) and a gaming registration authority server (gaming RA). In an embodiment, a firewall separates the gaming certificate authority from the gaming registration authority. The gaming CA is configured to issue digital certificates to the gaming RA. The gaming RA is configured to receive certificate requests from clients, authenticate the requesting clients, and transmit certificate requests made by the authenticated clients to the gaming CA. The gaming RA is configured to receive digital certificates from the gaming CA and transmit them to authenticated clients. In an embodiment, the client includes a user certificate authority, which can include a signing station. The client utilizes a process that offers a user certificate as authentication of a user. In an embodiment, functionality of the gaming RA is incorporated into the gaming CA.
[0008] In another aspect, the present invention provides a method of operating a server-based gambling system, comprising the acts of issuing a root digital certificate from a trusted source to a gaming certificate server; authenticating a gaming CA by examining a private key and public key associated with the gaming CA and generating a second digital certificate indicating that the gaming CA is authentic, the second digital certificate containing data indicating the root digital certificate; the gaming CA authenticating a user certificate authority server that is located at a user site and generating a third digital certificate, the third user certificate containing data indicating the second digital certificate; and transmitting and receiving data sets and key values to and from clients authenticated by the user certificate authority server at the user site.
[0009] In an embodiment, after a unique public and private key pair is generated, the public key is registered with a gaming RA with a request for a certificate that certifies that the public key belongs to the user. The root certificate authority (root CA) server is used to create the gaming CA. Like the Gaming CA, the root CA has a public and private key pair with the private key residing on the root token and the public key residing on the certificate request machine. The public key is used by root certificate authority when issuing, managing and revoking certificates to the gaming CA.
[0010] In an embodiment, a hardware security module (HSM) is included in the present invention. When necessary, a token is read by the HSM. In an embodiment, the HSM is an electronic card reader that is physically wired to the certificate request machine and later transferred to the signing station (after creation of the root CA and gaming CA). When the system is looking for the root private key to create the gaming CA, it is directed to the HSM. If the token is in the reader and the reader has been unlocked using PED keys and PINs, the system has access to the root private key and can generate a gaming certificate. If the token is not physically present in the HSM or has not been physically unlocked using the PED keys and PINs, the system cannot find the root private key and will not function to create the gaming CA.
[0011] When the security token is inserted into the HSM, it is still not functional until the HSM is physically unlocked. In an embodiment, there are three individually-issued security officer keys that are required to unlock the HSM and allow the root private key to function. These three keys are PED keys, not digital keys created by the software, but physical keys requiring PINs (4-16 digits) to unlock the HSM which stores the root private key.
[0012] The root CA is at the top of the PKI hierarchy of the present invention and is the most critical entity within the system of the present invention. In an embodiment, to minimize the risk of a security compromise, the root CA only issues, manages and revokes certificates to the gaming CA. This self-signed root certificate is embedded in software and disk-on-modules and authenticates software on various servers and devices. There is only one root CA, and, if compromised, everything within the PKI structure is compromised. Therefore, protecting the integrity of the root CA is imperative, as all applications in the system of the present invention look for authentication when started. The root CA uses the HSM to generate a digital root private and public key pair. The private key is stored in the HSM tamper proof token at all times. It is generated using its own random number generator. The public key is downloaded from a local web interface and, in an embodiment, stored on a certificate request machine. The root CA requires the root private key to be used to generate a root certificate. Without the root private key, a certificate cannot be created, so protecting the root private key is essential. If the root private key is compromised, it can generate a genuine root certificate that can be ultimately embedded in an unauthorized version of software. Once a false gaming certificate is created, a false application can be created and the system is compromised. The root private key on the HSM token is used locally for the authentication process while a second token is stored off-site in a secure location.
[0013] The next item in the PKI hierarchy is the gaming CA. The gaming CA is subordinate to the root CA and is created using the root CA private key on the HSM token. The gaming CA handles the day-to-day operations of issuing, managing and revoking certificates to the individual bingo operations and creates digital authentication for executables. The gaming CA must have a valid certificate from the root CA for its private and public key pairs to function. The private key of the gaming CA is stored in a separate token from the root CA token. As the final step for delivering software to the field, the gaming CA will sign the software as authentic and create a digital authentication of the executables using its own private key whose corresponding public key is managed by the root CA via digital certificate. When the software is installed in a gaming operation, the system will verify the digital authentication of the executables with the public key of the attached gaming CA certificate. Before authentication however, the system alsalso validates the gaming CA certificate with the embedded root certificate via certificate chaining. As with the root CA, the gaming CA also creates a public and private key pair. In an embodiment, the public key is contained in a certificate file that is transferred to the signing station machine from the certificate request machine. The gaming CA's private key resides on a gaming CA (HSM) token, which is a separate token from that storing the root CA's private key.
[0014] In an embodiment, the generation of a gaming CA is a two step process. The first step involves generating a request from the signing station. The second is processing a request from the certificate request machine.
[0015] It is important to understand that there is a physical location where the authentication process takes place. Using the simple online shopping example, authentication activity takes place at the source or local PC. The local PC and peripheral connections make up the PKI perimeter. In an embodiment, the PKI perimeter is the signing station. It is important to understand the PKI perimeter as that is the area that is vulnerable to intrusion and must be secured.
[0016] The signing station resides in the central office and is used to sign system, device, and peripheral programs and data sets. In an embodiment, signing occurs by encryption of a hash value created from the program and data sets. Encryption is performed using the gaming CA's private key. The encrypted hash value and gaming certificate are attached to the end of the program or main data set. In an embodiment, the program or data set is authenticated by the secure boot loader. However, in alternative embodiments, authentication can be performed by other resources within a server or device. Likewise, software and datasets are authenticated before they are installed and/or loaded.
[0017] The certification authority server resides on the certificate request machine and is used to revoke a certificate, download a certificate revocation list (CRL), and view revoked certificates, issued certificates, pending certificate requests and failed certificates.
[0018] In embodiments of the present invention, a hardware device referred to herein as the boot loader replaces the conventional hard disk drive on server machines in the PKI infrastructure as the boot device. Once installed, this device blocks users from accessing specific commands. By blocking these specific commands, the user is prevented from making unauthorized changes to the system.
[0019] Other features and advantages of the present invention will become apparent from the following detailed description, when considered in conjunction with the drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 illustrates components of the present invention maintained at a central office.
[0021] FIG. 2 illustrates components of the present invention maintained at a gaming site.
DETAILED DESCRIPTION
[0022] Digital certificates are used throughout embodiments of the present invention and in different forms. For example, a data set signed digital certificate is issued by the gaming certificate authority based signing station. The certificate includes a serial number, expiration date, encrypted data set hash, encrypted digital certificate hash, and the gaming certificate authority's digital public key. Examples of data sets include game executables, game graphics, game setup programs, game configuration data, and gambling machine peripheral programs such as bill acceptor executables.
[0023] A user digital certificate is an electronic identification card that establishes a server, service, gambling device, peripheral such as a bill acceptor, or system user such as a technician credentials for identification as a legitimate user for secure transactions. The certificate contains information such as the gambling device name or ID, bill acceptor name or ID, user name or ID, a serial number, expiration date, a copy of the user's public key (used for encrypting messages and digital signatures), and the digital signature of the certificate-issuing authority. Digital certificates in accordance with embodiments of the present invention comply with the X.509 standard. These certificates contain information such as the version number, serial number, validity date, and subject's public key. The certificate contains both the certificate information and the digital signature of the signing certificate authority (signing CA). The signature is the signing CA's private key encrypted hashed value of the certification information. Digital certificates can be kept in registries so that authenticating machine can look up other machine's public keys.
[0024] There are several preferred configurations of the present invention. Directing attention to FIGS. 1 and 2 , central office 10 incorporates gaming CA 12 and gaming RA 14 separated by communication firewall 16 . In this embodiment, gaming CA 12 is in communication with an offsite root CA. The root CA is considered a trusted source of verification keys, which are stored on token 18 that is transported to central office 10 by conventional delivery methods such as hand delivery rather than communicated over a communication network. Token 18 is a portable storage device capable of storing data, and can be magnetic storage, optical storage, and the like. Gaming RA 14 is in communication with user CAs (not shown) which can be located at site 15 at managed gaming environments such as casinos, bingo halls, and the like. Gaming RA 14 communicates with one or more user CA 17 by public network 20 , such as Internet. While FIG. 1 illustrates gaming CA 12 and gaming RA 14 as separate servers separated by a firewall, in an alternative embodiment, gaming CA 12 can incorporate the functionality of gaming RA 14 , and thus firewall 16 would simply separate gaming CA 12 from connection to public network 20 .
[0025] A site secret is a value that is securely exchanged between the user CA and gaming RA 14 by encrypting it using the user CA's public key extracted from a valid certificate request from a site. In central office 10 , the site secrets are stored in secure database 22 for the security server (not shown) to generate and distribute passwords to authorized employees. The issued certificate may include details such as the password change frequency and expiration date. The site secret is a unique 3DES key generated by the gaming CA to authenticate the contents of unprotected hard disk space during the boot-up process by decrypting the 3DES or equivalent key encrypted contents on some implementations. The site secret is stored 3DES encrypted or equivalent by the boot password. The site secret is also used to generate one-time passwords for technicians, accountants, and customer support for accessing the system via a network.
[0026] When the user CA receives the new site secret from gaming CA 12 , it is encrypted using the user CA's public key so that only the user CA having the corresponding private key may decrypt the site secret. As other clients request certificates from the user CA, the site secret is passed to the client, encrypted using the client's public key. Only the client possessing the corresponding private key may decrypt the site secret. As referred to herein, a client can be any of: a device, a process that communicates with another device, or a user of the device or process.
[0027] User CA and client private keys are encrypted using an obfuscated symmetrical key encryption algorithm. User private keys are encrypted using user passwords. The device or peripheral validates gaming CA 12 's certificate using the device or peripheral's embedded root certificate. The gaming certificate includes a root public key encrypted hash of the gaming certificate's public key. The validation is accomplished by running a hash on gaming CA 12 's public key (and optionally other certificate fields), encrypting the hash using the embedded root certificate, then comparing the derived gaming public key encrypted hash value with the one contained in the gaming certificate. If the values match, the software or dataset is next validated. A hash is run on the software or dataset. The hash result is then encrypted using the gaming certificate's public key. The software or dataset's encrypted hash value is then compared with the encrypted hash value stored by the signing station at the end of the software or dataset. If the values match, the software or dataset is allowed to be installed or loaded. If the values don't match, the software or dataset is not allowed to be installed or loaded.
[0028] Embodiments of the present invention utilize the secure socket layer (SSL) protocol to manage the security of a message transmission on public network 20 . SSL uses a layer between the application and transport control protocol (TCP) layers. SSL uses the public-and-private key encryption system and digital certificates from both parties for authentication and then exchanges session keys for subsequent bulk encryption.
[0029] The session secret is a set of random numbers generated at the beginning of a gaming session. The session secret is used to encrypt RF messages for wireless devices or SSL using the symmetric key cryptography such as 3DES.
[0030] The system of the present invention can be classified into two types of components, gaming components (GCs) and site management components (SMCs). Only secured, authenticated devices are allowed in the gaming component.
[0031] Example devices in the gaming component are various servers, a caller/verifier, point of sales (POS) systems, self-serve kiosks, fixed-base player units, and portable player units.
[0032] Gambling server 24 authenticates all device certificates as either class A or class B based upon the device certificates issued by site CA 26 . Class A certificates identify GC devices and class B certificates identify SMC devices. Based upon the certificates, the server establishes SSL connections with the clients and handles appropriate messaging.
[0033] Gambling server 24 processes messages that update critical gambling data if and only if the messages come from devices with a class A certificate. No device is allowed to establish SSL connections with gambling server 24 without a valid certificate issued by the user CA.
[0034] Gaming components manage the actual game play. On some systems, game play begins with an operator logging into point of sale (POS) system 28 . Products sold include electronic bingo cards, paper bingo cards, and entertainment services.
[0035] POS system 28 records all game-critical sales data such as sold items, sold bingo card numbers, session numbers, starting values, pack numbers, and VIP player information in the gaming component database 30 . Communication between gaming component server 32 or a service and device occur via an SSL connection. A client never writes to a GC database component directly. POS system 28 may record data that is not game-critical such as unsold paper card information and site employee information to database 29 via an SSL connection which has been negotiated with a secured site certificate. On other systems, game play begins when users login or insert cash into a player terminal. Game play and other transactions are stored in the GC database 30 .
[0036] Site management components include site management software and a site database server(s) for sales analysis, inventory control, player management, and site employee management. The site management system does not affect the actual critical gaming integrity. Site management software can read and write only to the site database server's database that contains non-game-critical data such as unsold card information, player information, site employee information, and the like.
[0037] All GC floor devices implement a secure boot loader and digital authentication for program and data set authentication. The secure boot loader ensures that only authentic executables are loaded into memory during the boot process. GC servers are usually located in a locked room. Servers in this environment are usually under the control of an IT staff. Programs that are allowed to run on the GC server may be authenticated by a boot loader or optionally a white list file. The white list file contains programs that may run on the server as well as their hash value. A hash function is run against the program, then matched against its white list hash value before the program is executed. Sensitive gaming data is only accessed by applications running on the server. Non-gaming (GMC) data may be accessed directly by client applications. Client devices must sign critical designated records with their private keys.
[0038] The database signature validator is an application on the gambling server that reads through each secured database file and verifies the records using the site public key. If any digital signature of a record does not validate, it flags an error to a technician.
[0039] The security server 40 at central office 10 and the security server 42 at site 15 are available via the secured intranet or internet site. Internal applications request current central and remote site passwords from the security server for specific sites. Field technicians log into the security server to request current network and operating field technician account logins/passwords, or passwords for a specific site.
[0040] All such requests are logged to provide an audit trail of who had access to which site for which time periods. Access to specific sites is controlled and managed by region and authorization. Notices are proactively sent and logged when technicians request passwords that provide access to critical functions.
[0041] SiteCom (not shown) is an application that allows an authorized employee to connect to a central or remote gambling site. When the application connects, it prompts the user for a login name and password. The technician obtains the appropriate site login and password by logging into gambling server 44 at central office 10 or remote secure gambling server 24 at site 15 with his own assigned login name and password. This process may be automated.
[0042] After the technician receives the site login name and password from the security service, SiteCom negotiates the site login name and password with gambling site to establish a connection. Based upon the site loginlpassword, the server provides appropriate access to its system resources.
[0043] Passwords for site IT accounts, local technician accounts, database accounts, etc., are based on an algorithm seeded by the site secret. These change on a regular, configurable basis. Access to these passwords are controlled and distributed by the corporate IT system.
[0044] For some implementations, networked client units are authenticated by periodically changing the client password on the server. The periodically changing of network passwords is based on the site secret, the date, the time, and the password generation frequency.
[0045] All devices require a certificate from user CA 17 for authentication. User CA 17 is the service or server that runs on the secure gambling server computer or network that issues, manages, and revokes certificates to all of its client machines within a gambling site.
[0046] CommManager 46 is a program that manages the SSL handshakes from clients. CommManager 46 verifies the (user CA issued) client certificates and exchanges the session key for all subsequent messages with the server. The client devices authenticates with a server or service via the certificate issued to user CA 17 by gaming CA 12 or user CA 17 itself.
[0047] Employee and player access are controlled via standard user name and password application level security. In an embodiment, an employee or player could be issued a digital certificate.
[0048] Secure boot loader 48 is trusted software that verifies the operating system and other executables within the system are authentic when the system boots. Secure boot loader 48 , combined in some cases with a custom BIOS, provide the system with a root of trust. For some implementations, secure boot loader 48 is the read-only disk-on-chip that contains an operating system and network operating system. For other implementations, secure boot loader 48 is the secured boot sector within the hard drive that is authenticated by the read-only BIOS.
[0049] For some systems, both operating and network operating systems are stored in a read-only disk-on-chip. The read-only disk-on-chip ensures that only authenticated operating systems are loaded when the system boots. The read-only disk-on-chip is considered the root of trust, and contains the root certificate along with the digital authentication application that authenticates all executables on the rewritable hard-disk within the system.
[0050] A client device may include a slot terminal with a BIOS, a read-only disk-on-chip, and a re-writable hard drive. In this embodiment, the secure boot loader is a read-only disk-on-chip that contains the operating system, network operating system, the root certificate, and authentication program. The read-only nature of the disk-on-chip ensures that its content is authentic, and provides the basis of the root of trust.
[0051] Secure boot loader 48 example relies on a standard personal computer BIOS. The standard BIOS is configured to boot only from secure boot loader 48 , and the rewritable hard drive is configured as a non-bootable slave drive. Machines with a secure boot loader are further secured with a combination of tamper resistant tape, security lock, and power off detection devices, so that only authorized technicians may have access to the internals of the machine.
[0052] The root certificate is stored in the read-only secure boot loader 48 . The authentication program within the boot loader uses the root certificate to verify the digital authentication of new software updates and the certificate(s) issued by gaming CA 12 .
[0053] To implement token 18 , a secure BIOS ROM may be used, such as the Phoenix “FirstBIOS ROM” is a tamper-proof ROM that stores the cold-boot code, a seed of trust, and a hard-coded hash value. It is a removable chip that may be secured with security tape so that a regulatory agent may remove the chip and verify its contents for a security audit at any time. The secured BIOS ROM hash-checks the intermediate bootable service areas and root certificate against the hard coded hash value stored in the secured BIOS ROM to verify its authenticity.
[0054] When a gaming server, device, or peripheral is equipped with a secured BIOS ROM, the BIOS holds the key to opening the host protected space. Once the machine is initialized and the host protected space created, only the BIOS can expose it.
[0055] The host protected area (HPA) is a protected area of the hard drive reserved for storage of critical data and applications in a container segregated from the rest of the hardware by an internal firewall. This protected storage area is accomplished through the use of an ATA command called SETMAX. Issuing a SETMAX command to the hard drive allows the drive to report to the rest of the system that its maximum storage address (reported max) is lower than its actual physical storage limit (native max).
[0056] In an embodiment, the host protected space contains an intermediate bootable service and root certificate, a private key encrypted secure boot loader, a gaming CA signed encrypted site secret, an encrypted site private key, and a gaming certificate.
[0057] The intermediate bootable service is responsible for validating the root certificate by verifying its expiration date and extracting the public key from the root certificate. It then verifies the digitally authenticated compressed secure loader using the gaming CA public key. The gaming CA's public key is extracted from the gaming CA's certificate that is also verified by the root certificate. The decrypted compressed (optional) secure loader is decompressed (optional) and loaded into RAM for execution.
[0058] The secure loader is a program that loads the operating system, SQL server, and gaming server(s) or service(s) into RAM from the unprotected hard drive space. The secure loader first searches for a gaming CA signed encrypted site secret, verifies the gaming CA's digital signature on the encrypted site secret, and optionally prompts the site manager to type in the boot password to decrypt the site secret. If the site manager types in the proper boot password for the encrypted site secret, the secure loader uses the decrypted site secret to decrypt the 3DES encrypted operating system, SQL server, and gaming server(s) and service(s) from the unprotected hard drive space. It then loads them into system RAM for their execution. The secure loader also has an embedded list of authentic executables and deletes any executables that are not part of the list of authentic executables from the unprotected hard drive space.
[0059] If the secure loader fails to find gaming CA 12 's signed encrypted site secret or if the user fails to submit the correct password after certain number of trials, the secure loader then looks for a private key encrypted installation executable within the unprotected hard drive space.
[0060] If the private key encrypted installation executable is successfully authenticated, the secure loader then executes the file, and generates a new user CA private/public key pair, and a certificate request for the newly generated user CA public key. The technician sends the certificate request to gaming RA 14 , which validates the certificate request and forwards the certificate request to gaming CA 12 .
[0061] In an embodiment, the unprotected area within the hard drive contains a private key encrypted installation executable, 3DES encrypted embedded operating system, 3DES encrypted SQL server, 3DES encrypted WIN Server, 3DES encrypted POS station, and a partitioned gaming data drive. The unprotected hard drive space is partitioned to store only gaming data and security log files to ensure continuous gaming even after accidental rebooting of the gaming system. The operating system ensures that no executables are stored in the partitioned gaming data drive and no executables are executed from the partitioned gaming data drive. The authenticity of the content of the partitioned gaming data drive is verified by the security loader during the boot up process by verifying that only certain files exist.
[0062] For a secure windows boot loader, the private key is encrypted in PKCS #5 format. The encrypted private key is stored in the host protected area. The executable uses the key to generate a certificate request for its newly generated public key.
[0063] The technician responsible for installing the software signs the certificate request using his private key. The certificate request is forwarded to the gaming RA for a secure Windows user CA boot loader. For other servers, services, devices, and peripherals, the certificate request is forwarded to user CA 17 .
[0064] Gaming RA 14 validates the certificate request by verifying the digital signature of the technician and forwards the request to gaming CA 12 . Gaming CA 12 issues a certificate for user CA 17 's public key. A certificate is forwarded to the technician, used to find the 3DES key used to encrypt the OS, SQL Server, etc installed at site 15 , and encrypt the 3DES key using the public key submitted for the gaming certificate. The encrypted 3DES key is then signed by gaming CA 12 's private key.
[0065] User CA 17 analogously performs the same steps for other certificate requests.
[0066] The technician downloads the user CA gaming certificate and encrypted 3DES Key to his computer over a public network, stores the files on a disk, and inserts the disk into the server's disk drive or equivalent. The private key encrypted installation executable copies the encrypted 3DES key, verifies gaming CA 12 's digital signature for the key for authentication, decrypts the encrypted key, and stores it in the host protected space as the site secret, by 3DES encrypting it using the same password used by the site manager for encrypting the site private key. The private key encrypted installation executable copies the gaming certificate for the site public key into the host protected area.
[0067] The boot password is a user-defined password that is used to encrypt the site secret and the Site Private Key for one implementation of the secure server based gambling system. Upon boot, the user must enter this password to start the boot sequence that uses the site secret and the site private key. Depending upon the jurisdiction, the process of entering a password may be automated.
[0068] In secured environments, all portable devices are authenticated. During a catalog, a program download or at the time of sale, the device provides its certificate to an installation station such as POS system 28 . POS system 28 validates the certificate through the user CA and informs the device of its status. If the certificate is rejected or the device does not have a certificate, then it communicates to POS system 28 that it requires a certificate and provides some visible indicator that it needs to be authenticated before it can be used. The portable gaming unit then waits for a message from POS system 28 . POS system 28 acknowledges when it is ready to validate the device. The device generates a public/private key pair and sends POS system 28 a certificate request. POS system 28 accumulates the various machine names and types and displays them for the technician to confirm. Once they are confirmed, POS system 28 requests certificates from the server for each device and sends the certificate to the device. The client then stores the certificate.
[0069] At the time of sale, POS system 28 wraps the session secret in the public key for the device. This prevents unauthorized devices on network 20 from decoding the session secret. The device can then use the session secret for receiving and sending broadcast messages.
[0070] While preferred embodiments of a method and apparatus for secure gaming support have been described and illustrated in detail, it is to be understood that numerous modifications can be made to embodiments of the present invention without departing from the spirit thereof. | A method and apparatus for authenticating equipment and software in a distributed gaming environment through the use of embedded, digital keys and digital certificates in a private key infrastructure (PKI) is disclosed. By issuing a key from a trusted root server, authentication is performed in a serial manner throughout the operational chain of hardware and/or software modules that collectively serve to support the gaming environment. Beginning with the root certificate authority server, each module in the operational chain authenticates itself to another module that relies on that module's authenticity. By authenticating the chain of modules in a serial manner from beginning to end, security of the gaming environment is ensured. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
The present application claims priority to U.S. Provisional Patent Application No. 60/648,637 filed Jan. 28, 2005. The entire contents of the above application is incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
This invention was supported, in whole or in part, by grant 1R21CA89673-01A1 from The National Institutes for Health. The Government has certain rights in the invention.
BACKGROUND OF THE INVENTION
There are numerous features in the human body in which medical imaging techniques can be used effectively to assist in the diagnosis and treatment of medical conditions. Various diseases or conditions involve calcified materials, structures or deposits within the human body that are indicative of the medical condition of the patient. These can include features of the human skeleton, such as the spine, calcified deposits within the arterial system such as obstructions to blood flow in the coronary arteries, or microcrystalline deposits in breast tissue that can become cancerous. Breast cancer, for example, is one of the most frequently diagnosed malignancies and the second largest cause of cancer deaths in American females. Several improvements in diagnostic protocols have enhanced our ability for earlier detection of breast cancer, resulting in improvement of therapeutic outcome and an increased survival rate for breast cancer victims. Triple assessment is involved in identification of breast cancer. They are (1) clinical examination, (2) radiological assessment using mammography or ultrasound for example and, (3) pathological assessment using cytology or biopsy.
Although an impressive array of body-imaging techniques, such as x-ray imaging, x-ray computed tomography, magnetic resonance imaging, thermal infrared imaging (TIR), ultrasound, and radioisotope imaging are currently available to yield useful information, there are important limitations of safety, resolution, cost, and lack or limited specificity to key chemicals or structures necessary for functional body monitoring.
On the other hand, x-ray mammography, the current standard for monitoring breast cancer, has been shown to be effective in screening asymptomatic women to detect breast cancers. Abnormalities detected in mammography are classified as: Spiculated masses, Stellate lesions, Circumscribed masses, and microcalcification. Mammography is extremely useful in identifying pre-cancerous microcalcifications. Microcalcifications are found within the duct wall or lumen. Malignant microcalcifications are usually linear or branching whereas benign micro calcifications are rounded and punctuate.
This apparent positive benefit has resulted in a number of leading health care societies recommending that all women be screened using mammography on at least biennial basis. In order for mass screening to be cost effective, methods need to be developed to achieve it with high accuracy and speed. Moreover, as the microcalcifications are imbedded in dense soft tissue, the diagnosis of mammograms is subjective and solely depends on the interpretations of the radiologist of the mammogram. At times, even for qualified personnel, it is difficult to interpret screening mammograms in large numbers. So an appropriate use of imaging processing techniques to enhance the important features of mammograms improves the specificity and objectivity of clinical cancer diagnosis.
SUMMARY OF THE INVENTION
The present invention relates generally to the field of medical imaging in which digital images can be acquired and used in the diagnosis and/or treatment of medical conditions. A preferred embodiment of the invention uses image processing techniques to separate the phase information from the acquired digital image to provide an enhanced diagnostic image. A preferred embodiment of the invention is particularly useful for the identification and imaging of those features of the animal or human body which cause high spatial frequency features in the acquired image. Hard tissue structures such as bone or calcified or crystalline masses, lesions or cysts can cause such a high spatial frequency response making them suitable for phase component imaging.
Mammograms are now being acquired in digital format thereby allowing the use of digital image processing techniques such as the fast Fourier Transform, to enhance the identification of microcalcifications. A preferred embodiment of the present invention employs phase-only image reconstruction of digital mammogram that uses only high spatial frequency components, that show microcalcifications and contours of lesions and other masses of interest in a dark background. The phase-only information can be processed with averaged amplitude information to reconstruct the original digital image.
Preferred embodiment of the invention involve the phase imaging to provide images of obstructions within the arterial system, including the coronary arteries, to detection off kidney stones, of hairline fractures and other abnormalities within the skeletal system including the spinal column.
A preferred embodiment of the invention employs a digital imaging detector to acquire images from a region of interest. A patient support such as a table can be used to position a region of interest of the patient relative to an energy source such as an x-ray tube of a radiographic imaging system such as a computed tomography system or a mammography system. The imaging device provides image data to a data processor such as a computer having a memory, an image processor, a display and a user interface. A software program can be employed to provide phase-only image processing in accordance with the invention.
The foregoing and other features and advantages of the system and method for phase based digital imaging will be apparent from the following more particular description of preferred embodiments of the system and method as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A illustrates a method of forming an image of a region of interest of a patient in accordance with the preferred embodiment of the invention.
FIG. 1B illustrates a digital radiographic acquisition system in accordance with the present invention.
FIGS. 2A and 2B show an original image and a phase-only image with edge enhancement, respectively.
FIG. 3 shows a phase-only image of a phantom with simulated microcalcification.
FIGS. 4A and 4B show a contrast detail digital image of a phantom with embedded gold particles obtained using a full field digital mammography system and a phase-only image, respectively.
FIGS. 5A , 5 B and 5 C are an original mammogram, a phase-only image and a contrast adjusted phase-only image, respectively.
FIGS. 6A , 6 B and 6 C are an original mammogram, a phase-only image and a contrast adjusted phase-only image, respectively.
FIGS. 7A , 7 B and 7 C are an original mammogram, a phase-only image and a contrast adjusted phase-only image, respectively.
FIGS. 8A , 8 B and 8 C are an original mammogram, a phase-only image and a contrast adjusted phase-only image, respectively.
FIG. 9 illustrates a process sequence in accordance with a preferred embodiment of the invention.
FIGS. 10A-10E show and original mammogram and processed images in accordance with the invention.
FIGS. 11A-11E show an original mammogram and processed images in accordance with the invention.
FIGS. 12A-12C show an original mammogram and processed images in accordance with the invention.
FIGS. 13A-13C show an original mammogram and processed images in accordance with the invention.
FIGS. 14A-14C show an original mammogram and processed images in accordance with the invention.
FIGS. 15A-15C show an original mammogram and processed images in accordance with the invention.
FIGS. 16A-16J show an original mammogram and processed images in accordance with the invention.
FIG. 17 illustrates a process sequence in accordance with the preferred embodiment of the invention.
FIGS. 18A-18C show a reference image, auto correlation spot and peak value, respectively.
FIGS. 19A-19C show an image, auto correlating spot and cross correlation peak value, respectively.
FIG. 20 shows a phantom image with invisible micro calcification.
FIG. 21 shows a phantom image with invisible micro calcification.
FIG. 22 shows a phantom image with invisible microcalcification.
FIG. 23 shows a reference phantom image.
FIG. 24 shows a target image.
FIG. 25 shows a cross-correlation peak value.
FIG. 26 illustrates a process sequence in accordance with a preferred embodiment of the invention.
FIGS. 27A-27C show original images for spectral phase subtraction.
FIGS. 28A-28C show processed images from FIGS. 27A-27C .
FIGS. 29A-29C show contrast detail of phantom and processed images.
FIGS. 30A-30C show residual images based on FIGS. 20-22 .
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of the present invention is the phase characteristics of Fourier transform of medical images for computer aided diagnosis (CAD). We propose phase-only image reconstruction, original image reconstruction from phase-only information, phase-only correlations, spectral phase subtraction techniques for comprehensive CAD.
The method for phase-only image reconstruction is shown in FIG. 1A . Original digital image (digital mammogram, digital chest x-ray or in general any digital radiograph) is Fast Fourier Transformed using a programmed FFT sequence stored on a computer. The phase angle of the FFT spectrum is calculated. The phase of low spatial frequencies in the Fourier spectrum is zero or close to zero, while the phase of high spatial frequencies is in the neighborhood of ±π. From this phase angle, a phase-only function with unit amplitude transmittance is generated. The phase-only function is inverse Fourier transformed using another FFT operation to obtain a phase-only image. This phase-only image predominantly contains high spatial frequency components.
Microcalcifications are tiny regions of calcium in the breast. In digital mammograms these microcalcifications appear in small clusters of a few pixels with relatively high intensity compared with their neighboring pixels that belong to soft dense tissues in the breast. Given that the microcalcifications belong to high spatial frequency components of the Fourier spectrum of a digital mammogram, detection of microcalcifications is achieved by reconstructing the phase-only image. The low spatial frequency components (corresponding to the soft dense tissue) have zero phases and are suppressed in the phase-only image. Another important change seen on the mammogram is the presence of mass, which may occur with or without associated calcifications. A mass is any group of cells clustered together more densely than the surrounding tissue. The size, shape and margins (edges) of the mass help the radiologist in evaluating the likelihood of cancer. Since a mass differs in its gray-value with respect to the surrounding tissue in the mammogram, edges of the mass correspond to high spatial frequencies. The phase-only information of a mammogram with such masses shows the shape and edges of the mass.
Digital radiographs can be acquired using a system 10 such as that illustrated in FIG. 1B . This includes an x-ray source 12 , a table 14 on which a patient 15 lies, a detector system 16 for detecting x-ray radiation that is transmitted through the patient. The detector system is connected to a computer 18 having a memory 20 and an image processor 22 , a display 24 and a user interface 26 such as a keyboard. The computer 18 can be connected to a public access network such as the Internet, a local area network, or connected remotely to a remote network, server, computer workstation, or other databases. The detector system includes a digital detector such as a charge coupled device, a CMOS imaging detector, an amorphous silicon detector or other digital image detector employing a scintillator, or alternatively, it can be a detector that converts x-rays into electrical signals.
FIGS. 2A-2B , FIG. 3 and FIGS. 4A-4B show results of phase-only image reconstruction of digital phantoms. A digital phantom with invisible simulated microcalcifications which differ in brightness with respect to surrounding pixels are not visible while FIG. 3 shows a phase-only image reconstructed with only microcalcifications having good contrast. FIG. 4A is Contrast digital phantom with embedded tiny gold particles obtained from Full Field Digital mammography machine. FIG. 4B is the phase-only image of FIG. 4A . It clearly shows embedded small gold particles as tiny bright spots while little bigger size gold particles are shown with their shape and edges. FIG. 5A , FIG. 6A , FIG. 7A , and FIG. 8A show clinical digital mammograms and FIG. 5B , FIG. 6B , FIG. 7B , and FIG. 8B show the corresponding phase-only images. The microcalcifications are shown as bright spots in the dark background providing a many-fold increase in the contrast compared to the original image.
The advantage of this technique in detection of microcalcifications over conventional digital image processing techniques is, it doesn't depend on the density of soft tissue in the breast that appear as a background (DC components) in the mammogram. In other words the technique is self adaptive to the changes in the background as the phase of low spatial frequency is zero. On the other hand other image processing techniques that involve high pass and band pass filters, the filter size and threshold have to be adjusted depending on the type of background in the mammogram. The system of the present invention provides a phase only that image preserves the morphology and texture.
The phase-only image reconstruction can in general be applies to any digital radiographic image, digitized radiographic image, and Magnetic Resonance images (MRI) and Computed Tomography (CT) such as coronary calcifications in Cardiac CT images to extract and view essential features of the image hidden in the background of the image.
A method of reconstructing an original digital mammogram from its phase-only information is shown in FIG. 9 . It is common practice in mammography to obtain 4 different views of breast x-ray images, namely LCC, LMLO, RCC and RMLO. All of the images are Fourier transformed using an FFT sequence. The phase angle and spectual-magnitude of the Fourier spectrum for each image are extracted. The average magnitude is obtained by averaging the spectual magnitude over an ensemble of these images. The extracted phase-only information of each image is multiplied to this average magnitude. The resulting product of each image is then inverse Fourier transformed using the programmed FFT sequence to reconstruct the original image. These reconstructed original images preserve all the essential features of the respective original images including the morphology and texture.
FIG. 10A and FIG. 11A are original digital mammograms of the same patient but of different views; RMLO and LMLO respectively. FIG. 10B and FIG. 11B show the original image reconstructed from its phase-only information but with magnitude of FIGS. 11A and 10A degradation. It is important to note that the phase-only information is essential in reconstructing the original image as it preserves all the significant features of the image and not the spectral magnitude. FIG. 10C and FIG. 11C show the reconstructed original images of FIGS. 10A and 11A reconstructed from their respective phase-only information but with representative magnitude averaged over individual spectral magnitudes of FIGS. 10A and 11A . It is evident from these figures that FIGS. 10C and 11C resemble more closely to the original image than FIG. 10B and FIG. 11B . Thus the magnitude averaged over the large ensemble of similar images gives a nearly original image reconstruction. The sequence shown in FIG. 9 uses digital mammograms of LCC, LMLO, RMLO and RCC views of a patient to generate the average magnitude. FIG. 12A , FIG. 13A , FIG. 14A and FIG. 15A show the LCC, LMLO, RCC, RMLO views of the patient while FIG. 12C , FIG. 13C , FIG. 14C , and FIG. 15C show corresponding reconstructed original images from the average magnitude. FIG. 12B , FIG. 13B , FIG. 14B , and FIG. 15B show corresponding phase-only images.
Radiologists are often under tremendous pressure while giving decisions based on mammogram readings. The tiny microcalcifications hidden in the background of dense soft tissue are clearly visible in some mammograms, barely visible in some and not visible at all in some. This is mostly due to density of soft tissue in the breast which varies from person to person and with age. For example younger women have denser breast tissues providing a bright background in the mammogram. It can be very difficult to interpret mammograms in these cases. It would be helpful to the radiologist if a training tool is available which can be used to extract information about microcalcifications and other masses from a known mammogram case, add this information to different backgrounds provided by the other mammograms from the same or other patients and see whether the added information can be detected.
The preferred method of reconstructing an image using its phase-only information and spectral magnitudes of images is useful for training the radiologist in his decision making process. For example, the subtle microcalcifications and other important features such as cysts and masses can be extracted from a mammogram using phase only image reconstruction. Using the process sequence shown in FIG. 9 this phase only information can be multiplied with the magnitude extracted from any other mammogram and used to determine whether they are able to detect the features being added. The results are shown in FIG. 16 .
In clinical diagnosis, as well as in radiotherapy planning and evaluation, several images of one patient obtained using different imaging modalities or at different times, need to be compared. Although visual comparisons of available radiographic image with subsequent radiographic images are still standard practice as part of routine clinical evaluation, computerized analysis of these images has recently attracted the interest of both medical physicists and physicians alike. In this invention phase-only correlation and spectral phase subtraction techniques are used for tracking the development of useful information in digital radiographic images with respect to a selected time period.
Phase only correlation (POC) methods use the phase information of a reference image that is correlated with the phase information of an acquired image. Due to the absence of low spatial frequency components in the phase-only information the POC method produces a sharp correlation peak. The POC method is consequently preferred to the amplitude-only correlation and complex Fourier spectrum correlation techniques. This sharp correlation peak feature of POC technique is used for measuring translational, rotational and scale shifts in the medical images.
Phase-only information obtained from the phase of the Fourier transform suppresses the background due to soft dense breast tissue (low spatial frequency components) and predominantly contains information about essential features such a microcalcifications, shape and edges of masses and cysts (high spatial frequency components) in mammograms. The POC method can be used to correlate the phase-only information of a prior mammogram with phase-only information of a current mammogram.
The POC method shown in FIG. 17 can be used to calculate the discriminate ratio (percentage change in the said essential features of interest) between an image and its subsequent image (current) obtained at different time interval. Usually this time interval between the prior and the current image can be one month to a year depending on the seriousness of the case. When the image in FIG. 18A is used both as a reference and a target image in the sequence shown in FIG. 17 , the output correlation peak is called auto correlation peak as shown in FIG. 18C with the peak value=3.627. When the image in FIG. 18A is slightly distorted as shown in FIG. 19A and used as a target image in the process sequence, the maximum correlation peak value, called cross correlation peak, drops to 1.827 ( FIG. 19C ). The ratio of maximum of cross correlation peak value to the auto correlation peak, drops to 1.827. The ratio of maximum of cross correlation peak value to the auto correlation peak value is called discrimination ratio (DR). For this example the DR is 50.37%, and indicated the percent change in the high spatial frequency components of the target image with respect to the reference image.
For example, when the patient is normal, there may not be any clusters of microcalcifications present in the breast and the corresponding mammogram (say MAMO 1 ) will not show any sign of microcalcifications. When the patient obtains her next mammogram (say MAMO 2 ) after a year of two, and she developed some microcalcifications in the breast, which are a sign of a cancer at a preliminary stage. Certainly the radiologist may or may not be able to detect these microcalcifications in the mammogram, MAMO 2 . If the radiologist detects them, another mammogram (say MAMO 3 ) can be recommended after a month or so. By this time, she may have a more advanced stage of the cancer and develops not only a cluster of microcalcifications but also some masses like cysts in the breast. The radiologist after reading the mammogram, MAMO 3 , now recommends her for ultrasound scanning followed by biopsy. The phase of the Fourier spectrum of the mammogram in all three cases (MAMO 1 , MAMO 2 and MAMO 3 ) will be different and will often reflect only the changes in important features of the mammograms. However in the practical case, the random noise present in each mammogram may prevent reflection of actual changes in features of the two mammograms as random noise is also found in the high frequency components. This random noise is function of many parameters that can depend on the imaging system. Under preferred conditions, the amount of random noise in each mammogram may be more of less the same and cancel out when a comparison is drawn between these mammograms. Thus, when the high spatial frequencies due to subtle microcalcifications in MAMO 2 are compared to high spatial frequencies in MAMO 1 , it more or less reflects the actual changes in important features (microcalcifications that are sign of precancerous tissue of the two mammograms). In the Fourier spectrum of MAMO 3 , the high spatial frequencies will increase due to the presence of clusters of microcalcifications and masses like cysts and/or tumors. A preferred embodiment of the present invention provides tracking of these changes in the important features of mammograms (MAMO 1 , MAMO 2 and MAMO 3 ) using the POC as well as spectral phase subtraction technique.
The POC technique is analyzed with binary images as shown in FIG. 19A-19C and phantom images with invisible microcalcifications as shown in FIG. 20 , FIG. 21 and FIG. 22 . As discussed earlier these images, FIGS. 20-22 , represent the stages of cancer over a period of time, MAMO 1 , MAMO 2 and MAMO 3 respectively. FIG. 20 consists of invisible bright random white spots that represent the random noise in the gray background that represents the soft dense tissue in the mammogram. In addition to these noise features of FIG. 20 , FIG. 21 consists of an invisible cluster of bright spots with a definite pattern to represent the formation of microcalcifications at this state. Besides the noise features of FIG. 20 and represent microcalcifications of FIG. 21 , FIG. 22 consists of features that resemble masses or cysts. This represents the advanced stage of cancer over a period of time.
If the reference image is same as the acquired image, the maximum value of the correlation peak that is obtained following the phase-only correlation (POC) method given in FIG. 17 is called the autocorrelation peak value. If the reference image and acquired image are different, then the maximum correlation peak value is called the cross correlation peak value.
The image in FIG. 20 can be used both as a reference as well as the acquired image to obtain the maximum autocorrelation peak value i.e. 3.3180. When the image in FIG. 20 is used as a reference and FIG. 21 as the acquired image, the maximum cross correlation peak value is 2.3734. Therefore the discrimination ratio is 0.7153. This indicates that there is 71.53% correlation between these two images. This correlation is due to only the important features of interest, i.e. high spatial frequencies (due to random noise) present in both the images as the background due to low frequencies are not included in the correlation method and are suppressed as phase-only information of the images is used in the correlation process. The 30 percent drop in the correlation is due to the cluster of simulated microcalcifications that are present in the image of FIG. 21 .
When the image in FIG. 20 is used as a reference image and FIG. 22 as the acquired image the maximum cross correlation peak value is 1.5667. Therefore the discrimination ratio is 0.4722. This indicates that there is only 47.22% correlation between these two images. This correlation is due to only the essential features of interest, i.e. high spatial frequencies (due to random noise) present in both the images, as the background due to low frequencies are not included in the correlation method and are suppressed as phase-only information of the images is used in the correlation process. The 52.78% drop in the correlation is due to the cluster of simulated microcalcifications as well as masses or cysts that are present only in the image of FIG. 22 .
The image in FIG. 21 is used both as both reference as well as a reference image to obtain the maximum autocorrelation peak value i.e. 3.3202. When the image in FIG. 21 is used as reference and FIG. 22 as the acquired image, the maximum cross correlation peak value is 1.7364. Therefore the discrimination ratio is 0.5230. This indicates that there is about 52.30% correlation between these two images. This correlation is due to only the essential features of interest, i.e. high spatial frequencies (due to cluster of simulated microcalcifications as well as random noise) present in both images as the background due to low frequencies are not included in the correlation method, and are suppressed as phase-only information of the images issued in the correlation process. The 48% drop in the correlation is due to the presence of masses or cysts that are present only in the image of FIG. 22 . The image in FIG. 23 is used both as both reference as well as the acquired image to obtain the maximum autocorrelation peak value i.e. 3.3614. When the image in FIG. 23 is used as reference and FIG. 24 as the acquired image, the maximum cross correlation peal value is 0.5540. Therefore the discrimination ration is 0.1668. This tells us that there is only 17% correlation between these two images. This correlation is due to only the non important features of interest related to high spatial frequencies (due to the lines and letters that don't relate to the embedded gold particles) present in both the images as the background due to low frequencies are not included in the correlation method, and are suppresses as phase-only information of the images is used in the correlation process. The 83% drop in the correlation is due to addition of tiny bright spots to the image in FIG. 24 .
A process sequence for spectral phase subtraction is shown in FIG. 26 . Since the phase of the Fourier transform contains the important features of an image, the changes in the feature of subsequent images obtained over a period of time can be tracked using this technique. The phase-only information of prior image is subtracted from the phase-only information of the current image. This residual information is inverse Fourier transformed to reconstruct the residual image. Our results show that these residual images clearly display only the changes in the important features (high spatial frequencies) between these two images.
The residual phase-only image shown in FIG. 29A is obtained by subtracting phase-only information of FIG. 20 from phase-only information of FIG. 21 following the method given in FIG. 26 . This residual image clearly shows only the changes in the important features, i.e., changes in high spatial frequencies, (cluster of simulated microcalcifications) between these images. The background present in two images is suppressed because we used both images canceled out during the subtraction process.
The residual phase-only image shown in FIG. 29B is obtained by subtracting phase-only information of FIG. 20 from phase-only information of FIG. 22 following the method given in FIG. 26 . This residual image clearly shows only the changes in the important features, i.e. changes in high spatial frequencies, (cluster of simulated microcalcifications and masses with their shape and edge) between these images. The background present in two images is suppressed because we used phase-only information for subtraction, while high spatial frequency component due to random noise that is present in both images canceled out during the subtraction process.
The residual phase-only image shown in FIG. 29C is obtained by subtracting phase-only information of FIG. 21 from phase-only information of FIG. 22 following the method given in FIG. 26 . This residual image clearly shows only the changes in the important features, i.e. changes in high spatial frequencies, (masses with their shape and edge) between these images. The background present in two images is suppressed because we used phase-only information for subtraction, while high spatial frequency features due to random noise as well as cluster of simulated microcalcifications that are present in both the images canceled out during the subtraction process. | The present invention relates to systems and methods for medical imaging. Digital images are processed to provide phase images of a region of interest to aid in the diagnosis and treatment of various conditions. A preferred embodiment of the invention provides improved mammography screening for cancerous or precancerous conditions. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED-RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
INCORPORATION BY REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
[0003] Not Applicable.
FIELD OF THE INVENTION
[0004] The invention disclosed broadly relates to the field of information processing systems and more particularly relates to the field of migration of software from mainframe environments to non-mainframe architectures and platforms.
BACKGROUND OF THE INVENTION
[0005] Business process control software was historically performed on mainframe platforms. The introduction of microprocessor-driven computing apparatus in the 1980s changed the world of computing and introduced a new paradigm for enterprise business process software that is not run on mainframes. However many enterprises have invested substantial sums of money on legacy mainframe software. There are typically 200-300 billion lines of application code consisting of millions of applications that currently reside on mainframe computers such as those provided by International Business Machines Corporation of Armonk, N.Y. These applications run the core business applications for approximately 6,000 companies and organizations, including most of the Global 1000. There is a need for a system and method to migrate these applications form a mainframe platform to non-mainframe platforms or architectures such as those running Windows operating systems.
SUMMARY OF THE INVENTION
[0006] Briefly according to an embodiment of the invention an information processing system comprises a legacy application, a web services consumption copybook, and a set of application program interfaces for enabling the legacy application to access a selected web service via a web services consumption server. The web services consumption copybook represents data structures of the selected web service. The system can either connect to or include a set of web service proxies that each correspond to a web service available via a network connection. A web services consumption server is optionally used to route service requests from the application to the appropriate web service proxy.
[0007] The system can also optionally include a developer tool for adapting legacy systems or environments to be able to consume web services using modern protocols thus allowing the migration of legacy subsystems to a networked loosely-coupled environment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a block diagram depicting an architecture according to the invention.
[0009] FIG. 2 is a block diagram depicting a computer readable medium comprising components according to an embodiment of the invention.
[0010] FIG. 3 is a flow chart illustrating a method according to the present invention.
DETAILED DESCRIPTION
[0011] A system and method using the invention solve a critical issue facing global corporations as they evaluate strategies to move their business applications from legacy mainframe computing platforms to modern architectures and platforms and technologies such as those using client-server or distributed computing paradigms.
[0012] Referring to FIG. 1 , there is shown an information-processing system 100 according to an embodiment of the invention. The system 100 comprises a legacy system 110 , a server 106 , a set of web services 104 and a developer tool 120 . The invention however can be used in a variety of configurations that generally enable systems that use the services of tightly coupled subsystems (legacy systems) to also use loosely coupled subsystems such as web services or other network services. The legacy applications include applications programs such as the COBOL (Common business Oriented Language) application program 102 that uses (i.e., consumes) services of legacy sub-systems. An example is an insurance system (application) that requests and receives services from a rating module or sub-system that is tightly coupled with the insurance system. According to an embodiment of the invention the application 102 can be adapted to use services of a web service provider 104 via a server 106 and the Internet 108 as opposed to the legacy subsystems hosted by the legacy system 110 . This process, called sub-system migration, has many advantages that will be apparent to those skilled in the art. One such advantage is that the use of service resources available through a network such as the world-wide web (web services) eliminates the need for an enterprise using the system 110 to maintain applications (sub-systems) hosted in the system 110 . Using the invention the application 102 can be a web service consuming application using the services provided by various software agents 104 .
[0013] As used herein, a “legacy” program or application is one that cannot directly consume web services. In most cases the legacy system is a mainframe computer such as those provided by International Business Machines Corporation but in other cases it could be any system or architecture that is not able to consume Web Services or other loosely coupled services directly.
[0014] According to an embodiment of the invention, the mainframe computer 110 is adapted to enable the application 102 to consume web services 104 that use data types that are not specific to common encoding schemes. Thus, the mainframe computer 110 is adapted in part by installing a set of application program interfaces (APIs) 112 into it that enable the application 102 to request the selected web services via a server 106 . The mainframe 110 uses these APIs 112 to direct requests or information to the web service consumption server software 114 hosted in the server 106 . The mainframe computer 110 is further adapted to allow for the application 102 to consume web services 104 by modifying the application 102 and integrating a web services consumption copybook 103 into the web service consuming application 102 . Alternatively, the copybook 103 can be stored in the system 110 so that the application 102 can interact with it without integration into the application 102 . The copybook 103 represents the data structures of the web services inbound and outbound operation messages that the application 102 needs to consume. COBOL and other mainframe applications readily use copybooks. The application 102 requires a transformation process that converts web messages (e.g., using an XML-compatible messaging protocol) into data and instructions that can be used by the application 102 . This transformation is delegated to an external web service proxy 116 . We use the term “web services” to refer to services provided by a web-based application using a common messaging protocol such as SOAP (simple object access protocol), XML-RPC (extensible markup language-remote procedure call), or XMLP (XML protocol).
[0015] The server 106 preferably uses a microcomputer operating system with a graphical user interface such as Windows™ operating system provided by Microsoft Corporation or a UNIX operating system and comprises a Web service consumption (WsC) server software 114 and a Web services consumption proxy 116 , conceptually disposed between the server 114 and the Web service source 104 . The web services consumption proxy 116 is preferably a dynamic link library (DLL) that is used to communicate with the web service 104 .
[0016] The system 100 addresses the business and technical requirements of systematically migrating these applications from the legacy mainframe computing platform to modern architectures and to integrate these systems into their service-oriented architecture (SOA) by allowing the legacy application 102 to consume web services 104 while a full migration to a web-services environment is completed. An SOA is an architecture that achieves loose coupling among interacting software agents. An example of a loose coupling is a set of computers that are linked to each other via a network and share each other's services.
[0017] The adaptation of the system 100 such that the application 102 consumes the web services 104 is preferably done at development time using a developer tool 120 that obtains information from the web services 104 and creates a copybook 103 for each service, a proxy 116 for the server 106 , and the APIs 112 for the legacy system 110 . The developer tool 120 includes in each proxy 116 web service access information such as the location of a particular web service.
[0018] Using the structure identified in the web services consumption copybook 103 , the COBOL program 102 can consume a web service 104 using the APIs 112 to request the service and the web services consumption server 112 to select the appropriate web services consumption proxy 104 . Then, the Server 114 channels the request through to the corresponding WsC proxy 116 . The proxy 116 converts the request including associated data into an appropriate format and communicates with the Web service 104 to fulfill the request. Once the service 104 returns processed information or other service, the system 100 directs the processed information back to the calling mainframe program 110 for use by the application 102 . The proxy 116 converts the information provided by the Web service 104 into a data format usable by the application 102 and sends that processed information using an appropriate transport mechanism or protocol.
[0019] Referring to FIG. 2 , the developer tool 120 can be implemented as a set of program instructions stored in a computer-readable medium such as a CD ROM or DVD or downloaded by users. The medium would include software for creating a web service interface 122 , a copybook 124 , and a set of APIs 126 . The information stored in the medium includes both instructions and data. The instructions and data are preferably installed into a computer system that is preferably separate from the mainframe legacy system 110 .
[0020] The program instructions in the medium are for seeking the information, from the various web services, that is required to create the components used to create the copybooks, APIs and proxies discussed herein. The set of APIs 126 comprises the APIs 112 for installation in the mainframe 110 . The Web Service Consumption software 114 is used for loading into a server, for example using an operating system such as the Windows™ operating system or other suitable operating system, a set of proxies 116 (one for each Web service 104 ); and a set of copybooks for defining the variables (working storage) for each Web service to be integrated into a new or existing legacy program.
[0021] A sub-system is a group of business functions that tightly relate to each other. The sub-systems are rewritten on SOA architectures, one at a time. While this is happening, the WsC system 100 allows an enterprise to still run the backend application on the mainframe and consume Web services from a large number of platforms. Sub-systems are not isolated from one another. For the entire system to operate, sub-systems need to communicate with each-other. During the long transition period that our approach mandates, communication must flow inbound to the Legacy system and outbound from the Legacy system. Over time, the logic on the mainframe can be completely moved to another platform, once the code has been re-written and tested.
[0022] This type of migration can span several years, and provides a pragmatic way of migrating legacy applications to SOA. Migration costs can now be spread across multiple years and therefore high priority developments are not disrupted.
[0023] Referring to FIG. 3 , there is illustrated a method 300 according to an embodiment of the invention that involves using a subsystem migration approach. The method 300 is preferably performed with the developer tool 120 . In step 302 the system parses a set of data expressed in a web services description language into a legacy structure. The data is associated with a request for processing by a selected web service.
[0024] In step 304 , a copybook is generated for the selected web service. The copybook defines a set of variables for the selected web service so that the web service consuming application can use the requested web service.
[0025] In step 306 a proxy for handing the selected web service is created. In step 308 the copybook is installed into a legacy system.
[0026] In step 308 an application program interface (API) is called for use by the application to request the selected web service from a proxy for that web service. The API is preferably installed in the legacy system so that it can use the web services consumption server software to request the selected web service from a corresponding web services proxy.
[0027] What has been shown and discussed is a highly-simplified depiction of a programmable computer apparatus. Those skilled in the art will appreciate that other low-level components and connections are required in any practical application of a computer apparatus. Therefore, while there has been described what is presently considered to be the preferred embodiment, it will be understood by those skilled in the art that other modifications can be made within the spirit of the invention. | An information processing system comprises a legacy application, a web services consumption copybook, and a set of application program interfaces for enabling the legacy application to access a selected web service via a web services consumption server. The web services consumption copybook represents data structures of the selected web service. The system can either connect to or include a set of web service proxies that each correspond to a web service available via a network connection. A web services consumption server is optionally used to route service requests from the application to the appropriate web service proxy. The system can also optionally include a developer tool for adapting legacy systems or environments to be able to consume web services using modern protocols thus allowing the migration of legacy subsystems to a networked loosely-coupled environment. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is the § 371 National Stage Entry of International Application PCT/IB2013/055428, filed on Jul. 2, 2013, which claims the benefit of United Kingdom Patent Application Serial No. GB 1212092.9, filed on Jul. 6, 2012, the contents of which applications are herein incorporated by reference in their entirety.
FIELD OF THE INVENTION
[0002] This invention relates to collapsible ladders and more specifically to increasing the stability of a extendible ladders when erected.
BACKGROUND OF THE INVENTION
[0003] Collapsible ladders are utilised because of the convenience they provide. They may be transported easily, such as in the boot of a car, and may be carried and erected by one man. It is beneficial for such ladders to collapse to the smallest possible size, whilst still allowing them to be erected to a useful height.
[0004] Reducing the physical dimensions to produce the smallest collapsed size has the downside of reducing the width of the footprint when the ladder is erected. A narrower footprint reduces the stability of the ladder, the degree of instability is more noticable the taller the ladder.
[0005] Previous solutions to this include the provision of removable feet located at the bottom of each stile which serve to widen the foot print of the ladder, but these are cumbersome to attach or remove each time the ladder is collapsed or erected dor transport.
SUMMARY OF THE INVENTION
[0006] With a view to mitigating the foregoing disadvantage, the present invention provides an improved extendable ladder. According to an embodiment of the present invention, an extendable ladder has a collapsed mode and an extended mode. When the ladder is transformed from the collapsed mode to the extended mode, at least one ground stabiliser extends laterally from the ladder to widen the footprint of the ladder.
[0007] Preferably, the stiles of the ladder may extend telescopically.
[0008] The at least one one ground stabiliser may be urged laterally outwards by a spring.
[0009] The at least one ground stabiliser may be retained in a retracted position by a pin engaged within a hole when the ladder is in a collapsed mode.
[0010] The pin may be resiliently biased towards the hole in the ground stabiliser.
[0011] The pin may be supported by one of the telescopic stiles of the ladder such that when the stiles slide relative to one another as the ladder is extended the pin is pulled out of the hole, releasing the ground stabiliser.
[0012] Preferably, at least two ground stabilisers may extend coaxially from each of the two stiles of the ladder.
[0013] The two ground stabilisers may extend from a hollow floor rung and are biased apart by a spring contained within the rung.
[0014] Preferably the motion of the ground stabiliser is damped.
[0015] Alternatively a podium may be provided comprising a rectangular platform and a ladder as described above, hingedly attached to each of two opposing sides of the platform.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The invention will now be described further by way of example with reference to the accompanying drawings in which:
[0017] FIG. 1 shows a sectional view of the lower most rung of a collapsed ladder embodying the present invention, with its ground stabilsers in a retracted position, and
[0018] FIG. 2 shows a sectional view of the lower most rung of a partially extended extended ladder embodying the present invention, with its ground stabilsers in an extended position.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0019] Turning now to FIG. 1 , a collapsible ladder embodying the present invention is shown. In this example a telescopic ladder 10 of the type described in U.S. Pat. No. 5,495,915. The dotted line to the right of the figures represents a vertical line of symmetry. The description provided here should be assumed to be duplicated about this line.
[0020] The ladder is formed of individual rungs 12 having two ends (one end 14 of each rung shown). Each end 14 is connected to and associated with a corresponding hollow stile section 16 . The stile sections 16 associated with a first rung 14 are larger in diameter than the stile sections 18 associated with a second rung 20 immediately above. As a result, the ladder 10 may be collapsed by sliding the stile sections 16 , 18 inside one another resulting in the collapsed ladder having rungs 12 , 20 which rest directly on top of one another.
[0021] To extend the ladder the rungs 12 , 20 are separated causing the stile sections 16 , 18 to slide telescopically apart. They continue to slide until a spring biased pin 22 , 24 arranged inside the ends 14 , 26 of each rung 12 , 20 engages with a hole 28 , 30 in the circumference of the stile section of the rung immediately above.
[0022] The spring biased pins 22 , 24 lock the stile sections 16 , 18 at the separation predetermined by the position of the holes 28 , 30 . Typically the rungs are separated starting with the bottom two rungs 12 , 20 and then working up the ladder 10 towards its top. This allows the height of the ladder to be chosen depending on the extension required.
[0023] As stability is increased by widening the foot print of the ladder, or increasing the distance between the outermost points of the foot of the ladder, the present invention is provided with extendable feet or ground stabilisers 32 .
[0024] These protrude at the outer circumference of the stiles 34 of the ladder where they meet the floor 36 . The stiles 32 are each provided with a curved high grip rubber foot 38 inserted into the hollow stile 32 to provide a better purchase on the ground 36 regardless of the angle of the ladder 10 . These feet define the width of the foot print of a standard ladder.
[0025] In the present invention, the ground stabilisers 32 may themselves be in either a retracted ( FIG. 1 ) or extended ( FIG. 2 ) position. In the retracted position, the ground stabilisers of the preferred embodiment increase the width of the foot print of ladder in the preferred embodiment, when compared to a ladder not so equipped. In some applications this may be undesirable and so is considered optional.
[0026] In an alternative embodiment, the ground stabilisers 32 may be integral to the outer circumference of the stiles 34 immediately adjacent the ground 36 such that when retracted the ground stabilsers 32 sit flush with the circumference of the largest diammeter stile portion at the foot of the ladder.
[0027] For ease of transportation, the ground stabilisers 32 are best maintained in the retracted position as shown in FIG. 1 . The stabilisers each consist of a cylinderical support tube 40 supported for axial movement within a transverse apertures 42 in the lowermost stile section. In an alternative embdiment, the stabiliser 32 may be supported within a plastic attachment including a foot portion to be attached the bottom of each stile 34 . In this preferred embodiment, the apertures 42 for supporting each tube of each ground stabiliser are coaxial and joined by a hollow ground tube 44 .
[0028] The stabilisers 32 are urged outwards by means of a resilient member 46 such as a spring acting between the inner most ends 48 of both ground stabilisers 32 . The resilient member 46 is retained within the hollow ground tube 44 running at almost ground level between the stiles 34 . It is raised slightly from the ground to allow the ladder to be used on uneven ground without the ladder 10 rocking on the ground tube 44 .
[0029] The ground stabilisers 32 are retained in their retracted position against the force of the resilient member 46 in a similar manner to the way in which the stiles of the ladder are locked in the ladder's extended position. The support tube 40 of each ground stabiliser 32 is provided with a hole 50 in the upper most section of its circumference such that each is aligned with the axis of the respective stile 34 .
[0030] A resiliently biased pin 52 extending from stile section 18 of rung 20 , mates with the hole 50 preventing the resilient member 46 from forcing the ground stabiliser 32 outwards.
[0031] When the ladder is extended ( FIG. 2 ) and the rungs ( 12 , 20 ) separated, the stile section 18 carrying the resiliently biased pin 52 is moved upwards and clear of the hole 50 causing the ground stabilisers 32 to extend laterally. | An extendable ladder having a collapsed mode and an extended mode, characterised in that when the ladder is transformed from the collapsed mode to the extended mode, at least one ground stabiliser extends laterally from the ladder to widen the footprint of the ladder. | 4 |
[0001] This is a non-provisional application of provisional patent application No. 61/560,352 filed on Nov. 16, 2011, and priority is claimed thereto.
FIELD OF THE PRESENT INVENTION
[0002] The present invention relates to a dating or mate matching service configured to match individuals together based on the compatibility of their blood types as though the male was the donating party and the female was the receiving party of the hypothetical blood transfer. The system is internet-based, and provides services via a secured server computer hosting content and comparisons of individuals to the internet. It is the intent of the present invention to appropriately match individuals to each other based on the inherent compatibility of their individual blood types, based on the theory that couples with compatible blood types are more likely to have healthier offspring and more fruitful relationships than couples with incompatible blood-types.
BACKGROUND OF THE PRESENT INVENTION
[0003] In the modern age of computers and meals on-the-go, people have seemingly even less time on their hands to devote to dating. Often people work 8 to 10 hours a day, returning home exhausted, only to rise and repeat the routine over again the next day, leaving little time for serious dating. Many services have been crafted to combat this time constraining issue, including everything from speed dating meetings at physical locations in town, or compatibility matching websites, such as Match.com™ or E-harmony.com™ designed to expedite and increase the efficacy of the dating process. These sites function as expected, conventionally matching individuals based on similar interests and personality comparisons, and allowing the user to dynamically set custom criteria pertaining to what characteristics the individual is ideally searching for in a mate, such as age, physical characteristics, and other common traits. While the intention of these services isn't to replace dating altogether, they are designed to facilitate meeting people with a higher propensity of exhibiting the characteristics of an ideal mate.
[0004] However, many characteristics are left out of these dating services which could also be useful in the search for the best pool of potential mates. Genetic traits, such as a higher propensity for disease or an increased risk of stroke, blood-type, or simply the recessive trait of red hair could be of interest to certain individuals. Of the omitted traits, blood-type may be one of the most pertinent and relevant qualities of an individual, as recent studies have shown a correlation between potential birth-defects and mismatched blood-types in couples. Evidence has shown that, if the two parents of a child do not possess blood-types compatible with one another, then the resulting alleles constituting the child's blood could be in conflict with those of the mother, potentially contributing to birth defects, birth complications, miscarriages, abnormal growth, and/or a shorter lifespan. It is only with recent technology and medications that doctors have been able to save the lives of babies in utero to combat this act of the human body, in the mother's womb, to attempt to reject the baby prior to birth, given that the mother's blood is incompatible with the baby's.
[0005] The primary means by which a couple can avoid these scenarios is by verifying that their blood-types are compatible prior to bearing children. Unfortunately, this is often not prevalent in the minds of many couples. In fact, many individuals are not even aware of their own blood-type, let alone their partner's. If there were a way to present individual's blood-types in advance, prior to engaging in the courtship or dating process, such instances of couples bearing a child with a conflicting blood-type from that of the mother would be likely be less common.
[0006] Thus, there is a need for a method and system by which individuals may meet each other with the foreknowledge of each other's blood-types, helping to ensure that if the couple were to foster a relationship, that their offspring would have the least likelihood of pregnancy complications.
SUMMARY OF THE PRESENT INVENTION
[0007] The present invention is a blood-type date matching service presented on a website, hosted by a secured server computer, and configured to connect individuals together based on common blood-type alleles. The preferred embodiment of the present invention exists as an interactive social website, crafted to match individuals to a pool of other individuals maintaining a blood-type compatible with the suitor for transferring or donating blood. Individuals are categorized on the website according to their blood-type, be it A, B, AB, or O, and all the positive and negative accentuations of each. Individuals wishing to be matched to other individuals based on blood-type compatibility preferably must first create a user profile on the website. The profile must indicate what the individual's blood-type is, which must be submitted to the site upon profile creation. In the event that an individual does not know his or her blood-type, the website of the present invention is configured to supply blood testing kits to these individuals for a nominal fee. The conventional testing kits are designed to be easy to use without additional assistance, and to collect blood into a vial or other small container with relative ease. The blood may then be mailed securely and sanitarily in a preferably prepaid and pre-addressed envelope to a blood testing center in order to determine the individual's blood-type. After the individual's blood-type has been confirmed, the individual's profile is now complete, and he or she may begin to use the service and website of the present invention.
[0008] Individuals are matched as though the male was giving the female a blood donation; however ideal candidates will be able to share blood between each other regardless of gender. Therefore, preference will be granted to those individuals with an identical blood type to the user, who will be listed as ‘top matches’ upon executing a search for matches from the pool of users of the present invention. If the user performing the search is male, then in the event that the user is not presented with an appealing prospect within the list of ‘top matches,’ the user will preferably be presented with a list of ‘good matches,’ which includes all female individuals with a blood-type who maintain the capacity to receive a blood donation from the user. These matching users must then share one of two alleles composing his blood-type. If the user performing the search is female, the list of ‘good matches’ will only include individuals who may donate blood to her without complications.
[0009] For example, if ‘individual A’ is a male with a blood-type of B+, then upon registering for the service of the present invention, ‘individual A’ will first be presented with a list of ‘ideal’ matches, namely exclusively females with a blood-type of B+ as well. These individuals matching the blood-type of B+ will preferably be displayed in a list form, with photos accompanying each profile match, and potentially maintain numerous pages of individuals; therefore, other qualities and characteristics may be added to help facilitate effective searches to narrow the result set. This is preferably accomplished via conventional tagging protocols, which associate cultural preferences, conventionally known on most social network services as ‘likes’, physical characteristics, educational background, personal summary, etc.
[0010] These additional characteristics are commonly known to be the more conventional way of matching couples, based on preferences and commonalities via personality testing and hypothetical questioning. The present invention employs these conventional methods of matching couples together, but simply places a global filter on all results, such that an individual is only matched to other individuals who have a compatible blood type. This ensures that if the couple were to be a successful match, then the potential offspring of the union would not be as subject to the common disorders and issues that can plague babies born with blood that is incompatible with the mother's. It is the intent of the present invention to help prevent birth defects and potential issues encountered when the child's blood is incompatible with the mother's, through the use of selected genetics in the form of the matching of couples' blood-types.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 displays the preferred embodiment of the website of the present invention.
[0012] FIG. 2 exhibits the preferred embodiment of a standard user's profile page.
[0013] FIG. 3 shows the sign-up and profile creation process of the website of the present invention in the form of a flow chart-.
[0014] FIG. 4 shows the blood-type matching rules (as donated male to female) that are employed by the system of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] The present invention, an online, website-based couples matching service, preferably hosted by a secured server computer, configured to document and display an array of users personal information, specifically the users' blood-types, as well as other information, to a set of other users of the system with the intent of matching individuals together based primarily on the compatibility of the individuals' blood-types. The system is configured to set the blood-type qualifier for a potential match to be the forefront or premier qualifier used to search for ideal match candidates. In order to utilize the system of the present invention, a visitor must first become a member or user by signing up and providing personal information to create a unique user profile, which includes being prompted to upload a profile picture ( 380 ), providing a detailed personal description ( 360 ), and select a unique username ( 370 ).
[0016] The present invention preferably presents visitors to the website with the direct option to ‘Sign-up’ ( 60 ) for the service upon visiting the website for the first time. Visitors may click the signup ( 60 ) button in order to create a profile and become an official member and user of the system. However, in order to become a user, visitors must provide basic information about themselves during the profile creation process. The process initiated by clicking the signup ( 60 ) button is outlined in FIG. 3 . The premier mandatory information required for profile creation is the visitor's blood-type, which is displayed by the blood-type indicator ( 130 ) seen on the profiles of all users. In the event that the visitor is not aware of his or her blood-type, the visitor may not become a user until the blood-type has been identified. The website of the preferred embodiment of the present invention provides the visitor with a means of determining his or her blood-type via a third party blood-testing kit. This blood-testing kit may be purchased from the website of the present invention, which will arrive to the visitor's location of choice, preferably via standard mail. It can be envisioned that a fee may be associated with the act of becoming an official member of the website of the present invention. Similarly, it can be envisioned that, if a visitor wishes to become a user, yet must order a blood-testing kit in order to provide an accurate portrayal of the visitor's blood-type; then, the user may be eligible for a discounted rate of membership, given that the blood-testing kit was paid for. Thus, it is contemplated that the cost of the blood-testing kit could offset the cost of a membership, or perhaps entitles the user to a free month of membership of the service of the present invention.
[0017] ‘Ideal’ matches primarily consist of a set of users of the service of the present invention who maintain a blood-type identically matching that of the user searching for matches. Subsequent search results will include not only identical matches, but all compatible matches as well, namely, those users who share at least one common blood type allele together, namely A, B, or O. This search is preferably built upon the correlation of blood-types as depicted by the blood-type indicator ( 130 ) on a user's profile. Advanced searches for matches may also be performed, which go into greater detail based upon an array of search parameters, enhancing the efficacy of the search being performed by the computer. Searches may be quickly entered by the user by simply typing in qualities or search tags into the search field ( 20 ) found on any page of the website of the present invention, and clicking the search button ( 30 ). Indefinite quantities of tags or search criteria may preferably be entered into the search field ( 20 ); however, by default, the system of the present invention will only return individuals with a compatible blood-type. The compatibility of user's blood-types can be seen in FIG. 3 . Search tags are only limited by the input of the community of members or users of the present invention as depicted in their custom user profiles. User profile creation is preferably performed by the user upon clicking signup ( 60 ) and entails the user elaborating about his or herself, as well as listing preferences and qualities, which may conventionally appear in a search. Additionally, the user will select a unique username ( 120 ) upon profile creation. If a user's profile is not completed during the signup process, then the user may later be able to edit his or her profile settings with the Edit Profile ( 70 ) button found under the ‘Profile’ ( 50 ) menu. It can be envisioned that a user's profile may be linked to other online profiles such as Facebook™ and Twitter™. Profiles may be further enhanced via a series of questions designed to help exhibit the user's online personality, such as conventional online quizzes.
[0018] Additionally, the preferred embodiment of the present invention is preferably configured with a robust messaging system designed to facilitate communication between users. It can be envisioned that the present invention maintains both a conventional instant messaging system, as well as a traditional email messaging system integrated into the website of the present invention. In order to communicate directly with another user, a user may select the Compose a Message button ( 180 ) preferably found in the left column on the homepage of the website of the present invention, as seen in FIG. 1 . Additional messaging options, such as viewing prior messages, deleting messages, archiving messages, and other common options can be accessed via the message center, accessible by clicking on the View Messages button ( 190 ) from the home page. The View Messages button ( 190 ) brings the user to the message center, which functions similarly to a conventional email client.
[0019] Users also have the capability of viewing the profiles of users who have actively viewed their own profile, thus displaying interest in the individual. Users may easily view the profiles of the individuals that visited their profile by clicking on the View Visitors button ( 220 ), preferably found on the left panel of the home page, as seen in FIG. 1 . The user is preferably free to send a message any other user, regardless of his or her blood-type. A user may easily message another user while viewing the target user's profile, and clicking the Message This User button ( 520 ) preferably found in the toolbar column on the left side of the window, as seen in FIG. 2 .
[0020] Other useful information can be found while viewing the profile of another user. If the user finds a match that seems appealing and worth additional investigation, he or she may click on the target user's profile picture ( 150 ) or username ( 120 ), which will cause the computer server to return the specified user's profile page. This specific page is unique for each user, and contains personal information provided by the user, including but not limited to their blood type indicator ( 130 ), eye color, body type, height, age, hair color, and hobbies. Many of these can preferably be found in the Quick Facts ( 580 ) portion of the user's profile page, as seen in FIG. 2 . A detailed description ( 550 ) of the user may also be provided which may include a personal summary, additional facts, or preferences. The user viewing another second user's profile may choose to ‘like’ and/or share any links or preferences found as displayed on the second user's profile.
[0021] Similarly, it can be envisioned that the website of the present invention could exhibit a conventional comment system, enabling users to comment on user's profiles, posts, shared website hyperlinks (shown as ‘user's links’ ( 560 )), profile picture(s) ( 150 ), and other web content provided at the discretion of the user. Comments would preferably be archived by the computer server, and held to be readily accessible by any other user for a pre-determined period of time. Any user's prior comments can be seen by clicking on the ‘View Notes About This User’ link ( 520 ) preferably found on the left column of a user's unique profile page. Clicking the ‘View Notes About This User’ link ( 520 ) of the present invention will return all comments and their corresponding links, posts, or other content within the reach of the comment system. Additionally, users could decide to ‘like’ other user's links ( 590 ), and share them to other social networks, providing full social network integration to the website of the present invention. As an expansion to the concept, it is similarly contemplated that user's could choose to select a preferred user and designate him or her a ‘favorite’ by pressing the ‘Add to Your Favorites’ button ( 540 ) as seen in FIG. 2 . Favorites selected by the user of the website and service of the present invention may be viewed at any time by clicking on the View Favorites button ( 160 ). The ‘favorites’ designation is instrumental at times when a user wishes to attempt to contact another user as a potential match, but simply wished to wait until adequate time was available to construct a meditated message as a first contact. The concept of ‘favorites’ is known to be conventional with respect to websites, such as a user profile, that is desired to return to later.
[0022] Alternate embodiments of the present invention could include a subsidiary service preferably designed to send periodic automated emails to all users featuring users that the system deems as matches in accordance with a set of protocols, executed on the secured server of the present invention, fashioned to compare users based on their blood-type compatibility first, and their profile descriptions and preferences second. Within the emails, users will be presented with a number of these potential matches, along with their corresponding profile photos ( 150 ), at which time they may choose to directly message the potential match, favorite the user's profile to return to later, or simply delete the email.
[0023] Another embodiment of the present invention could feature additional methods of connecting two users who are unfamiliar with each other's profiles. For example: on the website of the present invention, users could elect to participate in a form of speed matching, which could be similar to ‘speed dating’ in the physical world. Compatible users would be selected at random, and would appear in a private chat room at the will of the user, so that the two strangers could have the chance to meet immediately. It can be envisioned that web cameras could be employed to facilitate face-to-face communication during the chat sessions. At any time, either user has the option to end the conversation and move on to meet with another random user who maintains a compatible blood-type. It is contemplated that these users electing to meet via ‘speed matching’ could thereby manage to meet a maximum number of compatible users in a short amount of time, increasing the likelihood that an acceptable match is found.
[0024] An additional embodiment of the present invention could feature a community calendar element which would present a series of events that could facilitate the meetings of users in the physical world. These meet-ups could be based on blood-type, so that all attending users would not necessarily feel self-conscious of their blood-type while meeting other users as potential mates. These calendar events could be specifically sponsored by the service of the present invention, and would preferably feature ice-breaker activities designed to help participants get to know each other swiftly, in a broad or general manner.
[0025] It is similarly contemplated that a form of verification process could be implemented in the event that a visitor does not require the third-party blood-testing kit provided for a preferably nominal fee. If the kit is not purchased, then the visitor has knowledge of his or her blood-type from an outside source, such as a blood clinic or blood donation site. However, it can be envisioned that the visitor may not become a full user without verifying his or her blood type with a scan or fax of the physical paperwork from an external source such as a clinic, indicating the individual's blood-type. This form may be presented in the form of an image on the user's profile on the website of the present invention, to provide proof of his or her blood type.
[0026] Having illustrated the present invention, it should be understood that various adjustments and versions might be implemented without venturing away from the essence of the present invention. Further, it should be understood that the present invention is not solely limited to the invention as described in the embodiments above, but further comprises any and all embodiments within the scope of this application. | An interactive website, preferably hosted on a secured server, fashioned to simplify and expedite the dating process by matching individuals to other individuals of the opposite sex based primarily on the compatibility of the individuals' blood-types. With respect to the online service of the present invention, blood-type matches are suggested based on the compatibility of a hypothetical blood donation flowing from male to female. Knowledge of one's blood-type is required to become a user. Other characteristics may be implemented to help narrow search results, which may be edited on a user's profile page, distinguishing individuals by preferences, qualities, and appearance. | 6 |
[0001] This application claims priority to Taiwan Patent Application No. 096101795 filed on 17 Jan. 2007.
CROSS-REFERENCES TO RELATED APPLICATIONS
[0002] Not applicable.
FIELD OF THE INVENTION
[0003] The subject invention relates to a heat dissipation structure with high heat dissipation efficiency, especially for a carbon substrate coated with a metal layer.
BACKGROUND OF THE INVENTION
[0004] The recent development of electronic devices, such as liquid crystal displays (LCDs), plasma televisions, light emitting diodes, central processing units (CPUs) of computers, medical equipments, office equipments, and communication units, have been gearing towards the miniaturization. However, miniaturizing electronic devices complicates circuit design. Moreover, the heat that is generated by these electronic devices will need to be dissipated more efficiently.
[0005] To spread the generated heat efficiently, many heat dissipation methods, elements and materials have been proposed. Conventional electronic devices and similar devices have focused on improving the heat dissipation module. All of said heat dissipation modules use metal sheets with a high thermal conductivity, e.g., aluminum (thermal conductivity coefficient of 226 W/mK), copper (thermal conductivity coefficient of 385 W/mK) or other metal alloy, as the heat dissipation material. These heat dissipation modules compare the temperature of the outside air with the temperature of the heat on the element's surface to dissipate the heat energy when needed. Thus, the temperature can be decreased during the operation of the electronic element.
[0006] The mass of the metal material, e.g., copper, aluminum, or an alloy thereof, is, however, problematic for use in heat dissipation sheets. For example, the density of pure copper is 8.96 g/cm 3 and that of pure aluminum is 2.70 g/cm 3 . Particularly, in the heat dissipation system of most circuit boards, it is necessary to deposit a plurality of heat dissipation structures to dissipate the heat energy generated by each element of the circuit board. However, when the circuit board contains many heat dissipation sheets made of metal materials, the metal net weight not only increases the total weight of the circuit board, but also increases the possibility of the board cracking due to the heavy load. Furthermore, to maximize the heat dissipation benefit, generally, the heat dissipation structure is completely connected with the electronic element. In this aspect, most of the electronic elements per se are also made of metals or other relatively rigid materials (such as alumina or ceramic materials), and these materials are irregular and deformability. Therefore, a relatively high pressure riveting is needed to allow the metal heat dissipation sheet to be completely connected to the electronic element. Unfortunately, the high pressure riveting can easily damage the electronic elements and thus, cause problems.
[0007] To address the problem with using metal heat dissipation sheets, graphite material has been substituted for use as the heat dissipation sheet. Graphite is lightweight, cheaper and also has a good heat dissipation efficiency. U.S. Pat. No. 5,831,374, assigned to Makoto Morita et al., discloses the use of a high-orientation graphite film to dissipate the heat in a plasma display panel. In U.S. Pat. No. 6,482,520, assigned to Jing Wen Tzeng, the exfoliated graphite particles were compressed to form a sheet for use as a heat spreader. The spreader can rapidly transfer the heat energy produced by the electronic elements to dissipate the heat. Advanced Energy Technology Inc. located in Lakewood, Ohio, U.S.A. has also commercially sold the aforementioned materials using the trade name eGRAF®. The product is widely used in thermal spreaders and heat sinks.
[0008] In U.S. Pat. No. 6,482,520, the graphite sheet has a thermal conductivity coefficient of 7 W/mK in a direction perpendicular to the carbon layers (also called the c direction) and 150 to 200 W/mK in a direction parallel to the carbon layer (also called the a direction). Moreover, Advanced Energy Technology Inc. contends that the graphite sheet product eGRAF® made by natural graphite flakes can have a thermal conductivity coefficient of 7 to 12 W/mK in a direction perpendicular to the carbon layers and 20 to 200 W/mK in a direction parallel to the carbon layer using different manufacturing processes. However, although the graphite sheet has excellent heat dissipation efficiency in the direction parallel to the carbon layer, it is not as efficient in the direction perpendicular to the carbon layers. In addition, the graphite sheet is susceptible to the falling of dust. When the graphite sheet is used in electronic elements, it is very likely that the falling of dust will short circuit the elements.
[0009] With the development of 3C industrial technology, it has become increasingly important to find a way to efficiently and rapidly dissipate the heat generated by electronic elements. As a result, there is a need for finding a material that is capable of rapidly dissipating heat.
SUMMARY OF THE INVENTION
[0010] The subject invention provides a heat dissipation structure, comprising: a carbon substrate, and a metal layer, which at least partially covers a sidewall of the carbon substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a schematic drawing of the heat dissipation structure according to one embodiment of the subject invention.
[0012] FIG. 2 is a schematic drawing of the heat dissipation structure according to another embodiment of the subject invention.
DESCRIPTION OF THE INVENTION
[0013] The carbon substrate of the heat dissipation structure of the subject invention comprises a carbonaceous component selected from a group consisting of: carbon, activated carbon, graphite, and a combination thereof. The carbon substrate should preferably comprise graphite. The carbonaceous component of the carbon substrate is generally in the form of powder, particle, sheet, fiber, or fabric. In one preferred embodiment, the graphite material is used as the carbon substrate. The graphite material can be selected from a group consisting of, for example, but not limited to: natural graphite (such as natural flake graphite and exfoliated graphite), artificial graphite, and a combination thereof. The carbon substrate should preferably also comprise natural graphite flakes and/or exfoliated graphite. The carbon for use in the carbon substrate of the subject invention comprises: diamond carbon powder, a carbon nanotube, a carbon fiber, a carbon black, and a combination thereof. The carbon fiber can be selected from a group consisting of: fringed carbon fiber, vapor-grown carbon fiber, and a combination thereof.
[0014] In addition to the carbonaceous component, the carbon substrate can optionally contain other materials with high thermal conductivity. The material with a high heat conductivity can be selected from a group consisting of, for example, but not limited to: Cu, Al, Ni, Au, Ag, an alloy of the foregoing metals, silicon carbide, boron nitride, and a combination of the foregoing components. The optional material with a high thermal conductivity can be in power, filament fabric or fiber form. Based on the total volume of the carbon substrate, the amount of the high thermal conducing material can be about 0.05 to 20 vol. %.
[0015] According to the subject invention, the carbonaceous material and the optional high thermal conducing material can be compressed into the desired shape. For example, when the carbon substrate of the subject invention is added with a metal material that has a high thermal conductivity, such as Cu, Al, Ni, Au, and Ag, the carbon substrate can be shaped using squeeze casting or powder metallurgy. With squeeze casting, the metal is heated and melted and then poured into a pre-shaped material. Afterwards, the metal is compressed until it is solidified. Moreover, with powder metallurgy, the metal powder and the particles (or flakes or fringes) of the carbonaceous component, such as graphite, are rapidly mixed, pressed, and air-ejected, and then subjected to the final solidification using a thermal processing manner, such as extruding swaging or calendaring. The carbon substrate can be in any of the following forms, sheet, block, squamose or corrugation, but is not limited to any particular form.
[0016] The density of the shaped carbon substrate changes as materials are added. However, without other components (i.e., the carbon substrate substantially consists of the carbonaceous material only), the density of the carbon substrate normally ranges from 0.02 to 2.25 g/cm 3 , preferably from 0.1 to 2.25 g/cm 3 , and more preferably from 1.5 to 2.25 g/cm 3 .
[0017] The metal layer in the heat dissipation structure of the subject invention is provided by using any metal material for heat dissipation, e.g., Cu, Al, Ni, Au, Ag, an alloy of the foregoing metals, or a combination thereof. In one embodiment, Cu is used as the metal layer. The metal layer needs to at least partially cover the sidewall of the carbon substrate. As shown in FIG. 1 , a heat dissipation structure 10 comprises a carbon substrate 100 and a metal layer 200 , wherein the metal layer 200 is partially coated on one sidewall of the carbon substrate 100 . The metal layer 100 can also be non-continuously coated on the sidewall of the carbon substrate 100 , as shown in FIG. 2 . Moreover, the metal layer-coated region on the sidewall of the carbon substrate can have an uneven edge and be different from those illustrated in FIGS. 1 and 2 . The metal layer should preferably be coated on the entire surface of one sidewall of the carbon substrate. It is best if the whole surface of the carbon substrate can be coated with the metal layer. Although the thickness of the metal layer is not critical to the subject invention, it does factor into weight and costs. The metal layer typically has a thickness ranging from 0.001 μm to 1 mm, preferably from 0.01 μm to 0.5 mm.
[0018] The metal layer can be coated on the carbon substrate surface using any suitable electrochemical method, such as electroforming, electroplating, or electroless plating. However, the electroplating method is the cheapest and most convenient to coat the metal layer onto the carbon substrate. As mentioned above, the carbon substrate coated with a metal layer on its partial sidewall is sufficient enough to provide a heat dissipation structure exhibiting excellent thermal conductivity in not only the parallel direction but also the perpendicular direction. In this aspect, the carbon substrate can be directly placed into an electroplating solution for conducting the electroplating to obtain a carbon substrate entirely coated with a metal layer. If a carbon substrate partially coated with a metal layer is desired, a pre-treatment such as applying an oily gel to the portion which is not desired to be coated needs to be conducted before the placement of the substrate into an electroplating bath. As the electroplating is completed, the oily gel on the carbon substrate is then taken off with the use of a solvent. Thereafter, a carbon substrate partially coated with a metal layer is produced.
[0019] Since the sidewall of the carbon substrate in the heat dissipation structure of the subject invention is coated with the metal layer, the thermal conductivity in the perpendicular direction is improved. Moreover, if the metal layer is coated on the whole surface of the carbon substrate, there would not be a falling of dust, and thereby, preventing short circuit. Furthermore, it has been found that when a manufacturing method involves compressing to prepare the carbon substrate required in the heat dissipation structure of the subject invention, the heat dissipation structure substantially has superior thermal conductivity in a parallel direction to that provided by the prior heat dissipation carbonaceous materials. In other words, the heat dissipation structure of the subject invention not only is lightweight and cheap, but it also provides better heat dissipation efficiency and prevents the aforementioned drawbacks.
[0020] Because the substrate and the metal layer of the heat dissipation structure of the subject invention have electrical conductivity, an insulating layer such as resin and rubber can be optionally provided on one or more surfaces of the heat dissipation structure as desired. This can be done by a couple of process, sticking or coating, to bind the insulating layer and the heat dissipation structure.
[0021] The heat dissipation structure of the subject invention can be used in many heating devices to provide heat dissipation. For example, the heat dissipation structure is bound to a heat generating source such as light emitting diodes, various displays (e.g., plasma display or liquid crystal display), central processing units of computers, or various lamps by a heat-transfer gel to attain the purpose of heat dissipation.
EXAMPLES
[0022] The subject invention is further illustrated by the following embodiments. The testing equipments and methods are described below:
[0023] (A) Density measurement
Equipment: Electronic Densimeter (Mode: MD-200S), MIRAGE, Japan Method: The density (p) is measured using Archimedes principle.
[0026] (B) Measurement of thermal conductivity coefficient
Equipment: Mode Micro30 produced by HOLOMETRIX Corp. Method: According to ASTM 1461 C714, a laser light beam is emitted on the bottom surface of a sample and then the surface temperature variation on the opposite surface is detected. Thus, the thermal diffusion coefficient (α) and the thermal conductivity coefficient (k) can be obtained. The equation for calculating the thermal conductivity coefficient (k) is expressed as follows:
[0000] k =(α)(ρ)( C p ) k: thermal conductivity coefficient (W/mK) α: thermal diffusion coefficient (cm 2 /s) ρ: bulk density (g/cm 3 ) C p : specific heat (J/g.K)
Example 1
[0033] Particular flake graphite (produced by INternational CArbide Technology Co., Ltd., No. CA002) was used as the raw material and was compressed to form a sheet with a thickness of 2.97 mm and a density of 2.211 g/cm 3 . Then, the sheet was electroplated in 1M CuSO 4 aqueous solution with a current density of 100 mA/cm 2 for 300 seconds to form a copper layer on its surface. The thickness of the copper layer was about 1 μm.
[0034] The thermal conductivity coefficients of the graphite sheet that were not electroplated with the copper layer (C1) and copper-electroplated graphite sheet (E1) in both the direction parallel to the carbon layers and the direction perpendicular to the carbon layers were tested. The testing results are listed in Table 1.
[0000]
TABLE 1
Thermal
Thermal
conductivity
conductivity
Density
coefficient* 1
coefficient* 2
Sample
(g/cm 3 )
(W/mK)
(W/mK)
C1
2.211
343.5
18.3
E1
2.214
401.5
21.8
* 1 direction parallel to the carbon layers
* 2 direction perpendicular to the carbon layers
[0035] Table 1 shows that the flake graphite sheet has a thermal conductivity coefficient of 343.5 W/mK in the direction parallel to the carbon layers and 18.3 W/mK in the direction perpendicular to the carbon layers. The copper-electroplated flake graphite sheet has thermal conductivity coefficients of 401.5 W/mK and 21.8 W/mK in the parallel and perpendicular directions, respectively. The copper-electroplated flake graphite sheet also exhibited 17% and 19% more heat dissipation in the direction parallel to the carbon layers and the direction perpendicular to the carbon layers, respectively.
Example 2
[0036] The flake graphite (produced by INternational CArbide Technology Co., Ltd., No. CA002) was placed in a mixture solution comprising 95% concentration of H 2 SO 4 and 70% concentration of HNO 3 in a volume ratio of 3:2.5 for 15 minutes, and then washed with water until the pH of the graphite material reached 5 to 6. Afterwards, the graphite was dried at 70° C. for 24 hours and then heat treated under a nitrogen gas atmosphere for 5 seconds to produce exfoliated graphite.
[0037] The resulting exfoliated graphite had a thickness of 2.97 mm and a density of 1.750 g/cm 3 . The electroplating was conducted in 1M CuSO 4 aqueous solution with a current density of 100 mA/cm 2 for 400 seconds to form a copper layer on the sheet surface. The thickness of the copper layer was 1.5 μm. The thermal conductivity coefficients of the graphite sheet that were not electroplated with copper (C2) and copper-electroplated graphite sheet (E2) both in the direction parallel to the carbon layers and in the direction perpendicular to the carbon layers were tested. The testing results are listed in Table 2.
[0000]
TABLE 2
Thermal
Thermal
conductivity
conductivity
Density
coefficient* 1
coefficient* 2
Sample
(g/cm 3 )
(W/mK)
(W/mK)
C2
1.750
276.3
9.05
E2
1.759
340.6
10.4
* 1 direction parallel to the carbon layers
* 2 direction perpendicular to the carbon layers
[0038] Table 2 shows that the exfoliated graphite sheet has a thermal conductivity coefficient of 276.3 W/mK in the direction parallel to the carbon layers and 9.5 W/mK in the direction perpendicular to the carbon layers. The copper-electroplated exfoliated graphite sheet has a thermal conductivity coefficient of 340.6 W/mK and 10.4 W/mK in parallel and perpendicular directions, respectively. The copper-electroplated exfoliated graphite sheet exhibited 23% and 10% more heat dissipation in the direction parallel to the carbon layers and the direction perpendicular to the carbon layers, respectively.
[0039] The above two examples demonstrate that the use of a carbonaceous material as the raw material and a simple metal coating process can increase the whole heat dissipation efficiency of the substrate provided by the carbonaceous material.
[0040] The above examples are only intended for illustrating the embodiments of the subject invention and showing its technical features, not for limiting the scope of protection of the subject invention. Any arrangements of changes or equivalents that can be easily accomplished by persons having ordinary skill in the art are within the scope of the subject invention. The scope of protection of the subject invention is based on the claims attached. | A heat dissipation structure is provided. The heat dissipation structure comprises a carbon substrate and a metal layer which at least partially covers the sidewall of the carbon substrate. The metal layer covering the carbon substrate can not only increase the heat dissipation efficiency of the carbon substrate but can also eliminate the short circuiting of the elements when dust accumulates on them. | 8 |
This is a continuation of and claims priority to U.S. patent application Ser. No. 12/478,025, filed Jun. 4, 2009.
FIELD OF THE INVENTION
The present invention relates generally to skylight collimators.
BACKGROUND OF THE INVENTION
Briefly, a tubular skylight such as those mentioned in U.S. Pat. Nos. 5,896,713 and 6,035,593, both of which are owned by the same assignee as is the present invention and both of which are incorporated herein by reference, includes a tube assembly mounted between the roof and ceiling of a building. The top end of the tube assembly is covered by a roof-mounted cover, while the bottom end of the tube assembly is covered by a ceiling-mounted diffuser plate. With this combination, natural light external to the building is directed through the tube assembly into the interior of the building to illuminate the interior.
As understood herein, the tube with vertical sides reflects light, in the same angle each reflection, which angle depends on the sun's elevation in the sky and thus varying throughout the day, limiting the efficiency and effectiveness of the diffuser in controlling the distribution of light in the building.
SUMMARY OF THE INVENTION
The present invention has recognized that to optimize the light transmission through the cover, a collimator may be provided above the diffuser, and furthermore the collimator need not be specular.
Accordingly, a skylight assembly includes a skylight shaft and a collimator'assembly operably engaged with the shaft. The collimator assembly includes an axial series of multiple collimator segments. In the limit in which the number of segments in the series approaches infinity, the collimator assumes a curved shape in longitudinal cross-section. A first collimator segment defines a first collimating angle with respect to an axis of the collimator assembly and subsequent collimating segments define respectively different (and steeper) collimating angles with respect to the axis. The collimating angles can be oblique. The collimating angles (and in the limiting case, the curve of the assembly) can be established by the desired degree of collimation, the expected range of angles rat which sunlight enters the assembly, and the diameter of the entrance to the collimator.
In some examples, the collimating assembly includes a third collimating segment defining a third collimating angle different from the first and second collimating angles. The collimating segments can be successively less flared than each other. An upper collimating segment can be more flared than a lower collimator segment. The inside surface of the collimating assembly may be non-specular.
In another embodiment, a skylight collimator assembly has a first frustum-shaped collimator segment defining a first cone angle and a second frustum-shaped collimator segment connected to the first segment and coaxial therewith. The second segment defines a second cone angle more acute than the first cone angle.
In another aspect, a skylight has a skylight tube defining an upper end and a lower end, a skylight cover disposed above the upper end and permitting light to enter the tube, and a collimator assembly disposed below the lower end to receive light therefrom. The collimator assembly has a non-specular inside surface. A diffuser is disposed below the lower end of the collimator assembly. In some embodiments the assembly has multiple collimator segments.
The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view in partial cross-section of an example non-limiting tubular skylight showing an example environment of the collimator;
FIG. 2 is a cross-sectional view of the collimator as seen along the line 2 - 2 in FIG. 1 ;
FIG. 3 is a side schematic view showing collimator parameters;
FIG. 4 is a side schematic view of an alternate collimator assembly in which the number of segments approaches infinity, effectively establishing a collimator that is continuously curved at ever-steeper tangents in the longitudinal dimension;
FIG. 5 is a perspective view of an alternate collimator having a round-to-square configuration;
FIG. 6 is an elevational view of the collimator shown in FIG. 5 ; and
FIG. 7 is a top plan view of the collimator shown in FIG. 5 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring initially to FIG. 1 , a tubular skylight made in accordance with the present invention is shown, generally designated 10 , for lighting, with natural sunlight, an interior room 12 having a ceiling dry wall 14 in a building, generally designated 16 . FIG. 1 shows that the building 16 has a roof 18 and one or more joists 20 that support the roof 18 and ceiling dry wall 14 .
As shown in FIG. 1 , the skylight 10 includes a rigid hard plastic or glass roof-mounted cover 21 . The cover 21 is optically transmissive and preferably is transparent.
The cover 21 may be mounted to the roof 18 by means of a ring-like metal flashing 22 that is attached to the roof 18 by means well-known in the art. The metal flashing 22 can be angled as appropriate for the cant of the roof 18 to engage and hold the cover 21 in the generally vertically upright orientation shown.
As further shown in FIG. 1 , an internally reflective hollow metal shaft assembly, generally designated 24 , is connected to the flashing 22 . The cross-section of the assembly 24 can be cylindrical, rectangular, triangular, etc. Accordingly, while the word “tube” is used from time to time herein, it is to be understood that the principles of the present invention are not to be limited to a tube per se.
The shaft assembly 24 extends to the ceiling 14 of the interior room 12 . Per the present invention, the shaft assembly 24 directs light that enters the shaft assembly 24 downwardly to a light, diffuser assembly, generally designated 26 , that is disposed in the room 12 and that is mounted to the ceiling 14 or to a joist 20 as described in the above-mentioned '593 patent.
The shaft assembly 24 can be made of a metal such as an alloy of aluminum or steel, or the shaft assembly 24 can be made of plastic or other appropriate material. The interior of the shaft assembly 24 is rendered reflective by means of, e.g., electroplating, anodizing, metalized plastic film coating, or other suitable means.
In one example embodiment, the shaft assembly 24 is established by a single shaft. However, as shown in FIG. 1 , if desired, the shaft assembly 24 can include multiple segments, each one of which is internally reflective in accordance with present principles. Specifically, the shaft assembly 24 can include an upper shaft 28 that is engaged with the flashing 22 and that is covered by the cover 21 . Also, the shaft assembly 24 can include an upper intermediate shaft 30 that is contiguous to the upper shaft 28 and that can be angled relative thereto at an elbow 31 if desired. Moreover, the shaft assembly 24 can include a lower intermediate shaft 32 that is slidably engaged with the upper intermediate shaft 30 for absorbing thermal stresses in the shaft assembly 24 . And, a collimator-like lower shaft 34 can be contiguous to the lower intermediate shaft 32 and join the lower intermediate shaft 32 at an elbow 35 , with the bottom of the lower shaft 34 being covered by the diffuser assembly 26 . The elbow 35 is angled as appropriate for the building 16 such that the shaft assembly 24 connects the roof-mounted cover 21 to the ceiling-mounted diffuser assembly 26 . It is to be understood that where appropriate, certain joints between shafts can be mechanically fastened and covered with tape in accordance with principles known in the art.
As shown in FIG. 2 , the collimator-like lower shaft 34 referenced in FIG. 1 is presented in greater detail. As may now be appreciated, in non-limiting embodiments the collimator-like lower shaft 34 has an axial series of multiple collimator segments. It may further be appreciated that each collimating segment of the shaft 34 is successively less outwardly-flared from top to bottom than the one immediately above it.
The collimator-like lower shaft 34 shown in FIG. 2 has a top 36 and a bottom 38 . The top 36 of the shaft 34 may be contiguously engaged to the lower intermediate shaft 32 as described in reference to FIG. 1 above. The bottom 38 of the shaft 34 may be covered by the diffuser assembly 26 as also described above. The bottom of the collimator may also, be left open without a diffuser assembly engaged therewith.
Also as stated above, the shaft 34 has multiple collimating segments. In some embodiments the collimating segments are frusto-conical. In other embodiments they may assume other collimating shapes, e.g., frusto-pyramidal.
Thus, there may be a first frustum-shaped collimating segment 40 defining a first collimating angle α 1 with respect to an axis of the collimator assembly 24 and a second frustum-shaped collimating segment 42 connected to the segment 40 and defining a second collimating angle α 2 that is less than the first collimating angle with respect to an axis of the collimator assembly 24 . Furthermore, in non-limiting embodiments there may also be a third frustum-shaped collimating segment 44 connected to the segment 42 and defining a third collimating angle α 3 that is less than the first and second collimating angles. It is to be further understood that each collimating angle referenced in the present application may be oblique. Additional segments may be provided in accordance with disclosure below.
Still referencing FIG. 2 , the collimating segment 40 is more flared than the collimating segment 42 . Similarly, in non-limiting embodiments that include a third collimating segment 44 , the collimating segment 42 is more flared than the third collimating segment 44 . Should there be more than three collimating segments, each upper collimating segment may be more flared than the one below it.
Last, it may also be appreciated from FIG. 2 that there is an inside surface 46 of the collimating assembly 24 . The inside surface 46 of the assembly 24 is understood to be non-specular in, non-limiting embodiments. Examples of such non-specular surfaces are disclosed in the present assignee's U.S. Pat. No. 7,146,768 and USPPs 2006/0191214 and 2007/0266652, incorporated herein by reference. In brief, the non-specular inside surface can be established by a structured surface in the metal substrate, reflective film or adhesive on the film. It can be in the form of dimples, corrugated patterns or other shapes known to provide a controlled spread of light of, e.g., less than about ten degrees. Using a non-specular surface provides a controlled light spread as desired, e.g., a spread of light that is less than plus or minus five degrees from the central reflected ray of light.
The multi-stage collimator described above advantageously consumes less axial space than a single stage collimator yielding equivalent performance.
With greater specificity and with the understanding that the discussion below is not intended to limit the invention but rather provide background explanation, the following terms are used. Refer to FIG. 3 . “SALT” (in degrees) refers to the solar altitude, angle of the sun from the horizontal plane, and the angle of the sunlight reflecting down a parallel walled tube. “TT” (degrees) refers to the tube taper, angle from vertical and/or parallel, while “ALT” (in degrees) refers to the alignment angle of light after reflecting off of the tapered wall. This angle is in relation to a horizontal plane. Then:
TT=((ALT)−(SALT))/0.2 and ALT=(2)(TT)+(SALT)
Present principles can be used to provide a single reflection, variable tapered tube that is optimally designed to realign sunlight while minimizing reflective material and space of the collimator.
In example embodiments and now referring to FIG. 3 , dimensions of the first (top) segment may be determined using the following equations:
DIATOP(inches)=Diameter of tapered tube at the top or light entrance;
DIATT(inches)=Diameter of tapered tube where light is reflected based on light entering the tapered tube from the top diameter at a specific SALT and light reflected at a specific ALT requirement;
HTTT(inches)=Height of tapered tube at the related DIATT; then
DIATT=(2)((DIATOP)(tan SALT))/((1/tan TT)−(tan SALT))+(DIATOP)
HTTT=(DIATT−DIATOP)/(2 tan TT) where “TT” is the angle of tube taper relative to the vertical axis.
Each consecutive segment diameter and height can be determined from the previous segments values as follows:
N is new value, P is previous value and AP is ½ the increase, in diameter from DIATOP to DIATTP. Thus using the example in the table below to determine HTTTN for the collimator @ a SALT of 35 degrees, AP would be (13.64−10.0)/2=1.82″.
HTTTN=((DIATOP+AP)(tan SALTN)−(HTTTP)(tan SALTN)(tan TTN))/1−(tan SALTN)(tan TTN)
DIATTN=DIATTP+(2)(HTTTN−HTTTP)(tan TTN)
Preferably, light undergoes only one reflection in the variable tapered tube to provide the required alignment angle.
With the above in mind, for a variable tapered tube that provides an alignment angle (ALT, the axis of the light spread as shown) greater than or equal to 55 degrees with an input range of light (SALT) from 15 degrees up to 55 degrees, the following dimensions may be used. The below table is in increments of ten degrees/five segments of (SALT). For this example, the top of the tapered tube opening is assumed to be ten inches in diameter. An example multiple stage collimator is shown in FIG. 4 .
SALT
TT
Tube Dia.
Tube height
15°
20°
12.16″
2.96″
25
15
13.64
5.51
35
10
14.91
8.72
45
5
15.81
12.90
55
0
16.04
18.59
The multiple stage collimator results in smaller dimensions than were a single stage collimator to be used with a taper angle of eight degrees to accomplish the same requirement. Such a single stage collimator would be expected to be fully one third-longer in axial dimension and six percent greater in diameter than the multi-stage collimator of equivalent performance.
In addition to saving space, use of a non-specular inside surface with controlled light spread in the present collimator can reduce glare and non-uniform illumination associated with using a specularly reflective surface. A non-specular surface provides, a controlled spread of light, less than approximately ten degrees, which eliminates the problems mentioned above, without unduly affecting the alignment angle since there is only one reflection.
It may now be appreciated that use of a multi-stage collimator changes the angle of low angle sunlight to a consistent high angle and, when a non-specular inside surface is used, with a minimum of glare. By maintaining relatively high angles to the diffuser/glazing independent of the solar altitude, consistent glazing efficiencies are maintained throughout the day. Furthermore, by establishing the downward angle of the sunlight and slightly spreading the light at the same time as described above, in some examples no diffuser need cover the open bottom end 38 of the collimator, simulating a recessed lighting fixture. Present principles also provide a consistent angular controlled light source for any light directing pendent or other optical element placed under the variable tapered tube.
A collimator assembly 100 may be provided as shown in FIG. 4 that has more than three stages and indeed may have a number of stages that approach the limit of infinity, i.e., each stage effectively has little or no thickness in the longitudinal dimension. Accordingly, the collimator 100 assumes a continuously curved shape in the longitudinal dimension as shown in FIG. 4 in which tangents 102 to the surface with respect to the longitudinal axis 104 of the collimator progressively define steeper angles from the collimator's light entry to the light exit. The equations above may be used at each axial location to establish the tangent at that location. The reflection angles and collimator dimensions shown in FIG. 4 are exemplary only and not limiting.
A collimator assembly 200 is shown in FIGS. 5-7 that has, from a round top opening 202 to a rectilinear bottom opening 204 , multiple collimator stages 206 , 208 , 210 , with the stages 206 - 210 being successively less flared than the next upper stage. Thus, the assembly 200 in FIGS. 5-7 is substantially identical to the collimators discussed above with the exception of the round to square configuration from top to bottom as shown. To achieve the round-to-square configuration, in which the top opening 202 may mate with the bottom of a cylindrical skylight tube while the bottom opening 204 may mate with a rectilinear diffuser or ceiling opening, the stages 206 - 210 transition progressively in the axial dimension from mostly round (the top stage 206 ) to predominantly rectilinear (bottom stage 210 ) as shown.
While the particular SKYLIGHT COLLIMATOR WITH MULTIPLE STAGES is herein shown and described in detail, it is to be understood that the subject matter which is encompassed by the present invention is limited only by the claims. | A non-specular skylight collimator has at least two axially successive collimator segments from top to bottom, with the segments becoming successively less flared from top to bottom. A skylight diffuser assembly typically covers the open end of the bottom segment. | 4 |
DESCRIPTION
BACKGROUND OF THE INVENTION
This invention relates to sewing machines, more particularly, to continuous pattern feed elongation in an electronically controlled sewing machine.
In heretofore known sewing machines utilizing a cam device and mechanical linkage to retain and transfer needle position information, it is possible to control the length of the pattern simply by adjusting the stitch length of the sewing machine. However, the amount of elongation possible was limited by the stitch length capability of the sewing machine. In certain sewing machines provision was made for adjustably controlling the rotational speed of the cam. Thus, the cam profile represented a continuous locii of points for needle position, bight and, in some cases, feed direction and rate, as opposed to discrete points on the cam profile representing needle position whenever the cam speed is a fixed ratio of the sewing machine speed. Thus, in these heretofore known mechanical sewing machines pattern elongation was possible merely by increasing the ratio between the sewing machine speed and the cam speed. Such a prior art sewing machine is disclosed in the U.S. Pat. No. 3,291,082 issued on Dec. 13, 1966.
With the advent of the electronically controlled sewing machine, stitch pattern information was retained in a solid state memory. Thus, the relationship of cam speed to sewing machine speed was lost. Normally, a position sensor sensitive to arm shaft rotation triggers the release of information from the solid state memory once during each stitch cycle. By including, in an electronically controlled sewing machine, a needle bar control assembly which permits discontinuing end-wise needle reciprocation while continuing with work feeding operations, pattern feed elongation may be obtained. Such a device is disclosed in U.S. Pat. No. 4,138,955, issued on Feb. 13, 1979 to Garron. In that patent, since a number of needle reciprocations could be discontinued, the pattern could be elongated by integral multiples depending upon the number of stitches skipped.
In the U.S. Pat. No. 4,016,821, issued on Apr. 12, 1977 to Minalga, there is disclosed means for controlling, among other things, the feed in an electronically controlled sewing machine so as to be able to reduce the stitch length derived from the information stored in the solid state memory. U.S. Pat. No. 4,177,744, issued Dec. 11, 1979 to Wurst et al, discloses a digital override control for bight and feed in a sewing machine whereby fixed fractions of the signal derived from the solid state memory may be transmitted to the feed actuator in order to attenuate the signal. The sewing machine disclosed in that patent also has the capability for doubling the feed. Thus, by actuating the digital overrides for feed to fractionate the feed signal derived from the solid state memory and by doubling feed cycle between stitches it is possible to attain pattern feed elongation in discrete steps from 0 to 2 times size. However, a smooth transition over that range is not likely because of the difficulty in selecting the proper digital override for feed multiplication to obtain a uniform change from minimum to maximum.
What is required is a device which will permit a sewing machine operator to readily obtain a uniform progression in pattern feed size from 0 to the maximum multiplication thereof.
SUMMARY OF THE INVENTION
The above ends are achieved in one embodiment including a potentiometer for electronic control of the feed, the potentiometer having arranged thereon, a cam for actuating a micro switch to enable the stitch multiplication while, simultaneously, reducing the gain in the linear amplifier controlling feed to one half. Thus, the override pot is rotated over half its scale to obtain full feed from the solid state memory, thereafter engaging the multiplication and reducing the gain on the feed buffer amplifier to one half of the previous gain.
A second embodiment is also disclosed in which the cam and micro switch are not utilized, but the override pot setting is determined in a comparator which may initiate switching the stitch multiplication, and reducing the gain on a feed buffer amplifier.
DESCRIPTION OF THE DRAWINGS
The foregoing will be more readily apparent upon reading the following description in conjunction with the drawings in which:
FIG. 1 is a front elevation of a sewing machine in which an arrangement constructed in accordance with the principles of this invention may be incorporated;
FIG. 2 is an elevation of the feed control knob shown in the sewing machine of FIG. 1;
FIG. 3 is a cross sectional view of the feed control knob shown in FIGS. 1 and 2 with the microswitch actuated thereby;
FIG. 4 is a circuit diagram indicating how a switch may be inserted in circuit to reduce the gain thereof;
FIG. 5 is a circuit diagram indicating how the function of the microswitch shown in FIG. 3 may be accomplished by a second circuit;
FIG. 6 is a front elevation of the prior art sewing machine indicating the digital overrides and the stitch multiplication capability which do not lend themselves to a smooth transition from 0 to maximum stitch; and,
FIG. 7A-D is a representation of some of the stitches obtainable in a sewing machine as shown in FIG. 1, indicating the stitch patterns obtainable with a 2X multiplication.
Referring now to FIG. 1, there is shown a sewing machine 10 in which this invention may be incorporated. The sewing machine 10 includes a bed 12 from which rises a standard 14 supporting a bracket arm 16 in overhanging relationship to the bed. The bracket arm 16 terminates in a head end 18 within which is supported an endwise reciprocatory needle bar 20 having a sewing needle 21 affixed to the end thereof. Also supported in the head end 18 behind the needle bar 20 is a presser bar 22 terminating in a presser foot 23, which presser foot urges work material against feed dogs (not shown) supported in the bed 12 of the sewing machine. The bracket arm 16 includes a control board 25 having a panel area 26 behind which there are indicia of the patterns and stitching capabilities of the sewing machine. The control board 25 further includes push buttons 28 for selecting individual patterns from a group of patterns, and further includes a group selector knob 30 for selecting the group from which the individual patterns may be selected.
Supported in the standard 14 is a second control module 32 including therein bight control knob 34, feed control knob 36 and balance control knob 38. For information on the operation of these knobs and their use the reader is referred to U.S. Pat. No. 4,016,821, which issued on Apr. 12, 1977 to Minalga, and which is assigned to the same assignee as the instant application and is hereby incorporated by reference herein. In that patent, it is disclosed that the bight and feed knobs are connected to rheostats which regulate the bypass resistance on buffer operational amplifiers to thereby control the gain of the analog signals derived from the solid state memory prior to transfer into servo amplifiers for regulating the position of the needle bar 20 and the direction and rate of the feed from a feed system supported in the bed 12. The balance control knob 38 is connected to a balance control potentiometer connected as a voltage divider to a double ended reference voltage, and connected only during reverse feed to vary the signal going into a feed servo amplifier so as to permit adjustment of reverse stitching to, for example, appear the same as forward stitching. In the above referenced application, it is taught that the feed control knob 36 when rotated over its entire range will vary the analog signal to the servo amplifier from a minimum value to a maximum equivalent to the digital signal stored in the solid state memory. However, in this invention, the feed control knob 36 is utilized to control feed in the sewing machine and additionally, to automatically actuate the multiplication factor so as to increase the feed rate uniformly from a minimum to the maximum multiplied feed. Thus, for a system in which it is desired to obtain pattern feed elongation of, for example, twice the maximum, the feed control knob 36 is arranged as is shown in FIG. 2. The control plate 40 behind the feed control knob 36 is marked with indicia 0 through 2 at the extremes of rotation of the feed control knob. Where the feed control knob 36 is turned to its minimum setting of 0, the signal derived from the solid state memory is completely attenuated so as to provide no feed. Where the feed control knob 36 is positioned as shown in FIG. 2, directed towards 1, the signal derived from the solid state memory is passed through without attenuation. Where the feed control knob 36 is directed toward the FIG. 2 on the control panel 40, multiplication of the feed length by a factor of 2 has taken place as disclosed in the prior referenced patent, by taking two feed steps while skipping one needle penetration.
FIGS. 3 and 4 indicate one embodiment in which a micro switch 42 is supported on and connected into a circuit board 48 on which the feed control potentiometer 50 is also supported. The micro switch 42 is fashioned with a spring loaded plunger 44 in contact with cam surface 54 which may be molded as part of the feed control knob 36. This cam surface, visible in FIGS. 2 and 3 is fashioned with a ramp portion 55 upon which the plunger 44 of the micro switch may initially impinge so as to be guided into its depressed position. The micro switch 42 is effective in its depressed position to activate the 2X multiplication disclosed in the above referenced patent and to change the gain of a buffer operational amplifier 60 shown in FIG. 4. The buffer operational amplifier 60 is interposed between the digital to analog conversion for the digital data from the solid state memory, and the servo system for the sewing machine. The analog signal derived from the solid state memory is transferred via line 62 to an override potentiometer 64. Line 66 takes the signal from the override potentiometer 64 and transfers the signal to the noninverting terminal of the buffer operational amplifier 60. The resistance 68 is in bypass configuration to the operational amplifier 60 and together with resistance 70 establishes a gain for the operational amplifier. These resistances 68, 70 are arranged to provide a gain of 2 to 1; however, when the switch 72 is closed, the gain is cut to 1 to 1. Simultaneously with the closing of the switch 72 the 2X capability is activated. Thus, when the feed control knob 36 is rotated from the indicia 0 to 1 inscribed upon control panel 40, the gain of the operational amplifier 60 is 2 to 1 so that the output therefrom to the servo system of the sewing machine varies from no signal to the full signal derived from the solid state memory. At the indicia 1 on the control panel 40 the feed control knob 36 actuates the micro switch 42 by initiating the release thereof, causing the electronics in the sewing machine to activate the 2X capability of the sewing machine and closing the switch 72 to cut the gain of the operational amplifier 60 to 1 to 1. Thereby, the output from the operational amplifier 60 is cut to one half and the needle bar 20 of the sewing machine penetrates the work material once for every two feeding cycles. As the feed control knob 36 is rotated further clockwise, the stitch length progressively increases from one half that achieved at a feed control knob setting of 1, until finally at a feed control knob setting of 2 the full feed achieved at a setting of 1 is implemented, but, needle penetrations occur once every two feeding cycles.
It can easily be appreciated that for pattern feed elongation of three times or four times or more, for the first half rotation of the feed control knob 36, the gain of the operational amplifier 60 may be the full multiplication desired. For the second half of the rotation of the feed control knob 36 the gain is one half of full multiplication desired and the 2X multiplication capability may be engaged. Thus, a continuous increase is obtained from zero to the full multiplication desired. Alternatively, a 4X multiplication capability may be utilized and the initial gain of the operational amplifier 60 for a 10X full multiplication may be 10 to 1 whereas the later gain may be 21/2 to 1 with a 4X multiplication capability implemented by having one stitch formed for 4 feeding cycles.
Referring now to FIG. 5, there is shown a second embodiment of a circuit which functions to replace the micro switch 42. In this circuit, resistors 74, 76 form a voltage divider which divides the input signal on line 78 in half. A comparator 80 is provided in which the signal from the half way point 82 is compared to the signal from the override pot 84. When the setting of the override pot 84 is beyond half way, the comparator 80 will switch, signalling the multiplication capability to begin skipping stitches so as to multiply feed, and cutting the gain of the operational amplifier 60.
In FIG. 6 there is shown a prior art sewing machine 90, in which the various capabilities and functions may be selected by touching the appropriate indicium on the control panel 92 thereof. Thus, for example, by touching the 2X indicium 94 this capability may be initiated. Similarly, by touching the indicium 96, the override capabilities for length, balance and width are implemented. The program length may be decreased by touching the arrow 98, and increased by touching the arrow 100. A digit 102 is displayed and may be varied over range of 0 to 9. It will be readily understood that in order to attain a uniform pattern elongation some juggling will be required in order to attain a uniform growth which is attained most readily by rotation of a dial in the invention. Where the multiplication capability is 3, 4, 5 or some other integer, achieving uniform feed growth is even more complicated.
Referring now to FIG. 7 there are shown some examples of the pattern feed elongation capability which may be easily implemented with the instant invention. This capability may be implemented for functional as well as aesthetic purposes in order to, for example, obtain better placement of functional zig zag stitches FIG. 7d, or when alternating loose and tight patterns for aesthetic reasons FIG. 7c. | An arrangement for obtaining pattern feed elongation in an electronically controlled sewing machine by utilizing a potentiometer for feed length variation, which potentiometer at a certain point switches in a feed multiplication and reduces its effectiveness so as to obtain a uniform change in feed from 0 to the maximum multiplication desired. Two embodiments are disclosed, one of which utilizes a comparator to eliminate a switch. | 3 |
AIM OF THE INVENTION
This descriptive report deals with a request for a Utility Model concerning an improved design for the fitting of sinks, the end of which lies in designing a medium capable of holding sinks, specifically, stainless steel sinks to be fitted flush with the worktop.
SCOPE OF THE INVENTION
This invention is be used in the industrial sector that deals in the manufacturing of stainless steel sinks and similar.
HISTORY OF THE INVENTION
As is well know, sinks that are to be flush-fitted aim at achieving a complete integration of the sink in question with the worktop, given that the surfaces of both the sink and the worktop are at the same level.
The applicant is familiar with some current media and designs for the fixing of flush-fitting sinks by the means of silicone and adhesive products that are applied at the bottom part of the perimeter of the sink, specifically at the bottom part of frame, which gives rise to the sink become housed in the staggering that is cut into the worktop surface.
There is evidence to suggest that the aforementioned media, which have been used to date, have certain disadvantages that may give rise to the moving of the sink itself, thus suggesting the convenience of using an additional element to solidly hold and fix the sink to the worktop; one which acts from below.
Nevertheless, the applicant is not aware of the fact that there is an invention which exists, and which possesses characteristics ideally suited to those mentioned above.
DESCRIPTION OF THE INVENTION
The improved design for the fixing of the sinks put forward by the invention contains a series of advantages which facilitate the fixing of the sinks whenever they are to be flush-fitted, enabling them to be fitted to worktops of varying degrees of thickness.
More specifically, the improved design to fix the sinks, which are the object of the invention, consists in the fitting, to the bottom part of the sink frame, of a winged projection positioned parallel to the bottom area of the frame, to which an oblong positioned U-shaped clamp is connected, from which a projecting hook emerges to which a winged projection screw emerging in the opposite direction, and which is positioned on the bottom part of the worktop, is connected.
By means of the simple action of a screwdriver, the lower screw gradually rises, thus giving rise to a gradual movement which implies, on the one hand, that the element on the bottom part is increasingly fixed to the under surface of the worktop, while, on the other hand, on the top part the U-shaped winged projection pulls the sink downwards vertically until achieving optimal fixing.
DESCRIPTION OF THE DRAWINGS
As a compliment to this description, and with the aim in mind of facilitating a greater understanding of the characteristics of the invention, accompanying this descriptive report, and forming an integral part of the same, there is a sheet of drawings on which, for the purposes of illustration, though not purporting to be comprehensive, the following has been represented:
FIG. 1 —This shows a raised side view of the object of the invention, which is concerned with an improved design for the fixing of sinks.
PREFERENTIAL REALIZATION OF THE INVENTION
With the aid of sole FIG. 1, it can be seen how the improved design for the fixing of sinks is made up of the fitting to the side of the sink ( 1 ) parallel to the frame of the sink ( 2 ) of a winged projection ( 3 ), made from the same material and forming a single-blocked body with the frame ( 2 ) and the sink.
This winged projection ( 3 ) is positioned parallel to the frame ( 2 ) at its bottom part, and has an oblong part ( 5 ), which is U-shaped, connected to it, which implies that when this part is moved by means of the action of the lower screw ( 4 ) it is gradually pulled downwards vertically, while the screw acts by moving itself vertically downwards, and pulling at the same time a winged projection ( 6 ) which is gradually fixed to the underside of the workshop ( 10 ).
In this way, the duly flush-fitted sink, which, as can be seen from the figure is flush with the top surface of the worktop ( 10 ), is fixed at its bottom part by means of the action of the fixing element on the winged design ( 3 ), which is the part that gives rise to the shifting of the fixation element at the bottom. | An improved means to position and secure a sink which is flush mounted with the worktop. It is designed to be used with sinks of variable thickness and materials including stainless steel. | 4 |
RIGHTS OF THE GOVERNMENT
The invention described herein may be manufactured and used by or for the Government of the United States for all governmental purposes without the payment of any royalty.
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation of application Ser. No. 720,468, filed Sept. 3, 1976, now abandoned.
BACKGROUND OF THE INVENTION
The field of the invention is in the art of firearms and more particularly in the art of adapters to provide for the firing of conventional low power ammunition in a gun originally designed for higher power cartridges.
The economic and psychological advantages of training, practicing, and the taking of small game with low power ammunition in a gun conventionally designed for higher power ammunition is well recognized. Adapter "cartridges", sometimes called auxilliary cartridges, for containing the low power round and fitting the chamber of the high power gun have been known since before the turn of the century. A conversion adapter for the Government model .45 caliber ACP converting it to fire .22 caliber rimfire cartridges has been available since prior to World War II. That conversion required a new barrel since the calibers of the bullets were different. The invention disclosed herein does not require any change of barrels since the bullet diameters of the original high power cartridge and the conversion low power cartridge are substantially the same.
Typical examples of modern prior art devices are exemplified by U.S. Pat. No. 3,771,415 to patentees Into and Costello, and U.S. Pat. No. 3,776,095 to patentee Atchisson. A review entitled "AR-15 Rimfire Conversion", by the Technical Staff of the National Rifle Association appearing in the American Rifleman for May 1973 commencing at page 63, is pertinent and informative of problems in the prior art devices.
SUMMARY OF THE INVENTION
The invention is an improved, highly reliable, universally fitting, adapter system for a high power .22 caliber rifle providing for the firing of conventional, economical, .22 caliber, rimfire ammunition. The malfunction rate is greatly improved (reduced) over the prior art devices, by having the adapter chamber land-and-grooved ahead of the .22 caliber rimfire chamber in the gun chamber adapter and by an improved extraction system. A unique gas diverter protects the rifleman's eyes and keeps the action clean providing for the firing of a greater number of rounds between cleaning, and a unique double spring operated bolt catch actuating mechanism in the .22 caliber rimfire adapter magazine maintains the breech open after firing the last round from the magazine adapter.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 illustrates a typical prior art high power .22 caliber rifle such as the M16 and AR-15;
FIG. 2 illustrates, schematically, a side elevational view, partly in cross section, of an embodiment of the adapter system of the invention positioned in a rifle with the bolt in battery position and the hammer cocked;
FIG. 3 represents the same action and gun of FIG. 2 except the bolt is at the feed position;
FIG. 4 is a representative view of an embodiment of the unitary slidable bolt and chamber adapter assembly of the invention;
FIG. 5 is a right end view of FIG. 4;
FIG. 6 is a top view of FIG. 4;
FIG. 7 is a section taken through the bolt of FIG. 6;
FIG. 8 is a left end view of FIG. 4;
FIG. 9 is an enlarged view of an embodiment of a typical bolt assembly;
FIG. 10 is a right end view of FIG. 9 showing the bolt face;
FIG. 11 is a partial section of the bolt face of FIG. 10 showing the undercut cartridge rim retainer;
FIG. 12 is an enlarged view of the chamber adapter shown in FIGS. 4 and 6;
FIG. 13 is a right end view of the chamber adapter illustrated in FIG. 12;
FIG. 14 is a left end view of the chamber adapter illustrated in FIG. 12;
FIG. 15 is a longitudinal section view through the chamber adapter as shown in FIG. 14;
FIG. 16 is a transverse section through the chamber adapter shown in FIG. 12 illustrating the lands and grooves;
FIG. 17 is a longitudinal section view similar to FIG. 15 except of a chamber adapter for firing blank cartridges;
FIG. 18 is a pictorial left side view of a typical embodiment of a magazine adapter;
FIG. 19 is a right side view of the magazine of FIG. 18 with the cover removed;
FIG. 20 is a rear view of the magazine of FIG. 18;
FIG. 21 is a partial section view through the retaining pin as shown in FIG. 20;
FIG. 22 is a view of an embodiment of a typical magazine follower for the embodiments of magazine as illustrated in FIGS. 18 through 21;
FIG. 23 is an enlarged left side view of FIG. 22;
FIG. 24 is an enlarged pictorial front view of typical feed lips of the magazine;
FIG. 25 is a right side view of typical magazine feed lips;
FIG. 26 is a rear view of typical magazine feed lips;
FIG. 27 illustrates another embodiment of a magazine adapter showing the cooperation with a conventional .22 caliber rimfire prior art magazine.
FIG. 28 illustrates a typical prior art .22 caliber rimfire magazine;
FIG. 29 is a top view looking down on the embodiment of the magazine adapter, (without the conventional .22 caliber rimfire magazine in place) illustrated in FIG. 27;
FIG. 30 is a left side view of another embodiment of a magazine adapter having a side actuated lever cooperating with the bolt catch;
FIG. 31 is a rear view of the magazine illustrated in FIG. 30; and
FIG. 32 is a left side view of the follower of the magazine illustrated in FIG. 30.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a typical rifle of the military type M16 and the commercial type AR-15. This rifle has a nominal .22 caliber bore. Many guns are of .22 caliber, with chambering ranging from the very small and very low power rimfire .22 caliber CB and BB caps to the ultra high power cartridges such as the .220 Swift and the .22-250 cartridges. The most common and widely manufactured .22 caliber ammunition is the rimfire cartridges commonly known as the 22 short, the 22 long, and the 22 long rifle cartridges. The 22 long rifle cartridge is a highly developed cartridge that is economical, readily available, and a very accurate cartridge that is used in official target matches throughout the world including the Olympics.
The device of the invention adapts the conventional M16, AR-15 and similar types of rifles, conventionally chambered for .22 caliber cartridges such as the .223 cartridge, a relatively high power .22 caliber cartridge, to fire in semiautomatic mode .22 caliber rimfire long rifle ammunition. In the training of an individual in a typical standard military training course this represents a $1.50 ammunition expense compared to a $13.50 ammunition expense, a 9 to 1 monetary saving in ammunition. The typical conventional rifle as shown in FIG. 1 has a bolt that is gas operated by diverting gas pressure from the barrel through gas tube 50 back to the action in the receiver to operate the bolt. In embodiments of the invention the new adapter bolt operates by conventional "blow-back" action only. The small amount of gas from the low power round coming back down tube 50 has expanded, due to the volume of the tube, to the extent that its pressure is insignificant. However, there is sufficient gas flow down the tube to bring burnt powder particles and other gaseous residues back into the action. Some prior art adapters have ignored this material with the consequences of a dirty unreliable action after the firing of a relative few rounds. Other prior art systems have required the modification of the standard arm by the sealing off or closing of the gas tube. This prohibits the field installation of the conversion adapter and the field reconversion to the standard arm. In the following discussion of the operation of the adapter reference should be made to FIGS. 2 through 17.
The gas diverter 51 on the adapter engages and surrounds the end of gas tube 50 when bolt 52 is in the battery position, as shown in FIG. 2. Gaseous and burned powder residues from the firing of a round of ammunition coming down gas tube 50 travel through gas diverter 51 and are expelled through ports 53 and 54 out of the action and exterior to the mechanism in a transverse downward direction. This expulsion of gas occurs in the operation of the action before the bolt has moved back sufficiently to disengage or uncover the end of gas tube 50.
Hammer 55 is cocked by the sliding rearward travel of bolt 52 on the guide rails. With good ammunition bolt 52 slides rearwardly on guide rails 56 and 57, cocking hammer 55, and then striking buffer 58, which absorbs the remaining energy in the bolt with a minimum of shock to the mechanism. Typical buffer material is polyurethane rubber having a Shore A Durometer of approximately 95. Guide rail 57 is a round rod contained within and supporting action spring 59. Action spring 59 then returns bolt 52 to the battery position picking up a new round of ammunition 60 as illustrated in FIG. 3. Upon squeezing trigger 61 with the bolt in the battery position, as shown in FIG. 2, hammer 55 is released from sear notch 62 and by the force of the hammer spring (not shown) the hammer striking inertia firing pin 63 firing new round 64 in chamber adapter 65.
Upon firing a round the spent rimfire case, after initial movement, is withdrawn from the rimfire chamber within gun chamber adapter 65 by conventional spring loaded extractor lever 70 cooperating with undercut recess 71 in the case rim retainer on bolt face 72. (See FIGS. 10 and 11.) It has been found that an optimum angle 73 of undercut measured from perpendicular 74 to bolt face 72 is approximately twenty degrees, with a variation of approximately plus or minus two degrees still providing suitable operation. The depth of the recess in the bolt face receiving the case rim, is the conventional value of nominal cartridge rim thickness. As bolt 52 travels rearward by blowback action the spent case is withdrawn from the chamber and held on the bolt face by extractor 70 and recessed rim retainer 71 until the rim of the case strikes ejector 75, mounted on guide rail 56, which ejects the spent case out ejection port 76 (FIG. 1) of the gun. It is to be observed that bolt 52 cocks hammer 55 before reaching the feed position, thus a live round cannot be chambered without cocking the gun.
As previously stated, adaptors for these type guns are currently available. The primary purpose and object of this invention is to provide an improved adaptor that will reliably function (i.e., to accurately fire in conventional semiautomatic mode) in a larger percentage of guns, compensating within the adapter itself for wide variations in manufacturing tolerances and gun design dimensions, and an adapter that is not sensitive to wide variations in ammunition, both good and poor ammunition in both high speed and regular velocities. Poor ammunition not only includes poorly manufactured ammunition such as ammunition with wide variations in the amount of bullet crimp but ammunition that has been abused in storage by detrimental environmental changes to the extent that the primer or the powder or both have changed characteristics, or the bullet through excessive oxidation has loosened in the case.
Using a typical embodiment of the invention and a particular batch of typically poor ammunition, the malfunction rate was consistently around 1/2 percent. With currently available prior art adapters and ammunition from the same batch the malfunction rate varied from 4 to 8 percent.
Through a unique cooperation of a combination of unique modifications and structural innovations a greatly improved adapter system is hereby disclosed. The providing of gas diverter structure 51 for safety and to keep the action clean and extend periods of operation between cleaning, has been discussed. For accurate and reliable operation it is required that adapter chamber 65 be firmly positioned and seated in the chamber of the gun. In many guns the chamber in the barrel is not in perfect alignment with the direction of travel of the adapter bolt. With prior art adapter devices, this has frequently prohibited their usage in certain guns and greatly decreased their reliability of operation in others with satisfactory operation being obtained in a "good" gun with "good" ammunition. In these prior art devices, the chamber adapter, and the rear retainer have been rigidly attached to one or both the bolt guide rails. In this invention chamber adapter 65 is loosely pinned to guide rail 56 by one pin only through hole 80. The pin is a loose fit in rail 56 and the rail is likewise a loose fit in notch 78 of chamber adapter 65. (See particularly FIG. 13.) Guide rod 57 also is a loose fit in hole 81, has a rounded end 82, and extends only a little more than halfway through hole 81 (see FIG. 4). This provides a chamber adapter 65 that can swing approximately up to plus and minus five degrees 98 in the horizontal direction, a plane approximately containing guide rail 56 and rod 57, and approximately up to plus and minus two degrees 83 in the vertical direction. This flexibility of the slidable movement of the bolt with the chamber alignment greatly increases the number of guns that the adapter will fit and properly function therein.
It is important that the chamber adapter be firmly seated and positioned in the chamber of the gun so as to effect a substantially gas tight seal between taper 84 of the adapter chamber and shoulder 85 in the chamber of the barrel. The flexible mounting of the adapter chamber on the guide rail and rod helps accomplish this in poorly aligned guns. However, the length of the receivers of the guns also vary due to necessary manufacturing tolerances. Therefore, the distance from chamber shoulder 85 (FIG. 2) in the gun barrel (on which adapter taper 84, FIG. 4, seats) and lower receiver extension socket 86, through which recoil is taken in conventional M16 operation, and on which forward locator 87 of rear retainer 88 bears, may vary considerably between different guns and different guns of different manufacture. Forward locator 87 is spring loaded by spring 89, as illustrated in FIG. 4. Thus, even though receiver lengths between various guns may vary as much as eighty thousandths of an inch, taper 84 of the adapter chamber is always firmly seated and maintained in sealing relationship with chamber shoulder 85 in the rifle barrel. This firm positioning of the adapter mechanism in all guns is also very important for proper relationship between the feed ramp 118 within the lips 104 of the magazine and feed ramp 119 in chamber adapter 65 to prevent malfunctioning and jamming of the round during feeding. This is automatically accomplished with the insertion of the adapter in the gun without any manual adjustment or fitting. This spring loading of the adapter mechanism coupled with the flexible connection of the adapter chamber provides a universal mounting of the adapter of this invention such that proper operation is obtained in many more weapons than could be obtained with prior art devices. Some of the prior art adapters have a neck on the adapter chamber. I have found the necessarily thin walled neck to be an unnecessary complication, greatly adding to the fragility of the adapter, and in some instances it is detrimental to obtaining a seal between the taper of the adapter and the shoulder of the chamber.
Some small arms have bolts with double lever arm extractors to provide a more reliable operating arm than those having but a single hooked lever arm extractor. The conventional single extractor bolt has a conventional straight walled cartridge rim receiving recess in its face in which the cartridge rim rests. In conventional single lever case extraction, occasionally the case slips out from under the extractor hook and a jam results. This is conventionally remedied by having two extractor arms placed substantially opposite each other across the case, each extractor gripping the rim of the case. Double extractors are expensive and provide additional complications in case ejection. I have found that substantially the reliability of double lever extraction may be obtained with a single extractor lever arm by providing an undercut 71 in approximately a 90° segment of the case rim retainer approximately opposite the hooked extractor lever arm 70 as shown in FIGS. 10 and 11, and as previously explained in connection with the operation of the bolt.
Commercially available prior art adapters do not have rifling in bore 90 of adapter chamber 65 ahead of low power cartridge case chamber 91 (FIG. 15). I have found that one of the primary causes of malfunctioning of prior art adapters is due to slow ignition, i.e., low initial burning rate of the powder not providing sufficient blow-back on the bolt to operate the action. I have also found that the primary reason for these low pressures on the bolt is caused by defective crimping of the case neck on the bullet allowing the bullet projectile to leave the case and start down the smooth bore passageway of the prior art adapters before complete ignition of the powder from the primer flash has taken place. The smooth bore of the prior art chambers necessarily is larger than the bullet diameter so it does not provide a sufficient seal to the bullet to hold back the gases and provide combustion pressure buildup. Thus, complete combustion of the powder either does not occur or else if it does, it occurs at a slower rate so normal blow-back pressures are never developed. While poor crimping of the case to the bullet is the primary cause of this type of malfunction, other causes such as poor or defective powder or primers, or mechanically damaged rounds, will also cause a low pressure initial powder burn due to the bullet leaving the case and the powder then burning substantially in an unconfined condition. The diameter of bore 90 of adapter chamber 65 cannot be made so small as to never be larger than the minimum tolerance diameter of the manufactured bullets to effect a seal because with bullets going to the large tolerance diameter and the bore going to the small end of its tolerance a severe interference fit between the bullet and the bore would occur with no place for the lead of the bullet to go other than through elongation of the bullet. This would cause extremely high pressures, be detrimental to the action and result in very inaccurate fire. I have found that by providing lands 92 and grooves 93, as shown in section in FIG. 16, in bore 90 of adapter chamber 65 ahead of rimfire case chamber 91, a simple efficient, and economical seal of the bore to the bullet is obtained. This seal provides for much better (higher and more uniform) pressure buildup with poor ammunition and a great decrease in the number of gun malfunctions, particularly with poor ammunition. It is not necessary that the lands and grooves in the bore of the adapter constitute rifling, i.e., have a twist or spiral. Neither is it necessary that the number of lands and grooves in the adapter be the same number as are in the barrel of the rifle, nor is any alignment of the lands and grooves of the adapter with those of the rifle barrel necessary. It is important to effect a good seal that the rifling engage the bullet before it completely leaves the cartridge case. I have found that optimally the length of the rimfire chamber 91 from the face of chamber 96 to the start of rifling 97 should be approximately 0.735±0.005 for use with standard commercial makes of .22 caliber long rifle ammunition. This assures a seal by case expansion and the upsetting of the base of the bullet. If the lands and grooves in the adapter are in the form of rifling it is generally desirable that the twist be in the same direction as the rifling in the barrel and at approximately the same rate of twist. Generally, it is most economical to use the same tools and techniques in placing the lands and grooves in the adapter as the rifling in the gun barrel, hence, it is generally preferable to rifle the adapter similarly to that of the gun in which it is to be used. In many instances, it may be most feasible, economically, to fabricate an adapter chamber from a section of rifled barrel blank material. Typically, for rifles of the M16 type, six grooves, right hand one turn in approximately twelve inches, with the diameter across grooves approximately 0.2235±0.0010 and across lands 0.219±0.0010, and a groove arc of approximately 40° 30', is suitable. In many instances, more uniform velocities may be obtained by using standard .22 caliber rimfire barrel rifling for adapter fabrication.
It is frequently desirable, particularly in military usage to fire blank cartridges in semiautomatic fire that are not as loud and more economical than blank cartridges of the size for which the gun was originally designed. By simply substituting adapter chamber 65a as shown in cross section in FIG. 17 in place of adapter chamber 65 blank rounds of ammunition of similar case design may be fired in the semiautomatic mode. The dimensions of orifice 95 are a function of the characteristics of the blank cartridge to be fired. Typically, for conventional .22 caliber rimfire blank cartridges, an orifice port 95 having a 0.062 inch diameter ±0.001 inch has been found to be suitable. For conventional 5.56 ram set cartridges (a nominal .22 caliber rimfire blank cartridge (expressed metrically) that is used in construction to drive nails), an orifice diameter of 0.092±0.001 inch opening has been found to be suitable. The length of tubular passage 95 is not critical. For other .22 caliber rimfire blank cartridges the diameter of the orifice is correspondingly increased or decreased in accordance with the powder charge contained. Generally, suitable lengths of passageway are approximately 1/8 inch. Obviously, the wall thickness at the end of the blank chamber adapter should be of sufficient thickness to withstand the pressures developed by the blank cartridge.
A typical embodiment of a magazine adapter cooperating with the just described bolt and chamber adapter for rifles of the M16 type is shown in detail in FIGS. 18 through 26, and in position in the gun in FIGS. 2 and 3. Magazine adapters for use with chamber and bolt adapters for converting the fire of a high powered rifle to lower power are well known. Typical prior art magazine adapters for converting the ammunition feed to a rifle from a caliber such as the .223 to .22 long rifle rimfire caliber are disclosed in the patents previously referenced. The embodiment of magazine adapter 100 as illustrated in FIGS. 2, 3, 18, 19, and 20 feeds the .22 caliber long rifle rimfire rounds through containing passageway 101 by spring (102) actuated follower 103 to conventionally designed feed lips 104. Protruding bolt feed lug 105 (FIGS. 7 and 10) on the bottom of bolt 52 engages the rear of the uppermost round 60 (FIG. 3) in the magazine as bolt 52 passes over magazine lips 104 returning to battery and chambering the round. The magazine adapter is manually loaded with .22 caliber rimfire cartridges in the conventional manner of feeding the cartridges, one at a time, through lips 104 with one hand while adapter 100 is held by the other hand with the thumb of that hand assisting in the compression of the follower spring 102 by pressing on protruding lug 106 of follower 103 (FIGS. 19 and 22).
When using the rifle in the conventional manner with standard .223 high power cartridges when the magazine is emptied and after the bolt has recoiled from firing the last round from the magazine, the magazine follower by it spring, pushes up on bolt catch lever 107 (FIGS. 2 and 3) and moves it so as to engage the returning bolt and hold it back, thus, automatically maintaining the action open after firing the last round. The prior art low power magazine adapters do not have this very desirable safety feature. When using the known prior art adapter systems the bolt can only be held back so as to maintain the action open by manually actuating bolt catch lever 107 from its protruding lug on the left side exterior receiver surface. In the prior art devices, after firing the last round from a magazine the bolt closes on an empty chamber, and the rifleman has no indication that the chamber is empty until he squeezes the trigger and the gun doesn't fire. In the disclosed invention, the bolt catch lever 107 is automatically actuated by the magazine adapter to hold the bolt back, and maintain the action open after the firing of the last round. This operation occurs through the unique cooperation of forces from magazine follower spring 102 and lifter spring 110 both pressing upwardly on bolt stop plunger 111 after the firing of the last round from the magazine and the magazine is empty.
It is to be observed that metallic guide 112, which is conventionally attached (such as riveted) to follower 103 (see FIGS. 19, 22, and 23) assists lifter spring 110 in actuating bolt step plunger 111 only when magazine 100 is empty. The combined forces of lifter spring 110 and magazine spring 102 pressing upwardly on plunger 111 are sufficient to move bolt catch lever 107 upward so that it engages the returning bolt and holds it back. Bolt catch lever 107 may also, of course, be manually operated from the left side of the receiver in the normal manner. Lifter spring 110 acting alone on plunger 111 must not be strong enough to move bolt catch lever 107. In this unique double spring arrangement magazine follower spring 102 is of normal strength for .22 rimfire ammunition. To fabricate a magazine adapter in which the magazine follower spring alone actuates bolt catch lever 107, i.e., a spring as strong as in the conventional high powered .223 caliber magazine, would require a spring too strong to permit proper feeding of .22 caliber rimfire cases. It would also increase the loading effort required to load the magazine. Rivet 113, acting in a cutout in shaft plunger 111, serves as a retaining stop for the plunger. In addition, rivet 113 aids in securing feed lips 104 to magazine body 100. In the view shown in FIG. 19 magazine cover plate 115 has been removed from magazine body 100 to show slot 116 in which lip 117 of guide 112 moves. The cover is in place in the views shown in FIGS. 2 and 3. Typical and suitable materials from which to fabricate magazine body 100, cover 115, and follower 103 is Delron or Celcon Acetal plastic. The feed lips are conventionally fabricated from steel and tempered to provide the desired spring action. Plunger 111 is conventionally machined from suitable tool steel. Conventional recess 120 and boss 121 cooperate with the conventional magazine latch in the receiver of the rifle.
Another embodiment of an adapter magazine is illustrated in FIGS. 27 and 29. This embodiment is fabricated to cooperate with conventional unmodified, prior art commercially available .22 caliber long rifle rimfire magazines such as the Smith and Wesson Model 41 as illustrated in FIG. 28. Body 130 of the adapter is fabricated of similar material, and like the previously described embodiment, to be of substantially the same size and shape as the conventional .223 caliber magazine, so as to function with the rifle. Commercially available magazine 131 has thumb button 132 and slightly protruding actuating and stop lug 133 attached to magazine follower 134. Magazine adapter case 130 has a pivoted, spring loaded, steel lever arm 135 with bolt catch actuating lip 136. lip 136 moves rifle bolt catch 107 to hold the action open after firing the last round from the magazine. Lever assist lifter spring 137 acts in combination with the commercial magazine follower spring (not shown) in magazine 131 to overcome the spring force on the bolt catch in the gun, in a manner similar to the double spring action of the previously described magazine adapter. Protruding lug 133 of conventional prior art magazine follower 134 engages turned down lip 138 of actuating arm 135 only after the last round has been chambered from the magazine. Spring loaded magazine latch 139 holds prior art magazine 131 in adapter case 130 yet provides easy insertion and removal of magazine 131 for loading. As in the previously described embodiment of a magazine adapter, spring 137 should not be strong enough to trip the bolt catch yet strong enough so that when its force is combined with the force from the magazine follower spring the bolt catch lever will be actuated.
Another embodiment of a magazine adapter is illustrated in FIGS. 30 and 31. It is similar to the previously described magazine adapter, illustrated in FIGS. 18, 19, and 20, except for the bolt catch actuating mechanism. Metallic lever arm 150 is conventionally pivoted at 151. Magazine follower 152 has integrally molded lug 153 (opposite the thumb lug) which bears on lever arm 150 so that the follower spring (not shown) is coupled with the lever arm lifter spring 154 after the last round has left the magazine. Their combined force acting on lip 155 is sufficient to actuate the bolt catch of the gun. Outwardly turned lip 156 of lever arm 150 functions in cooperation with the cutout in the case side to provide a limit of travel stop for the movement of the arm. Recess 157 in case 160 provides clearance for the movement of actuating lug 153.
It is to be understood that while the magazine adapters illustrated herein are nominal ten-round magazine adapters, the invention is just as applicable to magazines of different cartridge capacity. | A unitary bolt and chamber adapter for field replacement, without tools, of the conventional bolt assembly of rifles of the type M16 and AR-15 provides for the use of conventional .22 caliber long rifle rimfire ammunition in the rifle instead of the larger conventional centerfire ammunition. The bolt functions in semiautomatic fire by conventional blowback action. Through cooperation with an improved .22 caliber rimfire magazine adapter, the breech automatically remains open after firing the last round from the magazine. The bolt guide rails are flexibly attached to the chamber providing for reliable operation in a larger number of rifles. A spring actuated forward locator on the bolt assembly keeps the adapter seated in the rifle chamber, compensating for differences in gun receiver lengths. An undercut bolt face provides the positive extraction of a double extractor system with a single extractor, and a groove-and-land chamber adapter provides reliable operation with good and poor quality ammunition. A gas diverter protects the rifleman's eyes and provides a clean receiver without modifying the original gun. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application Ser. No. 10/666,998 filed Sep. 19, 2003, which claims the benefit of U.S. Provisional Application No. 60/412,215 filed Sep. 20, 2002, both of which are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
[0002] This invention pertains to anthraquinone compositions that are useful as broad-spectrum quenchers of fluorescence and to methods for making and using them. The invention also provides kits that contain at least one of the disclosed anthraquinone quencher dye compositions.
BACKGROUND OF THE INVENTION
[0003] Chemical moieties that quench fluorescent light operate through a variety of mechanisms, including fluorescence resonance energy transfer (FRET) processes and ground state quenching. FRET is one of the most common mechanisms of fluorescent quenching and can occur when the emission spectrum of the fluorescent donor overlaps the absorbance spectrum of the quencher and when the donor and quencher are within a sufficient distance known as the Forster distance. The energy absorbed by a quencher can subsequently be released through a variety of mechanisms depending upon the chemical nature of the quencher. Captured energy can be released through fluorescence or through nonfluorescent mechanisms, including charge transfer and collisional mechanisms, or a combination of such mechanisms. When a quencher releases captured energy through nonfluorescent mechanisms FRET is simply observed as a reduction in the fluorescent emission of the fluorescent donor.
[0004] Although FRET is the most common mechanism for quenching, any combination of molecular orientation and spectral coincidence that results in quenching is a useful mechanism for quenching by the compounds of the present invention. For example, ground-state quenching can occur in the absence of spectral overlap if the fluorophore and quencher are sufficiently close together to form a ground state complex.
[0005] Quenching processes that rely on the interaction of two dyes as their spatial relationship changes can be used conveniently to detect and/or identify nucleotide sequences and other biological phenomena. For example, the change in fluorescence of the fluorescent donor or quencher can be monitored as two oligonucleotides (one containing a donor and one containing a quencher) bind to each other through hybridization. Advantageously, the binding can be detected without separating the unhybridized from the hybridized oligonucleotides.
[0006] Alternatively, a donor and quencher can be linked to a single oligonucleotide such that there is a detectable difference in fluorescence when the oligonucleotide is unhybridized as compared to when it is hybridized to its complementary sequence. For example, a self-complementary oligonucleotide designed to form a hairpin can be labeled with a fluorescent donor at one end and a quencher at the other end. Intramolecular annealing can bring the donor and quencher into sufficient proximity for FRET and fluorescence quenching occurs. Intermolecular annealing of such an oligonucleotide to a target sequence disrupts the hairpin, thereby increasing the distance between the donor and quencher, and resulting in an increase in the fluorescent signal of the donor.
[0007] Oligonucleotides labeled in a similar manner can also be used to monitor the kinetics of PCR amplification. In one version of this method the oligonucleotides are designed to hybridize to the 3′ side (“downstream”) of an amplification primer so that the 5′-3′ exonuclease activity of a polymerase digests the 5′ end of the probe and cleaves off a dye (either the donor fluorophore or quencher) from that end. The fluorescence intensity of the sample increases and can be monitored as the probe is digested during the course of amplification.
[0008] Similar oligonucleotide compositions find use in other molecular/cellular biology and diagnostic assays, such as in end-point PCR, in situ hybridizations, in vivo DNA and RNA species detection, single nucleotide polymorphism (SNPs) analysis, enzyme assays, and in vivo and in vitro whole cell assays.
[0009] As noted previously, the energy transfer process requires overlap between the emission spectrum of the fluorescent donor and the absorbance spectrum of the quencher. This complicates the design of probes because not all potential quencher/donor pairs can be used. For example, the quencher BHQ-1, which maximally absorbs light in the wavelength range of about 500-550 nm, can quench the fluorescent light emitted from the fluorophore fluorescein, which has a wavelength of about 520 nm. In contrast, the quencher BHQ-3, which maximally absorbs light in the wavelength range of about 650-700 nm would be less effective at quenching the fluorescence of fluorescein but would be quite effective at quenching the fluorescence of the fluorophore Cy5 which fluoresces at about 670 nm. The use of varied quenchers complicates assay development because the purification of a given probe can vary greatly depending on the nature of the quencher attached.
[0010] Many quenchers emit energy through fluorescence reducing the signal to noise ratio of the probes that contain them and the sensitivity of assays that utilize them. Such quenchers interfere with the use of fluorophores that fluoresce at similar wavelength ranges. This limits the number of fluorophores that can be used with such quenchers thereby limiting their usefulness for multiplexed assays which rely on the use of distinct fluorophores in distinct probes that all contain a single quencher.
[0011] Thus, new compositions are needed that quench fluorescence over a broad spectrum of wavelengths such that a single quencher can be used with a broad range of fluorophores. Ideally, such quenchers will not fluoresce so that the background fluorescence of probes is minimized giving such probes the potential to be more sensitive and more useful in multiplexed assays. The ideal quenchers should also have physical properties that facilitate their purification and the purification of probes into which they are incorporated. Such quenchers should also be chemically stable so that they can be incorporated into biological probes and used in assays without significant degradation. Ideally, such probes will be suitable for direct use in the synthesis of DNA oligomers so that oligonucleotides can be synthesized to contain them, as opposed to chemically adding the quencher to an oligonucleotide postsynthetically. Nevertheless, the quenchers should contain suitable reactive moieties to provide for their convenient incorporation into biologically relevant compounds such as lipids, nucleic acids, polypeptides, and more specifically antigens, steroids, vitamins, drugs, haptens, metabolites, toxins, environmental pollutants, amino acids, peptides, proteins, nucleotides, oligonucleotides, polynucleotides, carbohydrates, and the like. Lastly, the most useful compositions should be easily manufactured.
[0012] The invention provides nonfluorescing compositions with strong fluorescence quenching properties that function over a surprisingly wide wavelength range. Consequently, the disclosed compositions exhibit lower fluorescent backgrounds than quenchers that quench light at certain wavelengths and emit fluorescence at nearby wavelengths. Moreover, the anthraquinone quenchers of the present invention can be easily manufactured and purified. The compositions can be incorporated into biologically relevant compounds and, in many cases, impart useful purification properties to these compounds. These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.
BRIEF SUMMARY OF THE INVENTION
[0013] The invention provides novel anthraquinone compositions that are useful as broad-spectrum quenchers of fluorescence and methods for making and using them. The anthraquinone quenchers can be conjugated to a variety of biologically relevant compounds, including lipids, nucleic acids, polypeptides, and more specifically antigens, steroids, vitamins, drugs, haptens, metabolites, toxins, environmental pollutants, amino acids, peptides, proteins, nucleotides, oligonucleotides, polynucleotides, carbohydrates, and their analogs. The invention also provides kits comprising, in one or more containers, at least one anthraquinone quencher dye composition of the present invention, and instructions for using that composition.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 shows the absorbance spectra of identical 12 nucleotide long oligonucleotides that contain quenchers conjugated to the 3′ end. Oligonucleotides containing the anthraquinone quencher UQ2 (SEQ ID No: 1), and the quenchers QSY7 (SEQ ID No: 2), and Dabcyl (SEQ ID No: 3) were synthesized as described in Example 16.
[0015] FIG. 2 shows fluorescence curves plotted as a function of PCR cycle wherein oligonucleotide probes contained a conjugated 6-carboxyfluorescein (6FAM) reporter dye and various quenchers. Fluorescence-quenched probes with 1-(phenylamino)-4(2-hydroxy-ethylamino)-anthraquinone (UQ2) (SEQ ID No: 4), 6-carboxytetramethylrhodamine (6Tamra) (SEQ ID No: 5), and N,N′-dimethyl-N,N′-diphenyl-4-((5-t-butoxyca rbonylaminopentyl)aminocarbonyl) piperidinylsulfonerhodamine (QSY7) (SEQ ID No: 6) were compared in reactions containing about 10.sup.3 target DNA molecules. The log of relative fluorescence units (Y-axis) are plotted against PCR cycle number (X-axis). The curves are indistinguishable and are not individually labeled.
[0016] FIG. 3 shows fluorescence curves which were generated using 1H, 5H, 11H, 15H-Xantheno[2,3,4-ij:5,6,7-i′j′]diquinolizin-18-ium, 9-[2(or 4)-[[[6-[2,5-dioxo-1-pyrrolidinyl)ozy]-6-oxohexyl]amino]sulfonyl]-4(or 2)-sulfophenyl]-2,3,6,7,12,13,16,17-octahydro-inner salt (Texas Red (TR)) reporter dye and UQ2 anthraquinone quencher. The probe (SEQ ID No: 7) was used with varying amounts of input target DNA molecules as indicated. Relative fluorescence units (Y-axis) are plotted against PCR cycle number (X-axis).
[0017] FIG. 4 shows fluorescence curves generated using indodicarbocyanine 5 (Cy5) reporter dye and UQ2 quencher as in FIG. 3 . The probe (SEQ ID No: 8) was used with varying input target DNA molecules as indicated. Relative fluorescence units (Y-axis) are plotted against PCR cycle number (X-axis).
DETAILED DESCRIPTION OF THE INVENTION
[0018] The present invention stems, in part, from the discovery that the anthraquinone class of molecules, including 1,4-diamino anthraquinone compounds, have surprisingly strong quenching properties. These quenchers also overlap and efficiently quench fluorescence of a surprisingly wide wavelength range of emitted fluorescent light. Advantageously, they do not fluoresce. Consequently, they generally exhibit lower fluorescent backgrounds than quenchers that quench light at certain wavelengths and emit fluorescence over a wavelength range that bleeds into the fluorescent wavelength range of the reporter dye.
[0019] The anthraquinone quenchers of the present invention are easily purified. In certain instances a single purification using reverse phase HPLC chromatography provides highly pure compound. For example, the present quenchers can be incorporated into oligonucleotide probes and used in a variety of applications, including for example PCR applications and RNase detection and various nucleic acid binding assays.
[0000]
[0020] The compositions of the present invention include anthraquinone compounds of formula (1) wherein the groups R 7 , R 8 , R 9 , and R 10 can be hydrogen or an electron withdrawing group; the groups R 1 , R 14 , and R 15 can be hydrogen or electron donating groups; R 6 can be any group other than acetyl that can covalently bind to the nitrogen; X can include a solid support, a biologically relevant molecule, or a linker that can be used to attach the composition to another molecule. In addition, adjacent R groups of R 7-16 can be part of an aromatic ring or aromatic ring system.
[0000]
[0021] Many electron withdrawing groups are known in the art and can be used. Exemplary electron withdrawing groups include nitro, cyano, carboxylate, sulfonyl, sulfamoyl, alkenyl, alkynyl, aryl, heteroaryl, biaryl, bialkenyl, bialkynyl, alkoxycarbonyl, carbamoyl, mono- or di-substituted amino groups, or similar groups that do not substantially diminish quenching. In one embodiment R 1 is nitrogen and R 14 is a heterocyclic group as shown in formula (1a) below.
[0022] Many electron donating groups are known in the art and can be used. Exemplary electron donating groups include alkoxy, alkyl, alkylamine, arylamine, cycloalkyl, heteroalkoxy, heteroalkyl, or similar groups that do not substantially diminish quenching.
[0023] In formula (1), X can be a biologically relevant molecule and R 1 can be —NR 16 R 17 wherein R 16 and R 17 can independently be hydrogen, alkyl, alkynyl, alkenyl, aryl, heteroaryl, cycloalkyl, heteroalkyl, alkoxy, alkoxycarbonyl, carbonyl, carbamoyl, alkylaryl, heteroalkyl group, or the like. In another embodiment, X includes a biologically relevant molecule and R 1 can be —NR 16 R 17 wherein one of R 16 and R 17 can be hydrogen and the other can be a phenyl or other group.
[0024] In one preferred embodiment R 1 can be aniline which is bound to the anthraquinone through nitrogen. In another embodiment, R 1 is as defined above and R 6 , R 7 , R 8 , R 9 , or R 10 are each hydrogen. In another embodiment, of the composition of formula (1), X includes a biologically relevant molecule and R 1 is —NR 16 R 17 wherein R 16 and R 17 can independently be hydrogen, alkyl, alkynyl, alkenyl, aryl, heteroaryl, cycloalkyl, heteroalkyl, alkoxy, alkoxycarbonyl, carbonyl, carbamoyl, alkylaryl, heteroalkyl group, or the like and R 6 , R 7 , R 8 , R 9 , and R 10 are each hydrogen. In another embodiment X includes a biologically relevant molecule and R 1 is a mono- or di-substituted amine, wherein the substituent is independently, alkyl or aryl, preferably methyl or phenyl; and R 6 , R 7 , R 8 , R 9 , and R 10 are each hydrogen.
[0000]
[0025] In certain embodiments X can have the structure of formula (2) wherein the phosphorous in formula 2 can have +3 or +5 oxidation state. In formula (2) Z can be a linking group or a bond and R 2 , R 3 , and R 4 can be an electron pair, linking group, oxygen, hydrogen, sulfur, alkyl, alkynyl, alkenyl, aryl, heteroaryl, cycloalkyl, heteroalkyl, alkoxy, carbonyl, carbamoyl, alkylaryl, heteroalkoxy, or —NR 11 R 12 or —OR 13 , provided that not more than one of R 2-4 can be an electron pair and that each of R 11 , R 12 , and R 13 can be either a hydrogen, alkyl, alkynyl, alkenyl, aryl, heteroaryl, cycloalkyl, heteroalkyl, alkoxy, alkoxycarbonyl, carbonyl, carbamoyl, alkylaryl, heteroalkyl group or the like. In one embodiment at least one of R 2-4 can be a linker that joins the phosphorous to a nucleotide, nucleotide precursor, or nucleotide analog, including a phosphoramidite form of a nucleotide. One preferred embodiment of formula 2 is shown in formula (3).
[0000]
[0026] In certain embodiments of formulas (1) and (1a), X can be the compound of formula (2) and each of R 2 , R 6 , R 7 , R 8 , R 9 , and R 10 , can be hydrogen. In another embodiment of formula (1) R 1 can be —NR 16 R 17 where R 16 can be hydrogen and R 17 can be a phenyl or other group; and X can be a compound of formula (3).
[0027] In certain embodiments of formulas (1) and (1a), X can be of formula (2) and R 4 can be a compound of formula (4), PG.sub.1 can be a protecting group as is known in the art or can be a solid support as is known, and PG 2 can be any suitable protecting group or can be substituted with a biologically relevant molecule such as a nucleic acid, protein, their precursors or analogs.
[0028] In certain embodiments of formulas (1) and (1a), X can be the group of formula (3) and R 1 is a mono- or di-substituted amine, wherein the substituent is independently hydrogen, alkyl or aryl, preferably methyl or phenyl; and R 6 , R 7 , R 8 , R 9 , and R 10 are each hydrogen. Preferably R 1 is a mono- or di-substituted amine wherein one preferred substitution is a phenyl group.
[0000]
[0029] In certain embodiments of formulas (1) and (1a), X can be a group as in formula (2) wherein R 4 includes a nucleic acid or nucleoside or analog thereof that can be attached to the phosphate through a linker.
[0030] In certain embodiments of formulas (1) and (1a), X can be a group as in formula (2) wherein R 4 includes a nucleic acid or nucleoside or analog thereof that can be attached to the phosphate through a linker and R 1 can be a mono or di-substituted amine where the amine substituents can be hydrogen, alkyl, or aryl groups, independently. In one preferred embodiment R 4 can be a group as in formula (2) wherein R 4 can be formula (4) and PG 2 can be a nucleic acid or nucleoside or an analog thereof.
[0031] The term “linking group” and “linker” are used interchangeably and refer to a chemical group that is capable of reacting with a “complementary functionality” of a reagent, e.g., to the oxygen of a nucleoside or nucleotide or nucleic acid, and forming a linkage that connects the anthraquinone quenching compound to the reagent. The linking group can be used to link, preferably by way of covalent attachment, an anthraquinone compound to a reagent. When the complementary functionality is amine, preferred linking groups include such groups as isothiocyanate, sulfonylchloride, 4,6-dichlorotriazinyl, carboxylate, succinimidyl ester, other active carboxylate, e.g., —C(O)halogen, —C(O)OC 1-4 alkyl, or —C(O)OC(O)C 1-4 alkyl, amine, lower alkycarboxy or —
[0032] (CH 2 ) m N + (CH 3 ) 2 (CH 2 ) m COOH, wherein m is an integer ranging from 2 to 12. Typically, when the complementary functionality is amine, the linking group is an N-hydroxysuccinimidyl (NHS) ester. When the complementary functionality is oxygen, the linking group can be of formula (4) wherein PG, is an oxygen-protecting group or a solid support and PG 2 can be the nucleotide. When the complementary functionality is sulfhydryl, the linking group is preferably maleimide, halo acetyl, or iodoacetamide. See R. 35 Haugland (1992) Molecular Probes Handbook of Fluorescent Probes and Research Chemicals, Molecular Probes, Inc., disclosing numerous dyes and modes for conjugating them to a variety of compounds which sections are incorporated herein by reference.
[0033] The disclosed anthraquinone quenching compositions can be linked to a variety of molecules and substances without altering their quenching or spectral properties, or in many instances, the biological activity of the reagent. The anthraquinone quenching moiety known as 1-(methylamino)-4-(2-hydroxy-ethylamino)-anthraquinone is abbreviated as UQ1. The anthraquinone quenching moiety known as 1-(phenylamino)-4-(2-hyd-roxy-ethylamino)-anthraquinone is abbreviated as UQ2.
[0034] The term “protecting group” is symbolized by PG and means a group that is reversibly attached to a moiety that renders that moiety stable in subsequent reaction(s) and that can be selectively cleaved to regenerate that moiety once its protecting purpose has been served. For example, numerous hydroxy-protecting groups are known in the art and can be used. Many such groups are described in Greene, T. W., Protective Groups in Organic Synthesis, 3rd edition 17-237 (1999), which is incorporated herein by reference. Preferably, the hydroxy-protecting group is stable in a basic reaction medium and can be cleaved by acid. Examples of suitable base-stable, acid-labile hydroxy-protecting groups suitable for use with the invention include, ethers, such as methyl, methoxy methyl, methylthiomethyl, methoxyethoxymethyl, bis(2-chloroethoxy)methyl, tetrahydropyranyl, tetrahydrothiopyranyl, tetrahydrofuranyl, tetrahydrothiofuranyl, 1-ethoxyethyl, 1-methyl-1-methoxyethyl, t-butyl, allyl, benzyl, o-nitrobenzyl, triphenylmethyl, .alpha.-naphthyldiphenylmethyl, p-methoxyphenyldiphenylmethyl, 9-(9-phenyl-10-oxo)anthranyl, trimethylsilyl, isopropyldimethylsilyl, t-butyldimethylsilyl, t-butyldiphenylsilyl, tribenzylsilyl, and triisopropylsilyl; and esters, such as pivaloate, adamantoate, and 2,4,6-trimethylbenzoate. The preferred protecting group for hydroxyl groups, especially the C-5 carbon of a ribose or deoxyribose is the dimethoxytrityl group the use of which is well known in the art.
[0035] The present invention also includes methods for making the disclosed compositions. For instance, a compound of formula (1) wherein X is a group as in formula (2) can be prepared by contacting a compound of formula (5) with a compound of formula (6) under conditions suitable for the displacement of the halide ion (HAL). The groups R 2-5 are as described above, for example, R 2 can be an electron pair and R 3 and R 4 can be diisopropylamino groups. In one method the compound of formula (5) is added to the compound of formula (6) at 0° C. and the reaction mixture is warmed to room temperature with stirring to form the compound of formula (7).
[0000]
[0036] Where R 10 is not identical to R 7 , R 9 is not identical to R 8 , and/or R 14 is not identical to R 15 the synthesis will result in isomers which will have nearly identical fluorescent quenching properties.
[0037] A linker can then be added to the resulting compound by reacting the product with a compound such as (OH)-L-O-PG under conditions suitable for the addition of —O-L-O-PG at R 4 . The protecting group (PG) can then be removed such as by reaction with an acid and the linker, L, reacted with a biologically relevant compound, such as a nucleic acid, so that it becomes covalently attached to the anthraquinone through linker, L, as defined above.
[0038] Biologically relevant compounds include classes of compounds such as peptides, polypeptides, proteins (e.g., antibodies), nucleic acids (including, e.g., oligonucleotides, nucleosides, whether deoxy or ribonucleotides and their analogs), polysaccharides, and lipids.
[0039] The compounds of the invention are identified herein by their chemical structure and/or chemical name. Where a compound is referred to by both a chemical structure and a chemical name, and the chemical structure and chemical name conflict, the chemical structure is determinative of the compound's identity.
[0000]
[0040] Another class of reagent encompassed by the invention includes phosphoramidite compounds that incorporate the anthraquinones of formula (1). These compounds are particularly useful for the automated chemical synthesis of nucleic acid polymers with covalently bound anthraquinone compounds of formula (1). Such phosphoramidite reagents, when reacted with nucleophiles such as hydroxyl groups, especially the 5′-hydroxyl group of a nucleoside or nucleotide or nucleic acid, form a phosphite ester linkage that can be oxidized to a phosphate ester linkage by known methods. The phosphoramidite reagents can be nucleosidic or non-nucleosidic.
[0041] The invention also provides nucleic acid compositions that contain the disclosed anthraquinone compositions. For example, oligonucleotides containing the disclosed anthraquinone quenchers are contemplated as well as nucleotide precursors for use in the synthesis of such oligonucleotides. Oligonucleotide embodiments can contain regions with internal complementarity. In addition, one or more of the nucleotides can be ribonucleotide(s) or can be analogs of nucleotides.
[0042] Methods for preparing anthraquinone-containing oligonucleotides generally involve the use of anthraquinone phosphoramidite precursors or anthraquinone derivatized solid supports that can be used conveniently in conjunction with automated oligonucleotide synthesizers. Such precursors are also contemplated by the present invention. Alternatively, certain oligonucleotides can be prepared such that they have reactive groups that can later be used to join with suitable anthraquinone compositions.
[0043] The invention also provides nucleic acid compositions containing, in addition to the a disclosed anthraquinone quencher, a fluorescent dye which emits fluorescence upon exposure to light of the appropriate wavelength. Where the quencher quenches the fluorescence of the fluorophore on the oligonucleotide, suitable dye pairs include at least one of the disclosed anthraquinone quenching compositions and at least one corresponding fluorescent reporter dye that fluoresces within the absorbance spectrum of the quencher such that the fluorescence can be quenched.
[0044] In certain embodiments, the dye pair comprises at least one of the disclosed anthraquinone quenching molecules and at least one corresponding fluorescent reporter dye attached to a single compound, such as an oligonucleotide, so that the anthraquinone quencher is within sufficient proximity of the fluorophore to quench its fluorescence. In other embodiments, the fluorescent reporter dye and the anthraquinone quencher can be on different molecules.
[0045] Oligonucleotides containing an anthraquinone or dye pair of the invention can be purified by any suitable method. For example, they can be purified by reverse-phase HPLC. Specifically, a sample containing the anthraquinone modified oligonucleotide can be loaded on a reverse-phase column, such as a Hamilton PRP-1 column (1 cm.times.25 cm), and eluted with a linear 5% to 50% acetonitrile gradient over 40 min. The portion of the eluant corresponding to the desired dye-labeled oligonucleotide species can be collected and lyophilized. Because the disclosed anthraquinone quenchers are relatively hydrophobic, this method can be used advantageously in the purification of modified oligonucleotides which will have increased hydrophobicity. The lyophilized oligonucleotide can then be dissolved in water and precipitated, for example with 2% lithium perchlorate in acetone, followed by centrifugation, e.g., at 10,000 g for 10 min. The precipitate can be washed with 10% aqueous acetone.
[0046] Oligonucleotides can also be purified by ion-exchange HPLC. For example, the oligonucleotides can be loaded on a 5.times.10 Source™ column (Amersham Pharmacia Biotech, Piscataway, N.J.) and eluted using a linear 0 to 50% gradient of 1 M LiCl in a 0.1 M TRIS buffer having a pH of about 8.0. The portion of the eluant corresponding to the oligonucleotide species can be collected and precipitated with 2% lithium perchlorate in acetone and lyophilized.
[0047] A wide variety of reactive fluorescent reporter dyes are known in the literature and can be used so long as they are quenched by the corresponding quencher dye of the invention. Typically, the fluorophore is an aromatic or heteroaromatic compound and can be a pyrene, anthracene, naphthalene, acridine, stilbene, indole, benzindole, oxazole, thiazole, benzothiazole, cyanine, carbocyanine, salicylate, anthranilate, coumarin, fluoroscein, rhodamine or other like compound. Suitable fluorescent reporters include xanthene dyes, such as fluorescein or rhodamine dyes, including 5-carboxyfluorescein (FAM), 2′7′-dimethoxy-4′5′-dichloro-6-carboxyfluorescein (JOE), tetrachlorofluorescein (TET), 6-carboxyrhodamine (R6G), N,N,N;N′-tetramethyl-6-carboxyrhodamine (TAMRA), 6-carboxy-X-rhodamine (ROX). Suitable fluorescent reporters also include the naphthylamine dyes that have an amino group in the alpha or beta position. For example, naphthylamino compounds include 1-dimethylaminonaphthyl-5-sulfonate, 1-anilino-8-naphthalene sulfonate and 2-p-toluidinyl-6-naphthalene sulfonate, 5-(2′-aminoethyl)aminonaphthalene-1-sulfonic acid (EDANS). Other fluorescent reporter dyes include coumarins, such as 3-phenyl-7-isocyanatocoumarin; acridines, such as 9-isothiocyanatoacridin-e and acridine orange; N-(p-(2-benzoxazolyl)phenyl)maleimide; cyanines, such as indodicarbocyanine 3 (Cy3), indodicarbocyanine 5 (Cy5), indodicarbocyanine 5.5 (Cy5.5), 3-(-carboxy-pentyl)-3′-ethyl-5,5′-dimethy-loxacarbocyanine (CyA); 1H, 5H, 11H, 15H-Xantheno[2,3,4-ij:5,6,7-i′j′]diquino-lizin-18-ium, 9-[2(or 4)-[[[6-[2,5-dioxo-1-pyrrolidinyl)oxy]-6-oxohexyl]am-ino]sulfonyl]-4(or 2)-sulfophenyl]-2,3,6,7,12,13,16,17-octahydro-inner salt (TR or Texas Red); BODIPY®. dyes; benzoxadiazoles; stilbenes; pyrenes; and the like. The fluorescent emission of certain reporter dyes are provided below.
[0000]
Fluorophore
Emission Max
Fluorescein
520 nm
Tetrachlorofluorescein (TET)
536 nm
Hexachlorofluorescein (HEX)
556 nm
Cy3
570 nm
Tetramethylrhodamine (Tamra)
580 nm
Cy3.5
596 nm
Carboxy-x-rhodamine (Rox)
605 nm
Texas Red
610 run
Cy5
667 nm
Cy5.5
694 nm
[0048] Many suitable forms of these fluorescent compounds are available and can be used depending on the circumstances. With xanthene compounds, substituents can be attached to xanthene rings for bonding with various reagents, such as for bonding to oligonucleotides. For fluorescein and rhodamine dyes, appropriate linking methodologies for attachment to oligonucleotides have also been described. See for example, Khanna et al. U.S. Pat. No. 4,439,356; Marshall (1975) Histochemical J., 7:299-303; Menchen et al., U.S. Pat. No. 5,188,934; Menchen et al., European Patent Application No. 87310256.0; and Bergot et al., International Application PCT/U590/05565).
[0049] Preferably, when the dye pair is in a configuration in which the reporter dye is effectively quenched by the anthraquinone quencher dye, its fluorescence is reduced by at least a factor of 50%, more preferably by at least 70%, more preferably by at least 80%, 90%, 95%, or 98%, when compared to its fluorescence in the absence of quenching.
[0050] Probes having a high signal to noise ratio are desirable for the development of highly sensitive assays. To measure signal to noise ratios relative fluorescence is measured in a configuration where the quencher and fluorophore are within the Forster distance and the fluorophore is maximally quenched (background fluorescence or “noise”) and compared with the fluorescence measured when fluorophore and quencher are separated in the absence of quenching (“signal”). The signal to noise ratio of a dye pair of the invention will generally be at least about 2:1 but generally is higher. Signal to noise ratios of about 5:1, 10:1, 20:1, 40:1 and 50:1 are preferred. Ratios of 60:1, 70:1 and even up to 100:1 and higher can also be obtained in some cases. Intermediate signal to noise ratios are also contemplated.
[0051] The disclosed anthraquinone quenching compounds effectively quench fluorescence over a surprisingly wide range of wavelengths. For some anthraquinone compositions the absorbance spectrum is in the range of from about 400 to 800 nm, more typically quenching compositions have an absorbance spectrum in the range of about 500 to 700 nm. As indicated previously, the absorbance range of a suitable anthraquinone quencher must overlap the fluorescence emission of the fluorophore of suitable dye pairs. Methods for measuring the effective absorbance range of a quenching composition are known and any suitable method can be used.
[0052] Suitable dye-pairs can be used in many configurations. For example, the dye combination can be placed on nucleic acid oligomers and polymers. For example, a dye-pair can be disposed on an oligomer having a hairpin structure such that the fluorophore and quencher are within the Forster distance and FRET occurs. Alternatively, dye pairs can be disposed on an oligomer that can adopt a random coil conformation, such that fluorescence is quenched until the oligonucleotide adopts an extended conformation, as when it becomes part of a duplex nucleic acid polymer. In general, the individual dye moieties can be placed at any position of the nucleic acid depending upon the requirements of use.
[0053] Nucleic acid oligomers and polymers that include the dye pairs of the invention can be used to detect target nucleic acids. In one method, the individual components of a dye-pair can be on opposing, annealable, self-complementary segments of an oligonucleotide such that when the oligonucleotide anneals to itself in the absence of exogenous sequences FRET occurs. The oligonucleotide is constructed in such a way that the internal annealing is disrupted and fluorescence can be observed when it hybridizes to nucleic acid polymers having sufficient complementarity. Such an oligonucleotide can be used to rapidly detect nucleic acid polymers having sequences that bind to the oligonucleotide. In another embodiment, such a composition comprises two biomolecules, such as oligonucleotides, one of which is attached to a reporter dye and the other of which is attached as an anthraquinone quencher dye.
[0054] Oligonucleotide probes lacking self-complementarity can also be utilized in a similar manner. For example, an anthraquinone quencher and fluorophore can be placed on an oligonucleotide that lacks the self-annealing property such that the random-coil conformation of the oligonucleotide keeps the fluorophore and quencher within a suitable distance for fluorescence quenching. Such oligonucleotides can be designed so that when they anneal to desired target nucleic acid polymers the fluorophore and quencher are more separated and the spectral characteristics of the fluorophore become more apparent.
[0055] Other DNA binding formats are also possible. For example, two oligonucleotides can be designed such that they can anneal adjacent to each other on a contiguous length of a nucleic acid polymer. The two probes can be designed such that when they are annealed to such a nucleic acid polymer an anthraquinone quencher on one of the oligonucleotides is within a sufficient proximity to a fluorophore on the other oligonucleotide for FRET to occur. Binding of the oligonucleotides to the nucleic acid polymer can be followed as a decrease in the fluorescence of the fluorophore.
[0056] Alternatively, a set of oligonucleotides that anneal to each other such that an anthraquinone quencher and a fluorophore can be positioned on opposing oligonucleotides so that they are within the Forster distance. Incubation of such an oligonucleotide duplex with a nucleic acid polymer that competes for binding of one or both of the oligonucleotides would cause a net separation of the oligonucleotide duplex leading to an increase in the fluorescent signal of the reporter dye. To favor binding to the polymer strands one of the oligonucleotides could be longer or mismatched could be incorporated within the oligonucleotide duplex.
[0057] These assay formats can easily be extended to multi-reporter systems where mixtures of distinct oligonucleotides having fluorophores with distinct spectrally resolvable emissions. The binding of individual oligonucleotides can then be detected by determining the fluorescent wavelengths that are emitted from a sample. Such multi-reporter systems are advantageous in applications requiring the analysis of multiple hybridization events in a single reaction volume.
[0058] Oligonucleotides can also be configured with the disclosed anthraquinone quenchers such that they can be used to monitor the progress of PCR reactions without manipulating the PCR reaction mixture (i.e., in a closed tube format). The assay utilizes an oligonucleotide that is labeled with a fluorophore and an anthraquinone quencher in a configuration such that fluorescence is substantially quenched. The oligonucleotide is designed to have sufficient complementarity to a region of the amplified nucleic acid so that it will specifically hybridize to the amplified product. The hybridized oligonucleotide is degraded by the exonuclease activity of Taq™ polymerase in the subsequent round of DNA synthesis. The oligonucleotide is designed such that as the oligomer is degraded one of the members of the dye-pair is released and fluorescence from the fluorophore can be observed. An increase in fluorescence intensity of the sample indicates the accumulation of amplified product.
[0059] Ribonucleic acid polymers can also be configured with fluorophores and anthraquinone quenchers and used to detect RNase. For example, a dye-pair can be disposed on opposite sides of an RNase cleavage site in an RNase substrate such that the fluorescence of the fluorophore is quenched. Suitable substrates include nucleic acid molecules that have a single-stranded region that can be cleaved and that have at least one internucleotide linkage immediately 3′ to an adenosine residue, at least one internucleotide linkage immediately 3′ to a cytosine residue, at least one internucleotide linkage immediately 3′ to a guanosine residue and at least one internucleotide linkage next to a uridine residue and optionally can lack a deoxyribonuclease-cleavable internucleotide linkage. To conduct the assay the substrate can be incubated with a test sample for a time sufficient for cleavage of the substrate by a ribonuclease enzyme, if present in the sample. The substrate can be a single-stranded nucleic acid molecule containing at least one ribonucleotide residue at an internal position. Upon cleavage of the internal ribonucleotide residue, the fluorescence of the reporter dye, whose emission was quenched by the anthraquinone quencher, becomes detectable. The appearance of fluorescence indicates that a ribonuclease cleavage event has occurred, and, therefore, the sample contains ribonuclease activity. This test can be adapted to quantitate the level of ribonuclease activity by incubating the substrate with control samples containing known amounts of ribonuclease, measuring the signal that is obtained after a suitable length of time, and comparing the signals with the signal obtained in the test sample.
[0060] Generally, any of the described assays could be conducted with positive controls that can be used to indicate whether the assay was functioning properly.
[0061] The invention also provides kits containing in one or more containers, at least one of the disclosed anthraquinone quenching dye compositions and instructions for its use. Such kits can be useful for practicing the described methods or to provide materials for synthesis of the compositions as described. Additional components can be included in the kit depending on the particular application that utilizes the compounds of the invention. For example, where the kit is directed to measuring the progress of PCR reactions, it may include a DNA polymerase. Where a kit is intended for the practice of the RNase detection assays, RNase-free water could be included. Kits can also contain negative and/or positive controls and buffers.
[0062] The following examples further illustrate the invention but, of course, should not be construed as in any way limiting its scope. In particular the following examples demonstrate synthetic methods for obtaining the compounds of the invention. Starting materials useful for preparing the compounds of the invention and intermediates thereof, are commercially available or can be prepared from commercially available materials using known synthetic methods and reagents.
Example 1
[0063] This example demonstrates the conversion of 1,4-hydroxyl groups of an anthraquinone compound 1 to leaving groups as shown in Scheme 1. “E” in compound 2 can be any suitable leaving group. Many suitable leaving groups are known in the art and can be used, for example, halides, aryl alkylsulfonyloxy, substituted arylsulfonyloxy (e.g., tosyloxy or mesyloxy), substituted alkylsulfonyloxy (e.g., haloalkylsulfonyloxy), phenoxy or substituted phenoxy, and acyloxy groups. Compounds of type 1 are available commercially (e.g., Aldrich Chemical Co., Milwaukee, Wis.). The reaction requires a suitable base which includes bases having a pKa of about 10 or more. Suitable bases include alkylamine bases like triethylamine, dipropylamine; metal amide bases, including lithium amide, sodium amide, potassium amide, lithium tetramethylpiperidide, lithium diisopropylamide, lithium diethylamide, lithium dicyclohexylamide, sodium hexamethyldisilazide, and lithium hexamethyldisilazide; hydride bases including sodium hydride and potassium hydride. Alkylamine bases, like triethylamine are preferred.
[0000]
[0064] To convert compound 1 to compound 2, a solution of about 1 to about 1.2 equivalents of a suitable base is added to a stirred solution of compound 1 in a suitable organic solvent under an inert atmosphere, such as argon. Suitable organics solvents include moderately polar aprotic solvents. The solution is maintained at a constant temperature between about −100° C. or higher to about room temperature, and more preferably between about −80° C. to about 20° C. The base is diluted in a suitable organic solvent before the addition and is added slowly enough to avoid over heating the reaction. Organic solvents suitable for the conversion of compound 1 to compound 2 include those solvents in which the reactants and products are soluble and include dichloromethane, diethyl ether, tetrahydrofuran, benzene, toluene, xylene, hydrocarbon solvents (e.g., pentane, hexane, and heptane), and mixtures thereof. After addition of the base, the reaction mixture is stirred for about 1 to 4 h such that the reaction-mixture temperature remains within several degrees of the starting temperature. The temperature can then be adjusted to between about −20° C. to about room temperature, preferably to about room temperature, and the reaction stirred until it is substantially complete as determined analytically, as by thin-layer chromatography or high-performance liquid chromatography. Then the reaction mixture can be quenched and compound 2 isolated by standard methods.
Example 2
[0065] This example demonstrates the conversion of the 1,4-leaving groups of compound 2 to 1-substituted amino-4-β-hydroethylaminoanthraquinones 4 according to Scheme 2.
[0066] A solution of about 1 equivalent of compound 2 is dissolved in a suitable organic solvent under an inert atmosphere. Suitable solvents include polar aprotic solvents such as, dimethylformamide, acetonitrile, and dimethylsulfoxide in which compound 2 is soluble. The solution is maintained at room temperature during the addition of about 10 equivalents of the substituted amine and stirred for about 1 h to 4 h at a temperature of about 150° C. until the reaction is substantially complete as determined analytically by thin-layer chromatography or high-performance liquid chromatography. The reaction mixture is then cooled to room temperature and quenched to give compounds 3 and 3′. Compounds 3 and 3′
[0000]
[0000] can be separated by flash chromatography or HPLC to obtain compound 3. Alternatively, compounds 3 and 3′ 9 can be treated with ethanolamine to prepare compound 4 prior to separation.
[0067] To obtain compound 4a solution of about 1 equivalent of compound 3 is dissolved in a suitable organic solvent, as defined previously in this example, under an inert atmosphere. About 250 equivalents of ethanolamine is added in a single addition and the reaction mixture is stirred for about 1 to about 3 h, preferably 2 h at about 100° C. until the reaction is substantially complete as determined analytically by thin-layer chromatography or high-performance liquid chromatography. The reaction mixture is then cooled to room temperature and quenched to give compound 4 which can be purified further by a variety of well known techniques, including preparatory high-performance chromatography or flash chromatography.
Example 3
[0068] This example demonstrates synthesis of 1-substituted amino-4-(2-cyanoethyl-phosphoramidite-ethylamino)-anthraquinone as shown in Scheme 3. A 2 M solution of anthraquinone 4 in triethylamine is prepared. The solution is cooled to about 0° C. and about 1-2 equivalents of a phosphonic chloride compound is added. The reaction mixture is warmed to room temperature and allowed to stir for about 4 h until the reaction is substantially complete as
[0000]
[0000] determined analytically. The reaction mixture is quenched and compound 5 is isolated by standard procedures.
[0069] The method can be used to synthesize anthraquinone phosphoramidite compounds wherein each occurrence of R 16 , R 17 , and R 7-10 is independently hydrogen, alkyl, alkynyl, alkenyl, aryl, heteroaryl, cycloalkyl, heteroalkyl, alkoxy, alkoxycarbonyl, carbonyl, carbamoyl, alkylaryl, heteroalkyl group, or the like. R 2-6 are independently an electron pair, oxygen, hydrogen, alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, heteroalkyl, alkoxy, alkoxycarbonyl, carbamoyl, or similar substituent, or a mono- or di-substituted amine as defined previously; and HAL represents a halogen atom, typically chlorine.
Example 4
[0070] This example demonstrates synthesis of an anthraquinone quencher covalently linked to a linker (L) as shown in Scheme 4. Anthraquinone compound 5 is mixed for about 0.5 h under an inert atmosphere with a hydroxy-containing linker compound (HO-L) and ethylthiotetrazole in a suitable organic solvent as in Example 2. L could be a nucleotide or nucleic acid polymer. A second solution of compound 5 in acetonitrile and ethylthiotetrazole is then added and the reaction mixture stirred for an additional 0.5 h. The reaction mixture is washed with acetonitrile and treated with 10% (v/v) methylimidazole in THF/pyridine (8:1) under an inert atmosphere for about 0.5 h. The reaction product is separated and washed with acetonitrile and treated with 0.02 M iodine in THF/pyridine/H 2 O (78:20:2), which is added slowly over 5 min. The reaction mixture is isolated and dried overnight in a vacuum to provide compound 6. L could be a nucleotide or oligonucleotide with a free hydroxyl group.
[0000]
Example 5
[0071] This example demonstrates the conversion of a single hydroxyl group of an anthraquinone to a leaving group as shown in Scheme 6. Suitable leaving groups are as defined above in Example 1.
[0072] To convert a compound 8 to compound 9, a solution of about 1 to about 1.2 equivalents of a suitable base is added to a stirred solution of a monohydroxy-anthraquinone 8 in an organic solvent under an inert atmosphere. The solution is maintained at a constant temperature between about −100° C. to about room temperature, and more preferably between at about −80° C. to about 20° C. The base is diluted in a suitable organic solvent, as described in Example 2, before the addition and is added to avoid over heating of the reaction mixture. After addition of the base, the reaction mixture is allowed to stir for about 1 to 4 h such that the temperature remains within several degrees of the starting temperature. The temperature can then be adjusted to between about −20° C. to about room temperature, preferably to about room temperature, and the reaction stirred until it is substantially complete as determined analytically, such as by thin-layer chromatography or high-performance liquid chromatography. The reaction mixture is quenched and compound 9 is isolated by standard methods.
[0000]
Example 6
[0073] This example demonstrates a method useful for converting the leaving group of anthraquinone compound 9 to the corresponding amino-4-β-hydroxyethylaminoanthraquinone 10 as shown in scheme 7.
[0074] A solution of about 1 equivalent of compound 9 is dissolved in a suitable organic
[0000]
[0000] solvent, as described above, under an inert atmosphere. About 250 equivalents of ethanolamine is added to this solution in a single aliquot. The reaction mixture is allowed to stir for about 1 to about 3 h, depending on the rate of stirring, preferably 2 hours at about 100° C. with stirring at a rate that maintains the temperature at about 100° C. Stirring is continued until the reaction is substantially complete as determined analytically, such as by thin-layer chromatography or high-performance liquid chromatography. The reaction mixture is then cooled to room temperature and quenched to provide compound 10 which can be purified by known techniques such as, preparative HPLC or flash chromatography.
Example 7
[0075] This example demonstrates the synthesis of 1-substituted amino-4(2-cyanoethyl phosphoramidite-ethylamino)-anthraquinone as shown in scheme 8. A 2 M solution of anthraquinone compound 10 is prepared in triethylamine. The solution is cooled to 0° C. and
[0000]
[0000] about 1-2 equivalents of a phosphonic chloride compound is added. The reaction mixture is warmed to room temperature and stirred for about 4 h until substantially complete as determined analytically. The reaction mixture is quenched and compound 11 is isolated by standard methods.
Example 8
[0076] This example demonstrates the synthesis of an anthraquinone quencher that is covalently bonded to a linker (L) as shown in Scheme 9. Anthraquinone compound 11 is dissolved in an organic solvent, such as acetonitrile, with ethylthiotetrazole and HO-L under an inert atmosphere. L could be a nucleotide or nucleic acid polymer. The solution is maintained at room temperature and stirred for about 0.5 h. A second solution of 11 in acetonitrile and ethylthiotetrazole is added to the reaction mixture with stirring for an additional 0.5 h. The reaction mixture is washed with acetonitrile and treated with 10% (v/v) acetic anhydride solution in THF and mixed with an equal volume of 10% (v/v) methylimidazole in an 8:1 mixture of
[0000]
[0000] THF/pyridine, all under an inert atmosphere. After about 30 min the reaction mixture is washed with acetonitrile and treated with 0.02 M iodine in THF/pyridine/H 2 O solution (78:20:2), which is added over 5 min. The reaction mixture is isolated and dried overnight under vacuum to obtain compound 12.
Example 9
[0077] This example demonstrates the synthesis of 1-(methylamino)-4-(2-cyanoethylphosphoramidite-ethylamino)-anthraquinone 14 as shown below.
[0000]
[0000] N,N-diisopropylaminocyanoethyl-phosphonamidic chloride (0.10 mL, 0.51 mmol) was added dropwise at 0° C. to a solution of 1-(methylamino)-4-(2-hydroxy-ethylamino)-anthraquinone (100 mg, 0.34 mmol) and triethylamine (TEA) (0.12 mL, 0.68 mmol). The mixture was stirred at room temperature for 4 h. The solvent was removed and the residue was dissolved in ethylacetate (EtOAc) (2 mL). The product was isolated by flash chromatography on silica with EtOAc/petroleum ether (PE)/TEA: 40/50/10). .sup.1H NMR (CDCl 3 ) .delta.10.83 (t, J=5 Hz, 1H), 10.57 (d, J=5 Hz, 1H), 8.29-8.34 (m, 2H), 7.65-7.70 (m, 2H), 7.28 (d, J=10, 1H), 7.20 (d, J=10, 1H), 3.90-4.00 (m, 2H), 3.80-3.90 (m, 2H), 3.58-3.67 (m, 4H), 3.08 (d, J=5, 3H), 2.65 (t, J=6, 2H), 1.18 Ct J=6, 12H). MS (FAB′) [M+]: calculated for C 26 H 33 N 4 O 4 P, m/z 496.54; found, m/z 512.
Example 10
[0078] This example demonstrates the synthesis of 1-(phenylamino)-4-(2-hyd-roxyethylamino)-anthraquinone 15 as shown below. Aniline (49.8 mL, 547 mmol) was added to 1,4-bis(tosyloxy)anthraquinone (See Zielake, J. Org. Chem. 52: 1305-1309 (1987) (3 g, 5.47 mmol) in DMSO (120 mL) and heated at 150° C. for 2 h. The reaction was allowed to cool to
[0000]
[0000] room temperature and poured into 15% HCl solution (1.5 L), filtered and rinsed with water to give a reddish solid. The solid consisted of 1-(phenylamino)-4-(tosyloxy)anthraquinone (red color on TLC, R f 0.65, 20% EtOAc/PE) and 1,4-bis-(phenylamino)anthraquinone (blue color on TLC, R r 0.75, 20% EtOAc/PE). The solid was dried overnight under vacuum to give 2.2 g of a reddish solid. Ethanolamine (72 mL, 1173 mmol) was added to the reddish solid (2.2 g, 4.69 mmol) in DMSO (30 mL). The mixture was heated at 100° C. for 2 h. The reaction was brought to room temperature, poured into 10% HCl (1.5 L) and extracted with CH 2 Cl 2 (3.times.). The organic layer was washed with water (1.times.), dried over sodium sulfate and evaporated. Flash chromatography on silica with 50-100% EtOAc/PE gave a blue solid (0.6 g, 42% yield). TLC: Rf 0.45, 30% EtOAc/PE. .sup.1H NMR (CDCl 3 ).delta.12.09 (s, 1H), 10.81 (s, 1H), 8.26-8.32 (m, 2H), 7.74-7.76 (m, 1H), 7.67-7.71 (m, 2H), 7.52 (d, J=10 Hz, 1H), 7.37-7.42 (m, 2H), 7.31 (d, J=8 Hz, 1H), 7.24-7.26 (m, 1H), 7.13-7.19 (m, 2H), 3.96 (t, J=5 Hz, 2H), 3.59 (q, J=5 Hz, 2H). MS (FAB′) [M+]: calculated for C 22 H 18 N 2 O 3 , m/z 358.39; found, m/z 358.
Example 11
[0079] This example demonstrates the synthesis of 1-(phenylamino)-4-(2-cyanoethylphosphoramidite-ethylamino)-anthraquinone 16 as shown below.
[0000]
[0080] N,N-diisopropylamino-cyanoethylphosphonamidic chloride (0.93 mL, 4.19 mmol) was added dropwise to a solution of 1-(phenylamino)-4-(2-hydroxy-ethylamino)-anthraquinone (1 g, 2.79 mmol) and TEA (0.8 mL, 5.58 mmol) at 0° C. The mixture was stirred at room temperature for 3 h. The solvent was removed and the residue was dissolved into EtOAc (3 mL). Flash chromatography on silica with EtOAc/PE/TEA: 5/85/10-50/40/10 gave a blue solid (1.28 g, 82% yield). TLC: R f 0.70, EtOAc/PE/TEA: 40/50/10).sup.1H 30 NMR (CDCl 3 ) .delta.12.16 (s, 1H), 10.88 (t, J=5 Hz, 1H), 8.34 (dt, J=7,2,2 Hz, 2H), 7.69-7.75 (m, 2H), 7.60 (d, J=10 Hz, 1H), 7.39 (t, J=7 Hz, 2H), 7.26 (t, J=4 Hz, 2H), 7.15-7.20 (m, 2H), 3.92-4.00 (m, 2H), 3.82-3.90 (m, 2H), 3.60-3.69 (m, 4H), 2.67 (t, J=6 Hz, 2H), 1.19 (t, J=7 Hz, 12H). MS (FAB′) [M+]: calculated for C 31 H 35 N 4 O 4 P. m/z 558.61; found, m/z 558.
Example 12
[0081] This example demonstrates the synthesis of 1-(phenylamino)-4-(2-hydroxyethylamino)-anthraquinone-DMT-CPG 17, 19 also known as UQ2, as shown.
[0000]
[0082] Two grams of derivatized controlled porous glass (CPG) support 18 were treated with 10 mL of 3% (v/v) dichloroacetic acid in dichloromethane three separate times and washed with 5.times.10 ml of acetonitrile to provide compound 18.
[0083] A solution of 0.5 g of mono DMT-glycerol phosphoramidite (17a) in 5 mL of
[0000]
[0000] dry acetonitrile and 5 mL of 0.45 M ethylthiotetrazole was added to 18 under an argon atmosphere. After 20 min the reaction mixture was isolated, and the CPG washed with 5×10 mL
[0000]
[0000] of acetonitrile, followed by 10 mL of 10% (v/v) acetic anhydride solution in THF with 10 mL of a solution containing 10% (v/v) methylimidazole in 8:1 THF/pyridine, all under argon. After 30 min the reaction mixture was removed and the derivatized CPG was washed with 5.times.10 mL of acetonitrile, followed by 10 mL of 0.02 M iodine in THF/pyridine/H 2 O (78:20:2) solution, which was allowed to react with the CPG for 5 min. The treated CPG was isolated and washed with 5.times.10 mL of acetonitrile. A solution of 0.5 M hydrazine hydrate in 1:8 acetic acid/pyridine was mixed with the CPG under an argon atmosphere and the mixture allowed to react for 30 min. The CPG material was then isolated and washed with 5.times.10 mL of acetonitrile. A solution of 0.3 g of phosphoramidite 16 in 5 mL of dry acetonitrile and 5 mL of 0.45 M ethylthiotetrazole was added to the resulting CPG under an argon atmosphere. After 20 min the reaction mixture was removed and a fresh solution of 0.3 g of phosphoramidite 16 in 5 mL of dry acetonitrile and 5 mL of 0.45 M ethylthiotetrazole was added to resulting CPG under argon and allowed to react for an additional 20 min. (72 mL, 1173 mmol) The reaction mixture was removed, and CPG was washed with 5.times.10 mL of acetonitrile. A 10 mL solution of 10% (v/v) acetic anhydride solution in THF and 10 mL of 10% (v/v) methylimidazole in 8:1 mixture of THF/pyridine were added to resulting CPG under argon. After 30 min the reaction mixture was removed and CPG was washed with 5.times.10 mL of acetonitrile. The phosphite was oxidized to the phosphate by treatment with 10 mL of 0.02 M iodine in THF/pyridine/H 2 O (78:20:2) for 5 min. The reaction mixture was removed and the derivatized CPG washed with 5.times.10 mL of acetonitrile, followed by 2.times.10 mL of dichloromethane and dried overnight under vacuum to provide 2.2 g of derivatized CPG product.
Example 13
[0084] This example demonstrates a method for the synthesis of bis-1,4-(4-hydroxyethylphenylamino)-anthraquinone (19) according to the invention.
[0085] The starting material 4-phenethylamino alcohol (1.25 g, 9.1 mmol) was mixed with 1,4-Bis(tosyloxy)anthraquinone (0.5 g, 0.91 mmol) in DMSO (2 mL) and the mixture was heated at 180° C. for 16 h. Then 1M HCl solution was mixed in and the reaction was filtered and rinsed with water to give a blue solid. The solid was dried under vacuum and redissolved in ethylacetate (3 mL) with heat to facilitate dissolution. Purification of the product by flash chromatography in ethylacetate gave two solid compounds, one of which was blue the other of which was green. NMR analysis was used to confirm that the green compound was the desired product (0.19 g). .sup.1H NMR (CDCl 3 ).delta.12.23 (s, 1H), 8.36-8.40 (m, 2H), 7.73-7.77 (m, 2H), 7.48 (s, 2H), 7.21-7.27 (m. 9H), 3.89 (t, J=7 Hz, 4H), 2.89 (t, J=7 Hz, 4H), 1.48 (bs, 3H).
[0086] The above reaction was repeated in a larger scale using identical but scaled up conditions (ie. 15 g of 1,4-Bis(tosyloxy)-anthraquinone, 18.75 g (5 eq) of 4-phenethylamino alcohol in 30 mL DMSO). Half of the crude solid was purified using flash chromatography to provide 1 g of bis-1,4-(4-hydroxyethyl-phenylamino)-anthraquinone.
[0000]
[0087] These results demonstrate a method for preparing bis-1,4-(4-hydroxyethylphenylamino)-anthraquinone that is scalable.
Example 14
[0088] This example demonstrates a method for the synthesis of 1-(4-hydroxyethylphenylamino)-4-(DMT-4-hydroxyethyl-phenylamino)-anthraquinone (20) according to the invention. Dissolved dimethoxytrityl chloride (DMTCl) (0.3 g, 0.89 mmol) in anhydrous pyridine (15 mL) was added dropwise into a solution of bis-1,4-(4-hydroxyethyl-phenylamino)-anthraquinone in pyridine (15 mL) and allowed to react overnight. Analysis of the reaction products by thin layer chromatography showed two new products.
[0089] Pyridine was removed from the reaction mixture under a vacuum and the product was purified by flash chromatography with ethylacetate to provide two products having R f values of 0.5 and 0.8 along with starting material. .sup.1H NMR was used to confirm that the compound having an R f of 0.5 in ethylacetate was the desired product. .sup.1H NMR (CDCL 3 ) .delta.12.28 (s, 1H), 8.40-8.44 (m, 2H), 7.77-7.81 (m, 2H), 7.50 (s, 2H), 7.40-7.42 (m, 2H), 7.20-7.33 (m, 18H), 6.81-6.88 (m, 4H), 3.92 (t, J=6 Hz, 2H), 3.81 (s, 6H), 3.33 (t, J=7 Hz, 2H), 2.92 (t, J=7 Hz, 4H).
[0000]
Example 15
[0090] This example demonstrates the synthesis of 1-(β-cyanoethylphosphoramidite-4-hydroxyethyl-phenylamino)-4-(DMT-4-hydroxyethyl-phenylamino)-1-anthraquinone (21)
[0000]
[0000] according to the invention.
[0091] β-cyanoethyl N,N,N′,N′-tetraisopropylphosphorodiamidite (0.81 mL, 1.79 mmol) and 0.5 eq diisopropylamine 1H-tetrazole (60 mg, 0.64 mmol) were mixed into a solution of 1-(4-hydroxyethyl-phenylamino)-4-(DMT-4-hydroxyethyl-phenylamino)-anthraquinone (0.53 g, 1.28 mmol) in THF (10 ml). After 12 h the solid material was removed by filtration and the solvent was removed under a vacuum. The remaining oil residue was dissolved in a solvent that contained ethylacetate/petroleum ether/triethylamine (40/45/5) and loaded onto a silica column for flash chromatography in ethylacetate/petroleum ether/triethylamine: 20/75/5-40/45/5) to provide a blue oil (0.32 g, 26% yield) which has an R f of 0.75 in a silica thin layer chromatography plate developed with ethylacetate/petroleum ether/triethylamine 40/45/5).
Example 16
[0092] This example demonstrates the synthesis of oligonucleotides comprising an anthraquinone quencher dye and the measurement of the absorbance spectra of several anthraquinone quenchers.
[0093] An oligonucleotide bearing the anthraquinone quencher (UQ2) of the class of the invention was synthesized; its absorbance spectra was characterized and compared to the absorbance spectra of other representative dark quenchers, dabcyl, and QSY7.
[0094] The following oligonucleotides were synthesized:
[0000]
SEQ ID No 1:
CAGAGTACCTGA-UQ2
SEQ ID No 2:
CAGAGTACCTGA-QSY7
SEQ ID No 3:
CAGAGTACCTGA-Dabcyl
[0095] For all sequences A, C, G, T represent deoxynucleotides (DNA) and the oligonucleotide sequences are written with the 5′ end to the left and the 3′ end to the right unless otherwise noted. Oligonucleotide substrates were synthesized with the anthraquinone quencher UQ2, QSY7, and Dabcyl using standard phosphoramidite chemistry on an Applied Biosystems Model 394 DNA/RNA synthesizer. For the synthesis of SEQ ID NO 1 and all oligonucleotides containing UQ2, the CPG bound anthraquinone precursor prepared in Example 12 was used unless otherwise noted. The synthesis were carried out on a 1 .mu.mole scale. Thus, UQ2 derivatized solid support starting material contained 1 .mu.mole of reactive sites on the support were placed into a synthesis chamber and phosphoramidite nucleotides were added by standard chemical methods.
[0096] Following synthesis, the solid support was transferred to a 2 ml microcentrifuge tube where oligonucleotides were cleaved from the solid support by standard methods.
[0097] Oligonucleotides were purified by reverse-phase HPLC with a Hamilton PRP-1 column (1.0 cm.times.25 cm) using a linear gradient of from 5 to 50% acetonitrile over 40 min in 0.1 M triethyl-ammonium acetate (TEAAc) at pH 7.2. Samples were monitored at 260 nm and 494 nm and peaks corresponding to the fluorescent-labeled oligonucleotide species were collected, pooled, and lyophilized.
[0098] Oligonucleotide samples were dissolved in 200 mu.l of sterile water and precipitated by adding 1 ml of 2% LiClO 4 , followed by centrifugation at 10,000 g for 10 min. The supernatant was decanted and the pellet washed with 10% aqueous acetone.
[0099] Oligonucleotides were repurified by ion exchange HPLC using a 40 min linear gradient of 0% to 50% 1 M LiCl in 0.1 M TRIS buffer. Samples were monitored at 260 nm and 494 nm and peaks corresponding to the dual-labeled oligonucleotide species were collected, pooled, precipitated with 2% LiClO 4 , and lyophilized.
[0100] Compound identities were verified by mass spectroscopy using a Voyager-DE BioSpectrometry workstation by known methods.
[0101] The oligonucleotides were suspended in HPLC grade water at 400 nM concentration. The absorbance spectra were measured in 10 mM Tris pH 8.0, 1 mM EDTA (TE buffer) with a sub-micro quartz cuvette having a 1-cm path length in a Hewlett Packard Model 8453 spectrophotometer (Hewlett Packard, Palo Alto, Calif.). Optical absorbance density was recorded from 200 to 750 nm for each oligonucleotide. Individual absorbance spectra are shown in FIG. 1 .
[0102] The data in this example shows that the anthraquinone (UQ2) absorption spectrum is broad, ranging from about 500 to about 700 nm. This absorbance range overlaps the fluorescence emission range of many fluorophores commonly used in molecular biology applications. UQ2 can be used to quench the fluorescence of at least the following dyes: fluorescein, tetrachlorofluoroscein, hexachlorofluoroscein, Cy3, tetramethylrhodamine, Cy3.5, carboxy-x-rhodamine, Texas Red, Cy5, Cy5.5.
Example 17
[0103] This example demonstrates the use of anthraquinone-quenched fluorescent probes to detect PCR amplified DNA.
[0104] Fluorescence-quenched probes can be employed to detect amplified target nucleic acid sequence during a PCR reaction. In this assay, a fluorescence-quenched probe that anneals to the 3′ side of an amplification primer is degraded by the nuclease activity of Taq DNA polymerase during a round of polymerization. Fluorescence can then be detected during the PCR reaction as the probe is degraded and the quencher and fluorophore are separated.
[0105] Oligonucleotide primers and probes were synthesized as in Example 16 with the exception that with Cy5 containing probes, deprotection was with 1:1:2 t-BuNH 2 :MeOH:H 2 O and samples were incubated for 4 h at 65° C. The supernatant was removed and the CPG was washed with 1 ml of H 2 O and supernatants were pooled and dried. Fluorophores were added to the 5′ nucleotide by standard methods. Primers, probes, and target nucleic acids are shown in Table 1 below. Probes used are SEQ ID No. 4, 5, 6, 7, and 8. Primers used are SEQ ID No. 9 and 10. The target nucleic acid is SEQ ID No. 11, a 220 basepair (bp) amplicon derived from the murine bHLH protein Ptfl-p48 gene (Genbank #AF298116), cloned into the pCRII-TOPO vector (Invitrogen, Carlsbad, Calif.), and is hereafter referred to as the “p48-gene target”.
[0000]
TABLE 1
Probes:
6FAM-ACCCGTTCACCCTCCCCCAG-UQ2
SEQ ID No. 4
6FAM-ACCCGTTCACCCTCCCCCAG-6Tamra
SEQ ID No. 5
6FAM-ACCCGTCACCCTCCCCCAG-QSY7
SEQ ID No. 6
TR-ACCCGTTCACCCTCCCCCAG-UQ2
SEQ ID No. 7
Cy5-ACCCGTFfCACCCTCCCCCAG-UQ2
SEQ ID No. 8
Forward Primer: MP48 F968
CAGAAGGTTATATCTGCCATCG
SEQ ID No. 9
Reverse Primer: MP48 R1187
CTCAAAGGGTGGTTCGTTCTCT
SEQ ID No. 10
Target Amplicon
(SEQ ID No. 11)
Forward Primer F968 Probe
CAGAAGGTTTATCATCTGCCATCG AGGC ACCCGTTCACCCTCCCCCAG TGACCCGGATT
ATGGTCTCCCTCCTCTTGCAGGGCACTCTCTTTCCTGGACTGATGAAAAACAGCTCAAA
GAACAAAATATCATCCGTACAGCTAAAGTGTGGACCCCAGAGGACCCCAGAAAACTCAA
CAGTCAAATCTTTCGACAACAT AGAGAACGAACCACCCTTTGAG
Reverse Primer R1187
[0106] PCR amplification was done using the Stratagene (La Jolla, Calif.) Brilliant Plus Quantitative PCR core Reagent Kit according to the manufacturer's directions. Reactions were carried out in a 25 mu.L volume and comprised 200 nM each of the amplification primers and fluorescent quenched probe and about 1000 copies of the target DNA. Cycling conditions were 50° C. for 2 min, 95° C. for 10 min, then 40 cycles of 2-step PCR with 95° C. for 15 sec and 60° C. for 1 min. PCR and fluorescence measurements were done using an ABI Prism™ 7700 Sequence Detector (Applied Biosystems Inc., Foster City, Calif.). All data points were performed in triplicate. Results for different probes are presented in Table 2 below. The cycle threshold (Ct) value is defined as the cycle at which a statistically significant increase in fluorescence is detected above background. Typically, a lower Ct value is indicative of a higher concentration of target DNA. However, in this example, where the amount of target DNA is held constant the Ct value of a given oligonucleotide is indicative of probe sensitivity. The assays were performed using an identical amount of input target DNA (1.times.10.sup.3 copies of the p48-gene target plasmid). Table 2 shows that all oligonucleotides provided similar Ct values and therefore function similarly.
[0000]
TABLE 2
Ct values for PCR Assays
Avg.
Ct
Probe
Reporter-Quencher
Value
SEQ ID No. 4
6FAM-ACCCGTTCACCCTCCCCCAG-UQ2
27.64
SEQ ID No. 5
6FAM-ACCCGTTCACCCTCCCCCAG-
27.67
6Tamra
SEQ ID No. 6
6FAM-ACCCGTTCACCCTCCCCCAG-QSY7
28.01
[0107] Relative fluorescence levels collected during PCR for each probe were graphically plotted against cycle number and are shown in FIG. 2 . All curves superimposed and could not be distinguished, indicating that each of the 3 quenching groups tested were suitable quenchers for the fluorescein (6FAM) reporter dye. This example demonstrates that probe compositions comprising the new anthraquinone quenchers of the invention perform well in a quantitative real-time PCR assay and are functionally equivalent to probes that contain other quencher moieties.
[0108] Additional fluorescence-quenched probes were synthesized having a Texas Red (TR) reporter dye (SEQ ID No. 7) and a Cy5 reporter dye (SEQ ID No. 8) and the anthraquinone quencher. Texas Red probes could not be made using 6Tamra quencher as was previously done for the 6Fam probe (SEQ ID NO 5) because 6Tamra does not quench the TR reporter dye. Cy5 probes could not be made using either 6Tamra or QSY7 quencher as neither group will quench the Cy5 reporter dye.
[0109] PCR reactions were carried out as described above except that multiple concentrations of target (SEQ ID No. 11) were assayed and only a single probe was tested in a given experiment (SEQ ID Nos. 7 or 8). A dilution series of input target DNA was made to include 1.times.10.sup.8, 1.times.10.sup.7, 1.times.10.sup.6, 1.times.10.sup.4, and 1.times.10.sup.2 copies of target. All data points were performed in triplicate. Cycling conditions employed were as follows: 50° C. for 2 min and 95° C. for 10 min followed by 40 cycles of 2-step PCR with 95° C. for 15 sec and 60° C. for 1 min. PCR and fluorescence measurements were done using a BioRad iCycler IQ™ Real-time PCR Detection System (Bio-Rad Laboratories, Hercules, Calif.). For the Texas Red probe, a 575 nm (30 nm bandpass) excitation filter and a 625 nm (30 nm bandpass) detection filter were used. Results are shown in FIG. 3 for the Texas Red probe (SEQ ID No. 7). For the Cy5 probe, a 635 nm (30 nm bandpass) excitation filter and a 680 nm (30 nm bandpass) detection filter were used. Results are shown in FIG. 4 for the Cy5 probe (SEQ ID No. 8).
[0110] These results demonstrate that the new anthraquinone quencher is useful with red (Texas Red, emission 610 nm) and far-red dyes (Cy5, emission 667 nm). Further, use of the anthraquinone quencher enables use of far-red reporter dyes like Cy5 as fluorescent dyes in this range are not effectively quenched in linear probe configuration by other existing quencher groups.
[0111] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
[0112] The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better describe the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
[0113] 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, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. 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. | The invention provides novel anthraquinone compositions that are useful as broad-spectrum quenchers of fluorescence and provides methods for making and using them. The anthraquinone quenchers can be conjugated to a variety of biologically relevant compounds, including lipids, nucleic acids, polypeptides, and more specifically antigens, steroids, vitamins, drugs, haptens, metabolites, toxins, environmental pollutants, amino acids, peptides, proteins, nucleotides, oligonucleotides, polynucleotides, carbohydrates, and their analogs. The invention also provides kits comprising, in one or more containers, at least one anthraquinone quencher dye composition of the present invention, and instructions for using that composition. | 2 |
BACKGROUND AND OBJECTS OF THE INVENTION
1. Field of the Invention
The present invention relates generally to mechanical cork pullers of the type wherein the puller shaft is in meshed relationship with a pair of toothed sectors formed on rotatably mounted lever arms which serve to drive the puller shaft upwardly to raise and remove a cork, and relates more particularly to certain new and useful improvements in the construction of such mechanical cork pullers and in their method of manufacture.
2. Description of the Prior Art
All mechanical cork pullers of the aforementioned type heretofore known have been constructed with either a pin, rivet, screw or eyelet extending between opposed pairs of support ears, about which the lever arms rotate upon operation of the device.
A representative example of the previous constructions of these mechanical cork puller devices is illustrated in FIG. 1 of the accompanying drawings, which is more fully described hereinafter.
The aforesaid known prior constructions of the mechanical cork pullers are disadvantageous for several reasons. Firstly, as illustrated in FIG. 1 of the accompanying drawings, the use of a pin, rivet, etc., for the mounting of the lever arms requires that the holes be drilled through the support ears and results in the appearance of unsightly circles or rivet or screw heads on the outer surfaces of the ears at the pivot points for the rotatable lever arms.
Secondly, the prior known constructions of mechanical cork pullers tend to develop locking, jamming or sticking problems. This is believed due to imprecise location and/or direction of the holes drilled through the support ears, or due to imprecise manufacture or insertion of the pins, rivets or eyelets, or, in the case of screws, excessive tightening of the screws, causing the support ears to inhibit freedom of movement of the lever arms.
In addition, manufacture and assembly of these prior known constructions is complicated because it requires (1) a precision drilling operation for the support ears, (2) a special tool and (3) a separate step for insertion of the pin, rivet, etc. through the ear holes, and (4) the separate manufacture or purchase of the pins, rivets, etc.
3. Objects of the Invention
It is therefore an object of this invention to provide, as an article of manufacture, a novel and improved mechanical cork puller.
Another object of this invention is to provide a novel and improved method of manufacture of a mechanical cork puller.
Another object of this invention is to provide a novel and improved mechanical cork puller and method of manufacture thereof which fully eliminate the disadvantages of known constructions for such devices and their method of manufacture.
Another object of this invention is to provide a novel and improved mechanical cork puller in which the outer surfaces of the support ears having lever arms pivotally mounted therebetween are unusually smooth and attractive.
Another object of this invention is to provide a novel and improved method of manufacture of mechanical cork pullers that is simple to perform and yet which provides a mechanical cork puller device that is exceptionally durable and free of any operative difficulties.
Objects and advantages of the invention are set forth in part herein and in part will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.
The invention consists in the novel parts, constructions, arrangements, combinations, steps, processes and improvements herein shown and described.
SUMMARY OF THE INVENTION
Briefly described, the mechanical cork puller of the present invention is characterized by the pivot means for the rotatable lever arms, which comprises one or more, preferably two, raised rib members formed on the inner surfaces of each opposed pair of support ears about which the lever arms pivot. Preferably, the inner surfaces of each pair of support ears have an inwardly diverging taper, with the outer ends fitting closely against the sides of the toothed sectors of the lever arms, while a loose fit is maintained adjacent the point of meshed engagement between the toothed sectors and the circumferential grooves on the cork puller shaft.
The method of manufacture of the mechanical cork puller of the present invention comprises, in the preferred embodiment, die casting a pair of spaced parallel rib members on the inner surfaces of the support ears along the entire length thereof from the tubular housing for the cork puller shaft to the desired outermost point. Also, the support ears are cast so that the inner surfaces of each opposed pair have an outwardly diverging taper. Thereafter, the inner portions of the rib members are shaved off to form a pair of ribs adapted to closely fit within the pivot hole of a lever arm and the outer ends of the support ears are bent toward each other to an intermediate position where their inner surfaces are approximately parallel. The lever arms are then forceably slidably inserted between each pair of opposed ears, thereby springing the ears apart, until the rib members are received by the pivot holes, whereupon the ears snap back to their aforesaid intermediate position where they fit loosely on either side of the lever arm. The outer ends of the support ears are then further bent toward each other to their final assembled position, where they fit closely against the sides of the lever arms, while retaining a loose fit at the ends thereof adjacent the tubular housing for the cork puller shaft.
In an alternate embodiment of the method of the invention, the outer ends of the opposed pairs of support ears are bent toward each other from the originally cast position to the final assembled position in a single bending step, and the lever arms are thereafter forceably slidably inserted therebetween.
It will be apparent from the foregoing general description that the objects of the invention specifically enumerated herein are accomplished by the invention as here embodied.
Thus, by mounting the lever arms for pivotal movement about rib members formed only on the inner surfaces of the support ears, the unsightly appearance of circles or rivet or screw heads is eliminated. Indeed, there is no visible sign at all of the pivot point on the outer surfaces of the support ears. These surfaces are completely smooth and are therefore unusually attractive.
The rib members forming the lever arm pivot support, in combination with an inwardly diverging taper between the respective opposed inner surfaces of the support ears, cooperate to provide free pivotal movement of the lever arm while maintaining positive meshing engagement thereof with the cork puller shaft. There is remarkable freedom from any of the tendencies to lock, jam or stick as are associated with the use of a pin, rivet, screw or eyelet in the prior constructions, and yet the lever arms are held in place about the rib members by a very strong retaining force.
Moreover, in addition to the foregoing improvements in the article, the method of manufacture of the invention is greatly simplified and less expensive to perform than previously known methods. Thus, there is no drilling operation for the support ears, no separate manufacture of the pin, rivet, screw or eyelet, and no special tool or step for inserting same through the ear holes. In addition, the simultaneous snap-in and locking assembly of the lever arms between the support ears is much more quickly and easily accomplished than the prior art assembly techniques.
In sum, the mechanical cork puller of the invention is exceedingly simple to construct and assemble, and yet surprisingly effective in durability and operation, and is unusually attractive in appearance.
It will be understood that the foregoing general description and the following detailed description as well are exemplary and explanatory of the invention but are not restrictive thereof.
The accompanying drawings, referred to herein and constituting a part hereof, illustrate a representative prior art construction for a mechanical cork puller, and also preferred embodiments of the article and method of manufacture of the present invention, and together with the description, serve to explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view in elevation, partly sectional, of a mechanical cork puller constructed according to the prior art, illustrating, in section, the lever arm mounted for pivotal movement about a pin or eyelet, and, in elevation, the lever arm mounted for pivotal movement about a screw, extending between a pair of opposed support ears;
FIG. 2 is a view in elevation, partly sectional, of a mechanical cork puller constructed in accordance with a preferred embodiment of the present invention, illustrating the lever arm mounted for pivotal movement about a pair of parallel rib members formed on the inner surface of each pair of opposed support ears and also illustrating the smooth, uninterrupted outer surface of the support ears at the pivot point for the lever arms;
FIG. 3 is a top plan view of the main body portion of the cork puller of FIG. 2 in the first stage of manufacture according to the method of the present inventon, the view illustrating the outwardly diverging taper of the inner walls of each pair of opposed support ears and, to a much lesser extent, the inwardly diverging taper of the opposed rib members formed on the inner surfaces of the support ears so as to approximate a parallel juxtaposition therebetween;
FIG. 4 is an enlarged fragmentary sectional view of the upper portion of the main body and one support ear of the cork puller of FIG. 2 in the second stage of manufacture according to the preferred method of the invention, the view illustrating a pair of parallel rib members formed on the inner surface of the support ear and also illustrating the rib members cut away so as to have a length adapted to closely fit within the pivot hole of the rotating lever arm;
FIG. 5 is a top plan view of the main body portion of the cork puller of FIG. 2 in the third stage of manufacture according to the preferred method of the invention, the view illustrating each opposed pair of support ears having their outer ends bent toward each other into an intermediate position, where the inner surfaces thereof are approximately parallel;
FIG. 6 is a top plan view, partly sectional, of the main body portion of the cork puller of FIG. 2 in the fourth stage of manufacture according to the preferred method of the invention, the view illustrating a rotating lever arm being forecably inserted between a pair of support ears bent to the intermediate position shown in FIG. 5, thereby temporarily spreading apart the support ears so as to permit the lever arm to pass between the rib members and to thereafter "snap" in place when the rib members are encompassed by the pivot hole of the lever arm and the toothed sector thereof is in meshed engagement with the circumferential grooves of the puller shaft;
FIG. 7 is a top plan view of the mechanical cork puller shown in FIG. 2 in its final assembled state, the view illustrating the rotating lever arms fixedly mounted for pivotal movement between opposed pairs of support ears with the rib members located within the pivot holes formed in the rotating lever arms and the support ears bent toward each other so that the inner surfaces thereof have an inwardly diverging taper, and also illustrating a loose fit between the lever arms and the support ears adjacent the cork puller shaft while a snug fit is obtained therebetween at the outer ends of the support ears; and
FIG. 8 is an enlarged fragmentary sectional view similar to FIG. 4, illustrating an alternative embodiment of the invention, wherein a single rib member is formed on each of the inner surfaces of the opposed support ears, the dotted lines illustrating the tapered portions formed during the casting operation and subsequently cut away so as to form the rib with a length adapted to closely fit within the pivot hole of the rotating lever arm.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring initially to FIG. 1 of the accompanying drawings, there is illustrated a representative construction of know prior art mechanical cork pullers, indicated generally by reference numeral 1.
These devices typically include a main body portion 2 having a circular open-ended base 3 adapted to rest upon the top rim of a corked bottle neck (not shown) from which strut members 4 extend upwardly, connecting at their upper ends to opposed pairs of spaced support ears 5, 6 (not shown) and 7 (not shown), 8, respectively (only one ear of each pair being shown), located on either side of a tubular housing 9 telescopically slidably receiving a cork puller shaft 10 therein. The cork puller shaft 10 includes a worm portion 11 to be embedded in the cork, a screw portion 12 comprising a plurality of parallel grooves 13 extending circumferentially about the shaft and, advantageously, a closed winged upper end 14 facilitating manual turning of the shaft and serving the dual purpose of a bottle cap opener. A lever arm 15 having a toothed sector 16 and pivot hole 17 is shown, for illustrative purposes, mounted for pivotal movement about an eyelet 18 extending between the pair of support ears 7, 8, and, as an alternative construction, pivoting about a screw 18' extending between the pair of support ears 5, 6. Each toothed sector 16 extends through a slot 19 in housing 9 into meshed engagement with the circumferentially extending grooves 13 of puller shaft 10.
To operate, the base 3 of the cork puller 1 is placed on the rim of a corked bottle neck and the puller shaft 10 is then turned to embed the worm portion thereof in the bottle cork, thereby pulling shaft 10 down and simultaneously causing lever arms 15 to rotate upwardly about pivot 18. Upon thereafter forceably rotating the lever arms 15 downwardly to their original position, the puller shaft 10 is thereby driven upwardly to raise and remove the cork from the bottle.
Referring now more particularly to the preferred embodiment of the article of manufacture of the present invention, best shown in FIGS. 2, 4 and 7 of the accompanying drawings, there is illustrated a mechanical cork puller, indicated generally by reference numeral 50, whose like parts to the previously described known constructions of such devices are designated by like numerals.
In accordance with the invention, cork puller 50 is provided with pivot means for the lever arms 15 which are not visible on the outer surfaces of the support ears 5, 6 and 7, 8, and which provides freedom of movement between the toothed sectors 16 of the lever arm 15 and the circumferentially grooved screw portion 12 of the puller shaft 10.
As here preferably embodied, the pivot means of the invention comprises a pair of parallel spaced rib members 52, 53 formed on the inner surfaces of each of the support ears 5, 6, 7, 8 and adapted to closely fit within the pivot hole 17 of rotating lever arms 15. In addition, as preferably embodied, each pair of support ears 5, 6 and 7, 8, respectively, are formed so as to have an inwardly diverging taper along their spaced inner surfaces 5a, 6a and 7a, 8a, respectively, providing a snug fit between the lever arms 15 and the support ears at the outer ends thereof (pivot point) while providing a loose fit where the toothed sectors 16 of the lever arms 15 mesh with the grooves 13 on the cork puller shaft 10.
Advantageously, rib members 52, 53 are formed integral with the support ears and are only slightly raised from the inner surfaces thereof, preferably a distance of no less than about 1/64 inch. It will, of course, be understood that the minimum height of ribs, 52, 53 must be a distance sufficient to securely hold the lever arms 15 against disengagement during normal usage and that the maximum height is governed by the distance that support ears 5, 6, 7, 8 may be spread apart without undue effort and still return to their original position.
Also advantageously, ribs 52, 53 are approximately equal in length to the width across the spaced ribs, the aforesaid length and width preferably being of a distance such that the ends 52a, 52b, 53a, 53b of the ribs 52, 53 form a square whose diagonal length is approximately equal to the diameter of the pivot hole 17 of lever arms 15.
In an alternative embodiment of the article of manufacture of the invention, illustrated in FIG. 8 of the accompanying drawings, the pivot means comprises only a single rib member 55. Here again, however, the length and width of rib 55 preferably are approximately equal and are of such a length that the diagonal thereof is approximately equal to the diameter of pivot hole 17 of lever arms 15.
Referring now more particularly to the method of manufacture of the present invention, in the preferred embodiment thereof illustrated in FIGS. 3-7 the main body portion 2 of cork puller 50 is initially die-cast from a standard diecasting metal, such as, e.g., zinc, with parallel spaced rib members 52, 53 cast in place as an integral part of the main body 2.
Advantageously, for ease of casting and simplicity of manufacture of the casting mold, ribs 52, 53, "as cast", extend along the entire length of the inner surface 5, 6, 7, 8 of the support ears to the desired outermost point, advantageously increasing in height to the preferred height of approximately 1/64 inch adjacent the outer ends thereof. Also for ease of casting, as best shown in FIG. 3, support ears 5, 6, 7, 8 are cast so that the respective opposed inner surfaces 5a, 6a and 7a, 8a thereof have an outwardly diverging taper. The space between inner surfaces 5a, 6a and 7a, 8a, respectively, adjacent slots 19 in housing 9 as cast is selected so as to permit the toothed sectors 16 of the lever arms 15 to loosely fit therebetween.
Upon completion of the die-casting operation, as best shown in FIG. 4, the inner ends 52' and 53' of the cast ribs 52, 53 are shaved away by a suitable cutting tool (not shown), such as, e.g. a knife blade mounted to the ram section of a suitable press machine, such as a power press or an arbor press (not shown). After cutting, ribs 52, 53 are of a length as previously described so as to closely fit within pivot hole 17 of lever arm 15.
As previously mentioned, it is preferred that two spaced ribs 52, 53 be cast, and this is primarily for the reason that there is less material present to be later shaved away, thereby easing the cutting operation. Nevertheless, the invention may be satisfactorily achieved with a single rib member 55, as shown in FIG. 8 and previously discussed hereinabove, it being understood that the casting and shaving operations are otherwise identical.
After casting and shaving, the outer ends of each pair of support ears 5, 6 and 7, 8 respectively, are then preferably bent toward each other until the inner surfaces 5a, 6a and 7a, 8a, respectively, are approximately parallel. The body 2 may then be suitably plated, if desired, and is then ready to receive the lever arms 15, which are formed in the usual manner.
Installation of lever arms 15 is best seen in FIG. 6, and this step constitutes suitably forceably slidably inserting the toothed sector portions 16 thereof into the spaces between support ears 5, 6 and 7, 8, respectively, thereby causing the ears to spring apart slightly as the portion 16 passes between the ribs 52, 53, until the teeth thereof are brought into meshed engagement with the grooves 13 of the outer shaft 10, at which point pivot hole 17 encompasses the ribs, whereupon the ears snap back to their original position, thereby locking the lever arms 15 in place. At this stage of preferred manufacture, the toothed sectors fit loosely between the support ears, although held securely in place by ribs 52, 53 within pivot hole 17.
Thereafter, in the preferred embodiment of the method of manufacture of the invention, the support ears 5, 6 and 7, 8, respectively, are subjected to a second bending operation so as to further bend the outer ends of the ears toward each other until they fit closely against the sides of the toothed sectors of the lever arms, while retaining a loose fit adjacent the puller shaft 10 and tubular housing 9.
As an alternate embodiment of the method of manufacture of the invention, the outer ends of the support ears 5, 6 and 7, 8, respectively, may be bent toward each other until the inner surfaces 5a, 6a and 7a, 8a, respectively, have in inwardly diverging taper in a single operation. Thereafter, in the manner previously described, the lever arms 15 may be suitably forceably slidably inserted between the opposed supporting ears 5, 6 and 7, 8, respectively.
Whether one or two bending steps are used, it has been found that the force required to insert the lever arms between the respective opposed supporting ears is not great and can be easily performed manually and yet, once the support ears have snapped back to their original position, the lever arms are held about the ribs 52, 53 by a very strong retaining force, and cannot thereafter be disengaged by manual force alone.
The invention in its broader aspects is not limited to the specific embodiments herein shown and described but departures may be made therefrom without departing from the principles of the invention and without sacrificing its chief advantages. | An improved mechanical cork puller wherein the pivot holes of the lever arms receive and pivot about one or more ribs formed on the inner surfaces of the opposed pairs of support ears, resulting in no visible sign of a pivot support on the outer surfaces of the support ears. The support ears have an inwardly diverging taper providing free meshing movement between the toothed sectors of the lever arms and the cork puller shaft. To manufacture, elongated rib members are initially die-cast on the inner surfaces of the support ears and thereafter cut away to the desired length to form the pivot support for the lever arms. As cast, the inner surfaces of the support ears diverge outwardly and thereafter the outer ends of the support ears are bent toward each other so that the inner surfaces thereof diverge inwardly. The lever arms are thereafter assembled by merely force fitting them into place between the support ears. | 8 |
This application is a 371 of PCT/US96/12584 filed Aug. 2, 1996, which claims the benefit of U.S. Provisional Application Ser. No. 60/001,794 filed Aug. 2, 1995 and Ser. No. 60/011,009 filed Feb. 2, 1996
FIELD OF INVENTION
The present invention relates to isooxazoles, oxazoles, thiazoles, isothiazoles and imidazoles, pharmaceutical compositions containing these compounds and their use as endothelin receptor antagonists.
Endothelin (ET) is a highly potent vasoconstrictor peptide synthesized and released by the vascular endothelium. Endothelin exists as three isoforms, ET-1, ET-2 and ET-3. [Unless otherwise stated "endothelin" shall mean any or all of the isoforms of endothelin]. Endothelin has profound effects on the cardiovascular system, and in particular, the coronary, renal and cerebral circulation. Elevated or abnormal release of endothelin is associated with smooth muscle contraction which is involved in the pathogenesis of cardiovascular, cerebrovascular, respiratory and renal pathophysiology. Elevated levels of endothelin have been reported in plasma from patients with essential hypertension, acute myocardial infarction, subarachnoid hemorrhage, atherosclerosis, and patients with uraemia undergoing dialysis.
In vivo, endothelin has pronounced effects on blood pressure and cardiac output. An intravenous bolus injection of ET (0.1 to 3 nmol/kg) in rats causes a transient, dose-related depressor response (lasting 0.5 to 2 minutes) followed by a sustained, dose-dependent rise in arterial blood pressure which can remain elevated for 2 to 3 hours following dosing. Doses above 3 nmol/kg in a rat often prove fatal.
Endothelin appears to produce a preferential effect in the renal vascular bed. It produces a marked, long-lasting decrease in renal blood flow, accompanied by a significant decrease in GFR, urine volume, urinary sodium and potassium excretion. Endothelin produces a sustained antinatriuretic effect, despite significant elevations in atrial natriuretic peptide. Endothelin also stimulates plasma renin activity. These findings suggest that ET is involved in the regulation of renal function and is involved in a variety of renal disorders including acute renal failure, cyclosporine nephrotoxicity, radio contrast induced renal failure and chronic renal failure.
Studies have shown that in vivo, the cerebral vasculature is highly sensitive to both the vasodilator and vasoconstrictor effects of endothelin. Therefore, ET may be an important mediator of cerebral vasospasm, a frequent and often fatal consequence of subarachnoid hemorrhage.
ET also exhibits direct central nervous system effects such as severe apnea and ischemic lesions which suggests that ET may contribute to the development of cerebral infarcts and neuronal death.
ET has also been implicated in myocardial ischemia (Nichols et al. Br. J. Pharm. 99: 597-601, 1989 and Clozel and Clozel, Circ. Res., 65: 1193-1200, 1989) coronary vasospasm (Fukuda et al., Eur. J. Pharm. 165: 301-304, 1989 and Luscher, Circ. 83: 701, 1991) heart failure, proliferation of vascular smooth muscle cells, (Takagi, Biochem & Biophys. Res. Commun.; 168: 537-543, 1990, Bobek et al., Am. J. Physiol. 258:408-C415, 1990) and atherosclerosis, (Nakaki et al., Biochem. & Biophys. Res. Commun. 158: 880-881, 1989, and Lerman et al., New Eng. J. of Med. 325: 997-1001, 1991). Increased levels of endothelin have been shown after coronary balloon angioplasty (Kadel et al., No. 2491 Circ. 82: 627, 1990).
Further, endothelin has been found to be a potent constrictor of isolated mammalian airway tissue including human bronchus (Uchida et al., Eur J. of Pharm. 154: 227-228 1988, LaGente, Clin. Exp. Allergy 20: 343-348, 1990; and Springall et al., Lancet, 337: 697-701, 1991). Endothelin may play a role in the pathogenesis of interstitial pulmonary fibrosis and associated pulmonary hypertension, Glard et al., Third International Conference on Endothelin, 1993, p. 34 and ARDS (Adult Respiratory Distress Syndrome), Sanai et al., Supra, p. 112.
Endothelin has been associated with the induction of hemorrhagic and necrotic damage in the gastric mucosa (Whittle et al., Br. J. Pharm. 95: 1011-1013, 1988); Raynaud's phenomenon, Cinniniello et al., Lancet 337: 114-115, 1991); Crohn's Disease and ulcerative colitis, Munch et al., Lancet, Vol. 339, p. 381; Migraine (Edmeads, Headache, February 1991 p 127); Sepsis (Weitzberg et al., Circ. Shock 33: 222-227, 1991; Pittet et al., Ann. Surg. 213: 262-264, 1991), Cyclosporin-induced renal failure or hypertension (Eur. J. Pharmacol., 180: 191-192, 1990, Kidney Int, 37: 1487-1491, 1990) and endotoxin shock and other endotoxin induced diseases (Biochem, Biophys. Res. Commun., 161: 1220-1227, 1989, Acta Physiol. Scand. 137: 317-318, 1989) and inflammatory skin diseases. (Clin Res. 41:451 and 484, 1993).
Endothelin has also been implicated in preclampsia of pregnancy. Clark et al. Am. J. Obstet. Gynecol. March 1992, p. 962-968; Kamor et al., N. Eng. J. of Med., Nov. 22, 1990, p. 1486-1487; Dekker et al., Eur J. Ob. and Gyn. and Rep. Bio. 40 (1991) 215-220; Schiff et al., Am. J. Ostet. Gynecol. February 1992, p. 624-628; diabetes mellitus, Takahashi et al., Diabetologia (1990) 33:306-310; and acute vascular rejection following kidney transplant, Watschinger et al., Transplantation Vol. 52, No. 4, pp. 743-746.
Endothelin stimulates both bone resorption and anabolism and may have a role in the coupling of bone remodeling. Tatrai et al. Endocrinology, Vol. 131, p. 603-607.
Endothelin has been reported to stimulate the transport of sperm in the uterine cavity, Casey et al., J. Clin. Endo and Metabolism, Vol. 74, No. 1, p. 223-225, therefore endothelin antagonists may be useful as male contraceptives. Endothelin modulates the ovarian/menstrual cycle, Kenegsberg, J. of Clin. Endo. and Met., Vol. 74, No. 1, p. 12, and may also play a role in the regulation of penile vascular tone in man, Lau et al., Asia Pacific J. of Pharm., 1991, 6:287-292 and Tejada et al., J. Amer. Physio. Soc. 1991, H1078-H1085. Endothelin also mediates a potent contraction of human prostatic smooth muscle, Langenstroer et al., J. Urology, Vol. 149, p. 495-499.
Thus, endothelin receptor antagonists would offer a unique approach toward the pharmacotherapy of hypertension, acute and chronic renal failure, ischemia induced renal failure, sepsis-endotoxin induced renal failure, prophylaxis and/or treatment of radio-contrast induced renal failure, acute and chronic cyclosporin induced renal failure, cerebrovascular disease, cerebrovascular spasm, subarachnoid hemorrhage, myocardial ischemia, angina, congestive heart failure, acute coronary syndrome, myocardial salvage, unstable angina, asthma, primary pulmonary hypertension, pulmonary hypertension secondary to intrinsic pulmonary disease, atherosclerosis, Raynaud's phenomenon, ulcers, sepsis, migraine, glaucoma, endotoxin shock, endotoxin induced multiple organ failure or disseminated intravascular coagulation, cyclosporin-induced renal failure and as an adjunct in angioplasty for prevention of restenosis, diabetes, diabetic retinopathy, retinopathy, diabetic nephropathy, diabetic macrovascular disease, atherosclerosis, preclampsia of pregnancy, bone remodeling, kidney transplant, male contraceptives, infertility and priaprism and benign prostatic hypertrophy.
SUMMARY OF THE INVENTION
This invention comprises compounds represented by Formula (I) and pharmaceutical compositions containing these compounds, and their use as endothelin receptor antagonists which are useful in the treatment of a variety of cardiovascular and renal diseases including but not limited to: hypertension, acute and chronic renal failure, cyclosporine induced nephrotoxicity, benign prostatic hypertrophy, pulmonary hypertension, migraine, stroke, cerebrovascular vasospasm, myocardial ischemia, angina, congestive heart failure, atherosclerosis, diabetic nephropathy, diabetic retinopathy, retinopathy, diabetic macrovascular disease, atherosclerosis and as an adjunct in angioplasty for prevention of restenosis.
This invention further constitutes a method for antagonizing endothelin receptors in an animal, including humans, which comprises administering to an animal in need thereof an effective amount of a compound of Formula (I).
In a further aspect the present invention provides a process for the preparation of a compound of Formula (I)).
DETAILED DESCRIPTION OF THE INVENTION
The compounds of this invention are represented by structural Formula (I): ##STR1## wherein Z is ##STR2## D is O or S; E is O, S or NR 15 ;
P is tetrazol-5-yl, CO 2 R 6 or C(O)N(R 6 )S(O) q R 10 ;
R a is independently hydrogen or C 1-6 alkyl;
R 1 is independently hydrogen, Ar, C 1-6 alkyl or C 1-6 alkoxy;
R 2 is Ar, C 1-8 alkyl, C(O)R 14 or ##STR3## R 3 and R 5 are independently R 13 OH, C 1-8 alkoxy, S(O) q R 11 , N(R 6 ) 2 , NO 2 , Br, F, I , Cl, CF 3 , NHCOR 6 , R 13 CO 2 R 7 , --X--R 9 --Y, --X(C(R 6 ) 2 )OR 6 , --(CH 2 ) m X'R 8 or --X(CH 2 ) n R 8 wherein each methylene group within --X(CH 2 ) n R 8 may be unsubstituted or substituted by one or two --(CH 2 ) n Ar groups;
R 4 is independently R 11 , OH, C 1-5 alkoxy, S(O) q R 11 , N(R 6 ) 2 , Br, F, I, Cl or NHCOR 6 , wherein the C 1-5 alkoxy may be unsubstituted or substituted by OH, methoxy or halogen;
R 6 is independently hydrogen or C 1-8 alkyl;
R 7 is independently hydrogen, C 1-10 alkyl, C 2-10 alkenyl or C 2-8 alkynyl, all of which may be unsubstituted or substituted by one or more OH, N(R 6 ) 2 , CO 2 R 12 , halogen or XC 1-10 alkyl; or R 7 is (CH 2 ) n Ar;
R 8 is independently R 11 , CO 2 R 7 , CO 2 C(R 11 ) 2 O(CO)XR 7 , PO 3 (R 7 ) 2 , SO 2 NR 7 R 11 , NR 7 SO 2 R 11 , CONR 7 SO 2 R 11 , SO 3 R 7 , SO 2 R 7 , P(O)(OR 7 )R 7 , CN, CO 2 (CH 2 ) m C(O)N(R 6 ) 2 , C(R 11 ) 2 N(R 7 ) 2 , C(O)N(R 6 ) 2 , NR 7 C(O)NR 7 SO 2 R 11 , OR 6 , or tetrazole which is substituted or unsubstituted by C 1-6 alkyl;
R 9 is independently a bond, C 1-10 alkylene, C 1-10 alkenylene, C 1-10 alkylidene, C 1-10 alkynylene, all of which may be linear or branched, or phenylene, all of which may be unsubstituted or substituted by one of more OH, N(R 6 ) 2 , COOH or halogen;
R 10 is independently C 1-10 alkyl, N(R 6 ) 2 or Ar;
R 11 is independently hydrogen, Ar, C 1-8 alkyl, C 2-8 alkenyl, C 2-8 alkynyl, all of which may be unsubstituted or substituted by one or more OH, CH 2 OH, N(R 6 ) 2 or halogen;
R 12 is independently hydrogen, C 1-6 alkyl, C 2-6 alkenyl or C 2-7 alkynyl;
R 13 is independently divalent Ar, C 1-10 alkylene, C 1-10 alkylidene, C 2-10 alkenylene, all of which may be unsubstituted or substituted by one or more OH, CH 2 OH, N(R 6 ) 2 or halogen;
R 14 is independently hydrogen, C 1-10 alkyl, XC 1-10 alkyl, Ar or XAr;
R 15 is independently hydrogen, Ar, C 1-6 alkyl, or XAr;
R 16 is independently C 1-6 alkyl or phenyl substituted by one or more C 1-6 alkyl, OH, C 1-5 alkoxy, S(O) q R 6 , N(R 6 ) 2 , Br, F, I, Cl, CF 3 or NHCOR 6 ;
X is independently (CH 2 ) n , O, NR 6 or S(O) q ;
X' is independently O, NR 6 or S(O) q ;
Y is independently CH 3 or X(CH 2 ) n Ar;
Ar is: ##STR4## naphthyl, indolyl, pyridyl, thienyl, oxazolidinyl, thiazolyl, isothiazolyl, pyrazolyl, triazolyl, tetrazolyl, imidazolyl, imidazolidinyl, thiazolidinyl, isoxazolyl, oxadiazolyl, thiadiazolyl, morpholinyl, piperidinyl, piperazinyl, pyrrolyl, or pyrimidyl; all of which may be unsubstituted or substituted by one or more Z 1 or Z 2 groups;
A is independently (C═O, or (C(R 6 ) 2 ) m ;
B is independently --CH 2 -- or --O--;
Z 1 and Z 2 are independently hydrogen, XR 6 , C 1-8 alkyl, (CH 2 ) q CO 2 R 6 , C(O)N(R 6 ) 2 , CN, (CH 2 ) n OH, NO 2 , F, Cl, Br, I, N(R 6 ) 2 , NHC(O)R 6 , O(CH 2 ) m C(O)NR a SO 2 R 16 , (CH 2 ) m OC(O)NR a SO 2 R 16 , O(CH 2 ) m NR a C(O)NR a SO 2 R 16 or tetrazolyl which may be substituted or unsubstituted by one or two C 1-6 alkyl, CF 3 or C(O)R 6 ;
m is independently 1 to 3;
n is independently 0 to 6;
q is independently 0, 1 or 2;
provided R 3 , R 4 and R 5 are not O--O(CH 2 ) n Ar or O--OR 6 ;
or a pharmaceutically acceptable salt thereof.
All alkyl, alkenyl, alkynyl and alkoxy groups may be straight or branched.
Halogen may be Br, Cl, F or I.
The compounds of the present invention may contain one or more asymmetric carbon atoms and may exist in racemic and optically active form. All of these compounds and diastereoisomers are contemplated to be within the scope of the present invention.
Preferred compounds are those wherein:
P is CO 2 R 6 ; more preferably P is CO 2 H.
R 1 is hydrogen.
R 2 is Ar, cyclohexyl or C 1-4 alkyl. More preferably R 2 is a group Ar wherein Ar is a group (a) or (b). In said group (a) or (b) Z 1 and Z 2 are independently hydrogen, CO 2 R 6 , (CH 2 ) n OH, C 1-4 alkyl or C 1-6 alkoxy, e.g. methoxy; A is preferably CH 2 , and one or both Bs are preferably O.
R 3 and R 5 are independently hydrogen, CO 2 R 6 , OH, C 1-8 alkoxy, C 1-8 alkyl, N(R 6 ) 2 , NO 2 , Br, F, Cl, I, R 13 CO 2 R 7 , X(CH 2 ) n R 8 , (CH 2 ) m X'R 8 , or X(C(R 6 ) 2 ) m OR 6 ;
In the context of the group R 3 and R 5 preferably do not represent hydrogen. In particular in the group R 3 preferably represents Br, Cl, C 1-8 alkoxy e.g. methoxy; X(CH 2 ) n R 8 , wherein X preferably represents O, n is 0, 1, or 2, and R 8 is preferably selected from:
CO 2 R 6 wherein R 6 is preferably hydrogen;
OR 6 wherein R 6 is preferably H;
tetrazolyl optionally substituted by C 1-8 alkyl e.g. ethyl;
CONR 7 SO 2 R 11 wherein R 7 is H or C 1-8 alkyl e.g. methyl, R 11 preferably is
C 1-8 alkyl (e.g. methyl, isopryl, or t-butyl) or phenyl optionally substituted by Br, Cl, F, C 18 alkyl e.g. methyl;
or R 8 is phenyl or pyridyl substituted by one or more Br, Cl, CO 2 H, CH 2 OH.
R 5 is C 1-8 alkoxy e.g. methoxy, or N(R 6 ) 2 wherein R 6 preferably is H or methyl.
R 4 is hydrogen, OH, C 1-5 alkoxy, N(R 6 ) 2 , Br, F, Cl, I, NHCOCH 3 , or S(O) q C 1-5 alkyl wherein the C 1-5 alkyl may be unsubstituted or substituted by OH, methoxy or halogen. R 4 is more preferably hydrogen;
R 6 is hydrogen or C 1-8 alkyl e.g. methyl and ethyl;
R 7 is hydrogen, C 1-10 alkyl, C 2-10 alkenyl or C 2-8 alkynyl, all of which may be unsubstituted or substituted by one or more OH, N(R 6 ) 2 , CO 2 R 12 , halogen, or R 7 is (CH 2 ) n Ar. When R 7 is (CH 2 ) n Ar, n is preferably zero or 1 and Ar is preferably phenyl substituted or unsubstituted by halogen or C 1-5 alkoxy.
R 11 is hydrogen, phenyl, pyridyl wherein the phenyl and pyridyl may be substituted or unsubstituted by one or two C 1-4 alkyl groups; C 1-8 alkyl, C 2-8 alkenyl, C 2-8 alkynyl, all of which may be substituted or unsubstituted by one or more OH, CH 2 OH, N(R 6 ) 2 , or halogen;
R 12 is hydrogen or C 1-6 alkyl.
R 13 is phenyl, pyridyl, or C 2-10 alkylene, all of which may be unsubstituted or substituted by one or more CO 2 R 6 , OH, CH 2 OH, N(R 6 ) 2 , or halogen;
R 15 is preferably hydrogen or C 1-6 alkyl e.g. ethyl, isopropyl, n-butyl, cyclopropylmethyl or cyclopropylethyl.
The preferred compounds are:
(E)-3-[1-n-Butyl-5-[2-(2-carboxyphenyl)methoxy-4-methoxyphenyl]-1H-imidazol-4-yl]-2-[(2-methoxy-4,5-methylenedioxy)phenylmethyl]-prop-2-enoic acid;
(E)-alpha-[[5-[2-[(2-carboxyphenyl)methoxy]-4-methoxyphenyl]isoxazol-4-yl]methylene]-6-methoxy-1,3-benzodioxole-5-propanoic acid;
(E)-alpha-[[3-[2-[(2-carboxyphenyl)methoxy]-4-methoxyphenyl]isoxazol-4-yl]methylene]-6-methoxy-1,3-benzodioxole-5-propanoic acid; and
(E)-alpha-[[3-Butyl-4-[2-[(2-carboxyphenyl)methoxy]-4-methoxyphenyl]isoxazol-5-yl]methylene]-6-methoxy-1,3-benzodioxole-5-propanoic acid.
Compounds of the Formula (Ie), ##STR5## in which R a is H and D is O, can be prepared by Knoevenagel condensation of a 3-formyl chromone of Formula (2) ##STR6## with a half acid of Formula (3), wherein R 16 is allyl ##STR7## in a solvent such as benzene at reflux, in the presence of piperidinium acetate with azeotropic removal of water using a Dean-Stark apparatus to afford an ester of Formula (4). ##STR8## Compounds of Formula (2) are commercially available or may be prepared by treatment of a phenol of Formula (5) ##STR9## with boron trifluoride etherate in acetic anhydride followed by treatment with Vilsmeier reagent in dimethyl formamide according to the procedure of Hogberg et al. (Acta Chem. Scand. 1984, B38, 359-366)
Reaction of compound (4) with hydroxylamine hydrochloride (NH 2 OH.HCl) in a suitable solvent such as aqueous ethanol at reflux and in the presence of a base such as sodium acetate provides a phenol of Formula (6). ##STR10## Alkylation of a phenol of Formula (6) using a bromide of Formula (7), wherein R 16 is allyl ##STR11## in the presence of a base such as sodium hydride in a solvent such as dimethylformamide affords a compound of Formula (8). ##STR12## Deprotection of diallyl ester of Formula (8) using triethylsilane in the presence of a catalytic amount of tetrakis(triphenylphosphine)palladium(0) in a suitable solvent such as tetrahydrofuran at reflux affords, after acidification with acetic acid, an acid of the Formula (Ie), wherein R a is H, P is CO 2 H and D is O.
Alternatively, compounds of Formula (Ie) can be prepared starting from the reaction of a keto ester of Formula (9), wherein R 16 is allyl ##STR13## with an acyl chloride of Formula (10) ##STR14## in the presence of a base such as sodium in a solvent such as benzene, to provide a compound of Formula (12) ##STR15## Compound of Formula (12) can be treated with hydroxylamine hydrochloride (NH 2 OH.HCl) in a suitable solvent such as pyridine at reflux, to provide an isoxazole of Formula (13). ##STR16## Conversion of an allyl ester of Formula (13) using triethylsilane in the presence of a catalytic amount of tetrakis(triphenylphosphine)palladium(0) in a suitable solvent such as tetrahydrofuran at reflux affords, after acidification with acetic acid an acid of the Formula (14). ##STR17## Compound of Formula (14) can be converted to the corresponding N-methyl-O-methylcarboxamide of Formula (15) ##STR18## upon treatment with methyl choroformate followed by N,O-dimethylhydroxylaine hydrochloride in the presence of a base such as N-methylpiperidine. Compound of Formula (15) can be treated with an organometallic reagent of Formula (16)
R.sup.a -M (16)
wherein R a is C 1-6 alkyl and M is either Li or MgCl, following the procedure of Nahm and Weinreb (Tetrahedron Lett. 1981, 39, 3815), to provide a compound of Formula (17), wherein R a is C 1-6 alkyl. ##STR19## Alternatively, a compound of Formula (17), wherein R a is H, can be obtained by treatment of carboxamide of Formula (15) with lithium aluminum hydride in a solvent such as anhydrous ether.
Reaction of compound of Formula (17) with the the lithium enolate of an ester of Formula (18), wherein R 16 is allyl ##STR20## generated by by treatment of (18) with lithium diisopropylamide at -78° C. under an inert atmosphere in a solvent such as tetrahydrofuran, provides an alcohol of Formula (19) ##STR21## Dehydration of compound of Formula (19) with acetic anhydride followed by treatment with a base such as 1,8-diazabicyclo[5.4.0]undec-7-ene provides a compound of Formula (20) ##STR22## Alternatively, reaction of compound (17), wherein R a is C 1-6 alkyl, with Lawesson's reagent [2,4-bis(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulfide] in a suitable solvent such as tetrahydrofuran affords a thione of Formula (21). ##STR23## Reaction of a compound of Formula (21) with a diazoester of Formula (22), wherein R 16 is allyl ##STR24## in refluxing tetrahydrofuran affords thiirane (23). ##STR25## A diazoester of Formula (22) can be prepared from the corresponding ester (18) by treatment with lithium diisopropylamide at -78° C. in a solvent such as anhydrous tetrahydrofuran, followed by the addition of ethyl formate to produce a formylated ester of structure (24). ##STR26## Compounds of Formula (24) can be treated with an arylsulfonylazide such as 4-carboxyphenylsulfonyl azide in the presence of a base such as triethylamine followed by treatment with a base such as aqueous potassium hydroxide to afford diazoesters of type (22).
Treatment of a thiirane of Formula (23) with trimethylphosphite at reflux in a solvent such as chloroform provides compounds of Formula (20), wherein R a is C 1-6 alkyl.
Deprotection of allyl ester of Formula (20) using triethylsilane in the presence of a catalytic amount of tetrakis(triphenylphosphine)palladium(0) in a suitable solvent such as tetrahydrofuran at reflux affords, after acidification with acetic acid, an acid of the Formula (Ie), wherein P is CO 2 H and D is O. ##STR27## Compounds of Formula (Id), wherein D is O, can be prepared starting from compound (12) by treatment with hydroxylamine hydrochloride (NH 2 OH.HCl) in a suitable solvent such as methanol, following the procedure of Nair and Wadodkar, Indian J. Chem., Sect B, 1982, 21, 573, to provide an isoxazole of Formula (25). ##STR28## Compound of Formula (25) can be subsequently converted to compounds of Formula (Id) following the same synthetic scheme as the one described above for the conversion of compound (13) to compound (Ie). ##STR29## Compounds of Formula (If) can be prepared starting by commercially available ketones of Formula (26) ##STR30## by reaction with diallyl oxalate of Formula (27) ##STR31## in the presence of a base such as sodium in a solvent such as allyl alcohol to produce a diketone of Formula (28), ), wherein R 16 is allyl. ##STR32## Reaction of a diketone of Formula (28) with hydroxylamine hydrochloride (NH 2 OH.HCl) in a suitable solvent such as pyridine at reflux provides an isoxazole of Formula (29). ##STR33## Deprotection of allyl ester of Formula (29) using triethylsilane in the presence of a catalytic amount of tetrakis(triphenylphosphine)palladium(0) in a suitable solvent such as tetrahydrofuran at reflux affords, after acidification with acetic acid, an acid of the Formula (30), ##STR34## which can be subsequently converted to the corresponding N-methoxy-N-methylamide of Formula (31) ##STR35## by treatment with methyl choroformate followed by N,O-dimethylhydroxylamine hydrochloride in the presence of a base such as N-methylpiperidine. Compound of Formula (31) can be treated with an organometallic reagent of Formula (16) to provide a compound of Formula (32), wherein R a is C 1-6 alkyl. ##STR36## Alternatively, compound (31) can be treated with with lithium aluminum hydride in a solvent such as diethyl ether to provide a compound of Formula (32), wherein R a is H.
Reaction of compound of Formula (32) with the the lithium enolate of an ester of Formula (18) provides an alcohol of Formula (33) ##STR37## Dehydration of compound of Formula (33) with acetic anhydride followed by treatment with a base such as 1,8-diazabicyclo[5.4.0]undec-7-ene provides a compound of Formula (34) ##STR38## Alternatively, reaction of compound (32), wherein R a is C 1-6 alkyl, with Lawesson's reagent in a suitable solvent such as tetrahydrofuran affords a thione of Formula (35), ##STR39## which can be treated with diazoester (22) in refluxing tetrahydrofuran to provide a thiirane of Formula (36). ##STR40## Treatment of a thiirane of Formula (36) with trimethylphosphite at reflux in a solvent such as chloroform provides compounds of Formula (34), wherein R a is C 1-6 alkyl.
Deprotection of allyl ester of Formula (34) using triethylsilane in the presence of a catalytic amount of tetrakis(triphenylphosphine)palladium(0) in a suitable solvent such as tetrahydrofuran at reflux affords, after acidification with acetic acid, an acid of the Formula (Ii), wherein P is CO 2 H and D is O. ##STR41## Compounds of Formula (Ig) can be prepared by a process which comprises treating an aryl halide of Formula (37), where Z is I, Br, or Cl ##STR42## with an appropriate alkyllithium reagent such as n-butyllithium in tetrahydrofuran by addition of a borate such as triisopropyl borate and acidic work up affords a boronic acid of Formula (38) ##STR43## Reaction of a boronic acid of Formula (38) with a compound of Formula (39) ##STR44## in the presence of a suitable base such as potassium carbonate with a palladium catalyst such as tetrakis(triphenylphosphine)palladium(0) in a mixture of toluene, ethanol and water at approximately 80-100° C. provides a compound of Formula of (40) ##STR45## Knoevenagel condensation of an aldehyde of Formula (40) with a half acid of Formula (3), wherein R 16 is C 1-8 alkyl, in a solvent such as benzene ar reflux, in the presence of piperidinium acetate with azeotropic removal of water using a Dean-Stark apparatus, affords an ester of Formula (41) ##STR46## Saponification of an ester of Formula (41) using aqueous sodium hydroxide in a solvent such as ethanol provides, after acidification with aqueous hydrochloric acid, an acid of Formula (Ig), wherein R a is H and P is CO 2 H.
The invention also is a process for preparing compounds of Formula (I) by:
(a) Reaction of a compound of Formula (II) ##STR47## or a protected form or precursor thereof (as defined hereinafter) with a compound of Formula (3) ##STR48## (wherein R 2 and R 16 are as defined for Formula (I) hereinabove); followed if necessary or desired by:
(b) conversion of one compound of Formula (I) into a different compound of Formula (I) e.g.
(i) when Formula (I) contains a group CO 2 R 6 , CO 2 R 7 or CO 2 R 12 wherein R 6 , R 7 or R 12 is alkyl, conversion to a corresponding compound where R 6 , R 7 or R 12 represents hydrogen;
(ii) when Formula (I) contains a hydroxy group (e.g. in R 3 , R 4 or R 5 ) conversion to a different group, e.g. a group (CH 2 )Ar where Ar is optionally substituted phenyl, by method well known in the art; and/or
(c) salt formation.
It will be appreciated by those skilled in the art that the substitutents R 3 , R 4 , R 5 , R 15 and Z 1 and Z 2 may be introduced at any appropriate stage of the synthesis, preferably at an early stage, using methods well known in the art. In some of the reactions depicted above, particularly those in the early stages of the overall synthesis, one or more of the substitutents may therefore represent a precursor for the eventual substituent. A precursor for any of the substitutents means a group which may be derivatised or converted into the desired group. It will be further appreciated that it may be necessary or desirable to protect certain of these substitutents(or their precursors) at various stages in the reaction sequence. Suitable precursors and protecting groups are well known to those skilled in the art, as are methods for their conversion or removal respectively.
In order to use a compound of the Formula (I) or a pharmaceutically acceptable salt thereof for the treatment of humans and other mammals it is normally formulated in accordance with standard pharmaceutical practice as a pharmaceutical composition.
Compounds of Formula (I) and their pharmaceutically acceptable salts may be administered in a standard manner for the treatment of the indicated diseases, for example orally, parenterally, sub-lingually, transdermally, rectally, via inhalation or via buccal administration.
Compounds of Formula (I) and their pharmaceutically acceptable salts which are active when given orally can be formulated as syrups, tablets, capsules and lozenges. A syrup formulation will generally consist of a suspension or solution of the compound or salt in a liquid carrier for example, ethanol, peanut oil, olive oil, glycerine or water with a flavouring or colouring agent. Where the composition is in the form of a tablet, any pharmaceutical carrier routinely used for preparing solid formulations may be used. Examples of such carriers include magnesium stearate, terra alba, talc, gelatin, agar, pectin, acacia, stearic acid, starch, lactose and sucrose. Where the composition is in the form of a capsule, any routine encapsulation is suitable, for example using the aforementioned carriers in a hard gelatin capsule shell. Where the composition is in the form of a soft gelatin shell capsule any pharmaceutical carrier routinely used for preparing dispersions or suspensions may be considered, for example aqueous gums, celluloses, silicates or oils and are incorporated in a soft gelatin capsule shell.
Typical parenteral compositions consist of a solution or suspension of the compound or salt in a sterile aqueous or non-aqueous carrier optionally containing a parenterally acceptable oil, for example polyethylene glycol, polyvinylpyrrolidone, lecithin, arachis oil, or sesame oil.
Typical compositions for inhalation are in the form of a solution, suspension or emulsion that may be administered as a dry powder or in the form of an aerosol using a conventional propellant such as dichlorodifluoromethane or trichlorofluoromethane.
A typical suppository formulation comprises a compound of Formula (1) or a pharmaceutically acceptable salt thereof which is active when administered in this way, with a binding and/or lubricating agent, for example polymeric glycols, gelatins, cocoa-butter or other low melting vegetable waxes or fats or their synthetic analogues.
Typical transdermal formulations comprise a conventional aqueous or non-aqueous vehicle, for example a cream, ointment, lotion or paste or are in the form of a medicated plaster, patch or membrane.
Preferably the composition is in unit dosage form, for example a tablet, capsule or metered aerosol dose, so that the patient may administer to themselves a single dose.
Each dosage unit for oral administration contains suitably from 0.1 mg to 500 mg/Kg, and preferably from 1 mg to 100 mg/Kg, and each dosage unit for parenteral administration contains suitably from 0.1 mg to 100 mg, of a compound of Formula (I) or a pharmaceutically acceptable salt thereof calculated as the free acid. Each dosage unit for intranasal administration contains suitably 1-400 mg and preferably 10 to 200 mg per person. A topical formulation contains suitably 0.01 to 1.0% of a compound of Formula (I).
The daily dosage regimen for oral administration is suitably about 0.01 mg/Kg to 40 mg/Kg, of a compound of Formula (I) or a pharmaceutically acceptable salt thereof calculated as the free acid. The daily dosage regimen for parenteral administration is suitably about 0.001 mg/Kg to 40 mg/Kg, of a compound of the Formula (I) or a pharmaceutically acceptable salt thereof calculated as the free acid. The daily dosage regimen for intranasal administration and oral inhalation is suitably about 10 to about 500 mg/person. The active ingredient may be administered from 1 to 6 times a day, sufficient to exhibit the desired activity.
No unacceptable toxicological effects are expected when compounds of the invention are administered in accordance with the present invention.
The biological activity of the compounds of Formula (I) are demonstrated by the following tests:
I. Binding Assay
A) CHO cell membrane preparation.
CHO cells stably transfected with human ETA and ETB receptors were grown in 245 mm×245 mm tissue culture plates in Dulbecco's modified Eagle's medium supplemented with 10% fetal bovine serum. The confluent cells were washed with Dulbecco's phosphate-buffered saline containing a protease inhibitor cocktail (5 rrm EDTA, 0.5 mM PMSF, 5 ug/ml of leupeptin and 0.1 U/mil of aprotinin) and scraped in the same buffer. After centrifugation at 800× g, the cells were lysed by freezing in liquid nitrogen and thawing on ice followed by homogenization (30 times using a glass dounce homogenizer) in lysis buffer containing 20 mM Tris HCI, pH 7.5, and the protease inhibitor cocktail. After an initial centrifugation at 800× g for 10 min to remove unbroken cells and nuclei, the supernatants were centrifuged at 40,000× g for 15 min and the pellet was resuspended in 50 mM Tris HCI, pH 7.5, and 10 mM MgCl 2 and stored in small aliquots at -70° C. after freezing in liquid N 2 . Protein was determined by using the BCA method and BSA as the standard.
(B) Binding studies.
[ 125 I]ET-1 binding to membranes prepared from CHO cells was performed following the procedure of Elshourbagy et al. (1993). Briefly, the assay was initiated in a 100 ul volume by adding 25 ul of [ 125 I]ET-1 (0.2-0.3 nM) in 0.05% BSA to membranes in the absence (total binding) or presence (nonspecific binding) of 100 nM unlabeled ET-1. The concentrations of membrane proteins were 0.5 and 0.05 ug per assay tube for ETA and ETB receptors, respectively. The incubations (30° C., 60 min) were stopped by dilution with cold buffer (20 mM Tris HCI, pH 7.6, and 10 mM MgCl 2 ) and filtering through Whatman GF/C filters (Clifton, N.J.) presoaked in 0.1% BSA. The filters were washed 3 times (5 ml each time) with the same buffer by using a Brandel cell harvester and were counted by using a gamma counter at 75% efficiency.
The following examples are illustrative and are not limiting of the compounds of this invention.
EXAMPLE 1
(E)-Ethyl alpha-[[3-[4-methoxy-2-[[2-(methoxycarbonyl)phenyl]methoxy]-phenyl]isoxazol-4-yl]methylene]-6-methoxy-1 ,3-benzodioxole-5-propanoate
a) (E)-Ethyl 6-Methoxy-alpha-[(7-methoxy-4-oxo-4H-1-benzopyran-3-yl)methylene]-1 ,3-benzodioxole-5-propanoate
A solution of 3-formyl-7-methoxychromone (0.67 g, 3.3 mmol) and ethyl hydrogen 2-[(6-methoxy-3,4-methylenedioxy)benzyl]malonate (0.89 g, 3.0 mmol) in benzene (30 mL) was treated with piperidine (0.15 mL, 1.5 mmol) followed by acetic acid (0.085 mL, 1.5 mmol). The reaction was stirred at reflux equipped with a Dean Stark apparatus for 2 h. The mixture was cooled then extracted with EtOAc (200 mL). The organic extract was washed successively with saturated NaHCO 3 and brine, dried (MgSO 4 ) and concentrated under vacuum. The resulting residue was purified by column chromatography (silica gel, EtOAc/hexane, gradient 75:25 to 70:30) to afford a material consisting of a 1.2:1 mixture of E:Z enoates as an oil (1.02 g, 78%). Recrystallization of this material from ethanol affords the title compound as the E-isomer, exclusively. Data for the the E-isomer: mp 140-141° C.; MS (ESI) t/z 439 (M+H) + . Anal. Calcd for C 24 H 22 O 8 : C, 65.75; H, 5.06. Found: C, 65.56; H, 4.99.
b) (E)-Ethyl (E)-alpha-[[3-(2-hydroxy-4-methoxyphenyl)isoxazol-4-yl]methylene]-6-methoxy-1,3-benzodioxole-5-propanoate
A solution of the compound of Example 1 (a) (0.701 g, 1.6 mmol of a 1:1 E:Z mixture), hydroxylamine hydrochloride (0.222 g, 3.2 mmol) and sodium acetate trihydrate (0.870 g, 6.4 mmol) in a mixture of 9:1 EtOH:H 2 O(32 mL) was stirred at reflux for 1 h. The reaction mixture was cooled and subsequently partitioned between EtOAc (150 mL) and aqueous pH 7 buffer. The organic extract was washed with brine, dried (Na 2 SO 4 ) and concentrated under vacuum. The resulting residue was purified by column chromatography (silica gel, CH 2 Cl 2 /hexane/EtOAc, 90:5:5 to 80:10:10) to afford the title compound (245 mg, 34%), that crystallized upon standing. mp 122-123.5° C. MS (ESI) m/z 454 (M+H) + .
c) (E)-Ethyl alpha-[[3-[4-methoxy-2-[[2-(methoxycarbonyl)phenyl]methoxy]-phenyl]isoxazol-4-yl]methylene]-6-methoxy-1,3-benzodioxole-5-propanoate
A solution of the compound of Example 1(b) (0.252 g, 0.58 mmol) in DMF (1.5 mL) was added dropwise to a slurry of NaH (0.022 g, 0.93 mmol) in DMF (1.4 mL) at room temperature. The reaction was stirred for 3 min at which time was added methyl 2-(bromomethyl)benzoate (0.21 g, 0.93 mmol) and stirring continued for 1 h at room temperature. The mixture was quenched with aqueous pH 7 buffer, then diluted with EtOAc. The organic extract was washed with brine, dried (Na 2 SO 4 ) and concentrated under vacuum. The resulting residue was purified by column chromatography (silica gel, 75:25 hexane/EtOAc) to afford the title compound (84.5 mg, 24%) as a white solid. mp 135-137° C. MS (ESI) m/z 602 (M+H) + .
EXAMPLE 2
(E)-3-[1-n-Butyl-5-[2-(2-carboxyphenyl)methoxy-4-methoxyphenyl]-1H-imidazol-4-yl]-2-[(2-methoxy-4,5-methylenedioxy)phenylmethyl]-2-propenoic acid
a) Ethyl 2-amino-2-cyanoacetate
To aluminum foil (25 g) was added a solution of mercury(II) chloride (10 g, 0.37 mol) in water (1 L). The mixture was swirled for 5 min, and then the turbid solution was decanted off. The resulting aluminum amalgam was washed successively with water, methanol and diethyl ether. To amalgam suspended in diethyl ether (500 mL) at 0° C., was added a solution of ethyl 2-hydroxyimino-2-cyanoacetate (100 g, 0.70 mol) in diethyl ether (300 mL), followed by water (50 mnL), maintaining a gentle reflux. After 1 h of stirring, the mixture was filtered and the filtrate was washed with water, brine and dried (Na 2 SO 4 ). Removal of the solvent gave the title compound as a white solid (67 g, 74%). 1 H NMR (250 MHz, CD 3 OD)δ 4.45 (m, 2H), 2.49 (s, 1H), 1.38 (m, 3H).
b) Ethyl 5-amino-1-n-butyl-1H-imidazole-4-carboxylate
A solution of ethyl 2-amino-2-cyanoacetate (0.20 g, 1.56 mmol) and triethyl formate (0.30 mL, 1.72 mmol) in acetonitrile (5 mL) was refluxed for 1 h. After concentrating the residue was dissolved in a solution of acetonitrile (5 mL) and n-butylamine (0.17 mL, 1.72 mmol). The resulting mixture was stirred at reflux for 1 h. The solvents were removed under reduced pressure and the residue was partitioned between water and ethyl acetate. The organic layer was separated and washed with brine and dried (Na 2 SO 4 ). After removing the solvent under reduced pressure, flash chromatography (1:1 ethyl acetate/hexane) of the residue gave 0.12 g, 40% of the title compound as an oil: 1 H NMR (250 MHz, CDCl 3 )δ 6.97 (s, 1H), 5.10 (s, 2H), 4.31 (q, 2H), 3.75 (t, 2H), 1.65 (m, 2H), 1.35 (m, 5H), 0.97 (t, 3H); MS(ESI) m/e 212.2 [M+H] + .
c) Ethyl 5-bromo-1-n-butyl-1H-imidazole-4-carboxylate
To a solution of ethyl 5-amino-1-n-butyl-1H-imidazole-4-carboxylate (0.05 g, 0.24 mmol) in bromoform (5 mL) was added butyl nitrite (0.10 mL, 0.71 mmol). The reaction mixture was stirred at reflux for 5 h. After an aqueous work up, extracting with ethyl acetate, the combined organic extracts were washed with brine and dried (Na 2 SO 4 ). After removing the solvent under reduced pressure, flash column chromatography (1:1 ether/hexane) of the residue gave the title compound as an oil (0.03 g, 46%). 1H NMR (250 MHz, CDCl 3 )δ 7.50 (b, 1H), 4.41 (q, 2H), 3.95 (t, 2H), 1.70 (quintet, 2H), 1.40 (m, 5H), 1.00 (t, 3H).
d) Ethyl 5-(2-methoxymethoxy-4-methoxyphenyl)-1-n-butyl-1H-imidazole-4-carboxylate
A mixture of ethyl 5-bromo-1-n-butyl-1H-imidazole-4-carboxylate (0.10 g, 0.37 mmol), 2-methoxymethoxy-4-methoxyphenylboronic acid (0.16 g, 0.73 mmol), sodium carbonate (0.08 g, 0.73 mmol) and tetrakis(triphenylphosphine)palladium(0) (0.04 g) in 12 mL of toluene/ethanol/water (10/1/1) was stirred at reflux for 24 h. After an aqueous work up, extracting with ethyl acetate (3×20 mL), the combined organic extracts were washed with brine and dried (Na 2 SO 4 ). After removing the solvent under reduced pressure, flash column chromatography (1:1 ethyl acetate/hexane) of the residue afforded the title compound as an oil (0.06 g, 46%). 1 H NMR (250 MHz, CDCl 3 )δ 7.53 (s, 1H), 7.09 (d, 1H), 6.75 (d, 1H), 6.60 (dd, 1H), 5.05 (q, 2H), 4.21 (q, 2H), 3.85 (s, 3H) 3.80 (t, 2H), 3.30 (s, 3H) 1.60 (quintet, 2H), 1.30 (m, 5H), 0.80 (t, 3H).
e) 1-n-Butyl-4-hydroxymethyl-5-(2-methoxymethoxy-4-methoxyphenyl)-1H-imidazole
To a solution of ethyl 1-n-butyl-5-(2-methoxymethoxy-4-methoxyphenyl)-1H-imidazole-4-carboxylate (0.06 g, 0.17 mmol) in THF (5 mL) was added LAH (0.20 mL) at room temperature. The mixture was stirred for 2 h. After an aqueous work up, extracting with ethyl acetate (3×20 mL), the combined organic extracts were washed with brine and dried (Na 2 SO 4 ). After removing the solvent under reduced pressure, flash column chromatography (1:1 ethyl acetate/hexane) of the residue afforded the title compound as an oil (0.05 g, 96%). 1 H NMR (400 MHz, CDCl 3 )δ 7.53 (s, 1H), 7.19 (d, 1H), 6.85 (d, 1H), 6.65 (dd, 1H), 5.05 (d, 2H), 4.41 (dd, 2H), 3.85 (s, 3H) 3.80 (t, 2H), 3.45 (s, 3H) 3.23 (b, 1H), 1.55 (quintet, 2H), 1.25 (quintet, 2H), 0.83 (t, 3H).
f) 1-n-Butyl-5-(2-methoxymethoxy-4-methoxyphenyl)-1H-imidazole-4-carboxaldehyde
To a solution 1-n-butyl-4-hydroxymethyl-5-(2-methoxymethoxy-4-methoxyphenyl)-1H-imidazole (0.05 g, 0.16 mmol) in toluene (5 mL) was added manganese oxide (0.04 g, 0.47 mmol). The mixture was stirred for 5 h at room temperature. The mixture was filtered and the filtrate was evaporated to dryness. Flash column chromatography (1:4 ethyl acetate/hexane) of the residue afforded the title compound as an oil (0.05 g, 94%). 1 H NMR (250 MHz, CDCl 3 )δ 9.65 (s, 1H), 7.58 (s, 1H), 7.13 (d, 1H), 6.80 (d, 1H), 6.65 (dd, 1H), 5.05 (s, 2H), 3.90 (s, 3H) 3.80 (t, 2H), 3.35 (s, 3H), 1.55 (quintet, 2H), 1.25 (quintet, 2H), 0.83 (t, 3H).
g) Ethyl (E)-3-[1-n-butyl-5-[2-(2-methoxymethoxy)-4-methoxyphenyl]-1H-imidazol-4-yl]-2-[(2-methoxy-4,5-methylenedioxy)phenylmethyl]-2-propenoate
A solution of 1-n-butyl-5-(2-methoxymethoxy-4-methoxyphenyl)-H-imidazol-4-carboxaldehyde (0.40 g, 1.40 mmol), ethyl hydrogen 2-(2-methoxy-4,5-methylenedioxybenzyl) malonate (1.00 g, 3.50 mmol), piperidine(0.07 mL, 0.70 mmol) and acetic acid (0.04 mL, 0.70 mmol) in benzene (20 mL), equipped with a Dean-Stark apparatus, was stirred at reflux for 24 h. The solvent was removed under reduced pressure and the crude residue was dissolved in ethyl acetate and washed with 10% sodium carbonate solution, water and dried (Na 2 SO 4 ). After removing the solvent, flash column chromatography of the residue (silica gel, 50% ethyl acetate/hexane) yielded the title compound as a brown oil (0.24 g, 33%). 1 H NMR (250 MHz, CDCl 3 )δ 7.63 (s, 1H), 7.35 (s, 1H), 7.13 (d, 1H), 6.70 (d, 1H), 6.65 (m, 2H), 6.51 (m, 2H), 5.75 (s, 2H), 5.05 (s, 2H), 4.07 (q, 2H), 3.87 (s, 3H) 3.77 (t, 3H), 3.35 (s, 3H), 1.55 (quintet, 2H), 1.25 (quintet, 2H), 1.10 (t, 3H), 0.83 (t, 3H).
h) Ethyl (E)-3-[1-n-butyl-5-(2-hydroxy-4-methoxy)phenyl-1H-imidazol-4-yl]-2-[(2-methoxy-4,5-methylenedioxy)phenylmethyl]-2-propenoate
To a solution of the ethyl (E)-3-[1-n-butyl-5-(2-methoxymethoxy-4-methoxy-phenyl)-1H-imidazol-4-yl]-2-[(2-methoxy-4,5-methylenedioxy)phenylmethyl]-2-propenoate (0.20 g, 0.38 mmol) in ethanol (25 mL) was added a catalytic amount of concentrated HCl. After stirring at reflux for 5 h the solvent was removed under reduced pressure. The residue was dissolved in ethyl acetate and washed with sat'd. sodium bicarbonate and dried (Na 2 SO 4 ). After removing the solvent flash chromatography of the residue (silica gel, 50% ethyl acetate/hexane) gave the title compound as a brown oil (0.18 g, 87%). 1 H NMR (250 MHz, CDCl 3 )δ 7.53 (s, 1H), 7.35 (s, 1H), 7.00 (d, 1H), 6.60 (d, 1H), 6.55 (m, 2H), 6.51 (m, 2H), 5.85 (s, 2H),4.39 (dd, 2H), 4.07 (q, 2H), 3.87 (s, 3H) 3.77 (t, 3H), 1.50 (quintet, 2H), 1.15 (m, 5H), 0.83 (t, 3H).
i) Ethyl (E)-3-[1-n-butyl-5-[2-(2-methoxycarbonyl)phenylmethoxy-4-methoxyphenyl]-1H-imidazol-4-yl]-2-[(2-methoxy-4,5-methylenedioxy)phenylmethyl]-2-propenoate
To a solution of the ethyl (E)-3-[1-n-butyl-5-(2-hydroxy-4-methoxyphenyl)-1H-imidazol-4-yl]-2-[(2-methoxy-4,5-methylenedioxy)phenylmethyl]-2-propenoate (0.08 g, 0.16 mmol) and 2-methyl carboxylate benzylbromide (0.09 g, 0.38 mmol) in DMF (5 mL) was added sodium hydride (0.01 g, 0.47 mmol) at 0° C. The reaction stirred at room temperature for 4 h. After an aqueous work up, extracting with ethyl acetate (3×15 mL), the combined organic extracts were washed and dried (Na 2 SO 4 ). After removing the solvent under reduced pressure, flash column chromatography (1:1 ethyl acetate/hexane) of the residue afforded the title compound as an oil (0.05 g, 46%). 1 H NMR (250 MHz, CDCl 3 )δ 7.98 (d, 1H), 7.60 (s, 1H), 7.48 (m, 2H), 7.35 (m, 2H), 7.15 (d, 1H), 6.65 (m, 2H), 6.50 (s, 2H), 5.83 (d, 2H), 5.45 (s, 2H),4.49 (q, 2H), 4.07 (q, 2H), 3.90 (s, 3H) 3.87 (s, 3H), 3.78 (s, 3H), 1.52 (quintet, 2H), 1.15 (m, 5H), 0.75 (t, 3H).
j) (E)-3-[1-n-Butyl-5-[2-(2-carboxyphenylmethoxy)-4-methoxyphenyl]-1H-imidazol-4-yl]-2-[(2-methoxy-4,5-methylenedioxy)phenylmethyl]-2-propenoic acid
To a solution of the ethyl (E)-3-[1-n-butyl-5-[2-(2-methoxycarbonyl)phenylmethoxy-4-methoxyphenyl]-1H-imidazol-4-yl]-2-[(2-methoxy-4,5-methylenedioxy)phenylmethyl]-2-propenoate (0.04 g, 0.07 mmol) in methanol (5 mL) was added a solution of sodium hydroxide (0.01 g, 0.25 mmol) in water (2 mL). The mixture stirred at reflux for 18 h. The methanol was removed under reduced pressure and the aqueous layer was washed with ether. The aqueous layer was acidified with concentrated HCl to pH 1 and extracted with ethyl acetate (3×50 mL). The combined organic extracts were washed with water, brine and dried (Na 2 SO 4 ). Removal of the solvent gave a white solid. Recrystallization from methanol yielded the title compound as a white solid (0.03 g, 72%): 1 H NMR (400 MHz CD 3 OD) 6 7.98 (d, 1H), 7.80 (s, 1H), 7.48 (s, 1H), 7.35 (m, 3H), 7.15 (d, 1H), 6.65 (m, 2H), 6.50 (s, 1H), 6.38 (s, 1H), 5.78 (s, 2H), 5.55 (dd, 2H), 4.10 (s, 2H), 3.85 (s, 3H) 3.65 (s, 3H), 1.50 (quintet, 2H), 1.11 (quintet, 2H), 0.70 (t, 3H); MS(ESI) m/e 615.2 [M+H] + ; mp: 178° C. (methanol); Anal. (C 34 H 34 N 2 O 9 ) calcd: C, 66.37; H, 5.58; N, 4.56. found: C, 66.10; H, 5.32; N, 4.19.
EXAMPLE 3
Formulations for pharmaceutical use incorporating compounds of the present invention can be prepared in various forms and with numerous excipients. Examples of such formulations are given below.
Inhalant Formulation
A compound of Formula I, (1 mg to 100 mg) is aerosolized from a metered dose inhaler to deliver the desired amount of drug per use.
______________________________________ PerTablets/Ingredients Tablet______________________________________1. Active ingredient 40 mg (Cpd of Form. I)2. Corn Starch 20 mg3. Alginic acid 20 mg4. Sodium Alginate 20 mg5. Mg stearate 1.3 mg 2.3 mg______________________________________
Procedure for tablets:
Step 1 Blend ingredients No. 1, No. 2, No. 3 and No. 4 in a suitable mixer/blender.
Step 2 Add sufficient water portion-wise to the blend from Step 1 with careful mixing after each addition. Such additions of water and mixing until the mass is of a consistency to permit its conversion to wet granules.
Step 3 The wet mass is converted to granules by passing it through an oscillating granulator using a No. 8 mesh (2.38 mm) screen.
Step 4 The wet granules are then dried in an oven at 140° F. (60° C.) until dry.
Step 5 The dry granules are lubricated with ingredient No. 5.
Step 6 The lubricated granules are compressed on a suitable tablet press.
Parenteral Formulation
A pharmaceutical composition for parenteral administration is prepared by dissolving an appropriate amount of a compound of formula I in polyethylene glycol with heating. This solution is then diluted with water for injections Ph Eur. (to 100 ml). The solution is then steriled by filtration through a 0.22 micron membrane filter and sealed in sterile containers. | Novel to isooxazoles, oxazoles, thiazoles, isothiazoles and imidazoles, pharmaceutical compositions containing these compounds and their use as endothelin receptor antagonists are described. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to clamping devices, commonly known as pipe clamps that are used to join together the flanged ends of two objects so that a fluid impervious seal is created between the opposing flanges. More particularly, the present invention relates to such clamping devices that are designed to provide a clamping tension that varies with changing conditions.
2. Description of the Prior Art
In the manufacture and processing of pharmaceutical products, dairy products and other materials that require a sanitary processing environment, it is common for materials to be stored and transported in stainless steel containers. Such stainless steel containers are manufactured by Eagle Stainless Container, Inc, of Ivyland Pa. The use of stainless steel is preferred because it enables the containers to be cleaned and sanitized in an autoclave or other harsh washing environment after they have been used. The stainless steel containers can therefore repeatedly be made sterile and can be used over and over again.
Since stainless steel containers are often used to house sterile materials or bioreactive materials, such containers typically do not contain threaded closures. Threaded closures provide confined areas between threads that may harbor contaminants or bioreactive material. Due to the physical shape of the threads, it is very difficult to properly clean threads to the sanitary standards needed. It is for this reason that threaded closures are generally not used. Rather, what is used are flanged caps.
Many stainless steel containers are manufactured with access ports that terminate with a flange connection. The flanged connection is a circular flange that radially extends from the neck of the access port. The access port can therefore be connected to a pipe with a similar flange connection or a cap that contains the proper sized flange connection. To join any two flanged connections together, the two flanges are placed in abutment so that the openings in the center of each of the flanges align. An O-ring or other sealer is placed between the two flanges. The flanges are then clamped together in a manner that compresses the O-ring and prevents the flanges from falling out of alignment.
In the prior art, there are many different types of clamping mechanisms that have been used to join together flanged connections. Typically, the clamps that have been used are annular in shape. Hinges are disposed along the annular structure to enable the annular structure to open. The clamps are opened and then closed over the span of the two adjoining flanges. The presence of the clamping device biases the adjoining flanges together and prevents the adjoining flanges from moving out of their aligned positions.
Prior art clamping devices with a single hinge are exemplified by U.S. Pat. No. 5,018,768 to Palatchy, entitled Pipe Coupling Hinge. Prior art clamping devices with multiple hinges are exemplified by U.S. Pat. No. 4,568,115 to Zimmerly, entitled Multi-Piece Pipe Clamp. Regardless of the number of hinges present, such prior art clamping devices typically contain a rocking bolt assembly that is pivotably connected to one end of the clamp. A wing nut is used to tighten the rocking bolt assembly. The wing nut passes over a slot that is positioned on the opposite end of the clamp. By tightening the wing nut, the diameter of the clamp can be reduced and the clamp can be tightened over the flanged connections.
In many applications, containers undergo severe temperature changes. For instance, a container may be filled at room temperature and then placed in a cryogenic environment, or vise versa. As the temperature of a container changes, the vapor pressure within the container changes and the forces on the cap of the container change. Additionally, as the container is moved into environments of differing temperatures, the temperature of the clamp used to hold a cap onto the container also changes. As a clamp experiences temperature changes, the metal of the clamp either expands or contracts. As such, a clamp that is very tight in one environment may become very loose in a different environment.
A need therefore exists for a new clamp design that is capable of providing a steady clamping pressure regardless of severe changes in temperature. This need is met by the present invention as it is described and claimed below.
SUMMARY OF THE INVENTION
The present invention is a clamping device that is used to maintain a consistent clamping pressure on a flanged connection despite changes in temperature and changes in internal pressure behind the flanged connection. The clamping device contains a plurality of arcuate segments. The first and the last of the arcuate segments contain base protrusions that align when the clamping device is closed. One of the base protrusions serves as the housing for a rocking bolt assembly. The rocking bolt assembly includes a threaded rod that joins to a shaft by a pivot. The threaded rod and shaft extend through a hole in the base protrusion. The shaft has an enlarged head that prevents the shaft and the threaded rod from passing through the hole. A wing nut engages the threaded rod and applies tension to both the threaded rod and the shaft. The amount of tension applied by the wing nut varies with changes in temperature. To compensate for variations in wing nut tension, at least one spring is provided around the shaft within the hole of the base protrusion. The spring, or springs, is compressed by the tension applied by the wing nut. When compressed, the spring, or springs, also applies tension to the shaft. The tension applied by the spring, or springs, compensates for any reduction in wing nut tension caused by a change in temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention, reference is made to the following description of an exemplary embodiment thereof, considered in conjunction with the accompanying drawings, in which:
FIG. 1 is an exploded perspective view of a container having a flanged access port that is sealed with a cap, wherein the cap is held in place with an exemplary embodiment of a clamping device;
FIG. 2 is a fragmented, exploded view of the rocking bolt assembly used in the clamping device shown in FIG. 1;
FIG. 3 is a selectively cross-sectioned view of the rocking bolt assembly shown in FIG. 1, illustrated in an open condition; and
FIG. 4 is a selectively cross-sectioned view of the rocking bolt assembly shown in FIG. 1, illustrated in a closed condition.
DETAILED DESCRIPTION OF THE INVENTION
Although the present invention clamping device can be used to connect any two objects have the same type of flanged connection, such as two pipes, the present invention is especially well suited for connecting a cap to a container. However, the present invention clamp can be applied to any application of flanged connectors that requires a clamp.
Referring to FIG. 1, there is shown a typical prior art container 10 with a flanged connection 12 . The container 10 is shown with a cap 14 that is used to selectively close the opening defined by the flanged connection 12 . The flanged connection 12 and the cap 14 both have corresponding sized surfaces that align when joined. An O-ring 16 is disposed between the flanged connection 12 and the cap 14 . The O-ring creates a seal between the flanged connection 12 and the cap 14 when it is compressed.
The present invention is a clamping device 20 that extends around the flanged connection 12 and the cap 14 , thereby biasing these two structures together and compressing the O-ring 16 .
From FIG. 1, it can be seen that the clamping device 20 contains at least two arcuate segments 22 , 24 . The arcuate segments 22 , 24 are joined together, thereby forming a structure that can be configured into a generally annular shape. The first arcuate segment 22 terminates with a base protrusion 26 that radially extends away from the center of curvature for the arcuate segment 22 . However, a unique rocking bolt assembly 30 is contained within the base protrusion 26 . The purpose of the rocking bolt assembly 30 is to retain the clamping device in a closed condition and apply a steady clamping force to the arcuate segments 22 , 24 of the clamping device 20 , across a wide range of environmental conditions.
Referring to FIG. 2, it can be seen that the base protrusion 26 of the clamping device 20 defines a hole 34 in which the rocking bolt assembly 30 lay. The hole 34 is not uniform, but rather contains three different sections. Each of the sections has a different diameter. The first section 36 has the smallest diameter. The first section 36 is intersected by a slot 37 that extends from the first section 36 of the hole 34 to the side of the base protrusion 26 . The second section 38 of the hole 34 has a diameter larger than that of the first section 36 and is located next to the first section 36 . This causes a first ridge 39 at the interface between the first section 36 and the second section 38 . The third section 40 has a diameter larger than that of the second section 38 and is located next to the second section 38 . This causes a second ridge 41 at the interface between the second section 38 and the third section 40 .
The elements of the rocking bolt assembly 30 that extend through the hole 34 in the base protrusion 26 , are as follows. A threaded rod 42 is provided. The threaded rod 42 has an eyelet at one end. The threaded rod 42 has a diameter small enough to pass through both the first section 36 of the hole 34 and the slot 37 on the side of the base protrusion 26 . The threaded rod 42 is engaged by a wing nut 44 that is used to tighten the rocking bolt assembly 30 .
The eyelet at the end of the threaded rod 42 is connected to the end of a smooth shaft 46 with a pivot 47 . As a result, the threaded rod 42 can be moved about the pivot 47 relative the smooth shaft 46 . The end of the smooth shaft 46 , opposite the threaded rod 42 , terminates with an enlarged head 48 . The enlarged head 48 may have a cammed inner surface 49 , as will later be explained.
At least one disc spring 50 is placed around the smooth shaft 46 . A disc spring 50 is a spring where the center of the spring lay in a different plane from the periphery of the spring. Although a coil spring can be used, the use of disc springs are preferred. This is because disc springs generally have a higher spring constant per unit of space than do coil springs. Furthermore, due to their compact structure, disc springs are less sensitive to temperature changes than are coil springs.
The disc springs 50 lie around the smooth shaft 46 in the second section 38 of the hole 34 . The combined thickness of the disc springs 50 is larger than the width of the second section 38 , when the disc springs are uncompressed. As a result, the disc springs 50 must be slightly compressed in order to be contained completely within the second section 38 of the hole 34 . The disc springs 50 are confined within the second section 38 of the hole by the first transition ridge 39 and a cam housing 52 . The first transition ridge 39 between the first section 36 and the second section 38 of the hole 34 abuts against the first of the disc springs 50 and prevents the disc springs 50 from advancing into the first section 36 of the hole 34 . On the opposite side of the discs springs 50 , a cam housing 52 is placed around the smooth shaft 46 . The cam housing 52 has a diameter that fits into the third section 40 of the hole 34 but is too large to fit into the second section 38 of the hole 34 . As such, the cam housing 52 cannot be advanced into the hole 34 beyond the second transition ridge 41 between the second section 38 of the hole 34 and the third section 40 of the hole 34 .
The cam housing 52 has an internal cammed surface 54 that faces away from the disc springs 50 . The internal cammed surface 54 of the cam housing 52 engages the cammed surface 49 of the enlarged head 48 at the end of the smooth shaft 46 .
When the wing nut 44 is tightened, the wing nut 44 applies a tension force to the threaded rod 42 . The threaded rod 42 transfers that tension force to the smooth shaft 46 . The tension force biases the enlarged head 48 of the smooth shaft 46 toward the hole 34 in the base protrusion 26 of the clamp assembly. As the enlarged head 48 of smooth shaft 46 advances toward the hole 34 , the cammed surface 49 on the enlarged head 48 meshes with the cammed surface 54 within the cam housing 52 . The tension force in the smooth shaft 46 is then transferred as a compression force to the cam housing 52 . The cam housing 52 itself is then biased into the third section 40 of the hole 34 by the compression force. As the cam housing 52 is biased into the third section 40 of the hole 34 , the cam housing 52 pushes the disc springs 50 into the second section 38 of the hole 34 . If the compression force surpasses the spring coefficient of the disc springs 50 , the disc springs 50 compress until the cam housing 52 abuts against the second transition ridge 41 .
If the wing nut 44 is over rotated., the tension force applied to the smooth shaft 46 may surpass a predetermined maximum threshold value. The cammed surface 49 on the enlarged head 48 and the cammed surface 54 in the cam housing 52 are designed to engage each other until the maximum threshold value is reached. If a tension force is experienced that surpasses the maximum threshold value, the cammed surface 49 on the enlarged head 48 and the cammed surface 54 in the cam housing 52 slip passed each other. As such, the smooth shaft 46 is free to spin with the threaded rod 42 and the wing nut 44 , thereby making further tightening impossible.
Referring to FIG. 3, it can be seen that to use the clamp assembly, both base protrusions 26 , 27 of the clamp assembly are aligned. The wing nut 44 is then rotated so that the threaded rod 42 and the smooth shaft 46 linearly align. Once aligned, the wing nut 44 is tightened so that the wing nut 44 biases the two base protrusions 26 , 27 of the clamp assembly toward each other.
Referring now to FIG. 4, it can be seen that when the wing nut 44 is fully tightened, the disc springs 50 become compressed. There are now two elements that are applying tension to the threaded rod 42 and the smooth shaft 46 . The first element is the wing nut 44 as it abuts against the base protrusion 27 of the clamp assembly. The second element is the disc springs 50 . The disc springs 50 apply tension to the smooth shaft 46 throughout their range of compression. Accordingly, should the wing nut 44 become loose, the tension in the smooth shaft 46 would remain constant because the disc springs 50 would partially decompress to compensate for the loosening wing nut 44 . If the disc springs 50 were compressed a total of ¼ inch, then the wing nut 44 can be retracted ¼ inch without effecting the tension in the smooth shaft 46 and thus the clamping strength of the assembly.
Furthermore, should the force applied to the clamp by the wing nut 44 become greater due to changes in temperature, the excess tension force can be absorbed by further compressing the disc springs 50 and the tension applied to the clamp assembly remains relatively constant.
The clamping device therefore provides a means to maintain a relatively constant clamping pressure on a flanged opening throughout a wide range of changing temperatures and internal vessel pressures. The result is a more reliable and versatile clamp that creates a more reliable and versatile seal.
In the described embodiments, a cam housing was used to prevent the wing nut from being over tightened. This feature is optional. All components in the clamp assembly are preferably made of stainless steel. Accordingly, it is unlikely that enough force can be applied by hand to damage the clamp assembly. The described cam housing can simply be replaced with a flat washer if desired. Similarly, the cammed surface on the enlarged head of the smooth shaft can also be eliminated.
It will be understood that the various figures described above illustrate only one preferred embodiment of the present invention. A person skilled in the art can therefore make numerous alterations and modifications to the shown embodiment utilizing functionally equivalent components to those shown and described. For example, there are numerous types of spring elements and spring configurations that can be substituted for the disc springs described. All such modifications are intended to be included within the scope of the present invention as defined by the appended claims. | A clamp device that is used to maintain a consistent clamping pressure on a flanged connection despite changes in temperature and changes in internal pressure behind the flanged connection. The clamp device contains a rocking bolt assembly that is manually tightened with a wing nut. Should the wing nut loosen, the rocking bolt assembly contains internal springs that compensate for the loosened wing nut and maintain a relatively consistent tension in the rocking bolt assembly within a predefined range of conditions. | 5 |
PRIORITY INFORMATION
[0001] This application is a divisional application claiming priority from U.S. patent application Ser. No. 12/029,228, filed on Feb. 11, 2008.
FIELD OF THE INVENTION
[0002] The field of this invention is downhole debris catching tools and more specifically those that reverse circulate into a mill to capture the cuttings as they come up through the tool.
BACKGROUND OF THE INVENTION
[0003] Milling Operations downhole generate cuttings that a captured in tools associated with a mill frequently referred to in the industry as junk catchers. There are many configurations for such tools. Some have external seals that direct cuttings coming up from a mill around the outside of the tool back into the tool so that the circulating fluid can exit while the debris is captured in the tool body. Examples of this design are U.S. Pat. Nos. 6,176,311 and 6,607,031. Another design involves establishing a reverse circulation with jets that discharge outside a tool body toward a mill below and act as eductors to draw fluids through the mill and into a screened section central passage. Once the debris laden fluid exits the central passage the velocity slows and debris drops into an annular passage and the fluid keeps going toward the top of the tool. On the way out the top the remaining debris is left on a screen and can drop into the same annular space that caught the larger debris further down the tool as the now screened fluid is drawn by the jets at the top of the tool to go right back down around the outside of the tool toward the mill so that the cycle can repeat.
[0004] FIG. 1 illustrates the basics of this known design. A mill 10 generates cuttings that are removed with reverse circulation that goes up passage 12 and exits at 14 into a wide spot 16 in the tool body 18 . The heavier debris falls into annular space 20 around the passage 12 while the fluid stream with some smaller debris continues up the tool body 18 until it reaches a screen 22 . The debris remaining is caught outside the screen 22 and eventually falls to annular space 20 . The clean fluid is drawn by the jets 24 fed by fluid pumped from the surface through a string (not shown). Exhaust from the jets 24 combined with fluid drawn by those jets now goes back down around the tool body 18 toward mill 10 and the rest goes up to the surface outside the tubular string that runs from the surface (not shown).
[0005] FIG. 2 shows a detail of the junk catcher of FIG. 1 . What is depicted is the lower end just above the mill 10 . A threaded connection 26 holds the bottom sub 28 to the tool body 18 . Debris 30 typically falls down in annular space 20 and wedges tube 32 that defines the passage 12 and prevents the ability to relatively rotate the bottom sub 28 with respect to body 18 to get the threaded connection 26 to let loose. That threaded connection 26 has to get undone so that the debris 30 can get flushed out of the tool when it is brought to the surface. Note that the tube 32 is attached to the bottom sub 28 and in the past efforts to get the threaded connection undone have sheared the tube 32 or have otherwise caused it to crack or fail when debris 30 got compacted in annular space 20 .
[0006] Another issue was that tube 32 was prefabricated to a predetermined length which limited the volume of the annular space 20 . Yet another issue occurred when the surface pumps were shut off and debris on the screen 22 can fall through the hat 34 through the side openings 36 under it.
[0007] Turning now to FIG. 7 , a detailed view of the mill 10 from FIG. 1 is shown with a central passage 38 leading to circulation outlets 40 four of which can be seen in the associated bottom view. Passages 40 are far smaller than passage 38 that feeds them. This layout worked well for normal downhole milling with circulation going down passage 38 to outlets 40 when a tool or other wellbore obstruction was milled out in a traditional way. However, in conjunction with the debris catcher shown in FIG. 1 there was a problem since the circulation patterns are reversed for the debris catcher in FIG. 1 and cuttings are reverse circulated into the body of mill 10 which leads to plugging of the passages 40 . The mills of FIG. 7 had blades 42 featuring inserts 44 and textured carbide faces in between to assist in the milling operation.
[0008] The present invention provides for greater capacity variation for the tool illustrated in FIG. 1 leading to a modular design with passages that feature dog legs to promote dropping of debris into annular catch volumes located below dog legs. An alternative uses a modular approach with aligned modules that have flapper valves that can fall shut when circulation stops to prevent debris from falling back to the mill. The mill configuration has been changed to accommodate reverse circulation without the plugging issues of prior designs illustrated in FIG. 7 . These and other aspects of the present invention will be more apparent to those skilled in the art from a review of the description of the preferred embodiments and associated drawings that appear below while understanding that the full scope of the invention is given by the claims.
SUMMARY OF THE INVENTION
[0009] A debris catching device for downhole milling features modular debris receptacles that are held in the housing in a manner that facilitates stacking and a generally undulating flow path to facilitate dropping of the debris into the receptacles as the remaining fluid travels up the tool for ultimate screening before the fluid exits the tool to flow up to the surface or in a reverse circulation pattern back to the mill below the debris catcher. The modules can also be aligned with flapper valves at the top of each module to prevent debris in the tool from falling to the mill if circulation is turned off. The mill is configured to have an off-center return path preferably as large as the passage through the mill body to aid circulation and cutting performance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a section view of an existing design of a debris catcher that uses reverse circulation flow patterns;
[0011] FIG. 2 is a detailed view of the lower end of FIG. 1 showing the way the single debris catching structure and the passage along side of it and the manner of its fixation to the housing;
[0012] FIG. 3 is one version of a modular design of internals for debris catching showing an undulating flow path up the tool body;
[0013] FIG. 4 is a detailed view of two modules shown in FIG. 3 ;
[0014] FIG. 5 shows an aligned modular design featuring flapper type valves at the top of each module;
[0015] FIG. 6 is a further detailed view of the module of FIG. 5 showing how it is attached to the tool body;
[0016] FIG. 7 is a section and end view of a mill used in conjunction with a debris catching device such as is shown in FIGS. 1 and 5 ;
[0017] FIG. 8 is a section and an end view of a mill that can be used in conjunction with a debris catcher, for example, as shown in FIG. 3 or 5 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] FIG. 5 shows a mill 50 with one embodiment of the debris catching tool 52 mounted above it. In this embodiment there are modules 54 and 56 shown in housing 55 although additional modules can be used. The modules 54 and 56 are shown in larger scale in FIG. 4 and without the housing 55 so that the flow pattern can be more easily seen. Debris laden fluid from the mill 50 enters passage 58 in module 54 . Sitting beside passage 58 is passage 60 with both passages open at the upper end 62 of module 54 . Upper end 62 is beveled and lower end 64 of module 56 is also beveled in a conforming way leaving a gap 66 between ends 62 and 64 . Passage 58 continues up the tool into passage 66 of module 56 . Passage 60 in module 54 has a closed bottom 68 . When debris laden fluid exits passage 58 at the top 62 the velocity slows and the fluid stream has to negotiate a double bend to continue into passage 66 . The combination of a slowing velocity and making the double bend to a position over the passage 60 allows debris to fall into passage 60 where they are collected until the tool 52 is removed to the surface.
[0019] Meanwhile flow continues up the tool 52 through passage 66 until the fluid stream reaches the upper end 70 where there is another velocity reduction so that any even lighter debris still being taken along can have another chance to drop out into passage 72 that has a closed bottom 74 all of which are part of module 56 . Note that the upper end 70 is squared off rather than beveled because in this example it is the top module. The idea is that between modules there is a cross-over effect to allow the combination of reduction of velocity by entering a larger cross-section area of the tool to work in conjunction with gravity to let the debris fall down into a receptacle in position right below the flowing stream. After the flowing stream passes the upper end 70 it enters an enlarged cross-section zone 72 , shown in FIG. 3 . It then goes through a screen 74 and is then drawn by eductors 76 whose exhaust goes two ways; uphole in an annular space represented by arrow 78 or downhole around the annular space outside the tool body 52 toward the bit 50 . String 80 feeds fluid to the eductor jets 76 as the process of milling continues and ultimately the tool 52 is removed from the well and taken apart at joints that are disposed between the modules such as 54 and 56 .
[0020] The preferred fixation technique is shown in FIG. 6 although it is in the context of a different modular design. FIGS. 5 and 6 go together as an alternative modular design. The lowest module 82 is shown in both FIGS. and is typical of the preferred attachment system for each module. As shown in FIG. 6 the tool housing 84 surrounds the tube 86 . In this embodiment there is but a single passage 88 in tube 86 with the debris caught in annular space 90 after the fluid stream pushes open the flapper valve 92 located above a screen section 94 . Centralizers 96 can be mounted to tube 86 to keep the annular space 90 around the tube 86 reasonably uniform in dimension over the length of tube 86 . Tube 86 terminates at 96 and just above that location one or more set screws or fasteners 98 are threaded through the housing 84 . A plugged cleanout hole 100 is also provided. At the surface after milling, the housing 84 is broken out at its top 102 and near its bottom at thread 104 . The plugged cleanout 100 is opened to flush debris out as much as possible to end 102 . After that is done the set screws or fasteners 98 are undone and the tube 86 should come right out. Since the tube 86 from its lower end 96 to the flapper 92 is only held in housing 84 with the set screws 98 its release is far simpler than the prior design shown in FIG. 2 where the tube was integral to a sub 28 that was threaded at 26 and the presence of compacted debris around the tube 20 either damaged the tube or the threaded connection 26 as efforts were made to undo it.
[0021] The modular design of FIGS. 5 and 6 with preferably centrally mounted modules with a screen 94 and a flapper 92 is designed to let flow go backwards bypassing the closed flapper 92 and going through the screen 94 , if circulation is cut off so that debris can still settle in the annular space 90 around each module and the liquid can go through the screen 94 because the flappers 92 are all closed and run out the mill 50 as the tool 52 is pulled out of the hole. While the tubes 86 are shown in their preferably centralized orientation, they can be offset from each other as well.
[0022] Turning now to the design of the mill and FIGS. 7 and 8 , as mentioned before the problem with the FIG. 7 design was that the outlets 40 would clog with debris which could overheat or simply just stall the mill in a tangle of cuttings. Another issue with the former design was that the blades 42 come short of the center 104 leaving just an array of ground carbide particles in that region. When milling out a packer, for example, the effect was uneven milling. Mills that simply used a central bore to accept reverse circulation flow when milling suffered from having no milling going on near their centers so as to leave a core of un-milled tool as the cutting progressed. The mill of the present invention in FIG. 8 has a main bore 106 preferably centrally located with a bend 108 so that the entrance for cuttings 110 is near the circumference 112 . A network of passages 114 directs the cuttings from the action of the carbide particle arrays 116 to the entrance 110 . The passages 114 also direct reverse circulating fluid coming down outside the tool into the entrance 110 . There are two main advantages of this design. One is that the entrance 110 is close to or even larger than the bore 106 to reduce if not eliminate the problem of balling up of cuttings in the FIG. 7 design from small inlets 40 as compared to the main passage above them 38 . Another advantage is that the offset inlet 110 allows for particle arrays 116 otherwise on the periphery at circumference 112 to take up the slack of a missing portion of cutting structure at or near the periphery to still get effective milling at the periphery as opposed to locating the inlet in the center which would contribute to a no milling zone or a coring effect of milling the exterior of a downhole tool without the center.
[0023] Those skilled in the art will appreciate that the improvements to the debris catching tool using the modular designs makes them more likely to come apart at the surface for cleaning when laden with cuttings that could be compacted. A plugged cleanout 100 allows an initial attempt to flush the cuttings clear of a surrounding modular housing before undoing the set screws 98 to allow removal with a pull out force at the opposite end such as near the centralizers 96 . The modular design can incorporate a flow path with a debris receptacle in each module and a sinuous path for flow coupled with sudden enlargements of the flow area where the bends are so that the reduced velocity will act with gravity to allow the debris to drop straight down to an aligned debris receptacle in a given module below. Alternatively, using modules as shown in FIG. 6 the flow can come straight up through the modules and due to gaps between the modules where the velocity slows debris can still fall away and be pushed to the periphery when it will fall down into the annular collection area in part made possible by centralizers 96 around the tube 86 . When there is no circulation, the flappers 92 close and drainage to the mill 50 can occur through the screens 94 in each module. In that way a wet string is not pulled and debris is not permitted to fall back into the mill 50 when circulation stops. The mill reduces clogging with debris with the inlet 110 as large as or larger than the bore 106 and the offset from center location of it allows adjacent cutting structure near the periphery to compensate for the zone of missing cutting structure where the inlet 110 is located. This reduces the coring effect as compared to prior designs with central inlets.
[0024] The use of a modular design allows the ability to match the expected level of cuttings with the storage capacity to hold them until the milling is done. The mounting technique facilitates removal when the tool is laden with cuttings with minimal risk of damage to the modules and rapid reassembly is facilitated.
[0025] The above description is illustrative of the preferred embodiment and many modifications may be made by those skilled in the art without departing from the invention whose scope is to be determined from the literal and equivalent scope of the claims below. | A debris catching device for downhole milling features modular debris receptacles that are held in the housing in a manner that facilitates stacking and a generally undulating flow path to facilitate dropping of the debris into the receptacles as the remaining fluid travels up the tool for ultimate screening before the fluid exits the tool to flow up to the surface or in a reverse circulation pattern back to the mill below the debris catcher. The modules can also be aligned with flapper valves at the top of each module to prevent debris in the tool from falling to the mill if circulation is turned off. The mill is configured to have an off-center return path preferably as large as the passage through the mill body to aid circulation and cutting performance. | 4 |
This is a Section 371 national phase application of PCT/EP 01/06157, and claims priority of DE 100 28 908.8 filed Jun. 10, 2000.
REFERENCE TO RELATED APPLICATIONS
This disclosure claims the benefit of the filing date of International Application No. PCT/EP02/07403, having an international filing date of Jul. 4, 2002, which designated the United States of America, and this disclosure is the United States national stage of that international application. This disclosure further claims priority to Germany patent application 101 33 104.5, filed Jul. 12, 2001.
BACKGROUND OF THE INVENTION
In cross-flow filtration, a feed liquor to be filtered flows through an overflow channel, whereby the feed is directed against the surface of the filter element tangentially. The filter splits the feed into a concentrate (retentate) and a filtrate (permeate). The filter element is generally a polymeric microporous membrane with pores sized so as to be capable of ultrafiltration or microfiltration. Average pore sizes for an ultrafiltration membrane, typically characterized by an exclusion threshold, make possible the retention of macromolecules ranging from 500 to 1,000,000 Daltons, while those for a microfiltration membrane are in the range of 0.01 to 10 μm. The subjects of exclusion thresholds and average pore sizes and their determination are discussed in Scheuermnann, Handbook of Industrial Solids/Liquids Filtration (1990) at pages 250-262.
The retentate is diverted onto the overflow surface of the filter membrane and may be recycled to flow over the same surface again, thus providing for repeated permeate passes. The permeate permeates the filter membrane in a direction substantially perpendicular thereto and is collected below the filter element in a permeate channel and is conducted away from the filtration device. The target substance can be in the permeate and/or in the retentate. Cross-flow filtration devices may have one or more overflow channels. See DE A1 196 36 006 and DE PS 34 41 249. Devices with a multiplicity of overflow channels are mainly in the form of filter cassettes, as disclosed in DE PS 34 41 249. The cassettes consist of a plurality of adjacent filter cells, which, as a rule, are constructed from alternatingly positioned, flat sections of a passage forming an overflow channel for the feed, a first membrane array, a permeate holder for the formation of a filtrate channel, and a second membrane array. Each overflow opening is in fluid communication with an inlet for the feed and with an outlet for the retentate. Each permeate channel is in fluid communication with a permeate outlet.
As retentate is captured it begins to build up and tends to obstruct the pores of the filter element, but by virtue of its tangential flow over the filter's surface, is flushed from the surface, so that the filter's pores are freed for permeation of the feed. In spite of this, for various reasons a layer builds up on the surface of the filter element. Because of this, as a rule, the filtration capacity as well as the operational life of cross-flow filtration devices are diminished.
It is therefore a primary goal of the invention to provide a cross-flow filtration device that avoids the foregoing problem and that exhibits an improved filtration capacity and a substantial operational life.
BRIEF SUMMARY OF THE INVENTION
In accord with the invention, the permeate channels of a cross-flow filtration device are provided with barriers. These barriers are placed at a distance away from the permeate outlet so as to impede or block the flow of permeate, resulting in the maintenance of a more uniform transmembrane pressure. The inventive cross-flow filtration device achieves a degree of permeate flow that is much greater than that delivered by state-of-the-art devices with a minimum of energy input, that is to say, with relatively small feed velocities over the surface of the filter element.
Fluids which may be filtered with the inventive cross-flow filtration devices include emulsions, suspensions, beer, wine, juice, water, milk, whey, and brewers wort. The devices can be applied to the filtration of process and waste waters, to solutions in the fields of pharmaceuticals, medicine, cosmetics, chemistry, biotechnology, gene technology, environmental control and in the laboratory. They can be employed for the recovery of valuable materials and for separation of substances such as the separation of macromolecules and bio-molecules. They can also be used for depyrogenation and for sterilization of solutions, for the separation of damaging materials from solutions, for the separation of microorganisms such as bacteria, yeasts and viruses and for the separation of cell components. Other applications include the desalting of protein solutions and other biological media.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a schematic longitudinal cross-sectional view of an exemplary embodiment of the invention.
FIG. 2 is a schematic longitudinal cross-sectional view of another exemplary embodiment of the invention.
FIG. 3 is a top view of a spacer element having two barriers.
FIG. 4 is a schematic longitudinal cross-sectional view of yet another exemplary embodiment of the invention with a plurality of overflow and permeate channels.
FIG. 5 is a graph showing the course of a filtration with the inventive device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, wherein like numerals generally refer to the same elements, there is shown in FIGS. 1-2 and 4 the inventive cross-flow filter with permeate channel 1 and overflow channel 2 , the latter being in fluid communication with feed inlet 3 and retentate outlet 4 . Permeate channel 1 and overflow channel 2 are separated from one another by a flexible filter element 5 , and permeate channel 1 is in fluid communication with permeate outlet 6 . Although feed inlet 3 and retentate outlet 4 are placed as far as possible from each other, retentate outlet 4 and permeate outlet 6 are proximal to one another. Barriers 7 are located in permeate channels 1 distal to permeate outlets 6 , which spacing obstructs permeate flow to the permeate outlets. Barriers 7 may be components of spacers 8 , which for example, may be in the form of webbing (FIG. 1 ), nonwoven fabric ( FIG. 2 ) or woven fabric (FIG. 3 ).
In FIG. 1 the cross-flow filter is depicted during filtration, wherein the filter element 5 has yielded to form a flowover passage 9 for the permeate, allowing flow from the first section 10 of the permeate channel 1 into the second section 11 of the same channel. FIG. 3 is a plan view showing detail of spacer 8 in the form of a woven fabric with two barriers 7 ; such spacers 8 are shown integrated into a filter cassette in FIG. 4 . Sealant 12 surrounds feed inlets 3 and retentate outlets 4 , thereby preventing the influx of feed liquor and retentate into permeate channel 1 through spacer 8 . Permeate outlets 6 need no sealant.
The filter cassette shown in FIG. 4 is a so-called wide open module, characterized by spacer supports 13 on both ends of spacers 8 .
Transmembrane pressure (TMP) in the cross-flow filter is defined by the mathematical expression I as follows:
TMP= [( P E +P A )/2 ]−P F (I)
where P E =pressure at the inlet of the overflow channel, P A =pressure at the outlet of the overflow channel, and P F =pressure at the outlet of the permeate channel.
If a cross-flow filtration device wherein the outlet of the permeate channel is in proximity to the outlet of the overflow channel is operated, for example, at P E =3 bar, P A =1 bar, and P F =1 bar, then the nominal transmembrane pressure is 1 bar. However, in the vicinity of the inlet, TMP would typically be closer to 3 bar, allowing substantially greater quantity of permeate to pass through the filter element, thereby causing a greater quantity of materials from the feed liquor to collect on the surface of the filter element in the inlet zone, leading to rapid diminishment of the filtering capacity of the filter element in the inlet zone. Assuming a linear relationship, the drop or increase in pressure between the inlets and outlets of the overflow channels or permeate channels, upon placement of a barrier 7 at the mid-point of the permeate channel ( FIG. 1 ) would result in TMP=0.5 at the above-mentioned operating pressures. Furthermore, this TMP exists at the outlet of the filtering device, in its mid-section, and also at the barrier 7 . From the feed inlet 3 up to the barrier 7 (section 10 in FIG. 1 ) TMP may be calculated from equation I as 0.5 bar, where P E =3 bar, P A z(at the top of the barrier) =2 bar and P F(at the barrier) =2 bar. From the top of the barrier 7 to the outlet 6 (Section 11 in FIG. 1 ), TMP is calculated from equation I as 0.5 bar, where P E(at the top of the barrier) =2 bar, P A =1 bar and P F =1 bar.
The assumption is that where filtrate flow in a section upstream of barrier 7 (section 10 in FIG. 1 ) is restricted or obstructed, then the permeate pressure in that section will be less than the feed pressure in the overflow channel at the top of the barrier. Should the permeate pressure in section 10 exceed this assumed lower pressure, then the flexible filter will yield to the pressure and be pushed away from spacer 8 to either create or enlarge a flowover passage 9 for the permeate, whereby it is allowed to flow into the section downstream the barrier (section 11 of FIG. 1 ). If the pressure in section 10 of the permeate channel returns to the pressure in the overflow channel at the top of barrier 7 , then the flexible filter relaxes, thereby closing or diminishing flowover passage 9 and preventing or diminishing further passage of the permeate over barrier 7 . Thus, barriers 7 in conjunction with flexible filters 5 in the permeate channels act much like self-regulating pressure valves.
The permeate channel of the inventive filtration device should be provided with at least one barrier. However, more than one barrier may be provided, spaced evenly or unevenly. Advantageously, a barrier is placed transverse to the direction of permeate flow. The barriers are substantially impermeable to the permeate liquid, permitting substantially no convective material transport therethrough. Barriers can and preferably do extend over the entire width of the permeate channel, as shown in FIG. 3 , but it may also have a smaller width and/or height than the permeate channel. In the case of multiple barriers, these may be sized the same or differently, but equal longitudinal dimensions are preferred to achieve uniform pressure relationships. Experience with the inventive filters has shown that when the barriers extend over the entire width of the permeate channel(s), increased permeate flow can be achieved with barriers having a height of as little as about one-half that of the permeate channel. At a height of about two-thirds that of the permeate channel, increased flux can be observed immediately.
The most effective barrier is one which extends over the entire height and width of the permeate channel, whereby the barrier totally blocks the permeate channel under non-pressure conditions. In the case of a barrier that is about one-third the height of the permeate channel and is the same width as the permeate channel, practically no effect can be observed. On this account it is preferred that the barriers extend over the entire cross-section of the permeate channel.
Depending upon the size of the cross-flow filtration device, barriers are preferably up to about 10 mm in thickness. When the filter element is reinforced by packing the permeate channel with uniformly distributed, permeable spacing material, it is advantageous to incorporate the barriers as components of such spacing material. Advantageously the spacing material can be a textile (a woven fabric, a webbed material, a non-woven fabric or a lattice) which contains the barrier; a woven fabric is preferred. For the filter element, polymeric membranes are preferred because these have the flexibility required to deform under pressure so as to form the flowover passage. In a preferred embodiment, the filter device is provided with a multiplicity of overflow and permeate channels in alternating sequence. Particularly favored are devices constructed in the form of filter cassettes. The barrier can be constructed of either a rigid or a flexible material, but are preferably composed of elastic polymers such as durable silicone.
In the Examples which follow cross-flow filtration took place in a Sartocon® 2Plus filter cassette of substantially the same design shown in FIG. 4 (from Sartorius AG of Goettingen, Germany). The cassette was provided with 32 hydrophilic microporous membranes of crosslinked cellulose hydrate with an average pore size of 0.6 μm (Hydrosart® from Sartorius AG), 16 permeate channels packed with a woven fabric 450 μm thick, and 17 overflow channels for feed with a woven fabric 610 μm thick employed as a spacer therein. The woven fabrics in the overflow channels were covered in the edge areas with spacer supports 50 μm thick. The membrane surface area available for filtration was 0.6 m 2 . A 20% yeast solution was filtered at 25° C. The pressure P E at the inlet of the overflow channels was 4 bar, while the pressures at the outlets for of the overflow channels P A and at the outlets of the permeate channels P F were both 0 bar.
EXAMPLE 1
The above-described filter cassette was provided with spacers placed midway in the permeate channels and aligned transversely to the flow direction of the feed. Each permeate channel 1 was equipped with barrier 7 of durable elastic silicone 10 mm thick and having a height equal to the thickness of the spacer fabric (which was also the height of the permeate channel 1 ). Five minutes after the start of the filtration, the permeate flow was measured at 400 L/h•m 2 ; after 90 minutes it was about 170 L/h•m 2 .
Comparative Example
The filter cassette of Example 1 was used for the same filtration conducted in Example 1, but not provided with any barriers. The following permeate flows were achieved: after five minutes about 1100 L/h•m 2 ; after 90 minutes about 50 L/h•m 2 .
FIG. 5 is a graph of the filtrate flow in L/h•m 2 versus time of filtration in minutes from Example 1 and the Comparative Example. The upper curve is from the data of Example 1.
EXAMPLE 2
Filter cassettes of substantially the same design as that of Example 1 were used to conduct filtration on a 10% yeast solution with the following changes: different sized barriers were used; the cassettes were provided with 14 membranes, 7 permeate channels and 8 overflow channels; the surface area available for filtration was 0.3 m 2 ; and the membrane had an average pore size of 0.45 μm. To determine what influence the height of the barrier (which had the same width as the permeate channel) had on permeate flow, three cassettes A, B and C were provided with variances in the barrier element as follows:
in device A, one barrier was placed in each permeate channel at the mid-point, the height of which was two-thirds the height of the permeate channel; in device B, one barrier was placed in each permeate channel at the mid-point, the height of which was one-third the height of the permeate channel; and in device C, no barriers were provided.
Pressure values were P E =3 bar and P A =P F =0 bar. After about 30 minutes of filtration, a substantially constant permeate flow was established and the permeate and retentate flows were measured. The results are given in Table 1.
TABLE 1
Flow (L/h · m 2)
Device A
Device B
Device C
Permeate
120
86
88
Retentate
1760
1800
2200
From the data in Table 1, the much greater permeate flow in Device A is apparent, while the permeate flows for Devices B and C were substantially the same.
The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow. | Cross-flow filters having improved uniformity in transmembrane pressures and consequent much greater flux are provided by the installation of barriers in permeate channels. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is based on Japanese Patent Applications No. 2004-311332 filed on Oct. 26, 2004, and No. 2005-259700 filed on Sep. 7, 2005, the disclosures of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a circuit board and a semiconductor device having a circuit board.
BACKGROUND OF THE INVENTION
Conventionally, regarding ECU for an automotive vehicle, when a passenger or a driver operates a switch, electrostatic charge may penetrate into the ECU through a wiring harness, so that an IC in the ECU is damaged. Thus, to protect the ECU from the static charge, an electric part such as a resistor is formed on an input side of the ECU. The electric part for the protection of the ECU prevents not only the static charge but also external noise from penetrating into the ECU.
Further, recently, the number of electric parts in the ECU in the vehicle increases, and an accommodation space for the ECU becomes smaller. Thus, it is required to minimize the ECU and to increase the number of electric parts in the ECU.
Furthermore, to improve lifetime of a solder, an electrode is formed on a long side of the electric part in the ECU, instead of a short side of the part. In this case, a distance between electrodes becomes narrower, compared with a case where the electrode is formed on the short side of the part.
Thus, the electric part for the protection of static charge is minimized, and the distance between the electrodes of the parts becomes narrower so that a distance between lands on a circuit board becomes narrower, the lands corresponding to the electrodes. Therefore, conventionally, the electric part such as the resistor can prevent the static charge from penetrating into the IC of the ECU, i.e., the static charge penetrating into the IC is reduced. However, in the above device, since the distance between the lands is short, the static charge transmits between the lands through the protection part so that the static charge is not reduced in the protection part. Thus, the static charge directly penetrates into the IC so that the IC is damaged.
To protect the IC from the above direct transmission of the static charge, Japanese laid-Open Patent Publication No. S62-35480 discloses a circuit board. The circuit board includes the first wiring and the second wiring. The first wiring includes a resistor for limiting current, and formed on a signal input terminal side of a semiconductor circuit package. The second wiring works as a ground, and includes two parts, one of which protrudes and extends in parallel to the first wiring, the other one of which is connected to the semiconductor circuit package. The circuit board includes a protrusion facing the first and the second wirings so that a spark gap is provided. The spark gap is covered with a tape.
In general, a wiring is coated with an insulation film. Accordingly, in the device having the spark gap between the first and the second wirings, the static charge is not absorbed effectively, since the wiring is covered with the insulation film. Thus, the static charge may damage the IC.
SUMMARY OF THE INVENTION
In view of the above-described problem, it is an object of the present invention to provide a circuit board and an electric device having a circuit board.
A circuit board includes: an input terminal for inputting a signal from an external circuit; a first land and a second land; and an electrostatic-charge absorbing conductor for absorbing an electrostatic charge. The first land is electrically connected to the input terminal. The second land is separated from the first land by a predetermined distance therebetween. A distance between the electrostatic-charge absorbing conductor and the first land is shorter than a distance between the first land and the second land.
In the circuit board, the electrostatic charge penetrated from the input terminal is effectively absorbed into the electrostatic-charge absorbing conductor through the first land so that the electrostatic charge is prevented from negatively affecting on electric parts on the circuit board.
Alternatively, the circuit board may further include a first electric part disposed on the first land. The first electric part is an electrostatic charge reducing element for reducing the electrostatic charge. Alternatively, the first land may include a first electric field concentration portion, at which an electric filed is concentrated, and the electrostatic-charge absorbing conductor is disposed near the first electric field concentration portion of the first land. Alternatively, the electrostatic-charge absorbing conductor may include a second electric field concentration portion, at which an electric filed is concentrated. The second electric field concentration portion of the electrostatic-charge absorbing conductor faces or is disposed near the first electric field concentration portion of the first land.
Alternatively, the electrostatic-charge absorbing conductor may be disposed between the first land and the second land, or disposed under the first electric part.
Alternatively, the circuit board may further include: a substrate having a first plane and a second plane; and an electrode. The first electric part is disposed on the first plane of the substrate. The electrode is disposed on the second plane of the substrate. The electrostatic-charge absorbing conductor is a via conductor in a via hole of the substrate. The via conductor is disposed on the first plane of the substrate, and electrically connected to the electrode on the second plane of the substrate.
Alternatively, the second land may be electrically connected to a ground through a capacitor. The circuit board may further include: a third land electrically connected to the first land and the input terminal; a second electric part disposed on the third land; and a fourth land separated from the third land by a predetermined distance, and connected to the ground. A distance between the third land and the fourth land is shorter than the distance between the first land and the second land.
Further, an electric device includes: a circuit board including an input terminal for inputting a signal from an external circuit; a first land disposed on the circuit board and electrically connected to the input terminal; a second land disposed on the circuit board and separated from the first land by a predetermined distance; a first electric part mounted between the first land and the second land; an input circuit element electrically connected to the second land and disposed on the circuit board; and an electrostatic-charge absorbing conductor disposed on the circuit board for absorbing an electrostatic charge. A distance between the electrostatic-charge absorbing conductor and the first land is shorter than a distance between the first land and the second land.
In the device, the electrostatic charge penetrated from the input terminal is effectively absorbed into the electrostatic-charge absorbing conductor through the first land so that the electrostatic charge is prevented from negatively affecting on electric parts on the circuit board.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings. In the drawings:
FIG. 1 is a plan view showing an electric device according to a first embodiment of the present invention;
FIG. 2 is a cross sectional view showing the device taken along line II-II in FIG. 1 ;
FIG. 3 is a plan view explaining a relationship between a via conductor and a land in the device according to the first embodiment;
FIG. 4A is a graph showing a relationship between size of mounted parts and an electrostatic withstand voltage, and FIG. 4B is a table explaining the relationship between the size of the mounted parts and the electrostatic withstand voltage, according to the first embodiment;
FIG. 5 is a plan view explaining a relationship between a via conductor and a land in an electric device according to a second embodiment of the present invention;
FIG. 6 is a plan view explaining a relationship between a via conductor and a land in an electric device according to a third embodiment of the present invention; and
FIG. 7 is a plan view explaining a relationship between a via conductor and a land in an electric device according to a fourth embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
An electric device 100 according to a first embodiment of the present invention is shown in FIGS. 1 and 2 . FIG. 3 shows a relationship between a via conductor and a land in the device 100 . FIG. 4 shows a relationship between a distance between the lands and erector-static withstand voltage. The device 100 includes a circuit board 10 , which is a multi-layered circuit board composed of multiple sheets made of dielectric material. A conductive pattern is formed on the sheets. The circuit board 10 includes first to sixth wirings 20 - 25 , first to sixth lands 30 - 35 , an inner layer ground pattern 40 , and first to third via conductors V 1 -V 3 . On the circuit board 10 , a connector 50 , an input IC 60 for inputting an electric signal, first and second resistors R 1 , R 2 , and a capacitor C are mounted. Although the circuit board 10 is formed of a binary-layered circuit board, the circuit board 10 may be formed of other multi-layered circuit board such as a ternary-layered circuit board.
The first wiring 20 electrically connects between an input terminal 51 and the third land 32 , the second wiring 21 electrically connects between the third land 32 and the first land 30 , the third wiring 22 electrically connects between the fourth land 33 and the third via conductor V 3 , the fourth wiring 23 electrically connects between the third via conductor V 3 and the sixth land 35 , the fifth wiring 24 electrically connects between the fifth land 34 and the second land 31 , the sixth wiring 25 electrically connects between the second land 31 and the input IC 60 . Each wiring 20 - 25 other than a connection portion for connecting to a terminal or a land is covered with an insulation film.
The first and the second resistors R 1 , R 2 and the capacitor C are mounted on the first to sixth lands 30 - 35 . Each land 30 - 35 is not covered with an insulation film so that the conductor of the land 30 - 35 is exposed outside. This is because the first and the second resistors R 1 , R 2 and the capacitor C are electrically bonded to the land 30 - 35 with a solder. Here, each wiring 20 - 25 is covered with the insulation film.
The inner layer ground pattern 40 is formed on a sheet made of dielectric material and composing the circuit board 10 . The inner layer ground pattern 40 is formed inside of the circuit board 10 . The inner layer ground pattern 40 is connected to the first to third via conductors V 1 -V 3 and a ground terminal 52 through via holes. The first to third via conductors V 1 -V 3 correspond to an electrostatic-charge absorbing conductor.
The connector 50 connects electrically between an external circuit and the device 100 . The connector 50 includes the input terminal 50 and the ground terminal 52 . The input IC 60 includes an AD converter for converting an analog signal to a digital signal so that the input IC 60 processes an input signal.
The first resistor R 1 and the capacitor C provide RC filter for protecting a noise from penetrating into the device 100 . The electrostatic charge penetrating from the input terminal 51 is reduced by the RC filter. The first resistor R 1 corresponds to an electrostatic-charge reducing device. The second resistor R 2 works in a case where the signal is not inputted into the input terminal 51 . Further, the second resistor R 2 is a pull-down resistor for fixing electric potential of a ground state so that the input IC 60 is connected to a ground potential. Although the device 100 includes the second resistor R 2 as the pull-down resistor, the device may not include the pull-down resistor.
A first distance between the first via conductor V 1 and the first land 30 is defined as L 1 , and a second distance between the first and the second lands 30 , 31 is defined as L 2 , as shown in FIG. 3 . The relationship between the first distance L 1 and the second distance L 2 is explained as follows. Here, a relationship between a distance between the second via conductor V 2 and the third land 32 and another distance between the third land 32 and the fourth land 33 is similar to the relationship between the first distance L 1 and the second distance L 2 .
The electrostatic charge inputted from the input terminal 51 transmits to the first land 30 through the first wiring 21 . The static charge is reduced by the first resistor R 1 mounted between the first land 30 and the second land 31 . However, when the dimensions of the first resistor R 1 are small, for example, equal to or smaller than 2.0 mm×1.25 mm, the second distance L 2 between the first and the second lands 30 , 31 becomes short. In general, the electrostatic charge easily discharges as a distance between conductors becomes smaller. Thus, when the second distance L 2 becomes shorter, the static charge may easily discharge between the first and the second lands 30 , 31 . In this case, the electrostatic charge transmits to the input IC 60 through the first and the second lands 30 , 31 without reducing at the first resistor R 1 . Further, when the first resistor R 1 is small, the withstand energy of the first resistor R 1 is small. Accordingly, when the large static charge flows through the first resistor R 1 , the first resistor R 1 may be broken down.
Specifically, as shown in FIG. 4 , when the dimensions of the circuit board 10 are 4.5 mm×3.2 mm, the second distance L 2 is about 3.4 mm. In this case, the voltage of the electric discharge between the first land 30 and the second land 31 without reducing the electrostatic charge (i.e., the withstand voltage) is about 5.4 kV in case of positive polarity, or 6.4 kV in case of negative polarity. Accordingly, when the voltage is equal to or smaller than 5.4 kV in case of positive polarity and 6.4 kV in case of negative polarity, the electrostatic charge can be reduced by the first resistor R 1 .
When the dimensions of the circuit board 10 are 3.2 mm×1.6 mm, the second distance L 2 is about 2.2 mm. In this case, the voltage of the electric discharge between the first land 30 and the second land 31 without reducing the electrostatic charge is about 4.2 kV in case of positive polarity, or 5.0 kV in case of negative polarity. Accordingly, when the voltage is equal to or smaller than 4.2 kV in case of positive polarity and 5.0 kV in case of negative polarity, the electrostatic charge can be reduced by the first resistor R 1 .
When the dimensions of the circuit board 10 are 2.0 mm×1.25 mm, the second distance L 2 is about 11.0 mm. In this case, the voltage of the electric discharge between the first land 30 and the second land 31 without reducing the electrostatic charge is about 2.3 kV in case of positive polarity, or 2.5 kV in case of negative polarity. Accordingly, when the voltage is equal to or smaller than 2.3 kV in case of positive polarity and 2.5 kV in case of negative polarity, the electrostatic charge can be reduced by the first resistor R 1 .
When the dimensions of the circuit board 10 are 1.6 mm×0.8 mm, the second distance L 2 is about 0.8 mm. In this case, the voltage of the electric discharge between the first land 30 and the second land 31 without reducing the electrostatic charge is about 2.0 kV in case of positive polarity, or 2.0 kV in case of negative polarity. Accordingly, when the voltage is equal to or smaller than 2.0 kV in case of positive polarity and 2.0 kV in case of negative polarity, the electrostatic charge can be reduced by the first resistor R 1 .
As the dimensions of the circuit board 10 become smaller, the second distance L 2 becomes small. Thus, the voltage of the electric discharge between the first land 30 and the second land 31 without reducing the electrostatic charge becomes smaller. Therefore, to prevent the static charge from penetrating into the input IC 60 from the first land 30 without passing through the first resistor R 1 , and to protect the first resistor R 1 over the static charge from directly passing through the first resistor R 1 , the first via conductor V 1 as electrostatic-charge absorbing conductor is formed near the first land 30 . Here, the first distance L 1 between the first land 30 and the first via conductor V 1 is smaller than the second distance L 2 between the second land 31 and the first via conductor V 1 .
In the above case, since the first distance L 1 is smaller than the second distance L 2 , the electrostatic charge inputted from the input terminal 51 may easily discharge between the first land 30 and the first via conductor V 1 . The first via conductor V 1 is electrically connected to the inner layer ground pattern 40 . Accordingly, the electrostatic charge flows into the ground through the first via conductor V 1 . Thus, the static charge is safely removed.
Preferably, the first via conductor V 1 is disposed near a portion, at which electric field is concentrated. The portion at which the electric field is concentrated is, for example, a corner of the first land 30 . Since inequality electric field is formed at the corner of the first land 30 when the electrostatic charge is applied to the first land 30 , the electric field is concentrated at the corner. Thus, the discharge of the electrostatic charge may easily occur at the corner of the first land 30 . Accordingly, it is preferred that the first via conductor V 1 is disposed near the corner of the first land 30 . In this case, the discharge of the electrostatic charge is easily occurred between the first land 30 and the first via conductor V 1 , so that the electrostatic charge is much prevented from penetrating into the input IC 60 .
Alternatively, the first via conductor V 1 may be disposed on a portion facing the corner of the first land 30 , as shown in FIG. 3 . The portion facing the corner of the first land 30 is the nearest position so that the corner of the first land 30 is nearest portion of the first land 30 when a distance between the first via conductor V 1 and the first land 30 is determined. The electric field concentration is easily occurred in a direction facing the corner of the first land 30 , so that the discharge of the electrostatic charge is easily occurred between the first land 30 and the first via conductor V 1 . Thus, the first via conductor V 1 as the electrostatic-charge absorbing conductor easily absorbs the electrostatic charge.
More preferably, the corner of the first land 30 is sharpened so that the inequality electric field is easily formed at the sharpened corner of the first land 30 when the electric field is applied to the first land 30 . Thus, the electric field is concentrated at the sharpened corner, so that the discharge of the electrostatic charge is easily occurred at the sharpened corner.
The electrostatic-charge absorbing conductor, i.e., the first via conductors V 1 , may be disposed on a portion between lands, for example, the portion between the first and the second lands 30 , 31 , on which a circuit part such as the first resistor R 1 is mounted. In this case, the substrate area of the circuit board 10 can be effectively utilized.
Further, the electrostatic-charge absorbing conductor, i.e., the first via conductors V 1 , may be disposed under the circuit part such as the first resistor R 1 . In this case, the substrate area of the circuit board 10 can be effectively utilized.
Further, the device 100 includes one electrostatic-charge absorbing conductor, i.e., the first via conductors V 1 , the device 100 may include multiple electrostatic-charge absorbing conductors. In this case, when the electrostatic charge is inputted, the charge can discharge to multiple conductors, so that the charge is easily absorbed in the electrostatic-charge absorbing conductors.
The first distance L 1 between the first via conductor V 1 and the first land 30 is shortened as small as possible without providing a problem of arrangement of the circuit board 10 or the like. When first via conductor V 1 is approximated to the first land 30 , failure of the circuit board 10 such as short-circuiting between the first land 30 and the first via conductor V 1 through moisture in air may occur. Accordingly, it is preferred that the first distance L 1 between the first via conductor V 1 and the first land 30 is shortened as small as possible without raising the failure of the circuit board 10 . Specifically, when the dimensions of the circuit board 10 are 2.0 mm×1.25 mm, the first distance L 1 is set to be 0.5 mm so that the electrostatic charge is effectively absorbed in the first via conductor V 1 . This is because the second distance L 2 between the first land 30 and the second land 31 is about 1.0 mm, which is longer than the first distance L 1 . Further, in this case, the first land 30 is not electrically connected to the first via conductor V 1 through moisture or the like. When the first distance L 1 is equal to or larger than 0.25 mm, the first land 30 is not electrically connected to the first via conductor V 1 through moisture or the like.
Although the device 100 includes the inner layer ground pattern 40 connecting to the first and the second via conductors V 1 , V 2 as the electrostatic-charge absorbing conductor, the device 100 may include a power source pattern formed in an inner layer of the circuit board 10 or a conductive pattern connecting to a load, which is not deteriorated by the electrostatic charge substantially.
Second Embodiment
FIG. 5 shows a relationship between the first via conductor V 1 and the first land 30 , according to a second embodiment of the present invention. The shape of the first via conductor V 1 is different from that in FIG. 3 .
When it is difficult to form the first via conductor V 1 at a portion facing the corner of the first land 30 , a sharp tip portion is formed on the first via conductor V 1 so that the electric field is concentrated at the sharp tip portion of the first via conductor V 1 . The first distance L 1 between the first land 30 and the first via conductor V 1 is set to be shorter than the second distance L 2 between the first and the second lands 30 , 31 . Here, the shape of the first via conductor V 1 having the sharp tip portion is a tear drop shape.
In this case, when the electrostatic charge is applied to the first land 30 , the discharge of the static charge easily occurs between the first land 30 and the portion of the first via conductor V 1 , at which the electric field is easily concentrated. Accordingly, since the portion, at which the electric field is easily concentrated, is formed on the first via conductor V 1 , the electrostatic charge is prevented from penetrating into the input IC 60 , so that the device is protected from the electrostatic charge.
Preferably, the position of the first via conductor V 1 is near the portion of the first land 30 such as the corner of the first land 30 , at which the electric field is concentrated.
Although the shape of the first via conductor V 1 is the tear drop shape, the shape of the first via conductor V 1 may be another shape as long as the electric field is concentrated at a part of the first via conductor V 1 . For example, the first via conductor V 1 may include a part having a right angle.
Third Embodiment
FIG. 6 shows a relationship between the first via conductor V 1 and the first land 30 , according to a third embodiment of the present invention. The shape of the first via conductor V 1 is different from that in FIG. 3 . As shown in FIG. 6 , the first via conductor V 1 includes a sharp tip portion as an electric field concentration portion. The first land 30 includes a corner as the electric field concentration portion. The first distance L 1 between the first land 30 and the first via conductor V 1 is shorter than the second distance L 2 between the first and the second lands 30 , 31 . The electric field concentration portion of the first via conductor V 1 faces the electric field concentration portion of the first land 30 , i.e., the sharp tip portion of the first via conductor V 1 faces the corner of the first land 30 .
In this case, the electrostatic charge is effectively absorbed in the first via conductor V 1 as the electrostatic-charge absorbing conductor.
Fourth Embodiment
FIG. 7 shows a relationship between the first via conductor V 1 and a surface layer ground pattern 70 , according to a fourth embodiment of the present invention.
The surface layer ground pattern 70 includes an exposed portion 72 as the electrostatic-charge absorbing conductor.
When the surface layer ground pattern 70 is formed on a side of the circuit board 10 , on which the first land 30 is disposed, the surface layer ground pattern 70 works as an electrode pattern. A solder resist 71 or the like covers a conductor of the surface layer ground pattern 70 . A part of the solder resist 71 is removed so that the exposed portion 72 of the surface layer ground pattern 70 is formed. The first distance L 1 between the first land 30 and the exposed portion 72 of the surface layer ground pattern 70 is set to be shorter than the second distance L 2 between the first and the second lands 30 , 31 .
Thus, by using the part of the surface layer ground pattern 70 , i.e., the exposed portion 72 , the electrostatic charge discharges between the first land 30 and the exposed portion 72 when the electrostatic charge is inputted from the input terminal 51 . Accordingly, even when the electrostatic charge is inputted from the input terminal 51 , the electrostatic charge is effectively reduced. Preferably, the exposed portion 72 is disposed near the portion, at which the electric field is concentrated, such as the corner of the first land 30 . Further, the exposed portion 72 is disposed on a portion facing the corner of the first land 30 , at which the electric field is concentrated.
Although the exposed portion 72 has a right angle shape, the exposed portion 72 may have another shape such as a sharpened angle shape.
Although the device 100 includes the surface layer ground pattern 70 , the device may have other pattern such as a power source pattern formed on the surface of the circuit board 10 and a conductor pattern connecting to a load, to which the electrostatic charge does not substantially affect.
(Modifications)
A distance between the third via conductor V 3 and the fourth land 33 may be shorter than the second distance L 2 between the first and the second lands 30 , 31 . Here, the third land 32 is electrically connected to the input terminal 51 , and the fourth land is electrically connected to the third via conductor V 3 . In this case, when the electrostatic charge is inputted from the input terminal 51 , the electrostatic charge is absorbed into the first and the second via conductors V 1 , V 2 . Further, the electrostatic charge discharges between the third land 32 and the fourth land 33 so that the static charge is absorbed into the third via conductor V 3 . Accordingly, the device 100 is protected from the discharge of the electrostatic charge effectively.
Although the device 100 includes the resistor R 1 , R 2 for reducing the electrostatic charge, the device may have other elements such as a capacitor and a coil for reducing the electrostatic charge.
While the invention has been described with reference to preferred embodiments thereof, it is to be understood that the invention is not limited to the preferred embodiments and constructions. The invention is intended to cover various modification and equivalent arrangements. In addition, while the various combinations and configurations, which are preferred, other combinations and configurations, including more, less or only a single element, are also within the spirit and scope of the invention. | A circuit board includes: an input terminal for inputting a signal from an external circuit; a first land and a second land; and an electrostatic-charge absorbing conductor for absorbing an electrostatic charge. The first land is electrically connected to the input terminal. The second land is separated from the first land by a predetermined distance therebetween. A distance between the electrostatic-charge absorbing conductor and the first land is shorter than a distance between the first land and the second land. In the circuit board, the electrostatic charge is effectively absorbed into the electrostatic-charge absorbing conductor through the first land so that the electrostatic charge is prevented from negatively affecting on electric parts on the board. | 7 |
FIELD OF THE INVENTION
The invention relates to an absorbent structure for cleaning surfaces, which has regions or portions or mixtures of different material characterized as being primarily absorbent or primarily cleaning-active. The absorbent structure also having a carrier structure with cleaning-active material applied to it.
BACKGROUND OF THE INVENTION
Cleaning textiles, cleaning structures and wiping coverings consist predominantly of a mixture of the basic components, cotton and synthetic fibers. The mixture of both basic components is necessary since the components sometimes have conflicting properties. A wiping covering can achieve maximum performance when a large number of positive properties are combined in it.
There are several properties to take into consideration to achieve maximum performance of the cleaning textile, cleaning structure and wiping covering, such as water absorbency, dirt carrying capacity, abrasiveness, washability, and sliding behavior. The water absorbency of cotton is approximately 250% and that of synthetic fibers is virtually 0%. The dirt carrying capacity of cotton is good, whereas the dirt carrying capacity of synthetic fibers is poor, with the exception of microfibers and polypropylene fibers. The abrasiveness of cotton is very low, whereas that of synthetic fibers is high. Additionally, although cotton, polyester and polypropylene are washable up to 95° C., the washing stability of cotton is nevertheless poor, while that of polyester and polypropylene is good. Cotton also has pronounced shrinkage, whereas synthetic fibers exhibit low shrinkage. In addition, cotton displays poor sliding behavior, whereas that of synthetic fibers is good.
Even though cotton absorbs 250% of its own weight of water, a pure cotton fabric is highly unfavorable on account of its poor sliding behavior and its instability during washing. Although properties such as abrasiveness, shrinkage, sliding behavior and washing stability, can be adapted to many situations by appropriately selecting material fractions of cotton and synthetics, the water absorbency is nevertheless, less than 250% when various mixtures of cotton and synthetics are used.
A flat wiping covering for the care of hard floor surfaces, includes a carrier fabric to which material portions are stitched on the underside and on which holder push-in pockets are stitched on the top side of the longitudinal ends is known from DE 38 09 279 C1. This describes a wiping covering for floor care, preferably having a carrier fabric with holder push-in pockets stitched on the top side of the longitudinal ends of the carrier fabric and material attached on the underside of the carrier fabric for the absorption of dirt and moisture. The wiping covering has a low dead weight, good absorbency and a high water storage capacity. In this case, the underside material is in the form of sponge or nonwoven-cloth material with high liquid absorbency. The sponge or non-woven cloth material form a plurality of strips extending over the length of the carrier fabric and are arranged in rows adjacent and parallel to one another. The strips of sponge or non-woven cloth material being attached to the carrier fabric by stitching. The water absorbency of the sponge or nonwoven cloth material is up to 3,600 g/m 3 , and the relative water absorption of the sponge or nonwoven cloth material is up to 1,400%. The water absorbency being determined according to DIN 53 923.
However, there is room for improvement in the flat wiping covering according to DE 38 09 279 C1. Considerable problems can arise in the handleability of the flat wiping coverings since the strips of sponge or non-woven cloth material are stitched to the carrier fabric, for example, reversible shrinkage of 30% in relation to the wet state can occur upon drying. In the wet state, the coverings have a calculated length, in which the covering sheet of the carrier material is flat. In the dry state, shrinkage of the sponge cloth lamellae of approximately 30% in relation to the cotton/polyester carrier fabric of the covering sheet occurs, leading to extreme distortions of the covering upon drying. The large degree of shrinkage of the sponge or non-woven cloth materials upon drying creates difficulty when inserting the wiping covering device into the holder push-in pockets of the carrier fabric. Nevertheless, forcibly inserting the wiping device into the holder push-in pockets damages the wiping covering. Even though the covering can be dampened before the wiping covering device is inserted into the push-in pockets of the covering, this is nevertheless disadvantageous since it entails a considerable amount of time and effort in handling. A further disadvantage is that the sponge or non-woven material is stitched onto the carrier fabric resulting in the water absorbency of the material being markedly reduced in the vicinity of the seams.
An improvement in water absorbency or water absorption-power was achieved, for example, in the patent specification DE 38 09 279 C1, already mentioned above, in that, in addition to cotton and synthetic material, a sponge or nonwoven cloth material with a high viscose fraction is also used. Water-absorbing materials, such as sponge or wood, work by replacing their air filled cavities in the dry state with liquid, when they are dipped into a liquid. This liquid absorption, however, is necessitated by the dipping of the material into the liquid, making it difficult for cleaning liquid to be absorbed from hard floor surfaces when the water-absorbing materials are in their dry state. The water-absorbing materials in the dry state even fail to appreciably absorb liquid in the case of a residual quantity of 15 g of cleaning liquid per square meter, which amounts to only fractions of a millimeter of thickness, since liquid absorption is necessitated by dipping the material in the liquid. Moreover 15 g of cleaning liquid per square meter represents an unacceptable level of moisture for coated PVC floors.
It is therefore necessary to have a different form of water absorbency which may be described by water suction capacity, for a wiping covering absorbing cleaning liquid. In this case, the material picks up the liquid on the contact interfaces via the suction effect, so that the liquid is downright sucked up. While a residue of 15 g of cleaning liquor per square meter on hard floor surfaces represents an unacceptable level of moisture, the aim is to achieve a residual liquid quantity of 10 g/m 2 . It was observed that, in the case of a residual moisture of 11 g/m 2 , the cleaning performance falls abruptly.
This negative jump is explained by the free movability of the pigment dirt in the relatively higher moisture film on the wiping surface. This possibility is eliminated below 11 g/m 2 . The dirt can no longer escape from the wiping materials, but, instead, during the wiping movements, it adheres to the material of the cleaning-active side and can be removed in this way.
SUMMARY OF THE INVENTION
The object of the invention is to provide a solution which, in the case of an absorbent structure for the cleaning of surfaces, affords, in terms of its design possibilities, variations and variabilities which are broadened in respect of its cleaning-active and absorbent properties and or actions.
In an absorbent structure of the type initially mentioned, this object is achieved according to the invention in that the structure has a pocket-shaped or bag-shaped cavity with snippets or strips of highly absorbent material arranged in it.
The invention affords the possibility of arranging the primarily absorbently active material with highly absorbent properties on the absorbent structure elsewhere and independently of the regions or portions with material having primarily a cleaning-active effect. Preferably and in particular, the highly absorbent material is formed and arranged on the opposite side of the cleaning-active surface of the primarily cleaning-active material. Since the cleaning-active materials are separate and placed independent of the highly absorbent material, the cleaning-active material can be designed specifically for its cleaning-promoting action, while the highly absorbent material can be specifically designed for its water absorption action or the absorbency action.
The cleaning structure according to the invention has, overall, a very high liquid absorbency as a result of the snippets or strips which, in particular, are loosely arranged within the closed cavity. The properties of the cleaning structure, such as abrasiveness, dirt carrying capacity, sliding behavior, etc., are determined by the properties of the primarily cleaning-actively acting material. In this way, the positive properties both of the cavity content, to be precise of the highly absorbent snippets, and of the outer material, including the carrier structure, are combined and optimized, without their respective properties having an adverse influence on one another.
In one embodiment, the invention provides for the snippets or strips to be arranged loosely in the cavity, with the cavity being closed on all sides.
A particularly preferred use of the absorbent structure is its design as a flat wiping covering for the care of hard floor surfaces.
In the known abovementioned flat wiping covering, the technical problem is also, in particular, that of incorporating highly absorbent materials with other materials having different materials properties. In particular, the disadvantages of the highly absorbent materials having increased shrinkage upon drying in comparison with the low shrinkage of the carrier sheet material. It is an object to of the invention to provide a wiping covering that avoids the disadvantages arising from the different shrinkage behavior and from the impairment of the water absorbency in the seam region.
To solve this problem the invention provides the absorbent structure be designed as a flat wiping covering for the care of hard floor surfaces. The absorbent structure includes a carrier structure, to which material portions of cleaning-active and/or absorbent material or material combinations are stitched on the underside and to which holder push-in pockets are stitched on the top side of the longitudinal ends of the carrier structure. The carrier structure being absorbent or water-permeable. The absorbent structure also including a covering sheet, in which all sides of the covering sheet are stitched to the top or upper side of the carrier structure, forming a cavity between the carrier structure and the covering sheet. The cavity being filled with snippets or strips of highly absorbent material loosely arranged on the carrier structure.
The advantage of a flat wiping covering of this type is that, overall, it has a very high liquid absorbency, to which contribute in each case the material portions attached to the carrier structure on the underside, the carrier fabric and, predominantly, the snippets arranged loosely on the carrier fabric. The flat wiping covering is consequently suitable both for wiping wet hard floor surfaces and for applying cleaning liquid to the hard floor surfaces. In this case, the transport of liquid between the individual covering parts takes place via the absorbent material parts.
For example, when wet surfaces are being wiped, the liquid is first sucked up from the surface by the underside material portions and transferred from these to the carrier fabric and transferred from the carrier fabric to the snippets arranged on the carrier fabric.
The wiping covering is dipped into a container having the cleaning liquid prior cleaning a floor, so that the absorbent parts of the covering are saturated with the washing liquid. When the flat wiping covering is set down with the aid of the wiping appliance, the underside material portions come into contact with the floor first. As soon as these and, as a result, the carrier fabric have discharged the liquid stored in them, brief pressure on the snippets is subsequently sufficient to express the liquid stored in them and discharge it via the carrier fabric and the underside of the carrier fabric to the material portions and onto the surface to be cleaned.
Since the absorbency and the liquid transportability are accomplished by the cotton fraction present in the mixture of the material portions and the water storage capacity is accomplished primarily by the highly absorbent snippets or strips present in the covering it is possible to at least partially replace the material portions on the underside of the carrier sheet with nonabsorbent materials, for example synthetic fibers. The use of synthetic fibers enhances other properties important for the cleaning performance, such as abrasiveness and/or sliding behavior. The use of synthetic fibers also improves the shrinkage stability and washing stability of the material mixture of the absorbent structure.
Moreover, since the snippets of highly absorbent material are arranged loosely in the cavity and on the carrier fabric, the difference in shrinkage behavior properties does not have an effect on the dimensional stability of the coverings.
Preferably, the cleaning-active material or the material portions of this kind are in the form of fringes, loops, rat's tails or lamellae. It is also preferred that it or they be arranged, distributed, over the entire underside surface of the carrier fabric.
It is proposed, furthermore, that the cleaning-active material or the material portions of this kind consist of a synthetic material, in particular polyester, or microfibers or cotton or a mixture of these substances. The choice of materials depends on the desired cleaning properties.
It is particularly advantageous, furthermore, if the flat wiping covering has a peripheral bead which consists, in particular, of the same material as the material portions attached to the carrier fabric. Particular advantages arise when the bead is stitched in the form of a hem to the flat wiping covering in such a way that the edge of the longitudinal strip/longitudinal strips which projects into the middle of the underside of the covering lies loosely on this underside. This results in two different effects, depending on the wiping direction. The front longitudinal strip of the bead lies flat and is between the underside and the wiping surface. By contrast, the opposite, that is to say rear longitudinal strip of the bead rises up and thereby forms a stripper which increases the cleaning performance even further.
In a further important advantageous embodiment, the cavity has a plurality of, in particular two to five, chambers for the snippets or strips. The subdivision of the wiping covering into a plurality of chambers allows a more uniform distribution of the snippets, even when the covering is subjected to differing stress. Without this subdivision, it could happen that, for example in a wiping covering, the snippets or strips slip toward one end of the usually elongate flat wiping covering, so that the other end will be free of snippets. It is advantageous, moreover, if these chambers are divided off in the longitudinal direction. Such a division does not lead to an impairment of the cleaning performance. If the pockets were divided in the transverse direction, the corresponding seams would give rise to depressions on the cleaning-active side of a wiping mop, so that the contact of the wiping covering with the surface to be wiped would be prevented there and the wiped surface would acquire a stripy appearance.
Furthermore, it is also proposed, for a flat wiping covering, that the holder push-in pockets be stretchable. The wiping covering can thus be used both for fold-down holders and for rigid holders. In the latter case, it is necessary for the holder push-in pockets to be stretchable.
The invention does not, however, relate only to flat wiping coverings. The absorbent structure for the cleaning of surfaces may also be provided, in another particularly advantageous refinement, for manual use, that is to say without wiping appliances being employed. For this purpose, it is proposed that the absorbent structure for the cleaning of surfaces be designed as a bag, and that the carrier structure have on its outside bristles, in particular synthetic bristles, as cleaning-active material. This bag is capable, on the one hand, of sucking up a large quantity of water and, on the other hand, of holding it and discharging it onto the surface to be wiped. At the same time, the outside provided with bristles ensures a good cleaning action. The bristle trimming brings about the necessary abrasiveness. Dirt particles are removed from the smallest depressions of the surface being wiped by means of the bristle ends. An absorbent structure of this kind, having a bag-shaped cavity, can easily be produced as a sponge substitute in a size suitable for grasping with one hand.
Moreover, both as regards the sponge bag and as regards the flat wiping covering, it is advantageous if the snippets or strips of highly absorbent material suck up 250 to 1,500% of their own weight of liquid.
It is advantageous, furthermore, if the highly absorbent material consists at least predominantly of viscose, as also provided by the invention.
In a further embodiment, the invention provides a system which consists of the absorbent structure of the present invention and of a wiping device with a handle and a wiping plate, connected or connectable to the handle via a preferably cardanic joint, for holding the absorbent structure on an underside of the wiping plate, and of an expressing device for the wiping device, the expressing device having a bearing surface provided with perforations and a counterbearing means arranged at a distance from said bearing surface, so that the wiping plate can be introduced between the bearing surface and the counterbearing means with a downwardly directed introduction movement and can be pressed, with its underside holding the absorbent structure, against the bearing surface by tilting, being supported at the same time on the counterbearing means. A wiping device of this kind and an expressing device of this kind, which cooperate in the way described, are known from WO-A-98/06316 and GB-C-330 543 and also from the Applicant's German patent application 100 13 044. Express reference is made thus far to the disclosure content of these publications.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments of the invention are described in more detail below with reference to drawings in which:
FIG. 1 shows a perspective illustration of a flat wiping covering according to the invention in a first exemplary embodiment, in an oblique view from above,
FIG. 2 shows a plan view of the top side of a flat wiping covering according to a second exemplary embodiment of the invention,
FIG. 3 shows a plan view of the underside of the flat wiping covering according to FIG. 2 ,
FIG. 4 shows a plan view of a cleaning structure according to the invention (third exemplary embodiment) designed as a bag,
FIG. 5 shows part of a bristle row on the top side of the bag according to FIG. 4 , and
FIG. 6 a / 6 b show diagrammatic sectional views of an expressing device.
DETAILED DESCRIPTION OF THE INVENTION
In all the drawings, identical parts have the same reference symbols and, if appropriate, are not mentioned separately for each drawing.
It was shown, in tests, that viscose sucks up 15 times its own weight of liquid without mechanical action from outside, such as compression and expansion. These measurements were conducted with reference to DIN 53 923 and, in addition to this relative liquid absorption, showed wetting times of less than four seconds and a suction rate of more than 5 cm/s. Depending on the fraction of viscose in material mixtures with cotton, the liquid absorption capacity of the mixture is around 2.5 to 15 times its own weight, corresponding 250 to 1,500%. Snippets or strips of such a highly absorbent material are used as material having a highly absorbent action in the exemplary embodiments of the invention which are described below.
In FIG. 1 , an absorbent structure for the cleaning of surfaces in the form of a flat wiping covering is illustrated in an oblique view from above. In the case of the flat wiping covering, a covering sheet 5 is applied to a carrier structure 6 , and stitched all-around the edges of the covering sheet to the carrier structure 6 designed as a woven or knitted fabric, referred to as a carrier fabric in the case of the flat wiping covering. Fastened to the carrier structure on the underside are material portions which consist of a material acting in a primarily cleaning-active way, that is to say having an abrasive, scouring and/or dirt-absorbing action, and which, in the exemplary embodiment illustrated, are in the form of fringes. However, these material portions way also have some absorbency. Holder push-in pockets 2 are stitched to the covering sheet 5 at the longitudinal ends. FIG. 1 illustrates a cutout 4 of the covering sheet 5 , so that it is possible to look through the opening 7 at snippets 1 arrange loosely on the carrier structure. These snippets 1 lie on the carrier structure 6 in a pocket-shaped cavity formed by the stitched-on covering sheet 5 and the carrier structure 6 .
The ends of a folding holder can be pushed into the stitched-on holder push-in pockets 2 for fastening. By means of the spread: folding holder, during wiping, a surface pressure can easily be exerted on the covering sheet 5 and consequently on the highly absorbent snippets 1 arranged below the covering sheet 5 and on the carrier structure 6 , in order, depending on the magnitude of the pressure exerted, to express completely or partially a liquid quantity which is stored in the material. In exactly the same way, before the flat wiping covering is used for dry wiping, the stored liquid can be expressed from the flat wiping covering by corresponding pressure with the folding holder, so that the flat wiping covering has full suction capacity for wiping up.
FIGS. 6 a and 6 b show a diagrammatic sectional view of an expressing device 29 suitable for this purpose, in FIG. 6 a during the introduction of the wiping plate 24 and in FIG. 6 b during the expressing of the flat wiping covering 25 . FIG. 6 a illustrates the introduction movement 34 , by means of which the wiping device or its wiping plate 24 is introduced, with a longitudinal edge 22 in front, into the expressing device 29 and between the bearing surface 31 provided with perforations and the counterbearing means 33 or its counterbearing elements 33 . The holding portions 28 assigned to or adjacent to the introduced longitudinal edge 22 are thereby brought into engagement with the counterbearing means 33 or its counterbearing elements 33 or engagement in this respect becomes possible, so that securing portions 35 , protruding or projecting relative to the bearing surface 31 , of the counterbearing means or of the counterbearing elements 33 engage or can engage behind the introduced holding portions 28 or their undercuts.
How far the introduction movement 34 must involve a pivoting or tilting of the wiping plate 24 about its longitudinal axis depends on the clear distance A of the securing portions 35 from the bearing surface 31 in relation to the overall height of the wiping plate 24 together with the flat wiping covering 25 and with the holding portions 28 projecting the highest on the top side. Preferably, as indicated in FIG. 6 a , inward pivoting is necessary, so that the wiping plate 24 is secured positively against moving out of the expressing device 29 when the wiping plate 24 together with the flat wiping covering 25 lies over its full area on the bearing surface 31 , as shown in FIG. 6 b.
It may also be gathered from FIGS. 6 a and 6 b that the expressing device 29 , illustrated in its state of use, is designed in such a way that the bearing surface 31 is inclined at an angle β relative to the horizontal 37 . Preferably, the angle of inclination is between 30° and 60°, in particular about 45°. In combination with a counterbearing means arranged in the lower region, here in the region of the lower longitudinal edge 36 , this results in a simple introduction and expressing of the wiping device.
FIG. 6 b illustrates the expressing device. With the wiping plate 24 introduced, the handle 32 is folded down or pivoted about the longitudinal axis away from the counterbearing means according to the arrow 38 . The handle 32 or part of the joint in this case comes to bear on the wiping plate 24 , here, for example, in the region of the V-shaped recess 18 , so that further pressure on the handle 32 in the direction of the arrow 38 results in the wiping plate 24 being pressed down with its underside toward the bearing surface 31 , as a consequence of which the flat wiping covering 25 is expressed. In this case, the counterbearing means or its securing portions 35 cooperate, in particular in a hinge-like manner, with the introduced holding portions 28 of the wiping plate 24 , the counterbearing means forming virtually the pivot point for a one-armed lever formed from the wiping plate 24 and the adjoining handle 32 . By means of this one-armed lever, it becomes possible for the flat wiping covering 25 to be expressed in a simple way on the articulated wiping device.
The transport of liquid during liquid absorption and during liquid discharge takes place via the absorbent parts of the flat wiping covering. In particular liquid moves from the underside material portions of primarily cleaning-active material to the at least water-permeable carrier structure to the snippets 1 and/or strips arranged on the carrier structure, and vice versa. There is no need for the material of the holder push-in pockets 2 and the covering sheet 5 to be absorbent and to have liquid absorbency.
Only the fringe-like material portions 3 arranged along the edge can be seen in FIG. 1 . The material portions may also be in the form of loops, rat's tails or lamellae and, as a rule, are arranged so as to be distributed essentially over the entire underside surface of the carrier structure 6 . The underside material portions may be arranged in a straight line next to one another or along circular or zigzag paths next to one another.
Since the liquid absorbency of the underside material portions having a primarily cleaning-active action make up only a relatively small fraction of the liquid absorption capacity of the entire flat wiping covering, while the snippets or strips arranged loosely in the pocket make up a very large fraction or the essential fraction of the liquid absorption capacity, the fraction of absorbent materials in these underside material portions may be reduced in favor of the fiber fractions which positively influence other necessary properties, such as abrasiveness and slidability.
FIG. 2 shows a plan view of the top side of a particularly preferred exemplary embodiment of a flat wiping covering according to the invention. The highly absorbent snippets 1 , which cannot be seen in this figure, are arranged in two chambers 7 a , 7 b which extend in the longitudinal direction and which are delimited at the top by the covering sheet 5 and on the underside by the carrier structure 6 ( FIG. 3 ). The two chambers 7 a and 7 b are divided off by a continuous longitudinal seam 8 . This longitudinal seam also runs below the holder push-in pockets 2 which, in the present case, are designed elastically.
The carrier structure 6 on the underside of the flat wiping covering ( FIG. 3 ) consists, here, of a microfiber with a pile height of 2 to 10 mm. The term “pile height” relates to the length of the outwardly protruding loops or fringes.
A peripheral bead, which is formed by two longitudinal strips 9 and two transverse strips 10 , consist of the same material. The transverse strips 10 are stitched at their outer edges to the covering sheet 5 or the carrier structure 6 . This is indicated by the seams 11 passing through the flat wiping covering. In contrast to this, the two longitudinal strips 9 are stitched to the covering sheet 5 , in the region of their edges, only on the top side of the flat wiping covering. The corresponding longitudinal seams bear the reference symbol 12 . By contrast, on the underside, the longitudinal strips 9 are significantly wider, and the longitudinal seams 12 , which, like the transverse seams 11 , pass through the entire flat wiping covering, lie nearer to the edge of the flat wiping covering than to the edges to the longitudinal strips 9 , so that a relative wider part region 13 projects, unstitched, into the middle of the covering on both longitudinal sides of the latter.
When wiping transversely to the longitudinal direction of the covering, the two longitudinal strips 9 behave differently. The front longitudinal strip lies flat, between the carrier structure 6 and the wiping surface. By contrast, the unstitched edge of the wider region 13 of longitudinal strips 9 located further to the rear can move and form a stripper which absorbs liquid and dirt and thereby increases the cleaning performance.
It may also be pointed out that, in the present exemplary embodiment, the covering sheet 5 and the carrier structure 6 consist of different material. The covering sheet 5 consists of a firm woven textile. It is also possible, however, to use only microfiber or another cleaning-active textile both for the covering sheet 5 and for the carrier structure 6 .
FIGS. 4 and 5 illustrate diagrammatically a further exemplary embodiment of the invention. Here, the absorbent structure for cleaning surfaces consists of a bag filled with the highly absorbent snippets or strips. This exemplary embodiment is intended advantageously to replace a conventional sponge.
To be precise, conventional known sponges do not suck up any water, for example, as a result of capillary action. The foamed body of conventional sponges admittedly has a large number of open pores and, when the sponge is immersed, water runs into these cavities. This operation can be accelerated if the sponge is dipped in the compressed state under water and is expanded there. Sponges which are covered on one side with a pad are also known. The actual sponge body serves as a grip for handling an abrasive scouring pad of this kind. However, wet surfaces cannot be dried off with sponges of this kind.
In contrast to this, the bag according to the invention is suitable not only for cleaning of surfaces, but, in addition, for wiping dry, as a result of its high-suction snippets or strips as material having a primarily absorbent action.
The outer casing of the bag 14 in FIG. 4 , said casing surrounding the snippet-containing cavity on all sides, is formed by the carrier structure 6 which is water-permeable and which carries a close-mesh bristle trimming 15 , 16 . The bristles 15 , which are arranged in rows 16 on the carrier structure 6 , bring about the desired abrasiveness, that is to say have a primarily cleaning-active action. A bristle row 15 , 16 of this kind is illustrated, enlarged, in FIG. 5 . Dirt can be removed from the smallest possible depressions by means of the bristle ends. The bristles may also have some absorbency.
The bristles are preferably 1 to 10 mm long and consist of a synthetic material, so that, in the sanitary sector, fittings are protected and are not scratched.
The bag 14 is filled with the highly absorbent snippets of sponge cloth material, already discussed above, as material having a primarily absorbent action, which are capable of sucking up preferably up to 1,500% of their own weight of water. The bag according to the invention is therefore particularly suitable for drying off wet surfaces, since the snippet-like or strip-shaped material readily sucks up the water to be eliminated.
The individual materials or material portions of the absorbent structure may be produced as a textile, woven or knitted fabric.
Within the scope of the foregoing disclosure, the terms “absorbent” and “absorbency” also mean “water absorbent” or “water absorbency” or “water suction power” or “water suction capacity”, so that these terms are to that extent used as synonyms.
A particularly suitable material for the highly absorbent snippets/strips is pieces which are sold by the company Kalle/Nalo and are produced during the production of sponge cloths as waste pieces from their edge region and which consist ⅔ of viscose and ⅓ of cotton fibers, preferably for dimensional stablization. | The invention relates to an absorbent structure for cleaning surfaces. The absorbent structure has areas or sections or mixtures comprising different material, these areas, sections or mixtures having either a primarily absorbent effect or a primarily cleaning effect. The structure has a support structure to which the cleaning material has been applied. The aim of the invention is to provide an absorbent structure with greater potential for variation and variants in terms of its cleaning and absorbency properties and/or effects. To this end, the inventive absorbent structure has a pocket or bag-shaped cavity in which pieces or strips of highly absorbent materials are located. | 0 |
BACKGROUND OF THE INVENTION
The invention relates to a conveyor track for pallets, in particular for transporting workpieces, the pallet being driven by a first drive means.
Conveyor tracks as described above are used, for example, in transfer lines for transporting workpieces mounted on the pallets between various machining stations. The workpieces, for example engine blocks, are fastened to the pallet and the pallet is transported, together with the workpiece, along a primary conveyor track to various machine tools having different functions. The machining stations are connected to the primary conveyor track by, for example, short secondary conveyor tracks. A control system ensures that the workpieces to be machined are allocated to the correct machining stations. For feeding-in and diverting the pallet from the primary conveyor track to the secondary conveyor track, it is generally necessary to lead the pallet away at right angles to the main conveying direction.
To this end, it is known to divert or transfer the pallets or similar carrying elements laterally, firstly by lifting them using an additional lifter and then placing them by means of the latter onto another, second transport system or conveying means which then conveys the pallets away. In this procedure, two movement operations are therefore necessary, which is correspondingly costly.
The invention has the object of improving a conveying path as described above, such that the pallet is transferred from one drive means to another drive means without the need for the costly transfer apparatus.
BRIEF SUMMARY OF THE INVENTION
To achieve this object, the invention on proposes further development of a conveyor track as described above such that a second drive means takes over the pallet, the second drive means lifting the pallet from the first drive means and then driving the pallet.
Through the lifting of the pallet, the pallet is freed from the first drive means. At the same time, the second drive means convoys the lifted pallet further.
The problems outlined above, involving costly constructions of a lifting mechanism and the like, are eliminated by this solution. The drive means thus fulfils two functions, of lifting and transporting. The second drive means may grasp the pallet from below, from the side or from above.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1a, 1b, 2a, 2b, 3a and 3b show various positions of the pallet on the conveyor track, (a) in plan view, and (b) in vertical section along each of the marked lines, and
FIG. 4 shows, in plan view, the slewing apparatus of the conveyor track according to the invention,
FIG. 5 show a section through the friction-roller chain of the rule conveyor track according to the invention,
FIG. 6 shows a plan view of a modified exemplary embodiment of the invention and
FIG. 7 shows a section through the representation of FIG. 6 on the line VII--VII.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In FIGS. 1, 2 and 3, various stages of the diversion of a pallet 1 on the conveyor track 2 are represented diagrammatically in various representations, in plan view (a) and in vertical section (b) In FIG. 1a, the pallet 1 to be diverted is drawn in heavier lines, while other pallets 10 on the conveying path 2 are marked in broken lines. The pallet 1 is to be diverted from the main conveyor track path 2 onto a secondary conveyor track 21 in the region of the points 20, in order to supply the workpiece provided on the pallet 1 to a place where it is subjected to a special machining operation. The branching possibility in the region of the points 20 is marked by the arrows 22.
As drive means 3 in the direction of the conveyor track 2 there is provided, for example, an endless circulating friction-roller chain. The drive means of the conveyor track 2 is denoted here as first drive means 31. The second drive means of the secondary conveyor track 21 is denoted here by 32.
FIG. 1b shows, in a vertical sectional representation, the pallots 10,11 lying on the second drive means 32. The drive means 32 in this embodiment is likewise in the form of a friction-roller chain. To this end, a multiplicity of friction rollers 33 are provided. In FIG. 1b, it is indicated that some of the friction rollers 34 have a greater diameter than the friction rollers 33. These friction rollers 34 are shown in the drawing in heavier lines. Of the pallets 10 lying on the drive means 32, only the one on the right is actually lying on the drive means. The pallet 11 on the left is not supported by the rollers 33. This pallet is still lying on the first drive means 31 of the main conveyor track 2, or on the slide track or conveyor track parts 131 which adjoin the drive means 31. Nor are the friction rollers 34 having the greater diameter in contact with the pallet 11, as indicated in FIG. 1b. The pallet 11 is therefore not yet being conveyed by the second drive means 32 onto the secondary conveyor track 21 either. The second drive means 32 is in a waiting position such that, when required, the part of the friction-roller chain having the larger friction rollers 34 can immediately be moved under the pallet 11 in order to lift it.
FIGS. 2a, 2b show that the pallet 1 which is to be diverted onto the secondary track 21 has come into the points 20. A sensor 4 provided on the conveying path 2 detects the pallet 1 which has arrived and causes the pallet 1 to be stopped. To this end, a stop, for example, may be swung into the conveyor track 2 and stop the pallet 1 without, however, influencing the conveying movement of the first drive means 31. Consequently, only the pallet 1 is stopped but not the pallets 10, which continue to move on the conveyor track 2. Nevertheless, it is also possible to stop the drive means 31. The pallet 1 which has arrived lies on the first drive means 31, or on the part 131. This can also be seen in FIG. 2b, since here the smaller friction rollers 33 are not in contact with the underside of the pallet.
The sensor 4 is connected to a conveyor track control system (not shown specifically). This conveyor track control system now switches on the drive for the second drive means 32. This is shown in FIGS. 3a, 3b. The conveying means 32 is driven here in the clockwise direction (arrow 35), for example, by an electric motor. Nevertheless, the pallet 1 can also be displaced forwards and backwards (indicated by the arrow 36) on the conveying means 32. If now the conveyor track control system causes the second drive means 32 to start up, the friction rollers 34 having the greater diameter travel under the pallet 1. The lower side of the pallet 1 comes into contact with the periphery of the friction rollors 34 and is lifted by the friction rollers 34. Through the further conveying movement of the drive means 32, the pallet 1 is, as shown in FIG. 3b, displaced to the right along the arrow 36.
At the same time, there may be provision by the control system for the following pallet 10 to be brought into the points 20.
In order to make the second drive means 32 available again for the lifting of the newly arrived pallet 10, there is provision for the conveying means 32, for example, to pass on the lifted pallet 1 after a short distance to a further following drive means in order then to return again to the starting position shown in FIGS. 1a, 1b. Thus, there may be provision for the pallet 1 then to travel, for example, against a stop, for the friction rollers 34 under the pallet to slide on and, when the region with the smaller rollers 33 follows, for the pallet 1 to be set down onto the downstream drive means. The appropiate control for the setting-down movement or passing-on of the pallet to following drive means etc. is also provided by the conveyor track control system.
The conveyor track according to the invention is so simple because only one simple conveying movement is necessary, which automatically effects the lifting when the conveying section having the greater height comes into contact with the pallet.
The feeding-in of a pallet which is being conveyed back from the secondary conveying path 21 onto the main conveying path 2 takes place in reverse steps.
FIG. 4, the slewing apparatus 5 is shown. The slewing apparatus 5 is used to turn the pallet 1, for example, through 90°. The slewing ensures that the front side 12, which, as indicated in this example, is oriented in the transporting direction, is also aligned in the transporting direction again after a lateral displacement. As a result, the orientation of the workpiece on the pallet is always the same in relation to the transporting direction. For the slewing of the pallet 1, the slewing apparatus is provided on the conveyor track 2, for example, at a distance upstream of points. The conveyor track 2 has, in its lateral guide strips 23, interruptions 24 which serve to accommodate the swung-out regions of the pallet 1. The pallet 1 is slowed about a slewing axis 50. The slewing axis 50 may, for example, be in the form of a bolt or pin which is vertically movable and is arranged, for example, on the conveyor track 2 or on the pallet 1. Accordingly, the slewing axis 50 engages in an opening of the conveyor track or of the pallet in order to fix this point of the pallet in relation to the conveyor track. The slewing movement of the pallet is effected by the first drive means 31. The drive means 31 are, for example, arranged in pairs on both sides of the conveyor track 2. If now, for example, on the side which is on the right in the conveying direction the pallet is held firmly by the slewing axis 50, the left-hand drive means 310 is still able to move the pallet 1 on. This results in a slewing or turning movement 51 of the pallet about the slewing axis 50. During this, the right-hand drive means slides through under the pallet. The slewing movement may be limited, for example, by an appropriate sensor control. It is, however, also possible to release the firm holding of the pallet 1 on the conveyor track 2 by the slewing axis 50 again when the slewed pallet rests against the guide strip 23 which is on the right (in the conveying direction 37).
If now there follows, for example downstream of this slewing apparatus, a displacement of the pallet at right angles, for example in order to travel around a corner, the side 12 again forms the front side of the pallet downstream of the corner. It is even possible, by connecting a plurality of the same slewing apparatuses one after the other, to turn the pallet through 270°, corresponding to a single turn through 90° in the other direction. There may also be provision for the slewing apparatus to be provided directly upstream of points and for the slewed pallet to be convoyed onto the points.
In FIG. 5, the construction for the mounting of the pallets on the drive means, the friction-roller chains, is shown in elevation. The friction-roller chain is denoted by 6. The chain 60 is supported by means of rollers, for example pairs 61 of rollers, on the outside of the link plates on a base 70. The link plates 60 carry rollers 33, 34 having different diameters. The rollers 34 serve, for their part, in turn as a support for the pallets. In particular the rollers 34 of greater diameter are designed as friction rollers, that is to say turning is only possible against a frictional resistance. To this end, a coupling, for example a slip clutch, friction clutch or the like, is provided between support rollers 33,34 and the supporting rollers 61. As a result, it is possible for the pallets to be taken along by the friction-roller chain, but the pallets which are retained by a stop do not hinder the operation of the drive means.
The base 70 is situated in a profile 7. The profile 7 has aprons 71 which cover the rollers 61, with the result that direct contact with the rotating rollers 61 is avoided. The profile 7 has a recess 72 into which the bearing rollers 33,34 project.
In FIGS. 6 and 7, a modified embodiment of the invention is shown. Whereas in the exemplary embodiments of FIGS. 1 to 5 friction-roller chains having friction rollers at different sizes were always used, the embodiment according to FIGS. 6 and 7 concerns a construction in which the second conveying means is formed by motor-driven, rotatable discs 80 or cylinders, which are eccentrically arranged.
FIG. 6, which shows a plan view, reveals that between the two parts of the conveyor track 2 there are mounted two shafts 83 which extend parallel to the conveying direction of the conveyor track 2. Although the parallel alignment of the shafts 83 with respect to the conveying direction of the first conveying means is advantageous for the invention, it is not absolutely necessary. In the case where the pallets are to be diverted not at right angles but at an acute angle, the alignment of the shafts 83 is to be adapted accordingly.
The shafts 83 are carried by bearing crosspieces 85, and one of the two shafts is driven by a motor 86. Fastened to both shafts are, for example, toothed rings 87, and a circulating chain 88 ensures that, when being acted upon by the motor, both shafts rotate in the same direction.
Discs 80 are arranged on both shafts, in pairs in each case, the form of which is apparent in particular from the representation of FIG. 7 and is described in greater detail below. As can be seen, pairs of discs are provided in each case at the two ends of the shafts 83, the spacings being adapted to the size of the support surface of the pallest 1, so that the pallets are supported in each case at the front and rear end.
In the embodiment shown in FIGS. 6 and 7, discs 80 are shown in each case. However, the discs could also be replaced by cylinders which extend, for example, over a substantial part of the length of the shafts 83. The use of discs is preferable, however.
As is apparent from the representation of FIG. 6, the discs 80 of the two shafts 83 are mutually offset. The discs could also be arranged at the same level. The offset arrangement has the advantage, however, that, if required, the discs can be dimensioned with such a size that the discs partially intermesh.
Mounted on the bridge 89 are, furthermore, controllable stops 90 and 91 which cooperate with counterstops 92 and 93 on the shafts 83 or discs 80, as is apparent in particular from FIG. 7.
In FIG. 7, can be seen that the discs 80 each have an eccentric form. Peripheral regions 81 having a slightly greater diameter and peripheral regions 82 having a slightly smaller diameter are provided, the said regions following each other.
It is clear that when the stationary discs 80 occupy a position as shown, for example, in FIG. 7, the discs 80 are not in contact with the pallet 1, rather the peripheral region 82 is at a distance from these pallets 1. The pallets, which are being moved on the conveyor track 2, i.e. from the bottom upwards in the representation of FIG. 6, thus do not come into contact with the discs 80.
If now a pallet is to be diverted from the conveyor track 2, the pallet in question is firstly stopped by a stop. This many be a stop which is moved by additional control means. The stop 84 which is driven by the shafts 83 may, however, in particular also be used for this purpose. The drive of the stop 84, which can he lifted and lowered, is not shown specifically in the drawing. The stop may, for example, be moved by a cam, a cog or by an eccentric arrangement. Other transmission means is are also possible. In particular, it is also possible to control the stop 84 by auxiliary means, for example electromagnets or the like.
The discs 80 may, for example, occupy a position in which the counterstop 93 comes to rest against the associated stop 91. In this position, for example the stopping stop 84 controlled by the shafts 83 is in an unblocking position. The discs 80 allow the pallet a clear passage in this position. If now the shafts are driven clockwise, for example until the counterstop 92 of the other shaft comes to rest against the associated controllable stop 90, although the region 82 still does not project into the path of the pallets 1, the stopping stop 84 is already lifted and will stop the next pallet which arrives. If now the stops 90 and, if appropriate, also the stop 91 are withdrawn and the shafts 83 are rotated further clockwise, the peripheral regions 81 of the discs 80 will lift the pallet 1, so that the latter comes free from the conveying means of the conveyor track 2. The pallet is, however, not only lifted thereby, but at the same time also moved in the direction of the arrow 95, so that the pallet can be taken hold of by the conveying means 96 which then conveys the pallet on.
In practice, it does not present ally difficulties to design the peripheral region 81 to be of such a size that a sufficient transporting distance in the direction of the arrow 95 is obtained. For example, approximately 300° to 330° of the periphery of the discs 80 may be utilized for this. Since, in the case of an arrangement in which the discs 80 intermesh, the diameter of the discs may be even greater than shown in the drawing, it is readily possible to obtain sufficient conveying distances.
As a rule, one revolution of the shafts 83 will be sufficient for a diverting operation. In special cases, the shafts for the diverting operation may also perform more than one revolution. Since the peripheral region 82 in each case leads to a setting-down of the pallets, contact with the rollers 33 can be avoided, for example, by additional supports.
In the embodiment shown, two shafts 83 are provided. The invention can also be realised with a greater number of shafts, but also with a single shaft 83. There may be provided additional means which guide the pallets and preclude undesired contact with the rollers 33. The arrangement of only a single shaft 83 having correspondingly large discs 80 is a means of increasing the conveying distance of the discs 80.
The further transporting facility 96, which takes over the pallets, may have a conventional design.
While the invention has been described in connection with what is considered to be the most practical and preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation permissible under the law to encompass all such modifications and equivalent structures. | A conveyor track for pallets, in particular for pallets which transport workpieces, comprises a primary conveyor track (2) and a secondary conveyor track (21). A pallet (1.0) is driven along the primary conveyor track (2) by firs drive means and along the secondary conveyor track by second drive means. The transfer operation between the two drive means is carried out by the second drive means automatically lifting the pallet (10) from the first drive means and transporting it on. | 1 |
This is a continuation of application Ser. No. 07/511,454 filed on Apr. 20, 1990, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to the field of phonosurgery and, more particularly, to implants, instruments and a method of implantation for surgically medializing a paralyzed or bowed vocal cord.
It is well known that sound is produced in human beings through the passage of air past a pair of vocal cords located in the larynx. Muscles in the larynx operate to vary tension in the vocal cords to regulate them to produce speech and prevent aspiration of foreign particles into the lung.
When one of the vocal cords becomes paralyzed or immobile, voice quality is impaired because tension in the vocal cord cannot be regulated. A controllable tension in the vocal cord or spacing between it and the operable vocal cord cannot be maintained to provide the necessary vibratory sounds required for speech. Vocal cord paralysis can be caused by cancer, trauma or other affliction which would render the vocal cord unable to be tensioned.
It has long been recognized that a paralyzed vocal cord can be repositioned or supported to remain in a fixed location relative to the other operable vocal cord so that unilateral vibration of the other vocal cord can result in acceptable voice patterns. A surgical procedure has been performed through the years by forming an opening in the thyroid cartilage and providing various means for supporting or repositioning the paralyzed vocal cord.
One approach has been to inject "TEFLON" into the paralyzed cord to increase its bulk. This procedure is considered unacceptable because of the inability of the injected "TEFLON" to close large glottic gaps and the tendency of "TEFLON" to induce fibrous reaction. It is also difficult to remove "TEFLON" from the paralyzed vocal cords, if necessary or desirable, at a later date.
A more acceptable approach has been found for supporting the disabled cord, which involves the use of a custom-fitted block of siliconized rubber known as "SILASTIC". The proper size and shape of the block are determined by the operating physician, who hand carves it during the surgical procedure, in order to fine-tune the ability of the patient to phonate or speak. Such blocks have taken the form of wedges which are totally implanted within the thyroid cartilage (see FIG. 3) or flanged plugs that can be moved back and forth in the opening in the thyroid cartilage to fine-tune the voice of the patient (see FIGS. 4 and 5).
Although these implants have proved successful and superior over the "TEFLON" injection method, dissatisfaction has been expressed because the surgical procedure requires too much time, either through custom sizing of an implant, difficulty in inserting the implant or lack of efficient method of locking the implant in place. This is a drawback because in order for a patient's voice to be fine-tuned, the patient must be kept under local anesthesia so he or she can produce sounds to test the positioning of the implant.
While being operated upon, the patient can only phonate a limited period of time so that the longer the operation and the more times the patient's voice has to be tested, the less likely that the patient's voice can be fine tuned to its optimum level. Vocal cord edema, due to a prolonged procedure, also interferes with an optimal surgical result. Therefore, there exists a need for an implant which can quickly and simply be sized and manipulated so it can be located in the proper position relative to the paralyzed vocal cord for fine tuning a patient's voice.
SUMMARY OF THE INVENTION
A phonosurgery implant, associated instruments and a method of implantation have been developed in accordance with the invention, which solve the problems discussed above. The implant, which is designed for insertion through an opening formed in the thyroid cartilage, includes an implant body formed of a biocompatible material. The body includes a contact surface which is adapted to exert pressure on, support and medialize a vocal cord upon insertion through the opening in the thyroid cartilage. The body is shaped so that it can move back and forth in the opening so the surgeon can position the body for optimum vocal cord operation.
The body includes a holding portion or neck projecting from the contact surface, the holding portion being shaped to be engaged and held by an instrument for inserting and placing the implant in the opening. A shim or holder is provided for engaging the insert and holding it in a fixed position in the opening for optimum vocal cord operation.
Before the implant is inserted, however, a series of sizing instruments can be used which have sizing heads identical in size and shape to a corresponding number of implant bodies. After an opening is formed in the thyroid cartilage, a physician can select one of the sizing instruments, insert it through the opening to a position adjacent to the vocal cord and have the patient phonate in order to determine whether the implant is of an appropriate size.
If the patient's phonation is close to being acceptable, the sizer can be moved back and forth in the opening for determining the optimum position of the implant. If the implant is not of the right thickness, another sizing instrument with a sizing head of a different thickness can be used and the procedure repeated.
After the optimum size and position of the implant are determined, the physician can easily remove the sizing instrument and select an implant which matches the size and shape of the sizing head. An inserter instrument with a notched head engages a cooperatingly-shaped holding portion of the implant and inserts it to the proper position within the opening in the thyroid cartilage.
While the implant is held in place, a shim or holder which is adapted to fit within the opening in the thyroid cartilage and engage the holding portion of the implant is moved into place, at which time a simple pushing of the physician's thumb moves a telescoping rod within the instrument to disengage the implant from the instrument. The skin over the thyroid cartilage is then returned to its proper position and the incision is sutured, which operates to hold the shim in place within the opening formed in the thyroid cartilage.
In this way, a solid backing reinforcement is implanted in minimal time for the paralyzed vocal cord so the patient has improved voice quality and a reduction in the occurrence of aspiration.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the invention can be obtained from the following detailed description of the preferred embodiments of the invention when considered in conjunction with the following drawings, in which:
FIG. 1 is a front view of a patient's neck with the thyroid cartilage shown by the broken lines;
FIG. 2 is a front view of the thyroid cartilage with an opening formed in it to allow access to one of the vocal cords;
FIG. 3 is a cross-sectional view of a neck of a patient as shown in FIGS. 1 and 2, and showing a wedge of material as used in the prior art;
FIG. 4 is a sectional view similar to that of FIG. 3 and showing a T-shaped piece of material to hold a piece of cartilage against the vocal cord as used in the prior art;
FIG. 5 is a closeup view of an opening formed in the thyroid cartilage to illustrate how the implant of Fib. 4 is inserted and moved to fine tune a patient's phonation;
FIG. 6 is a perspective view of an implant, including a body portion and shim, formed in accordance with the invention;
FIG. 7 is a frontal view of a thyroid cartilage showing how the implant of FIG. 6 is located in the opening;
FIGS. 8A-D are plan views of a typical set of sizing instruments used in accordance with the invention;
FIG. 9 is a partial view of a thyroid cartilage showing how a sizing instrument is used;
FIGS. 10A-D are plan views of a series of implants which correspond to the sizing instruments of FIGS. 8A-D;
FIG. 11 is a plan view of an inserting instrument for the implants of FIGS. 10A-D, with the engaging end enlarged to show the internal telescoping rod for disengaging the implant;
FIG. 12 is a perspective view showing an inserting instrument engaging an implant;
FIGS. 13A-D are plan views of a series of shims used for the implants of FIG. 10; and
FIGS. 14A-D are plan views of a series of shims similar to those in FIGS. 13A-D, but having open-ended openings.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows a patient with his or her chin tilted upwardly to illustrate the location of the thyroid cartilage 10 which defines the larynx in a neck 12, where the vocal cords are located. As shown in FIG. 2, in order to gain access to one of the vocal cords of the patient, an opening 14 is formed in one side of the thyroid cartilage 10. It should be understood that an opening 14 could be formed in either side of the thyroid cartilage 10, depending on which vocal cord is paralyzed.
FIGS. 3 and 4 are section views of the thyroid cartilage 10 and illustrate several types of implants which have been inserted in the prior art through an opening 14 in order to reposition a paralyzed vocal cord 16 so that it can be supported in a fixed position relative to an operational vocal cord 18 to allow the patient to phonate.
In FIG. 3, a wedge 20 formed of a silicon rubber material known as "SILASTIC" has been inserted to provide support for the vocal cord 16. The optimum size of the insert 20 is determined through trial and error with the physician removing and shaping the insert as the patient phonates to determine the optimum size and shape for the implant 20.
Another type of implant 22 is shown in FIG. 4 where a wedge of the same "SILASTIC" material is used to hold a piece of cartilage 24 against the paralyzed vocal cord 16 for the needed support. As shown best in FIG. 5, the wedge 22 is generally T-shaped and has a length and width generally similar to but smaller than that of the opening 14 to allow the implant to be inserted, as shown by arrow 23, and rotated to the position in FIG. 5, as shown by arrow 25, where it can be moved back and forth in the direction of arrow 26 to determine the optimum position. This is done after a satisfactory size is determined by inserting and resizing the implant. The implant is then sutured in place.
The present invention is an improvement over the implants and procedures shown in FIGS. 3-5. In accordance with the invention, an implant is provided as shown in FIG. 6 which includes a body portion 28 that is shaped and dimensioned to fit through a typical opening 14 formed in the thyroid cartilage and provide support for a paralyzed vocal cord.
The body 28 is generally a rectangular solid formed with a surface 30 for engaging the vocal cord and an H-shaped holding portion or neck 32 which can be held by a suitable instrument as described below. The body 28 also includes a sloped surface 34 to allow easy insertion through the opening 14. A holder or shim 36, which is sized to fit comfortably within the opening 14 for holding the body portion 28 in place, includes an opening 38 for receiving the neck 32 and holding the implant 28 at the optimum position within the opening 14 and against the paralyzed vocal cord 16.
FIG. 7 shows the implant 28 in place in opening 14 in the thyroid cartilage 10 where the body portion of the implant 28 is illustrated by broken lines to show its position behind the thyroid cartilage 10. The position of the shim 36 relative to the opening 14 is illustrated by showing the projected location through the elevational arrows 40. As discussed below, the operating physician has a series of shims 36 with openings 38 in different locations for holding the implant in various positions along the length of the opening 14.
As shown in FIGS. 10A-D, a series of implants 28A-D are provided to the physician so that the optimum implant can be used without the physician having to carve or otherwise shape one of the proper size. Determining the proper sized implant 28 is accomplished through the use of a series of sizing instruments 42A-D, shown in FIGS. 8A-D, with sizing heads 44A-D identical in size and shape to the body portions of a corresponding series of implants 28A-D as illustrated in FIGS. 10A-D.
As shown in FIG. 9, the sizer head 44 of a selected instrument 42 is easily insertable into the opening 14. The head 44 is rotated to where it is in the same position as the implant 28 as shown in FIG. 7. Afterwards, the physician has the patient phonate to determine the level of performance. If the performance is totally unsatisfactory, another instrument 42 with a different sizer head 44 is selected and the same procedure repeated.
When the selected instrument results in close to acceptable performance, the head 44 is moved back and forth in the direction of arrow 46 (FIG. 9) to determine the optimum position of the implant in the opening 14. After that location is determined and noted, the sizing head 44 is removed from the opening 14.
The physician then takes an inserter instrument 48 as shown in FIG. 11 for holding one of the implants 28A-D (see FIGS. 10A-D) which correspond with the sizing head 44 found to provide optimum performance. The instrument 48 has a notched holding end 50 with an opening 52 adapted to engage the neck 32 of the implant 28, which is formed in an "H" shape in cross-section. The notch 52 is sized to engage the H-shaped cross-section of the neck 32 with a slight friction fit so the implant can be held and inserted into the opening 44 shown in FIG. 12 and then rotated to the position shown in FIG. 7. The physician will then move the implant to the position along the length of opening 44 found to provide the best performance as determined through use of the sizer head 44.
The implant is retained in place in the opening 14 by one of the shims 36A-D (FIG. 13) selected with an opening 38 in the location which will fix the implant at the position in the opening 14 determined by the physician to provide optimum performance. As shown in FIGS. 13A-D, a series of shims 36A-D are provided with openings 38 formed to cooperate with the necks 32 on the implants 28A-D shown in FIGS. 10A-D, at various positions along the length of the opening 14.
The shims can be formed either with closed openings except for 36A as shown in FIGS. 13A-D or they can be U-shaped as shown in FIGS. 14A-D. An advantage of the shims in FIG. 13A and FIGS. 14A-D is that they can be placed in the opening 14 by the physician while the inserter instrument 48 holds the implant in place as shown in FIG. 12. If the shims of FIGS. 13B-D are used, they should be placed on the inserter instrument 48 before it engages the implant 28 and then slid down the neck 58 of the inserter into the final position shown in FIG. 7 after the implant is properly positioned.
After the shim 36 is in place, the physician can easily move a thumb control 60 on the handle of the inserter instrument 48 in the direction of arrow 62 in order to move a rod 64, which is telescopingly located inside the inserter instrument 48, to disengage the implant 28 from the notched holding end 50. After this is accomplished, the surgeon can suture the patient's skin over the opening 14 which will hold the shim and implant in place relative to the paralyzed vocal cord.
The implants 28 and shims 36 can be formed of any suitable sterilizible, biocompatible material. Preferably, they are formed of a calcium phosphate material known as hydroxylapatite which is light weight, rigid and has an outer surface compatible with adherence of tissue for permanently maintaining the implant in place. Other calcium phosphate materials such as bioglass or suitable ceramics or plastics could also be used, which are either porous to accommodate tissue ingrowth or dense. The instruments can be formed of any suitable, rigid, sterilizible material such as stainless steel.
Therefore, an implant, instruments and method are provided in accordance with the invention which allow for precise positioning of an implant for surgically repositioning a paralyzed vocal cord in minimum time. An advantage of the implant, instruments and method of the present invention is that a hard material such as hydroxylapatite can be used since the physician does not have to custom cut or carve the implant in order to provide the proper fit or to use a suitably sized piece of cartilage between the implant and the vocal cord in order to obtain proper phonation.
The foregoing description of preferred embodiments is considered to be exemplary and not limiting in any way and it is understood that the invention covers improvements and modifications which fall within the scope of the appended claims. | A phonosurgery implant is inserted through an opening in the thyroid cartilage to reposition and stabilize a vocal cord. An implant body is formed of a biocompatible material. The body includes a contact surface adapted to support a vocal cord upon insertion through an opening in the thyroid cartilage, the body being shaped to move in the opening so a surgeon can position the body for optimum vocal cord operation. The body also includes a holding portion away from the contact surface, the holding portion being shaped to be engaged and held by an instrument for inserting and moving the implant body in the opening. The holding portion is engaged and held by a shim in a fixed position in the opening and relative to the vocal cord. | 0 |
[0001] This application claims priority under 35 U.S.C. §119 to patent application no. DE 10 2013 211 615.2, filed on Jun. 20, 2013 in Germany, the disclosure of which is incorporated herein by reference in its entirety.
[0002] The disclosure relates to an internal gear pump. It is provided, in particular, as a hydraulic pump instead of usually used piston pumps in slip-controlled vehicle brake systems. Hydraulic pumps of this type are often called recirculating pumps, even if this is not necessarily correct. In slip-controlled hydraulic vehicle brake systems, a pump outlet, that is to say a pressure side of a hydraulic pump, is connected to a brake line which leads from a brake master cylinder to wheel brake cylinders. A brake pressure which is generated by way of actuation of the brake master cylinder prevails at the pump outlet.
BACKGROUND
[0003] Internal gear pumps have an internal gear, that is to say an internally toothed gearwheel, and a pinion, that is to say an externally toothed gearwheel, which is arranged eccentrically in the internal gear and meshes with the internal gear. The designation of the gearwheels as pinion and as internal gear serves to distinguish them. By way of rotation of driving of one of the two gearwheels, usually the pinion, the other gearwheel is also driven and the gearwheels convey fluid, in particular liquid, brake fluid in vehicle brake systems, in tooth spaces of the gearwheels from a suction side to a pressure side of the internal gear pump. This is known and is not to be explained in greater detail here.
[0004] Patent DE 196 13 833 B4 discloses one example of an internal gear pump of this type which is not provided, however, for hydraulic vehicle brake systems, but rather for hydraulic machines, in particular construction machines. In a crescent-shaped pump space which is delimited on the inside by the pinion and on the outside by the internal gear and extends in a circumferential section between the gearwheels of the internal gear pump, in which crescent-shaped section the gearwheels do not mesh with one another, the known internal gear pump has a separating piece, against the inner side of which tooth tips of teeth of the pinion bear and against the outer side of which tooth tips of teeth of the internal gear bear. The separating piece divides the pump space into a suction space which communicates with a pump inlet and into a pressure space which communicates with a pump outlet. On account of the typical crescent shape or semi-crescent shape, separating pieces of internal gear pumps are often called a crescent piece. A further designation is a filler piece. Internal gear pumps having a separating piece in the pump space are also called crescent pumps. Internal gear pumps without a separating piece which are also called annular gear pumps are also known. The disclosure can be realized both in a crescent pump and in an annular gear pump.
[0005] In a slip-regulated hydraulic vehicle brake system, an internal gear pump requires a non-return valve on or in the pump outlet, which non-return valve prevents, in the case of a stationary pump, that is to say when the slip control is not in operation, brake fluid flowing through the pump outlet into the internal gear pump and from a pump inlet out of the internal gear pump again counter to the conveying direction of the internal gear pump upon actuation of the brake master cylinder, as a result of which a brake pressure which is built up by way of actuation of the brake master cylinder is dissipated and a brake pedal would yield.
SUMMARY
[0006] The internal gear pump according to the disclosure has a cover for closing an installation space of the internal gear pump on an end side of the pinion and of the internal gear, it not being necessary for the cover to be arranged directly next to the pinion and the internal gear, but it rather being possible for one or more components to be situated between the cover on one side and the pinion and the internal gear on another side. The installation space of the internal gear pump is, for example, a depression in a hydraulic block of a slip-controlled vehicle brake system, into which the internal gear pump is installed, or an interior space of a pump housing, it being possible for a hydraulic block, into which an internal gear pump is installed, to be considered to be a pump housing of the internal gear pump. In particular, an installation space which is open only on one end side is provided for the internal gear pump, the other end side of which installation space is closed. The cover preferably but not necessarily closes the installation space sealingly.
[0007] According to the disclosure, a pump outlet of the internal gear pump leads through the cover and there is a non-return valve in the pump outlet in the cover, which non-return valve can be flowed through out of the internal gear pump and shuts counter to a return flow through the pump outlet into the internal gear pump. When the internal gear pump is at a standstill, the non-return valve prevents throughflow of the internal gear pump counter to its conveying direction from the pump outlet to the pump inlet. If the internal gear pump is used as a hydraulic pump of a slip-controlled, hydraulic vehicle brake system, the non-return valve prevents, in the case of a stationary internal gear pump, brake fluid flowing through from the brake master cylinder of the internal gear pump counter to its conveying direction upon actuation of the brake master cylinder, a throughflow of this type of the internal gear pump counter to its conveying direction and/or through the pump outlet into the internal gear pump being called a return flow.
[0008] The disclosure has the advantage of space-saving accommodation of a non-return valve in the pump outlet in the cover of the internal gear pump.
[0009] The subject matter of the disclosure provides advantageous refinements and developments.
[0010] One preferred refinement of the disclosure provides that the non-return valve has a damper for pressure oscillations of fluid in the cover of the internal gear pump, which fluid is conveyed by the internal gear pump. A space or volume, in which the non-return valve is accommodated, a movable, in particular sprung and/or elastic damper body or a small throughflow cross section in the pump outlet, for example in the manner of a throttle or orifice plate, can have a damping effect. The list is by way of example and is not conclusive.
[0011] Another preferred refinement of the disclosure provides that the internal gear pump has a filter in the pump outlet, which filter is arranged between the gearwheels of the internal gear pump and the non-return valve as viewed in the flow direction. The filter prevents solid particles, that is to say chips, particles, etc., passing out of the internal gear pump into the non-return valve, where they can lead to a leak of the non-return valve. Refinements of the internal gear pump according to the disclosure with the filter in the pump outlet are also conceivable without a non-return valve.
[0012] One development of the disclosure provides an arrangement of the filter in a pressure field. The pressure field is a typically flat, pressure-loaded depression which is situated on a side of a rotationally fixed and axially movable axial washer, which side faces away from the pinion and the internal gear, which depression extends in the circumferential direction in an arcuate or crescent-shaped manner over approximately the region or a part of the region of the pump space between the pinion and the internal gear. The pressure loading of the axial washer on the outer side loads the axial washer into bearing contact with end sides of the pinion and the internal gear, in order to seal the pump space laterally. The seal is not necessarily hermetically tight, but rather the axial washer bears against the end sides of the pinion, the internal gear and, if present, a separating piece, in a comparable manner to a hydrodynamic axial plain bearing, limited leakage out of the pump space between the pinion and the internal gear on one side and the axial washer on the other side being acceptable. A satisfactory compromise is to be found between low friction and satisfactory sealing action. Axial washers are also called thrust washers or control washers or plates. A washer or plate shape is not necessary for the disclosure.
[0013] One development according to the disclosure provides that the filter which is arranged in the pressure field has a supporting element for a pressure field seal, which supporting element supports the pressure field seal from the inside. The pressure field seal is a seal which encloses the pressure field and seals on the circumference. Slip-controlled hydraulic vehicle brake systems are evacuated for filling, before they are filled with brake fluid, in order to avoid inclusions of air. The evacuation can cause a vacuum in the pressure field. The supporting element of the filter according to the disclosure prevents the pressure field seal in the pressure field being displaced from the circumference of the pressure field to the inside and holds the pressure field seal in its position which encloses the pressure field on the circumference.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] In the following text, the disclosure will be explained in greater detail using one embodiment which is shown in the drawing, in which:
[0015] FIG. 1 shows an axial section of an internal gear pump according to the disclosure, and
[0016] FIG. 2 shows an enlargement of a detail according to rectangle II in FIG. 1 .
DETAILED DESCRIPTION
[0017] The internal gear pump 1 according to the disclosure which is shown in FIG. 1 has a pump shaft 2 which is mounted rotatably in a cover 4 by way of a bearing, a ball bearing 3 in the embodiment. The cover 4 is a cylindrical part with a flange 5 on one side. It has an axially parallel through hole 6 , the diameter of which is stepped multiple times, for guiding through the pump shaft 2 , which through hole 6 is eccentric in the cover 4 . A gearwheel which is called a drive wheel 7 here is pressed or arranged in a rotationally fixed manner in some other way onto an end of the pump shaft 2 which projects out of the cover 4 . The drive gear 7 meshes with a gearwheel which is called a driving gear 8 here and can be driven by way of an electric motor (not shown), optionally with a gear mechanism connected in between.
[0018] An externally toothed gearwheel which is called a pinion 9 here is arranged on the pump shaft 2 on another side of the ball bearing 3 to the drive gear 7 . The pinion 9 is arranged on the pump shaft 2 in an axially displaceable and rotationally fixed manner; in the embodiment, the axial displaceability and rotational fixing is achieved by way of a four-cornered shaft 10 , the disclosure not being restricted to this possibility. The pinion 9 is situated in an internally toothed gearwheel which is called an internal gear 11 here, is arranged in one plane with the pinion 9 and is the same width as the pinion 9 . The internal gear 11 is coaxial with respect to the cylindrical cover 4 and eccentric with respect to the pump shaft 2 and with respect to the pinion 9 , with the result that the pinion 9 and the internal gear 11 mesh with one another. In the case of a rotational drive of the pinion 9 with the pump shaft 2 , the pinion 9 also rotationally drives the internal gear 11 which meshes with it. The internal gear 11 is pressed into a bearing ring 12 which is mounted rotatably in the manner of a plain bearing in a hydraulic block 15 .
[0019] The pinion 9 and the internal gear 11 enclose a crescent-shape pump space 13 between them in a circumferential section, in which they do not mesh with one another. A semi-crescent-shaped separating piece is arranged in the pump space 13 , which separating piece divides the pump space 13 into a suction space and a pressure space. The separating piece is the same width as the pinion 9 and the internal gear 11 . The separating piece which is also called a filler piece or, on account of its shape, a crescent is situated outside the sectional plane and therefore cannot be seen in the drawing. By way of rotational driving of the pinion 9 and the internal gear 11 , the internal gear pump 1 conveys fluid, brake fluid in the embodiment, from the suction space in tooth spaces of the pinion 9 and the internal gear 11 on the inside and outside along the separating piece into the pressure space.
[0020] A seal arrangement with a sleeve seal 16 , a supporting ring 17 and a secondary seal 18 is arranged between the ball bearing 3 and the pinion 9 , which seal arrangement seals the pump shaft 2 in the cover 4 . The sleeve seal 16 is trumpet funnel-shaped and is arranged in such a way that it is loaded against the pump shaft 2 in the case of any pressure loading. The supporting ring 17 which is situated between the ball bearing 3 and the sleeve seal 16 has an annular end face which is curved concavely in accordance with a curvature of the sleeve seal 16 and against which the sleeve seal 16 bears. The secondary seal 18 is a sealing ring which is arranged in an end groove of an annular step of the through hole 6 in the cover 4 . The secondary seal 18 is situated on an outer circumference of the sleeve seal 16 on a side which lies opposite the supporting ring 17 and clamps an outer edge of the sleeve seal 16 between itself and the supporting ring 17 .
[0021] An axial washer 19 which bears against end sides of the pinion 9 , the internal gear 11 and the separating piece is situated between the seal arrangement 16 , 17 , 18 on one side and the pinion 9 and the internal gear 11 on the other side. The axial washer 19 has a through hole for the pump shaft 2 . The axial washer 19 is rotationally fixed and axially movable. In plan view, the axial washer 19 has the shape of a circular segment which is greater than a semicircle, a step being cut out of the circular segment at one corner. The axial washer 19 covers the separating piece and the pressure space of the pump space 13 on one side.
[0022] The cover 4 has a pressure field 20 on an inner side which faces the axial washer 19 , that is to say on an outer side of the axial washer 19 , which outer side faces away from the pinion 9 and the internal gear 11 . The pressure field 20 is a flat depression with an approximately semi-crescent-shaped form which extends approximately over the pressure space of the pump space 13 and over part of the separating piece. The pressure field 20 is enclosed by a pressure field seal 21 which seals the pressure field 20 between the cover 4 and the axial washer 19 . Instead of in the cover 4 as illustrated, the pressure field 20 can also be provided in the outer side of the axial washer 19 (not shown). The axial washer 19 has a through hole 22 which leads from the pressure space of the pump space 13 into the pressure field 20 . The pressure field 20 communicates with the pressure space of the pump space 13 of the internal gear pump 1 through the through hole 22 , with the result that the same pressure prevails in the pressure field 20 as in a pump outlet. By way of the pressure loading in the pressure field 20 , the axial washer 19 is loaded into sealing contact with the end sides of the pinion 9 , the internal gear 11 and the separating piece. In the manner of a plain bearing, the axial washer 19 bears against the end sides of the pinion 9 , the internal gear 11 and the separating piece, but it does not seal hermetically; an optimum or at least favorable ratio is to be selected between friction between the rotating pinion 9 and the rotating internal gear 11 on one side and the rotationally fixed axial washer 19 on the other side and a low leakage, which can be selected substantially by way of size, shape and position of the pressure field 20 . An angled-away bore in the cover 4 leads away from the pressure field 20 in an axially parallel manner for a short distance and subsequently radially to the outside to a circumference of the cover 4 . The through hole 22 in the axial washer 19 and the angled-away bore in the cover 4 are constituent parts of a pump outlet of the internal gear pump 1 . The angled-away bore in the cover 4 opens into an annular groove 23 in the abovementioned hydraulic block 15 , which annular groove 23 encloses the cover 4 at the level of the radial part of the angled-away bore. The annular groove 23 is intersected by an outlet bore 24 which is likewise made in the hydraulic block 15 and, like the annular groove 23 , is part of the pump outlet. The outlet bore 24 communicates via a separating valve with a brake master cylinder and via pressure build-up valves with wheel brakes. The separating valve, the pressure build-up valves, the brake master cylinder and the wheel brakes are not shown.
[0023] The separating valve and the pressure build-up valves are solenoid valves which are installed into the hydraulic block 15 , but outside the sectional plane, for which reason they cannot be seen in the drawing. The brake master cylinder and the wheel brakes are situated outside the hydraulic block 15 ; they are connected by way of brake lines.
[0024] On both sides of the opening of the angled-away bore on the circumference of the cover 4 and therefore on both sides of the annular groove 23 in the hydraulic block 15 , the cover 4 has two sealing rings 25 which are arranged in the circumferential grooves in the cover 4 and which seal on both sides of the annular groove 23 between the hydraulic block 15 and the cover 4 .
[0025] On an opposite side of the pinion 9 and the internal gear 11 to the axial washer 19 , the internal gear pump 1 has a thrust washer 26 which bears sealingly against the end sides of the pinion 9 , the internal gear 11 and the separating piece. The thrust washer 26 is arranged immovable, that is to say in a rotationally, radially and axially fixed manner in the hydraulic block 15 . The thrust washer 26 is circular. The thrust washer 26 has an eccentric, cylindrical through hole which is coaxial with respect to the pump shaft 2 and which forms a bearing 27 , in which an end of the pump shaft 2 which is remote from the drive gear 7 is mounted rotatably in the manner of a plain bearing. In order to mount the pump shaft 2 in the manner of a plain bearing, a sliding bearing bush (not shown) can be pressed into the hole 27 in the axial washer 26 or can be fastened there in some other way. Anti-friction mounting of the pump shaft 2 by way of an anti-friction bearing (not shown) in the thrust washer 26 is also possible.
[0026] By way of the pressure loading of the outer side of the axial washer 19 in the pressure field 20 , the axially movable axial washer 19 is loaded against the end sides of the pinion 9 , the internal gear 11 and the separating piece, and those end sides of the axially movable pinion 9 , of the axially movable internal gear 11 and of the axially movable separating piece which face away from the axial washer 19 are loaded against the facing inner side of the thrust washer 26 , with the result that the end sides of the pinion 9 , the internal gear 11 and the separating piece also bear sealingly against the thrust washer 26 . Here too, the contact is in the manner of a plain bearing, and the seal is not hermetic, but rather has a leak.
[0027] The hydraulic block 15 has a stepped blind bore as installation space 28 for the internal gear pump 1 , into which blind bore the gear pump 1 is inserted and is fastened, for example, by way of caulking. The hydraulic block 15 is part of a slip control means (not shown) of a hydraulic vehicle brake system. The hydraulic block 15 is a rectangular part which is made from an aluminum alloy and has a second depression as installation space 28 for a second internal gear pump 1 and further depressions for hydraulic structural elements of the slip control means. Structural elements of this type are solenoid valves and hydraulic accumulators (not shown). The abovementioned electric motor (not illustrated) is flange-connected to the outside of the hydraulic block 15 , on the motor shaft of which electric motor or on a gear mechanism shaft of a gear mechanism which is flange-connected to the electric motor the driving gear 8 is seated which drives the two internal gear pumps 1 via the drive gears 7 . The seats for the hydraulic structural elements are connected to one another by way of bores in the hydraulic block 15 , as a result of which the hydraulic structural elements (not shown) of the slip control means are connected to one another hydraulically. Fitted with the hydraulic structural elements and provided with the electric motor and further electric, electromechanical and electronic components, the hydraulic block 15 forms a hydraulic assembly and a slip control assembly of the hydraulic vehicle brake system.
[0028] A pump inlet which is arranged offset at an angle with respect to the pump outlet 29 can be brought about, like the pump outlet 29 , through the cover 4 and the axial washer 19 or, on the bottom of the depression in the hydraulic block 13 which forms the installation space 28 , through a through hole in the thrust washer 26 . The pump inlet is situated outside the sectional plane and therefore cannot be seen.
[0029] The pressure field seal 21 is a sealing ring which encloses the semi-crescent-shaped pressure field 20 with a step-shaped annular cross section. An annular end face of the pressure field seal 21 bears against the outer side of the axial washer 19 . Offset to the outside and in the direction of the cover 4 with respect thereto, the pressure field seal 21 has a sealing bead which bears against the bottom of the pressure field 20 in the cover 4 . In an annular step on the outside of the pressure field seal 21 and facing the axial washer 19 , a supporting ring 30 encloses the pressure field seal 21 and supports the pressure field seal 21 from the outside.
[0030] A filter 31 is arranged in the pressure field 20 inside the pressure field seal 21 . The filter 31 , for example a filter fabric, is encapsulated on its edge by a flange-like frame 32 which is semi-crescent-shaped in a manner which corresponds to the pressure field 20 and/or an inner side of the pressure field seal 21 . A clearance within the frame 32 , in which the filter 31 is situated, is likewise semi-crescent-shaped, in order to ensure a large filter area. The flange-shaped frame 32 of the filter 31 is smaller than an internal circumference of the pressure field seal 21 , with the result that there is a gap 33 (see FIG. 2 ) on the circumference between the frame 32 of the filter 31 and the pressure field seal 21 . The flange-like frame 32 of the filter 31 is flatter than the depth of the pressure field 20 , with the result that there is a gap 34 between a side of the frame 32 of the filter 31 , which side faces the axial washer 19 , and the axial washer 19 . The pressure field 20 communicates with the pressure space of the pump space 13 of the internal gear pump 1 through the through hole 22 in the axial washer 19 and the gaps 33 , 34 between the frame 32 of the filter 31 and the axial washer 19 and the pressure field seal 21 . By way of the pressure loading, the pressure field seal 21 is loaded into sealing contact both with the axial washer 19 and with the circumference and/or the bottom of the pressure field 20 in the cover 4 . The gap 33 between the frame 32 of the filter 31 and the axial washer 19 is part of the pressure field 20 .
[0031] The frame 32 of the filter 31 has a collar 35 which protrudes toward the bottom of the pressure field 20 and bears with an outwardly protruding sealing bead in a sealing manner against a mating collar 14 of the cover 4 in the pressure field 20 , which mating collar 14 encloses the collar 35 . The collar 35 of the frame 32 of the filter 31 encloses the clearance in the frame 32 , in which the filter 31 is arranged.
[0032] The frame 32 of the filter 31 forms a supporting element which supports the pressure field seal 21 from the inside. If the hydraulic block 15 is evacuated by way of the internal gear pump 1 before filling of the vehicle brake system with brake fluid, the frame 32 of the filter 31 which forms the supporting element prevents the pressure field seal 21 being displaced into the pressure field 20 to the inside and holds the pressure field seal 21 in its provided position on the circumference of the pressure field 20 .
[0033] Within the collar 35 , a through hole 36 opens into the bottom of the pressure field 20 . The through hole 36 penetrates the cover 4 of the internal gear pump 1 in an axially parallel manner. As viewed from the pressure field 20 , the through hole 36 first of all widens conically with the formation of a valve seat 37 and subsequently by way of two annular steps. A non-return valve 38 is arranged in the through hole 36 , which non-return valve 38 has a disk-shaped valve body 39 with a ball ring-shaped bearing face 40 which interacts with the valve seat 37 , and a valve stem 41 .
[0034] The valve stem 41 protrudes into a tubular damper body 42 which has a transverse wall 43 with a hole in its interior, through which hole the valve stem 41 reaches. The hole in the transverse wall 43 of the damper body 42 is larger than the valve stem 41 , with the result that there is a passage.
[0035] On a side which faces away from the pressure field 20 , the stepped through hole 36 in the cover 6 is closed in a pressure-tight manner by way of a cap 44 . The cap 44 is pressed into the through hole 36 and is held in a pressure-tight manner, for example, by way of a calked connection (not shown). The cap 44 bears against an annular step of the through hole 36 . The damper body 42 is movable in the through hole 36 ; a spring element 45 in the form of a compression coil spring which is arranged between the cap 44 and the transverse wall 43 of the damper body 42 loads the damper body 42 and, via the latter, the closing body 39 of the non-return valve 38 against the valve seat 37 . On account of its movability in the through hole 36 , the damper body 42 damps pressure oscillations of brake fluid which occur during operation of the internal gear pump 1 as a result of the non-return valve 38 .
[0036] The closing body 39 of the non-return valve 38 and of one end of the damper body 42 which faces it are enclosed by an annular channel 46 which is configured as an undercut in the through hole 36 adjacently to the valve seat 37 . The pump outlet 29 which runs radially in the cover 4 opens into the annular channel 46 . The pump outlet 29 is offset axially with respect to the annular channel 46 , with the result that the pump outlet 29 intersects the annular channel 46 . This results in a step with a small through flow cross section, which step likewise damps pressure oscillations in the pump outlet.
[0037] The through hole 22 in the axial washer 19 , which through hole 22 communicates with the pressure space in the pump space 13 of the internal gear pump 1 , the pressure field 20 , the clearance in the frame 32 of the filter 31 , the through hole 36 as far as the damper body 42 , the annular channel 46 which encloses the closing body 39 of the non-return valve 38 , the annular groove 23 in the hydraulic block 15 , which annular groove 23 encloses the cover 4 between the sealing rings 25 and into which annular groove 23 the radial part of the pump outlet 29 opens, and the outlet bore 24 in the hydraulic block 15 , which outlet bore 24 intersects the annular groove 23 , form the pump outlet. | An internal gear pump comprises an internal gear, a pinion eccentrically positioned in the internal gear and configured to mesh with the internal gear, a cover configured to close an installation space of the internal gear pump, and positioned on end sides of the pinion and the internal gear, a pump outlet leading through the cover, and a non-return valve positioned in the pump outlet in the cover and configured to open to allow flow out of the internal gear pump, and further configured to shut to disallow a return flow through the pump outlet into the internal gear pump. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application, is a Continuation of U.S. patent application Ser. No. 12/381,871, filed Mar. 17, 2009, has been issued an allowance, international application has been filed on Jul. 20, 2009 with No. PCT/US2009/004183, claims priority, entitled: Solar Powered DC Load System.
BACKGROUND OF THE INVENTION
[0002] This invention uses solar energy to power a direct current (DC) load system as well as using rechargeable batteries to store the power that can be generated by solar energy to support a DC load. More particularly this invention not only protects the rechargeable battery from over discharge and also targets various needs of the user to create several combination systems including: a water pump combined with an illuminating system, a water pumping system, and an illumination system that includes at least one LED. These combination systems can synchronize the day and night cycles to turn on and off automatically.
[0003] The prior art showed some control circuits or apparatus that used solar energy to power a water pump system, or lighting system or battery protection control system. The US patent to U.S. Pat. No. 5,569,998, filed Oct. 29, 1996, by Thomas Cowan, indicated that the apparatus controlled a water pumping system with complex control circuits and a high number of components such as voltage reference generator, voltage interpreter, charge current simulator, voltage comparator, and complex charge switch driver ext. This apparatus only can be used for home and the prior art only controls a water pumping system without an illuminating system.
[0004] From the US Patent Application Publication number 2008/0185988 A1, filed Feb. 7, 2007, by Chen-Yueh Fan, the control circuit shows that solar garden light device needs an external DC power source which creates additional installation work for the users to support this garden lights. One of embodiments of the present invention has an illumination system which includes at least one LED without the external DC power source. The present invention also shows different circuits and components over the prior art. The present invention can combine the illumination system with the water pumping system.
[0005] The current invention has dramatic advantages which are more powerful functionalities and wider range of usage with reliable control circuits that can be put in one apparatus with varied functionality that target different working hours based on daily and seasonal cycles and different need of users.
BRIEF DESCRIPTION OF THE DRAWING
[0006] FIG. 1 is a block diagram of (a) a battery discharge control circuit and (b) a battery output circuit for DC load.
[0007] FIG. 2 is a block diagram of (a) a control circuit for night time DC load, (b) an output circuit for night time DC load, and (c) a charging battery circuit;
[0008] FIG. 3 is a block diagram of (a) a control circuit for day time DC load, (b) a combined an output circuit for day time DC load to a battery charging circuit;
[0009] FIG. 4 is a combination block diagram of (a) a battery discharge control circuit, (b) a control circuit for night time DC load, (c) a combined battery output circuit for DC load to a charging battery circuit, (d) a combined a battery output circuit for DC load to an output circuit for night time DC load;
[0010] FIG. 4 a with a switch and group 2 LED in addition to the FIG. 4 ;
[0011] FIG. 5 is a combination block diagram of (a) a battery discharge control circuit, (b) a control circuit for day time DC load, (c) a combined a battery output circuit for DC load to an output circuit for day time DC load and a charging battery circuit;
[0012] FIG. 5 a with a switch in addition to FIG. 5 ;
[0013] FIG. 6 is a combination block diagram of (a) a battery discharge control circuit, (b) a control circuit for night time DC load, (c) a combined a battery output circuit for DC load to an output circuit for night time DC load, and (d) a charging battery circuit.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The Figures of drawing are for the purpose of illustration and operation of varied embodiments; the symbolized characters or alternative replacement characters denoting similar elements in the Figures are not limited scope of the invention. Certain changes may be made in the foregoing disclosure without departing from the scope of the invention.
[0015] According to FIG. 1 of the invention, the present embodiment shows there is a need to protect the rechargeable battery and it is critical to avoid the rechargeable battery from over discharge.
[0016] One of the circuits involved in the present embodiment is a battery discharge control circuit. This circuit comprises a preset voltage which is determined by a number of components: at least one diode ( 14 -F 1 , 18 -F 1 ), a zener diode 16 -F 1 or a replacement of the zener diode 16 -Fa 1 , an input of a normally open (N.O.) solid state relay 32 -F 1 or a normally open (N.O.) device 32 -Fa 1 . A nominal voltage is nominated by at least one rechargeable battery source 42 -F 1 for the DC load system. The components within the preset voltage are connected in series to each other then coupled in parallel to the rechargeable battery source 42 -F 1 . The preset voltage is approximately equal to or greater than the nominal voltage of the rechargeable battery source, when an input voltage drops out of the low end control range of the input of the N.O. solid state relay 32 -F 1 or normally open (N.O.) device 32 -Fa 1 and reaches the preset voltage level, an output of the N.O. solid state relay 32 -F 1 or the N.O. device 32 -Fa 1 opens up and disconnects at least one type of DC load 36 -F 1 that includes but not limited to a type of motor operation having at least a water pump and/or a type of at least one light emitting diode/LED to access the rechargeable battery source 42 -F 1 . The preset voltage is the lowest level that the rechargeable battery source can discharge. The rechargeable battery source includes a rechargeable battery or a rechargeable battery pack.
[0017] The second circuit shown in FIG. 1 of the present embodiment is a battery output circuit for DC load. The circuit comprises at least one rechargeable battery source 42 -F 1 that is the same power storage source in the battery discharge control circuit and is connected in parallel to a diode 26 -F 1 and the output of the N.O. solid state relay 32 -F 1 or the N.O. device 32 -Fa 1 that is the same solid state relay or the N.O. device in the battery discharge control circuit, at least one type of the DC load 36 -F 1 which includes but not limited to a type of motor operation having at least a water pump and a type of at least one LED directly or indirectly connected in series to a negative pole of the output of the N.O. solid state relay 32 -F 1 or the N.O. device 32 -Fa 1 . Additional rechargeable battery sources 42 -F 1 can increase the capacity of the power for the system. The circuits in this embodiment are reliable and have an ability to combine with additional circuits and components which make the system more useful.
[0018] The battery discharge control circuit and the battery output circuit for DC load can combine with additional circuit(s) and component(s) including circuits from the FIG. 2 and FIG. 3 to create a combination system.
[0019] Referring to the FIG. 2 of the invention, the first circuit is a control circuit for night time DC load comprises a predetermined voltage that is determined by an input of a normally closed (N.C.) solid state relay 34 -F 2 or an input of a normally closed (N.C.) device 34 -Fa 2 connected in series to at least one diode ( 20 -F 2 , 24 -F 2 ); a zener diode 22 -F 2 or a replacement of the zener diode 22 -Fa 2 may be connected to the input of the N.C. solid state relay 34 -F 2 or the N.C. device 34 -Fa 2 in series for adjusting the predetermined voltage up to the voltage of at least one system solar panel ( 40 -F 2 , 41 -F 2 ), or alternatively using a small solar panel 44 -F 2 instead of the system solar panel 40 -F 2 without the diodes. The components within the predetermined voltage ( 20 -F 2 , 22 -F 2 or 22 -Fa 2 , 24 -F 2 and 34 -F 2 or 34 -Fa 2 input N.C.) are connected to each other in series then connected in parallel to the system solar panels ( 40 -F 2 , 41 -F 2 ) which is synchronizing the day and night cycles for the night time DC load.
[0020] Synchronizing the day and night cycles for the night time DC load means that when at least one system solar panel ( 40 -F 2 , 41 -F 2 ) connected in parallel to the input of the normally closed (N.C.) solid state relay 34 -F 2 or the normally closed (N.C.) device 34 -Fa 2 and it may connect to the diodes ( 20 -F 2 , 22 -F 2 or 22 -Fa 2 , 24 -F 2 ) or using the small solar panel ( 44 -F 2 ) to replace the system solar panel 40 -F 2 without the diodes, the input of the N.C. solid state relay 34 -F 2 or the N.C. device 34 -Fa 2 prevents the system solar panels ( 40 -F 2 , 41 -F 2 ) and the rechargeable battery source 42 -F 2 to access at least one type of the DC load 36 -F 2 which includes but not limited to a type of motor operation having at least a water pump and/or a type of at least one light emitting diode/LED in the early morning through the day, but connected the rechargeable battery source 42 -F 2 to the DC load 36 -F 2 at evening through the night, therefore an output of the N.C. solid state relay or the N.C. device 34 -F 2 opens up (is turned on) in the early morning through the day time, the DC load 36 -F 2 cannot receive power to operate, but the output of the N.C. solid state relay 34 -F 2 or the N.C. device 34 -Fa 2 is closed at evening through the night, the DC load 36 -F 2 can receive power to operate.
[0021] The second circuit for FIG. 2 of the embodiment is an output circuit for night time DC load which comprises at least one rechargeable battery source 42 -F 2 that can use the same components used in the battery discharge control circuit and the battery output circuit for DC load and is connected in parallel to a diode 30 -F 2 , an output of the N.C. solid state relay 34 -F 2 or the N.C. device 34 -Fa 2 that is the same solid state relay or the N.C. device in the control circuit for night time DC load, at least one type of the DC load 36 -F 2 which can be the same DC load in the battery output circuit and it connected in series to a negative pole of the output of the N.C. solid state relay or the N.C. device 34 -F 2 .
[0022] During the day, the night time DC load 36 -F 2 has no output, but there is a charging battery circuit which includes at least one system solar panel 40 -F 2 charging at least one rechargeable battery source 42 -F 2 through an anti-reverse power diode 12 -F 2 for DC load 36 -F 2 that is used at night. The embodiment can have more than one system solar panel ( 40 -F 2 , 41 -F 2 ) to increase the output power. The output voltage of the system solar panel 41 -F 2 can be the same value with the system solar panel 40 -F 2 , but the output of current can be the same or different.
[0023] The control circuit for night time DC load, the output circuit for night time DC load and the charging battery circuit in FIG. 2 can combine with additional circuit(s) and component(s) including circuits from the FIG. 1 and FIG. 3 to create a combination system which makes the system more powerful, widens the usage to satisfy users need.
[0024] According to FIG. 3 of the invention, this embodiment involves several circuits. The first one is a control circuit for day time DC load 36 -F 3 which comprises a predetermined voltage that is determined by an input of a normally open (N.O.) solid state relay 34 -F 3 or an input of a normally open (N.O.) device 34 -Fa 3 connected in series to at least one diode ( 20 -F 3 24 -F 3 ); a zener diode 22 -F 3 or replacement of the zener diode 22 -Fa 3 may be connected to the input of the N.O. solid state relay 34 -F 3 or the input of the N.O. device 34 -Fa 3 in series for adjusting the predetermined voltage up to a voltage of at least one system solar panel ( 40 -F 3 , 41 -F 3 ) or alternatively uses a small solar panel 44 -F 3 instead of the system solar panel 40 -F 3 without the diodes; the components ( 20 -F 3 , 24 -F 3 , 22 -F 3 or 22 -Fa 3 , 34 -F 3 or 34 -Fa 3 N.O. input) within the predetermined voltage are connected in series to each other then connected in parallel to the system solar panel 40 -F 3 which is synchronizing the day and night cycles for day time DC load.
[0025] Synchronizing the day and night cycles for day time DC load means that when at least one system solar panel ( 40 -F 3 , 41 -F 3 ) connected in parallel to the input of the N.O. solid state relay 34 -F 3 or the input of the normally open (N.O.) device 34 -Fa 3 and may connect to the diodes ( 20 -F 3 , 22 -F 3 or 22 -Fa 3 , 24 -F 3 ), or using the small solar panel 44 -F 3 to replace the system solar panel 40 -F 3 without the diodes, the input of the N.O. solid state relay 34 -F 3 or the N.O. device 34 -Fa 3 prevents the rechargeable battery source 42 -F 3 to access at least one type of the DC load 36 -F 3 which includes but not limited to a type of motor operation having at least a water pump and/or a type of at least one LED at evening through the night but is connected to the system solar panel 40 -F 3 and the rechargeable battery source 42 -F 3 to the DC load 36 -F 3 in the early morning through the day, therefore an output of the N.O. solid state relay 34 -F 3 or the N.O. device 34 -Fa 3 is closed (turned on) in the early morning through the day time, the DC load 36 -F 3 can receive power to operate; the output of the N.O. solid state relay 34 -F 3 or the N.O. device 34 -Fa 3 is opened at evening through the night, the DC load 36 -F 3 cannot receive power to operate.
[0026] The second circuit for FIG. 3 of the embodiment is a combined an output circuit for day time DC load to a battery charging circuit which comprises at least one rechargeable battery source 42 -F 3 that can be the same component used in the battery discharge control circuit and it connected in parallel to a diode 30 -F 3 and an output of the N.O. solid state relay 34 -F 3 or the N.O. device 34 -Fa 3 that is the same N.O. solid state relay or the N.O. device in the control circuit for day time DC load, at least one type of the DC load 36 -F 3 which includes but not limited to a type of motor operation having at least a water pump and/or a type of at least one LED connected to a negative pole of the output of the N.O. solid state relay 34 -F 3 or the output of the N.O. device 34 -Fa 3 , at least one system solar panel ( 40 -F 3 , 41 -F 3 ) connected in parallel to two diodes ( 12 -F 3 , 30 -F 3 ) and the output of the N.O. solid state relay 34 -F 3 or the N.O. device 34 -Fa 3 and the DC load 36 -F 3 ; during the day, the system solar panel ( 40 -F 3 , 41 -F 3 ) charges at least one rechargeable battery source 42 -F 3 through an anti-reverse power diode 12 -F 3 while powering the DC load 36 -F 3 through the diodes ( 12 - 3 , 30 -F 3 ) and the output of the N.O. solid state relay 34 -F 3 or the N.O. device 34 -Fa 3 . The DC load 36 -F 3 may receive a partial or full or non power from the system solar panel 40 -F 3 or rechargeable battery source 42 -F 3 which depends upon the system solar panel output power and rechargeable battery source capacity and sun light conditions. The output voltage of the system solar panel 41 -F 3 can be the same value with the system solar panel 40 -F 3 , but the output of current can be the same or different.
[0027] The control circuit for day time DC load and the combined the output circuit for day time DC load to the battery charging circuit in FIG. 3 can incorporate with additional circuits and components including circuits from FIG. 1 and FIG. 2 which makes the system more powerful and widens the usage to satisfy users need.
[0028] Referring to FIG. 4 and FIG. 4 a of the invention, the system selected the FIG. 1 and FIG. 2 to create a combination embodiment. The current embodiment shows a water pumping system combined with an illumination system which is more powerful and widens the usage to satisfy user needs.
[0029] The first circuit in FIG. 4 and FIG. 4 a is a battery discharge control circuit comprises a preset voltage and this voltage is determined by a number of components: at least one diode ( 14 -F 4 , 18 -F 4 ), a zener diode 16 -F 4 or a replacement of the zener diode 16 -Fa 4 , an input of a normally open (N.O.) solid state relay 32 -F 4 or an input of a normally open (N.O.) device 32 -Fa 4 including positive and negative poles. A nominal voltage is nominated by at least one rechargeable battery source 42 -F 4 . The components within the preset voltage ( 14 -F 4 , 16 -F 4 or 16 -Fa 4 , 18 -F 4 ) are connected to each other in series then coupled to the rechargeable battery source 42 -F 4 in parallel. The preset voltage is approximately equal to or greater than the nominal voltage of the rechargeable battery source 42 -F 4 , when an input voltage drops out of the low end control range of the input of the N.O. solid state relay 32 -F 4 or the N.O. device 32 -Fa 4 and reaches the preset voltage level, an output of the N.O. solid state relay 32 -F 4 or the N.O. device 32 -Fa 4 opens up and disconnects at least one type of DC load 36 -F 4 that includes but not limited to a type of motor operation having at least a water pump and/or a type of at least one LED/light emitting diode to access the rechargeable battery source 42 -F 4 . The preset voltage is the lowest level that the rechargeable battery source 42 -F 4 can discharge; the rechargeable battery source 42 -F 4 includes a rechargeable battery or a rechargeable battery pack.
[0030] The second circuit in FIG. 4 and FIG. 4 a is a control circuit for night time DC load comprises a predetermined voltage that is determined by an input of a normally closed (N.C.) solid state relay 34 -F 4 or an input of a normally closed (N.C.) device 34 -Fa 4 connected in series to at least one diode ( 20 -F 4 , 24 -F 4 ); a zener diode 22 -F 4 or an replacement of the zener diode 22 -Fa 4 may be connected to the input of the N.C. solid state relay 34 -F 4 or the N.C. device 34 -Fa 4 in series for adjusting the predetermined voltage up to a voltage of at least one system solar panel ( 40 -F 4 , 41 -F 4 ); or using a small solar panel 44 -F 4 instead of the system solar panel 40 -F 4 without the diodes; the components within the predetermined voltage ( 20 -F 4 , 22 -F 4 or 22 -Fa 4 , 24 -F 4 and 34 -F 4 or 34 -Fa 4 N.C. input) are connected to each other in series then connected in parallel to the system solar panels ( 40 -F 4 , 41 -F 4 ) which is synchronizing the day and night cycles for night time DC load.
[0031] Synchronizing the day and night cycles for night time DC load means that when at least one system solar panel ( 40 -F 4 , 41 -F 4 ) connected in parallel to the input of the N.C. solid state relay 34 -F 4 or the input of the N.C. device 34 -Fa 4 and may connect to the diodes ( 20 -F 4 , 22 -F 4 or 22 -Fa 4 , 24 -F 4 ) or using the small solar panel to replace the system solar panel 44 -F 4 without the diodes, the input of the N.C. solid state relay 34 -F 4 or the N.C. device 34 -Fa 4 prevents the system solar panel 40 -F 4 and the rechargeable battery source 42 -F 4 to access at least one type of DC load that includes but not limited to a type of at least one LED/light emitting diode (LED 1 -F 4 , LED 2 -F 4 , LEDn-F 4 ) for the embodiment of the FIG. 4 , and group 1 LED and a group 2 LED for the embodiment of the FIG. 4 a in the early morning through the day, but connected the rechargeable battery source 42 -F 4 to the DC load of at least one LED (LED 1 -F 4 , LED 2 -F 4 , LEDn-F 4 ), the group 1 LED and the group 2 LED at evening through the night, the output of the N.C. solid state relay 34 -F 4 or the output of the N.C. device 34 -Fa 4 is opened in the early morning through the day time, the DC load of at least one LED (LED 1 -F 4 , LED 2 -F 4 , LEDn-F 4 ), the group 1 LED and the group 2 LED cannot receive power; an output of the N.C. solid state relay 34 -F 4 or the N.C. device 34 -Fa 4 is closed at evening through the night time, the DC load of the at least one LED (LED 1 -F 4 , LED 2 -F 4 , LEDn-F 4 ), the group 1 LED, and the group 2 LED can receive power to illuminate.
[0032] The third circuit is a combined the battery output circuit for DC load to a charging battery circuit comprises at least one rechargeable battery source 42 -F 4 that is the same storage source in the battery discharge control circuit and is connected in parallel to a diode 26 -F 4 and an output of the Normally Open (N.O.) solid state relay 32 -F 4 or an output of the normally open (N.O.) device 32 -Fa 4 that is the same solid state relay or the device in the battery discharge control circuit, the DC load water pump 36 -F 4 directly or indirectly connected in series to a negative pole of the output of the N.O. solid state relay 32 -F 4 or the N.O. device 32 -Fa 4 through a double pole double throw 38 -F 4 for FIG. 4 a or without a double pole double throw 38 -F 4 for FIG. 4 ; during the day, at least one system solar panel ( 40 -F 4 , 41 -F 4 ) charges at least one rechargeable battery source 42 -F 4 through a diode 12 -F 4 which is for anti-reverse power purpose while powers the water pump 36 -F 4 through the diode 26 -F 4 and the output of the N.O. solid state relay 32 -F 4 or the N.O. device 32 -Fa 4 if sun light is intense enough. The water pump 36 -F 4 may receive a partial or full or non power from the system solar panel 40 -F 4 or rechargeable battery source 42 -F 4 which depends upon the system solar panels ( 40 -F 4 , 41 -F 4 ) output power and rechargeable battery source 42 -F 4 capacity and sun light conditions.
[0033] The fourth circuit is a combined the battery output circuit for DC load to an output circuit for night time DC load comprises at least one rechargeable battery source 42 -F 4 which is the same component in the battery discharge control circuit and is connected in parallel to the diode 26 -F 4 , the output of the N.O. solid state relay 32 -F 4 or the N.O. device 32 -Fa 4 that is the same N.O. solid state relay or the N.O. device in the battery discharge control circuit, an output of the N.C. solid state relay 34 -F 4 or the N.C. device 34 -Fa 4 that is the same solid state relay or the N.C. device in the control circuit for night time DC load and is connected in series to a negative pole of the output of the N.O. solid state relay 32 -F 4 or the device 32 -Fa 4 through a diode 30 -F 4 , the at least one type of DC load that includes but not limited to a type of at least one LED (LED 1 -F 4 , LED 2 -F 4 , LEDn-F 4 ) connected to a negative pole of the output of the solid state relay 34 -F 4 or the N.C. device 34 -Fa 4 for the FIG. 4 ; a group 1 LED and a group 2 LED connected to the negative pole of the output of the N.C. solid state relay 34 -F 4 or the N.C. device 34 -Fa 4 for FIG. 4 a.
[0034] The embodiment in the FIG. 4 is for a warm climate area, the water is not frozen all year, so the water pump 36 -F 4 does not have to shut down. But in some areas during the winter or when the water is frozen the water pump 36 -F 4 a cannot pump the water, the embodiment in the FIG. 4 a allows the DC load 36 -F 4 to shut down when needed. A double pole double throw (DPDT) switch 38 -F 4 or an equivalent component performs similar functions like the DPDT switch may employ to perform those features. The DPDT switch 38 -F 4 can disconnect the DC load water pump 36 -F 4 to access the rechargeable battery source 42 -F 4 and the system solar panel 40 -F 4 through the diodes ( 12 -F 4 , 26 -F 4 ) and the output of the N.O. solid state relay 32 -F 4 or the N.O. device 32 -Fa 4 while it can simultaneously connect the group 2 LED which includes at least one LED to the rechargeable battery source through the diode 26 -F 4 , the output of the N.O. solid state relay 32 -F 4 or the N.O. device 32 -Fa 4 , the diode 30 -F 4 and the output of the N.C. solid state relay 34 -F 4 or the N.C. device 34 -Fa 4 , or non-connected to either the water pump 36 -F 4 nor the DC load group 2 LED; the group 2 LED is for balancing the power usage when the rechargeable battery source 42 -F 4 does not powering the DC load water pump 36 -F 4 .
[0035] The FIG. 5 and FIG. 5 a of the invention show selections from FIG. 1 and FIG. 3 to create a combination of the DC load water pumping system which works during the day and shuts off at night automatically, the combination system is an another example for widening the usage and satisfying different users need.
[0036] The first circuit in FIG. 5 and FIG. 5 a is a battery discharge control circuit comprises a preset voltage which is determined by: at least one diode ( 14 -F 5 , 18 -F 5 ), a zener diode 16 -F 5 or a replacement of the zener diode 16 -Fa 5 , an input of a normally open (N.O.) solid state relay 32 -F 5 or an input of a normally open (N.O.) device 32 -Fa 5 . A nominal voltage is nominated by at least one rechargeable battery source 42 -F 5 . The components within the preset voltage are connected to each other in series then coupled to the rechargeable battery source 42 -F 5 in parallel. The preset voltage is approximately equal to or greater than the nominal voltage of the rechargeable battery source 42 -F 5 . When the input voltage drops out of the low end control range of the input of the N.O. solid state relay 32 -F 5 or the N.O. device 32 -Fa 5 and reaches the preset voltage level, an output of the N.O. solid state relay 32 -F 5 or the N.O. device 32 -Fa 5 opens up and disconnects at least one type of DC load 36 -F 5 that includes but not limited to a type of motor operation having at least a water pump and/or a type of at least one LED/light emitting diode to access the rechargeable battery source 42 -F 5 . The preset voltage is the lowest level that the rechargeable battery source 42 -F 5 can discharge. The rechargeable battery source 42 -F 5 includes a rechargeable battery or a rechargeable battery pack.
[0037] The second circuit in FIG. 5 and FIG. 5 a is a control circuit for day time DC load comprises a predetermined voltage that is determined by an input of a normally open (N.O.) solid state relay 34 -F 5 or an input of a normally open (N.O.) device 34 -Fa 5 connected in series to at least one diode ( 20 -F 5 , 24 -F 5 ); a zener diode 22 -F 5 or a replacement of the zener diode 22 -Fa 5 may be connected to the input of the N.O. solid state relay 34 -F 5 or the N.O. device 34 -Fa 5 in series for adjusting the predetermined voltage up to the voltage of at least one system solar panel ( 40 -F 5 , 41 -F 5 ); or alternatively using a small solar panel 44 -F 5 instead of the system solar panel 40 -F 5 without the diodes. The components within the predetermined voltage ( 20 -F 5 , 22 -F 5 or 22 -Fa 5 , 24 -F 5 and 34 -F 5 or 34 -Fa 5 N.O. input) are connected in series to each other then connected in parallel to the system solar panels ( 40 -F 5 , 41 -F 5 ) which is synchronizing the day and night cycles for day time DC load.
[0038] Synchronizing the day and night cycles for day time DC load means that when at least one system solar panel ( 40 -F 5 , 41 -F 5 ) connected in parallel to the input of the normally open (N.O.) solid state relay 34 -F 5 or the input of the N.O. device 34 -Fa 5 and may connect to the diodes ( 20 -F 5 , 22 -F 5 or 22 -Fa 5 and 24 -F 5 ), or using the small solar panel 44 -F 5 to replace the system solar panel ( 40 -F 5 , 41 -F 5 ) without the diodes, the input of the N.O. solid state relay 34 -F 5 or the N.O. device 34 -Fa 5 prevents the system solar panel and the rechargeable battery source 42 -F 5 to access at least one type of DC load 36 -F 5 that includes but not limited to a type of motor operation having at least a water pump at the evening and through the night but connected the system solar panel 40 -F 5 and rechargeable battery source 42 -F 5 to the water pump 36 -F 5 in the early morning through the day, therefore an output of the N.O. solid state relay 34 -F 5 or the N.O. device 34 -Fa 5 is closed (turned on) in the early morning through the day time, the at least one type of DC load 36 -F 5 can receive power to operate, the output of the N.O. solid state relay 34 -F 5 or the N.O. device 34 -Fa 5 is opened at evening through the night, the at least one type of DC load 36 -F 5 cannot receive power to operate;
[0039] The third circuit in FIG. 5 and FIG. 5 a is a combined a battery output circuit to an output circuit for day time DC load and the charging battery circuit comprises at least one rechargeable battery source 42 -F 5 that is the same power storage source in the battery discharge control circuit and it connected in parallel to a diode 26 -F 5 and an output of the Normally Open (N.O.) solid state relay 32 -F 5 or the N.O. device 32 -Fa 5 that is the same N.O. solid state relay or the N.O. device in the battery discharge control circuit, the output of the N.O. solid state relay 34 -F 5 or the N.O. device 34 -Fa 5 that is the same N.O. solid state relay or the N.O. device in the control circuit for day time DC load and is connected in series to a negative pole of the output of the N.O. solid state relay 32 -F 5 or the N.O. device 32 -Fa 5 through a diode 30 -F 5 , the DC load 36 -F 5 which includes but not limited to a type of motor operation having at least a water pump connected in series to a negative pole of the output of the N.O. solid state relay 34 -F 5 or the N.O. device 34 -Fa 5 which is the same solid state relay or the device used in the control circuit for day time DC load; the reversed order of connection between the output of the N.O. solid state relay 34 -F 5 or the N.O. device 34 -Fa 5 and the output of the Normally Open (N.O.) solid state relay 32 -F 5 or the N.O. device 32 -Fa 5 also works fine in the combined a battery output circuit to an output circuit for day time DC load and the charging battery circuit; during the day if sun light is intensity enough, at least one system solar panel ( 40 -F 5 , 41 -F 5 ) charges at least one rechargeable battery source 42 -F 5 through a switch 10 -F 5 and a diode 12 -F 5 for FIG. 5 a or through the diode 12 -F 5 for FIG. 5 while powers the water pump 36 -F 5 through a diode 26 -F 5 , the output of the N.O. solid state relay 32 -F 5 or the N.O. device 32 -Fa 5 , the diode 30 -F 5 and the output of the N.O. solid state relay 34 -F 5 or the N.O. device 34 -Fa 5 . The water pump 36 -F 5 may receive a partial or full or non power from the system solar panel 40 -F 5 or rechargeable battery source 42 -F 5 which depends upon the system solar panel output power and the rechargeable battery source 42 -F 5 capacity and sun light conditions; the single pole single throw switch 10 -F 5 may employ to control the system solar panels ( 40 -F 5 , 41 -F 5 ) to access all the circuits including all of the components when the weather not allowed the water pump 36 -F 5 to pump the water; the diode 12 -F 5 is for anti-reverse power purpose.
[0040] The FIG. 6 of the invention selected FIG. 1 and FIG. 2 to create a combination embodiment for night time DC load system which includes an illumination system, a water pumping system or the illuminating system combines with a water pumping system, the night time DC load turned off in the morning through the day and turns on at evening through the night automatically; these are examples of widening the usage and satisfying different users needs.
[0041] The first circuit in FIG. 6 is a battery discharge control circuit comprises a preset voltage which is determined by a number of components: at least one diode ( 14 -F 6 , 18 -F 6 ), a zener diode 16 -F 6 or a replacement of the zener diode 16 -Fa 6 , an input of a normally open (N.O.) solid state relay 32 -F 6 or a normally open (N.O.) device 32 -Fa 6 . A nominal voltage is nominated by at least one rechargeable battery source 42 -F 6 . The components within the predetermined voltage are connected to each other in series ( 14 -F 6 , 16 -F 6 or 16 -Fa 6 , 18 -F 6 , 32 -F 6 or 32 -Fa 6 N.O. input) then coupled to at least one rechargeable battery source 42 -F 6 in parallel. The preset voltage is approximately equal to or greater than the nominal voltage of the rechargeable battery source, when the input voltage drops out of the low end control range of the input of the N.O. solid state relay 32 -F 6 or the N.O. device 32 -Fa 6 and reaches the preset voltage level, an output of the N.O. solid state relay 32 -F 6 or the N.O. device 32 -Fa 6 opens up and disconnects at least one type of DC load 36 -F 6 that includes but not limited to a type of motor operation having at least a water pump and/or a type of at least one LED (LED 1 -F 6 , LED 2 -F 6 , LED_n-F 6 ) to access the rechargeable battery source 42 -F 6 . The preset voltage is the lowest level that the rechargeable battery source 42 -F 6 can discharge. The rechargeable battery source 42 -F 6 includes a rechargeable battery or a rechargeable battery pack.
[0042] The second circuit in FIG. 6 is a control circuit for night time DC load includes a predetermined voltage that is determined by an input of normally closed (N.C.) solid state relay 34 -F 6 or an input of a normally closed (N.C.) device 34 -Fa 6 connected in series to at least one diode ( 20 -F 6 , 24 -F 6 ), a zener diode 22 -F 6 or a replacement of the zener diode 22 -Fa 6 may be connected to the input of the N.C. solid state relay 34 -F 6 or the N.C. device 34 -Fa 6 in series for adjusting the predetermined voltage up to the voltage of at least one system solar panel 40 -F 6 , or alternatively using a small solar panel 44 -F 6 instead of the system solar panel 40 -F 6 without the diodes; the components within the predetermined voltage ( 20 -F 6 , 22 -F 6 or 22 -Fa 6 , 24 -F 6 and 34 -F 6 or 34 -Fa 6 N.C. input) are connected in series to each other then connected in parallel to the system solar panel ( 40 -F 6 ) which is synchronizing the day and night cycles for the night time DC load.
[0043] Synchronizing the day and night cycles for night time DC load means when at least one system solar panel ( 40 -F 6 , 41 -F 6 ) connected in parallel to the input of the normally closed (N.C.) solid state relay 34 -F 6 or the input of the normally closed (N.C.) device 34 -Fa 6 and may connected to the diodes ( 20 -F 6 , 22 -F 6 or 22 -Fa 6 , 24 -F 6 ), or using a small solar panel 44 -F 6 to replace the system solar panel 40 -F 6 without the diodes, the input of the N.C. solid state relay 34 -F 6 or the N.C. device 34 -Fa 6 prevents the system solar panel 40 -F 6 and the rechargeable battery source 42 -F 6 to access the at least one type of DC load 36 -F 6 that includes but not limited to a type of motor operation having at least a water pump and/or a type of at least one LED (LED 1 -F 6 , LED 2 -F 6 , LED_n-F 6 ) in the early morning through the day but connected the rechargeable battery source 42 -F 6 to access the DC load 36 -F 6 at evening through the night, therefore an output of the N.C. solid state relay 34 -F 6 or the N.C. device 34 -Fa 6 turned on in the early morning through the day time, the DC load 36 -F 6 cannot receive power, the output of the N.C. solid state relay 34 -F 6 or the N.C. device 34 -Fa 6 is closed at evening through the night time, the DC load 36 -F 6 can receive power for illumination and/or operation.
[0044] The third circuit in FIG. 6 is a combined a battery output circuit to an output circuit for night time DC load comprises at least one rechargeable battery source 42 -F 6 which is the same battery source in the battery discharge control circuit and is connected in parallel to a diode 26 -F 6 and an output of the N.O. solid state relay 32 -F 6 or the normally open (N.O.) device 32 -Fa 6 that is the same N.O. solid state relay or the N.O. device in the battery discharge control circuit, the output of the N.C. solid state relay 34 -F 6 or the N.C. device 34 -Fa 6 that is the same solid state relay or the device in the control circuit for night time DC load and is connected in series to a negative pole of the output of the N.O. solid state relay 32 -F 6 or the output of the device 32 -Fa 6 through a diode 30 -F 6 , the at least one type of DC load 36 -F 6 includes but not limited to a type of motor operation having at least a water pump and/or a type of at least one LED (LED 1 -F 6 , LED 2 -F 6 , LED_n-F 6 ) connected directly or indirectly to a negative pole of the output of the N.C. solid state relay 34 -F 6 or the N.C. device 34 -Fa 6 ; the reversed order of connection between the output of the N.C. solid state relay 34 -F 6 or the N.C. device 34 -Fa 6 and the output of the N.O. solid state relay 32 -F 6 or the normally open (N.O.) device 32 -Fa 6 also works fine for the combined a battery output circuit to an output circuit for night time DC load.
[0045] During the day, there is a charging battery circuit, at least one system solar panel ( 40 -F 6 , 41 -F 6 ) charges at least one rechargeable battery source 42 -F 6 through a diode 12 -F 6 which is used for anti-reversed power.
[0046] The combination system selected circuits and components from FIG. 1 and FIG. 2 to create night time DC load system it turned off in the morning through the day and turns on at evening through the evening automatically, which is another example of widening the usage to satisfy different user needs.
[0047] The normally open (N.O.) device ( 32 -Fa 1 , or 34 -Fa 3 , or 32 -Fa 4 , or 32 -Fa 5 , or 34 -Fa 5 , or 32 -Fa 6 ) is a device that can replace the normally open (N.O.) solid state relay ( 32 -F 1 , or 34 -F 3 , or 32 -F 4 , or 32 -F 5 , or 34 -F 5 , or 32 -F 6 ) respectively which has an input including positive and negative poles (control terminals) and an output including positive and negative poles (first and second terminals), the input current and voltage control the output current and voltage, the normally open (N.O.) device further including a normally open I/O module, or a normally open relay, or a normally open optocoupler (opto-isolator) or the device that performs the similar functions as the normally open device.
[0048] The normally closed (N.C.) device ( 34 -Fa 2 or 34 -Fa 4 or 34 -Fa 6 ) is a device can replace the normally closed (N.C.) solid state relay ( 34 -F 2 or 34 -F 4 or 34 -F 6 ) respectively, which has an input including positive and negative poles (control terminals) and an output including positive and negative poles (first and second terminals), the input current and voltage control the output current and voltage, the N.C. device further including a normally closed I/O module, or a normally closed relay, or a optocoupler (opto-isolator) or the N.C. device that performs the similar functions as the normally closed device.
[0049] The replacement of the zener diode 16 -Fa 1 or 22 -Fa 2 or 22 -Fa 3 or 22 -Fa 4 or 16 -Fa 4 or 16 -Fa 5 or 22 -Fa 5 or 16 -Fa 6 or 22 -Fa 6 can replace the zener diode 16 -F 1 or 22 -F 2 or 22 -F 3 or 22 -F 4 or 16 -F 4 or 16 -F 5 or 22 -F 5 or 16 -F 6 or 22 -F 6 respectively, the replacement of the zener diode further including a light emitting diode, or a resistor, or a component that consumes approximately the same voltage and current as the zener diode.
[0050] The small solar panel 44 -F 2 , or 44 -F 3 , or 44 -F 4 or 44 -F 5 or 44 -F 6 is a small output power solar panel that is only used for controlling the input of the normally closed (N.C.) solid state relay 34 -F 2 , or 34 -F 4 or 34 -F 6 or the input of the normally closed (N.C.) device 34 -Fa 2 , or 34 -Fa 4 or 34 -Fa 6 and the input of the normally open (N.O.) solid state relay 34 -F 3 , or 34 -F 5 or the input of the normally open (N.O.) device 34 -Fa 3 , or 34 -Fa 5 , it has approximately the same effect compared to using the system solar panel 40 -F 2 , 41 -F 2 or 40 -F 3 , 41 -F 3 or 40 -F 4 , 41 -F 4 or 40 -F 5 , 41 -F 5 or 40 -F 6 , 41 -F 6 respectively for synchronizing the day and night cycles. | The solar powered direct current (DC) load system is a reliable, versatile and user friendly system; it uses solar energy and rechargeable battery powering at least one type of DC load which are: a type of motor operation such as water pump and/or a type of at least one LED; the system comprises a battery discharge control circuit and a battery output circuit for DC load (FIG. 1 ), at least one rechargeable battery source ( 42 -F 1 ) which is protected by a preset voltage that limits the lowest discharge level, the circuits in the FIG. 1 are able to combine the circuits in FIG. 2 and FIG. 3 which enable operations of the day time and night time DC load to synchronize the day and night cycles; FIG. 4 is a combination system which incorporates circuits in the FIG. 1 and FIG. 2 to create a water pumping system combined an illumination system which can turn on and off automatically; FIG. 4 a with a switch and additional LEDs in addition to the FIG. 4 ; FIG. 5 is a combination system that incorporates circuits in the FIG. 1 and FIG. 3 to create a water pumping system that works during the day and shuts down at night automatically; FIG. 5 a with a switch in addition to the FIG. 5 ; FIG. 6 is a combination system which incorporates FIG. 1 and FIG. 2 circuits to create an illumination system that has at least one LED which can turn off in the morning and turn on at the evening automatically. | 7 |
FIELD OF THE INVENTION
The present invention relates to an antenna with a pre-applied adhesive for use with a radio frequency identification system and a method for assembling a radio frequency identification system using an antenna with a pre-applied adhesive.
BACKGROUND OF THE ART
Radio frequency identification systems (“RFID”) are frequently utilized in many applications, such as electronic surveillance and inventory tracking. RFID systems typically consist of a data carrier, such as a tag or transponder, and a reader. The tags or transponders are used in various formats, such as disks, smart cards, plastic housings, or in paper-thin tags. The tags consist of a silicon die attached to the contact pads on the antenna. Anisotropic or isotropic conductive pastes, anisotropic conductive films and non-conductive pastes are utilized to attach the antenna to the die. To attach the silicone chip to the antenna, manufacturers frequently utilize semiconductor flip chip technology processes. Via the flip chip process, the radio frequency identification dies are picked and placed onto the antenna after an anisotropic conductive adhesive is applied to the pads. The adhesive is then cured at a high temperature for a short time while pressure is applied on top of the die to ensure electrical connection. Due to a number of variables, the flip chip process often has the drawback of a relatively slow processing speed
In all of the existing processes for assembling RFID systems adhesives are applied in a liquid or film form immediately before the die is attached to the antenna after which the unit is cured via heat or energy radiation. Numerous difficulties are presented by the use of such adhesives. For example, the die are extremely small and usually only a few millimeters square in size. Thus, the distances between the attachment bumps on the die are too small to utilize isotropic conductive paste.
Die straps which allow for high speed reel-to-reel processing of the interconnection between the die and the antenna may be utilized. Such high speed processing is critical to manufacturers in order to produce the extremely large number of tags utilized in various industries. The use of high speed processing poses a number of difficulties for manufacturers. For example, high speed processing limits the type of adhesive application techniques and the type of adhesive that may be utilized. A low viscosity adhesive is required for high speed adhesive deposition. However, a low viscosity adhesive tends to have low green strength. Low green strength may cause the die to short after placement on the antenna pads because of the vibration experienced during high web processing speeds. Further, as adhesive has a limited work life, there will be a limited time during which the adhesive may be applied without a variation in its viscosity. To avoid the variation, manufacturers are required to interrupt the assembly process to insert fresh conductive adhesive, resulting in an inefficient process having downtime. It would be advantageous to provide an RFID antenna that could be readily utilized in a high speed assembly process along with a method for assembling RFID systems at a high speed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of an RFID antenna.
FIG. 2 is a top view of an RFID antenna having adhesive pre-applied to its contact pads.
SUMMARY OF THE INVENTION
The present invention discloses an RFID antenna having adhesive pre-applied to one or more of its contact pads to allow for high speed attachment of the antenna to the RFID die or die strap. Also disclosed is a method for attaching an RFID antenna having pre-applied adhesive to a die or die strap.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
During assembly of RFID systems, RFID antennas are attached to the die or die strap to form an RFID data carrier. In order to facilitate high speed processing of the systems, it is desirable to utilize pre-applied adhesives on the contact pads of the RFID antennas. While the present application discusses antennas having two contact pads, it is possible for the antenna to have more than two contact pads and such embodiments are also within the scope of this invention. Antennas with pre-applied adhesive will simplify the die attach assembly process and reduce the production cost to the RFID manufacturers. Currently, RFID system manufacturers apply the adhesives to the antenna, resulting in additional steps in the assembly process. Through the use of the antennas with pre-applied adhesive of the present invention, the RFID system production time will not be limited by the ability to apply adhesives at a sufficiently high speed. The RFID system manufacturers will not be exposed to liquid adhesives, resulting in reduced waste, cleanup time and maintenance time, along with a reduced risk of exposure of its personnel to hazardous chemicals. Further, the softened or melted pre-applied adhesives of the present invention will possess a higher green strength than the liquid adhesives currently utilized resulting in a reduction of mis-alignments between the die and antenna contact pads before curing of the adhesive. Overall, the use of the pre-applied adhesives on the antenna will result in less processing variability and better interconnect quality.
Various types of adhesives, including liquid paste, with or without solvent, and films may be utilized as a pre-applied adhesive on the antenna. The adhesives may be based on either thermo set or thermoplastic chemistry and should preferably have quick or snap bond capability. Depending upon the desired use, the adhesive may be either electrically conductive or electrically non-conductive. In the case that the adhesive is electrically conductive, it may be either anisotropic or isotropic.
FIG. 1 illustrates a typical RFID antenna 10 . Despite the illustrated configuration of antenna 10 , the antenna may be in virtually any desired shape. Contact pads 11 for attachment of the antenna to the die are located at each end of the antenna. FIG. 2 illustrates antenna 10 having pre-applied adhesive 15 on contact pads 11 . The pre-applied adhesive would, after application, be in the form of a film that would be capable of reverting to a softened state at a sufficiently high temperature and then bonding the die to the antenna if it is a thermally activated film. One the other hand, if the film is pressure sensitive in nature, then the die can be attached to the antenna with pressure.
In the method of pre-applying the adhesive, an antenna having at least two contact pads is first provided. Antennas are typically prepared with wet processes, such as screen printing of conductive inks or solution etching of copper/aluminum foil. Next, an adhesive is deposited on one or more of the contact pads. The adhesive may be applied to the antenna via conventional printing or dispensing techniques at either room temperature or, if necessary, high temperature. The adhesive may be applied as a film or in a form capable of forming a film on the contact pad and may be either conductive or non-conductive. The adhesive may then be B-staged onto the antenna contact pads or B-staged onto release liner prior to placement on the antenna contact pads. Many types of adhesives, including solvent-based adhesives, hot melt adhesives and also adhesives with dual cure mechanisms are suitable as B-stage adhesives. A solvent-based adhesive, for example, is B-staged onto the antenna contact pad by the evaporation of the solvent. A hot melt adhesive, on the other hand, is B-staged onto the antenna contact pad after cooling back to room temperature. In a further embodiment, a pressure sensitive adhesive may be utilized. Finally, an adhesive with multiple cure mechanisms is B-staged by partially curing the adhesive through the primary cure mechanism. The primary cure mechanism may consist of a thermal cure with a low temperature hardener or a UV cure hardener. Regardless of the method used to B-stage the adhesive, this process results in the formation of an adhesive film, at room temperature, on the antenna contact pads. For bonding of the antenna to the die, the antenna with the pre-applied adhesives is first brought into contact with the die or die strap. If a thermally activated film is used, the assembly is then heated to a temperature sufficiently high to facilitate adhesive wetting. Wetting is crucial for proper bonding. During the heating process, the pre-applied adhesive softens and then adheres the die or die strap to the antenna. If the film is pressure sensitive in nature, then heat is not required. The die is then attached to the antenna with pressure.
The pre-applied adhesive provides the numerous benefits to the manufacture and process of RFID antennas. For example, the pre-applied adhesive allows for fast, simplified processing for tag assemblers. Further, the pre-applied adhesive eliminates the capital expense required for tag assembly companies to apply the adhesive necessary for the attachment of the die or die strap.
Many modifications and variations of this invention can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. The specific embodiments described herein are offered by way of example only, and the invention is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. | A radio frequency identification (“RFID”) system antenna having adhesive pre-applied to one or more of its contact pads to allow for high speed attachment of the antenna to the RFID die or die strap. Also disclosed is a method for attaching an RFID antenna having pre-applied adhesive to a die or die strap. | 8 |
BACKGROUND
[0001] Computing systems may be cooled using various techniques, such as air cooling and water cooling. Water cooling systems may use hoses and fittings, based on manual installation and removal of clamps and other equipment to ensure proper retention and seal.
BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES
[0002] FIG. 1 is a block diagram of a system including a dripless connector according to an example.
[0003] FIG. 2A is a block diagram of a system including a dripless connector in a first position according to an example.
[0004] FIG. 2B is a block diagram of a system including a dripless connector in a second position according to an example.
[0005] FIG. 3A is a side view of a system including a dripless connector according to an example.
[0006] FIG. 3B is a front view of a system including a dripless connector according to an example.
[0007] FIG. 4A is a perspective view of a manifold according to an example.
[0008] FIG. 4B is a partially exploded perspective view of a system including a manifold and a dripless connector according to an example.
[0009] FIG. 5A is a perspective view of a system including a manifold according to an example.
[0010] FIG. 5B is a perspective section view of a system including a manifold according to an example.
[0011] FIG. 8A is a section view, taken along line A-A of FIG. 4B , of a system including a dripless connector according to an example.
[0012] FIG. 6B is a section view, taken along line B-B of FIG. 4B , of a system including a dripless connector according to an example.
[0013] FIG. 7 is a perspective view of a system including a manifold according to an example.
[0014] FIG. 8 is a perspective view of a system including a manifold and dripless connector according to an example.
[0015] FIG. 9 is a perspective view of a dripless connector according to an example.
[0016] FIG, 10 is a perspective view of a female dripless connector according to an example.
[0017] FIG. 11 is a perspective view of a cap according to an example.
[0018] FIG. 12 is a perspective section view of a cap according to an example.
[0019] FIG. 13 is a perspective view of a system including a dripless connector according to an example.
DETAILED DESCRIPTION
[0020] Servicing water-cooled arrangements may be difficult, time consuming, and expensive. Disassembly incurs risks that other elements in the nearby assemblies could be damaged, and imposes a need to shutdown otherwise functional units to drain the assembly. A leak in any of the elements may drain the assembly and put other units at risk of overheating, as well as causing water damage.
[0021] Example systems provided herein may provide thermal services (e.g., cooling) to a computing system such as a server and/or rack of servers, based on a blind mate dripless connector (e.g., a connector including an automatic integrated shut-off valve). The dripless connector may “float” or translate to accommodate movements associated with assembly, shipping, installation, usage, or other events such as vibration, accidents, earthquakes, and so on. Examples may be constructed in increments of one rack unit (i.e., 1U), to match sizes of various servers. The floating dripless connector may accommodate movement of the computing system within a rack, and/or movement of an element/component within a computing system.
[0022] Examples based on the floating dripless connector may enable enhanced serviceability, reliability, thermal performance, and cost reductions for computing systems. Fluid couplings may be achieved without the use of hoses that are difficult to install, such that example cooling solutions may include individual flow control shut-off for each 1U cooling unit. Server issues (e.g., failures) or other service events may be addressed individually, without needing to shut down and/or disassemble large groups of servers and stop water flow simultaneously to large portions of the rack to remove an entire cooling wall assembly. The blind mate floating dripless connector enables the capability to diagnose and investigate issues at an individual level, without needing to disassemble an entire rack to remove one computing system. Additionally, examples described herein enable easy upgrades to a particular computing system, without the difficulty associated with disassembling and/or interrupting cooling to the entire rack/system.
[0023] FIG. 1 is a block diagram of a system 100 including a dripless connector 110 according to an example. The dripless connector 110 is slidably mounted to a manifold 140 . The dripless connector 110 includes a base 120 and an extension 130 .
[0024] The dripless connector 110 is slidable along a floating direction 122 . The extension 130 is associated with an engagement direction that is substantially non-parallel to the floating direction, e.g., into and out of the page as shown in FIG. 1 . Accordingly, the extension 130 may engage another element to establish a fluid flow through the dripless connector 110 , based on a blind mate snap-together fit independent of the floating direction. Additionally, the dripless connector 110 is slidable without needing to disengage or otherwise affect the connection established by the extension 130 , ensuring a reliable fluid seal even when components shift or move. As used herein, the terms slidable, floating, movable, and so on may include omnidirectional movements, e.g., along multiple axes. Accordingly, example dripless connectors 110 may be slidable along an X-axis and Y-axis, which are substantially non-parallel to the engagement direction (i.e., the Z-axis). In an example, the X-axis may be along a major axis of an elongated recess in the manifold, and the Y-axis may be along a minor axis of the recess, Accordingly, a recess in the manifold (or other non-recessed corresponding feature of the manifold to receive the dripless connector) may be larger than a corresponding dripless connector to be received at the recess. The omnidirectional slidability of the dripless connector may be based on omnidirectional clearances between the dripless connector and the manifold, to accommodate the floating dripless connector while enabling a fluid seal.
[0025] The manifold 140 may be provided at a rack or computing system. The manifold 140 may provide a fluid supply and fluid return for a plurality of dripless connectors 110 , such that a dripless connector 110 may be used for supplying fluid (e.g., cool fluid) or returning fluid (e.g., warm fluid). Various fluids may be used, such as coolant based on water or all, or other materials having desirable characteristics for heat transfer.
[0026] FIG. 2A is a block diagram of a system 200 including a dripless connector 210 in a first position according to an example. The system 200 includes a rack 204 to house a manifold 240 and receive a computing system 205 . The manifold 240 includes a recess 242 in which the dripless connector 210 is slidably mounted. The rack 204 includes an element 202 , to which the dripless connector 210 is engaged. The element 202 and dripless connector 210 are slidable, while engaged, in the floating direction 222 . The element 202 may be a thermal bus bar (TBB) that is movable within the rack 204 . As shown, the element 202 is moved away from component 206 , allowing a gap between the element 202 and the component 206 to enable easy installation of the computing system 205 in the rack 204 . The gap allows the computer system 205 or components therein to be installed without risking contact and/or damage to the computer system components or element 202 , while using improved tolerances for a very snug fit after the gap is closed. In alternate examples, the dripless connector 210 may be connected directly to a component 206 (e.g., to the computing system 205 , or to a heat-generating element of the computing system 205 , directly or indirectly).
[0027] The manifold 240 may form a wall structure within the rack 204 to provide fluid flow, as a rack-based cooling solution. In an alternate example, a manifold 240 may be provided at a computing system 205 directly, as an individual server-based cooling solution in the server. The manifold 240 may be formed of metal such as aluminum. Systems 200 may be pre-assembled and shipped. During assembly, shipping, and/or site installation, an integrated structure of multiple servers 205 in system 200 may experience shifting/movement. The floating dripless connector 210 can move along the floating direction 222 , to absorb shock and vibe and prevent damage or leaks, in contrast to a fixed rigid connector fitted directly to a member. The dripless connector 210 enables protection even in earthquakes or other unusual situations, in addition to shipping and normal use of system 200 .
[0028] In examples where element 202 is a TBB, heat may be transferred away from the computing system 206 (i.e., component 206 ) through a dry thermal pad interface between component 206 and element (TBB) 202 , where TBB 202 circulates fluid to remain cool without circulating fluid through component 206 . The TBB 202 is movable to close an air gap between the TBB 202 and the component 206 . Thus, thermal connection between the TBB 202 and the component 206 may be achieved by moving the TBB 202 over to compress against the component 206 with a high amount of precision and force, for heat transfer to the TBB 202 and its internal circulating fluid.
[0029] Thus, the manifold 240 may be set into the rack 204 to remain immobile relative to the computing system 230 and/or component 206 . In an alternate example, the manifold 240 may serve as a structural support for the rack 204 and/or computing system 230 .
[0030] FIG. 2B is a block diagram of a system 200 including a dripless connector 210 in a second position according to an example. The dripless connector 210 has remained engaged to the element 202 , which has translated the dripless connector 210 along a floating direction. The element 202 is in contact with the component 206 (i.e., having closed the air gap between the element 202 and the component 206 ). Accordingly, the dripless connector 210 has maintained a fluid seal with the element 202 and manifold 240 , while sliding relative to the manifold 240 .
[0031] An element 202 (e.g., TBB) may be provided at computing system 205 , such that a plurality of computing systems 205 (e.g., servers) may be provided with their own respective element 202 that communicates via a corresponding dripless connector 210 to the manifold 240 . Thus, the manifold 240 may be associated with a plurality of independently slidable dripless connectors 210 . A computing system 205 may provide a handle to actuate side-to-side movement for engaging element 202 with the component 206 .
[0032] In an example, a manifold 240 may include ten dripless connectors 210 that communicate via supply/return paths of the manifold 240 . The plurality of dripless connectors 210 are independently movable/slidable along the floating direction 222 , and a computing system 205 may be independently disconnected from its dripless connector 210 without disrupting fluid flow or operation of other computing systems 205 . A plurality of computing systems 205 may be integrated into a Performance Optimized Datacenter (POD) and shipped assembled together as a unit, whereby the floating dripless connector 210 may avoid problems from stress/shock/vibe experienced by the entire POD. In an alternate example, the computing system 205 may be a liquid-cooled server where the dripless connector 210 connects directly to the computing system 205 (i.e., without using the element 202 ). The dripless connector 210 may be self-aligning, including a lead-in and/or angled funnel to self-align and mate the dripless connector 210 , regardless of its location along the floating direction 222 prior to engagement, Thus, the dripless connector 210 can tolerate misalignment before being connected, and handle shock/vibe movement after being connected.
[0033] An example system 200 may support server/rack configurations that are not fully populated, allowing for half-tray applications including cooling, the use of storage trays, and other features that may be added or removed on-the-fly during operation of the system 200 . For servicing and/or upgrades, operations may continue without needing to shut down other unaffected systems or stop their coolant/water flow. Individual systems may be serviced on an as-needed basis, and a single system 205 at a time may be removed via front access to the system 200 . A system 205 may be compatible with a dry-disconnect cooling system, such as a 1U TBB that may move side-to-side when a computing system 205 is inserted in or removed from the rack 204 .
[0034] Thus, the floating blind mate dripless connector 210 enables alternate examples to have cooling integrated into the computing system 205 , for further improvements to cooling effectiveness and cost reduction. Robust blind-mate dripless connectors 210 provide a repeatable and reliable process of connection, minimizing assembly work and need for lengthy quality testing before shipping. Individual units may be serviced, and the use of an integrated valve at the dripless connector 210 avoids a need to shut down and/or remove a large portion (such as a heavy wall full of TBB units) of a rack 204 . A water wall of a rack 204 may be customized for using storage trays and other features that may be individually added/removed from the example systems described herein.
[0035] FIG. 3A is a side view of a system 300 including a dripless connector 310 according to an example. A plurality of dripless connectors 310 are slidably mounted to a manifold 340 . A fitting 345 is to provide inlet and return fluid paths for the manifold 340 .
[0036] In an example, the dripless connector 310 may extend 0.575-0.875 inches from the manifold 340 , and the dripless connectors 310 may be spaced from each other 0.918 inches. The manifold 340 may be two inches deep, 1.475 inches wide, and 17.5 inches tall. Pairs of connectors may be arranged on 1U increments of 1.75 inches. Connectors may be offset from each other by 0.140 inches. A dripless connector may translate in the floating direction by 0.125 inches. Specific dimensions and measurements may be changed in various examples, and the foregoing are provided merely as guidelines.
[0037] FIG. 3B is a front view of a system 300 including a dripless connector 310 according to an example. A plurality of dripless connectors 310 are shown in a staggered arrangement on the manifold 340 . A cap 350 is to slidably secure a dripless connector 310 to the manifold 340 . The manifold 340 may support a circuit board 341 . The dripless connector 310 is shown in a first position, and may be biased to the first position based on spring 360 .
[0038] The blind mate dripless connector 310 may be slidably secured to the manifold 340 by a cap 350 . The dripless connectors 310 are shown offset from each other in a “zig-zag” pattern. In alternate examples, the dripless connectors 310 may be aligned in a straight pattern or other pattern. The cap 350 may be secured to the manifold using various techniques, such as a press-fit arrangement. O-rings may be used in the system 300 (e.g., at the dripless connector 310 , at the cap 350 , at the fitting 345 , etc.) to allow the dripless connector 310 to float and move while maintaining a fluid seal. The cap 350 may include a slot arranged along the floating direction, to provide clearance for the dripless connector 310 to translate freely left and right. A spring 360 may provide a biasing force to the dripless connector 310 along the floating direction. The spring 360 is to bias the dripless connector 310 to a first position, which may be aligned for coupling. The first position of the dripless connector 310 may facilitate proper connection with a corresponding mating receptacle connector, e.g., on a server cooling unit, on an in-wall TBB, or on other components/elements. The spring MO may be layered under the press-in cap 350 , and in alternate examples may be placed on the same level with, or above, the cap 350 relative to the manifold 340 .
[0039] The spring 360 is shown as a coil spring, and may be various other types of springs not specifically shown. In alternate examples, the spring 360 may be a full-perimeter circular spring to bias the dripless connector 310 in multiple directions, and may be a u-shaped spring for unidirectional biasing along the floating direction.
[0040] The spring 360 may be secured in the proper position by the cap 350 , by the manifold 340 (e.g., in a manifold recess), and/or by the dripless connector 310 . The spring 360 may thereby push against a base of the dripless connector 310 , for stability and avoiding the creation of a torque moment when biasing the dripless connector 310 toward the first position. In alternate examples, the spring 360 may be omitted and the dripless connector 310 may be self-aligning within its full range of floating motion (e.g., based on use of a large lead-in and/or funnel), to safely and securely allow the dripless connector 310 to align and mate.
[0041] The system 300 may include a circuit board 341 , such as a printed circuit board (PCB) or flexible circuit board etc. The circuit board 341 may include an electrical connector having spring-loaded posts or “fingers” to communicate electrical signals to/from a mated element/component. Accordingly, the circuit board 341 may communicate with various electrical features of the installed element/component, such as integrated sensors, active control valves, and so on. Accordingly, while the installed element/component may mate with a fluid connection via the dripless connector 310 , it also may mate with an electrical connection via the circuit board 341 . The electrical connection is to enable electrical signals such as feedback of happenings in the element/component, and/or enable the system 300 to operate/direct valves or other features of the element/component, Thus, remote control, reaction, and/or communications with coupled systems are enabled, providing information such as server temperatures, internal water temperatures, pressures, flows, and so on, while enjoying a quick connect/disconnect interface.
[0042] The circuit board 341 enables a blind-mate electrical connection to transfer signals/data without a need to separately place wiring or otherwise plug-in electrical connections when a computing system is installed (i.e., into a rack). The flexible contacts allow for sideways translation while maintaining a floating electrical connection. Spring-loaded contacts/fingers of the circuit board 341 may contact corresponding pads at the computing system, and translate side-to-side in the floating direction along with the dripless connector 310 . The electrical contacts thereby may slide on the electrical contact pads without breaking the electrical connection. The circuit board 341 may be supported and aligned by the manifold 340 , and the circuit board 341 may be wired to elements supporting the manifold 340 for communicating signals, such as a rack-based aggregator positioned behind the manifold (not shown). Alternate examples may support contactless technology for transmitting electrical signals and/or power, such as flow-powered sensors, radio-frequency identification (RFID), magnetics, and so on that do not need a physical direct connector link.
[0043] FIG. 4A is a perspective view of a manifold 440 according to an example. The manifold 440 includes a recess 442 to receive a dripless connector. The manifold 440 also includes a protrusion 447 . The recess 442 is elongated to allow slidable movement of the dripless connector at the recess 442 , while maintaining a fluid seal with the manifold 440 . The recess 442 includes a passage 443 for fluid flow to/from the dripless connector.
[0044] The recess 442 is shown as a counter-bored oval recess in the manifold 440 . The recess 442 may be formed using various techniques, such as machining, molding, and so on. The passage 443 enables fluid flow regardless of the position of a dripless connector. The protrusion 447 enables a mounting area, for securing the manifold 440 to other objects (such as a rack), and for securing other objects (such as a sensor) to the manifold 440 . In alternate examples, the protrusion 447 may be omitted.
[0045] FIG. 4B is a partially exploded perspective view of a system 400 including a manifold 440 and a dripless connector 410 according to an example. The dripless connector 410 is received at the recess 442 of the manifold 440 , and secured with the cap 450 . The dripless connector 410 may include an o-ring 426 . The fitting 445 may be used to couple supply/return fluid lines to the manifold 440 . The line A-A corresponds to a section view shown in FIG. 6A , and the line B-B corresponds to a section view shown in FIG. 6B .
[0046] The exploded view shows cap 450 being assembled to manifold 400 based on a press-fit, such as an interference fit. In alternate examples, the cap 450 may be removably secured to the manifold 440 by fasteners or other techniques.
[0047] The dripless connector 410 may be sealed to the cap 450 and/or the manifold 440 based on o-rings 426 . An o-ring 426 may be used on a top surface of the dripless connector 410 to seal against the cap 450 , and an o-ring 426 may be used on a bottom of the dripless connector 410 to seal against the manifold 440 .
[0048] The fitting 445 may send/receive fluid flow to/from the manifold 440 . The fitting 445 may be fit to an end of the manifold 440 . The manifold 440 may include end passages (not shown) to allow flow to/from the fitting 445 . In alternate examples, the fitting 445 may be omitted, and supply/return fluid lines may be coupled to the manifold 440 without the separate fitting 445 (e.g., based on connectors boring directly into the manifold 440 ).
[0049] FIG. 5A is a perspective view of a system 500 including a manifold 540 according to an example. The manifold 540 includes a fitting 545 and a plate 549 . The fitting 545 may be coupled directly to the manifold 540 , without a need for the end-cap style of fitting as shown in FIG. 4B , The plate 549 may be used to secure the fitting 545 via removable fasteners. In an alternate example, the plate 549 also may be used as a removable cap to secure a floating dripless connector (not shown in FIG. 5A ), and/or may be used to removably secure a cap itself (not shown in FIG. 5A ).
[0050] FIG. 5B is a perspective section view of a system 500 including a manifold 540 according to an example. The manifold 540 includes a fitting 545 and a plate 549 . The manifold 540 includes a first chamber 546 and a second chamber 548 .
[0051] The manifold 540 is shown divided front from back to provide the first chamber 546 and the second chamber 548 . The fitting 545 is shown bypassing fluid communication with the first chamber 546 , and enabling fluid communication with the second chamber 548 . Similarly, a dripless connector (not shown) may selectively enable fluid communication with the first chamber 546 and second chamber 548 based on a depth of the connector, enabling such dripless connectors to be in-line with each other without a zig-zag offset shown in other drawings, while still alternating between supply and return chambers of the manifold 540 .
[0052] FIG. 6A is a section view, taken along line A-A of FIG. 4B , of a system 600 including a dripless connector 610 according to an example. A base 620 of the dripless connector 610 is secured to a manifold 640 by a cap 650 . The base 620 and/or cap 650 may include o-rings 626 . An extension 630 of the dripless connector 610 may extend away from the manifold 640 through the cap 650 . The manifold 640 includes a protrusion 647 and passage 643 .
[0053] A spring (not shown) may be positioned between the manifold 640 and the base 620 of the dripless connector 610 (to the right of the base 620 as illustrated), to bias the dripless connector 610 toward the first position (to the left as illustrated). O-rings 626 enable a fluid seal between the base 620 and the cap 650 and manifold 640 . Translation of the connector 610 enables fluid flow to be maintained via the passage 643 .
[0054] FIG. 6B is a section view, taken along line B-B of FIG. 4B , of a system 600 including a dripless connector 610 according to an example. A plurality of dripless connectors 610 are shown in communication with first chamber 646 and second chamber 648 via passages 643 .
[0055] The section view cuts through a center of two dripless connectors, and through a portion of two of the dripless connectors 610 , illustrating the zig-zag offset between dripless connectors 610 . The offset enables two of the illustrated dripless connectors 610 to be in fluid communication with the first chamber 646 , and two of the illustrated dripless connectors 610 to be in fluid communication with the second chamber 648 (where the first and second chambers 646 , 648 are defined by a zig-zag divider, e.g., as shown in FIG. 7 ).
[0056] FIG. 7 is a perspective view of a system 700 including a manifold 740 according to an example. The manifold 740 is shown from a back side with a back plate removed for visibility, revealing a divider 744 separating the manifold 740 into first chamber 746 and second chamber 748 . The manifold 740 is in fluid communication via passages 743 alternating between the first chamber 746 and second chamber 748 . The first chamber 746 and/or second chamber 748 are also in fluid communication with the fitting 745 (passages in the manifold 740 to the fitting 745 are not shown in FIG. 7 ).
[0057] The divider 744 is zig-zag to accommodate a geometry of arrangement of the dripless connectors that would extend from the opposite side of the manifold (not shown), partitioning between hot and cold (supply and return) fluid paths of the first chamber 746 and second chamber 748 . The divider may be insulated, based on plastic (e.g., a metal manifold 740 having a plastic divider 744 separating the fluid paths). The insulated divider 744 is to minimize thermal conduction between the first chamber 746 and the second chamber 748 , The manifold 740 and/or divider 744 (as well as any other component of the example systems throughout) may be constructed using techniques such as die cast, extrusion, injection molding, machining, epoxy, welding, and so on, including combinations of techniques. The manifold 740 may be sealed with a back plate (not shown) to create an enclosed volume with the first chamber 746 and second chamber 748 .
[0058] FIG. 8 is a perspective view of a system 800 including a manifold 840 and dripless connector 810 according to an example. Dripless connector 810 may be slidable at recess 842 of the manifold 840 . The dripless connector 810 may include an o-ring 826 . The cap (not shown) to secure the dripless connector 810 to the manifold 840 is removed, to illustrate a first position 812 and a second position 814 of the dripless connector 810 superimposed over each other. An extent of the floating/slidable movement of the dripless connector 810 is visible, enabled by the elongated recess 842 and corresponding shape of a base of the dripless connector 810 .
[0059] The dripless connector 810 is shown with a floating range of motion of 0.125 inches between the first position 812 and the second position 814 , although larger or smaller ranges are possible in alternate examples (e.g., by using a wider elongated recess 842 or narrower base for the dripless connector 810 ). A biasing spring (not shown) may be positioned in the gap between the recess 842 and base of the connector 810 , i.e., to the left of the base of the dripless connector 810 . A cap (not shown). when inserted, may secure the spring and dripless connector 810 in place at the manifold 840 .
[0060] FIG. 9 is a perspective view of a dripless connector 910 according to an example. The dripless connector 910 includes a base 920 and an extension 930 . The base 920 includes a cutout 924 and a lip 928 . The extension 930 includes an undercut 934 , a valve 936 , and a bevel 938 .
[0061] The base 920 of the dripless connector 910 may be elongated, to mate with a recess of the manifold. The base 920 is shown generally as an oval, and other shapes are possible including a circle, square, rectangle, and so on. A corresponding accommodating shape at the manifold may be used (e.g., a corresponding manifold recess, or plate on the surface of the manifold in examples where a recess is not used for slidably mounting the dripless connector).
[0062] The base 920 may include a lip 928 , shown as an upper raised perimeter lip structure corresponding to an upper o-ring (not shown). A lower lip (not shown) also may be used, corresponding to a lower o-ring (not shown) at an underside of the base 920 . The lip 928 may be formed as a wall to minimize over-deflection/tilting of the dripless connector 910 , to retain the o-ring's shape and prevent over-compression and leakage of the o-ring.
[0063] The base 920 may include cutout 924 . Cutout 924 may be a circular portion, shaped to accommodate a biasing spring (not shown). Thus, cutout 924 may be a hole corresponding to a traditional coil spring, an arc (as shown) corresponding to a U-shaped spring around a portion of the perimeter (e.g., to bias the base 920 toward a first position), and other shapes.
[0064] The extension 930 of the dripless connector 910 includes a lead-in bevel 938 , and an undercut 934 . The bevel 938 is to facilitate blind-mating and self-alignment of the dripless connector 910 . The undercut 934 is to allow space for a ledge of a cap (not shown) to surround the extension, to provide a fluid seal and secure/stabilize the dripless connector 910 to ensure smooth translation along the floating direction and minimize deflection/tilting of the extension 930 during self-alignment.
[0065] FIG. 10 is a perspective view of a female dripless connector 1011 according to an example. Female dripless connector 1011 includes an extension 1030 coupleable to an extension from a male dripless connector, such as the extension 930 of dripless connector 910 of FIG. 9 . Female dripless connector 1011 may include a funnel 1029 , shown in FIG. 10 as generally circular (although elongated and other shapes are possible).
[0066] The female dripless connector 1011 provides a smaller body size for coupling with the dripless connector 910 , while including a larger funnel 1029 for blind-mating self-alignment. The funnel 1029 may be wide enough to accommodate a range of motion of the dripless connector 910 . Thus, the funnel 1029 may provide a “don't-care” alignment feature, allowing omission of a biasing spring for the dripless connector 910 , and enabling self-alignment even if a connector is not in a first position. The funnel can self-align the dripless connector 910 to bring it to the first position during engagement, regardless of whether the corresponding connector is biased.
[0067] FIG. 11 is a perspective view of a cap 1150 according to an example. The cap 1150 includes an overlap 1152 and ledge 1154 . The overlap 1152 is to contact the manifold (not shown), to provide a secure fit and seal. The ledge 1154 is at a base of the cap 1150 to provide a sealing surface for an o-ring (not shown) of a base of the dripless connector (not shown) to contact, regardless of translation and/or floating movement of the dripless connector. The ledge 1154 also may help to retain and align an undercut of the dripless connector. The ledge 1154 is positioned along an inner perimeter of the cap 1150 . A portion of the ledge 1154 is removed (toward the right as shown in FIG. 11 ), to enable a large range of translation of the dripless connector toward the removed area.
[0068] FIG. 12 is a perspective section view of a cap 1250 according to an example. The cap 1250 includes o-ring 1226 , overlap 1252 , and ledge 1254 . The cap 1250 may be formed of a rigid material such as metal. Thus, the overlap 1252 may form a rigid barbed interface for a press-fit seal against the manifold (not shown). The manifold also may be metal to engage with the overlap 1252 in an interference pressed fit. The angled/barbed feature of the overlap 1252 enables the cap to be smoothly insertable into a recess of the manifold, such that the barb of the overlap 1252 may bite in to the manifold and prevent the cap 1250 from being ejected from the manifold when experiencing fluid pressure. The o-ring 1226 may be placed around an outside of the cap, ensuring a fluid seal at the junction between the cap 1250 and manifold to withstand fluid pressure. The cap 1250 may be made of various materials to withstand fluid pressure and maintain integrity with the manifold. In an example, the cap 1250 may be formed of a material as hard as, or harder than, the manifold, enabling the barbed overlap 1252 to bite into and grip the manifold. In an alternate example, the barbed overlap 1252 may be formed on the manifold to bite into the cap 1250 . In yet another alternate example, the overlap may be omitted and the cap 1250 may be removably secured with fasteners and/or a plate (e.g., similar to the plate 549 of FIG. 5A ), to enable inspection, repairing, changing, and other servicing of the dripless connector, manifold, passageways, and other features of the dripless connector systems accessible by removing the cap 1250 from the manifold.
[0069] FIG. 13 is a perspective view of a system 1300 including a dripless connector 1310 according to an example. Manifold 1340 includes a plurality of male dripless connectors 1310 coupled to corresponding female dripless connectors 1311 associated with an element 1302 (e.g., a thermal bus bar of a computing system). The manifold 1340 also includes a fitting 1345 and protrusion 1347 .
[0070] As shown, two of the dripless connectors 1310 are engaged with the element 1302 . Accordingly, the element 1302 may float with respect to the manifold 1340 , without causing damage or leakage due to the floating dripless connectors 1310 maintaining a fluid seal. Furthermore, the element 1302 may fully receive the benefits from fluid flow to/from the manifold 1340 , even though the upper dripless connector 1310 is disconnected. The element 1302 may engage the dripless connectors 1310 by moving toward the right as illustrated in FIG. 13 , along an engagement direction. The dripless connectors 1310 are slidable along a floating direction, shown as upward and leftward in FIG. 13 . Accordingly, the engagement direction of the dripless connectors 1310 is substantially non-parallel to the floating direction. In alternate examples, the interface between the engaged connectors may allow some movement/tolerance without breaking the fluid seal. | An example device in accordance with an aspect of the present disclosure includes a dripless connector that has a base and an extension. A manifold is to slidably mount the dripless connector. The base of the dripless connector is slidable, relative to the manifold, along a floating direction substantially non-parallel to an engagement direction of the extension of the dripless connector. | 7 |
BACKGROUND
[0001] Refrigerated, canned dough products have been very popular with consumers. In addition to the ease of use of canned dough products, the quality of the baked products made from refrigerated, canned dough has vastly improved over the years.
[0002] As consumers demand more high quality, nutritious food products, consumer food product manufacturers work to continue to develop food products that meet these consumer demands. Balancing the nutrition profile of a food product with its desired organoleptic properties has often been a challenge to consumer food product manufacturers. As such, manufacturers seek to increase the nutritive value of a food product without noticeably altering its organoleptic properties by using food ingredients that have the requisite functional properties but have added nutritive value, such as added vitamins and minerals.
[0003] Refrigerated dough product manufacturers, in addition to facing the nutrition demands of consumers, are faced with the challenge of meeting these demands while working within the constraints associated with refrigerated dough product manufacturing, which in large part revolve around optimizing the rate of carbon dioxide gas generation in a canned dough system. Such optimization makes it possible to rapidly expand the dough to reach a desired volume, thereby reducing headspace gas volume and the concomitant loss in dough and finished product quality. The initial expansion of the leavened dough to seal a ventable can from within is followed by an increase in the pressure within the can resulting from the continued carbon dioxide generation by the leavening agents. The pressure increase and gas generation help to build and sustain the internal gas cell structure of the dough, which results in excellent finished product characteristics typically associated with leavened dough products.
[0004] The ability to optimize the rate of carbon dioxide generation in a canned dough system has, however, been a challenge to refrigerated dough manufacturers for decades. Without such optimization, a canned refrigerated dough product suffers from not sufficiently proofing and expanding to seal the can, which results in irreversible product failure. Refrigerated dough manufacturers therefore constantly strive to develop and utilize ingredients, formulations, systems and processes to attain the optimum rate of carbon dioxide generation in refrigerated dough products on a commercial scale.
[0005] It has been uniquely challenging for refrigerated canned dough manufacturers to provide consumers with food products with an increased nutritive value while attempting to optimize carbon dioxide generation because of the delicate balance of ingredients, formulations, systems and processes required to achieve a suitable refrigerated dough product. Even ingredients that are intended to be used in dough products often do not meet the complex requirements of a refrigerated canned dough system.
[0006] One example of such an ingredient is a calcium-based leavening acid, such as calcium acid pyrophosphate. Calcium based leavening acids, while having many desirable properties, have typically been difficult to use in canned or packaged refrigerated dough systems because these leavening acids generally do not react fast enough to generate carbon dioxide at or above a critical rate of gas evolution, and therefore are unable to suitably expand the dough to seal the package or can from within, and then pressurize the dough within the package or can. As such, calcium-based leavening agents, although having the benefit of potentially increasing the calcium level and decreasing the sodium level of products made from dough, have not typically been used in the industry to manufacture refrigerated canned dough products.
SUMMARY
[0007] It has been unexpectedly discovered that by using leavening agents, which are typically encapsulated, in their unencapsulated form, in combination with a calcium-based leavening acid, it is possible to achieve or exceed the critical rate of gas evolution for a particular product while improving the nutritional properties of the product.
[0008] The present invention is directed to a refrigerated dough system which includes a dough product contained in a package. The dough product includes a base, an expansion leavening acid, and a pressurization leavening acid. The pressurization leavening acid may be a calcium-based leavening acid. The base, expansion leavening acid, and pressurization leavening acid are each unencapsulated. The expansion leavening acid, when combined with the base, is capable of generating gas which causes the dough product to expand to a degree sufficient to seal the package from within. The pressurization leavening acid, when combined with the base, is capable of generating gas within the dough product to pressurize the dough product after the package is sealed. The internal system pressure is sustained inside the package under refrigeration conditions over a period of time. This internal system pressure is less than the pressure sustained by the expansion leavening acid at a 100% neutralizing value in a similar dough product, and greater than the pressure sustained by the pressurization leavening acid at a 100% neutralizing value in a similar dough product.
[0009] The present invention is also directed to a method of making a refrigerated dough product. This method involves mixing dough ingredients, including an unencapsulated leavening base, an unencapsulated expansion leavening acid, and an unencapsulated pressurization leavening acid, together to make a dough. The dough is then placed inside a ventable package with an opening. The opening of the package is subsequently closed to create a headspace including air inside the package. After the opening is closed, the package is sealed from within by action of the expansion leavening acid and the base, which together generate gas in the dough to expand the dough, thereby venting out the air in the headspace and filling the headspace with expanded dough. Pressure is then generated inside the package by action of the pressurization leavening acid and the base, which together generate additional gas in the expanded dough.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 shows plots of can pressure, after 24 hours, versus the weight of the canned dough for dough products prepared using the following leavening acids: glucono-delta-lactone (GDL) as the sole leavening acid at a 25% neutralizing value; LEVONA® leavening agent as the sole leavening acid at a 75% neutralizing value; and a combination of GDL at a 25% neutralizing value and LEVONA® leavening agent at a 75% neutralizing value.
[0011] FIG. 2 shows plots of can pressure, after 24 hours, versus the weight of the canned dough for dough products prepared using the following leavening acids: GDL as the sole leavening acid at a 25% neutralizing value; LEVONA® leavening agent as the sole leavening acid at a 75% neutralizing value; and a combination of GDL at a 25% neutralizing value and LEVONA® leavening agent at a 75% neutralizing value.
[0012] FIG. 3 shows plots of can pressure, after 24 hours, versus the weight of the canned dough for dough products prepared using the following leavening acids: LEVONA® leavening agent at a 100% neutralizing value; a combination of LEVONA® leavening agent at a 90% neutralizing value and GDL at a 10% neutralizing value; a combination of LEVONA® leavening agent at a 80% neutralizing value and GDL at a 20% neutralizing value; a combination of LEVONA® leavening agent at a 70% neutralizing value and GDL at a 30% neutralizing value; and a combination of LEVONA® leavening agent at a 60% neutralizing value and GDL at a 40% neutralizing value.
[0013] FIG. 4 shows plots of volume of CO 2 evolved over time for dough products prepared using the following leavening acids: GDL at a 100% neutralizing value; CAL-RISE® calcium acid pyrophosphate leavening agent at a 100% neutralizing value; GDL at a 25% neutralizing value; CAL-RISE® leavening agent at a 75% neutralizing value; and a combination of GDL at a 25% neutralizing value and CAL-RISE® leavening agent at a 75% neutralizing value.
[0014] FIG. 5 shows plots of volume of CO 2 evolved over time for dough products prepared using the following leavening acids: GDL at a 100% neutralizing value; LEVONA® leavening agent at a 100% neutralizing value; GDL at a 25% neutralizing value; LEVONA® leavening agent at a 75% neutralizing value; and a combination of GDL at a 25% neutralizing value and LEVONA® leavening agent at a 75% neutralizing value.
DESCRIPTION
[0015] Leavening agents having various rates of carbon dioxide generation have been used to prepare canned refrigerated dough products. The problems associated with using these leavening agents stem from their very nature—the slow-acting leavening agents generate carbon dioxide so slowly that some of the generated gas escapes out of the package before the dough is sufficiently proofed to fill and seal the package, rather than being entrapped within the dough, causing poor dough conditions and volume. In addition, slow-acting leavening agents that contain phosphates may have taste issues that limit their use and may require additional ingredients to achieve the desired taste profile in the finished product.
[0016] Fast-acting leavening agents, on the other hand, generate carbon dioxide quickly, sometimes while the dough ingredients are being mixed, so the dough begins to expand before it is suitably packaged to retain the gas within the dough. To overcome the problems associated with fast-acting leavening agents, one or more of the leavening components (acid and/or base) are encapsulated to slow the reaction rate. Encapsulated leavening agents are typically much more expensive than conventional leavening agents, and are not entirely problem free, as the encapsulation material may still prematurely release the leavening agent. Other methods of “sequestering” one or more of the fast-acting leavening agents is by laminating the dough, as described in U.S. Pat. No. 4,526,801.
[0017] The leavening composition in accordance with the present invention can be used to make a packaged dough product of the present invention, wherein the dough in the package is sufficiently expanded to seal the package from within, and the package is sufficiently pressurized by the dough expansion to retain gas within the dough, which ultimately results in desirable baked product characteristics. The package may be a ventable composite can, such as the packages described in U.S. Pat. Nos. 3,510,050 and 3,879,563. Other types of ventable cans and other ventable packaging are also contemplated to be suitable for use in accordance with the present invention. “Ventable can” as used herein shall refer to any can or other package having at least one vent through which headspace air may escape from the can as the dough expands inside the can to seal the can from within.
[0018] In one embodiment of the present invention, the dough product includes a leavening composition comprising an unencapsulated leavening base and a blend of leavening acids. The leavening acids include an expansion leavening acid and a pressurization leavening acid. Either or both of the expansion leavening acid and pressurization leavening acid can be unencapsulated. The expansion leavening acid is capable of generating gas when combined with the base to initially proof and expand the dough product to a degree sufficient to cause the dough to seal the package from within the package. The pressurization leavening agent is capable, when combined with the base, of generating gas within the dough product to subsequently pressurize the dough product inside the sealed package in an amount sufficient to sustain an internal system pressure inside the package under refrigeration conditions over a period of time. This period of time ranges from about 1 day to about 120 days.
[0019] In this embodiment, the internal system pressure of the dough product, inside the package under refrigeration conditions over a period of time, is lower than the pressure that is sustained by the expansion leavening acid acting individually at a 100% neutralizing value in a similar dough. The internal system pressure of the dough product, inside the package under refrigeration conditions over a period of time, is also greater than the pressure that is sustained by the pressurization leavening acid acting individually at a 100% neutralizing value in a similar dough.
[0020] As used herein, the expression “neutralizing value” refers to a level of the leavening acid required to react with and neutralize the recited percentage of the leavening base in a given product. The period of time can range from about 1 day to about 120 days, for example, from about 30 days to about 90 days. The internal system pressure can range from about 8 psi to about 20 psi, for example, from about 10 psi to about 20 psi.
[0021] In this embodiment, the expansion leavening acid and the pressurization leavening acid are present in the dough at a ratio of from about 10:90 to about 40:60, prior to reacting with the base. At least one of the expansion leavening acid and the pressurization leavening acid is substantially free of sodium.
[0022] The expansion leavening acid may be a fast-acting leavening agent, such as, but not limited to, glucono-delta-lactone and sodium acid pyrophosphate. Useful examples of expansion leavening acids are those that are capable of causing sufficient dough expansion to seal a can from inside the can at temperatures ranging from about 40° F. to about 70° F. for a period of time sufficient to seal the can, depending, among other things, on the internal can volume and the amount of dough placed inside the can. In some cases, the period of time for sealing the can varies from about 24 hours to about 72 hours after the dough is placed inside the ventable can through its open end and the open end is closed.
[0023] The pressurization leavening acid may be a slow-acting leavening agent such as, but not limited to, calcium acid pyrophosphate. Possible slow-acting leavening agents include the CAL-RISE® leavening agent, which is available from Innophos, Inc. of Cranbury, N.J., US, and LEVONA® leavening agents, which are available from ICL Performance Products LP of St. Louis, Mo., US. Possible LEVONA® leavening agents for use in this invention include LEVONA® OPUS leavening agent, LEVONA® BR10 leavening agent, and LEVONA® MEZZO leavening agent.
[0024] Although the types of leavening acids have been described herein as “expansion” and “pressurization”, those skilled in the art will appreciate that these expressions describe the major function of the leavening acids, but are not intended to preclude each type of leavening acid from performing other functions to a lesser degree as well. For example, although a faster acting expansion leavening agent serves primarily to quickly expand the dough, the same leavening agent may, to some degree, assist with pressurizing the dough over time. Similarly, even though the slower acting pressurization leavening acid serves primarily to generate gas within the dough to sustain an internal pressure within the package over time after the dough has been packaged, the same leavening acid may, to some extent, contribute to the initial dough expansion.
[0025] While not intending to be bound by theory, it is believed that there is a critical rate of gas evolution required in a dough product, below which the carbon dioxide diffuses out of the canned dough and escapes out of the vent or vents in the can, but above which the dough can proof and expand to seal the ventable can from within, following which the necessary pressure within the can may be generated by continued gas evolution. This rate of gas evolution is dependent on many conditions, such as the type of dough and leavening agent, the package volume, and the like.
[0026] The following examples demonstrate the principles involved in the present invention, but are not intended to limit the scope of the invention. All dough products described herein comprise flour, water, and a leavening system, but those skilled in the art will understand that the present invention encompasses dough products comprising additional dough ingredients, such as, but not limited to, plasticizers, stabilizers, conditioners, emulsifiers, flavoring agents, coloring agents, particulate materials, preservation agents, and the like.
Example I
[0027] The overall can pressure of a canned dough product is affected by individual component contributions to can pressure and by the rate of reaction and interactions within the packaged dough system. Can pressures greater than those attained through the use of individual leavening components can be achieved by manipulating the reaction rate of the leavening agents in the dough to achieve the critical rate of gas evolution.
[0028] When calcium acid pyrophosphate is used alone as a leavening acid, the proofing is insufficient to promote effective can pressure. Therefore, the use of calcium acid pyrophosphate, such as LEVONA® leavening agent, as the sole leavening acid does not result in an acceptable canned dough product. The LEVONA® leavening agent acting alone will not develop acceptable can pressure, even when the leavening acid is at a 100% neutralizing value.
[0029] When glucono-delta-lactone (GDL) is used alone as a leavening acid at a low level, a low can pressure is also observed. Furthermore, if the level of GDL is increased, although more gas is generated, it is generated at a rate that is too fast to suitably package the dough. In many cases, if the level of GDL in the dough is increased, the resulting pressure leads to package failure. For these reasons, GDL is conventionally used with an encapsulated base, typically known as “e-soda”. GDL may itself be used in an encapsulated form to delay the onset of the leavening reaction.
[0030] When calcium acid pyrophosphate, such as LEVONA® leavening agent, and GDL are combined, there is a sufficient rate of reaction to initially expand the dough to seal the can, and to continue to proof the dough and develop acceptable can pressure. GDL or sodium acid pyrophosphate (SAPP), and many other leavening acids, can be used in conjunction with a leavening agent comprising calcium acid pyrophosphate to achieve appropriate dough expansion and can pressure development to promote effective proofing in canned dough products.
[0031] The can pressures of canned dough products using the following leavening acids were measured: 1) GDL at a 25% neutralizing value; 2) LEVONA® leavening agent at a 75% neutralizing value; and 3) a combination of GDL at a 25% neutralizing value and LEVONA® leavening agent at a 75% neutralizing value. Sodium bicarbonate was used as the leavening base, and all the leavening agents were unencapsulated. The results of these experiments are shown in the plots of FIGS. 1 and 2 .
[0032] FIG. 1 shows plots of can pressure, after 24 hours, versus the weight of the canned dough used. As shown in this figure, when GDL is used as the sole leavening acid at a 25% neutralizing value, a can pressure of between about 2 psi and 6 psi is attained after 24 hours, for dough weights of between about 325 g and 350 g. Also, when LEVONA® leavening agent is used as the sole leavening acid at a 75% neutralizing value, a can pressure of between about 2 psi and 6 psi is attained after 24 hours. Therefore, neither of the leavening acids, acting alone, is capable of generating sufficient pressure within a canned dough product.
[0033] However, when a combination of GDL at a 25% neutralizing value and LEVONA® leavening agent at a 75% neutralizing value is used as the leavening composition, a can pressure of between about 12 psi and 16 psi is attained after 24 hours. Therefore, unexpectedly, the can pressure attained using the combination of the GDL and the LEVONA® leavening agent is greater than the sum of the pressures attained using the GDL and the LEVONA® leavening agents individually.
[0034] FIG. 2 also shows plots of can pressure, after 24 hours, versus the weight of the dough used. As shown in this figure, when GDL is used as the sole leavening acid at a 25% neutralizing value, a can pressure of between about 4 psi and 10 psi is attained after 24 hours, for dough weights of between about 390 g and 430 g. When calcium acid pyrophosphate, such as LEVONA®, is used as the sole leavening acid at a 75% neutralizing value, a can pressure of between about 7 psi and 11 psi is attained after 24 hours.
[0035] When a combination of GDL at a 25% neutralizing value and calcium acid pyrophosphate leavening agent at a 75% neutralizing value is used as the leavening composition, a can pressure of between about 19 psi and 24 psi is attained. Again, the combination of the expansion leavening agent, GDL, with the pressurization leavening agent, calcium acid pyrophosphate, resulted in the desired pressure ranges as compared to either leavening agent acting individually.
[0036] The can pressures of canned dough products using the following leavening acids were measured: 1) LEVONA® leavening agent at a 100% neutralizing value; 2) a combination of LEVONA® leavening agent at a 90% neutralizing value and GDL at a 10% neutralizing value; 3) a combination of LEVONA® leavening agent at a 80% neutralizing value and GDL at a 20% neutralizing value; 4) a combination of LEVONA® leavening agent at a 70% neutralizing value and GDL at a 30% neutralizing value; and 5) a combination of LEVONA® leavening agent at a 60% neutralizing value and GDL at a 40% neutralizing value. The results of these experiments are shown in the plots of FIG. 3 .
[0037] FIG. 3 shows plots of can pressure, after 24 hours, versus the weight of the dough used. As shown in this figure, when LEVONA® leavening agent is used at a 100% neutralizing value, a can pressure of between about 7 psi and 12 psi is attained after 24 hours.
[0038] When a combination of LEVONA® leavening agent at a 90% neutralizing value and GDL at a 10% neutralizing value is used as the leavening composition, a can pressure of between about 12 psi and 15 psi is attained after 24 hours. When a combination of LEVONA® leavening agent at a 80% neutralizing value and GDL at a 20% neutralizing value is used as the leavening composition, a can pressure of between about 14 psi and 16 psi is attained after 24 hours. When a combination of LEVONA® leavening agent at a 70% neutralizing value and GDL at a 30% neutralizing value is used as the leavening composition, a can pressure of between about 14 psi and 17 psi is attained after 24 hours. When a combination of LEVONA® leavening agent at a 60% neutralizing value and GDL at a 40% neutralizing value is used as the leavening composition, a can pressure of between about 16 psi and 19 psi is attained after 24 hours.
[0039] The data plotted in FIG. 3 illustrates the unexpected result that higher pressures in a canned dough product are attained after 24 hours as the ratio of GDL to LEVONA® leavening agent is increased. This unexpected result is due to the fact that the combination of a fast-acting expansion leavening agent such as GDL with a slower-acting pressurization leavening agent such as LEVONA® achieves the desired rate of gas evolution to initially expand the dough and seal the can from within, and then build and sustain pressure in the can by continuing to generate gas within the dough, all without the need for encapsulating or otherwise sequestering the leavening agents.
Example II
[0040] The can pressure and CO 2 evolution of five different canned dough products was measured. The five canned dough products each contained a soft breadstick dough, so each dough formulation was similar, with the only variation being in the type of leavening acids used in each dough. The following leavening acids were used for the five products: 1) GDL at a 100% neutralizing value; 2) CAL-RISE® calcium acid pyrophosphate leavening agent at a 100% neutralizing value; 3) GDL at a 25% neutralizing value; 4) CAL-RISE® leavening agent at a 75% neutralizing value; and, 5) a combination of GDL at a 25% neutralizing value and CAL-RISE® leavening agent at a 75% neutralizing value. Sodium bicarbonate was used as the leavening base, and all the leavening agents were unencapsulated.
[0041] The CO 2 evolution of the dough products was measured using a Risograph® instrument, available from National Manufacturing Company, Lincoln, Nebr. The Risograph® instrument measures the volume of gas generated over time. The Risograph® tests were each run twice, due to the potential for leaks resulting in lost data.
[0042] The results of the pressure measurements are summarized in Table 1. The results of the Risograph® tests are shown in FIG. 4 . The reference numerals of the FIG. 4 Risograph® plots correspond to the Risograph® chamber reference numerals in Table 1.
[0000]
TABLE 1
Can Pressure Using GDL and CAL-RISE ® Leavening Agent
Risograph ®
Average Weight of
Average Pressure After
Leavening Acid
Chambers
Dough (in gm)
24 Hours (in psi)
GDL - 100% neutralizing value
1, 2
335.5
27.6
CAL-RISE ® leavening agent - 100%
3, 4
338.0
8.8
neutralizing value
GDL - 25% neutralizing value
5, 6
339.2
2.5
CAL-RISE ® leavening agent - 75%
7, 8
339.3
5.5
neutralizing value
Combination: GDL - 25% neutralizing
9, 10
340.2
13.0
value and CAL-RISE ® leavening
agent - 75% neutralizing value
[0043] The Risograph® data is consistent with the can pressure data. The treatments with faster reaction rates have the greatest gas retention due to faster proofing, which leads to a more rapid sealing of the vents of the can. Therefore, the treatments with faster reaction rates have the highest can pressure.
[0044] The treatments wherein the individual leavening acids were at less than 100% neutralizing value produced an inadequate amount of gas for proper dough expansion, gas retention, and can pressurization.
[0045] The use of GDL as a leavening agent at a 100% neutralizing value resulted in a very fast reaction. This reaction sealed the cans of dough the most rapidly and resulted in the highest overall can pressure. However, the reaction was faster than is desirable in processing conditions, due to the fast rate of proofing and the excessive can pressure. The fast rate of proofing results in some proofing occurring before the dough is sufficiently packaged, and the excessive can pressure may result in unacceptable package performance or even package failure.
[0046] The use of CAL-RISE® leavening agent at a 100% neutralizing value resulted in can pressure that was too low. The leavening agent did not react fast enough to generate the amount of CO 2 necessary for dough proofing for expansion and pressurization, and would result in an unacceptable product.
[0047] The use of GDL as a leavening agent at a 25% neutralizing value resulted in a very low can pressure, due to the low level of leavening acid. The use of CAL-RISE leavening agent at a 75% neutralizing value also resulted in a very low can pressure, due to the low level of leavening acid. The CAL-RISE® leavening agent at a 75% neutralizing value produced a slightly lower can pressure than the CAL-RISE leavening agent at a 100% neutralizing value.
[0048] The use of the combination of GDL at a 25% neutralizing value and CAL-RISE® leavening agent at a 75% neutralizing value produced a suitable amount of gas for proper dough proofing and gas retention. These results unexpectedly show that the combination of GDL and CAL-RISE® leavening agent is able to generate more gas than the CAL-RISES leavening agent alone, at a 100% neutralizing value. In addition, these results also unexpectedly show that the can pressure attained using a combination of GDL and CAL-RISE® leavening agent is greater than the sum of the pressures attained using either of the GDL and CAL-RISE® leavening agents individually.
[0049] While not intending to be bound by theory, it is believed that in addition to the leavening effects of each component, the fast-acting GDL helps acidify and decrease the initial pH of the dough through the rapid neutralization of some of the sodium bicarbonate in the dough, resulting in a lower subsequent pH and thereby increasing the reaction rate of the slower reacting calcium acid pyrophosphate leavening agent. This increased reaction rate results in faster proofing and higher can pressure, resulting in an excellent packaged dough product. The subsequent pH of the dough after the base reacts with the expansion leavening agent, such as GDL, is within the optimal pH range for the calcium acid pyrophosphate leavening agent to react with the base and generate gas within the dough. For a dough containing CAL-RISE® leavening agent, this pH range is about 6 to 8.
Example III
[0050] The can pressure and CO 2 evolution of five different canned dough products was measured. The five canned dough products each contained a soft breadstick dough, so each dough formulation was similar, with the only variation being in the type of leavening acids used in each dough. The following leavening acids were used for the five products: 1) GDL at a 100% neutralizing value; 2) LEVONA® leavening agent at a 100% neutralizing value; 3) GDL at a 25% neutralizing value; 4) LEVONA® leavening agent at a 75% neutralizing value; and, 5) a combination of GDL at a 25% neutralizing value and LEVONA® leavening agent at a 75% neutralizing value. Sodium bicarbonate was used as the leavening base, and all the leavening agents used were unencapsulated.
[0051] The CO 2 evolution of the dough products was measured using a Risograph® instrument. The Risograph® tests were each run twice, due to the potential for leaks resulting in lost data.
[0052] The results of the pressure measurements are summarized in Table 2. The results of the Risograph® tests are shown in FIG. 5 . The reference numerals of the FIG. 5 Risograph® plots correspond to the Risograph® chamber reference numerals in Table 2.
[0000]
TABLE 2
Can Pressure Using GDL and LEVONA ® Leavening Agent
Risograph ®
Average Weight of
Average Pressure After
Leavening Acid
Chambers
Dough (in gm)
24 Hours (in psi)
GDL - 100% neutralizing value
1, 2
No data
No data
LEVONA ® leavening agent - 100%
3, 4
337.9
9.8
neutralizing value
GDL - 25% neutralizing value
5, 6
334.7
0.5
LEVONA ® leavening agent - 75%
7, 8
337.9
5.5
neutralizing value
Combination: GDL - 25% neutralizing
9, 10
338.3
15.4
value and LEVONA ® leavening
agent - 75% neutralizing value
[0053] No can pressure data was obtained for the dough products using GDL at a 100% neutralizing value, because the GDL reacted so quickly, the products could not be packaged prior to the reaction.
[0054] The Risograph® data is consistent with the can pressure data. The treatments with faster reaction rates have the greatest gas retention due to faster proofing, which leads to a more rapid sealing of the vents of the can. Therefore, the treatments with faster reaction rates have the highest can pressure.
[0055] The treatments wherein the leavening acids were at less than 100% neutralizing strength produced an inadequate amount of gas for proper proofing and gas retention.
[0056] The use of LEVONA® leavening agent at a 100% neutralizing value resulted in can pressure that was too low. The leavening acid did not react fast enough to generate the amount of CO 2 necessary for dough proofing for expansion or pressurization, and would result in an unacceptable product. As noted above, the use of GDL at a 100% neutralizing value did not result in a useable product due to the extremely fast rate of gas evolution.
[0057] The use of GDL as a leavening agent at a 25% neutralizing value resulted in a very low can pressure, due to the low level of leavening acid. The use of LEVONA® leavening agent at a 75% neutralizing value also resulted in a very low can pressure, due to the low level of leavening acid. As expected, LEVONA® leavening agent at a 75% neutralizing value produced a lower can pressure than the LEVONA® leavening agent at a 100% neutralizing value.
[0058] The use of the combination of GDL at a 25% neutralizing value and LEVONA® leavening agent at a 75% neutralizing value produced a sufficient amount of gas for proper dough proofing and gas retention. These results unexpectedly show that the combination of GDL and LEVONA® leavening agent is able to generate more gas than the LEVONA® leavening agent alone, at a 100% neutralizing value. In addition, these results also unexpectedly show that the can pressure attained using a combination of GDL and LEVONA® leavening agent is greater than the sum of the pressures attained using the GDL and LEVONA® leavening agents individually.
[0059] As discussed above, while not intending to be bound by theory, it is believed that the fast-acting GDL helps acidify and decrease the initial pH of the dough by rapid neutralization of a portion of the sodium bicarbonate, resulting in a lower subsequent pH and thereby increasing the reaction rate of the slower reacting LEVONA® calcium acid pyrophosphate leavening agent. This increased reaction rate results in faster proofing and higher can pressure, resulting in a packaged dough product with excellent shelf life and product properties. The subsequent pH of the dough after the base reacts with the expansion leavening agent, such as GDL, is within the optimal pH range for the calcium acid pyrophosphate leavening agent to react with the base and generate gas within the dough. For a dough containing LEVONA® leavening agent, the pH range for reacting with the base is about pH 6 to about pH 8.
[0060] Although the present invention and it advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the invention described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, the compositions, processes, methods, and steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. | A refrigerated dough system including a dough product contained in a package is described. The dough product includes an unencapsulated base, an unencapsulated expansion leavening acid, and an unencapsulated pressurization leavening acid. The pressurization leavening acid may be a calcium-based leavening acid. This refrigerated dough system makes it possible to achieve or exceed the critical rate of gas evolution for a particular product while improving the nutritional properties of the product. Also described is a method of making a refrigerated dough product. This method involves making a dough from ingredients including an unencapsulated base, an unencapsulated expansion leavening acid, and an unencapsulated pressurization leavening acid. The dough is placed within a package, which is sealed from within by action of the expansion leavening acid and the base. Pressure is then generated inside the package by action of the pressurization leavening acid and the base. | 0 |
BACKGROUND OF THE INVENTION
In comparison with painted road markings, pavement-marking tapes generally offer superior reflectivity, visibility and durability on streets and highways. However, despite superior performance, pavement-marking tapes are not always selected for pavement marking in place of paint.
Independent of differences of material costs between road marking tape and paints, one explanation for not selecting tape is the current lack of suitably efficient equipment for application of large amounts of tape to roadway surfaces during a short span of time. Existing application systems are exemplified by the manual systems taught by Eckman in U.S. Pat. No. 3,350,256, and the semi-automated systems taught by Eigenmann in U.S. Pat. Nos. 3,007,838; 3,155,564; 3,235,436 and 4,565,467. The systems taught by Eigenmann are adapted to cut tape into strips and subsequently apply the tape strips to the roadway surfaces.
The present inventor previously developed a pavement-striping apparatus, disclosed in U.S. Pat. No. 4,030,958 and incorporated herein by reference. The previous apparatus is a trailer type unit. One drawback of a trailer unit is the relatively long time required to align and orient the unit for accurate applications of short lengths of tape. For this reason, a manual application apparatus has often been employed in such situations. The tape application process involving the trailer type apparatus also required a three person crew, one of the crew driving a tow vehicle and one of the crew driving a following vehicle. The third member of the crew typically rides in the tow vehicle and repeatedly returns to the trailer for loading of the apparatus. This necessitates stopping the apparatus to install fresh rolls of tape and splice the tape after application of each roll of pavement marking tape is dispensed.
Another problem encountered with tape applicator devices currently in use is the difficulty in obtaining stability of bond between the tape and the roadway. Although rollers have been employed to further urge the tape against the roadway, the industry has generally relied upon vehicle tires as part of the application process. However, until a stable bond has been achieved, vehicles which stop, start or turn abruptly upon the newly applied tape may dislodge or distort the tape. The usual solution to this problem has been furnishing a following vehicle to drive upon the tape. The following driver (i.e. the second crew member) is instructed to diligently drive the left front wheel of the following vehicle over the tape and to avoid abrupt maneuvers on the tape. In practice, the following driver may fail to accomplish the assigned task, necessitating subsequent costly replacement of poorly secured portions of tape after a very brief service life.
An application apparatus which eliminated the necessity for reliance upon a following vehicle with a diligent, experience crew member to achieve a stable installation and/or allowed for a more rapid overall application rate would be very desirable.
SUMMARY OF THE INVENTION
The present invention includes an apparatus for applying pavement-marking tape to a roadway surface. The apparatus includes a self-propelled, steerable vehicle having a rear wheel and a device attached to the vehicle. The attached device includes a plurality of feed mandrels for rotatably supporting rolls of tape and dispensing tape from the rolls; a mechanism for accumulating a variable length of tape dispensed from one of the mandrels; and a tape deposition mechanism (application head) situated on or adjacent to the roadway surface preceding the rear wheel of the vehicle. The device is preferably mounted inside a truck.
In addition, the present invention includes a method for continuously applying pavement-marking tapes to a roadway surface. The method includes the steps of providing an application device on a forward moving self-propelled vehicle, the device having a tape deposition head situated adjacent a portion of the roadway surface preceding the rear wheel of the vehicle; depositing tape upon the roadway surface and tamping the deposited tape with the rear wheel of the vehicle. The method preferably includes the additional steps of mounting a roll of tape on a mandrel of the device, threading the tape from the roll through an accumulation mechanism and through an application head having a nip, and depositing the tape through the nip to the roadway surface. Forward motion of the vehicle results in the rear wheel traveling over the tape and tamping the tape to the roadway to secure and complete the application. Preferably, the device includes a second mandrel from which a second tape roll may be mounted. The preferred method requires only a momentary delay of the vehicle for splicing a second tape to the first tape, since the second tape roll may be mounted and prepared for splicing during the application of the first roll of tape.
The apparatus and method of the present invention also allows a two person crew to apply the pavement marking tape since the necessity of a following vehicle and a diligent driver for the following vehicle has been eliminated. The apparatus and method of the present invention are suitable for application of tapes on tight radius turns, and the apparatus is more maneuverable than existing trailer type systems.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of a preferred embodiment of the present invention with portions cut-away and portions shown in dotted outline;
FIG. 2 is a side view of the apparatus;
FIG. 3 s a partial side view with portions removed showing parts of the tape deposition mechanism and tape accumulating means;
FIG. 4 is a more detailed side view with portions removed;
FIG. 5 is a sectional view at 5--5 of FIG. 4;
FIG. 6 is a top plan view at 6--6 of FIG. 5;
FIG. 7 is a sectional view at 7--7 of FIG. 5;
FIG. 8 is a detailed end view of the pivot axis portion of the device, looking toward the rear of the apparatus, showing the pivotable accumulator arms, the cam operated valves and the air cylinders;
FIG. 9 is a detailed left side elevation view of the tape deposition mechanism with a raised position shown in dotted outline;
FIG. 10 is a left side elevation view of the tape deposition mechanism during tape cutting;
FIG. 11 is a perspective view showing the pivotal axis of the tape deposition mechanism at 11--11 of FIG. 10; and
FIG. 12 is a schematic diagram of the pneumatic control system for the left tape.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the apparatus of the present invention is shown in FIG. 1 at 20. The apparatus 20 includes a self-propelled steerable vehicle 22. The apparatus 20 also includes a device 24 carried by the vehicle 22. Together, the vehicle 22 and device 24 form an apparatus 20 which is relatively easy to maneuver and is useful to apply pavement marking tapes 74 and 117 to a roadway surface 30. The tapes 74 and 117 may be applied as a continuous stripe 26 or as discontinuous stripe segments 28 each segment being separated from the next segment by an untaped portion 32 on the roadway surface 30.
Preferably, the vehicle 22 is a truck having dual rear wheels and appropriately reinforced springs to handle the weight of the device 24, a load of rolls of tape, and a two person operating team (i.e. a vehicle driver and a device operator). In FIG. 1, outside dual left rear wheel 34 and inside left dual rear wheel 36 are shown in dotted outline. The tapes 26 and 28 on the roadway 30 are applied along the path to be traveled by dual rear wheels 34 and 36. A driver or operator steering the vehicle 22 from within cab 38 may efficiently predict the path to be followed by rear dual wheels 34 and 36 by sighting through a guidance device 42 mounted on the front bumper 44 of vehicle 22. Guidance device 42 includes a combination of a halfsilvered mirror and a lamp which appears to project an illuminated mark upon the roadway surface 30 at point 40. Point 40 is generally on the pathway to be followed by rear dual wheels 34 and 36. A preferred guidance device 42 is a model 2406 collimator sight available from the M-B Co., Inc. of Wisconsin.
As shown in FIG. 2, the vehicle 22 also preferably includes warning lights 46 mounted on top of cab 38 for warning oncoming traffic and a warning board 48 mounted at the rear of the vehicle 22 for warning overtaking traffic approaching from the rear. The vehicle 22 also includes steerable front wheels 50. The vehicle is driven forward along the roadway surface 30 by rear wheel 34, however, an alternative embodiment of an apparatus of the present invention could employ a front wheel drive vehicle. The device 24 is generally enclosed within the rear compartment 52 of the vehicle 22.
The device 24 includes a tape deposition mechanism 54. The tape deposition mechanism 54 is situated adjacent the roadway surface 30 in a position preceding the rear left dual wheel 34 and generally following the left front steerable wheel 50. Because the tape deposition mechanism precedes the rear wheels 34 and 36 on the same vehicle 22, the tapes 26 and 28 are virtually assured of achieving a secure bond to the roadway surface 30 through forward motion of the vehicle 22.
The device 24 further includes an accumulator mechanism 56 capable of accumulating variable lengths of tape for subsequent release to the deposition mechanism 54. The device 24 also includes a plurality of feed mandrels 58 shown in dotted outline which served to dispense tape from rolls of tape to the accumulator mechanism 56. The mandrels 58 are generally designated in FIG. 2, but later in this description will be referred to by individual numbers 72, 110, 114 and 116.
The tape deposition mechanism 54 may be raised for rapid travel of the vehicle 22 of the apparatus 20 at typical highway traffic speeds. The rear compartment 52 of the vehicle includes a large aperture 60 for accessing in maintenance of the device 24. The aperture 60 may be covered by a panel made of canvas, plastic or metal (not shown) to further protect the device 24 and any on board supplies of tape during high speed travel or exposure to inclement weather.
As shown in FIG. 3, the device 24 includes a frame system 57 to carry the tape deposition mechanism 54, the accumulator mechanism 56 and the feed mandrels 58. The frame system 57 attaches to the vehicle 22 and facilitates removal of the device 24 from the vehicle 22 in order to free the vehicle 22 for alternative service uses. Optionally, the frame system 57 might be an integral and nonremovable part of the vehicle 22.
The device 24 is capable of applying two strips of tape 26 and 28 to the roadway surface 30. The system for a single tape, specifically the left tape 26, will be described first.
The left most tape strip 26 begins as a roll 70 rotatably supported upon a feed mandrel 72 of a plurality of mandrels 58. The web 74 from the roll 70 travels over a first idler roller 76 located generally above the plurality of feed mandrels 58, then forward to a second idler roller 78 located generally above the accumulator mechanism 56. From the second idler roller 78, the tape travels in a serpentine path, generally downward through the accumulator mechanism 56. The portion of the accumulator mechanism 56 responsible for the tape web 74 includes a stationary arm 80 and a pivotable arm 82. Pivotable arm 82 is rotatably supported at the upper end by a pivot axis 84 laterally supported by frame system 57. Pivotable arm 82 can swing forward and rearward about pivot axis 84 approximately 60° relative to stationary arm 80, which is also supported at the upper end by the pivot axis 84.
The stationary arm 80 carries four spaced apart accumulator rollers: an upper or first roller 86 (adjacent pivot axis 84), a second roller 88, a third roller 90, and a lower or fourth roller 92. Pivotable arm 82 carries three spaced apart accumulator rollers: an upper or first roller 94 (adjacent the pivot access 84), a middle or second roller 96, and lower or third roller 98 (adjacent to the lower end of the pivotable arm 82).
The tape web 74 is threaded through the accumulator mechanism 56 and progresses downward from the second idler roller 78 to the upper roller 86 of the stationary arm 80; thence to the upper accumulator roller 94 of the pivotable arm 82; thence to the second accumulator roller 88 of the stationary arm 80; thence to the middle accumulator roller 96 of pivotable arm 82; thence to the third accumulator roller 90 of the stationary arm 80; thence to the third and lowest accumulator arm 98 of the pivotable arm 82; thence to the lowest accumulator roller 92 of the stationary arm 80.
From the fourth accumulator roller 92 of the stationary arm 80 the tape web 74 travels over a third idle roller 100 attached to the floor of the rear compartment 52 (as shown in FIG. 5) at a position generally below the pivotable arm 82 for release to the deposition mechanism 54.
From the third idler roller 100, the tape web 74 precedes to a fourth idler roller 102 on the tape deposition mechanism 54. The tape 74 is then threaded over a keeper roller 104 and under an engagement roller 106. The engagement roller 106 forms a nip 107 with the roadway surface 30 and places the adhesive side of the tape 74 against the roadway surface 30. Next, the tape 74 travels under a preliminary pressure roller 108. Finally, the tape 74 goes under the left most dual rear wheel 34 which serves to firmly secure the tape 74 to the roadway surface 30 thus forming tape stripe 26.
A second mandrel 110 is mounted on the device 24 aligned with and immediately rearward of mandrel 72. The second mandrel 110 carries a spare roll of tape 112 which may also dispense tape over the first idler roller 76.
The device 24 of the preferred embodiment 20 also includes a second system for applying a right side tape stripe 28. The first (left side) system is essentially duplicated in the second (right side) system which is generally situated immediately to the right of the first system. The mandrels 114 and 116 of this second system can each carry a roll of tape and can, with substantially equal facility, dispense or feed tape 117 over a first idler roller 118, thence to a second idler roller 120 and into the accumulator system 56, and continue through to the tape deposition mechanism 54 for securing by the inner dual rear wheel 36 (previously shown in FIG. 1). The second accumulator mechanism also includes a stationary arm 122 carrying four spaced apart accumulator rollers: an upper or first roller 124, a second roller 126, a third roller 128, and a lower or fourth roller 130, and a second pivotable arm 132 having three accumulator rollers: an upper or first roller 134, a middle or second roller 136, and a lower or third roller 138. In the second system the tape threading and travel essentially duplicate the first system.
When the pivotable accumulator arm 82 or 132 of the accumulator 56 achieves the maximum angle of 60° relative to the stationary arm, 80 or 122 respectively, a serpentine path of maximum length, in one embodiment approximately 8 feet 5 inches (257 cm), is provided. Alternatively, when the pivotable accumulator arm 82 or 132 achieve an angle of 0° relative to the stationary accumulator arm, 80 or 122 respectively, a serpentine path of minimum length, in one embodiment approximately 30 inches (76 cm), is provided. The variation in path length provided by the accumulator mechanism 56 allows for temporary compensation of differences between tape deposition rates (i.e. deposition rates corresponding to the forward speed of the vehicle 22 along the roadway surface 30) and dispensing rates of tape 74 from a roll (such as roll 70 on a mandrel 72). Such a temporary differential occurs during two different functions of the device 24.
First, tape deposition is initiated while the vehicle 22 is already under forward motion at rates of from approximately 5 to approximately 10 miles per hour (8 to 16 kilometers per hour). It would be extremely difficult, if not impossible, to nearly instantaneously accelerate a roll 70 from nonrotation to a sufficient rate of rotation to match the ground speed. Without the accumulator mechanism 56, the initially deposited tape would either not engage the roadway surface 30 firmly, or alternatively, would snap somewhere in the web from the sudden excess tension. The accumulator mechanism 56 accommodates the initiation of tape deposition by rapidly reducing the serpentine path length, thereby rapidly releasing tape 74 and allowing the tape roll 70 to gradually begin to rotate and dispense tape 74.
Second, at the termination of tape deposition, the leading edge of the tape 74 must stop abruptly, whereas the rapidly spinning roll 70 tends to continue spinning and dispense excessive tape 74. The accumulator mechanism 56 accommodates the termination of tape deposition by rapidly increasing the serpentine path length, thereby rapidly accepting tape dispensed from the tape roll 70 and allowing the roll 70 to gradually stop.
Using two mandrels for each application system, an operator working within the rear compartment 52 can load and prepare one mandrel while the tape material is being dispensed from the other mandrel. Assuming an experienced operator, the ability to load and prepare the tape rolls for splicing while the vehicle 22 is in motion significantly reduces the delay of tape application between rolls from about 40 seconds (typical of existing systems) to less than about 5 seconds.
The accumulator mechanism 56 includes controlled biasing of the pivotable arms 82 and 132 to enable increasing or decreasing of the serpentine path length. As above, since the two tape systems are essential duplicates, the detailed operation need only be described for the outer most system.
The pivotable arm 82, as shown in FIG. 4, is attached at its upper rear edge to a helical tension spring 150 through a cable 152 and a pulley 154. The tension spring 150 is attached at its opposite end to the frame system 57. Preferably, the spring 150 and cable 152 are adjustable in length and therefore in tension. The spring 150 and cable 152 bias and urge the pivotable arm 82 to its fullest angular position relative to the stationary arm 80. As explained earlier, this position corresponds to a maximum serpentine path length.
A double acting pneumatic piston 156 is also attached at a first end to the pivotable arm 82 and to the frame system 57 at a second end. Retraction of the piston 156 forces the pivotable arm 82 toward the stationary arm 80, thereby decreasing the serpentine path length. Extension of the piston 156 forces the pivotable arm 82 away from the stationary arm 80 and thereby increases the serpentine path length.
The piston 156 is actuated to extend or retract by a fluid connection to a pneumatic pressure source. A schematic diagram of the pneumatic controls for the left tape 74 is shown in FIG. 12. The right tape 117 is controlled by substantial duplicate of the pneumatic controls for the left tape 74. Specifically, a compressed gas cylinder 250 is connected to a first pressure regulator 252. Preferably, the compressed gas cylinder 250 contains nitrogen gas. However, other nontoxic gases or gas mixtures such as air may be employed. Alternatively, an air compressor may be employed. The first regulator 252 reduces the high pressure nitrogen (up to about 2500 psi (17.2 MPa)) to a working pressure of about 100 psi (690 KPa). The working gas pressure is connected to a distribution block 254. Preferably, the pressure cylinder 250, first regulator 252, and distribution block 254 are shared by the pneumatic controls for the second tape 117 system.
From the distribution block 254, the working gas pressure is connected to a second adjustable regulator 256 which provides pressure of, for example, about 50 psi (345 KPa) to a first port 258 of a four-way solenoid valve 260. A second port 262 of the four-way solenoid valve 260 is connected to the upper port 264 of the piston 156. Application of pneumatic pressure to the upper port 264 of piston 156 results in extension of the piston 156 and thereby increases the serpentine path length of tape 74.
A third port 266 of the four-way solenoid valve is connected to a third adjustable pressure regulator 268 which in turn is connected to the lower port 270 of the piston 156. Application of pneumatic pressure to the lower port 270 results in retraction of the piston 156 and thereby decreases the serpentine path length. The remaining fourth port 272 of the four-way solenoid valve 260 serves as an exhaust. The second pressure regulator 256 serves to reduce the pressure of the compressed gas to a pressure P 1 which is the pressure supplied to the upper (extension actuating) port 264 of piston 156. The third pressure regulator 268 serves to potentially further reduce the pressure of the compressed gas to a pressure P 2 which is equal to or less than P 1 and which is supplied to the lower (retraction actuating) port 270. Typical pressures P 2 are, for example, about 140-210 KPa.
The two functions of the four-way solenoid valve 260 are as follows: In a first mode; the four-way solenoid valve 260 connects the upper (extension actuating) port 264 of piston 156 to compressed gas at pressure P 1 and simultaneously connects the lower (retraction actuating) port 270 of piston 156 to the exhaust port 272 of the four-way solenoid valve 260 (and thereby releases any retraction pressure). In a second mode; the four-way solenoid valve 260 connects the lower (retraction actuating) port 270 of piston 156 to compressed gas at pressure P 2 and simultaneously connects the upper (extension actuating) port 264 of piston 156 to the exhaust port 270 of the four-way solenoid valve 260 (and thereby releases any extension pressure). A preferred valve is a solenoid pilot valve such as a Skinner V935LEH2100 12 V.D.C. available from the J. E. Braas Company of Minneapolis, Minn.
In summary, the double acting piston 156 provides retraction at a lower force level and extension at a relatively higher force level. Selection of retraction or extension is by means of a solenoid 260. Preferably, the second pressure regulator 256 is adjusted to provide compressed gas at a relatively high pressure P 1 to extend the piston 156. Extension of the piston 156, in concert with the force provided by tension spring 150 serves to strongly drive pivotable arm 82 away from stationary arm 80. In contrast, retraction of piston 156 works against or roughly balances the opposite force provided by spring 150. Preferably, the third regulator 268 is adjusted to provide compressed gas (at a relatively low pressure P 2 ) so as to closely balance the force of spring 150.
The ability to individually adjust the two pressures, P 1 and P 2 , supplied to piston 156 allows an operator to adjust and finely tune the device 24 to substantially avoid stretching or breaking of tape 74 during initiation of application and accumulate any excess tape 74 dispensed at the termination of application. Further, the ability to individually adjust the two pressures P 1 and P 2 , allows an operator to adapt the device 24 to a wide variety of road marking tapes and application conditions.
The solenoids are controlled by a timing mechanism previously disclosed in U.S. Pat. No. 4,030,958, which is incorporated by reference herein. The timing mechanism senses travel of the apparatus 20 along the roadway surface 30 through optical detection of rotation of the preliminary pressing roller 108. A preferred digitizer is a Rotopulser brand digitizer such as a type 62 AAEF-0200-A-0-00 available from the Dynapar Corporation of Gurnee, Ill.
As shown in FIG. 6, the mandrels 72, 110 and 114 are provided with pneumatically operated disc brakes 158, 160, and 162, respectively. A similar arrangement for mandrel 116 is not shown. The mandrels 72, 110, 114 and 116 each also include three radially spaced teeth (not shown) (which serve to grip the cardboard hub of each tape roll) as well as a detachable quick-release cap for locking the tape roll to the mandrels and transferring any braking force to the roll.
As shown in FIG. 8, projecting upward from the pivotable accumulator arm 82 is a cam 170. The cam 170 acts upon a cam follower 171 on a piston 172 of a variable pressure pneumatic regulator 174. The variable pressure pneumatic regulator 174 provides pneumatic pressure to disc brakes 158 and 160 controlling the rotation of the feed mandrels 72 and 110. Specifically, gas from the distribution block 254 of FIG. 12 is also routed to the variable pressure regulator 174. Output gas, at variable pressures from 0-100 psi (690 KPa) is then routed to both disc brakes 158 and 160. Together, the cam 170 and variable pressure regulator 174 function such that when the angle between the pivotable arm 82 and the stationary arm 80 is from preferably about 0° to about 15°, no pneumatic pressure is supplied to the disc brakes 158 and 160, and the mandrels 72 and 110 are free to rotate. A preferred variable regulator 174 is a Command Air brand pneumatic control valve mode F 05118016 available from the Schrader Bellows Company. This particular valve provides high pressure when the piston 172 is in a retracted position and no pressure when the piston 172 is extended.
From preferably about 15° to about 45° of angle between the pivotable arm 82 and the stationary arm 80, the pneumatic pressure to the disc brakes 158 and 160 of the mandrels 72 and 110 is progressively increased and rotation of the mandrels 72 and 110 is progressively inhibited. From preferably about 45° to about 60° of angle between the pivotable arm 82 and the stationary arm 80, maximum braking pressure is applied to the disc brakes 158 and 160 to prevent or nearly prevent rotation of the mandrels 72 and 110.
In this way, overspinning of the tape rolls 70 and 112 is progressively inhibited as the accumulator mechanism 56 reaches its maximum capacity of serpentine path length. Conversely, the tape rolls 70 and 112 are completely freed to rotate and thereby dispense tape as the accumulator pathway is shortened and approaches a shortage of tape for release to the tape deposition mechanism 54.
The tape deposition mechanism 54 is connected to the frame system 57 at pivot point 190 as shown in FIG. 4 and FIG. 9. A hydraulic ram 192 allows the deposition mechanism 54 to be lifted off the ground. For high-speed transportation, a chain support (not shown) is used to support the tape deposition mechanism 54 thereby relieving the load on the hydraulic ram 192 and avoiding possible damage.
Constant contact of the preliminary pressing roller 108 is essential to the application process since rotation of the preliminary pressing roller 108 provides detection of the distance traveled on the roadway surface 30 to the timing mechanism controlling the various solenoids of the device 24. Additionally, the engagement rollers 106 are parallel to the preliminary pressing rollers 108, and may possibly fail to form an acceptable nip 107 with the roadway surface 30. To allow better contact of the preliminary pressing rollers 108 to the roadway surface 30 during tape application, the deposition mechanism 54 has limited rotation about two separate axes. The first axis corresponds to pivot point 190 and allows for rotational motion about a leading transverse axis 190. Effectively, limited up and down motion is accommodated.
The second axis is a longitudinal axis at a pivot 191 between a forward carriage 193 and a rearward carriage 195 as shown in FIG. 11. Specifically, the forward carriage 193 has pivot (e.g. bolt) 191 projecting longitudinally rearward from its lower rear edge and into a pivot bore in the lower forward edge of the rearward carriage 195. Additionally, the forward carriage 193 also includes bores for four guide bolts 194 projecting longitudinally rearward. The rearward carriage 195 has four arcuate slots 196 to accept guide bolts 194. The specific curved patterns of arcuate slots 196 are circumferential about pivot 191. Together, the longitudinal pivot 191 and arcuate slots 196 enable a limited rotation of the rearward carriage 195 of about ±4° either direction from horizontal.
A tape cutter 200 has a blade 202 which shares a common rotation axis with engagement roller 106. A helical tension spring 205, as shown in FIG. 10, typically holds the tape cutter 200 against a metal strut 204 which is rigidly mounted on the rearward carriage 195.
FIG. 10 shows the disposition of the tape deposition mechanism 54 immediately prior to initiation of tape application. The keeper roller 104 and the engagement roller 106 are carried in a frame 206. The frame 206 also is carried by the axle of the preliminary pressure roller 108 which in turn is mounted on the rear carriage 195. The frame 206 is further connected to a leg 208 which in turn is connected to a beam 210 at pivot 212. The beam 210 is also connected to the rearward carriage 195 at pivot 214. A double acting pneumatic piston 216, connected between the rearward carriage 195 and the beam 210, lifts (in retracted mode) the leg 208 and causes the frame 206 to pivot upward about the axle of the preliminary pressure roller 108. The upward pivoting of the frame 206 forces the keeper roller 104 toward a stop member 218, thereby trapping the tape 74. Preferably, the stop member 218 is formed of hard rubber and is mounted on the underside of rearward carriage 195.
During initiation of tape application, the piston 216 is actuated through a four-way solenoid valve 280, of FIG. 12, to move the beam 210, leg 208, and frame 206 in a downward direction. Specifically, the valve serves to provide two modes of connections: First, the valve connects the retraction port 282 of the piston 216 to the source of pressurized gas from regulator 278 and simultaneously connects the extension port 284 of the piston 216 to an exhaust port 286 of the four-way valve 280. Alternatively, second, the valve 280 connects the extension port 284 of the piston 216 to the source of pressurized gas from regulator 278 and simultaneously connects the retraction port 282 of the piston 216 to the exhaust port 286 of the valve 280. Preferably the gas supply pressure to the valve 280 is moderated by the pressure regulator 278 to pressures from about 40 to about 85 psi (280-590 KPa). The higher pressures are employed for tapes 74 which are more difficult to sever.
The pneumatic piston 216 may be connected to any one of three mounting holes 213 which have been drilled through the beam 210 to provide faster or slower cutter speeds, depending on the type of tape which is to be applied.
When the piston 216 is actuated to extend, the frame 206 moves rapidly and forcefully from the position shown in FIG. 10 to the position shown in FIG. 9, thereby pressing the leading edge of the tape 74 at the nip 107 into engagement against the roadway surface 30. After the tape 74 has been applied to the roadway surface 30, it is first preliminarily pressed down by roller 108, then pressed or tamped upon by the rear wheel 34 of the vehicle 22 to more firmly secure the tape to the roadway surface.
After a stripe 26 of desired length of tape 74 has been applied to the roadway surface, the solenoid valve 280 is operated to supply pressure to retract the pneumatic piston 216, and thereby to pivotably raise the frame 206 to the disposition shown in FIG. 10.
During upward movement of the frame 206, the back side of cutter 200 contacts the strut 204 causing the cutter 200 to pivot. The strut 204 initially contacts the cutter 200 well away from the pivot axis of the cutter 200 but the contact between the strut 204 and the cutter 200 shifts progressively nearer to the pivot axis. Because the motion of the frame 206 is rapid and forceful, the cutter 200 is progressively accelerated, gains momentum, and continues to pivot about the axis when the keeper roller 104 traps the tape 74 against the hard rubber stop 218. This motion continues until cutting edge 202 (preferably a serrated cutting edge) contacts and severs the web of tape 74 extending between the roadway surface 30 and the engagement roller 106. The tape 74 is held taut between the engagement roller 106 and the preliminary pressure roller 108 during the tape cutting operation. In a preferred embodiment, the hard rubber stop 218 is connected to the rearward carriage 195 and acts as a shock absorber to cushion the impact of the engagement roller 106 and the keeper roller 104 with the stop 218.
To assure the end of the tape 74 threads under the engagement roller 106 and into the nip 107 during initiation of tape application between applications, the tape deposition mechanism 54 is further provided with a copper tube 220. The tube 220 is connected to the exhaust port of four-way valve 280 associated with the pneumatic piston 216 at a first end and is positioned so that its second end 222 is directed toward the engagement roller 106. The copper tube 220 provides an appropriately timed surge of pressurized gas from the tube end 222 against the end of tape 74 to direct the end of the tape 74 into the nip 107 being formed. The useful pneumatic surge of pressurized gas provided to the tube 220 is from the exhaust of the pneumatic piston 216 coinciding with a drop of the frame 206 to the ground-engaging position from which the tape 74 will be deposited. The surge of pressurized gas serves to move the end of tape 74 under the engagement roller 106 immediately prior to formation of the nip 107 and assures that the tape 74 will effectively be oriented for engagement and subsequent pressing by wheel 34. The surge is efficiently provided at the proper timing in the application sequence and is a second use of the pressurized gas which previously raised the frame 206.
Prior to the initiation of application of tape 74 in the manner described, the accumulator pivotable arm 82 is arranged such that it forms an angle of about 60° with respect to the stationary arm 80. The pivotable arm 82 is held in this extended position partially by the tension spring 150, shown in FIG. 4. Additional force is applied to urge the pivotable arm 82 to this position by the piston 156.
As previously explained the piston 156 is a two-way piston, that is, it can be actuated to retract or extend by the application of pressure to alternative ports of its cylinder, and thereby operated to either push or pull. At the initiation of a tape application event, the retraction port 270 of the piston 156 receives pneumatic pressure P2 from the third regulator 268. The application of pneumatic pressure to retract the piston 156 slightly relaxes or over balances the tension from spring 150 on the accumulator pivotable arm 82.
Preferably, the balancing of forces at this time is such that manual force will rotate the accumulator pivotable arm 82 from the extended (60°) position toward the stationary arm 80 to release tape 74 for application. The balancing and relaxation of pressure on pivotable arm 82 eases movement of tape 74 when the engagement roller 106 is subsequently pressed toward roadway surface 30 to form nip 107. This, in turn, engages the tape 74 to the roadway surface 30. Engagement of tape 74 and roadway surface 30 at that time results in tension being suddenly and strongly applied on the tape 74.
As application of tape 74 continues, the combination of the force being applied on the tape as it is drawn out into the roadway surface 30 and the inertia in the mandrel 72 and tape roll 70 causes the accumulator pivotable arm 82 to move toward the stationary arm 80 (i.e. toward the empty (0°) position), thereby shortening the serpentine path length. As tape application continues, tension gradually increases at the roll of tape 70 which, in turn, begins to rotate, dispensing tape 74 rapidly through the accumulator 56 for deposition onto the roadway surface 30.
At termination of deposition, the tape 74 is trapped and cut in the deposition mechanism 54. The pneumatic pressure to the double acting piston 156 is reversed (i.e. pressured gas is applied at port 264), forcing the pivotable arm 82 away from the stationary arm 80. As the pivotable arm 82 swings rearward, the serpentine path length increases and the cam 170 causes the disc brakes 158 and 160 to slow and stop the rotation of mandrel 72 and slow and stop dispensing of tape 74.
Various types of road marking tapes are available, and these may be applied using the method and apparatus of the present invention. In a preferred method, the tape 74 carries a pressure-sensitive adhesive, or an adhesive may have been applied to the roadway by other means, so that the tape 74 adheres to the roadway surface 30. When the tape 74 carries a pressure-sensitive adhesive on one side, the rollers of the device described above which contact the adhesive side of the tape 74 are preferably knurled to reduce adhesion of the tape 74 to these rollers. Specifically, for adhesive tapes rolled with the adhesive side directed toward the center of the roll 72, rollers 76, 78, 94, 96, 98, 100, and 104 should be knurled. The rollers contacting the top side of tape 74 (i.e. side intended to face upward when applied to the roadway) should preferably have a smooth surface.
Another feature of the present invention is that the apparatus 20 can be stocked with large supplies of rolls of tapes to be applied to the roadway surface 30. Using the dual mandrel system 58 described above, new rolls of tapes can be loaded into the second mandrel 110 while a first roll 70 is being dispensed from the first mandrel 72 and applied to the roadway surface 30. Just before the first roll 70 of tape runs out, an operator can prepare to splice the leading edge of the second roll of tape to the trailing edge of the first tape. The splicing operation can be performed with a brief stop of 5 seconds or less. After the tape ends have been spliced together (e.g. with double sided adhesive tape, preferably including a nylon web), forward progress of the apparatus 20 is resumed and the tape 74 is then dispensed from the second mandrel 110. The operator can subsequently replace the empty reel of the first mandrel 72 with a full roll of tape. The roll change and splicing steps can be repeated until the supply of tape aboard the vehicle 22 is depleted or until the tape application operation is completed.
Because the present invention is a single vehicle (preferably enclosed) rather than a trailer, it provides added safety to the tape application operation. Specifically, the apparatus 20 eliminates the need for a crew member to return to a trailer by walking on the roadway at each roll change. In other words, it is an advantageous safety feature of the present invention that the entire tape application device 24 can be contained within an enclosed vehicle 22 so that the operator can perform all of the described steps without exiting the vehicle 22 and thereby avoiding exposure to potentially hazardous traffic.
Having fully described the preferred embodiments of the invention, it should be understood that numerous alternatives and equivalents which do not depart from the present invention will be apparent to those skilled in the art, given the teaching herein, and are intended to be included within the scope of the present invention. The invention is not to be unduly limited by the aforementioned descriptions. | Method and apparatus are disclosed for automatically applying pavement marking tape to roadway surfaces using a self-propelled vehicle. Tapes can be applied in continuous stripes or intermittent stripes of variable spacing or length while the vehicle is in motion. Methods are also disclosed for changing rolls of tapes while the vehicle is in motion, and thereby reducing stopping times for splicing. The tape application mechanism can be enclosed within the vehicle so that the operator is protected from traffic hazards. | 4 |
FIELD OF THE INVENTION
The invention relates to push-to-talk communication networks.
BACKGROUND
Push-to-talk (PTT) communication is half duplex communication over a network configured to support communication between members of a group of users of the network in which each of the group can acquire exclusive status as a “sender” and transmit information in a multicast mode to all the others in the group. For convenience of presentation, a period of time during which the PTT communication takes place is referred to as a PTT session. A communication network or portion thereof configured to support a PTT session and participants of the session, are referred to as a PTT network and comprises at least two participants and generally more than two participants.
When a given participant of a PTT session has active status as a sender, the other participants of the PTT session are referred to as “listeners”. Status as a sender during the session may generally be acquired by any of the PTT session participants at any time when no participant in the session is a sender by appropriately signaling the network. Once acquired, sender status is maintained until relinquished. Signaling to acquire sender status is obtained and maintained by appropriately operating a communication device configured to support PTT communication over the network. Usually, the communication device comprises a button, hereinafter a “PTT button”, which a participant of the PTT session depresses to signal desire to acquire sender status, and maintains depressed to maintain sender status.
PTT communications using cellular mobile phones, conventionally known as Push-to-talk over cellular (PoC), is half duplex communication during a PTT session over a cellular phone network between participants, equipped with cellular phones, hereinafter “PoC phones”, that are configured to provide, in addition to regular cellular phone communication, PTT communication over the cellular network. A cellular phone network or portion thereof configured to support a PTT session and participants of the session, are referred to as a PoC network and comprises at least two participants and generally more than two participants. The acronyms PoC and PTT may be used interchangeably hereinafter.
Typical of PoC communication, a participant becomes a sender, by merely pressing a PTT button on his or her PoC phone and acquires exclusive ability to transmit information, generally a voice message encoded in a suitable format for transmission, in a multicast mode to all the other participants of the PoC network. While a sender is transmitting, i.e. as long as the sender maintains his or her PTT button depressed, all the other PoC participants have status as listeners and cannot interrupt or transmit information to the sender or any of the other participants. A given sender relinquishes exclusive status as a sender when the sender releases his or her PTT button, thereby ending the given sender's transmission. After the given sender's transmission is ended, a first participant to press the PTT button on his or her mobile PoC phone acquires status as a sender with exclusive ability to transmit to all the other participants of the PTT session. This form of one-way half-duplex communication, contrasts with full-duplex communication, typical of cellular mobile communication and most forms of telephone communication, in which both the sender and the listener are able to transmit information to one another, or a third party, simultaneously.
In a typical PoC environment, all the participants in a PTT session use PoC phones equipped with a same type of CODEC (encoder/decoder) adapted to operate using a same voice encoding/decoding format. When a participant is a sender, the CODEC in the sender's PoC phone converts the sender's voice into signals, hereinafter “PTT signals”, having a format, hereinafter a “PTT format”, suitable for transmission over the PoC network. The CODEC in a listener's PoC phone that receives the senders PTT signals translates the PTT format back into voice.
Nevertheless, there may be PoC situations in which a sender and a listener are equipped with PoC phones comprising different types of CODECs, i.e. CODECs configured to use different types of coding/decoding PTT formats, so that the listener's PoC phone, also referred to as a receiver, does not “understand” the PTT format transmitted by the sender's PoC phone. As a result, the receiver is unable to translate the received PTT format into voice. Such situations can arise for example, when participants subscribing to different PoC network operators attempt to communicate in a PTT mode with each other.
To deal with such situations, some PoC networks have a network infrastructure comprising transcoders. The transcoders generally comprise relatively large Digital Signal Processing (DSP) equipment located at network gateways (communication exchange terminals), and are adapted to convert a PTT format used by a first CODEC into a different type of PTT format used by a second CODEC. A drawback to this approach is cost associated with using DSPs, which can be substantial for PoC networks involving large numbers of participants. Another approach is to fit a plurality of CODECs into participants' PoC phones, each CODEC capable of encoding/decoding a PTT format used by a different PoC network operator. Here again, the cost of fitting multiple CODECs in PoC phones for a large number of participants can be substantial.
Another approach to providing PTT communication between PoC phones equipped with different CODECs involves configuring the PoC phones with multiple decoders compatible with the different voice encoding formats of the different CODECs. Each such PoC phone comprises a single encoder and multiple decoders. Although it is generally less expensive to implement multiple decoders in the handsets rather than a plurality of “complete” CODECs, such a solution can also be expensive.
US Patent Publication 2006/0034260 A1, “Interoperability for Wireless User Devices with Different Speech Processing Formats,” the disclosure of which is incorporated herein by reference, describes providing interoperability between wireless user devices using different CODECs. Interoperability is achieved by equipping communication devices with a plurality of decoders, each capable of decoding a different speech encoding format.
US Patent Publication 2006/0120350 A1, “Method and Apparatus Voice Transcoding in a VoIP Environment,” the disclosure of which is incorporated herein by reference, describes a method for voice transcoding in a voice-over-internet-protocol (VoIP) environment comprising: receiving packets that include vocoder data frames in which source voice samples have been encoded according to a first vocoding format; decoding, by a decoder, the vocoder data frames to produce a sequence of linear speech samples; obtaining, by an encoder via a non-circuit switched communication path, linear speech samples from the sequence of linear speech samples produced by the decoder; and encoding, by the encoder, groups of speech samples from the sequence of linear speech samples to produce vocoder data frames according to a second vocoding format.
SUMMARY
An aspect of some embodiments of the invention relates to providing a method and a system for a relatively simple, improved configuration for providing push-to-talk (PTT) multicast communication using communication devices such as, for example, cellular mobile phones, that operate using different CODECS.
For convenience of presentation, one or more communication devices, and/or their users, using a same CODEC and configured to “participate” in a same PTT session using the CODEC are referred to as a PTT multicast group (PMG). A PTT session is a PTT communication session in which PTT communication devices of one or more PMGs communicate with each other, each different PMG having a different CODEC. Each communication device configured to participate in a PTT session is referred to as a PTT device.
In accordance with an aspect of an embodiment of the invention, a Virtual PTT Multicast Group (VPMG), provides PTT communication between PTT devices belonging to PMGs using different CODECs.
In accordance with an embodiment of the invention, the VPMG includes a virtual member associated with each PMG participating in the PTT session. The virtual members are configured to communicate with each other in a PTT mode using a same PTT format, hereinafter also referred to as a “VPMG format”. A virtual member associated with a given PMG also communicates with all participants in its associated PMG in the PTT format peculiar to the associated PMG. Each virtual member comprises a transceiver or transcoder that receives voice signals from its associated PMG encoded in the PTT format of the CODEC of the associated PMG and retransmits the received encoded voice in the VPMG format to the other virtual members. The given virtual member also receives from other virtual members voice encoded in the VPMG format and retransmits the received encoded voice to its associated PMG in the PTT format of the CODEC of its associated PMG.
As a result of configuring a PTT session between participants having different CODECS by the implementation of a VPMG in accordance with an embodiment of the invention, a smaller number of transcoders, than are typically used in prior art are used to support the PTT communications. Optionally a single transcoder is used for each different CODEC in the PTT session. For example, to support a PoC session having 100 participants using three different CODECS, optionally only three transcoders are used.
It is noted that whereas the above discussion refers to transmission of voice signals over a PTT network, the invention is not limited to voice transmission and may includes any data formatted for transmission over the network. For example, in some embodiments of the invention SMSs and or multimedia streams are transmitted between participants of a PTT session in different PMGs. Furthermore, whereas participants in a PTT session in accordance with an embodiment of the invention are generally assumed to be operated by humans, participants may be unmanned automatic communication devices that communicate among themselves in a PTT mode.
There is therefore provided, in accordance with an embodiment of the invention, a communication system comprising: at least one first communication device configured to communicate in half duplex mode using a first encoding-decoding format; at least one second communication device configured to communicate in half duplex mode using a second encoding-decoding format; a third communication device configured to communicate in half duplex mode using the first format; a fourth communication device configured to communicate in half duplex mode using the second format; wherein the third and fourth communication devices are configured to communicate with each other in half duplex mode using a third encoding decoding format.
In some embodiments of the invention, at least one first communication device comprises a plurality of communication devices. In some embodiments of the invention the at least one second communication device comprises a plurality of communication devices.
In some embodiments of the invention, the at least one first communication device comprises a communication device configured to operate in a push to talk mode. In accordance with some embodiments of the invention, the at least one second communication device comprises a communication device configured to operate in a push to talk mode. In some embodiments of the invention, the third and fourth communication devices comprise communication devices configured to operate in a push to talk mode.
In some embodiments of the invention the at least one first communication device comprises at least one cell phone. According to some embodiments of the invention, the at least one second communication device comprises at least one cell phone. In some embodiments of the invention, the third and fourth communication devices comprise at least one cell phone.
BRIEF DESCRIPTION OF FIGURES
Examples illustrative of embodiments of the invention are described below with reference to figures attached hereto. In the figures, identical structures, elements or parts that appear in more than one figure are generally labeled with a same numeral in all the figures in which they appear. Dimensions of components and features shown in the figures are generally chosen for convenience and clarity of presentation and are not necessarily shown to scale. The figures are listed below.
FIG. 1 schematically shows an exemplary Push-To-Talk (PTT) session comprising a virtual push to talk multicast group (VPMG) for use in PTT over cellular (PoC) applications, in accordance with an embodiment of the invention; and
FIG. 2 schematically shows the VPMG comprised in the PTT network shown in FIG. 1 providing communication between participants in a PoC communication session, in accordance with an embodiment of the invention.
FIG. 3 schematically shows a PTT communication network 200 comprising nested VPMGs in accordance with an embodiment of the invention.
DETAILED DESCRIPTION OF EMBODIMENTS
Reference is made to FIG. 1 , which schematically shows an exemplary Push-To-Talk (PTT) network 100 for use in Push-To-Talk communication, in accordance with an embodiment of the invention. Push-To-Talk (PTT) network 100 is optionally a Push-To-Talk over cellular (PoC) network.
Exemplary PTT network 100 , includes a plurality of “N” PTT Multicast Groups denoted PMG- 1 , PMG- 2 , PMG- 3 . . . PMG-N comprising CODECs CODEC- 1 , CODEC- 2 , CODEC- 3 . . . CODEC-N respectively. The PMG groups are referred to generically as PMGs 110 and the various CODECs are referred to generically as CODECs 120 . Different CODECs 120 , for example CODEC- 1 and CODEC- 2 use different coding/decoding schemes.
Each PMG of the plurality of PMGs 110 , for example PMG- 1 , includes one or more PTT participants (not shown). Each participant in a same PMG 110 has a PTT communication device such as, for example, a cellular mobile handset, adapted for PTT communication comprising a same CODEC 120 peculiar to the PMG for encoding and decoding audio signals. Since all participants in a same PMG 110 use a same CODEC 120 , they communicate with one another without having to translate, for example using a suitable transcoder, voice encoded in one CODEC format to voice encoded in a different CODEC format. However, since participants in different PMGs 110 use different CODECs 120 , participants in one PMG 110 cannot communicate directly with participants belonging to a different PMG 110 . It is noted, that whereas PTT participants in PMGs 110 are described as comprising a communication device, which is a cellular mobile phone, a PTT participant may of course use any communication device adapted for PTT communication and having a CODEC 120 for coding and decoding audio signals.
To provide for PTT communication, “cross-PMG communication”, between participants in different PMGs 110 , network 100 comprises a virtual PTT multicast group, VPMG 130 , in accordance with an embodiment of the invention. VPMG 130 comprises a plurality of N virtual members (VMs) 140 , individually distinguished by alphanumeric VM- 1 , VM- 2 , VM- 3 . . . VM-N, one different virtual member VM 140 associated with each PMG 110 . For example, VMs VM- 1 , VM- 2 , VM- 3 . . . VM-N are associated respectively with PMG- 1 , PMG- 2 , PMG- 3 . . . PMG-N. Virtual members VM 140 communicate with each other in a PTT mode using a common VPMG CODEC 149 for encoding and decoding transmissions in a common VPMG format. The common VPMG format is indicated by double arrowhead lines labeled 150 that connect VMs 140 . VPMG format 150 may, for example, be a PTT format defined by the International Telecommunication Union (ITU-T) Standard such as G.711 or G.729, or defined by any other suitable communication protocol.
Each VM 140 in VPMG 130 comprises apparatus, such as an appropriate transceiver and/or transcoder, adapted to receive voice encoded in the format of the CODEC 120 of its corresponding associated PMG 110 and to retransmit the received encoded voice encoded by CODEC 149 in the common VPMG format 150 to other VMs 140 in VPMG 130 . Each VM 140 is also adapted to receive from the other VMs 140 in VPMG 130 , voice encoded in VPMG format 150 and to retransmit, using suitable apparatus, the received encoded voice to its associated PMG 110 in the format of the respective CODEC 120 of its associated PMG 110 . By way of example, in exemplary network 100 , VM- 2 in VPMG 130 comprises a transceiver and/or other means for receiving and/or transmitting encoded voice in the PTT format, used by CODEC- 2 comprised in its associated PMG- 2 . VM- 2 is also adapted to retransmit encoded voice received in the CODEC- 2 format to the other VMs 140 , VM- 1 , VM- 3 . . . VM-N, in VPMG format 150 . VM- 2 is further adapted to receive from VM- 1 , VM- 3 . . . VM-N voice encoded in common VPMG format 150 and to retransmit to PMG- 2 in CODEC- 2 format.
It is noted that in FIG. 1 , and in the description above, it is assumed that each VM 140 comprises a transceiver and/or transcoder for receiving, transmitting, decoding and encoding transmissions from and to PTT participants of its associated PMG 110 . However, a suitable transceiver and/or transcoder associated with a given VM 140 is not necessarily comprised in the VM 140 . The transceiver and/or transcoder may be configured using any of various suitable devices and/or methods known in the art and may be any suitable hardware and/or software device known in the art for receiving, transmitting, decoding and encoding transmissions that is separate from a VM 140 .
The following is a description of how an optionally PoC communication session is conducted by PTT network 100 , in accordance with an embodiment of the invention. A single PTT participant (not shown) in a given PMG 110 who wishes to talk and first sends a signal through the network is considered the sender. The signal may be initiated by a participant that, for example, presses on a button on the participant's cellular mobile phone (not shown) to initiate a PTT communication session. The signal is recognized by a PTT session manager (not shown), for example, a processor or processors in a PoC server (not shown), or a plurality of PoC servers, that support and manage PTT network 100 . The PTT network manager assigns the participant originating the signal with the status of sender and VM 140 associated with the participant's PMG 110 is assigned the status of listener in the PMG but the status of sender in VPMG 130 . All other participants in all the other PMGs 110 are assigned the status of listener. All VMs 140 in VPMG 130 other than the VM 140 associated with the sender's PMG 110 are assigned the status of listeners in the VPMG but also the status of senders in their respective associated PMGs 110 . As long as the participant with the sender status maintains sender status, any voice message transmitted by the sender will in general be received by substantially all the participants in all PMGs 110 .
For example, assume that the sender talks into his or her cell phone. The sender's phone encodes the vocal message in accordance with the PTT format of CODEC 120 of PMG 110 to which the sender belongs and transmits the encoded message. The encoded message is received by VM 140 associated with the sender's PMG 110 in VPMG 130 , which is acting as listener in the sender's PMG 110 . The associated VM 140 , which also holds the status of sender in VPMG 130 , retransmits the received encoded message “reformatted” in the VPMG PTT format. All the other VMs 140 , which have listener status in VPMG 130 , receive the VPMG formatted message and each reformats the received message in the format of its own associated PMG 110 . Each of the other VMs 140 , although being a listener in VPMG 130 , is also a sender in its own associated PMG 110 and transmits the message it has reformatted to all the participants in its associated PMG. The participant's original vocal message is therefore transmitted via VPMG 130 to all participants in network 100 .
FIG. 2 schematically illustrates operation of PTT network 100 shown in FIG. 1 , in which, by way of example, a participant (not shown) in PMG- 2 initiates a communication session and transmits voice messages to listeners (not shown) in the different PMGs 110 comprised in the network, in accordance with an embodiment of the invention.
The PMG- 2 participant initiates the communication session by being a first participant to signal in PTT network 100 during a time when no PTT communication session is in process. The participant in PMG- 2 is assigned the status of sender. All other participants in PMG- 1 , PMG- 2 . . . PMG-N are assigned the status of listeners, with only reception capabilities (receivers). VM- 2 is assigned the status of listener in PMG- 2 , but the status of sender in VPMG 130 . Each of the other VMs 140 in VPMG 130 is assigned the status of listener in the VPMG but the status of sender in its associated PMG 110 . The sender in PMG- 2 may now transmit encoded messages, optionally voice signals, represented by a bold, striped arrow 270 , which are formatted by CODEC- 2 in accordance with its PTT format as PTT signals represented by bold striped arrows 271 . VM- 2 , previously assigned status as a listener in PMG- 2 receives PTT signal 271 . However, VM- 2 is also a sender in VPMG 130 and it retransmits the signal to all VMs 140 in VPMG 130 in VPMG format 150 ( FIG. 1 ) as PTT signals 273 . VM- 1 , VM- 3 , VM- 4 . . . VM-N, previously designated as VPMG listeners in VPMG 130 receive PTT signals 273 and convert the received signals to signals 274 formatted in the PTT formats of CODEC- 1 , CODEC- 3 , CODEC- 4 . . . CODEC-N respectively. Each VM- 1 , VM- 3 , VM- 4 . . . VM-N is a sender in its associated PMG; PMG- 1 , PMG- 3 , PMG- 4 . . . PMG-N and transmits the signals it converts to participants in its associated PMG; PMG- 1 , PMG- 3 , PMG- 4 . . . PMG-N. Each participant in PMGs 140 therefore receives a signal 274 that is understood by the CODEC in the participant's cell phone and is able to hear the original message sent by the sender in PMG- 2 .
It is noted that implementation of VPMG 130 may be in one or more server-level PoC network processors. Furthermore, according to some embodiments of the invention, a plurality of VPMGs may be implemented in one or more server level PoC network processors and/or in different configurations. For example, VPMGs can be nested, in accordance with an embodiment of the invention, with at least one PMG itself comprising a VPMG and coupled to other PMGs by a VPMG in a PTT communication network similar to PTT communication network 100 .
FIG. 3 schematically shows a PTT communication network 200 comprising nested VPMGs in accordance with an embodiment of the invention. PTT communication network 200 comprises a plurality of PMGs, PMG- 1 . . . PMG-N that are coupled to each other by a VPMG 202 , similar to VPMG 130 ( FIG. 1 ). VPMG 202 comprises a VPMG CODEC 204 and virtual members VM- 1 . . . VM-N associated respectively with PMG- 1 . . . PMG-N. However, at least one of PMGs 110 in PTT network 200 , itself comprises a VPMG. By way of example, in PTT network 200 , PMG- 2 comprises a VPMG 300 that couples a plurality of PMGs, PMG*- 1 . . . PMG*-M having CODECs, CODEC*-L . . . CODEC*-M respectively in a PTT communication network. VPMG 300 has a VPMG CODEC 302 for encoding messages communicated between its virtual members VM*- 1 . . . VM*-M. VM- 2 in VPMG 202 couples VPMG 300 to PMGs, PMG- 1 , PMG- 3 . . . PMG-N in PTT communication network 200 similar to the manner in which VPMG 130 couples PMGs 10 in communication network 100 . VM- 2 receives and transmits messages from and to VPMG 300 in the format of VPMG CODEC 302 and receives and transmits messages to VM- 1 , VM- 3 . . . VM-N in the format of VPMG CODEC 204 .
In the description and claims of embodiments of the present invention, each of the words, “comprise” “include” and “have”, and forms thereof, are not necessarily limited to members in a list with which the words may be associated.
The invention has been described using various detailed descriptions of embodiments thereof that are provided by way of example and are not intended to limit the scope of the invention. The described embodiments may comprise different features, not all of which are required in all embodiments of the invention. Some embodiments of the invention utilize only some of the features or possible combinations of the features. Variations of embodiments of the invention that are described and embodiments of the invention comprising different combinations of features noted in the described embodiments will occur to persons with skill in the art. The scope of the invention is limited only by the claims. | A communication system comprising: at least one first communication device configured to communicate in half duplex mode using a first encoding-decoding format; at least one second communication device configured to communicate in half duplex mode using a second encoding-decoding format; a third communication device configured to communicate in half duplex mode using the first format; a fourth communication device configured to communicate in half duplex mode using the second format; wherein the third and fourth communication devices are configured to communicate with each other in half duplex mode using a third encoding decoding format. | 7 |
BACKGROUND OF INVENTION
1. Technical Field of Invention
The present invention generally relates to a modified glycol coolant circuit within a motor vehicle having a coolant/refrigerant heat exchanger for thermal coupling of a cooling plant/heat pump with the coolant circuit, whereby the glycol circuit is adapted to the requirements of a heat pump for the heating of the interior passenger compartment of the motor vehicle with a glycol/water mixture as the heat carrier.
2. Description of the Prior Art
Cooling plants and heat pumps are utilized to cool or heat an interior space. The varying weather conditions caused by the sequence of seasons frequently require a heating system in winter and transitional periods and a cooling system in summer.
Prior art devices have been developed comprising the combination of a heat pump and a cooling plant to alternately provide heating or cooling to interior rooms of a building or to provide heating or cooling to the interior passenger compartment of an automotive vehicle.
Typically, in an automotive vehicle, heat from the engine is used to heat the interior of the vehicle. Modern combustion engines and electric motors tend to produce smaller and smaller amounts of waste heat. Therefore, future vehicle engines will yield sufficient amounts of heat to heat the passenger compartment, but not at the temperature level required. Particularly in winter, the cold-start phase is a problem. In some current diesel engine vehicles, supplementary heating systems with heater plugs, resistance heating systems, or fuel-fired burners have been provided, to supplement the heat provided by the engine.
Many automotive vehicles are equipped with a cooling plant to air condition the passenger compartment in hot weather situations. One alternative to using a supplementary heating system of improve the heating of the interior passenger compartment within the vehicle is to alternatively use the cooling plant as a heat pump in cold weather situations.
Prior art devices have combined cooling plants and heat pumps for use within automotive vehicles. The heat of the environment is used as a heat source, and alternatively, when needed, the temperature of the engine's waste heat is increased by the heat pump. For the use of a combined cooling plant/heat pump, where a glycol coolant circuit is the heat source of the heat pump, the cooling circuit must be adapted for this use.
Referring to FIG. 1, a prior art coolant circuit is divided into a first circuit 1 and a second circuit 2 . A glycol/water mixture flows through the coolant circuit and is moved by a pump 7 . The glycol/water mixture cools the engine 16 , thereby assimilating heat and continuously flowing within the first circuit 1 . A heat exchanger 3 of the heating system is positioned within the first circuit, whereby heat is absorbed from the glycol/water mixture and used to heat the passenger compartment of an automotive vehicle. A thermostat 4 is adapted to open when the temperature of the glycol/water mixture exceeds a pre-determined value. Once the thermostat 4 is opened, the glycol/water mixture is allowed to flow into the second circuit 2 . A radiator is positioned within the second circuit 2 and is adapted to radiate heat from the glycol/water mixture to the environment, thereby removing waste heat of the engine to the environment.
In addition, the refrigerant circuit, which preferably uses carbon dioxide as refrigerant, is designed according to the state-of-the-art such that both the cooling plant operational mode and the heat pump operational mode are possible.
The refrigerant circuit and the coolant circuit each have a number of components. The components must be meticulously assembled, either manually or by automated methods, because leakage in the system will prevent the system from working properly. Space limitations add difficulties to the assembly of these components.
Therefore, it is the objective of this invention to provide a coolant circuit having features to transfer the heat to a refrigerant circuit wherein the coolant circuit optimizes size, maintenance, and assembly considerations, and the coolant circuit acts as the heat source for a heat pump to heat the passenger compartment of a motor vehicle.
SUMMARY OF THE INVENTION
The disadvantages of the prior art are overcome by providing a coolant circuit for a motor vehicle with a coolant/refrigerant heat exchanger for thermal coupling of a cooling plant/heat pump to the coolant circuit. The coolant circuit is preferably a glycol circuit, whereby the glycol circuit according to the invention is adapted to the requirements of a heat pump for the heating of the passenger compartment of the motor vehicle with a glycol/water mixture as heat carrier, wherein the glycol circuit is thermally coupled over the glycol/refrigerant heat exchanger to the refrigerant circuit of the cooling plant/heat pump such that the glycol/refrigerant heat exchanger together with the external heat exchanger, the radiator, the accumulator/collector, and internal heat exchanger forms a space-saving, easy to assembly and low maintenance heat exchanger module with integrated connection lines for heat transfer from the glycol circuit to the refrigerant circuit.
In another aspect of the present invention, a high-pressure selector valve and a low-pressure selector valve of the refrigerant circuit are integrated into the heat exchanger module. The design of the coolant and refrigerant circuits according to the present invention allows the number of connection ports to be reduced, and the supplier can pre-assemble the heat exchanger module using dedicated assembly technology. These features result in cost savings and enhanced quality. Additionally, particularly in winter, the ride comfort improves due to the coupling according to the present invention of the coolant and refrigerant circuits and use of the heat pump, as the desired temperature in the interior of the passenger compartment can be achieved more rapidly.
Further details, features and advantages of the invention ensue from the following description of examples of embodiments with reference to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a prior art coolant circuit;
FIG. 2 is a schematic view of a refrigerant circuit and a coolant circuit for a heat pump;
FIG. 3 is a schematic view of a glycol circuit with a bypass for the glycol/refrigerant heat exchanger and controlled heating heat exchanger;
FIG. 4 is a schematic view of a Glycol circuit with a controlled glycol/refrigerant heat exchanger and a controlled heating heat exchanger;
FIG. 5 is a schematic front view of a heat exchanger module of the present invention; and
FIG. 6 is a schematic top view of the heat exchanger module shown in FIG. 5 .
DETAILED DESCRIPTION OF THE INVENTION
The following description of the preferred embodiment of the invention is not intended to limit the scope of the invention to this preferred embodiment, but rather to enable any person skilled in the art to make and use the invention.
Referring to FIG. 2, a first preferred embodiment of the cooling circuit according to the present invention is shown. A glycol circuit 1 , 2 is thermally coupled over a glycol/refrigerant heat exchanger 6 to a refrigerant circuit 23 . The refrigerant circuit 23 is adapted to function as either a cooling plant, for cooling and air conditioning of the passenger compartment or as a heat pump, for the heating of the passenger compartment of the vehicle.
When the cooling circuit is operating as a cooling plant, the refrigerant is compressed in the compressor 9 . Preferably, the refrigerant is carbon dioxide (R744), tetrafluorethane (R134a), or propane (R290), however it is to be understood, that other refrigerants could be used within the scope of the present invention.
The compressed refrigerant passes through a high-pressure selector valve 17 and into an external heat exchanger 22 , where the refrigerant dissipates heat energy to the environment. The cooled, and at least partially condensed, refrigerant then passes through an internal heat exchanger 20 , which also functions as an accumulator/collector, and on to a flash element 19 , where the refrigerant expands to the evaporation pressure level. When the cooling circuit is functioning as a cooling plant, an internal heat exchanger 18 functions as an evaporator, wherein the refrigerant evaporates, thereby taking heat from the passenger compartment. The vaporized refrigerant then passes through a low-pressure selector valve 21 and a low-pressure side of the internal heat exchanger 20 to the compressor 9 , where the circuit for operation as a cooling plant closes.
When the circuit is operating as a heat pump, the refrigerant is first compressed in the compressor 9 , then flows through the high-pressure selector valve 17 to the internal heat exchanger 18 . The internal heat exchanger 18 works as a condenser when the circuit is operating as a heat pump, and dissipates the condensation heat to the passenger compartment for heating. The refrigerant then flows in a direction opposite to the direction of flow in coolant plant mode, through the expansion element 19 and the internal heat exchanger 20 and finally reaches the glycol/refrigerant heat exchanger 6 , which thermally couples the refrigerant circuit to the coolant circuit. Within the glycol/refrigerant heat exchanger 6 , the liquid refrigerant takes heat from the coolant circuit while evaporating, and the refrigerant vapor then passes through the low-pressure selector valve 21 and the low-pressure side of the internal heat exchanger 20 to the compressor 9 .
When functioning as a cooling plant, the external heat exchanger 22 is bypassed, and when functioning as a heat pump, the glycol/refrigerant heat exchanger 6 is bypassed. All other components of the circuit are required for both operation as a cooling plant and as a heat pump.
When using the engine's waste heat as a heat source as shown in FIG. 2, the engine heat is fed to the heat pump through the coolant circuit. To achieve this, the glycol/refrigerant heat exchanger 6 is channelled into the small circuit 1 of the glycol circuit parallel to the heating heat exchanger 3 .
In the coolant circuit the glycol/water mixture is moved by a pump 7 . The glycol/water mixture passes through the cooling system of the engine 16 and absorbs waste heat of the engine. Within a thermostat valve 4 the coolant is passed into the small circuit 1 and/or the big circuit 2 . In the small circuit 1 the coolant flows to a multi-way directional valve 8 , where the coolant flow is divided, flowing in parallel through the glycol/refrigerant heat exchanger 6 and the heating heat exchanger 3 . In this way, the multi-way directional valve is adapted to enable both the parallel passage of the heating heat exchanger 3 and the glycol/refrigerant heat exchanger 6 , and the alternate single passage of the heat exchangers 3 , 6 .
The refrigerant is then again moved by the pump 7 through the engine 16 to absorb waste heat from the engine, thus closing the circuit. When the heating demand of the passenger compartment decreases, the thermostat valve 4 provides the big circuit 2 with coolant in that measure as less heat is needed and the engine's waste heat is dissipated through the radiator 5 to the environment.
Dependent on the operational cycle different switching versions must be made possible by the coolant and refrigerant circuits 2 , 23 . These operation versions include operation as an air conditioner; operating to reheat or heat; warm-up operation, wherein the circuit operates as a heat pump with glycol as the heat source; stationary operation or operating to heat the heat exchanger, wherein after the glycol reaches the necessary temperature the heat pump is switched off; and safety function. If the refrigerant is unintendedly stored in the refrigerant/glycol heat exchanger and does not actively take part in the circuit operation as a cooling plant, the heat exchanger is passed by “warm” glycol and the refrigerant “expelled”.
To achieve these variations, a multi-way directional valve 8 is provided within the coolant circuit. The multi-way directional valve is adapted to function either as a thermostat or as an electronic valve. Further, the multi-way directional valve 8 is adapted to function as an electrical controlling unit so that it can also be used for flow control, and hence temperature control, of the heat exchanger 3 of the heating system. This also allows the system to be smaller by eliminating components normally required for the air conditioning unit.
Referring to FIG. 3, in a second preferred embodiment, an electrical controlling unit is adapted such that the flow through the heating heat exchanger is controlled with a multiway water valve 10 , whereby a bypass flow is passed over the glycol/refrigerant heat exchanger 6 .
Referring to FIG. 4, by using two-way water valves 10 , the coolant flow can be controlled over both heat exchangers 3 , 6 , or over several heating heat exchangers 3 or heat exchanger zones that are given different temperatures. Multiway valves could also be used in place of the two-way water valves 10 .
By use of the heat pump according to the present invention the space requirements of the heating heat exchangers can be reduced by up to 30%. Referring to FIGS. 5 and 6, The space-saving design and arrangement of heat exchangers and valves according to the present invention is illustrated.
According to the present invention, the glycol/refrigerant heat exchanger 6 for thermal coupling of the cooling plant/heat pump to the glycol circuit is combined with the external heat exchanger 22 , radiator 5 , and accumulator/collector and internal heat exchanger 20 to form a space-saving, easy to assembly, and maintenance-friendly heat exchanger module 28 , which contains connection lines between the components of the module 28 .
The structural integration of the glycol/refrigerant heat exchanger 6 , external heat exchanger 22 , and radiator 5 reduces the number of connections and enables a compact design with reduced leakage flow.
It is particularly advantageous to integrate the high-pressure selector valve 17 and the low-pressure selector valve 21 of the refrigerant circuit 23 into the heat exchanger module 28 . This allows that the heat exchanger module 28 to be equipped with only four refrigerant outer ports. One port for the connection of the heat exchanger module 28 to the suction side of the compressor 24 , one port for the connection to the pressure side of the compressor 25 , one port for the connection to the flash element 26 , and one port for the connection to the internal heat exchanger 27 . Additionally, the heat exchanger module 28 includes four coolant ports, which are not shown, for the connection to the radiator 5 and glycol/refrigerant heat exchanger 6 .
Preferably, a connection line from the glycol/refrigerant heat exchanger 6 and the low-pressure selector valve 21 is installed within the accumulator/collector and internal heat exchanger 20 , such that the connection of the line to the glycol/refrigerant heat exchanger 6 and the low-pressure selector valve 21 is performed during the pre-assembly process, thereby eliminating another connection point.
The glycol/refrigerant heat exchanger 6 is dimensioned according to the invention such that during the start phase of the engine 16 in winter operation only a portion of the waste heat is taken from the glycol circuit. This is necessary because at very deep temperatures the engine works with a very low efficiency and produces harmful noxious emissions. Therefore, only heat that originates from the operation of the compressor 9 can be used. This portion should be in the range of approximately 50%, depending upon the dimensioning of the engine. At higher temperatures of the glycol in warmed-up conditions of the engine 16 this limit no longer applies.
The foregoing discussion discloses and describes the preferred embodiments of the invention. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims, that changes and modifications can be made to the invention without departing from the scope of the invention as defined in the following claims. The invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. | A heat exchanger module includes a glycol coolant circuit adapted to function as a heat pump for the heating of the interior passenger compartment of the motor vehicle with a glycol/water mixture as the heat carrier, a refrigerant circuit, and a glycol/refrigerant heat exchanger positioned between and interconnecting the cooling circuit and the refrigerant circuit, wherein the glycol/refrigerant heat exchanger has integrated connection lines for heat transfer from the coolant circuit to the refrigerant circuit. | 5 |
PRIORITY
The present invention claims priority to PCT patent application PCT/CN2013/083379, which has a filing date of Sep. 12, 2013. The present invention claims priority to Chinese patent application 201210375871, which has a filing date of Sep. 28, 2012.
FIELD OF THE INVENTION
This invention relates to fuel cell mixed power supply energy management method.
BACKGROUND
Through retrieving existing technologies, the following literatures are retrieved:
The fuel cell power supply control principle publicized by the invention patent application of China called “power distribution method for fuel cell mixed power system” with application number “200310103253.3”: Adopt SOC calculation to control according to measurement load control signal (such as throttle signal) and power cell SOC (state of charge) the output of the fuel cell DCDC to satisfy the energy demands of the load system, fuel cell system and power cell pack under the state of charge.
The fuel cell power supply control method publicized by the invention patent application of China called “fuel cell based mixed power device energy management system” with application number “201010108281.4” also adopts SOC calculation, where,
Here is the calculation formula for the state of charge (SOC):
soc( k )=( BC ×soc( k− 1)−∫ k-1 k i out dt+∫ k-1 k i out dt )/ BC
In the above calculation formula, BC represents cell capacity, soc(k) represents the SOC value of cell at current moment, soc(k−1) represents the SOC value at the previous moment, i out represents cell discharging current and i in represents cell charging current.
It is known from the above formula that the SOC calculation is a kind of algorithm to obtain the state of charge (SOC) of battery according to the battery current data collected, the cell capacity data set, based on the integration algorithm and by correcting according to the actual cell capacity, cell voltage, temperature at the time of actual use. That invention application has the following disadvantages:
1. All the above control method relies on SOC calculation; and the SOC calculation relies on accurate current data, the accuracy of current data depends on the accuracy, sensitivity, stability of current measurement device; however, the current measurement device also has an error; therefore, the SOC calculation method can only be an approximate estimation of the state of charge of the energy storage device. The existing fuel cell system on board vehicle using the SOC calculating method adopts a dual-range current sensor in order to obtain a relatively accurate current value; however, a dual-range current sensor is unable to cover the whole range and at the same time is also unable to avoid the zero drift that the current sensor has, therefore, the current sensor has to be calibrated frequently. In this circumstance, a fuel cell company, after selling a fuel cell system on board vehicle, has to calibrate regularly the current measurement device sensor. The product immaturity will directly influence the mercerization progress of fuel cell vehicles.
2. The capacity of the energy storage device (battery) may reduce with use gradually. It is known from the formula that in order to obtain SOC accurately, it is imperative to have an accurate capacity value of the energy storage device. Therefore, it is imperative to calibrate the capacity of the energy storage device (battery), which can only be a vague estimation. Therefore, it is unable to accurately conduct the fuel cell system energy management by adopting the SOC calculation method.
3. The current output fluctuation amplitude is large when a forklift is working.
The voltage of the energy storage device (battery) used on fuel cell bus, fuel cell car as auxiliary power is often hundreds of volts, the current range is from negative tens of amperes to positive tens of amperes; under the circumstance that the current range is small, the accuracy of battery current value is relatively high, under this working condition, though the use of the SOC calculation method is not so good as the said fuel cell mixed power supply energy management method, it is barely satisfactory.
The voltage of the energy storage device (battery) used on fuel cell forklift as auxiliary power is often tens of volts, but the current range fluctuates largely. For example, the common nominal voltage 24V corresponds to a working current range −500˜500 A; the nominal voltage 36V corresponds to a working current range −800˜1000 A, the nominal voltage 48V corresponds to a current range −600˜800 A. This is because when a fuel cell forklift is working, it constantly lifts loads, drives at an accelerated speed, brakes, etc. that result in the output current of the battery increasing from several amperes gradually to hundreds of amperes and even a thousand amperes and turning from outputting a thousand amperes to inputting hundreds of amperes. As the current range is large, it is very difficult to measure the current value accurately; at the same time, that the current output fluctuation frequency is high when a forklift is working further makes real-time and accurate current measurement become very difficult; and SOC integration algorithm can also amplify the deviation constantly. Therefore, it is unable to realize an accurate fuel cell system energy management by adopting the SOC calculation method on a fuel cell forklift.
4. Energy recovery issue, protection issue.
When a fuel cell vehicle with an energy recovery system (such as the invention patent application called “power distribution method for fuel cell mixed power system” with application number “200310103253.3”) brakes for energy recovery, the energy resulting from braking is input in the energy storage device with a current being often as high as hundred of amperes and even up to 1000 A in some cases, then the voltage of the energy storage device will increase sharply, at the same time, the internal resistances of cables, connections, relays, etc. in the circuits through which current passes at recovery braking can all cause the vehicle voltage to rise; if the battery voltage exceeds the protection voltage of the energy storage device, or the vehicle voltage exceeds the protection voltage of the vehicle, the system or vehicle may disconnect the relay making external connection to realize equipment protection. As a result of disconnecting the relay, the energy storage device is unable to continue to absorb the braking energy and braking can not proceed normally. The vehicle may be out of control and even have an accident. In order that at energy recovery, the voltage of the energy storage device does not exceed the protection voltage of the energy storage device, or the vehicle voltage does not exceed the protection voltage of the vehicle, it is imperative to control the actual state of charge (SOC) of the energy storage device to be a right or a lower value.
However, as the SOC calculation is based on the measured battery current value and the actual battery capacity and as the battery current data, the actual battery capacity can not be measured accurately, it results in the SOC calculation method being unable to obtain the actual SOC values. When the SOC measurement value is lower than the actual value, the actual state of charge (SOC) of the energy storage device is at a high value, the voltage of the energy storage device will exceed the protection voltage of the energy storage device or the protection voltage of the vehicle; this will constitute a safety hazard to the fuel cell vehicle.
The said fuel cell mixed power supply energy management method is to control the output current of the DCDC converting unit, respond to the energy demand resulting from load condition change and at the same time ensure the energy storage device to be in a best state of charge according to the measured voltage of the energy storage device and the actual current output by the DCDC converting unit under the circumstance without connecting the vehicle operation input signal (throttle, brake) and calculating SOC.
SUMMARY
The said fuel cell mixed power supply energy management method includes the following steps:
Step S 201 : Initialize, specifically, obtain the following parameter values first:
The first current setting of DCDC Isetmin, The first voltage setting of energy storage device Umax, The second voltage setting of energy storage device Umin, The permissible DCDC current deviation value Ipermissible, The maximum current setting that DCDC allows to output Imax,
Then let the current setting of DCDC Iset equal to the said first current setting of DCDC Isetmin;
Step S 202 : Obtain the energy storage device voltage Ustorage and the actual output current of DCDC converting unit Idcdc, calculate according to the following formula (1) DCDC current deviation value Ideviation:
I deviation= I set− Idcdc Formula (1);
Step S 203 : in case of meeting the following circumstances, enter into Step S 204 , Step S 205 or Step S 206 :
If the energy storage device voltage Ustorage is greater than or equal to the first voltage setting of energy storage device Umax, then enter into Step S 204 , If the energy storage device voltage Ustorage is less than or equal to the first voltage setting of energy storage device Umin, then enter into Step S 205 , If the energy storage device voltage Ustorage is less than the first voltage setting of energy storage device Umax and greater than the first voltage setting of energy storage device Umin, and the DCDC current deviation value Ideviation is greater than or equal to the permissible DCDC current deviation value Ipermissible, then enter into Step S 206 , If the energy storage device voltage Ustorage is less than the first voltage setting of energy storage device Umax and greater than the first voltage setting of energy storage device Umin, and the DCDC current deviation value Ideviation is less than the permissible DCDC current deviation value Ipermissible, then enter into Step S 207 ;
Step S 204 : If the current setting of DCDC Iset is greater than the first current setting of DCDC Isetmin, then gradually reduce the current setting of DCDC Iset, and then enter into Step S 207 ; if the current setting of DCDC Iset is less than or equal to the first current setting of DCDC Isetmin, then let the current setting of DCDC Iset is equal to the said first current setting of DCDC Isetmin and then enter into Step S 207 ;
Step S 205 : If the current setting of DCDC Iset is less than the maximum current setting that DCDC allows to output Imax, increase the current setting of DCDC Iset and then enter into Step S 207 ; if the current setting of DCDC Iset is greater than or equal to the maximum current setting that DCDC allows to output Imax, let the current setting of DCDC Iset equal to the maximum current setting that DCDC allows to output Imax and then enter into Step S 207 ;
Step S 206 : If the current setting of DCDC Iset is greater than the first current setting of DCDC Isetmin, reduce at a fastest speed the current setting of DCDC Iset and then enter into Step S 207 ; if the current setting of DCDC Iset is less than or equal to the first current setting of DCDC Isetmin, let the current setting of DCDC Iset equal to the said first current setting of DCDC Isetmin and then enter into Step S 207 ;
Step S 207 : Send a current setting instruction to DCDC converting unit, in which the said current setting instruction is used to set the output current of the DCDC converting unit as the current setting of DCDC Iset and then return to Step S 202 .
Preferably, before the said Step S 201 , the following steps executed in proper order are also included:
Step A 1 : Determine the limit voltage Ulim, specifically, judge if the highest limit of load protection voltage is greater than the charging protection voltage of the energy storage device; if the judgment result is positive, set the limit voltage Ulimit as equal to the charging protection voltage of the energy storage device; if the judgment result is negative, set the limit voltage Ulimit as equal to the highest limit of load protection voltage;
Step A 2 : Determine the expected DCDC converting unit output current Iexpect according to the following formula (2):
Iexpect
=
Irated
·
Edcdc
U
lim
Where Irated is the rated output power of the fuel cell, Edcdc is the efficiency of the DCDC converting unit;
Step A 3 :
On the current curve using expected DCDC converting unit output current as a constant charging value, obtain the corresponding charging capacity as 50%˜90% of the voltage interval, select any voltage value in the voltage interval as the first voltage setting of energy storage device Umax.
Preferably, in the said Step A 3 , from the corresponding charging capacity being any voltage value or voltage interval below, set the said voltage value as or select any voltage value in the said voltage interval as the first voltage setting of energy storage device Umax:
The corresponding charging capacity is the voltage value at 90%, determine the voltage value at the said 90% as the first voltage setting of energy storage device Umax, The corresponding charging capacity is 60%˜80% voltage interval, select any voltage value in the said 60%˜80% voltage interval to be determined as the first voltage setting of energy storage device Umax, The corresponding charging capacity is 80%˜90% voltage interval, select any voltage value in the said 80%˜90% voltage interval to be determined as the first voltage setting of energy storage device Umax, The corresponding charging capacity is 50%˜60% voltage interval, select any voltage value in the said 50%˜60% voltage interval to be determined as the first voltage setting of energy storage device Umax.
Preferably, before the said Step S 201 , the following steps executed in proper order are also included:
Step B 1 : Determine the system limit charging current, specifically,
Under the working condition in which the system uses medium limit energy recovery, first use battery to make a braking action and obtain the system current, time data from braking to the end, the negative current of that system is the charging current, calculate the average of that charging current as the system limit charging current;
Step B 2 : Determine the limit voltage Ulim, specifically, judge if the highest limit of load protection voltage is greater than the charging protection voltage of the energy storage device; if the judgment result is positive, set the limit voltage Ulimit as equal to the charging protection voltage of the energy storage device; if the judgment result is negative, set the limit voltage Ulimit as equal to the highest limit of load protection voltage;
Step B 3 : Determine the expected DCDC converting unit output current Iexpect according to the following formula (2):
Iexpect
=
Irated
·
Edcdc
U
lim
Where Irated is the rated output of the fuel cell, Edcdc is the efficiency of the DCDC converting unit;
Step B 4 : Inquire the testing curves of different charging currents and charging capacitances; according to the constant current charging curve that the system limit charging current corresponds to, obtain the corresponding charging capacitance when charging to the limit voltage; according to that charging capacity, look up the corresponding voltage value on the constant current charging curve that the expected DCDC converting unit output current Iexpect corresponds to, the said corresponding voltage value is the first voltage setting of energy storage device Umax;
Step B 5 : According to the energy recovery working condition when the system uses time limit, do actual testing by using the system controlled by the first voltage setting of energy storage device Umax, correct the first voltage setting of energy storage device Umax so that the actually measured highest voltage is slightly lower than the limit voltage Ulim;
Step B 6 : Correct the capacity of the energy storage device, specifically, according to the relational curve between energy storage device charging capacity/rated capacity and cycle times, or the relational curve between the discharging capacity/rated capacity and cycle times, inquire the charging capacity/rated capacity ratio after multiple cycles, and then take the product of the first voltage setting of energy storage device Umax and the charging capacity/rated capacity ratio as the corrected first voltage setting of energy storage device Umax.
Preferably, before the said Step S 201 , the following steps executed in proper order are also included:
Step C 1 : Determine the minimum consumption current of the auxiliary system Is, specifically, use the system controlled by the first voltage setting of energy storage device Umax to have the system be in an idle condition, after the system becomes stable, the consumption of the auxiliary system reduces to the minimum, measure the current of the auxiliary system at this time, which is the minimum consumption current;
Step C 2 : take the product of the minimum consumption current of the auxiliary system and the coefficient K as the first current setting of DCDC Isetmin, where the coefficient K is less than 1.
Preferably, the coefficient K is 0.6.
Preferably, before the said Step S 201 , the following steps executed in proper order are also included:
Step D 1 : Determine according to the follow formula (3) the maximum current setting that DCDC allows to output Imax:
I
max
=
Irated
·
Edcdc
U
max
Preferably, before the said Step S 201 , the following steps executed in proper order are also included:
Step E 1 : Determine according to the following formula (4) the capacitance at the minimum load Cmin:
C min= C −( Is−I setmin )· T
Where, C is the charging capacity, Is is the minimum consumption current of the auxiliary system, T is time, the said charging capacity is the charging capacity that the first voltage setting of energy storage device Umax corresponds to inquired on the charging capacity and charging voltage curve with constant current charging taking the maximum current setting that DCDC allows to output Imax as the current, the said time is set according to the response speed that the system requires;
Step E 2 : According to the capacitance at minimum load Cmin, inquire the charging voltage that the capacitance at the minimum load Cmin corresponds to on the charging capacity and charging voltage curve with constant current charging taking the maximum current setting that DCDC allows to output Imax as the current, select that charging voltage as the second voltage setting of energy storage device Umin.
This invention provides a fuel cell mixed power supply energy management method. The said method is to control the output current of the DCDC converting unit, respond to the energy demand resulting from load condition change and at the same time ensure the energy storage device to be in a best state of charge according to the measured voltage of the energy storage device and the actual current output by the DCDC converting unit under the circumstance without connecting the vehicle operation input signal (throttle, brake) and calculating SOC.
In comparison with the existing technology, the said fuel cell mixed power supply energy management method has the following beneficial effects:
1. Improve the fault-tolerant capability of the system. As the control method no longer adopts the SOC calculation mode, the system no longer relies on the accuracy, reliability of the current sensor. 2. Strong compatibility. By setting the charging current condition at a limit condition, the same system is applicable to more models of different vehicles (forklift) and no parameter correction is necessary. 3. High reliability. By setting parameters beforehand to correct in advance the reduction in batter capacity, the long-term system reliability is ensured. The said fuel cell mixed power supply energy management method also uses the data of the energy storage device in determining parameters. These data are that measured in laboratory under a stable working condition; and in the existing system using the SOC calculation mode, the data of the energy storage device is calculated on real-time basis when the system is working, which a kind of dynamic estimation with the accuracy is being not satisfactory. 4. Stable output voltage. The system controls the energy storage device voltage near the first voltage setting of energy storage device Umax, the second voltage setting of energy storage device Umin, this favors to extend the service life to use the vehicle equipment, the energy storage device. 5. Strong practicality. The said fuel cell mixed power supply energy management method is obtained by conducting a lot of actual tests and verifications on multiple models of forklift fuel cells and constant adjustment. A verification was also made on the fuel cell system of a tourist coach. It can not only be used on vehicles, but also adapts to a power supply system.
BRIEF DESCRIPTION OF THE DRAWINGS
By reading and referring to the detailed descriptions made to the non-restrictive embodiment examples by the following attached figures, other characteristics, purposes and advantages of this invention will become more evident:
FIG. 1 is the general framework flow chart of the first fuel cell mixed power supply energy management method;
FIG. 2 is the flow chart of the second type of fuel cell mixed power supply energy management method;
FIG. 3 is the flow chart of the third type of fuel cell mixed power supply energy management method;
FIG. 4 is the flow chart of the forth type of fuel cell mixed power supply energy management method;
FIG. 5 is the flow chart of the fifth type of fuel cell mixed power supply energy management method;
FIG. 6 is the schematic diagram of current curve of the DCDC converting unit output current with charging expected at a constant value;
FIG. 7 is the system limit current test curve;
FIG. 8 is the schematic diagram for selecting the first voltage setting of energy storage device Umax;
FIG. 9 is the schematic diagram for the process of correcting the first voltage setting of energy storage device Umax;
FIG. 10 is the curve for the relation between energy storage device charging capacity/rated capacity and cycle times;
FIG. 11 is the schematic diagram of the structure of the compact type fuel cell supply system of the first embodiment example provided according to this invention;
FIG. 12 is the specific structural schematic diagram of the DCDC converting unit in the compact type fuel cell supply system as shown in FIG. 11 ;
FIG. 13 shows the schematic diagram of the high-power diode position in the compact type fuel cell supply system of a preferable case of the first embodiment example provided according to this invention;
DETAILED DESCRIPTION
A detailed description to this invention is to be made below by combining with specific embodiment examples. The following embodiment examples will help the technical personnel in this field further understand this invention, but it does not limit this invention in any form. It should be pointed out that for ordinary technical people in this field, adjustments and changes can also be made under the prerequisite of not being divorced from the conceiving of this invention. All these belong to the protection scope of this invention.
FIG. 1 is the general framework flow chart of the first fuel cell mixed power supply energy management method; specifically, in this embodiment example, Step S 201 is executed first to initialize, more specifically, to obtain the parameters set by the system, such parameters include the first current setting of DCDC Isetmin, the first voltage setting of energy storage device Umax, the second voltage setting of energy storage device Umin, the permissible DCDC current deviation value Ipermissible, the maximum current setting that DCDC allows to output Imax, and then let the current setting of DCDC Iset equal to the said first current setting of DCDC Isetmin, where the said energy storage device can be a high energy lithium ion cell and a high capacity super capacitor, etc.
Next Step S 202 is executed to obtain the energy storage device voltage Ustorage and the actual output current of the DCDC converting unit Idcdc. The DCDC current deviation value Ideviation is calculated according to the following formula (1):
I deviation= I set− Idcdc Formula (1);
Then Step S 203 is executed: enter into Step S 204 , Step S 205 or Step S 206 correspondingly if the following conditions are met:
If the energy storage device voltage Ustorage is greater than or equal to the first voltage setting of energy storage device Umax, then enter into Step S 204 , If the energy storage device voltage Ustorage is less than or equal to the first voltage setting of energy storage device Umin, then enter into Step S 205 , If the energy storage device voltage Ustorage is less than the first voltage setting of energy storage device Umax and greater than the first voltage setting of energy storage device Umin, and the DCDC current deviation value Ideviation is greater than or equal to the permissible DCDC current deviation value Ipermissible, then enter into Step S 206 , If the energy storage device voltage Ustorage is less than the first voltage setting of energy storage device Umax and greater than the first voltage setting of energy storage device Umin, and the DCDC current deviation value Ideviation is less than the permissible DCDC current deviation value Ipermissible, then enter into Step S 207 ;
In which for Step S 204 : if the current setting of DCDC Iset is greater than the first current setting of DCDC Isetmin, reduce gradually the current setting of DCDC Iset and then enter into Step S 207 ; if the current setting of DCDC Iset is less than or equal to the first current setting of DCDC Isetmin, let the current setting of DCDC Iset equal to the said the first current setting of DCDC Isetmin and then enter into Step S 207 ;
Step S 205 : If the current setting of DCDC Iset is less than the maximum current setting that DCDC allows to output Imax, increase the current setting of DCDC Iset and then enter into Step S 207 ; if the current setting of DCDC Iset is greater than or equal to the maximum current setting that DCDC allows to output Imax, let the current setting of DCDC Iset equal to the maximum current setting that DCDC allows to output Imax and then enter into Step S 207 ;
Step S 206 : If the current setting of DCDC Iset is greater than the first current setting of DCDC Isetmin, reduce at the fastest speed the current setting of DCDC Iset and then enter into Step S 207 ; if the current setting of DCDC Iset is less than or equal to the first current setting of DCDC Isetmin, let the current setting of DCDC Iset equal to the said the first current setting of DCDC Isetmin and then enter into Step S 207 ;
Step S 207 : Send a current setting instruction to DCDC converting unit, where the said current setting instruction is used to set the output current of the DCDC converting unit as the current setting of DCDC Iset and then return to Step S 202 .
FIGS. 5 to 8 show the flow charts of type 1 to type 4 fuel cell mixed power supply energy management methods. The technical people in this field can understand the embodiment examples as shown in FIGS. 5 to 8 as 4 preferable cases of the embodiment examples as shown in FIG. 11 , specifically, such 4 preferable cases show 4 types of different embodiments of the said Step S 203 in FIG. 11 .
For example, in FIG. 12 , first judge if “the energy storage device voltage Ustorage is less than or equal to the first voltage setting of energy storage device Umin”, if the judgment result is negative, judge “if the energy storage device voltage Ustorage is greater than or equal to the first voltage setting of energy storage device Umax” next, if the judgment result is negative again, then judge “if the DCDC current deviation value Ideviation is greater than or equal to the permissible DCDC current deviation value Ipermissible”. In which, the technical people in this field understand that when the said energy storage device voltage Ustorage is greater than the first voltage setting of energy storage device Umax or less than the first voltage setting of energy storage device Umin, the DCDC current deviation value Ideviation is not greater than the permissible DCDC current deviation value Ipermissible.
Again for example, in FIG. 13 , first judge “if the energy storage device voltage Ustorage is greater than or equal to the first voltage setting of energy storage device Umax”, if the judgment result is negative, then judge “if the energy storage device voltage Ustorage is less than or equal to the first voltage setting of energy storage device Umin” next, if the judgment result is negative again, then judge “if the DCDC current deviation value Ideviation is greater than or equal to the permissible DCDC current deviation value Ipermissible”.
Again for example, in FIG. 4 , first judge “if the energy storage device voltage Ustorage is less than the first voltage setting of energy storage device Umax and greater than the first voltage setting of energy storage device Umin, and if the DCDC current deviation value Ideviation is greater than or equal to the permissible DCDC current deviation value Ipermissible”, if the judgment result is negative, then judge “if the energy storage device voltage Ustorage is less than or equal to the first voltage setting of energy storage device Umin” next, if the judgment result is negative again, then judge “if the energy storage device voltage Ustorage is greater than or equal to the first voltage setting of energy storage device Umax”.
Again for example, in FIG. 5 , first judge “if the energy storage device voltage Ustorage is less than the first voltage setting of energy storage device Umax and greater than the first voltage setting of energy storage device Umin, and if the DCDC current deviation value Ideviation is greater than or equal to the permissible DCDC current deviation value Ipermissible”, if the judgment result is negative, then judge “if the energy storage device voltage Ustorage is greater than or equal to the first voltage setting of energy storage device Umax” next, if the judgment result is negative again, then judge “if the energy storage device voltage Ustorage is less than or equal to the first voltage setting of energy storage device Umin”.
In a preferable case of this embodiment example, before the said Step S 201 , parameters are determined in the following way: the first voltage setting of energy storage device Umax, the second voltage setting of energy storage device Umin, the permissible DCDC current deviation value Ipermissible and the maximum current setting that DCDC allows to output Imax.
A. In case of system having no energy recovery (adopt a mechanical brake, brake by using the friction between brake block and hub, consume the energy resulting from braking), the steps to determine the first voltage setting of energy storage device Umax are shown below:
Step A 1 : Determine the limit voltage Ulim, specifically, judge if the highest limit of load protection voltage is greater than the charging protection voltage of the energy storage device; if the judgment result is positive, set the limit voltage Ulimit as equal to the charging protection voltage of the energy storage device; if the judgment result is negative, set the limit voltage Ulimit as equal to the highest limit of load protection voltage; where, the load protection voltage is a range value, the charging protection voltage of the energy storage device is a numerical value, all of which are to be supplied by the supplier.
Step A 2 : Determine the expected DCDC converting unit output current Iexpect according to the following formula (2):
Iexpect
=
Irated
·
Edcdc
U
lim
Where, Irated is the rated output power of the fuel cell, Edcdc is the efficiency of the DCDC converting unit;
Step A 3 :
On the current curve using expected DCDC converting unit output current as a constant charging value, obtain the corresponding charging capacity as 50%˜90% voltage interval, select any voltage value in that voltage interval as the first voltage setting of energy storage device Umax. Where, (the current curve with the said expected DCDC converting unit output current as a constant charging value can be supplied by the cell supplier, If there is no right data, approximate currents can be used for replacement, or the curve can be obtained by fitting according to the data at other currents. For example, the curve as shown in FIG. 6 ).
Further preferably, in the said Step A 3 , different charging capacities were selected according to different energy storage devices, different service life requirements. Specifically, from the corresponding charging capacity being as any following voltage value or voltage interval, determine the said voltage value as or select any voltage value of the said voltage interval as the first voltage setting of energy storage device Umax:
For a system with a super capacitor and fuel cell, the corresponding charging capacity is the voltage value at 90%, determine the voltage value at the said 90% as the first voltage setting of energy storage device Umax, For battery and fuel cell being used as a power system (for example, vehicle), the corresponding charging capacity is 60%˜80% voltage interval, select any voltage value of the said 60%˜80% voltage interval to be determined as the first voltage setting of energy storage device Umax; For battery (with a poor high current discharging capacity) and fuel cell being used as a power system (for example, vehicle), the corresponding charging capacity is 80%˜90% voltage interval, select any voltage value of the said 80%˜90% voltage interval to be determined as the first voltage setting of energy storage device Umax, For battery and fuel cell being used as a non-power system (for example, a power supply for communication base), the corresponding charging capacity is 50%˜60% voltage interval, select any voltage value of the said 50%˜60% voltage interval to be determined as the first voltage setting of energy storage device Umax to maintain a super long service life.
B. In case of a system with energy recovery, the steps to determine the first voltage setting of energy storage device Umax are shown below:
Step B 1 : Determine the system limit charging current, specifically, under the energy recovery working condition in which the system uses a medium limit (for example, a forklift brakes with the heaviest weight lifted, the highest slope (a permissible slope circumstance for forklift), accelerating down a slope to the end thereof), use batter first to make a braking action to obtain the system current, time data from braking until its end, as shown in FIG. 7 , the negative current of that system is the charging current, calculate the average of that charging current as the system limit charging current;
Step B 2 : Determine the limit voltage Ulim, specifically, judge if the highest limit of load protection voltage is greater than the charging protection voltage of the energy storage device; if the judgment result is positive, then set the limit voltage Ulimit as equal to the charging protection voltage of the energy storage device; if the judgment result is negative, then set the limit voltage Ulimit as equal to the highest limit of load protection voltage;
Step B 3 : Determine according to the following formula (2) the expected DCDC converting unit output current Iexpect:
Iexpect
=
Irated
·
Edcdc
U
lim
Where, Irated is the rated output power of the fuel cell, Edcdc is the efficiency of the DCDC converting unit;
Step B 4 : Inquire the test curves with different charging currents and charging capacities; according to the constant current charging curve that the system limit charging current corresponds to, obtain the corresponding charging capacity when charging to the limit voltage; according to that charging capacity, find the corresponding voltage value on the constant current charging curve that the expected DCDC converting unit output current Iexpect corresponds to, the said corresponding voltage value is the first voltage setting of energy storage device Umax, as shown in FIG. 8 ; in which, the technical people in this field understand that the test curves with different charging currents and charging capacities (AH) can be obtained from the manufacturer.
Step B 5 : According to the energy recovery working condition in which the system uses the time limit, conduct actual testing by using the system controlled by the first voltage setting of energy storage device Umax, correct the first voltage setting of energy storage device Umax so that the actually measured highest voltage is slightly lower than the limit voltage Ulim;
Step B 6 : Correct the capacity of the energy storage device, specifically, according to the relational curve between the charging capacity/rated capacity and cycle times of energy storage device, or the relational curve between the discharging capacity/rated capacity and cycle times thereof, inquire the charging capacity/rated capacity ratio after multiple cycles, and then take the product of the first voltage setting of energy storage device Umax and charging capacity/rated capacity ratio as corrected first voltage setting of energy storage device Umax, for example, as shown in FIG. 9 .
Where, as a high current flows past, cable, contactor, cable connection, etc. may cause a voltage drop, which must be corrected. According to the energy recovery working condition in which the system uses time limit, conduct actual testing by using the system controlled by the first voltage setting of energy storage device Umax.
If the actually measured highest voltage is higher than the limit voltage, then a correction must be made.
If the actually measured highest voltage is much lower than the limit voltage, then a correction can also be made.
The correcting formula is:
Modified first voltage setting of energy storage device U max=the first voltage setting of energy storage device U max*before correction(limit voltage−the first voltage setting of energy storage device U max before correction)/(actually measured highest voltage−the first voltage setting of energy storage device U max).
By using the approximation method, gradually change the first voltage setting of energy storage device Umax to conduct testing, after measurement, the corrected first voltage setting of energy storage device Umax is obtained.
As shown in FIG. 10 , according to the relational curve between the charging capacity/rated capacity and cycle times of the energy storage device (that curve is provided by the supplier), inquire the charging capacity/rated capacity ratio after multiple cycles. As the discharging capacity is proportionate to the charging capacity, the relational curve between discharging capacity/rated capacity and cycle times can be used for replacement.
The corrected first voltage setting of energy storage device U max=the charging capacity/rated capacity of the corrected first voltage setting of energy storage device U max*obtained in Step B6.
What the system uses is the charging capacity/rated capacity after the energy storage device makes 1000 times of rated cycles.
Through that step, the influence of reduction in battery capacity on the system is pre-corrected, as a result, it is ensured that it is not necessary to correct in long system service the control parameters (the first voltage setting of energy storage device Umax). But the existing system with a SOC calculation mode has to estimate regularly the actual energy storage device capacity, reset the BC (energy storage device capacity) value in the system to improve the accuracy of SOC calculation.
C. The steps to determine the first current setting of DCDC Isetmin are shown below:
Step C 1 : Determine the lowest consumption current of the auxiliary system Is, specifically, use the obtained system controlled by the first voltage setting of energy storage device Umax to make the system be in an idle condition, after the system becomes stable, the consumption of the auxiliary system reduces to the minimum value, measure the current of the auxiliary system at this time, which is the lowest consumption current; where the lowest consumption current of the auxiliary system means the current consumed by the auxiliary system to maintain the minimum output of the auxiliary system and at which the fuel cell can be maintained to work.
Step C 2 : take the product of the lowest consumption current of the auxiliary system and coefficient K as the first current setting of DCDC Isetmin, where coefficient K is less than 1.
Preferably, coefficient K is 0.6, the reason is that the following factors have to be considered in actual setup:
a. The coefficient is to be several times higher than the measurement accuracy of the DCDC current measurement device.
b. The problem of drifting of the current sensor in long-term operation is to be considered, that the measurement value of the current sensor is higher than the actual current will not influence system operation; that the measurement value of the current sensor is lower than the actual current will influence system operation.
By considering the above factors comprehensively, in the preferable cases, coefficient K=0.6. That method need not rely too much on the accuracy, zero point, reaction speed, etc. of the sensor.
D. The steps to determine the maximum current setting that DCDC allows to output Imax are shown below:
Step D 1 : Determine according to the following formula (3) the maximum current setting that DCDC allows to output Imax:
I
max
=
Irated
·
Edcdc
U
max
E. The steps to determine the second voltage setting of energy storage device Umin are shown below:
Step E 1 : Determine according to the following formula (4) the minimum charge capacity Cmin:
C min= C −( Is−I set min )· T
Where C is charging capacity, Is is the minimum consumption current of the auxiliary system, T is time, the said charging capacity is on the charging capacity and charging voltage curve of constant current charging with the maximum current setting that DCDC allows to output Imax as the current, find that the charging capacity that the first voltage setting of energy storage device Umax corresponds to for the charging voltage, the said time is set according to the response speed required by the system;
Step E 2 : According to the minimum charge capacity Cmin, find the charging voltage that the minimum charge capacity Cmin corresponds to on the charging capacity and charging voltage curve of constant current charging with the maximum current setting that DCDC allows to output Imax as the current, select that charging voltage as the second voltage setting of energy storage device Umin.
Further, determine through the following method the permissible DCDC current deviation value Ipermissible:
DCDC current deviation value=the DCDC converting unit output current controlled by system controller−the actual output current of DCDC converting unit.
Factors to be considered in actual setup:
a. The coefficient is to be several times higher than the measurement accuracy of DCDC current measurement device.
b. The problem of drifting of the current sensor in long-term operation is to be considered, that the measurement value of the current sensor is higher than the actual current will not influence system operation; that the measurement value of the current sensor is lower than the actual current will influence system operation.
Therefore, that value is preferably set as 5 A in this embodiment example.
Next, the specific applications of the said fuel cell mixed power supply energy management method is described through 4 different types of working conditions:
When the fuel cell power is used in vehicle work through the system that DCDC converting unit output is mixed with the energy storage device (the system as shown in FIG. 1 ):
Working condition 1: When the connected load (vehicle) operates at certain conditions (such as high power, startup), the required system current is higher than the DCDC converting unit current output, the insufficient current part is obtained from the energy storage device, at this time, the energy storage device voltage will inevitably decrease gradually. To avoid that the energy storage device voltage is lower than the minimum working voltage of the energy storage device resulting in the system being unable to operate, when the energy storage device voltage is lower than a certain value (the second voltage setting of energy storage device Umin), the system controller gradually increases the DCDC converting unit output current to make the energy storage device output current reduce gradually and the energy storage device voltage increase gradually. When operating at a high power continuously, the DCDC converting unit output current will increase until reaching the maximum current setting that DCDC allows to output.
Thus, through changing the output current of the DCDC converter, the effective and rational distribution of the energy required by the system is accomplished between the fuel cell and energy storage device.
Working condition 2: When the operating condition is changed so that the connected load (vehicle) operates at certain conditions (such as low power operation, idle speed), the required system current is less than the current output of DCDC converting unit, the DCDC converting unit charges the energy storage device, at this time, energy storage device voltage will inevitably increase gradually. To avoid that the energy storage device voltage exceeds the charging protection voltage of the energy storage device resulting in system stopping operation, when the energy storage device voltage reaches the set value (the first voltage setting of energy storage device Umax), the system controller gradually reduced the DCDC converting unit output current to make the energy storage device output voltage reduce gradually; when the energy storage device voltage is lower than the set value (the first voltage setting of energy storage device Umax), the DCDC converting unit output current will no longer change. At this time, that DCDC converting unit output current may still be higher than the system current that the system requires to maintain operation at a low power or idle speed, then the system repeats the above step; until the DCDC converting unit output current is less than the system current, the insufficient current part is obtained from the energy storage device, at this time, enter again into the case of above working condition 1.
Thus, through changing the output current of the DCDC converter, the replenishment of the electric quantity lost by the energy storage device is accomplished.
Working condition 3: When the connected load (vehicle) changes suddenly in some condition (from operation at a high power to operation at a low operation), the required system current reduces, the DCDC converting unit output current also reduces with it, at this time, the DCDC converting unit output current controlled by the system controller is higher than the actual output current of the DCDC converting unit. When the DCDC current deviation value is greater than or equal to the permissible DCDC current deviation value, the system controller controls to reduce at a fastest speed the DCDC converting unit output current until that output current is the first current setting of DCDC Isetmin, what that first current setting of DCDC Isetmin is less than the minimum power consumption of the system auxiliary components, current is obtained from system; at this time, the system control jumps to the case of above working condition 1. When the DCDC current deviation value is less than the permissible DCDC current deviation value, at this time, the system control enters into the case of above working condition 2.
The purpose to set up working condition 3: When a vehicle operates practically, it may change back to operation at a high power after turning from operation at a high power to operation at low power, the system may suddenly output a high current again; at this time, if working condition 3 is not set up to reduce the DCDC converting unit output current controlled by the system controller, then when the system outputs a high current suddenly, as the DCDC converting unit output current controlled by the system controller is higher than the actual output current of the DCDC converting unit, power may be obtained first from the DCDC converting unit, resulting in an impact on the fuel cell.
In this way, by setting the output current of the DCDC converter, the distribution strategy at the time when the system adds load suddenly is ensured: the energy storage device outputs first, the fuel cell follows.
Working condition 4: When a vehicle brakes, the vehicle with an energy feedback function will turn the energy resulting from braking into electric energy and feed it back to the power supply system; for a fuel cell system, such a condition is external current input into it, that current is input into the energy storage device, at the same time, the current outputted by the DCDC converting unit is also input into the energy storage device, this may make the energy storage device voltage increase sharply to the protection voltage and trigger shutdown, as a result, the energy resulting from braking can not be recovered to lead to the vehicle being out of control; therefore, when braking, it is necessary to control and reduce the current outputted by the DCDC converting unit first. To avoid that the energy storage device voltage exceeds the protection voltage of the energy storage device, when the energy storage device voltage reaches the set value (the first voltage setting of energy storage device Umax), the system controller controls to reduce gradually the DCDC converting unit output current, until that output current is the current setting of DCDC 1 . When that value is less than the minimum power consumption of the system auxiliary components, current is obtained from the system. After braking is over, the system controls to jump to the case of working condition 1.
The reason that a compact structure as shown in FIG. 1 can be designed for the said forklift fuel cell supply system is mainly due to adopting the compact type fuel cell supply system as shown in FIG. 2 .
FIG. 2 is the schematic diagram of the structure of the compact type fuel cell supply system of the first embodiment example provided according to this invention, in this embodiment example, the said compact type fuel cell supply system consists of fuel cell 1 , DCDC converting unit 2 , contactor 3 , energy storage device 4 , power supply output end 5 , operation control unit 6 , controller 7 , auxiliary system 8 , in which the said contactor 3 is a normal open type high-current contactor, the said DCDC converting unit 2 includes DCDC converter 21 and high-power diode 22 connecting with it.
Specifically, the output end of the said fuel cell 1 connects the input end of the said DCDC converting unit 2 , DCDC converting unit 2 connects through the said contactor 3 the said energy storage device 4 , the output end of the said DCDC converting unit 2 also connects the said power supply output end 5 and the high-power auxiliary component 80 that the said auxiliary system 8 contains, the port of the said energy storage device 4 connects through the said contactor 3 the said power supply output end 5 and auxiliary system 8 , the said operation control unit 6 connects respectively the said energy storage device 4 , DCDC converting unit 2 , controller 7 , the said controller 7 connects respectively the said fuel cell 1 , DCDC converting unit 2 , the control end of contactor 3 , energy storage device 4 and auxiliary system 8 .
In this embodiment example, the positive pole of the output end of the said DCDC converting unit 2 connects through the said contactor 3 the positive pole of the said energy storage device 4 , the negative pole of the output end of the said DCDC converting unit 2 connects through the said contactor 3 the negative pole of the said energy storage device 4 , the positive pole of the said energy storage device 4 connects through the said contactor 3 the positive pole of the said power supply output end 5 and the positive pole of auxiliary system 8 , the negative pole of the said energy storage device 4 connects directly the negative pole of the said power supply output end 5 and the negative pole of auxiliary system 8 ; and in a variation of this embodiment example, the difference from the first embodiment example as shown in FIG. 1 is that in this variation, the change of the said contactor 3 in connecting position is: the said contactor 3 is connected between the negative pole of the output end of the said DCDC converting unit 2 and the negative pole of the said energy storage device 4 , and the positive pole of the output end of the said DCDC converting unit 2 and the positive pole of the said energy storage device 4 are connected directly between them, correspondingly, the positive pole of the said energy storage device 4 connects directly the positive pole of the said power supply output end 5 and the positive pole of auxiliary system 8 , the negative pole of the said energy storage device 4 connects through the said contactor 3 the negative pole of the said power supply output end 5 and the negative pole of auxiliary system 8 . The technical people in this field understand that the two connection modes for contactor 3 as described in this natural paragraph can both realize “DCDC converting unit 2 connecting through the said contactor 3 the said energy storage device 4 ” and “the port of the said energy storage device 4 connecting through the said contactor 3 the said power supply output end 5 and auxiliary system 8 ”.
The said auxiliary system 8 consists of air supply system, cooling system, hydrogen system, hydrogen safety system, the said high-power auxiliary component 80 refers to a high-power component in the auxiliary system (for example, fan, pump, heat dissipation fan). The technical people in this field can refer to the existing technology to accomplish the said auxiliary system 8 and its high-power auxiliary component 80 . No unnecessary detail is to be given here.
The said operation control unit 6 is used to receive operation signals and supplies power for the said controller 7 and DCDC converting unit 2 , the said controller 7 is used to receive the operation instructions generated by the said operation control unit 6 according to the said operation signals and control according to the said operation instructions the said contactor 3 , DCDC converting unit 2 , auxiliary system 8 , the said controller 7 is also used to measure the state parameters of the said fuel cell 1 , measure the state parameters of the said energy storage device 4 , measure the state parameters of the said auxiliary system 8 and receive the state data of the said DCDC converting unit 2 . The said DCDC converter 21 consists of CAN communication module, input voltage measurement module, input current measurement module, output voltage measurement module, output current measurement module. Preferably, DCDC converter 21 can control according to the communication data of the CAN communication module the specific numerical values of the output current, voltage; also outputs through the CAN communication module such data as input voltage, input current, output voltage, output current, etc. The state data of the said DCDC converting unit 2 includes DCDC input current, DCDC input voltage.
The said controller 7 is a controller with an integrated design, which is equivalent to the scattered fuel cell controller, whole vehicle controller, battery energy management system in the invention patent application of China with patent application number “200610011555.1”; further specifically, the said controller 7 can consist of energy management unit, fuel cell control unit, energy storage device monitoring unit, hydrogen safety monitoring unit, system failure monitoring unit and startup control unit.
More specifically, as shown in FIG. 2 , the output end of the said fuel cell 1 connects the input end of the said DCDC converter 21 , the positive pole of the output end of the said DCDC converter 21 connects the positive pole of the said high-power diode 22 , negative pole of the said high-power diode 22 connects through the said contactor 3 the said energy storage device 4 , the said DCDC converter 21 connects the said controller 7 and is controlled by the said controller 7 , the said DCDC converter 21 connects the said operation control unit 6 and receives the power supplied by the said operation control unit 6 . And in a variation of this embodiment example, the difference from the first embodiment example as shown in FIG. 2 is that in this variation, the positive pole of the output end of the said fuel cell 1 connects the positive pole of the said high-power diode 22 , the negative pole of the said high-power diode 22 connects the positive pole of the input end of the said DCDC converter 21 , the negative pole of the output end of the said fuel cell 1 connects directly the negative pole of the input end of the said DCDC converter 21 , the output end of the said DCDC converter 21 directly connects through the said contactor 3 the said energy storage device 4 .
Further, in this embodiment example, the said compact type fuel cell supply system also consists of monitoring display 91 , ON and OFF button 92 , remote control 93 , emergency stop button 94 , in which the said monitoring display 91 connects the said controller 7 , the said ON and OFF button 92 connects respectively the said operation control unit 6 and controller 7 , the said remote control 93 connects in a radio mode the said operation control unit 6 , the said emergency stop button 94 connects the said operation control unit 6 . As shown in FIG. 1 , when the said ON and OFF button 92 or remote control 93 gives a startup signal, the said operation control unit 6 supplies power to the said controller 7 , the said controller 7 outputs a control signal to the contactor used as a switch to make it close, the said energy storage device 4 supplies power through the said contactor 3 to the said high-power auxiliary component 80 , in the said auxiliary system 8 , except the said high-power auxiliary component 80 , other devices (for example, hydrogen system, hydrogen safety system) are supplied by the said controller 7 , at the same time, the said controller 7 outputs signals to all modules constituting the said auxiliary system 8 to start the said fuel cell 1 ; after starting, the said contactor 3 maintains the state of connection at all times. By adopting this starting mode, it is not necessary to use additionally configured auxiliary battery and auxiliary DC/DC converter for charging, as a result, parts and components and corresponding lines are reduced, system reliability is improved, space is saved, system volume and costs are reduced.
In a preferable case of this embodiment example, as shown in FIG. 3 , the said high-power diode 22 is placed on the heat dissipation passage of the said DCDC converter 21 , this can use the air discharged from the air duct 2101 by the heat dissipation fan 2102 contained by the said DCDC converter itself to dissipate heat from the said high-power diode 22 , as a result, the heat dissipation fan on the heat dissipater 2201 (i.e. aluminum fin) for the said high-power diode is saved, the volume of heat dissipater is reduced, energy is saved, at the same time, the line to supply power to that heat dissipation fan is also saved. The said operation control unit 6 changes the electric connection state with the said DCDC converting unit and controller 7 according to the startup operation signal received. Thus, the said controller 7 is in an operation condition only when the system is working and will not lead to the problem of high system energy consumption due to being always in an operation condition.
Next, the system working principle is described through a preferable embodiment of this invention. Specifically, When the system is not started, the said operation control unit 6 and the said controller 7 , DCDC converting unit 2 establish no electric connection state between them. When the button of the said remote control 93 or the said ON and OFF button 92 is depressed, the said operation control unit 6 and the said controller 7 , DCDC converting unit 2 establish an electric connection between them, the said energy storage device 4 supplies power through the said operation control unit 6 to the said controller 7 , the output signal of the said controller 7 drives the said contactor 3 to get connected, the said energy storage device 4 supplies power through the said contactor 3 to the said high-power auxiliary component 80 , in the said auxiliary system 8 , except the said high-power auxiliary component 80 , other devices (for example, hydrogen system, hydrogen safety system) are supplied by the said controller 7 , at the same time, the said controller 7 outputs working signals to all modules constituting the said auxiliary system 8 to start the said fuel cell 1 ; the said fuel cell 1 outputs power to the said DCDC converting unit 2 , the said controller 7 controls according to the received state data signals of the said fuel cell 1 , energy storage device 4 , DCDC converting unit 2 the said DCDC converting unit 2 output current; under the normal system working condition, the output voltage of the said DCDC converting unit 2 is higher than the output voltage of the said energy storage device 4 , the output current of the said DCDC converting unit 2 is output through the said power supply output end 5 to the small vehicle drive system carrying the said fuel cell supply system to drive the small vehicle to work, at the same time, the said DCDC converting unit 2 charges the said energy storage device 4 , supplies power to the said high-power auxiliary component 80 , operation control unit 6 ; when a small vehicle is in a high-power driving condition, the said power supply output end 5 needs to output high power, high currency, at this time, the said DCDC converting unit 2 output current is not sufficient to satisfy the requirements, the said energy storage device 4 will output current together with the said DCDC converting unit 2 to the small vehicle driving system carrying that fuel cell supply system through the said power supply output end 5 to drive that small vehicle to maintain the high-power driving condition; when the small vehicle is in a braking condition, the power energy recovered by the brake charges through the power supply output end the energy storage device.
When it is necessary to start the system, just depress the button of the said remote control 93 or the said ON and OFF button 92 , in the meantime that the said operation control unit 6 and the said controller 7 , DCDC converting unit 2 establish an electric connection, the said operation control unit 6 outputs a switch signal to the said controller 7 , the said controller 7 , after receiving the switch signal, outputs a signal to maintain power supply to the said operation control unit 6 , so that the said operation control unit 6 and the said controller 7 , DCDC converting unit 2 maintain an electric connection state; at the same time, the said controller 7 also drives the indicator light of the said ON and OFF button 92 to become on to prompt system starting; at this time, the button of the said remote control 93 or the said ON and OFF button 92 can be released.
When it is necessary to close the system, depress again the button of the said remote control 93 or the said ON and OFF button 92 , the said operation control unit 6 outputs a switch signal to the said controller 7 , the said controller 7 , after receiving the switch signal, controls the indicator light of the said ON and OFF button 92 to blink (prompting switching off, at this time, the button of the said remote control 93 or the said ON and OFF button 92 can be released), the said controller 7 simultaneously controls the said auxiliary system 8 to stop working, and then stops outputting the signal to maintain power supply to the said operation control unit 6 , so that the electric connection of the said operation control unit 7 and the said controller 7 , DCDC converting unit 2 is disconnected; the whole system stops working.
When the said emergency stop button 94 is depressed, the electric connection between the said operation control unit 6 and the said controller 7 , DCDC converting unit 2 get disconnected quickly to cut off the power supply to the whole system and make the system stop working.
The said monitoring display 91 gets power, communication data from the said controller 7 , displays the system condition, failure information, etc. on the screen.
The embodiment examples of this invention are described above. What needs understanding is that that this invention is not limited to above specific embodiments. The technical people in this field can make various variations or modifications with the Claim, and this does not influence the essential contents of this invention. | This invention provides a kind of mixed power supply energy management method for fuel battery, including the following steps: initialization; control the output current of DCDC converting unit according to the measured energy storage device voltage and the actual current outputted by the DCDC converting unit, respond to the energy need resulting from load condition change and at the same time ensure the energy storage device to be in a best charge state; send a current setting instruction to the DCDC converting unit. This invention does not adopt the SOC calculation mode any more, the system no longer relies on the accuracy, reliability of current sensor; and this invention is strongly compatible, highly reliable, strongly practical and stable in output voltage, with the same system being applicable to more vehicles of different models (forklift) and parameter correction being unnecessary. By correcting battery capacity decrease in advance through setting up parameters in advance, the long-term reliability of the system is ensured. | 8 |
FIELD
[0001] This invention relates to connections for tubular structures suitable for use as handrails, and more particularly to a hinge and lock that can be attached to a standard handrail to form, together with an arm in the form of a short tubular rail component, a pivotally openable gate that opens and closes the handrail where it is necessary to have a closeable access through the handrail.
BACKGROUND
[0002] Usually, handrails consist of horizontally and vertically arranged and connected metal hollow tubes of a selected cross-section, frequently circular. The handrails may be supported on a wall by horizontal mounting posts or may be supported from a floor by posts or stanchions, which are spaced from one another. The stanchions and wall mounting posts are interconnected by lengths of generally horizontal hollow tubing constituting the handrail, but the handrail may also be inclined or vertical along staircases or ladders. Handrails are installed to improve the safety of a specific site and to serve as a support in walking and climbing. In many industrial and civil buildings, handrails are an indispensable installation required by safety regulations.
[0003] In some places, it is necessary to make available an opening in the handrail to enable access to an area on the other side of the handrail. In many cases, those openings are simply left free as they do not need to be further secured (for example, when a handrail along a sidewalk is discontinued and restarted again to create an opening for accessing a crosswalk). In other sites, however, such openings reduce the safety of the installation, particularly where a handrail separates two areas situated at different levels. In those cases, it is desirable to secure the opening by creating some barrier or gate so the handrail constantly serves its safety purpose in its full length, but can be opened when needed.
[0004] Such gates within handrails can be commonly found in many manufacturing buildings, in the construction industry and in the marine industry, of which the field of recreational yachting is important. When an opening in the handrail is essential for a staircase, construction elevator, permanent ladder, or for boarding a vessel, some previous rather unsatisfactory designs for an openable section of the handrail that would maintain the structural integrity of the handrail have been proposed. It is desirable that any gate when closed, form an essentially uninterrupted continuum with the adjoining portions of the handrail, so that one's hand can pass along the gate and adjoining railing without impediment, and so that little or no risk of catching a glove or a sleeve occurs when gripping the railing in the gate portion or adjoining portions. It is further desirable that the gate be secure when closed. It is further desirable that all connecting parts, such as hinges, clasps and locks, be simple, reliable, easily manufactured, and strong enough for the purpose. Unfortunately, previously known gate arrangements have fallen short of one or more of these objectives.
[0005] In the industry, closing of a gate providing a temporarily open section of a handrail is typically achieved by mounting a simple hinge at one side of the gate bar or tube. The hinge connects one end of the stationary handrail with a sectional pivoting arm constituting the gate bar or tube, usually moving in a ninety degree angle. The arm is long enough to reach the other side of the temporary opening in the handrail, where it is usually received by a mating saddle-type receptacle attached to a horizontal part of the adjoining stationary handrail. Because the closed pivoting arm is not secured or locked by any means, but simply rests in the saddle and can be accidentally opened by bumping into it from the bottom, the gate constitutes a potentially hazardous section of the handrail. In addition, the hinge attachment, which represents the only means of permanent connection of the arm, can be easily damaged when a force is applied to the closed pivoting arm from its side.
[0006] To prevent accidental opening of such a conventional gate, holes are often drilled through the pivoting arm and through the handrail saddle, and removable bolts or pins are inserted into the holes to ensure that the closed arm does not open by accident nor move when a generally horizontal force is applied to it. However, obtrusive elements, such as exposed bolt heads and pins, reduce the overall safety of the handrail, as they can cause hand injuries when a person suddenly grips the handrail. Accordingly, although the conventional design of the mountable pivoting arm is advantageous to a limited extent, the methods of attachment and locking of the arm to the stationary handrail present potential opportunities for improvement.
[0007] For marine use, and typically in the construction of handrails for recreational yachts and the like, openings in the handrails, if secured at all, are commonly secured by mounting a stainless steel chain and hook, or a plastic coated stainless steel wire cable and hook, to stanchions or posts or terminating stationary rail elements at the ends of the opening. Alternatively, movable wooden handrail gates with protruding conventional hinges and expensive hardware may span the opening. Devices such as cables or chains do not retain the structural integrity of the boat handrail and are not safe in harsh weather conditions. Additionally, for yachting use, the overall aesthetic appearance of the handrail structure is an important issue, and current designs of hook and cable do not entirely satisfy the expected demands of boat owners for aesthetically pleasing designs.
[0008] Therefore, despite the obvious need for a safe and convenient handrail gate design, there has not heretofore been any completely satisfactory solution to the problem of providing a simple gate section in the handrail that would retain the structural integrity of the original handrail and at the same time be both aesthetically pleasing and safe.
[0009] It is apparent that the objectives of structural integrity and aesthetic appeal can be met by providing a handrail gate having the same cross-section as the stationary portion of the handrail. The problem is to provide a hinge on one end of the gate and a lock at the other end of the gate that maintain a uniform cross-section throughout the handrail when the gate is closed, even at points of connection. Such hinge and lock should be inexpensive, safe, easy to manufacture, install and use, aesthetically pleasing, durable and solid enough to resist occasional impacts accidentally caused by users without being displaced or sufficiently damaged to interfere with satisfactory operation.
SUMMARY
[0010] An object of the present invention is to provide a combination of a hinge and lock for interconnecting a standard tubular handrail (typically but not necessarily made of round tubing) with a pivoting arm to form a gate within the handrail that retains the structural integrity of the original handrail, and is safe and aesthetically pleasing.
[0011] Another object of the present invention is to provide a hinge and lock mountable on or connectable to a standard tubular handrail and on or to a mating pivotable gate arm, that are easy to manufacture, install and use, and that are at the same time durable and reliable.
[0012] Another object of the present invention is to provide a hinge as aforesaid that enables pivoting of the gate arm through an angle up to about 180°.
[0013] Another object of the present invention is to provide a gate lock as aforesaid that when in the closed position resists longitudinal tensional forces across the gate opening.
[0014] The hinge and the lock of the present invention can be used independently of one another.
[0015] The hinge and the lock of the present invention are substitutes for the hinge and lock described in Applicant's previously filed Canadian patent application Ser. No. 2,314,839, filed on 2 Aug. 2000. For convenience of description, some of the content of Applicant's previously filed Canadian patent application is repeated in this application.
[0016] The hinge and lock may be installed and used in various orientations, but for ease of explanation in this specification, including the claims, the hinge and lock are referred to as if they are in the closed position when installed on a horizontal handrail. More particularly, the following words have the following meanings:
1. “longitudinal” refers to movement and directions substantially parallel to the longitudinal axis of the handrail and gate arm when the gate arm is in the closed position; and 2. “lateral” refers to side-to-side movement and directions, that is, those that are substantially horizontal and substantially perpendicular to the longitudinal axis of the handrails and gate arm when the gate arm is in the closed position.
[0019] The gate according to the invention is particularly suitable for use with an elongate handrail or the like that has one or more open gateways that need to be locked (latched) closed from time to time. Each gateway exists between two spaced terminals of the handrail, one terminal on either side of the gateway.
[0020] Preferably, the gate includes a pivotable gate arm, preferably having the same profile in cross-section as the handrail, and pivotally movable from a closed locked position to a fully open position at which the gate arm lies next to the adjoining stationary handrail. Even though the gate arm itself may be substantially uniform along its length or at least longitudinally symmetrical, the two ends of the gate arm may conveniently be referred to as the gate hinge end and the gate lock end, since one end of the gate arm is fastened to a hinge for hingedly connecting the hinge end of the gate arm to one terminal, conveniently referred to as the handrail hinge terminal, and the other end of the gate arm is fastened to one component of a two-component lock. The other lock component is fastened to the other terminal of the handrail, conveniently referred to as the handrail lock terminal. The two lock components matingly engage one another as the lock end of the gate arm moves into alignment with the lock terminal of the handrail.
[0021] The two lock components are respectively provided with mating components of a lock that is operative to releasably secure the gate arm to the handrail when the lock end of the gate arm is aligned with the neighbouring lock terminal of the handrail, and the mating lock components have come into engagement with one another. A release means such as a depressable projecting button is provided for releasing the two lock components from one another after they have locked together.
[0022] The lengths of the gate arm and of the hinge and lock components are selected so as to provide a substantially uninterrupted continuum of the entire handrail structure (including the gate arm), when the gate arm is in the closed position. To optimize the structural continuity, the peripheral profile of the hinge and of the lock components are selected to be identical to or at least to merge with the peripheral profile of the gate arm and the handrail.
[0023] Handrails are typically made of hollow tubing. Round tubing is the most common and generally the least expensive to manufacture. According to the preferred embodiment of the invention, the hinge and lock components are provided with stubs insertable into the tubing, preferably in a tight fit or at least a snug fit. Auxiliary securing means are also preferably provided to fasten the hinge and lock elements in place during normal use.
[0024] In accordance with the present invention, there is also provided a lock having two mating elements referred to herein as the active lock component and the passive lock component. The active lock component has a plug that projects substantially perpendicular to the longitudinal axis of the handrail or gate arm, as the case may be, to which it is attached when the active lock component is installed. The passive lock component has a socket sized and shaped for receiving the plug. The socket has longitudinally-extending side walls so as to impede lateral movement of the active lock component relative to the passive lock component when the plug is in the socket; and a laterally-extending end wall so as to impede longitudinal movement of the active lock component relative to the passive lock component when the plug is seated in the socket.
[0025] The lock includes means for releasably securing the plug within the socket so as to releasably secure the passive and active lock components one to the other. Preferably, the means for releasably securing the plug within the socket comprises a depressable button projecting from the plug and a hole in the socket through which the button projects when the plug is seated within the socket and the active and passive lock components are in the closed position.
[0026] Accordingly, the plug and socket, and button and socket, interlock so as to resist any motion of the active lock component relative to the passive lock component when the lock components are in the closed position.
[0027] Preferably, the active and passive lock components include surfaces on one or both lock components configured to guide the plug and socket into proper alignment during movement of the lock components to the closed position. Preferably, these guiding surfaces include surfaces that tend to guide the lock components longitudinally such as where the disengaged lock components longitudinally overlap too much, or not enough, for proper interlocking of the plug and socket. Further, these guiding surfaces also preferably include a surface or surfaces tending to guide the lock components laterally, so as to laterally align the lock components during closing. Laterally-guiding surfaces may be desirable when there is sufficient lateral play in the gate arm to permit lateral misalignment of the lock components.
[0028] Further, the laterally-guiding surfaces also preferably include a surface on the plug, or within the socket, that guides the plug within the socket during closing such that the button is pushed against a side wall of the socket so as to depress the button. This button-depressing laterally-guiding surface preferably comprises a planar surface on the side of the socket opposite the hole The planar surface is inclined relative to the plane defined by the opening and closing pivotal movement of the gate arm such that when the plug contacts the planar surface during closing the planar surface guides the plug to move simultaneously laterally towards the hole and downward, so as to depress the button and move it towards alignment with the hole.
[0029] The peripheral profile of the lock components are preferably selected to be identical to, or at least to merge with, the peripheral profile of the gate arm and the handrail, when the lock components are in the closed position. When the gate arm and handrail are made from round tubing, the visible portions of the closed lock components are configured so as to combine to form a cylindrical peripheral profile of substantially the same diameter as the gate arm and handrail. Preferably the overlapping visible portions of the lock components are each semi-cylindrical. The semi-cylindrical portion of the passive lock component contains the socket and hole. The plug projects from the semi-cylindrical portion of the active lock component. The visible portions of the lock components may also each comprise a cylindrical collar, integral with the respective semi-cylindrical portion and adjoining the relevant handrail or gate arm when the relevant lock component is installed.
[0030] For use with handrails and gate arms made from hollow tubing, the lock components preferably each have a stub portion for insertion into the gate lock end or the handrail lock terminal, as the case may be, preferably in a snug or tight fit, so as to attach the lock components to the handrail and gate arm.
[0031] For use with handrails and gate arms made from round hollow tubing, each stub preferably is substantially cylindrical and has an external diameter the same as or slightly smaller than the internal diameter of the tubing. Preferably, each stub is hollow and is provided with circumferentially-spaced longitudinally-extending slits to permit the stub to be slightly compressed to facilitate insertion. Preferably the stub has one or more retainer wedges, each having a relatively-long gently-inclined top surface that permits easy insertion of the stub and a short end surface that forms a sharp corner with the gently-inclined surface, which sharp corner engages the inner wall of the tubing so as to resist removal of the stub. Preferably each stub is provided with bevelled or chamfered distal edges to facilitate the initial insertion of the stub into the tubing.
[0032] Each stub is also preferably additionally secured within the relevant handrail or gate arm by a fastener such as a headless screw. The fastener is preferably installed by drilling a hole through the handrail or gate arm, and the relevant stub after the stub has been inserted into the handrail or gate arm. If required for the particular fastener, the hole may then be tapped with the appropriate threads and the fastener, such as a headless screw or other screw, is then screwed into position. The fastener need not be a headless screw and may be a regular machine screw with a head, a rivet or a variety of other fasteners.
[0033] In accordance with the foregoing objectives, there is provided an improved hinge for hingedly connecting the handrail hinge terminal to the gate hinge end. The hinge includes two connectors and a link, each connector being separately pivotally attached to the link. Each connector is attached to the link such that each connector may pivot roughly 90° relative to the link, such that the connectors can pivot through roughly 180° relative to each other.
[0034] Preferably, the link and connectors are configured such that a portion of each connector abuts the link when the gate arm to which the hinge is attached is in the closed position so as to impede pivotal movement of the gate arm in the direction opposite the opening direction. As well, a portion of each connector abuts the link when the gate arm to which the hinge is attached is pivoted to a fully open position roughly 180° from the closed position, such that the gate arm is substantially parallel to the adjoining handrail. In this way the hinge impedes pivotal movement of the gate arm beyond roughly 180° between the closed position and the fully open position. This structural arrangement lends to the hinge a motion-limiting characteristic permitting the gate arm to pivot from the closed position to the fully open position only in one general direction, usually upward. Accordingly, in the closed position, the gate arm will tend to remain coaxial with the stationary handrail, and will tend not to collapse or pivot downwardly even if it is not supported at its distal end.
[0035] Preferably, the connectors are essentially identical one to the other and each comprises a clevis having two spaced-apart fingers and a web spanning the fingers at the base of the fingers, the clevis fingers defining a clevis gap, with the clevis gaps being of substantially identical widths. Preferably, the link is a generally-rectangular parallelepiped interposed between the clevis fingers of each connector and pivotally connected to each connector by a pin through aligned holes in the link and the relevant connector. The link is sized for insertion into the clevis gaps such that the width of the link is selected to be slightly less than the width of the clevis gap. Preferably, a portion of the web of each connector abuts a portion of the adjoining end of the link when the gate arm is in the closed position so as to impede pivotal movement of the gate arm in the direction opposite the opening direction. Preferably, a portion of the web of each connector abuts the upper surface of the link when the gate arm is in the fully open position so as to impede pivotal movement of the gate arm beyond roughly 180° from the closed position. Preferably, the portions of the webs and link that abut when the gate arm is in the closed position are substantially planar surfaces that are substantially perpendicular to the longitudinal axis of the gate arm and handrail. Alternatively, the link ends and webs may be configured such that the abutting surfaces are substantially parallel to, or inclined relative to, the longitudinal axis of the gate arm and handrail.
[0036] Alternatively, the link may include two link devises and each connector may include a projection inserted into, and pivotally attached to, a link clevis, such that the connector projection pivots within the link clevis. Alternatively, neither the link nor the connectors may have a clevis, and the link and connectors may merely overlap side-by-side rather than a portion of one being interposed between fingers projecting from the other.
[0037] The peripheral profile of the hinge is preferably selected to be identical to, or at least to merge with, the peripheral profile of the gate arm and the handrail, when the gate arm is in the closed position. Preferably the link and connectors are configured such that when the gate arm is closed, the distal ends of the devises abut each other and the top and bottom surfaces the link span the gaps defined by the fingers and the web such that the connectors and link form, to the casual observer, one seemingly-solid piece. When the gate arm and handrail are made from round tubing, the outer surfaces of the clevis fingers, and the top and bottom surfaces of the link, are curved and combine, in the closed position, to form a cylindrical peripheral profile of substantially the same diameter as the gate arm and handrail.
[0038] For use with handrails and gate arms made from hollow tubing, the connectors preferably each have a stub portion, essentially identical to the lock component stub portions, for insertion into the gate hinge end or the handrail hinge terminal, as the case may be, so as to attach the connectors to the handrail and gate arm.
[0039] The hinge and lock components can be conveniently manufactured so as not to have any sharp nor obtrusive parts or edges, thus permitting them to constitute an integral part of the hand railing. In order to merge visually and structurally with the rest of the handrail, the hinge and lock may be fabricated out of the same material as the handrail. For visual continuity, they may have the same surface finishing as the handrail. The hinge and lock may be made from diverse materials, such as stainless steel and aluminum.
[0040] A longitudinal series of gate arms, hinges and locks can be arranged together, thereby creating the possibility of opening large handrail sections. A preferred such combination makes use of a central stanchion that is itself hinge-coupled, or otherwise releasably attached, to a bottom pedestal, permitting the entire stanchion, apart from the pedestal, to be: collapsed pivotally downwardly so as to assume a horizontal orientation, or to be removed. The stanchion receives two individually operable gates, themselves coupled by the hinge connections to tubular railings on either side of the stanchion, and locking to the stanchion. By opening both gates and collapsing the stanchion downwardly or removing the stanchion, it would be possible to create a relatively large opening in the handrail. Further, the stanchion and gate arms may be configured such that with the stanchion in its normal upright position, one gate arm may be opened, leaving the other gate arm closed.
[0041] It will be clear that the gate arm need not open only vertically. The hinge and lock may be installed in a variety of orientations as desired.
[0042] The present invention provides many advantages over previously known designs. It offers a simple and ingenious solution to the problem of securing handrail openings (gates). To a great extent, it retains the structural and peripheral integrity of the original handrail, it is durable and strong, and it presents few protrusions or obstructions that can cause injuries. The preferred embodiments provide constraints that prevent or limit motion of the gate arm in undesired directions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] FIG. 1 is a perspective view of a hinge and lock according to a preferred embodiment of the present invention mounted on a standard handrail shown in a closed position.
[0044] FIG. 2 is a partly cross-sectional view along the line I-I in FIG. 1 of a hinge of the type illustrated in FIG. 1 , in the closed position.
[0045] FIG. 3A is a perspective view of the handrail hinge of FIG. 1 , shown in a fully opened position.
[0046] FIG. 3B is a perspective view of the passive component of a lock according to a preferred embodiment of the invention mounted onto the end of the handrail opposite that shown in FIG. 3A and separated from the end of the handrail shown in FIG. 3A by the width of the gate arm. Viewing FIGS. 3A and 3B together, one perceives an open gateway, the gate arm being folded over onto the handrail portion to which it is connected.
[0047] FIG. 4 is a view partly in cross-section along the line II-II in FIG. 3A of a fully opened hinge.
[0048] FIG. 5 is a perspective view showing an embodiment of the active lock component of the present invention.
[0049] FIG. 6 is a perspective exploded view showing the active lock component of FIG. 6 with the parts of the depressable button.
[0050] FIG. 7 is a perspective view showing an embodiment of the passive lock component of the present invention.
[0051] FIG. 8 is an alternative perspective view showing the passive lock component of FIG. 7 .
[0052] FIG. 9 is a partly sectional view of the active lock component showing the parts of the depressable button.
[0053] FIG. 10A is a longitudinal sectional view of an embodiment of the passive and active lock components of the present invention showing first contact between the lock components during closing when the lock components are longitudinally misaligned so as to overlap more than required for full closure.
[0054] FIG. 10B is a lateral sectional view of the passive and active lock components shown in FIG. 10A .
[0055] FIG. 11A is a longitudinal sectional view of the passive and active lock components shown in FIG. 10A , showing first contact between the lock components during closing when the lock components are longitudinally misaligned so as to overlap less than required for full closure.
[0056] FIG. 11B is a lateral sectional view of the passive and active lock components shown in FIG. 11A .
[0057] FIG. 12A is a longitudinal sectional view of the passive and active lock components shown in FIGS. 10A and 11A , showing a position of the lock components during closing, between first contact and the fully closed position.
[0058] FIG. 12B is a lateral sectional view of the passive and active lock components shown in FIG. 12A .
[0059] FIG. 13A is a longitudinal sectional view of the passive and active lock components shown in FIGS. 10A, 11A and 12 A, showing the lock components in the fully closed position.
[0060] FIG. 13B is a lateral sectional view of the passive and active lock components shown in FIG. 13A .
DETAILED DESCRIPTION
[0061] FIGS. 1 through 13 B show a preferred embodiment of the present invention for use with handrails made of round tubing. FIG. 1 shows the hinge 1 , handrail 2 , gate arm 3 and lock 9 in the closed position.
[0062] As shown in FIGS. 1, 2 , 3 A and 4 , the hinge includes a link 5 and two connectors 4 , 6 . The two connectors are substantially identical to each other and are interchangeable. For ease of description, they are named herein according to how they are shown installed in FIGS. 1, 3A and 4 , being, a fixed connector 4 attached to the handrail 2 and a mobile connector 6 attached to the gate arm 3 . Each connector 4 , 6 has a clevis 41 , 61 (respectively) and a stub 42 , 62 (respectively). The fixed connector clevis 41 includes two spaced-apart fingers, a first fixed finger 43 and a second fixed finger 44 , having opposed substantially-parallel planar surfaces, and a web, the fixed web 45 , spanning the fixed fingers 43 , 44 at their bases. Likewise, the mobile connector clevis 61 includes two spaced-apart opposed fingers, a first mobile finger 63 and a second mobile finger 64 , having opposed substantially-parallel planar surfaces, and a web, the mobile web 65 , spanning the mobile fingers 43 , 44 at their bases.
[0063] The link 5 is a generally rectangular parallelepiped (with curved upper and lower surfaces, as described below). The link 5 is interposed between the fixed fingers 43 , 44 and pivotally attached to the fixed connector clevis 41 by a pin 18 passing through aligned holes in the fixed fingers 43 , 44 and the link 5 . Likewise, the link is interposed between the mobile fingers 63 , 64 and pivotally attached to the mobile connector clevis 61 by a pin 18 ′ passing through aligned holes in the mobile fingers 63 , 64 and the link 5 . The gap between the fixed fingers 43 , 44 is substantially the same as the gap between the mobile fingers 63 , 64 .
[0064] The link 5 is sized and shaped such that, when the gate arm 3 to which the link 5 is attached is in the closed position, the link 5 substantially fills the space defined by the fingers 43 , 44 , 63 , 64 and the webs 45 , 65 , such that the upper link surface 53 and the lower link surface 54 (as shown in FIG. 2 ) substantially visually blend with the devises 41 , 61 . In the embodiment shown in the drawings the handrail 2 and the gate arm 3 are made of cylindrical tubing; and the devises 41 , 61 have curved outer surfaces that closely match the external profile of the handrail 2 and the gate arm 3 , and the upper link surface 53 and lower link surface 54 are similarly curved.
[0065] The link 5 and webs 45 , 65 are configured to limit the range of pivotal movement of the hinge 1 to roughly 180°, being between the closed position in which the gate arm 3 and adjoining handrails 2 are aligned and substantially coaxial as shown in FIG. 1 , and the fully open position in which the gate arm 3 is positioned alongside and substantially parallel to the handrail 2 as shown in FIG. 3A . In the closed position, as shown in FIG. 2 , a first portion of each web 45 , 65 abuts the ends of the link 5 so as to impede downward pivoting of any of the connectors 4 , 6 or link 5 relative to each other. In the open position, a second portion of each web 45 , 65 abuts the upper link surface 53 so as to impede pivoting movement of the hinge 1 beyond roughly 180° from the closed position. In this way, each connector 4 , 6 is limited to roughly 90° of pivoting movement relative to the link 5 . As shown in FIGS. 1 and 3 A, the fingers 43 , 44 , 63 , 64 have bevelled or partially curved ends so as to permit the connectors 4 , 6 to pivot past each other during the opening and closing of the gate arm 3 .
[0066] The stubs 42 , 62 are for attaching the relevant connectors 4 , 6 to the associated handrail 2 and gate arm 3 . In the embodiment shown in the drawings, the handrail 2 and gate arm 3 are made of cylindrical tubing. The stubs 42 , 62 are configured for insertion into the handrail 2 and gate arm 3 . The stubs 42 , 62 each comprise a hollow cylindrical body with an external diameter substantially the same as, or slightly less than, the internal diameter of the handrail 2 and gate arm 3 . In the embodiment shown in the drawings, each stub 42 , 62 has four longitudinally extending slits 11 and two retainer wedges 12 . The slits 11 permit the stubs 42 , 62 to be slightly compressed for insertion into the handrail 2 and gate arm 3 . The retainer wedges 12 have a relatively-long gently-inclined top surface that permits easy insertion of the stubs 42 , 62 , and a short end surface that forms a sharp corner with the gently-inclined surface, which sharp corner engages the inner wall of the hand rail 2 and gate arm 3 , as the case may be, so as to resist removal of the relevant stub 42 , 62 .
[0067] Each stub 42 , 62 is also preferably additionally secured within the relevant handrail 2 or gate arm 3 by a fastener such as a headless screw 13 , as shown in FIG. 4 . The headless screw 13 is installed by drilling a hole through the handrail 2 or gate arm 3 , and the relevant stub 42 , 62 , after the stub 42 , 62 has been inserted into the handrail 2 or gate arm 3 . The hole is then tapped with the appropriate threads and the headless screw 13 is screwed into position. The headless screw 13 is preferably screwed into one of those sections of the relevant stub 42 , 62 bounded by two slits 11 that does not have a retainer wedge 12 , so that the section of the relevant stub 42 , 62 through which the headless screw 13 is screwed is not held away from the inner wall of the handrail 2 or gate arm 3 by a retainer wedge 12 . Generally, it is preferable for aesthetic reasons that the headless screws 13 be located on the underside of the handrail 2 and the underside of the gate arm 3 , when the gate arm 3 is in the closed position, so that the headless screws 13 are not normally visible. The fastener need not be a headless screw 13 and may be a regular machine screw with a head, a rivet or a variety of other fasteners. Alternatively, the stub may be secured within the tubing by welding, such as by spot welding at a hole drilled in the tubing.
[0068] It will be clear that the connectors 4 , 6 could be attached to the handrail 2 and gate 3 by means other than insertable stubs 42 , 62 , such as by welding.
[0069] As shown in FIGS. 5 through 13 B, the lock 9 includes a passive lock component 7 and an active lock component 8 . The passive lock component 7 has a socket 70 . The active lock component 8 has a plug 72 for matingly engaging the socket 70 , and a radially-projecting depressable latching button 74 that engages a button hole 76 in the passive lock component 7 for securing the plug 72 within the socket 70 so as to secure the lock components 7 , 8 one to the other. The button 74 and socket 70 should of course have mating cross-sectional configurations and dimensions, but these need not be circular. The preferred circular cross-section of each is illustrated.
[0070] Each lock component 7 , 8 includes a stub, the passive lock component stub 78 and the active lock component stub 80 as the case may be, that is in all relevant details substantially identical to the connector stubs 42 , 62 previously described, and that may be installed in the same manner as the connector stubs 42 , 62 .
[0071] The embodiment of the lock 9 shown in the drawings is for use with handrails 2 and gate arms 3 made of round tubing; and the portions of the lock components 7 , 8 that are visible when installed and when the gate arm 3 is in the closed position, have surfaces that closely match the external profile of the handrail 2 and gate arm 3 .
[0072] In the embodiment shown in the drawings, the socket 70 is defined by an inner end wall 82 , an outer end wall 84 , a curved side wall 86 , a straight side wall 88 and a guide side wall 90 . The inner end wall 82 is substantially perpendicular to the longitudinal axis of the passive lock component 7 . The outer end wall 84 has a lower wall lip 92 that is substantially perpendicular to the longitudinal axis of the passive lock component 7 , and an upper wall lip 94 that is inclined relative to the lower wall lip 92 . The curved side wall 86 contains the button hole 76 . The curved side wall 86 adjoins the straight side wall 88 .
[0073] The plug 72 has an end face 96 , an end guide face 98 , an inner face 100 , a curved side face 102 , a straight side face 104 and an inclined side face 106 . The end face 96 is substantially perpendicular to the longitudinal axis of the active lock component 8 . The end guide face 98 adjoins, and is inclined relative to, the end face 96 . The inner face 100 has a lower face lip 108 that is substantially perpendicular to the longitudinal axis of the active lock component 8 , and an upper face lip 110 that is inclined relative to the lower face lip 108 . The button 74 projects from the curved side face 102 . The curved side face 102 adjoins the straight side face 104 .
[0074] As shown in FIG. 9 , the button 74 has a button shoulder 112 contained within the button sleeve 114 . The button sleeve 114 is secured within a cavity in the active lock component 8 and is preferably a metal sleeve pressed in a tight fit into a bore in the active lock component 8 . A spring 116 within the button sleeve 114 biases the button shoulder 112 against an annular retainer 118 at the outward end of the button sleeve 114 , such that the button 74 is spring-biassed to project from the curved side face 102 . The spring 116 is selected so that the button 74 may be manually depressed.
[0075] FIGS. 10A through 13B show some of the possible positions of the passive lock component 7 and active lock component 8 relative to each other during closing of the gate arm 3 . FIGS. 10A and 11A show the initial contact between the passive lock component 7 and the active lock component 8 in situations where there is a slight longitudinal misalignment of the lock components 7 , 8 , such as perhaps might be due to the gate arm 3 being the incorrect length, for example, too long in FIG. 10A and too short in FIG. 11A . In FIG. 10A , the point of first contact is between the top of the inner end wall 82 and the end guide face 98 , and as the active lock component 8 moves towards engagement with the passive lock component 7 , the incline of the end guide face 98 helps to guide the plug 72 into the correct longitudinal position to engage the socket 70 . Alternatively, as shown in FIG. 11A , the point of first contact may be between the bottom of the lower face lip 108 and the upper wall lip 94 , and as the active lock component 8 moves towards engagement with the passive lock component 7 , the incline of the upper wall lip 94 helps to guide the plug 72 into the correct longitudinal position to engage the socket 70 .
[0076] As shown in FIG. 11B , the contact of the button 74 with the top of the curved side wall 86 tends to cause the active lock component 8 to move laterally relative to the active lock component 7 , such that further downward movement of the active lock component 8 causes the bottom of the curved side face 102 to contact the guide side wall 90 . The incline of the guide side wall 90 combined with a downward force on the active lock component 7 causes the active lock component to move both downward and laterally so as to: depress the button 74 so as to compress the spring 116 by pushing the button 74 against the curved side wall 86 ; and bring the straight side face 104 into alignment with the straight side wall 88 , as shown in FIG. 12B . As shown in FIG. 13B , further downward movement of the active lock component 8 brings the button hole 76 into alignment with the button 74 permitting the spring 116 to expand so as to cause the button 74 to project through the button hole 76 , thus securing the active lock component 8 to the passive lock component 7 in the closed position.
[0077] In the closed position, the presence of the button 74 within the button hole 76 impedes upward movement of the active lock component 8 ; the abutting of the straight side face 104 with the straight side wall 88 and the abutting of the top of the curved side face 102 with the top of the curved side wall 86 impede lateral movement of the active lock component 8 ; and the abutting of the lower wall lip 92 with the lower face lip 108 resists longitudinal forces tending to separate the passive and active lock components 7 , 8 .
[0078] The active lock component 8 may be released from the passive lock component 7 by depressing the button 74 and moving the active lock component 8 upwards.
[0079] The button 74 may be relatively small and unobtrusive, and therefore the lock 9 is particularly aesthetically appropriate for relatively small tubing, such as 2.5 cm (1″) diameter. Further, in this embodiment, the gate arm 3 , hinge 1 and lock 9 are configured to tie the handrail 2 portion on one side of the gate opening to the handrail 2 portion on the other side of the gate opening so as to resist longitudinal tensional forces tending to spread the handrails 2 on each side of the gate opening. This tying of the handrails 2 contributes to the overall strength of the handrail 2 installation and tends to cause the gate arm 3 to stay closed even if neighbouring portions of the handrail 2 are bent, such as by heavy objects or persons falling against them, or, in the case of marine applications, due to wave impact in extreme storm conditions.
[0080] It will be clear that the lock 9 need not be associated with a hinge permitting the gate arm 3 to pivot through a full 180° and that various other hinges may be used with the lock 9 . Further, the gate arm 3 may be designed to telescope into the handrail 2 as long as there is sufficient play at the end of the gate arm 3 to permit the mating portions of the lock components 7 , 8 to clear each other as the gate arm 3 is telescoped in or out. As well, the gate arm 3 may be designed to be removable, by having a lock 9 at each end, or a lock 9 at one end and some other means for releasably engaging the handrail 2 at the other end.
[0081] The scope of the invention is not to be limited by the specific details described, but is to be given the full scope established by the appended claims. As used in the appended claims, the word “tubing” means a hollow bar of any suitable profile (e.g., round, rectangular, oval). | A gate having a gate arm, lock and hinge, for use with a handrail is disclosed. The gate in closed position retains the structural integrity and peripheral profile of the handrail. The hinge consist of two connectors, both pivotally connected to a link by pins. The connectors pivot about the pins, enabling the gate arm to pivot through 180°. The lock includes two mating components, one component having a plug and the other having a socket for receiving the plug. A depressable button secures the plug within the socket. For use with handrails made from tubing, the hinge and lock components includes stubs insertable into the tubing. All components in the closed position of the gate compactly fit together and are shaped to provide peripheral continuity. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to epoxy resin compositions which may be used to manufacture cured products which exhibit low dissipation factor and high heat resistance, and relates to cured products made therewith.
Priority is claimed on Japanese Patent Application No. 2002-317672, filed Oct. 31, 2002, the content of which is incorporated herein by reference.
2. Description of Related Art
Epoxy resins are widely used in the fields of electrical components and electronic components exemplified by semiconductor encapsulants, varnishes for printed circuit boards, and resist materials, since epoxy resins have excellent properties in electrical insulation, mechanical properties, and adhesive properties. In fields such as electrical components and electronic components, phenol resins such as phenol-novolak resins and amines such as dicyandiamide, and acid anhydrides curing agent are widely used as curing agents of epoxy resins.
However, high frequency bands are suitable to carry much information being tele-communicated recently in electrical components and electronic components exemplified printed circuit boards, and other electric insulation resist materials. For this reason, it is desired to present epoxy resin systems with a low dissipation factor to decrease the transmission loss in high frequency bands. However, when phenol resins, amine type curing agents, and anhydride curing agents are used, which are widely used as curing agents for epoxy resins, it was difficult to decrease the transmission loss since highly polar hydroxyl groups are formed in the curing reaction with epoxy resins.
Consequently, a curing agent which does not form hydroxyl groups during a curing reaction, for example, an aromatic polyester as the esterification reaction product of an aromatic dicarboxylic acid and an aromatic dihydroxy compound, is known from Japanese Unexamined Patent Application, First Publication No. Hei 5-51517. When this type of aromatic polyester is used as a curing agent, it is possible to minimize the formation of hydroxyl groups during the curing reaction as well as maximize the crosslinking density of the epoxy resin cured articles since this curing agent acts as a polyfunctional curing agent which has many ester groups per molecule and accordingly, the glass transition temperature is high and the material is useful as electrical insulating materials for electrical components and electronic components.
However, hydroxyl groups or carboxyl groups remain in cured articles because the aromatic polyesters at terminals of molecular chains are polar groups which are hydroxyl groups or carboxyl groups. When the hydroxyl groups remain, the hydroxyl groups markedly increase the dissipation factor. When the carboxyl groups remain, the carboxyl groups react with unreacted epoxy groups, and then hydroxyl groups are also formed. The existence of these hydroxyl groups caused a problem of increasing the dissipation factor.
As another technique for applying the ester resin which forms neither hydroxyl groups nor carboxyl groups at the terminals of curing agents for epoxy resin, a technique to lower the dissipation factor of the cured articles using an aromatic ester composition obtained by the reaction of naphthalenedicarboxylic acid and α-naphthol as curing agents for epoxy resin is known as claimed in claim 6 and disclosed in synthesis example 5 of Japanese Unexamined Patent Application, First Publication No. 2002-12650.
However, although the dissipation factor of the aromatic ester compounds is reduced, those ester compounds have only a few ester groups per molecule and thereby, the volume fraction of the inert terminal groups is increased. Since these terminal groups do not form crosslinking in the curing reaction, the concentrated terminal groups bring about decreased crosslinkng density in the cured articles that are inferior in heat resistance.
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide an epoxy resin system which has low dissipation factor and efficient heat resistance so as to be suitable for insulating materials for electrical components and electronic components.
To achieve the above object, the present inventors have intensively researched and found that when an aromatic hydrocarbon is an aromatic polyester bonded via an ester bond and aryloxycarbonyl groups are introduced into the aromatic hydrocarbon of the aromatic polyester at the terminal, the heat resistance of epoxy resin cured articles is improved and the dissipation factor is significantly reduced. Thus, the present invention has been completed.
The present invention relates to an epoxy resin composition comprising essential components of an epoxy resin and a curing agent which is an aromatic polyester having a structure in which an aromatic hydrocarbon group (a1) having a bonding site in an aromatic nucleus and another aromatic hydrocarbon group (a2) having a bonding site in an aromatic nucleus are bonded via an ester bond (b), and also has a structure in which an aryloxycarbonyl group (c) is the terminal of said polyester.
Epoxy resins used in the present application include novolak type epoxy resins which are glycidyl-etherified from novolak resins such as cresol novolak, phenol novolak, α-naphthol novolak, β-naphthol novolak, bisphenol A novolak, biphenyl novolak, liquid bisphenol type epoxy resins in glycidyl-etherified from bisphenol such as bisphenol A, bisphenol F, bisphenol S, tetrabromobisphenol A, 1,1-bis(4-hydroxyphenyl)-1-phenylethane and solid bisphenol A type epoxy resins which molecular weight is increased by reaction with liquid bisphenol A type epoxy resins and the above bisphenols, hydrogenated nucleus of liquid or solid bisphenol A type epoxy resins, biphenol, biphenyl type epoxy resins glycidyl-etherified from biphenol such as tetramethylbiphenol, polyglycidyl ether of phenol resin in which phenols such as polyglycidyl ethers which are addition polymers of dicyclopentadien and phenol, are linked by condensed polyalicyclic hydrocarbons, epoxy resin including condensed polycyclic aromatic groups such as diglycidyl ethers of naphthalenediol, diglycidyl ethers of binaphthol and diglycidyl ethers of bis(hydroxy naphthyl) methane, glycidyl esters of hexahydrophthalic anhydride, glycidyl esters of dimer acid, glycidyl amine of diaminodiphenylmethane, benzopyran type epoxy resins which are bonded to glycidyl oxy groups with a benzopyran composition such as dibenzopyran, hexamethyl benzopyran and 7-phenylhexamethyl benzopyran.
As a resin as an example of a novolak epoxy resin generally used in a semiconductor encapsulant in the above epoxy resins, excellent heat resistance and low dissipation factor can be exhibited in the cured articles by this invention.
Polyglycidyl ethers of phenol resins having a structure in which phenols are bonded to other phenols via a condensed polyalicyclic hydrocarbon exhibit heat resistance, outstanding mechanical strength, sufficient toughness, and in addition solder cracking resistance is excellent and a high degree of filling is possible for semiconductor encapsulants because of low melt viscosity. The condensed polyalicyclic hydrocarbon has heat resistance and low dissipation factor and in addition has excellent moisture resistance and solder cracking resistance in semiconductor encapsulant and printed circuit board materials. Benzopyran type epoxy resins exhibit excellent properties of heat resistance, dielectric properties, and flame resistance.
In these materials, benzopyran type epoxy resins and polyglycidyl ether of phenol resin in which phenols are linked by condensed polyalicyclic hydrocarbons, are preferable since they can be used for preventing the warping after molding in the application of a single sided encapsulation type package such as a ball grid alley type semiconductor because of excellent heat resistance due to high glass transition temperature of cured articles and these are used in printed-wiring assemblies because of the excellent dimensional stability of multilayer boards. In particular, a polyglycidyl ether of a phenol resin in which phenols are linked by condensed polyalicyclic hydrocarbons, is remarkably preferable in view of excellent moisture resistance as mentioned above and solder cracking resistance at the same time.
In the present application, an aromatic polyester, which is a curing agent of the epoxy resin, has a structure in which an aromatic hydrocarbon group (a1) having a bonding site in an aromatic nucleus and another aromatic hydrocarbon group (a2) having a bonding site in an aromatic nucleus are bonded via an ester bond (b), and also has a structure wherein an aryloxycarbonyl group (c) bonded at a molecule terminal thereof. Here, the ester bonding of the aromatic polyester is suitable for use in a curing agent of an epoxy resin since this bonding has a high lability to an epoxy group. Furthermore, the ester bonding of aromatic polyesters does not form highly polar hydroxyl groups when the curing reaction and the epoxy resin cured articless as reaction products exhibit indicate low dissipation factor. Moreover, since the terminal of the molecule is aryloxycarbonyl (c), although the ester bonding at the crosslink point of epoxy resin cured articles which is obtained by the reaction is hydrolyzed by moisture absorption, ester bonds do not release low molecular weight carboxylic acid molecules which would increase the dissipation factor and the obtained epoxy resin cured articles exhibit low dissipation factor under high moisture conditions.
Here, the aromatic hydrocarbon group (a1) and the aromatic hydrocarbon group (a2) is a polyfunctional group which dehydrogenated plural hydrogen atoms from an aromatic hydrocarbon nucleus including an aromatic nucleus such as a benzene ring and a naphthalene ring. Meanwhile, the structure may include ether bonds, methylene groups, ethylidene groups, and 2,2-propylene, and the structure may have halogen atoms such as chlorine atoms and bromine atoms, and methylene groups on the aromatic nucleus. Specific examples are phenylene groups (i) such as o-phenylene, m-phenylene and p-phenylene, biphenylene groups (ii) such as 4,4′-biphenylene and 3,3′-dimethyl-4,4′-biphenylene, 2,2-propane-diphenyl group, aromatic hydrocarbon group including aralkyl group (iii) represented by the following structural formulas,
polyvalent hydrocarbon groups (iv) having a structure in which benzene rings are bonded to other benzene rings via condensed polyalicyclic hydrocarbon represented by the following structural formulas,
(k in the above structural formula iv-1 is an integer, 1 in the structural formula iv-2 is an integer and these numbers are 0 to 1.5 on average; the condensed polyalicyclic hydrocarbon groups in the structural formulas iv-1′ and iv-2′ are formed by addition of aromatic nucleus to raw material of unsaturated compound), naphthalene groups such as 1,6-naphthalene, 2.7-naphthalene, 1,4-naphthalene, 1,5-naphthalene, 2,3-naphthalene, and bivalent hydrocarbon groups (v) having a naphthalene skeleton represented by the structural formulas shown below,
and bivalent aromatic hydrocarbon groups (vi) having a structure of dibenzopyran represented by the following General Formula 1,
(in the General Formula 1, wherein Y represents an oxygen atom, methylene group, methylene group substituted with alkyl groups, phenyl groups, biphenyl groups or naphthyl group, and the biphenyl groups or naphthyl groups are further substituted at the aromatic nucleus with alkyl groups; each of n and m is an integer from 1 to 3.)
Specific examples represented by the General Formula 1 may include the structural formulas shown below.
Particularly in the aromatic hydrocarbon group detailed above, polyvalent hydrocarbon groups (iv) having a structure in which benzene rings are bonded to other benzene rings via a condensed polyalicyclic hydrocarbon, bivalent hydrocarbon groups (v) having a naphthalene skeleton, and bivalent aromatic hydrocarbon groups (vi) having a structure of dibenzopyran are preferable since these have excellent dissipation factor. Specifically, the dissipation factor at 1 GHz is less than 5.0×10 −3 and this composition is suitable for electrical components and electronic components using high frequencies which are highly required today. The rate of change of dissipation factor by moisture absorption after a pressure cooker test for 2 hours at 121° C. was evaluated, and this composition shows a stable low dissipation factor even when the humidity conditions changed.
Specifically, hydrocarbon groups (iv) having a structure in which benzene rings are bonded to other benzene rings via a condensed polyalicyclic hydrocarbon, is preferable in view of heat resistance, dielectric properties, and in addition, excellent moisture resistance, and it is suitable for semiconductor encapsulant and printed-wiring assembly. In particular, compounds represented by formula iv-1, chosen from iv-1 and iv-2, are preferable since these characteristics are well balanced.
Bivalent hydrocarbon groups (v) having a naphthalene skeleton are excellent in heat resistance, toughness, and mechanical properties when used to form a cured article. Specifically, binaphthylene represented by the structural formula v-3 is preferable since these characteristics are dominant.
Moreover, the bivalent aromatic hydrocarbon groups (vi) having a structure of dibenzopyran are suitable for the application of the printed-wiring assembly since these compounds exhibit excellent flame resistance.
The hydrocarbon group (iv) in these groups is preferable since it has significant performance in which the dielectric properties are low under a humid atmosphere.
Furthermore, the aromatic hydrocarbon groups (a1) and the aromatic hydrocarbon groups (a2) may be the same or may be different. It is preferable that the aromatic hydrocarbon group (a1) be selected from the hydrocarbon groups (iv), the hydrocarbon groups (v), and the aromatic hydrocarbon groups (vi), and the aromatic hydrocarbon group (a1) be a phenylene group in view of ease of production of aromatic polyester and excellent solubility in organic solvents.
Next, the molecule terminal of an aromatic polyester comprising aryloxy carbonyl group (c) may include halogen atoms such as chlorine atoms and bromine atoms, and methyl groups, 2-propyl groups, and phenoxy groups as substituents on benzene rings and naphthalene rings in the structure. Specifically, the following structure is preferable in view of heat resistance and dielectric properties.
The structure including a naphthalene skeleton represented by the formula c-11 and formula c-12 in the above structure, and biphenyloxycarbonyls represented by formula c-6 and c-7 are preferable since these exhibit notably low dielectric properties. The number of aryloxycarbonyl (c) groups in the aromatic polyester is reduced since the aromatic polyester is a high molecular weight compound per se. Since the terminal aryl moiety of aryloxycarbonyl(c) groups do not form the intermolecular crosslink networks in the curing reaction with epoxy resin, a reduced concentration of aryloxycarbonyl (c) groups result in a high crosslinking density, thereby, an elevated glass transition temperature.
The following structure is exemplified in the case in which phenylene groups (i) in these aromatic polyesters, bonded via ester bond (b) with hydrocarbon groups (iv) having a structure in which other benzene rings, are bonded via a condensed polyalicyclic hydrocarbon.
(wherein Ph represents phenyl, biphenyl, or naphthyl and o is an integer which is 0.4 to 20 on average and condensed polyalicyclic hydrocarbon in the formula is formed by addition of aromatic nucleus to raw material of an unsaturated compound.)
Furthermore, an aromatic polyester which has a bonded phenylene group (i) with bivalent hydrocarbon groups (v) having a naphthalene skeleton via ester bonding (b) is exemplified in the following structure.
(wherein Ph represents phenyl, biphenyl, or naphthyl and p is an integer which is 0.4 to 20 on average.)
Moreover, the aromatic polyester which bonded phenylene group (i) with bivalent aromatic hydrocarbon groups (vi) having a structure of dibenzopyran represented by the formula vi-5 is exemplified in the following structure.
(wherein Ph represents phenyl, biphenyl, or naphthyl, and q is an integer which is 0.4 to 20 on average.)
It is preferable that the inherent viscosity of the aromatic polyester detailed above be within a range of 0.02 to 0.42 dL/g since it has good heat resistance due to high crosslink density in cured articles as mentioned above. Moreover, in a case in this range of inherent viscosity, the solubility in toluene and methyl ethyl ketone (MEK) which is used in adjustment of varnish for printed circuit boards is good and in addition, this good solubility can prevent precipitation of crystals. Furthermore, in the case within this range of the inherent viscosity when applied to a semiconductor encapsulant, it becomes possible to obtain a high degree of filling of the filler because of good fluidity when melted.
Specifically, the solubility in methyl ethyl ketone (MEK) and toluene is better in the case in which the inherent viscosity of the aromatic polyester is within a range of 0.03 to 0.15 dL/g. Moreover, the aromatic polyester having the inherent viscosity within this range can be dissolved up to 50 wt % in methyl ethyl ketone (MEK) and toluene. This 50 wt % solution is homogeneous, transparent, and stable at room temperature. This aromatic polyester exhibits excellent solubility, without any participation of solid, after repeated the thermal cycle test, which cycle the steps in which a 50 wt % solution is left for 5 hours at 25° C. and is then left for 11 hours at −20° C. The polyester has an advantage of thermal processing since it melts and softens at 200° C. or less without any solvent. The aromatic polyester is formed by polycondensation of esterification reaction polyhydric phenol (a′-1) bonded to the aromatic hydrocarbon groups (a1) or the aromatic hydrocarbon groups (a2) with hydroxyl group, and polyvalent carboxylic acid (a′-2) bonded to the aromatic hydrocarbon groups (a1) or the aromatic hydrocarbon groups (a2) with carboxyl groups. Then, the aromatic polyester is produced by esterification of the terminal carboxyl groups of the above polycondensed intermediate and monohydric phenol (c′) bonded aryl groups which is the aryloxycarbonyl groups (c) with hydroxyl groups.
The aromatic polyester may be produced by ester exchange reaction and Schotten-Baumann reaction. An example of an ester exchange reaction is one in which the aromatic polyester is obtained by the step of acetylation of polyhydric phenol and monohydric phenol (c′) by acetic anhydride and the step of acidolysis of the acetylation result and the polyvalent carboxylic acid (a′-2). Since the reactivity is low in these esterification reactions in general, ester exchange reaction and Schotten-Baumann reaction are preferable.
When the Schotten-Baumann reaction is used, there may be mentioned an interfacial polycondensation method which is implemented at a boundary face and asolution polycondensation method which reaction is implemented in a homogeneous solution. In the interfacial polycondensation method, an aromatic polyester is obtained by the contact of an organic liquid phase including acyl halide of polyvalent carboxylic acid (a′-2) and an aqueous phase including monohydric phenol (c′), and then interfacial polycondensation in the presence of an acid acceptor. In the solution polycondensation method, aromatic polyester is obtained by hydrohalogenation reaction mixing of a solution including acid halide of polyvalent carboxylic acid (a′-2) and a solution including polyhydric phenol (a′-1) and monohydric phenol (c′) in the presence of an acid acceptor.
A method for producing aromatic polyester used in the present invention applying the Schotten-Baumann reaction as an example is described specifically below. Any compounds which have a bond with the above aromatic hydrocarbon groups represented by the formulas (i) to (vi) with the hydroxyl group may be used as polyhydric phenol (a′-1) used in the manufacture of aromatic polyester and the compound bonded hydroxyl group with the compound which is bonded with the hydroxyl group with polyvalent hydrocarbon groups (iv) having a structure in which the benzene rings are bonded to other benzene rings via a condensed polyalicyclic hydrocarbon is preferable since moisture resistance is excellent and dissipation factor can be further reduced. An example of these compounds is shown in the following structural formula.
k in the formula iv-1′ and 1 in the formula iv-2 are integers which are 0 to 1.5 on average. The condensed polyalicyclic hydrocarbon groups in the structural formulas iv-1′ and iv-2′ are formed by addition of aromatic nucleus to the raw material of an unsaturated compound. A specific example is dicyclopentadiene type phenol resin represented by the formula iv-1′ in these formulas since this resin is excellent in moisture resistance and exhibits stable dielectric properties under high moisture conditions. Specifically, the average of k and l is within a range of 0 to 0.2 in view of antigelling characteristics.
Polyhydric phenols having a structure in which bivalent hydrocarbon groups (v) having a naphthalene skeleton bonded to a hydroxyl group are preferable since these are excellent in heat resistance and yield cured articles in which the dissipation factor is low. Examples of these polyhydric phenols are dihydroxynaphthalenes such as 1,6-dihydroxynaphthalene groups, 2-7-dihydroxynaphthalene groups, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, and the following structures.
Moreover, polyhydric phenol bonded hydroxyl groups with bivalent aromatic hydrocarbon groups (vi) having a structure of the dibenzopyran is preferable since the effect of reducing the dissipation factor is remarkable. These polyhydric phenols are exemplified by the following General Formula 2.
(wherein Y represents an oxygen atom, methylene group, methylene group substituted with alkyl groups, phenyl groups, biphenyl groups or naphthyl group, and the biphenyl groups or naphthyl groups are further substituted at the aromatic nucleus with alkyl groups; each of n and m is an integer from 1 to 3.) These structures represented by General Formula 2 are exemplified by the following structures.
Any compounds which have bonds as in the above aromatic hydrocarbon represented by the formulas (i) to (vi) with a carboxyl group may be used as a polyvalent carboxylic acid (a′-2) reacted with a polyhydric phenol (a′-1)
Examples of polyvalent hydrocarbon compounds bonded phenylene groups (i) with carboxyl groups are isophthalic acid, terephthalic acid, trimesic acid, trimellitic acid, and pyromellitic acid. An example of polyvalent hydrocarbon groups bonded biphenylene groups (ii) with carboxyl groups is biphenylenedicarboxylic acid. Examples of polyvalent hydrocarbon compounds bonded aromatic hydrocarbon group including aralkyl group (iii) with carboxyl groups are compounds represented by the following General Formula 3 and compounds having a structure which includes a nucleus substituted with methyl groups, ethyl groups, or halogen atoms.
(wherein X represents —CH 2 — and —C(CH 3 ) 2 —.)
Examples of polyvalent hydrocarbon compounds with carboxyl groups bonded to polyvalent hydrocarbon groups (iv) having a structure in which benzene rings are bonded to other benzene rings via a condensed polyalicyclic hydrocarbon are compounds in which a repeating unit in structural formula iv-1 is bonded to carboxyl groups and compounds in which structural formula iv-1 is bonded to carboxyl groups. Examples of polyvalent hydrocarbon compounds bonded carboxyl groups with bivalent hydrocarbon groups (v) having a naphthalene skeleton are 1,4-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid and 2,6-naphthalenedicarboxylic acid. An example of polyvalent hydrocarbon compounds bonded carboxyl groups with bivalent aromatic hydrocarbon groups (vi) having a structure of dibenzopyran is a compound represented by the following General Formula 4.
(wherein Y represents an oxygen atom, methylene group, methylene group substituted with alkyl groups, phenyl groups, biphenyl groups or naphthyl group, the biphenyl groups or naphthyl groups being optionally further substituted at the aromatic nucleus with alkyl groups; each of n and m is an integer from 1 to 3.)
Specifically, compounds having a structure of carboxyl groups at the bonding site of the structures are represented by the above vi-1 to vi-9. Since the solubility of aromatic polyester in organic solvents such as methyl ethyl ketone (MEK) and toluene is good for keeping the dissipation factor low, and the cured articles exhibit high glass transition temperature and low dissipation factor, polyvalent hydrocarbon compounds bonded carboxyl groups with mononuclear aromatic hydrocarbon groups and polyvalent hydrocarbon compounds bonded carboxyl groups with biphenylene groups (ii), specifically biphenylenedicarboxylic acid, are preferable in these structures. Aromatic polyester obtained from isophthalic acid or a mixture of isophthalic acid and terephthalic acid is excellent in solubility to various solvents. Specifically, it is preferable to use only isophthalic acid when the inherent viscosity is less than approximately 0.2 dL/g and to use a mixture of isophthalic acid and terephthalic acid when inherent viscosity is 0.2 dL/g or more.
The carboxylic acid (a′-2) is used as acyl halide when aromatic polyester is manufactured by Schotten-Baumann reaction. The halogen atoms of acyl halide in this case, chlorine atoms, and bromine atoms are preferable.
In the structure of monohydric phenol (c′), a substituent on the benzene ring and naphthalene ring may be halogen atoms such as chlorine atoms and bromine atoms, methyl groups 2-propyl groups and phenoxy groups, and specifically, the following structure is preferable in view of heat resistance and dielectric properties.
Structures including a naphthalene skeleton represented by formula c′-11 and formula c′-12 and structures including a biphenyl skeleton represented by formulas c′-6 and c′-7 are preferable in the above structures since they can exhibit especially low dissipation factor. In these structures, c′-12 is preferable since polyesters derived therefrom show ontstanding solubility in organic solvents.
As solvents for the organic solution phase in a production process of aromatic polyester by interfacial polycondensation method, solvents which dissolve acyl halide of carboxylic acid (a′-2), which are chemically stable against acyl halide, and which are not compatible with water, are preferable; for example, toluene and dichloromethane are preferable. Polyhydric phenol (a′-1) and an alkaline substance which is an acid acceptor are dissolved in an aqueous phase.
As solvents for the production process by solution polycondensation method, solvents which dissolve acyl halide of carboxylic acid (a′-2), polyhydric phenol (a′-1) and monohydric phenol (c′) and which is chemically stable against acyl halide and, for example, toluene and dichloromethane, are preferable. Examples of the acid acceptor used for a polycondensation reaction are pyridine and triethylamine.
The ratio of reaction of each of the above raw material components differs according to desired inherent viscosity, and when producing an aromatic polyester having an inherent viscosity of 0.02 to 0.42 dL/g, it is preferable that the equivalence ratio of polyhydric phenol (a′-1), carboxylic acid (a′-2) and the monohydric phenol (c′) be within a range of
polyhydric phenol ( a ′-1)/carboxylic acid ( a ′-2)=0.28 to 0.95
and
polyhydric phenol ( a ′-1)/monohydric phenol ( c ′)=0.20 to 10.
To reduce the content of impurities in the obtained aromatic polyester, purification by washing and reprecipitation is preferable. When the impurities such as monomers, halogen ions, alkali metal ions, alkali earth metal ions and salts remain in the aromatic polyester, these impurities affect adversely affect the dissipation factor and other electrical properties.
Epoxy resin compositions of the present invention may use the epoxy resins, the aromatic polyesters and hardening accelerators. Examples of the hardening accelerator are imidazole compounds such as 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 2-heptadecylimidazole, 2-undecylimidazole, organic phosphine compounds such as triphenylphosphine, tributylphosphine, organic phosphite compounds such as trimethyl phosphite, triethyl phosphite, phosphonium salts such as ethyltriphenyl phosphonium bromide, tetraphenyphosphonium tetraphenylborate, trialkylamine such as triethylamine, tributylamine, amine compounds such as 4-(dimethylamino) pyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), salt with DBU and terephthalic acid and salt with 2,6-naphthalenedicarboxylic acid, quaternary ammonium such as tetraethylammonium chloride, tetrapropylammonium chloride, tetrabutylammonium chloride, tetrabutylammonium bromide, tetrahexylammonium bromide, benzyltrimethylammonium chloride, urea compounds such as 3-phenyl-1,1-dimethylurea, 3-(4-methylphenyl)-1,1-dimethylurea, chlorophenylurea, 3-(4-chlorophenyl)-1,1-dimethylurea, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, alkaline agents such as sodium hydroxide, potassium hydroxide, and salts of crown ether such as potassium phenoxide and potassium acetate. Specifically, imidazole compounds and 4-(dimethylamino) pyridine are preferable among these compounds.
As the mixing ratio of an epoxy resins and an aromatic polyester in the epoxy resin composition of the present invention, a mixing ratio of 0.15 to 5 moles of ester groups in the aromatic polyesters per 1 mole of epoxy groups in the epoxy resins is preferable, and 0.5 to 2.5 moles of ester groups in the aromatic polyesters per 1 mole of the epoxy groups in the epoxy resins is more preferable. When the mixing ratio of aromatic polyester is outside the above range, the reaction of epoxy resin and aromatic polyester does not proceed sufficiently, and the effect on dissipation factor and glass transition temperature are insufficient.
The mixing ratio of hardening accelerator is preferably within a range of 0.01 to 5 parts by weight per 100 parts by weight of epoxy resin. When the mixing ratio of hardening accelerator is less than 0.01 parts by weight, the curing reaction rate is low, and when it is over 5 parts by weight, homopolymerization of the epoxy resin occurs, and this may prevent the curing reaction of an epoxy resin by an aromatic polyester.
The epoxy resin composition of the present invention may contain inorganic fillers according to intended application. Examples of the inorganic filler include fumed silica, crystalline silica, alumina, aluminum hydroxide and magnesium hydroxide. When the amount of inorganic filler is particularly large, fumed silica is preferably used. Although either of crushed fumed silica and spherical fumed silica can be used, spherical fumed silica is preferably used so as to increase the amount of fumed silica and to suppress an increase in melt viscosity of a molded material. To increase the amount of the spherical silica, size distribution of the spherical silica is preferably adjusted. The higher the filling factor, the better, in view of flame resistance. The filling factor is particularly preferably at least 65% by weight based on the total amount of the epoxy resin composition in semiconductor encapsulants. In applications such as conductive pastes, conductive fillers such as silver powder and copper powder can be used.
If necessary, various additives such as silane coupling agents, releasants, pigments, and emulsifiers can be used in the epoxy resin composition of the present invention. The epoxy resin composition of the present invention is obtained by uniformly mixing the components described above. For example, an epoxy resin composition for coating is prepared by uniformly mixing an epoxy resin, a curing agent and, if necessary, additives such as organic solvents, fillers, and pigments using a disperser such as a paint shaker.
When the epoxy resin composition of the present invention is used to make cured articles, the cured articles exhibit excellent heat resistance, low dissipation factor, and excellent dielectric properties in high frequency type electronic components in which the frequency is 1 GHz or more and which have recently been much in demand. The epoxy resin composition is suitable for printed circuit boards and semiconductor encapsulants.
A melt-mixing type epoxy resin composition suitable for use in semiconductor encapsulants is prepared by uniformly mixing a mixture of the epoxy resin, aromatic polyester, curing agent, inorganic fillers and, if necessary, other epoxy resins, using an extruder, a kneader, or a roller. In this case, silica is commonly used as the filler. The amount of the filler is preferably within a range from 30 to 95% by weight based on 100 parts by weight of the epoxy resin composition, and particularly preferably at least 70% by weight, in order to improve moisture resistance, and solder cracking resistance, and to decrease the linear expansion coefficient.
An epoxy resin composition of the materials for a printed circuit board, other multilayer boards, and carbon fiber reinforced plastics (CFRP) is prepared by dissolving the epoxy resin composition in an organic solvent to form a varnish-like composition. Examples of the organic solvents are amide system solvents such as N-methyl pyrrolidone, N-methylformamide, N,N-dimethylformamide and N,N-dimethylacetamide, acetone, ketone solvents such as methyl ethyl ketone (MEK), methyl isobutyl ketone, cyclohexanone, ethers solvents such as tetrahydrofuran (THF), 1,3-dioxolane, anisole, aromatic hydrocarbon solvents such as toluene and xylene, monoetherglycol solvents such as ethyleneglycol monomethylether and ethyleneglycol monobutylether. In the case of the solvents, the ratio of the solvents is usually selected within a range of 10 to 70 parts by weight, and preferably within a range of 15 to 65 parts by weight with 100 parts by weight based on the mixture of the epoxy resin composition of the present invention and the solvents. Furthermore, a laminate made of the epoxy resin composition is produced by impregnating a base material such as glass fibers, carbon fibers, polyester fibers, polyamide fibers, alumina fibers, and paper with an epoxy resin composition solution (varnish-like composition) and drying the impregnated base material by heating to form a prepreg, followed by hot press forming.
The present invention significantly improves heat resistance and provides epoxy resin cured articles low dissipation factor to modify the insulating material in high frequency type electrical components and electronic components.
Specifically, the epoxy resin cured articles obtained by curing the epoxy resin composition of the present invention have a glass transition temperature of 160° C. or more, a linear expansion coefficient of 60×10 −6 ° C. −1 or less, no change in quality in the immersion test in solder at 300° C., and minimized dimensional changes due to heating.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be further described in detail by way of examples and comparative examples. In the following, parts and percentages are by weight unless otherwise specified.
SYNTHESIS EXAMPLE 1
In a flask, 1000 ml of water, 20 g of sodium hydroxide, an aromatic monohydroxy compound, and an aromatic polyhydroxy compound in the amounts shown in the column of Synthesis Example 1 in Table 1 were charged in a nitrogen gas stream and the mixture was stirred by a Pfaudler impeller at 300 r.p.m. for 1 hour. The flask was held at 30° C., and a solution in which acyl halide of aromatic polyvalent hydrocarbon groups as shown in Table 1, was dissolved in 1000 ml of methylene chloride by dropping over 15 seconds and being stirred for 4 hours. The obtained mixture solution was allowed to settle and the aqueous phase was separated and removed. The remaining methylene chloride phase was washed with a 0.5% sodium hydroxide aqueous solution followed by removal of the aqueous phase was repeated 3 times. Furthermore, washing the methylene chloride phase with deionized water and removal of the aqueous phase was repeated 3 times. After the reduction of the washed methylene chloride phase in 400 ml, it was dropped into 1000 ml of heptane over 15 seconds, the precipitated phase was washed with methanol, filtrated, and dried, and polyester (A1) was obtained.
SYNTHESIS EXAMPLES 2 TO 9
Polyester (A2) to (A8) and ester compound (A9) were obtained in the same manner as Synthesis Example 1 according to the raw material compositions in Tables 2 and 3.
SYNTHESIS EXAMPLE 10
11 g of triethylamine and 5.1 g of resorcinol were dissolved in 400 ml of tetrahydrofuran in a flask in a nitrogen gas stream, and a solution in which 5.1 g of isophthaloyl chloride was dissolved in 100 ml of tetrahydrofuran was dropped over 30 minutes while cooled by ice. After stirring for 4 hours, a solution in which 19.9 g of p-acetoxybenzoic acid chloride was dissolved into 100 ml of tetrahydrofuran was dropped into the above solution. After the dropping, the result solution was poured into a 5% concentration of sodium carbonate aqueous solution and the precipitate was suction filtrated and washed with water and methanol and vacuum dried, and polyester (H1) (2900 of the number average molecular weight standardized with polyethylene) represented by the following structural formula was obtained.
SYNTHESIS EXAMPLES 11
To a flask, 600 ml of pyridine, 105 g of novolak type phenol resin “TD-2090” (hydroxyl group equivalent of 105 g/eq.) manufactured by Dainippon Ink and Chemicals, Inc., and 140.6 g of benzoyl chloride were charged and reacted at 30° C. for 3 hours in a nitrogen gas stream. Then 1500 ml of methyl isobutyl ketone was added and washed with deionized water to remove methyl isobutyl ketone, and polyester (H2) (1300 of the number average molecular weight standardized with polyethylene) which has the repeating unit represented by the following structural formula, was obtained.
SYNTHESIS EXAMPLE 12
To a flask, 1000 ml of water and 20 g of sodium hydroxide were charged, and 45.7 g of bisphenol A and 1.2 g of tetrabutylammonium bromide were dissolved. The flask was held at 30° C., and 100 ml of methylene chloride solution in which 32.5 g of isophthalic acidchloride and 8.1 g of terephthalic acidchloride were dissolved, was added thereto by dropping for 30 seconds. After stirring for 1 hour, the reaction products were allowed to settle and the aqueous phase was separated and removed. The remaining methylene chloride phase was washed with a 0.5% sodium hydroxide aqueous solution and the aqueous phase was removed and these operations were repeated 3 times. Additionally, washing with deionized water and removal of the aqueous phase were repeated 3 times. After reduction of the washed methylene chloride phase in 400 ml, 1000 ml of heptane was dropped over 15 seconds, the precipitated phase was washed with methanol, filtrated, and dried, and the polyester (H3) (8600 of the number average molecular weight standardized with polyethylene) which has the repeating unit represented by the following structural formula, was obtained.
SYNTHESIS EXAMPLE 13
Into a flask, 152 g of trimethylhydroquinone was charged and dissolved into a mixture of solvents of 500 g of toluene and 200 g of ethyleneglycol monoethylether. 4.6 g of p-toluenesulfonic acid was added to the solution and 64 g of benzaldehyde was dropped and the mixture was stirred at 120° C. for 15 hours to remove water contained therein. Then, after cooling, precipitated crystals were filtered out, and washed with water repeatedly until the filtrate was neutral, and dihydroxybenzopyran represented by the following structural formula was obtained.
SYNTHESIS EXAMPLE 14
Into a flask, 187 g of dihydroxybenzopyran obtained in Synthesis Example 13, 463 g of epichlorohydrin, 53 g of n-butanol and 2.3 g tetraethylbenzyl ammonium chloride were charged and dissolved in a nitrogen gas stream. The flask was evacuated to the azeotropic pressure of the solution at 65° C. and 82 g of 49% sodium hydroxide aqueous solution was dropped over 5 hours and stirred for 30 min. After removing unreacted epichlorohydrin by reduced pressure distillation, 15 g of 10% sodium hydroxide aqueous solution was reacted with a solution of 550 g of methyl isobutyl ketone and 55 g of n-butanol at 80° C. for 2 hours. The reaction result was washed with water, and the benzopyran type epoxy resin represented by the following structural formula was obtained.
TABLE 1
Synthesis Examples
1
2
3
4
5
Composition (weight (g))
A1
A2
A3
A4
A5
Acyl halide polyvalent
hydrocarbon groups
Isophthalic acid chloride
20.3
32.5
20.3
20.3
20.3
Terephthalic acid
20.3
8.1
20.3
20.3
20.3
chloride
Monophenol
α-naphthol
3.6
5.2
7.2
β-naphthol
5.2
o-phenylphenol
6.2
Polyphenol
DCPDDP
61.9
60.0
30.0
DHDBP
68.1
DHDN
52.0
BPFL
31.9
n (repeating unit
15
10
10
10
10
of polyester)
Inherent viscosity (dL/g)
0.312
0.202
0.224
0.213
0.210
TABLE 2
Synthesis Examples
6
7
8
9
Composition (weight (g))
A6
A7
A8
A9
Acyl halide of polyvalent
hydrocarbon groups
Isophthalic acid chloride
20.3
20.3
20.3
20.3
Terephthalic acid chloride
20.3
20.3
20.3
20.3
Monophenol
α-naphthol
7.2
5.2
5.2
61.9
β-naphthol
o-phenylphenol
Polyphenol
DCPDDP
57.8
52.8
44.0
DHDBP
DHDN
BPFL
n (repeating unit of polyester)
7
4
2
0
Inherent viscosity (dL/g)
0.15
0.09
0.053
0.013
Polyphenols shown in Table 1 and Table 2 are defined below. The values in Table 1 are given by weight (g).
Inherent viscosity values were determined, in accordance with Japanese Industrial Standard JIS K2283, with a Canon-Ubbelohde viscometer at 25° C. using 0.5 g/dL solutions in chloroform.
DCPDDP: Dicyclopentadienyl diphenol “DPP-6085” manufactured by Nippon Oil Co., Ltd. (Aromatic polyhydroxy compounds in which k is 0.16 on average in formula (11). Hydroxyl group equivalent of 165 g/eq.)
DHDBP: Dihydroxybenzopyran (which is an aromatic polyhydroxy compound represented by formula (14) obtained by Synthesis Example 9 wherein Y in formula (12) is a methylene group substituted with a phenyl group and n and m are 3. Hydroxyl group equivalent of 187 g/eq.)
DHDN: Dihydroxydinaphthalene manufactured by Tokyo Kasei Kogyo Co., Ltd., which is an aromatic polyhydroxy compound represented by formula (13). Hydroxyl group equivalent of 143 g/eq.)
BPFL: Bisphenolfluorene manufactured by Nippon Steel Chemical Co., Ltd. (aromatic polyhydroxy compound represented by formula (14). Hydroxy equivalent of 175 g/eq.)
EXAMPLES 1 TO 9
Curing agents which were polyesters A1 to A8 obtained in Synthesis Examples 1 to 8, an epoxy resin, a hardening accelerator and a solvent are mixed in compositions as shown in Tables 3 and 4 at 25° C., and a varnish was prepared. The prepared varnish was coated on an aluminum dish, heated to 120° C. to drive off the solvent and become semi-hardened (the B stage) at 170° C. on a hot plate. Then, the semi-hardened coating was peeled from the aluminum dish and made into a powder. The powder was pressed at 170° C. at 3 MPa for 1 hour and was hot cured in a vacuum oven at 190° C. at 133 Pa for 10 hours, and epoxy resin cured articles were obtained.
COMPARATIVE EXAMPLES 1 TO 6
Curing agent which is ester compound A9 obtained by Synthesis Example 9, polyesters H1 to H3 obtained by Synthesis Examples 6 to 8, adipic acid di(nitrophenyl)ester and methyltetrahydrophthalic anhydride, and an epoxy resin, a curing agent, a hardening accelerator, and a solvent are mixed in the compositions as shown in Table 5 and a varnish was prepared. The prepared varnish was coated on an aluminum dish, heated up at 120° C. to drive off solvents and become semi-hardened (the B stage) at 170° C. on a hot plate. Then, the semi-hardened coating was peeled from the aluminum dish and made into a powder. The powder was pressed at 170° C. at 3 MPa for 1 hour and hot cured in a vacuum oven at 190° C. at 133 Pa for 10 hours, and epoxy resin cured articles made therewith were examined.
The glass transition temperature (Tg), dielectric properties, linear expansion coefficient, and heat resistance to solder made from the epoxy resin cured articles obtained in Examples 1 to 9 and Comparative Examples 1 to 6 were measured by the methods described below, and the results are shown in Tables 5 and 6.
Measurement of Glass Transition Temperature (Tg)
Glass transition temperature was measured as peak temperature of tan δ at 1 Hz by a dynamic mechanical analyzer “DMS200” manufactured by Seiko Instruments, Inc.
Measurement of Dielectric Properties
By a method according to Japanese Industrial Standard JIS-C-6481, the dielectric constant at 1 GHz and the dissipation factor were measured by an impedance material analyzer “HP4291B” manufactured by Agilent Technologies. The samples were the epoxy resin cured articles which were stored in a room at 23° C. at 50% humidity after being completely dried, and the epoxy resin cured articles were tested in a moisture resistance test using a pressure cooker test for 2 hours.
Measurement of Linear Expansion Coefficient
Linear expansion coefficient of the epoxy resin cured articles when the temperature was changed from 30 to 50° C. was measured by a thermal mechanical analyzer “TMA/SS120C” manufactured by Seiko Instruments, Inc.
Test of Heat Resistance to Solder
By a method according to Japanese Industrial Standard JIS-C-6481, the condition of epoxy resin cured articles immersed in a solder bath at 300° C. for 120 seconds was inspected visually. In the Tables, “O” means no expansion or cracking was visually observed, and “x” means expansion and cracking were visually observed.
TABLE 3
Example
1
2
3
4
5
Epoxy resins
EPICLON HP-7200H
100
20
100
100
EPICLON N-695
100
Benzopyran type epoxy resin
80
Curing agents
polyester A1
49
polyester A2
50
polyester A3
54
polyester A4
45
polyester A5
66
Hardening accelerators
2E4MZ
0.5
0.5
0.5
0.5
DMAP
0.5
Solvents
1,3-dioxolane
160
180
180
200
toluene
170
Glass transition temperature (° C.)
170
178
169
182
196
dielectric constant (1 GHz)
2.85
2.86
2.97
2.98
2.92
dissipation factor (× 10 −4 , 1 GHz)
31
29
38
36
43
Dielectric constant after moisture absorption
2.86
2.87
3.02
3.01
3.06
(1 GHz)
Dissipation factor after moisture absorption
34
34
45
45
56
(× 10 −4 , 1 GHz)
linear expansion coefficient (× 10 −6 ° C. −1 )
56
52
52
51
50
Heat resistance to solder
∘
∘
∘
∘
∘
TABLE 4
Example
6
7
8
9
Epoxy resins
EPICLON HP-7200H
100
100
100
100
EPICLON N-695
Benzopyran type
epoxy resin
Curing agents
polyester A6
66
polyester A7
66
100
polyester A8
67
hardening accelerator
DMAP
0.5
0.5
0.5
0.5
Solvents
1,3-dioxolane
200
200
200
200
Glass transition temperature
182
165
162
174
(° C.)
dielectric constant
2.92
2.94
2.93
2.93
(1 GHz)
dissipation factor
38
33
28
42
(× 10 −4 , 1 GHz)
Dielectric constant after
3.07
3.08
3.08
3.08
moisture absorption (1 GHz)
Dissipation factor after
49
39
34
58
moisture absorption
(× 10 −4 , 1 GHz)
linear expansion coefficient
50
51
52
52
(× 10 −6 ° C. −1 )
Heat resistance to solder
∘
∘
∘
∘
TABLE 5
Comparative Example
1
2
3
4
5
6
Epoxy resin
EPICLON HP-7200H
100
100
100
100
100
EPICLON N-695
100
Curing agent
Polyfunctional activated ester
42
H1
Polyfunctional activated ester
93
H2
Polyfunctional activated ester
65
H3
Ester componds A9
75
di(nitrophenyl)ester adipate
70
methyltetrahydrophthalic
30
anhydride
hardening accelerator
2E4MZ
0.5
0.5
0.5
0.5
0.5
0.5
Solvent
1,3-dioxolane
500
300
400
400
400
300
Glass transition temperature (° C.)
153
182
185
129
88
171
dielectric constant (1 GHz)
3.05
3.29
2.94
2.85
3.38
3.36
dissipation factor (× 10 −4 , 1 GHz)
91
125
104
23
111
116
Dielectric constant after moisture absorption
3.10
3.43
3.08
2.88
3.55
3.61
(1 GHz)
Dissipation factor after moisture absorption
124
188
152
35
273
224
(× 10 −4 , 1 GHz)
linear expansion coefficient (× 10 −6 ° C. −1 )
57
55
56
48
88
51
Heat resistance to solder
∘
∘
∘
∘
x
∘
Epoxy resins are shown in Tables 3 to 5, and hardening accelerators are dexcribed below. The values in Tables 2 and 3 are given by weight (g).
EPICLON HP-7200H: Dicyclopentadiene novolak type epoxy resin manufactured by Dainippon Ink and Chemicals, Inc., (epoxy equivalent of 280 g/eq.)
EPICLON N-695: Cresol novolak type epoxy resin manufactured by Dainippon Ink and Chemicals, Inc., (epoxy equivalent of 225 g/eq.)
Benzopyran type epoxy resin obtained by Synthesis Example 10 and represented by Formula (25) (epoxy equivalent of 265 g/eq.)
2E4MZ: 2-ethyl-4-methylimidazole
DMAP: 4-dimethylaminopyridine
As is clear from Tables 3 to 5, epoxy resin cured articles shown in the Comparative Examples could not have a low dissipation factor of no more than 5.0×10 −3 at 1 GHz and could not have high heat resistance with a glass transition temperature of 160° C. or more at the same time. In contrast, epoxy resin cured articles compositions including polyester (A) of the present invention have a low dissipation factor of no more than 5.0×10 −3 at 1 GHz and the change in the dissipation factor by moisture absorption was small. Those cured articles made from epoxy resin compositions including polyester (A) of the present invention have high glass transition temperatures of 160° C. or more and no significant dimensional change by heat was observed. No expansion and cracking by immersion into a solder bath at 300° C. occurred. It was discovered that the epoxy resin compositions required less solvent when varnishes were prepared, and the solubility was excellent.
EXAMPLES 10 TO 16 AND COMPARATIVE EXAMPLE 7
Solubility in solvents of the polyesters A1 to A8 and the ester compound A9 were evaluated. At 25° C., 5 g of one selected from the polyesters A1 to A8 and the ester composition A9 and 20 g or 5 g of solvents, were charged into screw vials and stirred by magnetic stirrers for 12 hours. Mixtures having concentration of 20 wt % or 50 wt % were prepared. When the obtained mixture was homogeneous and transparent and the state which is homogeneous and transparent state without any precipitate was maintained after 2 weeks at 25° C., a “+” (soluble) is given as the evaluation result in Table 6. When a solid portion which did not dissolve and a phase separation were observed, a “−” is given as the evaluation result, and the results are shown in Table 6.
TABLE 6
Example
Comparative
10
11
12
13
14
15
16
17
Example 7
Polyester or ester compounds
A1
A2
A3
A4
A5
A6
A7
A8
A9
Solubility in toluene
conc. = 20 wt %
+
+
+
+
+
+
+
+
−
conc. = 50 wt %
−
−
−
−
−
+
+
+
−
Solubility in THF
conc. = 50 wt %
+
+
+
+
−
+
+
+
−
conc. = 20 wt %
+
+
+
+
+
+
+
+
+
Solubility in MEK
conc. = 20 wt %
−
−
+
+
−
+
+
+
+
conc. = 50 wt %
−
−
−
−
−
+
+
+
−
Solubility in
cyclohexanone
conc. = 20 wt %
+
+
+
+
−
+
+
+
+
conc. = 50 wt %
+
+
+
+
−
+
+
+
−
While preferred embodiments of the invention have been described and illustrated above, it should be understood that these are exemplary of the invention and are not to be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit or scope of the present invention. Accordingly, the invention is not to be considered as being limited by the foregoing description, and is only limited by the scope of the appended claims. | An epoxy resin cured article has a high glass transition temperature and low dissipation factor. An epoxy resin composition from which the cured article can be having excellent solubility in solvents is used to produce the cured articles. A polyester as a curing agent of an epoxy resin composition having an aromatic polyhydroxy coumpound residue including an aryloxycarbonyl group at the molecule of the terminal, an aromatic polyvalent hydrocarbon group residue, and bulky structure, is used. Since the curing agent behaves as a polyfunctional curing agent, a cured article produced therefrom has a high crosslink density. Since highly polar hydroxyl groups are not formed during curing, a cured article has high glass transition temperature and a low dissipation factor. The cured article does not release low molecular weight carboxylic acids though hydrolysis of ester bonds at crosslinked bonds. Since the polyester has a bulky structure, the crystallization of the molecular chain is prevented and the solubility of the epoxy resin composition containing the polyester is excellent. | 2 |
This application is a continuation, of application Ser. No. 111,870, filed Jan. 14, 1980, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to firearms. More specifically, this invention relates to handguns capable of firing high-powered ammunition.
Conventional handguns have employed a rebound assembly comprising a strut which engages the hammer after firing and returns the hammer to the at-rest or safety position. The struts have generally employed a bifurcated engaging means whereby an engagement is made at two contact points generally symmetrical to the pivot point of the hammer pin and the hammer is "rocked" into a safety position. This type of rebound cam assembly is exemplified in U.S. Pat. No. 3,988,849.
Additionally, prior multibarrel handguns have provided means for sequentially firing the barrels. This sequential firing has been frequently accomplished in part by means of mounting a firing element on a ratchet, which rotates on the hammer so as to sequentially align with the firing pins during firing.
Unfortunately, multibarrel handguns employing sequential firing mechanisms have exhibited firing malfunctions, such as a machine gunning effect whereby one pull of the trigger results in a rapid sequential firing of all of the barrels of the firearm. The result of this rapid sequential fire is exacerbated with high-power ammunition and frequently results in violent recoil forces often endangering the firearm user and severely affecting the accuracy and effectiveness of the handgun.
SUMMARY OF THE INVENTION
This invention provides a new and improved strut assembly means whereby the strut is forceably engaged with the hammer assembly at only one point prior to firing and the hammer assembly is permitted to return to the at-reset or safety position when the strut is stopped against the hammer pivot. This feature considerably reduces the chances of misfire, since the conventional rocking engagement of the cam strut frequently compresses the strut spring on the rebound resulting in a diminished forward hammer thrust. The diminished forward thrust can result in a misfire. Additionally, the improved strut assembly permits the attainment of a neutal positioning of the hammer after firing.
This invention further provides a new and improved method for indexing and rotating the ratchet on a multibarrel firearm in part by employing notches on a ratchet both to facilitate the rotation of the ratchet and to position the firing lug on the ratchet in alignment with an associated cartridge chamber. This improvement allows for easier alignment during assembly process, makes the operation of the firearm more efficient during the firing process and reduces the manufacturing expense, since fewer assembly elements are necessary.
This invention further provides for a new and improved mechanism which acts to eliminate machine gunning by means of an outwardly projecting lug on the trigger assembly. The lug prevents the pawl or hand which rotates the ratchet and hence the firing plate, from rotating the firing lug to a new position so as to align with a chamber containing an unfired cartridge until the trigger has been fully returned to the safety or at-rest position.
An object of the invention is to provide a new and improved means for aligning the firing lug with the firing pins or cartridge chambers in a multibarrel handgun.
Another object of the invention is to provide a new and improved means of sequentially firing a multibarrel handgun.
A further object of the invention is to provide a mechanism for preventing the machine gunning effect upon initial firing of the handgun.
A still further object of the invention is to provide certain improvements in the form, construction and arrangement of the several parts whereby the above-named and other objects may effectively be attained.
The invention accordingly comprises the features of construction, combinations of elements, and arrangement of parts which will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view of a four-barrel handgun;
FIG. 2 is a vertical sectional view along the lines 2--2 of FIG. 1 showing the gun in an at-rest position, parts being broken away;
FIG. 3 is a vertical sectional view along the line 3--3 of FIG. 2 looking toward the rear of the handgun;
FIG. 4 is a detailed vertical sectional view along the line 4--4 of FIG. 2 looking toward the front of the handgun;
FIG. 5 is a detailed sectional view of the ratchet and part of the hammer assembly along the line 5--5 of FIG. 3; and
FIG. 6 is a detailed view similar to FIG. 2 showing the hammer and trigger in cocked position, parts being broken away.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, the handgun has a frame 10 which includes the grip portion 14, the breech portion 16, the barrel portion 12, trigger guard 18 and the barrel mounting portion 20. The frame 10 is centrally recessed as indicated at 19 to receive the trigger assembly 17, hammer assembly 59 and the strut assembly 58. A pair of mounting slots 135, which open outwardly and upwardly from the barrel mounting portion 20, receive a pair of mounting tongues 132 of the barrel assembly 12.
The barrel assembly 12 consists of four cylindrical barrels 15 extending the length of the assembly from an exit end 116 to a cartridge chamber at the cartridge receiving end 117, said barrels being arranged in pairs side by side, with one pair being mounted on top of the other. The barrel assembly 12 is mounted on the pair of mounting tongues 132, which are pivoted on a barrel pivot pin 130 inserted through the barrel mounting portion 20 and mounting slots 135. A front sight 140 is mounted at the top of the exit end 116 of the barrel assembly. A release groove 115 is formed in the top of the barrel assembly at the cartridge receiving end 117. Said release groove is adapted to receive a latch plate 118.
An extractor bore 123 which is parallel to the barrels 15 and centrally positioned with respect to said barrels 15 opens rearwardly to a central recess 119 in the cartridge receiving end 117. The extractor bore 123 slidably receives an extractor guide 122, orthogonally connected to an extractor plate 120, so that the guide 122 and plate 120 may be received in the central recess in general alignment with the barrels and cartridge chambers at the cartridge receiving end 117. The vertical extractor plate 120 extends below the barrels 15 to connect to a horizontally disposed extractor push rod 126. The extractor push rod 126 is slidably retained on the barrel assembly by means of a guide pin 127, which supports the extractor push rod 126 between the mounting tongues 132. The extractor push rod 126 is provided with a recess 125 to receive the pin 127, the horizontal dimensions of said recess 125 defining the limits of the sliding of the push rod 126, and hence the movement of the extractor plate with respect to the barrel assembly. As the barrel assembly 12 is pivoted from its closed position to an open position, the end of the barrel mounting portion 20 contacts with the push rod end 129 imparting a sliding movement to the extractor 126, and causing the extractor plate 120 to move rearwardly with respect to the barrels at the cartridge receiving end 117, thus facilitating the removal of spent cartridges from the cartridge chambers.
In a closed position, the cartridge receiving end 117 is adjacent the breech portion 16. The barrel assembly is secured in a closed position by the engagement of the latch plate 118 in the release groove 115 of the barrel assembly. The latch plate 118 is biased toward a forward position by means of a spring 114. The barrel assembly is opened by forcing a latch release 112 toward the rear of the frame, thus removing the latch plate from the release groove 115 and allowing the barrel assembly 12 to be pivoted to an open position.
A trigger 22 is slidably mounted at its top in a mounting groove 32 and at its bottom in a trigger guard groove 31, said grooves being horizontally disposed. At the rear, the trigger 22 has a bifurcated end consisting of an upper segment 21 and a lower segment 23. A trigger groove 24 formed in the bottom of the trigger 22 extends through the bottom of the lower segment 23 and is adapted to receive a trigger spring 28. The trigger spring 28 is mounted on one end around a trigger spring guide rod 26, which is held in a rod recess 55 of the frame 10 by the force of the spring. The other end of the trigger spring 28 extends into the trigger groove 24, so as to urge the trigger toward the front of the handgun. The forward movement of the trigger is limited by the trigger groove end 51 and the mounting groove end 52. Thus, the trigger is supported in the frame for movement between a ready position, shown in full lines in FIG. 2, and a firing position shown in FIG. 6.
The upper edge of the rear segment 21 of the trigger is recessed to form a bottom surface 29 having at its forward end a notch 30 and a rearwardly facing end wall 27 adjacent to a trigger top surface 25. An outwardly projecting lug 35 is mounted on the side near the rear end of the upper segment 21 of the trigger.
The hammer assembly 59 comprises a hammer 60 pivotally mounted at its lower end on a hammer pivot pin 62, extending through each side of the frame 10 and through a pivot bore 64 in the hammer. Near the top of the hammer 60 a horizontally disposed hammer bore 65 extends from the percussion side to the back side of the hammer 60. A sear plunger bore 67 opens upward into the hammer bore 65. The sear plunger bore 67 is adapted to receive a sear plunger 43 in the form of a ball, which is received beneath a sear plunger spring 45, so that the sear plunger 43 is urged in a downward direction.
A detent bore 96, parallel to the hammer bore 65, opens outward on the percussion side of the hammer. The detent bore is adapted to receive a ball detent mechanism which includes a spring 97 and a detent 99 in the form of a ball urged by the spring in an outward direction toward the front of the handgun.
The firing element or ratchet 90 comprises a disc 93 integral with a hub 98, which is rotatable in the hammer bore 65. Opposite the hub 98, the circular ratchet rim 92 has on its outer circumference a radially projecting firing lug 91.
The ratchet, and in particular the firing lug 91, is adapted to make contact with firing pins 104 in a breech block 100 hereinafter described. The outside diameter of the ratchet rim is generally commensurate with the diameter of the firing pin retainer washer 106, hereinafter described. The inside diameter of said rim is greater than the diameter of the head of retaining pin 108, hereinafter described, and the height of said rim is greater than the longitudinal dimension of the head of pin 108.
Four symmetrically spaced notches 94 around the circumference of the ratchet disc face toward the hub side of the ratchet. The ratchet is mounted on the hammer 60 by inserting the ratchet hub 98 through the hammer bore 65 and securing the end of the hub by means of a retaining ring 95, so that the ratchet rim faces toward the front of the handgun. The notches are in circumferential positions to receive the ratchet plunger as it is urged forward, and the ratchet is in general alignment with the breech block 100 when the hammer is in the at-rest position as shown in FIG. 2.
Below the sear plunger 43, a sear recess 41 opens downward and extends through both the percussion side and the back side of the hammer. The sear 40 is received in the sear recess 41 and pivotally connected to the hammer by means of a sear pivot pin 42. The sear 40 extends through the concussion side and is disposed in a generally horizontal position. The sear 40 has an upper sear cam surface 44 and a bottom surface 48 adjacent to a sear end surface 46. The sear is urged downward by means of the sear plunger 43 being forced against the sear cam surface 44. In the at-rest position, as shown in FIG. 2, a sear edge 49 which is at the intersection of the sear end surface 46 and the sear bottom surface 48, rests on the trigger recess bottom 29.
A strut slot 57 formed in the bottom of the hammer 60 opens outwardly through the back side, so as to receive a hammer strut 70. The hammer strut 70 comprises a generally "T" shaped a yoke 73 on one end and a strut retaining end 76 at the other end. The front of the yoke contains a strut seat 71 and a stop seat 72, the seat 71 being forced against a pin 61 located on the hammer above and parallel to the hammer pivot pin 62 by the strut spring 75. The rear end of said strut spring 75 is fitted on a base 78, in a recess 54 in the rear portion of the frame 10. The strut extends through the central axis of the spring 75 with the end 76 being retained in the recess 79 in the base, so that the bias of the spring 75 urges the strut 70 in a forward direction, with the seat and 72 biasing against the pin 62 when the triger and hammer are in an at-rest position, as shown in FIG. 2.
An indexing pawl or hand 80 is pivotally connected to the frame 10 by a pivot pin 82 and is urged in a forward direction by a torsion spring 86 mounted on the pivot pin 82 so that one end of the spring bears against a spring retainer 84 and the other end against the interior of the frame, thus urging the pawl or hand in a forward direction. The free end of the pawl is adapted to engage in the notch 94 when the hammer and trigger are in an at-rest position, as shown in FIG. 2.
The breech block 100 vertically disposed between the barrel assembly 12 and the central recess 19 is in general horizontal alignment with the ratchet 90. Four horizontal symmetrically placed stepped concentric bores 102 in the breech block are axially aligned with the centers of the respective barrels 15 at the cartridge receiving end 117 when the barrel assembly 12 is in the closed position.
A firing pin 104 is received in each of the firing pin bores 102. The head of each firing pin is cut away at 107 so that the firing pins may be secured in the breech block by means of a firing pin retaining washer 106, which is fastened to the breech block by a threaded retaining pin 108, as shown in FIGS. 4 and 6. The firing pin/retaining washer configuration allows for a small degree of movement of the firing pin 104 in the firing pin bore 102. The firing pins are in general alignment with the ratchet 90 when the hammer is in a firing position, which position is not shown in the drawings.
During firing, the firing lug 91 on the ratchet makes contact with one of the four firing pins 104. The ratchet may be suitably rotated so that the firing lug is in successive sequential alignment with each of the firing pins 104. It may thus be seen that it is necessary that the firing plate 91 be positioned in one of four circumferential positions on the ratchet, so as to obtain required alignment between the firing lug 91 and each firing pin 104.
The rotation and incremental positioning of the ratchet is accomplished by means of the unique utilization of the notches 94 to both facilitate rotation and secure correct positioning. The ratchet plunger, situated in the hammer shaft, forces a plunger ball into one of the four notches 94 circumferentially arranged around the ratchet. The plunger 99 will engage each of the notches upon rotation of the notch to a position in the vicinity of the plunger bore 96, thus securing the firing lug 91 at one of four positions or striking locations, each of which will be in alignment with a corresponding firing pin 104 of the breech block 100. The seating of the plunger in the bottom of each notch effects fine adjustment of the ratchet in each of the four operative positions.
Each notch 94 is defined by a slant surface 103 which is inclined outwardly and away from a surface 105 which is perpendicular to the face of the disc 93 and extends radially outward. When a notch is aligned with the plunger 99, the plunger is forced into the notch. Because of the relatively lower resistance to disengagement by the slant surface 103 as opposed to the surface 105, rotational movement of the ratchet is unidirectional. In operation, the barrel assembly 12 is moved to an open position by forcing the latch release 112 toward the rear of the gun and pivoting the barrel assembly on the barrel pivot pin 103. Cartridges are placed in each of the cartridge chambers at the cartridge-receiving end 117 of the barrel assembly. The barrel assembly is then pivoted back to a generally horizontal position and the latch plate 118 is secured in the release groove 115.
The hammer strut 70 does not exert biasing force upon the hammer 60 when the gun is at rest, as shown in FIG. 2. The hammer is supported for limited pivotal movement about the axis of the pin 62 and generally toward and away from the breech block free of the influence of the hammer strut 70 and the strut spring 75, as it appears in FIG. 2. Thus, the firing pins are slidably movable within the breech block free of influence of the strut assembly 58. However, the pawl 80 which is biased toward the striking position and into engagement with the firing element 90 by the spring 94, acts through the firing element to bias the hammer toward its striking position when the trigger is in its ready position and during initial movement of the hammer toward its releasing position in response to movement of the trigger toward its firing position. This arrangement allows any firing pin which may project beyond the face of the breech block to be freely cammed rearwardly within the breech block and to a position flush with the breech block face when the barrel assembly is pivoted to and latched in its closed position.
The handgun is fired by drawing the trigger 22 toward the rear of the handgun from an at-rest position to its firing position as exemplified in FIG. 2 past a cocked position, which is exemplified in FIG. 6. The forcing of the trigger toward the rear of the handgun results in a relative position change in the hammer 60, the strut 70, the sear 40, the pawl 80 and the ratchet 90, all of which act in a coordinated movement so as to fire the handgun.
In the at-rest position shown in FIG. 2, the sear edge 49 rests on the bottom 29 of the trigger recess. As the trigger slides rearward, the sear edge 49 slides into the recessed notch 30 of the trigger. Further movement of the trigger results in contact between the sear end 46 and the recess end 27. The sear plunger 43 urges the sear 40 downward thus securing a firm engagement of the sear end 46 and the sear edge 49 with the recess edge 27 and the recess notch 30. Further movement of the trigger exerts a rearward force on the hammer 60, which is pivotally engaged to the frame by the pivot pin 62 resulting in a rearward pivot of the hammer toward the back of the frame to its releasing position.
As the hammer pivots around the pivot pin 62, the stop seat 72 loses contact with the pivot pin 62 while contact remains with the strut seat 71 and the pin 61, as shown in FIG. 6. The strut spring 75 is further compressed, and the strut retaining end 76 is forced further into the recess 79.
In the at-rest position of FIG. 2, the pawl 80 is engaged in the notch 94 near the bottom of the ratchet, the pawl being biased in a forward direction. As the hammer pivots, the notch surface 83 of the pawl is forced against the surface 105 of a lower notch 94. Further pivoting of the hammer results in the pawl 80 being forced in an upward direction with respect to the hammer and the ratchet thus imparting a rotational movement to the ratchet. The path of the pawl-engaging surface travels upward through a pawl slot 63 extending through the top of the hammer so that the slot is aligned with an upper-fixed position of a notch. At the top of the path, the surface 105 is parallel and adjacent the sides of slot 63 so that the pawl no longer engages the surface in an oblique upward type of contact, but slides upwardly along the surface 105, thus terminating the rotational force created by the notch-engaging surface 83 on the pawl-receiving surface of the notch 94. Upon termination of rotation, the ratchet plunger 99 engages a notch 94 and holds the ratchet in a new fixed position. The end of the pawl or hand is now biased to slide down and engage the next lower notch at such time as the hammer resumes a forward pivot position.
The pivoting of the hammer also results in a relative change in position of the sear 40 with respect to the trigger 22. Being pivotally connected to the hammer 60 the sear 40, upon rearward pivot of the hammer, will eventually assume a position in which the sear bottom 48 is generally lower than that of the trigger recess bottom 29. Thus, the sear bottom 48 will ride up and come into contact with the recess bottom 29, and the position of the sear edge 49 will rise relative to the recess end 27. Further movement of the trigger will result in a position where the sear edge 49 will clear the top of the recess end 27 and will thus slide along the trigger top surface 25, so that the sear bottom 48 rests on the top surface 25. At this point, the force acting to pivot the hammer toward the rear, which force is exerted on the hammer 60 by means of the force of the movement of the trigger transferred rearward through the sear, is terminated by virtue of the release of the engagement of the sear end and the recess end.
The dominant force is now exerted by the strut spring 75 acting against the yoke 73 to force the strut seat 71 against the pin 61. The latter force thrusts the hammer in a forward pivoting direction to a striking position resulting in one of the firing pins 104 being struck by the forward thrust of the previously aligned firing lug 91 thereby firing one of the cartridges. The hammer is free to return to the at-rest position as shown in FIG. 2.
A machine-gunning effect is prevented by a disabling means or lug 35 which projects outwardly from the side of the rear end of the upper segment 21 of the trigger. The lug prevents the pawl or hand 80 from returning to a position so as to engage a lower notch 94 while the trigger is in a "fired" position; therefore, the ratchet 90 and hence firing lug 91 secured in position by the ratchet plunger 99 cannot be further rotated to align and contact another firing pin until the trigger is moved to its at-rest position and pulled a second time.
The barrel assembly 12 may be opened by pivoting the barrel assembly on the barrel pivot pin 130. The opening of the barrel assembly causes the extractor guide and hence the extractor 120 to move relative to the barrels 15, thus forcing the ends of the spent cartridges from the barrel.
It will thus be seen that the objects set forth above among those made apparent from the preceding description are efficiently obtained, and since certain changes may be made in the above construction without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. | A new and improved handgun providing a strut assembly which engages the hammer assembly at two contact points, one of which is at the hammer pivot point which acts as a stop. An improved sequential firing mechanism is disclosed making use of notches on a ratchet engaged by a detent to secure proper alignment and positioning of the hammer firing mechanism with the firing pin. The invention also provides a safety mechanism for preventing the accidental firing of additional shots in a multibarrel handgun. | 5 |
RELATED APPLICATIONS
This application is a Divisional application of application Ser. No. 09/897,176, filed Jul. 2, 2001, Now U.S. Pat. No. 6,412,336 entitled SINGLE RISER/SINGLE CAPILLARY BLOOD VISCOMETER USING MASS DETECTION OR COLUMN HEIGHT DETECTION, which in turn is a Continuation-In-Part of application Ser. No. 09/789,350, filed Feb. 21, 2001, entitled Mass Detection Capillary Viscometer, now abandoned, which in turn is based on Provisional Application Serial No. 60/228,612 filed Aug. 29, 2000 entitled MASS DETECTION CAPILLARY VISCOMETER. This application is also a Continuation-in-Part of application Ser. No. 09/573,267 filed May 18, 2000, now U.S. Pat. No. 6,402,703 entitled DUAL RISER/SINGLE CAPILLARY VISCOMETER. The entire disclosures of all the above applications are incorporated by reference herein.
BACKGROUND OF THE INVENTION
A capillary viscometer is commonly used because of its inherent features such as simplicity, accuracy, similarity to process flows like extrusion dies, no free surface, etc. Viscous flow in capillary viscometry is firmly established both theoretically and experimentally. C. W. Macosko, Rheology: Principles, Measurements, and Applications (VCH, 1993). In fact, the capillary viscometer was the first viscometer and this device remains the most common for measuring viscosity for polymer solutions and other non-Newtonian fluids. However, most existing capillary viscometers produce viscosity measurement a shear rate at a time. In the case of Newtonian fluids the observation of the rate of flow at a single pressure drop is sufficient to define the flow behavior. However, in the case of non-Newtonian fluids, viscosity measurements need to be performed over a range of shear rates. In order to measure viscosity over a range of shear rates, it is necessary to repeat the measurement by varying either the driving pressure head or the capillary tube diameter, which leads to a time-consuming measurement requiring intensive labor. Hence, these methods are not suited for measuring the rheology of polymer fluids that may exhibit shear-dependent viscosities. Furthermore, application of such techniques often requires relatively large volumes of the test fluids. Therefore, there has been a need to develop a simple and labor-free viscometer which can measure the viscosity of fluids over shear rates at a time.
In U.S. Pat. No. 6,019,735 (Kensey et al.) and U.S. Pat. No. 6,077,234 (Kensey et al.), which are assigned to the same Assignee, namely Visco Technologies, Inc., of the present invention, there is disclosed a scanning-capillary-tube viscometer for measuring the viscosity of a fluid, e.g., circulating blood of a living being. Among other things, this scanning capillary tube viscometer discloses an apparatus that monitors the changing height of a column of fluid versus time in a riser that is in fluid communication with a living being's circulating blood. A further improvement of this type of scanning capillary tube viscometer is disclosed in application Ser. No. 09/439,735 entitled DUAL RISER/SINGLE CAPILLARY VISCOMETER, which is assigned to the same Assignee as the present invention, namely, Visco Technologies, Inc. and whose entire disclosure is incorporated by reference herein. In that application, a U-shaped tube structure is utilized that generates a falling and rising column of test fluid that is driven by a decreasing pressure differential for moving these columns of fluid through a plurality of shear rates, which is necessary for non-Newtonian fluid (e.g., blood) viscosity determinations. Such an apparatus can produce viscosity data in a low shear range (e.g., approximately 0.02 s −1 ).
However, there is a need for an alternative mechanism of monitoring the changing column of fluid over time, such as detecting the changing mass of the column of fluid, as set forth in the present application. The key principle of the mass-detection-capillary viscometer is that both flow rate and pressure drop at a capillary tube can be determined by a single measurement of collected fluid mass variation with time using a load cell. Thus, there also remains a need to develop a viscosity determination in a quasi-steady capillary flow and to measure the viscosity of non-Newtonian fluids (e.g., polymer solutions, circulating blood of a living being, etc.) over a range of shear rates.
SUMMARY OF THE INVENTION
An apparatus for determining the viscosity of the circulating blood of a living being over plural shear rates using a decreasing pressure differential. The apparatus comprises: a lumen (e.g., a riser tube) being positioned at an angle to a horizontal reference greater than zero degrees, wherein the lumen comprises a first end and a second end and wherein the first end is exposed to atmospheric pressure and wherein the lumen comprises a first known dimension (e.g., the diameter of the lumen); a flow restrictor (e.g., a capillary tube) having an inlet and an outlet wherein the outlet is arranged to deliver any blood that passes therethrough to a collector, and wherein the flow restrictor includes some known dimensions (e.g., the length and diameter of the flow restrictor); a valve coupled to the vascular system of the living being at a first port and wherein the valve comprises a second port coupled to the second end and a third port is coupled to the inlet; a sensor for detecting the movement of the blood over time (e.g., a mass detector, a column level detector, etc.) through the apparatus and wherein the sensor generates data relating to the movement of the blood over time; a processor, the valve to create a column of blood in the first lumen and the flow restrictor and to establish a pressure differential between the first end and the outlet, and wherein the column of blood moves through the lumen and the flow restrictor at a first shear rate caused by the pressure differential and wherein the movement of the column of blood causes the pressure differential to decrease from the first shear rate for generating the plural shear rates; and wherein the processor calculates the viscosity of the blood based on the data relating to the movement of the column of blood over time, the first known dimension of the lumen and the some known dimensions of the flow restrictor.
A method for determining the viscosity of the circulating blood of a living being over plural shear rates caused by a decreasing pressure differential. The method comprises the steps of: (a) providing a lumen having a first end and a second end and positioned at an angle to a horizontal reference greater than zero degrees, and wherein the lumen has a first known dimension (e.g., the diameter of the lumen) and wherein the first end is exposed to atmospheric pressure; (b) diverting a portion of the circulating blood into the lumen through the second end to form a column of blood therein; (c) coupling an inlet of a flow restrictor to the second end of the lumen to establish a pressure differential between the first end and the outlet and wherein the flow restrictor has an outlet that is arranged to deliver any blood that passes therethrough to a collector and wherein the flow restrictor has some known dimensions (e.g., the length and the diameter of the flow restrictor); (d) controlling the column of blood to form a continuous column of blood in the lumen and the flow restrictor, and wherein the column of blood moves through the lumen and the flow restrictor at a first shear rate caused by the pressure differential and wherein the movement of the column of blood causes the pressure differential to decrease from the first shear rate for generating the plural shear rates; (e) providing a sensor for detecting the movement of the column of blood over time (e.g., a mass detector, a column level detector, etc.) as the column of blood moves and passes from the outlet into the collector while maintaining the outlet submerged in blood that has collected in the collector, and wherein the sensor generates data regarding the movement; and (f) calculating the viscosity of the blood based on the generated data, the first known dimension and the some known dimensions.
An apparatus for determining the viscosity of the circulating blood of a living being over plural shear rates using a decreasing pressure differential. The apparatus comprises: a lumen (e.g., a riser tube) being positioned at an angle to a horizontal reference greater than zero degrees, and wherein the lumen comprises a first end and a second end and wherein the lumen also comprises a first known dimension (e.g., the diameter of the lumen); a flow restrictor (e.g, a capillary tube) having an inlet and an outlet wherein the outlet is arranged to deliver any blood that passes therethrough to a collector and wherein the inlet is coupled to the second end and wherein the flow restrictor includes some known dimensions (e.g., the length and diameter of the flow restrictor); a valve coupled to the vascular system of the living being at a first port and wherein the valve comprises a second port coupled to the first end; a sensor for detecting the movement of the blood over time (e.g., a mass detector, a column level detector, etc.) through the apparatus and wherein the sensor generates data relating to the movement of the blood over time; a processor, coupled to the valve and the sensor wherein the processor is arranged to operate the valve to create a column of blood in the first lumen and the flow restrictor and to establish a pressure differential between the first end and the outlet and wherein the column of blood moves through the lumen and the flow restrictor at a first shear rate caused by the pressure differential and wherein the movement of the column of blood causes the pressure differential to decrease from the first shear rate for generating the plural shear rates; and wherein the processor calculates the viscosity of the blood based on the data relating to the movement of the column of blood overtime, the first known dimension of the lumen and the some known dimensions of the flow restrictor.
A method for determining the viscosity of the circulating blood of a living being over plural shear rates caused by a decreasing pressure differential. The method comprises the steps of: (a) providing a lumen (e.g., a riser tube) having a first end and a second end and positioned at an angle to a horizontal reference greater than zero degrees and wherein the lumen has a first known dimension (e.g., the diameter of the lumen); (b) coupling an inlet of a flow restrictor (e.g., a capillary tube) to said second end and arranging an outlet of the flow restrictor to deliver any blood that passes therethrough to a collector and wherein the flow restrictor has some known dimensions (e.g., the length and diameter of the flow restrictor); (c) diverting a portion of the circulating blood into the lumen through the first end to form a column of blood in the lumen and the flow restrictor and to establish a pressure differential between the first end and the outlet; (c) exposing the first end to atmospheric pressure to cause the column of blood to move through the lumen and the flow restrictor, wherein the movement of the column of blood causes the pressure differential to decrease from the first shear rate for generating the plural shear rates; (d) providing a sensor for detecting the movement of the column of blood over time (e.g., a mass detector, a column level detector, etc.) as the column of blood moves and passes from the outlet into the collector while maintaining the outlet submerged in blood that has collected in the collector and wherein the sensor generates data regarding the movement; and (e) calculating the viscosity of the blood based on the generated data, the first known dimension and the some known dimensions.
An apparatus for determining the viscosity of the circulating blood of a living being over plural shear rates using a decreasing pressure differential. The apparatus comprises: a first lumen (a riser tube) being positioned at an angle to a horizontal reference greater than zero degrees and wherein the lumen comprises a first end and a second end and wherein the first end is exposed to atmospheric pressure and wherein the lumen comprises a first known dimension (e.g., the diameter of the first lumen); a flow restrictor (e.g., a capillary tube) having an inlet and an outlet wherein the inlet is coupled to the second end and wherein the flow restrictor includes some known dimensions (e.g., the length and diameter of the flow restrictor); a valve coupled to the vascular system of the living being at a first port wherein the valve comprises a second port coupled to the outlet and a third port coupled to an input of a second lumen (e.g., an adaptor, etc.) arranged to deliver any blood that passes therethrough to a collector through an output of the second lumen; a sensor for detecting the movement of the blood over time (e.g., a mass detector, a column level detector, etc.) through the apparatus and wherein the sensor generates data relating to the movement of the blood over time; a processor, coupled to the valve and the sensor and wherein the processor is arranged to operate the valve to create a column of blood in the first lumen and the flow restrictor and to establish a pressure differential between the first end and the output wherein the column of blood moves through the lumen and the flow restrictor at a first shear rate caused by the pressure differential and wherein the movement of the column of blood causes the pressure differential to decrease from the first shear rate for generating the plural shear rates; and wherein the processor calculates the viscosity of the blood based on the data relating to the movement of the column of blood over time, the first known dimension of the first lumen and the some known dimensions of the flow restrictor.
DESCRIPTION OF THE DRAWINGS
The invention of this present application will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
FIG. 1 is a block diagram of a single riser/single capillary (SRSC) blood viscometer using mass detection which is also referred to as a mass detection capillary blood viscometer (MDCBV);
FIG. 1A is a height vs. time plot of the blood column in the riser tube of the MDCBV;
FIG. 1B is a mass vs. time plot of the blood as it is collected in the collector of the MDCBV;
FIG. 2 is a front view of an embodiment of the MDCBV;
FIG. 3 is a side view of the MDCBV;
FIG. 4 is a functional diagram of the MDCBV;
FIG. 5A is a functional diagram of the valve activated to create a column of blood;
FIG. 5B is a functional diagram of the valve activated to permit the column of blood to fall and be collected in a collector;
FIG. 5C is a functional diagram of the valve activated to halt all motion of the column of blood;
FIG. 5D is a functional diagram of the valve activated to permit the column of blood to fall while data is taken as the collector receives the increasing amount of blood;
FIG. 6 is a functional diagram of a second embodiment of the MDCBV having an alternative position of the capillary tube;
FIG. 7 is a functional diagram of a third embodiment of the MDCBV having an alternative position of the valve mechanism;
FIG. 8A is a functional diagram of the valve mechanism of FIG. 7 activated to create a column of blood;
FIG. 8B is a functional diagram of the valve mechanism of FIG. 7 activated to permit the column of blood to move and be collected in a collector;
FIG. 9 depicts a fourth embodiment of the MDCBV wherein the changing mass of falling column of blood is detected;
FIG. 10 depicts the mass vs. time plot the falling column of blood for the fourth embodiment of FIG. 9;
FIG. 11 is a block diagram of a SRSC blood viscometer using a column height detector known as a column height detection capillary (CHDC) blood viscometer wherein the changing height of a falling column of blood is monitored;
FIG. 12 is a front view of an embodiment of the CHDC blood viscometer;
FIG. 13 is a functional diagram of the CHDC blood viscometer;
FIG. 14 is a functional diagram of a second embodiment of the CHDC blood viscometer having an alternative location of the flow restrictor; and
FIG. 15 is a functional diagram of a third embodiment of the CHDC blood viscometer having an alternative location of the valve mechanism.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention, generally referred to as a single riser/single capillary (SRSC) blood viscometer, uses a single riser tube and a single flow restrictor (e.g., a capillary tube) structure for determining the viscosity of the circulating blood of a living being.
Although the SRSC blood viscometer can be implemented in a number of ways, two exemplary apparatus/methods are set forth below. The first implementation uses the SRSC structure along with mass detection and hence is hereinafter referred to as a mass detection capillary blood viscometer (MDCBV) 20 . The second implementation uses the SRSC structure along with column height detection and hence is hereinafter referred to as a column height detection capillary (CHDC) blood viscometer 1020 .
Referring now in detail to the various figures of the drawing wherein like reference characters refer to like parts, there is shown at 920 a mass detecting capillary blood viscometer (MDCBV).
The MDCBV 920 basically comprises a blood receiver 922 and an analyzer/output portion 924 . The patient is coupled to the MDCBV 920 through a circulating blood conveyor 926 , e.g., a needle, an IV needle, an in-dwelling catheter, etc., or any equivalent structure that can convey circulating blood from a patient to the MDCBV 920 . As will be discussed in detail later, the analyzer/output portion 924 provides a display 28 for presenting the viscosity information, as well as other information to the operator. The analyzer/output portion 924 may also provide this information to other suitable output means 330 , such as a datalogger 332 , other computer(s) 334 , a printer 336 , a plotter 338 , remote computers/storage 340 , to the Internet 342 or to other on-line services 344 .
The blood receiver 922 basically comprises a valve mechanism 946 coupled to a riser tube R on one side and coupled to a flow restrictor 24 (e.g., a capillary tube) on the other side. The output of the flow restrictor 24 is directed into a fluid collector 26 via an adaptor 34 . When the blood conveyor 926 is coupled to the blood receiver 922 , the valve mechanism 946 controls the flow of blood into the blood receiver 922 , as will be discussed in detail later. The upper end of the riser tube R is exposed to atmospheric pressure. The riser tube R may be positioned at any non-zero angle to a horizontal reference position (e.g., the datum line as shown in FIG. 4 ); one exemplary position is at a vertical orientation with respect to the datum line as shown in FIG. 4 .
It should be understood that the blood receiver 922 may be disposable or non-disposable. As will be discussed in detail later, where the blood receiver 922 is disposable, the components (valve mechanism 946 , riser tube R and flow restrictor 24 ) are releasably secured in a blood receiver housing 962 that can be quickly and easily inserted, used during the viscosity test run and then quickly and easily removed for disposal; another disposable blood receiver 922 is then inserted in preparation for the next viscosity test run. On the other hand, where the blood receiver 922 is non-disposable, the components (valve mechanism 946 , riser tube R and flow restrictor 24 ) can be thoroughly washed and cleaned in place in preparation for the next viscosity test run.
It should be understood that the flow restrictor 24 does not necessarily have to be an elongated tube but may comprise a variety of configurations such as a coiled capillary tube.
The analyzer/output portion 924 basically comprises a mass detector 28 , a level detector 400 , a processor 30 , the display 928 , a bar code reader 978 , an environmental control unit 980 , and overflow detector 981 , a first battery B 1 and a second back-up battery B 2 . The fluid collector 26 is positioned on top of the mass detector 28 which monitors the increasing mass of blood collecting in the fluid collector 26 . The overflow detector 981 ensures that when the column of blood is generated, no blood overflows the riser R. The processor 30 (e.g., a “386” microprocessor or greater, or any equivalent) is arranged to analyze the data from the mass detector 28 and to calculate the blood viscosity therefrom, as will also be discussed in detail later. Furthermore, the processor 30 also controls the display 928 for providing the viscosity information and the other information to the operator as well as to the other output means 330 . The processor 30 also controls the valve mechanism 946 based on the data from the mass detector 28 , as will be discussed later. Battery B 1 provides all of the requisite power to the analyzer/output portion 24 , with battery B 2 serving as a back-up power supply. The bar code reader 978 , the environmental control unit 980 and the level detector 400 will be described later.
In general, via the use of the valve mechanism 946 , a column of blood 38 is initially generated in the riser R and then that column of blood 38 is permitted to fall through the riser tube R, through the flow restrictor 24 and into the fluid collector 26 . This movement of blood can be represented by a height vs. time relationship (FIG. 1A) with regard to the column of blood in the riser R and by a mass vs. time relationship (FIG. 1B) with regard to the blood being received in the fluid collector 26 .
As shown more clearly in FIGS. 2-3, the preferred embodiment of the MDCBV 920 comprises the blood receiver 922 and the analyzer/output portion 924 contained in respective housings 960 and 962 , each of which can be releasably secured to a common frame, e.g., a conventional intravenous (IV) pole 48 . In this configuration, the analyzer/output portion 924 can be positioned in an inclined orientation (see FIG. 3) to facilitate user operation and viewing of the display 928 . However, it should be understood that the respective housing constructions are exemplary, and others can be incorporated without limiting the scope of this invention.
The display 928 may comprise any suitable conventional devices, e.g., an ELD (electroluminescent display) or LCD (liquid crystal display) that permits the visualization of both text and graphics. The resolution of this display 928 is preferably 800×600 VGA or above. Furthermore, while the preferred embodiment utilizes a touch screen display which incorporates, among other things:
graphical display 961
instruction, and/or data, display 965 (which also includes the command line display shown as “RUN TEST”; e.g., “TESTING”, “TEST IN PROGRESS,” etc.)
alphanumeric keypad 968
emergency stop button 970
battery status indicators, 972 A and 972 B
function buttons 974 ,
it should be understood that any equivalent display device is within the broadest scope of the invention. Thus, any number of user interfaces and buttons may be available through the display 928 . Therefore the invention 920 is not limited to the embodiment that is shown in FIG. 2 . Moreover, the display 928 can be operated to minimize or maximize, or overlay any particular graphic or text screen, as is available in any conventional object-oriented operating system, such as Microsoft™ WINDOWS.
The lower housing 960 comprises the blood receiver 922 and the mass detector 28 . In the preferred embodiment, the mass detector 28 may comprise a precision balance, or load cell, such as The Adventurer™ by Ohaus Corporation of Florham Park, N.J. Thus, as the collector 26 collects more of the blood during the viscosity test run, the changing mass value is transmitted to the processor 30 from the mass detector 28 for viscosity determination; in particular, the mass detector 28 generates an electrical signal that corresponds to the mass variation in time. It should be understood that the term “mass” may be interchanged with the term “weight” for purposes of this invention. It should also be understood that the connection between the mass detector 28 and the processor 30 is bi-directional; this allows the processor 30 to reset the mass detector 28 in preparation for a new test run.
It should also be understood that although it is preferable to have the riser tube R in a vertical position, it is within the broadest scope of this invention to have the riser tube R oriented at any angle greater than zero degrees, with respect to a horizontal reference (e.g., datum line shown in FIG. 4 ).
Where the blood receiver 922 is disposable, it is releasably secured in the housing 960 such that once a test run is completed and/or a new patient is to be tested, all of the lumens (e.g., the riser tube R, the capillary 24 , the adaptor 34 and the valve mechanism 946 ) can be easily/quickly removed, disposed of and a new set inserted. For example, a bracket 147 (FIG. 2) may be used to releasably secure the upper portion of the riser tube R.
A door 976 (which can be vertically or horizontally hinged to the housing 960 ) is provided to establish a temperature-controlled environment during the test run. In particular, the door 976 also supports an environmental control unit 980 (e.g., a heater, fan and/or thermostat) such that when it is closed in preparation for the test, the flow restrictor 24 is then heated (or cooled) and maintained throughout the test run at the same temperature and environment as the living being. Prior to the run, the living being's temperature is taken and the operator enters this temperature (via the touch screen display 928 ). The environmental control unit 980 then operates to achieve and maintain this temperature. It should be noted that it is within the broadest scope of this invention to include a environmental control unit 980 that achieves and maintains the entire blood receiver 922 at the patient's temperature during the run. By properly maintaining the temperature throughout the test run, the effects of any temperature variation in the viscosity measurement is minimized.
The door 976 may also support the bar code reader 978 . The bar code reader 978 automatically reads a bar code (not shown) that is provided on the riser tube R. The bar code contains all of the predetermined data regarding the characteristics of the flow restrictor 24 (e.g., its length and diameter) and the characteristics of the riser tube R. This information is passed to the processor 30 which is then used to determine the viscosity.
The batteries B 1 /B 2 may each comprise a 12VDC, 4 amp-hour battery, or any equivalent power supply (e.g., batteries used in conventional lap-top computers such as lithium ion batteries). The display 928 provides the status indicators 972 A/ 972 B for each battery in the MDCBV 920 . In particular, when the MDCBV 920 is operating off of battery B 1 , the two battery indicators 972 A/ 972 B appear on the display 928 . However, once battery B 1 is depleted, the battery B 1 indicator 972 A disappears and the battery B 2 indicator 972 B blinks to warn the operator that the MDCBV 920 is now operating off of the back-up battery B 2 and re-charge of battery B 1 is necessary.
The preferred fluid collector 26 of the present invention is similar to that disclosed in application Ser. No. 09/789,350. In particular, the collector 26 comprises an inner circular wall 35 that divides the collector 26 into a central portion 31 and an annular portion 39 . The central portion 31 collects the blood as it enters the collector 26 . The column of blood 38 falls through the riser tube R, the flow restrictor 24 , the adaptor 34 and then into the central portion 31 . Any overflow spills into the annular portion 39 .
It should be understood that the phrase “column of blood 38” is meant to cover the continuous element of blood that occupies the riser tube R as well as the blood that occupies the flow restrictor 24 and the adaptor 34 .
To minimize any surface tension effects that would normally occur if an open end 36 of the adaptor was positioned above the level of collected blood 300 in the central portion 31 , it is necessary to begin collecting mass vs. time data only when the open end 36 of the adaptor 34 is submerged within the collected blood 300 . This is shown most clearly in FIG. 4 . In order to accomplish this, the open end 36 of the adaptor 34 is placed appropriately below the datum line (e.g., the top edge 37 of the inner wall 35 of the preferred collector 26 ) and the level detector 400 is provided for detecting when the collected blood 300 has reached the datum level. The level detector 400 informs the processor 30 when this event has occurred. Thus, the processor 30 is able to determine those mass vs. time data points where surface tension effects are minimized. The level detector 400 can be implemented in various ways known to those skilled in art, e.g., float sensors, tuning fork sensors, ultrasonic sensors, optical sensors, proximity sensors, capacitance sensors, etc. and all of which generate an electrical signal when a particular fluid level has been reached. An exemplary sensor is the ColeParmer EW-20603-22 Capacitive Level Sensor.
It should be understood that the output side 3 of the flow restrictor 24 can be integrally formed with the input side 5 of the adaptor 34 .
The concept of the blood viscosity determination using the MDCBV 920 is that a portion of the circulating blood of the living being is diverted from the living being using the blood conveyor 926 into the blood receiver 922 to create a column of blood 38 (FIG. 4) in the riser tube R. Next, the column of blood 38 is allowed to fall and collect in the fluid collector 26 over time, whereby the changing mass of this collector 26 is monitored over time. From this mass vs. time data and based on the characteristics of the flow restrictor 24 and the riser tube R, the circulating blood viscosity can be determined. In addition, where the blood exhibits yield stress, τ y a residual amount of the column of blood 38 remains in the riser tube R after a long period of time at the end of the viscosity test run; furthermore, there are surface tension effects that also contribute to this residual amount of the column of blood 38 as a result of the gas-liquid interface 23 (FIG. 4 ). The height of this residual column of fluid is known as Δh ∞ , where Δh=h(t)−datum level and where h(t) represents the height of the column of blood 38 in the riser tube R at any time; the term h ∞ (FIG. 1A) represents the final height of the column of blood 38 in the riser tube R at the end of the test run after a long period of time. As will also be discussed later, the viscosity determination of the blood can be determined using the MDCBV 920 without the need to determine h(t) or the initial position, h i , of the column of blood 38 in the riser tube R at which data is collected.
To obtain accurate data, it is important to “wet” all of the lumens, namely, the riser tube R, the valve mechanism 946 , the flow restrictor 24 and the adaptor 34 before data is taken. As a result, in order to generate the column of blood 38 and then allow it to fall, the valve mechanism 946 must be operated as follows: When the viscosity test run is initiated, the processor 30 activates the valve mechanism 946 by commanding a valve driver 986 (e.g., a 500 mA solenoid, or stepper motor, etc.) which rotates the valve into the position shown in FIG. 5 A. This allows the diverted portion of the circulating blood to flow up into the riser tube R to create the column of blood 38 . When the overflow detector 981 detects a predetermined height, h 0 , of the column of blood 38 , the overflow detector 981 informs the processor 30 which then commands the valve driver 986 to rotate the valve into the position shown in FIG. 5 B. As a result, the column of blood 38 begins to fall through the riser tube R, through the valve mechanism 946 , into the flow restrictor 24 , through the adaptor 34 and into the central portion 31 of the fluid collector 26 . As mentioned earlier, the processor 30 is informed by the level detector 400 when the open end 36 of the adaptor 34 is submerged under the level of the collected blood 300 in order to minimize any surface tension effects. Next, the valve driver 986 is commanded by the processor 30 into the position shown in FIG. 5C which halts all motion of the column of blood 38 . The initial position of the column of blood, h i , is thereby established for viscosity determination purposes, as will be discussed later. Finally, the processor 30 commands the valve driver 986 to rotate the valve into the position shown in FIG. 5 D and the column of blood 38 begins falling while data is collected.
The overflow detector 981 may comprise an optical source 981 A, e.g., a light emitting diode (LED) and a photodetector 981 B for detecting emitted light from the optical source 981 A; once the upper end of the column of blood 38 interrupts the emitted light, the photodetector 981 B informs the processor 30 which operates the valve mechanism 946 , as discussed previously. It should be understood that this implementation of the overflow detector 981 is exemplary only and that it is within the broadest scope of this invention to include all methods of level detection known to those skilled in the art of detecting the level of the column of blood 38 in the riser tube R.
FIG. 6 depicts a second embodiment of the MDCBV 920 wherein the flow restrictor 24 forms the lower end of the riser tube R, rather than being located on the other side of the valve mechanism 946 . As a result, the input side 5 of the adaptor 34 is coupled to the valve mechanism 946 . For proper operation, the datum line needs to be above the input side 7 of the flow restrictor 24 , as shown in FIG. 6 . Other than that, the operation of this variation is governed by the same equations for the first embodiment as will be discussed below.
FIG. 7 depicts a third embodiment of the MDCBV 920 wherein the valve mechanism 946 ′ is positioned at the top of the riser tube R, rather than at the bottom. The advantage of this valve mechanism 946 ′, position is that there is no need to first fill the riser tube R to a predetermined level before proceeding with the test run; instead, in accordance with the valve mechanism 946 ′ operation as shown in FIGS. 8A-8B, the test run proceeds with the processor 30 commanding the valve driver 986 to rotate the valve to the position shown in FIG. 8 A and then the processor 30 stops any more input flow from the blood conveyor 926 as shown in FIG. 8 B. In particular, as used in this embodiment, the blood conveyor 926 is coupled to the valve mechanism 946 ′ at a port 763 ; the top end of the riser tube R is coupled to the valve mechanism 946 ′ at a port 765 . The valve mechanism 946 ′ also includes a vent coupler 762 that couples the top of the riser R to a third port 764 that is exposed to atmospheric pressure; thus when the valve is rotated into the position shown in FIG. 8B, the blood in the riser tube R will flow downwards. Again, it should be emphasized that to minimize any surface tension effects, the level detector 400 informs the processor 30 when the open end of the adaptor 34 is submerged in the collected blood 300 . Other than that, the operation of this variation is governed by the same equations mentioned previously.
MDCBV Theory of Operation
The concept of the blood viscosity determination using the MDCBV 920 is based on the discussion of determining the viscosity of non-Newtonian fluids, such as blood, as discussed in detail in application Ser. No. 09/789,350, whose entire disclosure is incorporated by reference herein. The MDCBV 920 basically comprises a cylinder (i.e., the riser tube R) having a diameter, φ R , into which a portion of the circulating blood of the living being is diverted for viscosity analysis. The bottom of the riser tube R is coupled to the flow restrictor 24 (e.g., a capillary tube), having a diameter φ c and a length L c . It is preferable that the diameter of the adaptor 34 be similar to the diameter of the riser tube R, φ R .
Using this configuration of riser tube R and flow restrictor 24 , once the column of blood 38 is generated (as shown in FIG. 4 ), when the valve mechanism 946 is rotated to the position shown in FIG. 5B, the column of blood 38 is subjected to a decreasing pressure differential that moves the column 38 through a plurality of shear rates (i.e., from a high shear rate at the beginning of the test run to a low shear rate at the end of the test run, as can be clearly seen in the column height change—FIG. 1 A and the mass accumulating in the collector 26 ′—FIG. 1 B), which is especially important in determining the viscosity of non-Newtonian fluids, such as blood. In particular, once the desired height, h i is achieved by the column of blood 38 and with the upper end of the riser tube R exposed to atmospheric pressure, a pressure differential is created between the column of fluid 38 and the outlet 36 of the adaptor 34 . As a result, the column of blood 38 flows down the riser tube R, through the flow restrictor 24 , through the adaptor 34 and into the collector 26 ′. As the column of blood 38 flows through these components, the movement of column of blood 38 causes the pressure differential to decrease, thereby causing the movement of the column of blood 38 to slow down. This movement of the column of blood 38 , initially at a high shear rate and diminishing to a low shear rate, thus covers the plurality of shear rates. However, it should be understood that it is within the broadest scope of this invention to include any other configurations where the column of blood 38 can be subjected to a decreasing pressure differential in order to move the column of blood 38 through a plurality of shear rates.
The rate of flow through the flow restrictor 24 is equal to the rate of change of the mass of the blood 300 collected on the mass detector 28 . Hence, the corresponding flow rate in the flow restrictor 24 can be expressed as: Q ( t ) = 1 ρ m t ( 1 )
where ρ is the density of the blood.
In order to determine the viscosity of the blood, it is necessary to know the pressure drop across the flow restrictor 24 . What is measured using the MDCBV 20 is the total pressure drop between the riser tube R and the flow restrictor 24 including not only the pressure drop across the flow restrictor or capillary tube 24 (ΔP c ) but also the pressure drop occurring at the inlet and outlet (ΔP e ) of the capillary tube 24 . One of the accurate methods for determining (ΔP e ) is to make a Bagley plot (see C. W. Macosko, Rheology: Principles, Measurements, and Applications (VCH, 1993)) with at least two short capillary tubes (not shown) of the same diameter. Hence, the pressure drop occurring at the inlet and at the outlet of the capillary tube 24 has to be subtracted from the total pressure difference (ΔP t ). Considering these pressure drops, the pressure drop across the capillary tube 24 can be described as
ΔP c =ΔP t −ΔP e (2)
It should be noted that the contribution from the second term on the right hand side (ΔP e ) in Eq. (2) is less than 0.5%; hence this term can be neglected for all practical purposes, and as a result, equation 2 reduces to:
Δ P c =ΔP t (3)
An expression, therefore, for the total pressure as well as the pressure across the capillary tube 24 is:
ΔP t =ΔP c =ρg[h i −Δh ( t )− h ∞ ]=ρg[h i −h ∞ −Δh ( t )] (4),
where Δh(t) represents the changing height of the falling column of blood 38 and is given by the following equation: Δ h ( t ) = 4 m ( t ) ρπθ R 2 ( 5 )
and where:
h i is the initial height of the column of blood 38 ;
h ∞ is the final height of the column of blood 38 after a long period of time; and
m(t) is the mass of the collector 26 over time.
In addition, the final mass after a long period of time, m ∞ , can be expressed in terms of the height of the column of blood 38 as follows: m ∞ - m i = ρ ( πθ R 2 4 ) ( h i - h ∞ ) ; ( 6 )
and solving equation 6 for (h i −h ∞ ), ( h i - h ∞ ) = 4 ( m ∞ - m i ) ρπθ R 2 ( 7 )
Thus, making the substitution of equations 5 and 7 into equation 4, Δ P c = ρ g [ 4 ( m ∞ - m i ) ρπθ R 2 - 4 m ( t ) ρπθ R 2 ] = 4 g πθ R 2 [ m ∞ - m i - m ( t ) ] ( 8 )
It is assumed that any surface tension effects are constant with time and throughout the test run, e.g., the surface tension experienced at h i is similar to the surface tension effect experienced at h ∞ .
The significance of equation 8 includes, among other things, that in order to determine the pressure across the capillary tube 24 , only the final mass, m ∞ , the diameter of the riser R and the mass data detected by the mass detector 28 , m(t), need be known; the initial height of the blood column 38 , h i , nor the final height, h ∞ , nor the initial mass, m i , need to be known. Furthermore, equation 8 also represents, in accordance with the assumption that the surface tension is constant, a surface tension-free capillary.
Non-Newtonian Fluids
The shear rate dependent viscosity for a non-Newtonian fluid, such as blood, flowing in the capillary tube 24 is obtained from experimental data with some mathematical treatment, and the necessary equations can be found in any standard handbook (e.g, C. W. Macosko). The shear rate at the capillary tube 24 wall is obtained form the classical Weissenberg-Rabinowitsch equation (see S. L. Kokal, B. Habibi, and B. B. Maini, Novel Capillary Pulse Viscometer for non-Newtonian Fluids, Review of Scientific Instrument, 67(9), pp. 3149-3157 (1996)): γ . w ( t ) = - V z r r = R = 1 4 γ . aw [ 3 + ln Q ln τ w ] ( 9 )
where {dot over (γ)} aw is the apparent or Newtonian shear rate at the wall and where φ c is the diameter of the capillary tube 24 . γ . aw ( t ) = 32 Q ( t ) πφ c 3 ( 10 )
and the shear stress at the wall is given by: τ w ( t ) = Δ P ( t ) φ c 4 L c ( 11 )
Thus, the viscosity corresponding to the wall shear rate is calculated in the form of a generalized Newtonian viscosity: η = τ w γ . w = πφ c 4 Δ P 32 QL c ( 3 + ln Q ln τ w ) - 1
= ρ g φ c 4 8 L c φ R 2 [ m ∞ - m i - m ( t ) ] ( m t ) ( 3 + 1 n ′ ) ( 12 )
where 1 n ′ = ln Q ln τ w .
Thus, Equation 12 represents the viscosity of the blood in terms of the mass measured by the MDCBV 920 .
The viscosity versus shear rate information can be obtained from equations 9-12 by measuring the mass of the collected fluid with respect to the time from which the pressure drop and flow rate can be calculated. The values of R and L c must be obtained by calibration. Since equation (9) is non-linear, the procedure to calculate the shear rate and the corresponding viscosity is not straightforward. One of the approaches to obtain the viscosity from the general equations presented above is to adopt a finite difference technique for differentiation of equation (9). If there is enough data near the point of interest, it is possible to evaluate the derivative as: 1 n ′ = ln Q ln τ w = 1 n ( 13 )
where n is simply the exponent of the power law constitutive equation. Even though the power-law exponent is used in the above equations, this does not limit the capability of the present measurement for power-law fluids. The rigorous approach can still be taken for obtaining a viscosity versus shear rate relationship for any fluid (see S. L. Kokal, B. Habibi, and B. B. Maini, “Novel Capillary Pulse Viscometer for non-Newtonian fluids, Review of Scientific Instrument, 67(9), 3149-3157 (1996)).
In application Ser. No. 09/789,350 there is a figure, namely, FIG. 7, which illustrates the viscosity results using a mass detector viscometer for blood and which shows an excellent agreement with those from a conventional rotating viscometer, e.g., the Physica UDS-200 over a range of shear rates.
As mentioned earlier FIGS. 1A and 1B provide a summary of the height vs. time characteristic, and the mass vs. time characteristic, of the falling column of blood 38 during the viscosity test run. As can be seen in FIG. 8A, the level of the column of blood 38 initially is at h i . During the test run, the column of blood 38 falls and arrives at a final column height of h ∞ after a long period of time (e.g., 2-5 minutes after the column of blood 38 begins to fall). As also mentioned earlier, this final height h ∞ can be attributed to both the surface tension effect of the gas-liquid interface 23 (FIG. 4) as well as any yield stress, τ y , exhibited by the blood. With regard to the change in mass, m(t), as shown in FIG. 8B, the mass climbs quickly and then slows down towards a final mass value, m ∞ after a long period of time. As mentioned earlier, what is important here is that the viscosity of the blood can be determined using the MDCBV 920 without the need to know h i and h ∞ .
FIG. 9 depicts a fourth embodiment of the MDCBV 920 wherein the changing mass of the riser R and flow restrictor 24 are detected, rather than detecting the change in mass of the collected blood 300 in the collector 26 . Thus, rather than obtaining an increasing mass with time, the mass detector 28 detects the decreasing mass of the riser R/flow restrictor 24 assembly with time, as shown in FIG. 10 . The empty weight of the riser R, flow restrictor 24 and a base 29 (upon which the flow restrictor 24 is disposed) are taken into account before the test run is conducted. As a result, the expression for the pressure drop across the capillary tube 24 is: Δ P c = 4 g πφ R 2 [ ( m i - m ∞ ) - m ( t ) ] . ( 14 )
Other than that, the theory of operation of this fourth embodiment of the MDCBV 920 is similar to that discussed above with regard to the other embodiments of the MDCBV 920 .
A column height detection capillary (CHDC) blood viscometer 1020 is discussed next.
The CHDC blood viscometer 1020 utilizes the same structure, for example, the riser tube R and the flow restrictor 24 , but with the mass detector 28 and the overflow detector 981 replaced by column level detector 1056 . As a result, the viscosity of the circulating blood of the living being can be determined using the CHDC viscometer 1020 . In particular, it can be shown that the viscosity of the circulating blood, η, is given by: η = ρ g φ c 4 8 L c φ R 2 ( h i - h ∞ - Δ h ( t ) h ( t ) t ( 3 + 1 n ′ ) )
The column level detector 1056 is similar to the one disclosed in application Ser. No. 09/573,267 whose entire disclosure is incorporated by reference herein. The column level detector 1056 detects the level of the column of blood in the riser tube R and may comprise and LED array 1064 and a CCD 1066 arrangement (FIG. 12 ). To that end, the CHDC blood viscometer 1020 basically comprises the blood receiver 922 and an analyzer/output portion 1024 .
It should be emphasized that it is within the broadest scope of this invention to include all ways known in the art for detecting the level of the column of blood and the present invention is not limited, in any way, to the use of optical detection.
As with the MDCBV 920 , the output side 3 of the flow restrictor 24 can be integrally formed with the input side 5 of the adaptor 34 .
FIG. 12 depicts one embodiment of the CHDC blood viscometer 1020 which operates similarly to the MDCBV 920 except that the level of the column of blood 38 is monitored rather than the changing mass in the collector 26 . In addition, the function of the overflow detector 981 in the MDCBV 920 is accomplished by the column level detector 1056 , thereby informing the processor 30 when to operate the valve mechanism 960 to allow the column of blood 38 to fall. As a result, the CHDC blood viscometer 1020 utilizes height vs. time data, as shown in FIG. 1A, to determine the blood viscosity. FIG. 13 is a functional diagram of the CHDC blood viscometer 1020 that depicts the operation of the CHDC blood viscometer 1020 , including the use of the submerged end 36 of the adaptor 34 and the level detector 400 .
FIG. 14 is a second embodiment of the CHDC blood viscometer 1020 wherein the flow restrictor 24 forms the lower end of the riser tube R, rather than being located on the other side of the valve mechanism 946 . As a result, the input side 5 of the adaptor 34 is coupled to the valve mechanism 946 . For proper operation, the datum line needs to be above the input side 7 of the flow restrictor 24 , as shown in FIG. 14 . Other than that, the operation of this variation is governed by the same equations for the first embodiment of the CHDC blood viscometer 1020 as will be discussed below.
FIG. 15 depicts a third embodiment of the CHDC blood viscometer 1020 wherein the valve mechanism 946 ′ is positioned at the top of the riser tube R, rather than at the bottom. The same discussion that applies to the third embodiment of the MDCBV 920 that was discussed earlier, applies here for the CHDC blood viscometer 1020 .
Without further elaboration, the foregoing will so fully illustrate our invention and others may, by applying current or future knowledge, readily adapt the same for use under various conditions of service. | An apparatus and method for determining the viscosity of the circulating blood of a living being over plural shear rates caused by a decreasing pressure differential by monitoring the changing weight of the blood, or the changing level of a column of blood over time. The apparatus and method utilize a riser, a capillary tube, a collector and a mass detector, such as a precision balance or a load cell, for monitoring the changing weight of a sample of fluid that flows through these components under the influence of the decreasing pressure differential; alternatively, the apparatus and method use a column level detector to monitor the changing level of the column of blood over time. | 6 |
FIELD OF THE INVENTION
The present invention relates to electrical power units for use in sharing and connecting AC alternating current and DC direct current electrical power supplies.
SUMMARY OF THE INVENTION
The Multi-Function Power Control Unit (MFPCU) of this invention is a network of functional blocks housed in a single enclosure to provide DC power to one or more DC loads. It provides control and internal pathways to share or select a variety of power inputs including AC utility power, alternative DC power sources, as well as DC power from external energy storage devices. Additionally, the MFPCU can also feed back AC power from other attached DC sources into the AC input connection to be shared by other AC loads (including other MFPCU's) within the enterprise. The functional blocks are implemented as hard wired electronic circuit boards, as software running on an internal digital processor, or as a combination of both types using state-of-the-art design techniques.
The multi-function power control unit includes the following functional blocks within its enclosure: a digital processor, a low voltage ON/OFF control block, an alternate DC source DC/DC converter, a DC isolation block, and a bi-directional AC/DC power supply with a bi-directional control module, power factor correction means, and an anti-islanding control block. In addition, the MFPCU has connectors for the following: AC input, DC load, external energy storage device, alternate DC power source, external control device, and central data acquisition and control. The AC input is typically designed for single phase 208–277 VAC at 50 or 60 Hz. Alternatively, the AC input can be designed for three phase 208–480 VAC at 50 or 60 Hz.
The multi-function power control unit operates an alternative source of DC direct current, in conjunction with an AC source of power or DC power storage device, in a dynamic manner that allows maximum power generating capability of the alternative source of DC direct current at the specific operating conditions of the moment. It also can deliver power in excess of that required by a DC compatible load to the AC source of power, DC power storage device, or both in a shared manner.
The system includes three major subsystems:
a Bi-directional Microprocessor-Controlled 4.5 kW AC to DC Power Supply;
a Buck/Boost DC-to-DC Converter with dynamic voltage control; and,
a DC-Based Meter Monitoring of the AC I/O, DC I/O, and internal voltages and currents, which is based on a unique Metering and Control Module (MCM).
The aforementioned bi-directional AC/DC power supply of the present invention includes an AC/DC converter that performs three functions based upon signal from Digital Processor, including the following:
1) rectifies AC and provides regulated DC voltage (via DC isolation) when required by the load or Alternate DC source;
2) rectifies AC and provides regulated DC voltage to an external energy storage device; and,
3) inverts DC power from the alternate DC source or external energy storage and sends it back to the AC System.
A power factor correction circuit adjusts the power factor of the unit to a specified value.
Anti-islanding analog and/or digital logic circuits are used to detect loss of connection to utility grid or external synchronization source.
A bi-directional control module includes an analog and/or digital logic device that enables the bi-directional power supply to “invert” DC power. If this module is not installed the unit can only provide the above noted functions “1” and “2” but cannot provide function “3”.
A DC isolation circuit electrically isolates DC output from AC input.
The bi-directional power supply powers a DC Load with High Voltage (250–400 Volts). The Direct Current (DC) load is a device that consumes power, such as a lighting ballast; lamp; solid state lighting, such as a light emitting diode (LED); a DC motor; an AC motor with variable frequency drive (VFD); or an Inverter. The load may feed power backwards for short durations, such as during braking of a motor.
A low voltage ON/OFF control shuts down all output circuits via a low voltage signal or via wireless communication device. However, another variation allows for a variable signal to dynamically control the voltage of the output circuits.
An alternate DC source DC/DC converter converts output of an alternate energy source to a voltage level suitable for the DC load. This converter has the ability to dynamically change the operating characteristics of an alternative energy source to permit optimization of power transfer or for proper interface with an alternative energy source, such as a photovoltaic (PV) device, a wind turbine, a fuel cell, or an engine driven cogeneration device.
In another variation, the converter is used to provide DC power back to the alternative energy source during periods of inactivity. For example, a wind turbine needs to maintain its direction into the wind, and yaw motors operate during periods of low wind before power production is achievable. Another example is the start-up of a fuel cell or cogeneration system, which may require fuel pumps, cooling pumps or other auxiliary equipment to be running before power production is achievable.
An external energy storage device stores DC power for use in supplying power to the DC load and/or alternate energy source, in the event of a loss of AC power, supplementing power to DC load when required, or supplementing power to AC system. Examples include a high voltage battery, a low voltage battery with DC/DC converter, a flow Battery, a flywheel, and a capacitor.
A digital processor monitors and controls power delivery to and from all sources and loads. The digital processor provides an interface for providing data and receiving control signals from the external central data acquisition and control unit. It may provide the following controls:
1) dynamic voltage control and/or current control supplied by an alternate DC Source;
2) an ON/OFF control of all output circuits;
3) an ON/OFF control for the bi-directional AC/DC power Supply;
4) dynamically change output voltage; and
5) dynamically change voltage of the DC link.
The digital processor also supplies the following data, if requested or required by the external central data acquisition and control unit:
1) volts, amps, and/or power delivered/supplied by the bi-directional AC/DC power supply;
2) volts, amps, and/or power delivered/supplied by the alternate DC source;
3) volts, amps, and/or power delivered/supplied by the external energy storage device;
4) volts, amps, and/or power delivered/supplied by the load; and,
5) system status, alarms, operating mode (i.e.: start-up, run, power failure, shutdown, fault, etc.)
The central data acquisition and control unit is used to provide the ability for central control and data collection of multiple power units, via their digital processors. It may be used for enterprise level and/or multi-building control, such as load management of utility feeder servicing multiple buildings.
The performance of the multi-function power control system of this invention for supplying a high efficiency lighting system is as follows: At this time, AC input high efficiency T-8 lighting ballasts operate an overall efficiency of 88%. A high voltage DC ballast is expected to operate at 94% efficiency. The multi-function power control system unit is expected to achieve a throughput efficiency of 96%. Thus, when combined, the overall efficiency can be 90%, which is 2% better than current systems. The main reason for the increase is due to the larger scale AC/DC power supply. This is analogous to central power plants with a distribution system being more efficient than the equivalent sum of multiple smaller scale power plants.
A larger scale system is also proposed. The current design is for a power unit that is sized to meet the requirements of a single phase 277 V lighting circuit (up to 4.5 kW). An upgrade is a three phase unit capable of supplying multiple lighting circuits, via a DC distribution system, and a single interconnection to the AC system. The larger scale system can be from 15 to 250 kW.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention can best be understood in connection with the accompanying drawings. It is noted that the invention is not limited to the precise embodiments shown in drawings, in which:
FIG. 1 is a Block diagram of a multi-function power control unit (MFPCU) of this invention with external attachment blocks.
FIG. 2 is a chart of IV curves for typical solar cells showing maximum power load line.
FIG. 3 is a Block diagram showing main current flow through the MFPCU for an AC Sourced High Efficiency Lighting mode.
FIG. 4 is a Block diagram showing main current flow through the MFPCU for an AC Outage Operation mode.
FIG. 5 is a Block diagram of enterprise with multiple MFPCU's in a Peak Shaving Enterprise AC Wheeling mode.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a block diagram of MFPCU 1 with a network of various functional blocks within and connections to other functional blocks at its periphery. bi-directional AC/DC Power Supply 2 is transformer isolated and has a bridge topology which incorporates MOSFETS or preferably IGBT's (insulated gate bipolar transistors) which permit operation as both a synchronous rectifier for supplying DC as well as an inverter to supply AC at its input from DC sources. bi-directional Control Module 3 controls the operation as to direction, while Power Factor Control Means 4 insures that power factor at the AC input remains essentially at unity. The Anti-Islanding Means 5 detects loss of AC utility power and blocks the feedback of AC power at the connection 15 from DC sources. Power supply 2 is controlled by Digital Processor 6 . Low Voltage ON/OFF control 7 receives signals (such as emergency situations) from external control devices 13 via line 18 to shut down Alternate DC Source DC/DC Converter 9 or DC Isolation block 8 . Alternate DC Sources 14 such as photovoltaic, wind turbines, fuel cells, etc. are connected via line 19 . The connection is shown as bi-directional since the alternate DC sources may require power in some off modes such as for yaw motors for wind turbines or pumps which are required at start-up of fuel cells. DC Load 11 is connected via line 21 which is also shown as bi-directional wherein, on some occasions, DC loads can generate power. One example is a DC motor after shutdown which can act as a generator for a brief period.
Bi-directional line 20 permits sinking and sourcing of power from DC Isolation 8 or DC Load 11 with Alternate DC Source DC/DC Converter 9 .
External energy storage device 10 stores DC power for use in supplying power to the DC load and/or alternate energy source, in the event of a loss of AC power, supplementing power to DC load when required, or supplementing power to AC system. Examples include a high voltage battery, a low voltage battery with DC/DC converter, a flow Battery, a flywheel, and a capacitor. External Energy Device 10 is connected via line 22 . This connection is also bi-directional since a variety of energy storage devices require power during the charging phase. Simple chemical storage batteries such as lead acid or NiMH require periodic charging. Flow batteries require the use of circulation pumps in the charging process, and the motor/generator of a flywheel storage device is used as a motor to “charge” or spin-up the flywheel.
FIG. 1 also shows metering control module (MCM) 23 , which contains various current and voltage sensors sampling the various sources and load points. These are all connected in a metering network, including metering control module 23 , to digital processor 6 . Central Data Acquisition and Control Unit 12 is an enterprise level digital processor which monitors and controls the operation from a central location. Besides soliciting sensor information from all MFPCU's, unit 12 also monitors the loading of the utility feeder line to the enterprise; in this way it can be used to control the .MFPCU's to limit the peak utility power used by adaptively sharing the power available with load requirements thereby reducing peak surcharges.
FIG. 2 shows typical current/voltage curves for solar cells at different levels of incident irradiation (here ranging from 82 to 140 W/cm squared). The load line for maximum power collected is also drawn. The state-of-the-art control for extracting the maximum output from a solar array over varying operating conditions is known as maximum power point tracking or MPPT. This is achieved either by a predictive open-loop or by a closed-loop control system. In the MFPCU of this invention, MPPT is implemented by the buck/boost DC/DC converter of block 9 under control of digital processor 6 . Solar panels used with the current MFPCU generate from 250 to 600 volts. The operating voltage of a lighting load is 380VDC+/−1%. Thus alternate DC source DC/DC converter 9 will maintain this output while the input varies from 250 to 600 VDC; this is done in conjunction with MPPT protocols to maximize power transfer over dynamically changing conditions such as incident radiation and ambient temperature.
FIGS. 3–5 illustrate the main power flows through MFPCU blocks and paths for different modes of operation.
FIG. 3 shows the most typical mode of operation for an MFPCU. It illustrates AC sourced high efficiency lighting wherein load 11 is a fluorescent light load using DC-input ballasts. Utility AC power at 15 feeds into bi-directional AC/DC power supply 2 where it is converted (at unity power factor via power factor correction 4 ) to DC which flows toward DC isolation block 8 (via line 16 ) and onward to DC lighting load 11 . In FIG. 3 , no external storage device or alternate DC source are shown; they may simply not be implemented at this MFPCU, or they may just not be contributing power at this time.
FIG. 4 shows operation during a utility power outage. Power to supply DC load 11 is supplied via line 21 by alternate DC source 14 via line 19 through DC/DC converter 9 and by external storage device 10 via lines 22 and 16 through DC isolation block 8 . Note that bi-directional power supply 2 is not involved in this operation since it is shut down by anti-islanding means 5 .
FIG. 5 shows a multi-MFPCU enterprise operating so as to reduce power demand from utility feeder 43 entering distribution panel 44 . Central data block 12 is sampling demand via line 45 . Via network of bi-directional data lines 17 , it can keep track of the status of each MFPCU. The distribution of utility power to each MFPCU is shown as a single line 46 (for simplicity) although multiple branch lines would probably be used. In this example, DC load 42 has heavy demand from MFPCU 32 .
MFPCU 31 has its load shut down, but its storage device 41 has some capacity. MFPCU 30 is supplying its own load 11 , but its storage device 10 has some capacity, and currently its alternate DC source 14 has capacity in excess of load 11 demand. Central data block 12 is aware of the status of each MFPCU and the impending peak utility demand threshold, therefore a “peak shaving” protocol is automatically entered. The bi-directional power supplies 2 of MFPCU's 30 and 31 are placed in inverter mode to feed back AC derived from DC sources via lines 47 and 48 respectively. This AC is combined with utility AC on branch lines 46 to supply heavy load 42 attached to MFPCU 32 via line 49 . Note that bi-directional power supply 2 in MFPCU 32 remains in rectifier mode. Obviously there are an almost infinite number of similar scenarios that are possible on a second by second basis; this just illustrates a possible snapshot where AC is wheeled within the enterprise from one MFPCU to another.
In the foregoing description, certain terms and visual depictions are used to illustrate the preferred embodiment. However, no unnecessary limitations are to be construed by the terms used or illustrations depicted, beyond what is shown in the prior art, since the terms and illustrations are exemplary only, and are not meant to limit the scope of the present invention.
It is further known that other modifications may be made to the present invention, without departing the scope of the invention, as noted in the appended Claims. | A multiple bi-directional input/output power control system includes a network of functional blocks housed in a single enclosure, providing DC power to one or more DC loads, and providing control and internal pathways, sharing one or more AC and/or DC power inputs. The system feeds back AC power from the DC power source into an AC input connection, and the fed-back AC power is shared by other AC loads. The system operates at least one alternative source of DC in a dynamic manner, allowing maximization of power generating capability at respective specific operating conditions of the moment. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
This is an original non-provisional application claiming benefit of U.S. Provisional Application 60/765,766, filed Feb. 6, 2006, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an automatic retractable ladder that is installed on an access panel hinged on a framing structure that surrounds an opening into the ceiling for access to an attic space. The access panel and the retractable ladder have two positions. In the first position the access panel automatically closes the opening into the ceiling and the retractable ladder is stowed or retracted on top of the access panel, i.e. in the attic. In the second position the access panel automatically uncovers the opening of the ceiling and the retractable ladder automatically deploys or extends to reach the ground. The automatic opening of the access panel and the automatic deploying of the retractable ladder are achieved through gravity, without assistance of a motorized apparatus, after the release of safety latches. The automatic closing of the access panel and the automatic stowing of the retractable ladder are achieved through a single motorized apparatus. The latching of the access panel in its closed position is achieved automatically and mechanically.
2. Description of the Related Art
Ladders for attic access are widely used by the people in their private homes. Attic accesses are usually provided above the garages and/or living quarters of private homes. The most common attic access consists of an access panel, spring loaded in the closed position and hinged on a wooden structure frame surrounding an opening in the ceiling and installed in the ceiling. To get access to the attic, a user would pull on a piece of rope attached to -the panel and hanging therefrom. This opens the panel, giving access to a folded ladder. The ladder is usually composed of three sections that are folded on top of each other and hinged between each other. The first section is attached to the panel. To deploy the ladder, a user needs to manually grasp the folded second and third sections, rotates this assembly to the deployed position and finally grasp the third section to manually unfold it from the second section. Once the unfolding is achieved, the three sections of the ladder are usually extended in alignment enabling a user to access the attic space. The opposite process needs to be followed by the user for the refolding of the ladder. For re-closing the panel, the user needs to push firmly on the panel moving the panel up to a couple of inches from the ceiling. At such point the springs of the panel take over and move the panel to its fully closed position.
The experience shows that the drawbacks of these attic access systems reside in the difficulty of the steps that need to be performed for the opening of the panel, i.e., the unfolding of the ladder, the refolding of the ladder and the re-closing of the panel. While the procedure appears to be easy for a male, provided he is tall, strong and not impaired, the procedure is difficult for a female and virtually impossible as well as potentially dangerous to any elderly person.
U.S. Pat. No. 6,866,118 describes a ladder that can be extended and retracted by an electric motor. While the technology described appears to be an improvement over the manual attic ladders mentioned previously, its complexity makes it impracticable and too costly for industrial or private home applications.
It would consequently be of great advantage to provide a system giving easy and safe attic access to everyone at a low cost.
BRIEF SUMMARY OF THE INVENTION
The present invention overcomes the drawbacks of the prior art by providing a fully automatic access to an attic. More particularly, the invention is composed of an access panel that is hinged towards the forward end of a frame structure that supports sections of ladders. The frame structure supports in its aft end part of the mechanism that unlatches the panel, controls its opening, controls the deployment of the sections of ladders, retracts the ladder and closes the panel and re-latches it on the fixed frame. More particularly, while the invention uses gravity for the opening of the panel and for the extension of the sections of ladders, it uses a single electric motor mounted at the aft end of the framing structure for performing the retraction of the ladders and the closing of the panel. The relatching of the panel and its associated sections of ladders in the stowed position is purely mechanical, i.e., without the assistance of electric energy.
The stow latch performs the function of maintaining the panel and its associated sections of ladders in the closed position.
The safety latch performs the function of controlling the opening of the panel and the extension of the sections of ladders to the ground.
The single electric motor performs two distinct functions. The first function is to retract the sections of ladders to their stowed position after they have been extended to the ground, and the second function is to close the panel.
In one exemplary embodiment of the invention, there is one electric solenoid for controlling the unlatching of the stow latch and one electric solenoid for controlling the unlatching of the safety latch. Both latches are equipped with a manual override. In another embodiment of the invention, the unlatching of both latches is only achieved manually.
It is a characteristic of this invention that the electric motor is only energized to retract the sections of ladders and to close the panel to its stowed position. The electric motor is not energized to either open the panel, or to extend the sections of ladders, or to maintain the panel in its stowed position. The shaft of the electric motor is equipped with a gear that drives a single gear free-wheel. The single gear free-wheel is free to rotate in one direction and is driven by the electric motor in the opposite direction. The single gear free-wheel is mechanically connected to two concentric shafts, the inner shaft being supported by the framing structure while the outer shaft supports one spool on each end thereof. The outer shaft is free to rotate in one direction and is driven by the electric motor in the opposite direction. One end of the cables is rolled up on, and attached to, each of the spools. The other extremity of the cables is attached to the last section of the ladder. In the free direction of rotation of the outer shaft, the spools unroll their dedicated cables allowing the opening of the access panel and subsequently the deployment of the sections of ladders. In the other direction of rotation of the shaft, the spools roll up the cables allowing the retraction of the sections of ladders and lastly the closing of the access panel.
In one embodiment of the invention there is an automatic mechanical locking of the access panel in its fully opened position, once the sections of ladders have departed from their fully retracted position. This is to require the re-stowing of the ladder before the closing of the panel.
In another embodiment of the invention, there is no mechanical locking of the access panel in its fully opened position.
The ladder of the invention is at least composed of two distinct sections that are engaged in a sliding arrangement. Depending of the height of the ceiling, the number of sections can be increased. The figures accompanying the detailed description of the invention show three sections of ladders. The first ladder section is mechanically attached to the access panel, the second ladder section is arranged to slide on top of the first ladder section, and the third ladder section is arranged to slide on top of the second ladder section. Mechanical stops are provided on each of the ladder sections for limiting the sliding stroke.
The invention, in accordance with preferred and exemplary embodiments, together with further objects and advantages thereof, is more particularly described in the following detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an access panel shown in its stowed position;
FIG. 2 is a perspective view of the access panel shown in FIG. 1 with the framing structure removed;
FIG. 3 is a perspective view of the framing structure equipped with a driving mechanism;
FIG. 4 is an enlarged partial perspective view of the rear portion of the framing structure shown in FIG. 3 and the driving mechanism;
FIG. 4 a is an enlarged perspective view of a portion of the apparatus shown in FIG. 4 for unrolling and rolling the cables;
FIG. 4 b is an enlarged partial perspective view of the brake shown in FIG. 4 ;
FIG. 5 is an enlarged perspective view of the stow latch of the apparatus in the latched and stowed position;
FIG. 6 is a side view of the access panel shown in the opened position, with sections of the ladder being retracted, hidden items being shown in dotted lines;
FIG. 7 is a side view of the access panel showing full extension of section 2 and partial extension of section 3 , with the access panel being locked in its opened position;
FIG. 8 shows a perspective view of the access panel in its fully extended position;
FIG. 9 shows perspective view of the first ladder section;
FIG. 10 shows a perspective view of the second ladder section;
FIG. 11 shows a perspective view of the third ladder section; and
FIG. 12 is a partial perspective view of the first ladder section and the cover of the access panel;
FIG. 13 is a partial side view of a different braking system with the ladder section removed and the access panel being closed; and
FIG. 14 is a partial side view of FIG. 13 with the ladder sections removed and the access panel being open.
DETAILED DESCRIPTION OF THE INVENTION
In the following detailed description, reference is made to the accompanying drawings, which form a part hereof and are shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It is understood that other embodiments may be utilized without departing from the spirit or scope of the invention. To avoid detail not necessary to enable those skilled in the art to practice the invention, the description may omit certain information known to those skilled in the art. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims.
With reference to FIG. 1 , the ladder sections 500 , 600 , 700 of access panel 30 are shown in their retracted and stowed position. The ladder sections 500 , 600 , 700 are mounted on a frame structure 10 . With reference to FIG. 2 where the framing structure 10 is removed for clarity, the first ladder section 500 is spaced away from the inner surface 810 of the cover 800 (See FIG. 12 ). Beams 801 are mechanically attached to the cover 800 . In this manner, the climbing of the steps of ladder 500 is not affected by the presence of the cover 800 . In other words, the resting position of the feet of the user of the ladder portions of the access panel 30 remains the same whether the user is on ladder sections 700 , 600 or 500 . This allows each step of the ladder sections to have the same depth, and this provides to the user the same position of steps against his feet regardless of which section of the ladder he is standing on.
There are many manual retractable ladders that are commonly used in the industry, and more particularly in the construction industry. These ladders are composed of different sections that are arranged to slide on one another so that they can be extended and retracted. However the steps of these ladders are usually composed of a plurality of rungs. Such a step configuration would be neither comfortable nor safe for everyone to use. Therefore, as shown on FIGS. 2 , 9 , 6 , 7 , 8 , 9 , 10 , 11 , and 12 , all the steps have a comfortable width for the security of the person climbing of each of the sections.
With reference to FIG. 2 the ladder sections 500 , 600 , 700 are configured to allow a longitudinal sliding motion between each other. Section 500 is mechanically attached to cover 800 and spaced from it by beams 801 . Section 600 is configured to slide longitudinally on top of, but inside, section 500 . Section 700 is configured to slide longitudinally on top of, but outside, section 600 . No further description of the sliding arrangement is made as this is a very well known and used in industrial ladders technology.
Cover 800 that supports the ladder sections 500 , 600 , 700 is hinged via hinge 819 on forward end 13 of the framing structure 10 (See FIGS. 1 and 2 ). Since ladder section 500 is mechanically attached to cover 800 , the hinge 819 can alternatively be installed between ladder section 500 and forward end 13 of framing structure 10 .
Still in reference to FIG. 2 , one end of cables 50 is attached to reels 101 while their other end is attached to bars 703 of ladder section 700 . Cables 50 are guided by pulleys 301 hinged on the framing structure 10 (See FIG. 1 ), the pulleys 303 hinged on cover 800 and pulleys 305 hinged on ladder section 500 . Clevis supports 304 of pulleys 303 are located such that the portion of the cables 50 that is guided by pulleys 301 and 303 is substantially vertical. This decreases the force required for the closing of the cover 800 . Pulleys 305 are supported by clevis fittings 306 that are mechanically attached to either the forward portion of ladder section 500 or the forward portion of the cover 800 . Retainer cables 60 have one end attached to bolts 19 that are mechanically attached to longitudinal sides 11 and 12 of framing support 10 (See FIG. 3 ). The other end of cables 60 is hinged on clevis fitting 802 that is mechanically attached to the cover 800 .
Still in reference to FIG. 2 , the locks 201 have been moved away from their locked position by the rod 704 that is mechanically attached to ladder section 700 . The locks 201 are spring loaded via springs 202 towards their locked position, and their function is to lock the cover 800 to its full opened position when the ladder sections 600 and/or 700 have moved away from their retracted position.
With reference to FIG. 3 , the framing structure 10 that supports the ladder sections 500 , 600 , 700 has a forward end 13 , a intermediate distal end 14 and an aft end 15 . The three ends 13 , 14 , 15 are bordered by two identical longitudinal opposite sides 11 and 12 . There is a central through opening 17 disposed between the forward end 13 and intermediate distal end 14 and the longitudinal sides 11 and 12 . There is no central through opening between intermediate distal end 14 and aft end 15 and the longitudinal sides 11 and 12 ; however, there is a cavity 20 that has a floor 16 . This cavity 20 houses the latching system (as will be subsequently described), the safety system and the driving mechanism 100 of the apparatus of the invention. Still in reference to FIG. 3 , the forward end 13 provides the support for locks 201 , the function of which is described later. The longitudinal sides 11 and 12 support the driving shafts of the braking system 102 , the devices 302 which support pulleys 301 , and the bolts 19 of the retainer cables 60 ( FIG. 2 ). The lower faces of the longitudinal walls 11 and 12 and of the forward end 13 and intermediate distal end 14 are fitted with a seal 18 that is sandwiched by cover 800 when in its closed position. In this manner, should the access panel 30 be installed in a ceiling of a room that has a atmospheric controlled environment, energy spending is minimized.
With reference to FIG. 6 , the cover 800 is shown in its full opened position. Cover 800 cannot open further because it is retained by cables 60 . Pulled by springs 202 , the mechanical locks 201 have started to pivot on mounting devices 203 that are mechanically attached to forward end 13 . One end 205 of the springs 202 is attached to the locks 201 while the other end 206 is attached to rod 503 of ladder section 500 (See FIG. 9 ). In this position the mechanical locks 201 have hot yet reached their latched position because the ladder section 700 has not moved away from its retracted position.
With reference to FIG. 7 , the mechanical locks 201 are pulled by springs 202 and have reached their latched position. The mechanical locks 201 are resting on their abutment fitting 204 that is mechanically attached to the forward end 13 . The mechanical locks 201 are also resting on fittings 501 (See FIG. 9 ). In this position, the cover 800 and the ladder sections 500 , 600 , 700 are locked in the opened position because of the over center arrangement of the mechanical locks 201 . Also in this position, the reaction force that the ladder section 500 communicates to the mechanical locks 201 is to further rotate the mechanical locks 201 towards an even more secure locked position, but this not possible as the abutment fittings 204 prevent the mechanical locks 201 from rotating further.
In reference to FIG. 8 , the ladder sections 600 and 700 are fully extended. Cables 60 prevent further opening of cover 800 . Operation of cables 50 with pulleys 301 , 303 and 305 and reels 101 retract the ladder sections 600 and 700 and close the cover 800 as will be described hereinbelow.
Starting with FIG. 1 , the access panel 30 is retracted and closed or stowed. To initiate the opening of the cover 800 of the access panel 30 , one needs to press a switch in the living area (not shown) for energizing of the solenoid 223 that has its piston rod spring loaded in the retracted position (See FIG. 5 ). This action extends the piston rod of the solenoid 223 which then pivots the unlatching lever 221 of stow latch 225 towards its unlatched position. The unlatch lever 221 disengages stow latch 225 from its latch receptacle 220 mounted on the intermediate distal end 14 of the framing structure 10 , and by gravity the cover 800 moves away from its latched position, but is stopped by the safety latch 211 that engages teeth of latch wheel 210 , which is mechanically attached to one of the reels 101 (See FIG. 4 ). Energizing the solenoid 213 retracts its piston rod which pivots the safety lever 211 around its axis that is supported by clevis fitting 212 . The piston rod of solenoid 213 is spring loaded in the extended position. Therefore, energization of the solenoid 213 must be maintained for the safety latch 211 to disengaged from the teeth of the wheel 210 . The switch (not shown) that energized the solenoid 213 is a not an ON-OFF switch, but a switch that needs to be pressed and maintained pressed by the user to open the cover 800 and lower ladder sections 600 and 700 . This is a safety characteristic of the invention, as the access panel 30 cannot accidentally fully open and fully extend unless the user has decided to do so. For example, this prevents the full opening of the access panel 30 and extension of the ladder sections 600 and 700 , should solenoid 223 be accidentally energized by a child or anyone else or should the stow latch 225 break. In the event of an electrical failure, the stow latch 225 can be manually released by pulling on rope or chain 151 that goes through the floor 16 of the framing structure 10 (See FIGS. 3 , 4 , 5 and 6 ). Safety latch 211 can be manually released by pulling on rope or chain 152 (See FIGS. 4 and 6 ).
Once stow latch 225 is released and safety latch 211 is kept away from engaging the teeth of latch wheel 210 , by gravity only, without energizing motor 109 , the cover 800 and the ladder sections 500 , 600 , 700 keep on opening until the access panel 30 is fully opened to the position shown in FIG. 6 is reached. During this phase of the opening, it is gravity only that unrolls the cables 50 from their reels 101 . Cover 800 has cables 60 to limit the opening of the panel access 30 to a predetermined angle typically ranging between 60 and 70 degrees. Still in reference to FIG. 6 , mechanical locks 201 are pulled by their associated springs 202 that force the mechanical locks 201 to rotate around the pivoting axis of mounting devices 203 attached to forward end 13 of framing structure 10 . The pivoting of mechanical lock 201 is also guided and limited by rods 704 attached to ladder section 700 (See FIGS. 6 and 11 ). In the position shown in FIG. 6 , the mechanical locks 201 have not reached their locked position because they are still resting on rods 704 and are not resting on fittings 501 of ladder section 500 .
Gravity effect on ladder sections 600 and 700 continues to unroll cables 50 from reels 101 until the ladder sections 600 and 700 reach the position shown in FIG. 7 . The stops 603 of ladder section 600 (See FIG. 10 ) rest on step 740 of ladder section 700 , so that when ladder section 700 is extending from the position of FIG. 6 to the position shown in FIG. 7 , ladder section 600 follows in unison with ladder section 700 . In the position of FIG. 7 , the stops 602 of ladder section 600 (See FIG. 10 ) rest on the stops 502 of ladder section 500 (See FIG. 9 ) and, consequently, ladder section 600 has reached its fully extended position. As is also shown in FIG. 7 , the mechanical locks 201 are no longer resting on rods 704 of ladder section 700 as mechanical locks 201 are pulled by associated springs 202 to their fully locked position. Mechanical locks 201 are now resting on fittings 501 of ladder section 500 (See FIG. 9 ) and on abutment fittings 204 . In this position the cover 800 and its associated ladder sections 500 , 600 and 700 are locked open and cannot be closed.
Gravity effect of ladder section 700 continues to unroll cables 50 from their reels 101 until stops 702 reach stops 604 of ladder section 600 (See FIG. 10 ). In this position the ladder sections 500 , 600 and 700 have reached their fully extended position shown in FIG. 8 . In order to slow down the speed of opening of the cover 800 , and the speed of extension of the ladder sections 500 , 600 and 700 , a braking system 102 is installed on one of the reels 101 as will be described hereinbelow.
In reference to FIGS. 4 and 4 b the longitudinal wall 12 of framing structure 10 is equipped with a braking system 102 that slows down the rotational speed of the reels 101 when the reels 101 unroll the cables 50 for the opening of the cover 800 and the extension of the ladder sections 500 , 600 , 700 . The braking system 102 consists of a free wheel 162 whose inner shaft 153 is part of a flange 161 that is mechanically attached to side wall 12 . The free wheel 162 supports a braking disk 163 . The free wheel 162 is mounted such that it is not free to turn when the free wheel 110 is free to turn i.e., when the free wheel 110 is allowing the reels 101 to unroll the cables 50 . In other words the free wheel 162 of the braking system 102 of the reels 101 is mounted in the opposite way compared to the free wheel 110 . The friction force of reel 101 against braking disc 163 is adjusted through nuts 105 (See FIG. 4 ).
As shown in FIGS. 8 and 11 , ladder section 700 is equipped with adjustable legs 730 , fitted with rotating shoes 731 to ensure perfect contact with the ground when the ladder sections are fully extended.
As previously described, the opening of the cover 800 and the extending of the ladder sections 500 , 600 , 700 is only achieved through gravity. The retraction of the ladder sections 500 , 600 , 700 and the closing of the cover 800 is achieved via the assistance of a motor. Starting from the position shown in FIG. 8 , the motor 109 shown in FIGS. 4 and 5 is energized via a switch (not shown) in the living area that closes the circuit of the electrical connections of the motor 109 to an electrical power source (not shown). A mechanical device 150 is connected to the motor 109 . No further description of this is provided as this is very well known in the art. Pinion 108 mounted on the shaft of the motor 109 drives a chain 107 that, is connected to a single gear free wheel 110 . A single gear free wheel 110 is driven by the chain 107 in only one direction of rotation, but is free to rotate in the opposite direction to unroll the cables 50 . The driven rotation of single gear free wheel 110 corresponds to rolling cables 50 on their respective reels 101 . As shown in FIGS. 4 and 4 a one of reels 101 is connected to the single gear free wheel 110 via a plurality of fixed rods 11 1 , while the other reel 101 is connected to single gear free wheel 110 via a plurality of adjustable rods 103 and 104 , the adjustment being carried out through nuts 105 . The single gear free wheel 110 is mechanically attached to a center shaft 106 that is supported by the longitudinal walls 11 and 12 of the framing structure 10 .
The motorized drive of the single gear free wheel 110 in the direction of rolling up the cables 50 on their respective reels 101 continues until the ladder section 700 reaches the position shown in FIG. 7 . At such point, step 740 of ladder section 700 (See FIG. 11 ) meets with stops 603 of ladder section 600 (See FIG. 10 ). Thereafter, further reeling in of cables 50 further retracts ladder section 700 and pulls with it ladder section 600 towards their retracted position. When ladder section 700 approaches its fully retracted position, its rods 704 meet with locks 201 and drives locks 201 towards the unlatched position. At such point as the position shown in FIG. 6 is reached, the ladder sections 500 , 600 , 700 are fully retracted, but the cover 800 is unlatched and ready to be closed by the further rolling up of the cables 50 on their reels 101 to reach the closed position. When the cover 800 is approaching the closed position, stow latch 225 , via spring 224 , meets its latch receptacle 220 (See FIG. 5 ) forcing stow latch 225 to re-latch. During the complete rolling up sequence of the cables 50 , the teeth of the latch wheel 210 rotate the safety latch 211 away from its latching position (See FIG. 4 ). Once the access panel 30 is fully re-latched, it is in the configuration shown on FIGS. 1 and 2 and the electric motor is automatically de-energized, via known means such as electrical load currents for example.
During the complete retraction of the ladder sections 500 , 600 , 700 and the closing of the cover 800 , the braking system 102 offers no resistance as it is free to rotate in the direction of rolling up the cables 50 .
In reference to FIGS. 9 , 10 , and 11 ladder sections 500 , 600 , 700 are respectively fitted with a series of steps 520 , 620 , 720 that provides comfort and safety to the user. For instance the steps 520 , 620 , 720 may be covered with a non slippery surface. In addition for ease of climbing, ladder sections 500 , 600 are respectively fitted with railing 505 , 605 (See FIGS. 9 and 10 ).
The invention uses only the motor 109 to retract the ladder sections 500 , 600 , 700 and close the cover 800 . Only gravity is used to open the cover 800 of access panel 30 and extend the ladder sections 500 , 600 , 700 as previously described.
FIG. 13 shows the cover 800 on which the ladder sections 500 , 600 , 700 (not shown for clarity) are mechanically attached and in their stored position adjacent longitudinal side 1 l. Longitudinal side 11 is equipped with at least one off center pivoting cam 1010 on axis 1020 and a fixed cam 1000 . Pivoting cam 1010 can either take the off center position shown in FIG. 13 , or the off center position shown on FIG. 14 . The cable 50 , through the weight of the cover 800 and ladder sections 500 , 600 , 700 , produces counter clockwise pivoting motion MI that forces off center pivoting cam 1010 to stay in its position shown in FIG. 13 . Cable 50 is free, i.e., not squeezed between off center pivoting cam 1010 and fixed cam 1000 .
In FIG. 14 , the ladder sections 500 , 600 , 700 have started their deployment and cable 50 , through gravity, produces clockwise pivoting motion M 2 to the off center pivoting cam 1010 which makes it rotate around axis 1020 and, consequently, applies a braking pressure force to said cable 50 against the fixed cam 1000 . Gravity feed is consequently slowed down by the braking pressure force on cable 50 between off center pivoting cam 1010 and fixed cam 1020 .
This arrangement shown and described in connection with FIGS. 13 and 14 has the benefit to easily control the speed of opening of the ladder sections 500 , 600 and 700 and their fall to the ground. It can be used as a stand alone, or in combination with the devices that control the lowering down of the ladder to the ground. | An access panel is shown in the present invention to provide easy and safe access to an attic space or elevated structure. The access panel is fully automatic. During opening, the access panel only uses gravitational forces for opening a cover. Only during closing is the access panel motorized. The gravitational forces are used to both open the cover and extend the ladder sections, while the motor is only used to retract the latter sections and close the cover. A stow latch keeps the cover closed during non-use. A safety switch keeps the access panel from accidentally opening and the ladder sections from lowering if the stow latch is released. A mechanical lock keeps the cover open when the ladder sections have been lowered. | 4 |
This is a continuation-in-part application of pending prior application Ser. No. 351,589, now U.S. Pat. No. 4,393,728 filed Feb. 23, 1982, which is a continuation of application Ser. No. 129,202, filed Mar. 11, 1980, now abandoned.
FIELD OF THE INVENTION
The present invention refers to a flexible arm, particularly a robot arm, for supporting and/or manipulating tools or the like, said arm comprising a number of elements arranged in a series for contacting each other and power-generating and/or power-transmitting actuating means arranged to operate between or on the elements or a group of elements respectively.
DESCRIPTION OF THE PRIOR ART
Industrial robots are known in a number of different embodiments and they usually consist of a machine, which without manual supervision or control can change the position of an object or a tool in a three dimensional space to a number of alternative points. The main portion of the industrial robot is its robot arm with its associated motion generating control system and program equipment, which can be a mini-computer for example. Advanced robots have a robot arm with up to six degrees of freedom, i.e. a possibility to move in six different planes, for example motion forwards, backwards, upwards, downwards, rotation to the left and rotation to the right. Since the invention refers to an improvement in the robot arm, the control systems and program equipment will not be further described since they can consist of previously known units.
Conventional robot arms are built up from a number of elements and joints, which besides the tool and the load also must support the equipment for the motion and power generation for the separate elements. This equipment usually comprises pneumatic or hydraulic cylinders, electric motors etc., which means that the elements and the joints have to be relatively coarse or heavy, in order to be able to support the equipment. Thus the robot will have a bulky shape and comparatively large external dimensions, which will reduce the flexibility of the robot arm. The pattern of motion and the working ranges of most existing robot arms are otherwise limited and despite all degrees of freedom mainly comprise only a plane circular working field. Another limitation of conventional robot arms is that they cannot be entered into curved or angled spaces or perform manipulations on the side of an object turned away from the robot. Another drawback is that the manufacturing costs are very high.
There have also been developed robot arms with higher flexibility, where the relative motion between each element is achieved via a flexible shaft or a ball joint. Such structural members require high accuracy during manufacture and also careful maintenance. They have limited mobility and their load carrying capacity is entirely dependent on the dimensions of the joint member. Ball or shaft joints are furthermore sliding bearings which are exposed to rather high wear if a continuous lubrication cannot be guaranteed. They are furthermore sensitive to dust particles which can penetrate between the bearing surfaces. For this reason the elements have to be carefully encased, which will impair their accessability, maintenance and particularly a satisfactory lubrication. Owing to the very high demands for accuracy the manufacturing costs are very high.
A condition for achieving the desired flexibility without reducing the load carrying capacity of the arm is that the actuating means, i.e. the wires interconnecting the separate elements, are prestressed so that the surface contact between the elements is strong. Considering the desired flexibility the elements contacting each other have hitherto been designed as ball or shaft joints. These joint members have a radius of curvature equal to the height of half the joint member, whereby the problem will arise that the elements do not have a clearly established position for a certain length of the wire that has been taken in. A robot arm according to this embodiment has therefore a good stability only in the plane of curvature of the arm, while its rigidity in a plane perpendicular to the plane of curvature is poor.
Another problem with wire operated robot arms is that they in certain cases also have a poor torsion resistance, which is determined by the shape of the joint member, (i.e. type of contact zone between the elements), and which prevents the elements from being rotated perpendicular to their rolling plane.
BRIEF SUMMARY OF THE INVENTION
The purpose of the present invention is to provide a robot arm having a very broad working range and a maximum motion pattern, whereby is meant that it will reach almost all points inside a spherical working field. Another purpose is to provide a robot arm, which can be bent so that it can reach the same point by way of a great number of curvature combinations and thereby provide a very high accessability, which means that it can even pass obstacles of different kinds or bend itself around an object. A further purpose is to provide an arm with a very high rigidity in the element plane of curvature and a high torsion resistance and which is cheaper to manufacture as compared to conventional industrial robots. This has according to the invention been achieved by each element having single or double-curved segments or flat surfaces, and combinations of flat and/or curved surfaces, the curved contact surfaces of said segments each being located to contact a contact surface of the adjacent segment, the elements being arranged to perform a rolling motion in relation to each other when actuated by said power-generating and/or power-transmitting actuating means.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described with reference to the attached drawings wherein,
FIG. 1 is a schematic perspective view of a basic embodiment of the arm according to the invention,
FIG. 2 shows the arm according to FIG. 1 in a bent position,
FIG. 3 is a schematic side view of a robot arm according to the invention composed of two groups of elements and thereby being bendable in two different planes or directions,
FIG. 4 is an elevational, partly perspective and partly sectional view of a complete industrial robot provided with a flexible arm according to the invention,
FIG. 5 is a perspective view showing the capability of the robot arm of the invention in reaching around corners etc.,
FIG. 6 is an elevation view on a larger scale of a part of the arm according to one embodiment of the invention and the geometry of the elements forming part thereof,
FIG. 7 is a perspective view of a lamella shaped element according to another embodiment of the invention,
FIG. 8 is a cross-sectional view taken along line VIII--VIII in FIG. 7,
FIG. 9 is an elevational view partly in section of an embodiment which can also perform rotational movements,
FIGS. 10 and 11 are cross-sectional views through two additional embodiments, showing elements actuated electromagnetically,
FIGS. 12, 13 and 14 are cross-sectional views showing further embodiments with hydraulic or pneumatic actuation of the elements,
FIGS. 15 and 16 are cross-sectional views through further embodiments of the invention showing combinations of curved and flat contacting surfaces on the elements,
FIG. 17 is a cross-sectional view through another embodiment having contacting convex surfaces of different radii, and
FIG. 18 is a cross-sectional view of a further embodiment wherein one contacting surface is convex and the other is concave.
DETAILED DESCRIPTION
The flexible arm 10 according to the invention, hereinafter called the robot arm, fundamentally comprises as shown in the embodiment of FIGS. 1 and 2, a number of elements 11 arranged in series and each being designed as a circular disc with curved contact surfaces. Depending on the extent of bending motions the arm shall be able to perform, each element 11 is provided with a number of holes 12 e.g. four holes placed close to the outer edge of the element and on equal distance from each other and from the center of the element, said holes being intended for an equal number of actuating means 14. A through-opening 13 is arranged in the center of the element. The elements are arranged in abutting contact with each other with the guiding holes 12 being located in substantial alignment.
In the top element the guiding holes 12 are counter-sunk, said counter-sinks receiving termination members 15 arranged at the outer ends of the actuating means. The actuating means 14 consist of cables, wires or the like having good tensile strength. By pulling one or more of the wires 14 projecting outside the last element the robot arm can be bent in all directions. If a bending movement is desired between two actuating means 14, as shown in FIG. 2, these are both subjected to a pull, whereby the bending movement can be more or less displaced toward the first or second means 14 by altering the magnitudes of the pulls. The arm 10 can thereby also be brought to perform a rotational movement about its longitudinal axis.
A flexible transmission means 16 passes through the central openings 13 in the elements, said transmission means being intended to transmit tensile--compressive--and/or rotational forces to a tool 23 (FIG. 4) or the like arranged at the free end of the arm.
As can be seen from FIG. 3 the elements can be kept together in groups, where each group is operated with actuating means 14 special for this group. The arm according to FIG. 3 comprises two groups, a lower group A and an upper group B. The elements 11a of the group A are operated by the actuating means 14a, while the elements 11b of the group B are operated by the actuating means 14b. In order to achieve the double-curve shown in FIG. 3 of the arm in one plane, two diametrically opposed actuating members 14a and 14b are actuated as shown with arrows. The two groups A and B of the arm can also perform bendings in different planes by appropriate actuation of the means 14a and 14b. The arm can of course also be provided with more than two groups of elements, so that it can even be bent 360° or more in different planes or directions if desired.
In FIG. 4 is shown a practical application of the arm according to the previous embodiment. The flexible arm 10 composed by two groups of elements 11a and 11b is connected at one end to a machine unit 17, which contains four servo-motors 18, which drive a winding drum 19 for each actuating means 14a and 14b. The motors 18 are reversible and controlled so that each actuating means--each wire--14a and 14b can be subjected to an individually adjustable force during the winding on as well as during the unwinding from the winding drum 19. Resilient prestressing means 31 (FIG. 6) are arranged for the wires 14.
The flexible transmission means 16 is at the lower end of the arm connected to a servo-motor 20 by way of a gear device 21 and an overload protective coupling 22. A tool 23 is connected to the central transmission means 16 at the free end of the arm, said tool comprising a spray gun fed through a tube 24 from a spray painting device 25.
For certain applications it is also possible to transport the work medium to the tool 23 through the central openings of the elements in parallel with the transmission means 16.
The separate elements 11 are enclosed in a protective flexible casing 26.
The flexibility, working range and accessability of the robot arm is illustrated in FIG. 5, which shows that the arm can be bent in such a way that it can even perform manipulations behind obstacles or in spaces otherwise difficult to reach.
In the embodiment according to FIGS. 7 and 8 each element 11' comprises two segment-shaped members 8' and 9' between which a spacing disc 6 is arranged. The segments 8' and 9' have each a single curved contact surface 5' and a plane base surface 7, with which the segments abut against a side each of the spacing disc 6. The segments 8' and 9' can either be attached to the spacing disc 6 or they can be formed intergral therewith. The segments 8' and 9' are arranged in mutually orthogonal planes, which means that every other segment can perform a bending movement in one plane and every other segment a corresponding bending movement in a plane perpendicular to the first mentioned plane. In order to obtain stable positions independent of the bending positions for the separate segments 8' and 9' and without being dependent on a good or poor friction between the contact surfaces, these can be provided with steering means 4, for example teeth cooperating with corresponding teeth in the adjacent element 11' at the relative movement of the segments. The segments 8' and 9' are preferably formed as portions of cylindrical toothed wheels, at which the center of curvature of the single curved contact surface 5 or the center of the pitch circle of the teeth are located outside each element respectively.
Flat segment portions 3 are arranged beside the teeth provided segments 8' and 9' on level with the root of the tooth.
By making the segments 8' and 9' as part cylindrical toothed wheels, in each element 11' arranged in mutually perpendicular planes, an alternating deflection possibility is achieved at each teeth engagement. The deflection angles are superposed and the arm is totally seen given the same possibilities to move as if the contact surfaces had been flat. This design also guarantees that a very good torsional rigidity is achieved since the elements owing to their shape can perform movements only in certain directions. Because of the tooth flange contact there will always be linear contact between two cooperating segments. The large tooth width and/or the flat segment portions 3 give a large contact surface, which in turn results in greater freedom of choice of materials for the segments. Instead of having to use hardened contact surfaces the new device permits the use of appropriate plastic, aluminum, or similar materials.
In previously known all round-flexible robot arms with a joint between each two elements the radius of the joint member r is equal to half the height h of the element, i.e. r=1/2h. This means that such elements do not have a certain definite position for a certain length of the wound up wire, and a robot arm comprising such elements therefore has not the required rigidity.
In order for an arm which comprises a great number of elements to be rigid it is required that a relative change of the position of the elements when bending the arm involves a change of the energy stored in the system. The higher this work is the more stable the arm will be.
This has according to the invention (see FIG. 6) been achieved by the fact that the radius r of each segment 8 and 9 is larger, preferably even much larger than the height h of the segment. In that way the sum of the wire lengths 1 and 2 for each arbitrary torsional angle of the elements 11 will never be equal and this difference Δ represents a change of energy of the arm system. Since the sum of the wire length 14', 14" wound up and wound out is constant, since the wire is wound on a common drum 19, Δ will be identical with the movement of the wire drum. This movement together with the spring force is an important energy addition for achieving the desired rigidity.
The modification shown in FIG. 9 is developed for making it possible also to transfer rotational movements by way of the elements, which for this purpose are provided with radial teeth 35 on the curved surfaces facing each other, said teeth engaging each other independent of which angular positions the elements take. In order to permit the rotational movement of the elements its flanges 30 with openings 12 for the wires 14 are rotatable relative to the element member, which has been achieved by arranging a bearing 36 between these parts. By means of a motor 20 the elements can in this way transfer rotational movements to the free end of the arm and to the tool 23 without in any way impairing the flexibility of the arm.
For transferring great loads and/or moments it is preferred to supplement the wire cable-shaped actuating means 14, which only have a connecting function, with electromagnetic or hydraulic servo-motors.
The embodiment according to FIG. 10 shows a modification with electromagnetic adjustment of the angular position of the elements relative to each other, whereby between each flange 30 are pivotally mounted electromagnets 39, which are arranged to adjust the distance between the elements. Each electromagnet can possibly be individually actuated for providing the highest possible moveability and flexibility.
Instead of arranging moveable iron cores in a coil, as the embodiment shown in FIG. 10, it is possible to use non-moveable electromagnets oriented axially in the elements as shown in FIG. 11. Each non-moveable electromagnet 40 has its poles facing each other and in order to achiefe a variable bending of the arm several such bar shaped magnets can be arranged in a radial pattern in the elements.
In both embodiments according to FIGS. 10 and 11 electric supply cables to the electromagnets are denoted by 41.
Electromagnetic actuating means usually work only between two fixed end positions, whereby a stepless adjustment of the bending of the arm is impossible. This limitation is eliminated with the embodiment shown in FIG. 12, where the actuating means comprises hydraulic or pneumatic servo-motors in the form of cylinders 42 with double opposed pistons 43. The pressure medium can be supplied from a feed tube 45 (not shown) through a central inlet or outlet 44. The pistons 43 are pivotally mounted at the peripheral flange 30 of the elements. The feed tube 45 is preferably passed through apertures (not shown) in the flange 30.
In FIG. 13 is shown an embodiment wherein the elements 11"" are divided into two parts along peripheral flanges and where each part 37 and 38 is provided with a peripheral flange 30'. Servomotors 32 are arranged between these two parts 37 and 38 in such a way that the two parts can be moved into different relative inclined positions. The servomotors 32 consist of shortstroke hydraulic or pneumatic motors, for example piston cylinder devices or bellows actuated by a pressure medium. At least three such motors are arranged at equal distances from each other and conduits 45 cupply them with pressure medium.
A further embodiment where the elements are actuated by hydraulic or pneumatic means is shown in FIG. 14. A number of pressure tubes 46 with radially projecting pressure lips 47 are arranged to operate between peripheral flanges 30" of the elements. When a pressure is supplied in the tube 46 the pressure lips 47 will expand and displace the flanges 30" of the elements from each other. The tubes 46 can be an integral portion of the casing 26 of the arm 10 shown in FIG. 4.
FIGS. 15, 16, 17 and 18 show further embodiments of the invention wherein the elements have different curved surface configurations or cooperate with additional members having a plane surface, or surfaces. In these figures the elements are shown only schematically to illustrate only the cross-sectional configuration of the elements, such as in FIGS. 10, 11 and 12, but it is to be understood that these embodiments are intended to be used in the same manner as the previously described embodiments and although holes comparable to 12 and 13, or actuating means 14, 20, 32, 39, 40, 41, 45, 46, etc., and cooperating structural members are not shown, these further embodiments may be provided with these other features of the invention in accordance with the specific actuators, or combinations thereof, desired.
In FIG. 15 is shown the embodiment wherein a disc 50 having plane or flat surfaces 52 on opposite sides is interposed between adjacent elements 51 so that the curved surfaces of elements 51 have rolling contact on the plane surfaces. Of course, the adjacent members 50, 51 can be regarded as the elements of a robot arm wherein the adjacent elements have curved and flat surfaces respectively in rolling engagement with each other. This design provides a higher rigidity in use than the embodiments utilizing elements having oppositely curved convex contacting surfaces.
FIG. 16 shows the embodiment similar to FIG. 15 but wherein the elements 51' each have one convex curved surface 53 and one plane or flat surface 54 on opposite sides thereof. The curved surface of each element engages the flat surface of the adjacent element.
In FIG. 17 is shown the embodiment wherein adjacent elements 55, 56 have contacting convex surfaces 57, 58 having different radii (see r in FIG. 6) of curvature to provide a different degree of flexibility.
FIG. 18 shows an embodiment wherein adjacent elements 59, 60 have convex and concave contacting surfaces, 61 and 62 respectively, for greater rigidity.
It is to be understood that the above configurations of cooperating contact surfaces for the elements can be used in any combination to produce the flexibility, strength, and rigidity desired for a robot arm. | A flexible arm particularly a robot arm comprising a plurality of elements arranged in a series with adjacent elements in abutting relationship, said elements being interconnected via cables and if desired a power transferring actuating device. The arm has very good rigidity in the bending plane of each element and high torsional resistance together with low manufacturing costs. Each element is designed with opposed single or double-curved segments, or flat surfaces, or combinations thereof with the curved surfaces of each segment engaging the curved or flat surfaces of the adjacent segments, whereby the elements when actuated by the power transferring device have a rolling motion relative to each other. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to magnetic bubble domain memory systems.
2. Description of the Prior Art
In the field of electronic computers and other data processing devices, the performance of such systems is largely limited by the speed, capacity and reliability of the memory system. Various types of memory systems are known and have been used in the art, such as disc files, magnetic tapes, and ferrite cores. Recently, significant interest has been directed toward a different type of memory wherein data is stored in the form of magnetic "bubbles" moving in thin films of magnetic material. The bubbles are actually cylindrical magnetic domains whose polarization is opposite to that of the thin magnetic film in which they are embedded. The bubbles are stable over a consideralble range of conditions and can be moved from one point to another at high velocity. Interest in these devices, in large part, is based on the high packing density that can be achieved and the ability of the cylindrical domain to be independent of the boundary of the magnetic material in the plane in which it is formed. Such devices are described in an article by Andrew H. Bobeck and H. E. D. Scoville entitld "Magnetic Bubbles," Scientific American, June 1971, Vol. 224, pp. 88-90. This article describes several structures for manipulating and controlling transmission of magnetic bubbles along discrete paths and includes an explanantion of one form of a magnetic bubble domain memory.
Magnetic bubble domain memory systems offer significant advantages over conventional memory systems since logic, memory, counting, and switching can all be performed within a single layer of solid magnetic material. This is in contrast to conventional memory systems in which, to perform the above functions, information must move from one devie to another through interconnecting conductors and high gain amplifiers.
In order to carry out the memory functions of a bubble memory system such as logic operations, reading, writing, et cetera, it is necessary to provide an in-plane rotating field at the surface of the bubble memory chips employed in the memory system and to drive electrical current through appropriate leads on the magnetic bubble domain chip at precisely timed intervals relative to the in-plane rotating field. These currents control the magnetic bubble domains in such a way as to allow the user to write data into or read data from any desired location on the memory chip.
Typically, the cntrol signals for synchronizing the memory operations are generated by one-shot multivibrators which depend on RC discharge circuits to produce pulses of desired width and at desired intervals during each rotation of the in-plane rotating magnetic field. Various problems, however, have been encountered in utilizing multivibrators for generating these control signals.
To overcome the problems and difficulties associated with the analog control obtainable with multivibrators, Naden in U.S. Pat. No. 3,997,877, issued Dec. 14, 1976, describes a digital control system employing a read-only memory (ROM) driven by a clock-controlled counter. The counter sequentially advances through its states, providing thereby a sequence of addresses to the ROM, and the ROM contents are arranged so that each output bit develops a specified control signal, as required for the memory system.
The substantial efforts in bubble memory art have, heretofore, been directed to improving bubble chip organization and manufacturing techniques. But still, memories having a very large capacity cannot reliably be manufactured.
It is an object of this invention, therefore, to combine bubble memory chips and to form memory systems which can be constructed to any desired capacity.
It is a further object of this invention to efficiently combine a number of bubble memories with their associated controls on a single construction unit, such as a pluggable card.
It is a still further object of this invention to form a bubble memory system on a card which, with respect to the required control signals, is indistinguishable from any other serial memory system (such as a shift register).
It is an additional object of this invention to form a bubble memory system which is digitally controlled.
It is a still additional object of this invention to form a memory system which gracefully degradates with the occurrence of a low voltage source condition.
SUMMARY OF THE INVENTION
The above and other objects of the invention are achieved with a memory organization system which interconnects, in parallel, a plurality of bubble memory chips. Each of the chips may separately be accessed for writing or reading purposes, while common control is obtained through digitally generated control signals. Low voltage protection is provided by appropriately turning off the in-plane rotating field when the power source exhibits a low voltage condition, protecting thereby the stored data.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic block diagram of a bubble memory system embodying the principles of this invention;
FIG. 2 is a diagram of the physical arrangement of paths in the bubble chip used in the illustrative embodiment of FIG. 1;
FIG. 3 is a polar coordinate diagram describing the permissible areas in which the in-plane field currents of the FIG. 2 chip can occupy;
FIG. 4 depicts the field currents and driving voltages required for generating the rotating magnetic field of the bubble chips of FIG. 2;
FIG. 5 illustrates the control signals required in the memory system of FIG. 1;
FIG. 6 depicts the digital control circuit of element 10 in the memory system of FIG. 1; and
FIG. 7 depicts the analog control circuits of element 10 in the memory system of FIG. 1.
DETAILED DESCRIPTION
In the illustrative embodiment of FIG. 1, elements 20, 30, 40, and 50 are bubble memory chips forming memory block 70 of the system mounted on pluggable card 500. Each bubble memory chip in block 70 has a data input terminal, a data output terminal, and a write/read enable terminal. Block 70 also has four chip select terminals, a clear terminal, and two rotating field terminals which are common to, or affect all of the bubble memory chips in the block.
The memory system of FIG. 1 is arranged to form a serial memory having a total capacity equal to the sum of the chips'to capacities but with an access time equal to the access time of each individual memory chip. This arrangement is achieved by applying input data in parallel, via line 24, to chips 20 through 50, by writing data into or reading data from particular chips with the aid of selection signals 26, 27, 28, and 29 applied to the chip enable terminals, and by "collector OR" combining of the output data to provide a single output data stream on bus 61. The phrase "collector OR" refers to a physical connection of output ports for developing the equivalent of the Boolean OR function. The bubble memory chips are controlled as a group (enabled) for purposes of reading and writing via line 21 and are cleared via line 23. The two field control signals are applied to block 70 via leads 19 and 25.
Other than output bus line 61, all block 70 signals interface with element 10 which controls the operations of memory block 70. Element 10 is responsive to register select input signals on lines 14 and 15--selecting particular chips in block 70; a "clear" command signal on line 13--clearing the memory in block 70; a "store enable" command signal on line 12--enabling the memory in block 70; a clock signal on line 11--synchronizing the various operations of the FIG. 1 system; read and write enable signals on lines 16 and 17, respectively; and an input data source on line 18.
FIG. 2 depicts the spatial organization of the bubble memory chips employed in the illustrative embodiment of FIG. 1. Terminals G+ and G- form the input port of the chip. In response to a current sent through the input port, bubbles are generated at a point designated by the letter G and, once generated, the bubbles propagate along path 71. Terminals R+ and R- form the read/write port of the chip. In response to a current sent through the read/write port, generated bubbles are caused to divert their path at point W onto path 72, from which they enter the main loop of the chip at point M. The number of bits (individual bubbles) stored between points W and M is 60, while the number of bits stored between points G and W (along path 71) is 8.
When a write command occurs and a generated bubble is diverted at point W onto path 72, a corresponding bubble must be erased in the main storage loop of the chip so that the newly generated bubble can assume its rightful place in the queue of bubbles along the main storage loop. This is accomplished at point R in FIG. 2, where propagating bubbles are blocked in response to a write command, and effectively erased from the loop. The number of bits stored between points R and M is 60; exactly the same as the number of bits stored between points W and M.
Location R is also used for reading of data. By applying an appropriate current to terminals R+ and R-, bubbles appearing at point R are replicated; that is, are split in two, with one bubble proceeding toward point M while the other bubble being diverted and proceeding toward detector area D. Bubbles detected in area D appear as voltage pulses across terminals D+ and D-. Terminals D+ and D- form the output port of the chip.
As indicated previously, to propagate bits of data (bubbles) along the memory paths of bubble memory chips, a rotating magnetic field is necessary. The rotating field is generated by attaching two field-generating coils (an inner coil and an outer coil) to the chips, orthogonally to each other, and by driving appropriate currents through the coils.
FIG. 3 is a polar plot of the normalized coil currents required for generating the rotating magnetic field of the bubble memory chips of FIG. 2. The outer coil current is shown in FIG. 3 as a phasor 31 which varies in amplitude along the x axis, and the inner coil current is shown as a phasor 32 which varies in amplitude along the y axis. The magnetic fields developed by the two coils combine to form a single field which relates to the phasor sum of phasors 31 and 32; to wit, phasor 39.
In addition to depicting the coil currents, FIG. 3 depicts the permissible regions of current phasor sum (phasor 39). Shaded annular region 33 is the region within which the phasor sum must rotate, preferably along dotted path 37. The width of the annular region corresponds to the permissible amplitude perturbations of the currents.
When both field currents (phasors 31 and 32) are zero, phasor 39 is located at center 35. Region 34 is the area within which phasor 39 may travel from center 35 to region 33. Region 34 is a sector of approximately 90 degrees, centered about the positive x axis.
FIG. 4 is a time diagram depicting the current (waveforms 41 and 42) required to be developed to cause the phasor sum to traverse along path 37, and the associated driving voltages (waveforms 43 and 44) which must be generated and applied to the coils. FIG. 4 also depicts the current and voltage waveforms for start-up and shut-down conditions.
The requirement for sinusoidal current waveforms may best be realized when it is observed that, as phasor 39 rotates along circular path 37, the projection of that rotation on the x and y axes relates to the cosine and sine functions, respectively. Accordingly, the outer coil current 41, and the inner coil current 42 must be sinusoids and must be 90 degrees apart. Since the currents flow through inductors (field coils), the driving voltages which develop currents 41 and 42, i.e., waveforms 43 and 44, respectively, are, of course, the derivatives of the current waveforms and are also sinusoids.
During start-up and shut-down, the current and voltage requirements are a bit different.
From FIG. 3 it may be observed that one way to reach path 37 from center 35 is to move along the x axis from center 35 to point 36 (located on both path 37 and the x axis). This is accomplished, as shown in FIG. 4, by holding current 42 (phasor 32) at zero while increasing, within interval t 1 -t 2 , current 41 (phasor 31) to a maximum. Once point 36 is reached, currents 41 and 42 are caused to vary sinusoidally, as discussed above, with current 42 lagging current 41 by 90 degrees.
To effect a shut-down, again the x axis within region 34 is employed. This is accomplised by detecting the instant when phasor 39 reaches point 36 and by then reducing the x axis current to zero while holding the y axis current at zero. In FIG. 4, this is illustrated by current 42 being held at zero and current 41 decaying to zero, beginning at time t 3 . To achieve such a shut-down, voltages 43 and 44 are both set to zero at time t 3 .
FIG. 5 depicts the control voltage waveforms required of the bubble memory chip of FIG. 2, as referenced to current waveforms 41 and 42. The period of sinusoidal current waveform 41 was chosen, for the illustrative purposes of this disclosure to, be 20 μsec.
Waveform 45 is the "generate" current. It comprises current pulses of 0.5 μsec duration, located 2.5 μsec from 0 degrees. The "generate" pulses are approximately 285 mA in strenght. Waveform 46 is the "replicate" current. It occurs 0.5 μsec from 0 degrees, for 0.5 μsec it has a strength of 110 mA and for succeeding 5 μsecs it has a strength of 30 mA. Waveform 47 is the "write" current. It begins 4 μsec before 0 degrees, lasts for 10 μsec and is of 30 mA strength. Finally, waveform 48 is the data strobe signal. It occurs 11 μsec following 0 degrees and terminates at 15 μsec following 0 degrees. The 0 degree point corresponds to a 0 degree angle between phasor 39 and the x axis in FIG. 3.
FIGS. 6 and 7 are the detailed schematic diagrams of element 10. FIG. 6 illustrates, basically, the digital portion of element 10 and FIG. 7 illustrates the analog portion of element 10.
Control, in element 10, originates in registers 150 and 151. Register 150, is an eight-bit shift register. It has its last output connected to the input of eight-bit register 151, and the second output of register 151 is applied through inverter 153 to the input of registers 150. Thus, register 150 and 151 form a single sixteen-bit shift register (152) having the inverse of its tenth stage fed back to the register's input. Register 152 is clocked with a 1 MHz clock, causing the outpus of register 152 to display respectively delayed square waveforms which are "high" for 10 μsec and "low" for 10 μsec.
To develop the two sinusoidal driving voltage waveforms of FIG. 4, particular outputs of register 152 are combined in a resistor network similar to the networks commonly used in digital to analog converters. Specifically, to develop the sinusoidal portion of waveform 43, leads 101 through 110 of register 152 are applied, each through a resistor of a predetermined value, to a first terminal. The signal developed at the first terminal is applied to an inverting integrator which comprises differential amplifier 210, a feedback resistor 211, and a feedback capacitor 212. The output of the integrator develops the desired waveform.
The values of the resistors connected to leads 101 through 110 are selected to best match the desired sinusoidal waveform. One acceptable set of values is:
a 100 Kohm resistor connected to lead 101;
a 33 Kohm resistor connected to lead 102;
a 22 Kohm resistor connected to lead 103;
a 18 Kohm resistor connected to lead 104;
a 15 Kohm resistor connected to lead 105;
a 15 Kohm resistor connected to lead 106;
a 18 Kohm resistor connected to lead 107;
a 22 Kohm resistor connected to lead 108;
a 33 Kohm resistor connected to lead 109; and
a 100 Kohm resistor connected to lead 110.
It may be noted that the D/A converter construction of the analog sine waveform circuit provides very precise control over the timing and the amplitude of the derived signal. Also, the realization of the analog waveforms at low current levels, as compared with a realization at high current levels, substantially reduces expected switching noise problems.
It should also be noted that maximum output at the first terminal is developed when leads 101 through 110 are all "high." However, waveform 43 at the output of amplifier 210 reaches its maximum (t 1 in FIG. 4) 270 degree after the maximum at the first terminal. The 270 degree delay results from the 90 degree lag of the integration process and from the 180 degree phase shift of the inversion. Thus, the maximum in the voltage waveform at the first terminal coincides with the maximum in current waveform 41.
The sinusoidal portion of waveform 44 is developed in a manner which identically parallels the development of waveform 43, to wit, leads 106 through 115 of register 152 are connected through a set of resistors to a second terminal, and the signal developed at the second terminal is applied to inverting amplifier 220 which, in combination with feedback resistor 221 and capacitor 222, integrates and inverts the voltage developed at the second terminal.
As depicted in FIG. 5, the 0 degree point is the point when current 41 reaches its peak (corresponding to point 36 in FIG. 3). The 0 degree point also coincides, as indicated above, with the maximum of the voltage waveform at the first terminal. This instant, in accordance with FIG. 4, is the time when waveform 44 is turned "on;" and 90 degrees prior to that instant is the time when waveform 43 is turned "on." Since a maximum at the first terminal is reached when lead 110 goes "high," the 0 degree instant is signified by the down transition of a pulse formed by the AND function of the signal on lead 109 and the inverse of the signal on lead 110. This is accomplished, in FIG. 6, with inverter gate 161 and AND gate 162. The pulses developed by gate 162 (appearing at times t 2 and t 3 ) can be used to turn "on" waveform 44 and to turn "off" waveforms 43 and 44. The -90 degree instant, which is the time when waveform 44 is turned "on" is signified by the down transition of a pulse formed by the AND function of signals from leads 104 and 115. This is accomplished, in FIG. 6, with AND gate 163.
The actual switching of waveforms 43 and 44 is done in an analog switch circuit 164 which comprises two FET transistors, each controlled by a digital signal. The FET transistors act as a switch. When the control signal connected to a transistor's gate is "low," the analog signal connected to the transistor's source appears at the transistor's drain. When the gate is "high," the analog signal does not appear at the drain. Thus, waveform 43 (out of amplifier 210) is connected to the first FET input of switch circuit 164, and waveform 44 (out of amplifier 220) is connected to the second FET of switch circuit 164. The Q output of D flip-flop 166 controls the first FET and the Q output of flip-flop 165 controls the second FET.
Flip-flop 166 is responsive to a low voltage indication signal on lead 169 and is clocked with a signal expressed by the Boolean function 109·110·Q 166 +104·115·Q 166 , developed with AND gates 163 and 167 and OR gate 168. Q 166 and Q 166 refer to the Q and Q outputs of flip-flop 166. Flip-flop 165 is responsive to Q 166 and is clocked with the signal of gate 162, which is the signal 109·110. The "reset" input of flip-flop 165 is also connected to Q 166 .
The turn "on" and turn "off" operations of the circuit can best be described by first assuming a low voltage condition on line 169. When a low voltage condition occurs, line 169 goes "high" causing the Q output of flip-flop 166 to go high whenever a clock pulse appears at the output of OR gate 168. Once the Q output of flip-flop 166 goes "high," Q 166 goes low, gate 167 (developing the expression 109·110) is disabled, gate 163 (developing the expression 104·115) is enabled and the Q output of flip-flop 165 goes "high" (because of the "reset" connection).
Thus, shortly after the detection of a low voltage condition, flip-flops 166 and 165 deliver "high" control voltages to switch circuit 164 (switching waveforms 43 and 44 "off"), flip-flop 165 continues to be clocked with pulses 109·110 and flip-flop 166 is clocked with pulses 104·115.
When line 169 reverts to its normal "low" position, the very next pulse of gate 163 (at position -90 degree) changes the state of flip-flop 166, causing Q 166 to go "low" and turning "on" waveform 43 in accordance with FIG. 4. At the very next pulse of gate 162 (at position 0 degrees) flip-flop 165 is caused to change state, turning "on" waveform 44 in switch circuit 164. Also, gate 163 is disabled and gate 167 is enabled, permitting both flip-flops 165 and 166 to be clocked with gate 162 pulses which occur at 0 degrees. This permits a proper turn "off," when necessary, at time t 3 .
The low voltage indication signal emanates from low voltage detector circuit 154 followed by OR gate 155. Low voltage detector circuit 154 comprises a plurality of comparators, each comprising a predetermined fraction of a supply voltage to a reference potential. An indication of a low supply voltage from any of the comparators results in a "high" signal delivered to OR gate 155 which, in turn, delivers the "high" signal to flip-flop 166.
A secoond lead of OR gate 155 is responsive to the store enable input on lead 12. Whenever it is desired to disable block 70, the store enable lead is set "high," causing OR gate 155 to deliver a "high" signal to flip-flop 166.
In addition to the low voltage indication and the turn "on" and turn "off" circuitry, FIG. 6 includes logic for developing the control signals of FIG. 5.
Waveform 45 (FIG. 5) is the data read waveform. As indicated previously, it occurs 3.5 μsec after 0 degrees and is 0.5 μsec wide. In FIG. 6, the data read pulse is generated with AND gate 171 which is responsive to lead 103, lead 112, and to the clock which drives register 152. Gate 171 is also responsive to NOR gate 172 which combines the input data inverted with gate 173, and the Q output of flip-flop 165. When the Q output of flip-flop 165 is low, data is applied to AND gate 171 and is transferred to the output of gate 171 (lead 174) at the appropriate time.
Waveform 46 (FIG. 5) is the read enable waveform, and is developed by combining two waveforms; one beginning at 0.5 μsec past 0 degrees and lasting 0.5 μsec, and one beginning at 1 μsec past 0 degrees and lasting 5 μsec. The first waveform is developed in AND gate 175 which is responsive to leads 101 and 110, to the clock signal, and to a read enable control signal. The read enable control signal is applied to gate 175 through NOR gate 176 controlled by the Q output of flip-flop 165. The second waveform is developed in AND gate 177 which is responsive to the output signal of NOR gate 176 and to leads 111 and 106.
Waveform 47 (FIG. 5) is the write waveform. It is obtained by combining in AND gate 178 lead 106 with the write enable control signal obtained from NOR gate 179 which, in turn, is controlled through the Q output of flip-flop 165.
Finally, waveform 48 (FIG. 5) is the data strobe waveform. It begins at 11 μsec past 0 degrees and lasts for 4 μsec. In FIG. 7 it is obtained with AND gate 181 connected to leads 101 and 115.
FIG. 7 depicts memory block 70 and some of the attendant control circuits, the majority of which are analog.
The output signal of block 70 is amplified in detecting amplifier 71 which is a differential amplifier of standard design. Since the data output on bus line 61 is valid only at certain times, the output of amplifier 71 is strobed by the strobe signal (out of AND gate 181 in FIG. 7) in AND gate 72.
To select a particular memory block within block 70, one of the selection lines (26, 27, 28 and 29) must be activated. This is accomplished with selection network 74 which is responsive to register selection signals on leads 14 and 15. Network 74 may be a standard two line to four line converter, such as Texas Instrument, Incorporated, integrated circuit SN75462.
To drive the field currents required for block 70, two amplifiers of identical construction may be employed. FIG. 7 illustrates one of the amplifiers (75) in detail, while depicting the other amplifier (76) in block diagram form. Amplifier 75 is a class B amplifier having two complementary sections. One section includes transistors 81, 82, and 83 and the other section includes transistors 84, 85, and 86. Input signals are applied to transistors 81 and 84, connected in a common emitter mode, with resistors 91 and 94 and diodes 66 and 67 forming the input biasing network. Resistors 92 and 95 are respectively connected to the collector terminals of transistors 81 and 84 while resistor 97 connects between emitter terminals of transistors 81 and 84 and ground. The base of transistor 82 is connected to the collector terminal of transistor 81 while the base of transistor 85 is connected to the collector terminal of transistor 84. The collector terminal of transistor 82 is connected to the base of transistor 83 while the collector of transistor 85 is connected to the base of transistor 86. Across the base-emitter junction of transistors 83 and 86 are connected, respectively, resistors 93 and 96. The emitters of transistors 83 and 86 are joined, wherefrom negative feedback is provided to the joined emitters of transistors 81 and 84 through a network comprising resistor 98 connected in parallel to capacity 99. The output of amplifier 75 is derived from the joined emitters of transistors 83 and 86.
To erase the data in block 70, a pulse is provided at the clear input of element 10 on line 13. That pulse is applied, in FIG. 7, to multivibrator 22 which develops a pulse of appropriate duration. That pulse is enhanced in transistor 122 and is applied to the clear terminal of block 70 on line 23.
Finally, block 130, in response to the digital control signals developed in gates 171, 175, 177, and 178, develops the correct magnitudes for the control signals illustrated in FIG. 5.
The data pulse signal of AND gate 171 is applied to the base of transistor 131. Transistor 131 is connected in a common emitter mode, with the collector current determined by the value of resistor 133 and the voltage across it. This current is applied to bleeder resistor 132 and to input port 24 of block 70 through capacitor 134.
The "write enable" signal of gate 178 is applied to the base of transistor 135. Transistor 135 is connected in a common emitter mode, delivering a current to port 21 that is determined by collector resistor 138.
The "read enable" signal, as indicated previously, is composed of two components; one provided by gate 175 and one provided by gate 177. The output signals of gates 175 and 177 are applied, through resistors 139 and 140, respectively, to transistor 141 which is connected in a common emitter mode. The current delivered by transistor 141 is determined by collector resistor 143. | Disclosed is a bubble memory system adapted for construction on a single construction unit such as a pluggable card and for providing to prospective users a standard interface including an input data port, an output data port, a clear port, a store enable port, read and write enable ports, register select ports and a clock port. In the memory system, a plurality of bubble memory chips are interconnected in parallel with each of the chips being separately accessed for writing or reading purposes with the aid of the register select ports. Common control of the bubble memory chips is obtained through digitally generated control signals. Low voltage protection is provided by appropriately turning off the in-plane rotating field when the power source exhibits a low voltage condition, thereby protecting the stored data. | 6 |
[0001] This application claims the benefit of the Patent Korean Application No. 10-2005-0091804, filed on Sep. 30, 2005, which are hereby incorporated by reference as if fully set forth herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a laundry device, more particularly, to a detergent box assembly having a new structure which can supply detergent smoothly.
[0004] 1. Discussion of the Related Art
[0005] In general, a laundry device is classified into a pulsator type washing machine having a drum vertically mounted therein and a drum type washing machine having a drum horizontally mounted therein.
[0006] Since the drum is horizontally mounted in the drum type washing machine as mentioned above, washing is performed by dropping the laundry loaded into the drum.
[0007] A detergent box assembly, one of compositions of the drum type washing machine, is employed for supplying various kinds of detergents used in washing together with wash water.
[0008] As shown in FIG. 1 , a conventional detergent box assembly includes a dispenser body 10 in communication with a tub 2 by a bellows 12 , a detergent box 20 drawably provided within the dispenser body 10 for holding various detergents therein and a wash water dispenser 30 for supplying wash water into the detergent box 20 .
[0009] An outlet pipe 11 is outwardly projected from the dispenser body 10 and in communication with a rear lower portion of the dispenser body 10 . The bellows 12 is connected to the outlet pipe 11 .
[0010] When washing is performed in a state of detergent being supplied into the detergent box 20 , wash water is supplied. The wash water is supplied into the space having detergent therein through the dispenser body 10 .
[0011] Thus, the detergent is discharged into the dispenser body 10 together with the wash water, and then the detergent and wash water pass through the outlet pipe 11 and the bellows 12 to be supplied into the tub 2 .
[0012] However, according to the conventional detergent box assembly, if wash water reaches a predetermined level and water supply is stopped, the detergent flowing from the detergent box 20 into the dispenser body 10 cannot be discharged through the outlet pipe 11 smoothly. In spite of the remaining detergent, the water level is lowered drastically. Thereby, there may be a problem that the detergent is remaining within the dispenser body 10 due to the decrease of water currents.
[0013] Also, while the detergent and wash water are discharged through the outlet pipe 11 , too much wash water is discharged and some of the wash water forms vortex. Thereby, since the wash water which has formed vortex goes around an end of the outlet pipe 11 , some of the wash water and detergent which flows along the vortex are not discharged. Thus, there may be another problem that the detergent remains within the dispenser body 10 .
[0014] At that time, since the detergent which remains around the outlet pipe 11 of the dispenser body 10 contains some moisture, the detergent is getting cakery, not in a powdery state, to be stuck on the portion adjacent to the outlet pipe 11 .
[0015] Also, there may be still another problem in the conventional detergent box assembly. When wash water is supplied, the stuck detergent prevents the wash water from being discharged through the outlet pipe.
[0016] Especially, the stuck detergent is getting increased every washing. Still worse, the stuck detergent closes some portion of the outlet pipe 11 to cause backflow.
SUMMARY OF THE INVENTION
[0017] Accordingly, the present invention is directed to a method for water supply in a laundry device.
[0018] An object of the present invention is to provide a method for water supply in a laundry device which prevents detergent from remaining/being stuck in/to a dispenser body by discharging detergent/wash water more smoothly.
[0019] Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
[0020] To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a method for water supply in a laundry device includes: (a) step for supplying water; (b) step for temporarily stopping water supply for a predetermined time in the middle of the water supply; and (c) step for re-starting water supply after the predetermined time and finishing water supply to a predetermined water level.
[0021] Here, (a) step includes steps of controlling a water supply valve based on a control signal for performing cycles to start water supply; sensing the laundry amount during the water supply and setting a water level corresponding to the sensed laundry amount; and defining the set water level as the predetermined water level of (c) step.
[0022] Also, (b) step is performed, if the present water level according to the water supply of (a) step reaches a water level frequency prior to a discretional predetermined value with respect to the water level frequency corresponding to the predetermined water level, compared with the predetermined frequency corresponding to the predetermined water level of (c) step.
[0023] At that time, the discretional predetermined value may be a frequency between 0.1˜0.5 kHz.
[0024] Also, the predetermined time for temporarily stopping the water supply in (b) step may be between 1˜5 sec.
[0025] Preferably, (b) step is performed at least one time after the water supply starts.
[0026] Also, preferably, (b) step is performed at least one time during the water supply, in case that the water supply of (a) step is for a main washing.
[0027] Furthermore, (b) step may be performed in the beginning of the water supply.
[0028] On/off of the water supply valve may be alternatively repeated in (b) step.
[0029] The on/off operation, which is one time of (b) step, may be repeatedly performed within 3 to 10 times.
[0030] The water supply of (c) step is finished, if the present water level according to the water re-supply reaches the predetermined water level frequency.
[0031] It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:
[0033] FIG. 1 is a sectional view illustrating key parts of a conventional drum type washing machine according to the prior art;
[0034] FIG. 2 is a block view illustrating a laundry device according to an embodiment of the present invention;
[0035] FIG. 3 is a sectional view illustrating key parts of a detergent box assembly of the laundry device according to the embodiment of the present invention; and
[0036] FIG. 4 is a flow chart illustrating a method for water supply in the laundry device according to the embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0037] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
[0038] Referring to the drawings, a method for water supply in a laundry device according to the present invention will be described as follows.
[0039] First of all, referring to FIGS. 2 to 4 , a preferred embodiment of the present invention will be described in detail.
[0040] A laundry device according to the embodiment of the present invention includes a water supply valve 110 , a detergent box assembly 120 , a tub 130 , a water level sensor 140 and a controller 150 , as shown in FIG. 2 .
[0041] The water supply valve 110 selectively opens/closes a pipe way of a water supply pipe 4 connected to a water pipe 5 .
[0042] The water supply valve 110 is controlled to be on/off by the controller 150 .
[0043] As shown in FIG. 2 , the detergent box assembly 120 includes a detergent box 121 , a dispenser body 122 and a wash water dispenser 123 . The detergent box 121 holds detergent therein and the detergent box 121 is provided within the detergent. The dispenser body 122 supplies wash water drawn through the water supply pipe 4 into the detergent box 121 .
[0044] An outlet pipe 124 is projectedly formed in a downside of a rear surface of the dispenser body 122 . An end of a bellows 125 is connected to the outlet pipe 124 and the other end of the bellows 125 is connected to the tub 130 .
[0045] At that time, the wash water dispenser 123 is connected to the water supply pipe 4 .
[0046] Next, the tub 130 stores wash water therein and a drum 131 for having the laundry therein is rotatably mounted within the tub to perform actual washing therein.
[0047] The water level sensor 140 senses a water level of the tub 130 and transmits water level frequencies variable based on a water level to the controller 150 .
[0048] The controller 150 controls various operation parts of the laundry device such as various valves and a motor. Commonly, the controller 150 is a micom and a water level frequency value for the laundry amount is stored in look-up-the-table method.
[0049] A method for controlling water supply in the laundry device having the above configurations according to the embodiment of the present invention will be described, referring to FIG. 4 .
[0050] The method for controlling water supply in the laundry device according to the embodiment of the present invention includes a water supply step (S 100 ), a temporary stop step (S 200 ) and a final water supply step (S 300 ).
[0051] Each step will be described in detail.
[0052] First, the water supply step (S 100 ) is performed by the controller 150 of the laundry, if a control signal for performing washing is inputted.
[0053] At that time, the control signal is created by a user's operation of various switches provided on a control panel (not shown) and the controller 150 receives the signal.
[0054] If the signal is inputted in the middle of checking whether a signal for performing cycles is inputted by the controller 150 , the controller 150 controls the water supply valve 110 to perform water supply (S 120 ).
[0055] Here, when the water supply valve 110 is on, the water supply is opened.
[0056] Wash water supplied through the water pipe 5 is flowing along the water supply pipe 4 and passes through the wash water dispenser 123 , to be supplied into the detergent box 121 . Hence, the wash water together with detergent stored in the detergent box 121 is flowing to the dispenser body 122 , the outlet pipe 124 and the bellows 125 in order. Finally, the wash water is supplied into the tub 130 .
[0057] While the above water supply steps are performed, the controller 150 operates the drum 131 to sensing the laundry amount and sets a water level corresponding to the sensed laundry amount (S 130 ).
[0058] At that time, the set water level is diffused and defined as a water level frequency (hereinafter, a predetermined frequency) to be stored in the controller 150 . The controller 150 determines when the water supply is finished based on the set water level.
[0059] Next, the temporary stop step (S 200 ) will be described in detail.
[0060] In the temporary step (S 200 ), water supply is temporarily stopped for a predetermined time before the water supply is finished.
[0061] Here, the time when the water supply is finished is the time when the water level reaches the predetermined frequency F 1 stored in the controller 150 .
[0062] The temporary stop step (S 200 ) is performed if the water level frequency F 2 sensed by the water level sensor reaches a frequency F 3 prior to a discretional predetermined value with respect to the predetermined frequency F 1 . 10 .
[0063] That is, the controller 150 repeatedly receives the present water level frequency F 2 sensed by the water level sensor 140 (S 210 ) and repeatedly checks whether the frequency F 2 reaches the frequency F 3 (for example 19.5 kHz) prior to 0.5 kHz with respect to the predetermined frequency Fl(for example 20 kHz (S 220 ). Hence, if the present water level frequency F 2 reaches the frequency F 3 , the controller 150 controls the water supply valve 110 to stop water supply temporarily (S 230 ). At that time, the discretional predetermined value is a frequency between 0.5˜0.1 kHz.
[0064] Alternatively, the discretional predetermined value may be out of the range.
[0065] However, if the discretional predetermined value is more than a frequency of 0.5 kHz, the next step of the final water supply (S 300 ) should be performed for a relatively long time. Thus, detergent may be remaining again. Also, if the discretional predetermined value is less than a frequency of 0.1 kHz, the final water supply step (S 300 ) may not be performed for a enough time to remove remaining detergent. Thereby, it is not preferred.
[0066] Preferably, the time for stopping the water supply in the temporary stop step (S 200 ) is between 1˜5 sec.
[0067] Alternatively, the time may also be out of the range. However, if the water supply is stopped during the time longer than the maximum of the above range, detergent may be stuck. Thus, even though the next step of final water supply is performed, the stuck detergent may not be removed smoothly. If the water supply is stopped during the time shorter than the minimum of the above range, that is, the final water supply is started before the range of the time, water currents are not changed enough. Thus, detergent and wash water are not discharged through the outlet pipe 124 , and come around the outlet pipe 124 . Thereby, the detergent may remain near the outlet pipe 124 after the final water supply step (S 300 ) is completed, which is not preferred.
[0068] As described above, when the series of water supply stop step are performed, most wash water temporarily remaining within the body dispenser is discharged through the outlet pipe 124 . At that time, detergent which may not discharged together with the wash water may be remaining in a portion near the outlet pipe 124 within the dispenser body 122 .
[0069] However, the remaining detergent will be completely removed in the final water supply step (S 300 ) which will be described later.
[0070] Meanwhile, the temporary stop step (S 200 ) may be performed one time and alternatively may be performed at least two times, as needed.
[0071] Next, the final water supply step (S 300 ) will be described in detail.
[0072] In the final water supply step (S 300 ), after the temporary stop step (S 200 ) is completed, the water supply valve 110 is controlled to re-start water supply to the predetermined frequency (that is, the final water level). Thereby, detergent remaining in a portion near the outlet pipe 124 of the dispenser body 122 is completely removed.
[0073] More specifically, the detergent, which is not discharged through the outlet pipe 124 of the dispenser body 122 in the water supply step (s 100 ), is remaining in a portion of the bottom of the dispenser body 122 near the outlet pipe 124 . But, before the detergent is stuck and getting hard, the re-water supply of the final water supply step (S 300 ) is performed and the detergent may be completely discharged through the outlet pipe 124 .
[0074] At that time, the reason why the detergent is not completely discharged is that some of wash water forms vortex due to too much discharge of the wash water such that the wash water turns around an entrance of the outlet pipe 124 . That is, some of detergent is around together with the wash water turning around the outlet pipe 124 and remains near the outlet pipe 124 during the temporary stop step (S 200 ) after the water supply step (S 100 ).
[0075] Thus, thanks to the sequential performance of the water supply step (S 100 ), the temporary stop step (S 200 ) and the final water supply step (S 300 ), the detergent is preventing from remaining within the dispenser body 122 .
[0076] The method for water supply in the laundry device according to the embodiment of the present invention may be alternated.
[0077] For example, the time when detergent and wash water are mixedly supplied may be in a preliminary washing or a main washing.
[0078] In the preliminary washing, the detergent may be perfectly prevented from remaining within the dispenser body 122 by the processes described above. When water supply is performed for a long time such as in the main washing, the detergent is flowing to a front portion within the dispenser body 122 due to the vortex generated in the portion near the outlet pipe 124 and stuck on the front portion.
[0079] Thus, when water supply is performed for a long time such as in the main washing, it is preferred that the water supply valve 110 is controlled to be on/off at least one time.
[0080] Also, preferably, the on/off control of the water supply valve 110 is performed in the beginning of the water supply, because most of detergent is moving together with wash water into the dispenser body 122 in the beginning of the water supply.
[0081] At that time, the on/off control of the water supply valve 110 may be varied based on the time of entire water supply, and it is preferred that the on/off control of the water supply valve 110 is more than 3 times and less than 10 times.
[0082] If the on/off control of the water supply valve 110 is performed too often, the entire water supply is increased to cause user's dissatisfaction, and if the on/off control of the water supply valve 110 is not performed for a long time, detergent may be flowing to a front portion within the dispenser body 122 .
[0083] The method for water supply in the laundry device may be varied into various embodiments, as needed.
[0084] Described before, the method for water supply in the laundry device has following advantageous effects.
[0085] First, since water supply is temporarily stopped and re-started, the method for water supply in the laundry device of the present invention has an advantageous effect that detergent is prevented from remaining within the dispenser body.
[0086] Second, since the time before the water supply is completed is perceived through the water level frequency checked by the water level sensor, it is possible to determine the precise time for water supply, for temporarily stopping water supply and for final water supply.
[0087] Third, since the on/off control of the water supply is additionally performed in case the water supply is performed for a long time, the problem of remaining detergent can be solved perfectly.
[0088] 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 spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. | A method for water supply in a laundry device is disclosed. An object of the present invention is to provide a method for water supply in a laundry device which prevents detergent from remaining/being stuck in/to a dispenser body by discharging detergent/wash water more smoothly. A method for water supply in a laundry device includes (a) step for supplying water; (b) step for temporarily stopping water supply for a predetermined time in the middle of the water supply; and (c) step for re-starting water supply after the predetermined time and finishing water supply to a predetermined water level. | 3 |
FIELD OF THE INVENTION
The present invention relates to the feedback of channel related information in a Multiple-Input Multiple-Output (MIMO) system.
BACKGROUND
In a wireless communication system implementing link adaptation, a receiver such as a mobile terminal feeds back channel information to a transmitter such as a base station so that the transmitter can adapt its transmission to the receiver in dependence on channel conditions.
MIMO refers to the use of multiple transmit antennas and multiple receive antennas for the transmission of a signal in order to improve performance in a wireless communication system. A highly schematised block diagram of a MIMO system is shown in FIG. 1 . The system comprises a transmitter 2 having multiple antennas 6 ( 1 ) . . . 6 (n) and a receiver 4 having multiple antennas 8 ( 1 ) . . . 8 (m). For example, in a cellular communication system like the 3GPP Long Term Evolution (LTE) standard, the transmitter 2 may be a base station (e.g. eNode-B in the 3GPP terminology) and the receiver 4 may be a mobile terminal (user equipment or UE in the 3GPP terminology). The transmitter 2 transmits a signal on some or all of its antennas 6 , and the receiver 4 receives the signal on some or all of its antennas 8 . To achieve good closed-loop performance, the transmitter 2 may perform MIMO “pre-coding” whereby it uses channel information to determine the relative amplitude and phase with which to transmit the signal on each antenna.
In general, this information has to be fed back from the receiver 4 . To reduce the amount of feedback overhead, a precoding matrix approach was proposed in D. Love and R. W. Heath, “Limited Feedback Precoding for Spatial Multiplexing Systems”, in Proc. IEEE Globecom 2003, pp. 1857-1861. The basic idea behind this approach is to quantize the MIMO channel using a codebook consisting of a set of pre-defined matrices. For each channel realization, the receiver 4 finds the best precoding matrix (according to some performance criteria) from the codebook shared between the receiver and the transmitter, and then feeds back only the index of this matrix to the transmitter. This index may be referred to as a precoding matrix indicator (PMI).
Another piece of information that the receiver 4 feeds back to the transmitter 2 is the rank indicator (RI). This provides the rank of the channel matrix, which is defined as the number of linearly independent columns of the channel matrix. For example, a N T =4×N R =4 channel matrix can have rank equal to 4, 3, 2 or 1 (rank≦min (N T ,N R )). The rank of the channel also determines the size of the precoding matrix to be used by the transmitter, i.e., the number of columns of the precoding matrix. Depending on the channel rank, the transmitter 2 will consider a specific subset of the full precoding codebook. Therefore, the transmitter 2 needs to know what rank the received PMI is referring to.
Further, in addition to the RI and PMI, the receiver 4 feeds back a channel quality indicator (CQI) to the transmitter 2 , indicative of some metric relating to the received quality on the downlink channel. The transmitter 2 can then also take this into account when adjusting its transmission to the receiver 2 , typically selecting the appropriate modulation scheme and code rate to match the receiver channel quality information.
As illustrated schematically in FIG. 2 , the downlink channel may be an Orthogonal Frequency Division Multiplexing (OFDM) channel comprising a plurality of frequency sub-bands 12 , with the sub-bands being grouped together into groups of sub-bands 14 . The feedback of the CQI information may be either frequency selective or non frequency selective. In the non frequency selective case, the receiver 4 simply feeds back a single wideband CQI for the whole channel. In the frequency selective case, the receiver 4 also feeds back a CQI for each of a plurality of groups of sub-bands 14 .
In the current 3GPP LTE standard, the rank indicator (RI), precoding matrix indicator (PMI) and channel quality indicator (CQI) are typically reported periodically from the UE to the eNode-B. This periodic reporting is based on a control signalling in the form of a set of parameters transmitted by the network via the eNode-B to the UE, which determine the periodicity of the different reports for a given feedback mode [3GPP TS 36.213, “Technical Specification Group Radio Access Network: Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Layer Procedures (Release 8)”, V8.3.0, May 2008, Section 7.2.2].
For the non-frequency selective periodic CQI modes, the UE reports in different uplink reporting instances a) RI and b) wideband CQI/PMI for the modes with PMI report or only wideband CQI for the modes with no PMI report [3GPP TS 36.213, “Technical Specification Group Radio Access Network: Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Layer Procedures (Release 8)”, V8.3.0, May 2008, Table 7.2.2-3].
For the frequency selective periodic CQI modes, the UE reports in different uplink reporting instances a) RI, b) wideband CQI/PMI for the modes with PMI report or only wideband CQI for the modes with no PMI report, and c) frequency selective CQI in terms of multiple sub-band CQIs [3GPP TS 36.213, “Technical Specification Group Radio Access Network: Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Layer Procedures (Release 8)”, V8.3.0, May 2008, Table 7.2.2-3].
The control signalling from the eNode-B to the UE may be transmitted on the Primary Downlink Control Channel (PDCCH) and the RI, PMI and CQI reports fed back from the UE to the eNode-B may be signalled on the Primary Uplink Control Channel (PUCCH). An example of the RI, PMI and CQI information sent on the PUCCH 20 is illustrated schematically in FIG. 3 a . Here, the PUCCH 20 comprises the sequential transmission in time on a plurality of reporting instances 22 ( t ), 22 ( t+ 1), 22(t+2), etc. Here, the first reporting instance comprises a report of the RI, the second reporting instance comprises a report of the wideband PMI and wideband CQI, and by way of example the next four reporting instances comprise respective reports of the sub-band CQI values for each of four groups of sub-bands 14 . Following the sub-band CQI reports, the sequence of an uplink reporting instance including the wideband PMI and CQI report followed by four reporting instances including sub-band CQI reports is repeated. That sequence may be repeated a number of times periodically, and after that the whole sequence may be repeated again periodically starting with another RI report and so on. The actual RI, PMI and CQI values reported will be updated with each periodic repetition on the relevant reporting instances. Note that FIG. 3 a shows an example of a frequency selective report, but it will be understood that a non-frequency selective report would contain the same sequence of RI, PMI and CQI reports, except that it would not include the sub-band CQI values.
However, in some cases the UE may for certain reasons not transmit on one or more reporting instances 22 of the PUCCH 20 . If an RI, PMI and/or CQI report is scheduled for such a reporting instance 22 , then this RI, PMI and/or CQI report is said to be “dropped” and it will not be transmitted. There are also certain cases where a higher priority uplink transmission may cause an RI, PMI and/or CQI report to be replaced on a certain reporting instance 22 . More specifically, when the UE has any other higher priority control information to be transmitted on the PUCCH, it will need to replace any RI, PMI and/or CQI report scheduled on that reporting instance 22 . In such cases, the RI, PMI and/or CQI report is again said to be “dropped” from the reporting instance 22 in question.
The 3GPP LTE standard allows the possibility of dropping the transmission of RI and wideband CQI or wideband CQI/PMI from a given reporting instance 22 for different reasons:
An aperiodic CQI report on PUSCH is requested, which will be transmitted instead of the scheduled periodic CQI report on PUCCH. A scheduling request (SR) needs to be transmitted by the UE, which will cause a drop of information on PUCCH. A positive or negative acknowledgment (ACK/NACK) needs to be transmitted by the UE, which will cause a drop of information on PUCCH. A UE Discontinuous Reception (DRX) inactive cycle will cause any uplink transmissions to be invalid (typically for power saving reasons). RI and wideband CQUPMI collisions due to the RI offset parameter set to O=0 by the eNode-B, in which case the UE will drop the wideband CQI/PMI transmission. In the presence of a measurement gap, the UE will drop all uplink transmissions overlapping with the gap.
The missed transmission of this information in the uplink can cause a problem, because without the RI and/or PMI transmission, the CQI values sent on the following reporting instances have no meaning. In fact, all the RI/PMI/CQI reports are linked, and the wideband PMI is computed based on the reported rank while the sub-band CQI values are determined by the UE based on both the reported rank and precoding matrix. So the meaning of the reported PMI depends on the RI, and the meaning of the reported CQI depends on the RI and PMI. This implies that the eNode-B needs to know the correct RI in order to correctly interpret the reported PMI, and needs to know the correct RI and PMI in order to correctly interpret the reported CQI
The current status of the LTE specification is to do nothing and accept losing the RI or PMI information in the presence of a drop of a scheduled RI or PMI transmission.
A possible alternative solution is to configure the UE to reschedule the RI report by shifting it along in time to another reporting instance after the reporting instance at which it was originally scheduled. All subsequent reports are then also shifted along in time by the same number of reporting instances 22 . This means that under normal circumstances, the eNode-B should still receive the RI correctly in order to interpret the subsequent PMI and CQI reports.
An example of this is illustrated in FIG. 3 b , which shows the case of a DRX inactive cycle in which any uplink transmissions are invalid, or a measurement gap in which the uplink signal is not transmitted. Consider a scenario where a measurement gap or a UE DRX inactive cycle overlaps with a PUCCH reporting instance 22 containing an RI transmission, as depicted in the FIG. 3 b (the DRX/GAP period can last multiple WB/CQI reporting intervals, but for illustration only one WB/CQI interval is shown as overlapping the DRX/GAP period). Under the current status of the LTE specification, any reports in the DRX/GAP period would simply be dropped and not retransmitted. But, under the possible alternative solution, the RI report is re-scheduled to the next available reporting instance 22 ( t+ 4) immediately after the end of the DRX/GAP period, and the subsequent sequence of PMI and CQI reports is shifted along in time accordingly.
Another example is illustrated in FIG. 3 c , which shows the case where the UE receives data transmission from the eNode-B and in response must send back a positive acknowledgement signal ACK ora negative acknowledgement signal NACK to the eNode-B in the next reporting instance 22 of the PUCCH 20 . That means that the RI, PMI or CQI report that was scheduled for that reporting instance must be dropped, since the ACK has higher priority than the RI, PMI and CQI reports. Again, under the current status of the LTE specification, that report would simply be omitted altogether and not retransmitted. This would include the possibility an RI report being replaced by the ACK/NACK. But, under the possible alternative solution, the RI report would be re-scheduled to the next reporting instance 22 ( t+ 1) immediately after the ACK/NACK, with the subsequent sequence of PMI and CQI reports being shifted along in time accordingly. Similar comments apply to any higher priority transmission that the UE must make to the eNode-B, which will displace an RI report.
Another alternative for the case of frequency-selective CQI report is to sacrifice one of the sub-band CQI reports every time a drop of RI or PMI transmission has occurred. Examples of this are illustrated in FIGS. 3 d and 3 e . In FIG. 3 e for example the next sub-band CQI report CQI 1 is deliberately omitted from transmission by the UE, and the eNode-B is configured to expect that CQI report CQI 1 to be dropped. Similarly in FIG. 3 d , the sub-band CQI report CQI 3 is deliberately omitted from reporting instance 22 ( t+ 4), and the eNode-B is configured to expect that accordingly.
Yet another alternative would be to retransmit the dropped RI at the next opportunity, and to shift the subsequent sequence of PMI and CQI reports by one place, until the next wideband CQI/PMI reporting instance, thereby again sacrificing one of the sub-band CQI reports.
When an RI report is dropped, the current state of the LTE specification causes a problem because the eNode-B will lose the information of an entire reporting interval between one RI and the next.
However, the alternative solution discussed in relation to FIGS. 3 b and 3 c is also problematic because it can lead to a misalignment between eNode-B and UE in the interpretation of the different reports. For example, if a control signalling from the eNode-B is not properly detected by the UE, perhaps due to a poor quality PDCCH, then the UE may miss the transmission of downlink data, and not report the corresponding ACK/NACK in the uplink. In this case, there may be a discrepancy between what the UE transmits and what the eNode-B expects to receive. So referring to FIGS. 3 b and 3 c for example, the UE may transmit with the scheduling shown in the top row whilst the eNode-B expects to receive the scheduling shown in the bottom row. Thus the eNode-B's expectation will not be aligned with the UE's actual PUCCH transmission.
The alternative solution of FIGS. 3 d and 3 e reduces the impact of this misalignment problem to some extent. In FIG. 3 e for example, the misalignment will always be regained again by reporting instance 22 ( t+ 3), and in FIG. 3 d it will be regained by reporting instance 22 ( t+ 5). However, the situation in FIGS. 3 d and 3 e is still problematic in another way because it requires one of the sub-band CQI reports to be sacrificed.
It is an aim of the present invention to find an alternative solution to the problem of RI dropping.
SUMMARY
According to one aspect of the present invention, there is provided a method of feeding back information from a receiver to a transmitter, the method comprising: transmitting signals from the transmitter to the receiver over a wireless multiple-input-multiple-output channel; based on the received signals, transmitting a plurality of reports back from the receiver to the transmitter in a periodic sequence of respective time intervals, the reports of each period comprising at least an indication of a pre-coding matrix and an indication of a rank of the pre-coding matrix; in response to an event, omitting the report comprising the rank indication from one of said periods; at the receiver, determining a subsequent report comprising an indication of a pre-coding matrix on the basis of a predetermined default rank, and transmitting that report to the transmitter; and at the transmitter, interpreting the indication of the pre-coding matrix without a report of a rank indication for said period by instead using the predetermined default rank, and using that interpretation to control a transmission of a subsequent signal to the receiver over the wireless multiple-input-multiple-output channel.
By completely omitting the rank indicator report and instead using a default rank, rather than rescheduling the rank indicator report, the present invention provides improved reliability. In embodiments, it may also allow the possibility of using full frequency selective CQI information.
According to another aspect of the present invention, there is provided a method of feeding back information from a receiver to a transmitter, the method comprising: receiving signals at the receiver from the transmitter over a wireless multiple-input-multiple-output channel; based on the received signals, sequentially transmitting a plurality of reporting instances back from the receiver to the transmitter including at least a report indicating a pre-coding matrix; in the event that a report indicating a rank of the respective pre-coding matrix is not transmitted back from the receiver to the transmitter before transmitting the report indicating a pre-coding matrix, then instead, at the receiver, determining the report indicating the pre-coding matrix using a default rank, and transmitting that report back to the transmitter.
According to another aspect of the present invention, there is provided a method of feeding back information from a receiver to a transmitter, the method comprising: receiving signals at the receiver from the transmitter over a wireless multiple-input-multiple-output channel; based on the received signals, transmitting a plurality of reports back from the receiver to the transmitter in a periodic sequence, each period comprising a plurality of reports at respective time intervals, the reports of each period including an RI report and a PMI report, but at least an RI report in one of said periods being replaced with one of an ACK, NACK and SR or missed due to a DRX cycle; at the receiver, determining a PMI report of said period on the basis of a default rank, and transmitting that report back to the transmitter.
According to further aspects of the invention, there are provided corresponding receivers, transmitters, and communication systems comprising transmitter and receiver. For each of the receiver and transmitter, there is also provided a corresponding computer program product comprising code which when executed on a processor of the receiver or transmitter respectively operates it to perform the method steps of the receiver or transmitter respectively.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention and to show how it may be carried into effect, reference will now be made by way of example to the accompanying drawings in which:
FIG. 1 is a schematic block diagram of a wireless communication system,
FIG. 2 is a schematic representation of an OFDM channel,
FIG. 3 a is a schematic representation of feedback from a UE on a PUCCH,
FIG. 3 b is another schematic representation of feedback on a PUCCH,
FIG. 3 c is another schematic representation of feedback on a PUCCH,
FIG. 3 d is another schematic representation of feedback on a PUCCH,
FIG. 3 e is another schematic representation of feedback on a PUCCH,
FIG. 3 f is another schematic representation of feedback on a PUCCH,
FIG. 3 g is another schematic representation of feedback on a PUCCH,
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
According to a preferred embodiment of the present invention, a default RI value is assumed in case the RI report is dropped. Both the base station (eNode-B) and the mobile terminal (UE) assume a default RI value, preferably RI=1, in the case where the RI report on PUCCH is dropped. Thus, instead of rescheduling the RI report or omitting a sub-band CQI report as discussed in relation to FIGS. 3 b - 3 e , the RI report itself is omitted and a default value used.
This is illustrated schematically in FIGS. 3 f and 3 g . In FIG. 3 f , a DRX inactive cycle or measurement gap lasts until reporting instance 22 ( t+ 3), causing the RI report to be dropped. However, the RI report is not rescheduled and does not displace any other report. Instead, the reports simply continue as previously scheduled from reporting instance 22 ( t+ 4) onwards. However, the UE computes those reports on the basis of a default RI value, preferably RI=1. The eNode-B is aware of the mechanism that has led to the drop of the RI transmission, and hence knows that it should use the default RI value to interpret subsequent MI and/or CQI reports, instead of relying on an actual RI report. That is to say, the eNode-B is pre-configured with the default-value. (Although note, in the case of FIG. 3 f , the eNode-B will not be able to use the sub-band CQI reports at reporting instances 22 ( t+ 4) and 22(t+5), unless it is agreed to retransmit earlier the wideband CQI/PMI report.)
Similarly, in FIG. 3 g , a data transmission from the eNode-B requires the UE to transmit a response such as an ACK in the reporting instance 22 ( t ) in place of the RI report, causing the RI report to be dropped. Again, the RI report is not rescheduled and does not displace any other report. Instead, the reports simply continue as previously scheduled from reporting instance 22 ( t+ 1) onwards.
Another RI dropping scenario would occur if any higher priority control information (aperiodic CQI report, SR, ACK/NACK or other) needs to be transmitted on the uplink PUCCH in place of a scheduled RI report, in which case that scheduled RI transmission is dropped for that reporting instance in favour of the required higher priority transmission. In this case, instead of the RI report, both the UE and eNode-B are again configured to use a default RI value, preferably RI=1. That is, the UE determines subsequent PMI and CQI reports relative to the default RI value, and in complement the eNode-B interprets the subsequent PMI and CQI reports using the default RI value. In this sense, both the UE and eNode-B “assume” a default RI value.
Another scenario would be that the RI parameter offset O, signalled by higher layers and denoting the interval between RI and WB CQI/PMI reports happens to be zero. This leads to a collision between the RI and WB CQI/PMI reports. In that case, as stated by the 3GPP specifications, the WB CQI/PMI is dropped, and the RI is still transmitted. Under these circumstances, in the case of frequency selective CQI, the SB CQI become useless since they cannot be correctly interpreted by the eNodeB. In contrast, the preferred solution will keep the transmission of the WB CQI/PMI in place by using a default rank value (RI=1). All the following WB CQI/PMI and SB CQI will be computed and transmitted based on the default rank value
In addition, in a preferred scheme the UE may retransmit the wideband CQI and PMI report when the wideband CQI/PMI transmission is dropped. That is, if a DRX inactive cycle or measurement gap overlaps with a scheduled wideband PMI and CQI report, or if any other higher priority control information needs to be transmitted on the uplink PUCCH in place of a scheduled wideband PMI and CQI report, then that scheduled wideband PMI/CQI transmission is dropped for that reporting instance and may be transmitted on a subsequent reporting instance, preferably the next reporting instance. This may involve a subsequent sub-band CQI report being omitted, analogously to the omission in FIGS. 3 d and 3 e.
The preferred scheme is summarised as follows.
In the case where the RI transmission on PUCCH is dropped, both UE and base station (eNode-B) assume a default RI value RI=1. In the case where the wideband CQI or the wideband CQI/PMI transmission on PUCCH is dropped, then:
a) for non-frequency selective CQI report modes, do nothing (since the wideband CQI or wideband CQI/PMI will anyway be transmitted at the next reporting instance); b) for frequency selective CQI report modes, do nothing and wait for the next wideband CQI/PMI reporting instance, or retransmit the wideband CQI or the wideband CQI/PMI in place of a single sub-band CQI report, and then go back to the normal reporting instants.
The above solution guarantees a default mode of operation that is agreed between the UE and the e-Node-B. With the approach based on a default rank mode, both the UE and the e-Node-B can safely rely on a fallback transmission mode in case of drop of information. This is in contrast to the techniques of the prior art, where RI retransmission forces the eNode-B to use only part of the frequency selective CQI report, which implies reduced information for frequency selective scheduling in the current CQI/PMI reporting cycle.
In addition, the proposed solution has the advantage of simplicity and the advantage of not requiring a specific additional operation mode necessary for the retransmission of dropped RI and/or PMI as proposed in the prior art.
The above solution is general, and does not depend on the kind of event causing the UE to drop an RI/PMI/CQI transmission. The solution provides improved reliability (preferred default mode is based on rank 1 ), and the possibility of using full frequency selective CQI information.
It will be appreciated that the above embodiments have been described only by way of example. For instance, although the above has been described in terms of a UE and eNode-B, the present invention can apply to any kind of mobile terminal and base station, or most generally any system of wireless transmitter and receiver in which the receiver feeds back information to the transmitter. Further, although the above has a preferred application to 3GPP LTE standards, it may have an application to other wireless communications systems: the terms pre-coding matrix indicator or PMI, rank indicator or RI, and channel quality indicator or CQI, or similar, are not intended to refer to their specific definitions under any one particular standard. In general, pre-coding matrix can refer to any matrix determining the amplitudes and phases with which to transmit a signal on the antennas of a communication system having multiple transmit and receive antennas, and rank can refer to the rank of any channel matrix. Similarly, channel quality indicator can in general refer to any metric relating to the received quality on the downlink channel, whose interpretation when fed back to the transmitter is dependent on the rank and/or pre-coding matrix. Furthermore, where the above refers to reporting instances, it will be understood that this may refer to time intervals of one or more uplink sub-frames or any other time transmission instances of any uplink channel. Other applications and configurations may also be apparent to the person skilled in the art given the disclosure herein. The scope of the invention is not limited by the described embodiments. | The invention relates to a method of feeding back information from a receiver to a transmitter, and also a corresponding receiver, transmitter, system comprising a receiver and transmitter, and computer program products for performing the steps of the receiver and transmitter respectively. The method comprises: receiving signals at the receiver from the transmitter over a wireless multiple-input-multiple-output channel; and, based on the received signals, transmitting back reports from the receiver to the transmitter including a report indicating a pre-coding matrix and a report indicating a rank of the pre-coding matrix. In the event that the report indicating the rank is not transmitted, the receiver instead uses a default rank to determine the report. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to saw blades of the welded edge and chemically homogeneous type, i.e. blades made of a single material. In particular, it relates to new and improved tooth geometry for saw blades which employ a positive rake angle and a radial relief back.
It has long been recognized that structural and solid metal cutting saw blades for band saws and hack saws need certain qualities if they are to function in an efficient manner. For example such blades must be strong, smooth running, have good heat dissipation and have a long life, i.e. remain sharp.
The above and other desirable features of saw blades are achieved in two basic ways: first, through tooth geometry i.e. gullet size, relief angles, rake angle, wedge angle, as well as tooth size and pitch and second, blade construction i.e. solid blades and welded-edge blades.
It is known, for example, that welded edge blades exhibit a tooth tip portion of a high hardness, high strength material and a base portion of a strong flexible material. A typical construction is disclosed in U.S. Pat. No. 4,292,871 to Neumeyer et al, which is incorporated herein by reference. It is also known that some blades which provide for reduced vibration, noise, chatter, etc. can be prepared by the arrangement and form of the teeth. For example, see U.S. Pat. Nos. 4,179,967 to Clark and 4,232,578 to Stellinger et al.
Despite the ready availability of known and useful, commercially accepted standard tooth geometries, some of which maybe found in wood cutting blades, it has been found that unlike wood cutting applications various metal cutting applications require special blade tooth geometries and special blade constructions. In such situations it is particularly useful if the advantages of various blade tooth geometries enhance the known advantages of special blade construction.
It is therefore an object of the present invention to provide a new tooth geometry for saw blades which will provide strength, good heat dissipation, smooth cutting and long life.
It is another object of the present invention to provide a new tooth geometry for use with metal cutting welded-edge blades as well as chemically homogeneous blades.
It is a further object of the present invention to provide an improved tooth geometry for a metal cutting saw blade which has a positive rake angle and increased tooth mass while maintaining a large gullet for efficient chip removal.
It is a still further object of the present invention to provide improved tooth geometry for welded-edge saw blades wherein a long weld line between the tooth and the backing blade is employed thus providing a stronger bond between the two.
The above and other objects and advantages of the present invention will become more apparent when considered in connection with the following description and accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is an enlarged side view of a segment of a saw blade embodying the present invention;
FIG. 2 is an enlarged side view of a portion of the saw blade segment shown in FIG. 1; and
FIG. 3 is an enlarged side view of the upper portion of a tooth of the saw blade segment shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIGS. 1 and 2, a welded-edge type saw blade 10 is provided with a plurality of teeth 12 separated by gullets 14. In the embodiment shown, a variable pitch saw blade is depicted, i.e. the distance "x" between apices 16 of adjacent teeth 12 varies from tooth to tooth whereby the pitch is defined as the reciprocal of the distance "x" (in inches).
As will be noted, each tooth 12 is provided with a positive rake angle "a" and a radial relief back 18. Each tooth also includes a substantial tip including angle "b", a gullet radius "c" and a depth "d". The radial relief back 18 dimension "r" is determined by the relationship between the pitch, depth, gullet radius and a 15° to 20° tangential plane at the tip of each tooth 12. The radial relief back starts at the tooth tip which is the intersection of a line formed by the toothed edge and a line inclined from 15° to 20° from said toothed edge. The radius of the radial relief back is located on a line perpendicular to the inclined line which runs through the intersection of the toothed edge line and the inclined line.
In order to provide the advantages of the present invention in a saw blade, the positive rake angle "a" should be no less than 7° and no more than 121/2°, preferably 7 1/2°; the tip included angle "b" should be between 61° and 64° preferably 62 1/2°; the depth of each tooth should be about 0.5 times the reciprocal of the pitch; and the gullet radius should be equal to about 0.23 to 0.24 times the reciprocal of the pitch of the tooth.
When one employs the above noted tooth geometry, one is able to create a longer cross-sectional area at the weld line, up to about 45% above known designs, thus increasing the tooth shear strength and reducing the tendency to strip teeth on structural applications. In addition, the greater tip mass due to the unique geometry of the radial relief back gives faster heat dissipation and reduces tip temperature so as to maintain high tip hardness.
In illustration of the above, FIG. 3 depicts a portion of a tooth created using the design criteria of the present invention. As shown, a tip portion 20 is welded, preferrably by electron beam welding techniques, to a base portion 22 along weld line 24. Line 26 illustrates a typical angular relief back and the cross hatching illustrates the increased surface area of a tooth provided by the radial relief back 18 of the present invention. As illustrated, the dimension "l" is the increased length of the weld line 24 provided by the present invention.
In order to illustrate the basis of the present invention, the working dimensions of a variable pitch, welded-edge saw blade employing the teachings of the present invention are shown in Table I below:
TABLE I__________________________________________________________________________ Distance Tip RadialTooth Rake Gullet Between Tooth Included Relief Weld# Angle-"a" Radius-"c" Teeth-"x" Depth-"d" Angle-"b" "r" Length__________________________________________________________________________1 71/2° .058 .250 .115 621/2° .4539 .0922 71/2° .053 .230 .105 621/2° .4284 .0903 71/2° .042 .185 .083 621/2° .3648 .0854 71/2° .038 .170 .075 621/2° .3557 .0785 71/2° .042 .185 .083 621/2° .3648 .0856 71/2° .053 .230 .105 621/2° .4284 .0907 71/2° .058 .250 .115 621/2° .4539 .092__________________________________________________________________________ NOTE: All dimensions are in inches unless otherwise noted.
In comparison and contrast to the above, a typical non-radial relief back welded-edge saw blade would have weld length of about .062 inches for each tooth.
The variable pitch, welded-edge saw blade illustrated in Table I was subjected to testing along with 4 commercially available blades and a second blade made in accordance with the present invention as follows:
Blade #1-4/6 welded-edge, 5° positive rake, bent tipHardness RC 66.6 (commercially available blade)
Blade #2-4/6 welded-edge, 5° positive rake, bent tipHardness RC 66.4 (commercially available blade)
Blade #3-4/6 welded-edge, 0° rake, straight relief back-Hardness RC 67.4 (commercially available blade)
Blade #4-4/6 welded-edge, 0° rake, straight relief back-Hardness RC 65.5 (commercially available blade)
Blade #5-4/6 welded-edge, 7 1/2° positive rake-Hardness RC 63.9
Blade #6-4/6 welded-edge, 7 1/2° positive rake-Hardness RC 65.5
Each of the above noted blades were used in test cuttings of a 6 inch I-beam under the following conditions:
______________________________________ Speed Feed______________________________________Cuts 1-5 150 fpm 75 lbs.Cuts 6-100 250 fpm 100 lbs.______________________________________
During the cutting tests, sound readings were taken and the results are as follows:
TABLE II______________________________________ 6" from cut 3' from cut______________________________________Blade #1 108 db 97 dbBlade #2 108 db 97 dbBlade #3 99 db 92 dbBlade #4 99 db 92 dbBlade #5 99 db 92 dbBlade #6 99 db 92 db______________________________________
As will be noted from the above, blades 5 and 6 made in accordance with the present invention exhibited an operating sound level at least as good as or better than the other blades tested.
Following the 100th cut, each of the blades were examined under a low power (10X) binocular microscope and evaluated for fracture and tooth wear. The following Table lists the results of said examination:
TABLE III______________________________________ Wear Tooth Fracture Least = 1 Per Foot @ 100th Cut Worst = 6______________________________________Blade #1 2.5 3Blade #2 4.0 4Blade #3 9.0 6Blade #4 13.5 5Blade #5 0 2Blade #6 0 1______________________________________
As will be noted from the above, Blades 5 and 6 provide superior results. As will also be noted, Blades 5 and 6 are welded-edge blades made in accordance with the teachings of the present invention.
While preferred embodiments have been shown and described, various 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. | A saw blade of the welded-edge or chemically homogeneous type having a tooth geometry featuring a positive rake angle and a radial relief back for cutting both structural and solid materials. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to an underground disaster prevention system and construction which can provide a temporary underground place of refuge in the event of an earthquake disaster or the like by effectively utilizing underground structures such as basements of multi-story buildings and the like, and, which can effectively prevent the entrance of spring water into the underground space.
The occurrence of a very destructive earthquake in the Tokai district of Japan in the near future has been forecast by seismic experts with a high probability. However, countermeasures against such a possible disaster have not been sufficiently planned. On the other hand, in view of the steep rise in land values, the utilization of deeper underground spaces for the construction of many kinds of facilities including shelters has been recently discussed. However, existing spaces in multi-story buildings, underground shopping areas and subway stations have been built quite deeply into the earth. Since the above-mentioned underground structures in comparison with ground-level facilities are soundly built against earthquake disasters, many lives could be saved if said underground spaces were effectively utilized. However, in the past many lives were lost in underground spaces mainly because of suffocation due to fire, smoke and poisoned air containing carbon monoxide etc. Also if the lights went out there would be the possibility of a serious panic occurring.
Furthermore, in the event of an earthquake or the like there is a high possibility of the occurrence of spring water but it is impossible to estimate where and to what extent the spring water will appear. Consequently, a safe place of refuge cannot be used if spring water enters into the basement or into the underground spaces.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an underground disaster prevention system and construction which can provide a temporary underground place of refuge at the time of an earthquake or the like by effectively utilizing underground spaces in structures such as basements of multistory buildings, underground shopping areas, subway stations etc.
It is another object of the present invention to provide an underground disaster prevention system and construction which is capable of supplying compressed air, of a higher pressure than the one at ground-level, into an underground space in order to prevent the inflow of flames, smoke and poisonous gases and also to provide underground illumination by effectively driving a independent electric power generator which generates necessary electric energy for keeping the illumination.
It is another object of the present invention to provide a disaster prevention system and construction for protecting people against the entrance of spring water that may occur in the event of a disaster.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are a construction view for explaining an underground space embodying the present invention;
FIG. 3 is a section taken on line III--III of FIG. 2;
FIG. 4 is a view showing, by way of an example, a solar ray collecting device which has been previously proposed by the present applicant.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a construction view for explaining an embodiment of the present invention. While an example of the invention is shown as applied to the underground space of a tall building. It will be understood that the invention is not limited to the embodiment shown and hereinafter it will be made clear that it can be applied to all kinds of underground spaces i.e. subway stations, underground shopping areas etc.
In FIG. 1, 10 is an underground space, 11 is a "spring water" bath provided at the lowest level, 12, 13 and 14 are underground parking garages. This is a typical underground area of a usual multistory building. The "spring water" bath 11 is intended to collect therein underground spring water and it is usually kept almost empty by constantly pumping out the water therefrom. Access to said "spring water" bath is usually prohibited and is allowed only in the case of a special need i.e. the bath is usually kept vacant. Cylinders 21 containing compressed air, (liquid air) are provided in said "spring water" bath area, control boxes 22 are arranged at each parking floor level as well and an independent power generator room 30 is provided possibly on the highest level below the street level. In the event of a major earthquake, utter confusion may arise on the street level due to the collapse of many buildings and the occurrence of fires. On the other hand, underground structures and facilities are quite safe except for the danger of fires which cause smoke and other poisonous gases that may be blown therein from the street level and all the power may fail. At present, if people take refuge in an existing underground space, they may suffer from oxygen deficiency and/or easily panic from fear of the dark.
In view of the above-mentioned circumstances, in the system according to the present invention, the provision is made that when any one pushes an "emergency" button on a control box located on each underground floor, all compressed air cylinders blow out compressed air automatically which flows toward the ground and thereby prevents flames, smoke and other poisonous gases from the street level to enter the underground areas. Thus outwardly directed air flow is effective for seeking a safe exit. When the above-mentioned emergency push button or other emergency button is pushed, the an independent power generator 23 is driven to restore the lighting in the underground spaces and it also supplies electric power for driving the sanitary and waste water treatment system. It is preferable that control boxes be arranged on all basement floors and that a guard be posted on the street level. When an emergency button on any box is pressed, compressed air is supplied automatically and a program is started to switch on the independent electric generator 23. While in the embodiment shown where many control boxes are located, it will be easily understood that a single control box may be used and many independent emergency buttons may be arranged at a plurality of places. In FIG. 1, a single large type generator 23 is used, but it is also possible to provide, instead of the one shown, a number of small type gasoline engine generators which, in the event of a disaster, can operate by gasoline taken from automobiles parked on that level. It serves two purposes: the supplying of fuel and the prevention of fire in the parking area. When a pipe 24 or the like is sunk into the soil of the bath area, spring water comes out therethrough. This pipe is equipped with a cock which is usually turned off. At a time of need the cock is turned on to allow the water to be used. Such problems as the supply of air, light and water and sanitary waste treatment can thus be solved.
Furthermore, according to the present invention, in addition to the air necessary for people to breath, oxygen (O 2 ) necessary for driving and operating the power generator is also obtained from said liquid air. Being supplied with liquid air and light oil stored for 3 days's use, the generator will work to produce electric power and distribute it to urgently needed areas, as for instance, for lighting the underground. From each of the automobiles parked in the underground parking areas a certain amount of fuel may be collected for use in power generation. The automobiles themselves may be used as safe, private living spaces.
By providing illumination, saving lives from possible suffocation and by operating information devices to gather real time data, it becomes possible to communicate with the outside world through a communication satellite with the use of a balloon type receiver-transmitter which may be prepared for such a purpose.
FIG. 2 is a construction view for explaining another embodiment of the present invention. FIG. 3 is a sectional view taken on line III--III of FIG. 2. In FIGS. 2 and 3, numeral 31 is soil (earth's crust), 32 is a metal plate with high heat conductivity, 33 is a wall element made of concrete or the like, 34a is a liquid air tank, 34b is a liquid air cylinder, 35 is piping, 36a and 36b are safety valves and 37 and 38 are liquid air discharging tanks. In the embodiment, in the underground space there is located a liquid air tank 34a and a liquid air cylinder 34b from which, in the event of an earthquake disaster, liquid air is discharged to freeze water existing in the soil around said underground space and thereby to form a solid layer of soil capable of blocking the entrance of the spring water into the underground space. This embodiment may be preferably applied to an underground space used as a refuge from a disaster shown in FIG. 1. That is to say, in the event of an earthquake or the like the valves of the liquid air tank 34a and liquid air tank 34b are opened to supply liquid air into the piping 35 and thereby water being contained in the surrounding soil is frozen. In case of a practical construction, as shown in FIG. 3, a number of metal plates 32 of high heat conductivity are arranged in contact with the soil's surface and piping is arranged along the connecting portions of the metal plates. Almost the full amount of water existing in the soil may be blocked by the metal plates 32 but it may enter into the underground space through the connecting portions of the metal plates 32. Consequently, it is efficient to lay out the piping along the joints of the metal plates as shown in FIG. 3. Furthermore, it is preferable to weld each of the pipes 35 onto the metal (steel) plate 32 so that when discharging liquid air into the pipes, water in the soil, along the metal plates' joints, may be quickly frozen to block the water's entrance. Since the cooled liquid air in the pipings 35 can also be quickly transferred to the soil's surface through metal plates 32, water in the soil can be quickly frozen to form an ice barrier (a frozen wall) all over the outer surface of the metal plates joined with each other. This ice barrier is effective enough to block the entrance of spring water or the like into the underground space. The liquid air discharged from the tank or the cylinder into the piping 35 cools down the surroundings through the piping wall and becomes vaporized and therefore the pressure in the piping 35 increases. When the pressure has increased to a specified value, the safety valve 36a is opened to release air from the piping into the discharge tank 37 through which air is supplied into the underground space without directly blowing onto a person's body or onto other objects. While in FIG. 2 there is shown the tank 37 located at the 1st basement floor, it may be placed at any desired level. When air pressure in piping 35 is further increased after the first safety valve 36a is opened, the second safety valve 36b operates at the specified pressure higher than the operating pressure of the first safety valve 36a in order to prevent the inside pressure of the piping 35 from rising above the upper limit of safety. In this case air from the safety valve 36b is also released into the discharge-tank 38 to avoid dangerous direct blowing out of the air. Furthermore, the underground space is equipped with the same facilities as those described in the prior embodiment, for instance, compressed air (liquid air), an independent power generator etc. In addition, an antenna is installed on the building top so as to ensure the possibility of communicating with the other stations. It will be easily understood that the underground space may be used besides as a parking floor shown, as office space, conference rooms or for any other desired purpose.
As is apparent from the foregoing description, according to the present invention, it may be possible to create an inexpensive, safe place of refuge in the case of a disaster, by utilizing an underground space capable of quickly and effectively preventing the entrance of spring water into it which may occur in the event of an earthquake.
Furthermore, the present applicant has previously proposed to focus sunlight or artificial light through lenses or the like, to guide them into a fiber optic cable, and to transmit them therethrough to any desired place where the light rays are used for illumination and for other purposes, as for instance, for increasing the culture of plants or for raising fish. Said solar ray collecting devices have already been put in to practice in cultivating plants and fish in the basements of buildings etc.
FIG. 4 is a view for explaining an embodiment of the afore-mentioned solar ray collecting device which comprises a transparent protective capsule 40, a number of Fresnel lenses 41, a lens system holder 42, a solar position sensor 43, optical fibers or a fiber optic cable 44 consisting of optical fibers (hereinafter called "light guides") having light-receiving ends set at the focal points of the Fresnel lenses, a holder 45 for the optical fibers or the fiber optic cable, an arm 46, a pulse motor 47, a horizontal revolution shaft 48 to be rotated by said pulse motor 47, a base plate 49 for holding the capsule 40, a pulse motor 50 and a vertical revolution shaft 51 to be rotated by the pulse motor 50. The position of the sun is detected by the solar position sensor 42 and its detection signal controls the pulse motor 47 of the horizontal shaft 48 and the pulse motor 50 of the vertical shaft 51 so as to direct the sensor 52 toward the sun, and the sunlight focused through each lens 41 is guided into the light guide through its light-receiving end-surface set at the focal point of the lens. Light guides 44 are bundled into a light guide cable 52 which can be led to any desired place where the light is needed as for instance to a basement wherein plant and fish are being cultivated. | A disaster prevention system for underground spaces has a compressed air supply system and an independent power generator installed in an underground space. In the event of a disaster, the compressed air supply system discharges compressed air into an underground space in order to maintain the air pressure therein at a higher level than that of the external atmosphere. The independent power generator generates electrical energy which provides the necessary lighting for the underground space. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a semiconductor device in which low-dielectric-constant insulators are used as interconnecting insulation layers (interlayer insulation films) so as to mitigate any wiring delay of signals (delay in wirings of interconnection) to improve device performance.
[0003] 2. Description of the Related Art
[0004] As semiconductor devices are made to have higher integration and smaller chip size, wirings are being made to scale down in length, to have narrower wiring pitches and to be formed in a larger number of metal layers (i.e., wirings are being made finer, more narrow-pitch and more multiple-layer). With such progress, the delay coming when signals pass through wirings, i.e., the wiring delay tends to increase. This is a problem of great proportions in using electronic equipment making use of semiconductor devices.
[0005] In general, the speed of signals which pass through wirings depends on the product (RC) of wiring resistance (R) and wiring-to-wiring capacitance (C). Hence, in order to mitigate the wiring delay, it is necessary to make the wiring-to-wiring capacitance small, i.e., to make the interconnecting insulation layer have a low dielectric constant.
[0006] As measures to lower the wiring resistance, it is set forward in high-performance semiconductor devices to change their wiring material from aluminum to copper. In particular, the damascene structure where copper wirings are buried in interconnecting insulation layers is actively applied in processing.
[0007] As measures to make the interconnecting insulation layer have a low dielectric constant, inorganic materials such as a silicon oxide film (SiO 2 : dielectric constant about 4.0) and a silicon nitoride film (SiN: dielectric constant about 7.0) formed by CVD (chemical vapor deposition) have conventionally been used in interconnecting insulation layers of semiconductor devices. Then, recently, these are succeeded by employment of a fluorine-dopped silicon oxide film (SiOF: dielectric constant about 3.6) as a material with low dielectric constant that can continue conventional processes.
[0008] However, the fluorine-doped silicon oxide film has a relatively high dielectric constant, and can not have a sufficient effect of lessening the wiring-to-wiring capacitance when it is used as the interconnecting insulation layer. Accordingly, in semiconductor devices since the generation of wiring process of 90 nm nodes, materials having much lower dielectric constant are required.
[0009] As materials of interconnecting insulation layers having a property that the dielectric constant is lower than 3.5, various materials are proposed. In rough classification, studies are made on what is called spin-on-glass materials with which substrates are coated followed by heating to form films, on organic materials similarly formed into films, and on methods of forming films by CVD.
[0010] As the spin-on-glass materials, there are materials containing a hydrogen silsesquioxane compound, a methyl silsesquioxane compound, and the like. The materials composed chiefly of a hydrogen silsesquioxane compound or a methyl silsesquioxane compound are preferred. In the present specification, a chief ingredient is a compounent of the hightest combination ratio (a mole ratio).
[0011] A coating solution composed chiefly of the hydrogen silsesquioxane compound is one prepared by dissolving the compound, which is represented by the general formula: (HSiO 3/2 ) n , in a solvent such as methyl isobutyl ketone. A substrate is coated with this solution, which is then subjected to intermediate heating at a temperature of approximately from 100° C. to 250° C., followed by heating at a temperature of from 350° C. to 450° C. in an inert atmosphere, e.g., in an atmosphere of nitrogen, so that an insulation layer is formed in which Si—O—Si bond networks are formed in ladder structure and which is finally chiefly composed of SiO.
[0012] A coating solution composed chiefly of the methyl silsesquioxane compound is one prepared by dissolving the compound, which is represented by the general formula: (CH 3 SiO 3/2 ) n , in a solvent such as methyl isobutyl ketone. A substrate is coated with this solution, which is then subjected to intermediate heating at a temperature of approximately from 100° C. to 250° C., followed by heating at a temperature of from 350° C. to 450° C. in an inert atmosphere, e.g., in an atmosphere of nitrogen, so that an insulation layer is formed in which Si—O—Si bond networks are formed in ladder structure and which is finally chiefly composed of SiO.
[0013] As organic insulation layer materials, polymeric materials such as polyimide, poly(p-xylylene), poly(arylene) ether, poly(arylene), benzcyclobutene and polynaphthalene, which are hydrocarbon type resins, are known in the art. These materials contain carbon atoms, in virtue of which the film is made to have a low density, and also the polarizability of molecules (monomers) themselves is made small, in virtue of which the film achieves a low dielectric constant.
[0014] As methods of more reducing the dielectric constant of interconnecting insulation layers such as the above spin-on-glass films, organic films and CVD films, it is known to form nano-pores in films to make the films into porous films. With regard to the above materials and processes, they are disclosed in International Technology Roadmap for Semiconductors, 1999 Edition, pp. 163-186, and Japanese Patent Applications Laid-open No. 2000-340569 and No. 2001-274239.
[0015] However, in the above related art, the interconnecting insulation layers having the property that the dielectric constant is lower than 3.5 involve a problem that the insulation layers have fundamentally lower mechanical strength such as hardness and elastic modulus than the Silicon oxide film and Silicon nitride film formed by CVD.
[0016] In such insulation layers, it has been considered not realistic that the nano-pores are formed in films to make the films into porous films in order to more reduce the dielectric constant, because this may come toward further deterioration of mechanical strength.
[0017] As a means for lowering the dielectric constant of insulation layers, insulating organic polymers such as polyimide are used in some cases. Such organic polymers are favorable because their dielectric constant is less than 4, but have disadvantages that they physically have a lower mechanical strength and also higher hygroscopicity and moisture permeability than inorganic films. When used as interconnecting insulation layers, they may also cause a problem on the reliability of devices, e.g., a lowering of mechanical strength of device structure and corrosion of wirings which is due to absorbed moisture.
SUMMARY OF THE INVENTION
[0018] Accordingly, especially in multi-layer wiring semiconductor devices employing the damascene structure where copper wirings are filled in interconnecting insulation layers, the present inventors have made studies on how to lower the dielectric constant of the whole of interconnecting insulation layers while keeping the mechanical strength of device structure from lowering.
[0019] Under the technical background as stated above, the present invention proposes a method in which a stacked structure made up of the film with a low dielectric constant and the film with a high dielectric constant as stated above is formed and also the combination and structure of their materials are made optimum so that the achievement of both electrical properties and mechanical properties of insulation layers themselves can be materialized.
[0020] In particular, the present invention has made it possible to provide, in a semiconductor device having a stacked structure employing a damascene structure where copper wirings made to have low wiring resistance are filled in interconnecting insulation layers, a semiconductor device having highly reliable and high-performance characteristics which has mitigated the wiring delay of signals (delay in wirings of interconnection) while keeping the mechanical strength of interconnecting insulation layers from lowering.
[0021] The semiconductor device of the present invention is a semiconductor device having a substrate on which transistor elements and semiconductor circuit components have been formed, and stacked thereon a plurality of sets of conductor layers each having i) a first insulation layer, a second insulation layer and a third insulation layer and ii) a conductor wiring having been so formed as to extend through these three layers. Here, the insulation layers are so formed that the first and third insulation layers constituting each conductor layer are formed of silicon carbonitride, silicon carbide or silicon oxide, and a second insulation layer of a conductor layer positioned at a lower-layer part among the conductor layers contains silicon oxide, and a second insulation layer of a conductor layer positioned at an upper-layer part among them contains fluorine-doped silicon oxide or carbon-doped silicon oxide.
[0022] Here, where copper wiring is used as conductor wiring to serve as a component, the first insulation layer serves as an etch-stop film when insulation layers are holed in order to fill with the copper wiring. The third insulation layer also serves as a Cu-diffusion barrier film of the copper wiring.
[0023] Conventionally, silicon nitride films are used as the etch-stop film and Cu-diffusion barrier film. In the present invention, a film comprised of silicon carbonitride (Si—C—N: dielectric constant about 4.6), silicon carbide (Si—C: dielectric constant about 4.4) or silicon oxide is used, having lower dielectric constant than silicon nitride, and hence, even in the whole of conductor layers formed in multi-layer stacked structure, its dielectric constant can be reduced.
[0024] The second insulation layer of a conductor layer positioned at an upper-layer part among the conductor layers is formed of fluorine-doped silicon oxide or carbon-doped silicon oxide (dielectric constant: about 2.9). This enables more reduction of the dielectric constant of the whole of conductor layers than in a case in which all the second insulation layers constituting the corresponding conductor layers are formed of silicon oxide.
[0025] The semiconductor device of the present invention is also so constructed that the second insulation layer of a conductor layer positioned at a lower-layer part is comprised of an insulating film material having a dielectric constant of less than 3.0 and the second insulation layer of a conductor layer positioned at an upper-layer part is formed of fluorine-doped silicon oxide or carbon-doped silicon oxide. That is, the second insulation layers are made to differ in constituents between the conductor layer positioned at a lower-layer part and the conductor layer positioned at an upper-layer part so that the latter insulation layer can have a smaller dielectric constant than the former insulation layer.
[0026] The semiconductor device of the present invention is also so constructed that the second insulation layer of a conductor layer positioned at a lower-layer part is an insulation film having characteristics of a dielectric constant of less than 3.0 and containing SiO and that more than half of nano-pores present in the insulation film are chiefly comprised of pores of from 0.05 nm or more to 4 nm or less in diameter. In the present invention, as having the nano-pores in the film, the film density can be reduced, and, as making use of the insulation film having characteristics of a dielectric constant of less than 3.0 and containing SiO, the dielectric constant can be more reduced in the whole of conductor layers formed in multi-layer stacked structure.
[0027] Here, a method may be used in which the nano-pores are formed in the insulation film to lower its density and make its dielectric constant to that of vacuum. This can make the dielectric constant of the insulation film lower than the dielectric constant of the silicon oxide film. In particular, the size and density of such nano-pores may be controlled. This enables formation of an insulation film having any desired dielectric constant.
[0028] However, the size of the nano-pores to be incorporated in the insulation film must be controlled with great care because, if the nano-pores have a large diameter, problems may instead arise such that the mechanical strength as a structure of the insulation film lowers and the leak current flows greatly through the insulation film to lower the breakdown strength that is a characteristic feature as the insulation film.
[0029] Accordingly, in the present invention, the range of pore diameter is controlled so that the mechanical strength and breakdown strength of the insulation film can be kept from lowering. Here, the nano-pores may chiefly comprise pores of from 0.05 nm or more to 4 nm or less in diameter. In such a case, a semiconductor device having high reliability can be provided without lowering the mechanical strength of the insulation film.
[0030] The insulation film having the above nano-pores is formed of an insulation film composed chiefly of SiO, obtained by heating a spin-on film composed chiefly of a hydrogen silsesquioxane compound or a methyl silsesquioxane compound.
[0031] A coating solution composed chiefly of the hydrogen silsesquioxane compound is one prepared by dissolving the compound, which is represented by the general formula: (HSiO 3/2 ) n , in a solvent such as methyl isobutyl ketone. Also, a coating solution composed chiefly of the methyl silsesquioxane compound is one prepared by dissolving the compound, which is represented by the general formula: (CH 3 SiO 3/2 ) n , in a solvent such as methyl isobutyl ketone.
[0032] A substrate may be coated with any of these solutions, which is then subjected to intermediate heating at a temperature of approximately from 100° C. to 250° C., followed by heating at a temperature of from 350° C. to 450° C. in an inert atmosphere, e.g., in an atmosphere of nitrogen, so that Si—O—Si bond networks are formed in ladder structure and finally an insulation layer composed chiefly of SiO is formed.
[0033] In the insulation film composed chiefly of SiO, obtained by heating the spin-on film composed chiefly of the hydrogen silsesquioxane compound or methyl silsesquioxane compound, as a technique by which the diameter of the pores present in the insulation film is controlled, a method is available in which, e.g., a silsesquioxane compound solution is incorporated with components other than the solvent such as methyl isobutyl ketone so that the traces made upon decomposition of the main component in the film can form the pores, where the formation of pores is controlled by regulating film formation temperature to change the behavior of decomposition so that the range of pore diameter can be kept within a selective range.
[0034] As a method of coating the solution for forming the insulation film, it may include rotary coating, slit coating and printing. Then, the spin-on film thus formed is heated to form the insulation film. Hence, even where fine wirings are formed in a high density, a good step coverage can be achieved, compared with insulation films formed by CVD. Thus, this is advantageous in that any surface steps can be settled.
[0035] To deal with silicon wafers made to have larger diameter, a large-size film formation apparatus is required when insulation films are formed by CVD, and it follows that the cost of installation has a great influence on device cost. To solve such a problem, in the present invention, the insulation film is formed by a coating-and-heating system, and hence the installation cost can vastly be reduced. Thus, a great effect can be expected such that the investment cost of manufacture lines and further the device cost can be cut down.
[0036] In the case when the insulation film is formed by CVD, an alkylsilane compound or an alkoxysilane compound is used in a source gas as a chief component, and an insulation film finally chiefly composed of SiO is formed by ECR (electron cyclotron resonance), plasma-assisted CVD or the like.
[0037] In this case also, as a technique by which the diameter of the pores present in the insulation film is controlled, a method is available in which, e.g., a component having a high thermal decomposition temperature is fed as a source gas and the film is formed with heating at 350° C. to 450° C. so that the traces made upon decomposition of the main component in the film can form the pores.
[0038] In such a technique, the component having a high thermal decomposition temperature may be selected in variety, where the behavior of decomposition can be changed by regulating film formation temperature. Thus, the formation of pores may be controlled so that the range of pore diameter can be kept within a selective range.
[0039] The semiconductor device of the present invention also has, in the element and device peripheries, a barrier layer (called a guard ring layer in the present specification) comprised of a material capable of forming conductor wiring, in such a way that it encloses the element and device peripheries in order to prevent moisture absorption and moisture permeation from the surroundings of the semiconductor device. This can obstruct any water content which may come from the element surroundings or from the interface between the substrate and the interconnecting insulation layer, permeating through the interior of the interconnecting insulation layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] These and other features, objects and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings wherein:
[0041] FIG. 1 is a cross-sectional view of a semiconductor device having a stacked structure created in First Example of the present invention.
[0042] FIGS. 2A to 2 D show a flow sheet for illustrating how to produce the semiconductor device of First Example.
[0043] FIG. 3 is a graph showing diameter distribution of pores present in the insulation film.
[0044] FIG. 4 is a graph showing diameter distribution of pores present in the insulation film.
[0045] FIG. 5 is a flow sheet for illustrating how to produce a semiconductor device having a stacked structure according to Seventeenth Example.
[0046] FIG. 6 is a cross-sectional view for illustrating a logic semiconductor device created in Ninetheenth Example.
[0047] FIG. 7 is a cross-sectional view for illustrating a resin-encapsulated semiconductor device according to Twentieth Example.
[0048] FIG. 8 is a cross-sectional view for illustrating a wafer level chip-size-packaging semiconductor device according to Twenty-first Example.
[0049] FIGS. 9A and 9B are a cross-sectional view and a plan view, respectively, for illustrating a semiconductor device having a guard ring structure according to Twenty-second Example.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0050] Embodiments of the present invention are described below with reference to the accompanying drawings.
FIRST EXAMPLE
[0051] In the First Example, as shown in FIG. 1 , a six-layer wiring semiconductor device of Cu-wiring dual-damascene structure having six conductor layers 100 is produced.
[0052] On a semiconductor substrate 101 on which constituent elements such as MOS transistors (not shown) were formed by a commonly well known method, a silicon carbonitride film 102 serving as a first insulation layer of a first conductor layer 100 a was formed by CVD in a thickness of 40 nm. This first insulation layer serves as an etch-stop film when a hole is formed for forming a wiring pattern.
[0053] Next, a silicon oxide film 103 serving as a second insulation layer of the first conductor layer 100 a was formed by CVD in a thickness of 400 nm.
[0054] Next, a silicon carbonitride film 104 serving as a third insulation layer of the first conductor layer 100 a was formed by CVD in a thickness of 40 nm. This film serves as a first insulation layer of a second conductor layer 100 a , and plays a role also as an etch-stop film or Cu-diffusion barrier film when a hole is formed for forming a wiring pattern.
[0055] Next, a hole 117 was formed in the silicon carbonitride film 104 . The hole was formed using a photoresist and by forming a resist pattern by a known technique, followed by dry etching using the resist as a mask and using an etching gas capable of removing the silicon carbonitride film ( FIG. 2A ) Here, the hole is in a wiring size of the first conductor layer 100 a.
[0056] Next, in the same manner as the formation of the insulation layers of the first conductor layer 100 a , a silicon oxide film 105 serving as a second insulation layer of the second conductor layer 100 a was formed in a thickness of 400 nm, and a silicon carbonitride film 106 serving as a third insulation layer in a thickness of 40 nm.
[0057] Next, a hole 118 was formed in the silicon carbonitride film 106 ( FIG. 2B ). The hole was formed using a photoresist and by forming a resist pattern by a known technique, followed by dry etching using the resist as a mask and using an etching gas capable of removing the silicon carbonitride film.
[0058] Next, using the silicon carbonitride film 106 as a mask, a hole was formed in the silicon oxide film 105 by dry etching using a CF type gas capable of removing the silicon oxide film. Thus, at its lower part, the silicon oxide film 103 was uncovered through the hole 117 of the silicon carbonitride film 104 .
[0059] Subsequently, using the silicon carbonitride film 104 as a mask, a hole was formed in the silicon oxide film 103 through the former's hole 117 . Thus, at its lower part, the silicon carbonitride film 102 was uncovered.
[0060] Subsequently, the etching gas was changed for one capable of removing the silicon carbonitride film 102 , and then, using the silicon oxide film 103 as a mask, the silicon carbonitride film 102 was removed by dry etching through the former's hole to form a hole extending therethrough to reach the semiconductor substrate 101 . Here, the periphery of the hole 117 of the silicon carbonitride film 104 was also etched to make the hole 117 expand to the same size as the hole 118 of the uppermost silicon carbonitride film 106 . Thus, a wiring trench 119 was formed which extended through the layers to reach the semiconductor substrate 101 ( FIG. 2C ).
[0061] Next, a barrier metal layer 120 was formed on the inner surfaces of the wiring trench 119 , and thereafter the wiring trench 119 was filled with Cu 121 by well known plating. As the barrier metal, TiN was used in this Example.
[0062] Then, any unnecessary Cu film present on the uppermost silicon carbonitride film 106 was removed and the surface was cleaned to form a connecting plug and a wiring at the same time. To remove the Cu film, it is advantageous to use alumina or silica as abrasive grains and employ chemical mechanical polishing making use of an abrasive comprised of additives such as a Cu complexing agent and a surface-active agent.
[0063] In this polishing step, the silicon carbonitride film 106 corresponding to the uppermost layer was also removed by polishing. Thus, a dual-damascene structure in which a Cu wiring (inclusive of 120 and 121 ) was formed was produced. ( FIG. 2D )
[0064] Subsequently, the same process as the above was repeated twice to form a third conductor layer 100 c —a sixth conductor layer 10 f , and a six-layer Cu wiring structure is obtained. Here, insulation layers 106 , 108 , 110 and 112 are formed of silicon carbonitride films formed by CVD, and insulation layers 107 and 109 are formed of silicon oxide films. Also, insulation layers 111 and 113 are formed of fluorine-doped silicon oxide films.
[0065] Next, a silicon nitride film 114 was formed as the uppermost layer to produce a multi-layer wiring semiconductor device made up of a six-layer Cu wiring 115 ( FIG. 1 ).
[0066] Thus, a high-performance semiconductor device was obtained the dielectric constant of the whole of interconnecting insulation layers of which was lowered in virtue of the use of, as the etch-stop films or Cu-diffusion barrier films, the silicon carbonitride films having lower dielectric constant than silicon nitride films and also in virtue of the use of, in the upper-layer part of the multi-layer stacked structure, the fluorine-doped silicon oxide films having smaller dielectric constant than silicon oxide films.
SECOND EXAMPLE
[0067] In this Example, using the same techniques as those in First Example, fluorine-doped silicon oxide films (SiOF films) were formed by CVD also in respect of the insulation layers 107 and 109 . Next, the silicon nitride film 114 was formed as the uppermost layer to produce a multi-layer wiring semiconductor device made up of a six-layer Cu wiring 115 .
[0068] Thus, a high-performance semiconductor device was obtained the dielectric constant of the whole of interconnecting insulation layers of which was lowered in virtue of the use of, as the etch-stop films or Cu-diffusion barrier films, the silicon carbonitride films having lower dielectric constant than silicon nitride films and also in virtue of the use of, in the ⅓ (from the bottom) or more upper-layer part of the multi-layer stacked structure, the fluorine-doped silicon oxide films having smaller dielectric constant than silicon oxide films.
THIRD EXAMPLE
[0069] In this Example, using the same techniques as those in First Example, silicon carbide films were formed by CVD in respect of the insulation layers 102 , 104 , 106 , 108 , 110 and 112 . Next, the silicon nitride film 114 was formed as the uppermost layer to produce a multi-layer wiring semiconductor device made up of a six-layer Cu wiring 115 .
[0070] Thus, a high-performance semiconductor device was obtained the dielectric constant of the whole of interconnecting insulation layers of which was lowered in virtue of the use of, as the etch-stop films or Cu-diffusion barrier films, the silicon carbide films having lower dielectric constant than silicon nitride films.
FOURTH EXAMPLE
[0071] In this Example, using the same techniques as those in Second Example, silicon carbide films (SiC films) were formed by CVD in respect of the insulation layers 102 , 104 , 106 , 108 , 110 and 112 . Next, the silicon nitride film 114 was formed as the uppermost layer to produce a multi-layer wiring semiconductor device made up of a six-layer Cu wiring 115 .
[0072] Thus, a high-performance semiconductor device was obtained the dielectric constant of the whole of interconnecting insulation layers of which was lowered in virtue of the use of, as the etch-stop films or Cu-diffusion barrier films, the silicon carbide films having lower dielectric constant than silicon nitride films.
FIFTH EXAMPLE
[0073] In this Example, using the same techniques as those in First Example, carbon-doped silicon oxide films were formed by CVD also in respect of the insulation layers 111 and 113 to produce a multi-layer wiring semiconductor device made up of a six-layer Cu wiring 115 .
[0074] Thus, a high-performance semiconductor device was obtained the dielectric constant of the whole of interconnecting insulation layers of which was lowered in virtue of the use of, in the upper-layer part of the multi-layer stacked structure, the carbon-doped silicon oxide films having smaller dielectric constant than silicon oxide films.
SIXTH EXAMPLE
[0075] In this Example, using the same techniques as those in Second Example, carbon-doped silicon oxide films were formed by CVD also in respect of the insulation layers 107 , 109 , 111 and 113 to produce a multi-layer wiring semiconductor device made up of a six-layer Cu wiring 115 .
[0076] Thus, a high-performance semiconductor device was obtained the dielectric constant of the whole of interconnecting insulation layers of which was lowered in virtue of the use of, in the ⅓ (from the bottom) or more upper-layer part of the multi-layer stacked structure, the carbon-doped silicon oxide films having smaller dielectric constant than silicon oxide films.
SEVENTH EXAMPLE
[0077] In this Example, using the same techniques as those in Fifth Example, silicon carbide films (SiC films) were formed by CVD in respect of the insulation layers 102 , 104 , 106 , 108 , 110 and 112 . Next, the silicon nitride film 114 was formed as the uppermost layer to produce a multi-layer wiring semiconductor device made up of a six-layer Cu wiring 115 .
[0078] Thus, a high-performance semiconductor device was obtained the dielectric constant of the whole of interconnecting insulation layers of which was lowered in virtue of the use of, as the etch-stop films or Cu-diffusion barrier films, the silicon carbide films having lower dielectric constant than silicon nitride films.
EIGHTH EXAMPLE
[0079] In this Example, using the same techniques as those in Sixth Example, silicon carbide films were formed by CVD in respect of the insulation layers 102 , 104 , 106 , 108 , 110 and 112 . Next, the silicon nitride film 114 was formed as the uppermost layer to produce a multi-layer wiring semiconductor device made up of a six-layer Cu wiring 115 .
[0080] Thus, a high-performance semiconductor device was obtained the dielectric constant of the whole of interconnecting insulation layers of which was lowered in virtue of the use of, as the etch-stop films or Cu-diffusion barrier films, the silicon carbide films having lower dielectric constant than silicon nitride films.
NINTH EXAMPLE
[0081] In this Example, using the same techniques as those in First Example, carbon-doped silicon oxide films were formed by CVD in respect of the insulation layers 103 , 105 , 107 and 109 to produce a multi-layer wiring semiconductor device made up of a six-layer Cu wiring 115 .
[0082] Thus, a high-performance semiconductor device was obtained the dielectric constant of the whole of interconnecting insulation layers of which was lowered in virtue of the use of, in the lower-layer part of the multi-layer stacked structure, as the insulation films the carbon-doped silicon oxide films having small dielectric constant and also in virtue of the use of, in the upper-layer part of the multi-layer stacked structure, the fluorine-doped silicon oxide films having smaller dielectric constant than silicon oxide films.
TENTH EXAMPLE
[0083] In this Example, using the same techniques as those in Second Example, carbon-doped silicon oxide films were formed by CVD in respect of the insulation layers 103 and 105 to produce a multi-layer wiring semiconductor device made up of a six-layer Cu wiring 115 .
[0084] Thus, a high-performance semiconductor device was obtained the dielectric constant of the whole of interconnecting insulation layers of which was lowered in virtue of the use of, in the lower-layer part of the multi-layer stacked structure, as the insulation films the carbon-doped silicon oxide films having small dielectric constant and also in virtue of the use of, in the ⅓ (from the bottom) or more upper-layer part of the multi-layer stacked structure, the fluorine-doped silicon oxide films having smaller dielectric constant than silicon oxide films.
ELEVENTH EXAMPLE
[0085] In this Example, using the same techniques as those in Third Example, carbon-doped silicon oxide films were formed by CVD in respect of the insulation layers 103 , 105 , 107 and 109 to produce a multi-layer wiring semiconductor device made up of a six-layer Cu wiring 115 .
[0086] Thus, a high-performance semiconductor device was obtained the dielectric constant of the whole of interconnecting insulation layers of which was lowered in virtue of the use of, in the lower-layer part of the multi-layer stacked structure, as the insulation films the carbon-doped silicon oxide films having small dielectric constant, and also in virtue of the use of, in the upper-layer part of the multi-layer stacked structure, the fluorine-doped silicon oxide films having smaller dielectric constant than silicon oxide films and the use of, as the etch-stop films or Cu-diffusion barrier films, the silicon carbide films having lower dielectric constant than silicon nitride films.
TWELFTH EXAMPLE
[0087] In this Example, using the same techniques as those in Fourth Example, carbon-doped silicon oxide films were formed by CVD in respect of the insulation layers 103 and 105 to produce a multi-layer wiring semiconductor device made up of a six-layer Cu wiring 115 .
[0088] Thus, a high-performance semiconductor device was obtained the dielectric constant of the whole of interconnecting insulation layers of which was lowered in virtue of the use of, in the lower-layer part of the multi-layer stacked structure, the carbon-doped silicon oxide films having small dielectric constant, and also in virtue of the use of, in the ⅓ (from the bottom) or more upper-layer part of the multi-layer stacked structure, the fluorine-doped silicon oxide films having smaller dielectric constant than silicon oxide films and the use of, as the etch-stop films or Cu-diffusion barrier films, the silicon carbide films having lower dielectric constant than silicon nitride films.
THIRTEENTH EXAMPLE
[0089] In this Example, using the same techniques as those in First Example, in respect of the insulation layers 103 , 105 , 107 and 109 , spin-on films of a methyl isobutyl ketone solution composed chiefly of the hydrogen silsesquioxane compound were formed on the substrate, and thereafter heated at 100° C. for 10 minutes and then at 150° C. for 10 minutes and further at 230° C. for 10 minutes in an atmosphere of nitrogen by means of a hot plate.
[0090] Then, the films were further heated at 350° C. for 30 minutes in an atmosphere of nitrogen by means of a furnace to form insulation films in which Si—O—Si bond networks were formed in ladder structure and which were finally chiefly composed of SiO and had the pore-formation-controlled nano-pores in films. Thus, a multi-layer wiring semiconductor device made up of a six-layer Cu wiring 115 was produced. The holes were formed by dry etching using a CF type gas capable of etching SiO.
[0091] In the case of this Example, the above insulation layers are insulation films in which nano-pores having distribution characteristics (diameter distribution) as shown in FIG. 3 , chiefly containing pores of from 0.05 nm or more to 4 nm or less in diameter, are present, having dielectric constant of about 2.3.
[0092] The diameter distribution is determined by calculating diameter distribution of scattering matter in comparison with theoretical scattering intensity based on scattering functions which assume spherical scattering matter, on the basis of X-ray reflection measurement data and X-ray diffuse scattering measurement data which are obtained using an X-ray diffractometer for thin film evaluation (model: ATX-G) manufactured by Rigaku Corporation.
[0093] The above insulation films having the nano-pores in films also have characteristics of a Young's modulus of 12 Ga. For these characteristics, in respect of like films of 250 nm in layer thickness which have been formed on silicon wafers, the hardness of the films is determined on the basis of the hardness at a surface layer point of {fraction (1/5)} of the total layer thickness, by indentation micromechanical testing making use of Nano Indenter XP, manufactured by MTS Systems Corporation in U.S.A.
[0094] The Young's modulus is also the value at the surface layer point of {fraction (1/5)} of the total layer thickness and is the value calculated on the basis of the Poisson's ratio 0.17 of molten quartz. A silicon oxide film deposited with p-TEOS (plasma-Tetra-Ethly-Urtho-Silicate) called p-TEOS film in the present specification having substantially the same layer thickness and whose Young's modulus has been determined by the same method has characteristics of a Young's modulus of 70 Ga.
[0095] From the foregoing, the insulation films having the nano-pores in films were films having a Young's modulus of about 17% of that of the p-TEOS film, and low-dielectric-constant insulation films having superior mechanical properties were obtained, compared with low-dielectric-constant insulation films disclosed in Japanese Patent Application Laid-open No. 2000-340569.
[0096] Thus, a high-performance semiconductor device was obtained the dielectric constant of the whole of interconnecting insulation layers of which was lowered, keeping the mechanical strength of element structure from lowering, in virtue of the use of, in the lower-layer part of the multi-layer stacked structure, the insulation films having dielectric constant of less than 2.5 and superior film strength and also in virtue of the use of, in the upper-layer part of the multi-layer stacked structure, the fluorine-doped silicon oxide films having smaller dielectric constant than silicon oxide films.
FOURTEENTH EXAMPLE
[0097] In this Example, using the same techniques as those in Thirteenth Example, silicon carbide films were formed by CVD in respect of the insulation layers 102 , 104 , 106 , 108 , 110 and 112 . Next, the silicon nitride film 114 was formed as the uppermost layer to produce a multi-layer wiring semiconductor device made up of a six-layer Cu wiring 115 .
[0098] Thus, low-dielectric-constant insulation films having superior mechanical properties were obtained in virtue of the use of, as the etch-stop films or Cu-diffusion barrier films, the silicon carbide films having lower dielectric constant than silicon nitride films and also in virtue of the use of the insulation films having the nano-pores in films, specifying their pore diameter.
[0099] Then, a high-performance semiconductor device was further obtained the dielectric constant of the whole of interconnecting insulation layers of which was lowered, keeping the mechanical strength of element structure from lowering, in virtue of the use of, in the lower-layer part of the multi-layer stacked structure, as the second insulation layers the insulation films having dielectric constant of less than 2.5 and superior film strength and also in virtue of the use of, in the upper-layer part of the multi-layer stacked structure, the fluorine-doped silicon oxide films having smaller dielectric constant than silicon oxide films.
FIFTEENTH EXAMPLE
[0100] In this Example, using the same techniques as those in Thirteenth Example, in respect of the insulation layers 103 , 105 , 107 and 109 , spin-on films of a methyl isobutyl ketone solution composed chiefly of the hydrogen silsesquioxane compound were formed on the substrate, and thereafter heated at 100° C. for 10 minutes and then at 150° C. for 10 minutes and further at 230° C. for 10 minutes in an atmosphere of nitrogen by means of a hot plate.
[0101] Then, the films were further heated at 350° C. for 30 minutes in an atmosphere of nitrogen by means of a furnace to form insulation films in which Si—O—Si bond networks were formed in ladder structure and which were finally chiefly composed of SiO and had the pore-formation-controlled nano-pores in films. Thus, a multi-layer wiring semiconductor device made up of a six-layer Cu wiring 115 was produced. The holes were formed by dry etching using a gas capable of etching SiO.
[0102] In the case of this Example, the above insulation layers are insulation films in which nano-pores having distribution characteristics (diameter distribution) as shown in FIG. 3 , chiefly containing pores of from 0.05 nm or more to 4 nm or less in diameter, are present, having dielectric constant of about 2.7.
[0103] The diameter distribution is determined by calculating diameter distribution of scattering matter in comparison with theoretical scattering intensity based on scattering functions which assume spherical scattering matter, on the basis of X-ray reflection measurement data and X-ray diffuse scattering measurement data which are obtained using an X-ray diffractometer for thin film evaluation (model: ATX-G) manufactured by Rigaku International Corporation.
[0104] The above insulation films having the nano-pores in films also have characteristics of a Young's modulus of 11 Ga. For these characteristics, in respect of like films of 250 nm in layer thickness which have been formed on silicon wafers, the hardness of the films is determined on the basis of the hardness at a surface layer point of {fraction (1/5)} of the total layer thickness, by indentation micromechanical testing making use of Nano Indenter XP, manufactured by MTS Systems Corporation in U.S.A.
[0105] The Young's modulus is also the value at the surface layer point of {fraction (1/5)} of the total layer thickness and is the value calculated on the basis of the Poisson's ratio 0.17 of molten quartz. A p-TEOS film having substantially the same layer thickness and whose Young's modulus has been determined by the same method has characteristics of a Young's modulus of 70 Ga.
[0106] From the foregoing, the insulation films having the nano-pores in films were films having a Young's modulus of about 16% of that of the p-TEOS film, and low-dielectric-constant insulation films having superior mechanical properties were obtained, compared with low-dielectric-constant insulation films disclosed in Japanese Patent Application Laid-open No. 2000-340569.
[0107] Thus, a high-performance semiconductor device was obtained the dielectric constant of the whole of interconnecting insulation layers of which was lowered, keeping the mechanical strength of element structure from lowering, in virtue of the use of, in the lower-layer part of the multi-layer stacked structure, as the second insulation layers the insulation films having dielectric constant of less than 3.0 and superior film strength and also in virtue of the use of, in the upper-layer part of the multi-layer stacked structure, the fluorine-doped silicon oxide films having smaller dielectric constant than silicon oxide films.
SIXTEENTH EXAMPLE
[0108] In this Example, using the same techniques as those in Fifteenth Example, silicon carbide films were formed by CVD in respect of the insulation layers 102 , 104 , 106 , 108 , 110 and 112 . Next, the silicon nitride film 114 was formed as the uppermost layer to produce a multi-layer wiring semiconductor device made up of a six-layer Cu wiring 115 .
[0109] Thus, low-dielectric-constant insulation films having superior mechanical properties were obtained in virtue of the use of, as the etch-stop films or Cu-diffusion barrier films, the silicon carbide films having lower dielectric constant than silicon nitride films and also in virtue of the use of the insulation films having the nano-pores in films, specifying their pore diameter. Then, a high-performance semiconductor device was further obtained the dielectric constant of the whole of interconnecting insulation layers of which was lowered, keeping the mechanical strength of element structure from lowering, in virtue of the use of, in the lower-layer part of the multi-layer stacked structure, as the second insulation layers the insulation films having dielectric constant of less than 2.5 and superior film strength and also in virtue of the use of, in the upper-layer part of the multi-layer stacked structure, the fluorine-doped silicon oxide films having smaller dielectric constant than silicon oxide films.
SEVENTEENTH EXAMPLE
[0110] Seventeenth Example is an example in which the present invention is applied in forming Cu-wiring dual-damascene structure, and is described with reference to the FIGS. 5A to 5 D flow sheet.
[0111] On a semiconductor substrate 501 on which constituent elements such as MOS transistors (not shown) were formed by a commonly well known method, a silicon carbonitride film 502 serving as a first insulation layer of a first conductor layer was formed by CVD in a thickness of 40 nm. This first insulation layer serves as an etch-stop film when a hole is formed for forming a wiring pattern.
[0112] Next, a spin-on film of a methyl isobutyl ketone solution composed chiefly of the hydrogen silsesquioxane compound was formed on the substrate, and thereafter heated at 100° C. for 10 minutes and then at 150° C. for 10 minutes and further at 230° C. for 10 minutes in an atmosphere of nitrogen by means of a hot plate. Then, the film was further heated at 350° C. for 30 minutes in an atmosphere of nitrogen by means of a furnace to form an insulation film in which Si—O—Si bond networks were formed in ladder structure and which was finally chiefly composed of SiO and in which nano-pores having distribution characteristics (diameter distribution) as shown in FIG. 3 , chiefly containing pores of from 0.05 nm or more to 4 nm or less in diameter, were present, having dielectric constant of about 2.3. This film was formed in a thickness of 400 nm as a second insulation layer 503 of the first conductor layer.
[0113] Next, a silicon carbonitride film 504 serving as a third insulation layer of the first conductor layer was formed by CVD in a thickness of 40 nm. This film serves as a first insulation layer of a second conductor layer, and plays a role also as an etch-stop film or Cu-diffusion barrier film when a hole is formed for forming a wiring pattern.
[0114] Next, a hole 517 was formed in the silicon carbonitride film 504 . The hole was formed using a photoresist and by forming a resist pattern by a known technique, followed by dry etching using the resist as a mask and using an etching gas capable of removing the silicon carbonitride film ( FIG. 5A ). Here, the hole is in a wiring size of the first conductor layer.
[0115] Next, in the same manner as the formation of the second insulation layer 503 of the first conductor layer, an insulation film 505 in which nano-pores having distribution characteristics as shown in FIG. 3 , chiefly containing pores of from 0.05 nm or more to 4 nm or less in diameter, were present, having dielectric constant of about 2.3, which serves as a second insulation layer of the second conductor layer was formed in a thickness of 400 nm; and a silicon carbonitride film 506 serving as a third insulation layer in a thickness of 40 nm.
[0116] Next, a hole 518 was formed in the silicon carbonitride film 506 ( FIG. 5B ). The hole was formed using a photoresist and by forming a resist pattern by a known technique, followed by dry etching using the resist as a mask and using an etching gas capable of removing the silicon carbonitride film.
[0117] Next, using the silicon carbonitride film 506 as a mask, a hole was formed in the insulation film 505 by dry etching using a gas capable of removing the silicon oxide film. Thus, at its lower part, the insulation film 503 was uncovered through the hole 517 of the silicon carbonitride film 504 .
[0118] Subsequently, using the silicon carbonitride film 504 as a mask, a hole was formed in the silicon oxide film 503 through the former's hole 517 . Thus, at its lower part, the silicon carbonitride film 502 was uncovered. Subsequently, the etching gas was changed for one capable of removing the silicon carbonitride film 502 , and then, using the silicon oxide film 503 as a mask, the silicon carbonitride film 502 was removed by dry etching through the former's hole to form a hole extending therethrough to reach the semiconductor substrate 501 . Here, the periphery of the hole 517 of the silicon carbonitride film 504 was also etched to make the hole 517 expand to the same size as the hole 518 of the uppermost silicon carbonitride film 506 . Thus, a wiring trench 519 was formed which extended through the layers to reach the semiconductor substrate 501 ( FIG. 5C ).
[0119] Next, a barrier metal layer 520 was formed on the inner surfaces of the wiring trench 519 , and thereafter the wiring trench 519 was filled with Cu 521 by well known plating. As the barrier metal, TiN was used in this Example.
[0120] Then, any unnecessary Cu film present on the uppermost silicon carbonitride film 506 was removed by chemical mechanical polishing and the surface was cleaned to form a connecting plug and a wiring simultaneously. In this polishing step, the uppermost silicon carbonitride film 506 was not removed by the polishing to leave it. Thus, a dual-damascene structure in which a Cu wiring (inclusive of 520 and 521 ) was formed was produced. ( FIG. 5D ) Thus, a high-performance semiconductor device was obtained the dielectric constant of the whole of interconnecting insulation layers of which was lowered in virtue of the use of the low-dielectric-constant film as the second insulation layer 503 , which is the chief constituent layer of the interconnecting insulation layers.
[0121] In the construction of this Example, the device has a structure wherein the conductor layers are stacked in two layers. The conductor layers may twice or more repeatedly be stacked to obtain a semiconductor device having multi-layer wiring structure.
EIGHTEENTH EXAMPLE
[0122] In this Example, in the same manner as in Seventeenth Example, an SiO insulation film in which nano-pores having distribution characteristics as shown in FIG. 4 , chiefly containing pores of from 0.05 nm or more to 1 nm or less in diameter, were present, having dielectric constant of about 2.7, was formed in respect of the second insulation layer 503 of the second conductor to produce a dual-damascene structure in which a Cu wiring was formed.
[0123] Thus, a high-performance semiconductor device was obtained the dielectric constant of the whole of interconnecting insulation layers of which was lowered in virtue of the use of the low-dielectric-constant film in respect of the second insulation layer 503 , which is the chief constituent layer of the interconnecting insulation layers. The conductor layers may further twice or more repeatedly be stacked, whereby a high-performance semiconductor device having multi-layer wiring structure can be obtained with ease.
NINETEENTH EXAMPLE
[0124] FIG. 6 is a cross-sectional view of a logic semiconductor device. On a semiconductor substrate 601 , an element isolation region 602 was formed by known STI (shallow trench isolation), and MOS transistors 603 were formed in this element isolation region 602 (The hatching of a transistor is omitted for a figure to be looked easily). Then, a silicon oxide film 604 of about 50 nm thick and a BPSG (boron-phosphorus-silicate glass) film 605 of about 500 nm thick were formed by known CVD in order on the surface of the semiconductor substrate 601 inclusive of the MOS transistors 603 , followed by reflow annealing in, e.g., an atmosphere of nitrogen of 800° C. to 900° C.
[0125] Next, the surface of the BPSG film 605 was polished to make flat by chemical mechanical polishing (CMP), and thereafter a contact hole was formed. In this contact hole, a conducting plug 606 was formed. Here, any unnecessary tungsten present on the surface of the BPSG film 605 has been removed by known etchback processing.
[0126] Next, in the same manner as in Seventeenth Example, a silicon carbonitride film 607 serving as a first insulation layer of a first conductor layer. This first insulation layer serves as an etch-stop film when a hole is formed for forming a wiring pattern.
[0127] Next, a spin-on film of a methyl isobutyl ketone solution composed chiefly of the hydrogen silsesquioxane compound was formed on the substrate, and thereafter heated at 100° C. for 10 minutes and then at 150° C. for 10 minutes and further at 230° C. for 10 minutes in an atmosphere of nitrogen by means of a hot plate. Then, the film was further heated at 350° C. for 30 minutes in an atmosphere of nitrogen by means of a furnace to form an insulation film in which Si—O—Si bond networks were formed in ladder structure and which was finally chiefly composed of SiO and in which nano-pores having distribution characteristics as shown in FIG. 3 , chiefly containing pores of from 0.05 nm or more to 4 nm or less in diameter, were present, having dielectric constant of about 2.3. This film was formed in a thickness of 400 nm as a second insulation layer 608 of the first conductor layer.
[0128] Next, a silicon carbonitride film 609 serving as a third insulation layer of the first conductor layer was formed by CVD in a thickness of 40 nm. This film serves as a first insulation layer of a second conductor layer, and plays a role also as an etch-stop film or Cu-diffusion barrier film when a hole is formed for forming a wiring pattern.
[0129] Next, a hole was formed in the silicon carbonitride film 609 . The hole was formed using a photoresist and by forming a resist pattern by a known technique, followed by dry etching using the resist as a mask and using an etching gas capable of removing the silicon carbonitride film. Here, the hole is in a wiring size of the first conductor layer.
[0130] Next, in the same manner as the formation of the second insulation layer 608 of the first conductor layer, a second insulation layer 610 of a second insulation layer was formed in a thickness of 400 nm; and a silicon carbonitride film 611 serving as a third insulation layer in a thickness of 40 nm.
[0131] Next, a hole was formed in the silicon carbonitride film 611 . Then, using this silicon carbonitride film 611 as a mask, a hole was formed in the insulation film 610 by dry etching using a gas capable of removing the silicon oxide film. Thus, at its lower part, the insulation film 609 was uncovered.
[0132] Subsequently, using the silicon carbonitride film 609 as a mask, a hole was formed in the silicon oxide film 608 through the former's hole. Then, the etching gas was changed for one capable of removing the silicon carbonitride film 607 , and, using the silicon oxide film 608 as a mask, the silicon carbonitride film 607 was removed by dry etching through the former's hole to form a hole extending therethrough to reach the conducting plug 606 . Here, the periphery of the hole of the silicon carbonitride film 609 was also etched to make this hole expand to the same size as the hole of the uppermost silicon carbonitride film 611 . Thus, a wiring trench was formed which extended through the layers to reach the conducting plug 606 .
[0133] Next, a barrier metal layer was formed on the inner surfaces of the wiring trench, and thereafter the wiring trench was filled with Cu by well known plating. As the barrier metal, TiN was used in this Example. Then, any unnecessary Cu film present on the uppermost silicon carbonitride film 611 was removed by chemical mechanical polishing and the surface was cleaned to form a connecting plug and a wiring simultaneously. In this polishing step, the uppermost silicon carbonitride film 611 was not removed by the polishing to leave it. Thus, a dual-damascene structure in which a Cu wiring (inclusive of 520 and 521 ) was formed was produced.
[0134] The above steps were repeated to form a four-layer wiring structure.
[0135] Subsequently, the like steps were repeated to further stack a two-layer wiring structure. Here, insulation layers 617 , 619 and 621 were formed using silicon carbonitride films in a thickness of 40 nm each. Insulation layers 618 and 620 were also formed using silicon carbonitride films in a thickness of 600 nm each. Next, a silicon nitride film 622 was formed as the uppermost layer to produce a multi-layer wiring semiconductor device made up of a six-layer Cu wiring 623 .
[0136] Thus, a high-performance semiconductor device was obtained the dielectric constant of the whole of interconnecting insulation layers of which was lowered in virtue of the use of, as the etch-stop films or Cu-diffusion barrier films, the silicon carbonitride films having lower dielectric constant than silicon nitride films, in virtue of the use of, in the lower-layer part of the multi-layer stacked structure, as the second insulation layers the insulation films having dielectric constant of less than 2.5 and superior film strength and also in virtue of the use of, in the upper-layer part of the multi-layer stacked structure, the fluorine-doped silicon oxide films having smaller dielectric constant than silicon oxide films.
TWENTIETH EXAMPLE
[0137] FIG. 7 is a cross-sectional view of a resin-encapsulated logic semiconductor device which is Twentieth Example of the present invention.
[0138] A logic semiconductor device 701 obtained in Nineteenth Example and held in the state that a polyimide surface protective film 702 was formed except the part of bonding pads was fastened to a lead frame in the step of die-bonding. Thereafter, gold wires 704 were attached from chip's bonding pads to outer leads 706 of the lead frame by means of a wire bonder.
[0139] Next, using a silica-containing biphenyl epoxy type molding resin material, resin encapsulation 703 was so formed as to envelope the logic semiconductor device 701 , the outer leads 706 and so forth. The encapsulation was carried out under conditions of a molding temperature of 180° C. and a molding pressure of 70 kg/cm2, but not limited thereto.
[0140] Finally, the outer leads 706 are bent in a given shape to obtain a finished product of the resin-encapsulated logic semiconductor device.
[0141] The insulation films having small dielectric constant but well having kept the mechanical strength from lowering are used in a part of the interconnecting insulation layers of the resin-encapsulated logic semiconductor device. Hence, a resin-encapsulated product can be obtained without causing any cracks in the interior of the device during resin encapsulation processing, against the stress applied to the logic semiconductor device.
[0142] Needless to say that the same effect as that stated in Nineteenth Example can be exhibited as characteristics of the logic semiconductor device, the further encapsulation with resin enables the device to ensure electric performance and reliability from environment.
TWENTY-FIRST EXAMPLE
[0143] FIG. 8 is a cross-sectional view for illustrating Twenty-first Example, which is a case in which the logic semiconductor device described in Nineteenth Example is used in wafer level chip-size-packaging products.
[0144] On the uppermost layer, silicon nitride film 802 of a logic semiconductor device 801 , a polyimide insulation film 804 is formed in such a shape that bonding pads 803 stand uncovered.
[0145] Next, electrical rewiring interconnection (between the die pad and the solder ball) 805 is formed. In this Example, the electrical rewiring interconnection 805 is one consisting of TiN, Cu and Ni three layers formed by sputtering, where, after their film formation, a wiring pattern has been formed by known photolithography technology.
[0146] A polyimide insulation film 806 is further formed thereon. Extending through this polyimide insulation film 806 , under-bump metal layers 807 are provided which are to make electrical connection in some region of the electrical rewiring interconnection 805 . As the under-bump metal layers 807 , three layers of Cr, Ni and Au are formed. Solder balls 808 are formed on the under-bump metal layers 807 .
[0147] High-speed drivable logic semiconductor devices themselves can be formed on wafers by the method described in Nineteenth Example. Hence, this Example enables materialization of a logic semiconductor packaging device having solder balls in the state of a wafer.
[0148] The use of the interconnecting insulation layers having low dielectric constant has already afforded logic semiconductor devices having higher performance than conventional products. However, when packaged semiconductor products are surface-mounted on printed wiring boards (PWBs), the use of the packaged structure as in this. Example enables high-speed performance of signal transmission between devices and printed wiring boards and enables further development of the performance of the logic semiconductor device.
TWENTY-SECOND EXAMPLE
[0149] FIGS. 9A and 9B are a cross-sectional view ( FIG. 9A ) and a plan view ( FIG. 9B ) for illustrating Twenty-second
EXAMPLE
[0150] On a silicon substrate 901 , semiconductor devices 906 (such as MOS transistors) and semiconductor circuits ( 906 ) containing these devices have been formed. On this substrate 901 , the conductor layers described above have been formed. Then, using a material comprised of conductor wiring constituting the conductor layers, guard ring layers 905 are so provided as to surround the semiconductor devices 906 and the semiconductor circuits ( 906 ) containing these devices. These guard ring layers 905 are provided for the purpose of preventing water content from entering the semiconductor devices 906 and the semiconductor circuits ( 906 ) containing these devices, from the outside. These are formed in the step of forming the conductor wiring.
[0151] Thus, especially when the insulation films having nano-pores are used as the interconnecting insulation layers showing characteristics of low dielectric constant, a semiconductor device can be provided which has solved the problems of permeation, or adsorption, of the water content in the interiors of, or on the inner walls of, the pores, and has been improved in moisture resistance reliability of the semiconductor device itself.
[0152] In the above, the present invention has been described in detail giving Examples. Conditions and so forth for accomplishing the present invention and Examples are by no means limited to those of these Examples.
[0153] As having been described above, in the semiconductor device having multi-layer stacked wirings employing the damascene structure where copper wirings made to have low wiring resistance are buried in interconnecting insulation layers, films having smaller dielectric constant than silicon nitride films are used as etch-stop films or Cu-diffusion barrier films, and also the insulation films in the lower-layer part and upper-layer part of the multi-layer stacked structure are made different. Thus, the high-performance semiconductor device can be obtained which has made the whole device have high mechanical strength and has made the whole of interconnecting insulation layers have low dielectric constant.
[0154] While we have shown and described several embodiments in accordance with our invention, it should be understood that disclosed embodiments are susceptible of changes and modifications without departing from the scope of the invention. Therefore, we do not intend to be bound by the details shown and described herein but intend to cover all such changes and modifications a fall within the ambit of the appended claims. | As etch-stop films or Cu-diffusion barrier films used in insulation films constituting conductor layers of a stacked structure, films having smaller dielectric constant than silicon nitride films are used, and an insulation film at a lower-layer part of the stacked structure is made to have smaller dielectric constant than that at an upper-layer part thereof, and further this insulation film is a silicon oxide (SiO) film and has, in the interior thereof, nano-pores of from 0.05 nm or more to 4 nm or less in diameter as chief construction. This makes it possible to dramatically reduce effective dielectric constant while keeping the mechanical strength of the conductore layers themselves, and can materialize a highly reliable and high-performance semiconductor device having mitigated the wiring delay of signals which pass through wirings. | 7 |
FIELD OF THE INVENTION
The present invention relates generally to waterproof containers and, more particularly, to containers usable over a wide range of environmental conditions.
BACKGROUND OF THE INVENTION
Waterproof equipment bags have been used by special military units for many years to protect equipment, particularly when the equipment is to be submerged or otherwise exposed to moisture. Equipment such as rifles, radios, optical and demolition equipment is typically protected by such bags.
These prior art bags, which typically comprise a zippered pouch of waterproof material, often leak and subject the equipment therein to damage. Furthermore, such bags, even when not leaking, are often inadequate to protect the equipment when the bag is subjected to significant depths, e.g., one hundred feet, as the bags have no means of relieving the external pressure applied to the bags and therefore burst.
Additionally, the waterproof bags which are used by the military in marine operations are often inadequate for use at high altitudes, as they have no means of equalizing pressure on the inside and outside of the bags as the atmospheric pressure decreases. This deficiency can also lead to bursting of the bags.
A waterproof container which includes a provision for venting the pressure in the interior of the container in response to external pressure would find great utility for not only military applications, but also for commercial and sporting applications such as protecting camera equipment. It also would be desirable in any such container to have the container collapse around the equipment in the container under the force of external pressure and to eliminate any vacuum established by such collapsing prior to the opening of the container.
Accordingly, it is the principal object of the present invention to completely and effectively seal equipment containers against water and moisture.
It is another object of the present invention to vent the interior pressure of the container out of the container in response to changes in environmental pressure.
Yet another object is to eliminate any vacuum established in the container after the air in the interior thereof has been discharged.
SUMMARY OF THE INVENTION
The present invention, in a broad aspect, provides a self-venting waterproof container. The container includes upper and lower waterproof body portions. A seal arrangement effects a seal between the body portions. A latch attaches the body portions together. A pressure relief valve discharges pressure within the container when there is a differential in the pressure of the environment surrounding the container and the interior of the container. A vacuum relief valve eliminates, when opened, any vacuum which has been established within the container.
The upper and lower body portions can be made of collapsible waterproof material. The sealing apparatus can include rigid rims attached to the edges of the upper and lower body portions with the second rim adapted to engage the first rim, and with an elastic gasket disposed between the two rims. A plurality of toggle latches about the periphery of the rims can draw the body portions together to allow the sealing mechanism to effect a seal between the body portions. The pressure relief valve can be an automatic valve, and the vacuum relief valve can be a manually operable valve.
Other objects, features, and advantages of the present invention will become apparent from a consideration of the following detailed description and from the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a self-venting waterproof container according to the present invention;
FIG. 2 is a cross-sectional view of the invention of FIG. 1, taken through the plane II--II;
FIG. 3 is a detailed cross-sectional view of the mating surfaces of the container of the present invention, when the container is assembled, taken through the plane III--III of FIG. 2; and
FIG. 4 is a view similar to FIG. 3 showing the mating surfaces when the container is disassembled.
DETAILED DESCRIPTION
Referring more particularly to the drawings, FIG. 1 shows a perspective view of a self-venting waterproof container 10 according to the present invention. The container 10 includes an upper body portion 12 and a lower body portion 14. These body portions may be of rubberized fabric material, molded rubber, or any other waterproof material. As contemplated by this invention, the material of which the upper and lower body portions 12 and 14 is constructed is a collapsible waterproof fabric. Furthermore, these upper and lower body portions 12 and 14 can be made in a wide range of sizes and shapes to protect a wide range of equipment such as rifles, radios, optical, and demolition equipment. The rectangular shape shown in the figures is for purposes of illustration only.
A seal is effected between the upper body portion 12 and the lower body portion 14 by rims 16 and 18 into which the body portions 12 and 14 are respectively bonded. As shown in FIGS. 2-4, the peripheral edge of the upper body portion 12 is bonded into a groove 40 on the rim 16. Likewise, the peripheral edge of the lower body portion 14 is bonded into a groove 42 on the lower rim 18. The bonding may be done by a variety of means known in the art such as gluing.
Each of the rims 16 and 18 is of a rigid material such as extended aluminum of rigid plastic and encircles the peripheral edges of the upper and lower body portions. Additionally, the upper rim 16 is provided with a channel 36 which is adapted to engage a flange 38 projecting upwardly from the lower rim 18. The channel 36 also has positioned therein an elastic gasket 20, which can be an o-ring. Accordingly, when the container is assembled, the flange 38 enters the channel 36 and bears against the gasket 20, thereby effecting a waterproof seal between the upper and lower body portions 12 and 14.
The upper body portion 12 is attached to the lower body portion 14 through the provision of a plurality of latches 26 which are attached to the upper rim 16 for engagement with the lower rim 18. As shown in the figures, four such latches 26 are used, two on each side of the container. The latches 26 shown in the figures are of the "toggle" variety and engage the edge of the lower rim 14. Reinforcing elements 28 are attached to the rim 14 to strengthen it in the areas where the attachment is to be made. While toggle latches have been shown in the figures and while the latches have been shown attached to the upper rim 16, it is to be understood that this arrangement is for purposes of illustration only and that other types of latches attaching the upper body portion 12 to the lower body portion 14 (or vice-versa) are within the scope of the present invention.
As particularly contemplated by the present invention, the container 10 includes a pressure relief valve 22 and a vacuum relief valve 24. The pressure relief valve 22 may be any conventional pressure valve as known in the art and in a prototype of the invention, a Halkey-Roberts Corp. Model 780-RPA-0.2 valve was used. The primary requirement of the valve 22 is that it only allows air to flow from within the bag to the environment surrounding the bag. The pressure valve 22 is positioned so as to communicate between the interior of the container and the environment surrounding the container. The pressure valve 22 is used to relieve the pressure in the interior of the container which will occur whenever a pressure differential exists across the container 10. Thus, for example, when the container is submerged and the bag is made of a collapsible waterproof fabric, the water pressure will increase on the device as it is brought deeper. As a result, the container 10 will collapse around the equipment stored therein and the air in the interior of the container 10 will be forced out of the container through the pressure relief valve 22 under the force of the water.
Conversely, if the container is brought high into the atmosphere such that the ambient pressure inside of the container exceeds that of the outside environment, the pressure relief valve 22 will allow air to escape from the interior of the container until a pressure equilibrium is obtained between the air within the container and the environment surrounding the container. As is apparent from the foregoing, the pressure relief valve 22 functions automatically to eliminate pressure differentials across the container 10.
Working in conjunction with the pressure relief valve 22 is the vacuum relief valve 24. As shown more particularly in FIG. 2, the valve 24 is a manual valve which comprises a screw 30 threadingly engaging a pair of nuts 32 and 34 on opposite sides of the upper body portion 12. This particular positioning of the vacuum relief valve 24 is for purposes of illustration only as the valve 24 will operate effectively regardless of where positioned on the container 10.
The purpose of the valve 24 is to eliminate the vacuum created within the container 10 after it has been collapsed under the force of external pressure. For example, after the container 10 is submerged and the force of the water on the container forces the air in the interior of the container out of the container through the pressure valve 22, a near-vacuum exists in the interior of the container 10. As a result, it would be quite difficult to disassemble the upper body portion 12 from the lower body portion 14 even after the latches 26 have been released as the vacuum would pull the upper and lower body portions 12 and 14 together. By unscrewing the screw 30 from the nuts 32 and 34, air is allowed to enter into the interior of the container 12 and thereby equalize the pressure between the interior of the container 10 and the atmosphere so as to allow easy disassembly of the container 10. It is to be understood that while a screw and nut arrangement has been shown, other means of relieving a vacuum created in the interior of the container 10 may be satisfactorily employed and fall within the scope of the present invention.
As seen from the foregoing, the present invention provides a simple and effective waterproof container which is responsive to changes in environmental pressure and which can be made in a variety of shapes for use with equipment of various shapes and sizes. It overcomes many of the deficiencies of the prior art and meets the stringent requirements of military use.
In the foregoing description of the present invention, a preferred embodiment of the invention has been disclosed. It is to be understood that other mechanical and design variations are within the scope of the present invention, some of which have been set forth above. Accordingly, the invention is not limited to the particular arrangement which has been illustrated and described in detail herein. | A self-venting waterproof container includes upper and lower waterproof body portions along with a sealing mechanism to effect a seal therebetween. A pressure relief valve provides venting communication between the interior of the container and the environment in which the container is used when there is a differential in environmental pressure and the pressure in the interior of the container. A vacuum relief valve eliminates, when opened, any vacuum existing in the interior of the container. Deformable material used for the body portions allows the container to collapse around the equipment therein under environmental pressure. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The subject application claims the benefit of priority to U.S. Application Ser. No. 60/687,647, filed on Jun. 3, 2005, which is incorporated by reference herein in its entirety. The subject application is a continuation of U.S. application Ser. No. 11/448,167, filed Jun. 5, 2006, now U.S. Pat. No. 8,329,397, which claims the benefit of priority to U.S. Application Ser. No. 60/687,647, filed on Jun. 3, 2005, which are incorporated by reference herein in their entirety. Any disclaimer that may have occurred during the prosecution of the above-referenced applications is hereby expressly rescinded, and reconsideration of all relevant art is respectfully requested.
FIELD OF THE INVENTION
This invention relates to the detection and quantitation of target nucleic acids in a heterogeneous mixture in a Sample and the methods of use thereof. The detection system includes a chemiluminescent molecule, a chemiluminescent substrate, a dye that is light responsive when intercalated into nucleic acid and a nucleic acid target. The method requires that a specific three-dimensional structure (i.e. Dye intercalated into nucleic acid) be created for energy to be accepted by the dye and that the energy donor (Chemiluminescent Molecule) be proximal to this structure. This invention is useful in any application where detection of a specific nucleic acid sequence is desirable, or where the detection of enzymes that modify nucleic acids is desirable such as diagnostics, research uses and industrial applications.
BACKGROUND OF THE INVENTION
Nucleic acids are measured to identify molecules of a specific target nucleic acid sequence in a population of heterogeneous nucleic acids, DNA or RNA, or to measure products of reactions where nucleic acids, DNA or RNA, are modified. Such measurements are generally permutations of the following procedures:
a. where the starting nucleic acid is RNA, conversion to DNA is accomplished by a reverse transcription reaction. The oligonucleotide primers for the reverse transcription reaction may be specific for the target sequence or may be general for conversion of all RNA sequences to DNA;
b. amplification of the target nucleic acid by target sequence specific reactions. These include polymerase chain reaction (PCR) with sequence specific primers, and primer extension reactions again with a target sequence specific oligonucleotide primer. Rolling circle amplification of DNA has also been used to amplify specific DNA sequences;
c. physical separation of the heterogeneous nucleic acids. Such physical separations include but are not limited to size fractionation and affinity separation when amplified nucleic acids are produced with derivatized substrates including but not limited to biotinylated deoxyribonucleotide triphosphates;
d. labeling of the nucleic acid. As mentioned in c. above, amplified nucleic acids may be labeled using either derivatized deoxyribonucleotide triphosphates or derivatized oligonucleotide (RNA or DNA) primers; and
e. detection of the nucleic acids. Nucleic acids can be detected either through the labeling moiety, or by physical separation followed by detection with nucleic acid specific dyes.
One of the more common methods for the quantitative detection of target sequences is the sequence specific amplification of the target sequence(s) by PCR, either from DNA or from cDNA after reverse transcription, physical separation by gel or capillary electrophoresis, and detection by fluorescent labeling (e.g. of dsDNA by ethidium bromide or by use of fluorescently labeled primers in the amplification). Another common technique for the quantitative detection of target sequence(s) involves “real time” PCR.
PCR technology is widely used to aid in quantitating DNA because the amplification of the target sequence allows for greater sensitivity of detection than could otherwise be achieved. The point at which the fluorescent signal is measured in order to calculate the initial template quantity can either be at the end of the reaction (endpoint QPCR) or while the amplification is still progressing (real-time QPCR). The more sensitive and reproducible method of real-time QPCR measures the fluorescence at each cycle as the amplification progresses.
The reporter molecule used in real-time QPCR reactions can be (1) a sequence-specific probe composed of an oligonucleotide labeled with a fluorescent dye plus a quencher or (2) a non specific DNA binding dye that fluoresces when bound to double stranded DNA.
Both of these techniques, and others not described in detail, require instrumentation either for physical separation or detection. The requirement for instrumentation and/or separation technologies with their attendant sample handling limits the use of quantitative and qualitative target sequence detection. Accordingly, there is a need for methods of detecting and measuring nucleic acids that do not require expensive, delicate instrumentation either for sample separation or for detection. Such measurements include but are not limited to the identification of molecules of a specific nucleic acid sequence as well as the detection of nucleic acids that are the product of nucleic acid modifying reactions. Nucleic acid modifying reactions include but are not limited to polymerization reactions, ligation reactions, nuclease reactions and recombination reactions.
Fluorescent Intercalating Nucleic Acid Dyes
A common method for the detection of nucleic acids is by staining them with fluorescing intercalating dyes. These dyes have several unique features that make them especially useful: 1) They have a high molar absorptivity; 2) Very low intrinsic fluorescence: 3) Large fluorescent enhancements upon binding to nucleic acids; and 4) Moderate to high affinity for nucleic acids, with little or no staining to other biopolymers. Intercalating nucleic acid stains have fluorescence excitations and emissions that span the visible-light spectrum from blue to near-infrared with additional absorption peaks in the UV, making them compatible with many different types of instrumentation. These dyes are excited with an extrinsic light source that has a spectrum that overlaps with the maximally excitation wavelength of the intercalated dye. They may be used to image both RNA and DNA. Some commonly used dyes are listed below.
Dye Name Ex/Em* Application Ethidium Bromide 300/600 Quantitation and Detection of dsDNA Ethidium Bromide 510/620 Quantitation and Detection of Homodimer-1 dsDNA PICOGREEN ® 502/523 dsDNA Quantitation Reagent OLIGREEN ® 498/518 Quantitation and Detection of Quantitation Reagent ssDNA and oligonucleotides RIBOGREEN ® 500/520 Quantitation and Detection of RNA Quantitation Reagent SYBR GOLD ® stain 495/537 Quantitation and Detection of single- or double-stranded DNA or RNA post-electrophoresis SYBR GREEN I ® stain 494/521 Quantitation and Detection of double-stranded DNA and oligonucleotides post-electrophoresis Also useful for real-time PCR assays SYBR GREEN ® stain 492/513 Sensitive stain for RNA and single-stranded DNA post-electrophoresis SYBR SAFE ® stain 502/530 Sensitive DNA gel stain with significantly reduced mutagenicity SYBR DX DNA BLOT ® 475/499 Sensitive stain for DNA stain *Excitation (Ex) and emission (Em) maxima are the wavelength, in nanometers, (nm) of light that maximally excites the intercalated dye and the wavelength of light that is maximally emitted when the dye fluoresces, respectively.
Resonance Energy Transfer
Energy may be donated to nucleic acid intercalated dye either by photons or by resonance energy transfer. The principle of energy transfer between two molecules can be exploited as a means to provide information about relative changes in their proximity and orientation to one another. Resonance Energy Transfer (RET) is the transfer of excited state energy from a donor to an acceptor molecule. Förster resonance energy transfer (FRET) is a distance-dependent interaction between the electronic excited states of two dye molecules in which excitation is transferred from a donor molecule to an acceptor molecule without emission of a photon. This can only occur if the absorption spectrum of acceptor molecule overlaps with the emission spectrum of the donor. Förster determined that the degree of resonance energy transfer between the energy donor and energy acceptor is inversely proportional to the distance between the two molecules to the sixth power. In the case of FRET, an external light source of specific wavelength is used to excite the donor molecule.
Bioluminescent Resonance Energy Transfer (BRET) uses biological molecules such as a luciferase as the donor molecule. Depending on the species of origin, luciferases that use coelenterazine as a substrate generate blue light in the range of 450 to 500 nm. When a suitable acceptor is in close proximity, the blue light energy is captured by RET. The acceptor molecules are generally a class of proteins that have evolved the ability to be excited by blue light and then fluoresce in longer wavelengths typically with maximal spectral emissions above 500 nm. In both FRET and BRET the molecules of interest may be either covalently or non-covalently linked or brought in to proximity by conformational change or by spatial migration or by an alteration in their relative orientations to one another. For instance, the two molecules may be conjugated to two separate proteins of interest. They may then be brought into proximity by their affinity for one another or their affinity for a third molecule. They may also be attached to a protein of interest and then brought closer due to a conformational change within the protein of interest. Generally the two molecules must be within 100 Å of one another for resonance energy transfer to occur and changes as little as 1-2 Å may be detected. Luciferases that have been used in BRET include those from the firefly, Renilla reniformis and Gaussia princeps . A commonly used fluorescent protein is the green fluorescent protein (GFP) from Aequorea victoria . BRET is generally used to measure the degree of affinity or degree of conformational change between two protein domains either covalently or non-covalently linked.
SUMMARY OF THE INVENTION
The present invention functions to bring a Chemiluminescent Molecule within close proximity to dye stained target nucleic acids or the products of nucleic acid modifying reactions. The ability of the energy to be accepted by the dye is conditional. It is necessary for the dye to be intercalated into nucleic acid and that the energy donor be in close proximity. The method requires that a specific three-dimensional structure (i.e. Dye intercalated into nucleic acid that is contacted to a Chemiluminescent Molecule) be created for energy to be accepted by the dye and that the energy donor be proximal to this structure.
Specific advantages of the present invention include the following. The invention is rapid, and does not require any wash steps, which is significant as would be recognized by one of skill in the art. It does not require radioactivity nor does it require a laser for activating nucleic acid conjugated fluorophores. The signal from the emitted light in the reactions may be integrated over minutes as opposed to milliseconds as is the case with laser activated fluorophores.
A unique aspect of this method is that of Proximity. Direct contact of the Chemiluminescent Molecule to the nucleic acid allows for the sensitive detection of a change in the mass of stainable nucleic acid (Example 3). The amount of fluorescence from nucleic acid that has been stained with an intercalating dye is directly proportional to the amount of nucleic acid present. Any condition in which the total mass of nucleic acid that is attached to the Chemiluminescent Molecule is increased or decreased will result in an increase or decrease of fluorescence by an activated intercalating dye.
The Chemiluminescent Molecule does not simply act as an indicator of the presence of contact of a probe to a fluorophore. It indicates that duplex nucleic acid is present by virtue of its illumination of dye bound that can only act as an energy acceptor when bound to duplex. In the case of detecting nucleic acids of specific sequence it adds a level of stringency. A positive signal requires both that the indicator molecule (i.e. the Chemiluminescent Molecule) be associated with the target sequence and also that nucleic acid be present. In other words it demands that a specific three-dimensional structure be created for energy to be accepted by the dye and that the energy donor be a part and thus proximal to this structure. This will significantly reduce the background noise in the system for which it is being applied.
The presence of the target nucleic acid is conveyed when the light emitting Chemiluminescent Molecule is brought into close proximity in the presence of fluorescent intercalated dye. The light emitted by the intercalated dye is proportional to the amount of stainable nucleic acid that is in close proximity to the Chemiluminescent Molecule.
The present invention relates to a general detection system for nucleic acids and methods of use thereof. The preferred system comprises four reagents: 1) a Chemiluminescent Molecule, 2) a Chemiluminescent Substrate, 3) an Intercalating Dye and 4) Nucleic Acid. These reagents are contacted with a Sample and can detect a change in the mass of stainable nucleic acid caused hybridization to complementary nucleic acids or by nucleic acid modifying reactions. The nucleic acids in a Sample can be either unamplified or the result of amplification reactions.
A Chemiluminescent Probe may be made by covalently or non-covalently attaching the Chemiluminescent Molecule to a single stranded nucleic acid probe capable of hybridizing to complementary single stranded nucleic acid in the Sample. The target nucleic acid being probed in the Sample may be in solution phase with Chemiluminescent Probe in solution phase being added. The nucleic acid being probed in the Sample may be immobilized on a solid support with the Chemiluminescent Probe in solution phase being added. The Chemiluminescent Probe may be immobilized on a solid support with the nucleic acid being probed in the Sample in solution phase being added. The Chemiluminescent Probe and the nucleic acid being probed in the Sample may be immobilized.
The Intercalating Dye is added to the Sample containing double stranded nucleic acid and a Chemiluminescent Molecule or Probe and it intercalates into the double stranded nucleic acid regions in the Sample. The Chemiluminescent Substrate is added to the Sample and is activated by the Chemiluminescent Molecule. The interaction of the Chemiluminescent Molecule and Chemiluminescent Substrate produces energy that in turn excites the Intercalating Dye at the Intercalating Dye Excitation Wavelength and the Intercalating Dye emits light at the Intercalating Dye Emission Wavelength. The light emitted at the Intercalating Dye Emission Wavelength is measured (with or without appropriate emission filters) and it is possible to determine the presence and quantitate the amount of target nucleic acid in the Sample. Using a filter one may discriminate longer wavelength light emitted by the fluorescing intercalated dye from the shorter wavelength light emitted by the Chemiluminescent Molecule. This discrimination may also be accomplished by incorporating into the Chemiluminescent Reaction non-intercalating, non-fluorescing dyes that absorb light emitted at the wavelengths produced by the Chemiluminescent Molecule but not that of the fluorescent intercalated dye. This general method is depicted in FIG. 1 .
In one non-limiting embodiment, the Sample contains single stranded genomic DNA suspected of containing integrated HIV proviral sequence. The Chemiluminescent Molecule is Gaussia princeps luciferase (gluc) and it is covalently attached to a ssDNA probe that is complementary to a region of the HIV envelope gene. The Intercalating Dye is PICOGREEN® and the Chemiluminescent Substrate is coelenterazine. The Sample DNA is denatured to generate single strands and then the probe covalently attached to Gaussia luciferase is added to the Sample and hybridizes to its complement. The PICOGREEN® is added to Sample and intercalates into the dsDNA region resulting from the probe hybridization. The coelenterazine is added to the Sample and causes the Gaussia luciferase to emit blue light with a spectrum peak at 480 nm. The emitted blue light causes any intercalated PICOGREEN® in close proximity to be excited, since its peak excitation wavelength is 502 nm. The PICOGREEN® then emits a bright green spectrum of light with a peak at 523 nm that can be easily measured with a charged coupling device (CCD) camera that is equipped with a filter that significantly diminishes wavelengths below 500 nm.
An additional nonlimiting disclosure of the present invention would create a proximity assay by bringing a chemiluminescent molecule into close proximity with nucleic acid polymers incorporating fluorescently labeled nucleotides, or nucleotide analogs that fluoresce, in place of the intercalating dyes of the present invention. U.S. Pat. Nos. 6,451,536 and 6,960,436 describe the use of fluorescent nucleotides to detect and measure DNA samples without the component of proximity that embodies the present invention. These above referenced patents are hereby incorporated in their entirety by reference.
This invention is useful in any application where detection of the presence or absence of DNA is desirable, such as diagnostics, research uses and industrial applications. This method is particularly well suited to detecting DNA in Samples either in solution or in a microarray format. This method is also well suited to detecting the products of enzymatic activities that create or modify nucleic acid samples such as polymerases, nucleases, recombinases and ligases as well detecting inhibitors of these activities. The present invention also encompasses methods of use of the above-described system.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 depicts an embodiment having Probe directly attached to Chemiluminescent Molecule and Sample where both are unattached to a Solid Support.
FIG. 2 depicts an embodiment having Probe directly attached to a Chemiluminescent Molecule and Sample is immobilized on Solid Support.
FIG. 3 depicts an embodiment having Probe indirectly attached to a Chemiluminescent Molecule and Sample both are unattached to a Solid Support.
FIG. 4 depicts an embodiment having Probe indirectly attached to a Chemiluminescent Molecule and Sample is immobilized on Solid Support.
FIG. 5A shows the CCD camera images for reactions described in Example 1 when SYBR GREEN I® is the Intercalating Dye. In this experiment the luciferase and SYBR GREEN I® concentrations are held constant while the DNA concentration is varied.
FIG. 5B shows the data generated in Example 1 presented as relative intensity per spot.
FIG. 6A shows the CCD camera images for reactions described in Example 2 when SYBR GREEN I® is the Intercalating Dye. In this experiment the luciferase and DNA concentrations are held constant while the SYBR GREEN I® concentration is varied.
FIG. 6B shows the data generated in Example 1 presented as relative intensity per spot when SYBR GREEN I® is the Intercalating Dye.
FIG. 7A shows a schematic diagram of the experiment described in Example 3 where the biotinylated gluc is brought into close proximity to the biotinylated DNA duplex by a streptavidin intermediate in the presence of SYBR GREEN I®.
FIG. 7B shows the data generated in Example 3 where the biotinylated gluc is brought into close proximity to the biotinylated DNA duplex by a streptavidin intermediate in the presence of SYBR Green I®.
FIG. 7C shows the data generated in Example 3 presented as relative intensity per spot when SYBR GREEN I® is the Intercalating Dye.
FIG. 8 shows the predicted data from a hypothetical assay using the Gaussia princeps luciferase conjugated to a DNA oligomer probe to quantitate DNA of a unique sequence in mixed sample.
DETAILED DESCRIPTION OF THE INVENTION
The invention provides a general method for detecting the presence or absence of nucleic acid in a Sample. In a preferred embodiment, the system comprises four reagents: 1) a Chemiluminescent Molecule, 2) a Chemiluminescent Substrate, 3) an Intercalating Dye and 4) Nucleic Acids. The following terms are intended to have the following general meanings as they are used herein as would be readily understood by one of skill in the art.
A. Definitions
“Bioluminescent Molecule” means any biological molecule involved in a chemiluminescent reaction. The reaction may be either catalytic or stoichiometric.
“Chemiluminescent Emission Spectrum” means the range of photon wavelengths emitted by the Chemiluminescent Molecule. The spectrum is frequently defined by the wavelength of highest intensity from a chemiluminescent reaction.
“Chemiluminescent Probe” means an olio- or poly-nucleotide probe molecule with a coupled Chemiluminescent Molecule. The Chemiluminescent Molecule may be coupled covalently or through non-covalent interaction, either before or after modification of the Probe by target nucleic acid.
“Chemiluminescent Substrate” means a reactant that interacts with the Chemiluminescent Molecule to produce a photon/light.
“Chemiluminescent Molecule” means any molecule that takes part in any chemiluminescent reaction; this includes but is not limited to a bioluminescent molecule.
Various Chemiluminescent Molecules and their respective Chemiluminescent Substrates include but are not limited to:
i) Luciferases that utilize coelenterazine as a Substrate including luciferases from the organisms Gaussia princeps, Periphylla periphylla, Renilla mulleri and Aequorea Victori. ii) Firefly luciferase that utilizes firefly luciferin as Substrate. iii) Alkaline phosphatase that utilizes DuoLuX™ Chemiluminescent/Fluorescent Substrate for phosphatase. iv) Horseradish peroxidase that utilizes DuoLuX™ Chemiluminescent/Fluorescent Substrate for peroxidase
“Chemiluminescent Reaction” means any chemical reaction that produces a photon without an input photon. The reactants may act either catalytically or stoichiometrically. In the case of a catalytic reaction, the catalyst converts a substrate(s) into a product(s) with the concomitant release of a photon. In the case of a stoichiometric reaction, two or more reactants are converted to product(s) and a photon.
“Complementary base pairs” means the purine and pyrimidine bases that pair to form stable hydrogen bonds between two single strand nucleic acid molecules. The usual base pairs are adenine and thymidine, guanine and cytosine, and adenine and uracil. Other base pairs include derivatized variants of these bases, including but not limited to methylated bases, and other purines and pyrimidines including but not limited to inosine.
“Double strand nucleic acid” means two single strand nucleic acid molecules that are non-covalently associated by hydrogen bonding of complementary bases on the two molecules.
“Excitation” means the transfer of energy from a Chemiluminescent Molecule to the Intercalating Dye. Energy transfer from a luminescent molecule to the Intercalating Dye may be through the donation of photons or through Resonance Energy Transfer (RET).
“Hybridization” means the association reaction between two nucleic acid molecules through complementary base pairs to form a double strand nucleic acid.
“Intercalating Dye” means a molecule that binds to double stranded or single stranded nucleic acids between adjacent base pairs. Further, upon intercalation the dye undergoes a change in its electronic configuration such that its absorption and/or emission spectra change. The dye has a very low intrinsic fluorescence when not bound to nucleic acids. The dye has a very large enhancement of fluorescence upon binding to nucleic acids with increases in quantum yields to as high as 0.9. The dye has a very high affinity for nucleic acids and little or no staining of other biopolymers.
“Intercalating Dye Excitation Spectrum” means the range of wavelengths of energy that excites an intercalated dye complexed with double stranded or single stranded nucleic acid to produce a photon at its emission spectrum. The Intercalating Dye Excitation Spectrum overlaps with the emission spectrum of the Chemiluminescent Molecule.
“Intercalating Dye Emission Spectrum” means the wavelengths of photons emitted by intercalated dye complexed with double stranded or single stranded nucleic acid when excited by a light source with a spectrum that overlaps with its maximal excitation wavelength.
“Nucleic acid” means an oligomer or polymer of DNA, RNA or a chimera of both. It includes oligomers or polymers of DNA, RNA or chimeras of both into which analogs of nucleotides have been incorporated. It also includes oligomers and polymers of nucleotide analogs, as would be recognized by one of skill in the art. Examples of nucleotide analogs include nucleotides such as Locked Nucleic Acid (LNA) or Peptide Nucleic Acid (PNA) or other nucleotide analogs that are capable of complementary base-pairing with DNA or RNA, or nucleotide analogs that can be incorporated by enzymes that modify DNA such as telomerases, DNA polymerases, DNA repair enzymes, reverse transcriptases, or DNA and RNA ligases, or other DNA modifying enzymes known to those skilled in the art.
“Probe” means any single strand nucleic acid with a defined sequence of purine and pyrimidine bases, including modifications as would be recognized by one of skill in the art.
“Proximity” means the condition in which different molecules are close by virtue of their association in a stable molecular complex as would be appreciated by one of skill in the art. The molecules may be associated through covalent or non-covalent interactions. It is envisioned that the size of such complexes would be at the level seen in most protein/protein, protein/nucleic acid and nucleic acid/nucleic acid complexes. The proximity of the Chemiluminescent Molecule to nucleic acid would preferably be less than 500 Å. The proximity of the Chemiluminescent Molecule to nucleic acid would more preferably be less than 250 Å. The proximity of the Chemiluminescent Molecule to nucleic acid would most preferably be less than 100 Å. The nucleic acid may have a length much greater than 500 Å.
“Sample” means any mixture of molecules collected from solid, solution or gas that may contain nucleic acid or activity that may modify nucleic acid or inhibitors of said activity.
“Single strand nucleic acid” means an oligomer or polymer of repeating units of phosphate and ribose or deoxyribose joined at the 3′ and 5′ positions of the sugar rings together with the purine or pyrimidine bases attached at the position of the ribose or deoxyribose ring.
“Solid support” includes any suitable support for a binding reaction and/or any surface to which molecules may be attached through either covalent or non-covalent bonds. This includes, but is not limited to, membranes, plastics, paramagnetic beads, charged paper, nylon, Langmuir-Blodgett films, functionalized glass, germanium, silicon, PTFE, polystyrene, gallium arsenide, gold and silver. Any other material known in the art that is capable of having functional groups such as amino, carboxyl, thiol or hydroxyl incorporated on its surface, is also contemplated. This includes surfaces with any topology, including, but not limited to, flat surfaces, spherical surfaces, grooved surfaces, and cylindrical surfaces e.g., columns. Probes may be attached to specific locations on the surface of a solid support in an addressable format to form an array, also referred to as a “microarray” or as a “biochip.”
B. The General Method
The Illustrative Embodiments are not Exhaustive of the Embodiments Disclosed in the Present Invention
The preferred embodiment of the present invention comprises four molecules: the first is a Chemiluminescent Molecule, the second is a Chemiluminescent Substrate, the third is an Intercalating Dye and the fourth is Nucleic Acids. The absorption spectrum of the Intercalating Dye overlaps with the emission spectrum of the Chemiluminescent Molecule.
In one embodiment, the Chemiluminescent Molecule is linked, covalently or noncovalently, to a single strand nucleic acid complementary to the target sequence; this will be called the “Probe”. When the “Sample” nucleic acid is denatured and allowed to reanneal in the presence of the “Probe”, the “Probe” and the target sequences in the Sample will form double stranded DNA. This double stranded DNA will in turn associate with the Intercalating Dye. The intercalation of the Intercalating Dye into double stranded will shift the absorption spectrum of the Intercalating Dye to overlap with the emission spectrum of the Chemiluminescent Molecule.
Finally, when the Chemiluminescent Molecule is provided with Chemiluminescent Substrate, it will generate the energy to excite the Intercalated Dye molecules and in turn cause them to emit photons at their emission wavelengths. These photons can be detected/counted. One method to quantitate the light emitted by the dye is to apply a filter that is able to discriminate between light emitted at the lower wavelength from light emitted by the intercalated dye. The efficiency with which energy produced by the Chemiluminescent Molecule is captured by the intercalated Intercalating Dye molecules will depend on the distance between them. The light emitted by the Intercalating Dye is a function the distance between the light source (Chemiluminescent Molecule) and the Intercalating Dye. If Excitation by the Chemiluminescent Molecule occurs by Resonance Energy Transfer then Forster's Equation applies. Forster's Equation states that the transfer of excitation energy between the donor (Chemiluminescent Molecule such as luciferase) and acceptor (Intercalating Dye such as PICOGREEN®) drops off as the 6 th power of the distance between the two.
An advantage of the present invention is that no light source aside from the Chemiluminescent Molecule is necessary for detection. Further, the association of the Chemiluminescent Probe with double strand DNA can be measured without physical separation of the target from other double strand nucleic acid, as only double strand DNA with intercalated Intercalating Dye by close physical association with the Chemiluminescent Probe will produce signal over background. This aspect of the invention alleviates the need for washes, a significant advantage as would be recognized by one with skill in the art. Any detector that can discriminate between the shorter and longer spectra wavelengths can be utilized in this assay system. These include, but are not limited to luminometers, fluorimeters, and CCD cameras equipped with a filter to remove shorter wavelengths in the range of that emitted by the Chemiluminescent Molecule.
C. Embodiment Having Probe Directly Labeled with Chemiluminescent Molecule and Sample in Solution
FIG. 1 is a schematic representation of a Chemiluminescent Probe being used to quantitate nucleic acid of specific sequence in solution phase. Here the Chemiluminescent Molecule is a luciferase. The luciferase is covalently attached to a ssDNA probe. This Bioluminescent Probe is added to a sample containing target sequence nucleic acid in solution and a nucleic acid stain. Coelenterazine is then added to activate the luciferase. The luciferase excites the nucleic acid intercalated stain that in turn emits a spectrum of light with a maximal wavelength of 520 nm. Light with wavelengths below 500 nm is filtered out. Light with wavelengths greater than 500 nm is permitted to pass to a detector.
D. Embodiment Having Probe Directly Labeled with Chemiluminescent Molecule and Sample is Immobilized on Solid Support
FIG. 2 is a schematic representation of a Chemiluminescent Probe being used to quantitate nucleic acid of specific sequence immobilized on a solid support. Here the Chemiluminescent Molecule is a luciferase. The luciferase is covalently attached to a ssDNA probe. This Bioluminescent Probe is then added to the Sample with target nucleic acid immobilized in a solid support. Nucleic acid stain is present in solution in the Sample. Coelenterazine is then added to activate the luciferase. The luciferase excites the nucleic acid intercalated stain that in turn emits a spectrum of light with a maximal wavelength of 520 nm. Light with wavelengths below 500 nm is filtered out. Light with wavelengths greater than 500 nm is permitted to pass to a detector.
E. Embodiment Having Probe Indirectly Labeled with Chemiluminescent Molecule and Sample in Solution
FIG. 3 is a schematic representation of a Chemiluminescent Probe being used to quantitate nucleic of specific sequence in solution phase. Here the Chemiluminescent Molecule is a luciferase. The luciferase is noncovalently conjugated to a biotinylated ssDNA probe through a streptavidin intermediate. Because a single streptavidin molecule may bind four biotin molecules, biotinylated probe DNA, biotinylated luciferase and streptavidin may be mixed in the appropriate ratios to generate a Bioluminescent Probe. The Bioluminescent Probe is added to a sample containing target sequence nucleic acid and a nucleic acid stain. Coelenterazine is added to activate the luciferase. The luciferase then excites the nucleic acid intercalated stain, which in turn emits a spectrum of light with a maximal wavelength of 520 nm. Light with wavelengths below 500 nm is filtered out. Light with wavelengths greater than 500 nm is permitted to pass to a detector.
F. Embodiment Having Probe Indirectly Labeled with Chemiluminescent Molecule and Sample is Immobilized on Solid Support
FIG. 4 is a schematic representation of a Chemiluminescent Probe being used to quantitate nucleic acid of specific sequence immobilized on a solid support. Here the Chemiluminescent Molecule is a luciferase. The luciferase is noncovalently conjugated to a biotinylated ssDNA probe through a streptavidin intermediate. Because a single streptavidin molecule may bind four biotin molecules biotinylated probe DNA, biotinylated luciferase and streptavidin may be mixed in the appropriate ratios to generate a Bioluminescent Probe. This Bioluminescent Probe is then added to the Sample with target nucleic acid immobilized in a solid support. Nucleic acid stain is present in solution in the Sample. Coelenterazine is then added to activate the luciferase. The luciferase excites the nucleic acid intercalated stain, which in turn emits a spectrum of light with a maximal wavelength of 520 nm. Light with wavelengths below 500 nm is filtered out. Light with wavelengths greater than 500 nm is permitted to pass to a detector.
G. Embodiment Having Probe Directly Labeled with Chemiluminescent Molecule, Probe Immobilized on Solid Support and Sample in Solution
H. Uses of the Invention
The invention is a general method for detecting and quantitating target nucleic acid sequences in a heterogeneous mixture of nucleic acids. The detection of nucleic acids is important for many applications, including (but not limited to) diagnostic measurements of nucleic acids in bodily tissues and fluids as would be readily understood by one of skill in the art.
The method serves to monitor the increase or decrease of stainable nuclei acid that is contacted to a Chemiluminescent Molecule. Stainable nucleic acid is any polymer of nucleic acid into which Intercalating Dyes will incorporate as opposed to other biological molecules. Upon binding, these Intercalating Dyes undergo a change in their electronic configuration that makes them fluoresce in the presence of the appropriate excitation wavelength.
This will occur when the mass of stainable nucleic acid that is contacted to the Chemiluminescent molecule is altered. This includes but is not limited to the following:
a. The method measures enzymatic activity that polymerizes the extension of a nascent strand, through the incorporation of nucleotides or nucleotide analogs, of nucleic acid when the extended strand or in the case of duplex its complement are contacted to a Chemiluminescent Molecule and a light responsive intercalating dye is present. Said activity includes but is not limited to RNA polymerases, DNA polymerases and telomerases. The invention also serves to detect inhibitors of the activities thereof; b. The method measures enzymatic activity that degrades nucleic acid when the nucleic acid is contacted to a Chemiluminescent Molecule and a light responsive intercalating dye is present. Said activity includes but is not limited to RNA exonucleases, RNA endonucleases, DNA exonucleases and DNA endonucleases. The invention also serves to detect inhibitors of the activities thereof; c. The method measures enzymatic activity that facilitates the attachment or ligation of separate nucleic acid molecules when one of the nucleic acid molecules is contacted to a Chemiluminescent Molecule and a light responsive intercalating dye is present. Said activity includes but is not limited to DNA ligases. The invention also serves to detect inhibitors of the activities thereof; d. The method measures enzymatic activity that facilitates the recombination of nucleic acid duplex molecules when one of the nucleic acid duplex molecules is contacted to the Chemiluminescent Molecule, a light responsive intercalating dye is present and the mass of the nucleic acid duplex of the recombined product is different than the mass of the nucleic acid duplex of the non-recombined molecule. Said activity includes but is not limited to recombinases and integrases. The invention also serves to detect inhibitors of the activities thereof; e. The method measures enzymatic activity that facilitates the attachment or ligation of duplex nucleic acid molecules to protein molecules when the protein molecules are contacted to or are a Chemiluminescent Molecule and a light responsive intercalating dye is present. The invention also serves to detect inhibitors of the activities thereof.
All patents and publications referred to herein are expressly incorporated by reference in their entirety. The following examples serve to illustrate certain preferred embodiments and aspects of the present invention and are not to be construed as limiting the scope thereof.
EXAMPLES
Example One
Luciferase Activation of DNA Intercalated Dye is Proportional to the DNA Present
Objective:
The objective of this experiment was to determine if the luciferase enzyme of Gaussia princeps (gluc) is sufficient to act as an excitation source for a fluorophore that is staining double stranded (ds) DNA. Specifically, the experiment is intended to determine if the gluc which emits light at a peak of 480 nm can excite a dsDNA intercalated nucleic acid stain with an excitation maximum in the range of 495 nm to 500 nm and an emission maximum of approximately 520 nm. This would be done by detecting light from a gluc, fluorescing nucleic acid stain/dsDNA mixture which has had wavelengths below 500 nm filtered out.
Materials and Methods:
The Gaussia princeps luciferase was from Avidity LLC (Denver, Colo.). The SYBR Green I nucleic acid stain and the linearized dsDNA ladder were obtained from Invitrogen (Carlsbad, Calif.).
The reactions for the detection of dsDNA were as follows. Dilutions of dsDNA, SYBR Green I and gluc were made with 50 mM Tris-HCl pH 7.8, 600 mM NaCl, 1 mM EDTA and 20% BPER II (Pierce Biotechnology, Rockford, Ill.). Coelenterazine (Nanolight International, Pinetop, Calif.) was diluted into PBS, 1 mM EDTA. The final concentration of coelenterazine in the reaction was 50 uM.
Various amounts of dsDNA were preincubated with 0.78 μl of 200× concentrated SYBR Green I in a volume of 50 μl. A 1× concentration is relative and is that defined by the manufacturer as the standard assay amount for DNA detection. Gluc (50 ng) in 5 μl was added to the prestained dsDNA. The luciferase reaction was initiated by the addition of 100 μl of coelenterazine. The reactions were performed in the wells of a white polystyrene 96 multiwell plate (Evergreen Scientific, Los Angeles, Calif.). Light emitted by the reaction was detected with a CCD camera (Raytest, Straubenhardt, Germany). Quantitative analysis of the images obtained with camera was performed with the AIDA software package (Raytest) that was included with the camera. The capture of light from the reaction by the camera began 10 sec after the reaction was initiated. Light was in 1, 15 min increment ( FIG. 5 ). Discrimination between light emitted by the gluc and that emitted by the excited nucleic acid stain/dsDNA duplex was made through the insertion of a filter between the light producing reaction and the aperture of the CCD camera. The aperture setting for the camera was either 0.95 or 11. The filter (Clare Chemical Research, Dolores, Colo.) has been demonstrated to effectively image fluorescing nucleic acid stains that are excited by light wavelengths in the 400 nm to 500 nm range and emit at wavelengths higher than 500 nm when complexed with dsDNA. It does so by significantly filtering out wavelengths lower than 500 nm.
Results:
It was determined that under the conditions used, 50 ng of gluc generated light levels that were within the dynamic range of detection for the CCD camera both with and without the filter. It was also determined that the light generated by this amount of enzyme was as expected, significantly reduced when the filter was used. This level of enzyme was then assayed in the presence of different amounts of dsDNA ( FIG. 5 ). FIG. 5 depicts the light generating reaction performed with 50 ng of gluc and coelenterazine in the presence of SYBR Green 1 and 0 μg, 0.063 μg, 0.125 μg, 0.25 μg, 0.5 μg, 1 μg, and 2 μg of linearized dsDNA (spots 1-7 respectively). Part A shows the CCD camera images for the reactions with filter. Part B shows the same data as relative intensity per spot.
In this experiment it was clearly shown that when both the luciferase enzyme and nucleic acid stain were held constant and the amount of dsDNA was increased, the light produced at longer wavelengths increased proportionally. This demonstrates the ability of gluc to act as an intrinsic light source to activate nucleic acid intercalated dye.
Example 2
Luciferase Activation of a DNA Intercalated Dye is Proportional to the Amount of Dye Present
Objective:
The objective of this experiment was to determine if the luciferase enzyme of Gaussia princeps (gluc) is sufficient to act as an excitation source for a fluorophore that is staining double stranded (ds) DNA. Specifically, the experiment is intended to determine if the gluc which emits light at a peak of 480 nm can excite a dsDNA intercalated nucleic acid stain with an excitation maximum in the range of 495 nm to 500 nm and an emission maximum of approximately 520 nm. This would be done by detecting light from a gluc, fluorescing nucleic acid stain/dsDNA mixture which has had wavelengths below 500 nm filtered out.
Materials and Methods:
The reactions were performed with the same reagents and under the same conditions as described in Example 1. However, in this experiment the concentrations of dsDNA and gluc are held constant and the concentration of SYBR Green I is varied ( FIG. 6 ).
dsDNA (2 ug) was preincubated with SYBR Green I in a volume of 50 μl to final concentrations of 0×, 0.16×, 0.3×, 0.63×, 1.3×, 2.5×, 5×, and 10×. Gluc (50 ng) in 5 μl was added to the prestained dsDNA. The luciferase reaction was initiated by the addition of 100 μl coelenterazine.
The amount of light emitted over 500 nm in each reaction was determined as described in Example 1. The same reactions were also performed in the absence of dsDNA (−dsDNA).
Results:
It was determined that under the conditions used, 50 ng of gluc generated light levels that were within the dynamic range of detection for the CCD camera both with and without the filter. It was also determined that the light generated by this amount of enzyme was as expected, significantly reduced when the filter was used. This level of enzyme was then assayed in the presence of different amounts of SYBR Green I ( FIG. 6 ). FIG. 6 depicts the light generating reaction performed with 50 ng of gluc and coelenterazine in the presence (+dsDNA) or absence (−dsDNA) of linearized dsDNA and SYBR Green Ito final concentrations of 0×, 0.16×, 0.3×, 0.63×, 1.3×, 2.5×, 5×, and 10× (spots 1-8 respectively). Part A shows the CCD camera images for the reactions with filter. Part B shows the same data as relative intensity per spot.
In this experiment it was clearly shown that when both the luciferase enzyme and dsDNA were held constant and the amount of SYBR Green I was increased, the light produced at longer wavelengths increased proportionally. This demonstrates the ability of gluc to act as an intrinsic light source to activate dsDNA duplex intercalated fluorescing dye.
Example 3
Proximity Dependent Activation of a dsDNA Intercalated Dye
Objective
The purpose of this experiment was to demonstrate the dependence that proximity of the Chemiluminescent Molecule to the nucleic acid intercalated dye has on activation of the dye. In this experiment biotinylated dsDNA target is mixed with biotinylated gluc. In this mixture there is no association of the two species of molecules with one another. Upon addition of increasing amounts of streptavidin the dsDNA and gluc become associated with one another with the streptavidin acting as an intermediate ( FIG. 7A ). This is due to the tight non-covalent binding of the biotin moieties on the dsDNA and gluc to the four available biotin-binding sites on the streptavidin. As the amount of streptavidin increases the greater the number of molecules of dsDNA that are placed in close proximity to the gluc molecules also increases. If the activation of the intercalated dye is dependent on the close proximity of the gluc to the dye then the amount of fluorescence at longer wavelengths should increase as the amount of streptavidin increases.
Materials and Methods
The reactions were performed with the same reagents and under the same conditions as described in Example 1. However, in this experiment the dsDNA used was made by annealing two complementary synthetic (Sigma-Genosys, The Woodlands, Tex.) oligonucleotides of DNA 85 and 95 nucleotides in length. One of the oligomers (95 nucleotides) was biotinylated at the 5′ end. Streptavidin was from Pierce Biotechnology (Rockford, Ill.).
dsDNA (2.5 pmole of biotinylated 5′ end per reaction) was preincubated with 0.78 μl of 200×SYBR Green I in a volume of 50 μl. Gluc (50 ng) in 5 μl was added to the prestained dsDNA. Streptavidin in various amounts in 5 μl ddH20 was added to this mix. The mix was incubated 15 min with gentle shaking at room temperature. The luciferase reaction was initiated by the addition of 100 μl of coelenterazine. The amount of light emitted over 500 nm in each reaction was determined as described in Example 1 ( FIG. 7B , FIG. 7C ).
Results
FIG. 7 depicts the light generating reaction performed with 50 ng of biotinylated gluc and coelenterazine in the presence of PicoGreen dye. The DNA target for each reaction was at concentration of 2.5 pmole per biotinylated end per reaction. Streptavidin was present at 0.013 pmole, 0.026 pmole, 0.05 pmole, 0.1 pmole, 0.2 pmole, 0.42, 0.84 pmole (spots 1-8 respectively). Part A shows a schematic diagram of the experimental design. Part B shows the CCD camera images for the reactions with filter. Part C shows the CCD camera images for each reaction assessed as relative intensity per spot.
In this experiment it was shown that the amount of light that can pass through the filter to the CCD camera is directly proportional to the amount of streptavidin that is added. All other components, luciferase, intercalating dye, dsDNA, and coelenterazine are the same in each reaction. The streptavidin serves to bring the Chemiluminescent Molecule (gluc), and stained nucleic acid into a single complex in close proximity to one another. As more streptavidin is added more of the complex is created. The increase in complex is directly proportional the amount of longer wavelength light.
Example 4
FIG. 8 depicts a hypothetical experiment representing a further application of the method. Each data point represents the intensity of a light emitting reaction with the amount of single stranded DNA target increasing in each reaction going from left to right. Gluc/DNA probe, PICOGREEN® and coelenterazine are held constant. Reactions are with either a) Probe with sequence complementary to the target DNA or b) Probe with sequence not complementary to the target DNA. | This invention relates to the detection and quantitation of target nucleic acids in a heterogeneous mixture in a sample and the methods of use thereof. The detection system includes a chemiluminescent molecule, a chemiluminescent substrate, a dye that is light responsive when intercalated into nucleic acids and nucleic acids. This invention is useful in any application where detection of a specific nucleic acid sequence is desirable, or where the detection of enzymes that modify nucleic acids is desirable such as diagnostics, research uses and industrial applications. | 2 |
This is a division of Ser. No. 09/556,426, filed Apr. 24, 2000, now U.S. Pat. No. 6,435,200.
BACKGROUND OF THE INVENTION
The invention relates to a device and a process for liquid treatment of a defined section of wafer-shaped article, a section near the edge, especially of a wafer.
The reason for treatment of a defined section of wafer-shaped article near the edge, especially of a wafer, will be described below.
A wafer, for example a silicon wafer, can for example have a silicon dioxide coating on all sides. For subsequent processes (if for example a layer of gold or a layer of polysilicon (polycrystalline silicon) is to be applied), it can be necessary to remove the existing coating from the wafer at least in the edge area of the main surface, but optionally also in the area of its peripheral surface and/or the second main surface. This is done by etching processes which can be divided mainly into dry etching processes and wet etching processes.
Another application is the cleaning of wafers. Here it can be necessary to clean a wafer at least in the edge area of a main surface, but optionally also in the area of its peripheral surface and/or the second main surface, i.e. to remove particles and/or other contamination. This is done by wet cleaning processes.
The invention is aimed at wet etching and wet cleaning (combined under the concept of liquid treatment). In doing so the surface area of the wafer to be treated is wetted with the treatment liquid and the layer which is to be removed or the impurities are carried off.
A device for executing this liquid treatment is described for example in U.S. Pat. No. 4,903,717. In this device the wafer-shaped article (wafer) is mounted on a spin chuck. The treatment liquid, for example, an etching liquid, is applied to the wafer surface to be treated, the liquid is distributed as a result of the rotational motion of the wafer over its surface and is flung off laterally over the edge of the wafer.
To prevent the treatment liquid from reaching the surface which is not be to treated in an uncontrolled manner, in U.S. Pat. No. 4,903,717 a chuck is proposed which flushes the surface which faces the chuck and which is not to be treated with a gas. In doing so the gas emerges between the wafer edge and the chuck.
JP 09-181026 A describes a chuck for semiconductor wafers which outside of an annular nozzle has a special shape, for example an annular step which falls away to the outside or a bevelling of its edge. In addition, a suction opening is proposed. This shaping of the intake opening is designed to influence (reduce) the flow velocity in the edge area. This is intended to serve such that the treatment liquid which has been applied from overhead flows beyond the edge of the wafer onto the side facing the chuck and treats the edge area there.
Regardless of whether a means to hold the wafer-shaped article (chuck) is used as claimed in U.S. Pat. No. 4,903,717 or JP 09-181026 A, an edge area of 1.5 mm (measured from the outer edge of the wafer) at most can be treated on the main surface facing the chuck. The liquid afterwards flows back in the direction of the wafer edge and is flung off by it.
SUMMARY OF THE INVENTION
Accordingly the object of the invention is to demonstrate one possibility for treating a defined, edge-side area with a liquid on one surface of a wafer-shaped article and it is also to be possible to treat an edge area of more than 2 mm (measured from the outside edge of the wafer).
Accordingly, the invention in its general embodiment proposes a device for liquid treatment of a defined section of a wafer-shaped article, especially a wafer, near the edge, with a means for holding the wafer-shaped article, with a gas feed means for at least partial gas flushing of the surface of the wafer-shaped article which faces the means, in which on the peripheral side there is a gas guide device which routes most of the flushing gas in the edge area of the wafer-shaped article away from the latter.
The holding means (chuck) is used to hold the wafer for this purpose. Here holding can be done using a vacuum or the wafer floats on an air cushion and is prevented from sliding off sideways by lateral guide elements.
The wafer can also be held by the gas which flows past on the bottom of the wafer forming a negative pressure (also called the Bernoulli effect) by which the wafer experiences a force in the direction of the chuck. The wafer is touched by an elevated part of the chuck within the gas feed device, by which the wafer is prevented from sliding off sideways.
Via the gas feed line the gas can be routed onto the bottom (the surface which faces the chuck) of the wafer-shaped article (wafer) in order to prevent the liquid from reaching this bottom and thus executing unwanted treatment. The gas used for this purpose should be inert to the surface onto which it is flowing; for example, nitrogen or extremely pure air are suited.
The gas feed means can consist of one or more nozzles or an annular nozzle. These nozzles should be attached symmetrically to the center of the chuck in order to enable uniform gas flow over the entire periphery.
The gas guide device is used to route the gas which flows from the middle part of the chuck in the direction of the edge of the wafer away from the edge area. The gas now flows past the side of the gas guide device which faces away from the wafer-shaped article. The farther inside (towards the center of the chuck) this gas guide device is attached, the larger the edge area is at this point.
Since in the section of the bottom of the wafer near the edge essentially gas can no longer flow to the outside, in treatment with the liquid the latter can flow around the wafer edge onto the bottom and thus can wet the section of the wafer bottom near the edge.
The advantage of the invention over the prior art is that the size of the section near the edge can be any size desired by means of suitable selection of the gas guide device.
The gas stream which flows past the gap between the gas guide device and the wafer can produce a negative pressure within the gap by suitable shaping of the gas guide, by which in addition in the edge area the gas flows from the vicinity of the wafer edge to the inside. During liquid treatment the liquid is thus sucked into the edge area.
In one embodiment the gas guide device has the shape of a ring. This ring can be attached to the base body of the chuck using for example three or more spacers. But it can also be machined out of the base body by corresponding milling.
The ring in one embodiment has an inside diameter which is smaller than the outside diameter of the wafer-shaped article and an outside diameter which is at least the same size as the outside diameter of the wafer-shaped article.
In this way the liquid which flows around the peripheral-side edge of the wafer-shaped article (around the wafer edge) can be captured by the ring and delivered to the inside.
The gas guide device can also be formed by an annular groove which is concentric to the periphery of the means and from which the gas is discharged to the outside. This can be ensured by simple holes which lead to the outside from the bottom of the groove in the base body of the chuck.
In another embodiment the gas guide device on its inner periphery has a sharp edge (edge angle less than 60°). In this way almost all the gas can be routed away in the edge area from the wafer.
In one embodiment the part of the means which is located between the gas feed means and the gas guide device (base body) is located at a greater distance to the wafer-shaped article (wafer) than the gas guide device to the wafer-shaped article. In this way more gas can flow between the wafer and this part (base body) than between the wafer and the gas guide device. Most of the gas on the side of the gas guide device facing away from the wafer must therefore flow past this device.
Advantageously the gas guide device is configured such that if there is a wafer-shaped article (wafer) on the chuck the gas guide device does not touch the wafer-shaped article (wafer), i.e. a gap remains between the wafer and the ring.
This gap between the gas guide device and the wafer-shaped article in one embodiment is 0.05 to 1 mm, advantageously 0.1 to 0.5 mm. In this way, between the wafer and the gas guide device a type of capillary forms, from which the liquid which has flowed around the wafer edge is sucked. The inside diameter of the surface which faces the gas guide device and which is wetted by the liquid is smaller than the inside diameter of the annular surface of the gas guide device.
It is advantageous if the surface of the gas guide device facing the wafer-shaped article is parallel to the main surfaces of the wafer-shaped article. The gap between the wafer-shaped article (wafer) and the gas guide device is thus the same size in the entire edge area.
One embodiment calls for the chuck being able to be caused to rotate. This is advantageous, even if not necessary, since the treatment liquid can be flung off both from the chuck and also the wafer edge. If the chuck is not in rotation during liquid treatment, the liquid is entrained or blown off by the gas flow.
Another part of the invention is a process for liquid treatment of a defined area of a wafer-shaped article, especially of a wafer, near the edge. In this process the liquid is applied to a first surface facing the liquid source. The liquid flows essentially radially to the outside to the peripheral-side edge of the wafer-shaped article (wafer edge) and around this edge onto the second surface which faces away from the liquid source. The liquid wets a defined section near the edge on the second surface and is thereupon removed from the wafer-shaped article.
The advantage over the prior art is that in this process the part of the liquid flow which reaches the section of the second surface near the edge also flows on the second surface in a stipulated direction (originating from the edge (wafer edge) in the direction of the wafer middle) and need not flow back again to the edge. Rather the liquid is removed from the inside edge of the section near the edge. This can take place for example with a device as claimed in the invention.
In one embodiment of the process the edge area is chosen to be larger than 2 mm.
In another embodiment of the process the wafer-shaped article during liquid treatment rotates around its axis, by which the treatment liquid is flung off the edge of the wafer-shaped article or the wafer edge.
Advantageously the rotational velocity is at least 100/min in order to effectively fling off the liquid.
BRIEF DESCRIPTION OF THE DRAWINGS
Other details, features and advantages of the invention follow from the description below for the embodiments of the invention which are shown in the drawings.
FIG. 1 schematically shows an axial section of the means (chuck 1 ) including a wafer which is located on it.
FIGS. 2 and 3 schematically show an axial section of the edge area of the chuck. Gas routing is apparent in it. Moreover FIG. 3 shows the motion of the liquid during treatment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The chuck 1 consists essentially of three parts ( 2 , 3 , 4 ), the base body 3 , the cover 2 and the gas guide device 4 . The base body 3 is made annular and is joined to a hollow shaft (not shown) which on the one hand can cause the chuck to rotate (shown by the arrow R) and on the other hand can supply the gas feed means ( 5 , 6 ) with gas G.
The cover 2 is inserted into the base body and is joined to it (not shown) such that between the cover 2 and the base body 3 an annular gas channel 5 is formed which on the top (the side facing the wafer) discharges into an annular gap, the annular nozzle 6 . The diameter of the annular nozzle 6 is smaller than the inside diameter of the gas guide device 4 .
This chuck works according to the “Bernoulli principle”. Outside the annular nozzle 6 (in area 7 ) a gas cushion is formed on which the wafer floats. The wafer is prevented from sliding off sideways by guide elements which are attached on the peripheral side (pins 25 ) and the wafer is entrained by them when the chuck rotates around the axis A. The pins can be moved to rest against the edge of the wafer (compare U.S. Pat. No. 4,903,717).
The gas guide device 4 has the shape of a ring and is attached on the base body 3 on the top (the side facing the wafer) using a plurality of spacers 21 which are distributed regularly on the periphery. The ring 4 has an inside diameter which is smaller than the outside diameter of the wafer W and an outside diameter which is larger than the outside diameter of the wafer W.
The surface 14 of the gas guide device facing the wafer W is a flat annular surface which is parallel to the main surfaces of the wafer. Between the surface 14 and the surface of the wafer facing the chuck, when the wafer is located on the chuck, an annular gap 10 is formed. The depth of the gap c ( FIG. 3 ) corresponds to the difference of the outside radius of the wafer W and the inside radius of the gas guide device 4 . The width a ( FIG. 2 ) is formed by the distance from the surface 14 to the wafer surface facing the chuck.
Between the gas guide device 4 and the base body 3 an annular gas discharge channel 8 is formed into which the gas is discharged by the gas guide device 4 . The total cross section of the gap 10 is much smaller than that of the gas discharge channel 8 , by which the channel can discharge most of the gas.
In the area 7 between the wafer W and the base body 3 or between the annular nozzle 6 and the gas guide device 4 the gas flows directly along the wafer surface facing the chuck. The narrowest cross section in this area is located between the surface 13 (the surface of the base body 3 facing the wafer) and the wafer and is shown in FIG. 2 by b. The distance b of the base body 3 to the wafer is larger than the distance a of the gas guide device to the wafer. The surface 12 of the cover 3 facing the wafer is located essentially in the same plane as the surface 13 of the base body.
If the wafer is located on the chuck, it is held suspended by the gas cushion in area 7 , its touching neither the cover 2 nor the gas guide device 4 . The gas escapes from the annular nozzle 6 (gas flow G 1 ) and is discharged via the gas discharge channel 8 (gas flow G 2 ). A small amount of gas can escape via the gap 10 , but a negative pressure is probably produced by the gas flow G 2 , by which even gas from the vicinity is intaken via the gap 10 and is entrained by the gas flow G 2 .
During liquid treatment the liquid is applied to the surface facing the chuck 1 , the liquid then flows in the direction of the wafer edge (liquid flow F) and around the wafer edge E. When the wafer rotates some of the liquid can be flung off directly from the wafer edge (not shown). Then the liquid flow is divided into two flows F 1 and F 2 . The liquid flow F 1 flows away from the wafer.
The liquid flow F 2 flows into the gap 10 and thus wets the bottom of the wafer. F 2 wets the edge area of this surface somewhat farther than the gas guide device extends to the inside. Therefore the wetted area d is somewhat larger than the depth of the gap c. Here the liquid flow F 2 is deflected by the gas flow G 2 around the inner edge of the gas guide device and the liquid flow F 2 and the gas flow G 2 leave the chuck jointly via the gas discharge channel. | A device for liquid treatment of a defined area of a wafer-shaped article, especially of a wafer, near the edge, in which the liquid is applied to a first surface, flows essentially radially to the outside to the peripheral-side edge of the wafer-shaped article and around this edge onto the second surface, the liquid wetting a defined section near the edge on the second surface and thereupon being removed from the wafer-shaped article. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to a rip fence used with a worktable of a cutting machine, such as table saw.
[0003] 2. Description of the Related Art
[0004] FIG. 1 shows a conventional rip fence 2 installed on the worktable 1 a of a table saw 1 . The rip fence 2 can be moved on the top surface of the worktable 1 a to the desired position and then locked. The rip fence 2 comprises a fence body 2 a approximately equal to the width of the worktable la, a fence adjusting handle 2 b pivoted to one end of the fence body 2 a, a front clamp 2 c pivoted to the front end of the fence body 2 a corresponding to the front side of the worktable 1 a, a rear clamp 2 d pivoted to the rear end of the fence body 2 a corresponding to the rear side of the worktable 1 a, and a linking mechanism (not shown) connecting the front clamp 2 c and the rear clamp 2 d to the fence adjusting handle 2 b. The fence adjusting handle 2 b is turnable relative to the fence body 2 a between the pressed position as shown in FIG. 1 where the front clamp 2 c and the rear clamp 2 d are respectively clamped on the front and rear sides of the worktable 1 a to lock the fence body 2 a to the worktable 1 a, and the lifted position as shown in FIG. 2 , where the front clamp 2 c and the rear clamp 2 d are respectively disengaged from the worktable 1 a for enabling the user to move the fence body 2 a on the top surface of the worktable 1 a to the desired position. This structure of rip fence 2 is functional, however it is not safe in use. During cutting operation, the fence adjusting handle 2 b may be lifted accidentally to unlock the fence body 2 a. If the user keeps operating the sawing machine at this time, an accident may occur.
SUMMARY OF THE INVENTION
[0005] The present invention has been accomplished under the circumstances in view. It is the primary objective of the present invention to provide a rip fence, which is easy to adjust and safe in use.
[0006] To achieve this objective of the present invention, the rip fence, which is movable on and lockable to a worktable of a machine, comprises a main body having a front end and a rear end, an adjusting handle pivoted to the front end of the main body, a trigger pivoted to the adjusting handle and turnable between a first position and a second position, a clamp provided at the rear end of the main body and having a stop portion stoppable at a rear end of the worktable, and a link coupled between the adjusting handle and the clamp. The trigger has a stop portion, which is stoppable against a front end of the worktable when the trigger is moved to the first position and is away from the front end of the worktable when the trigger is moved to the second position, and a pressable portion which can be pressed by a user to move the trigger from the first position to the second position. When the trigger is positioned at the second position and the adjusting handle is lifted relative to the main body, the link will be forced to move the clamp away from the worktable, for enabling the rip fence to be moved on the worktable to a desired position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a schematic drawing showing a rip fence locked to the worktable of a sawing machine according to the prior art.
[0008] FIG. 2 is similar to FIG. 2 but showing the unlocked status of the rip fence.
[0009] FIG. 3 is a schematic drawing showing a rip fence installed on the worktable of a sawing machine according to the present invention.
[0010] FIG. 4 is an exploded view of the rip fence according to the present invention.
[0011] FIG. 5 is a sectional view showing the rip fence locked to the worktable according to the present invention.
[0012] FIG. 6 is similar to FIG. 5 but showing the trigger pressed.
[0013] FIG. 7 is similar to FIG. 6 but showing the adjusting handle lifted, the rip fence unlocked.
DETAILED DESCRIPTION OF THE INVENTION
[0014] As shown in FIGS. 3-5 , a rip fence 100 is slidably mounted on the top of the worktable 200 of a cutting machine (for example, a table saw). The rip fence 100 comprises a main body 10 , an adjusting handle 18 , a trigger 28 , a spring member 32 , a clamp 36 , and a link 40 .
[0015] The main body 10 has a front end 10 a and a rear end 10 b, and is comprised of a channel bar 12 , a guiding seat 14 and a stop plate 16 . The guiding seat 14 is provided at one end of the channel bar 12 . The stop plate 16 is set near the rear end 10 b of the main body 10 , having a through hole 16 a. The guiding seat 14 has a transverse hole 14 a, and a window and index structure (not shown) through which the user can see the indication of the graduations on the worktable 200 indicative to the length of the workpiece under cutting.
[0016] The adjusting handle 18 is comprised of a grip 20 and a coupling frame 22 . The grip 20 is orthopedically engineered for comfortable gripping with the hand, having a mounting hole 20 a. The coupling frame 22 is an open frame having a first through hole 22 a, a second through hole 22 b, and a third through hole 22 c. As shown in FIGS. 4 and 5 , a pivot pin 24 is fastened to the transverse hole 14 a of the guiding seat 14 and the first through hole 22 a of the coupling frame 22 to pivotally couple the adjusting handle 18 to the guiding seat 14 of the main body 10 , so that the adjusting handle 18 is turnable about the pivot pin 24 relative to the guiding seat 14 between two reversed directions. Further, a pin 26 is inserted through the second through hole 22 b of the coupling frame 22 and connected firmly with the coupling frame 22 .
[0017] The trigger 28 has a hooked stop portion 28 a, a pressable portion 28 b, a through hole 28 c, and an arched guiding hole 28 d. A pivot pin 30 is fastened to the third through hole 22 c of the coupling frame 22 and the through hole 28 c of the trigger 28 to pivotally secure the trigger 28 to the coupling frame 22 of the adjusting handle 18 , for enabling the trigger 28 to be turned relative to the adjusting handle 18 between a first position where the hooked stop portion 28 a is stopped against the worktable 200 , and a second position where the hooked stop portion 28 a is kept away from the worktable 200 . The pressable portion 28 b is maintained extended out of the coupling frame 22 for pressing by the finger of a user for moving the trigger 28 from the first position to the second position.
[0018] The spring member 32 is a coil spring mounted on the pivot pin 30 , having one end stopped against one side of the coupling frame 22 and the other end stopped against the trigger 28 . The spring member 32 imparts a push force to the trigger 28 to force the hooked stop portion 28 a into contact with the front bottom side of the worktable 200 . Further, a guiding pin 34 is inserted through the mounting hole 20 a of the grip 20 and the arched guiding hole 28 d of the trigger 28 to guide movement of the trigger 28 stably between the first position and the second position.
[0019] The clamp 36 is a plate member provided at the rear end 10 b of the main body 10 , having a through hole 36 a and a stop portion 36 b. Further, a coil spring 38 is stopped between the stop plate 16 and the clamp 36 .
[0020] The link 40 is a rod member longitudinally inserted in proper order through the main body 10 , the through hole 16 a of the stop plate 16 , the spring 38 , and the through hole 36 a of the clamp 36 , having one end terminating in a hook 40 a, which is hooked on the pin 26 , and the other end terminating in a screw rod 40 b, which is screwed up with a nut 42 .
[0021] The positioning of the rip fence 100 on the worktable 200 and its adjustment are outlined hereinafter with reference to FIGS. 5-7 .
[0022] FIG. 5 shows the rip fence 100 locked to the worktable 200 where the adjusting handle 18 is kept suspended downwards, the hooked stop portion 28 a of the trigger 28 is forced by the spring member 32 into contact with the front bottom side of the worktable 200 , and the clamp 36 is dragged by the link 40 to keep the stop portion 36 b stopped at the rear side of the worktable 200 .
[0023] When wishing to unlock the rip fence 100 from the worktable 200 , press the pressable portion of the trigger 28 to move the hooked stop portion 28 a away from the worktable 200 (see FIG. 6 ), and then turn the adjusting handle 18 upwards to change the position of the pin 26 , as shown in FIG. 7 . At this time, the spring 38 pushes the clamp 36 outwards from the worktable 200 , and therefore the rip fence 100 is unlocked and can be moved on the worktable 200 to a desired position. After the rip fence 100 has been moved on the worktable 200 to the desired position, turn the adjusting handle 18 downwards to lock the rip fence 100 to the worktable 200 again, as shown in FIG. 5 .
[0024] As indicated above, when the user touches the adjusting handle 18 accidentally without pressing the trigger 28 during cutting operation, the rip fence 100 is maintained locked to the worktable 200 . Therefore, the trigger 28 ensures safety use of the rip fence 100 .
[0025] Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims. | A rip fence for movable and positionable use on a worktable of a cutting machine includes an adjusting handle for control locking of the fence to the worktable, and a trigger, which keeps the fence locked to the worktable when it is not pressed and, which enables the user to unlock the fence from the worktable by operating the adjusting handle when it is pressed. | 8 |
FIELD OF THE INVENTION
[0001] The present invention concerns a trolley for the use in an autoclave. The trolley is designed to receive a number of packages for sterilization or retorting.
[0002] The trolley may be used for any type of product to be treated in an autoclave. However, the trolley has been especially developed to receive fibre-based cartons enclosing a food product or the like. The cartons and the content are sterilized simultaneously in the autoclave.
BACKGROUND OF THE INVENTION
[0003] It is previously known to place packages to be treated in an autoclave on a tray or the like.
[0004] Previously tin canes containing food products or the like has been sterilized simultaneously in an autoclave. When cartons have been used the cartons has usually been sterilized separately and the content separately and then the sterilized cartons has been filled with the sterilized food products. A new fibre-based carton has been developed, which can be sterilized in an autoclave when filled with a food product or the like. Thus, both the cartoon and the food product are sterilized simultaneously in the same way as tin cans have been sterilized previously.
SUMMARY OF THE INVENTION
[0005] One object of the present invention is that the trolley should not hinder that the heat is evenly distributed in the autoclave.
[0006] A further object is to have a simple loading and unloading of the packages to be retorted.
[0007] Thus, the trolley has been developed to both make it possible to have an even heating throughout the autoclave and to have a simple loading and unloading of packages to be treated. This is done by the use of profiles placed on the trolley to receive the packages. The profiles are formed and positioned in such a way that at least four sides of each package are exposed to the steam of the autoclave.
[0008] Each profile is U-shaped having a great number of openings. The sides of the profile are angled in relation to the bottom part of the profile. The trolley is furnished with wheels or the like adapted to the autoclave in use in order to be easily moved into and out of the autoclave.
[0009] Further objects and advantages of the present invention will be obvious for a person skilled in the art when reading the detailed description below of preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] An embodiment of the invention will be more closely described below in way of an example and by reference to the enclosed drawings, in which,
[0011] [0011]FIG. 1 is a front view of a trolley according to the invention,
[0012] [0012]FIG. 2 is a side view of the trolley of FIG. 1,
[0013] [0013]FIG. 3 is a plan view of one profile, and
[0014] [0014]FIG. 4 is a principal view showing the positions of the profiles.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0015] The trolley 1 of the FIGS. 1 and 2 has at least four vertical bars 2 . The vertical bars 2 are placed at the corners of the trolley 1 . On two opposite sides of the trolley 1 horizontal bars 13 go between the top of the vertical bars 2 . Furthermore, a number of horizontal bars 3 are placed between the vertical bars 2 at the ends of the trolley 1 . On these horizontal bars 3 a number of shelves or profiles 7 are placed. The trolley 1 has a bottom frame 4 , normally furnished with four wheels 5 , one in each corner. An angled bottom part 12 of the bottom frame 4 or the vertical bars 2 are adapted to support the trolley 1 outside the autoclave. Thus the trolley 1 normally rests on these bottom parts 12 . In the autoclave the wheels 5 of the trolley 1 rests on rails and thus the trolley 1 is moved into and out of the autoclave by means of the wheels 5 on the rails. Outside the autoclave the trolley 1 is normally moved by means of conveyors, whereby the trolley 1 rests on the angled bottom parts 12 of the vertical bars 2 or the bottom frame 4 . A person skilled in the art realizes that the trolley may have any form as long as the profiles are given the desired form and the trolley may be received by the autoclave.
[0016] The profiles 7 are to receive packages 6 that are to be treated in an autoclave and have a general U-shape. The sides 8 of the profiles 7 show an angle a in relation to a vertical plane or the side of a package 6 . The profiles 7 , including the sides 8 , are furnished with a large number of holes 9 . When designing the profiles 7 the number and size of the holes 9 is a compromise between the necessary strength of the profiles 7 and the wish that as much as possible of the packages 6 should be exposed to the steam of the autoclave.
[0017] The profiles 7 are positioned to give a distance 10 between the packages 6 in adjacent profiles 7 . They also give a distance 11 in height between packages 6 placed above each other. The packages 6 in each profile 7 are normally placed abutting each other. The profiles 7 are placed parallel and with a small distance adjacent each other. The distance between the profiles 7 is normally only about 1 to 3 mm. The packages are normally placed lying down on one side to maximize the size of the surfaces of the package 6 exposed to the steam.
[0018] The holes 9 of the profiles 7 are optimised to distribute the steam and water of the autoclave in the best way. It is important that the steam and thus the heat of the autoclave is distributed evenly. Due to the holes 9 of the profiles 7 at least four sides of each package 6 are reach directly by the steam. The steam is normally distributed from the sides of the autoclave and a fan is provided to distribute the heat evenly throughout the autoclave.
[0019] The sides 8 of the profiles are angled a to facilitate loading and unloading of the packages 6 and partly to collect the cooling water. By the angled sides 8 the steam and cooling water of the autoclave will reach the packages 6 more easily. The cooling water is normally distributed from the top of the autoclave. The angle α should be 15° or more in relation to a vertical plane. Normally the angle α is between 15° and 30° and preferably between 15° and 20°. The sides 8 of the profiles 7 have a height of at least about 10 mm depending on the size of the packages 6 .
[0020] The holes 9 of the profile 7 should have a diameter of about 3 to 15 mm and preferably of 4 to 10 mm. If the holes 9 have a diameter less than about 4 mm the water may be trapped in the holes 9 by means of capillary force. If the holes 9 have a diameter bigger than about 10 to 15 mm the pressure of the autoclave may deform the packages 6 . The maximal allowable diameter of the holes 9 may vary depending on the packages 6 , the content of the packages 6 and the temperature and pressure of the autoclave. Thus, for some packages 6 a diameter of more than 15 mm may be acceptable. A person skilled in the art realizes that the form and placement of the holes may be varied.
[0021] The size and number of profiles 7 in the trolley are adapted to the size of the packages 6 to be treated.
[0022] The packages 6 are normally pushed in a row into and out of each profile 7 . The packages 6 will slide on the profile 7 . The packages 6 in each profile 7 are placed abutting each other and lying on one side. A stop (not shown) is normally placed at the end of each profile and the row of packages is pushed against said stop.
[0023] In use packages 6 will be slid into each profile 7 until the desired amount of packages 6 are placed on the trolley 1 . The trolley 1 is then moved into the autoclave. In the autoclave the packages 6 are first treated with steam under pressure and then cooled by water. Due to the holes 9 of the profiles 7 and the distance between the profiles 7 the steam will reach at least four sides of each package 6 . After the heat treatment the packages 6 are cooled by means of water. The water is normally delivered at the top of the autoclave and will flow downwards on the trolley 1 . The U-shape of the profiles 7 will collect some of the falling water and lead it towards the packages 6 . The holes 9 of the profiles 7 and the distance between the profiles 7 will let the water trough and guarantee that also the lowermost packages 6 of the trolley 1 are cooled by the water.
[0024] As an alternative (not shown) the profiles 7 may be arranged on plates. Each plate is placed on top of another plate when loaded with packages 6 . To keep a proper distance 11 between the packages the plates are furnished with spacers placed at the corners. The spacers may be integrated with the plates or may be lose spacers placed manually or by a machine between successive layers of plates having profiles 7 and packages 6 . In this embodiment the packages 6 are normally lifted onto the desired positions in the profiles 7 . | The present invention concerns a trolley ( 1 ) for an autoclave. The trolley is furnished with U-shaped profiles ( 7 ) to receive packages ( 6 ), which are to be sterilized in the autoclave simultaneously with their contents. The profiles ( 7 ) have a large number of openings. By the position and the form of the profiles ( 7 ) at least four sides of each package ( 6 ) are reached by steam of the autoclave. The angled sides ( 8 ) of the U-shaped profiles ( 7 ) assists in collecting the cooling water of the autoclave and lead it towards the packages ( 6 ). | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a position-regulating device for working mechanisms of mobile machines and a method of regulating the position of working mechanisms of mobile machines.
2. Discussion of the Prior Art
A micro-mechanical incline sensor, in particular for motor vehicles, is known as such from DE 197 52 439 A1, and has a bearing plate, the inclination of which is determined relative to the horizontal. At least two pressure sensor units are integrated on the bearing plate to determine a pressure applied to the plate at the respective points. An earth plate is connected to the bearing plate via the pressure sensor units. An evaluation unit uses the data produced by the pressure sensor units to determine the inclination of the bearing plate relative to the horizontal. Depending on the inclination of the device in which the inclination sensor is integrated, the earth plate applies a different degree of force to the respective sensor unit. At least two pressure sensors must be provided in order to measure the angle of inclination. In DE 197 52 439 A1, these are provided in the form of piezo-resistive pressure detectors.
A level-regulating device for a quay crane is known from DE 39 38 766 A1. In this case, levelling is regulated using a hydraulic control valve to actuate one or more hydraulic actuators for a part which is to be maintained at a specific level, the part being coupled with another part by which it can be adjusted to any position. To ensure a high degree of operating safety without using expensive electronic systems, the control valve is mechanically linked to and actuated by a pendulum, as its operating mechanism, the position of which is determined by gravity.
When the device is at an incline, the pendulum effects a damped deflection in a fixed direction in space, which is transmitted via the control valve to the hydraulic actuator. In DE 39 38 766 A1, a loading and unloading crane, particularly one which is suitable for loading and discharging ships, fitted with this feature, is set up so that when the crane boom is raised and lowered, a loading and unloading device disposed thereon remains in a fixed position relative to the rest of the structure.
One particular disadvantage of the level-regulating device known from DE 39 38 766 A1 is the one-dimensional orientation. In the embodiment described as an example in the above-mentioned patent specification of providing a levelling means on a loading and unloading crane, preferably used for ships, the device is totally satisfactory but for mobile machinery such as earth moving machines, for example, which preferably have to move around building sites and hence on uneven ground, one-dimensional level correction is not sufficient.
SUMMARY OF THE INVENTION
Accordingly, the objective of the present invention is to propose a device and a method for regulating the position of working mechanisms of mobile machines, by means of which the working mechanisms can be reliably adapted to both more than one direction and to the ground below on which they are travelling, depending on the respective position of the machine, without losing load on uneven terrain.
The invention is based on the knowledge that in preventing load losses, it is not just the orientation of a working mechanism of a mobile machine when it is not moving or when picking up material that is important, but also specifically when transporting the received material in the terrain. Consequently, a device that is to be suitable for this purpose must permit orientation with respect to a defined plane relative to the force of gravity and within a satisfactorily short time. The device proposed by the invention and the corresponding method constitute an arrangement that will enable a position to be corrected relative to a plane perpendicular to the force of gravity and if necessary inverse acceleration.
The possibility of designing the comparator device both as a conventional analogue system and as an integrated circuit is an advantage because it allows the special requirements of individual machines to be met.
The arrangement is easy to set up and can be readily fitted with standard sensors.
The arrangement is suitable for designs operating in one spatial direction and in two spatial directions. Especially with earth-moving machines, it is of advantage to be able to apply a position correction in the longitudinal and transverse directions. In one especially preferred embodiment, natural vibrations and their multiples induced by the control running time are eliminated.
By particular preference, the predetermined angle is adjusted so that the plane defined by the position of the working mechanism is perpendicular to the resultants of gravitational force and inverse acceleration force.
BRIEF DESCRIPTION OF THE DRAWINGS
Examples of preferred embodiments of the device proposed by the invention are illustrated in the drawings and will be explained in more detail below with reference to the drawings. They allow the working mechanism to be positioned so as to prevent load loss, even when the working mechanism is being accelerated, e.g. during travel motion.
Of the drawings:
FIG. 1 is a first circuit diagram of a first embodiment of the device proposed by the invention as a means of controlling and activating hydraulic actuators to regulate the position of displaceable working mechanisms of mobile machines;
FIG. 2 is a second circuit diagram of a second embodiment of the device proposed by the invention;
FIGS. 3A–3B illustrate the main structure of a digital filter unit designed as a 2nd order band-stop filter and the associated amplitude response;
FIGS. 4A–4B provide a simplified diagram of the motion of a mobile work machine on the ground as known from the prior art and how the position-regulating device proposed by the invention is applied with a mobile machine as it moves on the ground;
FIG. 5 is a perspective illustration showing an example of a working mechanism of a mobile machine with the possible pivot directions;
FIG. 6 is a schematic illustration of a mobile machine with the position-regulating device proposed by the invention on uneven terrain; and
FIG. 7 is a sketch illustrating load control making allowance for acceleration.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a first circuit diagram of a first embodiment of the position-regulating device proposed by the invention for working mechanisms of mobile machines. The circuit has a first sensor 1 , which measures a first angle in a first spatial direction, hereafter denoted by x. This first angle will be referred to hereafter as α x . Similarly, a second sensor 2 measures a second angle in a second spatial direction y. The second angle is referred to hereafter as α y . The measured angles α x and α y are compared by means of a first comparator 3 and a second comparator 4 with an angle α x ′ for the spatial direction x and α y ′ for the spatial direction y fixed by an angle detector 5 , which may be 90° respectively, for example. The comparators 3 and 4 form a comparator unit 6 . The angle detector 5 may provide either a fixed, predetermined or manually variable angle α x ′ or α y ′ using manually controlled detector 5 a.
After the first comparator 3 , the signal in x-direction is run through a first band-stop filter 7 whilst the signal in y-direction is run through a second band-stop filter 8 after the second comparator 4 . The purpose of the band-stop filters 7 and 8 is to eliminate the natural vibration f R and optionally its multiples 2 f R , 3 f R , . . . induced in the system by the control running time τ so that the dynamic behaviour of the system remains controllable, avoiding the occurrence of resonances.
Having been run through the band-stop filter 7 , the signal in x-direction is amplified by a first amplifier 9 so as to be able to actuate a first solenoid 10 . The first solenoid 10 is needed to operate a first control valve 11 which in turn actuates a first hydraulic actuator 12 to correct the position in the first spatial direction x. Similarly, after being run through the band-stop filter 8 , the signal in y-direction is amplified by a second amplifier 13 in order to actuate a second solenoid 14 and hence a second control valve 15 . The second control valve 15 operates a second hydraulic actuator 16 . The working mechanism is oriented in the second spatial direction y as a result.
In order to operate the hydraulic actuators 12 and 16 , a hydraulic fluid disposed in a tank 17 is compressed by a pump 18 in a front or rear cylinder chamber of a first cylinder 19 of the first hydraulic actuator 12 and in the front or rear cylinder chamber of a second cylinder 20 of the second hydraulic actuator 16 . Consequently, a first piston 21 and a second piston 22 are subjected to a change of position, which in turn regulates the position of the working mechanism 41 .
The position continues to be regulated until the comparators 3 and 4 detect no difference between the measured angle α x and α y and the pre-set angle α x ′ and α y ′. In terms of amount, the differences α x ′−α x or α y ′−α y will be almost zero or will lie at least below a value which is still tolerable for an angular variance Δα, for example ±3°.
Once this state is reached, there is no further change in the signal at the control valves 11 and 15 , which then switch back into a neutral position without further altering the position of the actuators 12 and 16 as they do so. The system remains in the neutral position until a modified signal arrives from the comparators 3 and 4 again.
FIG. 2 illustrates a second embodiment of a position-regulating device proposed by the invention for working mechanisms of mobile machines. The same reference numbers are used for components described with reference to FIG. 1 and will not be described again below. Whilst the embodiment of FIG. 1 is built using analogue technology, the embodiment illustrated in FIG. 2 is based on digital technology.
The device illustrated in FIG. 2 primarily differs from the device shown in FIG. 1 due to the use of a digital control unit 34 , which assumes the function both of the band-stop filters 7 and 8 and the comparator unit 6 .
Accordingly, the comparator unit 6 is built as follows. The angle α x emitted by the sensor 1 is pre-amplified in a first pre-amplifier 30 and then converted by a first analogue-to-digital converter 32 from an angular value measured in analogue to a digital value that can be processed by a digital control unit 34 . Similarly, the angle α y is amplified by a second pre-amplifier 31 and converted by a second analogue-to-digital converter 33 into a digital value. In order to be able to compare the pre-set angle α x ′ or α y ′ with the angles α x or α y detected by the sensors 1 and 2 , the pre-set angle α x ′ and α y ′ issued by the angle detector 5 is also converted by a third analogue-to-digital converter 35 and applied to the digital control unit 34 , which may be a microprocessor.
In addition to comparing the angular values, the digital control unit 34 also filters the signals. To this end, the filter unit is a digital filter with a band-stop characteristic. As with the embodiment illustrated in FIG. 1 , the band-stop characteristic correspond to the second order digital band-stop filter illustrated as an example of an embodiment in FIGS. 3A and 3B , for example, provided by a corresponding programme in the control unit 34 . The digital control unit 34 has a storage 36 , which, for example, offers the possibility of storing the measured and compared data so that it can be made available for subsequent external additional processing.
The compared signals from the sensors 1 and 2 are converted into analogue signals by a first digital-to-analogue converter 37 and a second digital-to-analogue converter 38 . The analogue signals are amplified by amplifiers 9 and 13 and forwarded to the solenoids 10 and 14 . Similarly to the first embodiment, hydraulic actuators 12 and 16 are actuated by the control valves 11 and 15 , the pump 18 and the tank 17 . They then correct the position of the working mechanism 41 .
FIG. 3A illustrates the operating principle of a second order digital bandpass filter and FIG. 3B the associated frequency response. FIG. 3A shows a digital filter which creates a band-stop by means of various delay elements for delaying the sampling values (denoted by z −1 in FIG. 3A ) and coefficient elements a 0 , a 1 , and a 2 for changing the amplitude of the sampling values, having the resonance frequency f R shown in FIG. 3B . As a result, the natural vibration f R of the system, induced by the control running time τ, and its uneven multiples (3f R , 5f R , etc.) are filtered out. This prevents any build-up in the system. As a result, functioning of the device is highly dynamic on the one hand and extremely accurate on the other. Another digital filter may be provided to filter out the doubled resonance frequency 2f R .
How the invention is applied in one dimension will be explained in more detail with reference to a machine 40 schematically illustrated in FIG. 4 with a bucket as the working mechanism 41 .
FIG. 4A illustrates the existing prior art. When the bucket 41 is in the lower position (left-hand side of the diagram), the bucket 41 is aligned so that an imaginary plane 42 extending across the opening at the top of the bucket 41 is always parallel with the surface of the ground. Standard machines 40 commonly have a lifting mechanism for the working mechanism 41 , which is designed so that the bucket 41 is lifted in such a way that the plane 42 determined by the opening of the bucket 41 always remains parallel with the ground.
As long as the machine 40 is travelling on a flat stretch, there are no inherent problems. However, as soon as the machine 40 starts to move up or, as illustrated in FIG. 4A , down an incline, material 43 is lost because the plane 42 determined by the bucket 41 remains parallel with the ground as before and the material 43 being transported in the bucket 41 falls out with effect from a specific incline. The angle of inclination starting from which the load will be lost depends on the shape of the bucket 41 and how full it is.
A different reference plane 42 ′ for aligning the bucket 41 is proposed for the purposes of the invention, as illustrated in FIG. 4B . As in FIG. 4A , an imaginary plane 42 ′ extending across the top opening of the bucket 41 is defined on the working mechanism 41 of the machine 40 illustrated in FIG. 4B . It is no longer necessarily parallel with the ground but is always oriented almost perpendicular to the direction of gravitation, denoted by the vector g in FIG. 4B . This can be obtained in both the lower and in the upper position of the bucket 41 . The advantage of this is that the bucket 41 proposed by the invention is always additionally controlled when travelling uphill or downhill and when travelling on uneven terrain so that the plane 42 extending through the bucket 41 is always oriented perpendicular to the direction of gravitational acceleration g. This avoids transport losses from the bucket 41 .
The one-dimensional correction to the position of the bucket 41 illustrated in FIG. 4 can also be applied without problem in two directions perpendicular to one another, for example longitudinally and transversely to the direction of displacement.
FIG. 5 provides a schematic illustration of a bucket 41 for this purpose, in perspective. The bucket 41 can be pivoted up and down through the axes A and B parallel with and perpendicular to the direction of displacement, both transversely to the travel direction and in the travel direction. Consequently load losses from the front and to the side of the bucket 41 can be prevented during travel on uneven terrain.
FIG. 6 is a schematic illustration of a machine 40 travelling on uneven terrain, where the position of the working mechanism 41 is again controlled by means of its position relative to gravitation g. In this connection, it is of practical advantage for the angle α between the plane 42 defined by the bucket 41 and the direction of gravitation g to assume a threshold value for the angular variance Δα with effect from which position regulation can be dispensed with. Consequently, a practical balance can be struck between uninterrupted position correction, which requires a lot of energy and can be impractical because of the delay in regulation, and loading loss due to lack of position correction. Resonant rises, which might occur if the control excitation induced by the unevenness of the ground coincides with the resonance frequency f R of the system, can be suppressed by the described filter.
Whilst the plane 42 defined by the orientation of the bucket 41 is perpendicular to the direction of gravitational force g in the embodiment illustrated in FIG. 6 , another improved position correction can be applied if the plane 42 defined by the bucket 41 is not perpendicular to the gravitational force g but is oriented perpendicular to the resultants r of the gravitational force g and the inverses b′ of the acceleration force b. The bucket 41 is illustrated on a larger scale in FIG. 7 . It is assumed that the mobile machine 40 is subject to a delay due to a braking procedure. Consequently, the delaying acceleration force b acts on the bucket 41 . Relative to the reference system of the bucket 41 , an inverse acceleration force b′ acts in the inverse direction to the acceleration force b delaying the bucket 41 due to the mass inertia, and acts on the bulk material introduced into the bucket 41 , i.e. the acceleration force b′ acting on the bulk material in the reference system of the bucket 41 has the same value as the acceleration force b acting on the bucket 41 in the delaying direction but rotated by 180°.
Consequently, the resultant r of the gravitational force g and the inverse acceleration force b′ act on the bulk material disposed in the bucket 41 . It is therefore of advantage if the plane 42 is incorporated in the position regulation proposed by the invention in such a way that the plane 42 is perpendicular to the resultant r. To this end, another measuring system 29 is provided with the embodiments illustrated in FIGS. 1 and 2 for measuring the acceleration or delay of the mobile machine 40 . The acceleration or delay may also be measured separately in the dimensions x and y. Whilst the measuring system 29 for measuring acceleration is connected directly to the angle detector 5 in the embodiment illustrated in FIG. 1 using analogue technology and the pre-set angle α x ′ in the x-direction and the pre-set angle α y ′ in the y-direction of the angle detector 5 are over-controlled, the measuring system 29 for measuring acceleration in the embodiment of FIG. 2 based on digital technology is connected to the control unit 34 via an analogue-to-digital converter 28 , which computes a correction of the pre-set angles α x ′ and α y ′ depending on the measured acceleration.
This additional feature ensures that the position of the bucket or generally the working mechanism 41 is regulated so that bulk material does not fall out even in the event of higher accelerations or delays of the mobile machine 40 .
The invention is not restricted to the embodiments illustrated as examples here but may be applied to any machines using different sensors or filter systems. | The invention relates to a device for controlling the position for work devices ( 41 ) of mobile machines ( 40 ). The inventive device comprises a measuring device ( 1,2 ) for measuring an angle (α) which is formed between a level ( 42 ) that is determined by the position of the work device ( 41 ) and the direction of the gravitational force (g). The inventive device also comprises an angle transmitter ( 5 ) for predetermining an angle (α′) which is formed between a level ( 42 ) that is determined by the position of the work device ( 41 ) and the direction of the gravitational force (g). The inventive device further comprises a controller ( 3, 4, 6–16 ) for controlling the angle (α) between the level ( 42 ) of the work device ( 41 ) and the direction of the gravitational force (g) in such a way that the measured angle (α) matches the predetermined angle (α′). | 4 |
STATEMENT OF GOVERNMENT INTEREST
The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.
BACKGROUND OF THE INVENTION
This invention relates generally to cooling chambers, and, more particularly, to a transmissive Dewar cooling chamber which is capable of mounting semiconductor crystal platelets therein for movement in two dimensions within a semiconductor ring laser
In recent years, the use of semiconductor devices has expanded greatly. An area of particular interest involving semiconductors is the optically pumped semiconductor laser. In fact, recent advances in laser research have led to the development by one of the inventors of optically pumped semiconductor lasers. Of particular interest are such lasers as described in an article by C. B. Roxlo, D. Bebelaar, and M. M. Salour, "Tunable CW bulk semiconductor platelet laser," Applied Physics Letters, Vol. 38, No. 7, April 1, 1981, pp 507-509 and an article by C. B. Roxlo and M. M. Salour, "Synchronously pumped mode-locked CdS platelet laser," Applied Physics Letters, Vol. 38, No. 10, May 15, 1981, pp 738-740.
In order to provide optimal outputs in such semiconductor lasers, the semiconductor platelets must be cooled to liquid nitrogen temperatures or below. This has been accomplished by one of the inventors by providing a uniquely designed Dewar cooling chamber for the above mentioned semiconductor platelet lasers. Such a Dewar cooling chamber is more fully described in an article by C. B. Roxlo and M. M. Salour, "Dewar design for optically pumped semicondcutor lasers," Review of Scientific Instruments, Vol. 53, No. 4, April 1982, pp 458-460 and is also described in U.S. patent application Ser. No. 361,020 filed on Mar. 23, 1982 and now U.S. Pat. No. 4,408,464 issued on Oct. 11, 1983.
With requirements for larger and larger output power much effort has gone into producing an optically pumped semiconductor laser having a ring resonant cavity. An example of such an optically pumped CW semiconductor ring laser can be found in U.S. patent application Ser. No. 552,554 filed together with this patent application by one of the inventors and incorporated herein by reference. The problems encountered in the past with respect to semiconductor lasers become even greater when dealing with the semiconductor ring laser. Because of bidirectional lasing associated with such semiconductor ring lasers, temperature control becomes even more critical. In addition, since tuning of such a laser is highly desirable it must also be possible to provide a temperature control within the cooling chamber. Unfortunately, the type of Dewar cooling system as described in the above-mentioned article in Review of Scientific Instruments and the above-identified U.S. Pat. No. 4,408,464 cannot be incorporated within the semiconductor ring laser. Therefore, without an appropriate cooling chamber for use within such a semiconductor ring laser it is virtually impossible for lasing to take place and for operation of such a laser to be reliable.
Consequently, it becomes essential to provide a mounting arrangement for the semiconductor crystal or crystal platelet within the semiconductor ring laser which not only allows for precise alignment of the crystal but also for accurate temperature control of the crystal, sufficient cooling of the crystal, and extremely tight pump beam focus upon the crystal to take place.
SUMMARY OF THE INVENTION
The present invention overcomes the problems encountered with prior Dewar cooling chambers by providing a transmissive Dewar cooling chamber which is readily adaptable for use within an optically pumped CW semiconductor ring laser.
Making up the transmissive Dewar cooling chamber of this invention is a housing having a pair of optically transparent windows capable of passing both the pump beam and the laser beam therethrough. Also associated with the interior of the housing is a cooling source such as liquid nitrogen as well as a uniquely designed mount for operative connection with the cooling source. In addition, it is essential that the mount incorporate therein a non-reflective, optically transmissive, good heat conductive substrate, preferably made of sapphire, in order to provide effective heat removal to take place from the semiconductor crystal mounted thereon. For maximum heat transfer, a second non-reflective, transmissive heat conductive material may also be placed adjacent the semiconductor crystal within the chamber.
In addition, a mounting arrangement for two dimensional or two directional semiconductor crystal movement in conjunction with the chamber is formed as part of the external configuration of the housing. Focusing and defocusing means, preferably in the form of a pair of microscope objectives, are adjustably incorporated to the outer structure adjacent the transmissive windows of the Dewar cooling chamher in order to enable a pump beam and laser beam to be focused upon the semiconductor crystal held within the housing, and for the ensuing fluorescence to be defocused and collimated thereby, allowing lasing action to continue within the ring-shaped resonant cavity.
Since it is essential in the present invention to substantially reduce the heat which is generated in the semiconductor crystal it is necessary for the space between the housing windows and the sapphire substrate (and any other heat removing material) to be minimal. Therefore, there must be no other elements in the housing interposed within the optical path followed by a laser beam through the semiconductor crystal except for these heat removing elements.
For appropriate temperature control of the semiconductor crystal within the Dewar cooling chamber of this invention, a heat source in the form of a controllable electrical heater element is situated adjacent the crystal mount. By the selective utilization of the heater element it is possible to aid in the tuning of the semiconductor ring laser in which the Dewar cooling chamber of this invention is incorporated.
It is therefore an object of this invention to provide a transmissive Dewar cooling chamber capable of adequately cooling a semiconductor crystal or crystal platelet such that the crystal can be used as a lasing medium within a semiconductor ring laser.
It is another object of this invention to provide a transmissive Dewar cooling chamber which provides for two dimensional movement of the semiconductor within the semiconductor ring laser.
It is still a further object of this invention to provide externally mounted focusing and defocusing elements in order for the cooling chamber to be effectively used within a semiconductor ring laser.
It is still a further object of this invention to provide a transmissive Dewar cooling chamber which is economical to produce and which utilizes conventional, currently available components that lend themselves to standard, mass producing, manufacturing techniques.
For a better understanding of the present invention, together with other and further objects thereof, reference is made to the following description taken in conjunction with the accompanying drawing and its scope will be pointed out in the appended claims.
DETAILED DESCRIPTION OF THE DRAWING
FIG. 1 is a side elevational view of the transmissive Dewar cooling chamber of this invention shown partly in cross section;
FIG. 2 is a cross sectional front view of the transmissive Dewar cooling chamber of this invention taken along line II--II of FIG. 1 and shown partly in cross section;
FIG. 3 is a schematic illustration of the transmissive Dewar cooling chamber of this invention in use within a semiconductor ring laser system; and
FIG. 4 is a side elevational view of an alternate embodiment of the transmissive Dewar cooling chamber of this invention shown partly in cross section.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference is now made to FIGS. 1 and 2 of the drawing which clearly illustrate the transmissive Dewar cooling chamber 10 of this invention. Dewar cooling chamber 10 supports therein a semiconductor crystal or crystal platelet 11 made of any suitable semiconductor material such as cadmium sulfide. Although the primary use of Dewar cooling chamber 10 of the present invention is within a ring laser, it is not limited to a specific type of a ring laser. FIG. 3 of the drawing is representative of an optically pumped CW semiconductor ring laser 12, more fully described in the above-referred to U.S. patent application Ser. No. 552,554 filed herewith, and with which the Dewar cooling chamber 10 of the present invention can be utilized. Since the semiconductor ring laser 12 does not form part of the present invention, it will be described hereinbelow only briefly in order for the operation of the Dewar cooling chamber 10 to be more clearly understood.
Semiconductor ring laser 12 incorporates Dewar cooling chamber 10 within the ring-shaped resonant cavity thereof. A pair of microscope objectives 14 and 16 focus the pump beam 18 onto the semiconductor crystal 11 within chamber 10 as well as focus and defocus the laser beam 20. A series of reflecting elements 22, 24 and 26 are located external of the cooling chamber 10 in optical alignment with each other in order to form the ring-like laser or resonant cavity. One of these reflecting elements 22 is also used in order to output a pair of laser beams 28 and 30 produced by the ring laser 12. A polarizing beam splitter 32 is utilized to direct the pump beam 18 into the resonant cavity of laser 12.
Reference is once again made to FIGS. 1 and 2 of the drawing in order to more fully and clearly describe the cooling chamber 10 of the present invention. More specifically, cooling chamber 10 is made up of a housing 40, preferably in the form of an upper section 42 and a lower section 44, defining therein, respectively, a pair of chambers 43 and 45. The upper section 42 of housing 40 includes therein a suitable cooling reservoir 46 as well as having mount 48 for semiconductor crystal 11 secured thereto. An example of such a coolant reservoir 46 would be one which includes a coolant source 50, for providing liquid nitrogen for example, operably connected thereto. Reservoir 46 is made of a stainless-steel tubing, with the bottom thereof being made of a material having good thermal conductivity such as copper. In so doing the Dewar cooling chamber 10 is able to provide appropriate conductive connection to mount 48. Any suitable vacuum pump 54 can be operably connected to upper section 42 by line 55 in order to create an appropriate vacuum within housing 40.
The other or lower section 44 of housing 12 of cooling chamber 10 is securely affixed to the upper chamber 42 by any conventional securing means (not shown) and a suitable gasket or O-ring seal 56. Located within lower section 46 are a pair of oppositely disposed optically transparent windows 58 and 60, preferably made of glass. Windows 58 and 60 are transmissive at the wavelength of operation of semiconductor ring laser 12 with which the Dewar cooling chamber 10 of this invention is utilized. In order to aid in the transmissivity windows 58 and 60 can be coated with any suitable anti-reflection (AR) coating. Situated within the lower section 46 of housing 42 and juxtaposed windows 58 and 60 is the semiconductor crystal mount 48. As described above, mount 48 is secured at its upper end to the bottom 52 of reservoir 46 by any suitable securing means such as screw 62.
The semiconductor crystal mount 48 is made up of a frame 64 formed of any suitable, excellent heat conducting material such as copper. Frame 64 has a preferably square cutout section 66 having a lip 68 formed therearound. The cutout section 66 is positioned so it is in optical alignment with the windows 58 and 60 of lower section 44. Positioned against lip 68 is a non-reflective, optically transparent or transmissive mounting substrate 70, preferably made of sapphire. Substrate 70 is also transmissive at the wavelength of interest for laser operation. A pair of heat conductive, thermal conductor restraints 72 and 74 are utilized to secure sapphire substrate 70 in place so that the coolant within reservoir 46 is capable of having its lower temperature conducted onto substrate 70 through frame 64. Thin sheets 76 of indium (˜0.2 mm) are inserted between the sapphire substrate 70 and the copper frame 64 as well as between the copper frame 64 and the bottom 52 of the liquid nitrogen reservoir 46 in order to insure good thermal connections therebetween. Further, the bottom 52 of reservoir 46 as well as the copper frame 64 can be gold plated in order to reduce radiation losses.
Crystal 11 is secured to the sapphire substrate 70 by means of using a thin film of low viscosity silicone oil 78 applied upon substrate 70 adjacent crystal 11. Crystal 11 is held in place on substrate 70 by surface tension. The oil layer 78 is often less than 5 micrometers thick and does not crack when cooled.
Adjacent each side of lower section 44 of cooling chamber 10 and external thereto are a pair of stages or mounts 80 and 82, respectively, which enable appropriate focusing and defocusing elements to be secured therein for translational motion in the Z direction. The focusing/defocusing elements are both in the form of conventional microscope objectives 14 and 16 placed in front of and in back of the transparent windows 58 and 60, respectively. By mounting microscope objectives 14 and 16 so as to be movable within mounts or stages 80 and 82, it is possible to move the microscope objectives along the Z axis, thereby focusing the incoming pump beam 18 (as shown in FIG. 3 of the drawing) onto the semiconductor crystal 11 as well as to focus and defocus the intracavity semiconductor laser beam 20. An example of a type of microscope objective which can be utilized with the present invention would be a Leitz EF 10/0.25P microscope objective.
Referring now more specifically to FIG. 2 of the drawing, the entire housing 40 of cooling chamber 10 of the present invention is mounted on a translational mount 84 capable of providing two dimensional movement to housing 40 and thereby crystal 11. This translational movement takes place along the Y axis and X axis and is accomplished by the appropriate adjustment of a pair of micrometer heads 86 and 88, respectively. In this manner, it is possible to position crystal 11 (which is affixed to sapphire substrate 70) in its appropriate relationship with respect to an incoming pump beam 18 or with respect to the laser beam 20 within the semiconductor ring laser 12 as illustrated in FIG. 3 of the drawing.
Also located within the lower section 44 of cooling chamber 10 is a heating element 90, preferably in the form of an electrical heater which can be controlled externally by means of a conventional rheostat or heater control 91 in order to provide accurate temperature control of the environment surrounding crystal 11. This fine or accurate temperature control provides a temperature in the range of approximately 85° K. to 140° K. for crystal 11 and can therefore be utilized in tuning of ring laser 12.
It is has been found, however, that in some instances even greater temperature control and cooling capability for crystal 11 is desired. This can be accomplished with the embodiment of Dewar cooling chamber 100 as set forth in FIG. 4 of the drawing. Therefore, reference is now made to FIG. 4 of the drawing in which the alternate embodiment of the present invention is depicted. Since many of the elements which make up the Dewar cooling chamber 100 set forth in FIG. 4 of the drawing are identical to those elements which make up Dewar cooling chamber 10 illustrated in FIGS. 1 and 2 of the drawing, the same reference numerals will be utilized to identify identical elements in all the Figures of the drawing. Since the majority of such elements are identical, a detailed description of those identical elements will not be set forth hereinbelow. The major difference between the Dewar cooling chamber 100 as depicted in FIG. 4 and that of Dewar cooling chamber 10 resides in an additional cooling or heat conductive medium 102 being introduced between transparent window 58 and crystal 11. This heat conductive medium 102 is in the form of a piece of excellent heat conductive material such as sapphire affixed to frame 64 in the manner described hereinbelow.
Heat conductive material 102 is supported on a frame 104 which is utilized in place of the restraints 72 and 74 shown in FIGS. 1 and 2 of the drawing. By providing a frame 104 of good heat conductive material it is possible to position the second sapphire material 102 in abutting relationship with crystal 11. It is also necessary that this heat conductive sapphire material 102 be transmissive to the wavelength of interest when utilized within a ring laser 12 of the type depicted in FIG. 3 of the drawing. It is essential that both the laser beam 20 and pump beam 18 pass therethrough. In this manner it is possible to further introduce the cooling effect of frame 64 onto heat conductive material 102 and therefore onto crystal 11. What has been produced, in effect, is a crysta sandwich which provides for excellent heat removal capabilities. A pair of clamps or conductor restraints 106 and 108 fixedly secure sapphire material 102 to frame 104. The remaining components which make up the Dewar oooling chamber 100, as stated above, are the same as those which make up Dewar cooling chamber 10 and therefore need not be described in further detail.
It is possible with the transmissive Dewar cooling chamber 10 of this invention to maintain a semiconductor crystal 11 at a stable temperature of approximately 85° K. at approximately 20 m Torr. Cooling will take place in 5 minutes and the 100 ml capacity of the liquid-nitrogen reservoir 46 is sufficient to hold the temperature for approximately 4 hours without refilling. Accurate control of the temperature of the crystal 11 by means of the heating element allows for additional tuning of the ring laser to be achieved by changing the crystal temperature from approximately 85° K. to 140° K. with the resultant change in the wavelength of the output laser beams from 494 to 502 mm (0.14 mm/K). Although this invention has been described with reference to particular embodiments, it will be understood that this invention is also capable of further and other embodiments within the spirit and scope of the appended claims. | A transmission Dewar cooling chamber having a housing for supporting a semiconductor crystal therein within a temperature controlled environment. The housing has walls made partially of material transmissive to a preselected wavelength in order to allow the passing of a beam of electromagnetic radiation completely through the housing. In addition, mounting means are provided to move the housing in at least two dimensions. Securing the semiconductor crystal in place within the housing is a uniquely designed frame/mount arrangement which aids in establishing the temperature controlled environment for the crystal while also allowing the beam of electromagnetic radiation to pass completely through the crystal. | 5 |
BACKGROUND OF THE INVENTION
Microscopy systems in which a microscope is provided with an electronic camera having an electronic image-detecting device, such as a CCD array that is used to capture images of a sample for electronic display, have come to be increasingly used. For instance, Japanese Laid-Open Patent Application H8-190056 relates to this kind of system. Electronic image-detecting devices such as CCD arrays have a tendency to be less sensitive to light flux that is incident obliquely, and the larger the angle of incidence, the less sensitive they become. Therefore, a so-called “shading” phenomenon occurs, in which displayed images from such image-detecting devices tend to have dark peripheral areas and thus uneven brightness over the field of view.
BRIEF SUMMARY OF THE INVENTION
The present invention relates to: (1) a microscope middle barrel having an optical relay system, and relates, in particular, to a middle barrel for relaying enlarged images of a sample onto an electronic image-detecting device; (2) a microscope provided with such an optical relay system; and (3) a method of using these apparatus.
The object of the invention is to provide electronically displayed images without brightness artifacts causing uneven brightness over the field of view in the situation where an electronic image-detecting device, such as a CCD array, has been used to detect the images formed by a microscope.
A middle barrel for achieving the object of the invention includes a mount for connecting an electronic image-detecting device, a mount for connecting a microscope, an optical relay system for relaying images onto the electronic image-detecting device, and a control member having a transmissive region which transmits light and a shading region which blocks light, with the control member being used to make the detected images have a more uniform brightness over the field of view.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given below and the accompanying drawings, which are given by way of illustration only and thus are not limitative of the present invention, wherein:
FIG. 1 shows the construction of Embodiment 1 of a microscope according to the present invention;
FIG. 2 shows the optical paths of Embodiment 1, as well as the optical path of an alternative illumination optical system for viewing a sample in reflected light;
FIGS. 3A and 3B illustrate ray paths for explaining the principle of operation of the microscope according to the present invention;
FIG. 4 shows the microscope of the present invention as well as the positions of exit pupils for different objective lens systems which may be rotated into the light path, as well as the images of these exit pupils which form secondary pupils;
FIGS. 5A and 5B show optical paths through a middle barrel portion of a microscope in the case of using an objective lens system having an exit pupil at a (FIG. 5A) and one having an exit pupil at a′ (FIG. 5B) for preventing brightness artifacts from occurring in the field of view by providing a movable diaphragm in the middle barrel portion;
FIGS. 6A and 6B show optical paths through a middle barrel portion of a microscope in the case of using an objective lens system having an exit pupil at a (FIG. 6A) and one having an exit pupil at a′ (FIG. 6B) for preventing brightness artifacts from occurring in the field of view by providing a movable field lens in the middle barrel portion;
FIGS. 7A and 7B show optical paths through a middle barrel portion of a microscope in the case of using an objective lens system having an exit pupil at a (FIG. 7A) and one having an exit pupil at a′ (FIG. 7B) for preventing brightness artifacts from occurring in the field of view by providing plural diaphragms in the middle barrel portion;
FIG. 8 shows the construction of an embodiment of the invention which manually controls the aperture size of a diaphragm and its position along the optical axis; and
FIG. 9 shows the construction of an embodiment of the invention for automatically controlling the aperture size of a diaphragm and its position along the optical axis.
DETAILED DESCRIPTION
The microscope according to the present invention is characterized by the fact that it includes an optical imaging system for forming an intermediate image of a sample, an optical relay system for relaying the intermediate image onto an electronic image-detecting device, and a control member for controlling brightness artifacts in the detected electronic image. The present invention uses the control member for controlling the light flux that is incident onto the center region versus the periphery of an electronic image-detecting device so as to avoid a decrease in image brightness that otherwise occurs at the periphery of the detected image when using, for example, a CCD array to detect the image. More specifically, the control member is used to avoid a decrease in image brightness that normally occurs in electronically displayed images which have been captured with electronic image-detecting devices. Reduced brightness artifacts usually occur at the periphery of such images, and are caused both by the optical imaging system and by the electronic image-detecting device. When the microscope objective lens system is changed so as to provide a different magnification of an object being observed, the control member can be adjusted according to which objective lens system is in use so that the brightness level of the image field in both the central and peripheral regions is more uniform, while providing excellent resolution and contrast in the detected images.
The operation of a microscope which uses the present invention to improve the quality of detected electronic images that are then displayed to one or more viewers will now be described with reference to FIGS. 3A and 3B.
FIG. 3A shows light fluxes that are focused onto an image-detecting surface C by an optical relay system after preliminarily having been formed into an intermediate image. In FIG. 3A, the light flux indicated by A is axial and the light flux indicated by B is abaxial. The axial light flux A includes a main light ray (illustrated by the dashed line) which falls onto the image plane at normal incidence, and an accompanying cone of converging light rays, as is shown in the figure. Conversely, the abaxial light flux B includes a main light ray (chief ray) B 1 within a converging cone of light rays. The main light ray B 1 is incident onto the image plane at an oblique angle, as is shown in the figure. The abaxial (i.e., off-axis) light flux B is usually subject to vignetting so that the main light ray B 1 does not lie at the center of the converging cone of light rays, but instead lies closer to the inner border, as shown. In addition, the vignetting makes the numerical aperture of the abaxial light flux B smaller than that of the axial light flux A. When the abaxial light flux B is incident onto an image-detecting surface C of an electronic camera mounted in a microscope, it is not only incident onto the image-detecting surface C obliquely, but also has a smaller numerical aperture than the axial light flux A. Therefore, the detected images tend to suffer from unevenness in brightness artifacts, called shading, in which the area at the periphery of the image is darker in comparison to the area at the center of the image. These artifacts are undesirable in that they detract from the object under examination being accurately represented visually by the displayed image.
To avoid this, in the present invention, at least one diaphragm is advantageously placed along the optical axis within the optical relay system so as to simultaneously block the outer rays of the axial and abaxial light fluxes A and B. Thus, referring to FIG. 3B, of the light flux A, only the smaller cone angle of light rays A′ is transmitted to the image-detecting surface C; and, of the light flux B only the smaller cone angle of light rays B′ or B″ is transmitted to the image-detecting surface C. In this way, the axial and abaxial light fluxes are made to have nearly the same numerical aperture, thereby reducing the difference in brightness between the central and peripheral areas.
As is apparent from FIG. 3B, the abaxial light fluxes B′ and B″ have different angles of incidence onto the image-detecting surface C, with the rays of light flux B″ being closer to normal incidence onto the surface than the rays of light flux B′. Therefore, the light flux B″ is more advantageous, since the rays of this light flux are more nearly normal to the image-detecting surface, thereby making the detection of these rays less influenced by the falling sensitivity of electronic image-detecting devices to rays that are incident at oblique angles.
FIG. 1 shows the construction of an embodiment of the microscope according to the present invention, and FIG. 2 shows equivalent light paths for two ways to illuminate the object, one way of which is illustrated in FIG. 1 .
The construction of the microscope will now be described, with reference to FIG. 1. A microscope body 1 is provided with a stage 2 for mounting a sample O (such as a specimen) to be observed in transmitted light, and with a revolver 3 for interchangeably fixing an objective lens system 4 above the stage 2 . Below these components are provided a light source 5 and an optical illumination system that is formed of a collection lens 6 , a mirror 7 for folding the light path, and an auxiliary lens 8 for guiding light flux from the light source 5 to a condenser lens 9 that is fixed at the lower part of the stage. Above the microscope body 1 , an eyepiece unit 10 , a middle barrel 14 , and an imaging unit 16 are detachably mounted. The eyepiece unit 10 includes an imaging lens 11 that forms an intermediate image with light flux that, after being converged by the imaging lens 11 , is reflected by a beamsplitter prism 12 so as to form an image (not illustrated) that may be viewed by looking through the ocular 13 . Part of the light from the objective lens system 4 and imaging lens 11 is transmitted by the beamsplitter prism 12 and forms an image of the sample O at O′ along the optical axis within the middle barrel 14 . The objective lens system 4 images the sample O at infinity, and the imaging lens 11 images this light at position O′ along the optical axis within the middle barrel 14 . The middle barrel 14 includes a relay lens system 15 , formed of two positive lenses 15 1 and 15 2 , for relaying the image O′ onto the detecting surface of an electronic image-detecting device 17 (for instance, a CCD array) in the imaging unit 16 . The middle barrel 14 has a lower mount 18 and an upper mount 19 . The lower mount 18 (a dovetail) is used to detachably mount the middle barrel to the eyepiece unit 10 , which in turn is mounted to the microscope body 1 , and the upper mount 19 is used to detachably mount the imaging unit 16 to the middle barrel 14 . In this embodiment, the lower mount 18 is a round dovetail and the upper mount 19 is a C mount. These are connecting structures generally used in microscopes.
The construction described above is the same as that of a conventional microscope having a means to display images that are detected by an electronic image-detecting device. As shown in FIG. 2, the sample O may instead be observed in reflected light by having light from a light source 5 ′ illuminate the specimen via a collection lens 6 ′, auxiliary lens 8 ′, half-mirror 7 ′ and one of the objective lens systems 4 , 4 ′, in lieu of using the components 5 - 9 .
In this construction, where the objective lens system 4 has an exit pupil at a, as illustrated in FIG. 2, an image b of this exit pupil is formed at a point nearer the image-detecting device 17 than the sample image O′. In FIGS. 1 and 2, the relay lens system 15 is formed of the two positive lenses 15 1 and 15 2 . The image b of the exit pupil a of the objective lens system 4 is formed between these two positive lenses, by the combined action of imaging lens 11 and relay lens 15 1 , thereby forming a secondary pupil position at b. In FIG. 2, a light ray from the center of the sample O (i.e., an axial light ray) is shown by the solid line and a light ray from the periphery of the sample O (i.e., an abaxial light ray) is shown by the dotted line.
According to the present invention, a diaphragm 20 is positioned along the optical axis at or near the secondary pupil b. The diaphragm 20 simultaneously blocks the peripheral rays of both the axial and abaxial light fluxes, thereby providing reduced cone angles of rays that are transmitted with the same numerical aperture as illustrated in FIG. 3 B. Therefore, unevenness in brightness in the detected images is greatly reduced. Hereinafter, “unevenness in brightness in the detected images” will simply be referred to as “unevenness in brightness”. Diaphragm 20 is preferably located at the position b where the relay lens system 15 is telecentric to the rays from the sample O. In the figure, the diaphragm 20 is placed at the front focal plane of the positive lens 15 2 . In this way, the abaxial light flux takes the form of the light flux B″, illustrated in FIG. 3 B. Thus, light is incident onto the image-detecting device 17 at angles that are nearer normal incidence. Here, the unevenness of brightness does not necessarily occur symmetrically centered on the optical axis. Therefore, it is desirable that the diaphragm 20 can be placed off-center relative to the optical axis, i.e., be moveable in a plane perpendicular to the optical axis.
As shown in FIG. 4, different microscope objective lens systems 4 , positioned in the light path using the revolver 3 , have exit pupils at different positions, such as a, a′, a″, etc. within the range d 0 , depending upon their magnification and type. Accordingly, the secondary pupil positions can be at different positions b, b′, b″, etc., all within the range d shown in FIG. 4 . Therefore, it is preferable that diaphragm 20 is not fixed relative to the relay lens system 15 , but instead is movable within the range d or a slightly larger range. In this way, the position of the diaphragm can be adjusted to obtain the most even brightness over the field of view for each objective lens system 4 on the revolver 3 . For ease of illustration, only one such objective lens system 4 has been shown in FIG. 4 .
FIGS. 5A and 5B show the optical paths within the middle barrel 14 for the exit pupil being at a (FIG. 5A) and at a′ (FIG. 5 B). In these figures, axial light flux is shown by solid lines and abaxial light flux is shown by dotted lines. In this case, among the two positive lenses 15 1 , 15 2 of the relay lens system 15 , the positive lens 15 1 that is nearest the objective lens system 4 serves as a field lens. As described above, when the objective lens system 4 is replaced with, for instance, the objective lens system 4 ′, the exit pupil position moves along the optical axis from a in FIG. 5A to a′ in FIG. 5 B. In this instance, the image O′ of the sample O remains at a fixed position while the secondary pupil formed by the imaging lens 11 (FIG. 4) and the field lens 15 1 is moved from b in FIG. 5A to b′ in FIG. 5 B. According to this, diaphragm 20 is moved from the position 1 (circled, in FIG. 5A) to the position 2 (circled, in FIG. 5 B). This allows the simultaneous blocking of peripheral portions of the axial and abaxial light fluxes so that each has nearly the same numerical aperture. Consequently, images having reduced shading, and thus more even brightness, can be obtained for each objective lens system 4 , 4 ′.
As shown in FIG. 5B, when the secondary pupil b′ is relayed onto the electronic image-detecting device 17 , the angles of incidence of the abaxial light flux, shown by dotted lines, increase. In such a case, instead of coinciding with that of the secondary pupil b′, the position of the diaphragm 20 can be slightly shifted along the optical axis nearer the sample so that the angles of incidence onto the electronic image-detecting device 17 of the abaxial light flux do not increase.
The following construction allows the diaphragm 20 to have an aperture diameter and a position along the optical axis that is adjustable relative to the middle barrel 14 . A diaphragm having a variable aperture is used for the diaphragm 20 , and is held within the middle barrel 14 as follows. In addition to the barrel body, a cylindrical inner barrel is inserted in the barrel body. The outer diameter of the inner barrel and the inner diameter of the barrel body are made nearly equal, and the variable aperture diaphragm is mounted within the inner barrel. This construction allows the variable aperture diaphragm to be shifted along the optical axis by moving the inner barrel longitudinally relative to the middle barrel 14 .
The moving range of the diaphragm 20 along the optical axis is determined as follows. Referring to FIG. 4, among the objective lens systems 4 , 4 ′, etc., which may be mounted on the revolver 3 , the objective lens system having its exit pupil nearest the sample O, and the objective lens system having its exit pupil farthest from the sample O, are selected. These exit pupils are illustrated in FIG. 4 as a″ and a′, respectively. The conjugate points in the relay lens system 15 to these two exit pupils are then determined (i.e., conjugate points b″ and b′). The distance between these two conjugate points is the minimum moving range of the diaphragm 20 . As described above, the diaphragm 20 does not necessarily coincide with the secondary pupils b, b′ (illustrated in FIGS. 5 A and 5 B), etc. Assuming that the optical system between the exit pupils a, a′, etc. and the secondary pupils b, b′, etc. (namely, the optical system consisting of the imaging lens 11 and the field lens 15 1 in FIG. 4 ), has a lateral magnification of M, it is preferable that the moving range of the diaphragm 20 along the optical axis satisfies the following Condition (1):
d′< 1.1 M 2 d Condition (1)
where
d′ is the moving range of the diaphragm along the optical axis,
M is the lateral magnification of the optical system between the exit pupils a, a′ and a″ and the secondary pupils b, b′, and b″ (i.e., the optical system here consists of the imaging lens 111 and the field lens 15 1 in FIG. 4 ), and
d is the minimum moving range of the diaphragm 20 (i.e., the distance between b″ and
b′, as illustrated in FIG. 4 ).
It is more preferable that the moving range of the diaphragm 20 along the optical axis satisfies the following Condition (1′):
d′<M 2 d Condition (1)
where
d′, M and d are as defined above.
Although the diaphragm 20 can have a fixed aperture diameter, a variable aperture diameter enables better reduction of unevenness of brightness artifacts, and is also desirable in order to optimize the resolution and contrast. For the maximum diameter of the adjustable aperture of the diaphragm 20 , it is preferable that the following Condition (2) is satisfied:
D< 1.2 M D 1 Condition (2)
where
D is the maximum diameter of the adjustable aperture of the diaphragm 20 ,
M is as defined above, and
D 1 is the largest exit pupil diameter among the exit pupils of the objective lens systems 4 , 4 ′, 4 ″, etc.
This relationship allows the passage of the maximum light flux from the sample without needlessly partially blocking light from any of the objective lens systems 4 , 4 ′, 4 ″, etc., thus preventing needless loss of light flux and the resulting lowering of brightness of the image. Instead of Condition (2), the following Condition (3) can be used, providing high precision in making and positioning of the components is maintained:
D<M D 1 Condition (3)
where
D, M and D 1 are as defined above.
The relationship between the numerical aperture NA of the light flux entering the electronic image-detecting device 17 (from the relay lens system 15 ) and the pixel diameter P (in nm) of the electronic image-detecting device 17 will now be considered in terms of resolution.
As is well-known, the diameter of the central spot of the Airy Disc that is formed by diffraction effects of the light flux incident onto the electronic image-detecting device 17 (assuming a circular stop) is given by Equation (1):
Φ=1.22 λ/ NA Equation (1)
where
Φ is the diameter of the Airy Disc,
λ is the wavelength (here assumed to be 550 nm), and
NA is the numerical aperture of the incident light flux.
If more than eight adjacent pixel elements of the electronic image-detecting device 17 are illuminated by the Airy Disc, the point spread function will be sampled at a higher spatial frequency than needed for its accurate determination. In other words, the detecting system will have a higher resolution than needed. Thus,
1.22 λ/ NA≦ 8 P Inequality (1A)
where
P is the distance between the centers of adjacent pixel elements, and
λ, and NA are as defined above.
The above inequality can be written:
0.61/(2 P )≦2 NA/λ Inequality (1B)
where λ, NA and P are as defined above.
In other words, when 0.61/(2P) becomes larger than 2NA/λ, the electronic image-detecting device 17 will have a higher resolution than needed to measure the resolution of the optical system.
On the other hand, if fewer than two adjacent pixel elements of the electronic image-detecting device 17 are illuminated by the Airy Disc, the point spread function will not be sampled at a sufficient spatial frequency for its accurate determination. Thus,
1.22 λ/ NA≧ 2 P Inequality (2A)
where λ, NA and P are as defined above.
Inequality (2A) can be written:
2 NA/λ≦ 2.44/(2 P ) Inequality (2B)
where λ, NA and P are as defined above.
In other words, when 2NA/λ becomes larger than 2.44/(2P), the electronic image-detecting device 17 will have too low a resolution to accurately measure the resolution of the optical system. In conclusion, combining Inequality (1B) and (2B), it is desirable that the following Condition (4A) is satisfied:
0.61/(2 P )≦2 NA/λ≦ 2.44/(2 P ) Condition (4A)
where
P, NA and λ are as defined above.
If the illumination incident the detecting surface is not limited by a circular stop or diaphragm, but is instead limited by an aperture with sides having straight lines, such as a rectangular stop or diaphragm, Condition (4A) does not apply. For example, if the diaphragm (i.e., stop) is rectangular, the diffraction pattern will be approximately the Fraunhofer diffraction pattern of a rectangular aperture, as is well known. (See, for example, pages 62-63 of Introduction to Fourier Optics , by Joseph W. Goodman, McGraw-Hill, 1968.) For such a rectangular stop or diaphragm, the following Condition (4B) applies:
0.50/(2 P )≦2 NA/λ≦ 2.00/(2 P ) Condition (4B)
where
P, NA and λ are as defined above.
From the above, it is preferable that the following Condition (4C) is satisfied in using diaphragms of various shapes:
0.50/(2 P )≦2 NA/λ≦ 2.44/(2 P ) Condition (4C)
where
P, NA and λ are as defined above.
Returning to the previous discussion, in FIGS. 5A and 5B, the exit pupil moves from the position a in FIG. 5A to the position a′ in FIG. 5B, depending on the objective lens system that is revolved into the light path of the microscope. At the same time, the secondary pupil that is formed by the imaging lens 11 (see FIG. 4) and field lens 15 1 moves from the position b in FIG. 5A to the position b′ in FIG. 5 B. Thus the diaphragm 20 may be moved so as to maintain its position at or very near the axial position of the secondary pupil. Due to this axial movement of the diaphragm, the aperture diameter of the diaphragm 20 will need to be adjusted in order to balance the quantities of light in the axial and abaxial light fluxes so as to reduce the unevenness of brightness.
FIGS. 6A and 6B show optical paths through a middle barrel portion of a microscope in the case of using an objective lens system having an exit pupil at a (in FIG. 6A) and one having an exit pupil at a′ (in FIG. 6B) for preventing brightness artifacts from occurring in the field of view by providing a movable field lens in the middle barrel portion. In these figures, axial light fluxes are shown by the solid lines and abaxial light fluxes are shown by the dotted lines. In this embodiment of the invention, among the two positive lenses 15 1 , 15 2 of the relay lens system 15 , the positive lens 15 1 that is nearest the objective lens system 4 serves as a field lens. When the objective lens system 4 is replaced with, for instance, the objective lens system 4 ′, the exit pupil position is moved along the optical axis from a in FIG. 6A to a′ in FIG. 6 B. Here, the image O′ of the sample O, that is formed by the objective lens systems 4 , 4 ′ and the imaging lens 11 , is fixed (i.e., not moved by the exchange of the objective lens system 4 ). Therefore, the image of O′ that is formed by the field lens 15 1 remains substantially stationary, whereas the secondary pupil b′ (the image of the exit pupil a′) moves along the optical axis. Therefore, the field lens 15 1 can be moved to form the secondary pupils b, b′, and b″ near the fixed diaphragm 20 . This allows for the simultaneous blocking of the peripheral rays of both the axial and abaxial light fluxes by the diaphragm 20 so that images with less brightness unevenness over the field of view can be obtained for each objective lens system 4 , 4 ′, and 4 ″.
FIGS. 7A and 7B show optical paths through the middle barrel in the case where the diaphragm 20 is not moved axially when the secondary pupils b, are adjusted. Instead, multiple diaphragms 20 1 , 20 2 , etc. are positioned at locations that nearly coincide in position with the secondary pupils b, b′, etc. Here, an appropriate diaphragm 20 1 , 20 2 , etc. is selected for the objective lens systems 4 , 4 ′, etc. for simultaneously blocking the outer rays of the axial and abaxial light fluxes. When the objective lens system 4 is used and the exit pupil is at the position a, as shown in FIG. 7A, the diaphragm 20 1 is positioned at the secondary pupil b with its adjustable aperture used to block the peripheral rays. The other diaphragm 20 2 is maintained with its aperture open so as to not block any of the light flux. When the objective lens system 4 ′ is placed in the light path and the exit pupil is at a′, as in FIG. 7B, the diaphragm 20 2 , positioned at the secondary pupil b′, is used with its adjusted aperture blocking peripheral rays and with the diaphragm 20 1 being maintained with its aperture open so as to not block any of the light flux.
Although FIGS. 7A and 7B illustrate only two diaphragms 20 1 and 20 2 , more than two diaphragms can be used, if necessary. The diaphragm 20 , used in the embodiments above, can be a diaphragm having a continuously adjustable aperture such as an iris diaphragm. Alternatively, a diaphragm having an electrically adjustable transparent region, such as a liquid crystal device, can be used. In embodiments where the diaphragm 20 is at a fixed position, the diaphragm 20 may, instead of having an adjustable transparent region described above, consist of plural aperture plates having different aperture diameters that are used in turn, or it may have an aperture plate with apertures of different diameters, wherein the plate can be adjusted in position crosswise to the optical path so that the diameter of an aperture inserted in the optical path is changed. The control of the apertures and the position of the diaphragm 20 along the optical axis will now be explained.
FIG. 8 shows the construction of a manually controlled diaphragm. The diaphragm 20 is provided with an aperture diameter and position control mechanism 22 for controlling the diameter of an aperture and the position of an aperture along the optical axis. The aperture diameter can be adjusted by, for instance, a control mechanism 22 that independently controls the aperture diameter of the diaphragm and the position of the diaphragm along the optical axis. Such control mechanisms are well-known in the art. A connection is made so as to input image signals of the sample O to a monitor 21 in order to view enlarged images that are obtained from the electronic image-detecting device 17 . In this configuration, by observing enlarged images of the sample O that are displayed on the monitor 21 , a viewer can operate the aperture diameter and position control mechanism 22 in order to adjust the aperture diameter as well as the position of the diaphragm 20 along the optical axis so as to obtain images with the least unevenness of brightness and so as to have excellent resolution. Here, if a surface with constant reflectivity (such as a mirror) is used as the sample O when adjusting the unevenness of brightness, the adjustment can be performed more easily.
FIG. 9 shows the construction of an embodiment in which the aperture diameter and the position along the optical axis of the diaphragm 20 are automatically adjusted. Diaphragm 20 is provided with an aperture diameter and position control mechanism 23 for controlling its aperture and position along the optical axis based on a signal provided from an external source. Signals for enlarged images of the sample O obtained from the electronic image-detecting device 17 are input into a processing unit 24 . The processing unit 24 calculates the relative difference in light quantity between the central and peripheral areas based on the image signals obtained from the electronic image-detecting device 17 , and sends a signal to the control mechanism 23 indicating the position of the diaphragm 20 for canceling the difference. Meanwhile, the processing unit 24 calculates the brightness of the image and sends a signal to the control mechanism 23 indicating the proper aperture diameter for the diaphragm 20 . The control mechanism 23 adjusts the aperture diameter and position of the diaphragm 20 based on the signals indicating the aperture diameter and position of the diaphragm sent from the processing unit 24 .
The invention being thus described, it will be obvious that the same may be varied in many ways. For example, a combination of positional adjusting of the diaphragm 20 and of the field lens 15 1 along the optical axis can be used. Also, the number of objective lens systems that may be included on the revolver is not limited to those listed in the previous embodiments. Such variations are not to be regarded as a departure from the spirit and scope of the invention. Rather the scope of the invention shall be defined as set forth in the following claims and their legal equivalents. All such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. | Microscope apparatus and a method are disclosed for avoiding a reduction in intensity at the periphery of a microscope image that is detected by an electronic image-detector and then displayed. The method includes inserting one or more stops along the optical axis of the microscope, said stop(s) having a central transmissive region and a blocking region outside the central transmissive region; and positioning at least one stop so as to simultaneously block peripheral portions of axial and abaxial light fluxes from a sample under observation from being incident onto the electronic image detector, thereby making the axial and abaxial light fluxes that are incident onto the electronic image detector substantially equal in detected brightness. The apparatus disclosed is for implementing the method, and includes a relay optical system, a middle barrel of a microscope, and one or more stops as described above which simultaneously block peripheral portions of axial and abaxial light fluxes from a sample under observation from being passed by the middle barrel. | 6 |
TECHNICAL FIELD
[0001] The present invention relates to a ply adhesive for ply bonding plural sheets of base paper to make an integrally laminated sanitary tissue paper, and to a sanitary tissue paper produced by ply bonding plural sheets of base paper with a ply adhesive.
BACKGROUND ART
[0002] As is known, certain types of sanitary tissue paper products such as toilet paper, tissue paper, and kitchen paper are made by integrally laminating plural sheets of base paper. In such sanitary tissue papers, a layer of base paper is often referred to as ply. For example, a sanitary tissue paper is called “two-ply” when it is a laminate of two sheets of base paper, and “three-ply” when three sheets of base paper are laminated. Aside from embossing, an adhesive is used for the integration and lamination of base paper (ply) in these multi-ply sanitary tissue papers.
[0003] A sanitary tissue paper produced by integrally laminating sheets of base paper with an adhesive is more advantageous than an embossed tissue paper laminate in that the base paper is less likely to delaminate. A drawback, however, is that portions of the paper with an applied adhesive harden, and make the paper texture poor.
[0004] Toilet paper as a variety of sanitary tissue paper is commercially available in the form of a toilet paper roll produced by winding a band of paper around a paper cylinder. A pick-up paste used to bond toilet paper to the paper cylinder, and a tail sealing paste use to seal the tip of the roll in making a toilet paper roll take measures to make peeling of sanitary tissue paper easier, for example, by using an adhesive agent that contains a softening agent to prevent hardening of the adhesive applied portions, or unintended ripping of paper when peeling the tail, or to allow the toilet paper to smoothly separate itself from the paper cylinder. The pick-up paste and the tail sealing paste use carboxymethyl cellulose as the adhesive agent, and the softening agent is an oil such as silicon oil, an alginate such as sodium alginate, or a polyether such as polyethylene oxide.
[0005] One may think of using the pick-up paste or tail sealing paste as a ply adhesive to reduce hardening of the paper. However, it is problematic to use traditional pastes such as the pick-up paste as a ply adhesive. Specifically, the ply adhesive, unlike the pick-up paste, is not intended for peeling, and is applied over a certain range of base paper, instead of being locally applied at the either end of a roll. It is accordingly difficult, for example, with an oil-based paste to provide sufficient ply bond strength because such pastes coat the constituent fibers of the base paper, and inhibit hydrogen bonding. A paste mixed with, for example, an alginate cannot be easily applied over a wide range in a uniform fashion because the alginate undergoes gelation. Polyethers such as polyethylene oxide are often used for pick-up pastes. However, because pick-up pastes are intended to bond the paper to a hard paper cylinder, the paste is too sticky to be used as a ply adhesive, and tends to have high viscosity, which makes it difficult to uniformly apply the paste.
CITATION LIST
Patent Literature
[0006] PTL 1: JP-A-2011-206369
[0007] PTL 2: Japanese Patent No. 4619673
[0008] PTL 3: Japanese Patent No. 4619671
[0009] PTL 4: JP-A-2012-213508
[0010] PTL 5: Japanese Patent No. 4420872
[0011] PTL 6: JP-A-9-40926
SUMMARY OF INVENTION
Technical Problem
[0012] A primary object of the present invention, then, is to provide a ply adhesive of desirable applicability that can be sufficiently used for ply bonding without deteriorating the texture of sanitary tissue paper. The present invention is also intended to provide a sanitary tissue paper having a desirable texture that does not involve ply delamination of base paper layers.
Solution to Problem
[0013] The present invention provided a solution to the foregoing problems, as recited below along with the effects of the invention.
Invention According to Claim 1
[0014] A ply adhesive comprising:
[0015] 1 to 5 mass % of carboxymethyl cellulose as an adhesive agent, the carboxymethyl cellulose having a viscosity in a 1 mass % aqueous solution of 100 mPa·s or less; and
[0016] 1 to 5 mass % of at least one softening agent selected from propylene glycol, glycerine, and butylene glycol.
Invention According to Claim 2
[0017] A multi-ply sanitary tissue paper as an integrated laminate of plural sheets of base paper that are bonded to each other with an adhesive,
[0018] wherein the adhesive contains:
1 to 5 mass % of carboxymethyl cellulose as an adhesive agent, the carboxymethyl cellulose having a viscosity in a 1 mass % aqueous solution of 100 mPa·s or less; and 1 to 5 mass % of at least one softening agent selected from propylene glycol, glycerine, and butylene glycol, and
[0020] wherein the softening agent is applied in an amount of 1 to 20 mg/m 2 .
Advantageous Effects of Invention
[0021] The present invention provides a ply adhesive of desirable applicability that can be sufficiently used for ply bonding without deteriorating the texture of sanitary tissue paper. A sanitary tissue paper having a desirable texture that does not involve ply delamination of base paper layers is also provided.
BRIEF DESCRIPTION OF DRAWINGS
[0022] FIG. 1 is a cross sectional view of a sanitary tissue paper according to an embodiment of the present invention.
[0023] FIG. 2 is a diagram explaining an adhesion measurement method.
DESCRIPTION OF EMBODIMENTS
[0024] An embodiment of the present invention is described below with reference to FIG. 1 .
[0025] As illustrated in FIG. 1 , a ply adhesive 20 according to the present embodiment is used to bond sheets of base paper 10 that are laminated to make a sanitary tissue paper 1 , which is, for example, toilet paper, kitchen paper, or tissue paper. The ply adhesive 20 is particularly suited for toilet paper among these sanitary tissue papers, and suitably provides the softness needed for toilet paper in wiping fecal material off the skin, and the ply delamination strength needed in such applications. Specifically, the ply adhesive 20 is suited for a water-disintegrable sanitary tissue paper having a basis weight of 12 to 22 g/m 2 per ply as measured according to JIS P 8124 2011, and a ply thickness of 80 to 140 μm as measured according to JIS P 8118 1998.
[0026] A characteristic feature of the ply adhesive according to the present embodiment is that it contains carboxymethyl cellulose having a viscosity in a 1 mass % aqueous solution of 100 mPa·s as an adhesive agent, and at least one softening agent selected from propylene glycol, glycerine, and butylene glycol.
[0027] Carboxymethyl cellulose has good affinity to pulp fibers configured from the constituent cellulose of the base paper, and has the effect to bond the sheets of base paper to each other. Carboxymethyl cellulose is also used as a thickener, and is available in various different viscosities. The present embodiment uses a carboxymethyl cellulose having a viscosity in a 1 mass % aqueous solution of 100 mPa·s as measured according to JIS Z 8803 2011. In this way, desirable applicability to paper surface can be provided while ensuring bondability. The carboxymethyl cellulose with such a viscosity also can sufficiently exhibit its effect without inhibiting the effect of the mixed softening agent.
[0028] Propylene glycol, glycerine, and butylene glycol have good affinity to pulp fibers as does carboxymethyl cellulose, and are miscible with the carboxymethyl cellulose dissolved in a common solvent such as water and ethanol. Propylene glycol, glycerine, and butylene glycol also make the pulp fiber flexible, and have hygroscopicity that adds moisture to the base paper. These materials also do not undergo gelation to deteriorate applicability, nor do they coat the pulp fibers to inhibit the function of the adhesive agent carboxymethyl cellulose.
[0029] Specifically, the ply adhesive according to the present embodiment contains the adhesive agent in a proportion of 1 to 5 mass %, and the softening agent in a proportion of 1 to 5 mass %. Bondability, and the effect of the softening agent become insufficient when the proportions of the adhesive agent and the softening agent are less than 1 mass %, whereas applicability deteriorates when these are contained in amounts of more than 5 mass %. The selected softening agent moisturizes the bonded portions with its moisture absorbing effect. However, the moisture absorption does not cause an excess loss of adhesion when the adhesive agent used is carboxymethyl cellulose having a viscosity in a 1 mass % aqueous solution of 100 mPa·s or less, and is contained in the foregoing proportion.
[0030] As described above, the ply adhesive according to the present embodiment effectively develops the bondability provided by the carboxymethyl cellulose, and the softening and moisturizing effect of the softening agent. Accordingly, portions with the applied ply adhesive do not become hard, and the overall texture of the sanitary tissue paper does not deteriorate.
[0031] Another effect of the ply adhesive of the present embodiment is that the ply adhesive can be sprayed onto the base paper, in addition to providing bondability, flexibility, and moisture retention. Specifically, instead of being sprayed, traditional ply adhesives are applied by using a method that applies a ply adhesive to an embossed portion created in base paper, or a method that prints a ply adhesive pattern using a roll printing apparatus. This is because a traditional ply adhesive had the difficulty in achieving a viscosity range that allows spraying while at the same time satisfying both bondability and flexibility. The ply adhesive according to the present embodiment, with the adhesive agent and the softening agent contained in the specific proportions, does not clog a nozzle even when applied by being sprayed in low viscosity. Unlike application involving embossing or a roll printing apparatus, spray application does not involve pressing of paper surface with a roll or the like, and the sanitary tissue paper can have an improved texture. The appropriate range of the final viscosity of the adhesive according to the present embodiment is 20 mPa·s to 100 mPa·s as measured according to JIS Z 8803 2011. This viscosity range is suited for the spray application of the paste described above. Viscosity can be measured using a viscometer DV-E available from Brook Field. Specifically, the ply adhesive is charged into a beaker placed on a horizontal table, and the viscosity is measured with the spindle of the viscometer fully immersed in the ply adhesive. The measurement is made in a 25° C. environment after bringing the subject of measurement to equilibrium at 25° C.
[0032] For the production of the ply adhesive according to the present embodiment, carboxymethyl cellulose is first dissolved in a suitable solvent, and propylene glycol, glycerine, and/or butylene glycol are mixed into the carboxymethyl cellulose solution. The solvent may be any appropriate common solvent. Typical examples include water, and lower alcohols such as ethanol.
[0033] The ply adhesive according to the present embodiment may contain known additives, such as a pH adjuster, a viscosity adjuster, and a preservative, as appropriate.
[0034] A sanitary tissue paper according to the present embodiment using the ply adhesive is described below. The sanitary tissue paper according to the present embodiment is bonded with the ply adhesive that is applied in such an amount that the softening agent contained therein is 1 to 20 mg/m 2 of bonded surface. As shown in FIG. 1 , the bonded surface X represents the mated surfaces of the base paper 10 . For example, in a two-ply sanitary tissue paper, the opposing two sheets of base paper represent a single bonded surface. In a three-ply sanitary tissue paper as a laminate of three sheets of base paper, a total of two bonded surfaces are formed by the two sheets of base paper constituting the surfaces, and the base paper sandwiched in between.
[0035] The number of laminated base paper layers (the number of ply) in the sanitary tissue paper according to the present embodiment is not limited, and is typically about 2 to 4. Sufficient effects can be obtained when 2 to 4 base paper layers are present.
[0036] In the sanitary tissue paper according to the present embodiment, the basis weight of the base paper, and the total thickness of the sanitary tissue paper are not necessarily limited. Desirably, the basis weight is 12 to 22 g/m 2 per ply, and the total thickness of the sanitary tissue paper is 140 to 400 μm. In this case, the ply adhesive according to the present embodiment can prominently exhibit its effects. The basis weight is the measured value by the basis weight measurement method of JIS P 8124 1998. The paper thickness is measured with a dial thickness gauge (thickness meter) Peacock G (OZAKI MFG Co., Ltd.) under the conditions of JIS P 8111 1998 after the test piece is sufficiently humidified under the same conditions. Specifically, a plunger is lowered to a measurement table after checking for any dirt, dust, or other foreign particles between the plunger and the measurement table, and the dial thickness gauge is set to zero by moving the scale. After lifting the plunger, a sample is placed on the test stage, and the plunger is slowly lowered, and the reading on the gauge is recorded. Here, the plunger simply sits on the sample. The plunger has a metallic terminal with a circular flat surface measuring 10 mm in diameter, and perpendicularly contacts the plane of the paper. The paper thickness is measured under a load of about 70 gf. The paper thickness is the thickness of one-ply paper in the case of one-ply, and the thickness of multi-ply paper in the case of multi-ply. The paper thickness is the mean value of ten measurements.
[0037] Application of the ply adhesive in the sanitary tissue paper according to the present embodiment is not particularly limited, and the ply adhesive may be applied by being applied to embossed portions created in the base paper, or by being printed in a pattern using a roll printing apparatus. Preferably, the ply adhesive is applied by being sprayed. As described above, the ply adhesive according to the present embodiment can be applied by being sprayed, and spray application of the ply adhesive prevents compaction of the base paper, and lowering of paper softness. Particularly, spray application can improve softness by preventing hardening of portions bonded with the ply adhesive according to the present embodiment.
[0038] In the sanitary tissue paper according to the present embodiment, the area percentage of the ply adhesive may be appropriately adjusted, and the ply adhesive may be applied throughout the paper. The shape of an embossed pattern, and the shape and the size of bonded portions formed by pattern printing of the ply adhesive are subject to design change, as appropriate.
[0039] In applying the ply adhesive to the base paper, the ply adhesive may be applied to either surface of a pair of sheets constituting the bonded surface. The ply adhesive may be applied to only one of the surfaces, or to the both surfaces, provided that the ply adhesive is applied in the foregoing amount in terms of a combined amount on these surfaces.
[0040] In the sanitary tissue paper according to the present embodiment, the ply adhesive can provide sufficient adhesion (ply delamination strength), and the softening agent contained in the ply adhesive provides moisture to the paper with its moisturizing effect, in addition to preventing hardening of the bonded portions. This makes it possible to provide a multi-ply sanitary tissue paper having a desirable texture, despite that the ply adhesive is used.
EXAMPLES
[0041] Examples and Comparative Examples of the adhesive according to the present invention were tested and evaluated for bondability, operability, and the paper quality of sanitary tissue paper after application, and the effects were examined.
Bondability
[0042] A 1.5 mass % aqueous solution of carboxymethyl cellulose was prepared with a carboxymethyl cellulose having a viscosity in a 1 mass % aqueous solution of 60 mPa·s. The chemicals shown under the heading “Softening agent” in Table 1 below were mixed into the 1.5 mass % carboxymethyl cellulose aqueous solution in the concentrations shown under the heading “Applied amount of softening agent” to obtain a ply adhesive of Examples and Comparative Examples.
[0043] The ply adhesive was used to bond two sheets of base paper, and make a two-ply sanitary tissue paper. Crape paper having a basis weight of 14.5 g/m 2 was used as the base paper, and the ply adhesive was sprayed over one surface of one of the base sheets in such an amount that the softening agent contained in the ply adhesive had the amount shown in Table 1. The two sheets were laminated immediately after spraying the ply adhesive, and left unattended for 1 day in a 25° C., 50% rh environment to prepare a measurement sample.
[0044] As a test of bondability, a sample cut into a size measuring 20 mm in width (CD direction) and 100 mm in length (MD direction) was peeled from one end of the length over a distance of 30 mm, and 25 mm of each separated end was fixed to a chuck of a tensile tester, as shown in the front view (1) and the side view (2) in FIG. 2 . One of the chucks was then pulled over a distance of 50 mm at a rate of 100 mm/min, and the ply delamination strength was measured. The sample was then evaluated using the measured value. The evaluation result was “Good” when the strength was 5 cN or more and less than 20 cN, and “Acceptable” when the strength had an excessively high value of 20 cN or more. Results with a strength of less than 5 cN were “poor”.
[0045] The abbreviations PG, BG, and PEO under the heading “Softening agent” in Table 1 represent propylene glycol, butylene glycol, and polyethylene oxide, respectively.
Operability
[0046] The ply adhesive of each example was sprayed onto base paper, and the paper was visually inspected to see whether the ply adhesive was uniformly applied to the paper surface. Samples were determined as “Good” when the ply adhesive was uniformly applied, and considered to be usable for spray application, and “Poor” when the paper had nonuniformly applied portions due to, for example, dripping, and was considered to cause problems in the operation of a spray applicator.
[0000]
TABLE 1
Examples
Ex. 1
Ex. 2
Ex. 3
Ex. 5
Ex. 6
Ex. 8
Ex. 9
Softening agent
PG
PG
PG
Glycerine
Glycerine
BG
BG
Applied amount of
1
5
10
1
10
1
10
softening agent (mg/m 2 )
Bond strength
Good
Good
Good
Good
Good
Good
Good
Operability
Good
Good
Good
Good
Good
Good
Good
Comparative Examples
Com. Ex. 1
Com. Ex. 2
Com. Ex. 3
Com. Ex. 4
Com. Ex. 5
Com. Ex. 6
Softening agent
PG
Glycerine
BG
Silicon
Sodium
POE
oil
alginate
Applied amount of
30
30
30
1
1
1
softening agent (mg/m 2 )
Bond strength
Poor
Poor
Poor
Poor
Good
Acceptable
Operability
Good
Good
Good
Good
Poor
Poor
[0047] As shown in Table 1, the results were desirable for both bondability and operability in the Examples of the present invention. On the other hand, the results were not sufficient in at least one of bondability and operability in Comparative Examples.
Confirmation of Paper Quality
[0048] Propylene glycol was mixed into a 1.5 mass % aqueous solution of carboxymethyl cellulose having a viscosity in a 1 mass % aqueous solution of 60 mPa·s in the amounts shown in Table 2 below. The adhesive was sprayed over a surface of base paper having a basis weight of 14.5 g/m 2 in such an amount that the amount of softening agent per bonded surface was as shown in Table 2. A two-ply sanitary tissue paper was obtained using the same procedure used to make samples for the bondability test. The sanitary tissue paper was used as a sample in a sensory test, in which 64 testers were asked to judge softness and moisture by touching the sample with hand. The test was conducted to measure each sample as being “soft to hard” and “moist to dry” in a bipolar scale of 1 to 7, and the mean value was calculated for evaluation. Each sample was given a score of 1 to 7 from soft and moist to hard and dry. Lower scores mean better evaluation results for each criterion.
[0000]
TABLE 2
Comparative
Example
Example
Applied amount of softening agent (mg/m 2 )
2.2
0.0
Softness
2.7
2.9
Moisture
3.1
3.6
[0049] As shown in Table 2, softness was more desirable in the Example of the present invention than in Comparative Example. The Example of the present invention was particularly desirable in terms of moisture.
[0050] From the results of these tests, it can be said that the ply adhesive of the present invention, and the sanitary tissue paper using the ply adhesive develop sufficient adhesion (ply delamination strength), and provide a desirable texture that does not involve hardening of the bonded portions.
REFERENCE SIGNS LIST
[0000]
1 Sanitary tissue paper
10 Base paper (ply)
20 Ply adhesive
X Bonded surface | To provide a ply adhesive that is capable of expressing a sufficient ply adhesion strength, does not harden an area where the ply adhesive is applied, and does not worsen paper texture. The problem can be solved by a ply adhesive that includes: 1-5 mass % of carboxymethylcellulose, a 1 mass % aqueous solution of the carboxymethylcellulose having a viscosity of 100 mPa·s or lower, as an adhesive; and 1-5 mass % of at least one member selected from among propylene glycol, glycerol and butylene glycol as a softening agent. | 3 |
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